JPH0511317U - Lead acid battery - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the occurrence of sparks due to corrosion breakage of straps. [Structure] An upper surface of a liquid-retaining porous plate 3 such as a separator or a glass mat interposed between a positive electrode plate 1 and a negative electrode plate 2 and a lower surface of a strap 6 are brought into contact with each other. The spark is generated when the strap is broken because the closed loop during energization is momentarily interrupted. In order to prevent the occurrence of sparks, a resistor or a capacitor may be connected in parallel at the breaking point of the strap. The liquid-retaining porous plate contains sulfuric acid and also functions as a conductor. By extending and enlarging the liquid-retaining porous plate upwards until it touches the lower surface of the strap 6, even if the liquid surface drops and the strap 6 is ruptured in an exposed state, the electrolytic solution contained in the separator electrically Since the conductive state is maintained, no spark occurs.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to the structure of lead acid batteries.

[0002]

[Prior art]

 As shown in FIG. 1, the basic structure of a conventional lead storage battery is that positive electrode plate 1 and negative electrode plate 2 are alternately stacked with a separator 3 interposed therebetween, and ears 4 and 5 of each electrode plate are connected by a lead alloy. A strap 6 is formed and welded to a pole, and the strap 6 is housed in a battery case 7, a lid 8 is attached, and an electrolytic solution is injected to a predetermined height 9. This unit cell has a voltage of about 2 V and is used by connecting a plurality of unit cells in series to obtain a required voltage. For example, in a vehicle battery, a 6V monoglock battery case is used to form 6 cells in series to form a 12V battery. The outline is shown in FIG.

[0003]

[Problems to be solved by the device]

Such a lead storage battery has a property that during use, electrolysis of water occurs due to overcharge, the water content in the electrolytic solution decreases, and the electrolytic solution surface 9 lowers. In actual use, remove the liquid port plug, which also functions as an exhaust device, to refill water so that it does not fall below the minimum allowable liquid level. However, in the case of neglecting replenishment of water or significant overcharging due to imbalance between charging and discharging, the liquid level 9 becomes lower than the minimum allowable height, and the strap can be used in an exposed state. In such a state, the strap portion 6 is likely to be locally corroded by an electrochemical reaction or a chemical reaction during charge / discharge. If this continues for a long period of time, corrosion will progress and the strap will break. If the rupture of the strap 6 occurs during energization, a spark may be generated, which may cause a flammable explosion of the surrounding H ₂ gas.

Normally, such corrosion rupture is not a problem because the life of the electrode plate and the like is exhausted before it occurs. The strap 6 is designed to suppress the occurrence and progress of strap corrosion depending on the alloy type, shape, welding method, and the like. However, under severe operating conditions, which are not normally assumed, corrosive fracture of the strap 6 may occur. For example, in an automobile using a 12V lead-acid battery as shown in Fig. 3 in which six single cells are connected in series, the temperature inside the bonnet has recently been raised. If a lead-acid battery is used at high temperature, the overcharge current increases, resulting in overcharge heat generation, which raises the battery temperature and further overcharge, which leads to a vicious cycle and accelerates the drop in the liquid level. Corrosion at high temperature is accelerated according to Arrhenius' law.

Even under the above-mentioned circumstances, it is desirable that the storage battery does not cause any abnormality and is used safely until the end of its life. The present invention has been made to solve the above problems, and an object thereof is to provide a lead storage battery capable of preventing the generation of sparks even when the strap is corroded and broken. It is in.

[0006]

[Means for Solving the Problems]

 Therefore, the present invention solves the above problems by using a lead storage battery in which the upper surface of a liquid-retaining porous plate such as a glass mat and the lower surface of a strap are in contact with each other. Is. In the present invention, the upper and lower sides of the upper surface of the liquid-retaining porous plate and the lower surface of the strap are relative to each other, with the storage battery bottom side being the bottom side and the storage battery lid side being the top side, when the storage battery is installed normally. And

[0007]

[Action]

 In the conventional lead-acid battery, sparks are generated when the strap is broken because the closed loop during energization is momentarily interrupted. To prevent this, a resistor or capacitor should be connected in parallel at the breaking point of the strap. The present invention focuses on this point and aims to achieve it by using an electrolytic solution. As can be seen from the above description, the separator is always interposed between the positive and negative electrode plates of the lead storage battery. This separator is a microporous sheet or a liquid mat such as a glass mat in contact therewith, always contains an electrolytic solution (dilute sulfuric acid), and also functions as a conductor. If this is extended and expanded upward until it touches the lower surface of the strap 6, even if corrosion breaks when the liquid level drops and the strap 6 is exposed, it is electrically conducted by the electrolyte solution contained in the separator. Since the state is maintained, no spark will occur.

[0008]

【Example】

 FIG. 2 is a sectional view of a lead-acid battery showing an embodiment of the present invention. In the figure, 6 is a strap and 3 is a separator. In addition, the same reference numerals as those in FIGS. 1 and 3 represent the same functional parts. The upper surface of the separator and the lower surface of the strap are in contact with each other. Since the separator 3 always exists between the positive and negative electrode plates, if it is brought into contact with the strap 6, no spark will occur even if the strap is broken at any part or at a plurality of places. It is not uncommon to add parallel connections in other ways.

A battery having such a structure uses, for example, a separator 3 which is taller than a conventionally designed battery, and after a strap 6 is welded, it is displaced until it comes into contact with the separator and the strap by an appropriate method. Alternatively, it may be obtained by assembling a general electrode plate assembly with a liquid-retaining porous plate on the upper part of the separator and abutting the strap and the upper part of the separator.

[0010]

[Effect of the device]

 As described above, according to the present invention, even if the strap is broken when the liquid level is lowered, the spark can be prevented with a relatively simple structure.

[Brief description of drawings]

FIG. 1 is a diagram showing a single cell structure of a conventional general lead-acid battery.

FIG. 2 is a view showing a single cell structure of a lead storage battery according to an embodiment of the present invention.

FIG. 3 is a view showing a structure of a conventional general lead acid battery for an automobile.

[Explanation of symbols] 1 positive electrode plate 2 negative electrode plate 3 separator 4 positive electrode plate ears 5 negative electrode plate ears 6 straps 7 battery case 8 lid 9 electrolyte surface level 10 exhaust device / liquid port plug 11 storage battery bottom surface

Claims (1)

[Claims for utility model registration] 1. The upper surface of the liquid-retaining porous plate 3 such as a separator or a glass mat interposed between the positive electrode plate and the negative electrode plate is brought into contact with the lower surface of the strap 6. Lead acid battery.