WORKPIECE HOLDING DEVICE

Abstract

A workpiece holding device for holding a workpiece in a heat treatment system while the workpiece undergoes a thermal expansion and/or contraction includes at least two clamping units configured to apply a radial and/or an axial clamping force to the workpiece to hold the workpiece in the workpiece holding device in a predefined position, and at least three support units configured to support the workpiece. A first one of the at least three support units includes a first cylinder configured to support the workpiece, the first cylinder having a longitudinal axis and being configured to rotate around the longitudinal axis.

Claims

1. A workpiece holding device for holding a workpiece in a heat treatment system while the workpiece undergoes a thermal expansion and/or contraction, the workpiece holding device comprising: at least two clamping units configured to apply a radial and/or an axial clamping force to the workpiece to hold the workpiece in the workpiece holding device in a predefined position, and at least three support units configured to support the workpiece, wherein a first one of the at least three support units includes a first cylinder configured to support the workpiece, the first cylinder having a longitudinal axis and being configured to rotate around the longitudinal axis.

2. The workpiece holding device according to claim 1, wherein the workpiece is supported on the first cylinder such that rotating the first cylinder causes the workpiece to rotate in the workpiece holding device.

3. The workpiece holding device according to claim 2, wherein the first cylinder is a friction roller that frictionally engages the workpiece.

4. The workpiece holding device according to claim 3, wherein a weight of the workpiece determines a friction force between the friction roller and the workpiece.

5. The workpiece holding device according to claim 2, wherein the first cylinder includes a friction surfacing that increases a friction force between the first cylinder and the workpiece.

6. The workpiece holding device according to claim 2, wherein the longitudinal axis of the first cylinder is perpendicular to a rotational axis of the workpiece.

7. The workpiece holding device according to claim 1, wherein a second one of the at least three support units includes a second cylinder configured to support the workpiece, the second cylinder having a longitudinal axis and being configured to rotate around the longitudinal axis of the second cylinder, and wherein a third one of the at least three support units includes a third cylinder configured to support the workpiece, the third cylinder having a longitudinal axis and being configured to rotate around the longitudinal axis of the third cylinder.

8. Workpiece holding device according to claim 6, wherein the first cylinder is configured to be actively driven and the second and third cylinders are configured to be passively set in rotation by a rotation of the workpiece.

9. The workpiece holding device according to claim 8, including a first carrier supporting the first cylinder, a second carrier supporting the second cylinder and a third carrier supporting the third cylinder, wherein each of the first, second and third carriers extends radially away from a rotational centerpoint of the workpiece.

10. The workpiece holding device according to claim 9, wherein each of the at least two clamping units includes a clamping cylinder having an axis of rotation parallel to an axis of rotation of the workpiece, and wherein one of the at least two clamping cylinders is attached to each of the first, second and third carriers.

11. The workpiece holding device according to claim 10, wherein a radially inner end of each of the first, second and third carriers is pivotably supported such that the carrier is pivotable relative to the workpiece.

12. The workpiece holding device according to claim 10, wherein the first, second and third carriers are spaced from one another by an angle of approximately 120°.

13. A workpiece holding device according to claim 8, including: at least two carriers comprising: a first carrier supporting the first cylinder, a second carrier supporting the second cylinder, a third carrier supporting the third cylinder, a fourth carrier supporting a first one of the at least two clamping units, a fifth carrier supporting a second one of the at least two clamping units and a sixth carrier supporting a third one of the at least two clamping units.

14. The workpiece holding device according to claim 11, wherein the at least two carriers are equally angularly spaced.

15. A method comprising: providing a workpiece holding device according to claim 1, placing the workpiece onto the at least three support units of the workpiece holding device, applying a predetermined force to the workpiece with the at least two clamping units, rotating a first one of the at least three support units to rotate the workpiece in the workpiece holding device, performing a thermal treatment on at least a portion of the workpiece in the workpiece holding device, and while performing the thermal treatment, adjusting the at least two clamping units to maintain the predetermined clamping force.

16. A workpiece holding device for holding an annular workpiece in a heat treatment system while the workpiece undergoes a thermal expansion and/or contraction, the workpiece holding device comprising: a first rotatable support cylinder, a second rotatable support cylinder and a third rotatable support cylinder each having a cylindrical side surface configured to support the workpiece and each having a longitudinal axis of rotation lying in a plane and extending away from a center point, a first carrier supporting a first clamping cylinder, a second carrier supporting a second clamping cylinder and a third carrier supporting a third clamping cylinder, each of the first, second and third carriers having an end closest to the centerpoint that is pivotably supported such that pivoting the carrier moves a respective clamping cylinder toward the workpiece to clamp the workpiece with a predetermined force, wherein the first rotatable support cylinder is configured to be driven to rotate the workpiece relative to the workpiece holding device, and wherein the carriers are configured to pivot to maintain the predetermined force while the workpiece undergoes the thermal expansion or contraction.

17. The workpiece holding device according to claim 16, wherein the first rotatable support cylinder is mounted on the first carrier and the second rotatable cylinder is mounted on the second carrier and the third rotatable cylinder is mounted on the third carrier, and wherein the longitudinal axis of rotation of each of the rotatable support cylinders is perpendicular to an axis of rotation of each of the first, second and third clamping cylinders.

18. The workpiece holding device according to claim 16, including a fourth carrier supporting the first rotatable support cylinder, a fifth carrier supporting the second rotatable support cylinder and a sixth carrier supporting the third rotatable support cylinder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0067] FIG. 1 is a schematic depiction of an induction hardening system with a workpiece holding device according to a preferred exemplary embodiment of the present disclosure.

[0068] FIG. 2 is a schematic depiction of a workpiece holding device according to a further preferred exemplary of the present disclosure.

[0069] FIG. 3 is a schematic depiction of a clamping possibility of clamping units in the workpiece holding device according to FIG. 2.

[0070] FIG. 4 is a schematic depiction of a workpiece holding device according to a further preferred exemplary embodiment of the present disclosure.

[0071] FIG. 5 is a schematic depiction of a workpiece holding device according to a further preferred exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

[0072] In the following, identical or functionally equivalent elements are designated by the same reference numbers.

[0073] FIG. 1 schematically shows a plan view of an induction hardening system 100 that is designed to inductively harden a workpiece 2, e.g., a bearing ring, with the aid of an inductor 4. Here the induction hardening system 100 depicted in FIG. 1 is formed as a hardening system in which the inductor 4 always heats only one part of the workpiece 2 while the workpiece 2 is moved past the inductor 4. For this purpose the workpiece 2 is clamped into a main body portion 5 of a workpiece holding device 6 and moved past the inductor 4. For the receiving of the workpiece 2, the workpiece holding device 6 includes clamping units 8-1, 8-2, 8-3 that are designed to hold the workpiece 2.

[0074] Furthermore, FIG. 1 shows that in the exemplary embodiments depicted, the workpiece 2 lies against three support units 12-1, 12-2, 12-3.

[0075] Now instead of, as in the prior art, rotating the entire system 6 in order to move the workpiece 2 past the inductor 4, a drive unit 14 is now furthermore provided that is designed to rotate only the workpiece 2. Of course, more than one drive unit 14 can also be present.

[0076] Here the drive unit 14 can be, for example, a friction wheel or a friction roller that acts directly onto the workpiece 2 and sets it in rotation. Instead of a separate drive device 14 as depicted in FIG. 1, one of the clamping units 8 and/or of the support units 12 can also be configured as a drive unit 14. Thus, for example, the clamping unit 8-1 can be configured simultaneously as a friction wheel or a friction roller that in turn acts directly on the workpiece 2 and sets it in rotation.

[0077] The clamping units 8, the support units 12, and/or the drive unit 14 can be moved radially, axially, circumferentially and/or tangentially in order to optimally abut against the workpiece 2. Furthermore, on one or more of the units 8, 12, 14 it is possible to attach one or more measuring devices 13 that are designed to measure a contact force and/or clamping force and/or friction force between the clamping units 8 and/or the support units 12 and/or the drive unit 14 and the workpiece 2. Furthermore, a controller 15 can also be provided that interacts with the units 8, 12 and 14 such that the units 8, 12, 14 interact with the workpiece 2 with a predetermined contact force, clamping force, and/or friction force.

[0078] FIG. 2 shows a schematic-perspective view of a first preferred embodiment of a workpiece holding device 6 that can be used in an induction hardening system 100 as schematically depicted in FIG. 1. In the exemplary embodiment depicted, the workpiece holding device 6 comprises four carriers 60-1, 60-2, 60-3, 60-4 that each carry rod-shaped, in particular cylindrical, shafts 62-1, 62-2, 62-3, 62-4. Here the carriers 60 and the shafts 62 can also be configured as one-piece integral elements. The shafts 62 and the carriers 60 in turn are rotatably attached to bearing assemblies 64 so that the carriers 60 extend radially outward from a rotational center M, wherein the rotational center M is determined by the rotation of the workpiece 2 in the workpiece holding device 6.

[0079] Furthermore, it can be seen from FIG. 2 that in the region wherein the workpiece 2 rests on the carriers 60, cylindrical contact elements 16-1, 16-2, 16-3, 16-4 are provided that are rotatably disposed on the carriers 60. Due to the rotatability of the cylindrical contact elements 16-1, 16-2, 16-3, 16-4, the workpiece 2 can easily be set in rotation. For this purpose, one of the rotatable cylinders 16 can be actively driven, that is, set in rotation, whereby the workpiece 2 is set in motion due to the friction between the cylinder 16 and the workpiece 2.

[0080] Of course, more cylinders 16, or all cylinders 16, can also be actively driven.

[0081] Furthermore, FIG. 2 shows that on the carriers 60, and in particular on the shafts 62, clamping units 8-1, 8-2, 8-3, 8-4 are provided in the form of clamping elements 10-1, 10-2, 10-3, 10-4, that are designed to secure the workpiece 2 in its position. For this purpose, the clamping devices 8 can be set, for example, radially against the carriers 60 or against the shaft 62 until they contact the workpiece 2 and secure it in its position.

[0082] As depicted in FIG. 2, the clamping units 8 include clamping cylinders 10. The clamping cylinders 10 can be designed as sleeves and be releasably, and preferably rotatably, slipped onto hubs 63. Here it is advantageous in particular when the clamping cylinder 10, together with its hub 63, is radially displaceable along the carrier 60 or the shaft 62 in order to be adapted to different workpieces 2 or in order to, for example, exert a clamping force on a radially inner surface 24 of the workpiece 2 instead of the clamping force depicted here on a radially outer surface 22 of the workpiece 2.

[0083] Alternatively or additionally, one of the clamping units, for example, 8-3, can function as a drive unit 14 and then instead of a clamping cylinder 10-3 carries a friction roller 18 that frictionally abuts against the workpiece 2 and is actively set in rotation in order to rotate the workpiece 2. The driven clamping roller/friction roller 18 can be present alternatively or in addition to a driven cylinder 16.

[0084] In addition to the radial adjustability of the clamping units 8, in addition it can also be provided that the carriers 60 are themselves movable and can be brought from an open position in which the workpiece 2 can be placed in the workpiece holding device 6 and against the cylindrical rollers 16, into a closed position in which the workpiece is clamped in the clamping units 8 and they abut against the workpiece 2 with clamping force. For this purpose the carriers 60 are rotatably supported on carrier bearing assemblies 64-1, 64-2, 64-3, 64-4. The carrier bearing assemblies 64 are in turn disposed eccentrically with respect to the rotational center M of the workpiece.

[0085] FIG. 3 schematically shows the design from FIG. 2, and the clamping possibility corresponds to that in the exemplary embodiment depicted in FIG. 2. Since, as mentioned above, the carriers 60 are not supported in the rotational center M but rather are eccentrically supported at points 64-1, 64-2, 64-3 and 64-4, the distance between the clamping elements 8 and the workpiece 2 can be maximized or minimized depending on the position of the carriers. Thus, for example, in a so-called zero position, the distance between clamping unit 8 and the workpiece 2 can be maximized so that the workpiece 2 can be inserted into the workpiece holding device 6 without it contacting the clamping unit. In the exemplary embodiment depicted, this is possible with an orientation of the carriers in the radius direction of the workpiece. That is, when the carrier is oriented precisely in the radius direction R of the workpiece 2 (see FIG. 3), the distance between workpiece 2 and clamping unit 8 is maximized. With an angular adjustment about the zero position (see arrow), the clamping unit 8 approaches the workpiece 2 until the clamping unit 8 abuts against the workpiece 2 and can exert a clamping force. This applies to the design shown in FIGS. 2 or 3, in which a radially inwardly directed clamping force is applied, and the clamping units 8 are disposed radially outside on the workpiece 2.

[0086] In contrast, if the workpiece is clamped with a radially outwardly directed clamping force, i.e., with a clamping of the workpiece with clamping units disposed radially inside the workpiece, the clamping is increased when the carrier is rotated toward the orientation in the radius direction. In this case, a zero position is given over a certain maximum angular displacement, in particular at 45°, of the carrier with respect to the radius orientation.

[0087] FIG. 4 shows another preferred exemplary embodiment in which the support units 12 and the clamping units 8 are attached on separate carriers 62 or 60. Here the workpiece 2 again abuts against rotatably supported cylinders 16-1, 16-2, 16-3. In addition, FIG. 4 shows that three support units 12 or 3 clamping units 8 are provided. The drive unit 14 can in turn be integrated into the cylindrical elements 16 or into the clamping units 8 in order to set the workpiece 2 in rotation.

[0088] The clamping units 8 can in turn also include clamping cylinders 10-1, 10-2 and 10-3 that can be moved radially in order to exert a clamping on the workpiece 2 and to hold it in position.

[0089] Here too, the rotatable cylinders 16 provide for a low-friction and tilt-free supporting of the workpiece 2 and simultaneously for a particularly good accessibility to the surfaces to be treated.

[0090] FIG. 5 shows a further preferred exemplary embodiment in which the rotatable cylinder 16 and a clamping unit 8 formed as friction wheel 18 are present as a combined element. Here the friction wheel 18 abuts against the radial outer surface 22 of the workpiece and can thus simultaneously exert a clamping force on the workpiece 2. Thus the friction wheel 18 also assumes the function of the clamping unit 8. During rotation of the cylinder 16 about its longitudinal axis A, the friction wheel 18 is simultaneously rotated. Due to the abutment (friction) of the friction wheel 18 against the outer surface 22 of the workpiece, the rotational movement of the cylinder 16 is also transmitted via the friction wheel 18 onto the workpiece 2 so that the workpiece 2 is also rotated.

[0091] In summary, with the presented workpiece holding device it can be achieved that a particularly good contact and accessibility of the workpiece can be achieved in the workpiece holding device, wherein the workpiece is simultaneously easily movable via the support unit. In addition, a clamping of the clamping elements can also be made possible without additional elements. This is achieved via the eccentric supporting of carriers that can bring the clamping units closer to or farther away from their contact surface on the workpiece.

[0092] As used herein, a controller can be a programmable hardware component which can be formed by a processor, a computer processor (CPU = central processing unit), an application-specific integrated circuit (ASIC), an integrated circuit (IC), a computer, a system-on-a-chip (SOC), a programmable logic element, or a field programmable gate array (FGPA) including a microprocessor.

[0093] Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved workpiece holding devices.

[0094] Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

[0095] All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.

REFERENCE NUMBER LIST

[0096] TABLE-US-00001 100 Hardening system 2 Workpiece 4 Induction coil 5 Main body portion 6 Workpiece holding device 8 Clamping unit 10 Clamping element 12 Support unit 13 Measuring device 14 Drive unit 15 Controller 16 Cylindrical contact element 18 Friction roller 22 Radially outer side of the workpiece 24 Radially inner side of the workpiece 60 Carrier 62 Rod-shaped shaft 63 Hub 64 Bearing assembly