JP2016022509A - Resistance welding method and resistance welding structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resistance welding method and a resistance welding structure capable of easily performing firm resistance welding even for a plate material having a high electrical conductivity when members to be welded arranged in a row and plate materials which are brought into contact with the members to be welded are subjected to resistance welding while leaving a gap between two sheets of the plate materials in the row direction.SOLUTION: A plurality of plate materials 2, 3 are provided so as to have a rectangular shape and the respective plate materials are brought into contact with respective members 1 to be welded and are arranged respectively while leaving a predetermined gap S in the row direction Y, and one or more projections 5 which are respectively projected toward welding portions are formed on both end parts in the row direction of the plate material opposite to the welding portions 1a of the members to be welded. Each of a pair of welding electrodes 10, 11 is brought into contact with an outer surface of the side opposite to the member to be welded on the plate material, the pair of welding electrodes are separated and arranged in the row direction of the plate material, electricity is conducted between the welding electrodes and each of two sheets of plate materials is subjected to projection resistance welding onto the welding portion of each of members to be welded.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resistance welding method and a resistance welding structure in which a plurality of members to be welded are resistance-welded to a plate material, and each member to be welded is electrically connected.

  Conventionally, a plurality of members to be welded are arranged in a row, resistance welded to a plate material, and electrically connected to each other, and at least two cells (members to be welded) are arranged, and a lead plate (terminal plate) that covers the cells and an electric An assembled battery (battery pack) is known to be connected. Here, resistance welding is a method in which a pair of electrodes are placed on a metal material, a large current is passed for a short time while applying pressure, a resistance heat generation of the metal is utilized, a nugget (alloy layer) is generated and melt-connected. It is.

  As an example, each lead plate is resistance-welded to the second cell with a predetermined gap between the end of the first lead plate and the end of the second lead plate, and the end of the first lead plate Between the first and second cells, a resistance welded portion of one of the positive and negative electrodes is formed, and between the end of the second lead plate and the second cell, the positive and negative electrodes An assembled battery in which a resistance welded portion formed by the other electrode is formed (for example, Patent Document 1). In this assembled battery, the welding current A passes from the positive welding electrode 61 through the second lead plate 53 with the first lead plate 52 and the second lead plate 53B having a predetermined gap as shown in FIG. The electrode 51a of the battery 51 is passed through the first lead plate 52 toward the negative welding electrode 60, and a nugget 8 due to resistance heat generation is generated between the lead plates 52 and 53 and the electrode 51a and resistance welding is performed. The lead plates 52 and 53 of this assembled battery are made of nickel-plated iron.

  By the way, in battery packs such as lithium ion batteries, in recent years, higher output has been demanded, and the material of the terminal plate (lead plate) is made of nickel (Ni) from the above-mentioned iron, and further has higher electrical conductivity and electric resistance. There is a tendency to shift to low copper (Cu) or copper alloy.

Japanese Patent No. 4965753

  However, when a plurality of batteries are resistance-welded to a copper or copper alloy terminal plate (plate material), as shown in FIG. 5, when a pair of welding electrodes 60, 61 are pressed against each other and energized, the welding electrode 60 (61) The currents A2 and A3 that diffuse from the terminal plate 52 (53) to the iron electrode 51a of the battery 51 through the terminal plate 52 (53) due to the high conductivity of copper are large. Therefore, it is assumed that it decreases and becomes smaller accordingly. In addition, due to the high thermal conductivity of copper, it is assumed that the heat generated at the welded part tends to escape in the peripheral direction of the terminal plate 52 (53) and thus decreases. This is not a problem when using a terminal plate with a relatively low electrical conductivity or thermal conductivity such as conventional iron. In this case, it is sufficient if high energy (high current) is not applied. Can not be welded.

  On the other hand, when high energy is applied, thermal damage to the battery is large, and there is a possibility that a hole is opened in the welded part due to deterioration of the battery case and overflow of the welded part.

  The present invention is a plate material having a high conductivity when resistance welding is performed on a member to be welded in a row and a plate material brought into contact therewith with a gap in the row direction between two plate materials. Another object of the present invention is to provide a resistance welding method and a resistance welding structure capable of easily performing strong resistance welding.

  In order to achieve the above object, a resistance welding method or resistance welding structure according to the present invention includes a plurality of members to be welded arranged in a row and resistance welded to a plate material, and each welded member is electrically connected to each other by the plate material. A plurality of the plate members having a rectangular shape are provided, and each plate member is placed in contact with each member to be welded and arranged in a row with a predetermined gap therebetween. And at least one projection formed at both ends of the plate member in the row direction so as to face the welded part of the member to be welded and project toward the welded part, and each of the pair of welding electrodes is formed on the plate material. A pair of welding electrodes are placed in contact with the outer surface opposite to the members to be welded and arranged in a row direction of the plate members, and the two plate members are connected to the members to be welded by energizing the welding electrodes. welding It is intended to projection resistance welded at.

  According to this configuration, a plurality of plate members are provided having a rectangular shape, each plate member is brought into contact with each member to be welded, and arranged side by side with a predetermined gap in the column direction, Since at least one projection is formed at both ends in the row direction of the plate material so as to face the welded portion of the member to be welded and protrude toward the welded location, even if the plate material has high conductivity, By forcibly inducing a welding current and a heat generation center at a location, diffusion of current and heat to the periphery of the plate material is prevented, and a sufficient resistance current and heat generation are ensured to enable strong resistance welding. Accordingly, combined with the formation of the gaps in the row direction between the plate materials and the projections on the plate materials, it is possible to easily perform strong resistance welding even with a plate material having high conductivity.

  In the present invention, it is preferable that the projections of the respective plate materials are respectively formed in the vicinity of the front end in the row direction and arranged at positions close to each other with a gap between the two plate materials interposed therebetween. In this case, the welding current and the heat generation center can be forcibly guided to the welding location more easily, and a stronger resistance welding can be achieved.

  In the present invention, the plate material is preferably made of copper or nickel. Therefore, even if the conductivity of the plate material that is resistance-welded to the member to be welded is higher, it is possible to perform strong resistance welding.

  Preferably, the member to be welded is a battery, and the plate member is a terminal plate that electrically connects the batteries to each other. In this case, even a high-power battery pack using a terminal plate with high conductivity can be firmly resistance welded.

  Preferably, the projection of the projection formed on the plate has a rectangular square shape in a side view. Moreover, it is the protrusion shape extended in the width direction which has a mountain shape in front view and is a long type | mold shape with a long top part. Therefore, the shape of the protruding portion makes it difficult for heat generated at the tip to escape to the terminal plate, so that resistance welding can be performed with low power.

  Preferably, in the projection, an annular groove surrounding the base is provided in advance at the base of the protrusion. In this case, at the base of the protrusion, the groove causes the welding current to be guided more forcibly so as to go to the protrusion rather than to the periphery of the terminal plate, so that sufficient current density is maintained, and stronger resistance welding is performed. Is possible.

  In the present invention, when the members to be welded arranged in a row and the plate material brought into contact therewith are resistance-welded with a gap in the row direction between the two plate materials, the gap in the row direction between the plate materials and By forming a projection on the plate material, it is possible to easily perform strong resistance welding even for a plate material having high conductivity.

It is a perspective view which shows the resistance welding method concerning one Embodiment of this invention. (A) is a schematic front view showing projection resistance welding, and (B) is a schematic side view thereof. (A) is a top view which shows the state in which the projection was formed in the terminal board, (B), (C) is an enlarged perspective view. (A)-(D) are perspective views which show the modification of a projection. It is a schematic diagram which shows the conventional resistance welding method.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a resistance welding method in which a plurality of members to be welded according to the present invention are resistance welded to a plate material, FIG. 2 (A) is a front view showing projection resistance welding, and FIG. As shown in FIG. 1, in the resistance welding method of the present invention, a plurality of batteries 1 that are a plurality of members to be welded are arranged in a line, and resistance welding is performed with terminal plates 2 and 2 that are plate members, and each battery 1 is connected to each other. Electrical connection is made by the terminal plates 2 and 2.

  The terminal board 2 is made of, for example, copper or a copper alloy. In addition, you may use the product made from nickel whose electrical conductivity is lower than copper.

  The terminal plate 2 has a rectangular shape and is provided in a plurality, and is arranged in contact with the welding location (electrode) 1a of each battery 1 with a predetermined gap S in the column direction Y. ing. That is, the electrode 1a of each battery 1 is electrically connected to the adjacent battery 1 by the two terminal plates 2 and 2 with a predetermined gap S therebetween.

  As shown in FIG. 2A, the terminal plates 2 and 2 are arranged with gaps S in the column direction Y, and are opposed to the electrodes 1a of the batteries 1 at both ends of the terminal plate 2 in the column direction Y. Thus, at least one projection 5 that protrudes toward the electrode 1a is formed. The terminal plate 2 is provided with a welding electrode contact surface against which the welding electrodes 10 and 11 are pressed against the outer surface opposite to the battery 1.

  As shown in FIG. 3A, the projections 5 are formed at both ends of the terminal plates 2 and 2 extending in the column direction Y for each position of the electrode 1 a of the battery 1. In this example, as shown in FIG. 3B, the projection 5 has, for example, a conical protrusion 6 formed by pressing, and two terminal plates 2 having a gap S for each electrode 1a. A total of four protrusions 6 are provided, two at each of two end portions in the column direction Y. Here, a total of four protrusions 6 are illustrated, but this number is not limited at all.

  In addition, as shown in FIG. 3C, the projection 5 may be previously provided with an annular groove 7 surrounding the base portion at the base of the protruding portion 6. The width of the groove 7 is smaller than the width of the base of the protruding portion 6, and the depth thereof is smaller than the height of the protruding portion 6.

  Each of the pair of welding electrodes 10, 11 in FIG. 1 is in contact with the outer surface (upper surface in the figure) of the terminal plates 2, 2 opposite to the battery 1, and the pair of welding electrodes 10, 11 are of the terminal plates 2, 2. They are spaced apart in the column direction Y. The pair of welding electrodes 10 and 11 are energized, and the batteries 1 and 1 and the two terminal plates 2 and 2 are respectively subjected to projection resistance welding.

The operation of the above resistance method will be described.
In FIG. 1, first, terminal plates 2 and 2 having a rectangular shape are arranged in contact with the electrodes 1 a of a plurality of batteries 1 with a gap S in the column direction Y.

  A total of four projections 5 are formed at both ends of each terminal plate 2 and 2 so as to project opposite to the electrode 1a of the battery 1 (FIG. 3B), as shown in FIG. As described above, the pair of welding electrodes 10 and 11 that are respectively movable in the vertical direction are supplied with electric power from a welding power source (not shown) and are energized. When the welding electrodes 10 and 11 are applied to the terminal plates 2 and 2 and energized, the welding current A passes from the positive welding electrode 11 through the terminal plate 2 through the electrode 1a of the battery 1 and through the terminal plate 2. Flow toward the negative welding electrode 10. As a result, a nugget (alloy layer) 8 is formed between the terminal plates 2 and 3 and the electrode 1 a of the battery 1 by resistance heat generation, and the electrode 1 a of the battery 1 is resistance-welded to the terminal plates 2 and 3. In this example, the anode is resistance-welded as the electrode 1a of the battery 1, but the cathode is the same.

  The welding current A and the heat generation center are forcibly guided to pass through the projection 5 formed on the terminal plates 2 and 2 and reach the electrode 1a. As a result, the current A2 is reduced as shown in FIG. 2 compared to the current A2 that diffuses in the peripheral direction of the conventional terminal plates 2 and 2 in FIG. However, it is possible to secure a sufficient welding current A and heat generation and perform strong resistance welding.

  3C, when the annular groove 7 is provided at the base of the protrusion 6, the groove 7 causes the welding current A to go to the protrusion 6 rather than toward the periphery of the terminal plates 2 and 2. As it goes, it is more forcibly induced and a sufficient current density is maintained, and a stronger resistance welding is possible.

  As described above, according to the present invention, a plurality of terminal plates (plate members) 2 having a rectangular shape are provided, and each terminal plate 2 is brought into contact with each battery (member to be welded) 1 so as to be predetermined in the column direction Y. Are arranged side by side with a gap S therebetween, and at least one projection 5 projecting toward the electrode 1a at each end of the terminal plate 2 in the column direction Y, facing the electrode 1a of the battery 1 respectively. Therefore, even if the terminal plate 2 has a high conductivity, the current and heat are prevented from diffusing around each terminal plate 2 by forcibly inducing a welding current and a heat generation center in the electrode 1a. As a result, sufficient resistance welding and heat generation can be ensured, and strong resistance welding can be achieved. Accordingly, the gaps S in the row direction Y between the terminal plates 2 and 2 and the formation of the projections 5 on the terminal plates 2 and 2 are combined, so that even the terminal plates 2 and 2 having high conductivity can be easily and firmly strengthened. Resistance welding can be performed.

  4A to 4C are perspective views showing modifications of the projection. In FIG. 4A, the projection 6 of the projection 5 is a rectangular square shape in a side view, and the top surface is a narrow plane. In this example, the protruding portion 6 is formed by burring and has a square hole, but may be formed by forging or cutting without a square hole. Due to the shape of the projecting portion 6, heat generated at the tip is unlikely to escape to the periphery of the terminal plate 2, so that resistance welding can be performed with low power.

  In FIG. 4B, the projection 6 of the projection 5 is a long mold having a mountain shape in a side view and a long top, and is formed by pressing, forging, or cutting. Due to the shape of the projecting portion 6, heat generated at the tip is unlikely to escape to the periphery of the terminal plate 2, so that resistance welding can be performed with low power. Moreover, a joining area can be expanded and a reliable welding is attained.

  In FIG. 4C, the projection 6 of the projection 5 is a trapezoidal shape having a trapezoidal side view, and the top surface is a flat surface, and is formed by pressing, forging, or cutting. Due to the shape of the projecting portion 6, heat generated at the tip is unlikely to escape to the periphery of the terminal plate 2, so that resistance welding can be performed with low power.

  4A to 4C, as described above, a circumferential groove 7 surrounding the base of the protrusion 6 may be provided in advance. In FIG. 4D, as an example, a circumferential groove 7 is provided at the base of the protruding portion 6 in FIG.

  Instead of the projections 5 described above, although not shown, the terminal plate 2 may be perforated or may be provided with a recess. In this case, since the pressure by the welding electrode is not applied to the hole or the hollow portion, the electric resistance is increased, and the welding current can be concentrated on the edge of the hole or the hollow.

  In the above embodiment, the battery is used for the member to be welded, but the present invention is not limited to this, and may be used for a capacitor or the like.

1: Welded member (battery)
1a: welding location (electrode)
2: Plate material (terminal plate)
5: Projection 6: Projection 7: Groove 10, 11: Welding electrode S: Gap X: Width direction Y: Row direction

Claims (8)

A resistance welding method in which a plurality of members to be welded are arranged in a row and resistance welded to a plate material, and each of the members to be welded is electrically connected to each other by the plate material,
The plate material is provided with a plurality of rectangular shapes, each plate material is brought into contact with each member to be welded, and arranged side by side with a predetermined gap in the row direction,
Forming at least one projection that protrudes toward the welded part, facing the welded part of the member to be welded, at both ends in the row direction of the plate material,
Each of the pair of welding electrodes is brought into contact with the outer surface of the plate member opposite to the member to be welded, and the pair of welding electrodes are arranged spaced apart in the row direction of the plate member, A resistance welding method in which two plate members are each subjected to projection resistance welding to a welding portion of each member to be welded. In claim 1,
A resistance welding method, wherein the projections of the respective plate materials are respectively formed in the vicinity of the front end in the row direction and arranged at positions close to each other with a gap between the two plate materials interposed therebetween. In claim 1,
The resistance welding method, wherein the plate material is made of copper or nickel. In claim 1,
The resistance welding method, wherein the member to be welded is a battery, and the plate member is a terminal plate that electrically connects the batteries to each other. In claim 1,
The resistance welding method, wherein the projection formed on the plate material has a rectangular square shape in a side view. In claim 1,
The resistance welding method, wherein the projection formed on the plate member has a mountain shape in a front view and a long shape with a long top. In claim 1,
The projection is a resistance welding method in which an annular groove surrounding the base is provided in advance at the base of the protrusion. A plurality of members to be welded are arranged in a row and resistance welded to the plate material, and each welded member is a resistance welding structure electrically connected by the plate material,
The plate material is provided with a plurality of rectangular shapes, each plate material is arranged in contact with each member to be welded, arranged in a row with a predetermined gap in the row direction,
At both ends of the plate material in the row direction, at least one projection is formed so as to face the welded part of the member to be welded and protrude toward the welded part, respectively.
Each of the pair of welding electrodes is brought into contact with the outer surface of the plate member opposite to the member to be welded, and the pair of welding electrodes are arranged apart from each other in the row direction of the plate member, A resistance welding structure in which two plate materials are projection resistance welded to the welded portions of each member to be welded.

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