Machine tool

Abstract

To provide a machine tool capable of working a workpiece to a complicated shape by an easier manner.SOLUTION: A machine tool 1 comprises: a first main spindle unit 10 and a second main spindle unit 20 which rotate a workpiece W while holding the workpiece W; a first main spindle displacing mechanism 15 which displaces the first main spindle unit 10 in Z-axis direction; a second main spindle displacing mechanism 25 which displaces the second main spindle unit 20 in X-axis direction and the Z-axis direction; a guide bush attachment unit 17b to which a guide bush 18 can be attached; a blade stand 30 which holds a tool 35; a blade stand displacing mechanism 32 which displaces the blade stand 30 in Y-axis direction; a tool main shaft unit 50 which holds tools 70, 80; a tool displacing mechanism 42 which displaces a tool main spindle unit 50 in the X-axis direction, the Y-axis direction and the Z-axis direction; a tool revolving mechanism 45 which revolves the tools 70, 80 together with the tool main spindle 50; and a tool housing and exchanging system 60 which exchanges housing tool 78 to be housed and tools 70, 80 to be attached to the tool spindle unit 50.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a machine tool. [Background technology]

[0002] For example, the machining center described in Patent Document 1 includes a tool magazine that holds multiple tools such as drills, end mills, milling cutters, etc., and a tool spindle that can automatically exchange tools between the tool magazine and rotates the attached tools to machine a workpiece. Moreover, for example, the lathe described in Patent Document 2 includes a spindle that imparts a rotational motion to a workpiece, and a tool table on which various tools for machining the workpiece are mounted. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-37581 [Patent Document 2] JP 2011-693 A Summary of the Invention [Problem to be solved by the invention]

[0004] When machining a workpiece into a complex shape using both the machining center described in Patent Document 1 and the lathe described in Patent Document 2, it is necessary to separate the machining process between the machining center and the lathe, and then to switch the workpiece between the machining center and the lathe during machining, which makes machining of the workpiece time-consuming.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a machine tool that can more easily machine a workpiece into a complex shape. [Means for solving the problem]

[0006] In order to achieve the above object, a machine tool according to the present invention includes a first spindle unit that holds and rotates a workpiece, a second spindle unit that is configured to be able to receive the workpiece from the first spindle unit and that holds and rotates the workpiece, a first spindle movement mechanism that moves the first spindle unit in a first direction along the rotation axis of the workpiece, a second spindle movement mechanism that moves the second spindle unit in the first direction and a second direction intersecting the first direction, a guide bush attachment portion to which a guide bush that supports the workpiece held by the first spindle unit can be attached, and a machine tool that machines the workpiece held by the second spindle unit. the tool spindle unit holds a second tool for machining the workpiece held by the first spindle unit or the second spindle unit; a tool moving mechanism for moving the tool spindle unit in the first direction, the second direction, and the third direction; a tool rotating mechanism for rotating the second tool together with the tool spindle unit about a rotating axis; and a tool storage and exchange system for storing a plurality of stored tools and exchanging the second tool held by the tool spindle unit with any one of the stored stored tools. At least one of the tool rest moving mechanism and the tool rest is located below the guide bush attached to the guide bush attachment portion in the second direction. do. Effect of the Invention

[0007] According to the present invention, a workpiece can be machined into a complex shape more easily using a machine tool. [Brief description of the drawings]

[0008] [Figure 1] 1 is a front view of a machine tool according to an embodiment of the present invention; [Diagram 2] 1 is a plan view of a machine tool according to an embodiment of the present invention; [Diagram 3] FIG. 1 is a front view of a tool storage and exchange system and a tool spindle unit according to an embodiment of the present invention. [Figure 4] FIG. 1 is a plan view of a tool storage and exchange system and a tool spindle unit according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a plan view of a tool rest and a tool rest moving mechanism according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a machine tool according to an embodiment of the present invention will be described with reference to the drawings. As shown in Figures 1 and 2, machine tool 1, which is a turning center, comprises a bed S which is a base for the entire machine tool 1, a first spindle unit 10 having a first spindle 11, a second spindle unit 20 having a second spindle 21, a first spindle moving mechanism 15, a second spindle moving mechanism 25, a tool rest 30, a tool rest moving mechanism 32, a tool spindle unit 50, a tool moving mechanism 42, a tool rotating mechanism 45, a guide bush 18, a support member 13, an installation base 17, a tool storage and exchange system 60, and a control unit 300. In the following, the axial direction along the rotation axes of the first main shaft 11 and the second main shaft 21 is defined as the Z-axis direction, the height direction perpendicular to the Z-axis direction is defined as the X-axis direction, and the depth direction perpendicular to the X-axis and Z-axis directions is defined as the Y-axis direction.

[0010] As shown in Fig. 1, the first spindle unit 10 holds and rotates a workpiece W. Specifically, the first spindle unit 10 includes a first spindle 11 and a first spindle stock 12 that rotatably supports the first spindle 11. The first spindle 11 holds one end of the workpiece W. A workpiece rotating motor (not shown) that rotates the first spindle 11 is built into the first spindle stock 12. The first spindle moving mechanism 15 moves the first spindle unit 10 in the Z-axis direction. The first spindle moving mechanism 15 is installed on the upper surface of an installation table 17. The installation table 17 is provided on the upper surface of the bed S.

[0011] The guide bush 18 supports the tip side of the workpiece W held by the first spindle 11. The guide bush 18 is located between the first spindle unit 10 and the machining point of the workpiece W, and is provided on a guide bush attachment portion 17b. The guide bush attachment portion 17b is located on the side of the upper surface of the installation table 17 that is closer to the second spindle 21. The guide bush 18 is detachable from the guide bush attachment portion 17b. The guide bush 18 supports the workpiece W, thereby suppressing bending and vibration of the workpiece W during machining. When the workpiece W is a long workpiece, the guide bush 18 is attached to the guide bush attachment portion 17b, and when the workpiece W is a short workpiece, the guide bush 18 is removed from the guide bush attachment portion 17b.

[0012] 1 and 2, the second spindle unit 20 is provided at a position facing the first spindle unit 10 in the Z-axis direction. The second spindle unit 20 includes a second spindle 21 that holds the other end of the workpiece W, and a second spindle stock 22 that rotatably supports the second spindle 21. A workpiece rotating motor (not shown) that rotates the second spindle 21 is built into the second spindle stock 22.

[0013] 1, the second spindle moving mechanism 25 includes an X moving mechanism 25X that moves the second spindle unit 20 in the X-axis direction (X2-axis direction) and a Z moving mechanism 25Z that moves the second spindle unit 20 in the Z-axis direction (Z2-axis direction). The second spindle unit 20 is configured to be immovable in the Y-axis direction.

[0014] As shown in FIG. 2, the tool moving mechanism 42 includes a Y moving mechanism 42Y that moves the tool spindle unit 50 in the Y axis direction (Y1 axis direction), a Z moving mechanism 42Z that moves the tool spindle unit 50 in the Z axis direction (Z1 axis direction), and as shown in FIG. 1, an X moving mechanism 42X that moves the tool spindle unit 50 in the X axis direction (X1 axis direction).

[0015] 2, slide table 42S, which moves in the Z-axis direction of Z movement mechanism 42Z, moves along a pair of rails 29a extending in the Z-axis direction on bed S. Slide table 25S, which moves in the Z-axis direction of Z movement mechanism 25Z, moves along a pair of rails 29b extending in the Z-axis direction on bed S. Rails 29a and 29b are aligned in the Z-axis direction, and the pair of rails 29a is set to have a wider gap between them than the pair of rails 29b. Motor 42M, which is part of Z movement mechanism 42Z, is installed next to the pair of rails 29b in the Y-axis direction. The X-movement mechanism 25X, 42X, the Y-movement mechanism 42Y, and the Z-movement mechanism 25Z, 42Z each have a motor, a ball screw, and a nut, and are configured to convert the rotational force of the motor into linear motion by the ball screw and the nut, thereby moving the corresponding second spindle unit 20 or tool spindle unit 50 linearly.

[0016] 1, the tool turning mechanism 45 turns the tools 70, 80 attached to the tool spindle unit 50 in the B-axis direction by rotating the tool spindle unit 50. The B-axis direction is a rotation direction about a turning axis Ob along the Y-axis direction.

[0017] As shown in FIG. 1, the tool spindle unit 50 is, for example, a tool spindle, and is located above the workpiece W held by the first spindle 11 or the second spindle 21. The tool spindle unit 50 includes a clamp portion 51 configured to allow a fixed tool 70 or a rotating tool 80 to be attached thereto. The clamp portion 51 is located on the tip side of the tool spindle unit 50, and grips the shank portions 71, 81 of the tools 70, 80. The tool spindle unit 50 supports the fixed tool 70 in a fixed manner so that it cannot rotate about its axis, and supports the rotating tool 80 so that it can rotate about its axis. The fixed tool 70 is, for example, a turning tool that performs turning processing. The rotating tool 80 is, for example, a milling tool that performs milling processing. The tool spindle unit 50 is located between the first spindle unit 10 and the second spindle unit 20 in the Z-axis direction. The tool spindle unit 50 machines the workpiece W held by the first spindle 11 or the workpiece W held by the second spindle 21 with the attached fixed tool 70 or rotating tool 80 .

[0018] 1 and 5, the tool rest 30 is configured so that a plurality of tools 35 for machining the workpiece W held by the second spindle 21 can be attached to it. The plurality of tools 35 can be attached to the tool rest 30 so as to be aligned in each of the X-axis direction and the Y-axis direction. The tool rest 30 is installed on the upper surface of the bed S, and is provided at a height that allows the workpiece W held by the first spindle unit 10 and fed in the Z-axis direction to pass above it.

[0019] 1, the tool rest 30 is located below the guide bush 18. The tool rest movement mechanism 32 is located on the upper surface of the bed S, in a recess 17a formed in the installation table 17. The recess 17a is formed below the guide bush attachment portion 17b of the installation table 17. The multiple tools 35 include rotating tools such as drills or end mills that rotate to machine the workpiece W, and fixed tools. Each tool 35 is attached to the tool rest 30 while extending along the Z-axis direction. The cutting edge of each tool 35 faces in the Z-axis direction away from the first spindle unit 10. The tool rest 30 is equipped with a drive mechanism (not shown) that applies a rotational force to the attached rotating tool. A workpiece discharge means (not shown), such as a work conveyor, unloader, or chute box, is provided near the tool rest 30.

[0020] 5, the tool rest moving mechanism 32 moves the tool rest 30 in the Y-axis direction. When the tool rest 30 moves in the Y-axis direction, it becomes possible to bring one of the multiple tools 35 arranged in the Y-axis direction into contact with the workpiece W held by the second spindle 21. Like the Y-movement mechanism 42Y, each tool rest moving mechanism 32 has a motor, a ball screw, and a nut. The tool rest 30 is configured to be immovable in the X-axis and Z-axis directions.

[0021] As shown in FIGS. 3 and 4, the tool storage and exchange system 60 stores a plurality of stored tools 78 and exchanges a selected one of the plurality of stored tools 78 with the tools 70, 80 attached to the tool spindle unit 50. The tool storage and exchange system 60 includes a tool storage unit 61 that stores a plurality of stored tools 78 , and a tool exchange section 65 that exchanges tools 70 , 80 between the tool storage unit 61 and the tool spindle unit 50 .

[0022] The tool storage unit 61 includes a plurality of tool magazines 63 a and 63 b and a drive unit 62 . The tool magazines 63a, 63b are substantially annular and supported rotatably about a rotation axis C extending along the X-axis direction. A plurality of tool magazines 63a, 63b (two in this example) are arranged on the rotation axis C. As shown in FIG. 4, each of the tool magazines 63a and 63b includes a plurality of tool gripping parts 63c. The tool gripping parts 63c are located on the outer periphery of the tool magazines 63a and 63b, and are arranged to be aligned in the rotation direction of the tool magazines 63a and 63b. Each of the tool magazines 63a and 63b can accommodate a plurality of stored tools 78, 20 in this example. The stored tools 78 are fixed tools 70 or rotating tools 80. Each of the tool gripping parts 63c has a U-shaped groove that opens toward the radial outside of the tool magazines 63a and 63b, and holds the stored tools 78 by fitting the shank parts 71 and 81 (see FIG. 3) of the stored tools 78 into the groove. The tool gripping parts 63c hold the stored tools 78 in a direction along the X-axis direction. The driving unit 62 has, for example, a motor, and rotates the tool magazines 63a and 63b about a rotation axis C.

[0023] 3 and 4, the tool exchange unit 65 is provided at a position closer to the tool spindle unit 50 than the tool storage unit 61. The tool exchange unit 65 includes an arm unit 66, a transport unit 67 that transports tools 70, 78, 80, transport unit moving mechanisms 68X, 68Z that move the transport unit 67, and an arm moving mechanism (not shown) that moves the arm unit 66.

[0024] The transfer unit moving mechanism 68X moves the transfer unit 67 in the X-axis direction so that the transfer unit 67 can move between the two tool magazines 63a, 63b. The transfer unit moving mechanism 68Z moves the transfer unit 67 in the Z-axis direction. Each of the transfer unit moving mechanisms 68X, 68Z has a motor, a ball screw, and a nut, similar to the X-moving mechanisms 25X, 42X, etc. The transport unit 67 is switched between a clamped state in which it grips the shanks 71, 81 of the tools 70, 78, 80 and an unclamped state in which it releases the grip. The transport unit 67 clamps the shanks 71, 81 of the tools 70, 78, 80 from above in a position extending along the X-axis direction. An arm movement mechanism (not shown) moves the arm unit 66 in the X-axis direction.

[0025] As shown in FIG. 3, the arm unit 66 includes an arm portion 66a, an arm support portion 66b, and an arm rotation drive portion (not shown). The arm support portion 66b supports the arm portion 66a so that it can rotate around a rotation axis 66o. The arm rotation drive portion (not shown) has a motor and rotates the arm portion 66a. The arm portion 66a has a generally rectangular plate shape extending in a direction perpendicular to the rotation axis 66o. The rotation axis 66o runs along the thickness direction and the X-axis direction of the arm portion 66a and passes through the center position of the arm portion 66a. As shown in Fig. 4, a first holding portion 66c for holding the shank portions 71, 81 (see Fig. 3) of the tools 70, 80 is formed at one end in the longitudinal direction of the arm portion 66a, and a second holding portion 66d for holding the shank portions 71, 81 of the tools 70, 80 is formed at the other end. The first holding portion 66c and the second holding portion 66d have grooves into which the shank portions 71, 81 of the tools 70, 80 fit as the arm portion 66a rotates. The arm portion 66a rotates about a rotation axis 66o between an initial position indicated by a solid line in Fig. 4 and a holding position indicated by a two-dot chain line in Fig. 4 by an arm rotation drive portion (not shown). When the arm portion 66a is in the initial position, the longitudinal direction of the arm portion 66a is aligned along the Y-axis direction. When the arm portion 66a is in the holding position, the longitudinal direction of the arm portion 66a is aligned along the Z-axis direction.

[0026] 1, the tool storage and exchange system 60 is supported by a support member 13 and is located above the first spindle unit 10. In more detail, the tool magazines 63a and 63b are located above the first spindle stock 12, and the arm unit 66 is located above the guide bush 18.

[0027] 1, the control unit 300 controls the first spindle unit 10, the second spindle unit 20, the first spindle movement mechanism 15, the second spindle movement mechanism 25, the tool rest movement mechanism 32, the tool spindle unit 50, the tool movement mechanism 42, the tool turning mechanism 45, and the tool storage and exchange system 60. The control unit 300 includes, for example, a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) that stores a program that defines the procedure of processing by the CPU, and the like.

[0028] Next, a description will be given of the machining process executed by the control unit 300. The control unit 300 executes this machining process according to an NC (Numerical Control) program created in advance. The workpiece W to be machined in this machining process is a thin and cylindrical bar material, and is a long workpiece that is preferably supported by a guide bush 18 during machining.

[0029] As shown in FIG. 1, the control unit 300 supplies a workpiece W from the rear of the first spindle unit 10 by a workpiece supply unit (not shown). Then, the control unit 300 performs a first machining process using the fixed tool 70 or the rotating tool 80 attached to the tool spindle unit 50 while supporting the workpiece W held by the first spindle 11 with the guide bush 18. In this first machining, for example, when a fixed tool 70 is attached to the tool spindle unit 50, a turning process may be performed using the fixed tool 70 to cut the outer peripheral surface of the workpiece W. In this turning process, the control unit 300 feeds the fixed tool 70 in the Z-axis direction relative to the workpiece W via at least one of the first spindle moving mechanism 15 and the tool moving mechanism 42 while rotating the first spindle 11 together with the workpiece W, with the cutting edge of the fixed tool 70 facing the workpiece W via the tool turning mechanism 45. In addition, in this first machining, for example, when a rotating tool 80 is attached to the tool spindle unit 50, milling of the workpiece W may be performed using the rotating tool 80. In this milling, the control unit 300 moves the rotating tool 80 via the tool moving mechanism 42 while rotating the rotating tool 80 via the tool spindle unit 50 with the axial rotation of the first spindle 11 stopped. In addition, milling may be performed on the outer circumferential surface and end surface of the workpiece W with the rotating tool 80 tilted in the B-axis direction with respect to the X1-axis direction via the tool turning mechanism 45. This allows various machining operations to be performed on the workpiece W.

[0030] Next, the control unit 300 moves the second spindle 21 via the second spindle moving mechanism 25 to a position facing the guide bush 18, and the second spindle 21 holds the workpiece W. At this time, the second spindle 21 is moved in the Z-axis direction toward the first spindle 11 so as to pass above the tool rest 30. The control unit 300 rotates the workpiece W while holding both ends of the workpiece W with the first spindle 11 and the second spindle 21, and cuts the workpiece W with a cut-off tool serving as a fixed tool 70 attached to the tool spindle unit 50. In this way, the workpiece W is transferred from the first spindle 11 to the second spindle 21. The workpiece W may be transferred from the first spindle 11 to the second spindle 21 without being cut.

[0031] Then, the control unit 300 performs a second machining process on the workpiece W held by the second spindle 21 using the tool 35 attached to the tool rest 30 or the tools 70 and 80 attached to the tool spindle unit 50 . In this second machining, for example, similar to the first machining described above, turning or milling may be performed on the workpiece W held by the second spindle 21 using a fixed tool 70 or a rotating tool 80 attached to the tool spindle unit 50. In addition, in this second machining, for example, while rotating the tool 35 held by the tool rest 30, the cutting edge of the tool 35 is brought into contact with the workpiece W held by the second spindle 21, and the tool 35 is moved relative to the workpiece W via the Z movement mechanism 25Z to perform milling. During this second machining, the tool rest 30 is moved in the Y-axis direction by the tool rest movement mechanism 32, so that one of the multiple tools 35 arranged in the Y-axis direction can be selectively used to machine the workpiece W. Since the tool 35 is located below the position where the second spindle 21 receives the workpiece W from the first spindle 11, the second spindle 21 can smoothly transition from the operation of receiving the workpiece W to the second machining using the tool 35.

[0032] The control unit 300 may perform the first machining on the workpiece W held by the first spindle 11 using the fixed tool 70 or the rotating tool 80 of the tool spindle unit 50, simultaneously with the second machining on the workpiece W held by the second spindle 21 using the tool 35 of the tool rest 30. In this way, by overlapping the time of the first machining and the time of the second machining, it is possible to shorten the cycle time, which is the time required to machine one workpiece.

[0033] When the second machining is completed, the control unit 300 moves the workpiece W after the second machining to a workpiece discharge position Po via the second spindle moving mechanism 25 and discharges it to the outside in cooperation with a workpiece discharge means (not shown). The workpiece discharge position Po is set near the tool rest 30 and at a position where the workpiece W held by the second spindle 21 is retracted in the Z-axis direction from the tool 35 of the tool rest 30. Therefore, after the second machining using the tool 35 of the tool rest 30, the workpiece W can be smoothly discharged to the outside via the workpiece discharge means. This completes the processing. This processing is repeatedly performed every time a workpiece W is supplied. In addition, in the first processing or the second processing, the control unit 300 may perform only one of the turning processing and the milling processing, or may perform both the turning processing and the milling processing in a predetermined order.

[0034] Next, a description will be given of a tool changing process for changing the type of the tools 70, 80 attached to the tool spindle unit 50. This tool changing process is executed during the above-mentioned machining process, for example, during the above-mentioned second machining process or after the machining process is completed. In the following, an example will be described in which the tool attached to the tool spindle unit 50 is replaced from the rotating tool 80 to the fixed tool 70, but the type of tool to be replaced is not limited to this.

[0035] 3, the control unit 300 rotates the tool magazines 63a, 63b via the drive unit 62 to move the fixed tool 70 to be used among the multiple stored tools 78 stored in the tool magazine 63a to the stored tool discharge position Pa. The stored tool discharge position Pa is a position where the transport unit 67 transfers tools between the tool magazines 63a, 63b, and is set to a portion of the tool magazines 63a, 63b closest to the tool spindle unit 50 in this example. The control unit 300 lowers the transfer unit 67 in the X-axis direction via the transfer unit moving mechanisms 68X, 68Z, as shown by the arrow J1 in Fig. 3, and clamps the shank portion 71 of the fixed tool 70 at the transfer unit 67. Next, the control unit 300 retreats the transfer unit 67 from the tool magazine 63a in the Z-axis direction via the transfer unit moving mechanism 68Z, as shown by the arrow J2 in Fig. 3, and moves the transfer unit 67 from the stored tool discharge position Pa to the tool transfer position P1. As a result, the transfer unit 67 takes out the fixed tool 70 from the tool gripping portion 63c of the tool magazine 63a. In this embodiment, the transport unit 67 takes out the stored tools 78 stored in the tool magazine 63a. However, this is not limiting, and the transport unit 67 may take out the stored tools 78 stored in the tool magazine 63b.

[0036] Further, the control unit 300 moves the rotating tool 80 attached to the tool spindle unit 50 to the tool changing position P2 via the tool moving mechanism 42 (see FIG. 1). The tool changing position P2 is set at a position separated from the tool transfer position P1 in the Z-axis direction by the length of the arm portion 66a. Then, the control unit 300 rotates the arm portion 66a counterclockwise as viewed from above from the initial position shown by the solid line in FIG. 4 to the holding position shown by the two-dot chain line in FIG. 4 around the rotation axis 66o via the arm rotation drive unit (not shown). As a result, as shown in FIG. 3, the shank portion 81 of the rotating tool 80 attached to the tool spindle unit 50 is held by the first holding portion 66c of the arm portion 66a, and the shank portion 71 of the fixed tool 70 attached to the transport unit 67 is held by the second holding portion 66d of the arm portion 66a. In this state, the control unit 300 switches the tool spindle unit 50 and the transport unit 67 from the clamped state to the unclamped state. Then, the control unit 300, via the arm moving mechanism (not shown), lowers the arm unit 66a so that the arm unit 66a pulls out the rotating tool 80 and the fixed tool 70 from the tool spindle unit 50 and the transport unit 67, as shown by arrow J3 in FIG. 3.

[0037] Next, the control unit 300 rotates the arm unit 66a through 180° about the rotation axis 66o as indicated by the arrow J4 in Fig. 3 via the arm rotation drive unit (not shown). As a result, the rotating tool 80 held by the first holding unit 66c of the arm unit 66a is positioned opposite the transfer unit 67, and the fixed tool 70 held by the second holding unit 66d of the arm unit 66a is positioned opposite the clamp unit 51 of the tool spindle unit 50.

[0038] Next, the control unit 300 raises the arm unit 66a via the arm moving mechanism (not shown) as indicated by arrow J5 in Fig. 3, thereby inserting the shank portion 81 of the rotating tool 80 into the transport unit 67 and inserting the shank portion 71 of the fixed tool 70 into the clamp unit 51 of the tool spindle unit 50. Then, the control unit 300 switches the tool spindle unit 50 and the transport unit 67 from the unclamped state to the clamped state. This completes the attachment of the fixed tool 70 to the tool spindle unit 50 and the attachment of the rotating tool 80 to the transport unit 67.

[0039] Next, the control unit 300 rotates the arm unit 66a about the rotation axis 66o from the holding position shown by the two-dot chain line in Fig. 4 to the initial position shown by the solid line in Fig. 4 via the arm rotation drive unit (not shown). In addition, the control unit 300 returns the rotating tool 80 held by the transfer unit 67 to the corresponding tool gripping unit 63c of the tool magazines 63a, 63b by moving the transfer unit 67 via the transfer unit moving mechanisms 68X, 68Z. Simultaneously with this tool return, the tool spindle unit 50 may perform an operation for machining the workpiece W. This completes the tool replacement process.

[0040] (effect) According to the embodiment described above, the following effects are achieved. (1) The machine tool 1 includes a first spindle unit 10 that holds and rotates a workpiece W, a second spindle unit 20 that is configured to be able to receive the workpiece W from the first spindle unit 10 and that holds and rotates the workpiece W, a first spindle movement mechanism 15 that moves the first spindle unit 10 in a Z-axis direction (first direction) along the rotation axis of the workpiece W, a second spindle movement mechanism 25 that moves the second spindle unit 20 in an X-axis direction (second direction) along the Z-axis direction and a height direction intersecting the Z-axis direction, a guide bush attachment portion 17b to which a guide bush 18 that supports the workpiece W held by the first spindle unit 10 can be attached, and a tool 35 that is an example of a first tool for machining the workpiece W held by the second spindle unit 20 is attached. The tool spindle unit 50 includes a tool rest 30, a tool rest movement mechanism 32 that moves the tool rest 30 in a Y-axis direction (third direction) that is along a depth direction intersecting both the X-axis direction and the Z-axis direction, a tool spindle unit 50 that holds tools 70, 80 which are an example of a second tool for machining a workpiece W held by the first spindle unit 10 or the second spindle unit 20, a tool movement mechanism 42 that moves the tool spindle unit 50 in the X-axis, Y-axis and Z-axis directions, a tool rotation mechanism 45 that rotates the tools 70, 80 together with the tool spindle unit 50 about a rotation axis Ob, and a tool storage and exchange system 60 that stores a plurality of stored tools 78 and exchanges the tool 70, 80 attached to the tool spindle unit 50 with any one of the plurality of stored tools 78. According to this configuration, with one machine tool 1, it is possible to machine the workpiece W held by the first spindle unit 10 or the second spindle unit 20 with the tools 70, 80 held by the tool spindle unit 50, and to machine the workpiece W held by the second spindle unit 20 with the tool 35 held by the tool rest 30. In particular, the tool spindle unit 50 is capable of machining after changing the orientation of the tools 70, 80 by the tool turning mechanism 45. Therefore, since a variety of machining is possible with one machine tool 1, it is possible to more easily machine the workpiece W into a complex shape without the need to divide the machining process or change the workpiece W. In addition, the first spindle unit 10 is movable to feed the held workpiece W in the Z-axis direction, and the guide bush 18 is attachable to the guide bush attachment portion 17b. Therefore, the machine tool 1 is suitable for machining a long workpiece W, which is long in length, and can machine this long workpiece into a complex shape. Furthermore, the tool spindle unit 50 can use the attached tools 70, 80 to machine the workpiece W held by the first spindle unit 10, and can also machine the workpiece W held by the second spindle unit 20. In addition, the tool storage and exchange system 60 can exchange the type of tools 70, 80 held by the tool spindle unit 50. Therefore, the tool spindle unit 50 can perform both milling and turning. Furthermore, while the workpiece W held by the second spindle unit 20 is being machined by the tool 35 of the tool rest 30, another workpiece W held by the first spindle unit 10 can be machined by the tools 70, 80 of the tool spindle unit 50. This makes it possible to shorten the cycle time required to machine the workpiece W. Further, the workpiece W is supplied to the first spindle unit 10, and the first machining is performed on the workpiece W held by the first spindle unit 10 by the tools 70, 80. Then, the workpiece W after the first machining is transferred from the first spindle unit 10 to the second spindle unit 20. Next, the second machining is performed on the workpiece W held by the second spindle unit 20 by the tools 35, 70, 80, and the workpiece W is discharged to the outside using a workpiece discharge means (not shown) such as a workpiece conveyor or an unloader. In this way, the machine tool 1 can automatically complete the machining from the supply to the discharge of the workpiece W without human intervention. Furthermore, since there is no human intervention, it is possible to suppress installation defects of the workpiece W. Furthermore, by positioning the workpiece discharge position Po in the vicinity of the tool rest 30, the workpiece W can be quickly discharged to the outside after machining of the workpiece W by the second spindle unit 20 using the tool 35 is completed.

[0041] (2) The machine tool 1 is dedicated to machining a workpiece W formed from bar stock. This configuration allows the machine tool 1 to be compact. For example, the bar is formed in a long and thin cylindrical shape (diameter smaller than length). Therefore, the structure in which the first spindle 11 and the second spindle 21 hold the workpiece W can be made compact. For example, the diameter of the workpiece W is preferably about 40 mm or less. Furthermore, by attaching the guide bush 18 to the guide bush attachment portion 17b, a long workpiece can be machined. Furthermore, by removing the guide bush 18 from the guide bush attachment portion 17b, a short workpiece can be machined. Therefore, regardless of the length of the workpiece W, the workpiece W can be machined into a complex shape.

[0042] (3) The tool storage and exchange system 60 includes tool magazines 63a, 63b that store a plurality of stored tools 78 and are located above the first spindle unit 10, and a tool exchange unit 65 that exchanges one of the plurality of stored tools 78 stored in the tool magazines 63a, 63b with the tool 70, 80 attached to the tool spindle unit 50. According to this configuration, if the tool magazines 63a, 63b are provided in a location other than above the first spindle unit 10, additional space is required for the tool magazines 63a, 63b, but by providing the tool magazines 63a, 63b above the first spindle unit 10, this space is not required. Therefore, the machine tool 1 can be configured compactly. The tool replacement unit 65 also includes a transport unit 67 that transfers tools 70, 80 into and out of the tool magazines 63a, 63b, and an arm unit 66 that replaces a tool removed from the transport unit 67 with a tool attached to the tool spindle unit 50. In a comparative example, in a configuration in which tools are directly exchanged between the tool magazine and the tool spindle, after the tool spindle returns the tool to the tool magazine, the tool magazine needs to be indexed so that the desired tool is in a position where it can be attached to the tool spindle, and it takes time from the return of the tool to the attachment of the tool. In this regard, in the above configuration, the indexing operation of the tool magazine after the tool is returned is not necessary, so tools can be replaced quickly. Furthermore, the transfer section 67 can take in and out tools from the two-stage tool magazines 63a and 63b, which allows the number of tools that can be stored in the tool magazine to be increased.

[0043] (4) The second spindle unit 20 is configured to be immovable in the Y-axis direction. The tool rest 30 is configured to be able to mount a plurality of tools 35 aligned in the Y-axis direction. The machine tool 1 includes a control unit 300 that, when machining a workpiece W held by the second spindle unit 20, moves the tool rest 30 in the Y-axis direction via the tool rest movement mechanism 32, thereby bringing the workpiece W into contact with one of the plurality of tools 35 aligned in the Y-axis direction. According to this configuration, even if the second spindle unit 20 cannot move in the Y-axis direction, the tool rest 30 can move in the Y-axis direction, so that a plurality of tools 35 arranged in the Y-axis direction can be attached to the tool rest 30. Therefore, the number of tools 35 can be increased while making the tool rest 30 compact, and a variety of machining operations can be performed on the workpiece W. Furthermore, even if the tool rest 30 cannot move in the X-axis direction, the second spindle unit 20 can move in the X-axis direction, so that a plurality of tools 35 arranged in the X-axis direction can be attached to the tool rest 30. This makes it possible to increase the number of tools 35 while making the tool rest 30 compact, and to perform a variety of machining operations on the workpiece W. Furthermore, the configuration for moving the second spindle unit 20 in the Y-axis direction can be omitted, so that the second spindle moving mechanism 25 can be made lighter and its strength increased.

[0044] (5) The tool rest moving mechanism 32 is located below the guide bush 18 attached to the guide bush attachment portion 17b. This configuration allows for a compact configuration of the machine tool 1. In particular, since the tool rest 30 cannot move in the X-axis and Z-axis directions, the tool rest movement mechanism 32 can be configured to be compact enough to be housed below the guide bush 18.

[0045] The present disclosure is not limited to the above-described embodiments and drawings. Modifications (including deletion of components) can be made as appropriate within the scope of the present disclosure. An example of a modification will be described below.

[0046] (Modification) In the above embodiment, the tool magazines 63a, 63b are provided above the first spindle unit 10, but may be provided at other positions. For example, the tool magazines 63a, 63b may be provided at positions shifted in the Z-axis direction with respect to the first spindle unit 10, or may be provided below the first spindle unit 10. In the above embodiment, the workpiece W is formed of a bar material, but is not limited to this and may be in another shape such as a disk shape.

[0047] In the above embodiment, the tool post movement mechanism 32 is located below the guide bush 18, but this is not limiting, and only the tool post 30, or both the tool post movement mechanism 32 and the tool post 30 may be located below the guide bush 18. In addition, both the tool post movement mechanism 32 and the tool post 30 may be provided at a position other than below the guide bush 18.

[0048] In the above embodiment, the second spindle unit 20 is configured to be immovable in the Y-axis direction, but the present invention is not limited to this and may be configured to be movable in the Y-axis direction. Furthermore, although the tool rest 30 is configured so as to be immovable in the X-axis and Z-axis directions, it may be configured so as to be movable in at least one of the X-axis and Z-axis directions. [Explanation of symbols]

[0049] 1...machine tool, 10...first spindle unit, 11...first spindle, 12...first spindle stock, 13...support member, 15...first spindle movement mechanism, 17...installation base, 17a...recess, 17b...guide bush mounting portion, 18...guide bush, 20...second spindle unit, 21...second spindle, 22...second spindle stock, 25...second spindle movement mechanism, 25S, 42S...slide base, 25X, 42X...X movement mechanism, 25Z, 42Z...Z movement mechanism, 29a, 29b...rail, 30...tool rest, 32...tool rest movement mechanism, 35...tool, 42...tool movement mechanism, 42M...motor, 42Y...Y movement mechanism, 45...tool rotation mechanism, 50...tool spindle unit, 5 1...Clamping section, 60...Tool storage and exchange system, 61...Tool storage unit, 62...Drive section, 63a, 63b...Tool magazine, 63c...Tool gripping section, 65...Tool exchange section, 66...Arm unit, 66a...Arm section, 66b...Arm support section, 66c...First holding section, 66d...Second holding section, 67...Transport section, 68X, 68Z...Transport section moving mechanism, 70...Fixed tool, 71, 81...Shank section, 78...Stored tool, 80...Rotating tool, 300...Control section, C, 66o...Rotating axis, Ob...Swivel axis, P1...Tool transfer position, P2...Tool exchange position, Pa...Stored tool ejection position, Po...Work ejection position, S...Bed, W...Work

Claims

1. A first spindle unit that holds and rotates a workpiece; a second spindle unit configured to be able to receive the workpiece from the first spindle unit and to rotate the workpiece while holding it; a first spindle moving mechanism that moves the first spindle unit in a first direction along a rotation axis of the workpiece; a second spindle moving mechanism that moves the second spindle unit in the first direction and in a second direction intersecting the first direction; a guide bush attachment portion to which a guide bush for supporting the workpiece held by the first spindle unit can be attached; a tool rest that holds a first tool for machining the workpiece held by the second spindle unit; a tool rest moving mechanism that moves the tool rest in a third direction intersecting both the first direction and the second direction; a tool spindle unit that holds a second tool for machining the workpiece held by the first spindle unit or the second spindle unit; a tool moving mechanism that moves the tool spindle unit in the first direction, the second direction, and the third direction; a tool turning mechanism that turns the second tool together with the tool spindle unit around a turning axis; a tool storage and exchange system that stores a plurality of stored tools and exchanges any one of the stored tools with the second tool held by the tool spindle unit; at least one of the tool rest moving mechanism and the tool rest is located below the guide bush attached to the guide bush attachment portion in the second direction; Machine tools.

2. The machine tool is dedicated to machining the workpiece formed of bar stock; The machine tool according to claim 1.

3. The tool storage and exchange system includes: a tool magazine that accommodates the plurality of stored tools and is located above the first spindle unit along the second direction; a tool exchange unit that exchanges any one of the plurality of stored tools stored in the tool magazine with the second tool held by the tool spindle unit, 3. A machine tool according to claim 1 or 2.

4. The second spindle unit is configured to be immovable in the third direction, The tool rest is configured to be able to mount a plurality of the first tools arranged in the third direction, the machine tool includes a control unit that, when machining the workpiece held by the second spindle unit, moves the tool rest in the third direction via the tool rest moving mechanism to bring the workpiece into contact with any one of the first tools arranged in the third direction. A machine tool according to any one of claims 1 to 3.

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