Friction stir spot welding method for metal parts

Abstract

To provide a friction stir point joining method for a metallic component which is less prone to defects such as misalignment of a foil material and damage to the foil material.SOLUTION: In a friction stir point joining method for a metallic component that joins a metallic foil material 30 and a plate 20, the plate 20 is placed on the foil material 30 folded and laminated at least 5 times. While a friction stir joining tool 10 is rotated in the state that the plate 20 is fixed by a jig 40, a tip 10T of the friction stir joining tool 10 is inserted from the plate 20 side. As a result, a part of the plate 20 is pressed against the foil material 30 to join the foil material 30 and the plate 20.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a friction stir spot joining method for metal parts, in which metal plate and foil materials, such as aluminum alloys and copper alloys, are joined together by friction stir spot joining. [Background technology]

[0002] Known products and manufacturing methods for friction stir spot welding of metal foil and metal plate include those using aluminum alloys and copper alloys, as disclosed in Patent Document 1. Many products using these metal foils are manufactured by joining a metal plate to a bundling plate made of multiple layers of individually cut metal foil, as disclosed in Patent Documents 2 and 3.

[0003] Another method for laminating metal foils into multiple layers is to join a single sheet of metal foil by spirally winding it, which is known as a method for manufacturing electrical components such as capacitors. Figure 10 shows a schematic diagram of a metal part made using the conventional friction stir spot welding method, Figure 11 shows a schematic diagram of the metal foil material used in the conventional friction stir spot welding method, and Figure 12 shows a schematic diagram of a metal part joined using the conventional friction stir spot welding method. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-109230 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-11675 [Patent Document 3] Patent No. 6252359 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the case of a focusing plate 150 in which foil material 130 cut one by one is stacked in multiple layers as shown in Figures 10 and 11, when the friction stir welding tool 110 is inserted, there was a problem that only the foil material 130 sandwiched between the two plate materials 120, 121 rotates, becomes misaligned, or is damaged.

[0006] In addition, when clamping (fixing) multi-layered foil material, if the foil material is fixed under sufficient pressure, the foil material made of relatively soft aluminum alloy or copper alloy will stretch, reducing its cross-sectional area and its strength.

[0007] In particular, when foil material is spirally laminated, the foil material at the folded end is difficult to adhere to, and the foil material must be fixed with high pressure. However, even when the foil material is pressed with high pressure, the foil material at the top of the laminate may stretch, and the lower side of the laminate may not be fixed or adhered.

[0008] If the foil material is joined with insufficient pressure, the foil material may rotate, become misaligned, or be damaged.

[0009] In addition, conventional joining methods require the insertion of a friction stir welding tool into the lowest layer of a bundling plate made of multiple layers of foil material, which means that the bundling plate can only be joined in a shape sandwiched between plate materials, resulting in a problem of large part sizes.

[0010] Therefore, an object of the present invention is to provide a method for friction stir spot joining of metal parts such as aluminum or copper that is less likely to cause problems such as foil material misalignment or damage during friction stir spot joining.Another object is to produce a simple shape consisting of multi-layered foil material and a plate material placed on top of it. [Means for solving the problem]

[0011] In the friction stir spot joining method for metal parts of the present invention, a plate material is placed above foil material that has been folded at least five times and then fixed with a jig. In this state, a friction stir welding tool is rotated while the tip of the friction stir welding tool is inserted from the plate material side. The foil and plate materials are joined by pressing a portion of the plate material against the foil material by friction stir welding.

[0012] It is also possible to join foil and plate materials by inserting the tip of the friction stir welding tool into the plate material within a range of 20 mm from the folded end of the foil material. The insertion depth of the tip of the friction stir welding tool is preferably smaller than the sum of the thicknesses of the foil and plate materials. [Effects of the Invention]

[0013] In the friction stir spot joining method for metal parts of the present invention, when joining foil material using the friction stir spot joining method, the foil material is given a folded (folded back) structure, which makes it less likely that problems such as the foil material shifting or being damaged during friction stir spot joining will occur.

[0014] Furthermore, by not inserting the friction stir welding tool into the bottom layer of the laminated foil material, it is possible to produce a simple shape consisting of multiple laminated foil materials and a plate material placed on top of it.In addition, because the folded (folded) structure of the foil material is integrated, the cycle time of the entire molding process, including the joining process, is shorter than when multiple foil materials are stacked and joined to a plate material. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing the overall configuration used when joining metal parts. [Figure 2] FIG. 2 is a schematic diagram of a foil material 30 used when joining metal parts. [Figure 3] 1 is a schematic diagram of a first step in the method for joining metal components of the present invention. [Figure 4] FIG. 2 is a schematic diagram of a second step in the method for joining metal components of the present invention. [Figure 5]FIG. 2 is a schematic diagram of a third step in the method for joining metal components of the present invention. [Figure 6] FIG. 4 is a schematic diagram of a fourth step in the method for joining metal components of the present invention. [Figure 7] FIG. 1 is a schematic cross-sectional view of a metal part 50 manufactured using the joining method of the present invention. [Figure 8] 1 shows an arrangement pattern (first embodiment) of foil materials when joined by the joining method of the present invention. [Figure 9] 10 shows an arrangement pattern (second embodiment) of foil materials when joined by the joining method of the present invention. [Figure 10] FIG. 1 is a schematic diagram illustrating a conventional friction stir spot joining method. [Figure 11] FIG. 1 is a schematic diagram of a foil material 130 used in a conventional friction stir spot joining method. [Figure 12] FIG. 1 is a schematic diagram of a metal part 150 joined by a conventional friction stir spot welding method. DETAILED DESCRIPTION OF THE INVENTION

[0016] An embodiment of the method for friction stir spot welding of metal parts of the present invention will be described with reference to the drawings. Fig. 1 shows the components of the method for friction stir spot welding of metal parts of the present invention, and Fig. 2 shows a schematic diagram of a folded foil material 30 used in the method for friction stir spot welding of metal parts of the present invention. In the method for friction stir spot welding of metal parts of the present invention, the metal part is composed of foil material 20 and plate material 30 as shown in Fig. 1, and is placed below the friction stir welding tool 10 used during friction stir spot welding in a stacked configuration with foil material 20 as the upper layer and plate material 30 as the lower layer. In this case, the foil material 20 used during friction stir spot welding is stacked by folding it at least five times, as shown in Fig. 2.

[0017] 3 to 6 are schematic diagrams showing the first to fourth steps of the friction stir spot joining method for metal parts of the present invention. First, a sheet material 20 is stacked on top of a foil material 30 that will become the metal part, and then, as shown in Fig. 3, both the foil material 30 and the sheet material 20 are fixed from above with a holding jig 40. At this time, it is preferable to align an end 30H of the foil material 30 with an end 20H of the sheet material 20, as shown in Fig. 3 (first step: Fig. 3). A friction stir welding tool 10 is attached to a joining device (not shown) in the vacant position of the holding jig 40, and a tip 10T of the friction stir welding tool 10 is brought close to a predetermined position.

[0018] Next, while rotating the friction stir welding tool 10 at a predetermined rotation speed (rotation direction R), the tip 10T of the friction stir welding tool 10 is inserted into the plate material 20 (second step: FIG. 4). A portion of the plate material 20 is melted and stirred by the tip 10T of the friction stir welding tool 10 rotating at high speed. At the same time, a portion of the molten plate material 20 moves around the tip 10T of the friction stir welding tool 10 and toward the foil material 20. Ultimately, the tip 10T of the friction stir welding tool 10 is inserted into the foil material 20 (third step: FIG. 5). The position of the tip 10T of the friction stir welding tool 10 is set to a position where it does not penetrate through the foil material 20, and the position of the tip 10T of the friction stir welding tool 10 is kept within the thickness of the foil material 20.

[0019] After the tip 10T of the friction stir welding tool 10 reaches its deepest position, the friction stir welding tool 10 is moved upward and the tip 10T of the friction stir welding tool 10 returns to a predetermined position, completing the joining of the foil material 30 and the plate material 20 and producing a metal part 50 (fourth step: FIG. 6). FIG. 7 shows a schematic cross-sectional view of a metal part 50 manufactured using the friction stir spot welding method for metal parts of the present invention. As shown in FIG. 7, the metal part 50 retains traces of the shape of the friction stir welding tool used during friction stir spot welding, and a recess in the shape of the tip of the friction stir welding tool 1 and a bank-shaped protrusion around it are formed.

[0020] Next, the arrangement of foil materials 31, 32 during joining by the friction stir spot joining method of the present invention is shown in FIG. 8 (first embodiment) and FIG. 9 (second embodiment). In the first embodiment, a sheet material 21 is stacked above a foil material 31, which is a component of a metal part, as in the case shown in FIG. 3. As shown in FIG. 8, the foil material 31 and the sheet material 21 are both fixed from above by a holding jig 41. As shown in FIG. 8, the end 31H of the foil material 31 and the end 21H of the sheet material 21 are misaligned. The end 21H of the sheet material 21 is located directly below the holding jig 41, but the end 31H of the foil material 31 is located slightly inward (on the left side of the drawing) from directly below the edge of the holding jig 41. In this case, the joining point by the friction stir welding tool 11 is preferably within a distance d1 starting from the end 31H of the foil material 31, as shown in FIG. 8.

[0021] In the second embodiment, similar to the first embodiment shown in FIG. 8, a sheet material 22 is stacked on top of a foil material 32, which is a component of a metal part. As shown in FIG. 9, the foil material 32 and the sheet material 22 are both fixed from above by a holding jig 42. In this case, as shown in FIG. 9, the end 32H of the foil material 32 and the end 22H of the sheet material 22 are misaligned. The end 22H of the sheet material 22 is located directly below the holding jig 42, but the end 32H of the foil material 32 is located slightly outside (to the right of the drawing) the edge of the holding jig 42. In this case, too, the welding point using the friction stir welding tool 12 is preferably within a distance d2 starting from the end 32H of the foil material 32, as shown in FIG. 9. In the present invention, a "foil material (metal foil)" refers to a material having a thickness of 0.30 mm or less, and a "sheet material (metal plate)" refers to a material having a thickness exceeding 0.30 mm. [Explanation of symbols]

[0022] 10,11,12 Friction stir welding tools 20,21,22 Plate material 30,31,32 Foil material 40, 41, 42 Holding jig 50 Metal Parts 10T Friction Stir Welding Tool Tip 20H, 21H, 22H End of plate material 30H, 31H, 32H End of foil material d1, d2 Distance from the edge of the foil material

Claims

1. A friction stir spot joining method for metal parts that joins metal foil material and plate material, characterized in that the plate material is placed above the foil material that has been folded back and forth at least five times, and while rotating a friction stir welding tool with the plate material fixed with a jig, the tip of the friction stir welding tool is inserted from the plate material side to press a portion of the plate material against the foil material, thereby joining the foil material and the plate material.

2. 2. The method for friction stir spot joining of metal parts according to claim 1, characterized in that the foil material and the plate material are joined by inserting the tip of the friction stir welding tool into the plate material within a range of 20 mm from the end of the foil material.

3. 3. The method for friction stir spot joining of metal parts according to claim 1, wherein the insertion depth of the tip of the friction stir welding tool is smaller than the sum of the thicknesses of the foil material and the plate material.

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