JP2003173766A - Storage lead battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a strap of excellent mechanical strength while restraining corrosion of an anode strap part by setting up a gap between a side face of an erected ear part and the strap part. <P>SOLUTION: By a structure of having a gap widened downward set up between a side face of an anode ear and a strap or a structure of having two steps of width, corrosion resistance of an anode strap is maintained due to the gap, and at the same time, degradation of vibration resistance is restrained. Vibration resistance is further improved by making the anode ear not less than 0.6 mm thick and a distance between a tip end of the gap and an upper part of the strap not less than 2 mm thick. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to lead acid batteries, and more particularly to improvements in negative electrode straps.

[0002]

2. Description of the Related Art Lead acid batteries are generally collectively welded with a lead-antimony alloy or a lead-tin alloy obtained by melting a plurality of ears of the same polarity electrode plate. This welded body is called a strap. In a so-called liquid lead-acid battery in which dilute sulfuric acid as an electrolyte is sufficiently present, this strap is buried in the electrolyte. There is no problem in such a state, but the electrolyte solution decreases,
When the strap is exposed on the electrolyte, or when the electrolyte is impregnated and held in a porous glass separator and no fluid exists, the strap is exposed. Corrosion is likely to occur at the base of the negative electrode ear of the portion, and if it progresses, the negative electrode plate may be broken from the strap.

The reason for this is that if the strap is immersed in the electrolyte, oxygen gas generated from the positive electrode will not be reduced at the base of the negative electrode ear of the strap, but the strap will be exposed from the electrolyte. In a valve-regulated lead-acid battery with no flowing liquid, only a thin electrolyte film is formed on the above part, so oxygen gas generated from the positive electrode penetrates the film and is reduced, and lead is dissolved. , Lead sulfate, and the sulfuric acid content of the electrolytic solution is further reduced. In addition, near the root of the negative electrode ear, there is a heat-affected layer that undergoes heat history during welding, crystals grow, and are susceptible to intergranular corrosion, which accelerates corrosion. . As a preventive measure, it is necessary to devise so that the electrolyte solution is not depleted at the base of the negative electrode ear of the strap portion.

As a concrete measure, Japanese Patent Laid-Open No. 319
No. 3526 proposes to provide a space between the upstanding side of the ear and the strap with a space of 50 μm or more.

FIG. 1 shows a sectional view of the essential part of a strap according to one embodiment of the above proposal. Reference numeral 1 is a negative electrode ear, 2 is a strap, 3 is a mutual dissolution layer, 4 is a heat-affected layer, 5 is a void, and 6 is an electrolytic solution.

As described above, the void 5 allows the electrolytic solution to be easily supplied to the base portion of the negative electrode ear of the strap portion, and the depleted state of dilute sulfuric acid can be avoided. Therefore, dissolution of lead due to reduction of oxygen gas can be prevented and corrosion can be suppressed.

However, depending on the welding conditions, the portion to be welded is only the upper surface of the negative electrode ear due to the provision of this void, and the reduction in strength is unavoidable and the strap may be mechanically broken against severe vibration. .

[0008]

SUMMARY OF THE INVENTION The present invention provides a strap having excellent mechanical strength while suppressing corrosion of the negative electrode strap portion by providing a space between the side surface of the upright ear and the strap portion. Is.

[0009]

As a concrete means for solving the above-mentioned problems, according to claim 1, when a plurality of negative electrode ears are collectively welded to form a strap, from the base of the negative electrode ears of the strap portion. It is characterized in that a void having a width extending downward is provided, and the maximum portion of the void is 60 μm or more.

Providing a space between the side surface of the negative electrode ear and the strap is effective in suppressing corrosion of the negative electrode ear, but in the case of a structure in which a space is provided on the entire side surface of the negative electrode ear, the mechanical strength of the negative electrode ear is increased. However, in the present invention, the decrease in the strength of the strap can be reduced by forming a void in the negative electrode ear of the strap portion that widens from the root portion to the lower portion.

Control valve type lead storage batteries using a lead-calcium-tin alloy system grid were manufactured by varying the maximum width of the lower part of the voids, and were subjected to constant voltage charging in an environment of 60 ° C. to corrode them. Was evaluated. As a result, it was found that if the thickness is less than 60 μm, the diffusion of the electrolytic solution is insufficient and the corrosion inhibiting effect is low.

According to a second aspect of the present invention, when a plurality of negative electrode ears are collectively welded to form a strap, a void having a width of two steps is provided from the base portion of the negative electrode ear of the strap portion along the side surface of the ear. The width of the wide portion is 60 μm or more.

Also in the present invention, the vibration resistance of the strap portion is improved by narrowing the gap width at the base of the negative electrode ear of the strap portion and widening the gap width at the portion located at half the strap thickness. Is improved.

Further, as in claim 1, lead-calcium-
Controlled valve lead-acid batteries using tin alloy grids with various widths of the widest part of the air gap were manufactured, and constant voltage charging was performed in an environment of 60 ° C to evaluate the corrosiveness. . As a result, it was also found that when the thickness is less than 60 μm, the diffusion of the electrolytic solution is insufficient and the corrosion inhibiting effect is low.

According to the third aspect, when a plurality of negative electrode ears are collectively welded to form a strap, the negative electrode ears have a thickness of 0.6.
It is characterized in that it is not less than mm.

According to the present invention, when a gap is provided between the side surface of the negative electrode ear and the strap, it is weak against left and right vibrations, and in order to enhance vibration resistance, the upper surface which is the welding surface of the negative electrode ear. It is effective to increase the area of, that is, increase the thickness of the negative electrode ear.

According to a fourth aspect, when a plurality of negative electrode ears are collectively welded to form a strap, the thickness from the tip of the void to the upper portion of the strap is 2 mm or more.

According to the present invention, when a gap is provided between the side surface of the negative electrode ear and the strap, it is weak against left and right vibrations, and in order to enhance the vibration resistance, the negative electrode ear and the additional lead are added. It is more effective for improving the vibration resistance as the thickness of the portion where the strap is formed including the mutual dissolution layer in which the two are dissolved is increased.

[0019]

DETAILED DESCRIPTION OF THE INVENTION

EXAMPLES The present invention will be described in detail below with reference to examples. 2 and 3 are cross-sectional views of essential parts showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a first embodiment of the present invention. 1 is a negative electrode ear, 2 is a strap, 3 is a mutual dissolution layer,
Reference numeral 4 is a heat-affected layer, 5a is a void which is a feature of the present invention, and has a shape that expands downward, and 6 indicates an electrolytic solution, respectively.

[0021] As described above, by making the voids wider toward the bottom from the root of the negative electrode ear of the strap portion, the strap is made to have a void along the side surface of the negative electrode ear, as compared with a strap having a structure. The decrease in strength can be suppressed, and moreover, by setting the void width at the lowermost part to 60 μm or more, sufficient diffusion of the electrolytic solution can be secured as described above, and an excellent corrosion prevention effect on the negative electrode ear can be obtained.

FIG. 3 is a cross-sectional view of an essential part showing a second embodiment of the present invention, in which 1 is a negative electrode ear, 2 is a strap, 3 is a mutual dissolution layer, 4
Is a heat-affected layer, and 5b is narrow in the upper part, which is a feature of the present invention,
A void having a structure with a two-step width widened in a half thickness portion of the strap, and 6 are electrolytic solutions, respectively.

As described above, the structure having the two-step width makes it possible to obtain a strap having excellent vibration resistance while ensuring sufficient diffusion of the electrolytic solution, as in the first embodiment.

Next, in order to verify that the thickness of the negative electrode ear, which is the claim of the present invention, is required to be 0.6 mm or more,
D3 specified in JIS D 5301 for automotive batteries
Regarding the strap having the void shape of Example 1 in the 1-type lead storage battery, the negative electrode ear thickness was 0.4, 0.6, 0.8,
A battery having a thickness of 1.2 mm was manufactured, and the vibration resistance was evaluated based on the vibration conditions specified in the JIS. As a result, it was revealed that when the thickness of the negative electrode ear is less than 0.6 mm, there is a problem in the vibration resistance of the strap even in the void having the above shape.

Furthermore, in order to verify that the thickness from the tip of the void to the upper part of the strap, which is another claim of the present invention, is 2 mm or more, the D31 specified in JIS D 5301 of the automobile battery is similarly performed as described above. Regarding the lead-acid battery, the strap having the void shape of Example 1 has a thickness from the tip of the void to the upper portion of the strap of 1.6.
Batteries with different thicknesses of 1.8.2.0, 2.2 and 2.4 mm were manufactured, and the vibration resistance was evaluated based on the vibration conditions specified in the JIS. As a result, when the thickness from the tip of the void to the upper part of the strap is less than 2 mm, the vibration test cannot be endured, and a battery in which the negative electrode ear is broken from the strap occurs, and the thickness from the tip of the void to the upper part of the strap is reduced. It became clear that 2 mm or more is necessary.

[0026]

As described above, the negative electrode ear is used as a measure to prevent the negative electrode strap from corroding when the amount of the electrolytic solution is reduced and the negative electrode strap portion is exposed, or to a storage battery that does not have a fluid such as a control valve type lead storage battery. It is effective to provide a space between the side surface of the strap and the strap, but it has a drawback of poor vibration resistance. On the other hand, in the present invention, by providing a void that spreads downwards or a void having a two-step width, the anti-corrosion effect of the negative electrode strap due to the void is maintained, and the vibration resistance is also reduced. Suppress and also
When the thickness of the negative electrode ear is 0.6 mm or more and the thickness from the tip of the void to the upper part of the strap is 2 mm or more, the vibration resistance can be further enhanced and its industrial effect is great.

[0027]

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a strap showing an example of a conventional product.

FIG. 2 is a cross-sectional view of a main part of the strap showing the first embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a strap showing a second embodiment of the present invention.

[Explanation of symbols]

1 negative ear 2 straps 3 Mutual dissolution layer 4 Heat affected layer 5 Void 5a Void of Example 1 of the present invention 5b Void of Example 2 of the present invention 6 Electrolyte

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tetsuro Minato             Kyoto Prefecture Kyoto City Minami-ku Kichijoin Nishinosho Inono Babacho             No. 1 within Japan Battery Co., Ltd. F term (reference) 5H022 AA01 BB11 CC15 CC19 CC23                       CC30 EE02 KK07

Claims (4)

[Claims] 1. A lead storage battery comprising a strap formed by collectively welding a plurality of negative electrode ears, wherein a void is formed which expands downward from a root portion of the negative electrode ear of the strap portion, and the maximum portion of the void is provided. Is 60 μm or more, a lead-acid battery. 2. A lead storage battery comprising a strap formed by collectively welding a plurality of negative electrode ears, wherein a void having a width of two steps is provided along a side surface of the negative electrode ear from a root portion of the negative electrode ear of the strap portion. A lead-acid battery characterized in that the width of the widest part is 60 μm or more. 3. A lead acid battery comprising a strap formed by collectively welding a plurality of negative electrode ears, wherein the thickness of the negative electrode ears is 0.6 mm or more. Lead acid battery. 4. A lead storage battery comprising a strap formed by collectively welding a plurality of negative electrode ears, wherein the thickness from the tip of the void to the upper part of the strap is 2 mm or more. The lead acid battery according to claim 2 or claim 3.