JP2016078087A - Joining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining method that allows a cylindrical member and a lid member to be securely joined to each other.SOLUTION: The joining method for joining a cylindrical member 2 and a lid member 3 to cover an opening of the cylindrical member 2 includes: a butting step of butting the cylindrical member 2 and the lid member 3 against each other so that an outer peripheral surface 2c of the cylindrical member 2 and an outer peripheral surface 3c of the lid member 3 are flush with each other, and forming a butting portion J1; an outside friction stir step of friction stirring the butting portion J1 from the outside of the cylindrical member 2; a welding step of performing weld overlay on the butting portion J1 from the inside of the cylindrical member 2; and an inside friction stir step of, after the outside friction stir step, friction stirring the butting portion J1 from the inside of the cylindrical member 2, with only a stirring pin F2 being in contact with the cylindrical member 2, the lid member 3 and weld metal R1 formed by the weld overlaying.SELECTED DRAWING: Figure 6

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 protruding a stirring pin (probe) on the lower end surface of a cylindrical shoulder portion.

  For example, Patent Document 1 discloses a technique in which a metallic cylindrical member and a lid member that covers an opening of the cylindrical member are joined by friction stirring. In this technique, inner corners constituted by a cylindrical member and a lid member are joined by welding.

International Publication No. 2009 / 081731A1 Pamphlet

  Joining the inner corner composed of the cylindrical member and the lid member becomes difficult because the work space is limited. In particular, when performing friction stir welding at the inner corner, there is a problem that the stirrer pin cannot be inserted to a deep position because the shoulder portion contacts the cylindrical member and the lid member with a conventional rotary tool. In addition, since the plastic fluidized metal cannot be pressed by the shoulder portion, the metal may overflow to the outside, resulting in insufficient metal and poor bonding.

  From such a viewpoint, an object of the present invention is to provide a joining method capable of reliably joining a cylindrical member and a lid member.

In order to solve such a problem, the present invention is a joining method for joining a metal cylindrical member and a metal lid member covering an opening of the cylindrical member, the outer periphery of the cylindrical member A butting step in which the tubular member and the lid member are butted so that the surface and the outer peripheral surface of the lid member are flush with each other; and from the outside of the tubular member with respect to the butting portion After the outer friction stirring step of performing friction stirring, the welding step of performing overlay welding from the inside of the cylindrical member to the butt portion, and after the outer friction stirring step, only the stirring pin is attached to the cylindrical member and the lid. An inner friction agitation step in which friction agitation is performed from the inside of the cylindrical member to the butt portion in a state where the member and the weld metal formed by overlay welding are brought into contact with each other.
Further, the present invention is a joining method for joining a metal cylindrical member and a metal lid member covering the opening of the cylindrical member, the outer circumferential surface of the cylindrical member and the outer circumference of the lid member A butting step in which the tubular member and the lid member are butted so as to be flush with each other, and an abutting portion is formed from the outside of the tubular member with respect to the butting portion. After the step, the auxiliary member arranging step of arranging an auxiliary member at the inner corner constituted by the cylindrical member and the lid member, and the outer friction stirring step, only the stirring pin is placed on the cylindrical member and the lid member. And an inner friction agitation step in which friction agitation is performed from the inside of the cylindrical member to the abutting portion in a state of being in contact with the auxiliary member.

  According to such a joining method, even if only the stirring pin is inserted into the butt portion and friction stirring is performed from the inside of the cylindrical member, build-up welding is performed on the inner corner or the auxiliary member is disposed. Therefore, the metal shortage can be solved. Thereby, the inner corner of a cylindrical member and a cover member can be joined reliably.

  Moreover, it is preferable to include the temporary joining process of performing temporary joining to the said butt | matching part from the outer side of a cylindrical member before the said outside friction stirring process. According to this joining method, it is possible to prevent the opening of the butt portion during the outer friction stirring step.

Further, the present invention is a joining method for joining a metal cylindrical member and a metal lid member covering the opening of the cylindrical member, the outer peripheral surface of the cylindrical member and the lid member A butting step in which the tubular member and the lid member are butted so as to be flush with the outer peripheral surface, and a butting portion is formed, and welding in which overlay welding is performed on the butting portion from the inside of the tubular member An inner side for frictional stirring from the inner side of the cylindrical member to the butted portion in a state where only the stirring pin is in contact with the cylindrical member, the lid member and the weld metal formed by overlay welding A friction stirring step; and an outer friction stirring step of performing friction stirring from the outside of the cylindrical member to the butted portion after the inner friction stirring step.
Further, the present invention is a joining method for joining a metal cylindrical member and a metal lid member covering the opening of the cylindrical member, the outer peripheral surface of the cylindrical member and the lid member An abutting step in which the cylindrical member and the lid member are abutted to form an abutting portion so that the outer peripheral surface is flush with the outer peripheral surface, and an auxiliary member is provided at an inner corner formed by the cylindrical member and the lid member. Auxiliary member arrangement step to be arranged, and inner friction agitation in which friction agitation is performed from the inside of the cylindrical member to the butting portion in a state where only the agitation pin is in contact with the cylindrical member, the lid member, and the auxiliary member And an outer friction stirring step of performing friction stirring on the butted portion from the outside of the cylindrical member after the inner friction stirring step.

  According to such a joining method, even if only the stirring pin is inserted into the butt portion and friction stirring is performed from the inside of the cylindrical member, build-up welding is performed or the auxiliary member is disposed. The metal shortage can be solved. Thereby, the inner corner of a cylindrical member and a cover member can be joined reliably.

  Moreover, it is preferable to include the temporary joining process of performing temporary joining from the outer side of the said cylindrical member with respect to the said butt | matching part before the said welding process or the said auxiliary member arrangement | positioning process. According to this joining method, a welding process or an auxiliary member arrangement process can be performed stably.

  According to the joining method according to the present invention, the tubular member and the lid member can be reliably joined.

(A) is the side view which showed the rotation tool for this joining of this embodiment, (b) is the schematic cross section which showed the joining form of the rotation tool for this joining. (A) is the side view which showed the rotary tool for temporary joining of this embodiment, (b) is the schematic cross section which showed the joining form of the rotary tool for temporary joining. (A) is a disassembled perspective view which shows the structure which concerns on 1st embodiment, (b) is a perspective view which shows the temporary joining process which concerns on 1st embodiment. (A) is a perspective view which shows the outer side friction stirring process which concerns on 1st embodiment, (b) is sectional drawing which shows the outer side friction stirring process which concerns on 1st embodiment. It is a perspective view which shows the welding process which concerns on 1st embodiment. (A) is a perspective view which shows the inner side friction stirring process which concerns on 1st embodiment, (b) is sectional drawing which shows the inner side friction stirring process which concerns on 1st embodiment. (A) is a disassembled perspective view which shows the structure which concerns on 2nd embodiment, (b) is a perspective view which shows the temporary joining process which concerns on 2nd embodiment. (A) is a perspective view which shows the outer side friction stirring process which concerns on 2nd embodiment, (b) is sectional drawing which shows the outer side friction stirring process which concerns on 2nd embodiment. (A) is a perspective view which shows the auxiliary member arrangement | positioning process which concerns on 2nd embodiment, (b) is sectional drawing which shows the auxiliary member arrangement | positioning process which concerns on 2nd embodiment. (A) is a perspective view which shows the inner side friction stirring process which concerns on 2nd embodiment, (b) is sectional drawing which shows the inner side friction stirring process which concerns on 2nd embodiment. (A) is sectional drawing which shows the welding process which concerns on 3rd embodiment, (b) is sectional drawing which shows the outer side friction stirring process and inner side friction stirring process which concern on 3rd embodiment. (A) is sectional drawing which shows the auxiliary member arrangement | positioning process which concerns on 4th embodiment, (b) is sectional drawing which shows the outer side friction stirring process and inner side friction stirring process which concern on 4th embodiment.

[First embodiment]
The joining method according to the first embodiment of the present invention will be described in detail with reference to the drawings. First, the main joining rotary tool and the temporary joining rotary tool used in the present embodiment will be described.

  As shown to (a) of FIG. 1, this rotation tool F for joining is comprised by the connection part F1 and the stirring pin F2. The main rotating tool F for joining is formed of, for example, tool steel. The connection part F1 is a part connected to the rotating shaft D of the friction stirrer shown in FIG. The connecting portion F1 has a cylindrical shape, and is formed with screw holes B and B to which bolts are fastened.

  The stirring pin F2 hangs down from the connecting portion F1 and is coaxial with the connecting portion F1. The stirring pin F2 is tapered as it is separated from the connecting portion F1. The length of the stirring pin F2 is larger than the plate thickness of the cylindrical member 2 and the lid member 3 which will be described later. A spiral groove F3 is formed on the outer peripheral surface of the stirring pin F2. In the present embodiment, the spiral groove F3 is formed in a counterclockwise direction from the proximal end toward the distal end in order to rotate the main joining rotary tool F to the right. In other words, the spiral groove F3 is formed counterclockwise as viewed from above when the spiral groove F3 is traced from the base end to the tip.

  In addition, when rotating this welding rotation tool F counterclockwise, it is preferable to form the spiral groove F3 in the clockwise direction from the proximal end toward the distal end. In other words, the spiral groove F3 in this case is formed clockwise when viewed from above when the spiral groove F3 is traced from the proximal end to the distal end. By setting the spiral groove F3 in this way, the plastic fluidized metal at the time of frictional stirring is guided to the tip side of the stirring pin F2 by the spiral groove F3. Thereby, the quantity of the metal which overflows to the exterior of a structure (The cylindrical member 2 and the lid member 3 mentioned later) can be decreased.

  As shown in FIG. 1B, when the friction stir welding is performed using the main rotating tool F for welding, only the rotated stirring pin F2 is inserted into the structure, and the structure and the connecting portion F1 are separated from each other. Move while separating. In other words, the friction stir welding is performed with the base end portion of the stirring pin F2 exposed. A plasticized region W1 (or a plasticized region W2) is formed in the movement trajectory of the main rotating tool F for bonding by hardening the friction-stirred metal.

  As shown in FIG. 2A, the temporary bonding rotary tool G includes a shoulder portion G1 and a stirring pin G2. The temporary joining rotary tool G is made of, for example, tool steel. As shown in FIG. 2B, the shoulder portion G1 is a portion that is connected to the rotating shaft D of the friction stirrer and is a portion that holds the plastic fluidized metal. The shoulder portion G1 has a cylindrical shape. The lower end surface of the shoulder portion G1 has a concave shape in order to prevent the fluidized metal from flowing out.

  The stirring pin G2 is suspended from the shoulder portion G1, and is coaxial with the shoulder portion G1. The stirring pin G2 is tapered as it is separated from the shoulder portion G1. A spiral groove G3 is formed on the outer peripheral surface of the stirring pin G2.

  As shown in FIG. 2B, when friction stir welding is performed using the temporary welding rotary tool G, the rotated stirring pin G2 and the lower end surface of the shoulder portion G1 are inserted into the metal member to be joined. Move. A plasticized region W is formed in the movement locus of the temporary bonding rotary tool G by hardening the friction-stirred metal.

  Next, the joining method of this embodiment is demonstrated. In the joining method according to this embodiment, as shown in FIG. 3A, a case where the tubular body 2 and the lid member 3 are joined by friction stirring to form the structure 1 is illustrated.

  The cylindrical member 2 is a metal member and has a rectangular frame shape in cross section. The material of the cylindrical member 2 may be appropriately selected from metal materials capable of friction stirring such as aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, magnesium, and magnesium alloy. The cylindrical member 2 is formed with a constant plate thickness.

  The lid member 3 is a metal member and has a rectangular plate shape. The lid member 3 is a member that covers the opening of the cylindrical member 2. The material of the lid member 3 may be appropriately selected from metal materials that can be frictionally stirred, but in this embodiment, a material equivalent to that of the cylindrical member 2 is used.

  In the joining method according to the present embodiment, a butt process, a temporary joining process, an outer friction stirring process, a welding process, and an inner friction stirring process are performed.

  The butting process is a process in which the opening of the tubular member 2 is covered with the lid member 3 and the tubular member 2 and the lid member 3 are butted together. More specifically, in the butting step, the end surface 2a of the cylindrical member 2 and the back surface 3b of the lid member 3 are butted together, and the outer circumferential surface 2c of the cylindrical member 2 and the outer circumferential surface 3c of the lid member 3 are flush with each other. Match so that. A butt portion J1 (see FIG. 3B) is formed by the butt process.

  The temporary joining process is a process of temporarily joining the butt joint J1. As shown in FIG. 3B, in the temporary bonding step, the butting portion J1 is temporarily bonded using the temporary bonding rotary tool G. A plasticized region W is formed on the movement trajectory of the temporary bonding rotary tool G. In the temporary joining step, the shoulder G1 of the temporary joining rotary tool G is pushed into the tubular member 2 and the lid member 3 by about several millimeters, and frictional stirring is performed. The temporary joining step may be performed continuously along the abutting portion J1, or may be performed intermittently as shown in FIG.

  The outer friction agitation step is a step in which the butt J1 is frictionally agitated and joined from the outside of the cylindrical member 2 in earnest. In the outer friction agitation step, as shown in FIG. 4A, the main-joining rotary tool F rotated to an arbitrary start position s1 on the butt portion J1 is inserted. The insertion depth of the main joining rotary tool F may be set as appropriate. In this embodiment, the insertion depth is about half the plate thickness of the cylindrical member 2. The rotation center axis of the main rotating tool F for joining is inserted so as to be perpendicular to the joining surface (the outer circumferential surface 2c of the cylindrical member 2 and the outer circumferential surface 3c of the lid member 3. And, in the outer friction stirring step, A relative movement is made by tracing the butting portion J1 and a plasticizing region W1 is formed in the movement locus of the main rotating tool F. In the outer friction stirring step, only the stirring pin F2 is moved to the cylindrical member 2 and the lid member. 3, and friction stir is performed with the proximal end side of the stirring pin F2 exposed.

  After the abutting portion J1 is made to make one turn with the main welding rotary tool F, the start position s1 is passed through to overlap the start and end of the plasticizing region W1, and then the main welding rotary tool F is attached to the cylindrical member 2 and The lid member 3 is detached. In addition, when the extraction trace of the stirring pin F2 remains after the main rotating tool F is detached, a repair process may be performed in which the extraction trace is repaired by overlay welding. Thereby, a joining surface can be finished finely.

  Further, the main welding rotary tool F may be detached while gradually decreasing the insertion depth of the main welding rotary tool F. Thereby, the extraction trace of the stirring pin F2 can be eliminated or the extraction trace can be reduced.

  In the outer friction agitation step and the inner friction agitation step described later, for example, the main rotating tool F can be attached to the tip of a robot arm equipped with a rotation drive means such as a spindle unit to perform friction agitation. Thereby, the angle of the rotation center axis | shaft of the rotation tool F for this joining can be changed easily.

  The welding process is a process of overlay welding such as TIG welding or MIG welding from the inside of the cylindrical member 2 to the butt portion J1. In the welding process, as shown in FIG. 5, overlay welding is performed from the inside of the tubular member 2 over the entire length of the butt portion J1. As a result, the weld metal R <b> 1 is formed at the inner corner constituted by the tubular member 2 and the lid member 3. The size of the weld metal R1 is preferably set to such an extent that when the inner frictional stirring step described later is performed, the joint does not run out of metal and burrs do not remain excessively.

  The inner friction agitation step is a step in which friction agitation joining is performed in earnest from the inner side of the tubular member 2 to the weld metal R1 and the butt portion J1. In the inner friction agitation process, as shown in FIG. 6A, the rotated main welding rotation tool F is moved to an arbitrary starting position s2 of the weld metal R1 (butting portion J1) until reaching the butting portion J1. insert. In the inner friction agitation step, as shown in FIG. 6B, the rotation center axis of the main welding rotary tool F and the back surface 3b of the lid member 3 are inserted at an angle of 45 °. Then, friction stir is performed by tracing the weld metal R1 while maintaining the angle. In the inner friction agitation step, only the agitation pin F2 is brought into contact with the cylindrical member 2, the lid member 3 and the weld metal R1, and friction agitation is performed with the proximal end side of the agitation pin F2 exposed. A plasticized region W2 is formed on the movement trajectory of the main rotating tool for welding F.

  The insertion depth of the main joining rotary tool F may be set as appropriate. However, as in the present embodiment, the plasticizing region W2 and the plasticizing region W1 formed in the outer friction stirring step overlap each other. It is preferable. By doing in this way, the whole depth direction of the butt | matching part J1 can be friction stir welded, and joining strength, watertightness, and airtightness can be improved.

  After the abutting portion J1 is made to make one turn with the main welding rotary tool F, the start position s2 is passed through to overlap the start and end of the plasticizing region W2, and then the main welding rotary tool F is attached to the cylindrical member 2 and The lid member 3 is detached. When detaching the main welding rotary tool F, a repairing process may be performed in the same manner as the outer friction stirring process, or the main rotating tool F is removed by gradually decreasing the insertion depth. You may let them.

  The insertion angle of the main welding rotary tool F may be changed so that the angle formed between the rotation center axis of the main welding rotary tool F and the back surface 3b of the lid member 3 is smaller than 45 °. By doing in this way, plastic fluidization can be performed to a deeper position of the butt portion J1. When the inner friction agitation process is completed, burrs and the like generated in the outer friction agitation process and the inner friction agitation process are removed. Thereby, the surface of the structure 1 can be finished finely.

  According to the joining method according to the present embodiment described above, even if friction stirring is performed with only the stirring pin F2 in contact with the cylindrical member 2 and the lid member 3 from the inside of the cylindrical member 2, overlay welding is performed. Since the weld metal R1 is applied, the metal shortage can be solved. Thereby, the inner corner of the cylindrical member 2 and the lid member 3 can be reliably joined. Moreover, since an outer friction stirring process is performed first, a welding process can be performed stably.

  Moreover, by performing a temporary joining process, the opening of the butt | matching part J1 can be prevented in the case of an outside friction stirring process. Moreover, according to this embodiment, since only the stirring pin F2 is inserted into the cylindrical member 2, the lid member 3, and the weld metal R1, the load applied to the friction stirrer is reduced as compared with the case where the shoulder portion of the rotary tool is pushed. In addition, the operability of the rotary tool F for bonding can be improved. Moreover, since the load concerning a friction stirrer can be reduced, the deep position of the butt | matching part J1 can be joined in the state which does not apply a big load to a friction stirrer.

  The first embodiment is not limited to the above-described form. For example, when performing the outer friction stirring step shown in FIG. 4, the tab material is disposed, and the tab material is temporarily joined to the cylindrical member 2 and the lid member 3, and the main rotation tool F is joined to the tab material. A start position and an end position may be set. By using the tab material, the start position and the end position of the main welding rotary tool F can be easily set. Moreover, it is not necessary to perform the repair process of the drawing trace of this rotary tool F for joining.

Moreover, in this embodiment, after the outer friction stirring step, a welding step of performing overlay welding from the inside of the tubular member 2 to the butt joint J1 was performed.For example, before the outer friction stirring step, You may perform the welding process which performs overlay welding from the inner side of the cylindrical member 2 with respect to the butt | matching part J1.
Further, in the outer friction agitation step of the present embodiment, the main rotating tool F is used. However, a rotating tool including a shoulder portion and a stirring pin is used, and the shoulder portion is used as the cylindrical member 2 and the lid member 3. Friction stir welding may be performed by pushing about several millimeters.

  Moreover, although the cylindrical member 2 was made into the rectangular cylinder shape in this embodiment, it is good also as a cylindrical shape, an elliptical cylinder shape, or another polygonal cylinder shape. Moreover, you may abbreviate | omit a temporary joining process. Further, at least one of the cylindrical member 2 and the lid member 3 may be provided with a step so as to face each other.

[Second Embodiment]
Next, the joining method according to the second embodiment of the present invention will be described. The joining method according to the second embodiment is different from the first embodiment mainly in that the cylindrical member 2A and the lid member 3A are cylindrical and the auxiliary member 4 is used.

  In the joining method according to the present embodiment, as shown in FIG. 7A, the cylindrical member 2A and the lid member 3A are joined by friction stirring to form the structure 1A. The cylindrical member 2A has a cylindrical shape. The lid member 3A has a disk shape. The outer diameter of the lid member 3A is equal to the outer diameter of the cylindrical member 2A.

  In the joining method according to the present embodiment, a butt process, a temporary joining process, an outer friction stirring process, an auxiliary member arranging process, and an inner friction stirring process are performed.

  The butting process is a process of covering the opening of the cylindrical member 2A with the lid member 3A and butting the cylindrical member 2A and the lid member 3A. More specifically, in the butting step, the end surface 2a of the cylindrical member 2A and the back surface 3b of the lid member 3A are butted together, and the outer peripheral surface 2c of the cylindrical member 2A and the outer peripheral surface 3c of the lid member 3A are flush with each other. Match so that. A butt J1 (see FIG. 7B) is formed by the butt process.

  The temporary joining process is a process of temporarily joining the butt joint J1. As shown in FIG. 7B, in the temporary bonding step, the butting portion J1 is temporarily bonded using the temporary bonding rotary tool G. A plasticized region W is formed on the movement trajectory of the temporary bonding rotary tool G. In the temporary joining step, the shoulder G1 of the temporary joining rotary tool G is pushed into the tubular member 2 and the lid member 3 by about several millimeters, and frictional stirring is performed. The temporary joining process may be performed continuously along the abutting portion J1, or may be performed intermittently as shown in FIG.

  The outer friction agitation step is a step in which the abutting portion J1 is frictionally agitated and joined from the outside of the cylindrical member 2A. In the outer friction agitation step, as shown in FIG. 8A, the main welding rotating tool F rotated to an arbitrary start position s1 of the butting portion J1 is inserted. The rotation center axis of the main rotating tool for welding F is inserted so as to overlap the normal line of the start position s1. The insertion depth of the main joining rotary tool F may be set as appropriate. In this embodiment, the insertion depth is about half of the thickness of the cylindrical member 2A. In the outer friction agitation step, the main welding rotary tool F is relatively moved so as to trace the butting portion J1. In the present embodiment, the position of the main welding rotary tool F is fixed, and the cylindrical member 2A and the lid member 3A are rotated about the central axis. A plasticized region W1 is formed on the movement trajectory of the main rotating tool F for welding. In the outer friction stirring step, only the stirring pin F2 is brought into contact with the cylindrical member 2A and the lid member 3A, and friction stirring is performed with the base end side of the stirring pin F2 exposed.

  After the abutting portion J1 is made to make one turn with the main welding rotary tool F, the start position s1 is passed through to overlap the start and end of the plasticizing region W1, and then the main welding rotary tool F is attached to the cylindrical member 2 and The lid member 3 is detached. When detaching the main welding rotary tool F, a repair process may be performed in the same manner as in the first embodiment, or the main welding rotary tool F is removed so that the insertion depth is gradually reduced. You may let them.

  In the outer friction agitation step and the inner friction agitation step described later, for example, the main rotating tool F can be attached to the tip of a robot arm equipped with a rotation drive means such as a spindle unit to perform friction agitation. Thereby, the angle of the rotation center axis | shaft of the rotation tool F for this joining can be changed easily.

  The auxiliary member arranging step is a step of arranging the auxiliary member 4 at the inner corners of the cylindrical member 2A and the lid member 3A as shown in FIGS. The auxiliary member 4 is a ring-shaped member having a triangular shape in cross section. The outer diameter of the auxiliary member 4 is equivalent to the inner diameter of the cylindrical member 2A. The material of the auxiliary member 4 is preferably the same material as the cylindrical member 2A and the lid member 3A.

  In the auxiliary member arranging step, as shown in FIG. 9B, the auxiliary member 4 is arranged so as to cover the butted portion J1 at the inner corner between the cylindrical member 2A and the lid member 3A. More specifically, the side surface 4a of the auxiliary member 4 is brought into surface contact with the inner peripheral surface 2b of the cylindrical member 2A, and the bottom surface 4b of the auxiliary member 4 is brought into surface contact with the back surface 3b of the lid member 3. It is preferable to set the size of the auxiliary member 4 to such an extent that when the inner friction stirring step described later is performed, the joining portion does not have insufficient metal and burrs do not remain excessively.

  The inner friction agitation step is a step in which friction agitation welding is performed in earnest from the inner side of the cylindrical member 2A to the auxiliary member 4 and the butting portion J1. In the inner friction agitation step, as shown in FIG. 10 (a), the main rotating tool F rotated to an arbitrary starting position s2 of the inclined surface 4c (butting portion J1) of the auxiliary member 4 is applied to the butting portion J1. Insert until it reaches. In the inner friction agitation step, as shown in FIG. 10B, the inner rotation tool F is inserted so that the angle formed by the rotation center axis of the main rotating tool F and the back surface 3b of the lid member 3A is 45 °. Then, the main rotating tool F is moved relative to the auxiliary member 4 while keeping the angle. In the inner friction stirring step, only the stirring pin F2 is brought into contact with the cylindrical member 2, the lid member 3 and the auxiliary member 4, and the friction stirring is performed with the base end side of the stirring pin F2 exposed. A plasticized region W2 is formed on the movement trajectory of the main rotating tool for welding F.

  The insertion depth of the main joining rotary tool F may be set as appropriate. However, as in the present embodiment, the plasticizing region W2 and the plasticizing region W1 formed in the outer friction stirring step overlap each other. It is preferable. By doing in this way, the whole depth direction of the butt | matching part J1 can be friction stir welded, and joining strength, watertightness, and airtightness can be improved.

  After the abutting portion J1 is made to make one turn with the main welding rotary tool F, the start position s2 is passed through to overlap the start and end of the plasticizing region W2, and then the main welding rotary tool F is attached to the cylindrical member 2 and The lid member 3 is detached. When detaching the main welding rotary tool F, a repair process may be performed as in the first embodiment, or the main rotary tool F for detachment is gradually reduced in depth. You may let them.

  The insertion angle of the main welding rotary tool F may be changed so that the angle formed between the rotation center axis of the main welding rotary tool F and the back surface 3b of the lid member 3 is smaller than 45 °. By doing in this way, plastic fluidization can be performed to a deeper position of the butt portion J1. When the inner friction agitation process is completed, burrs and the like generated in the outer friction agitation process and the inner friction agitation process are removed. Thereby, the surface of 1 A of structures can be finished finely.

  According to the joining method according to the present embodiment described above, even if friction stirring is performed with only the stirring pin F2 in contact with the cylindrical member 2A and the lid member 3A from the inside of the cylindrical member 2A, the auxiliary member 4 is used. The shortage of metal in the inner corner can be resolved because of the arrangement. Thereby, the inner corner of 2 A of cylindrical members and 3 A of lid members can be joined reliably. Moreover, since an outer side friction stirring process is performed previously, an auxiliary member arrangement | positioning process can be performed stably.

Moreover, by performing a temporary joining process, the opening of the butt | matching part J1 can be prevented in the case of an outside friction stirring process. Moreover, according to this embodiment, since only the stirring pin F2 is inserted into the cylindrical member 2, the lid member 3, and the auxiliary member 4, the load applied to the friction stirrer is reduced as compared with the case where the shoulder portion of the rotary tool is pushed. In addition, the operability of the rotary tool F for bonding can be improved. Moreover, since the load concerning a friction stirrer can be reduced, the deep position of the butt | matching part J1 can be joined in the state which does not apply a big load to a friction stirrer.

The second embodiment is not limited to the above-described form. In the outer friction stirring step of the present embodiment, the main welding rotary tool F is used. However, a rotary tool including a shoulder portion and a stirring pin is used, and the shoulder portion is attached to the cylindrical member 2A and the lid member 3A by several millimeters. Friction stir welding may be performed by pushing in to some extent.

Further, in this embodiment, after the outer friction stirring step, the auxiliary member arranging step of arranging the auxiliary member 4 in the inner corner constituted by the cylindrical member 2 and the lid member 3 is performed. You may perform the auxiliary member arrangement | positioning process which arrange | positions the auxiliary member 4 in the inner corner comprised with the cylindrical member 2 and the cover member 3 before the stirring process.
In the present embodiment, the cylindrical member 2A is cylindrical, but may be elliptical or polygonal. Moreover, you may abbreviate | omit a temporary joining process. Further, at least one of the cylindrical member 2A and the lid member 3A may be provided with a step so as to face each other.

[Third embodiment]
Next, the joining method according to the third embodiment of the present invention will be described. The joining method according to the third embodiment is a form that approximates the first embodiment, and the order of steps is mainly different from that of the first embodiment. In the third embodiment, a description will be given focusing on the parts that are different from the first embodiment.

  The joining method according to the third embodiment performs a butting step, a temporary joining step, a welding step, an inner friction stirring step, and an outer friction stirring step in this order.

  Since the butting process and the temporary joining process are the same as those in the first embodiment, the description thereof is omitted. As shown to (a) of FIG. 11, in a welding process, build-up welding is performed from the inner side of the cylindrical member 2 with respect to the butt | matching part J1 in the same way as 1st embodiment. Through the welding process, a weld metal R1 is formed at the inner corner between the tubular member 2 and the lid member 3. In this embodiment, since a welding process is performed after performing a temporary joining process, a welding process can be performed stably.

  In the inner friction agitation step, friction agitation welding is performed from the inner side of the tubular member 2 to the weld metal R1 and the butt joint J1 in the same manner as the inner friction agitation step of the first embodiment. As shown in FIG. 11B, a plasticized region W1 is formed in the butt joint J1 by the inner friction stirring step.

  In the outer friction agitation step, friction agitation welding is performed from the outside of the tubular member 2 to the butted portion J1 in the same manner as the outer friction agitation step of the first embodiment. In the outer friction agitation step, as shown in FIG. 11B, the insertion depth of the rotary tool F for main joining is set such that the plasticized region W2 and the plasticized region W1 formed in the outer friction agitation step are in contact with each other. It is preferable to set the length. Thereby, the whole depth direction of the butt | matching part J1 can be friction-stir-welded, and joining strength, watertightness, and airtightness can be improved.

  According to this embodiment described above, substantially the same effect as that of the first embodiment can be obtained.

[Fourth embodiment]
Next, the joining method according to the fourth embodiment of the present invention will be described. The joining method according to the fourth embodiment is a form that approximates the second embodiment, and the order of steps is mainly different from that of the second embodiment. In the fourth embodiment, a description will be given centering on portions that are different from the second embodiment.

  In the joining method according to the fourth embodiment, the butting process, the temporary joining process, the auxiliary member arranging process, the inner friction stirring process, and the outer friction stirring process are performed in this order.

  Since the butting process and the temporary joining process are the same as those in the second embodiment, the description thereof is omitted. As shown in FIG. 12A, in the lid member arranging step, the auxiliary member 4 is arranged so as to cover the abutting portion J1 at the inner corner of the cylindrical member 2A and the lid member 3A in the same manner as in the second embodiment. . In this embodiment, since an auxiliary member arrangement | positioning process is performed after performing a temporary joining process, an auxiliary member arrangement | positioning process can be performed stably.

  In the inner friction stirrer step, friction stir welding is performed from the inner side of the cylindrical member 2A to the auxiliary member 4 and the butting portion J1 in the same manner as the inner friction stirrer step of the second embodiment. As shown in FIG. 12B, a plasticized region W1 is formed in the butt joint J1 by the inner friction stirring process.

  In the outer friction stirring step, friction stir welding is performed from the outside of the cylindrical member 2A to the butted portion J1 in the same manner as the outer friction stirring step of the second embodiment. In the outer friction agitation step, as shown in FIG. 12B, the insertion depth of the rotary tool F for main joining is set such that the plasticized region W2 and the plasticized region W1 formed in the outer friction agitation step are in contact with each other. It is preferable to set the length. Thereby, the whole depth direction of the butt | matching part J1 can be friction-stir-welded, and joining strength, watertightness, and airtightness can be improved.

  According to this embodiment described above, substantially the same effect as that of the second embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 Structure 1A Structure 2 Cylindrical member 2A Cylindrical member 3 Lid member 3A Lid member 4 Auxiliary member F Rotary tool for main joining G Rotary tool for temporary joining J1 Butt part R1 Weld metal W1 Plasticization area W2 Plasticization area

Claims (7)

A joining method of joining a metallic cylindrical member and a metallic lid member covering the opening of the cylindrical member,
A butting step of butting the tubular member and the lid member so that the outer circumferential surface of the cylindrical member and the outer circumferential surface of the lid member are flush with each other;
An outer friction agitation step of performing friction agitation from the outside of the cylindrical member with respect to the abutting portion;
A welding step of performing overlay welding from the inside of the tubular member to the butt portion;
After the outer friction stirring step, friction is applied from the inner side of the cylindrical member to the butted portion in a state where only the stirring pin is in contact with the cylindrical member, the lid member, and the weld metal formed by the overlay welding. An inner friction stirring step of stirring. A joining method of joining a metallic cylindrical member and a metallic lid member covering the opening of the cylindrical member,
A butting step of butting the tubular member and the lid member so that the outer circumferential surface of the cylindrical member and the outer circumferential surface of the lid member are flush with each other;
An outer friction agitation step of performing friction agitation from the outside of the cylindrical member with respect to the abutting portion;
An auxiliary member arranging step of arranging an auxiliary member at an inner corner constituted by the cylindrical member and the lid member;
After the outer friction agitation step, the inner friction agitation is performed from the inside of the cylindrical member to the abutting portion in a state where only the agitation pin is in contact with the cylindrical member, the lid member, and the auxiliary member. A bonding method comprising the steps of:   The joining method according to claim 1, further comprising a temporary joining step of temporarily joining the butted portion from the outside of the cylindrical member before the outer friction stirring step. A joining method of joining a metallic cylindrical member and a metallic lid member covering the opening of the cylindrical member,
A butting step of butting the tubular member and the lid member so that the outer circumferential surface of the cylindrical member and the outer circumferential surface of the lid member are flush with each other;
A welding step of performing overlay welding from the inside of the tubular member to the butt portion;
An inner friction agitation step in which friction agitation is performed from the inside of the cylindrical member to the butt portion in a state where only the agitation pin is in contact with the cylindrical member, the lid member, and the weld metal formed by overlay welding. When,
An outer friction stirring step of performing friction stirring on the butted portion from the outside of the cylindrical member after the inner friction stirring step.   The joining method according to claim 4, further comprising a temporary joining step of temporarily joining the butted portion from the outside of the tubular member before the welding step. A joining method of joining a metallic cylindrical member and a metallic lid member covering the opening of the cylindrical member,
A butting step of butting the tubular member and the lid member so that the outer circumferential surface of the cylindrical member and the outer circumferential surface of the lid member are flush with each other;
An auxiliary member arranging step of arranging an auxiliary member at an inner corner constituted by the cylindrical member and the lid member;
An inner friction agitation step in which friction agitation is performed from the inside of the cylindrical member to the butting portion in a state where only the agitation pin is in contact with the cylindrical member, the lid member and the auxiliary member;
An outer friction stirring step of performing friction stirring on the butted portion from the outside of the cylindrical member after the inner friction stirring step.   The joining method according to claim 6, further comprising a temporary joining step of temporarily joining the abutting portion from the outside of the cylindrical member before the auxiliary member arranging step.

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