JP4957588B2 - Joining method - Google Patents

Description

  The present invention relates to a method for joining metal members using friction stirring.

  Friction stir welding (FSW = Friction Stir Welding) is known as a method for joining metal members. Friction stir welding is a process of rotating a rotating tool along the abutting portion between metal members, and plastically flowing the metal at the abutting portion by frictional heat between the rotating tool and the metal member, so that the metal members are solid-phased. It is what is joined. In general, the rotating tool is formed by projecting a stirring pin (probe) on the lower end surface of a cylindrical shoulder.

Here, conventionally, after performing frictional stirring on the abutting portions of a pair of metal members, it is possible to repair the defect by performing frictional stirring again on the plasticized region formed by the frictional stirring. It was done.
For example, Patent Document 1 describes a joining method in which friction stir is performed using two types of rotating tools having different shoulder diameters and stirring pin lengths on the abutting portion between a pair of metal members. ing. Such a conventional joining method is formed by one rotating tool by performing frictional stirring again on a plasticized region formed by one rotating tool using a rotating tool smaller than one rotating tool. It is possible to repair defects in the plasticized area.

Further, Patent Document 2 describes a joining method in which friction agitation is performed using two rotating tools having different sizes and rotation directions with respect to the abutting portion between a pair of metal members. Such a conventional joining method is based on the residual stress generated in the plasticized region by friction stirring with a large rotating tool, and the residual stress generated by friction stirring with a small rotating tool rotated in the opposite direction to the large rotating tool. It is possible to cancel and prevent deformation of the joint.
Japanese Patent Laid-Open No. 2002-1552 JP 2003-266181 A

  However, according to the conventional joining method described above, when the friction stir is performed again on the plasticized region formed by the friction stir performed previously, the rotating tool must be replaced, which makes the work complicated and the manufacturing is difficult. It was a cost increase.

Here, it is conceivable to repair the plasticized region of the friction stir performed previously by reciprocating the rotary tool and continuously performing the friction stir. For example, as shown in FIG. 11, the joining method is such that the rotary tool G is frictionally agitated from the surface A of the metal member 101 to be joined with the amount of pushing as Q, and then turned back at the turning point O ₁ to the plasticizing region W. On the other hand, it is conceivable to perform frictional stirring again.

However, as shown in FIG. 11, when the agitation previous friction push-in amount Q, the surface W _A of the plasticized region W, is formed below the surface A of the bonding metal member 1. Therefore, if the rotating tool G is subjected to the frictional stirring after the turning while maintaining the same height as the previous frictional stirring, the pushing amount becomes zero. Thus, when the pressure to the to-be-joined metal member 101 is insufficient, a metal member will fly at the time of friction stirring, etc., and loss will become large, and repair cannot be performed suitably.

  Then, this invention makes it a subject to provide the joining method which can repair the defect which arises in a plasticization area | region reliably in the joining method which carries out friction stirring with respect to the abutting part of a pair of metal members.

  A joining method according to the present invention that solves such a problem is a joining method in which friction stir is performed on a butted portion formed by abutting a pair of metal members, and the metal member is joined to the butted portion. The first friction stirrer step for friction stir from one side of the surface, and using the same rotary tool as the rotary tool used in the first friction stirrer step, the plasticized region formed in the first friction stirrer step On the other hand, it includes a first re-friction stirring step of performing friction stirring again at a position deeper than the first friction stirring step from one surface side of the metal member.

  According to such a joining method, the friction stir is performed again at a position deeper than the first friction stir step, in other words, the rotating tool is pushed from the surface of the plasticized region formed in the first friction stir step, and the metal member is inserted. Since the first re-friction stirring is performed while pressing, even if a cavity defect or the like is formed in the first friction stirring step, the repair can be performed reliably.

  Further, the present invention is a joining method in which friction agitation is performed on the abutting portion formed by abutting a pair of metal members, and friction agitation is performed on the abutting portion from one surface side of the metal member. Using the same rotary tool as the rotary tool used in the first friction stirring step, and the plasticizing region formed in the first friction stirring step, one of the metal members A first re-friction stirring step in which friction stirring is performed again at a position deeper than the first friction stirring step from the surface side; and a second friction stirring in which friction stirring is performed from the other surface side of the metal member to the abutting portion. And using the same rotary tool as that used in the second friction agitation step, the plasticizing region formed in the second friction agitation step is used from the other surface side of the metal member to the first surface. Repeat at a position deeper than the two-friction stirring process. Second Re friction stir step of performing friction stir comprises the plasticized region between which is formed by the first re-friction agitation step and the second re-friction stir process is characterized in that overlap.

  According to such a joining method, the friction stir is performed again at a position deeper than the first friction stirring step (second friction stirring step), in other words, the rotating tool is used in the first friction stirring step (second friction stirring step). In order to perform the first re-friction stirring (second re-friction stirring step) while pressing from the surface of the formed plasticized region and pressing the metal member, cavity defects etc. in the first friction stirring step (second friction stirring step) Even if is formed, repair can be performed reliably. Moreover, the airtightness and watertightness of a metal member can be improved more because the plasticization area | region formed by the 1st refriction stirring process and the 2nd refriction stirring process overlaps.

  Further, in the present invention, the first friction stirring step and the first refriction stirring step are continuously performed, or the second friction stirring step and the second refriction stirring step are continuously performed. preferable. According to this joining method, the working efficiency of friction stirring can be increased.

  In the present invention, a pair of tab members are arranged at both ends of the abutting portion, the friction stirring start position and the end position are set to one tab member, and the friction stirring return position is set to the other tab member. It is preferable to do. According to this joining method, it is possible to easily set the friction stirring start position, the folding position, and the end position. In addition, since the butt portion between the tab material and the metal member passes twice, even if the oxide film existing between the tab material and the metal member is caught on the metal member side by the friction stirring performed earlier, the subsequent friction stirring is performed. The oxide film can be hermetically sealed.

  Further, the present invention provides a temporary joining step of temporarily joining the abutting portion using a rotating tool smaller than the rotating tool used in the first friction stirring step before the first friction stirring step. Or a temporary joining step of temporarily joining the abutting portion using a rotary tool smaller than the rotary tool used in the second friction stirring step before the second friction stirring step. It is preferable to contain. According to this joining method, it is possible to prevent the opening of the abutting portion when performing frictional stirring.

  In the above configuration, the metal member may be a hollow member. In this case, it is preferable that a recess is formed on the abutting surface of the hollow member, and a gap is formed by the recess at the abutting portion between the hollow members. In this way, a gap is formed in the abutting portion by the recess, so that the surfaces located on one end side of the side surface of the hollow member and the surfaces located on the other end side are brought into close contact with each other. The part can be formed.

  According to the joining method according to the present invention, it is possible to reliably repair defects generated in the plasticized region when the friction stir is performed on the abutting portion between the pair of metal members.

[First embodiment]
As the best mode for carrying out the present invention, a stirring pin (probe) is inserted into the abutting portion between a pair of metal members, and while the agitating pin is rotated, friction agitation is performed on the abutting portion, A joining method for joining the members will be described. In this embodiment, as shown in FIG. 1, the case where a pair of metal member 1a, 1b is connected linearly is illustrated.
First, the metal members 1a and 1b to be joined will be described in detail, and the first tab member 2 and the second tab member 3 used when joining the metal members 1a and 1b will be described in detail.

  The metal members 1a and 1b are made of a metal material that can be frictionally stirred, such as aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, magnesium, and magnesium alloy. In the present embodiment, one metal member 1a and the other metal member 1b are formed of a metal material having the same composition. Although there is no restriction | limiting in particular in the shape and dimension of metal member 1a, 1b, It is desirable to make the thickness dimension in the butt | matching part J1 the same at least. Note that a member obtained by abutting the metal members 1 a and 1 b is also referred to as a bonded metal member 1.

  The 1st tab material 2 and the 2nd tab material 3 are arrange | positioned so that the butt | matching part J1 of the to-be-joined metal member 1 may be pinched | interposed, respectively, are attached to the to-be-joined metal member 1, and to-be-joined metal member The seam (boundary line) of the bonded metal member 1 that appears on the side surface of 1 is covered. Although there is no restriction | limiting in particular in the material of the 1st tab material 2 and the 2nd tab material 3, In this embodiment, it forms with the metal material of the same composition as the to-be-joined metal member 1. FIG. Moreover, there is no restriction | limiting in particular also in the shape and dimension of the 1st tab material 2 and the 2nd tab material 3, In this embodiment, the thickness dimension is the same as the thickness dimension of the to-be-joined metal member 1 in the butt | matching part J1. I have to.

  Here, referring to FIG. 2, a small rotating tool F (hereinafter referred to as “small rotating tool F”) used for each friction stirring and a rotating tool G (hereinafter referred to as “small rotating tool F”) that is relatively larger than the small rotating tool F. The large rotary tool G ”) will be described in detail.

  A small rotary tool F shown in FIG. 2 (a) is made of a metal material harder than the metal member 1 to be joined, such as tool steel, and projects into a shoulder portion F1 having a cylindrical shape and a lower end surface F11 of the shoulder portion F1. A stirring pin (probe) F2 is provided. The size and shape of the small rotary tool F may be set in accordance with the material and thickness of the metal member 1 to be joined, but at least smaller than the large rotary tool G (see FIG. 2B). . In this way, it is possible to perform friction stir welding with a smaller load than when the large rotary tool G is used, so it is possible to reduce the load applied to the friction stirrer, and further to the small rotary tool F. Since the moving speed (feeding speed) can be made higher than the moving speed of the large rotary tool G, the working time and cost required for the friction stir welding can be reduced.

The lower end surface F11 of the shoulder portion F1 is a portion that plays a role of pressing the plastic fluidized metal and preventing scattering to the surroundings, and is formed in a concave shape in this embodiment. There is no particular limitation on the size of the outer diameter X ₁ of the shoulder portion F1, in this embodiment, is smaller than the outer diameter Y ₁ of the shoulder portion G1 of a large rotating tool G.

The stirring pin F2 hangs down from the center of the lower end surface F11 of the shoulder portion F1, and is formed into a tapered truncated cone shape in this embodiment. In addition, a stirring blade engraved in a spiral shape is formed on the peripheral surface of the stirring pin F2. There is no particular limitation on the size of the outer diameter of the stirring pin F2, in the present embodiment, than the maximum outer diameter of the maximum outer diameter of the stirring pin G2 of (upper diameter) X ₂ is large rotating tool G (upper end diameter) Y ₂ It is small, and is smaller than the minimum outer diameter minimum outer diameter (bottom diameter) X ₃ is the stirring pin G2 (lower diameter) Y _3. The length L _A of the stirring pin F2 is smaller than the length L _B of the stirring pin G2 of the large rotating tool G.

A large rotary tool G shown in FIG. 2B is made of a metal material harder than the metal member 1 to be joined, such as tool steel, and projects into a shoulder portion G1 having a columnar shape and a lower end surface G11 of the shoulder portion G1. It comprises a stirring pin (probe) G2 provided.
The lower end surface G11 of the shoulder portion G1 is formed in a concave shape like the small rotary tool F. The stirring pin G2 hangs down from the center of the lower end surface G11 of the shoulder portion G1, and is formed into a tapered truncated cone shape in this embodiment.

  Hereinafter, the joining method according to the present embodiment will be described in detail. The bonding method according to this embodiment includes (1) a butt process, (2) a first temporary bonding process, (3) a first main bonding process, (4) a second temporary bonding process, and (5) a second main bonding process. Is included.

(1) Matching step The matching step will be described with reference to FIG. The abutting step is a step of preparing a metal member 1 to be joined and a contact member (first tab material 2 and second tab material 3) to be joined. In this embodiment, the metal members 1a and 1b to be joined are abutted. A mating process, a tab material arranging process in which the first tab material 2 and the second tab material 3 are arranged on both sides of the mating portion J1 of the bonded metal member 1, and the first tab material 2 and the second tab material 3 are welded. And a welding step of temporarily joining to the metal member 1 to be joined.

  In the abutting step, as shown in FIG. 1C, the end surfaces 11 of the metal member 1a and the metal member 1b are brought into close contact with each other, and the surface 12 of the metal member 1a and the surface 12 of the metal member 1b are flush with each other. Further, the back surface 13 of the metal member 1a and the back surface 13 of the metal member 1b are flush with each other. Further, the side surfaces 14 of the metal member 1a and the metal member 1b are flush with each other. In addition, let the surface be the surface A and the back surface among the to-be-joined metal members 1 be the back surface B.

  In the tab material arranging step, as shown in FIG. 1 (b), the first tab material 2 is arranged on one end side of the abutting portion J1 of the metal member 1 to be bonded, and the contact surface 21 is made to be the metal member 1 to be bonded. The second tab member 3 is disposed on the other end side of the abutting portion J1, and the contact surface 31 is contacted with the side surface of the metal member 1 to be joined. At this time, as shown in FIG. 1D, the surface 22 of the first tab member 2 and the surface 32 of the second tab member 3 are flush with the surface A of the metal member 1 to be joined, and the first tab. The back surface 23 of the material 2 and the back surface 33 of the second tab material 3 are flush with the back surface B of the metal member 1.

  In the welding process, as shown in FIGS. 1A and 1B, the corners 2a and 2a formed by the metal member 1 and the first tab member 2 (that is, the metal member 1 to be bonded) The joined metal member 1 and the first tab material 2 are joined by welding the corners 2a, 2a) formed by the side surface and the side surface 24 of the first tab material 2, and the joined metal member 1 and the second tab. The corners 3a and 3a formed by the material 3 (that is, the corners 3a and 3a formed by the side surface 34 of the metal member 1 and the side surface 34 of the second tab material 3) are welded. The member 1 and the second tab material 3 are joined. In addition, welding may be performed continuously over the entire length of the corners 2a and 3a, or welding may be performed intermittently.

  When the butting process described above is completed, the metal member 1 to be joined, the first tab material 2 and the second tab material 3 are placed on a frame of a friction stirrer (not shown) and a jig (not shown) such as a clamp is used. To restrain it from moving. In addition, when a welding process is abbreviate | omitted, a butt | matching process and a tab material arrangement | positioning process are performed on the mount frame of the friction stirring apparatus which is not shown in figure.

(2) First Temporary Bonding Step The first temporary bonding step is a step performed prior to the first main bonding step, and in the present embodiment, on the surface A side, the metal member to be bonded 1 and the first tab member 2 are joined. The first tab material temporary joining step for joining the abutting portion J2 with, the temporary joining step for temporarily joining the abutting portion J1 of the metal member 1 to be joined, and the abutting portion between the metal member 1 to be joined and the second tab material 3 A second tab material temporary joining step for joining J3, and a prepared hole forming step for forming a prepared hole at the friction stirring start position in the first main joining step.

In the first temporary joining step, as shown in FIG. 3, one small rotary tool F is moved so as to form a one-stroke writing movement trajectory (bead), and continuously with respect to the abutting portions J2, J1, and J3. And friction stir. That is, the stirring pin F2 (see FIG. 2A) of the small rotary tool F inserted at the friction stirring start position S _P1 is moved to the end position E _P1 without being removed halfway. In this embodiment, the first tab member 2 is provided with the friction stirring start position S _P1 and the second tab member 3 is provided with the end position E _P1 . However, the positions of the start position S _P1 and the end position E _P1 are the same. It is not intended to limit. Moreover, in this embodiment, all the rotation directions of the small rotation tool F and the large rotation tool G shall be performed by right rotation. In this way, by unifying the rotation directions of the small rotating tool F and the large rotating tool G, work labor can be omitted.

The procedure of friction stirring in the first temporary joining step of the present embodiment will be described in more detail with reference to FIGS.
First, is positioned a small rotary tool F immediately above the start position S _P1 provided in place of the first tab member 2, followed by a small rotating tool F right rotated not start stirring pin F2 is lowered while the position S _P1 Press on. The rotational speed of the small rotary tool F is set in accordance with the size and shape of the stirring pin F2, the material and thickness of the metal member 1 to be frictionally stirred, etc. It is set within the range of 2000 (rpm).

When the stirring pin F2 contacts the surface 22 of the first tab member 2, the metal around the stirring pin F2 is plastically fluidized by frictional heat, and the stirring pin F2 is inserted into the first tab member 2.
When the entire stirring pin F2 enters the first tab member 2 and the entire lower end surface F11 of the shoulder portion F1 contacts the surface 22 of the first tab member 2, as shown in FIG. While rotating, relative movement is made toward the starting point s2 of the first tab material temporary joining step.

  When the small rotary tool F is moved, the axis of the shoulder portion F1 may be slightly inclined to the rear side in the traveling direction with respect to the vertical line. The direction change of F becomes easy and a complicated movement is attained. When the small rotary tool F is moved, the metal around the stirring pin F2 is plastically fluidized at the same time, and the plastic fluidized metal is hardened again at a position away from the stirring pin F2.

  When the small rotary tool F is relatively moved and friction stirring is continuously performed up to the starting point s2 of the first tab material temporary joining step, the first tab material temporary joining step is performed without removing the small rotating tool F at the starting point s2. Transition.

  In the first tab material temporary joining step, friction agitation is performed on the abutting portion J2 between the first tab material 2 and the metal member 1 to be joined. Specifically, a friction stir route is set on the joint (boundary line) between the metal member 1 to be joined and the first tab member 2, and the small rotating tool F is relatively moved along the route. Friction stirring is performed on J2. In the present embodiment, friction stir is continuously performed from the start point s2 to the end point e2 of the first tab member temporary joining step without causing the small rotary tool F to be detached on the way.

  In addition, when the small rotary tool F is rotated to the right, there is a possibility that a fine cavity defect may occur on the left side in the traveling direction of the small rotating tool F. It is desirable to set the positions of the start point s2 and the end point e2 of the first tab material temporary joining step so that the member 1 is positioned. If it does in this way, since it becomes difficult to generate | occur | produce a cavity defect in the to-be-joined metal member 1, the high quality joined body can be obtained.

  Incidentally, when the small rotary tool F is rotated counterclockwise, there is a possibility that a fine cavity defect may occur on the right side in the traveling direction of the small rotating tool F. It is desirable to set the positions of the start point and end point of the first tab material temporary joining step so that the member 1 is positioned. Specifically, although not shown, a starting point is provided at the end point e2 when the small rotating tool F is rotated to the right, and an end point is provided at the starting point s2 when the small rotating tool F is rotated to the right. Just do it.

  In addition, when the stirring pin F2 of the small rotary tool F enters the abutting portion J2, a force for separating the bonded metal member 1 and the first tab material 2 acts, but the bonded metal member 1 and the first tab material 2 are applied. Since the corners 2a and 2b (see (b) of FIG. 1) formed by welding are temporarily joined by welding, an opening is generated between the metal member 1 to be joined and the first tab member 2. There is no.

  When the small rotary tool F reaches the end point e2 of the second tab material temporary joining process, the friction stirring is continuously performed at the end point e2 until the starting point s1 of the temporary joining process is finished, and the process proceeds to the temporary joining process as it is. To do. That is, friction stirring is continued without detaching the small rotary tool F from the end point e2 of the first tab material temporary joining process to the start point s1 of the temporary joining process, and further, the temporary rotary tool F is temporarily removed without detaching the small rotary tool F at the start point s1. Transition to the joining process. If it does in this way, the separation work of small rotation tool F in the end point e2 of the first tab material temporary joining process becomes unnecessary, and also the insertion work of small rotation tool F in the starting point s1 of the temporary joining process becomes unnecessary. Therefore, it becomes possible to improve the efficiency and speed of the preliminary joining work.

  In the temporary joining step, friction stirring is performed on the abutting portion J1 (see FIG. 3) of the metal member 1 to be joined. Specifically, a friction stir route is set on the joint (boundary line) of the metal member 1 to be joined, and the small rotary tool F is relatively moved along the route, so that the entire length of the abutting portion J1 is reached. Friction stirring is performed continuously. In the present embodiment, friction stir is continuously performed from the start point s1 to the end point e1 of the temporary joining step without causing the small rotary tool F to be detached halfway.

  When the small rotary tool F reaches the end point e1 of the temporary joining process, the friction stir is not completed at the end point e1 and the friction stirring is continuously performed up to the start point s3 of the second tab material temporary joining process. Transition to the joining process. That is, the friction stirring is continued without detaching the small rotary tool F from the end point e1 of the temporary joining process to the start point s3 of the second tab material temporary joining process, and further, the first rotation without removing the small rotary tool F at the start point s3. The process proceeds to the two-tab material temporary joining step.

  In the second tab material temporary joining step, friction agitation is performed on the abutting portion J3 between the metal member 1 to be joined and the second tab material 3. Specifically, a friction stir route is set on the joint (boundary line) between the metal member 1 to be joined and the second tab member 3, and the small rotary tool F is relatively moved along the route. Friction stirring is performed on J3. In the present embodiment, friction stir is continuously performed from the start point s3 to the end point e3 of the second tab material temporary joining step without causing the small rotary tool F to be detached on the way.

  Since the small rotary tool F is rotated to the right, the positions of the start point s3 and the end point e3 of the second tab member temporary joining step are set so that the metal member 1 to be joined is located on the right side of the traveling direction of the small rotary tool F. Set.

  Moreover, when the stirring pin F2 of the small rotary tool F enters the abutting portion J3, a force acts to separate the bonded metal member 1 and the second tab material 3, but the bonded metal member 1 and the second tab material 3 are applied. Since the corners 3 a and 3 b (see FIG. 1B) are temporarily joined by welding, no meshing occurs between the metal member 1 to be joined and the second tab member 3.

When the small rotary tool F reaches the end point e3 of the second tab material temporary joining step, the friction stir is continuously performed to the end position E _P1 provided in the second tab material 3 without ending the friction stirring at the end point e3. . In the present embodiment, the end position E _P1 is provided on the extension line of the seam (boundary line) that appears on the surface A side of the bonded metal member 1. Incidentally, the end position E _P1 is also a friction stirring start position S _M1 in a first friction stirring process described later.

When the small rotary tool F reaches the end position E _P1 , the small rotary tool F is raised while being rotated to disengage the stirring pin F2 from the end position E _P1 .

  Thus, by performing the first temporary joining step, it is possible to prevent the opening of the abutting portion J1, the abutting portion J2, and the abutting portion J3. The first temporary bonding process has been described above, but the trajectory in each process is merely an example, and other forms may be used. Further, the first tab material temporary joining step and the second tab material temporary joining step may be omitted and only the temporary joining step may be performed.

In the pilot hole forming step, as shown in FIG. 2B, the pilot hole P1 is formed at the friction stirring start position in the first friction stirring step. In the lower hole forming step according to the first temporary bonding step, forming a prepared hole P1 to S _M1 set in the second tab member 3 of the surface.

  The pilot hole P1 is provided for the purpose of reducing the insertion resistance (press-fit resistance) of the stirring pin G2 of the large rotary tool G. In this embodiment, the stirring pin F2 of the small rotary tool F ((a of FIG. ) See)) is formed by expanding the diameter of the hole H1 formed by a drill (not shown). If the punch hole H1 is used, the process of forming the pilot hole P1 can be simplified, and the working time can be shortened. Although there is no restriction | limiting in particular in the form of the pilot hole P1, In this embodiment, it is cylindrical. In addition, in this embodiment, although the pilot hole P1 is formed in the 2nd tab material 3, there is no restriction | limiting in particular in the position of the pilot hole P1, You may form in the 1st tab material 2, and the butt | matching part J2 , J3 may be preferably formed on the extended line of the joint (boundary line) of the metal member 1 to be bonded that appears on the surface A side of the metal member 1 to be bonded as in the present embodiment. .

(3) First main joining step In the first main joining step, the large rotary tool G is continuously reciprocated from the surface A of the metal member 1 to be joined along the abutting portion J1 to perform frictional stirring. That is, in the first main joining step, as shown in FIGS. 4A and 4B, the folding position O set on the first tab member 2 from the start position _SM1 set on the second tab member 3. a first friction stir step of performing friction stir until _M1, a pushing step of pushing the large rotating tool G in the folded position O _M1, friction stir from the folded position O _M1 to the end position E _M1 set in the second tab member 3 The first re-friction stirring step to be performed is included.

In the first friction stirring step, as shown in FIG. 4A and FIG. 5A, from the start position _SM1 set for the second tab material 3, the folding set for the first tab material 2 is performed. Friction stirring is continuously performed up to the position O _M1 . That is, by right rotating the large rotating tool G, after having pushed a predetermined amount shoulder G1, relatively moving the large rotating tool G toward the one end side of the butting portion J1 at the start position S _M1. The pushing amount of the large rotary tool G (distance from the surface A to the lower end of the shoulder portion G1) is set to Q ₁ (see FIG. 5B).

When the large-sized rotating tool G reaches one end of the abutting portion J1, the large rotating tool G enters the abutting portion J1 across the abutting portion J3 as it is. When the large-sized rotary tool G reaches the other end of the abutting portion J1, the large rotating tool G is positioned at the folding position O _M1 across the abutting portion J2. That is, the end position of the first friction stirring process is the turn-back position O _M1 . By the first friction stirring step, a first plasticized region W1 is formed on the surface A of the abutting portion J1. Surface W1 _A first plasticized region W1 is positioned downward by Q ₁ from the surface A to be joined metal member 1.

Pushing step, as shown in (b) of FIG. 5, when the large rotating tool G reaches the folded position O _M1, pushing a predetermined amount toward the large rotating tool G downward. And it transfers to a 1st re-friction stirring process, keeping the pushing amount.
Push-in amount of large rotating tools G in pushing step, in this embodiment, Q ₂ is pushed from the surface W1 _A first plasticized region W1. In the present embodiment, the pushing amount is set to Q ₁ > Q ₂ . Pushing amount is in this embodiment were set as described above, may be appropriately set in accordance with such a thickness and composition to be joined metal member 1, at least, than the surface W1 _A first plasticized region W1 What is necessary is just to set so that the lower end of the shoulder part G1 may be located below.

In the first re-friction stirring step, as shown in FIG. 4B and FIG. 5C, friction is continuously _generated from the turn-back position O _M1 to the end position E _M1 set on the second tab member 3. Stir. That is, the large rotary tool G is relatively moved toward the end position E _M1 while maintaining the pushing amount at the turn-back position O _M1 . After traversing butting portion J1 of one end formed butting portion J2 and the other end formed with butting portion J3 respectively, disengaging the large rotating tool G at the end position E _M1. By the first refriction stirring step, a second plasticized region W2 is formed in the abutting portion J1. The deepest portion of the second plasticization region W2 is formed at a position deeper than the deepest portion of the first plasticization region W1. The surface W2 _A second plasticized region W2 is located downward by Q _{1 +} Q ₂ minutes than the surface A of the bonding metal member 1.

Here, in the first plasticizing region W1 formed by the first friction stirring step (see FIG. 5A), the large rotary tool G is rotated to the right, and therefore the left side in the traveling direction of the large rotary tool G. There is a possibility that a tunnel-like cavity defect is formed along the longitudinal direction of the abutting portion J1.
However, according to this embodiment, since the first refriction stirring step is performed, even if the tunnel-like cavity defect occurs, the cavity defect can be filled. In addition, since the butt | joint part J1 has already been plasticized by the 1st friction stirring process, there is little possibility that a tunnel-shaped cavity defect will be formed in a 1st refriction stirring process.

Also, performed at pushing step, after pushed by push-in amount Q ₂ from the surface W1 _A first plasticized region W1, for performing the first re friction stir process, reliably repaired by presses the joint metal member 1 be able to.

Further, in this embodiment, was carried out continuously a first friction agitation step and the first re-friction agitation step, it may be temporarily disengage the large rotating tool G in the folded position O _M1. Further, after the first friction stirring step is finished, the large rotary tool G is once detached, and the first refriction stirring step is performed from the start position S _M1 of the second tab member 3 toward the first tab member 2. Good.
Moreover, in this embodiment, although a pair of tab material was used, it is not limited to this. For example, using only one tab material, the start position and the end position may be set for the tab material, and the folding position may be set on the abutting portion J1 to perform friction stirring.
In the present embodiment, the large rotary tool G is pushed in a predetermined amount at the turn-back position O _M1 , but it may be continuously pushed down during the first re-friction stirring step.

(4) Second Temporary Joining Process In the second provisional joining process, although not specifically illustrated, the small joint tool J2, J1, J3 is provisionally applied from the back surface B of the metal member 1 to be joined using the small rotary tool F. Join. In the second temporary joining step, when the first main joining step is finished, the front and back of the metal member 1 to be joined are reversed and fixed to the friction stirrer. Since the second temporary bonding step is substantially the same as the first temporary bonding step except that the second temporary bonding step is temporary bonding to the back surface B, detailed description thereof is omitted. Note that the second temporary joining step may be omitted.

(5) Second Main Joining Step In the second main joining step, the large rotating tool G is continuously reciprocated from the back surface B of the metal member 1 to be joined along the abutting portion J1 to perform frictional stirring. That is, in the second main joining step, as shown in FIGS. 6A to 6C, the folding position O set on the second tab member 3 from the start position _SM2 set on the first tab member 2. a second friction stir step of performing friction stir until _M2, a pushing step of pushing the large rotating tool G in the folded position O _M2, friction stir from the folded position O _M2 to the end position E _M2 set in the first tab member 2 A second re-friction stirring step to be performed is included.

In a second friction agitation step, as shown in (a) of FIG. 6, the butting portion J1 from the start position S _M2 set in the first tab member 2, until the return position O _M2 set in the second tab member 3 The friction stir is performed continuously along That is, by right rotating the large rotating tool G, after having pushed a predetermined amount shoulder G1, relatively moving the large rotating tool G toward the one end side of the butting portion J1 at the start position S _M2. Push-in amount of large rotating tool G (Distance from the back B to the lower end of the shoulder portion G1) is set to Q _1.

When the large-sized rotating tool G reaches one end of the abutting portion J1, it is allowed to enter the abutting portion J1 across the abutting portion J2. When large rotating tool G reaches the other end of the butting portion J1, it is positioned to the folded position O _M2 across the butting portion J3. That is, the end position of the second friction stir process becomes folded position O _M2. By the second friction stirring step, a third plasticized region W3 is formed on the back surface B of the abutting portion J1. Surface W3 _A third plasticized region W3 is located downward by Q ₁ than the rear surface B of the bonding metal member 1.

Pushing step, as shown in (b) of FIG. 6, when the large rotating tool G reaches the folded position O _M2, it pushed a predetermined amount toward the large rotating tool G downward. And it transfers to a 1st re-friction stirring process, keeping the pushing amount.
Push-in amount of large rotating tools G in pushing step, in this embodiment, Q ₂ is pushed from the surface W3 _A third plasticized region W3. In the present embodiment, the pushing amount is set to Q ₁ > Q ₂ . Pushing amount is in this embodiment were set as described above, may be appropriately set in accordance with such a thickness and composition to be joined metal member 1, at least, than the surface W3 _A third plasticized region W3 What is necessary is just to set so that the lower end of the shoulder part G1 may be located below.

In the second re-friction stirring step, as shown in FIG. 6C, friction stirring is continuously performed from the turn-back position O _M2 to the end position E _M2 set on the first tab material 2. That is, the large rotary tool G is relatively moved toward the end position E _M2 while maintaining the pushing amount at the turn-back position O _M2 . After traversing butting portion J1 one end formed butting portion J3 and the other end to the formed a butting portion J2, respectively, disengaging the large rotating tool G at the end position E _M2. By the second refriction stirring step, a fourth plasticized region W4 is formed in the abutting portion J1. The deepest portion of the fourth plasticization region W4 is formed at a position deeper than the deepest portion of the third plasticization region W3. Further, the surface W4 _A of the fourth plasticization region W4 is positioned lower than the surface A of the metal member 1 to be joined by Q ₁ + Q ₂ .

  According to the second main joining step, it is possible to obtain substantially the same effect as that of the first main joining step, and the second plasticizing region W2 and the third plasticizing region W3 are overlapped by the second main joining step. Therefore, the airtightness and watertightness of the metal member 1 to be bonded can be improved.

Incidentally, the pushing amount of large rotating tool G at the folded position O _M2 may be appropriately set according to the thickness and materials to be joined metal member 1. When the friction stir is performed from both sides of the front surface A and the back surface B of the bonded metal member 1 as in the present embodiment, as shown in FIG. 6C, the second plasticization region W2 and the third plasticity are performed. It is preferable to set so that the plasticizing region W3 or the fourth plasticizing region W4 overlaps. By setting in this way, the friction stir can be performed over the entire length in the thickness direction of the metal member 1 to be bonded, so that the airtightness and water tightness of the metal member 1 to be bonded can be improved.

According to the joining method according to the present embodiment described above, when the first refriction stirring step (second refriction stirring step) is performed, the large rotation equivalent to the first friction stirring step (second friction stirring step) is performed. Since the tool G is used, it is possible to omit work such as replacement of the large rotary tool G.
Further, the large rotary tool G is pushed in from the surface of the plasticized region formed in the first friction stirring step (second friction stirring step) to press the metal member 1 to be joined in the first refriction stirring step (second Since the re-friction stirring step) is performed, even if a cavity defect or the like is formed in the first friction stirring step (second friction stirring step), the repair can be reliably performed.

In addition, by performing frictional stirring using a pair of tab members, the start position, turn-back position, and end position of the rotating tool when performing frictional stirring can be easily set.
Moreover, according to this embodiment, since each tab material and the abutting part J2 and the abutting part J3 of the to-be-joined metal member 1 are each traversed twice, when it crosses for the first time, inside the to-be-joined metal member 1 Even if an oxide film is involved, the oxide film is frictionally agitated when traversed for the second time, so that the airtightness and watertightness of the bonded metal member 1 can be improved.

  As mentioned above, although 1st embodiment of this invention was described, this invention is not limited to 1st embodiment, In the range which does not deviate from the meaning of invention, it can change suitably. In addition, about description of other following embodiments, the description which overlaps with 1st embodiment is abbreviate | omitted.

[Second Embodiment]
The second embodiment according to the present invention is different from the first embodiment in that friction stirring is performed only from the front surface A side of the metal member 1 ′ to be bonded, and the backing member 10 is disposed on the back surface of the metal member 1 ′. Is different.

The joining method according to the second embodiment includes (1) a butting process and (2) a first main joining process.
In the abutting step, the first tab member 2 and the second tab member 3 are disposed at both ends of the metal member 1 ′ to be bonded, and the backing member 10 is disposed on the back surface of the metal member 1 ′ to be bonded. In the present embodiment, the backing member 10 is a plate-like member disposed over the entire length in the longitudinal direction of the abutting portion J1, and has a composition that is substantially the same as the metal member 1 ′ to be joined.

In the first main joining step, as shown in FIG. 7A, the friction stir is performed from the start position S _M11 set for the second tab member 3 to the folding position O _M11 set for the first tab member 2. a first friction stir process, the first re-friction stir for performing a pushing step of pushing the large rotating tool G in the folded position O _M11, friction stir from the folded position O _M11 to the end position E _M11 set in the second tab member 3 It includes a process.

In the first friction agitation step, pushing a large rotating tool G to the starting position S _M11, the friction stir performed in a state of being overlapped and Urato member 10 and the first plasticized region W1 '. Push-in amount of the first friction stir process, in the present embodiment is set to Q _1.
When the large-sized rotary tool G reaches the turn-back position O _M11 , a pressing process of pushing down the large-sized rotary tool G downward is performed. Pushing amount is set to Q ₂ from the 'surface W1 _A' of the first plasticized region W1. Then, while keeping the pushing amount Q ₂ in the pushing step, the process proceeds to the first re-friction agitation step by relatively moving the large rotating tool G toward the end position E _M11.

  As described above, the backing member 10 may be disposed on the back surface of the metal member 1 'to be bonded, and the first friction stirring step, the pushing step, and the first refriction stirring step may be performed only from the front surface A side. In addition, by overlapping the backing member 10 and the first plasticizing region W1 ′ formed in the first friction stirring step, friction stirring can be performed over the entire length of the abutting portion J1, and the metal member 1 to be joined 'Can improve airtightness and watertightness. In addition, what is necessary is just to cut out the backing member 10 after performing a 1st re-friction stirring process.

[Third embodiment]
Moreover, in this embodiment, although the plate-shaped to-be-joined metal member 1 was demonstrated to the example as a metal member, there is no restriction | limiting in particular in the shape and dimension. The joining method according to the third embodiment is different from the first embodiment in that the metal member has a hollow portion. First, the pair of hollow members 41 and 51 will be described in detail.

  As shown to (a) of FIG. 8, in the joining method which concerns on 3rd embodiment, friction stir welding is performed to the butt | matching part J1 of the hollow member 41 and the hollow member 51 which consist of extruded shapes made from an aluminum alloy. The hollow members 41 and 51 are formed by long rectangular parallelepiped frame bodies 46 and 56. In the frame bodies 46 and 56, hollow portions S1 and S2 separated by the plate bodies 45 and 55 are formed.

  As shown in FIGS. 8A and 8B, grooves 42a and 52a are formed on the surfaces 42 and 52 of the frame bodies 46 and 56 of the hollow members 41 and 51, respectively. In addition, strip-shaped surfaces 42b and 52b are formed at positions opposite to the surface 42 across the grooves 42a and 52a. The surfaces 42 and 52 are formed at higher positions than the surfaces 42b and 52b. The hollow member 41 has an extruded shape with the same cross section, but these are abutted to be symmetrical with each other about the abutting portion J1. In addition, grooves and the like are formed in the same manner on the surface (not shown) located on the back side of the front surfaces 42 and 52, but illustration and description thereof are omitted.

  On the other hand, the surfaces 43a and 53a and the surfaces 43b and 53b are formed on the portions where the abutting portions J1 and J1b are formed with the recesses 43c and 53c interposed therebetween. The face 43a and the face 53a are abutted to form an abutting portion J1. Further, the surface 43b and the surface 53b are abutted to form an abutting portion J1b. And the clearance gap S3 is formed of the recessed part 43c and the recessed part 53c so that the abutting part J1 and J1b may be separated. In addition, each length of the surface 43a, 53a and the surface 43b, 53b in the height direction is formed slightly longer than the depth of the plastic fluidized metal formed by the stirring pin G2 (see FIG. 2).

  Therefore, the unevenness of the recesses 43c and 53c is absorbed by the gap S3, and the abutting portions J1 and J1b corresponding to the depth at which frictional stirring is performed are plastically fluidized and integrated as a plasticized region after frictional stirring. Therefore, the unevenness of the abutting portions J1 and J1b is also absorbed after friction stirring. As a result, the surface 43a and the surface 53a are in close contact with each other, and the surface 43b and the surface 53b are in close contact with each other, so that a high-quality joined body between the hollow members 41 and 51 can be formed.

Hereinafter, the bonding method according to the third embodiment will be described in detail. The joining method according to the third embodiment includes (1) a butting process and (2) a first main joining process.
In the butting process, the side surfaces of the hollow members 41 and 51 are butted together and fixed with a jig. That is, as shown in FIG. 8C, the hollow members 41 and 51 are placed on a pedestal (not shown), and the upper surfaces 42 and 52 are placed by jigs 91 and 92 disposed beside the side surfaces 47 and 57. The side surfaces 47 and 57 are pressed and fixed by the jig 93 and the same jig (not shown) located on the opposite side of the jig 93. Further, a jig 94 for supporting the tab member 2A from below is installed on the opening end side of the hollow members 41 and 51.

  And as shown to (a) of FIG. 9, the tab material 2A (equivalent to the 1st tab material 2) fixed to the surface 94a formed in the upper side of the jig | tool 94, and the end surface of the hollow members 41 and 51, Are joined together to form a joint surface (corresponding to the abutting portion J2). Further, on the opposite end side (not shown) of the hollow members 41 and 51, a tab material (not shown) corresponding to the second tab material 3 is similarly arranged by a jig (not shown).

In the first main joining step, the first friction stirring step, the pushing step, and the first re-friction stirring step are performed in the same manner as in the first embodiment. That is, as shown in FIG. 9A, in the first friction stirring step, the large rotary tool G is pressed to a start position (not shown) and friction stirring is performed along the abutting portion J1.
In the pushing step, the large-sized rotating tool G is pushed by a predetermined amount at the folding position set on the tab material 2A. And as shown in FIG.9 (b), a 1st refriction stirring process is performed along the abutting part J1 (1st plasticization area | region W1 ''), keeping the pushing amount in a pushing process. Since the first friction stirring step, the pushing step, and the first refriction stirring step are substantially the same as those in the first embodiment, detailed description thereof is omitted.

  Further, after joining the abutting portion J1, the abutting portion J1b on the back side is similarly agitated by friction stir to join the hollow member 41 and the hollow member 51 on the front and back surfaces. Thereby, the hollow member 41 and the hollow member 51 are reliably joined in the abutting part J1 and the abutting part J1b.

  As shown in FIGS. 8A and 8B, the surfaces 42b and 52b forming the abutting portion J1 are higher than the bottom surfaces of the grooves 42a and 52a and are formed in a convex shape. It has a height and thickness capable of expressing the required strength. The surfaces 42b and 52b remain as convex portions even after frictional stirring. Further, the width dimensions of the surfaces 42b and 52b are larger than the shoulder diameter of the large rotary tool G (the outer diameter of the shoulder portion G1). The abutting part J1b is also formed with the same configuration.

  On the other hand, since the surfaces 42b and 52b are formed lower than the surfaces 42 and 52, even if unevenness occurs on the surfaces 42b and 52b due to frictional stirring, the surfaces 42b and 52b do not protrude beyond the surfaces 42 and 52. Therefore, the uneven surfaces of the plasticized region after friction stirring do not overlap each other. Therefore, as shown in FIG. 10, when the joined body 60A and the joined body 60B are further subjected to friction stir welding, the mating surfaces to be brought into close contact with each other can be securely brought into contact with each other, so that the joining is not caused. Will be able to. Although not shown here, the joined bodies 60A and 60B may perform frictional stirring on the left and right side surfaces. Also in this case, it is preferable that a structure corresponding to the groove 42a or the like is formed on the side surface.

It is a figure for demonstrating arrangement | positioning of the metal member which concerns on 1st embodiment, a 1st tab material, and a 2nd tab material, Comprising: (a) is a perspective view, (b) is a top view, (c) is (b) ) Is a cross-sectional view taken along the line II of FIG. (A) is the side view which showed the small rotation tool, (b) is the side view which showed the large rotation tool. It is the top view which showed the temporary joining process which concerns on 1st embodiment. It is the figure which showed the 1st main joining process based on 1st embodiment, Comprising: (a) is a 1st friction stirring process, (b) is the figure which showed the 1st refriction stirring process. It is the III-III sectional view taken on the line of (a) of FIG. 4, (a) shows a 1st friction stirring process, (b) shows an indentation process, (c) shows a 1st refriction stirring process. (A) is a 2nd friction stirring process, (b) is an indentation process, (c) shows a 2nd refriction stirring process. It is the figure which showed the 1st main joining process which concerns on 2nd embodiment, Comprising: (a) is a 1st friction stirring process, (b) is an indentation process, (c) is a 1st refriction stirring process. Show. It is the figure which showed the joining method which concerns on 3rd embodiment, Comprising: (a) is a perspective view which shows a hollow member, (b) is a principal part enlarged view which shows the mode of the end surface of a hollow member, (c) is a tab material It is a perspective view which shows a mode just before arrange | positioning. It is the perspective view which showed the joining method which concerns on 3rd embodiment, Comprising: (a) shows a 1st friction stirring process, (b) shows a 1st refriction stirring process. It is a perspective view which shows the mode of a hollow member when two joined bodies of a hollow member are further friction stir welded. It is sectional drawing which showed the conventional joining method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal member to be joined 1a Metal member 1b Metal member 2 First tab material 3 Second tab material 41, 51 Hollow member 42, 52 Surface 42a, 52a Groove 42b, 52b Surface 43a, 43b Surface 53a, 53b Surface 43c, 53c Groove 60A, 60B Joint J1 Abutting part F Small rotating tool G Large rotating tool P1 Pilot hole W Plasticization region _SM Start position O _M Folding position E _M End position

Claims (9)

A joining method in which friction agitation is performed on a butted portion formed by abutting a pair of metal members,
A first friction stirring step of performing friction stirring from one surface side of the metal member with respect to the abutting portion;
Using the same rotary tool as the rotary tool used in the first friction stirring step, the first friction stirring is performed from one surface side of the metal member with respect to the plasticized region formed in the first friction stirring step. A first re-friction stirring step of performing friction stirring again at a position deeper than the step. A joining method in which friction agitation is performed on a butted portion formed by abutting a pair of metal members,
A first friction stirring step of performing friction stirring from one surface side of the metal member with respect to the abutting portion;
Using the same rotary tool as the rotary tool used in the first friction stirring step, the first friction stirring is performed from one surface side of the metal member with respect to the plasticized region formed in the first friction stirring step. A first re-friction stirring step in which friction stirring is performed again at a position deeper than the step;
A second friction stirring step of performing friction stirring from the other surface side of the metal member with respect to the abutting portion;
Using the same rotating tool as the rotating tool used in the second friction stirring step, the second friction stirring from the other surface side of the metal member with respect to the plasticized region formed in the second friction stirring step. Including a second re-friction stirring step in which friction stirring is performed again at a position deeper than the step,
A joining method, wherein plasticized regions formed by the first refriction stirring step and the second refriction stirring step overlap each other.   The joining method according to claim 1 or 2, wherein the first friction stirring step and the first re-friction stirring step are continuously performed.   The joining method according to claim 2, wherein the second friction stirring step and the second refriction stirring step are continuously performed.   A pair of tab members are disposed at both ends of the abutting portion, the friction stirring start position and end position are set in one tab member, and the friction stirring return position is set in the other tab member. The joining method according to claim 3 or 4. Before performing the first friction stirring step,
The temporary joining process of performing temporary joining with respect to the said abutting part using a rotary tool smaller than the rotational tool used at said 1st friction stirring process is included, The Claim 1 thru | or 5 characterized by the above-mentioned. The joining method according to one item. Before performing the second friction stirring step,
The temporary joining process of performing temporary joining with respect to the said abutting part using a rotary tool smaller than the rotational tool used at said 2nd friction stirring process is included. The joining method according to one item. In the joining method according to any one of claims 1 to 7,
A joining method, wherein the metal member is a hollow member. The joining method according to claim 8,
A joining method, wherein a concave portion is formed on an abutting surface of the hollow member, and a gap by the concave portion is formed at an abutting portion between the hollow members.

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