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 an adjustment mechanism for setting the at least two clamping units to synchronously apply a substantially identical radial and/or axial clamping force to the workpiece.

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 adjusting means for setting the at least two clamping units to synchronously apply a substantially identical radial and/or axial clamping force to the workpiece.

2. The workpiece holding device according to claim 1, wherein the adjusting means comprises a plurality of adjusting units, and wherein a first one of the plurality of adjusting units is directly driven and all other ones of the plurality of adjusting units are driven by the first one of the adjusting units.

3. The workpiece holding device according to claim 2, wherein the adjusting means includes a belt, a chain or a gear that mechanically couples the at least two clamping units.

4. The workpiece holding device according to claim 3, wherein the at least two clamping units comprises exactly three clamping units or exactly four clamping units.

5. The workpiece holding device according to claim 3, wherein the at least one clamping unit includes at least one clamping cylinder that is preloaded against the workpiece with a predetermined abutment force, and wherein clamping element is furthermore configured to move to maintain the predetermined abutment force during the thermal expansion and/or contraction of the workpiece.

6. The workpiece holding device according to claim 5, wherein the at least one clamping cylinder is rotatable about an axis parallel to a rotational axis of the workpiece.

7. The workpiece holding device according to claim 6, including a drivable friction wheel or a drivable friction roller configured to frictionally engage the workpiece to rotate the workpiece.

8. The workpiece holding device according to claim 7, wherein a contact force between the drivable friction wheel and the workpiece or the drivable friction roller and the workpiece is adjustable.

9. The workpiece holding device according to claim 6, wherein a first one of the at least one of the clamping cylinder is actively rotationally driven.

10. The workpiece holding device according to claim 5, including a controller configured to control the clamping force.

11. The workpiece holding device according to claim 5, a force sensor configured to measure the clamping force and to send a signal indicative of the clamping force to the controller.

12. The workpiece holding device according to claim 11, including at least three support rotatable support cylinders configured to support the workpiece.

13. A method comprising: providing a workpiece holding device according to claim 1, inserting the workpiece in the workpiece holding device, using the adjusting means to synchronously clamp the at least two clamping units against the workpiece with a predetermined and equal clamping force, rotating the workpiece relative to 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.

14. The workpiece holding device according to claim 1, wherein the at least two clamping units each includes a rotatable disk, and wherein the adjusting means comprises a chain or belt operatively connected to each rotatable disk to cause the rotatable disks to rotate simultaneously.

15. The workpiece holding device according to claim 1, wherein the at least two clamping units each includes a rotatable disk, and wherein the adjusting means comprises a gear operatively connected to each rotatable disk to cause the rotatable disks to rotate simultaneously.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] FIG. 1 is a schematic depiction of an induction hardening system including a workpiece holding device according to a preferred exemplary embodiment of the present disclosure.

[0060] FIGS. 2a and 2b are schematic depictions of a first preferred exemplary embodiment of a workpiece holding device with a synchronous clamping unit according to the present disclosure.

[0061] FIG. 3 is a schematic depiction of a further preferred exemplary embodiment of a workpiece holding device with a synchronous clamping unit according to the present disclosure.

[0062] FIG. 4 is a schematic depiction of a further preferred exemplary embodiment of a workpiece holding device with a synchronous clamping unit according to the present disclosure.

[0063] FIG. 5 is a schematic depiction of a further preferred exemplary embodiment of a workpiece holding device with a synchronous clamping unit according to the present disclosure.

[0064] FIG. 6 is a schematic depiction of a further preferred exemplary embodiment of a workpiece holding device with a synchronous clamping unit according to the present disclosure.

[0065] FIG. 7 is a schematic depiction of a further preferred exemplary embodiment of a workpiece holding device with a synchronous clamping unit according to the present disclosure.

[0066] FIG. 8 is a schematic depiction of a further preferred exemplary embodiment of a workpiece holding device with a synchronous clamping unit according to the present disclosure.

DETAILED DESCRIPTION

[0067] In the following, identical or functionally equivalent elements are designated by the same reference numbers.

[0068] 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 this purpose, the workpiece holding device 6 has clamping units 8-1, 8-2, 8-3 for holding the workpiece 2, which are designed to hold the workpiece 2.

[0069] Furthermore, FIG. 1 shows that in the exemplary embodiments depicted, the workpiece 2 is supported by three support units 12-1, 12-2, 12-3.

[0070] Now instead of, as in the prior art, rotating the entire system 6 in order to move the workpiece 2 along 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.

[0071] Here the drive unit 14 can be, for example, a friction wheel or a friction roller that acts directly on 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.

[0072] The clamping units 8, the support units 12, and/or the drive unit 14 can be moved radially, axially, and/or tangentially in order to optimally abut against the workpiece 2. Furthermore, it is possible to attach one or more measuring devices 13 on one or more of the units 8, 12, 14 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.

[0073] As the following exemplary embodiments of FIGS. 2 to 8 show, the clamping units 8 themselves are synchronously clamped with the aid of an adjusting device 20 in order to apply a substantially equal radial, axial, and/or tangential clamping force onto the clamping units 8.

[0074] As depicted in particular schematically in FIGS. 2a and 2b, with the aid of the adjusting device 20, the clamping units 8 are brought from an open position 8(I) (dashed) into a closed position 8(II), wherein in the closed position 8(II) the clamping units abut against the workpiece with a certain clamping force. In the exemplary embodiments depicted in the Figures, the transition from an open position 8(I) into a closed position 8(II) is effected by a rotational movement of the clamping units 8.

[0075] For this purpose, as schematically indicated in FIGS. 2a and 2b, the clamping units 8 can include, for example, rotary discs 22 on which eccentric clamping cylinders 10 are supported that in turn come into contact with the workpiece 2. Alternatively, of course, the clamping unit 8 itself, for example, the clamping cylinder 10, can also be elliptical so that a corresponding rotational movement leads to the application of a clamping force to the workpiece 2.

[0076] Furthermore, FIG. 2a shows that a carrier 60 is attached to each rotary disc 22; the carriers 60 are offset with respect to a center point M of the workpiece holding device 6, and the clamping elements 10 are attached to the carriers 60. The carriers 60 are pivoted by a movement of the rotary disc 22 so that the clamping elements 10 directly contact the workpiece 2 (closed position) or are spaced from it (open position). Here the adjusting device 20 ensures that the rotational movement of the rotary disc 22 is effected simultaneously and synchronously.

[0077] Alternatively and, as depicted in FIG. 2b, the clamping cylinders 10 can be supported eccentrically on rotary discs 22 so that a movement of the rotary discs 22 leads to a local displacement of the clamping cylinders 10.

[0078] FIGS. 3 to 8 show further different examples, wherein in FIGS. 3 to 5 three clamping units 8-1, 8-2, and 8-3 are synchronously clamped while in FIGS. 6 to 8 four clamping units 8-1, 8-2, 8-3 and 8-4 four are synchronously clamped.

[0079] Here, the figures each show various embodiments of how, for example, such rotary disks 22 or, in general, the clamping units 8, can be rotated in order to synchronously exert a clamping force on the workpiece. A carrier 60 is attached to each of the rotary discs 22; the carriers 60 are disposed offset with respect to a center point M of the workpiece holding device 6, and the clamping elements 10 are attached to them. As also depicted in FIGS. 2a and 2b, the carriers 60 are pivoted by a movement of the rotary disc 22 so that the clamping elements 10 directly contact the workpiece 2 (closed position) or are spaced from it (open position). Here the adjusting device 20 ensures that the rotational movement of the rotary disc 22 is effected simultaneously and synchronously.

[0080] FIGS. 3 and 6 each show exemplary embodiments in which three clamping units 8-1, 8-2, 8-3, (FIG. 3) or four clamping units 8-1, 8-2, 8-3 and 8-4, (FIG. 4) are synchronously movable by the adjusting device 20, which in the exemplary embodiment depicted is represented by a chain or a belt 20, from an open position I into a closed position II. The closed position II is represented by abutment of the clamping element 10-1, 1-10-3, or 10-4 against the workpiece 2, while in the open position the clamping elements 10-1, 1-10-3 or 10-4 are spaced from the workpiece 2. The mechanical coupling via the chain or the belt 20 has the advantage that all clamping units are rotated synchronously and simultaneously with an identical force and thus abut against the workpiece 2 with the same clamping force. No further control device is needed here since the chain or the belt directly rotates all clamping units.

[0081] FIGS. 4 and 7 each show an exemplary embodiment for three or four clamping units in which the clamping units are rotated from an open position into a closed position via actuators 20-1, 20-2, and 20-3 or 20-4 disposed between them. The closed position II is represented by abutment of the clamping element 10-1, 1-10-3, or 10-4 against the workpiece 2, while in the open position the clamping elements 10-1, 1-10-3 or 10-4 are spaced from the workpiece 2. Here the actuators can be, for example, gears that interact with a gearing on the clamping unit 8 or the rotary disc 22. Here the intermediate actuators 20-1 to 20-3 (FIG. 4) or intermediate actuators 20-1-20-4 (FIG. 7) can each be driven separately or via a common central element (not depicted) in order to achieve the synchronous rotation and thus the synchronous application of the clamping force. Similarly, only one of the actuators 20-1 may also be rotated since the rotation acts on all elements simultaneously via the mechanical coupling between the elements 8 or 20. In the alternative, the actuators could be friction discs that fictionally engage one another and the rotary discs 22 without the use of gears.

[0082] FIG. 5 shows an exemplary embodiment in which the clamping units 8-1, 8-2 and 8-3 are set in rotation by a centrally disposed adjusting device 20, for example, using a central gear 20 that meshes with corresponding gearings on the clamping device 8 or the rotary disc 22, in order to be brought from an open into a closed position. The closed position II is represented by abutment of the clamping element 10-1, 1-10-3, or 10-4 against the workpiece 2, while in the open position the clamping elements 10-1, 1-10-3 or 10-4 are spaced from the workpiece 2. Here, for example, the adjusting device can be configured as a central gear that engages in corresponding gears on the clamping units 8-1, 8-2 and 8-3, or in the alternative, as a friction disc that frictionally engages the rotary discs without the use of gears.

[0083] FIG. 8 shows an exemplary embodiment in which the adjusting device 20 is installed in one of the clamping units 8-1, 8-2, 8-3 or 8-4, in particular the rotary disc 22-1. Because the rotary discs 22-1-22-4 mesh with one another, the movement of one rotary disc 22-1 also induces the movement of the other rotary discs 22-2-22-4. It is thus sufficient that only one rotary disc functions as an adjusting device 20 which actively rotates the clamping unit from an open position into a closed position. Since the clamping units 8-1 to 8-4 are in engagement with one another as depicted in FIG. 8, the rotation of one clamping unit 8-1 is transmitted to the clamping unit 8-1, from there to the clamping unit 8-3, and there in turn to the clamping unit 8-4. The closed position II is represented by abutment of the clamping element 10-1, 1-10-3, or 10-4 against the workpiece 2, while in the open position the clamping element 10-1, 1-10-3 or 10-4 are spaced from the workpiece 2.

[0084] Even when a radially outwardly applied clamping force is shown in the Figures, it is clear to a person skilled in the art that a radially inwardly applied clamping force can also be generated with the same system, for example, by the clamping cylinders 10 simply being attached to longer carriers and abutting radially outwardly against the workpiece 2. Here the clamping itself can also be applied, for example, by the same system made of rotatable rotary discs that are synchronously rotated with the aid of an adjusting device. Thus with the same basic system made of an adjusting device and rotary disc, both a radially outwardly and a radially inwardly directed synchronous clamping force can be applied so that the workpiece holding device is flexibly usable for the widest variety of applications.

[0085] Overall, with the aid of the synchronous application of a clamping force, a space-saving and easy-to-operate system can be provided that allows a simple force regulation and position regulation. Such a system is also particularly robust, since a complicated electronic controlling of the individual clamping elements can be omitted, since this system applies a clamping force onto the workpiece simultaneously and uniformly via its mechanical coupling.

[0086] As used herein, a controller may be a programmable hardware component that 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.

[0087] 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 device

[0088] 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.

[0089] 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

[0090] 100 Hardening system [0091] 2 Workpiece [0092] 4 Induction coil [0093] 5 Main body [0094] 6 Workpiece holding device [0095] 8 Clamping unit [0096] 10 Clamping element [0097] 12 Support unit [0098] 13 Measuring device [0099] 14 Drive unit [0100] 15 Controller [0101] 16 Support element [0102] 18 Friction roller [0103] 20 Adjusting device [0104] 22 Rotary disc [0105] 22 Radially outer side of the workpiece [0106] 24 Radially inner side of the workpiece [0107] 60 Carrier