Rolling tool and method for rolling a profile

Abstract

The invention relates to a rolling tool (10) for rolling a profile, in particular a spline toothing on a workpiece using a rolling disc packet, comprising at least one main disc (24) and an exchangeable disc (26) secured thereon. According to the invention, the exchangeable disc (26) has a phase (40) or a profile depression (42) in the working direction (8). The invention also relates to a method for rolling a profile, in particular a spline toothing on a workpiece.

Description

[0001] The invention relates to a rolling tool and a method for rolling a profile, in particular a spline on a workpiece. STATE OF THE ART

[0002] DE 10 2007 039 959 A1 discloses a rolling machine with incremental round rolling tools and a method for cold rolling longitudinal gears and profiles on a workpiece. Two rolling spindles are mounted parallel to each other on a rolling carriage so that they can be freely positioned in the feed direction toward the workpiece and simultaneously in the axial direction relative to the workpiece. The rolling spindles are driven synchronously by a CNC control system of the profile rolling machine and are advanced in stages to apply the gears to the workpiece in sections.

[0003] It is also known to operate such machines with a constant feed rate, whereby the workpiece is rolled continuously rather than in sections. This process is also known as a pre-rolling or push-through rolling process. Push-through rolling processes are usually used in the production of long profiles and / or on hollow shafts to minimize the pressure on the workpiece. Excessively high pressures can lead to cracking and distortion of the workpiece, which is undesirable.

[0004] However, round rolling tools are not limited to the arrangement and operating conditions described in DE 10 2007 039 959 A1. For example, three or more round rolling tools can be arranged around the workpiece to apply a profile to it, see, for example, DE 803 232 A1.

[0005] WO2019020619 A1 discloses a rolling tool for rolling a profile in a push-through rolling process with a rolling disk which comprises an inlet region for rolling the workpiece, wherein the rolling disk has a chamfer forming the inlet region.

[0006] For chamfering and deburring the front tooth edges of gears, it is also known to assemble circular tools consisting of several roller disks that can be rotated relative to one another, as exemplified by EP 1 270 127 B1. However, the tool described therein is not operated in a feed mode; instead, after radial advance to the workpiece, the profile is rolled axially in a stationary manner.

[0007] The prior art processes mentioned above have the disadvantage that the rolling machines used typically have a short service life, meaning that after a relatively small number of workpieces have been produced, the rolling disks or even the entire machine must be replaced. Due to the complex manufacturing process of the rolling tool profiles by grinding, this usually involves considerable costs. OBJECT OF THE INVENTION

[0008] The invention is based on the object of creating a rolling tool for rolling a profile, in particular a spline on a workpiece, and a corresponding method therefor, which overcome the disadvantages of the prior art. DISCLOSURE OF THE INVENTION

[0009] The object is achieved by a rolling tool and a method for producing, in particular rolling or rolling, a profile, in particular a spline on a workpiece, according to the features of the independent patent claims. Advantageous embodiments are characterized by the features of the subclaims.

[0010] According to a first aspect, a rolling tool for rolling a profile, in particular a spline on a workpiece, comprises a rolling disk assembly having at least one main disk and an interchangeable disk releasably and non-rotatably attached thereto. The interchangeable disk is positioned upstream of the main disk with respect to a working direction.

[0011] The components referred to as discs in the present disclosure can be components of a rolling beam as well as of a round rolling tool.

[0012] For the purposes of the invention, a working direction is identified with the direction of workpiece feed. In the case of a circular tool, the working direction can, but does not necessarily have to, coincide with a main or rotational axis of the disk stack. In the case of a rolling beam, the working direction runs perpendicular to the movement of the rolling beams during the rolling process. In both embodiments, the device is configured to perform a push-through rolling process.

[0013] The interchangeable disc includes an inlet area for rolling the workpiece. When the rolling tool is operated in the rolling machine, the interchangeable disc first encounters the workpiece and is primarily subjected to this stress. This means that most of the forming work is performed by the interchangeable disc. Since this disc is detachably attached to the main disc, it can be easily replaced when it becomes worn. This results in significant material savings, as the main disc and any other existing discs can ideally be reused.

[0014] Furthermore, the interchangeable disc is designed to have a profile depression or chamfer on the front side in the working direction, which forms the lead-in area. The chamfer area is designed so that in this area the profile rises from the front side towards the calibration. In the case of a tooth profile, the teeth become increasingly deeper until they approach the final tooth shape. The profile depression, on the other hand, has a uniform profile depth along the working direction, but is machined at an angle to the working direction, so that the workpiece meshes with the workpiece only gradually along the working direction.

[0015] The invention can be used for rolling both short and long workpieces, particularly for the production of splined shafts, gears, rotor shafts, and the like. The invention is particularly suitable for forming external gear teeth on gear wheels or gear shafts. Helical or spiral gear teeth and the like can also be produced with the tool according to the invention. Furthermore, the workpieces can be solid or hollow. Due to the relatively low pressure on the workpiece, this application is particularly suitable for hollow workpieces and / or long profiles.

[0016] In principle, the profile of the discs can be any desired, for example, serrations or involute teeth can be created on the workpiece.

[0017] The interchangeable disc can be made of the same material as or a different from the main disc. Because the interchangeable disc performs the most work on the workpiece during operation, it may be advantageous to use a higher-quality material for the interchangeable disc than for the main disc, such as carbide. This can save costs in the event of wear, while simultaneously increasing service life. Alternatively, a less expensive material than the main disc can be used. The interchangeable disc and the main disc, or even just the interchangeable disc, can also be coated to optimize material properties.

[0018] Compared to the main disc, the width of the interchangeable disc can be in the range of 2 to 50%, preferably in the range between 5 and 10%.

[0019] A chamfer angle or profile countersink angle in the entry area is preferably as small as possible, since the deformation per feed should be as small as possible. In practice, the angle is preferably between 5° and 35°, more preferably between 10° and 20°, especially approximately 15°. At angles smaller than 5°, the entry area would become too large, leading to high material costs for the tool. When manufacturing components with a large adjacent collar and only a short undercut, the chamfer angle or profile countersink angle in the entry area is often limited in size by the component geometry.

[0020] The rolling disk package, in particular the interchangeable disk and / or the main disk, can have a calibration area which is characterized by a constant profile height, in particular constant tooth height and tooth shape, along the working direction.

[0021] According to the invention, the rolling disk stack, in particular the main disk, has a relief zone, which is preferably characterized by a profile depression along the working direction. In the relief zone, a constant profile depth with a recessed profile at an angle (profile depression) can preferably be provided, but alternatively, a reduction in the profile depth or a change in the profile shape can also be provided, so that the workpiece gradually meshes less with the tool during feed.

[0022] In one embodiment, the relief area is located downstream of the calibration area with respect to the working direction. Alternatively, for example, a first relief area can be provided upstream of the calibration area and a second relief area downstream of the calibration area.

[0023] In a preferred embodiment, the rolling disk assembly also comprises a chamfering disk characterized by a profile elevation along the working direction. In this embodiment, workpieces with a length approximately equal to the length of the main disk can be provided with chamfers for the profile, for example, for the gear teeth. The chamfering of the gear teeth on the workpiece serves, for example, to improve mating capability, for example, in the case of external splines of gear wheels or shafts that are inserted into a hub with counter-toothing.

[0024] The chamfering disk can be detachably attached to the main disk and, in particular, positioned downstream of the main disk in relation to the working direction. A workpiece which is processed in the machine and moved past the tool therefore first comes into contact with the interchangeable disk, then with the main disk and finally with the chamfering disk. Alternatively, the main disk itself can have a chamfering area which, for example, adjoins the calibration area or the relief area, i.e. is positioned downstream of it. One advantage of a separate chamfering disk is that it is easier to manufacture the tool, since manufacturing the calibration, relief and chamfering areas as a single piece is complex. Within a transverse plane, the profile of the main disk and / or the interchangeable disk can be homogeneous, i.e., of the same design. Alternatively, an incremental profile shape can also be provided within the transverse plane.A transverse plane is a plane that is perpendicular to the working direction.

[0025] According to a further aspect, a rolling arrangement comprises at least one, preferably two, three, or four rolling tools as described above, which are preferably arranged in a planetary manner around a rolling region. The rolling arrangement also comprises at least one controller, for example a CNC controller, which is configured to position the rolling tools relative to one another and to enable axial displacement of the workpiece relative to the tools, for example by advancing the workpiece against stationary rolling tools. Alternatively, the controller can axially displace the rolling tools relative to a stationary workpiece.

[0026] In a method for rolling a profile, in particular a spline on a workpiece by means of a rolling tool, in which an axial feed of the workpiece to the rolling tool along a working direction takes place during a forming of the workpiece, e.g. in the case of stationary rolling tools or stationary workpieces, it is provided that the profile is formed in the inlet area, an optional calibration area and the relief area of ​​the rolling tool.

[0027] The method is carried out using the rolling tools described above. The features disclosed with reference to the rolling tool are accordingly also to be understood as disclosed with reference to the method.

[0028] The functional width of the individual zones, especially the inlet zone, can be adjusted as a function of the axial feed rate. For example, the width of a calibration zone can be adjusted to the axial feed rate so that each zone on the workpiece comes into contact with a corresponding counterpart on the calibration zone at least once.

[0029] The feed of the workpiece to the rolling tool along the working direction is preferably a feed movement with a constant or variable feed rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The invention is explained in more detail with reference to the figures. They show: Fig. 1 shows a rolling arrangement with a workpiece arranged therein in plan view, Fig. 2 shows a front view of a rolling tool according to a first embodiment, Fig. 3 shows a sectional view of the rolling tool along AA in Fig. 2, Fig. 4 an enlarged area B from Fig. 3 according to a first embodiment, Fig. 5 an enlarged area B of Fig. 3 according to a second embodiment, Fig. 6 a sectional view corresponding to the illustration in Fig. 3 by a rolling tool according to a further embodiment and Fig. 7 an enlarged area C from Fig. 6 . EMBODIMENTS OF THE INVENTION

[0031] The invention is illustrated and described below using a circular tool as an example. However, the invention is also applicable to rolling bars as rolling tools.

[0032] Fig. 1 shows a rolling arrangement 2 of a rolling machine with two rolling tools 10 arranged parallel and at a distance from one another, in particular round rolling tools, which define a clear width between them for receiving a workpiece 4.

[0033] The rolling machine is designed, for example, for cold rolling profiles 6 such as, as shown, longitudinal gearing of shaft-shaped workpieces 4. The rolling tools 10 are arranged, for example, on computer-controlled, freely positionable rolling carriages. During operation of the rolling machine, the rolling tools 10 are driven in synchronous rotation via a control system (not shown), such as a CNC control system, and are simultaneously advanced towards one another by means of the control system, so that the workpiece 4 comes into contact or engagement with the profile of the rolling tools 10. The control system pushes the workpiece 4 through the rolling tools 10 in a working direction 8, which here coincides, for example, with the main axes 30 of the rolling tools 10. The feed is generated by a relative movement between the workpiece 4 and the rolling tools 10, e.g.by displacing the workpiece 4 relative to stationary rolling tools 10, or by displacing the rolling tools 10 relative to the stationary workpiece 4. The feed can be continuous or variable speed. After rolling, the workpiece 4 has the profile 6. During this process, the workpiece 4 is mounted in a workpiece holder 9, for example, between centering centers.

[0034] Fig. 2 shows a rolling tool 10 according to an embodiment of the invention in a front view. The perspective shows, in the words of the present disclosure, a transverse plane of the rolling tool 10, since the illustrated plane is perpendicular to the main axis 30 of the rolling tool 10. The main axis 30 coincides in many applications with the working direction 8, as described with reference to Figure 1 described.

[0035] The rolling tool 10, in particular a round rolling tool, has a profile region 12 equipped with a tooth profile along its outer circumference. The teeth of the profile region 12 can have any shape, for example, a wedge-shaped, notched, or involute section. In the view shown, the profile region 12 can be homogeneous or inhomogeneous over the circumference of the rolling tool. For example, incremental increases in the teeth over the circumference of the rolling tool 10 are possible. However, it is also possible for the profile to be essentially the same over the circumference, since the tooth shape, height, and / or size of the teeth change along the working direction 8, as will be described in more detail with reference to the other figures.

[0036] The rolling tool 10 comprises a rolling disk package 14, which with reference to Fig. 3described in more detail. In the center of the rolling tool 10 is a mounting opening 16 for receiving a tool spindle (not shown). In this embodiment, the mounting opening 16 is not circular, but rather has two tangential keyways 17, although this is purely exemplary. The drive options for the rolling tool 10 by the tool spindle can be configured in a variety of ways and, for example, include more than two tangential keyways 17 or a keyway connection.

[0037] The rolling tool 10 is preferably installed in a rolling arrangement (not shown), such as with reference to Figure 1 described. For example, 1, 2, 3, or 4 such rolling tools 10 can be provided, which act on the typically round workpiece 4 at different locations.

[0038] The rolling tool 10 shown has a series of fastening elements 18, which are arranged here, for example, regularly at 45° intervals from one another at the same distance around the main axis 30. By means of the fastening elements 18, the individual discs of the rolling disc package 14 are fastened to one another in a detachable and rotationally secure manner, which is better Fig. 3 emerges.

[0039] Fig. 3 shows the rolling tool 10 from Fig. 2 along section AA. The profile area 12 in the area B is in the Figures 4 and 5 shown again enlarged.

[0040] The rolling disk assembly 14 comprises a main disk 24 and an interchangeable disk 26 attached thereto, which is positioned upstream of the main disk 24 with respect to the working direction 8. The interchangeable disk 26 is attached to the main disk 24 by means of a clamping disk 28. The diameter of the clamping disk 28 is slightly smaller than the diameter of the main disk 24, so that there is no engagement with the workpiece. b 1 denotes a width of the rolling disk assembly 14. b 2 denotes a working width of the main disk 24 and the interchangeable disk 26 together.

[0041] The fastening elements 18, which are connected with Fig. 2described above are designed here once as a pin 20 and once as a screw 22, for example a cylindrical pin and a cylinder head screw. The expert will expediently select the fastening elements 18 so that the individual disks of the rolling disk package 14 are fastened to one another sufficiently firmly. The anti-twist and anti-displacement devices are designed to be large enough to absorb static and dynamic forces from the work process. The detachability and assembly are determined so that the disks can be easily changed by the user, preferably without special tools. The location and orientation of the fastening elements 18 are ideally coordinated so that the disks can be changed without having to remove the tool 10 from the rolling machine.

[0042] The Fig. 4 and 5 show two different embodiments of rolling tools 10 in the enlarged area B of Fig. 3The embodiments differ in the design of the inlet regions 32 and in the presence / absence of a calibration region 34. The calibration region 34 is characterized by a constant profile along the working direction 8.

[0043] The individual discs of the rolling disc package 14 are in Fig. 4 and 5 not shown. Rather, various embodiments are possible, as described in more detail below.

[0044] Fig. 4 shows the rolling tool 10 with an inlet area 32 of width b 3 , a calibration area 34 of width b 4 and a downstream relief area 36 of width b 5 .

[0045] According to one embodiment, the interchangeable disc can comprise only a portion of the inlet area 32. The main disc then also comprises a portion of the inlet area 32, as well as the calibration area 34 and the relief area 36.

[0046] According to an alternative embodiment, the interchangeable disc can encompass the entire inlet area 32. The main disc then encompasses the calibration area 34 and the relief area 36.

[0047] According to another alternative embodiment, the interchangeable disc can encompass the entire inlet area 32 and part of the calibration area 34. The main disc then encompasses the remaining part of the calibration area 34 and the relief area 36. This embodiment offers assembly advantages because the tooth profiles of the discs are of the same height and of the same design where they meet.

[0048] According to yet another alternative embodiment, the interchangeable disc can encompass the inlet area 32 and the entire calibration area 34. The main disc then encompasses the relief area 36.

[0049] Finally, in yet another embodiment, the interchangeable disc can encompass the inlet area 32, the entire calibration area 34, and part of the relief area 36. The main disc then encompasses the remaining part of the relief area 36.

[0050] In the run-in area 32, the interchangeable disc according to the illustrated embodiment has a chamfer 40 in which the profile depth of the teeth increases in the working direction. The chamfer 40 can, for example, comprise an increase in the profile from 0 to a maximum profile depth. Alternatively, the chamfer 40 does not begin at a zero profile depth, but rather at a run-in depth t 1 , which corresponds, for example, to between one-tenth and half the profile depth in the calibration area. Run-in depth t 1 typically refers to a value that results from half the difference between a pre-turning diameter and a root diameter.

[0051] The increase in profile depth can be linear, as shown. Alternatively, the chamfer 40 can have a radius or steps, or even be designed in the form of a double chamfer.

[0052] In the linear case, the chamfer 40 can be characterized by a chamfer angle w 1, which, as shown in Fig. 4 as a tangent function of the inlet depth t 1 (assuming the profile depth starts at 0) and the width b 3 of the inlet area 32. The chamfer angle w 1 is preferably between 10° and 20°.

[0053] The relief area 36 is located downstream of the calibration area 34 with respect to the working direction 8 and is characterized by a profile depression. Various embodiments known from the prior art are possible. Typically, the profile is machined at a relief angle w 3 . The relief angle w 3 is preferably between 0° 10' and 1°.

[0054] Fig. 5shows an alternative embodiment with inlet area 32 and relief area 36, ​​i.e. without calibration area 34. A significant difference of the embodiment according to Fig. 5 compared to the embodiment according to Fig. 4 is the design of the inlet area 32. In Fig. 5 The inlet area 32 is formed by a profile depression 42. In the profile depression 42, the profile depth t 2 remains constant across the width b 3 , but is machined with a first profile depression angle w 2 to the working direction. The area is therefore conical compared to the calibration area 34. The first profile depression angle w 2 is preferably between 10° and 20°.

[0055] Fig. 6 shows a rolling tool 10 according to a further embodiment of the invention. The illustration in Fig. 6 is analog Fig. 3selected, whereby only the upper part of the rolling tool 10 was shown in section. The rolling tool 10 comprises a profile area 12, which is enlarged with surroundings C in Fig. 7 is shown.

[0056] The rolling disk package 14 comprises in the embodiment according to Fig. 6 and Fig. 7 In addition to the main disc 24, the interchangeable disc 26, and the clamping disc 28, there is also a chamfering disc 44, which is arranged downstream of the main disc 24 with respect to the working direction 8. The workpiece 4 is thus first formed by the interchangeable disc 26, then by the main disc 24, and finally by the chamfering disc 44.

[0057] Fig. 7 shows the area C in an enlarged view. In contrast to the illustrations according to Fig. 4 and 5Here, the main disk 24, the interchangeable disk 26, and the chamfering disk 44 are shown in relation to the functional areas. The interchangeable disk 26 here, for example, exclusively comprises the inlet area 32 and no parts of the calibration area 34 or relief area 36. The main disk 24 here, purely for example, exclusively comprises a relief area 36 and also no calibration area 34. Other embodiments as described above are of course possible.

[0058] In working direction 8, after the main disc 24, the chamfering disc 44 follows, with an inclined profile and a second profile countersink angle w 4 . The first profile countersink angle w 2 and the second profile countersink angle w 4 can be the same or different. Typically, the profile countersink angles w 2 and w 4 are different, since the second profile countersink angle w 4 is determined by the component geometry. For example, the second profile countersink angle w 4 is between 2° and 10°.

[0059] The Fig. 7The rolling tool 10 shown is specially designed for workpieces 4 whose usable profile length or tooth length corresponds approximately to the width b 12 of the main disk 24. During operation, the workpiece 4 is rolled through the inlet area 32, then passes through the calibration area (not shown) and the relief area 36 of the main disk 24, if applicable, and is then guided over a portion of the width b 14 of the chamfering disk 44. The chamfering disk 44 creates a chamfer of the profile on the workpiece 4. LIST OF REFERENCE SYMBOLS

[0060] 2Rolling arrangement 4Workpiece 6Profile 8Working direction 9Workpiece holder 10Rolling tool 12Profile area 14Rolling disk package 16Mounting opening 17Tangential keyway 18Fastener 20Pin 22Screw 24Main disk 26Change disk 28Clamping disk 30Main axis 32Inlet area 34Calibration area 36Relief area 40Chamfer 42Profile depression 44Chamfering disk b 1 Width of rolling disk package b 2 Working width b 3 Width of inlet area b 4 Width of calibration area b 5 Width of relief area b 10 Width of changeable disk b 12 Width of main disk b 14 Width of chamfering disk t 1 Inlet depth t 2 Profile depth w 1 Chamfering angle w 2 First profile depression angle w 3 Relief angle w 4 Second profile depression angle

Claims

1. Rolling tool (10) for rolling a profile (6) in a push-through rolling process, in particular a plug-in toothing on a workpiece (4), having a rolling disc packet (14) which comprises at least one main disc (24) and a replaceable disc (26) attached thereto, the replaceable disc (26) being upstream from the main disc (24) in a working direction (8) identified with a workpiece advancement, wherein the replaceable disc (26) is made from the same material as or a different material from the main disc (24) and comprises an entry region (32) for rolling the workpiece (4), wherein the replaceable disc (26) has a chamfer (40) or profile lowering (42) forming the entry region (32), and wherein the rolling disc packet (14) has a relief region (36).

2. Rolling tool (10) according to claim 1, characterised in that the replaceable disc (26) is made from a hard metal.

3. Rolling tool (10) according to either of the preceding claims, characterised in that a first chamfer approach angle (w1) or a profile lowering angle (w2) in the entry region (32) is between 5° and 35°, preferably between 10° and 20°, in particular approximately 15°.

4. Rolling tool (10) according to any of the preceding claims, characterised in that the rolling disc packet (14) has a calibration region (34) characterised by a constant profile height along the working direction (8).

5. Rolling tool (10) according to any of the preceding claims, characterised in that the main disc (24) has the relief region (36).

6. Rolling tool (10) according to any of the preceding claims, characterised in that the rolling disc packet (14) comprises a chamfer disc (44) which is characterised by a profile elevation along the working direction (8) and which is downstream from the main disc (24) in terms of the working direction (8).

7. Rolling tool (10) according to any of the preceding claims, characterised in that profiles of the main disc (24) and / or replaceable disc (26) are formed identically within a transverse plane.

8. Rolling arrangement (2), having at least one, preferably two, three or four, identically formed rolling tools (10) formed according to any of the preceding claims, and having a control system set up to deliver the rolling tools (10) to one another and to enable axial displacement of the workpiece (4) with respect to the tools (10).

9. Method for rolling a profile (6), in particular a plug-in toothing on a workpiece (4) by means of a rolling tool (10) according to any of preceding claims 1 to 7, wherein, during a deformation of the workpiece (4), the workpiece (4) is delivered axially to the rolling tool (10) along a working direction (8) identified with a workpiece advancement, characterised in that the profile (6) is deformed in the entry region (32), an optional calibration region (34) and the relief region (36) of the rolling tool (10).

10. Method according to claim 9, wherein the delivery of the workpiece (4) to the rolling tool (10) along the working direction (8) is an advancement movement of constant or variable advancement speed.

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