Jig for friction stir joining

Abstract

To provide a jig for friction stir joining inserted into inside of a hollow member in friction stir joining which is easily inserted and hardly causes deformation of the hollow member at the time of joining.SOLUTION: A jig can be inserted into inside of a hollow member to join the hollow member by friction stir joining. The jig can be variable in size in a pressure-reception direction where the hollow member is pressed by a tool of the friction stir joining.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a jig used when performing friction stir welding. [Background technology]

[0002] It is known that when joining hollow members by friction stir welding, a jig such as that shown in Patent Document 1 is used. This type of jig is inserted inside the hollow member, but if there is a gap between the jig and the inner surface of the hollow member, the hollow member is pushed by the friction stir welding tool and deforms until it comes into contact with the jig.

[0003] Patent Documents 2 and 3 disclose so-called cores, but neither of them is used for friction stir welding. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2000-317655 A [Patent Document 2] Japanese Patent Application Publication No. 07-148548 [Patent Document 3] Japanese Patent Application Publication No. 01-080509 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure has an objective of providing a friction stir welding jig that is inserted into the inside of a hollow member during friction stir welding of the hollow member, which is easy to insert and does not easily cause deformation of the hollow member during welding. [Means for solving the problem]

[0006] The present application discloses a jig that can be inserted inside a hollow member to join the hollow member by friction stir welding, and that has a dimension that can be changed in the pressure direction, which is the direction in which the hollow member is pressed by a friction stir welding tool.

[0007] The jig may have a cam member, and the dimension in the pressure-receiving direction may be changed by rotation of the cam member.

[0008] The jig may be configured to include a plurality of members having inclined surfaces, and by pressing the plurality of members against each other, the plurality of members may slide against each other on the inclined surfaces, thereby changing the dimensions in the pressure-receiving direction.

[0009] The jig may be configured to include an elastic body, and the dimension in the pressure-receiving direction may be changed by pressing the elastic body.

[0010] The jig may have a member formed by connecting a number of links that can rotate relative to one another, and may be configured so that application of force in the direction in which the member extends causes the links to rotate relative to one another, thereby changing the dimension in the pressure-receiving direction. In this case, the links may be provided with protrusions on every other link, and the protrusions may be configured to protrude in a direction perpendicular to the direction in which the member extends. Effect of the Invention

[0011] According to the present disclosure, when the jig is inserted into and removed from the hollow member, a large gap can be created between the jig and the inner surface of the hollow member, while when joining by friction stir welding (pressing and moving the tool), the jig can be brought into contact with the inner surface of the hollow member while suppressing deformation of the hollow member, resulting in a friction stir welding jig that is easy to insert and is less likely to cause deformation of the hollow member during joining. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram for explaining friction stir welding and a jig. [Diagram 2]FIG. 2 is a diagram illustrating the jig 10 according to the first embodiment. [Diagram 3] FIG. 3 is a diagram illustrating a jig 20 according to the second embodiment. [Figure 4] FIG. 4 is a diagram illustrating a jig 30 according to the third embodiment. [Diagram 5] FIG. 5 is a diagram illustrating a jig 40 according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 1. Friction stir welding The friction stir welding in this disclosure is as known. That is, as shown in Fig. 1, a cylindrical tool 1 has a protrusion called a probe 1a on its tip surface, and the probe 1a is inserted to a predetermined depth into the butt joint (unjoined portion) of the materials to be joined 2 while rotating (R), and the materials are joined by moving (T) the tool 1 along the butt joint. The rotation of the tool 1 heats up the materials to be joined 2 around where the tool 1 is inserted due to frictional heat with the tool 1 and processing heat, softening the parts of the materials to be joined 2 and causing plastic flow around the joint, mixing and integrating them, thereby joining the materials.

[0014] In particular, the present disclosure relates to a jig used in performing friction stir welding on a butted portion when the materials to be joined 2 are hollow members 2 having a square cylindrical (tubular) shape as shown in Fig. 1. The jig is inserted inside the hollow member 2 and supports the hollow member 2 from the inside. The jigs according to each embodiment will be described below.

[0015] 2. Jig The jig will be described below. The jigs of the present disclosure have in common that, when inserted inside the hollow member 2, they can change their dimensions in the direction connecting the surface of the hollow member 2 having the butted portion and the surface facing this (this is the direction in which the tool 1 presses the hollow member 2, and since the jig receives this pressing force, this is referred to as the "pressure-receiving direction"). According to the jig of the present disclosure, the dimension in the pressure direction can be reduced when inserting the jig before joining and when removing the jig after joining, thereby making it easier to insert and remove the jig into the hollow member 2. On the other hand, after the jig is inserted inside the hollow member 2, the dimension of the jig in the pressure receiving direction is changed so as to become larger, and the jig comes into contact with the inner surface of the hollow member 2, or the gap between the jig and the inner surface of the hollow member 2 is reduced. As a result, even if the hollow member 2 receives a pressing force from the tool 1 during joining, the jig receives this force and supports the hollow member 2 before the hollow member 2 is significantly deformed, thereby suppressing deformation of the hollow member 2. The jig will be described below in more specific form.

[0016] 2.1.Form 1 Fig. 2 shows an explanatory diagram of the jig 10 according to the first embodiment. Fig. 2(a) is a perspective view showing a part of the jig 10, Fig. 2(b) is a view of the jig 10 as seen from the side in which the direction in which the jig 10 is inserted into the hollow member 2 is the direction toward the front / back of the page, showing a state in which the dimension of the jig 10 in the pressure-receiving direction is reduced, and Fig. 2(c) shows a state in which the jig 10 has been deformed so that the dimension of the jig 10 in the pressure-receiving direction is increased from the same perspective as Fig. 2(b). As can be seen from these figures, the jig 10 has a first pressure-receiving member 11, a second pressure-receiving member 12, and a cam member 13.

[0017] The first pressure-receiving member 11 and the second pressure-receiving member 12 are plate-shaped members, and the two pressure-receiving members 11, 12 are arranged side by side in the pressure-receiving direction so that the plate surfaces have opposing faces 11a, 12a that face each other. Of the faces of the two pressure-receiving members 11, 12, the faces opposite the opposing faces 11a, 12a are oriented so as to face the inner surface of the hollow member 2, respectively, and function as pressure-receiving surfaces 11b, 12b. One of the inner surfaces of the hollow member 2 (in this embodiment, the face of the hollow member 2 that faces the pressure-receiving surface 11b) is provided with a butt portion that is joined by friction stir welding. In this embodiment, grooves 11c, 12c are provided on the opposing surfaces 11a, 12a of the first pressure-receiving member 11 and the second pressure-receiving member 12, and a cam member 13 is disposed in these grooves. In addition, it is preferable that the first pressure-receiving member 11 and the second pressure-receiving member 12 are biased by a biasing member such as a spring (not shown) so that they attract each other in the pressure-receiving direction. This makes it possible for the deformation to be smooth when the size in the pressure-receiving direction is reduced. The material of the first pressure-receiving member 11 and the second pressure-receiving member 12 is not particularly limited, but examples thereof include metal, resin, etc. Examples of metal include alloys such as stainless steel, and examples of resin include engineering plastics.

[0018] As can be seen from a comparison of Figures 2(b) and 2(c), the cam member 13 is a member whose distance in the pressure-receiving direction changes as it rotates. In this embodiment, the cam member 13 is rod-shaped with an elliptical cross section, and an axial member (not shown) is connected to the axial line of the cam member 13, so that the cam member 13 can rotate about the axial line as the axial member rotates. The specific shape of the cam member 13 is not limited to this as long as the distance in the pressure direction can be changed by its rotation, and multiple short block-shaped cam members, rather than being rod-shaped, may be arranged so that they are connected at a predetermined interval along an axis not shown.

[0019] Such a cam member 13 is disposed between the opposing surface 11a of the first pressure receiving member 11 and the opposing surface 12a of the second pressure receiving member 12, and in this embodiment, is disposed so as to span the inside of the grooves 11c, 12c. As a result, by rotating the cam member 13 about its axis, it is possible to repeatedly switch between a posture in which the dimension in the pressure receiving direction is smaller as shown in Fig. 2(b) and a posture in which the dimension in the pressure receiving direction is larger as shown in Fig. 2(c).

[0020] 2.2.Form 2 Fig. 3 shows an explanatory diagram of the jig 20 according to the second embodiment. Fig. 3(a) is a cross-sectional view along the extension direction of the jig 20, showing a state in which the dimension in the pressure-receiving direction is reduced, Fig. 3(b) is a perspective view of one pressure-receiving member 23 provided in the jig 20, and Fig. 3(c) shows a state in which the jig 20 has been deformed so that the dimension in the pressure-receiving direction is increased from the same perspective as Fig. 3(a). Here, the "extension direction" is the direction in which the jig 20 is inserted into the hollow member 2, as shown by the arrows in Figs. 1 and 3. Note that some of the repeated symbols have been omitted in Fig. 3 for ease of viewing. As can be seen from these figures, the jig 20 has a bolt 21, a nut 22, and a plurality of pressure-receiving members 23.

[0021] The bolt 21 is a known bolt, but in this embodiment, the bolt 21 has a head 21a and a shaft portion 21b on which a spiral groove is formed, and the shaft portion 21b extends long in the extension direction. The nut 22 is screwed onto the shaft portion 21 b of the bolt 21 .

[0022] In this embodiment, the pressure-receiving member 23 is block-shaped, and is a columnar member having a trapezoidal cross section as can be seen in Fig. 3(b). The surface of the pressure-receiving member 23 formed by the long bottom base of the trapezoid serves as the pressure-receiving surface 23a, which comes into contact with or approaches the inner surface of the hollow member 2 (the surface having the abutting portion) and supports the hollow member 2. In addition, a hole 23c is provided in the inclined surface 23b formed by the legs of the trapezoid of the pressure-receiving member 23 so as to penetrate between the two inclined surfaces 23b. This hole 23c is a so-called elongated hole, and has a hole shape that is long in the pressure-receiving direction. The size of the hole 23c is set to a size that allows the shaft portion 21b of the bolt 21 to pass through, but does not allow the head portion 21a and the nut 22 of the bolt 21 to enter. The inclination angle of the inclined surface 23b is not particularly limited, and it is only required that the pressure-receiving member 23 can move in the pressure-receiving direction, as will be described next.

[0023] In the jig 20, a nut 22 is screwed onto the shaft portion 21b of the bolt 21, and multiple pressure-receiving members 23 are arranged between the head portion 21a of the bolt 21 and the nut 22. The multiple pressure-receiving members 23 are arranged side by side along the direction in which the shaft portion 21b of the bolt 21 extends by having the shaft portion 21b pass through the hole 23c. At this time, the adjacent pressure-receiving members 23 are arranged so that the inclined surfaces 23b can overlap with each other. Therefore, the pressure-receiving surfaces 23a of the adjacent pressure-receiving members 23 are alternately arranged so that they are on opposite sides in the pressure-receiving direction.

[0024] Such a fixture 20 operates as follows. As shown in Figure 3(a), in a posture in which the dimension in the pressure-receiving direction is small, the head 21a of the bolt 21 and the nut 22 are separated by a predetermined distance, and at this time, the inclined surfaces 23b of adjacent pressure-receiving members 23 among the multiple pressure-receiving members 23 are separated from each other, or even if they are in contact, they do not press against each other strongly. Next, as shown in Fig. 3(c), the nut 22 and the head 21a of the bolt 21 are rotated relatively in the opposite direction to reduce the distance between them. As a result, the pressure-receiving member 23 arranged between the nut 22 and the head 21a of the bolt 21 is pressed in the axial direction of the shaft portion 21b, so that the adjacent inclined surfaces 23b overlap and further press against each other. Then, the inclined surfaces 23b act as wedges, and the pressure-receiving surfaces 23a of each pressure-receiving member 23 move so as to protrude in the pressure-receiving direction. As a result, the dimension of the jig 20 in the pressure-receiving direction increases, and the pressure-receiving surfaces 23a come into contact with or approach the inner surface (surface having the butt portion) of the hollow member 2, so that the hollow member 2 can be supported from the inner surface during friction stir welding. After joining, the distance between the head 21a of the bolt 21 and the nut 22 is increased in the opposite manner to the above, thereby returning to the state shown in FIG. 3(a). In this manner, the jig 20 can be switched between a posture in which the dimension in the pressure-receiving direction is reduced as shown in FIG. 3(a) and a posture in which the dimension in the pressure-receiving direction is increased as shown in FIG. 3(c).

[0025] 2.3.Form 3 Fig. 4 shows an explanatory diagram of the jig 30 according to the third embodiment. Fig. 4(a) is a cross-sectional view taken along the extension direction of the jig 30, showing a state in which the dimension in the pressure-receiving direction is reduced, and Fig. 4(b) shows a state in which the jig 30 has been deformed so that the dimension in the pressure-receiving direction is increased, from the same perspective as Fig. 4(a). Here, the "extension direction" is the direction in which the jig 30 is inserted into the hollow member 2, as shown by the arrows in Figs. 1 and 4. As can be seen from these figures, the jig 30 has a bolt 21, a nut 22, an end plate 31, and a pressure-receiving member 32. Here, the bolt 21 and the nut 22 can be considered to be similar to the bolt 21 and the nut 22 of the jig 20 according to the above-mentioned embodiment 2, so they are denoted by the same reference numerals and a description thereof will be omitted.

[0026] The end plate 31 is a plate-like member having a hole through which the shaft portion 21b of the bolt 21 penetrates in the plate thickness direction. In this embodiment, two end plates 31 are arranged, and one end plate 31 is arranged so that the shaft portion 21b of the bolt 21 passes through the hole and one plate surface is in contact with the head portion 21a of the bolt 21. The other end plate 31 is arranged so that the shaft portion 21b of the bolt 21 passes through the hole and one plate surface is in contact with the nut 22. The two end plates 31 are arranged so that the surfaces not in contact with the head portion 21a of the bolt 21 and the nut 22 face each other.

[0027] In this embodiment, the pressure-receiving member 32 is made of a cylindrical elastic body. Examples of materials that can be used to make the elastic body include rubber and elastomer.

[0028] In the jig 30, the nut 22 is screwed onto the shaft portion 21b of the bolt 21, and the end plates 31 are disposed on the head 21a of the bolt 21 and the nut 22, as described above. A pressure-receiving member 32 is disposed between the two opposing end plates 31. The pressure-receiving member 32 is disposed so that the shaft portion 21b of the bolt 21 passes through the cylindrical pressure-receiving member 32, thereby extending in the direction in which the shaft portion 21b of the bolt extends.

[0029] Such a fixture 30 operates as follows. As shown in FIG. 4(a), in a position in which the dimension in the pressure-receiving direction is small, the head 21a of the bolt 21 and the nut 22 are spaced apart by a predetermined distance, and the end plate 31 is also spaced apart in a similar manner. Next, as shown in Fig. 4(b), the nut 22 and the head 21a of the bolt 21 are rotated relatively in the opposite direction to reduce the distance between them. This reduces the gap between the two end plates 31, and the end plates 31 press the elastic pressure-receiving member 32 in the axial direction (extension direction). This causes the elastic pressure-receiving member 32 to deform so as to bulge in the pressure-receiving direction, increasing its dimension in the pressure-receiving direction. This causes at least a part of the outer circumferential surface of the pressure-receiving member 32 to come into contact with or approach the inner surface (surface having the butted portion) of the hollow member 2, thereby supporting the hollow member 2 from the inner surface during friction stir welding. After joining, the distance between the head 21a of the bolt 21 and the nut 22 is increased in the opposite manner to the above, thereby returning to the state shown in FIG. 4(a). In this manner, the jig 30 can be switched between a posture in which the dimension in the pressure-receiving direction is reduced as shown in FIG. 4(a) and a posture in which the dimension in the pressure-receiving direction is increased as shown in FIG. 4(b).

[0030] 2.4.Form 4 FIG. 5 shows a diagram for explaining the jig 40 according to the fourth embodiment. In FIG. 5, the hollow member 2 is also shown for ease of understanding, and the cross section is shown so that the inside of the hollow member 2 can be seen. FIG. 5(a) is a diagram along the extension direction of the jig 40, showing a state in which the dimension in the pressure-receiving direction is reduced, FIG. 5(b) is a partially enlarged view of the multiple pressure-receiving members 41 arranged inside the hollow member 2 in FIG. 5(a), and FIG. 5(c) shows a state in which the jig 40 is deformed so that the dimension in the pressure-receiving direction is increased from the same viewpoint as FIG. 5(b). Here, the "extension direction" is the direction in which the jig 40 is inserted into the hollow member 2, as shown by the arrows in FIG. 1 and FIG. 5. Note that some of the repeated symbols are omitted for ease of viewing. As can be seen from these figures, the jig 40 has a pressure-receiving member 41, a stopper 42, a sprocket 43, and a winder 44.

[0031] In this embodiment, a so-called chain used for power transmission is configured by connecting a plurality of pressure-receiving members 41, and this is disposed inside the hollow member 2. Accordingly, inner links 41a and outer links 41b as the pressure-receiving members 41 are connected alternately in multiples, and the inner links 41a, the outer links 41b, and each of the links connected in a repetitive manner are connected to each other rotatably to form a single whole.

[0032] In this embodiment, protrusions 41c are provided on the inner link 41a. The protrusions 41c are protrusions that protrude toward the surface (the lower surface in FIG. 5) opposite the surface on which the butted portion is located, among the inner surfaces of the hollow member 2. That is, the protrusions 41c are provided on every other arranged link, and protrude in a direction perpendicular to the extension direction when the chain is aligned in a straight line. In addition, protrusion 41c is positioned in a position offset in either direction from the center of the longitudinal direction (the direction in which multiple links are connected) of one of the inner links 41a (in this embodiment, the position where it connects to one of the outer links 41b). 5(a) and 5(b), when the pressure-receiving member 41 is decreasing in size in the pressure-receiving direction, the protrusion 41c comes into contact with the inner surface of the hollow member 2, preventing the links 41a, 41b from aligning in a straight line. This allows the pressure-receiving member 41 to more reliably and smoothly deform to increase in size in the pressure-receiving direction, as described below.

[0033] The stopper 42 is a plate or block-shaped member that is disposed in the opening of the end face of the hollow member 2 and closes at least a part of the opening.

[0034] As shown in Fig. 5(a), the sprockets 43 are a pair of disks, and have teeth on their outer periphery that can mesh with the pressure-receiving member 41, which is a chain. As a result, by disposing the pressure-receiving member 41 between a pair of sprockets 42 and rotating as shown by arrow K in Fig. 5(a), a force can be applied to the pressure-receiving member 41 so as to send the pressure-receiving member 41 into the hollow member 2 as shown by arrow L. For this reason, the sprocket 43 is disposed on the end side of the hollow member 2 opposite the end where the stopper 42 is disposed.

[0035] The winding machine 44 is a roll-shaped member, and is connected to one end of the chain to which multiple pressure-receiving members 41 are linked, the end opposite the end on the stopper 42 side. As a result, by rotating the winding machine 44 as indicated by M in Fig. 5(a), the chain (pressure-receiving member 41) is wound up, and the pressure-receiving member 41 can be moved in the opposite direction to the direction in which the sprocket 43 sends the pressure-receiving member 41 (the opposite direction to the arrow L).

[0036] Such a jig 40 operates as follows. 5(a) and 5(b), in the position where the dimension in the pressure-receiving direction is small, the pressure-receiving members 41 are nearly in a straight line. However, as described above, they are not in a straight line due to the protrusions 41c. Next, when the sprocket 43 is rotated as shown by arrow K in Figure 5(a), each pressure-receiving member 41 receives a force that moves in the direction of arrow L and moves. However, since the end of the chain that connects the pressure-receiving members 41 is supported by a stopper 42, movement in the extension direction is limited. Then, the links rotate relative to each other at the joints, and as shown in Figure 5(c), the dimensions in the pressure-receiving direction are deformed to increase. In this embodiment, the protrusions 41c prevent the multiple pressure-receiving members 41 from lining up in a straight line, so rotation at the joints occurs smoothly in the intended direction. This allows the pressure-receiving member 41 to come into contact with or approach the inner surface (the surface having the butted portion) of the hollow member 2 and support the hollow member 2 from the inner surface during friction stir welding. On the other hand, after joining, the winding machine 44 is rotated in the direction indicated by the arrow M (at this time the sprocket 43 is in a freely rotatable state), thereby returning the position of Figure 5(c) to the position of Figure 5(a) or Figure 5(b). In this manner, the jig 40 can be switched between a posture in which its dimension in the pressure-receiving direction is smaller as shown in Figures 5(a) and 5(b), and a posture in which its dimension in the pressure-receiving direction is larger as shown in Figure 5(c). [Explanation of symbols]

[0037] Reference Signs List 1...tool, 2...hollow member, 10...jig, 11...first pressure-receiving member, 12...second pressure-receiving member, 13...cam member, 20...jig, 21...bolt, 22...nut, 23...pressure-receiving member, 30...jig, 31...end plate, 32...pressure-receiving member, 40...jig, 41...pressure-receiving member, 42...stopper, 43...sprocket, 44...winding machine

Claims

1. A jig that can be inserted into a hollow member to join the hollow member by friction stir welding, The hollow member is capable of changing its dimension in a pressure direction, which is a direction in which the hollow member is pressed by a tool of the friction stir welding. jig.

2. The jig according to claim 1 , wherein the jig has a cam member, and the dimension in the pressure-receiving direction changes with rotation of the cam member.

3. The jig according to claim 1, comprising a plurality of members each having an inclined surface, and by pressing the plurality of members together, the plurality of members slide relative to one another on the inclined surfaces, thereby changing the dimension in the pressure direction.

4. The jig according to claim 1 , further comprising an elastic body, the dimension of which in the pressure-receiving direction changes when the elastic body is pressed.

5. The jig described in claim 1, wherein the jig has a member formed by connecting a plurality of links that can rotate relative to one another, and when a force is applied in the direction in which the member extends, the links rotate relatively to one another, thereby changing the dimension in the pressure-receiving direction.

6. The jig according to claim 5 , wherein every other link is provided with a protrusion, and the protrusions protrude in a direction perpendicular to a direction in which the member extends.

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