Forming machine for pressing and flow forming

Abstract

The invention relates to a forming machine for pressing and flow forming, comprising: a vertically directed main spindle, on which a forming tool is disposed; a first drive, by means of which the main spindle can be driven to rotate about a vertically directed axis of rotation; a tailstock spindle, which is coaxial with the main spindle and can be axially moved relative to the main spindle; a machine lower bed and a machine upper bed, which are interconnected by at least three vertically directed machine stands, the main spindle being disposed on the machine lower bed and the at least three machine stands being distributed around the axis of rotation, said machine stands surrounding a working space; and at least one forming roller, which is guided such that the forming roller can be axially moved along at least one machine stand and such that the forming roller can be radially advanced. According to the invention, the tailstock spindle is disposed on a carriage, which is axially guided and supported on the at least three machine stands, by means of at least one linear guide in each case, such that the carriage stiffens the machine stands to prevent them being forced open outward in the radial direction.

Description

[0001] Forming machine for pressing and flow-forming

[0002] The invention relates to a forming machine for spinning and flow-forming, comprising a vertically directed main spindle on which a forming tool is arranged, a first drive with which the main spindle can be driven to rotate about a vertically directed axis of rotation, a tailstock spindle which is arranged coaxially to the main spindle and can be moved relative thereto, a machine base and a machine top bed which are connected to one another via at least three vertically directed machine stands, wherein the main spindle is arranged on the machine base and the at least three machine stands are arranged distributed around the axis of rotation which define a work space, and at least one forming roller which is guided so as to be axially movable and radially adjustable along at least one machine stand, according to the preamble of claim 1.

[0003] Forming machines with a vertically oriented rotary axis have been known for a long time. DE 9103358 U1 describes a forming machine with two vertically oriented machine columns. Drives are located on both the lower and upper machine columns to drive the main spindle and tailstock spindle separately. When using two machine columns, the rigidity of the machine frame is limited.

[0004] Increased rigidity of the machine frame is achieved by the arrangement of three machine columns, as is known, for example, from the generic document DE102007012765 B4. In this known forming machine, the tailstock spindle is guided linearly along the three machine columns. High machine rigidity is important to ensure precise guidance and positioning of the forming rollers and thus achieve high forming accuracy.

[0005] The invention is based on the object of specifying a forming machine which has a particularly high machine rigidity.

[0006] According to the invention, the object is achieved by a forming machine having the features of claim 1. Preferred embodiments of the invention are specified in the dependent claims.

[0007] The forming machine according to the invention is characterized in that the tailstock spindle is arranged on a carriage which is axially guided and mounted on the at least three machine stands, each with at least one linear guide, in such a way that the carriage stiffens the machine stands against bending outwards in the radial direction.

[0008] The invention is based on the discovery that during the pressing or flow-forming of a workpiece, considerable radially directed forming forces are exerted by the forming rollers onto the centrally mounted workpiece. These processing forces must be absorbed by the machine stands, on which the individual forming rollers are movably mounted and guided. The machine stands act as abutments, so to speak, and are subjected to radially outward-directed forces during a forming process, which can bend the vertical or column-like machine stands radially outward. Even with a very rigid machine stand design, undesirable bending can occur with large forming forces in the range of tenths of a millimeter or millimeters, which can have a negative impact on the forming accuracy.

[0009] According to one aspect of the invention, this is counteracted by a carriage for the tailstock spindle being designed and arranged in such a way that the carriage is guided along the machine stands in such a way that it stiffens the machine stands against bending in the radial outward direction. The carriage thus serves as a transverse stiffener which is guided so as to be movable vertically along the machine stands. Radially outwardly directed forces on the machine stands, which are preferably distributed symmetrically around the axis of rotation, can thus be absorbed by the carriage, which is directed in particular horizontally, and can be compensated against one another. The resulting increased rigidity of the machine against radially outward forces leads to an increase in dimensional accuracy during forming.

[0010] According to a further development of the invention, it is particularly preferred that the at least one linear guide per machine stand is designed to engage behind or form-fit in a radial direction in the direction of the radially introduced forces. In particular, there is a guide surface directed radially outwards with respect to the axis of rotation and a guide surface directed radially inwards between the respective machine stand and the carriage, so that radially outwards directed forces can be transmitted from the respective machine stand to the carriage. The carriage is designed to be correspondingly rigid so that it can absorb the radial forces from the individual stands and largely cancel them out against each other.

[0011] A particularly advantageous embodiment of the invention consists in that at least one linear guide rail is formed on each machine stand, which has a radially outward-facing guide surface, and in that each guide rail is assigned at least one guide element, which is mounted on the carriage and bears against the radially outward-facing guide surface of the associated guide rail to guide the carriage. The at least one guide element on the carriage can be a guide roller, a guide ball, and / or a sliding or rolling guide shoe, which bears against the outward-facing guide rail of the machine stand. This allows for particularly good stiffening.

[0012] In principle, only the main spindle of a forming machine can be driven in rotation. A particularly advantageous embodiment of the forming machine according to the invention results from the fact that a second drive, ideally of the same size, is arranged on the carriage, with which the tailstock spindle can be driven in rotation about the rotational axis and / or synchronously in speed and / or angle. Particularly high torques can be applied via two drives when forming a workpiece that must be driven in rotation for forming.

[0013] A further advantageous embodiment of the invention is based on the fact that a roller support for at least one forming roller is slidably guided along at least one machine stand, and that the roller support is provided with an axial feed drive and a radial feed drive for the forming roller. This results in an overall compact design, with each machine stand carrying and guiding not only the carriage but also a roller support. Ideally, the carriage and the at least one roller support are guided over the same rails. The individual roller supports can be individually controlled and adjusted via their own axial feed drive. This allows the forming of workpieces with a wide variety of shapes.

[0014] A particularly compact arrangement of the forming machine is achieved according to one embodiment of the invention in that each machine stand has two box-shaped columns, between which a free space is formed, and in that at least one roller support for the forming roller is movably guided in the free space. The carriage can have a fork-shaped holder, at the ends of which a guide element is arranged for guiding on a guide rail on each of the box-shaped columns. The fork-shaped holder can encompass the individual machine stand with the two box-shaped columns and thus provide the desired stiffening guidance on the outside of the two box-shaped columns.

[0015] In principle, only a single roller support or a portion of the roller supports can be mounted on a machine stand. According to a further development of the invention, it is particularly expedient for a roller support to be mounted on each machine stand.

[0016] Furthermore, according to one embodiment of the invention, it is preferred that at least one forming roller is arranged at an angle of 5 degrees to 20 degrees to the axis of rotation. This allows a further improvement in the rolling behavior of the forming roller on the workpiece during the forming of round blanks due to the resulting clearance angle at the roller outlet. By arranging the forming roller at an angle of 5 to 20 degrees, a significant reduction in the radial roller engagement surface can be achieved, so that different circumferential speeds between the workpiece and the forming roller are reduced to a minimum. This also sustainably minimizes wear on the forming roller and improves dimensional accuracy during forming on cylindrical and especially conical tool geometries. The forming rollers on the individual roller supports can be mounted for passive rotation.Upon contact with the rotating workpiece, the forming rollers can be passively set in rotation. To avoid slippage on the forming rollers and thus achieve particularly high dimensional accuracy, according to a further embodiment of the invention, a forming roller drive is provided for at least one forming roller, with which the forming roller can be driven at a predetermined speed. Synchronization between the rotational speed of the workpiece or the peripheral speed at the diameter of the forming roller engagement and the rotational speed of the forming roller can be set and ensured via a generally known control unit.

[0017] A further preferred embodiment of the invention consists in that at least one processing unit with a forming roller is arranged in a passage area between two machine stands. This provides a relatively large amount of free space for arranging and advancing the at least one forming roller. Several forming rollers can also be provided on a roller support with a corresponding changing device for changing the forming roller, which is located in an operating position for forming. Furthermore, the roller support can be equipped with an angle adjustment device for the forming roller, so that the working angle and / or forming roller geometry can be optimally adjusted for the processing task. Angle adjustment can be carried out manually or automatically.

[0018] A further particularly expedient embodiment of the forming machine according to the invention is achieved in that a connecting device for connecting and lifting the forming tool from the main spindle is arranged on the axially movable carriage. The forming tool is mounted on the main spindle in a detachable and replaceable manner. The forming tool can be connected to the carriage via a connecting device on the axially movable carriage arranged above it. A chain, one or more connecting rods, or one or more other connecting elements can be used for the connection. By axially moving the carriage upwards, it can serve as a lifting device to separate the forming tool from the main spindle. This facilitates the process of changing the forming tool. Changing the forming tool may be necessary in particular if a different workpiece contour is intended for machining.

[0019] A further improvement in the changing process can be achieved according to one embodiment of the invention by arranging a tool changing device on the machine base, which is designed to feed and / or remove the forming tool to or from the main spindle. The tool device can, in particular, be designed as a transverse displacement device for radially displacing the released forming tool from the main spindle or a new forming tool to the main spindle.

[0020] A further preferred embodiment of the forming machine according to the invention can be achieved in that an axially movable unit which can be pivoted radially into the center and which has a connecting device for connecting and lifting the forming tool from the main spindle is arranged on the machine stand.

[0021] A further increase in the forming flexibility of the machine according to the invention can be achieved by equipping the tailstock spindle with a clamping extension with a clamping disk. This allows the necessary clamping contact to be achieved when machining certain workpieces, even with a limited travel of the tailstock spindle along the machine columns.

[0022] The forming machine according to the invention can be used particularly flexibly. In particular, according to one embodiment of the invention, the machine is designed for forming steel wheel wrenches and / or steel wheels. In particular, steel wheels for larger vehicles, such as trucks or buses, can be produced. This requires relatively large, bulky, and / or high-strength starting workpieces, which are usually a sheet metal blank or a semi-finished product preformed by casting, pressing, or forging. A further improvement in forming accuracy can be achieved according to a development of the invention by designing the tailstock spindle with a measuring device as a positioning axis. In this way, the travel path of the tailstock spindle and thus of the carriage along the machine column can also be precisely determined.The position measurement data can be fed to a control unit for controlling and moving the tailstock spindle.

[0023] A further advantageous embodiment of the invention is that the contact pressure of the tailstock spindle is adjustable and / or programmable. The tailstock spindle can be equipped with a corresponding feed drive. This can comprise a ball screw or, in particular, one or more hydraulic cylinders.

[0024] A further increase in machining flexibility is achieved according to a further development of the invention by providing the tailstock spindle with a first axially displaceable clamping extension with a clamping ring, which preferably extends beyond a second clamping extension with a clamping disk. By using an outer first clamping extension and a second inner clamping extension, a particularly targeted pressing of the workpiece against the forming tool on the main spindle can be achieved. Only the inner clamping extension can also be provided.

[0025] For efficient release of the formed workpiece, it is advantageous to have an ejector unit and / or stripper unit arranged on the main spindle and / or the tailstock spindle. This can, in particular, comprise a hydraulically actuated and axially adjustable cylinder with an ejector and / or stripper element. The ejector and / or stripper element on the main spindle side can advantageously be used additionally to lift the finished workpiece from the tool to a removal level and / or lower the blank to a clamping and machining level.

[0026] In principle, only a single forming tool can be arranged on the main spindle. The forming tool defines the internal contour of the workpiece to be formed. Particularly for the production of vehicle wheels, in which a rim base extends on both sides of a radial hub area, an advantageous embodiment of the forming machine is that the tailstock spindle is designed to accommodate an additional forming tool.

[0027] The forming rolls can generally only be arranged on the designated roller supports. According to a further development of the invention, forming flexibility is further increased by designing the carriage to accommodate forming rolls. Thus, not only the tailstock spindle but also one or more forming rolls are mounted on the carriage, which can be moved axially along the machine columns. These can be advanced radially and / or axially to the workpiece via appropriate drives in order to form it.

[0028] According to a further development of the invention, it is preferred that the machine stands be connected to each other in their central regions via cross braces. This provides additional stiffening against radially outward deflection.

[0029] The invention will be further explained with reference to preferred embodiments, which are schematically illustrated in the figures. In the figures:

[0030] Fig. 1: a plan view of an embodiment of a forming machine according to the invention;

[0031] Fig. 2: a cross-sectional view of the machine of Fig. 1 according to section CC;

[0032] Fig. 3: a perspective view of the machine according to Fig. 1 , with components omitted;

[0033] Fig. 4: a schematic cross-sectional view through a spindle area of ​​the forming machine according to the invention;

[0034] Fig. 5: a perspective view of the machine frame;

[0035] Fig. 6: a side view of the forming machine according to the invention; and

[0036] Fig. 7: a cross-sectional view of the machine of Fig. 6 according to the section

[0037] AA. The basic structure of a forming machine 10 according to the invention is explained using the exemplary embodiment shown in Figures 1 to 4. The top view shown in Figure 1 shows a star-shaped machine frame 24 with three machine stands 30. Between the three vertical machine stands 30, a first passage area 34a, a second passage area 34b, and a third passage area 34c are formed, through which an inner working space 5 is accessed.

[0038] At the first passage area 34a, a removal device 60 with a conveyor belt serving as a conveyor device 64 is arranged. By means of a gripper (not shown), a workpiece can be brought from the stripping device (not shown) onto the conveyor device 64 out of work space 5.

[0039] A feed device 70 with a gripper 72 is arranged at the second passage area 34b. The gripper 72 can separate and pick up a blank from a conveying or supply device (not shown), then feed it to the work area 5 and place it on a forming tool (not shown).

[0040] An additional processing unit 40 can be arranged at the third passage area 34c, which will be explained in more detail below.

[0041] According to Fig. 2, the machine frame 24 has a machine base 26 and a plate-shaped machine top bed 28, which are firmly connected to one another via the three vertical machine stands 30.

[0042] A main spindle 12 with a forming tool 14 for holding a workpiece 1 is arranged on the machine base 26. The main spindle 12 with the forming tool 14 is driven to rotate about a rotational axis 18 via a first drive 16. An ejector unit 80 is provided below the main spindle 12. The ejector unit 80 is used for loading—transferring the workpiece 1 from the feed device 70 for positioning and clamping the workpiece 1 on the rotational axis 18, with subsequent clamping onto the forming tool 14—and for unloading, breaking off, and pushing the workpieces 1 off the forming tool 14, with subsequent transfer to the removal device 60. When aluminum wheels are being machined as workpieces 1, it is advisable for the ejector unit 80 to engage the wheel center to avoid damaging the sensitive aluminum workpiece. The wall thickness is greatest in the wheel center.

[0043] If steel wheels or steel wheel discs are machined as workpieces 1, it is advisable for the stripper unit 81 to engage the outer edge of the workpiece in order to avoid damaging the sensitive steel workpiece and / or to raise it to the removal level by the stripper plate 82. The actuating cylinders are integrated, if possible, symmetrically to the center in the machine base 26.

[0044] A second drive 22 is arranged on the machine upper bed 28, which drives a tailstock spindle 20 in rotation about the rotational axis 18 via a conventional gear device. The tailstock spindle 20 and the second drive 22 are mounted on a horizontally directed, plate-shaped, and box-like stiffened carriage 21, which is axially movable along the vertical machine columns 30. For this purpose, hydraulic actuating cylinders 23 are provided on the machine upper bed 28. The main spindle 12 and the coaxial tailstock spindle 20 are arranged in the work space 5, which is bounded by the three machine columns 30. The tailstock spindle 20 can be provided with an axially displaceable pressure extension 25 with a pressure ring 27, which projects beyond a first pressure extension with a pressure disk.

[0045] Each machine stand 30 is constructed from two box-shaped columns 31, between which a free space is formed. Roller supports 36 with a forming roller 37 can be mounted in this free space, as is clearly shown in Fig. 4. The radial roller supports 36 are aligned horizontally. The three radial roller supports 36 can be arranged offset from one another by 120 degrees. In the illustrated embodiment, the feed drive in the radial direction is carried out by a servo-controlled hydraulic cylinder, just as the vertical adjustment in the axial direction is carried out by a servo-controlled hydraulic cylinder. They can also be electric. The roller supports 36 can each be mechanically movable completely independently of one another, with radial and axial feed for the forming rollers 37.

[0046] At the third passage area 34c, an additional machining unit 40 for performing a further machining operation on the workpiece can be provided. The structure of the machine frame 24 is clearly illustrated in Fig. 5. In addition to the stiffening provided by the carriage, the column-shaped machine stands 30 can be connected to the adjacent machine stand 30 via horizontal cross braces 32 in their respective central regions, thus providing additional stiffening. The arrangement of a roller support 36 between the two box-shaped columns 31 of a machine stand 30 is also clearly shown in Fig. 5.

[0047] According to section AA in Fig. 6, the inventive guidance of the carriage 21 along the machine stands 30 is illustrated, with the sectional view being shown in Fig. 7. Two linear guides 90 are arranged along each machine stand 30, which run parallel to the rotation axis 18.

[0048] Each linear guide 90 has a rail-like guide rail 92, which is attached to a radial inner side of one of the machine stands 30. Concave recesses are provided on the sides of the guide rails 92 to form a lateral undercut. Corresponding U-shaped guide elements 96 are attached to the facing sides of the carriage 21, which engage with projections into the recesses of the guide rails 92. Radially directed forces can be absorbed by the guide elements 96 via radially outwardly directed guide surfaces 94. Thus, the carriage 21 can contribute to further stiffening the machine frame 24, which significantly improves dimensional accuracy, particularly when forming large vehicle wheels.

Claims

PROTECTION CLAIMS 1. Forming machine for spinning and flow-forming, comprising a vertically directed main spindle (12) on which a forming tool (14) is arranged, a first drive (16) with which the main spindle (12) can be driven to rotate about a vertically directed axis of rotation (18), a tailstock spindle (20) arranged coaxially to the main spindle (12) and axially movable relative thereto, a machine base (26) and a machine top bed (28) connected to one another via at least three vertically directed machine stands (30), wherein the main spindle (12) is arranged on the machine base (26) and the at least three machine stands (30) are arranged distributed around the axis of rotation (18), which define a work space (5), and at least one forming roller (37) guided axially movable and radially adjustable along at least one machine stand (30), characterized in thatthat the tailstock spindle (20) is arranged on a carriage (21) which is axially guided and mounted on the at least three machine stands (30) with at least one linear guide (90) in each case in such a way that the carriage (21) stiffens the machine stands (30) against bending outwards in the radial direction. Forming machine according to claim 1, characterized in that the at least one linear guide (90) is designed to engage behind in the radial direction. Forming machine according to claim 1 or 2, characterized in that at least one linear guide rail (92) is formed on each of the machine stands (30), which guide rail has a radially outward-facing guide surface (94), and in that each guide rail (92) is assigned at least one guide element (96), which is mounted on the carriage (21) and bears against the radially outward-facing guide surface (94) of the assigned guide rail (92) for guiding the carriage (21). Forming machine according to one of claims 1 to 3, characterized in that a second drive (22) is arranged on the carriage (21), with which drive the tailstock spindle (20) can be driven to rotate about the rotation axis (18).Forming machine according to one of claims 1 to 4, characterized in that a roller support (36) for at least one forming roller (37) is displaceably guided along at least one machine stand (30), and that the roller support (36) is provided with an axial feed drive and a radial feed drive for the forming roller (37). Forming machine according to one of claims 1 to 5, characterized in that each machine stand (30) has two box-shaped columns (31), between which a free space is formed, and that at least one roller support (36) for the forming roller (37) is displaceably guided in the free space. Forming machine according to claim 5 or 6, characterized in that a roller support (36) is guided on each of the machine stands (30). Forming machine according to one of claims 1 to 7, characterized in that the at least one forming roller (37) is arranged at an angle of 5° to 20° to the axis of rotation (18). Forming machine according to one of claims 1 to 8, characterized in that a forming roller drive is provided for at least one forming roller (37), with which the forming roller (37) can be driven at a predetermined speed. Forming machine according to one of claims 1 to 9, characterized in that at least one processing unit (40) with a forming roller (37) is arranged in a passage area (34) between two machine stands (30).Forming machine according to one of claims 1 to 10, characterized in that a connecting device for connecting and lifting the forming tool (14) from the main spindle (12) is arranged on the axially movable carriage (21). Forming machine according to one of claims 1 to 11, characterized in that a tool changing device is arranged on the machine base (26), which is designed to feed and / or remove the forming tool (14) to or from the main spindle (12). Forming machine according to one of claims 1 to 12, characterized in that the tailstock spindle (20) is provided with a pressure extension with a pressure disk. Forming machine according to one of claims 1 to 13, characterized in that the forming machine (10) is designed for forming steel wheel discs and / or steel wheels. Forming machine according to one of claims 1 to 14, characterized in that the tailstock spindle (20) is designed with a measuring device as a positioning axis. Forming machine according to one of claims 1 to 15, characterized in that the contact pressure of the tailstock spindle (20) is adjustable and / or programmable. Forming machine according to one of claims 1 to 15, characterized in that the tailstock spindle (20) is provided with a first axially displaceable contact pressure extension (25) with a contact pressure ring (27), which preferably projects beyond a second contact pressure extension with a contact pressure disk. Forming machine according to one of claims 1 to 16, characterized in that an ejector unit (80) is arranged on the main spindle (12) and / or the tailstock spindle (20).Forming machine according to one of claims 1 to 16, characterized in that the tailstock spindle (20) is designed to accommodate an additional forming tool. Forming machine according to one of claims 1 to 16, characterized in that the carriage (21) is designed to accommodate forming rollers (37). Forming machine according to one of claims 1 to 20, characterized in that a CNC control is provided that supports a complete virtual representation of the development process and / or commissioning of the forming machine. Forming machine according to one of claims 1 to 20, characterized in that the machine stands (30) are connected to one another in their central regions via cross struts (32).

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