JP2008198563A - Lead acid storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lead acid storage battery in which an electrode plate unit is used wherein a positive electrode and a negative electrode are integrated at a connecting part, and in which liquid-tightness of the connecting part between cells is improved. <P>SOLUTION: This is the lead acid storage battery 1 in which a plurality of cells are connected in series at the connecting parts between the cells. In the cells 31', positive electrode plates and negative electrode plates of the respectively same number of sheets are laminated via a separator, the cells are housed in a cell room 53 in which the interior of a battery case is partitioned by a barrier rib 52, and an electrode plate unit in which the respective positive electrodes housed in one cell room partitioned by the barrier rib and the respective negative electrodes of the other cell room are electrically connected via the connecting part 2c is arranged. An opening is provided at the bottom of the battery case 51, and the bottom cap 59 is attached to this opening. This bottom cap has a sealing agent pot 59b to house the end part of the barrier rib and the connecting part, and by filling the sealing agent 60 into this sealing agent pot, the connecting parts between the cells are sealed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lead-acid battery.

  Lead-acid batteries are widely used for starting an engine of a vehicle, supplying power to various auxiliary machines, lights, and the like. In a general lead-acid battery, a plurality of positive plates, negative plates and separators are stacked, and electrode plates having the same polarity are joined together to form an electrode plate group. The electrode plates are joined by connecting current collecting ears provided on the electrode plates with a lead or lead alloy shelf. A connection body made of lead or lead alloy for connecting cells is integrally provided on the shelf, and a necessary voltage is secured by connecting the electrode plate groups in series with this connection body.

  In the lead storage battery having the above-described configuration, all currents flowing from or to the electrode plates are collected on the shelves, so that a large current flows through the shelves and the connection body connecting the shelves. Therefore, it is necessary to secure a sufficient cross-sectional area of the shelf and the connection body so that the shelf and the connection body are not melted by such a current.

  In this way, a lead alloy with a large cross-sectional area is required because a large charging / discharging current flows through the shelf and connection body, the lead storage battery becomes heavy, and the voltage drop at the shelf and connection body during large current discharge increases, The discharge voltage decreases and the output of the battery decreases.

  In Patent Document 1, as a lead storage battery that is lightweight and excellent in discharge voltage characteristics, it is obtained by connecting a positive electrode plate and a negative electrode plate via a link without forming a shelf or a connection body like the above lead storage battery. A bipolar plate is used, and the link of this bipolar plate is arranged in the opening provided in the cell spacing wall, the positive plate in one cell chamber partitioned by the cell spacing wall, and the negative electrode in the other cell chamber A multi-cell series lead acid battery is shown in which bipolar plates are stacked to accommodate the plates.

  The lead storage battery using the bipolar electrode plate shown in Patent Document 1 does not require a lead alloy shelf or connection body used for the inter-cell connection portion in the conventional lead storage battery, so the weight of the battery is reduced. Is possible. In the conventional lead-acid battery, the charge / discharge current concentrated on the shelves and connecting members is distributed by the number of links of the bipolar plates, and the positive and negative plates are directly connected by the links. Therefore, it is possible to obtain a high-power lead-acid battery that can further shorten the current path between the positive electrode plate and the negative electrode plate, has fewer voltage drops during charge / discharge, and has excellent large current discharge characteristics.

  In the lead-acid battery using the bipolar electrode plate disclosed in Patent Document 1, a collar having elasticity is attached to the link connecting the positive electrode plate and the negative electrode plate to the opening formed in the partition between the cells. By compressing the electrode in the thickness direction of the electrode plate, the collar itself is deformed in the width direction, whereby the opening and the collar are brought into close contact with each other, and further, the gap between the opening and the collar is filled with a sealing agent. Air tightness and liquid tightness are ensured.

  However, in the configuration of Patent Document 1, there is a gap between the collar and the link, and there is a problem that it is difficult to sufficiently secure the liquid tightness of this portion. A liquid junction was generated between the chambers, and a leakage current was generated between adjacent cells. In addition, it is necessary to attach a collar to the current collecting ear of each electrode plate unit and insert a packing between the partition plate between the cells and the collar, which makes the process complicated and difficult to automate, resulting in poor productivity. . Moreover, although patent document 1 is disclosed in detail about the structure of the connection part between cells, it does not touch on the junction structure of a battery case and a lid | cover in detail.

Patent Document 2 shows a battery having a configuration in which an electrode plate in which a positive electrode and a negative electrode are provided integrally and sealing an inter-cell connection portion with a sealant, depending on the physical properties of the sealant and the separator. In some cases, the sealant may move to the separator, and the airtightness and liquid tightness between the cell chambers may be impaired.
US Pat. No. 5,098,801 JP 2003-331909 A

  The present invention uses an electrode plate unit in which a positive electrode and a negative electrode are integrated in a connecting body, and in a lead storage battery in which a plurality of cells are connected in series, the reliability is excellent in airtightness and liquid tightness between adjacent cell chambers. High lead acid battery is provided.

  In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is a monoblock type lead-acid battery in which a plurality of cells are connected in series at inter-cell connecting portions, and each of the cells has the same number of positive electrode plates. And the negative electrode plate are stacked via a separator, and the cell is stored in a cell chamber partitioned by a partition wall inside the battery case, and stored in one cell chamber adjacent to each other via the partition wall. Each positive electrode plate and each negative electrode plate housed in the other cell chamber are equipped with an electrode plate unit that is electrically connected via a connecting portion, and has an opening at the bottom of the battery case. A bottom cover is attached to the opening, and the bottom cover has a sealant pot for storing the tip end part of the partition wall and the connection part, and the sealant pot is filled with the sealant. The lead acid battery which sealed the connection part between cells is shown by In the is.

  Furthermore, the invention according to claim 2 of the present invention is the lead-acid battery having the configuration of claim 1, provided at the outer periphery of one of the battery case and the bottom cover at the joint between the battery case and the bottom cover. The protruding portion is fitted into a groove provided on the other outer periphery, and the heating element housed in the groove is heated to melt the protruding portion and the groove, thereby the battery case and the bottom cover. 1 shows a lead storage battery in which and are heat-welded. Preferably, the heating element is arranged so as not to be exposed outside the battery, the heating element is heated by high frequency induction heating, and the battery case and the bottom cover are joined. is there.

  The lead storage battery of the present invention has the above-described configuration, and the electrode plate unit connecting portion is disposed between the partition wall and the bottom cover of the cell chamber, and this portion is embedded with a sealing agent such as an adhesive, thereby The liquid tightness of the inter-connection portion can be remarkably improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an electrode plate unit 2 used in the lead storage battery 1 of the present invention. The electrode plate unit 2 has a configuration in which a positive electrode plate portion 2a filled with a lead-acid battery positive electrode active material and a negative electrode plate portion 2b filled with a negative-electrode active material for a lead-acid battery are electrically connected via a connection portion 2c. Have.

  Various methods can be adopted as a manufacturing method of the electrode plate unit 2. A grid body having the shape of the electrode plate unit 2 may be prepared, one grid surface may be filled with a negative electrode active material, and the other grid surface may be filled with a positive electrode active material. As the lattice, conventionally known ones such as a cast lattice, a punching lattice, and an expanded lattice can be applied. For example, in the case of an expanded lattice, an expanded mesh is formed on both sides of a lead alloy sheet, a positive electrode active material is filled in the expanded mesh on one side, and a negative electrode active material is filled in the expanded mesh on the other side, followed by press cutting. The electrode plate unit 2 can be formed by cutting.

  In the present invention, together with the electrode unit 2 described above, a single positive electrode plate 3 in which the positive electrode current collector ear 3a is formed on the positive electrode plate portion 2a, and a single negative electrode plate 4 in which the negative electrode current collector ear 4a is formed on the negative electrode plate portion 2b. And the cell 31 mentioned later is comprised by laminating | stacking and the separator 5. FIG.

  As a configuration example of the cell 31, an example in which six cells 31 are connected in series will be described with reference to FIGS. 2 (a) to 2 (c).

  First, as shown in FIG. 2A, the positive electrode plate 3, the two electrode plate units 2, and the negative electrode plate 4 are arranged on the same plane. The positive electrode current collector ear 3a and the negative electrode current collector ear 4a respectively provided on the positive electrode plate 3 and the negative electrode plate 4 located at both ends are arranged so as to be positioned in the opposite direction to the connection portion 2c of the electrode plate unit 2, respectively. The arrangement of the positive electrode plate 3, the electrode plate unit 2, and the negative electrode plate 4 is a layer A.

  Next, as shown in FIG. 2B, the separator 5 is laminated on the positive electrode plate 3 constituting the layer A, the positive electrode plate portion 2 a, the negative electrode plate portion 2 b, and the negative electrode plate 4 of the electrode plate unit 2. This separator 5 is referred to as layer B.

  Further, as shown in FIG. 2 (c), the electrode plate unit 2 is laminated on the layer B to form a series electrode plate group 32. Note that a layer formed only of the electrode plate unit 2 is referred to as a layer C. FIG. 3A is a diagram showing the state of FIG. 2C viewed from the stacking direction. In the state of FIG. 2C, layer A, layer B, and layer C are sequentially stacked, A series electrode plate in which any one of the positive electrode plate portion 2a and the positive electrode plate 3 is connected in series by the connection portion 2c with cells 31 facing either one of the negative electrode plate portion 2b or the negative electrode plate 4 through the separator 5. Group 32 is formed.

  In the series electrode plate group 32 shown in FIGS. 2 (c) and 3 (a), the number of electrode plates constituting the cell 31 is one for each of the positive electrode and the negative electrode, but the present invention is limited to this. It is not something. As shown in FIG. 3B, the layer B, the layer A, the layer B, and the layer C are sequentially stacked on the layer C of the series electrode plate group 32, so that the number of electrode plates constituting each cell is positive. Each of the negative electrode and the negative electrode can be two.

  Further, by sequentially laminating the layers B-A-B-C in accordance with the battery capacity, the series electrode plate group 32 in which the cells 31 'are connected in series by the connection part 2c as shown in FIG. 'May be configured.

  In the above example, a flat separator is used as the separator 5. However, instead of the flat separator, a bag-like separator is used, and the positive electrode plate portion 2 a and the positive electrode plate 3, or the negative electrode plate is formed with this bag-like separator. It is good also as a structure which accommodates one polarity or both poles of the part 2b and the negative electrode plate 4. FIG.

  As shown in FIG. 5, the lead storage battery 1 according to the present invention has a battery case 51 having a bottom opening and a partition wall 52 defining a cell chamber 53. The series electrode plate group 32 ′ is accommodated in the battery case 51 so that the cells 31 are arranged in the respective cell chambers 53.

  In addition, as shown in FIG. 4, the positive electrode shelf 54 for collectively welding the positive electrode current collecting ear 3 a, and the positive electrode shelf 54 and the positive electrode terminal 55 before the series electrode plate group 32 ′ is accommodated in the battery case 51. Are formed integrally with the positive electrode shelf 54. Similarly to the positive electrode, with respect to the negative electrode, a negative electrode shelf 57 for collectively welding the negative electrode current collecting ear 4a and a negative electrode column 58 for connecting the negative electrode shelf 57 and the negative electrode terminal 55 'are integrated with the negative electrode shelf 57. To form.

  The positive electrode shelf 54 and the positive electrode column 56 can be formed by conventionally used burner welding or cast-on welding. With the above configuration, since the connection between the cells 31 ′ is made at the connection portion 2 c, a conventional shelf or connection body is unnecessary, the output characteristics of the lead storage battery are improved, and the battery mass can be further reduced in weight.

  As an example of forming the positive electrode terminal 55 and the negative electrode terminal 55 ′, as shown in FIG. 5, a lead alloy bushing 62 is insert-molded in the battery case 51, and the positive electrode column 56 or the negative electrode column is formed in the bushing 62. Both of these may be welded by burner welding or the like with 58 inserted.

  In the present invention, the bottom of the battery case 51 is open, and the battery case 51 is closed by attaching a bottom cover 59 to the bottom of the battery case 51. In the series electrode plate group 32 ′, the connecting portion 2 c functioning as a connecting member between the cells 31 protrudes downward, and the sealing agent 60 filled in the sealing agent pot 59 b provided on the bottom lid 59 is provided. Soaked and sealed. Further, the tip 52a of the partition wall 52 is embedded in the sealant 60, so that the air tightness and liquid tightness of the cell chamber 53 can be firmly maintained.

  Further, unlike the configuration shown in Patent Document 2, in the present invention, the sealant pot 59b suppresses the flow of the sealant 60, so that the airtightness and liquid tightness are reduced due to the lack of the sealant 60. Problems can be prevented, and a lead storage battery having excellent reliability can be obtained.

  In particular, in lead-acid batteries that have an open liquid type lead-acid battery or a control valve type that has plenty of free electrolyte released from the electrode plate group, if the liquid-tightness of the inter-cell connection portion is impaired, adjacent cells Liquid junctions and liquid movements are likely to occur between them. When a liquid junction occurs, a cell is composed of the positive electrode plate of one cell and the negative electrode plate of the other cell between adjacent cells, and these electrode plates are connected between the cells, so a short circuit occurs inevitably. Leakage current flows. In the present invention, even in such a lead storage battery having a free electrolyte that has a large influence due to a liquid junction, the liquid tightness between the cell chambers 53 is extremely high, and the occurrence of a liquid junction can be suppressed. .

  The sealant pot 59b is provided on the bottom lid 59 between the cell chambers 53 adjacent to each other. As a specific structure, a pair of pot walls 59 c facing both sides of the partition wall 52 may be formed on the bottom lid 59.

  As the sealant 60, the sealant pot 59b provided on the partition wall 52 and the bottom cover 59 is less likely to be subjected to a large stress, and thus an adhesive or a filler can be used. An epoxy adhesive or a polyolefin resin can be used. A material having acid resistance such as a hot melt is used.

  For the battery case 51 and the bottom lid 59, a polypropylene resin or a copolymer of polypropylene and polyethylene having excellent heat resistance and acid resistance can be used. In particular, in most cases, these polyolefin-based resins have poor affinity with the sealant 60. Accordingly, the flame treatment in which the burner flame is brought into contact with the sealant pot 59b or the tip 52a of the partition wall 52 or plasma treatment is performed, and the affinity with the sealant 60 on each surface of the sealant pot 59b or the tip 52a. Is preferably increased.

  When the battery case 51 and the bottom cover 59 are made of the polyolefin resin as described above, the outer wall 51a of the battery case 51 and the bottom cover 59 can be joined by thermal welding. Since the joint between the outer wall 51a of the battery case 51 and the bottom lid 59 has a high frequency of external stress such as impact, thermal welding having a higher joint strength and higher reliability than that using an adhesive is most preferable. In the lead acid battery manufacturing process of the present invention, after the series electrode plate group 32 ′ is accommodated in the battery case 51, the bottom lid 59 in which the sealant 60 is filled in the sealant pot 59 b, and the battery case 51. Can be joined by thermal welding.

  As a method of heat welding the battery case and the lid of the lead-acid battery, a heated mold called a hot plate is pressed against the welding surface of the battery case and the lid, the joining surface of the battery case and the lid is melted, Is generally used, and the bonding surface is pressed and welded while pressing the two. However, it is difficult to uniformly control the temperature of the hot plate, the pressurizing force between the hot plate, the battery case and the lid, and further the pressurizing force between the battery case and the cover on the entire welding surface. In some cases, the welding strength of the steel is not stable. In consideration of such a variation in welding strength, it is necessary to make the junction of the battery case and the lid thicker.

  Further, in the case where heat welding using a conventional hot plate is adopted, when the hot plate is pressed against the bottom lid 59, the sealing agent 60 filled in the sealing agent pot 59b adheres to the hot plate, and the hot plate The surface is easily contaminated with the sealant 60. When such contamination progresses, the sealant pot 59b and the hot plate interfere with each other in the heat welding process, the sealant pot 59b and the surrounding portion are thermally deformed, and the specified dimensional shape is impaired. Further, when the hot plate is overheated with the sealant 60, gas and off-flavor may occur.

  Further, when an epoxy resin having a high curing rate is used for the sealant 60, the epoxy resin surface is overheated by the hot plate, and the curing proceeds on the epoxy resin surface, so that the epoxy on the surface of the connecting portion 2c and the surface of the tip portion 52a. The affinity with the resin may decrease, and the airtightness between the cells 31 may be impaired. In order to avoid such a phenomenon, an epoxy resin whose curing proceeds slowly is used. However, since the curing time becomes long, productivity is lowered.

  In order to avoid problems such as the above-described variations in the thermal welding strength, contamination of the hot plate surface due to the sealant 60, or heating of the sealant by the hot plate, the present invention In the thermal welding with the bottom lid 59, the following configuration can be preferably employed. That is, as shown in FIG. 5, a protrusion 51 b as a heat welding margin is formed at the lowermost part of the outer wall 51 a constituting the outer periphery of the battery case 51.

  Further, the bottom cover 59 is provided with a groove 59a corresponding to the protrusion 51b. A heating element 61 that generates Joule heat when energized is disposed in the groove 59a. The heating element 61 generates heat when energized, and pressurizes while melting the resin around the heating element uniformly. The bottom lid 59 can be welded uniformly with high welding strength.

  According to such heat welding using the heating element 61, a process of pressing the hot plate with the sealing agent 60 against the sealing agent pot 59b becomes unnecessary. It is more preferable that the contamination of the hot plate surface or the trouble caused by heating the sealing agent 60 by the hot plate can be avoided.

  As the heating element 61, an iron wire or a stainless steel wire is used, and the iron wire or the stainless steel wire may be energized to generate heat. In order to supply current to the heating element 61, both ends of the heating element 61 are exposed to the outside of the bottom cover 59, and an energization terminal derived from a separately supplied energizing power source is brought into contact with the exposed portion of the heating element 61 to energize the heating element 61. A welding current may be supplied from the power source to the heating element 61.

  Furthermore, as a preferred embodiment, the heating element 61 can be heated by high frequency induction heating without exposing the heating element 61 from the bottom cover 59. A heating coil (not shown) may be disposed at a position close to the bottom cover 59, and an alternating current may be supplied to the heating coil from a high frequency power source. Due to the magnetic field generated by the heating coil, an eddy current is generated in the heating element 61, the heating element 61 generates heat based on the electrical resistance and eddy current of the heating element 61, and the battery case 51 and the bottom lid 59 are thermally welded. be able to.

  According to the high frequency induction heating, since the heating element 61 can be heated in a non-contact manner, it is not necessary to expose the heating element 61 from the bottom cover 59 as compared with the case where current is directly supplied to the heating element 61. The structure of the lid 59 can be made simpler.

  In addition, when current is supplied by bringing a current-carrying terminal into contact with the exposed portion of the heating element 61, there are cases where the contact resistance between the heating element 61 and the current-carrying terminal increases. When the heat generation becomes large and the periphery of the contact part is excessively melted and the bottom cover 59 is damaged or the connection between the heating element 61 and the energizing terminal is disconnected, the battery case 51 and the bottom cover 59 are not welded. It may be in a state.

  According to the high frequency induction heating, there is no need to bring the current-carrying terminal into contact with the heating element 61. Therefore, there is no influence of variations in the contact state between the heat-generating element 61 and the current-carrying terminal. The heat welding strength can be obtained.

  When the heating element 61 is heated by high-frequency induction heating, the use of a ferromagnetic iron wire or nickel wire as the heating element 61 has high heat generation efficiency. preferable.

  In the example shown in FIG. 5, the configuration in which the heating element 61 is disposed on the bottom lid 59 side is described. However, the groove 59a is provided on the outer wall 51a side of the battery case 51, and the heating element 61 is disposed therein. May be. In this case, the bottom cover 59 is provided with a protrusion 51b that fits into the groove 59a.

  According to the present invention, there is provided a lead storage battery excellent in reliability in which the airtightness and liquid tightness between the connecting portion 2c functioning as an intercell connection and the cell chamber 53 adjacent to each other via the connecting portion 2c are remarkably improved. Obtainable. Further, the connection part 2c does not require an airtight holding collar as shown in Patent Document 1, and in particular has the effect of reducing the number of manufacturing steps.

  In addition, according to a more preferable configuration of the present invention, variation in the welding strength between the battery case 51 and the bottom lid 59 is reduced by using the heating element 61 as a heat source for heat welding. In addition, it is possible to avoid problems caused by heat sealing using the conventional hot plate as described above, contamination of the hot plate surface by the sealant 60, or heating of the sealant 60 by the hot plate. .

  The lead storage battery of the present invention can be applied to either an open liquid type or a control valve type lead storage battery. FIG. 4 does not show an exhaust structure in an open liquid lead-acid battery and a control valve structure in a control valve-type lead-acid battery. For example, it may be arranged on the top surface of the battery case 51.

  According to the present invention, in a lead storage battery using an electrode plate unit in which a positive electrode plate and a negative electrode plate are integrated, it is possible to remarkably improve the air tightness and liquid tightness of the inter-cell connecting portion, and particularly high output power. For the first time, it can be applied to lead storage batteries for various purposes.

Diagram showing the electrode plate unit (A) The figure which shows the manufacturing process of a series electrode group. (B) The figure which shows the manufacturing process of a series electrode group. (C) The figure which shows the manufacturing process of a series plate group. (A) Other figure which shows manufacturing process of series electrode group, (b) Other figure which shows the manufacturing process of series electrode group Diagram showing series plate group Sectional drawing which shows the lead acid battery of this invention Sectional drawing which shows the fitting state of a battery case and a bottom cover

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lead storage battery 2 Electrode plate unit 2c Connection part 2a Positive electrode plate part 2b Negative electrode plate part 3 Positive electrode plate 3a Positive electrode current collection ear 4 Negative electrode plate 4a Negative electrode current collection ear 5 Separator 31, 31 'Cell 32, 32' Series electrode plate group 51 Battery case 51a Outer wall 51b Protrusion 52 Bulkhead 52a Tip 53 Cell chamber 54 Positive electrode shelf 55 Positive electrode terminal 55 ′ Negative electrode terminal 56 Positive electrode column 57 Negative electrode shelf 58 Negative electrode column 59 Bottom lid 59a Groove 59b Sealant pot 59c Pot wall 60 Sealing Agent 61 Heating element 62 Bushing

Claims (3)

A lead-acid battery in which a plurality of cells are connected in series at a connection part between cells,
Each of the cells is formed by laminating the same number of positive and negative electrode plates with a separator interposed therebetween,
The cell is housed in a cell chamber partitioned by a partition wall in the battery case,
An electrode in which each positive electrode plate housed in one cell chamber adjacent to each other via the partition wall and each negative electrode plate housed in the other cell chamber are electrically connected via a connecting portion. With a plate unit,
The battery case has an opening, a bottom cover is attached to the opening, and the bottom cover has a sealant pot for storing the tip of the partition and the connection part, and the sealing A lead-acid battery in which a connection part between cells is sealed by filling a sealing agent in a stopper pot. At the joint between the battery case and the bottom cover, a protrusion provided on one outer periphery of the battery case and the bottom cover fits into a groove provided on the other outer periphery and is accommodated in the groove. The lead acid battery according to claim 1, wherein the battery case and the bottom cover are thermally welded by causing the heating element to generate heat to melt the protrusion and the groove. The lead storage battery according to claim 2, wherein the heating element is disposed so as not to be exposed to the outside of the battery, and the battery case and the bottom cover are joined by causing the heating element to generate heat by high frequency induction heating.

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