Louver Fin and Corrugation Cutter

Abstract

A louver fin ( 11 ) has a corrugated shape by alternately forming bent portions ( 15 ) and flat portions ( 17 ) in a strip thin sheet ( 13 ). In the louver fin ( 11 ), a plurality of louvers ( 19, 21 ) cut and bent out of the flat portions ( 17 ) along the longitudinal direction Y of the strip thin sheet ( 13 ) are arranged parallel to each other along the width direction X of the strip thin sheet ( 13 ). In the louver fin ( 11 ) the louvers ( 18, 19 ) are cut and bent at an approximately same angle with respect to the longitudinal direction Y of the strip thin sheet ( 13 ).

1 . A louver fin characterized by comprising:
 a plurality of flat portions which are made of a strip thin sheet, and in each of which a plurality of louvers are cut and bent along a longitudinal direction of the strip thin sheet, are arranged parallel to each other along a width direction of the strip thin sheet, and are formed so that bending angles of the louvers become approximately the same with respect to the longitudinal direction of the strip thin sheet; and   a bent portion serving as a boundary between the flat portions and being a portion for coupling the flat portions so that the plurality of flat portions form a corrugated shape.   
   
   
       2 . A corrugation cutter characterized by comprising: a pair of cutters in each of which a plurality of tooth portions are formed along a circumferential direction, and which are combined to mesh with each other; and
 characterized in that:   a corrugated fin with louvers is formed by forming alternately bent portions and flat portions in a strip thin sheet, which is supplied between the pair of cutters, at a predetermined pitch by using apex portions and bottom portions of the tooth portions facing each other, and by cutting and bending a plurality of louvers out of the flat portions of the strip thin sheet by using a plurality of cutting and bending edges provided on side surfaces of the tooth portions; and that   an edge angle of the cutting and bending edge provided on a side surface of each of the tooth portions changes along a longitudinal direction of the strip thin sheet so that the angle becomes smaller in a cutting start portion of one of the louvers and that the angle becomes larger in a cutting finish portion thereof.   
   
   
       3 . A corrugation cutter characterized by comprising:
 a first cutter in which a plurality of first tooth portions having triangular shapes are formed along a circumferential direction, in which a plurality of first cutting and bending edges for cutting and bending louvers in a strip thin sheet are provided on side surfaces in the circumferential direction of each of the first tooth portions, and in which an edge angle of each of the first cutting and bending edges gradually changes along longitudinal directions of the first cutting and bending edges so that the angle becomes smaller in a cutting start portion of one of the louvers, and that the angle becomes larger in a cutting finish portions thereof; and   a second cutter which is rotationally driven in synchronization with the first cutter so as to mesh with the first cutter; in which a plurality of second tooth portions are formed along a circumferential direction; in which the second tooth portions alternately form bent portions and flat portions machine the strip thin sheet into a corrugated shape in conjunction with the first tooth portions by alternately forming bent portions and flat portions of the strip thin sheet; in which a plurality of second cutting and bending edges for cutting and bending the louvers in the strip thin sheet in conjunction with the first tooth portions are provided on the side surfaces in the circumferential direction of the second tooth portions; and in which an edge angle of each of the second cutting and bending edges gradually changes along longitudinal directions of the cutting and bending edges so that the angle becomes smaller in the cutting start portion of one of the louvers, and that the angle becomes larger in the cutting finish portion thereof.   
   
   
       4 . A corrugation cutter characterized by comprising a pair of cutters in each of which a plurality of tooth portions are radially formed, and which are placed to face each other at a predetermined distance,
 characterized in that:   a corrugated fin with louvers is formed by forming alternately bent portions and flat portions in a strip thin sheet, which is supplied between the pair of cutters by using apex portions and bottom portions of the tooth portions facing each other, and by cutting and bending a plurality of louvers out of the flat portions of the strip thin sheet by using a plurality of cutting and bending edges provided on side surfaces of the tooth portions;   the cutting and bending edge provided on one side surface of each tooth portion is formed with an edge height which continuously increases from the apex-side edge portions toward the bottom-side edge portions, and which becomes smallest in an apex-side edge portion for machining a cutting start portion of one of the louvers, and becomes largest in a bottom-side edge portion for machining a cutting finish portion thereof, the cutting and bending edge including an inclined edge having an edge angle θ formed from the apex-side edge portions to the bottom-side edge portions; and that   the cutting and bending edge provided on the other side surface of each tooth portion is formed with an edge height which continuously increases from the apex-side edge portions toward the bottom-side edge portions, and which becomes smallest in a bottom-side edge portion for machining the cutting start portion of the louver, and becomes largest in apex-side edge portions for machining the cutting finish portion thereof, and the cutting and bending edge including an inclined edge having an edge angle θ formed from the bottom-side edge portions to the apex-side edge portions.   
   
   
       5 . A corrugation cutter characterized by comprising:
 a first cutter in which a plurality of first tooth portions are formed along a circumferential direction, in which a plurality of first cutting and bending edges for cutting and bending louvers in a strip thin sheet are provided on side surfaces in the circumferential direction of each of the first tooth portions, and in which an edge height of each of the first cutting and bending edges gradually changes along longitudinal directions of the first cutting and bending edges so that the height becomes smallest in a cutting start portion of one of the louvers, and become largest in a cutting finish portion thereof; and   a second cutter which is rotationally driven in synchronization with the first cutter so as to mesh with the first cutter; in which a plurality of second tooth portions are formed along a circumferential direction; in which the second tooth portions machine the strip thin sheet into a corrugated shape in conjunction with the first tooth portions by alternately forming bent portions and flat portions of the strip thin sheet; in which a plurality of second cutting and bending edges for cutting and bending the louvers in the strip thin sheet in conjunction with the first tooth portions are provided on the side surfaces in the circumferential direction of the second tooth portions; and in which an edge height of each of the second cutting and bending edges gradually changes along longitudinal directions of the second cutting and bending edge so that the height becomes smallest in the cutting start portion of the louver, and becomes largest in the cutting finish portion thereof.   
   
   
       6 . A corrugation cutter characterized by comprising:
 a first cutter in which a plurality of first tooth portions are formed along a circumferential direction, and in which a plurality of first cutting and bending edges for cutting and bending louvers in a strip thin sheet are provided on side surfaces in the circumferential direction of the first tooth portions, and in which an edge angle e of each of the first cutting and bending edges is constant along longitudinal directions thereof; and   a second cutter which is rotationally driven in synchronization with the first cutter so as to mesh with the first cutter; in which a plurality of second tooth portions are formed along a circumferential direction; in which the second tooth portions machine the strip thin sheet into a corrugated shape in conjunction with the first tooth portions, by alternately forming bent portions and flat portions of the strip thin sheet; in which a plurality of second cutting and bending edges for cutting and bending the louvers in the strip thin sheet in conjunction with the first tooth portions are provided on side surfaces of the second tooth portions in the circumferential direction; in which an edge angle θ of each of the second cutting and bending edges is constant along longitudinal directions thereof; and in which a clearance between the first cutting and bending edge and the second cutting and bending edge gradually changes relatively to be largest in a cutting start portion of one of the louvers and to be smallest in a cutting finish portion thereof.