Denso Corporation

Other

Mitsunori Adachi

Haruo Suzuki

Hiroshi Shohara

Yasuji Kasuya

Yasuo Tabuchi

Tetuo Ohno

Masahiro Kinoshita

Shigeo Murata

An annular groove portion is formed between portions corresponding to groove portions and thereafter the groove portions are formed while the annular groove is pressed. Consequently, since the stress produced due to a plastic deformation in forming the groove portions can be absorbed by the annular groove having a smaller rigidity than the groove portions, no undesirable plastic deformation of the groove portions occurs and hence the accuracy of the finished size of the multi-stage pulley can be improved. Furthermore, the capital investment in groove forming rollers can be reduced and the manufacturing cost of the multi-stage pulley can be reduced.

Multi-stage pulley and production method thereof

The manufacturing cost of a multi-stage pulley is reduced without coaxially arranging a plurality of groove forming sections. While a portion between groove sections is being pushed by a pushing roller , the groove sections are successively formed. While a portion of workpiece W pushed by a groove forming roller to form one groove section and a portion of workpiece W pushed by a groove forming roller to form the other groove section are being shifted from each other in the circumferential direction, one groove section ( ) and the other groove section ( ) are simultaneously formed. Due to the foregoing, when the groove sections are formed, it is possible to prevent the deformation of the groove section and the groove section which is adjacent to it. Accordingly, it is possible to enhance the yield of the multi-stage pulley without coaxially arranging a plurality of groove forming sections. Therefore, the cost of manufacturing the multi-stage pulley can be reduced.

Method of manufacturing multi-stage pulley

In forming a multi-grooved V pulley by roll forming, a preliminary forming method is disclosed for preventing the occurrence of a top roll accompanied by a crack along each annular ridge of the pulley. A preliminary form roller is pressed against an annular material to fabricate a preliminary form having, in a sectional view, a corrugation including linear flat root portions and ridges alternating with them on the bottom surface of a wide annular groove. Next, a finish form roller having a plurality of annular V-shaped protrusions is pressed against the linear flat root portions of the preliminary form to thereby finish roll the preliminary form. The forward end of each V-shaped protrusion is kept off from the slopes of the corrugation ridges, and therefore is not broken under a bending moment.

Method of manufacturing multi-grooved V pulley

Growing community of inventors

Toyohashi, Japan

Mitsunori Adachi