Method for Straightening of Radial Run-Out Faults or Linearity Faults on Elongate Workpieces, and Measuring Device, Straightening Machine, and Straightening System Thereof

Abstract

In the straightening of radial run-out faults or linearity faults on elongate workpieces having at least one toothed region having peaks and troughs of the teeth of said toothed region, such as on toothed shafts or toothed racks, for ascertaining deviations from the ideally straight workpiece, the locations of the surfaces of the not yet straightened workpiece that form a reference plane are scanned at least at points or in portions on or in the region on the active reference circle or pitch circle, respectively, of the toothing that lies between the peaks and troughs of the teeth. The resulting measured items of data are utilized by the straightening machine such that a workpiece that is as ideally straight as possible at least in the toothed region is achieved by the straightening. The elevated locations of the tooth heads of the toothed region that form the peaks of the teeth and the elevated locations of neighboring tooth surfaces that lie in the reference plane are detected, and the height differentials of the elevated locations of the tooth heads in relation to the elevated locations of neighboring tooth surfaces that lie in the reference plane are ascertained. The height differentials are utilized by the straightening machine as corrective measured items of data such that said height differentials are considered when straightening the workpiece so as to form a workpiece that is as ideally straight as possible in the reference plane.

Claims

1. A method for straightening radial run-out faults or linearity faults on an elongate workpiece having at least one toothed region having peaks and troughs of the teeth of said toothed region, such as on a toothed shaft or a toothed rack, whereby for ascertaining deviations from the ideally straight workpiece, reference values, in particular the locations of the surfaces of the not yet straightened workpiece that form a reference plane, are scanned at least at points or in portions on or at or in the region of the toothing, however at least more or less close to the in particular active reference circle that lies between the peaks and troughs of the teeth; and whereby the resulting measured items of data are utilized by a straightening machine such that a workpiece that is as ideally straight as possible at least in the toothed region is achieved by the straightening; wherein the elevated locations of neighboring tooth surfaces that lie in the reference plane are detected in a tactile manner; and wherein the elevated locations of neighboring tooth surfaces that lie in the reference plane are utilized by the straightening machine as corrective measured items of data such that said elevated locations are considered when straightening the workpiece so as to form a workpiece that is as ideally straight as possible in the reference plane.

2. A method for straightening radial run-out faults or linearity faults on an elongate workpiece as claimed in the preamble of claim 1, wherein the elevated locations of the tooth heads of the toothed region that form the peaks of the teeth, and the elevated locations of neighboring tooth surfaces that lie in the reference plane are detected; wherein the height differentials of the elevated locations of the tooth heads in relation to the elevated locations of neighboring tooth surfaces that lie in the reference plane are ascertained; and wherein the height differentials are utilized by the straightening machine as corrective measured items of data such that said height differentials are considered when straightening the workpiece so as to form a workpiece that is as ideally straight as possible in the reference plane.

3. The method as claimed in claim 1, wherein a tactile measuring installation having a ball caliper is used for determining the height differentials.

4. The method as claimed in claim 3, wherein a ball caliper of the measuring installation slides up and down on the tooth flanks of the teeth of the toothed region.

5. A method as claimed in of claim 1, wherein measuring of the workpiece, in particular of the toothed region of the workpiece, that is performed before the straightening of the workpiece is relocated out of a straightening machine so as to be ahead of the straightening machine, and/or wherein measuring of the workpiece, in particular of the toothed region of the workpiece, that is performed before the straightening of the workpiece is performed outside a straightening machine for straightening the workpiece.

6. The method as claimed in claim 5, wherein the scanning of the toothed region is performed in a tactile and/or non-contacting and/or optical manner.

7. The method as claimed in claim 5, wherein the measured items of data are transmitted to a common control installation or to a common controlling and regulating installation, whereby the common controlling/regulating installation controls/regulates the measuring of the workpiece and the straightening of the workpiece.

8. The method as claimed in claim 5, wherein measuring of the toothed region of a second workpiece is performed while a first, previously measured, workpiece is being straightened.

9. The method as claimed in claim 5, wherein a measuring installation for measuring toothings is integrated in a conveying section of a conveying installation of the straightening machine that is to be provided ahead of the straightening machine.

10. The method as claimed in claim 1, comprising a measuring installation having a measuring head that is movable on the measuring installation; having a stop region that is disposed on the measuring head; and having a measuring sensor that is disposed on the measuring head and movable on the measuring head; wherein the stop region during the measuring of the toothed region of the workpiece is guided along the peaks of the teeth of the toothed region; wherein the measuring sensor during the guiding of the stop region of the measuring head along the contour of the toothing is guided up and down; and wherein the position, in particular the height, of the measuring sensor, and/or the position, in particular the height of the measuring head, is detected in a sensory manner.

11. A measuring device, in particular for carrying out the method as claimed in claim 1, having at least one measuring head that is repositionable along a slide guide parallel with an elongate workpiece to be straightened, said workpiece having a toothed region; comprising means for ascertaining the height differentials between the tooth heads that form the peaks of the teeth of a toothed region and the neighboring locations of the surfaces of the workpiece that form a reference plane on or at or in the region of the toothing, however at least more or less close to the in particular active reference circle that lies between the peaks and troughs of the teeth; and means for ascertaining deviations from an ideally straight workpiece.

12. The measuring device as claimed in claim 11, wherein the means for ascertaining the height differentials, and the means for ascertaining deviations are combined in a functional group or so as to form the latter.

13. The measuring device as claimed in claim 11, comprising a height-adjustable stop region which is capable of being placed onto the peak of the teeth of the toothed region and/or is capable of being guided along the peaks; and comprising a height-adjustable measuring sensor which is disposed on the measuring device so as to be movable relative to the height of the stop region and which is capable of being guided along the contour of the toothed region.

14. A straightening machine for straightening radial run-out faults or linearity faults on elongate workpieces having at least one toothed region, such as of toothed shafts or toothed racks, in particular for carrying out the method as claimed in claim 1, wherein said straightening machine comprises a measuring installation for measuring toothings, said measuring installation being integrated in a conveying section of a conveying installation that is provided ahead of the straightening machine.

15. A straightening system comprising a straightening machine for straightening radial run-out faults or linearity faults on an elongate workpiece having at least one toothed region, such as of a toothed shaft or a toothed rack, in particular comprising a straightening machine as claimed in claim 15, and comprising a measuring device having a measuring head for measuring the toothing of the toothed region, wherein the straightening machine and the measuring device are connected to one another by a data line.

16. The straightening machine or the straightening system as claimed in claim 14, wherein the measuring of the toothed region of the workpiece is performed at points, in particular at a plurality of measuring positions, or wherein the measuring of the toothed region of the workpiece is performed continuously across the length of the toothed region.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0023] In the drawing:

[0024] FIG. 1 shows a straightening system for toothed shafts or toothed racks according to the prior art (EP 2 055 403 A2), having a non-contacting measuring of toothings;

[0025] FIG. 2 shows a measuring installation according to the invention for ascertaining the height differentials between the tooth heads forming the peaks of the teeth of a toothed region and the neighboring locations of the surfaces of the not yet straightened workpiece that form a reference plane, more or less close to the active reference circle of the toothing that lies between the peaks and troughs of the teeth, and/or for ascertaining deviations from the ideally straight workpiece;

[0026] FIG. 3 shows a toothed rack according to FIG. 2 in a detailed illustration; and

[0027] FIG. 4 shows a straightening machine having a measuring installation according to FIG. 2 (schematic, block diagram).

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0028] A measuring installation 20 can be derived from FIG. 2. A measurement of differences in tooth head dimensions in relation to spherical dimensions can be performed by way of the measuring installation. As can be seen from FIG. 2 and the following description thereof, a measuring installation 20 illustrated in an exemplary manner has both means for ascertaining the height differentials between the teeth heads that form the peaks of the tooth of a toothed region and the neighboring locations of the surfaces of the workpiece that form a reference plane on or at or in the region, at least however more or less close to the, in particular active, reference circle or pitch circle, respectively, of the toothing thereof that lies between the peaks and troughs of the teeth, and means for ascertaining deviations from an ideally straight workpiece 30 such as the toothed rack illustrated. Both means can be combined so as to form a functional group or so as to be in a latter. Said means are provided by an installation that serves for comparing the actual measured items of data in the reference plane and stored nominal data. The toothed region 30A or the entire workpiece 30 is initially aligned axially and in terms of the angular position thereof, wherein the teeth 31 point in the direction of a measuring head 21 of the measuring installation 20. The alignment means 28A, 28B illustrated can be but do not have to be machine tool centers known per se.

[0029] In order for the difference in terms of dimension to be detected, the measuring installation 20 has a slide guide 22 along which a driven slide 27 is repositionable. The slide 27 can thus be moved across the toothed length and/or across the entire workpiece length, for example to the positions x1, x2, or x3. The slide 27 also has a further slide guide 23 for a slide 24, said slide guide 23 preferably being disposed so as to be orthogonal to the slide guide 22. The measuring head 21 that is connected to said slide guide 23 is thus capable of being lowered from an upper resting position in the direction of the teeth. The stop region 32 bears on the teeth in the case of the lowered measuring head 21. The measuring head 21 is provided with a mechanically or preferably electrically effective, optionally retractable and deployable, in particular spring-loaded, measuring sensor 25 having a ball caliper 26 fastened thereto. The measuring sensor 25 completes an up-and-down movement when the stop region 32, bearing on the tooth heads of the teeth, is moved along the longitudinal extent of the workpiece.

[0030] A measuring procedure can comprise the following sequence of functions having the functional steps hereunder: [0031] The preferably horizontally repositionable slide 27 is moved across the tooth gap/s to be measured (for example, x1, x2, or x3). [0032] The preferably vertically repositionable slide 24 travels downward until the ball caliper 26 comes to sit on the respective tooth head 31A of the toothed rack. [0033] The ball caliper 26 that is fastened to the measuring sensor 25 is displaced (upward in the exemplary embodiment) when coming to sit on the tooth head 31A and on each fundamentally arbitrary region of the tooth 31 lying therebeside. The displacement paths can be detected by the measuring head 21. The differences in terms of dimension (height differentials) of the elevated locations of the tooth heads in relation to the elevated locations of neighboring tooth surfaces lying in the reference plane are ascertained by way of said measured values. [0034] The procedure is repeated for a plurality of, preferably all, tooth gaps to be measured. [0035] The associated differential values are also transmitted as the workpiece 30 is transferred to the straightening machine, for example according to FIG. 4, such that the actual straightening procedure can then be performed in a manner relative to the dimension of the tooth head. [0036] The straightening machine controller by way of the known difference in terms of dimension can determine and display the spherical dimensions from the measured tooth head dimensions and the ascertained differences in terms of dimension achieved after the straightening procedure.

[0037] FIG. 3 shows an enlarged fragment of the toothed region 30A from FIG. 2. Illustrated is the spacing dimension h2 of the tooth head 31A from the workpiece centerline M, on the one hand, and the ball immersion dimension h1, on the other hand. This is understood to mean the spacing of a ball center from the workpiece center. The ball diameter is chosen such that said ball is a tangent to the tooth flanks (reference plane) approximately on the reference circle. The accuracy of the dimension h1 is decisive for the precise functioning of the workpiece, for instance in the case of the toothed rack, for example in a vehicle steering mechanism.

[0038] The measuring can preferably be performed outside the straightening machine. In order for the set of issues in terms of the increase of the cycle time of the straightening process by the spherical dimension detection to be circumvented, a relocation of the measuring of the toothing from the straightening machine 40, for example according to FIG. 2, can be provided such as can be seen, for example, in the block diagram according to FIG. 4, on account of which the measuring installation 20 is disposed upstream of the straightening machine 40. The differences in terms of dimension of tooth head dimension h2 minus spherical dimension h1 ascertained by the measuring installation 20 are fed to the controller of the straightening machine 40, for instance by way of a data line. The straightening machine 40 in this instance operates only in terms of the tooth heads 31A but by way of the now known difference of tooth head dimension minus spherical dimension can measure and straighten indirectly according to the spherical dimension without losses in terms of cycle times being created. The instrumental arrangement of the straightening machine 40 and of the measuring installation 20 (disposed upstream or outside) forms a straightening system wherein straightening and measuring form processes that run in a mutually independent manner. The measuring station is placed according to the invention ahead of the straightening system. The results of the measuring station are incorporated in the sequence of the straightening process and, in as far as expedient, are documented together with the items of data detected in the straightening process.

LIST OF REFERENCE SIGNS

[0039] 1 Laser sensor [0040] 2 Workpiece [0041] 3 Straightening hammer repositionable parallel with the rotation axis of the workpiece [0042] 4 Straightening anvil [0043] 5 Center [0044] 6 Straightening table [0045] ML Measuring light beam [0046] 20 Measuring installation [0047] 21 Measuring head [0048] 22 Slide guide [0049] 23 Slide guide [0050] 24 Slide [0051] 25 Measuring sensor [0052] 26 Ball caliper [0053] 27 Slide [0054] 28A Alignment means [0055] 28B Alignment means [0056] 30 Workpiece [0057] 30A Toothed region [0058] 31 Tooth [0059] 31A Tooth head [0060] 32 Stop region [0061] 40 Straightening machine [0062] 41 Conveying installation [0063] 42 Controller [0064] h1 Spherical dimension [0065] h2 Tooth head dimension [0066] M Workpiece centerline [0067] x1 Position [0068] x2 Position [0069] x3 Position