JPH0125463Y2 - - Google Patents

Description

[Detailed explanation of the idea]

<Industrial Application Field> The present invention relates to a pressure-sensitive striatum that is uniformly sensitive to pressure at all successive positions along its length. <Prior art and its problems> As a pressure-sensitive wire body, Japanese Utility Model Publication No. 36-8356 describes a method in which an insulating string is spirally wound around a conductor, and a conductive tube, a metal wire braid, and a resilient wire are wrapped around the conductor. A "pressure-sensitive electric wire with an external sheath" has been proposed, but as can be seen from its structure, the pressure-sensitivity characteristics vary along the length, the sensitivity is slow, and it cannot be used repeatedly for a long period of time. There are problems such as the sensitivity becoming uncertain during the process. Furthermore, the conductor and the metal wire braid are brought into contact by the conductive tube bending in response to pressure and coming into contact with the conductor, but since the bending occurs from one direction, there is also the problem of poor sensitivity characteristics. In addition, Japanese Patent Application Laid-Open No. 146184/1984 proposes a ``wire switch in which electric poles are placed on both sides of silicone rubber mixed with metal particles.'' Since the sensor is sensitive to a drop in energy, there are problems such as malfunctions if it is bent or subjected to vibration. <Purpose of the invention> In view of the above points, the purpose of the present invention is to provide a pressure-sensitive wire body that can withstand repeated use over a long period of time, does not malfunction due to vibration or bending, and has good sensitivity characteristics. do. <Means for solving the problem> In order to solve the above problems, in the present invention, a conductive elastic layer is provided on the circumference of the flexible electric conductor, and an insulating fiber thread is arranged in a specific braid on top of the conductive elastic layer. It consists of two densely braided core wires twisted together at a specific twisting pitch, with a protective outer covering around them. <Function> The function of the present invention is to provide a conductive elastic layer on a flexible electrical conductor, and twist two core wires on which insulating fiber yarns are braided at a specific braiding density at a specific pitch. As a result, when pressure is applied, the conductive elastic layers of both core wires protrude from both sides of the gap between the braids, allowing smooth conduction between them, and when the pressure is removed, the conductive elastic layers return to their original state. on the other hand,
Since the braided layer is provided around the flexible electrical conductor,
The conductive elastic layer does not protrude into the braid due to bending or the like, that is, it does not protrude unless it receives local pressure, and there is no malfunction. Therefore, the variation in pressure sensitivity characteristics in the longitudinal direction is small, it can withstand repeated use over a long period of time, and has bending resistance. In addition, the reason why the braid density is set at 17 to 40 in the registered claims is that when two core wires are twisted, the overlapping part of the braid will have twice the braid density, and the conductive elastic material will be able to reach an appropriate amount from the gap between the braids. This is the range in which the conductive elastic layer protrudes and becomes conductive when pressurized and can be restored when the pressure is removed. When this happens, the movement becomes slow. The reason why the twisting pitch is set to 10 to 30 times the layer core diameter is because the pressure sensitivity is not good even if the pitch exceeds either of the two. <Example> Next, an example of the present invention will be described with reference to the drawings. As shown in Figure 1, 0.8 mm of conductive silicone rubber with a specific volume resistivity of 4 Ω-cm is placed on a 2 mm ² flexible electrical conductor 1 made by twisting seven 0.6 mm tin-plated annealed copper wires.
A conductive elastic layer 2 is formed by extrusion molding and cross-linking to a thickness of 1.5 mm, and an insulating braided layer 3 is provided thereon as shown in Table 1. 35
Twist them together with jute 5 interposed at twice the pitch, and apply polyester nonwoven tape 6 (0.15
The protective coating 7 is made of a polyvinyl chloride mixture with good elasticity and flexibility.

[Long-term repeated operation test]

The pressure-sensitive wire body a of the present invention was laid on the floor, the circuit was configured as shown in Figure 2, a 40 cm long plate was placed on top of the pressure-sensitive wire body a, and a pressure of 15 kg was applied 100,000 times. Pressurized. In FIG. 2, 10 is a switch, 11 is a power source, and 12 is a relay for detecting continuity of the pressure-sensitive wire body a. As a result, those related to the present invention (Samples 2, 3,
Sample 4) was normally sensitive to pressure, but sample 1 with a low braid density had unclear opening and closing of the circuit and eventually shorted. [Pressure Sensitive Test] When the circuit shown in Figure 2 was constructed using each sample in Table 1 and pressure was applied as described above, the product according to the present invention was able to achieve a pressure of 15 kg from a resistance of ∞ when no pressure was applied. 60~
400Ω, which was clearly sensitive, but with a large braid density (Sample 5), the reduction in resistance required for the relay 12 to operate was not observed. [Bending resistance] We investigated whether malfunctions occur when the pressure-sensitive wire body a according to the present invention is wound twice around a mandrel with a diameter twice its own diameter. On the other hand, the one with a low braid density (Sample 1) malfunctioned. <Effects> As explained above, according to the present invention, it is possible to obtain a pressure-sensitive wire body that can withstand repeated use over a long period of time, has good pressure sensitivity, and is highly resistant to bending and vibration.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a pressure-sensitive wire body according to the present invention, and FIG. 2 is an explanatory diagram of an effect confirmation test. 1... Flexible electrical conductor, 2... Conductive elastic layer,
3... Insulating fiber thread, 4... Cord wire, 7... Protective jacket, a... Pressure-sensitive striatum.

Claims (1)

[Claims for Utility Model Registration] (1) Two core wires with a conductive elastic layer and a braided layer of insulating fiber yarn sequentially provided on the circumference of a flexible electrical conductor are twisted together, and an unprotected wire is twisted around the flexible conductor. A pressure-sensitive striatum characterized by being provided with a covering. (2) A pressure-sensitive filament according to claim (1) of the utility model registration, characterized in that it is formed by braiding insulating fiber yarns at a braiding density of 17 to 40. (3) A pressure-sensitive wire body according to claim (1) or (2) of the utility model registration claim, characterized in that the core wire twisting pitch is 10 to 30 times the layer core diameter.