JP6794726B2 - Joining method - Google Patents

Description

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

For example, in Patent Document 1, end faces of metal members whose surface heights change are abutted to form a butt portion whose height changes, and only the stirring pin of the rotary tool is brought into contact with the butt portions of the metal members. A joining method is described in which friction stir welding is performed in the state of being joined.

JP-A-2015-199119

In the conventional joining method, since the plastically fluidized metal is not pressed by the shoulder portion of the rotating tool, the plastically fluidized metal overflows to the outside and the joint portion becomes short of metal, and the surface of the butt portion between the metal members There is a problem that a concave groove is formed in the metal.

Therefore, an object of the present invention is to provide a joining method capable of preventing a metal shortage at the joining portion.

In order to solve such a problem, the present invention is a joining method for joining a first metal member and a second metal member using a rotating tool provided with a stirring pin, wherein the height of the surface changes. The butt step of forming a butt portion by abutting the first metal member and the second metal member whose surface height changes, and the auxiliary member so as to make surface contact with the first metal member or the second metal member. The arrangement step of arranging and the rotating stirring pin are inserted into the butt portion whose height changes from the surface side of the auxiliary member, and only the stirring pin of the rotating tool is inserted into the first metal member and the first metal member. (Ii) A friction stirring step of joining the first metal member, the second metal member, and the auxiliary member by relatively moving the rotating tool along the abutting portion in a state of being in contact with the metal member and the auxiliary member. It is characterized by including.

According to this method, the butt portion whose height changes is joined, and in addition to the first metal member and the second metal member whose height changes, the auxiliary member is also friction-stir welded at the same time to join the joint portion. It is possible to prevent metal shortage. This makes it possible to prevent the formation of concave grooves on the surfaces of the first metal member and the second metal member.

It is also characterized by including a removing step of removing the auxiliary member on which burrs are formed from the first metal member or the second metal member.

According to such a method, the burr can be removed together with the auxiliary member.

Further, the friction stir welding step is characterized in that the joining conditions are set so that burrs generated in the friction stir welding are formed on the auxiliary member.

According to such a method, all burrs can be removed together with the auxiliary member.

Further, the present invention is a joining method for joining a first metal member and a second metal member using a rotating tool provided with a stirring pin, wherein the height of the surface of the first metal member and the surface changes. A butt step of forming a butt portion by abutting the second metal member whose height changes, and an arranging step of arranging an auxiliary member so as to make surface contact with both the first metal member and the second metal member. The rotating stirring pin is inserted into the butt portion whose height changes from the surface side of the auxiliary member, and only the stirring pin of the rotating tool is inserted into the first metal member, the second metal member, and the second metal member. A burr was formed with a friction stirring step of joining the first metal member, the second metal member, and the auxiliary member by relatively moving the rotating tool along the abutting portion in contact with the auxiliary member . The auxiliary member includes a removal step of removing the auxiliary member from the first metal member and the second metal member, and in the arrangement step, the auxiliary member is attached to either the first metal member or the second metal member. While arranging them, they are arranged so as to slightly project to the other side with the butt portion sandwiched between them. and wherein the setting child the joining conditions so as to form on either side of the bimetallic member.

According to this method, the butt portion whose height changes is joined, and in addition to the first metal member and the second metal member whose height changes, the auxiliary member is also friction-stir welded at the same time to join the joint portion. It is possible to prevent metal shortage. This makes it possible to prevent the formation of concave grooves on the surfaces of the first metal member and the second metal member. Further, since the stirring pin can be inserted from the vicinity of the center of the auxiliary member to the butt portion, the stirring pin can be easily inserted into the auxiliary member.
Further, burrs are formed on the auxiliary members separated by the friction stir welding step, and the burrs can be removed together with the auxiliary members in the removal step.
Further, since the slightly protruding portion of the auxiliary member is frictionally agitated by the stirring pin to fill the joint portion, the metal shortage of the joint portion can be prevented in a well-balanced manner and more reliably. Further, since the rotation center axis inserted into the butt portion is located at a position slightly deviated from the end face of the auxiliary member toward the center side, the stirring pin can be easily inserted into the auxiliary member.

Further, a spiral groove is engraved on the peripheral surface of the stirring pin, and when the rotation tool is rotated clockwise, the spiral groove is carved counterclockwise from the base end side to the tip end side of the stirring pin. When the rotation tool is rotated counterclockwise, the spiral groove is carved clockwise from the base end side to the tip end side of the stirring pin.

According to such a method, since the plastically fluidized metal material is guided by the spiral groove and moves to the tip end side of the stirring pin, the amount of metal overflowing to the outside of the metal member can be reduced.

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 1st metal member and the 2nd metal member of the joining method which concerns on 1st Embodiment of this invention. It is a perspective view which shows the butt process of the joining method which concerns on 1st Embodiment. It is a perspective view which shows the 1st metal member, the 2nd metal member and the auxiliary member of the joining method which concerns on 1st Embodiment. It is a side sectional view which shows the butt process and the arrangement process of the joining method which concerns on 1st Embodiment. 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 sectional drawing which shows the friction stir step of the joining method which concerns on 1st Embodiment. It is sectional drawing which shows before the removal process of the joining method which concerns on 1st Embodiment. It is sectional drawing which shows the removal process of the joining method which concerns on 1st Embodiment. It is sectional drawing which shows after the removal process of the joining method which concerns on 1st Embodiment. It is sectional drawing which shows the friction stir step (deformation example) of the joining method which concerns on 1st Embodiment. It is sectional drawing which shows the butt process and the arrangement process of the 2nd Embodiment of this invention. It is a perspective view which shows the friction stir step of the joining method which concerns on 2nd Embodiment. It is sectional drawing which shows the friction stir step of the joining method which concerns on 2nd Embodiment. It is sectional drawing which shows the removal process of the joining method which concerns on 2nd Embodiment. It is sectional drawing which shows the butt process and the arrangement process of the 3rd Embodiment of this invention. It is a perspective view which shows the friction stir step of the joining method which concerns on 3rd Embodiment. It is sectional drawing which shows the friction stir step of the joining method which concerns on 3rd Embodiment. It is sectional drawing which shows the removal process of the joining method which concerns on 3rd Embodiment. It is sectional drawing which shows the butt process of the joining method which concerns on another embodiment. It is a side sectional view which shows the friction stir step of the joining method which concerns on another 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. In the joining method according to the present embodiment, a butt step, a placement step, a friction stir step, and a removal step are performed. In the following description, the "front surface" means the surface opposite to the "back surface".

The joining method according to the first embodiment will be described. In the present embodiment, the end faces 1a and 1a of the first metal member 1A and the second metal member 1B shown in FIG. 1 are joined to each other by friction stir welding to form abutment portions J formed by abutting each other as shown in FIG. The first metal member 1A and the second metal member 1B (first and second metal members 1A, 1B) are metal members, and the abutting end faces 1a, 1a have the same shape. Further, the first and second metal members 1A and 1B are made of the same material. This material is not particularly limited as long as it is a metal that can be agitated by friction, but may be appropriately selected from, for example, aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, magnesium, magnesium alloy and the like.

As shown in FIG. 1, the first and second metal members 1A and 1B are composed of a main body 2 having a rectangular parallelepiped shape and a convex portion 3 formed on the main body 2 and having a trapezoidal cross section. The surface 3a of the convex portion 3 is located above the surfaces 2a and 2b of the main body portion 2. The first surface 3b of the convex portion 3 is inclined and connects the surface 2a of the main body portion 2 and the surface 3a of the convex portion 3. Further, the second surface 3c of the convex portion 3 is inclined so as to connect the surface 2b of the main body portion 2 and the surface 3a of the convex portion 3.

In the joining method according to the present embodiment, a butt step and a joining step are performed. As shown in FIG. 1, the butting step is a step of butting the end faces 1a and 1a of the first and second metal members 1A and 1B. In the butting step, the surfaces of the first and second metal members 1A and 1B are butted so as to be flush with each other.

As shown in FIG. 2, the end faces 1a and 1a come into surface contact with each other by the butt step to form the butt portion J. The butt portion J is formed so that its height position changes. That is, assuming that the height (elevation) of the start point (insertion position) of friction stir welding is the reference height, the butt portion J has sections having different reference heights and heights from the start point to the end point. In the present embodiment, the butt portion J is composed of a first flat portion Ja, a first inclined portion Jb, a second flat portion Jc, a second inclined portion Jd, and a third flat portion Je.

The arranging step is a step of arranging the auxiliary member 10 on the first and second metal members 1A and 1B in the butt state shown in FIG. The auxiliary member 10 is a metal plate-shaped member. The auxiliary member 10 is not particularly limited as long as it is a metal capable of friction stir welding, but in the present embodiment, it is made of the same material as the first and second metal members 1A and 1B. The plate thickness of the auxiliary member 10 is appropriately set so that the plasticized region W after the friction stir welding step described later does not run out of metal.

The auxiliary member 10 is a plate-shaped member having a constant plate thickness and different heights. The auxiliary member 10 is composed of base portions 11 and 11, a central portion 12, and inclined portions 13 and 14. The central portion 12 is formed at a position higher than the bases 11 and 11 in the center of the bases 11 and 11. The inclined portion 13 obliquely connects one base portion 11 and the central portion 12. The inclined portion 14 obliquely connects the other base portion 11 and the central portion 12. Further, slits 15 and 15 are provided near the center of each end of the bases 11 and 11.

In the arranging step, as shown in FIGS. 3 and 4, the back surfaces of the auxiliary members 10 are brought into surface contact along the central portions of the surfaces of the first and second metal members 1A and 1B in the butt state. More specifically, the front surfaces 2a and 2b of the main body 2 of the first and second metal members 1A and 1B in the butt state and the back surfaces 11b and 11b of the bases 11 and 11 of the auxiliary member 10 are overlapped and the convex portion 3 is overlapped. The front surface 3a of the above and the back surface 12b of the central portion 12 are overlapped with each other. Further, the inclined first surface 3b of the convex portion 3 and the back surface 13b of the inclined portion 13 are overlapped, and the inclined second surface 3c of the convex portion 3 and the back surface 14b of the inclined portion 14 are overlapped.

Further, the first and second metal members 1A and 1B in the butt state and the auxiliary member 10 are immovably restrained on the gantry T by using a jig (not shown). Although the auxiliary member 10 has a plate shape having different heights in the present embodiment, it may have another shape as long as it comes into surface contact with the surfaces of the first and second metal members 1A and 1B.

As shown in FIG. 5, the friction stir welding step is a step of joining the butt portions J of the first and second metal members 1A and 1B in the butt state by friction stir welding using the joining rotary tool F. The joining rotary tool F is composed of a connecting portion F1 and a stirring pin F2. The rotary tool F for joining corresponds to the "rotation tool" in the claims. The rotary tool F for joining is made of, for example, tool steel. The connecting portion F1 is a portion connected to a rotating shaft (not shown) of the friction stirrer. The connecting portion F1 has a columnar shape.

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 joining rotation tool F clockwise, the spiral groove 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 joint rotation tool F 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 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 and second metal members 1A and 1B in the butt state and the auxiliary member 10) can be reduced.

The joining rotary tool F may be attached to a friction stir device such as a machining center, or may be attached to, for example, an arm robot having a rotating means such as a spindle unit at the tip. By attaching the joining rotation tool F to the arm robot, the rotation center axis Fc of the joining rotation tool F can be easily tilted.

In the friction stir welding step, as shown in FIG. 5, the stirring pin F2 of the joining rotation tool F rotated clockwise is inserted into the start position Sp set on the surface of the auxiliary member 10. In the present embodiment, the insertion depth of the stirring pin F2 is set so that the stirring pin F2 contacts (reaches) the first and second metal members 1A and 1B. Further, friction stirring is performed in a state where the rotation center axis of the joining rotation tool F is always parallel to the vertical axis. By the friction stir step, the first and second metal members 1A and 1B around the stirring pin F2 are frictionally agitated, and the first and second metal members 1A and 1B are joined. A plasticized region W is formed in the movement locus of the joining rotation tool F.

That is, in the friction stir welding step, as shown in FIG. 6, while keeping the insertion depth of the stirring pin F2 with respect to the butt portion J substantially constant, only the stirring pin F2 is used as the auxiliary member 10 and the first and second metal members 1A. Friction stir welding is performed in contact with 1B. In the friction stir welding step according to the present embodiment, the joining rotary tool F is placed on the pedestal T to which the auxiliary member 10, the first and second metal members 1A and 1B are fixed, and the height (elevation) of the auxiliary member 10 is raised and lowered. ) Is moved up and down to perform friction stir welding.

As a result, the depth Za of the plasticized region W of the first flat portion Ja and the depth Zb of the plasticized region W of the first inclined portion Jb (the depth of the plasticized region W on the line orthogonal to the surface 13a of the inclined portion 13). The depth Zc of the plasticized region W of the second flat portion Jc can be made substantially the same. The "insertion depth" of the stirring pin F2 means the distance from the surface of the auxiliary member 10 on the rotation center axis Fc of the joining rotation tool F to the tip of the stirring pin F2.

By the above friction stirring step, the periphery of the stirring pin F2 is frictionally stirred, and the first and second metal members 1A and 1B are joined. At this time, as shown in FIGS. 7 and 8, burrs V are formed on the surface portion of the auxiliary member 10. In this embodiment, since the joining rotation tool F is rotated at high speed, burrs tend to occur more on the flow side than on the shear side, which will be described later.

As shown in FIGS. 9 and 10, the removing step is a step of removing the auxiliary member 10 from the first and second metal members 1A and 1B. In the removing step, for example, the auxiliary member 10 is manually bent from both sides in a direction away from the first and second metal members 1A and 1B to be removed from the first and second metal members 1A and 1B. At this time, the auxiliary member 10 is removed by bending it while turning up the end portion starting from one of the slits 15 and 15 (see FIG. 5).

According to the joining method according to the present embodiment described above, the first metal member 1A and the second metal member 1B are joined, and in addition to the first and second metal members 1A and 1B, the auxiliary member 10 is simultaneously rubbed. By stirring and joining, it is possible to prevent a metal shortage in the joint portion (plasticized region W). As a result, it is possible to prevent the formation of a concave groove on the surface of the butt portion J of the first and second metal members 1A and 1B.

Further, by inserting the stirring pin F2 from the central portion of the auxiliary member 10 toward the butt portion J, it is possible to more reliably prevent the metal shortage of the joint portion and to replenish the metal in a well-balanced manner. Further, by inserting the stirring pin F2 from the central portion of the auxiliary member 10, the stirring pin F2 can be easily inserted into the auxiliary member 10.

Further, according to the present embodiment, burrs V and V are formed on the auxiliary members 10 separated by the friction stir welding step, respectively, but the burrs V and V can be removed together with the auxiliary members 10 in the removing step. As a result, the work of removing the burrs V and V can be easily performed. The auxiliary member 10 may be removed by using a removing device or the like, but in the present embodiment, the auxiliary member 10 can be easily removed manually.

Here, in the joining method according to the present embodiment, since the auxiliary member 10 is set to be significantly thinner than the first and second metal members 1A and 1B, the shoulder portion of the rotating tool is made of a metal member as in the conventional case. If friction stir is performed while pushing in, the auxiliary member 10 is blown to the outside due to the contact between the shoulder portion and the auxiliary member 10, and the metal shortage of the joint portion to which the butt portion J is joined cannot be compensated. However, in the present embodiment, since only the stirring pin F2 of the rotary tool F for joining is brought into contact with the auxiliary member 10 and the first and second metal members 1A and 1B for frictional stirring, the auxiliary member 10 is blown to the outside. It is possible to make up for the metal shortage at the joint without any need. Further, according to the present embodiment, the deep position of the butt portion J on the lower side of the auxiliary member 10 is joined in a state where the load acting on the friction stir device is reduced as compared with the case where the shoulder portion of the rotary tool is brought into contact with the shoulder portion. can do.

[Modification example]
FIG. 11 is a cross-sectional view showing a friction stir step of a modified example of the joining method according to the first embodiment. As shown in FIG. 11, in the modified example, when the friction stir welding step is performed, the friction stir welding is performed while inserting the joining rotation tool F perpendicularly to the upper surface of the butt portion J. In the friction stir welding step of the modified example, in the first flat portion Ja, the second flat portion Jc, and the third flat portion Je, the rotation center axis Fc of the joining rotation tool F is parallel to the vertical axis as in the first embodiment. Friction stir welding is performed in this state. On the other hand, in the first inclined portion Jb and the second inclined portion Jd, the joining rotation tool F is inclined with respect to the vertical axis, and the joining rotation tool F is inclined with respect to the surfaces of the first and second metal members 1A and 1B. Friction stir welding is performed with the rotation center axis Fc of F vertical.

When performing a modification, for example, it is preferable to attach the joining rotary tool F to a robot arm having a driving means such as a spindle unit at the tip to perform friction stir welding. According to such a friction stirrer, the angle of the rotation center axis Fc of the joining rotation tool F can be easily changed. As a result, even when the height of the butt portion J changes, by changing the angle of the rotation center axis Fc of the joining rotation tool F with respect to the vertical axis during friction stir welding, the first and second metal members 1A, Friction stir welding can be continuously performed with the joining rotation tool F always perpendicular to the surface of 1B.

Even in the above-described modification, the same effect as that of the first embodiment can be obtained. Further, since the rotary tool F for joining can be inserted perpendicularly to the surfaces of the first and second metal members 1A and 1B, friction stirring is performed to a deep position of the butt portion J even on an inclined surface. Can be done.

[Second Embodiment]
Next, the joining method according to the second embodiment will be described. The joining method according to the second embodiment is different from the first embodiment in that the rotary tool F for joining is inserted from the end surface 10a of the auxiliary member 10A shown in FIG. Further, the auxiliary member 10A is different in that the slits 15 and 15 are not formed. In the joining method according to the second embodiment, the parts different from the first embodiment will be mainly described.

The joining method according to the present embodiment includes a butt step, a placement step, a friction stir step, and a removal step. Since the butt step is the same as that of the first embodiment, the description thereof will be omitted. In the arranging step, as shown in FIGS. 12 and 13, the auxiliary member is aligned with the end face 10a on the surface of the first metal member 1A and on the boundary line X of the butt portions J of the first and second metal members 1A and 1B. Place 10A. The auxiliary member 10A of the second embodiment has a width of about half that of the auxiliary member 10 of the first embodiment.

As shown in FIGS. 13 and 14, the friction stir welding step is a step of joining the butt portions J of the first metal member 1A and the second metal member 1B by friction stir welding using the joining rotary tool F. In the present embodiment, in order to rotate the joining rotation tool F counterclockwise, the spiral groove of the stirring pin F2 is formed clockwise from the base end to the tip end. In other words, the spiral groove is formed clockwise when viewed from above when the spiral groove is traced from the base end to the tip end.

In the friction stir welding step, only the stirring pin F2 rotated counterclockwise is inserted, and the metal member to be joined and the connecting portion F1 are relatively moved while being separated from each other. In other words, friction stir welding is performed with the base end portion of the stirring pin F2 exposed. In the friction stir welding step, as shown in FIG. 13, the rotation center axis Fc of the joining rotation tool F is superposed on the boundary line X, and the first and second metal members 1A and 1B and the auxiliary members 10A are stirred. The joint rotation tool F is relatively moved while being in contact with the pin F2.

In the present embodiment, the joining rotation tool F is set so that the shear side of the joining rotation tool F (advancing side: the side where the moving speed of the rotating tool is added to the tangential velocity on the outer circumference of the rotating tool) is on the right side in the traveling direction. The movement direction and rotation direction of are set. The rotation direction and the traveling direction of the joining rotation tool F are not limited to those described above, and may be appropriately set.

For example, when the rotation speed of the joining rotation tool F is slow, the shear side is compared with the flow side (retreating 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) of the plasticized region W. In this case, the temperature of the plastic fluid material tends to rise, so that a large amount of burr V tends to occur on the shear side outside the plasticized region W. On the other hand, for example, when the rotation speed of the joining rotation tool F is high, the temperature of the plastic fluid material rises on the shear side, but the rotation speed is high, so that there are many burrs V on the flow side outside the plasticization region W. It tends to occur.

In the present embodiment, since the rotation speed of the joining rotation tool F is set to be high, as shown in FIG. 14, many burrs V tend to occur on the flow side outside the plasticization region W. Further, by setting the rotation speed of the joining rotation tool F to be high, the moving speed (feeding speed) of the joining rotation tool F can be increased. As a result, the joining cycle can be shortened.

In the friction stir step, which side of the joining rotary tool F in which the burr V is generated in the traveling direction depends on the joining conditions. The joining conditions include the rotation speed, rotation direction, movement speed (feed speed) of the joining rotation tool F, the inclination angle (taper angle) of the stirring pin F2, the first and second metal members 1A and 1B, and the auxiliary member 10A. It is determined by each element such as the material and thickness of the material and the combination of these elements. In the friction stir welding step, it is preferable to set the joining conditions so that the burr V is formed on the auxiliary member 10A. In the present embodiment, the insertion depth of the stirring pin F2 is set so that the stirring pin F2 contacts (reaches) the first and second metal members 1A and 1B.

As shown in FIG. 15, the removing step is a step of removing the auxiliary member 10A from the first metal member 1A. In the removing step, for example, the auxiliary member 10A is manually bent in a direction away from the first metal member 1A as shown by an arrow and removed from the first metal member 1A. As a result, the first and second metal members 1A and 1B are joined at the butt portion J.

According to the joining method according to the present embodiment described above, the first metal member 1A and the second metal member 1B are joined at the butt portion J, and the auxiliary member 10A is also jointed by friction stir welding at the same time. It is possible to prevent a metal shortage in the (plasticized region W). As a result, it is possible to prevent the formation of concave grooves on the surfaces of the first metal member 1A and the second metal member 1B.

Further, according to the present embodiment, the burr V is formed on the auxiliary member 10A by the friction stir welding step, but the auxiliary member 10A can be removed together with the auxiliary member 10A in the removing step. As a result, the work of removing the burr V can be easily performed. The auxiliary member 10A may be removed by using a removing device or the like, but in the present embodiment, the auxiliary member 10A can be easily removed manually in the direction indicated by the arrow.

[Third Embodiment]
Next, the joining method according to the third embodiment of the present invention will be described. As shown in FIGS. 16 to 19, in the joining method according to the third embodiment, the arrangement position of the auxiliary member 10B and the insertion position of the stirring pin F2 are mainly different from those of the second embodiment. The joining method according to the third embodiment will mainly explain the differences from the second embodiment. The joining method according to the third embodiment includes a butt step, a placement step, a friction stir step, and a removal step.

Since the butt step is the same as that of the second embodiment, the description thereof will be omitted. As shown in FIG. 16, in the arranging step, the auxiliary member 10B is mainly arranged on the surface of the second metal member 1B, and the end surface 10a slightly protrudes from the boundary line X toward the surface side of the first metal member 1A. Auxiliary member 10B is arranged. Regarding the distance from the boundary line X to the end face 10a, no metal shortage occurs in the joint (plasticized region W) after the friction stir welding step described later, and the auxiliary member 10B remains in the first metal member 1A after the friction stir welding step. Set to the extent that it does not.

As shown in FIG. 17, the friction stir welding step is a step of joining the butt portions J of the first and second metal members 1A and 1B by friction stir welding using the joining rotation tool F. In the present embodiment, in order to rotate the joining rotation tool F clockwise, the spiral groove of the stirring pin F2 is formed counterclockwise from the base end to the tip end.

In the friction stir welding step, while aligning the rotation center axis Fc of the joining rotation tool F with the boundary line X (see FIG. 16), only the stirring pin F2 rotated clockwise is inserted into the butt portion J to form a metal member to be joined. It is moved relative to the connecting portion F1 while being separated from the connecting portion F1. In the present embodiment, as shown in FIG. 17, the traveling direction of the joining rotation tool F is set so that the auxiliary member 10B is located on the right side of the traveling direction of the joining rotation tool F, and the joint rotation tool F is rotated at high speed. As a result, in the present embodiment, as shown in FIG. 18, burr V is generated on the flow side of the auxiliary member 10B.

The removing step is a step of removing the auxiliary member 10B from the second metal member 1B, as shown in FIG. In the removing step, for example, the auxiliary member 10B is manually bent in the direction away from the second metal member 1B (in the direction of the arrow) and removed from the second metal member 1B.

According to the joining method according to the present embodiment described above, the first metal member 1A and the second metal member 1B are joined, and in addition to the first metal member 1A and the second metal member 1B, the auxiliary member 10B is also joined at the same time. By friction stir welding, it is possible to prevent metal shortage at the joint portion (plasticized region W).

Further, according to the joining conditions of the present embodiment, since the rotation speed of the joining rotation tool F is set to be high, many burrs V tend to occur on the flow side outside the plasticization region W. That is, the rotation direction, the traveling direction, and the like (joining conditions) of the joining rotation tool F are set so that the burr V is concentrated on the auxiliary member 10B remaining after the friction stir welding step. As a result, the burr V formed on the auxiliary member 10B is removed together with the auxiliary member 10B, so that the burr removing step can be performed more easily. A removing device or the like may be used for the auxiliary member 10B, but in the present embodiment, the auxiliary member 10B can be easily removed by hand.

Here, in the removal step of the first embodiment described above, it is necessary to remove the auxiliary members 10 on both sides of the center of the plasticized region W. However, in the present embodiment, the auxiliary member 10B does not remain on the other side of the boundary line X (the side of the first and second metal members 1A and 1B having a smaller contact area ratio with the auxiliary member 10B) after the friction stirring step. Since the arrangement position of the auxiliary member 10B is adjusted, it remains on one side of the boundary line X (the side of the first and second metal members 1A and 1B having a large contact area ratio with the auxiliary member 10B) in the removal step. All that is required is to remove the auxiliary member 10B. As a result, the labor of the removal process can be reduced.

The position of the auxiliary member 10B is such that the end face 10a slightly protrudes beyond the boundary line X toward the first metal member 1A (the other side). Therefore, the protruding auxiliary member 10B is also frictionally agitated by the stirring pin F2 to fill the joint (plasticized region W), so that the metal shortage of the joint can be prevented more reliably and in a well-balanced manner. Can be done. Further, since the rotation center axis Fc is located at a position slightly deviated from the end surface 10a of the auxiliary member 10B toward the center side, the stirring pin F2 can be easily inserted into the auxiliary member 10B.

[Other Embodiments]
Next, other embodiments of the present invention will be described. In the joining method according to another embodiment, a butt step, a placement step, a friction stir step, and a removal step are performed. The other embodiment differs from the first to third embodiments in that the metal members are curved vertically.

As shown in FIGS. 20 and 21, in the butt step, the first and second metal members 30A in which the butt portion J is formed by abutting the first metal member 30A and the second metal member 30B having a curved upper surface. , 30B are formed of a metal capable of friction stir welding, and are curved with the same radius of curvature so that the surfaces 30a and 30a are flush with each other.

In the arranging step, the back surface 50b of the plate-shaped auxiliary member 50 curved in the same shape as the first and second metal members 30A and 30B is placed at the center of the surface of the first and second metal members 30A and 30B in the butt state. Make surface contact along. The first and second metal members 30A and 30B and the auxiliary member 50 are immovably restrained by the gantry T by using a jig (not shown).

The friction stir welding step is a step of friction stir welding the butt portion J using the joining rotary tool F. In the friction stir welding step, the stirring pin F2 of the joining rotary tool F is inserted from the surface 50a of the auxiliary member 50 to the butt portion J of the first and second metal members 30A and 30B, and the joining rotating tool is inserted along the butt portion J. Move F relative to each other. In the friction stir welding step, the inclination angle of the joining rotation tool F is gradually changed so that the rotation center axis Fc of the joining rotation tool F overlaps the normals of the auxiliary member 50 and the first and second metal members 30A and 30B. .. Further, in the friction stir welding step, the insertion depth of the stirring pin F2 is set so that the depth of the plasticized region W1 is constant. Since the removal step is the same as that of the first embodiment, the description thereof will be omitted.

Even when the butt portion J is curved in the vertical direction and the height changes as in the joining method according to the other embodiments described above, the effect is substantially the same as that of the first to third embodiments. Can be played.

Although the embodiments of the present invention have been described above, the design can be appropriately changed within a range not contrary to the gist of the present invention. For example, although the removal step was performed in the present embodiment, the auxiliary members may be left as they are in the first and second metal members without being removed.

1A, 30A 1st metal member 1B, 30B 2nd metal member 10, 10A, 10B, 50 Auxiliary member F Rotation tool for joining (rotation tool)
F1 Connection part F2 Stirring pin Fc Rotation center axis J Butt part V Bali W Plasticization area X Boundary line

Claims (5)

A joining method for joining a first metal member and a second metal member using a rotating tool equipped with a stirring pin.
A butt step of forming a butt portion by abutting the first metal member whose surface height changes and the second metal member whose surface height changes.
An arrangement step of arranging the auxiliary member so as to make surface contact with the first metal member or the second metal member, and
The rotating stirring pin is inserted into the butt portion whose height changes from the surface side of the auxiliary member, and only the stirring pin of the rotating tool is inserted into the first metal member, the second metal member, and the auxiliary. It is characterized by including a friction stir step of joining the first metal member, the second metal member and the auxiliary member by relatively moving the rotation tool along the abutting portion in a state of being in contact with the member. Joining method to do. The joining method according to claim 1, further comprising a removing step of removing the auxiliary member on which burrs are formed from the first metal member or the second metal member. The joining method according to claim 2, wherein in the friction stir welding step, joining conditions are set so that burrs generated in the friction stir welding are formed on the auxiliary member. A joining method for joining a first metal member and a second metal member using a rotating tool equipped with a stirring pin.
A butt step of forming a butt portion by abutting the first metal member whose surface height changes and the second metal member whose surface height changes.
An arrangement step of arranging the auxiliary member so as to make surface contact with both the first metal member and the second metal member, and
The rotating stirring pin is inserted into the butt portion whose height changes from the surface side of the auxiliary member, and only the stirring pin of the rotating tool is inserted into the first metal member, the second metal member, and the auxiliary. A friction stir step of joining the first metal member, the second metal member, and the auxiliary member by relatively moving the rotation tool along the abutting portion in contact with the members .
Including a removal step of removing the auxiliary member on which burrs are formed from the first metal member and the second metal member.
In the arrangement step, the auxiliary member is arranged on one of the first metal member and the second metal member, and is arranged so as to slightly project to the other side with the butt portion sandwiched between them.
In the friction stir process, burrs generated in friction stir welding, and a setting child the joining conditions so as to form on either side of the first metal member and the second metal member of the auxiliary member A characteristic joining method. A spiral groove is engraved on the peripheral surface of the stirring pin.
When rotating the rotation tool clockwise, the spiral groove is carved counterclockwise from the base end side to the tip end side of the stirring pin.
One of claims 1 to 4 , wherein when the rotation tool is rotated counterclockwise, the spiral groove is carved clockwise from the base end side to the tip end side of the stirring pin. The joining method described in.

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