JP2014161881A - Joining structure of two members, joining method of two members and inter-yoke joining structure foe constituting shaft part and joint part of steering shaft of automobile using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining structure for doubly maintaining joining strength in a first member and a second member.SOLUTION: A joining structure 10 of two members is a structure for joining a first member 11 and a second member 12, and a frictional pressure contact surface F1 is formed on an end surface of the first member 11, and an end surface of the second member 12 is provided with a frictional pressure contact surface F2 frictionally brought into pressure contact with the frictional pressure contact surface F1 of the first member 11, and a wall part 12A is provided on the first member 11 side of the frictional pressure contact surface F2 of the second member 12, and an outer peripheral part of the first member 11 and the tip of the wall part 12A of the second member 12 frictionally brought into pressure contact with each other, are joined by welding W.

Description

  The present invention relates to a joining structure of two members, and more specifically, when a force in a torsional direction, a force in a tension or compression direction acts, or a force in a bending direction acts at a joint portion between two members. In particular, the present invention relates to a two-member joining structure suitable for joining, for example, a shaft portion of a steering shaft of an automobile and a yoke portion constituting a joint portion in which a force in a twisting direction acts.

As means for joining and connecting the first member and the second member, a connection structure by arc welding such as MIG welding is known.
Welding is performed with a known appropriate joint structure at the joint between the first member and the second member by this welding joint. For example, there is a form in which the ends of two members to be joined are brought into contact with each other and the periphery of the part is welded all around.

Further, friction welding is known as another technique for joining two members together (see, for example, Patent Documents 1 and 2).
In the protective fence support disclosed in Patent Document 1, when the support is fixed to the pedestal fixed to the side of the roadway via the joint member, the cylindrical joint member and the flat portion of the pedestal are joined by friction welding. It has been configured.
Patent Document 2 discloses an example in which a hollow connecting rod and a cylindrical end member are joined by friction welding.

By the way, in the friction welding, for example, one member is fixed and the other member is rotated or slid at a high speed with a predetermined pressure (friction pressure) applied to the other member. This is a method of joining two members by further applying pressure when both members are softened by frictional heat generated in the above.
In the friction welding, the entire bonding surfaces are simultaneously bonded by the frictional heat between the surfaces to be bonded. Furthermore, since friction welding does not sequentially advance the joining in a linear manner with respect to the joining portion like the MIG welding or TIG, the joining is completed in a short time.
For this reason, in recent years, it has been used in a wide range of fields.

JP 2011-1694 A Japanese Patent Laid-Open No. 11-156562

  As described above, according to the friction welding method, it is a joining method that can be joined in a short time and has a high work efficiency, but the present invention aims to further improve the soundness of the joint, and performs the joining twice. is there.

  For example, in the case of joining between the shaft part of the steering shaft of the automobile as the first member and the yoke forming the universal joint part as the second member by friction welding or welding, there is some joint failure at this joint. There is a need for a device that can maintain the bonding strength even when the occurrence of the occurrence of the sag.

The present invention is intended to improve the above-described problems, and in particular, to provide a joint structure that maintains the joint strength of the first member and the second member disposed on the same axis. The two members are made into a first joint by friction welding, and the two members are further joined by a welding method by welding to perform double joining. It is what makes a joined part more reliable.
The present invention can be optimally used for joining the shaft portion of the steering shaft and the yoke portion forming the universal joint portion. However, the invention can be applied to a structure capable of friction welding even in the joint portion of other two members. Provide a possible structure.
Note that the first member can be a member having a hollow portion or a solid material in which the hollow portion is not formed. The same applies to the second member.
Furthermore, it does not specify whether or not burrs are discharged during friction welding, and how to discharge burrs.
Although welding is used for the second joining of the present invention, the first joining has already been completed at the second joining time, and the joining of the first member and the second member has been completed. Welding can be performed easily.

In order to achieve the above object, the two-member joint structure of the present invention is a joint structure of a first member and a second member,
A friction welding surface is formed on an end surface of the first member;
The end surface of the second member includes a friction welding surface that is friction-welded with the friction welding surface of the first member, and
On the first member side of the second member, a wall portion that faces the outer peripheral surface of the first member at the end of friction welding is provided.
The outer peripheral portion of the first member that is friction-welded as the first joint and the wall portion of the second member are joined by welding as the second joint.

The steering shaft according to the present invention includes a shaft portion coupled to a steering wheel and a joint portion, and a joining structure for joining both of the two members according to any one of claims 1 to 7. A steering shaft using a joining structure,
The first member is a shaft portion of the steering shaft, and the second member is a yoke constituting the joint portion.

Further, the two-member joining method of the present invention is a joining method of the first member and the second member, and a friction welding surface is formed on an end surface of the first member and the second member. A friction welding surface that is friction-welded with the friction welding surface is formed on the end face of
The first member and the second member prepared in advance are provided with a wall portion facing the outer peripheral surface of the first member after friction welding on the first member side of the second member. Process,
A second step of friction welding the friction welding surfaces of the first member and the friction welding surfaces of the second member;
The first member and the second member include a third step of joining the outer peripheral surface of the first member and the wall portion of the second member by welding.

  Since the present invention is configured as described above, after the end surface of the first member and the end surface of the second member are friction-welded, the end of the wall of the second member and the first end The outer peripheral surface of the member is joined by welding. As a result of the two members consisting of the first member and the second member being subjected to double bonding, more reliable bonding is achieved and double bonding strength is maintained.

FIG. 2 is an exploded view showing a first embodiment of a two-member joining structure according to the present invention, and showing a stage before joining the first member and the second member, wherein the first member is partly an inner spline. This is the case of the type having The whole side view of the partial cross section which shows the state which inserted the 1st member from the state shown in FIG. 1 in the wall part formed in the cylindrical shape of the 2nd member, and the both members were friction-welded which is 1st joining. It is. FIG. 3 is an overall side view of a partial cross-section showing a state in which the outer periphery of the tip of the wall portion of the second member and the first member are joined by full circumference welding as the second joining from the state of FIG. 2. FIG. 4 is a longitudinal sectional view taken along line IV-IV in FIG. 3, and FIG. 4A is a state before the outer circumference of the wall tip of the second member and the first member are welded all around, FIG. ) Is a diagram showing a state after the outer periphery of the wall tip and the first member are welded all around. FIG. 7 is an exploded view showing a second embodiment of the two-member joining structure according to the present invention, and showing a stage before joining the first member and the second member, where the first member is solid and partially This is a type having an outer spline. It is the whole side view of the partial cross section which shows the state which inserted the 1st member from the state shown in FIG. 5 in the wall part formed in the cylindrical shape of the 2nd member, and friction-welded both members. FIG. 7 is an overall side view of a partial cross section showing a state in which the tip of the cylindrical wall portion of the second member and the outer periphery of the first member are joined together by welding all around from the state of FIG. 6. It is a fragmentary sectional view showing a 7th embodiment which shows other examples of a friction welding part which is the 1st junction in each embodiment. It is a fragmentary sectional view showing an 8th embodiment which shows other examples of friction welding which is the 1st junction in each embodiment. It is a perspective view which shows the 2nd member of the example which made the shape of the wall part in each embodiment non-cylindrical. It is a side view which shows the example which welded which is 2nd joining using the 2nd member of FIG. 1 is an overall perspective view showing an example in which a joining structure of two members according to the present invention is applied to a steering shaft of a steering device. It is a side view which shows the detail of the steering shaft of FIG. It is a side view which shows the example which applied the joining structure of the 2 member which concerns on this invention to rotational force transmission apparatuses, such as a propeller shaft.

[Description of configuration]
Below, with reference to FIGS. 1-4, 1st Embodiment of the joining structure of the 2 member which concerns on this invention is described in detail.

FIG. 1 is an exploded view showing a stage before a first member 11 and a second member 12 constituting a two-member joint structure (hereinafter simply referred to as a joint structure) 10 of the first embodiment are joined. .
In FIG. 1, reference numeral F <b> 1 is a friction welding surface formed on the end face of the first member, and reference numeral F <b> 2 is a friction welding surface formed on the second member 12, facing the friction welding surface on the first member side. It is formed as follows.
Reference numeral 12A denotes a wall portion which is formed so as to face the outer peripheral surface of the first member 11 after the friction welding surfaces F1 and F2 are friction-welded. In this embodiment, the wall 12A is formed in a cylindrical shape. Yes.
This wall portion is formed for the purpose of performing the second joining, and is not necessarily cylindrical, and it is sufficient if it is formed only in a portion necessary for welding, which is the second joining.
FIG. 2 shows that the first member 11 is inserted into the cylindrical wall portion 12A facing the first member side of the second member 12 from the state shown in FIG. It is a figure which shows the state which carried out the friction welding which is joining.
FIG. 3 shows that the first member 11 and the second member 12 are welded all around the tip of the cylindrical wall portion 12A of the second member 12 and the outer periphery of the first member 11 from the state of FIG. It is a figure which shows the state which carried out 2nd joining. In FIG. 4, the symbol B is a burr.

  As shown in FIGS. 1 to 4, the joining structure 10 of the first embodiment is a structure in which the first member 11 and the second member 12 arranged on the same axis line are joined twice. is there.

That is, the first member 11 and the second member 12 are double-bonded, that is, a joint by the friction welding joint means F as the first joint means and a joint by welding W as the second joint means. It is joined.
Each of the first member 11 and the second member 12 is made of, for example, aluminum or an aluminum alloy.

The first member 11 is formed in a pipe shape.
A cylindrical wall portion 12A is formed at the tip of the second member 12 on the first member 11 side.
And the clearance gap between the inner peripheral surface of this wall part 12A and the outer peripheral surface of the 1st member 11 becomes the burr accommodating space | gap 12B which accommodates the burr | flash B produced by the said friction welding as shown in FIG. Yes.
Further, on the side opposite to the wall portion 12A of the second member 12, a burr accommodating hole 12C continuing to the wall portion 12A is formed inside the second member 12.

  It should be noted that the burr accommodating gap 12B or burr accommodating hole 12C may be formed as necessary. When the friction welding surfaces F1 and F2 softened by friction welding are bonded by pressure bonding so as not to generate burr, the burr accommodating gap 12B or The burr accommodating hole 12D is not necessary.

In the first member 11, the end surface on the second member 12 side is formed with a friction welding surface F1. On the other hand, a friction welding surface F2 that is in friction welding with the friction welding surface F1 is formed on the side surface of the friction welding surface F1 of the second member 12.
The cylindrical wall 12A is rotated or frictionally heated so that the first member and the second member can be frictionally heated for friction welding by forming the burr accommodating gap 12B. A gap capable of sliding or vibrating is formed between the outer peripheral surface of the first member.
The friction welding surface F2 is a ring-shaped flat surface formed between the inner diameter dimension of the wall portion 12A and the outer diameter of the through hole 12C for accommodating burrs on the inner surface of the wall portion 12A. It has become.

  As described above, the friction welding unit F joins the friction welding surface F1 of the first member 11 and the friction welding surface F2 formed on the second member 12 by friction welding, It is means for joining the first member 11 and the second member 12.

Here, as described above, the friction welding is performed by fixing one of the two members, that is, the first member 11 and the second member 12, for example, the second member 12. When a predetermined friction pressure is applied to the member 11, the member 11 is rotated or slid at a high speed, and when the members 11 and 12 are softened by the frictional heat generated at that time, further pressure (upset pressure) is applied. In this method, the first member 11 and the second member 12 are joined.
And since friction welding is what is joined by the frictional heat of the surfaces to be joined, the entire joining surfaces are joined simultaneously.

As shown in FIGS. 3 and 4, the first member 11 and the second member 12 in which the respective end surfaces are friction-welded are not only friction-welded but also the wall portion 12 </ b> A of the second member 12. The tip and the outer peripheral surface of the first member 11 are joined by welding.
In this embodiment, the welding is the all-around welding W by MIG welding, but this welding may be partial welding such as intermittent welding.
In addition, as a welding method, MIG, TIG, and other fusion welding methods can be used. In this welding, since the first member 11 and the second member 12 are already joined by friction welding, welding is easy.

  As described above, the first member 11 and the second member 12 are joined by friction welding and double joining by welding W, so that the joint is more reliably joined.

Next, the joining method (procedure) of the 1st member 11 and the 2nd member 12 is demonstrated.
First, as a first step, as shown in FIG. 1, a first member 11 and a second member 12 are prepared in advance. At this time, a friction welding surface F1 is formed on the end surface of the first member 11, and a friction welding surface F2 is formed on the end surface of the second member 12 so as to be friction-welded with the friction welding surface F1. ing.
A cylindrical wall portion 12A is formed at the tip of the second member 12 on the first member 11 side, and there is friction between the inner peripheral surface of the wall portion 12A and the outer peripheral surface of the first member 11. A burr accommodating gap 12B is formed to accommodate the burr B generated by the pressure contact.

  Next, as a second step, as shown in FIG. 2, the friction welding surface F <b> 1 of the first member 11 and the friction welding surface F <b> 2 of the second member 12 are friction welded to perform the first joining, The member 11 and the second member 12 are subjected to friction welding F which is a first joint.

Furthermore, as the third step, the first member 11 and the second member 12 are joined together, and the tip of the wall portion 12A of the second member and the outer peripheral surface of the first member 11 are joined together as a second joint. Thus, joining is performed by all-around welding W which is the second joining.
As a result, the first member 11 and the second member 12 are double-bonded by friction welding and all-around welding W.

According to the joining structure 10 having the above configuration, the following effects can be obtained.
(1) A friction welding surface F1 formed on the end surface of the first member 11 and a friction welding surface F2 formed at a position facing the friction welding surface F1 on the first member side of the second member 12. After the friction welding as the first joining means, the tip of the wall portion 12B of the second member 12 and the outer peripheral surface of the first member 11 are joined by the all-around welding W as the second joining means. As a result, the two members made up of the first member 11 and the second member 12 are subjected to double bonding, resulting in more reliable bonding and maintaining the bonding strength.

(2) Since the first member 11 and the second member 12 are joined by the double joining of the friction welding and the weld W, a failure occurs in any joining due to a joining failure or some cause. However, complete destruction will not occur, and as a result, unforeseen circumstances can be avoided.

(3) Since the first member 11 and the second member 12 are joined by the double joining of the friction welding and the welding W, the rotational load applied to any one of the members is applied to the two members 11. , 12 are in a shared state, and the burden on each of the members 11, 12 can be reduced. As a result, the lifetime of the first member 11 and the second member 12 can be extended.

  Next, a second embodiment of the two-member joint structure according to the present invention will be described in detail with reference to FIGS.

  FIG. 5 is an exploded view showing a stage before joining the first member 21 and the second member 22 constituting the joining structure 20 of the second embodiment. FIG. 6 shows that the friction welding surface F1 of the first member 21 is brought into contact with the friction welding surface F2 of the second member 22 from the state shown in FIG. It is a figure which shows the state which pressure-contacted. FIG. 7 is a diagram illustrating a state in which the tip of the wall portion 22A of the second member 22 and the outer peripheral surface of the first member 21 are joined by the entire circumference welding W that is the second joining from the state of FIG. is there.

  Here, the bonding structure 20 of the second embodiment is different from the bonding structure 10 of the first embodiment in that the first member 11 in the bonding structure 10 of the first embodiment is configured by a pipe-shaped member. The point is that the first member 21 in the joint structure 20 of the second embodiment is formed of a round bar-like solid member.

As shown in FIGS. 5 to 7, the joint structure 20 of the second embodiment is similar to the joint structure 10 of the first embodiment in that the first member 21 disposed on the same axis and the second member 21 are arranged on the same axis. In this structure, the member 22 is double joined.
In other words, the first member 11 and the second member 12 are joined by double joining of joining by the friction welding joint means F as the first joining means and joining by welding as the second joining means. It is what.

The first member 21 has an outer peripheral surface formed in a circular cross-section, and the outer peripheral surface of the first member 21 is on the opposite end side of the second member 22 along the axial direction of the first member 21. The outer spline 21A is formed over a predetermined range.
The second member 22 is formed in substantially the same shape as the second member 12 of the first embodiment, and a cylindrical shape is formed on the inner diameter of the distal end of the second member 22 on the first member 21 side. A wall portion 22A is formed.

  And the clearance gap between the inner peripheral surface of this wall part 22A and the outer peripheral surface of the 1st member 21 becomes the burr | flash accommodating space | gap 22B which accommodates the burr | flash B produced by the said friction welding as shown in FIG. Yes. Further, on the side opposite to the wall portion 22A of the second member 22, a burr accommodating hole 22C continuing to the wall portion 22A is formed inside the second member 22.

The end surface of the first member 21 on the second member 22 side is formed on the friction welding surface F1. On the other hand, a friction welding surface F2 that is friction-welded to the friction welding surface F1 is formed on the back surface of the wall portion 22A at the end surface of the second member 22 on the first member 21 side. .
The friction welding surface F2 is a ring-shaped flat surface formed between the inner diameter dimension of the wall portion 22A and the outer diameter of the burr accommodating hole 22C on the inner surface of the wall portion 22A. Yes.
The first friction welding surface F1 and the second friction welding surface F2 are friction welded, and this friction welding constitutes a first joining means.

  As shown in FIGS. 6 and 7, the first member 21 and the second member 22 in which the respective friction welding surfaces F1 and F2 are friction-welded are further provided with the second member 22 in addition to the friction welding. As described above, the tip of the cylindrical wall portion 22A and the outer peripheral surface of the first member 21 are joined by the all-around welding W by the MIG welding as the second joining means.

As described above, the first member 21 and the second member 22 include the friction welding F of the friction welding surfaces F1 and F2, the tip of the cylindrical wall portion 22A of the second member 22, and the first member 21. This is a double joining of the outer peripheral surface of the member 21 by the all-around welding W, and the joined portion is joined more reliably.
Note that the first member 11 and the second member 12 are made of, for example, aluminum or an aluminum alloy.

Next, the joining method (procedure) of the 1st member 21 and the 2nd member 22 is demonstrated.
First, as a first step, as shown in FIG. 5, a first member 21 and a second member 22 are prepared in advance. At this time, a friction welding surface F1 is formed on the end surface of the first member 21, and a friction welding surface F2 is formed on the end surface of the second member 22 so as to be friction-welded with the friction welding surface F1. .
A cylindrical wall portion 22A is formed at the tip of the second member 22 on the first member 21 side. Between the inner peripheral surface of the wall portion 22A and the outer peripheral surface of the first member 21. Is formed with a burr accommodating gap 22B for accommodating a burr B generated by friction welding.

  Next, as a second step, as shown in FIG. 6, first welding is performed by friction welding the friction welding surface F <b> 1 of the first member 21 and the friction welding surface F <b> 2 of the second member 22, The first member 21 and the second member 21 are subjected to friction welding F which is a first joint.

Further, as a third step, as shown in FIG. 7, the first member 21 and the second member 22 are connected to the tip of the cylindrical wall portion 22 </ b> A of the second member 22 and the first member 21. The outer peripheral surface is joined by MIG welding, which is a second joint, all-around welding W.
As a result, the first member 21 and the second member 22 are double joined by friction welding and joining by all-around welding W.

  According to the second embodiment configured as described above, it is possible to obtain substantially the same effects as the above (1) to (3).

Next, based on FIG. 8, 3rd Embodiment of the joining structure of the 2 member which concerns on this invention is described in detail.
FIG. 8 shows a third embodiment showing a modified example of the friction welding which is the first joining of the first member and the second member constituting the two-member joining structure 30 of the third embodiment. 1 is a cross-sectional view of a state in which friction welding is performed, which includes a first member 31 and a second member 32. FIG.

At the distal end portion of the first member 31, a friction welding surface F1 of the first member is formed, and a burr storage cavity 31D is formed.
A friction welding surface F2 is formed on the first member 31 side of the second member 32. In FIG. 8, reference numeral 32 </ b> A is a wall portion for performing the second bonding, and this wall portion 32 </ b> A is formed in a cylindrical shape so as to face the outer surface of the first member 31 after the friction welding. Has been.
Although the wall portion 32A is formed in a cylindrical shape in this embodiment, it can be partially formed because it is provided for the second joining.

  In the present embodiment, the wall portion 32 </ b> A has a cylindrical shape, and no gap for accommodating burr is formed between the outer surface of the member 31 of the first member, but the first member 31 and the second member 32 are not formed. Naturally, a gap capable of movement such as rotation necessary for friction welding is necessary.

The difference between each embodiment in the present embodiment is that a gap is not formed for burr accommodation between the cylindrical wall portion 32A and the outer surface of the first member 31, and the second member 32. The burr accommodating hole 31D is provided on the first member 31 side, and the generated burr is accommodated in the burr accommodating cavity 31D.
The tip of the wall portion 32A and the outer surface of the first member 31 are second joined by welding W.

According to the joining structure 30 of the third embodiment configured as described above, the following effects can be obtained in addition to the effects substantially the same as the above (1) to (3).
(4) Even if a burr accommodating space is not formed between the wall portion 32A at the front end of the second member 32 and the outer surface of the first member 31, a burr accommodating cavity is formed at the front end of the first member 31. 31D is formed, and burrs generated by friction welding can be accommodated in the burrs accommodating cavity 31D.

Next, based on FIG. 9, 4th Embodiment of the joining structure of the 2 member which concerns on this invention is described in detail.
FIG. 9 shows a modification of the friction welding that is the first joint between the first member and the second member constituting the two-member joint structure 40 of the fourth embodiment, and the friction that is the first joint. It is sectional drawing of the state after press-contact, and consists of the 1st member 41 and the 2nd member.

A friction pressure contact surface F1 of the first member 41 is formed on the entire front end portion of the first member 41.
Further, a friction welding surface F2 is formed on the second member 42 on the first member 41 side. In FIG. 9, reference numeral 42 </ b> A is a wall portion for performing the second joining, and the wall portion 42 </ b> A is formed to face the outer surface of the first member 41 after the friction welding.

  Although the wall portion 42A is formed in a cylindrical shape in this embodiment, it is sufficient to form it partially because it is provided for the second joining.

  In the present embodiment, the wall portion 42A has a cylindrical shape, and no gap for accommodating burr is formed between the outer surface of the first member, but the first member 41 and the second member 42 are not formed. There is a gap that can move, such as rotation, necessary for friction welding.

  The difference from each of the embodiments in this example is that a gap is not formed for burr accommodation between the cylindrical wall portion 42A and the outer surface of the first member 41, and the burr accommodation of the second member. The burr storage cavity is not provided on the hole or the first member side.

At the time of friction welding, friction pressure is applied to the first member 41 and the second member 42, and the friction welding surfaces of both members 41, 42 are heated and softened by friction rotation (sliding). The pressure is applied by applying an upset pressure.
In each of the embodiments described above, the oxide on the friction surface is discharged by discharging the burrs. However, in the present embodiment, it can be used when the burrs need not be discharged. That is, it can be used when the surface oxide is reduced as much as possible or the presence of the oxide does not hinder.
And the 2nd joining W is made by welding with the front-end | tip of wall part 42A, and the outer surface of the 1st member 41. As shown in FIG.

According to the junction structure 40 of the fourth embodiment configured as described above, the following effects are obtained in addition to the effects substantially the same as the above (1) to (3).
(5) It can be used when burr discharge is not required, that is, when the oxide on the surface is reduced as much as possible or the presence of oxide does not hinder.

Next, a fifth embodiment of the two-member joint structure according to the present invention will be described in detail with reference to FIGS.
FIG. 10 is a perspective view of the second member 52.
FIG. 11 shows a modified example of the welded portion that is the second joint between the first member 51 and the second member 52 constituting the two-member joint structure 50 of the fifth embodiment. It is a side view of a state after a certain MIG welding, and consists of a first member 51 and a second member 52.

In FIGS. 10 and 11, reference numeral 52 </ b> A is a wall portion. Unlike the above-described embodiments, the wall portion 52 </ b> A is not formed in a cylindrical shape but is formed by two portions 52 </ b> A <b> 1 and 52 </ b> A <b> 2.
FIG. 11 shows the friction welding F, which is the first joining of the first member 51 and the second member 52, between the friction welding surface F1 of the first member 51 and the friction welding surface F2 of the second member 52. The state where welding by MIG welding which is the first joint is performed between the wall portion 52A and the outer surface of the first member 51 is shown.

As shown in FIG. 11, welding W1 is applied to the front end of the wall 52A1 and the outer surface of the first member 51, and welding W2 is applied to the side end of the wall 52A1 and the outer surface of the first member 51. ing.
Similar welding W1 and W2 are also applied to the wall 52A2.

  These welds W1 and W2 only need to obtain a required joint strength, and if necessary, only weld W1 or weld W2 can be used. In addition, according to the present embodiment, it is possible to increase the welding length as compared with the respective embodiments.

  In each of the above embodiments, the wall portion formed on the second member is formed in a cylindrical shape. However, the wall portion is not necessarily formed in a cylindrical shape and can be used for the second bonding. The position and shape of the second member can be arbitrarily designed as long as they can be integrated with or integrated with the second member and can maintain the strength necessary for the purpose of the second bonding. It is good also as what formed the wall part in.

  According to the joining structure 50 of the fifth embodiment configured as described above, substantially the same effects as the above (1) to (3) can be obtained.

  Next, an example in which the two-member joint structure 10 of the present invention is applied to a steering shaft 74 constituting a steering device 70 of an automobile will be described with reference to FIGS.

  As shown in FIG. 12, the steering device 70 includes a steering wheel (handle) 71, a steering column cover 72, a steering main shaft 73, a steering shaft 74, a steering gear box 75, a tie rod 76, links, and the like.

  The rotation of the steering wheel 71 is transmitted from the steering main shaft 73 to the steering gear box 75 via the steering shaft 74, and is decelerated by the steering gear in the steering gear box 75 to change the direction of motion, so that the left and right sides of the pitman arm It turns into movement in the direction.

  This movement is transmitted to the left and right tie rods 76, 76 via the relay rod, and the knuckle arm is swung in the left-right direction by the tie rods 76, 76. The steering knuckle (front bearing portion) is rotated so that the direction of the front wheel can be changed.

  The steering shaft 74 is provided between the steering main shaft 73 and the steering gear box 75. The steering shaft 74 includes a first joint portion 74A attached to the steering main shaft 73 side, an upper shaft 74B connected to the first joint portion 74A, a lower shaft 74C connected to the upper shaft 74B, The second joint 74D is connected to the lower shaft 74C and connected to the steering gear box 75.

  In the steering shaft 74, the first members 11, 21 and the like are the upper shaft 74B and the lower shaft 74C of the steering shaft 74, and the second members 12, 22 and the like are the first and second joints, respectively. This is a yoke for forming the portions 74A and 74D.

  The steering shaft 74 transmits the operating force of the steering wheel to the steering gear in the steering gear box 75, and is slidable in the axial direction in order to buffer an impact transmitted from the road surface to the handle 71.

That is, as shown by an arrow A in FIGS. 12 and 13, the inner peripheral portion of the upper shaft 74B and the outer peripheral portion of the lower shaft 74C are slidably engaged with each other, that is, in the arrow A direction.
Therefore, the upper shaft 74B and the lower shaft 74C are slidable with respect to each other and capable of transmitting a rotational force, for example, configured to be able to transmit rotation and slide in the axial direction by engagement of the inner spline and the outer spline. Yes.

In the present embodiment, the upper shaft 74B needs to be configured by a first member having an inner spline therein. For example, the first shaft of the first embodiment in which the inner spline 11A is formed. The member 11 is used, and the second members 12 and 22 of the first and second embodiments are used for the yokes 74A and 74D as joint portions.
Then, any one of the joining structures 10 and 20 of the first and second embodiments is applied to such joining of the upper shaft 74B and the yoke 74A.

Further, the lower shaft 74C needs to be configured by a first member having an outer spline on the outside thereof. For example, the first member 21 of the second embodiment is used, and the first shaft 21 constituting the yoke is used. The second member 12 of the first embodiment is used for the two joint portions 74D.
The joining structure 10 of the first embodiment is applied to joining the lower shaft 74B and the yoke 74D.
Further, the third to fourth embodiments can be used for the first bonding, and the fifth embodiment can be used for the second bonding.

According to the steering shaft 74 configured as described above, the following effects can be obtained.
(6) Since each of the joint structures 10, 20, 30, 40, 50 has the effects (1) to (3), the upper shaft 74B of the steering shaft 74, the first joint portion 74A, and Since the lower shaft 74C and the second joint portion 74D can be reliably joined, the function of the steering shaft 74 can be sufficiently achieved.

  Next, an example in which the joining structure 10 of the present invention is applied to a rotational force transmission device 80 such as a propeller shaft will be described with reference to FIG.

  As shown in FIG. 14, in the rotational force transmission device 80, a first connection member 82 is joined to one end of a shaft member 81 disposed on the same rotation shaft, and a second connection member 83 is joined to the other end. Rotation transmitting members 84 and 85 are coupled to the end portions of the first connecting member 82 and the second connecting member 83, respectively.

  The shaft member 81 includes the first members 11 and 21 of the two-member joining structures 10 and 20 of the first and second embodiments, and the first connecting member 82 and the second connecting member 83. However, it is comprised by the 2nd members 12 and 22 of either of the joining structures 10 and 20 of the said 1st, 2 embodiment.

That is, in the rotational force transmission device 80 having the above-described configuration, the first and second shaft members 81 are joined to the first connecting member 82 and the other end of the shaft member 81 to the second connecting member 83. One of the joining structures 10 and 20 of the embodiment, for example, a two-member joining structure 10 is applied.
However, in the rotational force transmission device 80, since the first connection member 82 and the second connection member 83 are joined to both ends of the shaft member 81, the shaft member 81 is connected to the first connection structure 10 of the first embodiment. It is not necessary to provide the inner spline 11A of the member 11 and the outer spline 21A of the second member 21 in the joint structure 20 of the second embodiment.
Further, the third to fourth embodiments can be used for the first bonding, and the fifth embodiment can be used for the second bonding.

According to the rotational force transmission device 80 configured as described above, the following effects can be obtained.
(7) Since each of the joint structures 10, 20, 30, 40, 50 has the effects (1) to (3), in the rotational force transmission device 80 such as a propeller shaft, the shaft member 81 and the first member Since the joining with the joining of the first connecting member 82 and the second connecting member 83 can be ensured, the function of the rotational force transmitting device 80 such as a propeller shaft can be sufficiently achieved.

  As described above, the present invention has been described with reference to the respective embodiments, but the present invention is not limited to the respective embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention. Further, the present invention includes a combination of part or all of the configurations of the above-described embodiments as appropriate.

For example, in each of the embodiments, as the second joining means, the tips of the wall portions 12A and 22A of the first and second members 12 and 22 and the outer periphery of the one end portion of the first and second members 11 and 21 are used. Although it was set as the structure which welds all the circumferences, it is not restricted to this. Partial welding that welds at a predetermined interval may be used.
Even if it does in this way, the effect substantially the same as said (1) can be acquired.

  Moreover, in each said embodiment, although the member to join joined the embodiment using the aluminum alloy material, as long as friction welding can be performed and welding is possible, another metal material may be sufficient, and the 1st member, 2nd These members may be made of different metal materials.

The present invention can be used when a force in the torsional direction acts, a force in the tension or compression direction acts, or a force in the bending direction acts at the joint between the two members.
For example, it can be used for joining between a shaft portion of a steering shaft of an automobile, for example, and a yoke portion constituting a joint portion where a force in a twisting direction acts.

10, 20, 30, 40, 50 Two-member joining structure (first to fifth embodiments)
11, 21, 31, 41, 51 First member 12, 22, 32, 42, 52 Second member 12A, 22A, 32A, 42A, 52A Wall portion 12B, 22B, 32B, 42B, 52B Burr accommodating gap 31D Burr accommodating cavity 70 Steering device 74 Steering shaft 80 Rotational force transmission device such as propeller shaft F Friction welding means F1 Friction welding surface of first member F2 Friction welding surface of second member B Burr W Welding

Claims (9)

A joining structure between the first member and the second member,
A friction welding surface is formed on an end surface of the first member;
The end surface of the second member is provided with a friction welding surface which is friction-welded with the friction welding surface of the first member, and the first member side of the second member is provided with the first member. A wall facing the outer peripheral surface of the
A two-member joining structure, wherein an outer peripheral portion of the first member and a wall portion of the second member which are friction-welded are joined by welding. The two-member joint structure according to claim 1,
The two-member joining structure, wherein the wall portion is formed in a cylindrical shape whose inner surface faces the outer peripheral portion of the first member. The two-member joint structure according to claim 1,
The two-member joining structure, wherein the welding is a partial welding applied to the distal end of the cylindrical wall and the outer peripheral surface of the first member. The two-member joint structure according to claim 1,
The two-member joining structure characterized in that the welding is a full-circumferential welding applied to the end of the cylindrical wall and the outer peripheral surface of the first member. The two-member joint structure according to claim 1,
The two-member joining structure, wherein the wall portion is formed by a plurality of wall portions whose inner surfaces face the outer peripheral portion of the first member. The two-member joint structure according to claim 1,
The wall portion is formed by a plurality of wall portions whose inner surfaces are opposed to the outer peripheral portion of the first member, and the second joint is formed by welding the tip and / or side of the first member and the side surface of the first member. A two-member joining structure characterized by The two-member joint structure according to claim 1,
A two-member joining structure characterized in that a cylindrical peripheral wall portion having a burr accommodating space for accommodating a burr generated by the friction welding is provided between the wall portion and the outer peripheral surface of the first member. . A steering shaft having a shaft portion and a joint portion connected to a handle and applying the joint structure of two members according to any one of claims 1 to 3,
The steering shaft, wherein the first member is a shaft portion of the steering shaft, and the second member is a yoke that forms the joint portion. A method for joining the first member and the second member,
A friction welding surface is formed on the end surface of the first member, and a friction welding surface is formed on the end surface of the second member.
A first step of preparing in advance the first member and the second member provided with a wall facing the outer peripheral surface of the first member on the first member side of the second member;
A second step of friction welding the friction welding surfaces of the first member and the friction welding surfaces of the second member;
The second member comprising the third step of joining the first member and the second member to each other by welding the outer peripheral surface of the first member and the wall portion of the second member. Joining method.

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