JP2002126881A - Friction joining method - Google Patents

Abstract

(57) [Summary] To provide a friction joining method capable of joining lap joints with high quality. SOLUTION: A laminated surface 4 to be joined is changed into an uneven shape in the axial direction of the friction joining tool T. As a result, the plastic flow surface formed substantially perpendicular to the rotation axis of the friction welding tool T crosses the laminated surface 4 of the members to be welded P. That is, a portion where one member to be welded P and the other member to be welded P are mixed is changed in the axial direction of the friction welding tool T,
The two joined members P, P on the laminated surface 4 are sufficiently mixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction welding method, and more particularly to a friction welding method utilizing frictional heat generated by rotation of a friction welding tool.

[0002]

2. Description of the Related Art A friction welding method utilizing frictional heat generated by rotation of a friction welding tool is well known as described in, for example, Japanese Patent No. 2712838. In this friction joining method, as shown in FIG. 1, which is a view showing an embodiment of the present invention, a pin 2 having a smaller diameter is provided at a distal end portion of a tool main body 1, and A friction welding tool T having a shoulder 3 around the mounting portion of the pin 2 is used. Then, the pin 2 is inserted into the joint of the pair of members P, P made of aluminum alloy or the like while rotating, and the shoulder 3 is brought into contact with the surfaces of the members P, P while the shoulder 3 is in contact with the surface of the joint. The welding tool T is relatively moved. At this time, the friction welding tool T moves with respect to an axis perpendicular to the surface of the member P to be welded.
It is necessary to arrange such that the front end side thereof is inclined forward by a predetermined angle in the joining progress direction so that the shoulder 3 contacts the joint surface on the rear side in the joining proceed direction. Then, frictional heat is generated by the rotation of the friction welding tool T. The frictional heat reduces the deformation resistance in the welded portion and the vicinity thereof, generates plastic flow, and changes the base material structure of the members to be welded P, P. Stirring is carried out, and after cooling, bonding is performed by integrating the base material structure.

[0003]

By the way, in the above-mentioned conventional friction welding method, the present inventors have proposed a method in which a pair of members to be welded P, P are stacked one on top of another and the laminated surfaces are overlapped and joined. It has been found that cracks may occur in portions corresponding to the above, or that an oxide film may remain in a layered manner. When the cause was examined, the following became clear. That is, at the time of the friction welding, a plastic flow is generated in the vicinity of the welded portion. This plastic flow mainly occurs in a plane substantially perpendicular to the rotation axis of the friction welding tool T, and the axial direction of the friction welding tool T, that is, the workpiece Since it is unlikely to occur in the thickness direction of P, the stacked surfaces of the pair of members to be joined P, P flow on substantially the same plane. Insufficient mixing of components,
This means that the oxide film on the laminated surface remains in a layer state as it is.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and an object of the present invention is to provide a friction joining method capable of joining a lap joint as described above with high quality. Is to do.

[0005]

According to a first aspect of the present invention, there is provided a friction welding method, comprising: laminating a pair of members to be welded, and inserting a pin of a rotationally driven friction welding tool in a direction crossing the lamination surface. A plastic flow is generated on the lamination surface by the method of friction joining in which both members to be joined are overlapped on the lamination surface, wherein the lamination surface to be joined is changed in the axial direction of the friction welding tool. I have.

In the friction welding method of the first aspect, the lamination surface of the members to be welded is changed in the axial direction of the friction welding tool, so that the lamination surface is formed substantially perpendicular to the rotation axis of the friction welding tool. The plastic flow surface crosses the lamination surface of the members to be joined. That is, the portion where one member to be joined and the other member to be joined are mixed changes in the axial direction of the friction welding tool. As a result, both members to be joined on the lamination surface can be sufficiently mixed, and the occurrence of defects such as cracks and remaining oxide film layers can be suppressed, and the joining quality can be improved.

According to a second aspect of the present invention, there is provided the friction joining method.
In the above method, the width of the lamination surface to be changed is not more than the diameter of the pin.

In the friction welding method according to the second aspect, the width of the lamination surface that is changed in the axial direction of the friction welding tool is equal to or smaller than the diameter of the pin. Thus, it is possible to obtain a state as if it were a lap joint between planes. Therefore, it is not necessary to consider a change in joint strength due to a change in joint shape, and the applicable range is not limited. Further, since the width of the lamination surface to be changed may be narrow, the processing can be easily performed.

The friction joining method according to claim 1 or 2 may be carried out continuously in a linear manner or locally in a spot manner.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, specific embodiments of the friction joining method of the present invention will be described in detail with reference to the drawings. First, in FIG. 1, T indicates a friction welding tool, in which a pin 2 having a smaller diameter is provided at the tip of the tool body 1, and the periphery of the mounting portion of the pin 2 on the tip face of the tool body 1. Are configured as shoulders 3.
P, P are plate-like members to be joined stacked one above the other, and the pin 2 at the tip of the friction welding tool T passes through the upper member to be joined P, and is further fixed to the lower member to be joined P. When the friction welding tool T is rotated and the friction welding tool T and the workpieces P, P are relatively moved while the friction welding tool T is being inserted in the depth of insertion, the stacked surfaces of the workpieces P, P are overlapped and joined. It has become so.

In the members to be joined P, the laminated surface (joining surface) 4 to be joined is formed as an uneven surface. That is, as shown in FIG. 2 (a), a ridge 5 having a triangular cross section is formed on the upper surface of the lower member P, and a concave groove having a triangular cross section is formed on the lower surface of the upper member P. 6 are formed, and the surfaces of the ridge 5 and the groove 6 are in close contact with each other without any gap. Then, friction welding is performed such that the rotation axis of the friction welding tool T is located at the top of the ridge 5.

In the above friction welding method, the members to be welded P,
The lamination surface 4 to which P is bonded changes in the vertical direction, that is, the axial direction of the friction welding tool T due to the formation of the ridges 5 and the concave grooves 6. Therefore, the plastic flow surface formed substantially perpendicular to the rotation axis of the friction welding tool T crosses the inclined laminated surface 4 of the members P to be welded. That is, the portion where one member to be joined P and the other member to be joined P are mixed changes in the axial direction of the friction welding tool T. As a result, on the lamination surface 4,
The two members to be joined P, P are sufficiently mixed with each other, and the occurrence of defects such as cracks and remaining oxide film layers can be suppressed, and the joining quality can be improved.

FIG. 2B shows an embodiment in which the positions of the projections 5 and the grooves 6 having a triangular cross section are inverted. 3 (a) and 3 (b) show an embodiment of a ridge 5 and a groove 6 having a trapezoidal cross section. Further, FIG.
(A) and (b) show an embodiment of a ridge 5 and a concave groove 6 having a rectangular cross section. FIG. 5 further shows an example in which the laminated surface 4 to be joined is changed in the axial direction of the friction welding tool T by forming the laminated surface 4 as an inclined surface. In FIG. 6, grooves 6, 6 are formed in upper and lower members to be joined P, respectively, and a band-like member 7 is fitted in the grooves 6, 6.
Is changed in the axial direction of the friction welding tool T. In any of these cases, the portion where one member to be welded P and the other member to be welded P are mixed changes in the axial direction of the friction welding tool T. As a result,
On the laminated surface 4, the members to be joined P, P are sufficiently mixed with each other, so that generation of defects such as cracks and remaining oxide film layers can be suppressed, and the joining quality can be improved. In particular, as shown in FIGS. 4A, 4B, and 6, when the width of the lamination surface 4 changed in the axial direction of the friction welding tool is set to be equal to or less than the diameter of the pin 2, the lamination is performed after the welding is completed. Since the changed part of the surface does not remain and a state as if it is a lap joint of planes is obtained, consideration for a change in joint strength due to a change in joint shape is unnecessary, and its application range is not limited And the advantage is produced. Also, the lamination surface 4 to be changed
, That is, the widths of the ridges (projections) 5 and the grooves (recesses) 6 may be narrow, so that the processing can be easily performed.

Although the specific embodiment of the friction joining method of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications are made within the scope of the present invention. It is possible to For example, in each of the embodiments described above, an example in which welding is performed continuously in a linear shape is shown. However, as shown in FIG. The invention can be applied. Also, as shown in FIGS. 8 (a) and 8 (b) to FIG. 11, it is possible to simultaneously perform butt joining of a pair of members to be joined P and lap joining of another member to be joined P. Further, in each of the above-described embodiments, the laminating surface 4 is made uneven in the lateral direction (width direction) of the joining progress direction. However, this may be changed in an uneven manner along the joining progress direction.

[0015]

According to the friction welding method of the first aspect, the portion where one member to be welded and the other member to be welded are changed in the axial direction of the friction welding tool. The two members to be joined on the lamination surface are sufficiently mixed with each other, so that generation of defects such as cracks and remaining oxide film layers can be suppressed, and the joining quality can be improved.

According to the friction joining method of the second aspect, after the joining is completed, the changed portion of the lamination surface does not remain, and a state as if it is a lap joint of flat surfaces can be obtained.
There is no need to consider changes in the joint strength due to changes in the joint shape, and the applicable range is not limited. Further, since the width of the lamination surface to be changed may be narrow, the processing can be easily performed.

The friction joining method according to claim 1 or 2 may be carried out continuously in a linear manner or locally in a spot manner.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an entire embodiment of a friction joining method according to the present invention.

FIG. 2 is a cross-sectional view showing a shape of a lamination surface of the lap joint in the embodiment.

FIG. 3 is a cross-sectional view showing a modified example of the shape of the lap joint.

FIG. 4 is a sectional view showing another modification of the shape of the lap joint.

FIG. 5 is a sectional view showing still another modification of the shape of the lap joint.

FIG. 6 is a sectional view showing another modification of the shape of the lap joint.

FIG. 7 is an explanatory view showing the overall schematic configuration of another embodiment of the friction joining method of the present invention.

FIG. 8 is a cross-sectional view showing a shape of a lamination surface of a lap joint according to still another embodiment.

FIG. 9 is a cross-sectional view showing a modified example of the shape of the lap joint.

FIG. 10 is a sectional view showing another modified example of the shape of the lap joint.

FIG. 11 is a cross-sectional view showing still another modification of the shape of the lap joint.

[Description of Signs] 1 Tool main body 2 Pin 3 Shoulder 4 Laminated surface 5 Ridge 6 Concave groove 7 Band member T Friction welding tool P Member to be joined

Continued on the front page (72) Inventor Takayuki Hattori 2-1-1-18 Wadayama-dori, Hyogo-ku, Kobe Kawasaki Heavy Industries, Ltd. Hyogo Plant F-term (reference) 4E067 BG00 DA13 DA17

Claims (3)

[Claims] 1. A pair of members to be welded are stacked, and a pin of a friction welding tool that is driven to rotate is inserted from a direction intersecting with the stacking surface to generate plastic flow on the stacking surface. A friction joining method in which two members to be joined are overlapped and joined, wherein a layer to be joined is changed in an axial direction of the friction joining tool. 2. The friction joining method according to claim 1, wherein the width of the lamination surface to be changed is smaller than the diameter of the pin. 3. The friction welding method according to claim 1, wherein the friction welding is performed continuously in a linear shape or locally in a spot shape.