Work transfer system and machine tool

Abstract

To provide a workpiece delivery system which enables reduction of the cycle time, and to provide a machine tool.SOLUTION: A workpiece delivery system delivers a workpiece W between a first spindle 11 and a second spindle and includes: a workpiece supply hand device 30L which is configured to supply the workpiece W to the first spindle 11 to perform first processing; a workpiece supply hand device which is configured to supply the workpiece W to the second spindle to perform second processing; and a loader hand device 40 which is configured to deliver a workpiece W1 before the first processing to the workpiece supply hand device 30L, receive a workpiece W2, to which the first processing has been performed, from the first spindle 11, and transport the received workpiece W2 to the workpiece supply hand device.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a workpiece transfer system and a machine tool.

Background Art

[0002] For example, the main spindle moving type automatic lathe described in Patent Document 1 includes first and second main spindles that are arranged to face each other in the Z-axis direction and are configured to be movable in the Z-axis direction, and a tool holder to which a tool for machining a workpiece held by the first main spindle or the second main spindle is attached. When the workpiece is transferred between the first and second main spindles, the tool holder moves to a region where it does not interfere with the first and second main spindles, and then the first and second main spindles move in the Z-axis direction so as to approach each other.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above Patent Document 1, since the first and second main spindles and the tool holder need to move, it takes time (kissing time) to transfer the workpiece between the first and second main spindles, and as a result, the cycle time, which is the time required to machine one workpiece, becomes long.

[0005] The present invention has been made in view of the above situation, and an object thereof is to provide a workpiece transfer system and a machine tool capable of shortening the cycle time.

Means for Solving the Problems

[0006] To achieve the above object, a workpiece transfer system according to a first aspect of the present invention is a workpiece transfer system that transfers a workpiece between a first spindle and a second spindle, and includes a first workpiece supply hand device configured to be able to supply the workpiece to the first spindle for performing a first machining, a second workpiece supply hand device configured to be able to supply the workpiece to the second spindle for performing a second machining, and being separate from the first workpiece supply hand device, and a loader hand device configured to transfer the workpiece before the first machining to the first workpiece supply hand device, receive the workpiece after the first machining from the first spindle, and transfer the received workpiece to the second workpiece supply hand device. The first workpiece supply hand device moves between a first supply position and a first retracted position where the distance from the first spindle is farther than the distance between the first spindle and the first supply position. The second workpiece supply hand device moves between a second supply position and a second retracted position where the distance from the second spindle is farther than the distance between the second spindle and the second supply position. The loader hand device transfers the workpiece before the first machining to the first workpiece supply hand device at the first retracted position while the workpiece is being machined by the first spindle. The first workpiece supply hand device supplies the workpiece to the first spindle for performing the first machining when it is at the first supply position. The loader hand device transfers the workpiece after the first machining to the second workpiece supply hand device at the second retracted position while the workpiece is being machined by the second spindle. The second workpiece supply hand device supplies the workpiece to the second spindle for performing the second machining when it is at the second supply position. The loader hand device moves in the left-right direction and the front-rear direction at a position higher than the first spindle and the second spindle, and also moves in the vertical direction to move to a position where it can transfer the workpiece to the first workpiece supply hand device and the second workpiece supply hand device, and to a position where it can receive the workpiece from the first spindle and the second spindle. 。

[0007] To achieve the above object, a machine tool according to a second aspect of the present invention includes the workpiece transfer system, the first spindle and the second spindle, and a tool unit that machines a workpiece held by the first spindle or the second spindle. Also, to achieve the above object, a machine tool according to a third aspect of the present invention is a machine tool for machining a workpiece, comprising the workpiece transfer system, the first spindle and the second spindle, and a tool unit for machining a workpiece held by the first spindle or the second spindle, wherein the storage unit is provided in the machine tool When viewed from the front, the back of the first spindle and the second spindle is provided.

Advantages of the Invention

[0008] According to the present invention, the cycle time can be shortened.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0010] Hereinafter, a workpiece transfer system and a machine tool according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a machine tool 1 that is a lathe includes a bed S that is a base of 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 plurality of first tool units 17, a plurality of second tool units 27, a first spindle moving mechanism 15Z, a second spindle moving mechanism 25Z, a workpiece transfer system 2, a control unit 300, and as shown in FIG. 2, a first tool moving mechanism 16, a second tool moving mechanism 26, a plurality of storage units 52 having shutters 51, and a pallet changer 55. As shown in FIG. 1, the workpiece transfer system 2 includes workpiece supply hand devices 30L and 30R and a loader hand device 40. Hereinafter, the axial direction along the rotation axes of the first spindle 11 and the second spindle 21 is defined as the Z-axis direction, the height direction orthogonal to the Z-axis direction is defined as the Y-axis direction, and the depth direction orthogonal to the Y-axis direction and the Z-axis direction is defined as the X-axis direction. In this example, the machine tool 1 extends in the Y-axis direction and has a symmetric configuration centered on a symmetry axis I located between the first spindle 11 and the second spindle 21. In particular, the first spindle unit 10 and the second spindle unit 20, the first tool unit 17 and the second tool unit 27, the first tool moving mechanism 16 and the second tool moving mechanism 26, and the workpiece supply hand device 30L and the workpiece supply hand device 30R each have a symmetric configuration centered on the symmetry axis I.

[0011] As shown in FIG. 1, the first spindle unit 10 rotates while holding the workpiece W. Specifically, the first spindle unit 10 includes a first spindle 11 and a first spindle base 12 that rotatably supports the first spindle 11. The first spindle 11 holds one end of the workpiece W. A workpiece rotation motor (not shown) that rotates the first spindle 11 is built into the first spindle base 12.

[0012] As shown in FIG. 6(a), the first spindle 11 includes a claw 11a that holds the workpiece W and a stopper 11b that positions the workpiece W. The claw 11a holds the workpiece W from its outer periphery. The stopper 11b is provided at a position surrounded by the claw 11a and abuts against the workpiece W held by the claw 11a to position the workpiece W in the Z-axis direction.

[0013] As shown in FIG. 1, the second spindle unit 20 is provided at a position opposite to 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 base 22 that rotatably supports the second spindle 21. A workpiece rotation motor (not shown) for rotating the second spindle 21 is built into the second spindle base 22.

[0014] As shown in FIG. 6(b), the second spindle 21 includes a claw 21a that holds the workpiece W, and a stopper 21b that positions the workpiece W. The claw 21a holds the outer diameter portion Wq of the inner column portion Wp of the workpiece W. The claw 21a is detachably fixed to the main body portion of the second spindle 21 by a fastening member 21c such as a bolt. The stopper 21b is provided at a position surrounded by the claw 21a, and contacts the workpiece W held by the claw 21a to position the workpiece W in the Z-axis direction.

[0015] As shown in FIG. 1, the first tool unit 17 processes the workpiece W held by the first spindle 11. The first tool unit 17 includes a tool 17a and a tool holder 17b that holds the tool 17a. The tool 17a is, for example, a drill or a cutting tool. The tool 17a extends along the Z-axis direction, and the cutting edge of the tool 17a faces the first spindle 11. As shown in FIG. 2, a plurality of first tool units 17 are arranged in the X-axis direction on the upper surface of a slide table 16s of a first tool moving mechanism 16 described later.

[0016] As shown in FIG. 1, the second tool unit 27 processes the workpiece W held by the second spindle 21. The second tool unit 27 includes a tool 27a and a tool holder 27b that holds the tool 27a. The tool 27a is, for example, a drill or a cutting tool. The tool 27a extends along the Z-axis direction, and the cutting edge of the tool 27a faces the second spindle 21. As shown in FIG. 2, a plurality of second tool units 27 are arranged in the X-axis direction on the upper surface of a slide table 26s of a second tool moving mechanism 26 described later.

[0017] As shown in FIG. 1, the first main spindle moving mechanism 15Z moves the first main spindle unit 10 in the Z-axis direction. The second main spindle moving mechanism 25Z moves the second main spindle unit 20 in the Z-axis direction. As shown in FIG. 2, the first tool moving mechanism 16 moves the first tool unit 17 in the X-axis direction. Specifically, the first tool moving mechanism 16 includes a slide table 16s on which each first tool unit 17 is installed, and the slide table 16s is configured to be movable in the X-axis direction. The second tool moving mechanism 26 moves the second tool unit 27 in the X-axis direction. Specifically, the second tool moving mechanism 26 includes a slide table 26s on which each second tool unit 27 is installed, and the slide table 26s is configured to be movable in the X-axis direction. The first main spindle moving mechanism 15Z, the second main spindle moving mechanism 25Z, the first tool moving mechanism 16, and the second tool moving mechanism 26 each have a motor, a ball screw, and a nut.

[0018] As shown in FIG. 7, the loader hand device 40 includes a hand unit 48, a hand rotation drive unit 43, hand moving mechanisms 46A, 46B, 46Y, a hand rotation mechanism 47, and a support member 49. The hand unit 48 includes a first hand part 41, a second hand part 42, and a hand support part 44. The first hand part 41 and the second hand part 42 are each configured to be able to hold the workpiece W. The first hand part 41 and the second hand part 42 are displaced between a holding state in which the workpiece W is held and a non-holding state in which this holding state is released by a drive unit such as a fluid cylinder (not shown). The hand support part 44 supports the first hand part 41 and the second hand part 42 so as to face in different directions from each other. The hand support part 44 has a substantially L shape. The first hand part 41 is located at the first end of the hand support part 44, and the second hand part 42 is located at the second end of the hand support part 44.

[0019] The first hand portion 41 extends along the center line C1, and the second hand portion 42 extends along the center line C2. The two center lines C1 and C2 intersect with each other and are perpendicular to each other in this example. The first hand portion 41 holds the workpiece W from its outer diameter. The second hand portion 42 holds the workpiece W from its inner diameter. The hand rotation drive unit 43 rotates the hand unit 48 about the rotation axis K. The rotation axis K extends along the angular bisector, in this example the bisector, formed by the two center lines C1 and C2. The hand rotation drive unit 43 is, for example, a rotary cylinder. By rotating the hand unit 48 about the rotation axis K, the hand rotation drive unit 43 can direct one of the first hand portion 41 and the second hand portion 42 in the Y-axis direction and the other of the first hand portion 41 and the second hand portion 42 in the Z-axis direction.

[0020] The hand rotation mechanism 47 rotates the hand unit 48 about the rotation axis G extending along the Y-axis direction. The rotation axis G is set at a position corresponding to the intersection of the center lines C1, C2 and the rotation axis K in this example. The hand rotation mechanism 47 is, for example, a rotary cylinder. The hand rotation mechanism 47 has a rotating portion 47a that rotates about the rotation axis G. A support member 49 that supports the hand rotation drive unit 43 is fixed to the rotating portion 47a. As shown in FIG. 1, the hand rotation mechanism 47 can turn the hand unit 48 in a direction in which it is inverted in the Z-axis direction by rotating the hand unit 48 about the rotation axis G. For example, the hand rotation mechanism 47 can change the orientation of the hand unit 48 between a first orientation shown by the solid line in FIG. 1 above the workpiece supply hand device 30L and a second orientation shown by the dashed-dotted line in FIG. 1 above the workpiece supply hand device 30R by rotating the hand unit 48 180° about the rotation axis G.

[0021] As shown in FIG. 1, the hand movement mechanism 46B moves the hand unit 48, the hand rotation drive unit 43, and the hand rotation mechanism 47 in the B-axis direction along the Z-axis direction. The hand movement mechanism 46B is configured to be able to move the hand unit 48 between the first spindle 11, the second spindle 21, and the pallet changer 55. The hand movement mechanism 46Y moves the hand unit 48, the hand rotation drive unit 43, and the hand rotation mechanism 47 in the Y-axis direction. As shown in FIG. 3, the hand movement mechanism 46A moves the hand unit 48, the hand rotation drive unit 43, and the hand rotation mechanism 47 in the A-axis direction along the X-axis direction. The hand movement mechanisms 46A, 46B, and 46Y each have a motor, a ball screw, and a nut.

[0022] As shown in FIG. 1, the workpiece supply hand device 30L receives the workpiece W from the loader hand device 40 and delivers the received workpiece W to the first spindle 11. The workpiece supply hand device 30R receives the workpiece W from the loader hand device 40 and delivers the received workpiece W to the second spindle 21. As shown in FIG. 2, the workpiece supply hand devices 30L and 30R move in the X-axis direction between the retracted position Q1 and the supply position Q2 by a movement mechanism (not shown). The retracted position Q1 is located within the storage unit 52. The supply position Q2 is outside the storage unit 52 and is located opposite to the first spindle 11 or the second spindle 21. This movement mechanism (not shown) has, for example, a motor, a ball screw, and a nut.

[0023] As shown in FIG. 6(a), the workpiece supply hand device 30L includes a hand part 31 that holds the workpiece W, a hand support part 32 that supports the hand part 31, and a hand rotation drive part 33 that rotates the hand support part 32. The hand support part 32 extends along the central axis 32C. The hand part 31 is provided at the tip of the hand support part 32. The hand part 31 is displaced between a holding state in which the work W is held and a non-holding state in which this holding state is released by a driving part such as a fluid cylinder (not shown). In this example, the hand part 31 holds the work W by moving in the radially expanding direction and pressing the inner peripheral surface Wi of the work W. The hand rotation driving part 33 rotates the hand support part 32 around the rotation axis 32O. The hand rotation driving part 33 is, for example, a rotary cylinder. The rotation axis 32O intersects the central axis 32C of the hand support part 32 and, in this example, is orthogonal to the central axis 32C. The rotation axis 32O passes through the base end part on the side opposite to the hand part 31 of the hand support part 32. When the work supply hand device 30L is at the supply position Q2, the hand rotation driving part 33 displaces the hand part 31 between a first posture shown in FIG. 4(d) facing the first spindle 11 and a second posture shown in FIG. 4(a) facing the hand unit 48. In the first posture, the central axis 32C of the hand support part 32 is along the Z-axis direction, and in the second posture, the central axis 32C of the hand support part 32 is along the Y-axis direction.

[0024] As shown in FIG. 6(b), the work supply hand device 30R, similar to the work supply hand device 30L, includes a hand part 31 that holds the work W, a hand support part 32 that supports the hand part 31, and a hand rotation driving part 33 that rotates the hand support part 32. The hand part 31 of the work supply hand device 30R holds the outer peripheral surface Wo of the work W. Except for this point, the work supply hand device 30R has the same configuration as the work supply hand device 30L.

[0025] As shown in FIG. 2, one of the two storage parts 52 stores the work supply hand device 30L, and the other stores the work supply hand device 30R. Each storage part 52 is provided in a wall shape on the upper surface of the bed S, respectively, and forms a storage space 52K separated from the machining zone, which is the space where the work W is machined. The shutter 51 is moved in the Z-axis direction by a drive unit such as a fluid cylinder (not shown) so as to open and close the openings of the respective storage units 52. The openings of the respective storage units 52 are formed at positions facing the machining zone. With the work supply hand devices 30L and 30R positioned in the storage spaces 52K of the storage units 52, the shutter 51 closes the openings of the storage units 52. This suppresses the adhesion of chips or coolant fluid generated during machining to the work supply hand devices 30L and 30R.

[0026] As shown in FIGS. 1 and 2, the pallet changer 55 transports a pallet 56 on which a plurality of workpieces W are installed to a position where it can be received by the loader hand device 40. The pallet changer 55 is provided on the side of the bed S and behind the first spindle unit 10.

[0027] The control unit 300 controls the first spindle unit 10, the second spindle unit 20, the first spindle moving mechanism 15Z, the second spindle moving mechanism 25Z, the first tool moving mechanism 16, the second tool moving mechanism 26, the work supply hand devices 30L and 30R, the loader hand device 40, the shutter 51, and the pallet changer 55. The control unit 300 includes, for example, a CPU (Central Processing Unit) (not shown) and a ROM (Read Only Memory) that stores a program defining the procedure of processing by the CPU.

[0028] Next, the machining process executed by the control unit 300 will be described. The control unit 300 executes this machining process according to a previously created NC program. First, as shown by the arrow J1 in FIG. 1, the control unit 300 moves the hand unit 48 via the hand moving mechanisms 46A, 46B, and 46Y, and holds the unprocessed workpiece W1 on the pallet 56 with the first hand portion 41 (see FIG. 4) of the hand unit 48. Then, as shown by the arrow J2 in FIG. 1, the control unit 300 moves the hand unit 48 via the hand moving mechanisms 46A, 46B, and 46Y to a position facing the work supply hand device 30L located at the retracted position Q1.

[0029] Next, as shown in Fig. 4(a), the control unit 300 turns the hand unit 31 toward the first hand unit 41 as the second posture via the hand rotation drive unit 33. Then, the control unit 300 opposes the first hand unit 41 to the hand unit 31 of the work supply hand device 30L via the hand movement mechanisms 46A, 46B, 46Y, and transfers the unprocessed work W1 from the first hand unit 41 to the hand unit 31. As described above, when the unprocessed work W1 is carried from the pallet 56 to the work supply hand device 30L by the loader hand device 40, the shutter 51 is in the closed state, and the first processing is being performed on the work W2 (see Fig. 4(b)) held by the first spindle 11. The control unit 300 makes the hand unit 48 standby above the first spindle 11 until this first processing is completed.

[0030] When the first processing of the work W2 is completed, the control unit 300 opens a shutter (not shown) located above the first spindle 11, and moves (lowers) the loader hand device 40 in the Y-axis direction so that the second hand unit 42 faces the first spindle 11 as shown by the arrow J3 in Fig. 4(b), and the second hand unit 42 receives the first processed work W2 from the first spindle 11. Note that immediately after the start of the processing, the first processed work W2 is not held by the first spindle 11. In this case, the process of the second hand unit 42 receiving the first processed work W2 from the first spindle 11 may be omitted.

[0031] Then, as shown by the arrow J4 in Fig. 4(c), the control unit 300 retracts (raises) the hand unit 48 in the Y-axis direction from the tip side of the first spindle 11, opens the shutter 51 corresponding to the work supply hand device 30L, and moves the work supply hand device 30L from the retracted position Q1 to the supply position Q2. At this time, as shown by the arrow J5 in Fig. 4(c), the control unit 300 rotates the hand support part 32 via the hand rotation drive unit 33 to make the hand unit 31 assume the first posture facing the first spindle 11. Then, as shown in Fig. 4(d), the control unit 300 transfers the unprocessed work W1 from the hand unit 31 to the first spindle 11. Note that the workpiece supply hand device 30L may start moving from the retracted position Q1 to the supply position Q2 and wait at a standby position close to the supply position Q2 simultaneously with or before and after the lowering of the loader hand device 40 described above. This standby position is a position that does not interfere with the loader hand device 40. Thereby, the cycle time can be shortened.

[0032] Then, as shown by the arrow J6 in FIG. 2, after positioning the workpiece supply hand device 30L at the retracted position Q1, the control unit 300 closes the shutter 51. Thereafter, the control unit 300 starts the first machining of the workpiece W1 held by the first spindle 11.

[0033] Also, as shown by the arrow J4 in FIG. 4(c), immediately after raising the hand unit 48, the control unit 300 moves the hand unit 48 to a position facing the workpiece supply hand device 30R located at the retracted position Q1 via the hand movement mechanisms 46A, 46B, and 46Y as shown by the arrows J7, J8, and J9 in FIG. 1. Note that both the first machining and the second machining can be performed even during the conveyance of the workpiece W2. Also, during, before, or after the movement of the hand unit 48, the control unit 300 rotates the hand unit 48 by 180° about the rotation axis G via the hand rotation mechanism 47 as shown by J10 in FIG. 7, and rotates the hand unit 48 by 180° about the rotation axis K via the hand rotation drive unit 43 as shown by J11 in FIG. 7. Thereby, as shown in FIG. 5(a), the second hand portion 42 faces the Y-axis direction and the first hand portion 41 faces the Z-axis direction. At this time, the control unit 300 sets the hand portion 31 to a second posture facing the hand unit 48 via the hand rotation drive unit 33 of the workpiece supply hand device 30R.

[0034] Next, as shown in FIGS. 5(a) to 5(d), in the same manner as FIGS. 4(a) to 4(d), the loader hand device 40 and the workpiece supply hand device 30R cooperate to transfer the workpiece W to and from the second spindle 21. Specifically, as shown in FIG. 5(a), the control unit 300 positions the second hand part 42 opposite to the hand part 31 of the work supply hand device 30R, and transfers the first processed work W2 from the second hand part 42 to the hand part 31 of the work supply hand device 30R located at the retracted position Q1. As described above, when the first processed work W2 is transported from the first spindle 11 to the work supply hand device 30R by the loader hand device 40, the shutter 51 corresponding to the work supply hand device 30R is in a closed state, and the second processing is being performed on the work W3 (see FIG. 5(b)) held by the second spindle 21. The control unit 300 causes the hand unit 48 to standby above the second spindle 21 until the second processing is completed.

[0035] When the second processing of the work W3 is completed, the control unit 300 opens a shutter (not shown) located above the second spindle 21, moves the loader hand device 40 in the Y-axis direction (downward) so that the first hand part 41 faces the second spindle 21, and the first hand part 41 receives the second processed work W3 from the second spindle 21. Note that immediately after the start of the processing, the second processed work W3 is not held by the second spindle 21. In this case, the process of the first hand part 41 receiving the second processed work W3 from the second spindle 21 may be omitted.

[0036] Then, the control unit 300 retracts (raises) the hand unit 48 in the Y-axis direction from the tip side of the second spindle 21, opens the shutter 51 corresponding to the work supply hand device 30R, and moves the work supply hand device 30R from the retracted position Q1 to the supply position Q2. Note that, as described above, the work supply hand device 30R may standby at a standby position close to the supply position Q2. At this time, as shown in FIG. 5(c), the control unit 300 rotates the hand support part 32 via the hand rotation drive part 33 to set the hand part 31 in a first posture facing the second spindle 21. Then, as shown in FIG. 5(d), the control unit 300 transfers the first processed work W2 from the hand part 31 to the second spindle 21.

[0037] Then, after positioning the workpiece supply hand device 30R at the retracted position Q1, the control unit 300 closes the shutter 51. After that, the control unit 300 starts the second machining of the workpiece W2 held by the second spindle 21.

[0038] Also, as described above, after raising the hand unit 48 that has received the second machined workpiece W3, immediately, the control unit 300 moves the hand unit 48 to a position facing the pallet 56 via the hand movement mechanisms 46A, 46B, 46Y, and returns the second machined workpiece W3 to the position where the unprocessed workpiece W1 was on the pallet 56. The machining process described above is repeatedly executed every time the workpiece W is supplied. This concludes the description of the machining process.

[0039] (Effect) According to the embodiment described above, the following effects can be obtained. (1) The workpiece transfer system 2 that transfers the workpiece W between the first spindle 11 and the second spindle 21 includes a workpiece supply hand device 30L which is an example of a first workpiece supply hand device configured to be able to supply the workpiece W to the first spindle 11 for performing the first machining, a workpiece supply hand device 30R which is an example of a second workpiece supply hand device configured to be able to supply the workpiece W to the second spindle 21 for performing the second machining, and a loader hand device 40 configured to transfer the workpiece W1 before the first machining to the workpiece supply hand device 30L, receive the workpiece W2 after the first machining from the first spindle 11, and be able to convey the received workpiece W2 to the workpiece supply hand device 30R. According to this configuration, even while the loader hand device 40 is conveying the workpiece W2 from the first spindle 11 to the second spindle 21, it is possible to supply the workpiece W to the first spindle 11 by the workpiece supply hand device 30L or perform the machining (the first machining and the second machining) of the workpiece W. As a result, the cycle time can be shortened.

[0040] (2) The first spindle 11 and the second spindle 21 are positioned to face each other in the Z-axis direction, which is an example of the first direction. The loader hand device 40 includes a first hand portion 41 configured to be able to transfer the workpiece W1 to the workpiece supply hand device 30L, a second hand portion 42 configured to be able to receive the first machined workpiece W2 from the first spindle 11, a hand support portion 44 that supports the first hand portion 41 and the second hand portion 42 so as to face different directions from each other, and a hand rotation mechanism 47 that rotates the hand support portion 44 about a rotation axis G extending in the Y-axis direction, which is an example of the second direction intersecting the Z-axis direction. According to this configuration, without using a workpiece inversion device that inverts the workpiece W in its axial direction, the loader hand device 40 can supply the workpiece W2 received from the first spindle 11 to the second spindle 21 via the workpiece supply hand device 30R. As a comparative example, in a configuration having a discharge hand portion for receiving the workpiece W provided such that the workpiece supply hand devices 30L and 30R are arranged side by side in the hand portion 31, the workpiece W held by the first spindle 11 is supplied in the order of discharge hand portion → loader hand device 40 → workpiece inversion device → loader hand device 40 → workpiece supply hand device 30R → second spindle 21. In the configuration according to this comparative example, it is necessary to supply the workpiece W from the loader hand device 40 to the workpiece inversion device, invert the workpiece W in the workpiece inversion device, and then supply it to the loader hand device 40. The operation of gripping the workpiece W is increased, and the probability of chucking failure also increases. In this regard, in the above configuration, since the workpiece inversion device is unnecessary, the configuration can be simplified. Also, the operation of gripping the workpiece W can be reduced, and the probability of chucking failure is also lowered.

[0041] (3) The workpiece supply hand devices 30L and 30R each include a hand portion 31, which is an example of a third hand portion configured to be able to hold the workpiece W, and a hand rotation drive portion 33 that rotates the hand portion 31 between a position facing the first hand portion 41 or the second hand portion 42 of the loader hand device 40 and a position facing the first spindle 11 or the second spindle 21. According to this configuration, the work supply hand devices 30L and 30R can change the posture of the work W received from the loader hand device 40 and then transfer the work W to the first spindle 11 or the second spindle 21.

[0042] (4) The machine tool 1 includes a work transfer system 2, a first spindle 11 and a second spindle 21, and a first tool unit 17 and a second tool unit 27 which are examples of tool units for machining the work W held by the first spindle 11 and the second spindle 21. According to this configuration, in the machine tool 1, the cycle time can be shortened as described above.

[0043] Note that the present disclosure is not limited to the above embodiments and drawings. Modifications (including deletion of components) can be appropriately made without changing the gist of the present disclosure. An example of a modification will be described below.

[0044] (Modification example) The moving directions of the work supply hand devices 30L and 30R, the hand unit 48, the first spindle unit 10, the second spindle unit 20, the first tool unit 17, and the second tool unit 27 in the above embodiment can be appropriately changed. For example, although the work supply hand devices 30L and 30R are each configured to be movable in the X-axis direction, the present invention is not limited to this, and they may be configured to be immovable in the X-axis direction, and instead, the first spindle unit 10 and the second spindle unit 20 may be configured to be movable in the X-axis direction.

[0045] In the above embodiment, the first spindle unit 10 and the second spindle unit 20 are positioned to face each other in the Z-axis direction, but the present invention is not limited to this, and they may be arranged in the X-axis direction. In this case, the hand rotation mechanism 47 may be omitted. Also, the storage unit 52 in the above embodiment can be omitted.

Explanation of reference numerals

[0046] 1... Machine tool, 2... Work transfer system, 10... First spindle unit, 11... First spindle, 11a, 21a... Claws, 11b, 21b... Stoppers, 12... First spindle base, 15Z... First spindle moving mechanism, 16... First tool moving mechanism, 16s, 26s... Slide tables, 17... First tool unit, 17a, 27a... Tools, 17b, 27b... Tool holders, 20... Second spindle unit, 21... Second spindle, 21c... Fastening member, 22... Second spindle base, 25Z... Second spindle moving mechanism, 26... Second tool moving mechanism, 27... Second tool unit, 30L, 30R... Work supply hand device, 31... Hand part, 32, 44... Hand support parts, 32C... Central axis, 32O... Rotation axis, 33, 43... Hand rotation drive parts, 40... Loader hand device, 41... First hand part, 42... Second hand part, 46A, 46B, 46Y... Hand moving mechanisms, 47... Hand rotation mechanism, 47a... Rotation part, 48... Hand unit, 49... Support member, 51... Shutter, 52... Storage part, 52K... Storage space, 55... Pallet changer, 56... Pallet, 300... Control unit, C1, C2... Center lines, G, K... Rotation axes, I... Axis of symmetry, Q1... Retraction position, S... Bed, Q2... Supply position, W, W1, W2, W3... Workpieces, Wi... Inner peripheral surface, Wo... Outer peripheral surface, Wp... Inner column part, Wq... Outer diameter part

Claims

1. A workpiece transfer system for transferring a workpiece between a first spindle and a second spindle, comprising: a first workpiece supply hand device configured to be able to supply a workpiece to the first spindle for performing a first machining; a second workpiece supply hand device, separate from the first workpiece supply hand device, configured to be able to supply a workpiece to the second spindle for performing a second machining; a loader hand device configured to transfer the workpiece before the first machining to the first workpiece supply hand device, receive the workpiece after the first machining from the first spindle, and transfer the received workpiece to the second workpiece supply hand device; the first workpiece supply hand device moves between a first supply position and a first retracted position where the distance from the first spindle is farther than the distance between the first spindle and the first supply position; the second workpiece supply hand device moves between a second supply position and a second retracted position where the distance from the second spindle is farther than the distance between the second spindle and the second supply position; the loader hand device transfers the workpiece before the first machining to the first workpiece supply hand device at the first retracted position while the workpiece is being machined by the first spindle; the first workpiece supply hand device supplies the workpiece to the first spindle for performing the first machining when it is at the first supply position; the loader hand device transfers the workpiece after the first machining to the second workpiece supply hand device at the second retracted position while the workpiece is being machined by the second spindle; the second workpiece supply hand device supplies the workpiece to the second spindle for performing the second machining when it is at the second supply position; the loader hand device moves in the left - right direction and the front - rear direction at a position higher than the first spindle and the second spindle, and also moves in the vertical direction to move to a position where it can transfer the workpiece to the first workpiece supply hand device and the second workpiece supply hand device, and move to a position where it can receive the workpiece from the first spindle and the second spindle; A workpiece transfer system.

2. The first supply position and the second supply position are located in a machining zone where the workpiece is machined; The first retracted position and the second retracted position are located in a storage space formed in a storage section. The storage unit stores the first workpiece supply hand device at the first retracted position and the second workpiece supply hand device at the second retracted position in the storage space separated from the tooling zone. The direction in which the first workpiece supply hand device moves between the first supply position and the first retracted position is different from the rotational axis direction of the first spindle. The direction in which the second workpiece supply hand device moves between the second supply position and the second retracted position is different from the rotational axis direction of the second spindle. The workpiece transfer system according to claim 1.

3. The workpiece transfer system according to claim 1 or 2, the first spindle and the second spindle, and a tool unit that processes a workpiece held by the first spindle or the second spindle. Machine tool.

4. A machine tool for processing a workpiece, the workpiece transfer system of claim 2, the first spindle and the second spindle, and a tool unit that processes a workpiece held by the first spindle or the second spindle, wherein the storage unit is provided behind the first spindle and the second spindle when the machine tool is viewed from the front. Machine tool.

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