machine tool

Abstract

Machine tool that includes: a workpiece storage unit (2) with a plurality of receiving spaces for receiving workpieces (4), and a processing machine (3) for processing a workpiece (4) which is fed from one of the receiving spaces, wherein the workpiece storage unit (2) is constructed in such a way that the size of each receiving space can be changed, characterized in that the workpiece storage unit (2) comprises a workpiece exchange device (5) which feeds a workpiece (4) from one of the receiving spaces to the processing machine (3) and places a workpiece (4) processed by the processing machine (3) in one of the receiving spaces, wherein the size of each receiving space is changed using the workpiece exchange device (5).

Description

[0001] The present invention relates to a machine tool comprising a processing machine for processing a workpiece and a workpiece storage unit for receiving workpieces, and in particular the sizes of workpiece receiving spaces in the workpiece storage unit.

[0002] For example, Japanese patent JP 3 047 847 B2 discloses a workpiece storage unit of this type in which pallet trays are arranged in a ring shape at different heights along the circumference, with a support arm, which can move vertically, rotate about a vertical axis, and move horizontally, located in a central part of the workpiece storage unit. Another example of a workpiece changer with an integrated workpiece magazine is disclosed in DE 298 14 126 U1. JP H05-68 917 U discloses yet another example of a workpiece storage unit.

[0003] In a conventional workpiece storage unit, the receiving areas formed by the pallet trays have a fixed size, meaning the size of the workpieces that can be received is also predetermined. Therefore, if workpieces of other sizes are to be received, a new workpiece storage unit must be provided.

[0004] It is therefore an object of the present invention to provide a machine tool that can accommodate workpieces of different sizes in a single workpiece storage unit, so that no new workpiece storage unit is required.

[0005] In a machine tool according to the present invention, which comprises a workpiece storage unit with a plurality of receiving spaces for receiving workpieces and a processing machine for processing a workpiece supplied from one of the receiving spaces, the workpiece storage unit is constructed in such a way that the size of each receiving space can be changed.

[0006] Because, according to the present invention, the receiving spaces of the workpiece storage unit can be changed, workpieces of different sizes can be received in the same workpiece storage unit by changing the size of the receiving spaces in accordance with the size of the workpieces. In this way, different types of workpieces can be received.

[0007] According to the present invention, the workpiece storage unit has a workpiece exchange device that feeds a workpiece from one of the receiving spaces to the processing machine and places a workpiece processed by the processing unit in one of the receiving spaces, wherein the size of the receiving spaces is changed using the workpiece exchange device.

[0008] Since the receiving spaces are changed by the workpiece exchange device, which is intended to replace an unprocessed workpiece from one of the receiving spaces with a processed workpiece, the receiving spaces can be changed without the need to provide a new receiving space change mechanism.

[0009] In a preferred embodiment of the present invention, the workpiece storage unit comprises a plurality of support rods extending in the vertical direction and trays arranged on the support rods at several levels, wherein at least some of the trays can be removed and wherein the size of each receiving space is changed by the workpiece exchange device by attaching / removing the removable trays to / from the support rods or by moving the attachment position of the removable trays upwards or downwards.

[0010] Because, according to the preferred embodiment, the receiving spaces are formed by arranging trays at several heights on the support rods and at least some of the trays can be removed, and because the receiving spaces are changed by the workpiece exchange device attaching / removing the removable trays to / from the support rods or moving the trays up or down, the receiving spaces can be changed without making the overall machine structure more complex.

[0011] In a further preferred embodiment of the present invention, a workpiece detection device is provided for detecting the size of a workpiece supplied to the workpiece supply unit, wherein the workpiece exchange device accommodates the supplied workpiece in a receiving space, the size of which corresponds to the size of the workpiece detected by the workpiece detection device.

[0012] Because, according to a further preferred embodiment, the workpiece detection device is provided for detecting the size of a workpiece fed to the workpiece storage unit, and the fed workpiece is automatically placed by the workpiece exchange unit in a receiving chamber whose size corresponds to the size of the workpiece detected by the workpiece detection device, the operator does not need to specify the size of the workpiece via a control panel. This simplifies the feeding of workpieces to the workpiece storage unit. Fig. Figure 1 is a perspective overall view of a machine tool according to an embodiment of the present invention. Fig. Figure 2 is a top view of the machine tool. Fig. Figure 3 is a perspective view of a workpiece exchange device of the machine tool. Fig. Figure 4 is a top view of a workpiece exchange arm located in a front position. Fig. Figure 5 is a side view of the workpiece exchange arm. Fig. Figure 6 is a side view of the workpiece exchange arm, which is in a retracted position. Fig. Figure 7 is a perspective view showing the state of a removable tray mounted on retaining clips. Fig. Figure 8 is a side view of a preparation station. Fig. Figure 9 is a top view of the workpiece exchange arm and the storage area in a state where the storage area is being moved by the workpiece exchange device. Fig. Figure 10 is a side view of a state in which a processed workpiece is removed from a worktable of a processing machine. Fig. Figure 11 is a side view of a state in which the processed workpiece has been removed from the workbench. Fig. Figure 12 is a top view illustrating an operation for placing the processed workpiece on a shelf. Fig. Figure 13 is a top view illustrating an operation to remove an unprocessed workpiece from a storage area. Fig. Figure 14 is a top view illustrating an operation for feeding the unprocessed workpiece to the worktable of the processing machine. Fig. Figure 15 is a perspective view showing a state in which the removable tray is removed from the retaining clips. Fig. Figure 16 is a perspective view showing a state in which the removable tray has been removed from the retaining clips. Fig. Figure 17 is a perspective view showing a state in which the removable tray is attached to an upper bracket.

[0013] In the following, an embodiment of the present invention is described with reference to the accompanying drawings.

[0014] Fig. Figures 1 to 17 are views showing a machine tool according to the embodiment of the present invention.

[0015] In the figures, reference numeral 1 denotes a machine tool. This machine tool 1 comprises a workpiece storage unit 2 for storing a large number of workpieces 4 and a processing machine 3 for performing machining operations on a workpiece 4 supplied by the workpiece storage unit 2.

[0016] The processing machine 3 comprises a worktable 3b, on which the workpiece 4 is mounted, and a processing machine body 3a, which performs various types of processing on the workpiece 4 mounted on the worktable 3b. The reference numeral 3c indicates a structure formed around the perimeter of the processing machine body 3a and the worktable 3b.

[0017] The workpiece storage unit 2 comprises a storage body 2a, which has a substantially cylindrical shape, and a workpiece exchange device 5, which is arranged in a central part of the storage body 2a. The storage body 2a comprises a plurality of retaining rods 7, which are arranged annularly along the circumference and extend in a vertical direction, trays 6-1 to 6-10, which are held at several levels between adjacent retaining rods 7, 7, and a preparation station 8, which is arranged at a machine front F.

[0018] The shelves 6-1, 6-3, ... 6-9 on odd-numbered levels of shelves 6-1 to 6-10 are fixed by clamps 7a between the support bars 7, 7, while the shelves 6-2, 6-4, ... 6-10 on the even-numbered levels are held removable between the support bars 7, 7.

[0019] In particular, the front and rear retaining clips 7b, 7c are fixed to the support rods 7. The rear retaining clips 7c, 7c hold the left and right rear sections 6', 6' of the shelves 6-2, 6-4, ... 6-10, and the front retaining clips 7b, 7b hold the left and right front sections 6", 6" of the shelves 6-2, 6-4, ... 6-10. Furthermore, a pin hole 7d is formed in each rear retaining clip 7c, into which a retaining pin 6a is inserted in the shelves 6-2, 6-4, ... 6-10. A positioning projection 7e is also provided, which engages in a positioning hole 6c in the shelves 6-2, 6-4, ... 6-10.

[0020] The preparation station 8 has a fixed table 8a that supports a rotary table 26, with a rotary actuator 24 arranged below the rotary table 26 of the fixed table 8a. An output gear 24a of the rotary actuator 24 engages with an input gear 26a of the rotary table 26. A workpiece 4 is mounted on a pallet 23, which is mounted on the rotary table 26. The pallet 23 and the workpiece 4 are secured by a screw or similar fastener, while the pallet 23 and the workpiece 4 are rotated by the rotary table 26. Depending on the shape or other property of the workpiece, the pallet 23 and the workpiece 4 can also be secured without rotating the rotary table 26.

[0021] Furthermore, a workpiece detection sensor 25, which detects the size of a workpiece by rotating the rotary table 26 once, is arranged above the fixed table 8a. The workpiece detection sensor 25 is formed by a CCD camera, whereby the size of a workpiece is detected by processing an image from this camera.

[0022] The workpiece exchange device 5 comprises a workpiece exchange arm 17, which is designed to move forward or backward in a horizontal direction, and a rotary and lifting mechanism 9, which can rotate the workpiece exchange arm 17 about a vertical axis and raise and lower the arm in the vertical direction.

[0023] The rotary and lifting mechanism 9 comprises a base 9a, which is driven by a rotary drive motor (not shown) for rotation about a vertical axis; a pair of lifting guide rods 10, 10, which are fixed such that they extend vertically from an upper surface of the base 9a; a lifting frame 14, which is held by the pair of lifting guide rods 10, 10, so that it can be raised and lowered; a ball screw shaft 12, which is screwed through a nut link 15 fixed to the lifting frame 14; and a lifting drive motor 13, which is arranged on the base 9a to drive the ball screw shaft 12. The rotation of the lifting drive motor 12 is transmitted to the ball screw shaft 12 via a gear mechanism arranged in a gear housing 11.

[0024] The workpiece exchange arm 17 comprises an arm holding table 19, which is fixed to and held on the lifting frame 14, and an arm body 17a, which is held by the arm holding table 19 such that it can be moved forwards and backwards in the horizontal direction. A pair of left and right guide rails 16, 16 are arranged on the arm holding table 19, and linear guides 16a on a lower surface of the arm body 17a slide on the guide rails 16, 16. Furthermore, a forward / reverse drive motor 18, which drives the arm body 17a, is fixed to the arm holding table 19. A gear 18a, which is fixed to an output shaft of the forward / reverse drive motor 18, engages with a rack 17b, which is fixed to a side surface of the arm body 17a.

[0025] A fork 17c for holding the pallet 23 is formed on a front end part of the arm body 17a. Fork tines 17d for insertion into the pin holes 6b in the removable trays 6-2, 6-4, ... 6-10 project upwards from a base part of the fork 17c. Furthermore, a switch 20 for detecting the presence of a tray is arranged on the base part of the fork 17c.

[0026] In the setup described above, the workpiece exchange arm 17 rotates around the vertical axis when the rotary drive motor (not shown) rotates the base 9a, moves up or down when the lifting drive motor 13 rotates the ball screw shaft 12, and moves backward in the horizontal direction when the forward / reverse drive motor 18 rotates the gear 18a.

[0027] First, an operation for exchanging a processed workpiece 4a for an unprocessed workpiece 4b in a predetermined receiving space of the workpiece storage unit 2 is described below.

[0028] When the processing of the workpiece is complete, a closure 2b at a boundary between the processing machine 3 and the workpiece storage unit 2 is opened and the arm body 17a extends the forks 17c, 17c to both sides of the pallet mounted on the worktable 3b of the processing machine 3 (see Fig. 4, Fig. 5 and Fig. 10). Then the entire workpiece exchange arm 17 moves upwards in the vertical direction to the processed workpiece 4a (see Fig. 11) to lift, and the arm body 17a moves backward to move the processed workpiece 4a from the processing machine 3 to the side of the workpiece storage unit 2.

[0029] Then the rotary drive motor (not shown) rotates the base 9a around the vertical axis so that the workpiece exchange arm 17 is at the angular position corresponding to the tray 6A on which the processed workpiece 4a is temporarily placed, and the lifting drive motor 13 rotates the ball screw shaft 12 so that the workpiece exchange arm 17 is at the vertical position corresponding to the tray 6A for temporary placement. The arm body 17a moves forward horizontally to the position corresponding to the tray 6A for temporary placement, and then the entire workpiece exchange arm 17 moves downward vertically to transfer the processed workpiece 4a onto the tray 6A (see Fig. 12). Then the arm body 17a moves back to its starting position in the horizontal direction.

[0030] Furthermore, the workpiece exchange arm 17 is driven to rotate about the vertical axis in order to be positioned at an angle corresponding to a tray 6B on which the unprocessed workpiece 4b is temporarily placed. The arm body 17a extends the forks 17c to the left and right sides of the pallet (not shown) fixed to the unprocessed workpiece 4b, and the entire workpiece exchange arm 17 moves upwards in the vertical direction to lift the unprocessed workpiece 4b upwards and thereby remove it from the tray 6B (see Fig. 13). The arm body 17a then moves back to its starting position in the horizontal direction.

[0031] Then the workpiece exchange device 5 is driven for a rotation about the vertical axis in order to be moved to the angular position corresponding to the worktable 3b of the processing machine 3, the arm body 17a moves forward in the horizontal direction so that the unprocessed workpiece 4b is positioned above the worktable 3b (see Fig. 14), and the entire workpiece exchange device 5 moves downwards in the vertical direction to transfer the unprocessed workpiece 4b onto the worktable 3b. The arm body 17a moves backwards in the horizontal direction to its starting position, and the gate 2b closes. Processing can then be restarted.

[0032] The following describes an operation to enlarge a receiving space in the workpiece storage unit 2, which is carried out, for example, by moving the removable tray 6-6 from the lower, front and rear retaining clamp 7b, 7c to an upper clamp 27.

[0033] The rotary drive motor rotates the base 9a around the vertical axis, so that the workpiece exchange arm 17 is moved to an angular position corresponding to a specific column of the trays. The linear drive motor 13 rotates the ball screw shaft 12, so that the arm is moved to a height position corresponding to tray 6-6 to change the holding area. Then the arm body 17a moves forward horizontally so that the fork 17c is positioned under tray 6-6. Finally, the entire workpiece exchange arm 17 moves upward so that the fork pins 17d, 17d engage in the pin holes 6b, 6b (see Fig. 15).

[0034] The entire workpiece exchange arm 17 moves further upwards to remove the tray 6-6 from the front and rear clamps 7b, 7c. And the arm body 17a moves horizontally backwards to its starting position (see Fig. 16).

[0035] The lifting drive motor 13 drives the workpiece exchange arm 17 upwards to a height position corresponding to the upper clamp 27. The arm body 17a then moves forwards horizontally to a position corresponding to the upper clamp 27. The entire workpiece exchange arm 17 then moves downwards so that the retaining pins 6a engage in the pin holes 7d and the positioning projections 7e engage in the positioning holes 6c. In this way, the support 6-6 is mounted on the upper clamp 27, after which the arm body 17a moves back horizontally to its starting position (see Fig.17).

[0036] Because in this embodiment the trays of the workpiece storage unit 2 comprise the fixed trays 6-1, 6-3, ... 6-9 and the removable trays 6-2, 6-4, ... 6-10, and the removable trays can be moved up or down, the size of each receiving space can be changed so that workpieces of different sizes can be held in the same workpiece receiving unit. In this way, more different types of workpieces can be held.

[0037] And because workpiece exchange device 5 is used to replace an unprocessed workpiece 4b in a receiving chamber with a processed workpiece 4a, in order to move the storage trays and thereby change the receiving chamber, the receiving chambers can be changed without having to provide a new receiving chamber change mechanism. In this way, a more complex design of the entire machine can be avoided.

[0038] And because a setup for enlarging the recording space is provided by moving a removable shelf to the upper clamp 27 above the shelf, no separate recording space needs to be provided for the removed shelf. In this way, the recording space can be changed within a short time.

[0039] Because the workpiece detection sensor 25 is designed to detect the size of the workpiece 4 at the preparation station 8, and the workpiece 4 is automatically placed in the receiving chamber by the workpiece exchange arm 17 according to the size detected by the workpiece detection sensor 25, the operator does not need to perform any operation to specify the workpiece size at a control panel. This simplifies the workpiece feeding operation and avoids human errors such as incorrectly specifying the workpiece size.

[0040] It should be noted that the above embodiment describes a case in which the receiving space is increased by moving the shelf upwards. However, the receiving space can also be reduced by adding an additional shelf. In this way, the number of receiving spaces can be increased.

[0041] The invention can also be implemented through other embodiments without thereby departing from the scope of the invention.

[0042] The embodiment described above is therefore to be understood as exemplary and not as limiting, whereby the scope of the invention is defined by the attached claims and not by the preceding description.

Claims

[1] Machine tool comprising: a workpiece storage unit (2) with a plurality of receiving spaces for receiving workpieces (4), and a processing machine (3) for processing a workpiece (4) which is fed from one of the receiving spaces, wherein the workpiece storage unit (2) is designed such that the size of each receiving space can be changed, characterized by , that the workpiece storage unit (2) comprises a workpiece exchange device (5) which feeds a workpiece (4) from one of the receiving spaces to the processing machine (3) and places a workpiece (4) processed by the processing machine (3) in one of the receiving spaces, the size of each receiving space being changed using the workpiece exchange device (5). [2] Machine tool according to claim 1, characterized by, that the workpiece storage unit (2) comprises a plurality of support bars (7) extending in a vertical direction and trays (6-1 to 6-10) arranged in several levels on the support bars (7) and wherein at least some of the trays (6-2, 6-4, ... 6-10) can be removed, the size of each receiving space being changed by the workpiece exchange device (5) attaching / removing the removable trays (6-2, 6-4, ... 6-10) to / from the support bars (7) or by moving the attachment position of the same up or down. [3] Machine tool according to claim 1 or 2, furthermore characterized by : a workpiece detection device (25) for detecting the size of a workpiece (4) that is fed to the workpiece storage unit (2), wherein the workpiece exchange device (5) accommodates the supplied workpiece (4) in a receiving space the size of which corresponds to the size of the workpiece (4) detected by the workpiece detection device (25).

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