JP6697699B2 - Lead acid battery - Google Patents

Description

  The present invention relates to a technique for suppressing corrosion of a pole of a lead storage battery.

  For example, a lead storage battery used for an automobile or the like includes an electrode group, a battery case containing an electrolytic solution, a lid member for sealing the battery container, and a terminal portion. The terminal portion is composed of a lead alloy bushing integrated with the lid member by insert molding, and a pole that is inserted into the bushing (see Patent Document 1 below).

  By the way, the electrolytic solution filled in the battery case has a height of the liquid surface, usually near the upper end of the connection body, so that the whole electrode plate group including the connection body is immersed below the liquid surface. (See FIG. 2 of Patent Document 2 below). Therefore, of the pole columns, the upper side of the connection body is exposed from the electrolytic solution.

JP2012-94372A

JP, 2010-267507, A

Since the liquid surface of the electrolyte is wavy due to vibration, etc., if a part of the pole column is exposed in the battery case as described above, the electrolyte scattered by the vibration may adhere to the surface of the pole column. .. When the state in which the surface is in contact with the electrolytic solution and the state in which it is in contact with the air are alternately repeated, the poles tend to be corroded, so that countermeasures have been required.
The present invention has been completed based on the above circumstances, and an object thereof is to suppress corrosion of a pole.

  The lead acid battery of the present invention disclosed by the present specification includes a power generation element, a battery case that houses the power generation element, an electrolyte solution that is housed in the battery case, and a lid member that seals the battery case. A cylindrical bushing embedded in the lid member, and a pole column that is connected to the power generating element and is located inside the bushing, and the liquid level of the electrolytic solution in the battery case is Make it higher than the bottom surface.

  Whether or not the level of the electrolyte is higher than the bottom surface of the bushing is determined by the bottom wall down and the battery case on a horizontal surface (that is, the battery container is not tilted). In, it shall be judged. That is, when the liquid level of the electrolytic solution is higher than the lower surface of the bushing in a state where the battery case is placed on a horizontal surface with the bottom wall facing downward, the lead storage battery of the present invention is considered.

  Further, the liquid level of the electrolytic solution does not have to be constantly maintained at a height higher than the lower surface of the bushing, and may be higher than the lower surface of the bushing even at a time. For example, if the liquid level of the electrolytic solution is higher than the lower surface of the bushing in the initial state after shipment from the manufacturer or after replenishing water, even if the liquid level of the electrolytic solution falls below the lower surface of the bushing due to subsequent use, the It corresponds to the lead acid battery of the invention.

  According to the lead-acid battery of the present invention disclosed in the present specification, the pole column is less likely to come into contact with air because it is immersed in the electrolytic solution. Therefore, the corrosion of the poles can be suppressed.

1 is a perspective view of a lead storage battery according to an embodiment of the present invention. Top view of battery case Vertical sectional view of lead-acid battery (sectional view taken along the line AA in FIG. 1) Top view of inner lid Top view of the lid Bottom view of the top lid FIG. 4 is an enlarged view of a part of FIG. 4 (showing a gas exhaust passage) FIG. 4 is an enlarged view of a part of FIG. 4 (showing the electrolyte circulation path). Vertical sectional view of a lead-acid battery according to another embodiment of the present invention

(Outline of this embodiment)
First, the outline of the lead storage battery of the present embodiment will be described. The present lead acid battery includes a power generation element, a battery case that houses the power generation element, an electrolyte solution that is housed in the battery case, a lid member that seals the battery case, and a tubular shape embedded in the lid member. And a pole that is connected to the power generating element and is located inside the bushing, and the liquid level of the electrolytic solution in the battery case is higher than the lower surface of the bushing. In this configuration, the pole pillar projecting downward from the lower surface of the bushing is immersed in the electrolytic solution, so that the pole pillar is less likely to come into contact with air. Therefore, the corrosion of the poles can be suppressed.

  In the lead acid battery of the present invention, the lid member includes an inner lid that seals the battery case, and an upper lid that is mounted so as to overlap the upper surface of the inner lid. An exhaust passage is formed to exhaust the gas generated in the tank to the outside, and the inner lid is provided with a return hole for returning the electrolytic solution in the exhaust passage into the battery case.

  In order to immerse the poles in the electrolytic solution, it is necessary to raise the liquid level of the electrolytic solution higher than usual. When the liquid level is raised, the distance to the gas exhaust hole becomes shorter, so that part of the electrolytic solution in the battery case scatters due to vibration such as running and easily escapes from the gas exhaust hole to the outside. In this respect, in this configuration, an exhaust passage is provided between the inner lid and the upper lid, and further, the electrolytic solution in the exhaust passage is returned to the battery case through the reflux hole. Therefore, for example, even if a part of the electrolytic solution in the battery case is scattered by vibration such as traveling and enters the gas exhaust hole, the electrolytic solution is returned to the battery case through the exhaust passage and the return hole. .. Therefore, the escape of the electrolytic solution can be suppressed.

  In the present lead acid battery, the upper surface of the upper lid is located above the upper surface of the bushing, the inner lid has a protruding portion protruding upward, and the exhaust passage is formed in the protruding portion. Has been formed. In this configuration, since the upper lid is provided to a position higher than the bushing, even if a metal member or the like is placed on the upper portion of the battery, it is difficult to contact the bushing and it is possible to prevent conduction. it can. Then, the protrusion is arranged in the upper space formed by providing the upper lid to a position higher than the bushing, and the exhaust passage is formed in the protrusion. Accordingly, the exhaust passage can be formed at a position separated upward from the battery case, and the escape of the electrolytic solution can be further suppressed.

  In the present lead acid battery, a power generation element, a battery case having an outer wall for housing the power generation element, an electrolytic solution housed in the battery case, a lid member for sealing the battery case, and embedded in the lid member. A cylindrical bushing that is connected to the power generating element, and a pole that is located inside the bushing and that is located at a position above the lower surface of the bushing in the height direction of the outer wall of the battery case. , The maximum liquid level line that indicates the maximum liquid level position of the electrolytic solution is provided. When the maximum liquid level line is above the lower surface of the bushing, the liquid level of the electrolytic solution is higher than the lower surface of the bushing when the electrolytic solution reaches the maximum liquid level position. Therefore, it becomes difficult for the poles to come into contact with air, and corrosion of the poles can be suppressed.

  In the present lead acid battery, a power generation element, a battery case that houses the power generation element, an electrolyte solution that is housed in the battery case, a lid member that seals the battery case, and a tubular shape embedded in the lid member. Of the bushing and a pole that is connected to the power generating element and is located inside the bushing, and the lid member includes an injection hole for injecting an electrolytic solution into the battery case, and the injection hole. And a sleeve that is provided around the sleeve and extends toward the battery case, and the lower end position of the sleeve is higher than or equal to the lower surface of the bushing in the height direction. The sleeve is provided for visually recognizing whether the liquid level of the electrolytic solution reaches the maximum liquid level position, and the lower end position corresponds to the maximum liquid level position of the electrolytic solution. Therefore, when the lower end position of the sleeve is above the lower surface of the bushing, in the battery, the liquid level of the electrolytic solution is higher than the lower surface of the bushing when the electrolytic solution reaches the maximum liquid level position. Therefore, it becomes difficult for the poles to come into contact with air, and corrosion of the poles can be suppressed.

<Embodiment>
The first embodiment will be described with reference to FIGS.
1. Structure of Lead Acid Battery 10 As shown in FIGS. 1 to 3, the lead acid battery 10 includes a battery case 20, an electrode plate group 30 which is a power generating element, an electrolytic solution U, and a lid member 50. In the following description, the lateral direction of the battery case 20 (the direction in which the terminals 40A and 40B are arranged) is the X direction, the height direction of the battery case 20 is the Y direction, and the depth direction is the Z direction.

  The battery case 20 is made of synthetic resin. The battery case 20 includes four outer walls 21 and a bottom wall 22, and has a box shape with an open top surface. The inside of the battery case 20 is divided into a plurality of cell chambers 25 by partition walls 23 as shown in FIG. Six cell chambers 25 are provided in the widthwise direction of the battery case 20 (X direction in FIG. 2 ), and the electrode plate group 30 is accommodated in each cell chamber 25 together with the electrolytic solution U made of dilute sulfuric acid. ..

  As shown in FIG. 3, the electrode plate group 30 includes a positive electrode plate 30A, a negative electrode plate 30B, and a separator 30C that partitions the both electrode plates 30A and 30B. Each of the electrode plates 30A and 30B is formed by filling a lattice body with an active material, and ear portions 31A and 31B are provided on the upper portions thereof. The ears 31A and 31B are provided to connect the polar plates 30A and 30B of the same polarity in the cell chamber 25 via the strap 32.

  The strap 32 has, for example, a plate shape that is long in the X direction, and two sets for the positive electrode and the negative electrode are provided for each cell chamber 25. Then, the positive and negative straps 32 of the adjacent cell chambers 25 are electrically connected to each other via the connection portion 33 formed on the strap 32, so that the electrode plate groups 30 of the cell chambers 25 are connected in series. It has a structure.

  The lid member 50 includes an inner lid 60 and an upper lid 100. The inner lid 60 is made of synthetic resin and has a size capable of sealing the upper surface of the battery case 20. A lid partition wall (not shown) is formed on the back surface of the inner lid 60 so as to correspond to the partition wall 23. The inner lid 60 is attached so as to overlap the battery case 20, seals the upper surface of the battery case 20, and hermetically seals the cell chambers 25 in the battery case 20. Similar to the inner lid 60, the upper lid 100 is made of synthetic resin, and is attached to the trapezoidal portion 65 formed so as to project from the upper surface of the inner lid 60 in an overlapping manner. The upper surface 100A of the upper lid 100 is located above the upper surface of the bushing 41, as shown in FIG. The trapezoidal portion 65 is an example of the “projecting portion” in the present invention.

  Between the trapezoidal portion 65 of the inner lid 60 and the upper lid 100, an exhaust passage R for exhausting gas generated in the cell chamber 25 to the outside, an electrolytic solution U in the exhaust passage R, and steam are provided in each cell chamber 25. A reflux hole 95 for refluxing is provided, and these structures will be described in detail later.

  The inner lid 60 is heat-welded to the battery case 20. The upper lid 100 is heat-welded to the inner lid 60.

  Further, the lead storage battery 10 is provided with a positive electrode side terminal portion 40A and a negative electrode side terminal portion 40B. As shown in FIG. 1, the terminal portion 40A on the positive electrode side and the terminal portion 40B on the negative electrode side are arranged on both sides of the inner lid 60 in the X direction. Since the positive electrode side terminal portion 40A and the negative electrode side terminal portion 40B have the same structure, the structure will be described below taking the positive electrode side terminal portion 40A as an example.

  As shown in FIG. 3, the terminal portion 40A on the positive electrode side includes a bushing 41 and a pole 45. The bushing 41 is made of metal such as lead alloy and has a hollow cylindrical shape. As shown in FIG. 3, the bushing 41 penetrates a cylindrical mounting portion 63 integrally formed with the inner lid 60, and an upper half thereof projects from the upper surface of the inner lid 60. An upper half portion of the bushing 41 exposed from the upper surface of the inner lid 60 is a terminal connecting portion, and a connecting terminal (not shown) such as a harness terminal is assembled.

  Since the inner lid 60 is integrally molded by pouring resin into a mold into which the bushing 41 is inserted, the mounting portion 63 is integrated with the bushing 41 and has a structure that covers the lower outer periphery of the bushing 41 without a gap. That is, the bushing 41 has a structure in which the other portion except the upper half portion projecting from the upper surface of the inner lid 60 is embedded in the mounting portion 63 of the inner lid 60. A bottom wall 64 that surrounds the lower surface of the bushing 41 is formed in the mounting portion 63.

  The pole 45 is made of metal such as lead alloy and has a columnar shape. The pole 45 is inserted into the bushing 41 from below. The pole 45 is longer than the bushing 41, the upper part of the pole 45 is located inside the bushing 41, and the lower part projects downward from the lower surface 41A of the bushing 41. The upper end 46 of the pole 45 is joined to the bushing 41 by welding, and the base 47 of the pole 45 is joined to the strap 32 of the pole group 30.

2. Liquid Level of Electrolyte U In the lead storage battery 10 of the present embodiment, as shown in FIG. 3, the liquid level L of the electrolyte U filled in each cell chamber 25 of the battery case 20 is set to the lower surface of the bushing 41. Set the same height as 41A. Specifically, as shown in FIG. 3, the battery case 20 is placed on a horizontal surface with the bottom wall 22 facing downward so that the liquid level L is the same as the lower surface 41A of the bushing 41. The amount of the electrolytic solution U with respect to 20 is set. When the liquid level L of the electrolytic solution U is set to the same height as the lower surface 41A of the bushing 41, the pole columns 45 protruding downward from the lower surface 41A of the bushing 41 are immersed in the electrolytic solution U. If the electrode 45 is immersed in the electrolytic solution U, the surface of the pole 45 does not come into contact with air in the battery case 20, so that the pole 45 can be prevented from corroding.

  When the liquid level L of the electrolytic solution U is set to the same height as the lower surface 41A of the bushing 41, the lower portion of the mounting portion 63 that covers the outside of the bushing 41 is submerged in the electrolytic solution U. There is concern that the electrolytic solution U may creep up through the gap. However, the rising of the electrolytic solution U is equivalent to that when the liquid level L of the electrolytic solution U is lower than the lower surface 41A of the bushing 41, and the lower portion of the mounting portion 63 that covers the outside of the bushing 41 is electrolyzed. Whether or not it is submerged in the liquid U does not affect the ease with which the electrolytic solution U climbs up.

3. Structure for Preventing Gas Exhaust and Escape of Electrolyte U FIG. 4 is a plan view of the inner lid 60 seen from above. A trapezoidal portion 65 is provided on the back side in the Z direction (upper side in FIG. 4) of the upper surface of the inner lid 60. The trapezoidal portion 65 is one step higher than the base portion (the portion where the terminal portion 40A and the terminal portion 40B are formed) 61 of the inner lid 60, and crosses the six cell chambers 25 provided in the battery case 20. In the X direction.

  As shown in FIG. 4, on the upper surface 65A of the trapezoidal portion 65, six liquid injection chambers 71 and six exhaust chambers 81 are formed in the X direction corresponding to the six cell chambers 25. More specifically, a peripheral wall 72 is formed on the upper surface 65A of the trapezoidal portion 65 so as to surround the six liquid injection chambers 71. Five partition walls 73 are formed in the X direction inside the peripheral wall 72, and divide the region inside the peripheral wall 72 into six liquid injection chambers 71. Then, a liquid injection hole 75 communicating with each cell chamber 25 is formed in each liquid injection chamber 71, and a replenisher can be injected into each cell chamber 25 through the liquid injection hole 75.

  On the other hand, each exhaust chamber 81 is formed in front of each liquid injection chamber 71 (lower side in FIG. 4). Similar to the liquid injection chamber 71, the exhaust chamber 81 is also formed with a peripheral wall 82 so as to surround the six exhaust chambers 81, and the inner region of the peripheral wall is formed by five partition walls 83 formed in the X direction to form six exhaust chambers. The structure is divided into chambers 81.

  Further, each exhaust chamber 81 is formed with two partition plates 85 and 86 and a small chamber 91 partitioned by a peripheral wall 92. The two partition plates 85 and 86 are formed alternately from the left and right partition walls 83 facing each other in the X direction toward the inside of the exhaust chamber 81.

  The small chamber 91 is formed in front of the partition plates 85 and 86 (lower side in FIG. 4), and the inside is partitioned into two chambers by a partition wall 93. A gas discharge hole 94 is formed on one side of the partitioned small chamber 91, and a return hole 95 is provided on the other side. The gas discharge hole 94 and the recirculation hole 95 penetrate the inner lid 60 in the vertical direction, and are configured to communicate with the respective cell chambers 25 in the battery case 20. A cutout 92A is formed in the peripheral wall 92, and the small chamber 91 is structured to communicate with the exhaust chamber 81 through the cutout 92A.

  Further, concentrated exhaust portions 97 are formed in the exhaust chambers 81 located at both ends in the X direction. The concentrated exhaust part 97 includes an arc-shaped peripheral wall 98, and communicates with the exhaust chamber 81 located at the end in the X direction through the notch 98A.

  On the other hand, as shown in FIGS. 1 and 5, the upper lid 100 extends in the X direction so as to traverse the six cell chambers 25 provided in the battery case 20, like the shape of the trapezoidal portion 65 of the inner lid 60. It is set up. An outer peripheral wall 110 is formed on the outer edge of the upper lid 100. The outer peripheral wall 110 extends downward and is formed over the entire circumference of the upper lid 100.

  As shown in FIG. 6, on the back surface of the upper lid 100, the peripheral walls 172 and 182 having the same shape and the partition walls 173 corresponding to the peripheral walls 72 and 82 and the partition walls 73 and 83 provided in the trapezoidal portion 65, respectively. , 183 are formed. Therefore, by mounting the upper lid 100, it is possible to seal the liquid injection chambers 71 formed on the platform 65 and the upper surfaces of the exhaust chambers 81. Further, on the back surface of the upper lid 100, two partition plates 185, 186 are formed corresponding to the two partition plates 85, 86, and a peripheral wall 198 is formed corresponding to the peripheral wall 98 forming the concentrated exhaust part 97. There is. Further, a partition wall 193 is formed corresponding to the partition wall 93 that partitions the small chamber 91. A notch 193A is formed in the partition wall 193, so that the gas and the electrolytic solution can flow in the small chamber 91.

  As shown in FIG. 7, each exhaust chamber 81 constitutes a labyrinth-shaped exhaust passage R, and the gas that has entered the small chamber 91 from the gas exhaust hole 94 advances through the exhaust passage R of the exhaust chamber 81 to inject liquid. The structure reaches the boundary with the chamber 71.

  As shown in FIG. 6, slits 183A are formed in each partition wall 183 formed on the upper lid 100, and the exhaust chambers 81 communicate with each other through the slits 183A at the boundary with the liquid injection chamber 71. To do. From the above, after the gas in each exhaust chamber 81 reaches the boundary with the liquid injection chamber 71 via the exhaust passage R formed in the upper surface 65A of the trapezoidal portion 65 as shown in FIG. It is sent to the concentrated exhaust portions 97 located on both sides in the X direction through the slit 183A.

  Further, a tunnel-shaped discharge duct 200 that opens to the outer peripheral wall 110 is formed on the upper lid 100. As shown in FIG. 6, the exhaust duct 200 communicates with the peripheral wall 198 of the central exhaust part 97, and the gas sent to the central exhaust part 97 is discharged from the outer wall 110 of the upper wall 100 to the outside through the exhaust duct 200. It is structured to be exhausted. Note that, as described above, "the exhaust passage R is formed in the projecting portion (in this example, the upper surface 65A of the trapezoidal portion 65)" of the present invention is realized.

  Further, the floor surface of each exhaust chamber 81 is inclined so that it becomes lower as it approaches the return hole 95. Therefore, the electrolytic solution U and water vapor contained in the gas can be returned to each cell chamber 25 through the return hole 95. That is, the electrolytic solution U and water vapor contained in the gas generated in the cell chamber 25 are condensed in the exhaust passage R when the gas passes through the exhaust passage R. After that, the condensed electrolytic solution U and water vapor flow toward the reflux hole 95 as shown by the broken line arrow in FIG. Therefore, the electrolytic solution U and water vapor contained in the gas can be recirculated to each cell chamber 25.

4. Description of Effect In the present lead acid battery 10, since it is immersed in the electrolytic solution U, it is difficult for the poles 45 to come into contact with air. Therefore, the corrosion of the poles 45 can be suppressed. Further, in order to immerse the pole 45 in the electrolytic solution U, it is necessary to raise the liquid level L of the electrolytic solution U higher than usual. The normal state means a state in which the liquid level of the electrolytic solution U is aligned with the upper end of the connecting portion 33, as indicated by the line “Lo” in FIG.

  When the liquid level L is raised, the distance to the gas exhaust hole 94 becomes shorter, so that part of the electrolytic solution U in the cell chamber 25 scatters due to vibrations such as running and escapes from the gas exhaust hole 94 to the outside. It becomes easy to put out. In this respect, the lead-acid battery 10 has a structure in which the exhaust passage R is provided between the inner lid 60 and the upper lid 100, and the electrolytic solution U in the exhaust passage R is returned to the cell chamber 25 through the reflux hole 95. Therefore, for example, even if a part of the electrolytic solution U is scattered by vibration such as traveling and enters the gas exhaust hole 94, the electrolytic solution U is recirculated to the cell chamber 25 from the recirculation hole 95. Therefore, the escape of the electrolytic solution U can be suppressed.

  Further, since the upper lid 100 is provided to a position higher than the bushing 41, even if a metal member or the like is placed on the upper portion of the battery, it is difficult to contact the bushing 41 and to prevent conduction. You can Then, the trapezoidal portion 65 is arranged in the upper space formed by providing the upper lid 100 to a position higher than the bushing 41, and the exhaust passage R is formed in the trapezoidal portion 65. As a result, the exhaust passage R can be formed at a position separated upward from the battery case 20, and the escape of the electrolytic solution can be further suppressed.

  Further, the lead storage battery 10 is required to keep the liquid surface of the electrolytic solution U high in order to immerse the poles 45 therein. Must be filled with U. However, if the liquid level L of the electrolytic solution U is high, it is possible to set the sizes (dimensions in the Y direction) of the electrode plates 30A and 30B larger accordingly. Therefore, the lead-acid battery 10 can have higher battery performance than an ordinary battery in which the poles 45 are partially exposed.

<Other Embodiments>
The present invention is not limited to the embodiments described by the above description and drawings, and the following embodiments are also included in the technical scope of the present invention.

  (1) In the above-described embodiment, the liquid level L of the electrolytic solution U is set to the same height as the lower surface 41A of the bushing 41. However, when the pole 45 in the battery case 20 is immersed in the electrolytic solution U, Of course, the liquid level L of the electrolytic solution U may be set higher than the lower surface 41A of the bushing 41.

  (2) Further, the liquid level L of the electrolytic solution U does not need to always maintain a height equal to or higher than the lower surface 41A of the bushing 41, and may be equal to or higher than the lower surface 41A of the bushing 41 even at a time. For example, when the liquid level L of the electrolytic solution U is higher than the lower surface 41A of the bushing 41 in the initial state at the time of shipment from the manufacturer or after replenishing water, the liquid level L of the electrolytic solution U becomes the lower surface of the bushing 41 by subsequent use. Even if it is lower than 41A, it is included in the technical scope of the present invention. The reason is that if the liquid level L of the electrolytic solution U is higher than the lower surface 41A of the bushing 41 even during the initial state at the time of shipment from the manufacturer or after replenishing water, the pole 45 is hard to come into contact with air and corrosion of the pole 45 is prevented. This is because it is nothing but suppression.

  (3) Further, in the technical scope of the present invention, as shown in FIG. 9, the position of the maximum liquid level line ULV provided on the outer wall 421 of the battery case 420 is the bushing in the height direction (Y direction). A lead storage battery 410 having a lower surface 41A or more of 41 is also included. This is because the liquid amount of the electrolytic solution U is adjusted such that the liquid level L reaches the maximum liquid level line ULV by replenishing water at the time of manufacture by the manufacturer and during use. Therefore, when the maximum liquid level line ULV indicating the maximum liquid level position of the electrolytic solution U is equal to or higher than the lower surface 41A of the bushing 41, the lead storage battery battery 410 has a liquid level L of the electrolytic solution U higher than the lower surface 41A of the bushing 41. This is because, as a result of being used in a state, it becomes difficult for the pole 45 to come into contact with air, and corrosion of the pole 45 can be suppressed.

  Note that, in FIG. 9, the symbol “LLV” indicates the minimum liquid level line of the electrolytic solution U. Further, in FIG. 9, parts common to those of the lead storage battery 10 described in the above embodiment are designated by the same reference numerals. Further, in FIG. 9, the electrolytic solution U is omitted in order to clearly show the maximum liquid level line ULV and the minimum liquid level line LLV.

  (4) Further, for example, in the lead storage battery 410 in which the liquid injection hole 463 and the sleeve 465 are provided in the lid member 450, as shown in FIG. Direction), it is also included in the technical scope of the present invention when it is the lower surface 41A or more of the bushing 41. Specifically, as shown in FIG. 9, the sleeve 465 is provided around the liquid injection hole 463 and extends from the edge of the liquid injection hole 463 toward the battery case 420. The sleeve 465 is a cylindrical type having a slit 467 on the peripheral side surface, and is provided to visually recognize the height of the liquid surface L of the electrolytic solution U. That is, when the electrolytic solution U reaches the lower end of the sleeve 465, the electrode plates 30A and 30B in the electrolytic solution appear distorted. Therefore, by visually observing the electrode plates 30A and 30B through the sleeve 465, the electrolytic solution U It is possible to visually confirm whether the surface L reaches the lower end of the sleeve 465, that is, the maximum liquid surface position. The amount of the electrolytic solution U is adjusted so that the liquid level L reaches the lower end 465A of the sleeve 465 at the time of shipment from the manufacturer or by replenishing water. Therefore, when the position of the lower end 465A of the sleeve 465 is higher than or equal to the lower surface 41A of the bushing 41, the lead storage battery 410 is used with the liquid level L of the electrolytic solution U higher than the lower surface 41A of the bushing 41. This is because the poles 45 are less likely to come into contact with air, and corrosion of the poles 45 can be suppressed.

  Note that in the example of FIG. 9, the lid member 450 has a double structure of an inner lid 460 and an upper lid 470, and is provided on the inner lid 460 side for sealing the upper surface of the battery case 420 in correspondence with each cell chamber 25. A liquid hole 463 and a sleeve 465 are provided respectively. Further, the upper lid 470 is provided with respective liquid injection holes 473 corresponding to the respective liquid injection holes 463 on the inner lid 460 side, and the electrolytic solution U is filled with the liquid injection holes 473 of the upper lid 470 and the inner lid 469. Each cell chamber 25 in the battery case 420 is replenished through the liquid hole 463 and the sleeve 465.

  (5) In the above embodiment, the lid member 50 has a double lid structure of the inner lid 60 and the upper lid 100, and the gas exhaust passage R and the electrolytic solution U in the exhaust passage R are recirculated to the cell chamber 25 between them. Although the holes 95 are provided, the structure for refluxing the electrolytic solution U does not necessarily have to be provided. That is, the lid member may have a single lid structure, and the structure for refluxing the electrolytic solution U may be omitted.

  When the structure for refluxing the electrolytic solution U is abolished, water vapor and the electrolytic solution U easily mix with the gas generated in the battery case and are easily discharged to the outside. It tends to fluctuate. In such a case, the “minimum liquid level position that is the lower limit” of the electrolytic solution U may be set higher than the lower surface 41A of the bushing 41.

  Further, when the “minimum liquid level position that is the lower limit” of the electrolytic solution U is set higher than the lower surface 41A of the bushing 41, the distance to the lid member 50 becomes closer on the maximum liquid level position that is the upper limit, and the electrolytic solution U becomes It may easily escape to the outside. Therefore, in such a case, the "maximum liquid surface position that is the upper limit" of the electrolytic solution U is set to the same height as the lower surface 41A of the bushing 41 to ensure the distance from the liquid surface to the lid member 50. May be. If the "highest liquid level position corresponding to the upper limit" of the electrolytic solution U is set to the same height as the lower surface 41A of the bushing 41, when the liquid level is lowered, a part of the pole 45 will be exposed from the liquid level. The liquid surface of the electrolytic solution U is eventually returned to the “maximum liquid surface position corresponding to the upper limit” by replenishing the replenishing liquid. Therefore, the period in which a part of the pole 45 is exposed becomes shorter than that in the conventional case, so that the progress of corrosion of the pole 45 can be delayed.

10... Lead-acid battery 20... Battery case 30... Electrode group (an example of “power generation element” of the present invention)
41... Bushing 45... Pole pole 50... Lid member 60... Inner lid 65... Trapezoidal portion (an example of "protruding portion" of the present invention)
94... Gas exhaust hole 95... Reflux hole 100... Top lid R... Exhaust passage U... Electrolyte

Claims (6)

Power generation element,
A battery case containing the power generation element,
An electrolytic solution contained in the battery case,
A lid member for sealing the battery case,
A tubular bushing made of metal embedded in the lid member, and a terminal portion that is connected to the power generation element and includes a pole that is located inside the bushing,
The terminal portion includes only one terminal connecting portion to which a connecting terminal is assembled,
A lead acid battery in which the liquid level of the electrolytic solution in the battery case is higher than the lower surface of the bushing. Power generation element,
A battery case containing the power generation element,
An electrolytic solution contained in the battery case,
A lid member for sealing the battery case,
A tubular bushing embedded in the lid member, and a terminal portion connected to the power generation element and including a pole located inside the bushing,
The lid member includes a mounting portion that covers a lower outer periphery of the bushing,
The terminal portion includes only one terminal connecting portion to which a connecting terminal is assembled,
A lead acid battery in which the liquid level of the electrolytic solution in the battery case is higher than the lower surface of the bushing. The lead acid battery according to claim 1 or 2, wherein
The lid member is
An inner lid for sealing the battery case,
Including an upper lid that is mounted on the upper surface of the inner lid,
An exhaust passage for exhausting the gas generated in the battery case to the outside is formed between the inner lid and the upper lid,
The lead-acid battery in which the inner lid is provided with a recirculation hole for recirculating the electrolytic solution in the exhaust passage into the battery case. The lead acid battery according to claim 3,
The upper surface of the upper lid is located above the upper surface of the bushing,
The inner lid has a protruding portion protruding upward,
The lead-acid battery in which the exhaust passage is formed in the protrusion. The lead storage according to claim 1 or 2, wherein
The lid member is
An injection hole for injecting an electrolytic solution into the battery case,
A sleeve provided around the liquid injection hole and extending to the battery case side,
A lead storage battery in which the lower end position of the sleeve is higher than or equal to the lower surface of the bushing in the height direction. The lead acid battery according to any one of claims 1 to 5,
A lead acid battery that suppresses corrosion of the poles by immersing the poles protruding downward from the lower surface of the bushing in the electrolytic solution.

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