DEVICE AND METHOD FOR MACHINING A WORKPIECE, AND COMPUTER PROGRAM PRODUCT FOR CONTROLLING A DEVICE FOR MACHINING A WORKPIECE

Abstract

A device, a method and a computer program product for machining a workpiece, in particular for cutting teeth into a workpiece, includes a base, a workpiece spindle mounted rotatably about a first axis (A) for receiving the workpiece, a first machining head having a first tool spindle mounted rotatably relative to a first tool axis for receiving a first machining tool, and a second machining head having a second tool spindle mounted rotatably relative to a second tool axis for receiving a second machining tool. At least the first machining head is provided with the first machining tool for power skiving the workpiece and at least the second machining head is variably positionable and/or variably orientable relative to the first machining head and independently of the first machining head.

Claims

1-16. (canceled)

17. A device for machining a workpiece, the device comprising: a base; a workpiece spindle mounted rotatably about a first axis (A) for receiving the workpiece; a first machining head with a first tool spindle mounted rotatably relative to a first tool axis for receiving a first machining tool; a second machining head for receiving a second machining tool; wherein at least the first machining head is provided with the first machining tool for power skiving the workpiece; and wherein the second machining head is variably positionable and/or variably orientable relative to the first machining head and independently of the first machining head.

18. The device as claimed in claim 17, wherein the second machining head is freely positionable and/or freely orientable relative to the first machining head.

19. The device as claimed in claim 17, wherein the first machining head and the second machining head are arranged on the base so as to be displaceable relative to a first direction (x) independently of one another.

20. The device as claimed in claim 19, wherein the first machining head and the second machining head are arranged on the base so as to be displaceable relative to a second direction (y) independently of one another.

21. The device as claimed in claim 20, wherein the first machining head and the second machining head are arranged on the base so as to be displaceable relative to a third direction (z) independently of one another.

22. The device as claimed in claim 17, wherein the first machining head is mounted pivotably with respect to a first pivot axis running perpendicularly relative to the first tool axis.

23. The device as claimed in claim 17, wherein the second machining head is mounted pivotably with respect to a second pivot axis running perpendicularly relative to a second tool axis of a second tool spindle mounted rotatably relative to the second tool axis.

24. The device as claimed in claim 17, wherein the first machining head provided with the first machining tool is brought into engagement with a first portion of the workpiece, and wherein the second machining head is provided with the second machining tool and is brought into simultaneous engagement with a second portion of the workpiece, and wherein the first portion and the second portion of the workpiece are offset to one another axially and/or radially relative to the first axis (A).

25. The device as claimed in claim 17, wherein the second machining head has a second tool spindle mounted rotatably relative to a second tool axis for receiving the second machining tool.

26. The device as claimed in claim 25, wherein the second machining head is provided with the second machining tool for power skiving the workpiece.

27. The device as claimed in claim 26, wherein the first machining tool and the second machining tool are configured for simultaneous power skiving of the workpiece.

28. The device as claimed in claim 17, wherein the first machining head is provided with the first machining tool and/or the second machining head is provided with the second machining tool, and wherein the first machining tool and/or the second machining tool are configured for producing and/or machining a first toothing and/or a second toothing of the workpiece.

29. The device as claimed in claim 26, further comprising a controller for controlling the first machining head and/or the second machining head such that the following correlation applies: $n_c=n_b*\left(\frac{z_b}{z_2}\right)+v_{z2}*\left(\frac{u_{dz2}}{z_2}\right)=n_a*\left(\frac{z_a}{z_1}\right)+v_{z1}*\left(\frac{u_{dz1}}{z_1}\right),\mathrm{where}:$ $\begin{array}{c}{n}_c:\mathrm{rotation}\mathrm{speed}\mathrm{of}\mathrm{workpiece}\mathrm{axis}\\ n_a:\mathrm{rotation}\mathrm{speed}\mathrm{of}1\mathrm{st}\mathrm{tool}\mathrm{spindle}\\ n_b:\mathrm{rotation}\mathrm{speed}\mathrm{of}2\mathrm{nd}\mathrm{tool}\mathrm{spindle}\\ z_a:\mathrm{tooth}\mathrm{count}\mathrm{of}1\mathrm{st}\mathrm{skiving}\mathrm{tool}\\ z_b:\mathrm{tooth}\mathrm{count}\mathrm{of}2\mathrm{nd}\mathrm{skiving}\mathrm{tool}\\ z_1:\mathrm{tooth}\mathrm{count}\mathrm{of}1\mathrm{st}\mathrm{toothing}\mathrm{of}\mathrm{workpiece}\\ z_2:\mathrm{tooth}\mathrm{count}\mathrm{of}2\mathrm{nd}\mathrm{toothing}\mathrm{of}\mathrm{workpiece}\\ v_{z1}:\mathrm{advance}\mathrm{speed}\mathrm{of}\mathrm{axial}\mathrm{axis}\left(z\right)\mathrm{of}1\mathrm{st}\mathrm{tool}\mathrm{spindle}\\ v_{z2}:\mathrm{advance}\mathrm{speed}\mathrm{of}\mathrm{axial}\mathrm{axis}\left(z\right)\mathrm{of}2\mathrm{nd}\mathrm{tool}\mathrm{spindle}\\ u_{\mathrm{dzi}}=\mathrm{axial}-\mathrm{differential}-\mathrm{constant}=\sin \left(\frac{{}_i}{m_{\mathrm{ni}}*}\right);\mathrm{where}i=1,2\end{array}$ wherein i=1 indicates the first skiving tool or first toothing of the workpiece, and I=2 the second skiving tool or second toothing of workpiece, and wherein: .sub.i: slope angle of teeth of worklece i m.sub.ni: normal modulus of toothing i.

30. A method for machining a workpiece, comprising: arranging a workpiece to be machined on a workpiece spindle mounted rotatably about a first axis (A) of a device for workpiece machining; power skiving at least a first portion of the workpiece by means of a first machining tool, which is arranged on a first tool spindle of a first machining head; simultaneous machining a second portion of the workpiece by means of a second machining tool, which is arranged on a second machining head that is variably positioned and/or variably oriented relative to the first machining head and independently of the first machining head.

31. The method as claimed in claim 30, wherein the second portion of the workpiece is machined by power skiving by means of the second machining tool, which is arranged on a second tool spindle of the second machining head, and wherein the first machining head, the first tool spindle, the second machining head, the second tool spindle and the workpiece spindle are actuated simultaneously by means of a controller such that the following correlation applies: $n_c=n_b*\left(\frac{z_b}{z_2}\right)+v_{z2}*\left(\frac{u_{dz2}}{z_2}\right)=n_a*\left(\frac{z_a}{z_1}\right)+v_{z1}*\left(\frac{u_{dz1}}{z_1}\right)$

32. A computer program product for controlling a device for machining a workpiece, wherein the device comprises a workpiece spindle mounted rotatably about a first axis (A) for receiving the workpiece, and a first and a second machining head, wherein the first machining head has a first tool spindle mounted rotatably about a first tool axis for receiving a first machining tool, wherein the second machining head is configured for receiving a second machining tool, and wherein the computer program product comprises commands that when executed on a computer or a controller of the device for machining a workpiece causes the computer or controller: to bring the first machining head with the machining tool arranged thereon into skiving engagement with a first portion of the workpiece and to carry out a first power skiving process; and at the same time or temporally overlapping therewith, to machine a second portion of the workpiece by means of the second machining tool, and in so doing, to variably position and/or variably orient the second machining head relative to the first machining head and independently of the first machining head.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0071] Further objectives, features and advantageous possible applications of the device and method are explained below in the following description of exemplary embodiments with reference to the accompanying drawing figures. In the drawings:

[0072] FIG. 1 shows a schematic view of an exemplary embodiment of a device for gear-cutting of a workpiece, viewed from the front.

[0073] FIG. 2 shows a schematic illustration of the device, viewed from the side.

[0074] FIG. 3 shows a further schematic illustration of the device, viewed from above.

[0075] FIG. 4 shows a perspective illustration of the device from FIGS. 1 to 3.

[0076] FIG. 5 shows a perspective illustration of an exemplary embodiment in which two machining tools are simultaneously in engagement with a workpiece.

[0077] FIG. 6 shows an illustration of FIG. 5 viewed from the side.

[0078] FIG. 7 shows a further illustration of FIG. 5 viewed from above.

[0079] FIG. 8 shows an illustration of a further exemplary embodiment in which the first and second machining tools are simultaneously in engagement with an internal toothing of a workpiece.

[0080] FIG. 9 shows a top view of the arrangement in FIG. 8, viewed from above.

[0081] FIG. 10 shows a flow diagram of an exemplary embodiment of a method for simultaneous machining of a workpiece by means of a device described herein.

DETAILED DESCRIPTION OF EXEMPLARY EMODIMENTS

[0082] FIG. 1 shows an exemplary embodiment of a device 1 according to the invention for cutting teeth in a workpiece. The device 1 is configured as a gear-cutting device. It has a base 2 and a workpiece carrier 3. The workpiece carrier 3 is arranged on the stationary base 2. A workpiece spindle 4 is arranged rotatably on the workpiece carrier 3. The workpiece spindle 4 is rotatable relative to a first axis (A), in particular can be driven in rotation by means of a drive. The first axis is accordingly also described as the workpiece axis (A). Typically, the workpiece spindle 4 is equipped with a corresponding spindle drive 9 in order to rotate the workpiece spindle 4 under control in regulatable fashion. The spindle drive 9 is to this extent typically signal-transmissively coupled to a controller 50. The workpiece 5 (see FIGS. 5 to 9) can be releasably attached, e.g. clamped, to the workpiece spindle 4. By means of the rotatable mounting of the workpiece spindle 4, the workpiece 5 can be turned relative to the first axis (A) for the purpose of workpiece machining.

[0083] The gear-cutting device 1 furthermore has a first machining head 11 and a second machining head 21. A first tool spindle 12 is mounted on the first machining head 11 so as to be rotatable with respect to a first tool axis 18. Similarly, a second tool spindle 22 is mounted on the second machining head 21 so as to be rotatable with respect to a second tool axis 28. The first and second tool spindles 12, 22 serve to receive corresponding first and second machining tools 30, 40, as shown in detail for example in FIGS. 5 to 9.

[0084] At least the first machining head 11 is configured for carrying out a power skiving of the workpiece 5. Accordingly, at least the first machining head 11 can be actuated by a controller 50 for performing a skiving process and moved relative to the workpiece 5.

[0085] Similarly, the second machining head 21 may also be configured for carrying out a power skiving process on one and the same workpiece 5. The second machining head 21 can also be controlled and actuated with respect to its position and/or orientation by the controller 50. It is here provided in particular that the first machining head 11 and the second machining head 21 are in principle freely positionable and/or freely orientable relative to one another. In particular, it is provided that the first machining head 11 and the second machining head 21 are variably positionable and/or variably orientable relative to one another. This is achieved by the mutually independent mounting and displacement of the respective machining heads 11, 21 on the base 2.

[0086] The mutually independent free positioning and/or free orientation of the two machining heads 11, 21, and also a mutually independent activation or control of drives for rotating the corresponding tool spindles 12, 22, serve in particular for simultaneous performance of two skiving processes on one and the same workpiece 5. In principle, the free positionability and/or free orientability, and also the mutually independent actuation of the tool spindles 12, 22, can be achieved in widely varying and different fashions.

[0087] In the present exemplary embodiment, the first machining head 11 is mounted displaceably on a first carrier 10 via a positioning device 14. The second machining head 21 is also mounted on a second carrier 20 via a corresponding positioning device 24. The first carrier 10 is mounted displaceably with respect to a second direction (y) relative to the base 2. Similarly, the second carrier 20 is mounted displaceably relative to the second direction (y) on the base 2.

[0088] The first carrier 10 is typically mounted on the base 2 in the second direction (y) via a corresponding positioning device 16. Similarly, the second carrier 20 is arranged displaceably in the second direction (y) on the base 2 via a further positioning device 26. The positioning devices 16, 26 may be configured as slide guides. Corresponding and mutually engaging guide rails may here be provided on the carriers 10, 20 and also on the base 2.

[0089] The positioning devices 16, 26 may in particular be provided with a drive, typically an electric drive, by means of which the carriers 10, 20 can be moved independently of one another relative to the base 2 along the second direction (y) by means of the controller 50. The controller 50 is in particular coupled to the electric drives in order to implement a correspondingly required displacement movement of the carriers 10, 20 relative to the base 2 and also relative to one another.

[0090] In the present case, the positioning devices 16, 26 are configured as one-dimensional slide guides, by means of which the carriers 10, 20 can be moved relative to the base 2 only in the second direction (y). In principle however, it is also conceivable that the positioning devices 16, 26 are configured as two-dimensional positioning devices, for example as compound slides.

[0091] The machining heads 11, 21 are similarly displaceably or movably mounted on the respective carriers 10, 20 by means of corresponding positioning devices 14, 24. The first machining head 11 is displaceably mounted by means of the positioning device 14 on the first carrier 10 so as to be longitudinally displaceable with respect to the first direction (x) and with respect to the third direction (z). Similarly, the positioning device 24 is configured as a two-dimensional positioning device. By means of the positioning device 24, the second machining head 21 is arranged on the carrier 20 displaceably with respect to the first direction (x) and with respect to the third direction (z).

[0092] The positioning devices 14, 24 each have a slide 15, 25, arranged for example on the carrier 10, 20. The slide 15, 25 may in particular be implemented or configured as a compound slide so that the first machining head 11 is mounted on the first carrier 10 by means of the slide 15 of the positioning device 14 so as to be movable or displaceable with respect to the first direction (x) and with respect to the third direction (z). Similarly, the second machining head 21 may be mounted on the second carrier 20 by means of the slide 25 of the positioning device 24 so as to be longitudinally displaceable in the first direction (x) and in the third direction (z).

[0093] The signaling connection between the central controller 50 and the positioning devices 14, 16, 24, 26 is not explicitly shown here. For reasons of clarity, the mutual engagement of guide rails of the slides 15, 25 with corresponding guide elements on the machining heads 11, 21 is not explicitly shown. The positioning devices 14, 16, 24, 26 are typically implemented with commercially available guide rails or motorized slide guides.

[0094] As also illustrated in FIGS. 1, 2 and 4, the first machining head 11 is mounted on the first carrier 10 so as to be rotatable or pivotable with respect to a first pivot axis 17 and hence also relative to the base 2. Similarly, the second machining head 21 is mounted on the second carrier 20 so as to be rotatable or pivotable with respect to a second pivot axis 27 and hence also relative to the base 2. By means of the rotatable mounting with respect to the first and second pivot axes 17, 27, the respective first and second tool axes 18, 28 of the first and second machining heads 11, 21 can be changed variably as required.

[0095] This allows in particular free positionability or orientability of the first and second machining heads 11, 21 relative to one another, and also relative to the base 2. The first and second pivot axes 17, 27 are typically each coupled to a dedicated drive which is connected for signaling purposes to the controller 50.

[0096] FIG. 1 shows a first spindle drive 13 which is coupled torque-transmissively to the first tool spindle 12. Furthermore, the second machining head 21 has a second spindle drive 23 which is coupled torque-transmissively to the second tool spindle 22.

[0097] FIG. 1 furthermore shows as an example a first drive unit 19 of the first machining head 11, and a second drive unit 29 of the second machining head 21. The first and second drive units 19, 29 and the first and second spindle drives 13, 23 are connected signal-transmissively to the controller 50. The drive units 19, 29 represent all drives of the carrier 10, 20 and machining heads 11, 21 so as to place the latter in any required position or orientation and move them with the required speed during the machining processes.

[0098] The spindle drives 9, 13, 23 are also connected signal-transmissively to the controller 50. The controller 50 can thus individually regulate and control as required the rotation speeds of the workpiece spindle 4, the first tool spindle 12 and the second tool spindle 22.

[0099] The drive of the pivot axes 17, 27 (not shown here) allows motorized pivoting, controllable by the controller 50, of the machining heads 11, 21 relative to the respective pivot axes 17, 27.

[0100] By means of the device 1 shown in FIGS. 1 to 4, different or identical toothings can be machined or produced on one and the same workpiece 5 simultaneously but at least temporally overlapping.

[0101] FIGS. 5 to 7 show a mutual engagement of two machining tools 30, 40 with one and the same workpiece 5. The first machining tool 30 is clamped in the first tool spindle 12. The first machining tool 30 has a first tool toothing 31, and axially offset thereto a second tool toothing 32. The first and second tool toothings 31, 32 are typically different toothings. These may differ from one another with respect to tooth count, tooth geometry, tooth orientation and also their radius or axial extent. Similarly, the second machining tool 40, which is arranged on the second tool spindle 22, has a first tool toothing 41 and a second tool toothing 42. These toothings 41, 42 are also configured or arranged axially offset to one another on the machining tool 40.

[0102] The workpiece 5 to be machined has a first portion 53 and a second portion 54. In the region of the first portion 53 lies a first toothing 51 which is produced, created and/or machined by means of the second tool toothing 42 of the second machining tool 40. The second portion 54 of the workpiece 50 has a second toothing 52. This second toothing 52 is axially spaced from the first toothing 51 or axially adjoins the first toothing 51. This second toothing 52 is in engagement with the first tool toothing 31 of the first machining tool 30 and is produced and/or machined by said first machining tool 30.

[0103] It is clear from FIGS. 5 to 7 in particular that the two machining tools 30, 40 come to lie at a predefined radial distance from one another on approximately radially opposite or diametrically opposite sides of the workpiece 5, or stand in engagement with corresponding first and second portions 53, 54 of the workpiece 5 simultaneously or with a temporal overlap. The tool toothings 31, 42 which stand simultaneously in engagement with axially offset portions 54, 53 of the workpiece 5, typically each perform a power skiving process. The two machining tools 30, 40 are here guided by the respective machining heads 11, 21 under program control by the controller 50.

[0104] Since the two skiving processes take place simultaneously, the dynamic control parameters of the respective machining heads 11, 21 or their tool spindles 12, 22 are matched to one another according to the following correlation with the above-mentioned variables:

[00004]$n_c=n_b*\left(\frac{z_b}{z_2}\right)+v_{z2}*\left(\frac{u_{dz2}}{z_2}\right)=n_a*\left(\frac{z_a}{z_1}\right)+v_{z1}*\left(\frac{u_{dz1}}{z_1}\right).$

[0105] The controller 50, which is connected for signaling purposes to both the drive of the workpiece spindle 4 and to all drives of the machining heads 11, 21 and the associated tool spindles 12, 22, can implement a corresponding motion coupling of the two tool spindles 12, 22 or respective machining heads 11, 21.

[0106] The illustration of FIG. 5 furthermore shows the axis intersection angles .sub.1 or .sub.2. The axis intersection angle .sub.1 extends between the rotational axis of the workpiece spindle 4 and the first tool axis 18. The axis intersection angle .sub.2 extends between the rotational axis of the workpiece spindle 4 and the second tool axis 28, as indicated in FIG. 5.

[0107] FIGS. 8 to 9 show a further exemplary embodiment in which the two machining heads 11, 21 with the machining tools 30, 40 arranged thereon stand simultaneously in rolling or skiving engagement with an internal toothing of a workpiece 5. First and second portions 53, 54 of the workpiece 5 are here at a radial distance. They may in particular lie diametrically opposite one another, so that for example the first machining tool 30 with a first tool toothing 31 is in engagement with the first portion 53, and the second machining tool 40 with its first tool toothing 41 is in engagement with an also internal second portion 54 of the internal toothing 55 of the workpiece 5. Here, the two portions 53, 54 may be arranged opposite one another on the internal toothing 55.

[0108] The simultaneous engagement of two machining tools 30, 40 with one and the same toothing 55 can accelerate the entire machining or machining process for production of the internal toothing 55. This is also applicable similarly to external toothings.

[0109] The flow diagram in FIG. 10 shows schematically the method for simultaneous power skiving of one and the same workpiece 5. In a first step 100, the workpiece 5 to be toothed is arranged on a workpiece spindle 4, mounted rotatably about a first axis (A), of an above described device 1. In the following step 102, power skiving of at least a first portion 53 of the workpiece 5 takes place by means of a first machining tool 30. The first machining tool 30 is arranged on the first tool spindle 12 of a first machining head 11.

[0110] The first machining head 11 or first tool spindle 12, and also the workpiece spindle 4, are driven under program control or controlled by the controller 50. Simultaneously, in a further step 104, a second portion 54 of the workpiece 5 is machined by means of the second machining tool 40. The second machining tool 40 is arranged on the second tool spindle 22 of a second machining head 21.

[0111] The second machining head 21 is here variably positioned and/or variably oriented relative to the first machining head 11 and independently of the first machining head 11, in order to machine the second portion 54 of the workpiece. Advantageously, in both steps 102, 104, a first skiving process and a second skiving process take place simultaneously or at least temporally overlapping.