JPH0338700B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to the improvement of cylindrical alkaline batteries that use metal oxides such as manganese dioxide, silver oxide, mercury oxide, and nickel oxide as positive electrode active materials, and allows gas to be quickly released to the outside when the pressure inside the battery increases abnormally. The purpose of the present invention is to provide a highly safe cylindrical alkaline battery that prevents the battery from bursting due to an abnormal increase in internal pressure. Because alkaline batteries use a strong alkali as an electrolyte, a large amount of gas is suddenly generated, which can cause the pressure inside the battery to become abnormally high. Therefore, the synthetic resin sealing body that seals the opening of the positive electrode can is partially thinned as shown in Fig. 4, so that when the pressure inside the battery increases abnormally, the thinned part 63b ruptures. Safety measures are taken to prevent the battery from exploding and the electrolyte from scattering by allowing the gas to escape to the outside. However, it is extremely difficult to form a very small sealing body so thin that it can be partially ruptured by a constant gas pressure, resulting in variations in thickness.
There are problems such as not breaking at the set pressure, causing danger, or breaking at a pressure lower than the set pressure, making it unusable. The present invention has been made to solve such problems, and includes a thick wall portion centered around the through hole through which the negative electrode lead rod is inserted, and a thick outer peripheral edge portion in contact with the opening peripheral wall of the positive electrode can. and a connecting portion connecting the thick wall portion and the outer peripheral edge, an annular support is inserted between the thick wall portion and the outer peripheral edge, and a negative electrode lead rod is inserted into the through hole. In cylindrical alkaline batteries, the opening of the positive electrode can is sealed with The part around the through hole and other parts of the flesh part are molded separately, and the part around the through hole is formed into a tapered cylinder whose outer peripheral surface gradually decreases in diameter as it faces toward the power generation element.
The other portions are molded integrally with the outer peripheral edge and the connecting portion, and the inner peripheral surface thereof is formed into a tapered shape whose diameter gradually decreases in correspondence with the outer peripheral surface of the peripheral portion of the through hole. By inserting the small-diameter end into the other parts to form the thick wall part of the sealing body, when the pressure inside the battery reaches the set pressure, the through-hole part of the sealing body rises and the other parts The present invention provides a cylindrical alkaline battery that is highly safe against abnormal explosion of the battery by creating gaps between the parts and releasing the internal gas to the outside. Next, embodiments of the present invention will be described based on the drawings. FIG. 1 is a partial sectional view showing one embodiment of the cylindrical alkaline battery of the present invention, and FIG. 2 is an enlarged sectional view of a sealing body used in the battery shown in FIG. 1. First, to explain the sealing body, the sealing body 6 has a thick wall portion 61 centered around the through hole 64 through which the negative electrode lead rod 5 is inserted, and an annular shape that is in contact with the inner peripheral surface of the opening peripheral wall of the positive electrode can 4. thick outer peripheral edge 6
2, and a connecting part 63 having a V-shaped part 63a and connecting the thick part 61 and the outer peripheral edge part 62,
A ventilation hole 7 is provided between the thick portion 61 and the outer peripheral edge portion 62.
An annular support 7 made of iron is inserted. The hole surrounding portion 6a of the thick wall portion 61 of the sealing body 6 is formed separately from the other portion 6b, that is, the portion of the thick wall portion 61 other than the hole surrounding portion 6a. The portion 6a is formed into a tapered cylindrical body whose outer peripheral surface 6c (see FIG. 3) gradually decreases in diameter as it goes toward the power generating element side (that is, as it goes toward the bottom in the drawing),
The other portions 6b are the outer peripheral edge 62 and the connecting portion 6.
3, and its inner circumferential surface 6d is formed into a tapered shape whose diameter gradually decreases toward the power generating element side, corresponding to the outer circumferential surface 6c of the through-hole peripheral portion 6a. In use, the through-hole peripheral portion 6a is inserted into the other portion 6b from its small diameter side, thereby forming the thick wall portion 61 and completing the sealing body 6. Figure 1 shows a cylindrical alkaline battery using the sealing body 6 as described above, in which 1 is a positive electrode mixture whose main ingredient is manganese dioxide, 2 is a negative electrode material whose active material is amalgamated zinc, and 3 is a positive electrode. Mixture 1 and negative electrode agent 2
4 is a positive electrode can, and 4a is a separator provided near the opening end of the positive electrode can to receive the sealing body 6 inserted into the opening of the positive electrode can 4. One end of the outer peripheral edge 62 of the sealing body 6 to which the annular support 7 and the negative electrode lead rod 5 are attached as described above comes into contact with the bottom wall of this groove 4a, and in this state, the positive electrode can 4 is closed. The portion beyond the groove 4a is tightened inward and curved, and its inner circumferential surface is pressed against the outer circumferential edge 62 of the sealing body 6, so that the opening of the positive electrode can 4 is sealed. 8 is a negative electrode terminal plate; 9 is a leaf spring disposed between the negative electrode lead rod 5 and the negative electrode terminal plate 8;
The head of the negative electrode lead rod 5 is pressed downward in the axial direction at the center thereof, and its end portion is held between the insulating ring 10 and the peripheral edge of the negative electrode terminal portion 8 . The insulating ring 10 is placed on the open end of the positive electrode can 4 and insulates the positive electrode can 4 and the negative terminal plate 8. In the areas intervening between the periphery,
The leaf spring 9 and the positive electrode can 4 are insulated, and the end of the leaf spring 9 is clamped and fixed by the peripheral edge of the negative terminal plate 8. 11 is a resin tube, 12 is a positive electrode terminal plate, 13 is a metal outer can, and 14 and 15 are resin rings. It covers the outer peripheral surface, the peripheral edge of the negative terminal plate 8, and the peripheral edge of the positive terminal plate 12. The resin ring 14 is arranged above the upper end of the resin tube 11, and the resin ring 15 is arranged below the lower end of the resin tube 11. The above metal exterior can 13
is arranged on the outside of the resin tube 11, and its upper end portion tightens the resin ring 14 downward in the axial direction, and its lower end portion tightens the resin ring 15 upward in the axial direction. The contact surface between the sealing body 6 and the negative electrode lead rod 5, the contact surface between the sealing body 6 and the positive electrode can 4, the portion 6a around the through hole of the sealing body 6, and other portions 6.
A liquid packing material made of asphalt pitch (for example, a mixture of blown asphalt and process oil) is interposed on the surface in contact with b. However, if the internal pressure inside the battery becomes abnormally high due to abnormal gas generation, etc., this battery
As shown in the figure, the portion 6a surrounding the through hole of the thick portion 61 of the sealing body 6 rises together with the negative electrode lead rod 5 overcoming the downward axial pressing force of the leaf spring 9. On the other hand, the other portions 6b include the outer peripheral edge 62 and the connecting portion 6.
3, and the outer peripheral edge part 62 is fixed by inward tightening of the part beyond the groove 4a of the positive electrode can 4 and does not rise, so that the peripheral part 6a of the through hole and the other part 6b are There is a gap between
Gas generated inside the battery quickly escapes from the sealing body 6 through this gap. The gas released into the sealing body 6 in this way passes between the positive electrode can 4 and the insulating ring 10 or between the peripheral edge of the negative terminal plate 8 and the insulating ring 10, and then passes through the resin tube 11 and the negative terminal plate 8.
If necessary, by providing a gas vent hole in the negative electrode terminal plate 8, the gas can be released to the outside of the battery through a gap between the gas and the peripheral edge of the battery. In the present invention, various synthetic resins such as polyethylene, polypropylene, and nylon can be used as the sealing body 6. The hole surrounding portion 6a and the other portions 6b may be made of the same material, or may be made of different resins, such as the hole surrounding portion 6a being made of nylon 6 and the other portion 6b being made of polypropylene. may be formed. The following Table 1 shows the battery A of the present invention having the configuration shown in FIG. 1 and the conventional battery B using the sealing member shown in FIG. 4, in which the pressure and gas inside the battery are released to the outside. This study investigated the relationship with the number of items. The batteries are all LR20-type cylindrical alkaline manganese batteries, and the number of samples tested was 100 each for batteries A and B. The test was conducted by charging each battery and forcibly generating gas, and then increasing the internal pressure to a specified pressure. The number of batteries in which gas was released to the outside when the temperature was increased was investigated.

[Table] As shown in Figure 1, in conventional battery B, the pressure at which gas is discharged to the outside varies considerably.
In the case of battery A of the present invention, such variations are small.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing one embodiment of the cylindrical alkaline battery of the present invention, and FIG. 2 is an enlarged sectional view of a sealing body used in the battery shown in FIG. 1. Third
The figure is a partially enlarged cross-sectional view to explain the state in which gas inside the battery is released to the outside when the internal pressure of the battery shown in Figure 1 rises. Figure 4 is a cross-sectional view showing the sealing body of a conventional battery. be. 1... Positive electrode mixture, 2... Negative electrode material, 3... Separator, 4... Positive electrode can, 5... Negative electrode lead rod, 6...
...Sealing body, 6a... Portion around the hole, 6b... Other parts, 6c... Outer peripheral surface of the portion around the hole, 6d
... Inner peripheral part of other parts, 61 ... Thick wall part, 6
2... Outer peripheral edge portion, 63... Connection portion, 64... Through hole, 7... Annular support, 8... Negative electrode terminal plate, 9...
... leaf spring, 10 ... insulating ring, 11 ... resin tube, 12 ... positive terminal plate, 13 ... metal exterior can, 14 ... resin ring, 15 ... resin ring.

Claims (1)

[Claims] 1. Power generation element, positive electrode can 4, and negative electrode lead rod 5
, a sealing body 6 , an annular support 7 , and a negative terminal plate 8
, leaf spring 9 , insulating ring 10 , resin tube 11 , positive terminal plate 12 , and metal exterior can 13
, a resin ring 14 , and a resin ring 15 , the power generation element includes a positive electrode mixture 1 , a negative electrode mixture 2 ,
The sealing body 6 has a separator 3 , and the sealing body 6 has a thick portion 61 , a thick outer peripheral edge 62 , a connecting portion 63 , and a through hole 64 , the through hole 64 being located at the center of the sealing body 6 The thick part 61 is arranged around the through hole 64, and the connecting part 63 is connected to the thick part 61 and the outer peripheral edge part 62.
The thick part 61 of the sealing body 6 connects the through-hole peripheral part 6.
a and another portion 6b, and the through-hole surrounding portion 6a of the thick walled portion 61 is molded separately from the other portion 6b, and its outer circumferential surface 6c gradually moves toward the power generating element side. The other portion 6b of the thick wall portion 61 is formed integrally with the outer peripheral edge portion 62 and the connecting portion 63, and the inner peripheral surface 6d thereof is formed into a tapered cylinder whose diameter is reduced. Outer peripheral surface 6c of peripheral portion 6a
The through hole peripheral portion 6a is inserted into the other portion 6b from its small diameter end, and the through hole peripheral portion 6a is inserted into the other portion 6b from the end on the small diameter side. The element is housed in the positive electrode can 4, the negative electrode lead rod 5 is inserted into the through hole 64 of the sealing body 6, and the annular support body 7 is connected to the thick part 61 and the outer peripheral edge 62 of the sealing body 6. The opening of the positive electrode can 4, which is inserted between the
As described above, the negative electrode lead rod 5 is inserted, the annular support 7 is inserted into the sealing body 6, and the opening peripheral wall of the positive electrode can 4 is tightened inward to cover the inner peripheral surface of the sealing body 6.
The insulating ring 10 is placed on the open end of the positive electrode can 4, and the leaf spring 9 is connected to the negative electrode lead rod 5 at its center.
The head of the is pressed downward in the axial direction, and its end is held between the insulating ring 10 and the peripheral edge of the negative terminal plate 8, and the positive terminal plate 12 is disposed at the lower part of the positive electrode can 4, and the The resin tube 11 is connected to the outer peripheral surface of the positive electrode can 4,
The resin ring 14 covers the peripheral edge of the negative terminal plate 8 and the peripheral edge of the positive terminal plate 12, and the resin ring 15 is disposed above the upper end of the resin tube 11. The metal exterior can 13 is arranged at the bottom of the resin tube 11.
A cylindrical alkaline battery, characterized in that a resin ring 14 is tightened axially downward at its upper end, and a resin ring 15 is tightened axially upward at its lower end.