JP3777905B2 - Workpiece clamping device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a clamp device for fixing a workpiece to a mounting base suitable for use in, for example, a machine tool or an assembly machine.
[0002]
[Prior art]
As shown in FIG. 7, such a workpiece clamping device has a plurality of positioning pins 102 and a shape of the workpiece W on the upper surface of the mounting base 101 fixed perpendicularly on the mounting surface of the pallet P. A plurality of reference sheets 103 are attached, and the workpiece W positioned by the positioning pins 102 and having a seating surface in close contact with the reference sheet 103 is transferred to the workpieces by a plurality of arm type clampers 104. The surface opposite to the seating surface of W is clamped and fixed against the mounting base 101 by pressing.
[0003]
[Problems to be solved by the invention]
When such a conventional workpiece clamping device is used, the surface clamped by the clamper and the surface close to the clamper can be partially processed, but the entire area of the surface cannot be processed. The surface that can be processed by the clamping operation is limited. In order to process all other surfaces except the seating surface, a plurality of processes are required, and a jig plate corresponding to each process is required.
[0004]
An object of the present invention is to solve the above-mentioned problem and to provide a workpiece clamping device with excellent productivity capable of machining all other surfaces except a seating surface by a single clamping operation.
[0005]
[Means for Solving the Problems]
The workpiece clamping device according to claim 1, wherein a workpiece having an R-axis rotary table rotatable and positioned around an R axis orthogonal to the C axis on a C axis rotary table rotatable and positioned around a C axis. A workpiece clamping device for fixing a workpiece, which is disposed on a table and has a positioning hole formed on a seating surface, to the mounting table, a mounting table having a receiving surface for receiving the seating surface of the workpiece, A collet that projects into the positioning hole of the workpiece, a pull rod that is disposed in the collet so as to be movable forward and backward, and expands the collet, and an actuator that moves the pull rod forward and backward. The pull rod is moved in a direction to be pulled with respect to the receiving surface by expanding the collet so that the outer periphery of the collet is within the positioning hole. The workpiece is positioned and clamped at the same time by closely fitting to a surface, and a polygonal polyhedron is formed on the mounting base, and each polygonal polyhedron is formed on the mounting base. A clamp mechanism including the collet, the pull rod, and the actuator is provided on a surface, and the mounting base is held on the R-axis rotary table. According to the first aspect of the present invention, since clamping is performed using the positioning holes formed on the seating surface of the workpiece, all surfaces other than the seating surface can be processed by a single clamping operation. Moreover, since positioning and clamping are performed simultaneously, the clamping operation is fast.
[0006]
In the invention of claim 1, it may be a collet impossible move forward and backward, but the pre-Symbol collet while the retractable movement, may be provided a spring for biasing the collet in a direction projecting from the mount . In this way, by moving the pull rod in the direction in which the pull rod is retracted with respect to the receiving surface, the collet is prevented from being pulled in by the spring until the collet clamps the positioning hole of the workpiece. If there is a gap between the seating surface of the workpiece and the receiving surface of the mounting base after the workpiece is securely and closely fitted and clamped, the workpiece is lowered together with the collet, and the workpiece An object can be brought into close contact with the receiving surface of the mounting base.
[0008]
According to the invention 請 Motomeko 1, to form a polygonal pyramid shaped polyhedron mount, by providing the workpiece clamping mechanism on each side of the polygonal cone-shaped polyhedron, each of the polygonal cone-shaped polyhedron It is possible to clamp the workpiece on the surface.
[0009]
Further , since the workpiece clamping device is installed on a workpiece table having a two-axis rotary table orthogonal to each other , the workpiece is clamped on each surface of a polygonal polyhedron by changing the posture of the workpiece with respect to the tool. A workpiece can be continuously machined with a single tool spindle.
[0010]
The invention of claim 2, in which the workpiece clamping device according to claim 1, provided on the detachable a workpiece clamping device on a machine tool of the workpiece table pallet. According to invention of Claim 2 , since the said workpiece clamping apparatus was provided in the pallet which can be attached or detached on the workpiece table of a machine tool, the workpiece to the said workpiece table is conveyed by the conveying apparatus which conveys the said pallet. It is possible to automate loading and unloading.
[0011]
A third aspect of the present invention, the workpiece clamping device according to claim 2, the coupler that allows disconnecting the hydraulic fluid supply source for supplying pressure oil to the actuator and the actuator, when disconnecting the coupler, Clamping force holding means for urging the pull rod in a direction in which the collet expands is provided. According to the invention of claim 3 , there is provided a coupler capable of separating the actuator and the pressure oil supply source, and clamping force holding means for biasing the pull rod in a direction in which the collet expands when the coupler is disconnected. Therefore, the workpiece can be clamped even if the actuator and the pressure oil supply source are separated.
[0012]
As such a clamping force holding means, for example, an accumulator provided on the pressure oil supply path to the actuator, or a spring that constantly urges the pull rod in the direction in which the collet expands can be used.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a spindle head 7 and a workpiece table 11 are arranged opposite to each other on a bed 5 that is a machine tool base.
[0014]
An X-axis table 6 that is moved by an X-axis feed motor 8 is installed on the bed 5 along an X-axis guide rail 6a extending in the X-axis direction (perpendicular to the paper surface in FIG. 1). On this X-axis table 6, a spindle head is moved by a Z-axis feed motor (not shown) along a Z-axis guide rail 7b extending in the Z-axis direction (left-right direction in FIG. 1) orthogonal to the X-axis direction. 7 is provided, and the spindle head 7 is rotatably supported by a spindle 7a that is rotatably driven with a tool T attached to the tip.
[0015]
A front surface of the bed 5 is provided with a Y-axis table 10 that is moved in the Y-axis direction (vertical direction in FIG. 1) by a motor (not shown). On the Y-axis table 10, a workpiece table 11 is provided. Is provided. This workpiece table 11 is provided with a C-axis table 12 that can be rotated and positioned by a rotary indexing device 12a around a C-axis parallel to the Y-axis. A pallet holding member 13 that holds the pallet P so as to be freely rotated and positioned by the rotary indexing device 13a is provided around the R axis that is orthogonal.
[0016]
Next, the rotation index devices 12a and 13a that perform the rotation and positioning operations of the C-axis table 12 and the pallet holding member 13 that holds the pallet P will be described. Since the rotary indexing devices 12a and 13a have the same configuration, only the rotary indexing device 12a will be described.
[0017]
In FIG. 2, a first turntable 21 (corresponding to a shaft having a cylindrical portion) is provided at the upper end of a Y-axis table 10 via a cross roller bearing (not shown) so as to be indexable by a built-in motor 22. That is, the rotation index of the first turntable 21 rotated by the built-in motor 22 is controlled by a position detector (not shown) arranged in the vicinity of the first turntable 21.
[0018]
A clamp mechanism 23 capable of clamping and unclamping is installed at the tip of the Y-axis table 10, and the first turntable 21 that has been indexed by rotation is clamped and fixed.
[0019]
A C-axis table 12 is fixed on the first turntable 21. Although not shown, a pallet is placed on the second turntable (same configuration as the first turntable) of the rotary indexing device 13a on the C-axis table 12 whose rotation axis is orthogonal to the first turntable 21. A pallet holding member 13 for holding P is fixed.
[0020]
The present invention is characterized by a workpiece clamping device mounted on the pallet P. Next, the workpiece clamping device will be described.
As shown in FIG. 3, a pyramid-shaped mounting base 51 is seated on the mounting surface of the pallet P that is engaged with the pallet holding member 13 of the workpiece table 11 by the T-shaped groove 50a. It is fixed by multiple bolts. This pyramidal polyhedron has an internal space similar to the outer diameter.
[0021]
A plurality of reference sheets 52 that match the shape of the workpiece W are provided on each receiving surface of the mounting base 51, and a plurality of clamp mechanisms 53 whose leading ends protrude from the receiving surface are built in the mounting base 51. Has been.
[0022]
As shown in FIG. 4, the clamp mechanism 53 includes a collet clamper 54, a pull rod 55, and an actuator 57. The actuator 57 is a surface opposite to the receiving surface of the mounting base 51 (inside the pyramidal polyhedron). Space).
[0023]
A through hole 51 a is formed in the mounting base 51, and a collet clamper 54 having a tip protruding from the receiving surface of the mounting base 51 through the through hole 51 a is installed. The pull rod 55 is inserted so as to be able to move forward and backward. A collet portion 54a, which is a cylindrical sleeve having a plurality of slits in the axial direction, is formed at the tip of the collet clamper 54, and an anti-skid groove is formed on the outer periphery of the collet portion 54a.
[0024]
The collet portion 54a of the collet clamper 54 is usually smaller than the hole diameter of the positioning hole 71 of the workpiece W, and the positioning hole 71 formed on the seating surface of the workpiece W is fitted therein. With the positioning hole 71 fitted, the pull rod 55 is retracted (downward in FIG. 4) to expand the collet portion 54a so that the collet portion 54a is closely fitted to the positioning hole 71 of the workpiece W. Is set to
[0025]
At the base end of the collet clamper 54, a flange portion 54 b is formed in the outer peripheral direction, and this flange portion 54 b is accommodated in an accommodation hole formed in the end surface of the cylinder 58.
A disc spring 56 is preferably installed at the rear of the collet clamper 54. The collet clamper 54 is normally biased in the forward direction (upward in FIG. 4) by the biasing force of the disc spring 56, The collet clamper 54 is installed in a state in which the flange portion 54 b is in contact with the surface opposite to the receiving surface of the mounting base 51.
[0026]
The disc spring 56 prevents the collet clamper 54 from descending until the workpiece W is clamped by expanding the collet clamp 54a of the collet clamper 54 when the pull rod 55 is retracted. Is tightly fitted into the positioning hole 71 of the workpiece W, and after the workpiece W is securely clamped, when there is a gap between the seating surface of the workpiece W and the reference sheet 52, The spring force is set such that the collet clamper 54 is allowed to descend and the workpiece W is brought into close contact with the reference sheet 52.
[0027]
57 is an actuator for advancing and retracting the pull rod 55, and its piston 59 is fixed to the rear end of the pull rod 55 inserted through the center of the cylinder 58 by a nut 60. It is fixed to the mounting base 51 by a bolt 62 that passes through a cap body 61 that is fitted to the end.
[0028]
The cylinder 58 is formed with a clamping pressure oil supply path 63 and an unclamping pressure oil supply path 64, and both the pressure oil supply paths 63 and 64 are connected to a coupler 66 to supply pressure oil from the outside. Emissions are made. Further, an accumulator 67 as a clamping force holding means is connected on the clamping pressure oil supply path 63. The accumulator 67 is a clamping force holding means that functions to hold the clamping force when the coupler 66 is removed together with the workpiece clamping device. The coupler 66 is preferably a quick joint type, but may be, for example, a screw-type connection means.
[0029]
Next, the operation of the workpiece clamping device according to the embodiment of the present invention having the above configuration will be described.
When clamping the workpiece W, as shown on the left side of the center line in FIG. 4, a positioning hole 71 formed on the seating surface of the workpiece W is formed on the collet portion 54 a of the collet clamper 54 protruding on the mounting base 51. The workpiece W is positioned with respect to the mounting base 51 by being brought into contact with a plurality of reference sheets 52 that match the shape of the workpiece W provided on the receiving surface of the mounting base 51.
[0030]
Next, the coupler 66 is connected to supply the pressure oil to the clamping pressure oil supply path 63 and discharge the pressure oil from the unclamping pressure oil supply path 64 to operate the actuator 57 in FIG. As shown on the right side of the center line, the pull rod 55 is retracted in the backward direction (downward in FIG. 4), and the collet portion 54a formed at the tip of the collet clamper 54 is expanded in the outer peripheral direction, thereby positioning holes 71 of the workpiece W. And the workpiece W is fixed on the mounting base 51. In this case, the disc spring 56 prevents the collet clamper 54 from descending. If there is a gap between the seating surface of the workpiece W and the reference sheet 52, the collet clamper 54 is retracted in the backward direction against the biasing force of the disc spring 56 installed at the rear of the collet clamper 54. The workpiece W is brought into close contact with a reference sheet 52 provided on the receiving surface of the mounting base 51. Such clamping and unclamping operations are performed when the pallet P is in the workpiece setup station. After this operation, the coupler 66 is removed and the pallet P is carried into the machine tool.
[0031]
The unclamping operation of the workpiece W is performed by connecting the coupler 66 to supply the pressure oil to the unclamping pressure oil supply path 64 and discharge the pressure oil from the clamping pressure oil supply path 63. By operating, as shown on the left side of the center line in FIG. 4, the pull rod 55 is pushed forward (upward in FIG. 4) to clamp the workpiece W at the collet portion 54 a formed at the tip of the collet clamper 54. Is released. When the unclamping operation of the workpiece W is completed, the coupler 66 is removed.
[0032]
As shown in FIG. 1, after the pallet P is transported to the machine tool side by a transport device described later, the machine tool 1 moves the tool T by the feed operation of the X-axis table 6, the spindle head 7, and the Y-axis table 10. The workpiece table 11 is moved in a three-dimensional direction orthogonal to the workpiece W, and the posture of the workpiece W with respect to the tool T is changed by the rotation of the C-axis table 12 and the pallet holding member 13 of the workpiece table 11. The workpiece W mounted on the pallet P engaged with the pallet holding member 13 is subjected to various processes. In this case, as shown in FIG. 2, when the turntable 21 is indexed and rotated, the turntable 21 is unclamped by the clamp member 23, and the turntable 21 is rotationally driven by the built-in motor 22. The position is controlled to a predetermined rotation index position by a position detector, and the turntable 21 is clamped by the clamp member 23.
[0033]
Next, a second embodiment of the workpiece clamping device according to the present invention will be described. In the workpiece clamping device described in FIG. 4, the workpiece W is clamped and unclamped by hydraulic pressure. In this embodiment, as shown in FIG. 5, the workpiece clamping device is fixed to the rear end of the pull rod 55. By installing a disc spring 65 on the piston 59 that moves the pull rod 55 forward and backward, the pull rod 55 is retracted and clamped by the biasing force of the disc spring 65, and only the unclamp is hydraulically performed. Is also possible. The disc spring 65 is clamping force holding means that functions to hold the clamping force.
[0034]
The workpiece clamping device described in the above embodiment can automate the attachment and detachment of the workpiece W to / from the workpiece table of a plurality of machine tools in a production system with a conveying device. In this system, as shown in FIG. 6, machine tools 1, 2, 3 are arranged at intervals along the conveyance direction of the workpiece W. Above each machine tool 1, 2, 3, there is provided a transport device composed of two guide rails 43, 44 and transport heads 45, 46, 47 that travel on the guide rails 43, 44. Yes. The transport heads 45, 46, 47 grip a pallet (not shown) that clamps the workpiece W by a pair of gripping claws 48 that are opened and closed by a motor (not shown), and transport it between the machine tools 1, 2, 3. Is supposed to do.
[0035]
More specifically, as shown in FIGS. 3 and 6, in the machine tools 1, 2, and 3, the transport head 45 that grips the pallet P by the pair of grip claws 48 is moved in the transport direction of the workpiece W, thereby The pallet P is carried into the workpiece table 11 by engaging the T-shaped groove 50 a formed in the pallet P and extending in the conveying direction with the pallet holding member 13 positioned in the horizontal state of the workpiece table 11. To do. Thereafter, the pair of gripping claws 48 of the transport head 45 are opened to release the grip of the pallet P, and machining is performed in each of the machine tools 1, 2, and 3. During this processing, the accumulator 67 holds the clamping force.
[0036]
Each time the machining in each machine tool 1, 2, 3 is completed, the pallet holding member 13 is returned to the horizontal state, and the pallet P engaged with the workpiece table 11 is moved by the pair of gripping claws 48 of the transport head 45. By gripping and moving the transfer head 45 in the transfer direction of the workpiece W, the T-shaped groove 50a extending in the transfer direction formed on the pallet P is detached from the pallet holding member 13 of the workpiece table 11. And move to the next machine tool.
[0037]
(Other variations)
In the workpiece clamping device described in the above embodiment, the mounting base forms a pyramid-shaped polyhedron (a quadrangular pyramid), but it may be a triangular pyramid, a pentagonal pyramid, a hexagonal pyramid, or the like. Moreover, you may provide the workpiece clamp mechanism of the said embodiment on the single side | surface or both surfaces of the mounting base of the pallet P demonstrated by the prior art.
[0038]
Moreover, although the workpiece clamp apparatus demonstrated by the said embodiment is attached on the pallet, it is also possible to attach directly to the workpiece table of a machine tool.
[0039]
In the workpiece clamping device described in the above embodiment, the workpiece is clamped by two workpiece clamping mechanisms provided on each surface of the mounting base. However, the workpiece clamping mechanism provided on each surface of the mounting base is The number may be three, four, etc. Further, a large diameter collet clamper may be provided in at least one workpiece clamping mechanism to generate a larger clamping force, and the remaining workpiece clamping mechanism may be a small diameter collet clamper. One may be a workpiece clamping mechanism and the other may be a small-diameter positioning pin for rotation prevention.
[0040]
【The invention's effect】
According to the first aspect of the present invention, since clamping is performed using the positioning hole formed on the seating surface of the workpiece, all surfaces other than the seating surface can be processed by a single clamping operation, and positioning is performed. And since clamping can be performed by a single clamping operation, it is excellent in productivity.
[0041]
Furthermore, if the collet can be moved forward and backward, and if a spring is installed that urges the collet in a direction that protrudes from the mounting base , the collet can be positioned by moving the pull rod in the direction in which it is pulled into the receiving surface. Until the hole is clamped, the collet is prevented from being pulled in by a spring. After the collet is securely fitted into the positioning hole and the workpiece is clamped, the workpiece seating surface and the mounting base are received. When there is a gap between the workpiece and the collet, the workpiece can be lowered and the workpiece can be brought into close contact with the receiving surface of the mounting base. high.
[0043]
Further , a polygonal polyhedron is formed on the mounting base, and a workpiece clamping mechanism is provided on each surface of the polygonal polyhedron, whereby the workpiece is clamped on each surface of the polygonal polyhedron. Is possible and has excellent productivity.
[0044]
Further , since the workpiece clamping device is installed on a workpiece table having a two-axis rotary table orthogonal to each other , the posture of the workpiece with respect to the tool is changed to be clamped on each surface of a polygonal polyhedron. The workpiece can be continuously machined with a single tool spindle, and has excellent productivity.
[0045]
According to the second aspect of the present invention, since the workpiece clamping device of the present invention is provided on a pallet that can be attached to and detached from the workpiece table of a machine tool, the workpiece can be applied to the workpiece table by a conveying device that conveys the pallet. It is possible to automate the loading and unloading of goods, and it is excellent in productivity.
[0046]
According to the invention of claim 3 , since the coupler that makes it possible to disconnect the pressure oil supply source and the clamping force holding means that urges the pull rod in the direction in which the collet expands when the coupler is disconnected, Even when the pressure oil supply source is disconnected, the workpiece can be clamped, and the workpiece clamping device can be downsized.
[Brief description of the drawings]
FIG. 1 is a side view of a machine tool in which a workpiece clamping device of the present invention is used.
FIG. 2 is a partial cross-sectional view of the rotary indexing device of the machine tool of FIG.
FIG. 3 is a perspective view of a state in which a workpiece clamping device showing an embodiment of the present invention is attached to a pallet.
FIG. 4 is a cross-sectional view of a workpiece clamping mechanism showing an embodiment of the present invention.
FIG. 5 is a cross-sectional view of a workpiece clamping mechanism showing a second embodiment of the present invention.
FIG. 6 is a front view of a production line in which the workpiece clamping device of the present invention is used.
FIG. 7 is a perspective view of a conventional workpiece clamping device.
[Explanation of symbols]
1, 2, 3 Machine tool 11 Workpiece table 51 Mounting base 54 Collet clamper 54a Collet portion 55 Pull rod 56 Belleville spring 57 Actuator 66 Coupler 67 Accumulator 71 Positioning hole P Pallet W Workpiece

Claims (3)

Arranged on a workpiece table having an R-axis rotary table that can be rotated and positioned around the R axis orthogonal to the C axis on a C-axis rotary table that can be rotated and positioned around the C axis, and a positioning hole is formed on the seating surface In a workpiece clamping device for fixing a workpiece to a mounting base, a mounting base having a receiving surface for receiving a seating surface of the workpiece, and a projection projecting on the mounting base and fitted in a positioning hole of the workpiece A collet that is disposed in the collet so as to be capable of moving forward and backward, and a pull rod that expands the collet, and an actuator that moves the pull rod forward and backward. By moving and expanding the collet so that the outer periphery of the collet is closely fitted to the inner surface of the positioning hole. A performs its positioning and clamping against the mount simultaneously, the mount to form a polygonal pyramid shaped polyhedron, each face of the polygonal cone-shaped polyhedron, said collet, and said pull rod, said A workpiece clamping device comprising: a clamp mechanism including an actuator; and the mounting base is held on the R-axis rotary table . The workpiece clamping device workpiece clamping device according to claim 1, characterized in that is provided a removable pallet on a machine tool of the workpiece table. A coupler capable of disconnecting the actuator and a pressure oil supply source for supplying pressure oil to the actuator, and a clamping force holding means for biasing the pull rod in a direction in which the collet expands when the coupler is disconnected. The workpiece clamping device according to claim 2, wherein a workpiece clamping device is provided.

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