JP4309820B2 - Friction stir welding tool - Google Patents

Description

  The present invention relates to a friction stir welding tool that joins joints with generated frictional heat by pressing a joint part where materials to be joined are pressed together with a pin tool and moving the stirring pin protruding from the pin tool while rotating. In particular, the present invention relates to a friction stir welding tool that can be joined without scraping off a joining portion in which a curved surface is formed.

  FIG. 4 is a view showing a friction stir welding tool described in Patent Document 1 below. This friction stir welding tool 100 joins the butted end surfaces of a pair of aluminum alloy plates 210 and 220. For this purpose, the aluminum alloy plates 210 and 220 are brought into contact with each other, and the friction stir welding tool 100 moves along the joint 200. In the friction stir welding tool 100, pin tools 101 and 102 are arranged at intervals between the upper and lower surfaces of the plates 210 and 220, and a stirring pin 103 that rotates and moves the joint is provided coaxially with the pin tools 101 and 102. Yes. The integrally formed pin tools 101 and 102 and the stirring pin 103 are configured to be rotated by a motor 104.

The friction stir welding tool 100 that rotates by driving the motor 104 moves in the direction of arrow F while the stirring pin 103 contacts the aluminum alloy plates 210 and 220 at the coupling portion 200. At this time, the stirring pin 103 creates a partial region of the plastic material around it, and the pin tools 101 and 102 press the plates 210 and 220 from above and below to prevent the material from being lost from the plastic zone. Therefore, in such friction stir welding, the plates 210 and 220 are heated and softened at the abutting portion of the joining portion 200, and are solid-phase joined by a plastic material formed by plastic flow.
JP 07-505090 A (4th page, FIG. 1)

  However, the conventional friction stir welding tool 100 has a problem of scraping a plate or the like as a material to be joined. That is, in the conventional friction stir welding tool 100, as shown in FIG. 4, the pin tools 101 and 102 have a cylindrical shape, and the shoulder 110 on the surface in contact with the material to be joined has a square shape around the shoulder 110. . In addition to those shown in FIG. 4, there is also a friction stir welding tool in which the periphery of the shoulder of the pin tool has a blade shape so that the material to be joined can be actively taken into the joint during friction stirring. .

For example, there is a hollow extrusion mold material 200 as shown in FIG. The hollow extruded mold 200 is a truss-like panel in which a plurality of inclined plates 203 are alternately stretched between two parallel upper and lower plates 201 and 202 with different inclinations.
And in order to friction stir weld this hollow extrusion mold material 200, the end surfaces are faced | matched and it moves along a joining line, rotating the friction stir welding tool 100. FIG. At that time, the joined portion between the upper surface plates 201 is flat and there is no problem, but the joined portion between the lower surface plates 202 becomes a curved surface 205 as indicated by a broken line from the inclined plate 203 to the lower surface plate 202 inside. Therefore, the curved surface 205 portion is scraped off.

That is, in the conventional friction stir welding tool 100, since the periphery of the shoulder 110 is a corner, the portion of the curved surface 205 is scraped off. This is not preferable because the required strength of the hollow extrusion mold material 200 is also lowered.
Further, in order to eliminate such scraping of the curved surface 205, it is only necessary to widen the interval between the slope plates 203 so that the curved surface does not hit the shoulder of the pin tool 102. However, this lowered the rigidity of the joint, which was not preferable in terms of strength.

  Therefore, an object of the present invention is to provide a friction stir welding tool that performs friction stir welding without scraping off a material to be joined in order to solve the above-described problem.

The friction stir welding tool of the present invention is inserted while rotating the stirring pin into the joint where the materials to be joined are abutted, and is moved along the joint as it is, so that the friction stir is caused by frictional heat and the joint is moved. provided for the purpose of joining, the stirring pin is provided coaxially with the cylindrical pin tool for pressing the joint, its pin tool, around the shoulder for pressing the material to be joined, the joint A curved surface is formed in accordance with the shape of the curved surface portion of the material to be joined .
Moreover, the friction stir welding tool of the present invention is characterized in that the pin tool is located above and below the stirring pin so as to sandwich the joined portion of the material to be joined.
The friction stir welding tool of the present invention is characterized in that the pin tool has a curved surface on the shoulder of one of the upper and lower pin tools, and the shoulder of the other pin tool is a flat surface.

Therefore, according to the friction stir welding tool of the present invention, when joining a material to be joined having a curved surface at the joint, the pin tool presses the butted portion of the material to be joined from both above and below, and continues along the joint. The stirring pin moves while rotating. Then, the stir pin creates a partial area of plastic material at the abutment, and the pin tool prevents the material from being lost from the plastic zone, but in the curved part of the joint, a curved surface is formed around the shoulder. Since it is formed, the material to be joined is not scraped off.
Therefore, in the friction stir welding tool of the present invention, it becomes possible to avoid inconveniences in strength such as causing stress concentration and fatigue failure, and efficient joining design can be performed on the joining portion of the materials to be joined. It becomes possible.

Next, an embodiment of a friction stir welding tool according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a construction situation in the friction stir welding tool of the present embodiment. Here, it shows about the case where a hollow extrusion mold material is joined similarly to the prior art example mentioned above.
The hollow extrusion mold 200 is a panel having a truss structure in which a plurality of inclined plates 203 are alternately stretched between two parallel upper and lower plates 201 and 202 as described above. .

  The slope plate 203 is designed to increase the rigidity of the hollow extrusion mold member 200. That is, when the center line L of the slope plate 203 is viewed, the intersection is located inside the upper surface plate 201 and the lower surface plate 202 as much as possible to form a triangle and the structure is more stable and the rigidity is higher. Therefore, it is preferable that the slope plate 203 provided with the joint portion interposed therebetween is also joined closer. Therefore, when the hollow extruded molds 200 are brought into contact with each other by friction stir welding, the inclined plates 203 are made as close as possible. For this reason, in the conventional friction stir welding tool 100, the curved surface 205 portion continuous from the inclined plate 203 formed at the bonded portion of the lower surface plates 202 to the lower surface plate 202 has been cut.

  On the other hand, the friction stir welding tool 1 of the present embodiment has a shape that allows construction without scraping the curved surface portion. The friction stir welding tool 1 is provided with pin tools 2 and 3 so as to sandwich the upper and lower surfaces of the materials to be joined, and the stirring pin 4 is integrally formed on the same axis therebetween. The pin tools 2 and 3 and the stirring pin 4 are configured to be rotated by a motor (not shown). In the friction stir welding tool 1 of the present embodiment, the pin tools 2 and 3 that sandwich the material to be joined are formed with curved surfaces around the shoulders 5 and 6. In particular, the curved surface of the shoulder 6 of the pin tool 3 is formed so as to match the curved surface 205 of the portion continuous from the inclined plate 203 to the lower surface plate 202 that has been cut off conventionally.

  Therefore, when joining the hollow extruded molds 200 with the end portions joined together, the upper surface plate 201 is joined by the conventionally used friction stir welding tool 100 in order to join the flat surfaces. On the other hand, since the lower surface plate 202 has the curved surface 205, the friction stir welding tool 1 of this embodiment is used. In addition, since the joining of the upper surface plate 201 is the same as that of the conventional example, the description here is omitted.

When joining the lower surface plate 202 of the hollow extrusion mold material 200, the butted portions of the lower surface plate 202, which is the material to be joined, are sandwiched between the pin tools 2 and 3 from the vertical direction. And the stirring pin 4 moves while rotating as it is along a joining part.
Then, the stirring pin 4 creates a partial region of the plastic material at the abutting portion, and the pin tools 2 and 3 prevent the material from being lost from the plastic zone. Therefore, the abutted lower surface plates 202 are solid-phase bonded by a plastic material formed by plastic flow, with the butted portion of the bonding portion generating heat and softening.

At this time, in the friction stir welding tool 1, the pin tool 3 presses the curved surface 205 of the lower surface plate 202 and the shoulder 6 on which the same curved surface is formed presses the surfaces together. Accordingly, the material of the joined portion that has been softened by heat generation is prevented from being lost without scraping the hollow extrusion mold material 200.
In this way, in the hollow extrusion mold material 1 of the present embodiment, the material to be joined having a curved surface at the joining portion is scraped off during friction stir welding, so that the strength is not reduced. There is no need for inefficient structural design.

  Next, FIG. 2 is a diagram showing a construction situation in another material to be joined using the friction stir welding tool 1. The material to be joined 300 is a plate material that is curved and extends in a direction penetrating the drawing as shown. Even when the materials to be joined 300 are friction stir welded, the conventional friction stir welding tool 100 scrapes off the curved upper surface side in the same manner as the joining of the bottom plate 202 of the hollow extrusion mold material 200. Therefore, when the friction stir welding tool 1 of the present embodiment is used, the pin tools 2 and 3 sandwich the butted portion of the material to be joined 300 from above and below and move along the joining line as they are.

Thus, when joining the to-be-joined material 300, the upper and lower pin tools 2 and 3 pinch | interpose the butt | matching part of the to-be-joined material 300 which is a to-be-joined material. And the stirring pin 4 moves while rotating as it is along a joining part.
Then, the stirring pin 4 creates a partial region of the plastic material at the abutting portion, and the pin tools 2 and 3 prevent the material from being lost from the plastic zone. Therefore, the materials to be joined 300 joined together are solid-phase joined by a plastic material formed by plastic flow, with the abutting portion of the joining portion generating heat and softening.

  At this time, the friction stir welding tool 1 prevents the material of the joined portion softened by heat generation from being washed away without scraping off the material 300 to be joined in which the pin tool 3 having a curved surface around the shoulder 5 is curved. Therefore, the to-be-joined material 300 does not need to have an inefficient structural design in which the thickness is excessively reduced in consideration of the scraping without causing a decrease in strength due to the scraping.

  By the way, the friction stir welding tool is not limited to sandwiching the material to be joined as shown in FIGS. 1 and 2, but by providing a jig 400 for receiving the material 300 to be joined as shown in FIG. There is also a friction stir welding tool 10 in which a stirring pin 12 is protruded from the tool 11. When such a friction stir welding tool 10 is used, since the pressing load applied through the pin tool 11 is large, it is not very suitable for the hollow extrusion mold material 200 as shown in FIG. 1, but as shown in FIG. This is effective for the material to be joined 300 that can receive the load by the above.

Therefore, when the friction stir welding tool 10 is used, the pin tool 11 presses the butted portion of the material to be joined 300 from above and moves along the joining portion as it is. And the stirring pin 12 makes the partial area | region of a plastic material in the butt | matching part, The pin tool 11 is preventing that material is lost from a plastic zone. Therefore, the material to be bonded 300 is solid-phase bonded by a plastic material that is generated by softening the abutting portion of the bonded portion and plastically flowing.
At this time, the friction stir welding tool 10 prevents the material of the joined portion that has been softened by heat generation from flowing out without the pin tool 11 scraping off the material 300 to be joined. Therefore, the to-be-joined material 300 does not need to have an inefficient structural design in which the thickness is excessively reduced in consideration of the scraping without causing a decrease in strength due to the scraping.

Therefore, according to the friction stir welding tools 1 and 10 of the present embodiment, even if the joining portion of the materials to be joined has a curved shape, a curved surface is formed around the shoulder 6 so as to match the curved surface of the joining portion. As a result, the material to be joined is not scraped off. For this reason, it is possible to avoid inconveniences in strength such as stress concentration and fatigue failure.
In addition, since the material to be joined is not scraped off, an efficient joining design can be performed on the joining portion of the material to be joined. And it became unnecessary to make an extra thick structure in consideration of strength reduction due to scraping, and the effect on the lightweight structure design was increased for the materials to be joined.

As mentioned above, although one Embodiment of the friction stir welding tool of this invention was described, this invention is not limited to this, A various change is possible in the range which does not deviate from the meaning.
For example, in the friction stir welding tool 1 of the above embodiment, the shoulders 5 and 6 of both pin tools 2 and 3 have curved surfaces, but the pin tool 2 that presses down the curved surface on the flat surface or the direction of escaping. The three shoulders 5 and 6 may be flat as in the conventional case.

It is one Embodiment of a friction stir welding tool, Comprising: It is the figure which showed the case where a hollow extrusion type material is joined. It is one Embodiment of a friction stir welding tool, Comprising: It is the figure which showed the case where the curved board | plate material is joined. It is other embodiment of a friction stir welding tool, Comprising: It is the figure which showed the case where the curved board | plate material is joined. It is the figure which showed the conventional friction stir welding tool. It is the figure which showed the case where a hollow extrusion type | mold material is joined with the conventional friction stir welding tool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Friction stir welding tool 2,3 Pin tool 4 Stirring pins 5,6 Shoulder 200 Hollow extrusion mold material

Claims (3)

In a friction stir welding tool for friction stir by frictional heat to join the joint by inserting the stirring pin into the joint where the materials to be joined are rotated and moving along the joint as it is. ,
The stirring pin is provided coaxially with a cylindrical pin tool that presses the joint , and the pin tool is around the shoulder that presses the material to be joined, and is a curved surface portion of the material to be joined that exists in the joint. A friction stir welding tool characterized in that a curved surface is formed in accordance with the shape of the friction stir welding tool. In the friction stir welding tool according to claim 1,
The friction stir welding tool according to claim 1, wherein the pin tool is located above and below the stirring pin so as to sandwich the joint portion of the material to be joined. In the friction stir welding tool according to claim 2,
The pin tool has a curved surface formed on the shoulder of one of the upper and lower pin tools, and the shoulder of the other pin tool has a flat surface.

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