Grid for a battery plate, method of producing the same, and battery using the same

Abstract

The invention provides a grid for a battery plate in which, when a metal sheet is formed into a grid-like shape, rupture due to torsion or stress concentration does not occur in a basal portion of a wire which is drawn out from a node of the grid, thereby preventing corrosion due to electrolyte from advancing so as not to cause a crack of corrosion in an early stage. The invention provides also a battery using the grid for a battery plate, a method of producing the grid for a battery plate, and a battery using it. In a grid for a battery plate in which large number of slits each configured by a cut elongating in a longitudinal direction are formed in a metal sheet in a zigzag pattern, the metal sheet is stretched in the width direction to develop the slits, and nodes are connected to one another to form a lattice-like shape, by four wires which are obliquely bent to be drawn out, at least one of the four wires connected to each of the nodes is bent in an oblique direction via a drawn-out portion which is drawn out from the node in a substantially longitudinal direction. A small slope having an inclination angle, or a curved face is interposed between slopes of peripheral side faces in a range from a valley to a ridge in a disk cutter which is placed in a disk cutter roll for a rotary expander. An inclined face which more approaches the axis as being nearer to a disk face on the side where a groove is formed, in a range from a ridge to a valley where the groove is formed, in a disk cutter which is placed in a disk cutter roll for a rotary expander. A small slope is interposed between a valley and at least a front slope of a peripheral side face of a ridge which is rearward adjacent to the valley, the small slope having an inclination angle which is between angles of the two faces. A grid for a battery plate is produced by using disk cutters in which a range from a valley to a groove is chamfered. The production method is configured so that, in each of ridges of endmost disk cutters which are disposed respectively on both the ends of a lower disk cutter roll, a peripheral side face configured by a reference circumferential face of a predetermined radius is formed, and, in each of valleys serving as endmost node forming valleys in the endmost disk cutters, an inward inclined face is formed, the inward inclined face being a tapered face which is recessed toward the center from the reference circumferential face, and which is inward inclined.

What is claimed is:  
     
         1 . A grid for a battery plate in which a large number of slits each configured by a out elongating in a longitudinal direction are formed in a metal sheet in a zigzag pattern, said metal sheet is stretched in a width direction to develop said slits, and nodes configured between slits that are adjacent in the longitudinal direction are connected to one another to form a lattice-like shape, by four wires which are configured between slits that are adjacent in the width direction, and which are obliquely bent to be drawn out, wherein 
 at least one of said four wires connected to each of said nodes is bent in a predetermined oblique direction via a drawn-out portion which is drawn out from said node in a substantially longitudinal direction.    
     
     
         2 . A method of producing a grid for a battery plate in which a metal sheet is passed between two rotating disk cutter rolls in each of which a plurality of disk cutters are placed on a same shaft with forming a gap therebetween, each of said disk cutters being configured by: alternately forming ridges which protrude in a ridge-like shape toward an outer peripheral side, and valleys composed of a circumferential face or a flat face along a circumferential direction on a peripheral side face of a disk; and forming grooves which are opened in an outer peripheral end and in every other valley alternately formed in both faces of said disk, in peripheral edges of both said faces of said disk, said disk cutter rolls being opposed to each other in a manner that said ridges of said disk cutters of one of said disk cutter rolls are placed in said gaps of said disk cutters of another disk cutter roll, whereby slits each configured by a cut elongating in a longitudinal direction are formed in said metal sheet, wherein 
 said valleys of said disk cutters of one of said disk cutter rolls which are placed respectively on both sides of said metal sheet are arranged with being shifted in phase from said valleys of said disk cutters of another disk cutter roll.    
     
     
         3 . A method of producing a grid for a battery plate in which a metal sheet is passed between two rotating disk cutter rolls in each of which a plurality of disk cutters are placed on a same shaft with forming a gap therebetween, each of said disk cutters being configured by: alternately forming ridges which protrude in a ridge-like shape toward an outer peripheral side, and valleys composed of a circumferential face or a flat face along a circumferential direction on a peripheral side face of a disk; and forming grooves which are opened in an outer peripheral end and in every other valley alternately formed in both faces of said disk, in peripheral edges of both said faces of said disk, said disk cutter rolls being opposed to each other in a manner that said ridges of said disk cutters of one of said disk cutter rolls are placed in said gaps of said disk cutters of another disk cutter roll, whereby slits each configured by a cut elongating in a longitudinal direction are formed in said metal sheet, wherein 
 a length in a circumferential direction of said valleys of said disk cutters of said disk cutter roll which is placed on one side of said metal sheet is larger than a length of said valleys of said disk cutters of said disk cutter roll which is placed on another side of said metal sheet.  
 
     
     
         4 . A method of producing a grid for a battery plate in which a metal sheet is passed between two rotating disk cutter rolls in each of which a plurality of disk cutters are placed on a same shaft with forming a gap therebetween, each of said disk cutters being configured by: alternately forming ridges which protrude in a ridge-like shape toward an outer peripheral side, and valleys composed of a circumferential face or a flat face along a circumferential direction on a peripheral side face of a disk; and forming grooves which are opened in an outer peripheral end and in every other valley alternately formed in both faces of said disk, in peripheral edges of both said faces of said disk, said disk cutter rolls being opposed to each other in a manner that said ridges of said disk cutters of one of said disk cutter rolls are placed in said gaps of said disk cutters of another disk cutter roll, whereby slits each configured by a cut elongating in a longitudinal direction are formed in said metal sheet, wherein 
 said grooves of said disk cutters of said disk cutter roll(s) which is placed on one side or both sides of said metal sheet are opened only in a part of a whole circumferential length of said valleys.    
     
     
         5 . A method of producing a grid for a battery plate in which a metal sheet is passed between two rotating disk cutter rolls in each of which a plurality of disk cutters are placed on a same shaft with forming a gap therebetween, each of said disk cutters being configured by: alternately forming ridges which protrude in a ridge-like shape toward an outer peripheral side, and valleys composed of a circumferential face or a flat face along a circumferential direction on a peripheral side face of a disk; and forming grooves which are opened in an outer peripheral end and in every other valley alternately formed in both faces of said disk, in peripheral edges of both said faces of said disk, said disk cutter rolls being opposed to each other in a manner that said ridges of said disk cutters of one of said disk cutter rolls are placed in said gaps of said disk cutters of another disk cutter roll, whereby slits each configured by a cut elongating in a longitudinal direction are formed in said metal sheet, wherein 
 two or more of settings are made, said settings including: setting in which said valleys of said disk cutters of one of said disk cutter rolls which are placed on both sides of said metal sheet are arranged with being shifted in phase from said valleys of said disk cutters of another disk cutter roll;    setting in which a length in a circumferential direction of said valleys of said disk cutters of said disk cutter roll which is placed on the one side of said metal sheet is larger than a length of said valleys of said disk cutters of said disk cutter roll which is placed on the other side of said metal sheet; and    setting in which said grooves of said disk cutters of said disk cutter roll(s) which is placed on the one side or both the sides of said metal sheet are opened only in a part of a whole circumferential length of said valleys.    
     
     
         6 . A method of producing a grid for a battery plate wherein slits in which a small bent portion is formed between a node and a fence-like portion are formed in a metal sheet by using disk cutters of a rotary expander in each of which a plurality of ridges an apex of which is shifted toward a front side in a rotational direction protrude with forming a gap therebetween toward an outer circumference from a disk-like circumferential face at equal angular intervals, a small slope is interposed between a valley constituting a peripheral side face between two of said ridges, and at least a front slope of a peripheral side face of a ridge which is rearward adjacent to said valley, thereby connecting peripheral side faces, said small slope having an inclination angle which is between angles of said two faces, and grooves which are formed at equal angular intervals in peripheral edges of both disk-like faces are formed in every other gap face and opened alternately in both said faces.  
     
     
         7 . A method of producing a grid for a battery plate wherein slits in which a portion between a node and a fence-like portion is curved are formed in a metal sheet by using disk cutters of a rotary expander in each of which a plurality of ridges an apex of which is shifted toward a front side in a rotational direction protrude with forming a gap therebetween toward an outer circumference from a disk-like circumferential face at equal angular intervals, a curved face is interposed between a valley constituting a peripheral side face between two of said ridges, and at least a front slope of a peripheral side face of a ridge which is rearward adjacent to said valley, thereby connecting peripheral side faces, said curved face having a contact face of an inclination angle which is between angles of said two faces, and grooves which are formed at equal angular intervals in peripheral edges of both disk-like faces are formed in every other gap face and opened alternately in both said faces.  
     
     
         8 . A method of producing a grid for a battery plate wherein slits in which a node is inclined are formed in a metal sheet by using disk cutters of a rotary expander in each of which a plurality of ridges an apex of which is shifted toward a front side in a rotational direction protrude with forming a gap therebetween toward an outer circumference from a disk-like circumferential face at equal angular intervals, a valley constituting a peripheral side face between two of said ridges is formed into a face which is more inclined toward a center as being more forward than a contact face contacting with a circumferential face in which all contacting faces contacting with said valley have a same angular position at a center of a rotation shaft, and grooves which are formed at equal angular intervals in peripheral edges of both disk-like faces are formed in every other gap face and opened alternately in both said faces.  
     
     
         9 . A method of producing a grid for a battery plate in which a plate is produced by a rotary expander for forming slits in a metal sheet by using disk cutters in each of which a plurality of ridges an apex of which is shifted toward a front side in a rotational direction protrude with forming a gap therebetween toward an outer circumference from a disk-like circumferential face at equal angular intervals, and grooves which are formed at equal angular intervals in peripheral edges of both disk-like faces are formed in every other valley constituting a peripheral side face between said ridges, and opened alternately in both said faces, wherein 
 each of said valleys of said disk cutter is formed into a face which is more inclined toward a center as being more forward than a contact face contacting with a circumferential face in which all contacting faces contacting with said valley have a same angular position at a center of a rotation shaft of said disk cutter.    
     
     
         10 . A method of producing a grid for a battery plate according to  claim 8  or  9 , wherein said valley is formed into a face which is more inclined by 1° or more toward the center as being more forward than said contact face contacting with said circumferential face in which all contacting faces contacting with said valley have a same angular position at the center of said rotation shaft of said disk cutter.  
     
     
         11 . A method of producing a grid for a battery plate according to any one of  claims 8  to  10 , wherein only a face of said valley excluding a front end portion is formed into a face which is more inclined toward the center as being more forward than said contact face contacting with said circumferential face in which all contacting faces contacting with said valley have a same angular position at the center of said rotation shaft of said disk cutter.  
     
     
         12 . A method of producing a grid for a battery plate according to any one of  claims 8  to  11 , wherein the circumferential face serving as a reference of inclination of said valley is a flat face connecting together cross lines between said circumferential face and said slopes of said ridges on both the sides.  
     
     
         13 . A method of producing a grid for a battery plate in which a rotary expander is used for forming a large number of zigzag slits in a metal sheet by passing said metal sheet between two or more opposed disk cutter rolls, each of said disk cutter rolls being configured by placing a plurality of disk cutters on a same shaft with forming a gap therebetween, each of said disk cutters being configured by: alternately forming ridges in which a peripheral side face protrudes in a ridge-like shape toward an outer periphery from a reference circumferential face of a predetermined radius, and valleys in which a peripheral side face composed of a face substantially extending along the said circumferential face is formed, in a whole periphery of a peripheral edge of a disk, said reference circumferential face being centered at an axis of said disk; and, for each of said valleys, forming a groove which is opened in a peripheral side face of said valley, in a peripheral edge portion of one of disk faces in which valleys that are adjacent to each other via a ridge are formed in an oppositely reverse manner, wherein 
 in each of said disk cutters, an inclined face is formed in peripheral side faces which extend from apexes of ridges formed on both sides of each of said valleys to said valley, said inclined face more approaching the axis as being nearer to said disk face in which said groove of said valley is formed.    
     
     
         14 . A grid for a battery plate which is produced by the production method of  claim 13 .  
     
     
         15 . A method of producing a grid for a battery plate in which a plurality of parallel slits are cut in a metal sheet into a zigzag pattern along an advancing direction of the metal sheet, wires which are formed by slits that are adjacent in a width direction of said metal sheet are elastically deformed in a ridge-like shape in both front and back directions from a face of said metal sheet, flat regions which are formed by non-slit portions are formed to become nodes of said wires, and said metal sheet is developed in the width direction, thereby forming meshes, wherein said slits which are cut into a zigzag pattern are formed by passing said metal sheet through a roll pair in which rolls are opposed to each other, each of said rolls is configured by stacking disk cutters each having ridges and valleys, said ridges protruding at regular intervals from a circumference of said disk cutter, and, in said disk cutter, grooves are disposed in a thickness direction in each of said valleys between said ridges and alternately in both disk faces corresponding to said nodes, and chamfered portions are disposed in an outer peripheral portion of a peripheral side face of said disk cutter, said outer peripheral portion excluding at least said ridges, said chamfered portions being lowered as being respectively nearer to said faces in which said grooves are disposed.  
     
     
         16 . A method of producing a grid for a battery plate according to  claim 15 , wherein said chamfered portions between said peripheral side face of said disk cutter and said disk faces of said disk cutter in which said grooves are formed are planer or curved chamfered portions.  
     
     
         17 . A battery comprising a grid for a battery plate which is produced by the method of  claim 15  or  16 .  
     
     
         18 . A method of producing a grid for a battery plate in which a rotary expander is used for forming a large number of zigzag slits in a metal sheet by passing said metal sheet between two or more opposed disk cutter rolls, each of said disk cutter rolls being configured by placing a plurality of disk cutters on a same shaft with forming a gap therebetween, each of said disk cutters being configured by: alternately forming ridges in which a peripheral side face protrudes in a ridge-like shape toward an outer periphery from a reference circumferential face of a predetermined radius, and valleys in which a peripheral side face composed of a face substantially extending along the reference circumferential face is formed, in a whole periphery of a peripheral edge of a disk, the reference circumferential face being centered at a rotation axis of said disk; and, for each of said valleys, forming a groove which is opened in a peripheral side face of said valley, in a peripheral edge portion of one of disk faces in which valleys that are adjacent to each other via a ridge are formed in an oppositely reverse manner, wherein 
 among said disk cutter rolls, a disk cutter roll which is opposed to a disk cutter roll having a disk cutter that is disposed outermost is provided with a disk-like endmost disk cutter that is placed more outward than said outermost disk cutter, and a peripheral side face which is recessed toward a center with respect to said reference circumferential face is formed in a valley (hereinafter, referred to as “endmost node forming valley”) which corresponds to a valley in a disk cutter of another disk cutter roll that is opposed via said metal sheet, among valleys of said endmost disk cutter (in said endmost disk cutter, peripheral edge portions respectively corresponding to valleys of another disk cutter of a same disk cutter roll are referred to as “valleys”), a groove being formed in a disk face in said groove of said disk cutter of said other disk cutter roll, said disk face directed to said endmost disk cutter.    
     
     
         19 . A method of producing a grid for a battery plate according to  claim 18 , wherein an inclined face is formed in said peripheral side face of said endmost node forming valley, said inclined face being nearer to the center as being more inward.  
     
     
         20 . A grid for a battery plate which is produced by the production method of  claim 18  or  19 .