Alkaline dry cell

Abstract

The present invention discloses an alkaline dry cell with a high capacity having a superior liquid leak resistant property. In this alkaline dry cell, the thickness of the trunk portion of an external can is made thinner than 0.18 mm, and the thickness of the sealing edge portion of the external can is set to not less than 1.4 times the thickness of trunk portion. An anode terminal plate is used as a supporting member for a sealing member. Over the entire outer circumferential portion of the anode terminal plate is placed a curved portion having an average curvature radius of not more than 1 mm, which shows a virtually C-letter shape or an arc shape in its cross-section obtained by cutting the anode terminal plate through its center in the thickness direction. By providing a structure for supporting the sealing member by this curved portion with the inner circumferential side, the sealing edge portion is allowed to have a sufficient strength, and it is possible to ensure a superior liquid leak resistant property and also to increase the buttery inner volume. Moreover, the anode terminal plate has a structure including a terminal face formed in a protruding shape on the center and an outer circumferential flange face formed in a manner so as to surround the terminal face when viewed in a direction penetrating this terminal face vertically, and a flat portion that is not in parallel with the terminal face is placed on the inner circumferential side of the flange face. In the connecting portion of the sealing member, an anti-explosion thin portion is placed on the foot portion on the side of a boss section, and on the foot portion of the outer circumferential portion side, a stress absorbing section for absorbing one portion of a stress that is exerted on the connecting portion at the time of a lateral tightening sealing edge process.

What is claimed is:  
     
         1 . An alkaline dry cell comprising: 
 a cathode and an anode, a separator placed between said cathode and said anode and an electrolyte solution that are housed inside an external can having a cylindrical shape with a bottom, and a resin sealing member and a supporting member for supporting said sealing member with the inner circumferential portion that are attached to an opening edge of the external can,    wherein the opening edge of the external can is sealed by tightening the resin sealing member with the external can and the supporting member,    wherein the thickness of a trunk portion of the external can is made thinner than 0.18 mm, and the thickness of the sealing edge portion of the external can is made 1.4 times greater than the thickness of the trunk portion.    
     
     
         2 . An alkaline dry cell comprising: 
 a cathode and an anode, a separator placed between said cathode and said anode and an electrolyte solution that are housed inside an external can having a cylindrical shape with a bottom, and a resin sealing member and a supporting member for supporting said sealing member with the inner circumferential portion that are attached to an opening edge of the external can,    wherein the opening edge of the external can is sealed by tightening the resin sealing member with the external can and the supporting member,    wherein a sheet of metal plate that also serves as an anode terminal plate is used as the supporting member,    wherein along all the outer circumferential portion of the metal plate, as a portion for sandwiching the resin sealing member together with the external can, a curved portion, which has an average curvature radius of not more than 1 mm in a cross-section obtained when the metal plate is cut in the thickness direction through the center thereof, is installed.    
     
     
         3 . An alkaline dry cell comprising: 
 a cathode and an anode, a separator placed between said cathode and said anode and an electrolyte solution that are housed inside an external can having a cylindrical shape with a bottom, and a resin sealing member and a supporting member for supporting said sealing member with the inner circumferential portion that are attached to an opening edge of the external can,    wherein the opening edge of the external can is sealed by tightening the resin sealing member with the external can and the supporting member,    wherein a sheet of metal plate that also serves as an anode terminal plate is used as the supporting member,    wherein along all the outer circumferential portion of the metal plate, as a portion for sandwiching the resin sealing member together with the external can, a curved portion, which has an average curvature radius of not more than 1 mm in a cross-section obtained when the metal plate is cut in the thickness direction through the center thereof and which is formed in a curved manner over an angle range greater than 90 degrees, is installed.    
     
     
         4 . The alkaline dry cell according to  claim 2  or  claim 3 , wherein the curved portion is maintained in contact with the resin sealing member within an angle range greater than 90 degrees in a cross-section obtained when the metal plate is cut in the thickness direction through the center thereof.  
     
     
         5 . An alkaline dry cell comprising: 
 a cathode and an anode, a separator placed between said cathode and said anode and an electrolyte solution that are housed inside an external can having a cylindrical shape with a bottom, and a resin sealing member and a supporting member for supporting said sealing member with the inner circumferential portion that are attached to an opening edge of the external can,    wherein the opening edge of the external can is sealed by tightening the resin sealing member with the external can and the supporting member,    wherein a sheet of metal plate that also serves as an anode terminal plate is used as the supporting member,    wherein the metal plate comprises a terminal face having a protruding shape placed in the center and a circumferential flange face formed in a manner surrounding the terminal face when viewed in a direction vertically penetrating the terminal face, and a flat portion is formed on the inner circumferential side of the flange face, the flange face flat portion and the terminal face being set so as not to be in parallel with each other.    
     
     
         6 . The alkaline dry cell according to  claim 5 , wherein the angle made by the terminal face of the metal plate and the flat portion of the flange face is set to not less than 4 degrees.  
     
     
         7 . The alkaline dry cell according to  claim 6 , wherein along all the outer circumferential portion of the metal plate, as a portion for sandwiching the resin sealing member together with the external can, a curved portion, which has an average curvature radius of not more than 1 mm in a cross-section obtained when the metal plate is cut in the thickness direction through the center thereof, is installed.  
     
     
         8 . An alkaline dry cell comprising: 
 a cathode and an anode, a separator placed between said cathode and said anode and an electrolyte solution that are housed inside an external can having a cylindrical shape with a bottom, and a resin sealing member and a supporting member for supporting said sealing member with the inner circumferential portion that are attached to an opening edge of the external can,    wherein the opening edge of the external can is sealed by tightening the resin sealing member with the external can and the supporting member,    wherein a sheet of metal plate that also serves as an anode terminal plate is used as the supporting member,    wherein the resin sealing member comprises a boss section holding an anode collector rod to be inserted to the center portion of the anode, an outer circumferential portion which is supported by the supporting member with the inner circumferential side so as to contact the inner circumferential face of the external can, and a connecting portion for connecting the boss section and the outer circumferential portion,    wherein an anti-explosion thin portion is installed on the foot portion on the boss section side in the connecting portion of the resin sealing member, and a stress absorbing portion, which absorbs one portion of the stress exerting on the connecting section so as not to allow the stress to concentrate on the anti-explosion thin portion when the resin sealing member is tightened to seal the opening edge of the external can, is placed on the foot portion on the outer circumferential portion side,    wherein said stress absorbing portion is formed in such a manner that its thickness becomes thinner discontinuously as compared with a portion positioned right inner circumferential side thereof, with a step difference placed between it and the portion positioned right inner circumferential side thereof.    
     
     
         9 . An alkaline dry cell comprising: 
 a cathode and an anode, a separator placed between said cathode and said anode and an electrolyte solution that are housed inside an external can having a cylindrical shape with a bottom, and a resin sealing member and a supporting member for supporting said sealing member with the inner circumferential portion that are attached to an opening edge of the external can,    wherein the opening edge of the external can is sealed by tightening the resin sealing member with the external can and the supporting member,    wherein a sheet of metal plate that also serves as an anode terminal plate is used as the supporting member, the resin sealing member comprises a boss section holding an anode collector rod to be inserted to the center portion of the anode, an outer circumferential portion which is supported by the supporting member with the inner circumferential side so as to contact the inner circumferential face of the external can, and a connecting portion for connecting the boss section and the outer circumferential portion, and    wherein an anti-explosion thin portion is installed on the foot portion on the boss section side in the connecting portion of the resin sealing member, said thin portion being formed in such a manner that its thickness becomes thinner discontinuously as compared with a portion positioned right outer circumferential side thereof in a manner so as to surround the thin portion, with a step difference being placed between it and the portion positioned outside thereof.    
     
     
         10 . An alkaline dry cell comprising: 
 a cathode and an anode, a separator placed between said cathode and said anode and an electrolyte solution that are housed inside an external can having a cylindrical shape with a bottom, and a resin sealing member and a supporting member for supporting said sealing member with the inner circumferential portion that are attached to an opening edge of the external can,    wherein the opening edge of the external can is sealed by tightening the resin sealing member with the external can and the supporting member,    wherein a sheet of metal plate that also serves as an anode terminal plate is used as the supporting member,    wherein the resin sealing member comprises a boss section holding an anode collector rod to be inserted to the center portion of the anode, an outer circumferential portion which is supported by the supporting member with the inner circumferential side so as to contact the inner circumferential face of the external can, and a connecting portion for connecting the boss section and the outer circumferential portion,    wherein an anti-explosion thin portion is installed on the foot portion on the boss section side in the connecting portion of the resin sealing member in a manner so as to have a thickness that becomes discontinuously thinner as compared with a first thickness portion located right outside this in a manner so as to surround the thin portion with a step difference from the first thickness portion, and a stress absorbing portion, which absorbs one portion of the stress exerting on the connecting section so as not to allow the stress to concentrate on the anti-explosion thin portion when the resin sealing member is tightened to seal the opening edge of the external can, is placed on the foot portion on the outer circumferential portion side in the connecting portion,    wherein said stress absorbing portion is formed in such a manner that its thickness becomes thinner discontinuously as compared with a second thickness portion positioned right inner circumferential side thereof, with a step difference being placed between it and the second thickness portion,    wherein said connecting portion has a portion reaching to the second thickness portion from the first thickness portion, which becomes continuously thicker from the first thickness portion toward the second thickness portion.    
     
     
         11 . The alkaline dry cell according to  claim 10 , wherein the thickness of the first thickness portion is set to ranging from 0.4 mm to 0.5 mm, and the second thickness portion is set to ranging from 2.5 times to 3.0 times greater than the first thickness portion.