Method for manufacturing jigs and joints

Abstract

To provide a jig or the like that can absorb the deformation of the joint due to thermal shrinkage in friction stir welding. [Solution] The first member 11 is held between the table 2 and the first clamp 3, and the second member 12 is pressed against the first member 11 toward the table 2 by the second clamp 4. The jointed body 10 is formed by friction stir welding of the first member 11 and the second member 12 which are fixed in this manner. During this friction stir welding, the pressing support 5 presses the first member 11 from the table 2 side inside the annular route to be joined (inner route L1 and outer route L2), pre-deforming the first member 11 and the second member 12 into a convex shape. As a result, the convex deformation by the pressing support 5 can absorb the concave deformation of the jointed body 10 that occurs due to thermal shrinkage during friction stir welding.

Description

Technical Field

[0001] The present invention relates to a jig and a method for manufacturing a joined body, and particularly to a jig and a method for manufacturing a joined body that can absorb deformation of the joined body due to thermal shrinkage during friction stir welding.

Background Art

[0002] Patent Document 1 describes a technique for forming a joined body by friction stir welding a metal first member and a second member in a circular route while fixing them to a jig. This jig includes a table that supports the first member from below, a first clamp that sandwiches the first member between the table, and a second clamp that presses the second member against the first member toward the table side. Further, friction stir welding is a joining method in which the amount of heat input during joining is generally less than that of arc welding or the like, and the thermal shrinkage of the joined body is small, but some thermal shrinkage occurs.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional technique, when thermal shrinkage of the joined body occurs due to friction stir welding along a circular route, the joined body may be deformed concavely toward the table side such that the central portion of the route becomes a valley bottom.

[0005] The present invention has been made to solve the above-described problems, and an object thereof is to provide a jig and a method for manufacturing a joined body that can absorb deformation of the joined body due to thermal shrinkage during friction stir welding.

Means for Solving the Problems

[0006] To achieve this objective, the present invention provides a jig for fixing a first metal member and a second metal member when friction stir welding them together in an annular route to form a joint, and comprises a table for supporting the first member, a first clamp for clamping the first member between itself and the table, a second clamp for pressing the second member toward the table toward the first member, and a pressing support for pressing the first member from the table toward the inside of the annular route. [Effects of the Invention]

[0007] According to the jig described in claim 1, the first member is clamped between the table and the first clamp, and the second member is pressed against the first member toward the table by the second clamp. The first and second members, fixed in this manner, are friction stir welded to form a joint. During this friction stir welding, the first member is pressed from the table side inside the annular route to be joined by the pressing support. This allows the first and second members to be pre-deformed into a convex shape so that the pressed positions bulge relative to the positions of the first and second clamps, and then friction stir welded. As a result, the convex deformation caused by the pressing support can absorb the concave deformation of the joint (first and second members) due to thermal shrinkage during friction stir welding.

[0008] The jig described in claim 2 provides the following effects in addition to those of the jig described in claim 1. During friction stir welding, the first member is pressed from the table side by the pressing support at the position of the center of gravity of the surface outlined by the annular route to be joined (approximately the position of the central part of that route). As a result, the convex deformation caused by the pressing support makes it easier to absorb the concave deformation of the joined body due to thermal shrinkage during friction stir welding.

[0009] The jig described in claim 3 provides the following effects in addition to those of the jig described in claim 2: The position of the center of gravity of the surface outlined by the annular root to be joined is uniquely determined even if the root has an asymmetrical shape, and can also approximate the position of the valley bottom when the joined body deforms into a concave shape due to thermal shrinkage during friction stir welding. Since the pressing support presses on this center of gravity, it can effectively absorb the concave deformation even if the root has an asymmetrical shape, and can also facilitate the homogenization of the quality of the joined body.

[0010] The jig described in claim 4 provides the following effects in addition to the effects of the jig described in claim 2. The route includes an annular outer route and an annular inner route provided inside the outer route. The pressing support is positioned to press on the position of the combined center of gravity of the surface outlined by the outer route and the surface outlined by the inner route. This allows both the deformation of the joint due to thermal shrinkage during the joining of the outer route and the deformation of the joint due to thermal shrinkage during the joining of the inner route to be efficiently absorbed by the deformation of the pressing support.

[0011] The jig described in claim 5 provides the following effects in addition to the effects of the jig described in claim 4. The pressing support is positioned to press the position of the composite center of gravity and also to press the position of the center of gravity of the surface outlined by the outer route. Here, because the outer route is larger than the inner route, deformation of the joint due to thermal shrinkage during joining of the outer route tends to be dominant. By pressing the center of gravity of the outer route with the pressing support, this dominant deformation can be more easily absorbed by the deformation of the pressing support.

[0012] The jig described in claim 6 provides the following effects in addition to the effects of the jig described in claim 2. The route includes an annular outer route and an annular inner route provided inside the outer route. The pressing support is positioned to press the position of the center of gravity of the surface outlined by the outer route, and also to press the position of the center of gravity of the surface outlined by the inner route. This allows the deformation of the joint due to thermal shrinkage during the joining of the outer route and the deformation of the joint due to thermal shrinkage during the joining of the inner route to be absorbed by the deformation of the pressing support.

[0013] The method for manufacturing a joint according to claim 7 is a method for manufacturing a joint by friction stir welding a first member and a second member using a jig according to any one of claims 1 to 6, and it has the same effect as the jig according to any one of claims 1 to 6. Of course, the joint may also be manufactured by friction stir welding a first member and a second member using a jig according to claim 7 or 8. [Brief explanation of the drawing]

[0014] [Figure 1] This is a top view of the jig in the first embodiment. [Figure 2] This is a cross-sectional view of the jig along line II-II in Figure 1. [Figure 3] This is a top view of the jig with the first component fixed in place. [Figure 4] This is a schematic diagram illustrating how to use the jig. [Figure 5] This is a schematic diagram illustrating how to use the jig. [Figure 6] This is a top view of the first and second members during friction stir welding. [Figure 7] (a) is a schematic top view of the jig and joint in the second embodiment, and (b) is a schematic cross-sectional view of the jig and joint along the line VIIb-VIIb in Figure 7(a). [Figure 8] (a) is a schematic top view of the jig and joint in the third embodiment, and (b) is a schematic top view of the jig and joint in the fourth embodiment. [Modes for carrying out the invention]

[0015] Hereinafter, preferred embodiments will be described with reference to the accompanying drawings. FIG. 1 is a top view of the jig 1 in the first embodiment. FIG. 2 is a cross-sectional view of the jig 1 taken along line II-II of FIG. 1, and illustration of a part of the jig 1 that is visible deeper than the cross-section is omitted. The jig 1 is for fixing the first member 11 and the second member 12 when friction stir welding the first member 11 and the second member 12 to form the joined body 10 (both are referred to FIG. 6), and each part is driven by hydraulic pressure and pneumatic pressure. Since the hydraulic source, pneumatic source, hydraulic circuit, and pneumatic circuit of the jig 1 are common, their explanations and illustrations are omitted.

[0016] As shown in FIGS. 1 and 2, the jig 1 mainly includes a table 2, a first clamp 3, a second clamp 4, a pressing support 5, and a lifting support 6. In FIG. 1, the first clamp 3 in the fixed state is shown by a two-dot chain line, and the first clamp 3 in the non-fixed state is shown by a solid line. Similarly, in FIGS. 1 and 2, the second clamp 4 in the fixed state is shown by a two-dot chain line, and the second clamp 4 in the non-fixed state is shown by a solid line. Also, for the sake of simplifying the following description, the vertical direction in FIG. 2 will be described as the vertical direction of the jig 1. However, the vertical direction of the jig 1 is the vertical direction in this embodiment, but it may be inclined with respect to the vertical direction or coincide with the horizontal direction.

[0017] The table 2 includes a lower table 21 fixed on the base (not shown) of the jig 1. The lower table 21 is a rectangular plate material when viewed in the vertical direction, and its plate thickness direction coincides with the vertical direction of the jig 1. From the four corners of the upper surface of the lower table 21, one support column 22 rises upward.

[0018] The upper table 23 is spanned and fixed to the upper ends of the four support columns 22. The upper table 23 is a rectangular plate material when viewed in the vertical direction. The upper table 23 is arranged in parallel with a gap above the lower table 21 and is arranged at a position overlapping the lower table 21 when viewed in the vertical direction.

[0019] On the upper surface of the upper table 23, one seating part 23a is attached at a position away from the four corners toward the inside. From each of the four seating parts 23a, a columnar reference seat 23b protrudes upward. Further, from two of the four seating parts 23a, a columnar positioning pin 23d protrudes upward from the upper surface of the seating part 23a near the reference seat 23b. The positioning pin 23d protrudes higher upward than the reference seat 23b.

[0020] The reference seat 23b is a part for accurately positioning and supporting the first member 11 (see Fig. 4(a)) on the table 2. When the first member 11 is placed on the upper ends of the four reference seats 23b, the first member 11 is supported from below by the table 2. Note that the number and arrangement of the seating parts 23a and the reference seats 23b are not limited to the case illustrated in this embodiment and may be appropriately changed according to the shape of the first member 11.

[0021] Near each of the reference seats 23b, one nozzle 23c is attached to the upper surface of the upper table 23. The tip of this nozzle 23c is directed toward the upper end of the reference seat 23b. Just before placing the first member 11 on the upper end of the reference seat 23b, by blowing compressed air from the tip of the nozzle 23c, dust and dirt are removed from the upper end of the reference seat 23b. This enables more accurate positioning of the first member 11 on the table 2.

[0022] Also, near each of the reference seats 23b on the upper surface of the upper table 23, one first clamp 3 is attached. The first clamp 3 is for clamping the first member 11 together with the reference seat 23b. The first clamp 3 is a known hydraulic link clamp and is configured to spring the arm 31 upward when the hydraulic pressure is released and to tilt the arm 31 when the hydraulic pressure is supplied. The state where the arm 31 is sprung upward is the non-fixed state shown by the solid line in Fig. 1, and the state where the arm 31 is tilted is the fixed state shown by the two-dot chain line in Fig. 1. In the fixed state, the arm 31 overlaps the reference seat 23b in the vertical view.

[0023] Around the area enclosed by the four first clamps 3 on the upper surface of the upper table 23, a number of second clamps 4 (five in this embodiment) are attached in positions that do not interfere with the first clamps 3. The second clamps 4 are for pressing and fixing the second member 12 (see Figure 5(b) for both) to the first member 11. The second clamps 4 are known air swing clamps, in which an arm 42 extending perpendicular to the axis of a rod 41 is fixed to the end of a rod 41 that is movable up and down and rotatable.

[0024] When the air pressure is released, the second clamp 4 retracts the tip of the arm 42 away from the center of the upper table 23, resulting in the unfixed state shown by the solid line in Figure 1. When air pressure is supplied to the second clamp 4, the rod 41 rotates approximately 90 degrees and descends so that the tip of the arm 42 extends towards the center of the upper table 23. After this rotation, further supply of air pressure causes the rod 41 and arm 42 to descend further, resulting in the fixed state shown by the dashed line in Figure 2.

[0025] Furthermore, a pressing portion 43 protrudes from the lower surface of the tip of the arm 42. The lower end surface of the pressing portion 43 is formed by a flat surface perpendicular to the vertical direction. In the fixed state, this lower end surface of the pressing portion 43 is pressed precisely against the second member 12.

[0026] A through-hole 23e is formed in the center of the upper table 23, penetrating it vertically, and a pressing support 5 is provided so as to pass through this through-hole 23e. The pressing support 5 raises and lowers its pressing tip 51 relative to the table 2 in two stages using a first lifting unit 52 and a second lifting unit 53, and only one is provided on the jig 1.

[0027] The pressing tip 51 is a rectangular parallelepiped-shaped metal part, and its upper surface is configured to be in contact with the first member 11 (see Figure 4(a)). The shape of the pressing tip 51 is set to match the shape of the lower surface of the first member 11 at the position where the pressing tip 51 makes contact. The upper surface may be circular or polygonal, and steps or indentations may be formed on the upper surface.

[0028] The pressing tip 51 is attached to the upper end of the first lifting section 52 via a spacer 51a. The spacer 51a is used to set the height of the upper surface of the pressing tip 51 to match the height of the lower surface of the first member 11 at the position where the pressing tip 51 makes contact. Therefore, the vertical dimension of the spacer 51a is set according to the height of the lower surface of the first member 11. Alternatively, depending on the height of the lower surface of the first member 11, the spacer 51a may be omitted, and the pressing tip 51 may be directly attached to the upper end of the first lifting section 52.

[0029] The first lifting section 52 is a hydraulic work support for maintaining the pressing tip 51 in contact with the first member 11. Since known configurations can be used, a general overview will be given below, and a detailed explanation will be omitted. An example of a known configuration is the work support 2 described in Japanese Patent Application Publication No. 2003-307205. Figure 2 schematically shows the internal structure of the first lifting section 52.

[0030] The first lifting section 52 comprises a substantially cylindrical housing 52a and a rod 52b protruding upward from the upper end of the housing 52a. A vertically movable piston 52c is provided inside the housing 52a. A vertically compressible coil spring 52d is placed on top of the piston 52c. The rod 52b is placed on top of the coil spring 52d.

[0031] The rod 52b moves up and down as the movement of the piston 52c is transmitted via the coil spring 52d. The amount of protrusion of the rod 52b from the housing 52a changes with this movement. The pressing tip 51 is attached to the upper end of the rod 52b via a spacer 51a. That is, the first lifting unit 52 raises and lowers the pressing tip 51 by raising and lowering the rod 52b.

[0032] The first lifting section 52 incorporates a pressure locking section 52e. The pressure locking section 52e is a known hydraulic collet chuck and can be switched between a locked state and an unlocked state. In the locked state of the pressure locking section 52e, the cylindrical collet (not shown) of the pressure locking section 52e is reduced in diameter and pressed against the outer surface of the rod 52b, thereby locking the lifting and lowering of the rod 52b and the pressing tip 51. In the unlocked state of the pressure locking section 52e, the collet is expanded in diameter and moved away from the rod 52b, allowing the rod 52b and the pressing tip 51 to move up and down.

[0033] When the hydraulic pressure is released, the first lifting section 52 has its pressing lock section 52e unlocked and the piston 52c is in its lowest position, so the rod 52b is retracted to its maximum extent into the housing. In other words, when the hydraulic pressure is released, the first lifting section 52 is retracted to its shortest length, and the pressing tip 51 has descended to its lowest position.

[0034] When hydraulic pressure is supplied to the first lifting section 52, the piston 52c first rises due to the hydraulic pressure. At this time, since the pressing lock section 52e remains unlocked, the rod 52b is pushed upward from the housing 52a via the coil spring 52d, and the pressing tip 51 rises. After the pressing tip 51 contacts the first member 11, even if the piston 52c rises further, the coil spring 52d is compressed, so the pressing tip 51 does not press the first member 11 in principle. This is because the elastic force of the coil spring 52d is set to be sufficiently weak. When the piston 52c has risen to its highest point, hydraulic pressure is supplied to the pressing lock section 52e, switching it to the locked state and locking the lifting and lowering of the pressing tip 51.

[0035] Furthermore, the housing 52a of the first lifting section 52 is fixed to a sliding section 54 attached to the upper end of the second lifting section 53. The sliding section 54 is the part that is inserted into the through hole 23e and slides vertically within the through hole 23e by the second lifting section 53. A female thread is formed on the inner circumferential surface of the mounting recess 54a provided at the upper end of the sliding section 54, and the first lifting section 52 is fixed to the sliding section 54 by screwing a male thread formed on the outer circumferential surface of the housing 52a into this female thread.

[0036] The second lifting section 53 is a known linear hydraulic cylinder and comprises a cylinder body fixed to the lower table 21 and a rod 53a protruding upward from the upper end of the cylinder body. When hydraulic pressure is released, the rod 53a is retracted into the cylinder body, causing the second lifting section 53 to contract vertically. When hydraulic pressure is supplied, the rod 53a is pushed upward from the cylinder body, causing the second lifting section 53 to extend vertically. A sliding section 54 is attached to the upper end of the rod 53a, and when the second lifting section 53 extends or retracts, the pressing tip 51 moves up and down relative to the table 2 via the sliding section 54 and the first lifting section 52.

[0037] The lower end of the sliding portion 54 protrudes downward from the lower surface of the upper table 23, and an annular flange portion 54b extends outward from the outer peripheral surface of the lower end of the sliding portion 54. An annular adjustment plate 54c having a predetermined thickness is placed on the upper surface of the flange portion 54b. When the parts above the sliding portion 54 (such as the pressing tip portion 51) are raised by the second lifting unit 53, the adjustment plate 54c comes into contact with the lower surface of the upper table 23, thereby restricting their upward movement. In other words, by adjusting the thickness of the adjustment plate 54c, the amount of upward movement of the pressing tip portion 51 from the time the hydraulic pressure is released by the second lifting unit 53 can be easily adjusted.

[0038] Multiple (13 in this embodiment) lifting supports 6 protrude from the upper surface of the upper table 23 around the pressing support 5. The lifting supports 6 raise and lower their lifting tip 61 relative to the table 2 by a lifting section 62, and are configured substantially the same as the pressing support 5, except that the second lifting section 53 and the sliding section 54 are removed.

[0039] The lifting tip 61 is a metal part that is substantially identical in structure to the pressing tip 51, and its upper surface is configured to be in contact with the first member 11. The shape of the lifting tip 61 is set to match the shape of the lower surface of the first member 11 at the position where the lifting tip 61 makes contact. Also, similar to the pressing tip 51, the lifting tip 61 can be attached to the upper end of the lifting section 62 via a spacer 61a, or directly attached to the upper end of the lifting section 62, depending on the height of the lower surface of the first member 11 at the contact position.

[0040] The lifting section 62 is a hydraulic work support configured substantially the same as the first lifting section 52, and can employ work support 2 as exemplified in Japanese Patent Publication No. 2003-307205. Figure 2 schematically shows the internal structure of the lifting section 62 of the lifting support 6 adjacent to the left side of the pressing support 5, and the internal structure of the lifting sections 62 of the other lifting supports 6 is not shown.

[0041] The lifting section 62 comprises a housing 62a, a rod 62b, a piston 62c, a coil spring 62d, and a lifting locking section 62e. The housing 62a is substantially identical in configuration to the housing 52a of the first lifting section 52. Similarly, the rod 62b is substantially identical to the rod 52b, the piston 62c is substantially identical to the piston 52c, the coil spring 62d is substantially identical to the coil spring 52d, and the lifting locking section 62e is substantially identical to the pressing locking section 52e.

[0042] The operation of each part of the lifting section 62 during hydraulic supply and release is substantially the same as that of the first lifting section 52. While the first lifting section 52 is fixed to the sliding section 54, the lifting section 62 is fixed to the upper table 23. This fixing is performed by screwing a male thread formed on the outer circumferential surface of the housing 62a into a female thread formed on the inner circumferential surface of a mounting recess 23f that opens onto the upper surface of the upper table 23.

[0043] Next, with reference to Figures 3 to 6, a method for using the jig 1 and a method for manufacturing the joined body 10 using the jig 1 will be explained. Figure 3 is a top view of the jig 1 with the first member 11 fixed in place. Figures 4(a) to 5(b) are schematic diagrams illustrating the method for using the jig 1. Figure 6 is a top view of the first member 11 and the second member 12 during friction stir welding.

[0044] As shown in Figure 6, the joint 10 is formed by friction stir welding of the first member 11 and the second member 12 along an annular inner route L1 and an annular outer route L2. The inner route L1 is set inside the outer route L2. Figure 6 shows the case where friction stir welding along the inner route L1 is completed and friction stir welding along the outer route L2 is in progress. In Figure 6, the portion of the outer route L2 where friction stir welding is incomplete is indicated by a dashed line.

[0045] The joint 10 of this embodiment is a liquid cooling jacket for cooling an engine, motor, etc. The first member 11 is the jacket body of the liquid cooling jacket, and has a groove 11a that opens on its upper surface. In Figure 6, the groove 11a, the support column 11c surrounded by the groove 11a, and the upper surface (pressing tip 51) of the pressing support 5 positioned directly below the support column 11c are shown by dashed lines.

[0046] The second member 12 is a lid member that is placed on top of the first member 11 so as to block the groove 11a, and is made of a metal plate. The groove 11a blocked by the second member 12 is a cooling passage, and by passing a coolant (for example, water or antifreeze) through this cooling passage, the joint 10 is used as a liquid-cooled jacket. In addition, in order to prevent the coolant from leaking from the groove 11a (cooling passage) into the gap between the first member 11 and the second member 12, the inner route L1 and outer route L2 of the friction stir welding are set near the groove 11a so as to follow the groove 11a.

[0047] In this embodiment, friction stir welding is performed by rotating a known friction stir welding tool T and inserting the pin of the tool T into the overlapping portion of the first member 11 and the second member 12 from above the second member 12, thereby softening them with frictional heat and stirring them to join them together. When friction stir welding is performed on the annular inner route L1 or the annular outer route L2, the joined body 10 may shrink due to frictional heat, causing the joined body 10 to deform downwards (to the opposite side of the tool T) into a concave shape, with the central part of each route becoming the bottom of the valley. The jig 1 of this embodiment fixes the first member 11 and the second member 12 in such a way as to absorb this concave deformation.

[0048] As shown in Figures 3 and 4(a), the first member 11 is a metal plate that is roughly rectangular in shape when viewed from above, and has a convex portion 11b formed on its upper surface. This convex portion 11b is a raised area that is stepped relative to its surroundings where the second member 12 is placed, and its upper surface is formed to be flat. A groove 11a is formed on the upper surface of this convex portion 11b, opening at a position away from the outer edge of the convex portion 11b. The first member 11 also has a support portion 11c that is surrounded all around by the groove 11a. This support portion 11c is formed in a cylindrical shape with its upper end closed and its lower end open.

[0049] Multiple (two in this embodiment) positioning pins 11e protrude from the upper surface of the first member 11 around the convex portion 11b. When the second member 12 is placed on top of the first member 11, these positioning pins 11e fit into multiple (two in this embodiment) positioning recesses 12a (see Figure 6) formed through the second member 12, thereby positioning the second member 12 in the front, back, left, and right directions relative to the first member 11.

[0050] Various known methods can be used for this positioning method. For example, the second member 12 may be provided with multiple positioning pins, and the first member 11 may be provided with multiple positioning recesses into which these pins fit. Alternatively, a recessed fitting portion 11f (see Figure 7(b)) may be formed on the upper surface of the first member 11 so as to fit substantially the entire second member 12. Alternatively, the convex portion 11b may be omitted from the first member 11, and the upper surface of the first member 11 at the position where the second member 12 overlaps may be made flush with the surrounding surface. However, it is preferable to ensure the smoothness of the upper surface of the first member 11 at the position where the second member 12 overlaps by cutting or grinding the upper surface of the convex portion 11b, or by creating the recessed fitting portion 11f by milling.

[0051] To manufacture the joined body 10 by joining the first member 11 and the second member 12, first release the hydraulic or pneumatic pressure from each part of the jig 1, and leave the first clamp 3 and the second clamp 4 in an unfixed state as shown in Figures 1 and 2. Furthermore, lower the pressing tip 51 of the pressing support 5 and the lifting tip 61 of the lifting support 6 to their lower limit positions.

[0052] Next, as shown in Figures 3 and 4(a), the first member 11 is placed on the multiple reference seats 23b of the table 2. At this time, the multiple (two in this embodiment) positioning pins 23d of the table 2 fit into the multiple (two in this embodiment) positioning recesses 11d formed through the first member 11, thereby positioning the first member 11 in the front, back, left, and right directions relative to the table 2.

[0053] After placing the first member 11 on the table 2, the second member 12 is placed on top of the first member 11 while fitting the positioning pin 11e of the first member 11 into the positioning recess 12a (see Figure 6) of the second member 12. Then, hydraulic pressure is supplied to the multiple first clamps 3 to lower the arm 31 and switch the first clamps 3 to a fixed state (clamping step). As a result, the first member 11 is clamped between the multiple reference seats 23b and the multiple first clamps 3, and the first member 11 is fixed to the jig 1.

[0054] In this fixed state, the pressing support 5 and the multiple lifting supports 6 are located below the first member 11, as shown by the dashed lines in Figure 3. Furthermore, in a vertical view, the pressing support 5 and the multiple lifting supports 6 are positioned near the groove 11a so as to follow the edge of the groove 11a of the first member 11. In particular, the pressing support 5 and some of the lifting supports 6 are positioned directly below the support column 11c of the first member 11, with their pressing tip 51 and lifting tip 61 positioned on the inner circumference side of the support column 11c.

[0055] After fixing the first member 11 to the jig 1, hydraulic pressure is supplied to the first lifting section 52 of the pressing support 5 to extend the first lifting section 52. As a result, the pressing tip 51 rises from the lower limit position shown by the dashed line in Figure 4(a), and the pressing tip 51 comes into contact with the first member 11 as shown by the solid line in Figure 4(a). As described above, the first lifting section 52 brings the first member 11 into contact with the first member 11 without actually pressing it with the pressing tip 51, and the built-in pressing lock section 52e (see Figure 2) locks the pressing tip 51 in contact with the first member 11.

[0056] Next, as shown in Figure 4(b), hydraulic pressure is supplied to the second lifting section 53 of the pressing support 5 to extend the second lifting section 53, thereby raising the sliding section 54, the first lifting section 52, and the pressing tip 51, and the pressing tip 51 presses the first member 11 from below (deformation step). As a result, the first member 11 deforms into a convex shape so that the pressing position by the pressing support 5 rises relative to the fixed position by the first clamp 3. Note that in Figure 4(b), the amount of deformation of the first member 11 is exaggerated (the same applies to Figures 5(a), 5(b), and 7(b)). The actual amount of deformation is several hundred μm to several mm.

[0057] After this deformation, as shown in Figure 5(a), hydraulic pressure is supplied to each of the lifting sections 62 of the multiple lifting supports 6 to extend the lifting sections 62, thereby raising the lifting tip 61 and bringing it into contact with the first member 11. As described above, the lifting sections 62 bring them into contact with the first member 11 without essentially pressing the lifting tip 61 against it, and the built-in lifting locking section 62e (see Figure 2) locks the lifting tip 61 in contact with the first member 11.

[0058] Next, as shown in Figure 5(b), air pressure is supplied to the second clamp 4 to switch it to a fixed state (pressing step). The pressing portion 43 of the second clamp 4 presses the second member 12 against the first member 11 toward the table 2, and the second member 12 is fixed to the jig 1. At this time, the second member 12 deforms into a convex shape, similar to the first member 11, such that the pressing position by the pressing support 5 rises relative to the fixed position by the second clamp 4.

[0059] Once the first member 11 and the second member 12 are fixed to the jig 1, the first member 11 and the second member 12 are friction stir-welded using the tool T (joining step). As shown in Figure 6, the jointed body 10 is formed by friction stir-welding the support portion 11c of the first member 11 and the second member 12 using the inner route L1, and then friction stir-welding the first member 11 and the second member 12 using the outer route L2.

[0060] Although not shown in the diagram, multiple second clamps 4 are pressed against the second member 12 on the outer route L2. When the tool T approaches a second clamp 4, the second clamp 4 is switched to an unfixed state to perform friction stir welding. Alternatively, by setting the pressing position of the second clamp 4 against the second member 12 so that the tool T does not interfere with the second clamp 4, it may be unnecessary to switch the second clamp 4 to an unfixed state during welding. Finally, the joined body 10 is removed from the jig 1 by releasing the hydraulic and pneumatic pressure in each part of the jig 1.

[0061] According to the jig 1 (method for manufacturing the joined body 10) described above, the first member 11 and the second member 12 can be friction stir-bonded in a state where they have been pre-deformed into a convex shape by the pressing support 5. This convex deformation by the pressing support 5 can absorb the concave deformation of the joined body 10 (first member 11 and second member 12) that occurs due to thermal shrinkage during friction stir bonding.

[0062] Furthermore, the concave deformation of the joint 10 due to thermal shrinkage occurs both when joining along the inner route L1 and when joining along the outer route L2. In addition, the amount of this concave deformation tends to be greater in the parts that are further inward from the annular routes L1 and L2.

[0063] The portion furthest inward from the inner route L1 can be approximated to the position of the centroid W1 of the surface outlined by the inner route L1, and therefore the position of the valley bottom due to deformation during joining of the inner route L1 can also be approximated to the position of the centroid W1. Similarly, the portion furthest inward from the outer route L2 can be approximated to the position of the centroid W2 of the surface outlined by the outer route L2, and therefore the position of the valley bottom due to deformation during joining of the outer route L2 can also be approximated to the position of the centroid W2. Note that the centroids W1 and W2 of the surfaces outlined by each route L1 and L2 are the centroids when the mass per unit area of ​​that surface is uniform, and are not the centroids of the first member 11 or the second member 12 inside each route L1 and L2.

[0064] By combining the deformations of each route L1 and L2 during joining, the final position of the valley bottom when the joined body 10 deforms into a concave shape due to thermal contraction can be determined. This valley bottom position can be approximated to the position of the combined centroid W12 of centroids W1 and W2. The combined centroid W12 lies on the line segment connecting centroids W1 and W2, and is determined such that the ratio of "distance between centroid W1 and combined centroid W12" : "distance between centroid W2 and combined centroid W12" matches the ratio of "area of ​​the surface outlined by the outer route L2" : "area of ​​the surface outlined by the inner route L1".

[0065] In this embodiment, the pressing support 5 of the jig 1 presses the first member 11 at the position of the combined center of gravity W12, thereby deforming the first member 11 and the second member 12 into a convex shape such that the position of the combined center of gravity W12 becomes the peak (or near the peak). As a result, both the deformation during joining of each route L1 and L2 can be efficiently absorbed by the deformation caused by the pressing support 5. Consequently, a highly accurate joined body 10 with minimal deformation due to thermal shrinkage can be manufactured.

[0066] Furthermore, since the outer route L2 is larger than the inner route L1, the deformation during joining of the outer route L2 tends to be more dominant than the deformation during joining of the inner route L1. The pressing support 5 in this embodiment presses on the position of the combined center of gravity W12 and also on the position of the center of gravity W2 of the outer route L2, so this dominant deformation can be easily absorbed by the deformation of the pressing support 5. As a result, a more precise joined body 10 can be manufactured.

[0067] In this embodiment, the pressing support 5 presses not only the position of the combined center of gravity W12 and the position of the center of gravity W2 of the outer route L2, but also the position of the center of gravity W1 of the inner route L1. Therefore, both the deformation of the routes L1 and L2 during joining can be absorbed more efficiently by the deformation of the pressing support 5. As a result, a more precise joined body 10 can be manufactured.

[0068] Furthermore, since each route L1 and L2 has an asymmetric shape in terms of front, back, left, and right, the deformation when each route L1 and L2 are joined becomes complex, and the part furthest inward from each route L1 and L2 is not necessarily the bottom of the valley. However, the fact that the amount of deformation tends to be larger in parts further inward from each route L1 and L2 remains unchanged, so the positions of the centers of gravity W1 and W2 and the combined center of gravity W12 can be approximated as the positions of the bottoms associated with the individual joining of each route L1 and L2, or the positions of the bottoms associated with the joining of both. The pressing support 5 presses on the position of this combined center of gravity W12, etc., so even if each route L1 and L2 has an asymmetric shape, it can effectively absorb the concave deformation of the joined body 10 due to thermal shrinkage.

[0069] Furthermore, the positions of the centers of gravity W1, W2 and the combined center of gravity W12 are uniquely determined even if each of the routes L1 and L2 has an asymmetrical shape. For example, these positions can be calculated using the functions of commercially available CAD software. Therefore, even if each of the routes L1 and L2 has an asymmetrical shape, the pressing position by the pressing support 5 is less likely to vary, making it easier to homogenize the joined body 10.

[0070] The amount of deformation of the first member 11 and the second member 12 by the pressing support 5 is set according to the amount of deformation of the joint 10 formed without deformation by the pressing support 5. Specifically, first, using the jig 1, but without supplying hydraulic pressure to the second lifting section 53 of the pressing support 5, the first member 11 and the second member 12, which are not deformed into a convex shape, are friction stir-bonded to form a joint 10 that is deformed into a concave shape.

[0071] At the position of the combined center of gravity W12, the amount of deformation of the upper surface of the second member 12 of the joined body 10, which has been deformed into a concave shape, is measured relative to the upper surface of the second member 12 before joining. The amount of springback (elastic recovery) when the first member 11 and the second member 12 are deformed by the pressing support 5 is added to this measured amount of deformation to calculate the amount of pressing deformation. If there are no changes in the material or shape of the first member 11 or the second member 12 as calculated in this way, in subsequent manufacturing of the joined body 10, the first member 11 and the second member 12 are deformed into a convex shape by the pressing support 5 at the position of the combined center of gravity W12 by the amount of the calculated amount of pressing deformation. This makes it easier to absorb deformation due to thermal shrinkage by deformation by the pressing support 5, making it easier to bring the amount of deformation after joining closer to zero compared to before joining, that is, it is possible to manufacture a joined body 10 with even higher precision.

[0072] Here, each time multiple joints 10 are formed using the same jig 1, the height of the first member 11 from the table 2 at the position pressed by the pressing support 5 may vary due to manufacturing errors in the first member 11, etc. If such variations occur, and the amount of rise of the pressing tip 51 of the pressing support 5 relative to the table 2 is the same each time, the amount of deformation of the first member 11 and the second member 12 due to the pressing support 5 will vary, which may reduce the accuracy of the joint 10.

[0073] In contrast, as described above, the pressing support 5 locks the raising and lowering of the pressing tip 51 by the first lifting unit 52 while the pressing tip 51 is in contact with the first member 11 without pressing, and then raises the locked pressing tip 51 with the second lifting unit 53 to press the first member 11. As a result, even if the above fluctuations occur each time multiple joints 10 are formed, if the amount of upward movement of the second lifting unit 53 is approximately constant (for example, the same as the amount of pressing deformation described above), the amount of deformation of the first member 11 and the second member 12 by the pressing support 5 can be kept approximately constant. As a result, a joint 10 with even higher precision can be manufactured.

[0074] Furthermore, in order to deform the first member 11, etc., by the calculated amount of pressure deformation, the thickness of the adjustment plate 54c should be adjusted so that the amount of each part raised by the second lifting section 53 from the hydraulic release (lower limit position) until the adjustment plate 54c hits the upper table 23 is the same as the amount of pressure deformation. Since the amount of the second lifting section 53 is easily kept approximately constant each time by the adjustment plate 54c, a more highly accurate jointed body 10 can be manufactured. In addition, the amount of rise by the second lifting section 53 can be easily adjusted by changing the thickness of the adjustment plate 54c.

[0075] When the first member 11 is deformed by the pressing support 5, the spacing between the multiple positioning pins 11e on the first member 11 widens, and there is a risk that the deformed multiple positioning pins 11e will not be able to be inserted into the multiple positioning recesses 12a of the second member 12. In contrast, in this embodiment, the second member 12 is placed on top of the first member 11 before the first member 11 is deformed by the pressing support 5, so that the inability to insert the positioning pins 11e into the positioning recesses 12a as described above can be suppressed.

[0076] Furthermore, it is preferable that one of the two positioning recesses 12a be a circular hole, and the other be an elongated hole that is linearly long in the direction connecting the two positioning recesses 12a. This elongated hole can absorb positional misalignment of each part, including tolerances of the positioning pin 11e, and can also suppress the deformation of the first member 11 by the pressing support 5 from being hindered by the second member 12. Moreover, by using the circular hole as a reference, the positional accuracy of the first member 11 and the second member 12 before and after deformation can be improved.

[0077] In this embodiment, since the joint is made at the inner route L1 and then at the outer route L2, the strain of the second member 12, which is relatively prone to deformation because it is flat, can be easily released to the outside of the outer route L2. This makes it possible to manufacture a highly accurate jointed body 10.

[0078] Furthermore, as shown in Figure 5(b), etc., during friction stir welding, multiple lifting supports 6 are made to follow the first member 11 which has been deformed into a convex shape by the pressing support 5, and the first member 11 is also supported by multiple lifting supports 6 between the first clamp 3 and the pressing support 5. This support allows for stable friction stir welding of the convexly deformed first member 11 and second member 12, and enables the manufacture of a highly accurate jointed body 10.

[0079] In a vertical view, as shown in Figure 3, multiple lifting supports 6 are positioned near the groove 11a of the first member 11 so as to follow its edge, and as shown in Figure 6, each route L1 and L2 is also set near the groove 11a so as to follow the groove 11a. That is, multiple lifting supports 6 are positioned near each route L1 and L2 so as to follow them. During friction stir welding, the tool T moving along each route L1 and L2 is pressed downward against the second member 12, but the downward displacement of the first member 11 and the second member 12 due to this pressing can be restricted by the multiple lifting supports 6. As a result, the depth of the joining area by the tool T can be homogenized, and a highly accurate joined body 10 can be manufactured.

[0080] Furthermore, as shown by the dashed line in Figure 1, the pressing portion 43 of the fixed second clamp 4 is located approximately directly above the multiple lifting supports 6, making it easier to clamp the first member 11 and the second member 12 between the lifting support 6 and the pressing portion 43 during friction stir welding. This makes it easier to deform the second member 12 to conform to the first member 11, which has been deformed into a convex shape by the pressing support 5, thereby enabling the manufacture of a highly accurate jointed body 10.

[0081] Next, a second embodiment will be described with reference to Figures 7(a) and 7(b). In the first embodiment, the case in which the center of gravity W2 of the outer route L2 and the center of gravity W1 of the inner route L1 of the first member 11 are pressed by a single pressing support 5 was described. In contrast, in the second embodiment, the case in which the center of gravity W3 of the inner route L3 and the center of gravity W4 of the outer route L4 of the first member 11 are pressed by separate pressing supports 5a and 5b will be described. Note that parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted below.

[0082] Figure 7(a) is a schematic top view of the jig 70 and the joint 72 in the second embodiment. Figure 7(b) is a schematic cross-sectional view of the jig 70 and the joint 72 along the line VIIb-VIIb in Figure 7(a). In Figure 7(a), the shape of the upper surface (pressing tip 51) of the pressing supports 5a and 5b located below (towards the back of the paper) the joint 72 is shown by a dashed line.

[0083] The jointed body 72 is formed by friction stir welding a metal first member 11 and a metal second member 12 along an annular inner route L3 and an annular outer route L4. The first member 11 and the second member 12 of the second embodiment are constructed substantially the same as those of the first member 11 and the second member 12 of the first embodiment, although their detailed shapes differ. In the second embodiment, the upper surface of the first member 11 has a recessed fitting portion 11f that is recessed downwards so that substantially the entire second member 12 fits into it, instead of the convex portion 11b of the first embodiment. Furthermore, in the second embodiment, the positioning of the first member 11 and the second member 12 is possible by the recessed fitting portion 11f, so the positioning pin 11e and positioning recess 12a of the first embodiment are absent.

[0084] The outer route L4 is a long rectangle in the left-right direction when viewed vertically, as shown in Figure 7(a). The inner route L3 is located inside the outer route L4 and to the left when viewed vertically, and is formed in a circular shape.

[0085] Since these routes L3 and L4 are formed symmetrically in all directions, the position of the centroid W3 of the surface outlined by the inner route L3 approximately coincides with the position of the valley bottom when the joined body 72 deforms into a concave shape due to thermal contraction during the joining of the inner route L3. Similarly, the position of the centroid W4 of the surface outlined by the outer route L4 approximately coincides with the position of the valley bottom when the joined body 72 deforms into a concave shape due to thermal contraction during the joining of the outer route L4. Furthermore, the final position of the valley bottom when the joined body 72 deforms into a concave shape due to thermal contraction during the joining of both routes L3 and L4 can be approximated by the position of the combined centroid W34 of the centroids W3 and W4.

[0086] The jig 70 of the second embodiment is substantially identical to the jig 1 of the first embodiment, except that it includes two pressing supports 5a and 5b. Although the second clamp 4 is not shown in Figures 7(a) and 7(b), the jig 70 also includes the second clamp 4 (the same applies to Figures 8(a) and 8(b)). Furthermore, each of the pressing supports 5a and 5b is configured identically to the pressing support 5 of the first embodiment.

[0087] The pressing support 5a is positioned directly below the center of gravity W4 and the combined center of gravity W34, and during friction stir welding, it presses the first member 11 at the positions of the center of gravity W4 and the combined center of gravity W34, deforming the first member 11 and the second member 12 into a convex shape. The pressing support 5b is positioned directly below the center of gravity W3, and during friction stir welding, it presses the first member 11 at the position of the center of gravity W3, deforming the first member 11 and the second member 12 into a convex shape.

[0088] As a result, the concave deformation of the joint 72 (first member 11 and second member 12) due to thermal shrinkage during joining of the outer route L4, and the deformation of the joint 72 due to thermal shrinkage during joining of the inner route L3, can be absorbed by the convex deformation of the pressing supports 5a and 5b. As a result, a highly accurate joint 72 can be manufactured.

[0089] Furthermore, in this embodiment, instead of pressing the positions of the centers of gravity W3 and W4 together with a single pressing support, the positions of the centers of gravity W3 and W4 are pressed individually with pressing supports 5a and 5b. This allows the amount of deformation by the pressing supports 5a and 5b to be individually set according to the amount of deformation due to thermal shrinkage at each position of the centers of gravity W3 and W4. As a result, it is easier to bring the amount of deformation after joining closer to zero compared to before joining, thus enabling the manufacture of a more highly accurate joined body 72.

[0090] Furthermore, the amount of deformation due to thermal contraction at the positions of the centers of gravity W3 and W4 is measured in the same way as the amount of deformation due to thermal contraction at the position of the composite center of gravity W12 described in the first embodiment. It is preferable to make the amount of deformation due to the pressing support 5a approximately the same as the amount of pressing deformation obtained by adding springback to the amount of deformation due to thermal contraction at the position of the center of gravity W4. Similarly, it is preferable to set the amount of deformation due to the pressing support 5b approximately the same as the amount of pressing deformation obtained by adding springback to the amount of deformation due to thermal contraction at the position of the center of gravity W3. As a result, it is possible to make it easier to bring the amount of deformation after joining closer to zero compared to before joining, so that a more highly accurate joined body 72 can be manufactured.

[0091] Furthermore, an annular cooling passage 51b is provided inside the pressing tip 51 of the pressing support 5b, formed along the inner route L3. Both ends of this cooling passage 51b open to the outer surface of the pressing tip 51 (for example, the lower side in Figure 7(a)), and cooling liquid passages (not shown) are connected to these openings. This allows friction stir welding to be performed while cooling liquid flows through the cooling passage 51b, which reduces thermal shrinkage during welding and suppresses concave deformation of the joined body 72 due to thermal shrinkage. As a result, the amount of convex deformation caused by the pressing supports 5a and 5b can be reduced.

[0092] In particular, since the cooling passage 51b is formed along the inner route L3, thermal contraction during joining of the inner route L3 can be made less likely, and the concave deformation of the joined body 72 due to such thermal contraction can be further suppressed. Alternatively, such a cooling passage may be provided inside the lifting tip 61 of the lifting support 6 so as to follow the outer route L4. In this case, thermal contraction during joining of the outer route L4 can be made less likely, and the concave deformation of the joined body 72 due to such thermal contraction can be further suppressed.

[0093] Next, a third embodiment will be described with reference to Figure 8(a). In the first embodiment, a case was described in which the first member 11 and the second member 12 are friction stir-welded using two inner routes L1 and outer routes L2. In contrast, the third embodiment will describe a case in which the first member 11 and the second member 12 are friction stir-welded using one route L5. Note that parts identical to those in the first and second embodiments are denoted by the same reference numerals and their descriptions are omitted below.

[0094] Figure 8(a) is a schematic top view of the jig 80 and the joining body 82 in the third embodiment. In Figure 8(a), the shape of the upper surface of the pressing support 5, which is located below the joining body 82 (towards the back of the paper), is shown by a dashed line.

[0095] The joint 82 is formed by friction stir welding a first metal member 11 and a second metal member 12 using only a single annular route L5. The first member 11 and the second member 12 of the third embodiment have different detailed shapes from the first member 11 and the second member 12 of the second embodiment, but are constructed substantially the same. In addition, in the friction stir welding of the third embodiment, the butt joint is formed by stirring while softening the abutting portion between the inner edge of the recessed fitting portion 11f of the first member 11 (see Figure 7(b)) and the outer edge of the second member 12.

[0096] Route L5 has an asymmetrical shape in terms of front, back, left, and right. The position of the centroid W5 of the surface outlined by route L5 can be approximated as the position of the valley bottom when the joint 82 deforms into a concave shape due to thermal contraction during the joining of route L5.

[0097] The jig 80 of the third embodiment is substantially identical to the jig 1 of the first embodiment, except that the arrangement of the pressing support 5 is different. The pressing support 5 of the third embodiment is positioned directly below the center of gravity W5 and presses the first member 11 at the position of the center of gravity W5 during friction stir welding, causing the first member 11 and the second member 12 to deform into a convex shape. This convex deformation by the pressing support 5 can absorb the concave deformation of the joined body 82 (first member 11 and second member 12) due to thermal shrinkage during friction stir welding. As a result, a highly accurate joined body 82 with less deformation due to thermal shrinkage can be manufactured.

[0098] Furthermore, in the joined body 82, the first member 11 and the second member 12 are joined by only one route L5. Compared to the case where they are joined by two routes, the position of the valley bottom when the joined body 82 deforms into a concave shape due to thermal shrinkage is easier to determine, and this position is more likely to coincide with the center of gravity W5. Moreover, since the center of gravity W5 is located at the center of the upper surface of the pressing support 5 when viewed in the vertical direction, the peak of the convex deformation caused by the pressing support 5 and the valley bottom of the concave deformation due to thermal shrinkage are more likely to coincide. As a result, the amount of deformation after joining compared to before joining can be brought closer to zero, making it possible to manufacture a more highly accurate joined body 82.

[0099] Next, a fourth embodiment will be described with reference to Figure 8(b). In the first embodiment, the case in which the pressing support 5 presses on three locations of the first member 11, namely the composite center of gravity W12, center of gravity W1, and center of gravity W2, was described. In contrast, in the fourth embodiment, the case in which the pressing support 5 presses on only the location of the composite center of gravity W67 of the first member 11 will be described. Note that parts identical to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted below.

[0100] Figure 8(b) is a schematic top view of the jig 90 and the joining body 92 in the fourth embodiment. In Figure 8(b), the shape of the upper surface of the pressing support 5, located below the joining body 92 (towards the back of the paper), is shown by a dashed line.

[0101] The jointed body 92 is formed by friction stir welding a first metal member 11 and a second metal member 12 along an annular inner route L6 and an annular outer route L7. The first member 11 and the second member 12 of the fourth embodiment are constructed substantially the same as those of the first member 11 and the second member 12 of the first embodiment, although their detailed shapes differ.

[0102] The inner route L6 is positioned inside the outer route L7. The position of the combined centroid W67, which is the centroid W6 of the surface outlined by the inner route L6 and the centroid W7 of the surface outlined by the outer route L7, can be approximated as the final valley bottom position when the joined body 92 deforms into a concave shape due to thermal contraction during the joining of both routes L6 and L7.

[0103] The jig 90 of the fourth embodiment is configured substantially the same as the jig 1 of the first embodiment, except that the arrangement of the pressing support 5 is different. The pressing support 5 of the fourth embodiment is positioned directly below the composite center of gravity W67. During friction stir welding, this pressing support 5 presses the first member 11 at the position of the composite center of gravity W67, deforming the first member 11 and the second member 12 into a convex shape. As a result, in the fourth embodiment, as in the first embodiment, both the deformation during joining of each route L6 and L7 can be efficiently absorbed by the deformation of the pressing support 5, so that a highly accurate joined body 92 with less deformation due to thermal shrinkage can be manufactured.

[0104] Furthermore, the pressing support 5 in the fourth embodiment is not positioned directly below the centers of gravity W6 and W7, and does not press the first member 11 at the positions of the centers of gravity W6 and W7. Therefore, the pressing support 5 makes it easier for the first member 11 and the second member 12 to deform so that the position of the combined center of gravity W67 is precisely at the peak (or near the peak). As a result, deformation due to thermal shrinkage can be further absorbed by the deformation caused by the pressing support 5, making it possible to manufacture a joint 92 with even higher precision.

[0105] Although the present invention has been described above based on embodiments, it can be easily inferred that the present invention is not limited in any way to the above embodiments, and that various improvements and modifications are possible without departing from the spirit of the present invention. For example, the shapes and arrangements of the first member 11, the second member 12, the first clamp 3, the second clamp 4, and each of the routes L1 to L7 in the above embodiments are illustrative examples and may be changed as appropriate. Also, the joints 10, 72, 82, and 92 are not limited to liquid cooling jackets, but may be various articles formed by friction stir welding a metal first member and a metal second member.

[0106] In the above embodiment, the case in which each part of the jig 1,70,80,90 is driven by hydraulics or pneumatics has been described, but for example, each part may be configured to be driven only by hydraulics or only by pneumatics. Also, at least a part of each part of the jig 1,70,80,90 may be configured to be driven by electricity or the like.

[0107] In the above embodiment, the case in which the pressing supports 5, 5a, and 5b are equipped with a first lifting section 52 and a second lifting section 53 has been described, but the invention is not necessarily limited to this. For example, the first lifting section 52 may be omitted, and the pressing supports 5, 5a, and 5b may raise and lower the pressing tip 51 using only the second lifting section 53 (one lifting section). In this case, the pressing supports 5, 5a, and 5b may be arranged so that the pressing tip 51 contacts the first member 11 at the lower limit position, or the amount of lifting by the second lifting section 53 may be set considering the gap from the pressing tip 51 at the lower limit position to the first member 11.

[0108] In the above embodiment, the case in which the pressing lock part 52e and the lifting lock part 62e are built into the first lifting part 52 and the lifting part 62 has been described, but the pressing lock part 52e and the lifting lock part 62e may be provided on the outside of the first lifting part 52 and the lifting part 62. Furthermore, the pressing lock part 52e and the lifting lock part 62e are not limited to the collet chuck exemplified in the above embodiment, as long as they are capable of locking the lifting and lowering of the pressing tip part 51 and the lifting tip part 61 by the first lifting part 52 and the lifting part 62. For example, the first lifting part 52 and the lifting part 62 may be hydraulic cylinders, and the extension and retraction of the hydraulic cylinders may be locked by stopping the supply and discharge of hydraulic pressure from the hydraulic cylinders, thereby locking the lifting and lowering of the pressing tip part 51 and the lifting tip part 61.

[0109] The first lifting section 52 and the lifting section 62 are not limited to those exemplified in the above embodiment or hydraulic cylinders, as long as they raise and lower the pressing tip 51 and the lifting tip 61 relative to the table 2. For example, the first lifting section 52 and the lifting section 62 may be configured such that, when unloaded, the rods 52b and 62b are pushed out to their maximum extent by an elastic body such as a coil spring, and the pressing tip 51 and the lifting tip 61 are lowered by the compression of the elastic body. The elastic force of the elastic body is set to be weak so that the elastic body is compressed by the weight when the first member 11 is placed on the pressing tip 51 and the lifting tip 61, so that the pressing tip 51 and the lifting tip 61 do not press the first member 11 but rather make contact with it.

[0110] In the first embodiment described above, a case was explained in which one pressing support 5 presses on three locations on the first member 11: the position of the center of gravity W1, the position of the center of gravity W2, and the position of the combined center of gravity W12. However, the invention is not limited to this. The position on the first member 11 pressed by one pressing support 5 may be only one or only two of these three locations. Alternatively, two pressing supports 5 may be used to press on the three locations, or two of the three locations may be pressed individually. Alternatively, three pressing supports 5 may be used to press on the three locations individually.

[0111] Furthermore, the position where the pressing support 5 presses the first member 11 does not necessarily have to be at the center of gravity W1, W2 or the combined center of gravity W12, but at least it should be inside the outer route L1. Note that pressing the first member 11 inside the outer route L1 with the pressing support 5 includes not only pressing the inside but also pressing the outside of the outer route L1.

[0112] For example, the position of the valley bottom due to the concave deformation when friction stir welding is performed without pressing by the pressing support 5 can be determined by computer simulation such as CAE analysis, or by measurement after the actual welding. The first member 11 at the position of the valley bottom determined in this way can then be pressed with the pressing support 5. This allows for more effective absorption of the concave deformation of the joined body 10 due to thermal shrinkage compared to pressing at the positions of the centers of gravity W1, W2 or the combined center of gravity W12.

[0113] In the first embodiment described above, the case in which the first member 11 and the second member 12 are friction stir-welded along the inner route L1 and then friction stir-welded along the outer route L2 was explained. However, friction stir-welding may be performed in the order of outer route L2 followed by inner route L1. In this case, the outside of the groove 11a (the outer edge side of the second member 12) can be joined along the outer route L2 without any strain caused by the joining of the inner route L1 occurring in the first member 11 or the second member 12. This improves the joining quality of the outer route L2, making it less likely for a flow path to be created in which the coolant in the groove 11a will leak out of the joined body 10.

[0114] In the above embodiment, the case where the inner routes L1, L3, L6 and the outer routes L2, L4, L7 and route L5 are all continuous annular structures is described, but it is not necessarily limited to this. For example, these annular routes L1 to L7 may be provided intermittently. Also, the friction stir welding of the inner routes L1, L3, L6 and the outer routes L2, L4, L7 may be butt joints, not just lap joints. The friction stir welding of route L5 may be lap joints, not just butt joints.

[0115] In the above embodiment, the case in which the first member 11 is deformed by the pressing support 5 and then the second member 12 is pressed against the first member 11 with the second clamp 4 was described, but the embodiment is not necessarily limited to this. For example, the second member 12 may be pressed against the first member 11 with the second clamp 4, and then the first member 11 and the second member 12 may be deformed by the pressing support 5 (the deformation step may be performed after the pressing step). Furthermore, the case is not limited to the case in which the second member 12 is placed on the first member 11 before deformation by the pressing support 5, but the second member 12 may be placed on the first member 11 after deformation. [Explanation of symbols]

[0116] 1, 70, 80, 90 jigs 10,72,82,92 zygote 11. First Member 12 Second Member 2 tables 3. First clamp 4. Second clamp 5,5a,5b Pressure support 6. Lifting support L1, L3, L6 Inner Route (Route) L2, L4, L7 outer routes (routes) L5 Route W1~W7 Center of gravity W12,W34,W67 Combined center of gravity

Claims

1. A jig for fixing a first metal member and a second metal member when forming a joint by friction stir welding along an annular route, A table supporting the first member, A first clamp that holds the first member between itself and the table, The first member is provided with a second clamp that presses the second member toward the table, A jig characterized by comprising a pressing support that presses the first member from the table side inside the annular route.

2. The jig according to claim 1, characterized in that the pressing support presses the first member from the table side at the position of the center of gravity of the surface outlined by the annular route.

3. The jig according to claim 2, characterized in that the aforementioned route has an asymmetrical shape.

4. The aforementioned route includes an annular outer route and an annular inner route provided inside the outer route. The jig according to claim 2, characterized in that the pressing support is positioned to press the position of the combined center of gravity of the surface outlined by the outer route and the center of gravity of the surface outlined by the inner route.

5. The jig according to claim 4, characterized in that the pressing support is positioned to press the position of the combined center of gravity and to press the position of the center of gravity of the surface outlined by the outer route.

6. The aforementioned route includes an annular outer route and an annular inner route provided inside the outer route. The jig according to claim 2, characterized in that the pressing support is positioned to press the position of the center of gravity of the surface outlined by the outer route, and also to press the position of the center of gravity of the surface outlined by the inner route.

7. A method for manufacturing a joined body by friction stir welding the first member and the second member using the jig described in any one of claims 1 to 6, A clamping step in which the first member is clamped between the table and the first clamp, After the clamping step, a deformation step is performed in which the first member is pressed and deformed by the pressing support, A pressing step in which the second clamp presses the second member against the first member toward the table side, A method for manufacturing a joined body, comprising a joining step of friction stir joining the first member and the second member along the annular route, after the deformation step and the pressing step.

Images