JP2000348565A - Cord-like pressure-sensitive switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a highly reliable cord-like pressure-sensitive switch, which is simple in structure but reacts surely to pressure from any direction, can perform on-off operation and does not malfunction in a bent part. SOLUTION: This pressure-sensitive switch is structured, so that a spacer 2 made of insulating material, an outer conductor 3, and insulation covering 4 are formed on over another on the peripheral surface of an inner conductor 1 continued in the longitudinal direction. When no pressure is applied externally, the inner conductor 1 and outer conductor 3 are insulated spatially by the spacer 2, when an external pressure is applied, the outer conductor 3 makes an electrical contact with the inner conductor 1 to establish the electrically continuity condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has a simple structure, and can perform an on / off operation in response to pressure from all directions without fail.
The present invention relates to a highly reliable and inexpensive cord-shaped pressure-sensitive switch that does not cause a malfunction in a bent portion.

[0002]

2. Description of the Related Art In recent years, the automation of various machinery and equipment has been rapidly advanced due to the development of electronic devices, and accordingly, various pressure-sensitive sensors have become increasingly important parts for the purpose of ensuring safety. I have. For example, in a mechanical device having an opening / closing member such as a door (door) or a lid, a sensor for detecting that an object, a person, or the like is trapped when the opening / closing member is closed may be required. For this type of sensor,
Conventionally, various configurations have been proposed and put to practical use. Among them, for example, a pressure-sensitive sensor for opening and closing a door at an entrance of a house, a store, etc. For example, a cord-shaped pressure-sensitive switch is used.

An example of a cord-shaped pressure-sensitive switch is disclosed in, for example, JP-A-7-96740. In this device, a rubber elastic member is interposed between a pair of opposing conductive members arranged in parallel to form a gap between the two conductive members, and both conductive members are fixed to the rubber elastic member. It is. When an external force acts on the conductive member, the elastic member made of rubber is deformed, so that the two conductive members come into contact with each other, and a current can be supplied.

Since the cord-shaped pressure-sensitive switch has a structure in which a pair of conductive members are arranged in parallel as described above, when a pressure is applied in a direction perpendicular to the parallel direction, the conductive members are switched. Although the pressure can be detected by reliable contact, the pressure cannot be detected when pressure is received in the horizontal direction with respect to the parallel direction. Therefore, the detection direction is limited to only one direction, and the wiring pattern is greatly limited.

When the cord-shaped pressure-sensitive switch is wired in a bent state, a compressive stress in the direction of crushing the cord-shaped pressure-sensitive switch is generated in addition to the bending stress,
In addition, since the rigidity of the elastic member is lower than that of the conductive member, the elastic member located at the bent portion is crushed. In this case, there is a possibility that the two conductive members come into contact and malfunction.

In order to solve the problem relating to such a malfunction, for example, Japanese Patent Application Laid-Open No. 9-28893 has been proposed.
There is a cord-shaped pressure-sensitive switch disclosed in Japanese Unexamined Patent Publication No. 1 (1993). This is provided with an elastically deformable coating tube and three elastically deformable conductive members extending in the longitudinal direction of the coating tube, and an insulating gap for forming an insulating gap between the conductive members. A member (spacer), one of the three conductive members is used as a first member, and when pressure is applied from the outside, the remaining conductive members (second member or third member) become first members. The pressure is detected by contact.

In this cord-shaped pressure-sensitive switch, even when the cord-shaped pressure-sensitive switch is wired, the conductive members can be padded with each other, and even when a bending moment acts on the cord-shaped pressure-sensitive switch, the conductive member remains Since each bends independently at the same curvature, the compressive stress in the direction of crushing the insulating gap formed between the conductive members is reduced,
Malfunction due to contact between the conductive members can be prevented.

[0008]

However, this cord-shaped pressure-sensitive switch also has the following problems. That is, in the cord-shaped pressure-sensitive switch, when pressure is applied only to the spacer portion, the conductive members may not contact each other due to the presence of the spacer, and may not respond to the pressure. In addition, in order to provide spacers between conductive members, a large number of spacers must be provided on the conductive member in advance, or a separate spacer must be prepared and combined with the conductive member. There is a disadvantage that labor is required and the production cost is greatly increased.

The present invention has been made on the basis of such a point. The object of the present invention is to provide an on / off operation which has a simple structure and reliably responds to pressure from all directions. It is an object of the present invention to provide an inexpensive cord-shaped pressure-sensitive switch that can perform the above-described operation and that does not cause a malfunction in a bent portion.

[0010]

According to the present invention, there is provided a cord-shaped pressure-sensitive switch according to the present invention, in which a spacer made of an insulating material, an outer conductor, and an insulating coating are sequentially formed on a circumference of an inner conductor continuous in a longitudinal direction. This is a cord-shaped pressure-sensitive switch that is formed.When no pressure is applied from the outside, the inner conductor and the outer conductor are spatially insulated by a spacer, and when pressure is applied from the outside, the outer conductor is It is characterized by being electrically connected to a conductor to be in a conductive state.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The inner conductor is made of a conventionally known conductor material as it is, or a conductor material coated on the periphery of an elastic core continuous in the longitudinal direction. Specifically, for example, copper, copper alloy, nickel, iron, aluminum, stainless steel, nickel chromium alloy, tin, silver, a single wire of a thin metal wire such as those subjected to a surface treatment of nickel, etc., Stranded wire as it is, or
These metal wires are horizontally wound or braided on the circumference of an elastic core continuous in the longitudinal direction, or a metal foil tape made of the above-described metal material is vertically wrapped or horizontally wound on the circumference of the elastic core continuously in the longitudinal direction. It consists of the thing which did. The metal foil tape may have a configuration in which the above-described metal material is laminated or vapor-deposited on an insulating film.

Here, when a braid of a thin metal wire is selected as the conductive material to be coated on the periphery of the elastic core, other than the method of braiding using the thin metal wire as it is, for example,
A method of braiding using a wire having a structure in which the above-mentioned thin metal wire is horizontally wound around a fiber core made of glass fiber, alumina fiber, polyester fiber, polyamide fiber, polyolefin fiber, or the like; A method of cross-braiding a material and the above-described thin metal wire is also conceivable.

The elastic core is made of, for example, silicone rubber, urethane rubber, natural rubber, SBR, EP rubber, soft PVC,
Polyolefin, a conventionally known general elastic material such as a fluoro rubber, or those extruded into a string or a tube,
It is composed of those obtained by foaming them. In the case where the elastic core is formed in a string shape, a structure in which a tensile member is disposed at the center may be adopted. As the strength member, for example, glass fiber, alumina fiber, polyester fiber, polyamide fiber, polyolefin fiber, stainless steel fiber and the like can be used.

In the present invention, first, a spacer is formed on the periphery of the internal conductor. This spacer functions as a space insulation holding means between the outer conductor and the inner conductor described later. As the spacer, for example, silicone rubber, vinyl chloride resin, polyethylene, polyolefin, fluoro rubber, fluoro resin, urethane resin and the like, extruded in the form of a string or tube, glass fiber, alumina fiber, Polyester fiber,
Examples thereof include a cord made by twisting fiber materials such as polyamide-based fibers and polyolefin-based fibers. These spacers are formed on the circumference of the inner conductor by vertically attaching, horizontally winding or braiding. In this case, it is necessary that the spacers do not completely cover the surface of the inner conductor. Preferably, 50% or more of the inner conductor surface is 95%.
% Is designed to be exposed. If the exposed portion of the internal conductor exceeds 95%, the ability of the spacer to maintain the spatial insulation is reduced, which may cause a malfunction. On the other hand, when the exposed portion of the inner conductor is less than 50%, it is difficult to obtain a reliable electrical contact state (conductive state) between the outer conductor and the inner conductor when pressure is applied from the outside. There is a risk of becoming.

Next, an external conductor is formed by a known method such as longitudinal attachment, horizontal winding, braiding, or the like. As the outer conductor, for example, a thin metal wire or a metal foil tape exemplified as the inner conductor can be used.

Finally, an insulating coating is formed on these circumferences. As the insulating coating material, for example, silicone rubber,
Electrical insulating compositions mainly composed of organic polymer materials such as vinyl chloride resin, polyethylene, polyolefin, fluoro rubber, fluoro resin, urethane resin, and fiber materials such as glass fiber, alumina fiber, silica fiber, and alumina / silica fiber. Is mentioned. When an electrical insulating composition is used as the insulating coating material, it may be formed by extrusion. In addition, depending on the type of the insulating coating material, a crosslinking treatment is appropriately performed. When a fiber material is used as the insulating coating material, it may be formed by braiding or horizontal winding. These may be formed as a single layer, or may be formed as two or more layers.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

[0018]Example 1  In this embodiment, the cord-shaped pressure-sensitive switch having the structure shown in FIGS.
The switch was manufactured according to the following procedure. First, the cross section
3.2mm product^TwoConductor 1 consisting of tin-plated annealed copper wire
On the circumference of a circular cross section of 1 mm in diameter as a spacer 2
Extruded string of polyester elastomer with inner conductor
1 is horizontally wound so that about 75% of the surface is exposed, and
Apply a treatment to give the extruded string a spiral habit
Embodied. Then, on the circumference, a thickness of 20 μm and a width of 1
6mm, copper / P with polyolefin adhesive layer on one side
ET tape (10μm thick, 16mm wide copper foil, thickness
10μm, 16mm width
Vertical conductor molding of the external conductor 3 composed of
At the same time, thicken the composition mainly composed of polyethylene.
Extrusion coating with a thickness of 0.5 mm to form insulation coating 4 and finish off
A cord-shaped pressure-sensitive switch having a diameter of 5.5 mm was obtained.

[0019]Example 2  In this embodiment, a cord-shaped pressure-sensitive switch having the structure shown in FIG.
It was manufactured by the following procedure. First, 0.7m outside diameter
elastic material on the circumference of a tensile strength body consisting of a glass fiber bundle
And extrude silicone rubber to a thickness of 1.5 mm.
Elastic core 1a which has been subjected to hot air vulcanization and is continuous in the longitudinal direction.
Was manufactured. Next, on the circumference of the elastic core 1a, an outer diameter of 0.3
mm tinned soft copper stranded wire 1b at a pitch of about 2mm
The inner conductor 1 was formed by winding. Then, on that circumference,
As the spacer 2, a hole having a circular cross section of 1 mm in diameter is used.
When the surface of the inner conductor 1 is
Wrap horizontally so that about 75% is exposed, and heat-treat at the same time
Add a spiral habit to the extruded cord to integrate the two
Was. Next, a polyol with a thickness of 20 μm and a width of 12 mm
Copper / PET tape with fin-based adhesive layer (thickness 10μ)
m, copper foil of width 12mm, thickness 10μm, width 12mmP
External conductor consisting of ET film)
3 was wound horizontally with the copper foil inside. And finally, this
A composition composed mainly of polyethylene was applied on the circumference to a thickness of 0.5
extrusion coating to form an insulating coating 4 and finish outer diameter 8 mm
A cord-shaped pressure-sensitive switch was obtained.

[0020]Example 3  In this embodiment, the cord-shaped pressure-sensitive switch having the structure shown in FIGS.
The switch was manufactured according to the following procedure. First, the outer diameter
A bullet is wound on the circumference of a tensile strength member consisting of a 0.7 mm glass fiber bundle.
Silicone rubber containing a foaming agent as a conductive material
Extrusion coating at 1.5 mm, hot air vulcanization immediately
A foamed elastic core 1a continuous in the hand direction was manufactured. Then, on
A copper having a thickness of 20 μm and a width of 12 mm is formed on the periphery of the elastic core 1a.
/ PET tape (10μm thick, 12mm wide copper foil,
Laminated on PET film with thickness of 10μm and width of 12mm
Inner conductor by winding 1b horizontally at a pitch of about 10mm
1 was formed. Next, on the periphery thereof, a spacer 2 is formed.
And a polyester elastomer having a circular cross section of 1 mm in diameter
Extrude the stoma and expose about 75% of the surface of the inner conductor 1.
And heat-treated at the same time,
Both parts were integrated by adding an irritating habit. Next, thickness 2
0μm, width 12mm, polyolefin adhesive layer on one side
Copper / PET tape with a thickness of 10 μm and a width of 12 mm
Stretch copper foil on PET film with thickness of 10μm and width of 12mm
The outer conductor 3 made of the above-mentioned components is wound horizontally.
And finally, on these circumferences, mainly polyethylene
The composition is extrusion-coated to a thickness of 0.5 mm to form an insulating coating 4.
A cord-shaped pressure-sensitive switch having a finished outer diameter of 8 mm was obtained.

[0021]Example 4  In this embodiment, a cord-shaped pressure-sensitive switch having the structure shown in FIG.
It was manufactured by the following procedure. First, inner diameter 1.0m
m, silicone rubber rubber extruded to an outer diameter of 2.0 mm
The 5.3th gala on the circumference of the elastic core 1a
Wire and 6 tin-plated soft copper wires with outer diameter of 0.05mm
The number of strokes is 16, the number of possessions is 2,
The inner conductor 1 is formed by applying the braid 1b under the condition of the density 25.
Was. Next, a circle having a diameter of 1 mm is formed on the circumference as a spacer 2.
Extruded polyester elastomer string with a cross section of shape
Horizontally winding so that the surface of the inner conductor 1 is exposed by about 75%,
Simultaneously heat-treated to give the extruded string a spiral habit
Both were integrated. Next, a thickness of 10 μm and a width of 20 mm
Copper / PET te with polyolefin adhesive layer on one side
Copper (10μm thick, 20mm wide copper foil, 10μm thick
m, 20 mm wide PET film)
The external conductor 3 consisting of
And at the same time, a composition mainly composed of polyethylene having a thickness of 0.1 mm.
Extrusion coating at 5 mm to form insulating coating 4 and finish outer diameter 6 m
m cord-shaped pressure-sensitive switches were obtained.

[0022]Example 5  In this embodiment, a cord-shaped pressure-sensitive switch having the structure shown in FIG.
It was manufactured by the following procedure. First, inner diameter 1.0m
m, silicone rubber rubber extruded to an outer diameter of 2.0 mm
The structure shown in FIG.
Using strands, knitting under conditions of 16 strokes, 2 holdings, and 25 density
The set 1b was applied to form the inner conductor 1. In this embodiment,
As braided strand, outer diameter on 5.3th glass fiber 1c
Two 1d 0.05mm tin-plated annealed copper wires are aligned
What was wound horizontally at a pitch of about 1.5 mm was used. Next
And a circular cross section of 1 mm in diameter as a spacer 2 on its circumference
Extruded string of polyester elastomer with inner conductor
1 is horizontally wound so that about 75% of the surface is exposed, and
Apply a treatment to give the extruded string a spiral habit
Embodied. Next, on one side with a thickness of 10 μm and a width of 16 mm
Copper / PET tape with polyolefin adhesive layer (thick
A copper foil having a thickness of 10 µm and a width of 16 mm is
6mm PET film)
Simultaneously while vertically adding and molding the conductor 3 with the copper foil inside
0.5mm thick composition mainly composed of polyethylene
Extrusion coating to form an insulating coating 4 with a finish outer diameter of 5.5 mm
A cord pressure switch was obtained.

Here, in order to evaluate the pressure-sensitive characteristics of the cord-shaped pressure-sensitive switches according to the respective examples obtained as described above, the following tests were performed. First, length 3
A cord-shaped pressure-sensitive switch cut to 00 mm was used as a sample,
The insulating coating on both ends was stripped by about 10 mm to expose the inner conductor from one end and the outer conductor from the other end, respectively, and a digital multimeter was connected between them. Then, on the sample, diameter 15mm, weight 300g
Was placed in a direction perpendicular to the longitudinal direction of the sample, and the presence or absence of energization between the inner conductor and the outer conductor was checked. The number of samples was set to 10. As a result, the samples of all the examples showed a resistance value of 0.1 Ω or less, and it was confirmed that current was supplied between the inner conductor and the outer conductor. In the present example, each sample was rotated in the circumferential direction until the sample was rotated once by 45 °, and the reaction at each location was confirmed. However, energization between the inner conductor and the outer conductor was confirmed at all locations.

Further, in this embodiment, the sample of each embodiment after the above-mentioned test is wound around a mandrel having a diameter of 50 mm, and whether or not there is current between the inner conductor and the outer conductor at the bent portion (whether there is a malfunction). I also checked. As a result, the resistance values of the samples of any of the examples were infinite, and the inner conductor and the outer conductor did not come into contact with each other and did not conduct electricity.

As described above, it can be seen that the cord-shaped pressure-sensitive switch according to each of the embodiments is a highly reliable switch that reliably responds to pressure from all directions and does not cause a malfunction at a bent portion. Was.

[0026]

As described above in detail, according to the present invention, the outer conductor is formed on the periphery of the inner conductor via the spacer functioning as a space insulation holding means, and the outer periphery thereof is simply coated with an insulating coating. Although it is a simple configuration, it is possible to reliably perform on / off operation in response to pressure from all directions, and to provide a highly reliable cord-shaped pressure-sensitive switch that does not cause malfunction at the bent part. Obtainable. Accordingly, there is no restriction on the wiring pattern, and the wiring pattern can be widely used in various applications.

In particular, when a conductor material is coated on the periphery of the elastic core as the internal conductor, the spacer bites into the elastic core even if pressure is applied immediately above the spacer,
Since the inner conductor and the outer conductor come into electrical contact with each other in the area where pressure is applied, the sensitivity to pressure can be further increased, and high resilience to deformation due to pressure is maintained. can do.

Further, the cord-shaped pressure-sensitive switch has a very simple structure as described above, and also has a conventional manufacturing method such as extrusion molding, longitudinal attachment, horizontal winding or braiding in the manufacturing process. Can be employed, so that it can be manufactured with excellent productivity. Therefore, the manufacturing cost can be remarkably reduced as compared with the conventionally proposed cord-shaped pressure-sensitive switch.

[Brief description of the drawings]

FIG. 1 is a view showing a first embodiment of the present invention, and is a partially cutaway perspective view of a cord-shaped pressure-sensitive switch.

FIG. 2 is a sectional view of a cord-shaped pressure-sensitive switch according to the first embodiment of the present invention.

FIG. 3 is a view showing a second embodiment of the present invention and is a partially cutaway perspective view of a cord-shaped pressure-sensitive switch.

FIG. 4 is a view showing a third embodiment of the present invention and is a partially cutaway perspective view of a cord-shaped pressure-sensitive switch.

FIG. 5 is a sectional view of a cord-shaped pressure-sensitive switch according to a third embodiment of the present invention.

FIG. 6 is a view showing a fourth embodiment and a fifth embodiment of the present invention, and is a partially cutaway perspective view of a cord-shaped pressure-sensitive switch.

FIG. 7 is a perspective view of a braided wire constituting an inner conductor of a cord-shaped pressure-sensitive switch according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal conductor 1a Elastic core 1b Conductor material 1c Glass fiber 1d Tin-plated soft copper wire 2 Spacer 3 External conductor 4 Insulation coating

Claims (1)

[Claims] 1. On a circumference of an inner conductor continuous in a longitudinal direction,
A cord-shaped pressure-sensitive switch in which a spacer made of an insulating material, an outer conductor, and an insulating coating are sequentially formed, and when no pressure is applied from the outside, the inner conductor and the outer conductor are spatially insulated by the spacer. A cord-shaped pressure-sensitive switch characterized in that when pressure is applied from above, the outer conductor makes electrical contact with the inner conductor and becomes conductive.