Ring-shaped insert molded article

Patent metadata

Field	Value
Publication number	US-9962876-B2
Application number	US-201715412213-A
Country	US
Kind code	B2
Filing date	Jan 23, 2017
Priority date	Dec 5, 2013
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A molded article 1 is configured such that an insert 2 is made of a steel plate and includes a cylindrical part 2 A and an annular part 2 B, a plastic 4 is annular in shape so as to be joined to the annular part 2 B, inner diameter D 1 of the plastic 4 is larger than inner diameter D 2 of the annular part 2 B so that no burrs at a gate mark E protrude to the inner diameter side of the molded article 1 , the injection molding is conducted with a disc gate arranged on an inner peripheral surface F of the plastic 4 at a position separated from a surface of the annular part 2 B, and the gate mark E resides on the inner peripheral surface F of the plastic 4 at a position separated from the surface of the annular part 2 B.

First claim

The invention claimed is:

1. A method of producing a ring-shaped insert molded article,
wherein the article includes a ring-shaped insert made of a steel plate,
the insert has a cylindrical part and an annular part extended radially inward from one end edge of the cylindrical part, and
a plastic cylindrical in shape is joined via a thermoset adhesive to the cylindrical part of the insert, in a manner to extend from the cylindrical part to the annular part with forming a curve,
the method comprising the steps of;
applying a thermoset adhesive to the joining surface of the ring-shaped insert to the plastic, placing the ring-shaped insert to the plastic in an injection mold, clamping the injection mold, and filling the molten plastic from a disc gate separated from a surface of the annular part with an insert core into a cavity of the injection mold so as to conduct an injection molding,
cooling and hardening the molten plastic and removing the pre-gate cutting molded article and the insert core from the metal mold, and
pressurizing the molded article by a pusher to cut the gate while the pre-gate cutting molded article and the insert core removed from the metal mold are set on a jig,
wherein the gate mark resides on the inner peripheral surface of the plastic at a position separated from the surface of the annular part in the gate-cut state.

2. A method of producing a ring-shaped insert molded article,
wherein the article includes a ring-shaped insert made of a steel plate,
the insert has a cylindrical part and an annular part extended radially inward from one end edge of the cylindrical part, and
a plastic cylindrical in shape is joined via a thermoset adhesive to the cylindrical part of the insert, in a manner to extend from the cylindrical part to the annular part with forming a curve,
the method comprising the steps of;
applying a thermoset adhesive to the joining surface of the ring-shaped insert to the plastic, placing the ring-shaped insert to the plastic in an injection mold, clamping the injection mold, and filling the molten plastic from a disc gate separated from a surface of the annular part with a slide core into a cavity of the injection mold so as to conduct an injection molding,
cooling and hardening the molten plastic and removing the pre-gate cutting molded article from the metal mold, and
pressurizing the molded article by a pusher to cut the gate while the pre-gate cutting molded article removed from the metal mold are set on a jig,
wherein the gate mark resides on the inner peripheral surface of the plastic at a position separated from the surface of the annular part in the gate-cut state.

3. The method of producing a ring-shaped insert molded article according to claim 1 , wherein
the ring-shaped insert molded article is a radial magnetic encoder in which the ring-shaped insert is a support member and the plastic is a plastic magnet, and
the gate mark resides at a position separated 0.1 mm or more from the surface of the annular part.

4. The method of producing a ring-shaped insert molded article according to claim 2 , wherein
the ring-shaped insert molded article is a radial magnetic encoder in which the ring-shaped insert is a support member and the plastic is a plastic magnet, and
the gate mark resides at a position separated 0.1 mm or more from the surface of the annular part.

Assignees

• Nakanishi Metal Works Co

Inventors

• Ito Yoshihiro
• Oka Nobumasa

Classifications

• B29C45/14418 Primary

  Sealing means between mould and article · CPC title

• B29C45/38

  Cutting-off equipment for sprues or ingates · CPC title

• B29K2705/00

  Use of metals, their alloys or their compounds, for preformed parts, e.g. for inserts · CPC title

• B29C45/2708 Primary

  Gates (B29C45/2703 takes precedence) · CPC title

• B29K2105/251

  Particles, powder or granules (expandable particles B29K2105/046) · CPC title