JP3473530B2 - Pressure sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensor for detecting pressure (including load).

[0002]

2. Description of the Related Art A conventional general pressure sensor has a structure in which positive and negative electrode plates sandwich a pressure-sensitive conductive member made of an elastic material such as rubber mixed with a conductive material. In this pressure sensor, the pressure application is detected by detecting a decrease in the resistance value of the pressure-sensitive conductive member caused by the pressure-sensitive conductive member being elastically deformed so as to be crushed.

[0003]

However, in the above-mentioned pressure sensor, it may be difficult to detect the pressure sensitively because the sensitivity of the pressure-sensitive conductive member is low.

Therefore, an object of the present invention is to provide a pressure sensor having a relatively simple structure and capable of detecting pressure with high sensitivity.

[0005]

Technical means for achieving the object, according to an aspect of the elastic conductive tube tubular circumferential direction of the whole section is in the conductive portion having conductivity, the elastic electric
Provided in the electric tube,
An elongated composite member that is allowed to rotate,
The composite member is formed at both end portions of the composite member in a sectional view.
The side end insulator part and the central part of the cross-sectional view of the composite member
The central insulator part to be arranged, and the side end insulator part on one side
Between the central insulator part and the side end insulator on the other side
Section and the central insulator section, respectively, and
A first electrode member that is spaced apart from and provided along the longitudinal direction
And a second electrode member, wherein the first electrode member and the second electrode member are at least a partial section in the circumferential direction of a flexible elongated metal conductor and the outer peripheral portion of the metal conductor. And an elastic conductive member provided along the longitudinal direction of the metal conductor so as to cover the elastic conductor, and the elastic conductive tube is arranged apart from the conductive portion of the elastic conductive tube in a natural state, while the elastic When the conductive tubes are elastically deformed by a pressing force from the outside, the conductive tubes are arranged so that they can be electrically connected to each other via the conductive portions of the elastic conductive tubes.

The technical means for achieving the above-mentioned object is a tubular tube body made of an elastic material.
And a flexible elongated metal conductor and an elastic conductive member provided along the longitudinal direction of the metal conductor so as to cover at least a part of the outer peripheral portion of the metal conductor in the circumferential direction. A first electrode member and a second electrode member, the tube body, while holding the first electrode member and the second electrode member in a separated state,
When a pressing force is applied in a direction to bring the first electrode member and the second electrode member close to each other, the first electrode member and the second electrode member are elastically deformed to allow the first electrode member and the second electrode member to come into contact with each other, and
The one electrode member and the second electrode member are the tube body.
Provided at a predetermined interval in the vertical direction within the internal space of
Before the elastic conductive member in the first electrode member
The surface facing the second electrode member is recessed upward in a V shape in cross section.
And the elasticity of the second electrode member
The surface of the conductive member facing the first electrode member is the first electrode.
Cut the section so that it is parallel to the member with a uniform gap.
It is characterized by protruding upward in a letter shape .

Further, preferably, the metal conductor is a twisted wire formed by twisting a plurality of metal wires, or a flexible core material and a metal wire spirally wound around the outer circumference of the core material. And a winding with

Further, the technical means for achieving the above-mentioned object is a tubular elastic conductive tube in which a whole circumferential section is a conductive portion having conductivity, and the elastic conductive tube.
Provided inside, allowing rotation within the elastic conductive tube
And a composite member having an elongated shape,
The material is a side end formed on both ends of the composite member in cross section.
The insulator part and the central part of the cross-sectional view of the composite member are arranged.
The central insulator part, the side end insulator part on one side, and the central insulator part.
Between the edge body portion and the side end insulator portion on the other side and the middle
It is formed between the central insulator part and
The first electrode member and the second electrode provided along the longitudinal direction.
An electrode member, wherein the first electrode member and the second electrode member are elongated metal conductors and the metal conductor of the metal conductor so as to cover at least a part of the circumferential direction of the outer peripheral portion of the metal conductor. Elastic conductive members provided along the longitudinal direction, respectively, are arranged apart from the conductive portion of the elastic conductive tube in the natural state of the elastic conductive tube, while the elastic conductive tube is pressed from the outside. Are arranged so that they can be electrically connected to each other via the conductive portion of the elastic conductive tube when elastically deformed by the electrode of at least one of the first electrode member and the second electrode member. The metal conductor of the member is a metal resistance conductor having a predetermined resistance value per unit length.

Furthermore, the technical means for achieving the above-mentioned object is a tubular tube body formed of an elastic material.
And an elastic conductive member provided along the longitudinal direction of the metal conductor so as to cover at least a part of the outer peripheral portion of the metal conductor in the circumferential direction, and a first electrode member, and a second electrode member includes a front
The tube body holds the first electrode member and the second electrode member in a separated state, while pressing force is applied in a direction in which the first electrode member and the second electrode member are brought close to each other. Permitting contact between the first electrode member and the second electrode member, and the first electrode member and the second electrode member.
The pole members are the upper and lower parts in the inner space of the tube body.
Is provided at a predetermined interval in the direction of the first electrode member.
The surface of the elastic conductive member facing the second electrode member is
It has a generally V-shaped cross section and is recessed upward,
The first electrode member of the elastic conductive member in the electrode member
The surface facing to is evenly spaced from the first electrode member.
The metal conductor of at least one electrode member of the first electrode member and the second electrode member protrudes upward in a substantially V-shaped cross section so as to form a line, and has a predetermined resistance value per unit length. It is a metal resistance conductor having.

Preferably, the metal resistance conductor is
It may be a metal resistance wire, or a resistance winding provided with a flexible core material and a metal resistance wire spirally wound around the core material.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION <First Embodiment> FIG. 1 is a cutaway perspective view of a pressure sensor 10 according to a first embodiment of the present invention. As shown in FIG. 1, the pressure sensor 10 includes a hollow tube-shaped elastic conductive tube 21 and positive and negative first and second electrode members 22 and 23 that are loosely inserted in the elastic conductive tube 21. And an elongated composite member 24 having elasticity.

As shown in FIG. 1, the elastic conductive tube 21 is a substantially circular tube-shaped tube body having a hollow portion 28, and is entirely made of a conductive elastic material such as conductive rubber. Here, the whole is a conductive part.

As shown in FIG. 1, the composite member 24 includes side end insulator portions 31 and 32 formed at both end portions in a sectional view, a central insulator portion 33 arranged in a central portion in a sectional view, and one side portion. The first electrode member 22 formed between the end insulator part 31 and the central insulator part 33, and the second electrode formed between the side end insulator part 32 on the other side and the central insulator part 33. And a member 23.

Each of the electrode members 22 and 23 is a flexible elongated metal conductor 22a and 23a, and the metal conductor 2 thereof.
2a, 23a, and elastic conductive members 22b, 23b provided along the longitudinal direction of the metal conductors 22a, 23a so as to cover at least a part of the outer peripheral portion in the circumferential direction (here, upper and lower sections). ing.

The elastic conductive members 22b and 23b are integrally formed with each of the insulator parts 31 to 33 by extrusion molding using an elastic material having conductivity such as conductive rubber similar to the elastic conductive tube 21. In order to ensure sufficient flexibility, the metal conductors 22a and 23a are twisted wires formed by twisting a plurality of metal wires, or, as shown in FIG. 2, with a flexible elongated core material 100. The core member 100 is formed by a winding wire provided with a metal wire 101 spirally wound around the outer circumference thereof. Here, the core material 100 of the winding of FIG. 2 is formed, for example, by extruding and covering a rubber material on the outer periphery of a cord-shaped tensile strength wire. Further, the wire diameter of the winding in FIG.
8 mm, and the metal wire 101 has, for example, a wire diameter of 50 μm.
Copper wire or Nichrome wire, etc. is used.

The electrode members 22 and 23 having the above structure are
Elastic conductive members 22b and 23 are provided on the metal conductors 22a and 23a.
b by extrusion coating together with the respective insulator parts 31 to 33, or the elastic conductive member 22b, which has been previously formed,
23b and a predetermined portion in each of the insulator parts 31 to 33 are provided with internal cavities in the longitudinal direction, and the metal conductors 22 and 33 are inserted into the internal cavities.

With such a structure, when pressure is applied from above the composite member 24 in the thickness direction of FIG. 1 (the direction Dr1 in FIG. 3), the elastic conductive tube 21 and the composite member 24 are separated from each other as shown in FIG. As a result, the first electrode member 22 and the elastic conductive tube 21 come into contact with each other, and the second electrode member 23 and the elastic conductive tube 21 come into contact with each other, so that the first electrode member 22 and the second electrode member 23 respectively. And are electrically connected through the elastic conductive tube 21. Of course, when the shape of the elastic conductive tube 21 returns to the circular shape which is the natural state, the shape of the composite member 24 is elastically restored to its original state.

The composite member 24 is composed of the elastic conductive tube 2
Although the rotation within 1 is allowed, as shown in FIG. 4, for example, the composite member 24 has a hollow portion 28 of the elastic conductive tube 21.
4, when a pressing force is applied from above the elastic conductive tube 21 (the direction Dr2 in FIG. 4) in a diagonal posture from the upper left to the lower right, the direction indicated by the arrow in FIG. R1 (counterclockwise) is easily rotated, and eventually the state shown in FIG. 3 is reached, and the first electrode member 22 and the second electrode member 2 are rotated.
3 is electrically connected to the elastic conductive tube 21.

As a result, signal lines (not shown) for signal extraction are connected at the ends of both electrode members 22, 23, for example, and the first electrode member 22 is connected through the signal lines.
The presence or absence of pressure application can be detected by detecting the presence or absence of electrical conduction between the second electrode member 23 and the second electrode member 23.

As described above, according to this embodiment, since the elastic conductive tube 21 is hollow, it is relatively easily elastically deformed, and the elastic conductive tube 21 is elastically deformed. Since the pressure is detected by detecting the presence or absence of conduction between the first electrode member 22 and the second electrode member 23 that occurs, the pressure sensor can detect the pressure with high sensitivity with a relatively simple configuration. The first effect that 10 can be provided is obtained.

By the way, conductive rubber or the like is generally used as the elastic conductive members 22b and 23b.
Since the resistance value changes due to deformation (elongation) due to external pressure,
When the first electrode member 22 and the second electrode member 23 are composed of only the elastic conductive members 22b and 23b, both electrode members 22 and
The resistance value of 23 may become unstable, and the electrical characteristics of the pressure sensor 10 may become unstable.

On the other hand, in this embodiment, the first electrode member 22 and the second electrode member 23 are composed of flexible elongated metal conductors 22a, 23a and the metal conductors 22a, 22a.
Since the elastic conductors 22b and 23b are provided along the longitudinal direction of the metal conductors 23a and 23a so as to cover at least a part of the circumferential direction of 23a, the metal conductors 22a and 23a prevent Electrode member 22,
The resistance value of 23 is stabilized, and the second effect that the electrical characteristics of the pressure sensor 10 can be stabilized is obtained.

Further, since flexible metal conductors 22a and 23a are used for the first electrode member 22 and the second electrode member 23, the first electrode member 22 and the second electrode member are formed by the metal conductors 22a and 23a. 23 and the flexibility of the pressure sensor 10 is not impaired, and the pressure sensor 1
The flexibility of 0 can be sufficiently ensured, and as a result, the pressure sensor 10 can be flexibly deformed and responded to the application of the pressing force, and the pressure sensor 10 can be freely arranged by allowing the curved arrangement and the like. The third effect is that the degree can be expanded.

Further, the metal conductor 2 is provided on both electrode members 22 and 23.
Since 2a and 23a are used, the metal conductors 22a and
The fourth effect that the two electrode members 23, 23 and the signal line for signal extraction can be easily and firmly connected by a simple connection method such as solder connection or crimp connection using 23a is obtained. To be

Furthermore, since the metal conductors 22a and 23a provided in the first electrode member 22 and the second electrode member 23 are formed by twisted wires or by the winding wire of FIG. 2, the flexibility of the pressure sensor 10 is improved. It can be further improved.

<Second Embodiment> In the pressure sensor 10 according to the second embodiment of the present invention, in the pressure sensor 10 according to the first embodiment described above, the metal conductors 22a, 23a of the electrode members 22, 23 are It is composed of the metal resistance conductors 22a and 23a having a predetermined resistance value per unit length, and the other structure is the same as that of the first embodiment.

The metal resistance conductors 22a, 2 according to the present embodiment
More specifically, 3a is composed of a metal resistance wire such as a nichrome wire, or a metal resistance wire such as a nichrome wire instead of the metal wire 101 in the winding shown in FIG. Here, the resistance value per unit length of the metal resistance conductors 22a and 23a is set to, for example, 1 Ω / m to 40 kΩ / m. When the metal resistance conductors 22a and 23a are composed of windings, there is an advantage that the flexibility of the electrode members 22 and 23 and the pressure sensor 10 can be improved.

FIG. 5 is an equivalent circuit diagram showing an example of the connection relationship between the pressure sensor 10 and the detection circuit section 41 connected to the pressure sensor 10 when no pressure is applied.
Here, one end of the first electrode member 22 of the pressure sensor 10 is connected to the connection terminal 38, the lead wire 37a, and the pull-down resistor R.
_It is connected to the positive electrode side of the power source E through _O , and one end of the second electrode member 23 is connected to the negative electrode side of the power source E through the connection terminal 39 and the lead wire 37b. The other ends of both electrode members 22 and 23 are connected to each other via a terminating resistor 42. Then, in the detection circuit unit 41, the partial voltage applied to the pull-down resistor R _O (V1 in FIG. 5, V in FIG. 7).
2) is detected. Here, although in order to detect a partial pressure applied to the pull-down resistor R _O, may be detected an intermediate voltage between the pull-down resistor R _O and the connection terminal 39.

Here, when no pressure is applied as shown in FIG. 1 etc., the first electrode members 22 and 23 of the composite member 24 are
Are separated from the elastic conductive tube 21. Therefore, in this case, both electrode members 22 and 23 and the detection circuit unit 4
The circuit composed of 1 and the terminating resistor 42 is as shown in FIG. Here, the length of each electrode member 22 and 23 as a conductive path in the pressure sensor 10 is L, and the electric resistance per unit length of the conductive path (electrode members 22 and 23) is r.
_{When D} and the resistance value of the terminating resistor 42 are R _L , the input resistance R1 seen from the detection circuit unit 41 constituted by both electrode members 22 and 23 and the terminating resistor 42 is R1 = 2r _D L + R _L ... (1) Therefore, the detection voltage level V1 in the detection circuit unit 41 is expressed by the following equation (2).

V1 = R _O E / (2r _D L + R _L + R _O ) (2) Here, in the present embodiment, both electrode members 22 and 23 have a metal resistance conductor 22a having a predetermined resistance value per unit length. ，
Since 23a is used, the resistance value per unit length of both electrode members 22 and 23 can be made uniform.

It is assumed here that R _L > r _D L (3) R _O <R _L (4).

On the other hand, as shown in FIG. 6, the pressure sensor 10
When pressure is applied at the position of point X, the elastic conductive tube 21 bends and contacts the first electrode member 22 and the second electrode member 23 at this point X as shown in FIG. If the resistance value of the elastic conductive tube 21 in this case is R _D and the distance from the connection side end of the lead wire 37 of the pressure sensor 10 in FIG. 6 to the point X is x, both electrode members 22, 23,
The circuit composed of the detection circuit unit 41 and the termination resistor 42 is as shown in FIG. 7, and the input resistance R2 viewed from the detection circuit unit 41 is substantially R2 = 2r _D x + R _D (5) Become. However, in the equation (5), it is assumed that R _L >> R _D (6) is set, and thus the resistance value of the terminating resistor 42 is approximately infinite (broken wire). ).

[0033] This equation (5), the output voltage V2 is output to the detection circuit section 41, and _{V2 = R O E / (2r} D x + R D + R O) ... (7). Here, the distance x from the end of the pressure sensor 10 in FIG. 6 to the point X changes variously between 0 and L as the pressure application point changes, so the output voltage V2 becomes
Distance according to a change in x, which varies from _{V2 = R O E / (R} D + R O) ... (8) to _{V2 = R O E / (2r} D L + R D + R O) ... (9). However, (7) to (9) any type, it becomes a large value R _L is much more R _D as in (2) no component of R _L differ from the formula, and (6) Since a large output change is obtained between V1 (equation (2)) and V2 (equations (7) to (9)), it is possible to reliably detect the presence or absence of pressure application. The distance x (that is, the position of the pressure application point) can be detected based on the magnitude of the output voltage V2 when pressure is applied.

The terminating resistor 42 ( _RL ) connecting the ends of the two conductive paths composed of the electrode members 22 and 23 has a function of detecting a failure in the disconnection of the conductive paths, and is applied with a predetermined voltage. By detecting the voltage drop in the terminating resistor 42 in the case of being applied, the presence / absence of energization can be easily detected even when no pressure is applied, and the fact that the wire is broken can be easily detected especially when there is no energization. Is. However, as a result of using the conductive elastic body for the conductive path, the reliability against disconnection becomes extremely high. Therefore, if the failure detection function for disconnection is not required, the terminating resistor 42 can be omitted.

When the pressure application to the pressure sensor 10 is released, the elastic conductive tube 21 and the composite member 2 are released.
Since the elastic restoring force of 4 restores the original state as shown in FIG. 1 and the like, the contact of the conductive path is easily switched from on to off.

As described above, according to this embodiment, the above-mentioned first, second and fourth effects are obtained as in the first embodiment, and at any position in the longitudinal direction of the pressure sensor 10. The fifth effect is obtained in that it is possible to detect whether or not pressure is applied.

In this embodiment, both electrode members 22,
Although the metal conductors 22a and 23a of 23 are constituted by the metal resistance conductors 22a and 23a having a predetermined resistance value per unit length, the metal conductor 22 of either one of the electrode members 22 and 23 is formed.
Only a and 23a are constituted by the metal resistance conductors 22a and 23a, and the metal conductors 22a and 2 of the other electrode member 22 and 23 are formed.
3a may be composed of a general metal wire such as a copper wire or the flexible metal conductors 22a and 23a according to the first embodiment.

<Modification> FIGS. 8 and 9 are sectional views showing modifications of the pressure sensor 10 according to the first and second embodiments described above. In the pressure sensor 10 of FIGS. 8 and 9, when the pressure is applied, the first electrode member 22 and the second electrode member 23 come into direct contact with each other to be electrically connected. The presence / absence of pressure application can be detected by detecting the presence / absence of conduction between the two electrode members 22 and 23, and at least one of the metal conductors 22a, 22a, 23a
When a metal resistance conductor having a predetermined resistance value per unit length is used in the above, as in the case of the second embodiment, it is formed by both electrode members 22 and 23 via the pressure application point when pressure is applied. It is possible to detect which position in the longitudinal direction of the pressure sensor 10 the pressure is applied by using the change in the resistance value of the closed circuit.

More specifically, the pressure sensor 10 of FIG.
A tubular (circular tubular in this case) tube body (elastic holding member) 51 formed of an elastic material such as rubber, and a first body provided in the tube body 51 along the longitudinal direction of the tube body 51 so as to be separated from each other. It is configured to include an electrode member 22 and a second electrode member 23.

The electrode members 22 and 23 are the same as the metal electrodes 22a and 23a according to the first or second embodiment, and the metal electrodes 22 and 23a.
elastic conductive members 22b, 2 made of conductive rubber or the like provided so as to cover the outer peripheral portions of a, 23a and fill the inner cavity of the tube body 51 leaving a gap 52.
3b and. Both electrode members 22 and 23 are
In the internal space of the tube body 51, a predetermined interval (here, the gap 52) in the pressure application direction (here, the vertical direction).
It is opened.

When pressure is applied, the tube body 51 and the electrode members 22 and 23 are elastically deformed so as to be crushed, so that the electrode members 22 and 23 come into contact with each other so that they are electrically connected to each other. It has become.

Here, in the pressure sensor 10 of FIG. 8, the second electrode member 23 of the elastic conductive member 22b of the first electrode member 22 is used.
And a facing surface 53 of the elastic conductive member 23b of the second electrode member 23 facing the first electrode member 22 forms a uniform gap 52 with the facing surface 53. It projects upward in a substantially V-shaped cross-section so that it is open and parallel to each other (so as to mesh with each other). For this reason,
In this modification, both electrode members 22 and 23 are surely brought into contact with each other even if pressure is applied from an oblique direction inclined with respect to the vertical direction.

On the other hand, in the pressure sensor 10 of FIG.
The elastic conductive members 22b and 23b of the two electrode members 22 and 23 have a shape for a circular tube surrounding the metal conductors 22a and 23a, and the two electrode members 22 and 23 have the tube body 51.
Are provided at upper and lower ends of the internal cavity 55 at predetermined intervals. In addition, the tube body 51
It has a cross-sectional shape in which the vertical height is slightly larger than the lateral width. Further, a mounting portion 51a having a flat bottom surface is provided on the lower side surface portion of the tube body 51 so that the mounting portion 51a can be fixed (or locked) to, for example, the inner peripheral portion of an automobile door. Has become.

In each of the above-mentioned embodiments, the entire elastic conductive tube 21 is used as the conductive portion, but only a part of the circumferential direction may be used as the conductive portion. In this case, both electrode members 2
2 and 23 must be provided at positions that can contact the conductive portion of the elastic conductive tube 21.
It is preferred that the composite member 24 not rotate therein.

[0045]

According to the first and third aspects of the invention, since the elastic conductive tube is hollow, it is relatively easily elastically deformed. Whether or not the elastic conductive tube is elastically deformed. Since the pressure is detected by detecting the presence or absence of conduction between the first electrode member and the second electrode member, which is accompanied with the above, it is possible to detect the pressure with high sensitivity with a relatively simple structure. The first effect is that a sensor can be provided.

By the way, as the elastic conductive member, conductive rubber or the like is generally used. However, since the resistance value of such an elastic conductive member changes due to deformation (elongation) due to temperature, humidity and external pressure, the elastic conductive member is elastically conductive. If the first electrode member and the second electrode member are composed of only members, the resistance values of both electrode members may become unstable, and the electrical characteristics of the pressure sensor may become unstable.

On the other hand, in the present invention, the first electrode member and the second electrode member cover at least a part of the circumferential direction of the metal conductor having a flexible elongated shape and the outer periphery of the metal conductor. As described above, since the elastic conductor is provided along the longitudinal direction of the metal conductor, the resistance value of both electrode members is stabilized by the metal conductor, and the electrical characteristics of the pressure sensor are stabilized. The second effect that can be realized is obtained.

Further, since the flexible metal conductor is used for the first electrode member and the second electrode member, the flexibility of the first electrode member, the second electrode member, and the pressure sensor is hindered by the metal conductor. As a result, the flexibility of the pressure sensor can be sufficiently ensured, and as a result, the pressure sensor can be flexibly deformed and responded to the pressing force application, and the pressure can be changed by allowing the curved arrangement and the like. The third effect that the degree of freedom in arranging the sensor can be expanded is obtained.

Further, since the metal conductors are used for both electrode members, the metal conductors are used to connect the electrode members and the signal line for signal extraction by a simple connecting method such as solder connection or pressure bonding connection. It is possible to obtain the fourth effect that can be performed easily and firmly.

Also in the second and third aspects of the invention, the presence or absence of pressure application is detected by detecting the presence or absence of electrical conduction between the first electrode member and the second electrode member caused by elastic deformation of the elastic holding member. Therefore, the first effect described above can be obtained.

Also in the present invention, since the first electrode member and the second electrode member are provided with the metal conductor, the above-mentioned second and fourth effects can be obtained.

Further, also in the present invention, since the metal conductors provided in the first electrode member and the second electrode member have flexibility, the third effect described above can be obtained.

According to the third aspect of the invention, the metal conductor provided in the first electrode member and the second electrode member is a twisted wire formed by twisting a plurality of metal wires, or is flexible. Since the winding includes the core material and the metal wire spirally wound around the core material, the flexibility of the pressure sensor can be further improved.

According to the invention described in claims 4 and 6,
Since the presence or absence of pressure application can be detected by detecting the presence or absence of electrical conduction between the first electrode member and the second electrode member via the conductive portion of the elastic conductive tube, the above-mentioned first effect is obtained. To be

Also in the present invention, since the first electrode member and the second electrode member are provided with the metal conductor, the above-mentioned second and fourth effects can be obtained.

The metal conductor of at least one of the first electrode member and the second electrode member is a metal resistance conductor having a predetermined resistance value per unit length. The resistance value per unit length of at least one of the electrode members can be made uniform. Thereby, by connecting the signal line for signal extraction to the end portions of the first electrode member and the second electrode member, the first electrode member and the second electrode member at any position in the longitudinal direction by applying pressure. Since the resistance value between the ends of both electrode members when viewed from the signal line side when conducting through the conductive portion of the elastic conductive tube changes according to the position where the pressing force is applied, both electrode members are applied when pressure is applied. By detecting the magnitude of the flowing current and the like, it is possible to obtain the fifth effect that it is possible to detect at which position in the longitudinal direction of the pressure sensor the pressure is applied.

Also in the fifth and sixth aspects of the invention, the presence or absence of pressure application is detected by detecting the presence or absence of electrical continuity between the first electrode member and the second electrode member via the conductive portion of the elastic conductive tube. Since it can be detected, the first effect described above can be obtained.

Also in the present invention, since the first electrode member and the second electrode member are provided with the metal conductor, the above-mentioned second and fourth effects can be obtained.

Also in the present invention, the metal conductor of at least one of the first electrode member and the second electrode member is a metal resistance conductor having a predetermined resistance value per unit length. Therefore, the resistance value per unit length of at least one of the electrode members can be made uniform, and as a result, the fifth effect described above can be obtained.

[Brief description of drawings]

FIG. 1 is a cutaway perspective view of a pressure sensor according to a first embodiment of the present invention.

FIG. 2 is a diagram showing windings used in the pressure sensor of FIG.

FIG. 3 is a cross-sectional view showing a state of the pressure sensor of FIG. 1 when pressure is applied.

4 is a cross-sectional view of the pressure sensor of FIG.

FIG. 5 is an equivalent circuit diagram showing an example of a connection relationship between a pressure sensor according to a second embodiment of the present invention and a detection circuit unit connected to the pressure sensor when no pressure is applied.

FIG. 6 is a diagram showing a pressure application position when pressure is applied to a pressure sensor.

7 is a diagram showing a state in which pressure is applied in the circuit diagram of FIG.

FIG. 8 is a cross-sectional view of a modified example of the pressure sensor according to the first embodiment and the second embodiment.

FIG. 9 is a cross-sectional view of a modified example of the pressure sensor according to the first embodiment and the second embodiment.

[Explanation of symbols]

10 Pressure sensor 21 Elastic conductive tube 22, 23 First electrode member, second electrode member 22a, 23a metal conductor 22b, 23b Elastic conductive member 24 Composite member 31, 32 Side end insulator part 33 Central insulator 41 Detection circuit section 42 Termination resistor 100 heartwood 101 metal wire

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI H01H 13/16 H01H 13/16 Z (58) Fields investigated (Int.Cl. ⁷ , DB name) G01L 9/00 G01L 1 / 20 H01H 13/52 H01H 35/00 B60J 5/00 H01H 13/16

Claims (6)

(57) [Claims] 1. A tubular elastic conductive tube having an electrically conductive portion in the entire circumferential direction, and an elastic conductive tube provided in the elastic conductive tube.
Elongate composite member that is allowed to rotate in the tube
And the composite member , wherein the composite member is a side end insulator formed at both end portions in cross section of the composite member.
And a central insulator part arranged in the central part of the cross-sectional view of the composite member
And between the side end insulator portion on one side and the central insulator portion,
And between the side end insulator portion and the central insulator portion on the other side
Are formed on each side and are separated from each other along the longitudinal direction.
A first electrode member and a second electrode member that are provided as a member , wherein the first electrode member and the second electrode member are provided with a flexible elongated metal conductor and an outer peripheral portion of the metal conductor. An elastic conductive member provided along the longitudinal direction of the metal conductor so as to cover at least a part of the circumferential direction, and separated from the conductive portion of the elastic conductive tube in a natural state of the elastic conductive tube. While being placed,
A pressure sensor, wherein when the elastic conductive tube is elastically deformed by a pressing force from the outside, the elastic conductive tube is arranged so as to be electrically connectable to each other via the conductive portion of the elastic conductive tube. 2. A tubular tutu formed of an elastic material.
A flexible body, an elongated metal conductor having flexibility, and an elastic conductive member provided along the longitudinal direction of the metal conductor so as to cover at least a part of the outer periphery of the metal conductor in the circumferential direction. A first electrode member and a second electrode member respectively provided with, the tube body, while holding the first electrode member and the second electrode member in a separated state, the first electrode member and the When the pressing force is applied in a direction to close the second electrode member to each other by elastic deformation to allow the contact between the second electrode member and the first electrode member, the first electrode member and the second The electrode member is
A predetermined space in the vertical direction within the inner space of the tube
And the elastic conductive portion in the first electrode member.
The surface of the material facing the second electrode member has a substantially V-shaped cross section.
Is recessed toward the front of the second electrode member
The surface of the elastic conductive member facing the first electrode member is the first electrode member.
Cross-section parallel to one electrode member with a uniform gap
A pressure sensor characterized by protruding upward in a V shape . 3. The metal conductor is a twisted wire formed by twisting a plurality of metal wires, or comprises a flexible core material and a metal wire spirally wound around the outer circumference of the core material. The pressure sensor according to claim 1, wherein the pressure sensor is a winding. 4. A tubular elastic conductive tube having an electrically conductive portion in the entire circumferential direction, and an elastic conductive tube provided in the elastic conductive tube.
Elongate composite member that is allowed to rotate in the tube
And the composite member , wherein the composite member is a side end insulator formed at both end portions in cross section of the composite member.
And a central insulator part arranged in the central part of the cross-sectional view of the composite member
And between the side end insulator portion on one side and the central insulator portion,
And between the side end insulator portion and the central insulator portion on the other side
Are formed on each side and are separated from each other along the longitudinal direction.
A first electrode member and a second electrode member that are provided as a member , wherein the first electrode member and the second electrode member are at least one in the circumferential direction of an elongated metal conductor and an outer peripheral portion of the metal conductor. An elastic conductive member provided along the longitudinal direction of the metal conductor so as to cover a section of the elastic conductive tube, and the elastic conductive tube is arranged apart from the conductive portion of the elastic conductive tube in a natural state. , The elastic conductive tube is arranged so as to be electrically connectable to each other via the conductive portion of the elastic conductive tube when elastically deformed by a pressing force from the outside, the first electrode member and the second The pressure sensor, wherein the metal conductor of at least one of the electrode members is a metal resistance conductor having a predetermined resistance value per unit length. 5. A tubular tutu formed of an elastic material.
A first body, an elongated metal conductor, and an elastic conductive member provided along the longitudinal direction of the metal conductor so as to cover at least a part of the outer periphery of the metal conductor in the circumferential direction. An electrode member and a second electrode member are provided, and the tube body holds the first electrode member and the second electrode member in a separated state, while the first electrode member and the second electrode member are provided. When a pressing force is applied in a direction to bring the first electrode member and the second electrode member into contact with each other, the first electrode member and the second electrode member are allowed to come into contact with each other, and the first electrode member and the second electrode member are
A predetermined space in the vertical direction within the inner space of the tube
And the elastic conductive portion in the first electrode member.
The surface of the material facing the second electrode member has a substantially V-shaped cross section.
Is recessed toward the front of the second electrode member
The surface of the elastic conductive member facing the first electrode member is the first electrode member.
Cross-section parallel to one electrode member with a uniform gap
The metal conductor of the electrode member of at least one of the first electrode member and the second electrode member protruding upward in a generally V shape is a metal resistance conductor having a predetermined resistance value per unit length. A pressure sensor characterized by being present. 6. The metal resistance conductor is a metal resistance wire or a resistance winding provided with a flexible core material and a metal resistance wire spirally wound around the outer circumference of the core material. The pressure sensor according to claim 4, wherein the pressure sensor is a pressure sensor.