EP2210682A1 - Method and apparatus for spinning - Google Patents

Abstract

The method involves arranging a tubular work piece around a pressure mandrel (20). The pressure mandrel is displaced by rotation, and is remodeled by feeding a shaping mandrel (40). Wall thickness of the tubular work piece is reduced, where the tubular work piece is lengthened. The pressure mandrel is displaced in the axial direction against the work piece during remodeling. An independent claim is also included for a flow form milling device.

Description

The invention relates to a method for ironing out according to the preamble of claim 1. The invention further relates to an apparatus for spin forming a tubular workpiece according to the preamble of claim 9.

In the known method, a tubular workpiece is arranged around a spinning mandrel, set in rotation and deformed by advancing at least one forming roller, wherein the workpiece is stretched. When ironing, the wall thickness decreases and the tubular workpiece is elongated by the displaced material.

Such a method is known from DE 43 07 775 A1 known. In this known method, the workpiece can be provided with a uniform inner contour, which is predetermined by the outer contour of the spinning mandrel.

The known device has a spinning mandrel, which can be arranged in the tubular workpiece, at least one forming roller for advancing and forming the workpiece and a rotary drive for rotationally driving the workpiece.

For the molding of undercuts in a tubular workpiece, it is for example from the DE 102 26 605 A1 it is known to do this by radially feeding a roller against a pusher cone. However, this so-called retraction is only appropriate at the outer edge of a pipe. In addition, the possible choice of shapes is also limited here.

From the DE 2 230 554 A For example, the use of split pushers to form an inner diameter reduction is known. The spinning mandrels are to produce in a complex manner for each workpiece shape. In this forming method and apparatuses correspondingly long spikes must be used for forming workpieces with a large length, resulting in high manufacturing and maintenance costs.

The object of the invention is to provide a method and a device, with which tubular workpieces can be economically rolled and with a great variety of shapes.

The object is achieved by a method having the features of claim 1 and by a device having the features of claim 9. Preferred embodiments are given in the respective dependent claims.

The inventive method is characterized in that the spinning mandrel is moved relative to the workpiece during the forming relatively in the axial direction.

The device according to the invention is characterized in that the spinning mandrel is mounted so as to be movable relative to the workpiece during the forming in the axial direction.

A basic idea of the invention can be seen not to mold the workpiece, as hitherto known, to a stationary mandrel, but to a mandrel moving under the workpiece. It is therefore sufficient to provide a spinning mandrel with a relatively short length, which in particular can be substantially less than the length of the workpiece to be machined. This considerably reduces the manufacturing and maintenance costs for the spinning mandrel. The inventive method is thus particularly economical and with a spinning mandrel different workpiece shapes can be produced.

The deformation is advantageously carried out by the use of at least two spinning rollers. The forming rollers are preferably distributed uniformly around the circumference of the workpiece or the spinning mandrel. Thus, undesirable transverse forces and thus deflection of the spinning mandrel can be avoided.

According to the invention, it is particularly preferred if a universal spinning mandrel with different outer diameters in the axial direction is used for producing differently shaped cylindrical and / or conical hollow parts. The spinning mandrel may also have different contours in the axial direction and is particularly funny. Also not rotationally symmetrical contours, such as polygons, possible. In this case, the term outer diameter is applied accordingly. Due to the variable outer diameter and / or the variable contours it is possible to provide a variable mandrel diameter during the ongoing forming process at the forming zone, ie the point of contact between forming roller, workpiece and spinning mandrel.

In an advantageous embodiment of the method is provided to perform the method in the opposite direction, wherein material of the workpiece flows counter to a feed direction of the forming rollers. The material flows during the forming process under the forming rollers and in the direction of a free spinning mandrel end and beyond. Longitudinal feed of the forming rollers and flow direction of the material are thus directed counter to each other. The flow rate of the material is due to the reduction of the wall thickness of the workpiece, which is pressed by the forming rollers axially against a clamping or holding device.

In a further advantageous embodiment of the method, it is provided that the method is carried out in synchronism, wherein material of the workpiece flows in the feed direction of the forming rollers. Longitudinal feed of the forming rollers and flow direction of the material thus take place in the same direction. The starting work piece for a forming process carried out in synchronism is preferably a round or cup-shaped workpiece, which is clamped between the spinning mandrel and a pressure element.

Furthermore, it is particularly advantageous if the forming rollers and the spinning mandrel are moved relative to the workpiece in the axial direction, wherein the forming rollers are moved relative to the pressing mandrel in the axial and / or radial direction to form variable diameter and / or wall thicknesses of the workpiece.

Due to the axial movement of the spinning rollers relative to the tool mandrel, the wall thickness or the inner diameter of the workpiece to be machined can be changed while the outside diameter remains the same.

To form variable outer diameter and / or wall thicknesses of the workpiece to be machined, the forming rollers are preferably moved relative to the spinning mandrel in the radial direction.

By the radial and / or axial displacement of the forming rollers relative to the spinning mandrel in conjunction with the variable outer diameter and / or the variable Overall contours of the spinning mandrel can be provided a variable mandrel diameter. In this case, different wall thicknesses can be produced on the workpiece. The forming rollers are delivered radially to the spinning mandrel taking into account the desired outer diameter and the desired wall thickness of the workpiece.

With the method according to the invention, in particular, long conical and / or cylindrical hollow parts, such as preforms for lampposts or flagpoles, can be produced in a particularly economical manner. Here, partially variable diameter and / or wall thicknesses can be formed in the workpieces, which can lead to a reduction in the weight of the products. In addition, the cross sections of the workpiece can be adapted to the expected loads and thus a particularly uniform stress distribution and thus a particularly favorable utilization of the material used can be achieved.

To form a workpiece section with a constant diameter and a constant wall thickness, the forming rollers are preferably moved at the same speed as the spinning mandrel relative to the workpiece. For this purpose, for example, the workpiece can be pressed or pulled between fixed forming rollers and fixed spinning mandrel. In this case, the movement of the workpiece takes place in the direction of a free, that is not clamped end of the spinning mandrel. Alternatively it can be provided to move forming rollers and spinning mandrel against a stationary workpiece. A combination of these two variants is possible.

A further preferred embodiment of the invention is given by the fact that the relative movement of the forming rollers in the axial and / or radial direction relative to the spinning mandrel in dependence on a relative position of the forming rollers relative to the spinning mandrel and in dependence on a predetermined gap between forming rollers and spinning mandrel by means of a Mess - And control device is controlled. In other words, the control of the forming rollers and / or the spinning mandrel in dependence on the desired diameter and the desired wall thickness of the workpiece section to be machined, which are determined by the relative position between forming rollers and spinning mandrel. Furthermore, preferably the length and / or the wall thickness of the workpiece to be machined are measured and these values processed as input variables in the measuring and control device. This means that uniform end products can be manufactured from original workpieces with dimensional deviations.

A particularly advantageous embodiment of the method is given by the fact that the workpiece is clamped to a chuck, which is rotatably mounted and driven, and that the spinning mandrel is moved axially relative to the chuck. The workpiece is thus set over the chuck in rotation. At the same time, a rotation of the spinning mandrel preferably takes place at the same rotational speed, wherein the spinning mandrel is moved axially during the deformation relative to the chuck. Since it only depends on a relative movement between the workpiece, spinning mandrel and forming roller, it can also be provided that the chuck is moved relative to a fixed spinning mandrel.

In the device according to the invention, it is preferred that the spinning mandrel has different outer diameters, in particular has a conical, cylindrical and / or cambered shape. Due to the different outer diameter or the conical shape, a variable spinning mandrel with a variable spinning mandrel diameter is provided. Here, a relative axial feed of the forming rollers relative to the spinning mandrel and a delivery of the forming rollers is relatively radially to the corresponding diameter of the spinning mandrel, taking into account the desired gap between forming rollers and spinning mandrel. This forming gap determines the wall thickness of the workpiece.

The spinning mandrel may also have other geometric shapes, such as cylindrical and / or conical heels, radius transitions, profiles, such as ribs or grooves, or other cross-sections, such as polygons, hexagonal, ellipses or polyons. Other geometric configurations are possible.

By dispensing with a long full mandrel, which is at least as long as the workpiece to be machined, there are significant advantages. Thus, the inventive method for variable workpiece diameter and / or variable wall thicknesses can be advantageously used on a workpiece. By means of the spinning mandrel according to the invention, which can also be referred to as a short mandrel, the tool costs and the costs for the maintenance of the spinning mandrel are considerably reduced. Also the weight of the spinning mandrel is reduced compared to a full mandrel, whereby the flexibility of the machine is significantly improved.

Another suitable embodiment of the invention is that the spinning mandrel has inner rollers on its outer circumference. At the periphery of the spinning mandrel preferably at least two stored inner rollers are evenly distributed and arranged rotatably. The inner rollers are rotatable about their own axis, but non-rotatable relative to a longitudinal axis of the spinning mandrel. Preferably, associated forming rollers are provided, for example in a corresponding number, which interact with the inner rollers. This results in pairs of rollers, which are formed from forming roller and inner roller. Between each of the roller pairs, a zone of the plastic material state is generated on the workpiece from outside and inside. This results in a division of the roller forces and the forming work. The forming work is distributed over twice the number of rolls. Through the use of inner rollers thus the forming speed can be increased. By a symmetry in the forming zone, a residual stress state in the spin-rolled workpiece is greatly reduced.

The forming rollers, which can also be referred to as outer rollers, are preferably axially and / or radially displaceable or displaceable. As a result, different forming tasks, for example, different diameters and / or wall thicknesses can be performed. Likewise, a gap adjustment can be made by axial displacement of the spinning mandrel.

Of particular importance in the flow-forming technique is the roll diameter. It depends on the wall thickness to be rolled and the workpiece diameter. Preferably, inner rollers and outer rollers have the same diameter. A difference in diameter of about 30% should not be exceeded.

A further preferred embodiment of the device according to the invention is that the rotary drive with a chuck for clamping the workpiece and / or a support with at least two forming rollers relative to a machine bed is axially movable. With the method of rotary drive, an axial displacement of the workpiece relative to the machine bed can be achieved. A structural design may consist in that the rotary drive is mounted on a headstock, which is axially movable relative to the machine bed. By moving the headstock or the rotary drive is thus about the chuck moved axially clamped workpiece. Additionally or alternatively, the support with the forming rollers relative to the machine bed can be axially movable. In this case, it is possible that the rotary drive is fixedly arranged on the machine bed.

To achieve the relative radial and / or axial delivery of the forming rollers can be provided that the forming rollers are arranged radially and / or axially movable on the support. Also, the angle of attack to the axis of rotation of the workpiece can be changed. The support itself can be fixed or displaceable on the machine bed. The storage of the forming rollers on the support with the radial and / or axial mobility causes a compact design of the device. The forming rollers may have a suitable shape, such as cylindrical or conical. The forming rollers can also have contours for optimal forming.

A further preferred embodiment of the invention is given by the fact that the spinning mandrel is axially movable relative to the chuck. It is particularly preferred if the spinning mandrel is rotatably drivable together with the chuck and / or the workpiece. This can be achieved, for example, by means of a keyway profile between spinning mandrel and chuck. Due to the possibility of an axial displacement between spinning mandrel and chuck, the relative movement of the spinning mandrel according to the invention relative to the workpiece is achieved in a simple and reliable manner.

For a reliable deformation by means of the device according to the invention, it is particularly preferred that a measuring and control device for measuring a length and / or wall thickness and / or diameter of the workpiece and for controlling a radial movement of the forming rollers and / or a relative axial movement the forming rollers is provided opposite the spinning mandrel.

The inventive method is based entirely on relative movements between spinning mandrel, workpiece and forming rollers. These elements must be moved in harmony with each other and depending on the desired forming. For this purpose, a measuring and control device is arranged according to the device. This measures current geometric parameters, such as position, length and diameter of the workpiece, and controls the movement of said elements to each other on this basis.

A particularly economical device is achieved in that a feed rod is provided, which is connected to the spinning mandrel and has a diameter which is as small as possible to the maximum diameter of the spinning mandrel, and that an axial drive is provided for moving the feed rod. In principle, the feed rod can also be arranged axially stationary, in which case it only has the function of an extension or intermediate rod, which is arranged between the spinning mandrel and a bearing or attachment.

One function of the feed rod is to provide a spacer between the spinning mandrel and its machine-side clamping. At the beginning of the forming process, the workpiece can be arranged around the feed rod. During the forming takes place a relative movement between the workpiece and the spinning mandrel, wherein the workpiece moves in the direction of the free end of the spinning mandrel.

The rotation of the spinning mandrel with the feed rod can be done by friction between Umformrolle, workpiece and spinning mandrel. Between the spinning mandrel and feed rod, a print head can be provided, which ensures a rotational decoupling between spinning mandrel and feed rod. In this embodiment, only an axial feed for the spinning mandrel is required.

It can also be provided that the spinning mandrel and / or a variable inner roller can be axially displaced via a CNC axis or by pressure, for example a hydraulic cylinder, in order to achieve a gap adjustment with the spinning mandrel, ie a change in the wall thickness on the workpiece. This was previously only possible by a radial adjustment of the forming rollers.

The relative movement between the workpiece and spinning mandrel can be done by an absolute movement of the workpiece relative to a fixed spinning mandrel and / or an absolute movement of the spinning mandrel. The absolute movement of the spinning mandrel is preferably achieved by an axial movement of the feed rod, to which an axial drive is provided.

Fig. 1

ein erstes Ausgangswerkstück;

Figuren 2 bis 7

Umformschritte gemäß einer ersten Ausgestaltung des erfin- dungsgemäßen Verfahrens als Gegenlauf-Drückwalzverfahren;

Fig. 8

ein Werkstück nach Umformung;

Fig. 9

eine erste Ausführungsform eines Drückdorns;

Fig. 10

ein zweites Ausgangswerkstück;

Figuren 11 bis 16

Umformschritte gemäß einer zweiten Ausgestaltung des erfin- dungsgemäßen Verfahrens als Gegenlauf-Drückwalzverfahren;

Fig. 17

ein zweites Werkstück nach Umformung;

Fig. 18

eine zweite Ausführungsform eines Drückdorns;

Fig. 19

einen Umformschritt gemäß einer dritten Ausgestaltung des erfin- dungsgemäßen Verfahrens als Gegenlauf-Drückwalzverfahren;

Figuren 20 bis 21

ein umgeformtes Werkstück;

Fig. 22

eine dritte Ausführungsform eines Drückdorns;

Fig. 23

ein weiteres Ausgangswerkstück;

Figuren 24 bis 26

Umformschritte zur Umformung des in Fig. 23 gezeigten Werk- stücks im Gegenlauf-Drückwalzverfahren;

Figuren 27 bis 28

ein umgeformtes Werkstück;

Fig. 29

eine weitere Ausführungsform eines Drückdorns;

Fig. 30

ein weiteres Ausgangswerkstück;

Figuren 31 bis 39

Umformschritte gemäß einer weiteren Ausgestaltung des erfin- dungsgemäßen Verfahrens als Gegenlauf-Drückwalzverfahren;

Figuren 40 bis 41

ein umgeformtes Werkstück;

Fig. 42

eine weitere Ausführungsform eines Drückdorns;

Fig. 43

ein weiteres umgeformtes Werkstück;

Figuren 44 bis 47

Umformschritte zur Herstellung eines Katalysatorgehäuses;

Fig. 48

eine weitere Ausführungsform eines Drückdorns;

Fig. 49

eine Umformung mittels einer Mehrbereichs-Umformrolle;

Fig. 50

eine Mehrbereichs-Umformrolle;

Fig. 51

einen Umformschritt mittels eines Drückdorns mit Innenrollen;

Fig. 52

ein napfförmiges Ausgangswerkstück;

Figuren 53 bis 57

Umformschritte gemäß einer Ausgestaltung des erfindungs- gemäßen Verfahrens als Gleichlauf-Drückwalzverfahren;

Fig. 58

ein umgeformtes Werkstück;

Fig. 59

eine Seitenansicht einer Vorrichtung zum Drückwalzen;

Fig. 60

eine Querschnittsansicht aus Fig. 59;

Fig. 61

eine zweite Vorrichtung zum Drückwalzen.

The invention will be further described by means of preferred embodiments, which are shown schematically in the drawings. Herein show:

Fig. 1

a first parent workpiece;

FIGS. 2 to 7

Forming steps according to a first embodiment of the inventive method as a countercurrent flow-forming process;

Fig. 8

a workpiece after forming;

Fig. 9

a first embodiment of a spinning mandrel;

Fig. 10

a second parent workpiece;

FIGS. 11 to 16

Forming steps according to a second embodiment of the inventive method as a countercurrent flow-forming process;

Fig. 17

a second workpiece after forming;

Fig. 18

a second embodiment of a spinning mandrel;

Fig. 19

a forming step according to a third embodiment of the inventive method as a countercurrent flow-forming process;

FIGS. 20 to 21

a formed workpiece;

Fig. 22

a third embodiment of a spinning mandrel;

Fig. 23

another initial work piece;

FIGS. 24 to 26

Forming steps for forming the in Fig. 23 shown workpieces in the counter-rotating flow-forming process;

FIGS. 27 to 28

a formed workpiece;

Fig. 29

a further embodiment of a spinning mandrel;

Fig. 30

another initial work piece;

FIGS. 31 to 39

Forming steps according to a further embodiment of the inventive method as a countercurrent flow-forming process;

FIGS. 40 to 41

a formed workpiece;

Fig. 42

a further embodiment of a spinning mandrel;

Fig. 43

another formed workpiece;

FIGS. 44 to 47

Forming steps for producing a catalyst housing;

Fig. 48

a further embodiment of a spinning mandrel;

Fig. 49

a deformation by means of a multi-area forming roller;

Fig. 50

a multigrade forming roll;

51

a forming step by means of a spinning mandrel with inner rollers;

Fig. 52

a cup-shaped starting workpiece;

FIGS. 53 to 57

Forming steps according to an embodiment of the inventive method as a synchronous flow-forming method;

Fig. 58

a formed workpiece;

Fig. 59

a side view of a device for spin forming;

Fig. 60

a cross-sectional view Fig. 59 ;

Fig. 61

a second apparatus for spin forming.

FIGS. 1 to 9 show in a schematic way a first embodiment of the method according to the invention.

Fig. 1 shows a first tubular workpiece 10, which is provided as a starting workpiece for forming. The workpiece 10 has a circular cross-section with an outer diameter D0 and a wall thickness S0. FIGS. 2 to 7 show forming steps of the forming of the workpiece 10 into a conical hollow body, which in Fig. 8 is shown. For forming a spinning mandrel 20 is used, which Fig. 9 shows.

The spinning mandrel 20 is a rotationally symmetrical body and has a longitudinal axis. The longitudinal axis forms an axis of rotation of the spinning mandrel 20 about which the spinning mandrel 20 is rotatably mounted. On the right side in the figures, the spinning mandrel 20 has a free end 22, while on the left side, a connecting end 24 is formed, via which the spinning mandrel 20 connected to a Maschineneinspannung and optionally driven. A fundamental aspect of the spinning mandrel 20 according to the invention is that a diameter of the spinning mandrel does not decrease from the free end 22 in the direction of the connecting end 24, but is either constant or increases. The spinning mandrel 20 has a cone section 26 and a cylinder section 28. The cone portion 26 is formed as a truncated cone, wherein the end with the smallest diameter forms the free end 22 of the spinning mandrel 20. At the connection end 24, so the opposite end of the free end 22 of the spinning mandrel 20, a feed rod 34 is arranged. The feed rod 34 has at least one cylindrical portion 36 and is formed in the illustrated embodiment as a solid cylinder. A diameter of the feed rod 34, in particular of the cylindrical portion 36 of the feed rod 34, is preferably less than a diameter of the cylindrical portion 28 of the spinning mandrel 20. The feed rod 34 may be integrally formed with the spinning mandrel 20 or be releasably connected as a separate element with the spinning mandrel 20 , The spinning mandrel can be changed in this way.

Around the outer circumference of the spinning mandrel 20 around a plurality of forming rollers 40 are uniformly distributed. Fig. 2 shows two forming rollers 40, wherein, for example, three or four forming rollers 40 may be arranged. The forming rollers 40 are rotationally symmetrical body and frusto-conical in the illustrated embodiment. The forming rollers 40 are rotatably mounted about a rotation axis 42 around, wherein the rotation axis 42 is a longitudinal axis of the truncated cone. The axes of rotation 42 of the forming rollers are aligned obliquely to a longitudinal axis 32 of the spinning mandrel 20.

In the case of the counterrotation method described below, it is fundamentally provided that the workpiece 10 is clamped on the spindle head side in a non-machined region during the forming process.

A first method step of forming the workpiece 10 is shown in FIG Fig. 2 shown. The workpiece 10 is first arranged around the spinning mandrel 20 and the feed rod 34. In the illustrated method stage, a first axial region 11 of the workpiece 10 is arranged around the feed rod 34, wherein between the workpiece 10 and the feed rod 34, an annular space 38 is formed. A second, central axial region 12 of the workpiece 10 is around the cylinder section 28 of the spinning mandrel 20 arranged. In this case, the workpiece 10 bears against an outer peripheral surface of the cylinder section 28. A third axial region 13 of the workpiece 10 is arranged around a first subsection of the cone section 26 of the spinning mandrel 20.

The forming rollers 40 are in the in Fig. 2 shown process stage axially spaced from the workpiece 10 about a second portion of the cone portion 26 of the spinning mandrel 20 and do not contact the workpiece 10.

Drückdorn 20 and workpiece 10 are, preferably at the same peripheral speed, set in rotation. The forming rollers 40 are delivered radially in the direction of the spinning mandrel 20 and moved axially in the direction of the workpiece 10.

In a second process step, which in Fig. 3 is shown, a cone portion 14 is formed at the end of the workpiece 10. For this purpose, the forming rollers 40 and the spinning mandrel 20 are moved axially with the same axial speed relative to the workpiece 10. In this case, only a relative movement is important, so that the workpiece 10 can also be moved relative to the spinning mandrel 20 and the forming rollers 40. The forming rollers 40 contact an outer peripheral portion of the workpiece 10 and are rotationally engaged with the workpiece 10 in rotational motion. As a result of the axial movement of forming rollers 40 and spinning mandrel 20 relative to the workpiece 10, an axial end region of the workpiece 10 is formed on an outer circumference of the forming rollers 40 and drawn into the cone area. In the process, the workpiece 10 does not first contact the spinning mandrel 20 with its conical region 14, but only the forming rollers 40. During the drawing in, substantially no wall thickness reduction of the workpiece 10 takes place.

At the end of this process step is a process stage in which an axial end of the workpiece 10 is applied to the spinning mandrel 20, that is clamped between the spinning mandrel 20 and forming rollers 40. At the axial end, the workpiece 10 has an inner diameter D1, which corresponds to an outer diameter of the spinning mandrel 20 at this axial point. This procedural stage is in Fig. 4 shown.

With increasing feed of the forming rollers 40 in the axial direction then begins as the third process step, the actual Abstreckdrückwalzen, which can also be referred to as cone-pressure rollers and in the FIGS. 5 to 7 is shown. In the cone-spinning, the workpiece 10 is attached to the cone portion 26 of the spinning mandrel 20 formed as in Fig. 5 shown. In this case, there is a continuous adjustment of the forming rollers 40 in the radial direction during the forming. The previously drawn-in cone area 14 is stretched by the initiated flow-forming operation, wherein a reduction of the wall thickness of the workpiece 10 takes place. Simultaneously with the axial feed of the forming rollers 40, a relative axial displacement of the spinning mandrel 20 takes place to the forming rollers 40. The forming rollers 40 are relatively axially relative to the spinning mandrel 20 in the direction of an increasing diameter of the spinning mandrel 20. As a result, an increasing diameter is formed on the workpiece 10.

Due to the direct action of pressure, a zone of the plastic material state forms under the forming rollers 40, in which the wall thickness of the workpiece 10 is reduced, as in FIG Fig. 6 shown. The displaced material flows mainly in the direction of the free end 22 of the spinning mandrel 20, ie counter to the feed direction of the forming rollers 40. The wall thickness reduction causes an increase in length of the workpiece 10th

The forming rollers 40 are relatively axially moved relative to the spinning mandrel 20 up to the desired maximum outer diameter of the workpiece 10. Fig. 7 shows a stage of the process in which the forming rollers 40 have reached the cylinder portion 28 of the spinning mandrel 20. With further axial and radial feed of the forming rollers 40, a termination of the contact between forming rollers 40 and workpiece 10 and the flow-forming operation is terminated.

With the illustrated method, an in Fig. 8 shown workpiece 10, which is a conical hollow body produced. The conical hollow body has at one axial end the small inner diameter D1 (see. Fig. 4 ) and at an opposite end a large inner diameter. The small inner diameter D1 corresponds to at least a minimum diameter of the cone portion 26 of the spinning mandrel 20. The large diameter is at most equal to a diameter of the cylindrical portion 28 of the spinning mandrel 20. Due to the relative axial displacement of the spinning mandrel 20 relative to the workpiece 10, the conical hollow body has a different conicity on than the cone portion 26 of the spinning mandrel 20th

FIGS. 10 to 18 show a second embodiment of the method according to the invention. Herein shows Fig. 10 shows a second tubular workpiece 10a, which as Starting workpiece is intended for forming. The workpiece 10a has an inner profile which comprises a plurality of longitudinal ribs 15 formed on an inner side of the workpiece. In the remaining dimensions, the workpiece 10a corresponds to the in FIG. 1 illustrated workpiece 10th FIGS. 11 to 16 show forming steps for forming the workpiece 10a. Fig. 17 shows the workpiece 10a as a finished forming part after forming. In Fig. 18 a spinning mandrel 20 is shown, which is formed as a profiled spinning mandrel 20a and is used in the method.

Unlike the in Fig. 9 shown spinning mandrel 20 has the profiled spinning mandrel 20a according to Fig. 18 on its outer surface longitudinal grooves 21. The longitudinal grooves 21 extend both along the cylinder portion 28 and along the cone portion 26 of the spinning mandrel and correspond to the cylinder portion 28 in terms of number and arrangement of the longitudinal ribs 15 of the workpiece 10 a. At the cone portion 26, the longitudinal grooves 21 are conical.

The workpiece 10a is slid onto the profiled spinning mandrel 20a and reshaped in a manner analogous to the previously described method. The in the FIGS. 11 to 17 shown process steps correspond substantially to those in the FIGS. 2 to 7 shown method steps. The profile of the spinning mandrel 20 is made larger in accordance with the volume fractions of the pipe profile, taking into account the reduction in diameter by the flow-forming process. In Fig. 17 is a formed workpiece 10a shown as the final shape of the deformation, which is different from the in Fig. 8 essentially differs in that an inner profile is formed on its inner surface, the parallel and tapered inner ribs 16 includes. The inner profile can thus be referred to as a cylindrical and conical inner profile. The deformed workpiece 10a according to Fig. 17 has a wall thickness S1, which is less than the wall thickness S0 of the starting workpiece.

A third embodiment of the method according to the invention is in the FIGS. 19 to 22 shown. Starting workpiece is a tubular workpiece 10, as in Fig. 1 shown. Fig. 19 shows a process step of the forming. The workpiece 10 is as a finished forming part in Fig. 20 in perspective view and in Fig. 21 shown in plan view from the front or in cross section. Fig. 22 shows as a spinning mandrel 20 a profiled spinning mandrel 20a.

The in Fig. 22 shown profiled spinning mandril 20a substantially corresponds to the in Fig. 18 represented profiled spinning mandrel 20a.

The transformation takes place in basically the same way as in connection with FIGS. 1 to 9 described. In contrast to this, material of the workpiece 10 is introduced into the longitudinal grooves 21 of the profiled pressing mandrel 20a during the spin-rolling. As a result of the compressive stress in the forming zone, ie the zone of the plastic material state, material also flows in the radial direction and preferably completely fills the groove cross-section. At the same time there is an axial flow of material, in particular at the non-grooved mandrel areas. This can be promoted by an appropriately adapted to the geometry of the spinning mandrel Umformrollengeometrie.

A conical and / or cylindrical inner profile can be produced not only in long hollow parts, such as masts, but also in short hollow parts, such as gear parts with teeth, such as clutch plate carriers.

FIGS. 23 to 29 show a fourth embodiment of the method according to the invention. In this method, a tubular workpiece 10, as in Fig. 23 represented formed in a formed as a hollow shaft or cylinder tube workpiece 10 with at least one hexagon socket portion 60 and at least one cylindrical portion 62. FIGS. 24 to 27 show process steps for forming the workpiece 10. A workpiece 10 as finished machined forming part is in Fig. 28 shown.

As a spinning mandrel 20 is a as in Fig. 29 shown multi-range mandrel 20b used. This has a hexagonal section 25, a cylindrical section 28 and a cone section 26 arranged between them. The hexagonal portion 25 has a diameter which is smaller than a diameter of the cylinder portion 28. The cone portion 26 mediates between the hexagonal portion 25 and the cylinder portion 28 and has at least one slope 27 in which a diameter increases.

The forming rollers 40 used for forming have two conical sections 44, 46, which are opposite to each other. A lead-in angle is defined by a first conical section 44, a second conical section 46 defines a smoothing angle. Between the two conical sections 44, 46 of the forming radius R is educated. The conical sections 44, 46 have a common longitudinal axis 48, which forms an axis of rotation of the respective forming roller 40. In contrast to the previous embodiments, the axes of rotation of the forming rollers 40 are aligned parallel to the longitudinal axis 32 of the spinning mandrel.

The tubular workpiece 10 is arranged around the spinning mandrel 20. In a first forming step, a first hexagonal area 60 is formed on the workpiece. This has a cylindrical outer lateral surface and a hexagonal inner lateral surface. To form the hexagonal area 60 with a cylindrical outer circumferential surface, the forming rollers 40, together with the spinning mandrel 20, are moved axially relative to the workpiece 10, with no axial and radial relative movement between the forming rollers 40 and the spinning mandrel 20. As already described, the workpiece relative to forming rollers and spinning mandrel can be moved relatively.

In a second forming step, a conical transition region 61 is formed in that the forming rollers in the region of the cone portion 26 of the spinning mandrel 20 are relatively moved axially and radially relative to the spinning mandrel 20.

Subsequently, the workpiece is further stretched in a third forming step, forming a first cylindrical portion 62 having a larger diameter than a diameter of the first hex portion 60.

In a fourth method step, a second transition region 63 is formed, in which a diameter of the workpiece 10 decreases starting from the cylindrical region 62. For this purpose, the forming rollers 40 are moved relative to the spinning mandrel 20 axially in the direction of the free end 22 of the spinning mandrel 20 and delivered radially. The shaping of the second transition region 63 thus takes place in reverse order of movement to the formation of the first transition region 61.

Subsequently, in a fifth forming step, a second hexagonal area 64 is formed by further stretching of the workpiece 10. This has a smaller diameter than a diameter of the first cylindrical portion 62.

Finally, in an analogous manner to the formation of the first transition region 61 and the first cylindrical region 62, a termination region 65 is formed which comprises a third transition region 66 and a second cylindrical region 67.

A fifth embodiment of the method according to the invention is in the FIGS. 30 to 43 shown. This will be an in Fig. 30 shown tubular workpiece 10 in a formed as a cylindrical hollow part with an undercut formed workpiece 10, as exemplified in Fig. 40 and Fig. 41 is shown. The deformation takes place by means of a spinning mandrel 20, which in Fig. 42 is shown. The spinning mandrel 20 corresponds to its basic structure in the Fig. 9 shown spinning mandrel 20, wherein the length ratios of cylinder portion 28 and cone portion 26 and the taper of the cone portion 26 are changed and adapted to the forming task.

The forming rollers 40 used for forming are basically constructed in the same way as those associated with the in FIGS. 23 to 29 described forming rollers 40th

The tubular workpiece 10 is placed around the spinning mandrel 40, Fig. 31 , In a first in Fig. 32 shown forming step is retracted by axial movement of the forming rollers 40 relative to the workpiece 10 and the spinning mandrel 20, an end portion of the workpiece 10. Subsequently, a first cylindrical portion 70 is formed with a diameter D1 and a wall thickness S1, cf. Fig. 40 , The diameter D1 is smaller than the diameter D0 of the starting workpiece. Likewise, the wall thickness S1 is less than the wall thickness S0 of the starting workpiece. To form the first cylindrical portion 70, forming rollers 40 and spinning mandrel 20 are moved axially at the same axial speed relative to the workpiece 10, as in FIG Fig. 33 shown.

Fig. 34 shows a second forming step. In this, a conical transition region 71 is formed in that the forming rollers 20 in the region of the cone portion 26 of the spinning mandrel 20 axially and radially relative to the spinning mandrel 20 are moved.

Subsequently, the workpiece 10 in a third forming step, which in Fig. 35 is illustrated, further strung. Here, a second cylindrical portion 72 is formed, which has a diameter D2 which is greater than the diameter D1 of the first cylindrical portion 70th

Fig. 36 shows a fourth method step. In this, a second transition region 73 is formed, in which a diameter of the workpiece 10, starting from the second cylindrical portion 72 decreases. For this purpose, the forming rollers 40 are moved relative to the spinning mandrel 20 axially in the direction of the free end 22 of the spinning mandrel 20 and delivered radially. The shaping of the second transition region 73 thus takes place in reverse order of movement to the formation of the first transition region 71.

Subsequently, in a fifth forming step, a third cylindrical region 74 with a diameter D3 is formed by further stretching of the workpiece 10. The diameter D3 is less than the diameter D2 of the second cylindrical portion 72, such as Fig. 40 can be seen. This forming step is in Fig. 37 shown.

Figures 38 and 39 show further method steps in which a third transition region 75 and a fourth cylindrical region 76 with a diameter D4 are formed in a manner analogous to the first transition region 71 and the second cylindrical region 72.

Finally, a termination region 77 is formed which comprises a fourth transition region 78 and a fifth cylindrical region 79. The fifth cylindrical portion 79 has the diameter D0 of the starting workpiece and the wall thickness S0 of the starting workpiece.

With the method, it is possible in a simple manner to form almost any wall thicknesses and diameters in a particularly economical manner. In Fig. 40 a workpiece is shown which has a plurality of axial regions with different wall thicknesses S0 to S4, the original wall thickness of the starting workpiece S0 being present only in the last-formed end region. This in Fig. 40 shown workpiece is in Fig. 41 shown in perspective view.

Fig. 43 shows a further workpiece which has been formed by means of the method according to the invention. The workpiece has a compensation region 19, which is formed in a central region of the workpiece. The compensation area can be provided to compensate for dimensional variations of the starting workpiece by displacing excess material into the compensation area 19 or possibly removing missing material therefrom.

This in Fig. 43 shown workpiece 10 has a substantially constant outer diameter, wherein in the compensation area 19 an increased wall thickness, therefore there is a reduced inside diameter. The workpiece 10 can be produced with the method according to the invention in a particularly simple and cost-effective manner.

FIGS. 44 to 48 show a sixth embodiment of the method according to the invention. Here, a catalyst housing 50 is made in a single set of a rounded, longitudinally welded ring or a seamless tube.

An objective of this method is to adapt a catalytic converter housing 50 precisely to the outer dimensions of a ceramic carrier body 52. This is based on the knowledge that the outer dimensions of the carrier body 52 strongly scatter from lot to lot. As a result, support bodies 52 with oversize in the housing are loose, while support bodies 52 can cause defects with oversize. With the method according to the invention, the dimensions of the catalyst housing 50 can be adapted to the carrier body 52, so that an optimal fit of the carrier body 52 in the catalyst housing 50 is achieved.

In the method, a spinning mandrel 20 is used, which in Fig. 48 is shown. The spinning mandrel 20 has an end-side first cylinder section 28a. Adjacent thereto, a first cone section 26a is formed, wherein a rounded transition section 29 is formed between the first cylinder section 28a and the first cone section 26a. Adjacent to the first cone section 26a, a second cone section 26b is formed which has a smaller conicity than the first cone section 26a. In other words, the second cone portion 26b is flatter than the first cone portion 26a, so the diameter increases less rapidly per unit length. The second cone section 26b is followed by a second cylinder section 28b, which has a larger diameter than the first cylinder section 28a. Finally, adjacent to the second cylinder portion 28b, a feed rod 34 is integrally formed with the spinning mandrel 20 having a smaller diameter than the second cylinder portion 28b.

In a first process step, which in Fig. 44 is shown, the workpiece 10 is arranged around the spinning mandrel 20.

Fig. 45 shows a second method step in which a first nozzle 54 of the catalyst housing 50 is formed. In this case, an end region of the workpiece 10 is pressed against an outer surface of the spinning mandrel 20 and / or spin-rolled.

In a third method step, an outer diameter of a carrier body 52 or ceramic inner part to be inserted into the catalyst housing 50 is measured by a measuring device. This measured value is transmitted to a control device and optionally processed with the previously measured inner diameter and / or the previously measured wall thickness of the workpiece. By the control device, a movement of the forming rollers 40, the spinning mandrel 20 and / or the workpiece 10 is controlled. In particular, in this case, an inner diameter of the workpiece 10 is adjusted or controlled by axial displacement of the forming rollers 40 relative to the spinning mandrel 20 and thus the workpiece 10 is accurately stretched to the desired inner diameter. For a particularly sensitive control while the second cone portion 26b is provided, which has a flat slope. During the forming, a free end of the workpiece 10 may be held in a centering or clamping device.

In a fourth method step, the spinning mandrel 20 is completely removed from the workpiece 10 and the carrier body 52 or the ceramic inner part is used.

In a fifth method step, a second nozzle 56 of the catalyst housing or a terminal end is finally formed.

A seventh embodiment of the method according to the invention is in Figures 49 and 50 shown. Fig. 49 shows a forming step with a multi-range forming roller 40a, which may also be referred to as a multi-range roller. An enlarged view of the multiscale roller is shown in FIG Fig. 50 shown.

With the multigrade forming roller 40a or multi-range roller, the forming speed when drawing cylindrical hollow parts can be increased. The multigrade forming roller 40 a has a roller profile with at least two deformation radii 41 and at least one ironing radius 43. By means of these at least three radii, the workpiece 10 can be deformed simultaneously at several points. Before and behind the Umformradien 41 a wave trough 45 is arranged in each case. The troughs 45 serve to reduce a contact area between the multigrade forming roller 40a and the workpiece 10. Furthermore, the troughs 45 may be used to introduce lubricating and cooling fluid between the multigrade forming roller 40a and the workpiece 10 to achieve a reduction in friction. In the area of the largest diameter of the multigrade forming roller 40a, which is the opening diameter can be designated, a hold-down surface 47 is arranged to prevent beading on the workpiece 10. Behind the Abstreckradius 43 is followed by a smoothing surface 49 for smoothing the workpiece 10 at. The smoothing surface 49 opens into a clearance angle 49a.

The absolute values of the radii and working angles depend on the material and must be determined experimentally.

51 shows an eighth embodiment of the method according to the invention. Shown is a forming step with a two or more inner rollers 39 having spinning mandrel. The inner rollers 39 are evenly distributed around the circumference of the spinning mandrel 20 and there rotatably supported about its own axis. With regard to a longitudinal axis 32 of the spinning mandrel, the inner rollers 39 are non-rotatable. The inner rollers 39 are arranged without axial and radial misalignment.

The number of inner rollers 39 is dependent on the inner diameter of the workpiece 10. In 51 two inner rollers 39 are shown; but it can also be provided 39 three, four or more inner rollers. The outer rollers or forming rollers 40 correspond in number and pitch to the inner rollers 39, which act as a working pair and reshape.

An eighth embodiment of the method according to the invention is in the FIGS. 52 to 58 shown. This embodiment relates to the forming of a workpiece in the synchronous flow-forming process. Starting workpiece may be a cylindrical or conical preform. Fig. 52 shows a cup-shaped starting workpiece 10. The workpiece 10 has a cylinder jacket 17 and a bottom portion 18.

The spinning mandrel 20 is designed as a hollow mandrel, in which an inner mandrel 23 is arranged. Drückdorn 20 and inner mandrel 23 are axially displaceable relative to each other.

In Fig. 53 the workpiece 10 between the inner mandrel 23 and a pressure element 8, for example, a Ausstoßerscheibe, rotatably clamped. The cylinder jacket 17 of the workpiece 10 rests loosely on the spinning mandrel 20. The spinning mandrel 20 has, according to the previous embodiments, a cone section 26 and a cylinder section 28.

A forming roll 40 is positioned near the transition from cone section 26 to cylinder section 28. As a first method step, a part of the cylinder jacket 17 of the workpiece 10 is pulled in a controlled manner. Due to the direct action of pressure, a zone of the plastic material state is formed between the forming roller 40 and the spinning mandrel 20, in which the wall thickness is reduced. The displaced material flows in the direction of the axial feed of the forming roller 40. The forming roller 40 is thereby delivered radially and axially. The spinning mandrel 20 is retracted in the axial direction to a constantly decreasing diameter.

Fig. 54 shows an intermediate stage of this forming process.

In Fig. 55 is the Einziehumformvorgang finished. The retracted workpiece area is now resting on the spinning mandrel 20.

In Fig. 56 a further process step is shown, in which the workpiece 10 is stretched onto the inner mandrel 23 cylindrically in the co-rolling rollers. Here, the forming rollers 40 and the spinning mandrel 20 are moved axially. The workpiece 10 is formed between forming rollers 40 and spinning mandrel 20.

In Fig. 57 It can be seen that a further portion of the workpiece 10 between the forming roller 40 and spinning mandrel 20 is stretched in the co-rolling rollers and in the course of an enlarged opening diameter is formed.

A finished formed workpiece 10 is in Fig. 58 shown.

Fig. 59 shows an inventive device 80 for counter-rolling rollers. The apparatus 80 includes a machine bed 82, a headstock 84 and a support 86. The headstock 84 is axially displaceable relative to the machine bed 82. For axial displacement of the headstock 84, a headstock drive 88 is provided.

On the spindle box 84, a spinning mandrel 20 is mounted axially displaceable with respect to the headstock 84 and with respect to the machine bed 82. In an axial extension of the spinning mandrel 20, a feed rod 34 is arranged, which is connected to the spinning mandrel 20 via a print head 90. The print head 90 is disposed between the feed rod 34 and the spinning mandrel 20 and causes a rotational decoupling between the feed rod 34 and spinning mandrel 20. As soon as the forming rollers 40 the Press workpiece 10 on the spinning mandrel 20, the spinning mandrel 20 is offset by frictional engagement between forming roller 40 and workpiece 10 in rotation. The print head 90 prevents the feed rod 34 from rotating. At the end of the feed rod 34 for axial displacement of the spinning mandrel 20 and the feed rod 34, an axial drive 92 is arranged with rotation.

The workpiece 10 is clamped on the spindle head side by a chuck 94. Between headstock 84 and support 86 and also behind the support 86 Lynetten 96 may be arranged to support the workpiece 10. The device 80 further includes a Z-axis drive 98 for advancing the headstock 84 in the axial direction.

With the device 80, the clamped on the headstock 84 workpiece 10 can be moved axially by axial movement of the headstock 84. This is particularly advantageous in the processing of long workpieces 10, for example for the production of lampposts, and shortens the overall construction length of the device 10.

Fig. 60 shows a cross-sectional view through the in Fig. 52 illustrated device 80 along the section line AA. On the support 86 four driven forming rollers 40 are arranged radially along each of a radial axis 87 and axially along an axial axis relatively movable to the spinning mandrel 20 and a main spindle. The support 86 is fixedly connected to the machine bed 82.

In Fig. 61 Another device 80 for counter-rolling is illustrated. In this embodiment, the support 86 is disposed axially movable on the machine bed 82 and the headstock 84 is fixedly connected to the machine bed 82. On the support, in particular on a radial axis 87, 86, the forming rollers 40 are mounted radially movable.

Another possibility, not shown, is to provide behind the support 86 a tailstock or a holding device.

With the method according to the invention and the device according to the invention, tubular workpieces can be formed particularly economically and precisely overall.

Claims (16)

A stretch ironing method in which a tubular workpiece (10) is placed around a pusher mandrel (20), rotated and reformed by feeding at least one forming roll (40), reducing a wall thickness of the tubular workpiece (10), and the tubular workpiece (10) is lengthened,
characterized,
that the spinning mandrel (20) is moved relative to the workpiece (10) in the axial direction during the forming process. Method according to claim 1,
characterized,
that a universal spinning mandrel (20) is used with different in the axial direction outside diameters for producing differently shaped cylindrical and / or conical and / or cambered hollow parts. Method according to claim 1 or 2,
characterized,
that the method is carried out in the opposite direction, wherein material of the workpiece (10) against a feed direction of the forming roller (40) flows. Method according to claim 1 or 2,
characterized,
that the method is carried out in synchronism, wherein material of the workpiece (10) in the feed direction of the forming roller (40) flows. Method according to one of claims 1 to 4,
characterized,
that the forming roller (40) and the spinning mandrel (20) are moved relative to the workpiece (10) in the axial direction, the forming roller (40) being relatively axially and / or angularly adapted to form variable diameters and / or wall thicknesses of the workpiece (10) radial direction relative to the spinning mandrel (20) is moved. Method according to one of claims 1 to 5,
characterized,
in order to form a workpiece section with a constant diameter and a constant wall thickness, the forming roller (40) is moved at the same speed as the spinning mandrel (20) relative to the workpiece (10). Method according to one of claims 5 or 6,
characterized,
in that the relative movement of the forming roller (40) in the axial and / or radial direction relative to the spinning mandrel (20) is dependent on a relative position of the forming roller (40) relative to the spinning mandrel (20) and in dependence on a predetermined gap between the forming roller (40). and spinning mandrel (20) is controlled by means of a measuring and control device. Method according to one of claims 1 to 7,
characterized,
that the workpiece (10) is clamped to a chuck (94) which is rotatably supported and driven, and
that the spinning mandrel (20) is moved axially relative to the chuck (94). Apparatus for the ironing out of a tubular workpiece (10), in particular for carrying out the method according to one of claims 1 to 8, with
a spinning mandrel (20) which can be arranged in the tubular workpiece (10), at least one forming roller (40) for advancing and forming the workpiece (10) and a rotary drive for rotationally driving the workpiece (10),
characterized,
that the pusher mandrel (20) is mounted so as to be movable relative to the workpiece (10) in the axial direction during the forming process. Device according to claim 9,
characterized,
that the spinning mandrel (20) has different external diameters, in particular has a conical, cylindrical and / or cambered shape. Device according to claim 9 or 10,
characterized,
that the spinning mandrel (20) has at least one inner roller (39) on its outer circumference. Device according to one of claims 9 to 11,
characterized,
in that the rotary drive can be moved axially with a chuck (94) for clamping the workpiece (10) and / or a support (86) with at least two forming rollers (40) relative to a machine bed (82). Device according to claim 12,
characterized,
that the forming rollers (40) are arranged radially and / or axially movable on the support (86). Device according to one of claims 9 to 13,
characterized,
that the spinning mandrel (20) is axially movable relative to the chuck (94). Device according to claims 9 to 14,
characterized,
that a sensing and control means for measuring a length and / or a wall thickness and / or diameter of the workpiece (10) and for controlling radial movement of the forming rollers (40) and / or a relative axial movement of the forming rollers (40) against the Driven mandrel (20) is provided. Device according to one of claims 9 to 15,
characterized,
that a feed rod (34) is provided, which is connected to the spinning mandrel (20) and has a diameter which is smaller than the maximum diameter of the spinning mandrel (20), and
in that an axial drive (92) is provided for moving the feed rod (34).

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