JP4715091B2 - Lead acid battery - Google Patents

Description

  The present invention relates to a lead-acid battery having an exhaust structure that discharges gas while preventing escape to an electrolytic solution.

  The exhaust structure of a monoblock type lead-acid battery having a plurality of cells is roughly divided into an individual exhaust system in which an exhaust plug is provided for each cell, and a gas exhausted from each cell is temporarily guided to the exhaust chamber. There is a batch exhaust system that concentrates gas from the exhaust and discharges it to the outside. Compared to the individual exhaust system, the collective exhaust system requires fewer parts and the volume of the upper space of the electrode plate can be reduced, and the battery can be reduced in size without reducing the capacity of the battery. In addition, because of the advantages such as the escape amount of the electrolyte, it has been widely adopted for in-vehicle lead acid batteries.

Conventionally, several proposals have been made regarding collective exhaust of lead-acid batteries in order to prevent the electrolyte from escaping out of the battery in the form of mist or vapor and to smoothly discharge the gas so that the internal pressure of the battery does not rise. Has been. For example, a gas containing electrolyte mist and vapor flows in the exhaust chamber in the horizontal direction. During this time, the electrolyte mist and vapor are condensed to separate the gas and electrolyte, and the gas is discharged to the outside. The electrolyte solution is refluxed into the cell. (See Patent Document 1 and Patent Document 2)
U.S. Pat. No. 4,486,516 JP-A-8-22815

In order to increase the efficiency of separation of gas and electrolyte, a structure of collective exhaust in which the distance that the gas flows in the horizontal direction is made as long as possible has been proposed. (See Patent Document 3)
JP 2001-84981 A

In addition, a porous filter is placed at the gas outlet from the exhaust chamber to the outside of the battery to prevent discharge of mist and vapor from the electrolyte, and a space is provided below the filter to wet the filter with the electrolyte. An exhaust structure that prevents clogging is proposed. (See Patent Document 4)
JP-A-6-176748

  In a lead-acid battery for in-vehicle use, the electrolytic solution surface undulates when the vehicle vibrates, or the electrolytic solution surface tilts when the vehicle is climbed up. In the methods proposed in Patent Documents 1 to 3, when the electrolytic solution surface is wavy or inclined, the electrolytic solution is exhausted through a gas discharge port communicating with the cell and the exhaust chamber. There was a risk of jumping into the room. Further, when the battery is accidentally turned over, the electrolyte may overflow from the exhaust chamber to the outside of the battery.

  The present invention has been made in view of the drawbacks of conventional lead-acid batteries that employ a batch exhaust system, and is intended to provide a lead-acid battery that is excellent in gas discharge function and electrolyte escape prevention function. .

In this invention, the said subject is solved by making the exhaust structure of a lead storage battery into the following structures.
(1) A lead storage battery according to the present invention includes a battery case that houses a plurality of cells, an inner lid that covers an upper surface of the battery case, and an upper lid that covers a concave portion of the inner lid, and the concave portion of the inner lid and the upper lid, A space surrounded by a partition wall, and at least one centralized exhaust chamber communicating with the exhaust chamber, the gas generated from the cell being gas In the lead storage battery having a mechanism for exhausting the exhaust gas collectively through the exhaust port, the exhaust chamber, and the concentrated exhaust chamber, an electrolyte solution return port is provided for refluxing the electrolyte solution discharged together with the gas into the cell. A small chamber surrounding the gas discharge port is provided in a part of the exhaust chamber, and the gas discharge port and the electrolyte reflux port are separated from each other on the cell side of the inner lid and extend toward the inside of the cell. A cylindrical body is provided, and the gas discharge port Is a lead-acid battery, characterized in that a notch or hole in the wall of the tubular body.
(2) A lead storage battery according to the present invention is the lead storage battery according to (1), wherein the gas discharge port is an oval or rectangular opening.
(3) The lead storage battery according to the present invention is the lead storage battery according to (1) or (2) described above, wherein the local floor provided with the gas discharge port in the floor of the exhaust chamber is compared with the surrounding area. It is the lead acid battery characterized by having arrange | positioned in the position far from the electrolyte solution surface.

According to the battery of the present invention described in the above (1) and (3), the lead of the collective exhaust system with a small risk of leakage of the electrolyte even when the electrolyte surface in the cell is wavy or the battery is inclined. It can be set as a storage battery.
According to the battery of the present invention described in the above (2) and (3), a lead storage battery in which the gas discharge port can be hardly blocked with an electrolyte or foreign matter, and gas can be smoothly transferred from the cell to the exhaust chamber; can do.

Hereinafter, the details of the present invention will be described with reference to one embodiment, but the present invention is not limited thereto.
FIG. 1 is a perspective view of a 6-cell monoblock type lead-acid battery 1 according to an embodiment of the present invention with the top cover removed, as viewed obliquely from above. Reference numeral 2 denotes a battery case, the interior of which is divided into 6 cells by 5 partition walls (not shown) arranged in parallel to the short side of the side of the battery, and one set of positive electrodes for each cell. An electrode plate group consisting of a plate, a negative electrode plate and a separator and an electrolyte solution (not shown) consisting of dilute sulfuric acid are housed. In FIG. 1, 3 is an inner lid mounted on the battery case 2, and 4 is an upper lid mounted on a recess of the inner lid 3. The battery case 2, the inner lid 3, and the upper lid 4 are all molded articles made of polypropylene, and the upper end of the side wall (not shown) of the battery case 1, the lower end of the side wall of the inner lid 2 (not shown), and the inner lid 3. The upper end of the partition wall provided in the recess and the lower end (not shown) of the partition wall of the upper lid are heat-sealed and each is airtightly joined. In addition, 5 is a positive electrode terminal made of lead alloy, and 6 is a negative electrode terminal made of lead alloy.

  FIG. 2 is a view of the inner lid 3 as viewed from the direction facing the cell. The hatched portions are the end face of the side wall 31 and the end face of the partition wall 32 which are joined to the open end face of the side wall of the battery case 2 and the cell interval wall (not shown) by thermal fusion. The battery is divided into six cells by five partition walls 32. The floor 33 of the inner lid 3 is provided with openings having the same number of gas discharge ports 34 and electrolyte solution reflux ports 35 as the number of cells, and the cells and the exhaust chamber are communicated with each other through the openings.

  On the wall surface facing the cell of the floor 33 of the inner lid 3, a cylindrical body 36 surrounding the gas discharge port 34 and extending toward the cell, and a cylindrical body 37 surrounding the electrolyte reflux port 35 and extending toward the cell. Is arranged.

  FIG. 3 is a cross-sectional view of the inner lid 3 shown in FIG. 2 taken along line AA in FIG. For ease of understanding, FIG. 3 shows the side wall 21 of the battery case 2, the opening end of the cell spacing wall 22, and a part of the upper lid 4. The end face of the partition provided on the wall facing the cell in the floor 33 of the inner lid, the side wall 21 of the battery case 2, and the opening end of the cell spacing wall 22 are airtightly joined by heat sealing. In addition, the partition wall provided in the concave portion on the upper surface of the floor 33 of the inner lid and the partition wall provided on the inner surface (the lower surface in the figure) of the upper lid 4 are airtightly joined by heat fusion. An enclosed exhaust chamber 41 is formed. The gas generated from the cell reaches the small chamber 42 through the gas discharge port, passes through the notch 43 provided in the partition wall of the upper lid 4, moves to the exhaust chamber 41, and then concentrates in the exhaust chamber 41 communicating with the exhaust chamber 41 ( (Not shown) and discharged out of the battery via the central exhaust chamber. While the gas is moving through the exhaust chamber 41, mist or vapor of the electrolyte mixed in the gas is condensed to become a liquid, and is refluxed from the exhaust chamber 41 into the cell through the electrolyte reflux port 35.

  As described above, the inner lid floor 33 is provided with the cylindrical body 36 surrounding the gas discharge port 34 and extending toward the cell, and the cylindrical body 37 surrounding the electrolyte reflux port 35 and extending toward the cell. In the cylindrical body, when the electrolyte surface in the cell undulates, the top of the wave (the wave front) and the splash of the electrolyte generated by the wave colliding with the wall surface of the battery case are the gas discharge port 34 and the electrolyte reflux port. It works to prevent reaching 35.

  In addition, by setting the lower end 38 of the cylindrical bodies 36 and 37 to be immersed in the cell electrolyte (the lower end 38 of the cylindrical bodies 36 and 37 is below the electrolyte surface), It divides into a small area and has the function which suppresses electrolyte solution reaching the gas exhaust port 34 or the electrolyte solution return port 35 when a battery inclines. Although the thickness and cross-sectional shape of the cylindrical body 36 and the cylindrical body 37 are not particularly limited, the electrolytic solution is prevented from reaching the gas discharge port 34 or the electrolytic solution reflux port 35 when the battery is tilted. For this purpose, it is desirable to divide the electrolyte surface in as small an area as possible, and it is preferable that the cylindrical bodies 36 and 37 have a small thickness.

  In the present invention, it is preferable to provide a notch or a through hole 39 on the wall surface of the cylindrical body 36 that surrounds the gas discharge port 34 and extends toward the cell. The size and position of the notches and the through holes 39 are not particularly limited, but in order to prevent the electrolyte from reaching the gas discharge port 34 when the electrolyte is waved as described above, Is preferred. However, in order to smoothly discharge the gas from the cell, it is desirable that the upper end of the notch 39 is on the electrolyte surface even when the electrolyte in the cell is undulated or the battery is tilted. Further, it is preferable that when the cylindrical body is wetted with the electrolytic solution, the electrolytic solution forms a liquid film so that the cutout and the through hole 39 are not blocked. In order to satisfy such a condition, it is preferable that the notches and the through holes 39 provided in the cylindrical body 36 have a vertically long shape. This prevents the electrolyte from reaching the gas outlet 34 when the notch or the upper end of the through hole 39 is set above the electrolyte surface and is made as thin as possible to prevent the electrolyte from undulating. It is possible to prevent the notch and the through-hole 39 from being blocked by the electrolyte liquid film.

  FIG. 4 is a cross-sectional view taken along the line BB in FIG. As described above, the vertically long notch and the through hole 39 are provided on the wall surface of the cylindrical body 36.

  In the present invention, as described above, the notch and the through hole 39 are provided on the wall surface of the cylindrical body 36 that surrounds the gas discharge port 34 and extends toward the cell. The electrolyte droplets easily reach the gas discharge port 34 when the gas is discharged. Electrolyte droplets reaching the gas discharge port 34 may form a liquid film at the gas discharge port 34 to be blocked. If the gas distribution outlet is closed with a liquid film and the condensed electrolytic solution accumulates on the gas distribution outlet, there is a possibility that the gas discharge through the gas outlet 34 may be hindered from being discharged 34 from the cell. In order to prevent the formation of a liquid film, it is preferable that the shape of the gas outlet 34 is not a circle or a square but an elongated oval or rectangle as shown in FIG.

  In addition, a liquid film is formed at the gas outlet 34 and the gas outlet 34 is blocked, or foreign substances (such as sponge-like lead dropped from the electrode plate) floating on the electrolyte surface are clogged at the gas outlet 34. 3 and 4, the local floor 40 including the gas discharge port 34 is disposed at a higher position than the floor 33 of the inner lid, as shown in FIGS. 3 and 4. It is further preferable to increase the distance.

  Further, a partition wall 43 is provided so as to surround the local floor 40 provided with the gas discharge port 34 provided in the floor 33 of the inner lid, the small chamber 42 is partitioned, and the electrolytic solution condensed in the exhaust chamber 41 does not enter the small chamber 42. At the same time, the gas discharged from the cell is preferably transferred to the exhaust chamber 41 through the notch 44 provided in the partition wall 43 of the upper lid 4.

It is the perspective view which looked at the state which removed the upper cover of the lead acid battery concerning the present invention from the slanting upper part. It is the top view which looked at the inner lid of the lead storage battery concerning the present invention from the cell side. It is a top view which shows the inner surface of the upper cover which concerns on this invention. It is sectional drawing of a cylindrical body.

3 Middle lid 4 Upper lid 33 Exhaust chamber floor 34 Gas exhaust port 35 Electrolyte reflux port 35, 37 Tubular body 40 Local floor 41 Exhaust chamber

Claims (3)

A battery case that houses a plurality of cells; an inner lid that covers an upper surface of the battery case; and an upper lid that covers a concave portion of the inner lid, forming a space surrounded by the concave portion of the inner lid and the upper lid; There are as many exhaust chambers as the cells partitioned by partition walls in the space and at least one concentrated exhaust chamber communicating with the exhaust chambers, and gas generated from the cells is provided as a gas exhaust port, the exhaust chambers, and the concentrated exhaust chambers. In a lead-acid battery having a mechanism for exhausting all of the gas to the outside via an electrolyte, a recirculation port for recirculating the electrolyte discharged together with the gas into the cell is provided, and the gas is provided in a part of the exhaust chamber. provided chamber surrounding the outlet, and the cell side of the inner lid, surrounds each isolates the gas outlet and the electrolyte recirculation opening, a tubular body provided extending toward the inside of the cell, the gas outlet side A notch on the wall of the cylinder Lead-acid batteries, characterized in that a through-hole. The lead acid battery according to claim 1, wherein the gas discharge port is an oval or rectangular opening. 3. The lead acid battery according to claim 1, wherein a local floor provided with the gas discharge port among the floors of the exhaust chamber is disposed at a position farther from the electrolyte surface of the cell than the periphery thereof. 4. .

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