Forming tool, forming tool assembly, forming machine, forming method and computer program for producing a cylindrical workpiece with a helical outer contour by rotary kneading

Abstract

The invention relates to a forming tool (46) for a forming tool arrangement (12) for the multi-stage production of a cylindrical workpiece with a spiral outer contour by rotary swaging, comprising a force application side (62), a forming side (64) opposite the force application side (62) and a cam structure (70) formed on the forming side (64). The cam structure (70) has a first forming cam (72; 72a, 72b) and a second forming cam (72; 72a, 72b) which are arranged one behind the other in a longitudinal direction (74) of the forming tool (46) perpendicular to the forming direction (58), wherein the forming cams (72; 72a, 72b) have different cam heights (116) and the forming cams (72; 72a, 72b) have a cam direction (94) in an orthogonal view on the forming side (64) which is inclined to the longitudinal direction (74) of the forming tool (46).The invention also relates to a forming tool arrangement (12), a forming machine (10), a forming process and a computer program.

Description

[0001] The invention relates to a forming tool for a forming tool assembly for the multi-stage production of a cylindrical workpiece with a spiral outer contour by rotary swaging, comprising a forming side with a cam structure formed on the forming side. Such a forming tool is known from DE 103 28 052 A1.

[0002] The invention also relates to a forming tool arrangement with such a forming tool and a forming machine with a forming tool arrangement.

[0003] The invention further relates to a forming method and a computer program for controlling the forming machine during the process.

[0004] Components with a spiral outer contour are widely used. For example, in connection with screw drives, where threaded rods or threaded spindles are used to convert rotary motion into linear motion. Typical applications include scissor jacks, linear guides on machine tools, or steering spindles on motor vehicles. Depending on the specific application, different thread shapes are available, such as ball screws or trapezoidal threads, which can be designed as right-hand or left-hand threads.

[0005] Typically, the spiral outer contour is manufactured using machining processes. For example, DE 10 2014 225 104 B4 describes a method for machining a ball screw.

[0006] Such processes result in relatively high manufacturing costs when creating the spiral outer contour. If increased strength of the manufactured components is also desired, additional post-treatment processes must be performed after the spiral outer contour has been created. This further increases manufacturing costs.

[0007] It is therefore an object of the invention to provide an alternative and cost-effective production of components with a spiral-shaped outer contour.

[0008] This object is achieved according to the invention by a forming tool having the characterizing features of patent claim 1, a forming tool arrangement according to patent claim 10, a forming machine according to patent claim 15, a forming method according to patent claim 16 and a computer program according to patent claim 18. The subclaims relate to preferred embodiments of the invention.

[0009] According to the invention, a forming tool or a forming jaw is provided. The forming tool is designed for arrangement in a forming tool assembly, in particular a rotary swaging unit. Furthermore, the forming tool is suitable for the multi-stage production of a cylindrical workpiece with a spiral outer contour by rotary swaging. Preferably, the cylindrical workpiece is produced from a cylindrical workpiece blank.

[0010] According to the invention, multi-stage production includes the serial or spatially spaced action of the same forming tool and / or different forming tools on the same area of ​​the workpiece blank, with each stage contributing a gradual portion to the overall forming process.

[0011] The forming tool has a force introduction side for introducing a forming force into the forming tool. The force introduction side is preferably flat, which allows for a particularly uniform force introduction.

[0012] The forming tool also has a forming side opposite the force introduction side. The forming side is designed to introduce the forming force into the workpiece blank. In other words, the forming side is at least temporarily in engagement with the workpiece blank during the production of the cylindrical workpiece. The forming force is introduced in a forming direction. The forming direction is typically a radially inward direction of the cylindrical workpiece to be produced.

[0013] The force introduction side can be inclined relative to the forming direction. This allows the distance of the forming tool, when arranged in a forming tool arrangement, to be adjusted in a controlled manner by applying an adjustment wedge to the workpiece blank. Typically, the distance of the forming tool to the workpiece blank is adjusted depending on the outer diameter of the workpiece blank. The distance of the forming tool to the workpiece blank can also be adjusted by means of the adjustment wedge to a reduced outer diameter of the workpiece blank, for example, due to forming. In other words, the forming tool can be adjusted using the adjustment wedge.

[0014] The forming tool has a cam structure formed on the forming side. The cam structure can create a radial depression or notch on the workpiece blank to create the spiral-shaped outer contour.

[0015] Furthermore, the cam structure has at least a first forming cam and a second forming cam. Furthermore, the cam structure can have further forming cams. The forming cams are arranged one behind the other in a longitudinal direction of the forming tool, perpendicular to the forming direction. In other words, the forming cams of the cam structure are arranged in a row in the longitudinal direction. The longitudinal direction can correspond to a workpiece feed direction of a workpiece blank to be formed in a forming process during the production of a cylindrical workpiece with a spiral outer contour.

[0016] Each forming cam has a cam height, typically formed in the forming direction. According to the invention, the cam heights of at least two forming cams are different. In other words, at least one forming cam protrudes, typically in the forming direction, from at least one other forming cam. For example, the first forming cam has a different cam height than the second forming cam if the cam structure comprises only two forming cams. In the case of additional forming cams, two or more forming cams can have the same cam height, provided that at least one additional forming cam has a different cam height. Different cam heights enable multi-stage, in other words stepped, forming of the spiral-shaped outer contour in the forming direction.The forming tool can therefore penetrate the workpiece blank to be formed in several stages during a forming process without the forming tool having to be readjusted in the forming direction.

[0017] In an orthogonal view of the forming side, the forming cams have a cam path direction that is oblique to the longitudinal direction of the forming tool. The cam path direction is preferably deflected by a pitch angle relative to a transverse direction perpendicular to the longitudinal direction. The pitch angle can be between 1 degree and 89 degrees, preferably between 5 degrees and 45 degrees, and particularly preferably between 10 degrees and 30 degrees. Typically, the cam path direction has the same pitch angle as the spiral outer contour of the workpiece to be manufactured.

[0018] In summary, the forming tool according to the invention has a cam structure, which is formed by the forming cams in sections complementary to the spiral outer contour of the cylindrical workpiece to be created. The spiral outer contour can be created by the forming cams acting on the workpiece blank at least twice, forming a spiral notch or depression. Typically, a spiral relative movement between the forming tool and the workpiece blank to be formed is superimposed on the forming process.

[0019] In a preferred embodiment of the forming tool, the forming side has a forming groove extending in the longitudinal direction. The forming groove typically has a groove base with a circular segment shape in cross-section. The cam structure is typically arranged, in particular entirely, within the forming groove.

[0020] A preferred development of the forming tool is one in which the forming groove has a groove section with a cross-section tapering in the longitudinal direction or in the workpiece feed direction (entry section). Typically, in this case, the groove base has a circular segment radius that decreases in the longitudinal direction. In particular, the circular segment radius decreases from a radius of the workpiece blank to an outer radius of the spiral outer contour of the workpiece to be manufactured.

[0021] Alternatively or additionally, the forming groove can have a groove section with a constant cross-section in the longitudinal direction or in the workpiece feed direction (calibration section).

[0022] The cam structure can have at least one forming cam arranged in the groove section with a tapered cross-section and / or in the groove section with a constant cross-section. Preferably, the forming groove has both an inlet section and a calibration section, each with at least one forming cam arranged therein, with the calibration section being arranged downstream of the inlet section in the longitudinal direction. This allows the spiral-shaped outer contour to be produced with particular precision.

[0023] In a preferred embodiment of the forming tool, the cam structure has at least three, preferably at least six, particularly preferably at least twelve, forming cams. A larger number of forming cams can reduce the gradual contribution of a single forming cam to the overall forming process during the creation of the spiral outer contour. This can increase the manufacturing accuracy of the spiral outer contour. Alternatively or additionally, a larger number of forming cams can improve the creation of a spiral outer contour with multiple turns, in particular thread turns.

[0024] The forming cams are preferably arranged equidistant from one another in the longitudinal direction. In other words, adjacent forming cams of the cam structure are spaced the same distance apart in the longitudinal direction. This allows, for example, a multi-start spiral-shaped outer contour to be created with equal spacing between the individual threads or with a uniform pitch.

[0025] Furthermore, an embodiment of the forming tool is preferred in which at least one of the forming cams, preferably several of the forming cams, particularly preferably all of the forming cams, has or have a forming section curved around the longitudinal direction. The curved forming section can be understood as a part of the forming cam that creates a root circle of the spiral outer contour to be created. As a result, a section of the corresponding forming cam that acts on the workpiece blank can be made larger in the cam direction, thereby allowing a larger outer area of ​​the workpiece blank to be formed.

[0026] In a preferred embodiment of the forming tool, at least one of the forming cams has a cam contour that is curved, triangular, or trapezoidal in the longitudinal direction or in the workpiece feed direction. Preferably, a first forming cam of the cam structure in the longitudinal direction has a curved cam contour. Further preferably, the cam contours of the forming cams following the first forming cam, in particular a profile shape, approximate the spiral outer contour to be created of the cylindrical workpiece. Particularly preferably, the cam contour is increasingly adapted to the spiral outer contour to be created with increasing deformation of the workpiece blank by the forming cams. The inventors have recognized that this can increase the manufacturing quality of the cylindrical workpiece with a spiral outer contour.

[0027] Further preferred is an embodiment of the forming tool in which at least one of the forming cams has a first cam flank and a second cam flank. A cam flank is to be understood as a forming section of the forming cam that is formed predominantly in the direction of the cam extension, wherein the forming section causes a continuous flank of the spiral outer contour to be created. The first and second cam flanks of a forming cam typically form opposite flanks of the same notch of the spiral outer contour. Preferably, several forming cams of the cam structure have a first and a second cam flank. At least one forming cam of the cam structure, typically the last one formed in the longitudinal direction, has a first and a second cam flank that corresponds to a flank shape of the spiral outer contour to be created.The first cam flank and the second cam flank are typically inclined to the forming direction. This can further improve manufacturing quality.

[0028] Alternatively or additionally, at least one forming cam can have an inlet section and / or outlet section formed in the direction of the cam extension. The inlet section is preferably designed as a section tapering counter to the direction of the cam extension. The outlet section is preferably designed as a section tapering in the direction of the cam extension. The inlet section or the outlet section can enable the forming cam to be easily inserted into or removed from an existing notch on the outer contour of the workpiece blank during the forming of a workpiece blank. In a special embodiment, the inlet section is arranged upstream of the forming section having the cam flanks in the direction of the cam extension, and the outlet section is arranged downstream of the forming section having the cam flanks in the direction of the cam extension.

[0029] In a preferred embodiment of the forming tool, the first and second cam flanks of at least one forming cam form a cam angle of at most 40 degrees, preferably of at most 30 degrees, particularly preferably of at most 20 degrees. The cam angle can correspond to a flank angle of the spiral-shaped outer contour to be created. A smaller cam angle enables the formation of a steeper flank angle on the spiral-shaped outer contour to be created.

[0030] A preferred embodiment of the forming tool is one in which the forming tool has a forming tool section that tapers in the forming direction. The forming tool section is preferably trapezoidal in a longitudinally projected view. In other words, the forming side has a smaller area than the force introduction side. This allows a forming force introduced via the force introduction side to be concentrated on a smaller forming surface on the workpiece blank.

[0031] The underlying problem is also solved by a forming tool arrangement, for example a rotary swaging unit, for a forming machine for the multi-stage production of a cylindrical workpiece with a spiral-shaped outer contour by rotary swaging.

[0032] The forming tool assembly comprises at least one first forming tool, as described above and below, and at least one second forming tool, as described above and below. Furthermore, the forming tool assembly may comprise further forming tools, as described above and below. The forming tools are preferably of identical construction or design. This allows for cost savings in the manufacture of the forming tool assembly by using a higher number of identical parts.

[0033] The forming tools are arranged concentrically around a central axis of the forming tool assembly. Typically, the central axis corresponds to a workpiece axis of the workpiece blank when the workpiece blank is arranged in the forming tool assembly. The forming tools at least partially enclose the workpiece blank during the creation of the spiral outer contour.

[0034] The forming tools are aligned with their respective forming sides facing the central axis. In other words, the forming tools are aligned radially inward. The forming tool arrangement is designed for radial deflection of the forming tools in the direction of the central axis. In other words, the forming tools are deflected by the forming tool arrangement according to their respective forming direction. Typically, the forming tools are moved toward each other. By radially deflecting the forming tools, a radial force can be introduced into the workpiece blank to be formed in the respective forming direction of a forming tool.

[0035] According to the invention, the first forming cam of the first forming tool is arranged together with one of the forming cams of the second forming tool on a first helical line. In other words, the forming cams of different forming tools are arranged on a common helical line. The creation of the spiral outer contour can thus be achieved by the multi-stage action of forming cams of different forming tools on the same workpiece section of the workpiece blank.

[0036] The forming tool arrangement can also have an outer ring, a roller cage that can be driven by a motor, in particular by means of the outer ring, a guide insert, and at least two rams. The roller cage is typically arranged concentrically within the outer ring and designed for the arrangement of several rollers rotatably held on the roller cage. The rollers can protrude radially outwards and radially inwards beyond the roller cage. The roller cage is usually in permanent contact with the outer ring by means of the rollers on the radially outer side. The guide insert, which is designed to radially movably accommodate the forming tools and in particular the rams, is usually arranged within the roller cage. When rams are used, a ram and a forming tool can each form a common forming punch. In other words, the ram and forming tool are radially deflected together.Typically, the rams protrude radially outward beyond the guide insert and are designed to temporarily contact the rollers of the roller cage. During operation of the forming tool assembly, the roller cage rotates, with the rollers regularly rolling over the rams, thereby deflecting them radially. In other words, each roll of the ram creates a radially inward forming impact. The impact rate depends on the speed of the roller cage.

[0037] In a preferred embodiment of the forming tool arrangement, the second forming cam of the first forming tool is arranged on the first helical line. Such an arrangement of the forming tools enables, for example, the creation of a spiral outer contour with only one thread. Alternatively, it can be provided that the second forming cam of the first forming tool is arranged together with one of the forming cams of the second forming tool on a second helical line. This can enable, for example, the creation of a spiral outer contour with at least two threads.

[0038] Further preferred is an embodiment of the forming tool arrangement in which both forming cams of the second forming tool are arranged on the first helical line. This allows the gradual contribution of the individual forming tools and the gradual contribution of the individual forming cams to the overall forming process, or the formation of the spiral notch, to be reduced, thereby further improving manufacturing quality.

[0039] In a preferred embodiment of the forming tool arrangement, it comprises at least one further forming tool, as described here and below. According to the embodiment, one of the forming cams of the further forming tool can be arranged on the first helix. This allows the gradual proportion of the individual forming cams to be further reduced and the manufacturing quality to be further increased. Alternatively or additionally, it can be provided that one of the forming cams of the further forming tool is arranged on the second helix. This allows the manufacturing quality to be increased when creating a spiral-shaped outer contour with two threads.

[0040] Furthermore, an embodiment of the forming tool arrangement is preferred in which the forming tools have a plurality of forming cams, preferably at least six, particularly preferably at least twelve. The first forming cams of the forming tools are preferably arranged on different helical lines. Particularly preferably, the forming cams of a forming tool following the first forming cam in the respective longitudinal direction are arranged alternately with the helical line of the same workpiece on the helical lines of the further forming tools. In other words, the forming tool arrangement is designed to form a number of threads on the spiral outer contour that is equal to the number of forming tools. Typically, the forming tools in this case are of the same design, in particular identical, and are arranged in the forming tool arrangement without any offset to one another along the central axis.

[0041] The underlying problem is further solved by a forming machine. The forming machine is suitable for the multi-stage production of a cylindrical workpiece with a spiral outer contour through rotary swaging.

[0042] The forming machine has the forming tool arrangement described here and below.

[0043] The forming machine also has a feed device. The feed device is designed for positioning, in particular clamping, the workpiece blank. Typically, the feed device comprises a collet chuck for this purpose. Furthermore, the feed device is designed to be translationally movable relative to the forming tool assembly in the workpiece feed direction or along the center axis of the forming tool assembly.

[0044] Furthermore, the forming machine comprises a machine control system configured to regulate machine parameters. Typically, the machine control system regulates at least the rotational speed of the forming tool assembly and a feed rate of the feed device. Furthermore, the forming machine is configured to perform a relative rotational movement between the forming tool assembly and the feed device. In other words, when a workpiece blank is arranged, the forming machine is configured to perform a rotational movement of the workpiece blank relative to the forming tools.

[0045] In a specific embodiment of the forming machine, the forming machine may be provided with a mandrel device. The mandrel device typically comprises a forming mandrel that is arranged within a hollow cylindrical workpiece blank prior to a forming process. The mandrel device is preferably arranged on the feed device.

[0046] Furthermore, the underlying problem is solved by a forming process. This forming process is suitable for the multi-stage production of a cylindrical workpiece with a spiral outer contour through rotary swaging.

[0047] The forming process is carried out using a forming machine described here and below and comprises the following process steps.

[0048] One method step involves arranging, in particular clamping, a workpiece blank on the forming machine. Preferably, the workpiece blank is clamped in the feed device, in particular by means of a collet chuck. Typically, the workpiece blank is arranged on the forming machine such that a workpiece axis of the workpiece blank coincides with the center axis of the forming tool arrangement.

[0049] A further method step provides for the production of the cylindrical workpiece with the spiral-shaped outer contour by moving the feed device in the workpiece feed direction and simultaneously carrying out the relative rotational movement between the forming tool arrangement and the feed device.

[0050] The relative rotational movement is adapted to the movement in the workpiece feed direction in such a way that the forming cams along the helical lines cause a plastic deformation of the workpiece blank, in particular a spiral notch on the outside of the workpiece blank, by radial deflection of the forming tools.

[0051] The inventors have recognized that a feed rate for movement in the workpiece feed direction is preferably less than 50 millimeters per second to ensure good manufacturing quality with short production times. Particularly preferred is the feed rate between 5 and 30 millimeters per second. This ensures particularly high manufacturing quality.

[0052] Furthermore, the inventors have recognized that a stroke rate of the forming tools between 10 and 100 strokes per second, preferably between 20 and 60 strokes per second, particularly preferably 40 strokes per second, results in a high surface quality on the workpiece.

[0053] Preferably, the relative rotational movement between the forming tool assembly and the feed device, or the workpiece blank, is adapted to the impact rate. This allows a so-called transfer angle between two consecutive forming strokes to be predetermined. A transfer angle of no more than 40 degrees, preferably no more than 20 degrees, and particularly preferably no more than 5 degrees, has proven particularly advantageous with regard to the manufacturing quality of the workpiece's spiral-shaped outer contour, in particular the one to be created.

[0054] In a preferred embodiment of the forming method, the cylindrical workpiece is produced from a hollow workpiece blank. According to the embodiment, a forming mandrel is arranged within the hollow workpiece blank before producing the cylindrical workpiece with the spiral outer contour. In other words, the spiral outer contour is created via a forming mandrel. This allows a workpiece with a precise inner contour to be produced, since the forming mandrel prevents radial material flow during forming.

[0055] In addition, the underlying task is solved by a computer program.

[0056] The computer program is designed to operate the forming machine described here and below. The forming machine is designed with a numerical control system.

[0057] The computer program includes control commands for the machine control system which cause the forming process described here and below to be carried out by the forming machine when the computer program is running on the numerical machine control system of the forming machine.

[0058] Further features and advantages of the invention will become apparent from the description, the claims, and the drawings. According to the invention, the above-mentioned and further-described features can be used individually or in combination in any convenient way. The embodiments shown and described are not intended to be exhaustive, but rather are exemplary in nature for describing the invention.

[0059] The invention is explained in more detail below using exemplary schematic representations.

[0060] It shows: Figure 1 shows a forming machine with a forming tool arrangement and a feed device in a perspective view. Figure 2 shows a first embodiment of a forming tool arrangement with a roller cage, several rams and several forming tools in a perspective view. Figure 3 shows a partial view of a second embodiment of a forming tool arrangement with several forming tools in a sectional side view. Figure 4 shows the forming tool arrangement from Figure 3 with workpiece blank arranged therein. Figure 5An alternative forming tool arrangement with workpiece blank arranged therein. Figure 6a forming tool of the forming tool arrangement from the Figures 3 and 4 in an orthogonal view of a forming side. Figure 7 the forming tool from Figure 6 in a perspective view. Figure 8 shows a partial section of the forming tool from the Figures 6 and 7 in a sectioned view.

[0061] According to Figure 1 has a forming machine 10 a forming tool arrangement 12 and a partially shown feed device 14 By means of the feed device 14, a 16 clamped workpiece blank 18, e.g. a pipe, along a feed axis 20 the feed device 14 or along a central axis 22 the forming tool arrangement 12.

[0062] The feed axis 20 coincides with a longitudinal axis 24 of the clamped workpiece blank 18. Via an insertion opening 26 on a front side 28 the forming tool arrangement 12, the clamped workpiece blank 18 with a workpiece longitudinal section to be machined can be introduced into the forming tool arrangement 12. In other words, the workpiece blank 18 can be subjected to an axial movement 29in the direction of the forming tool arrangement 12.

[0063] The feed device 14 is designed to effect a rotary movement 30 of the workpiece blank 18 about the feed axis 20. The feed device 14 comprises drive means (not shown in detail) for this purpose. The feed device 14 is designed to superimpose the rotary movement 30 with the axial movement 29.

[0064] The forming machine 10 or the forming tool arrangement 12 can have a drive unit not shown in detail, typically an electric motor.

[0065] The drive unit is typically designed to drive the forming tool assembly 12.

[0066] The forming machine 10 further comprises a machine control 34 for controlling the forming machine 10. For this purpose, the machine control 34 is connected via schematically illustrated communication links 36connected to the forming tool arrangement 12 and the feed device 14.

[0067] In Figure 2 a forming tool arrangement 12 is shown as a solitary assembly.

[0068] As shown, the forming tool arrangement 12 comprises a roller cage 38, several rollers arranged on the roller cage 38 42, several - here four - pestles 44 and an equal number of forming tools 46. A ram 44 and a forming tool 46 together form a forming punch 48 In addition, as shown, each forming punch 48 has an adjusting wedge arranged between the ram 44 and the forming tool 46 50 For reasons of clarity, only a roller 42, a ram 44, a forming tool 46, a forming punch 48, and an adjusting wedge 50 are provided with a reference symbol.

[0069] The rollers 42 are rotatably mounted on the roller cage 38. As shown, the roller cage 38 can have cylindrical recesses into which the rollers 42 are inserted parallel to the central axis 22.

[0070] The roller cage 38 is formed concentrically to the central axis 22 and has a radially outer side 52 and a radially inner side 54 The rollers 42 project radially beyond the roller cage 38 on the radially outer side 52 and on the radially inner side 54. Typically, the rollers 42 bear against an outer ring (not shown in detail) on the radially outer side 52, or the roller cage 38 is supported on the outer ring by means of the rollers 42.

[0071] The forming dies 48 are arranged within the roller cage 38 such that one forming side 56of the forming tools 46 radially inward in the direction of the central axis 22 of the forming tool arrangement 12 or in a forming direction 58 of the forming tools 46. As shown, the forming tools 46 are arranged concentrically to the central axis 22.

[0072] Furthermore, according to the embodiment shown, the forming dies 48 are arranged distributed uniformly over a radial inner circumference of the roller cage 38 or the radially inner side 54 of the roller cage 38.

[0073] During operation of the forming tool assembly 12, the roller cage 38 is set into a rotational movement 60relative to the forming punches 48. The rollers 42 pass the rams 44, which displace them radially inward and cause a forming force in the forming direction 58. Depending on the speed of the roller cage 38 and the number of rollers 42, a stroke rate is predetermined, which defines the number of forming movements per unit of time.

[0074] By means of the adjustment wedge 50, a radial extension of the forming punch 48 is adapted to an outer diameter of a workpiece blank 18 to be formed. For this purpose, the adjustment wedge can be moved parallel to the central axis 22 in order to reduce or increase the radial extension of the forming punch 48.

[0075] In Figure 3 is a tool arrangement 12 in a sectional side view of a Fig. 2 marked cutting plane XXThe tool assembly 12 has four identical forming tools 46, of which only three are visible due to the sectional view. The forming tools 46 are arranged concentrically around the central axis 22 of the tool assembly 12.

[0076] Each forming tool 46 has a force introduction side 62 and a forming side opposite the force introduction side 62 64 To form a workpiece blank 18, a force is introduced via the force introduction side 62 into the forming tool 46 and via the forming side 64 into the workpiece blank 18 to be formed. In other words, a force is applied in the forming direction 58. The forming direction 58 of each forming tool 46 is typically directed toward the central axis 22 of the forming tool arrangement 12.

[0077] The force introduction side 62 of a forming tool 46 can, preferably the force introduction sides 62 of all forming tools 46, as shown, be formed obliquely to the forming direction 58. In other words, the force introduction side 62 can form an angle 66 with a plane perpendicular to the forming direction 58 68 This allows an adjusting wedge 50 (see Fig. 2 ) on the force introduction side 62, wherein the adjusting wedge 50 preferably has a wedge angle which is identical to the angle 66.

[0078] The forming sides 64 of the forming tools 46 each have a cam structure 70 Each cam structure 70 has several - here fourteen - forming cams 72 For reasons of clarity, only two cam structures 70 and one in the longitudinal direction 74of the respective forming tool 46, the first forming cam 72 of the two cam structures 70 is provided with a reference symbol.

[0079] The forming cams 72 of each cam structure 70 are arranged one behind the other in the longitudinal direction 74 of the respective forming tool 46. The longitudinal direction 74 preferably runs parallel to the axial movement 29 (see Fig. 1 ) of a workpiece blank 18 (see Fig. 1 ) during the creation of a cylindrical workpiece.

[0080] Figure 4 shows the tool arrangement 12 from Figure 3 with a workpiece blank 18 located in the tool arrangement 12 to explain the production of a cylindrical workpiece with a spiral outer contour.

[0081] For this purpose, the workpiece blank 18 of the forming tool arrangement 12 is fed with a feed movement 76,which results from a superposition of the axial movement 29 and the rotary movement 30. The workpiece blank 18 is moved along the central axis 22 between the forming tools 46, wherein the forming tools 46 temporarily act radially on the workpiece blank 18 in the respective forming direction 58. In this case, the forming sides 64, in particular the cam structures 70, cause a plastic deformation of the workpiece blank 18. The forming cams 72 form a notch 78 on the workpiece blank 18, which creates a spiral-shaped outer contour due to the feed movement 76.

[0082] The axial movement 29 is coordinated with the rotational movement 30 in such a way that, due to the resulting feed movement 76, a section of the workpiece blank 18 formed by a forming cam 72 of a first forming tool 46 is fed to a forming cam 72 of a forming tool 46 located immediately downstream in the direction of rotation of the rotational movement 30. In other words, the notch 78 initiated by a forming cam 72 is continuously formed in multiple stages by further forming cams 72 of further forming tools 46. As shown, the notch 78 can be created by different forming cams 72 of different forming tools 46 and different forming cams 72 of the same cam structure 70 of a forming tool 46.

[0083] Individual and / or multiple forming cams 72 of one and / or multiple forming tools 46 are therefore arranged on at least one common first screw line 80As shown, the notch 78 runs along the first screw line 80. For reasons of clarity, Figure 4 only one notch 78 is shown. Furthermore, it is self-explanatory that according to the illustrated embodiment, further notches 78, for example along a second helix 82 can be formed by the forming sides 64. The number of screw lines 80, 82 is preferably equal to the number of forming tools 46.

[0084] As shown, during the creation of the cylindrical workpiece with the spiral outer contour, an initial diameter 84 of the workpiece blank 18 to a final diameter 86 reduced. In other words, the workpiece blank 18 undergoes a diameter reduction.

[0085] Figure 5 shows an alternative tool arrangement 12 in a sectional side view analogous to that in Fig. 2 marked section plane XX. The tool arrangement 12 has four different forming tools 46. Due to the sectional representation, only three forming tools 46 are shown in the Figure 5 The forming tools 46 are arranged concentrically around the central axis 22 of the tool arrangement 12.

[0086] The cam structures 70 of the various forming tools 46 are coordinated with one another along the center axis 22, or are formed on the respective forming tool 46, in such a way that a spiral-shaped outer contour is formed with only a single notch 78. In other words, the spiral-shaped outer contour has only one thread.

[0087] According to the illustrated embodiment, all forming cams 72 of the respective cam structure 70 and all forming cams 72 of the other forming tools 46 are located on the, here only, screw line 80.

[0088] The forming process for creating the spiral outer contour is analogous to the description in Figure 4 applicable.

[0089] Figure 6 shows a single forming tool 46 in a plan view of the forming side 64.

[0090] The forming side 64 has a forming groove 88 The cam structure 70 can be arranged entirely within the forming groove 88, as shown.

[0091] The forming groove 88 has an inlet section 90 with a tapered cross-section. The inlet section 90 is designed to reduce the diameter of a workpiece blank 18 to be formed (see Fig. 4 ). Preferably, the cam structure 70 has at least one forming cam 72 in the inlet section 90. As shown, the cam structure 70 has seven forming cams 72 arranged entirely in the inlet section 90.

[0092] The forming groove 88 also has a calibration section92 with a constant cross-section. The calibration section 92 is designed for fine forming of the workpiece blank 18. Typically, the gradual portion of the total forming at the forming cams 72 in the calibration section 92 is less than the gradual portion at the forming cams 72 in the inlet section. For this purpose, according to the illustrated embodiment, the calibration section 92 has five forming cams 72 of the cam structure 70 arranged entirely within the calibration section 92.

[0093] The forming cams 72 of the cam structure 70 have a cam direction 94 which extends to a transverse direction perpendicular to the longitudinal direction 74 96 with a pitch angle 98is designed differently. In other words, the cam direction 94 runs obliquely to the longitudinal direction 74. Preferably, all forming cams 72, as shown, have the same cam direction 94. In other words, the forming cams 72 are designed parallel to one another.

[0094] In Figure 7 the forming tool 46 is made of Figure 6 shown in a perspective view.

[0095] According to the embodiment shown, the forming tool 46 has a forming tool section tapering in the forming direction 58 100 The forming tool section 100 has, on its side facing away from the force introduction side 62, the forming groove 88 with the cam structure 70 arranged or formed therein.

[0096] The forming groove 88 typically has a circular segment-shaped groove base in its cross section 102This allows a circular cross-section of the workpiece blank 18 to be maintained and / or created during forming.

[0097] Figure 8 shows an enlarged partial section of the forming tool 46 from the Figures 6 and 7 in a longitudinal section through the forming groove 88 and the cam structure 70.

[0098] The cam structure 70 has forming cams 72a with a cam contour curved in the longitudinal direction 74 104 Furthermore, the cam structure 70 can be formed cams 72b with a trapezoidal cam contour running in the longitudinal direction 74 106For reasons of clarity, only one forming cam 72a, one forming cam 72b, one curved cam contour 104, and one trapezoidal cam contour 106 are provided with a reference numeral. As shown, the first forming cams 72 in the longitudinal direction 74 have the curved cam contour 104, and the last forming cams 72 in the longitudinal direction 74 have the trapezoidal cam contour 106.

[0099] The forming cams 72, in particular the forming cams 72b with trapezoidal cam contour 106, can have a first cam flank 108 and a second cam flank 110 The first cam flank 108 is positioned in front of the second cam flank 110 in the longitudinal direction 74. The first cam flank 108 and the second cam flank 110 of the same forming cam 72 form a cam angle 112The first cam flank 108 and the second cam flank 110 or the second cam flank 110 and the first cam flank 108 of adjacent forming cams 72 form a notch angle 114 out of.

[0100] A cam height 116 each forming cam 72 is measured between a cam height 118 and the groove base 102 in the forming direction 58. The cam height 108 preferably increases in the longitudinal direction 74, in particular continuously. List of reference symbols

[0101] Forming machine 10; Forming tool arrangement 12; Feed device 14; Collet 16; Workpiece blank 18; feed axis 20; central axis 22; Longitudinal axis 24; Insertion opening 26; Front 28; axial movement 29; rotational movement 30; Machine control 34; Communication connections 36; roller cage 38; Roll 42; pestle44; Forming tool 46; Forming stamp 48; Adjusting wedge 50; radial outer side 52; radial inner side 54; Forming side 56; Forming direction 58; rotational movement 60; Force introduction side 62; Forming side 64; Angle 66; Plane 68; Cam structure 70; Forming cam 72, 72a, 72b; Longitudinal direction 74; feed movement 76; notch 78; first helix 80; second helix 82; Output diameter 84; Final diameter 86; Forming groove 88; Inlet section 90; Calibration section 92; Cam direction 94; Transverse direction 96; Pitch angle 98; Forming tool section 100; Groove base 102; curved cam contour 104; trapezoidal cam contour 106; first cam flank 108; second cam flank110; Cam angle 112; Notch angle 114; Cam height 116; Cam peak 118; Cutting plane XX.

Claims

1. Forming tool (46) for a forming tool arrangement (12) for the multi-stage production of a cylindrical workpiece with a spiral-shaped outer contour by rotary swaging, comprising • a force introduction side (62) for introducing a forming force into the forming tool (46); • a forming side (64) opposite the force introduction side (62) for introducing the forming force in a forming direction (58) into the workpiece blank (18); and • a cam structure (70) formed on the forming side (64); characterized in that • the cam structure (70) has a first forming cam (72; 72a, 72b) and a second forming cam (72; 72a, 72b) which are arranged one behind the other in a longitudinal direction (74) of the forming tool (46) perpendicular to the forming direction (58); wherein • the forming cams (72; 72a, 72b) have different cam heights (116); and wherein • the forming cams (72; 72a, 72b) in an orthogonal view of the forming side (64) have a cam direction (94) which is formed obliquely to the longitudinal direction (74) of the forming tool (46).

2. Forming tool (46) according to claim 1, characterized in that the forming side (64) has a forming groove (88) which extends in the longitudinal direction (74) and has a groove base (102) that is circular segment-shaped in cross section, wherein the cam structure (70) is arranged in the forming groove (88).

3. Forming tool (46) according to claim 2, characterized in that the forming groove (88) has an inlet portion (90) having a cross section which tapers in the longitudinal direction (74) and / or a calibration portion (92) having a cross section which is constant in the longitudinal direction (74), wherein at least one of the forming cams (72; 72a, 72b) is arranged in the inlet portion (90) and / or in the calibration portion (92).

4. Forming tool (46) according to any of the preceding claims, characterized in that the cam structure (70) has at least three, preferably at least six, particularly preferably at least twelve, forming cams (72; 72a, 72b) which are arranged equidistant from one another in the longitudinal direction (74).

5. Forming tool (46) according to any of the preceding claims, characterized in that at least one of the, preferably a plurality of the, particularly preferably all of the, forming cams (72; 72a, 72b) have a forming portion which is curved around the longitudinal direction (74) or towards the longitudinal direction (74).

6. Forming tool (46) according to any of the preceding claims, characterized in that at least one of the forming cams (72; 72a, 72b) has a cam contour (104, 106) which is curved and / or trapezoidal in the longitudinal direction (74).

7. Forming tool (46) according to any of the preceding claims, characterized in that at least one of, preferably a plurality of, forming cams (72; 72a, 72b) have a first cam flank (108) and a second cam flank (110), wherein the first cam flank (108) and the second cam flank (110) are inclined to the forming direction (58).

8. Forming tool (46) according to claim 7, characterized in that the first and the second cam flank (108, 110) of at least one forming cam (72; 72a, 72b) form a cam angle (112) of at most 40 degrees, preferably of at most 30 degrees, particularly preferably of at most 20 degrees.

9. Forming tool (46) according to any of the preceding claims, characterized in that the forming tool (46) has a forming tool portion (100) which tapers in the forming direction (58).

10. Forming tool arrangement (12) for a forming machine (10) for the multi-stage production of a cylindrical workpiece with a spiral-shaped outer contour by rotary swaging, comprising a first forming tool (46) according to any of the preceding claims and a second forming tool (46) according to any of the preceding claims; wherein the forming tools (46) are arranged concentrically about a central axis (22) of the forming tool arrangement (12) in order to at least partially enclose a workpiece blank (18) when producing the cylindrical workpiece with a spiral-shaped outer contour; wherein the forming tool arrangement (12) is designed for radially deflecting the forming tools (46) in the direction of the central axis (22); wherein the forming tools (46) are each aligned with their forming side (64) in the direction of the central axis (22) in order to be able to cause a radial force to be introduced into the workpiece blank (18) by the radial deflection; wherein the first forming cam (72; 72a, 72b) of the first forming tool (46) is arranged together with one of the forming cams (72; 72a, 72b) of the second forming tool (46) on a first helical line (80).

11. Forming tool arrangement (12) according to claim 10, wherein the second forming cam (72; 72a, 72b) of the first forming tool (46) is arranged on the first helical line (80) or together with one of the forming cams (72; 72a, 72b) of the second forming tool (46) on a second helical line (82).

12. Forming tool arrangement (12) according to claim 10 or 11, wherein both forming cams (72; 72a, 72b) of the second forming tool (46) are arranged on the first helical line (80).

13. Forming tool arrangement (12) according to any of claims 10 to 12, additionally comprising at least one further forming tool (46) according to any of claims 1 to 9, wherein one of the forming cams (72; 72a, 72b) of the at least one further forming tool (46) is arranged on the first helical line (80) and / or the second helical line (82).

14. Forming tool arrangement (12) according to any of claims 10 to 13, wherein the forming tools (46) have a plurality of, preferably at least six, particularly preferably at least twelve, forming cams (72; 72a, 72b); wherein the first forming cams (72; 72a, 72b) of the forming tools (46) are arranged on different helical lines (80, 82); wherein the forming cams (72; 72a, 72b) of a forming tool (46) following in the longitudinal direction (74) of the first forming cam (72; 72a, 72b) are arranged on the helical lines (80, 82) of the further forming tools (46) alternating with the helical line (80, 82) of the same forming tool (46).

15. Forming machine (10) for the multi-stage production of a cylindrical workpiece with a spiral-shaped outer contour by rotary swaging, • having a forming tool arrangement (12) according to any of claims 10 to 14; • having a feed device (14) designed for arranging, in particular clamping, a workpiece blank (18); wherein the feed device (14) is designed to be translationally movable along a feed axis (20) relative to the forming tool arrangement (12); and • having a machine controller (34) designed to regulate machine parameters; • wherein the forming machine (10) is designed to carry out a relative rotational movement (30) between the forming tool arrangement (12) and the feed device (14).

16. Forming method for the multi-stage production of a cylindrical workpiece with a spiral-shaped outer contour by rotary swaging by means of a forming machine (10) according to claim 15, comprising the method steps of: • arranging, in particular clamping, a workpiece blank (18) on the forming machine (10); • producing the cylindrical workpiece with the spiral-shaped outer contour by moving the feed device (14) in an axial movement (29) along the feed axis (20) and simultaneously carrying out the relative rotational movement (30) between the forming tool arrangement (12) and the feed device (14); wherein the rotary movement (30) is adapted to the axial movement (29) such that the forming cams (72; 72a, 72b) along the screw lines (80, 82) cause plastic deformation of the workpiece blank (18) by radial deflection of the forming tools (46).

17. Forming method according to claim 16, wherein the cylindrical workpiece is produced from a hollow workpiece blank (18), wherein a forming mandrel is arranged within the hollow workpiece blank (18) before producing the cylindrical workpiece with the spiral-shaped outer contour.

18. Computer program for operating the forming machine (10) according to claim 15, wherein a numerical machine controller (34) is provided as the machine controller (34), wherein the computer program for the machine controller (34) comprises control instructions which cause a forming method according to claim 16 to be carried out when the computer program is running on the numerical machine controller (34) of the forming machine (10) according to claim 15.

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