MACHINE BASE FOR USE IN A MACHINING SYSTEM AND MACHINING SYSTEM COMPRISING SUCH A MACHINE BASE

Abstract

A machine base for use in a machining system comprising at least one work piece holder device receiving section having a work piece holder device interface comprising an aligning means adapted for receiving the work piece holder device aligned on a z-axis, at least one first machining unit receiving section provided with a first machining unit interface adapted for receiving a first machining unit comprising a first tool holder interface, at least one second machining unit receiving section provided with a second machining unit interface adapted for receiving a second machining unit comprising a second tool holder interface, the first and second machining unit interfaces being arranged on opposing first and second sides of and at distances from the work piece holder device interface and are movable at least along the x- or y-axis, respectively, and at least one work piece transfer unit receiving section.

Claims

1. Machine base (10) for use in a machining system, the machine base (10) defining an x,y,z-coordinate system (12) and comprising at least one work piece holder device receiving section (14) provided with a work piece holder device interface (16) comprising aligning means (42) adapted for receiving a work piece holder device (18) aligned along a z-axis of the coordinate system (12), at least one first machining unit receiving section (20) provided with a first machining unit interface (22) adapted for receiving a first machining unit (24) comprising a first tool holder interface (77), at least one second machining unit receiving section (26) provided with a second machining unit interface (28) adapted for receiving a second machining unit (30) comprising a second tool holder interface (79), the first machining unit interface (22) being arranged at a first side of and at a distance from the work piece holder device interface (16) and such that the first tool holder interface (77) is movable at least along the x- or y-axis, the second machining unit interface (28) being arranged at a second side of and at a distance from the work piece holder device interface (16) and such that the second tool holder interface (79) is movable at least along the x- or y-axis, the first side opposing the second side, and at least one work piece transfer unit receiving section (46) provided with a transfer unit interface (48) adapted for receiving a work piece transfer unit (50).

2. Machine base (10) according to claim 1, characterized in that the work piece holder device interface (16) defines an x-z-plane, the first machining unit interface (22) is running parallel or perpendicular to the x-z-plane and adapted for receiving the first machining unit (24), and the second machining unit interface (26) is running parallel or perpendicular to the x-z-plane and adapted for receiving the second machining unit (30).

3. Machine base (10) according to claim 2, characterized in that the transfer unit interface (48) is running parallel to the x-z-plane and adapted for receiving the work piece transfer unit (50) aligned along the x-axis.

4. Machine base (10) according to one of the preceding claims, characterized in that the machine base (10) comprises at least one lateral aligning interface (52) running parallel to the y-z-plane for aligning the machine base (10) with a further machine base (10).

5. Machine base (10) according to one of the preceding claims, characterized in that the machine base (10) comprises at least one front aligning interface (56) running parallel to the x-y-plane for aligning the machine base (10) with a further machine base (10).

6. Machine base (10) according to one of the preceding claims, characterized in that the machine base (10) comprises at least one swiveling device receiving section (58) provided with a swiveling device interface (60) adapted for receiving a swiveling device (62).

7. Machine base (10) according to one of the preceding claims, characterized in that the x-z-plane is running horizontally.

8. Machine base (10) according to claim 7, characterized in that the first machining unit interface (22) is arranged above the holder device interface (16) and facing upwards.

9. Machine base (10) according to one of the claim 7 or 8, characterized in that the second machining unit interface (28) is arranged below the holder device interface (16) and facing downwards.

10. Machine base (10) according to one of the preceding claims, characterized in that the machine base (10) comprises a first work piece holder device receiving section (14.sub.1) provided with a first holder device interface (16.sub.1), a second work piece holder device receiving section (14.sub.2) provided with a second holder device interface (16.sub.2), a primary first machining unit receiving section (20.sub.1) provided with a primary first machining unit interface (22.sub.1), a secondary first machining unit receiving section (20.sub.2) provided with a secondary first machining unit interface (22.sub.2), a primary second machining unit receiving section (26.sub.1) provided with a primary second machining unit interface (28.sub.1), and a secondary second machining unit receiving section (26.sub.2) provided with a secondary second machining unit interface (28.sub.2).

11. Machining system for machining a work piece, comprising at least one machine base (10) according to one of the preceding claims, a work piece holder device (18) connected to the holder device interface (16) and aligned along the z-axis, the work piece holder device (18) being adapted for clamping and aligning a work piece along the z-axis and for moving the work piece along the z-axis, and a first machining unit (24) connected to the first machining unit interface (22) and comprising a first tool holder interface (77) movable at least along the x- or y-axis, and/or a work piece transfer unit (50) connected to the transfer unit interface (48).

12. Machining system according to claim 11, comprising the first machining unit (24) connected to the first machining unit interface (22), the work piece transfer unit (50) connected to the transfer unit interface (48), the work piece transfer unit (50) being aligned along the x-axis, and a second machining unit (30) connected to the second machining unit interface (28) and comprising a second tool holder interface (79) movable at least along the x- or y-axis.

13. Machining system according to one of the claim 11 or 12, comprising a first machine base (10.sub.1) according to one of the claims 1 to 9, a second machine base (10.sub.2) according to one of the claims 1 to 9, the first machine base (10.sub.1) and the second machine base (10.sub.2) connected to each other via the lateral aligning interface (52).

14. Machining system according to claim 11, comprising a third machine base (10.sub.3) according to claims 1 to 9, and a fourth machine base (104) according to claims 1 to 9, the third machine base (10.sub.3) and the fourth machine base (104) connected to each other via the lateral aligning interface (52), the first machine base (10.sub.1) and the third machine base (10.sub.3) connected to each other via the front aligning interface (56), and the second machine base (10.sub.2) and the fourth machine base (104) connected to each other via the front aligning interface (56).

15. Machining system for machining a work piece, comprising a machine base (10) according to claim 10, a first work piece holder device (18.sub.1) connected to the first holder device interface (16.sub.1) and aligned along the z-axis, a second work piece holder device (18.sub.2) connected to the second holder device interface (16.sub.2) and aligned along the z-axis, a primary first machining unit (24.sub.1) connected to the primary first machining unit interface (22.sub.1), a secondary first machining unit (24.sub.2) connected to the secondary first machining unit interface (22.sub.2), a primary second machining unit (30.sub.1) connected to the primary second machining unit interface (28.sub.1), a secondary second machining unit (30.sub.2) connected to the secondary second machining unit interface (28.sub.2), and a work piece transfer unit (50) connected to the transfer unit interface (48), the work piece transfer unit (50) being aligned along the x-axis.

16. Machining system according to claim 15, comprising a first machine base (10.sub.1) according to claim 10, a second machine base (10.sub.2) according to claim 10, the first machine base (10.sub.1) and the second machine base (10.sub.2) connected to each other via the front aligning interface (56).

17. Machining system according to one of the claim 14 or 16, comprising at least one swiveling device (62) connected to the swiveling device interface (60).

18. Machining system according to claim 11 or claim 17, characterized in that the work piece holder device (18), the work piece transfer unit (50) or the swiveling device (62) are adapted for receiving a palette (91).

Description

[0080] The present invention is described in detail with reference to the drawings attached wherein

[0081] FIG. 1A is a perspective view of a first embodiment of the present machine base,

[0082] FIG. 1B is a side view of the section P as indicated in FIG. 1B not drawn to scale,

[0083] FIG. 1C is a top view of the second machining unit receiving section,

[0084] FIG. 1D is a bottom view of the work piece holder device receiving section,

[0085] FIG. 2A is a perspective view of a second embodiment of the present machine base,

[0086] FIG. 2B is a bottom view of the work piece holder device receiving sections,

[0087] FIG. 3 is a perspective view of a first embodiment of the present machining system,

[0088] FIG. 4 is a perspective view of a work piece holder device of the present machining system,

[0089] FIG. 5A is a front perspective view of a second embodiment of the present machining system,

[0090] FIG. 5B is a back perspective view of the second embodiment of the present machining system,

[0091] FIG. 6A is a perspective front view of a third embodiment of the present machine base,

[0092] FIG. 6B is a perspective back view of the third embodiment of the present machine base according to FIG. 6A,

[0093] FIG. 7A is a perspective front view of a third embodiment of the present machining system,

[0094] FIG. 7B is a perspective back view of the third embodiment of the present machining system according to FIG. 7A,

[0095] FIG. 8A is a front perspective view of a fourth embodiment of the present machining system,

[0096] FIG. 8B is a front perspective view of the fourth embodiment of the present machining system according to FIG. 8A where some parts are omitted,

[0097] FIG. 9 is a top view of a fourth embodiment of a machining system,

[0098] FIG. 10A is a first perspective view of a swiveling device,

[0099] FIG. 10B is a second perspective view of the swiveling device,

[0100] FIGS. 11A to 11D are principle sketches explaining modes the machining system of FIG. 9 may be operated,

[0101] FIG. 12 is a perspective view of a palette and of a clamping device,

[0102] FIG. 13 is a perspective view of a machining system comprising a work piece transfer unit adapted for transferring palettes,

[0103] FIG. 14A a first embodiment of a work piece transfer unit in a first position,

[0104] FIG. 14B the work piece transfer unit of FIG. 14A in a second position,

[0105] FIG. 15A a second embodiment of the work piece transfer unit in a first position, and

[0106] FIG. 15B the second embodiment of the work piece transfer unit in a second position.

[0107] Reference will now be made in detail to the present exemplary bodies of the disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, the same or similar reference numbers will be used throughout.

[0108] FIG. 1A is a perspective view of a first embodiment of the present machine base 10.sub.1. The machine base 10.sub.1 defines an x,y,z-coordinate system 12 and comprises a work piece holder device receiving section 14. The work piece holder device receiving section 14 is provided with a work piece holder device interface 16 defining an x-z-plane and is adapted for receiving a work piece holder device 18 (see FIG. 4) aligned along a z-axis of the coordinate system 12.

[0109] Moreover, the machine base 10.sub.1 according to the first embodiment comprises a first machining unit receiving section 20 provided with a first machining unit interface 22. The first machining unit interface 22 runs parallel to the x-z-plane and is adapted for receiving a first machining unit 24 (see FIG. 3).

[0110] Beyond that the machine base 10.sub.1 according to the first embodiment comprises a second machining unit receiving section 26 provided with a second machining unit interface 28 (see also FIG. 1D). Like the first machining unit interface 22 the second machining unit interface 28 runs parallel to the x-z-plane and is adapted for receiving a second machining unit 30 (see FIG. 5B).

[0111] In the first embodiment the first machining unit interface 22 is located on a first traverse girder 32 while the work piece holder device interface 16 and the second machining unit interface 28 are arranged on a common second traverse girder 34 running parallel to the first traverse girder 32. The first traverse girder 32 and the second traverse girder 34 run between a first side wall 36 and a second side wall 38 of the machine base 10.sub.1. The second traverse girder 34 is separately shown in FIGS. 10 and 1D.

[0112] The x-z-plane is running horizontally. The first machining unit interface 22 is arranged above the work piece holder device interface 16 and is facing upwards. The second machining unit interface 28 is arranged below the work piece holder device interface 16 and is facing downwards.

[0113] Moreover the machine base 10.sub.1 of the first embodiment comprises a base traverse girder 40 running between the first side wall 36 and the second side wall 38 near the ground end of the machine base 10.sub.1.

[0114] As the second machining unit interface 28 is facing downwards the work piece holder device interface 16 is facing upwards. As a consequence the first machining unit interface 22 is situated at a first side of and at a distance from the work piece holder device interface 16 and the second machining unit interface 28 is situated at a second side of and at a distance from the work piece holder device interface 16, the first side opposing the second side. Due to the fact that the work piece holder device interface 16 and the second machining unit interface 28 are arranged on the common second traverse girder 34 the distance between the work piece holder device interface 16 and the second machining unit interface 28 is smaller than the distance between the work piece holder device interface 16 and the first machining unit interface 22.

[0115] It is also possible to arrange the work piece holder device interface 16 on the first traverse girder 32 facing downwards. The arrangement is chosen depending on the stiffness to be obtained. The machining unit being mounted with the lower stiffness may arranged at a smaller distance to the work piece holder device interface 16 than the machining unit mounted with a higher stiffness, thereby enhancing the accuracy of the machining.

[0116] As mentioned above, the work piece holder device interface 16 and the first and second machining unit interfaces 22, 28 are adapted for receiving the work piece holder device 18 aligned along the z-axis and the first and the second machining unit 24, 30. To ensure the alignment along the z-axis the work piece holder device interface 16 and the first and second machining unit interfaces 22,28 are equipped with aligning means 42, in this case with recesses 44 that interact with corresponding protrusions (not shown) of the respective work piece holder device 18 and the first and the second machining unit 24, 30. It is thus only possible to connect the work piece holder device 18 and the first and the second machining unit 30 with the work piece holder device interface 16 and the first and second machining unit interfaces 22, 28.

[0117] The machine base 10.sub.1 in accordance with the first embodiment further comprises a work piece transfer unit receiving section 46 provided with a work piece transfer unit interface 48 running parallel to the x-z-plane (see also FIG. 1B). The work piece transfer unit receiving section 46 is adapted for receiving a work piece transfer unit 50 aligned along the x-axis (see FIGS. 9 and 10). It is evident from FIGS. 1A and 1B that the work piece transfer unit interface 48 is located on a projection of the first traverse girder 32 with reference to the first side wall 36 and the second side wall 38. When connected to the work piece transfer unit interface 48 the work piece transfer unit 50 abuts against the first side wall 36 and the second side wall 38 so that the work piece transfer unit 50 is aligned along the x-axis.

[0118] The machine base 10.sub.1 of the first embodiment further comprises first lateral aligning interfaces 52.sub.1 and second lateral aligning interfaces 52.sub.2 running parallel to the y-z-plane for aligning the machine base 10.sub.1 with one or more further machine bases 10.sub.1 located laterally of the machine base 10.sub.1. In the first embodiment the first lateral aligning interfaces 52.sub.1 are formed by lateral extensions 54 formed by the first and the second side wall 36, 38 or connected to the first and second side wall 36, 38. The second lateral aligning interfaces 52.sub.2 are formed by a foot 55 of the machine base 10.sub.1.

[0119] Beyond that the machine base 10.sub.1 in accordance with the first embodiment comprises at least one front aligning interface 56 running parallel to the x-y-plane for aligning the machine base 10.sub.1 with a further machine base 10.sub.1 located opposite of the machine base 10.sub.1. The machine base 10.sub.1 of the first embodiment comprises two front aligning interfaces 56 formed by the side walls 36, 38.

[0120] Furthermore the machine base 10.sub.1 in accordance with the first embodiment comprises at least one swiveling device receiving section 58 provided with a swiveling device interface 60 that is located on the first side wall 36 of the machine base 10.sub.1 and thus running parallel to the y-z-plane. The swiveling device receiving section 58 is adapted for receiving a swiveling device 62 (see FIGS. 10A and 10B).

[0121] In FIG. 2A a second embodiment of the machine base 10.sub.2 is shown. The principle structure of the machine base 10.sub.2 according to the second embodiment is the same as the structure of the machine base 10.sub.1 according to the first embodiment. In contrast to the first embodiment the machine base 10.sub.1 of the second embodiment comprises a first work piece holder device receiving section 14.sub.1 provided with a first work piece holder device interface 16.sub.1, a second work piece holder device receiving section 14.sub.2 provided with a second work piece holder device interface 16.sub.2, a primary first machining unit receiving section 20.sub.1 provided with a primary first machining unit interface 22.sub.1, a secondary first machining unit receiving section 20.sub.2 provided with a secondary first machining unit interface 22.sub.2, a primary second machining unit receiving section 26.sub.1 provided with a primary second machining unit interface 28.sub.1, and a secondary second machining unit receiving section 26.sub.2 provided with a secondary second machining unit interface 28.sub.2 (see FIG. 2B which is a bottom view of the second traverse girder 34).

[0122] The machine base 10.sub.1 of the second embodiment comprises an upper middle wall 64 arranged between the first traverse girder 32 and the second traverse girder 34. Moreover the machine base 10.sub.2 according to the second embodiment comprises a lower middle wall 66 running between the second traverse girder 34 and the base traverse girder 40. The lower middle wall 66 forms a further front aligning interface 56.

[0123] FIG. 3 shows a perspective view of a first embodiment of a machining system 68.sub.1. The machining system 68.sub.1 comprises the machine base 10.sub.2 according to the second embodiment. Beyond that the machining system 68.sub.1 is equipped with a first work piece holder device 18.sub.1 connected to the first work piece holder device interface 16.sub.1 (not visible, cf. FIG. 2A) and aligned along the z-axis, and a second work piece holder device 18.sub.2 connected to the second work piece holder device interface 16.sub.2 and aligned along the z-axis (see FIG. 2A).

[0124] The machining system 68.sub.1 further comprises a primary first machining unit 24.sub.1 connected to the primary first machining unit interface 22.sub.1, the primary first machining unit 24, and a secondary first machining unit 24.sub.2 connected to the secondary first machining unit interface 22.sub.2, the secondary first machining unit 24.sub.2. Moreover the machining system 68.sub.1 comprises a primary second machining unit 30.sub.1 connected to the primary second machining unit interface 28.sub.1, and a secondary second machining unit 30.sub.2 connected to the secondary second machining unit interface 28.sub.2.

[0125] Moreover the machining system 68.sub.1 according to the first embodiment comprises a work piece transfer unit 50 connected to the work piece transfer unit interface 48 (see FIG. 1B), the work piece transfer unit 50 being aligned along the x-axis. A work piece can be transported along the x-axis and being clamped for machining into the first work piece holder device 18.sub.1 and the second work piece holder device 18.sub.2. Consequently the work piece can be machined by in total four machining units 24, 30.

[0126] In FIG. 4 a work piece holder device 18 is separately shown. In its basic design the work piece holder device 18 comprises a work piece holding section 70 that may be equipped with a jaw chuck, a collet clamping or the like. The work piece can be inserted into the work piece holding section 70 from a front end or from a rear end by a translational movement along the z-axis. The work piece holding device section 70 is movably mounted along the z-axis on a support structure 72. In the basic design the work piece holding section 70 is not rotatable around the z-axis, however, if desired the work piece holder device 18 may be adjusted to allow the rotation of the work piece holding section 70 around the z-axis in addition to the translational movement along the z-axis.

[0127] The first machining unit 24 comprises a first tool holder interface 77 in this embodiment formed by a cube shaped body 74 running parallel to the x-y-axis and movable at least along the x or y-axis (see also FIG. 7A). Accordingly, the second machining unit 30 comprises a second tool holder interface 79 also running parallel to the x-y-axis and movable at least along the x- or y-axis. Any kind of tool holding devices 84 (not shown in FIG. 3 but see FIG. 5A) can be connected to the first and the second tool holder interface 77, 79. The movement of the first and second tool holder interfaces 77, 79 is transferred to the tool holding devices 84 connected hereto. In case the tool holding devices 84 should provide a rotary movement they are equipped with individual motors (not shown).

[0128] With reference to FIG. 3 the tool holder interfaces 77, 79 are at least movable along the y-axis so that a tool connected to the tool holding device 84 (FIG. 5A) may be moved relative to the work piece holder device 18. As explained above, the work piece holder device 18 is at least movable along the z-axis so that a relative movement between a tool and the work piece necessary for the machining of the work piece is possible.

[0129] In order to protect the machining units 24, 30 from chips and other debris produced upon machining of a work piece the machining system 68.sub.1 comprises a number of protective walls 76 mounted on the machine base 10.sub.1 and arranged in front of the respective machining units 24, 30. The protective walls 76 comprise openings which may be traversed by the cube shaped body 74 of the machining units 24, 30. Depending on the design of the machining units 24, 30 the respective tool holder interfaces 77, 79 may be movable along the x-axis, the y-axis and the z-axis of the coordinate system 12. To allow the movement along the x-axis and the y-axis the openings of the protective walls 76 must be sufficiently big, the openings are covered by a shutting unit 78 such as telescopic protections, sheet pockets or similar 80. To provide an adequate protection of the machining units 24, 30 from chips and the like the openings are closed by a sheet pocket 80 movable by the cube shaped body 74 along the x-axis and the y-axis. As the sheet pockets 80 entirely close the openings they cannot be traversed by chips and the like.

[0130] In FIGS. 5A and 5B a second embodiment of the machining system 68.sub.2 is shown by two different perspectives. In this case a work spindle 82 is connected to the first tool holder interface 77 of the secondary first machining unit 24.sub.2. Accordingly, another work spindle 82 is connected to the second tool holder interface 79 of the secondary second machining unit 30.sub.2 (see FIG. 5B). The work spindles 82 are equipped with a motor (not shown) which generates the rotary movement around the y-axis. To the second tool holder interface 79 of the primary second machining unit 30.sub.1 a tool holding device 84 is connected into which a plurality of tools can be inserted aligned along the x-axis, the y-axis or the z-axis. The tool holding device 84 is movable at least along the x-axis or the y-axis. The tools inserted into the tool holding device 84 may not necessarily be rotatable around their own axis.

[0131] As particularly evident from FIG. 5B the primary first machining unit 24.sub.1 is rotated by 180° around the z-axis with respect to the primary second machining unit 30.sub.1. The secondary first machining unit 24.sub.2 is also rotated by 180° around the z-axis with respect to the secondary second machining unit 30.sub.2.

[0132] FIG. 6A is a perspective front view and FIG. 6B is a perspective back view of a third embodiment of a machine base 10.sub.3 which is to a large extent identical to the machine base 10.sub.2 of the second embodiment. Therefore, only the differences are discussed in the following. Between the first side wall 36 and the lower middle wall 66 the machine base 10.sub.3 comprises a first intermediate wall 65 and between the second side wall 38 and the lower middle wall 66 a second intermediate wall 67. The first and second intermediate walls 65, 67 run perpendicular to the first and second traverse girders 32, 34 and thus parallel to the vertical x-y-plane. In the third embodiment of the machine base 10.sub.3 the primary second machining unit receiving section 26.sub.1 and the primary second machining unit interface 28.sub.1 are located on the first intermediate wall. The secondary second machining unit receiving section 26.sub.2 and the secondary second machining unit interface 28.sub.2 are located on the second intermediate wall.

[0133] In FIGS. 7A and 7B a machining system 68.sub.3 according to a third embodiment is shown by means of a perspective front view and a perspective back view, respectively. The machining system 68.sub.3 comprises a machine base 10.sub.3 according to the third embodiment shown in FIGS. 6A and 6B. The principle setup of the machining system 68.sub.3 of the third embodiment is to a large extent the same as explained for the machining system 68.sub.1 of the first embodiment and the machining system 68.sub.2 of the second embodiment. However, due to the different orientation of the primary second machining unit receiving section 26.sub.1 and the primary second machining unit interface 28.sub.1 as well as the secondary second machining unit receiving section 26.sub.2 and the secondary second machining unit interface 28.sub.2 the primary first machining unit 24.sub.1 is not mirrored to the primary second machining unit 30.sub.1 and the secondary first machining unit 24.sub.2 is not mirrored to the secondary second machining unit 30.sub.2. Instead they are arranged relative to each other rotated by 90° around the x-axis.

[0134] In FIG. 8A a machining system 68.sub.4 according to a fourth embodiment is shown by means of a perspective view. The machining system 68.sub.4 comprises two machine bases 10.sub.2 according to the second embodiment shown in FIG. 2A that are oppositely arranged to each other and aligned to each other by the front aligning interfaces 56. The two machine bases 10.sub.2 could also be integrated into one single machine base (not shown). The design of the two machine bases 10.sub.2 substantially the same so that the machining system 68.sub.4 of the fourth embodiment comprises four work piece holder devices 18 connected to a corresponding number of work piece holder device interfaces 16 and eight machining units 24, 30 connected to a corresponding number of machining unit interfaces 22, 28. Beyond that the machining system 68.sub.4 may comprise a first work piece transfer unit 50.sub.1 connected to a first work piece transfer unit interface 48 of the first machine base 10.sub.1 and a second work piece transfer unit 50.sub.2 connected to a second work piece transfer unit interface 48 of the second machine base 10.sub.1 (see FIG. 7).

[0135] For the sake of clarity only one of the machine bases 10.sub.2 is shown in FIG. 8B. A tool holding device 84 embodied as a revolver 88 is connected to the first tool holder interface 77 of the primary first machining unit 24.sub.1. A number of tools may be mounted on the revolver 88. The tools may be rotatable around their own axes. A tool holding device 84 is connected to the second tool holder interface 79 of the primary second machining unit 30.sub.1. A tool changer 86 is connected to the first tool holder interface 77 of the machining unit opposite of the secondary first machining unit 24.sub.2 (not shown).

[0136] In FIG. 9 a fifth embodiment of the machining system 68.sub.5 according to the invention is shown by means of a top view. The principle layout of the machining system 68.sub.5 according to the fifth embodiment is to a large extent the same as the layout of the machining system 68.sub.4 according to the fourth embodiment. However, the machining system 68.sub.5 of the fifth embodiment comprises a first machine base 10a, a second machine base 10b, a third machine base 10c and a fourth machine base 10d, all according to the first embodiment shown in FIG. 1A. The first machine base 10a and the second machine base 10b are connected to each other via the lateral aligning interface 52. Likewise, the third machine base 10c and the fourth machine base 10d are connected to each other via the lateral aligning interface 52. The first machine base 10.sub.1 and the third machine base 10.sub.1 are connected to each other via the front aligning interface 56 and the second machine base 10b and the fourth machine base 10d are connected to each other via the front aligning interface 56.

[0137] The machining system 68.sub.5 of the fifth embodiment comprises a swiveling device 62 connected to the swiveling device 62 interface of the second machine base 10b. The swiveling device 62 is separately shown in FIGS. 10A and 10B. The swiveling device 62 is rotatable around the x-axis and comprises a gripping device 90 for gripping a work piece 91 or for gripping a palette 93 (see FIG. 12).

[0138] The machining system 68.sub.4 according to the fourth and the machining system 68s according to the fifth embodiment may be subdivided into four machining stations 92.sub.1 to 92.sub.4, each of which comprise a work piece holder device 18, a first machining unit 24 and a second machining unit 30. The machining system 68s may be operated in many different modes, some of which are explained in the following.

[0139] In a first mode which is schematically shown in FIG. 11A the four machining stations 92.sub.1 to 92.sub.4 may be operated independent from each other. A raw first work piece to be machined may be delivered to the first machining station 92.sub.1 by means of the first work piece transfer unit 50.sub.1. While the first work piece is machined in the first machining station 92.sub.1 the first work piece transfer unit 50.sub.1 may deliver a second work piece to the second machining station 92.sub.2. After the first work piece is finished the first work piece transfer unit 50.sub.1 unloads the first work piece from the first machining station 92.sub.1 and loads the first machining station 92.sub.1 with a new raw work piece. Subsequently the first work piece transfer unit 50.sub.1 unloads the second work piece from the second machining station 92.sub.2. The same steps may be conducted inside the third machining station 92.sub.3 and the fourth machining station 92.sub.4. The first work piece transfer unit 50.sub.1 and the second work piece transfer unit 50.sub.2 may be designed in a way that they may simultaneously load and unload the work pieces.

[0140] In a second mode which is schematically shown in FIG. 11B a first work piece is machined in the first and the second machining station 92.sub.1, 92.sub.2 and a second work piece is simultaneously machined in the third and the fourth machining station 92.sub.3, 92.sub.4. The first work piece transfer unit 50.sub.1 delivers the raw first work piece to the first machining station 92.sub.1. After the machining in the first machining station 92.sub.1 is finished the first work piece transfer unit 50.sub.1 transports the first work piece to the second machining station 92.sub.2. When the machining of the first work piece in the second machining station 92.sub.2 is finished the first work piece transfer unit 50.sub.1 unloads the finished first work piece from the machining system 68.sub.5. The same steps may be conducted inside the third machining station 92.sub.3 and the fourth machining station 92.sub.4.

[0141] In a third mode which is schematically shown in FIG. 11C the first work piece transfer unit 50.sub.1 delivers the raw first work piece to the first machining station 92.sub.1. After the machining is finished the work piece is transferred to the opposite third machining station 92.sub.3. This transfer is conducted by the two work piece holder devices 18 that are located in proximity to each other along the z-axis. When the machining of the first work piece in the third machining station 92.sub.3 is finished the first work piece is transferred to the fourth machining station 92.sub.4 by means of the second work piece transfer unit 50.sub.2. Once the machining in the fourth machining station 92.sub.4 is finished the work piece is transferred to the second machining station 92.sub.2 again by locating the two work piece holder devices 18 in proximity to each other along the z-axis. The first work piece transfer unit 50.sub.1 unloads the finished work piece from the machining system 68.sub.5 once the machining of the work piece in the second machining station 92.sub.2 is finished.

[0142] In a fourth mode which is schematically shown in FIG. 11D the machining of the work piece is to a large extent the same as in the third mode, however, the transfer of the work piece between the fourth machining station 92.sub.4 and the second machining station 92.sub.2 is conducted by means of the swiveling device 62. The difference in the two transfers is that the work piece is rotated around the x-axis by the swiveling device 62 so that the same end of the work piece is inserted into the work piece holding section 70 of the work piece holder device 18.

[0143] The machining system 68.sub.4, 68s of the fourth and fifth embodiment may be operated by many more modes that are combinations and/or modifications of the modes presented above.

[0144] As already mentioned the swiveling device 62 is separately shown in FIGS. 10A and 10B. In FIG. 10A the gripping device 90 of the swiveling device 62 is adapted for receiving the work piece 91 whereas in FIG. 10B the gripping device 90 is adapted for receiving the palette 93 that is shown in greater detail in FIG. 12. The palette 93 comprises a precise palette interface 95 that can be clamped into the jaw chucks of the work piece holding sections 70 of the work piece holder device 18. The palette 93 itself comprises a clamping section 99 that may comprise a chuck, a collet device or similar 97 into which a work piece 91 may be clamped (see FIG. 10B).

[0145] FIG. 13 shows the machining system 68.sub.1 along the lines with the first embodiment, however, the work piece transfer unit 50 in this case transfers the palette 93 between the different work piece holder devices 70. The work piece 91 remains clamped in the palette 93 throughout the entire machining. Due to the fact that a work piece may remain clamped inside the palette 93 throughout the entire machining the machining precision is considerably higher compared to a work piece 91 that is released and re-clamped each time it is machined by another machining unit.

[0146] In FIGS. 14A and 14B a first embodiment of the work piece transfer unit 50.sub.1 is shown by means of a principle sketch which may be incorporated into a machining system 68 according to one of the presented embodiments, for example into the machining system 68.sub.4 according to the fourth embodiment. The work piece transfer unit 50.sub.1 comprises a slide 94 that is movably mounted on a sliding track 96 that is aligned along the x-axis. In the first embodiment the slide 94 comprises a first clamping section 100.sub.1 and a second clamping section 100.sub.2 and one loading and unloading device 98 located on one side of the machining system 68.sub.4.

[0147] In a first position (see FIG. 14B) a finished work piece 101.sub.1 located in the first clamping section 100.sub.1 is unloaded by the loading and unloading device 98 and a raw work piece 101.sub.2 is loaded into the second clamping section 100.sub.1, also by the loading and unloading device 98. Depending on the design of the loading and unloading device 98 the slide 94 is moved between the unloading and the loading processes. The first clamping section 100.sub.1 remains empty. After that the slide 94 is moved along the sliding track 96 so that the empty first clamping section 100.sub.1 is placed in front of the work piece holding section 70 of the first work piece holder device 18.sub.1. A work piece 101.sub.3 machined by the first machining station 92.sub.1 is inserted into the first clamping section 100.sub.1. In the next step the slide 94 is moved into a positon in which the raw work piece 101.sub.2 can be inserted into the work piece holding section 70 of the first work piece holder device 18 and be machined. The second clamping section 100.sub.2 is now empty.

[0148] Depending on the mode the machining system 68.sub.1 is operated the work piece machined in the first machining station 92.sub.1 is not machined any further and the slide 94 moved into a position in which the machined work piece 101.sub.3 can be unloaded from the first clamping section 100.sub.1 and a new raw work piece 101.sub.2 inserted into the second clamping section 100.sub.2.

[0149] In case the work piece 101.sub.3 is further machined in the second machining station 92.sub.1 the slide 94 is moved into a position in which a work piece 101.sub.1 machined in the second machining station 92.sub.1 (not shown) can be inserted into the empty second clamping section 100.sub.2. Subsequently the slide 94 is moved into a position in which the work piece 101.sub.3 machined in the first machining station 92.sub.1 can be inserted into the work piece holding section 70 of the second work piece holder device 18.sub.2. In the meantime the work piece 101.sub.1 machined in the second machining station 92.sub.1 is unloaded from the second clamping section 100.sub.2 and a raw work piece 101.sub.2 is inserted into the first clamping section 100.sub.1.

[0150] In FIGS. 15A and 15B a second embodiment of the work piece transfer unit 50.sub.2 is shown which mainly differs from the first embodiment in that the slide 94 comprises three clamping sections 100.sub.1, 100.sub.2, 100.sub.3. Moreover the work piece transfer unit 50 of the second embodiment comprises a loading device 10.sub.2 on one side of the machining system 68.sub.1 and an unloading device 104 on the opposite side of the machining system 68.sub.1. The three clamping sections 100.sub.1, 100.sub.2, 100.sub.3 are arranged on the slide 94 so that in the appropriate position they can be accessed by the work piece holding sections 70 of the first and the second work piece holder devices 18.sub.1, 18.sub.2 and of the loading device 102 or the unloading device 104.

[0151] In this case the slide 94 can be moved between two positions. In the first position (FIG. 15A) a raw work piece is inserted into the first clamping section 100.sub.1 by the loading device 102. A work piece readily machined in the first machining station 92.sub.1 is inserted into the second clamping section 100.sub.2 and the finished work piece machined in the second machine station 92.sub.2 is inserted into the second clamping section 100.sub.2. After that the slide 94 is moved into a second position (see FIG. 15B) in which the raw work piece is withdrawn from the first clamping section 100.sub.1 for machining in the first machining station 92.sub.1, the work piece machined in the first machining station 92.sub.1 is withdrawn from the second clamping section 100.sub.2 for machining in the second machining station 92.sub.2 and the finished work piece is withdrawn from the third clamping section 100.sub.3 by the unloading device 104 on the right hand side of the machining system 68.sub.4. The empty slide 94 is then moved back to the first position and the steps described repeated.

REFERENCE LIST

[0152] 10 machine base [0153] 10.sub.1 machine base according to a first embodiment [0154] 10.sub.2 machine base according to a second embodiment [0155] 10.sub.3 machine base according to a third embodiment [0156] 10a first machine base [0157] 10b second machine base [0158] 10c third machine base [0159] 10d fourth machine base [0160] 12 coordinate system [0161] 14 work piece holder device receiving section [0162] 16 work piece holder device interface [0163] 18 work piece holder device [0164] 20 first machining unit receiving section [0165] 20.sub.1 primary first machining unit receiving section [0166] 20.sub.2 secondary first machining unit receiving section [0167] 22 first machining unit interface [0168] 22.sub.1 primary first machining unit interface [0169] 22.sub.2 secondary first machining unit interface [0170] 24 first machining unit [0171] 24.sub.1 primary first machining unit [0172] 24.sub.2 secondary first machining unit [0173] 26 second machining unit receiving section [0174] 26.sub.1 primary second machining unit receiving section [0175] 26.sub.2 secondary second machining unit receiving section [0176] 28 second machining unit interface [0177] 28.sub.1 primary second machining unit interface [0178] 28.sub.2 secondary second machining unit interface [0179] 30 second machining unit [0180] 30.sub.1 primary second machining unit [0181] 30.sub.2 secondary second machining unit [0182] 32 first traverse girder [0183] 34 second traverse girder [0184] 36 first side wall [0185] 38 second side wall [0186] 40 base traverse girder [0187] 42 aligning means [0188] 44 recess [0189] 46 work piece transfer unit receiving section [0190] 48 work piece transfer unit interface [0191] 50 work piece transfer unit [0192] 50.sub.1 first work piece transfer unit [0193] 50.sub.2 second work piece transfer unit [0194] 52 lateral aligning interface [0195] 54 lateral extension [0196] 56 front aligning interface [0197] 58 swiveling device receiving section [0198] 60 swiveling device interface [0199] 62 swiveling device [0200] 64 upper middle wall [0201] 65 first intermediate wall [0202] 66 lower middle wall [0203] 67 second intermediate wall [0204] 68 machining system [0205] 68.sub.1 to 68.sub.5 embodiments of the machining system [0206] 70 work piece holding section [0207] 72 support structure [0208] 74 cube shaped body [0209] 76 protective wall [0210] 77 first tool holder interface [0211] 78 shutting unit [0212] 79 second tool holder interface [0213] 80 sheet pocket [0214] 82 work spindle [0215] 84 tool holding device [0216] 86 tool changer [0217] 88 revolver [0218] 90 gripping device [0219] 91 work piece [0220] 92 machine station [0221] 92.sub.1 to 92.sub.4 first to fourth machine station [0222] 93 palette [0223] 94 slide [0224] 95 palette interface [0225] 96 sliding track [0226] 97 chuck [0227] 98 loading and unloading device [0228] 99 clamping section of palette [0229] 100 clamping section [0230] 100.sub.1 first clamping section [0231] 100.sub.2 second clamping section [0232] 100.sub.3 third clamping section [0233] 102 loading device [0234] 104 unloading device