JP5437090B2 - Method for producing lead-acid battery - Google Patents

Description

  The present invention relates to a method for manufacturing a lead-acid battery used for automobiles and the like, and more particularly to a technique for insert-molding a bushing into a battery lid.

  A lead storage battery used for automobiles or the like includes a synthetic resin battery case and a synthetic resin battery lid which is fused to the upper part of the battery case to close the battery case. These battery case and battery lid are made of synthetic resin such as ABS resin or polypropylene (PP) resin. Normally, a terminal part is provided on the upper part of the battery cover, and this terminal part is made of a lead alloy pole (electrode) extending from the inside of the battery case to the outside and a lead alloy into which this pole is inserted. With bushings. The bushing is formed on the battery lid by insert molding, and the pole column is welded to the bushing and held outside the battery case.

  At the time of insert molding, the bushing main body holding the pole column is molded by inserting the substantially lower half of the bushing body into the resin material of the battery lid. However, substantially no adhesive force is generated between the bushing metal material and the battery lid resin material. For this reason, by forming annular projections in the upper and lower stages on the outer periphery of the lower half of the bushing body, and inserting these annular projections into the resin of the battery lid, the electrolyte in the battery case rises and becomes a terminal Prevents bleeding into the part. (For example, refer to Patent Document 1).

JP 2004-235050 A

By the way, as described above, even when a plurality of annular protrusions are provided on the outer periphery of the bushing body, the bushing and the battery lid do not adhere to each other, and a minute gap is generated at the boundary surface. In some cases, the electrolyte in the battery case crawls up through the gap and discolors the terminal portion. In order to prevent this, an annular protrusion that increases in thickness from the base end side toward the distal end side is formed, and this annular protrusion is inserted into the resin, so that the resin material between the battery case lid and the resin material By providing an anchor effect, it is assumed that the adhesion between the bushing and the resin material is improved.
However, it is difficult to manufacture a bushing provided with an annular protrusion of this shape by a casting method. In addition, it is possible to cut the annular projection of the bushing after casting, or to plastically process the tip to have the same shape, but in this method, the process of processing the bushing goes into an extra step, There was a problem that the cost would increase significantly.
The present invention realizes a lead-acid battery manufacturing method that can improve the adhesion between the bushing and the battery lid by an inexpensive method and prevent the electrolyte from seeping out.

In order to achieve the above object, the present invention includes a metal bushing integrally provided with a plurality of annular protrusions extending in the circumferential direction on the outer periphery of a main body holding an electrode, and the bushing is attached to a resin battery lid. the method of manufacturing a lead-acid battery which is formed by insert molding, at least one Rutotomoni provided a gap between the annular projection and the mold for insert molding, between the mold and the body part, the one When the annular protrusion is plastically deformed, another gap is formed to absorb the extension of the main body, the mold is disposed with respect to the bushing, the resin material is filled between the molds, and the pressure of the resin material The one annular projection is plastically deformed in accordance with the shape of the gap.

In this arrangement, prior SL other voids provided between the die and the upper end of the body portion, the gap can be configured to provided between the mold and the upper surface portion of the uppermost annular projection good.

  Further, the shape of the gap between the one annular protrusion and the mold may be configured to have a substantially triangular cross section so that the tip of the one annular protrusion is in contact with the mold. The vertical thickness of the gap between the one annular protrusion and the mold is 0.5 mm to 3 mm, and does not exceed the tip distance of the annular groove provided adjacent to the one annular protrusion. It is good also as a structure.

  According to the present invention, a gap is provided between at least one annular protrusion and a mold for insert molding, the mold is disposed with respect to the bushing, and a resin material is filled between the molds. Since the one annular projection was plastically deformed by the pressure of the resin material in accordance with the shape of the gap, the resin material that flowed in between the plastically deformed annular projections exhibited a so-called anchor effect, and between the bushing and the resin material. Adhesion is improved. As a result, it is possible to omit a process such as processing the cast bushing separately, so that it is possible to improve air tightness and liquid tightness by an inexpensive method, and it is possible to prevent bleeding of the electrolyte. .

FIG. 1A is a side cross-sectional view showing a mold disposed on a bushing, and FIG. 1B is a side cross-sectional view showing a battery lid in which the bushing is insert-molded. It is the elements on larger scale of FIG. 1A. FIG. 3A is a side sectional view showing a mold disposed in a bushing according to a modification, and FIG. 3B is a side sectional view showing a battery lid in which the bushing is insert-molded.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a side sectional view showing a bushing 1 of a lead storage battery according to the present embodiment and an insert molding die 10 disposed on the bushing 1, and FIG. 1B is an insert molding of the bushing 1. FIG. 4 is a side sectional view showing a battery lid 20. FIG. 2 is a partially enlarged view of FIG. 1A.
As shown in FIGS. 1A and 1B, the bushing 1 includes a hollow cylindrical main body 2 made of a lead alloy and a plurality of upper and lower stages (in the present embodiment, three stages) integrally on the outer periphery of a substantially lower half. ) And an annular projection 3 formed to project. Each annular protrusion 3 is a hook-shaped protrusion continuously extending in the circumferential direction of the main body 2, and an annular groove 4 is formed between the adjacent annular protrusions. The outermost annular projection 3A has an outer diameter dimension larger than the outer diameter dimension of the lower annular projection 3. In this embodiment, the bushing 1 is produced by gravity casting using a mold (not shown) having a predetermined shape, for example, under conditions of a mold temperature of 180 to 240 ° C. and a lead alloy molten metal temperature of 400 to 440 ° C.

As shown in FIG. 1A, the mold 10 is for insert-molding the bushing 1 into the battery lid 20 (FIG. 1B), and includes a pair of upper and lower upper molds 11 and 12. Yes. A space 13 filled with a resin material (for example, ABS resin or polypropylene (PP) resin) is formed between the upper mold 11 and the lower mold 12, and the resin material is injected into the space 13. As a result, as shown in FIG. 1B, the battery lid 20 is formed by inserting the lower side of the uppermost annular projection 3 </ b> A of the bushing 1.
As shown in FIG. 2, the upper mold 11 is formed in a shape substantially joined to the upper half of the bushing 1. In this configuration, when the upper mold 11 and the lower mold 12 are arranged on the bushing 1, A sealed first gap 14 is formed between the upper surface 3A1 of the uppermost annular projection 3A and the upper mold 11 in contact therewith, and between the upper end surface 2A of the main body 2 and the upper mold 11 A second gap (other gap) 15 is formed in
The first gap 14 is formed above the uppermost annular protrusion 3A to be deformed, and the uppermost annular protrusion 3A is formed by a resin material injected into the space 13 with a high pressure (for example, 100 MPa). This is for plastic deformation in accordance with the shape of the first gap 14. The first gap 14 is formed by cutting a part of the upper mold 11 in contact with the annular protrusion 3A. The base end side of the annular protrusion 3A has a height H, and the distal end side of the annular protrusion 3A is formed. And is formed in a sealed space having a substantially triangular cross section so as to be in contact with the upper mold 11.
Further, the lower end surface 3A2 of the annular protrusion 3A is formed at a height position substantially the same as the upper surface 11A of the upper mold 11 forming the space 13, or a slightly higher height position than the upper surface 11A. The first gap 14 may be formed in a semi-sector cross section.

The second gap 15 is for absorbing the extension (deformation amount) generated in the main body 2 when the uppermost annular protrusion 3A is plastically deformed. When the annular protrusion 3A is deformed, the main body 2 prevents the main body 2 from being distorted or excessively stressed.
In addition, by providing the second gap 15 between the upper end surface of the main body 2 and the upper mold 11, the injection pressure when the annular protrusion 3 </ b> A is deformed upward can be used smoothly to extend the main body 2. It is possible to reduce stress transmission loss.

When the bushing 1 is insert-molded into the battery lid 20, as shown in FIG. 1A, the bushing 1 is disposed in the upper mold 11 and the lower mold 12, and in this state, the upper mold 11 and the lower mold 12 are placed. A resin material is injected into the space 13 between the two.
Then, due to the stress of the injected resin material, the uppermost annular protrusion 3A is plastically deformed according to the shape of the first gap 14 and the main body 2 is plastically deformed according to the shape of the second gap 15. Is done. And the battery cover 20 provided with the top-plate part 21 and the junction part 22 joined to the bushing 1 is formed with this injected resin material.
In this case, in the annular groove 4A between the uppermost annular protrusion 3A and the second annular protrusion 3B, the base end side of the annular groove 4A is higher than the distal end side as shown in FIG. 1B. Therefore, the resin material forming the joining portion 22 flowing into the annular groove 4A exhibits a so-called anchor effect, and the adhesion between the bushing 1 and the resin material is improved.
In the present embodiment, it has been found that the height (thickness) H of the first gap 14 is desirably 0.5 mm to 3 mm according to experiments by the inventors. When the height H is smaller than 0.5 mm, the deformation amount is small, and the resin material cannot sufficiently exhibit the anchor effect. On the other hand, when the height H is larger than 3 mm, the injection pressure needs to be excessively increased, and the efficiency is lowered. Furthermore, it is desirable that the height H of the first gap 14 does not exceed the tip distance of the annular groove 4A. This is because if the height H of the first gap 14 is larger than the tip distance of the annular groove 4A, the tip of the annular groove 4A is sealed by the change of the annular protrusion 3A, and the resin is cut. The battery lid 20 thus molded is then applied to the opening of the battery case to seal the battery case, and the positive and negative electrodes housed in the battery case are alternately stacked via separators. A pole column (electrical component) formed in the electrode plate group is penetrated into an internal hollow portion of the body portion 2 of the bushing 1 and welded to each other so that the body portion 2 holds the pole column.

Next, a modified example will be described.
3 is a modified example of FIG. 1, FIG. 3A is a side sectional view showing a mold 10 disposed in the bushing 1 according to the modified example, and FIG. 3B is a battery cover in which the bushing 1 is insert-molded. FIG.
3, members that are the same as those in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted.
In the modification shown in FIG. 3, the first gap 24 is different from the first gap 14 described above. Specifically, the bushing 1 is formed such that the uppermost annular projection 3D formed on the outer periphery of the main body 2 is inclined upward from the base end portion to the tip end portion of the upper surface 3D1. On the other hand, the upper mold 11 corresponding to this is horizontal, and the lower surface 11B of the portion corresponding to the uppermost annular projection 3D is formed substantially parallel to the lower surface 13A of the upper mold 11 forming the space 13. For this reason, when the bushing 1 is disposed on the upper mold 11 and the lower mold 12, the base end side of the annular protrusion 3 </ b> D has a height H between the uppermost annular protrusion 3 </ b> D and the upper mold 11. And a sealed first gap 24 having a substantially triangular cross section so as to be in contact with the upper mold 11 on the tip end side of the annular protrusion 3D is formed.
In this modification, the first gap 24 is formed between the uppermost annular protrusion 3D and the upper mold 11 by forming an inclined surface on the upper surface of the uppermost annular protrusion 3D of the bushing 1. . For this reason, since the same upper mold 11 can be used as it is, it is possible to easily prevent the electrolyte from exuding only by changing the design of the bushing 1.

  As described above, according to the present embodiment, the metal bushing 1 integrally provided with the plurality of annular protrusions 3A to 3C extending in the circumferential direction is provided on the outer periphery of the main body 2 that holds the pole column. In the method of manufacturing a lead storage battery formed by insert molding the bushing 1 on a resin battery lid 20, a first gap 14 is provided between at least the uppermost annular projection 3A and the upper mold 11 for insert molding. Then, the upper mold 11 and the lower mold 12 are arranged with respect to the bushing 1, the resin material is filled between the upper mold 11 and the lower mold 12, and the uppermost annular protrusion 3A is pressed by the pressure of the resin material. 2 is plastically deformed in the direction of the arrow X in FIG. 2 in accordance with the shape of the first gap 14, so that the resin material that flows between the plastically deformed uppermost annular protrusion 3A and the second annular protrusion 3B Exerts the so-called anchor effect, Adhesion between the ring 1 and the resin material is improved. As a result, it is possible to omit steps such as processing the cast bushing 1 separately, so that it is possible to improve air tightness and liquid tightness by an inexpensive method, and to prevent bleeding of the electrolyte. it can.

  According to the present embodiment, the second gap 15 is provided between the main body 2 and the upper mold 11 to absorb the extension of the main body 2 when the uppermost annular projection 3A is plastically deformed. Therefore, when the annular protrusion 3A is deformed, excessive stress is prevented from being applied to the main body 2 and the annular protrusion 3A.

  According to the present embodiment, the second gap 15 is provided between the upper end surface 2A of the main body 2 and the upper mold 11, and the first gap 14 is the upper surface 3A1 of the uppermost annular projection 3A. Since the annular projection 3A is deformed upward, the injection pressure when the annular protrusion 3A is deformed upward can be used as a force that allows the main body 2 to smoothly extend toward the second gap 15, and the stress Transmission loss can be reduced.

  Further, according to the present embodiment, the shape of the first gap 14 between the uppermost annular protrusion 3A and the upper mold 11 is such that the tip of the uppermost annular protrusion 3A and the upper mold 11 are in contact with each other. Since the cross section is substantially triangular, the annular groove 4A formed between the uppermost annular protrusion 3A and the second annular protrusion 3B is prevented while preventing the resin material from flowing into the first gap 14. The annular projection 3A is lifted upward by the injection pressure of the resin material that has flowed in, and is plastically deformed in accordance with the shape of the first gap 14. As a result, the annular groove 4A is deformed so that the base end side of the annular groove 4A is higher than the distal end side, so that the resin material forming the joint 22 flowing into the annular groove 4A is a so-called anchor. An effect is exhibited and the adhesiveness between the bushing 1 and the resin material is improved.

  Further, according to the present embodiment, the thickness of the first gap between the uppermost annular protrusion 3A and the upper mold 11 in the vertical direction is 0.5 mm to 3 mm, and the uppermost annular protrusion 3A is Since it forms so that the front-end | tip distance of the annular groove 4A provided adjacently may not be exceeded, the adhesiveness between the bushing 1 and the resin material is improved, suppressing cyclic | annular protrusion 3A distortion.

  Each embodiment mentioned above shows one mode of the present invention to the last, and can be arbitrarily modified and applied without departing from the gist of the present invention.

  For example, although the number of stages of the annular protrusion 3 is three stages that are generally used for lead acid batteries for automobiles, the number may be reduced in the case of a lead acid battery for motorcycles.

DESCRIPTION OF SYMBOLS 1 Bushing 2 Main-body part 2A Upper end surface 3, 3A, 3B, 3C, 3D Annular protrusion 3A1, 3D1 Upper surface 3A2 Lower end surface 4 Annular groove 10 Mold 11 Upper mold 12 Lower mold 13 Space 14, 24 First space | gap ( Gap)
15 Second gap (other gaps)
20 Battery cover 21 Top plate part 22 Joint part

Claims (4)

A lead-acid battery manufacturing method comprising a metal bushing integrally provided with a plurality of annular projections extending in the circumferential direction on the outer periphery of a main body holding an electrode, and insert-molding the bushing into a resin battery lid ,
Rutotomoni provided a gap between the at least one annular projection and the mold for insert molding, between the mold and the body portion, the extension of the main body portion when the one of the annular projection is plastically deformed Provide another gap to absorb , place the mold with respect to the bushing, fill the resin material between the mold, the one annular projection into the shape of the gap with the pressure of the resin material A method for producing a lead-acid battery, characterized by being plastically deformed together. The other gap is provided between the die and the upper end of the body portion, claim the gap is characterized in that provided between the mold and the upper surface portion of the uppermost annular projection 1 The manufacturing method of lead acid battery as described in 2. Shape of the gap between the die and the one annular projection are to claim 1 or 2, characterized in that the the distal end portion of the one annular projection the mold are in contact so that substantially triangular cross section The manufacturing method of the lead acid battery of description. The vertical thickness of the gap between the one annular protrusion and the mold is 0.5 mm to 3 mm, and does not exceed the distance between the tips of the annular grooves provided adjacent to the one annular protrusion. The method for producing a lead-acid battery according to any one of claims 1 to 3 , wherein:

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