Molding construction and a molding method for a resin-molded product

Abstract

A connector (20) is placed in a first die (50) so that an end of a wall (41) of the connector (20) closely contacts a recess (55) of the first die (50) to define a cutoff (58). The dies then are closed to define a filling space (60C) between a surface (62) of a second die (51) and an outer surface (46) of the wall (41). The outer surface (46) of the wall (41) is inclined moderately upward. Molten resin is directed into the filling space (60C) and presses the inclined outer surface (46) of the wall (41) so that an inner surface (47) of the bottom wall (41) is pressed against the recess (55) of the first die (50) and strongly held in close contact by a component of this pressing force. Thus, molten resin cannot intrude through the cutoff (58).

Description

BRIEF DESCRIPTION OF THE DRAWINGS.

FIG. 1 is a plan view of an ECU without a lid according to one embodiment of the invention.

FIG. 2 is a section of a connector embedded part of the ECU.

FIG. 3 is a section showing an arranged state of molding dies.

FIG. 4 is a section showing a state where the dies are closed with a connector placed as an insert.

FIG. 5 is a section showing a solidified state of molten resin in filling spaces.

FIG. 6 is a section of the ECU taken out from the molding dies.

FIG. 7 is a section of a prior art.

Claims

1. A molding construction for a resin-molded product (10), comprising: first and second molding dies (50, 51) openable and closable relative to each other, the first molding die (50) having a surface facing the second molding die (51) and a stepped recess (55) in the surface (54) of the first molding die (50), an insert (20) disposed in the first molding die (50) and held in close contact with a corner of the recess (55), the second molding die (51) having a surface (62) facing a side surface of the insert (20) while being spaced apart therefrom for defining a filling space (60C) upon closing the molding dies (50, 51), a resin flow path (X) into the filling space (60C) having an entry at a side where the recess (55) is located, and a cross-sectional area of the filling space (60C) being reduced gradually along the flow path (X) of the molten resin into the filling space (60C).

2. The molding construction of claim 1, wherein one side surface (47) and one end surface (45) of the insert (20) closely contact the corner of the recess (55).

3. The molding construction of claim 2, wherein the side surface of insert (20) substantially facing the filling space (60C) is inclined to narrow the width of the filling space (60C) gradually along a flowing path (X) of the molten resin.

4. The molding construction of claim 1, wherein the insert (20) is a resin-made primary molded product (20) placed in the first molding die (50) and a secondary molded product (11) is molded by flowing resin into the filling space (60C).

5. The molding construction of claim 4, wherein the primary molded product is a connector (20) having terminal fittings (26; 27) mounted therein, and the secondary molded product is a casing (11) in which the connector (20) is embedded.

6. A molding method for molding a resin-molded product (10), comprising the following steps: providing first and second molding dies (50, 51) openable and closable relative to each other, the first molding die (50) having a recess (55) in a surface (54) the first molding die (50) facing the second molding die (51);placing at least one insert (20) in the first molding die (50) so that the insert (20) is held in close contact with a corner of the recess (55);closing the first and second molding dies (50, 51) to define a filling space (60C) between a surface (62) of the second molding die (51) and a surface (46) of the insert (20);flowing molten resin along a flow path (X) into the filling space (60C) from a side where the recess (55) is located, thereby generating a pressing force component (f) by means of the flowing molten resin for presses the insert (20) against the recess (55) of the second molding die (51); andsolidifying the resin to form a molded product (11).

7. The molding method of claim 6, wherein the pressing force component (f) is generated by means of a cross-sectional area of the filling space (60C) being gradually reduced along the flowing path (X) of the molten resin into the filling space (60C).

8. The molding method of claim 6, wherein a resin-made primary molded product (20) as the insert (20) is placed in the first molding die (50) and a secondary molded product (11) is molded by flowing resin into the filling space (60C).

9. The molding method of claim 6, wherein the step of placing the insert (20) in the first molding die (50) comprises placing a side surface (47) and an end surface (45) of the insert (20) in close contact with the corner of the recess (55)

10. The molding method of claim 9, wherein the side surface of insert (20) facing the filling space (60C) is inclined for gradually narrowing the width of the filling space (60C) along the flow path (X) of the molten resin.