JP4459106B2 - Spot welding method for lead plate - Google Patents

Description

  The present invention relates to a method for spot welding a lead plate while reliably preventing the occurrence of scattering during welding.

  A method of spot welding a lead plate to a base metal is described in Patent Document 1. In the lead plate spot welding method described in this publication, a welding projection is provided on the lead plate in order to ensure welding. A welding convex part is pressed and welded to a base metal with a pair of electrodes. In this method, since the welding projection is pressed against the base metal and spot welding is performed, the reactive current can be reduced and the welding can be reliably performed.

  However, when spot welding of the lead plate by this method, “scattering” in which the metal melts and scatters as fine particles may occur. Scattering not only has an adverse effect on the electronic components, but also causes a short circuit on the conductive parts such as the circuit board. In order to eliminate the harmful effects caused by the scattering, for example, in the manufacturing process of the battery pack, all the products are checked with a magnifying glass to remove the scattering. Scattering is as small as 1 mm or less. For this reason, in reality, it takes a lot of time and money to discover all this. If it is possible to reliably prevent the occurrence of scattering, the yield of spot welded products can be improved, and the inspection process can be saved to reduce manufacturing costs.

  A technique for eliminating the harmful effects of scattering is described in Patent Document 2. This publication describes a battery pack with a unique structure that prevents the harmful effects of scattering. This battery pack is spot-welded to the printed circuit board on which the conductive plate is fixed, the substrate holder disposed on the conductive plate side of the printed circuit board to hold the printed circuit board in a fixed position, and the conductive plate of the printed circuit board. And a battery connected to the printed circuit board through the connected lead plate. The substrate holder has a shatterproof enclosure that surrounds the conductive plate provided on the printed circuit board. The substrate holder is provided with a penetrating portion on the inner side surrounded by the scattering prevention enclosure, and the lead wire is spot welded to the conductive plate at the penetrating portion.

The battery pack having this structure can prevent adverse effects caused by spot dust generated when the lead plate is spot welded to the printed circuit board. It is equipped with a substrate holder on the conductive plate side of the printed circuit board to which the conductive plate is fixed, and this substrate holder is provided with a shatterproof enclosure surrounding the conductive plate. This is because spot welding is performed at a through portion inside the anti-scattering enclosure as a state surrounding the conductive plate provided on the substrate.
JP-A-8-255603 JP 2003-17021 A

  The battery pack of Patent Document 2 can prevent the adverse effects caused by the scattering that occurs during spot welding. However, this battery pack does not prevent the occurrence of scattering itself. In order to prevent the adverse effect of the generated scattering, a scattering prevention enclosure is provided, and this scattering prevention enclosure prevents the influence of the scattering. For this reason, in order to prevent the influence of scattering, it is necessary to have a unique structure in which a scattering prevention enclosure is provided. Therefore, it is impossible to eliminate the harmful effects caused by scattering while keeping the structure the same as the conventional one.

  The present invention has been developed for the purpose of surely preventing the occurrence of scattering, rather than improving the prior art to prevent the adverse effects of scattering. An important object of the present invention is to provide a lead plate spot welding method capable of reliably preventing the occurrence of scattering itself while having a very simple structure.

In the spot welding method for a lead plate of the present invention, a convex portion 7 protruding toward the base metal 3 to which the lead plate 4 is welded is provided on the lead plate 4, and the lead plate 4 having the convex portion 7 is formed by a pair of electrodes 10. Pressing against the metal 3, the lead plate 4 is pressed against the surface of the base metal 3 with the electrode 10, and the lead plate 4 is spot welded to the base metal 3 by energizing between the pair of electrodes 10 in this state. Further, in the welding method, the electrode pressing position 8 where the electrode 10 presses the lead plate 4 is separated from the convex portion 7, the convex portion 7 is disposed between the pair of electrodes 10, and the lead plate 4 is made of the base metal with the electrode 10. 3, the plate-like lead plate 4 is deformed, and the electrode pressing position 8 of the lead plate 4 is brought into contact with the base metal 3. In this state, a current is passed between the pair of electrodes 10, so that the lead plate 4 is Weld to the base metal 3.

  In the spot welding method for a lead plate of the present invention, a plurality of convex portions 7 are arranged on a straight line on the lead plate 4, and a line segment connecting the plurality of convex portions 7 is arranged between a pair of electrodes 10. The lead plate 4 can be pressed against the base metal 3 with the electrode 10 to weld the lead plate 4 to the base metal 3.

  In the spot welding method of the lead plate of the present invention, the lead plate 4 is provided with a convex portion 7 extending in a certain direction, both sides of the convex portion 7 are pressed with a pair of electrodes 10, and the lead plate 4 is welded to the base metal 3. can do. The cross-sectional shape of the convex portion 7 extending in a certain direction can be any one of a curved shape, a V shape, and a U shape.

  In the spot plate welding method of the present invention, the lead plate 4 is provided with one convex portion 7 and both sides of the convex portion 7 are pressed with a pair of electrodes 10 to weld the lead plate 4 to the base metal 3. Can do.

  In the spot plate spot welding method of the present invention, the base metal 3 can be a metal plate fixed to the circuit board 2.

  In the welding method of the present invention, the lead plate is provided with a convex portion, and the portion separated from the convex portion is pressed with an electrode to perform spot welding, while reliably preventing the occurrence of scattering. Features that can be realized. Incidentally, as will be described in detail later, in the conventional method in which a welding convex portion is provided on the lead plate and this portion is pressed by an electrode and spot welded, when 110 lead plates are spot welded to the base metal, five pieces are obtained. There is no scatter in the lead plate, some scatter occurs in the 48 lead plates, the 34 lead plates scatter to the middle of the weld trace, and the 15 lead plates cross the weld trace. Scattering is scattered and a large amount of scattering occurs on the eight lead plates. On the other hand, a convex portion provided on the lead plate is disposed between the pair of electrodes, and the electrode pressing position away from the convex portion is the electrode. In the method of the present invention in which spot welding is performed by pressing, if 110 lead plates are spot-welded to the base metal, the occurrence of scattering can be eliminated at all of the lead plates. As proved from this, the welding method of the present invention realizes an extremely excellent feature that allows spot welding of the lead plate to the base metal while minimizing the occurrence of scattering. It is considered that this feature of the present invention is realized by synergistically adjusting the electrode pressing force to an ideal pressure and reducing the reactive current. This is because the amount of scattering is affected by the pressing force and reactive current at the spot welding position. As described above, the method of the present invention that can reliably prevent the occurrence of the scattering can omit the step of removing the scattering using the magnifying glass after spot welding the lead plate to the base metal. Therefore, it is possible to prevent the occurrence of scattering and improve the yield, while saving labor in the inspection process, reducing the manufacturing cost, and realizing the feature of mass production of high quality products.

  Embodiments of the present invention will be described below with reference to the drawings. However, the examples shown below exemplify a lead plate spot welding method for embodying the technical idea of the present invention, and the present invention does not specify the welding method as the following method or apparatus.

  Further, in this specification, in order to facilitate understanding of the scope of claims, numbers corresponding to the members shown in the examples are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the members shown in the claims are not limited to the members in the embodiments.

  In the battery pack shown in FIGS. 1 to 4, the battery assembly in which the circuit board 2 is connected to the battery 1 is housed in an outer case 9 including an upper case 9A and a lower case 9B. In the battery pack, a lead plate 4 is spot welded to a base metal 3 fixed to the circuit board 2. In this battery pack, a lead plate 4 is connected to a sealing plate 1B which is a positive and negative electrode of the battery 1 and a convex electrode 1A. The lead plate 4 having one end connected to the convex electrode 1 </ b> A has a protective element 5 connected in the middle and the other end spot-welded to the base metal 3 of the circuit board 2. The lead plate 4 having one end connected to the sealing plate 1B is spot welded to the base metal 3 of the circuit board 2.

  The circuit board 2 is a printed board on which an output terminal (not shown) and an electronic circuit 6 are mounted. If scattering that occurs when the lead plate 4 is spot-welded to the base metal 3 of the circuit board 2 adheres to the circuit board 2, it causes the electronic circuit 6 to fail or adheres to the conductive part and causes a short circuit.

  FIG. 5 to FIG. 14 show the lead plate 4 that prevents the occurrence of scattering when spot welding is performed. The lead plate 4 shown in these drawings has a convex portion 7 protruding toward the base metal 3. The lead plate 4 having the convex portion 7 is pressed against the base metal 3 by a pair of electrodes. The state in which the lead plate 4 shown in FIGS. 5 and 6 is pressed by the electrode 10 is shown in FIGS. As shown in these drawings, the electrode 10 does not press the convex portion position of the lead plate 4. The electrode pressing position 8 where the electrode 10 presses the lead plate 4 is separated from the convex portion 7. The electrode 10 presses the lead plate 4 against the base metal 3 such that the convex portion 7 is disposed between the pair of electrodes 10. When the electrode 10 presses the lead plate 4 so that the electrode pressing position 8 is separated from the convex portion 7, the electrode pressing position 8 of the lead plate 4 is separated from the base metal 3 by the convex portion 7, as shown in FIG. . The lead plate 4 in FIG. 15 is pressed by the electrode 10 and deformed as shown in FIG. 16 to bring the electrode pressing position 8 into contact with the base metal 3. In this state, electricity is passed between the pair of electrodes 10, and the lead plate 4 and the base metal 3 are welded at the electrode pressing position 8.

  The lead plate 4 of FIGS. 5 and 6 is provided with two convex portions 7. In this way, the lead plate 4 provided with the plurality of protrusions 7 is provided with the plurality of protrusions 7 arranged in a straight line, and a line segment connecting each protrusion 7 is disposed between the pair of electrodes 10. The lead plate 4 is pressed against the base metal 3 with the electrode 10. As shown in FIG. 15, the convex portion 7 disposed between the electrodes 10 separates the electrode pressing position 8 from the base metal 3, so that the lead plate 4 is deformed by the electrode 10 so that the electrode pressing position 8 is positioned at the base metal 3. Contact. In the lead plate 4 in which the plurality of convex portions 7 are arranged in a straight line, the line segment connecting the convex portions 7 is positioned at the center of the pair of electrodes 10, and the line segment is connected to the pair of electrodes 10. It arrange | positions so that it may orthogonally cross. In this state, the electrode 10 that presses the lead plate 4 can press the lead plate 4 against the base metal 3 with a good balance between left and right, and weld the pair of electrode pressing positions 8 to the base metal 3 with a good balance. The lead plate 4 in the figure is provided with two convex portions 7, but three or more convex portions can also be provided. The three or more convex portions are preferably arranged on a straight line, but need not necessarily be arranged on a straight line. For example, they may be arranged in a staggered manner, or may be arranged at the vertices of a polygon or irregularly. .

  The lead plate 4 of FIGS. 7 and 8 is provided with one convex portion 7. 5 to 14 show the electrode pressing position 8 of the lead plate 4 with a chain line. The lead plate 4 having one convex portion 7 is based on the lead plate 4 with electrodes so that the convex portions 7 are arranged between the electrodes, that is, the electrode pressing positions 8 are arranged on both sides of the convex portion 7. Press against metal 3. Since the convex portion 7 disposed between the electrodes separates the electrode pressing position 8 from the base metal 3, the lead plate 4 is deformed by the electrode to bring the electrode pressing position 8 into contact with the base metal 3. In this state, when the pair of electrodes are energized, the lead plate 4 and the base metal 3 are welded at the electrode pressing position 8.

  The lead plate 4 of FIGS. 9 to 14 is provided with a convex portion 7 extending in a certain direction. The lead plate 4 in FIGS. 9 and 10 has a curved cross-sectional shape of the convex portion 7, and the lead plate 4 in FIGS. 11 and 12 has a V-shaped cross sectional shape of the convex portion 7, and FIGS. The lead plate 4 has a U-shaped cross section of the convex portion 7. The lead plate 4 shown in these drawings presses both sides of the convex portion 7 with electrodes as shown by a chain line in the drawing. In other words, the convex portion 7 is disposed between the pair of electrodes. The lead plate 4 having the convex portion 7 extending in a certain direction is pressed by the electrode 10 so that the longitudinal direction of the convex portion 7 is orthogonal to the line segment connecting the pair of electrodes 10. When the electrode 10 presses the lead plate 4 in this state, the lead plate 4 can weld the electrode pressing positions 8 on both sides of the convex portion 7 to the base metal 3 with good balance. However, it is also possible to perform spot welding by arranging the projections so that the longitudinal direction intersects the line segment connecting the pair of electrodes and pressing the lead plate with the electrodes.

It is demonstrated in the following examples whether the method of the invention achieves very good characteristics.
A nickel plate having a thickness of 0.1 mm and a width of 3 mm is used as the lead plate 4. As shown in FIGS. 5 and 6, the lead plate 4 is provided with two convex portions 7 on both sides. The convex portion 7 is circular and has a diameter of 0.5 mm, a protrusion amount of 0.1 mm, and an interval between the two convex portions 7 of 2 mm. The lead plate 4 is pressed by a pair of electrodes 10 so as to straddle the two convex portions 7 and spot-welded. The tip of the electrode 10 that presses the lead plate 4 has a cylindrical shape with a diameter of 1.7 mm, and the pressing force with which the electrode 10 presses the lead plate 4 is 4 kgf. Further, the electrode 10 is energized and the power supply voltage is increased so that the voltage rises to 1V 200 μsec later, and then 1.5 V is maintained for 120 μsec, then the current is cut off, and the lead plate 4 is connected to the base metal 3 Weld to.
When 110 lead plates 4 are spot-welded to the base metal 3 by the above method, no scattering occurs.

Comparative example

  On the other hand, as a method of the comparative example, the lead plate is not provided with the convex portion shown in Example 1, but a welding convex portion is provided as in the prior art, and the weld convex portion is pressed with an electrode, and the lead The plate was spot welded to the base metal. In this comparative example, a nickel plate having a thickness of 0.1 mm and a width of 3 mm was used as the lead plate as in Example 1, and the spot welding conditions were the same as those in Example 1. When 110 lead plates are spot-welded to the base metal by this method, the five lead plates are not scattered, the 48 lead plates are slightly scattered, and the 34 lead plates are weld marks. Scattering scatters to the middle of the fifteen, 15 lead plates scatter across the welding marks, and 8 lead plates generate a large amount of scatter. From the above, the method of the present invention demonstrates the feature that the lead plate 4 can be spot-welded to the base metal 3 with no occurrence of scattering.

It is a disassembled perspective view which shows an example of the pack battery by which a lead plate is welded with the spot welding method concerning one Example of this invention. It is a disassembled perspective view of the battery pack shown in FIG. It is a perspective view of the battery assembly of the battery pack shown in FIG. FIG. 4 is an exploded perspective view of the battery assembly shown in FIG. 3. It is a perspective view which shows the 1st example of a lead plate. It is a perspective view which shows the 1st example of a lead plate. It is a perspective view which shows the 2nd example of a lead plate. It is a perspective view which shows the 2nd example of a lead plate. It is a perspective view which shows the 3rd example of a lead plate. It is a perspective view which shows the 3rd example of a lead plate. It is a perspective view which shows the 4th example of a lead plate. It is a perspective view which shows the 4th example of a lead plate. It is a perspective view which shows the 5th example of a lead plate. It is a perspective view which shows the 5th example of a lead plate. It is a front view which shows the state which presses the lead board shown in FIG. 5 and FIG. 6 with an electrode. It is a front view which shows the state which pressed the lead board shown in FIG. 5 and FIG. 6 with the electrode. FIG. 17 is a bottom view of the lead plate shown in FIG. 16.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Battery 1A ... Convex part electrode 1B ... Sealing board 2 ... Circuit board 3 ... Base metal 4 ... Lead plate 5 ... Protection element 6 ... Electronic circuit 7 ... Convex part 8 ... Electrode press position 9 ... Outer case 9A ... Upper case 9B ... Lower case 10 ... Electrode

Claims (6)

The lead plate (4) is provided with a convex portion (7) protruding toward the base metal (3) to which the lead plate (4) is welded, and the lead plate (4) having the convex portion (7) is provided with a pair of electrodes ( ) Against the base metal (3), and with the electrode (10), the lead plate (4) is pressed against the surface of the base metal (3) .In this state, the lead plate is energized between the pair of electrodes (10). A method of spot welding (4) to a base metal (3),
The electrode pressing position (8) where the electrode (10) presses the lead plate (4) is separated from the convex portion (7), and the convex portion (7) is disposed between the pair of electrodes (10). ), The lead plate (4) is pressed against the base metal (3), the plate-like lead plate (4) is deformed, and the electrode pressing position (8) of the lead plate (4) is moved to the base metal (3). A method of spot welding a lead plate in which the lead plate (4) is welded to a base metal (3) by bringing the electrodes into contact with each other and energizing between the pair of electrodes (10).   The lead plate (4) is provided with a plurality of protrusions (7) arranged in a straight line, and a line segment connecting the plurality of protrusions (7) is disposed between the pair of electrodes (10), The method of spot welding a lead plate according to claim 1, wherein the lead plate (4) is pressed against the base metal (3) in 10) to weld the lead plate (4) to the base metal (3).   Protrusions (7) extending in a certain direction are provided on the lead plate (4), and the lead plate (4) is pressed against the base metal (3) by pressing both sides of the projecting portion (7) with a pair of electrodes (10). The method of spot welding a lead plate according to claim 1, wherein the welding is performed.   4. The spot welding method for a lead plate according to claim 3, wherein the cross-sectional shape of the convex portion (7) extending in a certain direction is any one of a curved shape, a V shape, and a U shape.   One lead (7) is provided on the lead plate (4), both sides of the convex (7) are pressed with a pair of electrodes (10), and the lead plate (4) is welded to the base metal (3). A method of spot welding a lead plate according to claim 1. 2. The method of spot welding a lead plate according to claim 1, wherein the base metal (3) is a metal plate fixed to the circuit board (2).

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