JP2002042765A - Sealed type lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate adhesion of a valve element and a valve presser plate on a safety valve part of a sealed type lead-acid battery and lowering of pressure of an opening and closing valve due to it and to improve precision of airtight inspection by reducing overflow of liquid in formation of a battery jar and improving visibility of a valve element top surface. SOLUTION: The cap type valve element 5 is installed on a valve cylinder part 3 formed on a battery jar cover 2 to cover a battery jar opening part to store an electrode plate group, the valve presser plate 6 is installed or connected to the electrode jar cover 2 so as to correspond to a top surface 5a of the cap type valve element 5, and a through hole 9 having length dimensions L more than outer diametrical dimensions (d) of the cap type valve element 5 and width dimensions (w) less than the outer diametrical dimensions (d) is provided on the valve presser plate 6 in correspondence with the top surface 5a of the valve element 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed lead-acid battery.

[0002]

2. Description of the Related Art Various configurations have been disclosed as safety valves for sealed batteries, particularly sealed lead-acid batteries. For example, a cap-shaped valve body is mounted on a valve cylinder portion configured as an exhaust valve mounting portion on a battery case lid as described in Japanese Patent Application Laid-Open No. 8-32295, and the valve body is raised by increasing the internal pressure of the battery case. In general, a structure in which a valve holding plate is provided on a top surface of a valve body at intervals so as not to come off.

On the other hand, the valve body is also used as a means for checking the airtightness inside the battery case. This is because when the airtightness in the battery case is maintained, the gas pressure in the battery case becomes lower than the atmospheric pressure due to the oxygen gas absorption reaction in the negative electrode active material, and as a result, the top surface of the valve body is deformed into a concave shape The phenomenon is actively used. In order to perform an airtight inspection in the battery case by utilizing this phenomenon, Japanese Patent Application Laid-Open No. H8-32295 described above discloses that the exhaust valve retainer lid, that is, the valve retainer plate is transparent enough to see through the top surface of the valve body. It is described to be composed of a certain material.

However, transparent materials are generally more expensive than opaque materials. The use of a vinyl chloride resin which is relatively inexpensive and has good transparency is not environmentally preferable.

In addition, as the battery is repeatedly charged and discharged, silicone resin oil applied between the valve body and the valve body, and sulfuric acid remaining on the valve body base penetrate into the top surface of the valve body. There is a phenomenon that the top surface of the valve body and the valve holding plate come into close contact with each other due to these liquid components, and the opening / closing valve pressure decreases. In order to avoid such a phenomenon, as shown in FIG. 4, a circular through-hole Y having an outer shape smaller than the outer diameter of the circular valve body X is provided in the valve holding plate Z at a position corresponding to the outer diameter of the valve body. Is being done.

However, when such a circular through hole Y is provided in the valve holding plate Z, the state of the top surface of the valve body X is very difficult to visually recognize, and the effect of facilitating an airtight inspection is impaired. I will. Further, even if the circular through-hole Y is provided, the outer peripheral edge of the top surface of the valve body X still has the valve holding plate Z over the entire circumference.
Therefore, there is a problem that the contact length between the valve body X and the valve cylinder becomes short, and as a result, the opening / closing valve pressure becomes lower than a specified value.

In general, in a sealed lead-acid battery, a so-called battery case formation, in which a battery is assembled with an unformed electrode plate and then injected to form a battery, is widely used. In such a formation process, it is usual to forcibly charge the battery with a relatively large current. As a result, oxygen gas and hydrogen gas are generated from the electrode plate group at the beginning and the end of the formation.

[0008] Such a gas is usually exhausted through a safety valve. However, since a relatively abundant electrolyte solution is present in the electrode assembly, the electrolyte solution is also mist or droplets with the gas exhaustion. Is discharged as Such an electrolytic solution condenses in the valve barrel to form a liquid reservoir for the electrolytic solution. In order to prevent such a liquid reservoir from being discharged out of the battery, see, for example,
Japanese Patent Publication No. 217597 describes a configuration in which a liquid absorbing sheet is provided between an inner lid and an upper lid. Although the electrolyte discharged from the valve cylinder portion is absorbed by such a liquid absorbing sheet and can suppress leakage outside the battery, the number of parts,
The structure was not preferable in terms of increasing the number of assembling steps. Although such an overflow of the electrolytic solution can be avoided by lowering the on-off valve pressure, the airtightness may be impaired when used for a long time in a market or the like.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem that the valve element and the valve holding plate adhere to each other at the safety valve portion of the sealed lead-acid battery and that the on-off valve pressure is reduced. And to provide a low-cost sealed lead-acid battery that reduces the amount of overflow during battery formation, improves the visibility of the top surface of the valve body, and improves the accuracy of hermetic inspection without compromising productivity. It is the purpose.

[0010]

According to a first aspect of the present invention, there is provided a valve cylinder formed on a battery case cover for covering a battery case opening for accommodating an electrode plate group. In a sealed lead-acid battery in which a valve body is attached to and a valve holding plate is attached to or joined to the battery case lid so as to correspond to the top surface of this valve body,
A through hole having a length dimension equal to or larger than the outer diameter dimension of the valve body and a width dimension less than the outer dimension is provided in the valve holding plate corresponding to the top surface of the valve body.

According to the above configuration,
The adhesion between the valve body and the valve holding plate can be prevented, and the top surface of the valve body can be easily visually recognized, so that the accuracy of the airtightness inspection can be improved.

According to a second aspect of the present invention, there is provided a sealed lead-acid battery having the configuration according to the first aspect,
An upper lid joined to the battery case lid is provided so as to cover the valve retainer plate, and the upper lid intersects the surface facing the valve retainer plate in the longitudinal direction of the through-hole and limits upward deformation of the valve retainer plate. This is a configuration in which projections are provided. The amount of displacement of the valve holding plate can be limited by this projection, and the opening / closing valve pressure can be increased. Conversely, since the opening / closing valve pressure in a state where the valve holding plate is mounted can be lowered, overflowing during the formation can be suppressed by performing the formation in this state. After the formation is completed, the opening / closing valve pressure can be easily increased by attaching the top lid, and the confidentiality of the safety valve when used for a long time in the market can be maintained, and the reliability of the battery can be improved. .

The invention described in claim 3 of the present invention is claim 1
Alternatively, in the sealed lead-acid battery having the configuration described in claim 2, the valve holding plate is opaque and has a color that cannot be seen through the valve element. According to the configuration of claim 1 or claim 2, since it is not necessary to see through the valve holding plate and visually check the state of the valve element, there is no need to use a transparent resin material that is not preferable in terms of cost or environment, It is possible to use a conventional opaque resin material which is inexpensive and has no adverse effect on the environment.

[0014]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention.
It is a figure which shows the principal part of the sealed lead storage battery by embodiment.

Reference numeral 1 denotes a battery case provided with a cell chamber 1a for accommodating a group of electrode plates (not shown), and has a structure in which a battery case cover 2 is joined. The battery case lid 2 is provided with valve cylinder portions 3 corresponding to the respective cell chambers 1a. The valve cylinder part 3 has the bottom surface of the concave portion 4 provided in the battery case cover 2 as a base surface.

A cap-shaped valve element 5 is mounted on the valve cylinder 3. As the valve 5, a synthetic rubber material such as chloroprene rubber or EPDM is generally used. In addition, the valve cylinder 3
A sealing agent such as silicone resin oil or fluorine-based resin grease is applied between the valve body 5 and the valve body 5, and the sealing agent permeates into minute gaps between the valve cylinder portion 3 and the valve body 5, so that both are airtight. Maintain their sexuality.

A valve holding plate 6 is mounted on the battery case cover 2. Figure 1
In the example, the valve holding plate 6 is fixed to the battery case cover 2 by fitting a fitting projection 8 projecting from the battery case cover 2 into a hole 7 provided in the valve holding plate 6. The valve holding plate 6 has a structure that collectively covers the plurality of valve elements 5 arranged in a line.

The valve holding plate 6 has a through hole 9 corresponding to the valve body 5.
Is provided. The through hole 9 has an elongated shape,
The length L in the long axis direction is longer than the outer shape d of the valve element 5, and the width w in the short axis direction is shorter than the outer diameter d of the valve element 5. With this configuration, the top surface 5 a of the valve body 5 is
Can be visually recognized in the diameter direction, and whether the top surface 5a is in a concave state or not can be accurately and reliably confirmed.

Further, the shape of the through hole 9 prevents the outer edge 5b of the top surface 5a from adhering to the valve holding plate 6 over the entire circumference.

Here, as shown in FIG. 1, the direction in which the through hole 9 is formed is the fixing portion of the valve holding plate 6 with the battery case lid 2, that is, the hole 7 and the fitting projecting portion 8 fitted in this hole. It is preferable to provide them substantially in parallel on a line connecting the portions. When the internal pressure of the cell chamber 1a increases due to charging, the valve element 5 moves toward the valve holding plate 6. At this time, portions corresponding to both sides of the through hole 9 of the valve holding plate 6 form a striated portion 6a, and the striated portion 6a is gently elastically deformed in an arc shape with the fixed portion as a fulcrum, and the valve body 5 This is because movement can be restricted. On the other hand, as shown in FIG. 2, when the through-hole 9 'is formed so as to intersect the major axis direction with the line between the fixed portions, particularly at a right angle, the width of the valve holding plate 6' is increased. In addition to the need to make the dimension T wider, bending stress is concentrated on the stress concentration portion 6b corresponding to the longitudinal end of the through hole 9 'of the valve holding plate 6'. Since the stress concentration portion 6b is broken by such bending stress, the configuration as shown in FIG. 2 is not preferable.

Next, an upper lid (not shown) is attached to the battery case lid 2 so as to cover the valve holding plate 6, whereby a sealed lead-acid battery of the present invention can be obtained.

(Second Embodiment) The sealed lead-acid battery according to the first embodiment shown in FIG. 1 is provided with an upper lid 10 in the second embodiment of the present invention shown in FIG. is there.
A projection 11 for limiting upward displacement of the valve holding plate 6 is provided on the valve holding plate 6 side of the upper lid 10. The projection 11 is provided so that its major axis direction intersects the through hole 9. The length f of the protrusion 11 in the long axis direction must be longer than the length w of the through hole 9 in the short axis direction. Since such a protrusion 11 restricts the upward displacement of the valve holding plate 6, by mounting such an upper lid 10, the opening / closing valve pressure can be kept high.

That is, in the state after the upper lid 10 is mounted, the opening / closing valve pressure increases compared to the stage before the upper lid 10 is mounted. Therefore, if the battery case formation is performed before the upper lid 10 is mounted, the opening / closing valve pressure is relatively low, so that the overflow during the formation charging can be suppressed. Then, if the upper lid 10 is joined to the battery case lid 2 after the formation, the on-off valve pressure value becomes higher,
The confidentiality of the valve body when the battery is used for a long period of time can be maintained.

Here, the reason why the protrusion 11 is formed as a means for suppressing the upward displacement of the valve holding plate 6 will be described in detail. The clearance between the upper surface of the valve holding plate 6 and the lower surface of the upper cover 10 when the upper cover 10 is mounted, that is, FIG.
The dimension of K shown therein is one of the important factors that determine the on-off valve pressure in the completed battery state. This is because the possible amount of deformation of the valve holding plate 6 is determined by this clearance amount.

In the present invention, the length of the protrusion 11 is the clearance K. Normally, the upper lid 10 and the battery case lid 2 are ultrasonically welded while applying pressure. In this welding process, the projection 11 is positioned when the projection 11 comes into contact with the valve holding plate 6 and welding is performed. It can be kept constant. At the same time, the projection 11 serves as a fulcrum of the linear portion 6a of the valve holding plate 6 together with the fixing portion between the valve holding plate 6 and the battery case cover 2 described above. When the valve body rises due to an increase in battery internal pressure, the valve presser plate is deformed in an arc shape between the fixed portion and the projection 11.

Therefore, the protrusion amount of the protrusion 11 may be determined according to the arc-shaped deformation amount and the required on-off valve pressure value. In addition, it is preferable that the length of the contact portion between the protrusion 11 and the striated portion 6a in the direction of the striated portion 6a be as short as possible so that the protrusion acts only as a fulcrum of the striated portion 6a. Therefore, it is preferable that the protrusion 11 be provided so as to be orthogonal to the linear portion 6a, that is, to be orthogonal to the long axis direction of the through hole 9.

When the major axis of the projection 11 contacts the filament 6a so as to be parallel to the filament 6a, most of the filament 6a is prevented from being displaced upward by the projection 11, and the opening / closing valve pressure value is reduced. Is unfavorably generated because of extremely high values.

Further, in the first and second embodiments, it is preferable to use an opaque material for the valve holding plate. The opaque material is inexpensive, and according to the configuration of the present invention, even if such an opaque material is used, the top surface 5
Inspection of the concave state of a does not cause any inconvenience.
In addition, there is no need to use a transparent vinyl chloride resin which had to be used due to a limitation in price in the past, which is environmentally preferable.

(Example of effect confirmation) An experiment for confirming the effect of the present invention was conducted. The experimental results will be described with reference to Examples 1 and 2 for confirming the following effects.

Example 1 of Effect Confirmation The sealed lead-acid battery according to the second embodiment is referred to as a battery A,
The sealed lead storage battery of the conventional example shown in FIG. 4 was referred to as a battery B, and the state of the safety valve was confirmed when both batteries were charged at a constant voltage of 2.3 V per cell for 4 weeks in a 60 ° C. atmosphere. As shown in FIG. 4, the battery B of the conventional example has a valve holding plate Z.
Is provided with a circular through-hole Y having an inner diameter smaller than the outer diameter of the valve body X.

After the completion of the charging, the battery was left in an atmosphere of 25 ° C. for 24 hours to return to room temperature, and the state of the safety valve was checked for these batteries.

As a result, for the battery A of the present invention, the valve 5
It was confirmed that the top surface of the battery was in a concave state, and the inside of the battery was normally depressurized. Further, no adhesion between the valve body 5 and the valve holding plate 6 occurred.

On the other hand, in the conventional battery B, the top surface of the valve body X and the valve holding plate Z adhered, and the state of the top surface could not be confirmed.

Next, the opening / closing valve pressure of these batteries was measured. Table 1 shows the results.

[0036]

[Table 1]

From the results shown in Table 1, with respect to the battery B of the conventional example, the opening / closing valve pressure was significantly reduced before and after charging at 60 ° C. In particular, the minimum value of the opening / closing valve pressure was very low, and the valve function deteriorated. It was confirmed that it was remarkable. On the other hand, in the battery A of the present invention, the remarkable decrease phenomenon as observed in the battery B of the conventional example did not occur, and the on-off valve pressure value was stable.

Example 2 of Confirming the Effect In the battery according to the second embodiment of the present invention, how the opening / closing valve pressure of the battery provided with the projection 11 on the valve holding plate 6 and the battery provided without the projection 11 changes. I checked. Specifically, when the variation of the on-off valve pressure was measured between the case where the protrusion 11 was provided and the case where the protrusion was not provided as in the second embodiment, the results shown in Table 2 were obtained.

[0039]

[Table 2]

From the results shown in Table 2, it was confirmed that a relatively high on-off valve pressure can be stably obtained by providing the projections 11.

[0041]

According to the structure of the present invention, it is possible to solve the problem of the adhesion between the valve element and the valve holding plate, which has occurred in the safety valve portion of the conventional sealed lead-acid battery, and the reduction of the on-off valve pressure due to this. , Which can provide an inexpensive sealed lead-acid battery that can reduce the overflow during battery formation and improve the visibility of the top surface of the valve body to improve the accuracy of the airtight inspection without impairing the productivity Therefore, the present invention is extremely useful industrially.

[Brief description of the drawings]

FIG. 1A is a top view showing a main part of a sealed lead-acid battery according to a first embodiment of the present invention. FIG. 1B is a sectional view of the main part.

FIG. 2 is a top view of a main part showing another valve holding plate having a direction different from that of the through hole of FIG. 1;

FIG. 3A is a top view showing a main part of a sealed lead-acid battery according to a second embodiment of the present invention. FIG. 3B is a cross-sectional view of the main part.

FIG. 4 is a top view showing a main part of a conventional sealed lead-acid battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery case 1a Cell chamber 2 Battery case room 3 Valve cylinder part 4 Concave part 5 Valve body 5a Top surface 5b Outer edge 6,6 'Valve holding plate 6a Wire part 6b Stress concentration part 7 Hole 8 Fitting protrusion 9,9' Through hole 10 Top cover 11 Projection

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsuneori Yoshimura 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. BB01 CC04 CC08

Claims (3)

[Claims] 1. A valve body is mounted on a valve cylinder formed on a battery case cover for covering an opening of a battery case for accommodating an electrode plate group, and the valve holding plate is fitted to a top surface of the valve body. In a sealed lead-acid battery mounted or joined to a battery case lid, a through-hole having a length dimension equal to or larger than the outer dimension of the valve body and a width dimension less than the outer dimension is formed in correspondence with a top surface of the valve body. A sealed lead-acid battery provided on a valve holding plate. 2. An upper lid joined to the battery case cover so as to cover the valve retainer plate, wherein the upper cover intersects a surface of the upper lid facing the valve retainer plate in a longitudinal direction of the through-hole, and the valve covers the valve. 2. The sealed lead-acid battery according to claim 1, further comprising a projection for limiting upward deformation of the holding plate. 3. The sealed lead-acid battery according to claim 1, wherein the valve holding plate is opaque and has a color that cannot see through the valve body.