WO2022190176A1

WO2022190176A1 - Workpiece clamping device

Info

Publication number: WO2022190176A1
Application number: PCT/JP2021/009045
Authority: WO
Inventors: 柳崎淳
Original assignee: 株式会社Fuji
Priority date: 2021-03-08
Filing date: 2021-03-08
Publication date: 2022-09-15
Also published as: JPWO2022190176A1

Abstract

A workpiece clamping device that enables a workpiece to be sent to the next step in an inverted state, the workpiece clamping device having a lower unit in which a lower-side clamping block that supports a workpiece from beneath is rotated by a drive motor, an upper unit in which an upper-side clamping block that presses the workpiece from the upper side thereof is freely rotatable by a rotating shaft that is coaxial with the lower-side clamping block, a lift mechanism that raises and lowers the upper unit along the rotating shaft, an actuator that moves the upper unit in the rotating shaft direction in a raising/lowering part of the lift mechanism, an upper/lower unit connecting mechanism that downwardly retracts a retracting rod on the rotating shaft that protrudes downward from the upper unit by grasping the retracting rod inside the lower unit, and a tapered arbor that is disposed in a state in which the retraction rod penetrates therethrough and that is fitted by the urging force of an urging member into a center hole of the workpiece attached to a taper.

Description

Work clamp device

The present invention relates to a work clamping device compatible with a work having a tapered hole formed in the center.

In the hobbing machine, gear cutting is performed on the outer periphery of the work with a hole formed in the center, so the center of the work is held by the work clamping device. In this way, the work clamping device of the work machine, which performs processing, deburring, polishing, etc. on the outer peripheral side of the work, is configured to hold the work in the central portion in which the hole is formed. Patent Literature 1 listed below discloses an example of such a work clamping device. In the work clamping device of the document, a first support is provided on a base on a hobbing machine table, and a second support is provided on an upper center support via a rotary joint so as to face the first support. is installed. The first support is provided with three supporting claws for supporting the lower end surface of the work with the center hole formed thereon, and three centering claws for centering the work. The support claws are arranged at positions corresponding to the size of the work, and the centering claws are brought into contact with the inner diameter surface of the work for centering.

JP-A-2000-343329

　Conventional work clamping devices had various problems. For example, when the center hole of the workpiece is tapered, the conventional apparatus with a chuck mechanism that clamps the workpiece with centering claws cannot handle the workpiece, and a new workpiece clamping apparatus with a special chuck mechanism has to be manufactured. Further, the conventional work clamping device is configured to center and support the work from below. Therefore, when it is necessary to reverse the work on the next processing machine, etc., the autoloader that transports the work is once sent to the reversing device, where the reversed work is re-grabbed and transferred to the next processing machine. I had to send. Alternatively, an auxiliary loader for reversing the work is incorporated in a processing machine such as a hobbing machine, where the work is reversed and conveyed to the next process by an autoloader. However, in either case, new equipment is required, which is costly and hinders the downsizing of the processing machine.

Therefore, in order to solve this problem, an object of the present invention is to provide a work clamping device that makes it possible to send the work to the next process in an inverted state.

A work clamping device according to one aspect of the present invention includes a lower unit in which a lower clamp block that supports a work from below is rotated by a drive motor, and an upper clamp block that holds the work from above is coaxial with the lower clamp block. an upper unit rotatable by a rotating shaft; a lift mechanism for lifting and lowering the upper unit along the rotating shaft; an actuator for moving the upper unit in the direction of the rotating shaft in an elevating section of the lift mechanism; an upper and lower unit connecting mechanism for pulling downward by gripping a pull-in rod on the rotating shaft that protrudes outward inside the lower unit; a tapered arbor that is fitted under the biasing force of the biasing member.

According to the above configuration, the upper unit is lowered to the clamping position by the lift mechanism, and the work is sandwiched between the lower clamp block and the upper clamp block by operating the actuator. At this time, centering is performed by fitting the tapered arbor biased by the biasing member into the center hole of the tapered workpiece, and the pull rod protrudes downward from the upper unit by the upper unit connecting mechanism. is pulled downward inside the lower unit to securely clamp the work. After that, when the workpiece rotated by the drive motor of the lower unit is subjected to a predetermined treatment and the upper unit is lifted to release the workpiece after treatment, the tapered arbor is caught in the stop hole. The workpiece is lifted and can be removed in an inverted state.

It is a front view showing a processing machine line. FIG. 3 is a perspective view showing a hobbing machine module; FIG. 3 is a perspective view showing a hobbing machine module with an exterior cover removed; FIG. 4 is a cross-sectional view showing the work clamping device during work delivery; FIG. 4 is a cross-sectional view of the work clamping device showing one stage of the work clamping process; FIG. 4 is a cross-sectional view of the work clamping device showing one stage of the work clamping process; FIG. 4 is a cross-sectional view of the work clamping device showing one stage of the work clamping process; FIG. 4 is a cross-sectional view showing the work clamping device when the work is released;

An embodiment of a work clamping device according to the present invention will be described below with reference to the drawings. In this embodiment, a hobbing machine constituting a processing machine line will be described as an example. FIG. 1 is a front view showing the processing machine line. In the processing machine line 100, a lathe, a machining center, an inspection machine, or the like is installed side by side between a work loading module 1 on the right end of the drawing, which is a work loading section, and a work discharge module 11 on the left end of the drawing, which is a work unloading section. ing. Various automatic work machines such as lathes, machining centers, inspection machines, and hobbing machines are modularized.

Lathe modules

2 and 3 and an inspection module 4 are installed in order next to the work loading module 1, and the dimensions of the work that has undergone the first and second machining are checked. In addition, a work table module 5 for receiving and checking the quality of the work continues, and a machining center module 6 for performing third processing such as boring and drilling is installed. A second work table module 7 for temporarily placing and removing a work and a hobbing machine module 8 for gear cutting as the fourth processing are installed. A removing module 9 and a washing module 10 for washing off chips and the like adhering to the work are installed in this order.

In the processing machine line 100, predetermined processing and processing are performed while the work moves between various modules 1 to 11 in order. The processing machine line 100 is provided with a workpiece transport robot 15 for transporting workpieces to the respective modules 1-11. The workpiece transfer robot 15 is a multi-joint robot arm that moves on rails provided in front of the modules 1-11. The modules 1 to 11 are covered with an exterior cover 16 having a unified appearance, and as shown in FIG. 2, a transfer space 18 in which a workpiece transfer robot 15 moves is formed by an openable front cover 17. As shown in FIG.

FIG. 2 is a perspective view showing the hobbing machine module 8, and FIG. 3 is a perspective view showing the hobbing machine module 8 with the exterior cover 16 and the front cover 17 removed. The hobbing machine module 8 is assembled on a movable bed 21 equipped with wheels like other modules, and is movable in the front-rear direction along rails 121 fixed to the upper surface of the base 12. . The width dimensions of the various modules 1 to 11 are unified, two modules can be mounted on one base 12, and the hobbing machine module 8 has a double width dimension. In this embodiment, the longitudinal direction of the machine body is the X-axis, the width direction of the machine body is the Y-axis, and the vertical direction is the Z-axis.

In the hobbing machine module 8, a column 23 on a movable bed 21 is movable in the X-axis direction in the longitudinal direction of the machine body, and a saddle 24 is attached to the front surface of the column 13 so as to be slidable in the Z-axis direction. It is configured to be raised and lowered by a Z-axis servomotor 25 . A hob head 26 that supports a hob 27 is attached to the saddle 24 . The hob 27 is rotatably supported by a rotating shaft in the Y-axis direction, and is rotated during gear cutting by a hob motor. The hob head 26 is structured to be movable in the Y-axis direction with respect to the saddle 24 by a Y-axis servomotor 28 so that the position of the blade of the hob 27 can be changed. A control panel 29 for controlling each driving part of the hobbing machine module 8 is mounted on the movable bed 21 .

A work clamping device 30 is provided on the front side of the hob 23 . FIG. 4 is a sectional view showing the workpiece clamping device 30, showing a part of the workpiece transfer robot 15 in a workpiece transfer state. The workpiece clamping device 30 is configured vertically such that a lower unit 31 and an upper unit 32 are coaxial with the center of rotation aligned with the Z axis. A support column 33 is erected on the movable bed 21 to constitute a lift mechanism for moving the upper unit 32 up and down in the Z-axis direction. That is, a vertical rail is fixed to the support column 33, and a lift 34 holding the upper unit 32 is slidably assembled thereon. A Z-axis servomotor 35 is provided at the top of the support column 33, and its rotational output is converted into linear motion of the lift 34 by a ball screw.

In the lower unit 31, a table 41 is fixed to a movable bed 21, and a hollow spindle 42 is rotatably supported therein with its center of rotation aligned with the Z axis. 44. A lower clamp block 47 is attached to the spindle 42 via connecting

blocks

45 and 46 so as to rotate together. The

connecting blocks

45, 46 and the lower clamping block 47 are formed with a hollow hole coaxial with the spindle 42, in which the pull-in shaft 51 is assembled while being constantly biased downward by a spring 52. As shown in FIG. The spring 52 is formed by stacking a plurality of disc springs in the axial direction.

A piston rod 531 is inserted into the spindle 42 from below. A hydraulic cylinder portion 54 is formed in the lower portion of the lower unit 31, and a piston 53 integrated with a piston rod 531 is incorporated. A port 541 is formed in the lower pressurizing chamber of the piston 53 in the cylinder portion 54, and the piston 53 is displaced upward as shown in the drawing by hydraulic oil supplied from the port 541. As shown in FIG. That is, the piston 53 is configured to push up the pull-in shaft 51 against the biasing force of the spring 52 .

Next, a cylindrical support portion 341 is formed in the lift 34 , and the upper unit 32 is slidably inserted into the support portion 341 via a cylindrical lifting pipe 61 . A hydraulic cylinder 37 is fixed to the lift 34 via a bracket 36 , and a lifting pipe 61 is connected to the hydraulic cylinder 37 via a connecting block 62 . Therefore, the upper unit 32 is configured to move up and down with respect to the lift 34 by extending and retracting the piston rod 371 in the hydraulic cylinder 37 .

A shaft 65 having a flange portion 651 is inserted from below into the lifting pipe 61 and the skirt block 64 fixed to its lower end. The shaft 65 is rotatably held by a bearing with the lifting pipe 61, and in addition to the radial bearing, a thrust bearing is provided to receive an axial load. The hydraulic cylinder 37 and the shaft 65 are configured so that their centers are coaxially overlapped along the Z-axis.

The upper clamp block 66 and the pull-in rod 67 are integrally fixed to the flange portion 651 of the shaft 65 . The cylindrical upper clamp block 66 is closed at the top by a flange portion 671 of the pull-in rod 67, and incorporates therein a tapered arbor 71 that is penetrated by the pull-in rod 67 protruding downward. The pull-in rod 67 has a head portion 672 formed by a circular recess formed in the tip portion thereof. A member 55 is adapted to be hooked.

The workpiece W to be processed has a tapered center hole H with an inclined inner peripheral surface so that the diameter of the lower side becomes smaller at the center. Therefore, the tapered arbor 71 has a tapered surface matching the angle of the central hole H. As shown in FIG. The tapered arbor 71 is attached so as not to fall downward by hooking on the flange portion, and is urged downward by a spring 72 located above. The upper clamp block 66, the pull-in rod 67, and the tapered arbor 71 are assembled by screwing or the like so as to be disassembled, and are integrally fixed to the shaft 65 by screwing. That is, the tapered arbor 71 can be recombined according to the hole shape of the work W.

Next, the operation of the work clamping device 30 will be described along with the processing of the work W of the hobbing machine in the processing machine line 100. In the processing machine line 100, the first processing and second processing of the

lathe modules

2 and 3 and the dimension confirmation of the inspection module 4 are performed as described above. A third machining is performed in the machining center module 6 after a quality check is performed in the work table module 5 . In such a process, the workpieces are conveyed in order by the workpiece transfer robot 15 on the right side of FIG. In the post-process, the workpiece is taken out from the workpiece table module 7, gear-cut by the hobbing machine module 8, deburred by the deburring module 9, and chips and the like washed off by the cleaning module 10.

A workpiece W is carried into the hobbing machine module 8 by a workpiece transfer robot 15 as shown in FIG. A robot hand (not shown in the drawing) equipped with a pair of chucks is provided at the tip of the work transfer robot 15. One of the chucks removes the processed work Wa, and the other reversed chuck holds a new work W. , is placed on the empty lower clamp block 47 . 5 to 7 are diagrams showing step by step the work clamping process of the work clamping device 30 that holds such a work W so that it can be processed.

First, as shown in FIG. 5, the upper unit 32 held by the lift 34 is lowered by driving the Z-axis servomotor 35 . At this time, the upper clamp block 66 is placed above the work W at a certain distance, and the downwardly protruding drawing rod 67 penetrates the work W and is inserted into the drawing hole 511 formed in the drawing shaft 51 . be done. Then, as shown in FIG. 6, the hydraulic cylinder 37 is extended while the height of the upper unit 32 is kept constant. As a result, the lifting pipe 61 and the shaft 65 rotatably held therein are lowered.

As the shaft 65 descends, the upper clamp block 66 is brought into contact with the work W, and the work W is sandwiched between the upper clamp block 66 and the lower clamp block 47 from above and below. At this time, the taper arbor 71 is pushed into the center hole H of the work W by the spring 72 and centered. Then, as shown in FIG. 7, the pull-in rod 67 is further inserted deeply into the pull-in hole 511 of the pull-in shaft 51 . That is, in the lower unit 31 up to this point, the hydraulic oil supplied from the port 541 into the cylinder portion 54 pressurizes the piston 53 from below to push up the pull-in shaft 51 .

Therefore, the hydraulic oil in the cylinder portion 54 is discharged from the port 541 and the piston 53 is released from the hydraulic pressure, so that the pull-in shaft 51 is pushed down by the biasing force of the spring 52 . As a result, the head portion 672 is gripped by the piece member 55 provided near the opening of the pull-in hole 511 and the pull-in rod 67 is pulled downward, thereby firmly connecting the upper unit 32 to the lower unit 31 . Then, the workpiece W sandwiched between the lower clamp block 47 and the upper clamp block 66 can be securely clamped.

In the workpiece clamping device 30 ready for machining the workpiece W, the rotation is transmitted to the spindle 42 via the worm gear 44 by driving the spindle motor 43, and the lower unit 31 and the lower clamp block 47 are integrally rotated. do. Since the piston rod 531 is separated from the pull-in shaft 51 when the piston 53 is lowered, the pull-in shaft 51 and the spring 52 also rotate integrally with the spindle 42 . In the upper unit 32 , the pull-in rod 67 and the upper clamp block 66 held by the pull-in shaft 51 rotate while being supported by the shaft 65 . Therefore, in the hobbing machine module 8, the hob 27 synchronized in rotation with respect to the rotating work W moves in the Z-axis direction, so that the outer periphery of the work W is gear-cut.

After gear cutting, the work clamping device 30 releases the machined work Wa as shown in FIG. FIG. 8 is a cross-sectional view of the work clamping device 30 in the state of releasing the machined work, and in particular only the upper unit 32 is shown. When the workpiece is released, hydraulic oil is first supplied from the port 541 into the cylinder portion 54, and the piston 53 is returned to the state shown in FIG. As a result, the pull-in shaft 51 is pushed up and the pull-in rod 67 is released from the piece member 55 . After that, the Z-axis servomotor 35 drives the lift 34 so that the upper unit 32 is separated from the lower unit 31, and the workpiece Wa is released from the clamped state.

In the workpiece clamping device 30, the tapered arbor 71 is strongly fitted into the center hole H of the workpiece W by the spring 72 when clamping before machining. is lifted. Conventionally, as indicated by the dashed line, when the upper unit 32 is lifted, the processed work Wa is left on the lower clamp block 47 (lower unit 31). However, in this embodiment, since the processed work Wa is lifted, when the work transfer robot 15 removes the processed work Wa, the processed work Wa is grasped from the lower side (opposite side), contrary to the conventional art.

Therefore, according to this embodiment, even if the work W has a tapered center hole H, it is possible to center the work W at the time of clamping by inserting the tapered arbor 71 having a tapered angle into the center hole H. become. Moreover, since there is no driving part such as a chuck claw as compared with the conventional chuck mechanism, the structure is simple and the cost can be reduced. Furthermore, since the machined work Wa after machining is lifted by the tapered arbor 71 fitted in the center hole H, the machined work Wa can be lifted by simply removing it with the work transfer robot 15 without using a conventional reversing device. can be conveyed to the next step in the inverted state. Also, even if the dimensions of the work W are different, it can be easily handled by recombining the upper clamp block 66 and the tapered arbor 71 to match the dimensions. Further, when the machined work Wa does not need to be turned over, it can be easily handled by rearranging the configuration without the taper arbor 71 .

Although one embodiment of the present invention has been described, the present invention is not limited to this, and various modifications can be made without departing from the scope of the invention.
For example, in the first embodiment, a work clamping device constituting a hobbing machine was described, but the work clamping device may be constructed as a work clamping device such as a grinding machine.

8 Hobbing machine module 15 Work transfer robot 27 Hob 29 Control panel 30 Work clamp device 31 Lower unit 32 Upper unit 33 Support column 34 Lift 35 Z-axis servo motor 37 Hydraulic cylinder 41 Table 42 Spindle 43 Spindle motor 47 Lower clamp block 51 Draw shaft 55 Top member 53 Piston 54 Cylinder 65 Shaft 66 Upper clamp block 67 Draw rod 71 Taper arbor 72 Spring H... Center hole W...Work

Claims

a lower unit in which a lower clamp block that supports the workpiece from below is rotated by a drive motor;
an upper unit in which an upper clamp block that holds a workpiece from above is rotatable by a rotary shaft coaxial with the lower clamp block;
a lift mechanism that raises and lowers the upper unit along a rotation axis;
an actuator for moving the upper unit in the direction of the rotation axis in the lifting section of the lift mechanism;
an upper and lower unit connecting mechanism for pulling downward by gripping a pull-in rod on a rotating shaft protruding downward from the upper unit inside the lower unit;
a tapered arbor, through which the drawing rod passes, and which is fitted into the tapered center hole of the workpiece by the biasing force of the biasing member;
A work clamping device having
The work clamping device according to claim 1, wherein the upper unit comprises the upper clamp block, the drawing rod, the tapered arbor, and the biasing member assembled so as to be disassembled and mounted on the rotating shaft.
The upper clamp block has a central portion formed with a through hole in the rotation axis direction, the drawing rod is fixed to the upper clamp block so that the flange portion closes the central portion from above, and the A rod part protrudes downward from the central part, and the tapered arbor is inserted into the central part of the upper clamp block in a state in which movement in the downward direction is restricted, and is urged downward by the urging member. 3. The workpiece clamping device according to claim 2, which is a