JP2002352663A - Cord switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cord switch with hardly increases on-resistance, even if the cord switch is left under a high temperature or high humidity over a long period. SOLUTION: In this cord switch constituted of a cylindrical insulating part 1 made of an insulating body having elasticity and a plurality of bar-shaped conductive parts 21 made of conductors, are provided to face each other in the longitudinal direction on an internal surface of the insulating part 1 and are constituted of at least one or more metal core wires 4 and conductor resin 6 for covering the whole of the core wires 4, plating layers are formed on the surfaces of the metal core wires 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cord switch which operates when pressed, and more particularly to a cord switch which is attached to an opening / closing device having an automatic opening / closing function, such as a door, a window or a shutter.

[0002]

2. Description of the Related Art Opening and closing devices such as doors, windows and shutters having an automatic opening and closing function are widely used in many buildings such as buildings, stores, garages, and automobiles.

[0003] Accordingly, there is a concern that a pinch accident may occur. For this reason, as a measure for preventing the accident, mounting switches on the opening / closing section has been studied.

Conventionally, as a switch used for such a purpose, for example, a cord switch operated by pressing is known.

As the cord switch, a rectangular cord switch as shown in FIG. 6 and a round cord switch as shown in FIG. 7 are known.

As shown in FIG. 6, a square type cord switch 30 includes a quadrangular tubular insulating portion 21 having elasticity,
A gap h ₃ in the longitudinal direction and insulated on the inner surface of the insulating portion 21.
And two bar-shaped conductive portions (electrodes) 22 having a rectangular cross-sectional shape provided to face each other.

As shown in FIG. 7, a round-type cord switch 40 has an elastic tubular insulating portion 31.
And two pairs of rod-shaped conductive portions (electrodes) 32 having a circular cross section and provided on the inner surface of the insulating portion 31 so as to face each other with a gap h ₄ insulated therebetween in the longitudinal direction.

The conductive parts 22 and 3 of these code switches
2 is a conductive resin 2 around core wires 25 and 35 made of copper wire.
6 and 36, and in the conductive portion 32 of the round type code switch, a conductive resin 36 is formed around a core wire 35 in which seven copper wires are twisted.

Furthermore, these code switches 30, 4
The zero conductive portions 22 and 32 are installed in a spiral shape because pressure can be detected from all directions and bending characteristics are improved.

[0010]

However, the above-mentioned conventional cord switches 30 and 40 are used under high temperature or high humidity depending on the use environment, such as for automobiles and outdoor use. If left under moisture for a long time, there is a problem that the on-resistance when the switch is turned on increases.

The main reason for this is that the code switch is
If the core wire is left for a long time under high temperature or high humidity, the surface of the core wire reacts with oxidation or a substance other than oxygen, or causes corrosion, thereby forming an insulating layer or semi-insulating layer between the core wire and the conductive resin. It is considered that the contact resistance increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cord switch which has a small increase in on-resistance even when left at high temperature or high humidity for a long time.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a cylindrical insulating portion made of an insulator having elasticity, and a longitudinal direction formed on the inner surface of the insulating portion made of a conductor. In a code switch comprising a plurality of opposed and provided rod-shaped conductive portions each composed of at least one or more metal core wires and a conductive resin covering the entire core wires, a plating layer is formed on the surface of the metal core wires. It was formed.

According to a second aspect of the present invention, the plating layer is formed on a metal core wire which comes into contact with at least the conductive resin.

According to a third aspect of the present invention, gold, platinum, silver or nickel is used as the plating layer.

According to a fourth aspect of the present invention, the conductive resin has a volume resistance of 100 Ω · cm or less.

According to a fifth aspect of the present invention, the conductive portion is provided spirally on the inner surface of the insulating portion.

According to the above structure, even if the substrate is left under high temperature or high humidity, the plating layer makes it difficult for the insulating layer or the semi-insulating layer to be formed between the metal core wire and the conductive resin. Reduced.

[0019]

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view of a cord switch according to the present invention.

As shown in FIG. 1, this cord switch 1
Numeral 0 is a square type and has a square tubular insulation with elasticity.
Part 1 and a space insulated in the longitudinal direction and on the inner surface of the insulating part 1.
Gap h ₁ Two rod-shaped conductive parts provided opposite to each other
(Electrode) 2.

The conductive portion 2 has a structure in which a core wire 4 is covered with a conductive resin 6 around a copper wire, and is formed in a square cross section. Further, as shown in FIG. 3, the core wire has a plating layer 4b made of gold, platinum, silver or nickel formed on the outer periphery of the copper wire 4a.

The conductive resin 6 has a volume resistance of 100.
Ω · cm or less resin is used.

The conductive portion 2 is spirally installed since pressure can be detected from all directions and bending characteristics are improved.

Next, the operation will be described.

When the code switch 10 shown in FIG. 1 is left under high temperature or high humidity for a long period of time, the plating layer 4b causes oxidation of the surface of the core wire, reaction with substances other than oxygen, corrosion or the like as in the prior art. Is prevented, an insulating layer or a semi-insulating layer is not easily formed between the core wire 4 and the conductive resin 6, and an increase in on-resistance is reduced. Further, since the metal of the plating layer 4b is a stable metal such as gold, platinum, silver or nickel, formation of an insulating layer or a semi-insulating layer can be effectively prevented.

The volume resistance of the conductive resin 6 is 100Ω ·
cm or less, when the contact resistance between the conductive resin 6 and the core wire 4 increases, the rate of increase in on-resistance when the switch is turned on also increases, but the plating layer 4b can efficiently prevent the on-resistance from increasing. .

Next, another embodiment of the present invention will be described.

FIG. 2 is a sectional view of another embodiment of the present invention.

As shown in FIG. 2, the cord switch is of a round type and has a tubular insulating portion 1 having elasticity.
1, and a this inner surface in the longitudinal direction and the conductive portion of the rod-shaped two pairs disposed opposite each other across the gap h ₂ to insulate the insulating portion 11 (electrodes) 12.

The conductive portion 12 has a structure in which a conductive resin 16 is coated around a core wire 14 in which seven copper wires are twisted, and is formed in a circular cross-sectional shape. Further, as shown in FIG. 4, all the core wires are provided on the outer periphery of the copper wire 14a.
A plating layer 14b made of gold, platinum, silver or nickel is formed.

The conductive resin 16 has a volume resistance of 10
A resin of 0 Ω · cm or less is used.

Further, since the conductive portion 12 can detect pressure from all directions and have good bending characteristics,
Four are arranged in parallel and spirally.

With this configuration, similarly to the cord switch shown in FIG. 1, even when left under high temperature or high humidity for a long period, the plating layer 14b allows the core layer 14 and the conductive resin 16 to be located between the core wire 14 and the conductive resin 16. An insulating layer or a semi-insulating layer is not easily formed, and an increase in on-resistance can be reduced.

Further, since the twisted core wires 14 are collectively held by the plating layer 14b, the connectivity when performing solder connection or the like is improved.

As a modification of the code switch of FIG. 2, when the core wire is a stranded wire, as shown in FIG. 5, the non-plated wires and the wires on which the plating layers are formed are alternately arranged. A code switch configured as described above is also conceivable.

Thus, the effect of preventing the formation of the insulating layer or the semi-insulating layer can be obtained by forming the plating layer only on at least the core wire in contact with the conductive resin.

As described above, by providing the plating layers 4a and 14a on the core wires 4 and 14 of the conductive portions 2 and 12, the surface of the core wire is oxidized or reacts with a substance other than oxygen, or the insulating layer or the insulating layer is corroded by corrosion or the like. It is possible to prevent or delay the formation of the insulating layer, thereby preventing or delaying the contact resistance between the core wire and the conductive resin from increasing or delaying the on-resistance when the code switch is turned on. The rise can be reduced.

In the case of an electric wire cable or the like having a structure in which a core is covered with an insulator, it is common to apply a plating layer to the core. The purpose of the present invention is to improve the performance and to prevent the conduction resistance of the core wire itself from decreasing due to oxidation or corrosion of the core wire, but not to prevent the contact resistance of the core wire surface from increasing as in the present invention.

In consideration of the mechanism of the increase in contact resistance described above, many metals are effective as plating metals for the core wire, but silver and nickel are particularly effective. Further, gold or platinum may be used.

This is considered to be because silver or nickel hardly forms an insulating layer or an anti-insulating layer due to oxidation or reaction with another substance or corrosion.

Further, the volume resistance of the conductive resin is 10
When the contact resistance between the conductive resin and the core wire is 0 Ω · cm or less, the rate of increase in the on-resistance is increased, and thus providing a plating layer is effective. One more
It is particularly effective when the resistance is 0 Ω · cm or less. However, when the volume resistance of the conductive resin is 1000 Ω · cm or more, even if the contact resistance between the conductive resin and the core wire increases, the rate of increase in the on-resistance becomes relatively low, and the effect is reduced.

Next, the present invention and the prior art are left under high temperature or high humidity, and the rate of increase of the on-resistance before and after the leaving is compared.

First, Examples 1 to 4 of the present invention and Comparative Examples 1 to 4 of the prior art were manufactured as described below. (Example 1) A code switch of the type shown in FIG.
m prototypes. The core wire was a single copper wire having a diameter of 0.3 mm, and a nickel plating layer having a thickness of about 2 μm was applied to the outer periphery thereof. As the conductive resin around the nickel-plated core wire, one having a volume resistance of 5 Ω · cm was coated. (Embodiment 2) A cord switch of the type shown in FIG.
m prototypes. The core wire used was obtained by twisting seven strands. The element wire was a copper wire having a diameter of 0.127 mm, around which a silver plating layer having a thickness of about 2 μm was applied. Volume resistance is 1Ω · c as conductive resin around silver-plated core wire
m. (Embodiment 3) A cord switch of the type shown in FIG.
m prototypes. The core wire used was obtained by twisting seven strands. The element wire was a copper wire having a diameter of 0.127 mm, around which a silver plating layer having a thickness of about 2 μm was applied. Volume resistance is 1Ω · c as conductive resin around silver-plated core wire
m. (Embodiment 4) A code switch of the type shown in FIG.
m prototypes. The core wire used was obtained by twisting seven strands. The element wire was a copper wire having a diameter of 0.127 mm, around which a tin plating layer having a thickness of about 2 μm was applied. Volume resistance is 1Ω as conductive resin around tin plated core wire
Cm was coated. Comparative Example 1 A cord switch similar to that of Example 1 except that nickel plating was not performed was manufactured. (Comparative Example 2) A cord switch similar to that of Example 2 except that silver plating was not performed was produced. Comparative Example 3 A cord switch similar to that of Example 3 except that silver plating was not performed was produced. (Comparative Example 4) A cord switch similar to that of Example 4 except that tin plating was not applied was produced.

Then, these Examples 1 to 4 and Comparative Examples 1 to
4 is pressed by applying a load of 20 N with a round bar having a tip of φ4 mm and the on-resistance value is measured after 10 seconds. The initial on-resistance is left for a predetermined time under high temperature or high humidity shown below. Later on-resistance was measured.

Examples 1 and 3 and Comparative Examples 1 and 3 were left in a thermostat at 100 ° C. for 5000 hours. Example 2 and Comparative Example 2 were left in a high-temperature, high-humidity bath at 80 ° C. and 95% Rh for 2000 hours. Example 4 and Comparative Example 4 were left in a thermostat at 90 ° C. for 5000 hours.

Table 1 shows the results.

[0048]

[Table 1]

As shown in Table 1, the on-resistance of Example 1 increased about 1.33 times before and after being left in the constant temperature bath, whereas the on-resistance of Comparative Example 1 increased about 56.3 times.

[0050] In addition, Example 2 increased by 1.2 times, while Comparative Example 2 increased by about 333.3 times.

[0051] In addition, Example 3 increased about 1.13 times, while Comparative Example 3 increased about 111.1 times.

In Example 4, the ratio was increased six-fold, while that in Comparative Example 4 was increased approximately 57.9-fold.

From the above results, it can be seen that the formation of the plating layer on the core wire can greatly reduce the increase in the on-resistance when left under various conditions of high temperature or high humidity.

[0054]

As described above, according to the present invention, it is possible to prevent or delay the rise of the on-resistance even when left for a long time under high temperature and high humidity.

[Brief description of the drawings]

FIG. 1 is a sectional view of a square type cord switch showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a round type code switch showing another embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a core wire of the cord switch of FIG. 1;

FIG. 4 is an enlarged sectional view of a core wire of the cord switch of FIG. 2;

FIG. 5 is an enlarged cross-sectional view of a modified example of the core wire of the code switch of FIG. 2;

FIG. 6 is a sectional view of a conventional square type cord switch.

FIG. 7 is a cross-sectional view of a conventional round type cord switch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating part 2 Conducting part 4, 14 Core wire 4a, 14a Copper wire 4b, 14b Plating layer 6 Conductive resin

Claims (5)

[Claims] 1. A cylindrical insulating portion made of an insulator having elasticity, and a plurality of metal core wires made of a conductor and provided on an inner surface of the insulating portion in a longitudinal direction and opposed to each other, and at least one or more metal core wires. A code switch comprising: a rod-shaped conductive portion composed of a conductive resin covering the entire core wire; and a plating layer formed on a surface of the metal core wire. 2. The code switch according to claim 1, wherein the plating layer is formed on at least a metal core wire that contacts the conductive resin. 3. The code switch according to claim 1, wherein gold, platinum, silver, or nickel is used as the plating layer. 4. The conductive resin has a volume resistance of 100 Ω · c.
The cord switch according to any one of claims 1 to 3, wherein m is equal to or less than m. 5. The cord switch according to claim 1, wherein said conductive portion is provided spirally on an inner surface of said insulating portion.