Method for Creating Elevations in a Workpiece, Apparatus and Product

Abstract

The invention relates to a method for creating elevations (21) in a workpiece (1) by forming techniques. In a first step, depressions (11, 12) are created, with dimensions that differ from dimensions of depressions (20) to be created between the elevations (21). In a second step, the elevations (21) are created from regions (13) between the depressions (11, 12). The invention also relates to an apparatus for implementing the method and to a product thereby created.

Claims

1.-15. (canceled)

16. A method for forming elevations in a workpiece, comprising the steps of: in a first step, producing in the workpiece, wherein the depressions include a first portion of the depressions having dimensions after the first step which differ from dimensions of a second portion of the depressions, and in a second step, producing the elevations from regions of the workpiece between the depressions.

17. The method according to claim 16, wherein in the first step, the second portion of the depressions are produced in the workpiece, and the second portion of the depressions have different dimensions from the first portion of the depressions.

18. The method according to claim 17, wherein in the first step, the first portion of the depressions have larger dimensions and are at smaller spacings from a longitudinal axis of the workpiece than the second portion of the depressions.

19. The method according to claim 18, wherein in the first step, the first portion of the depressions having larger dimensions are larger than dimensions of the first portion of the depressions after the second step.

20. The method according to claim 19, wherein in the first step, the first portion of the depressions and the second portion of the depressions alternate with one another in a regularly or irregularly.

21. The method according to claim 20, wherein in the first step, the depressions are produced such that material from regions of the workpiece in which the first portion of the depressions which will have larger dimensions come into contact with a tool earlier than material from regions in which the second portion of the depressions which will have smaller dimensions are to be produced.

22. The method according to claim 21, wherein in the second step, the elevations are produced such that material of the workpiece from the second portion of the depressions of smaller dimensions comes into contact with a tool earlier than material of the workpiece from the first portion of the depressions of larger dimensions.

23. The method according to claim 22, wherein in the second step, the elevations are produced such that material of the workpiece from the second portion of the depressions of smaller dimensions flows in the direction of the first portion of the depressions of larger dimensions.

24. The method according to claim 16, wherein in the first step, the first portion of the depressions are produced in the workpiece such that the first portion of the depressions have larger dimensions than depressions which are to be produced between the elevations.

25. The method according to claim 24, wherein in the first step, the first portion of the depressions are produced at a radial spacing from one another such that, in the second step for producing the elevations, there is space present within the radial spacing for at least one additional depression to be produced between the elevations.

26. The method according to claim 25, wherein in the first step, the space for the at least one additional depression remains in an unworked state.

27. An apparatus for forming elevations in a workpiece, comprising: a tool having a cavity configured to accommodate the workpiece; wherein the tool includes teeth projecting into the cavity, end regions of the teeth of the tool are at different spacings from a longitudinal axis of the tool, and at least two of the teeth of the tool have different dimensions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG. 1 shows a section through an example of a workpiece which is to be subjected to a forming operation in accordance with an embodiment of the present invention,

[0035] FIG. 2 shows a section through a schematic illustration of the forming operation for a workpiece during the first step of the method in accordance with an embodiment of the present invention,

[0036] FIG. 3 shows a three-dimensional illustration of the cut-away tool for the first step of the method in accordance with an embodiment of the present invention,

[0037] FIG. 4 shows a three-dimensional illustration of the workpiece formed by the first step in accordance with an embodiment of the present invention,

[0038] FIG. 5 shows a three-dimensional illustration of the cut-away tool for the second step of the method in accordance with an embodiment of the present invention, and

[0039] FIG. 6 shows a three-dimensional illustration of the definitively formed workpiece in accordance with an embodiment of the present invention.

BRIEF DESCRIPTION

[0040] FIG. 1 shows a section through the workpiece 1 prior to the forming operation. The workpiece 1 is configured as being essentially rotationally symmetrical about the longitudinal axis 5.

[0041] FIG. 2 illustrates schematically how the workpiece 1 is located in the cavity which is enclosed by the first tool 101. A force-exerting device 105 is located above the workpiece 1 and, by moving along the longitudinal axis 5 of the workpiece 1, subjects the workpiece 1 to a mechanical force. As a result of this application of force, the material of the workpiece 1 flows in the direction of the inner wall of the first tool 101 and adapts itself to the structure provided in the inner wall. This is correspondingly the case in the second step of the method, using the second tool 102. In the configuration illustrated here, the longitudinal axis of the first tool 101 (and also, in the second step, of the second tool 102) and the longitudinal axis of the workpiece 1 which is to be subjected to a forming operation coincide along a longitudinal axis 5.

[0042] FIG. 3 shows a part of a tool 101 which is used, by way of example, in the first step of the method.

[0043] An illustration is given of a plurality of teeth of the inner structure which project to different extents out of and/or into the interior space, which in this case is cut away. There are two differently sized types of teeth present in the example shown. The two types of teeth give rise to two differently sized depressions in the workpiece. In this arrangement, the different size of the teeth and the fact that they project into the enclosed interior space gives rise to the portions of the workpiece 1 coming into contact with the first tool 101 in some cases earlier and in some cases later, and therefore also being subjected to a more or less pronounced forming operation. The first workpiece 101 is configured, for example, such that first of all a flank, then the foot, and only finally the head, of a tooth comes into contact with the material of the workpiece 1. Accordingly, the different teeth are to be configured such that the respective flanks come into contact with the workpiece 1 earlier or later.

[0044] The forming operation in the first step using the first tool 101 gives rise to the blank with depressions which is illustrated in FIG. 4.

[0045] The workpiece 1 which has been subjected to a forming operation by way of the first step has deeper or larger depressions 11 and shallower or smaller depressions 12. In the configuration illustrated, the different depressions 11, 12 alternate with one another radially around it. The depressions 11, 12 are located mainly on the outer side surface of the workpiece 1 and are inclined inward to a more pronounced extent in the direction of the upper end side. In the second step, the material 13 in the regions between the depressions 11, 12 is subjected to the forming operations which produce the elevations (alternatively referred to, depending on the configuration, for example as teeth of a toothing formation) of the workpiece 1. In an alternative configuration, in the case of a workpiece which has been subjected to a forming operation—not illustrated here—the radial portions between the larger depressions 11 are free of depressions.

[0046] In the second step of the method, the workpiece 1 of FIG. 4 is located in a similar construction to that in FIG. 2, although use is being made of the second tool 102, which is illustrated by way of example in FIG. 5.

[0047] The second tool 102 likewise has teeth, although these, in contrast to the first tool 101, are of just one type and are designed so as to correspond to the dimension of the valleys between the elevations of the finished product. The teeth therefore provide for the finished dimension.

[0048] Since the outer contour of the workpiece 1 has larger and smaller depressions 11, 12 following the first step, it is also the case that the respective material of the workpiece 1 comes into contact with the second tool 102 later or earlier. In particular, the arrangement of the depressions 11, 12 of the workpiece 1 (cf. FIG. 4) and the structure of the second tool 102 are such that the regions around the smaller depressions 12 are more in contact with the second tool 102 than the regions around the larger depressions 11. As a result, the material around the smaller depressions 12 flows in the direction of the larger depressions 11. Following the second step, the larger depressions 11 and the smaller depressions 12 form the valleys 20 between the elevations 21 of the workpiece 1. Since the valleys 20 have a predefined finished dimension, it is therefore the case that, in the second step, the larger depressions 11 are reduced in size to the finished dimension and, conversely, the smaller depressions 12 are increased in size to give the finished dimension.

[0049] The definitively formed workpiece 1 is illustrated in FIG. 6. It is possible to see here the elevations 21 and the depressions 20 located therebetween, both with finished dimensions.

[0050] The production method will be briefly summarized once again:

[0051] The starting point is a—preferably rotationally symmetrical or circular-cylindrical—workpiece 1, in which elevations 21 and depressions 20 located therebetween are to be produced with finished dimensions.

[0052] In a first step, larger depressions 11 and smaller depressions 12 are produced in the workpiece 1. In one configuration, the larger depressions 11 are larger than the final depressions 20.

[0053] In a second step, the elevations 21 are produced from the material of the regions 13 between the differently sized depressions 11, 12. The material around the smaller depressions 12 here flows in the direction of the larger depressions 11.

[0054] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.