JP7564008B2 - Axis alignment jig - Google Patents

Description

The present invention relates to an axial alignment jig that aligns multiple workpieces based on their outer peripheral surfaces.

When two workpieces having outer peripheral surfaces are welded by butt welding, the two workpieces are aligned so that they are positioned on the same axis, as described in Patent Document 1, for example. When the two workpieces are each rod-shaped, the alignment of the workpieces is performed by inserting both workpieces into a guide part machined into a cylindrical shape and fitting the outer peripheral surfaces of both workpieces into the inner peripheral surface of the guide part. This type of machined guide part requires high precision during manufacturing, as the clearance between the workpieces must be as small as possible.

Japanese Patent Application Publication No. 11-267888

However, the method of aligning the axis using a cylindrical guide part cannot be implemented when the first to third workpieces 1 to 3 are welded at one location as shown in Figure 9. The first workpiece 1 is a circular plate. The second workpiece 2 and the third workpiece 3 are positioned on either side of the first workpiece 1 and have small diameter portions 2a, 3a that contact the first workpiece 1, and large diameter portions 2b, 3b whose outer diameters are larger than those of the small diameter portions 2a, 3a.

When butt welding the smaller diameter parts (first workpiece 1, small diameter parts 2a, 3a) than the largest outer diameter parts (large diameter parts 2b, 3b) of the first to third workpieces 1-3, even if the second and third workpieces 2, 3 are aligned at the large diameter parts 2b, 3b with the largest outer diameter using the cylindrical guide parts described above, it is not possible to align the first workpiece 1 with the smallest outer diameter. Furthermore, if the first workpiece 1 is aligned with the cylindrical guide parts, it becomes impossible to remove the guide parts after welding.

The object of the present invention is to provide an axial alignment tool that can accurately and easily align the axes of three workpieces even if the outer diameter of the workpiece located in the middle of the three workpieces is smaller than the other workpieces.

In order to achieve this object, the axial alignment jig of the present invention comprises a guide part consisting of a cylindrical body that accommodates multiple workpieces in a butted state, and a push-in part that is positioned on the same axis as the guide part and is fitted and pressed against one end of the guide part in the axial direction, the guide part having a first hole formed in the middle part in the axial direction, a second hole formed so that its hole diameter is larger than the hole diameter of the first hole on the one end side of the axial direction of the first hole, and a third hole formed so that its hole diameter is larger than the hole diameter of the first hole on the other end side of the axial direction of the first hole, and the peripheral wall of the other part of the guide part excluding the other end in the axial direction is formed by the A convex portion extending from the other end side of the cylindrical body toward one end side and a notch that opens the one end side are arranged in the circumferential direction, and the push-in part has a concave portion that fits into the convex portion of the guide part and a convex portion that fits into the notch of the guide part, and the fitting portion between the guide part and the push-in part has a cam surface that converts an axial pressing force applied to the push-in part toward the other end side in the axial direction into a radial pressing force that presses the peripheral wall of the guide part radially inward, and the application of the radial pressing force to the peripheral wall of the guide part causes the peripheral wall to elastically deform radially inward, and the inner diameter of the second hole becomes smaller.

In the present invention, in the axial alignment jig, the multiple workpieces include a first workpiece having an outer peripheral surface that can be fitted into the first hole and accommodated in the first hole, a second workpiece having a large diameter portion that can be fitted into the second hole and a small diameter portion that is equal to or smaller than the outer diameter of the first workpiece formed at one end of the large diameter portion, and accommodated in the second hole with the small diameter portion facing the first workpiece, and a third workpiece having a large diameter portion that can be fitted into the third hole and a small diameter portion that is equal to or smaller than the outer diameter of the first workpiece formed at one end of the large diameter portion, and accommodated in the third hole with the small diameter portion facing the first workpiece, and the hole diameter of the second hole may be a hole diameter in which the inner peripheral surface of the second hole is in close contact with the large diameter portion of the second workpiece by applying the radial pressing force to the peripheral wall of the guide part and elastically deforming the peripheral wall radially inward.

In the present invention, in the axial alignment jig, a through hole may be formed at a position corresponding to the first hole in the protruding portion of the peripheral wall.

In the axial alignment jig of the present invention, the convex portion of the guide part is formed in a mountain shape protruding in the axial direction and has an inclined portion extending from the protruding end to one side and the other side in the circumferential direction, and the cutout of the guide part may be formed in a V shape by the inclined portions of two adjacent convex portions of the guide part.

In the present invention, in the axial alignment jig, the portion of the guide part between the innermost portion of the notch and the other end of the cylindrical body may form a hinge portion that allows the protrusion of the guide part to expand radially outward.

In the present invention, the workpiece with the smallest outer diameter is fitted into the first hole, the other two workpieces are fitted into the second and third holes, and the part to be pushed into the guide part is pressed against it, causing the peripheral wall of the guide part to elastically deform radially inward, and the inner peripheral surfaces of the first to third holes are pressed against the first to third workpieces. This axis alignment jig also makes it possible to remove the first to third workpieces by elastically deforming the convex portion of the peripheral wall in the direction in which the outer diameter of the guide part expands.

Therefore, according to the present invention, it is possible to provide an axial alignment jig that can accurately and easily align the axes of three workpieces even if the outer diameter of the workpiece located in the middle of the three workpieces is smaller than the other workpieces.

FIG. 1 is a cross-sectional view showing a state in which an axial alignment jig according to the present invention is used. FIG. 2 is an exploded cross-sectional view of the axis alignment jig and the workpiece. FIG. 3 is a rear view of the guide part as seen from the pushing part side. FIG. 4 is a side view of the guide component. FIG. 5 is a front view of the pushing part as viewed from the guide part side. FIG. 6 is a side view of the push-in part. FIG. 7 is a perspective view of the axis alignment jig. FIG. 8 is a cross-sectional view showing a part of the push-in part and a part of the workpiece. FIG. 9 is a side view showing a workpiece for butt welding.

An embodiment of an axial alignment jig according to the present invention will now be described in detail with reference to Figures 1 to 8. The cutaway position of Figures 1 and 2 is the position shown by line II in Figure 4.
The axial alignment jig 11 shown in Fig. 1 is for aligning the axes of a plurality of workpieces 12 to 14 depicted in the center of Fig. 1, and is composed of a guide part 15 made of a cylindrical body depicted on the left side of Fig. 1, and a push-in part 16 positioned on the same axis as this guide part 15 and fitted into and pressed against one axial end 15a (the right end in Fig. 1) of the guide part 15. In the following description, the direction in which the push-in part 16 is located relative to the guide part 15 will simply be referred to as "one axial end side," and the opposite direction will be referred to as "the other axial end side."

The multiple workpieces 12 to 14 housed in the guide part 15 are parts of a sensor (not shown). As shown in Fig. 2, these workpieces 12 to 14 are the first workpiece 12, which has the shortest length in the axial direction of the guide part 15 (the left-right direction in Fig. 2), and the second and third workpieces 13, 14, which sandwich the first workpiece 12 from both sides in the axial direction of the guide part 15. The second workpiece 13 is located on one end side of the first workpiece 12 in the axial direction, and the third workpiece 14 is located on the other end side of the first workpiece 12 in the axial direction.
These first to third workpieces 12 to 14 are each formed from a metallic material, and are welded to one another at a location where the first workpiece 12 is located, after axial alignment is performed.

The first workpiece 12 is formed of a circular plate. In the following description, the outer diameter of the first workpiece 12 is simply referred to as the "first outer diameter."
The second workpiece 13 is formed in a cylindrical shape. The second workpiece 13 used in this embodiment has a cover 17 welded to one end in the axial direction in advance. A plurality of electrode pins 18 pass through the cover 17. The portion of the cover 17 through which the pins 18 pass is sealed by a hermetic seal 19.

The second workpiece 13 has a small diameter portion 13a located at the other end in the axial direction and a large diameter portion 13b extending from the small diameter portion 13a to one end in the axial direction. The small diameter portion 13a is formed so that the outer diameter is equal to or smaller than the first outer diameter, and contacts the first workpiece 12 from one end in the axial direction.
The outer diameter of the large diameter portion 13b is a second outer diameter that is larger than the first outer diameter. The outer diameter of one end of the large diameter portion 13b in the axial direction is smaller than the second outer diameter and is the same as the outer diameter of the cover body 17.

The third workpiece 14 is cylindrical and has a small diameter portion 14a located at one end in the axial direction and a large diameter portion 14b extending from the small diameter portion to the other end in the axial direction. The small diameter portion 14a is formed so that the outer diameter is equal to or smaller than the first outer diameter, and contacts the first workpiece 12 from the other end in the axial direction.
The outer diameter of the large diameter portion 14b is a third outer diameter that is greater than the first outer diameter. In this embodiment, the third outer diameter is the same as the second outer diameter.

The guide part 15 accommodates the first to third workpieces 12 to 14 in a butted relationship with each other. In this embodiment, the guide part 15 and the push-in part 16 are each formed from a plastic material. The plastic material forming the guide part 15 is a flexible material with a certain degree of pliability. The guide part 15 in this embodiment is formed from a plastic material with a tensile strength of 36 MPa and a bending strength of 81 MPa. An example of a plastic material with such properties is nylon-based resin.

As shown in FIG. 2, the guide part 15 has a first hole 21 formed in the middle part in the axial direction so that the inner diameter is smaller than other parts, and second and third holes 22, 23 formed on either side of the first hole 21. The opening shape of the first to third holes 21 to 23 is circular. In addition, the first to third holes 21 to 23 are formed on the same axis.

The first hole 21 is formed so that the hole diameter is constant from one end to the other end in the axial direction. The hole diameter of the first hole 21 is a hole diameter into which the outer peripheral surface 12a of the first workpiece 12 can fit. The axial length of the first hole 21 is shorter than the combined axial length of the first workpiece 12 and the axial length of the small diameter portions 13a, 14a of the second and third workpieces 13, 14.

The second hole 22 is formed on one end side in the axial direction from the first hole 21. The second workpiece 13 is inserted into this second hole 22. The second workpiece 13 is inserted into the second hole 22 from one end side in the axial direction so that the small diameter portion 13a faces the first workpiece 12. The hole diameter of the second hole 22 is larger than the hole diameter of the first hole 21, and is a hole diameter into which the large diameter portion 13b of the second workpiece 13 can fit.

The hole diameter of the second hole 22 in this embodiment is set so that a predetermined clearance d is formed between the large diameter portion 13b of the second workpiece 13. This clearance d is a clearance that allows the second workpiece 13 to fit loosely into the second hole 22, and can be 0.1 mm to 0.2 mm.

The third hole 23 is formed on the other end side in the axial direction than the first hole 21. The third workpiece 14 is inserted into the third hole 23. The third workpiece 14 is inserted into the third hole 23 from the other end side in the axial direction so that the small diameter portion 14a faces the first workpiece 12. The hole diameter of the third hole 23 is larger than the hole diameter of the first hole 21 and is a hole diameter into which the large diameter portion 14b of the third workpiece 14 can fit.

The peripheral wall 24 of the guide part 15 that forms the first to third holes 21 to 23 is composed of a ring-shaped first peripheral wall 24a located at the other axial end 15b, and a second peripheral wall 24b that is the remaining part excluding the other axial end 15b. As shown in FIG. 7, the second peripheral wall 24b is formed by arranging a protrusion 31 that extends from the other axial end side to one end side of the guide part 15 in the axial direction, and a notch 32 that opens to the one axial end side, in the circumferential direction. In this embodiment, the protrusions 31 and the notches 32 are provided at positions that divide the peripheral wall 24 into four equal parts in the circumferential direction.

As shown in FIG. 4, the protrusion 31 is formed in a mountain shape that protrudes in the axial direction of the guide part 15. In this embodiment, the protrusion 31 has inclined portions 31a and 31b that extend from the protruding end to one side and the other side in the circumferential direction of the peripheral wall 24. A through hole 33 is formed in the protrusion 31 at a position corresponding to the first hole 21. The opening shape of the through hole 33 is a rectangle with two sides that extend following the inclined portions 31a and 31b of the protrusion 31.

The end faces of the protrusion 31 and the notch 32 on one axial end side form a first cam surface 34 that is inclined in the axial direction of the guide part 15. As shown in FIG. 2, the first cam surface 34 is inclined so that it is gradually positioned on the other axial end side as it moves radially outward of the guide part 15.

The notch 32 is formed in a V-shape by the inclined portions 31a and 31b of the two adjacent protrusions 31. The V-shape opens in the direction toward one end in the axial direction of the guide part 15. The notch 32 is formed so that the innermost portion 32a extends to the first peripheral wall 24a described above. The area between the innermost portion 32a of the notch 32 and the other end (the left end in FIG. 4) of the guide part 15 is part of the first peripheral wall 24a, and forms a hinge portion 35 that connects the two adjacent protrusions 31, 31 to each other. In more detail, the protrusion 31 can swing in the radial direction of the guide part 15 so that the distance between the protruding end and the large diameter portion 13b of the second work 13 increases or decreases as the hinge portion 35 twists due to elastic deformation, as shown in FIG. 8.

As shown in FIG. 7, the push-in part 16 is formed in a cylindrical shape having a recess 41 that fits into the protrusion 31 of the guide part 15 and a protrusion 42 that fits into the cutout 32 of the guide part 15. These recesses 41 and protrusions 42 are arranged alternately in the circumferential direction, similar to the protrusions 31 and cutouts 32 of the guide part 15.

The end faces of the other axial end of the recess 41 and the protrusion 42 of the push-in part 16 form a second cam surface 43 inclined in the axial direction. As shown in FIG. 2, the second cam surface 43 is inclined so as to be gradually positioned toward the other axial end as it moves radially outward of the push-in part 16. The angle of inclination of this second cam surface 43 with respect to the axial direction is such that the first cam surface 34 of the guide part 15 and the second cam surface 43 of the push-in part 16 overlap when the other axial end of the push-in part 16 is fitted into one axial end of the guide part 15 as shown in FIG. 1. In this embodiment, the first cam surface 34 and the second cam surface 43 correspond to the "cam surface" as defined in the present invention.

When the push-in part 16 is pushed toward the other end of the axial direction relative to the guide part 15 with the first cam surface 34 and the second cam surface 43 overlapping, the second cam surface 43 pushes the first cam surface 34, and the first cam surface 34 and the second cam surface 43 slide against each other, pushing the first cam surface 34 radially inward. That is, the first and second cam surfaces 34, 43 formed at the mating portion 44 (see FIG. 1) between the guide part 15 and the push-in part 16 convert the axial pressing force applied to the push-in part 16 toward the other end of the axial direction into a radial pressing force that presses the second peripheral wall 24b of the guide part 15 radially inward.

When a pressure force is applied radially inward to the second peripheral wall 24b of the guide part 15, the second peripheral wall 24b elastically deforms radially inward, reducing the inner diameter of the second hole 22. By reducing the inner diameter of the second hole 22 in this manner, the inner peripheral surface of the second hole 22 comes into close contact with the large diameter portion 13b of the second workpiece 13, and the first to third workpieces 12 to 14 are positioned on the same axis.

Therefore, according to this embodiment, it is possible to provide an axial alignment jig that can accurately and easily align the axes of the first to third workpieces 12 to 14 even if the outer diameter of the first workpiece 12 located in the center of the first to third workpieces 12 to 14 is smaller than the outer diameter of the second and third workpieces 13 and 14.

After the axial alignment is performed in this manner, temporary welding is performed to maintain this state. This temporary welding is performed by inserting a welding rod or welding tool (not shown) into the through hole 33 formed in the protrusion 31 of the guide part 15, and is performed so that the outer peripheral surface 12a of the first workpiece 12 and the small diameter portions 13a, 14a of the second and third workpieces 13, 14 are welded to each other at multiple positions in the circumferential direction.

After the temporary welding is performed, the push-in part 16 is removed from the guide part 15. Then, as shown in FIG. 8, the protruding end of the guide part 15 is pushed away from the second workpiece 13, and the protruding part 31 is swung so as to expand radially outward around the hinge part 35. By swung widely, the hole diameter of the first hole 21 of the guide part 15 is expanded, and the third workpiece 14 can pass through the first hole 21, so that the first to third workpieces 12 to 14 can be removed from one end side of the axial direction of the guide part 15. The first to third workpieces 12 to 14 can be removed from the guide part 15 by cutting the hinge part 35 and expanding the guide part 15. In this case, the guide part 15 is disposable, so that a new guide part 15 can always be used when making multiple assemblies consisting of the first to third workpieces 12 to 14. In other words, the guide part 15 will not deteriorate due to increased use, which will result in a decrease in the accuracy of the axis alignment.

The multiple workpieces according to this embodiment are composed of first to third workpieces 12 to 14. The first workpiece 12 has an outer peripheral surface 12a that can fit into the first hole 21, and is housed in the first hole 21. The second workpiece 13 has a large diameter portion 13b that can fit into the second hole 22, and a small diameter portion 13a that is smaller than the outer diameter of the first workpiece 12 is formed at one end of the large diameter portion 13b, and is housed in the second hole 22 with the small diameter portion 13a facing the first workpiece 12.

The third workpiece 14 has a large diameter portion 14b that can fit into the third hole 23, and a small diameter portion 14a that is smaller than the outer diameter of the first workpiece 12 is formed at one end of the large diameter portion 14b, and is accommodated in the third hole 23 with the small diameter portion 14a facing the first workpiece 12.
The hole diameter of the second hole 22 is such that the inner surface of the second hole 22 is in close contact with the large diameter portion 13b of the second workpiece 13 when a radial pressing force is applied to the peripheral wall of the guide part 15, causing the peripheral wall to elastically deform radially inward.
Therefore, the diameter of the second hole 22 can be formed to allow the second workpiece 13 to be easily inserted, and the operation of inserting the second workpiece 13 into the second hole 22 can be easily performed.

In this embodiment, a through hole 33 is formed at a position corresponding to the first hole 21 of the protrusion 31 of the guide part 15. Therefore, the outer periphery of the first workpiece 12 is exposed through the through hole 33, so that the outer periphery of the first workpiece 12 can be temporarily fixed to the second and third workpieces 13 and 14 by welding.

The convex portion 31 of the guide part 15 in this embodiment is formed in a mountain shape protruding in the axial direction, and has inclined portions 31a, 31b extending from the protruding end in one direction and the other direction in the circumferential direction. The notch 32 of the guide part 15 is formed in a V shape by the inclined portions 31a, 31b of the two adjacent convex portions 31 of the guide part 15. Therefore, the fitting portion 44 between the guide part 15 and the push-in part 16 extends in the axial direction and the circumferential direction of the guide part 15, and the first and second cam surfaces 34, 43 of this fitting portion 44 can be formed over the entire circumferential area. Therefore, when the push-in part 16 is pressed against the guide part 15, the second peripheral wall 24b is elastically deformed approximately evenly over the entire area.

In this embodiment of the guide part 15, the portion between the innermost portion 32a of the notch 32 and the other end of the guide part 15 (cylindrical body) constitutes a hinge portion 35 that allows the protrusion 31 of the guide part 15 to expand radially outward. Therefore, the protrusion 31 of the guide part 15 can be expanded radially outward, and the first to third workpieces 12 to 14 inside the guide part 15 can be easily removed.

In the above-described embodiment, an example has been described in which temporary welding is performed after the first to third workpieces 12 to 14 have been aligned. However, by clamping the first to third workpieces 12 to 14, which have been aligned, from both sides in the axial direction using a holding device (not shown), it is possible to remove the guide part 15 and the push-in part 16 from the first to third workpieces 12 to 14 without temporary welding. In this case, it is possible to weld the outer periphery of the first workpiece 12 to the small diameter parts 13a and 14a of the second and third workpieces 13 and 14 over the entire circumference (perform real welding) without temporary welding.

11...Axis alignment jig, 12...First workpiece, 12a...Outer periphery, 13...Second workpiece, 13a, 14a...Small diameter portion, 13b, 14b...Large diameter portion, 14...Third workpiece, 15...Guide part, 16...Push-in part, 21...First hole, 22...Second hole, 23...Third hole, 24b...Second peripheral wall, 31...Convex portion, 31a, 31b...Inclined portion, 32...Notch, 33...Through hole, 34...First cam surface, 35...Hinge portion, 41...Concave portion, 43...Second cam surface, 44...Fitting portion.

Claims (5)

A guide part having a cylindrical body that accommodates a plurality of workpieces in a state where the workpieces are butted against each other;
a push-in part that is positioned coaxially with the guide part and is fitted and pressed against one end of the guide part in the axial direction,
The guide part is
a first hole formed in the axially intermediate portion;
a second hole formed on one end side of the first hole in the axial direction such that a hole diameter of the second hole is larger than a hole diameter of the first hole;
a third hole formed on the other end side of the first hole in the axial direction such that the hole diameter is larger than the hole diameter of the first hole,
A peripheral wall of the guide part other than the other end in the axial direction is formed by circumferentially arranging a convex portion extending from the other end side of the cylindrical body toward the one end side and a notch that opens to the one end side,
the pushing part has a recess that fits into the protrusion of the guide part and a protrusion that fits into the notch of the guide part,
The fitting portion between the guide part and the push-in part has a cam surface that converts an axial pressing force applied to the push-in part toward the other end side in the axial direction into a radial pressing force that presses the peripheral wall of the guide part toward the radially inward direction,
An axis alignment jig characterized in that, when a radial pressing force is applied to the peripheral wall of the guide part, the peripheral wall elastically deforms radially inward, thereby reducing the inner diameter of the second hole. The axial alignment jig according to claim 1,
The plurality of workpieces include
a first workpiece having an outer peripheral surface that can be fitted into the first hole and that is accommodated in the first hole;
a second workpiece having a large diameter portion that can be fitted into the second hole, and a small diameter portion that is equal to or smaller than the outer diameter of the first workpiece formed at one end of the large diameter portion, the second workpiece being accommodated in the second hole with the small diameter portion facing the first workpiece;
a third workpiece having a large diameter portion that can be fitted into the third hole, a small diameter portion that is equal to or smaller than the outer diameter of the first workpiece formed at one end of the large diameter portion, the small diameter portion being placed in the third hole with the small diameter portion facing the first workpiece;
An axial alignment jig characterized in that the hole diameter of the second hole is such that the inner surface of the second hole comes into close contact with the large diameter portion of the second workpiece when the radial pressing force is applied to the peripheral wall of the guide part, causing the peripheral wall to elastically deform radially inward. The axial alignment jig according to claim 1 or 2,
The axis alignment jig, characterized in that a through hole is formed in the protruding portion of the peripheral wall at a position corresponding to the first hole. In the axial alignment jig according to any one of claims 1 to 3,
The convex portion of the guide component is formed in a mountain shape protruding in the axial direction and has an inclined portion extending from a protruding end to one side and the other side in the circumferential direction,
The axis alignment jig, characterized in that the notch of the guide part is formed in a V-shape by the inclined portions of two adjacent protrusions of the guide part. The axial alignment jig according to claim 4,
An axial alignment jig characterized in that the portion of the guide part between the innermost portion of the notch and the other end of the cylindrical body forms a hinge portion that allows the convex portion of the guide part to expand radially outward.

Images