Nakanishi Metal Works Co., Ltd.

Jtekt Corporation

Nobumasa Oka

Yoshihiro Ito

Masayoshi Nakamura

Michiyuki Kamiji

Mitsuru Saitoh

Ayumi Yamamori

A toothed pulley includes a cylindrical metallic core and a resin portion including teeth. The metallic core has, at one end thereof in the axial direction, an outward flange projecting outward in the radial direction. The outward flange has a radially outer peripheral surface that is a rotation prevention shape having a plurality of parts displaced inward in the radial direction from a cylindrical surface of the radially outer peripheral surface. The radially outer peripheral surface of the outward flange is covered by the resin portion.

Toothed pulley

The present invention is intended to provide an injection molding die that improves the strength of adhesion between an insert and a plastic in an insert molded article while suppressing fluctuations in the strength of adhesion. An injection molding die is used to manufacture an insert molded article by placing an insertwith a thermoset resin adhesive in the molding die and injecting a molten plastic material P from a gate G into a cavity C. The gate G is arranged at a position separated by 0.2 mm or more in an out-of-plane direction from a surface Aof the adhesive applied to the joining surface of the insert. During injection molding, the wall surface shear stress generated on the adhesive applied to the joining surface of the insertrelative to the plastic near the gate G becomes small. The adhesive is not swept away by the high-pressure molten plastic material P without having to bring the adhesive applied to the joining surface A of the insertinto the semi-cured state. Accordingly, it is possible to conduct injection molding without bringing the adhesive into the semi-cured state.

Manufacturing method of insert molded article

A molded articleis configured such that an insertis made of a steel plate and includes a cylindrical partA and an annular partB, a plasticis annular in shape so as to be joined to the annular partB, inner diameter Dof the plasticis larger than inner diameter Dof the annular partB so that no burrs at a gate mark E protrude to the inner diameter side of the molded article, the injection molding is conducted with a disc gate arranged on an inner peripheral surface F of the plasticat a position separated from a surface of the annular partB, and the gate mark E resides on the inner peripheral surface F of the plasticat a position separated from the surface of the annular partB.

Growing community of inventors

Osaka, Japan

Nobumasa Oka