• 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 invention relates to a Dehnspannhülse for a Dehnspannfutter, having a first and a second bearing portion, a clamping portion which can engage a tool shaft, and a thrust portion which is arranged between the clamping portion and the first bearing portion. The invention further relates to a tool holder with such a Dehnspannhülse, wherein a contact surface is provided for a tool-side stop. Finally, the invention relates to a method for clamping a tool by means of a Dehnspannfutters, in which a shaft of the tool is inserted into the Dehnspannfutter in a first step, then the Dehnspannfutter is pressurized, so that a clamping portion of the Dehnspannfutters spans the tool shank in the radial direction and a thrust portion of the expansion chuck moves the tool shank in the axial direction, so that a tool-side stop against a contact surface of a tool holder with an axial minimum clamping force is applied.
    公开号:AT519493A2
    申请号:T51002/2017
    申请日:2017-12-05
    公开日:2018-07-15
    发明作者:
    申请人:Kennametal Inc；
    IPC主号:
    专利说明:

    Expansion sleeve, tool holder with such expansion sleeve and method for clamping a tool
    The invention relates to a Dehnspannhülse for a Dehnspannfutter, with a first and a second bearing portion and a clamping portion which can engage a tool shank. The invention further relates to a tool holder with such a Dehnspannhülse and a method for clamping a tool.
    Dehnspannfutter for machine tools are well known in the art. They serve to clamp a tool in a tool holder. In general terms, they have a pressure chamber which can be acted upon by a medium under high pressure (usually hydraulic oil), so that the expansion clamping sleeve is elastically deformed. Thereby it engages a shank of the tool, which is inserted into the expansion sleeve. This results in a frictional connection between the tool shank and the expansion sleeve.
    In addition, mechanical locking means may be used to lock the tool shank in a particular position and / or to increase the transmittable torque.
    The advantage of hydraulic expansion chucks lies in the fact that the tools can be clamped reliably with little effort. The disadvantage, however, is that the rigidity with which the tools are received in the chuck is not optimal for all applications. Furthermore, in order to increase the rigidity, the expansion chucks must have comparatively large dimensions. Therefore, for some applications, for example, the machining of valve seats, tool holders are used which are based on the engagement of two conical surfaces.
    The object of the invention is to provide a Dehnspannfutter, which has small dimensions and makes it possible to clamp a tool with high rigidity.
    To solve this problem, a thrust portion is provided with a Dehnspannfutter of the type mentioned, which is arranged between the clamping portion and the first bearing portion. The object is also achieved by a tool holder with such a Dehnspannhülse, wherein a contact surface is provided for a tool-side stop. Finally, the above object is achieved by a method for clamping a tool by means of a Dehnspannfutters, in which a shaft of the tool is inserted into the Dehnspannfutter in a first step, then the Dehnspannfutter is pressurized, so that a clamping portion of the Dehnspannfutters the tool shank in Spans radial direction and a thrust portion of the Dehnspannfutters the clamping section and thus the tool shank in the axial direction shifts, so that a tool-side stop against a contact surface of a tool holder is acted upon.
    The invention is based on the idea of converting the pressure acting in the pressure chamber of the expansion chuck into two different deformations of the expansion sleeve: a radial deformation of the clamping section, by means of which the tool shank is clamped, and an axial displacement of the clamping section, caused by a deformation of the pushing section. Due to the axial displacement of the clamping section of the tool shank and thus the tool is displaced in the axial direction as a whole, so that it can be clamped against a tool-side abutment surface. The tool-side abutment surface can serve to increase the transmittable between the tool holder and the tool torque. In particular, the tool-side contact surface but serves to increase the rigidity with which the tool is clamped in the tool holder.
    The thrust portion may, viewed in a cross section, have at least one leg extending obliquely to the central axis of the tensioning portion. With such a geometry, a radial deformation of the leg can be converted with very little effort into an axial displacement of the clamping section.
    Preferably, the push portion has two legs which merge into one another and preferably in opposite directions obliquely to
    Center axis of the clamping section extend. The two legs together form a bulge, so that a free annular space is formed on the inside of the legs around the tool shank around. When a pressure is applied from the outside, the two legs act much like a toggle mechanism, which acts on the clamping portion of the first bearing portion away.
    Between the two legs, a relief groove can be provided on the inside to reduce a notch effect at this point. In addition to reducing the notch effect, the relief groove can also be used to adjust the rigidity of the push section. For the optimum clamping effect, care must be taken that the clamping section in the tool shank first tensions in the radial direction before the thrust section adjusts the clamping section in the axial direction.
    It is preferably provided that the thrust section adjoins the first bearing section. This can in turn be supported on an abutment in the tool holder body in the axial direction. In this design, the reaction forces resulting during the axial displacement of the clamping section can be supported directly in the tool holder body without detour.
    A relief groove may also be provided adjacent to the push section. If the thrust section has two legs, corresponding relief grooves can be provided on the two sides of the thrust section. These serve as well as the relief groove provided on the inside to avoid notch stresses. In addition, the dimensions of the relief groove can influence the tensioning force at which the thrust section generates the desired axial displacement.
    It is preferably provided that the second bearing section is arranged axially outside of the clamping section. This is advantageous if the second bearing section is fixed in the axial direction in the tool holder body. This geometry facilitates the tensioning portion to shift away from the first bearing portion.
    Preferably, it can be provided in this case that between the second bearing portion and the clamping portion is a substantially radially
    Direction extending, annular spring portion is arranged. The spring portion serves to rigidly support the clamping portion in the radial direction, while allowing the desired axial displacement. According to a preferred embodiment, it is provided that the second bearing section has a collar facing the first bearing section. The advantage of this design is that a defined area for pressure-tight connection of the expansion clamping sleeve is defined with the tool holder body. For example, the expansion sleeve can be soldered to the tool holder body.
    The contact surface provided on the tool holder is preferably a cone. With this, an automatic centering of the tool can be achieved when it is acted upon by means of the clamping portion against the contact surface. In addition, the maximum transmissible torque can be increased particularly strong by the wedge effect of a cone.
    Preferably, the second bearing portion is received by means of its peripheral surface fixed in the tool holder body. This increases the rigidity with which the tool is received in the tool holder in the radial direction.
    The Dehnspannhülse can in principle be used directly in the tool holder body and there are tightly connected to this, so that between the Dehnspannhülse and the tool holder body, the pressure chamber is formed. Alternatively, it is also possible to arrange a sealing sleeve around the expansion chuck, so that a self-contained expansion chuck is formed, which can be used in the manner of a cartridge in a tool holder body.
    Advantageous embodiments of the invention will become apparent from the dependent claims.
    The invention will be described below with reference to an embodiment shown in the accompanying drawings. In this show:
    Figure 1 shows schematically a tool holder according to the invention with tool received therein;
    FIG. 2 shows an enlarged view of the expansion clamping sleeve accommodated in the tool holder of FIG. 1;
    Figure 3 is a sectional view of a Dehnspannhülse with it received tool shank before clamping; and Figure 4 is a view corresponding to that of Figure 3 of the expansion sleeve and tool shank after tightening.
    FIG. 1 shows in a section a tool holder 1 which has a tool holder body 2. A receiving opening 9, into which a shaft 3 of a tool 4 schematically indicated here extends, extends centrally through the tool holder.
    The tool may be, for example, a drill or a milling cutter. In principle, any machining tool can be used, which should be precisely clamped so that high torsional and bending moments can be transmitted.
    On the tool 4, a stop 5 is provided, which is designed here as an outer cone. The stop 5 is located when the tool 4 is clamped in the tool holder 1, on a contact surface 7, which is provided on the tool holder body. The contact surface is designed here as an inner cone. The cone angle of the contact surface 7 and the stop 5 are in the order of 3 to 45 °. Alternatively, the stop can also be designed as an axial face machine, as a tapered face machine or as a cylindrical face machine.
    The tool 1 is designed here as a stretch chuck. For this purpose, a Dehnspannhülse 10 is arranged in the tool holder body 2, which defines a pressure chamber 12 between itself and the tool holder body 2. This can be pressurized in a manner which is basically known by means of a medium (for example hydraulic oil) so that the tool shank 3 is tensioned in the radial direction within the expansion clamping sleeve.
    The structure of the expansion sleeve 10 is described below with reference to Figure 2 from left to right, so starting on the outside to the interior of the tool holder back.
    The expansion sleeve 10 has a first bearing portion 14 which lies in a receiving shoulder 15 in the tool holder body 2. The first bearing section 14 serves in the axial direction as a boundary of the pressure chamber 12.
    The bearing portion 14 is a circular ring, which is arranged concentrically to the central axis M. This also applies to the sections of the expansion sleeve 10 described below, which also extend like a sleeve along the central axis M and concentric therewith.
    The first bearing section 14 is adjoined by a thrust section 16, which is formed by two legs 18, 20 oriented obliquely to the central axis M. Starting from the first bearing section 14, the first leg 18 extends obliquely outwards, while the second leg extends obliquely inwards stretches.
    The angle of the legs 18, 20 relative to the central axis is of the order of 3 to 45 °.
    At the end remote from the first bearing portion 14 end of the thrust portion 16, a clamping portion 22 connects, which is filled as a sleeve with a substantially constant inner diameter. The inner diameter of the clamping portion 22 and the first bearing portion 14 substantially defines the diameter of the receiving opening 9, which extends through the tool holder body 2.
    At the end remote from the first bearing portion of the clamping portion 22, a spring portion 24 connects, which extends substantially in the radial direction to the outside. In practice, the spring portion may be made slightly conical, similar to a plate spring.
    At the outer periphery of the annular spring portion 24, a second bearing portion 26 connects. The bearing portion 26 has a peripheral surface, with which it rests in the radial direction on the outer circumference of a support groove 28, and a collar 30, which faces the first bearing portion 14 in the embodiment shown and bears against the bottom of the receiving groove.
    The contact of the collar 30 with the bottom of the receiving groove 28 limits the pressure chamber 12 on the side facing away from the first bearing portion 14 side.
    The expansion sleeve 10 is tightly connected to the tool holder body 2 in the region of the first bearing portion 14 and the second bearing portion 28. In particular, the Dehnspannhülse be soldered.
    At the transition between the first bearing portion 14 and the first leg 18, at the transition between the two legs 18, 20, at the transition between the second leg 20 and the clamping portion 22 and at the transition from the spring portion 24 to the bearing portion 26 relief grooves 38 may be provided.
    The pressure chamber 12 can be pressurized via a supply bore 40 indicated in FIG. As a result, the clamping section 22 is compressed, so that it is tensioned in the radial direction against the tool shaft 3.
    When the pressure in the pressure chamber 12 is further increased, the legs 18, 20 are pressed inwardly to the central axis M. As a result, the clamping section 22 is pushed away from the first bearing section 14, so that the tool shaft 3 clamped in the clamping section 22 is also displaced in the axial direction (see the arrow P in FIG. 4). By comparing Figures 3 and 4, this effect is clearly visible.
    FIG. 3 shows the initial state in which the thrust section 16 extends outward around the tool shank 3 and bulges outwards.
    In Figure 4 it can be seen that the thrust portion 16 has been compressed in the radial direction, whereby the clamping portion 22 has been moved in the axial direction (relative to Figure 4) to the right. This can be seen in particular from the fact that the spring portion 24 has also been displaced to the right at its radially inner circumference.
    Due to the axial movement of the tool shank received in the clamping section, the stop 5 of the tool shank 3 becomes fixed in the
    Bearing surface 7 of the tool holder 1 is pulled, so that the tool 4 is fixed there precisely and with high rigidity.
    The resulting during clamping deformation of the expansion sleeve 10 is shown greatly exaggerated in Figure 4 for clarity. The axial stroke of the radially inner end of the spring portion 24 is in practice of the order of 10 to 100 micrometers.
    权利要求:
    Claims (18)
    [1]
    claims
    A stretch chuck (10) for a chuck having a first and a second bearing portion (14, 26) and a chuck portion (22) engageable with a tool shank (3), characterized by a push portion (16) extending between Clamping portion (22) and the first bearing portion (14) is arranged.
    [2]
    2. Dehnspannhülse (10) according to claim 1, characterized in that the thrust portion (16), viewed in a cross section, at least one obliquely to the central axis (M) of the clamping portion (22) extending legs (18, 20).
    [3]
    3. Dehnspannhülse (10) according to claim 2, characterized in that a plurality of obliquely arranged legs (18, 20) are provided.
    [4]
    4. Dehnspannhülse (10) according to claim 2 or claim 3, characterized in that the thrust portion has two legs (18, 20) which merge into one another and extend in opposite directions obliquely to the central axis (M) of the clamping portion (22).
    [5]
    5. Dehnspannhülse (10) according to claim 4, characterized in that the two legs (18, 20) define a bulge of the expansion sleeve.
    [6]
    6. Dehnspannhülse (10) according to claim 4 or claim 5, characterized in that between the two legs (18, 20) on the inside a relief groove (38) is provided.
    [7]
    7. Dehnspannhülse (10) according to any one of the preceding claims, characterized in that the thrust portion (16) adjacent to the first bearing portion (14).
    [8]
    8. Dehnspannhülse (10) according to any one of the preceding claims, characterized in that adjacent to the thrust portion (16) a relief groove (38).
    [9]
    9. Dehnspannhülse (10) according to any one of the preceding claims, characterized in that the second bearing portion (26) is arranged radially outside of the clamping portion (22).
    [10]
    10. Dehnspannhülse (10) according to claim 9, characterized in that between the second bearing portion (26) and the clamping portion (22) extending substantially in the radial direction, annular spring portion (24) is arranged.
    [11]
    11. Dehnspannhülse (10) according to any one of the preceding claims, characterized in that the second bearing portion (26) has a first bearing portion (14) facing collar (30).
    [12]
    12. Dehnspannfutter with a Dehnspannhülse according to one of the preceding claims, wherein radially outside the clamping portion and the thrust portion a sealing sleeve is arranged, so that a pressure chamber is delimited between the Dehnspannhülse and the sealing sleeve.
    [13]
    13. Tool holder (1) with a Dehnspannhülse (10) according to one of claims 1 to 10, characterized in that a contact surface (7) for a tool-side stop (5) is provided.
    [14]
    14. Tool holder (1) according to claim 13, characterized in that the expansion clamping sleeve (10) is received in a tool holder body (2) and the abutment surface (7) on the tool holder body (2) is arranged.
    [15]
    15. Tool holder according to claim 14, characterized in that the abutment surface (7) is a cone.
    [16]
    16. Tool holder according to one of claims 13 to 15, characterized in that the first bearing portion (14) on an abutment (15) in the tool holder body (2) bears axially.
    [17]
    17. Tool holder according to one of claims 13 to 16 in combination with claim 10, characterized in that the second bearing portion (26) by means of its peripheral surface fixedly received in the tool holder body (2).
    [18]
    18. A method for clamping a tool (4) by means of a Dehnspannfutters, wherein in a first step, a shaft (3) of the tool (4) is inserted into the Dehnspannfutter, then the Dehnspannfutter is pressurized, so that a clamping portion (22 ) of the expansion chuck clamps the tool shank (3) in the radial direction and a thrust section (16) of the expansion chuck displaces the clamping section (22) and thus the tool shank (3) in the axial direction, so that a tool-side abutment (5) against a contact surface (7 ) of a tool holder (1) is applied, whereby an axial bias is generated.
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    同族专利:
    公开号 | 公开日
    AT519493A3|2018-08-15|
    DE102016123728A1|2018-06-07|
    HU1700510A2|2018-06-28|
    CN108161044A|2018-06-15|
    US20180154454A1|2018-06-07|
    MX2017015262A|2018-11-09|
    FR3059579A1|2018-06-08|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US3171666A|1962-12-14|1965-03-02|Erickson Tool Co|Positive drive chuck|
    FR96256E|1966-01-05|1972-06-16|Anciens Etablissements T M B|Fluid chuck.|
    DE1625452C3|1967-12-15|1974-05-02|Rudolf 7300 Esslingen Spieth|Device for releasably connecting two connecting bodies, in particular a disk with a shaft|
    US3663027A|1970-09-14|1972-05-16|Ingersoll Milling Machine Co|Fluid actuated clamp|
    GB2074907B|1980-05-02|1983-12-07|Foster Miller Ass|Drill shaft gripping mechanism|
    DE4317170C2|1993-05-22|2000-11-30|Schunk Fritz Gmbh|Expansion tools for clamping workpieces, tools or other components with a flat contact surface on the front|
    US7059457B2|2003-10-06|2006-06-13|Lee Lanny R|Expansion motor|
    DE202006017331U1|2005-11-18|2007-02-08|Günther & Co. GmbH|Cutting tool used in automatic boring and rivet machine for cutting workpiece, has cylindrical shank with cone part that has lateral surface formed with conical sections for receiving mounting spindle or chuck|
    AT14084U1|2013-10-16|2015-04-15|Ceratizit Austria Gmbh|Machining tool and method for producing a machining tool|DE102018221005A1|2018-12-05|2020-06-10|Audi Ag|Chuck for a rotary tool|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    DE102016123728.0A|DE102016123728A1|2016-12-07|2016-12-07|Expansion sleeve, tool holder with such expansion sleeve and method for clamping a tool|
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