JP6794945B2 - Joining method - Google Patents

Description

The present invention relates to a joining method for joining metal members by friction stir welding.

For example, Patent Document 1 discloses a joining method for joining a first metal member and a second metal member by friction stir welding. In the joining method, after the first metal member and the second metal member are butted to form a butt portion, only the stirring pin of the rotary tool is brought into contact with the first metal member and the second metal member to form the butt portion. On the other hand, friction stir welding is performed.

Japanese Unexamined Patent Publication No. 2013-039613

In the joining method disclosed in Patent Document 1, since the plastically fluidized metal is not pressed by the shoulder portion of the rotating tool, there is a problem that the plastically fluidized metal leaks to the outside and the joint portion becomes short of metal.
Therefore, an object of the present invention is to provide a joining method capable of preventing a metal shortage at the joining portion.

The first invention for solving the above-mentioned problems is a joining method for joining a first metal member and a second metal member by frictional stirring using a rotating tool for joining, which is provided with a stirring pin. At least the ends of the one metal member and the second metal member both have the first horizontal plate protruding from the base end of one side surface of the vertical plate and the second from the tip end of one side surface of the vertical plate. The horizontal plate is formed in a U-shape with a protruding cross section, so that the other side surface of the vertical plate in the first metal member and the surface of the first horizontal plate in the second metal member are flush with each other. A butt step of forming a butt portion by abutting the surface of the first horizontal plate of the first metal member and the other side surface of the vertical plate of the second metal member, and the first of the first metal member. An auxiliary member arranging step of arranging an auxiliary member on the first metal member and the second metal member so as to cover an inner corner composed of the horizontal plate and the second horizontal plate of the second metal member, and the stirring pin. Is inserted from the surface side of the auxiliary member, and with only the stirring pin in contact with the auxiliary member, the first metal member, and the second metal member, the rotary tool for main joining is formed along the butt portion. The main joining step of performing frictional stirring joining of the auxiliary member, the first metal member, and the second metal member by relatively moving the auxiliary member, and the auxiliary member having burrs formed on the first metal member and the second metal member. It is characterized by including a removal step of removing from a metal member.

The second invention for solving the above-mentioned problems is a joining method for joining a first metal member and a second metal member by frictional stirring using a rotating tool for joining, which is provided with a stirring pin. At least the ends of the one metal member and the second metal member both have the first horizontal plate protruding from the base end of one side surface of the vertical plate and the second from the tip end of one side surface of the vertical plate. The horizontal plate is formed in a U-shape with a protruding cross section, so that the other side surface of the vertical plate in the first metal member and the surface of the first horizontal plate in the second metal member are flush with each other. A butt step of forming a butt portion by abutting the surface of the first horizontal plate of the first metal member and the other side surface of the vertical plate of the second metal member, and the first of the first metal member. An auxiliary member arranging step of arranging an auxiliary member on the first metal member or the second metal member so as to cover an inner corner composed of the horizontal plate and the second horizontal plate of the second metal member, and the stirring pin. Is inserted from the surface side of the auxiliary member, and with only the stirring pin in contact with the auxiliary member, the first metal member, and the second metal member, the rotary tool for main joining is formed along the butt portion. The main joining step of performing frictional stirring joining of the auxiliary member, the first metal member, and the second metal member by relatively moving the auxiliary member, and the auxiliary member having burrs formed on the first metal member or the second metal member. It is characterized by including a removal step of removing from a metal member.

According to the joining method in the first invention and the second invention, the first metal member and the second metal member are joined, and in addition to the first metal member and the second metal member, the auxiliary member is also rubbed at the same time. By stirring and joining, it is possible to prevent a metal shortage at the joint.
Further, since the burrs generated by friction stir welding can be removed from the metal member together with the auxiliary member, the step of removing the burrs becomes easy.

In the above case, it is desirable to include a temporary joining step of inserting only the stirring pin of the temporary joining rotary tool into the inner corner and performing friction stir welding at the spot before the auxiliary member arranging step.
Further, before the auxiliary member arranging step, only the stirring pin of the temporary joining rotary tool is inserted into the butt portion on the base end side of the vertical plate in the second metal member to perform friction stir welding at the spot. It is desirable to include a joining step.

According to such an invention, the load acting on the friction stir welding device can be reduced by temporarily attaching spots to the inner corners and the abutting portions in a state where only the stirring pin is in contact with the metal member. Further, the process time can be shortened as compared with the case where the temporary joining is performed on the inner corner and the entire length of the butt portion as in the conventional case.

In the above case, it is desirable that the temporary joining rotation tool and the main joining rotation tool are the same rotation tool.
According to such an invention, since it is not necessary to replace the rotation tool, work efficiency can be improved.

In the above case, it is desirable to include a temporary joining step of joining the inner corners with spots by welding before the auxiliary member arranging step. Further, as the welding, MIG welding, TIG welding or laser welding can be used.
Further, it is desirable to include a temporary joining step of joining the butt portion on the base end side of the vertical plate of the second metal member with a spot by welding before the auxiliary member arranging step. Further, as the welding, MIG welding, TIG welding or laser welding can be used.

According to such an invention, the load acting on the friction stir welding device can be reduced by temporarily attaching spots to the inner corners and the abutting portions. In addition, the process time can be shortened as compared with the case of temporarily joining the entire length of the butt portion as in the conventional case.

According to the joining method according to the present invention, it is possible to prevent a metal shortage at the joint.

It is a perspective view which shows the state before the butt process of the joining method which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the state after the butt step of the joining method which concerns on 1st Embodiment of this invention. It is a perspective view which shows the 1st temporary joining process of the joining method which concerns on 1st Embodiment of this invention. It is a perspective view which shows the 2nd temporary joining process of the joining method which concerns on 1st Embodiment of this invention. It is a perspective view which shows the 1st auxiliary member arrangement process of the joining method which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the 1st auxiliary member arrangement process of the joining method which concerns on 1st Embodiment of this invention. It is a perspective view which shows the 1st main joining process of the joining method which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the 1st main joining process of the joining method which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the 1st removal step of the joining method which concerns on 1st Embodiment of this invention. It is a perspective view which shows the 2nd auxiliary member arrangement process of the joining method which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the 2nd auxiliary member arrangement process of the joining method which concerns on 1st Embodiment of this invention. It is a perspective view which shows the 2nd joining process of the joining method which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the 2nd main joining process of the joining method which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the 2nd removal step of the joining method which concerns on 1st Embodiment of this invention. It is a perspective view which shows another example of the 1st temporary joining process of the joining method which concerns on 1st Embodiment of this invention. It is a perspective view which shows another example of the 2nd temporary joining process of the joining method which concerns on 1st Embodiment of this invention. It is a perspective view which shows the 1st auxiliary member arrangement process of the joining method which concerns on 2nd Embodiment of this invention. It is a perspective view which shows the 1st main joining process of the joining method which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the 1st main joining process of the joining method which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the 1st removal step of the joining method which concerns on 2nd Embodiment of this invention. It is a perspective view which shows the 1st auxiliary member arrangement process of the joining method which concerns on 3rd Embodiment of this invention. It is a perspective view which shows the 1st main joining process of the joining method which concerns on 3rd Embodiment of this invention.

[First Embodiment]
The joining method according to the first embodiment of the present invention will be described in detail. In the first embodiment, the first metal member and the second metal member, which are two metal members having a U-shaped cross section, are joined. In the joining method according to the first embodiment, a butt step, a temporary joining step, an auxiliary member arranging step, a main joining step, and a removing step are performed. In the following description, the "front surface" means the surface opposite to the "back surface".

The butt step is a step of butt-butting the first metal member 10 having a U-shaped cross section and the second metal member 20 shown in FIG.
The materials of the first metal member 10 and the second metal member 20 are appropriately selected from frictionally agitable metals such as aluminum, aluminum alloys, copper, copper alloys, titanium, titanium alloys, magnesium and magnesium alloys.

The first metal member 10 is a profile having a U-shaped cross section. The first metal member 10 includes a vertical plate 11, a first horizontal plate 12 projecting from a base end portion 11c of one side surface 11a of the vertical plate 11 toward one side, and a tip end portion of one side surface 11a of the vertical plate 11. It is composed of a second horizontal plate 13 projecting from 11d toward one side. In the example of FIG. 1, the protruding direction of the first horizontal plate 12 and the protruding direction of the second horizontal plate 13 are the same, but the present invention is not limited to this.
The first horizontal plate 12 is bent at a right angle from the base end portion 11c of the vertical plate 11 (the right end portion of the vertical plate 11 in FIG. 1) toward one side, and the tip end portion 11d of the vertical plate 11 (vertical plate 11 in FIG. 1) The second horizontal plate 13 is bent at a right angle from the left end portion of the) toward one side.
As shown in FIG. 2, a corner portion 14 bent at a right angle is formed at a connecting portion between the vertical plate 11 and the first horizontal plate 12 and the second horizontal plate 13. A curved surface curved in an arc shape is formed on the outer top of the corner portion 14.

As shown in FIG. 1, the second metal member 20 is a profile having a U-shaped cross section, and is a member having the same shape as the first metal member 10. That is, the second metal member 20 is a vertical plate 21 and a first horizontal plate 22 projecting from the base end portion 21c (lower end portion of the vertical plate 21 in FIG. 1) of one side surface 21a of the vertical plate 21 toward the other. It is composed of a second horizontal plate 23 protruding from the tip end portion 21d of one side surface 21a of the vertical plate 21 (the upper end portion of the vertical plate 21 in FIG. 1) toward the other side.

As shown in FIG. 2, a corner portion 24 bent at a right angle is formed at a connecting portion between the vertical plate 21, the first horizontal plate 22, and the second horizontal plate 23. A curved surface curved in an arc shape is formed on the outer top of the corner portion 24.

As shown in FIG. 2, in the butt step, the first metal member 10 is arranged so as to open upward. Further, the second metal member 20 is arranged so as to open in the lateral direction on the side opposite to the first metal member 10. Then, the other side surface 11b of the vertical plate 11 of the first metal member 10 and the surface 22a of the first horizontal plate 22 of the second metal member 20 are flush with each other, and the first horizontal plate of the first metal member 10 is flush with each other. The surface 12a of the 12 and the other side surface 21b of the vertical plate 21 of the second metal member 20 are brought into surface contact with each other and abutted against each other.

When the surface 12a of the first horizontal plate 12 of the first metal member 10 and the other side surface 21b of the vertical plate 21 of the second metal member 20 are abutted against each other, the corner portion on the tip end 21d side of the second metal member 20 The butt portion J1 is formed by the 24 and the surface 12a of the first horizontal plate 12.
Further, the butt portion J2 is formed by the corner portion 14 on the base end portion 11c side of the first metal member 10 and the corner portion 24 on the base end portion 21c side of the second metal member 20. Further, the inner corner U is formed by the first horizontal plate 12 of the first metal member 10 and the second horizontal plate 23 of the second metal member 20.

Since the corner 24 on the tip 21d side of the second metal member 20 is formed with a curved surface curved in an arc shape, the corner 24 on the tip 21d side of the second metal member 20 and the first horizontal plate 12 A substantially V-shaped gap S1 is formed between the surface and the surface 12a. Further, since the corner portion 14 on the base end portion 11c side of the first metal member 10 and the corner portion 24 on the base end portion 21c side of the second metal member 20 are curved in opposite directions, these corner portions 14 A substantially V-shaped gap S2 is formed between the surface and the corner portion 24.

As shown in FIGS. 3 and 4, the temporary joining step is a step of temporarily joining the butt portion J1 and the butt portion J2 using the rotation tool F (temporary joining rotation tool).
The rotary tool F is made of, for example, tool steel. The rotation tool F includes a connecting portion F1 and a stirring pin F2. The connecting portion F1 is a portion connected to the rotating shaft of the friction stirrer. The connecting portion F1 has a columnar shape.

The stirring pin F2 extends from the connecting portion F1 and is coaxial with the connecting portion F1. The stirring pin F2 is tapered as it is separated from the connecting portion F1. A spiral groove is engraved on the outer peripheral surface of the stirring pin F2. In the present embodiment, in order to rotate the rotation tool F clockwise, the spiral groove is formed counterclockwise from the base end portion to the tip end portion.
When the rotation tool F is rotated counterclockwise, it is preferable to form the spiral groove clockwise from the base end to the tip end.

By setting the spiral groove in this way, the metal plastically fluidized during friction stir welding is guided to the tip end side of the stirring pin F2 by the spiral groove. As a result, the amount of metal that overflows to the outside of the metal member to be joined (first metal member 10, second metal member 20, auxiliary member 30 and auxiliary member 40 described later) can be reduced. The spiral groove may be omitted.

In the first temporary joining step (temporary joining step) illustrated in FIG. 3, only the stirring pin F2 of the rotated rotation tool F is brought into contact with the butt portion J1 to perform spot temporary attachment. In this step, only the stirring pin F2 is shallowly pushed into the butt portion J1 at a predetermined interval. Then, only the stirring pin F2 is brought into contact with the first metal member 10 and the second metal member 20. As a result, a plasticized region W0 is formed in the pushing mark of the stirring pin F2.
The rotation tool F is preferably attached to an arm robot (not shown) having a rotation driving means such as a spindle unit at its tip. As a result, the rotation center axis of the rotation tool F can be easily tilted.

In the second temporary joining step (temporary joining step) illustrated in FIG. 4, the first metal member 10 and the second metal member 20 in the state of FIG. 3 are relatively turned upside down, and the butt portion J2 is formed by the rotation tool F. Temporarily attach spots. In the second temporary joining step, as in the first temporary joining step shown in FIG. 3, the plasticized region W0 is formed by shallowly pushing only the stirring pin F2 into the butt portion J2 at a predetermined interval. To.

The first auxiliary member arranging step (auxiliary member arranging step) is performed after the first temporary joining step (temporary joining step). The first auxiliary member arranging step shown in FIGS. 5 and 6 is a step of arranging the auxiliary member 30 on the first metal member 10 and the second metal member 20 so as to cover the inner corner U.
First, the auxiliary member 30 is a metal plate-shaped member. The auxiliary member 30 is not particularly limited as long as it is made of a metal capable of friction stir welding, but in the present embodiment, it is made of the same material as the first metal member 10 and the second metal member 20.

The plate thickness of the auxiliary member 30 is appropriately set so that the plasticized region W described later does not run short of metal and the gap S1 of the butt portion J1 is filled with metal after the first main joining step (main joining step) described later. .. In the present embodiment, the plate thickness of the auxiliary member 30 is set to be thinner than the plate thickness of the first metal member 10 and the second metal member 20.

Further, the auxiliary member 30 used in the present embodiment is a long metal member having an L-shaped shaft cross section. As a result, as shown in FIGS. 5 and 6, the inner corner U (butting portion J1) composed of the first horizontal plate 12 of the first metal member 10 and the second horizontal plate 23 of the second metal member 20 is covered. As described above, the auxiliary member 30 can be arranged on the first metal member 10 and the second metal member 20. That is, the back surface 30a of the auxiliary member 30 comes into surface contact with the surface 12a of the first horizontal plate 12 of the first metal member 10 and the surface 23a of the second horizontal plate 23 of the second metal member 20, respectively. As a result, the inner corner U is covered with the auxiliary member 30. In the first embodiment, the auxiliary member 30 has an L-shaped shaft cross section, but may have another shape. For example, two rectangular and flat auxiliary members are prepared, one is brought into surface contact with the surface 12a of the first horizontal plate 12 of the first metal member 10, and the other is the second metal member 20. The inner corner U (butting portion J1) may be covered with the two auxiliary members 30 by making surface contact with the surface 23a of the horizontal plate 23.
The first metal member 10, the second metal member 20, and the auxiliary member 30 are immovably restrained on the gantry (not shown) by a jig (not shown).

As shown in FIGS. 7 and 8, the first main joining step (main joining step) is a step of performing friction stir welding to the butt portion J1 using the rotation tool F (rotation tool for main joining). Here, it is preferable that the main rotation tool for joining is shared with the above-mentioned rotation tool for temporary joining. That is, in the present embodiment, the same rotation tool F is used for the main joint rotation tool and the temporary joint rotation tool. In the first main joining step, as shown in FIG. 8, the rotating tool F rotated clockwise is inserted from the surface 30b of the auxiliary member 30, and the insertion depth of the stirring pin F2 is set so as to reach the butt portion J1. ..

A spiral groove is engraved on the outer peripheral surface of the stirring pin F2. In the present embodiment, in order to rotate the rotation tool F clockwise, the spiral groove is formed counterclockwise from the base end portion to the tip end portion. By setting the spiral groove in this way, the metal plastically fluidized during friction stir welding is guided to the tip end side of the stirring pin F2 by the spiral groove. As a result, the amount of metal that overflows to the outside of the first metal member 10, the second metal member 20, and the auxiliary member 30, which are the metal members to be joined, can be reduced. The rotation tool F is attached to, for example, an arm robot having a rotation driving means such as a spindle unit at its tip. By attaching to the arm robot, the inclination angle of the rotation center axis of the rotation tool F can be easily changed. As a result, friction stir welding is performed with the rotary tool F tilted toward the second metal member 20 so that the connecting portion F1 does not interfere with the surface 12a of the first horizontal plate 12 of the first metal member 10. In the present embodiment, friction stir welding is performed by tilting the axial direction of the stirring pin F2 by approximately 45 ° with respect to the surface 12a of the first horizontal plate 12 and the surface 23a of the second horizontal plate 23, respectively.

In the first main joining step, only the stirring pin F2 is brought into contact with the auxiliary member 30, the first metal member 10 and the second metal member 20, and friction stir welding is performed with the base end side of the stirring pin F2 exposed.
As shown in FIG. 7, in the first main joining step, the stirring pin F2 is inserted into the start position Sp set at the portion where the first metal member 10 and the second metal member 20 and the auxiliary member 30 abut, and the abutting portion is formed. The rotation tool F is moved in the direction of the arrow along J1. The movement direction of the rotation tool F may be opposite to that in FIG. 7. As a result, the auxiliary member 30, the first metal member 10, and the second metal member 20 are friction-stir welded in the butt portion J1. A linear plasticized region W is formed in the movement locus of the rotation tool F.
After the first main joining step, as shown in FIG. 9, the auxiliary member 30 is divided into the first metal member 10 side and the second metal member 20 side by the plasticized region W. In addition, burrs V and V are formed at the ends of the divided auxiliary members 30 and 30.

The first removal step (removal step) is a step of removing the auxiliary member 30 from the first metal member 10 and the second metal member 20. In the first removing step, as shown in FIG. 9, the end portion of the auxiliary member 30 is turned up in the direction of the arrow and cut so as to be bent with the plasticized region W as a boundary. A cutting tool or the like may be used for the removal step, but in the present embodiment, the removal is performed manually. Since the burr V is formed on the auxiliary member 30, the burr V is removed together with the auxiliary member 30.

The second auxiliary member arranging step (auxiliary member arranging step) is performed after the second temporary joining step (temporary joining step). The second auxiliary member arranging step shown in FIGS. 10 and 11 is a step of arranging the auxiliary member 40 on the first metal member 10 and the second metal member 20 so as to cover the butt portion J2.
First, the auxiliary member 40 is a metal plate-shaped member. The auxiliary member 40 is not particularly limited as long as it is made of a metal capable of friction stir welding, but in the present embodiment, it is made of the same material as the first metal member 10 and the second metal member 20.
The plate thickness of the auxiliary member 40 is appropriately set so that the plasticized region W described later does not become short of metal and the gap S2 of the butt portion J2 is filled with metal after the second main joining step (main joining step) described later. .. In the present embodiment, the plate thickness of the auxiliary member 40 is set to be thinner than the plate thickness of the first metal member 10 and the second metal member 20.

Further, the auxiliary member 40 used in the present embodiment is a long flat metal member. Then, as shown in FIGS. 10 and 11, the first metal member 10 covers the butt portion J2 composed of the vertical plate 11 of the first metal member 10 and the first horizontal plate 22 of the second metal member 20. And the auxiliary member 40 is arranged on the second metal member 20. As a result, the back surface 40a of the auxiliary member 40 comes into surface contact with the other side surface 11b of the vertical plate 11 of the first metal member 10 and the surface 22a of the first horizontal plate 22 of the second metal member 20. Therefore, the butt portion J2 is covered with the auxiliary member 40. In the first embodiment, the auxiliary member 40 has a flat plate shape, but may have another shape. The first metal member 10, the second metal member 20, and the auxiliary member 40 are immovably restrained on the gantry (not shown) by a jig (not shown).

As shown in FIGS. 12 and 13, the second main joining step (main joining step) is a step of performing friction stir welding to the butt portion J2 using the rotation tool F (rotation tool for main joining). Also in the second main joining step, it is preferable that the main joining rotation tool is shared with the temporary joining rotation tool. That is, in the present embodiment, the same rotation tool F is used for the main joint rotation tool and the temporary joint rotation tool. In the second main joining step, as shown in FIG. 12, the rotating tool F rotated clockwise is inserted from the surface 40b of the auxiliary member 40, and as shown in FIG. 13, the stirring pin F2 reaches the butt portion J2. Set the insertion depth of.

A spiral groove is engraved on the outer peripheral surface of the stirring pin F2. As a result, the amount of metal that overflows to the outside of the first metal member 10, the second metal member 20, and the auxiliary member 40, which are the metal members to be joined, can be reduced as in the first main joining step. Further, in the second joining step, the axial direction of the stirring pin F2 is made substantially perpendicular to the other side surface 11b of the vertical plate 11 and the surface 22a of the first horizontal plate 22 by an arm robot provided with a spindle unit or the like. Friction stir welding is performed.
Also in the second main joining step, only the stirring pin F2 is brought into contact with the auxiliary member 40, the first metal member 10 and the second metal member 20, and friction stir welding is performed with the base end side of the stirring pin F2 exposed. ..

As shown in FIG. 12, in the second joining step, the stirring pin F2 is inserted into the start position Sp set at the portion where the first metal member 10 and the second metal member 20 and the auxiliary member 40 come into contact with each other, and the abutting portion is formed. Move the rotation tool F in the direction of the arrow along J2. The movement direction of the rotation tool F may be opposite to that in FIG. As a result, the auxiliary member 40, the first metal member 10, and the second metal member 20 are friction-stir welded in the butt portion J2. A linear plasticized region W is formed in the movement locus of the rotation tool F.
After the second main joining step, as shown in FIG. 14, the auxiliary member 40 is divided into the first metal member 10 side and the second metal member 20 side by the plasticized region W. In addition, burrs V and V are formed at the ends of the divided auxiliary members 40 and 40.

The second removal step (removal step) is a step of removing the auxiliary member 40 from the first metal member 10 and the second metal member 20, as shown in FIG. In the second removing step, as shown in FIG. 14, the end portion of the auxiliary member 40 is turned up in the direction of the arrow and cut so as to be bent with the plasticized region W as a boundary. A cutting tool or the like may be used for the removal step, but in the present embodiment, the removal is performed manually. Since the burr V is formed on the auxiliary member 30, the burr V is removed together with the auxiliary member 30.

According to the joining method according to the first embodiment described above, the first metal member 10 and the second metal member 20 are joined, and as shown in FIGS. 7 and 12, the first metal member 10 and the second metal member 10 and the second metal member 20 are joined. By simultaneously friction stir welding the auxiliary member 30 and the auxiliary member 40 in addition to the metal member 20, it is possible to prevent a metal shortage in the joint portion (plasticized region W).

Further, as shown in FIGS. 7 and 12, friction stir welding is performed in a state where only the stirring pin F2 of the rotating tool F is in contact with the auxiliary member 30 (or auxiliary member 40), the first metal member 10 and the second metal member 20. By performing the joining, the load acting on the friction stir welding device can be reduced.
Further, in the joining method according to the first embodiment, in the main joining step and the temporary joining step, only the stirring pin F2 of the rotating tool F is brought into contact with the metal member to perform frictional stirring, so that the amount of heat input can be reduced. It is possible to reduce the thermal strain of the first metal member 10 and the second metal member 20.

Moreover, in the joining method according to the first embodiment, the auxiliary member 30 or the auxiliary member 40 is arranged in the butt portion J1 and the butt portion J2, and the auxiliary member 30 (or the auxiliary member 40), the first metal member 10 and the second metal are arranged. Since the members 20 are simultaneously friction-stir welded, the gap S1 and the gap S2 (see FIGS. 6 and 11) can be filled with the plastically fluidized metal.
Further, in the joining method according to the first embodiment, burrs V and V are formed on the auxiliary member 30 by the main joining step. As shown in FIGS. 9 and 14, the burr V is formed on the auxiliary member 30 in the removing step. You can get rid of it. Thereby, the step of removing the burr V can be easily performed.
Further, in the joining method according to the first embodiment, since the temporary joining step is performed, it is possible to prevent the butt portions J1 and the butt portion J2 from opening when the main joining step is performed.

Further, in the joining method according to the first embodiment, as shown in FIGS. 3 and 4, the spot temporary attachment of the butt portion J1 and the butt portion J2 is performed in a state where only the stirring pin F2 of the rotating tool F is in contact with the metal member. By performing the above, the load acting on the friction stirrer can be reduced. Further, the process time can be shortened as compared with the case where the butt portion J1 and the butt portion J2 are temporarily joined to the entire length as in the conventional case.
Further, in the first embodiment, the rotation tool F (temporary joining rotation tool) that performs the temporary joining process and the rotation tool F (main joining rotation tool) that performs the main joining process use the same rotation tool. .. As a result, it is not necessary to replace the rotation tool in each process, so that work efficiency can be improved.

Although the first embodiment of the present invention has been described above, the design can be appropriately changed within a range not contrary to the gist of the present invention.
For example, a rotation tool provided with a shoulder portion and a stirring pin may be used for the rotation tool for temporary joining or the rotation tool for main joining. Further, different rotation tools may be used between the temporary joining step and the main joining step.
Further, in the first embodiment, the corner portion 14 of the first metal member 10 and the corner portion 24 of the second metal member 20 are rounded, and a gap S1 and a gap S2 are provided in the butt portion J1 and the butt portion J2, respectively. Although it is configured, it may be configured so that there is no such gap.

Further, in the first temporary joining step of the first embodiment, as shown in FIG. 3, the rotating tool F is used to temporarily join the inner corner U (butting portion J2), which is shown in FIG. As described above, the inner corner U (butting portion J2) may be temporarily joined by welding. At this time, the type of welding is not particularly limited, and for example, arc welding such as MIG welding (Metal Inert Gas welding) and TIG welding (Tungsten Inert Gas welding) or laser welding can be performed. Then, while the welding torch H is brought close to the inner corner U, spot temporary attachment is performed at a predetermined interval. In this way, welding marks W2 are formed in the portion where the spot is temporarily attached.

Further, as shown in FIG. 16, in the second temporary joining step as well as the modified example of the first temporary joining step, the butt portion J2 may be temporarily joined by welding. In this case as well, the type of welding is not particularly limited. Then, while bringing the welding torch H close to the butt portion J2, spot temporary attachment is performed at a predetermined interval.

As described above, in the temporary joining step, as shown in FIGS. 15 and 16, when spot temporary attachment of the inner corner U (butting portion J1) and butt portion J2 is performed by welding, the temporary attachment is performed by friction stirring. The load acting on the friction stirr can be reduced as compared with the case of doing so. Further, the process time can be shortened as compared with the case where temporary joining is performed on the entire lengths of the inner corner U (butting portion J1) and the butt portion J2 as in the conventional case. The first metal member 10 and the second metal member 20 may be metal members having at least ends having a U-shaped cross section.

[Second Embodiment]
The joining method according to the second embodiment of the present invention will be described in detail. In the following description, the same reference numerals will be used for the same members and the like as in the first embodiment, and detailed description thereof will be omitted. Also in the second embodiment, the first metal member and the second metal member, which are two metal members having a U-shaped cross section, are joined. Further, also in the joining method according to the second embodiment, the butt step, the temporary joining step, the auxiliary member arranging step, the main joining step, and the removing step are performed. Of these, the butt step and the temporary joining step are the same as those in the first embodiment, and thus the description thereof will be omitted.

After the temporary joining step, the first auxiliary member arranging step (auxiliary member arranging step) is performed. As shown in FIG. 17, the first auxiliary member arranging step is a step of arranging the auxiliary member 50 on the first metal member 10 and the second metal member 20 so as to cover the butt portion J1.
The auxiliary member 50 is a flat metal member. Similar to the first embodiment, the auxiliary member 50 is not particularly limited as long as it is a metal capable of friction stir welding, but in this embodiment as well, the auxiliary member 50 is made of the same material as the first metal member 10 and the second metal member 20.

The plate thickness of the auxiliary member 50 is appropriately set so that the plasticized region W described later does not run out of metal and the gap S1 of the butt portion J1 is filled with metal after the first main joining step described later. Also in the second embodiment, the plate thickness of the auxiliary member 50 is set to be thinner than the plate thickness of the first metal member 10 and the second metal member 20.
In the method of arranging the auxiliary member 50, the back surface 50a of the auxiliary member 50 is brought into surface contact with the second horizontal plate 23 of the second metal member 20 so as to cover the butt portion J1, and the first horizontal plate of the first metal member 10 is arranged. The end surface 50b of the auxiliary member 50 is abutted against the surface 12a of 12.
Further, the first metal member 10, the second metal member 20, and the auxiliary member 50 are immovably restrained by a jig (not shown). In the present embodiment, the auxiliary member 50 has a plate shape, but may have another shape.

As shown in FIGS. 18 and 19, the first main joining step (main joining step) is a step of performing friction stir welding to the butt portion J1 using the rotation tool F (rotation tool for main joining). Here, also in the present embodiment, it is preferable that the main joint rotation tool is shared with the temporary joint rotation tool. That is, in the present embodiment, the same rotation tool F is used for the main joint rotation tool and the temporary joint rotation tool.

A spiral groove is engraved on the outer peripheral surface of the stirring pin F2. As a result, as in the first embodiment, the amount of metal that overflows to the outside of the metal member to be joined (first metal member 10, second metal member 20, and auxiliary member 50) can be reduced. Further, by attaching the rotation tool F to an arm robot provided with a spindle unit or the like, the inclination angle of the rotation center axis of the rotation tool F can be easily changed.

In the friction stir welding of the butt portion J1, the start position Sp on the surface 50c of the auxiliary member 50 set at the portion where the surface 12a of the first horizontal plate 12 of the first metal member 10 and the end surface 50b of the auxiliary member 50 abut is set. The stirring pin F2 rotated clockwise is inserted, and the rotation tool F is relatively moved along the butt portion J1. That is, with the base end side of the stirring pin F2 exposed, only the stirring pin F2 is brought into contact with the first metal member 10, the second metal member 20, and the auxiliary member 50 to perform friction stirring. Further, the traveling direction of the rotation tool F is set so that the auxiliary member 50 is located on the right side of the rotation tool F. In the case of FIG. 18, the rotation tool F is moved from the front side to the back side of the figure (indicated by an arrow). As a result, a linear plasticized region W is formed in the movement locus of the rotation tool F.

As shown in FIGS. 18 and 19, in the first main joining step, the rotating tool F is used as the second metal member 20 so that the connecting portion F1 does not interfere with the surface 12a of the first horizontal plate 12 of the first metal member 10. Friction stir welding is performed in a state of being inclined. The insertion angle and insertion depth of the stirring pin F2 may be appropriately set so that the first metal member 10 and the second metal member 20 can be joined. In this embodiment, the central axis of the rotation tool F is tilted by approximately 45 ° with respect to the surface 12a of the first horizontal plate 12.

In the first main joining step, it is desirable to set the joining conditions so that burrs are generated on the auxiliary member 50. The position where burrs occur depends on the joining conditions. The joining conditions include the rotation speed, rotation direction, movement speed (feed speed), traveling direction of the rotation tool F, inclination angle (taper angle) of the stirring pin F2, and metal members to be joined (first metal member 10, second metal member 10, second). It is determined by each element such as the material of the metal member 20 and the auxiliary member 50), the thickness of the metal member to be joined, and the combination of these elements.

For example, when the rotation speed of the rotation tool F is slow, the shearing side (advancing side: the side where the movement speed of the rotation tool is subtracted from the tangential velocity on the outer circumference of the rotation tool) On the side where the moving speed of the rotating tool is added to the tangential velocity on the outer circumference), the temperature of the plastic fluid material tends to rise, so that burrs tend to occur more on the shear side outside the plasticized region. On the other hand, for example, when the rotation speed of the rotation tool F is high, the temperature of the plastic fluid material rises on the shear side, but the high rotation speed tends to cause more burrs on the flow side outside the plasticized region. is there.

In the present embodiment, since the rotation speed of the rotation tool F is set to be high, in the friction stir welding of the butt portion J1, a large amount of burrs V tend to be generated in the auxiliary member 50 on the flow side outside the plasticization region W. There is (see FIG. 19). The joining conditions of the rotation tool F and the arrangement position of the auxiliary member 50 are not limited to those described here, and may be set as appropriate.

In this way, if the joining conditions are set so that the side where the burr V is generated or the side where the burr V is generated abundantly becomes the auxiliary member 50, the burr V is integrated in the auxiliary member 50 as shown in FIGS. 18 and 19. can do. Therefore, it is preferable because the first removal step described later can be easily performed. Further, by setting the rotation speed of the rotation tool F to be high, the movement speed (feed speed) of the rotation tool F can be increased. As a result, the joining cycle can be shortened.

After the first main joining step, the first removing step (removing step) is performed. The first removing step is a step of removing the auxiliary member 50 from the second metal member 20. As shown in FIG. 20, in the removing step of the present embodiment, the end portion of the auxiliary member 50 is turned up in the direction of the arrow and cut so as to be bent with the plasticized region W as a boundary. A cutting tool or the like may be used for the removal step, but in the present embodiment, the removal is performed manually. Since the burr V is formed on the auxiliary member 50, the burr V is removed together with the auxiliary member 50.
Also in this embodiment, the second auxiliary member arranging step, the second main joining step, and the second removing step are performed, but since the contents of these steps are the same as those in the first embodiment, the description thereof will be omitted.

According to the joining method of the present embodiment described above, the first metal member 10 and the second metal member 20 are joined, and in addition to the first metal member 10 and the second metal member 20, the auxiliary member 50 is also formed. By performing friction stir welding at the same time, it is possible to prevent metal shortage at the joint.

Further, since the burr V generated by friction stir welding can be removed from the metal member together with the auxiliary member 50, the step of removing the burr V becomes easy. Further, in this joining step, since friction stir welding is performed with only the stirring pin F2 in contact with the metal member to be joined, the load acting on the friction stir device can be reduced.
Further, by using the same rotation tool F for the temporary joining rotation tool and the main joining rotation tool, it is not necessary to replace the rotation tool F between the temporary joining process and the main joining process, so that the work efficiency can be improved. Can be done.
In addition, in the same steps as in the first embodiment, the same effects as in the first embodiment can be obtained.
Further, the modified example of the temporary joining step or the like described in the first embodiment can be applied to this embodiment as well.

[Third Embodiment]
The third embodiment also performs a butt step, a temporary joining step, an auxiliary member arranging step, a main joining step, and a removing step. Since the butt step and the temporary joining step are the same as those in the first embodiment and the removing step is the same as that in the second embodiment, detailed description thereof will be omitted. Further, since the second auxiliary member arranging step and the second joining step are the same as those in the first embodiment, the description thereof will be omitted. Hereinafter, the first auxiliary member arranging step and the first main joining step will be described. Further, the same reference numerals as those of the first embodiment or the second embodiment are used for the members and the like similar to those of the first embodiment or the second embodiment, and detailed description thereof will be omitted.

First, as shown in FIG. 21, in the first auxiliary member arranging step (auxiliary member arranging step), the surface of the first horizontal plate 12 of the first metal member 10 is covered so as to cover the inner corner U (butting portion J1). The back surface 50a of the auxiliary member 50 is brought into surface contact with 12a, and the end surface 50b of the auxiliary member 50 is abutted against the abutting portion J1.

Next, the first main joining step (main joining step) will be described. As shown in FIG. 22, in the friction stir welding of the butt portion J1, the start position Sp on the surface 50c of the auxiliary member 50 set at the portion where the surface 12a of the first metal member 10 and the end surface 50b of the auxiliary member 50 abut is set. , The stirring pin F2 rotated clockwise at high speed is inserted, and the rotation tool (rotation tool for main joining) F is relatively moved along the butt portion J1. That is, with the base end side of the stirring pin F2 exposed, only the stirring pin F2 is brought into contact with the first metal member 10, the second metal member 20, and the auxiliary member 50 to perform friction stirring. Further, the traveling direction of the rotation tool F is set so that the auxiliary member 30 is located on the right side of the rotation tool F. In the case of FIG. 22, the rotation tool F is moved from the back side of the figure toward the front side (indicated by an arrow). As a result, a linear plasticized region W is formed in the movement locus of the rotation tool F. Further, the auxiliary member 50 side of the rotation tool F is the flow side, and the burr V is mainly generated in the auxiliary member 50.

According to the joining method of the present embodiment described above, the first metal member 10 and the second metal member 20 are joined, and in addition to the first metal member 10 and the second metal member 20, the auxiliary member 50 is also formed. By performing friction stir welding at the same time, it is possible to prevent metal shortage at the joint.
In addition, according to the third embodiment, the same effect as that of the second embodiment can be obtained.

10 First metal member 11 Vertical plate 11a One side surface 11b The other side surface 11c Base end 11d Tip 12 First horizontal plate 12a Surface 13 Second horizontal plate 20 Second metal member 21 Vertical plate 21a One side surface 21b The other Side surface 21c Base end 21d Tip 22 First horizontal plate 23 Second horizontal plate 30 Auxiliary member 30b Surface 40 Auxiliary member 50 Auxiliary member 50c Surface F Rotation tool (rotation tool for temporary joining, rotation tool for main joining)
F2 Stirring pin J1 Butt part J2 Butt part U Inner corner V Burr

Claims (10)

This is a joining method in which a first metal member and a second metal member are joined by friction stir using a rotary tool for main joining equipped with a stirring pin.
At least the ends of the first metal member and the second metal member both have a first horizontal plate protruding from a base end portion of one side surface of the vertical plate and a tip portion of one side surface of the vertical plate. The second horizontal plate is formed with a protruding U-shaped cross section.
The other side surface of the vertical plate in the first metal member and the surface of the first horizontal plate in the second metal member are flush with each other, and the surface of the first horizontal plate in the first metal member A butt step of forming a butt portion by abutting the other side surface of the vertical plate in the second metal member.
Auxiliary members for arranging auxiliary members on the first metal member and the second metal member so as to cover an inner corner composed of the first horizontal plate of the first metal member and the second horizontal plate of the second metal member. Member placement process and
With the stirring pin inserted from the surface side of the auxiliary member and only the stirring pin in contact with the auxiliary member, the first metal member and the second metal member, the main joining is performed along the butt portion. The main joining step of performing friction stir welding of the auxiliary member, the first metal member, and the second metal member by relatively moving the rotary tool for use.
A joining method comprising a removing step of removing the auxiliary member on which burrs are formed from the first metal member and the second metal member. This is a joining method in which a first metal member and a second metal member are joined by friction stir using a rotary tool for main joining equipped with a stirring pin.
At least the ends of the first metal member and the second metal member both have a first horizontal plate protruding from a base end portion of one side surface of the vertical plate and a tip portion of one side surface of the vertical plate. The second horizontal plate is formed with a protruding U-shaped cross section.
The other side surface of the vertical plate in the first metal member and the surface of the first horizontal plate in the second metal member are flush with each other, and the surface of the first horizontal plate in the first metal member A butt step of forming a butt portion by abutting the other side surface of the vertical plate in the second metal member.
Auxiliary member for arranging an auxiliary member on the first metal member or the second metal member so as to cover an inner corner composed of a first horizontal plate of the first metal member and a second horizontal plate of the second metal member. Member placement process and
With the stirring pin inserted from the surface side of the auxiliary member and only the stirring pin in contact with the auxiliary member, the first metal member and the second metal member, the main joining is performed along the butt portion. The main joining step of performing friction stir welding of the auxiliary member, the first metal member, and the second metal member by relatively moving the rotary tool for use.
A joining method comprising a removal step of removing the auxiliary member on which burrs are formed from the first metal member or the second metal member. Claim 1 or claim 2 comprises a temporary joining step of inserting only the stirring pin of the rotary tool for temporary joining into the inner corner and performing friction stir welding at a spot before the auxiliary member arranging step. The joining method described in. The joining method according to claim 3, wherein the temporary joining rotation tool and the main joining rotation tool are the same rotation tool. The joining method according to claim 1 or 2, wherein a temporary joining step of joining the inner corners with spots by welding is included before the auxiliary member arranging step. The joining method according to claim 5, wherein the welding is MIG welding, TIG welding or laser welding. Prior to the auxiliary member arranging step, a temporary joining step of inserting only the stirring pin of the temporary joining rotary tool into the butt portion on the base end side of the vertical plate in the second metal member and performing friction stir welding at a spot. The joining method according to claim 1 or 2, wherein the joining method comprises. The joining method according to claim 7, wherein the temporary joining rotation tool and the main joining rotation tool are the same rotation tool. Claim 1 or claim 2 comprises a temporary joining step of joining the butt portion on the base end side of the vertical plate of the second metal member with a spot by welding before the auxiliary member arranging step. The joining method described in. The joining method according to claim 9, wherein the welding is MIG welding, TIG welding or laser welding.

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