JP2011090861A - Lead-acid storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems that, when an internal ignition is caused to hydrogen gas staying inside a lead-acid storage battery, a battery case and a lid are damaged, an electrolyte solution is scattered, and broken fragments are dispersed. <P>SOLUTION: In a lead-acid storage battery having a battery case with an opening housing a positive electrode plate, a negative electrode plate, a separator, and an electrolyte solution, a region which has a smaller impact resistance than the other portions of the battery case and is closed is formed at an upper position than the electrolyte surface of the battery case wall. By this, when there happens an internal ignition, only this region is damaged, and damage of the battery and scattering of the fragments and electrolyte solution and flowing out of the electrolyte solution can be suppressed notably. Furthermore, more desirably, by installing a cover member to cover this region on the battery, the above effect can be obtained more notably. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lead-acid battery.

  A lead storage battery generates hydrogen gas and oxygen gas by electrolysis of water in dilute sulfuric acid electrolyte during charging. These gases are gradually released from the inside of the lead storage battery into the atmosphere through a gas discharge port provided in the lead storage battery over time. However, depending on the elapsed time since charging, gas may stay in the internal space of the battery, and these gases may ignite any ignition source. Such flammability emits only a small sound and may not affect the battery structure itself or the subsequent battery use, but in some cases, the lid or battery case constituting the battery exterior may be deformed, Furthermore, these may be damaged and the battery may become unusable.

  On the other hand, there are various possible ignition sources for gas, but they are roughly classified into two types. One of them is a source of ignition that occurs inside the battery, which can be caused by discharge sparks caused by static electricity entering from the outside of the battery, or by internal short circuit between the positive electrode plate and the negative electrode plate, fusing or disconnection of the current path during current conduction. The generated discharge spark may ignite the gas staying inside the battery. The other is when there is an ignition source outside the battery.For example, discharge sparks caused by poor connection between the terminal and harness, cigarette fire, discharge sparks due to static electricity charged on the battery exterior are drawn into the battery. This is the case when igniting gas.

  Various studies have been made so far in order to suppress debris of the battery outer case and scattering of the electrolyte solution inside the battery, which are generated when the battery outer case is damaged by the internal ignition of the battery due to various factors as described above. It was.

  For example, in Patent Document 1, when a thin U-shaped or U-shaped thin part is provided on the inner surface of a lid of a lead-acid battery and gas is ignited inside the battery, the thin part is cracked. It has been shown to suppress the scattering of lids, battery case debris, and electrolyte by generating.

  Japanese Patent Application Laid-Open No. H10-228561 discloses that the scattering of battery fragments is suppressed by covering the upper part of the battery with a net.

  Further, Patent Document 3 shows a configuration in which a flap that is cleaved in a U shape by the impact of the internal ignition of the battery is provided, and the electrolyte that is ejected from the cleaved portion to the outside of the battery is blocked by a drooping plate that hangs from the lid. ing.

Japanese Utility Model Publication No. 63-135760 Japanese Utility Model Publication No. 4-55756 U.S. Pat. No. 4,250,232 JP-A-5-299124 JP-A-9-129273

  According to the configuration of Patent Document 1 described above, the thin wall portion provided on the lid is damaged during gas ignition inside the battery. For example, when the lead storage battery is inspected in a state where the lead storage battery is mounted on the vehicle, or when the lead storage battery is removed from the vehicle and supplementary charging is performed, the work is performed with a sufficient space above the lead storage battery. In such a state, when the internal ignition of the lead storage battery occurs and the lid is damaged, the fragments and electrolyte of the lid will scatter upward, so it will be scattered compared to the case where the battery is scattered laterally. There is a problem of expanding the scope.

  Moreover, in the structure of patent document 2, scattering of electrolyte solution when a battery exterior is damaged cannot be suppressed.

  In the configuration of Patent Document 3, the flap provided on the side surface of the battery case is cleaved in a U shape, but the degree of opening of the cleaved flap is limited by the drooping plate, which is sufficient to mitigate the impact at the time of internal ignition Instead, damage due to stress concentration occurred in the vicinity of the joint between the battery case and the lid, which is the base of the flap, and the battery case, cover fragments and electrolyte solution may be scattered outside.

  On the other hand, the case where the U-shaped flap in patent document 3 is arrange | positioned in reverse U shape can be considered. In this case, the flap is split into an inverted U shape due to the impact at the time of internal ignition. However, when the impact is excessive, damage to the battery case proceeds further from the base of the flap toward the bottom of the battery case, and a large amount of electrolyte flows out. As a result, there has been a problem that damage caused by corrosion of vehicles and equipment equipped with lead-acid batteries is increased.

  The present invention is a liquid type lead-acid battery that suppresses the scattering and outflow of the lead-acid battery exterior debris and electrolyte even if internal ignition occurs by damaging a specific part of the battery case. The present invention provides a lead-acid battery excellent in reliability with suppressed upward scattering.

  In order to solve the above problems, the invention according to claim 1 of the present invention is to close a battery case having a positive electrode plate, a negative electrode plate, a separator, and a cell chamber containing an electrolyte, and an opening of the battery case, And a lead storage battery having a lid with a terminal formed on the surface thereof, having an electrolytic solution in the battery case, being above the liquid level of the electrolytic solution on the outer wall of the battery case, and A first region that is lower in impact resistance than the other part of the outer wall of the battery case and is closed on the surface of the outer wall, at least at a part below the joint between the lid and the battery case The lead storage battery is characterized in that the impact resistance of the first region is lower than the impact resistance of the lid and the impact resistance of the joint.

  According to the configuration of the first aspect, the impact on the battery internal ignition causes damage at a site on the electrolyte surface of the battery case, so that scattering of the electrolyte solution and fragments of the battery exterior toward the upper side of the battery is suppressed. Is done. Moreover, since damage occurs above the electrolytic solution surface, the outflow of the electrolytic solution to the outside can be suppressed.

  The invention according to claim 2 of the present invention is the lead-acid battery having the configuration of claim 1, wherein the Izod impact value of the first region is Izx, and the first region is excluded from the outer wall of the battery case (Iz1-Izx), (Iz2-Izx), and (Iz3-Izx) are respectively expressed as Iz impact value of Iz1, Iz impact value of the lid is Iz2, and Iz impact value of the joint is Iz3. It is characterized by being 20 J / m or more.

  Moreover, the invention which concerns on Claim 3 of this invention is a lead acid battery which has the structure of Claims 1-2, In the outer wall of the said battery case, The said 1st area | region and the said 1st area | region of the said battery case The parts excluding are made of different materials.

  According to a fourth aspect of the present invention, in the lead-acid battery having the configuration according to the first to third aspects, the first region is covered with a cover member.

  The invention according to claim 5 of the present invention is the lead storage battery having the configuration of claim 4, wherein the cover member is made of a material having gas permeability.

  According to a sixth aspect of the present invention, in the lead storage battery having the configuration of the fifth aspect, the cover member and the first region are joined to each other with an adhesive.

  According to a seventh aspect of the present invention, in the lead storage battery having the configuration of the fifth to sixth aspects, the cover member is made of a non-woven mat, a woven fabric, a porous body, or a layered body thereof. It is characterized by.

  And the invention which concerns on Claim 8 of this invention is a lead acid battery which has the structure of Claims 4-7, WHEREIN: The said cover member covers the said cover of the said cover member while covering at least one part of the said cover. The part shows a lead storage battery in which a model number of the lead storage battery, a wording indicating usage precautions, a symbol, a design or the like is formed.

  And the invention which concerns on Claim 9 of this invention WHEREIN: In the lead acid battery of Claims 1-8, it had electrolyte surface upper limit position display means, such as a liquid surface upper limit line provided in the said battery case. Features.

  According to the present invention, in the liquid type lead-acid battery, by damaging a specific part of the battery case, scattering of the electrolyte from the lead-acid battery during internal ignition and a large amount of electrolyte Suppresses outflow. In addition, by suppressing the scattering of the lead storage battery exterior, particularly upward of the battery, there is a remarkable effect that it is possible to provide a lead storage battery that is safer for the operator.

(A) The figure which shows the top | upper surface of the lead acid battery by the 1st Embodiment of this invention (b) The figure which shows the side surface of the lead acid battery by the 1st Embodiment of this invention The figure which shows the lead acid battery by the 2nd Embodiment of this invention. The figure which shows the lead acid battery by the 3rd Embodiment of this invention. (A) The figure which shows the top | upper surface of the lead acid battery by the 4th Embodiment of this invention (b) The figure which shows the side surface of the lead acid battery by the 4th Embodiment of this invention The figure which shows the lead acid battery by the 5th Embodiment of this invention. The figure which shows the lead acid battery by the 6th Embodiment of this invention. The figure which shows the lead acid battery of the comparative example The figure which shows the lead acid battery of another comparative example

  Hereinafter, the configuration of a lead storage battery according to an embodiment of the present invention will be described with reference to the drawings. In addition, although each embodiment of this invention described the example which applied this invention to the 12V lead acid battery for engine starting in which the 2V cell was connected in series inside the battery, the cell which comprises the lead acid battery of this invention was described. The number and arrangement are examples, and should be appropriately determined according to the desired voltage and shape, and such variations such as the number of cells, cell connection form, or cell arrangement also constitute the configuration of the present invention. As long as it has, it is included in the scope of the present invention.

  Further, in the lead storage battery according to each embodiment of the present invention to be described later, the battery case and the lid to be described later both describe an example using a polypyropylene-polyethylene copolymer mainly composed of polypropylene. The present invention can also be applied to examples using other resins used for battery cases and exteriors, such as ABS resin, PS resin, PPE resin, and the like. Furthermore, the impact resistance of each of these resins depends on the properties of the filler added to the resin (fibrous, powdery) and the amount added, and in the case of a copolymer, depending on the ratio of the respective resin components. It is possible to adjust sex.

  For example, a polypropylene resin, which is generally used as a battery case and lid material for a lead-acid battery for start-up, is usually a copolymer of propylene and ethylene, and when the ratio of ethylene in the copolymer is increased, Impact properties can be reduced.

  In the present invention, an Izod impact value (Iz impact value) is used as an index of “impact resistance”, but a Charpy impact value may be used as the index. In addition, when a weight with an appropriate shape (spherical, wedge shape, etc.) and mass is dropped on an object whose impact resistance is to be measured, the weight drop height that leads to damage to the object is a measure of impact resistance. It may be used as

In addition, the Iz impact value (unit: J / m) defined by JIS K7110 is used as an index of impact resistance in each embodiment of the present invention and in the claims including the present embodiment example. In JIS K7110, since the width of the measurement object is set, the unit is J / m. In addition, since the thing from which the width | variety of a measuring object differs from a setting value is represented by the work at the time of the damage of a measuring object with respect to the cross-sectional area of a measuring object, a unit becomes J / m < ² >.

(First embodiment of the present invention)
FIG. 1A is a diagram showing a top surface of the lead storage battery 101 according to the first embodiment of the present invention, and FIG. 1B is a diagram showing a side surface of the lead storage battery 101. The exterior of the lead storage battery 101 includes a battery case 102 and a lid 103. In the example shown in the figure, the inside of the battery case 102 is divided into six cell chambers (not shown) by five partition walls (not shown). In each cell chamber, a positive electrode plate, a negative electrode plate, A cell composed of a separator disposed between these electrode plates is accommodated together with a dilute sulfuric acid electrolyte (hereinafter, electrolyte).

  In addition, in description of each embodiment of this invention demonstrated below including this embodiment, it represents with the dashed-two dotted line A in each corresponding figure as a display of the position of a partition.

  The lead storage battery 101 of the present invention preferably includes an electrolyte solution upper limit position display means for indicating the upper limit of the electrolyte to the user. As a specific example of the electrolytic solution surface upper limit position display means, the electrolytic solution surface upper limit line 102a as shown in FIG. 1B is displayed on the battery case 102 by engraving, embossing or printing. In addition, the height position of the electrolyte solution upper limit line 102a is determined in consideration of the capacity of the lead storage battery 101 and the electrolyte leakage during vibration or charging of the lead storage battery 101.

  By setting the electrolyte level upper limit line 102a further upward, particularly the low rate discharge capacity is increased, and the period until the negative electrode strap (not shown) for performing collective welding of the negative electrode plates to each other is longer, preferable. However, on the other hand, when the lead storage battery 101 is vibrated or charged, the electrolyte solution may leak out of the battery through the gas exhaust structure provided in the lid 103. Therefore, the electrolytic solution upper limit line 102a is not different from other lead storage batteries in that the above-mentioned matters should be taken into consideration and the battery capacity should be secured and set at a position where the electrolytic solution does not leak.

  Moreover, you may provide the electrolyte solution level lower limit line 102b which shows the minimum of an electrolyte solution level. The electrolyte level lower limit line 102b is generally set at a position above the upper surface of the negative electrode strap. This is because the negative electrode strap may be corroded when exposed from the electrolytic solution. In addition, although it is preferable to provide the electrolyte solution surface upper limit line 102a, it is not an essential structural requirement of this invention with the electrolyte solution surface lower limit line 102b.

  In the example shown in FIG. 1B, an example in which the electrolyte surface upper limit line 102 a is used as the electrolyte solution surface upper limit position display means is shown, but according to the electrolyte solution surface as shown in Patent Document 4 A storage battery indicator whose display color changes may be used, and a cylindrical well as shown in Patent Document 5 may be formed in the battery inner direction of the lid 103. When the well tip and the electrolyte surface are in contact with each other, a meniscus due to surface tension is generated on the contact surface between the electrolyte and the well tip, and the internal positive electrode plate and negative electrode plate appear to be curved.

  Therefore, if the well tip is set at an appropriate position with respect to the electrolytic solution surface, the relative relationship between the electrolytic solution surface and its upper limit position can be confirmed according to the visibility of the electrode plate group from the well tip. That is, the well can be used as an electrolytic solution surface upper limit position display means. In addition, a configuration that can be easily inferred from known liquid level detection means or known liquid level detection means, such as a type that uses the third electrode for liquid level detection, is used as the electrolyte level upper limit position display means in the present invention. Applicable.

  In the lead storage battery 101, cells are connected (not shown) through the through holes provided in the partition walls, but the cells may be connected by other known methods. Moreover, in the case of the lead acid battery comprised by the single cell, it is obvious that the connection between cells in a battery is not required.

  The lead storage battery 101 of the present invention forms a gas discharge path for discharging the gas in the cell chamber to the atmosphere, similar to the known lead storage battery. As an example, a liquid port 104 corresponding to the cell chamber is formed in the lid 103, and a liquid port plug 105 having a gas discharge path for discharging the gas in the cell chamber to the atmosphere is attached to the liquid port 104. Good. Further, in the present invention, as a form of the gas discharge path, it is possible to adopt another known configuration or a configuration that can be easily inferred from a known configuration.

  The lid 103 is provided with terminals 107 and 107 ', and these terminals 107 and 107' are connected to internal cells by connecting parts such as poles.

  Both the lid 103 and the battery case 102 can be formed of a thermoplastic resin. In that case, the lid 103 and the battery case 102 can be joined by thermal welding. Moreover, you may join the lid | cover 103 and the battery case 102 with an adhesive material.

  The lead storage battery 101 according to the first embodiment of the present invention is located above the electrolyte and at least part of the lower part of the joint 103a between the lid 103 and the battery case 102, in addition to the outer wall of the battery case. The first region X is lower in impact resistance than the portion. In the example shown in FIG. 1 (b), the electrolyte surface upper limit position display means, that is, an example in which the electrolyte solution surface upper limit line 102a is provided, the electrolyte solution surface is at least the electrolyte solution surface upper limit line. It is set below 102a.

  In FIG. 1B, the first region X is a region surrounded by two one-dot chain lines x and y. In the first embodiment, the first region X is provided in a belt shape so as to go around the battery case 102. And a closed ring shape. Further, the present invention is characterized in that the impact resistance of the first region X is lower than the impact resistance of the lid 103 and the impact resistance of the joint portion 103a.

  According to the configuration of the present invention described above, the position above the electrolyte surface of the battery case 102 is preferentially damaged by the impact when igniting the gas accumulated in the battery, so that the electrolysis due to the damage of the battery case 102 is caused. Spattering of the liquid is suppressed. Further, since the breakage of the lid 103 is also suppressed, the broken pieces of the lid 103 or the scattering of the electrolytic solution upward can be suppressed, the scattering range can be suppressed, and the damage due to the scattering can be suppressed.

  The first region X forms a closed region on the outer wall surface of the other battery case 102. When internal ignition occurs in the lead storage battery 101, the first region X is damaged. On the other hand, since the first region X is closed, the damage of the battery case 102 is limited to the first region X, and the spread of the damage to the outside of the first region X is suppressed.

  As a result, the shards of the battery case 102 and the scattering direction of the electrolyte generated by the impact at the time of ignition inside the battery are concentrated not on the battery but on the side of the battery. Moreover, since the damage of the battery case 102 occurs above the electrolytic solution surface upper limit line 102a, the outflow amount of the electrolytic solution from the battery can be suppressed.

  In the present invention, the impact resistance of the first region X is lower than the impact resistance of the portion excluding the first region X of the battery case 102, the lid 103, and the joint 103 a between the battery case 102 and the lid 103. Set. As an index of impact resistance, an Izod impact value (hereinafter, Iz impact value) can be adopted. In addition, as another index of impact resistance, for example, an index generally adopted for synthetic resins such as Charpy impact value can be used.

  As a technique for forming the first region X, for example, the following technique can be used. Since the polypropylene resin, the polyethylene resin, and the copolymer thereof are crystalline resins, impact resistance changes depending on molding conditions. As an example, if the mold temperature during molding is increased, the impact resistance tends to decrease. The impact resistance also changes depending on the cooling rate of the resin after the resin is injected.

  Therefore, the same resin material can be obtained by using a mold in which the mold temperature and the cooling rate of the part corresponding to the outer wall of the first region X of the battery case mold are variable compared to other parts. By using it, it is possible to reduce the impact resistance only in the first region X.

  The above-described mold for forming a battery case can be obtained by appropriately setting the arrangement of the heater for adjusting the mold temperature and the arrangement of the cooling pipe for circulating the cooling water in the mold. The molding conditions for the portion corresponding to the first region X of the outer wall 102 and the molding conditions for the other portions can be varied. For example, by using such a mold for forming a battery case, and changing the temperature and cooling rate of the resin corresponding to the first region X from other parts, the first region X of the battery case 102 The impact resistance can be made lower than the other parts excluding the first region X of the battery case 102.

  The effects of mold temperature and cooling rate on the impact resistance of the resin are prominent in crystalline resins such as polypropylene resin and polyethylene resin, but the degree and tendency differ depending on the type of resin. What is necessary is just to grasp | ascertain the relationship between mold temperature and cooling rate, and Iz impact value with the test piece which changed mold temperature and cooling rate.

  As a method of making the Iz impact value (Izx) of the first region X smaller than the Iz impact value (Iz1) of the portion excluding the first region X of the battery case 102, there are two types of differences in the Iz impact value. A resin may be used, and the portion of the first region X may be a resin having a low Iz impact value by double injection molding, and the other portion may be a resin having a high Iz impact value. The lid 103 may be made of a resin having a high Iz impact value.

The Iz impact value in a polypropylene resin tends to decrease as the amount of additive (SiO ₂ , TiO ₂ ) added to the resin increases, and the Iz impact value can be selected depending on the amount of filler added.

  In addition, when a polyethylene resin is added to a polypropylene resin to form a copolymer of both, the Iz impact value decreases as the amount of the polyethylene resin increases. Therefore, the Iz impact value depends on the amount of the polyethylene resin in the copolymer. Can be selected.

  The Iz impact value (Izx) of the first region X, the Iz impact value (Iz1) of the portion excluding the first region of the battery case 102, the Iz impact value (Iz2) of the lid 103, and the Iz impact value of the joint portion. As (Iz3), for example, Izx can be 90 J / m, and Iz1 to Iz3 can be 120 J / m.

  The difference in impact resistance between Izx and Iz1 is preferably 20 J / m or more. In addition, since Iz1 and Iz2 are equivalent and at least the strength of the joint 103a is ensured, Iz3 ≧ Iz1 and Iz2, so (Iz1-Izx), (Iz2-Izx), and (Iz3-Izx) are respectively set. It is preferable to set it as 20 J / m or more. Due to such an impact resistance relationship, breakage of the lead storage battery at the time of ignition inside the battery is limited to the first region X, and the scattering amount of the electrolyte at the time of breakage is reduced.

  This is because when the difference in Iz impact value is 20 J / m or more, an impact due to ignition occurs, and in the process of increasing the internal pressure, the difference in Iz impact value is less than 20 J / m. The battery case 102 is damaged in the first region X at an earlier stage. Therefore, since the internal pressure of the battery immediately before the breakage is suppressed to a lower level, it is considered that the momentum of the electrolyte solution is reduced and the amount of electrolyte solution is reduced.

  As a method of measuring the Iz impact value (Iz3) of the joint 103a, the relative relationship between Izx of the first region X and the Iz impact value (Iz1) of the battery case 102 and the Iz impact value (Iz2) of the lid 103 is used. Is easy to do. That is, according to the above-mentioned JIS K7110, Izx, Iz1 and Iz2 are measured with a measurement piece having a predetermined width, and the impact resistance value of these three parts and the impact resistance value of the joint 103a are measured by, for example, a falling ball test. If the impact resistance test is performed, the impact resistance test results obtained by the ball drop test at the four locations and the Iz impact values at the three locations can be compared to determine the range of Iz3.

  For example, in the falling ball test, if the impact resistance of the portion excluding the lid 103 and the first region X of the battery case 102 is equal to or greater than the impact resistance of the joint 103a, Izx <Iz1, Iz2 ≦ Iz3. Further, if the impact resistance of the joint 103a in the falling ball test is larger than the first region and is equal to or less than the impact resistance of the lid of the battery case 102 and the lid 103, Izx <Iz3 ≦ Iz1, Iz2. . Since Izx, Iz1 and Iz2 are easily measurable, applying these specific values to the above relationship will determine the range of Iz3.

  For example, a 55D23 type lead acid battery (12V48Ah) defined in JIS D5301 (starting lead acid battery) is specified so that the first region X is not damaged by an impact at the time of handling that does not result from internal ignition such as dropping of the lead acid battery 101. , About 20 kg), the impact resistance of the first region X is preferably 50 J / m or more. The lower limit value of the impact resistance of the first region X is a design matter that should be determined in consideration of the mass of the lead storage battery.

  A representative parameter representing the strength of the battery case and the lid is tensile strength. On the other hand, the inventors of the present invention do not agree with the magnitude of the tensile strength of these members and the damage situation of the battery case or the cover due to the impact when the battery is ignited. It has been found that there is a strong correlation with the impact resistance including the Iz impact value of the material constituting the material.

  That is, when the Iz impact value of the battery case or the lid is lowered, the battery is easily damaged by the impact at the time of ignition inside the battery, and when the Iz impact value is increased, the damage due to the impact is suppressed. On the other hand, the tensile strength and impact resistance of each resin material do not necessarily have a positive correlation, and the inventors of the present invention have a battery case in order to specify the location where the battery is damaged during battery ignition. It is appropriate to specify impact resistance (for example, Iz impact value) instead of specifying the tensile strength of the lid, and the propagation of cracks due to impact at a site where the impact resistance increases stepwise. It is found that can be stopped.

  The present invention has been made based on such newly discovered technical knowledge, and this technical knowledge is also applied to other embodiments of the invention described below.

(Second embodiment of the present invention)
FIG. 2 is a diagram showing a lead storage battery 201 according to the second embodiment of the present invention. The lead storage battery 201 is different in the configuration of the battery case 202 from the battery case 102 used in the lead storage battery 101 according to the first embodiment of the present invention described above, and other configurations are the same as those of the lead storage battery 101. Can be adopted.

  In the lead storage battery 201 according to the second embodiment, as shown in FIG. 2, the first region X straddles a partition wall (part indicated by a two-dot chain line A) that partitions the cell chamber on the side surface 202 c of the battery case 202. , And is formed in a rectangular shape closed by an alternate long and short dash line z. Further, the first region X is arranged so as to correspond to all the cells. The first region X is provided above the electrolyte surface. Similarly to the first embodiment, when the electrolyte solution upper limit position display means is provided, the first region X is set above the electrolyte solution upper limit line 102a in FIG.

  In the present invention, the impact resistance value (Izod impact value) of the portion excluding the first region X of the battery case 202 is Iz1, the impact resistance value (Izod impact value) of the lid 103 is Iz2, and the battery case 202 and the lid 103 are When the impact resistance value (Izod impact value) of the joint 103b is Iz3 and the impact resistance (Izod impact value) of the first region X is Izx, Izx <Iz1, Izx <Iz2, and Ixz <Iz3.

  According to the second embodiment, when the lead storage battery 201 is internally ignited, the first region X is preferentially damaged, thereby preventing other parts from being damaged. As a result, the upward scattering of the electrolytic solution, the battery case 202 and the lid 103 is suppressed, and damage due to the scattering can be minimized.

  As in the first embodiment, also in the second embodiment, (Iz1-Izx), (Iz2-Izx), and (Iz3-Izx) are preferably set to 20 J / m or more. In addition, you may provide the 1st area | region X in 2nd Embodiment on both surfaces of the side surface 202c which has two surfaces. However, in a state where the lead storage battery 201 is mounted on a vehicle or device, the first region X may be provided on the side surface 202c on the side opposite to the side accessed by the lead storage battery 201 or the vehicle and device inspector. it can. According to this, when the lead storage battery 201 is damaged, debris and electrolytic solution are scattered in a direction away from the inspector, which is more preferable.

  The first region X in the second embodiment can be configured with reference to the first embodiment. That is, the first region X surrounded by the alternate long and short dash line z is formed by the double injection method, or the molding conditions of the first region X are different from those of the other parts, and the molding conditions are such that the impact resistance value decreases. Can be achieved.

  In FIG. 2, the first region X is shown in a rectangular shape, but it is preferable that the corner portion Xc has a shape in which two sides such as an R shape smoothly intersect. When the two sides intersect linearly at a certain angle, when the first region X is damaged due to the impact of internal ignition of the lead storage battery 201, stress concentrates on the corner Xc. This is because cracks may occur. In particular, when the crack grows toward the lower side of the battery case, the amount of the electrolyte flowing out increases, so that it is preferable to have a smooth curve that does not concentrate stress on the corner portion Xc.

(Third embodiment of the present invention)
FIG. 3 is a diagram showing a lead storage battery 301 according to the third embodiment of the present invention. The lead storage battery 301 is different in the configuration of the battery case 302 from the battery case 202 used in the lead storage battery 201 according to the second embodiment described above, and other configurations can adopt the same configuration as the lead storage battery 201.

  In the lead storage battery 301 according to the third embodiment, as shown in FIG. 3, the first region X straddles the partition wall (part of the two-dot chain line A) that partitions the cell chamber on the side surface 302 c of the battery case 302. It is provided independently for each cell room so that it does not exist. In the example shown in FIG. 3, it is formed in a rectangular shape closed by a one-dot chain line z ′. Further, as in the second embodiment, the corner portion Xc of the first region X in the present embodiment has a continuous and smooth curved shape such as an R shape. Thereby, even when the 1st area | region X is damaged, the stress concentration of the corner | angular part Xc can be avoided, and generation | occurrence | production of the crack from the corner | angular part Xc and the further outflow of electrolyte solution by this can be suppressed.

  Also in the third embodiment, the first region X is set at a position above the electrolyte surface as in the first and second embodiments. When the electrolytic solution surface upper limit position display means, that is, the electrolytic solution surface upper limit line 102a is provided as in the example shown in FIG. 3, the first region X is set above the electrolytic solution surface upper limit line 102a.

  In the present invention, the impact resistance value (Izod impact value) of the portion excluding the first region X of the battery case 302 is Iz1, the impact resistance value (Izod impact value) of the lid 103 is Iz2, and the battery case 302 and the lid 103 are When the impact resistance value (Izod impact value) of the joint 103b is Iz3 and the impact resistance (Izod impact value) of the first region X is Izx, Izx <Iz1, Izx <Iz2, and Ixz <Iz3.

  According to the third embodiment, when the lead storage battery 301 is internally ignited, the first region X is preferentially damaged, so that other parts are prevented from being damaged. As a result, the upward scattering of the electrolytic solution, the battery case 302 and the lid 103 is suppressed, and damage due to the scattering can be minimized.

  Further, in the third embodiment, as shown in FIG. 3, the first region X independent for each cell is provided. Therefore, even if internal ignition occurs in a certain cell and an impact occurs, only the first region corresponding to that cell is damaged, and the adjacent cells are prevented from being damaged. As a result, as compared with the lead storage batteries 101 and 201 according to the first and second embodiments, the fragments of the battery case 302 and the scattering of the electrolytic solution due to internal ignition are more significantly suppressed, which is a preferable mode.

  As in the first and second embodiments, in the third embodiment as well, it is preferable that (Iz1-Izx), (Iz2-Izx), and (Iz3-Izx) be 20 J / m or more. In addition, you may provide the 1st area | region X in 2nd Embodiment on both surfaces of the side surface 302c which has two surfaces. However, with the lead storage battery 301 mounted on a vehicle or device, the first region X may be provided on the side surface 302c on the side opposite to the side accessed by the lead storage battery 301 or the vehicle and device inspector. it can. According to this, when the lead storage battery 301 is damaged, the fragments and the electrolyte are scattered in a direction away from the inspector, and the damaged portion is almost limited to the internally ignited cell, preferable.

  The first region X in the third embodiment can be configured with reference to the first embodiment. That is, the first region X surrounded by the alternate long and short dash line z is formed by the double injection method, or the molding conditions of the first region X are different from those of the other parts, and the molding conditions are such that the impact resistance value decreases. Can be achieved.

  For example, a 55D23 type lead acid battery (12V48Ah) defined in JIS D5301 (starting lead acid battery) is specified so that the first region X is not damaged by an impact at the time of handling that is not caused by internal ignition such as dropping of the lead acid battery 301. , About 20 kg), for example, the impact resistance of the first region X can be 50 J / m or more, and the lower limit value of the impact resistance of the first region X is the first and the second described above. Similar to the second embodiment, it is a design matter that should be determined in consideration of the mass of the lead storage battery, and is not an essential component of the present invention.

  As an example of the setting value of the Iz impact value of each part in the third embodiment, Izx = 90 J / m in the first region X, and Iz1 = 120 J in the part excluding the first region of the battery case 302. / M, Iz2 = 120 J / m at the lid 103, and Iz3 = 120 J / m at the joint 103c. Obviously, these set values can also be applied to the second embodiment.

(Fourth embodiment of the present invention)
FIG. 4A is a diagram showing a top surface of a lead storage battery 401 according to the fourth embodiment of the present invention, and FIG. 4B is a diagram showing a side surface of the lead storage battery 401. A lead storage battery 401 according to the fourth embodiment of the present invention includes a cover member 402 that covers the lid 103 of the lead storage battery 101 according to the first embodiment of the present invention and exposes the terminals 107 and 107 ′.

  In the example shown in the figure, as the cover member 402, a sheet processed into a box shape having an opening 402a at the bottom is used. Terminals 107 and 107 'are exposed from the opening 402a. Further, if necessary, the opening 402a is disposed in the cover member 402 so that the liquid spout 105 is exposed so that the liquid spout 105 can be accessed through the opening 402a.

  As the cover member 402, a resin molded product that does not allow gas permeation can be used. However, the cover member 402 may be damaged by an impact during ignition inside the battery. It is comprised with the material which has. For example, it is preferable to use a nonwoven fabric, a woven fabric, a porous body, or a laminate of these layers.

  During ignition inside the battery, a pressure wave (or shock wave) is generated inside the battery, and the first region X is destroyed by the high atmospheric pressure applied to the first region X. By using a gas permeable member as the cover member 402, the wave of atmospheric pressure after destroying the first region X passes through the cover member 402 and diffuses into the atmosphere. Can be prevented from being damaged.

  In addition, the cover member 402 is more preferable because scattering of the fragments in the first region X when the battery is broken is suppressed. In addition, since the cover member 402 is porous, it can absorb a certain amount of electrolyte solution. Therefore, the splash of the electrolyte solution when the battery is broken can be captured by the cover member 402. The scattering of the electrolytic solution from the storage battery 401 is significantly suppressed.

  The shape of the cover member 402 is a structure that covers at least the outer surface of the first region X. Preferably, the cover member 402 is fixed to the first region X with a bonding member (not shown) such as an adhesive. Various adhesives such as rosin or its derivatives, acrylic emulsions, synthetic rubbers, and terpene resins can be used as the bonding member.

  In the configuration in which the cover member 402 and the first region X are fixed with an adhesive, even if the first region is crushed during internal ignition, the fragments are fixed inside the cover member 402 by the adhesive. Therefore, it is possible to prevent not only the fragments but also the dissipation of the fragments.

  In the example shown in FIG. 4B, the lower end of the cover member 402 is located below the first region X. However, the cover member 402 is connected to the first region X of the battery case 102, Fixing with a pressure-sensitive adhesive in a portion below the first region is more preferable because cracks from the first region to the lower portion are suppressed when the first region X is damaged.

  In the example shown in FIG. 4B, the lower end 402b of the cover member 402 is positioned slightly above the electrolyte solution upper limit line 102a. When the electrolytic solution surface upper limit line 102a is disposed in the battery case, if the lower end 402b covers the electrolytic solution surface upper limit line 102a, the electrolytic solution surface cannot be adjusted. Therefore, as long as the electrolytic solution surface upper limit line 102a is arranged in the battery case, at least the lower end 402b is set to be positioned above the electrolytic solution surface upper limit line 102a. Alternatively, the electrolytic solution upper limit line 102a may not be formed in the battery case 102, and the lower end 402b may be set as the upper limit of the electrolytic solution level, and the horizontal line formed by the lower end 402b may function as the electrolytic solution upper limit line. .

  The material of the cover member 402 is selected from woven or non-woven fabrics such as polypropylene fiber, polyethylene fiber, and glass fiber, porous materials such as polyurethane foam and EPDM rubber, and can be molded into the shape of the cover member 402. That's fine.

  Although the material of the cover member 402 is as described above, the cover member 402 preferably has a multilayer structure. This is because when the passage route until the electrolyte is scattered is considered, if the layer is a single layer, the passage route is often in a straight line. There is an effect that the liquid is less likely to pass through the cover member 402.

(Fifth embodiment of the present invention)
FIG. 5 is a view showing a lead storage battery 501 according to the fifth embodiment of the present invention. The lead storage battery 501 is obtained by mounting the cover member 402 shown in the fourth embodiment on the lead storage battery 201 according to the second embodiment described above. However, in FIG. 5, the two-dot chain line A indicating the position of the partition between the cell chambers is omitted.

  The form shown in the fourth embodiment can be applied to the shape of the cover member 402 and the form of attachment to the lead storage battery 201. The lead storage battery 501 according to the fifth embodiment has the effects of both the lead storage battery 201 according to the second embodiment and the lead storage battery according to the fourth embodiment.

(Sixth embodiment of the present invention)
FIG. 6 is a diagram showing a lead storage battery 601 according to the sixth embodiment of the present invention. The lead storage battery 601 is obtained by mounting the cover member 402 shown in the fourth embodiment on the lead storage battery 301 according to the third embodiment described above. However, in FIG. 6, the two-dot chain line A indicating the position of the partition between the cell chambers is omitted.

  The form shown in the fourth embodiment can be applied to the shape of the cover member 402 and the form of attachment to the lead storage battery 301. It is obvious that the lead storage battery 601 according to the sixth embodiment has both the effects of the lead storage battery 201 according to the third embodiment and the effects of the lead storage battery according to the fourth embodiment.

  As described above, each embodiment of the present invention has been described. In each of the above embodiments, a word, symbol, or design indicating a model number of a lead-acid battery, precautions for use, etc. on a portion covering the cover of the cover member 402. It is also possible to form a display such as a label, and by providing the cover member 402 with the function of a conventional label, the label and its attaching process become unnecessary, and the productivity and the position of the label attaching position can be reduced. It is preferable in terms of prevention.

  In each Example described below, the effect of the present invention was confirmed by creating batteries of the present invention and comparative examples, performing an internal ignition test, and confirming the damage status of the battery. Each of the batteries is a 55D23 type (12V48Ah) battery defined as a JIS D5301 starting lead-acid battery, and has a dilute sulfuric acid electrolytic solution in which all of the electrode plate surface is immersed in the battery.

Example 1
Example 1 is the lead storage battery 101 according to the first embodiment of the present invention, the Iz impact value of the first region X, the portion excluding the first region X of the battery case 102, the lid 103 and the joint 103a, Batteries that were changed in various combinations were created, and an internal flash test was conducted. The lid and the battery case were made of a copolymer of polypropylene and polyethylene, and the lid and the battery case were joined by heat welding. The Iz impact value was adjusted according to the polyethylene content in the resin.

  Table 1 shows combinations of Iz impact values of the respective parts constituting each battery. In addition, the Iz impact value of a junction part is obtained from the correlation of the impact resistance by the falling ball test of a lid | cover and a junction part. In this embodiment, the impact resistance of the joint is higher than the impact resistance of the lid.

  For the internal flammability test, each battery shown in Table 1 was fully charged, and further charged to a filament installed in the second cell chamber from the positive electrode terminal toward the negative electrode terminal while performing constant current charging at 4.8 A. Energized to intentionally generate internal ignition, and the state of damage to each battery and the state of scattering of the electrolyte were confirmed. The results are shown in Table 2.

  From the results shown in Table 2, according to the configuration of the present invention, since only the first region X having the lowest impact resistance provided in the battery case is damaged, the damaged portion is limited to the upper part from the electrolyte surface. It was. Moreover, since the lid was not damaged, the amount of scattering and outflow of the electrolyte was remarkably reduced as compared with the batteries 1-1 and 1-2. Moreover, the scattering direction of the fragments and the electrolytic solution is limited to the side of the battery in the battery of the present invention example.

  The difference in the Iz impact value between the first region X and other parts is 20 J / m or more, so that the degree of debris and electrolyte scattering is extremely small. According to such a configuration, the first region X is damaged early at the initial stage where the internal pressure of the battery rises due to the impact of internal ignition, so that it is considered that the degree of scattering of fragments and electrolyte is alleviated. This is a battery having the same impact resistance of 90 J / m as the highest value, except for the joint, as in the case of the battery 1-1, and the scattering distance of debris and electrolyte is also increased. Presumed.

  Therefore, according to the first embodiment of the present invention, the damaged part of the battery at the time of internal ignition is limited to the part of the battery case (first region X) above the electrolyte surface, and the scattering direction of the fragments is Since it is limited to the side of the battery, it is easy to deal with battery damage due to internal ignition. In particular, by reducing the Iz intensity (Izx) of the first region X by 20 J / m or more from the Iz intensity (Iz1) of the portion excluding the first region X of the battery case, the effect of the present invention can be obtained. It can be obtained more remarkably.

(Example 2)
Example 2 is the lead storage battery 201 according to the second embodiment of the present invention, the Iz impact value of the first region X, the portion excluding the first region X of the battery case 202, the lid 103 and the joint 103b, Batteries that were changed in various combinations were created, and an internal flash test was conducted. The lid and the battery case were made of a copolymer of polypropylene and polyethylene, and the lid and the battery case were joined by heat welding. The Iz impact value was adjusted according to the polyethylene content in the resin. The first region X was formed only on one surface of the side surface 202c and not formed on the other surface.

  Table 3 shows combinations of Iz impact values of the respective parts constituting each battery. In addition, the Iz impact value of a junction part is obtained from the correlation of the impact resistance by the falling ball test of a lid | cover and a junction part. In this embodiment, the impact resistance of the joint is higher than the impact resistance of the lid.

  About each battery shown in Table 3, when the internal flash test was implemented on the conditions similar to Example 1, the damage condition of each battery and the scattering condition of electrolyte solution were confirmed. The results are shown in Table 4.

  From the results shown in Table 4, according to the second embodiment of the present invention, compared with the first embodiment of the present invention described above, the first region having the lowest impact resistance provided in the battery case. Since only X was damaged, the damaged part was limited to the upper part from the electrolyte surface. Moreover, since the lid was not damaged, the amount of scattering and outflow of the electrolyte was remarkably reduced as compared with the batteries 1-1 and 1-2.

  In the battery 2-3, the battery 2-4, and the battery 2-5 of the present invention example, the scattering direction of the fragments and the electrolyte was limited to only one side of the battery. Therefore, since the scattering direction of the fragments and the electrolyte is limited to only one direction, the first embodiment of the present invention is intended to protect the device equipped with the lead storage battery and the inspector accessing the lead storage battery from damage to the battery. It was more preferable than the embodiment.

  In addition, among the batteries of the present invention example, the scattering of the electrolyte solution and the fragments was more significantly suppressed by setting the difference between Iz1, Iz2, and Iz3 and Izx to 20 J / m.

(Example 3)
Example 3 is the lead storage battery 301 according to the third embodiment of the present invention, the Iz impact value of the first region X, the portion excluding the first region X of the battery case 302, the lid 103 and the joint 103c, Batteries that were changed in various combinations were created, and an internal flash test was conducted. The lid and the battery case were made of a copolymer of polypropylene and polyethylene, and the lid and the battery case were joined by heat welding. The Iz impact value was adjusted according to the polyethylene content in the resin. Note that the first region X was formed only on one surface of the side surface 302c and not formed on the other surface.

  Table 5 shows combinations of Iz impact values of the respective parts constituting each battery. In addition, the Iz impact value of a junction part is obtained from the correlation of the impact resistance by the falling ball test of a lid | cover and a junction part. In this embodiment, the impact resistance of the joint is higher than the impact resistance of the lid.

  About each said battery, the internal flash test was done on the conditions similar to Example 1 and 2, and the damage condition of each battery after a test and the scattering condition of electrolyte solution were confirmed. The results are shown in Table 6.

  From the results shown in Table 6, according to the third embodiment of the present invention, compared with the first and second embodiments of the present invention described above, the first shock resistance provided in the battery case is the lowest. Since only the 1 area | region X was damaged, the damaged location was limited above the electrolyte surface. In addition, the damage is limited only to the internally ignited cells and does not spread to adjacent cells. Therefore, even if compared with the batteries of the present invention examples in Examples 1 and 2 described above, The degree of scattering was extremely slight. In addition, the outflow amount of the electrolyte decreased significantly.

  In the battery 2-3, the battery 2-4, and the battery 2-5 of the present invention example, the scattering direction of the fragments and the electrolyte was limited to only one side of the battery. Therefore, since the scattering direction of the fragments and the electrolyte is limited to only one direction, the first embodiment of the present invention is intended to protect the device equipped with the lead storage battery and the inspector accessing the lead storage battery from damage to the battery. It was more preferable than the embodiment.

  In addition, among the batteries of the present invention example, the scattering of the electrolyte solution and the fragments was more significantly suppressed by setting the difference between Iz1, Iz2, and Iz3 and Izx to 20 J / m.

Example 4
In the above-described Examples 1 to 3, the battery 1-3, the battery 1-4, the battery 2-3, the battery 2-4, the battery 3-3, and the battery 3-4 of each of the examples of the present invention in each example, In the fourth embodiment of the present invention, each of the battery 1-1, battery 1-2, battery 2-1, battery 2-2, battery 3-1, and battery 3-2 of the comparative example in the example was described. A cover member 402 was attached. Inside the cover member 402, an adhesive prepared by dissolving purified rosin in isopropyl alcohol was applied in the form of dots, and then the cover member 402 was fixed to each battery. And about each battery with which these cover members were mounted | worn, the internal flash test similar to Examples 1-3 was implemented.

The cover member 402 was manufactured as follows. That is, a porous sheet obtained by heating a nonwoven fabric of polypropylene resin fibers whose surface has been submerged by sulfonation (porosity 90% when pressed at 20 kPa) while pressing in the thickness direction is formed into a shape of the cover member 402. It was processed into. The porosity of the cover member 402 is 80%, and it has good air permeability and liquid content. The air permeability of the cover member 402 is 1 L / min. Per 1 cm ^{2 of the} cover member area. The pressure loss when passing the air was 4 kPa. Since the cover member 402 is applied in the form of dots, the air permeability of the cover member is ensured even when the cover member 402 is attached to the battery.

  Table 7 shows the state of each battery after the internal flash test in each battery. In this embodiment, a cover member 402 is attached. Battery No. in Table 7 About battery No. of Table 1-Table 6. A suffix of C is added at the end of. For example, a battery in which the cover member 402 is attached to the battery 1-1 is the battery 1-1C.

  From the results shown in Table 7, in the battery of the present invention equipped with the cover member 402, the fragments and electrolyte solution are trapped by the cover member, so that the battery case and lid fragments and electrolyte solution scatter when the battery ignites. Can be remarkably suppressed.

  In Example 4, a test was conducted in which the cover member 402 was not fixed to the battery with an adhesive. As a result, in the battery of the present invention, debris dropped to the bottom of the battery and did not scatter. Further, the electrolyte solution scattered from the battery was prevented from being scattered by the cover member.

(Example 5)
In each of the above examples, the behavior of the battery of the present invention and the battery of the comparative example at the time of internal ignition was compared, but in Example 5, the behavior of the comparative example of the battery of another specification at the time of the internal ignition test was compared. confirmed. In addition, the battery of a comparative example is also a 55D23 type lead acid battery for start-up similar to each battery of Examples 1-5.

[Battery A1 of Comparative Example]
FIG. 7 is a diagram showing a battery A1 of a comparative example. The battery A1 has a lid 103, terminals 107 and 107 ′, and a liquid spout 105 attached to the lid 103, like the battery of the present invention example. The battery case 701 of the battery A1 has the same shape and dimensions as the battery case 102. However, a U-shaped groove (indicated by a one-dot chain line K in FIG. 7) is provided for each cell on the side surface 701a of the battery case 701.

  Further, the U-shaped groove is formed with a depth of 0.8 mm with respect to the thickness (1.8 mm) of the battery case 701. Furthermore, the U-shaped groove provided for each cell does not straddle the partition wall (indicated by a two-dot chain line A in FIG. 7) that divides the cell, and the U-shaped groove is independent for each cell. Is provided.

[Battery A2 of Comparative Example]
FIG. 8 is a diagram showing a battery A2 of another comparative example. In the battery A2, the U-shaped groove in the battery A2 illustrated in FIG. 7 is an inverted U-shaped groove (indicated by a two-dot chain line L in FIG. 8). Note that the U-shaped groove and the inverted U-shaped groove have the same depth, and the shape of one groove rotated by 180 ° coincides with the shape of the other groove.

[Battery A1C of Comparative Example]
The battery A1C of the comparative example is applied to the battery A1 with an adhesive (same as that used in Example 4) in which the cover member 402 used in each of the above-described examples is applied in a dotted manner to the battery A1 of the comparative example. It is fixed.

[Battery A2C of Comparative Example]
The battery A2C of the comparative example is the same as the battery A2 of the comparative example described above, and the adhesive (which is the same as that used in Example 4) obtained by applying the cover member 402 used in each of the above-described examples in a dotted manner. It is fixed.

[Battery A3 of Comparative Example]
The battery A3 of the comparative example is obtained by forming a groove portion in which the U-shaped groove portion in the battery A1 of the comparative example described above is closed in a substantially rectangular shape with the shape indicated by the alternate long and short dash line z 'in FIG. The depth of the groove portion is 0.8 mm with respect to the thickness of the battery case of 1.8 mm, similarly to the batteries A1 and A2.

[Battery A3C of Comparative Example]
The battery A3C of the comparative example is applied to the battery A3 with an adhesive (same as that used in Example 4) in which the cover member 402 used in each of the above-described examples is applied in a dotted manner to the battery A3 of the comparative example. It is fixed.

  About each above described battery, the internal flash test was done on the same conditions as Examples 1-4. The results of this test are shown in Table 8.

  From the results shown in Table 8, for the batteries A1, A2, A1C, and A2C of the comparative examples, the breakage of the lid or the battery case proceeds due to the growth of cracks from the end of the U-shaped or inverted U-shaped groove. For this reason, even if the cover member 402 is used in combination, it is difficult to avoid the scattering of lid fragments or the large outflow of the electrolyte.

  In the result of Example 5, since the groove portion was not formed in a closed shape, a crack was generated from the end portion of the groove portion, and the degree of breakage was enormous. Therefore, it is understood that it is essential that at least the groove portion has a closed shape.

  On the other hand, it was impossible to keep the damage within a certain region simply by forming a closed groove. That is, it is understood that the range of breakage cannot be controlled simply by forming a portion having a weak mechanical tensile strength (a groove portion in Example 5).

  In the present invention, attention is paid to the impact resistance of the battery case or the lid, and the closed region is formed in a region located on the liquid surface of the battery case with low impact resistance.

  And according to the present invention, by limiting the battery damage due to the impact during ignition inside the battery to the lid, the scattering of the electrolyte is suppressed, and by using the cover member, the fragments produced by the damage of the lid Scattering can be suppressed. Further, the amount of scattering of the electrolytic solution can be further reduced by the action of absorbing the electrolytic solution of the cover member.

  In each example, the example in which the present invention is applied to a liquid type lead storage battery has been described. However, it is obvious that the present invention can also be applied to a control valve type lead storage battery having a free electrolytic solution released from an electrode plate group. .

  In this embodiment, the first region X is formed by double injection. However, the molding temperature conditions (mold temperature, cooling rate) of the portion excluding the first region X and the first region X of the battery case are set. Even if the first region X having a low impact resistance was formed by changing, the same result as in this example was obtained.

  The present invention makes it possible to minimize the damage of the battery when the gas in the battery is ignited internally due to some factor, and the start lead storage battery exemplified in the embodiment and the examples alone. It can be used for lead storage batteries of various applications and types including control valve type lead storage batteries.

DESCRIPTION OF SYMBOLS 101 Lead storage battery 102 Battery case 102a Electrolyte surface upper limit line 102b Electrolyte surface lower limit line 103 Lid 103a, 103b, 103c Joint 104 Liquid port 105 Liquid port plug 106 Gas exhaust port 107, 107 'Terminal 201 Lead storage battery 202 Battery case 202c Side surface 301 Lead storage battery 302 Battery case 302c Side surface 401 Lead storage battery 402 Cover member 402a Opening 402b Lower end 501 Lead storage battery 601 Lead storage battery 701 Battery case 701a Side surface A1 battery B1 battery X first region Xc corner

Claims (9)

A lead-acid battery comprising a battery case having a positive electrode plate, a negative electrode plate, a separator and a cell chamber for storing an electrolyte, and a lid having a terminal formed on the surface thereof, wherein the opening of the battery case is closed, In the battery case, having an electrolytic solution, on the outer wall of the battery case, above the liquid surface of the electrolytic solution, and at least a part below the joint between the lid and the battery case, It has a first region that is lower in impact resistance than the other part of the outer wall of the battery case and is closed on the surface of the outer wall, and the impact resistance of the first region is the impact resistance of the lid. Lead-acid battery characterized by being lower than the resistance and impact resistance of the joint. The Izod impact value of the first region is Izx, the Iz impact value of the portion excluding the first region on the outer wall of the battery case is Iz1, the Iz impact value of the lid is Iz2, and the Iz impact value of the joint portion The lead-acid battery according to claim 1, wherein each of (Iz1-Izx), (Iz2-Izx), and (Iz3-Izz) is 20 J / m or more, when Iz3 is set. The lead acid battery according to claim 1 or 2, wherein the first region and the portion of the battery case excluding the first region on the outer wall of the battery case are made of different materials. The lead storage battery according to claim 1, wherein the first region is covered with a cover member. The lead storage battery according to claim 4, wherein the cover member is made of a material having gas permeability. The lead acid battery according to claim 5, wherein the cover member and the first region are joined to each other with an adhesive. The lead storage battery according to claim 5, wherein the cover member is made of a non-woven mat, a woven fabric, a porous body, or a layered body thereof. The cover member covers at least a part of the lid, and a part of the cover member covering the lid is formed with a display of a word, a symbol, a design, or the like indicating a model number of the lead storage battery, precautions for use, etc. The lead acid battery of Claims 4-7. The lead acid battery according to claim 1, further comprising an electrolyte liquid surface upper limit position display means such as a liquid surface upper limit line provided in the battery case.

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