APPARATUS AND METHOD FOR PROFILING WORKPIECES BY COLD FORMING

Abstract

A workpiece executes a rotation movement about a longitudinal axis and is machined by a tool in a multitude of reshaping engagements, in which an active region of the tool comes into contact with the machining region. The tool is held by a tool holder. The tool holder is mounted in an orbiting body so as to be rotatable about a rotation axis and is driven to carry out a rotating movement about the rotation axis, and is driven to carry out an orbiting movement by the orbiting body. Rotation movement of the workpiece is synchronised with the orbiting movement of the tool holder and the rotating movement of the first tool holder is synchronised with the orbiting movement of the tool holder.

Claims

1. A method for manufacturing a profile body having a profiling, by way of cold reshaping a workpiece comprising a longitudinal axis and, in a machining region, an outer surface, wherein the profiling is to be produced in the outer surface, wherein the workpiece executes a rotation movement about the longitudinal axis and is machined by a first tool in a multitude of reshaping engagements which are carried out successively, wherein in each of the reshaping engagements, an active region of the first tool comes into contact with the machining region, wherein the first tool is held by a first tool holder, and wherein the first tool holder: is mounted in an orbiting body, so as to be rotatable about a rotation axis of the first tool holder, and is driven to carry out a rotating movement about the rotation axis wherein the term azimuthal(ly) which is used hereinafter is defined by the rotation axis; and is driven by the orbiting body to carry out an orbiting movement; and wherein the rotation movement of the workpiece is synchronised with the orbiting movement of the first tool holder; and the rotating movement of the first tool holder is synchronised with the orbiting movement of the first tool holder.

2. The method according to claim 1, wherein the rotation movement of the workpiece is synchronised with the orbiting movement of the first tool holder in such a way that several of the reshaping engagements take place at each one of various different positions distributed over a periphery of the workpiece, and the rotating movement of the first tool holder is synchronised with the orbiting movement of the first tool holder in such a way that the first tool runs through the same azimuthal orientations in each of the reshaping engagements.

3. The method according to claim 1, wherein the orbiting body carries out a rotation along an orbiting body axis, and wherein the orbiting body axis and the rotation axis are aligned parallel to one another.

4. The method according to claim 1, wherein the first tool holder describes a trajectory which results from a superposition of the orbiting movement with a feed movement which is directed radially towards the longitudinal axis.

5. The method according to claim 1, wherein the active region of the first tool, when the first tool is held by the first tool holder, extends azimuthally over a sector only.

6. The method according to claim 1, wherein the workpiece comprises a profiling delimitation structure adjacent the machining region, and wherein the active region in each of the reshaping engagements comes into contact with the machining region right up to the profiling delimitation structure.

7. The method according to claim 1, wherein the rotating movement of the tool holder is synchronised with the orbiting movement of the first tool holder by way of a planetary gear.

8. The method according to claim 7, wherein the planetary gear comprises a ring gear and a planet gear running in the ring gear, wherein the planet gear is part of the and executes the rotating movement together with the first tool holder.

9. The method according to claim 1, wherein the workpiece is simultaneously machined by a second tool in a multitude of reshaping engagements-, wherein in each of the reshaping engagements an active region of the second tool comes into contact with the machining region, in particular wherein each of the successively carried out reshaping engagements of the second tool takes place at a position of the tool which with respect to the longitudinal axis lies opposite the position of the workpiece, at which simultaneously a reshaping engagement of the first tool takes place.

10. The method according to claim 1, wherein the workpiece is additionally machined by a further tool in a multitude of reshaping engagements which are carried out successively, wherein in each of the reshaping engagements an active region of the further tool comes into contact with the machining region, in particular wherein a tool holder holding the further tool carries out the same orbiting movement as the already mentioned tool holder, and wherein this tool holder is identical to the already mentioned tool holder or is different therefrom.

11. The method according to claim 10, wherein the further tool is held by the same tool holder as the first tool, in particular wherein the active regions of the two tools are azimuthally distanced from one another.

12. The method according to claim 10, wherein a second tool holder is provided which is different from the first tool holder and by way of which the further tool is held, wherein the orbiting movements of the first and the second tool holder describe one and the same orbiting path.

13. An apparatus for manufacturing a profile body having a profiling, by way of cold reshaping a workpiece, wherein the apparatus comprises: a workpiece holder which is rotatable about its longitudinal axis, for holding the workpiece; a drive device for producing a rotation movement of the workpiece holder about the longitudinal axis; an orbiting body; a first tool holder for holding a first tool, wherein the tool holder is mounted in the orbiting body, so as to be rotatable about a rotation axis of the tool holder; a drive device for producing a rotating movement of the first tool holder about its rotation axis; a drive device for producing a movement of the orbiting body by way of which the first tool holder is drivable to carry out an orbiting movement; a first synchronisation device for synchronising the rotation movement of the workpiece holder with the orbiting movement of the first tool holder; and a second synchronisation device for synchronising the rotating movement of the first tool holder with the orbiting movement of the first tool holder.

14. The apparatus according to claim 13, comprising a planetary gear which is a constituent of the second synchronisation device and/or is a constituent of the drive device for producing a rotating movement of the first tool holder about the rotation axis.

15. The apparatus according to claim 13, wherein the orbiting body is mounted in a profiling head, and wherein the apparatus comprises a drive for a movement of the profiling head towards the longitudinal axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0125] The subject-matter of the invention is hereinafter explained in more detail by way of embodiment examples and the accompanying drawings. Schematically shown are:

[0126] FIG. 1 an apparatus for carrying out the method for the profiling of a workpiece by cold reshaping;

[0127] FIGS. 2A-2D successive phases of the method;

[0128] FIG. 3 a tool holder with a tool, in a section through its rotation axis;

[0129] FIG. 4 a detail of the planetary gear with a planet gear, according to FIG. 3;

[0130] FIG. 5 a detail of an apparatus with two profiling heads, with a symbolised radial feed;

[0131] FIG. 6A an orbiting path of a tool holder;

[0132] FIG. 6B a radial feed movement, symbolically;

[0133] FIG. 6C a trajectory of a tool holder, as a superposition of an orbiting movement and a radial feed;

[0134] FIG. 7 a detail of an apparatus with two profiling heads which each include three tool holders each with two tools;

[0135] FIG. 8 a profile body with an outwardly projecting shoulder;

[0136] FIG. 9 a detail of a workpiece on an outer-profiled mandrel, in a section perpendicular to the longitudinal axis;

[0137] FIG. 10 a workpiece with a conical machining region, in a section which includes the longitudinal axis;

[0138] FIG. 11 a workpiece with a polygonal outer surface, in a section perpendicular to the longitudinal axis;

[0139] FIG. 12 a workpiece or a profile body with two axially distanced, radially outwardly directed profile delimitation structures, between which a profiling has been produced;

[0140] FIG. 13 a workpiece or a profile body with two axially distanced radially inwardly and radially outwardly directed profile delimitation structures, between which a profiling has been produced;

[0141] FIG. 14 a workpiece or a profile body without profiling delimitation structures;

[0142] FIG. 15 a workpiece with non-rotationally symmetrical profiling delimitation structure, in a section perpendicular to the longitudinal axis;

[0143] FIG. 16 a workpiece or a profile body with azimuthally non-uniformly distributed profile gaps, in a section perpendicular to the longitudinal axis.

DETAILED DESCRIPTION OF THE INVENTION

[0144] Parts which are not essential to some extent are not represented, for a better understanding of the invention. The described embodiment examples are exemplary of the subject-matter of the invention or serve for its explanation and have no limiting effect.

[0145] FIG. 1 shows an apparatus 100 for carrying out the method for the cold reshaping profiling of a workpiece 1. The workpiece 1 is held is held in a workpiece holder 10 that is represented symbolically in FIG. 1 and has a longitudinal axis Z, which is simultaneously also a longitudinal axis of the workpiece 1.

[0146] In the represented example, the workpiece 1 has a machining region 11 that is rotationally symmetrical with respect to the longitudinal axis Z, is with an outer surface 11a, is designed by way of example in a cylindrical manner and in which a profiling is to be produced and onto which a second region 12 connects, in which second region the workpiece 1 has a larger diameter than the machining region 11. By way of this, a profiling delimitation structure, which is designed as a workpiece shoulder 13, is formed between the regions 11 and 12.

[0147] An orbiting body 8, which is represented symbolically in FIG. 1, is further provided, the orbiting body executing a movement R8′, specifically in the represented example by way of it rotating about an orbiting body axis, which is not represented in FIG. 1 and thus executing a rotation R8′. A tool holder 5, which, on account of the movement R8′ of the orbiting body 8, executes an orbiting movement R8 along the orbiting path U, is mounted in the orbiting body 8.

[0148] The tool holder 5 includes a rotation axis W, about which the one rotating movement R5 is executed. This rotating movement R5 can be produced for example directly by a drive (rotation drive) or however be derived from the movement R8′ of the orbiting body 8, for example in a mechanical manner, for example by way of a planetary gear as is described in yet more detail hereinafter.

[0149] The tool holder 5 holds at least one tool 2 that includes an active region 21, in which it comes into cold reshaping contact with the workpiece 1, and specifically by way of it executing a movement which is yet described in more detail hereinafter, during an engagement with the workpiece 1, wherein this movement can be an at least partial rolling movement and can be composed for example of a rolling movement (of the active region on the machining region) and of a sliding movement (of the tool on the workpiece).

[0150] Profile gaps can be produced in the workpiece 1 by way of the tool 2, wherein the tool 2 carries out a multitude of engagements per profile gap.

[0151] In order for the tool 1 to be able to engage with the workpiece 1 at different positions which are distributed over the periphery of the workpiece 1, the workpiece 1 is drivable about the longitudinal axis Z to carry out a rotation movement R1 by way of the workpiece holder 10, in particular wherein the rotation movement R1 can be an intermittent rotation, so that the tool engagement can take place in a phase of the rotation standstill of the workpiece 1.

[0152] Interactions for the purpose of the drive are represented in FIG. 1 by dashed lines, and interactions for the purpose of the synchronisation (which can be realised mechanically and/or electronically) are represented by thickly dotted lines.

[0153] A drive device A1 for producing a rotation movement R1 of the workpiece holders 10 is provided, for example a torque motor or other rotation drive as well as a drive device A8 for producing the movement R8′ of the orbiting body 8. The drive device A8 can include for example a drive shaft.

[0154] Yet a further drive device A5 for producing a rotating movement R5 of the tool holder 5 about is rotation axis W, as already specified above, is yet also provided.

[0155] The rotation axis W is aligned parallel to the orbiting body axis. The orbiting movement R8 of the tool holder takes place in a plane, to which the axes are perpendicular. The longitudinal axis is aligned parallel to this plane.

[0156] In order for the tool engagements to take place where profile gaps are to be produced, the workpiece rotation R1 and the orbiting movement R8 are synchronised with one another by way of a first synchronisation device S1, for example by way of the workpiece rotation R1 and the movement R8′ of the orbiting body 8 being synchronised with one another by way of the first synchronisation device S1.

[0157] For example, the synchronisation can lie in the two movements (R1 and R8 or R8′) having a constant ratio of their revolving times. For example, if only one tool 2 is provided and consecutive engagements of the tool 2 with the workpiece 1 are to be effected in neighbouring profile gaps, then T8/T1=z can be selected, with an orbiting time (period) T8 of the orbiting movement R8 of the tool holder 5 and an orbiting time (period) T1 of the workpiece, wherein z is the number of the profile gaps that are to be produced.

[0158] This synchronisation can be realised for example by way of an electronic synchronisation device S1. Other synchronisation devices, for example mechanical ones, are however basically also conceivable.

[0159] Yet a second synchronisation device S5 is further provided, by way of which the rotating movement R5 of the tool holder 5 and the orbiting movement R8 of the tool holder 5 are synchronised with one another. This can be realised for example by way of an electronic synchronisation device, wherein this can then also be identical to the first synchronisation device S1. In the represented example, this synchronisation is realised mechanically, specifically by way of the already mentioned planetary gear.

[0160] Inasmuch as this is concerned, the drive device A5 can be at least partly identical to the second synchronization device S5, specifically by way of the planetary gear on the one hand producing the rotating movement R5 and on the other hand effecting the synchronisation between the rotation moment R5 and the orbiting movement R8.

[0161] By way of the synchronisation, which is accomplished by way of the second synchronisation device S5, one can succeed in the tool 2 assuming the same azimuthal alignments (with regard to the rotation axis W of the tool holder 5) during each of its engagements with the workpiece 1. This can be advantageous when the workpiece 1, as is represented in FIG. 1, includes an outwardly projecting workpiece shoulder 13 and the profiling is to be created right up to this. This is explained in FIGS. 2A to 2D.

[0162] FIGS. 2A-2D illustrate successive phases of the method. Most reference numerals are already explained above; 23 designates a tool recess or a tool shoulder, 22 designates a free region of the tool 2 and φ designates an azimuthal orientation of the tool, with respect to the rotation axis W, or more precisely the respective azimuthal angle (measured in the anticlockwise direction). As is represented in FIGS. 2A-2D (and also in FIG. 4, see below) [0163] an axis (represented dashed in FIGS. 2A-2d), which is aligned perpendicularly to the rotation axis W and which runs through the middle of the active region 21 and through the rotation axis W; and [0164] an axis (represented dotted in FIGS. 2A-2D). which is aligned perpendicularly to the rotation axis W and which runs through the middle of the active region 21 and through the orbiting body axis can be selected as reference axes for the azimuthal orientation.

[0165] FIG. 2A illustrates the situation roughly at the beginning of an engagement, where the tool 2 just comes into contact with the workpiece 1. The azimuthal angle φ in the illustrated example is roughly 317°, corresponding to −43°.

[0166] FIG. 2B illustrates the situation roughly in the middle of the engagement. The azimuthal angle φ is a few degrees in the illustrated example.

[0167] FIG. 2C illustrates the situation roughly at the end of the engagement, where the tool 2 is still only just in contact with the workpiece 1. The azimuthal angle φ is roughly 40° in the illustrated example.

[0168] FIG. 2D illustrates the situation shortly after the end of the engagement, wherein the tool 2 just leaves contact with the workpiece 1. The azimuthal angle φ is a good 70° in the illustrated example.

[0169] For example, by way of the second synchronisation device S5, one can effectuate the tool 2 running through the azimuthal angle region, here for example from −43° to a good 70° during the engagement with the workpiece 1, with each orbiting.

[0170] By way of this, one can prevent the tool 2 from coming into (reshaping) contact with the workpiece shoulder 13—but despite this the formation of the profile can take place right up to the workpiece shoulder 13.

[0171] For this purpose, the tool 2 is a sectoral tool. It includes the free region 22, which is subsequent to the active region and in which it is set back radially (with respect to the rotation axis W).

[0172] As can be simply recognised from FIG. 2A, the workpiece 1 at the end. which is represented at the right, instead of ending there can include a further workpiece projection (indicated in a dotted manner in FIG. 2A). In such a case, by way of the described method it is possible to produce the profiling between the two workpiece projections such that it extends right up to the respective workpiece projection.

[0173] FIG. 3 shows a tool holder 5 with a tool 2, in a section through its rotation axis W. It (optionally) includes two planet gears 45, whose axes are coaxial with the rotation axis W, and two bearing regions 2L for the rotatable mounting in the orbiting body 8 (see FIG. 1). The tool holder 5 can be designed as one piece. The tool 2 forms a part of a tool insert 2e, which is fixedly connected to the tool holder 5, for example is screwed to this.

[0174] The tool 2 can be fastened on the tool holder 5 in a rotationally fixed manner relative to the planet gears 45.

[0175] FIG. 4 in a view onto section perpendicular to the rotation axis W illustrates a detail of a planetary gear 40 of the apparatus, for example including planet gears 45 as are integrated in the tool holder 5 according to FIG. 3, of which however only one is visible in FIG. 4.

[0176] The planetary gear 40 includes a ring gear 41 with an axis 42 and apart from this can yet include a second ring gear, which is not represented in FIG. 4 and in which the second planet gear of the tool holder 5 runs.

[0177] The axis 46 of the planet gear 45 is coaxial with the rotation axis W. And the orbiting body axis V (corresponding to the axis of the orbiting movements of the tool carrier) is coaxial with the axis 42 of the ring gear 41.

[0178] By way of a suitable dimensioning of the planetary gear 40, one can ensure, for example, that with each orbit the tool 2 has the same azimuthal alignment at a certain position along the orbiting path U (see FIG. 1) of the tool carrier 5, for example where the engagement with the workpiece 1 is to be terminated.

[0179] Instead of a planetary gear with two ring gears and two planet gears, the planetary gear for example can also be realised with no more than one ring gear and no more than one planet gear.

[0180] The mechanical demands on the tool holder 10 can be greatly reduced if two tool engagements take place with each tool engagement, and specifically at locations of the workpiece 1, which lie opposite one another with respect to the longitudinal axis, and in particular also axially (with respect to the longitudinal axis Z) at the same position.

[0181] FIG. 5 illustrates a detail of an apparatus 100 with two profiling heads 3a, 3b wherein moreover yet a radial feed is symbolised. The orbiting bodies (each including at least one tool carrier) and, inasmuch as is provided, the planetary gear, can be mounted in the profiling heads 3a, 3b.

[0182] The profiling heads 3a, 3b or the parts that are mounted in them can be essentially of the same type but be designed in a mirror-imaged manner with regard to the movements.

[0183] The workpiece 1 (dashed), which is represented in a symbolised manner in FIG. 5, by way of this can be machined in a mirror-imaged manner by way of two tools that lie opposite one another with respect to the longitudinal axis Z.

[0184] The movements of the two orbiting bodies can accordingly be synchronised with one another or result from one and the same movement, for example from one and the same rotation drive. And one or more ring gears can be fixed in each of the profiling heads.

[0185] In the course of the machining, it can be advantageous if the tools can be fed radially thus in a direction perpendicular to the longitudinal axis, since the profile gaps that are in the process of emerging become deeper and deeper with an increasing number of engagements. This is also the case if only a single profiling head is provided or a tool engagement only takes place from one side or takes place simultaneously by no more than a single tool.

[0186] Such a radial feed movement is symbolised in FIG. 5 by the open arrows, which are indicated at L2. It can take place along an axis that runs perpendicularly to the longitudinal axis and is parallel to a plane that is described by the orbiting movement of the tool holder.

[0187] A drive A2 for the radial feed can be provided for this.

[0188] By way of the radial feed, the trajectory or movement path of the tool holder results from a superposition of the orbiting movement U with the (linear) radial feed movement as is schematically illustrated in FIG. 6A-6C.

[0189] Herein, FIG. 6A symbolises an orbiting path U of a tool holder

[0190] FIG. 6B symbolises a radial feed movement L2.

[0191] FIG. 6C symbolises a trajectory T of a tool holder, which results as a superposition of the orbiting movement U and the radial feed L2. Herein, in reality, the distances between the roughly circular trajectories constituents are very much smaller than are represented in FIG. 6C for the sake of clarity.

[0192] FIG. 7 illustrates a detail of an apparatus 100 with two profiling heads which each include three tool holders 5a1, 5a2, 5a3 and 5b1, 5b2, 5b3 each with two tools 2a1, 2a1′ and 2a2, 2a2′ respectively.

[0193] By way of (possibly per profiling head) several tool holders 5a1, 5a2, . . . being provided, several engagements can take pace per orbit of an orbiting body, which leads to a quicker machining and can therefore render possible a creation of the profiling within a short time

[0194] By way of several tools being provided per tool holder, their service life can be increased and hence a longer interruption-free profiling is rendered possible. For example, the second synchronisation device S5 (see FIG. 1) can be configured such that given n tools per tool holder, after one orbit of the orbiting body 8, each of the tools at a certain position along the orbiting path U (see FIG. 1) of the tool carrier 5 (for example where the engagement with the workpiece 1 is to be terminated) has an azimuthal orientation that differs from the azimuthal position at the beginning of the orbiting by 360°/n. The difference can also be a multiple of 360°/n as long as this multiple is different from 360° and from a multiple of 360°.

[0195] It is further illustrated in FIG. 7 that profilings between two profiling delimitation structures, for example between two workpiece shoulders 13, 13′, can also be created by way of the method, which is described in this text, wherein the profilings can each reach up to the profiling delimitation structures.

[0196] In a section perpendicular to the longitudinal axis Z, FIG. 8 shows a profile body 1p which includes a profiling P which can be produced by way of the described method or by way of the described apparatus. The profiling includes a multitude of profile gaps pl. Each of these profile gaps pl has arisen by way of successively carrying out a multitude of engagements of one or more tools 2, which each include an active region 21. Which, in the section according to FIG. 8, has a shape that corresponds essentially to the shape of a profile gap pl that is to be produced.

[0197] The profile body 1p is a hollow part, which is seated on an outwardly profiled mandrel 6 includes an outwardly projecting shoulder 13. On account of the use of a profiled mandrel 6, not only can an outer profiling be produced by the method, but also simultaneously yet an inner profiling.

[0198] Given solid parts or hollow parts which are seated on non-profiled mandrels, an outer profiling can be produced without an inner profiling being simultaneously co-produced.

[0199] Furthermore, it is possible to produce an inner toothing in a hollow part, without an outer profiling being produced in the hollow part. FIG. 9 illustrates this.

[0200] FIG. 9 in a section perpendicular to the longitudinal axis show a detail of a workpiece 1 that is seated on an outer-profiled mandrel 6 and is just about to be machined by way of a tool 2 in the described manner. Material of the workpiece 1 is then shaped into profile gaps 6p by way of the machining. The tool 2 has an extensive active region.

[0201] FIG. 10 is a section that contains the longitudinal axis Z and by way of an example shows that an outer surface of a machining region 11 of a workpiece 1 does not need to be designed cylindrically, but for example as represented, can be designed conically

[0202] FIG. 11 in a section perpendicular to the longitudinal axis Z and by way of an example shows that an outer surface 11a of a machining region 11 of a workpiece 1 does not necessarily need to be rotationally symmetrical, but for example can be polygonal as represented. What is represented in FIG. 11 is the case that the outer surface 11 a includes six part-surfaces; however, one can also envisage the outer surface 11a including many more part-surfaces. The workpiece 1 can be designed for example prismatically in the associated machining region.

[0203] FIG. 12 shows an example of a workpiece 1 or a profile body 1p with two axially distanced profiling delimitation structures 13, 13′ that stand radially outwards. The profiling P with its profile gaps pl which is produced by way of the described method reaches right up this these.

[0204] Profiling delimitation structures can also be directed radially inwards, relative to the adjacent section of the machining region. FIG. 13 shows an example of this, in which the profile delimitation structures 13 at an end of the machining region 12 are directed radially inwards and the profiling delimitation structures 13′ at the other end of the machining region 11 are directed radially outwards.

[0205] FIG. 14 by way of an example illustrates that a machining region 11 does not necessarily need to be delimited at one or two sides by profiling delimitation structures. Shown is a profile body, where both ends of the machining regions 11 are not adjacent to the profiling delimitation structures.

[0206] FIG. 15 by way of example illustrates that a profiling delimitation structure 13 of a workpiece 1 is not necessary rotationally symmetrical. In the illustrated example, several radially outwardly projecting workpiece projections are provided which are localised at different azimuthal positions.

[0207] In a section perpendicular to the longitudinal axis L, FIG. 16 illustrates a workpiece or a profile body 1p that has a profiling whose profile gaps 1p are distributed azimuthally in a non-uniform manner. Although profile gaps that are distributed uniformly over the periphery are preferred, there are applications for which an azimuthally irregular arrangement of profile gaps pl is advantageous.

[0208] Of course, a single workpiece can include two or more different machining regions, which for example can be axially distanced to one another and which are each provided with a profiling in the manner described in this text.