JP5114004B2 - Cylindrical battery - Google Patents

Description

  The present invention relates to a cylindrical alkaline battery in which an explosion-proof valve function is installed in a positive terminal portion.

  For example, as shown in FIG. 4, the LR type cylindrical alkaline battery has an inside-out type structure, accommodates the power generation element 20 in a bottomed cylindrical metal positive electrode can 11, and The opening is sealed using a negative electrode terminal plate 33 and a gasket 351.

  The power generation element 20 includes a cylindrical positive electrode mixture 21 press-fitted into the positive electrode can 11, a separator 22 loaded inside the positive electrode mixture 21, and a gelled negative electrode mixture filled inside the separator. 23. The positive electrode can 11 also serves as a positive electrode current collector. In addition, a base end of a rod-shaped negative electrode current collector 31 penetrating into the negative electrode mixture 23 is connected to the inner side (battery inner side) of the negative electrode terminal plate 33 by welding or the like.

  This type of alkaline battery is provided with an explosion-proof valve function for preventing the battery from bursting in preparation for a case where gas is generated inside the battery due to misuse or the like and the battery internal pressure rises abnormally. This explosion-proof valve function can be formed in the gasket. That is, a thin portion that is easy to break is provided in a part of the gasket, and when the internal pressure of the battery rises for maintenance, the thin portion is preliminarily broken so that the gas inside the battery is released before the battery bursts.

  However, the degassing operation of the explosion-proof valve function formed on this gasket is irreversible and cannot be restored to its original state once it is activated. That is, since explosion-proofing is performed by destroying the gasket seal, once the explosion-proof battery is operated, it cannot be reused.

  Therefore, as shown in FIG. 4, it has been proposed to provide an explosion-proof valve function that can be used repeatedly on the positive electrode terminal side (see, for example, Patent Document 1). In the cylindrical alkaline battery 101 shown in the figure, a positive electrode terminal plate 55 is welded to the outer bottom surface of the positive electrode can 11. The positive electrode terminal plate 55 is formed so as to cover almost the entire outer bottom surface of the positive electrode can 11, and the convex positive electrode terminal portion 13 is integrally formed by pressing at the center thereof.

  A valve port 111 is formed at the center of the bottom of the positive electrode can 11, and a valve seat 112 for seating the rubber-like elastic valve element 61 is formed around the valve port 111. The rubber-like elastic valve element 61 is seated on the valve seat 112 while closing the valve port 111 from the outside. The positive electrode terminal plate 55 is welded to the outer bottom surface of the positive electrode can 11 with the elastic valve body 61 pressed against the valve seat portion 112. A gas vent hole 511 is provided in a side portion of the positive electrode terminal portion 13.

  In the above-described cylindrical alkaline battery 101, gas is generated inside the battery due to misuse or the like, and when the internal pressure of the battery rises due to this gas generation, the elastic valve body 61 is elastically deformed (including elastic contraction) by the internal pressure of the battery. Thus, a gas vent passage (gap) is formed between the valve body 61 and the valve seat portion 112. As a result, the high-pressure gas inside the battery is released to the outside through the gas vent hole 511, and the battery is prevented from bursting.

Thereafter, when the battery internal pressure falls to the safe range, the elastic valve body 61 is elastically restored and returns to the original state of closing the valve port 111. As described above, since the explosion-proof valve function operates reversibly, even after the explosion-proof valve function is activated, the battery can be used repeatedly if the cause of the operation is eliminated.
JP 2001-76701 A

  As shown in FIG. 4, the conventional cylindrical alkaline battery 101 described above has an explosion-proof valve function between the outer bottom surface of the positive electrode can 11 and the positive electrode terminal plate 55 covering almost the entire outer bottom surface. ing. The positive electrode terminal plate 55 is welded to the outer bottom surface of the positive electrode can 11 in a state where the elastic valve body 61 is pressed against the outer bottom surface of the positive electrode can 11, but there is a problem that the welded portion is easily detached. .

  Regarding this problem, the present inventor has revealed the following problem. That is, the outer bottom surface of the positive electrode can 11 is not necessarily a mechanically stable surface. For example, when a load is applied due to a mechanical impact caused by dropping of a battery or the like, or some other load, the outer bottom surface is slightly Elastic deformation (deflection) occurs temporarily. It has been found that when this deformation stress is directly applied to the welded portion, the welded portion is fatigued and easily peels off.

  In addition, when welding is performed in a state where the positive electrode terminal plate 55 covers almost the entire outer bottom surface of the positive electrode can 11, the outer bottom surface of the positive electrode can 11 cannot be used as a positioning reference for processing, so that processing is not possible. It becomes stable. As a result, productivity is deteriorated and the total height of the battery 101 including the positive terminal plate 55 is likely to vary. In addition, as the machining becomes unstable, the variation in welding also increases, and this also causes the welding to be easily peeled off.

  As described above, in the conventional cylindrical alkaline battery provided with the explosion-proof valve function in the positive electrode terminal portion, because the processing conditions are unstable, the productivity is poor, the welded portion is easily detached, and the dimensional variation is large. There was a problem of poor reliability.

  The present invention solves the above problems, and its purpose is to stabilize the processing conditions and improve productivity in a cylindrical alkaline battery in which an explosion-proof valve function is installed in the positive electrode terminal portion. It is an object of the present invention to provide a cylindrical alkaline battery that can improve the reliability by making it difficult to remove the welded portion and reducing the dimensional variation.

  Other objects and configurations of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  The solution provided by the present invention is as follows.

(1) A cylindrical alkaline battery in which a power generation element is housed in a bottomed cylindrical metal positive electrode can having an opening at the top, and the opening is sealed with a negative electrode terminal plate and a gasket. And
A convex positive terminal portion is provided at the center of the outer bottom surface of the positive electrode can,
The positive electrode terminal portion is provided with a gas vent hole that communicates the inside and outside, and the internal space of the positive electrode terminal portion is activated when the internal pressure of the battery rises, and the internal pressure is reduced via the gas vent hole. An explosion-proof valve mechanism that opens,
The outer peripheral region of the outer bottom surface of the positive electrode can is located outside the central surface portion where the explosion-proof valve function is installed, and is exposed as a shoulder surface portion having a flat surface protruding downward from the central surface portion,
The explosion-proof valve mechanism is welded and installed in a state of being overlapped with the central surface portion, a valve port located in the center of the central surface portion, a valve seat portion surrounding the periphery of the valve port, and the valve port A rubber-like elastic valve body that is seated on the valve seat portion in a state where it is closed from the outside,
The bottom surface of the valve body is pressed upward by the inner bottom surface of the positive electrode terminal portion, and the outer space portion of the valve body in the internal space of the positive electrode terminal portion communicates with the outside air through the gas vent hole. Thus, when the internal pressure of the positive electrode can rises, the valve body is elastically deformed to form a gas vent path from the valve port,
The positive electrode can has an opening at the bottom center,
An intermediate reinforcing plate welded to the outer bottom surface of the positive electrode can so as to cover the central surface portion, and a positive terminal plate welded to the lower surface of the intermediate reinforcing plate to cover the central surface portion;
The positive terminal portion is formed by protruding the center of the positive terminal plate downward.
A cylindrical alkaline battery characterized by that.

(2) A cylindrical alkaline battery in which a power generation element is housed in a bottomed cylindrical metal positive electrode can having an opening on the upper side, and the opening is sealed with a negative electrode terminal plate and a gasket. And
A convex positive terminal portion is provided at the center of the outer bottom surface of the positive electrode can,
The positive electrode terminal portion is provided with a gas vent hole that communicates the inside and outside, and the internal space of the positive electrode terminal portion is activated when the internal pressure of the battery rises, and the internal pressure is reduced via the gas vent hole. An explosion-proof valve mechanism that opens,
The outer peripheral region of the outer bottom surface of the positive electrode can is located outside the central surface portion where the explosion-proof valve function is installed, and is exposed as a shoulder surface portion having a flat surface protruding downward from the central surface portion,
The explosion-proof valve mechanism is welded and installed in a state of being overlapped with the central surface portion, a valve port located in the center of the central surface portion, a valve seat portion surrounding the periphery of the valve port, and the valve port A rubber-like elastic valve body that is seated on the valve seat portion in a state where it is closed from the outside,
The bottom surface of the valve body is pressed upward by the inner bottom surface of the positive electrode terminal portion, and the outer space portion of the valve body in the internal space of the positive electrode terminal portion communicates with the outside air through the gas vent hole. Thus, when the internal pressure of the positive electrode can rises, the valve body is elastically deformed to form a gas vent path from the valve port,
The positive terminal portion is integrally formed on the bottom center surface of the positive electrode can,
A partition plate in which the valve port and the valve seat portion are formed is welded to the inner bottom surface of the positive electrode can, and the valve body is sandwiched between the positive electrode terminal portion and the partition plate. ,
A cylindrical alkaline battery characterized by that.

(3) In the above means (1) or (2), the gasket for sealing the opening of the positive electrode can is formed in an annular shape that does not form a space partition inside the negative electrode terminal plate. And a negative electrode terminal plate and at least a portion of the negative electrode current collector connected to the negative electrode terminal plate exposed to the inside of the battery is formed of the same kind of metal .

  In a cylindrical alkaline battery with an explosion-proof valve function at the positive terminal, it is possible to stabilize the processing conditions and improve productivity, making it difficult to remove the welded part and reducing dimensional variations. Thus, a cylindrical alkaline battery with improved reliability can be provided.

  Operations / effects other than those described above will be apparent from the description of the present specification and the accompanying drawings.

  FIG. 1 is a partially enlarged sectional view showing a cylindrical alkaline battery 10 according to a first embodiment of the present invention. A cylindrical alkaline battery 10 shown in the figure is configured as an LR type alkaline dry battery, and accommodates a power generation element 20 in a bottomed cylindrical metal positive electrode can 11 and an opening of the positive electrode can 11. Is sealed using a negative electrode terminal plate 33 and a gasket 35.

  The power generation element 20 includes a cylindrical positive electrode mixture 21 press-fitted into the positive electrode can 11, a separator 22 loaded inside the positive electrode mixture 21, and a gelled negative electrode mixture filled inside the separator. 23. The positive electrode can 11 also serves as a positive electrode current collector. Since the positive electrode can has excellent corrosion resistance and contact resistance, a Ni-plated steel plate or a refractory material thereof is used. Moreover, it is desirable to coat (for example, Ni plating etc.) the end surface of the steel plate which appears in the creation stage of the valve port 111 after the positive electrode can molding. In addition, a base end of a rod-shaped negative electrode current collector 31 penetrating into the negative electrode mixture 23 is connected to the inner side (battery inner side) of the negative electrode terminal plate 33 by welding.

  As the positive electrode mixture 21, a positive electrode active material such as manganese dioxide and / or nickel hydroxide to which a conductive additive such as graphite is added and pressed into a predetermined solid shape is used. Gelled zinc is used for the negative electrode mixture 23.

  The casket 35 is only an annular packing portion interposed between the crimped opening of the positive electrode can 11 and the peripheral edge portion of the negative electrode terminal plate 33, and forms a partition wall inside the negative electrode terminal plate. There is no boss. As a result, as shown in the figure, it is possible to increase the amount of the power generation material accommodated in the positive electrode can 11. That is, the volume utilization efficiency of the positive electrode can 11 is increased, and the battery capacity can be increased accordingly.

  In this case, the electrolytic solution directly contacts the inner surface of the negative electrode terminal plate 33 and the welded portion of the negative electrode current collector 31, which may cause corrosion and gas generation due to the formation of a local battery. The concern is eliminated by forming at least a portion of the negative electrode current collector 31 connected to the terminal plate 33 that is exposed inside the battery with the same kind of metal.

  In order to form the inner surface of the negative electrode terminal plate 33 with the same type of metal, the negative electrode terminal plate 33 and the negative electrode current collector 31 may be formed of the same type of metal material, or the same type of metal may be plated on the surface.

  Since the gasket 35 does not need to form a space partition inside the negative electrode terminal plate 33, the structure can be greatly simplified and the cost can be reduced. There is no need to provide a vent hole in the negative terminal plate 33. Since the negative electrode current collector 31 does not need to hermetically isolate the front end side and the base end side at the boss portion of the gasket, the degree of freedom in shape increases. Therefore, it is possible to increase the amount of the negative electrode mixture by reducing the diameter of the negative electrode current collector 31. On the other hand, since it is easy to increase the current collection efficiency by collecting the negative electrode 31 and increasing the surface area of the negative electrode 31, the design can be made according to the intended use of the battery.

  A positive terminal plate 51 is welded to the outer bottom surface of the positive electrode can 11. The positive terminal plate 51 is formed so as to cover only the central surface of the outer bottom surface of the positive electrode can 11, and the convex positive terminal portion 13 is integrally formed by pressing at the central portion.

  A valve port 111 is formed at the center of the bottom of the positive electrode can 11, and a valve seat 112 for seating the rubber-like elastic valve element 61 is formed around the valve port 111. The rubber-like elastic valve element 61 is seated on the valve seat 112 while closing the valve port 111 from the outside. The positive electrode terminal plate 51 is welded to the center of the outer bottom surface of the positive electrode can 11 with the elastic valve body 61 pressed against the valve seat 112. A gas vent hole 511 is provided in a side portion of the positive electrode terminal portion 13.

  In the cylindrical alkaline battery 10 described above, gas is generated inside the battery due to misuse or the like, and when the internal pressure of the battery rises due to this gas generation, the elastic valve body 61 is elastically deformed (including elastic contraction) by the internal pressure of the battery. Thus, a gas vent passage (gap) is formed between the valve body 61 and the valve seat portion 112. As a result, the high-pressure gas inside the battery is released to the outside through the gas vent hole 511, and the battery is prevented from bursting.

  Thereafter, when the battery internal pressure falls to the safe range, the elastic valve body 61 is elastically restored and returns to the original state of closing the valve port 111. As described above, since the explosion-proof valve function operates reversibly, even after the explosion-proof valve function is activated, the battery can be used repeatedly if the cause of the operation is eliminated.

  Here, in the cylindrical alkaline battery 10, the positive terminal plate 51 welded to the outer bottom surface of the positive electrode can 11 is formed so as to cover only the central surface of the outer bottom surface of the positive electrode can 11. The flat shoulder surface 15 at the bottom of the positive electrode can 11 is exposed outside the positive electrode terminal plate 51.

  The shoulder surface portion 15 buffers a stress caused by, for example, a mechanical shock due to a battery drop or the like, or a load caused by some other cause, directly applied to a welded portion of the positive electrode terminal plate 51. Thereby, a welding part can be made hard to come off.

  At the same time, the welding process can be stably performed with the shoulder surface portion 15 as a positioning reference. Thereby, productivity can be improved and variation in the total height of the battery 10 including the positive electrode terminal plate 51 can be reduced. Along with the stabilization of processing, the variation in welding also becomes smaller, and welding peeling is more unlikely to occur. Thereby, reliability can be improved significantly.

  As a material for the rubber-like elastic valve body 61, for example, ethylene / propylene rubber (EPM, EPDM), which is a synthetic rubber, is excellent in heat resistance and chemical resistance and can be suitably used. In addition, materials not classified as synthetic rubbers, for example, closed-cell foams of resin can be used. As the shape of the valve body 61, a cylindrical shape is used in the embodiment, but a hat shape, a rectangular shape, or the like can also be used.

  It is also desirable to apply a sealant (for example, a pitch-type sealant) between the valve body 61 and the positive terminal plate 51 in order to make the sealing function in a steady state where the explosion-proof valve function is inactive.

  By adhering a gas permeable film (craze material or the like) or the like to the surface of the valve body 61 that is seated on the valve seat 112, or by physically sandwiching the valve body 61, only the gas is allowed to escape selectively at normal times. The pressure rise in the battery can be reduced. In this case, since the explosion-proof valve function is activated only in response to a sudden rise in battery internal pressure, the activation frequency is reduced. Thereby, the leakage frequency of the electrolyte solution accompanying the operation of the explosion-proof valve function can be reduced.

  FIG. 2 is an enlarged cross-sectional view showing a main part of the cylindrical alkaline battery 10 according to the second embodiment of the present invention. If it demonstrates paying attention to the difference with embodiment mentioned above, in embodiment shown in the figure, the intermediate reinforcement board 52 between the outer bottom face of the positive electrode can 11 and the positive electrode terminal board 51 in which the positive electrode terminal part 13 was formed. And a valve opening 521 and a valve seat portion 522 are formed in the intermediate reinforcing plate 52.

  An opening 113 that is slightly larger than the valve opening 521 of the intermediate reinforcing plate 52 is formed in the positive electrode can 11, and the valve opening 521 overlaps the inside of the opening 113.

  In this embodiment, it is possible to reliably prevent the bottom portion of the positive electrode can 11 from being deformed and biting into the valve body 61 when the battery internal pressure suddenly rises, thereby facilitating the operation of the explosion-proof valve function. Reliability can be greatly increased.

  FIG. 3 is an enlarged cross-sectional view showing a main part of the cylindrical alkaline battery 10 according to the third embodiment of the present invention. If it demonstrates paying attention to difference with embodiment mentioned above, in embodiment shown in the figure, while partitioning plate 53 in which valve mouth 531 and valve seat part 532 were formed is welded and joined to the inner bottom face of positive electrode can 11, A rubber-like elastic valve element 61 is sandwiched between the convex positive terminal portion 13 integrally formed on the bottom center surface of the positive electrode can 11 and the partition plate 53.

  In this embodiment. Since the positive electrode terminal portion 13 is integrally formed with the positive electrode can 11 by press working, there is an advantage that the positive electrode terminal portion 13 is not detached by welding peeling. In addition, since the entire outer bottom surface of the positive electrode can 11 can be used as a positioning reference during processing, the processing stability is also good. Further, since the positive electrode terminal portion 13 is integrally formed on the outer bottom surface of the positive electrode can 11, an advantage that the appearance of the battery can be improved is obtained.

  As mentioned above, although this invention was demonstrated based on the typical Example, this invention can have various aspects other than having mentioned above. For example, the valve port may be formed by a plurality of opening holes. In the illustrated embodiment, the valve seat portion is shown as a flat valve seat portion. However, if the explosion-proof valve function is a structure capable of maintaining a sealing function in a steady state in a non-operating state, the valve seat portion is an elastic valve. It may be curved or bent toward the body.

  In a cylindrical alkaline battery with an explosion-proof valve function at the positive terminal, it is possible to stabilize the processing conditions and improve productivity, making it difficult to remove the welded part and reducing dimensional variations. Thus, a cylindrical alkaline battery with improved reliability can be provided.

It is a partially expanded sectional view which shows the outline | summary of the cylindrical alkaline battery by 1st Embodiment of this invention. It is an expanded sectional view which shows the principal part of the cylindrical alkaline battery by 2nd Embodiment of this invention. It is an expanded sectional view which shows the principal part of the cylindrical alkaline battery by 3rd Embodiment of this invention. It is a partially expanded sectional view which shows the outline | summary of the conventional cylindrical alkaline battery.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cylindrical alkaline battery 11 Positive electrode can 111 Valve port 112 Valve seat part 113 Opening part 13 Positive electrode terminal part 15 Shoulder surface part 20 Power generation element 21 Positive electrode mixture 22 Separator 23 Gel-like negative electrode mixture 31 Negative electrode current collector 33 Negative electrode terminal plate 35 Gasket 51 Positive electrode terminal plate 511 Gas vent hole 52 Intermediate reinforcing plate 521 Valve port 522 Valve seat portion 53 Partition plate 531 Valve port 532 Valve seat portion 61 Elastic valve body

Claims (3)

A cylindrical alkaline battery in which a power generation element is accommodated in a bottomed cylindrical metal positive electrode can having an opening on the upper side, and the opening is sealed using a negative electrode terminal plate and a gasket,
A convex positive terminal portion is provided at the center of the outer bottom surface of the positive electrode can,
The positive electrode terminal portion is provided with a gas vent hole that communicates the inside and outside, and the internal space of the positive electrode terminal portion is activated when the internal pressure of the battery rises, and the internal pressure is reduced via the gas vent hole. An explosion-proof valve mechanism that opens,
The outer peripheral region of the outer bottom surface of the positive electrode can is located outside the central surface portion where the explosion-proof valve function is installed, and is exposed as a shoulder surface portion having a flat surface protruding downward from the central surface portion,
The explosion-proof valve mechanism is welded and installed in a state of being overlapped with the central surface portion, a valve port located in the center of the central surface portion, a valve seat portion surrounding the periphery of the valve port, and the valve port A rubber-like elastic valve body that is seated on the valve seat portion in a state where it is closed from the outside,
The bottom surface of the valve body is pressed upward by the inner bottom surface of the positive electrode terminal portion, and the outer space portion of the valve body in the internal space of the positive electrode terminal portion communicates with the outside air through the gas vent hole. Thus, when the internal pressure of the positive electrode can rises, the valve body is elastically deformed to form a gas vent path from the valve port,
The positive electrode can has an opening at the bottom center,
An intermediate reinforcing plate welded to the outer bottom surface of the positive electrode can so as to cover the central surface portion, and a positive terminal plate welded to the lower surface of the intermediate reinforcing plate to cover the central surface portion;
The positive terminal portion is formed by protruding the center of the positive terminal plate downward.
A cylindrical alkaline battery characterized by that. A cylindrical alkaline battery in which a power generation element is accommodated in a bottomed cylindrical metal positive electrode can having an opening on the upper side, and the opening is sealed using a negative electrode terminal plate and a gasket,
A convex positive terminal portion is provided at the center of the outer bottom surface of the positive electrode can,
The positive electrode terminal portion is provided with a gas vent hole that communicates the inside and outside, and the internal space of the positive electrode terminal portion is activated when the internal pressure of the battery rises, and the internal pressure is reduced via the gas vent hole. An explosion-proof valve mechanism that opens,
The outer peripheral region of the outer bottom surface of the positive electrode can is located outside the central surface portion where the explosion-proof valve function is installed, and is exposed as a shoulder surface portion having a flat surface protruding downward from the central surface portion,
The explosion-proof valve mechanism is welded and installed in a state of being overlapped with the central surface portion, a valve port located in the center of the central surface portion, a valve seat portion surrounding the periphery of the valve port, and the valve port A rubber-like elastic valve body that is seated on the valve seat portion in a state where it is closed from the outside,
The bottom surface of the valve body is pressed upward by the inner bottom surface of the positive electrode terminal portion, and the outer space portion of the valve body in the internal space of the positive electrode terminal portion communicates with the outside air through the gas vent hole. Thus, when the internal pressure of the positive electrode can rises, the valve body is elastically deformed to form a gas vent path from the valve port,
The positive terminal portion is integrally formed on the bottom center surface of the positive electrode can,
A partition plate in which the valve port and the valve seat portion are formed is welded to the inner bottom surface of the positive electrode can, and the valve body is sandwiched between the positive electrode terminal portion and the partition plate. ,
A cylindrical alkaline battery characterized by that. 3. The gasket according to claim 1, wherein the gasket for sealing the opening of the positive electrode can is formed in an annular shape that does not form a space partition inside the negative electrode terminal plate, thereby directly exposing the inner surface of the negative electrode terminal plate to the inside of the battery. A cylindrical alkaline battery characterized in that a negative electrode terminal plate and at least a portion of a negative electrode current collector connected to the negative electrode terminal plate, which is exposed inside the battery, are formed of the same kind of metal .

Images