JPH09161933A - Lead wire connecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the strands constituting a core wire from being disturbed by applying soldering to the weld section of the core wire in advance when a lead wire is welded to a terminal member by electrical resistance heating. SOLUTION: When the coil lead wire of an electromagnetic sensor is connected to a signal guide lead wire 13 by electrical resistance heating via a relay terminal, part of an insulating cover 13b is removed so that only the tip of the core wire 13a of the lead wire 13 is exposed. Soldering is applied only to a tip exposed section, and the core wire 13a is exposed by the specified size required for welding. The strand of the core wire 13a is prevented from being disturbed, and the welding work can be properly performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead wire connecting method for welding a core wire to a terminal by electric resistance heating.

[0002]

2. Description of the Related Art A conductor of a coil such as an electromagnetic sensor is connected to a lead wire for signal derivation through a relay terminal. Spot welding by electric resistance heating is used as a method of connecting the lead wire to the relay terminal.

[0003]

The spot welding is
Since the core wire of the lead wire is pressed between the electrodes together with the terminal, the wires forming the core wire may be disturbed.
If the strands are disturbed, they will stick out of the weld and come into contact with other parts, the number of strands actually connected to the terminal will decrease, and the connection strength will be insufficient, or the conductive path cross-sectional area will be insufficient. There is an inconvenience.

The present invention has been devised to eliminate such inconvenience, and its main object is to provide a lead wire connecting method capable of preventing the strands of a welded portion from being disturbed. .

[0005]

In order to achieve such an object, in the present invention, the soldered portion of the core wire is preliminarily soldered, and then the core wire is attached to the terminal by electric resistance heating. We decided to weld. In particular, the insulating coating of a specified dimension required for welding is removed after soldering is performed in a state where the insulating coating of only the tip portion of the core wire is removed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an electromagnetic sensor to which the present invention is applied. The electromagnetic sensor 1 is formed by integrally molding a housing part 3 covering the periphery of a sensitive element part 2 described below, a mounting stay part 4 for the vehicle body, and a cable pulling part 5 with a synthetic resin material. In addition, in the mounting stay portion 4,
A metal collar 6 for receiving the bolt tightening force is inserted.

As shown in FIG. 2, the sensitive element portion 2 includes a bobbin 7 injection-molded from a synthetic resin material, and a pair of terminal members 8 press-fitted and fixed to one axial end surface of the bobbin 7.
A coil 9 composed of a conductive wire wound around the bobbin 7 after each end of the bobbin 7 is connected to the respective ends of the bobbin 7, a pole piece 10 mounted in a central hole of the bobbin 7, a permanent magnet 11, and a yoke 12
And a lead wire 13 connected to a vehicle control circuit via a connector (not shown).

As shown in FIG. 3, the end of the lead wire 14 of the coil 9 is insulated from the surface of the lead wire by passing an electric current while crimping the electrode against the lead holding portion 15 of the terminal member 8 in which this end is entangled. The layers are melted by heat, the copper layer of the conductive wire 14 and the tin layer plated on the terminal member 8 are melted, and fused to the conductive wire holding portion 15 by fusing.

In the lead wire 13, a copper layer of the core wire of the lead wire 13 and a tin layer plated on the terminal member 8 are formed by applying an electric current to the lead wire holding portion 16 of the terminal member 8 while crimping the electrode. And are melted, and the solder previously applied to the end of the core wire of the lead wire 13 is melted into the entire joint portion and is firmly joined to the lead wire holding portion 16. High-temperature solder is used as the solder.

The lead wires 13 are prevented from slipping by lightly press-fitting the lead wires 13 into the holding grooves 17 formed in the one end surface of the bobbin 7. A cable retainer 18 is previously molded on the coating of the lead wire 13.

The sensitive element portion 2 assembled in this way
And the metal collar 6 in the lower mold 19 and the upper mold 2
0 is closed, and molten resin is injected from the gate 21 into the cavity formed between the outer surface of the sensitive element portion 2 and the inner surface of the lower mold 19, thereby removing the sensitive element portion 2 and the collar 6 as shown in FIG. The housing portion 3 and the stay portion 4 are integrally molded in the inserted state.

As described above, if the insulating coating is simply removed when the lead wire 13 is welded to the terminal member 8, the strands forming the core wire of the lead wire 13 when pressed by the electrodes. May be disturbed. Therefore, in the present invention, as shown in FIG. 5A, first, a part of the insulating coating 13b is removed so that only the tip of the core wire 13a of the lead wire 13 is exposed, and the tip exposed portion is removed. Only the solder was applied to only the core, and thereafter, as shown in FIG. 5B, the core wire 13a having a specified dimension required for welding was exposed. By doing so, it is possible to preferably prevent the strand of the core wire from being disturbed.

[0014]

As described above, according to the present invention, by soldering the core wire of the lead wire in advance, the solder melted by the heat at the time of welding goes around to the connection portion, so that the lead wire is connected to the terminal. The connection strength is further improved. Also,
By removing the insulating coating only on the tip part and soldering up, it is possible to avoid disturbing the strands of the core wire, so the welding workability does not deteriorate and it is sandwiched between the terminals during welding. Since the wire does not stick out when pressure is applied by the electrode, it is not necessary to reduce the actual contact area of the lead wire with the terminal.

[Brief description of the drawings]

FIG. 1 is a perspective view of an electromagnetic sensor according to the present invention.

FIG. 2 is a vertical sectional view showing a state in which a sensitive element portion and a collar are set in a mold.

FIG. 3 is a perspective view of a main part of a sensitive element section.

FIG. 4 is a vertical sectional view showing a state in which a sensitive element portion and a collar are molded in a mold.

FIG. 5 is an explanatory diagram of soldering of the lead wire to the core wire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electromagnetic sensor 2 Sensitive element part 3 Housing part 4 Mounting stay part 5 Cable extension part 6 Metal collar 7 Bobbin 8 Terminal member 9 Coil 10 Pole piece 11 Permanent magnet 12 Yoke 13 Lead wire 14 Conductive wire 15 Conductive wire holding portion 16 Lead wire holding Part 17 Holding groove 18 Cable retainer 19 Lower mold 20 Upper mold 21 Resin injection gate

Claims (2)

[Claims] 1. A lead wire connecting method for welding a core wire to a terminal by electric resistance heating, wherein a soldering process is performed in advance on a welded portion of the core wire. 2. The lead wire according to claim 1, wherein the insulating coating having a specified dimension necessary for welding is removed after soldering is performed in a state where the insulating coating only on the tip end portion of the core wire is removed. How to connect.