JPH09134743A - Terminal mounting method for ultra-thin cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the mounting of a terminal on a cable and enhance the reliability even though the terminal becomes large relatively in association with ultra-thin construction of the cable. SOLUTION: An ultra-thin cable 2' is structured so that an insulative covering is applied onto a conductor 2.1' consisting of ultra-thin element wires of metal which are stranded together, and a terminal 1 equipped with a cover pinching piece 1.1 and conductor pinching piece 1.2 together with a terminal piece for electric connection is attached to the end of the cable 2'. Before the mounting of the terminal 1, an electroconductive material 4 is applied to the inner surfaces of the pinching pieces 1.1 and 1.2 of the terminal or the surfaces of the mating insulative covering or conductor portions of the cable, and then the pinching pieces 1.1 and 1.2 set on the cable are fastened. As the conductive material, a conductive paste 4 consisting of a mixture of resin and metal powder is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of attaching a terminal to an ultrafine cable constituted by applying an insulating coating on a conductor formed by twisting extra fine wires.

[0002]

2. Description of the Related Art As a method of attaching a terminal to a cable, there is a method of using a crimp type terminal. FIG. 4 shows a general crimp type terminal. In FIG. 4, 1
Is a terminal, 1.1 is an insulating coating holding piece, 1.2 is a conductor holding piece, and 1.3 is a connection terminal piece for connection to a wiring board or the like.

FIG. 5 shows a connection state in which the terminal 1 as described above is attached to the cable 2. As is clear from this figure, the insulating cover sandwiching piece 1.1 and the conductor sandwiching piece 1.2 of the terminal 1 are respectively compressed, so that the former pushes the claw on the insulating cover portion of the cable 2 and tightens it. And also the latter is clamped onto the exposed conductor 2.1 so that it deforms.

FIG. 6 (a) shows a terminal insulating cover clamping piece 1.1.
Shows the situation where the cable 2 is crimped to the insulation coating portion, and FIG. 6B shows the situation where the conductor holding pieces 1 and 2 of the terminal are crimped to the cable conductor 2.1 portion.

[0005]

According to the above-mentioned conventional terminal mounting method, when the conductor holding piece 1.2 of the terminal as shown in FIG. 4 is swaged, the surface of the cable conductor 2.1. It turned out to be scratched. When the cable conductor 2.1 is an ultrafine metal wire, there is a possibility that the wire may be broken due to a scratch due to the caulking.

[0006] In recent years, due to the miniaturization of electronic equipment
Although cables (conductors) are being made thinner, it is difficult to change the shape of one terminal due to the relationship with the wiring board, etc. Therefore, as shown in FIG. Insufficient crimping of terminal 1 to 2 ',
It tended to be electrically and mechanically unstable.
In FIG. 7, (a) shows the crimping condition of the insulation coating sandwiching piece 1.1 against the insulation coating of the ultrafine cable 2 ', and (b) shows the conductor sandwiching piece for the conductor 2.1' of the ultrafine cable 2 '. The tightening condition of 1.2 is shown.

The inventors have tried a terminal mounting method as shown in FIG. 8 as a countermeasure for the above. This method uses the dummy wire 3 to fill the gap between the insulation coating of the ultrafine cable 2'and the insulation coating holding piece 1.1 as shown in (a), or (b).
As described above, the gap between the cable conductor 2.1 'and the conductor sandwiching piece 1.2 is to be filled. In other words, the dummy wire 3 is added so that the apparent outer diameter of the extra fine cable 2'is increased. By making the terminal bulky, the crimping of the relatively large terminal is sufficiently performed.

However, according to the above-mentioned trial, satisfactory results were not obtained, and the extra fine cable conductor 2.1 'was scratched. It was found that this scratch was caused by the dummy wire 3. In addition, workability at the time of mounting the terminals was also deteriorated, and eventually it was not possible to put it into practical use.

Therefore, the problem to be solved by the present invention is that even if the terminals become relatively large due to the extra fineness of the cable,
An object of the present invention is to provide a highly reliable terminal mounting method for an ultrafine cable by stabilizing the mounting of the terminal on the cable.

[0010]

A method of attaching a terminal of an ultrafine cable provided by the present invention is to connect to an end of an ultrafine cable formed by applying insulation coating on a conductor formed by twisting ultrafine metal wires. A method of attaching a terminal, which comprises an insulating-coated sandwiching piece and a conductor sandwiching piece together with a terminal piece, the inner surface of the insulating-coated sandwiching piece and the conductive sandwiching piece of the terminal, or the insulating coating portion and the conductor portion of a cable corresponding to them. Is coated with a conductive material, and then the insulating coating holding piece and the conductor holding piece of the terminal set on the cable are caulked. According to this method, the gap between the insulating coating of the ultrafine cable and the insulating coating sandwiching piece is filled with a conductive material, and the gap between the extrafine cable conductor and the conductor sandwiching piece is also filled with a conductive material. It becomes possible to sufficiently crimp the terminal while protecting the conductor of (1) with a conductive material.

Although various kinds of conductive materials can be considered, a preferable one is a conductive paste prepared by mixing a resin and a conductive metal powder.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a terminal used in a terminal mounting method for an ultrafine cable according to the present invention, and FIG. 2 shows a terminal mounting state.

However, the terminal 1 includes the terminal piece portion 1.3 for connecting to the wiring board and the insulating cover holding pieces 1.
1 and a conductor sandwiching piece 1.2. The insulating coating sandwiching piece 1.1 and the conductor sandwiching piece 1.2 are coated with a conductive paste 4 such as a commercially available silver paste serving as a conductive material.

Then, a conductive paste is applied also on the insulating coating portion of the ultrafine cable 2'and on the periphery of the conductor 2.1 ', and thereafter, as shown in FIG. 2, the insulating coating holding piece 1 of the terminal 1 is applied. 1 and the conductor holding piece 1.2 are crimped on the insulating coating of the extra-fine cable 2'and the conductor 2.1 via the conductive paste 4, so that the terminal 1 is machined via the conductive paste 4. It is designed to be attached electrically and electrically to the ultrafine cable.

FIG. 3 shows a main part of a terminal mounting portion for an ultrafine cable, wherein (a) is a crimping cross-section of an insulating coating holding 1.1, and (b) is a conductor holding piece 1.2. It is a crimping cross-section part of. As you can see from these figures,
A state in which the gap between the crimping and sandwiching pieces 1.1 and 1.2 and the ultrafine cable 2'is filled with the conductive paste 4 is formed.

[0016]

EXAMPLES As an evaluation of the stabilization of the connection between the terminal and the cable in the method of the present invention, the terminal crimping portion (the method of the present invention) in which the gap between the terminal and the cable is filled with a conductive paste and the conductive paste is not filled. Tensile tests were performed on the terminal crimping portions (conventional method). Table 1 shows the results.

[0017]

[Table 1]

As a result, according to the method of the present invention in which the gap between the terminal and the cable is filled with the conductive paste 4, the breaking load is increased by about 40% or more as compared with the conventional method (FIGS. 4 to 8). It was confirmed to do.

[0019]

According to the present invention as described above, even if the terminal becomes relatively large due to the extra fine cable, the attachment of the terminal to the cable is stabilized, and the extra fine cable is highly reliable. It is possible to achieve the intended purpose of providing a terminal mounting method in.

In addition, according to the method of the present invention, the conductive material is filled in the unavoidable gap between the crimped portion of the terminal and the insulating coating portion or conductor portion of the ultrafine cable. It is possible to stabilize the connection of the cable to the terminal piece and reduce the damage to the surface of the conductor that occurs when the terminal is crimped due to the thinning of the wire.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a terminal before attachment according to an embodiment of the present invention.

FIG. 2 is a perspective view showing how terminals are attached to an ultrafine cable according to an embodiment of the present invention.

3A and 3B are cross-sectional views showing a crimping condition of an insulating coating sandwiching piece, and FIG. 3B is a cross-sectional view showing a crimping condition of a conductor sandwiching piece according to an embodiment of the present invention.

FIG. 4 is a perspective view showing a terminal before attachment as a conventional example.

FIG. 5 is a perspective view showing how terminals are attached to a cable as a conventional example.

FIG. 6 is a cross-sectional view showing a crimping state of an insulating coating sandwiching piece, and (b) a cross-sectional view showing a crimping state of a conductor sandwiching piece in a conventional example.

FIG. 7 shows a problem when a relatively large terminal is attached to an ultrafine cable as a conventional example.
Is a cross-sectional view showing the crimping condition of the insulating coating holding piece,
(B) is sectional drawing which shows the crimping condition of a conductor clamping piece.

FIG. 8 shows a comparative example in which a relatively large terminal is attached to an ultrafine cable by using a dummy wire as a preceding example of the trial by the inventors of the present application. Sectional drawing which shows, (b) is sectional drawing which shows the crimping condition of a conductor clamping piece.

[Explanation of symbols]

 1 terminal 1.1 Insulating coating sandwiching piece 1.2 Conductor sandwiching piece 2'Extra fine cable 2.1 'Conductor 4 Conductive paste

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Komuro 5-1-1 Hidaka-cho, Hitachi-shi, Ibaraki Hitachi Cable Co., Ltd. Hidaka factory (72) Inventor Masafumi Kunii 880, Sunazawa-machi, Hitachi-shi, Ibaraki Within Hitachi Cable Assembly Co., Ltd.

Claims (2)

[Claims] 1. An end portion of an ultrafine cable formed by applying an insulating coating on a conductor formed by twisting ultrafine metal wires,
A method of mounting a terminal comprising an insulating coating sandwiching piece and a conductor sandwiching piece, the method comprising: attaching the insulating coating sandwiching piece and the conductor sandwiching piece to the inner surface of the terminal or the surface of the insulating coating portion and the conductor portion of the cable corresponding thereto. A terminal mounting method for an ultrafine cable, which comprises applying a conductive material, and then caulking an insulating coating holding piece and a conductor holding piece of a terminal set on a cable. 2. A method of mounting a terminal in an ultrafine conductor, wherein a conductive paste obtained by mixing a resin and a conductive metal powder is used as the conductive material.