JP7021527B2 - Lead-acid battery - Google Patents

Description

The techniques disclosed herein relate to lead acid batteries.

The lead-acid battery is mounted on a vehicle such as an automobile, and is used as a power source for the vehicle or as a power supply source for electrical components mounted on the vehicle. Such a lead-acid battery has an opening, an electric tank in which a plurality of cell chambers arranged in a predetermined direction are formed inside, a lid joined to the opening of the electric tank, and an arrangement in each cell chamber. It is equipped with a group of electrode plates. Some of such lead-acid batteries are provided with a plurality of liquid taps for replenishing the electrolytic solution in each cell chamber. Each liquid port plug is formed with an exhaust hole that communicates with each cell chamber and discharges gas (oxygen gas or hydrogen gas) generated from the electrode plate in each cell chamber to the outside of the lead storage battery when the lead storage battery is charged. It is common to have.

In lead-acid batteries, a phenomenon in which the water content in the electrolytic solution decreases (hereinafter referred to as "reduced liquid") may occur. For example, the following can be considered as the cause of the occurrence of this liquid reduction. When a lead-acid battery is used in a high-temperature environment such as an engine room, water vapor generated by evaporation of a part of water in the electrolytic solution is released to the outside of the cell chamber through the exhaust hole of the liquid spout. Alternatively, the electrolytic solution becomes mist and is discharged to the outside of the cell chamber through the exhaust hole of the liquid port plug. As a result, liquid reduction occurs in each cell chamber. When the liquid is reduced, problems such as a decrease in battery capacity and corrosion of the current collector connected to the electrode plate group may occur.

Therefore, conventionally, a lead-acid battery in which a sheet is arranged on a lid so as to cover the exhaust holes of a plurality of liquid spouts is known in order to suppress liquid reduction (see, for example, Patent Document 1). In this conventional lead-acid battery, the surface of the seat facing the lid is not joined to the lid and extends from the exhaust hole of the liquid spout to the edge of the seat. Has a non-junction region. In this conventional lead-acid battery, a porous filter is arranged in the exhaust hole of the liquid port plug, and the gas generated in each cell chamber is discharged to the outside of the lead-acid battery through the porous filter.

Japanese Unexamined Patent Publication No. 2005-276471

However, in the above-mentioned conventional lead-acid battery in which the sheet is arranged on the lid, the liquid reduction may not be sufficiently suppressed. In particular, in recent years, further improvement of the liquid reduction suppressing performance has been required from the viewpoint of prolonging the life of the lead storage battery, and the above-mentioned conventional lead storage battery is sufficient for further improvement of the liquid reduction suppressing performance. Can't respond to. It should be noted that, for example, the liquid reduction suppressing performance can be improved by increasing the aeration resistance of the porous filter. However, if the ventilation resistance of the porous filter is made too large, there arises a problem that the discharge performance of the gas generated in the cell chamber is deteriorated.

This specification discloses a technique capable of improving the liquid reduction suppressing performance while suppressing the deterioration of the gas discharge performance generated in the accommodation chamber of the housing.

The lead-acid battery disclosed in the present specification includes a housing in which a storage chamber is formed and a through hole communicating with the storage chamber is formed, a positive electrode and a negative electrode arranged in the storage chamber, and the housing. The liquid spout, which is attached to the formed through hole and has a communication passage that communicates with the storage chamber, and the communication passage formed in the liquid mouth plug on the surface of the housing so as to face each other. The sheet is provided with an arranged sheet, and the facing surface of the sheet facing the housing is a joining region joined to the housing and not joined to the housing, and the liquid spout is not joined to the housing. It has a non-joint region extending from the communication passage to the edge of the sheet, and the ventilation resistance of the liquid spout from the outside of the housing to the accommodation chamber in the communication passage is in the communication passage. It is larger than the ventilation resistance from the accommodation chamber to the outside of the housing.

It is a perspective view which shows the appearance structure of the lead storage battery 100 in this embodiment. It is explanatory drawing which shows the XY plane structure of the lead storage battery 100. It is explanatory drawing which shows the YZ cross-sectional structure of the lead-acid battery 100 at the position of III-III of FIG. 1 and FIG. It is explanatory drawing which shows the YZ cross-sectional structure of the lead storage battery 100 at the position of IV-IV of FIG. 1 and FIG. It is explanatory drawing which enlarges and shows the YZ cross-sectional structure of the part of the liquid spout 160 and the sheet 300. It is explanatory drawing which shows the performance evaluation result. It is explanatory drawing which shows the relationship between the displacement of a valve body 650 in a liquid mouth plug 160, and a sheet 300.

The techniques disclosed herein can be realized in the following forms.

(1) The lead-acid battery disclosed in the present specification is a lead-acid battery, which is arranged in the accommodation chamber and a housing in which a storage chamber is formed and a through hole communicating with the accommodation chamber is formed. A positive and negative electrodes, a liquid spout that is attached to the through hole formed in the housing and has a communication passage that communicates with the storage chamber, and a liquid spout that is formed on the surface of the housing. A sheet arranged so as to face the communication passage is provided, and the facing surface of the sheet facing the housing is joined to the housing with a joining region joined to the housing. It also has a non-bonded region extending from the communication passage of the liquid spout to the edge of the sheet, and has a non-joining region extending from the outside of the housing in the communication passage of the liquid spout to the accommodation chamber. The ventilation resistance of the above is larger than the ventilation resistance from the accommodation chamber to the outside of the housing in the communication passage.

The purpose of forming a communication passage in the liquid port plug is, for example, to discharge the gas (oxygen gas or hydrogen gas) generated in the accommodation chamber when the lead storage battery is charged to the outside of the lead storage battery through the communication passage. However, when a continuous passage is formed in the liquid port plug, a phenomenon that the water content in the electrolytic solution in the accommodation chamber is reduced (hereinafter referred to as "reduced liquid") occurs. That is, in an environment where the water vapor in the electrolytic solution evaporates and water vapor is likely to be generated, for example, at a high temperature, the water vapor is discharged to the outside of the lead-acid battery through the communication passage of the liquid port plug, so that the water vapor is discharged to the outside of the lead storage battery. This is because the water content in the electrolytic solution is reduced. Therefore, as described above, conventionally, a lead-acid battery in which a sheet is arranged on the surface of a housing so as to cover an exhaust hole (communication passage) of a liquid spout is known in order to suppress liquid reduction. However, with this conventional lead-acid battery, liquid reduction cannot be sufficiently suppressed. Therefore, in this conventional lead-acid battery, for example, if the ventilation resistance of the exhaust hole of the liquid port plug is increased, water vapor is less likely to be discharged from the exhaust hole to the outside of the lead-acid battery, so that the liquid reduction suppressing performance of the lead-acid battery is improved. Can be made to. However, on the other hand, if the ventilation resistance of the exhaust hole of the liquid port plug is increased, it becomes difficult for the gas generated in the accommodation chamber to be discharged to the outside of the lead storage battery, so that the gas discharge performance of the lead storage battery deteriorates. Occurs.

Therefore, the inventor of the present application pays attention to the environment in which water vapor is likely to be generated in an environment in which liquid reduction is likely to occur. In an environment where water vapor is likely to be generated, for example, at 60 ° C or higher, priority is given to liquid reduction suppression performance over gas discharge performance so that water vapor is less likely to be discharged to the outside of the lead-acid battery. I thought about what I could do. Then, as a result of trial and error, the inventor of the present application came up with the idea of suppressing the discharge of water vapor by forming a high-humidity space in the path of water vapor from the communication passage of the liquid port plug to the outside of the lead storage battery. .. This is because if a high-humidity space is formed in the water vapor path, the water vapor generated in the accommodation chamber is further suppressed from being discharged by the high-humidity space. Then, the inventor of the present application examined forming a high humidity space between the seat and the housing for the following reasons. That is, in an environment where water vapor is unlikely to be generated, it is difficult to form a high humidity space between the seat and the housing. Therefore, it is not possible to suppress the discharge of water vapor, but there is no problem because it is difficult for the liquid to be reduced in the first place. On the other hand, since gas is easily discharged, deterioration of gas discharge performance can be suppressed. On the other hand, in an environment where water vapor is likely to be generated, a high humidity space is likely to be formed between the seat and the housing. Therefore, the water vapor is less likely to be discharged, and the liquid reduction can be suppressed.

However, in order to form and maintain a high-humidity space between the seat and the housing, it is necessary to prevent the water vapor in the high-humidity space from flowing back into the containment chamber through the communication passage of the liquid spout. Is preferable. However, if, for example, the ventilation resistance of the communication passage of the liquid spout is increased in order to suppress the backflow of water vapor, it becomes difficult for gas to be discharged in an environment where water vapor is hard to be generated, and the gas discharge performance is deteriorated. ..

Therefore, in this lead-acid battery, the ventilation resistance from the outside of the housing to the housing chamber in the communication passage of the liquid port plug is larger than the ventilation resistance from the storage chamber to the outside of the housing in the communication passage. The ventilation resistance from the accommodation chamber to the outside of the housing in the passage is relatively small. Therefore, for example, in an environment where water vapor is unlikely to be generated, the gas generated in the accommodation chamber can be smoothly discharged to the outside of the lead storage battery. On the other hand, in an environment where water vapor is likely to be generated, a high humidity space is formed between the housing and the seat by the water vapor released through the communication passage of the liquid spout, and thus in the housing chamber of the housing. Liquid reduction can be suppressed. In addition, the ventilation resistance from the outside of the housing to the accommodation chamber in the continuous passage is relatively large. Therefore, when a high humidity space is formed between the housing and the seat by water vapor, the humidity of the space is less likely to decrease, and it is possible to maintain a state in which liquid reduction in the housing chamber of the housing is suppressed. can. That is, according to the present lead-acid battery, it is possible to improve the liquid reduction suppressing performance while suppressing the deterioration of the gas discharge performance generated in the accommodation chamber of the housing.

(2) In the lead-acid battery, the ventilation resistance from the accommodation chamber to the outside of the housing in the communication passage of the liquid spout may be 5.5 kPa or less. In this lead-acid battery, the ventilation resistance from the accommodation chamber to the outside of the housing in the continuous passage of the liquid spout is 5.5 kPa or less. As a result, it is possible to suppress deformation of the housing due to an increase in the internal pressure of the accommodation chamber, as compared with the case where the ventilation resistance is larger than 5.5 kPa. That is, according to this lead-acid battery, it is possible to improve the liquid reduction suppressing performance and suppress the deformation of the housing while suppressing the deterioration of the gas discharge performance.

(3) In the lead storage battery, the communication passage of the liquid port plug opens to the inner space formed inside the liquid port plug and the outer surface side of the housing and communicates with the inner space. An opening and an inner opening that opens to the accommodation chamber side and communicates with the internal space, and the opening area is smaller than the area of the cross section of the internal space orthogonal to the axial direction of the liquid spout. In addition, it is displaceably arranged in the internal space at a first position where at least a part is in contact with the peripheral portion of the inner opening and a second position which is separated from the outer opening side. It may be configured to include a valve body. In this lead storage battery, the communication passages of the liquid spout are located in the internal space formed inside the liquid spout, the outer opening that opens to the outer surface side of the housing and communicates with the inner space, and the accommodation chamber side. It includes an inner opening that opens and communicates with the internal space, and whose opening area is smaller than the area of the cross section orthogonal to the axial direction of the liquid spout in the internal space. A valve body is arranged in the internal space, and at least a part of the valve body can be displaced to a first position in contact with the peripheral portion of the inner opening and a second position in contact with the outer opening side. Has been done. Since the valve body is present in the communication passage, the electrolytic solution in the accommodation chamber is unlikely to be discharged to the outside of the housing through the communication passage. Further, the size of the gap formed between the valve body and the inner opening when the valve body is in the first position is the size of the gap between the valve body and the inner opening when the valve body is in the second position. It is small compared to the size of the gap formed between. This means that the ventilation resistance of the communication passage when the valve body is in the first position is larger than the ventilation resistance of the communication passage when the valve body is in the second position. Therefore, when the internal pressure of the housing chamber of the housing rises due to the gas generated in the housing chamber, the valve body is displaced from the first position to the second position, so that the ventilation resistance of the communication passage becomes relatively small. Therefore, the gas generated in the accommodation chamber can be smoothly discharged to the outside of the lead storage battery. On the other hand, when a high humidity space is formed between the housing and the seat by water vapor, the valve body is displaced from the second position to the first position even if the internal pressure of the accommodation chamber is lowered, for example. As a result, the ventilation resistance of the communication passage becomes relatively large, so that the humidity of the space between the housing and the seat is less likely to decrease, and it is possible to maintain a state in which liquid reduction in the housing chamber of the housing is suppressed. can.

(4) In the lead-acid battery, the ventilation resistance from the accommodation chamber to the outside of the housing in the communication passage of the liquid spout may be 3.4 kPa or more. In this lead-acid battery, the ventilation resistance from the accommodation chamber to the outside of the housing in the continuous passage of the liquid spout is 3.4 kPa or more. As a result, it is possible to more effectively suppress the liquid reduction in the accommodation chamber of the housing as compared with the case where the ventilation resistance is less than 3.4 kPa.

A. Embodiment:
A-1. Constitution:
(Structure of lead-acid battery 100)
FIG. 1 is a perspective view showing an external configuration of the lead-acid battery 100 in the present embodiment, FIG. 2 is an explanatory view showing an XY plan configuration of the lead-acid battery 100, and FIG. 3 is FIG. 1 and III of FIG. It is explanatory drawing which shows the YZ cross-sectional structure of the lead-acid battery 100 at the position | III, and FIG. In addition, in FIGS. 3 and 4, for convenience, the configuration is expressed in a form different from the actual one so that the configuration of the electrode plate group 20 described later is shown in an easy-to-understand manner. 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", but the lead-acid battery 100 is actually different from such an orientation. It may be installed facing. Further, in each figure, the sheet 300 described later is shown through the facing surface 300A of the sheet 300.

Since the lead-acid battery 100 can discharge a large current in a short time and can exhibit stable performance in various environments, for example, it is mounted on a vehicle such as an automobile and is a starter at the time of starting an engine. It is used as a power supply source for various electrical components such as lights and lights. As shown in FIGS. 1 to 4, the lead-acid battery 100 includes a housing 10, a positive electrode side terminal portion 30, a negative electrode side terminal portion 40, and a plurality of electrode plate groups 20. Hereinafter, the positive electrode side terminal portion 30 and the negative electrode side terminal portion 40 are collectively referred to as “terminal portions 30 and 40”.

(Structure of housing 10)
The housing 10 has an electric tank 12 and a lid 14. The electric tank 12 is a substantially rectangular parallelepiped container having an opening 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 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 of the electric tank 12 by, for example, heat welding, a space maintained in airtightness with the outside is formed in the housing 10. The space inside the housing 10 is partitioned by a partition wall 58 into a plurality of (for example, six) cell chambers 16 arranged in a predetermined direction (X-axis direction in the present embodiment). Hereinafter, the direction in which a plurality of cell chambers 16 are arranged (X-axis direction) is referred to as a “cell arrangement direction”. The cell chamber 16 corresponds to a containment chamber within the scope of the claims.

One electrode plate group 20 is housed in each cell chamber 16 in the housing 10. Therefore, for example, when the space inside the housing 10 is divided into six cell chambers 16, the lead-acid battery 100 includes six electrode plate groups 20. Further, each cell chamber 16 in the housing 10 contains an electrolytic solution 18 containing dilute sulfuric acid, and the entire electrode plate group 20 is immersed in the electrolytic solution 18. The electrolytic solution 18 is injected into the cell chamber 16 from a liquid port plug 160, which will be described later, provided on the lid 14. The electrolytic solution 18 may contain aluminum ions in addition to dilute sulfuric acid.

Further, as shown in FIGS. 3 and 4, a mounting hole 15 that penetrates the lid 14 in the vertical direction is formed directly above each cell chamber 16 in the lid 14. A liquid spout 160 is mounted in the mounting hole 15. The lead-acid battery 100 of the present embodiment is a so-called flat type lead-acid battery in which the upper surface of the liquid spout 160 is substantially flush with the upper surface of the lid 14. Further, on the upper surface of the lid 14, a sheet 300 for suppressing the decrease of the electrolytic solution 18 in the housing 10 is arranged. The mounting hole 15 corresponds to a through hole in the claims. The detailed configuration of the liquid spout 160 and the sheet 300 will be described later.

(Structure of electrode plate group 20)
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 arranged alternately. Hereinafter, the positive electrode plate 210 and the negative electrode plate 220 are collectively referred to as “polar plate 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 a known additive.

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. The negative electrode active material 226 may further contain a known additive.

The separator 230 is made of an insulating material (eg, glass or synthetic resin). The separator 230 is arranged so as to be interposed between the positive electrode plate 210 and the negative electrode plate 220 adjacent to each other. The separator 230 may be configured as an integral member, or may be configured as a set of a plurality of members provided for each combination of the positive electrode plate 210 and the negative electrode plate 220.

The positive electrode ear portions 214 of the plurality of positive electrode plates 210 constituting the electrode plate group 20 are connected to a positive electrode side strap 52 formed of, for example, lead or a lead alloy. 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 formed of, for example, lead or a lead alloy. That is, the plurality of negative electrode plates 220 are electrically connected in parallel via the negative electrode side strap 54. Hereinafter, the positive electrode side strap 52 and the negative electrode side strap 54 are collectively referred to as “straps 52, 54”.

In the lead-acid battery 100, the negative electrode side strap 54 housed in one cell chamber 16 is one side (for example, X-axis positive) of the one cell chamber 16 via a connecting member 56 formed of, for example, lead or a lead alloy. It is connected to a positive electrode side strap 52 housed in another cell chamber 16 adjacent to the directional side). Further, the positive electrode side strap 52 housed in the one cell chamber 16 is adjacent to another cell chamber 16 on the other side (for example, the negative direction side of the X-axis) of the one cell chamber 16 via the connecting member 56. It is connected to the negative electrode side strap 54 housed in. 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. 3, the positive electrode side strap 52 housed in the cell chamber 16 located at the end on one side (X-axis negative direction side) of the cell arrangement direction is not a connecting member 56 but a positive electrode column described later. It is connected to 34. Further, as shown in FIG. 4, the negative electrode side strap 54 housed in the cell chamber 16 located at the end on the other side (X-axis positive direction side) in the cell arrangement direction is not a connecting member 56 but a negative electrode column described later. It is connected to 44.

(Structure of terminals 30 and 40)
The positive electrode side terminal portion 30 is arranged near the end of one side (X-axis negative direction side) of the housing 10 in the cell arrangement direction, and the negative electrode side terminal portion 40 is the other side of the housing 10 in the cell arrangement direction. It is arranged near the end on the side (on the positive direction side of the X-axis).

As shown in FIG. 3, the positive electrode side terminal portion 30 includes a positive electrode side bushing 32 and a positive electrode column 34. The positive electrode side bushing 32 is a substantially cylindrical conductive member having holes penetrating in the vertical direction, and is formed of, for example, a lead alloy. The lower portion of the positive electrode side bushing 32 is embedded in the lid 14 by insert molding, and the upper portion of the positive electrode side bushing 32 projects upward from the upper surface of the lid 14. 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 the hole of the positive electrode side bushing 32. The upper end portion of the positive electrode column 34 is located at substantially the same position as the upper end portion of the positive electrode side bushing 32, and is joined to the positive electrode side bushing 32 by welding, for example. The lower end of the positive electrode column 34 protrudes downward from the lower end of the positive electrode side bushing 32, and further protrudes downward from the lower surface of the lid 14, and as described above, one side in the cell arrangement direction (X-axis negative direction side). ) Is connected to the positive electrode side strap 52 housed in the cell chamber 16 located at the end.

As shown in FIG. 4, the negative electrode side terminal portion 40 includes a negative electrode side bushing 42 and a negative electrode column 44. The negative electrode side bushing 42 is a substantially cylindrical conductive member having holes penetrating in the vertical direction, and is formed of, for example, a lead alloy. The lower portion of the negative electrode side bushing 42 is embedded in the lid 14 by insert molding, and the upper portion of the negative electrode side bushing 42 projects upward from the upper surface of the lid 14. 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 the hole of the negative electrode side bushing 42. The upper end portion of the negative electrode column 44 is located at substantially the same position as the upper end portion of the negative electrode side bushing 42, and is joined to the negative electrode side bushing 42 by welding, for example. The lower end of the negative electrode column 44 projects downward from the lower end of the negative electrode side bushing 42, and further protrudes downward from the lower surface of the lid 14, and as described above, the other side in the cell arrangement direction (X-axis positive direction side). ) Is connected to the negative electrode side strap 54 housed in the cell chamber 16 located at the end.

When the lead storage battery 100 is discharged, a load (not shown) is connected to the positive electrode side bushing 32 of the positive electrode side terminal portion 30 and the negative electrode side bushing 42 of the negative electrode side terminal portion 40, and the positive electrode plate of each electrode plate group 20 is connected. The electric power generated by the reaction at 210 (reaction in which lead sulfate is produced from lead dioxide) and the reaction at the negative electrode plate 220 (reaction in which lead sulfate is produced from 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 bushing 32 of the positive electrode side terminal portion 30 and the negative electrode side bushing 42 of the negative electrode side terminal portion 40, and is supplied from the power supply. The electric power causes a reaction in the positive electrode plate 210 of each electrode plate group 20 (a reaction in which lead dioxide is generated from lead sulfate) and a reaction in the negative electrode plate 220 (a reaction in which lead is generated from lead sulfate), and the lead storage battery 100 is charged. ..

A-2. Detailed configuration of the liquid spout 160:
FIG. 5 is an enlarged explanatory view showing a YZ cross-sectional structure of a portion of the liquid spout 160 and the sheet 300. As shown in FIGS. 3 to 5, the liquid spout 160 includes a liquid spout main body 400 and a splash-proof body 500. The liquid spout main body 400 includes a tubular portion 410 and a head 420. The tubular portion 410 has a cylindrical shape extending in the vertical direction (Z-axis direction). The lower end of the tubular portion 410 is open, and one or more openings 412 are formed on the side wall portion of the tubular portion 410. The head 420 has a circular flat plate shape, and is arranged so as to seal the upper side of the tubular portion 410. The head 420 is formed with a through hole 422 that penetrates the head 420 up and down and communicates the cell chamber 16 inside the housing 10 with the outside of the housing 10. The outer diameter of the head 420 is larger than the outer diameter of the tubular portion 410, and the peripheral edge portion of the head 420 projects from the tubular portion 410 to the outer peripheral side over the entire circumference. The tubular portion 410 and the head 420 are integrally formed of, for example, resin.

The splash-proof body 500 is housed in the tubular portion 410. The splash-proof body 500 has a plurality of splash-proof plates 510. Since the splash-proof body 500 has a plurality of splash-proof plates 510, the gas exhaust path in the tubular portion 410 is in the shape of a maze. As a result, in the liquid port plug 160, the gas generated in the cell chamber 16 is relatively easily passed, but the electrolytic solution 18 in the cell chamber 16 is suppressed from easily leaking from the through hole 422 of the head 420. ing.

Further, as shown in FIG. 5, a valve body accommodating member 600 is arranged between the head portion 420 and the splash-proof body 500 in the tubular portion 410. The valve body accommodating member 600 is a cylindrical member having a substantially annular shape in a vertical direction (Z-axis direction view). The internal space of the valve body accommodating member 600 includes a filter accommodating chamber 610, a valve body accommodating chamber 620, and a lower opening 630. The filter containment chamber 610 corresponds to the outer opening in the claims, the valve body containment chamber 620 corresponds to the inner space in the claims, and the lower opening 630 corresponds to the inner opening in the claims. Corresponds to the department.

The filter storage chamber 610 is a space in which the filter 700 is housed. Specifically, the upper end of the filter accommodating chamber 610 opens on the upper surface of the valve body accommodating member 600 and communicates with the through hole 422 formed in the head 420 of the liquid spout main body 400. The diameter of the through hole 422 is smaller than the inner diameter of the filter accommodating chamber 610. The inner diameter of the filter accommodating chamber 610 is larger than the inner diameter of the valve accommodating chamber 620, and there is a vertical view (Z) between the inner peripheral surface of the filter accommodating chamber 610 and the inner peripheral surface of the valve accommodating chamber 620. An annular first stepped surface 612 is formed in the axial direction). The filter 700 is a substantially disk-shaped porous body, and is housed in the filter storage chamber 610 so as to be sandwiched between the lower surface of the head 420 and the first stepped surface 612. The filter 700 is preferably an explosion-proof filter that ignites the hydrogen gas discharged from the through hole 422 of the head 420 and prevents the hydrogen gas in the housing 10 from igniting and exploding.

The valve body accommodating chamber 620 is a space in which the valve body 650 is accommodated. Specifically, the upper end of the valve body accommodating chamber 620 is open to the filter accommodating chamber 610 side, and the lower end of the valve body accommodating chamber 620 is open to the lower opening 630 side. The inner diameter of the valve body accommodating chamber 620 is larger than the inner diameter of the lower opening 630, and there is a vertical view between the inner peripheral surface of the valve body accommodating chamber 620 and the inner peripheral surface of the lower opening 630. (Z-axis direction view), an annular second stepped surface 622 is formed. The valve body 650 is a substantially circular flat plate-shaped member. The outer diameter of the valve body 650 is smaller than the inner diameter of the valve body accommodating chamber 620 and larger than the outer diameter of the lower opening 630. Therefore, the valve body 650 is housed in the valve body accommodating chamber 620 so that the peripheral edge portion of the valve body 650 overlaps the second stepped surface 622 over the entire circumference in the vertical view. Further, the vertical thickness of the valve body 650 is smaller than the vertical height dimension of the valve body accommodating chamber 620. Therefore, the valve body 650 is housed in the valve body accommodating chamber 620 so as to be vertically displaceable.

Further, a groove 623 is formed in one or a plurality of portions of the second stepped surface 622 facing the valve body 650. Therefore, even when the valve body 650 is arranged on the second stepped surface 622, a slight gap is formed between the valve body 650 and the second stepped surface 622. Further, a convex portion 652 protruding upward is formed on the upper surface of the valve body 650. By forming the convex portion 652 on the valve body 650 in this way, for example, it is possible to prevent the valve body 650 from adhering to the filter 700 moistened by the moisture in the electrolytic solution 18 and preventing the valve function from working. can. The vertical thickness of the valve body 650 including the convex portion 652 is smaller than the vertical height dimension of the valve body accommodating chamber 620. Therefore, the valve body 650 can be displaced in the vertical direction in the valve body accommodating chamber 620 even if the convex portion 652 is formed. In the present embodiment, the gas flow path from the through hole 422 in the liquid port plug 160 to the lower opening 630 of the liquid port plug 160 is a continuous passage in the liquid port plug 160.

A-3. Detailed configuration of sheet 300:
As shown in FIGS. 1 to 5, a sheet 300 is joined to the upper surface of the lid 14 so as to cover the through hole 422 formed in each liquid spout 160. The sheet 300 has a rectangular sheet shape extending in the cell arrangement direction (X-axis direction), and is formed of a resin material such as polypropylene resin.

As shown in FIG. 2, in the sheet 300, the facing surface 300A facing the upper surface of the lid 14 includes a non-joining region 310 and a joining region 320. The non-bonded region 310 is an integral region that is not joined to the upper surface of the lid 14. Further, the non-bonded region 310 is a continuous region facing at least all of the through holes 422 of the six liquid spouts 160. In other words, the non-bonded region 310 is a continuous region that covers all of the through holes 422 of the six liquid spouts 160 in the vertical direction (Z-axis direction). Specifically, the non-junction region 310 extends linearly in the cell alignment direction (X direction), and both ends of the cell alignment direction in the non-junction region 310 extend to both ends of the cell alignment direction in the sheet 300. ing.

The joining region 320 is a region joined to the upper surface of the lid 14 via, for example, an adhesive. Further, the joining region 320 is a region (two regions in the present embodiment) other than the non-joining region 310 in the facing surface 300A of the sheet 300. With such a configuration, the non-junction region 310 in the sheet 300 communicates with the six through holes 422 and forms an exhaust path in which both ends in the cell arrangement direction (X direction) in the non-junction region 310 are open. ing. Hereinafter, each end portion in the non-joined region 310 is referred to as "open end 312 of the sheet 300".

A-4. Performance evaluation:
Performance evaluation was performed on samples of lead-acid batteries (Comparative Examples 1 to 11 and Examples 1 to 4) having different configurations regarding the filter 700, the valve structure having the valve body 650, and the seat 300. Each sample has the same configuration as the lead storage battery 100 shown in FIGS. 1 to 5 described above, except for the presence / absence and type of the filter 700, the valve structure, and the presence / absence of the seat 300.

(Evaluation methods)
In this performance evaluation, the ventilation resistance (kPa) (hereinafter referred to as “outflow ventilation resistance”) from the cell chamber 16 to the outside of the housing 10 in the communication passage of the liquid port plug 160 was measured for each sample. Here, in the configuration shown in FIG. 5, the communication passage of the liquid port plug 160 is opened downward from the upper end of the through hole 422 through the gap between the filter 700, the valve body 650, and the second stepped surface 622. It is a route to the part 630. The outflow / draft resistance of the communication passage of the liquid port plug 160 is measured by the following method. That is, each sample is placed in a test piece mounting jig (not shown). The test piece mounting jig is provided with a storage space for accommodating the test piece inside, and also includes an inlet and an outlet that communicate with the accommodation space from the outside. The liquid spout 160 of each sample is placed in the accommodation space of the test piece mounting jig, and the lower opening 630 side of the liquid spout 160 is connected to the inflow port of the test piece mounting jig. Connect the through hole 422 side of the test piece to the outlet of the test piece mounting jig. Then, air flows in from the inlet of the test piece mounting jig at an air flow rate of 5 L / min, and the pressure at the inlet and the pressure at the outlet at that time are measured with a digital pressure gauge, and the difference between the two pressures. Was defined as the outflow / ventilation resistance in the communication passage of each sample. The ventilation resistance from the outside of the housing 10 to the cell chamber 16 (hereinafter referred to as “inflow ventilation resistance”) in the communication passage of the liquid port plug 160 is such that the through hole 422 side of the liquid port plug 160 is used as a test piece mounting jig. It can be specified by connecting to the inflow port, connecting the lower opening 630 side of the liquid spout 160 to the outflow port of the test piece mounting jig, and measuring the pressure difference between the inflow port and the outflow port. ..

Further, in this performance evaluation, the reduced amount of the electrolytic solution 18 was measured for each sample. Specifically, the lead-acid battery of each sample vibrates in the vertical direction under the random vibration condition of the actual vehicle while the lead-acid battery is continuously charged for 100 hours at a charging voltage of 14.5 V (maximum charging current 25 A) under a temperature atmosphere of 70 ° C. The amount of decrease in the mass of the battery when added was measured as the amount of decrease in the electrolytic solution 18 (the amount of water in the electrolytic solution 18 discharged from the inside of the battery case 12 to the outside of the housing 10).

Further, in this performance evaluation, it was confirmed whether or not the electric tank 12 was deformed for each sample. Specifically, the degree of swelling of the electric tank 12 of each sample was visually confirmed.

(Evaluation results)
FIG. 6 is an explanatory diagram showing the result of performance evaluation of the sample. The “resin filter” in the figure means a filter having a ventilation resistance of 1.0 kPa or more and 2.0 kPa or less. The “high-density resin filter” in the figure means a filter having a ventilation resistance of 3.0 kPa or more and 6.0 kPa or less. Further, "none" in the figure means that the sample does not include any of the filter 700, the valve structure and the seat 300.

As shown in FIG. 6, in Comparative Example 1, the liquid spout 160 does not include a filter 700, a valve structure, or a seat 300. Therefore, the outflow / aeration resistance in the communication passage of the liquid port plug 160 is approximately 0 kPa, and there is almost no effect of suppressing liquid reduction. The amount of liquid reduction in Comparative Example 1 is set to "200".

Next, in Comparative Examples 2 to 4, the liquid spout 160 includes a resin filter as a filter 700, but does not have a valve structure and a sheet 300. In Comparative Examples 2 to 4, by providing the resin filter, the outflow draft resistance in the communication passage of the liquid port plug 160 was 1.0 kPa or more and 2.0 kPa or less. As a result, the amount of liquid reduction in Comparative Examples 2 to 4 was smaller than the amount of liquid reduction in Comparative Example 1, and became "100 or more and 110 or less".

Next, in Comparative Examples 5 to 7, the liquid spout 160 includes a resin filter as a filter 700, and a sheet 300 is arranged on the upper surface of the lid 14. However, Comparative Examples 5 to 7 do not have a valve structure. In Comparative Examples 5 to 7, since the sheet 300 is provided in addition to the resin filter, the liquid reduction amount of Comparative Examples 5 to 7 is further reduced from the liquid reduction amount of Comparative Examples 2 to 4 due to the liquid reduction suppressing effect of the sheet 300. However, it became "65 or more, 70 or less".

Next, in Comparative Examples 8 to 11, the liquid spout 160 includes a high-density resin filter as the filter 700 and a valve structure having a valve body 650. However, in Comparative Examples 8 to 11, the sheet 300 is not provided. In Comparative Examples 8 to 11, by providing the high-density resin filter and the valve structure, the outflow draft resistance in the communication passage of the liquid port plug 160 was 3.4 kPa or more and 6.0 kPa or less. As a result, the liquid reduction amount of Comparative Examples 8 to 11 was further reduced from the liquid reduction amount of Comparative Examples 5 to 7, and became "46 or more and 52 or less".

Next, in Examples 1 to 4, the liquid spout 160 includes a high-density resin filter and a valve structure, and a sheet 300 is arranged on the upper surface of the lid 14. In Examples 1 to 4, the outflow / ventilation resistance in the communication passage of the liquid port plug 160 is about the same as the outflow / ventilation resistance in the communication passage of the liquid port plugs 160 of Comparative Examples 8 to 11, but in Examples 1 to 4. The amount of liquid reduction was further reduced from the amount of liquid reduction in Comparative Examples 8 to 11 and became "23 or more and 26 or less".

Here, for example, in Comparative Example 8 provided with a high-density resin filter and a valve structure, the liquid reduction amount was “52”. On the other hand, the liquid reduction amount of Comparative Example 1 provided with only the resin filter was "110", and the liquid reduction amount of Comparative Example 5 provided with the sheet 300 in addition to the resin filter was "70". These things mean that the liquid reduction suppressing effect of the sheet 300 is 70/110. That is, when the sheet 300 is arranged on the lid 14, the amount of liquid reduction can be reduced by about 30% as compared with the case where the sheet 300 is not arranged on the lid 14. If this is the case, the amount of liquid reduction is calculated to be "33" (= 52 × (70/110)) when the sheet 300 is arranged on the lid 14 with respect to Comparative Example 8 provided with the high-density resin filter and the valve structure. )) Should be.

However, as shown in FIG. 6, for example, the liquid reduction amount of Example 1 provided with the sheet 300 in addition to the high-density resin filter and the valve structure is "26", which is further than the calculated liquid reduction amount "33". Low. This cause is considered to be due to the synergistic effect between the valve structure and the seat 300, as described below.

FIG. 7 is an explanatory diagram showing the relationship between the displacement of the valve body 650 in the liquid spout 160 and the seat 300. As shown in FIG. 7A, for example, in the normal state where the water content in the electrolytic solution 18 does not evaporate, the gas G generated in the cell chamber 16 when the lead storage battery 100 is charged is connected to the liquid port plug 160. It reaches the exhaust path between the lid 14 and the seat 300, and is exhausted to the outside through the open end 312 of the seat 300.

Here, as described above, the valve body 650 is housed in the valve body accommodating chamber 620 so as to be vertically displaceable. Therefore, when the internal pressure of the cell chamber 16 rises due to the gas G generated in the cell chamber 16, the valve body 650 is placed in the first position on the second step surface 622 (see FIG. 7A). Therefore, it is displaced to a second position (see (B) in FIG. 7) separated upward from the second stepped surface 622. When the valve body 650 is in the first position, only a slight gap due to the groove 623 is formed between the valve body 650 and the second stepped surface 622. On the other hand, when the valve body 650 is displaced to the second position, the gap between the valve body 650 and the second stepped surface 622 becomes large. That is, the ventilation resistance in the communication path of the liquid port plug 160 when the valve body 650 is in the second position is smaller than the ventilation resistance in the communication path of the liquid port plug 160 when the valve body 650 is in the first position. .. Therefore, when the internal pressure of the cell chamber 16 rises due to the gas G generated in the cell chamber 16, the valve body 650 is displaced to the second position, so that the outflow / ventilation resistance in the communication passage of the liquid spout 160 is relatively high. The size becomes smaller, and the gas G is easily discharged to the outside of the housing 10 through the communication passage.

Further, for example, when the lead storage battery 100 is arranged in a high temperature environment and a part of the moisture in the electrolytic solution 18 evaporates to generate water vapor, the sheet is generated by the water vapor V released through the communication passage of the liquid spout 160. A high humidity space H is formed between the 300 and the filter 700. When the high humidity space H is formed, the water vapor generated in the cell chamber 16 is less likely to enter the through hole 422 through the filter 700, so that the liquid reduction in the cell chamber 16 can be suppressed. Further, even if water vapor passes through the filter 700, it is suppressed from being liquefied and being released to the outside of the housing 10.

Further, in a state where the high humidity space H is formed, for example, when the charging of the lead storage battery 100 is stopped and gas is no longer generated from the cell chamber 16, the internal pressure of the cell chamber 16 is lowered, and the valve body 650 becomes the first. It is displaced from the position 2 to the first position (see FIG. 7 (C)). As a result, the inflow / ventilation resistance in the communication passage of the liquid port plug 160 becomes relatively large, and the backflow of gas from the high humidity space H into the through hole 422 is suppressed, so that the humidity of the space is unlikely to decrease. Become. That is, the effect of suppressing liquid reduction due to the high humidity space H is maintained. As described above, since the high humidity space H is maintained by the synergistic effect of the valve structure including the valve body 650 and the seat 300, in Examples 1 to 4, the liquid reduction amount is further larger than the calculated liquid reduction amount. It is thought that it became low. That is, according to Examples 1 to 4, it is possible to improve the liquid reduction suppressing performance while suppressing the deterioration of the discharge function of the gas G generated in the cell chamber 16 of the housing 10.

Further, in Comparative Example 11 and Example 4, swelling occurred in the electric tank 12. Therefore, the outflow / aeration resistance in the communication passage of the liquid port plug 160 is preferably 5.5 kPa or less. Further, according to the evaluation result of FIG. 6, the outflow draft resistance in the communication passage of the liquid port plug 160 is preferably 3.4 kPa or more.

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, and for example, the following modifications are also possible.

In the above embodiment, the liquid spout 160 may not be provided with the splash proof body 500. Further, in the above embodiment, the liquid spout 160 may not include the filter accommodating chamber 610 and the filter 700. Further, in the above embodiment, the groove 623 may not be formed on the second stepped surface 622 of the valve body accommodating member 600. Further, in the above embodiment, the convex portion 652 may not be formed on the valve body 650.

In the above embodiment, even when the filter 700 is a resin filter or is not provided with the filter 700, by providing the valve structure and the seat, the discharge performance of the gas G generated in the cell chamber 16 of the housing 10 can be improved. It is possible to improve the liquid reduction suppressing performance while suppressing the decrease.

In the above embodiment, one of both ends of the sheet 300 may be open and the other may be closed. With such a configuration, the liquid reduction suppressing effect of the sheet 300 can be further enhanced.

Further, in the above embodiment, the lead storage battery 100 is a flat type lead storage battery, but the present invention is not limited to this, and for example, the liquid spout 160 includes a knob portion protruding upward from the upper surface of the housing 10. , A so-called picking type lead-acid battery may be used. Further, in the above embodiment, the number of cell chambers 16 in the housing 10 is not limited to six, and may be a plurality or three or more. Further, in the present embodiment, the electric tank 12 and the lid 14 may be integrally formed.

Further, in the above embodiment, the tubular portion 410 is not limited to a cylindrical shape, and may be, for example, a square tubular portion. Further, the valve body accommodating member 600 is not limited to an annular shape, and may be, for example, a square cylinder. Further, the valve body 650 is not limited to a circular shape, and may be, for example, a rectangular shape.

Further, in the above embodiment, the outflow draft resistance in the continuous passage of the liquid port plug 160 may be larger than 5.5 kPa or smaller than 3.4 kPa.

10: Housing 12: Electric tank 14: Lid 15: Mounting hole 16: Cell chamber 18: Electrolytic solution 20: Electrode plate group 30: Positive electrode side terminal part 32: Positive electrode side bushing 34: Positive electrode pillar 40: Negative electrode side terminal part 42 : Negative electrode side bushing 44: Negative electrode pillar 52: Positive electrode side strap 54: Negative electrode side strap 56: Connection member 58: Partition wall 100: Lead storage battery 160: Liquid port plug 210: Positive electrode plate 212: Positive electrode current collector 214: Positive electrode ear part 216 : Positive electrode active material 220: Negative electrode plate 222: Negative electrode current collector 224: Negative electrode ear part 226: Negative electrode active material 230: Separator 300: Sheet 300A: Facing surface 310: Non-bonded region 312: Open end 320: Bonded region 400: Liquid Mouth plug body 410: Cylindrical part 412: Opening 420: Head 422: Through hole 500: Splash-proof body 510: Splash-proof plate 600: Valve body accommodating member 610: Filter accommodating chamber 612: First step surface 620: Valve body accommodation chamber 622: Second step surface 623: Groove 630: Lower opening 650: Valve body 652: Convex part 700: Filter G: Gas H: Space V: Water vapor

Claims (3)

It ’s a lead-acid battery.
A housing in which a containment chamber is formed and a through hole communicating with the containment chamber is formed,
The positive and negative electrodes arranged in the accommodation chamber,
A liquid spout plug that is attached to the through hole formed in the housing and has a communication passage that communicates with the storage chamber.
A sheet arranged on the surface of the housing so as to face the communication passage formed in the liquid spout is provided.
The facing surface of the sheet facing the housing is not joined to the housing and is not joined to the housing, and the edge of the sheet is connected to the communication passage of the liquid spout. Has a non-joint region extending to the portion,
The communication passage of the liquid spout is
The internal space formed inside the liquid spout and
An outer opening that opens to the outer surface side of the housing and communicates with the internal space,
It includes an inner opening that opens to the accommodation chamber side and communicates with the internal space, and the opening area is smaller than the area of the cross section of the internal space orthogonal to the axial direction of the liquid port plug.
Further, in the internal space, a first position in which a part of the inner space is in contact with the peripheral portion of the inner opening and a gap is formed between the peripheral portion and a second position separated from the outer opening side. Equipped with a displaceable valve body,
A lead-acid battery in which the ventilation resistance of the liquid spout from the outside of the housing to the housing chamber in the communication passage is larger than the ventilation resistance from the storage chamber to the outside of the housing in the communication passage. The lead-acid battery according to claim 1.
A lead-acid battery having a ventilation resistance of 5.5 kPa or less from the accommodation chamber to the outside of the housing in the communication passage of the liquid port plug. The lead-acid battery according to claim 1 or 2 .
A lead-acid battery having a ventilation resistance of 3.4 kPa or more from the accommodation chamber to the outside of the housing in the communication passage of the liquid port plug.

Images