Method of manufacturing cvt belt

Abstract

In order to restrain the length of an endless metal ring from dispersing, a method of manufacturing a CVT belt has a first-stage stretching step of extending a circumferential length of an endless metal belt by widening distances among rollers. The method includes a measuring step of measuring a spring-back amount of the endless metal belt in the first-stage stretching step. The method includes a calculating step of calculating a predicted spring-back amount that is predicted from the measured spring-back amount. The method also includes a second-stage stretching step of stretching the endless metal belt to process the endless metal belt into a predetermined circumferential length by further widening the distances among the rollers based on the predicted spring-back amount.

1 . A method of manufacturing a CVT belt in which an endless metal belt is retained from inside by at least two rollers and is processed to have a predetermined circumferential length by widening a gap between the rollers, the method comprising:
 a first-stage stretching step of stretching the endless metal belt to extend a circumferential length of the endless metal belt by widening a distance between the rollers;   a spring-back measuring step of measuring a spring-back amount of the endless metal belt in the first-stage stretching step;   a calculating step of calculating a predicted spring-back amount from the measured spring-back amount, the predicted spring-back amount being predicted to result in a second-stage stretching step; and   the second-stage stretching step of stretching the endless metal belt and processing the endless metal belt to have the predetermined circumferential length by further widening the distance between the rollers based on the predicted spring-back amount.   
     
     
         2 . The method of manufacturing the CVT belt according to  claim 1 , further comprising:
 a material length measuring step of measuring a material circumferential length before stretching the endless metal belt prior to the first-stage stretching step,   wherein the endless metal belt is stretched, in the first-stage stretching step, to be processed such that a first-stage stretch length of a stretching process to which the endless metal belt is subjected becomes approximately 90 percent of a target process circumferential length that is obtained by subtracting the material circumferential length from a target circumferential length of the endless metal belt.   
     
     
         3 . The method of manufacturing the CVT belt according to  claim 1 , wherein
 the rollers include at least a first roller and a second roller,   the second roller includes a moving mechanism designed to move the second roller toward and away from the first roller, and an urging mechanism designed to urge the second roller in a moving direction of the second roller, and   the spring-back amount of the endless metal belt is measured with a certain load applied to the second roller by the urging mechanism, in the spring-back measuring step.   
     
     
         4 . The method of manufacturing the CVT belt according to  claim 2 , wherein
 the rollers include at least a first roller and a second roller,   the second roller includes a moving mechanism designed to move the second roller toward and away from the first roller, and an urging mechanism designed to urge the second roller in a moving direction of the second roller, and   the spring-back amount of the endless metal belt is measured with a certain load applied to the second roller by the urging mechanism, in the spring-back measuring step.