JP2002286561A - Load sensor, pinch detection device and load detection device - Google Patents

Abstract

[PROBLEMS] To provide a load sensor that has a simple structure, can be manufactured easily and at low cost, and functions properly even if it is bent and arranged with a large curvature, and can reduce the impedance of the load sensor. And a pinch detection device and a load detection device using the same. A load sensor includes an elastic conductive tube, first and second electrode members, and an insulated linear member wound around the first electrode member.
5 is provided. The insulated linear member 15 allows electrical contact between the electrode members 12 and 13 or between the electrode member 12 and the elastic conductive tube 11 when a load is applied, and allows the direct or elastic conductive tube between the electrode members 12 and 13. In addition, when no load is applied, the gap is maintained in an insulated state. The electrode members 12 and 13 are configured by spirally winding a conductive metal wire around the outer periphery of an elongated central member having elasticity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load sensor, a pinch detection device, and a load detection device.

[0002]

2. Description of the Related Art A conventional load sensor is disclosed in
Japanese Patent Application Laid-Open No. 281906/1990. In this load sensor, as shown in FIG. 16, a void 1a extending in the longitudinal direction is formed inside an elongated elastic insulator 1 and a plurality of circumferentially spaced air gaps are formed within the thickness of the elastic insulator 1. Electrode wire 3A ~
3D is embedded and formed. Multiple electrode wires 3A
3D are embedded so as to be helically twisted around the gap 1a, and one section of the outer peripheral surface in the circumferential direction is exposed in the gap 1a. Then, when the elastic insulator 1 is elastically deformed by the application of the load so that the gap 1a is crushed, the electrode wires 3A to 3D come into contact with each other to conduct, and the load is detected.

[0003] As a method of manufacturing this load sensor, a spacer having the same shape as the air gap 1a and a plurality of electrode wires 3A to 3D are twisted to form a stranded wire, and the stranded wire is coated with the elastic insulator 1. A method has been proposed in which a spacer is formed by extracting a spacer.

[0004]

However, the above-described conventional load sensor requires a complicated manufacturing process of twisting the spacer with the electrode wires 3A to 3D and subsequently extracting the spacer due to its structure. However, there is a problem that the cost is high.

[0005] Further, since there is no means provided for positively separating and insulating the electrode wires 3A to 3D, the bent portions of the electrode wires 3A are used when the load sensor is bent.
There is also a problem that 3D may erroneously come into contact and erroneous detection may occur.

In view of the above problems, the first aspect of the present invention
An object of the present invention is to provide a load sensor which has a simple structure, can be manufactured easily and at low cost, and can function properly even if it is bent and arranged with a large curvature, a pinch detecting device and a load detecting device using the same. It is to provide.

Further, a second object of the present invention is to provide a load sensor capable of reducing the impedance of the load sensor and expanding the degree of freedom in designing a circuit configuration such as a detection circuit connected to the load sensor. An object of the present invention is to provide a sandwich detection device and a load detection device that are used.

[0008]

Technical means for achieving the above object are an elastic tube formed of an elastic material, and a metal conductive member having an elongated shape and connected to at least the outer peripheral portion in a longitudinal direction. And a first and a second inserted in the elastic tube so as to be parallel to each other.
The first electrode member and the second electrode member are provided on the outer periphery of at least one of the first electrode member and the second electrode member. An insulating member that allows electrical contact with the second electrode member, and separates and electrically insulates the first electrode member and the second electrode member when no load is applied; A load is detected based on a state of electrical conduction between the first electrode member and the second electrode member.

Further, the technical means for achieving the above object includes an elastic tube formed of an elastic material, at least a part of which in the circumferential direction is a conductive portion having elasticity, and an elongated tube. A first and second metal conductive member is provided at least on the outer peripheral portion and is connected in the longitudinal direction so as to be parallel to each other.
The first electrode member and the second electrode member are provided on the outer periphery of at least one of the first electrode member and the second electrode member. A direct electrical contact between said second electrode member,
Alternatively, while permitting the at least one of the electrode members to make electrical contact with the conductive portion of the elastic tube, when no load is applied, between the first electrode member and the second electrode member and at least one of the two. An insulating member that electrically insulates between the one electrode member and the conductive portion of the elastic tube; and a direct electrical connection between the first electrode member and the second electrode member. The load is detected based on a conduction state or an electric conduction state of the elastic tube via the conductive portion.

Further, preferably, the insulating member has an elongated shape having an insulating property at least at an outer peripheral portion thereof,
It is preferable that the insulating member is an insulated linear member spirally wound around an outer peripheral portion of at least one of the first electrode member and the second electrode member at a predetermined winding interval.

[0011] Preferably, the insulated linear member comprises:
It is preferable to include a first metal wire and an insulating coating layer formed by being applied to the surface of the first metal wire.

More preferably, the insulated wire member includes a first metal wire and a resin coating formed by extruding an insulating resin on the surface of the first metal wire. .

Preferably, the insulated linear member comprises:
It is preferably a string-like member or a fiber-like member formed of an insulating material.

Still preferably, the insulating member is made of an insulating material, and is provided so as to cover an outer peripheral portion of at least one of the first electrode member and the second electrode member. Sometimes it is good to be an insulated braided member that allows the electrical contact through the gap of the stitch.

[0015] Preferably, the load sensor is provided at a position of the first electrode member and the second electrode member at at least one position in a longitudinal direction of the first electrode member and the second electrode member. Preferably, the apparatus further comprises insulating fixing means for fixing the relationship.

Further, preferably, the fixing means may fix the first electrode member and the second electrode member by tightening them from the outer periphery.

Preferably, at least one of the first electrode member and the second electrode member has predetermined tensile strength and resilience to bending deformation, and at least an outer peripheral portion has elasticity. And a conductive second metal wire spirally wound horizontally around the outer periphery of the center member as the conductive metal member.

Still preferably, at least one of the first electrode member and the second electrode member is provided so as to cover an outer peripheral surface of the center member from above the second metal wire. A conductive coating layer made of a conductive resin or a conductive rubber may be further provided.

Preferably, at least one of the first electrode member and the second electrode member is formed by twisting or binding a plurality of metal wires. Good.

Preferably, at least one of the first electrode member and the second electrode member is formed of a single metal wire.

[0021] Preferably, the load sensor further includes an outer tube formed of an elastic material and surrounding the outside of the elastic tube.

Further, the technical means for achieving the above object is to prevent foreign matter from being caught when the opening portion opened and closed by the opening / closing member is closed by the opening / closing member at least by the opening portion and the opening / closing member. A trapping detection device that is detected by a load detection unit provided on one of the two,
The load sensor according to any one of claims 1 to 14 is used as the load detection unit.

Further, a technical means for achieving the above object is a load detecting device for detecting a load by load detecting means provided two-dimensionally, wherein the load detecting means is two-dimensionally provided. A plurality of the load sensors according to any one of claims 1 to 14 arranged are used.

Further, a technical means for achieving the above object is a load detecting device for detecting a load by load detecting means provided two-dimensionally, wherein the load detecting means is two-dimensionally provided. The load sensor according to any one of claims 1 to 14, which is arranged in a curved manner, is used.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> FIG. 1 is an axially parallel sectional view of a load sensor according to a first embodiment of the present invention.
2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a sectional view taken along line BB of FIG.
It is sectional drawing. This load sensor 10 is shown in FIGS.
As shown in the figure, the elastic conductive tube (elastic tube) 11
And first and second electrode members 12 and 13, an insulated linear member (insulating member) 15 wound around and mounted on the first electrode member 12, and an insulating fixing member (fixing means) 16. ing. In the present embodiment, the first and second electrode members 12 and 13 are provided one by one. However, a plurality of first electrode members 12 may be provided, and a plurality of second electrode members 12 and 13 may be provided.
May be provided.

The elastic conductive tube 11 is shown in FIGS.
As shown in (1), at least a part of the circumferential direction is a conductive portion having elasticity (here, the entire elastic conductive tube 11 is made of an elastic conductive material such as conductive rubber or elastic conductive resin). It is formed of a material and the entire circumferential section is a conductive portion.)

The first and second electrode members 12, 13 are:
As shown in FIG. 1, the elastic conductive tube 11 has an elongated shape that is bendable in one direction and is provided in the elastic conductive tube 11 in parallel with each other. The two electrode members 12, 13 are shown in FIGS.
As shown in the figure, a central member 21 having a predetermined tensile strength and a resilience to bending deformation, and having an elongated shape having a circular cross section and having elasticity at least in its outer peripheral portion, is easily bent.
And a conductive thin metal wire (second metal wire) 2 which is spirally and densely wound horizontally around the outer periphery of the center member 21 at a predetermined pitch.
3 is provided. As a material of the metal wire 23, a nickel alloy, copper, a copper alloy, nichrome, stainless steel, or the like is used, and it is preferable to use an oxidation-resistant and corrosion-resistant metal. Here, as shown in FIG. 6, a part of the cross section (here, about half) of the metal wire 23 is used to prevent displacement.
Are wound around the surface of the center member 21.

As shown in FIGS. 2 and 3, the center member 21 has a center reinforcing member (tension member) 21a having a high tensile strength and an elastic material (extruded around the center reinforcing member 21a by extrusion molding). An elastic layer (here, an elastic insulating layer) 21 made of an elastic insulating material here)
b. As the material of the central reinforcing member 21a, a fiber obtained by twisting or bundling fibers having high tensile strength (such as aramid fibers) is used. As the elastic insulating material of the elastic insulating layer 21b, fluorine rubber, silicone rubber, EPDM, or the like is used.

The insulated linear member 15 has an elongated shape having an insulating property at least at its outer peripheral portion.
It comprises a metal wire (first metal wire) and an insulating coating layer formed by applying and firing an insulating material such as enamel on the surface of the metal wire. Such an insulated linear member 15 is spirally wound around the first electrode member 12 at a predetermined winding interval D, as shown in FIGS. Here, as shown in FIGS. 7 and 8, the winding interval D and the like can be easily adjusted in accordance with the sensor sensitivity and the like as described later.

As shown in FIGS. 1 and 3, the fixing member 16 is composed of insulating first and second surrounding members 16a, 16a.
b, so that the positional relationship between the two electrode members 12 and 13 is fixed at at least one location (here, one location at the center) in the longitudinal direction of the two electrode members 12 and 13. I have. The first outer surrounding member 16a is mounted so as to cover the outer peripheral portion of one of the two electrode members 12, 13, and prevents electrical contact between the two electrode members 12, 13 at the fixed portion. The second surrounding member 16b is mounted from above the mounted first surrounding member 16a.
2 and 13 are tightened and fixed from the outer periphery. First and second
As the outer surrounding members 16a and 16b, an insulated linear member (a string, a thread, a covered electric wire, or the like), an insulating tube (a heat-shrinkable tube, or the like) or an insulating tape that is wound and fixed is used. Alternatively, the fixing between the two electrode members 12 and 13 may be performed by an insulating adhesive instead of the fixing member 16.

In the present embodiment, the fixing between the two electrode members 12 and 13 is performed by the fixing member 16.
If the unintentional electrical contact between the two electrode members 12 and 13 when no load is applied can be prevented by reducing the winding interval D of the insulated linear member 15 or the like, the fixing member 1
6 may be omitted.

FIG. 1 shows one end of each of the electrode members 12 and 13.
As shown in the figure, the lead wire 24 is connected by crimping with a crimping fitting, winding of the core wire of the lead wire 24 around the electrode members 12 and 13, and the like. Insulating tubes (or insulating tapes or the like) 25 are attached to the connection portions of the lead wires 24 of the electrode members 12 and 13, respectively. Then, an insulating tube (or insulating tape or the like) 26 is further mounted on the insulating tube 25. An insulating tube (or an insulating tape or the like) 27 is attached to the other end of each of the electrode members 12 and 13 (from the top of the insulating linear member 15 in the case of the first electrode member 12).

The assembly of the load sensor 10 is as follows.
Generally, after the insulating linear member 15 is continuously wound around the outer periphery of the first electrode member 12 in the longitudinal direction of the electrode member 12 by a winding machine or the like, the two electrode members 12 and 13 are fixed by the fixing member 16. The first insulated linear member 15 is mounted.
This is performed by inserting the electrode member 12 and the second electrode member 13 into the elastic conductive tube 11.

With such a configuration, when no load is applied to the load sensor 10 (non-load applied state),
The insulated linear member 15 separates the first electrode member 12 from the second electrode member 13 and the elastic conductive tube 11 so as to be electrically insulated. In the present embodiment, the second electrode member 13 is in electrical contact with the elastic conductive tube 11 irrespective of whether or not a load is applied. The conductive tube 11 may be electrically contacted.

On the other hand, when a load having a predetermined strength or more is applied to the load sensor 10 (load applied state), the elastic conductive tube 1
When the inner cavity of the first electrode member 12 is elastically deformed so as to be crushed, as shown in FIG. 9, the first electrode member 12 is inserted through the gap between the spirally wound insulating linear members 15.
Electrical contact between the electrode member and the elastic conductive tube 11 or between the electrode members 12 and 13 is allowed.
The two electrode members 12 and 13 are electrically connected via the elastic conductive tube 11 or directly.
The load sensor 10 detects the presence or absence of the application of a load by detecting the presence or absence of direct or indirect electrical conduction between the two electrode members 12 and 13 via the lead wire 24. With the release of the load application, the elastic conductive tube 11 returns to the original shape shown in FIG. 1, and the electrical contact between the first electrode member 12 and the elastic conductive tube 11 or the second electrode member 13 is reduced. Will be resolved.

Here, the thickness of the insulating linear member 15 (the width W of the first electrode member 12 in the longitudinal direction (see FIG. 7) and the thickness of the electrode member 12 in the radial direction) and the winding interval D are as follows. The load strength required for the first electrode member 12 to make electrical contact with the elastic conductive tube 11 or the second electrode member 13 due to the elastic deformation at the time of applying a load, that is, the sensor sensitivity is set to a desired level. You. For example, in the example of FIG. 7, the thickness (outer diameter) of the insulated linear member 15 is set.
Is set to 0.6 mm and the winding interval D is about 15 mm
In the example of FIG. 8, the thickness (outer diameter) of the insulating linear member 15 is set to 0.3 mm, and the winding interval D
Is set to about 5 mm.

As described above, according to the present embodiment, the assembling step of the load sensor 10 is substantially the same as the step of assembling the insulating linear member 15 on the outer peripheral portion of the first electrode member 12, This is an easy assembling process of inserting the first and second electrode members 15 together with the first and second electrode members 12 and 13 into the elastic conductive tube 11, and has a simple structure and can be manufactured easily and at low cost.

Further, the insulating linear member 15 provided on the outer peripheral portion of the first electrode member 12 is provided between the first electrode member 12 and the second electrode member 13 and when the first electrode member 12 is not applied with a load. Since the member 12 and the elastic conductive tube 11 are electrically insulated from each other, the first electrode member 12 and the second electrode member 13 can be electrically connected to each other even if the load sensor is curved with a large curvature. Electrode members 1 due to inadvertent electrical contact between them and between first electrode member 12 and elastic conductive tube 11
An appropriate function can be achieved without erroneous detection of the load due to conduction between the second and the third.

Further, the first and second electrode members 12,
13 is provided with a metal wire 23 extending in the longitudinal direction on the outer periphery thereof, so that the impedance of the first and second electrode members 12 and 13 which are the conductive paths of the load sensor 10 can be reduced, and the load sensor The degree of freedom in designing a circuit configuration such as a detection circuit connected to the circuit 10 can be increased.

Further, since the first and second electrode members 12 and 13 are inserted into the elastic conductive tube 11, the load sensor is compared with a case where a single electrode member is inserted into the elastic conductive tube 11. It is possible to improve the strength of the load sensor 10 against bending (bending), deformation and extension of the load sensor 10 due to load application.

Furthermore, due to the presence of the insulating linear member 15, careless care is taken between the first and second electrode members 12, 13 and between the first electrode member 12 and the elastic conductive tube 11 when no load is applied. Since electrical contact can be prevented, both electrode members 1
The gap size between the electrodes 2 and 13 and between the electrode members 12 and 13 and the elastic conductive tube 11 can be set small, and the cross-sectional size of the sensor 10 can be reduced.

At least one of the thickness (at least one of the width W in the longitudinal direction of the electrode member 12 and the thickness in the radial direction of the electrode member 12) of the insulating linear member 15 and the winding interval D is adjusted. By doing so, the sensor sensitivity can be easily adjusted.

Since the insulating linear member 15 is spirally wound around the electrode member 12 and mounted, the insulating linear member 15 can be firmly mounted on the electrode member 12. For this reason, even if the load sensor 10 is bent or extended, the winding shape of the insulating linear member 15 is firmly held without the insulating linear member 15 being substantially displaced or deformed on the electrode member 12. And the reliability of load detection sensitivity can be kept constant.

Further, since the insulated linear member 15 can be easily wound and mounted accurately at a uniform winding interval, when the load detection object comes into contact with the load sensor 10, the insulated linear member 15 is Both electrode members 1 in the way
2, 13 and between the electrode member 12 and the elastic conductive tube 1
1 is not substantially hindered, the load can be reliably detected even with a small load detection target, and substantially continuously with respect to the longitudinal direction of the load sensor 10. Load detection can be performed at any position.

Further, the winding of the insulated linear member 15 can be continuously performed at a substantially arbitrary length in the longitudinal direction of the electrode member 12 by a winding device or the like. Can be easily created at low cost.

Further, since the insulated wire member 15 is formed with a metal wire as a core material, when the insulated wire member 15 is wound around the electrode member 12, the insulated wire member 15 retains the shape of the metal wire. Fifteen wrapped shapes are maintained.
For this reason, it is possible to firmly fix the insulated linear member 15 only by winding without using fixing means such as an adhesive, and to have a moderately strong and flexible curve against bending deformation. It is possible to provide a load sensor 10 that is capable of being robust.

Further, even if the electrode member 12 and the insulated wire member 15 are cut in the middle without performing any special terminal treatment such as bonding and fixing the insulated wire member 15, the insulated wire member 15 wound around the cut portion can be used. Does not come off from the electrode member 12 and is easy to handle.

Further, such an insulated linear member 15 is spirally wound around the electrode member 12 to thereby form the electrode member 1.
2 can be strengthened, the electrode member 12 can be easily inserted into the elastic conductive tube 11, and workability can be improved.

The lead wire 2 at one end of the electrode member 12
In the electrical connection part 4, the lead wire 24 and the electrode member 12
By tightly winding the insulated linear member 15 from above the electrical connecting portion, the electrical connecting portion and the elastic conductive tube 11 can be insulated without providing a special insulating member.

Further, at least one portion of the two electrode members 12, 13 in the longitudinal direction is fastened from the outer periphery by the fixing member 16, and the positional relationship between the two electrode members 12, 13 is fixed. When no load is applied, for example, when the electrodes 12 and 13 ride on each other,
13 can be reliably prevented from inadvertently making electrical contact.

The fixing member 16 is connected to both electrode members 12 and 1.
3 is fastened from the outer periphery to fix both electrode members 1
The positional relationship between 2 and 13 can be reliably fixed.

Further, the electrode members 12 and 13 have predetermined tensile strength and resilience to bending deformation, and have an elongated central member 21 having at least an outer peripheral portion having elasticity.
And the conductive metal wire 23 spirally wound around the outer periphery of the center member 21, so that the load sensor 10 can be variously arranged in a state where the load sensor 10 is bent and deformed. This makes it possible to provide the load sensor 10 having high mechanical strength, high resilience to bending, and excellent impact resistance.

Further, with such a configuration of the electrode members 12 and 13, the connection of the signal extraction lead wire 24 can be easily performed by using, for example, a crimping fitting.

<Second Embodiment> FIG. 10 shows a second embodiment of the present invention.
It is an axis parallel sectional view of a load sensor concerning an embodiment. The only difference between the load sensor 10 according to the present embodiment and the load sensor 10 according to the first embodiment is that an insulating linear member 15 is provided on the outer peripheral portion of the second electrode member 13 as well.
Corresponding parts have the same reference characters allotted, and description thereof will not be repeated. As shown in FIG. 10, in the present embodiment, the first
As in the case of the embodiment, the insulated linear member 15
Is also spirally wound around the outer periphery of the electrode member 13.

With such a configuration, the same effects as those of the first embodiment can be obtained by this embodiment, and by providing an insulating linear member on both electrode members 12 and 13, the distance between both electrode members 12 and 13 can be improved. Inadvertent conduction can be more reliably prevented.

<Modification> In each of the above embodiments,
The insulated wire member 15 was constituted by an enamel wire or the like in which a metal wire was covered with an insulating coating layer. The insulated wire member 15 was formed by extruding an insulating resin on the surface of the metal wire as a core material and the metal wire. It may be constituted by a covered electric wire or the like formed with the formed resin coating.

Further, as a further modified example of the insulated wire member 15, the insulated wire member 15 may be constituted by a string member (including a thread member) or a fiber member formed of an insulating material. . In this case, since the insulated linear member 15 has a simple configuration, the insulated linear member 15 can be manufactured at low cost, and the cost of the load sensor 10 can be reduced.

Further, as another modified example of each of the above-described embodiments, as shown in FIG. 11, an insulating braided member (insulating member) 28 may be provided instead of the above-mentioned insulated linear member 15. As shown in FIG. 11, the insulating braided member 28 is formed by knitting a plurality of (or a single) yarn material formed of insulating fibers (aramid fiber, nylon fiber, or the like) into a cylindrical shape. It is provided so as to cover the outer peripheral surface of the first electrode member 12 (or both electrode members 12, 13). From the viewpoint of mechanical strength and resilience to compression in the thickness direction of the insulating braided member 28, aramid fiber is used here as the material of the yarn material,
Other fiber materials such as nylon fibers and glass fibers may be used. Further, the thread material may be formed of one insulating linear material (rubber thread or the like) instead of the fiber. Here, the formation of the insulating braided member 28 is performed by continuously knitting the thread material into a cylindrical shape on the electrode members 12 and 13, but the cylindrical insulating braided member 28 is formed first. After that, the electrode member 1 is placed in the insulating braided member 28.
2, 13 may be inserted.

And, such an insulating braided member 28
In the non-load applied state, the electrode members 12, 1 provided between the electrode members 12, 13 and the insulating braid member 28 are provided.
3 and the elastic conductive tube 11 are separated from each other to be electrically insulated, while the elastic deformation of the load sensor 10 due to the application of a load having a predetermined strength or more causes the two electrode members to pass through the gaps of the stitches. Electric contact between the elastic conductive tube 11 and the electrode members 12, 13 provided with the insulating braid member 28 or between the 12, 13 or the insulating braid member 28 is allowed.

According to the modification shown in FIG. 11, by using the insulating braided member 28 as the insulating member, the portion where the first and second electrode members 12 and 13 face each other or the two electrode members 12 and 13 are used. If the portion 13 and the elastic conductive tube 11 are opposed to each other, the load can be accurately detected with uniform sensitivity even if a load is applied to any point, and the reliability is high.

Further, an insulating braided member 28 is used as an insulating member.
Therefore, the gap size between the two electrode members 12 and 13 (or the gap size between the two electrode members 12 and 13 and the gap size between the two electrode members 12 and 13 and the elastic conductive tube 11) is reduced. If necessary, the thickness can be reduced to about the thickness of the insulating braid member 28, which is suitable for reducing the cross-sectional size of the sensor 10.

Further, when the application of the load is released, the insulating braid member 28 is restored to the original thickness by the elastic restoring force in the thickness direction peculiar to the braid from the state where the insulating braid member 28 is thinly compressed when the load is applied. Between both electrode members 12 and 13 at the time of application (or between both electrode members 12 and 13 and between both electrode members 1 and 13).
Inadvertent electrical contact between the elastic conductive tube 11 and the elastic conductive tube 11) can be reliably prevented, and the reliability is high in this respect as well.

Further, such elastic restoring force of the insulating braided member 28 is hardly impaired even in repeated compression in the thickness direction, so that it is excellent in durability and reliability.

Further, the first and second electrode members 12,
As a modification of the thirteenth embodiment, the central member 21
May be further provided with a conductive coating layer made of a conductive resin or a conductive rubber provided so as to cover the outer peripheral surface of. In this case, as compared with the case where the insulated linear member 15 is directly wound on the horizontally wound metal wire 23, the contact area and the frictional force between the insulated linear member 15 and the electrode members 12 and 13 (locking against displacement) Force) can be increased, and the displacement of the insulated linear member 15 on the electrode members 12 and 13 can be prevented. As a result, the insulated linear member 15 can be prevented.
Can be held more reliably.

As a further modification of the electrode members 12, 13, the electrode members 12, 13 may be formed by twisting or binding a plurality of metal wires. In this case, since the electrode members 12 and 13 have a simple configuration, the electrode members 12 and 13 can be manufactured at low cost, and the cost of the load sensor 10 can be reduced.

Further, as still another modified example of the electrode members 12, 13, the electrode members 12, 13 may be constituted by a single metal wire. In this case, in addition to the advantage that the electrode members 12 and 13 have a simple configuration,
Since the electrode members 12 and 13 are formed of a single metal wire, there is an advantage that the load sensor 10 can be held in a predetermined bent shape using the shape holding characteristics of the electrode members 12 and 13.

As a modified example of the load sensor 10 according to each embodiment, as shown in FIG. 12, an outer tube 31 formed of an elastic material and surrounding the outside of the elastic conductive tube 11 is further provided. You may. In this case, since the outer tube 31 is further provided outside the elastic conductive tube 11, the outer tube 31 protects the elastic conductive tube 11 and the electrode members 12 and 13 which are the main body of the load sensor 10. Can be.

In each of the above-described embodiments and the modifications thereof, the winding pitch of the insulated wire member 15 is not necessarily required to be constant, but may be wound tightly, coarsely, or changed as necessary. It is possible to attach. For example,
By tightly winding it, it is possible to use that part as an insulating part or as a fixed part of the sensor 10. Further, by roughly winding the sensor, the sensor sensitivity at that portion can be increased.

<Application Example> Here, FIG.
An application example of the load sensor 10 according to each of the above-described embodiments and their modifications will be described with reference to FIG. In addition, the application example of the load sensor 10 can consider various uses, and is not limited to the content described here.

In the application example shown in FIG.
Is applied to a pinch detection device of a power window device of a vehicle. In this application example, as shown in FIG. 13, the load sensor 10 serves as a load detection unit for detecting the trapping of foreign matter, and a window frame portion of a window 43 opened and closed by an electrically driven window glass (opening / closing member) 41. 45 (as another arrangement example, it may be arranged at the downstream end of the window glass 41 in the closing direction).

Here, the load sensor 10 is applied to a pinch detection device of a power window device of a vehicle.
The load sensor 10 may be applied to a vehicle door, a sunroof, or a pinch detection device at an entrance of a building or an elevator.

In the application example shown in FIGS. 14 and 15, the load sensor 10 is applied to a sheet-like load detecting device. In the application example of FIG. 14, a plurality of load sensors 10 are two-dimensionally arranged on the sheet member 51, and the load detection is performed two-dimensionally by the plurality of load sensors 10. In the application example of FIG. 15, a single load sensor 10 is curved two-dimensionally (here, “U” -shaped) and arranged on the sheet member 53, and the load sensor 10 performs two-dimensional load detection. Is to be performed. In the modification shown in FIGS. 14 and 15,
Although the load sensor 10 is disposed on the sheet members 51 and 53, the load sensor 10 may be disposed so as to be sandwiched between two sheet members, or may be formed of an elastic material such as sponge or rubber. The load sensor 10 may be arranged so as to be embedded in the plate-like elastic body.

[0073]

According to the present invention, an insulating member is provided on the outer peripheral portion of at least one of the first and second electrode members, and the insulating member is provided. The assembly can be easily performed only by inserting the first and second electrode members into the elastic tube, and the structure can be simplified, and the manufacturing can be performed easily and at low cost.

Further, the insulating member provided on the outer peripheral portion of at least one of the first electrode member and the second electrode member can be used when the first electrode member, the second electrode member and the second electrode member are not subjected to a load. Are separated and electrically insulated, so that even if the load sensor is curved with a large curvature,
The first electrode member and the second electrode member do not inadvertently come into contact with each other, so that erroneous detection of the load does not occur, and the first electrode member can function properly.

Further, the first and second electrode members include:
Since a metal conductive member extending in the longitudinal direction is provided on the outer peripheral portion, the impedance of the first and second electrode members, which are the conductive paths of the load sensor, can be reduced, and a detection circuit or the like connected to the load sensor can be provided. The degree of freedom in designing the circuit configuration can be expanded.

Further, since the first and second electrode members are inserted into the elastic tube, the bending (bending) and load of the load sensor can be reduced as compared with the case where a single electrode member is inserted into the elastic tube. It is possible to improve the strength of the load sensor against deformation and extension due to the application.

Furthermore, since the presence of the insulating member can prevent inadvertent electrical contact between the first and second electrode members when no load is applied, the gap between the two electrode members can be set small. In addition, the cross-sectional size of the sensor can be reduced.

According to the second and third to fourteenth aspects of the present invention, an insulating member is provided on an outer peripheral portion of at least one of the first and second electrode members, and the insulating member is provided on the first electrode member. The assembly can be easily performed simply by inserting the elastic member into the elastic tube together with the second electrode member, and the structure is simple, and the manufacturing can be performed easily and at low cost.

Further, the insulating member provided on the outer peripheral portion of at least one of the first electrode member and the second electrode member can be used when the first electrode member, the second electrode member and the second electrode member are not subjected to a load. Between and at least one of the electrode members provided with an insulating member and the conductive portion of the elastic tube to electrically insulate, even if the load sensor is arranged with a large curvature in a curved manner, First electrode member and second electrode member
Erroneous detection of a load occurs due to conduction between both electrode members due to inadvertent electrical contact between the two electrode members and at least one of the electrode members provided with an insulating member and the conductive portion of the elastic tube. And can function properly.

Further, the first and second electrode members include:
Since a metal conductive member extending in the longitudinal direction is provided on the outer peripheral portion, the impedance of the first and second electrode members, which are the conductive paths of the load sensor, can be reduced, and a detection circuit or the like connected to the load sensor can be provided. The degree of freedom in designing the circuit configuration can be expanded.

Further, since the first and second electrode members are inserted into the elastic tube, the bending (curvature) and load of the load sensor are smaller than when a single electrode member is inserted into the elastic tube. It is possible to improve the strength of the load sensor against deformation and extension due to the application.

Further, due to the presence of the insulating member, there is a gap between the first and second electrode members when no load is applied and between at least one of the electrode members provided with the insulating member and the conductive portion of the elastic tube. Since ready electrical contact can be prevented, the gap between both electrode members and between both electrode members and the conductive portion of the elastic tube can be set small, and the cross-sectional size of the sensor can be reduced.

According to the third aspect of the present invention, by adjusting at least one of the thickness and the winding interval of the insulating linear member, the first and second insulating members are elastically deformed when a load is applied. It is possible to easily adjust the load intensity required for making electrical contact between the electrode members or between the electrode member provided with the insulated linear member and the conductive portion of the elastic tube, that is, the sensor sensitivity.

Further, since the insulating linear member is spirally wound around the electrode member and mounted, the insulating linear member can be firmly mounted on the electrode member. Therefore, even if the load sensor is bent or extended, the insulated linear member does not substantially displace or lose its shape on the electrode member.
The winding shape of the insulated linear member can be firmly held, and the reliability of load detection sensitivity can be kept constant.

Further, since the insulated wire member can be easily wound and mounted accurately at a uniform winding interval, the insulated wire member becomes an obstacle when the load detection object comes into contact with the load sensor. The conduction between the two electrode members and at least one of the electrode members provided with the insulated linear members and the conductive portion of the elastic tube is not substantially hindered, and a small load detection target is However, the load can be reliably detected, and the load can be detected substantially continuously at any position in the longitudinal direction of the load sensor.

In addition, the winding of the insulated linear member can be continuously performed at a substantially arbitrary length in the longitudinal direction of the electrode member by a winding device or the like. Can be easily created.

According to the fourth and fifth aspects of the present invention,
Since the insulated wire member is formed with the metal wire as the core material, when the insulated wire member is wound around the electrode member, the winding shape of the insulated wire member is maintained by the shape holding characteristics of the metal wire. For this reason, without using a fixing means such as an adhesive, it is possible to firmly fix the insulated linear member only by winding, and it is possible to make the elastic member moderately strong and flexible against bending deformation. In addition, a load sensor having robustness can be provided.

Further, even if the electrode member and the insulated wire member are cut in the middle without performing special terminal treatment such as bonding and fixing the insulated wire member, the insulated wire member wound at the cut portion is not removed from the electrode member. It is easy to handle without unraveling.

Further, by spirally winding such an insulated wire member around the electrode member, the stiffness of the electrode member can be strengthened, and the electrode member can be easily inserted into the elastic tube. Performance can be improved.

When a lead wire for signal extraction is connected to the end of the electrode member, a special insulating wire member is densely wound over the electrical connection portion between the lead wire and the electrode member, thereby forming a special wire. It is also possible to insulate the electric connection part from the conductive part of the elastic tube without providing an insulating member.

According to the sixth aspect of the present invention, since the insulating linear member has a simple configuration, the insulating linear member can be manufactured at low cost, and the cost of the load sensor can be reduced.

According to the seventh aspect of the present invention, by using an insulating braided member as the insulating member, a portion where the first and second electrode members are opposed to each other or a conductive portion of the both electrode members and the elastic tube. If the load is applied to any part, the load can be accurately detected with uniform sensitivity even if a load is applied to any point, and the reliability is high.

Further, since the insulating braided member is used as the insulating member, the gap between the two electrode members (or the gap between the two electrode members and the gap between the two electrode members and the conductive portion of the elastic tube) can be reduced. (Dimension) can be reduced to about the thickness of the braided member if necessary, which is suitable for reducing the cross-sectional size of the sensor.

Further, when the application of the load is released, the insulating braided member is changed from a state in which it is thinly compressed when the load is applied, to
In order to restore to the original thickness by the elastic restoring force in the thickness direction peculiar to the braid, care must be taken between both electrode members (or between both electrode members and between both electrode members and the conductive part of the elastic tube) when no load is applied. Electrical contact can be reliably prevented,
In this respect, reliability is high.

Further, such an elastic restoring force of the insulating braided member is hardly impaired even in repeated compression in the thickness direction, so that it is excellent in durability and reliability.

According to the eighth aspect of the present invention, the positional relationship between the first electrode member and the second electrode member is insulated at at least one position in the longitudinal direction of the first electrode member and the second electrode member. To prevent the first electrode member and the second electrode member from inadvertently making electrical contact when no load is applied, such as when the first electrode member and the second electrode member ride on each other. Can be.

According to the ninth aspect of the present invention, since the fixing means tightens and fixes the first electrode member and the second electrode member from the outer periphery, the positional relationship between the two electrode members can be reliably fixed. it can.

According to the tenth aspect, at least one of the first and second electrode members has a predetermined tensile strength and resilience to bending deformation, and at least the outer peripheral portion has a predetermined strength. The load sensor is bent and deformed because it has an elongated center member having elasticity and a conductive second metal wire spirally wound horizontally around the center member. And can be easily arranged in accordance with various arrangement forms.
A load sensor having high mechanical strength, high resilience to bending, and excellent impact resistance can be provided.

Further, with such a configuration of at least one of the first and second electrode members, it is possible to easily connect a signal extraction lead wire to the electrode member.

According to the eleventh aspect, at least one of the first electrode member and the second electrode member is provided so as to cover the outer peripheral surface of the central member from above the metal wire. Since the conductive coating layer made of a conductive resin or a conductive rubber is further provided, the insulated wire member and the electrode member are compared with the case where the insulated wire member is directly wound over the horizontally wound second metal wire. Contact area and frictional force (locking force against displacement) can be increased,
The displacement of the insulated linear member on the electrode member can be prevented, and as a result, the winding shape of the insulated linear member can be more reliably held.

According to the twelfth aspect of the present invention, since the electrode member has a simple configuration, the electrode member can be manufactured at low cost, and the cost of the load sensor can be reduced.

According to the thirteenth aspect, since the electrode member has a simple configuration, the electrode member can be manufactured at low cost, and the cost of the load sensor can be reduced.

Further, since the electrode member is formed of a single metal wire, there is an advantage that the load sensor can be held in a predetermined bent shape by utilizing the shape holding characteristics of the electrode member.

According to the fourteenth aspect of the present invention, since the outer tube is further provided outside the elastic tube, the elastic tube and the electrode member, which are the main body of the load sensor, are protected by the outer tube. be able to.

According to the fifteenth aspect of the present invention, the load sensor according to any one of the first to fourteenth aspects is used as the load detecting means, so that the entrapment can be detected with high sensitivity and reliability. In addition, a highly reliable and low-cost pinch detection device can be provided.

According to the present invention, the load detecting means is two-dimensionally disposed.
4 to use a plurality of load sensors described in any of
The load can be detected with high sensitivity and reliability, and a highly reliable and low-cost load detector can be provided.

According to the seventeenth aspect of the present invention, since the load sensor according to any one of the first to fourteenth aspects is used as the load detecting means, the load sensor is arranged in a two-dimensionally curved manner. Thus, a highly reliable and low-cost load detecting device can be provided.

[Brief description of the drawings]

FIG. 1 is an axially parallel sectional view of a load sensor according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along the line BB of FIG. 1;

FIG. 4 is a sectional view perpendicular to the axis of a first electrode member and an insulated linear member.

FIG. 5 is a side view of the first and second electrode members.

FIG. 6 is an enlarged sectional view of a main part of the first and second electrode members.

FIG. 7 is a diagram showing a state where an insulating linear member is wound around a first electrode member.

FIG. 8 is a diagram showing a state where an insulated linear member is wound around a first electrode member.

FIG. 9 is a diagram showing a state where a load is applied to the load sensor of FIG. 1;

FIG. 10 is an axially parallel sectional view of a load sensor according to a second embodiment of the present invention.

FIG. 11 is a diagram showing a main configuration of a modification of the first and second embodiments.

FIG. 12 is a diagram showing a modification of the first and second embodiments.

FIG. 13 is a diagram showing an arrangement form in a case where the load sensors according to the first and second embodiments are applied to a pinch detection device of a power window device of a vehicle.

FIG. 14 is a diagram showing an arrangement form in a case where the load sensors according to the first and second embodiments are applied to a sheet-like load detection device.

FIG. 15 is a diagram showing an arrangement in which the load sensors according to the first and second embodiments are applied to a sheet-like load detecting device.

FIG. 16 is a sectional view of a conventional load sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Load sensor 11 Elastic conductive tube 12 1st electrode member 13 2nd electrode member 15 Insulated linear member 16 Fixed member 21 Center member 21a Center reinforcement member 21b Elastic insulation layer 23 Metal wire 28 Insulated braided member 31 Surrounding tube 45 Window frame 51, 53 Sheet member

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahiro Kume 1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi F-term in Auto Network Engineering Laboratory Co., Ltd. (reference) 3D127 AA02 DF35 FF14

Claims (17)

[Claims] 1. An elastic tube formed of an elastic material, and a metal conductive member having an elongated shape and being continuous in a longitudinal direction at least on an outer peripheral portion thereof, and inserted into the elastic tube so as to be parallel to each other. The first and second electrode members having insulating properties, provided on the outer peripheral portion of at least one of the first and second electrode members, and Insulation that allows electrical contact between the first electrode member and the second electrode member, while separating the first electrode member and the second electrode member when no load is applied, and electrically insulating the first electrode member and the second electrode member. And a member, wherein a load is detected based on a state of electrical conduction between the first electrode member and the second electrode member. 2. An elastic tube which is formed of an elastic material and has a conductive portion having elasticity in at least a part of its circumference in a circumferential direction; and a metal tube which has an elongated shape and is continuous with at least an outer peripheral portion in a longitudinal direction. A first and second electrode member provided with a conductive member and inserted into the elastic tube so as to be parallel to each other; and an insulating member, wherein the first and second electrode members have an insulating property. The first electrode member and the second electrode member at the time of applying a load, or at least one of the electrode members. While permitting electrical contact of the elastic tube to the conductive portion, between the first electrode member and the second electrode member and at least one of the electrode members when no load is applied. An insulating member that electrically insulates between the conductive portion of the elastic tube and a conductive state of the first electrode member and the second electrode member. A load sensor wherein a load is detected based on a state of electrical conduction via the conductive portion. 3. The insulating member has an elongated shape having an insulating property at least on an outer peripheral portion thereof, and a predetermined shape is provided on an outer peripheral portion of at least one of the first electrode member and the second electrode member. The load sensor according to claim 1, wherein the load sensor is an insulated linear member spirally wound with a winding interval. 4. The insulating wire member according to claim 3, wherein the insulating wire member includes a first metal wire, and an insulating coating layer formed by being applied to a surface of the first metal wire. The load sensor as described. 5. The insulated linear member includes: a first metal wire; and a resin coating formed by extruding an insulating resin on a surface of the first metal wire. Item 3. The load sensor according to Item 3. 6. The load sensor according to claim 3, wherein the insulated linear member is a string-shaped member or a fiber-shaped member formed of an insulating material. 7. The insulating member is made of an insulating material, and is provided so as to cover an outer peripheral portion of at least one of the first electrode member and the second electrode member. 3. The load sensor according to claim 1, wherein the load sensor is an insulating braided member that allows the electrical contact through a gap portion. 4. 8. The load sensor fixes a positional relationship between the first electrode member and the second electrode member at at least one position in a longitudinal direction of the first electrode member and the second electrode member. 2. The apparatus according to claim 1, further comprising: an insulating fixing means.
8. The load sensor according to any one of claims 7 to 7. 9. The load sensor according to claim 8, wherein the fixing unit tightens and fixes the first electrode member and the second electrode member from the outer periphery. 10. An elongated member having at least one of the first electrode member and the second electrode member having predetermined tensile strength and resilience to bending deformation, and having at least an outer peripheral portion having elasticity. A central member having a shape, a conductive second metal wire spirally wound around the outer periphery of the central member as the conductive metal member,
The load sensor according to any one of claims 1 to 9, further comprising: 11. A conductive resin provided so that at least one of the first electrode member and the second electrode member covers an outer peripheral surface of the center member from above the second metal wire. The load sensor according to claim 10, further comprising a conductive coating layer made of conductive rubber. 12. A method according to claim 1, wherein at least one of the first electrode member and the second electrode member is formed by twisting or binding a plurality of metal wires. The load sensor according to claim 1. 13. The method according to claim 1, wherein at least one of the first electrode member and the second electrode member is formed of a single metal wire. The load sensor according to 1. 14. The load sensor according to claim 1, wherein the load sensor further includes an outer tube formed of an elastic material and surrounding the outside of the elastic tube. 15. A load detecting means provided in at least one of the opening and the opening / closing member detects the entrapment of foreign matter when the opening opened / closed by the opening / closing member is closed by the opening / closing member. A pinch detection device, wherein the load sensor according to any one of claims 1 to 14 is used as the load detection unit. 16. A load detecting device for detecting a load by two-dimensionally arranged load detecting means, wherein the load detecting means is two-dimensionally arranged. A load detection device, comprising: a plurality of the load sensors described in the above. 17. A load detecting device for detecting a load by two-dimensionally arranged load detecting means, wherein the load detecting means is arranged in a two-dimensionally curved manner. A load detection device using the load sensor according to any one of the above.