Two-color molding method and two-color molded article

Patent metadata

Field	Value
Publication number	US-9895859-B2
Application number	US-201514688295-A
Country	US
Kind code	B2
Filing date	Apr 16, 2015
Priority date	Apr 23, 2014
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

Provided are a two-color molding method, and a two-color molded article capable of suppressing deterioration of the appearance quality which is caused by resin shrinkage or resin deformation in the two-color molding. The two-color molding method includes: molding a first resin portion by a common die and a primary die; and molding a second resin portion integrally with the first resin portion by the common die and a secondary die. An abutting portion is molded on an edge of the first resin portion to protrude toward the secondary die when the first resin portion is molded, and a distal end surface of the abutting portion is maintained to be abutted on a cavity surface or a parting surface of the secondary die when the second resin portion is molded. The deformation of the abutting portion or the first resin portion is suppressed to suitably mold the second resin portion.

First claim

What is claimed is:

1. A two-color molding method comprising:
molding a first resin portion by a common die and a primary die;
molding a second resin portion integrally with the first resin portion by the common die and a secondary die provided with a slider for molding an undercut portion; and
molding the undercut portion present in a part of the second resin portion using the slider,
wherein an abutting portion is molded on an edge of the first resin portion to protrude toward the secondary die when the first resin portion is molded, and a distal end surface of the abutting portion is maintained to be abutted on a cavity surface or a parting surface of the secondary die and the abutting portion is maintained to be clamped between the common die and the secondary die when the second resin portion is molded, and
the first resin portion is constituted by a light transmitting resin portion, the second resin portion is constituted by a non-light transmitting resin portion, the abutting portion is placed along a peripheral edge of the first resin portion, and the second resin portion is molded to be stacked on the peripheral edge of the first resin portion in a region inside the abutting portion.

2. The two-color molding method of claim 1 , wherein the abutting portion is formed as a side wall erected continuously or intermittently along the edge of the first resin portion, or as a plurality of separate projections.

3. The two-color molding method of claim 1 , wherein the second resin portion is configured as a mounting unit for attaching a front cover including the first resin portion and the second resin portion to a lamp body of a vehicular lamp.

4. The two-color molding method of claim 1 , wherein a thickness of the abutting portion is set to be larger than a thickness of an inner region of the peripheral edge.

5. The two-color molding method of claim 4 , wherein the thickness of the abutting portion is set to be equal to an inner diameter of a cavity configured by the common die and the secondary die for molding the second resin portion.

Assignees

• Koito Mfg Co Ltd

Inventors

• Ito Hiroya

Classifications

• B29K2995/0025

  Opaque · CPC title

• B29C2045/1682

  preventing defects · CPC title

• B29C45/16 Primary

  Making multilayered or multicoloured articles {(B29C45/0062 takes precedence; feeding colouring materials into the injection unit B29C45/1816)} · CPC title

• B29C45/0025

  Preventing defects on the moulded article, e.g. weld lines, shrinkage marks (preventing defects on the preformed parts or layers B29C45/14836) · CPC title

• F21S41/20

  characterised by refractors, transparent cover plates, light guides or filters · CPC title