JP2009152032A - Lead storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain battery breakage due to discharge spark of static electricity as when hydrogen gas and oxygen gas generated at last stages of charging stay inside a lead storage battery, and at the same time, to improve on its safety, reliability, and further, workability at actual use. <P>SOLUTION: A lid is provided with conductive layers circularly surrounding liquid holes each corresponding to each cell, and the conductive layers are each integrally structured in a direction of electric connection to be connected with a negative electrode terminal, so that static electricity is absorbed through the conductive layer to have breakage due to ignition prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lead-acid battery.

  A lead storage battery is mounted on a vehicle or the like using an internal combustion engine as a power source, and is used as a power source for starting. These lead-acid batteries are charged while the vehicle is running by a generator mounted on the vehicle, but when the stoppage time is long, the discharge proceeds due to shortage of charging by many accessory devices or forgetting to turn off lights etc. In some cases, the battery may be directly charged by a charger with the battery removed.

  In the lead storage battery, electrolysis of the electrolyte occurs at the end of charging, and hydrogen gas and oxygen gas generated by water electrolysis stay in the lead storage battery. If there is an ignition source here, rapid combustion occurs, and in some cases, the battery may be damaged. On the other hand, battery damage that may be caused by static electricity may also occur. For example, when the battery is wiped with a dry cloth, or when a person tries to touch the battery while being charged with static electricity, the static electricity may be discharged, and the spark may be a source of ignition.

  In order to solve these problems, Patent Document 1 proposes that a member that is electrically conductive is provided in a region on the surface portion of the lid, and the conductive member is connected to a terminal. However, the path through which static electricity enters the battery is often near the liquid plug or liquid port, and if the part that conducts to the surface of the lid is stretched in a grid (regional), a conductive layer exists near the static electricity intrusion path In some cases, static electricity was not reliably captured.

Further, Patent Document 2 proposes a method in which a layered body whose surface is an insulating layer and whose back is conductive is provided on the upper surface and covers the liquid mouth portion. In this case, the layered body has to be removed in the replacement work when the battery is actually used, and the layered body may be corroded by the sulfuric acid electrolyte.
Japanese Patent Laid-Open No. 11-233078 JP-A-4-101353

  An object of the present invention is to suppress battery damage due to static discharge sparks as described above, and to improve safety, reliability, and workability during actual use.

  In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention has a liquid port for mounting a liquid port plug corresponding to each cell on a lid made of an insulating material, and the periphery of the liquid port is annular. A lead-acid battery characterized in that a conductive layer is provided on the surface of the lid so as to surround the conductive layer, and the conductive layer is integrally formed continuously in the electric connection direction of the cell and is electrically connected to the negative electrode terminal. It is.

  The invention according to claim 2 of the present invention is directed to a lead-acid battery in which the conductive layer is provided on the surface of the lid in a ring shape with a gap from the liquid port.

  The invention according to claim 3 of the present invention shows a lead-acid battery characterized by having a water-repellent portion on the surface of the lid in the gap between the conductive layer and the liquid port.

  In the invention according to claim 4 of the present invention, a convex portion is provided on the surface of the lid so that the periphery of the liquid port is annularly higher than the surface of the lid, and the outer surface of the convex portion is provided on the conductive layer. The lead acid battery characterized by covering with is shown.

  The lead storage battery according to claim 5 of the present invention is characterized in that the conductive layer has a surface covered with an insulating sheet, and an exposed portion is provided so as to surround the liquid port in an annular shape. Is shown.

  The invention according to claim 6 of the present invention is directed to a lead storage battery characterized in that the surface of the conductive layer is covered with a porous water repellent material.

  According to the configuration of the present invention described above, safety and reliability are reduced by suppressing battery damage due to electrostatic discharge sparks during handling of lead-acid batteries and suppressing corrosion of the conductive layer due to leakage during actual use. Furthermore, the lead storage battery which improved workability | operativity can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1A and 1B are an external view and a cross-sectional view taken along line AA ′ of the lead storage battery according to Embodiment 1 of the present invention. In the lead storage battery, a lid 2 is integrated on the top of the battery case 1, the lid 2 has a liquid port 3 corresponding to each cell, and the liquid port 3 is fitted with a liquid port plug 4. 5 and a positive electrode terminal 6 are provided.

  The surface of the lid 2 made of polypropylene resin is provided with a conductive layer 7 so as to surround the liquid port 3 of each cell in a ring shape with a width of 2 mm to 8 mm, and the annular conductive layer 7 of each cell is connected in the electrical connection direction. A part of the conductive layer 7 is connected to the negative electrode terminal 5. The conductive layer 7 is formed in a continuous series of sheets around the liquid port 3, for continuation of each cell, and connection to the negative electrode terminal 5.

  The conductive layer 7 is a sheet having an acid-resistant adhesive on the back surface of a lead foil having a thickness of 100 μm, and is attached to the surface of the lid 2, and an opening of the conductive layer 7 is attached so as to correspond to the cylinder of the negative electrode terminal 5. However, since the negative electrode terminal 5 is made of a lead alloy, it can be welded. The material used for the conductive layer 7 is a metal-based material such as lead, copper, or aluminum that is generally easily available and is less conductive than the metal-based material. The same effect can be obtained even when a material using a polymer is used. Furthermore, since it is disposed in the vicinity of the liquid port 3, it is preferable to use a material having acid resistance or a material subjected to acid resistance treatment. Moreover, you may affix as a label which gave acid resistant adhesive to these materials.

  The reason why the conductive layer 8 is connected to the negative electrode terminal 5 is that the negative electrode terminal itself exists in a reduced state and in the form of metallic lead, and the positive electrode terminal 6 may generate a nonconductive substance on the surface in the oxidized state. In order to reliably absorb static electricity, it is preferable to use the negative electrode terminal 5. Furthermore, since the negative electrode of the lead-acid storage battery for starting is connected to the vehicle, it is possible to prevent a short circuit when mounted on the vehicle.

  Since normal discharge of static electricity to the storage battery occurs between the positive electrode terminal 6, the negative electrode terminal 5, the liquid spout 4 and the power generation element, the power generation element in which the static electricity stored between the storage battery and the human body first approaches Discharge occurs. In the case of the positive electrode terminal 6 and the negative electrode terminal 5, it can be absorbed into the battery through the pole column 6 a of the positive electrode terminal 6 and the pole column 5 a of the negative electrode terminal 5, but electrostatic discharge in the vicinity of the liquid spout 4 Cannot be absorbed inside the battery, and discharges directly from the liquid port 3 into the battery, so that sparks fly inside the battery. For this reason, with the above configuration, when the static electricity is discharged to the battery in the vicinity of the liquid port 3, if the conductive layer 8 exists in a ring shape near the liquid port, the static electricity is transmitted through the conductive layer 8 and the negative electrode terminal 5. It is absorbed inside the battery via

  As a preferred embodiment of the present invention, FIG. 2 is an explanatory view and an AA ′ sectional view of a conductive layer that annularly surrounds the liquid port in the lead storage battery of the present invention. By providing the gap 8 between the conductive layer 7 and the liquid port 3, the gap 8 suppresses the contact between the sulfuric acid of the electrolytic solution rising from the liquid port stopper and the liquid port and the conductive layer 7. Leakage current caused by contact of the conductive layer with sulfuric acid can be prevented. The width of the gap 8 is preferably set to about 1 mm to 5 mm.

  As a preferred embodiment of the present invention, FIG. 3 is an explanatory view of a lead storage battery having a water repellent agent in the gap 8 between the conductive layer 7 and the liquid port 3 of the present invention and an AA ′ cross-sectional view. The surface of the gap 8 in the vicinity of the periphery of the liquid port 3 is coated with a water repellent 9 formed by applying a fluororesin emulsion and then baking and drying, whereby sulfuric acid leaked from the liquid port 3 is applied to the conductive layer 7. It is possible to prevent migration and suppress inter-cell leakage and corrosion of the conductive layer 7.

  As a preferred embodiment of the present invention, FIG. 4 is an explanatory view and A-A ′ sectional view of a lead storage battery having an annular convex portion 10 around the liquid port, and the surface of the lid is circularly formed around the liquid port 3 of the lid. An annular convex portion 10 that is higher is provided. The annular convex portion 10 may be molded integrally with the lid, but the same ring-shaped polypropylene resin 11 as the lid is welded and integrated around the liquid mouth so that the upper and outer outer surfaces of the ring-shaped polypropylene resin 11 are formed. A conductive layer 7 is formed so as to cover it. The higher the ring-shaped convex portion 10 from the surface of the lid 2 is, the easier it is to absorb static electricity, but the height is preferably set to about 1 mm to 30 mm as practicality of the startable lead-acid battery.

  As a preferred embodiment of the present invention, FIG. 5 is an explanatory view and A-A ′ cross-sectional view of a lead-acid battery that is insulation-coated except for the liquid port 3 of the conductive layer 7. That is, the insulating sheet 12 is covered except for the connection portion 5 b with the terminal 5. The conductive layer 7 is opened so as to correspond to the liquid port 3, and is formed and arranged in a wide band shape, and then the insulating sheet 12 in which the conductive layer 7 is exposed so as to surround the liquid port 3 of each cell in an annular shape. And it comprises by covering a conductive layer. As the insulating sheet 12, a 0.2 mm polypropylene sheet having adhesiveness on the back surface can be used.

  As a preferred embodiment of the present invention, FIG. 6 is an explanatory view in which the surface of the conductive layer of the lead storage battery of FIG. A water repellent layer 13 is formed on the surface of the conductive layer 7 used in the lead storage battery of FIG. 1, and the water repellent layer 13 is made of a powdery fluororesin or silicon resin, and a non-lead foil used for the conductive layer 7. It adheres to the adhesion surface, that is, the surface, and is fired as long as the porosity is not lost. By providing the water repellent layer 13, it is possible to prevent the conductive layer 7 from being corroded by sulfuric acid leaked from the liquid port 3 and to reduce liquid leakage.

  In the above description, the acid-resistant adhesive material is used for fixing the conductive layer 7. However, a method of fitting the conductive layer into a recess provided in the lid 2 or a method of integrally molding with the lid may be used.

  The effects of the present invention will be described by the following examples.

  As a test battery, 55B24L defined in JIS D5301 lead acid battery for starting was used. Test batteries A1 to A6 of the present invention were batteries prepared by the configuration described in the best mode for carrying out the invention, and six batteries were prepared and tested. The contents of the test battery are as follows.

A1 is a test battery configured in FIG. 1 as a preferred embodiment of the present invention. A2 is a preferred embodiment of the present invention. A test battery configured in FIG. 2 is a preferred embodiment of the present invention. The test battery A4 configured in FIG. 3 is a preferred embodiment of the present invention, and the test battery A5 configured in FIG. 4 is a preferable embodiment of the present invention. A6 is a test battery configured in FIG. 6 as a preferred embodiment of the present invention.

  In FIG. 7, the structure of the conventional lead storage battery was shown as explanatory drawing and AA 'sectional drawing of a comparative lead storage battery. For the test battery B for comparison, six lead storage batteries, the same 55B24L as the battery used in the present invention, were prepared. A liquid port 3 is provided on the surface of the lid 2 so as to correspond to each cell, and a lead-like grid-like conductive layer 7a is arranged around the liquid port, and the end of the grid-like conductive layer 7a is the negative electrode terminal 5 Configured to connect to. The distance 8 to the grid-like conductive layer 7a closest to the liquid port 3 was set to 1 mm to 5 mm, which is the same as the test battery of the present invention.

  The following evaluation tests were performed on each of the above test batteries.

(Experiment 1)
The occurrence of battery damage was investigated by applying static electricity around the liquid stopper. After charging the test battery at a 5-hour rate for 10 hours, a test using static electricity was conducted while further charging was continued. For static electricity, 30 kV was applied between the negative electrode terminal and an electrode placed 5 mm apart from the top of the lid. The position of the electrode is set to a mesh of 5 mm intervals in the range of 25 cm × 12.5 cm of the lead storage battery upper surface dimension, moved on the intersections forming the mesh, once at each intersection, about 1300 times with one test battery Was applied. These test results are shown in Table 1.

  None of the test batteries A1 to A6 according to the present invention were damaged, but in the comparative battery B, one of the six batteries was damaged by ignition. As a result of investigating the damaged battery B, it was estimated that the intersection where the voltage was applied was in the vicinity of the liquid port, and static electricity was not absorbed by the conductive layer.

(Experiment 2)
After charging the test battery at a rate of 5 hours for 10 hours, a dilute sulfuric acid electrolyte solution was sprayed on the surface of the 30 cc lid by spraying and left for 1 month, and the change in open circuit voltage and the corrosion state of the conductive layer were examined. These results are shown in Table 2.

  In the condition of the conductive layer, ◯ indicates that it was not affected at all, △ indicates that the surface of the conductive layer was corroded, but indicates that it had a function as a conductive layer, and × indicates that due to corrosion This shows a case where a defect of the conductive layer was observed and the function of the conductive layer was lost. Since the test battery B of the comparative example had a liquid junction between the conductive layer and the positive electrode terminal, the corrosion progressed remarkably. Therefore, it was considered that the leakage current increased and the voltage decreased. Since A3, A4, and A5 of the present invention have many portions where the conductive layer is covered, almost no corrosion was observed, and the circuit voltage was not significantly lowered by leakage current. Since A1 has a structure in which the conductive layer is exposed on the lid surface, it has a function of the conductive layer although voltage drop is observed, and it is in a state where it can sufficiently absorb static electricity. In addition, although A6 had a water-repellent layer on its surface, it was considered that there was a slight difference in the reliability of the water-repellent layer, resulting in leakage current.

  As described above, the conductive layer surrounding the liquid port in an annular shape was provided and electrically connected to the negative electrode terminal, so that static electricity generated near the liquid port could be reliably absorbed by the conductive layer.

  As described above, according to the configuration of the present invention, since it is possible to obtain a lead storage battery that suppresses battery damage due to electrostatic discharge sparks and improves safety, reliability, and workability during actual use, it is extremely industrially Useful.

(A) External view of the lead storage battery of the present invention, (b) AA ′ cross-sectional view (A) Explanatory drawing of lead acid battery which has the conductive layer which encloses a liquid port annularly, (b) AA 'sectional drawing (A) Explanatory drawing of a lead storage battery having a water repellent in the gap between the conductive layer and the liquid port, (b) AA ′ cross-sectional view (A) Explanatory drawing of a lead storage battery having an annular protrusion around the liquid port, (b) AA ′ cross-sectional view (A) Explanatory drawing of lead acid battery which carried out insulation coating except the liquid mouth part of the conductive layer, (b) AA 'sectional drawing (A) Explanatory drawing which water-repellent-treated the conductive layer surface of the lead acid battery of FIG. 1, (b) AA 'sectional drawing (A) Explanatory drawing of lead acid storage battery of comparative test battery, (b) AA 'sectional view

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery case 2 Lid 3 Liquid port 4 Liquid port plug 5 Negative electrode terminal 5a Negative electrode terminal pole 5b Connection part with negative electrode terminal 6 Positive electrode terminal 6a Positive electrode terminal pole 7 Conductive layer 7a Grid-shaped conductive layer 8 Gap 9 Water repellent Agent 10 Annular convex 11 Ring-shaped polypropylene resin 12 Insulating sheet 13 Water repellent layer

Claims (6)

The lid made of an insulating material has a liquid port for mounting a liquid port plug corresponding to each cell, and a conductive layer is provided on the surface of the lid so as to surround the liquid port in a ring shape. A lead-acid battery characterized by being continuously integrated in the direction of electrical connection and electrically connected to the negative terminal. The lead-acid battery according to claim 1, wherein the conductive layer is provided on the surface of the lid in a ring shape with a gap from the liquid port. The lead acid battery according to claim 2, further comprising a water repellent portion on a surface of the lid in the gap between the conductive layer and the liquid port. The convex surface is provided on the surface of the lid so that the periphery of the liquid port is annularly higher than the surface of the lid, and the outer surface of the convex portion is covered with the conductive layer. Lead acid battery. The lead-acid battery according to claim 1, wherein the conductive layer is covered with an insulating sheet, and an exposed portion is provided so as to surround the liquid port in an annular shape. The lead acid battery according to claim 1, wherein the surface of the conductive layer is covered with a porous water repellent material.

Images