Fixture for friction stir welding, and friction stir welding method

Abstract

To provide a jig for friction stir welding and a friction stir welding method that can suppress deformation due to temperature rise in two members joined by friction stir welding more effectively than conventional methods. [Solution] An embodiment to which the present invention is applied is a joining support jig 50 for friction stir welding, which supports at least one of the first member 10 and the second member 20 when a joining member 30 is formed by joining the first member 10 and the second member 20 by friction stir welding, and the jig 50 for friction stir welding is characterized by comprising a flow path 55 through which coolant flows to cool the vicinity of the joint 37 formed in the first member 10 and the second member 20.

Description

Technical Field

[0004] , ,

[0005] , , ,

[0001] The present invention relates to a jig for friction stir welding for supporting two members to be joined and a friction stir welding method in friction stir welding by a friction stir welding apparatus.

Background Art

[0002] Conventionally, when performing friction stir welding using a friction stir welding apparatus, there has been a technique of using a support jig to fix the positions of two members to be joined. Specifically, there has been a technique in which a first workpiece 21 and a second workpiece 22, which are joined members, are joined by a friction stir welding tool 14 (such as a probe 26) of a friction stir welding apparatus 10 in a state of being laminated on a support jig 12 (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in such a conventional technique, due to the temperature rise in friction stir welding, deformation or the like occurs in the two members to be joined, and it has been impossible to obtain a desired shape for the joined member formed by joining the two members or the joined structure formed by machining the joined member. That is, in friction stir welding, there has been a need for a technique that can prevent the occurrence of deformation or the like due to the temperature rise of the two members to be joined and manufacture a joined member having a desired shape more than before.

[0005] The present invention has been made in view of such problems, and one of its objects is to provide a jig for friction stir welding and a friction stir welding method that can suppress deformation or the like due to temperature rise in two members joined by friction stir welding more than before. [Means for solving the problem]

[0006] The present invention has been made to solve at least some of the above-mentioned problems and can be realized in the following examples of applications. The reference numerals and supplementary explanations in parentheses in this section are provided to aid in understanding the present invention and indicate its correspondence with the embodiments described later; they do not limit the present invention in any way.

[0007] An example application of the present invention is a jig for friction stir welding (joining support jig 50), which supports at least one of the first member (first member 10) and the second member (second member 20) when a joined member (joining member 30) is formed by friction stir welding, and the jig comprises a cooling section (flow channel section 55) for cooling the vicinity of the joint (joining section 37) formed in the first member and the second member.

[0008] Furthermore, in the friction stir welding jig of the above-described application example, the cooling section may be provided at a position where at least a portion overlaps with the portion constituting the joined structure (joint structure 1) when the joined structure is formed by a removal process on the joining member, in the direction in which the probe (joint tool 3) is pushed in. Moreover, in the friction stir welding jig of the above-described application example, the cooling section may be provided at a position where it does not overlap with the joined portion in the direction in which the probe is pushed in. Furthermore, in the friction stir welding jig of the above-described application example, the cooling section cools the vicinity of the stirring section (stirring section 35) which is formed by stirring with the probe and includes the joined portion in part, and at least a portion of it may be provided at a position where it does not overlap with the stirring section in the direction in which the probe is pushed in. Furthermore, in the friction stir welding jig of the above-described application example, the cooling section may have a flow path (flow path section 55) through which coolant flows near the joined portion.

[0009] An example of a friction stir welding method to which the present invention is applied is a friction stir welding method to form a joined member (joined member 30) by joining a first member (first member 10) and a second member (second member 20), wherein the joining surface (joining surface 11) of the first member and the joining surface (joining surface 21) of the second member are overlapped and joined to form the joined member having a stirred section (stirred section 35) that has been stirred and recrystallized by a pressed probe (joining tool 3) and a joined section (joined section 37) formed on the first member and the second member, and the essence of the joining process is that the joined section is formed while the vicinity of the stirred section is cooled.

[0010] Furthermore, in the friction stir welding method of the above-described application example, the welding step may be such that the welding portion is formed while the portion constituting the welding structure (welding structure 1) is cooled when the welding structure is formed by a removal process (removal process step S5) on the welding member. [Brief explanation of the drawing]

[0011] [Figure 1] (A) is an overall diagram showing the schematic configuration of a joint structure 1, which is an example of an embodiment to which the present invention is applied, and (B) is an overall diagram showing the schematic configuration of the first member 10 that constitutes the joint structure 1. [Figure 2] This is a flowchart illustrating the manufacturing method of the jointed structure 1. [Figure 3-1] This diagram illustrates the member formation process in the manufacturing method of the joint structure 1, where (A) is a diagram illustrating the first member 10 and the second member 20 fixed to the joint support jig 50, and (B) is a diagram illustrating the joint guide portion 17 formed on the first member 10 fixed to the joint support jig 50. [Figure 3-2] This diagram illustrates the member formation process in the manufacturing method of the joint structure 1, where (A) is a diagram illustrating the configuration of the joining support jig 50, and (B) is a schematic cross-sectional view of the first member 10 and the second member 20 fixed to the joining support jig 50. [Figure 4] This diagram illustrates the friction stir welding process in the manufacturing method of the joined structure 1, where (A) is a diagram illustrating the process of joining the first member 10 and the second member using a friction stir welding apparatus 3, and (B) is a schematic cross-sectional view of the first member 10 and the second member 20 joined together while fixed to a joining support jig 50. [Figure 5-1] This diagram illustrates the removal process in the manufacturing method of the jointed structure 1, where (A) is a diagram illustrating the jointed member 30 and the removal support jig 70, and (B) is a diagram illustrating the jointed member 30 fixed to the removal support jig 70. [Figure 5-2] This diagram illustrates the removal process in the manufacturing method of the joint structure 1, where (A) is a schematic cross-sectional view of the joint member 30 fixed to the removal support jig 70, and (B) is a diagram illustrating the joint member 30 fixed to the removal support jig 70 during the removal process. [Figure 6] This is a diagram illustrating other embodiments. [Modes for carrying out the invention]

[0012] The embodiments to which the present invention is applied will be described below with reference to the drawings. However, the embodiments of the present invention are not limited to those described below, and various forms can be taken as long as they fall within the technical scope of the present invention.

[0013] <Explanation of the structure of the jointed structure 1> Referring to Figure 1, the configuration of a joint structure 1, which is an example of an embodiment to which the present invention is applied, will be described first. Figure 1(A) is an overall diagram showing the schematic configuration of a joint structure 1, which is an example of an embodiment to which the present invention is applied, and Figure 1(B) is an overall diagram showing the schematic configuration of the first member 10 that constitutes the joint structure 1.

[0014] As shown in Figures 1(A) and 1(B), the joint structure 1 is a hollow structure made of duralumin that will serve as a wing for a flying object, etc. It is formed by machining (removal processing) from a joint member 30 (see Figure 4(B)) into which a first member 10 that forms the dorsal side and a second member 20 (see Figure 3-1(A)) that forms the ventral side are joined. Furthermore, in the first member 10, a first recess 12 that forms the hollow portion of the joint structure 1 is formed on the side of the joint surface 11 that is joined to the joint surface 21 of the second member 20. In addition, the first member 10 has multiple fixing holes 13 into which multiple fixing devices 65 (see Figure 3-1(A)) are fitted to fix the second member 20 so that its position does not shift when it is joined to the second member 20. Multiple holes are formed that penetrate from the joint surface 11 to the opposite side. In addition, the second member 20 has substantially the same configuration as the first member 10, and the second recess 22 and the plurality of fixing holes 23 on the joining surface 21 are formed so as to be symmetrical when the joining surface 21 of the second member 20 is aligned with the joining surface 11 of the first member 10 (see Figure 3-1(A)).

[0015] <Explanation of the manufacturing method for the joined structure 1> Referring to Figure 2, the manufacturing method of the joint structure 1 of this embodiment will now be described. Figure 2 is a flowchart for explaining the manufacturing method of the joint structure 1. As shown in Figure 2, the manufacturing method of the joint structure 1 consists of a member formation step (step S1), a friction stir welding step (step S3), and a removal process (step S5), which are executed in order. First, the member formation step (step S1) is a process of forming a first member 10 (see Figure 3-1(B)) with a first recess 12, a plurality of fixing holes 13, and a joining guide portion 17, and a second member 20 with a second recess 22 and a plurality of fixing holes 23, by machining two plate-shaped members made of duralumin. Next, the friction stir welding step (step S3) is a process of forming a joint member 30 (see Figure 4(B)) by joining the first member 10 and the second member 20 formed in the member formation step by friction stir welding. The removal process in step S5 is a process in which the joint structure 1 is formed by performing machining (removal processing) on ​​the joint member 30 formed in the friction stir welding process.

[0016] <Explanation of the component formation process in Step S1> Referring to Figures 3-1 and 3-2, the member formation process (step S1) in the manufacturing method of the joint structure 1 of this embodiment will now be described. Figure 3-1 is a diagram illustrating the member formation process of step S1 in the manufacturing method of the joint structure 1, where (A) is a diagram illustrating the first member 10 and the second member 20 fixed to the joint support jig 50, and (B) is a diagram illustrating the joint guide portion 17 formed on the first member 10 fixed to the joint support jig 50. Figure 3-2 is a diagram illustrating the member formation process of step S1 in the manufacturing method of the joint structure 1, where (A) is a diagram illustrating the configuration of the joint support jig 50, and (B) is a schematic cross-sectional view of the first member 10 and the second member 20 fixed to the joint support jig 50.

[0017] As shown in Fig. 3-1(A), in the member forming step of step S1, the second member 20 is placed on the joining support jig 50 such that the surface on the opposite side of the joining surface 21 of the second member 20 is aligned with the placement surface 51 of the joining support jig 50 (see Fig. 3-2(A)). In this state, the second member 20 placed on the joining support jig 50 is fixed by a fixture (not shown). Then, the first member 10 is placed on the second member 20 such that the joining surface 11 of the first member 10 is aligned with the joining surface 21 of the second member 20 fixed to the joining support jig 50. In this state, the first member 10 placed on the second member 20 is fixed by a plurality of fixtures 65. Although detailed description is omitted, before the first member 10 and the second member 20 are fixed to the joining support jig 50 as described above, by machining such as milling on two plate-like members made of duralumin, a first member 10 having a first recess 12 and a plurality of fixing holes 13 formed therein, and a second member 20 having a second recess 22 and a plurality of fixing holes 23 formed therein are formed. This step is also assumed to be included in the member forming step of step S1.

[0018] As shown in Fig. 3-1(B), next, in the member forming step of step S1, a joining guide portion 17, which is a concave groove serving as a guide when moving the joining tool 3 of the friction stir welding device along it in the friction stir welding step of step S3, is formed by machining such as milling on the surface on the opposite side of the joining surface 11 of the first member 10 fixed to the joining support jig 50 and the second member 20. The joining guide portion 17 is composed of a first guide portion 18a having a shape along the outer edge of the joining structure 1 formed by the removal processing step of step S5 described later, and a second guide portion 18b provided at a location corresponding to the outside of the outer edge of the joining structure 1. The first guide portion 18a and the second guide portion 18b may be grooves with a width into which the shoulder of the joining tool 3 fits, and may have grooves of various widths according to the size of the shoulder of the joining tool used in the friction stir welding step.

[0019] Referring to Fig. 3-2(A), the joining support jig 50 used in the friction stir joining process of step S3 will be described here. The joining support jig 50 has a flow path portion 55, which is a concave groove for flowing a coolant (cutting fluid), formed on the placement surface 51 on which the second member 20 is placed. Further, the flow path portion 55 is formed so as to overlap a portion surrounded by the joining guide portion 17 formed so as to surround the inside of the first member 10 in the stacking direction of the joining support jig 50, the first member 10, and the second member 20. Although not shown, a supply port for supplying the coolant to the flow path portion 55 and a discharge port for discharging the coolant from the flow path portion 55 are formed in the joining support jig 50, and a coolant device for supplying and discharging the coolant to and from the joining support jig 50 is provided.

[0020] As shown in Fig. 3-2(B), and when the first member 10 and the second member 20 are fixed to the joining support jig 50 in the member forming process of step S1, the first recess 12 and the second recess 22 are combined to form the hollow portion of the joined member 30 (joined structure 1), and in the direction from the surface on the opposite side of the joining surface 11 of the fixed first member 10 toward the joining surface 11, the joining guide portion 17 and the flow path portion 55 are arranged so as not to overlap. That is, the first guide portion 18a of the joining guide portion 17 is formed to have substantially the same shape as the shape of the flow path portion 55 and to be slightly smaller.

[0021] <Description of the friction stir joining process of step S3> Referring to Fig. 4, next, the friction stir joining process (step S3) in the manufacturing method of the joined structure 1 of the present embodiment will be described. Fig. 4 is a diagram for explaining the friction stir joining process of step S3 in the manufacturing method of the joined structure 1, (A) is a diagram for explaining the process of joining the first member 10 and the second member with the friction stir joining device 3, and (B) is a schematic cross-sectional view of the first member 10 and the second member 20 joined in a state fixed to the joining support jig 50.

[0022] As shown in Figure 4(A), in the friction stir welding step S3, the probe of the joining tool 3 is pushed in from the second guide portion 18b of the joining guide portion 17 formed on the first member 10, and the shoulder of the joining tool 3 is moved along the first guide portion 18a of the joining guide portion 17, thereby forming a joined member 30 in which the first member 10 and the second member 20 are joined. The probe of the joining tool 3 is pushed in from the opposite side of the joining surface 11 of the first member 10 until it passes the joining surface 21 of the second member 20, and then moved along the joining guide portion 17. In addition, in the friction stir welding step S3, friction stir welding is performed by moving the pushed probe while coolant is flowing through the flow path 55 of the joining support jig 50. Then, the probe of the joining tool 3 is moved around the first guide portion 18a of the joining guide portion 17 to join the first member 10 and the second member 20. With the probe still pressed in, the joining tool 3 is moved to the second guide portion 18b, and the probe is withdrawn at the second guide portion 18b to complete the friction stir welding. In step S3, the friction stir welding process is started by pushing the probe of the joining tool 3 into the second guide portion 18b of the joining guide portion 17. However, the probe of the joining tool 3 may also be pushed in from near the second guide portion 18b of the first guide portion 18a of the joining guide portion 17, moved around the first guide portion 18a, and then the friction stir welding is completed by withdrawing the moved probe at the second guide portion 18b.

[0023] As shown in Figure 4(B), in the friction stir welding process of step S3, when the first member 10 and the second member 20 are joined while fixed to the joining support jig 50, a stirred portion 35, which is the part that has been stirred and recrystallized by the probe of the joining tool 3, is formed in the thickness direction of the first member 10 and the second member 20 (the direction along the trajectory 4 through which the central axis of the pushed probe passed) to a predetermined depth corresponding to the position reached by the pushed probe. In addition, in the portion of the stirred portion 35 where the joining surface 11 of the first member 10 and the joining surface 21 of the second member 20 were joined, a joint portion 37 is formed where the first member 10 and the second member 20 are joined. Note that in the friction stir welding process of step S3, the flow channel portion 55 of the joining support jig 50 is provided so as to be near the joint portion 37 and the stirred portion 35. Furthermore, the flow channel section 55 is located in a position that overlaps with the portion of the joining structure 1 that constitutes the joining structure 1 when the joining structure 1 is formed by the removal process of step S5 on the joining member 30 (see Figure 5-2(A)) in the direction in which the probe of the joining tool 3 is pushed in, and is located in a position that does not overlap with the joining section 37 and the stirring section 35.

[0024] <Explanation of the removal process in Step S5> Referring to Figures 5-1 and 5-2, the removal process (step S5) in the manufacturing method of the jointed structure 1 of this embodiment will be described. Figure 5-1 is a diagram illustrating the removal process of step S5 in the manufacturing method of the jointed structure 1, where (A) is a diagram illustrating the jointing member 30 and the removal support jig 70, and (B) is a diagram illustrating the jointing member 30 fixed to the removal support jig 70. Figure 5-2 is a diagram illustrating the removal process of step S5 in the manufacturing method of the jointed structure 1, where (A) is a schematic cross-sectional view of the jointing member 30 fixed to the removal support jig 70, and (B) is a diagram illustrating the jointing member 30 fixed to the removal support jig 70 during the removal process.

[0025] As shown in Figures 5-1(A) and (B), first, in the removal process of step S5, the joining member 30 is fixed at both ends to the removal support jig 70 by a plurality of fasteners 75. At this time, the joining member 30 is fixed so that the joining guide portion 17 (first guide portion 18a) is not covered by the removal support jig 70 and the plurality of fasteners 75. Furthermore, the joining member 30 fixed to the removal support jig 70 is fixed so that the joining guide portion 17 does not overlap with the removal support jig 70 on the surface opposite to the surface on which the joining guide portion 17 is formed. Then, by rotating the removal support jig 70, the joining member 30 rotates, and a cutting tool (not shown) can be applied to the desired position on the surface of the joining member 30 on which the joining guide portion 17 is formed and on the opposite surface, and the removal process can be performed. Furthermore, in the joining member 30, when the friction stir welding process of step S3 is completed, the probe of the joining tool 3 is withdrawn from the second guide portion 18b of the joining guide portion 17, and a hole is formed in the second guide portion 18b as a trace of where the probe was withdrawn.

[0026] As shown in Figure 5-2(A), in the removal process of step S5, the joint structure 1 is formed by removing material from the joint member 30 fixed to the removal support jig 70 by applying a cutting tool (not shown) along the cutting surface 8. At this time, since the cutting surface 8 has a thickness in a direction perpendicular to the joint surface 11 and the joint surface 21, the removal process is performed so that the vicinity of the joint portion 37, which is a stirring portion 35 on at least one side of the first member 10 and the second member 20 of the joint member 30 and is formed in a direction perpendicular to the joint surface 11 of the first member 10 or the joint surface 21 of the second member 20, is exposed. In particular, the removal process is performed so that the vicinity of the joint portion 37, which is a stirring portion 35 formed across the first member 10 and the second member 20 of the joint member 30 and is formed in a direction perpendicular to the joint surface 11 of the first member 10 or the joint surface 21 of the second member 20, is exposed. Furthermore, in the removal process of step S5, the joint portion 37 of the joining member 30 is processed so that the trajectory 4 of the central axis of the probe of the joining tool 3 that passed through in the friction stir welding process of step S3 is included in the portion that is not removed (the portion that constitutes the joining structure 1), and a portion of the trajectory 4 of the central axis of the probe of the joining tool 3 that passed through in the friction stir welding process of step S3 (the trajectory 4 located in the stirring portion 35 above the cutting surface 8) is included in the portion that is removed (the portion that does not constitute the joining structure 1) in the stirring section 35 formed on the first member 10 side of the joining member 30. Note that since the first recess 12 and the second recess 22 are formed on the inside of the cutting surface 8, which constitutes the joining structure 1, the joining structure 1 becomes a hollow structure.

[0027] As shown in Figure 5-2(B), and during the removal process in step S5, the joining member 30 is processed so that the portion that is not removed (the portion that constitutes the joining structure 1) and the portion that is removed (the portion that does not constitute the joining structure 1) are clearly distinguishable. At this time, the second guide portion 18b of the joining member 30 is on the side that is removed in the removal process in step S5, so the joining structure 1 can be formed so that no holes remain, which are traces of where the probe of the joining tool 3 was pulled out. Furthermore, since the joint structure 1 is formed in the removal process of step S5, the joint structure 1 may be formed such that the intersection point between the joint surface 11 and the trajectory 4 of the central axis of the probe of the joining tool 3 that passed through the friction stir welding process of step S3 (a straight line extending from the widthwise center of the first guide portion 18a in the lamination direction of the first member 10 and the second member 20) of the joint guide portion 17 of the first member 10 is included in the portion that is not removed (the portion that constitutes the joint structure 1), and the outer edge of the portion that is not removed (the portion that constitutes the joint structure 1) is included in the region enclosed by the straight line that extends the two sides of the first guide portion 18a in the lamination direction of the first member 10 and the second member 20.

[0028] <Features of the manufacturing method of the jointed structure 1 of this embodiment> According to the manufacturing method of the joined structure 1 of the above embodiment, the manufacturing method of the joined structure 1 comprising a joined member 30 formed by joining a first member 10 and a second member 20 by friction stir welding, is characterized by: a friction stir welding step S3 in which the joining surface 11 of the first member 10 and the joining surface 21 of the second member 20 are superimposed and the probe of the joining tool 3 is pressed in from the side of the first member 10 opposite to the joining surface 11, thereby forming a joined member 30 having a stirred portion 35 that has been stirred and recrystallized by the probe and a joined portion 37 formed on the first member 10 and the second member 20; and a removal process step S5 in which the joined member 30 formed in the friction stir welding step S3 is removed so that the vicinity of the joined portion 37, which is a stirred portion 35 formed on at least one side of the first member 10 side and the second member 20 side and is formed in a direction perpendicular to the joining surfaces 11, 21 of the first member 10 or the second member 20, is exposed.

[0029] In this method of manufacturing the joined structure 1, the joint portion of the joined structure 1, which would conventionally be the connection between the first member 10 and the second member 20, can be made into a joint portion 37 which is part of the stirred portion 35 formed by the stirring and recrystallization of the first member 10 and the second member 20 by friction stir welding. In particular, in the structure of the joined structure 1, a thickness is formed in the joint portion in a direction perpendicular to the joining surface 11 of the first member 10 and the joining surface 21 of the second member 20. In this method of manufacturing the joined structure 1, in the removal process of step S5, the vicinity of the joint portion 37, which is the part formed in a direction perpendicular to the joining surface 11 of the first member 10 or the joining surface 21 of the second member 20, is removed so that it is exposed. As a result, a sufficient area of ​​the stirred portion 35 formed by the stirring and recrystallization of the first member 10 and the second member 20 by friction stir welding can be made into the joint portion. Therefore, with this method of manufacturing the joined structure 1, it is possible to manufacture a joint portion of two members with significantly greater strength than conventional methods.

[0030] Furthermore, according to the manufacturing method of the joined structure 1 of the above embodiment, in the removal process of step S5, the joint member 30 can be removed in such a way that the vicinity of the joint portion 37, which is a stirring portion 35 formed on the first member 10 side and the second member 20 side and is formed in a direction perpendicular to the joining surfaces 11, 21 of the first member 10 or the second member 20, is exposed. With such a manufacturing method of the joined structure 1, a sufficient area of ​​the stirring portion 35, which is formed by stirring and recrystallizing the first member 10 and the second member 20 by friction stir welding, can be made into the joint portion of the joined structure 1, so that a joint portion of the two members can be manufactured with more than sufficient strength than conventional methods.

[0031] Furthermore, according to the manufacturing method of the joint structure 1 of the above embodiment, in the removal process of step S5, the joint member 30 can be removed such that the trajectory 4 of the central axis of the probe that passed through the friction stir welding at the joint portion 37 is included in the portion that is not removed. With such a manufacturing method of the joint structure 1, even the stirring portion 35 formed in the region perpendicular to the trajectory 4 of the central axis of the probe can be made into a sufficient area of ​​the joint portion of the joint structure 1, so that a joint portion of the two members can be manufactured with significantly greater strength than conventional methods.

[0032] Furthermore, according to the manufacturing method of the joint structure 1 of the above embodiment, in the removal process of step S5, the joint member 30 can be removed such that a portion of the trajectory 4 of the central axis of the probe that passed through the friction stir welding in the stirring section 35 formed in the first member 10 is included in the portion to be removed. With such a manufacturing method of the joint structure 1, a sufficient area of ​​the stirring section 35 can be made into the joint portion of the joint structure 1, and the shape of the joint portion can be formed into a desired shape. Therefore, it is possible to manufacture a joint portion of two members with a desired shape while maintaining sufficient strength compared to conventional methods.

[0033] Furthermore, according to the manufacturing method of the joined structure 1 of the above embodiment, the joined member 30 is provided with a second guide portion 18b, which is the endpoint of the moving probe, in the portion to be removed in the removal process of step S5, and the friction stir welding process of step S3 can be completed by withdrawing the probe that has been moved to the second guide portion 18b after the first member 10 and the second member 20 have been joined. With such a manufacturing method of the joined structure 1, since no withdrawal hole is formed in the joined structure 1 when the probe is withdrawn, a joined structure of a desired shape can be manufactured.

[0034] <Features of the joining support jig 50 of this embodiment> The joining support jig 50 of the above-described embodiment is a joining support jig 50 in the friction stir welding step S3 that supports at least one of the first member 10 and the second member 20 when a joined member 30 is formed by joining the first member 10 and the second member 20 by friction stir welding, and is characterized by comprising a flow path 55 through which coolant flows to cool the vicinity of the joint 37 formed in the first member 10 and the second member 20.

[0035] In such a joining support jig 50, during the friction stir welding process of step S3, friction stir welding can be performed while cooling the vicinity of the joint 37 formed on the first member 10 and the second member 20 (particularly the portion constituting the joined structure 1 near the joint 37) with the coolant flowing through the flow channel 55. Therefore, with such a joining support jig 50, deformation due to temperature rise near the joint of the two members to be joined can be suppressed more effectively than in conventional methods during the execution of friction stir welding.

[0036] Furthermore, according to the joining support jig 50 of the above-described embodiment, at least a portion of the flow channel 55 can be positioned so as to overlap with the portion constituting the joining structure 1 when the joining structure 1 is formed by the removal process of step S5 on the joining member 30, in the direction in which the probe of the joining tool 3 is pushed in. With such a joining support jig 50, during the execution of friction stir welding, the conduction of heat from the joining member 30 to the portion constituting the joining structure 1 can be suppressed, thereby suppressing deformation due to temperature rise in the joining member 30 (joining structure 1) more than in the conventional method.

[0037] Furthermore, according to the joining support jig 50 of the above-described embodiment, the flow channel 55 can be positioned so as not to overlap with the joining portion 37 in the direction in which the probe is pushed in. With such a joining support jig 50, in the friction stir welding process of step S3, friction stir welding can be performed while cooling the portion constituting the joining structure 1 near the joining portion 37, without cooling in a way that would hinder the stirring of the members during friction stir welding at the joining portion 37. Therefore, with such a joining support jig 50, deformation due to temperature rise in the joining members (joint structure) can be suppressed more than in the conventional method without hindering the friction stir welding at the joining portion of the two members during the execution of friction stir welding.

[0038] Furthermore, according to the joining support jig 50 of the above-described embodiment, the flow channel 55 is formed by stirring with the probe and cools the vicinity of the stirring section 35, which includes part of the joining section 37, and at least a portion of it can be positioned so as not to overlap with the stirring section 35 in the direction in which the probe is pushed in. With such a joining support jig 50, in the friction stir welding process of step S3, friction stir welding can be performed while cooling the part constituting the joining structure 1 near the stirring section 35, without cooling in a way that would hinder the stirring of the members in the friction stir welding in the stirring section 35. Therefore, with such a joining support jig 50, deformation due to temperature rise in the joining members (joining structure) can be suppressed more than in the conventional method without hindering the friction stir welding in the part where the two members are being stirred during the execution of friction stir welding.

[0039] <Features of the friction stir welding process in step S3 of this embodiment> According to the friction stir welding step S3 of the above-described embodiment, a friction stir welding method is performed to form a joined member 30 by joining a first member 10 and a second member 20, wherein the joining surface 11 of the first member 10 and the joining surface 21 of the second member 20 are overlapped and joined, thereby forming a joined member 30 having a stirred portion 35 that has been stirred and recrystallized by the probe of the pressed joining tool 3, and a joined portion 37 formed on the first member 10 and the second member 20, and the friction stir welding step S3 is characterized in that the joined portion 37 is formed while the vicinity of the stirred portion 35 is cooled.

[0040] In the friction stir welding process of step S3, the friction stir welding is performed while the vicinity of the stirring section 35 formed in the first member 10 and the second member 20 (particularly the portion constituting the joined structure 1 near the joint 37) is cooled. Therefore, with the friction stir welding process of step S3, deformation due to temperature rise in the vicinity of the portion stirred by the friction stir welding of the two members can be suppressed more effectively than in conventional methods.

[0041] Furthermore, according to the friction stir welding process of step S3 in the above-described embodiment, when the joint structure 1 is formed by the removal process of step S5 on the joining member 30, the portion constituting the joint structure 1 is cooled while the joint portion 37 is formed. With such a friction stir welding process of step S3, heat conduction to the portion constituting the joint structure of the joining member is suppressed during the execution of friction stir welding, thereby suppressing deformation due to temperature rise in the joining member (joint structure) more effectively than in conventional methods.

[0042] <Other Embodiments> In the above-described embodiment, the joint structure 1 (first member 10, second member 20) is assumed to be made of duralumin, but any material that can be joined by friction stir welding is acceptable, and various types of duralumin can be used. For example, it may be made of duralumin A7075, duralumin A2024, or duralumin A2017. Furthermore, although the joint structure 1 is assumed to be a hollow structure that forms the wing of a flying object, it may be any structure in which multiple members are joined by friction stir welding, and the materials constituting the multiple members and the joint structure may also be made of various metals or resins that can be joined by friction stir welding.

[0043] In the above-described embodiment, the first member 10 and the second member 20 were both composed of plate-shaped members of substantially the same shape, but a jointed member may be formed by joining two members of different shapes. Here, with reference to Figures 6(A) and (B), a specific example of a jointed member formed by joining two members of different shapes will be described. Figures 6(A) and (B) are diagrams for illustrating a jointed member 130 formed from a first member 110 and a second member 120 using a spigot joint, where (A) is a diagram for illustrating the first member 110 and the second member 120 in the member formation process, and (B) is a diagram for illustrating the removal process for the jointed member 130 formed in the friction stir welding process. Note that in Figures 6(A) and (B), the illustration of joining support jigs and removal support jigs used in the manufacturing process of the jointed structure is omitted.

[0044] As shown in Figure 6(A), the first member 110 is a plate-shaped member made of duralumin, and the second member 120 is a plate-shaped member made of duralumin with a recess formed therein in which the first member 110 fits. Furthermore, in the member formation process, a recess 220 that forms the hollow part of the joint structure is formed on the joint surface 121a which is the bottom surface of the recess in the second member 120 by machining such as milling. Then, the first member 110 is fitted into the second member 120 such that the joint surface 111a of the first member 110 aligns with the joint surface 121a of the second member 120, and the joint surface 111b of the first member 110 aligns with the joint surface 121b of the second member 120. Then, in the member formation process, a joint guide portion 117, which is a concave groove that serves as a guide for moving the joining tool of the friction stir device along it during the friction stir welding process, is formed at the location where the joining surface 111b of the first member 110 and the joining surface 121b of the second member 120 meet by machining such as milling. The joint guide portion 117 is composed of a first guide portion and a second guide portion as in the embodiment described above, and the first guide portion and the second guide portion only need to be grooves with a width that allows the shoulder of the joining tool 3 to fit into, and the grooves may be of various widths depending on the size of the shoulder of the joining tool used in the friction stir welding process.

[0045] As shown in Figure 6(B), in the removal process for the joined member 130 formed by joining the first member 110 and the second member 120 in the friction stir welding process, the joined structure is formed by performing a removal process on the joined member 30 fixed to a removal support jig, such as applying a cutting tool (not shown) along the cutting surface 108. At this time, since the cutting surface 108 has a thickness in a direction perpendicular to each of the joining surfaces 111a, 111b, 121a, and 121b, the removal process is performed so that the vicinity of the joining portions 137a and 137b, which are the stirring portions 135 formed across the first member 110 and the second member 120 in the joined member 130 and are formed in a direction perpendicular to each of the joining surfaces 111a and 111b of the first member 110 and 121a and 121b of the second member 120, is exposed. In other words, even a manufacturing method for a joint structure using such an interlocking joint has substantially the same characteristics as the manufacturing method of the embodiment described above, and achieves the same effects.

[0046] In the above-described embodiment, the flow channel portion 55 of the joining support jig 50 was located in a position that overlapped with the portion constituting the joining structure 1 in the direction in which the probe of the joining tool 3 is pushed in, and did not overlap with the joining portion 37 and the stirring portion 35. However, the position of the flow channel portion is not limited to this and may be located in other positions. Now, with reference to Figure 6(C), a specific example of a joining support jig with a different configuration from the joining support jig 50 in the above-described embodiment will be described. Figure 6(C) is a diagram illustrating the configuration of a joining support jig 150 as another embodiment.

[0047] As shown in Figure 6(C), the flow path portion 155 of the joining support jig 150 is provided so as to be near the joining portion 37 and the stirring portion 35. Furthermore, at least a portion of the flow path portion 155 is provided so as to overlap with the portion that constitutes the joined structure 1 when the joined structure 1 is formed by the removal process on the joining member 30, in the direction in which the probe of the joining tool 3 is pushed in. The joining support jig 150 is also provided with a coolant supply port, an outlet port and a coolant device, similar to the joining support jig 50 described above, although it is not shown. Even with such a joining support jig 150, similar to the joining support jig 50 of the embodiment described above, deformation due to temperature rise in the joining member 30 (joint structure 1) during friction stir welding can be suppressed more than in the conventional method.

[0048] In the above-described embodiment, the joining support jig 50 cooled the joining members during the friction stir welding process by a flow channel 55 through which coolant flowed. However, the cooling device and cooling method are not limited to this, and any device and method that can cool the joining members may be used. For example, the joining support jig may be provided with a cooling device utilizing a Peltier element. Specifically, a Peltier element may be arranged in the same shape as the flow channel 55 in the joining support jig 50 of the above-described embodiment, and the supported joining members may be cooled by supplying a DC current from a connected power source. Even such a joining support jig has substantially the same features as the joining support jig of the above-described embodiment and produces the same effects.

[0049] The present invention has been described above based on embodiments and modifications. However, the embodiments of the invention described above are for the purpose of facilitating understanding of the present invention and do not limit it. The present invention can be modified and improved without departing from its spirit and claims, and the present invention includes equivalents thereof. [Explanation of Symbols]

[0050] 1...Joining structure, 3...Joining tool (probe), 4...Trajectory, 10...First member, 11, 21...Joining surface, 18b...Second guide section, 20...Second member, 30...Joining member, 35...Agitation section, 37...Joining section, 50...Joining support jig, 55...Flow path section (cooling section).

Claims

1. A jig for friction stir welding is used to support at least one of the first member and the second member when a jointed member is formed by joining a first member and a second member by friction stir welding, A cooling unit that cools the vicinity of the joint formed between the first member and the second member, A jig for friction stir welding, characterized by comprising the following features.

2. A jig for friction stir welding according to claim 1, The jig for friction stir welding is characterized in that at least a portion of the cooling section is provided at a position that overlaps with a portion of the joining structure when the joining structure is formed by a removal process on the joining member, in the direction in which the probe is pushed in.

3. A jig for friction stir welding according to claim 2, The jig for friction stir welding is characterized in that the cooling section is provided at a position that does not overlap with the joint in the direction in which the probe is pushed in.

4. A jig for friction stir welding according to claim 2, The jig for friction stir welding is characterized in that the cooling section is formed by stirring with the probe and cools the vicinity of the stirring section which includes the joint, and at least a portion of the cooling section is provided in a position that does not overlap with the stirring section in the direction in which the probe is pushed in.

5. A jig for friction stir welding according to claim 2, The jig for friction stir welding is characterized in that the cooling section has a passage through which coolant flows near the joint.

6. A friction stir welding method for joining a first member and a second member to form a joined member, A joining process is performed in which a joined member is formed having a stirred portion that has been stirred and recrystallized by a pressed probe, and a joined portion formed between the first member and the second member, by overlapping and joining the joining surface of the first member and the joining surface of the second member. The joining step is a friction stir joining method characterized in that the joint is formed while the vicinity of the stirring section is cooled.

7. A friction stir welding method according to claim 6, The joining step is a friction stir joining method characterized in that the joining portion is formed while the portion constituting the joining structure is cooled when the joining structure is formed by a removal process on the joining member.

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