JPH0323623Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention consists of three layers of nickel, copper, and nickel on the outer periphery of a ferromagnetic material lead wire made of a nickel-iron alloy.
This invention relates to a reed switch with a multi-layered plating layer.

[Conventional technology]

The tips of two lead wires made of ferromagnetic material, at least one of which is a flat spring part, are sealed in a glass tube filled with inert gas with the ends facing each other as contacts, and the other ends of the lead wires are placed outside the glass tube. The reed switch derived from this method has been widely used in the past. The lead wire commonly used in reed switches is made by cutting a fine wire of nickel iron alloy containing 52% nickel (Ni) with a diameter of about 0.6 mm to the required length, and cutting the flat contact part at the tip into a thick wire. flat,
The spring flat part closer to the center is formed into a thinner flat part. Further, both of these flat portions are plated with gold, and the flat contact portion is plated with rhodium or ruthenium to form a ferromagnetic lead.

[Problem that the invention attempts to solve]

Conventional lead wires use expensive plating materials such as gold, rhodium, or ruthenium, and during plating, the thin formed lead wire is held and the flat contact and spring parts are suspended and plated. It must be immersed in a tank and plated with great care, which results in high processing costs. Therefore, the lead wire is expensive, the cost of the reed switch is high, and it is difficult to obtain an inexpensive reed switch.

[Means for solving problems]

The present invention eliminates such drawbacks of the conventional reed switch, which is formed by arranging the tips of two lead wires made of ferromagnetic material to serve as contacts, sealing them inside a glass tube, and leading the other ends out of the glass tube. , nickel plating to the required thickness and copper plating on top of that,
The reed switch is equipped with a lead made of a nickel-iron alloy wire material, which is further coated with a triple layer of nickel plating, drawn to the required wire diameter, cut, and heat treated.

[Effect]

Compared to the conventional method in which the lead of a reed switch is formed into a linear shape and then plated, it is first plated, then linearly processed, cut, and heat treated, making the plating process easier and less expensive.

〔Example〕

1 and 2 show a front view of a reed switch according to the present invention and a sectional view of the reed.

As shown in the drawing, there are contact flat parts 1 that face each other at the tips of the lead wires 1 and 1' of the reed switch and serve as contact points.
3, 13', a spring flat part 12 that allows the contact to move, and a stationary flat part 12',
The thin wire portions 11 and 11' that are sealed with the sealing portion 51 of the glass tube 5 and guided to the outside are used as terminal wires. In addition, these vertical sections are as shown in Figure 2, and the terminal wire 1
1, 11' are circular like a, spring flat parts 12,
12' is a long ellipse like b, contact flat part 13,
13' is a short ellipse like c. This Ni52%
Nickel iron alloy base 2 containing Nickel 3,
It is covered with three plating layers consisting of copper 4 and a nickel plating layer 5 on top of it. This copper plating layer 4 prevents an increase in contact resistance, and the outermost nickel plating layer 6 prevents cold welding.

Incidentally, in the case of a two-layer structure consisting of a nickel plating layer and a copper plating layer, diffusion occurs between the nickel and copper, but if this diffusion makes the surface copper plating layer rich in nickel, the contact resistance increases. On the other hand, if nickel does not diffuse too much, a cold welding phenomenon will occur. Although inconveniences may occur depending on the state of diffusion, the nickel plating layer,
By adopting a three-layer structure consisting of a copper plating layer and a nickel plating layer, diffusion control in the surface layer becomes easier than in the case of a two-layer structure, and a desired diffusion state can generally be obtained.

The lead wires 1, 1' according to the present invention are manufactured as shown in the process diagram of FIG. A nickel-iron alloy wire rod with a wire diameter of about 6 mm is subjected to base plating with nickel in the step shown in 7, and then copper is plated on top to a specified thickness.
Furthermore, three layers of nickel are plated to a predetermined thickness. The wire material plated in these three layers is drawn into a thin wire with a wire diameter of about 0.6 mm by a wire drawing process 8. These thin wires are the contact flat parts 13, 13' and the spring flat part 1.
2 and 12' are pressed to have a circular cross section, and a forming/cutting process 9 is performed to cut them into a predetermined length. Furthermore, a heat treatment 10 is performed for diffusion between each layer, and lead wires are formed.

The lead according to the present invention does not use any precious metal as a plating material, the cost of the plating material is low, and the plating process 7 is performed in the state of the wire, so the process is simple and the cost can be reduced, and a significantly inexpensive reed switch can be obtained.

[Effect of idea]

As described above, according to the present invention, unlike the conventional method in which the base material 3 is formed into a lead wire and then plated with gold, rhodium, etc., the nickel-iron alloy wire is plated with copper and nickel. Since lead wires that have been subjected to wire drawing and heat treatment are used, an extremely inexpensive reed switch can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an external front view of an embodiment of the reed switch according to the present invention, and FIG. 2 is a longitudinal sectional view of the lead in FIG. Cross-sectional view of the spring flat part in c
3 is a cross-sectional view of the flat contact portion taken along line C-C, and FIG. 3 is a manufacturing process diagram of the lead according to the present invention. In addition, 1, 1'... lead, 2... nickel iron alloy base, 3... nickel plating layer, 4... copper plating layer, 5... glass tube, 6... nickel plating layer, 7
... Plating processing, 8 ... Wire drawing processing, 9 ... Molding and cutting processing, 10 ... Heat treatment, 11, 11' ... Terminal wire (fine wire part), 12, 12' ... Spring flat part, 13,
13'...Contact flat part, 51...Sealing part with glass.

Claims (1)

[Scope of utility model registration request] Lead wires 1, 1' made of ferromagnetic material, at least one of which is a spring flat part, and contact flat parts 13, 13' whose tips are opposed and serve as a contact point are enclosed in a glass tube 5, and the lead wires are In the reed switch, the ends opposite to the contacts 1 and 1' are drawn out of the glass tube to form terminal wires 11 and 11', respectively, and the lead wires 1 and 1' and the contact portion 13 sealed in the glass tube are , 13' are coated with triple plating layers of nickel, copper, and nickel.