GB2206457A

GB2206457A - Conductive adhesive terminal connection for noise-suppressing high-voltage resistive wire

Info

Publication number: GB2206457A
Application number: GB08810388A
Authority: GB
Inventors: Shigehiko Mochizuki; Mitsuyasu Tanaka
Original assignee: Yazaki Corp
Current assignee: Yazaki Corp
Priority date: 1987-05-08
Filing date: 1988-05-03
Publication date: 1989-01-05
Anticipated expiration: 2008-05-03
Also published as: JPS63178068U; GB2206457B; JPH0212680Y2; DE3815555A1; GB8810388D0

Description

2r206457 TERMINAL CONNECTOR FOR NOISE-SUPPRESSING HIGH-VOLTAGE RESISTIVE

WIRE -)o It.

2^5 1 The present invention relates to a terminal connector for a noisesuppressing high-voltage resistive wire, the connector comprising a metal fitting adapted to be fitted with a terminal port of, for eXample, an ignition coil, distributor or sparkplug of an automobile.

A conventional terminal connection portion of a wire of this type is shown in Figure 1 of the accompanying drawings; this side view shows a core conductor b of a noise-supplessing high-voltage resistive wire a folded back at its terminal portion along the outside of an insulating layer c and caulked by a solderless contact portion e (eld, e 2) of a terminal metal fitting jj. In order to improve the force of retention between the terminal metal fitting and the wire, it has been the practice to increase the length of the metal fitting so as to provide an additional solderless contact portion e 3 However, if the length of the metal fitting is increased, the terminal portion of the wire becomes stiff and bulky. This is a disadvantage in a crowded engine compartment, since the space required for each wire must be increased in order to avoid problems such as short-circuiting. Moreover, for an increased number of solderless contact portions, the insulating coating of the wires tends to soften more readily under the increased heat transferred thereto, thereby reducing the retaining force and the current-carrying capacity of the fitting. Alsd, the me tal fitting can more easily be accidentally pulled off during maintenance procedures.

In accordance with the present invention, in the terminal connection portion of a noise-suppressing high-voltage resistive wire, including a terminal metal fitting adapted to be fitted with a terminal post of a sparkplug, ignition coil or the like, solderless contact portions of the terminal metal fitting are caulked with a heat-resistant elec tricallyconductive adhesive agent disposed among the solderless contact portions, the insulating.coating of the wire, and a core conductor portion of the wire which is folded back along the insulatinc coating.

While Fig. 1 is a side view of a conventional terminal connection portion of a noise-suppressing high-voltage resistive wire, the invention will now be described by way of example only with reference to the remaining accompanying drawings, in which:

Fig. 2 is a side view of a terminal connection portion of a noisesuppressing high-voltage resistive wire which is a preferred embodiment of the present invention; Fig. 3 is the side view of Fig. 2, in which part of the terminal connector is cut-away and shown in section; Fig. 4 is a cross-section along the line IV-IV in Fig. 3; Fig. 5 is a side view of another preferred embodiment of the present invention; Fig. 6 is the side view of Fig. 5, in which part of the terminal connector is cut-away and shown in section; and rig. 7 is a cross-section along the line VII-VII in Fig. 6.

Figs. 2, 3 and 4 show a noise;-suppressing high-voltage resistive wire 6 and a terminal metal fitting 1 adapted to be fitted with a terminal post of a sparkplug, ignition coil or the like, solderless contact portions Sa and 5b of the terminal metal fitting 1 are caulked with a heat-resistant electrically conductive adhesive agent 9 disposed among the solderless contact portions 5a and 5b, the insulating coating 7 of the wire 6 and a core conductor portion 8 of the wire, which is folded back along the insulating coating 7._ The terminal metal fitting 1 in this example is connected to a sparkplug. The metal fitting 1 includes a receiving sleeve portion formed at the front portion of a stainless steel substrate 2 and having a shape suitable for receiving a terminal post, a reinforcing band 4 mounted on the receiving sleeve portion so as to cover the latter, and two pairs of solderless contact portions Sa and 5b formed at the rear portion of the stainless steel substrate 2 rising continuously from the stainless steel substrate 2 at its opposite sides.

A heat-resistant electrically conductive adhesive agent 9 is applied to the respective inner surfaces of the solderless contact portions Sa and 5b, and the solderless contact portions Sa and 5b are caulked under the condition that the core conductor 8, which Is bent back along the insulating coating 7 of the wire, is made to face the substrate 2. The adhesive agent 9 is hardened such as by heating or the like.

For the heat-resistant electrically conductive adhesive agent 9 it is preferred to use a mixture of thermosetting resin such a phenol resin, resorcin resin. polyurethane resin, epoxy resin, or the like, mixed together with an electrically conductive material such as carbon black, graphite particles, carbon fiber, metal particles. metal fiber. or the like. Preferably, in order to provide improved flexibility, the electrically conductive material may contain one or more of carbon black, graphite particles. and carbon fiber. The electrically conductive material is added in an amount of 5 to 200 parts by weight, preferably, 10 to 100 parts by weight, relative to 100 parts by weight of the thermosetting resin. Epoxy resin is particularly preferred in that it provides a strong adhesive effect between the terminal metal fitting 1 and the insulating coating 7 of the wire as well as between the terminal metal fitting 1 and the core conductor.

With the conductive adhesive agent 9 provided between the solderless contact portions Sa and 5b of the terminal metal fitting 1 and the wire 6. the terminal metal fitting 1, the core conductor 8. and the wire 6 (the insulating coating 7) are made to strongly adhere to one another. Accordingly, the force of adherence between the terminal metal fitting and the wire is significantly improved.

Further, since the conductive adhesive agent 9 contacts the core conductor 8, the contact area between the core conductor 8 and the terminal metal fitting 1 Is increased, and hence the current handling capacity is improved.

In the embodiment of Figs. 2, 3 and 4,, the terminal metal fitting 1 is provided with two pairs of solderless contact portions Sa and 5b and is used f or connection to a sparkplug. A second preferred embodiment with be described with reference to Figs. 54. 6 and 7 in which a stainless steel terminal metal fitting 10 is used for making connection to a distributor.

With ref erence to Figs. 5 j 6 and 7. the terminal metal fitting 10 is constituted by a receiving sleeve portion 11. an inwardly tapered gathered portion 12 formed at the forward end of the receiving sleeve portion 11, and a pair of solderless contact portions 13. A heat- resistant conductive adhesive agent 9 is applied onto the respective inner surfaces of the solderless contact portions 13 and a terminal portion of a noi se-suppres sing high-voltage resistive wire 6 is caulked by the solderless contact portions 13 in the same manner as described above with respect to the first embodiment.

Due to the presence of the conductive adhesive agent 9, the retaining force and the current carrying capacity between the terminal metal fitting and the wire is increased.

Accordingly. the number of solderless contact portions 13 can be reduced in number to thereby permit the overall length of the terminal metal fitting to be made shorter, making the terminal metal fitting more compact. Moreover, due to the shortened length of the terminal metal fitting, less heat will be transferred to the insulation of the wire. and hence there will be less of a temperature rise in the insulation. Thus, there will be less softening of the insulation, making the connection between the wire -and the terminal metal fitting more secure.

Claims

CIAIMS

1. A noise-suppressing high-voltage wire bearing a terminal connector adapted to be fitted with a terminal post of a spark plug, ignition coil or the like, the terminal connector having a contact portion contacting a core conductor of the wire folded back along an insulating coating oil the wire, in which the contact portion is caulked with a heat-resistant electricallyconductive.adhesive agent disposed among the contact portion, the insulating coating and the core conductor.

2. A wire according to claim 1, wherein the adhesive agent comprises a mixture of a thermosetting resin and an electrically-conductive material.

3. A wire according to claim 2, wherein the thermosetting resin is selected from phenol resins, resorcin resins, polyurethane resins and epo.xy resins.

4. A wire according to claim 2, wherein the thermosetting resin comprises epoxy resin.

5. A wire according to any of claims 2 to 4, wherein the electricallv-conductive material is selected from carbon black, graphite particles, carbon fibre, metal particles and metal fibre.

6. A wire according to claim 5, wherein the electrically- conductive material is selected from carbon black, graphite particles and carbon fibre.

7. A wire according to any of claims 2 to 6,j which comprises 5 to 200 parts-per weight of' the electricallyconductive mattrial per 100 parts per weight of the thermosetting resin. 30

8. A wire according to claim 7, which comprises 10 to 100 parts per weight of the electrically-conductive material per 100 parts per weight of the thermosetting resin.

9. A wire according to claim 1, substantially as illustrated in any of Figures 2 to 7 of the accompanying drawings.

2'5 Published 1988 at The Patent Mce, State House. 66.71 High Holborn. London WC1R 4TP. Further copies may be obtained from The Patent Ofnce. Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1187.