JPH0449754B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to improvements in sealed lead-acid batteries.

Conventional configurations and their problems In recent years, sealed lead-acid batteries, which are used as power sources for portable equipment such as portable VTRs, are more likely to deform their containers due to heat generation than conventional lead-acid batteries. For example, these causes include the requirement for rapid charging with a large current, overcharging due to charger failure, and inadvertent short-circuiting between the positive and negative terminals. For this reason,
It has become necessary to ensure safety against heat generation and prevent deformation of batteries, and small thermostats have come to be used as protection devices.

On the other hand, the diversifying needs of users of devices such as portable VCRs, such as demands for power supplies that are heavy but have long operating times, or light and easy to carry even though short operating times, have led to On the other hand, there is a growing demand for sealed lead batteries with the same external dimensions but different capacities and battery weights. A conventional battery configuration will be described below.
Figure 1 and Figure 2, which is a sectional view along plane A.
In the figure, 1 is a positive electrode plate, 2 is a negative electrode plate, and 3 is a separator mainly made of glass fiber, and these, two positive electrode plates, and three negative electrode plates constitute an electrode plate group 4. This is inserted into each cell chamber 6 of a battery case 5 made of acid-resistant resin to form a battery with a nominal voltage of 12V. The thermostat 8 is arranged in a dedicated storage chamber 7 at right angles to the end faces of the electrode plates constituting the electrode plate group 4. In this conventional example, in order to change the capacity and weight while keeping the external dimensions of the cell 5 the same, as shown in the sectional view of FIG. It is necessary to adjust the area using the partition 9. For this reason, it was necessary to create a new mold for resin-molding the battery case. Furthermore, in a battery case in which a partition 9 is provided inside the cell chamber, heat generated from the negative electrode plate is diffused by the partition 9 and side walls of the battery case during overcharging.
There was a tendency that the heat was not easily transmitted to the thermostat 8 and the heat sensing ability was weak. In addition, there was also the disadvantage that the cost for manufacturing the container mold increased, raising the product cost.

Purpose of the invention The present invention solves the above-mentioned conventional drawbacks,
The thermostat uses a plastic battery case with the same external dimensions that is compatible regardless of the battery capacity, and a spacer made of a group of electrode plates and a closed-cell foamed synthetic resin is installed inside each cell chamber. The purpose is to provide a highly safe sealed lead-acid battery at a low price by increasing the heat sensing ability of the thermostat by facing the electrode plates in the cell chamber through the partition of the battery case.

Structure of the Invention The present invention provides a sealed lead-acid battery in which a thermostat is installed inside a storage chamber of a battery case, in which a spacer made of independently foamed acid-resistant resin is installed inside the cell, and is placed in contact with the spacer to adjust its height. It is characterized in that a group of small electrode plates with different dimensions such as thickness are inserted into the cell to share a battery case. By configuring the battery as described above, it is possible to reduce the weight and capacity of the battery depending on the application while keeping the external dimensions the same, and by utilizing the heat insulating effect of the closed foam resin, the temperature of the battery's heat generation can be reduced. This ensures improved heat transfer to the thermostat.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. 4 and FIG. 5, which is a sectional view taken along plane B thereof.
Note that the same components as in the conventional example are given the same reference numerals and their explanations will be omitted. In the case of this example, a positive electrode plate 1 and a negative electrode plate 2 with electrode plate dimensions of 40 mm width x 30 mm height are separated by a separator 3 mainly made of glass fiber to serve as the electrode plates, and the electrolytic solution is dilute sulfuric acid. This is a so-called retainer type lead-acid battery that is impregnated with
Six electrode plate groups 4 are lined up together with spacers 10 in the direction shown in FIG. 4, inserted into each cell chamber 6, and 12V
It was used as a specified battery. A small storage chamber for installing a thermostat 8 is provided at one end of the battery case 5, and the thermostat 8 is placed in this storage chamber so as to face the electrode plate group 4 through a partition 5'.
The heat generated from the negative electrode plate can be sensed well. The spacer 10 installed below the electrode plate group 4 shown in the figure for dimension adjustment and insulation inside the battery case has a spacer of 10 to 15
Expanded polystyrene, which was made to double as an independent foam, was used.
FIG. 6 shows a cross section of another embodiment of the present invention, in which a block-shaped spacer 10 is arranged so as to face the thin electrode plate group 4. Note that the thermostat 8 faces the end face of the electrode plate group 4 with a partition 5' interposed therebetween.

Next, fully charge the battery shown in Figure 2 as a, the battery shown in Figure 3 as b, the battery shown in Figure 5 as an example of the present invention as c, and the battery as shown in Figure 6 as d. Prepare a battery in the same condition and heat it at an ambient temperature of 50℃.
Figure 7 shows the results of overcharging with a current equivalent to 1.5C. As is clear from the figure, in the batteries c and d according to the present example, the insulation effect of the polystyrene foam with high magnification prevents or suppresses heat conduction to unnecessary parts, and the heat generated from the negative electrode plate due to overcharging is quickly blocked off by the partition 5. can be transmitted to the thermostat 8 via '. Therefore, it can be seen that this method is very effective in preventing deformation of the battery. Furthermore, since the spacer also exhibits an effect as a shock absorbing material, it is possible to improve safety against shocks caused by dropping the battery or the like.

Effects of the Invention As described above, according to the present invention, in a sealed lead-acid battery equipped with a thermostat inside the battery case, a spacer made of independently foamed acid-resistant synthetic resin is installed in each cell chamber together with a group of electrode plates. This makes it possible to share the battery case, improve the heat sensing ability of the thermostat which increases the safety of the battery due to the heat insulating effect of the spacer, and make it effective as a shock absorbing material. Furthermore, since there is no need for mold investment and mold manufacturing time for a new battery case, it is possible to obtain the excellent effect of being able to provide inexpensive batteries in a short period of time.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a conventional sealed lead-acid battery;
The figure is a sectional view taken along plane A in FIG. 1, FIG. 3 is a sectional view showing another conventional sealed lead-acid battery, and FIG. 4 is a perspective view of a sealed lead-acid battery according to an embodiment of the present invention. Figure 5 is a sectional view along plane B of Figure 4;
The figure is a cross-sectional view of a battery in another embodiment of the present invention.
FIG. 7 is a characteristic diagram showing the relationship between overcharging and temperature rise. 4... Plate group, 5... Battery case, 5'... Battery case partition, 6... Cell chamber, 7... Thermostat storage chamber, 8... Thermostat, 10... Independent foaming. Spacer made of acid-resistant synthetic resin.

Claims (1)

[Claims] 1. A battery case made of acid-resistant resin is provided with a plurality of cell chambers and a thermostat storage chamber smaller than the cell chambers, and a spacer made of independently foamed acid-resistant synthetic resin is brought into contact with a group of small electrode plates to house the battery. A sealed lead-acid battery characterized in that the thermostat is installed in each cell chamber of the tank, and the thermostat in the thermostat storage chamber is opposed to a group of electrode plates in an adjacent cell chamber through a partition of the battery container.