• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention relates to a method for operating a metering device (1) which has a metering screw (3) arranged in a metering channel (2), which has a transport section (4) which forms a flight and which has a closing region (5) , which is suitable for closing the metering channel (2). The method comprises detecting an amount of material which has already been dispensed by the metering device (1) during a metering operation, and controlling a material flow through the metering channel (2) by moving the metering screw (3) in an axial direction of the metering screw (FIG. 3) to define a width of a metering gap, which is a gap between the metering channel (2) and the end portion (5) of the metering screw (3), wherein the width of the metering gap is selected depending on the detected amount of material.
    公开号:CH713772A2
    申请号:CH00181/18
    申请日:2018-02-15
    公开日:2018-11-15
    发明作者:Burk Tobias
    申请人:Bosch Gmbh Robert；
    IPC主号:
    专利说明:

    Description: PRIOR ART The present invention relates to a metering device and a method for operating a metering device.
    The screw dosing is a common dosing method for powdery substances and granules. In this case, a material to be metered is transported from a metering container by means of a rotating metering screw through a metering channel in order to fall into a metering container at the end of the metering channel. Such a screw feeder is usually used when a particularly accurate metering of the material is to take place. Thus, such a dosing is used in particular in a dosage of powders, adhesives and active ingredients. Exemplary powders are, for example, pigments or fillers for paints. Active ingredients are often dosed in the field of crop protection or the pharmaceutical industry by means of the screw dosing.
    From DE 19 962 475 C2 it is disclosed for the field of bottling plants that a width of a gap between a closure member of a spindle and a filling tube is changed based on a time course.
    DISCLOSURE OF THE INVENTION The method according to the invention for operating a metering device which has a metering screw arranged in a metering channel, which has a transport section which forms a screw thread and which has a closing region which is suitable for closing the metering channel detecting a quantity of material already dispensed by the metering device during a metering operation and controlling a flow of material through the metering channel by moving the metering screw in an axial direction of the metering screw to define a width of a metering gap defining a gap between the metering slot Dosing and the termination of the dosing screw, wherein the width of the dosing is selected depending on the detected amount or the amount of material to be dosed yet.
    The metering device according to the invention comprises a metering channel, a metering screw, a measuring unit and a metering control. The metering screw is arranged in a metering channel. The metering screw has a transport section, which forms a helix, and has a closure region, which is set up to close the metering channel. The metering unit is configured to capture a quantity of material that has already been dispensed by the metering device during a metering operation, and the metering controller is configured to control a flow of material through the metering channel by moving the metering screw in an axial direction of the metering screw to set a width of a metering gap, which is a gap between the metering channel and the end portion of the metering screw, wherein the width of the metering gap is selected depending on the detected amount of material or the still to be metered amount.
    The metering device is in particular a laboratory machine. In particular, the metering channel is a channel which is arranged on a metering container in which the material to be metered is located. The metering channel is in particular a substantially cylindrical channel. The metering screw is arranged in the metering channel. In this case, a rotation axis of the metering screw lies on a central axis of the metering channel. An inner diameter of the metering channel corresponds to an outer diameter of the metering screw.
    The metering screw has a transport section. The transport section is in particular spiral-shaped or has the shape of a helix. A gear formed by a screw blade of the metering screw is called a screw flight. If the metering screw rotates in the metering channel, the material to be metered is transported through the screw flight.
    The metering screw has a termination region, the termination region connects in particular directly to the transport section of the metering screw. The closure region is in particular a plate-shaped region which extends over the entire inner diameter of the metering channel, so that it is located in the metering channel.
    There is a detection of an amount of material which has been discharged from the metering device during a dosing. Detecting the amount of material is measuring a quantity of material. In this case, the actual amount of material which was dispensed by the metering device during a metering process, detected by measurement. This is done in particular by weighing the material which has already been dispensed by the metering device during the metering process. The measuring unit used for this purpose is thus in particular a balance or a weighing cell.
    The metering controller is adapted to control a flow of material through the metering channel by moving the metering screw in an axial direction of the metering screw. The dosing control is in particular an electronic control unit. The metering gap is a gap between the metering channel and the end section of the metering screw. In this case, the worm gear of the transport section of the metering screw is located between one end of the metering channel and the end portion of the metering screw. If the metering screw is moved in the axial direction until the end region in the axial direction is at the same height as the metering channel, then the metering gap is closed. The dosing gap is thus a distance over which the transport section and thus the worm gear is not located in the dosing channel.
    It is thus achieved an improved metering and improved dosing accuracy. The dosing speed and achievable dosing accuracy are hitherto dependent on the screw geometry of the dosing screw and the speed with which the dosing screw is rotated in the case of a specific powder to be dosed. With a fine dosing screw, so a dosing with low depth and pitch gradient, very accurate dosing results can be achieved, but a large dosing requires a very long time for dosing. This can be compensated only limited by adjusting the speed of the metering screw. High speeds can also put heavy mechanical load on the powder and damage it. A coarse dosing screw, ie a dosing screw with high pitch and flight depth, enables fast but inaccurate dosing. Under certain circumstances, poorly flowing powders can not be dosed at all with fine dosing screws, and only very inaccurately with large screws. A fast but not exact dosage is not possible with many powders. Some powders require a minimum screw speed to achieve flow. Falls below this speed, a material flow comes to a halt. Such powders can not be precisely metered with the usual dosing screws and methods. These disadvantages are eliminated by the method according to the invention and the metering device according to the invention.
    By controlling the metering, so the material flow over the opening width of the screw at the outlet of the metering the material flow at a constant speed of the metering screw can be controlled. The opening width of the screw flight at the outlet of the metering channel corresponds to the metering gap. It is thus possible to achieve both a high metering speed with a large width of the metering gap and a high accuracy with minimum width of the metering gap. A maximum width of the metering gap is present when the metering gap corresponds to a complete helical flight height. With a minimum width of the dosing channel, the worm gear is almost completely covered. It is thus extended the usable mass flow range over a purely speed-controlled dosage. Thus, it is possible to regulate the metering rate at a constant speed of the metering screw, with a high number of revolutions being selected for poorly flowing, insensitive powders and a low rpm being selected for well-flowing sensitive powders. It can thus be a use of large dosing with poorly flowing powders and high achievable dosing accuracy. It can be achieved a quick dosing and at the same time a high dosing accuracy, especially when a large width of the dosing is selected until just before reaching a target value and the width of the dosing is reduced shortly before reaching the target amount. It can be done using a single screw geometry for most powders regardless of the dosage and the required dosing accuracy. It is therefore necessary only a small number of different screw geometries, which must be provided for different dosing operations. A suitably automated process makes it easier to find the optimum dosing parameters for each dosing process.
    The dependent claims show preferred developments of the invention.
    It is advantageous if the metering screw is operated at a constant speed, and the material flow is controlled by the metering channel by the metering screw is moved in the axial direction of the metering screw. The constant speed can be kept constant during the entire dosing or during a portion of the dosing process. The speed does not have to be regulated in this fold and can be optimally adapted to the material to be transported and a shape of the worm gear.
    Further, it is advantageous if the width of the dosing and / or a speed of the dosing screw is reduced continuously or stepwise to change from a coarse dosage to a fine dosage. The continuous or stepwise reduction of the width of the metering gap and / or the speed of the metering screw during a metering process takes place. A metering process is a process during which a quantity to be dispensed is dispensed by the metering device. This reduces the flow of material during the dosing process and prevents overdosing. At the same time, a maximum flow of material is ensured during the coarse dosing, whereby a quick dosing process is achieved.
    Also, it is advantageous if the speed of the metering screw is reduced in response to the fact that a predetermined amount of material was dispensed during the dosing. Thus, it can be achieved that a maximum metering speed is achieved, since the reduction of the speed is not reduced unnecessarily early, for example, if the material flow was interrupted for a short time.
    Furthermore, it is advantageous if the fine metering is carried out by a rotational movement of the metering screw with changing direction of rotation and / or a linear movement of the metering screw is performed with changing direction. In particular, the rotational movement of the metering screw with changing direction of rotation takes place at a constant width of the metering gap. Furthermore, it is advantageous if the linear movement of the metering screw is carried out with changing direction when the rotational movement of the metering screw is stopped or constant. In this way it can be achieved that very small amounts of the material to be dispensed are dispensed and a particularly accurate dosage can be achieved.
    It is also advantageous if the width of the dosing and / or a speed of the dosing screw is reduced continuously or gradually, when a predetermined time interval has elapsed since the beginning of dosing. In this way, a fine metering can be initiated, wherein the introduction of the fine metering is not affected by a possible overshoot of the measuring unit when measuring the already dispensed metering, which may result if a coarse metering is a particularly high flow of material.
    It is also advantageous if the metering screw is moved during the metering in changing directions along the axial direction of the metering screw, wherein the metering gap remains open for the flow of material. In simple terms, this means that the dosing screw is moved up and down during the dosing process. In this way, congestions of the flow of material in the flight can be prevented.
    It is also advantageous if the rotational speed of the metering screw is selected depending on a particle size of the material to be metered and / or a geometry of the metering screw. The method can thus be adapted particularly precisely to the material to be dosed.
    Further, it is advantageous if the end portion of the metering screw is shaped so that it is flush with the metering channel, if this is located within the metering channel. It can thus be prevented that the material deposits on a portion of the termination area, and falls away from this unintentionally, after a dosing should already be completed. It thus comes to a particularly accurate dosage.
    In general, a device which is suitable for carrying out the method according to the invention is advantageous. Such a device has all the advantages of the inventive method.
    BRIEF DESCRIPTION OF THE DRAWINGS Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings. In the drawing is:
    1 is a schematic representation of an inventive dosing device according to a first embodiment of the invention,
    2 is an illustration of an advantageous dosing screw,
    3 is an illustration of an advantageous dosing container,
    4 shows an illustration of a metering screw arranged in a metering channel for different widths of a metering gap, and FIG
    Fig. 5 is a diagram showing a speed of the metering screw and a width of the metering gap during a metering operation.
    EMBODIMENTS OF THE INVENTION FIG. 1 shows a metering device 1 according to a first embodiment of the invention. The metering device 1 is configured to carry out the method according to the invention for operating a metering device according to the first embodiment of the invention.
    The metering device 1 comprises a metering 2, a metering screw 3, a measuring unit 7 and a metering control 8. The metering 2 is a cylindrical channel, which is arranged at the bottom of a metering 9. With a correct arrangement of the metering device 1 according to the invention, a longitudinal axis of the metering channel 2 is arranged vertically. A material in the dosing container 9, for example a granulate or a powder, is thus moved by gravity in the direction of the dosing channel 2.
    The metering screw 3 is arranged in the metering channel 2. The metering screw 3 is shown in FIG. 2. The metering screw 3 is designed to rotate about an axis of rotation 11 of the metering screw 3 in order to convey the material through the metering channel 2. The metering screw 3 shown in Fig. 2 is shown so that the axis of rotation 11 of the metering screw 3 extends from left to right. Along the axis of rotation 11, the metering screw 3 essentially has three sections.
    In this case, a first section 10 is a fastening region. This fastening region makes it possible to clamp the metering screw 3 in the metering device 1. The attachment area is shown in Fig. 2 rightmost.
    The cylindrical part about the axis of rotation of the metering screw 3 is referred to as core. The space intended for conveying a bulk material is called aisle. The spiral material profile is called sheet. If the dosing screw 3 has no core and merely consists of a spirally curved profile, this is called a helix. With strong rounding between core and worm blade, so that the worm thread has a semicircular shape, one speaks of a concave worm, which is usually used in twin-screw arrangements. If a screw web angle 21 is equal to 0 °, then the screw is called a full leaf screw.
    At the attachment area joins along the axis of rotation 11 to a transport section 4, which forms a second portion of the metering screw 3. The transport section 4 forms a helix. In this advantageous embodiment, the transport section 4 is a spindle-shaped section. This means that it has a core in the center, which is circulated by a worm. In alternative embodiments, the core is dispensed with. In this case, the transport section 4 is a helix. If the metering screw 3 is located in the metering channel 2, then the spirally curved profile, which runs around the core, closes with the wall of the metering channel 2. The cavity which results between the metering channel 2 and the metering screw 3 is referred to as a screw flight. The material that spirals around the core is also called a worm blade.
    Along the axis of rotation 11 adjoins the transport section 4 to a termination region 5, which forms a third portion of the metering screw 3. The end region 5 is suitable for closing the metering channel 2. This is achieved in that the worm gear does not extend into the termination region 5. At the same time, the end region 5 is shaped such that it is in contact with the metering channel 2 on its full circumference when it is in the metering channel 2. A rotation amount of the transporting section 4 and the terminating area 5 are thus identical.
    With reference to Fig. 1 it can be seen that the metering screw 3 is connected via a coupling device 12 with a first motor 13. A rotational speed with the metering screw 3 is thus determined by the first motor 13 and a rotational speed of the metering screw 3 can be controlled by a rotational speed of the first motor 3.
    The dosing 9 is mounted on an arm 14 of the metering device 1 and is held by this. On the arm 14, a second motor 15 is arranged. The first motor 13 is coupled to the arm 14 via a mechanism and can be moved by an operation of the second motor 15 in an axial direction of the metering screw 3. In other words, this means that the first motor 13 can be moved up and down by the second motor 15. At the same time the dosing container 9 is held with the dosing channel 2 at a constant position relative to the arm 14. Since the metering screw 3 is coupled to the first motor 13, this is moved with the first motor 13 and thus moves in the axial direction in which the metering channel second
    The coupling device 12 comprises a spring-mounted bearing, by which the relative movement between the metering 9 and the metering screw 3 is compensated, so both the connection between the first motor 13 and the metering screw 3 is ensured, as well as a storage of the metering screw. 3 is ensured in the metering 9. The metering container 9 with the coupling device 12 is shown in Fig. 3 in a detailed view.
    The metering screw 3 is coupled via a shaft 17 to the first motor 13. The coupling device 12 comprises a bearing 19, in which the shaft 17 is rotatably mounted, but is not fixed in the axial direction. The shaft 17 is rigidly coupled to a rotor of the first motor 13. When the first motor 13 is moved by the second motor 15 in the axial direction of the metering screw 3, a spring 18 of the coupling device 12 is compressed or the spring 18 is expanded. Thus, the spring 18 is compressed when the first motor 13 and thus the shaft 17 is moved with the metering screw 3 down. The spring 18 expands when the first motor 13 and thus the shaft 17 with the metering screw 3 is moved upwards.
    Below the metering 2 and thus below the dosing 9 a target container 16 is arranged. In the target container 16, the material transported through the metering channel 2 is collected and thus collected the amount of material to be metered. The target container 16 is arranged on the measuring unit 7. The measuring unit 7 is adapted to detect a quantity of material which has already been dispensed by the metering device 1 during the dosing process. For this purpose, a weight of the target container 16 is measured, which increases as soon as the material falls into the target container 16 after it has been transported through the dosing channel 2.
    The dosing container 9 and the target container 16 are placed manually or by a handling system in a receptacle. During the dosing process, a drive unit comprising the first motor 13, a gearbox and a nut is lowered by a pneumatic lifting cylinder and thus coupled to the dosing container 9 to the first motor 13. The powder is conveyed out of the container by rotation of the metering screw 3 in the metering channel 2 and thereby falls into the target container 16 located underneath. The latter stands on the measuring unit 7, which enables the gravimetrically regulated metering. The system control can regulate the speed and thus the dosing speed directly during the dosing process by the continuous balance measured values of the measuring unit 7. As a result, high accuracies in the dosing result can be achieved. The dosing speed or the mass flow of the powder depends in addition to the speed v.A. from the screw geometry of the metering screw 3, in particular the pitch / depth and the slope from. The mass flow can therefore only be regulated to a limited extent by the rotational speed in a defined screw.
    The metering screw 3 is resiliently mounted in the axial direction. The end of the metering screw 3 or of the screw flight on which the powder emerges is not open but is closed off by a disk. The dosing screw 3 is pressed by the spring 18 when the dosing container 9 is coupled out, whereby the disc is flush with the outlet of the dosing channel 2 and closes it. An escape of the powder is thus prevented. For metering the metering screw is pressed against the spring force by a pneumatic axis against a mechanical stop down. The fully open screw or screw thread now protrudes from the outlet and it can be dosed. The metering properties correspond to those of a standard screw without a locking mechanism.
    The measuring unit 7, the first motor 13 and the second motor 15 are coupled to the dosing controller 8. The dosing controller 8 is an electronic control unit. By dosing control 8 a sequence of the inventive method is controlled. The dosing controller 8 includes a motor controller through which the first motor 13 and the second motor 14 are driven. Thus, a speed of the first motor 13 and thus a speed of the metering screw 3 can be controlled by the metering control 8. Furthermore, the second motor 15 can be actuated by the dosing control 8 and thus the dosing screw 3 can be moved in the axial direction with respect to the dosing channel 2. In addition, the metering controller 8 receives a measured value from the measuring unit 7 and thus records a quantity of material which has already been dispensed by the metering device 1 from the metering container 9 into the target container 16 during a metering process.
    If the dosing screw 3 is moved in an axial direction relative to the dosing channel 2 by the dosing control 8, a width of a dosing gap 6 is changed. The width of the metering gap 6 can thus be determined by the metering control 8. 4, the principle of the metering gap 6 is shown.
    Instead of a conventional pneumatic axis for coupling the metering drive to the metering 9 and to open the metering 9 by pressing out the disc-shaped closed metering screw 3 from the outlet opening of the metering 2, an exactly positionable axis, e.g. used electric servo axis. As a result, the metering container 9 can not only be completely closed or opened, but intermediate stages are also possible. That Due to the axial positionability of the metering screw 3 relative to the outlet of the metering channel 2, the metering gap 6 at the outlet of the metering channel 2 can be controlled in a controlled manner. By reducing the metering gap 6, the mass flow of the powder decreases at a constant speed, since the powder is braked by the constriction. That The powder accumulates in the dosing screw 3, but remains fluid.
    In Fig. 4 left, a state is shown in which the metering gap 6 has the width zero, so there is no metering 6. For this purpose, the metering screw 3 has been moved in the axial direction into a position opposite to the metering channel 2 in that the terminal region 5 of the metering screw 3 is located in the metering channel 2. Since the end region 5 is designed such that its outer circumference corresponds to an inner circumference of the metering channel 2, the end region 5 can be moved into the metering channel 2. The termination region 5 of the metering screw 3 thus terminates flush with the metering channel 2. Even if the metering screw 3 would rotate at the state shown in Fig. 4 leftmost state at a certain speed, so no material would be transported through the metering channel 2, since this is closed by the end portion 5 of the metering screw 3.
    In the state shown in Fig. 4 rightmost the width of the metering gap 6 is maximum. This is the case when the metering screw 3 has been moved so far in the axial direction relative to the metering channel 2, that the end portion 5 is so far away from one end of the metering channel 2nd that a full pitch 20 of the screw flight of the metering screw 3 protrudes from the metering channel 2. In this state, a maximum flow of material through the metering channel 2 can take place.
    In the state shown in FIG. 3 in the middle, the width of the metering gap 6 is not maximal, but the width of the metering gap 6 is also not equal to zero. Thus, although material can escape through the metering gap 6, however, the material flow is limited by the width of the metering gap 6. It can be seen that the width of the metering gap 6 can be changed by the movement of the metering screw 3 in the axial direction of the metering screw 3 with respect to the metering channel 2. This is done in the metering device shown in FIG. 1 by operating the second motor 15, which is controlled by the metering controller 8.
    A flow of a dosing operation is controlled by the dosing controller 8. The metering process is a process in which a certain amount of the material to be dispensed is discharged from the metering container 9 into the target container 16. A sequence of the dosing process is shown in the diagram shown in FIG. In this case, a first curve 110 describes the width of the metering gap 6 during the metering process. A second curve 120 describes the rotational speed of the metering screw 3 during the dosing process. Accordingly, a mass of the material is shown over an X-axis of the diagram 100, which was transported by the metering device 1 from the metering 9 in the target container 16. For the origin of the diagram shown in FIG. 5, the mass is equal to 0, that is, no material has yet been transported from the metering container 9 into the target container 16. Material is dispensed from the dosing container 9 into the target container 16 until a target value 104 is reached. In this case, the dosing process is completed. On the Y-axis of the diagram shown in FIG. 5, a width of the metering gap 6 is shown for the first curve 110 and the rotational speed of the metering screw 3 is shown for the second curve 120.
    The dosing process is divided into three phases. These three phases are composed of a first phase 101 at the beginning of the dosing process, a second phase 102, which adjoins the first phase 101, and a third phase 103, which is a final phase of the dosing process. In the first phase 101, a coarse dosage takes place. In the third phase 103, a fine dosing takes place.
    If a dosing operation is started, the coarse dosing is first carried out in the first phase 101. The metering screw 3 is operated at a constant speed, which is a maximum for the metering screw 3
    Speed for the material to be dispensed is to move as much material through the metering channel 2. So that no resistance for the material flow arises at the end of the metering channel, the width of the metering gap 6 in the first phase 101 is a maximum, ie equal to the height of a helical flight. Material is now transported from the metering container 9 into the target container 16. The weight of the target container 18 detected by the measuring unit 7 increases until a target value is reached. If this target value is reached, the second phase 102 of the metering process begins.
    In the second phase 102 of the metering process, the width of the metering gap 6 and the speed of the metering screw 3 is continuously reduced to change from the coarse dosage to the fine metering. This is illustrated in FIG. 5 in that the rotational speed of the metering screw continuously decreases from a higher value to a lower value. This applies correspondingly to the width of the metering gap 6. The second phase 102 continues until the rotational speed and the width of the metering gap 6 have dropped to a predetermined initial value of the third phase 103. Characterized in that the second phase 102 is initiated when it has been determined by the measuring unit 7 that a target value corresponding amount of material, ie a predetermined amount of material, has already been dispensed during the dosing, the speed of the dosing screw 3 in response reduced that a predetermined amount of material was dispensed during the dosing process.
    In an alternative embodiment of the invention, the second phase 102 is initiated after a predetermined time from the beginning of the dosing process. The width of the metering gap 6 and the speed of the metering screw 3 is continuously reduced in this case when a predetermined time interval has elapsed since the beginning of the metering operation.
    In the third phase 103, the fine metering takes place. In the dosing process shown in FIG. 5, the dosing screw 3 is operated at a constant speed, which is a significantly lower speed than that at which dosing screw 3 was operated in the first phase 101. In a corresponding manner, the width of the metering gap 6 in the third phase 103 is significantly smaller than the maximum width of the metering gap 6 from the first phase 101. During the fine metering in the third phase 103, the weight of the target container 16 is constantly monitored by the measuring unit 7 , As soon as a target value selected for the dosage, ie the target value 104, is reached, the rotational speed of the metering screw 3 is set to 0 and at the same time the width of the metering gap 6 is reduced to such an extent that the metering gap 6 has a width of 0, that is to say the metering channel 2 of FIG End region 5 of the metering screw 3 is closed. It is thus an after trickle of material in the target container 16 is prevented.
    It is advantageous if the target value 104, in which the rotation of the metering screw 3 is set, is chosen to be slightly lower than an amount of material actually to be metered. The remaining amount of material can be transported through the metering channel 2, that the metering screw 3 is moved only with changing direction in the metering channel 2. The dosing screw is controlled so that it moves slowly on average and material is metered. That the duration or distance of the forward movement is greater than the duration or distance of the backward movement. As a result, a trickling out of material from the metering channel 2 is achieved, whereby the smallest amounts reach the target container 16. It is thus achieved a particularly accurate dosage. In the same way it is possible to move the metering screw 3 at least partially open metering 6 with changing direction of rotation. In this way, a similar effect is achieved and there is a trickling of material from the metering gap 6, and it also very small amounts of material are moved into the target container 16.
    Optionally, it is possible that the metering screw 3 is moved in the first, the second or in the third phase 101, 102, 103 during the metering operation in an alternating direction along the axial direction of the metering screw 3, wherein the metering gap 6 for the Material flow remains open. Thus, an alternating movement of the metering screw 3 is carried out in the axial direction. This means that a width of the metering gap 6 is continuously changed in an alternating manner. Such a movement of the metering screw 3 avoids congestion in the screw flight.
    A control software of the metering device 1 is designed so that the powder mass flow can be controlled by both the speed of the metering drive and by the positioning of the metering screw through the vertical axis and the resulting adjustable metering 6. First, it is dosed with a high dosing speed and a fully opened dosing gap. That It is first metered with a high mass flow. From a certain distance to the target value 104 (e.g., controlled by scale), the speed and / or the metering gap are gradually or continuously reduced as the target value 104 approaches. Shortly before the target value 104 is metered at a continuous speed and low metering gap 6 (low mass flow) until the target value 104 is reached. After reaching the target value104, rotation of the metering screw 3 is stopped and the metering gap 2 is completely closed. The fine dosage can, for example, be refined by an oscillatory movement of the rotary movement (right - left) and / or the vertical movement (up - down).
    The switching points (distance to target value 104) for speed and metering gap 6 may be identical or different. That It can already be dosed at a constant fine dosing speed, while the dosing gap is continuously reduced. It is also possible to dose at a constant speed (adjustment of the dosing gap 6 only) or with a constant dosing gap 6 (adjustment of the speed only).
    In addition to the regulation of metering gap 6 and speed depending on the scale value, both can also be controlled time-controlled. For example, after a defined metering time, the metering gap 6 and the rotational speed of the metering screw 3 are changed or stopped or closed. The positionable vertical axis can also be used to move the metering screw 3 up and down during the dosing operation in order to improve after-flow of the powder, in particular in the case of poorly flowing powders.
    In addition to the above written disclosure, reference is explicitly made to the disclosure of FIGS. 1 to 5.
    权利要求:
    Claims (10)
    [1]
    claims
    1. A method for operating a metering device (1), which in a metering channel (2) arranged metering screw (3), which has a transport section (4) which forms a flight, and which has a termination region (5), which suitable to close the metering channel (2), comprising: - detecting an amount of material which has already been dispensed by the metering device (1) during a metering operation, and - controlling a material flow through the metering channel (2) by moving the metering screw (3) in an axial direction of the metering screw (3) to define a width of a metering gap (6) which is a gap between the metering channel (2) and the terminal portion (5) of the metering screw (3), the width of the metering gap (6) is selected depending on the detected amount of material.
    [2]
    2. The method according to claim 1, characterized in that the metering screw (3) is operated at a constant speed, and the material flow through the metering channel (2) is controlled by the metering screw (3) in the axial direction of the metering screw (3) is moved.
    [3]
    3. The method according to any one of the preceding claims, characterized in that the width of the metering gap (6) and / or a rotational speed of the metering screw (3) is reduced continuously or stepwise to change from a coarse dosage to a fine metering.
    [4]
    4. The method according to any one of the preceding claims, characterized in that a rotational speed of the metering screw (3) is reduced in response to a predetermined amount of material was dispensed during the metering process.
    [5]
    5. The method according to any one of the preceding claims, characterized in that a fine metering is carried out by a rotational movement of the metering screw (3) with changing direction of rotation and / or a linear movement of the metering screw (3) is performed with alternating direction.
    [6]
    6. The method according to any one of the preceding claims, characterized in that the width of the metering gap (6) and / or a rotational speed of the metering screw (3) is reduced continuously or stepwise when a predetermined time interval has elapsed since the beginning of the metering operation.
    [7]
    7. The method according to any one of the preceding claims, characterized in that the metering screw (3) is moved during the dosing in alternating directions along the axial direction of the metering screw, wherein the metering gap (6) remains open for the flow of material.
    [8]
    8. The method according to any one of the preceding claims, characterized in that a rotational speed of the metering screw (6) is selected depending on a particle size of the material to be metered and / or a geometry of the metering screw (3).
    [9]
    9. metering device (1), comprising a metering channel (2), a metering screw (3), a measuring unit (7) and a metering control (8), wherein - the metering screw (3) in the metering channel (2) is arranged, - Dosing screw (3), • a transport section (4), which forms a helix, and • a termination area (5), which is adapted to close the metering channel (2), - the measuring unit (7) is adapted to to detect an amount of material which has already been dispensed by the dosing device (1) during a dosing process, and - the dosing control (7) is adapted to control a material flow through the dosing channel (2) by the dosing screw (3) moved in an axial direction of the metering screw (3) to define a width of a metering gap (6), which is a gap between the metering channel (2) and the end portion (5) of the metering screw (3), wherein the width of the metering gap (6 ) ngig is selected from the detected amount of material.
    [10]
    10. Metering device according to claim 1, characterized in that the end region (5) of the metering screw is shaped such that it is flush with the metering channel (2) when it is within the metering channel (2).
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    同族专利:
    公开号 | 公开日
    DE102017207378A1|2018-11-08|
    CH713772B1|2022-02-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    2020-09-30| PUE| Assignment|Owner name: SYNTEGON TECHNOLOGY GMBH, DE Free format text: FORMER OWNER: ROBERT BOSCH GMBH, DE |
    2020-10-30| NV| New agent|Representative=s name: DREISS PATENTANWAELTE PARTG MBB, DE |
    2021-09-15| PK| Correction|Free format text: BERICHTIGUNG INHABER |
    优先权:
    申请号 | 申请日 | 专利标题
    DE102017207378.0A|DE102017207378A1|2017-05-03|2017-05-03|Metering device and method for operating a metering device|
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