JPH0610570Y2 - Lead wire for electromagnetic relay - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a lead wire used in an electromagnetic relay.

[Prior art and its problems]

The electromagnetic relay operates the switch lever by the magnetic force of the electromagnet to open and close the electric circuit.The lead wire is connected to the switch lever and the electrode terminals around the switch lever are connected to the electromagnet or the electric circuit. Each wire is soldered. The characteristics required for these lead wires are the appropriate flexibility and good solderability required during the assembly and processing of electromagnetic relays, and the excellent vibration fatigue resistance against frequent actuation of the switch lever. Repeated bending characteristics.

Therefore, conventionally, lead wires having various structures have been provided in order to satisfy many of the above-mentioned various characteristics. As a typical example of these lead wires, a large number (for example, 19 wires) of annealed copper thin wires (diameter of about 0.1 mm) are twisted together for flexibility, and are bundled together on the outer surface thereof. There is known an annealed copper stranded wire in which a tin plating layer and then an insulating layer of vinyl chloride are formed, or a copper alloy stranded wire in which a thin wire in the annealed copper stranded wire is replaced by an annealed copper alloy wire.

However, in the above-mentioned annealed copper stranded wire, while flexibility and solderability are both good, on the other hand, when assembling the electromagnetic relay, the annealed copper stranded wire that is soldered may have extreme bending.
This bending has a drawback in that the wire around the soldered portion pulled by the bending breaks, or the wire breaks easily due to vibration fatigue associated with the operation of the switch lever. In addition, the above copper alloy stranded wire is excellent in terms of vibration fatigue resistance due to the increase in strength due to the addition of alloying components, but the alloying components reduce solderability, and the soldering work compared to annealed copper stranded wires Had the drawback of becoming complicated.

[Purpose of device]

The present invention has been made in order to solve the above-mentioned drawbacks of the conventional lead wires all at once. The electromagnetic relay has good solderability and flexibility, and excellent vibration fatigue resistance and repeated bending characteristics. It is intended to provide a lead wire for use.

[Constitution of device]

In order to achieve such an object, in the lead wire for an electromagnetic relay of the present invention, a copper layer 2 is formed on the outside of the steel wire 1 at a copper coverage of 50 to 80%. A lead wire core is formed by further providing a tin-plated layer 4 on the outside and twisting a large number of thin wires 5 as a whole to form a lead wire core. Further, a plastic insulating coating 6 is coated on the outside of the lead wire core. ing.

〔Example〕

 The present invention will be described below based on the embodiments shown in the drawings.

1 and 2 show an embodiment of the present invention, in which the lead wire R for an electromagnetic relay of this embodiment has a copper layer 2 on the outer side of a steel wire 1 with a copper coverage of 50 to 80%. The tin-plated layer 4 is formed on the outer side of the copper-coated steel wire 3 formed by the above method to form the element wire 5, and the twisted wire formed by twisting a large number of the element wires 5 is used as the plastic insulating coating layer 6 It is constructed by covering with. Note that the copper coverage means the cross-sectional area of the copper-coated steel wire 3 as S _O and the cross-sectional area of the copper layer 2 as S _CU , In the value represented by the formula, or the predetermined length of the copper-coated steel wire 3, it is defined as the ratio of the volume of the copper layer 2 to the volume of the copper-coated steel wire 3.

In the lead wire R for an electromagnetic relay configured as described above, the outer surface of the copper-coated steel wire 3 is the copper layer 2, and when soldering, the copper layer 2 is soldered via the tin-plated layer 4 , The solderability is as good as that of the conventional annealed copper wire. Further, since the core of the wire 5 is a steel wire, it has higher strength than the conventional annealed copper stranded wire and is excellent in terms of vibration fatigue characteristics.
By twisting them together, they have sufficient flexibility. Therefore, the lead wire R has not only good solderability and flexibility but also excellent vibration fatigue resistance and repeated bending characteristics.

In the present invention, the copper coverage is set to 50 to 80% because the conductivity required for the lead wire becomes too small due to the steel wire having a conductivity lower than that of copper when the copper coverage is less than 50%. If the copper coverage exceeds 80%, the ratio of the steel wire 1 that controls the mechanical strength of the wire 5 decreases, causing insufficient strength of the wire 5, which is also disadvantageous in terms of vibration fatigue characteristics. This is because.

[Experimental example]

Diameter of copper coverage (coverage based on cross-sectional area) 65% 0.
A large number of 1 mm soft copper-coated steel wires were prepared, 19 were twisted together to form a stranded wire, and a 0.2 mm thick vinyl chloride coating was applied to this stranded wire to form a coated lead wire. For comparison, a copper lead wire having a diameter of 0.1 mm is twisted and coated in the same manner as in the above-mentioned coated lead wire, and a copper lead wire formed with a coating and a Cr-Zr-Cu alloy wire having a diameter of 0.1 mm are used. As in the case of the coated lead wire, a copper alloy lead wire formed by twisting and coating was prepared. Then, the respective tests as described in (1) to (3) below were carried out for each of these lead wires, and the results are summarized in Table 1.

(1) The vinyl chloride coating on the end of each lead wire was stripped off by 10 mm and immersed in a solder bath for 1 second to perform a wettability test comparing the wettability of solder.

(2) Cut each lead wire into a length of 50 mm, insert the tip of these into an electrode with a hole, solder, and repeat 90 ° reciprocal bending operation to coat the coated steel wire in each lead wire or The copper wire or the Cr-Zr-Cu alloy wire was examined for the occurrence of wire breakage, and a reciprocal bending test was performed to compare the number of times of bending until the wire breakage occurred.

(3) Each of the lead wires was cut into a length of 50 mm, and each was vibrated with an amplitude of 10 mm to perform a vibration fatigue test for examining the fatigue condition.

As is clear from Table 1, the coated lead wire has good solderability and mechanical characteristics, and has extremely excellent characteristics as an electromagnetic relay lead wire.

As the coverage rate, either the one based on the cross-sectional area or the one based on the volume, which has been described in detail, may be used.

[Effect of device]

According to this invention, the copper layer 2 has a copper coverage of 5 on the outside of the steel wire 1.
Outside the copper-coated steel wire 3 formed at a rate of 0 to 80%,
Further, a tin plating layer 4 is provided, and a large number of thin wires 5 as a whole are twisted together to form a lead wire core, and a plastic insulating coating 6 is further coated on the outside of the lead wire core. Since it is configured, 1) compared with the conventional lead wire of annealed copper stranded wire and copper alloy stranded wire, the mechanical properties such as vibration fatigue characteristics and repeated bending characteristics due to the action of the steel wire located at the center of each strand. Improves characteristics, 2) As a whole, multiple small-diameter strands are twisted together, so it is more flexible than one composed of a single wire with a large diameter. 3) Copper coverage is 50- Since it is 80%, it has sufficient conductivity as a lead wire and has sufficient flexibility as a whole even if the center part is a steel wire. 4) Each wire has a tin plating layer Therefore, the solder wettability is good when soldering to the terminals of electronic equipment. There is an effect etc. is.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a cross-sectional view of a lead wire for an electromagnetic relay, and FIG. 2 is an enlarged cross-sectional view of a wire. R: Lead wire for electromagnetic relay, 1 ... Steel wire, 2 ... Copper layer, 3 ... Copper-coated steel wire, 4 ... Tin plating layer, 5 ... Element wire, 6 ... Plastic insulating coating layer.

Claims (2)

[Scope of utility model registration request] 1. A copper layer 2 on the outside of a steel wire 1 has a copper coverage of 50-8.
A copper-coated steel wire 3 formed at a rate of 0% is further provided with a tin plating layer 4 on the outside thereof, and a large number of thin wires 5 are twisted together as a whole to form a lead wire core,
Further, a plastic insulating coating 6 is provided on the outside of the lead wire core.
A lead wire for an electromagnetic relay, which is characterized by being coated with. 2. The lead wire for an electromagnetic relay according to claim 1, wherein the diameter of the wire 5 is 0.1 mm.