JPH05225967A - Lead-acid battery - Google Patents

Abstract

PURPOSE:To provide the well jointed state of a strap, and make a battery small and lightweight by using a plate having a lug tapered along the side wall of the strap. CONSTITUTION:After the recess section 7 of a mold 6 is filled with molten lead alloy, a preliminarily manufactured lug is immersed therein. A strap after formed due to the solidification of the molten alloy, is taken out from the mold 6. In this case, tapered parts 3 and 3' along the inner walls 8 and 8' of the mold 6 are formed on a lug section 2 and, therefore, gaps 9 and 9' of certain sizes exist between the section 2 and the inner walls of the mold 6. Consequently, the molten lead alloy flows well and the strap of uniform thickness can be formed. Also, no defective welding due to an insufficient molten lead alloy flow does not take place. In addition, there is a sufficient amount of the molten lead alloy around the corners 10 and 10' of a lug end, and the corners 10 and 10' are easily melted, thereby obtaining a good jointed condition. Namely, the lug section 2 is so shaped as to have the tapered parts 3 and 3' along the side wall of the strap, and formed with a cast-on-strap method. Thus, the strap in a good jointed condition can be obtained, and a battery can be made safe, small and lightweighted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead acid battery, and more particularly to a lead acid battery having a strap formed by a cast-on-strap method.

[0002]

2. Description of the Related Art One of the methods for forming a strap of an electrode plate group of a lead storage battery is to inject lead or lead alloy molten metal into a mold having a recessed portion, and to plate the electrode plate in the lead or lead alloy molten metal. There is a so-called cast-on-strap method, in which the ear plate is dipped to produce the electrode plate group. This method is suitable for application to automated equipment and is used in the production of mass-produced automobile batteries, and has recently come to be used in the production of forklift batteries and the like.

For lead-acid batteries, there has been a strong demand for weight reduction, and as one of the means therefor, a device for making the strap forming the electrode plate group as small as possible has been devised.

In order to reduce the size of the strap, a method of reducing the thickness is generally used. However, since the amount of the molten lead which is injected into the concave portion of the mold when forming the strap is small, the electrode to be immersed for joining is reduced. There is a possibility that the margin of melting of the plate ear portion is small and the welded portion is reduced, resulting in an insufficiently welded strap. When the thickness of the strap portion is further reduced, the length of the electrode plate ear portion to be soaked is shortened, and when the electrode plate and the separator are stacked, the electrode plates become misaligned,
It is also possible that the ears of the electrode plate are only slightly dipped in the molten lead or not at all.

Another method for reducing the size of the strap is to narrow the width of the strap. However, if the width of the strap is narrowed, when the electrode plate ear is immersed in the lead or lead alloy molten metal, the gap between the mold and the ear becomes very narrow, and the molten area of the lead or lead alloy molten metal deteriorates. The joint between the ears and lead or lead alloy may deteriorate.

When the electrode plate ears are not welded in a sufficiently good condition in the strap, the electrode plate ears may come off the strap or the strap may be damaged due to vibration during use of the battery. become. In this case, not only the discharge capacity will be reduced, but also the electrode ears that come off the strap and the strap may come into contact with the strap while the battery is in use, causing a spark, which may ignite the gas in the battery and cause an explosion. There is even.

It is an object of the present invention to eliminate the above-mentioned drawbacks and to provide a safer and lighter lead-acid battery having a strap in a good joined state.

[0008]

SUMMARY OF THE INVENTION The present invention provides a lead-acid battery in which a strap is formed by the cast-on-strap method, by providing a taper ear along the side wall of the strap so that the strap is in a good joined state. In addition, a small and lightweight lead acid battery is obtained.

[0009]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing a strap portion of the lead acid battery of the present invention. In FIG. 1, 1 is an electrode plate, 2 is an ear part, and 2 is an ear part.
The taper 3 along the side walls 5, 5'of the strap 4,
3'is attached. As shown in the schematic view of the strap portion of the conventional lead-acid battery, as shown in FIG. 4, no taper is observed at the ears of the electrode plate.

FIG. 2 is a diagram for explaining a method of forming the strap of the lead acid battery of the present invention. First, as in the conventional case, the ears are cut into ears of a predetermined length, the ears are cleaned by brushing, and then the flux is applied and dried. Then, after filling the concave portion 7 in the mold 6 with the molten lead alloy, the ear is dipped. After the lead alloy melt is solidified to form the strap, it is taken out from the mold 6. At this time, the inner walls 8, 8'of the mold 6 are tapered so that the straps can be taken out easily.

In the case of the present invention, since the ears 2 are provided with the taper 3 and 3'according to the inner walls 8 and 8'of the mold 6, a certain degree of clearance is provided between the ears and the inner wall of the mold. There are 9,9 '. As a result, the molten lead alloy melts well, a strap with a uniform thickness is formed, and welding defects due to insufficient molten metal do not occur. Further, there is a sufficient amount of the lead alloy molten metal around the corners 10 and 10 'of the ear tips, and the corners 10 and 10' are also easily melted to obtain a good joined state.

It should be noted that the electrode plate was used after being aged and dried after the casting grid was filled with paste, but when the grid was cast by devising the engraving of the grid mold,
The electrode plate ears 2 are provided with tapers 3 and 3 '.

On the other hand, when the conventional lead-acid battery strap is formed by the cast-on-strap method, the gaps 11 and 11 'between the ears and the inner wall of the mold are very narrow as shown in FIG. May worsen, the amount of hot water may decrease, the ears may not be melted so much, and as a result, poor welding may occur. In addition, there is not a sufficient amount of the molten lead alloy around the corners 10 and 10 'of the ear tips, so that the molten alloy becomes difficult to melt, and defective welding is likely to occur.

Further, when the ears 2 are put into the recessed portions 7 of the mold 6, if the positions are slightly displaced, the corners 10 and 10 'of the ears abut against the inner walls 8 and 8'of the mold 6, and the corners 10 and 10'. The area around the corner did not melt, and when I looked at the strap taken out from the mold 6
A narrow gap may be observed near 0,10 '. When such a narrow gap is generated, it is considered that the battery is likely to be corroded when the battery is used, and the strength of the strap is also reduced.

In the present embodiment, the ears are tapered by engraving the lattice mold, but in the case of the expanded lattice which has been widely used recently, the shape of the punching die is changed when punching the ears. By doing so, the taper can be easily attached.

Not only the method described here but also the formation of the strap by the cast-on-strap method,
If the ears are tapered in some way, the lead-acid battery of the present invention can be obtained.

Incidentally, FIG. 3 shows a schematic view of a strap portion of a lead storage battery according to another embodiment of the present invention. In FIG. 3, the taper 3 and 3'which are larger than those shown in FIG. 1 are added, and the above-mentioned effect is more clearly exhibited.

[0018]

As described above in detail, in the lead storage battery according to the present invention, the ear has a tapered shape along the side wall of the strap, and the strap is formed by the cast-on-strap method. Thus, a safer, smaller and lighter lead-acid battery can be obtained, and its industrial value is very large.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a strap portion of the lead acid battery of the present invention.

FIG. 2 is a diagram for explaining a method of forming a strap of the lead acid battery of the present invention.

FIG. 3 is a schematic view showing another embodiment of the strap portion of the lead acid battery of the present invention.

FIG. 4 is a schematic diagram showing a strap portion of a conventional lead storage battery.

FIG. 5 is a view for explaining a method of forming a strap of a conventional lead storage battery.

[Explanation of symbols]

 1 electrode plate 2 ear part of electrode plate 3,3 'taper of ear part 4 strap 5,5' side wall of strap 6 mold 7 concave part 8,8 'inner wall of mold 9,9' gap 10,10 'of ear part Corner 11, 11 'gap

Claims (1)

[Claims] 1. A lead storage battery in which a strap is formed by the cast-on-strap method, wherein a lead storage battery using an electrode plate having ears tapered along a side wall of the strap is used.