JP2018051568A - Joint method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint method capable of preventing position deviation of the metal members from each other and separation of those from each other during a friction stir joint, and further capable of correcting deformation of the metal member.SOLUTION: An objective joint method includes: a butting process of inserting the end face 2c of a second platy metal member 2 in a recessed groove of a first platy metal member 1 having the recessed groove on a rear face 1a to butt the end face 2c on the bottom face 3a of the recessed groove; a welding process of carrying out a welding operation to the inner corner formed by the rear face 1a of the first metal member 1 and the side face of the second metal member 2; and a friction stirring process of inserting the stirring pin F2 of a rotary tool F from the surface 1b side of the first metal member 1, and relatively moving the rotary tool F along the recessed groove to carry out the friction stirring joint of the butting part J in such a state as contacting the stirring pin F2 with the first metal member 1 only or both of the first and second metal members 1 and 2.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for joining plate-shaped metal members.

  Patent Document 1 discloses a joining method in which a plate-like first metal member and a plate-like second metal member are butted together in a T shape. In this joining method, a back surface of the first metal member and an end surface of the second metal member are butted together to form a butted portion, and a rotating tool is pushed from the surface of the first metal member to frictionally weld the butted portion. And a friction stirring step.

Japanese Patent No. 3947271

  Since the prior art is a form in which the second metal member is inserted into the concave groove of the first metal member, there is a problem that the positions of the metal members are shifted in the longitudinal direction of the second metal member during friction stir welding. Further, if the first metal member is separated so as to be lifted with respect to the second metal member during the friction stir welding, there is a risk of causing a bonding defect. Further, in the prior art, the surface side of the first metal member (the surface side on which the rotary tool is inserted) becomes concave due to the frictional heat during friction stir welding (the tip side of the first metal member is the second metal member) There is a risk of deformation.

  From such a point of view, the present invention provides a joining method capable of preventing the positions of the metal members from shifting and separating the metal members during friction stir welding, and further correcting the deformation of the metal members. The issue is to provide.

  In order to solve such a problem, the present invention provides a plate-like second metal member end face inserted into the concave groove of the first metal member that has a plate-like shape and has a concave groove on the back surface. A butting step of butting the bottom surface of the first metal member, a welding step of welding the inner corner formed by the back surface of the first metal member and the side surface of the second metal member, and from the surface side of the first metal member A friction stirring step of inserting a stirring pin of a rotating tool, relatively moving the rotating tool along the concave groove, and friction stir welding the butted portion, and in the friction stirring step, the stirring pin is The butt portion is friction stir welded in a state where only the first metal member or both the first metal member and the second metal member are in contact with each other.

According to this method, since the welding process is performed, it is possible to prevent displacement and separation of metal members during the friction stirring process. Thereby, generation | occurrence | production of the joining defect accompanying the position shift and separation | spacing of a metal member can be prevented. Moreover, although it deform | transforms so that the back surface side of a 1st metal member may become concave by the welding heat at the time of welding, the said deformation | transformation can be corrected with the frictional heat at the time of friction stir welding.
Moreover, according to this method, since the concave groove is formed in the first metal member, the thickness of the portion of the first metal member where the concave groove is formed is thinner than the thickness of the other portion. . This makes it possible to reduce the depth of insertion of the agitation pin in the friction agitation process as compared with the case where no concave groove is formed. It can be carried out.

  In the friction stirring step, only the stirring pin of the rotating tool is inserted from the surface of the first metal member, and only the stirring pin is only the first metal member, or the first metal member and the second metal. The butt portion is preferably friction stir welded in a state where both the members are in contact with each other.

  Thereby, since only the stirring pin of the rotary tool is in contact with the metal member, the width of the plasticizing region can be reduced. If the width of the plasticized region can be reduced, it is advantageous when the thickness of the second metal member is small. In addition, by bringing only the stirring pin of the rotary tool into contact with the metal member, friction stirring can be performed to a deep position without applying a large load to the friction stirring device, which is advantageous when the plate thickness of the first metal member is large.

  Moreover, it is preferable that the said rotation tool has a shoulder part which exhibits columnar shape, and the stirring pin hanging from the said shoulder part, and sets the diameter of the said shoulder part smaller than the width | variety of the said groove.

  Thereby, since the shoulder part of the rotary tool is pushed into the metal member, the occurrence of burrs can be reduced. In addition, since the groove | channel of a plasticization area | region will become shallow if the pushing amount of a shoulder part is made small, the surface of a 1st metal member can be finished finely. Moreover, since the diameter of the shoulder portion is formed to be smaller than the width of the concave groove, the material plastically fluidized by the stirring pin of the rotary tool is prevented from jumping out from the inner corners of the first metal member and the second metal member. be able to.

  In the welding process, it is preferable that overlay welding is continuously performed on the inner corner in one pass. In the welding process, it is preferable to intermittently build up the inner corner with a gap. In the welding process, it is preferable to perform laser welding, MIG welding, or TIG welding. Thereby, an inner corner can be joined reliably.

  Further, in the friction stirring step, it is preferable that a pair of mounts are disposed on both sides of the second metal member, and a chamfered portion is formed in a portion of the mount that faces the inner corner. Thereby, since it can avoid that the weld metal formed in an inner corner and a mount stand, a metal member can be arrange | positioned suitably at a mount.

  Further, in order to solve such a problem, the present invention provides a plate-like end surface of the first metal member that has a notched corner portion on the back surface and a plate-like third surface that has a notched corner portion on the back surface side. A first butting portion having a concave groove is formed by abutting the end surface of the metal member, and an end surface of the plate-like second metal member is inserted into the concave groove and the end surface is abutted against the bottom surface of the concave groove. Welding is applied to the inner corner formed by the butting step for forming the butting portion, the back surface of the first metal member and the side surface of the second metal member, and the back surface of the third metal member and the second metal member. A welding step of welding the inner corner formed by the side surface of the metal member, and inserting a stirring pin of a rotary tool from the surface side of the first metal member and the surface side of the third metal member, and the rotation A tool is relatively moved along the concave groove, and the first butting portion and A friction stir step for friction stir welding the second butted portion, wherein in the friction stir step, the stir pin is only the first metal member and the third metal member, or the first metal member, The first butted portion and the second butted portion are friction stir welded in a state where they are in contact with the three metal members and the second metal member.

According to this method, since the welding process is performed, it is possible to prevent displacement and separation of metal members during the friction stirring process. Thereby, generation | occurrence | production of the joining defect accompanying the position shift and separation | spacing of a metal member can be prevented. Moreover, although it deform | transforms so that the back surface side of a 1st metal member and the back surface side of a 3rd metal member may become concave with the welding heat at the time of welding, the said deformation | transformation can be corrected with the friction heat at the time of friction stir welding.
Moreover, according to this method, since the first metal member and the third metal member are formed with the groove, the thickness of the portion where the groove is formed is thinner than the thickness of the other portion. . Thereby, in the friction stirring step, the depth at which the stirring pin is inserted can be reduced as compared with the case where the concave groove is not formed. Friction stir welding of the butt portion can be performed.

  According to the joining method according to the present invention, it is possible to prevent the positions of the metal members from being shifted and the metal members from being separated from each other during the friction stir welding, and further to correct the deformation of the metal members.

It is a perspective view which shows the butt | matching process of the joining method which concerns on 1st embodiment of this invention. It is a perspective view which shows the welding process of the joining method which concerns on 1st embodiment. It is sectional drawing which shows the friction stirring process (installation process to a mount frame) of the joining method which concerns on 1st embodiment. It is a perspective view which shows the friction stirring process of the joining method which concerns on 1st embodiment. It is sectional drawing which shows the friction stirring process of the joining method which concerns on 1st embodiment. It is sectional drawing which shows the friction stirring process after the joining method which concerns on 1st embodiment. It is sectional drawing which shows the friction stirring process of the joining method which concerns on 2nd embodiment of this invention. It is a perspective view which shows the butt | matching process of the joining method which concerns on 3rd embodiment of this invention. It is a perspective view which shows the welding process of the joining method which concerns on 3rd embodiment. It is sectional drawing which shows the friction stirring process (installation process to a mount frame) of the joining method which concerns on 3rd embodiment. It is a perspective view which shows the friction stirring process of the joining method which concerns on 3rd embodiment. It is sectional drawing which shows the friction stirring process of the joining method which concerns on 3rd embodiment.

[First embodiment]
A joining method according to a 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 butted in a T shape and joined. The joining method according to the first embodiment includes a butt process, a welding process, and a friction stirring process. In the description, “front surface” means a surface opposite to the “back surface”.

  The first metal member 1 is a plate-like metal member. The material of the first metal member 1 is appropriately selected from metals capable of friction stirring such as aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, magnesium, magnesium alloy and the like. On the back surface 1a of the first metal member 1, a concave groove 3 having a rectangular cross section composed of a bottom surface 3a and side walls 3b, 3b is formed. The concave groove 3 is extended in the extending direction of the first metal member 1. The second metal member 2 is a plate-like metal member. The plate thickness dimension of the second metal member 2 is set to be equal to or smaller than the width of the groove 3 so that the second metal member 2 fits into the groove 3. The material of the second metal member 2 may be appropriately selected from the metals that can be frictionally stirred, but is preferably the same material as that of the first metal member 1.

  As shown in FIG. 1, the butting process is a process in which the first metal member 1 and the second metal member 2 are butted in a T shape when viewed from the front. In the butting step, the second metal member 2 is fitted into the groove 3 of the first metal member 1, and the end surface 2 c of the second metal member 2 is butted against the bottom surface 3 a of the groove 3. A butted portion J (see FIG. 2) is formed by butting the bottom surface 3a of the groove 3 of the first metal member 1 and the end surface 2c of the second metal member 2.

  As shown in FIG. 2, the welding process is a process of welding and joining the inner corners. The welding process includes a first inner corner formed by the back surface 1 a of the first metal member 1 and the first side surface 2 a of the second metal member 2, the back surface 1 a of the first metal member 1, and the second metal member 2. The second inner corner formed by the two side surfaces 2b is welded. The type of welding is not particularly limited, but in the welding process according to the present embodiment, weld metals 4 and 4 are formed by performing overlay welding such as laser welding, TIG welding, and MIG welding. The welding process may be performed continuously without any gap as in the present embodiment, or may be performed intermittently so that the weld metal 4 for one inner corner is formed with a gap. After the welding process, as shown by the arrows in FIG. 2, the back surface 1 a side of the first metal member 1 becomes concave due to thermal contraction (so that the front end side of the first metal member 1 is close to the second metal member 2. ) Warp and deform. In addition, although a welding process should just be performed to at least one of a 1st inner corner and a 2nd inner corner, it can join with sufficient balance by welding to both.

  The friction stir process is a process of performing friction stir welding to the butt joint J as shown in FIGS. As shown in FIG. 3, in the friction stirring step, first, the first metal member 1 and the second metal member 2 are placed on the mounts 5 and 5. More specifically, in the friction stirring step, the second metal member 2 is inserted between the gantry 5 and 5 that are spaced apart, and the back surface 1a of the first metal member 1 is brought into contact with the gantry 5 and 5. The mounts 5 and 5 both present a rectangular parallelepiped. Chamfered portions 5a and 5a are formed in portions of the mounts 5 and 5 that face each inner corner. The shape of the chamfered portion 5a may be appropriately formed so as not to come into contact with the weld metals 4 and 4, and is a C chamfered shape in this embodiment.

  The friction stir process is a process in which the rotary tool F is inserted from the surface 1b of the first metal member 1 and friction stir welding is performed along the abutting portion J as shown in FIGS. The rotary tool F is made of, for example, tool steel, and includes a connecting portion F1 and a stirring pin F2. The connecting part F1 is a part connected to a rotating shaft of a friction stirrer (not shown). The connecting portion F1 has a columnar shape and is formed with a screw hole to which a bolt is fastened.

  The stirring pin F2 is tapered, and the length of the stirring pin F2 is larger than the plate thickness of the portion where the concave groove 3 of the first metal member 1 is formed. A spiral groove is formed on the outer peripheral surface of the stirring pin F2. In the present embodiment, in order to rotate the rotary tool F to the right, the spiral groove of the stirring pin F2 is formed in a counterclockwise direction from the proximal end toward the distal end. In other words, the spiral groove is formed counterclockwise as viewed from above when the spiral groove is traced from the proximal end to the distal end.

  In addition, when rotating the rotation tool F counterclockwise, it is preferable to form the spiral groove clockwise as it goes from the proximal end to the distal 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 proximal end to the distal end. By setting the spiral groove in this manner, the plastic fluidized metal in the friction stirring step is guided to the tip side of the stirring pin F2 by the spiral groove. Thereby, the quantity of the metal which overflows from the surface 1b of the 1st metal member 1 can be decreased.

  Further, in the friction stirring step, only the rotated stirring pin F2 is inserted into the first metal member 1, and the first metal member 1 and the connecting portion F1 are moved while being separated from each other. In other words, the friction stir welding is performed by tracing the butted portion J with the base end portion of the stirring pin F2 exposed. A plasticized region W is formed in the movement locus of the rotary tool F by hardening of the friction-stirred metal.

  The insertion depth of the rotary tool F is preferably set so that the tip of the stirring pin F2 reaches the abutting portion J. That is, it is preferable to perform friction stir welding by bringing the rotary tool F into contact with the first metal member 1 and the second metal member 2. When setting so that the tip of the agitation pin F2 does not reach the butting portion J, that is, when the agitation pin F2 is brought into contact only with the first metal member 1, the frictional heat between the first metal member 1 and the agitation pin F2 As a result, the metal around the butted portion J is plastically fluidized so that the first metal member 1 and the second metal member 2 are joined.

  In the friction stir process, as shown by the arrow in FIG. 4, the first metal member 1 is moved to the surface 1 b side (so that the front end side of the first metal member 1 is separated from the second metal member 2) by friction heat during friction stir welding. ). Thereby, the deformation | transformation by the welding heat at the time of welding can be corrected, and as shown in FIG. 6, the 1st metal member 1 becomes flat (a substantially flat also is included). When the friction stirring step is completed, it is preferable to perform a burr removing step for removing burrs generated on the surface 1b of the first metal member 1. Thereby, the surface 1b of the 1st metal member 1 can be finished finely.

  According to the joining method which concerns on 1st embodiment demonstrated above, since it welds to an inner corner, the position shift and separation | spacing of the 1st metal member 1 and the 2nd metal member 2 at the time of a friction stirring process are prevented. Can do. Thereby, generation | occurrence | production of the joining defect accompanying the position shift and separation | spacing of the 1st metal member 1 and the 2nd metal member 2 can be prevented. Moreover, although it deform | transforms so that the back surface 1a side of the 1st metal member 1 may become concave by the welding heat at the time of welding, the said deformation | transformation can be corrected with the frictional heat at the time of friction stir welding.

  Moreover, since the groove 3 is formed in the first metal member 1 of the present embodiment, the thickness of the portion of the first metal member 1 where the groove 3 is formed is greater than the thickness of the other portions. Is also thin. Therefore, in the friction stirring process of the present embodiment, the depth at which the stirring pin G2 is inserted can be reduced as compared with the case where the concave groove 3 is not formed, so that a large load is not applied to the friction stirring device. J friction stir welding can be performed.

  The type of welding in the welding process is not particularly limited, but the inner corner can be easily and reliably welded by performing laser welding, TIG welding, or MIG welding as in the present embodiment.

  Further, the bases 5 and 5 of the present embodiment have chamfered portions 5a and 5a formed at portions facing the inner corners. When the first metal member 1 and the second metal member 2 are arranged on the gantry 5, the weld metal 4 and the gantry 5 may interfere with each other and the first metal member 1 and the second metal member 2 may be lifted from the gantry 5. However, according to this embodiment, it is possible to prevent the weld metals 4 and 4 and the mount 5 from interfering with each other.

  Moreover, in the friction stirring process of this embodiment, using the rotary tool F, friction is performed with only the stirring pin F2 in contact with the first metal member 1 and the second metal member 2 (or only the first metal member 1). Since the stir welding is performed, the friction stir welding can be performed to a deep position in a state where a large load is not applied to the friction stirrer. Therefore, the rotary tool F is particularly advantageous when the thickness of the first metal member 1 is large. Moreover, since the rotation tool F can make the width | variety of the plasticization area | region W small compared with the case where a shoulder part is pushed in, it is advantageous also when the plate | board thickness of the 2nd metal member 2 is thin.

[Second Embodiment]
Next, the joining method according to the second embodiment of the present invention will be described. As shown in FIG. 7, the joining method according to the second embodiment differs from the first embodiment in that a rotating tool G is used. In the joining method according to the second embodiment, a butt process, a welding process, and a friction stirring process are performed. Since the butting process and the welding process are the same as those in the first embodiment, the description thereof is omitted.

  The rotary tool G is made of, for example, tool steel, and includes a columnar shoulder portion G1 and a stirring pin G2 depending from the shoulder portion G1. A spiral groove is formed on the outer peripheral surface of the stirring pin G2. In the friction stirring step, the rotary tool G is moved along the abutting portion J while being inserted into the surface 1 b of the first metal member 1. In the friction stirring step, the lower end surface of the shoulder portion G1 is pushed into the first metal member 1 by about several millimeters to perform friction stirring. The insertion depth of the stirring pin G2 is not particularly limited as long as the abutting portion J can be friction stir welded, but is preferably set so that the tip of the agitating pin G2 reaches the abutting portion J as in this embodiment. That is, it is preferable to perform friction stir welding by bringing the rotary tool G into contact with the first metal member 1 and the second metal member 2.

  When setting so that the tip of the stirring pin G2 does not reach the butting portion J, that is, when the stirring pin G2 contacts only the first metal member 1, the frictional heat between the first metal member 1 and the stirring pin G2 As a result, the metal around the butted portion J is plastically fluidized so that the first metal member 1 and the second metal member 2 are joined. In addition, although the outer diameter (diameter) of the shoulder part G1 may be set suitably, it is good to form smaller than the width | variety of the ditch | groove 3. FIG.

  According to the joining method according to the second embodiment described above, an effect substantially equivalent to that of the first embodiment can be obtained. Moreover, since the shoulder part G1 is pushed into the surface 1b of the first metal member 1, the plastic fluidized material is pressed by the shoulder part G1, and burrs can be reduced. Moreover, since the groove | channel which generate | occur | produces in the surface 1b by the plasticization area | region W can be made small if the pushing amount of the rotation tool G is made small, surface treatment etc. become easy and finishes the surface 1b of the 1st metal member 1 neatly. be able to. Moreover, since the outer diameter (diameter) of the shoulder part G1 is formed smaller than the width of the concave groove 3, the material plastically fluidized by the stirring pin G2 of the rotary tool G is the first metal member 1 and the second metal member 2. Can be prevented from jumping out from the inner corner.

[Third embodiment]
Next, the joining method according to the third embodiment of the present invention will be described. In the joining method according to the third embodiment, a butt process, a welding process, and a friction stirring process are performed. As shown in FIG.8 and FIG.9, in the joining method which concerns on 3rd embodiment, the 1st metal member 21, the 2nd metal member 22, and the 3rd metal member 23 are face-to-face-shaped and joined. It is different from the first embodiment.

  The first metal member 21 and the third metal member 23 are plate-like metal members. The materials of the first metal member 21 and the third metal member 23 are appropriately selected from metals capable of friction stirring such as aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, magnesium, and magnesium alloy. The corner on the back surface 21a side of the first metal member 21 is cut out in a rectangular shape in front view. That is, the back surface 21a of the first metal member 21 has a recess 21f composed of a bottom surface 21d and a side wall 21e. Moreover, the corner | angular part by the side of the back surface 23a of the 3rd metal member 23 is notched by the rectangular shape of front view. That is, the back surface 23a of the third metal member 23 has a recess 23f composed of a bottom surface 23d and a side wall 23e. As will be described later, a concave groove 24 is formed by the concave portion 21f and the concave portion 23f by abutting the first metal member 21 and the third metal member 23 together. In addition, it is preferable that the recessed part 21f and the recessed part 23f are equivalent dimensions. That is, it is preferable that the bottom surface 21 d of the first metal member 21 and the bottom surface 23 d of the third metal member 23 are flush with each other in a state where the first metal member 21 and the third metal member 23 are abutted.

  The second metal member 22 is a plate-like metal member. The plate thickness dimension of the second metal member 22 is set equal to or smaller than the width of the groove 24 so that the second metal member 22 fits into the groove 24. The material of the second metal member 22 may be appropriately selected from the metals that can be frictionally stirred, but is preferably the same material as the first metal member 21 and the third metal member 23.

In the butting step, the first butted portion J1 is formed by butting the end surface 21c on the side where the recess 21f of the first metal member 21 is formed and the end surface 23c on the side where the recess 23f of the third metal member 23 is formed. In a state where the first metal member 21 and the third metal member 23 are abutted against each other, a concave groove having a rectangular cross section is formed on the back surfaces 21a and 23a (around the first abutting portion J1) of the first metal member 21 and the third metal member 23. 24 is formed. The concave groove 24 extends in the extending direction of the first metal member 21 and the third metal member 23.
In the butting process, the end face 22c of the second metal member 22 is butted against the first butting part J1 to form the second butting part J2 (see FIG. 9). That is, the end surface 22 c of the second metal member 22 is abutted against the groove 24 formed on the back surface 21 a of the first metal member 21 and the back surface 23 a of the third metal member 23.

  As shown in FIG. 9, the welding process is a process of welding and joining the inner corners. The welding process is a process of welding the first inner corner between the back surface 21 a of the first metal member 21 and the first side surface 22 a of the second metal member 22. The welding process is a process of welding the second inner corner between the back surface 23 a of the third metal member 23 and the second side surface 22 b of the second metal member 22. The type of welding is not particularly limited, but in the welding process according to the present embodiment, weld metals 4 and 4 are formed by performing overlay welding such as laser welding, TIG welding, and MIG welding. The welding process may be performed continuously without any gap as in the present embodiment, or may be performed intermittently so that the weld metal 4 for one inner corner is formed with a gap. After the welding process, as shown by the arrows in FIG. 9, the back surfaces 21 a and 23 a of the first metal member 21 and the third metal member 23 become concave due to thermal contraction (the first metal member 21 and the third metal member). The tip 23 is deformed in a warped manner (so that the front end side of the second member 23 comes close to the second metal member 22).

  As shown in FIGS. 10 to 12, the friction stirring step is a step of friction stir welding the first butting portion J1 and the second butting portion J2. In the friction stirring step, first, as shown in FIG. 10, the first metal member 21, the second metal member 22 and the third metal member joined to the pedestals 5 and 5 with the weld metals 4 and 4 in the same manner as in the first embodiment. A metal member 23 is disposed.

  As shown in FIGS. 11 and 12, the friction stirring step is performed by inserting the rotary tool F from the surface 21b side of the first metal member 21 and the surface 23b side of the third metal member 23 and along the first abutting portion J1. This is a step of friction stir welding. The rotary tool F is made of, for example, tool steel, and includes a connecting portion F1 and a stirring pin F2. The connecting part F1 is a part connected to a rotating shaft of a friction stirrer (not shown). The connecting portion F1 has a columnar shape and is formed with a screw hole to which a bolt is fastened. In the friction stirring step, only the rotated stirring pin F2 is inserted into the first metal member 21 and the third metal member 23, and the first metal member 21, the third metal member 23 and the connecting portion F1 are moved while being separated from each other. In other words, the friction stir welding is performed by tracing the first abutting portion J1 with the base end portion of the stirring pin F2 exposed. A plasticized region W is formed in the movement locus of the rotary tool F by hardening of the friction-stirred metal.

The insertion depth of the rotary tool F is preferably set so that the tip of the stirring pin F2 reaches the second butting portion J2. That is, it is preferable to perform the friction stir welding in a state where the stirring pin F2 is in contact with the first metal member 21, the second metal member 22, and the third metal member 23.
When setting so that the tip of the stirring pin F2 does not reach the second butting portion J2, that is, when the stirring pin F2 contacts only the first metal member 21 and the third metal member 23, the first metal member 21 The metal around the second butted portion J2 is plastically fluidized by frictional heat between the third metal member 23 and the stirring pin F2, and the first metal member 21, the second metal member 22, and the third metal member 23 are joined. Like that.

  Further, in the friction stirring step, as shown by the arrows in FIG. 11, the first metal member 21 and the third metal member 23 are brought into contact with the surfaces 21b and 23b (the first metal member 21 and the third metal member 23) by the frictional heat during the friction stir welding. So that the tip end side of the metal member 23 is separated from the second metal member 22). Thereby, the deformation | transformation by the welding heat at the time of welding can be corrected, and the 1st metal member 21 and the 3rd metal member 23 become flat (a substantially flat is also included). When the friction stirring step is completed, it is preferable to perform a burr removing step for removing burrs generated on the surfaces 21b and 23b of the first metal member 21 and the third metal member 23. Thereby, the surface 21b, 23b of the 1st metal member 21 and the 3rd metal member 23 can be finished finely.

  In addition, the friction stirring process of 2nd embodiment can also be performed with respect to the butt | matching process and welding process of 3rd embodiment. That is, after the first metal member 21, the second metal member 22, and the third metal member 23 are butted in a T shape in front view and the inner corner is welded, the rotary tool G having the cylindrical shoulder portion G1 is used. The first butted portion J1 and the second butted portion J2 may be friction stir welded.

  According to the joining method which concerns on 3rd embodiment demonstrated above, since it welds to an inner corner, the position of the 1st metal member 21, the 2nd metal member 22, and the 3rd metal member 23 at the time of a friction stirring process Deviation and separation can be prevented. Thereby, generation | occurrence | production of the joining defect accompanying the position shift and separation | spacing of the 1st metal member 21, the 2nd metal member 22, and the 3rd metal member 23 can be prevented. Moreover, although it deform | transforms so that the back surface 21a, 23a side of the 1st metal member 21 and the 3rd metal member 23 may become concave by the welding heat at the time of welding, the said deformation | transformation can be corrected with the friction heat at the time of friction stir welding. .

  Moreover, since the concave groove 24 is formed in the first metal member 21 and the third metal member 23 of the present embodiment, the thickness of the portion where the concave groove 24 is formed is greater than the thickness of the other portions. Is also thin. Therefore, in the friction stir process of the present embodiment, the depth at which the stir pin F2 is inserted can be reduced compared to the case where the concave groove 24 is not formed, so that a large load is not applied to the friction stirrer. Friction stir welding of the butt J1 and the second butt J2 can be performed.

  The type of welding in the welding process is not particularly limited, but the inner corner can be easily and reliably welded by performing laser welding, TIG welding, or MIG welding as in the present embodiment.

  Further, the bases 5 and 5 of the present embodiment have chamfered portions 5a and 5a formed at portions facing the inner corners. When the first metal member 21, the second metal member 22, and the third metal member 23 are arranged on the gantry 5, 5, the weld metal 4, 4 interferes with the gantry 5 and the first metal member 21, the second metal Although the member 22 and the third metal member 23 may be lifted from the gantry 5, according to the present embodiment, it is possible to prevent the weld metals 4 and 4 and the gantry 5 from interfering with each other.

  Moreover, in the friction stirring process of this embodiment, using the rotary tool F, only the stirring pin F2 is used for the first metal member 21, the second metal member 22, and the third metal member 23 (or the first metal member 21 and the third metal member). Since the friction stir welding is performed in contact with only the metal member 23), the friction stir welding can be performed to a deep position without applying a large load to the friction stirrer. Therefore, the rotary tool F is particularly advantageous when the plate thickness of the first metal member 21 and the third metal member 23 is large. Moreover, since the rotation tool F can make the width | variety of the plasticization area | region W small compared with the case where a shoulder part is pushed in, it is advantageous also when the plate | board thickness of the 2nd metal member 22 is thin.

  Although the embodiments of the present invention have been described above, design changes can be made as appropriate without departing from the spirit of the present invention.

1, 21 First metal member 1a, 21a Back surface 1b, 21b Surface 2, 22 Second metal member 2a, 22a First side surface 2b, 22b Second side surface 23 Third metal member 23a Back surface 23b Surface 3, 24 Concave groove 4 Welding Metal 5 Base 5a Chamfered portion J Butting portion J1 First butting portion J2 Second butting portion F Rotating tool F1 Connecting portion F2 Stirring pin G Rotating tool G1 Shoulder portion G2 Stirring pin

Claims (14)

A butting step of inserting an end face of the plate-like second metal member into the concave groove of the first metal member having a plate-like shape and having a concave groove on the back surface, and abutting the end face against the bottom surface of the concave groove;
A welding step of welding the inner corner formed by the back surface of the first metal member and the side surface of the second metal member;
A friction stirring step of inserting a stirring pin of a rotary tool from the surface side of the first metal member, relatively moving the rotary tool along the concave groove, and friction stir welding the butt portion;
In the friction stirring step, the abutting portion is friction stir welded in a state where the stirring pin is in contact with only the first metal member or both the first metal member and the second metal member. Joining method.   In the friction stirring step, only the stirring pin of the rotating tool is inserted from the surface of the first metal member, and only the stirring pin is only the first metal member, or the first metal member and the second metal member. The joining method according to claim 1, wherein the butted portion is friction stir welded in a state where both are brought into contact with each other.   2. The rotating tool includes a shoulder portion having a columnar shape and a stirring pin hanging from the shoulder portion, and the diameter of the shoulder portion is set smaller than the width of the concave groove. Joining method.   4. The joining method according to claim 1, wherein in the welding step, build-up welding is continuously performed on the inner corner in one pass.   The joining method according to any one of claims 1 to 3, wherein, in the welding step, build-up welding is intermittently performed with a gap between the inner corners.   6. The joining method according to claim 1, wherein laser welding, MIG welding, or TIG welding is performed in the welding step. In the friction stirring step,
A pair of mounts are arranged on both sides of the second metal member,
The joining method according to any one of claims 1 to 6, wherein a chamfered portion is formed in a portion of the gantry facing the inner corner. A first butt having a concave groove by abutting the end surface of the first metal member having a plate shape and notching the corner portion on the back surface and the end surface of the third metal member having a plate shape and notched corner portion on the back surface side. A step of forming a second butted portion by inserting an end surface of a plate-like second metal member into the concave groove and abutting the end surface against the bottom surface of the concave groove,
The inner corner formed by the back surface of the first metal member and the side surface of the second metal member is welded and formed by the back surface of the third metal member and the side surface of the second metal member. A welding process for welding the inner corner;
A stirring pin of a rotary tool is inserted from the surface side of the first metal member and the surface side of the third metal member, and the rotary tool is relatively moved along the concave groove, so that the first butting portion and the first metal A friction stir process for friction stir welding the two butted portions,
In the friction stirring step, the stirring pin is in contact with only the first metal member and the third metal member, or in contact with the first metal member, the third metal member, and the second metal member. A joining method comprising friction stir welding of one butting portion and the second butting portion.   In the friction stirring step, only the stirring pin of the rotary tool is inserted from the surfaces of the first metal member and the third metal member, and only the stirring pin is only the first metal member and the third metal member, or The friction stir welding is performed on the first butted portion and the second butted portion in contact with the first metal member, the third metal member, and the second metal member. Joining method.   The rotary tool includes a shoulder portion having a columnar shape and a stirring pin hanging from the shoulder portion, and the diameter of the shoulder portion is set to be smaller than the width of the concave groove. Joining method.   11. The joining method according to claim 8, wherein in the welding step, build-up welding is continuously performed on the inner corner in one pass.   The joining method according to any one of claims 8 to 10, wherein, in the welding step, build-up welding is intermittently performed with a gap between the inner corners.   The joining method according to any one of claims 8 to 12, wherein in the welding step, laser welding, MIG welding, or TIG welding is performed. In the friction stirring step,
A pair of mounts are arranged on both sides of the second metal member,
The joining method according to any one of claims 8 to 13, wherein a chamfered portion is formed in a portion of the gantry facing the inner corner.

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