JP3086121B2 - Work positioning jig - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work positioning jig, and in particular, has a reference hole at the center and two grooves 180.degree. The present invention relates to a work positioning jig for positioning a work at a center position with the reference hole, and positioning the work in an angular direction with respect to the center position at the center of the width of the two grooves.

[0002]

2. Description of the Related Art FIGS. 10 and 11 show the shape of a work to be processed by a work positioning jig according to the present invention. FIG.
Is a central sectional view passing through a reference hole and two grooves, and FIG.
0 is a plan view as viewed from the side of the reference hole of No. 0. In FIG.
The work 10 has a reference hole 12 at the center, and grooves 13 and 1 are provided at two positions 180 ° opposite to each other on the center line of the reference hole 12.
4 and the longitudinal direction of the grooves 13 and 14 is
It is formed in the direction. The measurement portion of the work 10 is the portion 15 on the opposite side of the reference hole 12 and the like, and the measurement standard is set as follows. That is, the work 10 is the end face 1
1, the thickness direction is determined, the center position is determined by the reference hole 12, and the angular direction with respect to the center position is determined by the center of the width of the grooves 13 and 14 at a predetermined radius from the center position. More specifically, when the work 10 is directed downward with the end face 11 facing down, the end face 1
1 is the Z-axis direction, the center of the reference hole 12 is the origin O,
Line L passing through centers Po and Qo of the widths of grooves 13 and 14
Designated values of the measurement portion 15 and the like are represented by defining the line Mo parallel to Lo and passing through the origin O as the X axis, and the line Mo passing through the origin O and perpendicular to the X axis as the Y axis.

[0003] As in the case of the work 10, there is a reference hole 12 at the center, and grooves 13 and 14 are provided at two places on the center line of the reference hole 12 opposite to each other by 180 °. Conventionally, a work positioning jig as shown in FIGS. 12 to 17 has been used to position a work formed in the direction. Hereinafter, these will be described, but in the work positioning jigs shown in FIGS. 12 to 17, a portion (work mounting table) for receiving the end face 11 is not shown. Further, the description will be made on the assumption that the gap between the reference shaft 61 for positioning the reference hole 12 and the reference hole 12 is so small as to be negligible in terms of positioning accuracy.

A work positioning jig 60 shown in FIG. 12 (a central sectional view passing through a reference hole and two grooves) and FIG. 13 (a plan view as viewed from the reference hole side) includes a fixed reference pin 62 and a preload spring. A pressing pin 63 urged in one direction by 65 (the pressing pin 63 rotates about a support shaft 64) is provided, and the reference pin 62 is inserted into the groove 13 and the pressing pin 63 is inserted into the groove 14, and the pressing pin is inserted. At 63, the work 10 is rotated about the reference axis 61, and the groove 13 of the work 10 is brought into contact with the reference pin 62 to determine the angular direction of the work 10. Thereby, the reference axis 6
1 and the line passing through the center Pa of the reference pin 62
Set to a.

[0005] A work positioning jig 70 shown in FIG. 14 (central sectional view in a direction perpendicular to a line passing through a reference hole and two grooves) and FIG. A slider 72 is provided so as to be movable in the reference axis 61 direction.
Two reference pins 73 are mounted on the opposite side of 0 °. The slider 72 is urged in the direction of the reference shaft 61 by a preload spring 74. As a result, the work 10 is pressed in one direction by the two reference pins 73 so that the grooves 13 and 14 are pushed in one direction.
The angle direction is determined by rotating about the reference shaft 61. The X axis set at this time is a line Mb passing through the origin O and being parallel to a line Lb passing through the centers Pb and Qb of the two reference pins 73.

A work positioning jig 80 shown in FIG. 16 (a central sectional view passing through a reference hole and two grooves) and FIG. 17 (a plan view as viewed from the reference hole side) has a tapered portion at the tip of the groove 13. The reference pin 82 is provided vertically by a pin guide 81 and is urged toward the workpiece 10 by a preload spring 83. Accordingly, the work 10 is rotated about the reference shaft 61 until the tapered portion of the reference pin 82 contacts both sides of the groove 13 to determine the angular direction, and the line Mc passing through the origin O and the center Pc of the reference pin 81 is determined. Is set as the X axis. In this jig, the groove 14 is not used for positioning.
Although not shown in detail, in this jig, a preload spring 83 is used.
In order to prevent the work 10 from being lifted by the pressing force of the preload spring 83, for example, the pressing force of the preload spring 83 is set to a pressure smaller than the weight of the work 10 or the work 10 is pressed from above.

[0007]

However, the work positioning jig 60 may have a difference between the width of the groove in which the reference pin 62 is engaged and the outer diameter of the reference pin 62 or the positional relationship between the two grooves. , The X-axis M set for the workpiece 10
There is a problem that an error occurs between o and the X-axis Ma set by the jig. When there is a difference between the width of the two grooves and the outer diameter of the reference pin 73, the work positioning jig 70 sets the X axis Mo set on the work 10 and the X axis Mb set on the work 10.
There is a problem that an error occurs in the above. Further, the work positioning jig 80 can be moved by two groove positions,
If the chamfer dimension of the groove entrance is large on both sides of the groove,
There is a problem that an error occurs between the X axis Mo set on the work 10 and the set X axis Mc.

The present invention has been made in view of such circumstances, and has a reference hole at the center and a groove having a center line direction groove at two positions 180 ° opposite to each other on the center line of the reference hole. While positioning the center position with the reference hole, 2
An object of the present invention is to provide a work positioning jig suitable for positioning an angular direction with respect to a center position at a width center of a groove at a location.

[0009]

SUMMARY OF THE INVENTION According to the present invention, there is provided a work having a reference hole at the center and two grooves 180.degree. Opposite to each other on the center line of the reference hole by 180.degree. A work positioning jig for positioning the center position with and positioning the angular direction with respect to the center position at the center of the width of the two grooves is set up on the base for mounting the work. (B) A reference hole positioning means for fixing the reference hole in the radial direction and supporting the reference hole so as to freely rotate is provided substantially at the center of the base. (C) A horizontal swing means capable of horizontally swinging in one direction is provided around the reference hole positioning means. (D) The horizontal swinging means is provided with groove engaging means contacting both sides of the two grooves of the work. The groove engaging means are disposed at two positions 180 ° opposite to each other with respect to the center of the reference hole positioning means in a direction substantially perpendicular to the swing direction of the horizontal swing means. (E) An operation arm for detaching the reference hole positioning means and the groove engaging means from the reference hole and two grooves of the work is movably provided on the base. The configuration was as described above.

The reference hole positioning means includes: (a) a reference shaft having a cylindrical portion at a lower portion and a tapered portion at an upper portion is fixed to the base; (B) A retainer is provided up and down on the outer periphery of the cylindrical portion of the reference shaft. (C) biasing means for biasing the retainer in a large diameter direction of the tapered portion of the reference shaft is provided. (D) Three or more balls are provided on the retainer so as to be movable in the radial direction of the reference axis. The configuration was as described above.

Further, the horizontal swing means is a parallel link mechanism.

A reference pin having a tapered portion at an upper portion and a cylindrical portion at an intermediate portion is provided on the horizontal rocking means, and the groove engaging means is substantially aligned with the rocking direction of the horizontal rocking means. 1 at right angles to the center of the reference axis
It is installed at two places on the opposite side of 80 °. (B) A vertically movable support block is provided along the cylindrical portion of the reference pin. (C) Two groove engaging pins having a semi-cylindrical upper outer shape and forming a substantially cylindrical shape are connected to the support block above the support block by a leaf spring, and the horizontal swing means swings. Provided to be freely openable and closable. (D) A preload spring for urging the support block downward is provided between the horizontal swing means and the support block. The configuration was as described above.

[0013]

According to the present invention, after the operating arm is operated to the non-positioning side, the reference hole is aligned with the position of the reference hole positioning means and the two grooves are positioned at the positions of the groove engaging means with the end face downward. At the same time, place the work on the work platform. Next, when the operation arm is operated to the positioning side, the center position of the work is positioned by the reference hole positioning means, and the work is freely rotated. At the same time, the two groove engaging means come into contact with the groove of the work, but the work rotates around the reference hole positioning means until the groove engaging means comes into contact with both sides of the two grooves of the work. At the same time, the position of the groove engaging means is horizontally swung by the horizontal swing means,
When the groove engaging means comes into contact with both sides of the two grooves of the work,
The positioning of the work is completed. As a result, a line passing through the centers of the two groove engaging means coincides with a line passing through the centers of the two grooves of the work. In this case, the horizontal swinging means provided with the groove engaging means swings in one direction and does not fluctuate in the other horizontal direction. Therefore, the horizontal swinging means always swings in parallel to a line passing through the center of the two groove engaging means. The line parallel to the line passing through the centers of the two groove engaging means and passing through the center of the reference hole positioning means is always constant.

[0014]

1 to 9 show a work positioning jig according to an embodiment of the present invention. 1 is an overall plan view, and FIG. 2 is a sectional view taken along the line AA of FIG. 1, wherein a left side from the center line is a state diagram before workpiece positioning, and a right side is a workpiece positioning state diagram. FIG. 3 is a cross-sectional view taken along the line BB of FIG. 2 and shows a state before positioning the workpiece. FIG. 4 is a cross-sectional view taken along the line CC of FIG. The state diagram before positioning of the workpiece is shown in the FFED sectional view. 6 is a detailed view of the groove engaging means 40, showing a state before the work is positioned, FIG. 7 is a detailed view of the groove engaging means 40, showing a work positioning state,
FIG. 8 is a view taken in the direction of the arrow G in FIG. 1, and FIG. 9 is an explanatory view of the center of the groove engaging means. In FIG. 1, a work positioning jig is provided with a reference hole positioning means 20 in the center, a horizontal swing means 30 around the reference hole positioning means 20, and a groove engaging means 40 on both sides of the reference hole positioning means 20 in the horizontal swing means 30. The three work mounting tables 22 are arranged at substantially equal distances from the center.

As shown in FIG. 2, in the center of the base 21,
A reference shaft 23 having a tapered portion 23a at an upper portion is fixed,
The retainer 2 is vertically movable around the outer periphery of the cylindrical portion 23b of the reference shaft 23.
The retainer 24 is provided with three balls 25 therein at intervals of about 120 ° on the circumference so as to be movable in the radial direction of the reference shaft 23. An operating pin 26 is fixed to both lower sides of the retainer 24 in the direction of the groove engaging means 40. Further, as shown in FIG. 4, the operating pin 26 is
8a, the biasing lever 28 is supported by a shaft 27 provided on the base 21 so as to be able to swing up and down, and a groove 28a with which the operating pin 26 is engaged by the preload spring 29 is lowered. It is biased in the direction. As a result, when an operation arm 52 to be described later is pulled out in the H direction, the operating pin 26
The retainer 24 descends until it comes into contact with the top end surface 53a of the third end. As a result, the retainer 24 is urged downward, the ball 25 moves in the large-diameter direction of the tapered portion 23a of the reference shaft 23, and the ball 25 moves outward by the tapered portion 23a of the reference shaft 23, and the workpiece 10 2 (right side in FIG. 2). Although not shown, the rotation of the retainer 24 is restricted by a detent pin provided on the reference shaft 23, and the ball 25 is prevented from coming off from the retainer 24 when the workpiece 10 is not present. Is formed slightly smaller than the diameter of the ball 25 outside the hole of the retainer 24.

The horizontal swing means 30 is a parallel link mechanism. As shown in FIGS. 1, 2, 3 and 4, a parallel link lower plate 31 is fixed to the outer periphery of the base 21.
, Two parallel link vertical plates 33, a parallel link upper plate 32 provided on the two parallel link vertical plates 33, and a parallel link lower plate 31, a parallel link vertical plate 33, and a parallel link vertical plate 33. And the parallel link upper plate 32 are connected by a cross leaf spring 34, respectively. Thereby, the parallel link upper plate 32 can swing freely in the horizontal direction. In this case, the swing direction of the parallel link upper plate 32 is set to be substantially perpendicular to a line passing through the centers of the two groove engaging means 40. A block 36 is provided to regulate the swing amount of the upper parallel link plate 32, and a stopper 37 is attached to the block 36, and a stopper 35 is attached to the upper parallel link plate 32.

Next, the groove engaging means 40 will be described.
As shown in FIGS. 2 and 7, brackets 38 are fixed to both sides of the lower surface of the parallel link upper plate 32.
Are respectively fixed with reference pins 41. Reference pin 41
Has a tapered portion at the top and a cylindrical portion at the middle.
A support block 42 is provided outside the reference pin 41 along the cylindrical portion of the reference pin 41 so as to be vertically movable.
Two groove engaging pins 44 are mounted above the two. The lower part of the groove engaging pin 44 is attached to the support block 42 by a leaf spring 43 so as to be freely opened and closed. The upper part is a semi-cylindrical shape, forming a substantially cylindrical tube with two pieces. The center of 41 is located. The support block 42 is urged downward by a preload spring 45, and when the operation arm 52 described later is pulled out in the H direction, the support block 42 is moved to the fork portion 5 of the operation arm 52.
The support block 42 is lowered until it comes into contact with the top surface 54a of the front end of the support block 4. As a result, the inside (between two) of the groove engaging pins 44 abuts on the tapered portion of the reference pin 41, and the groove engaging pins 44
Opens outward and abuts both sides of the work groove. A tapered portion is formed in the vicinity of the semi-cylindrical tip above the groove engaging pin 44, and when the groove engaging pin 44 opens and comes into contact with the groove of the work 10, a boundary between the tapered portion and the semi-cylindrical portion is formed. Since the semi-cylindrical portion does not come into contact with 44a, it is not affected by the chamfer dimension of the entrance of the groove of the work 10.

Further, as shown in FIG. 8, a guide 51 is formed on the base 21 in the swinging direction of the parallel link upper plate 32, and an operation arm 52 is provided movably along the guide 51. As shown in FIGS. 3, 5 and 6, two forks 53 for engaging with the operating pin 26 and two forks 54 for engaging with the support block 42 are formed at the tip of the operation arm 52. . The operation arm 52 is the work 1
At the time of attachment / detachment, the ball 25 is separated from the reference hole 12 of the work 10 and the groove engaging pin 44 is separated from the grooves 13 and 14.

As described above (see FIG. 4), when the operating arm 52 is pulled out in the H direction, the retainer 24 is lowered by the preload spring 29 until the operating pin 26 comes into contact with the upper end surface 53a of the fork portion 53. The ball 25 moves in the large-diameter direction of the tapered portion 23a of the reference shaft 23, and the ball 2
5 moves outward by the tapered portion 23a of the reference shaft 23 and comes into contact with the reference hole 12 of the work 10, but when the operation arm 52 is pushed in the I direction as shown in FIG. Engage with the operating pin 26 to move the retainer 24 upward against the preload spring 29,
The ball 25 is easily moved in the small diameter direction of the tapered portion 23a of the reference shaft 23, the contact force of the ball 25 on the work 10 is reduced, and the reference hole 12 of the work 10 is
From the vehicle becomes easy.

Further, as described above (see FIG. 7), when the operating arm 52 is pulled out in the H direction, the support block 42 is preloaded by the preload spring until the lower surface of the support block 42 contacts the upper surface 54a of the tip end of the fork portion 54. 45, the groove engaging pin 4 is inserted into the tapered portion of the reference pin 41.
4, the groove engagement pin 44 opens outward and contacts the groove of the work. As shown in FIG. 6, when the operation arm 52 is pushed in the I direction, the fork portion 54 is pressed. Since the support block 42 moves upward against the preload spring 45 on the upper surface 54b of the groove, the groove engaging pin 44 is
Of the work 10 is removed, and the work 10 is easily separated from the grooves 13 and 14.

When positioning the work 10 with the work positioning jig configured as described above, the operator pushes the operation arm 52 in the I direction, turns the end face 11 downward, and sets the reference hole 12 in the reference hole positioning. The work 10 is placed on the work placing table 22 by adjusting the position of the means 20 and the grooves 13 and 14 to the position of the groove engaging means 40.
Next, the operation arm 52 is pulled out in the H direction. As a result, the retainer 24 moves down, the ball 25 moves outward, and the ball 25 comes into contact with the reference hole 12 of the work 10 to position the center of the work 10. At the same time, the support block 42 moves downward, and the inside of the groove engaging pin 44 contacts the tapered portion of the reference pin 41 and opens outward. The workpiece 10 rotates around the reference shaft 23 until it abuts on both sides of the groove, and the groove engaging pin 44 is rotated by the parallel link mechanism.
Is swung horizontally, and all four groove engaging pins 4
4 contacts both sides of the grooves 13 and 14 of the work,
The positioning of the work 10 is completed. After this, the reference axis 23
Is set as the X axis, and the line passing through the origin in parallel with the line passing through the centers of the two groove engaging pins 44 is set as the origin.
Measure etc.

In this case, the center P of the groove engaging pin 44
And Q are two groove engaging pins 44 as shown in FIG.
Are the middle points of the distances Ta and Tb outside the boundary 44a between the tapered portion and the semi-cylindrical portion in the vicinity of the tip. However, since it is difficult to accurately determine this point, usually, a reference work having the same shape as the measurement work in advance and each dimension having a known dimension is installed on the work positioning jig according to the present invention, and the reference work is measured.
Set based on the measurement result.

Further, since the parallel link upper plate 32 provided with the groove engaging means 40 swings in one direction and does not fluctuate in the other direction, the centers P and Q of the two groove engaging pins 44 are adjusted. The passing line L always swings in parallel, and the line passing through the origin (the center of the reference axis 23) parallel to the line L passing through the centers P and Q of the two groove engaging pins 44 is always constant.

In the embodiment, the reference shaft 23 and the work 1
Although the contact of the reference hole 12 of 0 was performed by the ball 25,
However, the present invention is not limited to this, and other methods may be used as long as the mechanism allows the reference hole 12 to be rotatable while being fixed in the radial direction.

The case where the horizontal swing means 30 uses a parallel link mechanism has been described. However, if the groove engaging means 40 swings in one horizontal direction and does not fluctuate in other horizontal directions, a linear guide is used. Etc. may be used. The fulcrum of the parallel link is the cruciform leaf spring 34, but a fulcrum by a ball bearing or the like may be used as long as the fulcrum is small and the parallel link upper plate 32 can swing with a small force.

Further, in the embodiment, the inside of the groove engaging pin 44 and the tip of the reference pin 41 are engaged with each other by making the inside of the groove engaging pin 44 flat and the tip of the reference pin 41 tapered. Conversely, the tip of the reference pin 41 may be a column and the inside of the groove engaging pin 44 may be an inclined surface. When there is not much difference between the chamfer dimensions of the entrance of the groove of the work on both sides, the groove engaging means uses a reference pin as shown in FIGS. 16 and 17 of the conventional example, and the tapered portion of the reference pin is formed in the groove of the work. May be used.

[0027]

As described above, according to the work positioning jig according to the present invention, the center position O of the work 10 is positioned by the reference hole positioning means 20, and the work 10 can be freely rotated. At the same time, two groove engaging means 4
0 of the groove 10 of the work 10
And 14 come into contact with each other.
Until the workpieces 10 abut on both sides of the grooves 13 and 14, the work 10 rotates around the reference hole positioning means 20, and the position of the groove engaging means 40 swings horizontally by the horizontal swinging means 30. When all four groove engaging pins 44 of the groove engaging means 40 abut on both sides of the grooves 13 and 14 of the work 10, the positioning of the work 10 is completed. Accordingly, a line L passing through the centers P and Q of the two groove engaging means 40 and a line Mo passing through the centers Po and Qo of the two grooves 13 and 14 of the work 10 and passing through the center O of the reference hole 12.
Matches. In this case, since the horizontal swinging means 30 provided with the groove engaging means 40 swings in one direction and does not fluctuate in the other horizontal direction, a line passing through the centers P and Q of the two groove engaging means 40 L always swings in parallel, and a line parallel to the line L and passing through the center of the reference hole positioning means 20 is always constant.

Accordingly, the work 10 has a reference hole 12 at the center and two centerline grooves 13 and 14 at 180 ° opposite to each other on the centerline of the reference hole 12.
Is positioned at the center position O with the reference hole 12,
An optimal work positioning jig can be provided when positioning the angular direction with respect to the center position O at the centers Po and Qo of the two grooves 13 and 14.

[Brief description of the drawings]

FIG. 1 is a plan view of a work positioning jig according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG. 1, showing a state before the work is positioned on the left side from the center line, and a work positioning state on the right side from the center line.

FIG. 3 is a sectional view taken before the work positioning in a sectional view taken along line BB of FIG. 2;

FIG. 4 is a diagram showing a state of work positioning in a cross-sectional view taken along line CC of FIG. 3;

FIG. 5 is a sectional view before the workpiece is positioned in the DEFFFED sectional view of FIG. 3;

FIG. 6 is a detailed view of the groove engaging means, showing a state before positioning the work;

FIG. 7 is a detailed view of a groove engaging means, showing a work positioning state.

FIG. 8 is a view taken in the direction of arrow G in FIG. 1;

FIG. 9 is an explanatory view of the center of the groove engaging means.

FIG. 10 is a central sectional view passing through a reference hole and two grooves of a work.

FIG. 11 is a plan view seen from a reference hole side of a work.

FIG. 12 is a central sectional view of a first example of a conventional work positioning jig passing through a reference hole and two grooves.

FIG. 13 is a plan view of a first example of a conventional work positioning jig viewed from a reference hole side.

FIG. 14 is a central sectional view in a direction perpendicular to a line passing through a reference hole and two grooves of a second example of the conventional work positioning jig;

FIG. 15 is a plan view of a second example of a conventional work positioning jig as viewed from a reference hole side.

FIG. 16 is a central sectional view passing through a reference hole and two grooves of a third example of a conventional work positioning jig.

FIG. 17 is a plan view of the third example of the conventional work positioning jig as viewed from the reference hole side.

[Explanation of symbols]

 Reference Signs List 10 Work 20 Reference hole positioning means 21 Base 22 Work table 23 Reference shaft 24 Retainer 25 Ball 26 Operating pin 28 Urging lever 30 Horizontal swing Moving means 32: Upper plate of parallel link 38: Bracket 40: Groove engaging means 41: Reference pin 44: Groove engaging pin

Claims (2)

(57) [Claims] 1. A work having a reference hole in the center and grooves in the center line direction at two positions 180 ° opposite to each other on the center line of the reference hole is positioned at the center position by the reference hole. A work positioning jig for positioning an angular direction with respect to the center position at the center of the width of the two grooves, and a work mounting table provided on a base; A reference hole positioning means for supporting the reference hole positioning means so as to be rotatable while fixing a radial direction; a horizontal swing means provided around the reference hole positioning means and capable of horizontally swinging in one direction; and provided on the horizontal swing means. And at two positions 180 ° opposite to each other with respect to the center of the reference hole positioning means in a direction substantially perpendicular to the swinging direction of the horizontal swinging means, and at both sides of the two grooves of the work. Groove engaging hand A step, and the base is movably provided in the swinging direction of the horizontal swinging means, and a tip thereof is engaged with the reference hole positioning means and the groove engaging means, so that the tip is engaged with the reference hole of the work and two grooves. An operating arm for detaching the reference hole positioning means and the groove engaging means, wherein the reference hole positioning means is fixed to the base, has a cylindrical portion at a lower portion, and has a tapered portion at an upper portion. A retainer provided vertically on the outer periphery of the cylindrical portion of the reference shaft, and urging means for urging the retainer in a tapered portion large-diameter direction of the reference shaft; and a freely movable radial direction of the reference shaft to the retainer. The retainer is moved in the large diameter direction of the tapered portion of the reference shaft, so that the ball is engaged with both the reference shaft and the reference hole of the workpiece. The reference hole of the workpiece is positioned, and the groove engaging means is provided in the horizontal swing means, and is 180 ° opposite to the center of the reference axis in a direction perpendicular to the swing direction of the horizontal swing means. It is arranged at two places on the side and has a tapered part at the top,
A reference pin having a columnar portion formed at an intermediate portion; a support block provided up and down along the columnar portion of the reference pin; and a horizontal spring connected to the support block by a leaf spring above the support block. Two groove engaging pins which are provided so as to be able to freely open and close the swinging direction of the moving means, and whose upper outer shape is a semi-cylindrical and form a substantially cylindrical shape, are provided between the horizontal swinging means and the support block;
A preload spring for urging the support block downward, by the support block being moved downward,
The reference pin opens the groove engaging pin, the groove engaging pin engages with two grooves of the work, and the angular direction of the work is positioned. When the operation arm is pulled out in the horizontal direction, By moving the retainer in the tapered portion small diameter direction against the urging means of the reference hole positioning means, the first tip of the operation arm,
As the ball separates from the reference hole of the work, the second end of the operation arm pushes up the support block against the preload spring of the groove engaging means,
A work positioning jig wherein the groove engaging pins are separated from two grooves of the work. 2. The work positioning jig according to claim 1, wherein said horizontal swing means is a parallel link mechanism.