Machine tool and method for operating the machine tool

Abstract

The invention relates to a machine tool (1) having: a machine frame (2) in which a loading space (45) and a machining space (44) are formed; a first working spindle (5) which is mounted for rotation about a first spindle axis (7), said first working spindle (5) being accommodated on the machine frame (2) so as to be displaceable along a horizontal Z axis (9), along a horizontal X axis (10) and along a vertical Y axis (11); and a workpiece clamping device (18) which is designed to receive at least a first workpiece (25) and a second workpiece (31). Furthermore, a second working spindle (6) is provided which is mounted for rotation about a second spindle axis (8). The first working spindle (5) and the second working spindle (6) are arranged vertically one above the other, wherein the first working spindle (5) is designed to machine the first workpiece (25), and the second working spindle (6) is designed to machine the second workpiece (31).

Description

[0001] MACHINE TOOL AND A METHOD FOR OPERATING THE MACHINE TOOL

[0002] The invention relates to a machine tool and a method for operating the machine tool.

[0003] EP3659744A1 discloses a machine tool for machining workpieces, comprising a workpiece table which is mounted in a machine frame so as to be rotatable about a horizontal axis of rotation and which has a workpiece carrier on each of its two opposite table sides for receiving at least one workpiece, wherein one workpiece carrier is provided on a machining side and the other workpiece carrier is provided on a loading side, and wherein the machining-side workpiece carrier and the loading-side workpiece carrier are interchangeable by pivoting the workpiece table.Furthermore, it is provided that the two workpiece carriers each have a protruding support edge for setting up, in particular, plate-shaped workpieces and that the workpiece table is inclined relative to the vertical in its processing and loading position, so that the workpiece placed on the support edge on the loading side can lean against the loading side of the table.

[0004] The machine tool disclosed in EP3659744A1 has the disadvantage that it has low flexibility and also low efficiency.

[0005] The object of the present invention was to overcome the disadvantages of the prior art and to provide an improved machine tool and an improved method for operating the machine tool.

[0006] This object is achieved by a device and a method according to the claims.

[0007] The invention relates to a machine tool comprising: a machine frame in which a loading space and a machining space are formed; a first work spindle which is rotatably mounted about a first spindle axis, wherein the first work spindle is slidably mounted on the machine frame along a horizontal Z-axis, along a horizontal X-axis and along a vertical Y-axis; a workpiece clamping device which is designed to receive at least a first workpiece and a second workpiece.Furthermore, a second work spindle is formed, which is rotatably mounted about a second spindle axis, wherein the second work spindle is slidably mounted on the machine frame along the Z-axis, along the X-axis and along the Y-axis, wherein the first work spindle and the second work spindle are arranged vertically one above the other and the first work spindle is designed to machine the first workpiece and the second work spindle is designed to machine the second workpiece.

[0008] The X-axis and the Z-axis can be arranged in a horizontal plane and aligned orthogonally to each other. The Y-axis can be aligned orthogonally to the X-axis and the Z-axis and arranged vertically. In particular, the Z-axis can be aligned parallel to the spindle axes or parallel to the non-pivoting spindle axes, provided the working spindles are designed to pivot about the Y-axis.

[0009] The machine tool according to the invention offers the advantage that workpieces can be machined easily and with high efficiency. Furthermore, the machine tool according to the invention offers a high degree of flexibility for machining complex workpieces.

[0010] Furthermore, it may be advantageous if the first work spindle and the second work spindle are mounted on a common spindle adjustment device and can be moved together along the Z-axis. This offers the advantage that the first work spindle and the second work spindle can be moved using a common drive. This simplifies the design of the machine tool.

[0011] Alternatively, it can be provided that the first work spindle is displaceable in the Z-axis by means of a first spindle adjustment device and that the second work spindle is displaceable in the Z-axis by means of a second spindle adjustment device, wherein the first work spindle and the second work spindle each have their own adjustment drive and can be moved independently of one another in the Z-axis. This has the advantage that the first work spindle and the second work spindle can perform machining operations independent of one another. In particular, two differently designed workpieces can thus be machined simultaneously in the machine tool. Furthermore, this measure can be used to compensate for tolerances in the different workpieces or in the workpiece tables.Furthermore, it may be advantageous if the first work spindle and the second work spindle are mounted on a common Y-adjustment device and can be moved together along the Y-axis. This offers the advantage that the first work spindle and the second work spindle can be moved using a common drive. This simplifies the design of the machine tool.

[0012] Alternatively, it can be provided that the first work spindle is displaceable in the Y-axis by means of a first Y-adjustment device and that the second work spindle is displaceable in the Y-axis by means of a second Y-adjustment device, wherein the first work spindle and the second work spindle each have their own adjustment drive and can be displaced independently of one another in the Y-axis. This has the advantage that the first work spindle and the second work spindle can perform machining operations independent of one another. In particular, two differently designed workpieces can thus be machined simultaneously in the machine tool. Furthermore, this measure can be used to compensate for tolerances in the different workpieces or in the workpiece tables.

[0013] Furthermore, it may be advantageous if the first work spindle and the second work spindle are mounted on a common X-axis adjustment device and can be moved together along the X-axis. This offers the advantage that the first work spindle and the second work spindle can be moved using a common drive. This simplifies the design of the machine tool.

[0014] Alternatively, it can be provided that the first work spindle is displaceable along the X-axis by means of a first X-adjustment device, and that the second work spindle is displaceable along the X-axis by means of a second X-adjustment device, wherein the first work spindle and the second work spindle each have their own adjustment drive and are displaceable along the X-axis independently of one another. This has the advantage that the first work spindle and the second work spindle can perform machining operations independently of one another. In particular, two differently designed workpieces can thus be machined simultaneously in the machine tool.

[0015] The adjustability of the work spindles in the individual axes can be combined as desired. Furthermore, in addition to the first work spindle and the second work spindle, a third work spindle or even additional work spindles can be provided, with the first work spindle, the second work spindle, and the third work spindle arranged vertically one above the other. This has the advantage of further increasing the efficiency of the machine tool.

[0016] Furthermore, it may be expedient if a swivel table is designed, wherein the swivel table has a first front workpiece holder for the direct and immovable reception of the first workpiece on the swivel table and a second front workpiece holder for the direct and immovable reception of the second workpiece on the swivel table and a first rear workpiece holder for the direct and immovable reception of a first rear workpiece on the swivel table and a second rear workpiece holder for the direct and immovable reception of a second rear workpiece on the swivel table, wherein the swivel table is pivotally mounted about a swivel table axis which is aligned parallel to a horizontal X-axis,Depending on the swivel position of the swivel table, the first front workpiece holder and the second front workpiece holder can be swiveled into the machining area, or the first rear workpiece holder and the second rear workpiece holder can be swiveled into the machining area. This has the advantage that this measure can increase the efficiency of the machine tool. At the same time, the design of the machine tool can be kept as simple as possible. In particular, it can be provided that the swivel table can only be swiveled about the swivel table axis and is otherwise not displaceable relative to the machine frame.

[0017] In other words, the swivel table may have a swivel table front side on which the first front workpiece holder and the second front workpiece holder are arranged and a swivel table rear side on which the first rear workpiece holder and the second rear workpiece holder are arranged.

[0018] In other words, depending on the swivel position of the swivel table, the first work spindle can be assigned to the first front workpiece holder and the second work spindle to the second front workpiece holder, or the first work spindle can be assigned to the first rear workpiece holder and the second work spindle to the second rear workpiece holder. This has the advantage of increasing the efficiency of the machine tool.

[0019] Of course, it is also conceivable that in other swivel positions a further assignment of the workpiece holders to the machining area or to the working spindles is possible.

[0020] Furthermore, it can be provided that the first front workpiece holder is arranged at a first front workpiece holder distance from the swivel table axis, and that the second rear workpiece holder is arranged at a second rear workpiece holder distance from the swivel table axis, wherein the first front workpiece holder distance and the second rear workpiece holder distance are of different sizes, and wherein the swivel table has recesses through which a machining tool can be passed. This has the advantage that this measure also allows a side of the workpieces assigned to the swivel table to be machined.

[0021] Alternatively, the workpieces can be machined on their front side in a first clamping setup and on their back side in a second clamping setup. Re-clamping can take place parallel to machining time.

[0022] The swivel table can be swiveled around the swivel table axis using a swivel table drive motor.

[0023] In an alternative embodiment, it can be provided that the workpiece clamping device comprises a first workpiece table and a second workpiece table, wherein the first workpiece table is pivotably mounted about a first pivot axis which is aligned parallel to the X-axis, and the second workpiece table is pivotably mounted about a second pivot axis which is aligned parallel to the X-axis, and the first work spindle is assigned to the first workpiece table and the second work spindle is assigned to the second workpiece table, wherein the first workpiece table has a first front workpiece holder and a first rear workpiece holder, and the second workpiece table has a second front workpiece holder and a second rear workpiece holder, wherein depending on the pivot position of the first workpiece table and the second workpiece table,The first front workpiece holder and the second front workpiece holder can be pivoted into the machining area, or the first rear workpiece holder and the second rear workpiece holder can be pivoted into the machining area. This has the advantage of increasing the efficiency of the machine tool. At the same time, this measure can increase the flexibility of the machine tool.

[0024] In particular, it can be provided that the first workpiece table is pivotable exclusively about the first pivot axis and is otherwise not displaceable relative to the machine frame.

[0025] In particular, it can be provided that the second workpiece table is pivotable exclusively about the second pivot axis and is otherwise not displaceable relative to the machine frame.

[0026] In other words, the first workpiece table can have a first workpiece table front side, on which the first front workpiece holder is arranged. Furthermore, the second workpiece table can have a second workpiece table front side, on which the second front workpiece holder is arranged. Furthermore, the first workpiece table can have a first workpiece table rear side, on which the first rear workpiece holder is arranged. Furthermore, the second workpiece table can have a second workpiece table rear side, on which the second rear workpiece holder is arranged.

[0027] In a first embodiment, the first workpiece table and the second workpiece table may have a common drive unit for rotating the first workpiece table about the first pivot axis and for rotating the second workpiece table about the second pivot axis. The first workpiece table and the second workpiece table may be coupled to each other by means of a gear mechanism. This has the advantage of increasing the efficiency of the machine tool.

[0028] In a second embodiment, the first workpiece table may have a first drive unit for rotating the first workpiece table about the first pivot axis, and the second workpiece table may have a second drive unit for rotating the second workpiece table about the second pivot axis. The first workpiece table and the second workpiece table can be pivoted independently of one another. This has the advantage that this measure can increase the efficiency of the machine tool. At the same time, this measure can increase the flexibility of the machine tool.

[0029] In other words, depending on the swivel position of the first workpiece table, the first work spindle can be assigned to the first front workpiece holder or the first work spindle can be assigned to the first rear workpiece holder. Depending on the swivel position of the second workpiece table, the second work spindle can be assigned to the second front workpiece holder or the second rear workpiece holder. This has the advantage of increasing the efficiency of the machine tool. Furthermore, this measure allows the space requirements or installation space of the machine tool to be kept as small as possible.

[0030] Of course, it is also conceivable that in other swivel positions a further assignment of the workpiece holders to the machining area or to the working spindles is possible.

[0031] Also advantageous is a configuration according to which it can be provided that the first front workpiece holder is arranged at a first front workpiece holder distance from the first pivot axis and that the first rear workpiece holder is arranged at a first rear workpiece holder distance from the first pivot axis, wherein the first front workpiece holder distance and the first rear workpiece holder distance extend into different sides of the first workpiece table with respect to the first pivot axis and wherein the pivot table has recesses through which a machining tool can be passed. This has the advantage that this measure also allows a side of the workpieces assigned to the workpiece table to be machined.

[0032] According to a further development, it is possible for the first workpiece table to have a first radius which is adapted to a first flight circle of the first workpiece table, and for the second workpiece table to have a second radius which is adapted to a second flight circle of the second workpiece table, wherein the first flight circle of the first workpiece table and the second flight circle of the second workpiece table are arranged at a flight circle distance of between 0.1 mm and 10 mm, in particular between 0.2 mm and 5 mm, preferably between 0.5 mm and 2 mm, from one another. This has the advantage that the smallest possible gap can be created between the first workpiece table and the second workpiece table, so that the best possible separation can be created between the loading space and the processing space.

[0033] Furthermore, it can be provided that the first workpiece table has a first sealing element, in particular at the first radius, and the second workpiece table has a second sealing element, in particular at the second radius. This has the advantage that this measure can improve the seal between the first workpiece table and the second workpiece table.

[0034] In particular, it can be provided that the first radius extends over a certain area of ​​the first workpiece table or that the first workpiece table has a certain thickness, so that the sealing function can be maintained even with a slight pivoting of the first workpiece table.

[0035] Furthermore, it can be provided that the second radius extends over a certain area of ​​the second workpiece table or that the second workpiece table has a certain thickness, so that the sealing function can be maintained even with a slight pivoting of the second workpiece table.

[0036] Furthermore, a rubber profile can be arranged on the first radius and / or the second radius. This measure can further increase the sealing effect.

[0037] Furthermore, it can be provided that a sealing element, such as a rubber profile or a brush, is arranged on the first radius and / or on the second radius, which is displaceable in the radial direction in order to be able to adjust and / or actively close the gap.

[0038] In an alternative embodiment, it can be provided that the first workpiece table has a first flight circle of the first workpiece table and the second workpiece table has a second flight circle of the second workpiece table, wherein the first flight circle of the first workpiece table and the second flight circle of the second workpiece table are arranged at a flight circle distance from one another, wherein a partition wall segment is arranged between the first workpiece table and the second workpiece table, wherein the partition wall segment has a shape adapted to the first flight circle and the second flight circle. This has the advantage that this measure can create the best possible separation between the loading area and the processing area. Furthermore, this measure can be used to vary the distance between the two workpiece tables without having to change the size of the two workpiece tables.

[0039] In particular, it can be provided that the separation has a shape that is negative to the first radius or the second radius and has a certain thickness, so that the sealing function can be maintained even with a slight pivoting of the first workpiece table or the second workpiece table.

[0040] Furthermore, it can be provided that a first tool magazine is arranged laterally to the workpiece clamping device or at a longitudinal end of the workpiece clamping device, which first tool magazine is designed to accommodate a plurality of machining tools, wherein the first work spindle can be displaced towards the first tool magazine so that the machining tools can be received directly from the first tool magazine into the first work spindle, and that a second tool magazine is arranged laterally to the workpiece clamping device, which second tool magazine is designed to accommodate a plurality of machining tools, wherein the second work spindle can be displaced towards the second tool magazine so that the machining tools can be received directly from the second tool magazine into the second work spindle.

[0041] Furthermore, it can be provided that a first tool turret is arranged laterally to the workpiece clamping device or at a longitudinal end of the workpiece clamping device, which is designed to accommodate a plurality of machining tools, wherein the first work spindle can be moved relative to the first tool turret so that the machining tools can be received directly from the first tool turret into the first work spindle, and that a second tool turret is arranged laterally to the workpiece clamping device, which is designed to accommodate a plurality of machining tools, wherein the second work spindle can be moved relative to the second tool turret so that the machining tools can be received directly from the second tool turret into the second work spindle. This has the advantage that this measure makes tool changing as simple as possible.

[0042] Laterally in the sense of this document means arranged next to the workpiece clamping device with respect to the X-axis. Laterally can mean directly adjacent to the workpiece clamping device or at a distance from the workpiece clamping device.

[0043] In particular, it can be provided that the tool turrets can rotate the machining tools into a change position in which the machining tools can be removed from the respective work spindle or machining tools that have just been used can be inserted into the tool turret.

[0044] In particular, it is conceivable for the work spindles to be able to move to multiple positions of the respective tool turret, so that the currently used machining tool can be deposited and the new machining tool can be removed without rotating the tool turret. In particular, it can be provided that the first tool turret is positioned such that two tool holding positions of the first tool turret are arranged vertically one above the other, so that the old tool of the first work spindle can be deposited and a new tool of the first work spindle can be picked up without rotating the first tool turret and without shifting the first work spindle in the X-axis.Furthermore, the second tool turret can be positioned so that two tool holding positions of the second tool turret are arranged vertically one above the other, allowing the old tool of the second work spindle to be removed and a new tool to be picked up without rotating the second tool turret and without shifting the second work spindle in the X-axis. This has the advantage of simplifying tool changing.

[0045] Furthermore, it can be provided that two tool turrets are also arranged on a second side of the workpiece clamping device or at a second longitudinal end of the workpiece clamping device, which have a similar structure to the first tool turret and second tool turret already described. This has the advantage that this measure can expand the storage capacity for storing the tools. Furthermore, this measure can ensure that the currently closest tool turret can be approached for tool changes, thereby reducing tool change times.

[0046] Furthermore, it can be provided that the first tool turret is mounted so as to be rotatable about a first turret axis and that the first tool turret has a plurality of first tool holding positions in a circular pattern, and that the second tool turret is mounted so as to be rotatable about a second turret axis and that the second tool turret has a plurality of second tool holding positions in a circular pattern. This has the advantage that the tools can be changed easily.

[0047] Of course, it is also conceivable that between the placement of the currently used machining tool and the removal of the new one, both the respective machining spindle is moved and the respective tool turret is rotated. The individual tool holding positions can be arranged in a circular pattern on the tool turret.

[0048] Furthermore, it can be provided that two tool turrets are also arranged on a second side of the workpiece clamping device or on a second longitudinal end of the workpiece clamping device, which tool turrets have a similar structure to the first tool turret and second tool turret already described.

[0049] In an alternative, it can be provided that a tool magazine is arranged at a longitudinal end of the workpiece clamping device, wherein the tool magazine comprises a chain-type magazine, wherein a straight run of the chain-type magazine is vertically aligned, wherein the first work spindle and the second work spindle are displaceable relative to the straight run of the chain-type magazine, wherein a distance between the first work spindle and the second work spindle corresponds to a pitch or a multiple of the pitch of the chain-type magazine. It is advantageous here that the first work spindle and the second work spindle can be moved relative to the chain-type magazine in order to deposit the no longer required work tool and to accommodate a new machining tool.Because the distance between the first work spindle and the second work spindle corresponds to a pitch or a multiple of a pitch of the chain circulating magazine, the machining tools held in the first work spindle and second work spindle can be deposited at the same time or new machining tools can be picked up at the same time in a wider step.

[0050] Furthermore, it may be advantageous for the first work spindle and the second work spindle to be movable independently of each other along the horizontal Z-axis and the vertical Y-axis. This offers the advantage that the workpieces can be machined efficiently even when the work tables are tilted. This also offers the advantage that the first and second workpieces can have different shapes.

[0051] Furthermore, it can be provided that a first swivel head is formed, by means of which the first work spindle can be pivoted about the vertical Y-axis, and that a second swivel head is formed, by means of which the second work spindle can be pivoted about the vertical Y-axis. In particular, it can be provided that the first work spindle can be pivoted exclusively about the vertical Y-axis and cannot otherwise be pivoted about any axis, and that the second work spindle can be pivoted exclusively about the vertical Y-axis and cannot otherwise be pivoted about any axis. This measure can further increase the flexibility of the machine tool while keeping the complexity of the machine tool as low as possible.

[0052] Furthermore, it can be provided that the entire main adjustment unit together with the first work spindle arranged thereon can be pivoted about the vertical Y-axis.

[0053] Furthermore, it can be provided that the first main adjustment unit and the second main adjustment unit can be pivoted separately and independently of each other about the vertical Y-axis.

[0054] According to the invention, a method for operating a machine tool is provided. The method comprises the following steps:

[0055] - machining a first workpiece, which is clamped on a first front workpiece holder of the workpiece clamping device and pivoted into a machining space of the machine tool, by means of a machining tool clamped in the first work spindle and simultaneous loading of a first rear workpiece on a first rear workpiece holder of the workpiece clamping device, wherein the first rear workpiece holder is pivoted into a loading space of the machine tool; - alternately machining the first workpiece and the first rear workpiece by means of the same machining tool clamped in the first work spindle, wherein the first front workpiece holder of the workpiece clamping device or the first rear workpiece holder of the workpiece clamping device is pivoted into the machining space of the machine tool in a pendulum operation.

[0056] The method according to the invention has the advantage that the efficiency of the machine tool can be improved.

[0057] In one embodiment, it is possible for the method to be carried out by means of a machine tool, comprising: a machine frame in which a loading space and a machining space are formed; a first work spindle which is rotatably mounted about a first spindle axis, wherein the first work spindle is slidably received on the machine frame along a horizontal Z-axis, along a horizontal X-axis and along a vertical Y-axis; a workpiece clamping device which is designed to receive a first workpiece and a first rear workpiece.Wherein a swivel table is formed, wherein the swivel table has a first front workpiece holder for the direct and immovable reception of the first workpiece on the swivel table and a first rear workpiece holder for the direct and immovable reception of a first rear workpiece on the swivel table, wherein the swivel table is pivotally mounted about a swivel table axis which is aligned parallel to a horizontal X-axis, wherein, depending on the pivot position of the swivel table, the first front workpiece holder can be pivoted into the machining space or the first rear workpiece holder can be pivoted into the machining space.

[0058] In a further embodiment, it is possible for the method to be carried out by means of a machine tool, comprising: a machine frame in which a loading space and a machining space are formed; a first work spindle which is rotatably mounted about a first spindle axis, wherein the first work spindle is slidably received on the machine frame along a horizontal Z-axis, along a horizontal X-axis and along a vertical Y-axis; a workpiece clamping device which is designed to receive at least a first workpiece and a second workpiece.

[0059] Furthermore, a second work spindle is formed, which is rotatably mounted about a second spindle axis, wherein the second work spindle is slidably mounted on the machine frame along the Z-axis, along the X-axis and along the Y-axis, wherein the first work spindle and the second work spindle are arranged vertically one above the other and the first work spindle is designed for machining the first workpiece and the second work spindle is designed for machining the second workpiece. Wherein a swivel table is designed,wherein the swivel table has a first front workpiece holder for directly and immovably receiving the first workpiece on the swivel table and a second front workpiece holder for directly and immovably receiving the second workpiece on the swivel table and a first rear workpiece holder for directly and immovably receiving a first rear workpiece on the swivel table and a second rear workpiece holder for directly and immovably receiving a second rear workpiece on the swivel table, wherein the swivel table is pivotally mounted about a swivel table axis which is aligned parallel to a horizontal X-axis,Depending on the swivel position of the swivel table, the first front workpiece holder and the second front workpiece holder can be swiveled into the machining area, or the first rear workpiece holder and the second rear workpiece holder can be swiveled into the machining area. In this case, the method can additionally comprise the following steps:

[0060] - machining a second workpiece, which is clamped on a second front workpiece holder of the workpiece clamping device and is pivoted into a machining space of the machine tool, by means of a machining tool clamped in the second work spindle and simultaneously loading a second rear workpiece on a second rear workpiece holder of the workpiece clamping device, wherein the second rear workpiece holder is pivoted into a loading space of the machine tool;

[0061] - alternating machining of the second workpiece and the second rear workpiece by means of the same machining tool clamped in the second work spindle, wherein the second front workpiece holder of the workpiece clamping device or the second rear workpiece holder of the workpiece clamping device is pivoted into the machining space of the machine tool in a pendulum operation. Also advantageous is a variant according to which it can be provided that the loading of the first rear workpiece at the first rear workpiece holder of the workpiece clamping device takes place in a time window in which the machining of the first workpiece does not require pivoting of the first front workpiece holder, wherein outside of this time window during the machining of the first workpiece the first workpiece table is pivoted about a first pivot axis or the pivot table is pivoted about the pivot table axis.This measure makes it possible for the first workpiece to be swiveled for more flexible processing and for a corresponding time window to be used for changing the first rear workpiece.

[0062] In particular, it can be provided that the loading of the first rear workpiece into the first rear workpiece holder of the workpiece clamping device takes place during a time window in which the machining tool is not currently engaged with the workpiece. This can occur, for example, during a tool change or when the machining tool is repositioned relative to the workpiece in rapid traverse. This has the advantage that any impacts during the workpiece change do not lead to machining errors in the workpiece that is currently being machined.

[0063] In an alternative embodiment, it is also conceivable for the first rear workpiece to be loaded onto the first rear workpiece holder of the workpiece clamping device in parallel with the machining of the first workpiece, wherein during the machining of the first workpiece the first workpiece table is pivoted about a first pivot axis or the pivot table is pivoted about the pivot table axis, wherein a loading device for loading the first rear workpiece onto the first rear workpiece holder pivots the first rear workpiece accordingly in accordance with the pivoting of the first workpiece table about the first pivot axis or of the pivot table about the pivot table axis, in order to enable loading during the pivoting process. This can be necessary in particular for complex workpieces which require continuous pivoting of the workpiece.

[0064] In other words, it can be provided that the loading of the first rear workpiece on the first rear workpiece holder of the workpiece clamping device takes place in a time window in which the first workpiece table is pivoted about a first pivot axis or the pivot table is pivoted about the pivot table axis, wherein a movement of a device for loading the first rear workpiece is synchronized with the movement of the first rear workpiece holder. This has the advantage that a workpiece change can take place even if there is no time window available in which the workpiece table or the pivot table is not pivoted. In particular, it can be provided that the first rear workpiece is placed on the first rear workpiece holder gently so that machining errors are kept as low as possible.In particular, it can be provided that the time window is selected in such a way that the machining carried out in parallel does not constitute a final machining of a surface, so that any machining errors caused by vibrations when loading the first rear workpiece are removed again in a later machining step.

[0065] According to a further development, it is possible for the program sequence for machining the first workpiece and the first rear workpiece to be analyzed using a digital computer, with the time window for loading the first rear workpiece being automatically determined by the digital computer. This has the advantage that the time window does not have to be determined by the programmer or machine operator. In particular, it can be provided that the digital computer performs an evaluation of the program sequence. The digital computer can have an optimization algorithm stored with which the time window for loading the first rear workpiece is calculated.

[0066] Furthermore, it can be expedient if, in one work step, the swivel table, with the first front workpiece holder and the first workpiece held thereon, and the second front workpiece holder and the second workpiece held thereon, as well as with the first rear workpiece holder and the first rear workpiece held thereon, and the second rear workpiece holder and the second rear workpiece held thereon, is tilted about the swivel table axis at an angle of between 45° and 135°, in particular by 90° to a vertical position, wherein simultaneously the first workpiece is machined by means of the second work spindle and the second rear workpiece is machined by means of the first work spindle. This has the advantage that this measure enables machining of a lateral surface of the first workpiece or of the second rear workpiece with regard to the workpiece clamping.Furthermore, it can be provided that in one work step the swivel table, with the first front workpiece holder and the first workpiece held thereon and the second front workpiece holder and the second workpiece held thereon, is tilted about the swivel table axis at an angle of between 0.5° and 70° to a vertical position, wherein the first workpiece is machined simultaneously by means of the first work spindle and the second workpiece is machined by means of the second work spindle, wherein the first work spindle and the second work spindle are positioned in different positions along the horizontal Z-axis so that the pivoting of the swivel table is compensated. This can be necessary in order to be able to machine both workpieces simultaneously when the swivel table is tilted.

[0067] Furthermore, it may be advantageous if the first workpiece held in the first front workpiece holder and the second workpiece held in the second front workpiece holder are mirror-symmetrical, with the first work spindle and the second work spindle being adjusted in the vertical Y-axis in a mirror-symmetrical manner. This allows, for example, left and right components for vehicles to be easily manufactured.

[0068] Furthermore, it can be provided that, during machining of the first workpiece, the first work spindle is pivoted about the vertical Y-axis by means of a first pivoting head. This has the advantage of further increasing the flexibility during machining of the first workpiece.

[0069] Furthermore, it can be provided that two different machining tools are clamped in the first work spindle and in the second work spindle, whereby both the first workpiece and the second workpiece are machined by means of the machining tool clamped in the first work spindle and both the first workpiece and the second workpiece are machined by means of the machining tool clamped in the second work spindle. This has the advantage that this measure can increase the efficiency of the machine tool, since the non-productive times for changing the machining tools can be eliminated. In this case, it can be provided that the first work spindle and the second work spindle carry out machining on the first workpiece at the same time and, at a later time, carry out machining on the second workpiece at the same time.Alternatively, it can be provided that the first work spindle performs machining on the first workpiece, while the second work spindle simultaneously performs machining on the second workpiece. At a later point in time, the second work spindle performs machining on the first workpiece, while the first work spindle simultaneously performs machining on the second workpiece. Of course, this requires that the work spindles can be moved along the Y-axis to perform such machining.

[0070] This measure is particularly useful when the machining steps with the different machining tools take approximately the same amount of time. This could be, for example, drilling a hole using a drilling tool clamped in the first work spindle and cutting a thread or countersinking using a thread cutter or countersinking tool clamped in the second work spindle.

[0071] A machining tool within the meaning of this document can, for example, be a cutting tool. A machining tool within the meaning of this document can also be, for example, a friction stir welding tool. In the broadest sense, a measuring or testing device mounted in the work spindle can also be considered a machining tool.

[0072] The machining area, as defined in this document, is the area within the machine tool where machining takes place. In particular, the machining area may be enclosed in an enclosure to minimize all emissions from the machining area.

[0073] The loading area within the meaning of this document is located on the side of the workpiece clamping device facing away from the machining area.

[0074] The loading area can also be enclosed by a housing. In particular, it can be provided that the machining area and the loading area are enclosed by a common housing, with the loading area being separated from the machining area by the workpiece clamping device. This type of concept is particularly applicable to fully automated machine tools, in which a handling device for clamping the workpieces is provided on the workpiece clamping device. In an alternative design variant, it is also conceivable for the loading area to have no housing but to be freely accessible. In such machine tools, the workpiece clamping device forms part of the housing of the machining area.

[0075] Furthermore, it can be provided that the workpiece clamping device or parts thereof, such as the first workpiece table and / or the second workpiece table and / or the swivel table, are displaceable in the Z-axis relative to the machine frame. This has the advantage that this measure can increase the working range of the work spindles in the Z-axis. In particular, it can be provided that the first workpiece table and / or the second workpiece table and / or the swivel table are displaceably mounted on the machine frame by means of linear guides.

[0076] Furthermore, it can be provided that the first workpiece table and the second workpiece table are mounted individually and independently of each other on the machine frame. This has the advantage of increasing the flexibility of the machine tool.

[0077] Furthermore, it can be provided that the first work spindle and the second work spindle are operated at different speeds. This has the advantage of reducing vibrations in the machine tool. In particular, it can be provided that the speeds are selected such that the excitation frequencies of the machining process do not lie within the range of the natural frequencies of the machine tool or the workpieces. In particular, this measure can also ensure that the excitation frequencies at the first work spindle and the second work spindle overlap in such a way that the superimposed excitation frequency lies outside the natural frequencies of the machine tool.

[0078] For a better understanding of the invention, it is explained in more detail using the following figures.

[0079] They show in a highly simplified, schematic representation:

[0080] Fig. 1 is a perspective view of a first embodiment of a machine tool with a first workpiece table and a second workpiece table; Fig. 2 is a schematic side view of an embodiment of the machine tool with a first workpiece table and a second workpiece table with radii;

[0081] Fig. 3 is a schematic side view of an embodiment of the machine tool with a first workpiece table and a second workpiece table with a partition wall segment;

[0082] Fig. 4 is a perspective view of another embodiment of the machine tool with a swivel table and a tool magazine;

[0083] Fig. 5 is a schematic side view of an embodiment of the machine tool with the swivel table and workpieces arranged offset from one another;

[0084] Fig. 6 is a schematic side view of an embodiment of the machine tool with the swivel table and workpieces arranged one behind the other, wherein the swivel table is swiveled by 90°;

[0085] Fig. 7 is a perspective rear view of another embodiment of the machine tool with two main adjustment units;

[0086] Fig. 8 is a plan view of an embodiment of a first work spindle with a first swivel head;

[0087] Fig. 9 is a plan view of an embodiment of a second work spindle with a second swivel head;

[0088] Fig. 10 is a schematic side view of an embodiment of the machine tool with the swivel table and a work spindle.

[0089] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations. The disclosures contained throughout the description can be applied analogously to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and these positional information must be applied analogously to the new position in the event of a change in position.

[0090] Fig. 1 shows a schematic representation of a machine tool 1 for machining workpieces 25, 31, 28, 34. The machine tool 1 has a machine frame 2, which serves as a base for the components attached to it.

[0091] For the sake of clarity, the machine frame 2 is shown only schematically in Fig. 1. However, it should be noted that the machine frame 2 can be anchored at the installation site. Furthermore, the machine frame 2 can, of course, serve to accommodate all components of the machine tool 1.

[0092] Furthermore, a spindle adjustment device 3 is provided, which is arranged on the machine frame 2 or coupled thereto. The spindle adjustment device 3 can serve to accommodate a first work spindle 5 and a second work spindle 6.

[0093] The spindle adjustment device 3 can have a work head 4, on which a first work spindle 5 and a second work spindle 6 can be mounted. The first work spindle 5 is mounted on the work head 4 so as to be rotatable about a first spindle axis 7, and the second work spindle 6 is mounted on the work head 4 so as to be rotatable about a second spindle axis 8. The two work spindles 5, 6 each serve to hold a machining tool 51 and, for this purpose, have a clamping device for holding the machining tool 51.

[0094] The working spindles 5, 6 are adjustable relative to the machine frame 2 by means of the spindle adjustment device 3 in a Z-axis 9, in an X-axis 10 and in a Y-axis 11 arranged at right angles to the Z-axis 9 and X-axis 10.

[0095] In a further embodiment, it can be provided that the working spindles 5, 6 are mounted on the working head 4 so that they cannot be moved relative to one another, and thus only the working head 4 has to be moved in the Z-axis 9, in the X-axis 10 and in the Y-axis 11 relative to the machine frame 2 in order to move the working spindles 5, 6 synchronously with one another.

[0096] In particular, it can be provided that the Z-axis 9 is arranged horizontally. The first spindle axis 7 and the second spindle axis 8 can be arranged parallel to the Z-axis 9. Furthermore, it can be provided that the X-axis 10 is also arranged horizontally. The X-axis 10 is arranged at a right angle to the Z-axis 9. The spindle adjustment device 3 can have a main adjustment unit 12 which is coupled to the machine frame 2 by means of an X-axis linear guide 13. For simplified illustration, the X-axis linear guide 13 is only shown rudimentarily. In particular, it can be provided that the X-axis linear guide 13 has four or more guide carriages which are coupled to the main adjustment unit 12 and which interact with two guide rails which are coupled to the machine frame 2.

[0097] The main adjustment unit 12 can be moved in the direction of the X-axis 10 relative to the machine frame 2 by means of the X-axis linear guide 13.

[0098] Furthermore, it can be provided that a height adjustment unit 14 is formed, which is coupled to the main adjustment unit 12 by means of a Y-axis linear guide 15. The Y-axis linear guide 15 enables the height adjustment unit 14 to be displaced along the Y-axis 11 relative to the main adjustment unit 12 or relative to the machine frame 2.

[0099] In a first embodiment, the first work spindle 5 is arranged on a first height adjustment unit 14 and the second work spindle 6 is arranged on a second height adjustment unit 14, and can thus be displaced independently of one another along a Y-axis 11. In this embodiment, the first height adjustment unit 14 can have a first drive and the second height adjustment unit 14 can have a second drive. The two height adjustment units 14 can both be mounted on the main adjustment unit 12 by means of a Y-axis linear guide 15.

[0100] In a further embodiment, the first work spindle 5 and the second work spindle 6 can be arranged on a common height adjustment unit 14 and thus be displaceable together along a Y-axis 11. In this embodiment, only a single drive is required for the common height adjustment units 14.

[0101] The Y-axis linear guide 15 can also have a guide rail, which is arranged on the main adjustment unit 12 and which is coupled to one or more guide carriages, which are arranged on the first work spindle 5 or the second work spindle 6. Furthermore, as can be seen from the illustration in Fig. 1, it can be provided that the first work spindle 5 is displaceable in the Z-axis 9 by means of a first Z-axis linear guide 16 and that the second work spindle 6 is displaceable in the Z-axis 9 by means of a second Z-axis linear guide 17, wherein the first work spindle 5 and the second work spindle 6 are displaceable independently of one another. In this case, it can be provided that the first work spindle 5 is displaceable in the Z-axis 9 by means of a first drive and the second work spindle 6 is displaceable in the Z-axis 9 by means of a second drive.

[0102] In addition, the machine tool 1 comprises a workpiece clamping device 18, which serves to hold the workpieces 25, 31, 28, 34 to be machined.

[0103] The workpiece clamping device 18 can have a first workpiece table 19 and a second workpiece table 20. The first workpiece table 19 is pivotable relative to the machine frame 2 with respect to a first pivot axis 21. The second workpiece table 20 is pivotable relative to the machine frame 2 with respect to a second pivot axis 22.

[0104] The two swivel axes 21, 22 of the two workpiece tables 19, 20 are arranged parallel to the X-axis 10.

[0105] In particular, it can be provided that the first workpiece table 19 has a first front workpiece holder 24 for receiving the first workpiece 25 on a first workpiece table front side 23. Furthermore, it can be provided that the first workpiece table 19 has a first rear workpiece holder 27 for receiving a first rear workpiece 28 on a first workpiece table rear side 26.

[0106] Furthermore, it can be provided that the second workpiece table 20 has a second front workpiece holder 30 on a second workpiece table front side 29 for receiving the second workpiece 31. Furthermore, it can be provided that the second workpiece table 20 has a second rear workpiece holder 33 on a second workpiece table rear side 32 for receiving a second rear workpiece 34.

[0107] In particular, it can be provided that the first workpiece 25 and the second workpiece 31 are designed to be identical to one another in their outer contours and that the same machining steps are carried out on the two workpieces 25, 31. Furthermore, it can of course also be provided that the first workpiece 25 and the first rear workpiece 28 are designed to be identical to one another in their outer contours and that the same machining steps are carried out on the two workpieces 25, 28. Furthermore, it can of course also be provided that the second workpiece 31 and the second rear workpiece 34 are designed to be identical to one another in their outer contours and that the same machining steps are carried out on the two workpieces 31, 34.

[0108] For the sake of clarity, the two workpiece tables 19, 20 are only shown rudimentarily in Fig. 1. Naturally, a wide variety of fastening options can be provided for attaching the workpieces 25, 31, 28, 34 to the workpiece tables 19, 20. In particular, it can be provided that rotary tables are formed on each of the two workpiece tables 19, 20, which serve to fasten the workpieces 25, 31 and simultaneously to rotate the workpieces 25, 31, 28, 34 relative to the workpiece tables 19, 20.

[0109] The first workpiece table 19 is rotatably mounted on the machine frame 2 by means of a first pivot bearing 35 and a second pivot bearing 36. Similarly, the second workpiece table 20 is rotatably mounted on the machine frame 2 by means of a first pivot bearing 37 and a second pivot bearing 38. The pivot bearings 35, 36, 37, 38 can, for example, be designed in the form of bearing blocks, which are attached to corresponding receptacles on the workpiece table 19.

[0110] As can be seen from Fig. 1, it can be provided that the first workpiece table 19 has a workpiece clamping area which extends between the first pivot bearing 35 and the second pivot bearing 36. Analogously, it can be provided that the second workpiece table 20 has a workpiece clamping area which extends between the first pivot bearing 37 and the second pivot bearing 38 of the second workpiece table 20.

[0111] The workpiece clamping area of ​​the first workpiece table 19 has a first workpiece clamping length. The workpiece clamping area of ​​the second workpiece table 20 has a second workpiece clamping length. Preferably, the first workpiece table 19 and the second workpiece table 20 are of identical design.

[0112] The two workpiece tables 19, 20 and the two pivot axes 21, 22 are arranged at a distance 39 from each other. The distance 39 also extends in the direction of the Y-axis 11. The described configuration ensures that the first work spindle 5 is assigned to the first workpiece table 19 and that the second work spindle 6 is assigned to the second workpiece table 20.

[0113] In particular, it can be provided that an adjusting device is arranged in the workpiece clamping device 18, by means of which the distance 39 between the two workpiece tables 19, 20 or the two pivot axes 21, 22 can be adjusted.

[0114] By means of the machine tool 1 according to the invention, two workpieces 25, 31 of identical construction can be machined parallel to one another. The first workpiece 25 is clamped to the first workpiece table 19 and the second workpiece 31 to the second workpiece table 20. The tool of the first work spindle 5 machines the first workpiece 25, and the tool of the second work spindle 6 machines the second workpiece 31. Due to the inventive design of the machine tool 1, the machining of the first workpiece 25 and the second workpiece 31 can take place synchronously with one another. Thus, two workpieces 25, 31 can be machined simultaneously using a machine tool 1 with the simplest possible design, thereby improving the utilization of the machine tool 1 and its productivity.

[0115] Furthermore, parallel to the machining of the first workpiece 25, which is clamped on the first workpiece table front side 23, the first rear workpiece 28 can be exchanged on the first workpiece table rear side 26.

[0116] Furthermore, parallel to the machining of the second workpiece 31, which is clamped on the second workpiece table front side 29, the second rear workpiece 34 can be exchanged on the second workpiece table rear side 32.

[0117] Furthermore, it can be provided that the first workpiece table 19 has a first drive unit 40 for pivoting, and the second workpiece table 20 has a second drive unit 41 for pivoting. In such an embodiment, the first workpiece table 19 and the second workpiece table 20 can be pivoted independently of one another.

[0118] The first drive unit 40 and the second drive unit 41 can each be designed as a torque motor, for example. In this case, the rotor of the torque motor can be torque-coupled directly to the workpiece tables 19, 20.

[0119] In an alternative variant, it can be provided that the workpiece tables 19, 20 are pivoted by means of a common drive unit.

[0120] The common drive unit, in particular a torque motor, can be coupled to the two workpiece tables 19, 20, for example, by means of a belt drive. Alternatively, the common drive unit can be coupled to the two workpiece tables 19, 20 by means of a worm gear.

[0121] Furthermore, it can be provided that the two working spindles 5, 6 are driven by a common drive unit. The drive unit can, for example, be formed by a three-phase asynchronous motor controlled by a frequency converter.

[0122] Furthermore, it is also conceivable that the drive unit is designed in the form of a synchronous motor.

[0123] Of course, it is also possible for each of the working spindles 5, 6 to be driven by its own drive unit. In this case, the working spindle 5, 6 can also be the rotor of the drive unit.

[0124] Furthermore, it can be provided that a distance 42 between the first working spindle 5 and the second working spindle 6 is adjustable in the vertical Y-axis 11.

[0125] Furthermore, it can be provided that a digital computer 43 is formed, which can serve to control the machine tool 1.

[0126] As can also be seen from Fig. 1, it can be provided that a machining space 44 is formed in the area of ​​the work spindles 5, 6. The machining space 44 can be enclosed by a housing (not shown) or can be delimited by the first workpiece table 19 and the second workpiece table 20. A loading space 45 can be formed on the side of the first workpiece table 19 and the second workpiece table 20 opposite the machining space 44. A manipulation device for handling the workpieces 25, 31, 28, 34 can be arranged in the loading space 45. Figures 2 and 3 show a schematic representation of further and possibly independent embodiments of the machine tool 1, wherein the same reference numerals or component designations as in the previous Fig. 1 are used for the same parts.To avoid unnecessary repetition, reference is made to the detailed description in the preceding Fig. 1. In particular, it is pointed out that the exemplary embodiment of the machine tools 1 shown in Figs. 2 and 3 can have the same features, or at least partially the same features, as the exemplary embodiment of the machine tool 1 shown in Fig. 1. For better understanding, a highly schematically simplified representation is chosen in Figs. 2 and 3.

[0127] As can be seen from Fig. 2, the first workpiece table 19 can have a first radius 46, which is adapted to a first flight circle 48 of the first workpiece table 19. The first radius 46 can form the end of the first workpiece table 19.

[0128] Furthermore, it can be provided that the second workpiece table 20 has a second radius 47, which is adapted to a second flight circle 49 of the second workpiece table 20. The second radius 47 can form the end of the second workpiece table 20.

[0129] Furthermore, it can be provided that the first flight circle 48 of the first workpiece table 19 and the second flight circle 49 of the second workpiece table 20 are arranged at a flight circle distance 50 of between 0.5 mm and 2 mm from one another in order to achieve the best possible seal between the first workpiece table 19 and the second workpiece table 20. This measure allows the machining space 44 and the loading space 45 to be separated from one another in order to prevent, as far as possible, the escape of chips or cooling medium from the machining space 44 into the loading space 45.

[0130] In Fig. 2, the machining tools 51 accommodated in the working spindles 5, 6 are also clearly visible.

[0131] As further evident from Fig. 2, it can be provided that the first workpiece table 19 has a first sealing element 74 at the first radius 46. The first sealing element 74 is shown only on one side of the first workpiece table 19 to illustrate an embodiment with a first sealing element 74 and an embodiment without a first sealing element 74. However, it can expediently be provided that a first sealing element 74 is arranged on both sides of the first workpiece table 19, or that no first sealing element 74 is arranged.

[0132] Furthermore, it can be provided that the second workpiece table 20 has a second sealing element 75 at the second radius 47. The second sealing element 75 is shown only on one side of the second workpiece table 20 to illustrate an embodiment with a second sealing element 75 and an embodiment without a second sealing element 75. However, it can be expediently provided that a second sealing element 75 is arranged on both sides of the second workpiece table 20, or that no second sealing element 75 is arranged.

[0133] As can be seen in the further embodiment of Fig. 3, the first workpiece table 19 can have a first radius 46, which is adapted to a first flight circle 48 of the first workpiece table 19. The first radius 46 can form the end of the first workpiece table 19.

[0134] The first sealing element 74 and the second sealing element 75 can of course also be provided in the embodiment according to Fig. 3.

[0135] Furthermore, it can be provided that the second workpiece table 20 has a second radius 47, which is adapted to a second flight circle 49 of the second workpiece table 20. The second radius 47 can form the end of the second workpiece table 20.

[0136] Furthermore, it can be provided that a partition wall segment 52 is arranged between the first workpiece table 19 and the second workpiece table 20, wherein the partition wall segment 52 has a shape adapted to the first flight circle 48 and the second flight circle 49. In particular, the partition wall segment 52 can have a first concave shape 53 towards the first workpiece table 19 and a second concave shape 54 towards the second workpiece table 20.

[0137] This allows for the best possible seal to be achieved between the first workpiece table 19 and the second workpiece table 20. This measure allows the machining chamber 44 and the loading chamber 45 to be separated from one another in order to prevent, as far as possible, the escape of chips or coolant from the machining chamber 44 into the loading chamber 45. Of course, in both embodiments of Figures 2 and 3, as can be seen therefrom, the housing of the machine tool 1 can also have a concave shape adapted to the first workpiece table 19 or the second workpiece table 20.

[0138] As can further be seen from Fig. 3, it can be provided that the first front workpiece holder 24 is arranged on the first workpiece table 19 at a first front workpiece holder distance 56 from the first pivot axis 21. Furthermore, it can be provided that the first rear workpiece holder 27 is arranged at a first rear workpiece holder distance 57 from the first pivot axis 21. In this case, it can be provided that the first front workpiece holder distance 56 and the first rear workpiece holder distance 57 extend into different sides of the first workpiece table 19 with respect to the first pivot axis 21. In particular, it can be provided that the first front workpiece holder distance 56 and the first rear workpiece holder distance 57 are the same size, so that the first front workpiece holder 24 and the first rear workpiece holder 27 are arranged symmetrically on the first workpiece table 19.

[0139] Furthermore, it can be provided that the first workpiece table 19 has at least one first recess 55 through which a machining tool 51 can be passed.

[0140] The second workpiece table 20 can, mutatis mutandis, have the above-described form of the off-center arrangement of the workpiece holders or the provision of a recess, although for the sake of simplicity, a detailed description is omitted.

[0141] Of course, the characteristics described above can also be applied to the embodiment according to Fig. 2.

[0142] Figures 4 and 5 show further and possibly independent embodiments of the machine tool 1 in a schematic representation, wherein the same reference numerals or component designations as in the preceding Figures 1 to 3 are used for the same parts. In order to avoid unnecessary repetition, reference is made to the detailed description in the preceding Figures 1 to 3. In particular, it is pointed out that the embodiment of the machine tools 1 shown in Figures 4 and 5 can have the same features or at least partially the same features as the embodiment of the machine tool 1 shown in Fig. 1. For better understanding, a highly schematically simplified representation has been chosen in Figure 5.

[0143] Fig. 4 shows a schematic representation of the machine tool 1 for machining workpieces 25, 31, 28, 34.

[0144] In contrast to the embodiment according to Fig. 1, in the embodiment according to Fig. 4, a single swivel table 59 can be formed. The swivel table 59 can have the first front workpiece holder 24 on a swivel table front side 60 for directly and immovably receiving the first workpiece 25 on the swivel table 59. The swivel table 59 can also have a second front workpiece holder 30 on the swivel table front side 60 for directly and immovably receiving the second workpiece 31 on the swivel table 59.

[0145] Furthermore, the swivel table 59 can have a first rear workpiece holder 27 on a swivel table rear side 61 for directly and immovably receiving a first rear workpiece 28 on the swivel table 59. Furthermore, the swivel table 59 can have a second rear workpiece holder 33 on the swivel table rear side 61 for directly and immovably receiving a second rear workpiece 34 on the swivel table 59.

[0146] Furthermore, it can be provided that the swivel table 59 is pivotally mounted about a swivel table axis 62, which is aligned parallel to the horizontal X-axis (10). Depending on the pivot position of the swivel table 59, the first front workpiece holder 24 and the second front workpiece holder 30 can be pivoted into the machining space 44, or the first rear workpiece holder 27 and the second rear workpiece holder 33 can be pivoted into the machining space 44.

[0147] Such a design offers the advantage that the forces exerted on the swivel table 59 by the first spindle axis 7 and those exerted on the swivel table 59 by the second spindle axis 8 are balanced out by the opposing positioning with respect to the swivel table axis 62, so that the torque of the swivel table 59 about the swivel table axis 62 or the torque required by the drive motor to hold the swivel table 59 in position during machining can be kept as low as possible. As can also be seen from Fig. 4, the machine tool 1 can be provided with a tool magazine 63. The tool magazine 63 can comprise a first tool turret 64 and a second tool turret 65.

[0148] In particular, it can be provided that the first tool turret 64, which is designed to accommodate a plurality of machining tools 51, is arranged laterally to the workpiece clamping device 18. The first work spindle 5 can be displaceable relative to the first tool turret 64, so that the machining tools 51 can be received directly from the first tool turret 64 into the first work spindle 5. The first tool turret 64 can be rotatably mounted about a first turret axis 66. In particular, it can be provided that the first tool turret 64 has a plurality of first tool receiving locations 68 in a circular pattern.

[0149] Furthermore, it can be provided that a second tool turret 65 is arranged laterally to the workpiece clamping device 18, which is designed to accommodate a plurality of machining tools 51. The second work spindle 6 can be displaceable relative to the second tool turret 65, so that the machining tools 51 can be received directly from the second tool turret 65 into the second work spindle 6. The second tool turret 65 can be rotatably mounted about a second turret axis 67. In particular, it can be provided that the second tool turret 65 has a plurality of second tool receiving locations 69 in a circular pattern.

[0150] Of course, it is also conceivable that the first tool turret 64 and the second tool turret 65 are also arranged in a mirrored design on the second side of the workpiece clamping device 18.

[0151] The described tool magazine 63 can of course also be used in all other design variants of the machine tool 1.

[0152] As can be seen from Fig. 5, it can be provided that the first front workpiece holder 24 is arranged at a first front workpiece holder distance 56 from the swivel table axis 62 and that the second rear workpiece holder 33 is arranged at a second rear workpiece holder distance 58 from the swivel table axis 62. The first front workpiece holder distance 56 and the second rear workpiece holder distance 58 can be of different sizes. The swivel table 59 can have recesses 70 through which a machining tool 51 can be passed in order to machine the rear side of the workpiece.

[0153] The angular position of the swivel table 59, as shown in Fig. 5, can be described as a vertical position, with an angle 71 of the swivel being 0°.

[0154] In the embodiment according to Fig. 6, the first front workpiece holder 24 and the second rear workpiece holder 33 are arranged directly opposite each other on the swivel table 59.

[0155] As can be seen from Fig. 6, it can be provided that in one work step the swivel table 59 is tilted about the swivel table axis 62 at an angle 71 of 90° to a vertical position, wherein at the same time the first workpiece 25 is machined by means of the second work spindle 6 and the second rear workpiece 34 is machined by means of the first work spindle 5.

[0156] Figure 7 shows a schematic representation of a further and possibly independent embodiment of the machine tool 1, wherein the same reference numerals or component designations as in the preceding Figures 1 to 6 are used for the same parts. To avoid unnecessary repetition, reference is made to the detailed description in the preceding Figures 1 to 6. In particular, it is pointed out that the spindle adjustment device 3 of the embodiment of the machine tool 1 shown in Figure 7 can also be applied to the remaining described embodiments. Figure 7 shows the machine tool 1 in a perspective view from behind.

[0157] As can be seen from Fig. 7, it can be provided that a first main adjustment unit 12a and a second main adjustment unit 12b are formed, which can each be displaced independently of one another in the direction of the X-axis 10 relative to the machine frame 2. Furthermore, it can also be provided that the first main adjustment unit 12a and the second main adjustment unit 12b are pivotable individually and independently of one another about the Y-axis 11.

[0158] Furthermore, it can be provided that the first work spindle 5 is arranged on a first height adjustment unit 14a and the second work spindle 6 is arranged on a second height adjustment unit 14 and can thus be displaced independently of one another along a Y-axis 11. In this embodiment, the first height adjustment unit 14 can have a first drive and the second height adjustment unit 14 can have a second drive. The first height adjustment unit 14a can be mounted on the first main adjustment unit 12a by means of a first Y-axis linear guide 15a. The second height adjustment unit 14a can be mounted on the second main adjustment unit 12a by means of a second Y-axis linear guide 15a.

[0159] In such an embodiment variant, it can be provided that the working spindles 5, 6 are individually and independently adjustable in the Z-axis 9, in the X-axis 10 and in the Y-axis 11 relative to the machine frame 2 and thus have an individual drive for each of the adjustment directions.

[0160] The structure as described in Fig. 7 enables the first work spindle 5 to be moved to the second front workpiece holder 30 to machine the second workpiece 31 and the second work spindle 6 to be moved to the first front workpiece holder 24 to machine the first workpiece 25.

[0161] In particular, it can be provided that the first height adjustment unit 14a and the second height adjustment unit 14 can be guided close together to such an extent that the first work spindle 5 can be guided exactly above the second work spindle 6. In this case, the first height adjustment unit 14a can be supported on the second height adjustment unit 14 in order to achieve increased stability.

[0162] Figure 8 shows a schematic embodiment of a possible design of the first work spindle 5 in a plan view. This design can be applied to all other embodiments of the machine tool 1.

[0163] As can be seen from Fig. 8, it can be provided that a first pivoting head 72 is formed, by means of which the first work spindle 5 can be pivoted about the vertical Y-axis 11.

[0164] Fig. 9 shows a schematic embodiment of a possible design of the second work spindle 6 in a plan view. This design can be applied to all other embodiments of the machine tool 1. As can be seen from Fig. 9, a second pivoting head 73 can be provided, by means of which the second work spindle 6 can be pivoted about the vertical Y-axis 11.

[0165] As can be seen from Fig. 10, in particular the described method for operating the machine tool 1 can also be applied to a machine tool 1 with a single first work spindle 5. In particular, the method step of alternately machining the first workpiece 25 and the first rear workpiece 28 by means of the same machining tool 51 clamped in the first work spindle 5, wherein the first front workpiece holder 24 of the workpiece clamping device 18 or the first rear workpiece holder 27 of the workpiece clamping device 18 is pivoted into the machining space 44 of the machine tool 1 in a pendulum operation, can be advantageous on such a machine tool 1, since the non-productive times can be shortened by requiring less frequent tool changes.

[0166] The embodiments show possible embodiments, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but rather various combinations of the individual embodiments with each other are also possible and this possibility of variation lies within the skill of the person skilled in the art in this technical field due to the teaching of technical action by means of the objective invention.

[0167] The scope of protection is determined by the claims. However, the description and drawings must be used to interpret the claims. Individual features or combinations of features from the various embodiments shown and described may represent independent inventive solutions. The problem underlying these independent inventive solutions can be derived from the description.

[0168] All information on value ranges in this description is to be understood as including any and all sub-ranges thereof, e.g. the information 1 to 10 is to be understood as including all sub-ranges, starting from the lower limit of 1 and the upper limit of 10, ie 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. For the sake of clarity, it should be pointed out that in order to improve understanding of the structure, some elements have been shown out of scale and / or enlarged and / or reduced.

[0169] Reference symbol list

[0170] Machine tool 30 second front workpiece support

[0171] Machine frame common spindle adjustment 31 second workpiece direction 32 second workpiece table back

[0172] Working head 33 second rear workpiece holder first work spindle second work spindle 34 second rear workpiece first spindle axis 35 first swivel bearing first second spindle axis workpiece table

[0173] Z-axis 36 second swivel bearing first

[0174] X-axis workpiece table

[0175] Y-axis 37 first pivot bearing second

[0176] Main adjustment unit workpiece table

[0177] X-axis linear guide 38 second pivot bearing second

[0178] Height adjustment unit workpiece table

[0179] Y-axis linear guide 39 Distance between workpiece tables first Z-axis linear guide 40 first drive unit second Z-axis linear guide 41 second drive unit workpiece clamping device 42 Distance between first work spindle first workpiece table second work spindle second workpiece table 43 digital computer first swivel axis 44 machining area second swivel axis 45 loading area first workpiece table front 46 first radius first front workpiece holder 47 second radius first workpiece 48 first flight circle first workpiece table rear 49 second flight circle first rear workpiece holder 50 flight circle distance first rear workpiece 51 machining tool second workpiece table front 52 partition wall segment first concave shape second concave shape first recess first front workpiece holder distance first rear workpiece holder distance second rear workpiece holder distance

[0180] Swivel table

[0181] Swivel table front

[0182] Swivel table back

[0183] Swivel table axis

[0184] Tool magazine first tool turret second tool turret first turret axis second turret axis first tool holder location second tool holder location recess

[0185] Angle first swivel head second swivel head first sealing element second sealing element

Claims

P a t e n t a n s p r ü c h e 1. Machine tool (1) comprising: a machine frame (2) in which a loading space (45) and a machining space (44) are formed; a first work spindle (5) which is rotatably mounted about a first spindle axis (7), wherein the first work spindle (5) is slidably mounted on the machine frame (2) along a horizontal Z-axis (9), along a horizontal X-axis (10) and along a vertical Y-axis (11);a workpiece clamping device (18) which is designed to receive at least a first workpiece (25) and a second workpiece (31), characterized in that a second work spindle (6) is designed which is rotatably mounted about a second spindle axis (8), wherein the second work spindle (6) is slidably received on the machine frame (2) along the Z-axis (9), along the X-axis (10) and along the Y-axis (11), wherein the first work spindle (5) and the second work spindle (6) are arranged vertically one above the other and the first work spindle (5) is designed to machine the first workpiece (25) and the second work spindle (6) is designed to machine the second workpiece (31); 2. Machine tool (1) according to claim 1, characterized in that a first tool turret (64) is arranged laterally to the workpiece clamping device (18), which is designed to receive a plurality of machining tools (51), wherein the first work spindle (5) is displaceable towards the first tool turret (64) so ​​that the machining tools (51) can be received directly from the first tool turret (64) into the first work spindle (5), and that a second tool turret (65) is arranged laterally to the workpiece clamping device (18), which is designed to receive a plurality of machining tools (51), wherein the second work spindle (6) is displaceable towards the second tool turret (65) so that the machining tools (51) can be received directly from the second tool turret (65) into the second work spindle (6).

3. Machine tool (1) according to claim 2, characterized in that on a second side of the workpiece clamping device (18) or on a second Two tool turrets are also arranged at the longitudinal end of the workpiece clamping device (18), which have a similar structure to the first tool turret (64) and second tool turret (65) already described.

4. Machine tool (1) according to claim 2 or 3, characterized in that the first tool turret (64) is mounted rotatably about a first turret axis (66) and that the first tool turret (64) has a plurality of first tool receiving locations (68) in a circular pattern and that the second tool turret (65) is mounted rotatably about a second turret axis (67) and that the second tool turret (65) has a plurality of second tool receiving locations (69) in a circular pattern.

5. Machine tool (1) according to one of the preceding claims, characterized in that a swivel table (59) is formed, wherein the swivel table (59) has a first front workpiece holder (24) for directly and immovably receiving the first workpiece (25) on the swivel table (59) and a second front workpiece holder (30) for directly and immovably receiving the second workpiece (31) on the swivel table (59), and a first rear workpiece holder (27) for directly and immovably receiving a first rear workpiece (28) on the swivel table (59) and a second rear workpiece holder (33) for directly and immovably receiving a second rear workpiece (34) on the swivel table (59), wherein the swivel table (59) is pivotally mounted about a swivel table axis (62) which is aligned parallel to a horizontal X-axis (10).wherein, depending on the pivoting position of the pivoting table (59), the first front workpiece holder (24) and the second front workpiece holder (30) can be pivoted into the machining space (44) or the first rear workpiece holder (27) and the second rear workpiece holder (33) can be pivoted into the machining space (44).

6. Machine tool (1) according to claim 5, characterized in that the first front workpiece holder (24) is arranged at a first front workpiece holder distance (56) from the swivel table axis (62) and that the second rear workpiece holder (33) is arranged at a second rear workpiece receiving distance (58) to the swivel table axis (62), wherein the first front workpiece receiving distance (56) and the second rear workpiece receiving distance (58) are of different sizes and wherein the swivel table (59) has recesses (70) through which a machining tool (51) can be guided.

7. Machine tool (1) according to claim 1, characterized in that the workpiece clamping device (18) comprises a first workpiece table (19) and a second workpiece table (20), wherein the first workpiece table (19) is pivotally mounted about a first pivot axis (21) aligned parallel to the X-axis (10), and the second workpiece table (20) is pivotally mounted about a second pivot axis (22) aligned parallel to the X-axis (10), and in that the first work spindle (5) is assigned to the first workpiece table (19) and the second work spindle (6) is assigned to the second workpiece table (20), wherein the first workpiece table (19) has a first front workpiece holder (24) and a first rear workpiece holder (27), and the second workpiece table (20) has a second front workpiece holder (30) and a second rear workpiece holder (33),wherein, depending on the pivoting position of the first workpiece table (19) and the second workpiece table (20), the first front workpiece holder (24) and the second front workpiece holder (30) can be pivoted into the machining space (44) or the first rear workpiece holder (27) and the second rear workpiece holder (33) can be pivoted into the machining space (44).

8. Machine tool (1) according to claim 7, characterized in that the first front workpiece holder (24) is arranged at a first front workpiece holder distance (56) from the first pivot axis (21) and that the first rear workpiece holder (27) is arranged at a first rear workpiece holder distance (57) from the first pivot axis (21), wherein the first front workpiece holder distance (56) and the first rear workpiece holder distance (57) extend into different sides of the first workpiece table (19) with respect to the first pivot axis (21), and wherein the first workpiece table (19) has at least one first recess (55) through which a machining tool (51) can be guided.

9. Machine tool (1) according to claim 7 or 8, characterized in that the first workpiece table (19) has a first radius (46) which is adapted to a first flight circle (48) of the first workpiece table (19) and the second workpiece table (20) has a second radius (47) which is adapted to a second flight circle (49) of the second workpiece table (20), wherein the first flight circle (48) of the first workpiece table (19) and the second flight circle (49) of the second workpiece table (20) are arranged at a flight circle distance (50) between 0.1 mm and 10 mm, in particular between 0.2 mm and 5 mm, preferably between 0.5 mm and 2 mm from one another.

10. Machine tool (1) according to one of claims 7 to 9, characterized in that the first workpiece table (19), in particular at the first radius (46), has a first sealing element (74) and the second workpiece table (20), in particular at the second radius (47), has a second sealing element (75).

11. Machine tool (1) according to claim 7 or 8 or 10, characterized in that the first workpiece table (19) has a first flight circle (48) of the first workpiece table (19) and the second workpiece table (20) has a second flight circle (49) of the second workpiece table (20), wherein the first flight circle (48) of the first workpiece table (19) and the second flight circle (49) of the second workpiece table (20) are arranged at a flight circle distance (50) from one another, wherein a partition wall segment (52) is arranged between the first workpiece table (19) and the second workpiece table (20), wherein the partition wall segment (52) has a shape adapted to the first flight circle (48) and the second flight circle (49).

12. Machine tool (1) according to one of the preceding claims, characterized in that the first work spindle (5) and the second work spindle (6) are displaceable independently of one another in the horizontal Z-axis (9) and in the vertical Y-axis (11).

13. Machine tool (1) according to one of the preceding claims, characterized in that a first pivoting head (72) is formed, by means of which the first work spindle (5) can be pivoted about the vertical Y-axis (11) and that a second Swivel head (73) is formed, by means of which the second work spindle (6) can be swiveled about the vertical Y-axis (11).

14. Method for operating a machine tool (1), in particular a machine tool (1) according to one of the preceding claims, comprising the method steps: - machining a first workpiece (25) which is clamped on a first front workpiece holder (24) of the workpiece clamping device (18) and is pivoted into a machining space (44) of the machine tool (1), by means of a machining tool (51) clamped in the first work spindle (5) and simultaneously loading a first rear workpiece (28) on a first rear workpiece holder (27) of the workpiece clamping device (18), wherein the first rear workpiece holder (27) is pivoted into a loading space (45) of the machine tool (1); - alternately machining the first workpiece (25) and the first rear workpiece (28) by means of the same machining tool (51) clamped in the first work spindle (5), wherein the first front workpiece holder (24) of the workpiece clamping device (18) or the first rear workpiece holder (27) of the workpiece clamping device (18) are pivoted into the machining space (44) of the machine tool (1) in a pendulum operation.

15. The method according to claim 14, characterized in that the loading of the first rear workpiece (28) on the first rear workpiece holder (27) of the workpiece clamping device (18) takes place in a time window in which the machining of the first workpiece (25) does not require pivoting of the first front workpiece holder (24), wherein outside of this time window during the machining of the first workpiece (25) the first workpiece table (19) is pivoted about a first pivot axis (21) or the pivot table (59) is pivoted about the pivot table axis (62).

16. The method according to claim 14, characterized in that the loading of the first rear workpiece (28) on the first rear workpiece holder (27) of the workpiece clamping device (18) takes place in a time window in which the first workpiece table (19) is rotated about a first pivot axis (21) or the pivot table (59) is rotated about the Swivel table axis (62) is pivoted, wherein a movement of a device for loading the first rear workpiece (28) is synchronized with the movement of the first rear workpiece holder (27).

17. The method according to claim 14, characterized in that the program sequence for machining the first workpiece (25) and the first rear workpiece (28) is analyzed by means of a digital computer (43), wherein the time window for loading the first rear workpiece (28) is determined automatically by means of the digital computer (43).

18. The method according to one of claims 14 to 17, characterized in that in one work step the swivel table (59), with the first front workpiece holder (24) and the first workpiece (25) received thereon and the second front workpiece holder (30) and the second workpiece (31) received thereon as well as with the first rear workpiece holder (27) and the first rear workpiece (28) received thereon and the second rear workpiece holder (33) and the second rear workpiece (34) received thereon, is tilted about the swivel table axis (62) at an angle (71) between 45° and 135° to a vertical position, wherein at the same time the first workpiece (25) is machined by means of the second work spindle (6) and the second rear workpiece (34) is machined by means of the first work spindle (5).

19. Method according to one of claims 14 to 18, characterized in that in one work step the swivel table (59), with the first front workpiece holder and the first workpiece (25) received thereon and the second front workpiece holder and the second workpiece (31) received thereon, is tilted about the swivel table axis (62) at an angle (71) between 0.5° and 70° to a vertical position, wherein at the same time the first workpiece (25) is machined by means of the first work spindle (5) and the second workpiece (31) is machined by means of the second work spindle (6), wherein the first work spindle (5) and the second work spindle (6) are in different Positions along the horizontal Z-axis (9) are positioned so that the pivoting of the swivel table (59) is compensated.

20. Method according to one of claims 14 to 19, characterized in that the first workpiece (25) received on the first front workpiece holder (24) and the second workpiece (31) received on the second front workpiece holder (30) are mirror-imaged, wherein an adjustment of the first work spindle (5) and the second work spindle (6) in the vertical Y-axis (11) takes place mirror-imaged.

21. Method according to one of claims 14 to 20, characterized in that during the machining of the first workpiece (25) the first work spindle (5) is pivoted about the vertical Y-axis (11) by means of a first pivoting head (72).

22. Method according to one of claims 14 to 21, characterized in that two different machining tools (51) are clamped in the first work spindle (5) and in the second work spindle (6), wherein both the first workpiece (25) and the second workpiece (31) are machined by means of the machining tool (51) clamped in the first work spindle (5) and both the first workpiece (25) and the second workpiece (31) are machined by means of the machining tool (51) clamped in the second work spindle (6).

23. Method according to one of claims 14 to 22, characterized in that a first tool turret (64) is arranged laterally to the workpiece clamping device (18), which is designed to receive a plurality of machining tools (51), wherein the first work spindle (5) is displaceable relative to the first tool turret (64) so ​​that the machining tools (51) can be received directly from the first tool turret (64) into the first work spindle (5), and in that a second tool turret (65) is arranged laterally to the workpiece clamping device (18), which is designed to receive a plurality of machining tools (51), wherein the second work spindle (6) is displaceable relative to the second tool turret (65) so that the machining tools (51) can be received directly from the second tool turret (65) into the second work spindle (6), wherein the working spindles (5, 6) can move to several positions of the respective tool turret (64, 65), so that the machining tool (51) currently in use can be deposited and the new machining tool (51) can be removed without rotating the tool turret (64, 65).

24. The method according to claim 23, characterized in that the first tool turret (64) is positioned such that two tool receiving locations of the first tool turret (64) are arranged vertically one above the other, so that the old machining tool (51) of the first work spindle (5) is deposited and a new machining tool (51) of the first work spindle (5) is picked up without rotating the first tool turret (64) and without displacing the first work spindle (5) in the X-axis (10), and in that the second tool turret (65) is positioned such that two tool receiving locations of the second tool turret (65) are arranged vertically one above the other, so that the old machining tool (51) of the second work spindle (6) is deposited and a new machining tool (51) is picked up without rotating the second tool turret (65) and without displacing the second work spindle (6) in the X-axis (10).

25. Method according to one of claims 14 to 24, characterized in that the first work spindle (5) and the second work spindle (6) are operated at different speeds.

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