Method and device for deburring a workpiece having internal teeth

Abstract

A workpiece (2), i.e. a gear with internal teeth, is deburred using a deburring tool (1) having two cutting plates (12, 13), wherein the workpiece (2) is first rotated in a first rotational direction, wherein a tooth flank (7) of an internal tooth (3) of the workpiece (2) is deburred by means of the first cutting plate (12), and another tooth flank (6) of the internal tooth (3) is deburred by means of the second cutting plate (13) in a later machining stage, in which the workpiece (2) is rotated in the opposite direction.

Description

Technical Field

[0001] The invention relates to a method for deburring a workpiece having an internal toothing and also to a deburring tool suitable for carrying out the method. Background Art

[0002] The toothing of the workpiece can be efficiently produced, for example, by hob peeling. In this case, reference is made by way of example to the documents DE 10 2014 008 475 A1, EP 2 537 615 A1 and WO 2015 / 036098 A2. The last-mentioned document relates in particular to cooling during hob peeling.

[0003] Hob peeling is also fundamentally suitable for producing chamfers on workpieces. Details of corresponding machining methods are disclosed in DE 10 2017 204 891 A1 and DE 10 2014 218 082 A1.

[0004] As with other machining processes, hob stripping can cause burrs on the workpiece that must be removed in a subsequent machining step. For possible designs of devices for deburring, reference is made to documents DE 36 08 458 C1, DE 103 09116 A1 and DE 10 2014 010 824 A1. Summary of the invention

[0005] The object of the invention is to design the deburring of workpieces with internal teeth produced by hobbing in a particularly rational and reliable manner.

[0006] According to the invention, this object is achieved by a method for deburring a workpiece with an internal toothing having the features of claim 1. Furthermore, this object is achieved by a device having the features of claim 5. The configurations and advantages of the invention described below in relation to the device, i.e. the deburring tool, also apply mutatis mutandis to the deburring process and vice versa.

[0007] The deburring process includes the following steps:

[0008] - providing a workpiece with an axis of symmetry having an internal toothing produced by hobbing,

[0009] - providing a deburring tool having at least a first cutting plate and a second cutting plate, wherein the cutting plates are diametrically opposed with respect to a central axis of the deburring tool,

[0010] - rotating the workpiece in a first rotational direction, wherein the tooth flanks of the internal teeth are deburred by means of a deburring tool by means of a first cutting plate, the deburring tool not rotating during this process and the central axis of the deburring tool being arranged parallel to the axis of symmetry of the workpiece,

[0011] - displacing the deburring tool relative to the workpiece while maintaining parallelism between the axis of symmetry and the central axis in such a way that none of the cutting plates touches the workpiece,

[0012] - Reverse the direction of rotation of the workpiece,

[0013] - further displacing the deburring tool relative to the workpiece while maintaining parallelism between the axis of symmetry and the central axis and deburring the tooth flanks of the internal teeth with the deburring tool by means of the second cutting plate, the deburring tool not rotating during this process.

[0014] The terms "axis of symmetry" (always in relation to the workpiece) and "center axis" (always in relation to the deburring tool) are chosen merely for linguistic distinction purposes and do not imply any information about the difference between the symmetry of the workpiece on the one hand and the symmetry of the tool on the other hand.

[0015] In addition to the internal teeth, the workpiece may also optionally have external teeth. The production and possible deburring of such a toothing on the outer circumferential surface of the entire annular workpiece may be carried out in any conventional manner, wherein in this case no deburring tool is used.

[0016] In a preferred method, both the first cutting plate and the second cutting plate deburr the end face of the internal tooth of the workpiece. The shapes of the two cutting plates are preferably exactly the same. The cutting plates are usually made of, for example, carbide. In this case, reference is made to document DE 20 2011 050 704 U1 by way of example.

[0017] The workpiece for deburring has a T-shaped base profile formed by a shaft aligned along a central axis and a cutting plate holding portion arranged transversely to the shaft. Two cutting plates arranged diametrically opposite to each other with respect to the central axis are fixed to the cutting plate holding portion forming a T-shaped crosspiece, wherein the cutting edges of the cutting plates are arranged for deburring facing the shaft.

[0018] Throughout the method carried out successively with two cutting plates, the shaft of the deburring tool preferably remains arranged in the cavity of the workpiece enclosed by the internal toothing.

[0019] The cutting edges of the cutting plate that engage with the workpiece during successive deburring operations are aligned approximately along the same straight line. For example, an angle of at least 165° and at most 178° is formed between the cutting edges. Smaller angles or larger angles, in particular an angle of 180°, formed between the cutting edges are also possible. The cutting plate is, for example, an indexable insert that is welded, clamped or screwed onto the base body of the deburring tool.

[0020] Between machining the workpiece with internal teeth with the first cutting plate and machining the workpiece with the second cutting plate, an idle stroke of the hob peeling can be performed. Generally speaking, hob peeling can involve multiple passes first as roughing and then as finishing.

[0021] Compared to common milling cutters, such as the one described in DE 196 24 342 C1, in which several cutting plates are arranged in the same circumferential direction on the circumference of the tool tip, in the deburring tool according to the present application, which replaces a turning tool, the cutting plates are oriented in opposite circumferential directions. This means that, for example, when observing the deburring tool, the tops of both cutting plates are visible. In particular, the upper surfaces of the two cutting plates are located in a common plane. One of the cutting plates is used, for example, to deburr all left-hand flanks of an internal tooth, while the other cutting plate is specifically provided for deburring the right-hand flanks. After the double flank deburring performed with the deburring tool, no additional operations are required in typical applications to mechanically machine the internal teeth.

[0022] In summary, a workpiece, namely a gear with internal teeth, is deburred using a non-rotating deburring tool with two cutting plates, wherein the workpiece is initially rotated in a first direction of rotation, wherein a tooth flank of the internal teeth of the workpiece is deburred by means of the first cutting plate, and another tooth flank of the internal teeth is deburred by means of the second cutting plate in a later machining stage, in which the workpiece is rotated in the opposite direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the following, exemplary embodiments of the present invention are described in more detail with the aid of the accompanying drawings. In the accompanying drawings:

[0024] Figure 1 shows a cross-sectional view of a workpiece with internal teeth,

[0025] Figure 2 shows a workpiece during a first deburring process performed with a deburring tool,

[0026] Figure 3 shows a workpiece during a second deburring process performed with a deburring tool,

[0027] Figure 4 A perspective view of a workpiece with internal teeth is shown,

[0028] Figure 5 The toothing of an internal toothing of a workpiece is shown. DETAILED DESCRIPTION

[0029] exist Figure 2 and Figure 3 In the method shown in the figure, a deburring tool 1 is used, which is also referred to as a tool. Figure 1and Figure 4 The workpiece 2 shown separately in the figure is machined.

[0030] The machining process starts at Figure 1 In the state shown in , a workpiece 2 is provided, wherein the workpiece 2, i.e. the internal toothing of a gear wheel, designated 3, already exists. The internal toothing 3 was previously produced in a manner known per se by hobbing. In addition, the workpiece 2 has an external toothing 4, which is not machined in the method described with reference to the drawings.

[0031] In this case, the internal toothing 3 is designed as a helical toothing, the individual teeth of which are designated 5. Each toothing 5 has two side faces 6, 7, i.e. tooth flanks, which adjoin the end faces of the gear wheel 2 designated S1, S2. During hob peeling, the workpiece 2 is machined in the direction from the first end face S1 to the second end face S2. Roller peeling involves roughing in multiple passes, followed by finishing in one or two passes. The machining direction BR is in Figure 1 At the tool outlet WA, ie at the second end face S2, the result of the hob stripping is burrs on the tooth flanks 6, 7 and on the edge 8 of the tooth base designated 17.

[0032] The tool 1 for deburring the toothed part 5 is described as follows. Figure 2 , Figure 3 and Figure 5 The T-shape shown in FIG. 1 has a shaft 9 and a T-shaped crosspiece 10 adjoining the shaft and serving as a cutting board holding portion. A constriction 11 can be seen between the shaft 9 and the cutting board holding portion 10. The shaft 9 has a central axis M, which is oriented at Figure 2 and Figure 3 In the arrangement shown in FIG. 1 , the axis 9 is aligned parallel to the axis of symmetry, designated S, of the workpiece 2. In this arrangement, the shaft 9 is located in a cavity enclosed by the internal toothing 3. The end face S2 of the workpiece 2 to be machined with the tool 1 thus represents the back side of the workpiece, viewed from the not shown holder of the shaft 9.

[0033] Two cutting plates 12, 13, i.e. two indexable inserts, are attached to the T-shaped crosspiece 10 of the tool 1 by means of screws 14. The cutting plates 12, 13 are designed to be mirror-symmetrical to each other with respect to a plane passing through the central axis M. This symmetry also applies to any clamping element. Each cutting plate 12, 13 has a cutting edge 15, 16 to be used in the method. An angle α is formed between each cutting edge 15, 16 and a straight line parallel to the central axis M, such as Figure 5 In the exemplary embodiment, the angle α corresponds to 87.2°. Thus, in this case, an angle (2×α) of 174.4° is formed between the two cutting edges 15 , 16 , which is provided for machining the end face of the workpiece 2 .

[0034] When deburring the workpiece 2, first use the cutting edge 15 of the cutting plate 12, such as Figure 2 As shown in . The workpiece 2 rotates counterclockwise. The tool 1 does not rotate. This process mainly removes burrs located on the tooth surface 7.

[0035] After this step is completed, an idle stroke of the hob peeling is performed, which is not shown in the figure. The tool 1 then moves to Figure 3 , wherein the angular orientation of the tool 1 relative to the orientation of the T-shaped crosspiece 9 remains unchanged. In the exemplary embodiment shown, this means that the cutting plate 12 remains unchanged above the center axis M and the cutting plate 13 remains unchanged below the center axis M. Of course, the orientation of the axes M, S in space is arbitrary, wherein the axes M, S are always aligned parallel to each other during deburring. For example, as an alternative to the arrangement of the workpiece 2 and the tool 1 shown, the axes M, S can be aligned vertically.

[0036] exist Figure 3 In the state shown in , the workpiece 2 rotates clockwise, wherein the burrs on the tooth flanks 6 are mainly removed. Usually, no further machining steps, such as brushing, are required for deburring the workpiece 2. Compared with conventional deburring processes, this ensures particularly rational and at the same time efficient machining.

[0037] Description of Reference Numerals

[0038] 1 Deburring tool

[0039] 2 Workpieces with internal teeth

[0040] 3 Internal teeth

[0041] 4 External teeth

[0042] 5 Teeth

[0043] 6 tooth surface

[0044] 7 tooth surface

[0045] 8 Edge

[0046] 9 Axis

[0047] 10 T-shaped crosspiece, cutting board holding part

[0048] 11 Contraction

[0049] 12 Cutting Board

[0050] 13 Cutting Board

[0051] 14 Screws

[0052] 15 Cutting edge

[0053] 16 Cutting edge

[0054] 17 Tooth base

[0055] Alpha Angle

[0056] BR Machining direction

[0057] M Center axis

[0058] S Axis of symmetry

[0059] S1 End Face

[0060] S2 end face

[0061] WA Tools Export

Claims

1. A method for deburring a workpiece (2) with internal teeth, the method comprising the following steps: - providing a workpiece (2) with an axis of symmetry (S) and with an internal toothing (3) produced by hobbing, - providing a deburring tool (1) having a first cutting plate (12) and a second cutting plate (13), the cutting plates (12, 13) being diametrically opposite with respect to a central axis (M) of the deburring tool (1), - rotating the workpiece (2) in a first rotational direction, deburring the tooth flanks of the internal toothing (3) using the deburring tool (1) with the aid of the first cutting plate (12), the deburring tool not rotating during this process, and the center axis (M) of the deburring tool (1) being arranged parallel to the symmetry axis (S) of the workpiece (2), - displacing the deburring tool (1) relative to the workpiece (2) while maintaining parallelism between the axis of symmetry (S) and the central axis (M) in such a way that neither of the cutting plates (12, 13) touches the workpiece (2), - reversing the direction of rotation of the workpiece (2), - The deburring tool (1) is further displaced relative to the workpiece (2) while maintaining parallelism between the axis of symmetry (S) and the center axis (M), and the tooth flanks of the internal teeth (3) are deburred using the deburring tool (1) with the aid of the second cutting plate (13), the deburring tool not rotating during this process.

2. The method according to claim 1, characterized in that The end face of the workpiece (2) is deburred both by means of the first cutting plate (12) and by means of the second cutting plate (13).

3. The method according to claim 2, characterized in that During the entire deburring process performed with the two cutting plates (12, 13), the shaft (9) of the deburring tool (1) remains arranged in the cavity of the workpiece (2) enclosed by the internal toothing (3).

4. The method according to any one of claims 1 to 3, characterized in that An idle stroke of the hob peeling is performed between machining of the workpiece (2) using the first cutting plate (12) and machining of the workpiece (2) using the second cutting plate (13).

5. A tool (1) for deburring a workpiece (2) with internal teeth, the tool having a T-shaped base shape, the T-shaped base shape being formed by a shaft (9) defining a central axis (M) and a cutting plate holding portion (10), the cutting plate holding portion being aligned transversely to the shaft and fastened with two cutting plates (12, 13), the cutting plates being diametrically opposite relative to the central axis (M), the cutting edges (15, 16) of the cutting plates (12, 13) facing the shaft (9).

6. The tool (1) according to claim 5, characterized in that An angle of at least 165° and at most 178° is formed between the cutting edges (15, 16).

7. The tool according to claim 5 or 6, characterized in that The cutting plates (12, 13) are designed as indexable inserts.

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