Lead acid storage battery

Abstract

To reduce such a possibility that an electrolyte accumulated in an exhaust passage leaks to the outside even if the electrolyte flows into an exhaust adapter accommodation space.SOLUTION: A lead acid storage battery includes: a battery case; a lid part closing an opening of the battery case; and an exhaust adapter 21. The lid part includes: an accommodation space formed to a side face of the lid part in a concave shape and accommodating the exhaust adapter 21 therein; an exhaust passage formed inside the lid part and introducing gas generated in each cell chamber into the accommodation space; and a communication port (internal space of a first cylindrical part) provided in each cell chamber and communicating between the cell chamber and the exhaust passage. The exhaust adapter includes: an adapter lid part 21A covering the accommodation space and having an exhaust port 21D; a body part 21B having a gas inlet port 21M communicating with the exhaust passage and opening upward and inner passages (21L, 21Q) introducing gas flowing in from the gas inlet port 21M into an exhaust port 21D, the body part being integrated with the adapter lid part 21A; and a first filter 21C arranged in the internal passage.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a lead-acid battery. [Background technology]

[0002] Conventionally, there is known a lead-acid battery having a plurality of cell chambers in which electrodes and an electrolyte are contained (for example, see Patent Document 1). Specifically, the lead-acid battery described in Patent Document 1 has a plurality of electrode plate groups prepared by stacking a plurality of positive and negative electrode plates with separators interposed therebetween, and is housed together with an electrolyte in a plurality of cell chambers separated from each other in a battery container.

[0003] The lead-acid battery described in Patent Document 1 has a plurality of liquid ports (first holes) provided at positions corresponding to those directly above each cell chamber, first side holes (second holes) provided intermittently on either side of the first holes, and a discharge port (third hole) connected to the second holes. The third holes are closed with a closing part (second cover). The second cover is made up of a flat plate portion having a perforation (fifth hole) communicating with the third hole and covering the third hole, a rib (cylindrical portion) protruding in a substantially vertical direction from the flat plate portion so as to surround the fifth hole, and a filter made of a porous body attached to the space surrounded by the flat plate portion and the cylindrical portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5838382 Summary of the Invention [Problem to be solved by the invention]

[0005] The lead-acid battery described in Patent Document 1 has room for improvement in terms of reducing the possibility of the electrolyte pooled in the intermittently provided first lateral holes (second holes) leaking to the outside. This specification discloses a technique for reducing the possibility of electrolyte leaking to the outside even if it accumulates in the exhaust passage and flows into the accommodation space of the exhaust adapter. [Means for solving the problem]

[0006] The lead-acid battery disclosed in this specification comprises electrodes, an electrolyte, a battery case whose interior is divided into a plurality of cell chambers that house the electrodes and the electrolyte and that is open upward, a lid that covers the opening of the battery case, and an exhaust adapter, wherein the lid has a recessed shape formed on a side surface of the lid and has a storage space in which the exhaust adapter is housed, an exhaust passage formed inside the lid that guides gas generated in each of the cell chambers to the storage space, and a communication port that is provided for each of the cell chambers and connects the cell chamber to the exhaust passage, and the exhaust adapter covers the storage space and has an adapter lid that has an exhaust port, a gas inlet that communicates with the exhaust passage and opens upward, and an internal passage that guides gas that has flowed in from the gas inlet to the exhaust port, and has a main body that is integrated with the adapter lid, and a filter that is arranged in the internal passage. Effect of the Invention

[0007] According to the above configuration, even if the electrolyte accumulated in the exhaust passage flows into the accommodation space of the exhaust adapter, the possibility of the electrolyte leaking to the outside can be reduced. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a lead-acid battery according to a first embodiment; [Diagram 2] Perspective view of the battery case [Diagram 3] Perspective view of the lid from below [Figure 4] Cross-section of a lead-acid battery [Diagram 5] Cross-section of a lead-acid battery [Figure 6] Partial cross-sectional view of the lid [Figure 7] Cross-section of the lid [Figure 8] Perspective view of exhaust adapter [Figure 9] Exhaust adapter cross section [Figure 10] Perspective view of the vent plug [Figure 11] Partial cross-sectional view of line AA shown in Figure 7 [Figure 12] 1 is a cross-sectional view of an exhaust adapter according to a comparative example; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Overview of the embodiment of the present disclosure] (1) A lead-acid battery according to an embodiment includes electrodes, an electrolyte, a battery case whose interior is divided into a plurality of cell chambers that house the electrodes and the electrolyte and that is open upward, a lid that covers the opening of the battery case, and an exhaust adapter, wherein the lid has a recessed shape formed on a side of the lid and includes a storage space in which the exhaust adapter is housed, an exhaust passage formed inside the lid that guides gas generated in each of the cell chambers to the storage space, and a communication port that is provided for each of the cell chambers and connects the cell chamber to the exhaust passage, and the exhaust adapter covers the storage space and includes an adapter lid that has an exhaust port, a gas inlet that communicates with the exhaust passage and opens upward, and an internal passage that guides gas that has flowed in from the gas inlet to the exhaust port, and includes a main body that is integrated with the adapter lid, and a filter that is arranged in the internal passage.

[0010] In recent years, lead-acid batteries are sold through mail order sales (so-called EC sales) via the Internet, etc., and lead-acid batteries are sometimes delivered in units of one. When a lead-acid battery is delivered in units of one, the delivery worker may tilt or fall the lead-acid battery, and at that time, the electrolyte in the cell chamber may flow into the exhaust passage and accumulate in the exhaust passage. Then, after the delivered lead-acid battery is mounted on a vehicle or the like and used, gas may be generated in the cell chamber, and the electrolyte that has accumulated in the exhaust passage may be pushed out by the gas and flow into the accommodation space of the exhaust adapter. After the lead-acid battery is mounted on a vehicle, etc., the electrolyte may accumulate in the exhaust passage due to vibration, and may be pushed out by the gas and flow into the accommodation space.

[0011] In the closing part (second cover) described in the above-mentioned Patent Document 1, the cylindrical part to which the filter is attached opens in the horizontal direction, so when the electrolyte flows into the recess in which the closing part is housed, the liquid level of the electrolyte that flows in easily reaches the opening of the cylindrical part. Therefore, the electrolyte easily reaches the filter. Once the electrolyte reaches the filter, it does not return, but goes out together with the gas.

[0012] In the lead-acid battery described in (1) above, the gas inlet opens upward, so the gas inlet can be positioned higher than in the lead-acid battery described in Patent Document 1. If the gas inlet is positioned higher, even if the electrolyte accumulated in the exhaust passage flows into the storage space, the liquid level is unlikely to reach the gas inlet, so the amount of electrolyte that can be stored in the storage space increases. Therefore, according to the lead-acid battery described in (1) above, even if the electrolyte accumulated in the exhaust passage flows into the accommodation space of the exhaust adapter, the possibility of the electrolyte leaking to the outside can be reduced.

[0013] (2) The lead-acid battery according to (1) above, wherein the internal passage has a first internal passage extending horizontally from the exhaust port and a second internal passage extending downward from the gas inlet and connected to the first internal passage, and the filter may be disposed in the second internal passage.

[0014] In some conventional exhaust adapters, a filter is disposed below the first internal passage, and the gas inlet is open downward. According to the lead-acid battery described in (2) above, since the filter is disposed above the first internal passage, the gas inlet can be opened facing upward.

[0015] (3) In the lead-acid battery according to (1) or (2) above, an opening surface of the gas inlet may be located higher than the exhaust passage.

[0016] In the lead-acid battery described in (3) above, the opening surface of the gas inlet is located higher than the exhaust passage, so that even if the electrolyte that has accumulated in the exhaust passage flows into the accommodation space, it is more likely to return to the exhaust passage without entering the gas inlet, thereby further reducing the possibility of the electrolyte leaking to the outside. If the opening surface of the gas inlet is made higher than the exhaust passage, the distance between the opening surface of the gas inlet and the ceiling surface of the storage space becomes narrower, which has the effect of making it more difficult for the electrolyte that has flowed into the storage space to enter the gas inlet.

[0017] (4) In the lead-acid battery according to any one of (1) to (3) above, when the main body of the exhaust adapter is regarded as a solid object, the volume of the portion of the main body below the liquid level of the electrolyte that has flowed into the storage space immediately before the electrolyte begins to flow into the gas inlet may be greater than the volume of the exhaust passage.

[0018] According to the lead-acid battery described in (4) above, even if all of the electrolyte accumulated in the exhaust passage flows into the storage space, the liquid level does not reach the gas inlet, so that the possibility of the electrolyte leaking to the outside can be further reduced.

[0019] (5) In the lead-acid battery according to any one of (1) to (4) above, the gas inlet may be provided with a notch.

[0020] According to the lead-acid battery described in (5) above, a notch is provided at the gas inlet. Therefore, even if electrolyte accumulates on the filter, the electrolyte returns to the storage space of the exhaust adapter or the exhaust passage, thereby reducing the possibility of the electrolyte leaking to the outside.

[0021] [Details of the embodiment of the present disclosure] The present disclosure will be described in detail below with reference to the exemplary embodiments. The present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0022] <Embodiment 1> In the following description, the front-rear direction, left-right direction, and up-down direction are based on the front-rear direction, left-right direction, and up-down direction shown in Fig. 1. In the following description, the reference numerals in the drawings may be omitted for the same components, with some exceptions.

[0023] (1) Overall structure of lead-acid battery A lead-acid battery 1 according to the first embodiment will be described with reference to Fig. 1. The lead-acid battery 1 is mounted on an automobile and supplies power to an engine starting device (starter motor) and auxiliary devices (electric power steering, electric brakes, headlights, air conditioner, etc.). The lead-acid battery 1 is of a flooded type and includes a synthetic resin battery case 11 that is open on the top, and a synthetic resin lid 12 that covers the opening of the battery case 11.

[0024] 2, the battery case 11 has a rectangular shape when viewed from above, and has five partition walls 11A formed therein at equal intervals in the left-right direction. The interior of the battery case 11 is divided into six cell chambers 13 by these partition walls 11A.

[0025] 1, the lid portion 12 has a frame 12A extending downward from four sides. A protruding portion 12B protruding upward in a T-shape is formed on the lid portion 12. A positive electrode external terminal 14P is fixed to one of two corners on the upper surface of the lid portion 12 where the protruding portion 12B is not formed, and a negative electrode external terminal 14N is fixed to the other corner.

[0026] 3, the protruding portion 12B of the lid portion 12 is formed as a recess that is recessed upward in a T-shape when viewed from below. Five partition walls 12C are formed on the back surface of the lid portion 12 in correspondence with the partition walls 11A formed on the battery case 11.

[0027] 4, the lower end surface of the partition wall 12C formed on the back surface of the lid portion 12 is connected to the upper end surface of the partition wall 11A formed in the battery case 11 by thermal welding or the like. This separates the cell chambers 13. Each cell chamber 13 contains a plate group 15 (an example of an electrode) and an electrolyte 16 made of dilute sulfuric acid. The electrolyte 16 also contains water. The plate group 15 is made up of positive electrode plates 15P and negative electrode plates 15N that are alternately stacked in the horizontal direction with a separator 15C sandwiched between them. Each of the plates 15P and 15N is made up of a lattice body filled with an active material.

[0028] As shown in Fig. 5, an ear 17 is provided at the upper end of each of the electrode plates 15P, 15N. As shown in Fig. 4, the electrode plates 15P, 15N of the same polarity in one cell chamber 13 are connected at the ear 17 by a strap 18. The strap 18 is, for example, a plate shape that is long in the left-right direction, and one set of straps 18 is provided for each cell chamber 13, one for the positive electrode and one for the negative electrode.

[0029] As shown in Fig. 2, an opening 12K is formed in the partition wall 11A. As shown in Fig. 4, the positive and negative straps 18 of adjacent cell chambers 13 are connected by welding or the like through the opening 12K. This connects the electrode plate groups 15 of each cell chamber 13 in series.

[0030] The positive external terminal 14P and the negative external terminal 14N will be described with reference to FIG. 5. The positive external terminal 14P and the negative external terminal 14N have substantially the same structure, so the positive external terminal 14P will be described here as an example. The positive external terminal 14P includes a bushing 14P_1 and a pole 14P_2. The bushing 14P_1 is made of a metal such as a lead alloy and is formed in a cylindrical shape. The upper part of the bushing 14P_1 protrudes upward from the upper surface of the lid portion 12. The pole 14P_2 is made of a metal such as a lead alloy and is formed in a cylindrical shape. The pole 14P_2 is inserted inside the bushing 14P_1, and its lower part protrudes downward from the bushing 14P_1. The lower end of the pole 14P_2 is connected to a positive strap 18 housed in the leftmost cell chamber 13 by welding or the like.

[0031] (2) Inlet port As shown in Fig. 1, the lid portion 12 is provided with liquid filling ports 12D at positions above each cell chamber 13. These liquid filling ports 12D are aligned in a straight line in the left-right direction. The liquid filling ports 12D are openings for injecting the electrolyte 16 into each cell chamber 13, and are closed by liquid filling port plugs 19. Moisture contained in the electrolyte 16 evaporates and turns into water vapor (gas), which may be exhausted to the outside through an exhaust passage 20 described below. When the gas is exhausted and the electrolyte 16 decreases, rehydration liquid is replenished through the liquid filling port 12D.

[0032] Fig. 6 shows cross sections of the first to third liquid filling ports 12D from the left. In Fig. 6, the first liquid filling port 12D from the left is not blocked by a liquid filling port plug 19. The liquid filling port 12D has a circular recess 12D_1, a circular opening 12D_2 formed in the bottom wall of the recess 12D_1, and a first cylindrical portion 12E formed on the lower surface of the lid portion 12.

[0033] The first cylindrical portion 12E surrounds the opening 12D_2 and extends cylindrically downward. The inner diameter of the first cylindrical portion 12E is the same as the inner diameter of the opening 12D_2. A first screw thread 12F that projects in a spiral shape is formed on the inner peripheral surface of the first cylindrical portion 12E. The first screw thread 12F is a single thread that does not complete one revolution around the inner peripheral surface of the first cylindrical portion 12E.

[0034] 3, slits 12G extending upward from the lower end of first cylindrical portion 12E are formed on the left and right sides of first cylindrical portion 12E. Slits 12G are provided to allow gas generated in cell chamber 13 to flow into first cylindrical portion 12E even when the liquid level of electrolyte 16 is above the lower end of first cylindrical portion 12E.

[0035] (3) Exhaust passage 7, a plurality of exhaust passages 12H are integrally formed on the lower surface of the cover portion 12. Specifically, the exhaust passages 12H are provided between adjacent first cylindrical portions 12E, to the left of the leftmost first cylindrical portion 12E, and to the right of the rightmost first cylindrical portion 12E.

[0036] Each exhaust passage portion 12H is formed with an exhaust passage 20 having a circular cross section that penetrates in the left-right direction. The multiple exhaust passages 20 are passages for guiding gas generated in each cell chamber 13 to the storage space 12J described below, and are connected together via the internal space of the first cylindrical portion 12E. Each cell chamber 13 is connected to the exhaust passage 20 via the internal space of the first cylindrical portion 12E. The internal space of the first cylindrical portion 12E is an example of a communication port that connects the cell chamber 13 and the exhaust passage 20.

[0037] (4) Exhaust adapter storage space As shown in Fig. 6, a storage space 12J is formed in a recessed shape on the left side surface of the cover portion 12 to store an exhaust adapter 21 (more specifically, a main body portion 21B of the exhaust adapter 21), which will be described later. The storage space 12J is substantially rectangular when viewed from the left. The leftmost exhaust passage 20 opens into the back wall of the storage space 12J when viewed from the left.

[0038] As shown in Fig. 7, a storage space 12J is also formed in a recessed shape on the right side surface of the lid portion 12. When viewed from the right, the rightmost exhaust passage 20 opens into the back wall of the right storage space 12J. However, only the left storage space 12J accommodates the exhaust adapter 21, and the right storage space 12J is sealed by welding a plate-shaped sealing member 40 made of synthetic resin, for example. The reason that the storage spaces 12J are provided on the left and right is to enable selection of which side to exhaust gas from depending on the vehicle in which the lead-acid battery 1 is mounted.

[0039] The exhaust adapter 21 may be accommodated in the right accommodation space 12J, and the left accommodation space 12J may be sealed. Alternatively, the exhaust adapter 21 may be accommodated in either the left or right accommodation space 12J.

[0040] (5) Exhaust adapter The exhaust adapter 21 will be described with reference to Figures 8 and 9. The exhaust adapter 21 is a component that holds a first filter 21C (an example of a filter) described later. As described above, it is assumed here that the exhaust adapter 21 is accommodated in the left accommodation space 12J.

[0041] As shown in FIG. 9, the exhaust adapter 21 has an adapter cover part 21A that covers the left accommodation space 12J, a main body part 21B, and a first filter 21C. The adapter lid 21A is a plate-shaped member that is slightly larger than the accommodation space 12J when viewed from the left. The adapter lid 21A is made of synthetic resin and is fixed to the lid 12 by thermal welding so as to close the accommodation space 12J. The adapter lid 21A has a circular exhaust port 21D. Main body 21B is also made of synthetic resin and is integrated with adapter lid 21A by heat welding, adhesion, etc. Main body 21B and adapter lid 21A may be formed as a single component from the beginning, or may be simply combined without being adhered.

[0042] As shown in FIG. 8, a flat surface 21E is formed on the surface of the main body 21B facing the right. A welded portion 21F is formed on the flat surface 21E, protruding toward the right. The welded portion 21F has an arc-shaped portion that corresponds to the lower half of a circle, and portions that extend linearly from both ends of the arc-shaped portion toward the other ends. The welded portion 21F melts and the main body 21B is heat-welded to the back wall of the left storage space 12J. Even when the main body 21B is heat-welded, the exhaust passage 20 is not completely blocked, and a gap is formed between the exhaust passage 20 and the main body 21B. Gas and electrolyte 16 flow into the storage space 12J through the gap.

[0043] As shown in FIG. 9, the main body 21B is largely composed of an upper part and a lower part. A first internal passage 21L having a circular cross section and extending from the exhaust port 21D to the right (horizontally) is formed in the lower part of the main body 21B. A second internal passage 21Q having a circular cross section and extending downward is formed in the upper part. An upper end 21M of the second internal passage 21Q is a gas inlet (hereinafter referred to as the gas inlet 21M). The gas inlet 21M opens upward. The inner circumferential surface of the gas inlet 21M is formed in a tapered shape with an inner diameter that decreases downward. The gas inlet 21M communicates with the exhaust passage 20 via the accommodation space 12J. A cutout 30 is provided in the portion of the main body 21B that constitutes the gas inlet 21M. A bottom surface 30A of the cutout 30 is formed as a slope that slopes downward toward the outside. Although Fig. 9 shows a case in which the cutout 30 is formed so as to open toward the right (in other words, toward the exhaust passage 20), the position of the cutout 30 is not limited to this. For example, the cutout 30 may be formed so as to open toward the front side, or toward the rear side.

[0044] The first internal passage 21L and the second internal passage 21Q are separated by a partition wall 21N. An opening 21P that connects the first internal passage 21L and the second internal passage 21Q is formed in the right portion of the partition wall 21N.

[0045] The first filter 21C is disposed in the second internal passage 21Q. The first filter 21C is installed for the purpose of explosion-proofing the liquid from the outside. The first filter 21C also plays a role of increasing the exhaust resistance of the gas generated in the cell chamber 13 in cooperation with the second filter 19K disposed in the liquid vent plug 19 described later. The first filter 21C is formed in a disk shape having a certain thickness. The diameter of the first filter 21C is approximately equal to the inner diameter of the second internal passage 21Q. The first filter 21C is, for example, a porous body having continuous pores. The porous body is a sintered body of ceramics such as alumina or resin particles such as polypropylene, and the average pore size is several tens to several hundreds of μm.

[0046] The gas that flows into the second internal passage 21Q from the gas inlet 21M passes through the first filter 21C, then flows into the first internal passage 21L from the opening 21P, and is exhausted to the outside from the exhaust port 21D. The first internal passage 21L and the second internal passage 21Q are an example of an internal passage that guides the gas that flows in from the gas inlet 21M to the exhaust port 21D.

[0047] As shown in Fig. 6, when the exhaust adapter 21 is accommodated in the accommodation space 12J, the main body portion 21B is located above the bottom surface of the accommodation space 12J, and a gap is generated between the main body portion 21B and the bottom surface of the accommodation space 12J. There are also gaps between the main body portion 21B and the front side surface of the accommodation space 12J, and between the main body portion 21B and the rear side surface of the accommodation space 12J. There is also a partial gap between the main body portion 21B and the right side surface of the accommodation space 12J. The electrolyte 16 that flows into the accommodation space 12J accumulates in these gaps.

[0048] There is also a gap between main body 21B and the ceiling surface of storage space 12J, and gas that has flowed into storage space 12J flows through this gap into gas inlet 21M. When the liquid level of electrolyte 16 that has flowed into storage space 12J becomes higher than gas inlet 21M, electrolyte 16 enters gas inlet 21M through the gap. The opening surface of gas inlet 21M is located higher than exhaust passage 20.

[0049] (6) Liquid vent plug As shown in Figure 10, the liquid inlet plug 19 has a disk-shaped plug member 19A that covers the liquid inlet 12D, a second cylindrical portion 19B that extends cylindrically downward from the underside of the plug member 19A, and a gasket 19C attached to the outer periphery of the upper end of the second cylindrical portion 19B.

[0050] As shown in FIG. 1, a cross-shaped groove 19D is formed on the top surface of the vent plug 19 for screwing the vent plug 19 into the inside of the first cylindrical portion 12E with a coin or the like.

[0051] As shown in Fig. 10, the second cylindrical portion 19B is composed of an upper portion 19E, a middle portion 19F, and a lower portion 19G. A second thread 19H is formed on the outer circumferential surface of the middle portion 19F. As shown in Fig. 6, the liquid outlet plug 19 inserted from the liquid inlet 12D is fixed to the lid portion 12 by screwing the second thread 19H into the first thread 12F of the first cylindrical portion 12E.

[0052] As shown in Fig. 6, the outer diameter of the upper portion 19E of the second cylindrical portion 19B is smaller than the inner diameter of the first cylindrical portion 12E. Therefore, a gap is generated between the inner peripheral surface of the first cylindrical portion 12E and the outer peripheral surface of the upper portion 19E of the second cylindrical portion 19B. The outer diameter of the lower portion 19G of the second cylindrical portion 19B is also smaller than the inner diameter of the first cylindrical portion 12E. Therefore, a gap is also generated between the inner peripheral surface of the first cylindrical portion 12E and the outer peripheral surface of the lower portion 19G.

[0053] As shown in Fig. 10, slits 19J are formed on the left and right sides of the lower portion 19G, extending upward from the lower end of the second cylindrical portion 19B. The slits 19J serve as entrances through which gas generated in the cell chamber 13 enters the interior of the second cylindrical portion 19B. The upper end of the slits 19J reaches the lower end of the second screw thread 19H formed in the middle portion 19F, and the lower end of the second screw thread 19H is cut out at a position that overlaps with the upper end of the slits 19J.

[0054] 6, a second filter 19K having a disk shape and a certain thickness is accommodated inside an upper portion 19E of the second cylindrical portion 19B. The material of the second filter 19K is the same as that of the first filter 21C.

[0055] 6 and 10, circular through-holes 19L are formed on the left and right sides of the upper part 19E of the second cylindrical portion 19B at positions corresponding to the outer circumferential surface of the second filter 19K. The through-holes 19L are holes for allowing gas that is generated in the cell chamber 13 and passes through the second filter 19K to escape to the exhaust passage 20. A splash guard 19M is accommodated inside the second cylindrical portion 19B below the second filter 19K. The splash guard 19M is intended to form a labyrinth-like passage inside the second cylindrical portion 19B in order to prevent the mist of the electrolyte 16 generated in the cell chamber 13 from reaching the second filter 19K.

[0056] 10, a restricting portion 19N that restricts the vertical position of the packing 19C is integrally provided on the outer circumferential surface of the upper portion 19E of the second cylindrical portion 19B. The restricting portion 19N goes around the second cylindrical portion 19B except for the portion where the circular through hole 19L of the second cylindrical portion 19B is formed. The packing 19C is formed into a ring shape and made of synthetic rubber, etc. As shown in Fig. 6, when the liquid inlet plug 19 is inserted into the liquid inlet 12D, the gap between the upper surface of the recess 12D_1 of the liquid inlet 12D and the lower surface of the disc-shaped plug member 19A is airtightly sealed by the packing 19C.

[0057] (7) Gas exhaust flow The flow of gas exhaust will be described with reference to Fig. 11. For convenience, the leftmost cell chamber 13 of the six cell chambers 13 shown in Fig. 11 is referred to as the first cell chamber 13_1, and the remaining cell chambers are referred to as the second cell chamber 13_2 to the sixth cell chamber 13_6 in order moving to the right. Taking the fourth cell chamber 13_4 as an example, gas generated in the fourth cell chamber 13_4 flows into the exhaust passage 20 from the through hole 19L of the vent plug 19. The gas that has flowed into the exhaust passage 20 flows through the exhaust passage 20 to the left. Gas generated in the cell chambers 13 to the right of the fourth cell chamber 13_4 (the fifth cell chamber 13_5 and the sixth cell chamber 13_6) flows to the left through the gap between the first cylindrical portion 12E and the second cylindrical portion 19B of the fourth cell chamber 13_4. The gas flowing to the left flows into the left storage space 12J and is exhausted to the outside.

[0058] (8) Total volume of the exhaust passage and maximum storage capacity of the storage space The total volume of the exhaust passages 20 refers to the total value of the volumes of the multiple exhaust passages 20 described above. The maximum storage capacity of the accommodation space 12J refers to the volume obtained by subtracting the volume of the portion of the main body 21B below the liquid level of the electrolyte 16 in the accommodation space 12J just before the electrolyte 16 that has flowed into the accommodation space 12J starts to flow into the gas inlet 21M from the volume of the portion of the main body 21B below the liquid level when the main body 21B of the exhaust adapter 21 is considered as a solid object. The liquid level of the electrolyte 16 just before it starts to flow into the gas inlet 21M corresponds to the height of the inner edge of the bottom surface 30A of the notch 30 described above. If the notch 30 did not exist, it would correspond to the height of the opening surface of the gas inlet 21M. The maximum storage amount of the storage space 12J can also be expressed as the maximum amount of electrolyte 16 that can be stored in the storage space 12J without entering the gas inlet 21M when the electrolyte 16 flows into the storage space 12J.

[0059] The maximum storage capacity of the storage space 12J can be set by widening the front-to-rear width (front-to-rear width shown in FIG. 1) of the storage space 12J, deepening the depth (left-to-right width shown in FIG. 1), or lowering the bottom surface of the storage space 12J. The lid 12 is set so that the maximum storage capacity of the storage space 12J is larger than the total volume of the exhaust passage 20. For this reason, even if all of the electrolyte 16 that has accumulated in the exhaust passage 20 flows into the storage space 12J, the liquid level does not reach the gas inlet 21M.

[0060] (9) Effects of the embodiment In the lead-acid battery 1 according to the first embodiment, the gas inlet 21M opens upward, so that the gas inlet 21M can be positioned higher than in the lead-acid battery described in Patent Document 1. If the gas inlet 21M is positioned higher, even if the electrolyte 16 accumulated in the exhaust passage 20 flows into the accommodation space 12J, the liquid level is unlikely to reach the gas inlet 21M, so that the amount of electrolyte 16 that can be accumulated in the accommodation space 12J increases. Therefore, according to the lead-acid battery 1, even if the electrolyte 16 accumulated in the exhaust passage 20 flows into the accommodation space 12J of the exhaust adapter 21, the possibility of the electrolyte 16 leaking out can be reduced.

[0061] In the lead-acid battery 1, since the first filter 21C is disposed above the first internal passage 21L, the gas inlet 21M can be opened facing upward.

[0062] With reference to a comparative example shown in FIG. 12, the effect of opening the gas inlet 21M facing upward will be described. In the exhaust adapter 121 according to the comparative example, an internal passage 121B extends horizontally from an exhaust port 121A, and a filter 121C is disposed below the internal passage 121B. The gas inlet 121D opens downward. If the gas inlet 121D opens downward, the distance from the gas inlet 121D to the bottom surface of the accommodation space 12J becomes shorter, so that when the electrolyte 16 flows into the accommodation space 12J, the amount of electrolyte 16 that can be stored in the accommodation space 12J without entering the gas inlet 121D decreases. In contrast, since the gas inlet 21M of the exhaust adapter 21 according to the first embodiment opens upward, the amount of electrolyte 16 that can be stored in the accommodation space 12J is greater than that of the exhaust adapter 121 according to the comparative example. In other words, according to the exhaust adapter 21 of embodiment 1, the up-down relationship between the gas inlet 21M and the first filter 21C is reversed compared to the exhaust adapter 121 of the comparative example, so that the amount of electrolyte 16 that can be stored in the storage space 12J can be increased.

[0063] In the lead-acid battery 1, since the opening surface of the gas inlet 21M is located higher than the exhaust passage 20, even if the electrolyte 16 accumulated in the exhaust passage 20 flows into the accommodation space 12J, it is highly likely that the electrolyte 16 will return to the exhaust passage 20 without entering the gas inlet 21M. This further reduces the possibility that the electrolyte 16 will leak to the outside. If the opening surface of the gas inlet 21M is made higher than the exhaust passage 20, the distance between the opening surface of the gas inlet 21M and the ceiling surface of the storage space 12J becomes narrower, which has the effect of making it more difficult for the electrolyte 16 that has flowed into the storage space 12J to enter the gas inlet 21M.

[0064] According to the lead-acid battery 1, even if all of the electrolyte 16 accumulated in the exhaust passage 20 flows into the accommodation space 12J, the liquid level does not reach the gas inlet 21M, so the possibility of the electrolyte 16 leaking to the outside can be further reduced.

[0065] According to the lead-acid battery 1, since the gas inlet 21M is provided with the notch 30, even if the electrolyte 16 accumulates on the first filter 21C, the electrolyte 16 returns to the storage space 12J of the exhaust adapter 21 or the exhaust passage 20, thereby reducing the possibility of the electrolyte 16 leaking to the outside.

[0066] <Other embodiments> The technology disclosed in this specification is not limited to the embodiments described above and in the drawings, and for example, the following embodiments are also included in the technical scope disclosed in this specification.

[0067] (1) In the above embodiment, the opening surface of the gas inlet 21M is located at a higher position than the exhaust passage 20. However, the opening surface of the gas inlet 21M may be located at the same height as the exhaust passage 20 or at a lower position than the exhaust passage 20.

[0068] (2) In the above embodiment, an example was given of a case where the maximum storage capacity of the storage space 12J is larger than the total volume of the exhaust passage 20, but the maximum storage capacity of the storage space 12J may be the same as the total volume of the exhaust passage 20, or may be smaller than the total volume of the exhaust passage 20.

[0069] (3) In the above embodiment, the lid portion 12 has a single structure, but the lid portion 12 may have a double structure including an upper lid and a lower lid. The exhaust passage 20 may be formed between the upper lid and the lower lid.

[0070] (4) The vent plug 19 illustrated in the above embodiment is just an example. The vent plug 19 is not limited to the above embodiment, and any appropriate structure can be adopted. [Explanation of symbols]

[0071] 1: Lead acid battery 11: Battery case 12: Lid 12E: First cylindrical portion (an example of a communication port) 12J: Containment Space 13: Cell Room 15: Plate group (example of electrodes) 16: Electrolyte 20: Exhaust passage 21: Exhaust adapter 21A: Adapter cover 21B: Main body 21C: First filter (an example of a filter) 21D: Exhaust port 21L: First internal passage (an example of an internal passage) 21M: Gas inlet 21Q: Second internal passage (an example of an internal passage) 30: Cutout

Claims

1. An electrode; An electrolyte; an upper open battery case, the inside of which is divided into a plurality of cell chambers for accommodating the electrodes and the electrolyte; A lid portion that closes the opening of the battery case; Exhaust adapter, Equipped with The lid portion is a housing space formed in a recessed shape on a side surface of the lid portion and housing the exhaust adapter; an exhaust passage formed inside the lid portion and configured to guide gas generated in each of the cell chambers to the storage space; a communication port provided for each of the cell chambers and communicating the cell chamber with the exhaust passage; having The exhaust adapter is an adapter cover portion that covers the accommodation space and has an exhaust port; a main body portion that is integrated with the adapter cover portion and that has a gas inlet that is in communication with the exhaust passage and opens upward, and an internal passage that guides the gas that has flowed in from the gas inlet to the exhaust port; a filter disposed in the internal passage; A lead-acid battery having

2. 2. The lead-acid battery according to claim 1, wherein the internal passage includes a first internal passage extending horizontally from the exhaust port and a second internal passage extending downward from the gas inlet port and connected to the first internal passage, and the filter is disposed in the second internal passage.

3. 3. The lead-acid battery according to claim 1, wherein an opening surface of the gas inlet is located at a position higher than the exhaust passage.

4. 3. The lead-acid battery according to claim 1, wherein, when the main body of the exhaust adapter is regarded as a solid object, a volume obtained by subtracting a volume of a portion of the main body below the liquid level of the electrolyte in the storage space immediately before the electrolyte that has flowed into the storage space begins to flow into the gas inlet from a volume of the portion of the main body below the liquid level is greater than a volume of the exhaust passage.

5. The lead-acid battery according to claim 1 or 2, wherein a notch is provided in the gas inlet.

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