Method and system for drilling with a limited laser drill.

专利摘要:
A method of drilling a hole (52) in a component (38) is provided. The method has a laser beam which is limited by means of a light guiding and focusing mechanism of a laser drill. The confined laser beam (64) of the confined laser drill (62) is directed towards a nearby wall (66) of the component (38) and a first property of light is detected from the hole (52) in the nearby wall (66) of the component (38) with a first sensor (110) which is positioned outside the component (38). The method further includes sensing a second characteristic of light from the hole (52) in the nearby wall of the component (38) with a second sensor (112). The second property of light is different from the first property of light. The method also includes determining a hole advance on the basis of the detected first light property and the detected second light property.
公开号:CH710618B1
申请号:CH00016/16
申请日:2016-01-06
公开日:2021-01-15
发明作者:Hu Zhaoli；Denis Darling Abe；Elijah Mcdowell Shamgar；Anthony Serieno Douglas
申请人:Gen Electric；
IPC主号:

专利说明:

FIELD OF THE INVENTION
The present invention relates to a method according to claim 1 and a system according to claim 9 for drilling one or more holes in a component using a limited laser drill.
BACKGROUND TO THE INVENTION
Turbines are widely used in industrial and commercial operations. A typical commercial steam or gas turbine used to generate electrical power contains alternating stages of stationary and rotating blades. For example, stationary vanes can be attached to a stationary component such as a casing surrounding a turbine, and rotating blades can be attached to a rotor located along an axial centerline of the turbine. A compressed working fluid, such as, but not limited to, steam, combustion gases, or air, flows through the turbine, and the guide vanes accelerate and direct the compressed working fluid onto the subsequent stage of rotating blades to cause the rotating blades to move, thereby causing the The rotor rotates and work is done.
An efficiency of the turbine generally increases with increasing temperatures of the compressed working fluid. However, excessive temperatures within the turbine can reduce the longevity of the airfoils in the turbine and thus increase repairs, maintenance, and failures associated with the turbine. As a result, various designs and methods have been developed to achieve cooling on the airfoils. For example, a cooling medium can be supplied to a cavity inside the airfoil to remove heat from the airfoil in a convective and / or conductive manner. In certain embodiments, the cooling medium can flow out of the cavity through cooling channels in the airfoil to achieve film cooling over the outer surface of the airfoil.
As temperatures and / or performance standards continue to rise, materials used for the airfoil become increasingly thin, making reliable manufacture of the airfoil increasingly difficult. For example, the airfoil can be cast from a high alloy metal and a thermal barrier coating can be applied to the outer surface of the airfoil to increase thermal insulation. A jet of water can be used to create cooling channels through the thermal barrier coating and the outer surface, but the water jet can cause portions of the thermal barrier coating to peel off. Alternatively, the thermal barrier coating can be applied to the outer surface of the airfoil after the cooling channels have been created by an electrical discharge machine (EDM), but this requires additional processing to remove any thermal barrier coating covering the newly created cooling channels. In addition, this process of reopening the cooling holes after the coating process becomes increasingly difficult and requires more man-hours and skills as the sizes of the cooling holes decrease and the number of the cooling holes increase.
A laser drill that uses a focused laser beam can also be used to create the cooling passages through the airfoil with reduced risk of peeling of the thermal barrier coating. However, the laser drill may require precise control due to the presence of the cavity inside the airfoil. Once the laser drilling breaks through a nearby wall of the airfoil, continued operation of the laser drill by conventional methods can result in damage to the opposite side of the cavity, possibly resulting in a damaged airfoil that must be refurbished or scrapped.
Accordingly, an improved method and system for drilling a hole in a component of a gas turbine would be beneficial. In particular, a method and system for drilling a hole in a component of a gas turbine and determining one or more operating conditions during such a drilling process would be particularly useful.
BRIEF DESCRIPTION OF THE INVENTION
Aspects and advantages of the invention are set forth below in the following description, or may be apparent from the description, or may be learned from practicing the invention.
The method according to the invention is defined on the basis of claim 1.
In the aforementioned method, the component can be an airfoil of a gas turbine.
In any of the aforementioned methods, the first characteristic of light may be an intensity of light at a first wavelength, the first wavelength being indicative of the confined laser beam striking a first layer of the nearby wall of the component.
Further, the second light property can be a light intensity at a second wavelength, the second wavelength being indicative of the limited laser beam striking a second layer of the nearby wall of the component.
In one embodiment of any of the above-mentioned methods, the first layer can be a thermal barrier coating and the second layer can be a metal part.
In any of the above-mentioned methods, determining the hole advance based on the detected first light property and the detected second light property can be comparing the light intensity detected at the first wavelength with the light intensity detected at the second wavelength, exhibit.
Additionally, determining the hole advance based on the sensed first light property and the sensed second light property may further include determining that the hole is created through the first layer of the proximal wall of the component by at least a predetermined amount based at least in part on that Have comparison of the light intensity detected at the first wavelength with the light intensity detected at the second wavelength.
The last mentioned method may further include adjusting one or more operating parameters of the confined laser drill in response to determining that the hole is created by at least a predetermined amount through the first layer of the nearby wall of the component.
In the method of any type mentioned above, the first sensor can be an optical sensor, wherein the first light property can be a light intensity and wherein the method further comprises determining either a reflected pulse length of the limited laser drill and / or a reflected pulse rate of the limited May have laser drill.
Additionally, the method may further include determining a depth of the hole drilled by the limited laser drill based on either the determined reflected pulse length of the limited laser drill and / or the determined reflected pulse frequency of the limited laser drill.
In addition, the second sensor can be an optical sensor, wherein the second light property can be a wavelength of the light.
Still further in addition, the method may further comprise determining a material into which the limited laser beam is directed based on the wavelength of the light detected by the second sensor.
Still further in addition, the method may further include adjusting one or more operating parameters of the confined laser drill in response to determining the depth of the hole and determining the material into which the confined laser beam is directed.
The invention further discloses a system according to claim 9.
In the aforementioned system, the confined laser beam can define a beam axis, and the first sensor can be positioned to detect light reflected or deflected from the hole along the beam axis.
Additionally, the second sensor can be positioned outside of the component and directed towards the hole such that the second sensor defines a line of sight with the hole.
In any of the above systems, the first sensor can be an oscilloscope.
In any of the aforementioned systems, the component can be an airfoil.
In a preferred embodiment of any of the aforementioned systems, the first light property can be an intensity of light at a first wavelength, wherein the light at the first wavelength can be indicative of the limited laser beam striking a first layer of the nearby wall of the component, wherein the second property of light can be an intensity of light at a second wavelength and wherein light at the second wavelength can be indicative of the confined laser beam striking a second layer of the nearby wall of the component.
In the last-mentioned preferred embodiment, the control device can also be set up to compare the light intensity detected at the first wavelength with the light intensity detected at the second wavelength in order to determine a progress of the hole.
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this invention, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete and enabling disclosure of the present subject matter of the disclosure, including the best mode thereof, for a person skilled in the art is explained in greater detail in the remainder of the description, which includes reference to the accompanying figures, in which:
Figure 1 shows a simplified cross-sectional view of a turbine section of an exemplary gas turbine that may incorporate various embodiments of the present invention.
Figure 2 shows a perspective view of an exemplary airfoil in accordance with an embodiment of the present invention.
FIG. 3 shows a schematic view of a system for manufacturing an airfoil according to an embodiment of the present invention.
Figure 4 shows a schematic view of the exemplary system of Figure 3 after a limited laser beam has penetrated a nearby wall of the airfoil.
Fig. 5 shows a flow diagram of a method for manufacturing an airfoil according to an example of the invention.
Figure 6 is a graph showing light intensity readings during operation of a limited laser drill in accordance with an exemplary embodiment of the present invention.
Figure 7 is a graph showing wavelength readings during operation of a limited laser drill in accordance with an exemplary embodiment of the present invention.
Figure 8 is a graph showing noise in light intensity measurements during operation of a limited laser drill in accordance with an exemplary embodiment of the present invention.
9 shows a schematic view of a system for producing an airfoil according to a further exemplary embodiment of the present invention.
Fig. 10 shows a schematic view of the exemplary system of Fig. 9 after a confined laser beam has penetrated a nearby wall of the airfoil.
FIG. 11 shows a flow diagram of a method for producing an airfoil according to an example of the invention.
Figure 12 shows a schematic view of a system for manufacturing an airfoil in accordance with yet another exemplary embodiment of the present invention.
Figure 13 shows a schematic view of the exemplary system of Figure 12 after a confined laser beam has penetrated a nearby wall of the airfoil.
Figure 14 shows a schematic view of a system for manufacturing an airfoil in accordance with yet another exemplary embodiment of the present invention.
Figure 15 shows a schematic view of the exemplary system of Figure 14 after a limited laser beam has penetrated a nearby wall of the airfoil.
Fig. 16 shows a flow chart of a method for manufacturing an airfoil according to the invention.
Fig. 17 shows a schematic view of a system for manufacturing an airfoil in accordance with yet another exemplary embodiment of the present invention.
Fig. 18 shows a flow chart of a method for manufacturing an airfoil according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided to illustrate the disclosure, not to limit the disclosure. Indeed, it will be apparent to those skilled in the art that various modifications and changes can be made in the present disclosure without departing from the scope or scope of the disclosure. For example, features illustrated or described as part of a single embodiment can be used on another embodiment to yield yet another embodiment. Thus, it is intended that this disclosure cover such modifications and changes as come within the scope of the appended claims and their equivalents. While exemplary embodiments of the present disclosure are generally described in the context of making an airfoil 38 for a turbomachine, for purposes of illustration, one of ordinary skill in the art will readily recognize that embodiments of the present disclosure may and may not be applied to other articles of manufacture are limited to a system 100 or method 120 for manufacturing an airfoil 38 for a turbomachine, unless specifically stated in the claims. For example, other exemplary embodiments of the present invention can be used to make an airfoil 38 for use in the aerospace context or to make other components of a gas turbine.
As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component 38 from another, and are not intended to indicate the location or meaning of the individual components 38. Likewise, the terms “nearby” and “distant” can be used; are used to indicate a relative position of an object or component 38 and are not intended to indicate a function or construction of the object or component 38.
Referring now to the drawings, FIG. 1 shows a simplified cross-sectional side view of an exemplary turbine section 10 of a gas turbine in accordance with various embodiments of the present disclosure. As shown in FIG. 1, the turbine section 10 generally includes a rotor 12 and a housing 14 that at least partially define a gas path 16 through the turbine section 10. The rotor 12 is substantially aligned with an axial centerline 18 of the turbine section 10 and may be connected to a generator, compressor, or other machine to perform work. The rotor 12 may include alternating portions of rotor impellers 20 and rotor spacers 22 that are interconnected by a bolt 24 to rotate together. The housing 14 circumferentially surrounds at least a portion of the rotor 12 to receive a compressed working fluid 26 that flows through the gas path 16. The compressed working fluid 26 may include, for example, combustion gases, compressed air, saturated steam, unsaturated steam, or a combination of these.
As illustrated in Figure 1, the turbine section 10 further includes alternating stages of rotating blades 30 and stationary vanes 32 that extend radially between the rotor 12 and the housing 14. The rotating blades 30 are circumferentially disposed around the rotor 12 and may be connected to the rotor impellers 20 using various means. In contrast to this, the stationary guide vanes 32 can be arranged on the edge around the inside of the housing 14 opposite the rotor spacers 22. The rotating blades 30 and the stationary guide vanes 32 essentially have the shape of an airfoil profile 38 with a concave pressure side, a convex suction side and a leading and a trailing edge, as is known in the art. The compressed working fluid 26 flows along the gas path 16 through the turbine section 10 from left to right, as can be seen in FIG. As the compressed working fluid 26 passes over the first stage of the blades 30, the compressed working fluid expands causing the blades 30, impellers 20, rotor spacers 22, pin 24, and rotor 12 to rotate. The compressed working fluid 26 then flows over the next stage of stationary vanes 32 which accelerate and divert the compressed working fluid 26 to the next stage of blades 30, and the process repeats for the following stages. In the exemplary embodiment illustrated in Figure 1, the turbine section 10 has two stages of stationary vanes 32 between three stages of rotating blades 30; however, one of ordinary skill in the art will readily recognize that the number of stages of rotating blades 30 and stationary vanes 32 is not a limitation on the present disclosure unless specifically stated in the claims.
FIG. 2 shows a perspective view of an exemplary airfoil 38 as may be incorporated into the blades 30 or the stationary vanes 32, according to an embodiment of the present disclosure. As illustrated in Figure 2, the airfoil 38 generally includes a pressure side 42 having a concave curvature and a suction side 44 opposite the pressure side 42 and having a convex curvature. The pressure and suction sides 42, 44 are separated from one another in order to define a cavity 46 in the interior of the airfoil 38 between the pressure and suction sides 42, 44. The cavity 46 may provide a serpentine or tortuous path for a cooling medium to flow within the airfoil 38 to conductively and / or convectively remove heat from the airfoil 38. Additionally, the pressure and suction sides 42, 44 are further joined together to form a leading edge 48 on an upstream portion of the airfoil 38 and a trailing edge 50 downstream of the cavity 46 on a downstream portion of the airfoil 38. Several cooling passages in the pressure side 42, the suction side 44, the leading edge 48 and / or the trailing edge 50 can provide a flow connection with the cavity 46 through the airfoil 38 in order to supply the cooling medium via an outer surface 34 of the airfoil 38. For example, as illustrated in Figure 2, the cooling passages may be located on the leading and trailing edges 48, 50 and / or along either or both of the pressure and suction sides 42, 44. The exemplary airfoil 38 further defines an opening 54 at a base of the airfoil 38, wherein a cooling medium, such as compressed air, can be supplied to the cavity 46 from a compressor section of the gas turbine.
One skilled in the art will readily recognize from the teachings herein that the number and / or location of the cooling passages can vary in accordance with certain embodiments, as can the construction of the cavity 46 and the construction of the cooling passages. Accordingly, the present disclosure is not limited to any particular number or positioning of the cooling passages or any construction of the cooling passages or cavity 46 unless specifically indicated in the claims.
In some exemplary embodiments, a thermal insulation coating 36 can be applied over at least a part of an outer surface 34 of a metal part 40 of the airfoil 38 (see FIG. 3), which covers the underlying metal part 40 of the airfoil 38. The thermal barrier coating 36, when applied, may have low emissivity or high reflectivity to heat, a smooth surface finish, and / or good adhesion to the underlying outer surface 34.
Coaxial acquisition
Referring now to Figures 3 and 4, a perspective view of an exemplary system 60 in accordance with the present disclosure is provided. The system 60 can be used, for example, in the manufacture of a component 38 for a gas turbine. In particular, in the illustrated embodiment, the system 60 is used to make / drill one or more holes 52 or cooling passages in an airfoil 38 of a gas turbine, such as the airfoil 38 discussed above with reference to FIG. It should be recognized, however, that while system 60 is described herein in the context of making airfoil 38, in other exemplary embodiments system 60 may be used in making any other suitable component 38 for a gas turbine. For example, the system 60 can be used in the manufacture of transition pieces, nozzles, combustor liner, effusion or baffle plates, guide vanes 32, shrouds, or any other suitable part.
The exemplary system 60 generally includes a confined laser drill 62 configured to direct a confined laser beam 64 toward a nearby wall 66 of the airfoil 38 to drill a hole 52 in the nearby wall 66 of the airfoil 38 . The confined laser beam 64 defines a beam axis A and the nearby wall 66 is disposed adjacent to the cavity 46. In particular, various embodiments of the confined laser drill 62 may generally include a laser mechanism 68, a collimator 70, and a controller 72. The laser mechanism 68 may include any device capable of generating a laser beam 74. By way of example only, the laser mechanism 68 in some exemplary embodiments may be a diode-pumped Nd: YAG laser capable of generating a laser beam with a pulse frequency of about 10-50 kHz, a wavelength of about one micrometer, or if so Frequency doubling ("SHG", Second Harmonie Generation) is used to generate between 500-550 nanometers and an average power of around 10-200 W. However, in other embodiments, any other suitable laser mechanism 68 may be employed.
In the particular embodiment as illustrated in Figures 3 and 4, the laser mechanism 68 directs the laser beam through a focusing lens 75 onto a collimator 70. The collimator 70 reshapes a diameter of the beam to achieve a better focus feature when the beam is focused into another medium, such as a glass fiber or water. Accordingly, as used herein, the collimator 70 includes any device that constricts and / or directs a bundle of particles or waves to cause the bundle to narrow in cross-section. For example, as illustrated in Figures 3 and 4, the collimator 70 may include a chamber 76 that receives the laser beam along with a fluid such as deionized or filtered water. An orifice or nozzle 78, which may be between about 20 and 150 microns in diameter, directs the laser beam 74 within a column of liquid 80 toward the airfoil 38 to form a confined laser beam 64. The column of liquid 80 can have a pressure of about 907.18 kg to 1,360.78 kg (2,000 to 3,000 pounds) per 6.45 square centimeters (1 square inch). However, the present disclosure is not limited to any particular pressure for the liquid column 80 or diameter for the nozzle 78 unless specifically indicated in the claims. In addition, it should be recognized that, as used herein, approximate terms such as "about" or "approximately" refer to a margin of error within 10%.
As illustrated in the enlarged view in FIGS. 3 and 4, the liquid column 80 can be surrounded by air, for example a protective gas, and serve as a light guiding and focusing mechanism for the laser beam 74. Accordingly, the column of liquid 80 and the laser beam 74 passed through column of liquid 80, as discussed above, may collectively form the confined (constricted) laser beam 64 used by the confined (constricted) laser drill 62 and directed onto the airfoil 38.
As mentioned, the confined laser beam 64 can be used by the confined laser drill 62 to drill one or more cooling passages through the airfoil 38, for example. In particular, the limited laser beam 64 can ablate the outer surface 34 of the airfoil 38, ultimately creating the desired cooling passage through the airfoil 38. In particular, FIG. 3 shows the system 60 before the confined laser beam 64 "breaks" through the nearby wall 66 of the airfoil 38, while FIG. 4 shows the system 60 after the confined laser beam 64 has penetrated the nearby wall 66 of the airfoil 38. As used herein, the terms "breakthrough", "breakthrough" and related terms refer to when the confined laser beam 64 forms a continuous portion of the material forming the nearby wall 66 of the airfoil 38 along the beam axis A of the confined Laser beam 64 has removed. After the confined laser beam 64 has broken through the nearby wall 66 of the airfoil 38, at least a portion of the confined laser beam 64 can pass therethrough, e.g., into the cavity 46 of the airfoil 38.
With continued reference to FIGS. 3 and 4, the system 60 further includes an exemplary anti-kickback mechanism 82. The illustrated exemplary anti-kickback mechanism 82 includes a gas 84 that flows within the airfoil 38. As used herein, the term “gas” can include any gaseous medium. For example, the gas 84 can be an inert gas, a vacuum, a saturated steam, a superheated steam, or any other suitable gas that can form a gaseous flow within the cavity 46 of the airfoil 38. The gas 84 flowing within the airfoil 38 may have a pressure approximately equal to the pressure of the liquid in the liquid column 80 or any other pressure sufficient to perturb the confined laser beam 64. In particular, the gas 84 may have any other pressure sufficient to generate sufficient kinetic moment or velocity to perturb the liquid column 80 within the cavity 46 of the airfoil 38. For example, the gas 84 flowing within the airfoil 38 may, in some exemplary embodiments, have a pressure greater than about 1.72369 bar (25 pounds per square inch), although the present disclosure is not directed to any particular pressure for that Gas 84 is restricted unless specifically stated in the claims.
As best illustrated in FIG. 4, the gas 84 may be directed to cross the confined laser beam 64 within the cavity 46 of the airfoil 38. In certain embodiments, the gas 84 may be oriented substantially perpendicular to the liquid column 80, while in other specific embodiments the gas 84 may be oriented at an oblique or acute angle with respect to the liquid column 80 and / or the limited laser beam 64. As the gas 84 crosses the liquid column 80 inside the airfoil 38, the gas 84 disrupts the liquid column 80 and disperses the confined laser beam 64 inside the cavity 46 of the airfoil 38. In this way, the gas 84 prevents the confined laser beam 64 from breaking up an inner surface of the cavity 46 of the airfoil 38 impinges on the opposite side to the newly created cooling passage in the nearby wall 66. In particular, the gas 84 prevents the confined laser beam 64 from impinging on a distant wall 86 of the airfoil 38.
The exemplary system 60 according to FIGS. 3 and 4 additionally contains a sensor 88 which is functionally connected to the control device 72, which is further explained below. In the embodiment shown, the sensor 88 is set up to detect a light property and to send a signal 68 to the control device 72 which characterizes the detected light property. In particular, the sensor 88 is positioned to sense a property of the light directed along the beam axis A away from the nearby wall 66 of the airfoil 38, such as light reflected and / or deflected by the cooling passage. In some exemplary embodiments, the sensor 88 may be an oscilloscope sensor suitable for detecting one or more of the following properties of light: a light intensity, one or more wavelengths of light, an amount of light, a temporal shape of a light pulse, and a frequency shape of a light pulse. In addition, the sensor 88 for the embodiment shown is offset from the beam axis A and is set up to measure a property of the reflected light along the beam axis A by deflecting at least part of the reflected light that is directed along the beam axis A to the sensor 88 with a Detect deflection lens 90. The deflection lens 90 is positioned in the beam axis A, i.e., intersecting the beam axis A, at an angle of approximately 45 ° to the beam axis A. However, in other exemplary embodiments, the deflecting lens 90 may define any other suitable angle with respect to the beam axis A. Also, although in the embodiment of Figures 3 and 4 the deflecting lens 90 is disposed in the collimator 70, in other embodiments the lens 90 may instead be positioned between the collimator 70 and the focusing lens 75 or alternatively between the focusing lens 75 and the laser mechanism 68. The deflector lens 90 may include a coating on a first side (i.e., the side closest to the proximal wall 66 of the airfoil 38) that redirects at least a portion of the reflected light flowing along the beam axis A to the sensor 88. The coating may be what is referred to as a "one-way" coating so that essentially no light flowing along the beam axis toward the nearby wall 66 of the airfoil 38 is deflected by the lens or its coating. For example, in some embodiments, the coating may be a coating from an electron beam coating (“EBC”).
Still referring to the exemplary system 60 of Figures 3 and 4, the controller 72 may be any suitable processor-based computing device and may be in operative communication with, for example, the limited laser drill 62, the sensor 88, and the kickback protection mechanism 82. For example, suitable controllers 72 may include one or more personal computers, cell phones (including smartphones), personal digital assistants, tablets, laptops, desktops, workstations, game consoles, servers, other computers, and / or any other suitable computing device. As illustrated in Figures 3 and 4, controller 72 may include one or more processors 92 and associated memory 94. The processor (s) 92 may generally be one or more of any suitable processor devices known in the art. Likewise, memory 94 may generally be any suitable computer readable medium or media, including, but not limited to, RAM, ROM, hard drives, flash drives, or other storage devices. As is generally understood, the memory 94 may be configured to store information accessible to the processor (s) 92, including instructions or logic 96 executed by the processor (s) 92 can / can. Instructions or logic 96 can be any set of instructions that, when executed by processor (s) 92, cause processor (s) 92 to provide a desired functionality. For example, the instructions or logic 96 may be software instructions that are rendered in a computer readable form. If software is used, any suitable programming, scripting type, or other suitable language or combinations of languages can be used to implement the teachings contained herein. For example, in particular embodiments of the present disclosure, the instructions or logic 96 may be configured to implement one or more of the methods 120 described below with reference to Figures 5, 11, 16, or 18. Alternatively, the instructions may be implemented by hardwired logic 96 or other circuitry including, but not limited to, application specific circuitry. Additionally, while controller 72 is illustrated schematically as being separate from sensor 88, in other exemplary embodiments, sensor 88 and controller 72 may be integrated into a single device that may be positioned in any suitable location.
Referring now to FIG. 5, a flow diagram of an exemplary method 120 of making an airfoil 38 of a gas turbine is provided. In particular, the flow diagram of Figure 5 illustrates an exemplary method 120 for drilling a hole 52 in an airfoil 38 of a gas turbine. The example method 120 of Figure 5 may be used with the example system 60 shown in Figures 3 and 4 and described above. Accordingly, while the example method 120 is discussed in the context of drilling a hole 52 in an airfoil 38, it may alternatively be used to drill a hole 52 in any other suitable component 38 of a gas turbine.
The method 120 includes, generally at 122, directing a confined laser beam 64 of a confined laser drill 62 toward a nearby wall 66 of the airfoil 38 to drill the hole 52 in the nearby wall 66 of the airfoil 38. The confined laser beam 64 defines a beam axis and the nearby wall 66 is positioned adjacent a cavity defined in the airfoil 38. The method 120 further includes, at 124, sensing a property of light directed away from the airfoil 38 along the beam axis with a sensor 88. The light directed away from the airfoil 38 along the beam axis may, in some aspects, open up obtain the light reflected from the nearby wall 66 of the airfoil 38. In some exemplary aspects, sensing a property of the light at 124 may include sensing at least one of a light intensity, one or more wavelengths of the light, a temporal shape of a light pulse, and a frequency shape of a light pulse. In addition, the sensor 88 may be offset from the beam axis so that sensing a property of the light at 124 may further include deflecting at least a portion of the light directed along the beam axis away from the airfoil 38 to the sensor 88 with a lens.
Still referring to FIG. 5, the example method 120 further includes, at 126, determining one or more operating conditions based on the property of the light sensed by the sensor 88 at 124. The one or more operating conditions include at least one of a depth of the hole 52 being drilled with the confined laser drill 62 and a material into which the confined laser beam 64 of the confined laser drill 62 is directed.
For example, sensing a property of light at 124, in some exemplary embodiments of the present invention, may include sensing an intensity of light. For the purpose of illustration, reference is now also made to FIG. 6, which provides a graphic illustration 150 of exemplary light intensity values that are detected at 124. The example graph 150 shows light intensity on the Y-axis and time on the X-axis. In one such exemplary aspect, determining one or more operating conditions at 126 may include determining either a reflected pulse rate of the limited laser drill 62 or a reflected pulse width (measured in units of time) of the limited laser drill 62, or both, based on the intensity of the beam axis A directed away from the airfoil 38 and detected at 124. For example, as illustrated in Fig. 6, the light intensity detected at 124 during drilling operations - ie during an operation with the limited laser drill 62 - shows heights 152 and depths 154. The reflected pulse rate can thus be determined by counting the number of heights 152 per unit of time and the reflected pulse width can be determined by determining the times of the heights 152.
In particular, in the event that all of the light directed onto the airfoil 38 would be reflected without being absorbed or otherwise changed, the reflected pulse rate and the reflected pulse width would exactly reflect an actual pulse rate and an actual pulse width, with which the limited laser drill 62 and the limited laser beam 64 operate. However, during the drilling operations, an amount of light absorption by the airfoil 38 based, for example, on a depth of the hole 52, an aspect ratio of the hole 52 (which, as used herein, refers to a ratio of the hole diameter to a hole length) and / or the material that the limited laser beam 64 is directed into (ie, the material that is being drilled through) can vary. Accordingly, during the drilling operations, the example method 120 may include comparing the values of either the reflected pulse rate and / or the reflected pulse width, as determined at 126, to known operating conditions of the limited laser drill 62 (e.g., the actual pulse rate and / or the actual pulse width of the limited Laser drill 62) included. Such a comparison can reveal an error value. The error value can then be compared to a look-up table that relates such error values to hole depths - taking into account the particular material being drilled into, the hole diameter, hole geometry and any other relevant factors - by a depth of the hole 52, which being drilled in the nearby wall 66 of the airfoil 38 by the limited laser drill 62. The look-up table values can be determined experimentally.
It should be recognized, however, that in other exemplary embodiments of the present invention, the exemplary method 120 may additionally or alternatively detect other properties of the light directed along the beam axis at 124 and determine other operating conditions at 126. For example, by continuing to refer to FIG. 5 and an exemplary graphical representation 160 of the detected light wavelength values provided in FIG. 7, detecting a light property at 124 may additionally or alternatively include detecting a wavelength of the airfoil 38 along the beam axis away light with the sensor 88 included. In one such exemplary aspect, the one or more operating conditions determined at 126 may include the material into which the confined laser beam 64 of the confined laser drill 62 is directed. Additionally, determining the one or more operating conditions at 126 may include comparing the detected wavelength of light to predetermined values. In particular, different materials absorb and reflect light at different wavelengths. Accordingly, the reflected light directed along the beam axis during drilling operations can define a wavelength that is characteristic of the material into which the limited laser beam 64 is directed. For example, referring specifically to FIG. 7, light directed along the beam axis when drilling into a thermal barrier coating 36 of an airfoil 38 may define a first wavelength 162, while light directed along the beam axis when in FIG a metal portion of the airfoil 38 is drilled into it, can define a second wavelength 164, and light directed along the beam axis after the confined laser beam 64 penetrates the nearby wall 66 of the airfoil 38 can define a third wavelength 166. Accordingly, in one such exemplary aspect, the method 120 may determine the layer into which the confined laser beam 64 is drilling based at least in part on the sensed wavelength of the light reflected along the beam axis.
However, in other exemplary aspects, the method 120 may include sensing the light at multiple wavelengths. For example, light that is directed along the beam axis when drilling through both the thermal barrier coating 36 and the metal part 40 can additionally define a fourth wavelength 163, and light that is directed along the beam axis when drilling through the metal part 40 and when the nearby wall 66 of the airfoil 38 is at least partially broken, can additionally define a fifth wavelength 165. Additionally, in other exemplary embodiments, the light may define any other distinct pattern of wavelengths based on a variety of factors, including the material (s) into which the confined laser drill 62 is directed, the depth of the hole 52 that is being drilled, an aspect ratio of the hole 52 that is being drilled, etc. belong. Accordingly, the method 120 may include using fuzzy logic methodology to determine the one or more operating conditions at 126, including, for example, the material into which the confined laser drill 62 will be directed.
However, in still further exemplary embodiments of the present invention, the example method 120 may additionally or alternatively detect other properties of the light directed along the beam axis at 124 and determine further operating conditions at 126. With continued reference to FIG. 5, as well as an exemplary graphical representation 170 of the detected noise in the light intensity values provided in FIG. 8, the detection of a property of the light at 124 can additionally or alternatively include detecting the noise in the intensity of the light which is directed away from the airfoil 38 along the beam axis, with the sensor 88 included. In particular, the exemplary graphic 170 according to FIG. 8 shows a detected noise level in the light intensity with the line 172 and a detected light intensity with the line 174. In such an exemplary aspect, determining one or more operating conditions at 126 may additionally or alternatively include detecting / determining a noise level in the intensity of the light directed away from the airfoil 38 along the beam axis. As used herein, the term “noise level” refers to a variation in the light intensity or other characteristic sensed by the sensor 88. Additionally, in one such exemplary aspect, determining one or more operating conditions at 126 may further include determining a depth of the hole 52 being drilled based on the determined noise level in the intensity of light directed away from the airfoil 38 along the beam axis. In particular, it has been found that during a limited laser drilling operation in certain airfoils or other components 38 of gas turbines, an increased noise component in the light intensity detected along the beam axis at 124 is due to factors such as the depth of the drilled hole 52 and an aspect ratio of the drilled hole 52, is caused. Accordingly, by detecting the noise level in the intensity of the light directed along the beam axis away from the nearby wall 66 of the airfoil 38, a depth of the hole 52 can be determined by comparing such noise level with, for example, a look-up table, the hole depths with noise levels in the light intensity taking into account the particular hole 52 being drilled and any other relevant factors. These look-up table values can be determined experimentally.
Still referring to FIG. 5, the example method 120 further includes at 128 determining an indicated breakthrough of the confined laser beam 64 of the confined laser drill 62 through the nearby wall 66 of the airfoil 38 of the gas turbine. The indicated breakthrough at 128 may also be determined based on the property of the light detected along the beam axis with the sensor 88 at 124. Referring again to graph 150 of FIG. 6, if the light intensity is detected at 124, the detected light intensity may decrease as the hole 52 is drilled. Accordingly, the example method 120 may determine an indicated breakthrough of the confined laser beam 64 of the confined laser drill 62 through the nearby wall 66 of the airfoil 38 at 128 based on a sensed light intensity falling below a predetermined threshold / breakthrough value. For example, if the predetermined threshold / breakthrough value corresponds to line 156, method 120 may determine a displayed breakthrough at 128 at point 158 on graph 150. This predetermined threshold / breakthrough value can be determined experimentally or based on known values.
The method 120 of FIG. 5 further includes determining at 130 a breakthrough of the limited laser beam 64 through the nearby wall 66 of the airfoil 38 based on, for example, the indicated breakthrough determined at 128 and / or the operating conditions determined at 126. For example, the exemplary method 120 of Figure 5 may determine a breakthrough of the limited laser beam 64 at 130 after determining an indicated breakthrough at 128 and determining one or more operational characteristics at 126. In particular, the exemplary method 120 of FIG. 5 may detect a breakthrough of the limited laser beam 64 at 130 once an indicated breakthrough has been determined at 128, in addition to one or more operating conditions determined at 126 meeting a predetermined criterion - e.g. The depth of the hole 52 is greater than a predetermined value or the material into which the limited laser beam 64 is directed is not the metal part 40 or the thermal barrier coating 36. A method 120 of drilling a hole 52 in accordance with such an example aspect may enable more accurate breakthrough detection when drilling with limited laser.
In particular, although some of the confined laser beam 64 may have penetrated the nearby wall 66 of the airfoil 38, the hole 52 may not be completed. More specifically, the hole 52 may not yet define a desired geometry along an entire length of the hole 52. Accordingly, for the illustrated example aspect, the example method 120 of FIG. 5 further includes, at 132, further directing the confined laser beam 64 toward the nearby wall 66 of the airfoil 38 upon the detection of a breakthrough of the confined laser beam 64 at 130 Continue detection of a light property, such as a light intensity, a light wavelength or a noise in the intensity of the light directed away from the airfoil 38 along the beam axis, with the sensor 88. The method 120 also includes at 134 determining completion of the hole 52 in the nearby wall 66 of the airfoil 38 based on the property of light sensed along the beam axis with the sensor 88. For example, determining the completion of the hole 52 at 134 may include determining an indicated completion based on: the sensed intensity of the reflected light along the beam axis; a reflected pulse rate and / or reflected pulse width of the light reflected along the beam axis; a wavelength of the reflected light on the beam axis; and / or a noise component in the intensity of the light reflected along the one beam axis.
The exemplary method 120 of FIG. 5 further includes, at 136, changing an operating parameter of the limited laser drill 62, such as a power of the limited laser drill 62, a pulse rate of the limited laser drill 62, or a pulse width of the limited laser drill 62, based on that at 126 certain operating condition based on the indicated breakthrough determined at 128 and / or based on the determination of a breakthrough at 130. For example, the method 120 may include changing an operating parameter at 136 in response to a determination that the limited laser beam 64 of the limited laser drill 62 in FIG the metal portion 40 of the airfoil 38 is directed compared to the thermal barrier coating 36 of the airfoil 38, a detection of an indicated breakthrough at 128 and / or a detection of an incipient breakthrough of the confined laser drill 62 at 130.
Sensor positioned outside the component and directed inside the component
Referring now to Figures 9 and 10, a system 60 is provided in accordance with another exemplary embodiment of the present disclosure. In particular, FIG. 9 shows a schematic view of a system 60 in accordance with another exemplary embodiment of the present disclosure before a confined laser beam 64 of a confined laser drill 62 breaks a nearby wall 66 of an airfoil 38, and FIG. 10 shows a schematic view of the exemplary system 60 of FIG. after the confined laser beam 64 of the confined laser drill 62 breaches the nearby wall 66 of the airfoil 38. Although discussed in the context of an airfoil 38, in other embodiments the system 60 may be used with any other suitable component 38 of a gas turbine.
The exemplary system 60, as illustrated in Figures 9 and 10, may be set up in substantially the same manner as the exemplary system 60 of Figures 3 and 4, and the same or similar reference characters may be the same or similar parts describe. For example, the system 60 includes a confined laser drill 62 that uses a confined laser beam 64, the confined laser drill 62 being configured to drill one or more holes or cooling passages in a nearby wall 66 of an airfoil 38. Also, as shown, the proximate wall 66 of the airfoil 38 is positioned adjacent a cavity 46 defined by the airfoil 38. In addition, a kickback protection mechanism 82 is also provided that is configured to protect a distal wall 86 of the airfoil 38, the distal wall 86 being positioned on the opposite side of the cavity 46 from the nearby wall 66.
However, for the embodiment according to FIGS. 9 and 10, a sensor 98 is positioned outside the cavity 46 and directed into the cavity 46 in order to detect a property of light within the cavity 46. As discussed in greater detail below, the system 60 is configured to detect breakthrough of the confined laser beam 64 through the nearby wall 66 of the airfoil 38 based on the property of light sensed within the cavity 46 of the airfoil 38. In some exemplary embodiments, the sensor 98 may be, for example, an optical sensor, an oscilloscope sensor, or any other suitable sensor capable of detecting one or more of the following characteristics of light: an amount of light, an intensity of light, and a wavelength of light.
For the illustrated embodiment, the sensor 98 is positioned outside of the airfoil 38 so that the sensor 98 defines a line of sight 100 to the beam axis A of the limited laser beam 64. As used herein, the term "line of sight" means a straight line from one position to another position that is free of any structural obstruction. Accordingly, the sensor 98 can be positioned anywhere outside the cavity 46 of the airfoil 38 that enables the sensor 98 to define the line of sight 100 to the beam axis A within the cavity 46. For example, in the embodiment shown, the sensor 98 is positioned adjacent to the opening 54 (shown schematically) of the airfoil 38 and is directed through the opening 54 of the airfoil 38 into the cavity 46 of the airfoil 38.
Usually, it is difficult to detect light from a laser beam 74 unless such a laser beam 74 contacts a surface (for example, when the light is reflected and / or deflected) or unless the sensor 98 is aligned with an axis of the laser beam 74 is positioned in alignment. For the illustrated embodiment, the kickback protection mechanism 82 is configured to interfere with the confined laser beam 64 within the cavity 46 of the airfoil 38 after the confined laser beam 64 has broken through the nearby wall 66 of the airfoil 38. In particular, as noted above, the confined laser beam 64 includes a column of liquid 80 and a laser beam 74 within the column of liquid 80. With particular reference to FIG The cavity 46 is flowed by the backlash prevention mechanism 82, the liquid column 80 of the confined laser beam 64 within the cavity 46 of the airfoil 38 in such a manner that at least a portion of the liquid from the liquid column 80 intersects the beam axis A and the laser beam 74. The liquid intersecting the beam axis A can be at least partially irradiated by the limited laser beam 64 within the cavity 46. Accordingly, the sensor 98, which is directed into the cavity 46 of the airfoil 38, can detect a light property, such as a light intensity, from the portion of the liquid irradiated by the laser beam 74.
In some embodiments, the sensor 98 may be positioned outside the cavity 46 and directed into the cavity 46 such that the sensor 98 is configured to detect light from the interior of the cavity 46 of the airfoil 38 at multiple locations. In particular, the sensor 98 can be positioned outside the cavity 46 and directed into the cavity 46 such that the sensor 98 has a line of sight 100 with the beam axis A of the limited laser beam 64 at a first hole location and with a second beam axis A 'of the limited laser beam 64 defined at a second hole location (see. Fig. 10). Such an embodiment can allow time-efficient and more convenient drilling of, for example, cooling holes in an airfoil 38 for a gas turbine.
Referring now to Figure 11, a block diagram of an example method 200 for drilling a hole 52 in an airfoil 38 of a gas turbine is provided. The example method 200 of Figure 11 may be used with the example system 60 shown in Figures 9 and 10 and described above. Accordingly, while the example method 200 is described in the context of drilling a hole 52 in an airfoil 38, it may alternatively be used to drill a hole 52 in any other suitable component 38 of a gas turbine.
As illustrated, the example method 200 includes, at 202, directing a confined laser beam 64 of a confined laser drill 62 toward a first hole location on a nearby wall 66 of the airfoil. The nearby wall 66 may be positioned adjacent a cavity defined in the airfoil 38. The method 200 further includes, at 204, sensing a property of light within the cavity defined by the airfoil 38 using a sensor 98 positioned outside the cavity defined by the airfoil 38. In some exemplary aspects, the sensor 98 may be positioned adjacent an opening 54 defined by the airfoil 38 and directed through the opening 54 into the cavity. The sensor 98 can thus be positioned at a location that does not intersect a beam axis defined by the confined laser beam 64, but a line of sight to the beam axis defined by the confined laser beam 64 within the airfoil cavity 38 defined.
The method 200 further includes activating a kickback protection mechanism at 206. Activation of the kickback protection mechanism at 206 may be in response to, for example, operating the limited laser drill 62 for a predetermined period of time. In addition, activating the anti-kickback mechanism at 206 may include flowing a gas through the airfoil 38 cavity in such a manner that the gas crosses the jet axis within the airfoil 38 cavity. Accordingly, if the confined laser beam 64 of the confined laser drill 62 breaks the nearby wall 66 of the airfoil 38, the method 200 further includes, at 208, perturbing the confined laser beam 64 within the cavity of the airfoil 38 with the kickback protection mechanism. In particular, perturbing the confined laser beam 64 within the cavity at 208 may include perturbing a liquid column of the confined laser beam 64 such that a liquid from the liquid column intersects the beam axis of the confined laser beam 64. The liquid intersecting the beam axis can be at least partially irradiated by the laser beam 74 within the cavity of the airfoil 38.
The exemplary method 200 of Figure 11 further includes at 210 determining a first breakthrough of the confined laser beam 64 through the nearby wall 66 of the airfoil 38 at the first hole location based on the light sensed by the sensor 98 at 204 from within the cavity . In some exemplary aspects, sensing a property of light at 204 within the cavity with the sensor 98 may include sensing an intensity of light from the portion of the liquid of the limited laser beam 64 that is irradiated by the laser of the limited laser beam 64. Further, in such an exemplary aspect, determining the first breakthrough of the limited laser beam 64 at 210 may include determining the first breakthrough of the limited laser beam 64 based on the detected light intensity from the portion of the liquid of the limited laser beam 64 that is irradiated by the laser beam of the limited laser beam is included.
After determining the first breakthrough of the limited laser beam at 210, the example method 200 may include turning off the limited laser drill 62 and repositioning the limited laser drill 62 to drill a second cooling hole. The example method 200 also includes, at 212, directing the limited laser beam of the limited laser drill 62 toward a second hole location on the nearby wall 66 of the airfoil 38. The method 200 further includes, at 214, sensing a property of light within that defined by the airfoil 38 Cavity using the sensor 98 after directing the confined laser beam toward the second hole position at 212. Further, the method 200 of FIG. 11 includes at 216 detecting a second breakthrough of the confined laser beam through the nearby wall 66 of the airfoil 38 based on FIG detected light property from the interior of the cavity. The determination of the second breakthrough of the limited laser beam at 216 may be performed in a manner that is substantially similar to the determination of the first breakthrough of the limited laser beam at 210. In addition, for the exemplary aspect illustrated, the sensor 98 remains stationary between the detection of the first breakthrough of the limited laser beam at 210 and the detection of the second breakthrough of the limited laser beam at 216. For example, the sensor 98 may be positioned to define a line of sight with the beam axis of the limited laser beam at multiple hole positions (including the first hole position and the second hole position). It should be recognized, however, that in other exemplary aspects, the sensor 98 can be moved, repositioned, or reoriented to maintain or create a line of sight to subsequent hole locations if, for example, the cooling holes being drilled define a non-linear path.
The exemplary method 200 of FIG. 11 may enable more time efficient and convenient drilling of multiple holes through the nearby wall 66 of the airfoil 38 using a limited laser drill 62.
Capture the liquid outside the component
Referring now to Figures 12 and 13, a system 60 is provided in accordance with yet another exemplary embodiment of the present disclosure. In particular, Figure 12 shows a schematic view of a system 60 in accordance with another exemplary embodiment of the present disclosure before a confined laser beam 64 from a confined laser drill 62 has breached a nearby wall 66 of an airfoil 38. Additionally, FIG. 13 shows a schematic view of the exemplary system 60 of FIG. 12 after the confined laser beam 64 of the confined laser drill 62 has penetrated the nearby wall 66 of the airfoil 38. It should be recognized that while the exemplary system 60 of Figures 12 and 13 is illustrated in the context of an airfoil 38, in other embodiments the system 60 can be used with any other component 38 of a gas turbine.
The exemplary system 60 as illustrated in FIGS. 12 and 13 can be set up in substantially the same manner as the exemplary system 60 according to FIGS. 3 and 4, and the same or similar reference numerals can refer to the same or refer to similar parts. For example, the exemplary system 60 of FIGS. 12 and 13 includes a confined laser drill 62 (shown schematically in FIGS. 12 and 13 for simplicity) that employs a confined laser beam 64. The limited laser beam 64 includes a liquid column 80 formed from a liquid and a laser beam 74 within the liquid column 80. The constrained laser drill 62 is configured to drill one or more holes 52 or cooling passages through a nearby wall 66 of the airfoil 38. For the illustrated embodiment, the proximate wall 66 of the airfoil 38 is positioned adjacent a cavity 46 defined by the airfoil 38.
However, for the embodiment of Figures 12 and 13, the system 60 includes a sensor 102 positioned outside the nearby wall 66 of the airfoil 38 that is configured to detect an amount of liquid from the confined laser beam 64 that is outside the nearby wall 66 of the airfoil 38 exists, to be determined. A control device 72 is in operative communication with the sensor 102. The control device 72 is configured to detect a breakthrough of the limited laser beam 64 through the nearby wall 66 of the airfoil 38 based on the amount of liquid determined by the sensor 102 to be present. In particular, before the confined laser beam 64 breaks through the nearby wall 66 of the airfoil 38, fluid from the liquid column 80 of the confined laser beam 64 may splash back away from the nearby wall 66 of the airfoil 38 during the drilling operation (i.e., during the operation with the confined laser drill 62) . The liquid from the confined laser beam 64 may form a plume 106 of splash back liquid surrounding the hole 52 just drilled in the nearby wall 66 of the airfoil 38. The flag 106 may be disposed in a splashback area 104 defined by the system 60. Additionally, in some exemplary embodiments, such as the embodiment of FIGS. 12 and 13, the confined laser drill 62 may be positioned within relatively close proximity to the nearby wall 66 of the airfoil 38 such that the confined laser drill 62 is positioned within the splashback area 104 is. For example, in some embodiments, the limited laser drill 62 may define a distance to the nearby wall 66 of the airfoil 38 between about 5 millimeters and about 25 mm, for example between about 7 mm and about 20 mm, for example between about 10 mm and about 15 mm . However, in other embodiments, the limited laser drill 62 may define any other suitable distance from the nearby wall 66 of the airfoil 38.
In contrast, after the confined laser drill 62 breaks the nearby wall 66 of the airfoil 38 (Fig. 13), fluid from the liquid column 80 of the confined laser beam 64 can pass through the drilled hole 52 and into the airfoil cavity 46 38 flow in. Accordingly, after the confined laser beam 64 penetrates the nearby wall 66 of the airfoil 38, the confined laser drill 62 may not define the plume 106 of splashback liquid in the splashback area 104, or alternatively, the plume 106 may be smaller or otherwise a different shape in comparison to define their size and shape before the confined laser beam 64 breached the nearby wall 66 of the airfoil 38.
For the embodiment according to FIGS. 12 and 13, the sensor 102 can be configured as any sensor capable of determining an amount of liquid from the confined laser beam 64 that is present outside the nearby wall 66 of the airfoil 38 . For example, in some example aspects, sensor 102 may include a camera. If the sensor 102 includes a camera, the camera of the sensor 102 can be aimed at the limited laser beam 62, or alternatively, the camera of the sensor 102 can be aimed at the hole 52 in the nearby wall 66 of the airfoil 38. In each of these embodiments, the sensor 102 can be configured to use an image recognition method to determine whether or not a predetermined amount of liquid is present in the splashback region 104. For example, the sensor 102 may be configured to compare one or more images received by the camera of the sensor 102 with one or more stored images in order to determine the amount of liquid that is present. In particular, the sensor 102 may be configured to match one or more images received by the camera with one or more stored images of the confined laser drill 62 or the hole 52 with an amount of fluid present that is indicative of the confined laser beam 64 the nearby wall 66 of the airfoil 38 has broken through.
However, it should be recognized that in other exemplary embodiments, any other suitable sensor 102 may be provided. For example, in other exemplary embodiments, the sensor 102 may be a motion sensor, a humidity sensor, or any other suitable sensor. For example, if the sensor 102 is a motion sensor, the sensor 102 can determine whether or not a plume 106 of the splashed-back liquid is present in the splashback area 104. A breakthrough can be determined when the plume 106 of the back-sprayed liquid is no longer present in the back-splash area 104.
Referring now to Figures 14 and 15, a system 60 is provided in accordance with yet another exemplary embodiment. The exemplary system 60 of FIGS. 14 and 15 is set up in substantially the same manner as the exemplary system 60 of FIGS. 12 and 13. However, for the exemplary embodiment of FIGS. 14 and 15, the sensor 102 is configured as an optical sensor and the system 60 further includes a light source 108 that is separate from the limited laser drill 62. The light source 108 can be any suitable light source. For example, the light source 108 can be one or more LED light bulbs, one or more incandescent lamps, one or more electroluminescent lamps, one or more lasers, or combinations of these.
As noted, the confined laser drill 62 defines a splashback area 104 in which liquid splashes from the confined laser beam 64 before the confined laser beam 64 breaks the nearby wall 66 of the airfoil 38. For the embodiment shown, the light source 108 is positioned outside of the airfoil 38 and is set up to direct a light through at least part of the splashback region 104. In addition, the light source 108 for the embodiment shown is positioned directly on the opposite side of the splashback area 104 to the sensor 102, the light source 108 being directed at the sensor 102 and the sensor 102 being directed at the light source 108. However, in other exemplary embodiments, the light source 108 and the sensor 102 may be offset from one another with respect to the splashback region 104, the light source 108 may not be directed towards the sensor 102 and / or the sensor 102 may not be directed towards the light source 108.
As mentioned, the sensor 102 for the illustrated embodiment is directed at the light source 108, and the light source 108 is directed at the sensor 102 so that an axis of the light source intersects the sensor 102. In such an embodiment, sensing an intensity of light above a predetermined threshold may indicate that there is a decreased amount of fluid from the confined laser beam 64 outside of the airfoil 38 and, thus, that the confined laser beam 64 has breached the nearby wall 66 of the airfoil 38. If liquid is present in the splashback region 104, in particular such a liquid can interfere or deflect light from the light source 108, so that a light intensity detected by the sensor 102 is relatively low. In contrast to this, if there is no liquid or a minimal amount of liquid in the splashback region 104, the degree of interference between the light source 108 and the sensor 102 is limited, so that a relatively high light intensity can be detected by the sensor 102. Accordingly, with such a configuration, sensing a relatively high light intensity may indicate that the confined laser beam 64 has breached the nearby wall 66 of the airfoil 38.
In further exemplary embodiments, if, for example, the light source 108 is not directed at the sensor 102 and the sensor 102 is not directed at the light source 108, however, the detection of a light intensity below a predetermined threshold indicates that a reduced amount of liquid from the limited laser beam 64 is present outside of the airfoil 38. In particular, if the light source 108 is not directed at the sensor 102 and the sensor 102 is not directed at the light source 108, the sensor 102 can detect an increased light intensity if light from the light source is deflected and reflected by the liquid in the splashback area 104. However, if there is no liquid or a minimal amount of liquid in the splash back area 104, light from the light source will not be deflected or reflected by such liquid, and the sensor 102 can consequently detect a relatively low light intensity. Accordingly, in one such exemplary embodiment, sensing an intensity of light below a predetermined threshold may indicate that the confined laser beam 64 has breached the nearby wall 66 of the airfoil 38.
Referring now to FIG. 16, a block diagram of an exemplary method 300 for drilling a hole 52 in an airfoil 38 of a gas turbine is provided. The example method 300 of FIG. 16 can be used with the example system 60 shown in FIGS. 13, and / or the exemplary system 60 shown in FIGS. 14 and 15, both of which are described above. Accordingly, while the example method 300 is discussed in the context of drilling a hole 52 in an airfoil 38, it may alternatively be used to drill a hole 52 in any other suitable component 38 of a gas turbine.
As illustrated, the example method 300 includes, at 302, positioning a confined laser drill 62 within a predetermined distance of a nearby wall of an airfoil 38 of a gas turbine. The example method 300 further includes, at 304, directing a confined laser beam 64 of the confined laser drill 62 toward an outer surface of the nearby wall of the airfoil 38. The confined laser beam 64 includes a column of liquid formed from a liquid and a laser beam within the column of liquid . The example method 300 further includes at 306 sensing an amount of liquid present outside the nearby wall of the airfoil 38 from the confined laser beam with a sensor 102. The example method 300 also includes at 308 determining a breakthrough of the confined laser beam of the confined Laser drill 62 through the near wall 66 of the airfoil 38 of the gas turbine based on an amount of fluid sensed outside the near wall 66 of the airfoil 38 at 306.
In some exemplary aspects where the sensor includes a camera, sensing an amount of fluid present outside the nearby wall 66 of the airfoil 38 at 306 may be a comparison of one or more images received from the camera to one or more stored images to determine the amount of fluid that is present. Any suitable pattern recognition software can be used to provide such functionality.
Use of multiple sensors
Referring now to FIG. 17, a system 60 is provided in accordance with another exemplary embodiment of the present disclosure. It should be recognized that while the exemplary system 60 of Figure 17 is illustrated in the context of an airfoil 38, in other embodiments the system 60 can be used with any other component 38 of a gas turbine.
The exemplary system 60 of FIG. 17 may be implemented in substantially the same manner as the exemplary system 60 of FIGS. 3 and 4, and the same or similar reference numbers may refer to the same or similar parts. For example, the exemplary system 60 of FIG. 17, a limited laser drill 62 employing a limited laser beam 64. The limited laser beam 64 is configured to drill a hole 52 through a nearby wall 66 of the airfoil 38. The nearby wall 66, as illustrated, is positioned adjacent a cavity 66 defined by the airfoil 38. The system 60 also includes a controller 72.
The exemplary system 60 of FIG. 17 further includes a first sensor 110 configured to sense a first property of the light from the hole 52 in the nearby wall 66 of the airfoil 38. The exemplary system 60 also includes a second sensor 112 configured to sense a second property of the light from the hole 52 and the nearby wall 66 of the airfoil 38. The second property of light is different from the first property of light. In addition, the controller 72 is operably connected to the first sensor 110 and the second sensor 112 and is configured to measure an advance of the hole 52 drilled with the limited laser drill 62 based on the sensed first light property and the sensed second light property determine.
For the embodiment illustrated in FIG. 17, the first sensor 110 is positioned outside of the airfoil 38 and is also positioned to detect light reflected and / or deflected by the hole 52 along a beam axis A, ie along the The jet axis A is directed away from the nearby wall 66 of the airfoil 38. For example, the first sensor 110 can be set up essentially in the same way as the sensor 88, which is described above with reference to FIGS. 3 and 4. Accordingly, the first sensor 110 can be an oscilloscope sensor or any other suitable optical sensor.
In addition, for the embodiment according to FIG. 17, the second sensor 112 is also positioned outside of the airfoil 38 and directed towards the hole 52 in the nearby wall 66 of the airfoil 38. In particular, the second sensor 112 is positioned such that the second sensor 112 defines a line of sight 114 with the hole 52, the line of sight 114 extending in a direction non-parallel to the beam axis A. In some embodiments, the second sensor 112 may be an optical sensor that is configured to detect one or more of a light intensity, a light wavelength, and an amount of light.
As described in more detail below with reference to Figs. 18-18, in some exemplary embodiments, the first characteristic of light can be an intensity of light at a first wavelength and the second characteristic of light can be an intensity of light at a second wavelength. Detection of the light at the first wavelength can be indicative of the limited laser beam 64 impinging on a first layer, such as a thermal barrier coating 36, of the nearby wall 66 of the airfoil 38. In contrast, the detection of a light at the second wavelength can be indicative of the limited laser beam 64 impinging on a second layer, such as a metal part 40, of the nearby wall 66 of the airfoil 38. The control device 72 can be configured to compare the light intensity that is detected at the first wavelength by the first sensor 110 with the light intensity that is detected at the second wavelength by the second sensor 112 in order to determine a progression of the hole 52 determine.
It should be recognized, however, that in other exemplary embodiments of the present disclosure, the first sensor 110 and the second sensor 112 may be positioned in any other suitable location. For example, in other exemplary embodiments, the first sensor 110 and the second sensor 112 may each be positioned to detect light directed along the beam axis A away from the nearby wall 66 of the airfoil 38. Alternatively, the first sensor 110 and second sensor 112 may each be positioned such that each respective sensor 110, 112 defines a line of sight to the hole 52 in the nearby wall 66 of the airfoil 38 that is not parallel to the beam axis A. Alternatively, one or both of the first sensor 110 and the second sensor 112 may be positioned outside the cavity 46 of the airfoil 38 and directed into the cavity 46 of the airfoil 38 (similar, for example, to the sensor 98 described above with reference 9 and 10) or can be positioned within the cavity 46 of the airfoil 38. Alternatively, one or both of the first sensor 110 and the second sensor 112 may be positioned outside of the airfoil 38 and directed at a surrounding surface to detect light reflected from the hole 52 onto the surrounding surface. In yet another alternative, in some exemplary embodiments, the first sensor 110 and the second sensor 112 can both be integrated into a single sensing device at any suitable location.
Referring now to Figure 18, a block diagram of an exemplary method 400 for drilling a hole 52 in an airfoil 38 of a gas turbine is provided. The example method 400 of Figure 10 may be used with the example system 60 illustrated in Figure 17 and described above. Accordingly, while the example method 400, while discussed in the context of drilling a hole 52 in an airfoil 38, may alternatively be used to drill a hole 52 in any other suitable airfoil 38 of a gas turbine.
The exemplary method 400 of FIG. 18 includes, at 402, directing a confined laser beam 64 of a confined laser drill 62 toward a nearby wall 66 of the airfoil. The nearby wall 66 is positioned adjacent a cavity defined in the airfoil 38 and the confined laser beam 64 defines a beam axis. The example method 400 further includes, at 404, sensing a first characteristic of light from the hole 52 in the airfoil 38 with a first sensor 110. In some example aspects, the first sensor 110 may be positioned outside the airfoil 38 and the first characteristic of light may be a light intensity at a first wavelength. The sensing of the light at the first wavelength may be indicative of the limited laser beam 64 impinging or being directed to a first layer of the nearby wall 66 of the airfoil 38. For example, the detection of the light at the first wavelength may be indicative of the limited laser beam 64 impinging on a thermal barrier coating 36 on the nearby wall 66 of the airfoil 38.
The example method 400 further includes, at 406, sensing a second characteristic of light from the hole 52 in the airfoil 38 with a second sensor 112. The second characteristic of light, sensed with the second sensor 112 at 406, is different from the first characteristic of light that is detected with the first sensor 110 at 404. For example, in some exemplary aspects, the second characteristic of light can be an intensity of light at a second wavelength. The second wavelength may be indicative of the limited laser beam 64 impinging on a second layer of the nearby wall 66 of the airfoil 38. For example, the detection of the light at the second wavelength may be indicative of the limited laser beam 64 impinging on a metal portion 40 of the nearby wall 66 of the airfoil 38.
The method 400 further includes at 408 determining a hole advance based on the first characteristic of light detected at 404 and the second characteristic of light detected at 406. In some example aspects, determining hole advance at 408 based on the first characteristic of light detected at 404 and the second characteristic of light detected at 406 may be a comparison of the light intensity detected at the first wavelength with a Light intensity detected at the second wavelength. For example, a ratio of the light intensity detected at the first wavelength to the light intensity detected at the second wavelength may indicate progress of the hole 52 through the first layer of the nearby wall 66 of the airfoil 38.
In some example aspects, determining the hole advance at 408 based on the first property of light detected at 404 and the second property of light detected at 406 may further include determining that the hole 52 is at least a predetermined amount through the first layer of the nearby Wall 66 of the airfoil 38 is created. For example, the example method 400 may include determining that the hole 52 penetrates at least about 90% through the first layer of the proximal wall 66 of the airfoil 38, such as at least about 95% through the first layer of the proximal wall 66 of the airfoil 38, for example, is created by at least about 98% through the first layer of the adjacent wall 66 of the airfoil 38.
In addition, depending on certain factors such as the type of material from which the thermal barrier coating 36 is made, it may be desirable to pass through the thermal barrier coating 36 of the nearby wall 66 of the airfoil 38 with less power than the underlying metal portion 40 of the blade 38 to drill. Accordingly, in response to determining the hole advance at 408, e.g., in response to a determination that the hole 52 is created through the first layer of the nearby wall 66 of the airfoil 38 by at least a predetermined amount, the method 400 may further adjust at 410 one or more operating parameters of the limited laser drill 62. For example, method 400 may include increasing a power, increasing a pulse rate, and / or increasing a pulse width of the limited laser drill 62.
It will be recognized, however, that in other exemplary aspects, the first characteristic of light and the second characteristic of light may each be any other suitable characteristic of light. For example, in other exemplary aspects, the first sensor 110 can be a suitable optical sensor, and the first light characteristic can be a light intensity. Such an example aspect may further include determining either a reflected pulse width of the limited laser drill 62 and / or a reflected pulse frequency of the limited laser drill 62. Similar to the manner discussed in greater detail above with reference to Figures 3 through 5, the exemplary method 400 of Figure 18 may be based on the determined reflected pulse width of the limited laser drill 62 and / or the determined pulse frequency of the limited laser drill 62 further include determining a depth of the hole 52 being drilled with the localized laser drill 62. In addition, in such an exemplary aspect, the second sensor 112 can also be an optical sensor, and the second light property can be a wavelength of the light. As mentioned, the wavelength of the light for the material into which the limited laser beam 64 is directed can be labeled. Accordingly, the example method 400 of FIG. 18 may further include determining a material into which the limited laser beam 64 is directed based on the wavelength of light sensed by the second sensor 112.
In one such example aspect, the example method 400 of FIG. 18 may further adjust one or more operating parameters of the limited in response to determining the depth of the hole 52 and determining the material into which the limited laser beam 64 is directed Laser drill 62 included. In particular, the example method 400 of Figure 18 may further include determining that the hole 52 has been drilled through the first layer of the proximate wall 66 of the airfoil 38 and increasing a power, increasing a pulse rate, and / or increasing a pulse width of the limited laser drill 62 to aid in drilling through the metal portion 40 of the nearby wall 66 of the airfoil 38. Alternatively, the exemplary method 400 of FIG. 18 further includes determining that the hole 52 is created by the metal portion 40 of the proximal wall 66 of the airfoil 38 by at least a predetermined amount and may decrease power, decrease a pulse rate, and / or decrease a pulse width of the limited laser drill 62 by a to prevent unnecessary damage, for example to a remote wall of the airfoil 38.
In any of the foregoing exemplary aspects, it should be recognized that determining hole advance at 408 based on the first property of light detected at 404 and the second property of light detected at 406 may include using any suitable control methodology. For example, determining hole advance at 408 may include using lookup tables taking certain factors into account. These look-up tables can be determined experimentally. Additionally or alternatively, determining the hole advance at 408 may include using a fuzzy logic control methodology to analyze the first and second light properties detected at 404 and 406, respectively.
This written description uses examples to disclose the invention and to enable any person skilled in the art to practice the invention. The patentable scope of the invention is defined by the claims.
[0118] A method of drilling a hole 52 in a component 38 is provided. The method includes directing a confined laser beam 64 of a confined laser drill 62 toward a nearby wall 66 of the component 38 and sensing a first property of light from the hole 52 in the nearby wall 66 of the component 38 with a first sensor 110 that is external to the component 38 is positioned. The method further includes sensing a second property of light from the hole 52 in the nearby wall 66 of the component 38 with a second sensor 112. The second property of light is different from the first property of light. The method also includes determining a hole advance on the basis of the detected first light property and the detected second light property.

权利要求:
Claims (10)
[1]
A method (120, 200, 300, 400) for drilling a hole (52) in a wall (66) of a component (38), the method (120, 200, 300, 400) comprising:directing a laser beam (64) confined by a light guiding and focusing mechanism of a laser drill (62) towards a first hole position on the wall (66) of the component (38); Detecting a first characteristic of light from the hole (52) in the wall (66) of the component (38) with a first sensor (110) positioned outside the component (38); Detecting a second characteristic of light from the hole (52) in the wall (66) of the component (38) with a second sensor (112), the second characteristic of light being different from the first characteristic of light;Determining a hole advance on the basis of the detected first light property and the detected second light property.
[2]
2. The method (120, 200, 300, 400) according to claim 1, wherein the component (38) is an airfoil (38) of a gas turbine; and / or wherein a first layer is a thermal insulation coating (36) and wherein a second layer is a metal part (40).
[3]
3. The method (120, 200, 300, 400) according to claim 1 or 2, wherein the first light property is a light intensity at a first wavelength,wherein the first wavelength is indicative of the limited laser beam (64) striking a first layer of the wall (66) of the component (38); wherein the second property of light is preferably an intensity of light at a second wavelength, the second wavelength being indicative of the limited laser beam (64) striking a second layer of the wall (66) of the component (38).
[4]
4. The method (120, 200, 300, 400) according to claim 3, wherein the determination of the hole advance on the basis of the detected first light property and the detected second light property is a comparison of the light intensity detected at the first wavelength with the light intensity detected at the second wavelength having.
[5]
5. The method (120, 200, 300, 400) according to claim 4, wherein determining the hole progress based on the detected first light property and the detected second light property further a determining that the hole (52) by at least a predetermined amount through the first layer of the wall (66) of the component (38) is created based at least in part on comparing the light intensity detected at the first wavelength with the light intensity detected at the second wavelength; wherein the method (120, 200, 300, 400) preferably further comprises adjusting one or more operating parameters of the limited laser drill (62) in response to determining that the hole (52) penetrates at least a predetermined amount through the first layer of the wall ( 66) of the component (38) is created.
[6]
6. The method (120, 200, 300, 400) according to any one of the preceding claims, wherein the first sensor (110) is an optical sensor, wherein the first light property is a light intensity and wherein the method (120, 200, 300, 400 ) further comprises determining either a reflected pulse length of the limited laser drill (62) and / or a reflected pulse rate of the limited laser drill (62); wherein the method (120, 200, 300, 400) preferably further comprises determining a depth of the hole (52) drilled by the confined laser drill (62) based on the determined reflected pulse length of the confined laser drill (62) and / or the determined reflected pulse frequency of the limited laser drill (62).
[7]
7. The method (120, 200, 300, 400) according to claim 6, wherein the second sensor (112) is an optical sensor and wherein the second light property is a wavelength of the light.
[8]
The method (120, 200, 300, 400) of claim 7, further comprising determining a material into which the confined laser beam (64) is directed based on the wavelength of the light detected by the second sensor (112) ; wherein the method (120, 200, 300, 400) preferably further includes adjusting one or more operating parameters of the confined laser drill (62) in response to determining the depth of the hole (52) and determining the material into which the confined laser beam ( 64) is directed into it.
[9]
9. A system (60) for drilling a hole (52) in a wall (66) of a component (38), the system (60) comprising:a laser drill (62) limited by means of a light guiding and focusing mechanism, which uses a laser beam (64) limited by means of the light guiding and focusing mechanism, the limited laser drill (62) being adapted to drill the hole (52) through the wall ( 66) drilling the component (38) with the wall (66) positioned adjacent a cavity (46) defined by the component (38);a first sensor (110) positioned outside the component (38) and configured to sense a first property of light from the hole (52) in the wall (66) of the component (38);a second sensor (112) configured to detect a second property of light from the hole (52) in the wall (66) of the component (38), the second property of light being different from the first property of light; anda control device (72) operatively connected to the first sensor (110) and the second sensor (112), the control device (72) being configured to determine a progression of the hole (52) based on the detected first light property and the to determine detected second light property.
[10]
The system (60) of claim 9, wherein the confined laser beam defines a beam axis and wherein the first sensor (110) is positioned to detect light reflected or deflected by the hole (52) along the beam axis;wherein the second sensor (112) is preferably positioned outside the component (38) and directed towards the hole (52) such thatthe second sensor (112) defines a line of sight with the hole (52); wherein the first sensor (110) is preferably an oscilloscope; wherein the component (38) is preferably an airfoil (38).

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CN105772954A|2016-07-20|

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US20160199942A1|2016-07-14|

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JP6732452B2|2020-07-29|

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JP2016125499A|2016-07-11|

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DE102016100167A1|2016-07-14|

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CH710618A2|2016-07-15|

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CN105772954B|2020-04-24|

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法律状态:
2017-03-15| NV| New agent|Representative=s name: GENERAL ELECTRIC TECHNOLOGY GMBH GLOBAL PATENT, CH |

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2019-05-31| NV| New agent|Representative=s name: FREIGUTPARTNERS IP LAW FIRM DR. ROLF DITTMANN, CH |

优先权:

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申请号 | 申请日 | 专利标题

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US14/592,232|US20160199942A1|2015-01-08|2015-01-08|Method and system for confined laser drilling|

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