JP2012160354A - Control valve type lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control valve type lead-acid battery having improved life characteristics by making the working pressure of a valve constant without being affected by fine structural change, e.g. contact state of an exhaust port and the rubber plate of a control valve or adhesion amount of silicon oil.SOLUTION: An electrode plate group and an electrolytic solution are housed, respectively, in a plurality of cell chambers provided in a battery container and the plurality of cell chambers are connected in series. Upper part of the battery container is covered with a lid having exhaust ports at positions directly above respective cell chambers. Each exhaust port is sealed by a control valve consisting of a rubber plate, a cushion material mounted on the rubber plate, and a retainer plate which presses and fixes the cushion material. In such a control valve type lead-acid battery, the cushion material is pressed and fixed by a retainer plate where the thickness at a portion corresponding a part of the periphery of the exhaust port is reduced when compared with that at other positions.

Description

  The present invention relates to a valve-regulated lead-acid battery.

  When the control valve type lead-acid battery is charged, oxygen gas is generated from the positive electrode by electrolyzing water in the electrolytic solution, in addition to the reaction of charging the active material of the positive electrode and the negative electrode. The generated oxygen gas is absorbed and reacted with spongy lead, which is the active material of the negative electrode, and has a function of reducing the amount of gas generated from the negative electrode when the negative electrode is partially uncharged. Therefore, when the charging voltage is low, gas is not easily released to the outside of the battery. However, practically, since the charging current is increased in order to shorten the charging time, a relatively high charging voltage is often employed in consideration of polarization. Then, not all oxygen gas and hydrogen gas are consumed inside the battery, and the internal pressure of the battery rises due to the generated gas. However, when the battery internal pressure rises, the internal pressure of the battery is suppressed from rising by releasing the gas inside the battery through the control valve.

  Further, the control valve has a function of preventing oxygen from entering from the outside of the battery. If the inside of the battery communicates with the outside after charging, the negative electrode absorbs not only oxygen inside the battery but also oxygen in the atmosphere and deteriorates. Although the control valve has solved this problem, if the control valve type lead-acid battery is left unattended, the negative electrode absorbs oxygen inside the battery without communicating with the atmosphere, so the inside of the battery may be in a decompressed state. is there.

  An internal perspective view of the control valve type lead storage battery is shown in FIG. An electrode group g (consisting of a positive electrode d, a negative electrode plate e, and a separator f) and an electrolytic solution are accommodated in each cell chamber of a battery case a provided with a plurality of cell chambers and connected in series. One side is connected to the terminal c), the upper side of the battery case a is covered with a lid b provided with an exhaust port at a position directly above each cell chamber, and the exhaust port is connected to the control valve h. And a control valve type lead-acid battery is configured by taking the terminal c out of the lid b. Note that silicon oil or the like is interposed at the interface around the exhaust port of the control valve h and the lid b, so that the sealed state inside the battery is firmly maintained.

  An example of the structure of a conventional control valve h is shown in FIG. A control valve configured by placing a cushion material 3 made of foam of ethylene propylene rubber (EPDM) on a rubber plate 2 made of chloroprene rubber or the like, and pressing and fixing the cushion material 3 with a press plate 4. h seals the exhaust port 1. The press plate 4 presses and fixes the cushion material 3 so that the inside of the battery is normally cut off from the outside. When charging, oxygen gas and hydrogen gas are generated, and when the internal pressure of the battery rises and reaches the valve operating pressure, the rubber plate 2 is lifted off from the periphery of the exhaust port 1, and the gas inside the battery is released. The When the internal pressure of the battery falls below the valve operating pressure by releasing these gases, the rubber plate 2 comes into close contact with the exhaust port 1 by pressing the cushion material 3, and the inside of the battery is sealed again.

  However, if the force with which the cushion material 3 presses the rubber plate 2 is not constant, the valve operating pressure actually varies even if the valve operating pressure of the control valve h is set to be constant. Here, when the valve operating pressure of the control valve h is high, since a large amount of oxygen gas is absorbed by the negative electrode, the state of charge of the negative electrode becomes low. Conversely, when the valve operating pressure of the control valve h is low, the oxygen gas absorbed by the negative electrode is reduced, and the charged state of the negative electrode is increased. That is, when the control valve type lead storage battery is configured by connecting the cell chambers in series in a state where the valve operating pressure of the control valve h varies, the charged state of each cell chamber is not constant. If it does so, a cell room with a low charge state will be over-discharged, and will cause a short life. Furthermore, shortening the service life is accelerated by repeating charging and discharging while the state of charge is low.

  In Patent Document 1, as shown in FIG. 4, a plurality of protrusions t having a diameter of about 1 mm whose tip is a curved surface are formed annularly on the presser plate 4 installed above the rubber plate 2 at appropriate intervals. A configuration is described in which the periphery of the exhaust port 1 is fixed by pushing the tip of the projection t into the rubber plate 2 so as to bite into the rubber plate 2 by about 0.2 mm. With this configuration, the rubber plate 2 is fixed around the exhaust port 1 by the protrusion t. Therefore, the rubber plate 2 is not sucked into the exhaust port 1 by strong decompression, and the rubber plate 2 is vibrated by vibration or impact. Therefore, it is considered that the airtightness inside the battery can be stably maintained. By combining this configuration with the conventional configuration shown in FIGS. 5 and 6, it is considered that a control valve type lead-acid battery that always shows a stable valve operating pressure as set and has a constant state of charge between cell chambers can be provided. It is done.

JP-A-63-310554

  However, even if the force with which the cushion material 3 presses the rubber plate 2 is constant, the portion where the rubber plate 2 first begins to peel from the periphery of the exhaust port 1 immediately after the internal pressure of the battery reaches the valve operating pressure Since it is influenced by the contact state between the port 1 and the rubber plate 2 (due to the surface roughness of the lid b around the exhaust port 1, the presence or absence and depth of the flaw), and the amount of silicon oil attached, The internal pressure of the battery at the time of starting differs for each exhaust port 1 (that is, for each cell chamber). In addition, since the contact state between the exhaust port 1 and the rubber plate 2 and the amount of silicon oil attached change each time exhaust occurs, the valve operating pressure of the control valve h changes each time. As a result, the state of charge for each cell chamber is not constant, and the short life is not fundamentally improved.

  The present invention is intended to solve this problem, and the valve operating pressure is not affected by a minute structural change such as the contact state between the exhaust port 1 and the rubber plate 2 of the control valve h or the amount of silicon oil attached. It is an object of the present invention to provide a control valve type lead-acid battery whose life characteristics are improved by making the battery constant.

  In order to solve the above-described problem, the invention according to claim 1 of the present invention is configured such that an electrode plate group and an electrolytic solution are accommodated in each cell chamber of a battery case provided with a plurality of cell chambers and connected in series. The upper part of the battery case is covered with a lid provided with an exhaust port at a position corresponding to the position directly above each cell chamber, and each exhaust port is covered with a rubber plate and a cushion material placed on the rubber plate, It is a control valve type lead-acid battery sealed with a control valve consisting of a presser plate that presses and fixes the cushioning material, and the presser plate whose thickness corresponding to a part of the periphery of the exhaust port is made smaller than other parts, The cushioning material is pressed and fixed.

  In the invention according to claim 2 of the present invention, the electrode plate group and the electrolytic solution are accommodated in each cell chamber of the battery case provided with a plurality of cell chambers, connected in series, and directly above each cell chamber. Cover the upper part of the battery case with a lid provided with an exhaust port at the corresponding position, and press the rubber plate, the cushion material placed on the rubber plate, and the presser that presses and fixes the cushion material to each exhaust port. It is a control valve type lead-acid battery sealed with a control valve consisting of a plate, and a cushioning material whose density corresponding to a part of the periphery of the exhaust port is made smaller than other parts is pressed and fixed with a presser plate. Features.

  As a result of the inventor's investigation, there are fine structural changes such as the contact state between the exhaust port 1 and the rubber plate 2 and the amount of silicon oil attached by selectively providing a portion where the pressing force of the rubber plate 2 is reduced. Even in this case, it has been found that immediately after the internal pressure of the battery reaches the valve operating pressure, it is possible to stabilize the portion where the rubber plate 2 first begins to peel from the periphery of the exhaust port 1 and the degree of peeling. The present invention utilizes this knowledge, and can be embodied as the following two aspects.

  The first mode is to press and fix the cushion material 3 by the presser plate 4 in which the thickness of the part corresponding to a part of the periphery of the exhaust port 1 is smaller than that of the other part. Since the force that presses the cushion material 3 is small in the portion where the presser plate 4 is thin, the force that presses the rubber plate 2 immediately below it is also small. Therefore, immediately after the internal pressure of the battery reaches the valve operating pressure, it starts to peel from the vicinity of the exhaust port 1 from this vicinity of the rubber plate 2 first.

  The second mode is to press and fix the cushion material 3 with the density of the part corresponding to a part of the periphery of the exhaust port 1 smaller than that of the other part by the presser plate 4. Since the portion where the density of the cushion material 3 is small is deformed in the thickness direction by the force pressed by the presser plate 4, the force pressing the rubber plate 2 immediately below it is also reduced. Therefore, immediately after the internal pressure of the battery reaches the valve operating pressure, it starts to peel from the vicinity of the exhaust port 1 from this vicinity of the rubber plate 2 first.

  Here, even if the first aspect and the second aspect are combined, the effect of the present invention is exhibited.

  According to the configuration of the present invention, the valve operating pressure can be made constant without being affected by a minute structural change such as the contact state between the exhaust port 1 and the rubber plate 2 of the control valve h or the amount of silicon oil attached. Therefore, it becomes possible to provide a control valve type lead storage battery with improved life characteristics.

Sectional drawing which shows the one aspect | mode of the control valve of the control valve type lead acid battery of this invention Sectional drawing which shows the other aspect of the control valve of the control valve type lead acid battery of this invention. Sectional drawing which shows the other aspect of the control valve of the control valve type lead acid battery of this invention. Sectional drawing which shows the aspect of the control valve of the control valve type lead acid battery of patent document 1 Internal perspective view of control valve type lead acid battery Sectional drawing which shows the aspect of the control valve of the conventional control valve type lead acid battery The figure showing transition of the discharge time in an Example The figure showing transition of valve operation pressure in an example

  The basic structure of the control valve type lead storage battery of the present invention is as shown in FIG. 5 and uses a lid provided with an exhaust port 1 at a position corresponding to the position directly above the cell chamber. Here, the embodiment will be described in detail with a focus on the control valve which is the main part of the present invention.

  FIG. 1 is a cross-sectional view showing one embodiment of a control valve of a control valve type lead storage battery of the present invention. The exhaust port 1 is sealed with a control valve including a rubber plate 2, a cushion material 3 placed on the rubber plate 2, and a presser plate 4 that presses and fixes the cushion material 3. Here, the holding plate 4 has a portion corresponding to a part of the periphery of the exhaust port 1 having a smaller thickness than other portions. Since the force that presses the cushion material 3 is small in the portion where the presser plate 4 is thin, the force that presses the rubber plate 2 immediately below it is also small. Therefore, immediately after the internal pressure reaches the valve operating pressure, it starts to peel from the vicinity of the exhaust port 1 from this vicinity of the rubber plate 2 first.

  FIG. 2 is a cross-sectional view showing another embodiment of the control valve of the control valve type lead storage battery of the present invention. The exhaust port 1 is sealed with a control valve including a rubber plate 2, a cushion material 3 placed on the rubber plate 2, and a presser plate 4 that presses and fixes the cushion material 3. Here, the density of the portion of the cushion material 3 corresponding to a part of the periphery of the exhaust port 1 is smaller than that of other portions. Since the portion where the density of the cushion material 3 is small is deformed in the thickness direction by the force pressed by the presser plate 4, the force pressing the rubber plate 2 immediately below it is also reduced. Therefore, immediately after the internal pressure reaches the valve operating pressure, it starts to peel from the vicinity of the exhaust port 1 from this vicinity of the rubber plate 2 first.

  As shown in FIGS. 1 and 2, if the degree of peeling is stabilized by deliberately fixing the part where the rubber plate 2 starts to peel from the periphery of the exhaust port 1 first, the exhaust port 1 and the rubber plate 2 Even if there is a fine structure difference such as the contact state of silicon and the amount of silicon oil attached, the internal pressure at the time when gas release starts can be made uniform, so that the charge state of each cell chamber becomes uniform, The life of the control valve type lead-acid battery can be extended.

  Further, as shown in FIG. 3, even if the features of FIGS. 1 and 2 are combined, the above-described effects of the present invention are exhibited.

  Here, chloroprene rubber or the like can be used for the rubber plate 2. The cushion material 3 may be a foam of ethylene propylene rubber (EPDM). Further, the presser plate 4 can be made of a material such as acrylonitrile-butadiene-styrene copolymer synthetic resin (ABS).

  Hereinafter, the effects of the present invention will be described with reference to examples.

(Test battery A)
A positive electrode plate d was prepared by appropriately mixing lead powder and red lead, and applying and drying a positive electrode paste kneaded with sulfuric acid on a grid made of a lead alloy. On the other hand, a negative electrode plate e was prepared by appropriately mixing lead powder, lead sulfate, and lignin compound, and applying and drying a negative electrode paste kneaded with sulfuric acid on a lattice made of a lead alloy. The positive electrode plate d and the negative electrode plate e were opposed to each other with the separator f interposed therebetween, thereby preparing the electrode plate group g.

  The electrode plate group g is accommodated together with an electrolytic solution (not shown) in each cell chamber of a battery case a provided with six cell chambers and connected in series, and is placed in a corresponding position directly above each cell chamber. The upper part of the battery case a is covered with a lid b provided with an exhaust port 1, and each exhaust port 1 is pressed against a rubber plate 2, a cushion material 3 placed on the rubber plate 2, and the cushion material 3. A 12V 7.2 Ah control valve type lead-acid battery was constructed by sealing with a control valve h comprising a holding plate 4 to be fixed and taking out the terminal c outside the lid b. In order to keep the inside of the cell chamber tightly, silicon oil was applied to the interface around the exhaust port of the control valve h and the lid b.

Here, the control valve h has the structure shown in FIG. Specifically, on a rubber plate 2 (thickness 0.5 mm) made of chloroprene rubber, a cushion material 3 (thickness 3 mm, apparent density 110 kg / m ³ , 25% compression stress 5 kPa) made of EPDM foam. The cushion material 3 was pressed and fixed with a presser plate 4 made of a tapered ABS whose thickness was changed from 0.6 mm to 1.4 mm. As a result, the thickness of the cushion material 3 pressed to a thick portion (thickness 1.4 mm) of the presser plate 4 is 0.8 mm, and the cushion material pressed to a thin portion (thickness 0.6 mm) of the presser plate 4. The thickness of 3 was 1.6 mm. This is designated as test battery A.

(Test battery B)
For the test battery A, a control valve type lead-acid battery was constructed in the same manner as in FIG. 1 except that the control valve h had the structure shown in FIG. Specifically, on the rubber plate 2 (thickness 0.5 mm) made of chloroprene rubber, the apparent density continuously changes from 90 kg / m ³ to 120 kg / m ³ (25% compressive stress from 4 kPa to 6 kPa). The cushion material 3 (thickness 3 mm) made of the foam made of EPDM was placed, and the cushion material 3 was pressed and fixed by a pressing plate 4 (thickness 1 mm) made of ABS. As a result, the thickness of the cushion material 3 was 1.2 mm. This is designated as test battery B.

(Test battery C)
For the test battery A, a control valve type lead-acid battery was constructed in the same manner as in FIG. 1 except that the control valve h had the structure shown in FIG. Specifically, on a rubber plate 2 (thickness 0.5 mm) made of chloroprene rubber, the apparent density is 95 kg / m ³ to 115 kg / m ³ (25% compression stress is 4.5 kPa to 5.5 kPa). A cushioning ABS 3 (thickness 3 mm) made of a foam made of EPDM which is continuously changed is placed, and this cushioning material 3 is a tapered ABS whose thickness is changed from 0.8 mm to 1.2 mm. The presser plate 4 made of The low density portion (95 kg / m ³ ) of the cushion material 3 is pressed by the thin portion (0.8 mm) of the presser plate 4, and the high density portion (115 kg / m ³ ) of the presser plate 4 is pressed by the press plate 4. Pressing at a thick spot (1.2 mm). As a result, the thickness of the cushion material 3 pressed against the thick portion (thickness 1.2 mm) of the presser plate 4 is 1.0 mm, and the cushion material pressed against the thin portion (thickness 0.8 mm) of the presser plate 4. The thickness of 3 was 1.4 mm. This is designated as test battery C.

(Test battery D)
For the test battery A, a control valve type lead-acid battery was constructed in the same manner as in FIG. 1 except that the control valve h had the structure shown in FIG. Specifically, a cushion material 3 (thickness 3 mm, apparent density 110 kg / m ³ , 25% compression stress 5 kPa) made of EPDM foam on a rubber plate 2 (thickness 0.5 mm) made of chloroprene rubber. The cushion material 3 was pressed and fixed with a pressing plate 4 (thickness 1 mm) made of ABS. As a result, the thickness of the cushion material 3 was 1.2 mm. This is designated as test battery D.

For each one of these test batteries, CC-CV charging (total charging time 8 hours) that attenuates the charging current with 14.7V constant after being charged to 14.7V at 2.9A
A constant current discharge of 1.8 A (end voltage 10.5 V) was performed. With this charging / discharging as one cycle, the discharge capacity and the valve operating pressure in each cell chamber were measured every 25 cycles. The test was terminated when the discharge time of the test battery fell below 50% of the initial discharge time. FIG. 7 shows changes in discharge time, and FIG. 8 shows changes in valve operating pressure in each cell chamber.

  From FIG. 7, compared with the conventional control valve type lead acid battery (test battery D), the control valve type lead acid battery (test batteries A, B, C) of the present invention had a long life.

  In the control valve type lead-acid battery of the present invention, the part where the rubber plate 2 begins to peel from the periphery of the exhaust port 1 is dared to be constant (in the case of the test battery A, the thin part of the presser plate 4, the case of the test battery B) Is a place where the apparent density of the cushion material 3 is low, and in the case of the test battery C, the pressure plate 4 is thin and the apparent density of the cushion material 3 is low), so that the degree of peeling can be stabilized. Even if there is a difference in the fine structure such as the contact state between the rubber plate 1 and the rubber plate 2 or the amount of silicon oil attached, the internal pressure at the time when gas discharge starts can be made uniform. Therefore, as shown in FIG. 8, in the control valve type lead storage battery of the present invention, the measured value of the valve operating pressure for each cell chamber becomes substantially constant even after repeated charging and discharging, and as a result, the state of charge for each cell chamber is aligned. Therefore, it is considered that the life could be extended as shown in FIG.

  Since the present invention can be used in a control valve type lead storage battery and its use is not limited, it has a wide range of industrial applicability.

DESCRIPTION OF SYMBOLS 1 Exhaust port 2 Rubber plate 3 Cushion material 4 Holding plate a Battery case b Lid c Terminal d Positive electrode plate e Negative electrode plate f Separator g Electrode plate group h Control valve t Protrusion

Claims (2)

The electrode plate group and the electrolyte solution are accommodated in each cell chamber of the battery case provided with a plurality of cell chambers, connected in series, and a lid provided with an exhaust port at a position directly above each cell chamber. Control valve type that covers the upper part of the battery case and seals each exhaust port with a control valve consisting of a rubber plate, a cushion material placed on the rubber plate, and a presser plate that presses and fixes the cushion material A lead acid battery,
A control valve type lead-acid battery, wherein the cushion material is pressed and fixed by the presser plate having a thickness corresponding to a part of the periphery of the exhaust port smaller than that of the other part. The electrode plate group and the electrolyte solution are accommodated in each cell chamber of the battery case provided with a plurality of cell chambers, connected in series, and a lid provided with an exhaust port at a position directly above each cell chamber. Control valve type that covers the upper part of the battery case and seals each exhaust port with a control valve consisting of a rubber plate, a cushion material placed on the rubber plate, and a presser plate that presses and fixes the cushion material A lead acid battery,
A control valve type lead-acid battery, wherein the cushion material, in which the density of a part corresponding to a part of the periphery of the exhaust port is made smaller than other parts, is pressed and fixed by the pressing plate.

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