JP2003285169A - Method for connecting via frictional agitating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the necessity of post-works for removing a material corresponding to a volume of an axial member after connecting since a shearing strength can be improved when the member is retained at a connecting part but the material corresponding to the volume of the axial member overflows and hence the post-works for removing the material becomes necessary. <P>SOLUTION: A method for connecting via frictional agitating comprises the steps of: constituting a link arm 10 of a rod 11, a bracket 12 and a bush 13, engaging one end of the rod 11 with a forked part 15 provided at the bracket 12, inserting the axial member 20 into an initial insertion hole 25 formed at an inside of an enlarged part 17 of the forked part 15, moving the member 20 toward the connecting part 19 while rotating the member 20, and retaining the member 20 on the connecting part 19. Thus, the hole 25 absorbs the material corresponding to the volume of the member 20 due to mixture by agitating to prevent the material from overflowing. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a friction stir welding method. The friction stir welding method is a joining method in which the shaft-shaped member is rotated on the joint portion of the two joint members to stir and mix while plasticizing the joint portion of the both members to integrate them.

[0002]

2. Description of the Related Art Such a friction stir welding method is known, for example, the one described in Japanese Patent No. 2712838.
FIG. 7 shows this method, in which the ends of the first joining member 1 and the second joining member 2 made of a suitable metal are abutted against each other, and the shaft-like member 4 is rotated on the joining portion 3 to form both sides of the joining portion 3. The first joining member 1 and the second joining member 2 in FIG.

At this time, the shaft-shaped member 4 is supported at both ends in the axial direction by the rotating members 5 and 6, and the plasticized portion is pressed by the respective tips of the rotating members 5 and 6 to prevent scattering. The shaft member 4 is attached to the rotating member 5 side,
When the joining is completed, the shaft-shaped member 4 is separated from the rotating member 6 and is pulled up together with the rotating member 5.

Further, it is also known that the shaft-shaped member 4 is separated from the rotating member at the time of completion of joining and left on the joining portion 3 to be used as a reinforcing member for increasing the joining strength in the shearing direction (special feature. Wish 2000-233443
issue).

[0005]

In the above-mentioned conventional example, by supporting both ends of the shaft-shaped member 4 by the rotating members 5 and 6, both ends of the shaft-shaped member 4 are supported. Since it can be deeply inserted into and mixed with stirring, the joint strength can be increased.

However, in the case of the above-mentioned conventional example, since the shaft-shaped member 4 is pulled out at the time of completion of the joining, the pulling-out mark consisting of the hole or the concave portion corresponding to the volume reduction due to the pulling-out of the shaft-shaped member 4 remains, and the appearance of the joined portion May be damaged. Further, it cannot be expected to increase the shear strength at the joint by utilizing the remaining shaft-shaped member 4.

On the other hand, if the shaft-shaped member is left and embedded in the joint member, the shear strength at the joint can be increased by the shaft-shaped member 4. However, by leaving the shaft-shaped member 4 left, the plasticized portion of the joining member to be stirred and mixed overflows by the volume of the shaft-shaped member 4.
Since a post-processing for removing this overflow portion after the joining is completed, a lot of labor is required.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a friction stir welding method and a joined product thereof which can increase the shear strength of a joint portion and can omit post-processing after joining due to overflow of a plasticized material.

[0009]

In order to solve the above-mentioned problems, the friction stir welding method according to the first aspect of the present invention employs a method of joining to each other.
In a friction stir welding method in which a shaft-shaped member is rotated and joined at a joint portion of two joint members, an initial difference for inserting the shaft-like member in advance on either one side of the two joint members or on the joint portion. An insertion portion is formed in advance, and the shaft-shaped member is inserted into the initial insertion portion and moved while rotating to stir and mix the joint portion and leave the shaft-like member embedded and left on the joint portion. Is characterized by.

The friction stir welding method according to claim 2 is
In the above-mentioned claim 1, the initial insertion portion is formed in advance on one side of the two members apart from the joint portion,
It is characterized in that the shaft-shaped member inserted into the initial insertion portion is moved in a direction intersecting with the joint portion while rotating.

The friction stir welding method according to claim 3 is
The said 1st or 2nd claim WHEREIN: The said initial insertion part is an initial insertion hole which penetrates in the thickness direction of the said joining member, A pair of rotation of the both ends of the said shaft-shaped member inserted in this initial insertion hole is carried out. It is characterized by being pressed by a member.

[0012]

According to the friction stir welding method of claim 1,
When the shaft-shaped member is inserted into the preliminarily provided initial insertion portion and the joint is moved while rotating, the joint is agitated and mixed by the shaft-shaped member, and the plasticized material wraps backward in the moving direction of the shaft-shaped member. Therefore, even if the shaft-shaped member is left in the joint portion after the joining is completed, the overflow of the volume is eliminated, and the post-processing for removing the overflow can be omitted. Moreover, since the shaft-shaped member is left in the joint, the shear strength can be increased.

According to the friction stir welding method of the second aspect, an initial insertion portion is provided in advance on the joining member on one side, and the rotating shaft-like member is moved in a direction intersecting the joining portion to form the joining portion. Since it is left on, the initial insertion part can be reliably formed,
In addition, friction stir welding at the joint can be surely realized.

According to the friction stir welding method of the third aspect, the axial insertion is formed by penetrating the initial insertion portion in the thickness direction of the welding member and pressing both axial ends of the shaft member by the pair of rotating members. Since the members can be supported by both ends, the insertion of the shaft-shaped member into the joint can be made sufficiently deep, and the length of the joint by stirring and mixing extends almost over the entire thickness direction, thus further increasing the joint strength.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment will be described below with reference to the drawings. FIG. 1 shows the product after joining is completed, and FIG. 2 shows a cross section taken along line 2-2. 3 shows a state before joining in FIG. 1, and FIG. 4 shows a cross section taken along line 4-4 together with a rotating member.
5 shows a sliding structure of the rotating member, and FIG. 6 is a variation of FIG.

First, in FIGS. 1 and 2, the joined product is a suspension link arm for an automobile, and the link arm 10 is a rod 11 which is a first joining member.
And an eyeball-shaped bracket 12 and a bush 13 which are second joining members. The bracket 12 has a ring portion 14 that accommodates the bush 13 and a forked portion 15 that projects radially outward from the outer peripheral portion thereof.

The bifurcated portion 15 is provided with a groove-shaped concave portion 16 into which the tip portion of the rod 11 is fitted, and an enlarged portion 17 that bulges outward is provided at an opposing position sandwiching the concave portion 16.
A friction stirrer 18 is formed inside the rod 7 toward the rod 11. The friction stirrer 18 reaches a joint portion 19 formed on the joint surface between the forked portion 15 and the rod 11, and the shaft-shaped member 20 is located on the joint portion 19. The forked portion 15 and the rod 11 are integrated via the friction stirrer 18 and the shaft-shaped member 20.

Reference numerals 21 and 22 are connecting recesses formed at both ends of the shaft-like member 20, 23 is an inner cylinder constituting the bush 13, 24 is a vibration-proof rubber, and is vulcanized and bonded to the ring portion 14 and the inner cylinder 23. And are integrated. The shaft-shaped member 20 can be made of an appropriate metal material such as a super hard material as long as it is harder than the rod 11 and the bracket 12 which are joint members and has a certain heat resistance.

The link arm 10 shown in FIGS.
Although not shown on the half side of FIG.
A pair of left and right brackets 12 having the same structure as that shown in the figure are also provided on the right end side of the. However, the bush in one of the brackets can be arbitrarily changed such that the axial direction of the inner cylinder 23 is different, a bush having a completely different structure is used, or the bracket and the bush itself are omitted.

The bracket 12 is made of a metal such as a light alloy such as aluminum or a plastic material such as a resin.
Extruded in a long direction in the direction of the axis of No. 4, and cut into a predetermined width
It is easily obtained by cutting a standard length into W (Fig. 2). At this time, since the initial insertion hole 25 can be formed integrally with the enlarged portion 17 of the bracket 12 by extrusion molding,
Since it is not necessary to form the initial insertion hole 25 in the post-processing, efficiency is improved. Further, the rod 11 can be appropriately formed into a solid rod shape or a pipe shape using the same material, but the forming method is not necessarily extrusion molding, and various methods are possible.

Next, a method for manufacturing the link arm 10 will be described. As shown in FIG. 3 and FIG. 4, the initial insertion hole 25 is formed in the enlarged portion 17 in advance. The initial insertion hole 25 is integrally formed during extrusion molding as described above, but may be machined separately. As shown in FIG. 4, the initial insertion hole 25 penetrates through the thickness of the forked portion 15 in the cut width direction, and the pin-shaped shaft member 20 is inserted therein. The inner diameter of the initial insertion hole 25 is made slightly larger than the outer diameter of the shaft-shaped member 20, so that the initial insertion hole 25 and the shaft-shaped member 20
A small gap is formed between the two.

In this state, a pair of rotating members 26 and 27 are arranged at both ends of the shaft-like member 20, and the respective connecting projections 2 are arranged.
8 and 29 are engaged with the corresponding connection recesses 21 and 22 and are synchronously rotated in the same direction. At this time, for example, the rotating member 2
6 may be a driving side, and the rotating member 27 may be a non-driving member on the driven side, which simply supports one end of the shaft-shaped member 20. The tips of the rotating members 26 and 27 are pressed against the surface of the joining member to prevent the plasticized material from scattering.

As shown in FIG. 5, at least the rotating member 26 has a structure in which the inner member 30 and the outer portion 31 are fitted inside and outside, and the inner member 30 is connected to the shaft-shaped member 20 and the outer portion 31 is connected. It is slidable around the inner member 30 in the axial direction, and the tip end surface 32 of the inner member 30 is pressed against the surface of the joint between the forked portion 15 and the rod 11.

Further, as shown in FIG. 6, connecting projections 28 and 29 are formed on both ends of the shaft-like member 20, and the rotary members 26 and 2 are formed.
You may form the connection recessed parts 21 and 22 on the 7 side, respectively.

Next, the shaft member 20 is rotated by the rotating members 26 and 27, and the outer portion 31 is slid to the front surface side of the bifurcated portion 15 to press the tip end surface 32, as shown in phantom in FIG. , The joint 19 while rotating integrally
It is moved to the rod 11 side so as to intersect with. Then,
Since a part of the bifurcated portion 15 is plasticized by the shaft-shaped member 20 and flows by being frictionally stirred while flowing, it moves to the rear side in the moving direction of the shaft-shaped member 20 to fill the rear side of the movement locus, and at the same time the initial insertion hole 25 is formed. fill in.

Further, by the tip surface 32 of the outer member 31,
The surface of the contact portion of the bifurcated portion 15 is friction-stirred and plasticized, so that the plasticized material fills a small gap originally present between the shaft-shaped member 20 and the initial insertion hole 25. In addition, instead of sliding the rotating member, the rotating member 2
The shaft-shaped member 20 and the initial insertion hole 25 can also be adjusted by adjusting the pressing amount of each of the tip end portions 6 and 27 a little.
The gaps between can be filled.

In this friction stir welding, the friction stirring at this place is performed only at the meat portion of the forked portion 15, and there is no mixing with the material of the rod 11. However, when the outer peripheral portion reaches the joint portion 19 by the movement of the shaft-shaped member 20, the constituent material of the rod 11 is plasticized, so that it is agitated and mixed with the plasticized material of the bifurcated portion 15.

When the shaft-shaped member 20 moves to the position where it crosses the joint portion 19, the rotation of the rod-shaped member 20 is stopped and the rotating member 2
Separate 6,27. As a result, the shaft member 20 remains on the joint portion 19 and is embedded and integrated in the joint portion between the forked portion 15 and the rod 11. Therefore, the bifurcated portion 15 and the rod 11 are firmly joined by stirring and mixing, and the shear strength at the joining surface is increased by the shaft-shaped member 20.

Moreover, since the shaft-shaped member 20 is inserted into the initial insertion hole 25 formed through the bifurcated portion 15, the length of the shaft-shaped member 20 can be increased to about the thickness of the bracket 12 in the cutting width direction, and the bracket can be rotated. Since both ends are supported by the members 26 and 27, friction stir welding by the shaft member 20 is possible with this length. Therefore, the rod-shaped member 20 can be inserted deep enough to the wall thickness of the bifurcated portion 15 and the rod 11, and the stirring and mixing is generated in the range extending over the entire wall thickness direction, so that a sufficiently large bonding strength can be obtained. .

In addition, by forming the initial insertion hole 25 in advance, even if the shaft-shaped member 20 remains in the joint portion, the plasticized material corresponding to the volume can be absorbed in the initial insertion hole 25. Therefore, the plasticized material can be prevented from overflowing the joint surface. As a result, post-processing for removing the overflow portion after joining can be omitted, and the efficiency of joining work can be improved.

Moreover, since a part of the rotating member 27 is used as the slidable outer part 31 to frictionally stir the surface of the forked part 15, the initial insertion hole 25 is formed slightly larger than the shaft-shaped member 20. Also, it is possible to fill this gap and maintain a good appearance of the joint. In addition, by enlarging the initial insertion hole 25, the shaft-shaped member 20 can be easily inserted. Besides, the bracket 12 thus formed
In comparison with the case where the initial insertion hole 25 is formed on the joint portion 19, the initial insertion hole 25 is formed on the forked portion 25 side which is a single member, so that the initial insertion hole 25 can be easily formed and the post-processing is not necessary. Friction stir welding with a relatively good appearance can be realized.

The invention of the present application is not limited to the above-described embodiments, and various modifications and applications are possible within the same principle of the invention. The joined product of the embodiment in the manufacturing method of the present application is an example,
It can be applied to anti-vibration members other than link arms or jointed products for various other purposes. Further, if the shaft-shaped member 20 reaching the joint portion 19 is further moved along the joint portion 19,
The joint strength can be further enhanced. Further, the initial insertion hole 25 may be formed on the joint portion 19, and the mixture may be stirred and mixed along the joint portion 19 from the beginning. Further, instead of the initial insertion hole 25, a recess that does not penetrate may be used as the initial insertion portion.

[Brief description of drawings]

[Figure 1] Product after joining is completed

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a diagram showing a state before joining in FIG.

FIG. 4 is a view showing a cross section taken along line 4-4 of FIG. 3 together with a rotating member.

FIG. 5 is a diagram showing a sliding structure of a rotating member.

FIG. 6 is a variation of FIG.

FIG. 7: Conventional friction stir welding method

[Explanation of symbols]

10: Link arm, 11: Rod, 12: Bracket, 13: Bush, 15: Forked part, 18: Friction stir part, 19: Joined part, 20: Shaft member, 25: Initial insertion hole, 26: Rotating member , 27: rotating member

Claims (3)

[Claims] 1. A friction stir welding method in which a shaft-shaped member is rotated and joined at a joining portion of two joining members to be joined to each other, wherein the one side of the two joining members or the joining portion is preliminarily described above. An initial insertion part for inserting the shaft-shaped member is formed in advance, and the shaft-shaped member is inserted into the initial insertion part and moved while being rotated to stir and mix the joint part, and the shaft-shaped member is inserted. A friction stir welding method, characterized in that it remains buried on the joint. 2. The initial insertion portion is formed in advance on one side of the two members apart from the joint portion, and the joint portion is rotated while rotating the shaft-shaped member inserted into the initial insertion portion. The friction stir welding method according to claim 1, wherein the friction stir welding method is carried out in a direction intersecting with. 3. The initial insertion part is an initial insertion hole that penetrates in the thickness direction of the joining member, and both ends of the shaft-shaped member inserted in the initial insertion hole are held by a pair of rotating members. The friction stir welding method according to claim 1 or 2, wherein.