JPS6246946B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a lead-acid battery, and more particularly, the present invention relates to a lead-acid battery, and more particularly, a separator arranged between electrode plates is formed into a U-shaped or bag-shaped bag having a U-shaped bent bottom. This invention relates to an improvement in a lead-acid battery having a structure in which at least one of the positive and negative electrode plates is surrounded.

Conventional Structures and Their Problems In general, lead-acid batteries have positive and negative electrode plates arranged alternately with separators in between. At this time, in order to ensure the amount of sulfuric acid on the positive electrode side and to suppress loosening of the plate active material, a structure was adopted in which a glass mat was placed on the positive electrode side of the separator, and on the negative electrode side, it was used to help diffuse the sulfuric acid from offshore. Alternatively, in order to prevent generated gas from accumulating between the electrode plate and the separator, a configuration is adopted in which the electrode plate has ribs parallel to the vertical direction.

Traditionally, pulp molded products and plastics have been used as this separator, and these are plate-shaped objects that are sequentially arranged in the order of a negative electrode, a separator, a glass mat, and a positive electrode as necessary, and are processed by a stacking process in which the electrode plates are aligned. A multi-plate electrode group has been constructed. However, in recent years, advances in processing technology for plastic porous materials have made it easier to form ribs into thin sheets and bend them, and it has also become possible to process them into bag shapes using ultrasonic waves and heat. Porous materials have been put into practical use. In this,
Parallel ribs are provided on a smooth sheet-like separator, the length direction of these ribs is arranged in the vertical direction of the electrode plates, and the lower part is bent into a U-shape so that at least one of the positive and negative electrode plates can be covered with one sheet. The wrapping structure has the advantage that drop-off from the plates is stopped at the bottom of the separator, thereby effectively reducing bottom short circuits. Furthermore, it is preferable to form a bag by sealing the side parts by heat welding or ultrasonic welding, except for the bent part at the bottom and the open part at the top, since this will prevent the active material from leaving the separator layer more completely. Particularly in recent years, there has been an increasing tendency to use expanded metal as electrode grids, but as is well known, expanded metal has a structure in which roughly diamond-shaped meshes are arranged in a sequentially shifted manner.
When a rectangular electrode plate is constructed, a portion not surrounded by bone is formed at the cut portion, and there is a greater risk of the active material falling off during handling or use of the battery compared to conventional cast grids. Therefore, the method of using a separator with a closed bottom, preferably in the form of a bag, as described above becomes even more useful.

On the other hand, due to recent improvements in road conditions and improvements in electrode plate active materials, the need for glass mats is gradually fading away, and the use of a plate group configuration called pine-less is increasing, especially in automobile batteries. Since a large amount of sulfuric acid is required for the reaction, the positive electrode is made of porous plastic as described above.
Even if it is surrounded by a font or a bag-like object, an appropriate gap between the electrode plate and the inside is required. It is common to have ribs arranged side by side.
Further, when surrounding the negative electrode, it would be possible to provide a structure in which a few ribs are similarly provided on the negative electrode side to improve degassing properties, and a mat body is provided on the positive electrode side.

In any case, it is necessary to bend the bottom part into a U-shape and provide a rib body on the inside of the U-shape under the structure.

However, a problem arose in the structure in which the ribs were provided on the inside of the U-shape or, as a variation thereof, on the inside of the bag-like shape. In other words, since a smooth surface appears on the outside, a smooth surface appears at the bent bottom.

In this structure, when the electrode plate is inserted inside and handled, the smooth portion may be worn out or scratched by rubbing against other objects. Another problem is the stacking process, in which at least one of the positive and negative electrodes is surrounded by the above-mentioned U-shaped body or bag-like object, and the positive and negative electrodes are arranged alternately. is applied, and at this time, unlike when stacking plate-shaped separators, the load of the heavy electrode plates is applied, so there is a high risk of damage such as fraying of the smooth part at the bottom of the U-shaped body.

In other words, such bottom damage was originally caused by U
This has become a major cause of impeding the purpose of forming the bag-like shape, which is to prevent falling materials from falling off.

OBJECT OF THE INVENTION The present invention provides a concrete solution for suppressing the above-mentioned problems.

Structure of the Invention The present invention provides, in the bottom bent portion of the separator,
It is characterized in that a protrusion is formed on the outside of the U-shaped body in correspondence with the position of the rib arranged on the inside of the U-shaped body. This protrusion can be formed by adding a protrusion at the lower end of the bottom to the outside of the bent part, or by providing a protrusion in advance and bending it.
Most effectively, the ribs that protrude on the inside of the bend are strongly pressed against the outside of the bend, and the part containing the ribs is bent from the bend line of the flat part at the bottom. It is to make it protrude downward.

When the protrusion is formed in this way, what is exposed at the bottom of the electrode plate group when the electrode plate group is aligned is:
It is not a flat plate part but a protruding part, and the flat plate part is recessed slightly inside the outer periphery. Therefore, there is no danger that the thin lower end flat part used to trap fallen active material during stacking will come into direct contact with the jig, and the part that comes into contact with it will be a thick part where ribs exist, so there will be some friction. The risk of damage to the entire bottom is reduced.

In addition, this structure greatly improves stability in various processes in which electrodes surrounded by separators are handled. For example, when storing many electrodes in a pile, other jigs and tools may slightly touch the bottom side of the electrode plate. Even if this happens, there is very little risk of damage to the bottom of the separator.

As described above, the present invention provides a separator having a series of parallel ribs, which has a substantially U-shape (including V-shape) with the bottom of the electrode plate as the bending line and the ribs as the inside.
In a battery configuration in which the electrode plate is surrounded or is used in the form of a bag, by providing a protrusion to the outside at a position corresponding to the inner rib of the bottom part,
It mainly prevents the smooth part of the thin separator from being damaged during the manufacturing process, which in effect makes it possible to maximize the original purpose of the U-shaped separator structure to prevent bottom short circuits. In other words, the reliability of the battery is improved.

DESCRIPTION OF EMBODIMENTS Hereinafter, features of the structure of the present invention will be explained with reference to embodiments.

FIG. 1 shows an example of a lead-acid battery to which the present invention is applied, in which 1 is a positive electrode plate, and 2 is a separator made of a polyethylene porous body with a protrusion formed at the bottom and the bottom bent into a U shape. , the inner side has ribs 3 perpendicular to the electrode plate. The side portion 4 is welded by ultrasonic welding and encloses the positive electrode plate in a bag-like manner. If it is necessary to wrap the negative electrode, it can be wrapped in the same way, and if there is no need to weld the sides, the structure is simply bent. In any case, the structure of the lower end 5 of this bottom bent portion is important, and the outward protrusion 6 is present corresponding to the position of the inner rib.

FIG. 2 is an enlarged view of the portion 5, showing that the lower end of the protruding portion 6 is located below the smooth portion 7. In this example, instead of adding a new protruding member, a hard material was applied from the inside of the bent part, and the bent object was bent while applying a certain amount of tension to the rib inside the separator. This means bending while applying a load from the inside to the outside. Therefore, only the rib portion of the lower end, which should originally be smooth, is pushed outward, resulting in a protruding structure. This part is a strong part where the ribs are added and will not be damaged by some friction. The bending angle is arbitrary and the required R
may be provided, so that it will actually be more U-shaped than V-shaped.

The battery shown in FIG. 1 is constructed by a combination of the positive electrode plate protected by the separator thus obtained and the bare negative electrode plate. 9 is a battery container, and 10 is an electrolytic solution.

With this bag-like configuration or U-shaped configuration, the active material of the electrodes enclosed inside the separator virtually never comes out of the separator, so there is no short circuit at the bottom unless the bottom is damaged. It is also possible to configure a battery without providing a. In such a structure, there is a possibility that the bottom portion may rub, and the present invention exhibits even better effects.

On the other hand, when providing a saddle as usual, if the protrusion is placed above the saddle, it protects the smooth part from sliding, and if you do not ride on the saddle, the saddle and the protrusion engage, reducing the risk of side slipping. In either case, the effect of reducing the risk of damage to the lower part is provided.

Effects of the Invention As described above, the present invention extremely effectively exhibits the effect of a separator that includes electrode plates in a U-shape or bag shape, and improves the reliability of the battery.

By the way, when stacking electrode plates as shown in Figure 1 above, the defective rate due to damage to the lower part is approximately 1/100 compared to the conventional bent structure with a smooth lower end.
decreases to This is because the particles that fell off during stacking on the negative electrode side accumulate on the stacking jig and vibrate on top of it, which caused a lot of damage in the conventional structure, but the effect of the present invention is that it can be used in such cases. It is also greatly demonstrated.

[Brief explanation of the drawing]

FIG. 1 is a front view with main parts cut away of a lead-acid battery according to an embodiment of the present invention, and FIG. 2 is an enlarged view of the main parts of FIG. 1. 1... Positive electrode, 2... Separator, 3... Rib,
6...Protrusion.

Claims (1)

[Claims] 1. A separator having parallel ribs on one surface, bent into a substantially U-shape with the ribs on the inner surface, and surrounding the electrode plate with the length direction of the ribs arranged in the vertical direction of the electrode plate. and a lead-acid battery characterized in that, at the bottom of the separator, the outer side corresponding to the position of the inner rib of the bent separator protrudes further below the electrode plate than the part corresponding to the part without ribs. .