JP6766415B2 - Joining method - Google Patents

Description

The present invention relates to a method of joining metal members to each other.

Patent Document 1 discloses a joining method in which a first metal member and a second metal member are overlapped and joined. In the joining method, a polymerization step of superimposing the back surface of the first metal member and the front surface of the second metal member to form a polymerized portion and a friction stir welding of the polymerized portion by pushing a rotating tool from the surface of the first metal member. A friction stir step is performed.

Japanese Patent No. 4126966

In the conventional joining method, the lower end surface of the shoulder portion of the rotary tool is pushed into the surface of the first metal member to perform the friction stir welding step, so that burrs are generated on the surface of the first metal member. Therefore, a deburring step for removing burrs must be performed. Further, since the lower end surface of the shoulder portion of the rotary tool is pushed into the surface of the first metal member to perform the friction stir step, there is a problem that the load applied to the friction stir device becomes large.

From this point of view, the present invention is characterized by providing a joining method capable of preventing burrs from being generated on the surface of the first metal member and reducing the load applied to the friction stir welding device. To do.

In order to solve such a problem, the present invention comprises a polymerization step of superimposing the back surface of the first metal member having a concave groove on the front surface and the front surface of the second metal member to form a polymerized portion, and the first. It includes a friction stir step of inserting a stirring pin of a rotating tool into the concave groove from the surface side of the metal member, moving the rotating tool relative to the concave groove, and friction stir welding the polymerized portion. The rotary tool has a columnar shaped shoulder portion and the stirring pin hanging from the shoulder portion, and the diameter of the shoulder portion is set to be slightly smaller than the width of the groove, and the friction stir welding step is performed. The stirring pin is brought into contact with only the first metal member, or the first metal member and the second metal member to cause plastic fluidization, and the shoulder portion of the rotating tool is inserted into the recessed groove to form the shoulder portion. With a slight gap between the outer peripheral surface of the surface and the side wall of the concave groove, and the shoulder portion separated from the bottom surface of the concave groove, burrs generated from the first metal member are separated from the shoulder portion. It is characterized in that the polymerized portion is friction-stir welded while being pressed by.
Further, the present invention comprises a polymerization step of superimposing the back surface of the first metal member having a groove on the surface and the surface of the second metal member to form a polymerized portion, and from the front surface side of the first metal member. A friction stir step of inserting a stirring pin of a rotating tool into the groove, moving the rotating tool relative to the groove, and friction stir welding the polymerized portion is included, and the groove is closed. The rotating tool has a columnar shoulder portion and a stirring pin hanging from the shoulder portion, and the diameter of the shoulder portion is set to be slightly smaller than the width of the concave groove, and the friction is set. In the stirring step, the stirring pin is brought into contact with only the first metal member, or the first metal member and the second metal member to cause plastic fluidization, and the shoulder portion of the rotating tool is inserted into the recessed groove. Then, the outer peripheral surface of the shoulder portion and the side wall of the concave groove are separated from each other with a slight gap, and the shoulder portion is separated from the bottom surface of the concave groove, and is generated from the first metal member. It is characterized in that the polymerized portion is friction-stir welded while the burr is pressed by the shoulder portion. Further, in the friction stir welding step, it is preferable to rotate the rotating tool around the concave groove to perform friction stir welding of the polymerized portions.
Further, in the present invention, a spiral groove is formed on the outer peripheral surface of the stirring pin, and when the spiral groove is formed counterclockwise from the base end to the tip end, the rotation tool is rotated clockwise. When the spiral groove is formed clockwise from the base end to the tip end, it is preferable to rotate the rotation tool counterclockwise.
Further, in the present invention, it is preferable that the stirring pin hangs down from the shoulder portion and is tapered.

According to such a joining method, a narrow space is formed on the bottom surface of the concave groove, both side walls of the concave groove, and the lower end surface of the shoulder portion, so that burrs are prevented from scattering and burrs are deposited on the bottom surface of the concave groove. be able to. As a result, it is possible to prevent burrs from being generated on the surface of the first metal member. Further, since the shoulder portion is not pushed into the bottom surface of the concave groove, the load applied to the friction stir welding device can be reduced.

According to the joining method according to the present invention, it is possible to prevent burrs from being generated on the surface of the first metal member and to reduce the load applied to the friction stir welding device.

It is a perspective view which shows the polymerization process of the bonding method which concerns on 1st Embodiment of this invention. It is a perspective view which shows the friction stir step of the joining method which concerns on 1st Embodiment. It is sectional drawing which shows the friction stir step of the joining method which concerns on 1st Embodiment. It is a perspective view which shows the polymerization process of the joining method which concerns on 2nd Embodiment. It is a top view which shows the friction stir step of the joining method which concerns on 2nd Embodiment.

[First Embodiment]
The joining method according to the first embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, in the joining method according to the first embodiment, the first metal member 1 and the second metal member 2 are overlapped and joined. The joining method according to the first embodiment includes a polymerization step, a tab material arranging step, and a friction stir welding step. The "front surface" in the description means the surface opposite to the "back surface".

The first metal member 1 is a plate-shaped metal member. The material of the first metal member 1 is appropriately selected from frictionally agitable metals such as aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, magnesium and magnesium alloy. A concave groove 3 having a rectangular cross section is formed on the surface 1b of the first metal member 1. The concave groove 3 extends in the extension direction of the first metal member 1. The concave groove 3 is composed of a bottom surface 3a and side walls 3b and 3b rising from the bottom surface 3a.

The second metal member 2 is a plate-shaped metal member. The material of the second metal member 2 may be appropriately selected from the above-mentioned metals capable of friction stir welding, but it is preferably a material equivalent to that of the first metal member 1. The second metal member 2 has the same shape as the first metal member 1, but may have a different shape. Further, the shapes of the first metal member 1 and the second metal member 2 both have a plate shape (rectangular parallelepiped) in the present embodiment, but may be a polygonal shape other than a plan view, and a circular or elliptical shape in a plan view. It may be.

As shown in FIG. 1, the polymerization step is a step of superimposing the back surface 1c of the first metal member 1 and the front surface 2b of the second metal member 2. The overlapping portion J is formed by superimposing the back surface 1c of the first metal member 1 and the front surface 2b of the second metal member 2.

As shown in FIG. 1, the tab material arranging step is a step of arranging the tab materials T, T. The tab material T exhibits a rectangular parallelepiped. The tab material T is temporarily joined to the end faces 1a and 2a of the first metal member 1 and the second metal member 2 by welding so that the surface Ta of the tab material T and the bottom surface 3a of the concave groove 3 are flush with each other. ..

As shown in FIGS. 1 and 2, the friction stir welding step is a step of inserting the shoulder portion G1 of the rotary tool G into the recessed groove 3 and friction stir welding the polymerization portion J. The rotation tool G is composed of a columnar shoulder portion G1 and a stirring pin G2 that hangs down from the lower end surface G1a of the shoulder portion G1. The diameter of the shoulder portion G1 is formed to be slightly smaller than the width of the concave groove 3. The diameter of the shoulder portion G1 may be set so that the outer peripheral surface of the shoulder portion G1 and the side walls 3b and 3b of the recessed groove 3 are in contact with each other, but when the friction stir welding step is performed, the diameter of the shoulder portion G1 is contacted with the outer peripheral surface of the shoulder portion G1. It is preferable that the side walls 3b and 3b of the concave groove 3 have a size that allows relative movement with a slight gap.

The stirring pin G2 is tapered. A spiral groove is formed on the outer peripheral surface of the stirring pin G2. In the present embodiment, in order to rotate the rotation tool G clockwise, the spiral groove of the stirring pin G2 is formed counterclockwise from the base end to the tip end. In other words, the spiral groove is formed counterclockwise when viewed from above when the spiral groove is traced from the base end to the tip end.

When the rotation tool G is rotated counterclockwise, it is preferable to form the spiral groove clockwise from the base end to the tip end. In other words, the spiral groove in this case is formed clockwise when viewed from above when the spiral groove is traced from the base end to the tip end. By setting the spiral groove in this way, the metal plastically fluidized during the friction stir step is guided to the tip side of the stirring pin G2 by the spiral groove. As a result, the amount of metal overflowing from the bottom surface 3a of the concave groove 3 can be reduced.

In the friction stir step, the stirring pin G2 of the rotary tool G is inserted into the start position Sp1 set on the surface Ta of one tab material T, and the polymerization unit reaches the end position Ep1 set on the surface Ta of the other tab material T. The rotation tool G is relatively moved along J (recessed groove 3). The insertion depth of the rotation tool G may be appropriately set, but in the present embodiment, as shown in FIG. 3, the stirring pin G2 reaches the second metal member 2, that is, the first metal member 1 and the first metal member 1. (Ii) Friction stir welding is performed with the metal member 2 and the stirring pin G2 in contact with each other. A plasticized region W is formed in the movement locus of the rotation tool G.

Further, in the friction stir welding step, as shown in FIG. 3, the lower end surface G1a of the shoulder portion G1 is set at a position lower than the surface 1b of the first metal member 1 while being separated from the bottom surface 3a of the concave groove 3. ing. That is, in the friction stir welding step, friction stir welding is performed while pressing the burr V generated by friction stir welding with the lower end surface G1a of the shoulder portion G1. The "state in which the shoulder portion is separated from the bottom surface of the concave groove" in the claims means that the lower end surface G1a of the shoulder portion G1 is separated from the bottom surface 3a of the concave groove 3 before the burr V is generated. Is. Further, in the claims, "while pressing the burr generated from the first metal member with the shoulder portion", the deposited burr V and the lower end surface G1a of the shoulder portion G1 are in contact with each other, and the burr V It means that the surface (upper surface) is pressed by the lower end surface G1a of the shoulder portion G1.

Further, the outer peripheral surface of the shoulder portion G1 and the side walls 3b and 3b of the concave groove 3 are separated from each other with a slight gap. A narrow space is formed by the bottom surface 3a of the concave groove 3, the side walls 3b and 3b of the concave groove 3, and the lower end surface G1a of the shoulder portion G1.

The stirring pin G2 may be set so as not to reach the second metal member 2. That is, in the friction stir step, the insertion depth of the stir pin G2 may be set so that only the first metal member 1 and the stir pin G2 are in contact with each other. In this way, when the tip of the stirring pin G2 is set so as not to reach the second metal member 2, the metal around the overlapping portion J is plastically flowed by the frictional heat between the first metal member 1 and the stirring pin G2. The first metal member 1 and the second metal member 2 are joined together.

A burr V is generated on the bottom surface 3a of the concave groove 3 by the friction stir welding step, but a narrow space (rectangular cross section) composed of the bottom surface 3a of the concave groove 3, the side walls 3b and 3b of the concave groove 3, and the lower end surface G1a of the shoulder portion G1. The burr V is confined in the closed space), and the burr V is deposited on the bottom surface 3a. As shown in FIG. 3, the burr V is housed in the concave groove 3, and the surface (upper surface) of the burr V is pressed by the lower end surface G1a of the shoulder portion G1 to become substantially flat. When the rotation tool G reaches the end position Ep1, the rotation tool G is separated from the tab material T, and the tab materials T and T are cut off.

According to the joining method according to the present embodiment described above, when the friction stir welding step is performed, a narrow space is formed by the bottom surface 3a of the concave groove 3, the side walls 3b and 3b of the concave groove 3, and the lower end surface G1a of the shoulder portion G1. Therefore, it is possible to prevent the burr V from scattering and to deposit the burr V on the bottom surface 3a of the concave groove 3. As a result, it is possible to prevent the burr V from being generated on the surface 1b of the first metal member 1. Therefore, the surface treatment such as the deburring step of the surface 1b of the first metal member 1 can be omitted.

Further, according to the joining method according to the present embodiment, since the shoulder portion G1 is not pushed into the bottom surface 3a of the concave groove 3, the load applied to the friction stir welding device can be reduced. Before performing the friction stir welding step, a temporary joining step of temporarily joining the overlapping portion J from the end face 1a of the first metal member 1 and the end face 2a of the second metal member 2 may be performed. In this case, for example, a small rotation tool for temporary joining is used to temporarily join the polymerized portion J. The temporary joining step may be performed by welding. By performing the temporary joining step, the first metal member 1 and the second metal member 2 are less likely to be misaligned in the friction stir welding step using the rotary tool G, and the work can be performed stably.

[Second Embodiment]
Next, the joining method according to the second embodiment of the present invention will be described. The joining method according to the present embodiment includes a polymerization step and a friction stir welding step. The joining method according to the present embodiment is different from the first embodiment in that the tab material arranging step is omitted and the concave groove 3 is a closed loop. In the joining method according to the second embodiment, the parts different from the first embodiment will be mainly described.

As shown in FIG. 4, the first metal member 1 is a plate-shaped metal member. A closed loop groove 3 is formed on the surface 1b of the first metal member 1. The closed loop means that the groove 3 is closed so as to circulate. The planar shape of the concave groove 3 may be any shape as long as it is closed, but in the present embodiment, it is formed in a rectangular frame shape in a plan view along the peripheral edge of the first metal member 1.

The second metal member 2 is a plate-shaped metal member. The second metal member 2 has the same shape as the first metal member 1, but may have a different shape. Further, the shapes of the first metal member 1 and the second metal member 2 both have a plate shape (rectangular parallelepiped) in the present embodiment, but may be a polygonal shape other than a plan view, and a circular or elliptical shape in a plan view. It may be. Further, a groove or a recess may be formed on the surface 2b of the second metal member 2. The groove or recess is preferably formed so as to be located inside the recess 3 of the first metal member 1.

As shown in FIG. 4, the polymerization step is a step of superimposing the back surface 1c of the first metal member 1 and the front surface 2b of the second metal member 2. The overlapping portion J is formed by superimposing the back surface 1c of the first metal member 1 and the front surface 2b of the second metal member 2.

As shown in FIGS. 4 and 5, the friction stir welding step is a step of inserting the shoulder portion G1 of the rotary tool G into the recessed groove 3 and friction stir welding the polymerization portion J. In the friction stir step, the stirring pin G2 of the rotation tool G is inserted into the start position Sp set in the concave groove 3, and the overlapping portion J is joined along the concave groove 3. A plasticized region W is formed in the movement locus of the rotation tool G. Pressing the insertion depth of the stirring pin G2 and the burr V with the lower end surface G1a of the shoulder portion G1 is equivalent to that of the first embodiment.

When the rotary tool G is made to go around along the concave groove 3, the start end and the end of the plasticized region W are overlapped, and the rotary tool G is separated from the first metal member 1 at the end position Ep set in the concave groove 3. Let me.

According to the joining method according to the present embodiment described above, when the friction stir welding step is performed, a narrow space is formed by the bottom surface 3a of the concave groove 3, the side walls 3b and 3b of the concave groove 3, and the lower end surface G1a of the shoulder portion G1. Therefore, it is possible to prevent the burr V from scattering and to deposit the burr V on the bottom surface 3a of the concave groove 3. As a result, it is possible to prevent the burr V from being generated on the surface 1b of the first metal member 1. Therefore, the surface treatment such as the deburring step of the surface 1b of the first metal member 1 can be omitted. Further, the bonding strength can be increased by performing friction stir welding of the polymerization portion J along the concave groove 3 of the closed loop. In addition, a closed region can be formed inside the concave groove 3 of the closed loop.

Further, according to the joining method according to the present embodiment, since the shoulder portion G1 is not pushed into the bottom surface 3a of the concave groove 3, the load applied to the friction stir welding device can be reduced. Before performing the friction stir welding step, a temporary joining step of temporarily joining the overlapping portion J from the end face 1a of the first metal member 1 and the end face 2a of the second metal member 2 may be performed. Further, in the friction stir welding step, the rotating tool G may not go around along the concave groove 3 of the closed loop (the start end and the end end of the plasticized region W may not overlap).

1 1st metal member 1b front surface 1c back surface 2 2nd metal member 2b front surface 2c back surface 3 concave groove J superimposing part G rotating tool G1 shoulder part G2 stirring pin V burr W plasticized area

Claims (5)

A polymerization step of superimposing the back surface of the first metal member having a groove on the front surface and the front surface of the second metal member to form a polymerization portion.
A friction stir step in which a stirring pin of a rotating tool is inserted into the concave groove from the surface side of the first metal member, the rotating tool is relatively moved along the concave groove, and the polymerized portion is friction stir welded. Including
The rotating tool has a columnar shoulder portion and a stirring pin hanging from the shoulder portion, and the diameter of the shoulder portion is set to be slightly smaller than the width of the concave groove.
In the friction stir step, the stirring pin is brought into contact with only the first metal member, or the first metal member and the second metal member to cause plastic fluidization, and the shoulder portion of the rotating tool is placed in the recessed groove. From the first metal member in a state where the outer peripheral surface of the shoulder portion and the side wall of the concave groove are separated from each other with a slight gap and the shoulder portion is separated from the bottom surface of the concave groove. A joining method characterized in that the polymerized portion is friction-stir welded while the generated burrs are pressed by the shoulder portion. A polymerization step of superimposing the back surface of the first metal member having a groove on the front surface and the front surface of the second metal member to form a polymerization portion.
A friction stir step in which a stirring pin of a rotating tool is inserted into the concave groove from the surface side of the first metal member, the rotating tool is relatively moved along the concave groove, and the polymerized portion is friction stir welded. Including
The concave groove is formed so as to form a closed loop.
The rotating tool has a columnar shoulder portion and a stirring pin hanging from the shoulder portion, and the diameter of the shoulder portion is set to be slightly smaller than the width of the concave groove.
In the friction stir step, the stirring pin is brought into contact with only the first metal member, or the first metal member and the second metal member to cause plastic fluidization, and the shoulder portion of the rotating tool is placed in the recessed groove. From the first metal member in a state where the outer peripheral surface of the shoulder portion and the side wall of the concave groove are separated from each other with a slight gap and the shoulder portion is separated from the bottom surface of the concave groove. A joining method characterized in that the polymerized portion is friction-stir welded while the generated burr is pressed by the shoulder portion. The joining method according to claim 2, wherein in the friction stir welding step, the rotary tool is made to go around along the concave groove to perform friction stir welding of the polymerized portions. A spiral groove is formed on the outer peripheral surface of the stirring pin, and when the spiral groove is formed counterclockwise from the base end to the tip, the rotation tool is rotated clockwise to base the spiral groove. The joining method according to any one of claims 1 to 3, wherein the rotation tool is rotated counterclockwise when the rotation tool is formed clockwise from the end to the tip. The joining method according to any one of claims 1 to 4, wherein the stirring pin hangs down from the shoulder portion and is tapered.

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