JP2003329520A - Pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure sensor which surely detects a human coming in and going out, which properly displays a function as a heating element for a heating system, and which is installed properly so as to deal surely with different needs required from a floor surface. <P>SOLUTION: The pressure sensor 10 is provided with a sensor mainframe 12, and a resistance detector 14 used to detect an electrical resistance of the sensor mainframe 12. The sensor mainframe 12 is provided with a hollow thread as a substrate 16, and a conductive polymer 18 carried and held by the substrate 16. The conductive polymer 18 comprises conductive materials 20 and a binder 22 carrying and holding the conductive materials 20. The binder 22 has a coefficient of elasticity used to displace a distance between the conductive materials 20, in such a way that an electrical resistance value of the conductive polymer 18 is increased by 10 Ω or more due to a pressure by the weight of a human body. The coefficient of elasticity of the binder 22 is adjusted in such a way that 5 to 10% of a synthetic rubber is contained in terms of a weight ratio with respect to the whole of the binder 22. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a pressure sensor installed in an office, a residence or the like for detecting the intrusion of a person, and particularly to a floor surface corresponding to heating of the floor. The present invention relates to a highly practical pressure sensor that can be appropriately installed.

[0002]

2. Description of the Related Art For example, a sensor used to detect the intrusion of an intruder into an office or a residence to ensure security, or a sensor used as a sensitive switch such as an automatic door is generally used. In general, sensors using laser beams and infrared rays have been mainly used.

However, in these sensors, there is a blind spot because the detection range is often linear.
It has not always been possible to reliably detect the entry and exit of people. In addition, since a power source is required as a drive source for laser beams and the like, if the power source itself cannot be driven, intrusion of a person cannot be detected, and in particular, it is a serious fatal injury as a sensor for security. was there.

In this case, a conductive composition that has been conventionally used as a device such as a switch is applied to the floor surface to detect the pressure applied by the weight of the human body and detect the intrusion of a person. It can be considered as a sensor. The conductive composition as the pressure-sensitive sensor is generally formed by supporting a conductive substance such as graphite with rubber or other elastic body such as silicone rubber.

In this conventional electrically conductive composition, an elastic body carrying an electrically conductive substance is compressed in a space regulated by pressurization, resulting in a close distance between the electrically conductive substances. The pressurization is detected by detecting the "reduction" of the electric resistance value (Japanese Patent Laid-Open No. Sho 5).
9-98164, JP-A-2-186604, JP-A-3-247662, JP-A-6-300.
646, JP-A-7-50122, and JP-B-7
-87123, JP-A-8-327474,
JP-A-9-178410, JP-A-10-1063
No. 84, Japanese Patent Application Laid-Open No. 2001-153741, etc.).

[0006]

On the other hand, in recent years, this conductive composition is often installed on a floor surface or the like and used as a heating element of a floor heating device or a heating device such as a hot carpet. Specifically, a conductive polymer is supported on a heat-resistant fiber or film on which electrodes are arranged in advance, and Joule heat is generated between the electrodes by applying electric power to the electrodes to function as a heating element. is there. Therefore, it is conceivable that the conductive composition installed on the floor or the like as the heating element is also used at the same time as a pressure sensor for detecting pressure applied by the weight of a person to prevent intrusion.

However, when the elastic body is easily deformed by pressurization and the electric resistance value "decreases" like the conductive composition used as the conventional pressure sensor, the electric resistance value is changed by the change. Can be detected, on the other hand,
When focusing on the function as a heating element, for example, when a person sits on the conductive composition, or when a load is applied such as lying down, the amount of heat generated by energization increases due to a decrease in electrical resistance and As a result, the temperature rises rapidly, which may lead to abnormal heating and low temperature burns. This means that when a person, etc., rides on the heating element, the heat generated by the pressurized object such as the human body is blocked and the escape area is lost. Considering that there is a tendency for the temperature to rise, it can be said that this phenomenon is not suitable as a heating element.

For this reason, when the conductive composition is used as a heating element, it is usually rather conductive so that the electric resistance value is not easily lowered by pressurization and the calorific value is not unnecessarily increased. It has been necessary to impart a certain degree of rigidity to the binder carrying the substance in order to suppress its elastic deformation. Therefore, when a conductive composition is used as a heating element, it is difficult to function as a pressure sensor by elastically deforming the binder by pressurization to cause a decrease in electric resistance value and detecting this. It was the actual situation. That is, conventionally, it has been difficult to simultaneously use the conductive composition as a heating element and as a pressure sensor because the properties required are contradictory.

In this case, PTC (Positive Tem) is added to the conductive composition by adding paraffin or the like to the conductive composition.
It is conceivable to deal with abnormal heating by adding perature Coefficient (positive temperature coefficient) characteristics. However, this PTC characteristic is a kind of performance as a positive thermistor that converts a change in temperature into a change in the electrical resistance of the element, and the binder carrying the conductive material thermally expands as the temperature rises, causing a gap between the conductive materials. As a result of increasing the distance, the electric resistance value “increases”, and when the temperature rises to a predetermined temperature (sealing point), the electric resistance value suddenly “increases” to suppress the amount of heat generation.

Therefore, even in the heating element utilizing this PTC characteristic, usually, a conductive material is used so that the change of the electric resistance value can be appropriately controlled and the temperature can be surely controlled to a predetermined value. It is still necessary to impart a certain degree of rigidity to the binder to be carried, and in particular,
If the electric resistance value is set to “decrease” by pressurization, the “increase” of the electric resistance value due to the PTC characteristic is offset, and the temperature control function due to the PTC characteristic cannot be properly exerted. There is a fear.

In view of the above problems, the problem to be solved by the present invention is to be able to reliably detect the comings and goings of a person, and at the same time, appropriately exhibit the function as a heating element of a heating device. It is an object of the present invention to provide a pressure sensor that can be appropriately installed on a floor surface to surely meet different needs of the floor surface.

[0012]

As a first means for solving the above problems, the present invention provides a pressure sensor having a sensor body and a resistance detector for detecting the electrical resistance of the sensor body. Then, the sensor body includes a base material and a conductive polymer carried on the base material, and the conductive polymer has a conductive material and a binder carrying the conductive material, and the binder is The present invention provides a pressure sensor having an elastic modulus that displaces a distance between conductive materials so that the electric resistance of the conductive polymer increases by pressurization.

As described above, when the elastic modulus of the binder of the conductive polymer which is the sensor body is adjusted, for example, when a load is applied to the sensor body by a person sitting on the sensor body, lying down, etc. If the binder is elastically deformed to increase the distance between the conductive materials that it carries, and if the number of conductive materials per unit volume is the same and the intervals are set to be longer, the electricity flowing through the conductive material at the shortest distance will flow. As a result of the increase in the shortest distance on the road, the electric resistance value of the pressurized location increases, so the load can be detected by this increase in the electric resistance value, and it is possible to reliably detect human intrusion, etc. it can.

In particular, in this case, not only at one place such as an entrance and exit, but also on the entire floor surface where it is not possible to avoid stepping on when a person invades, etc., can be laid easily and inexpensively. Unlike a laser beam that detects linearly, it can be used as a planar pressure sensor, and since pressure is detected due to an increase in the electrical resistance value that changes due to pressure, it can detect human intrusion, etc. In order to do so, it is not necessary to energize the sensor body, so even if the sensor body is de-energized, it is possible to reliably detect the intrusion of people, and the function as a heating element exerted by energization is impaired. The amount of electricity used can be reduced at the same time as it can be detected reliably even at the required night time.

Further, it is of course possible to function as a heating element by energizing, and in this case, in particular, since the electric resistance value is increased by pressurization, for example, the heating state of the entire room is not significantly affected, and the local area is not affected. The temperature rise of the heating element itself can be suppressed as well as the appropriate temperature rise can be suppressed, so the temperature can be kept comfortable for the human body, such as a passenger, without providing a separate temperature sensor. Only when necessary, it is possible to properly control so that only the local temperature rise is suppressed, and it is possible to reliably meet the requirements as a floor heating system. can do.

As a second means for solving the above-mentioned problems, the present invention is characterized in that, in the above-mentioned first solution means, the resistance detector detects a change in the electric resistance value of the sensor body. A pressure sensor is provided.

As described above, the pressurization can be detected by simply detecting only the presence or absence of the increase in the electric resistance value due to the pressurization, and at the same time, the electric resistance value is increased only above a predetermined load. By setting the reference value so as to perform, it is possible to react only when a person invades, prevent unnecessary detection, and surely detect only when necessary.

According to the present invention, as a third means for solving the above-mentioned problems, in the first solving means, the resistance detector measures the electric resistance value of the sensor body to detect the change amount. The present invention provides a pressure sensor characterized by:

As described above, by not only measuring whether or not the electric resistance value of the sensor body has increased, but also measuring the amount of change at all times, it is possible to determine how much load is applied according to the amount of increase. It is possible to reliably detect intrusion of a person or the like.

As a fourth means for solving the above problems, the present invention provides any one of the first to third means for solving the above, wherein the conductive material is graphite, carbon black,
The present invention provides a pressure sensor characterized by being particles or powder or fine particles of a conductive material such as graphite.

As described above, in particular, when a granular material, powder or fine particles of a conductive substance such as carbon black is used as the conductive material, it is easily supported by the binder to form a conductive polymer, and the elasticity of the binder is increased. This is preferable because the distance between the conductive materials can be easily displaced by the deformation and the electric resistance value can be easily increased.

The present invention provides, as a fifth means for solving the above-mentioned problems, in any one of the first to fourth solving means, the binder is synthesized with a thermoplastic resin, a thermosetting resin or an elastomer. The present invention provides a pressure sensor, which is formed by kneading rubber and has an elastic modulus set by adjusting the content of the synthetic rubber.

As described above, by kneading the synthetic rubber into the binder, the elastic modulus of the binder can be easily adjusted to an appropriate value. In this case, as the synthetic rubber that can be used, the following can be specifically mentioned. That is, the present invention is, as a sixth means for solving the above-mentioned problems, in the fifth solving means, the synthetic rubber to be kneaded with the binder is styrene-butadiene rubber (SBR) or nitrile rubber (NBR). The present invention provides a heating element characterized by being present.

As a seventh means for solving the above problems, the present invention provides the method according to any one of the fifth and sixth solutions, wherein the weight ratio of the synthetic rubber to the entire binder is 5% to 10%. A pressure sensor is provided.

Thus, when the weight ratio of the synthetic rubber to the entire binder is set to 5% to 10%, the electric resistance value is increased by pressurizing in an appropriate range, as shown in Examples described later. The elastic modulus of the binder can be appropriately adjusted and set.

The present invention provides, as an eighth means for solving the above-mentioned problems, in any one of the first to seventh means for solving the problems, the binder is an electroconductive polymer made of an electrically conductive polymer when pressed by the weight of the human body. The present invention provides a pressure sensor having an elastic modulus that displaces a distance between conductive materials so that a resistance value increases by 10Ω or more.

As described above, when the electric resistance value is increased by a value of two digits when the load due to the weight of the human body which is generated when the person actually needs to be detected is invaded, the intrusion of the person is detected. The presence / absence can be surely determined, and at the same time, malfunction can be prevented when there is no need to sense such as a simple drop of a book or entry of a small animal such as a dog or a cat. Further, in this case, when the function as a heating element is also exerted by energization, it is possible to suppress a local temperature increase due to the pressurization. More specifically, it is preferable to set the amount of change in the elastic modulus or electric resistance of the binder within the following range.

That is, according to the present invention, as a ninth means for solving the above-mentioned problems, in any one of the above-mentioned first to eighth means, the binder has an electric resistance value of a conductive polymer of 60 kg / The present invention provides a pressure sensor having an elastic modulus that displaces a distance between conductive materials so as to increase by 20Ω or more when a pressure of 0.075 m ² is applied.

As shown in Examples described later, when the relationship with the change of the electric resistance value was actually examined, it was found that
The binder has an electric resistance value of the conductive polymer of 60 kg /
Having an elastic modulus that displaces the distance between the conductive materials so that it increases by ²⁰ Ω or more when a pressure of 0.075 m ² is applied, the intrusion of a person can be reliably detected, and a temperature of 60 ° C. or less can be detected. However, it was confirmed that the temperature control function can be activated and the temperature can be appropriately maintained at a comfortable temperature for the human body.

The present invention provides, as a tenth means for solving the above-mentioned problems, in any one of the above-mentioned first to ninth means, the base material of the sensor main body is a fiber, and the sensor main body is The present invention provides a pressure sensor characterized by being formed into a fibrous shape.

The present invention provides, as an eleventh means for solving the above-mentioned problems, in any one of the first to tenth solving means, the base material of the sensor main body is a fiber, and the sensor main body is The present invention provides a pressure sensor characterized in that the pressure sensor is formed in a planar shape from fibers carrying a conductive polymer.

As described above, when the fibrous or planar sensor main body is made of fiber as a base material, it can be easily adapted to floor heating, hot carpets and other products, and can be properly installed on the floor surface to generate a heating element. At the same time, it can be effectively used as a security sensor for preventing people from entering and a sensor for controlling opening / closing of an automatic door. In this case, in particular, the planar sensor body can be embodied by the following means.

That is, according to the present invention, as a twelfth means for solving the above-mentioned problems, in the eleventh solution means, the sensor main body has fibers carrying a conductive polymer arranged in the same direction to form a dummy. The present invention provides a pressure sensor characterized in that fibers are arranged in a direction orthogonal to fibers carrying a conductive polymer and are braided to form a plane.

As described above, if the fibrous sensor bodies having the conductive polymer are arranged in parallel, it is difficult to avoid the detection because the person is straddling the person, and the intrusion of the person can be surely detected. At the same time, it is possible to generate heat with an electric current, while arranging dummy fibers in a direction orthogonal to these sensor bodies ensures strength and shape retention as a planar sensor body, and appropriate flexibility. it can.

The present invention provides, as a thirteenth means for solving the above-mentioned problems, in any one of the above-mentioned tenth to twelfth means, the fiber as the base material of the sensor body is a hollow fiber. A characteristic pressure sensor is provided.

As described above, when the hollow fiber is used as the fiber which is the base material of the sensor body, the conductive polymer can be stably supported, so that the performance can be made constant and, at the same time, the hollow fiber can be obtained. Has a large surface area and is suitable for improving the binding force with the conductive polymer.

As a fourteenth means for solving the above-mentioned problems, the present invention is characterized in that, in any of the tenth to thirteenth means for solving the above-mentioned problems, an electrode for electrically conducting a conductive polymer is further provided. The present invention provides a pressure sensor.

As described above, when the conductive polymer is also provided with electrodes for applying electric power, it is not only used as a mere pressure sensor but also in various heating products such as floor heating and hot carpet. Can be applied.

The present invention provides, as a fifteenth means for solving the above problems, in any one of the first to fourteenth means for solving the problems, the conductive polymer is energized by an increase in electric resistance value due to pressurization. The present invention provides a pressure sensor characterized in that the amount of heat generated by

As described above, when the amount of heat generated by energization is reduced by increasing the electric resistance value due to pressurization, it is possible to prevent local abnormal heating due to pressurization due to the weight of a person. If the body also contains a conductive polymer that also has PTC properties, the PT is generally
The temperature can be appropriately controlled even at a temperature of 60 ° C. or lower at which the C characteristic is exhibited.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a pressure sensor 10 of the present invention, and the pressure sensor 10 has a structure as shown in FIG. In addition, the sensor body 12 and the resistance detector 14 for detecting the electric resistance of the sensor body 12 are provided. As shown in FIG. 2, the sensor body 12 particularly includes a base material 16 and a conductive polymer 18 carried on the base material 16.

As the base material 16, it is preferable to use a fibrous material as shown in FIG. As a result, the sensor body 12 can be formed into a fibrous shape as shown in FIG. 2, and the fibrous sensor body 12 is processed into a planar pressure sensor 10 as shown in FIG. ,
For example, it can be easily adapted to products that need to detect pressure in a wide area, such as mats, floor heating systems, and hot carpets, to detect people entering and exiting, and can be laid easily and inexpensively on the entire floor surface. can do.

The fibrous base material 16 is not particularly limited as long as it can properly carry the conductive polymer 18, and specifically, for example, cotton, polyester fiber, polyamide fiber, acrylic resin. Synthetic fibers such as type fibers and vinylon type fibers, or spun fibers or mixed fibers thereof may be used, and in particular, as shown in FIG.
When the hollow fiber is used, the conductive polymer 18 can be stably supported, so that the performance can be made constant, and at the same time, since the hollow fiber has a large surface area, the binding force with the conductive polymer 18 is improved. It is suitable for the purpose.

As shown in FIG. 2, the conductive polymer 18 has at least a conductive material 20 and a binder 22 carrying the conductive material 20. With such a conductive polymer 18, a binder 2 described later
There is no particular limitation on the basic constitution except the characteristic of the elastic modulus of 2, and the constitution and the material thereof are almost the same as those of the conductive composition conventionally used as a heating element of a floor heating device or the like. Various materials can be used, and it is not precluded that paraffin or the like can be added at the same time to exhibit PTC characteristics, but specific examples include the following. it can.

As the conductive material 20, for example, graphite,
Granules or powders or particles of carbon black, graphite, metals or mixtures thereof and other electrically conductive substances can be used. As described above, when the particles, the powder or the fine particles are used, it is easy to support the binder 22 to form the conductive polymer 18, and it is easy to displace the distance between the conductive materials 20 by elastic deformation of the binder 22 described later. It is suitable for easily increasing the electric resistance value.

Further, the binder 22 can use a thermoplastic resin, a thermosetting resin or an elastomer as a main component. More specifically, examples of such a thermosetting resin include modified ethylene terephthalate and the like, and examples of the elastomer include butadiene and isoprene. However, in the present invention, as described below, a binder is used. It is necessary to adjust 22 to an appropriate elastic modulus, and it is particularly desirable to use a thermoplastic elastomer (TPE) as an appropriate material for ensuring this high elastic modulus.

Specifically, in the present invention, the binder 22
Has an elastic modulus that displaces the distance between the conductive materials 20 so that the electrical resistance value of the conductive polymer 18 is increased by pressurization. That is, the binder 22 is appropriately applied by pressurization.
As a result of elastic deformation of the conductive materials 20, the distance between the conductive materials 20 is widened, and the number of conductive materials 20 per unit volume is the same and the intervals are expanded. As a result, the path of electricity that propagates through the conductive material 20 at the shortest distance and flows. Since the shortest distance of is increased, only the electric resistance value of the pressed portion is increased. Therefore, the load can be detected by detecting the increase in the electric resistance value by the resistance detector 14, and the intrusion of a person can be surely detected.

In this case, the amount of increase in the electric resistance value of the conductive polymer 18 due to the pressurization is, specifically, a pressurization of about the weight of the human body which is required to detect the entrance and exit of a person. In the loaded state, it is increased by a double digit, which is not exhibited by a conductive polymer that exhibits a general PTC characteristic that has been often laid as a heating element on the floor, that is, by 10Ω or more. Conductive material 2
It is desirable that the elastic modulus is such that the distance between 0 is displaced.
As a result, it is possible to clearly grasp the increase in the electric resistance value and reliably determine whether or not a person has entered, and at the same time, for example, malfunction may occur when it is not necessary to simply sense the fall of a book. Can be prevented.

Further, the conductive polymer 18 can also function as a heating element for a heating device or the like installed on the floor surface by energization, but the amount of heat generation also decreases due to the increase in the electric resistance value due to this pressurization. To be controlled. For this reason, when the function as a heating element is also exerted by energization, for example, only a local temperature rise due to the pressurization is suppressed without giving a large amount of Eiko hot water to the heating state of the entire room. You can Specifically, for example, only when it is necessary to maintain a comfortable temperature such as a person sitting on the sensor body 12 or lying down on the sensor body 12, it is possible to increase the temperature of the local area without providing a separate temperature sensor. Can be appropriately controlled so as to be suppressed. Further, even when furniture is installed on the sensor body 12, the amount of heat generated is suppressed and the temperature does not unnecessarily rise. Therefore,
We can surely meet the demand as a floor heating system,
As well as being able to reliably detect people coming in and going out, it also properly functions as a heating element of the heating device, ensuring that it can be properly installed on the floor to meet the different needs of the floor. can do.

In this case, in particular, if the electric resistance value is set to increase by 10 Ω or more due to pressurization by the weight of the human body, the temperature control based on the PTC characteristic cannot achieve 60.
Even at a comfortable temperature below ℃ (the minimum sealing point that can be actually secured), the temperature control function can be activated to maintain an appropriate temperature. In addition, in this binder 22,
When the sensor body 12 is formed from the conductive polymer 18 which also has PTC characteristics by adding paraffin or the like,
When the temperature rises to about 60 ° C., the temperature control function by this PTC characteristic can also be exhibited.

As described above, in order to adjust the elastic modulus of the binder 22 so that the electric resistance value is appropriately increased by pressurization, specifically, the binder 22 is made of a thermoplastic resin or a thermosetting resin. Alternatively, the elastomer can be formed by kneading synthetic rubber into the elastomer, and the elastic modulus can be set by adjusting the content of the synthetic rubber to deal with it. As a result, the elastic modulus of the binder 22 is not too soft as compared with the conventional conductive composition used as a general pressure sensor, while the elastic modulus of the binder 22 is less than that of the conventional conductive composition used as a heating element. It is easily adjusted to an appropriate value that is not too hard, and pressure applied by the weight of the human body that needs to be detected causes appropriate elastic deformation such that the distance between the conductive materials 20 increases and the electrical resistance value increases. Can be set as:

Specific examples of the synthetic rubber to be kneaded include styrene-butadiene rubber and nitrile rubber, and the binder 22 is a polyolefin, polyamide, polyurethane or polyester in which these synthetic rubbers are kneaded. It can be dealt with by forming it from a thermoplastic elastomer (TPE) whose main component is a resin or the like.

In this case, regarding the proper content of the synthetic rubber, considering the embodiment of the present invention in which an appropriate increase in the electrical resistance value, which will be described later, could be confirmed, the weight ratio of the synthetic rubber to the entire binder 22 is considered. It is considered desirable to be 5% to 10%. Thereby, the elastic modulus of the binder 22 can be appropriately adjusted and set so that the electric resistance value is increased by the pressurization in an appropriate range.

The sensor body 12 used in the present invention having the above-mentioned structure is not particularly limited in its manufacturing method, but the following manufacturing method can be given as an example. Specifically, (1) 40 ° C. to 60 ° C., in which an aromatic solvent such as xylene is injected into a heated stirring container and the mixture is stirred.
(2) A conductive material 2 to which a resin or elastomer to serve as the binder 22 is added later in this solvent.
0 in an appropriate amount, preferably 25 to 40% by weight, followed by stirring, and further adding (3) PT
When imparting the C characteristic, 25% by weight to 40% by weight of paraffin is added to the conductive material 20 to be added later as a substance imparting the PTC characteristic, and stirring is performed until all solids are dissolved. (4) The fine powdery conductive material 20 is added and stirred until a uniform paste is obtained, and (5) the fine powdery conductive material 20 is dispersed substantially uniformly. The conductive polymer 18 can be obtained by kneading until it is heated (US Pat.
556, 576, etc.).

As the synthetic rubber for imparting a high elastic modulus to the binder 22, a thermoplastic plastic elastomer containing synthetic rubber is usually used in advance, and this is added to a solvent to form the binder 22. However, it can be added to the solvent together with the resin or elastomer that is the main component of the binder 22. After that, the conductive polymer 18 is impregnated with the hollow fiber that is the base material 16, and the heating element 10 can be obtained through the steps of drying and heating.

As shown in FIG. 1, the resistance detector 14 is connected to the sensor body 12 and detects an increase in the electric resistance value due to pressurization of the sensor body 12. In this case, the resistance detector 14 can be set so as to detect a change (increase) in the electric resistance value of the sensor body 12. That is, it can be set to detect the pressurization by reacting only when the electric resistance value of the sensor body 12 increases due to the pressurization. Thus, specifically, for example, by setting the reference value so that the electrical resistance value of the sensor body 12 increases only when the load is equal to or more than a predetermined load, or as described above, for example, the resistance detector. By setting 14 so that it reacts only when there is an electric resistance value of 10 Ω or more, it reacts only when there is a person's intrusion, and unnecessary detection is prevented when necessary. Only can be reliably detected.

However, the operation of the resistance detector 14 is not always required if the increase in the electric resistance value can be surely detected.
The present invention is not limited to the above-mentioned form, but can take other appropriate forms. Specifically, for example, the resistance detector 14 may be set to measure the electric resistance value of the sensor body 12 to detect the amount of change. That is, not only whether or not the electrical resistance value of the sensor main body 12 is increased, but by constantly measuring the amount of change, it is possible to determine how much load is applied according to the amount of increase. An intrusion or the like can be reliably detected. Also by this, it is possible to prevent erroneous trials and reliably prevent human detection by determining what kind of load is applied according to the measured increase amount.

As described above, as a result of being able to appropriately detect a predetermined pressure, by installing the pressure sensor 10 of the present invention on the entire floor surface, not only at one place such as an entrance and exit, but also Unlike a laser beam that detects linearly,
Since it is possible to detect the intrusion of a person on the entire floor surface that cannot be stepped on when a person intrudes, it is possible to reliably detect the intrusion of a person.

In addition, since the pressurization is detected by the increase of the electric resistance value which changes due to the pressurization, it is not necessary to energize the sensor main body 12 to detect the intrusion of a person. Even if the power supply to 12 is cut off, it is possible to reliably detect a person's intrusion and the like, and at the same time, it is possible to surely detect even at night when the function as a heating element to be exhibited by the power supply is unnecessary. It is also possible to reduce the amount of electricity used.

Further, by connecting an alarm device (not shown) or an alarm device (not shown) to the resistance detector 14, it is possible to more surely prevent illegal intrusion and other crimes. In addition, by setting such that the operation of the alarm device and the alarm device can be turned on and off, for example, when a person is staying inside the house and it is not always necessary to check for illegal intrusion, In the case of also functioning as a heating element, it is possible to set to turn off the means for warning and reporting.

Further, since the pressure sensor 10 of the present invention can reliably detect the comings and goings of a person, it can be used not only as such a sensor for security but also in a wide range of applications. For example, it can be used as a sensor for controlling opening and closing of an automatic door.

[0062]

EXAMPLE An example of the pressure sensor 10 of the present invention will be described with reference to FIG. Specifically, a cotton thread is used as the base material 16, and the conductive polymer 18 having the binder 22 having an appropriate elastic modulus is carried on the base material 16 to form the fibrous sensor main body 12. As shown in FIG. 1, the main body 12 is arranged in the same direction, and a normal dummy fiber 24 made of cotton yarn (see the alternate long and short dash line in FIG. 1) is orthogonal to the fibrous sensor main body 12 carrying the conductive polymer 18. Arranged in the direction and braided vertically 3
It was formed in a plane shape of 0 cm and 20 cm in width.

Further, as shown in FIG. 1, electrodes 26 are provided on both ends of the plurality of fibrous sensor bodies 12 arranged in parallel.
And the resistance detector 14 capable of measuring the amount of change in the electrical resistance value is connected to the electrode 26 via the connection terminal 28 and the lead wire 30 connected to the connection terminal 28. And In this case, as shown in FIG. 1, the lead wire 30 is further connected to an AC power source 32 of 100 V for energizing the electrodes 26 (setting similar to a normal outlet) so that the conductivity between the electrodes 26 is increased. The fibrous sensor main body 12 carrying the polymer 18 is energized to generate Joule heat, and a function as a heating element applicable to a heating device such as a floor heating device or a hot carpet is also added.

In this case, the conductive polymer 18 is (1)
As an elastomer to serve as the binder 22, a resin-
1 is 10% by weight ratio to the whole substance for forming the conductive polymer 18 (hereinafter, the same in this embodiment),
In addition, an elastomer containing 5% of resin-2 for adjusting the rigidity is used, xylene 40% and MIBK10.
%, While (2) adding 27% of paraffin for imparting PTC characteristics and further stirring, (3) adding 5% of carbon black fine powder as the conductive material 20 Stir to produce. In this case, as a synthetic rubber for imparting a high elastic modulus, SBR was further contained in an amount of 3%.

In the pressure sensor 10 of such an embodiment, first, its electric resistance value was measured and found to be room temperature 25.
It was 660Ω at ° C. When the pressure sensor 10 of this example was energized, it generated heat with a heat generation amount of 250 w / m ² . Based on this initial value, when a pressure of 60 kg / 0.075 m ² is applied on the pressure sensor 10 of the embodiment of the present invention shown in FIG. 1, the electric resistance value increases in the range of 20 to 50 Ω. It was confirmed that by increasing the electric resistance value within this range, the pressurization could be clearly detected, and at the same time, it was possible to control the temperature to a comfortable temperature without feeling overheating.

Therefore, if the elastic modulus of the binder 22 is adjusted so that the electrical resistance value increases by 20 Ω or more at a pressure of 60 kg / 0.075 m ² which is a pressure applied by the weight of a person, It was confirmed that the intrusion can be reliably detected, and at the same time, the temperature control function can be activated at a temperature lower than 60 ° C., preferably near body temperature.

Also, in this case, in this embodiment, after the solvent (xylene and MIBK), which accounted for 50% by weight of the total weight of the substances for forming the conductive polymer 18, was volatilized, resin 1 (10%) was used. The resin 22 (5% by weight), paraffin (27% by weight) and SBR (3% by weight) formed in a binder 22 (45% by weight based on the total weight of the material for composing the conductive polymer 18) is also electrically conductive. Since SBR (synthetic rubber) is contained in an amount of 3% by weight based on the total weight of the substance for forming the water-soluble polymer 18, this is converted into a weight ratio based on the entire binder 22 (3% out of 45%). That is, the synthetic rubber contained about 6.6% by weight of the total amount of the binder 22. Therefore, as in the above-described embodiment, the elastic modulus of the binder 22 suitable for obtaining an increase in the electric resistance value is also set by adding about 6.6% by weight of the synthetic rubber to the entire binder 22, 5% before and after that because an elastic modulus of an appropriate value could be added to the detection of pressure and temperature control.
It is considered that by mixing the synthetic rubber within the range of 10% (weight ratio with respect to the entire binder 22), it is possible to detect the intrusion of a person and control at a temperature comfortable to the human body.

[0068]

According to the present invention, as described above, the elastic modulus of the binder of the conductive polymer, which is the sensor body, is adjusted so that the electrical resistance value increases by pressurization. The load can be detected by the increase of
There is a real benefit of being able to reliably detect intrusion of people.

In particular, according to the present invention, as described above, not only at one place such as the entrance and exit, but easily and inexpensively over the entire floor surface where it is impossible to avoid stepping on when a person invades. Since it can be laid, and unlike a laser beam or the like which is detected linearly, it can be a planar pressure sensor, so that intrusion of a person or the like can be reliably detected.

Further, according to the present invention, as described above, since the pressurization is detected by the increase of the electric resistance value which changes with the pressurization, the sensor main body is detected in order to detect the intrusion of a person or the like. Since it does not need to be energized, it is possible to reliably detect human intrusion even if the sensor body is de-energized, and it is also reliable at night when the function as a heating element that is activated by energization is unnecessary. There is also a real benefit that the amount of electricity used can be reduced at the same time that it can be detected.

Further, according to the present invention, as described above, it can be made to function as a heating element by energization, and in this case, in particular, since the electric resistance value is increased by pressurization, for example, in a room. It is possible to appropriately suppress only the local temperature rise without significantly affecting the overall heating state and the like, and since the calorific value of the heating element itself is suppressed, there is no need to provide a separate temperature sensor or the like. Only when it is necessary to maintain a comfortable temperature for the human body, such as when a person is riding, it is possible to appropriately control so that only the temperature rise of the local part is suppressed, and it is possible to meet the demand as a floor heating device. Since it can respond surely, there is a real advantage that it can be properly installed on the floor surface.

According to the present invention, as described above, it is possible to detect the pressurization at the same time by detecting the presence or absence of the increase in the electric resistance value due to the pressurization by the resistance detector. By setting the reference value so that this electric resistance value increases only when the load is more than a predetermined value, it reacts only when there is a person intruding, preventing unnecessary detection and ensuring only when necessary. There is a real benefit that can be detected.

According to the present invention, as described above, the resistance detector constantly measures not only the presence or absence of an increase in the electric resistance value of the sensor body, but also the change amount. By determining whether or not a certain amount of load has been applied, there is the practical benefit of being able to reliably detect intrusion of a person or the like.

According to the present invention, as described above, since the granular material, powder or fine particles of the conductive material such as carbon black is used as the conductive material, the conductive material is supported by the binder to make the conductive material. In addition to being easily formed as a polymer, the distance between the conductive materials can be easily displaced by elastic deformation of the binder, and the electrical resistance value can be easily increased.

According to the present invention, as described above, the binder is formed by kneading a thermoplastic resin, a thermosetting resin or an elastomer with a synthetic rubber such as SBR or NBR,
Since the elastic modulus is set by adjusting the content of the synthetic rubber, there is a practical benefit that the elastic modulus of the binder can be easily adjusted.

According to the present invention, as described above, the weight ratio of the synthetic rubber to the entire binder is set to 5% to 10%, so that the electric resistance value is increased by pressurizing in an appropriate range. Easy and appropriate adjustment of the elastic modulus of the binder,
Can be set.

According to the present invention, as described above, when a load due to the weight of the human body that is generated when a person who actually needs to be detected intrudes is applied, the electric resistance value is increased by a value of two digits. Therefore, it is possible to surely determine whether or not a person has invaded, and at the same time, for example, a mere drop of a book or a dog,
There is a practical benefit that it is possible to prevent malfunctions when there is no need to respond to the entry of small animals such as cats.

At the same time, according to the present invention, as described above,
When the load due to the weight of the human body, which actually requires temperature control, is applied, the electrical resistance value is increased by a value in the double digits, so the local temperature rise due to the pressurization can be suppressed. There is.

According to the present invention, as described above, the binder has an electric resistance of the conductive polymer of 60 kg / 0.07.
Since it has an elastic modulus that displaces the distance between conductive materials so that it increases by 20 Ω or more when a pressure of 5 m ² is applied, it is possible to reliably detect human intrusion, and even at a temperature of 60 ° C. or less, The control function can be activated, and there is a practical benefit of being able to properly maintain a temperature that is comfortable for the human body.

According to the present invention, as described above, when the fiber is used as the substrate and the fibrous or planar sensor body is used, it can be easily adapted to floor heating, hot carpets and other products.
It can be properly installed on the floor and can function as a heating element, and at the same time, it can be effectively used as a security sensor to prevent people from entering and a sensor to control opening and closing of automatic doors. is there.

According to the present invention, as described above, since the fibrous heating elements having the conductive polymer are arranged in parallel, it is difficult for a person to straddle the detection to avoid the detection reliably. In addition to being able to detect the intrusion of heat, it can also generate heat with an electric current, while dummy fibers are arranged in a direction orthogonal to these heating elements, so that the shape retention as a strength or planar heating element is maintained. There is a real benefit of ensuring the flexibility and proper flexibility.

According to the present invention, since the hollow fiber is used as the fiber as the base material as described above, the conductive polymer can be stably supported, so that the performance can be kept constant. At the same time, since the hollow fiber has a large surface area, there is a practical advantage that the binding force with the conductive polymer can be improved.

According to the present invention, as described above, since the conductive polymer is also provided with the electrodes for applying electric power, it is not only used as a mere pressure sensor, but is actually used for various purposes such as floor heating and hot carpet. There are practical benefits that can be applied to various warming products.

According to the present invention, as described above, the amount of heat generated by energization is reduced by the increase in the electric resistance value due to the pressurization. In particular, when the sensor body contains a conductive polymer that also has PTC characteristics at the same time, the temperature can be appropriately controlled even at a temperature of 60 ° C. or lower at which the PTC characteristics are generally exhibited. There is.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a planar pressure sensor of the present invention.

FIG. 2 is a schematic vertical sectional view of a fibrous sensor body used in the present invention.

[Explanation of symbols]

10 Pressure sensor 12 Sensor body 14 Resistance detector 16 Base material 18 Conductive polymer 20 Conductive material 22 binder 24 dummy fiber 26 electrodes 28 connection terminals 30 lead wires 32 AC power supply

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 3/14 H05B 3/14 FF term (reference) 3K092 PP20 QA05 QB08 QB09 QB19 QB26 UA12 UA19 VV23 VV40 3L072 AA01 AB04 AC02 AD19 AE04 AF07 AF11 AG02 4M112 AA01 BA01 CA41 CA47 CA59 EA01 EA11 EA14 5C084 AA02 AA07 AA13 BB04 CC17 DD01 DD77 EE01 EE04 5E030 AA20 BA06 BA29 CA06

Claims (15)

[Claims] 1. A pressure sensor comprising a sensor body and a resistance detector for detecting the electrical resistance of the sensor body,
The sensor body includes a base material and a conductive polymer carried on the base material, the conductive polymer has a conductive material and a binder carrying the conductive material, the binder is a pressure A pressure sensor having an elastic modulus that displaces the distance between the conductive materials so that the electric resistance of the conductive polymer increases. 2. The pressure sensor according to claim 1, wherein the resistance detector detects a change in an electric resistance value of the sensor body. 3. The pressure sensor according to claim 1, wherein the resistance detector detects an amount of change by measuring an electric resistance value of the sensor body. 4. The pressure sensor according to any one of claims 1 to 3, wherein the conductive material is graphite.
A pressure sensor characterized by being particles, powder or fine particles of a conductive substance such as carbon black, graphite or the like. 5. The pressure sensor according to any one of claims 1 to 4, wherein the binder is formed by kneading a synthetic rubber with a thermoplastic resin, a thermosetting resin, or an elastomer. The pressure sensor, wherein the elastic modulus is set by adjusting the content of the synthetic rubber. 6. The pressure sensor according to claim 5, wherein the synthetic rubber kneaded with the binder is styrene butadiene rubber or nitrile rubber. 7. The pressure sensor according to claim 5, wherein the weight ratio of the synthetic rubber to the entire binder is 5% to 10%. Pressure sensor. 8. The pressure sensor according to claim 1, wherein the binder increases the electrical resistance value of the conductive polymer by 10Ω or more due to the pressure applied by the weight of the human body. A pressure sensor having an elastic modulus that displaces the distance between the conductive materials. 9. The pressure sensor according to claim 1, wherein the binder has an electric resistance of the conductive polymer of 60 Ω / 0.075 m ^{2 and} a pressure of 20 Ω. A pressure sensor having an elastic modulus that displaces the distance between the conductive materials so as to increase as described above. 10. The pressure sensor according to claim 1, wherein the base material of the sensor body is a fiber, and the sensor body is formed in a fibrous shape. A pressure sensor characterized by. 11. The pressure sensor according to claim 1, wherein the base material of the sensor body is a fiber, and the sensor body carries the conductive polymer. A pressure sensor, which is formed in a planar shape from fibers. 12. The pressure sensor according to claim 11, wherein the sensor main body has the fibers carrying the conductive polymer arranged in the same direction, and dummy fibers carrying the conductive polymer. A pressure sensor, wherein the pressure sensor is arranged in a direction orthogonal to the fibers and formed into a planar shape by braiding. 13. The pressure sensor according to claim 10, wherein the fiber that is the base material of the sensor body is a hollow fiber. 14. The pressure sensor according to claim 10, further comprising an electrode that conducts electricity to the conductive polymer. 15. The pressure sensor according to any one of claims 1 to 14, wherein the conductive polymer has a reduced amount of heat generated by energization due to an increase in electric resistance value due to the pressurization. A pressure sensor characterized by.