JP4764066B2 - Method for manufacturing storage battery lid - Google Patents

Description

  The present invention relates to a technique for enhancing sealing performance in an electrode rod penetrating portion of a lid of a storage battery.

The use of rechargeable electrical products such as secondary batteries, electrolytic capacitors and capacitors (referred to as storage batteries) is increasing along with the electrical and electronic use of automobile equipment.
In the storage battery, the storage element is housed in a sealed case, and electrical energy is taken out from the storage element through the electrode. Therefore, the electrode needs to protrude through the lid of the sealed case.

Sealing (sealing) between the lid and the electrode is important, and various seal structures have been proposed (for example, see Patent Document 1).
JP 2000-150324 A (FIG. 3)

  FIG. 12 is a diagram for explaining the basic structure of the prior art. In this storage battery 100, an aluminum lid 102 is fixed to the end of an aluminum cylinder 101 by caulking, and the lid 102 is made of resin. An aluminum terminal 104 is fixed through a sealing member 103.

  The resin includes soft resin and hard resin. Since the resin sealing member 103 is a structural component, hard resin is used. Hard resin has great strength but lacks elasticity.

By the way, when the harness 105 indicated by an imaginary line is attached to the terminal 104 with the bolt 106, external forces in the horizontal direction and vertical direction in the figure are inevitably applied.
In addition, aluminum and resin have different physical properties such as thermal expansion, and fine gaps occur when used for a long time. The fine gap grows into a large crack due to external force, causing problems such as leakage of the electrolyte filled in the cylinder.

Therefore, a structure has been proposed in which an O-ring as a rubber-based sealing member is interposed between the resin sealing member 103 and the aluminum lid 102 or between the resin sealing member 103 and the aluminum terminal 104 ( For example, see Patent Document 2.)
Japanese Patent Laid-Open No. 8-67983 (FIG. 3)

  FIG. 13 is a structural diagram of a conventional technique using an O-ring. A recess 112 is formed in a metal lid 111, a small-diameter recess 113 is formed below the recess 112, and the small-diameter recess 113 is continuously penetrated. Hole 114 is formed. Then, the electrode rod 115 is passed through the through hole 114, the O-ring 116 is fitted into the electrode rod 115, and the O-ring 116 is also fitted into the small diameter recess 113. The basic structure is that the terminal 118 is connected to the upper part of the electrode rod 115, and finally the resin sealing agent 117 is filled in the recess 112 and hardened.

  Even if a minute gap is formed between the metal lid 111 and the resin sealant 117 or between the metal electrode rod 115 and the resin sealant 117 due to aging, the O-ring 116 seals the liquid. Leakage can be prevented.

However, the O-ring 116 is a separate part, and there is a risk of forgetting to attach the O-ring 116. Even if the O-ring 116 is forgotten to be attached, the resin sealing agent 117 exhibits the sealing performance for the time being, so that it is delayed to notice the O-ring 116 forgetting to attach it. Therefore, there is room for improvement.
Therefore, a technique capable of preventing forgetting to attach the O-ring is required.

  This invention makes it a subject to provide the technique which can prevent reliably forgetting to attach the rubber-type sealing material equivalent to an O-ring in the sealing part of a storage battery.

  In order to prevent forgetting to attach the rubber-based sealing material, the present inventors tried to bond the rubber-based sealing material to a resin attached to the lid of the storage battery with a rubber adhesive. However, since the resin (PET resin) exhibits strong water repellency, it has been found that the adhesive strength is small and it cannot be put to practical use.

Therefore, the present inventors conducted the following experiment in order to establish a technique that can be put to practical use.
FIG. 1 is a cross-sectional view of a resin-coated metal plate used in the present invention. A plurality of resin-coated metal plates 30 in which a PET (polyethylene terephthalate) film 32 is laminated on a metal plate 31 are prepared.
The metal plate 31 was an aluminum (A3004-H12) plate of 0.5 mm × 20 mm × 150 mm. Further, the thickness of the PET film 32 was 30 μm. In the figure, L is 150 mm, and the dimension in the front and back direction of the drawing is 20 mm.

FIG. 2 is a cross-sectional view of a sample according to the present invention.
(A): A sample for Comparative Example 1 is obtained by placing an EPDM (ethylene propylene diene rubber) sheet 38 (hereinafter referred to as a rubber sheet 38) directly on a PET film 32 and pressing for 10 minutes at 180 ° C. Obtained.

(B): For the sample for Comparative Example 2, a PPT resin layer 39 was formed by applying a PPT (polypropylene terephthalate) resin to the PET film 32 and drying it at 110 ° C. for 10 minutes. This PPT resin is a conventionally used fusion agent for PET.
Next, a rubber sheet 38 was placed on the PPT resin layer 39 and pressed for 10 minutes at 180 ° C. to obtain a sample.

(C): In the sample for Comparative Example 3, a PPT resin layer 39 was formed by applying a PPT resin to the PET film 32 and drying it at 110 ° C. for 10 minutes.
Next, an imide adhesive (corresponding to CHEMLOK 253X manufactured by Lord USA) was applied to the PPT resin layer 39 and dried under conditions of 80 ° C. for 10 minutes to form an adhesive layer 33.
A rubber sheet 38 was placed on the adhesive layer 33 and pressed for 10 minutes at 180 ° C. to obtain a sample.

(D): The sample for Example 1 was obtained by applying an imide-based adhesive (corresponding to CHEMLOK 253X, manufactured by Lord USA) to the PET film 32 and drying it at 80 ° C. for 10 minutes. Formed.
Next, a rubber sheet 38 was placed on the adhesive layer 33 and pressure-bonded for 10 minutes at 180 ° C. to obtain a sample.

  FIG. 3 is a diagram illustrating the measurement principle of the peel strength, and the force F (N) when the rubber sheet 38 is peeled off for a sample having a width (dimension in the front and back direction) of 20 mm and a length L of 150 mm. ) Is defined as the peel strength. Although the figure explained about the sample of Drawing 2 (a), Drawing 2 (b)-(d) is measured similarly.

FIG. 4 is a graph of measurement results. In Comparative Example 1 (see FIG. 2A), the peel strength is 0.1 N, and the rubber sheet 38 shown in FIG. I did not.
In Comparative Example 2 (see FIG. 2B), the peel strength was 3.2 N, and peeling occurred between the rubber sheet 38 and the PPT resin layer 39 shown in FIG.

In Comparative Example 3 (see FIG. 2C), the peel strength was 44.8 N, and partial peeling occurred between the PPT resin layer 39 and the adhesive layer 33 shown in FIG. .
In Example 1 (see FIG. 2D), the peel strength was 58.2 N, and peeling occurred between the rubber sheet 38 and the adhesive layer 33 shown in FIG.

From the results of Comparative Example 2, it was confirmed that the PPT resin has good compatibility with the PET resin, but has poor compatibility with the EPDM rubber, and the adhesiveness cannot be expected.
Moreover, it is estimated from the result of Comparative Example 3 that the PPT resin was fluidized to reduce the adhesiveness.
In Example 1, since only an imide-based adhesive was used without using a PPT resin, preferable adhesive performance was obtained.

The present invention put into practical use based on the above results is as follows.
According to the first aspect of the present invention, a lid is constituted by a resin-coated metal plate obtained by laminating a PET film on a metal plate, a hole is formed in the lid, and a rubber annular member is integrally attached so as to surround the hole. A step of making a hole in the resin-coated metal plate in the lid of the storage battery so as to keep the air tightness in the electrode rod penetrating portion with the rubber annular member, and at least an imide-based adhesive on the PET film surrounding the hole A step of forming an adhesive layer by applying and drying, a step of setting a resin-coated metal plate including the adhesive layer in a molding die, and injecting a rubber-based molten material into the molding die to form rubber It is characterized by comprising a step of forming an annular member and a step of removing a molding die to obtain a lid.

In the invention according to claim 1, an imide-based adhesive is employed. This imide-based adhesive has a high adhesive strength to the PET film and a high adhesive strength to the rubber annular member. As a result, the rubber annular member can be firmly bonded to the PET film.
Since the rubber annular member corresponding to the O-ring can be integrally attached to the lid, there is no need to worry about forgetting to attach or losing the rubber annular member.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In addition, although a storage battery targets both a cylindrical storage battery and a square storage battery, the following example demonstrates a square storage battery.

  FIG. 5 is a perspective view of the storage battery according to the present invention. In the storage battery 10, the upper opening of the corrugated (corrugated) cylinder 11 is closed by the lid 12, and the lower opening of the cylinder 11 is closed by the bottom lid 13. It is a sealed case. The bottom lid 13 may be formed simultaneously with the cylinder 11 by a deep drawing method. 14 is an electrode rod, and 15 is a rubber annular member.

  FIG. 6 is a cross-sectional view of the main part of the storage battery according to the present invention, in which a hole 16 is formed in the lid body 12 and an annular member 15 is provided so as to surround the hole 16, and one side of the lid body 12 (downward in the figure). A current collecting plate 17 is disposed on the electrode plate 14, the electrode rod 14 extending from the current collecting plate 17 is projected from the hole 16, and a pressure plate 18 is disposed on the other side of the lid 12 (upward in the figure). The structure which fixes the electrode rod 14 to the cover body 12 by pinching | interposing the annular member 15 with 18 and the current collecting plate 17 is shown.

The pressing plate 18 is a metal plate corresponding to a washer, and presses the annular member 15 by screwing a nut 22 into a screw portion 21 provided on the electrode rod 14.
The current collecting plate 17 is a metal plate that plays a role of collecting electrical energy stored in the power storage element 19.

FIG. 7 is an exploded view of the main part of the storage battery according to the present invention. The base of the electrode rod 14 has a thickness T larger than the diameter d of the electrode rod 14 and thicker than the thickness t of the lid 12. A portion 23 is provided, and the pressing plate 18 is received by the flange portion 23.
Further, the annular member 15 has a so-called kokeshi-shaped cross section composed of a neck portion 25 that is slightly thicker than the thickness T of the flange portion 23 and a head portion 26 that is sufficiently thicker than the thickness T of the flange portion 23, and is elastic. Consists of rich rubber.

  FIG. 8 is an operation diagram of FIG. 7. The electrode rod 14 is passed through the annular member 15 from below, the pressing member 18 is placed, and the screw portion 21 is screwed with a nut 22. This screwing operation is performed until the pressing member 18 stops on the flange 23. When the screwing is finished, the neck portion 25 is slightly compressed and exhibits a sealing property. At the same time, the head portion 26 is greatly compressed, and the primary seal portion is formed at the point P1, the secondary seal portion is formed at the point P2, and the tertiary seal portion is formed at the point P3.

The internal electrolyte and gas reach between the lid 12 and the current collector plate 17 as indicated by the arrow (1). Since the annular member 15 is a rubber plate rich in elasticity, there is no fear of generating a gap, and the sealing performance can be maintained.
Even when the sealing performance of the neck portion 25 is deteriorated due to secular change, the sealing performance can be maintained at the points P1 to P3. As a result, the life of the storage battery can be extended.

  In addition, the annular member 15 may be configured by the neck portion 25 and the head portion 26 as in the embodiment, or may be provided with a thick portion in the middle of the neck portion 25 by making the entire thickness uniform, The annular member 15 may be a rubber plate whose whole or part is thicker than the flange 23.

A method for manufacturing the lid 12 including the rubber annular member 15 having the above configuration will be described below.
FIG. 9 is a manufacturing flow diagram of the lid according to the present invention.
(A) is explanatory drawing of the process of making a hole in a resin-coated metal plate, and a resin-coated metal plate 30 obtained by laminating PET films 32 and 32 having a thickness of 30 to 100 μm on a metal plate 31 such as aluminum is prepared. A through hole 37 and a hole 16 for penetrating the electrode rod are formed in the resin-coated metal plate 30.

  A plan view of the resin-coated metal plate 30 is shown in FIG. As shown in the figure, a hole 16 is formed in the center of the resin-coated metal plate 30, and a plurality of through holes 37 are arranged so as to surround the hole 16. These through holes 37 were opened in order to improve the fixing performance of the rubber annular member 15 (see FIG. 10).

  Returning to FIG. 9, (b) is an explanatory diagram of the adhesive layer forming step, where an imide-based adhesive is applied on the PET films 32, 32 surrounding the hole 16, and is dried at 80 ° C. for 10 minutes. Thus, the adhesive layers 33 and 33 are formed.

  (C) is an explanatory view of the injection process, in which the main part of the resin-coated metal plate 30 including the adhesive layers 33, 33 is set in the molding die 34. Then, a rubber-based molten material is injected from the injection cylinder 35 into the cavity 36.

FIG. 10 is a cross-sectional view of the main part of the completed lid, and shows that the rubber annular member 15 having a kokeshi cross-sectional shape can be integrally formed on the lid 12 with the molding die removed.
The rubber annular member 15 is firmly bonded to the PET films 32 and 32 by the action of the adhesive layers 33 and 33.
In addition, since a part of the rubber annular member 15 flows into the through hole 37 and is solidified, a mechanical connection is obtained.

  That is, the rubber annular member 15 is firmly bonded to the lid body 12 by the adhesive action by the adhesive layers 33 and 33 and the mechanical coupling action by the through hole 37, and from the lid body 12 during use. There is no worry of coming off.

  The storage battery of the present invention is not limited as long as it is a rechargeable electrical product such as a secondary battery, an electrolytic capacitor, or a capacitor.

  The present invention is suitable for a storage battery in which an electrode rod protrudes from a lid.

It is sectional drawing of the resin coating metal plate used by this invention. It is sectional drawing of the sample which concerns on this invention. It is a measurement principle figure of peeling strength. It is a graph of a measurement result. 1 is a perspective view of a storage battery according to the present invention. It is principal part sectional drawing of the storage battery which concerns on this invention. It is an exploded view of the principal part of the storage battery which concerns on this invention. It is an effect | action figure of FIG. It is a manufacturing flow figure of the lid concerning the present invention. It is principal part sectional drawing of the completed cover body. It is a top view of the resin coating metal plate which concerns on this invention. It is a figure explaining the basic composition of the conventional technology. It is a structural diagram of the prior art using an O-ring.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Storage battery, 11 ... Cylindrical body, 12 ... Cover body, 14 ... Electrode rod, 15 ... Rubber annular member, 16 ... Hole, 30 ... Resin-coated metal plate, 31 ... Metal plate, 32 ... PET film, 33 ... Adhesion Agent layer, 34 ... molding mold, 35 ... injection cylinder.

Claims (1)

A lid is constituted by a resin-coated metal plate obtained by laminating a PET film on a metal plate, a hole is formed in the lid, and a rubber annular member is integrally attached so as to surround the hole, and an electrode is formed by the rubber annular member. In the lid of the storage battery that keeps the air tightness in the rod penetration part,
A step of forming a hole in the resin-coated metal plate, a step of forming an adhesive layer by applying and drying at least an imide-based adhesive on the PET film surrounding the hole, and a resin including the adhesive layer It consists of a step of setting a coated metal plate in a molding die, a step of injecting a rubber-based molten material into the molding die to form a rubber annular member, and a step of removing the molding die to obtain a lid. The manufacturing method of the cover body of the storage battery characterized by these.

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