JP4911157B2 - Method and structure for joining thick materials - Google Patents

Description

  The present invention relates to a method and a structure for joining thick materials to be joined without a gap.

  Patent Document 1 discloses a method of friction stir welding thick materials to be joined. As the procedure, first, as shown in FIG. 21 (A), a stepped portion 2 comprising an outer end surface 2a, an intermediate surface 2b, and an inner end surface 2c is provided at each joining end of a pair of thick workpieces 1 and 1. Form it. Then, as shown in FIG. 21 (B), the outer end surfaces 2a, 2a of the pair of thick workpieces 1, 1 are butted together to form a butted portion 3, and the friction stir welding is performed along the butted portion 3 By inserting the tool 10 and performing friction stir welding, both thick workpieces 1 and 1 are joined to form a joining line W1. Next, as shown in FIG. 21 (C), the concave portion 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of both thick-walled members 1, 1 is the same as or similar to the concave portion 4. A connecting plate 5 having a cross-sectional shape is inserted. Finally, as shown in FIG. 21 (D), the friction stir welding tool 10 is inserted along the butted portions 6 and 6 between the connecting plate 5 and the inner end surfaces 2c and 2c of the respective thick-walled members 1 and 1. Then, by performing friction stir welding, the joining lines W2 and W2 are formed. Thus, by performing friction stir welding in two stages in the thickness direction of the materials to be joined, thick materials to be joined that cannot be handled by existing joining tools can be joined together.

Japanese Patent No. 3307330 ([0013]-[0018], FIG. 1-2)

  However, in the joining structure joined by the above-described conventional method, as shown in FIG. 22, the bottom surface of the connection plate 5 and the bottom surface of the recess 4 (intermediate surfaces 2b and 2b of each thick material to be joined 1, 1) May remain unbonded and the gap 8 may remain. In addition, a tunnel-like cavity that is continuous in the direction of travel of the tool is formed in a joining line W2 formed by friction stir welding of the butted portion 6 between the connecting plate 5 and the inner end faces 2c, 2c of the thick-walled workpieces 1, 1. The defect 9 may remain. The gap 8 and the tunnel-like cavity defect 9 reduce the hermeticity of the portion. Therefore, when this junction structure is used in, for example, a vacuum processing container of a semiconductor manufacturing apparatus, leakage is likely to occur, There is a problem that it cannot be kept for a long time in an ultra-high vacuum state.

  The present invention has been made in view of such circumstances, and a thick-walled material joining method (hereinafter simply referred to as a “joining method”) and a thick-walled material to be joined together without gaps between the thick materials to be joined. It proposes a joining structure of materials (hereinafter simply referred to as “joining structure”).

That is, in the invention according to claim 1, the outer end surfaces of a pair of thick-joined materials in which stepped portions including an outer end surface, an intermediate surface, and an inner end surface are formed along the respective joining ends. A connecting plate having the same or similar cross-sectional shape as the concave portion is inserted into the concave portion formed by the first step of friction stir welding the butt portion and the intermediate surface and the inner end surface of the both thick workpieces. A second step and a third step of friction stir welding the abutting portions of the connection plate and the inner end face of each of the thick workpieces, and friction stir the boundary surface between the connection plate and the bottom surface of the recess And in the third step, the friction stir tool is moved from the vicinity of the center of the connecting plate toward the peripheral portion so as to draw a continuous trace of a spiral pattern in a plan view. .
According to a fourth aspect of the present invention, the outer end surfaces of a pair of thick materials to be joined in which step portions including an outer end surface, an intermediate surface, and an inner end surface are formed along the respective joining ends. A first step of inserting a connecting plate having a cross-sectional shape identical or similar to the concave portion into the concave portion formed by the intermediate surface and the inner end surface of the both thick-walled materials, and the pair of thick-walled materials Friction stir welding is performed on the butting portion formed by butting the outer end surfaces of the material and the butting portion between the connecting plate and the inner end surface of each thick-joined material, and the connecting plate and the bottom surface of the recess And a second step of friction stir the boundary surface between, and in the second step, the friction stir tool is a continuous trace of a spiral pattern in plan view from the vicinity of the center of the connecting plate toward the peripheral portion It is made to move so that it may draw.
The invention according to claim 7 includes a pair of thick members to be joined in which stepped portions including an outer end surface, an intermediate surface, and an inner end surface are formed along each joining end, and the outer end surfaces are abutted against each other. ,
A connecting plate having the same or similar cross-sectional shape as that of the concave portion, which is inserted into the concave portion formed by the intermediate surface and the inner end face of the both thick-walled materials, The abutting portion formed by abutting the outer side surfaces and the abutting portion between the connection plate and the inner end surface of each thick-joined material are friction stir welded, respectively, and the connection plate and the bottom surface of the recess A thick-wall-joined structure in which the boundary surface of the connection plate is friction-stirred, and frictional stirring of the boundary surface between the connection plate and the bottom surface of the recess is directed from the vicinity of the center of the connection plate toward the peripheral portion. It is characterized by being drawn so as to draw a continuous trace of a spiral pattern in plan view.

According to such a joining method or joining structure, since the boundary surface between the connection plate and the bottom surface of the recess, which has been left unjoined in the conventional joining method or joining structure, is integrated by friction stirring, A highly airtight joint with no gap can be formed.
Further, since the friction stir tool is moved from the central portion of the connecting plate toward the peripheral portion during friction stirring, the joining can be performed without entraining air remaining on the boundary surface. When joining from the peripheral part toward the center part, a tunnel-like defect due to air entrainment occurs.

Further, in such a joining method or structure, friction between the abutting portion formed by abutting the outer end surfaces of the pair of thick workpieces and the abutting portion between the connecting plate and the inner end surfaces of the respective thick workpieces. When the friction stirrer is performed on the boundary surface between the connection plate and the bottom surface of the recess after the stir welding is completed, the connection plate is easily positioned and fixed during the friction stir. Moreover, in the friction stirring of the said boundary surface, it is preferable to make a tool cross to the butt | matching part of the said connection plate and the inner side end surface of each said thick-walled to-be-joined material. Further, in such a joining method or joining structure, it is preferable not to leave a hole inevitable when the tool is pulled out in the connection plate.

  As described above, according to the present invention, the gap formed between the bottom surface of the connection plate and the bottom surface of the recess, and the joint formed by friction stir welding of the butted portion between the connection plate and the inner end surface of each thick-walled workpiece. Without leaving a tunnel-like cavity defect inside the wire, it is possible to obtain a highly airtight thick-joined material joining structure.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements, and duplicate descriptions are omitted. In addition, it is assumed that a thick aluminum plate is used as the thick member to be joined and the joining ability of the friction stir welding apparatus is 5 mm.

<First embodiment>
1-4 is sectional drawing showing each process of 1st embodiment of the joining method which concerns on this invention.
First, as shown in FIG. 1 (A), a pair of thick materials to be joined 1, 1 are brought into surface contact with their respective outer end faces 2a, 2a to form a butt portion 3 and are not shown. Restrain with a jig. The thickness of each thick member 1 is 5 to 10 mm, and the step portion 2 is formed along each joining end. The step portion 2 is formed to include an outer end surface 2a, an intermediate surface 2b, and an inner end surface 2c. Then, when the outer end surfaces 2a, 2a of the pair of thick members 1 and 1 are abutted with each other, the concave portions 4 are formed by the continuous intermediate surfaces 2b, 2b and the pair of opposed inner end surfaces 2c, 2c. Is done. Note that the thick-walled material 1 is made by cutting an aluminum rolled plate (AA5052 alloy, AA6061 alloy) or aluminum in which the step portion 2 is integrally formed in advance (JIS; A6063-T5 or T6). Extrusion shapes of

  Next, as shown in FIG. 1B, a tool 10 for friction stir welding is set on the butt 3. The tool 10 is made of tool steel, and includes a rotating cylindrical body 11 and an agitating pin 13 that hangs coaxially from the center of the surface pressing portion 12 that is the bottom surface of the rotating cylindrical body and is gently curved and recessed. The stirring pin 13 is slightly shorter than the height of the outer end surface 2a and the inner end surface 2c of the thick-walled workpiece 1, and a small screw-shaped friction stirring blade (not shown) is formed on the peripheral surface. 1 (C) and 1 (c), the central axes of the rotating cylindrical body 11 and the stirring pin 13 are slightly inclined along the abutting portions 3 of the respective thick-walled members 1 and 1. The tool 10 is rotated toward the butting portion 3 while being rotated by a motor (not shown). The rotation speed of the tool 10 is appropriately selected within the range of 300 to 5000 rpm. In addition, the thick materials 1 and 1 are constrained so as not to move in the longitudinal direction and the width direction in advance.

  Next, as shown in the drawing, the tool 10 is pressed in the vertical direction against each thick member 1 and the stirring pin 13 is pushed in until the entire surface pressing portion 12 reaches the surfaces of the intermediate surfaces 2b and 2b. In this state, the tool 10 is moved in the direction opposite to the inclined direction (leftward in FIG. 1C). This feed speed is appropriately selected within the range of 0.02 to 2 m / min. As the tool 10 rotates and moves, the metal in the vicinity of the butt 3 is heated and plasticized by the stirring pin 13, and the horizontal and vertical directions between the left and right thick workpieces 1 and 1 of the butt 3 are also shown. Fluidized.

  Further, the fluidized metal is given a constant pressure to the vertical flow by the surface pressing portion 12 of the tool 10 and is prevented from scattering from the vicinity of the surface of the butting portion 3 to the outside. As a result, as shown in FIGS. 1D and 1D, after the tool 10 passes, the fluidized metal is solidified from the fluidized state to become a joint line W1 having a substantially semi-elliptical cross section. . The surface of the bonding line W1 is slightly concaved by the surface pressing portion 12 by the width corresponding to the diameter, but becomes a bonding line W1 that is continuous along the butt portion 3 for a required length and has a flat surface. .

  Next, as shown in FIGS. 2 (A) and 2 (B), a recess formed by both continuous intermediate surfaces 2b and 2b of the thick material to be joined 1 and 1 and a pair of opposed inner end surfaces 2c and 2c. 4, a connecting plate 5 made of aluminum having the same cross section as the concave portion 4 is inserted, and a butt portion 6, between the connecting plate 5 and the inner end faces 2c, 2c of the respective thick-walled members 1, 1 is inserted. 6 is formed. Then, as shown in FIGS. 2C and 2D, friction stir welding is sequentially performed along the butt portions 6 and 6 using the tool 10 in the same manner as described above. As a result, as shown in FIG. 2 (E), a pair of parallel joining lines W2 and W2 for joining the connecting plate 5 and the respective thick-walled joined materials 1 and 1 are formed along the butted portions 6 and 6. Is done.

  Next, as shown in FIGS. 3 and 4 (A) and 4 (B), a friction stirring tool 20 is inserted from above the connection plate 5 and connected to the bottom surface (intermediate surfaces 2b, 2b) of the recess 4. The tool 20 is moved along the connecting plate 5 while integrating the boundary surface 7 with the bottom surface of the plate 5 by friction stirring. As shown in FIG. 5, the friction stirring tool 20 is made of tool steel, and includes a rotating cylindrical body 21 and a stirring pin 23 that hangs coaxially from the center of a surface pressing portion 22 that is a horizontal bottom surface thereof. Yes. The surface pressing portion 22 is formed with a ridge 24 that protrudes from its periphery toward the base end portion of the stirring pin 23 in a spiral shape of approximately two turns in a bottom view. The ridges 24 are formed in such a direction that the plasticized metal is forcibly collected toward the base end of the stirring pin 23 when the tool 20 rotates in the direction indicated by the arrow in FIG. Has been. Further, a small screw-shaped friction stirring blade 25 is formed on the peripheral surface of the stirring pin 23. When the tool 20 rotates in the direction indicated by the arrow in FIG. 5B, the friction stirring blade 25 moves the plasticized metal upward from below (from the tip of the stirring pin 23 to the surface pressing portion 22). It is formed in such a direction as to forcibly collect.

  Then, the central axis of the rotating cylindrical body 21 and the stirring pin 23 is inclined in a direction perpendicular to the surface of the connection plate 5 or slightly inclined, and the tool 20 is rotated toward the connection plate 5 by a motor (not shown). As the tool 20 rotates, the metal in the vicinity of the boundary surface 7 between the bottom surface (intermediate surface 2b, 2b) of the recess 4 and the bottom surface of the connection plate 5 is heated and plasticized by the stirring pin 23, and is horizontal in the portion. And the metal of the thick materials 1 and 1 near the bottom surface of the recess 4 and the metal near the bottom surface of the connection plate 5 are integrated to close a fine gap on the boundary surface 7. . Then, by moving the tool 20 sequentially along the entire surface of the connection plate 5 while pressing the surface of the connection plate 5 with the surface pressing portion 22, it is possible to close all the minute gaps on the boundary surface 7.

Here, as shown in FIGS. 3 and 4B, the tool 20 can be moved so as to draw a spiral trace in a plan view from the vicinity of the center of the connecting plate 5 toward the peripheral edge. For example, the air remaining on the boundary surface can be joined without being caught in the joint portion, and further, holes that are unavoidable when the tool 20 is pulled out can be prevented from remaining in the connection plate 5.
Of course, the movement trajectory of the tool 20 is not limited to this. For example, as shown in FIG. 6A, the tool 20 may be moved in a direction parallel to the joining line W2 while repeating the U-turn. As shown in FIG. 6B, the U-turn may be repeated and moved in a direction orthogonal to the joining line W2, or a movement pattern other than these may be used. Although it may be continuous or discontinuous, it is important that the tool 20 passes through the entire surface of the connection plate 5 so as to divide the continuity of the gap of the boundary surface 7 in the direction of the joint line W2. .

When the friction stirring by the tool 20 is completed, as shown in FIG. 7A, the connecting plate 5 becomes the stirring portion W3 that is formed after the tool 20 has passed. Since the stirring portion W3 is formed so as to include the boundary surface 7, the bottom surface of the concave portion 4 and the metal of the connection plate 5 are integrated, and a joining structure in which a minute gap in the boundary surface 7 is blocked can be obtained. .
In addition, as shown to FIG. 7 (B), it is so that the butt | matching parts 6 and 6 (joining line W2, W2) of the connection board 5 and the inner side end surfaces 2c and 2c of each thick to-be-joined material 1 and 1 may be crossed. If the tool 20 is moved, not only the gap of the boundary surface 7 is blocked, but also the tunnel-like cavity defect in the joining lines W2, W2 is divided by the stirring part W3. Become.

<Second embodiment>
FIG. 8 is a cross-sectional view showing each step of the second embodiment of the joining method according to the present invention. This embodiment is basically the same as the first embodiment, but differs only in the order of the friction stir welding of the butt portions 6 and 6 and the friction stirring of the boundary surface 7.
That is, first, as shown in FIG. 8 (A), a pair of thick members to be joined 1 in which stepped portions 2 including an outer end surface 2a, an intermediate surface 2b, and an inner end surface 2c are formed along the respective joining ends. The outer end surfaces 2a, 2a of the first one are butted together to form a butted portion 3, and the butted portion 3 is friction stir welded to form a joining line W1.
Next, as shown in FIG. 8 (B), a connection having the same cross-sectional shape as that of the recess 4 is made to the recess 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of the both thick workpieces 1, 1. After inserting the plate 5, a friction stirring tool 20 is inserted from above the connection plate 5, and the boundary surface 7 between the bottom surface (intermediate surface 2 b, 2 b) of the recess 4 and the bottom surface of the connection plate 5 is friction stirred. And agitation part W3 including boundary surface 7 is formed.
Finally, as shown in FIG. 8C, the abutting portions 6 and 6 between the connection plate 5 and the inner end faces 2c and 2c of the respective thick-walled members 1 and 1 are friction stir welded sequentially or simultaneously.

As in the first embodiment, the joint structure obtained in this way is also highly airtight, in which the bottom surface of the recess 4 and the metal of the connection plate 5 are integrated, and the minute gaps on the boundary surface 7 are blocked. It has become.
Unlike the first embodiment, when the boundary surface 7 between the bottom surface of the recess 4 and the bottom surface of the connection plate 5 is integrated by friction stirring, the connection plate 5 is firmly restrained so as not to move. There is a need.

<Third embodiment>
FIG. 9 is a cross-sectional view showing each process of the third embodiment of the joining method according to the present invention. This embodiment is basically the same as the second embodiment, but differs only in the insertion direction of the tool during friction stirring of the boundary surface 7.
That is, first, as shown in FIG. 9 (A), a pair of thick-walled members 1, each having a step portion 2 including an outer end surface 2a, an intermediate surface 2b, and an inner end surface 2c along each joining end. The outer end surfaces 2a, 2a of the first one are butted together to form a butted portion 3, and the butted portion 3 is friction stir welded to form a joining line W1.
Next, as shown in FIG. 9 (B), a connection having the same cross-sectional shape as that of the recess 4 is made to the recess 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of the both thick workpieces 1, 1. After inserting the plate 5, the friction stirring tool 20 is inserted from below the connecting plate 5 (on the joining line W <b> 1 side), and the boundary between the bottom surface (intermediate surfaces 2 b, 2 b) of the concave portion 4 and the bottom surface of the connecting plate 5. The surface 7 is integrated by frictional stirring to form a stirring portion W3 including the boundary surface 7.
Finally, as shown in FIG. 9C, the abutting portions 6 and 6 between the connecting plate 5 and the inner end surfaces 2c and 2c of the respective thick-walled members 1 and 1 are friction stir welded sequentially or simultaneously.

<Fourth embodiment>
FIG. 10 is a cross-sectional view showing each process of the fourth embodiment of the joining method according to the present invention. This embodiment is basically the same as the first embodiment, but differs only in the order of the friction stir welding of the butt portions 6 and 6 and the friction stirring of the boundary surface 7.
That is, first, as shown in FIG. 10 (A), a pair of thick members to be joined 1, each having a step portion 2 including an outer end face 2a, an intermediate face 2b, and an inner end face 2c along each joining end. The outer end surfaces 2a, 2a of the first one are butted together to form a butted portion 3, and the butted portion 3 is friction stir welded to form a joining line W1.
Next, as shown in FIGS. 10B and 10C, the concave portion 4 formed by the intermediate surfaces 2b and 2b and the inner end surfaces 2c and 2c of the both thick materials 1 and 1 is the same as the concave portion 4. After inserting the connection plate 5 having a cross-sectional shape, a friction stirring tool 20 is inserted from above the connection plate 5, and a boundary surface 7 between the bottom surface (intermediate surfaces 2 b, 2 b) of the recess 4 and the bottom surface of the connection plate 5. And abutting portions 6 and 6 between the connecting plate 5 and the inner end faces 2c and 2c of the thick-walled workpieces 1 and 1 are friction stir welded. That is, the friction stir welding of the butt portions 6 and 6 and the friction stir welding of the boundary surface 7 are not distinguished, and the friction stirrer is performed so as to include the butt portions 6 and 6, so The joining with the materials 1 and 1 and the formation of the stirring portion W3 including the boundary surface 7 are performed simultaneously. Therefore, it is possible to simplify the work process.

<Fifth embodiment>
FIG. 11 is a cross-sectional view showing each process of the fifth embodiment of the joining method according to the present invention. This embodiment is different from the above embodiments only in the joining timing of the butting portion 3.
That is, first, as shown in FIG. 11 (A), a pair of thick materials 1 and 1 in which step portions including the outer end surface 2a, the intermediate surface 2b, and the inner end surface 2c are formed along the respective joining ends. The outer end surfaces 2a, 2a of each other are butted together to form a butting portion 3, and the recess formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of both thick-walled materials 1, 1 is identical to the recess. The connecting plate 5 having the cross-sectional shape is inserted.
Next, as shown in FIG. 11B, a friction stir welding tool is inserted from below, and the butted portion 3 is friction stir welded to form a joining line W1.
Subsequently, as shown in FIG. 11C, a friction stir welding tool is inserted from above, and the butted portions 6 and 6 are friction stir welded to form joint lines W2 and W2.
Finally, as shown in FIG. 11D, a friction stir tool is inserted from above, and the boundary surface 7 between the bottom surface (intermediate surfaces 2b, 2b) of the recess and the bottom surface of the connecting plate 5 is friction stir to integrate. And a stirring portion W3 including the boundary surface 7 is formed. The friction stir tool can be inserted from below.

  In addition, the order of FIG. 11 (B)-(D) after FIG. 11 (A) can be changed arbitrarily, and should just form joining lines W1, W2 and the stirring part W3 finally.

<Sixth embodiment>
FIG. 12 is a cross-sectional view showing each process of the sixth embodiment of the joining method according to the present invention. In the present embodiment, two stepped portions 2 and 2 ′ are formed on the upper surface side along the joining ends of the thick-walled workpieces 1 and 1.
As shown in FIG. 12 (A), the thick materials 1 and 1 have a thickness of 10 to 15 mm, and two stepped portions 2 and 2 'are formed along the respective joining ends. The step portion 2 is formed by the outer end surface 2a, the first intermediate surface 2b, and the first inner end surface 2c, and the step portion 2 ′ is formed by the first inner end surface 2c, the second intermediate surface 2b ′, and the second inner end surface 2c ′. Is formed. And the abutting part 3 is formed by abutting the outer end faces 2a, 2a of such a pair of thick workpieces 1,1. Then, a narrow concave portion 4 is formed by the first intermediate surfaces 2b, 2b and the first inner end surfaces 2c, 2c, and the second intermediate surfaces 2b ′, 2b ′ and the second inner end surfaces 2c ′, 2c ′ are wide. Is formed.
Subsequently, as shown in FIG. 12 (B), after the connecting plate 5 having the same cross-sectional shape as the concave portion 4 is inserted into the concave portion 4, the friction of the butted portions 3, 6, 6 is the same as in the above embodiments. While forming the joining lines W1 and W2 by stirring joining, the stirring part W3 is formed by friction stirring of the boundary surface 7. FIG.
Finally, as shown in FIG. 12C, after inserting the connecting plate 5 ′ having the same cross-sectional shape as the recessed portion 4 ′ into the recessed portion 4 ′, the connecting plate 5 ′ and The abutting portions 6 'and 6' between the thick inner members 1 and 1 and the second inner end surfaces 2c 'and 2c' are friction stir welded, and the bottom surface of the connection plate 5 'and the bottom surface of the recess 4' (first The agitating portion W3 is formed by frictional stirring of the boundary surface 7 ′ between the two intermediate surfaces 2b ′ and 2b ′ and the upper surface of the connecting plate 5).

<Seventh embodiment>
FIG. 13 is a cross-sectional view showing each process of the seventh embodiment of the joining method according to the present invention. In this embodiment, the step part 2 formed along the joining end of each thick material 1 and 1 has the wide bottom ditch | groove 2d. That is, as shown in FIG. 13A, the step portion 2 is formed by the outer end surface 2a, the intermediate surface 2b, the wide groove 2d, and the inner end surface 2c.
First, as shown in the figure, the outer end faces 2a, 2a of the pair of thick workpieces 1, 1 are butted together to form a butted portion 3, and the butted portion 3 is friction stir welded to join line W1. Form.
Next, as shown in FIG. 13 (B), in the concave portion 4 formed by the intermediate surfaces 2b, 2b, the inner end surfaces 2c, 2c, and the wide concave grooves 2d, 2d of the both thick materials 1 and 1, After the connecting plate 5 having the same cross-sectional shape as that of the recess 4 is slide-inserted, the abutting portions 6 and 6 between the connecting plate 5 and the inner end surfaces 2c and 2c of the thick-walled workpieces 1 and 1 are friction stir welded. . The connecting plate 5 has wide bottom ridges 5d and 5d that fit into the wide bottom grooves 2d and 2d.
Finally, as shown in FIG. 13C, a friction stir tool is inserted from above the connection plate 5 and connected to the bottom surface of the concave portion 4 (the bottom surfaces of the intermediate surfaces 2b and 2b and the wide bottom concave grooves 2d and 2d). Friction stirring is performed on the boundary surface 7 with the bottom surface of the plate 5 to form a stirring portion W3.

  As described above, the boundary surface 7 in the present invention is not limited to a single horizontal plane, and may have any aspect such as one having two or more horizontal planes. Further, the order of FIGS. 13A to 13C can be changed as appropriate.

<Eighth embodiment>
FIG. 14 is a cross-sectional view showing each process of the eighth embodiment of the joining method according to the present invention. In this embodiment, the thickness of one thick workpiece 1 of the pair of thick workpieces to be joined is larger than the thickness of the other thick workpiece 1 '. That is, as shown in FIG. 14A, a stepped portion 2 including an outer end surface 2a, an intermediate surface 2b, and an inner end surface 2c is formed at the joining end of one thick workpiece 1 and the other end A stepped portion 2 'composed of an outer end surface 2a, an intermediate surface 2b, and an inner end surface 2c' is formed at the joining end of the thick-walled workpiece 1 '. The inner end surface 2c has a height equal to the inner end surface 2c'. Greater than the height of
First, as shown in the figure, the outer end surfaces 2a, 2a of the pair of thick workpieces 1, 1 'are butted together to form a butted portion 3, and the butted portion 3 is friction stir welded to form a joining line. W1 is formed.
Next, as shown in FIG. 14 (B), the concave portion 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c 'of both thick-walled members 1, 1' has a cross-sectional shape similar to the concave portion 4. After the connecting plate 5 is inserted, the abutting portions 6 and 6 ′ between the connecting plate 5 and the inner end surfaces 2c and 2c ′ of the thick-walled members 1 and 1 ′ are friction stir welded. The first horizontal surface 5a, the second horizontal surface 5b, and the first horizontal surface 5a are such that the upper surface of the connecting plate 5 has the same height as the upper surfaces of the thick materials 1 and 1 'when inserted into the recess 4. And a slope 5c connecting the second horizontal surface 5b.
Finally, as shown in FIG. 14C, a friction stir tool is inserted from above the connection plate 5, and the boundary surface 7 between the bottom surface (intermediate surfaces 2 b, 2 b) of the recess 4 and the bottom surface of the connection plate 5 is formed. Friction stirring is performed to form the stirring portion W3.

  As described above, the present invention can be applied to a case where the thickness of the pair of thick members to be joined is different. In addition, the order of FIGS. 14A to 14C can be changed as appropriate.

<Ninth embodiment>
FIG. 15 is a cross-sectional view showing each process of the ninth embodiment of the joining method according to the present invention. In the present embodiment, step portions 2 and 2 ′ are formed on both the upper and lower sides along the joining ends of the respective thick-walled workpieces 1 and 1.
As shown in FIG. 15 (A), the thick members 1 and 1 have a thickness of 10 to 15 mm, and an upper step portion 2 and a lower step portion 2 ′ are formed along the joining ends. The upper step 2 is formed by an outer end surface 2a, a first intermediate surface 2b, and a first inner end surface 2c, and the lower step 2 'is formed by an outer end surface 2a, a second intermediate surface 2b', and a second inner end surface 2c '. And is formed. Then, the outer end surfaces 2a, 2a of such a pair of thick members 1 and 1 are butted together to form a butted portion 3, and the butted portion 3 is friction stir welded to form a joining line W1.
Next, as shown in FIG. 15 (B), the concave portion 4 formed by the first intermediate surfaces 2b, 2b and the first inner end surfaces 2c, 2c of both thick-walled workpieces 1, 1 is identical to the concave portion 4. After inserting the connecting plate 5 having a cross-sectional shape, the abutting portions 6 and 6 between the connecting plate 5 and the first inner end surfaces 2c and 2c of the respective thick-walled workpieces 1 and 1 are friction stir welded and joined. W2 and W2 are formed. In addition, a connection having the same cross-sectional shape as that of the recess 4 ′ is formed in the recess 4 ′ formed by the second intermediate surfaces 2b ′ and 2b ′ and the second inner end surfaces 2c ′ and 2c ′. After inserting the plate 5 ′, the abutting portions 6 ′ and 6 ′ between the connecting plate 5 ′ and the second inner end surfaces 2c ′ and 2c ′ of the thick-walled members 1 and 1 are friction stir welded. Bonding lines W2 and W2 are formed.
Finally, as shown in FIG. 15 (C), the boundary surface 7 between the bottom surface of the connection plate 5 and the bottom surface of the recess 4 (first intermediate surfaces 2b, 2b) is frictionally stirred to form a stirring portion W3 and connected. The stirrer W3 is formed by frictional stirring of the boundary surface 7 'between the bottom surface of the plate 5' (upper surface in the figure) and the bottom surface of the recess 4 (second intermediate surfaces 2b ', 2b').

  Thus, this invention can respond also to the case where the step part is formed in the up-and-down both sides along the joining end of each thick material to be joined. Further, the order of FIGS. 15B and 15C can be changed as appropriate.

<Tenth embodiment>
FIG. 16 is a cross-sectional view showing each process of the tenth embodiment of the joining method according to the present invention.
As shown in FIG. 16 (A), the thick materials 1 and 1 have a thickness of 10 to 15 mm, and a step portion 2 is formed along the joining end. The step portion 2 is formed by an outer end surface 2a having a large height (5 to 10 mm), an intermediate surface 2b, and an inner end surface 2c having a small height (5 mm or less). Then, the abutting portion 3 is formed by abutting the outer end faces 2a, 2a of such a pair of thick workpieces 1 and 1, and a tool for friction stir welding is inserted into the abutting portion 3 from above and below. Friction stir welding is performed to form the joining lines W1, W1.
Next, as shown in FIG. 16 (B), a connection having the same cross-sectional shape as that of the recess 4 is made to the recess 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of the both thick workpieces 1, 1. After the plate 5 is inserted, the abutting portions 6 and 6 between the connecting plate 5 and the inner end surfaces 2c and 2c of the thick-walled workpieces 1 and 1 are friction stir welded to form joint lines W2 and W2. .
Finally, as shown in FIG. 16C, the agitating portion W3 is formed by frictional stirring of the boundary surface 7 between the bottom surface of the connection plate 5 and the bottom surface (intermediate surfaces 2b, 2b) of the recess 4.

  As described above, the present invention can also be applied to a case where the height of the outer end face of the step portion formed along the joining end of each thick-walled workpiece is large. In addition, the order of FIGS. 16B and 16C can be changed as appropriate.

<Eleventh embodiment>
FIG. 17 is a cross-sectional view showing each process of the eleventh embodiment of the joining method according to the present invention. In the present embodiment, step portions 2 and 2 ′ are formed on the upper and lower surfaces along the joining ends of the thick-walled materials 1 and 1, respectively.
As shown in FIG. 17 (A), the thick members 1 and 1 have a thickness of 15 to 20 mm, and an upper step 2 and a lower step 2 ′ are formed along the joining ends. The upper step 2 is formed by an outer end surface 2a, a first intermediate surface 2b, and a first inner end surface 2c, and the lower step 2 'is formed by an outer end surface 2a, a second intermediate surface 2b', and a second inner end surface 2c '. And is formed. The height of the outer end surface 2a is 5 to 10 mm. Then, the abutting portion 3 is formed by abutting the outer end faces 2a, 2a of such a pair of thick workpieces 1 and 1, and a tool for friction stir welding is inserted into the abutting portion 3 from above and below. Friction stir welding is performed to form the joining lines W1, W1.
Next, as shown in FIG. 17 (B), the concave portion 4 formed by the first intermediate surfaces 2b, 2b and the first inner end surfaces 2c, 2c of both thick-walled workpieces 1, 1 is identical to the concave portion 4. After inserting the connecting plate 5 having a cross-sectional shape, the abutting portions 6 and 6 between the connecting plate 5 and the first inner end surfaces 2c and 2c of the respective thick-walled workpieces 1 and 1 are friction stir welded and joined. W2 and W2 are formed. In addition, a connection having the same cross-sectional shape as that of the recess 4 ′ is formed in the recess 4 ′ formed by the second intermediate surfaces 2b ′ and 2b ′ and the second inner end surfaces 2c ′ and 2c ′. After inserting the plate 5 ′, the abutting portions 6 ′ and 6 ′ between the connecting plate 5 ′ and the second inner end surfaces 2c ′ and 2c ′ of the thick-walled members 1 and 1 are friction stir welded. Bonding lines W2 and W2 are formed.
Finally, as shown in FIG. 17 (C), the boundary surface 7 between the bottom surface of the connection plate 5 and the bottom surface of the recess 4 (first intermediate surfaces 2b, 2b) is frictionally stirred to form a stirring portion W3 and connected. The stirrer W3 is formed by frictional stirring of the boundary surface 7 'between the bottom surface of the plate 5' (upper surface in the figure) and the bottom surface of the recess 4 (second intermediate surfaces 2b ', 2b').

  Thus, this invention can respond also to the case where step portions are formed on both the upper and lower sides along the joining ends of the respective thick-walled materials and the height of the outer end face is large. In addition, the order of FIGS. 17B and 17C can be changed as appropriate.

<Twelfth embodiment>
FIG. 18 is a cross-sectional view showing each process of the twelfth embodiment of the joining method according to the present invention. The present embodiment is basically the same as the first to fifth embodiments, but differs only in that each thick-walled material is a curved plate material.
That is, as shown in FIG. 18 (A), a pair of thick members to be joined 1, 1 in which a step portion 2 including an outer end surface 2a, an intermediate surface 2b, and an inner end surface 2c is formed along each joining end. The outer end surfaces 2a, 2a are butted together to form a butted portion 3, and the butted portion 3 is friction stir welded to form a joining line W1. The intermediate surface 2b is a curved surface.
Next, as shown in FIG. 18 (B), a connection having the same cross-sectional shape as that of the recess 4 is made to the recess 4 formed by the intermediate surfaces 2b, 2b and the inner end surfaces 2c, 2c of the both thick workpieces 1, 1. After the plate 5 is inserted, the abutting portions 6 and 6 between the connecting plate 5 and the inner end surfaces 2c and 2c of the thick-walled workpieces 1 and 1 are friction stir welded to form joint lines W2 and W2. .
Finally, as shown in FIG. 18C, the boundary surface 7 between the bottom surface (intermediate surfaces 2b, 2b) of the recess 4 and the bottom surface of the connection plate 5 is integrated by frictional stirring, and the stirring unit including the boundary surface 7 is obtained. W3 is formed.

  As described above, the present invention can also be applied to the case where each thick-walled material has a curved plate shape. In addition, the order of FIGS. 18A to 18C can be changed as appropriate.

<About tools>
The friction stirring tool 20 used in each of the above embodiments can be changed as appropriate. For example, in the friction stirring tool 20 ′ shown in FIG. 19, a cylindrical stirring pin 23 is suspended from a position shifted from the center of the surface pressing portion 22 that is the bottom surface of the rotating cylindrical body 21. When the stirring pin 23 is eccentric with respect to the rotating cylinder 21 in this way, when the rotating cylinder 21 is rotated around its axis, the stirring pin 23 rotates and revolves around the axis of the rotating cylinder 21. Therefore, the stirring action of the boundary surface 7 increases. Since the screw-shaped small friction stirring blade 25 is formed on the peripheral surface of the stirring pin 23, the stirring pin 23 can be fixed to the rotating cylindrical body 22 using the friction stirring blade 25. The projecting length of can be easily adjusted.

  Furthermore, the tools shown in FIGS. 20A to 20E can be used. In the tool 20 </ b> A of FIG. 20A, a polygonal columnar stirring pin 23 hangs down from a position shifted from the center of the surface pressing portion 22 that is the bottom surface of the rotating cylindrical body 21, and the surface pressing portion 22. A ridge 24 that protrudes in a spiral shape from the peripheral edge to the proximal end of the stirring pin 23 is formed. In each of the tools 20B to 20E shown in FIGS. 20B to 20E, the substantially cylindrical stirring pin 23 is suspended from a position shifted from the center of the surface pressing portion 22 which is the bottom surface of the rotating cylindrical body 21 (eccentrically). In addition, the tool 20B has a cross-shaped projection 26 formed on the bottom surface of the stirring pin 23, and the tool 20C has a large number of fine rectangular parallelepiped protrusions 27, 27,. The tool 20D is formed with concentric ring-shaped protrusions 28, 28,... On the bottom surface of the stirring pin 23, and the tool 20E has a plurality of concave portions near the bottom surface of the peripheral surface of the stirring pin 23. Grooves 29, 29,... Are formed. All of these tools increase the stirring action of the boundary surface 7.

  In each of the above-described embodiments, the friction stir welding tool 10 and the friction stir tool 20 are separate, but of course, both the friction stir welding and the friction stirring may be performed with the same tool. .

(A)-(D) is sectional drawing showing each process of 1st embodiment of the joining method which concerns on this invention, respectively, (c) is cc sectional drawing of (C), (d) is (D) It is a dd sectional view of). (A)-(E) are sectional drawings showing each process of 1st embodiment of the joining method which concerns on this invention, respectively. It is a perspective view showing 1 process of 1st embodiment of the joining method which concerns on this invention. (A) is a sectional view taken along the line aa of FIG. 3, and (B) is a plan view of FIG. (A) is a side view of the friction stir tool, (B) is a bottom view of (A), and (C) is a CC cross-sectional view of (B). (A), (B) is a top view showing another example of the movement locus | trajectory of a friction stirring tool, respectively. (A), (B) is sectional drawing showing the state after the completion of a movement of a friction stirring tool, respectively. (A)-(C) are sectional drawings showing each process of 2nd embodiment of the joining method which concerns on this invention, respectively. (A)-(C) are sectional drawings showing each process of 3rd embodiment of the joining method which concerns on this invention, respectively. (A)-(C) are sectional drawings showing each process of 4th embodiment of the joining method which concerns on this invention, respectively. (A)-(D) are sectional drawings showing each process of 5th embodiment of the joining method which concerns on this invention, respectively. (A)-(C) are sectional drawings showing each process of 6th embodiment of the joining method which concerns on this invention, respectively. (A)-(C) are sectional drawings showing each process of 7th embodiment of the joining method which concerns on this invention, respectively. (A)-(C) are sectional drawings showing each process of 8th embodiment of the joining method which concerns on this invention, respectively. (A)-(C) are sectional drawings showing each process of 9th embodiment of the joining method which concerns on this invention, respectively. (A)-(C) are sectional drawings showing each process of 10th Embodiment of the joining method which concerns on this invention, respectively. (A)-(C) are sectional drawings showing each process of 11th Embodiment of the joining method which concerns on this invention, respectively. (A)-(C) are sectional drawings showing each process of 12th embodiment of the joining method which concerns on this invention, respectively. (A) is a perspective view showing another example of the tool for friction stirring, (B) is the same sectional drawing. (A)-(E) are perspective views showing another example of the tool for friction stirring, respectively. (A)-(D) are sectional drawings showing each process of the conventional joining method. FIG. 21 is a partially enlarged perspective view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Thick to-be-joined material 2 ... Step part 2a ... Outer end surface 2b ... Intermediate | middle surface 2c ... Inner end surface 2d ... Bottom wide recessed groove 3 ... Butting part 4 ... Recessed part 5 ... Connection plate 5a ... First horizontal surface 5b ... Second horizontal surface 5c ... Slope 5d ... Wide ridge 6 ... Butt part 7 ... Interface 8 ... Gap 10 ... Tool (for friction stir welding) 11 ... Rotating cylindrical body 12 ... Surface pressing part 13 ... Stirring pin 20 ... (For friction stirring) Tool 21 ... Rotating cylindrical body 22 ... Surface pressing part 23 ... Stirring pin 24 ... Convex streak 25 ... Friction stirrer blade 26 ... Convex streak 27 ... Protrusion 28 ... Protrusion 29 ... Concave groove W1, W2 ... Joining line W3 ... Stirring part

Claims (9)

A first part that abuts the outer end surfaces of a pair of thick-walled members formed with stepped portions including an outer end surface, an intermediate surface, and an inner end surface along each joining end, and friction stir welds the butted portions. Process,
A second step of inserting a connection plate having the same or similar cross-sectional shape as the concave portion into the concave portion formed by the intermediate surface and the inner end surface of the both thick-walled materials;
And a third step of friction stir welding the abutting portion between the connection plate and the inner end face of each thick-walled material, and friction stir the boundary surface between the connection plate and the bottom surface of the recess,
In the third step, the thick stir material is characterized in that the friction stir tool is moved from the vicinity of the center of the connection plate toward the peripheral edge so as to draw a continuous trace of a spiral pattern in plan view. Joining method. In the third step, after the friction stir welding is performed on the abutting portion between the connection plate and the inner end surface of each thick-walled material, the boundary surface between the connection plate and the bottom surface of the recess is frictionally stirred . 2. The thick-walled material joining according to claim 1 , wherein in the friction stirring of the boundary surface, the tool is traversed at a butt portion between the connection plate and the inner end surface of each thick-walled material. Method. 3. The thick-joined material according to claim 1, wherein in the third step, a hole that is inevitably formed when the tool is pulled out is not left in the connection plate. 4. Joining method. While abutting the outer end surfaces of a pair of thick-walled members formed with stepped portions including an outer end surface, an intermediate surface, and an inner end surface along the respective joining ends, A first step of inserting a connection plate having the same or similar cross-sectional shape as the recess into the recess formed by the surface and the inner end surface;
The friction stir welding is performed for each of the butted portion formed by butting the outer end surfaces of the pair of thick-walled materials, and the butted portion of the connection plate and the inner end surface of each thick-walled material, and A second step of friction stirring the interface between the connection plate and the bottom surface of the recess,
In the second step, the thick stir material is characterized in that the friction stir tool is moved so as to draw a continuous trace of a spiral pattern in plan view from the vicinity of the center of the connecting plate toward the peripheral edge. Joining method. In the second step, friction agitation is performed for each of a butting portion formed by butting the outer end surfaces of the pair of thick-walled materials and a butting portion between the connection plate and the inner end surface of each thick-walled material. After joining, friction stir the boundary surface between the connection plate and the bottom surface of the recess, the friction stir of the boundary surface, at the butt portion between the connection plate and the inner end surface of each thick material to be joined The method of joining thick workpieces according to claim 4 , wherein the tool is traversed . 6. The thick-joined material according to claim 4, wherein in the second step, a hole that is inevitably formed when the tool is pulled out is not left in the connection plate. 7. Joining method. A stepped portion including an outer end face, an intermediate face and an inner end face is formed along each joining end, and a pair of thick materials to be joined in which the outer end faces are abutted with each other;
A connecting plate having a cross-sectional shape that is the same as or similar to that of the concave portion, which is inserted into the concave portion formed by the intermediate surface and the inner end surface of the both thick-walled workpieces,
The abutting portion formed by abutting the outer surfaces of the both thick-walled materials, and the abutting portion between the connection plate and the inner end surface of each thick-walled material are respectively friction stir welded, and The boundary surface between the connection plate and the bottom surface of the recess is frictionally stirred, and is a thick-walled material joining structure,
Friction stirring at the boundary surface between the connection plate and the bottom surface of the concave portion is performed so as to draw a continuous locus of a spiral pattern in plan view from the vicinity of the center of the connection plate toward the peripheral portion. A joining structure of thick-walled workpieces. After the abutting portion formed by abutting the outer surfaces of the both thick-walled materials and the abutting portion between the connection plate and the inner end surface of each thick-walled material, the connection is performed after the friction stir welding, respectively. Friction agitation at the boundary surface between the plate and the bottom surface of the recess is performed, and the frictional agitation at the boundary surface is performed across the abutting portion between the connection plate and the inner end surface of each thick-walled material. structure for joining thick welded material according to claim 7, characterized in that there. The thick-walled material according to claim 7 or 8, wherein in the frictional stirring of the boundary surface, holes that are inevitably formed when the tool is pulled out do not remain in the connection plate. Bonding structure.

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