JP5461829B2 - Centering device - Google Patents

Description

  The present invention relates to a centering device used for setting the center of a workpiece when processing a workpiece such as a crankshaft for an automobile engine, for example.

  In general, when a workpiece such as a crankshaft for an automobile engine is manufactured, the workpiece is integrally formed by casting and forging, and then the workpiece is centered, that is, the center position of the workpiece is set. And the center hole is formed in the axial end part of a workpiece | work with tools, such as a drill, in the setting state of the center position of this workpiece | work. After that, necessary processing is performed on the workpiece using the center hole as a processing reference.

Conventionally, as this kind of workpiece centering device, for example, a configuration as disclosed in Patent Document 1 has been proposed. In this conventional apparatus, a measuring station for measuring the center of inertia of the workpiece and a processing station for forming a center hole in the workpiece based on the measurement result are provided. In the measurement station, the work center is rotated at high speed while being held between a pair of holding disks, and the vibration generated in the vibration frame is measured to obtain the center of inertia of the work. In the processing station, a center hole as a processing reference is formed at or near the inertia center of the shaft end portion of the workpiece by a tool such as a drill.
JP 2002-18658 A

  However, this conventional apparatus requires a special measuring station for measuring the center of inertia of the workpiece, and there is a problem that the configuration of the entire apparatus becomes complicated. Further, in the processing station, it is necessary to move and adjust the position of the tool based on the inertial center data measured by the measuring station, so that there is a problem that the configuration of the processing station becomes complicated.

  The present invention has been made paying attention to such problems existing in the prior art. The purpose is that there is no need to provide a measuring mechanism for measuring the center of inertia of the workpiece, the center of the workpiece can be set by gripping the outer periphery of the workpiece, and the configuration can be simplified. Is to provide.

  In order to achieve the above object, the present invention provides a centering device for setting the center of a workpiece, and a pair of first grips capable of opening and closing that grip the outer periphery of the workpiece at two positions 180 degrees apart in the circumferential direction. A pair of second grips that can be opened and closed that grip the member and the outer periphery of the workpiece 180 degrees apart from each other in the circumferential direction at positions different from the positions gripped by the first gripping member. A member, a single drive means for opening and closing the first and second gripping members, a transmission means provided between the drive means and the first and second gripping members, and in the transmission means Provided with an allowance means for allowing a difference in operation amount between the first gripping member and the second gripping member.

  Therefore, in the present invention, when the driving means is operated in a state where the workpiece is disposed between the first and second gripping members in the open state, the first and second gripping members approach via the transmission mechanism. Be operated. As a result, the outer periphery of the work is gripped by the pair of first gripping members at two positions that are 180 degrees apart in the circumferential direction. At the same time, the outer periphery of the work is gripped by the pair of second gripping members at two positions that are 180 degrees apart in the circumferential direction at positions different from the first gripping member in the circumferential direction.

  For this reason, even when the outer periphery of the workpiece is not formed into a perfect circle, the center position of the workpiece can be set by gripping the outer periphery of the workpiece with each pair of gripping members. Therefore, unlike the conventional apparatus, it is not necessary to provide a measurement mechanism for measuring the center of inertia of the workpiece, and the configuration can be simplified.

  The said structure WHEREIN: It is good to provide the 1st actuating means which act | operates said pair of 1st holding member with an equal operation stroke, and the 2nd actuating means which act | operates said pair of 2nd holding member with an equal operation stroke. When configured in this way, the pair of first gripping members and the pair of second gripping members are operated with the same operation stroke, and appropriately grip the outer periphery of the workpiece at two positions 180 degrees apart in the circumferential direction. be able to. Therefore, the center position of the workpiece can be set accurately.

  In the above configuration, the first and second actuating means include a pinion rotated by driving of the driving means and a rack provided on the first and second gripping members so as to mesh with the pinion. Good.

  The said structure WHEREIN: It is good to provide the holding member group which consists of a pair of said 1st holding member and a pair of 2nd holding member in two places away in the axial direction of the workpiece | work. When configured in this way, even a workpiece that is long in the axial direction can be gripped at two locations separated in the axial direction by a pair of gripping member sets, and the center position of the workpiece can be set. Can be done accurately.

  In the above-described configuration, it is preferable to provide another permissive means that allows a difference in the operation amount between the two gripping member sets.

  The said structure WHEREIN: It is good to provide the positioning means for positioning the said workpiece | work in the axial direction. When configured in this way, the outer periphery of the workpiece can be gripped by the first and second gripping members in a state where the workpiece is positioned in the axial direction by the positioning means, and when the workpiece is gripped, It is possible to suppress the workpiece from moving in the axial direction. Therefore, the center position of the workpiece can be set accurately.

  The said structure WHEREIN: It is good to provide the temporary placement stand for temporarily placing the said workpiece | work between the 1st and 2nd holding members of the open state. When configured in this way, the workpiece can be temporarily placed between the first and second gripping members in the open state by supporting the workpiece on the temporary placement table. Therefore, the work for setting the center position of the workpiece can be easily performed.

  As described above, according to the present invention, there is no need to provide a measurement mechanism for measuring the center of inertia of the workpiece, and the center of the workpiece can be accurately set by gripping the outer periphery of the workpiece with a simple configuration. Demonstrate that you can.

  Hereinafter, an embodiment of a centering apparatus embodying the present invention will be described with reference to the drawings.

  As shown in FIGS. 1, 2, and 8, a pair of left and right gripping members 22 </ b> A and 22 </ b> B for gripping a workpiece W such as a crankshaft at two locations separated in the axial direction are disposed on the frame 21. ing. As shown in FIGS. 6 and 7, each gripping member set 22A, 22B includes a pair of first gripping members 23a, 23b that can be opened and closed, and a pair of second gripping members 24a, 24b that can also be opened and closed. It is configured. The first gripping members 23a and 23b are opposed to each other in an inclined state at the front upper part and the rear lower part across the work W so as to grip the outer periphery of the shaft part Wa of the work W at two positions 180 degrees apart in the circumferential direction. ing. The second gripping members 24a and 24b grip the outer periphery of the shaft portion Wa of the workpiece W at two positions 180 degrees apart in the circumferential direction at positions different from the first gripping members 23a and 23b in the circumferential direction. Oppositely arranged in an inclined state in the upper rear part and the lower front part across the workpiece W.

  In this embodiment, the angle formed between the extending arrangement direction of the first holding members 23a and 23b and the extending arrangement direction of the second holding members 24a and 24b is set to 90 degrees. As a result, the outer periphery of the shaft portion Wa of the workpiece W is gripped by the first and second gripping members 23a, 23b, 24a, and 24b from both sides of the outer periphery at positions 90 degrees apart in the circumferential direction. Note that the angle formed by the extending arrangement direction of the first and second gripping members 23a, 23b, 24a, and 24b is not necessarily set to be 90 degrees, and the first gripping members 23a and 23b and the second gripping member are not necessarily set. An arbitrary angle can be set so that the gripping positions by the members 24a and 24b are different in the circumferential direction of the workpiece W. That is, in a state where the first gripping members 23a and 23b and the second gripping members 24a and 24b are opposed to each other by 180 degrees, between the adjacent first gripping member 23a and the second gripping member 24a, and It is possible to make an angle other than 90 degrees between the first holding member 23b and the second holding member 24b.

  As shown in FIGS. 1 to 3, a single opening / closing air cylinder 25 as a driving means is disposed in the center of the front portion of the frame 21 between the pair of gripping member sets 22 </ b> A and 22 </ b> B. A transmission mechanism 26 as a transmission means is provided between the piston rod 25a of the open / close air cylinder 25 and the first gripping members 23a and 23b and the second gripping members 24a and 24b of the pair of gripping members 22A and 22B. ing. The first and second gripping members 23a, 23b, 24a, and 24b of both gripping member sets 22A and 22B are simultaneously opened and closed through the transmission mechanism 26 by the retracting operation of the piston rod 25a of the opening and closing air cylinder 25. .

  As shown in FIGS. 3, 8 and 9, the transmission mechanism 26 includes a first permissive mechanism 27 </ b> A as a permissive means for permitting a difference in operation amount between the gripping member sets 22 </ b> A and 22 </ b> B, A second permissible mechanism 27B is provided as a permissive means for allowing a difference in operation amount between the first gripping members 23a, 23b and the second gripping members 24a, 24b in the gripping member groups 22A, 22B. .

  Incidentally, when the workpiece W is integrally formed by casting using a molding upper mold and a molding lower mold (not shown), it is caused by positional deviation between the molding upper mold and the molding lower mold, accuracy errors of both molds, and the like. The diameters of the shaft portions Wa at both ends of the work W are different, and as shown in FIGS. 13A and 13B, a stepped portion Wb is generated on the outer periphery of the shaft portion Wa of the work W. In many cases, the outer peripheral surface of Wa is not formed into a perfect circle. In such a case, the first gripping members 23a and 23b and the second gripping members 24a and 24b of the two gripping member groups 22A and 22B are moved close to each other by the same operating amount by the single opening / closing air cylinder 25. Then, the shaft portion Wa of the workpiece W may not be accurately gripped. In order to prevent the occurrence of such a problem, power is supplied from the opening / closing air cylinder 25 to the first and second gripping members 23a, 23b, 24a, and 24b of the gripping member groups 22A and 22B via the transmission mechanism 26. During the transmission, the first and second permissive mechanisms 27A and 27B cause the difference in operation amount between the two gripping member sets 22A and 22B and the difference between the first gripping members 23a and 23b and the second gripping members 24a and 24b. Differences in the amount of movement between are acceptable.

  Next, the transmission mechanism 26 and the permissive mechanisms 27A and 27B and their related configurations will be described in detail.

  As shown in FIGS. 1, 3, 7 and 8, a connecting member 28 is fixed to the lower end portion of the piston rod 25 a of the open / close air cylinder 25. A rotating lever 29 is supported at the center of the front surface of the frame 21 so as to be rotatable about a support shaft 30, and one end of the rotating lever 29 is connected to a connecting member 28 via a pin 31 so as to be relatively rotatable. Has been. Below the rotating lever 29, an intermediate member 32 is supported on the front surface of the frame 21 so as to be movable in the front-rear direction. 32b is formed. A side circular engagement portion 29 a is formed at the other end of the rotation lever 29, and this engagement portion 29 a is engaged with the engagement groove 32 a of the intermediate member 32 so as to be relatively movable. A guide rod 32c is projected from the intermediate member 32, and the guide rod 32c is inserted into a guide sleeve 21a provided on the frame 21 to guide the movement of the intermediate member 32 in the front-rear direction.

1, 3, 7 and 8, wherein the intermediate member 32 of the support groove 32b, rotating the support shaft 34 to the balance lever 33 extending in the lateral direction extending in the vertical direction at its central portion It is supported movably. The left and right ends of the balance lever 33, the support groove 33a extending in the vertical direction is formed. A restriction plate 35 is attached to the front end portion of the intermediate member 32. The left and right end portions of the regulating plate 35, engages the front of the balance lever 33, the pair of regulation screw 36 is located for restricting the rotation range of the balance lever 33 (projection amount) adjustably threaded It is worn.

When the piston rod 25a of the open / close air cylinder 25 is moved in and out, the rotation lever 29 is rotated between the position indicated by the solid line and the position indicated by the chain line in FIG. lever 33 is moved in the front-rear direction. In this case, in the support groove 32b of the intermediate member 32, relative rotation around the support shaft 34 of the balance lever 33 relative to the intermediate member 32 is allowed. In other words, the pivot structure of the balance lever 33, the first permitting mechanism 27A is constructed.

  As shown in FIGS. 6 and 7 to 10, four pinions 37 </ b> A, 37 </ b> B, 37 </ b> C, and 37 </ b> D are rotatably supported on the frame 21 below the gripping member sets 22 </ b> A and 22 </ b> B. Of these pinions 37A to 37D, two pinions 37A and 37B are disposed at the left and right positions along a single axis extending in parallel with the axis of the workpiece W in front of the lower part of the gripping member sets 22A and 22B. Further, the remaining two pinions 37C and 37D are disposed at the left and right positions along a single axis extending in parallel with the axis of the workpiece W at the lower rear of the gripping member sets 22A and 22B.

As shown in FIGS. 9 and 10, the frame 21 has a pair of left and right first racks 38 so as to mesh with the outer peripheral upper surfaces of the two pinions 37A and 37B located on the front side among the pinions 37A to 37D. It is supported via a pair of guide sleeves 39 and 40 so as to be movable in the front-rear direction. An engagement groove 38 a extending in the vertical direction is formed at the front end of each first rack 38. A pair of left and right interlocking rods 41 are supported on the frame 21 so as to be movable in the front-rear direction via the guide sleeves 42 so as to extend in parallel with the first racks 38 below the pinions 37A and 37B. With engaging grooves 41a at the front end extending in the vertical direction of each station kinematic rod 41 is formed, the connecting portion 41b of the semi-cylindrical is projected from the rear end.

As shown in FIGS. 9 and 10, wherein the rear of each station moving rod 41, two pinions 37C located on the rear side, to mate with the outer peripheral lower surface of 37D, a second rack pair to frame 21 43 is supported through a pair of guide sleeves 44 so as to be movable in the front-rear direction. Each the front end portion of the second rack 43, semicylindrical coupling part 43a which relatively slidably contact with the connecting portion 41b of each station moving rod 41 is protruded. Then, these connecting portions 41b, 43a are connected via a spring member, not shown, the operation of the continuous moving rod 41 is transmitted to the second rack 43 via the spring member. Therefore, the second rack 43 by resisting the elastic force of the spring member, relative movement is allowed for continuous kinematic rod 41.

As shown in FIGS. 1, 3, 7, and 9, in the support grooves 33 a at the left and right ends of the balance lever 33, a small scale 46 extending in the vertical direction is centered on a support shaft 47 at the center. Is rotatably supported. Side circular engagement portions 46a and 46b that engage with the engagement grooves 38a and 41a of the first rack 38 and the interlocking rod 41 are formed at the upper and lower ends of each small balance 46. A regulating plate 48 is attached to the front surface of each of the left and right ends of the balance lever 33. A pair of restriction screws for restricting the movement range of the first rack 38 and the interlocking rod 41 by engaging with the front end surfaces of the first rack 38 and the interlocking rod 41 at both upper and lower ends of each restriction plate 48. 49 is screwed so that position adjustment is possible.

  When the balance lever 33 is moved in the front-rear direction through the turning lever 29 in accordance with the projecting and retracting operation of the opening / closing air cylinder 25, the upper engagement portion 46a and the engagement groove 38a of the pair of small balances 46 are provided. And the pair of left and right first racks 38 and the interlocking rod 41 are moved in the front-rear direction through the engagement between the lower engagement portion 46b and the engagement groove 41a. As the first rack 38 moves, the two pinions 37A and 37B arranged on the front side are rotated clockwise or counterclockwise in FIG. Further, by the movement of the interlocking rod 41, the pair of second racks 43 are moved in the front-rear direction via the connecting portions 41b, 43a, and the two pinions 37C, 37D arranged on the rear side are counterclockwise in FIG. Rotate in the direction or clockwise, that is, in the opposite direction to the front-side pinions 37A and 37B.

In this case, when the balance lever 33 is rotated about the support shaft 34, the movement amounts of the left and right first racks 38 and the interlocking rod 41 are different. For this reason, in the left and right grip member sets 22A and 22B, the movement amounts of the grip members 23a, 23b, 24a, and 24b are different. Therefore, if the diameters of the shaft portions Wa at both ends of the workpiece W are different, the balance lever 33 is rotated around the support shaft 34, so that gripping is performed according to the difference in the diameters of the shaft portions Wa at both ends of the workpiece W. Differences in the movement amounts of the member sets 22A and 22B are allowed. In addition, by rotating each of the small balances 46 at both ends of the balance lever 33, relative movement between the first rack 38 and the interlocking rod 41 that are disposed corresponding to each other is allowed. Further, as described above, between the pair of left and right interlocking rods 41 and the second rack 43 corresponding to the rear thereof, relative sliding against the spring material occurs between the connecting portions 41b and 43a. Relative movement between the second rack 43 and the first rack 38 is allowed. That is, the second permissible mechanism 27B is configured by the rotating structure of the small balance 46 and the sliding structure between the connecting portions 41b and 43a. As a result, when the four pinions 37A to 37D are rotated in conjunction with each other by the single opening / closing air cylinder 25, relative rotation between the pinions 37A to 37D is allowed.

  As shown in FIGS. 6, 9, and 10, in each of the gripping member sets 22 </ b> A and 22 </ b> B, between the front-side pinions 37 </ b> A and 37 </ b> B and the pair of first gripping members 23 a and 23 b, the gripping members A first actuating mechanism 51 is provided as a first actuating means for actuating 23a and 23b with equal operation strokes by rotation of the pinions 37A and 37B. Similarly, in each gripping member set 22A, 22B, the gripping members 24a, 24b are also rotated between the pinion 37C, 37D on the rear side and the pair of second gripping members 24a, 24b by the rotation of the pinions 37C, 37D. A second operating mechanism 50 is provided as second operating means for operating with equal operating strokes.

  As shown in FIGS. 6, 9, and 10, in the second operating mechanism 50, the rear end side of the first gripping member 23 b of the pair of first gripping members 23 a and 23 b is arranged on the rear side. A rack portion 52 that meshes with the outer peripheral upper surfaces of the pinions 37C and 37D is formed. A first actuating rod 53 is movably supported on the frame 21 so as to extend in parallel with the upper first gripping member 23a of the pair of first gripping members 23a and 23b. A rack portion 54 that meshes with the outer peripheral lower surface of the rear-side pinions 37C and 37D is formed at the distal end portion of the first operating rod 53. A connecting plate 55 is attached between the base end portions (upper end portions) of the first operating rod 53 and the first gripping member 23a. When the pinions 37C and 37D are rotated in accordance with the movement of the opening / closing air cylinder 25, the pair of first gripping members 23a and 23b are opened and closed with the same operation stroke.

  Similarly, in the first operating mechanism 51, the rack that meshes with the outer peripheral upper surfaces of the front-side pinions 37A and 37B at the base end portion of the lower second holding member 24b of the pair of second holding members 24a and 24b. A portion 56 is formed. A second actuating rod 57 is movably supported on the frame 21 so as to extend in parallel with the upper second gripping member 24a of the pair of second gripping members 24a and 24b. A rack portion 58 that meshes with the outer peripheral lower surface of the front-side pinions 37A and 37B is formed at the tip of the second operating rod 57. A connecting plate 59 is attached between the base end portions (upper end portions) of the second operating rod 57 and the second gripping member 24a. When the pinions 37A and 37B are rotated in accordance with the retracting operation of the opening / closing air cylinder 25, the pair of second gripping members 24a and 24b are opened and closed with the same operation stroke.

  As shown in FIG. 4, FIG. 7, FIG. 8, FIG. 11 and FIG. 12, the work W is gripped by the grip members 23a, 23b, 24a, 24b on the frame 21 behind the grip member sets 22A, 22B. Prior to this, a positioning mechanism 61 is provided as positioning means for positioning in the axial direction. In the positioning mechanism 61, a pair of positioning members 62A and 62B are opened and closed via the rotation shafts 63A and 63B on the frame 21 so as to be able to engage with both inner side surfaces of the recess Wc formed in the workpiece W. It is rotatably supported. The rotary shafts 63A and 63B are provided with pinions 64A and 64B that mesh with each other.

  An operation shaft 65 is supported at the rear portion of the frame 21 so as to be movable up and down and is moved up and down by a positioning air cylinder 66 so as to be disposed behind the positioning members 62A and 62B. A cam member 67 is attached to the upper end portion of the operating shaft 65, and an inclined cam surface 67 a is formed on the front surface of the cam member 67. An operating rod 68 is supported by the frame 21 so as to be movable in the front-rear direction between the cam member 67 and one pinion 64A. A slidable contact portion 68a that is slidably contacted with the cam surface 67a of the cam member 67 is formed at the rear end portion of the operating rod 68, and a rack portion 68b that meshes with one pinion 64A is formed at the front end portion of the operating rod 68. Yes.

  When the cam member 67 is moved up and down by the positioning air cylinder 66 via the operation shaft 65, the operation rod 68 is moved in the front-rear direction by the cam action of the inclined cam surface 67a, and the rack portion 68a and the pinion 64A are moved. , 64B, the positioning members 62A, 62B are opened and closed. When the positioning members 62A and 62B are rotated to the open position, they are engaged with both side surfaces of the concave portion Wc on the workpiece W, and the workpiece W is positioned at a predetermined position in the axial direction.

  As shown in FIGS. 7 and 10, a pair of temporary placement tables 70 are disposed on the frame 21 outside the gripping member sets 22 </ b> A and 22 </ b> B. A side surface V-shaped support groove 70 a for supporting the shaft portion Wa of the workpiece W is formed at the upper end portion of each temporary placement table 70. Then, the work W is released by supporting the work W on the temporary table 70 in a state where the first and second gripping members 23a, 23b, 24a, 24b of the gripping member sets 22A, 22B are opened. It is temporarily placed between the first gripping members 23a and 23b in the state and between the second gripping members 24a and 24b.

  Next, the operation of the centering device configured as described above will be described.

  Now, in a state where the first gripping members 23a, 23b and the second gripping members 24a, 24b of the gripping member sets 22A, 22B are opened, a crankshaft or the like is placed on the pair of temporary placement tables 70 shown in FIGS. When the workpiece W is carried in and supported from above, the workpiece W is temporarily placed between the opened first and second gripping members 23a, 23b, 24a, and 24b.

When the positioning air cylinder 66 of the positioning mechanism 61 shown in FIGS. 7 and 8 is immersed in the temporary placement state of the workpiece W, the operation rod 68 is moved forward (by the action of the inclined cam surface 67a of the cam member 67). is moved to the right) in FIG. 8, the rack portion 68 b and the pinion 64A, through 64B, a pair of positioning members 62A, 62B is pivoted to the open position. By this rotation, the tip ends of the positioning members 62A and 62B are engaged with both inner side surfaces of the recess Wc on the workpiece W with a predetermined pressure, and the workpiece W is positioned at a predetermined position in the axial direction. That is, the workpiece W is positioned so that the center in the width direction of the concave portion Wc coincides with the center of the tip end portions of the positioning members 62A and 62B.

In positioning of the workpiece W, FIG. 3, when the 7 and the opening and closing air cylinder 25 shown in FIG. 8 or the like is projected operation, via a pivoting lever 29 and the intermediate member 32, the balance lever 33 is in the rear Moved. By the rearward movement of the balance lever 33, the first racks 38 are moved rearward (left side in FIG. 9) via the pair of left and right small balances 46, and the front pinions 37A and 37B are rotated counterclockwise in FIG. It is rotated. At the same time, the with the rearward movement of the balance lever 33, the connecting kinematic rod 41 and the second rack 43 via a pair of small balance 46 is moved rearward (the left side in FIG. 9), the rear side of the pinion 37C, 37D Is rotated clockwise in FIG.

  Due to the clockwise rotation of the rear pinions 37C and 37D, the lower first gripping member 23b of the gripping member sets 22A and 22B is directed to the work W via the rack portion 52 as shown in FIG. Moved closer. At the same time, the first operating rod 53 is moved in the opposite direction to the lower first gripping member 23 b via the rack portion 54, and the upper first gripping member 23 a is moved downward through the connecting plate 55. It is moved toward the workpiece W from the side opposite to the member 23b. As a result, in both gripping member sets 22A and 22B, the pair of first gripping members 23a and 23b are moved closer together with the same operation stroke, and the outer periphery of the two shaft portions Wa separated in the axial direction of the workpiece W is It is gripped at two positions 180 degrees apart.

  Further, due to the rotation of the front-side pinions 37A and 37B in the counterclockwise direction, as shown in FIG. 6, the lower second gripping member 24b in both gripping member sets 22A and 22B passes through the rack portion 56. The work is moved toward the workpiece W. At the same time, the second operating rod 57 is moved in the opposite direction to the lower second gripping member 24 b via the rack portion 58, and the upper second gripping member 24 a is moved downward through the connecting plate 59. It is moved toward the workpiece W from the side opposite to the member 24b. As a result, in both gripping member sets 22A and 22B, the pair of second gripping members 24a and 24b are moved closer to each other with the same operation stroke, and the outer circumferences of the two shaft portions Wa of the workpiece W are separated by 180 degrees in the circumferential direction. 2 positions, which are gripped at positions different from the grip positions by the first grip members 23a and 23b.

Thus, the first and second gripping members 23a outer periphery of the shaft portion Wa of each pair of works W, 23b, 24a, by being gripped at 24b, as shown in FIG. 13 (a) and (b) In addition, the center position C of the workpiece W is set. In this case, as described above, the diameters of the shaft portions Wa at both ends of the workpiece W are different, the stepped portion Wb is generated on the outer periphery of the shaft portion Wa of the workpiece W, and the outer peripheral surface of the shaft portion Wa is a perfect circle. May not be formed. In such a case, the movement amount of both gripping member sets 22A and 22B is the same by a single open / close air cylinder 25, or the first gripping members 23a and 23b of both gripping member sets 22A and 22B are the same as the second gripping. If the members 24a and 24b are moved closer to each other with the same movement amount, the shaft portion Wa of the workpiece W may not be accurately gripped.

  However, in the centering device of this embodiment, the first open / close air cylinder 25 and the first and second gripping members 23a, 23b, 24a, and 24b of the gripping member sets 22A and 22B have a first transmission mechanism 26. And the 2nd permissible mechanisms 27A and 27B are provided.

  For this reason, even if the diameters of the shaft portions Wa at both ends of the workpiece W are different, even if the outer peripheral surface of the shaft portion Wa is not formed in a perfect circle shape, both the gripping member sets 22A, While power is transmitted to the first and holding members 23a, 23b, 24a, 24b of 22B, the first and second permissible mechanisms 27A, 27B cause a difference in the amount of operation between the holding member sets 22A, 22B and a pair of Differences in the amount of movement between the first gripping members 23a and 23b and between the pair of second gripping members 24a and 24b are allowed. Therefore, the outer periphery of the shaft portion Wa of the workpiece W can be appropriately gripped by the pair of gripping members 23a, 23b, 24a, and 24b, and the center position C of the workpiece W can be accurately set.

  Then, in the set state of the center position C of the workpiece W, as shown in FIGS. 2 to 5 and 10, the tool (drill) 74 of the processing device 73 disposed opposite to both sides in the axial direction of the workpiece W is used. A center hole Wd is formed with respect to the center position C at both ends of the workpiece W. Thereafter, necessary processing is performed on the workpiece W using the center hole Wd as a processing reference.

  Therefore, the centering device of this embodiment can obtain the following effects.

  (1) In this embodiment, unlike the conventional apparatus, there is no need to provide a measurement mechanism for measuring the center of inertia of the workpiece, and the configuration of the apparatus can be simplified.

  (2) In this embodiment, the first operating mechanism 50 for equalizing the operation strokes of the pair of first gripping members 23a, 23b is provided, and the operation strokes of the pair of second gripping members 24a, 24b are equalized. A second actuating mechanism 51 is provided. For this reason, the pair of first gripping members 23a and 23b and the pair of second gripping members 24a and 24b are operated with the same operation stroke, and the outer periphery of the shaft portion Wa of the workpiece W is separated by two positions 180 degrees in the circumferential direction. Can be gripped appropriately.

  (3) In this embodiment, gripping member sets 22A and 22B composed of a pair of first gripping members 23a and 23b and a pair of second gripping members 24a and 24b are provided at two locations separated in the axial direction of the workpiece W. Has been placed. For this reason, even if the workpiece W is long in the axial direction, the workpiece W can be gripped simultaneously at two locations separated in the axial direction by the pair of gripping member sets 22A and 22B. Settings can be made quickly and accurately.

  (4) In this embodiment, a difference in the operation amount between the two gripping member sets 22A and 22B and a difference in the operation amount of the gripping members 23a, 23b, 24a, and 24b in each gripping member 22A and 22B are allowed. Even if the diameter Wa of the shaft portion of the workpiece W and the outer peripheral shape of the shaft portion Wa are not processed with high accuracy, the shaft portion Wa can be properly gripped and centered.

  (5) In this embodiment, a positioning mechanism 61 for positioning the workpiece W in the axial direction is provided. Therefore, if the workpiece W is positioned and held by the positioning mechanism 61 in the axial direction, the workpiece W is moved in the axial direction when the workpiece W is gripped by the first and second gripping members 23a, 23b, 24a, and 24b. It is possible to suppress floating.

  (6) In this embodiment, a temporary placement table 70 is provided for temporarily placing the workpiece W between the first and second gripping members 23a, 23b, 24a, 24b in an open state. For this reason, by supporting the workpiece W on the temporary placement table 70, the workpiece W can be temporarily placed between the first and second gripping members 23a, 23b, 24a, 24b in the open state, and the center position C of the workpiece W can be set. Can be easily set.

(Example of change)
In addition, this embodiment can also be changed and embodied as follows.

  In the above-described embodiment, another actuator such as a motor is used instead of the opening / closing air cylinder 25 as the driving means.

  In the embodiment, the interlocking rod 41 and the second rack 43 are integrated or fixed. Even in this configuration, the first gripping members 23a and 23b and the second gripping members 24a and 24b are allowed to function by allowing the difference in the operation amount between the small balance 46 and the rack 38 and the interlocking rod 41. It is possible to allow a difference in the amount of operation between the two.

  In the above-described embodiment, the gripping member sets 22A and 22B are provided at two locations, but provided at three or more locations.

The front view which shows the centering apparatus of one Embodiment. The top view of the centering apparatus of FIG. The perspective view which looked at the centering apparatus from the right front. The back view of a centering apparatus similarly. The perspective view which looked at the centering apparatus from the left side back surface. The principal part side sectional drawing of a centering apparatus similarly. FIG. 7 is an essential part cross-sectional view taken along line 7-7 in FIG. 6; Sectional drawing in the 8-8 line of FIG. Sectional drawing in the 9-9 line | wire of FIG. Sectional drawing in the 10-10 line | wire of FIG. The partial expanded sectional view in the 11-11 line | wire of FIG. The top view which expands and shows a part of FIG. (A) And (b) is a principal part expanded sectional view which shows the holding | grip operation | movement of the workpiece | work by a holding member.

Explanation of symbols

  22A, 22B ... gripping member set, 23a, 23b ... first gripping member, 24a, 24b ... second gripping member, 25 ... opening / closing air cylinder as drive means, 26 ... transmission mechanism as transmission means, 27A ... permission means First permitting mechanism as 27B ... Second permitting mechanism as allowing means, 29 ... Turning lever, 32 ... Rod, 33 ... Balance lever, 37A-37D ... Pinion, 38 ... First rack, 41 ... Interlocking rod, 43 ... second rack, 46 ... small balance, 50 ... first operating mechanism as first operating means, 51 ... second operating mechanism as second operating means, 52, 54, 56, 58 ... rack part, 53 ... First actuating rod, 55, 59 ... connecting plate, 57 ... second actuating rod, 61 ... positioning mechanism as positioning means, 62A, 62B ... positioning member, 66 ... positioning air cylinder, 70 ... Stand, W ... workpiece, Wa ... shank, Wc ... recess, Wd ... center hole, C ... central position.

Claims (6)

In the centering device for setting the center of the workpiece,
A pair of first gripping members capable of opening and closing to grip the outer periphery of the workpiece at two positions 180 degrees apart in the circumferential direction;
A pair of second gripping members capable of opening and closing to grip at a position different from the position gripped by the first gripping member at two positions 180 degrees apart from the outer periphery of the workpiece in the circumferential direction;
A single driving means for opening and closing the first and second gripping members;
Transmission means provided between the driving means and the first and second gripping members;
An accepting means provided in the transmitting means for allowing a difference in operation amount between the first gripping member and the second gripping member ;
First actuating means for actuating the pair of first gripping members with an equal operation stroke;
Second operating means for operating the pair of second gripping members with an equal operation stroke ;
The first and second actuating means are constituted by a pinion rotated by driving of the driving means and a rack provided on the first and second gripping members so as to mesh with the pinion. apparatus. In the centering device for setting the center of the workpiece,
A pair of first gripping members capable of opening and closing to grip the outer periphery of the workpiece at two positions 180 degrees apart in the circumferential direction;
A pair of second gripping members capable of opening and closing to grip at a position different from the position gripped by the first gripping member at two positions 180 degrees apart from the outer periphery of the workpiece in the circumferential direction;
A single driving means for opening and closing the first and second gripping members;
Transmission means provided between the driving means and the first and second gripping members;
Provided in the transmission means, and including an allowance means for allowing a difference in operation amount between the first gripping member and the second gripping member,
The pair of first gripping member and the pair of features and to Rousset Ntaringu device that provided become more gripping members of sets of the second gripping member at two positions spaced in the axial direction of the workpiece. The centering device according to claim 2 , further comprising another allowing means for allowing a difference in operation amount between the both gripping member sets. In the centering device for setting the center of the workpiece,
A pair of first gripping members capable of opening and closing to grip the outer periphery of the workpiece at two positions 180 degrees apart in the circumferential direction;
A pair of second gripping members capable of opening and closing to grip at a position different from the position gripped by the first gripping member at two positions 180 degrees apart from the outer periphery of the workpiece in the circumferential direction;
A single driving means for opening and closing the first and second gripping members;
Transmission means provided between the driving means and the first and second gripping members;
Provided in the transmission means, and including an allowance means for allowing a difference in operation amount between the first gripping member and the second gripping member,
The transmission means includes a balance lever connected at the central longitudinal to said drive means, and a small balance connected at the central portion to the both ends of the balance lever, and a rack which is connected to both ends of the small balance , a pinion meshing with the rack such that said meshes with the pinion first, features and to Rousset Ntaringu device more becomes possible with another rack formed on the second gripping member. The centering device according to any one of claims 1 to 4 , further comprising positioning means for positioning the workpiece in an axial direction thereof. The centering device according to any one of claims 1 to 5 , further comprising a temporary table for temporarily placing the workpiece between the first and second gripping members in an open state.

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