JP2005074474A - Work holder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a work holder capable of relieving vibrations caused by start and stop when starting retreating motions and completing forwarding motions, and making high-speed forwarding and retreating motions. <P>SOLUTION: The work holder 12 comprises a base member 20, and a work holder body 22 movably supported on the base member 20 to a linear direction between forwarding position for holding the work and retreating position for holding no work. Positions of the work holder body 22 are switched into a forwarding position and a retreating position by a position swtiching drive means 23. The position switching drive means 23 comprises a crank member 31 rotatably supported on the base member 20, and a connecting rod 33 connected between the tip of a crank arm 32 and the work holder body 22. The crank member 31 is rotated with a rotation driving means 34. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a work holder that is used in a punch press or other plate material processing machine and is movably installed between a gripping position for gripping a work and a retracted position.

2. Description of the Related Art A plate material processing machine such as a punch press is provided with a plate material feeding device that holds a plate material, which is a work placed on a work table, with a work holder and moves it to a processing position. The plate material feeding device includes a carriage that moves back and forth, a cross slide that moves the carriage left and right, and a plurality of work holders mounted on the cross slide.
By the way, when the plate material is moved to the machining position by the plate material feeding device having such a configuration, if the plate material gripping portion by the work holder becomes the machining scheduled location, if the plate material is moved to the machining position as it is, the machining planned location The work holder enters a processing position such as a punch position of the plate material processing machine, and the work holder itself is punched out.

Therefore, in order to avoid such a problem, the number of work holders arranged side by side on the movable base is set to three or more, and each work holder is moved from the advance position where the plate material is gripped to the retracted position where the plate material is not gripped. There has been proposed a work holder that can be retracted and that moves the work holder that interferes with the machining position to the retracted position. Thereby, the part used as the scrap of a board | plate material decreases, and the yield of a board | plate material can be improved.
As a configuration for moving the work holder between the advanced position and the retracted position, for example, the work holder main body is swiveled in a horizontal plane with respect to the base member of the work holder, or the work holder main body is a cylinder with respect to the base member. What is advanced and retreated (all are patent documents 1) is known.

JP 2001-212635 A

  However, in the work holder having the above-described configuration, when the work holder main body starts to move to the retracted position or advances to the advanced position and stops, vibration is caused by the sudden start and stop of the operation. Further, when the work holder stops the retracting operation and stops, or when the work holder starts the advancing operation from the retracted position, the vibration is generated in the same manner as described above. These vibrations lead to a decrease in machining accuracy, and machining efficiency decreases when waiting for the vibrations to converge. In order to alleviate the vibration, the work holder must be moved at a low speed, which causes a problem of reducing the machining efficiency. If a work motor capable of speed control such as a servomotor is used as the advance / retreat drive source, the above problem can be solved, but the motor and its control system become complicated and expensive.

An object of the present invention is to provide a work holder having a simple configuration that can relieve vibration at the start and stop of the retracting operation and advancement operation of the work holder body, and that can perform high-speed operation of advancement and retraction. .
Another object of the present invention is to secure a non-interfering space above the tip of the work holder and to allow processing near the work holder.

A work holder according to the present invention includes a base member, a work holder main body supported by the base member so as to freely advance and retract in a linear direction between an advance position for gripping the work and a retracted position for not gripping the work, and the work holder Position switching drive means for switching the position of the main body between the advanced position and the retracted position is provided. The position switching drive means includes a crank member rotatably supported by the base member, one end rotatably connected to the tip of a crank arm of the crank member, and the other end rotatably connected to the work holder body. It is assumed that the connecting rod has a rotation driving means for rotating the crank member. The rotation driving means may be constituted by a drive source that performs linear motion, such as a cylinder, and a mechanism that converts the linear motion into rotational motion, for example.
According to this configuration, the linear movement of the work holder body is given to the work holder body via the crank member and the connecting rod. At this time, even if the crank member is rotated at a constant speed, due to the operation characteristics of the crank mechanism, the speed is low at both ends of the stroke of the linear advance / retreat operation, and is high at the middle. Therefore, even when rotating at a high speed, the moving speed of the work holder body at the start of the retracting operation or at the end of the advancement, or at the end of the retracting operation or at the start of the advancement can be reduced, and vibration at the start and stop can be reduced. Since the moving speed during advancement / retraction can be increased, the advancement / retraction movement of the work holder body can be performed efficiently and in a short time. Further, since the speed is mechanically changed using a crank mechanism, a cylinder having no speed control function can be used as the rotational drive means of the position switching drive means, and the position switching drive means is simple and inexpensive. And can.

In the work holder of the present invention, for example, the connection point between the connecting rod and the work holder main body is set at a position that is removed from an imaginary straight line that passes through the rotation center of the crank member and is parallel to a straight path along which the work holder main body moves. It may be a thing.
In the crank mechanism, when the movement path of the linearly moving member is offset with respect to the straight line passing through the center of the crank member, the crank member has a section from 0 ° to 180 ° and a section from 180 ° to 360 °. The speed curve of the member that moves linearly becomes asymmetric, and the speed of one section increases. Therefore, as described above, when the linear path of the work holder main body is offset with respect to the virtual straight line passing through the rotation center of the crank member, the asymmetrical operation of the crank mechanism is effectively used, and the low speed at both ends of the stroke. However, the intermediate speed can be further increased, and the vibration at the time of retraction and advancement can be reduced while further shortening the retreat and advancement time of the work holder body.

In the case of offsetting as described above, the connecting point of the connecting rod is positioned on the table side with respect to the virtual straight line, and the work holder main body has the tip portion on the table side with respect to the virtual line at the advanced position. It may be a shape that fits. The work holder body grips an end portion of a plate material placed on a table.
In this way, when the work holder body has a shape that fits on the table side with respect to the virtual straight line at the advanced position, a space is secured above the work holder body. Therefore, the tip of the work holder main body can be submerged, for example, under a turret or other tool support, and the work holder main body is gripped by the work holder without causing a problem of interfering with the tool support. Processing in the vicinity of the grip portion of the plate material can be allowed.

A work holder according to the present invention includes a base member, a work holder main body supported by the base member so as to freely advance and retract in a linear direction between an advance position for gripping the work and a retracted position for not gripping the work, and the work holder Position switching drive means for switching the position of the main body between the advance position and the retracted position, the position switch drive means comprising a crank member rotatably supported by the base member, and a crank arm having one end at the crank member Since the connecting rod has a connecting rod that is rotatably connected to the tip of the workpiece and the other end is rotatably connected to the work holder body, and a rotation driving means that rotates the crank member. In addition, it is possible to alleviate the stop vibration, and to enable high-speed operation for advancement / retraction and a simple configuration.
When the connecting point between the connecting rod and the work holder body is set at a position that passes through the rotation center of the crank member and is removed from a virtual straight line that is parallel to the linear path along which the work holder body moves, While further shortening the advance time, it is possible to mitigate vibrations during stopping and starting for evacuation and advancement.
The work holder body grips an end portion of a plate placed on the table, the connecting point of the connecting rod is positioned on the table side with respect to the virtual straight line, and the work holder body is In the case where the tip portion has a shape that fits on the table side with respect to the virtual straight line at the advanced position, a non-interference space can be secured above the tip of the work holder, and machining in the vicinity of the work holder can be permitted.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a plate material processing machine on which a work holder of the present invention is mounted. This plate material processing machine is a turret type punch press. The frame 1 includes a work table 2 on which a plate material W that is a workpiece is placed, and a plate material feeding device 3 that moves the plate material W back and forth (Y-axis direction) and left and right (X-axis direction) on the work table 2. Is provided. The rear portion of the frame 1 is a side frame-shaped C-shaped rear frame portion 1a, and a punch drive mechanism for driving the ram 5 up and down is provided in the rear frame portion 1a. The ram 5 raises and lowers the punch tool installed on the turret 4. The work table 2 includes a central fixed table 6 fixed to the frame 1 and slide tables 8 on both sides that move back and forth on the rail 7.

  The plate material feeding device 3 includes a carriage 10 that is formed integrally with the slide tables 8 on both sides and moves back and forth, and the carriage 10 is mounted with a movable table 11 that serves as a cross slide. The carriage 10 is advanced and retracted by a feed screw (not shown) provided on the frame 1. The movable table 11 has three or more work holders 12 mounted side by side, and is driven by a servo motor 13 provided in the carriage 10 to advance and retract in the X-axis direction via a feed screw 14 and a ball nut 15. Driven.

  2 to 4 show a partially broken plan view, a side view, and a rear view of the work holder 12. The work holder 12 is supported by the base member 20 through the guide means 21 so as to be able to advance and retreat in the Y-axis direction. The work holder 12 moves forward and backwards to grip the plate material W as a work, and retracts to hold the plate material W. And a position switching drive means 23 for switching the position of the work holder main body 22 between the advanced position and the retracted position. The base member 20 is attached to the front surface of the movable table 11. A partially broken plan view of the base member 20 is shown in FIG.

  The work holder main body 22 grips the end portion of the plate material W placed on the work table 2, and as shown in a partially broken side view in FIG. An upper arm 25 having an upper jaw portion 25a at the swing end, and a second fulcrum on the distal end side of the upper arm 25 from the first fulcrum 27. And a lower arm 26 having a lower jaw portion 26a corresponding to the upper jaw portion 25a at a swing end. The upper jaw portion 25a and the lower jaw portion 26a can move toward and away from each other to grip the plate material W.

  The guide means 21 for guiding the work holder main body 22 to advance and retract between the advanced position and the retracted position includes a pair of left and right guide rails 29 provided at the lower portion of the base member 20 as shown in FIGS. Thus, the guide member 30 includes a pair of left and right guide members 30 slidably engaged with the guide rails 29 provided on both sides of the base member 20.

  As shown in FIGS. 3 and 7, the position switching drive means 23 includes a crank member 31 having a crankshaft rotatably supported by the base member 20, and a support shaft at one end of the crank arm 32 of the crank member 31. The connecting rod 33 is rotatably connected via a shaft 35 and the other end is connected to the body member 24 of the work holder main body 22 via a support shaft 36, and a rotational drive means 34 that rotates the crank member 31. The The crank member 31 and the connecting rod 33 constitute a crank mechanism 31A. The crank member 31 is supported by the base member 20 with its axis oriented in the X-axis direction, and has crank arms 32 at both ends thereof. The left and right crank arms 32 are connected to the left and right connecting rods 33, respectively. Are connected to the left and right brackets 37 of the body member 24 of the work holder body 22. The rotation drive means 34 is composed of a fluid pressure cylinder supported in a vertical orientation on the base member 20, and an advance / retreat rod 38 driven up and down meshes with a pinion 31 a formed on the crankshaft portion of the crank member 31. A rack 38a is formed. The crank member 31 rotates forward and backward by the advance / retreat operation of the advance / retreat rod 38.

  A connecting point (support shaft 36) between the connecting rod 33 and the work holder body 22 passes through a virtual straight line L that passes through the rotation center of the crank member 31 and is parallel to a straight path (Y-axis direction) along which the work holder body 22 moves. It is arranged at the removed position, that is, at the position having the offset. Specifically, the connection (support shaft 36) is positioned below the virtual straight line L where the work table 2 is located. The work holder main body 22 is configured such that, at the advanced position shown in FIG. 3, the tip end portion is accommodated below the virtual straight line L where the work table 2 is located.

  As shown in FIG. 7, the base member 20 is provided with a work holder main body positioning means 40 for restricting the position of the work holder main body 22 that has moved forward to the advanced position. The positioning means 40 has a fluid pressure cylinder supported in a vertical orientation on the base member 20, and an upward tapered surface 22 a provided on the work holder main body 22 at the lower end of an advance / retreat rod 41 driven up and down. A downward taper surface 41a is formed to engage with. When the work holder main body 22 is moved to the advanced position, the advance / retreat rod 41 is driven to advance downward, whereby the taper surface 41a of the advance / retreat rod 41 engages with the taper surface 22a of the work holder main body 22, The position of the holder body 22 is restricted to the advanced position.

  Further, as shown in FIG. 7, the base member 20 supports a swing drive means 43 that swings up and down the upper arm 25 of the work holder body 22. The swing drive means 43 is also composed of a fluid pressure cylinder supported by the base member 20 in a vertical orientation, and a hook formed at the rear end of the upper arm 25 is provided at the lower end of the advance / retreat rod 44 driven up and down. Engagement pins 45 are provided sideways so that the portion 25b can be engaged and disengaged as the work holder body 22 advances and retracts. That is, when the work holder main body 22 advances to the advance position where the plate member W is gripped, the hook portion 25b of the upper arm 25 is engaged with the engagement pin 45, and the upper arm 25 is moved to the first position by the ascent (retreat) of the advance / retreat rod 44. The upper jaw 25a closes downward by swinging about the fulcrum 27. When the work arm body 22 moves from the advanced position to the retracted position after the upper arm 25 swings so that the upper jaw part 25a opens upward as the advance / retreat rod 44 descends, the hook part 25b of the upper arm moves forward / backward. The engagement is released from the engagement pin 45 at the lower end of 44. The rear of the upper arm 25 from the first fulcrum is urged so that the upper jaw portion 25a opens upward by a spring member (not shown), and the state is maintained. The body member 24 of the work holder body 22 is provided with a stopper 46 that limits the opening of the upper jaw portion 25a of the upper arm 25 to a predetermined angle.

  The lower arm 26 is connected to the upper arm 25 via the interlocking member 47 and pushes up the swinging portion behind the lower arm 26 using the lowering operation of the upper arm 25. Specifically, one end of the interlocking member 47 is swingably connected to the upper arm 25 via the pin 48, and the other end of the interlocking member 47 is connected to the second fulcrum 28 of the lower arm 26 via the pin member 49. On the other hand, it is connected to a swinging transmission part 26b located on the opposite side to the lower jaw part 26a. A cam groove 50 is provided in the swinging transmission portion 26 b of the lower arm 26, and the pin member 49 is fitted into the cam groove 50. Further, the movement of the pin member 49 is restricted by a horizontal guide groove 51 (FIG. 5) provided in the body member 24.

  The cam groove 50 of the lower arm 26 has a slope portion 50a having an upward slope in a direction from the first fulcrum 27 of the upper arm 25 toward the upper jaw portion 25a, and a horizontal portion 50b following the slope portion 50a. When the member 49 is positioned on the gradient portion 50a, the upper surface of the lower jaw portion 26a is positioned below the lower surface of the plate material W. When the member 49 is positioned on the horizontal portion 50b, the plate material W is kept in a horizontal position. ing. Further, the horizontal portion 50 b of the cam groove 50 has a horizontal length that allows the upper jaw 25 a of the upper arm 25 to move until the upper jaw 25 a contacts the plate material W.

  Next, the operation of the work holder 12 configured as described above will be described. FIG. 9 shows a state in which the work holder body 22 is retracted to the retracted position. From this state, the operation of the work holder main body 22 to advance to the advance position for gripping the plate material W is performed by the rotation drive means 34 of the position switching drive means 23 moving the advance / retreat rod 38 downward (advance). That is, as the advance / retreat rod 38 is lowered, the crank member 31 having the pinion 31a meshing with the rack 38a (FIG. 8) of the advance / retreat rod 38 rotates clockwise in FIG. 9, and the left and right crank arms 32 and the connecting rod 33 are rotated. Changes from the state of FIG. 10 to the state of FIG. By such an action of the position switching drive means 23, the work holder body 22 advances from the retracted position in FIG. 9 to the advanced position in FIG.

  At the start of advancement from the retracted position, the crank arm 32 rotates clockwise from an angle slightly exceeding 90 ° with respect to the horizontal, as shown in FIGS. 9 and 10, and is thus connected to the connecting rod 33 of the crank arm 32. The tip part to be done has a change up and down as much as a change back and forth. For this reason, the advance speed of the work holder main body 22 becomes slower than the rotational speed of the crank member 31, and vibration generated at the start of advance from the retracted position can be suppressed to be small. From the time when the crank arm 32 slightly exceeds 90 ° to the advancing position, the tip end portion of the crank arm 32 is greatly changed in the advancing direction. The advancement speed of the holder body 22 is increased. When approaching the advance position, the tip end portion of the crank arm 32 is almost changed downward, so that the advance speed of the work holder main body 22 becomes slower than the rotational speed of the crank member 31. For this reason, the vibration which arises at the time of completion | finish of advance can be suppressed small.

As described above, when the advancement is started from the retreat position and when the advancement is completed, the advancement speed is slowed down, so that vibration can be suppressed small, and the advancement operation can be efficiently performed because the advancement is performed at a high speed. FIG. 12 shows the relationship between the rotation angle of the crank member 31 and the moving speed of the work holder body 22 at this time.
When retreating from the advanced position to the retracted position, the operation reverse to the advanced operation is followed. That is, when the retraction is started from the advance position, the movement speed of the work holder main body 22 is low, the movement speed is high in the middle, and the movement speed is low again near the end of the retraction position. As a result, vibration generated at the start and end of the retreat can be suppressed to a low level, and the retreat operation can be performed efficiently.

  In particular, in this embodiment, the connection point (support shaft 36) between the connecting rod 33 and the work holder body 22 passes through the rotation center of the crank member 31 and the linear path (Y axis direction) along which the work holder body 22 moves. Since the position is set off from the parallel virtual straight line L (FIG. 3), vibration generated at the end of the retreat operation or at the start of advance can be effectively reduced. That is, in general, in the crank mechanism, when the movement path of the linearly moving member is offset with respect to the straight line passing through the center of the crank member, the section of the crank member from 0 ° to 180 ° and from 180 ° to 360 ° The speed curve of the member that moves linearly in the section becomes asymmetric, and the speed in one section increases. Therefore, as described above, when the linear path of the work holder main body 22 is offset with respect to the virtual straight line L passing through the rotation center of the crank member, the asymmetrical operation of the crank mechanism is effectively used, and both stroke ends. The intermediate speed can be further increased while the speed is low, and the vibration at the time of stopping and starting for retreat and advance can be reduced while further shortening the retreat and advance time of the work holder main body 22.

  When the work holder main body 22 has reached the advanced position, the advancement / retraction rod 41 advances (lowers) as shown in FIG. 7 by driving the work holder main body positioning means 40, and the tapered surface 41a at the lower end of the advance / retreat rod 41 Engage with the tapered surface 22 a of the work holder body 22. As a result, the work holder main body 22 is positioned by both the position switching drive means 23 and the work holder main body positioning means 40 at the advanced position, and the work holder main body 22 at the advanced position for gripping the plate material W (workpiece). Therefore, the gripping operation can be ensured.

  In the state where the work holder main body 22 has reached the advanced position, the hook portion 25b at the rear end of the upper arm 25 engages with the engagement pin 45 of the advance / retreat rod 44 of the swing drive means 43 as shown in FIG. . Thus, in the state where the advance / retreat rod 44 is retracted upward, the upper jaw portion 25a of the upper arm 25 swings downward as shown in FIG. Regardless of the swing of the upper arm 25, the pin member 49 is restricted from changing up and down by the guide groove 51 (FIG. 5) of the body member 24. As a result, the pin member 49 is positioned in the horizontal portion 50 b of the cam groove 50 in the swinging transmission portion 26 b of the lower arm 26. Therefore, the lower arm 26 swings counterclockwise around the second fulcrum 28, and the lower jaw portion 26 a is in a closed state where the lower arm portion 26 a meshes with the upper jaw portion 25 a of the upper arm 25.

  When the advance / retreat rod 44 of the swing drive means 43 advances downward from the closed state, the upper jaw portion 25a of the upper arm 25 swings upward as shown in FIG. Regardless of the swing of the upper arm 25, the pin member 49 is restricted from changing up and down by the guide groove 51 (FIG. 5) of the body member 24. As a result, the pin member 49 is displaced to the gradient portion 50 a of the cam groove 50 in the swinging transmission portion 26 b of the lower arm 26. For this reason, the lower arm 26 swings clockwise around the second fulcrum 28, and the lower jaw portion 26 a is in an open state in which it is separated from the upper jaw portion 25 a of the upper arm 25. At this time, the lower jaw portion 26a is positioned below the plate material W. In this open state, the carriage 10 (FIG. 1) is advanced to bring the work holder 12 closer to the end of the plate material W, so that the upper jaw portion 25a and lower jaw portion 26a of the work holder body 22 can grip the end portion of the plate material W. It becomes a state. From this state, as shown in FIG. 11A, the end portion of the plate member W is gripped by the work holder body 22 by closing the upper jaw portion 25a and the lower jaw portion 26a.

  In the closing operation of the upper and lower jaw portions 25a, 26a, the pin member 49 moves from the slope portion 50a of the cam groove 50 to the horizontal portion 50b, so that the plate material W is kept in a horizontal posture after the lower jaw portion 26a is closed. It will stop at the position. Further, since the horizontal portion 50b of the cam groove 50 has a horizontal length that allows the upper jaw portion 25a to move until the upper jaw portion 25a contacts the plate member W, the lower jaw portion 26a stops at the above position. The upper jaw portion 25a swings further downward to grip the plate material W. As a result, the plate material W can be reliably gripped by the upper and lower jaw portions 25a and 26a, and plate material processing performed in parallel with the plate material feed thereafter can be maintained with high accuracy.

  The connecting point (support shaft 36) of the connecting rod 33 to the work holder main body 22 in the position switching drive means 23 for switching the position of the work holder main body 22 between the advanced position and the retracted position is the virtual straight line L (FIG. 3). ) Is positioned below the work table 2 (FIG. 1), and the work holder main body 22 has a shape in which the tip end part is located below the work table 2 below the virtual straight line L at the advanced position. A space is secured above the work holder 12. Therefore, the tip of the work holder main body 22 can be submerged, for example, under the turret 4 (FIG. 1) or other tool support, and the work holder main body 22 interferes with the tool support. In addition, processing in the vicinity of the grip portion of the plate material W gripped by the work holder 12 can be allowed.

BRIEF DESCRIPTION OF THE DRAWINGS It is an external appearance perspective view of the board | plate material processing machine carrying the work holder concerning 1st Embodiment of this invention. It is a partially broken plan view of the work holder. It is a side view of the work holder. It is a rear view of the work holder. It is a perspective view of the work holder main body in the work holder. It is a partial fracture top view of the base member in the work holder. It is a partially broken side view of the work holder. It is principal part sectional drawing of the position switching drive means in the work holder. It is a side view which shows the state which has the work holder main body of the work holder in a retracted position. It is a side view which shows the state which the work holder main body of the work holder advanced a little from the retreat position. It is opening / closing operation | movement explanatory drawing of the work holder main body of the work holder. It is a graph which shows the relationship between the rotational position of the crank member in the work holder, and the moving speed of a work holder main body.

Explanation of symbols

2 ... Work table 20 ... Base member 22 ... Work holder body 23 ... Position switching drive means 31 ... Crank member 32 ... Crank arm 33 ... Connecting rod 34 ... Rotation drive means W ... Plate material (workpiece)
L ... Virtual straight line

Claims (3)

A base member, a work holder main body supported by the base member so as to freely advance and retreat in a linear direction between a position where the workpiece is advanced and a position where the workpiece is not held, and the work holder main body is retracted from the advanced position. A position switching drive means for switching the position to the position, the position switching drive means being rotatably connected to the crank member rotatably supported by the base member and one end rotatably connected to the tip of the crank arm of the crank member. A work holder having a connecting rod whose other end is rotatably connected to the work holder body, and a rotation driving means for rotating the crank member. The work holder according to claim 1, wherein a connecting point between the connecting rod and the work holder main body is set at a position that is removed from an imaginary straight line that passes through the rotation center of the crank member and is parallel to a straight path along which the work holder main body moves. The work holder main body grips an end portion of a plate placed on a table, a connecting point of the connecting rod is positioned on the table side with respect to the virtual straight line, and the work holder main body is The work holder according to claim 2, wherein the tip end portion is located on the table side with respect to the virtual straight line at the advanced position.

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