JP2018001215A - Joining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining method capable of preventing positional deviation relative to each other of metal members and separation from each other of the metal members, correcting deformation of the metal members, preventing occurrence of burrs on a surface of a first metal member, as well as reducing a load applied to the frictional agitation device during frictional agitation joining.SOLUTION: A joining method comprises: an abutment step for abutting a rear surface 1a of a first metal member 1 in a planar shape, having a recessed groove in a front surface 1b, and an end surface 2c of a second metal member 2 in a planar shape to form an abutting part J; a welding step for welding an inner corner formed of the rear surface 1a of the first metal member 1 and a first side surface 2a and a second side surface 2b of the second metal member 2; and a frictional agitation step for performing frictional agitation joining to the abutting part J by relatively moving a rotary tool G along the recessed groove. In the frictional agitation step, in a state with the shoulder part G1 of the rotary tool G separated from a bottom surface 3a of the recessed groove, burrs V generated from the first metal member 1 are depressed by the shoulder part G1.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.

  Moreover, in the conventional joining method, since the lower end surface of the shoulder part of a rotary tool is pushed into the surface of a 1st metal member and a friction stirring process is performed, a burr | flash generate | occur | produces on the surface of a 1st metal member. For this reason, a burr removal process for removing the burr must be performed. Moreover, since the lower end surface of the shoulder portion of the rotary tool is pushed into the surface of the first metal member to perform the friction stirring step, there is a problem that the load applied to the friction stirring device increases.

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 addition, the present invention is characterized by providing a joining method that can prevent the generation of burrs on the surface of the first metal member and can reduce the load applied to the friction stirrer.

  In order to solve such problems, the present invention provides a butting step in which the back surface of the first metal member having a plate shape and having a concave groove on the surface and the end surface of the plate-shaped second metal member are butted to form a butting portion. 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 a rotating tool from the surface side of the first metal member to the concave groove. A friction stirring step of inserting a stirring pin, relatively moving the rotary tool along the concave groove, and friction stir welding the butt portion, the rotary tool including a shoulder portion having a cylindrical shape and the A stirring pin that hangs down from a shoulder portion, the diameter of the shoulder portion is set smaller than the width of the concave groove, and in the friction stirring step, the shoulder portion of the rotary tool is inserted into the concave groove, The shoulder part of the concave groove In a state of being spaced apart from the face, while holding the burr generated from the first metal member by said shoulder portion, characterized by friction stir welding the butted portion.

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.
Further, according to such a method, in the friction stirring step, a narrow space is formed on the bottom surface of the groove, both side walls of the groove and the lower end surface of the shoulder portion, so that the burr is prevented from being scattered and the groove Burrs can be deposited on the bottom surface. Thereby, it can prevent that a burr | flash generate | occur | produces on the surface of a 1st metal member. Moreover, since a shoulder part is not pushed in into the bottom face of a ditch | groove, the load concerning a friction stirrer can be made small.

  The plate thickness of the second metal member is preferably set larger than the width of the concave groove. Thereby, the material of the metal member plastically fluidized by the stirring pin of the rotary tool can be reliably prevented from jumping out from the abutting portion between the back surface of the first metal member and the end surface of the plate-like second metal member. .

  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 face of the first metal member that has a cut-out corner on the surface side and a plate-like third face that has a cut-out corner on the surface side. A first abutting portion having a concave groove is formed by abutting with the end surface of the metal member, and a second abutting is performed by abutting the back surface of the first metal member and the back surface of the third metal member with the end surface of the second metal member. Welding the first inner corner formed by the butting step for forming the 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 first metal member. A welding process for welding a second inner corner formed by the side surfaces of the two metal members, and stirring of the rotary tool from the surface side of the first metal member and the surface side of the third metal member to the concave groove Insert a pin and move the rotary tool relative to the groove. A friction stir step for friction stir welding the first butting portion and the second butting portion, and the rotating tool has a shoulder portion having a columnar shape and a stirring pin depending from the shoulder portion, and The diameter of the shoulder portion is set smaller than the width of the groove, and in the friction stirring step, the shoulder portion of the rotary tool is inserted into the groove, and the shoulder portion is separated from the bottom surface of the groove. In this state, the first abutting portion and the second abutting portion are friction stir welded while pressing the burr generated from the first metal member and the third metal member with the shoulder portion.

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.
Further, according to such a method, in the friction stirring step, a narrow space is formed on the bottom surface of the groove, both side walls of the groove and the lower end surface of the shoulder portion, so that the burr is prevented from being scattered and the groove Burrs can be deposited on the bottom surface. Thereby, it can prevent that a burr | flash generate | occur | produces on the surface of a 1st metal member, and the surface of a 3rd metal member. Moreover, since a shoulder part is not pushed in into the bottom face of a ditch | groove, the load concerning a friction stirrer can be made small.

According to the joining method according to the present invention, it is possible to prevent misalignment between metal members and separation of metal members during friction stir welding. Moreover, according to the joining method which concerns on this invention, a deformation | transformation of a metal member can be corrected.
Moreover, according to the joining method which concerns on this invention, while being able to prevent a burr | flash generate | occur | producing on the surface of a 1st metal member, the load concerning a friction stirrer can be made small.

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 a perspective view which shows the butt | matching process of the joining method which concerns on 2nd embodiment of this invention. It is a perspective view which shows the welding process of the joining method which concerns on 2nd embodiment. It is sectional drawing which shows the friction stirring process (installation process to a mount frame) of the joining method which concerns on 2nd embodiment. It is sectional drawing which shows the friction stirring process of the joining method which concerns on 2nd 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. A concave groove 3 having a rectangular cross section is formed on the surface of the first metal member 1. 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. Although the plate | board thickness dimension of the 2nd metal member 2 should just be set suitably, it is formed larger than the width | variety of the ditch | groove 3 in this embodiment. 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 step is a step of butting the back surface 1 a of the first metal member 1 and the end surface 2 c of the second metal member 2 in a T shape when viewed from the front. In the butting step, the end surface 2c of the second metal member 2 is butted against the corresponding position of the groove 3. A butted portion J is formed by butting the back surface 1 a of the first metal member 1 and the end surface 2 c 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.

  As shown in FIGS. 4 and 5, the friction stirring step is a step of inserting the shoulder portion G <b> 1 of the rotary tool G into the groove 3 and friction stir welding the butted portion J. The rotary tool G is made of, for example, tool steel, and includes a columnar shoulder portion G1 and a stirring pin G2 that hangs down from the lower end surface G1a of the shoulder portion G1. The outer diameter of the shoulder portion G <b> 1 is formed slightly smaller than the width of the concave groove 3. The outer diameter of the shoulder portion G1 may be set so that the outer peripheral surface of the shoulder portion G1 and the side walls 3b, 3b of the concave groove 3 are in contact with each other. However, when performing the friction stirring step, the outer peripheral surface of the shoulder portion G1 And the side walls 3b, 3b of the groove 3 are preferably of a size that allows relative movement with a slight gap.

  The stirring pin G2 is tapered. A spiral groove is formed on the outer peripheral surface of the stirring pin G2. In this embodiment, in order to rotate the rotary tool G to the right, the spiral groove of the stirring pin G2 is formed counterclockwise as it goes from the proximal end to 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 G 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 G2 by the spiral groove. Thereby, the quantity of the metal which overflows from the bottom face 3a of the ditch | groove 3 can be decreased.

  In the friction stirring step, the stirring pin G2 of the rotary tool G is inserted into the center of the bottom surface 3a of the concave groove 3 from the surface 1b side of the first metal member 1, and the rotary tool G is moved along the abutting portion J (concave groove 3). Move relative. The insertion depth of the rotary tool G may be set as appropriate, but in this embodiment, the stirring pin G2 reaches the second metal member 2, that is, the first metal member 1 and the second metal member 2 are stirred. Friction stir welding is performed with the pin G2 in contact. A plasticized region W is formed in the movement locus of the rotary tool G.

  The agitation pin G2 may be set so as not to reach the second metal member 2. That is, in the friction stirring step, the insertion depth of the stirring pin G2 may be set so that only the first metal member 1 and the stirring pin G2 are in contact with each other. Thus, when setting so that the front-end | tip of the stirring pin G2 may not reach the 2nd metal member 2, the metal around the butt | matching part J plastically flows by the frictional heat of the 1st metal member 1 and the stirring pin G2. And the first metal member 1 and the second metal member 2 are joined.

  Further, in the friction stirring step, the lower end surface G1a of the shoulder portion G1 is set apart from the bottom surface 3a of the groove 3 and lower than the surface 1b of the first metal member 1. That is, in the friction stirring step, friction stir welding is performed while pressing the burr V generated by the friction stirring with the lower end surface G1a of the shoulder portion G1. “The state in which the shoulder portion is separated from the bottom surface of the concave groove” in the claims means that the lower end surface G1a of the shoulder portion G1 is separated from the bottom surface 3a of the concave groove 3 before the burr V is generated. It is. In addition, the phrase “while pressing the burr generated from the first metal member with the shoulder portion” in the claims means that the accumulated burr V and the lower end surface G1a of the shoulder portion G1 are in contact with each other. This means that the surface (upper surface) is pressed by the lower end surface G1a of the shoulder portion G1.

  A burr V is generated on the bottom surface 3a of the groove 3 by the friction stir process. However, a narrow space (rectangular cross section) formed by the bottom surface 3a of the groove 3, the side walls 3b and 3b of the groove 3, and the lower end surface G1a of the shoulder portion G1. The burr V is confined in the closed space), and the burr V is deposited on the bottom surface 3a. As shown in FIG. 6, the burr V is accommodated in the groove 3 and the surface (upper surface) of the burr V is pressed by the lower end surface G1a of the shoulder portion G1 and becomes substantially flat.

  According to the joining method according to the present embodiment described above, since welding is performed on the inner corner, it is possible to prevent displacement and separation between the first metal member 1 and the second metal member 2 during the friction stirring step. it can. 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.

  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.

  Further, according to the joining method according to the present embodiment, a narrow space is formed by the bottom surface 3a of the recessed groove 3, the side walls 3b and 3b of the recessed groove 3, and the lower end surface G1a of the shoulder portion G1 when performing the friction stirring step. Therefore, it is possible to prevent the burrs V from being scattered and to deposit the burrs V on the bottom surface 3 a of the groove 3. Thereby, generation | occurrence | production of the burr | flash V on the surface 1b of the 1st metal member 1 can be prevented. Therefore, the surface treatment such as the burr removing process on the surface 1b of the first metal member 1 can be omitted.

  Moreover, according to the joining method which concerns on this embodiment, since the shoulder part G1 is not pushed in into the bottom face 3a of the ditch | groove 3, the load concerning a friction stirrer can be made small. Moreover, in this embodiment, since the plate | board thickness dimension of the 2nd metal member 2 is set larger than the width | variety of the ditch | groove 3, the material plastically fluidized with the stirring pin G2 of the rotary tool G is the 1st metal member. 1 can be reliably prevented from jumping out from the abutting portion J between the back surface 1a of the plate 1 and the end surface 2c of the plate-like second metal member 2.

[Second Embodiment]
Next, the joining method according to the second embodiment of the present invention will be described. In the joining method according to the second embodiment, a butt process, a welding process, and a friction stirring process are performed. As shown in FIG.7 and FIG.8, in the joining method which concerns on 2nd 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 surface 21b side of the first metal member 21 is cut out in a rectangular shape in front view. That is, the surface 21b 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 surface 23b of the 3rd metal member 23 is notched in rectangular shape by the front view. That is, the surface 23b 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. Although the plate | board thickness dimension of the 2nd metal member 2 should just be set suitably, it is formed larger than the width | variety of the ditch | groove 24 in this embodiment. 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, grooves 21 having a rectangular cross section are formed on the surfaces 21b and 23b (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. That is, the end surface 22 c of the second metal member 22 is abutted against 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. 8, 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. 8, 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 tip end side of the second metal member 22 is close to the second metal member 22).

  As shown in FIGS. 9 and 10, the friction stirring step is a step of friction stir welding the first butting portion J1 and the second butting portion J2 using the rotary tool G. In the friction stirring step, first, as shown in FIG. 9, the first metal member 21, the second metal member 22 and the third metal member joined to the mounts 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.

In the friction stirring step, as shown in FIG. 10, the stirring pin G2 of the rotary tool G is inserted into the center of the groove 24 from the surface 21b side of the first metal member 21 and the surface 23b side of the third metal member 23, The rotary tool G is relatively moved along the abutting portion J1. A plasticized region W is formed in the movement locus of the rotary tool G. The insertion depth of the rotating tool G is preferably set so that the tip of the stirring pin G2 reaches the second butting portion J2. That is, it is preferable to perform the friction stir welding in a state where the stirring pin G2 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 G2 does not reach the second butting portion J2, that is, when the stirring pin G2 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 G2, 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, the lower end surface G1a of the shoulder portion G1 is separated from the bottom surfaces 21d and 23d forming the concave groove 24, and from the surface 21b of the first metal member 21 and the surface 23b of the third metal member 23. Is also set to a low position. That is, in the friction stirring step, friction stir welding is performed while pressing the burr V generated by the friction stirring with the lower end surface G1a of the shoulder portion G1.

  According to the joining method which concerns on 2nd 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. . Thereby, the surfaces 21b and 23b of the first metal member 21 and the third metal member 23 can be flattened.

  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.

  Further, according to the joining method according to the present embodiment, when the friction stirring step is performed, the bottom surface (bottom surface 21d, 23d) of the concave groove 24, the side wall (side wall 21e, 23e) of the concave groove 24, and the shoulder portion G1. Since a narrow space is formed at the end face G1a, it is possible to prevent the burrs V from scattering and to deposit the burrs V on the bottom surfaces (bottom surfaces 21d, 23d) of the concave grooves 24. Thereby, it can prevent that the burr | flash V generate | occur | produces on the surfaces 21b and 23b of the 1st metal member 21 and the 3rd metal member 23. FIG. Therefore, surface treatments such as a burr removing step on the surfaces 21b and 23b of the first metal member 21 and the third metal member 23 can be omitted.

  Moreover, according to the joining method which concerns on this embodiment, since the shoulder part G1 is not pushed into the bottom face (bottom face 21d, 23d) of the ditch | groove 24, the load concerning a friction stirrer can be made small. Moreover, in this embodiment, since the plate | board thickness dimension of the 2nd metal member 22 is set larger than the width | variety of the concave groove 24, the material plastic-fluidized with the stirring pin G2 of the rotary tool G is the 1st metal member. 21 can be reliably prevented from jumping out from the second butted portion J2 of the back surface 21a of the 21 and the back surface 23a of the third metal member 23 and the end surface 22c of the plate-like second metal member 22.

  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 G Rotating tool G1 Shoulder portion G2 Stirring pin

Claims (12)

A butting step of forming a butting portion by butting the back surface of the first metal member having a plate shape and having a concave groove on the surface and the end surface of the plate-like second 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;
A friction stirring step of inserting a stirring pin of a rotary tool into the concave groove from the surface side of the first metal member, moving the rotary tool relatively along the concave groove, and friction stir welding the butted portion; Including
The rotating tool has a shoulder portion that has a cylindrical shape and a stirring pin that hangs down from the shoulder portion, and sets the diameter of the shoulder portion to be smaller than the width of the concave groove,
In the friction stirring step, the shoulder portion of the rotating tool is inserted into the groove, and the burr generated from the first metal member in the state where the shoulder portion is separated from the bottom surface of the groove is the shoulder portion. The joining method is characterized in that the abutting portion is friction stir welded while being held down.   The joining method according to claim 1, wherein a plate thickness of the second metal member is set to be larger than a width of the concave groove.   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 claim 1, wherein in the welding step, build-up welding is intermittently performed with a gap between the inner corners.   5. 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 5, 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 surface side with the end surface of the third metal member having a plate shape and notched corner portion on the surface side And a butting step of forming a second butting portion by butting the back surface of the first metal member and the back surface of the third metal member and the end surface of the second metal member,
The first 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 second inner corner,
A stirring pin of a rotating tool is inserted into the groove from the surface side of the first metal member and the surface side of the third metal member, and the rotating tool is relatively moved along the groove to make the first butt contact. And a friction stir process for friction stir welding the part and the second butted portion,
The rotating tool has a shoulder portion that has a cylindrical shape and a stirring pin that hangs down from the shoulder portion, and sets the diameter of the shoulder portion to be smaller than the width of the concave groove,
In the friction stirring step, the shoulder portion of the rotary tool is inserted into the groove, and the shoulder portion is separated from the bottom surface of the groove, and is generated from the first metal member and the third metal member. The first abutting portion and the second abutting portion are friction stir welded while pressing the burr to be pressed by the shoulder portion.   The joining method according to claim 7, wherein a plate thickness of the second metal member is set larger than a width of the groove.   9. The joining method according to claim 7, wherein in the welding step, build-up welding is continuously performed on the first inner corner and the second inner corner in one pass.   The joining method according to claim 7 or 8, wherein in the welding step, build-up welding is intermittently performed with a gap between the first inner corner and the second inner corner.   11. The joining method according to claim 7, 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 7 to 11, wherein a chamfered portion is formed in a portion of the gantry facing the first inner corner and the second inner corner.

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