JP6646353B2 - Lead storage 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 and a battery case that stores an electrolyte, a lid member that seals the battery case, and a terminal unit. The terminal portion is composed of a lead alloy bushing integrated with the lid member by insert molding, and a pole inserted through the bushing (see Patent Document 1 below).

  By the way, the electrolytic solution to be filled in the battery case is set to a height of the liquid level, usually near the upper end of the connected body, so that the entire electrode group including the connected body is immersed below the liquid level. (See FIG. 2 of Patent Document 2 below). Therefore, of the poles, the upper side of the connecting body is exposed from the electrolytic solution.

JP 2012-94372 A

JP 2010-267507 A

If the pole is partially exposed, it may corrode. Even in the initial state at the time of shipment from the manufacturer or after a certain period such as after rehydration, part of the pole is exposed by raising the level of the electrolyte above the lower surface of the bushing, compared to the conventional case where part of the pole is always exposed It was required to shorten the period to slow the progress of the corrosion of the pole.
The present invention has been completed on the basis of the above circumstances, and has an object to slow down the progress of corrosion of a pole.

  The lead storage battery of the present invention disclosed by the present specification is a power generating element, a battery case that houses the power generating element, an electrolytic solution 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 connected to the power generating element and located inside the bushing, the level of the electrolyte in the battery case, Make the height higher than the lower surface.

  In addition, whether or not the liquid level of the electrolytic solution is equal to or higher than the lower surface of the bushing is determined based on the use condition in which the battery case is placed on a horizontal surface with the bottom wall down (that is, the battery case is not tilted). In, shall be determined. That is, when 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 down, it corresponds to the lead storage battery of the present invention.

  Also, the level of the electrolytic solution does not need to be constantly maintained at a level equal to or higher than the lower surface of the bushing. For example, if the liquid level of the electrolyte is higher than the lower surface of the bushing in the initial state at the time of shipment from the manufacturer or after rehydration, even if the liquid level of the electrolyte drops below the lower surface of the bushing due to subsequent use, It corresponds to the lead storage battery of the invention.

ADVANTAGE OF THE INVENTION According to the lead storage battery of this invention disclosed by this specification, the progress of corrosion of a pole can be slowed down by shortening the period which a part of pole is exposed.

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 the lead storage battery (sectional view taken along line AA in FIG. 1) Top view of inner lid Top view of top lid Bottom view of 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 a reflux path of the electrolyte). Vertical sectional view of a lead storage battery according to another embodiment of the present invention.

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 containing the power generation element, an electrolytic solution contained in the battery case, a lid member for closing the battery case, and a cylindrical shape embedded in the lid member. It connected to bushings, and the power generating element, and a terminal portion including a pole located inside the bushing, said terminal portion, e only one Started the terminal connection part connecting terminal is assembled The liquid level of the electrolytic solution in the battery case is set at a height equal to or higher than the lower surface of the bushing for at least one time . In this configuration, the level of the electrolytic solution is higher than the lower surface of the bushing even in the initial state at the time of shipment from the manufacturer or after a period of water replenishment. By shortening the period in which the portion is exposed, the progress of corrosion of the pole can be slowed.

  In the present lead-acid 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 so that the inner lid and the upper lid are disposed 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 return hole for returning the electrolyte in the exhaust passage to the battery container.

  In order to immerse the poles in the electrolytic solution, it is necessary to raise the 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 a part of the electrolytic solution in the battery case is scattered by vibrations such as running, and easily escapes from the gas exhaust hole to the outside. In this regard, in this configuration, the exhaust passage is provided between the inner lid and the upper lid, and the electrolyte in the exhaust passage is returned to the battery case through the return hole. Therefore, for example, even if a part of the electrolytic solution in the battery case is scattered by vibrations such as running 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-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 that protrudes upward, and the exhaust passage is provided on the protruding portion. Is formed. In this configuration, since the upper lid is provided at a position higher than the bushing, even if a metal member or the like is placed on the upper part of the battery, it is difficult to make contact with the bushing, thereby preventing conduction. it can. Then, the protrusion is disposed in an upper space formed by providing the upper lid to a position higher than the bushing, and an exhaust passage is formed in the protrusion. Thereby, the exhaust passage can be formed at a position away from the battery case, and escape of the electrolytic solution can be further suppressed.

  In the present lead-acid battery, a power generating element, a battery container having an outer wall and containing the power generating element, an electrolytic solution contained in the battery container, a lid member for closing the battery container, and embedded in the lid member Cylindrical bushing, and a pole connected to the power generating element and located inside the bushing, at a position on the outer wall of the battery case at a position higher than the lower surface of the bushing in the height direction. A maximum liquid level line indicating the maximum liquid level position of the electrolyte is provided. When the maximum liquid level line is equal to or higher than 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 has reached 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 containing the power generation element, an electrolytic solution contained in the battery case, a lid member for closing the battery case, and a cylindrical shape embedded in the lid member And a pole connected to the power generating element and located inside the bushing, wherein the lid member is configured to have a liquid injection hole for injecting an electrolyte into the battery container, and the liquid injection hole. And a sleeve extending toward the battery case, wherein a lower end position of the sleeve is higher than a lower surface of the bushing in a height direction. The sleeve is provided for visually checking whether the liquid level of the electrolytic solution has reached 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 higher than the lower surface of the bushing, the liquid level of the electrolytic solution of the battery is higher than the lower surface of the bushing in a state where the electrolytic solution has reached 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>
Embodiment 1 will be described with reference to FIGS. 1 to 8.
1. Structure of Lead-Acid Battery 10 The lead-acid battery 10 includes a battery case 20, an electrode group 30 as a power generation element, an electrolyte U, and a lid member 50, as shown in FIGS. In the following description, the width direction of the battery case 20 (the direction in which the terminal portions 40A and 40B are arranged) is defined as the X direction, the height direction of the battery case 20 is defined as the Y direction, and the depth direction is defined as the Z direction.

  The battery case 20 is made of a synthetic resin. The battery case 20 has four outer walls 21 and a bottom wall 22 and has a box shape with an open upper surface. The inside 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 width direction of the battery case 20 (X direction in FIG. 2), 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 separating the two electrode plates 30A and 30B. Each of the electrode plates 30A and 30B is configured by filling an active material into a lattice body, and has ears 31A and 31B at the upper part. The ear portions 31A and 31B are provided to connect the electrode 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 of 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 the connection portions 33 formed on the straps 32, thereby connecting the electrode plate groups 30 of the respective 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 a synthetic resin and has a size capable of sealing the upper surface of the battery case 20. On the back surface of the inner lid 60, a lid partition (not shown) is formed corresponding to the partition 23. The inner lid 60 is attached so as to overlap the battery case 20, and has a structure that seals an upper surface of the battery case 20 and hermetically seals each cell chamber 25 in the battery case 20. The upper lid 100 is made of a synthetic resin similarly to the inner lid 60, and is attached to a trapezoidal 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. In addition, the trapezoidal part 65 is an example of the “projection part” of 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, and an electrolytic solution U and water vapor in the exhaust passage R are supplied to each cell chamber 25. A reflux hole 95 for refluxing the air is provided, and these structures will be described later in detail.

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

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

  As shown in FIG. 3, the terminal part 40 </ b> A on the positive electrode side includes a bushing 41 and a pole 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 penetrates a cylindrical mounting portion 63 integrally formed with the inner lid 60, and an upper half protrudes from the upper surface of the inner lid 60. The upper half of the bushing 41 that is 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 attached thereto.

  Since the inner lid 60 is integrally molded by flowing resin into a mold in which the bushing 41 is inserted, the mounting portion 63 is integrated with the bushing 41 and has a structure that covers the lower periphery of the bushing 41 without gaps. That is, the bushing 41 has a structure in which the other portion 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. In addition, a bottom wall 64 surrounding the lower surface of the bushing 41 is formed in the mounting portion 63.

  The pole 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 45 is longer than the bushing 41, and the upper part of the pole 45 is located inside the bushing 41, and the lower part protrudes 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 electrode plate group 30.

2. Liquid Surface Height 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 changed to the lower surface of the bushing 41. Set to the same height as 41A. Specifically, as shown in FIG. 3, when the battery case 20 is placed on a horizontal surface with the bottom wall 22 facing down, the battery case is adjusted so that the liquid level L is the same as the lower surface 41 </ b> A of the bushing 41. The amount of the electrolytic solution U with respect to 20 is set. When the liquid surface L of the electrolytic solution U is at the same height as the lower surface 41A of the bushing 41, the pole 45 projecting 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 45 does not come into contact with air in the battery case 20, so that corrosion of the pole 45 can be suppressed.

  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 immersed in the electrolytic solution U. It is feared that the electrolytic solution U crawls up the gap. However, the rising 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 part of the mounting portion 63 that covers the outside of the bushing 41 has the electrolytic solution. Whether it is immersed in the solution U does not affect the ease with which the electrolyte solution U crawls.

3. FIG. 4 is a plan view of the inner lid 60 viewed from above. A trapezoidal portion 65 is provided on the inner surface in the Z direction (upper side in FIG. 4) of the upper surface of the inner lid 60. The trapezoidal part 65 is one step higher than the base part (the part where the terminal part 40A and the terminal part 40B are formed) 61 of the inner lid 60, and crosses the six cell chambers 25 provided in the battery case 20. Are extended in the X direction.

  As shown in FIG. 4, on the upper surface 65 </ b> A 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 inside the peripheral wall 72 in the X direction, and partition the area inside the peripheral wall 72 into six liquid injection chambers 71. 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). Similarly to the liquid injection chamber 71, the exhaust chamber 81 has a peripheral wall 82 formed so as to surround the six exhaust chambers 81. The inner area of the peripheral wall is divided into six exhaust walls by five partition walls 83 formed in the X direction. It is structured to partition into a chamber 81.

  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 alternately formed 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. On one side of the partitioned small chamber 91, a gas discharge hole 94 is formed, and on the other side, a return hole 95 is provided. The gas discharge hole 94 and the return hole 95 penetrate the inner lid 60 up and down, and have a structure communicating with each cell chamber 25 in the battery case 20. Note that a cutout 92A is formed in the peripheral wall 92, and the small chamber 91 has a structure communicating with the exhaust chamber 81 through the cutout 92A.

  In the exhaust chambers 81 located at both ends in the X direction, centralized exhaust portions 97 are formed. The centralized exhaust section 97 has 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, 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 trapezoidal portion 65 of the inner lid 60, as shown in FIGS. Has been established. An outer peripheral wall 110 is formed on an 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, corresponding to the peripheral walls 72, 82 and the partitions 73, 83 provided on the trapezoidal portion 65, the peripheral walls 172, 182 and the partitions 173 having the same shape are provided. , 183 are formed. Therefore, by mounting the upper lid 100, the upper surfaces of the liquid injection chambers 71 formed on the base 65 and the exhaust chambers 81 can be sealed. On the back surface of the upper lid 100, two partition plates 185 and 186 are formed corresponding to the two partition plates 85 and 86, and a peripheral wall 198 is formed corresponding to the peripheral wall 98 forming the centralized exhaust unit 97. I have. Further, a partition wall 193 is formed corresponding to the partition wall 93 that partitions the small chamber 91. A notch 193 </ b> A is formed in the partition wall 193, and the partition wall 193 has a structure in which gas and electrolyte can flow in the small chamber 91.

  As shown in FIG. 7, each exhaust chamber 81 forms a maze-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 be injected. The structure extends to the boundary with the chamber 71.

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

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

  In addition, the floor surface of each exhaust chamber 81 is inclined so as to be lower as it is closer to 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 holes 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 electrolytic solution U and water vapor flow toward the return hole 95 as shown by the dashed arrow in FIG. Therefore, the electrolytic solution U and water vapor contained in the gas can be returned to each cell chamber 25.

4. Description of Effect In the present lead-acid battery 10, the pole 45 is less likely to come into contact with air because it is immersed in the electrolyte U. Therefore, corrosion of the pole 45 can be suppressed. Further, in order to immerse the pole 45 in the electrolyte U, it is necessary to raise the liquid level L of the electrolyte U higher than usual. Note that “normal” means a state in which the liquid level of the electrolytic solution U is adjusted to the upper end of the connection portion 33 as indicated by a line “Lo” in FIG.

  When the liquid level L is raised, the distance to the gas exhaust holes 94 becomes short, and a part of the electrolytic solution U in the cell chamber 25 is scattered by vibrations such as running, and escapes from the gas exhaust holes 94 to the outside. Easy to put out. In this regard, the lead storage 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 electrolyte U in the exhaust passage R is returned to the cell chamber 25 through the return hole 95. Therefore, for example, even if a part of the electrolytic solution U is scattered due to vibrations such as running and enters the gas exhaust holes 94, the electrolytic solution U returns to the cell chamber 25 from the return holes 95. Therefore, escape of the electrolytic solution U can be suppressed.

  In addition, 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 to prevent conduction. Can be. Then, the trapezoidal portion 65 is arranged in an 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. Accordingly, the exhaust passage R can be formed at a position separated from the battery case 20 upward, and the escape of the electrolytic solution can be further suppressed.

  Further, in the present lead-acid storage battery 10, it is necessary to keep the level of the electrolytic solution U high so that the poles 45 are immersed, and more electrolytic solution is stored in the battery case 20 than in a normal battery in which the poles 45 are partially exposed. U needs to be filled. However, if the liquid level L of the electrolytic solution U is high, the sizes (dimensions in the Y direction) of the electrode plates 30A and 30B can be set larger accordingly. Therefore, the lead storage battery 10 can have higher battery performance than a normal battery in which the pole 45 is partially exposed.

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

  (1) In the above 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, if the pole 45 in the battery case 20 is immersed in the electrolytic 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) The liquid level L of the electrolytic solution U does not need to always maintain the height equal to or higher than the lower surface 41A of the bushing 41, and it is sufficient that the liquid surface L be equal to or higher than the lower surface 41A of the bushing 41 at any 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 a state after rehydration, the liquid level L of the electrolytic solution U is changed to the lower surface of the bushing 41 by subsequent use. Even if it falls below 41A, it falls within the technical scope of the present invention. The reason is that even if the liquid level L of the electrolytic solution U is higher than the lower surface 41A of the bushing 41, even in an initial state at the time of shipment from the manufacturer or after rehydration, the pole 45 is hardly exposed to air and corrosion of the pole 45 is prevented. This is because it is nothing but suppression.

  (3) 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 determined by the bushing in the height direction (Y direction). A lead storage battery 410 that is not less than the lower surface 41A of 41 is also included. This is because the amount of the electrolyte solution U is adjusted by water replenishment at the time of manufacture or use so that the liquid level L reaches the maximum liquid level line ULV. 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 410 has a liquid level L of the electrolytic solution U higher than the lower surface 41A of the bushing 41. As a result, the pole 45 is less likely to come into contact with air, and corrosion of the pole 45 can be suppressed.

  In FIG. 9, reference numeral “LLV” indicates the lowest liquid level line of the electrolytic solution U. In FIG. 9, components common to the lead storage battery 10 described in the above embodiment are denoted by the same reference numerals. FIG. 9 is a diagram in which the electrolyte 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 to the lid member 450, as shown in FIG. 9, the position of the lower end 465A of the sleeve 465 is set in the height direction (Y (Direction), which is not less than the lower surface 41A of the bushing 41, is also included in the technical scope of the present invention. More 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 has a cylindrical shape with a slit 467 provided on the peripheral side surface, and is provided for visually checking the height of the liquid level L of the electrolytic solution U. That is, when the electrolyte U reaches the lower end of the sleeve 465, the electrodes 30A and 30B in the electrolyte appear to be distorted. It can be visually recognized whether the surface L reaches the lower end of the sleeve 465, that is, the highest liquid level position. Then, the amount of the electrolytic solution U is adjusted such that the liquid level L reaches the lower end 465A of the sleeve 465 at the time of shipment from the manufacturer or by water replenishment. 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 electrolytic solution U is higher than the lower surface 41A of the bushing 41. This is because the pole 45 is less likely to come into contact with 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, which seals the upper surface of the battery case 420, is provided with a cover corresponding to each cell chamber 25. A liquid hole 463 and a sleeve 465 are provided. Further, the upper lid 470 is provided with each liquid injection hole 473 corresponding to each liquid injection hole 463 on the inner lid 460 side, and the electrolyte U is injected into the liquid injection hole 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 the 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 both. Although the holes 95 are provided, a structure for refluxing the electrolyte U is not necessarily provided. In other words, the lid member may have a single-lid structure, and the structure for refluxing the electrolyte U may be omitted.

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

  When the “lowest 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 shorter on the highest liquid level position side corresponding to the upper limit, and the electrolytic solution U becomes It may be easy to escape to the outside. Therefore, in such a case, 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 so as to secure the distance from the liquid level to the lid member 50. You may. When 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, a part of the pole 45 is exposed from the liquid level when the liquid level is lowered. Then, the level of the electrolytic solution U is eventually returned to the “maximum level level corresponding to the upper limit” by replenishment of the replenisher. Therefore, the period during which a part of the pole 45 is exposed is shorter than that in the related art, so that the progress of corrosion of the pole 45 can be slowed down.

10 Lead storage battery 20 Battery case 30 Electrode group (an example of "power generation element" of the present invention)
41 ... bushing 45 ... pole column 50 ... lid member 60 ... middle lid 65 ... trapezoidal part (an example of "projecting part" of the present invention)
94 ... gas exhaust hole 95 ... recirculation hole 100 ... top lid R ... exhaust passage U ... electrolyte

Claims (4)

Power generation elements,
A battery case containing the power generating element,
An electrolytic solution contained in the battery case,
A lid member for closing the battery case,
A cylindrical bushing embedded in the lid member, and a terminal portion connected to the power generating element and including a pole located inside the bushing,
The terminal unit includes only one terminal connection unit to which the connection terminal is attached,
A lead-acid battery in which the level of the electrolytic solution in the battery case is at least as high as the lower surface of the bushing for at least one period . The lead-acid battery according to claim 1,
The lid member,
An inner lid for sealing the battery case,
And an upper lid mounted on the upper surface of the inner lid,
An exhaust passage for exhausting gas generated in the battery case to the outside is formed between the inner lid and the upper lid,
A lead-acid battery, wherein the inner lid is provided with a reflux hole for refluxing the electrolyte in the exhaust passage into the battery case. The lead storage battery according to claim 2, wherein
The upper surface of the upper lid is located above the upper surface of the bushing,
The inner lid has a protrusion protruding upward,
The lead storage battery, wherein the exhaust passage is formed in the protrusion. The lead-acid battery according to claim 1,
The lid member,
An injection hole for injecting the electrolyte into the battery case,
A sleeve provided around the liquid injection hole and extending toward the battery case,
A lead-acid battery in which a lower end position of the sleeve is higher than a lower surface of the bushing in a height direction.

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