JPS5832461B2 - Manufacturing method of leak-free storage battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a so-called non-leakage storage battery that does not leak electrolyte even if it falls over, and particularly relates to a method for liquid-tightly fixing a pot-shaped filter around the lower surface of an exhaust hole of a lid. .

In order to fix the filter to the lid made of thermoplastic synthetic resin, for example, the filter is heated in advance to a temperature higher than the temperature at which the resin melts, and then the filter is pressed against the lid and the lid is melted and fixed by the heat, or There are methods such as fixation using ultrasonic embedding methods.

However, in the former case, when the filter is heated, the water repellent material such as silicone is destroyed at the same time, making it difficult to maintain strong water repellency.

In addition, in the latter case, since the filter is made of fine particles of alumina oxide mixed with a frit-related binder and sintered, the bonding strength is inherently weak, and as a result, it may crack due to ultrasonic vibration. There were drawbacks such as.

The present invention eliminates all the above-mentioned conventional drawbacks, and this will be explained with reference to the drawings of the embodiment. and 2 are a container and a lid made of thermoplastic synthetic resin such as polypropylene, which are fixed at a joint 3 by a method such as heat sealing.

Reference numeral 4 denotes a group of electrode plates consisting of positive and negative electrode plates, separators, etc. The positive and negative electrode plates are connected by straps 5 and 5', respectively, and are connected to terminals 7 and 7' through poles 6 and 6'. .

8, 8' are bushings integrally molded in advance on the lid 2, and 9 is an electrolyte.

The lid 2 has an exhaust hole 10 in the center thereof, and a pot-shaped filter 11 is fixed liquid-tightly at a fixing part 12 and hangs around the lower surface thereof.

The relationship between the surface area of the filter 11 and the electrolyte solution 9 is such that no matter what state the storage battery falls over, a part of the surface area of the filter is always exposed above the electrolyte surface.

The filter 11 is made of a porous body made by adding a frit-related binder to fine particles of alumina oxide and sintering the same.
This is coated with a water repellent material such as silicone, giving it strong water repellency.

As mentioned above, the filter 11 hangs down from the center of the lid 2, so that no matter how the storage battery falls over, a portion of the surface area of the filter 11 is always exposed above the electrolyte surface. In addition, since the filter is shaped like a pot, the thickness of each part is the same, so the ventilation resistance value is also the same.Furthermore, the filter is treated with a strong water repellent treatment, so the filter's thickness is the same. The part immersed in the liquid repels the penetration of the liquid due to the surface tension created by the water-repellent treatment.
On the other hand, surface tension does not work on the parts exposed above the liquid surface, so gas can pass through them quickly.

Therefore, even if it falls over in any condition, no liquid will leak, and only the exhaust gas will be quickly discharged.

In this manufacturing method, the electrode plate group, etc. will be manufactured as appropriate using conventional methods, so a description thereof will be omitted.However, as the method of fixing the filter to the lid is the most distinctive feature of the present invention, this will be described below. The details will be explained below.

Figures 2 and 3 show the first embodiment, and Figure 2 shows the surface of the lid 2 that is located around the exhaust hole 10 in the center of the lid 2 and on the inside of the storage battery (the upper surface in the figure). A rib 13 is provided on the surface), and the flat surface 15 of a heat mirror 14 equipped with a heating element such as a cartridge heater is brought into direct contact with the tip 16 of the rib to melt a portion of the rib tip 16 as shown in the figure.

At this time, if the material of the lid is polypropylene, the heat mirror 14 is heated to a temperature of 380 to 4000 C and brought into contact for about 4 seconds.

After that, the heat mirror 14 is removed, and the tip 1 of the rib 13 is
6 is still in a molten state, the upper edge 17 of the filter 11 is press-fitted into the molten portion as shown in FIG.

At this time, the upper edge 17 of the filter digs deeply into the melted portion, and a portion of the melted rib also penetrates into the pores of the filter, so that the filter 11 is firmly and closely fixed to the lid 2.

4 and 5 show a second embodiment, and the difference from the first embodiment is that a protrusion 19 is provided on the heat mirror 18 in a portion corresponding to the rib 20 of the lid 2. The grooves 21 are formed by melting the ribs 20 using the protrusions.

The width of this groove 21 is made narrower than the thickness of the upper edge 23 of the filter 22, and after the heat mirror 18 is removed, when the groove 21 is still in a molten state, the filter 21 is opened as shown in FIG. The upper edge 23 of 22 is forcefully inserted and press-fitted.

In this way, the upper edge 23 of the filter can be wedged into the rib 20 to an arbitrary depth, resulting in an even stronger fixation.

If a lid with a filter fixed thereto is obtained by such a manufacturing method, this lid is attached to the battery case 1 into which the electrode plate group 4 is inserted.
and join them at the joint part 3 using a conventional method such as a heat sealing method,
On the other hand, the pole 6.6' inserted into the hole in the bushing 8°8'
A non-leakage storage battery is completed by melting the terminals 7° and 7' integrally with the bushing at the upper surface of the bushing.

To explain the function and effect of this, the filter can be firmly fixed to the lid at room temperature, so there is no negative effect on the water repellent function.

In addition, there is no need to apply strong stress such as ultrasonic vibration to the filter that can destroy the filter.
No cracks will occur at all.

Furthermore, as mentioned above, the upper edge of the fold-down filter is forcefully inserted into the melted lid material, but some of the melted lid material also penetrates into the intricate pores of the filter, making it very strong. A fixed state is obtained.

Therefore, according to the method of the present invention, the filter does not need to be formed into a complicated shape by providing a flange on its upper edge etc. to prevent it from coming off, and can be formed into the simplest pot shape. Another advantage is that filter production is easy.

As mentioned above, the present invention eliminates all the drawbacks of the prior art, and also has remarkable effects that cannot be expected from the prior art, and its industrial value is enormous.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional side view of the essential parts of a non-leakage storage battery obtained by the method of the present invention, and Figs. Fig. 2 is a vertical side view showing a state in which the ribs of the lid are melted by a heat mirror in the first embodiment, and Fig. 3 is a longitudinal side view showing a state in which a filter is pressed and fixed to the melted part. FIGS. 4 and 5 are longitudinal sectional side views of the second embodiment, showing states corresponding to FIGS. 2 and 3, respectively. 2: Lid, 10: Exhaust hole, 11: Filter 17: Upper edge of filter, 21: Groove.

Claims (1)

[Scope of Claims] 1. A drop-shaped filter is suspended from approximately the center of the lower surface of the lid, so that no matter how the storage battery falls over, a part of the surface area of the filter is always exposed above the electrolyte surface. In the manufacturing method of liquid storage batteries, the ribs provided on the lower surface of the exhaust hole of the lid made of thermoplastic synthetic resin are melted in advance, and then the upper edge of the drop-shaped filter is press-fitted into the melted part and fixed in a liquid-tight manner. A method for manufacturing a leak-free storage battery characterized by: 2. The method for manufacturing a leak-free storage battery according to claim 1, wherein the rib provided on the lower surface of the exhaust hole of the lid is melted into a groove shape whose width is narrower than the thickness of the upper edge of the pot-shaped filter.