JP2021028079A - Joining method - Google Patents

Abstract

To provide a joining method for joining a body having a recess and a lid member by friction stir welding which can prevent occurrence of a drawing hole and a drawn mark by a stirring pin.SOLUTION: A joining method includes: a mounting step of mounting a lid body 2 on a body 1, thereby making a step side face of a peripheral wall step part and a side face of the lid body 2 abut each other and forming a first abutting part J1, and making a step bottom face of the peripheral wall step part and a rear face of the lid member 2 overlap each other and forming a second abutting part; a final joining step of inserting only a rotated stirring pin F2 into the first abutting part J1, moving a rotary tool F along the first abutting part J1 in the state where only the stirring pin F2 is brought into contact with the peripheral wall step part and the lid member 2 and performing friction stir, then moving the first abutting part along an inclined surface 3c of an inclined base 3 and drawing the stirring pin F2 on the upper side of the inclined surface 3c; and an inclined base removal step of cutting and removing the inclined base 3.SELECTED DRAWING: Figure 4

Description

The present invention relates to a joining method.

Friction stir welding is known as a technique for joining metal members to each other. Friction stir welding has a problem that a drawing hole remains when the stirring pin provided in the rotary tool is pulled out from the metal member. Therefore, a joining method is known in which no drawing hole remains in the metal member.

For example, in the joining method according to Patent Document 1, a method of reducing the pull-out mark by gradually pulling out while moving the stirring pin is disclosed.

Japanese Unexamined Patent Publication No. 2016-87649

However, the joining method of Patent Document 1 has a problem that a drawing mark remains in the plasticized region when the rotating tool is gradually pulled out.

Therefore, an object of the present invention is to provide a joining method capable of preventing the generation of pull-out holes and pull-out marks by a stirring pin when joining a main body provided with a recess and a lid member by friction stir welding.

The present invention is a joining method in which a main body provided with a recess and a lid member for sealing the opening of the recess are joined by friction stir welding, and the outer peripheral surface of a stirring pin of a rotary tool used for friction stir welding is tapered. The main body has a bottom portion and a peripheral wall portion rising from the peripheral edge portion of the bottom portion, and the inner peripheral wall portion of the peripheral wall portion has a step bottom surface that is one step lower than the end surface of the peripheral wall portion and the step bottom surface. A preparatory step of forming a peripheral wall stepped portion having a stepped side surface rising from the above, forming an inclined table that is close to the stepped side surface and protrudes from the end surface of the peripheral wall portion, and placing the lid member on the main body. As a result, the stepped side surface of the peripheral wall stepped portion and the side surface of the lid member are butted to form the first butted portion, and the stepped bottom surface of the peripheral wall stepped portion and the back surface of the lid member are overlapped to form the second butted portion. Along the first butt portion in a state where only the rotating stirring pin is inserted into the first butt portion and only the stirring pin is in contact with the peripheral wall step portion and the lid member. The rotary tool is moved to perform friction stir welding, and then the rotary tool is moved so as to rise along the inclined surface of the inclined surface to pull out the stirring pin on the upper side of the inclined surface. It is characterized by including a tilting table removing step of cutting and removing.

Further, the present invention is a joining method in which a main body provided with a recess and a lid member for sealing the opening of the recess are joined by friction stirring, and the outer peripheral surface of the stirring pin of the rotary tool used for friction stirring is tapered. The main body has a bottom portion and a peripheral wall portion rising from the peripheral edge portion of the bottom portion, and the inner peripheral wall portion of the peripheral wall portion has a step bottom surface that is one step lower than the end surface of the peripheral wall portion. A preparatory step of forming a peripheral wall step portion having a step side surface rising from the step bottom surface to form an inclined table that is close to the side surface of the lid member and protrudes from the surface of the lid member, and the lid member on the main body. By placing the above, the step side surface of the peripheral wall step portion and the side surface of the lid member are butted to form the first abutting portion, and the step bottom surface of the peripheral wall step portion and the back surface of the lid member are overlapped. In the mounting step of forming the second butt portion, only the rotating stirring pin is inserted into the first butt portion, and only the stirring pin is in contact with the peripheral wall step portion and the lid member. This joining step of moving the rotating tool along one butt portion to perform frictional agitation, and then moving the rotating tool so as to rise along the inclined surface of the inclined table and pulling out the stirring pin on the upper side of the inclined surface. It is characterized by including a tilting table removing step of cutting and removing the tilting table.

According to such a joining method, after friction stir welding, the stirring pin can be pulled out on an inclined table provided at a position different from the butt portion. In addition, the ramp can be cut off from the peripheral wall. This makes it possible to prevent the occurrence of pull-out holes and pull-out marks by the stirring pin.

According to the present invention, when the main body provided with the recess and the sealing body are joined by friction stir welding, it is possible to prevent the occurrence of pull-out holes and pull-out marks by the stirring pin.

It is an exploded perspective view which shows the preparation process of the joining method which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the mounting process of the joining method which concerns on 1st Embodiment of this invention. It is a top view which shows the main joining process of the joining method which concerns on 1st Embodiment of this invention. It is a perspective view of the end position of this joining process of the joining method which concerns on 1st Embodiment of this invention. Joining method according to the first embodiment of the present invention It is sectional drawing of the end position of this joining process. It is a perspective view which shows the joining method which concerns on 2nd Embodiment of this invention. It is a perspective view which shows the joining method which concerns on 3rd Embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to figures and the like. In the following description, the surface opposite to the "back surface" is referred to as the "front surface".

As shown in FIG. 1, in the joining method according to the present embodiment, the metal main body 1 and the metal lid member 2 are joined by friction stir welding to form a hollow container.

The main body 1 is a box-shaped body having an opening at the upper side. The main body 1 is composed of a bottom portion 10, a peripheral wall portion 11, and an inclined table 3. Although an aluminum alloy is used for the main body 1 in the present embodiment, it can be appropriately selected from metals capable of friction stir welding. For example, the main body 1 can be formed of an aluminum alloy, a magnesium alloy, a copper alloy, aluminum, magnesium, titanium, or the like.

The bottom portion 10 has a rectangular plate shape in a plan view. The peripheral wall portion 11 is erected on the peripheral edge of the bottom portion 10 and has a rectangular frame shape in a plan view. The peripheral wall portion 11 is composed of wall portions 11A, 11B, 11C, and 11D having the same plate thickness. The wall portions 11A and 11C are short side portions and face each other. The wall portions 11B and 11D have long sides and face each other. A recess 12 is formed inside the bottom portion 10 and the peripheral wall portion 11.

On the end surface 11a which is the end surface of the peripheral wall portion 11, a peripheral wall step portion 13 is formed along the inner peripheral edge of the peripheral wall portion 11 of the main body 1. The peripheral wall step portion 13 is composed of a step bottom surface 13a and a step side surface 13b rising from the step bottom surface 13a. The step bottom surface 13a is formed at a position one step lower than the end surface 11a.

The tilting table 3 is provided on the end surface 11a. The inclined table 3 is composed of an inclined table side surface 3a, an inclined table side surface 3b, an inclined surface 3c, and an approach portion 3d. The inclined table side surface 3a and the inclined table side surface 3b are side surfaces of the inclined table 3 and face each other. The inclined table side surface 3a is formed at a position separated from the step side surface 13b. The distance from the inclined table side surface 3a to the step side surface 13b is preferably set so that the rotating tool F and the inclined table 3 do not interfere with each other when the main joining step described later is performed.

The inclined surface 3c may be an inclined surface that gradually rises, and may be a flat surface or a curved surface. The lower end of the approach portion 3d is in contact with the step side surface 13b and the upper end is in contact with the inclined surface 3c, and the approach portion 3d is gently curved and inclined while changing the 90 ° direction. In the present embodiment, the tilting table 3 is provided on the end surface 11a of the wall portion 11D, but may be the end surface 11a of the wall portions 11A, 11B, 11C. Further, the lower end of the approach portion 3d may be separated from the step side surface 13b so as not to come into contact with the rotating tool F during the main joining step.

The main body 1 is preferably formed by die casting, for example. According to die casting, the main body 1 provided with the tilting table 3 can be easily integrally formed.

The lid member 2 is a rectangular plate member in a plan view that seals the opening of the main body 1. The material of the lid member 2 may be the same metal as that of the main body 1 or may be a different metal. The lid member 2 is formed in a size that allows it to be placed on the peripheral wall step portion 13 with almost no gap. The plate thickness dimension of the lid member 2 may be larger than the height dimension of the step side surface 13b.

Next, the joining method according to the present embodiment will be described. The joining method according to the present embodiment includes a preparation step, a mounting step, a main joining step, and a tilting table removing step.

As shown in FIG. 1, the preparatory step is a step of forming a main body 1 having an inclined table 3 and a recess 12 and a lid member 2 to be placed on the main body 1. The main body 1 is formed by die casting, for example.

As shown in FIG. 2, the mounting step is a step of mounting the lid member 2 on the peripheral wall stepped portion 13 formed on the main body 1. The stepped side surface 13b of the peripheral wall stepped portion 13 and the side surface 2c of the lid member 2 are butted to form the first butted portion J1. Further, the step bottom surface 13a of the peripheral wall step portion 13 and the bottom surface 2b of the lid member 2 are butted to form the second butted portion J2. The end surface 11a of the peripheral wall portion 11 and the surface 2a of the lid member 2 are flush with each other.

This joining step is a step of friction stir welding the first butt portion J1 using the rotary tool F. As shown in FIG. 2, the rotation tool F has a connecting portion F1 and a stirring pin F2. The stirring pin F2 hangs down 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, a spiral groove is carved counterclockwise from the base end to the tip end.

When rotating the rotation tool F counterclockwise, the spiral groove is carved clockwise from the base end to the tip end. In this way, the metal plastically fluidized by friction stir welding is guided by the spiral groove and moves to the tip side of the stirring pin F2. As a result, the amount of metal overflowing from the metal member to be joined (main body 1 and lid member 2) can be reduced.

In the main joining step, as shown in FIG. 3, the main step from the start position Sp to the intermediate point S1 and the detaching step from the intermediate point S1 to the end position Ep are performed. In this step, the rotary tool F is used to perform friction stir welding along the first butt portion J1. The rotation tool F is inserted into an arbitrarily set start position Sp, and the rotation tool F is moved clockwise along the first butt portion J1.

The insertion depth of the stirring pin F2 is set so that the tip of the stirring pin F2 reaches the step bottom surface 13a of the peripheral wall step portion 13 and only the stirring pin F2 contacts the lid member 2 and the peripheral wall portion 11. To do. Then, the rotation tool F is moved by tracing the first butt portion J1 while maintaining a constant height position.

A plasticized region W is formed in the movement locus of the rotation tool F. When the rotation tool F started from the start position Sp makes a round and reaches the start position Sp, the plasticization regions W are overlapped and moved to the intermediate point S1. When the rotation tool F reaches the intermediate point S1, the rotation tool F is not disengaged and the process proceeds to the disengagement step as it is.

As shown in FIG. 4, the detaching step is a step of moving the rotation tool F from the intermediate point S1 to the end position Ep and detaching it on the tilting table 3. In the detaching step, the rotation tool F is entered into the approach portion 3d and moved to the inclined surface 3c of the inclined table 3 while keeping the insertion depth constant. Then, the rotation tool F is moved along the inclined surface 3c while being gradually separated from the end surface 11a. When the rotation tool F reaches the end position Ep, the rotation tool F is raised to separate the rotation tool F from the inclined table 3.

Finally, a tilting table removing step of removing the tilting table 3 from the main body 1 is performed. In the inclined table removing step, for example, all the inclined table 3 is removed with reference to the end face 11a by cutting.

According to the joining method described above, the end position Ep of the rotation tool F is set on the inclined table 3, and the inclined table 3 is cut off. As a result, it is possible to prevent the pull-out hole and the pull-out mark from remaining in the main body 1. Further, as a result, no pull-out hole or pull-out mark remains on the surface of the main body 1, so that a clean finish can be achieved.

Further, since the rotation tool F is raised along the inclined surface 3c, when the rotation tool F is moved to the end position Ep, the stirring pin F2 and the end surface 11a can be separated from each other. As a result, the pull-out hole generated when the rotary tool F is detached does not remain in the main body 1, but can remain only in the inclined table 3.

Further, by providing the approach portion 3d on the inclined table 3, the rotating tool F can be smoothly moved from the first butted portion J1 to the inclined table 3 without reducing the moving speed. Further, since the lower end of the approach portion 3d is in contact with the step side surface 13b, it is possible to prevent the plasticized region W from remaining on the end surface 11a as much as possible during the detaching step.

(Second Embodiment)
Next, the joining method according to the second embodiment of the present invention will be described. In the present embodiment, the direction in which the inclined table is formed is different from that in the first embodiment. In this embodiment, a part different from the first embodiment will be described.

In the present embodiment, as shown in FIG. 6, the inclined table 3B is formed so that the inclined direction of the inclined surface 3c is perpendicular to the first butt portion J1. The lower end of the inclined surface 3c is in contact with the step side surface 13b. The lower end of the inclined surface 3c and the step side surface 13b may be separated from each other so as not to come into contact with the rotating tool F during the main joining step.

In the detaching step, in the first embodiment, when the rotation tool F is moved to the inclined surface 3c, it is moved via the approach portion 3d. However, in the present embodiment, since the inclined surface 3c is connected perpendicularly to the step side surface 13b, the rotating tool F can be easily inclined only by moving the rotating tool F 90 ° to the left at the intermediate point S1. It can be moved to the table 3B. The other configurations are the same as those in the first embodiment.

Even with the joining method described above, it is possible to obtain substantially the same effect as that of the first embodiment.

(Third Embodiment)
Next, the joining method according to the third embodiment of the present invention will be described. The present embodiment differs from the first embodiment in that the tilting table is formed on the lid member 2. In this embodiment, a part different from the first embodiment will be described.

As shown in FIG. 7, in the present embodiment, the tilting table 3C is formed so as to project on the surface 2a of the lid member 2. The approach portion 3d of the tilting table 3C has a lower end in contact with the side surface 2c of the lid member 2 and an upper end in contact with the inclined surface 3c, and is gently curved and inclined while changing the 90 ° direction. The lower end of the inclined surface 3c and the side surface 2c of the lid member 2 may be separated from each other so as not to come into contact with the rotating tool F during the main joining step.

The tilting table 3C of the lid member 2 can be formed by die casting, for example, as in the first embodiment. Thereby, the inclined table 3C and the lid member 2 can be easily integrally formed.

The joining step is the same as that of the first embodiment except that the joining step is separated by the tilting table 3C. Further, since the other configurations are the same as those in the first embodiment, detailed description thereof will be omitted. As described above, even the joining method according to the third embodiment can exhibit substantially the same effect as that of the first embodiment.

Although the present invention has been described above, the present invention is not limited to the above-described embodiments and modifications, and various changes can be made without departing from the spirit of the present invention.

For example, the configuration as in the second embodiment may be applied to the inclined table formed on the lid member 2 in the third embodiment. That is, the lid member 2 may be provided with an inclined table so that the inclined direction of the inclined surface is perpendicular to the side surface 2c of the lid member 2.

1 Main body 2 Lid member 3, 3B, 3C Inclined table 10 Bottom 11 Peripheral wall 11a End face 11A Wall 11B Wall 11C Wall 11D Wall 12 Recess 13 Peripheral wall step 13a Step bottom 13b Step side J1 First butt J2 Two butt parts F Rotation tool F1 Connection part F2 Stirring pin W Plasticization area

Claims (2)

It is a joining method in which a main body provided with a recess and a lid member for sealing the opening of the recess are joined by friction stir welding.
The outer peripheral surface of the stirring pin of the rotary tool used for friction stir is inclined so as to be tapered.
The main body has a bottom portion and a peripheral wall portion rising from the peripheral edge portion of the bottom portion, and the inner peripheral wall of the peripheral wall portion has a step bottom surface that is one step lower than the end surface of the peripheral wall portion and a step side surface that rises from the step bottom surface. A preparatory step of forming a stepped portion of the peripheral wall to have, and forming an inclined table that is close to the side surface of the stepped portion and protrudes from the end surface of the peripheral wall portion.
By placing the lid member on the main body, the step side surface of the peripheral wall step portion and the side surface of the lid member are abutted to form the first abutment portion, and the step bottom surface of the peripheral wall step portion and the lid member are formed. And the mounting process to form the second butt part by superimposing the back surface of
Only the rotating stirring pin is inserted into the first butt portion, and the rotating tool is moved along the first butt portion with only the stirring pin in contact with the peripheral wall step portion and the lid member. After performing friction stir, the main joining step of moving the stirrer so as to rise along the inclined surface of the inclined table and pulling out the stirring pin on the upper side of the inclined surface.
A joining method comprising a tilting table removing step of cutting and removing the tilting table. It is a joining method in which a main body provided with a recess and a lid member for sealing the opening of the recess are joined by friction stir welding.
The outer peripheral surface of the stirring pin of the rotary tool used for friction stir is inclined so as to be tapered.
The main body has a bottom portion and a peripheral wall portion that rises from the peripheral edge portion of the bottom portion, and a step bottom surface that is one step lower than the end surface of the peripheral wall portion and a step side surface that rises from the step bottom surface are provided on the inner peripheral wall of the peripheral wall portion. A preparatory step of forming a stepped portion of the peripheral wall to have, approaching the side surface of the lid member, and forming an inclined table protruding from the surface of the lid member.
By placing the lid member on the main body, the step side surface of the peripheral wall step portion and the side surface of the lid member are abutted to form the first abutment portion, and the step bottom surface of the peripheral wall step portion and the lid member are formed. And the mounting process to form the second butt part by superimposing the back surface of
Only the rotating stirring pin is inserted into the first butt portion, and the rotating tool is moved along the first butt portion with only the stirring pin in contact with the peripheral wall step portion and the lid member. After performing friction stir, the main joining step of moving the stirrer so as to rise along the inclined surface of the inclined table and pulling out the stirring pin on the upper side of the inclined surface.
A joining method comprising a tilting table removing step of cutting and removing the tilting table.

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