JPS63290950A - Moisture sensor - Google Patents

Abstract

PURPOSE:To obtain a moisture sensor which can be extremely inexpensively supplied to markets by laminating electrical insulating layers integrally to both faces of an electrode net and boring through-holes for sensing moisture to this insulated electrode bodies so as to touch electrode bodies. CONSTITUTION:A pair of the electrode bodies 5, 6 are arranged of good electrical conductors in the form of a panel or net in structure and are provided in tight contact with the surfaces of an electrode holding layer 2. The electrical insulating layers 3, 4 are integrally laminated on both faces of this electrode holding layer 2 and the through-holes 7 are bored thereto to expose an optional part of the electrode pairs 5, 6 by each pair. Water drops enter the through-holes 7 and electrically short circuit a pair of the electrode bodies 5, 6 when moisture is supplied from the outside this moisture sensor. This sensor is produced as a rainfall sensor and has possible applications to automatic mechanisms to withdraw clothes rods for home use on starting of a rainfall and to extend said rods in a fine weather and also as sensors for urination and evacuation of throw-way diapers for infants or nursed old men.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to various measuring instruments and control instruments, or a moisture sensor used by being attached to a diaper bag.

[Conventional technology]

Conventionally, devices for detecting moisture utilize the phenomenon that electrical resistance, capacitance, or electromagnetic induction changes depending on the degree to which a portion of the moisture sensor contacts or absorbs moisture. The most common continuous moisture measurement method is to connect to an appropriate electrical measurement circuit, read the changes in the current flowing through the measurement circuit with an ammeter, etc., and compare and compare the measured values in advance to determine the moisture content. Currently, it is used in many moisture measuring devices and automatic control devices.

The structure of the moisture sensors used in these devices is most often one in which two parallel metal rods or metal plates are used as a pair of moisture detection electrodes, followed by two metal foils on an insulating plate. Many of them are pasted parallel to each other to form a pair of detection electrodes, and other types have similar structures to those described above.

Therefore, its uses are generally designed to detect the presence or absence of a relatively large amount of water, such as detecting the amount of water in an aquarium or the detection of floor skin water in a structure; It was limited to industrial use.

On the other hand, for the purpose of detecting trace amounts of moisture, paper or gelatin impregnated with a salt that easily absorbs moisture such as lithium chloride may be pasted between the pair of electrode bodies, or a ceramic material that easily absorbs moisture may be placed between the pair of electrode bodies. Moisture sensors have also been developed that detect changes in the equilibrium moisture content of these substances due to moisture in the air, based on changes in electrical resistance and capacitance, but all of these sensors detect extremely small changes in moisture, such as humidity. Most of them are used as sensors in measuring equipment, and they are difficult to mass produce and are naturally expensive.

[Problem that the invention seeks to solve]

Recently, research into automating various tasks related to home life has been actively conducted.

For example, water itself is the most important material element in home life, such as an automatic loading device for washing and drying when the shower comes when the family is away from home, or an automatic device for detecting wet diapers for infants and elderly people in nursing care. Therefore, there has been a strong desire to develop a moisture sensor for devices related to this that is safe, reliable, inexpensive, can be used both hard and soft, and has a small volume and thickness. In particular, when it is attached to diapers, since it is generally attached to disposable diapers, it is an important issue that it can be supplied at an extremely low cost.

The present invention was invented to meet these demands.

[Failure to solve the problem]

The structure and manufacturing method will be described in detail below with examples shown.

(a) FIG. 1 (1) is a perspective view of the moisture sensor of the present invention.

(b) (5) (6) is a pair of electrode bodies that are made of a good electrical conductor and are systematically arranged in a planar and net shape, and are generally in close contact with the surface of the electrode holding layer in (2). It is provided.

(c) (5) and (4) are electrical insulating layers integrally laminated on both sides of the electrode holding layer of (2).

) (7) is a through hole bored to expose any part of the electrode pairs (5) and (6).

As for the material used in this moisture sensor, for the electrode holding layer (2), a synthetic resin film, thin plate, or nonwoven fabric such as a vinyl, olefin, acrylic, or polyester resin film is used. The electrode holding layer (2) is often used as a reinforcing material when the electrode body is extremely thin, so it is omitted when the electrode body is thick and strong.

Next, the electrode body of % (5) (6) is made of aluminum,
Metal foils such as copper, nickel, and in some cases gold, silver, platinum, and rhodium are used, but in addition to these, organic semiconductor coatings such as conductive carbon paint are also used depending on the purpose.

(5) The electrical insulation layer in (4) is made of vinyl, olefin, acrylic, polyester, etc. with low water absorption.
A material with high electrical insulation resistance is used. In addition to laminating and laminating films and thin plates made of these materials,
For example, synthetic resin paints such as acrylic, polyester, and vinyl paints may be used instead.

Next, holes 7 for water passage or storage are punched using a punch, rotary cutter, or the like.

The moisture sensor (1) of the present invention is not limited to the example shown in the figure, and in particular, the arrangement of the electrode bodies (5) and (6) can be modified in many ways depending on the application, and the electrodes are simply a pair of yin and yang. In addition to the combination of electrodes, a multi-pole combination type of five or more electrodes is also possible, for example, by adding electrodes for a compensation circuit. The through holes (7) for moisture sensing may also have an appropriate number, size, shape,
It is formed by an array.

Depending on the application, this moisture sensor may be encapsulated with an appropriate mesh or may be exposed from the bottom with a water-impermeable material.

〔Example〕

Next, an example in which this moisture sensor is applied will be described.

Application example t An example of manufacturing a rain sensor and applying it to an automatic mechanism that takes in a household clothesline when it starts raining and sends it out when it is sunny.

In FIG. 1, a polyester film was used for the electrode holding layer (2), and the electrode bodies (5) and (6) were formed on the surface of (2) by aluminum vapor deposition.

(5) For the electrical insulation layer in (4), a large number of through holes (7) with a diameter of 1 x φ were provided at a 5% pitch on the insulated electrode body which was laminated using an acrylic resin film with good weather resistance. I made a moisture sensor for detecting rainfall with a - side of 10 ewr, attached an aluminum plate to one side as a dew pan, and attached it to the column of a clothesline outdoors with the aluminum plate facing down. When we carried out an experiment by taking a clothesline rack outside and connecting it to the electric control unit of the drive mechanism that takes in the clothesline, the resistance between the electrodes of this detector changed from about 3MΩ to about 5OKΩ shortly after drizzling rain started. The temperature rapidly decreased to below, and the electric control unit was activated and the clothesline was automatically brought under the eaves of the building.

After the rain stopped, the water in the rain sensor's through-hole evaporated and dried after a while, and the resistance between the electrodes rose again to about 5MΩ, so the clothesline was automatically moved outside the building eaves again. was brought out. Furthermore, even if a foreign object accidentally comes into contact with the top surface of this sensor outdoors under sunny weather, this device will not malfunction unless the object is a conductive liquid or a conductive powder with a maximum diameter of 1z or less. It was also revealed.

Application example 2: Disposable diapers for infants or elderly people,
An example of application as a urination and defecation sensor.

A polyester nonwoven fabric was used as the electrode holding layer in FIG. 1 (2), and electrode bodies (5) and (6) were formed on this surface by a printing method using a carbon semiconductor paint. Electrical insulation layer (5) (4
) was laminated integrally with (2) using a vinyl chloride film. The through holes (7) had a diameter of a%'φ, and were drilled in large numbers so that the moisture sensor would not prevent urine from passing through. This was attached to the center of a disposable diaper in a practical experiment.
When urine water flows through the hole for several seconds every time you urinate, conduction occurs between the electrodes, and the resistance value changes from about 3MΩ to 20 to 5.
After urinating, the disposable diaper immediately completely absorbs water, the inside of the through hole becomes empty, and electrical conduction is interrupted, so that the resistance returns to about 2 MΩ or more. This phenomenon was reliably repeated every time the patient urinated while the water absorption function of the disposable diaper continued. On the other hand, during defecation, the viscosity of the stool clogs the through hole, so if electricity is passed between the electrodes for a long time, the resistance between the electrodes when the stool becomes clogged is about 50 to 100Ω.

In other words, this moisture sensor has the function of generating a short-time current each time you urinate, and passing a continuous current for a long time during defecation, so you can not only separately detect the excretion of urine and urine with only the surface of this moisture sensor, but also detect the urination. Since it is possible to identify up to the number of times, it can be incorporated into an automatic notification system when disposable diapers are replaced. In addition, as shown in Figures 2 and 5, this moisture sensor has the exposed part of the electrode body hidden in the center of the inner wall of the through hole, so even if wet human skin comes into strong contact with the surface of this moisture sensor, it will not touch the skin. Since the device does not directly touch the electrode body, it rarely malfunctions when there is a small amount of perspiration. This is an extremely important effect not only for disposable diapers but also for use as moisture sensors that are frequently touched by animals.

Furthermore, since the electrode does not come into direct contact with human skin, there are fewer restrictions on the material of the electrode body due to concerns about the occurrence of allergies.

〔Effect of the invention〕

As mentioned above, the present invention is a moisture sensor that has a number of functions obtained through a special structure, so it can be used not only for general industrial use but also for a wide range of applications as a moisture sensor. A certain liquid, viscous body,
It can also be used for various purposes as a flow sensor for powder and granular materials. Furthermore, since it is easy to manufacture and has a structure suitable for mass production, it has the advantage of being able to be supplied to the market at an extremely low cost, making it a moisture sensor with great practical effects.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the present invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is an enlarged view of section B in FIG. 1... Moisture sensor 2... Electrode holding layer 3... Electrical insulating layer 4... Electrical insulating layer 5... Electrode body 6... Electrode body 7... Through hole

Claims (1)

[Claims] It consists of an insulated electrode body made by integrally laminating electrical insulating layers on both sides of an electrode network composed of linearly extending electrode bodies, and the insulated electrode body has a through hole for sensing moisture, which is connected to the electrode. A moisture sensor that features a hole that resembles the body.