JP2020200910A - Manufacturing method of link mechanism and link mechanism - Google Patents

Abstract

To enhance joining rigidity by caulking a shaft and a yoke.SOLUTION: A jig 300 has: a non-restriction part 320 which is arranged while having a first adjoining part 1521 adjoining an opposing region 1523 to which a first yoke 171 at one end part 192 of a shaft 190 opposes at a main body part 191 side with a clearance in a part in at least a peripheral direction, and supports the first yoke 171; and a restriction part 310 arranged in a position continuing to the non-restriction part 320, and surrounding the main body part 191 of the shaft 190 over an entire periphery without a clearance. A manufacturing method of a link mechanism 200 includes: an arrangement process for arranging the shaft 190 in a position surrounded by the restriction part 310 and the non-restriction part 320, and making the non-restriction part 320 support the first yoke 171; and a pressing process for elastically deforming the first adjoining part 1521 of the shaft 190 by pressing one end face of the shaft 190 after the arrangement process, and making it protrude outwardly over the entire periphery.SELECTED DRAWING: Figure 6

Description

The present invention relates to a method for manufacturing a link mechanism and a link mechanism.

Generally, in an automobile, a steering shaft connected to a steering wheel and, for example, a pinion shaft as a steering gear shaft are connected via an intermediate shaft. The shaft and the yoke of the intermediate shaft are joined by, for example, one end of the shaft being crimped to the yoke (see, for example, Patent Document 1). Specifically, a step portion is formed in advance on the outer peripheral portion of one end portion of the shaft, and the tip end portion of the shaft is passed through the yoke so that the back surface portion of the yoke abuts on the step portion. When the tip of the shaft is crimped in this state, the yoke is sandwiched between the crimped portion and the stepped portion of the shaft, and the yoke and the shaft are joined.

Japanese Unexamined Patent Publication No. 2012-112509

By the way, in the caulking method described above, although the caulking portion is crimped to one end of the yoke, the stepped portion is simply in contact with the other end of the yoke, so that the joint strength is increased. There is a problem that it is difficult to raise.

Therefore, an object of the present invention is to provide a method for manufacturing a link mechanism capable of increasing the joint strength by caulking the shaft and the yoke.

In order to solve the above problems, the method for manufacturing a link mechanism according to one aspect of the present invention is a method for manufacturing a link mechanism including a shaft and a yoke, in which a yoke is assembled to a shaft held by a jig at the time of assembly. The shaft has a main body portion and one end portion which is continuous with the main body portion and the yoke is joined, and the jig has the main body with respect to the facing region where the yoke is opposed to the one end portion of the shaft. The first adjacent portion adjacent to the portion side is arranged with a gap at least in a part in the circumferential direction, and is arranged at a position continuous with the non-constrained portion supporting the yoke and the non-restrained portion of the shaft. It has a restraining part that surrounds the main body without gaps over the entire circumference, and the method of manufacturing the link mechanism is to arrange the shaft at a position surrounded by the restraining part and the non-binding part of the jig, and to surround the yoke as the non-binding part. By supporting the jig, the yoke is aligned with one end of the shaft, and after the placement process, by pressing one end of the shaft, the first adjacent portion of the shaft is plastically deformed to the outside. Includes a pressing step of projecting to.

Further, the link mechanism according to another aspect of the present invention includes a shaft and a yoke joined to the shaft, and the shaft is continuous with the main body portion and one end portion to which the yoke is joined. The first adjacent portion adjacent to the main body portion side with respect to the facing region facing the yoke at one end of the shaft protrudes outward in a state of being compressed in the axial direction.

According to the present invention, the joint strength between the shaft and the yoke by caulking can be increased.

It is a schematic diagram which shows an example of the use form of the intermediate shaft which concerns on embodiment. It is a top view which shows the schematic structure of the intermediate shaft which concerns on embodiment. It is a perspective view which shows the inner shaft and the 1st yoke which concerns on embodiment. It is sectional drawing which shows the state which the shaft and the 1st yoke which become the inner shaft after processing are set in the jig which concerns on embodiment. It is sectional drawing which shows the cross section including the Va-Va line in FIG. It is sectional drawing which shows the cross section including the Vb-Vb line in FIG. It is sectional drawing which shows the cross section including the Vc-Vc line in FIG. It is explanatory drawing which shows the state transition of the shaft in the pressing process which concerns on embodiment. It is explanatory drawing which shows the state transition of the shaft in the pressing process using the jig which concerns on modification 1. FIG. It is sectional drawing which shows the schematic structure of the unconstrained part which concerns on modification 2.

Hereinafter, embodiments will be specifically described with reference to the drawings. It should be noted that all of the embodiments described below are comprehensive or specific examples. Numerical values, shapes, materials, components, arrangement positions of components, connection forms, etc. shown in the following embodiments are examples, and are not intended to limit the present invention. In addition, among the components in the following embodiments, the components not described in the independent claims indicating the embodiment according to the present disclosure will be described as arbitrary components. The embodiment of the present disclosure is not limited to the current independent claims, but may be expressed by other independent claims.

In addition, the drawings are schematic views in which emphasis, omission, and ratio are adjusted as appropriate to show the present invention, and may differ from the actual shape, positional relationship, and ratio.

FIG. 1 is a schematic view showing an example of a usage embodiment of the intermediate shaft 100 according to the embodiment. As shown in FIG. 1, the intermediate shaft 100 is provided in the steering device 10 of an automobile. Specifically, the steering device 10 includes a steering shaft 12 to which a steering wheel 11 is connected to one end, and a rack and pinion mechanism including a pinion shaft 13 and a rack shaft 14, and a steering mechanism 16 for steering the steering wheel 15. And an intermediate shaft 100 that is interposed between the steering shaft 12 and the pinion shaft 13 to transmit steering torque.

One end of the intermediate shaft 100 is connected to the steering shaft 12 via a first universal joint 17. The intermediate shaft 100, the first universal joint 17, and the steering shaft 12 are examples of the link mechanism 200 according to the present invention. Further, the other end of the intermediate shaft 100 is connected to the pinion shaft 13 via a second universal joint 18.

When the steering wheel 11 is operated to rotate the steering shaft 12, the rotation is transmitted to the pinion shaft 13 and the rack shaft 14 via the intermediate shaft 100. As a result, the steering mechanism 16 steers the steering wheel 15.

Next, the intermediate shaft 100 according to the present embodiment will be described in detail.

FIG. 2 is a plan view showing a schematic configuration of the intermediate shaft 100 according to the embodiment. In the drawings after FIG. 2, an orthogonal coordinate system in which the X-axis direction is the axial direction of the intermediate shaft 100 is used. That is, the Y-axis direction and the Z-axis direction that are orthogonal to each other are also orthogonal to the X-axis direction. In the following description, the end on the minus side in the X-axis direction is referred to as one end, and the end on the plus side in the X-axis is referred to as the other end.

As shown in FIG. 2, the intermediate shaft 100 includes a stretchable intermediate shaft 110, a first universal joint 17 provided at one end of the intermediate shaft 110, and a second universal joint 17 provided at the other end of the intermediate shaft 110. It is provided with a universal joint 18. Note that FIG. 2 shows only the first yoke 171 which is a part of the first universal joint 17. The first universal joint 17 includes a first yoke 171, a second yoke coupled to the steering shaft 12 (not shown), and a cross shaft (not shown) connecting the first yoke 171 and the second yoke. .. Each shaft portion of the cross shaft is rotatably supported by the respective arms of the first yoke 171 and the second yoke via bearings (not shown).

The first yoke 171 is made of a metal such as iron or aluminum, and has a base portion 172 and a pair of arms 173. A through hole 174 (see FIG. 5 and the like) along the X-axis direction is formed in the center of the base portion 172. The cross-sectional shape of the through hole 174 in the X-axis direction corresponds to the cross-sectional shape of the inner shaft 150. In the present embodiment, the cross-sectional shape of the through hole 174 is a cross shape. The pair of arms 173 are portions of the base portion 172 extending from both ends in the Z-axis direction to the minus side in the X-axis direction. A pair of shaft portions on the cross shaft are rotatably supported by the pair of arms 173 via bearings (not shown).

Further, in FIG. 2, only the first yoke 181 which is a part of the second universal joint 18 is shown. The second universal joint 18 includes a first yoke 181, a second yoke coupled to the pinion shaft 13 (not shown), and a cross shaft (not shown) connecting the first yoke 181 and the second yoke. .. Each shaft portion of the cross shaft is rotatably supported by the respective arms of the first yoke 181 and the second yoke via bearings (not shown). Since the specific configuration of the first yoke 181 is the same as that of the first yoke 171 of the first universal joint 17, detailed description thereof will be omitted.

The intermediate shaft 110 includes an outer shaft 140 and an inner shaft 150. The first yoke 181 of the second universal joint 18 is joined to the other end of the outer shaft 140. The outer shaft 140 is a cylindrical shaft body made of a metal such as iron or aluminum, and has a through hole 141 at the center in the X-axis direction. The through hole 141 has a uniform cross-sectional shape over the entire length in the X-axis direction, but it does not have to be a uniform shape. The inner shaft 150 is slidably inserted in the through hole 141 from the plus side in the X-axis direction in the X-axis direction. The cross-sectional shape of the through hole 141 is such that the inner shaft 150 is slidable in the X-axis direction and the rotation around the X-axis direction is restricted. Specifically, the cross-sectional shape of the through hole 141 is a shape corresponding to the cross-sectional shape of the inner shaft 150. In the present embodiment, the cross-sectional shape of the through hole 141 is a cross shape.

FIG. 3 is a perspective view showing the inner shaft 150 and the first yoke 171 according to the embodiment. As shown in FIGS. 2 and 3, the inner shaft 150 is an example of a shaft according to the present invention, and is a rod-shaped shaft body made of a metal such as iron or aluminum. Specifically, the inner shaft 150 has a main body portion 151 and one end portion 152 continuous with the main body portion 151 and to which the first yoke 171 of the first universal joint 17 is joined.

The main body portion 151 has a non-circular cross-sectional shape in the X-axis direction, and has a uniform cross-sectional shape over the entire length. For example, the cross-sectional shape of the main body 151 is a cross shape. The cross-sectional shape of the main body 151 may be any shape as long as it is non-circular. Examples of other cross-sectional shapes include an elliptical shape, an oval shape, a polygonal shape, a Y-shape, and a star shape.

The base portion 172 of the first yoke 171 is joined to the one end portion 152. Specifically, the one end portion 152 has a first adjacent portion 1521 adjacent to the facing region 1523 on which the base portion 172 faces, on the main body portion 151 side, and the one end portion 152 on the side opposite to the main body portion 151 with respect to the facing region 1523. It has a second adjacent portion 1522 adjacent to it.

Specifically, the facing region 1523 is a region in which the outer peripheral surface of the one end portion 152 faces the inner peripheral surface forming the through hole 141 of the base portion 172. That is, the facing region 1523 is a region that is contained in the through hole 141 at one end portion 152.

The first adjacent portion 1521 and the second adjacent portion 1522 are compressed in the axial direction and project outward from the entire circumference of one end portion 152. As a result, the first adjacent portion 1521 and the second adjacent portion 1522 fix the base portion 172 by sandwiching the base portion 172 of the first yoke 171 in the X-axis direction.

The cross-sectional shape of the facing region 1523 at one end portion 152 in the X-axis direction is substantially the same size as that of the main body portion 151. On the other hand, the cross-sectional shapes of the first adjacent portion 1521 and the second adjacent portion 1522 are larger than those of the main body portion 151.

Next, the jig 300 used at the time of manufacturing the link mechanism 200 will be described.

FIG. 4 is a cross-sectional view showing a state in which the shaft 190 and the first yoke 171 which become the inner shaft 150 after processing are set in the jig 300 according to the embodiment. FIG. 5A is a cross-sectional view showing a cross section including the Va-Va line in FIG. FIG. 5B is a cross-sectional view showing a cross section including the Vb-Vb line in FIG. FIG. 5C is a cross-sectional view showing a cross section including the Vc-Vc line in FIG. In FIG. 4, the inner shaft 150 before processing is not shown in the cross-sectional view. As shown in FIGS. 4, 5A, 5B and 5C, the shaft 190 has a uniform cross-sectional shape as a whole in the axial direction. The shaft 190 is formed into a cross shape having a uniform cross-sectional shape as a whole in the axial direction by, for example, drawing.

As shown in FIG. 4, the jig 300 has a restraint portion 310 and a non-restraint portion 320 placed on the upper surface of the restraint portion 310.

The restraint portion 310 is a member made of a metal such as iron, and is arranged at a position continuous with the non-restraint portion 320 in the axial direction. An insertion hole 311 elongated in the X-axis direction into which the shaft 190 is inserted is formed on the upper surface of the restraint portion 310.

As shown in FIG. 5C, the cross-sectional shape of the insertion hole 311 in the X-axis direction is a shape corresponding to the cross-sectional shape of the shaft 190 so that the shaft 190 fits over the entire circumference. In the present embodiment, the cross-sectional shape of the insertion hole 311 is a cross shape. Further, the restraining portion 310 restrains the portion of the shaft 190 arranged in the insertion hole 311 by surrounding the portion without a gap over the entire circumference. Further, the shaft 190 inserted into the insertion hole 311 has one end portion 192 protruding from the upper surface of the restraint portion 310 (see FIG. 4). Here, the portion of the shaft 190 that fits within the restraint portion 310 is referred to as the main body portion 191.

The non-restraint portion 320 is a low-rigidity body having a lower rigidity than the shaft 190. Examples of the low-rigidity body include an elastic body such as rubber and a resin member. As shown in FIG. 5B, the non-restraint portion 320 is formed in an annular shape and surrounds the shaft 190 with a gap over the entire circumference. The non-restraint portion 320 may be a polygonal ring road, an elliptical ring road, or an oval ring road.

As shown in FIG. 4, a first yoke 171 in a state where one end portion 192 of the shaft 190 is penetrated through the through hole 174 is placed on the upper surface of the non-restraint portion 320. In this state, one end 192 of the shaft 190 is fitted into the through hole 174 of the first yoke 171 over the entire circumference (see FIG. 5A). One end surface of the shaft 190 projects from the base 172 of the first yoke 171. Here, of the one end portion 192 of the shaft 190, the portion corresponding to the non-restraint portion 320 is the first adjacent portion 1521, and the portion protruding from the base portion 172 is the second adjacent portion 1522, which is a portion that fits in the through hole 174. Is the facing region 1523. When the shaft 190 is set on the jig 300, the second adjacent portion 1522 is in an open state over the entire circumference. The state of being open over the entire circumference is a state in which another member (for example, the first yoke 171) is not in contact with the entire circumference of the second adjacent portion 1522.

Next, a method of manufacturing the link mechanism 200 will be described. Specifically, among the manufacturing methods of the link mechanism 200, a step of assembling the first yoke 171 to the inner shaft 150 (arrangement step and pressing step) will be described in detail. Here, the case where the operator assembles the first yoke 171 to the inner shaft 150 is illustrated, but the first yoke 171 may be automatically assembled to the inner shaft 150 by the assembling device. Even in that case, the first yoke 171 can be assembled to the inner shaft 150 by the same procedure.

First, in the placement step, the operator aligns the first yoke 171 with respect to one end 192 of the shaft 190. Specifically, the operator inserts the main body portion 191 of the shaft 190 into the insertion hole 311 of the restraint portion 310 in the jig 300, and causes one end portion 192 of the shaft 190 to protrude from the upper surface of the restraint portion 310. In this state, the shaft 190 is arranged at a position surrounded by the restrained portion 310 and the non-constrained portion 320 of the jig 300.

Specifically, the restraint portion 310 surrounds and restrains the portion of the shaft 190 arranged in the insertion hole 311 without a gap over the entire circumference. Further, the non-restraint portion 320 surrounds one end portion 192 of the shaft 190 with a gap over the entire circumference.

After that, the operator penetrates one end 192 of the shaft 190 into the through hole 174 of the first yoke 171 and then arranges the first yoke 171 on the upper surface of the unconstrained portion 320, whereby the first yoke 171 Is supported by the non-restraint portion 320. As a result, the state shown in FIG. 4 is obtained.

In the arranging step, the shaft 190 may be inserted into the first yoke 171 and the jig 300 after the first yoke 171 is installed on the jig 300. Further, the jig 300 may be fixed in advance at a predetermined position of the press machine during the placement process, or may be installed at another place during the placement process, and may be placed at a predetermined position of the press machine after the placement process. You may.

Next, the pressing process will be described. FIG. 6 is an explanatory diagram showing a state transition of the shaft 190 in the pressing process according to the embodiment. Specifically, FIG. 6A shows the state of one end 192 of the shaft 190 immediately after the start of pressing. FIG. 6B shows the state of one end portion 192 during pressing. FIG. 6C shows the state of one end portion 192 when the pressing is completed.

In the pressing step, the operator operates the press to press one end surface of the shaft 190 with the punch 400 of the press (see FIG. 6A). As the pressing by the punch 400 progresses, as shown in FIG. 6B, the main body portion 191 of the shaft 190 is constrained by the restraining portion 310, so that although it is compressed in the X-axis direction, it expands in the radial direction. Absent.

At one end 192, the opposing region 1523 is also constrained by the base 172 of the first yoke 171 so that it does not bulge in the radial direction. On the other hand, since the outer peripheral surfaces of the first adjacent portion 1521 and the second adjacent portion 1522 of the one end portion 192 are not constrained, they are plastically deformed and swell in the radial direction while being crushed in the X-axis direction. That is, the first adjacent portion 1521 and the second adjacent portion 1522 are plastically deformed so as to project outward over the entire circumference. At this time, since the second adjacent portion 1522 comes into contact with the base portion 172 of the first yoke 171, the first yoke 171 also advances in the pressing direction. As a result, the unconstrained portion 320 is also compressed and crushed in the X-axis direction, and the distance between the first yoke 171 and the restraint portion 310 in the X-axis direction is narrowed. Therefore, as shown in FIG. 6C, the first adjacent portion 1521 and the second adjacent portion 1522 are compressed in the X-axis direction and further expand in the radial direction. Therefore, the area of the first adjacent portion 1521 and the second adjacent portion 1522 to be crimped to the base portion 172 of the first yoke 171 is increased, and the bonding strength to the first yoke 171 is increased. As described above, the first adjacent portion 1521 and the second adjacent portion 1522 can be said to be caulked portions formed by compression. That is, the facing region 1523 can be said to be a region sandwiched between a pair of caulking portions in the one end portion 152.

In this way, the shaft 190 becomes the inner shaft 150 assembled to the first yoke 171 by the arranging step and the pressing step.

As described above, in the method of manufacturing the link mechanism 200 according to the present embodiment, the shaft 190 and the first yoke 171 are assembled with the first yoke 171 (yoke) attached to the shaft 190 held by the jig at the time of assembly. In the method for manufacturing the link mechanism 200 including the above, the shaft 190 has a main body portion 191 and one end portion 192 that is continuous with the main body portion 191 and to which the first yoke 171 is joined. , The first adjacent portion 1521 adjacent to the main body portion 191 side is arranged with a gap at least in a part in the circumferential direction with respect to the facing region 1523 in which the first yoke 171 at one end portion 192 of the shaft 190 faces. In addition, it has a non-constraining portion 320 that supports the first yoke 171 and a restraining portion 310 that is arranged at a position continuous with the non-constraining portion 320 and surrounds the main body portion 191 of the shaft 190 without a gap over the entire circumference. In the method of manufacturing the link mechanism 200, the shaft 190 is arranged at a position surrounded by the restraint portion 310 and the non-constraint portion 320 of the jig 300, and the first yoke 171 is supported by the non-restraint portion 320. By pressing one end surface of the shaft 190 after the arranging step of aligning the first yoke 171 with respect to one end portion 192 of the shaft 190 and the arranging step, the first adjacent portion 1521 of the shaft 190 is plastically deformed to the outside. It includes a pressing step of projecting toward the direction.

According to this, in the pressing step, by pressing one end surface of the shaft 190, the first adjacent portion 1521 of the shaft 190 is plastically deformed and projected outward, so that the first adjacent portion 1521 is , The surface (back surface) of the first yoke 171 on the main body 191 side is crimped. As a result, the joint strength between the shaft 190 and the first yoke 171 by caulking can be increased.

Further, the non-restraint portion 320 surrounds the first adjacent portion 1521 with a gap over the entire circumference, and in the pressing step, the first adjacent portion 321 of the shaft 190 is pressed by pressing one end surface of the shaft 190. It is plastically deformed and protrudes outward over the entire circumference.

According to this, in the pressing step, by pressing one end surface of the shaft 190, the first adjacent portion 1521 of the shaft 190 is plastically deformed and projected outward over the entire circumference. The adjacent portion 1521 is crimped to the surface (back surface) of the first yoke 171 on the main body portion 191 side over the entire circumference. As a result, the joint strength between the shaft 190 and the first yoke 171 by caulking can be further increased.

Further, the second adjacent portion 1522, which is adjacent to the facing region 1523 at one end portion 192 of the shaft 190 on the opposite side of the main body portion 191, is open over the entire circumference, and in the pressing step, one end surface of the shaft 190 is opened. By pressing, each of the first adjacent portion 1521 and the second adjacent portion 1522 of the shaft 190 is plastically deformed and projected outward over the entire circumference, and the protruding first adjacent portion 1521 and the second adjacent portion 1522 are formed. Hold the first yoke 171 with.

According to this, each of the first adjacent portion 1521 and the second adjacent portion 1522 is plastically deformed by one pressing and is projected outward over the entire circumference, so that the manufacturing time can be shortened. Further, since the first adjacent portion 1521 and the second adjacent portion 1522 are crimped to the first yoke 171 by sandwiching the first yoke 171 by caulking the shaft 190 and the first yoke 171. The joint strength can be further increased.

Further, the non-constraining portion 320 is a low-rigidity body having a lower rigidity than the shaft 190, and in the pressing step, the plastically deformed second adjacent portion 1522 presses the first yoke 171 to press the non-constraining portion 320. To transform.

According to this, since the non-restraint portion 320 is a low-rigidity body having a lower rigidity than the shaft 190, the plastically deformed second adjacent portion 1522 presses the first yoke 171 during the pressing step, so that the first yoke 171 is not pressed. The restraint portion 320 is deformed. As a result, the non-restraint portion 320 is also compressed, so that the distance between the first yoke 171 and the restraint portion 310 is narrowed. Therefore, the first adjacent portion 1521 and the second adjacent portion 1522 are compressed and further expand in the radial direction. Therefore, the area of the first adjacent portion 1521 and the second adjacent portion 1522 to be crimped to the first yoke 171 is increased, and the bonding strength to the first yoke 171 is further increased.

Further, in the state before the pressing process, the shaft 190 has a non-circular cross-sectional shape, and is uniform as a whole in the axial direction of the shaft 190.

Here, as compared with a shaft having a circular cross-sectional shape, a non-circular shaft is difficult to join by welding or caulking, and there is a problem that it is difficult to increase the joining strength to the yoke. However, even if the shaft 190 has a non-circular cross-sectional shape, the joining strength can be increased by joining the shaft 190 with the first yoke 171 by the manufacturing method described above.

Further, since the shaft 190 has a uniform cross-sectional shape as a whole in the axial direction, the first yoke 171 can be suitably joined to the shaft 190 formed by, for example, drawing.

The cross-sectional shape of the shaft 190 is a cross shape.

According to this, when the shaft 190 has a cross-shaped cross section, it is more difficult to join by welding or caulking, and it is difficult to further increase the joining strength to the yoke. However, even if the cross-sectional shape of the shaft 190 is cross-shaped, the joining strength can be increased by joining the shaft 190 with the first yoke 171 by the manufacturing method described above.

Further, the link mechanism 200 according to the present embodiment includes an inner shaft 150 (a shaft and a first yoke 171 joined to the inner shaft 150, and the inner shaft 150 has a main body portion 151 and a main body portion 151. It has a one end portion 152 to which the first yoke 171 is continuously joined, and the first yoke 171 in the one end portion 152 of the inner shaft 150 is adjacent to the facing region 1523 facing the first yoke 171 on the main body 151 side. (Ii) The adjacent portion 1522 protrudes outward in a state of being compressed in the axial direction.

According to this, since the second adjacent portion 1522 of the inner shaft 150 protrudes outward in a state of being compressed in the axial direction, the first adjacent portion 1521 is on the main body portion 151 side of the first yoke 171. It will be crimped to the surface (back surface). As a result, the joint strength between the inner shaft 150 and the first yoke 171 by caulking can be increased.

Further, the second adjacent portion 1522, which is adjacent to the facing region 1523 at one end portion 152 of the inner shaft 150 on the side opposite to the main body portion 151, protrudes outward over the entire circumference in a state of being compressed in the axial direction, and the second The first yoke 171 is sandwiched together with the adjacent portion 1521.

According to this, since the first adjacent portion 1521 and the second adjacent portion 1522 are crimped to the first yoke 171 by sandwiching the first yoke 171, the inner shaft 150 and the first yoke 171 It is possible to further increase the joint strength by caulking with.

Further, the cross-sectional shape of the inner shaft 150 is non-circular, and the inner shaft 150 has a uniform cross-sectional shape as a whole in the axial direction of the inner shaft 150 except for the first adjacent portion 1521 and the second adjacent portion 1522. The shape.

Here, as compared with a shaft having a circular cross-sectional shape, a non-circular shaft is difficult to join by welding or caulking, and there is a problem that it is difficult to increase the joining strength to the yoke. However, even if the cross-sectional shape is a non-circular inner shaft 150, the joining strength can be increased by joining the first yoke 171 by forming the first adjacent portion 1521.

The cross-sectional shape of the inner shaft 150 is a cross shape.

According to this, when the cross-sectional shape is the cross-shaped inner shaft 150, it is more difficult to join by welding or caulking, and it is difficult to further increase the joining strength to the yoke. However, even if the cross-sectional shape is a cross-shaped shaft 190, it is possible to increase the joining strength by joining the shaft 190 with the first yoke 171 by forming the first adjacent portion 1521.

Although the link mechanism 200 and the manufacturing method thereof according to the present invention have been described above based on the above-described embodiment, the present invention is not limited to the above-described embodiment. In the following description, in the same parts as those in the above embodiment, the same reference numerals may be given and the description thereof may be omitted.

(Modification example 1)
For example, in the above embodiment, the case where the non-restraint portion 320 is a low-rigidity body has been illustrated. However, the non-restraint portion may have the same rigidity as the restraint portion. Specifically, the non-restraint portion and the restraint portion may be integrally molded with, for example, metal. Even with such a jig 300A, it is possible to carry out the pressing step.

FIG. 7 is an explanatory diagram showing a state transition of the shaft 190 in the pressing process using the jig 300A according to the first modification. Specifically, FIG. 7A shows the state of one end 192 of the shaft 190 immediately after the start of pressing. FIG. 7B shows the state of one end portion 192 during pressing.

As shown in FIG. 7, in the jig 300A, the restraint portion 310a and the non-restraint portion 320a are integrally formed of metal or the like.

In the pressing step, the operator operates the press to press one end surface of the shaft 190 with the punch 400 of the press (see FIG. 7A). As the pressing by the punch 400 progresses, as shown in FIG. 7B, the main body portion 191 of the shaft 190 is constrained by the restraining portion 310a, so that although it is compressed in the X-axis direction, it expands in the radial direction. Absent. At one end 192, the opposing region 1523 is also constrained by the base 172 of the first yoke 171 so that it does not bulge in the radial direction. On the other hand, since the outer peripheral surfaces of the first adjacent portion 1521 and the second adjacent portion 1522 of the one end portion 192 are not constrained, they are plastically deformed and swell in the radial direction while being crushed in the X-axis direction. That is, the first adjacent portion 1521 and the second adjacent portion 1522 are plastically deformed so as to project outward over the entire circumference. Therefore, the first adjacent portion 1521 and the second adjacent portion 1522 are respectively crimped to the base portion 172 of the first yoke 171.

(Modification 2)
Further, in the above embodiment, the case where the non-restraint portion 320 is formed in an annular shape is illustrated. However, the non-restraining portion may have any shape as long as it surrounds the shaft 190 with a gap over the entire circumference. For example, the unconstrained portion may be a polygonal ring, an elliptical ring, or an oval ring.

FIG. 8 is a cross-sectional view showing a schematic configuration of the unconstrained portion according to the modified example 2. FIG. 8 is a diagram corresponding to FIG. 5B. As shown in FIG. 8, the unrestrained portion 320b may be intermittently surrounded with a gap over the entire circumference of the shaft 190. The non-constraining portion 320b shown in FIG. 8 is composed of, for example, three columnar members 322b, but the number of members 322b may be four or more. Further, the shape of the member 322b may be any shape. Further, the non-restraint portion may be arranged so that the first adjacent portion has a gap at least in a part in the circumferential direction. In this case, only a part of the first adjacent portion in the circumferential direction may be projected in the pressing process.

(Other)
Further, in the above embodiment, the inner shaft is illustrated as an example of the shaft, but the outer shaft and the like can be mentioned as another example of the shaft. That is, in the above embodiment, the case where the manufacturing method according to the present invention is applied to the shaft 190 which is the inner shaft 150 is illustrated, but the manufacturing method according to the present invention is applied to the shaft which is the outer shaft 140. You may.

In addition, it is realized by arbitrarily combining the components and functions in the embodiment and the modification without departing from the spirit of the present invention and the embodiment obtained by subjecting various modifications to the embodiment. The form is also included in the present invention.

The present invention is applicable to a link mechanism comprising a shaft and a yoke joined by caulking.

10 ... Steering device 11 ... Steering wheel 12 ... Steering shaft 13 ... Pinion shaft 14 ... Rack shaft 15 ... Steering wheel 16 ... Steering mechanism 17 ... First universal joint 18 ... Second universal joint 100 ... Intermediate shaft 110 ... Intermediate shaft 140 ... Outer shaft 141 ... Through hole 150 ... Inner shaft (shaft) 151 ... Main body 152 ... One end 171 ... First yoke (yoke) 172 ... Base 173 ... Arm 174 ... Through hole 181 ... First yoke 190 ... Shaft 191 ... Main body 192 ... One end 200 ... Link mechanism 300, 300A ... Jigs 310, 310a ... Restraint 311 ... Insertion holes 320, 320a, 320b ... Non-restraint 322b ... Member 400 ... Punch 1521 ... First adjacent part 1522 ... Second adjacent portion 1523 ... Opposing area

Claims (11)

A method for manufacturing a link mechanism including the shaft and the yoke, in which a yoke is assembled to a shaft held by a jig at the time of assembly.
The shaft has a main body portion and one end portion continuous with the main body portion and to which the yoke is joined.
The jig is
The first adjacent portion adjacent to the main body side is arranged with a gap at least in a part in the circumferential direction with respect to the facing region of the one end portion of the shaft with which the yoke faces, and the yoke. With the non-restraint part that supports
It is arranged at a position continuous with the non-restraint portion, and has a restraint portion that surrounds the main body portion of the shaft without a gap over the entire circumference.
The method for manufacturing the link mechanism is as follows.
By arranging the shaft at a position surrounded by the restrained portion and the non-restrained portion of the jig and supporting the yoke by the non-restrained portion, the yoke is provided to the one end portion of the shaft. The alignment process to align and
A method for manufacturing a link mechanism, which comprises, after the arrangement step, a pressing step of pressing one end surface of the shaft to plastically deform the first adjacent portion of the shaft and project it outward. The non-restraint portion surrounds the first adjacent portion with a gap over the entire circumference.
The method for manufacturing a link mechanism according to claim 1, wherein in the pressing step, the first adjacent portion of the shaft is plastically deformed by pressing one end surface of the shaft to project outward over the entire circumference. The second adjacent portion, which is adjacent to the opposite region of the one end portion of the shaft on the opposite side of the main body portion, is open over the entire circumference.
In the pressing step, by pressing one end surface of the shaft, each of the first adjacent portion and the second adjacent portion of the shaft is plastically deformed to be projected outward over the entire circumference, and the protruding said portion. The method for manufacturing a link mechanism according to claim 2, wherein the yoke is sandwiched between the first adjacent portion and the second adjacent portion. The non-restraint portion is a low-rigidity body having a lower rigidity than the shaft.
The method for manufacturing a link mechanism according to claim 3, wherein in the pressing step, the plastically deformed second adjacent portion deforms the unconstrained portion by pressing the yoke. The link according to any one of claims 1 to 4, wherein the shaft has a non-circular cross-sectional shape in the state before the pressing step and is uniform as a whole in the axial direction of the shaft. How to manufacture the mechanism. The method for manufacturing a link mechanism according to claim 5, wherein the cross-sectional shape of the shaft is a cross shape. With the shaft
With a yoke joined to the shaft
The shaft has a main body portion and one end portion continuous with the main body portion and to which the yoke is joined.
A link mechanism in which the first adjacent portion adjacent to the main body side of the one end portion of the shaft facing the yoke is projected outward in a state of being compressed in the axial direction. The link mechanism according to claim 7, wherein the first adjacent portion projects outward over the entire circumference. The second adjacent portion adjacent to the facing region at the one end portion of the shaft on the opposite side of the main body portion projects outward over the entire circumference in a state of being compressed in the axial direction, and the first adjacent portion The link mechanism according to claim 7 or 8, wherein the yoke is sandwiched with the yoke. The cross-sectional shape of the shaft is non-circular and
The link mechanism according to claim 9, wherein the shaft has a uniform cross-sectional shape as a whole in the axial direction of the shaft except for the first adjacent portion and the second adjacent portion. The link mechanism according to claim 10, wherein the cross-sectional shape of the shaft is a cross shape.

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