Resin part and its manufacturing method

Patent metadata

Field	Value
Publication number	US-11801626-B2
Application number	US-202117358342-A
Country	US
Kind code	B2
Filing date	Jun 25, 2021
Priority date	Dec 26, 2018
Publication date	Oct 31, 2023
Grant date	Oct 31, 2023

Abstract

A resin part includes a plate-shaped molded main body that is constituted of an injection-molded product. Of plate surfaces of the molded main body, a surface on an opposite side to a surface requiring surface accuracy constitutes a pressure-application surface to which pressure is applied by a movable insert. A parting line is formed on the pressure-application surface by the movable insert to satisfy the following relationship: (t/4)≤x≤(3t/2), where x is a distance from an end edge part of the molded main body to the parting line and t is a thickness of the molded main body.

First claim

What is claimed is:

1. A resin part comprising a plate-shaped molded main body that is constituted of an injection-molded product, wherein
of plate surfaces of the molded main body, a surface on an opposite side to a surface requiring surface accuracy constitutes a pressure-application surface to which pressure is applied by a movable insert, and
a parting line is formed on the pressure-application surface by the movable insert to satisfy the following relationship:
( t/ 4)≤ x ≤(3 t/ 2),

where x is a distance from an end edge part of the molded main body to the parting line and t is a thickness of the molded main body.

2. The resin part as set forth in claim 1 , wherein in the molded main body, birefringence is constant regardless of the distance from a center of a gate portion or linearly increases with increase in the distance from the center of the gate portion.

3. A method of manufacturing a resin part, the resin part comprising a plate-shaped molded main body that is constituted of an injection-molded product,
the method comprising an injection molding step in which the molded main body is injection-molded by a molding apparatus,
the molding apparatus comprising a movable insert for applying pressure in a metal mold that forms a cavity corresponding to the molded main body,
wherein
in the injection molding step, an operation of moving the movable insert to apply pressure to a pressure-application surface of the molded main body is performed, and
the movable insert is provided so as to satisfy the following relationship:
( t/ 4)≤ x ≤(3 t/ 2),

where x is a distance from an end edge part of the molded main body to a parting line formed on the pressure-application surface of the molded main body by the movable insert, and t is a thickness of the molded main body.

4. The method as set forth in claim 3 , wherein in the injection molding step, a gate-cut operation of closing an injection gate is performed, immediately after completion of the injection of resin into the metal mold, in a state where a viscosity of the resin in the metal mold is low.

5. The method as set forth in claim 4 , wherein in the injection molding step, a pressure-application operation of causing the movable insert to operate is performed immediately after the gate-cut operation is performed.

6. The method as set forth in claim 5 , wherein the pressure-application operation is performed by moving the movable insert inside the metal mold at a set stroke.

Assignees

• Denso Corp

Inventors

• Yoshimura Yohei
• Kusano Takeshi
• Fukuda Kentaro
• Suzuki Mitsuhiro

Classifications

• B29C45/561 Primary

  Injection-compression moulding · CPC title

• B29C45/04

  using movable moulds {or mould halves}(B29C45/08 takes precedence) · CPC title

• B29C45/26

  Moulds · CPC title

• B29D11/00413

  made by moulding between two mould parts which are not in direct contact with one another, e.g. comprising a seal between or on the edges (B29D11/00019 - B29D11/00355, B29D11/00423, B29D11/00432 take precedence) · CPC title

• B29L2011/0016

  Lenses · CPC title