MACHINE TOOL FOR MACHINING A WORKPIECE

Abstract

The present invention relates to a machine tool 100 for machining a workpiece 12 by means of a tool 22, which comprises a clamping means 11 for clamping the workpiece 12 and a support means 21 for receiving the tool 22, wherein the clamping means 11 is mounted on a spindle head of a clamping means-carrying work spindle 10 and the support means 21 is mounted on a spindle head of a support means-carrying work spindle 20, and the machine tool 100 is designed to position the two work spindles 10, 20 by means of numerically controllable axes in relation to one another in such a way that the workpiece 12, which is clamped in the clamping means 11, can be processed by the tool 22, which is received in the support means 21.

Claims

1. A machine tool for machining a workpiece by means of a tool, wherein the machine tool comprises a clamping means for clamping the workpiece and a support means for receiving the tool, characterized in that the clamping means is mounted on a spindle head of a clamping means-carrying work spindle, and the support means is mounted on a spindle head of a support means-carrying work spindle, and the machine tool is designed to position the two work spindles in relation to one another by means of numerically controllable axes in such a way that the workpiece clamped in the clamping means can be processed by the tool received in the support means.

2. The machine tool according to claim 1, characterized in that the two work spindles are designed to carry both a support means for receiving a tool and a clamping means for clamping a workpiece.

3. The machine tool according to claim 1, characterized in that each of the two work spindles can be positioned in relation to one another by at least one rotational axis and at least one linear axis.

4. The machine tool according to claim 3, characterized in that a first of the two work spindles can be positioned about a first rotational axis and along a first linear axis in relation to the second of the two work spindles, and the second work spindle can be positioned about a second rotational axis which runs parallel to the first rotational axis and along a second linear axis and a third linear axis, which run both perpendicularly to one another and perpendicularly to the first linear axis.

5. The machine tool according to claim 1, characterized in that the two work spindles are designed to adopt a basic position in which the spindle axes lie in one plane, wherein, proceeding from the basic position, a coaxial arrangement of the two working spindles can be achieved by positioning the work spindles in relation to one another just by a rotary motion about a respective rotational axis perpendicular to the plane.

6. The machine tool according to claim 1, characterized in that the machine tool also has a manipulator, which is designed to introduce and exchange, at the two work spindles, both the workpiece-carrying and/or non-workpiece-carrying clamping means and the tool-carrying and/or non-tool-carrying support means.

7. The machine tool according to claim 6, characterized in that the machine tool also has a magazine that is designed to place down workpiece-carrying and non-workpiece-carrying clamping means as well as to place down tool-carrying and non-tool-carrying support means, wherein the manipulator is also designed to remove the respective clamping or support means from the magazine.

8. The machine tool according to claim 7, characterized in that the machine tool has two magazines which are designed to place down workpiece-carrying and non-workpiece-carrying clamping means as well as to place down tool-carrying and non-tool-carrying support means, and has one or two manipulators which are designed to introduce and exchange workpiece-carrying and/or non-workpiece-carrying clamping means and tool-carrying and/or non-tool-carrying support means at the work spindles.

9. The machine tool according to claim 8, characterized in that the magazines are designed as wheel magazines and the manipulators are designed as double grippers.

10. The machine tool according to claim 1, characterized in that the spindle axis of the work spindles is disposed horizontally.

11. The machine tool according to claim 10, characterized in that a first of the two work spindles is arranged on a console at the machine bed and the second of the two work spindles is arranged on the machine bed in such a way that it is guided on a cross table.

12. The machine tool according to claim 1, characterized in that the clamping means is an external clamping means or an internal clamping means.

13. A method for machining a workpiece by means of a tool in a machine tool according to claim 1, the method comprising the following steps: clamping the workpiece in a clamping means which is mounted on a first work spindle, receiving the tool in a support means which is mounted on a second work spindle, processing a first side of the workpiece by means of the tool according to an NC program.

14. The method according to claim 13, characterized by the following step: exchanging the tool-carrying support means of the second work spindle and introducing a non-workpiece-carrying clamping means.

15. The method according to claim 14, characterized by the following step: transferring the workpiece from the workpiece-carrying clamping means of the first work spindle to the non-workpiece-carrying clamping means of the second work spindle.

16. The method according to claim 15, characterized by the following steps: exchanging the non-workpiece-carrying clamping means of the first work spindle and introducing a tool-carrying support means, processing a second side of the workpiece, which is opposite the already processed first side of the workpiece, by means of the tool which is received in the support means of the first work spindle, according to the NC program.

17. The method according to claim 15, characterized in that the two work spindles adopt a coaxial arrangement in relation to one another before handing over the workpiece from the first work spindle to the second work spindle.

18. The method according to claim 17, characterized in that the following steps are carried out before the two work spindles adopt the coaxial arrangement: adopting a basic position, in which the spindle axes lie in one plane, and rotating one of the two work spindles about a respective rotational axis perpendicular to the plane up to a coaxial alignment of the spindle axes of the two work spindles.

19. The method according to claim 15, characterized in that the workpiece is handed over from the first work spindle to the second work spindle in such a way that during the handover the two work spindles are in contact with the workpiece.

20. The method according to claim 15, characterized in that the workpiece is handed over from the first work spindle to the second work spindle by means of a manipulator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0057] FIG. 1 shows, by way of diagram, the machine tool according to an embodiment with a machine bed and the work spindles which are mounted thereon and which can be positioned in relation to one another according to the illustrated three linear axes and two rotational axes;

[0058] FIG. 2 shows, by way of diagram, the machine tool in a further embodiment with two wheel magazines and two double grippers, wherein the work spindles are mounted on the machine bed of the machine tool and can be positioned in relation to one another in accordance with the numerically controllable axes from FIG. 1;

[0059] FIG. 3 shows, by way of diagram, the machine tool with two wheel magazines and two double grippers in a basic position of the work spindles;

[0060] FIG. 4 shows, by way of diagram, the handover of a workpiece between a first work spindle and a second work spindle according to an embodiment of the method according to the invention;

[0061] FIG. 5 shows a flow diagram of an embodiment of the method according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS AND PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

[0062] In the following, examples and/or embodiments of the present invention are described in detail with reference to the enclosed drawings.

[0063] However, it should be noted that the present invention is by no means limited or confined to the below described embodiments and the design features thereof but also comprises modifications of the embodiments, in particular those which are comprised by modifications of the features of the described examples and/or by combination of individual or a plurality of the features of the described examples on the basis of the scope of protection of the independent claims.

[0064] FIG. 1 shows, by way of diagram, the machine tool 100 with the machine bed 80 and the work spindles 10 and 20, which are mounted thereon and can be positioned in relation to one another according to the illustrated three linear axes L1, L2 and L3 and two rotational axes R1 and R2.

[0065] This embodiment concerns a machine tool 100, in which both the first work spindle 10 and the second work spindle 20 are mounted on the machine bed 80 in a kind of console design. However, it should be noted herein that the machine tool according to the invention is not limited to the described design. On the contrary, console designs and cross table designs and also column-type designs or the like as well as the most different combinations of said designs can be used.

[0066] The division of the numerically controllable axes of the machine tool 100 according to FIG. 1 is such that the first work spindle 10 can be moved vertically along the linear axis L1 and can be rotated about the rotational axis R1, which is parallel to the linear axis L1. The second work spindle 20 can be positioned horizontally in a plane by means of the linear axes L2 and L3, wherein the linear axis L3 positions the second work spindle 20 in the direction of the first work spindle 10 and L2 carries out the positioning perpendicular to the linear axes L1 and L3. The rotational axis R2, about which the second work spindle 20 can rotate, is here again in parallel to the rotational axis R1 of the first work spindle 10.

[0067] The advantage of this design now consists in that a machine table could fully be dispensed with and the fixation of the workpiece is such that it can also be subjected to a high and a partially very high speed to change from a milling processing to a turning processing in a minimum of time.

[0068] It should here be noted that in addition to the two work spindles a machine table can very well also be present or one of the two work spindles is a transportable work spindle which can be mounted/was mounted on the machine table. As a result, already existing machine tools might also be converted into a double spindle system.

[0069] In addition, FIG. 1 shows the two work spindles 10 and 20 in a coaxial alignment in relation to each other. This is not only relevant to the processing of the workpiece 12 but also to a handover of the workpiece 12 between the work spindles 10 and 20. Here, the workpiece 12, which is clamped in a clamping means 11 of the first work spindle 10, can be handed over to a clamping means 11 of the second work spindle 20 by positioning the second work spindle 20 in the plane of the linear axes L2 and L3 in relation to the first work spindle 10. If classical clamping means, such a chucks or jaw chucks, are used, the coaxial alignment of the two work spindles in relation to each other can be required in advance of the positioning movement of the work spindles.

[0070] FIG. 1 shows, in a concrete case, the coaxial alignment of the two work spindles 10 and 20 with a clamping means 11 and a workpiece 12 on the first work spindle 10 and a support means 21 with a tool 22 on the second work spindle 20.

[0071] FIG. 2 shows, by way of diagram, the machine tool 100 in a further embodiment with two wheel magazines 50 and 60 and two double grippers 30 and 40, wherein the work spindles 10 and 20 are mounted on the machine bed 80 of the machine tool 100, said spindles being positionable in relation to each other in accordance with the numerically controllable axes from FIG. 1.

[0072] The extension of the machine tool 100 now lies in the wheel magazines 50 and 60 for storing and placing down tool-carrying support means and non-tool-carrying support means 21 and workpiece-carrying clamping means 11 and non-workpiece-carrying clamping means 11. In addition, the machine tool 100 differs in that it is equipped with double grippers 30 and 40 as manipulators to change and transport the clamping and support means 11 and 21 between the wheel magazines 50 and 60 and the work spindles 10 and 20 in a suitable way.

[0073] This relevantly favors a largely automated processing procedure of workpieces 12 since e.g. the blank of the workpiece 12 can be placed down in one of the wheel magazines 50 and 60 or can be removed from one of the wheel magazines 50 and 60. In addition, it is, of course, also possible to supply the finished workpiece 12 to the wheel magazines 50 and 60 again or to remove it therefrom. The intermediate steps in the processing of the corresponding workpiece 12 might be fully automated and in the ideal case would only require to be monitored but would not require any manual intervention by the skilled worker or the machine operator.

[0074] It is here noted that the double grippers 30 and 40 are not limited to interact in each case with only a single spindle 10 or 20 and/or a single wheel magazine 50 or 60. On the contrary, the machine tool 100 can be designed e.g. in such a way that the double grippers 30 and 40 can provide the two double spindles 10 and 20 and the two wheel magazines 50 and 60 with corresponding clamping and support means 11 and 21.

[0075] A further advantage in the illustrated design of the machine tool 100 is the selection of the magazines as wheel magazines 50 and 60. They are able to store tools 22 and workpieces 12 of various sizes by the clamping or support means 11 and 21 and to always take them by means of a rotary motion to the same handover position at which a double gripper 30 or 40 or another tool or workpiece changer can receive the corresponding clamping or support means 11 and 21. The major advantage e.g. in comparison with shelf storage areas is that an additional supply device can be dispensed with which first removes the corresponding clamping or support means 11 or 21 from the shelf storage area and takes it to the handover position of the double gripper 30 or 40, which receives the corresponding means and supplies it to one of the work spindles 10 or 20.

[0076] FIG. 3 shows, by way of diagram, the machine tool 100 with two wheel magazines 50 and 60 and two double grippers 30 and 40 in a basic position of the work spindles 10 and 20.

[0077] The basic position here shown is simultaneously the position of the work spindles 10 and 20 when they interact with the double grippers 30 and 40 and a change of the clamping or support means 11 or 21 takes place at the corresponding work spindle 10 or 20.

[0078] It is an advantage if, in the illustrated basic position of the work spindles 10 and 20, the clamping and support means 11 and 21 which are to be introduced and which are stored in the magazines 50 and 60, are positioned at the handover position from magazine to double gripper in parallel to the clamping and support means 11 and 21, which are removed by the double grippers 30 and 40 from the spindle heads of the work spindles 10 and 20. This promotes a particularly fast change of the clamping and support means 11 and 21 since the double grippers 30 and 40 have to travel shorter travels to correspondingly remove the clamping or support means 11 and 21 from the magazines 50 and 60 and to supply them to the work spindles 10 and 20 or remove them from the work spindles 10 and 20 and supply them to the magazines 50 and 60.

[0079] It is also an advantage if the clamping and support means 11 and 21 which are to be introduced and which are stored in the magazines 50 and 60 are disposed at the handover position of magazine to double gripper and, in addition, lie in the same horizontal plane in which the clamping and support means 11 and 21 are disposed when they are removed by the double grippers 30 and 40 from the spindle heads of the work spindles 10 and 20. As a result, further travels of the double grippers 30 and 40 can be dispensed with and the process of supplying and/or changing the clamping and support means 11 and 21 can be carried out more rapidly.

[0080] FIG. 4 shows, by way of diagram, the handover of a workpiece 12 between a first spindle 10 and a second spindle 20 according to an embodiment of the method according to the invention.

[0081] Partial image a) shows that the first work spindle 10 holds a clamping means 11a (in this example an internal clamping means) that carries a workpiece 12 which is held on a second side 12b by the clamping means 11a. Furthermore, the second work spindle 20 is shown which holds a support means 21b with a tool 22b.

[0082] This can be a situation in which the tool 22b processes or has processed the workpiece 12 on a first side 12a.

[0083] Partial image b) now shows how the support means 21b was exchanged with the tool 22b on the second work spindle 20 and that a clamping means 11b was introduced in exchange (in this example an external clamping means). Here, the clamping means 11b holds the workpiece 12 on the first side 12a.

[0084] For the sake of completeness, it should be noted that holding the workpiece 12 on the first side 12a in the example as shown is only possible since the work spindles 10 and 20 have adopted a coaxial alignment in relation to each other in advance and the work spindles 10 and 20 were positioned in relation to each other along the common spindle axis direction.

[0085] Partial image c) now shows that the clamping means 11a was exchanged at the first work spindle with a support means 21a with tool 22a and the second side 12b of the workpiece 12 can now be processed with the tool 22a.

[0086] The illustrated and described handover process shall clarify how flexible the interaction between the two work spindles 10 and 20 can be to be able to process a workpiece 12 from all sides without the workpiece 12 having to be re-clamped manually with the known drawbacks.

[0087] FIG. 5 shows a flow diagram of an embodiment of the method according to the invention. FIG. 4 shall additionally be considered as a support for the description of the method.

[0088] In step S102, the workpiece 12 is clamped on a second side 12b in a clamping means 11a, which is mounted on a first work spindle 10. Here, the clamping means can be e.g. an internal clamping means (as shown in FIG. 4).

[0089] In the next step S103, a tool 22b is received in a support means 21b, which is mounted on a second work spindle 20. A milling tool, e.g. a shank cutter, can be used as an example of a tool 22b (as shown in FIG. 4).

[0090] In the following step S104, a first side 12a of the workpiece 12 is now processed by means of the tool 22b according to an NC program. Here, further sides of the workpiece 12 can also be processed, such as the lateral surface of the workpiece 12, which is disposed between the first side 12a and the second side 12b.

[0091] After the processing of the first side 12a of the workpiece 12 by the tool 22b, the support means 21b is exchanged, in step S105, with the tool 22b of the second work spindle 20 and a non-workpiece-carrying clamping means 11b is introduced e.g. by means of a manipulator, which is designed e.g. as a double gripper. Here, e.g. an external clamping means (as shown in FIG. 4) can be used.

[0092] As a result of the introduction of the clamping means 11b, the workpiece 12 can now be held basically by the clamping means 11b. However, in order to supply the workpiece 12 to the clamping means 11b, the two work spindles 10 and 20 have to be coaxially aligned in relation to each other in step S106. This is an extremely important step since a handover of the workpiece 12 is only possible to a limited extent without the coaxial alignment of the work spindles 10 and 20 in the example shown in FIG. 4.

[0093] For example, an additional supply device/handover device can alternatively be provided between the work spindles 10 and 20, which compensates for a non-coaxial alignment of the work spindles 10 and 20. However, a possible additional supply device/handover device shall be discussed later.

[0094] After the coaxial alignment, the workpiece 12 can be handed over from the workpiece-carrying clamping means 11a of the first work spindle 10 to the non-workpiece-carrying clamping means 11b of the second work spindle 20 in the following step S107, in which the work spindles 10 and 20 are positioned in relation to each other along their common, coaxially aligned spindle axis direction.

[0095] Then, the clamping means 11a of the first work spindle 10 can be retracted and exchanged in step S108. A support means 21a with a tool 22a (e.g. again a shank cutter or the like) can be introduced instead, as shown in FIG. 4.

[0096] Then, in a subsequent step, S109, the second side 12b of the workpiece 12, which is opposite the already processed first side 12a of the workpiece 12, can be processed according to the NC program with the introduced tool 22a of the first work spindle 10.

[0097] Since it is possible to hand over a workpiece 12 inside the machine tool 100 from one work spindle to the next, processing procedures can largely be processed in fully automatic fashion. Furthermore, it is extremely advantageous that all sides of a workpiece 12 can be processed in a single processing procedure without the workpiece 12 in the machine tool 100 having to be re-clamped manually by a skilled worker or machine operator. This saves time and reference points of the machine tool 100 on the workpiece 12 are not lost, such that it is not necessary to set up the machine tool 100 again.

[0098] The method can be extended to the effect that even before the step S106 (coaxial alignment of the work spindles 10 and 20 in relation to one another) the work spindles 10 and 20 adopt a basic position in which the spindle axes of the work spindles 10 and 20 lie in a plane, as shown e.g. in FIG. 3. Here, the basic position as shown is simultaneously the position in which the work spindles 10 and 20 can interact with the manipulators or double grippers 30 and 40.

[0099] The work spindles 10 and 20 can then be rotated out of the basic position by a rotary motion about a respective rotational axis, which are perpendicular to the plane, up to a coaxial alignment of the spindle axes. Following this, the method could then be continued with step S106.

[0100] The workpiece 12 can preferably be handed over from the first work spindle 10 to the second work spindle 20 in the method in such a way that during the handover the two work spindles 10 and 20 are simultaneously in contact with the workpiece 12, as shown in FIG. 4 by way of example. This would render an additional supply device/handover device superfluous.

[0101] However, the method is not limited thereto. The method can rather be extended to the effect that an additional supply device/handover device, e.g. an additional manipulator/double gripper, is provided for the handover of the workpiece 12 from the first work spindle 10 to the second work spindle 20. The additional supply device/handover device might be designed in such a way that it compensates for a possible non-coaxial alignment of the work spindles 10 and 20 in relation to one another when the workpiece 12 is handed over from one work spindle to the other.

[0102] However, it can also be an advantage for a manipulator or double gripper 30 or 40 (see e.g. FIGS. 2 and 3) already present in the machine tool 100 to be designed in such a way that in addition to the interaction of magazine 50 or 60 and work spindle 10 or 20 it can also operate between the two work spindles 10 and 20.

[0103] This would also make an additional supply device/handover device superfluous and increase the flexibility of the machine tool 100.

[0104] Examples or embodiments of the present invention and the advantages thereof have been described above in detail with reference to the enclosed drawings

LIST OF REFERENCE SIGNS

[0105] 10 first work spindle [0106] 11, 11a, 11b clamping means [0107] 12 workpiece [0108] 12a first side of the workpiece [0109] 12b second side of the workpiece [0110] 20 second work spindle [0111] 21, 21a, 21b support means [0112] 22, 22a, 22b tool [0113] 30, 40 manipulator/double gripper [0114] 50, 60 magazine/wheel magazine [0115] 80 machine bed [0116] 100 machine tool