Machine tool

Abstract

The invention relates to a machine tool (1) comprising: - a machine frame (6); a first work spindle (7), which is mounted rotatably about a first spindle axis (11); - a second work spindle (8), which is mounted rotatably about a second spindle axis (12); - a workpiece clamping device (19) having a first workpiece receiving space (22), which is designed to receive at least one first workpiece (2), and a second workpiece receiving space (23), which is designed to receive a second workpiece (3), wherein the workpiece clamping device (19) comprises a swivelling bridge (20), which is mounted such that it can swivel about a swivel axis (21). The swivelling bridge (20) is designed in the form of a frame structure. The first workpiece receiving space (22) is located on a first workpiece table (34). The second workpiece receiving space (23) is located on a second workpiece table (38).

Description

[0001] MACHINE TOOL

[0002] The invention relates to a machine tool and a method for machining a first workpiece and a second workpiece using the machine tool.

[0003] EP2522457A1 discloses a machine tool for machining workpieces and comprises a vertical wall with a wall opening, a Y-slide vertically movable within the wall opening, which is guided movably on the vertical wall and carries a horizontally movable Z-slide with at least one horizontal tool spindle, and a workpiece carrier arranged in front of the wall opening, which is movable horizontally in the X-direction and whose horizontal guides are arranged on the outside of the vertical wall.

[0004] The EP2522457A1 machine tool has the disadvantage of offering limited flexibility in terms of machining different workpieces.

[0005] To increase the flexibility of a machine tool, the number of drives can be increased. However, increasing the number of drives simultaneously increases the complexity of the machine tool. Due to the infinite number of possible machine tool configurations, finding an optimal configuration that offers sufficient flexibility for specific workpieces while maintaining the lowest possible complexity is very complex.

[0006] The object of the present invention was to overcome the disadvantages of the prior art and to provide a machine tool that exhibits increased flexibility. At the same time, the increased flexibility of the machine tool is intended to keep its complexity low.

[0007] This problem is solved by a device and a method according to the claims.

[0008] The invention relates to a machine tool comprising:

[0009] - a machine frame;

[0010] - a first working spindle which is rotatably mounted about a first spindle axis;

[0011] - a second working spindle, which is rotatably mounted about a second spindle axis;

[0012] - A workpiece clamping device with a first workpiece holding position, which is designed to hold at least one first workpiece, and a second workpiece holding position, which is designed to hold a second workpiece, wherein the first working spindle is assigned to the first workpiece holding position and the second working spindle is assigned to the second workpiece holding position, wherein the workpiece clamping device includes a swivel bridge which is pivotably mounted about a pivot axis. The swivel bridge is designed as a frame structure with a left side member, a right side member, a first connecting member and a second connecting member, wherein the left side member and the right side member are coupled to each other by means of the first connecting member and by means of the second connecting member, and wherein a left pivot bearing is provided.which is coupled to the left side panel and a right pivot bearing is formed, which is coupled to the right side panel, wherein the pivot bridge is pivotably mounted on the machine frame about the pivot axis by means of the left pivot bearing and the right pivot bearing, wherein the first workpiece holding position is arranged on a first workpiece table, wherein the first workpiece table is pivotably mounted on the pivot bridge about a first workpiece table pivot axis by means of a first front workpiece table bearing and a first rear workpiece table bearing, and wherein the second workpiece holding position is arranged on a second workpiece table, wherein the second workpiece table is pivotally mounted on the pivot bridge about a second workpiece table pivot axis by means of a second front workpiece table bearing and a second rear workpiece table bearing.

[0013] The machine tool according to the invention offers the surprising advantage that, despite increasing the flexibility of the machine tool, the number of necessary drives can be kept to a minimum, thus minimizing the complexity of the machine tool. In particular, two or more workpieces can be machined simultaneously using the machine tool according to the invention, while keeping the space requirement of the machine tool to a minimum.

[0014] Furthermore, it can be advantageous if the first spindle axis is arranged parallel to a horizontal Z-axis and the second spindle axis is also arranged parallel to the horizontal Z-axis. This offers the surprising advantage that, in combination with the swivel bridge according to the invention, improved machining quality can be achieved. Additionally, it can be provided that the first and second working spindles are arranged side by side at a distance from each other along a horizontal X-axis, and that the first and second workpiece holding positions are arranged side by side at a distance from each other along the horizontal X-axis, with the swivel axis aligned parallel to the horizontal X-axis. This offers the surprising advantage that, in combination with the swivel bridge according to the invention, improved machining quality can be achieved.

[0015] Furthermore, it may be provided that a third working spindle is provided, which is rotatably mounted about a third spindle axis, and a fourth working spindle is provided, which is rotatably mounted about a fourth spindle axis, and that the workpiece clamping device comprises a third workpiece holding position, which is designed to hold at least one third workpiece, and a fourth workpiece holding position, which is designed to hold a fourth workpiece, wherein the third working spindle is assigned to the third workpiece holding position and the fourth working spindle is assigned to the fourth workpiece holding position, wherein the third workpiece holding position is arranged on a third workpiece table.wherein the third workpiece table is pivotably mounted on the swivel bridge about a third workpiece table pivot axis by means of a third front workpiece table bearing and a third rear workpiece table bearing, and wherein the fourth workpiece holding position is arranged on a fourth workpiece table, wherein the fourth workpiece table is pivotally mounted on the swivel bridge about a fourth workpiece table pivot axis by means of a fourth front workpiece table bearing and a fourth rear workpiece table bearing. This measure further increases the flexibility of the machine tool.

[0016] An advantageous embodiment also includes a first intermediate strut between the first workpiece table swivel axis and the second workpiece table swivel axis, wherein the first intermediate strut is arranged parallel to the left side panel, wherein the first intermediate strut is coupled steeply to the first connection and steeply to the second connection, and wherein a second intermediate strut is formed between the second workpiece table swivel axis and the third workpiece table swivel axis, wherein the second intermediate strut is arranged parallel to the left side panel, wherein the second intermediate strut is coupled steeply to the first connection and steeply to the second connection, and wherein a third intermediate strut is formed between the third workpiece table swivel axis and the fourth workpiece table swivel axis, wherein the third intermediate strut is arranged parallel to the left side panel.The third intermediate strut is coupled steeply to the first connection and steeply to the second connection. This has the advantage of improving the stability of the swing bridge, thereby improving the quality of the manufactured workpieces.

[0017] According to a further development, it is possible that a first bracket is arranged on the first intermediate strut, on which the first rear workpiece table support is received, wherein the first bracket is arranged at a first bracket distance from the second connecting part; that a second bracket is arranged on the second intermediate strut, on which the second rear workpiece table support is received, wherein the second rear workpiece table support is arranged at a second bracket distance from the second connecting part; that a third bracket is arranged on the third intermediate strut, on which the third rear workpiece table support is received, wherein the third bracket is arranged at a third bracket distance from the second connecting part; and that a fourth bracket is arranged on the left side part.on which the fourth rear workpiece table support is mounted, with the fourth support being arranged at a fourth support distance from the second connecting part. This has the advantage that this measure allows the distance between the front workpiece table support and the rear workpiece table support to be shortened, thereby reducing the deflection of the workpiece table and thus improving the quality of the workpieces, in particular their dimensional accuracy.

[0018] In an alternative design variant, the first, second, third, and fourth rear workpiece table bearings can be arranged on the second connecting part. This offers the advantage that, with such a swivel bridge, the individual workpiece tables can be rotated 360° around the workpiece table pivot axis. Furthermore, a first swivel motor can be provided, allowing the first workpiece table to be rotated around the first workpiece table pivot axis, and a second swivel motor can be provided, allowing the second workpiece table to be rotated around the second workpiece table pivot axis. This offers the advantage that, by providing a separate swivel motor for each workpiece table, the workpiece tables can be rotated individually and independently of one another.This measure can therefore increase the flexibility of the machine tool.

[0019] Furthermore, it can be advantageous to have a third swivel motor, by means of which the third workpiece table can be swiveled about the third workpiece table swivel axis, and a fourth swivel motor, by means of which the fourth workpiece table can be swiveled about the fourth workpiece table swivel axis. This offers the advantage that, by providing a separate swivel motor for each workpiece table, the workpiece tables can be swiveled individually and independently of one another. This measure thus increases the flexibility of the machine tool.

[0020] Furthermore, it can be provided that the first, second, third, and fourth rotary actuators are each designed as hydraulic motors, with the rotary actuators being coupled via a common power supply and connected in parallel, and the workpiece tables being pivotable between a first and a second rotation angle limit. This offers the advantage of enabling simple pivoting of the individual workpiece tables and keeping the overall design of the machine tool as simple as possible. The rotation angle limit and the parallel hydraulic motors allow for the simplest possible control of the rotary actuators when the workpiece tables only need to be pivoted between the first and second rotation angle positions.The parallel connection of the hydraulic motors ensures that all hydraulic motors operate against their respective rotation angle limits, thus allowing all hydraulic motors to assume the same angular position despite the parallel connection of the oil supply lines. In an alternative embodiment, the individual rotary motors can be designed as electric motors, particularly servo motors, preferably torque motors, and can be swiveled independently of one another. This offers the advantage that the workpiece tables can be swiveled individually and independently of each other, further increasing the flexibility of the machine tool.

[0021] Furthermore, it can be provided that the swivel motors are each arranged at the front workpiece table bearing.

[0022] In an alternative design, the swivel motors can be arranged on the rear workpiece table bearing.

[0023] Another alternative design allows for the installation of swivel motors at both the front and rear workpiece table bearings. This offers the advantage of a symmetrical weight distribution around the swivel axis of the swivel bridge.

[0024] Another advantageous configuration allows the first work spindle to be moved along the X-axis by means of a first X-axis adjustment unit, and the second work spindle to be moved along the X-axis by means of a second X-axis adjustment unit, with the first and second work spindles being independently movable along the X-axis. This measure further increases the flexibility of the machine tool.

[0025] According to further training, it is possible for the first working spindle to be displaceable along the Z-axis by means of a first Z-axis adjustment unit, and for the second working spindle to be displaceable along the Z-axis by means of a second Z-axis adjustment unit, whereby the first and second working spindles can be displaced independently of each other along the Z-axis. This measure can further increase the flexibility of the machine tool.

[0026] Furthermore, it can be advantageous if the swivel bridge can be moved along a vertical Y-axis by means of a Y-axis adjustment unit. This measure can further increase the flexibility of the machine tool, while simultaneously keeping the machine tool's design as simple as possible.

[0027] Furthermore, the swivel bridge can be designed to be displaceable along a horizontal Z-axis by means of a Z-axis adjustment unit. This measure further increases the flexibility of the machine tool while simultaneously keeping its design as simple as possible.

[0028] According to the invention, a method for machining a first workpiece and a second workpiece is provided using a machine tool, in particular using a machine tool according to one of the preceding claims. The machine tool comprises:

[0029] - a machine frame;

[0030] - a first working spindle which is rotatably mounted about a first spindle axis;

[0031] - a second working spindle, which is rotatably mounted about a second spindle axis;

[0032] - a workpiece clamping device with a first workpiece holding position, which is designed to hold at least one first workpiece, and a second workpiece holding position, which is designed to hold a second workpiece, wherein the first working spindle is assigned to the first workpiece holding position and the second working spindle is assigned to the second workpiece holding position, wherein the workpiece clamping device comprises a swivel bridge which is pivotably mounted about a pivot axis, wherein the swivel bridge is designed as a frame construction with a left side part, a right side part, a first steep connection and a second steep connection, wherein the left side part and the right side part are coupled to each other by means of the first connecting part and by means of the second connecting part, wherein a left pivot bearing is provided,which is coupled to the left side panel and a right pivot bearing is formed, which is coupled to the right side panel, wherein the pivot bridge is pivotably mounted on the machine frame about the pivot axis by means of the left pivot bearing and the right pivot bearing, wherein the first workpiece holding position is arranged on a first workpiece table, wherein the first workpiece table is pivotably mounted on the pivot bridge about a first workpiece table pivot axis by means of a first front workpiece table bearing and a first rear workpiece table bearing, and wherein the second workpiece holding position is arranged on a second workpiece table, wherein the second workpiece table is pivotally mounted on the pivot bridge about a second workpiece table pivot axis by means of a second front workpiece table bearing and a second rear workpiece table bearing.

[0033] The procedure comprises the following steps:

[0034] - Machining of the first workpiece picked up in the first workpiece holding station using the first work spindle;

[0035] - Machining the second workpiece, which is held in the second workpiece holding station, using the second working spindle.

[0036] The method according to the invention offers the surprising advantage that, despite increasing the flexibility of the machine tool, the number of necessary drives can be kept to a minimum, thus minimizing the complexity of the machine tool. In particular, two or more workpieces can be machined simultaneously using the machine tool according to the invention, while keeping the space requirement of the machine tool to a minimum.

[0037] Furthermore, it can be provided that the first workpiece and the second workpiece are each a cylinder head, a crankcase, a camshaft carrier, a camshaft bearing housing, or a camshaft bearing frame of an internal combustion engine, and that the first workpiece is clamped at the first workpiece holding position and the second workpiece is clamped at the second workpiece holding position such that the pivot axis runs transversely to the longitudinal extension of the cylinder head, the crankcase, the camshaft carrier, the camshaft bearing housing, or the camshaft bearing frame, wherein in a first pivot position of the swivel bridge about the pivot axis a top or a bottom or a first broad side or a second broad side, in particular a valve seat or an inlet channel of the cylinder head, the crankcase, the camshaft carrier, the camshaft bearing housing, or the camshaft bearing frame,The machining process involves machining a first end face or a second end face, particularly oil channels or a camshaft seat of the cylinder head, crankcase, camshaft carrier, camshaft bearing housing, or camshaft bearing frame, in a second pivot position of the swivel bridge about the pivot axis. The inventive method and machine tool are particularly advantageous for such components due to their shape and the machining steps required for these components. The presence of multiple workpiece tables on the swivel bridge allows several components to be mounted simultaneously and thus machined efficiently.

[0038] A cylinder head, a crankcase, a camshaft carrier, a camshaft bearing housing, or a camshaft bearing frame, as defined in this document, is a component of an internal combustion engine. These components can also be referred to as core components of the internal combustion engine.

[0039] The cylinder head has a bottom surface facing the crankcase and / or the pistons. Opposite this bottom surface, the cylinder head has a top surface. Several pistons can be arranged side by side within the cylinder. This is referred to as the longitudinal extent of the cylinder and, correspondingly, the longitudinal extent of the cylinder head. The longitudinal extent of the cylinder head is bounded by a first end face and a second end face. Transversely to its longitudinal extent, the cylinder head is bounded by a first broad side and a second broad side. In particular, the longitudinal extent of the cylinder head may be greater than its transverse extent.

[0040] This definition of orientation, as established using the cylinder head, is also applied to the crankcase, camshaft carrier, camshaft bearing housing, or camshaft bearing frame, assuming the same orientation when the components are assembled. The top of the crankcase faces the cylinder head.

[0041] To better understand the invention, it is explained in more detail with reference to the following figures.

[0042] They each show, in a highly simplified, schematic representation:

[0043] Fig. 1 is a perspective view of a schematically represented first embodiment of a swivel bridge of a machine tool; Fig. 2 is a perspective view of a schematically represented second embodiment of the swivel bridge of the machine tool;

[0044] Fig. 3 shows a perspective view of a schematically represented third embodiment of the swivel bridge of the machine tool;

[0045] Fig. 4 shows a perspective view of a schematically represented fourth embodiment of the swivel bridge of the machine tool;

[0046] Fig. 5 shows a perspective view of a schematically represented fifth embodiment of the swivel bridge of the machine tool;

[0047] Fig. 6 shows a first embodiment of an axle assembly of a machine tool in a first perspective view;

[0048] Fig. 7 shows the first embodiment of the axle assembly of the machine tool in a front view;

[0049] Fig. 8 shows a detail of the four working spindles of the first embodiment of the axis assembly of the machine tool in a first perspective view;

[0050] Fig. 9 shows a detail of the four working spindles of the first embodiment of the axis assembly of the machine tool in a second perspective view;

[0051] Fig. 10 shows a detail of the four working spindles of a second embodiment of the axis structure of the machine tool in a first perspective view;

[0052] Fig. 11 shows a detail of four X-axis adjustment units of a third embodiment of the axis structure of the machine tool in a top view;

[0053] Fig. 12 shows a highly simplified side view of a fourth embodiment of the machine tool.

[0054] It should be noted at the outset that in the differently described embodiments, identical parts are provided with the same reference numerals or component designations, and the disclosures contained in the entire description can be applied analogously to identical parts with the same reference numerals or component designations. Furthermore, the positional designations chosen in the description, such as top, bottom, side, etc., refer to the figure directly described and illustrated, and these positional designations must be applied analogously to the new position if the position changes.

[0055] Figure 1 shows a schematic representation of a first embodiment of a machine tool 1 for machining workpieces 2, 3, 4, 5 in a perspective view.

[0056] In particular, it may be provided that the machine tool 1 is used for machining a first workpiece 2, a second workpiece 3, a third workpiece 4 and a fourth workpiece 5.

[0057] The machine tool 1 has a machine frame 6, which serves as a base for the components attached to it.

[0058] For the sake of clarity, the machine frame 6 is shown only schematically in Fig. 1. It should be noted, however, that the machine frame 6 can be anchored at the installation site. Furthermore, the machine frame 6 can, of course, serve to support all components of the machine tool 1. The machine frame 6 itself can also comprise several components.

[0059] Furthermore, the machine tool 1 may comprise a first working spindle 7, a second working spindle 8, a third working spindle 9, and a fourth working spindle 10. The first working spindle 7 may be rotatably mounted about a first spindle axis 11. The second working spindle 8 may be rotatably mounted about a second spindle axis 12. The third working spindle 9 may be rotatably mounted about a third spindle axis 13. The fourth working spindle 10 may be rotatably mounted about a fourth spindle axis 14.

[0060] Furthermore, the individual spindle axes 11, 12, 13, 14 of the work spindles 7, 8, 9, 10 can be arranged parallel to a horizontal Z-axis 15. The individual work spindles 7, 8, 9, 10 can also be arranged at a distance with respect to a horizontal X-axis 16. A Y-axis 17 can be formed at right angles to the Z-axis 15 and the X-axis 16.

[0061] Furthermore, it can be provided that the individual working spindles 7, 8, 9, 10 each serve to hold a machining tool 18, by means of which the workpieces 2, 3, 4, 5 can be machined. As can be seen particularly well from Fig. 1, it can also be provided that a workpiece clamping device 19 is designed, which serves to hold the first workpiece 2, the second workpiece 3, the third workpiece 4 and the fourth workpiece 5.

[0062] The workpiece clamping device 19 can have a swivel bridge 20. The swivel bridge 20 can be pivotally mounted about a pivot axis 21 relative to the machine frame 6. In particular, it can be provided that the first pivot axis 21 is arranged parallel to the X-axis 16.

[0063] Furthermore, the swivel bridge 20 can be mounted on the machine frame 6 in a way that allows it to be displaceable relative to the machine frame 6. This displaceability can be achieved in the X-axis 16, the Y-axis 17, or the Z-axis 15.

[0064] The swivel bridge 20 can have a first workpiece holding position 22, a second workpiece holding position 23, a third workpiece holding position 24 and a fourth workpiece holding position 25.

[0065] Furthermore, the swing bridge 20 can be designed as a frame structure with a left side section 28, a right side section 29, a first steep connection 30, and a second connecting section 31. It can also be provided that the left side section 28 and the right side section 29 are coupled to each other by means of the first connecting section 30 and the second connecting section 31.

[0066] Furthermore, it can be provided that a left pivot bearing 32 and a right pivot bearing 33 are formed, by means of which the pivot bridge 20 is pivotably mounted on the machine frame 6 about the pivot axis 21.

[0067] In particular, it can be provided that the left pivot bearing 32 is coupled to the left side panel 28 and the right pivot bearing 33 is coupled to the right side panel 29. In particular, it can be provided that the pivot bridge 20 is pivotably mounted on the machine frame 6 about the pivot axis 21 by means of the left pivot bearing 32 and the right pivot bearing 33. This can be achieved either by directly coupling the left pivot bearing 32 and the right pivot bearing 33 to the machine frame 6 or by slidably coupling the left pivot bearing 32 and the right pivot bearing 33 to the machine frame 6. Furthermore, it can be provided that the first workpiece holding position 22 is arranged on a first workpiece table 34.Furthermore, it can be provided that the first workpiece table 34 is pivotably mounted on the swivel bridge 20 by means of a first front workpiece table bearing 35 and a first rear workpiece table bearing 36 about a first workpiece table swivel axis 37.

[0068] Furthermore, it can be provided that the second workpiece holding position 23 is arranged on a second workpiece table 38. It can also be provided that the second workpiece table 38 is pivotably mounted on the swivel bridge 20 by means of a second front workpiece table bearing 39 and a second rear workpiece table bearing 40 about a second workpiece table swivel axis 41.

[0069] Furthermore, it can be provided that the third workpiece holding position 24 is arranged on a third workpiece table 42. It can also be provided that the third workpiece table 42 is pivotably mounted on the swivel bridge 20 by means of a third front workpiece table bearing 43 and a third rear workpiece table bearing 44 about a third workpiece table swivel axis 45.

[0070] Furthermore, it can be provided that the fourth workpiece holding position 25 is arranged on a fourth workpiece table 46. It can also be provided that the fourth workpiece table 46 is pivotably mounted on the swivel bridge 20 by means of a fourth front workpiece table bearing 47 and a fourth rear workpiece table bearing 48 about a fourth workpiece table swivel axis 49.

[0071] Furthermore, it can be provided that a first intermediate strut 50 is formed between the first workpiece table swivel axis 37 and the second workpiece table swivel axis 41, wherein the first intermediate strut 50 is arranged parallel to the left side part 28. In particular, it can be provided that the first intermediate strut 50 is coupled to the first connecting part 30 and the second connecting part 31.

[0072] Furthermore, it may be provided that a second intermediate strut 51 is formed between the second workpiece table swivel axis 41 and the third workpiece table swivel axis 45, wherein the second intermediate strut 51 is arranged parallel to the left side panel 28, and wherein the second intermediate strut 51 is coupled to the first connecting part 30 and the second connecting part 31. Furthermore, it may be provided that a third intermediate strut 52 is formed between the third workpiece table swivel axis 45 and the fourth workpiece table swivel axis 49, wherein the third intermediate strut 52 is arranged parallel to the left side panel 28, and wherein the third intermediate strut 52 is coupled to the first connecting part 30 and the second connecting part 31.

[0073] Furthermore, a first swivel motor 53 may be provided, by means of which the first workpiece table 34 can be swivelled about the first workpiece table swivel axis 37. The first swivel motor 53 can be arranged in the area of ​​the first front workpiece table bearing 35. Alternatively, it is also conceivable that the first swivel motor 53 is arranged in the area of ​​the first rear workpiece table bearing 36. In a further alternative, it is also conceivable that the first swivel motor 53 is arranged at the first front workpiece table bearing 35 and that, in addition, a further first swivel motor 53 is arranged at the first rear workpiece table bearing 36.

[0074] Furthermore, a second swivel motor 54 may be provided, by means of which the second workpiece table 38 can be swivelled about the second workpiece table swivel axis 41. The second swivel motor 54 can be arranged in the area of ​​the second front workpiece table bearing 39. Alternatively, it is also conceivable that the second swivel motor 54 is arranged in the area of ​​the second rear workpiece table bearing 40. In a further alternative, it is also conceivable that the second swivel motor 54 is arranged at the second front workpiece table bearing 39 and that, in addition, a further second swivel motor 54 is arranged at the second rear workpiece table bearing 40.

[0075] Furthermore, a third swivel motor 55 may be provided, by means of which the third workpiece table 42 can be swivelled about the third workpiece table swivel axis 45. The third swivel motor 55 can be arranged in the area of ​​the third front workpiece table bearing 43. Alternatively, it is also conceivable that the third swivel motor 55 is arranged in the area of ​​the third rear workpiece table bearing 44. In a further alternative, it is also conceivable that the third swivel motor 55 is arranged at the third front workpiece table bearing 43 and that, in addition, a further third swivel motor 55 is arranged at the third rear workpiece table bearing 44.

[0076] Furthermore, a fourth swivel motor 56 may be provided, by means of which the fourth workpiece table 46 can be swivelled about the fourth workpiece table swivel axis 49. The fourth swivel motor 56 can be arranged in the area of ​​the fourth front workpiece table bearing 47. Alternatively, it is also conceivable that the fourth swivel motor 56 is arranged in the area of ​​the fourth rear workpiece table bearing 48. In a further alternative, it is also conceivable that the fourth swivel motor 56 is arranged at the fourth front workpiece table bearing 47 and that, in addition, a further fourth swivel motor 56 is arranged at the fourth rear workpiece table bearing 48.

[0077] As can be further seen from Fig. 1, it can be provided that the first workpiece 2, the second workpiece 3, the third workpiece 4 and the fourth workpiece 5 are each a cylinder head. The workpieces 2, 3, 4, 5 in the form of cylinder heads can each be mounted on the workpiece table 34, 38, 42, 46 such that the pivot axis 21 runs transversely to the longitudinal extent of the cylinder head.

[0078] In a second pivot position of the swivel bridge 20 about the pivot axis 21, as shown in Fig. 1, a first end face, in particular oil channels or a camshaft seat of the cylinder head, can be machined.

[0079] If the swivel bridge 20 is now pivoted rearward about the pivot axis 21, approximately by 90°, then in a first pivot position of the swivel bridge 20 about the pivot axis 21, a top surface, in particular a valve seat of the cylinder head, can be machined. The individual workpiece tables 34, 38, 42, 46 can be pivoted about their respective workpiece table pivot axes 37, 41, 45, 49, for example, to be able to machine intake valve seats in a first machining step and exhaust valve seats arranged in a V-shape in a second machining step.

[0080] Figure 2 shows a further, and possibly independent, embodiment of the machine tool 1, whereby the same reference numerals or component designations are used for identical parts as in the preceding Figure 1. To avoid unnecessary repetition, reference is made to the detailed description in the preceding Figure 1.

[0081] As can be seen in Fig. 2, the individual spindle axes 11, 12, 13, 14 can be vertically aligned, and the working spindles 7, 8, 9, 10 can be arranged above the swivel bridge 20. Accordingly, the Z-axis 15 can also be vertically aligned, and the Y-axis 17 horizontally aligned. The swivel positions of the swivel bridge 20 during the machining of workpieces 2, 3, 4, 5 are to be adapted mutatis mutandis to the description in Fig. 1.

[0082] Figure 3 shows another, and possibly independent, embodiment of the machine tool 1, whereby the same reference numerals and component designations are used for identical parts as in the preceding Figure 1. To avoid unnecessary repetition, reference is made to the detailed description in the preceding Figure 1.

[0083] As can be seen in Fig. 3, the pivot axis 21 of the pivot bridge 20 can be vertically oriented and thus parallel to the Y-axis 17. As in Fig. 1, the individual spindle axes 11, 12, 13, 14 can be horizontally oriented. In contrast to the embodiment shown in Fig. 1, the working spindles 7, 8, 9, 10 can be arranged one above the other with respect to the Y-axis 17.

[0084] Figure 4 shows another, and possibly independent, embodiment of the machine tool 1, whereby the same reference numerals and component designations are used for identical parts as in the preceding Figure 1. To avoid unnecessary repetition, reference is made to the detailed description in the preceding Figure 1.

[0085] As can be seen in Fig. 4, the machine tool 1 can be designed to have only the first workpiece holding position 22 and the second workpiece holding position 23. Accordingly, it can be designed to have only the first working spindle 7 and the second working spindle 8. Other components, such as struts, can also be reduced accordingly.

[0086] In other, not shown, versions it is also conceivable that three or more workpiece holding positions or work spindles are used.

[0087] Figure 5 shows another, and optionally independent, embodiment of the machine tool 1, using the same reference numerals and component designations for identical parts as in the preceding Figure 1. To avoid unnecessary repetition, reference is made to the detailed description in the preceding Figure 1. As can be seen in Figure 5, a first support 57 may be arranged on the first intermediate strut 50, on which the first rear workpiece table bearing 36 is mounted. The first support 57 may be arranged at a first mounting distance 61 from the second connection 31. In Figure 5, the first workpiece table 34 is omitted for clarity.

[0088] Furthermore, it can be provided that a second bracket 58 is arranged on the second intermediate strut 51, on which the second rear workpiece table support 40 is received. The second rear workpiece table support 40 can be arranged at a second bracket distance 62 from the second connecting part 31.

[0089] Furthermore, it can be provided that a third bracket 59 is arranged on the third intermediate strut 52, on which the third rear workpiece table bearing 44 is mounted. The third bracket 59 can be arranged at a third bracket distance 63 from the second connection 31.

[0090] Furthermore, a fourth bracket 60 may be arranged on the left side panel 28, on which the fourth rear workpiece table support 48 is mounted. The fourth bracket 60 may be arranged at a fourth bracket distance 64 from the second connection 31.

[0091] Furthermore, a connecting element 104 may be arranged below the individual supports 57, 58, 59, 60. The connecting element 104 can serve to support the individual supports 57, 58, 59, 60 and thus increase the stability of the swing bridge 20.

[0092] In the embodiment according to Fig. 5, the first rotary motor 53 (not shown), the second rotary motor 54, the third rotary motor 55, and the fourth rotary motor 56 can each be designed as hydraulic motors. Furthermore, the workpiece tables 34, 38, 42, 46 can each be pivoted between a first rotation angle limit 65 and a second rotation angle limit 66. The first rotation angle limit 65 can be the upper surface of the intermediate struts 50, 51, 52 or the left side panel 28, against which the workpiece tables 34, 38, 42, 46 can rest in a position as shown in Fig. 5. The second rotation angle limit 66 can be a side surface of the intermediate struts 50, 51, 52 or the left side panel 28.of the left side part 28, on which the workpiece tables 34, 38, 42, 46 can rest in a position in which the workpiece tables 34, 38, 42, 46 are each pivoted by 90° with respect to the respective workpiece table pivot axis 37, 41, 45, 49 to the position shown in Fig. 5.

[0093] Furthermore, it is also conceivable that the first rotation angle limitation 65 or the second rotation angle limitation 66 are each directly formed in the swivel motors 53, 54, 55, 56.

[0094] Figure 6 shows a further, and possibly independent, embodiment of the machine tool 1, whereby the same reference numerals and component designations are used for identical parts as in the preceding Figures 1 to 5. To avoid unnecessary repetition, reference is made to the detailed description in the preceding Figures 1 to 5.

[0095] Figures 6 to 9 show schematic representations of a first embodiment of the axle assembly of machine tool 1 in various views. Machine tool 1 is described with reference to a combined view of Figures 6 to 9. It should be noted that, for the sake of clarity, not all reference numerals for the described components are included in each figure.

[0096] Figures 10, 11, and 12 show further possible configurations of the axis assembly of the machine tool 1. The different possible configurations of the axis assembly of the machine tool 1 according to Figures 6 to 9 and 10, 11, and 12 can be combined with the individual possible workpiece clamping devices 19 from the preceding Figures 1 to 5.

[0097] As can be seen in Fig. 6, the first working spindle 7 and the second working spindle 8 can be designed to be displaceable along the X-axis 16 by means of a first X-axis adjustment unit 67. Furthermore, the third working spindle 9 and the fourth working spindle 10 can be designed to be displaceable along the X-axis 16 by means of a second X-axis adjustment unit 68. In particular, the first X-axis adjustment unit 67 and the second X-axis adjustment unit 68 can be displaceable independently of each other along the X-axis 16. As can be seen particularly well in Fig. 8, a first X-axis guide rail 69 and a second X-axis guide rail 70 can be provided, which are arranged on the machine frame 6.

[0098] As can be seen from Fig. 9, it is possible to arrange several first guide slides 71 on the first X-axis adjustment unit 67. Individual first guide slides 71 can be guided on the first X-axis guide rail 69 and individual first guide slides 71 can be guided on the second X-axis guide rail 70.

[0099] In particular, as shown in Fig. 9, two of the first guide slides 71 are designed to interact with the first X-axis guide rail 69, and two of the first guide slides 71 are designed to interact with the second X-axis guide rail 70.

[0100] Furthermore, it can be provided that several second guide slides 72 are arranged on the second X-axis adjustment unit 68. Individual of the second guide slides 72 can be guided on the first X-axis guide rail 69 and individual of the second guide slides 72 can be guided on the second X-axis guide rail 70.

[0101] In particular, it may be provided that two of the second guide slides 72 are designed to interact with the first X-axis guide rail 69 and two of the second guide slides 72 are designed to interact with the second X-axis guide rail 70.

[0102] As can be seen from the individual figures, it can be provided that the first working spindle 7 and the second working spindle 8 are arranged together on the first X-axis adjustment unit 67 and are thus adjustable together along the X-axis 16.

[0103] Furthermore, it can be provided that the third working spindle 9 and the fourth working spindle 10 are arranged together on the second X-axis adjustment unit 68 and can thus be moved together along the X-axis 16.

[0104] As can be seen particularly well in Fig. 9, the first X-axis adjustment unit 67 can be coupled to a first X-axis drive unit 73. Furthermore, the second X-axis adjustment unit 68 can be coupled to a second X-axis drive unit 74. The first X-axis drive unit 73 and the second X-axis drive unit 74 can be used to move or position the first X-axis adjustment unit 67 and the second X-axis adjustment unit 68, respectively, along the X-axis 16. Thus, the first X-axis adjustment unit 67 and the second X-axis adjustment unit 68 can be moved individually and independently of each other along the X-axis 16.

[0105] As can be seen particularly well in Fig. 8, the first working spindle 7 can be mounted on the first X-axis adjustment unit 67 by means of a first Z-axis adjustment unit 75 so as to be displaceable in the Z-axis 15. Furthermore, the second working spindle 8 can be mounted on the first X-axis adjustment unit 67 so as to be displaceable in the direction of the Z-axis 15 by means of a second Z-axis adjustment unit 76.

[0106] Furthermore, it can be provided that the third working spindle 9 is slidably mounted on the second X-axis adjustment unit 68 by means of a third Z-axis adjustment unit 77. Furthermore, it can be provided that the fourth working spindle 10 is slidably mounted on the second X-axis adjustment unit 68 by means of a fourth Z-axis adjustment unit 78 along the Z-axis 15.

[0107] Furthermore, it may be provided that the first Z-axis adjustment unit 75 is mounted on the first X-axis adjustment unit 67 by means of a first Z-axis guide 79. Furthermore, it may be provided that the second Z-axis adjustment unit 76 is mounted on the first X-axis adjustment unit 67 by means of a second Z-axis guide 80. Furthermore, it may be provided that the third Z-axis adjustment unit 77 is mounted on the second X-axis adjustment unit 68 by means of a third Z-axis guide 81. Furthermore, it may be provided that the fourth Z-axis adjustment unit 78 is mounted on the second X-axis adjustment unit 68 by means of a fourth Z-axis guide 82.

[0108] The individual Z-axis guides 79, 80, 81, 82 can each have guide rails which are arranged on the first X-axis adjustment unit 67 or on the second X-axis adjustment unit 68 and can have guide carriages which are each arranged on the Z-axis adjustment unit 75, 76, 77, 78.

[0109] Furthermore, it may be provided that the first Z-axis adjustment unit 75 is adjustable relative to the first X-axis adjustment unit 67 by means of a first Z-axis drive unit 83. Furthermore, it may be provided that the second Z-axis adjustment unit 76 is adjustable relative to the second X-axis adjustment unit 68 by means of a second Z-axis drive unit 84. Furthermore, it may be provided that the third Z-axis adjustment unit 77 is adjustable relative to the first X-axis adjustment unit 67 by means of a third Z-axis drive unit 85. Furthermore, it may be provided that the fourth Z-axis adjustment unit 78 is adjustable relative to the second X-axis adjustment unit 68 by means of a fourth Z-axis drive unit 86. In particular, it can be provided that the individual working spindles 7, 8, 9, 10 can be moved individually and independently of each other along the Z-axis 15 by means of the individual Z-axis drive units 83, 84, 85, 86.

[0110] As can be seen from Figures 6 to 9, in the first embodiment of the axis configuration of the machine tool 1, the individual work spindles 7, 8, 9, 10 are not displaceable along the Y-axis 17. Instead, the individual work spindles 7, 8, 9, 10 can all be arranged at a common height.

[0111] Furthermore, it may be provided that a Y-axis adjustment unit 87 is designed, by means of which the swivel bridge 20 can be moved along the Y-axis 17.

[0112] Furthermore, it can be provided that the right pivot bearing 33 is coupled to a first mounting 88, wherein the first mounting 88 can be slidably mounted on the machine frame 6 along the Y-axis 17. Furthermore, it can be provided that the left pivot bearing 32 is coupled to a second mounting 89, wherein the second mounting 89 can be slidably mounted on the machine frame 6 along the Y-axis 17. In particular, it can be provided that first mounting guide slides 90 are arranged on the first mounting 88, which interact with a first Y-axis guide rail 91.

[0113] The first Y-axis guide rail 91 can be arranged on the machine frame 6. Furthermore, it can be provided that a second mounting guide slide 92 is arranged on the second mounting 89, which interacts with a second Y-axis guide rail 93. The second Y-axis guide rail 93 can also be arranged on the machine frame 6. Furthermore, it can be provided that a first Y-axis drive motor 94 is provided, by means of which the first mounting 88 can be displaced along the Y-axis 17. Furthermore, it can be provided that a second Y-axis drive motor 95 is provided, by means of which the second mounting 89 can be displaced along the Y-axis 17. In particular, it can be provided that the first Y-axis drive motor 94 and the second Y-axis drive motor 95 are operated synchronously with each other, so that the first pivot axis 21 is always parallel to the X-axis 16.

[0114] Furthermore, it may be provided that at least one swivel motor 96 is designed, by means of which the swivel bridge 20 can be swivelled about the first pivot axis 21. The swivel motor 96 can be arranged on one of the two pivot bearings 32, 33. It may also be provided that two swivel motors 96 are designed on one of the pivot bearings 32, 33.

[0115] Furthermore, it can also be provided that one or two of the swivel motors 96 are arranged at each of the swivel bearings 32, 33.

[0116] Figure 10 shows a second, and optionally independent, embodiment of the axis assembly of machine tool 1, whereby the same reference numerals and component designations are used for identical parts as in the preceding Figures 1 to 9. To avoid unnecessary repetition, reference is made to the detailed description in the preceding Figures 1 to 9.

[0117] For the sake of clarity, Fig. 10 shows only the individual working spindles 7, 8, 9, 10 together with their respective X-axis adjustment units 67, 68, 97, 98, whereby the remaining structure of the machine tool 1 can be the same as shown and described in the first embodiment.

[0118] As can be seen from Fig. 10, the third working spindle 9 can be arranged on a third X-axis adjustment unit 97. Furthermore, the fourth working spindle 10 can be arranged on a fourth X-axis adjustment unit 98. In particular, the third X-axis adjustment unit 97 can have third guide slides 99 by means of which the third X-axis adjustment unit 97 is slidably coupled to the first X-axis guide rail 69 or to the second X-axis guide rail 70.

[0119] Furthermore, it can be provided that the fourth X-axis adjustment unit 98 has a fourth guide slide 100, by means of which the fourth X-axis adjustment unit 98 is coupled to the first X-axis guide rail 69 or to the second X-axis guide rail 70 in the direction of the X-axis 16 in a displaceable manner. In this embodiment, the first working spindle 7, the second working spindle 8, the third working spindle 9, and the fourth working spindle 10 can be moved individually and independently of one another in the direction of the X-axis 16. Of course, in this third embodiment, it can be provided that each of the X-axis adjustment units 67, 68, 97, 98 is equipped with a separate drive.

[0120] Figure 11 shows a third and potentially independent embodiment of the axis assembly of machine tool 1, whereby the same reference numerals and component designations are used for identical parts as in the preceding Figures 1 to 9. To avoid unnecessary repetition, reference is made to the detailed description in the preceding Figures 1 to 10.

[0121] For the sake of clarity, only the individual working spindles 7, 8, 9, 10 together with their respective associated X-axis adjustment units 67, 68, 97, 98 are shown in simplified form in Fig. 11, whereby the remaining structure of the machine tool 1 can be the same as shown and described in the first embodiment of the axis structure of the machine tool 1.

[0122] As can be seen in Fig. 11, the second X-axis adjustment unit 68 can be coupled to the first X-axis adjustment unit 67 by means of a first X-axis compensation unit 101. The second X-axis adjustment unit 68 is therefore not completely independent of the first X-axis adjustment unit 67 in the direction of the X-axis 16, but rather dependent on it. The first X-axis adjustment unit 67 can be actively adjustable along the X-axis 16.

[0123] Furthermore, it can be provided that the fourth X-axis adjustment unit 98 is coupled to the third X-axis adjustment unit 97 by means of a second X-axis compensation unit 102. The fourth X-axis adjustment unit 98 can thus be displaceable relative to the third X-axis adjustment unit 97. The third X-axis adjustment unit 97 can be actively adjustable in the direction of the X-axis 16.

[0124] In another embodiment, not shown, it is also conceivable that only the first X-axis adjustment unit 67 is provided and that all work spindles 7, 8, 9, 10 are arranged on the first X-axis adjustment unit 67 and are therefore only adjustable together along the X-axis 16. The distance between the individual work spindles 7, 8, 9, 10 can be the same as the distance between the individual workpiece tables 34, 38, 42, 46.

[0125] In another embodiment, not shown, it can also be provided that the swivel bridge 20 is not displaceable along the Y-axis 17 by means of the Y-axis adjustment unit 87, but rather that the working spindles 7, 8, 9, 10 are displaceable along the Y-axis 17 by means of a Y-axis spindle adjustment unit. Mutatis mutandis to the X-axis adjustment unit 67, the working spindles 7, 8, 9, 10 can be displaced individually, in pairs, or all together.

[0126] Figure 12 shows a fourth, and optionally independent, embodiment of the axis assembly of machine tool 1 in a schematic side view, where again the same reference numerals and component designations are used for identical parts as in the preceding Figures 1 to 11. To avoid unnecessary repetition, reference is made to the detailed description in the preceding Figures 1 to 11.

[0127] As can be seen in Fig. 12, the swivel bridge 20 can be displaced along a horizontal Z-axis 15 by means of a Z-axis adjustment unit 103. This measure can be implemented in addition to the displaceability of the working spindles 7, 8, 9, 10 along the horizontal Z-axis 15. This allows the possible travel range along the horizontal Z-axis 15 to be increased, especially for large workpieces.

[0128] The exemplary embodiments show possible embodiment variants, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiment variants, but rather various combinations of the individual embodiment variants are also possible and this possibility of variation lies within the skill of the person skilled in this technical field due to the teaching on technical action by the present invention.

[0129] The scope of protection is defined by the claims. However, the description and drawings must be consulted for the interpretation of the claims. Individual features or combinations of features from the different embodiments shown and described can, in themselves, represent independent inventive solutions. The problem underlying these independent inventive solutions can be found in the description.

[0130] All references to value ranges in this description are to be understood as encompassing any and all sub-ranges thereof, e.g., the reference 1 to 10 is to be understood as including all sub-ranges, starting from the lower limit 1 and the upper limit 10, i.e., all sub-ranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g., 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

[0131] Finally, for the sake of clarity, it should be noted that, for a better understanding of the structure, some elements have been shown not to scale and / or enlarged and / or reduced in size.

[0132] Reference sign setup

[0133] Machine tool 32 left swivel bearing first workpiece 33 right swivel bearing second workpiece 34 first workpiece table third workpiece 35 first front workpiece table position fourth workpiece rotation machine frame 36 first rear workpiece table position first work spindle rotation second work spindle 37 first workpiece table swivel third work spindle axis fourth work spindle 38 second workpiece table first spindle axis 39 second front workpiece table position second spindle axis rotation third spindle axis 40 second rear workpiece table swivel spindle axis rotation Z-axis 41 second workpiece table swivel

[0134] X-axis axis

[0135] Y-axis 42 third workpiece table

[0136] B processing tool 43 third front workpiece table position workpiece clamping device swivel bridge 44 third rear workpiece table position

[0137] Swivel axis first workpiece holding position 45 third workpiece table swivel axis second workpiece holding position third workpiece holding position 46 fourth workpiece table fourth workpiece holding position 47 fourth front workpiece table bearing

[0138] 48 fourth rear workpiece table position left side panel right side panel 49 fourth workpiece table swivel first connecting part axis second connecting part 50 first intermediate strut second intermediate strut 83 first Z-axis drive unit third intermediate strut 84 second Z-axis drive unit first swivel motor 85 third Z-axis drive unit second swivel motor 86 fourth Z-axis drive unit third swivel motor 87 Y-axis adjustment unit fourth swivel motor 88 first mount first bracket 89 second mount second bracket 90 first mount guide slide third bracket 91 first Y-axis guide rail fourth bracket 92 second mount guide slide first bracket spacing second bracket spacing 93 second Y-axis guide rail third bracket spacing fourth bracket spacing 94 first Y-axis drive motor first rotation angle limiter 95 second Y-axis drive motor second rotation angle limiter 96 swivel motor first X-axis Adjustment unit 97 thirdX-axis adjustment unit, second X-axis adjustment unit, 98 fourth X-axis adjustment unit, first X-axis guide rail, 99 third guide carriage, second X-axis guide rail, 100 fourth guide carriage rail, 101 first X-axis compensation unit, first guide carriage, second guide carriage, 102 second X-axis compensation unit, first X-axis drive unit, second X-axis drive unit, 103 Z-axis adjustment unit, first Z-axis adjustment unit, 104 connecting part, second Z-axis adjustment unit, third Z-axis adjustment unit, fourth Z-axis adjustment unit, first Z-axis guide, second Z-axis guide, third Z-axis guide, fourth Z-axis guide

Claims

Patent claims 1. Machine tool (1) comprising: - a machine frame (6); - a first working spindle (7) which is rotatably mounted about a first spindle axis (11); - a second working spindle (8) which is rotatably mounted about a second spindle axis (12); - a workpiece clamping device (19) with a first workpiece holding position (22) designed to hold at least one first workpiece (2) and a second workpiece holding position (23) designed to hold a second workpiece (3), wherein the first working spindle (7) is assigned to the first workpiece holding position (22) and the second working spindle (8) is assigned to the second workpiece holding position (23), wherein the workpiece clamping device (19) comprises a pivoting bridge (20) which is pivotably mounted about a pivot axis (21), characterized in that the pivoting bridge (20) is designed as a frame construction with a left side part (28), a right side part (29), a first connecting part (30) and a second connecting part (31), wherein the left side part (28) and the right side part (29) are coupled to each other by means of the first connecting part (30) and by means of the second connecting part (31),wherein a left pivot bearing (32) is formed which is coupled to the left side part (28) and a right pivot bearing (33) is formed which is coupled to the right side part (29), wherein the pivot bridge (20) is pivotably mounted on the machine frame (6) about the pivot axis (21) by means of the left pivot bearing (32) and the right pivot bearing (33), wherein the first workpiece holding position (22) is arranged on a first workpiece table (34), wherein the first workpiece table (34) is pivotably mounted on the pivot bridge (20) about a first workpiece table pivot axis (37) by means of a first front workpiece table bearing (35) and a first rear workpiece table bearing (36), and wherein the second workpiece holding position (23) is arranged on a second workpiece table (38), wherein the second workpiece table (38) is pivotally mounted on the pivot bridge (20) by means of a second front, The workpiece table support (39) and a second rear workpiece table support (40) are pivotably mounted on the swivel bridge (20) about a second workpiece table swivel axis (41).

2. Machine tool (1) according to claim 1, characterized in that the first spindle axis (11) is arranged parallel to a horizontal Z-axis (15) and the second spindle axis (12) is arranged parallel to the horizontal Z-axis (15).

3. Machine tool (1) according to claim 1 or 2, characterized in that the first working spindle (7) and the second working spindle (8) are arranged next to each other spaced apart in a horizontal X-axis (16) and that the first workpiece holding position (22) and the second workpiece holding position (23) are arranged next to each other spaced apart in the horizontal X-axis (16) and that the swivel axis (21) is aligned parallel to the horizontal X-axis (16).

4. Machine tool (1) according to one of the preceding claims, characterized in that a third working spindle (9) is formed which is rotatably mounted about a third spindle axis (13) and a fourth working spindle (10) is formed which is rotatably mounted about a fourth spindle axis (14) and that the workpiece clamping device (19) comprises a third workpiece holding position (24) which is designed to hold at least one third workpiece (4) and a fourth workpiece holding position (25) which is designed to hold a fourth workpiece (5), wherein the third working spindle (9) is assigned to the third workpiece holding position (24) and the fourth working spindle (10) is assigned to the fourth workpiece holding position (25), wherein the third workpiece holding position (24) is arranged on a third workpiece table (42),wherein the third workpiece table (42) is pivotably mounted on the swivel bridge (20) about a third workpiece table pivot axis (45) by means of a third front workpiece table bearing (43) and a third rear workpiece table bearing (44), and wherein the fourth workpiece holding position (25) is arranged on a fourth workpiece table (46), wherein the fourth workpiece table (46) is mounted by means of a fourth front workpiece table bearing, (47) and a fourth rear workpiece table bearing (48) pivotable about a fourth workpiece table swivel axis (49) on the swivel bridge (20).

5. Machine tool (1) according to claim 4, characterized in that a first intermediate strut (50) is formed between the first workpiece table pivot axis (37) and the second workpiece table pivot axis (41), wherein the first intermediate strut (50) is arranged parallel to the left side part (28), wherein the first intermediate strut (50) is coupled to the first connecting part (30) and the second connecting part (31), and that a second intermediate strut (51) is formed between the second workpiece table pivot axis (41) and the third workpiece table pivot axis (45), wherein the second intermediate strut (51) is arranged parallel to the left side part (28), wherein the second intermediate strut (51) is coupled to the first connecting part (30) and the second connecting part (31), and that a third intermediate strut (52) is formed between the third workpiece table pivot axis (45) and the fourth workpiece table pivot axis (49).wherein the third intermediate strut (52) is arranged parallel to the left side part (28), wherein the third intermediate strut (52) is coupled steeply to the first connecting part (30) and the second connecting part (31).

6. Machine tool (1) according to claim 5, characterized in that a first bracket (57) is arranged on the first intermediate strut (50), on which the first rear workpiece table support (36) is received, wherein the first bracket (57) is arranged at a first bracket distance (61) from the second connecting part (31), and that a second bracket (58) is arranged on the second intermediate strut (51), on which the second rear workpiece table support (40) is received, wherein the second rear workpiece table support (40) is arranged at a second bracket distance (62) from the second connecting part (31), and that a third bracket (59) is arranged on the third intermediate strut (52), on which the third rear workpiece table support (44) is received, wherein the third bracket (59) is arranged at a third bracket distance (63) from the second connecting part (31), and that a fourth bracket (60) is arranged on the left side part (28).at which the fourth, rear workpiece table support (48) is mounted, wherein the fourth support (60) is arranged at a fourth support distance (64) from the second connecting part (31).

7. Machine tool (1) according to claim 4, characterized in that the first rear workpiece table bearing (36), the second rear workpiece table bearing (40), the third rear workpiece table bearing (44) and the fourth rear workpiece table bearing (48) are arranged on the second connecting part (31).

8. Machine tool (1) according to one of the preceding claims, characterized in that a first swivel motor (53) is provided by means of which the first workpiece table (34) can be swivelled about the first workpiece table swivel axis (37) and that a second swivel motor (54) is provided by means of which the second workpiece table (38) can be swivelled about the second workpiece table swivel axis (41).

9. Machine tool (1) according to claim 8, characterized in that a third swivel motor (55) is provided by means of which the third workpiece table (42) can be swivelled about the third workpiece table swivel axis (45) and that a fourth swivel motor (56) is provided by means of which the fourth workpiece table (46) can be swivelled about the fourth workpiece table swivel axis (49).

10. Machine tool (1) according to claim 9, characterized in that the first swivel motor (53), the second swivel motor (54), the third swivel motor (55) and the fourth swivel motor (56) are each designed as hydraulic motors, wherein the swivel motors (53, 54, 55, 56) are coupled with a common supply line and are connected in parallel to each other, wherein the workpiece tables (34, 38, 42, 46) are each pivotable between a first rotation angle limit (65) and a second rotation angle limit (66).

11. Machine tool (1) according to claim 8 or 9, characterized in that the individual swivel motors (53, 54, 55, 56) are each designed as electric motors, in particular as servo motors, preferably as torque motors, and are swivelable independently of each other.

12. Machine tool (1) according to one of the preceding claims, characterized in that the first work spindle (7) is displaceable along the X-axis (16) by means of a first X-axis adjustment unit (67) and the second work spindle (8) is displaceable along the X-axis (16) by means of a second X-axis adjustment unit (68), wherein the first work spindle (7) and the second work spindle (8) are displaceable independently of each other along the X-axis (16).

13. Machine tool (1) according to one of the preceding claims, characterized in that the first working spindle (7) is displaceable along the Z-axis (15) by means of a first Z-axis adjustment unit (75) and the second working spindle (8) is displaceable along the Z-axis (15) by means of a second Z-axis adjustment unit (76), wherein the first working spindle (7) and the second working spindle (8) are displaceable independently of each other along the Z-axis (15).

14. Machine tool (1) according to one of the preceding claims, characterized in that the swivel bridge (20) is displaceable along a vertical Y-axis (17) by means of a Y-axis adjustment unit (87).

15. Machine tool (1) according to one of the preceding claims, characterized in that the swivel bridge (20) is displaceable along a horizontal Z-axis (15) by means of a Z-axis adjustment unit (103).

16. Method for machining a first workpiece (2) and a second workpiece (3) using a machine tool (1), in particular using a machine tool (1) according to one of the preceding claims, the machine tool (1) comprising: - a machine frame (6); - a first working spindle (7) which is rotatably mounted about a first spindle axis (11); - a second working spindle (8) which is rotatably mounted about a second spindle axis (12); - a workpiece clamping device (19) with a first workpiece holding position (22) which is designed to hold at least one first workpiece (2) and a second workpiece holding position (23) which is designed to hold a second workpiece (3) is designed, wherein the first working spindle (7) is assigned to the first workpiece holding position (22) and the second working spindle (8) is assigned to the second workpiece holding position (23), wherein the workpiece clamping device (19) comprises a swivel bridge (20) which is pivotably mounted about a pivot axis (21), wherein the swivel bridge (20) is designed as a frame construction with a left side part (28), a right side part (29), a first connecting part (30) and a second connecting part (31), wherein the left side part (28) and the right side part (29) are coupled to each other by means of the first connecting part (30) and by means of the second connecting part (31), wherein a left pivot bearing (32) is formed which is coupled to the left side part (28) and a right pivot bearing (33) is formed which is coupled to the right side part (29),wherein the swivel bridge (20) is pivotably mounted on the machine frame (6) about the pivot axis (21) by means of the left pivot bearing (32) and the right pivot bearing (33), wherein the first workpiece holding position (22) is arranged on a first workpiece table (34), wherein the first workpiece table (34) is pivotably mounted on the swivel bridge (20) about a first workpiece table pivot axis (37) by means of a first front workpiece table bearing (35) and a first rear workpiece table bearing (36), and wherein the second workpiece holding position (23) is arranged on a second workpiece table (38), wherein the second workpiece table (38) is pivotably mounted on the swivel bridge (20) about a second workpiece table pivot axis (41) by means of a second front workpiece table bearing (39) and a second rear workpiece table bearing (40), characterized in that the method comprises the following method steps: - Machining the first workpiece (2) held in the first workpiece holding position (22) using the first work spindle (7); - Machining the second workpiece (3) held in the second workpiece holding position (23) using the second working spindle (8).

17. Method according to claim 16, characterized in that the first workpiece (2) and the second workpiece (3) each comprise a cylinder head, a crankcase, a camshaft carrier, a camshaft bearing housing, or a camshaft bearing frame of a internal combustion engine and that the first workpiece (2) is clamped at the first workpiece holding position (22) and the second workpiece (3) is clamped at the second workpiece holding position (23) such that the pivot axis (21) extends transversely to the longitudinal extent of the cylinder head, the crankcase, the camshaft carrier, the camshaft bearing housing, or the camshaft bearing frame, wherein in a first pivot position of the swivel bridge (20) about the pivot axis (21) a top or a bottom or a first broad side or a second broad side, in particular a valve seat or an inlet channel of the cylinder head, the crankcase, the camshaft carrier, the camshaft bearing housing, or the camshaft bearing frame is machined and in a second pivot position of the swivel bridge (20) about the pivot axis (21) a first end face or a second end face, in particular oil channels or a camshaft seat of the cylinder head, the crankcase, the camshaft carrier,of the camshaft bearing housing, or of the camshaft bearing frame, is machined.

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