JP2010009816A - Dry battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dry battery capable of gas exhaustion at pressure rise of the inside sealed by a sealing body equipped with an explosion-proof thin part at a power-generating member side of a gasket as well as a protrusion cut up from a bottom plate at a corresponding position, capable of restraining scatter of electrolyte solution, and realizing large capacity due to thinning of a gasket. <P>SOLUTION: The dry battery houses a power generating member having a cathode mixture 6 and a gel-like anode mixture 5 arranged in opposition inside a battery case 8 with an interposition of a separator 7, and an opening of the battery case 8 is sealed with a sealing body 4 provided with a bottom plate 3 equipped with a cut-up protrusion 11 and an explosion-proof thin part 1c at a power-generating side of the gasket 1 made of an insulating material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dry battery in which an explosion-proof valve is broken and gas is quickly released when an internal pressure is abnormally increased.

  2. Description of the Related Art In recent years, there is a strong demand for extending the life of components of installed devices and especially alkaline manganese batteries, which are one of power sources, as digital still cameras or portable music players are driven for a long time. In the conventional alkaline manganese batteries used in the above equipment, in order to increase the internal battery capacity by increasing the internal volume with the same external dimensions, miniaturization of parts constituting the alkaline manganese battery, in particular, the insulation function and safety valve formed of resin It was indispensable to make the gasket as a mechanism thin.

  FIG. 8 is a partial cross-sectional front view of a conventional alkaline manganese dry battery. In an iron battery case 38 that also serves as a positive electrode terminal, a plurality of positive electrode mixtures 36 made of manganese dioxide and graphite and mainly formed into a short cylindrical shape are inserted. Inside the positive electrode mixture 36, a gel-like negative electrode agent 35 is injected through an insulating cap 30 for isolating contact with the battery case 38 on the bottom surface and a cylindrical separator 37. A negative electrode current collector 32 is inserted into the negative electrode agent 35. In general, the gasket 31 is made of plastic or rubber, and has a structure in which the opening of the battery case 38 is sealed in combination with the bottom plate 33, the current collector 32, and the like. The battery case 38 is covered with an exterior label 39 that also serves as insulation from the outside.

  In general, the gasket 31 is molded by, for example, an injection molding method in which a molten thermoplastic resin is fed into a mold, and receives internal pressure from the bottom wall portion 31d. By providing an annular groove 31a on the pressure receiving side of the flat plate portion 31b of the gasket 31, the bottom wall portion 31d is made an explosion-proof thin portion 31c. When the internal pressure reaches a certain pressure when the gas is generated and the internal pressure rises, the explosion-proof thin portion 31c of the bottom wall of the groove 31a breaks, and the explosion-proof mechanism discharges the gas inside the battery. The thing which works is proposed (for example, refer patent document 1).

  Further, as shown in FIG. 9, the extension distance of the explosion-proof thin part 41 c arranged on the extension of the skirt part of the gasket 41 is regulated by the rib 44 provided on the flat part, and the extension of the explosion-proof thin part 41 c is changed. There has been proposed a mechanism shape that reduces a reduction in the extension distance of the explosion-proof thin portion 41c due to the thinning of the gasket 41 and realizes a space that can be sufficiently extended and broken when the internal pressure increases (see, for example, Patent Document 2).

Further, it has been proposed to change the material of the gasket and change the extension characteristic of the explosion-proof thin-walled portion 31c in the gasket 31 shown in FIG. 8 to reduce the extension until reaching the break (see, for example, Patent Document 3). .
Japanese Patent Laid-Open No. 9-45303 JP 2003-217532 A JP-A-2005-79021

However, in the conventional technique shown in Patent Document 1 described above, the height of the parts of the gasket 31 shown in FIG. When the internal pressure rises due to discharge or reverse connection, the explosion-proof thin-walled portion 31c is pressurized or stretched at a shortened distance between the gasket 31 and the bottom plate 33 to break and stabilize the internal gas. There is a problem that it is difficult to discharge, which is a barrier to increasing the capacity. In addition, there is a problem that safety is lacking because the electrolyte solution, which is a strong alkaline substance interposed between the gas and the separator 37, is exhausted vigorously.

  In the prior art disclosed in Patent Document 2 described above, as shown in FIG. 9, the gasket 41 is disposed on the flat surface portion of the gasket 41 with the temperature rise of the gasket 41 as the internal temperature rises when the internal pressure rises. In order for the elongation of the material of the rib 44 to change and the explosion-proof thin portion 41c to break, there is a problem that a distance is required between the bottom plate 43 and the explosion-proof thin portion 41c to extend the material, It is difficult to reduce the thickness of the gasket 41, which is a barrier for increasing the capacity.

  Further, in the prior art disclosed in Patent Document 3 described above, the material elongation of the gasket 31 changes in the temperature rising state of the gasket 31 as the internal temperature rises when the internal pressure rises as shown in FIG. However, in order to break the explosion-proof thin portion 31c, there is a problem that a distance is required between the bottom plate 33 and the explosion-proof thin portion 31c to extend the material, and it is difficult to make the gasket 31 thin. It is a barrier to high capacity.

  The present invention has been made in view of the above-described conventional problems. A groove is provided on the power generation member side of the gasket to provide an explosion-proof thin part, and a protrusion cut from the bottom plate at a position corresponding to the explosion-proof thin part of the gasket. It is possible to provide a large-capacity dry battery by reducing the thickness of the gasket while enabling stable gas discharge when the internal pressure rises and suppressing the scattering of the electrolyte. It is said.

  In order to achieve the above-described object, the dry battery of the present invention accommodates a power generation member in which a positive electrode mixture and a negative electrode agent are disposed opposite to each other with a separator interposed in a battery case, and the opening of the battery case is insulated from the bottom plate. In a dry battery sealed with a sealing member composed of a gasket made of a material, an explosion-proof thin wall portion having a groove portion is formed on the power generation member side of the gasket, and the gasket is cut from the bottom plate at a position corresponding to the explosion-proof thin wall portion of the gasket. It is characterized by providing a protruding portion.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the dry battery which was excellent in explosion-proof operation | movement property and suppressed scattering of the electrolyte solution at the time of gas discharge | emission.

  According to the first aspect of the present invention, a power generation member in which a positive electrode mixture and a negative electrode agent are disposed to face each other with a separator interposed therebetween is housed in a battery case, and an opening of the battery case is formed as a gasket made of a bottom plate and an insulating material. By forming a groove on the power generation member side to form an explosion-proof thin part, and providing a protrusion raised from the bottom plate at a position corresponding to the gasket's explosion-proof thin part, the gasket The explosion-proof thin wall portion can be efficiently broken.

  In the second invention of the present invention, by providing a plurality of projections corresponding to the explosion-proof thin part, the pressure balance on the plane varies when the internal pressure rises due to gas, and the position where the explosion-proof thin part extends is Even if it fluctuates, by always touching a part of the plurality of projecting portions, it is possible to perform stable breakage and exhaust gas.

  In the third invention of the present invention, the tip of the protrusion is sharpened so that the explosion-proof thin wall portion formed of a soft resin extends to a certain height when the internal pressure rises, and the upper surface of the annular explosion-proof thin wall portion is the protrusion portion. It is possible to efficiently rupture and exhaust gas by the sharp part.

In the fourth aspect of the present invention, by providing a gas passage through which gas passes even if the explosion-proof thin part of the gasket is in close contact with the protrusion, the upper surface of the explosion-proof thin part is broken at the tip of the protrusion when the internal pressure rises. At the same time, it is possible to exhaust the gas without blocking the gas through the gas flow path between the thin portion and the protruding portion even after the breakage, and it is possible to prevent the electrolytic solution inside from being scattered during the discharge.

  In the fifth invention of the present invention, the gas flow path is a groove formed on the surface of the projection, so that the upper surface of the annular explosion-proof thin portion is broken at the tip of the projection when the internal pressure is increased, and at the same time after the break In addition, gas can be exhausted to the outside without blocking gas through a groove-shaped gas flow path between the explosion-proof thin wall part and the projection part, and the internal electrolyte is accommodated in the groove formed in the projection part at the time of discharge. Can not be scattered.

  In the sixth aspect of the present invention, the gas flow path is a slit formed in the height direction of the protrusion, so that the gas can be exhausted without being cut off as in the case of the groove-shaped gas flow path. In addition, it is possible to prevent the electrolyte contained in the interior as the gas is exhausted from being scattered.

  In the seventh invention of the present invention, the gas flow path is formed as a rough uneven part formed by roughing on the surface of the protrusion, so that the gas flow is not cut off as in the case of the groove-shaped gas flow path. It can be evacuated, and the projections and depressions on the surface of the protrusion increase the surface area shielded by the electrolyte inside, and as a result, it is possible to shield only the electrolyte that is discharged, so that the electrolyte does not scatter be able to.

  The best mode for carrying out the present invention will be described below with reference to the drawings. An embodiment shown below shows the structure of a typical alkaline manganese dry battery as a dry battery listed for explaining the present invention, and the present invention specifies the structure of the dry battery as follows. Not what you want.

  FIG. 1 is a half sectional view of an alkaline manganese battery in one embodiment of the present invention. As shown in FIG. 1, a plurality of positive electrode mixtures 6 made of manganese dioxide and graphite as main constituent materials and formed into a short cylindrical shape are inserted into an iron battery case 8 also serving as a positive electrode terminal. Inside the positive electrode mixture 6, a gelled negative electrode agent 5 is injected through a separator 7.

  The negative electrode current collector 2 is inserted into the gelled negative electrode agent 5, and an insulating cap 10 is inserted on the bottom surface of the gelled negative electrode agent 5 for the purpose of insulation from the battery case 8. Further, an exterior label 9 is wound for the purpose of insulating coating of the battery case 8 and the exterior of the product.

  In general, the gasket 1 is made of plastic or rubber, and a negative electrode current collector 2 welded to the bottom plate 3 is press-fitted into the axial center of the gasket 1 and called a sealing body 4. 4, an alkaline manganese dry battery is configured by sealing the opening of the battery case 8. In general, the gasket 1 is molded by, for example, an injection molding method in which a molten thermoplastic resin is fed into a mold, and receives internal pressure from the bottom wall portion 1d. By providing an annular groove portion 1a on the pressure receiving side of the flat plate portion 1b of the gasket 1, the bottom wall portion 1d is made an explosion-proof thin portion 1c. Gas is generated when the dry battery is overdischarged or when the dry battery is reversely connected, and when the internal pressure rises and the internal pressure reaches a pressure at which deformation of the explosion-proof thin part 1c starts, the explosion-proof thin part 1c is moved outward. The explosion-proof thin-walled portion 1c is pierced by the projection 11 provided by cutting and raising the bottom plate 3, and the explosion-proof thin-walled portion 1c of the bottom wall portion 1d of the groove 1a is ruptured. The internal gas is discharged through the processing hole 11a of the protrusion 11 provided.

As this explosion-proof mechanism, the explosion-proof thin-walled portion 1c and the protrusion 11 will be described in more detail. Increase in internal pressure caused by gas generation of dry battery caused by overdischarge or reverse connection with respect to the explosion-proof thin-walled portion 1c formed in a ring-shaped groove portion 1a having a thickness of 0.25 mm or less along the flat plate portion 1b of the gasket 1 The explosion-proof thin wall in which the pressure generated by the gas is concentrated, protrudes so as to expand outward, is broken by contact with the protrusion 11, and the gas existing in the battery case 8 at high pressure is broken by the protrusion 11. The gap can be efficiently discharged using the gap between the portion 1c and the protruding portion 11.

  In addition, in the height direction of the cylinder, by sealing the opening with the sealing body 4 using the thin gasket 1, the space necessary for the explosion-proof thin portion 1c to extend can be minimized. As a result, the gasket 1 constituting the sealing body 4 can be thinned, the internal volume can be increased, and the battery capacity of the alkaline manganese dry battery can be increased.

  Next, FIG. 2 is a schematic cross-sectional view of the fractured state of the explosion-proof thin portion 1c of the sealing body 4 in the embodiment of the present invention. As shown in FIG. 2, there are a projection 11 having a sharp tip formed by plastic working on the back surface of the bottom plate 3 and a machining hole 11a formed at the time of the machining, and the projection 11 breaks the explosion-proof thin portion 1c. Thus, when exhausting the internal gas, the internal gas can be efficiently exhausted through the gas flow path 13 even when the fractured explosion-proof thin-walled portion 1c and the protrusion 11 are in contact with each other. Yes.

  Next, FIG. 3 is a perspective view of the bottom plate 3 in one embodiment of the present invention. As shown in FIG. 3, the protrusion 11 formed by plastic processing on the back surface of the bottom plate 3 and the processing hole 11 a formed at the time of processing are annularly formed along the flat plate portion 1 b of the gasket 1 with respect to the center of the bottom plate 3. Plurally, it is installed so as to be opposed to the groove 1a provided, and if the exhaust at one place does not function, the explosion-proof thin part 1c is broken and compressed inside the battery when it is overdischarged. A plurality of locations for exhausting the generated gas can be secured, and exhaust can be reliably performed when the internal pressure increases.

  FIG. 4 is a perspective view of the shape of the protrusion 11 according to the embodiment of the present invention. As shown in FIG. 4, when the explosion-proof thin portion 1c is broken and the internal compressed gas is exhausted, a gas flow channel groove 13a is provided on the surface of the projection portion 11, and after the fracture, the projection portion 11 and the explosion-proof thin portion 1c are formed. Even when they are in contact with each other, the internal gas can be efficiently exhausted. Further, the gas exhausted through the gas flow path groove 13a of the protrusion 11 is discharged toward the processing hole 11a between the gas flow path grooves 13a provided in the protrusion 11 as the pressure is released during exhaust. By being able to stop the electrolyte solution of the dry battery, scattering to the outside of the dry battery can be suppressed.

  FIG. 5 is a perspective view of the shape of the protrusion 11 according to the embodiment of the present invention. As shown in FIG. 5, the gas passage slit 13b of the projection 11 is used when the explosion-proof thin portion 1c is broken and the compressed gas inside is exhausted. After the fracture, the projection 11 and the explosion-proof thin portion 1c are Even when they are in contact with each other, the internal gas can be efficiently exhausted. Further, the gas exhausted through the gas flow path slit 13b of the protrusion 11 is directed toward the machining hole 11a along with the pressure release during exhaust between the arrangement distance of the gas flow path slit 13b of the protrusion 11. Since the electrolyte solution of the discharged dry battery can be stopped, scattering to the outside of the dry battery can be suppressed.

  FIG. 6 is a perspective view of the shape of the protrusion 11 according to the embodiment of the present invention. As shown in FIG. 6, when the explosion-proof thin-walled portion 1c is ruptured and the compressed gas inside is exhausted, the rough uneven portion 13c formed on the flat surface of the protruding portion 11 is used to make a protrusion after the rupture. Even when the part 11 and the explosion-proof thin part 1c are in contact with each other, the internal gas can be efficiently exhausted. In addition, the electrolyte solution of the dry battery discharged toward the processing hole 11a when the pressure is released at the time of exhausting between the unevenness of the rough surface processing of the uneven surface portion 13c of the uneven surface portion 13c formed on the flat surface of the protruding portion 11 is supplied. By being able to stop, scattering to the exterior of a dry cell can be suppressed.

FIG. 7 is a schematic diagram of an experiment for measuring the operating pressure of the explosion-proof portion in the embodiment of the present invention. As shown in FIG. 7, the internal pressure of the battery case 20 is reduced by oil sent from a hydraulic pump 19 to a hydraulic hose 16 connected to a dry battery 21 that is sealed by sealing the opening of the battery case 20 with a sealing body 14. 15M
The pressure at the time of fracture of the explosion-proof thin-walled portion 1c can be measured using the pressure sensor 15 connected to the battery case 20 by pressurizing to Pa. In order to check the pressure state, a pressure gauge 22 is connected between the hydraulic hose 16 and the hydraulic pump 19, and the pressure state is recorded using the sensor amplifier / oscilloscope 18 and is in close contact with the dry battery 21. In addition, the oil discharged into the scattering amount measuring tank 17 can be measured. Examples of the present invention will be described below.

  As shown in FIG. 1, the thickness of the explosion-proof thin part 1c is set to 0.25 mm, and the bottom plate 3 is substantially perpendicular to the explosion-proof thin part 1c and has a sharp tip with a length of 3 mm in the annular direction. An alkaline manganese dry battery provided with the protrusions 11 was taken as Example 1.

  An alkaline manganese dry battery having the same specification as that of Example 1 and having only the length of the protrusion 11 increased by 5 mm and the length of the breaking distance reduced by 2 mm was taken as Example 2.

  An alkaline manganese dry battery having the same specification as that of Example 1 and having a plurality of four protrusions 11 provided therein was designated as Example 3.

  As shown in FIG. 4, an alkaline manganese dry battery having the same specifications as in Example 1 and having a gas flow channel groove 13 a in the protruding portion 11 was taken as Example 4.

  As shown in FIG. 5, an alkaline manganese dry battery having the same specifications as in Example 1 and having a gas flow path slit 13 b in the protrusion 11 was taken as Example 5.

  As shown in FIG. 6, an alkaline manganese dry battery having the same specifications as in Example 1 and having protrusions 11 provided with continuous irregularities 13 c by roughening was used as Example 6.

(Comparative Example 1)
In order to compare with the example of the present invention, the same specification as that of Example 1 and the base plate 3 not including the protruding portion 11 was used as Comparative Example 1.

(Comparative Example 2)
A comparative example 2 having the same specifications as in Example 1 and having no gas flow path 13 provided in the protrusion 11 of the bottom plate 3 was used.

  Using the dry battery 21 sealed in the opening of the battery case 20 with the sealing body 14 shown in the examples and comparative examples as described above, the battery is connected to the dry battery 21 using an experimental apparatus as shown in FIG. The internal pressure of the battery case 20 is increased to 15 MPa with oil sent from the hydraulic pump 19 through the hydraulic hose 16, and the pressure sensor 15 connected to the battery case 20 is used to break the explosion-proof thin portion 1c. Measure to compare pressures.

In addition, the state is recorded using the sensor amplifier / oscilloscope 18, and the oil discharged into the scattering amount measuring tank 17 in close contact with the gasket 1 is measured, and the explosion-proof thin-walled portion 1 c is broken when the internal pressure increases. Measurements were made to compare the pressure and the amount of scattering. The alkaline manganese dry batteries of Examples 1 to 6 and Comparative Examples 1 and 2 were measured, the pressure at the time of rupture of each explosion-proof thin-walled portion 1c was measured, and the results and the amount of oil scattered at the time of rupture are shown in (Table 1). Show.

  As is clear from Table 1, Examples 1 to 6 of the present invention can break the explosion-proof thin-walled portion 1c that performs explosion-proof operation under the same conditions at a lower pressure than Comparative Examples 1 and 2. In addition, even in the amount of scattering, since Examples 1 to 6 are less than the amount of oil scattered in the high pressure state as in Comparative Examples 1 and 2, the amount of scattering decreases with the breakage in the low pressure state. It is possible to greatly suppress and improve the scattering of oil discharged by Moreover, the distance for the explosion-proof thin-walled portion 1c to be broken is shortened by changing the length of the protruding portion 11 as in the second embodiment, and the ultimate pressure at which the sharp protruding portion 11 is quickly broken is broken. It is possible to significantly reduce the amount of oil scattered due to breakage and to improve it.

  Furthermore, by installing a plurality of protrusions 11 as in the third embodiment, the number of discharge ports is increased, and it is possible to significantly suppress and improve the scattering of oil discharged due to breakage. Further, by performing the groove processing on the protruding portion 11 as in the fourth embodiment, it becomes possible to restrain the discharged oil by the groove formed by the groove processing as compared with the planar state of Comparative Examples 1 and 2. In addition, it is possible to suppress the amount of scattering due to the breakage, and it is possible to significantly suppress and improve oil scattering. Further, by slitting the protrusion 11 as in the fifth embodiment, compared to the planar state of the first and second comparative examples, a slit formed by slitting the oil discharged from the fourth embodiment. It is possible to stop by the wall between the arrangements of the two, respectively, it becomes possible to suppress the amount of scattering due to breakage, and it is possible to greatly suppress and improve the oil scattering.

Finally, by roughening the projection 11 as in the fifth embodiment, the oil discharged from the fourth and fifth embodiments is further roughened as compared to the planar states of the first and second comparative examples. Therefore, it can be restrained by the concavo-convex portion 13c formed on the flat surface of the protruding portion 11, and it becomes possible to suppress the amount of scattering due to breakage, respectively, and it is possible to significantly suppress and improve oil scattering. In the measurement for comparison, oil is supplied into the battery case 20 to configure the dry battery 21 and the amount of scattering is measured by breakage due to hydraulic pressure. Examples 1 to 6 and comparison Experiments have confirmed that the alkaline manganese dry batteries of Examples 1 and 2 correspond to the amount of electrolyte scattered during overdischarge. Moreover, in the measurement for the comparison, the alkaline manganese battery has been described as a representative, but the same effect can be obtained by adopting the same configuration in the nickel manganese battery.

  According to the present invention, the power generation member in which the positive electrode mixture and the negative electrode agent are arranged to face each other with the separator interposed therebetween is housed in the battery case, and the opening of the battery case is formed in a part of the gasket made of the bottom plate and the insulating material. An exhaust path to the outside is provided by an alkaline manganese dry battery characterized in that a groove portion is provided on the side to provide an explosion-proof thin wall portion, and a protrusion cut from the bottom plate is provided at a position corresponding to the explosion-proof thin wall portion of this gasket. The gas generated inside can be efficiently discharged to the outside, and the occupied volume of the sealing body can be reduced, and the opening of the dry battery is sealed by the sealing body. By expanding the internal volume, it is possible to increase the battery capacity, and it is possible to extend the life of the alkaline manganese battery.

Half sectional view of an alkaline manganese battery in an embodiment of the present invention Cross-sectional schematic diagram of the exhaust state when the explosion-proof thin-walled portion in one embodiment of the present invention is broken The perspective view of the baseplate in one embodiment of this invention The perspective view which shows the shape of the projection part of the sealing body in one embodiment of this invention The perspective view which shows the shape of the projection part of the sealing body in one embodiment of this invention The perspective view which shows the shape of the projection part of the sealing body in one embodiment of this invention Schematic diagram of the explosion-proof operating pressure measurement experiment in the same example Half sectional front view of an alkaline manganese dry battery in the conventional example Sectional view of the sealing body in the conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gasket 1a Groove part 1b Flat plate part 1c Explosion-proof thin part 1d Bottom wall part 2 Negative electrode collector 3 Bottom plate 4 Sealing body 5 Negative electrode agent 6 Positive electrode mixture 7 Separator 8 Battery case 9 Exterior label 10 Insulation cap 11 Protrusion part 11a Processing hole 13 Gas flow path 13a Gas flow path groove 13b Gas flow path slit 13c Concavity and convexity 14 Sealing body 15 Pressure sensor 16 Hydraulic hose 17 Scattering amount measuring tank 18 Sensor amplifier and oscilloscope 19 Hydraulic pump 20 Battery case 21 Dry cell 22 Pressure gauge

Claims (7)

  A power generation member in which a positive electrode mixture and a negative electrode agent are disposed opposite to each other with a separator interposed therebetween is housed in the battery case, and the opening of the battery case is sealed with a sealing body including a bottom plate and a gasket made of an insulating material. In the dry battery, a groove part is provided on the power generation member side of the gasket to form an explosion-proof thin part, and a protruding part cut from the bottom plate is provided at a position corresponding to the explosion-proof thin part of the gasket.   The dry battery according to claim 1, wherein a plurality of the protrusions are provided corresponding to the explosion-proof thin-walled parts.   The dry battery according to claim 1, wherein a tip of the protrusion is sharpened.   2. The dry battery according to claim 1, wherein a gas flow path is provided to allow gas to pass even when the explosion-proof thin-walled portion of the gasket is in close contact with the protruding portion.   The dry battery according to claim 4, wherein the gas flow path is a groove formed on a surface of the protrusion. The dry battery according to claim 4, wherein the gas flow path is a slit formed in the height direction of the protrusion.   The dry battery according to claim 4, wherein the gas path is a rough surface formed by a rough surface process formed on the surface of the protrusion.

Images