JP2015147288A - positioning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate attachment and detachment of a workpiece to/from a locating pin while enhancing positioning accuracy of the workpiece.SOLUTION: A positioning device 10 positions a workpiece having a locating hole, and includes: a support shaft member 21 arranged on a base member 16; a locating pin 20 which is arranged on the support shaft member 21 through a coil spring 28 and can move axially with respect to the support shaft member 21; and an enlarged-diameter arm 24 which is arranged on the locating pin 20 and can move radially with respect to the locating pin 20. A tapered surface 33 inclining to an axial direction of the support shaft member 21 is formed on at least one of the support shaft member 21 and the enlarged-diameter arm 24. When the locating pin 20 approaches the support shaft member 21 by contracting the coil spring 28, the enlarged-diameter arm 24 moves along the tapered surface 33 outward in a diameter direction. On the other hand, when the coil spring 28 is expanded and the locating pin 20 is separated from the support shaft member 21, the enlarged-diameter arm 24 moves along the tapered surface 33 inward in the diameter direction.

Description

  The present invention relates to a positioning device for positioning a workpiece having a locate hole.

  For example, an assembly line for an automobile body includes a main floor process for assembling a main floor, a body side process for assembling a body side, a main body process for fixing a body side to the main floor, and the like. In each of these processes, since various panel materials are combined and welded, a positioning device for positioning the panel material as a workpiece is used. In addition to the assembly line of the vehicle body, for example, in a transport device that transports the vehicle body, it is necessary to mount the vehicle body at an appropriate position. Therefore, a positioning device that positions the vehicle body as a workpiece is used ( Patent Document 1).

JP 2004-122950 A

  The positioning device described in Patent Document 1 mounts the vehicle body at an appropriate position on the transport hanger by inserting a locating pin into the locating hole of the vehicle body. However, since the locate pin has a cylindrical shape with a constant outer diameter, it is difficult to improve the positioning accuracy of the workpiece and to easily attach and detach the workpiece to and from the locate pin. That is, in order to increase the positioning accuracy of the workpiece, it is necessary to narrow the clearance between the locate pin and the locate hole. However, narrowing the clearance between the locating pin and the locating hole causes the locating pin to bite into the locating hole, which has been a factor that hinders the workpiece from being attached to and detached from the locating pin.

  An object of the present invention is to facilitate attachment / detachment of a workpiece with respect to a locating pin while increasing the positioning accuracy of the workpiece.

  The positioning device of the present invention is a positioning device for positioning a workpiece having a locating hole, and is provided with a support shaft member provided on a base member, and a spring member on the support shaft member. And a locating pin that is movable in the axial direction, and a diameter-expanding member that is provided on the locating pin and is movable in the radial direction with respect to the locating pin, the support shaft member and the diameter-expanding member At least one of them is provided with a cam surface that is inclined with respect to the axial direction of the support shaft member, and when the locate pin contracts the spring member and approaches the support shaft member, the cam surface is moved along the cam surface. While the diameter-expanding member moves radially outward, when the spring member is extended and the locating pin is separated from the support shaft member, the diameter-expanding member is radially inward along the cam surface. To move to.

  According to the present invention, when the locating pin contracts the spring member and approaches the support shaft member, the diameter-expanding member moves radially outward along the cam surface, while the spring member extends and extends from the support shaft member to the locating pin. When is separated, the diameter expanding member moves radially inward along the cam surface. As a result, the positioning accuracy of the workpiece can be increased, and the workpiece can be easily attached to and detached from the locate pin.

It is the schematic which shows the workpiece fixing jig provided with the positioning device which is one embodiment of this invention. (A)-(c) is explanatory drawing which shows the operation state of a workpiece | work fixing jig. (A) is a top view which shows a positioning device, (b) is a front view which shows a positioning device. It is an expanded sectional view which shows a positioning device along the AA line of Fig.3 (a). It is an expanded sectional view which shows a positioning device along the AA line of FIG. (A) is a plan view and a front view showing a support shaft member, (b) is a plan view and a front view showing three diameter-expanding arms, and (c) is a plan view and a front view showing three clamp arms. FIG. (A) And (b) is the top view and sectional drawing which show the operating state of a positioning device. (A) And (b) is the top view and sectional drawing which show the operating state of a positioning device. (A)-(d) is an expanded sectional view which shows the operating state of a diameter expansion arm. (A)-(d) is an expanded sectional view which shows the operating state of a clamp arm.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing a workpiece fixing jig 11 provided with a positioning device 10 according to an embodiment of the present invention. 2A to 2C are explanatory views showing the operating state of the workpiece fixing jig 11. First, as shown in FIG. 1, the workpiece fixing jig 11 includes a positioning jig portion 12 including a positioning device 10 and a clamp jig portion 14 including a clamping device 13. The positioning jig portion 12 is provided with a base member 16 fixed to the jig main body 15, and the positioning device 10 is fixed to the base member 16. The clamp jig 14 includes a cradle 17 that is fixed to the jig body 15 and an arm member 18 that is swingably provided on the cradle 17. A cylinder 19 is connected to the arm member 18, and by driving the cylinder 19, the arm member 18 can be swung between a clamp position and a release position.

  As shown in FIG. 2A, when the workpiece W is attached to the workpiece fixing jig 11, the arm member 18 is held at the release position. 2A, the workpiece W is conveyed toward the cradle 17, and the workpiece W is placed on the cradle 17, as shown in FIG. 2B. At this time, a locating pin 20 constituting the positioning device 10 is inserted into a locating hole Wa of the workpiece W described later, and the workpiece W is positioned at a predetermined position on the cradle 17. Subsequently, as shown by an arrow α in FIG. 2B, the arm member 18 is driven toward the clamp position, and as shown in FIG. 2C, the workpiece is placed between the cradle 17 and the arm member 18. W is fixed. Then, when processing such as welding or cutting on the workpiece W positioned and fixed is completed, the arm member 18 is driven toward the release position as shown by the arrow β in FIG. As indicated by arrow β, the workpiece W is removed from the cradle 17. In addition, when conveying the workpiece | work W, the robot arm etc. which are not shown in figure are used, for example.

  FIG. 3A is a plan view showing the positioning device 10, and FIG. 3B is a front view showing the positioning device 10. 4 is an enlarged sectional view showing the positioning device 10 along the line AA in FIG. 3A, and FIG. 5 is an enlarged sectional view showing the positioning device 10 along the line AA in FIG. It is.

  As shown in FIGS. 3A and 3B, the positioning device 10 includes a support shaft member 21 provided on the base member 16 and a locate pin 20 provided on the support shaft member 21. A plurality of slits 22 and 23 are formed in the locate pin 20, and an enlarged arm (expanded member) 24 and a clamp arm (clamp member) 25 are accommodated in the slits 22 and 23. As shown in FIG. 4, a support shaft member 21 is screwed to the base member 16, and a bullet-type locating pin 20 is provided on the support shaft member 21 so as to cover the tip thereof. Further, a shaft portion 26 is formed inside the locate pin 20, and a housing hole 27 for housing the shaft portion 26 of the locate pin 20 is formed in the support shaft member 21. One end portion of a coil spring (spring member) 28 is attached to the shaft portion 26 of the locate pin 20, and the other end portion of the coil spring 28 is accommodated in the accommodation hole 27 of the support shaft member 21. That is, the support shaft member 21 is provided with the locate pin 20 via the coil spring 28, and the locate pin 20 is movable in the axial direction with respect to the support shaft member 21. Further, as shown in FIG. 5, the locate pin 20 is formed with three slits 22 for accommodating the diameter-enlarged arms 24 at intervals of about 120 °. Similarly, the locate pin 20 is formed with three slits 23 for accommodating the clamp arm 25 every about 120 °. The slits 22 and the slits 23 are alternately arranged in the circumferential direction.

  Here, FIG. 6A is a plan view and a front view showing the support shaft member 21, and FIG. 6B is a plan view and a front view showing three diameter-expanding arms 24. FIG. These are a top view and a front view showing three clamp arms 25. In FIG. 6A, the alternate long and short dash line C <b> 1 indicates the central axis of the support shaft member 21. 6B and 6C, the alternate long and short dash line C2 indicates the central axis of the locate pin 20, the arrow α indicates the radially inward direction of the locate pin 20, and the arrow β indicates the radially outward direction of the locate pin 20. ing. When the support shaft member 21 and the locate pin 20 are assembled, the center axis C1 of the support shaft member 21 and the center axis C2 of the locate pin 20 are overlapped.

  As shown in FIG. 6A, the support shaft member 21 is provided between the male screw portion 30 provided on the proximal end side, the tapered portion 31 provided on the distal end side, and the male screw portion 30 and the tapered portion 31. And a collar portion 32. The tapered portion 31 of the support shaft member 21 is provided with three tapered surfaces (cam surfaces) 33 and three cylindrical surfaces 34 alternately in the circumferential direction. Further, the tapered surface 33 of the support shaft member 21 is inclined with respect to the central axis C <b> 1 of the support shaft member 21. That is, the tapered surface 33 of the support shaft member 21 is inclined with respect to the axial direction of the support shaft member 21. In addition, as shown in FIG. 6B, the three enlarged-diameter arms 24 are connected via an annular leaf spring 40. Each enlarged arm 24 includes an arm part 41 connected to the leaf spring 40, a projecting part 42 projecting radially outward from the tip of the arm part 41, and a copying part projecting radially inward from the arm part 41. 43. Furthermore, as shown in FIG. 6C, each clamp arm 25 includes a base portion 51 including a support pin 50, a claw portion 52 protruding radially outward from the base portion 51, and a radially inward direction from the base portion 51. And a protruding weight portion 53.

  As shown in FIG. 4, an annular leaf spring 40 that connects the enlarged arm 24 is attached to the shaft portion 26 of the locate pin 20. That is, the locating pin 20 is provided with an enlarged arm 24 via a leaf spring 40, and the enlarged arm 24 is movable in the radial direction of the locating pin 20 by elastically deforming the leaf spring 40. Further, the projecting portion 42 of the enlarged diameter arm 24 projects outward from the slit 22, and the copying portion 43 of the enlarged diameter arm 24 is in contact with the tapered surface 33 of the support shaft member 21. The copying portion 43 of the diameter-expanding arm 24 is in a state of being biased toward the tapered surface 33 by the leaf spring 40. The support pin 50 of the clamp arm 25 is attached to the locate pin 20, and the clamp arm 25 is rotatable with respect to the locate pin 20. Further, a concave portion 35 is formed in the cylindrical surface 34 of the support shaft member 21 facing the clamp arm 25, and an engaging projection 37 is assembled to the concave portion 35 together with a return spring 36.

  Next, the operating state of the positioning device 10 will be described. FIGS. 7A, 7 </ b> B, 8 </ b> A, and 8 </ b> B are a plan view and a cross-sectional view showing an operating state of the positioning device 10. 9A to 9D are enlarged sectional views showing the operating state of the diameter-expanding arm 24, and FIGS. 10A to 10D are enlarged sectional views showing the operating state of the clamp arm 25. . 9 (a) and 10 (a) show a part of FIG. 7 (a), and FIGS. 9 (b) and 10 (b) show a part of FIG. 7 (b). It is shown. 9 (c) and 10 (c) show a part of FIG. 8 (a), and FIGS. 9 (d) and 10 (d) show a part of FIG. 8 (b). It is shown.

  As shown in FIG. 7A, the inner diameter dimension D1 of the locate hole Wa opened to the workpiece W is set larger than the outer diameter dimension D2 of the locate pin 20. That is, a predetermined clearance is set between the locate hole Wa and the locate pin 20 in order to make it easy to insert and remove the locate pin 20 with respect to the locate hole Wa. As shown in FIG. 7A, before the locating pin 20 and the work W are fitted, no load is applied from the work W to the locating pin 20, so the locating pin 20 is supported by the spring force of the coil spring 28. It will be in the state away from. Then, as shown in FIG. 7B, when the fitting of the locate pin 20 and the workpiece W is started, the outer edge portion Wb of the locate hole Wa first contacts the protruding portion 42 of the diameter expansion arm 24. . Since the workpiece W and the locating pin 20 are in contact with each other through the diameter-enlarging arm 24 in this way, the workpiece W is lowered as shown in the order of FIGS. 7B, 8A, and 8B. Along with this, the locate pin 20 is lowered. That is, the locate pin 20 comes into a state of approaching the support shaft member 21 while the coil spring 28 is contracted as the work W is lowered.

  Here, as shown in the order of FIGS. 9A, 9 </ b> B, 9 </ b> C, and 10 </ b> D, when the locate pin 20 and the support shaft member 21 approach each other, along the tapered surface 33 of the support shaft member 21. Thus, the copying portion 43 of the diameter expanding arm 24 moves. That is, the copying portion 43 of the enlarged diameter arm 24 slides from the small diameter portion 60 of the tapered portion 31 toward the large diameter portion 61, so that the enlarged diameter arm 24 moves outward in the radial direction of the locate pin 20. At this time, as shown in FIG. 8B, since the three diameter-expanding arms 24 both move radially outward, the center C3 of the locating hole Wa can be aligned with the center C2 of the locating pin 20, and the locating pin 20 Therefore, it is possible to increase the positioning accuracy of the workpiece W. As described above, the clearance between the locate pin 20 and the locate hole Wa is reduced by the diameter-enlarging arm 24 that moves outward in the radial direction of the locate pin 20. It becomes possible to improve the positioning accuracy of W.

  On the other hand, when the workpiece W is lifted when the workpiece W is removed from the positioning device 10, the load applied from the workpiece W to the locate pin 20 decreases. Therefore, the locating pin 20 is lifted by the spring force of the coil spring 28 as shown in the order of FIG. 8B, FIG. 8A, and FIG. Here, as shown in the order of FIGS. 9D, 9C, 9B, and 9A, when the locate pin 20 and the support shaft member 21 are separated from each other, the large diameter portion 61 of the taper portion 31 has a small diameter. Since the copying portion 43 of the diameter expansion arm 24 slides toward the portion 60, the diameter expansion arm 24 moves inward in the radial direction of the locate pin 20. Thus, since a predetermined clearance is provided between the locate pin 20 and the locate hole Wa, the workpiece W can be easily detached from the locate pin 20. In addition, since the structure is such that the diameter expansion arm 24 is operated by a load applied to the locate pin 20 from the workpiece W, it is not necessary to incorporate an actuator or the like in the positioning device 10, and the positioning device 10 is simplified and reduced in cost. It becomes possible to do.

  Next, the operating state of the clamp arm 25 will be described. As shown in FIG. 10A, before the locating pin 20 and the work W are fitted, no load is applied from the work W to the locating pin 20, so that the locating pin 20 is supported by the spring force of the coil spring 28. It will be in the state away from. In this case, since the engagement protrusion 37 and the flange portion 32 of the support shaft member 21 are not in contact with the clamp arm 25, the clamp arm 25 is moved to the storage position in the slit 23. The center of gravity of the clamp arm 25 is set closer to the weight part 53 than the support pin 50. For this reason, in a situation where the engagement projection 37 and the collar portion 32 do not contact the clamp arm 25, the clamp arm 25 lowers the weight portion 53 and holds the retracted position.

  Further, as shown in FIG. 10B, when the locate pin 20 is lowered as the work W is lowered, the engagement protrusion 37 of the support shaft member 21 comes into contact with the weight portion 53 of the clamp arm 25 from below, and the clamp arm 25 is rotated in the direction of arrow α. At this time, the engaging protrusion 37 is accommodated in the concave portion 35 while the return spring 36 is contracted, so that the engaging protrusion 37 moves above the weight portion 53. Further, as shown in FIG. 10C, when the locate pin 20 is lowered as the work W is lowered, the flange portion 32 of the support shaft member 21 comes into contact with the weight portion 53 of the clamp arm 25 from below, and the clamp arm 25 Is rotated in the direction of arrow α. Then, as shown in FIG. 10D, the clamp arm 25 moves to the protruding position protruding from the slit 23, and the work W is regulated in the height direction by the claw portion 52 of the clamp arm 25. Thus, the workpiece W can be positioned in the Z-axis direction by the clamp arm 25, and the positioning accuracy of the workpiece W can be further increased. That is, since the workpiece W is positioned in the Z-axis direction by the clamp arm 25 as well as the workpiece W is positioned in the X-axis direction and the Y-axis direction by the locate pin 20 and the diameter expanding arm 24, the positioning accuracy of the workpiece W is increased. Can be dramatically improved.

  On the other hand, in order to remove the workpiece W from the positioning device 10, when the load applied to the locate pin 20 from the workpiece W is reduced and the locate pin 20 is raised by the spring force of the coil spring 28, as shown in FIGS. Further, the engagement protrusion 37 contacts the weight 53 of the clamp arm 25 from above, and the clamp arm 25 is rotated in the arrow β direction. Thereafter, as the locating pin 20 is raised, the engaging protrusion 37 is accommodated in the recess 35, so that the engaging protrusion 37 moves below the weight 53 as shown in FIG. It is held in the storage position. As described above, when the workpiece W is removed from the locate pin 20, the clamp arm 25 moves from the protruding position to the retracted position. Therefore, the workpiece W can be easily removed from the locate pin 20 without hindering the movement of the workpiece W by the clamp arm 25. Can be removed. In addition, since the clamp arm 25 is operated by the load acting on the locating pin 20 from the workpiece W, it is not necessary to incorporate an actuator or the like in the positioning device 10, and the positioning device 10 is simplified and reduced in cost. It becomes possible.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. In the illustrated case, one positioning device 10 is provided for the workpiece fixing jig 11, but the present invention is not limited to this, and a plurality of positioning devices 10 may be provided for the workpiece fixing jig 11. good. In the above description, three locating arms 24 are provided on one locating pin 20, but the present invention is not limited to this, and four locating arms 24 may be provided on one locating pin 20. Two or less diameter-expanding arms 24 may be provided on one locating pin 20. In order to make the center C2 of the locating pin 20 coincide with the center C3 of the locating hole Wa, it is desirable to provide three or more diameter expansion arms 24 for one locating pin 20. In the above description, three clamp arms 25 are provided on one locate pin 20, but the present invention is not limited to this, and four or more clamp arms 25 may be provided on one locate pin 20. Two or less clamp arms 25 may be provided on one locating pin 20.

  In the above description, the diameter expansion arm 24 is swingably provided with respect to the locating pin 20, but the present invention is not limited to this. The diameter-enlarging arm 24 may be provided so as to be movable in the radial direction with respect to the locating pin 20. In the above description, the clamp arm 25 is provided so as to be rotatable with respect to the locate pin 20. However, the present invention is not limited to this. For example, the clamp arm 25 may be swingably provided with respect to the locate pin 20.

  In the above description, the taper surface 33 as the cam surface is formed on the support shaft member 21. However, the present invention is not limited to this, and the cam surface may be formed on the diameter expansion arm 24. And a cam surface may be formed on both of the diameter expanding arm 24. Further, the cam surface is not limited to the tapered surface, and an inclined surface may be formed as the cam surface. Further, in the illustrated case, the flat workpiece W is positioned using the positioning device 10, but the present invention is not limited to this, and the positioning device of the present invention is applied to the pressed workpiece W. 10 may be applied. Further, in the illustrated case, the support shaft member 21 is provided for the base member 16 fixed to the jig main body 15. However, the support shaft member 21 is not limited to this and is directly supported by the jig main body 15. A shaft member 21 may be provided. That is, the jig body 15 may function as the base member 16.

DESCRIPTION OF SYMBOLS 10 Positioning device 20 Locating pin 21 Support shaft member 24 Diameter expansion arm (diameter expansion member)
25 Clamp arm (Clamp member)
28 Coil spring (spring member)
33 Tapered surface (cam surface)
42 Protrusion W Work Wa Locate hole Wb Outer edge

Claims (4)

A positioning device for positioning a workpiece having a locate hole,
A support shaft member provided on the base member;
A locating pin which is provided on the support shaft member via a spring member and is movable in the axial direction with respect to the support shaft member;
A diameter-expanding member provided on the locate pin and movable in a radial direction with respect to the locate pin;
Have
A cam surface that is inclined with respect to the axial direction of the support shaft member is formed on at least one of the support shaft member and the diameter-expanding member,
When the locate pin contracts the spring member and approaches the support shaft member, the diameter-expanding member moves radially outward along the cam surface,
The positioning device, wherein when the spring member extends and the locate pin is separated from the support shaft member, the diameter-expanding member moves radially inward along the cam surface. The positioning device according to claim 1,
The diameter-expanding member includes a protruding portion that protrudes radially outward of the locate pin,
A positioning device in which an outer edge portion of the locating hole comes into contact with the protruding portion when the locating pin is inserted into the locating hole of the workpiece. The positioning device according to claim 1 or 2,
The positioning device, wherein the locating pin is provided with three or more diameter-expanding members. In the positioning device according to any one of claims 1 to 3,
A clamp member that is provided on the locate pin and is movable between a protruding position protruding from the locate pin and a retracted position stored in the locate pin;
When the locate pin approaches the support shaft member, the clamp member moves toward the protruding position,
The positioning device, wherein the clamp member moves toward a retracted position when the locate pin moves away from the support shaft member.

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