Machine tool

Abstract

In order to provide a machine tool provided with a compact unloading loader device in the machine, the present invention is provided with: a discharge device that is separated by a partition wall from a processing chamber in which processing of a workpiece gripped by a main shaft chuck is performed, and is disposed outside the processing chamber; and a loader device that conveys the processed workpiece from the main shaft chuck to the discharge device, the loader device having a robot hand that grips a workpiece in the main shaft chuck, a drive device that causes the robot hand to move between the processing chamber and the outside of the processing chamber and perform the operation of receiving a workpiece, and a door member that is formed integrally with the robot hand and closes an opening formed in the partition wall by movement from the processing chamber to outside the processing chamber.

Description

machine tools

[0001] The present invention relates to a machine tool provided with a loader device for carrying out a machined workpiece from a machining chamber.

[0002] In order to automate machining processes, machine tools such as NC lathes use a loader device to load and unload workpieces within the machine. While some loader devices are installed outside the machine, this increases the overall installation area of ​​the machine. Therefore, a machine tool with an internal loader device is disclosed in Patent Document 1 below. The first conventional example in this document is a vertical NC lathe with an internal loader device, in which a spindle chuck is installed vertically upward in the machining chamber, and a turret device installed above it is movable in the front-to-rear and up-and-down directions of the machine body.

[0003] The loader device is located outside the machining chamber and is separated by a partition wall to prevent it from being affected by chips and coolant during machining, and an opening / closing door is attached to the partition wall. The loader device is configured so that a loader arm can enter and exit the machining chamber when the opening / closing door is opened. That is, the L-shaped loader arm is equipped with a loader chuck at its tip that can grip a workpiece, and the loader chuck can enter and exit the machining chamber by moving up and down and swinging (oscillating).

[0004] Furthermore, Patent Document 2 below discloses a compact loader device arranged adjacent to a spindle chuck and a turret tool rest in a machining chamber. In a second conventional loader device described in the same document, a robot hand consisting of an extendable arm with a hand attached and a swing motor is arranged outside the machining chamber. The robot hand is configured to reciprocate along a traverse guide parallel to the spindle so as to enter and exit an opening formed in a partition wall above the spindle chuck. A sliding shutter is provided in the opening, and the extendable arm waits outside the machining chamber during workpiece machining. Upon completion of machining, the sliding shutter opens, allowing the extendable arm to enter the machining chamber through the opening, pick up the workpiece from the spindle chuck, and return to a waiting position outside the machining chamber.

[0005] Furthermore, Patent Document 2 below discloses a third conventional example that solves the problem of the second example, in which the workpiece discharge operation requires a robot to pass through an opening in a partition wall and travel back and forth between a standby position outside the machining chamber and the inside of the machining chamber, which takes time and reduces productivity. In this third conventional example, a robot hand equipped with a workpiece hand at the end of an arm that rotates around a fulcrum axis is disposed in the machining chamber. Furthermore, an unloading conveyor protrudes into the machining chamber, and a protective case with a sliding door that can be opened and closed is provided at that portion. Thus, the unloading operation of the machined workpiece is configured to be performed within the machining chamber.

[0006] Japanese Patent Laid-Open No. 4-82603 Japanese Patent Laid-Open No. 2005-161420

[0007] First, in the first conventional example disclosed in Patent Document 1, a loader device outside the machining chamber is separated from the machining chamber by a partition wall, and a swinging motion of a loader arm is performed through a large opening / closing door formed in the partition wall. This swinging motion moves the loader chuck between a standby state outside the machining chamber and a working state where it has entered the machining chamber. However, this configuration does not allow for the placement of a spindle device, a turret device, etc. on the side of the machining chamber where the loader device is located, and therefore cannot be applied to a twin-spindle lathe such as that described in Patent Document 2.

[0008] In this regard, the second and third conventional examples described in Patent Document 2 have a compact loader device configured above the spindle device, etc. However, in the third conventional example, in which the robot hand is installed inside the machining chamber, the loader device is constantly exposed to coolant and chips during machining, and the loader device becomes a hindrance when an operator performs tool replacement or maintenance work inside the machining chamber. On the other hand, the second conventional example is installed outside the machining chamber, so the problem of the third conventional example does not occur. However, in the second conventional example, when the robot hand moves through an opening formed in the partition wall, the slide shutter must be opened and closed each time, which is time-consuming and requires the opening and closing mechanism to be installed in a narrow space.

[0009] SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a machine tool equipped with a loader device for carrying out work inside the machine.

[0010] In one aspect of the present invention, a machine tool comprises: a discharge device arranged outside a machining chamber separated by a partition wall from a machining chamber in which machining of a workpiece held by a spindle chuck is performed; and a loader device that transports the machined workpiece from the spindle chuck to the discharge device, wherein the loader device has a robot hand that grasps the workpiece from the spindle chuck; a drive device that causes the robot hand to move between the machining chamber and outside the machining chamber and to receive the workpiece; and a door member formed integrally with the robot hand that closes an opening formed in the partition wall by moving from the machining chamber to outside the machining chamber.

[0011] According to the above configuration, when machining is performed on a workpiece held by the spindle chuck in the machining chamber, the robot hand moves into the machining chamber from outside the machining chamber to receive the workpiece, and then moves back out of the machining chamber to send the machined workpiece it is holding to the discharge device. The robot hand then returns from the machining chamber to outside the machining chamber through an opening formed in the partition wall, and at this time, a door member formed integrally with the robot hand closes the opening in the partition wall, thereby isolating the inside of the machining chamber from the outside.

[0012] FIG. 1 is a first sectional perspective view showing an embodiment of a machine tool so that the internal structure of the machine body can be seen; FIG. 2 is a second sectional perspective view showing an embodiment of a machine tool so that the internal structure of the machine body can be seen; FIG. 3 is a perspective view showing a part of a working state of a series of operations of a loader device; FIG. 4 is a perspective view showing a part of a working state of a series of operations of a loader device; FIG. 5 is a sectional perspective view showing a part of a workpiece discharge and standby state of a series of operations of a loader device;

[0013] An embodiment of a machine tool according to the present invention will be described below with reference to the drawings. FIGS. 1 and 2 are cross-sectional perspective views of the machine tool according to this embodiment, taken from the front of the machine body toward the rear at different positions so as to particularly show the internal structure of the machine body. Machine tool 1 according to this embodiment is a small NC lathe in which various machining devices for machining a workpiece are mounted on a forward-inclined, slant-type bed 2. Machine tool 1 includes a machining chamber 10, which is an enclosed space in which a workpiece is machined with tools, and the entire machine body is covered by a machine body cover 30. Within machining chamber 10, the various machining devices that are directly related to the workpiece are arranged via a sealed structure.

[0014] When viewed from the front, a first work spindle device 3 and a second work spindle device 4, which rotatably grip a workpiece, are arranged opposite each other on the left and right sides of the bed 2, and an upper turret device 5 and a lower turret device 6, which are equipped with a plurality of tools for machining the workpiece, are arranged in front and behind the second work spindle device 4. The first and second work spindle devices 3, 4 have their respective spindles parallel to the machine body width direction, and are arranged opposite each other so that the spindles are coaxial. In this embodiment, the direction parallel to the spindles of the first and second work spindle devices 3, 4 (the width direction of the bed 2 from left to right) will be described as the Z-axis. The second work spindle device 4, which is coaxial with the first work spindle device 3, is configured to move in the machine body width direction, which is parallel to the Z-axis.

[0015] The first workpiece spindle device 3 has a rotatable spindle mounted on a casing, and a spindle chuck 11 integral with the spindle is rotatable by a spindle motor. The spindle chuck 11 is located within the machining chamber 10 and is designed to grip and rotate a workpiece fed thereto. The machine tool 1 is capable of machining workpieces (bar material) fed from a bar feeder, and a workpiece insertion section 12 is provided on the left side of the machine body. Therefore, a workpiece is inserted from the bar feeder into the hollow spindle of the first workpiece spindle device 3, and the tip portion of the workpiece protruding a predetermined length is gripped by the spindle chuck 11.

[0016] The second workpiece spindle device 4 is also configured so that a rotatable spindle is provided in a casing, and a spindle chuck 13 integrated with the spindle is rotated by a spindle motor. The spindle chuck 13 is located on the opposite side of the spindle chuck 11 in the machining chamber 10, and is configured to grip and rotate the workpiece received from the spindle chuck 11. The first workpiece spindle device 3 has a headstock fixed to the bed 2, while the second workpiece spindle device 4 is mounted on a spindle table and is configured to be movable in the Z-axis direction. Specifically, a linear guide is formed by a guide rail parallel to the Z-axis on the bed 2 and a guide block on the spindle table side, and a ball screw mechanism that converts the rotational output of the servo motor into linear movement is configured for the movable spindle table.

[0017] The machine tool 1 is a two-turret, opposed-spindle lathe in which an upper turret unit 5 and a lower turret unit 6 are arranged on either side of the second workpiece spindle unit 4. Because the bed 2 of the machine tool 1 is tilted forward, the upper turret unit 5 at the rear of the machine body is positioned higher than the second workpiece spindle unit 4, and the lower turret unit 6 at the front of the machine body is positioned lower than the second workpiece spindle unit 4. The upper and lower turret units 5, 6 have the same structure, and a plurality of tools (turret tools) are arranged at equal intervals in the circumferential direction on disk-shaped turret tool rests 15, 16 and are detachably attached.

[0018] The upper and lower turret devices 5, 6 have turret tool rests 15, 16 equipped with tools positioned within the machining chamber 10, and are designed to rotate to index the tool used for machining. Furthermore, the turret tool rests 15, 16 are configured to move within the machining chamber 10 in the Z-axis direction, a vertical direction perpendicular to the Z-axis, and a 45-degree direction that coincides with the inclination of the upper surface of the bed 2. In this embodiment, the vertical direction is defined as the Y-axis, and the inclination direction of the bed 2 is defined as the X-axis.

[0019] In the upper and lower turret devices 5, 6, linear guides are formed by guide rails parallel to the Z-axis on the bed 2 and guide blocks fixed to the turret table, and the turret table is configured to move linearly by a ball screw mechanism that converts the rotational output of a servo motor into linear movement. Furthermore, a turret X-axis slide is slidably attached to the top surface of the turret table by a linear guide in the X-axis direction, and a turret main body with a turret tool rest 15 or 16 mounted thereon is slidably attached to the turret X-axis slide by a linear guide in the Y-axis direction. The turret X-axis slide and turret main body are each configured to move linearly by a ball screw mechanism that converts the rotational output of a servo motor into linear movement.

[0020] Next, the machine tool 1 is provided with a loader device for unloading the workpiece from the machining chamber 10. Figures 3 to 5 are perspective views showing the loader device, showing the state at each stage. In the machine tool 1, a workpiece carried in from the first workpiece spindle device 3 side is transferred to the second workpiece spindle device 4 side and then unloaded to the outside of the machine. Therefore, the loader device 8 is provided on the second workpiece spindle device 4 side of the machining chamber 10. In particular, the loader device 8 in this embodiment is provided outside the machining chamber 20, separated from the machining chamber 10 by a partition wall 18, together with a discharge conveyor 9, which serves as a discharge device.

[0021] In the loader device 8, a robot hand 21 consisting of a pair of chuck jaws 31 for gripping a workpiece is fixed to the tip of a shaft 23 extending in a direction parallel to the Z axis. The robot hand 21 is configured so that the pair of chuck jaws 31 can be opened and closed by an opening / closing cylinder 32 consisting of an air cylinder. The opening / closing cylinder 32 and the chuck jaws 31, which are configured as an integral unit, can be displaced in a direction A perpendicular to the shaft 23 by the output of an advancing / retracting cylinder 33 also consisting of an air cylinder.

[0022] 3 to 5, the hand cover 22 that originally surrounds the robot hand 21 as shown in Fig. 1 has been omitted to make the structure easier to understand. This hand cover 22 prevents coolant from adhering to the robot hand 21 inside the machining chamber 10 and also functions to close the opening 19 in the partition wall 18. Outside the machining chamber 10 of the machine tool 1, there is an outside machining chamber 20 separated by the partition wall 18, where a loader device 8 and a discharge conveyor 9 are incorporated. The loader device 8 is configured so that the robot hand 21 moves between the machining chamber 10 and the outside machining chamber 20 through the opening 19.

[0023] A storage box 37 is provided outside the machining chamber 20 of the partition 18 so as to surround the opening 19. The storage box 37 is a storage section for the robot hand 21, and is configured in a shape that looks like a recess in the partition 18 when viewed from the machining chamber 10 side. When a workpiece is being machined in the machining chamber 10, the loader device 8 has the robot hand 21 enter the storage box 37 together with the hand cover 22 and enter a standby state.

[0024] At this time, the loader device 8 is configured so that the opening 19 of the partition wall 18 is closed simply by inserting the hand cover 22 into the storage box 37. Therefore, as shown in Fig. 6, one surface of the hand cover 22, which is a housing, is formed as a door surface 221 that closes the opening 19 of the partition wall 18. The door surface 221 is a plate material that is formed larger than the opening 19 and is formed larger than the other surface that enters the storage box 37. Note that Fig. 6 is a cross-sectional perspective view showing a part of the loader device 8 from outside the processing chamber 10, opposite to the direction shown in Figs. 3 to 5.

[0025] The loader device 8 has a shaft 23 that extends from the outside of the machining chamber 20 into the machining chamber 10, and the shaft 23 passes through the storage box 37 and the opening 19, at the tip of which the robot hand 21 is fixed perpendicularly. The shaft 23 is connected to a Z-axis cylinder 25 that performs piston movement in the Z-axis direction, and its center line O can be displaced in a direction parallel to the Z-axis. The Z-axis cylinder 25 is a rodless air cylinder, and a slider 251 is connected to the piston that moves within the cylinder tube. The shaft 23 is assembled to the slider 251 so as to be rotatable about the center line O.

[0026] A support bracket 26 is fixed to the slider 251, and the shaft 23 is supported thereon via a bearing. Furthermore, a crank mechanism is configured on the support bracket 26 for rotating the robot hand 21 via the shaft 23. This crank mechanism converts the linear motion caused by the extension and contraction of the rotation cylinder 27 into rotational motion of the shaft 23 based on the center line O. A link lever 28 that rotates integrally with the shaft 23 is fixed to the shaft 23, and the tip of the link lever 28, which is away from the center line O, and the tip of the piston rod 271 of the rotation cylinder 27 are pin-connected at the point of application P via a connecting member. Note that a hydraulic cylinder is used for the rotation cylinder 27.

[0027] The rotation cylinder 27 itself must change its position so that its extension and contraction movement is linked to the rotation of the link lever 28, and the rod side end of the cylinder tube 273 is journaled to the support bracket 26. The robot hand 21 shown in Figures 4 to 6 is in a position where it can enter the storage box 37, and in this embodiment, this state will be described as the standby position of the robot hand 21. The crank mechanism rotates the robot hand 21 to change its position, but the standby position of the robot hand 21 is maintained by the extended state of the rotation cylinder 27 with the piston rod 271 extended.

[0028] The loader device 8 carries the machined workpiece received by the robot hand 21 in the machining chamber 10 into a storage box 37 and discharges it outside the machine. As shown in Figures 3 to 5, the machine tool 1 is provided with a discharge conveyor 9, which serves as a discharge device, connected to the storage box 37. When the workpiece is released from the robot hand 21, it rolls down from the storage box 37 and is transferred to the discharge conveyor 9.

[0029] The storage box 37 has a rectangular parallelepiped shape corresponding to the size of the hand cover 22, and a notch 371 is formed on one side thereof, which serves as the opening 19 of the partition wall 18. The storage box 37 also has a discharge opening 372 formed on its lower bottom surface, which is positioned in a forward-leaning position, and a guide plate 38 is formed therein so that the workpieces can roll onto the discharge conveyor 9. The storage box 37 is connected to the workpiece receiver 51 of the discharge conveyor 9 by the guide plate 38. The hand cover 22, which has a similar box shape, also has an access opening 223 formed therein through which the chuck jaws 31 can enter and exit, allowing the robot hand 21 to receive and discharge the workpieces.

[0030] The discharge conveyor 9 is provided inside the machine tool 1 (outside the machining chamber 20), and extends in the Z-axis direction from the position of the storage box 37 to the right side of the machine body cover 30. Although not shown in detail, the discharge conveyor 9 has an endless conveyor belt 52 stretched over a splined shaft, with guides 53 provided to sandwich the conveyor belt 52, and is configured to transport workpieces to a discharge section 55 at the end located outside the machine. In addition, a coolant receiver is provided like a gutter below the workpiece receiver 51, so that coolant that falls from the workpieces is returned into the machining chamber 10.

[0031] Next, the machine tool 1 of this embodiment processes the workpiece and discharges the machined workpiece as follows. Workpiece processing can be performed in two ways: a first processing on the workpiece on the first workpiece spindle device 3 side, and a second processing on the workpiece on the second workpiece spindle device 4 side. In the first processing, a bar material workpiece is inserted into the spindle of the first workpiece spindle device 3 from outside the machine by a bar feeder, and the tip of the workpiece is gripped by the spindle chuck 11. The workpiece is then subjected to a predetermined processing by tools on one or both of the upper and lower turret devices 5 and 6.

[0032] In the upper and lower turret units 5, 6, the tools used for machining are indexed by the rotation of the turret tool rests 15, 16. The turret tool rests 15, 16 then move within the machining chamber 10 so that the tools are sent to the machining position for the workpiece. The turret tool rests 15, 16 move in the Z-axis direction within the machining chamber 10 from right to left toward the first workpiece spindle unit 3, and then move further in the X-axis and Y-axis directions so that the cutting edge is brought into contact with the workpiece. In this way, turning and other machining operations are performed on the rotating workpiece. In the machine tool 1, after the first machining operation is completed, the workpiece is transferred to the second workpiece spindle unit 5 and the second machining operation is performed.

[0033] As the spindle table of the second workpiece spindle device 5 moves in the Z-axis direction, the spindle chuck 13 approaches the machined workpiece and grips its tip. The spindle chucks 11, 13 gripping the workpiece are rotated synchronously by the first and second workpiece spindle devices 3, 4, and the workpiece is separated from the spindle chuck 11 on the first workpiece spindle device 3 side by a cut-off bit in the upper turret device 5 (or lower turret device 6). After the spindle chuck 13 receives the workpiece, the second workpiece spindle device 5 returns to the right side of the machining chamber 10 as shown in Figures 1 and 2, where the specified machining is performed by tools on one or both of the upper and lower turret devices 5, 6.

[0034] Next, the workpiece for which the second machining has been completed is sent by the loader device 8 to the discharge conveyor 9 and discharged outside the machine. While the workpiece is being machined in the machining chamber 10 as described above, the loader device 8 has the robot hand 21 waiting in a storage box 37 formed outside the machining chamber 10. At that time, the door surface 221 of the hand cover 22 integrated with the robot hand 21 closes the opening 19 formed in the partition wall 18, and the storage box 37 is isolated from the machining chamber 10. The workpiece is discharged when the robot hand 21 enters the machining chamber 10 from its standby state in the storage box 37.

[0035] In the loader device 8, the slider 251 moves linearly toward the machining chamber 10 from the standby state shown in Fig. 5 by the output of the Z-axis cylinder 25, and the robot hand 21 moves out of the storage box 37 and into the machining chamber 10 via the shaft 23 connected to the slider 251, as shown in Fig. 4 (see Fig. 1). The robot hand 21 enters the machining chamber 10 in a standby state stored in the storage box 37, and changes its attitude (inclination) so that it can grip the workpiece on the spindle chuck 13.

[0036] The standby posture of the robot hand 21 is maintained with the swivel cylinder 27 in an extended state. Therefore, when the swivel cylinder 27 contracts, the shaft 23 rotates integrally with the link lever 28, changing the tilt of the robot hand 21. At that time, the swivel cylinder 27 pulls the connecting portion by retracting the piston rod 271, thereby rotating the link lever 28. The robot hand 21, which is attached perpendicular to the tip of the shaft 23, rotates due to the output of the swivel cylinder 27, and is changed from the standby posture shown in Figure 4 to the working posture shown in Figure 3 (the same applies to Figure 1).

[0037] Next, when the robot hand 21 grasps a workpiece, the chuck jaws 31 are moved by the output of the advance / retract cylinder 33 to a position where they protrude from the hand cover 22 so that the hand cover 22 does not interfere with the workpiece. Then, when the chuck jaws 31 grasp the workpiece by the output of the open / close cylinder 32, the spindle chuck 13 of the second workpiece spindle device 4 releases the workpiece and moves away in the Z-axis direction. Thereafter, the turning cylinder 27 extends, causing the link lever 28 and shaft 23 to rotate, and the robot hand 21, still grasping the workpiece, is rotated from the working posture shown in FIG. 3 to the standby posture shown in FIG. 4.

[0038] Next, by output of the Z-axis cylinder 25, the robot hand 21 moves from its position in the machining chamber 10 shown in Fig. 4 to the storage box 37 shown in Fig. 5 while still gripping the workpiece, and is stored there. At this time, the door surface 221 of the hand cover 22 closes the opening 19, and the interior of the storage box 37 is isolated from the machining chamber 10. The robot hand 21 that has entered the storage box 37 does not immediately release the workpiece, but continues to grip it until a certain amount of coolant drips from the workpiece. The coolant that drips from the workpiece or the like flows into a coolant receiver provided below the workpiece receiver 51 and is returned to the machining chamber 10.

[0039] Thereafter, the chuck jaws 31 are released, causing the machined workpiece to drop onto the guide plate 38, roll over the workpiece receiver 51, and be placed on the conveyor belt 52 of the discharge conveyor 9. As the conveyor belt 52 is rotating, the workpiece that has fallen onto it is transported to the discharge section 55 and removed from the machine tool 1.

[0040] Therefore, in the machine tool 1 of this embodiment, the loader device 8 provided inside the machine makes it possible to unload a machined workpiece. The loader device 8 stores the standby robot hand 21 not inside the machining chamber 10 but in a storage box 37 outside the machining chamber 20. Moreover, a door surface 221 integrated with the robot hand 21 closes the opening 19 and, together with the partition wall 18, forms the side of the machining chamber 10. Therefore, the robot hand 21 does not become an obstacle inside the machining chamber 10, nor does it interfere with tool replacement or maintenance work performed by an operator inside the machining chamber 10. Furthermore, in the machining chamber 10 with limited space, there is no restriction on arranging various machining devices, such as the second workpiece spindle device 4, in the same area inside the machine.

[0041] The loader device 8 is integrated with the robot hand 21 so that it is covered by the hand cover 22, so that dripping coolant can be prevented from adhering to the robot hand 21 even when the robot hand 21 enters the processing chamber 10. Furthermore, the door surface 221, which is part of the hand cover 22, also functions as an opening / closing door for opening and closing the opening 19, so there is no need to provide an opening / closing mechanism in the narrow interior of the machine. There is also no need to control the opening / closing mechanism.

[0042] Since the storage box 37 is inclined toward the discharge conveyor 9, which is the discharge device, when the robot hand 21, which is in a standby position holding a workpiece and has entered the storage box 37, simply releases the chuck jaws 21, the workpiece rolls down onto the discharge conveyor 9 and is transported outside the machine. Furthermore, the coolant taken out of the machining chamber 10 flows down the inclined surface and into the coolant receiver located below the workpiece receiver 51, and is returned to the machining chamber 10. The workpiece to be discharged is also designed to wait a certain amount of time in the storage box 37 before being discharged, so that the coolant adhering to the workpiece can be removed to a certain extent before being discharged, and the removed coolant can also be returned to the machining chamber 10.

[0043] The loader device 8 has a rodless Z-axis cylinder 25 that moves the robot hand 21 in and out of the machining chamber 10, which reduces the size in the Z-axis direction. Also, a hydraulic cylinder is used for the turning cylinder 27 of the crank mechanism that turns the robot hand 21 so that sufficient force can be output even with a compact configuration. This allows the robot hand 21 fixed to the other end of the shaft 23 to turn even with a link lever 28 that has a short distance from the center of rotation (center line O) to the point of application P.

[0044] While one embodiment of the present invention has been described above, the present invention is not limited thereto and various modifications are possible without departing from the spirit of the present invention. In the above embodiment, the door element is configured by the door surface 221 that is part of the hand cover 22, but the door element may be configured by simply fixing a plate-shaped door corresponding to the door surface 221 without the hand cover surrounding the robot hand 21. In the above embodiment, the storage section is configured by the storage box 37, but it does not necessarily have to be box-shaped. Furthermore, although the machine tool in the above embodiment has been described using a two-turret, two-spindle lathe as an example, the present invention is not limited thereto.

[0045] DESCRIPTION OF SYMBOLS 1...machine tool 3...first workpiece spindle device 4...second workpiece spindle device 5...upper turret device 6...lower turret device 8...loader device 9...discharge conveyor 10...machining chamber 11, 13...spindle chuck 15, 16...turret tool rest 18...partition wall 19...opening 20...outside of machining chamber 21...robot hand 22...hand cover 23...shaft 25...Z-axis cylinder 27...turning cylinder 28...link lever 37...storage box

Claims

1. A machine tool comprising: a discharge device arranged outside a machining chamber separated by a partition from a machining chamber in which a workpiece held by a spindle chuck is machined; and a loader device which transports the machined workpiece from the spindle chuck to the discharge device, wherein the loader device has: a robot hand which grasps the workpiece on the spindle chuck; a drive device which causes the robot hand to move between the machining chamber and outside the machining chamber and to receive the workpiece; and a door member formed integrally with the robot hand which closes an opening formed in the partition by moving from the machining chamber to outside the machining chamber.

2. A machine tool as described in claim 1, further comprising a storage section in which the robot hand is positioned, the storage section being disposed outside the machining chamber of the opening formed in the partition wall, so that the workpiece is continuously discharged to the discharge device.

3. A machine tool according to claim 1 or 2, wherein the door member is a plate material.

4. A machine tool as claimed in claim 1 or 2, wherein the door member is part of a housing surrounding the robot hand.

5. A machine tool as described in claim 2, wherein the storage section is inclined so that the discharge device side is downward, a guide member continuing to the discharge device is provided on the lower side of the inclination, and the robot hand is stored in the storage section so that its chuck jaws are positioned on the lower side of the inclination.

6. A machine tool as described in claim 1, wherein the robot hand has an opening / closing mechanism for opening and closing a pair of chuck jaws, and an advancing / retreating mechanism for advancing and retracting the chuck jaws.

7. A machine tool as described in claim 6, wherein the driving device includes a moving mechanism that moves the robot hand between the machining chamber and the outside of the machining chamber via a shaft that supports the robot hand, and a rotating mechanism that rotates the robot hand to a position to receive the workpiece held by the spindle chuck.

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