Flow forming apparatus and flow forming method

Abstract

The invention relates to a flow forming apparatus and a method for flow forming a substantially rotationally symmetric workpiece having a drum-shaped periphery, the flow forming apparatus comprising: a spindle which can be driven in rotation about a spindle axis, a clamping device arranged on the spindle and having a number of clamping elements, the clamping elements being adjustable between a clamping position, in which the clamping elements abut against an outer peripheral region of the workpiece with a predefined clamping force and hold the workpiece on the spindle for forming, and a release position, in which the clamping elements are moved away from the workpiece in a defined manner by a first actuating device to release the workpiece from the spindle, the clamping device being able to apply a clamping force for holding the workpiece on the spindle during forming by the first actuating device, and a number of forming rollers which can be radially and axially fed to the drum-shaped periphery of the workpiece for forming the drum-shaped periphery. According to the invention, a second actuating device is provided in the clamping device, by means of which the position of the clamping element can be set in the radial direction to suit the diameter of the workpiece, and a control device is provided, by means of which the second actuating device can be actuated depending on the diameter of the workpiece to be formed, and the clamping element is pre-positioned in the radial direction depending on the diameter of the workpiece.

Description

[Technical field]

[0001] The invention relates to a flow forming apparatus for flow forming a substantially rotationally symmetrical workpiece having a drum-shaped periphery according to the preamble of claim 1, comprising a spindle which can be driven in rotation about a spindle axis, a clamping device arranged on the spindle and having a number of clamping elements, the clamping elements being adjustable between a clamping position, in which the clamping elements abut against the circumferential area of ​​the workpiece with a defined clamping force and hold the workpiece on the spindle for forming, and a release position, in which the clamping elements are moved away from the workpiece in a defined manner by a first actuating device to release the workpiece from the spindle, the clamping device being able to apply a clamping force by the first actuating device for holding the workpiece on the spindle during forming, and a number of forming rollers which are radially and axially feedable around the drum-shaped periphery of the workpiece for forming the drum-shaped periphery.

[0002] The invention further relates to a flow forming method according to the preamble of claim 18. [Background technology]

[0003] During flow forming of workpieces, in particular for the production of vehicle wheels, a drum-shaped wall region is formed by rotating a disk-shaped or pot-shaped workpiece and varying the wall thickness of the starting workpiece. During this operation, very large circumferential forces are generated in the workpiece in the axial and circumferential directions. In order to hold the workpiece securely on the spindle so that it is driven in rotation on the spindle, a clamping device must be provided on the driving spindle, which can exert a sufficiently large clamping force on the workpiece. The processing forces occurring in a flow forming apparatus can be many times larger than those that can occur, for example, on a lathe for machining materials.

[0004] In flow forming, to apply the clamping force required to hold the workpiece in the correct position on the spindle, it is known to press the workpiece axially against the spindle, usually by means of a counterholder, where a large axial clamping force can be applied by an axially acting hydraulic cylinder.

[0005] However, when the workpiece is axially clamped in the flow forming device by the counterholder, the internal space within the wall of the drum-shaped workpiece to be formed is completely or at least partially occupied, which means that the occupied internal space cannot be used as a processing space.

[0006] EP 3351313 A1 describes a flow forming apparatus of the general type, in which an internal space for feeding an inner forming roller is necessary for forming vehicle wheels. In general, a flow forming apparatus is described, in which a drum-shaped workpiece area is formed between at least one inner roller and at least one associated outer roller. For clamping the workpiece, a clamping device is provided having outer clamping claws, by which the workpiece is held on its radially outer edge during flow forming. The clamping claws have a linear displacement path and an actuating device, by means of which the clamping claws are adjustable between a release position and a clamping position for holding the workpiece. The actuating device adjusts the clamping claws and exerts the required clamping force on the workpiece to hold it on the spindle.

[0007] With this type of clamping device, the clamping travel needs to be set as small as possible to ensure efficient clamping with the desired high clamping force. Especially when the outer diameter of the workpiece changes, the clamping device needs to be readjusted with respect to the corresponding feed and clamping paths. Summary of the Invention [Problem to be solved by the invention]

[0008] The object underlying the present invention is to provide a flow-forming device and a method for flow-forming a workpiece, which allows a particularly efficient processing of the workpiece. [Means for solving the problem]

[0009] According to the invention, this object is achieved on the one hand by a device having the features of claim 1 and on the other hand by a method having the features of claim 18. Preferred embodiments of the invention are set out in the dependent claims. The invention in principle further comprises a method for flow forming a workpiece using such a flow forming device.

[0010] The flow forming apparatus according to the present invention is characterized in that a second actuating device is provided in the clamping device, by means of which the position of the clamping element can be set radially to suit the diameter of the workpiece, and a control device is provided, by means of which the second actuating device can be actuated depending on the diameter of the workpiece to be formed, and the clamping element is pre-positioned radially depending on the diameter of the workpiece.

[0011] The basic idea of ​​the invention is to provide a flow forming apparatus with a clamping device, which has a first actuating device for adjusting the clamping elements, which always ensures an identical or substantially identical adjustment path of the clamping elements, such that after the intended adjustment path of the clamping elements a desired clamping force is realized by the first actuating device. In addition, the clamping device of the flow forming apparatus according to the invention has a second actuating device, by means of which a prepositioning of the clamping elements in the radial direction can be set to match the diameter of the workpiece. This prepositioning is automatically controlled by a control device, which actuates the second actuating device based on information about the workpiece to be processed, in particular the diameter of the workpiece to be formed, thus preparing a suitable prepositioning of the clamping elements for the actual clamping movement by the first actuating device.

[0012] The invention not only ensures particularly good clamping on the outside of the workpiece, but also ensures that the flow forming of the workpiece can be performed with high forming forces. Prepositioning also reduces the time required for the actual clamping of the workpiece, thus reducing the proportion of non-productive times during the processing of the workpiece. This improves the utilization of the equipment and reduces costs.

[0013] In addition, an advantage of the present invention is that high processing flexibility can be achieved due to the automatic prepositioning of the clamping elements by the second actuating device via the control device. Thus, a large number of workpieces with different diameters can be efficiently flow formed in almost any sequence without time-consuming modifications to the clamping device. It is preferable to only activate the second actuating device when there is a change in the type of workpiece, i.e. when processing workpieces with different starting dimensions and diameters.

[0014] A preferred embodiment of the invention is that the clamping elements are axially and / or radially adjustable between a clamped position and a released position by the first actuating device. In particular, the clamping elements are first radially and then axially fed by the first actuating device, and the actual clamping force is caused only or to a large extent by the axial movement of the clamping elements. This allows the workpiece to be pressed against the spindle and held on it with particular reliability.

[0015] In principle, the actuating device can be configured in any way, for example by means of a recirculating ball screw. According to a further development of the invention, particularly large actuating forces can be realized in that the first actuating device has at least one actuating cylinder, which is preferably hydraulically operated. The actuating cylinder can generate the required clamping force by itself or in combination with at least one further force-generating element, such as a disk spring assembly.

[0016] The overall clamping force can be further increased in that each clamping element is assigned an actuating cylinder by means of which the adjustment elements can be displaced between a clamped position and a released position, in which the clamping elements are each spaced to a certain extent from the workpiece so that the workpiece can be removed from the spindle and a new workpiece can be inserted.

[0017] In principle, individual clamping elements may be provided on displaceable carriages for prepositioning. According to a further development of the invention, it is particularly suitable for each clamping element to be mounted on a rotatable disk eccentrically with respect to the disk axis, the disk axis being oriented parallel to the spindle axis, and the second actuating device comprises an actuator for rotating the disk together with the clamping element. In principle, an actuator for rotating can be assigned to each rotatable disk. It is particularly advantageous for a single actuator, in particular an adjusting wheel, to be provided for rotating all disks. The adjusting wheel can be controlled and actuated via a corresponding drive pinion of the second actuating device. In principle, the flow forming apparatus may be provided with a horizontally oriented spindle axis.

[0018] Alternatively, according to an embodiment of the invention, it is preferred here that the clamping elements are mounted on a radially displaceable or pivotable carriage and the second actuating device is configured to radially displace or pivot the carriage. An actuating cylinder for displacing and clamping the respective clamping element may be arranged on the carriage.

[0019] According to a further development of the invention, a particularly compact design is achieved in that the spindle axis is arranged vertically and the clamping device is arranged suspended relative to the spindle, so that the workpiece can be clamped from below. Such a vertical suspension of the workpiece makes it particularly easy to remove the workpiece by automatic loading and unloading devices, in particular manipulator arms and / or robots. When the clamping device is released, the workpiece can be removed downwards in a simple manner, preferably by the same manipulator and / or robot.

[0020] According to a further preferred embodiment of the invention, at least one outlet is provided and a suction device is provided, by means of which air and / or smoke can be advantageously sucked through the at least one outlet. The outlet can preferably be provided in the area of ​​the clamping device, in particular in the case of a hanging arrangement. Via one or more outlets, steam, in particular containing oil or coolant components, can be efficiently removed from the working chamber and fed to a separation device and / or a recycling device for recovery of the cooling and lubricating fluid.

[0021] According to an embodiment of the present invention, the processing is further improved in that a central centering pin, preferably configured for elastic and / or compliant centering, is arranged in the clamping device for reliable and accurate centering of workpieces with different inner diameters, thereby allowing a reliable and gentle centering of the workpiece on the spindle before or during clamping.

[0022] According to a variant of an embodiment of the present invention, a particularly efficient processing flow is realized in that a control device for supplying data on the workpiece, in particular data on the diameter of the workpiece, is connected to the control station and / or to at least one sensor for detecting the workpiece using the diameter. Via the central control station, the flow forming device can be constantly supplied with information on the type of workpiece currently to be processed. In the case of chaotic production with a large number of possible pre-processing stations, the type of workpiece, in particular the diameter, can be detected by at least one sensor connected to the control device. Depending on the supplied data, if necessary, a second actuation device for pre-positioning the clamping element can be actuated via the control device.

[0023] Furthermore, for flexible forming of each individual workpiece, it is advantageous for the control device to control the movement of the forming roller during forming. Depending on the type of workpiece to be processed, the forming roller can thus be displaced in a defined manner by the control device to form the desired wall thickness profile and the desired workpiece contour. With the flow forming device according to the invention, a flexible and efficient production of even fewer or even more individual workpieces can thus be realized.

[0024] In particular, a further development of the flow forming device according to the invention provides a particularly high degree of flexibility in that at least one outer forming roller and at least one inner forming roller are provided, which rest against the outer and inner circumferences, respectively, of the drum-shaped periphery of the workpiece and are axially and radially adjustable relative to one another by a control device in order to form and produce wall thickness profiles with varying wall thicknesses, and / or the pitch angle of at least one inner forming roller is variable. In this way, individual contours and wall thickness profiles can be produced for almost any individual workpiece with the same efficiency as in mass production.

[0025] Another preferred embodiment of the invention is that two exchangeable spindles are provided, a first one being located in the working chamber while a second one is located in a loading and / or unloading position, the two exchangeable spindles being alternately movable relative to each other. The two exchangeable spindles may be reversibly displaceable, the two exchangeable spindles alternate between a working position in the working chamber and one of two loading and / or unloading positions for loading or unloading the workpiece. For example, a turret mechanism may be provided. The individual exchangeable spindles may also have different loading and unloading positions from each other, from which each exchangeable spindle is subsequently displaced into the respective working chamber. This allows for quick loading and / or unloading, and therefore faster overall processing times.

[0026] According to a further development of the invention, it is advantageous if a measuring device is arranged by means of which dimensions and data related to the processing of the workpiece can be determined before and / or after forming. The measuring device can in particular comprise an optical sensor and / or a thermal sensor for determining the workpiece. The measuring device in particular communicates with the control device.

[0027] As a rule, flow forming apparatuses are designed for cold forming methods. For certain processes it may be advantageous to provide at least one cooling device and / or one thermal protection device for semi-hot and / or hot forming of the workpiece. In particular for the forming of light metal wheels, a targeted temperature control of the workpiece can be realized and regulated in this way. In hot forming, the temperature of the workpiece blank can also be measured by a pyrometer or temperature sensor before the workpiece blank is introduced into the working area of ​​the flow forming apparatus.

[0028] The rollers of the inner and outer supports are preferably configured as standard universal rollers of the flow forming apparatus. However, certain wheel or wheel hub shapes may require a change of the rollers. A further improvement in terms of the flexibility of the flow forming apparatus according to the invention can be realized in that a quick release clamping device is arranged on the inner and / or outer supports at at least one bearing of the outer forming roller and / or at least one inner forming roller, which allows a semi-automatic or fully automatic roller change. The shape of the rollers can be efficiently adapted to the corresponding contour path of a particular workpiece. This further increases the variety of workpiece shapes that can be realized by the flow forming apparatus.

[0029] For targeted temperature control during forming, it may also be useful for the workpiece to have a different temperature in the forming area than in the clamping and / or centering areas. The areas of the spokes preferably have a lower temperature than the forming area. In particular, a higher temperature may be provided in the forming area or working area of ​​the workpiece, where the forming rollers engage.

[0030] The invention relates in particular to a method for flow forming a substantially rotationally symmetrical workpiece having a drum-shaped periphery, in particular by means of one of the flow forming apparatuses mentioned above, in which the workpiece is clamped to a spindle by a clamping device, the clamping device having a plurality of clamping elements, the clamping elements being adjusted between a clamping position, in which the clamping elements bear with a predefined clamping force against the circumferential area of ​​the workpiece and hold the workpiece on the spindle for forming, and a release position, in which the clamping elements are moved away from the workpiece in a defined manner by a first actuating device in order to release the workpiece from the spindle, for holding the workpiece on the spindle during forming. a clamping force of 0.01 mm is applied by a first actuating device, the spindle is driven in rotation about the spindle axis and a number of forming rollers are fed radially and axially onto the workpiece for forming the drum-shaped peripheral portion, in particular a second actuating device is provided on the clamping device by means of which the position of the clamping elements is adapted to the diameter of the workpiece and the clamping elements are adjusted radially, and a control device is provided by means of which the second actuating device is actuated depending on the diameter of the workpiece to be formed and the clamping elements are pre-positioned radially depending on the diameter of the workpiece.

[0031] A particularly energy-efficient flow forming apparatus has the option of recovery when braking at least one main spindle with a chuck. Despite the lightweight design of the chuck, a significant mass needs to be accelerated or decelerated. It is preferable to use the recovered energy of the first exchangeable spindle to accelerate the energy stores of the mass of the second exchangeable spindle and / or the flywheel. Alternatively, energy recovery with net regenerative feedback is also possible.

[0032] To specifically increase the availability of the flow forming apparatus, an apparatus having two interchangeable spindles can also be economically operated as a single spindle apparatus. In the event of low capacity utilization, raw material shortages, maintenance or failure of the interchangeable spindle, and / or failure of an upstream and / or downstream line or system, the flow forming apparatus can continue to operate with only one spindle.

[0033] The invention will be explained in more detail below with reference to preferred exemplary embodiments which are illustrated diagrammatically in the drawings. [Brief description of the drawings]

[0034] [Figure 1] FIG. 2 is a perspective view of a flow forming apparatus according to the present invention, without the protective housing and the loading and unloading device. [Diagram 2] FIG. 2 is an enlarged view of a clamping device of a flow forming apparatus according to the present invention, showing a clamped workpiece in cross section. [Diagram 3] FIG. 3 is an enlarged, partially cut-away, detailed perspective view of the clamping device according to FIG. 2; [Figure 4] FIG. 4 is another enlarged, partially cutaway, detailed perspective view of the adjustment mechanism of the clamping device according to FIGS. 2 and 3; [Diagram 5] FIG. 11 is a cross-sectional view of an alternative clamping device of a flow forming apparatus according to the present invention. [Figure 6] FIG. 5 is a top view of the clamping device. [Figure 7] FIG. 7 is a perspective view of the clamping device according to FIGS. 5 and 6 . [Figure 8] FIG. 8 is another cross-sectional view of the clamping device according to FIGS. 5 to 7, in which the clamping element is shown in the right half in the released position. [Figure 9] FIG. 9 is another cross-sectional view of the clamping device according to FIGS. 5 to 8, in which an intermediate position during clamping is shown in the right half. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] The flow forming apparatus 10 according to the invention and according to Fig. 1 has a base frame 12 including three vertical columns 14 surrounding a working chamber. Two rotary drive spindles 20 are mounted on the plate-like cover area 16 and are alternately movable and linearly slidable between an outer loading and unloading position and a central working position by means of a linear drive 22.

[0036] A clamping device 40 for lifting and holding the workpiece 5 in a suspended position is provided on the underside of each spindle 20 facing downwards towards the working chamber. Claw-like clamping elements 50 distributed along the periphery are arranged on the drum-like clamping device 40 for clamping the workpiece 5, as will be explained in more detail below.

[0037] Each of the vertical columns 14 is provided with a radially and vertically adjustable forming roller 30, which in principle may also be angled, the outer forming roller 30a being rotatably mounted respectively on an outer support 34 and the inner forming roller 30b being rotatably mounted respectively on an inner support 38. As clearly shown in FIG. 2, the inner roller 30b is configured to run within the interior space of the workpiece 5, the outer roller 30a being configured to machine the outer circumference of the workpiece 5. The outer roller 30a and the inner roller 30b are displaceable in the axial and radial directions.

[0038] According to Fig. 2, a drum-shaped workpiece 5, in particular a cast or forged blank of a vehicle wheel, is clamped to and suspended from a clamping device 40. The workpiece 5 has a hub 6 with a central hole, into which a centering pin 44 of the clamping device 40 engages for centering purposes. For pressure-fit and form-fit retention, several claw-like clamping elements 50 are fed to the radially outer upper edge of the workpiece 5, which is pressed axially against the clamping device 40.

[0039] The outer forming roller 30a and the inner forming roller 30b are fed in pairs relative to each other to the drum-shaped periphery 7 of the workpiece 5 and can be displaced radially and / or axially relative to each other to set a forming gap so as to flow form the drum-shaped periphery 7 and form individual wall thickness profiles with varying wall thicknesses, in particular thick humps and rim flanges for receiving vehicle tyres in the drum-shaped periphery 7.

[0040] In the following, the structure of the clamping device 40 of the flow forming apparatus 10 according to the invention will be explained in more detail in conjunction with Figures 3 and 4. The drum-like clamping device 40 has a substantially pot-shaped housing 42 in which a first actuating device 60 is provided for axially adjusting the claw-like clamping element 50 in a vertical clamping direction. To move the clamping element 50 between a lower release position and an upper clamping position, the clamping element 50 is arranged on a lifting shaft 52 connected to an actuating cylinder 62 and / or a lifting plate 64.

[0041] In the clamping position, the workpiece 5 is pressed upwards by the clamping elements 50 against the corresponding counterholders 54, which are attached with the respective clamping elements 50 to a plate-shaped disk 74 of the second actuation device 70. The disk 74 has an external toothing which is connected via an intermediate gear 76 to a central actuator 78 configured as an external toothed gear. A rotational movement of the central actuator 78 transfers the rotational movement to the respective disk 74 via the intermediate gear 76. The clamping elements 50 with their lifting axis 52 are attached to the disk 74 eccentrically with respect to the disk axis 72. The rotational movement thus changes the radial distance between the clamping elements 50 and the central axis of rotation, such that a radial prepositioning of the clamping elements 50 to adapt to a change in the diameter of the workpiece 5 can be easily performed by adjusting the central actuator 78.

[0042] Along the periphery of the central actuator 78, a number of disks 74 each having a clamping element 50 and a counter holder 54 are arranged to clamp the workpiece 5 uniformly along the periphery.

[0043] For axial clamping, the clamping force is generated by the respective actuating cylinders 62 of the clamping elements 50 and / or the lifting plates 64, which can be activated by an axial lifting mechanism (not shown) for uniform actuation of all clamping elements 50. A spring device 68 at the upper end of the lifting shaft 52 can be used to preload and compensate for thickness differences. In principle, an additional axial clamping force for clamping the workpiece 5 can also be applied via the spring clamping device 68.

[0044] For the concentric movement of the clamping elements 50 and the counterholder 54 a radial groove-like guide is provided in the guide disc 65 of each clamping element 50 .

[0045] For adjustment of the central diameter, a central adjustment element with position detection is provided above the drive spindle 20, which is connected via a drive shaft to a multi-spline coupling 79 and can counteract the corresponding adjustment forces of the clamping element 50 and the centrifugal forces.

[0046] An alternative clamping device 40 of a flow forming apparatus 10 according to the invention is shown in figures 5 to 9. According to figure 5, the clamping device 40 has a drum-shaped base body, on whose end faces a number of clamping elements 50, in particular eight clamping elements 50, are arranged distributed along the circumference of the workpiece 5 for clamping the same. Each clamping element 50 is adjustable together with the associated actuating cylinder 62 on a plate-shaped carriage 73 parallel to the central axis of rotation. The carriage 73 is mounted for radial displacement along a radially directed guide groove of the drum-shaped base body. A central centering pin 44 is provided for centering the workpiece 5 and can enter axially into a corresponding central opening of the workpiece 5.

[0047] To clamp the workpiece 5, the clamping element 50 is first in a release position, which is shown diagrammatically in the right half of Fig. 8. In this release position, the carriage 73 of the second actuating device is displaced radially outwards. At the same time, the clamping element 50 is displaced axially upwards by the actuating cylinder 62, as shown in Fig. 8.

[0048] When all clamping elements 50 are in this released position, the workpiece 5 can be positioned and centred concentrically with respect to the axis of rotation by means of the centreing pin 44 .

[0049] The carriage 73 is displaced radially inwards, preferably by an actuating cylinder (not shown), more particularly via a second actuating device (not shown), until the clamping elements 50 radially contact the workpiece 5. This is clearly shown in the right half of FIG.

[0050] Starting from this prepositioning by the second actuating device with the carriage 73, the workpiece 5 can be firmly clamped by the clamping element 50, the state which is clearly shown in Figs. 5 to 7 being achieved. For this, the clamping element 50 is displaced downwards via the actuating cylinder 62, whereby the workpiece 5 is pressed against the base body of the clamping device 40 and firmly clamped. To release the workpiece 5, the clamping element 50 can be displaced in the reverse order to the initial or release position according to Fig. 8.

[0051] Also in this variant of the invention, the prepositioning of the clamping element 50 can be effected by means of a second actuating device, preferably by means of a radially linearly displaceable carriage 73. This allows the clamping device to efficiently clamp on workpieces 5 having different outer diameters.

[0052] In principle, the clamping or centering pin 44 may alternatively be configured as a jaw chuck, such that the jaw chuck can clamp onto an internal bore and / or clamp externally onto a sprue pin of the casting blank.

[0053] In principle, the clamping element 50 may alternatively be fed axially relative to the workpiece 5 for clamping by a pivoting movement.

Claims

1. 1. A flow forming apparatus for flow forming a substantially rotationally symmetric workpiece having a drum-shaped periphery, comprising: a spindle which can be driven in rotation about a spindle axis; a clamping device arranged on the spindle and having a plurality of clamping elements, the clamping elements being adjustable between a clamping position in which the clamping elements bear against a peripheral region of the workpiece with a predefined clamping force and hold the workpiece on the spindle for forming, and a release position in which the clamping elements are moved away from the workpiece in a defined manner by a first actuating device to release the workpiece from the spindle, the clamping force for holding the workpiece on the spindle during forming being able to be applied by the first actuating device; a plurality of forming rollers which are radially and axially feedable around the drum-shaped periphery of the workpiece for forming the drum-shaped periphery of the workpiece, a second actuation device is provided on said clamping device, by means of which the position of said clamping element can be set in said radial direction to suit the diameter of said workpiece, a control device is provided by which the second actuation device can be actuated as a function of the diameter of the workpiece to be formed, and the clamping elements are prepositioned in the radial direction as a function of the diameter of the workpiece.

2. 2. The flow forming apparatus of claim 1, wherein the clamping element is adjustable in the axial and / or radial direction between the clamped position and the released position by the first actuation device.

3. 2. A flow forming apparatus according to claim 1, characterized in that the first actuating device comprises at least one actuating cylinder, preferably hydraulically operated.

4. 4. A flow forming device according to claim 3, characterized in that each clamping element is assigned an actuating cylinder by means of which said clamping elements can each be displaced between said clamping position and said release position.

5. Each clamping element is mounted on a rotatable disk eccentrically with respect to a disk axis, the disk axis being oriented parallel to the spindle axis; The flow forming apparatus of claim 1 , wherein the second actuation device comprises an actuator for rotating the disk together with the clamping element.

6. Each clamping element is mounted on the radially displaceable or pivotable carriage, The flow forming apparatus of claim 1 , wherein the second actuation device is configured to displace or pivot the carriage in the radial direction.

7. The spindle axis is disposed vertically; the clamping device is disposed suspended from the spindle; 2. The flow forming apparatus according to claim 1, wherein the workpiece can be clamped from below.

8. At least one exhaust port is provided; and 2. The flow forming apparatus according to claim 1, characterized in that a suction device is provided, by means of which air and / or smoke can be sucked through said at least one outlet.

9. 2. The flow forming apparatus according to claim 1, characterized in that a central centering pin (12) configured to be elastic and / or flexible is arranged in the clamping device.

10. 2. A flow forming apparatus according to claim 1, characterized in that the control device for supplying data relating to the workpiece, in particular data relating to the diameter of the workpiece, is connected to a control station and / or to at least one sensor for identifying the workpiece using the diameter of the workpiece.

11. 2. A flow forming apparatus according to claim 1, characterized in that the control device controls the movement of the forming rollers during forming for soft forming of each individual workpiece.

12. 2. The flow forming apparatus according to claim 1, characterized in that at least one outer forming roller and at least one inner forming roller are provided, the at least one outer forming roller and the at least one inner forming roller abutting the outer and inner circumferences of the drum-shaped periphery of the workpiece and being adjustable in the axial and radial directions relative to one another by the control device in order to form and create a wall thickness profile with a varying wall thickness and / or the pitch angle of the at least one inner forming roller is variable.

13. 2. The flow forming apparatus according to claim 1, characterized in that two exchangeable spindles are provided, a first exchangeable spindle being located in the working chamber while a second exchangeable spindle is located in a loading position and / or an unloading position, said two exchangeable spindles being alternately displaceable relative to each other.

14. 2. A flow forming apparatus according to claim 1, characterized in that a measuring device is arranged, by means of which dimensions and data related to the processing of the workpiece can be determined before and / or after forming.

15. 2. A flow forming apparatus according to claim 1, characterized in that at least one cooling device and / or one thermal protection device is provided for semi-hot forming and / or hot forming of the workpiece.

16. 2. The flow forming apparatus according to claim 1, characterized in that quick-release clamping devices are arranged on the inner and / or outer supports at the bearings of at least one outer forming roller and / or at least one inner forming roller, said quick-release clamping devices allowing semi-automatic or fully automatic roller changing.

17. 10. The flow forming apparatus of claim 1, wherein the workpiece has a different temperature in the forming region than in the clamping and centering regions.

18. A method for flow forming a substantially rotationally symmetrical workpiece having a drum-shaped periphery, in particular by using a flow forming device as claimed in claim 1, comprising the steps of: the workpiece is clamped to the spindle by a clamping device, the clamping device having a plurality of clamping elements, the clamping elements being adjustable between a clamping position in which the clamping elements bear against a peripheral region of the workpiece with a predefined clamping force and hold the workpiece on the spindle for forming, and a release position in which the clamping elements are moved away from the workpiece in a defined manner to release the workpiece from the spindle, the clamping force for holding the workpiece on the spindle during forming being applied by a first actuation device, - said spindle is driven in rotation about its spindle axis, - for forming the drum-like periphery, a number of forming rollers are fed radially and axially onto the workpiece, a second actuation device is provided on the clamping device, by means of which the position of the clamping elements is adapted to the diameter of the workpiece and the clamping elements are set in the radial direction, a control device is provided, by means of which the second actuation device is actuated as a function of the diameter of the workpiece to be formed, and the clamping element is prepositioned in the radial direction as a function of the diameter of the workpiece.

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