JPH0776028A - Method for manufacturing plug and mold for injection molding - Google Patents

Abstract

(57) [Summary] [Object] To provide a simple and therefore cost-effective manufacturing method of a plug and an injection molding mold for carrying out this method. A plug case for a conductor cross-sectional area of 0.75 mm ² or less is manufactured by injection molding around a conductor to be electrically connected. In this case, there is a difficulty in the injection molding technique due to the fact that the plug case has a thin wall and has a relatively long tubular wall. This disadvantage is that, according to the invention, the contact pin 3 is radially fixed during the injection molding process by radial clamping, in which case the insulating member 4 of the contact pin and the cases 1, 5, 6 are integrally formed. It is overcome by being injection molded. For this purpose, an injection molding die is used that receives a two-member mandrel 10 in which the core 7 clamps and fixes the contact pin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention implements a method of making a bipolar or multipolar plug provided at the end of an insulated electrical conductor having a conductor cross-sectional area of less than 0.75 mm ² and the method. For injection molding molds for

[0002]

2. Description of the Prior Art Bipolar or multipolar plugs are generally composed of a large number of assemblable individual parts, if their outer shape has a special structure. For example, a plug made up of a number of prefabricated and manually joined to each other is used to connect the two-wire leads of the ABS system of a motor vehicle. Among these individual members are the insulating holding members for contact pins, which are often formed in the shape of a dome (provided with a holding device for connecting the conductor and the contact pin), and a cylinder surrounding the holding members. -Shaped insulating case member, packing seal ring, and a fixable cap for the area for introducing an insulated electrical conductor or likewise a two- or three-wire conductor into the plug (see AMP commercial plug) ). When assembling such a plug, each conductor whose end is bare has a conductor cross-sectional area of 1
Contact pins smaller than or equal to mm ² are mounted. Furthermore, the conductor-side end of each contact pin and a part of the insulated conductor are surrounded by a dome-shaped insulating member common to all the conductors. Finally, the insulating member including the contact pin is surrounded by the insulating member and the insulating case which is tubularly projected from the contact pin in the axial direction. The special features of this insulating case are that its length is greater than 1.5 times its diameter, in particular greater than 2 times, and its wall thickness is less than 0.06 times its length, in particular 0.05. It is smaller than twice. Finally, the conductor or the lead-in area of the conductor is sealed by a packing ring and a cap fixable to the case. However, such assembly takes time,
Therefore, there is a cost.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is a method for manufacturing a two-pole or multi-pole plug provided at the end of an insulated electric conductor having a conductor cross section smaller than 0.75 mm ² . Each conductor with bare ends has a conductor cross-sectional area of 1 mm
^A contact pin less than or equal to ² is provided,
A part of the conductor insulated from the conductor-side end of each contact pin is surrounded by an insulating member, and the insulating member including the contact pin is surrounded by the insulating member and the insulating case protruding in a tubular direction from the contact pin in the axial direction. , The length of the case is greater than 1.5 times its diameter, and its wall thickness is less than 0.06 times its length, based on the method of manufacturing a bipolar or multipolar plug, Therefore, it is to provide a cost-effective manufacturing method.

A further object of the present invention is to provide an injection molding die for carrying out this method.

[0005]

According to the method for manufacturing a plug of the present invention, this problem is solved by axially fixing the contact pin in the injection molding mold by radial clamping after the contact pin is fixed to the conductor. Then, the insulating member and the case are integrally manufactured by injection molding in one working process.

In order to carry out this method, according to the invention, it comprises an outer member for shaping the outer contour of the plug and a core for shaping the inner contour of the plug, the core being A light conical through hole is provided for receiving a light cone shaped axially squeezable mandrel, the mandrel receiving the contact pin at the split mold end of the core at the injection mold side. An injection mold is used which consists of two lightly flared tongues with a notch for clamping.

[0007]

The manufacturing method according to the invention requires a very high injection pressure in order to manufacture a special plug case, and the contact pin is normally axially connected to the injection-mould by means of an axial form coupling. It is taken into account that an electrical conductor which can be fixed in the direction cannot be fixed in this case because its cross-sectional area is so small. Rather, for this purpose a radial force connection is used which is produced in the core region which receives the region which should not be injection molded around the contact pin. This radial force coupling results in an axial locking of the contact pins, so that these contact pins are subject to axial displacement under the influence of the high injection pressures required for thin and long case walls. There is no such thing. Plugs made in accordance with the present invention are identified by the fact that the split surface of the mandrel appears as a fine line on the end face of the insulating member, and sometimes on the crest of the dome-shaped insulating member.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a plug manufactured according to the present invention and an injection molding die for carrying out the manufacturing method according to the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the plug comprises a plug case 1 which is injection-molded at one end around cores 2 which are arranged in parallel at a distance from each other. ing. Each contact pin 3 is attached to the bare end of the core wire, and a dome-shaped insulating member 4 is injection-molded around the connection region between the contact pin and the conductor. The insulating member 4 is manufactured integrally with the case 1, and is provided with an introduction region 6 and a tubular case member 5 as other case members. The axial length L of the tubular case member 5 is slightly larger than twice the outer diameter D, while the wall thickness d is 0.0 of the length L.
It is slightly smaller than 5 times.

As shown in FIGS. 3 and 4, the core of the injection molding die is mainly composed of finger-shaped members 7 arranged on a cylindrical holding member 8. This finger-shaped member 7 is provided with a through hole 9 having in particular a section 91 for molding the dome-shaped insulating member 4 and a section 92 for guiding and receiving the mandrel 10 (FIG. 5). The section 92 is formed in a light conical shape.

As shown in FIGS. 5 and 6, the mandrel 10 has a mushroom-shaped cross section and is composed of two tongue-like members 11, 12 which abut one another in the region of the dividing surface 13. This mandrel has two blind holes 14, 1 for receiving and pinching the contact pin 3 in the area of the dividing surface on the end face side.
5 are provided. The outer contour of the mandrel is formed like a light cone like the section 92 of the core 7, so that when the mandrel 10 is pulled out, the tongue-like members 11 and 12 that spread out lightly for machining are inserted into the core 7. When the mandrels 10 are pushed in, they push each other, and the inserted contact pins 3 are clamped and fixed.

FIG. 7 shows an embodiment of the mandrel 10 in the case of manufacturing a plug for three core wires or three wire conductors. In this case, the dividing surface has a step in the central region, the bag hole for receiving the central contact pin is arranged in the lower tongue member, and the bag hole for receiving both outer contact pins is at the upper side. It is disposed on the tongue-shaped member.

[Brief description of drawings]

1 is a cross-sectional view of a plug manufactured according to the present invention.

2 is a side view of the plug shown in FIG. 1. FIG.

FIG. 3 is a cross-sectional view of a core used for an injection molding die.

FIG. 4 is a front view of the core shown in FIG.

5 is a cross-sectional view of a mandrel usable within the core shown in FIG.

FIG. 6 is a front view of a mandrel that receives two contact pins.

FIG. 7 is a front view of a mandrel that receives three contact pins.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plug case 2 Core wire 3 Contact pin 4 Insulating member 5 Case member 6 Introduction area 7 Finger-shaped member 8 Holding member 9 Through hole 10 Mandrel 11, 12 Tongue-shaped member 13 Dividing surface 14, 15 Bag hole L Axial length D Outer diameter d wall thickness

Claims (2)

[Claims] 1. A method for manufacturing a two-pole or multi-pole plug provided at an end of an insulated electric conductor having a conductor cross-sectional area smaller than 0.75 mm ^2, wherein each end has a bare conductor. A contact pin having a conductor cross-sectional area smaller than or equal to 1 mm ² is provided, a part of the conductor insulated from the conductor side end of each contact pin is surrounded by an insulating member, and the insulating member including the contact pin is the insulating member. And two poles which are surrounded by an insulating case which is tubularly protruded from the contact pin in the axial direction and whose length is larger than 1.5 times its diameter and whose wall thickness is smaller than 0.06 times its length. Alternatively, in the method for manufacturing a multipolar plug, the contact pin (3) is a conductor (2).
After being fixed to the mold, the mold is fixed by radial clamping in the injection molding die, and then the insulating member (4) and the case (1) are integrally manufactured by injection molding in one working process. A method for manufacturing a characteristic plug. 2. An injection molding mold comprising an outer member for imparting the outer contour shape of a plug and a core for imparting the inner contour shape of the plug, wherein the core (7) is a light cone. Is provided with a light conical through hole (9) for receiving a mandrel (10) which is shaped like a shaft and can be pushed in axially, the mandrel (10) for injection molding of the core at the dividing surface (13). Notch (1) for receiving and pinching the contact pin (3) at the mold side end.
4 and 15) with two light flared tongues (11, 1)
An injection mold for carrying out the method according to claim 1, characterized in that it is composed of 2).