JP2002063828A - Cord switch and rubber cover for the cord switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cord switch and a rubber cover for a cored switch, that are low cost and are equipped with proper balance, with impact durability and permanent compression set from a high temperature to a low temperature. SOLUTION: A rubber cover 20 made of thermoplastic urethane rubber is covered on the cord switch body 10, that is composed of a cylindrical insulating portion 1 made of an insulating body having elasticity and plural pieces of bar-shape conducting portion 3 made of conducting body, which are provided opposed to each other in the longitudinal direction on the inner face of the insulating portion 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

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

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

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

The cord switch includes a rectangular cord switch as shown in FIG. 5 and a round cord switch as shown in FIG.

As shown in FIGS. 5 and 6, these cord switches have gaps h ₁ and h ₂ which are elastic and insulated at the center.
Insulating portions 1 and 21 made of a cylindrical insulator formed with
A code switch body 10 composed of a plurality of rod-shaped conductive portions (electrodes) 3 and 23 which are made of a conductor and are provided on the inner surface of the insulating portions 1 and 21 along the longitudinal direction thereof and provided at appropriate intervals to face each other. As shown in FIGS. 7 and 8, rubber covers 50, 60 are provided to protect the cover from being damaged when it is attached to the opening / closing section, to absorb the shock caused by opening / closing, and to support and fix it. Has been used.

In the case of a square type cord switch,
The insulating section 1 is formed in a substantially square cross section, and two conductive members 3 are arranged on opposing inner surfaces.

In the case of a round type code switch,
The insulating portion 21 has a substantially circular cross section, and a total of four conductive members 23 are arranged at equal intervals in the circumferential direction of the inner surface and facing each other two by two.

The rubber cover for the code switch is formed of a cylindrical elastic body having accommodating holes 50h, 60h of substantially the same shape formed in accordance with the outer shapes of the code switch bodies 10, 30, and FIG. As shown, for example, the rubber cover 50 for a rectangular cord switch has a substantially rectangular cross section of the accommodation hole 50h so as to accommodate the rectangular cord switch body 10 of FIG.
As shown in FIG. 8, the round rubber cover 60 for the cord switch is the same as the round cord switch body 30 shown in FIG.
The cross-section of the housing hole 60h is formed in a substantially circular shape so that can be stored.

The rubber covers 50 and 60 are
A crosslinked rubber such as EP or CR is used as a material, and is often manufactured by extrusion.

[0011]

However, if a cross-linked rubber is used as a material, a cross-linking step is required after the extrusion, so that the number of operations increases by one.
Time and costs increase.

When a cord switch is attached to the opening / closing portion of the above-mentioned opening / closing device, the rubber cover is subjected to bending after extrusion / crosslinking in order to attach the rubber cover in close contact with a bent shape or the like of the other party to be attached. It is expected that However, since the rubber cover is cross-linked at the time of bending, in order to add a bending habit after cross-linking, as shown in FIG. 8, a holding portion 61 such as a molding process for holding the bent state is formed. And installation is difficult. Therefore, it is conceivable to use a thermoplastic elastomer which does not require a crosslinking step and is easy to bend as a material of the rubber cover. However, a material having these characteristics has not been proposed.

For this reason, impact durability from high to low temperatures,
A cord switch having a good balance of compression set and the like could not be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cord switch and a rubber cover for the cord switch which are low in cost and have a good balance of impact durability and compression set from high to low temperatures.

[0015]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a tubular insulating portion made of an insulator having elasticity, and an inner surface of the insulating portion made of a conductive material, which is provided in a longitudinal direction. A cord switch body composed of a plurality of rod-shaped conductive portions provided to face each other is covered with a rubber cover made of thermoplastic urethane rubber.

According to a second aspect of the present invention, there is provided a cylindrical insulating portion made of an insulator having elasticity, and a plurality of rod-shaped conductive portions made of a conductive material and provided on the inner surface of the insulating portion in a spiral and parallel curve shape. And a rubber cover made of thermoplastic urethane rubber.

According to a third aspect of the present invention, the thermoplastic urethane rubber has a hardness of 60 to 90.

According to a fourth aspect of the present invention, there is provided a cylindrical insulating portion made of an insulator having elasticity, and a plurality of rod-shaped conductive portions made of a conductor and provided on the inner surface of the insulating portion so as to face each other in the longitudinal direction. The rubber cover for a cord switch to be put on the cord switch body is made of thermoplastic urethane rubber.

According to a fifth aspect of the present invention, there is provided a cylindrical insulating portion made of an insulator having elasticity, and a plurality of rod-shaped conductive portions made of a conductor and provided on the inner surface of the insulating portion in a spiral and parallel curve shape. The material is a thermoplastic urethane rubber in a rubber cover for a cord switch to be put on a cord switch comprising a part.

According to a sixth aspect of the present invention, the thermoplastic urethane rubber has a hardness of 60 to 90.

According to the above configuration, a cross-linking step is not required at the time of manufacturing, and even when bending is performed after extrusion, the material is easily deformed by heating, thereby facilitating the processing.

[0022]

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 square type cord switch as an embodiment of the present invention.

As shown in FIG. 1, a cord switch of a square type is attached to an opening / closing portion of an opening / closing device such as a door, a window, or a shutter having an automatic opening / closing function, and is actuated when pressed. And a rubber cover 20 provided over the cord switch body 10.

The cord switch body 10 has a substantially rectangular cross section, and has an insulating portion 1 made of a cylindrical insulator having elasticity and a gap h ₁ formed at the center for insulation.
It is composed of two rod-shaped conductive portions (electrodes) 3 which are made of a conductive material and provided on the inner surface of the insulating portion 1 along the longitudinal direction thereof at appropriate intervals to face each other.

As shown in FIG. 3, the rubber cover 20 for the code switch is formed of a cylindrical elastic body having a storage hole 20h having a substantially square cross section in accordance with the outer shape of the code switch body. I have.

Specifically, this elastic body is a thermoplastic urethane rubber, and the one having a hardness of 65 to 85 is optimal. This is because if the rubber hardness exceeds 90, it becomes too hard and is hardly deformed even when an external pressure is applied, and the reactivity of the cord switch is impaired. This is because it is difficult to make it technically and the cost rises.

Next, a method of manufacturing a rubber cover according to the present invention will be described together with its operation.

In manufacturing the rubber cover 20, a thermoplastic urethane rubber is extruded to form a rubber cover having a desired shape. Thermoplastic urethane rubber does not require a cross-linking step after molding, making it easier to manufacture,
Production time and cost can be reduced.

When attaching the cord switch to the opening / closing device, the cord switch body 10 is accommodated in the accommodating hole 20h of the rubber cover to form the cord switch, and then the cord switch is bent in accordance with the shape of the mating partner. At this time,
Since the material of the rubber cover 20 is urethane rubber,
Since it is heated and easily deformed, the mounting property is improved.

Further, even after mounting, the urethane rubber has a good balance of characteristics such as impact durability and compression set from high to low temperatures, and therefore, according to the present invention, it has excellent impact durability and compression set. A code switch can be provided.

The thermoplastic urethane rubber is also effective in recycling.

Next, FIG. 2 shows a sectional view of a round type cord switch as another embodiment.

As shown in FIG. 2, the round type code switch is composed of a code switch main body 30 which is activated when pressed, and a rubber cover 40 provided over the code switch main body 30. .

The cord switch body 30 has a substantially circular cross section, and has an insulating portion 21 made of a cylindrical insulator having elasticity and a gap h ₂ formed at the center for insulation.
And four bar-shaped conductive portions (electrodes) 23 which are made of a conductor and provided on the inner surface of the insulating portion 21 so as to face each other two by two.

Although not shown, these four conductive portions 23 are arranged in a spiral shape and a parallel curved shape along the longitudinal direction.

As shown in FIG. 4, the rubber cover 40 for the code switch is formed of a cylindrical elastic body having a storage hole 40h having a substantially circular cross section in accordance with the outer shape of the code switch body 30. ing.

Specifically, the elastic body is a thermoplastic urethane rubber, and the one having a hardness of 65 to 85 is optimal. This is because if the rubber hardness exceeds 90, it becomes too hard and is hardly deformed even when an external pressure is applied, and the reactivity of the cord switch is impaired. This is because it is difficult to make it technically and the cost rises.

According to the present invention, the same effects as those of the present embodiment can be expected even with this configuration. Further, even when the round type cord switch is twisted when attached to the switchgear, the opposing conductive portions 23, 23 are arranged side by side in the opening / closing direction of the switchgear at any position in the longitudinal direction. Therefore, it can be mounted so that it can be reliably operated by pressing.

In the present embodiment, the rubber cover 2
As a manufacturing method of 0, 40, the case of molding by general extrusion has been described. However, when a bent portion or the like is formed on the rubber covers 20, 40, molding by injection or the like may be used. Even in this case, the thermoplastic urethane rubber has advantages such as not requiring a crosslinking time.

[0041]

Next, a more specific embodiment of a rubber cover for a cord switch will be described in detail together with a comparative example.

Example 1 A thermoplastic urethane having a rubber hardness of 80 (Elastollan ET880) manufactured by Takeda Birdish Urethane Industry Co., Ltd. was extruded into a 50 mm extruder (L / D = 2).
Extruded at a temperature of 190 ° C. in 5) to form a square rubber cover.

(Example 2) Thermoplastic urethane having a rubber hardness of 74 (Milactran E6 manufactured by Nippon Miractran Co., Ltd.)
75MNAT) was extruded with a 40 mm extruder (L / D = 20) at a temperature of 185 ° C. to form a round rubber cover.

Thereafter, in order to bend the rubber cover, a part of the rubber cover is fitted into a bent metal frame having a radius of 20 mm preheated to 80 ° C., and the metal frame is heated to a temperature of 180 ° C. and pressed to 70 tons. Between 20 seconds, then 50
It cooled to ° C and produced the rubber cover. At this time, the bent portion was formed to have a radius of 20 mm.

(Comparative Example 1) A square rubber cover was molded in the same manufacturing method as in Example 1 using a styrene-based thermoplastic elastomer (Lavalon SE6400, manufactured by Mitsubishi Chemical Corporation) as a material.

Comparative Example 2 EPDM having the composition shown in Table 1 was extruded at a temperature of 105 ° C. using a 40 mm extruder (L / D = 15) to form an unvulcanized rubber cover. After that, UHF
(5 kw belt type)-The rubber cover was vulcanized through an HA continuous cross-linking line to form a round rubber cover.

Thereafter, in order to bend the rubber cover, a part of the rubber cover is fitted into a bent metal frame having a radius of 20 mm preheated to 80 ° C., and the metal frame is heated to a temperature of 180 ° C. and pressed to 70 tons. Between 20 seconds, then 5
After cooling to 0 ° C., a rubber cover was produced. At this time, the bent portion was not formed into a bent shape with a radius of 20 mm.

Comparative Example 3 EPDM having the composition shown in Table 1 was extruded with a 40 mm extruder (L / D = 15) at a temperature of 105 ° C. to form an unvulcanized rubber cover. After that, UHF
(5 kw belt type)-The rubber cover was vulcanized through an HA continuous cross-linking line to form a round rubber cover.

Thereafter, in order to bend the rubber cover, a part of the rubber cover was fitted into a bent metal mold frame having a radius of 20 mm preheated to 60 ° C., and 2 g of the compounded rubber shown in Table 2 was weighed. Put the gold frame, 18
It was heated to a temperature of 0 ° C. and left in a 70-ton press for 10 minutes to vulcanize the mold portion to produce a rubber cover. At this time, the bent portion was formed to have a radius of 20 mm.

[0050]

[Table 1]

[0051]

[Table 2]

Next, the impact durability and bending workability of the present invention will be described.

In the impact durability test, a rod having a diameter of 4 mm was used.
At a temperature of 80 ° C. and a force of 160 N at intervals of 2 seconds 3
This was done by repeating 0 hits. Then, the rubber cover was visually inspected for any cracks or tears that would hinder the function, and the impact durability was determined. The results are shown in Table 3 together with items related to the manufacturing process.

[0054]

[Table 3]

As shown in Table 3, Examples 1 and 2
And the comparative example 2 and the comparative example 3 have cracks and tears in the rubber cover,
Comparative Example 1 had cracks, while no damage was found that would impair the function.

From this, it was confirmed that the present invention has high impact durability.

Further, regarding the bending workability, Example 2
And Comparative Example 2 and Comparative Example 3 were used to determine the ease of the processing method and the stability of the bent portion.

As a result, Example 2 and Comparative Example 2 are easy to process, but Comparative Example 3 requires a step of forming a mold portion, and thus can be said to be poor in workability.

Further, as to the state of forming the bent portion, in Example 2 and Comparative Example 3, the shape of the bent portion was stably maintained. However, in Comparative Example 2, the radius of the bent portion became 1 after one day from the production.
It returned to 00 mm.

From this, it was confirmed that the present invention was excellent in bending workability.

[0061]

In summary, according to the present invention, the use of a thermoplastic urethane rubber as a material eliminates the need for a cross-linking step, thereby improving workability and reducing manufacturing costs.

Further, according to the present invention, when bending is performed after extrusion, the processing time can be shortened and the formability is good, so that the workability is improved.

Further, according to the present invention, a rubber cover having a good balance of impact durability and compression set from high to low temperatures can be formed, so that a highly reliable cord switch can be provided.

[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 a schematic view of the square type rubber cover of FIG. 1;

FIG. 4 is a schematic view of a round rubber cover of FIG. 2;

FIG. 5 is a sectional view of a square type cord switch.

FIG. 6 is a sectional view of a round type cord switch.

FIG. 7 is a schematic view of a conventional rectangular rubber cover.

FIG. 8 is a schematic view of a conventional round rubber cover.

[Explanation of symbols]

 1,21 Insulating section 3,23 Conducting section 10,30 Cord switch body 20,40 Rubber cover

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Yoshikazu Hayakawa 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture F-term in the Hidaka Plant of Hitachi Cable, Ltd. (Reference) 5G006 FB39 FD02 LG02 5G023 AA12 CA50

Claims (6)

[Claims] 1. A cord switch comprising: a tubular insulating portion made of an insulator having elasticity; and a plurality of rod-shaped conductive portions made of a conductor and provided on an inner surface of the insulating portion so as to face each other in a longitudinal direction. A cord switch comprising a main body covered with a rubber cover made of thermoplastic urethane rubber. 2. A cord comprising: a cylindrical insulating portion made of an elastic insulator; and a plurality of rod-shaped conductive portions made of a conductor and provided on the inner surface of the insulating portion in a spiral and parallel curve shape. A cord switch comprising a switch body covered with a rubber cover made of thermoplastic urethane rubber. 3. The thermoplastic urethane rubber has a hardness of 60.
3. The cord switch according to claim 1, wherein the number is from 90 to 90. 4. 4. A cord switch comprising: a cylindrical insulating portion made of an elastic insulator; and a plurality of rod-shaped conductive portions made of a conductor and provided on an inner surface of the insulating portion so as to face each other in a longitudinal direction. A rubber cover for a code switch, which is covered with a main body, wherein the material is a thermoplastic urethane rubber. 5. A cord comprising: a tubular insulating portion made of an insulator having elasticity; and a plurality of rod-shaped conductive portions made of a conductor and provided on the inner surface of the insulating portion in a spiral and parallel curve shape. A rubber cover for a cord switch, wherein the material is a thermoplastic urethane rubber. 6. The thermoplastic urethane rubber has a hardness of 60.
The rubber cover for a cord switch according to claim 4 or 5, wherein