Method for manufacturing joints for thin strip metal sheets
By cutting and matching the edges of strip-shaped metal sheets and welding at specific midpoints, the method enhances tensile and bending strengths while simplifying alignment, addressing the limitations of conventional spot welding.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MURATA WELDING LAB INC
- Filing Date
- 2024-10-24
- Publication Date
- 2026-05-12
AI Technical Summary
Conventional spot welding methods for joining strip-shaped metal thin plates result in low bending and tensile strengths due to the formation of steps or gaps at the welded edges, and require complex alignment processes.
A method involving cutting the edges of strip-shaped metal sheets into specific shapes that match each other, with spot welding performed at predetermined midpoints, followed by rolling to flatten the welded areas, enhancing tensile and bending strengths.
Improves tensile and bending strengths by distributing stress across uncut sections, allowing for accurate alignment without additional alignment tools and enabling multiple spot welds in narrow carriers.
Smart Images
Figure 2026076520000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for manufacturing a joining joint that joins strip-shaped metal thin plates by spot welding.
Background Art
[0002] Conventionally, in order to extend strip-shaped metal thin plates such as connectors for electronic components, lead frames for semiconductors, and hoop materials for capacitors, the edge of one strip-shaped metal thin plate and the edge of the other strip-shaped metal thin plate are joined by welding. As welding methods, lap welding in which the edges are overlapped and spot welded, and butt welding in which the edges cut in parallel are butted against each other are used (for example, Patent Document 1, etc.).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, lap welding is not preferable because a step is formed. Further, whether the edges are overlapped and welded or the edges cut in parallel are butted and welded, in the case of spot welding, the bending strength and tensile strength are low.
[0005] Therefore, a main object of the present invention is to provide a method for manufacturing a joining joint of strip-shaped metal thin plates that can improve the bending strength and tensile strength even in the case of joining strip-shaped metal thin plates by spot welding as compared with the above conventional welding methods.
Means for Solving the Problems
[0006] To achieve the above objective, the method for manufacturing a joint for strip-shaped metal sheets according to the present invention includes the steps of: cutting the edge of a first strip-shaped metal sheet; cutting the edge of a second strip-shaped metal sheet; and spot welding the cut edge of the first strip-shaped metal sheet and the cut edge of the second strip-shaped metal sheet, wherein the shape of the cut edge of the first strip-shaped metal sheet is a first edge extending from one side edge of the first strip-shaped metal sheet to a first midpoint in the width direction, and The strip of metal has an intermediate edge extending from a first widthwise midpoint to a second widthwise midpoint located a predetermined distance along the length of the first strip of metal, and a second end edge extending from the second widthwise midpoint to the other side edge of the first strip of metal, wherein the cut end shape of the second strip of metal has a shape that matches the cut end shape of the first strip of metal, and the spot welding process involves spot welding the first widthwise midpoint and the second widthwise midpoint.
[0007] In one embodiment of the present invention, the first strip-shaped metal sheet and the second strip-shaped metal sheet are carriers in which pilot holes are formed at predetermined intervals, and the intermediate edge crosses the pilot holes, with the first midpoint in the width direction and the second midpoint in the width direction each located between adjacent pilot holes. [Effects of the Invention]
[0008] According to the present invention, since the section from the first midpoint in the width direction to the other side edge is not cut, and the section from the second midpoint in the width direction to the one side edge is also not cut, the tensile strength and bending strength are improved. [Brief explanation of the drawing]
[0009] [Figure 1] This is a process diagram illustrating one embodiment of the method for manufacturing a joining joint for strip-shaped metal sheets according to the present invention. [Figure 2] This is a plan view showing another embodiment of a joint manufactured by the manufacturing method of the present invention. [Figure 3] This is a process diagram illustrating another embodiment of the method for manufacturing a joining joint for strip-shaped metal sheets according to the present invention. [Figure 4] This diagram illustrates a conventional butt jointing process using spot welding. Figure 4(a) shows the joint before butt joining, and Figure 4(b) shows the joint after butt joining and spot welding. [Modes for carrying out the invention]
[0010] One embodiment of the present invention will be described below with reference to the drawings. Note that identical or similar components, including those in the prior art, are denoted by the same reference numerals.
[0011] Figure 1(a) shows a first strip of metal sheet 1 and a second strip of metal sheet 2 to be joined. The first strip of metal sheet 1 and the second strip of metal sheet 2 each have a pair of parallel side edges 1a, 1b, 2a, and 2b.
[0012] The edges of the first strip-shaped metal sheet 1 and the second strip-shaped metal sheet 2 are cut at the positions indicated by the dashed lines in Figure 1(b), and after cutting, they have the edge shape shown in Figure 1(c). The edges of the first strip-shaped metal sheet 1 and the second strip-shaped metal sheet 2 can be cut using a cutting die shaped like the dashed line in Figure 1(b).
[0013] Referring to Figure 1(c), the cut edge shape of the first strip-shaped metal sheet 1 has a first edge 1d extending from one side edge 1a of the first strip-shaped metal sheet 1 to a first widthwise midpoint 1c, a first intermediate edge 1f extending from the first widthwise midpoint 1c to a second widthwise midpoint 1e located a predetermined distance along the length of the first strip-shaped metal sheet 1, and a second edge 1g extending from the second widthwise midpoint 1e to the other side edge 1b of the first strip-shaped metal sheet 1.
[0014] The cut edge shape of the second strip-shaped metal sheet 2 matches the cut edge shape of the first strip-shaped metal sheet 1. That is, the shape is such that when the cut edge of the first strip-shaped metal sheet 1 and the cut edge of the second strip-shaped metal sheet 2 are butted together, there is no displacement or gap in the width direction and length direction. Both the cut edge of the first strip-shaped metal sheet 1 and the cut edge of the second strip-shaped metal sheet 2 are stepped in shape, each having a projection extending in the length direction.
[0015] Therefore, the cut edge shape of the second strip-shaped metal sheet 2 has a third edge 2d extending from one side edge 2a of the second strip-shaped metal sheet 2 to a third widthwise midpoint 2c, a second intermediate edge 2f extending from the third widthwise midpoint 2c to a fourth widthwise midpoint 2e located a predetermined distance along the length of the second strip-shaped metal sheet 2, and a fourth edge 2g extending from the fourth widthwise midpoint 2e to the other side edge 2b of the second strip-shaped metal sheet 2, wherein the third edge 2d coincides with the first edge 1d, the second intermediate edge 2f coincides with the first intermediate edge 1f, and the fourth edge 2g coincides with the second edge 1g. The third edge 2d is the same length as the first edge 1d, the second intermediate edge 2f is the same length as the first intermediate edge 1f, and the fourth edge 2g is the same length as the second edge 1g. In the illustrated example, the first edge 1d, the second edge 1g, the third edge 2d, and the fourth edge 2g are all the same length.
[0016] As shown in the example in Figure 1, it is preferable that the first intermediate edge 1f extends parallel to the side edge 1b and the second intermediate edge 2f extends parallel to the side edge 2a, but as shown in Figure 2, they may also extend diagonally to the side edges 1b and 2a. Furthermore, it is preferable that the first end edge 1d, the second end edge 1g, the third end edge 2d, and the fourth end edge 2g extend perpendicular to the side edges 1a and 2b, as shown in the example in Figure 1, but as shown in Figure 2, they may also extend diagonally to the side edges 1a, 1b, 2a, and 2b.
[0017] Referring to Figure 1(d), when the edges of the first strip-shaped metal sheet 1 and the second strip-shaped metal sheet 2, which have the above edge shape, are brought together, the first widthwise midpoint 1c is brought together with the third widthwise midpoint 2c, the second widthwise midpoint 1e is brought together with the fourth widthwise midpoint 2e, the first edge 1d and the third edge 2d are brought together in the lengthwise direction, the second edge 1g and the fourth edge 2g are brought together in the lengthwise direction, and the first intermediate edge 1f and the second intermediate edge 2f are brought together in contact in the widthwise direction.
[0018] With the parts butted together in this manner, as shown in Figure 1(e), spot welding (S1) is performed around the first midpoint 1c in the width direction, and spot welding (S2) is performed around the second midpoint 1e in the width direction. Specifically, the tip of the electrode rod of the spot welding device (TIG welding device) is positioned on the first midpoint 1c in the width direction and spot welding is performed, and then the tip of the electrode rod is positioned on the second midpoint 1e in the width direction and spot welding is performed.
[0019] As described above, the spot welds are formed around the first midpoint 1c in the width direction, including at least a portion of the first edge 1d and the third edge 2d, and a portion of the first intermediate edge 1f and the second intermediate edge 2f, in a spot-like (circular) weld. The spot welds are also formed around the second midpoint 1e in the width direction, including at least a portion of the second edge 1g and the fourth edge 2g, and a portion of the first intermediate edge 1f and the second intermediate edge 2f. After spot welding, the welded areas are rolled with rolling rollers to flatten the bulges at the welded areas (S1, S2).
[0020] As described above, when a tensile force F is applied to the strip-shaped metal sheet joint, as shown in Figure 1(e), the tensile stress can be received by the uncut portions 1h and 2h, thus reducing the tensile stress load on the welded area. Therefore, the strength against tensile stress is improved compared to conventional spot welding of butt welding as shown in Figure 4. For the same reason, the strength against bending stress due to deflection is also improved compared to the conventional joint shown in Figure 4. In the conventional joint in Figure 4, all tensile and bending stresses are applied to the welded portions S3 and S4, resulting in lower strength than the joint manufactured according to the present invention.
[0021] Also, when the edges to be abutted are parallel and straight as in the prior art, a jig or the like for aligning the positions in the width direction of the strip-shaped metal thin plate is separately required during abutment. However, according to the present invention, since the edge shapes during abutment are different and match, accurate alignment in the width direction can be achieved simply by aligning the edges.
[0022] FIG. 3 shows a welding process of a welding method according to another embodiment of the present invention. In the embodiment of FIG. 3, the shapes of the strip-shaped metal thin plates 1 and 2 to be joined are different from those shown in FIG. 1. The strip-shaped metal thin plates 1 and 2 shown in FIG. 3 are carriers of connector terminals. The carrier is a portion that connects electrical connection terminals 3 such as connectors in a chain (series) form, and pilot holes 4 are formed therein. The pilot holes 4 are holes provided in the carrier portion for positioning and guiding the terminals during pressing and crimping.
[0023] As can be seen from FIGS. 3(b) and (c), the first intermediate edge 1f crosses the pilot hole 4, and the first intermediate point 1c and the second intermediate point 1e in the width direction are respectively located between adjacent pilot holes 4 and 4. Similarly, the ends of the respective strip-shaped metal thin plates 1 and 2 are cut so that the second intermediate edge 2f crosses the pilot hole 4, and the third intermediate point 2c and the fourth intermediate point 2e in the width direction are respectively located between adjacent pilot holes 4 and 4.
[0024] Carriers of this type of electrical and electronic components are generally about several millimeters (less than 1 cm). In such a narrow width case, in the butt joint of the conventionally parallel cut edges, the melting width of spot welding occupies more than half of the width dimension of the carrier, and in many cases, spot welding can be performed only at one place in the butt joint. However, in such a case, according to the present invention, two spot weldings (S1, S2) can be performed at the butt joint, so the tensile strength is improved.
[0025] The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
Description of Reference Numerals
[0026] 1. First strip of thin metal sheet 1a side edge 1b Side edge 1c First width midpoint 1d First edge 1e Second width midpoint 1st floor First intermediate edge 1g second edge 2. Second strip of thin metal sheet 2a side edge 2b Side edge 2c Third width midpoint 2d third edge 2e Fourth width midpoint 2f Second Intermediate Edge 2g Fourth edge
Claims
1. The first step is to cut the edges of the strip-shaped metal sheet, The second step is to cut the edges of the strip-shaped metal sheet, The process includes spot welding the cut edge of the first strip of thin metal sheet to the cut edge of the second strip of thin metal sheet, The cut edge shape of the first strip-shaped metal sheet has a first edge extending from one side edge of the first strip-shaped metal sheet to a first midpoint in the width direction, an intermediate edge extending from the first midpoint in the width direction to a second midpoint in the width direction, which is a predetermined distance along the length of the first strip-shaped metal sheet, and a second edge extending from the second midpoint in the width direction to the other side edge of the first strip-shaped metal sheet. The cut edge shape of the second strip-shaped metal sheet has a shape that matches the cut edge shape of the first strip-shaped metal sheet. The aforementioned spot welding process involves spot welding centered on the first midpoint in the width direction and spot welding centered on the second midpoint in the width direction. A method for manufacturing joints for connecting strip-shaped metal sheets.
2. The first strip-shaped metal sheet and the second strip-shaped metal sheet are carriers in which pilot holes are formed at predetermined intervals. The intermediate edge crosses the pilot hole, and the first widthwise midpoint and the second widthwise midpoint are located between adjacent pilot holes. A method for manufacturing a joint for connecting strip-shaped metal sheets as described in claim 1.