JP2019197736A - Lead acid battery - Google Patents

Abstract

To inhibit pole column corrosion.SOLUTION: The corrosion of a pole 45 that protrudes downward from the lower surface of a bushing 41 is suppressed by setting the level of an electrolyte U filled in a battery case 20 to be higher than the lower surface of the bushing 41 that penetrates a lid member 50 that seals the battery case 20, and immersing the pole 45 in the electrolyte U. In this method, since the pole 45 protruding downward from the lower surface of the bushing 41 is immersed in the electrolyte U, the pole 45 is difficult to touch the air. Therefore, corrosion of the pole 45 can be suppressed.SELECTED DRAWING: Figure 3

Description

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

  For example, a lead storage battery used for automobiles or the like includes an electrode plate group and a battery case that contains an electrolytic solution, a lid member that seals the battery case, 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 post inserted into the bushing (see Patent Document 1 below).

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

JP 2012-94372 A

JP 2010-267507 A

Since the liquid level of the electrolytic solution undulates due to vibration or the like, if a part of the polar column is exposed in the battery case as described above, the electrolytic solution scattered by the vibration may adhere to the surface of the polar column. . Countermeasures have been sought because the pole column tends to corrode when the surface is in contact with the electrolyte and the air is alternately repeated.
The present invention has been completed based on the above-described circumstances, and an object thereof is to suppress the corrosion of the pole column.

  The lead storage 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 electrolytic 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 connected to the power generation element and positioned inside the bushing, and the level of the electrolyte in the battery case Make the height higher than the lower surface.

  Whether or not “the level of the electrolyte is higher than the lower surface of the bushing” depends on whether the battery case is on a horizontal surface with the bottom wall down (ie, the battery case is not tilted). In this case, it shall be judged. That is, when the battery case is on the horizontal surface with the bottom wall facing down and the liquid level of the electrolytic solution is higher than the lower surface of the bushing, it corresponds to the lead storage battery of the present invention.

  Further, the liquid level of the electrolytic solution need not always maintain a height higher than the lower surface of the bushing, and may be higher than the lower surface of the bushing even at one time. For example, if the electrolyte level is higher than the bottom surface of the bushing in the initial state at the time of shipment from the manufacturer or after refilling, even if the electrolyte level drops below the bottom surface of the bushing after use, Corresponds to the lead-acid battery of the invention.

  According to the lead storage battery of the present invention disclosed by the present specification, since the electrode is immersed in the electrolytic solution, it becomes difficult for the pole column to touch the air. Therefore, corrosion of the pole can be suppressed.

The perspective view of the lead storage battery which concerns on one Embodiment of this invention. Top view of the battery case Vertical sectional view of lead-acid battery (cross-sectional view taken along line AA in FIG. 1) Top view of the inner lid Top view of the top lid Bottom view of top lid Fig. 4 is a partially enlarged view (showing the gas exhaust passage) Fig. 4 is an enlarged view of part of Fig. 4 (showing the electrolyte reflux path) Vertical sectional view of a lead storage battery according to another embodiment of the present invention.

(Outline of this embodiment)
First, an outline of the lead storage battery of the present embodiment will be described. The lead storage battery includes a power generation element, a battery case that houses the power generation element, an electrolytic solution that is accommodated in the battery case, a lid member that seals the battery case, and a cylindrical shape embedded in the lid member. And a pole column connected to the power generation element and positioned inside the bushing, and the liquid level of the electrolyte in the battery case is made higher than the lower surface of the bushing. In this configuration, since the pole column protruding downward from the lower surface of the bushing is immersed in the electrolyte, the pole column is difficult to touch the air. Therefore, corrosion of the pole can be suppressed.

  In the lead storage battery, the lid member includes an inner lid that seals the battery case, and an upper lid that is mounted on the upper surface of the inner lid, and the electric battery is interposed between the inner lid and the upper lid. An exhaust passage for exhausting the gas generated in the tank to the outside is formed, and the inner lid is provided with a reflux hole for returning the electrolytic solution in the exhaust passage into the electric tank.

  In order to immerse the pole column in the electrolyte, it is necessary to raise the level of the electrolyte more than usual. When the liquid level is raised, the distance to the gas exhaust hole is reduced, so that a part of the electrolytic solution in the battery case is scattered due to vibrations such as traveling and easily escapes from the gas exhaust hole to the outside. In this regard, in this configuration, an exhaust passage is provided between the inner lid and the upper lid, and 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 due to vibration during traveling or the like and enters the gas exhaust hole, the electrolytic solution returns to the battery case through the exhaust passage and the return hole. . Therefore, escape of the electrolytic solution can be suppressed.

  In the present lead storage 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 connected to the protruding portion. Is formed. In this configuration, the upper lid is provided to a position higher than the bushing, so that even if a metal member or the like is placed on the upper part of the battery, it is difficult to contact the bushing and prevent conduction. it can. And a protrusion part is arrange | positioned in the upper space formed by providing an upper cover to a position higher than a bushing, and an exhaust passage is formed in this protrusion part. Thereby, an exhaust passage can be formed in the position away from the battery case upward, and escape of electrolyte solution can be controlled more.

  In this lead storage battery, a power generation element, a battery case having an outer wall and containing the power generation element, an electrolyte solution accommodated 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 generation element and located on the inside of the bushing, and the outer wall of the battery case is at a position that is higher than the lower surface of the bushing in the height direction. The highest liquid level line indicating the highest liquid level position of the electrolytic solution is provided. When the highest liquid level line is equal to or higher than the lower surface of the bushing, the liquid surface of the electrolytic solution is higher than the lower surface of the bushing when the electrolytic solution reaches the highest liquid surface position. Therefore, it becomes difficult for the pole column to come into contact with air, and corrosion of the pole column can be suppressed.

  In this lead storage battery, a power generation element, a battery case that houses the power generation element, an electrolytic solution that is housed in the battery case, a lid member that seals the battery case, and a cylindrical shape embedded in the lid member And a pole column connected to the power generation element and positioned inside the bushing, the lid member injecting electrolyte into the battery case, and the injection hole , And a lower end position of the sleeve is equal to or higher than the lower surface of the bushing in the height direction. The sleeve is provided for visually confirming whether the liquid level of the electrolytic solution has reached the highest liquid level position, and the lower end position corresponds to the highest liquid level position of the electrolytic solution. Therefore, when the lower end position of the sleeve is equal to or higher than the lower surface of the bushing, the battery has a higher electrolyte level than the lower surface of the bushing when the electrolytic solution reaches the highest liquid level position. Therefore, it becomes difficult for the pole column to come into contact with air, and corrosion of the pole column can be suppressed.

<Embodiment>
The first embodiment will be described with reference to FIGS.
1. Structure of the lead storage battery 10 The lead storage battery 10 includes a battery case 20, an electrode plate group 30, which is a power generation element, an electrolytic solution U, and a lid member 50, as shown in FIGS. In the following description, the horizontal width direction (the arrangement direction of the terminal portions 40A and 40B) of the battery case 20 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 upper surface. The interior of the battery case 20 is partitioned into a plurality of cell chambers 25 by partition walls 23 as shown in FIG. Six cell chambers 25 are provided in the lateral width direction (X direction in FIG. 2) of the battery case 20, and each cell chamber 25 accommodates an electrode plate group 30 together with an electrolyte 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 electrode plates 30A and 30B. Each of the electrode plates 30A and 30B is configured by filling a lattice body with an active material, and ears 31A and 31B are provided in the upper part. The ears 31 </ b> A and 31 </ b> B are provided to connect the electrode plates 30 </ b> A and 30 </ b> B having the same polarity through the strap 32 in the cell chamber 25.

  The strap 32 has, for example, a plate shape that is long in the X direction, and two sets for a positive electrode and a 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 a connection portion 33 formed on the strap 32 to connect the electrode plate groups 30 of the cell chambers 25 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 corresponding to the partition wall 23. The inner lid 60 is attached so as to overlap the battery case 20, and has a structure that seals the upper surface of the battery case 20 and hermetically seals each cell chamber 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 base portion 65 formed so as to protrude from the upper surface of the inner lid 60. The upper surface 100A of the upper lid 100 is located above the upper surface of the bushing 41 as shown in FIG. The platform 65 is an example of the “projection” in the present invention.

  Between the trapezoidal portion 65 of the inner lid 60 and the upper lid 100, the exhaust passage R that exhausts the gas generated in the cell chamber 25 to the outside, and the electrolyte U and water vapor in the exhaust passage R are supplied to 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 thermally welded to the battery case 20. Further, the upper lid 100 is thermally welded to the inner lid 60.

  In addition, the lead storage battery 10 is provided with a positive terminal portion 40A and a negative terminal portion 40B. As shown in FIG. 1, the positive terminal portion 40 </ b> A and the negative terminal portion 40 </ b> B are disposed on both sides of the inner lid 60 in the X direction. Since the structure of the positive terminal portion 40A and the negative terminal portion 40B is the same, the structure will be described below taking the positive terminal portion 40A as an example.

  As shown in FIG. 3, the positive terminal portion 40 </ b> A includes a bushing 41 and a pole column 45. The bushing 41 is made of a metal such as a lead alloy and has a hollow cylindrical shape. As shown in FIG. 3, the bushing 41 passes through a cylindrical mounting portion 63 formed integrally with the inner lid 60, and the upper half protrudes from the upper surface of the inner lid 60. In the bushing 41, the upper half exposed from the upper surface of the inner lid 60 is a terminal connection portion, and a connection terminal (not shown) such as a harness terminal is assembled.

  In addition, since the inner lid 60 is integrally formed by pouring resin into a mold in which the bushing 41 is inserted, the mounting portion 63 is integrated with the bushing 41 so that the lower outer periphery of the bushing 41 is covered without a gap. That is, the bushing 41 has a structure in which the other part except the upper half protruding from the upper surface of the inner lid 60 is embedded in the mounting portion 63 of the inner lid 60. Further, a bottom wall 64 that surrounds the lower surface of the bushing 41 is formed in the mounting portion 63.

  The pole column 45 is made of a metal such as a lead alloy and has a cylindrical shape. The pole 45 is inserted into the bushing 41 from below. The pole column 45 is longer than the bushing 41, the upper portion of the pole column 45 is located inside the bushing 41, and the lower portion projects downward from the lower surface 41 </ b> A of the bushing 41. An upper end portion 46 of the pole column 45 is joined to the bushing 41 by welding, and a base end portion 47 of the pole column 45 is joined to the strap 32 of the electrode plate group 30.

2. Liquid Level Height of Electrolytic Solution U In the lead storage battery 10 of the present embodiment, as shown in FIG. 3, the liquid level L of the electrolytic solution U filled in each cell chamber 25 of the battery case 20 is changed to the lower surface of the bushing 41. Set to the same height as 41A. Specifically, as shown in FIG. 3, the battery case so that the liquid level L is the same height as the lower surface 41 </ b> A of the bushing 41 in the use state in which the battery case 20 is on a horizontal surface with the bottom wall 22 facing down. The amount of the electrolytic solution U with respect to 20 is set. When the liquid surface L of the electrolytic solution U is made to be the same height as the lower surface 41A of the bushing 41, the pole column 45 protruding downward from the lower surface 41A of the bushing 41 is immersed in the electrolytic solution U. If immersed in the electrolytic solution U, the surface of the pole column 45 does not come into contact with air in the battery case 20, so that the pole column 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 part of the mounting part 63 that covers the outside of the bushing 41 is immersed in the electrolytic solution U. Therefore, the bushing 41 and the mounting part 63 There is a concern that the electrolyte U creeps through the gap. However, the creeping up of the electrolytic solution U is equivalent to the case where 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 immersed in the liquid U does not affect the ease with which the electrolytic solution U can be rolled up.

3. FIG. 4 is a plan view of the inner lid 60 as viewed from above. A table-like portion 65 is provided on the upper side of the inner lid 60 on the back side in the Z direction (upper side in FIG. 4). The trapezoidal portion 65 is one step higher than the base 61 (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. Extending in the X direction.

  As shown in FIG. 4, six liquid injection chambers 71 and six exhaust chambers 81 are formed in the X direction corresponding to the six cell chambers 25 on the upper surface 65 </ b> A of the platform 65. More specifically, a peripheral wall 72 is formed on the upper surface 65 </ b> A of the platform 65 so as to surround the six liquid injection chambers 71. Inside the peripheral wall 72, five partition walls 73 are formed in the X direction, and the region inside the peripheral wall 72 is partitioned into six liquid injection chambers 71. Each liquid injection chamber 71 is formed with a liquid injection hole 75 communicating with each cell chamber 25, and the 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). Similarly to the liquid injection chamber 71, the exhaust chamber 81 is formed with a peripheral wall 82 so as to surround the six exhaust chambers 81, and the inner region of the peripheral wall is divided into six exhausts by five partition walls 83 formed in the X direction. The chamber 81 is partitioned.

  Each exhaust chamber 81 is formed with a small chamber 91 partitioned by two partition plates 85 and 86 and a peripheral wall 92. The two partition plates 85 and 86 are formed alternately from the left and right partition walls 83 facing 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 reflux hole 95 is provided on the other side. The gas discharge hole 94 and the reflux hole 95 pass through the inner lid 60 in the vertical direction, and are configured to communicate with each cell chamber 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.

  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 cross the six cell chambers 25 provided in the battery case 20, similarly to the shape of the base portion 65 of the inner lid 60. It is installed. 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 periphery of the upper lid 100.

  On the back surface of the upper lid 100, as shown in FIG. 6, the peripheral walls 172 and 182 having the same shape and the respective partition walls 173 corresponding to the respective peripheral walls 72 and 82 and the respective partition walls 73 and 83 provided on the platform 65. , 183 are formed. Therefore, by mounting the upper lid 100, the top surfaces of the liquid injection chambers 71 and the exhaust chambers 81 formed on the platform 65 can be sealed. In addition, two partition plates 185 and 186 corresponding to the two partition plates 85 and 86 are formed on the rear surface of the upper lid 100, and a peripheral wall 198 is formed corresponding to the peripheral wall 98 forming the concentrated exhaust portion 97. Yes. Furthermore, a partition wall 193 is formed corresponding to the partition wall 93 that partitions the small chamber 91. The partition wall 193 is formed with a notch 193 </ b> A so that a gas or an electrolyte can flow in the small chamber 91.

  As shown in FIG. 7, each exhaust chamber 81 constitutes a maze-like exhaust passage R, and the gas that has entered the small chamber 91 from the gas exhaust hole 94 proceeds 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 in 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 portion with the liquid injection chamber 71 via the exhaust passage R formed in the upper surface 65A of the base portion 65 as shown in FIG. It is sent to the concentrated exhaust part 97 located on both sides in the X direction through the slit 183A.

  Further, the upper lid 100 is formed with a tunnel-shaped discharge duct 200 that opens to the outer peripheral wall 110. As shown in FIG. 6, the exhaust duct 200 communicates with the peripheral wall 198 of the concentrated exhaust part 97, and the gas sent to the concentrated exhaust part 97 passes from the outer surface wall 110 of the upper wall 100 to the outside through the exhaust duct 200. It is structured to be exhausted. Note that, according to the present invention, “the exhaust passage R is formed in the protruding portion (in this example, the upper surface 65A of the base portion 65)” is realized.

  Further, the floor surface of each exhaust chamber 81 is inclined so as to become lower as it is closer to the reflux hole 95. Therefore, the electrolytic solution U and water vapor contained in the gas can be refluxed to each cell chamber 25 through the reflux 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. Thereafter, the condensed electrolyte U and water vapor flow toward the reflux hole 95 as shown by the broken line arrows in FIG. Therefore, the electrolytic solution U and water vapor contained in the gas can be refluxed to each cell chamber 25.

4). Description of Effect In the lead storage battery 10, since the electrode column 45 is immersed in the electrolytic solution U, the pole column 45 is difficult to touch the air. Therefore, corrosion of the pole column 45 can be suppressed. Further, in order to immerse the pole column 45 in the electrolytic solution U, it is necessary to raise the liquid level L of the electrolytic solution U more than usual. In addition, normal means the state which match | combined the liquid level of the electrolyte solution U with the upper end of the connection part 33, as shown by line "Lo" in FIG.

  When the liquid level L is raised, the distance to the gas exhaust hole 94 becomes closer, and therefore, a part of the electrolyte U in the cell chamber 25 is scattered by vibrations such as running, and is dissipated from the gas exhaust hole 94 to the outside. It becomes easy to take out. In this regard, the lead storage battery 10 has a structure in which an exhaust passage R is provided between the inner lid 60 and the upper lid 100 and the electrolyte 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 refluxed from the reflux hole 95 to the cell chamber 25. Therefore, escape of the electrolyte 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 part of the battery, it is difficult to contact the bushing 41 and prevent conduction. Can do. Then, the base portion 65 is disposed 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 base portion 65. Thereby, the exhaust passage R can be formed at a position away from the battery case 20 upward, and the escape of the electrolyte can be further suppressed.

  In addition, since the lead storage battery 10 immerses the pole column 45, it is necessary to keep the liquid level of the electrolyte U high. Compared to a normal battery in which the pole column 45 is partially exposed, the battery case 20 has more electrolyte solution. U needs to be filled. However, if the liquid level L of the electrolytic solution U is high, the size of the electrode plates 30A and 30B (dimension in the Y direction) can be set larger. Therefore, the lead storage battery 10 can improve battery performance as compared with a normal battery in which the pole column 45 is partially exposed.

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

  (1) In the said embodiment, although the liquid level L of the electrolyte solution U was set to the same height as 41 A of lower surfaces of the bushing 41, if the pole column 45 in the battery case 20 will be in the state immersed in the electrolyte solution U. 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 always need to maintain a height equal to or higher than the lower surface 41A of the bushing 41, and may be higher than the lower surface 41A of the bushing 41 even at one 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 in the state after refilling, the liquid level L of the electrolytic solution U is lowered from the lower surface of the bushing 41 by subsequent use. Even if it falls below 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 at one time such as the initial state at the time of shipment from the manufacturer or after refilling, it is difficult to touch the pole 45 with the air and the pole 45 is corroded. This is because it is none other than suppression.

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

  In FIG. 9, the symbol “LLV” indicates the lowest liquid level line of the electrolytic solution U. Moreover, in FIG. 9, the same code | symbol is attached | subjected about the component which is common in the lead storage battery 10 demonstrated in the said embodiment. FIG. 9 is a diagram in which the electrolytic solution U is omitted in order to easily display the highest liquid level line ULV and the lowest 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. 9, the position of the lower end 465A of the sleeve 465 is in the height direction (Y In the direction), it is also included in the technical scope of the present invention if it is equal to or greater than the lower surface 41A 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 hole edge of the liquid injection hole 463 toward the battery case 420. The sleeve 465 has a cylindrical shape in which a slit 467 is provided on the peripheral side surface, and is provided for visually confirming 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 to be distorted. Therefore, by visually recognizing the electrode plates 30A and 30B through the sleeve 465, the electrolyte solution U It can be visually confirmed whether the surface L reaches the lower end of the sleeve 465, that is, the highest liquid surface position. Then, 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 equal to or higher than the lower surface 41A of the bushing 41, the lead storage battery 410 is used in a state where the liquid level L of the electrolyte U is higher than the lower surface 41A of the bushing 41. This is because the pole 45 becomes difficult to touch the air and corrosion of the pole 45 can be suppressed.

  In the example of FIG. 9, the lid member 450 has a double structure of the inner lid 460 and the upper lid 470, and the inner lid 460 side that seals the upper surface of the battery case 420 corresponds to each cell chamber 25. A liquid hole 463 and a sleeve 465 are provided. In addition, 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 injected into 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 electrolyte U in the exhaust passage R are refluxed to the cell chamber 25 between them. Although the holes 95 are provided, it is not always necessary to provide a structure for refluxing the electrolytic solution U. That is, a structure in which the lid member has a single lid structure and the electrolyte U is refluxed may be eliminated.

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

  Further, if the “minimum liquid level position corresponding to 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 highest liquid level position side corresponding to the upper limit, and the electrolytic solution U is reduced. It may be easy to escape to the outside. Therefore, in such a case, the “maximum liquid surface 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 so as to ensure the distance from the liquid surface to the lid member 50. May be. If the “maximum 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, a part of the pole column 45 is exposed from the liquid level when the liquid level drops. The liquid level of the electrolyte U is eventually returned to the “maximum liquid level position corresponding to the upper limit” by replenishment of the replenisher. For this reason, the period during which a part of the pole column 45 is exposed is shorter than that in the prior art, so that the progress of corrosion of the pole column 45 can be delayed.

DESCRIPTION OF SYMBOLS 10 ... Lead storage battery 20 ... Battery case 30 ... Electrode group (an example of "power generation element" of the present invention)
41 ... Bushing 45 ... Polar pole 50 ... Lid member 60 ... Middle lid 65 ... Base part (an example of the "protruding part" of the present invention)
94 ... Gas exhaust hole 95 ... Recirculation hole 100 ... Upper lid R ... Exhaust passage U ... Electrolyte

Claims (6)

Power generation elements,
A battery case containing the power generation element;
An electrolyte contained in the battery case;
A lid member for sealing the battery case;
A cylindrical bushing made of metal embedded in the lid member, and a terminal portion connected to the power generation element and including a pole column located inside the bushing,
The terminal portion includes only one terminal connection portion to which the connection terminal is assembled,
The lead acid battery which makes the liquid level of the electrolyte solution in the said battery case the height more than the lower surface of the said bushing. Power generation elements,
A battery case containing the power generation element;
An electrolyte contained in the battery case;
A lid member for sealing the battery case;
A cylindrical bushing embedded in the lid member, and a terminal portion that is connected to the power generation element and includes a pole column 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 connection portion to which the connection terminal is assembled,
The lead acid battery which makes the liquid level of the electrolyte solution in the said battery case the height more than the lower surface of the said bushing. The lead-acid battery according to claim 1 or 2,
The lid member is
An inner lid for sealing the battery case;
An upper lid mounted on the upper surface of the inner lid,
Between the inner lid and the upper lid, an exhaust passage for exhausting the gas generated in the battery case to the outside is formed,
A lead-acid battery in which the inner lid is provided with a reflux hole for refluxing 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 exhaust passage is a lead storage battery formed in the protruding portion. The lead storage battery according to claim 1 or 2,
The lid member is
A liquid injection hole for injecting an electrolyte into the battery case;
A sleeve provided around the liquid injection hole and extending toward the battery case;
The lower end position of the said sleeve is a lead acid battery which is more than the lower surface of the said bushing in a height direction. The lead-acid battery according to any one of claims 1 to 5,
The lead acid battery which suppresses corrosion of the said pole column by immersing the said pole column which protrudes below from the lower surface of the said bushing in the said electrolyte solution.

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