JP4430442B2 - Work clamp device - Google Patents

Description

  The present invention relates to a workpiece clamping device for clamping a workpiece.

Conventionally, for example, as a method of clamping a workpiece when performing deburring of a workpiece surface, a plurality of guide pins are set up on a base on which the workpiece is placed, and these guide pins are inserted into corresponding holes provided in the workpiece. In some cases, the workpiece was positioned and held. However, this method has a problem in that it takes time to change the setup because the guide pin mounting position must be changed each time the workpiece diameter changes or the workpiece hole position shifts.
As another method, a pressing plate is movably disposed along the reference plane of the base, and a workpiece placed on the reference plane is placed between the pressing plate and a wall facing the moving direction. Some have been sandwiched and positioned (see, for example, Patent Document 1).
JP 2003-48130 A

However, since the workpiece is not centered by the above method, the machining position must be adjusted every time the workpiece diameter changes, and the problem of time-consuming setup change has not been solved.
On the other hand, there is also a hand that uses a self-aligning chuck to center the workpiece, but such a chuck device generally has a complicated structure and the necessity of ensuring a large movement stroke of the chuck, etc. Due to this, there is a disagreement that the size of the entire apparatus is increased, and therefore another method has been desired.

  The present invention has been completed based on the above-described circumstances, and it is an object of the present invention to provide a work clamping device that enables centering of a work and does not require setup change.

As means for achieving the above object, the invention of claim 1 is a work clamping device for clamping the work when the surface of the work is machined, and a support base for placing the work, and this support And at least three clampers that are arranged at equal intervals in the circumferential direction around the table and clamp the workpiece based on the rotating cam operation thereof, and the clamper abuts on the outer peripheral edge of the workpiece and rotates. In addition, a pressing surface that can press the workpiece in the centripetal direction is provided , and a magnetic force adsorption means is disposed on the back side of the support base, and the magnetic force adsorption means can move in a direction toward or away from the support base. When the workpiece is in the approach position, the workpiece can be sucked and held. When the workpiece is in the separated position, the workpiece can be sucked and held, and the workpiece can be released on the rotation axis of the clamper. The cam follower that can be engaged with the cam is provided on one of the portion that performs the above and the magnetic force adsorption means, and the cam follower is provided with the rotation of the clamper in the clamping direction. By moving along the cam surface of the cam, the magnetic force attracting means can be moved toward the approach position side, and the return direction along the cam surface of the cam as the clamper rotates in the unclamping direction. It is characterized in that the magnetic force adsorbing means can be moved toward the separated position side by moving the magnetically attracting means .

  A second aspect of the invention is characterized in that, in the first aspect of the invention, the clamper is constituted by an eccentric cam having a substantially circular shape.

According to a third aspect of the present invention, in the first or second aspect , the magnetic force adsorbing means is constantly urged toward the support base by an urging member, and the urging member includes the clamper. It is characterized in that it is compressed while accumulating urging force by rotation in the unclamping direction.

<Invention of Claim 1>
When the workpiece is placed on the support base and the clamper is rotated, the clamp surface of the clamper comes into contact with the outer peripheral edge of the workpiece and presses the workpiece in the centripetal direction along with the rotation of the clamper. . Further, even if the workpiece has a different diameter, the workpiece can be guided to the machining center based on the rotation cam operation of the clamper, so that it is not necessary to change the setup each time the workpiece diameter changes.
Further, since the work can be attracted and held by bringing the magnetic force attracting means closer to the approach position side, the work can be stably and reliably combined with the clamp by the clamper. On the other hand, when the processing of the workpiece is completed, the workpiece can be removed from the support base without difficulty by moving the magnetic force attracting means to the separated position side.
In this case, when the clamper is rotated in the clamping direction, the cam follower moves along the cam surface of the cam to bring the magnetic force attracting means to the approach position, and the workpiece is attracted and held at this approach position. On the other hand, when the clamper is rotated in the unclamping direction, the cam follower moves in the return direction along the cam surface of the cam to bring the magnetic force attracting means to the separated position, and at this separated position, the workpiece adsorption is released. Therefore, since the driving for performing the clamping and unclamping by the clamper and the suction holding and the suction holding release by the magnetic suction means can be provided by one rotating shaft, the entire apparatus can be simplified and miniaturized.

<Invention of Claim 2>
Since the clamper is formed of an eccentric cam having a substantially circular shape, the phase can be easily adjusted as compared with a deformed type having a pressing surface whose radius from the shaft center is not constant. In addition, a smooth clamping operation is ensured and the centering accuracy of the workpiece can be increased.

<Invention of Claim 3 >
The magnetic force attracting means is constantly urged toward the support base by the urging member, and this urging member is elastically compressed while accumulating the urging force when the clamper is rotated in the unclamping direction. The magnetic force adsorption means can be held in the apparatus without rattling.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. The workpiece clamping device according to the present embodiment is an example when applied to a brush device that removes flash or the like generated on the workpiece surface. Reference numeral 10 in the figure denotes a housing that constitutes the outer frame of the device. Indicates a frame in which the apparatus is installed.

As shown in FIG. 1, the housing 10 includes a hollow columnar housing main body 11 having a support 12 for placing a work 30, and a drive shaft 13 below the housing main body 11. The inner cylinder part 14 inserted coaxially, the outer cylinder part 15 in which this inner cylinder part 14 was inserted coaxially, and the bearing 17 inserted between this outer cylinder part 15 and the inner cylinder part 14 The inner cylinder part 14 and the housing main body part 11 are integrally connected by a bolt 16, and the inner cylinder part 14 is allowed to rotate by a bearing 17. An air supply path 18 is provided in the lower wall 24 of the housing main body 11 so as to communicate with the air introduction port 19 of the outer cylinder part 15, and the workpiece 30 is processed through the air supply path 18 from the air introduction port 19. Air purge is performed to keep the inside of the housing main body 11 in a high pressure state, thereby preventing the machining liquid from entering the inside.
On the other hand, a motor 51 is fixed to the frame 50, and the operation of the motor 51 rotates the inner cylinder portion 14 connected via the gear 52 and the housing main body portion 11. Further, the frame 50 is provided with a mounting portion 53, and the outer cylinder portion 15 is vertically inserted into the mounting portion 53 and attached by a bolt 54.

  The drive shaft 13 is disposed substantially vertically in the inner cylinder portion 14, and a bush 20 is interposed between the drive shaft 13 and the inner cylinder portion 14. A drive gear 21 is provided at the upper end of the drive shaft 13, and the lower end portion of the drive shaft 13 is coupled to a motor shaft 61 of an actuator 60 for rotating the drive gear 21 via a coupling 62. Around the coupling 62, a surrounding portion 23 that is integrally connected to the lower end of the inner cylinder portion 14 is coaxially arranged. On the outer peripheral surface of the surrounding portion 23, a detected portion that can face the detection portion 70 of the sensor. 23A protrudes.

  The upper end portion of the drive shaft 13 passes through the lower wall 24 of the housing main body portion 11 and faces the inside of the housing main body portion 11. As shown, the four driven gears 22 mesh with each other with an angular difference of 90 ° in the circumferential direction. In the case of this embodiment, the gear ratio between the drive gear 21 and the driven gear 22 is set to 2 to 1, and when the drive gear 21 rotates 90 °, the driven gear 22 rotates 180 °.

  A rotating shaft 25 is erected substantially vertically from the center of the driven gear 22 and the upper end of the rotating shaft 25 passes through the upper wall 28 of the housing body 11 and faces the outside. A clamper 26 for clamping the work 30 is attached to the upper end of the rotary shaft 25. The clamper 26 is formed of a light metal material such as aluminum in a substantially circular shape, and is configured as an eccentric cam in which the axis of the rotary shaft 25 is located at a position eccentric from the center. The clampers 26 are each configured with the same phase, and are provided with a pressing surface 27 that contacts the outer peripheral edge of the work 30 as it rotates and presses the work 30 in the centripetal direction.

  The upper surface of the upper wall 28 of the housing body 11 is provided with a support 12 having a workpiece placement surface 29 at a position one step higher than the surroundings. As shown in FIG. 3, the support 12 includes an outer peripheral edge that is concentric with the housing body 11, and a plurality of urethane linings 40 are radially formed on the upper surface, that is, the work placement surface 29, centering on the processing center. It is dotted with. These urethane linings 40 function not only to prevent the work 30 from slipping, but also function to prevent the work 30 from sticking due to the attracting action of a magnet 46 described later.

The rotation shaft 25 of the clamper 26 is arranged at equal intervals around the support base 12 on the upper surface 28 of the upper wall 28 of the housing body 11 with an angular difference of 90 ° in the circumferential direction around the processing center. A stepped recess 41 is provided on the lower surface of the clamper 26, and the outer peripheral edge of the support base 12 is released by the stepped recess 41 during clamping.
A cam 42 having a substantially circular shape is mounted on the rotary shaft 25 of the clamper 26. The cam 42 penetrates the rotary shaft 25 at the center, and the upper surface thereof is arranged substantially in parallel with the lower surface of the upper wall 28 of the housing body 11 with a slight gap. As shown, a cam groove 43 is provided around the center of rotation. The cam groove 43 is provided with a cam surface 44 having a predetermined gradient in the thickness direction, and a cam follower 45 provided in a magnetic force attracting means described later is movable along the cam surface 44.

  When the clamper 26 is in an unclamped state, the cam follower 45 abuts against the non-cam surface on the lower surface of the cam 42 and causes the magnetic force attracting means to stand by at a position away from the support base 12 (corresponding to the separation position of the present invention). On the other hand, when the clamper 26 rotates in the clamping direction (the arrow direction shown in FIG. 4), the cam 42 mounted on the rotation shaft 25 of the clamper 26 rotates in conjunction with the cam follower 45 so that the cam follower 45 It enters the groove 43 and moves along the cam surface 44, thereby bringing the magnetic force attracting means closer to the support base 12 side.

  The magnetic force attracting means includes a magnet 46 such as a permanent magnet disposed in the housing main body 11 so as to face the lower surface of the upper wall 28 of the support base 12 with a slight gap, and a mounting plate 48 for holding the magnet 46. Yes. As shown also in FIG. 6, two pairs of notch edges 49 are provided on the outer periphery of the mounting plate 48 so as to be substantially parallel across the axis, and corresponding cams 42 are arranged along the notch edges 49. In addition, a cam follower 45 is provided that protrudes substantially horizontally from each notch edge 49 outward in the radial direction. Four guide shafts 80 pass through the outer edge of the mounting plate 48 substantially vertically, and the mounting plate 48 can move up and down along each guide shaft 80. As shown in FIG. 2, an urging member 85 such as a spring is wound around each guide shaft 80, and the urging member 85 is formed on the lower surface of the mounting plate 48 and the lower wall 24 of the housing body 11. It is inserted between the upper surface and urges the mounting plate 48 upward, that is, toward the support base 12 side.

  Further, four stopper bolts 81 are fixed to the mounting plate 48 while penetrating from below to above. A stopper 82 that can come into contact with the stopper bolt 81 is disposed on the lower surface of the upper wall 28 of the housing main body 11 so that the tip of the stopper bolt 81 abuts against the tip of the stopper 82 so that the mounting plate 48 moves upward. Are now regulated. The magnet 46 is closest to the support 12 at a position where the magnet 46 is abutted against the stopper 82, and the work 30 is attracted and held at this position (corresponding to the approach position of the present invention). The separation distance between the tip of the stopper bolt 81 and the tip of the stopper 82 corresponds to the moving stroke amount of the mounting plate 48, and this moving stroke amount can be appropriately changed by adjusting the screwing amount of the stopper bolt 81. Yes.

  Next, the operation of this embodiment will be described. First, a work 30 to be polished, for example, a disk-shaped work (magnetic material) is generally positioned and placed on the work placement surface 29 of the support base 12. The actuator 60 is pressurized, and the rotational force is transmitted to the rotary shaft 25 via the drive shaft 13, the drive gear 21, and the driven gear 22. As the rotary shaft 25 rotates, the clamper 26 and the cam 42 rotate integrally.

When the cam 42 rotates, the cam follower 45 enters the cam groove 43 and moves along the cam surface 44 as shown in FIGS. 5 and 6. When the cam follower 45 rises the inclination of the cam surface 44, the mounting plate 48 is urged by the urging member 85 and rises toward the support base 12. When the stopper bolt 81 reaches a position where it comes into contact with the stopper 82, the ascending of the mounting plate 48 is stopped, and the mounting plate 48 is urged by the urging member 85 and is kept in this approach position. Further, the work 30 is attracted and held toward the support base 12 by the attracting action of the magnet 46, and its lifting is prevented.
During this time, the clamper 26 also rotates in synchronization with the cam 42, and the presser surface 27 of the clamper 26 abuts against the outer peripheral edge of the workpiece 30 by this rotation. In this state, when the clamper 26 further rotates in the clamping direction, as shown in FIG. 4, the pressing surface 27 of the clamper 26 presses the workpiece 30 from four directions in the centripetal direction, and the workpiece 30 is moved with its smooth clamping operation. Position and hold at the machining center. When the workpiece 30 is clamped with a constant clamping force, the rotation by the actuator 60 is automatically stopped.

  FIG. 7 shows the relationship between the clamp by the clamper 26 and the suction holding by the magnetic suction means based on the cam operation of the cam 42. In FIG. 7B, the circled portion indicated by the solid line shows a state in which the cam follower 45 faces the entrance 43A of the cam groove 43, and the magnet 46 is in the separated position at this position. Similarly, a circular portion indicated by a two-dot chain line in FIG. 7B shows a state in which the cam follower 45 has entered deeply into the cam groove 43, and the magnet 46 is in the approach position at this position. The angle display represents the rotation angle of the clamper 26, and 0 ° indicates the unclamped state when the clamper 26 is farthest from the workpiece 30. In the case of the present embodiment, by adjusting the gear ratio between the drive gear 21 and the driven gear 22, the clamper 26 is set to rotate 180 ° when the drive shaft 13 rotates 90 °. As shown in FIG. 7B, when the clamper 26 rotates approximately 45 ° and clamps the workpiece 30, the magnet 46 has already reached the approach position and holds the workpiece 30 by suction.

  Thereafter, the housing 51 is rotated together with the workpiece 30 by the operation of the motor 51, and in this state, the brushing device (not shown) is lowered from above, and the workpiece 30 is deburred by a brush assembled to the brushing device. When the processing of the workpiece 30 is completed, the brushing device is raised to the original position, the motor 51 is turned off, and the rotation of the housing body 11 is stopped. The unevenness of the brushing is corrected by rotating the housing main body 11 in the forward and reverse directions.

  Subsequently, the actuator 60 is pressurized so as to rotate in the opposite direction. Then, the clamper 26 rotates in the unclamping direction with an operation opposite to the above, and is released from the workpiece 30 and released from the clamp. On the other hand, as the clamper 26 rotates in the unclamping direction, the cam follower 45 moves the cam surface 44 of the cam 42 toward the return direction, that is, toward the entrance 43A of the cam groove 43. Due to this movement, the mounting plate 48 is gradually lowered. However, when the cam follower 45 comes out of the cam groove 43 and reaches the non-cam surface, the mounting plate 48 is held at the separated position against the biasing force of the biasing member 85. . In the process in which the mounting plate 48 is lowered, the urging member 85 is compressed while accumulating the urging force. In addition, the workpiece 30 is removed from the support table 12 and conveyed to the next process at this separated position, and the next workpiece 30 is placed on the workpiece placement surface 29 of the support table 12.

  As described above, according to the present embodiment, when the workpiece 30 is clamped when the workpiece 30 is processed, the workpiece 30 is centered using the rotating cam operation of the clamper 26 disposed at equal intervals in the circumferential direction. Since the workpiece 30 is guided in the direction, the workpiece 30 can be easily and reliably positioned and held at the machining center. In this case, even if the diameter of the workpiece 30 is different, it can be dealt with, so that it is not necessary to change the setup each time the diameter of the workpiece 30 changes. Since the clamper 26 is constituted by an eccentric cam having a substantially circular shape, a smooth clamping operation can be realized, the centering accuracy can be improved, and a pressing surface whose radius from the shaft center is not constant is provided. The phase can be easily adjusted as compared with other variants.

  Further, since the cam 42 and the clamper 26 are mounted on the same rotating shaft 25, the actuator 60 performs driving for performing clamping of the clamper 26 and attracting and holding the magnet 46 based on the cam operation of the cam 42. As a result, the entire rotating device 25 can be simplified and miniaturized and the timing can be easily adjusted.

  Further, the mounting plate 48 is constantly urged upward by the urging member 85, and when the clamper 26 rotates in the unclamping direction, the urging member 85 is elastically compressed while accumulating the urging force. The mounting plate 48 can be kept on standby in the housing body 11 without rattling in the separated position.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described with reference to FIG. In the second embodiment, the mounting positions of the cam 42 and the cam follower 45 are different from those in the first embodiment, and the point that the urging member 85 is not provided is different from that in the first embodiment. Are denoted by the same reference numerals, and redundant description is omitted.

  In the second embodiment, a cam groove 43 is provided on the lower surface of the outer peripheral edge of the mounting plate 48, and a cam follower 45 is provided on the rotating shaft 25 of the clamp so as to protrude substantially horizontally. As shown in FIG. 9A, when the clamper 26 is in the unclamped state, the cam follower 45 enters the cam groove 43 and holds the mounting plate 48 in the separated position, while the clamper 26 faces in the clamping direction. As the cam rotates, the cam follower 45 moves along the inclination of the cam groove 43, and the mounting plate 48 rises with the movement. When the cam follower 45 comes out of the cam groove 43, the mounting plate 48 reaches the approach position and the work 30 is sucked and held. Thereafter, as shown in FIG. 9B, the workpiece 30 is positioned and held at the processing center based on the rotation cam operation of the clamper 26.

  According to the second embodiment, the mounting plate 48 can be always supported by the cam follower 45 even without the biasing member 85. However, in order to prevent the mounting plate 48 from rattling, a biasing member that constantly biases the mounting plate 48 downward between the upper surface of the mounting plate 48 and the lower surface of the upper wall 28 of the housing body 11. 85 may be inserted.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the above embodiment, four clampers are arranged around the support base. However, in the present invention, at least three clampers are arranged around the support base at equal intervals in the circumferential direction. It only has to be.
(2) In the above embodiment, the magnetic force attracting means is composed of the magnet and the mounting plate. However, in the present invention, the magnetic force attracting means may be composed only of the magnet.
(3) In the above embodiment, the workpiece is formed in a disc shape, but in the present invention, it can be applied to various workpieces regardless of the shape. In particular, since the clamper abuts on the outer peripheral edge of the work and guides the work in the centripetal direction, a flat work is preferable.

The longitudinal cross-sectional view of the workpiece clamp apparatus concerning Embodiment 1 of this invention Main part enlarged vertical sectional view showing a state in which the workpiece is clamped Plan view showing the state before clamping the workpiece Plan view showing the state after clamping the workpiece Cross section showing cam follower facing cam groove entrance Cross-sectional view showing a state where the cam follower is moving along the cam groove (A) Cross-sectional view of cam (B) Side view of cam Cross-sectional view showing drive gear and driven gear (A) Main part enlarged longitudinal cross-sectional view which shows the state before clamping a workpiece | work of the workpiece clamp apparatus concerning Embodiment 2 of this invention (B) Main part enlarged longitudinal sectional view which shows the state after clamping a workpiece | work.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Housing main-body part 12 ... Support stand 13 ... Drive shaft 25 ... Rotating shaft 26 ... Clamper 30 ... Workpiece 42 ... Cam 45 ... Cam follower 46 ... Magnet 48 ... Mounting plate

Claims (3)

A workpiece clamping device for clamping the workpiece when machining the surface of the workpiece,
A support base for placing the work; and at least three clampers that are arranged at equal intervals in the circumferential direction around the support base and clamp the work based on the rotating cam operation thereof;
The clamper has a pressing surface that abuts on the outer peripheral edge of the workpiece and can press the workpiece in the centripetal direction along with the rotation thereof ,
Magnetic adsorption means is disposed on the back side of the support base, and the magnetic adsorption means can be moved in a direction approaching or separating from the support base, so that the workpiece is attracted and held when in the approach position. It is possible to release the suction holding of the workpiece when it is in the separated position,
A cam is provided on one of the portion located on the rotation shaft of the clamper and the magnetic force attracting means, and a cam follower capable of engaging with the cam is provided on the other, and the cam follower is connected to the clamper. By moving along the cam surface of the cam accompanying rotation in the clamping direction, the magnetic force attracting means can be moved toward the approaching position, and the cam accompanying rotation in the unclamping direction of the clamper A work clamping device characterized in that the magnetic force attracting means can be moved toward the separated position by moving in the return direction along the cam surface .   The work clamp device according to claim 1, wherein the clamper is configured by an eccentric cam having a substantially circular shape. The magnetic force adsorbing means is constantly urged toward the support base by an urging member, and the urging member is elastically compressed while accumulating an urging force by rotating the clamper in the unclamping direction. is it possible that the workpiece clamping device according to claim 1 or claim 2, characterized in.

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