JP2021009823A - Control valve type lead storage battery - Google Patents

Abstract

To disclose a technology capable of dramatically improving self discharge performance of a control valve type lead storage battery.SOLUTION: A control valve type lead storage battery comprises: a frame in which a housing space is formed; an electrode plate group that is housed in the housing space and comprises a positive electrode plate, a negative electrode plate, and a separator; and a control valve. The control valve comprises: a cylindrical valve seat on which a communication hole communicating with the housing space is formed, the valve seat formed so as to protrude toward the outside of the housing space; and a valve body including a peripheral wall part surrounding the valve seat's outer periphery and a closing part that faces the valve seat's opening and closes one end of the peripheral wall part. Under a predetermined condition, a pressure change rate of the housing space is equal to or lower than 119%.SELECTED DRAWING: Figure 9

Description

The techniques disclosed herein relate to controlled valve lead-acid batteries.

A lead-acid battery generally includes a housing in which a storage space is formed, a group of electrodes housed in the storage space and having a positive electrode plate, a negative electrode plate, and a separator, and an electrolytic solution (for example, an electrolytic solution) housed in the storage space. Dilute sulfuric acid) and. In such a lead-acid battery, for example, at the end of charging, water contained in the electrolytic solution may be electrolyzed in the accommodation space of the housing to generate oxygen gas from the positive electrode plate and hydrogen gas from the negative electrode plate. is there.

Here, a liquid lead-acid battery is known as one of the lead-acid batteries. In a liquid lead-acid battery, since an exhaust hole that is always open is formed in the housing, oxygen gas and hydrogen gas (hereinafter collectively referred to as "gas") generated in the housing space of the housing are always stored in the housing. It can be discharged to the outside of the body. However, in a liquid lead-acid battery, since the water content in the electrolytic solution is reduced by discharging the gas, it is necessary to replenish the accommodation space of the housing with purified water during the process of using the battery. Further, in the liquid lead-acid battery, the electrolytic solution is sufficiently accommodated in the accommodation space of the housing so that the electrolytic solution can flow. Therefore, when the battery is laid on its side or turned upside down, the electrolytic solution stored in the housing space of the housing tends to leak to the outside through the exhaust hole.

On the other hand, as one of the other lead-acid batteries, a control valve type lead-acid battery (also referred to as a closed-type lead-acid battery) is known. Unlike the above-mentioned liquid-type lead-acid battery, the control valve type lead-acid battery has almost no electrolytic solution flowing in the housing space, and the pressure in the housing space is less than a predetermined value under normal conditions. The containment space of the body is sealed.

Specifically, in the control valve type lead-acid battery, the separator is made of, for example, glass fiber, and the separator is impregnated with an electrolytic solution. Therefore, there is almost no electrolytic solution flowing in the accommodation space of the housing. Further, in the control valve type lead-acid battery, a control valve is provided in the housing instead of the exhaust hole. The control valve is a tubular valve seat having a communication hole that communicates with the accommodation space. The valve seat is formed so as to project toward the outside of the accommodation space, and the peripheral wall portion surrounding the outer periphery of the valve seat. A valve body that faces the opening of the valve seat and has a closing portion that closes one end of the peripheral wall portion, and normally, the gas generated in the accommodation space of the housing is discharged to the housing. It is in a closed state so that it is not discharged to the outside of the housing, and the accommodation space of the housing is in a closed state. In the control valve type lead-acid battery having such a configuration, the oxygen gas generated from the positive electrode plate moves to the negative electrode plate, recombines with the hydrogen generated in the negative electrode plate, and water is regenerated from the accommodation space of the housing. The decrease in water content in the electrolytic solution due to the discharge of gas is suppressed.

However, even in a control valve type lead-acid battery, it is impossible to completely eliminate the emission of gas generated in the accommodation space of the housing. For example, hydrogen gas is generated during overcharging. Therefore, the pressure in the accommodation space of the housing may increase due to the generation of gas. The control valve is opened when the pressure in the accommodation space of the housing exceeds a predetermined value. As a result, the gas generated in the housing space is discharged to the outside, and the pressure in the housing space approaches the normal pressure. As a result, the occurrence of swelling of the housing due to the increase in pressure in the accommodation space of the housing is suppressed.

As described above, in the control valve type lead-acid battery, the airtightness of the housing is required under normal conditions (see, for example, Patent Document 1). Further, conventionally, it is known that when a control valve type lead-acid battery has a poor airtightness in which the airtightness of the housing is not ensured, the capacity of the battery decreases (see, for example, Patent Documents 2 and 3).

Japanese Unexamined Patent Publication No. 5-744333 Japanese Unexamined Patent Publication No. 5-144478 Japanese Unexamined Patent Publication No. 9-321153

As described above, in the control valve type lead-acid battery, the airtightness of the housing is required under normal conditions. However, it is difficult to completely seal the accommodation space of the housing in the closed state while ensuring the opening / closing function of the control valve composed of the valve seat and the valve body as described above. Conventionally, the degree of airtightness of the housing has not been sufficiently examined.

This specification discloses a technique capable of dramatically improving the self-discharge performance of a control valve type lead-acid battery.

The control valve type lead-acid battery disclosed in the present specification includes a housing in which a storage space is formed, a group of electrode plates housed in the storage space and having a positive electrode plate, a negative electrode plate, and a separator, a control valve, and a control valve. The control valve is a tubular valve seat formed with a communication hole communicating with the accommodation space, and is a valve seat formed so as to project outward of the accommodation space and the valve. The valve body includes a peripheral wall portion that surrounds the outer periphery of the seat, and a closed portion that faces the opening of the valve seat and closes one end of the peripheral wall portion. The pressure change rate of the accommodation space under the predetermined conditions is 119% or less.

It is a front view which shows the appearance structure of the lead storage battery 100 in this embodiment. It is a rear view which shows the appearance structure of the lead storage battery 100. It is a top view which shows the appearance structure of the lead storage battery 100. It is a top view which shows the internal structure of the lead storage battery 100. It is explanatory drawing which shows the YZ cross-sectional structure of the lead storage battery 100 at the position of VV of FIG. It is explanatory drawing which shows the YZ cross-sectional structure of the lead-acid battery 100 at the position of VI-VI of FIG. It is a top view which shows the appearance structure of the lead-acid battery 100 in the state which the holding plate 18 is removed. It is a perspective view which shows a part of FIG. 7 enlarged. It is explanatory drawing which shows the XZ cross-sectional structure around the control valve 60 at the position of IX-IX of FIG. It is explanatory drawing which shows the performance evaluation result.

The technique disclosed in the present specification can be realized in the following forms.

(1) The control valve type lead-acid battery disclosed in the present specification is controlled by a housing in which a storage space is formed, a group of electrode plates housed in the storage space and having a positive electrode plate, a negative electrode plate, and a separator. A valve seat including a valve, wherein the control valve is a tubular valve seat formed with a communication hole communicating with the accommodation space, and is formed so as to project outward of the accommodation space. The pressure change rate of the accommodation space facing the peripheral wall portion surrounding the outer periphery of the valve seat and the opening of the valve seat under predetermined conditions is 119% or less.

The inventor of the present application has made extensive studies to dramatically improve the self-discharge performance of the control valve type lead-acid battery if the pressure change rate of the housing space under predetermined conditions is equal to or less than a predetermined value (119%). I found a new thing to do. According to this control valve type lead acid battery, since the pressure change rate of the housing space under predetermined conditions is 119% or less, the self-discharge of the control valve type lead acid battery is compared with the configuration in which the pressure change rate is higher than 119%. The discharge performance can be dramatically improved.

(2) In the control valve type lead-acid battery, the housing includes an electric tank having an opening and a lid for closing the opening of the electric tank, and is provided on an outer peripheral surface of a side wall of the lid in a predetermined direction. A rib extending to the surface may be formed. According to this control valve type lead-acid battery, ribs extending in a predetermined direction are formed on the outer peripheral surface of the side wall of the lid, so that the lid and the electric tank are airtight due to the deformation of the lid due to the temperature change. It is possible to suppress the deterioration of sex.

(3) In the control valve type lead-acid battery, a wall for dividing the accommodation space into a plurality of rooms is formed in the housing, and the electrode plate group is accommodated in each of the plurality of rooms. Further, each of the plurality of rooms is provided with a current collector which is electrically connected to any one of the plurality of positive electrode plates and the plurality of negative electrode plates, and the minimum thickness of the current collector is set. It may be configured to be 5.5 mm or more. According to this control valve type lead-acid battery, the strength of the current collector is higher than that of the configuration in which the minimum thickness of the current collector is less than 5.5 mm. Therefore, for example, it is possible to suppress a decrease in the airtightness of the housing due to thermal deformation of the current collector.

(4) The control valve type lead-acid battery may be further configured such that the pressure change rate of the accommodation space under the predetermined conditions is 117% or less. The inventor of the present application has conducted diligent studies, and further, if the pressure change rate of the housing space under predetermined conditions is equal to or less than a predetermined value (117%), the electrolytic solution contained in the housing space is contained. It was newly found that the liquid-reducing property that suppresses the decrease in water content of the water is dramatically improved. According to this control valve type lead acid battery, since the pressure change rate of the housing space under predetermined conditions is 117% or less, the control valve type lead acid battery is reduced as compared with the configuration in which the pressure change rate is higher than 117%. The liquid characteristics can be dramatically improved.

(5) The control valve type lead-acid battery may be further configured such that the pressure change rate of the accommodation space under the predetermined conditions is 109% or less. The inventor of the present application has found that the battery life performance can be dramatically improved if the pressure change rate of the housing space under predetermined conditions is equal to or less than a predetermined value (109%) through repeated diligent studies. I found a new one. The life performance of a battery referred to here is evaluated by the number of charge / discharge cycles (number of cycles) until the capacity of the battery drops to a specified capacity after repeated charging / discharging under certain conditions. According to this control valve type lead acid battery, since the pressure change rate of the housing space under predetermined conditions is 109% or less, the life of the control valve type lead acid battery is higher than that of the configuration in which the pressure change rate is higher than 109%. Performance can be dramatically improved.

(6) The control valve type lead-acid battery may be further configured such that the pressure change rate of the accommodation space under the predetermined conditions is 101% or less. According to this control valve type lead-acid battery, the pressure change rate of the housing space under predetermined conditions is 101% or less, so that all of self-discharge performance, liquid reduction characteristics and life performance can be dramatically improved. Can be done.

(7) In the control valve type lead-acid battery, oil may be present between the inner peripheral surface of the valve body of the control valve and the outer peripheral surface of the valve seat. According to this control valve type lead-acid battery, oil is present between the inner peripheral surface of the valve body and the outer peripheral surface of the valve seat in the control valve. Therefore, since the gap between the valve body and the valve seat is closed by the oil, the airtightness of the accommodation space of the housing can be improved.

(8) In the control valve type lead-acid battery, a protrusion is formed on the inner surface of the closing portion of the control valve, and the protrusion is viewed from the axial direction of the communication hole of the valve seat. It may be configured to be located inside the contour line of the opening of the valve seat. According to this control valve type lead acid battery, the protrusion formed on the inner surface of the control valve is located inside the opening of the valve seat. As a result, while suppressing the formation of a gap between the inner surface of the closed portion of the valve body and the open end of the valve seat due to the presence of the protruding portion, the moisture adhering to the inner surface of the closed portion of the valve body is removed from the protruding portion. It can be collected and dropped in the storage space for efficient collection.

A. Embodiment:
A-1. Basic configuration of lead-acid battery 100:
FIG. 1 is a front view showing the external configuration of the lead-acid battery 100 in the present embodiment, FIG. 2 is a rear view showing the external configuration of the lead-acid battery 100, and FIG. 3 shows the external configuration of the lead-acid battery 100. It is a top view. Each figure shows XYZ axes that are orthogonal to each other to identify the direction. In the present specification, for convenience, the Z-axis positive direction is referred to as "upward" and the Z-axis negative direction is referred to as "downward". However, the lead-acid battery 100 may actually be installed in a direction different from the direction shown in FIG. 1 and the like. The same applies to the figures after FIG. 4 described later.

The lead-acid battery 100 of the present embodiment is a control valve type lead-acid battery. The control valve type lead-acid battery has a high degree of freedom in the installation posture because it does not have an electrolytic solution flowing inside, and maintenance is easy because it does not require checking the amount of liquid or refilling water. The control valve type lead-acid battery is used, for example, as a power source for an uninterruptible power supply, a communication base station, a two-wheeled vehicle, or the like.

The lead-acid battery 100 includes a housing 10, a plurality of electrode plate groups 20 (see FIG. 7 and the like described later), a positive electrode side terminal member 30, a negative electrode side terminal member 40, and a control valve 60 (see FIG. 7 and the like described later). ) And. Hereinafter, the positive electrode side terminal member 30 and the negative electrode side terminal member 40 are also collectively referred to as “terminal members 30, 40”.

(Structure of housing 10)
As shown in FIGS. 1 to 3, the housing 10 has an electric tank 12 and a lid 14. The battery case 12 is a substantially rectangular parallelepiped container having an opening 12a (see FIG. 4 described later) on the upper surface, and is formed of, for example, a synthetic resin. The lid 14 is a member arranged so as to close the opening 12a of the electric tank 12, and is formed of, for example, a synthetic resin. By joining the peripheral edge portion of the lower surface of the lid 14 and the peripheral edge portion of the opening 12a of the electric tank 12 by, for example, heat welding, a storage space 15 maintained in airtightness with the outside is formed in the housing 10. There is. In the present embodiment, as shown in FIG. 3, the shape of the housing 10 seen from the vertical direction (Z-axis direction) is substantially rectangular, and the length of the pair of sides parallel to the X-axis direction is Y. Longer than the length of a pair of sides parallel to the axis.

The accommodation space 15 in the housing 10 is a plurality of (six in the present embodiment) rooms 16 arranged in a predetermined direction (X-axis direction in the present embodiment) by a plurality of (five in the present embodiment) walls 11. It is divided into. In the following, the direction in which a plurality of rooms 16 are arranged (X-axis direction) is referred to as "arrangement direction of rooms 16". In the present embodiment, the arrangement direction of the rooms 16 coincides with the direction parallel to the long sides (a pair of sides parallel to the X-axis direction) in the shape seen from the vertical direction of the housing 10.

Further, in the present embodiment, each wall 11 is composed of an upper wall 17 formed on the lid 14 and a lower wall 58 formed on the electric tank 12. Specifically, on the lower surface of the lid 14, a plurality of (five in this embodiment) upper walls 17 arranged in the arrangement direction of the room 16 are formed. A plurality of lower walls 58 (five in the present embodiment) arranged in the arrangement direction of the room 16 are formed in the electric tank 12. By joining the lower end of each upper wall 17 and the upper end of each lower wall 58 by, for example, heat welding, the airtightness between the adjacent rooms 16 is maintained.

FIG. 4 is a top view showing the internal configuration of the lead storage battery 100. FIG. 4 shows a state in which the lead storage battery 100 (electric tank 12) with the lid 14 removed is viewed from above. For convenience of illustration, FIG. 4 shows only a part (three) of a plurality of electrode plate groups 20 (and straps 52 and 54 connected to the plate group 20) described later. FIG. 5 is an explanatory view showing the YZ cross-sectional configuration of the lead-acid battery 100 at the position of VV in FIG. 3, and FIG. 6 is an explanatory view showing the YZ cross-sectional configuration of the lead-acid battery 100 at the position of VI-VI of FIG. It is a figure. In addition, in FIG. 5 and FIG. 6, a part of the configuration of the electrode plate group 20 is omitted so that the configuration of the electrode plate group 20 is shown in an easy-to-understand manner.

As shown in FIG. 4, one electrode plate group 20 is housed in each room 16 in the housing 10. In the present embodiment, since the space inside the housing 10 is divided into six rooms 16, the lead-acid battery 100 includes six electrode plate groups 20.

(Structure of electrode plate group 20)
As shown in FIGS. 4 to 6, the electrode plate group 20 includes a plurality of positive electrode plates 210, a plurality of negative electrode plates 220, and a separator 230. The plurality of positive electrode plates 210 and the plurality of negative electrode plates 220 are arranged so that the positive electrode plates 210 and the negative electrode plates 220 are alternately arranged in the arrangement direction (X-axis direction) of the room 16. Further, the separator 230 is arranged between the positive electrode plate 210 and the negative electrode plate 220 adjacent to each other, and is sandwiched between the positive electrode plate 210 and the negative electrode plate 220. Hereinafter, the positive electrode plate 210 and the negative electrode plate 220 are also collectively referred to as “electrode plates 210, 220”.

The positive electrode plate 210 has a positive electrode current collector 212 and a positive electrode active material 216 supported by the positive electrode current collector 212. The positive electrode current collector 212 is a conductive member having bones arranged in a substantially lattice pattern or a mesh pattern, and is formed of, for example, lead or a lead alloy. Further, the positive electrode current collector 212 has a positive electrode ear portion 214 protruding upward near the upper end thereof. The positive electrode active material 216 contains lead dioxide. The positive electrode active material 216 may further contain other known additives.

The negative electrode plate 220 has a negative electrode current collector 222 and a negative electrode active material 226 supported by the negative electrode current collector 222. The negative electrode current collector 222 is a conductive member having bones arranged in a substantially lattice pattern or a mesh pattern, and is formed of, for example, lead or a lead alloy. Further, the negative electrode current collector 222 has a negative electrode ear portion 224 protruding upward near the upper end thereof. The negative electrode active material 226 contains lead (sponge-like lead). The negative electrode active material 226 may further contain other known additives.

The separator 230 is a mat-like member made of glass fiber, which is an insulating material, and elastically deformable in the thickness direction (X-axis direction). The separator 230 is impregnated with an electrolytic solution (for example, dilute sulfuric acid). As described above, the separator 230 has a function of preventing a short circuit between the bipolar plates 210 and 220 and holding an electrolytic solution.

As shown in FIGS. 3 to 5, the positive electrode ear portions 214 of the plurality of positive electrode plates 210 constituting the electrode plate group 20 are connected to the positive electrode side strap 52. That is, the plurality of positive electrode plates 210 are electrically connected in parallel via the positive electrode side strap 52. Similarly, the negative electrode ear portions 224 of the plurality of negative electrode plates 220 constituting the electrode plate group 20 are connected to the negative electrode side strap 54. That is, the plurality of negative electrode plates 220 are electrically connected in parallel via the negative electrode side strap 54. The positive electrode side strap 52 and the negative electrode side strap 54 are formed of, for example, lead or a lead alloy. Hereinafter, the positive electrode side strap 52 and the negative electrode side strap 54 are also collectively referred to as “straps 52, 54”. The straps 52 and 54 correspond to current collectors within the scope of the claims.

As shown in FIGS. 4 to 6, a through hole 59 is formed in each lower wall 58 of the electric tank 12, and a connecting member 56 is arranged in the through hole 59. The connecting member 56 is made of, for example, lead or a lead alloy. In the lead-acid battery 100, the negative electrode side strap 54 housed in one room 16 is connected to another room 16 adjacent to one side (for example, the X-axis positive direction side) of the one room 16 via a connecting member 56. It is connected to the housed positive electrode side strap 52. Further, the positive electrode side strap 52 housed in the one room 16 is housed in another room 16 adjacent to the other side (for example, the X-axis negative direction side) of the one room 16 via the connecting member 56. It is connected to the negative electrode side strap 54. That is, the plurality of electrode plate groups 20 included in the lead storage battery 100 are electrically connected in series via the straps 52 and 54 and the connecting member 56. As shown in FIG. 5, the positive electrode side strap 52 housed in the room 16 located at one end of the room 16 in the arrangement direction (the X-axis positive direction side) is not the connecting member 56 but the positive electrode described later. It is connected to the pillar 34. Further, as shown in FIG. 6, the negative electrode side strap 54 housed in the room 16 located at the other end (X-axis negative direction side) of the room 16 in the arrangement direction is not the connecting member 56 but the negative electrode described later. It is connected to the pillar 44.

(Structure of terminal members 30 and 40)
As shown in FIGS. 1 and 3, the positive electrode side terminal member 30 is arranged near the end of the housing 10 on one side (X-axis positive direction side) of the chamber 16 in the arrangement direction, and is arranged on the negative electrode side terminal member. The 40 is arranged near the end of the housing 10 on the other side (X-axis negative direction side) of the room 16 in the arrangement direction.

As shown in FIG. 5, the positive electrode side terminal member 30 includes a positive electrode column 34 and a positive electrode side terminal portion 36. The positive electrode column 34 is a substantially cylindrical conductive member, and is formed of, for example, a lead alloy. The positive electrode column 34 is inserted into a hole formed in the lid 14, and is joined to the lid 14 by welding, for example. The lower end of the positive electrode column 34 projects downward from the lower surface of the lid 14, and is housed in the room 16 located at one end (the X-axis positive direction side) of the room 16 in the arrangement direction as described above. It is connected to the positive electrode side strap 52. The positive electrode side terminal portion 36 is, for example, a substantially L-shaped conductive member, and is formed of, for example, a lead alloy. The upper end portion of the positive electrode side terminal portion 36 projects upward from the upper surface of the lid 14, and the lower end portion of the positive electrode side terminal portion 36 is electrically connected to the upper end portion of the positive electrode column 34. The positive electrode side terminal portion 36 and the positive electrode column 34 may be an integral member.

As shown in FIG. 6, the negative electrode side terminal member 40 includes a negative electrode column 44 and a negative electrode side terminal portion 46. The negative electrode column 44 is a substantially cylindrical conductive member, and is formed of, for example, a lead alloy. The negative electrode column 44 is inserted into a hole formed in the lid 14, and is joined to the lid 14 by welding, for example. The lower end of the negative electrode column 44 projects downward from the lower surface of the lid 14, and is housed in the room 16 located at the other end (X-axis negative direction side) of the room 16 in the arrangement direction as described above. It is connected to the negative electrode side strap 54. The negative electrode side terminal portion 46 is, for example, a substantially L-shaped conductive member, and is formed of, for example, a lead alloy. The upper end portion of the negative electrode side terminal portion 46 projects upward from the upper surface of the lid 14, and the lower end portion of the negative electrode side terminal portion 46 is electrically connected to the upper end portion of the negative electrode column 44. The negative electrode side terminal portion 46 and the negative electrode column 44 may be an integral member.

(Structure of control valve 60)
As shown in FIG. 3, a holding plate 18 is arranged on the upper surface of the lid 14. The pressing plate 18 is a flat plate-shaped member extending in the arrangement direction (X-axis direction) of the chamber 16, and is formed of, for example, a synthetic resin. 7 is a top view showing the external configuration of the lead-acid battery 100 with the holding plate 18 removed, FIG. 8 is an enlarged perspective view of a part of FIG. 7, and FIG. 9 is a view. It is explanatory drawing which shows the XZ cross-sectional structure around the control valve 60 at the position of IX-IX of 7.

As shown in FIGS. 7 and 8, a recess 19 extending in the arrangement direction (X-axis direction) of the room 16 is formed on the upper surface of the lid 14. A plurality of control valves 60 (five in this embodiment) are arranged on the bottom surface of the recess 19. As shown in FIG. 9, each control valve 60 includes a valve seat 62 and a valve body 64. Each valve seat 62 is arranged on the upper side of each room 16, and is formed so as to project upward from the bottom surface of the recess 19 in a tubular shape. Each valve seat 62 is formed with a communication hole 66 that communicates with each room 16. In this embodiment, the valve seat 62 is integrally formed with the lid 14. Each valve body 64 is a rubber cap. Specifically, the valve body 64 has a tubular peripheral wall portion 68 that surrounds the outer periphery of the valve seat 62, and a closing portion 70 that closes one end of the peripheral wall portion 68. That is, the valve body 64 is attached to the valve seat 62 so as to close the opening on the upper side of the valve seat 62. In the normal state, the control valve 60 is in a closed state in which each valve body 64 is attached to the valve seat 62, so that each room 16 is sealed. On the other hand, when gas is generated in the room 16 due to overcharging or the like and the internal pressure rises above a predetermined value, the control valve 60 is in an open state with a gap between the valve body 64 and the valve seat 62. Can be discharged to the outside. The holding plate 18 is arranged so as to cover the plurality of control valves 60 from above. As a result, each valve body 64 is suppressed from coming out upward from each valve seat 62.

A-2. Operation of lead-acid battery 100:
When the lead-acid battery 100 is discharged, a load (not shown) is connected to the positive electrode side terminal portion 36 of the positive electrode side terminal member 30 and the negative electrode side terminal portion 46 of the negative electrode side terminal member 40, and each electrode group 20 The electric power generated by the reaction on the positive electrode plate 210 (reaction in which lead sulfate is generated from lead dioxide) and the reaction on the negative electrode plate 220 (reaction in which lead sulfate is generated from lead (spine-like lead)) is supplied to the load. When charging the lead-acid battery 100, a power supply (not shown) is connected to the positive electrode side terminal portion 36 of the positive electrode side terminal member 30 and the negative electrode side terminal portion 46 of the negative electrode side terminal member 40, and is supplied from the power supply. The generated electric power causes a reaction on the positive electrode plate 210 of each electrode group 20 (a reaction in which lead dioxide is produced from lead sulfate) and a reaction on the negative electrode plate 220 (a reaction in which lead (lead (spear-like lead) is produced from lead sulfate)). The lead storage battery 100 is charged.

A-3. Detailed configuration of lead-acid battery 100:
(Structure related to airtightness of room 16)
The lead-acid battery 100 (housing 10) of the present embodiment satisfies the following first requirement in terms of airtightness in any of the plurality of rooms 16.
<First requirement>
The pressure change rate of the room 16 under the predetermined conditions of the housing 10 is 119% or less.

Here, the "predetermined conditions" are a first state in which the pressure in the room 16 of the lead-acid battery 100 is lower than the pressure outside the housing 10, and a predetermined first time from the first state. It means to make it the second state when it is left alone. The ambient temperature of the lead-acid battery 100 is preferably 10 ° C. or higher and 35 ° C. or lower, and more preferably room temperature (25 ° C.). The “rate of change in pressure of the room 16 under predetermined conditions” is the ratio (%) of the pressure of the room 16 in the second state to the pressure of the room 16 in the first state. The first time is, for example, one hour. In addition, it is preferable that the first state is a state in which a predetermined second time (shorter than the first time) has elapsed immediately after the pressure in the room 16 is made negative. This is because the pressure in the room 16 is unstable immediately after the pressure in the room 16 is made negative, and the pressure in the room 16 in the first state may not be accurately measured.
For example, if the pressure of the room 16 in the first state is 80 kPa and the pressure of the room 16 in the second state is 95 kPa, the pressure change rate of the room 16 under the predetermined conditions is 118.75%. It will meet the first requirement.

Further, it is preferable that the lead storage battery 100 further satisfies the following second requirement in terms of airtightness in any of the plurality of rooms 16.
<Second requirement>
The pressure change rate of the room 16 under the predetermined conditions of the housing 10 is 117% or less.

Further, it is preferable that the lead storage battery 100 further satisfies the following third requirement in terms of airtightness in any of the plurality of rooms 16.
<Third requirement>
The pressure change rate of the room 16 under the predetermined conditions of the housing 10 is 109% or less.

Further, it is preferable that the lead storage battery 100 further satisfies the following fourth requirement in terms of airtightness in any of the plurality of rooms 16.
<Fourth requirement>
The pressure change rate of the room 16 under the predetermined conditions of the housing 10 is 101% or less.

(Structure related to lid 14)
As shown in FIGS. 1 to 3 and 7, ribs 80 extending in a predetermined direction are formed on the outer peripheral surface of the side wall of the lid 14. The rib 80 is formed so as to protrude from the outer peripheral surface of the side wall of the lid 14, and is a portion of the side wall of the lid 14 that is thicker than the peripheral portion adjacent to the rib 80. Specifically, as shown in FIG. 2, a plurality of ribs 80 are formed on both ends of the back surface of the outer peripheral surface of the lid 14 parallel to the arrangement direction of the room 16. Each rib 80 extends in the vertical direction (Z-axis direction). The rib 80 may have a shape extending in the horizontal direction (X-axis direction), for example. Further, in the present embodiment, as shown in FIGS. 3 and 7, a plurality of ribs 80 are formed on each of the outer peripheral surfaces of the lid 14 that are orthogonal to the arrangement direction of the room 16.

The lid 14 may be deformed due to, for example, a temperature change. When the lid 14 is deformed, for example, a gap may be formed between the lid 14 and the electric tank 12, and the airtightness of the room 16 may be lowered. On the other hand, in the present embodiment, since the rib 80 is formed on the lid 14, the airtightness between the lid 14 and the electric tank 12 is lowered due to the deformation of the lid 14 due to the temperature change. Can be suppressed. Further, if the lid 14 is provided with the rib 80, it is possible to prevent the lid 14 from being twisted or the like during molding of the lid 14.

(Structure related to straps 52 and 54)
In the present embodiment, the minimum thickness of each strap 52, 54 is 5.5 mm or more. In the present embodiment, the thickness D (see FIG. 5) of each of the straps 52 and 54 in the vertical direction (Z-axis direction) is 5.5 mm or more. According to the present embodiment, the strength of the straps 52 and 54 is higher than that of the configuration in which the minimum thickness of the straps 52 and 54 is less than 5.5 mm. Therefore, it is possible to suppress a decrease in the airtightness of the housing 10 due to, for example, thermal deformation of the straps 52 and 54.

(Configuration related to control valve 60)
As shown in FIG. 9, in the present embodiment, the oil 90 exists between the inner peripheral surface of the valve body 64 of the control valve 60 and the outer peripheral surface of the valve seat 62. In the present embodiment, the oil 90 is present between the inner peripheral surface of the valve body 64 and the outer peripheral surface of the valve seat 62 over the entire circumference of the control valve 60. It is preferable that the oil 90 is also present between the upper end of the valve seat 62 and the inner surface of the closing portion 70 of the valve body 64. According to the present embodiment, since the gap between the valve body 64 and the valve seat 62 is closed by the oil 90, the airtightness of the room 16 of the housing 10 can be improved.

Further, as shown in FIG. 9, in the present embodiment, a protrusion 72 is formed on the inner surface of the closing portion 70 of the valve body 64. The protrusion 72 is a portion that undulates from the inner surface of the closing portion 70 in order to indicate a pictogram such as a model number of the valve body 64. When viewed from the vertical direction, all the protrusions 72 are located inside the contour line of the opening L at the upper end of the valve seat 62. According to the present embodiment, the closed portion of the valve body 64 is suppressed while suppressing the formation of a gap between the inner surface of the closed portion 70 of the valve body 64 and the open end of the valve seat 62 due to the presence of the protruding portion 72. Moisture adhering to the inner surface of the 70 can be collected in the protrusion 72 and dropped to be efficiently collected in the room 16.

A-4. Performance evaluation:
A plurality of samples (S1 to S12) of lead-acid batteries were prepared, and performance evaluation was performed on these samples. FIG. 10 is an explanatory diagram showing the performance evaluation result.

(For each sample)
As shown in FIG. 10, each sample has a different rate of change in pressure (% or less, also simply referred to as “rate of change in pressure”) of the room 16 under the above-mentioned predetermined conditions. The airtightness of the accommodation space 15 (room 16) of the housing 10 is mainly determined by the airtightness of the valve seat 62 and the valve body 64 in the control valve 60. Therefore, for example, by changing the size of the gap between the valve seat 62 and the valve body 64 or changing the elastic force of the rubber material forming the valve body 64, a plurality of lead-acid batteries having different pressure change rates. 100 can be made.

The pressure change rate of each sample was specified as follows. That is, a hole is made in the housing 10 of each sample and suction is performed using a vacuum pump to bring the accommodation space 15 (room 16) of the housing 10 into a negative pressure state, and the hole is closed with the pressure gauge inserted. After that, the pressure when the measured value of the pressure gauge becomes stable is defined as the pressure of the room 16 in the first state. Next, the pressure when left for the first time from the first state is defined as the pressure of the room 16 in the second state. Then, the pressure change rate was specified from the pressure of the room 16 in the first state and the pressure of the room 16 in the second state.

(Evaluation items and evaluation methods)
Using each sample of the lead-acid battery, three items of self-discharge performance, liquid reduction characteristic, and life characteristic (light load life characteristic) were evaluated.

The self-discharge performance was evaluated as follows. That is, each sample of the lead-acid battery was left for 4 weeks in an atmosphere of 40 ° C. after being fully charged, and the difference in 10-hour rate capacity before and after leaving was measured by the methods shown in a) to d) below. The difference in 10-hour rate capacity in sample S10 was taken as 100, and the difference in 10-hour rate capacity in each sample was expressed as a relative value. This relative value is the evaluation value of the self-discharge performance. As shown in FIG. 10, when the evaluation value of the self-discharge performance exceeds 120, it is evaluated as the best “⊚”, and when the evaluation value of the self-discharge performance is 100 or more and 120 or less, it is good “◯”. When the evaluation value of the self-discharge performance was less than 100, it was evaluated as defective “x”.
a) Fully charge the sample.
b) After the full charge is completed, the sample is allowed to stand under the condition of 25 ± 2 ° C., and the discharge of c) below is started.
c) The sample is discharged at a constant reference current I ₁₀ (A) until the discharge end voltage (1.75 × number of cells (V)) is reached. The reference current I ₁₀ (A) is a value obtained by the following formula.
I ₁₀ = _{C 10/10}
(However, C ₁₀ has a 10-hour rated capacity (Ah))
d) The discharge duration in c) above is measured to calculate the 10-hour rate capacity.

The liquid reduction characteristics were evaluated as follows. That is, each sample of the lead-acid battery was continuously charged at 0.5 A for 2 weeks in an atmosphere of 25 ° C. after being fully charged, and the difference in 10-hour rate capacity before and after continuous charging was measured by the method described above. .. The difference in 10-hour rate capacity in sample S8 was taken as 100, and the difference in 10-hour rate capacity in each sample was expressed as a relative value. This relative value is the evaluation value of the liquid reduction characteristic. As shown in FIG. 10, when the evaluation value of the liquid-reducing characteristic is 110 or more, it is evaluated as the best "◎", and when the evaluation value of the liquid-reducing characteristic is 100 or more and less than 110, it is good "○". When the evaluation value of the liquid reducing characteristic was less than 100, it was evaluated as defective "x".

The lifespan was evaluated as follows. That is, each sample of the lead-acid battery was subjected to a light load life test by the methods shown in a) to f) below, and the number of times of life was determined. The number of lifespans in each sample was expressed as a relative value, where the number of lifespans in sample S5 was 100. This relative value is the evaluation value of the life characteristic. As shown in FIG. 10, when the evaluation value of the life characteristic is 110 or more, it is evaluated as the best "◎", and when the evaluation value of the life characteristic is 100 or more and less than 110, it is evaluated as good "○". However, when the evaluation value of the life characteristic was less than 100, it was evaluated as defective "x".
a) Discharge is performed for 4 minutes using the above-mentioned reference current I ₁₀ (A) as the discharge current, and charging is subsequently performed for 10 minutes at a charging voltage of 14.8 V ± 0.1 V. The cycle of this discharge and charge is defined as one life.
b) As for the temperature during the test, the ambient temperature of the lead storage battery is 40 to 45 ° C.
c) During the test, leave it for 60 hours every 428 times.
d) After leaving c), continuous discharge is performed for 30 seconds at the reference current I ₁₀ (A), and the voltage at the 30th second is measured. After that, a) is charged.
e) The end of the test shall be when it is confirmed that the voltage at the 30th second measured in the test of d) becomes 7.2 V or less and does not rise again.
f) The number of service life shall be the number of times that the voltage at the 30th second when discharged at the reference current I ₁₀ (A) becomes 7.2 V. The number of times of life is obtained from the following relationship line between the number of times and the voltage at the 30th second.
N = 428 × n + (428- (3082 / Vn))
N: Lifespan (times)
n: Number of discharges at the reference current I ₁₀ (A) for determining the life
Vn: Nth 30th second voltage

(Evaluation results)
As shown in FIG. 10, the sample S10 satisfies the first requirement that the pressure change rate is 118.8% and the pressure change rate is 119% or less. On the other hand, in sample S11, the pressure change rate is 120.0%, which does not satisfy the first requirement. In the sample S11, the difference in the pressure change rate from the sample S10 is small, but the evaluation value of the self-discharge performance is "80", which is larger than that of the sample S10 in which the evaluation value of the self-discharge performance is "100". Below. Further, in sample S12, the pressure change rate is 125.0%, which does not satisfy the first requirement. In sample S12, the evaluation value of self-discharge performance is "40", which is much lower than that of sample S10. From these evaluation results, it can be seen that if the pressure change rate of the accommodation space 15 (room 16) of the housing 10 under predetermined conditions is 119% or less, the self-discharge performance of the lead-acid battery 100 is dramatically improved (FIG. See the graph of self-discharge performance in 10).

Further, in the samples S1 to S10, the pressure change rate is 119% or less, which satisfies the first requirement. Further, it can be seen that the pressure change rate decreases in the order of sample S10 to sample S1, and the lower the pressure change rate, the higher the evaluation value of the self-discharge performance. Further, from the evaluation results of the samples S7 and S8, it can be seen that when the pressure change rate is 113% or less, the evaluation value of the self-discharge performance becomes "110" or more, and the self-discharge performance is further improved. Further, from the evaluation results of the samples S3 and S4, it can be seen that when the pressure change rate is 102% or less, the evaluation value of the self-discharge performance becomes "122" or more, and the self-discharge performance is further improved.

Further, in the sample S8, the second requirement that the pressure change rate is 116.3% and the pressure change rate is 117% or less is satisfied. On the other hand, in sample S9, the pressure change rate is 117.5%, which does not satisfy the second requirement. In the sample S9, the difference in the pressure change rate from the sample S8 is small, but the evaluation value of the liquid reduction characteristic is "85", which is larger than that of the sample S8 in which the evaluation value of the liquid reduction characteristic is "100". Below. Further, in the samples S10 to S12, the pressure change rate is 118.8% to 125.0%, which does not satisfy the second requirement. In the samples S10 to S12, the evaluation values of the self-discharge performance are "75" to "60", which are much lower than those of the samples S8. From these evaluation results, it can be seen that if the pressure change rate of the accommodation space 15 (room 16) of the housing 10 under predetermined conditions is 117% or less, the liquid-reducing characteristics of the lead-acid battery 100 are dramatically improved (FIG. See the graph of liquid reduction characteristics of 10).

Further, in all of the samples S1 to S8, the pressure change rate is 117% or less, which satisfies the second requirement. Further, it can be seen that the pressure change rate decreases in the order of sample S8 to sample S1, and the lower the pressure change rate, the higher the evaluation value of the liquid reducing characteristic. Further, from the evaluation results of the samples S4 and S5, it can be seen that when the pressure change rate is 106% or less, the evaluation value of the liquid reducing characteristic becomes "110" or more, and the liquid reducing characteristic is further improved.

Further, the sample S5 satisfies the above-mentioned third requirement that the pressure change rate is 108.8% and the pressure change rate is 109% or less. On the other hand, in sample S6, the pressure change rate is 110.0%, which does not satisfy the third requirement. In the sample S6, the difference in the pressure change rate from the sample S5 is small, but the evaluation value of the life characteristic is "80", which is much lower than that of the sample S5 in which the evaluation value of the life characteristic is "100". Further, in the samples S7 to S12, the pressure change rate is 112.5% to 125.0%, which does not satisfy the third requirement. In the samples S7 to S12, the evaluation values of the life characteristics are "75" to "67", which are much lower than those of the samples S5. From these evaluation results, it can be seen that if the pressure change rate of the accommodation space 15 (room 16) of the housing 10 under predetermined conditions is 109% or less, the life characteristics of the lead-acid battery 100 are dramatically improved (FIG. 10). See the graph of life characteristics).

Further, in the samples S1 to S5, the pressure change rate is 109 or less, which satisfies the third requirement. Further, it can be seen that the pressure change rate decreases in the order of sample S5 to sample S1, and the lower the pressure change rate, the higher the evaluation value of the life characteristic. Further, from the evaluation results of the samples S3 and S4, it can be seen that when the pressure change rate is 102% or less, the evaluation value of the life characteristic becomes "110" or more, and the life characteristic is further improved.

Further, it can be seen that when the pressure change rate is 101% or less, all of the self-discharge performance, the liquid reduction characteristic, and the life performance are dramatically improved (see the three graphs in FIG. 10).

B. Modification example:
The technique disclosed in the present specification is not limited to the above-described embodiment, and can be transformed into various forms without departing from the gist thereof. For example, the following modifications are also possible.

The configuration of the lead-acid battery 100 in the above embodiment is merely an example and can be variously modified. For example, in the above embodiment, all of the plurality of rooms 16 formed in the housing 10 satisfy the first to fourth requirements, but at least the plurality of rooms 16 formed in the housing 10 are satisfied. For one, at least the first requirement may be met.

In the lead-acid battery 100 according to the above embodiment, the oil 90 was present between the inner peripheral surface of the valve body 64 of the control valve 60 and the outer peripheral surface of the valve seat 62, but the oil 90 was not present. May be good. The dimensions of the valve body 64 and the valve seat 62 may be adjusted so that the room 16 formed in the housing 10 satisfies the first requirement.

10: Housing 11: Wall 12: Electric tank 12a: Opening 14: Lid 15: Accommodation space 16: Room 17: Upper wall 18: Holding plate 19: Recess 20: Electrode plate group 30, 40: Terminal member 34: Positive electrode Pillar 36: Positive electrode side terminal 44: Negative electrode pillar 46: Negative electrode side terminal 52, 54: Strap 56: Connecting member 58: Lower wall 59: Through hole 60: Control valve 62: Valve seat 64: Valve body 66: Communication hole 68: Peripheral wall 70: Closure 72: Protrusion 80: Rib 90: Oil 100: Lead storage battery 210: Positive electrode plate 212: Positive electrode current collector 214: Positive electrode ear 216: Positive electrode active material 220: Negative electrode plate 222: Negative electrode collection Electric body 224: Negative electrode ear 226: Negative electrode active material 230: Separator L: Opening

Claims (8)

Control valve type lead acid battery
A housing with a storage space and
A group of electrode plates accommodated in the accommodation space and provided with a positive electrode plate, a negative electrode plate, and a separator.
Control valve and
With
The control valve
A tubular valve seat having a communication hole communicating with the accommodation space, and a valve seat formed so as to project outward from the accommodation space.
A valve body having a peripheral wall portion surrounding the outer periphery of the valve seat and a closed portion facing the opening of the valve seat and closing one end of the peripheral wall portion is provided.
The pressure change rate of the accommodation space under predetermined conditions is 119% or less.
Control valve type lead acid battery. The control valve type lead-acid battery according to claim 1.
The housing includes an electric tank having an opening and a lid for closing the opening of the electric tank.
Ribs extending in a predetermined direction are formed on the outer peripheral surface of the side wall of the lid.
Control valve type lead acid battery. The control valve type lead-acid battery according to claim 1 or 2.
A wall for dividing the accommodation space into a plurality of rooms is formed in the housing, and the electrode plate group is accommodated in each of the plurality of rooms.
Further, a current collector which is housed in each of the plurality of rooms and is electrically connected to any of the plurality of positive electrode plates and the plurality of negative electrode plates is provided.
The minimum thickness of the current collector is 5.5 mm or more.
Control valve type lead acid battery. The control valve type lead-acid battery according to any one of claims 1 to 3.
Further, the pressure change rate of the accommodation space under the predetermined conditions is 117% or less.
Control valve type lead acid battery. The control valve type lead-acid battery according to claim 4.
Further, the pressure change rate of the accommodation space under the predetermined conditions is 109% or less.
Control valve type lead acid battery. The control valve type lead-acid battery according to claim 5.
Further, the pressure change rate of the accommodation space under the predetermined conditions is 101% or less.
Control valve type lead acid battery. The control valve type lead-acid battery according to any one of claims 1 to 6.
Oil is present between the inner peripheral surface of the valve body and the outer peripheral surface of the valve seat in the control valve.
Control valve type lead acid battery. The control valve type lead-acid battery according to any one of claims 1 to 7.
A protrusion is formed on the inner surface of the closed portion of the control valve.
Seen from the axial direction of the communication hole of the valve seat, the protrusion is located inside the contour line of the opening of the valve seat.
Control valve type lead acid battery.

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