JP4200184B1 - Moisture detection sensor - Google Patents

Abstract

An object of the present invention is to make it possible to determine the quality of a moisture detection sensor and to improve the accuracy of the sensor.
A circuit unit including a low-resistance conductive wire 1 and 2 extending side by side and a high-resistance conductive wire 3 connecting between ends of the low-resistance conductive wire are both waterproof and insulating. 5, the exposed hole 6 is formed in the covering body so as to expose the low-resistance conductive wire at a plurality of locations. If moisture adheres between exposed holes and short-circuits between low resistance conductors with current flowing in the circuit section, the current value will be larger than before moisture adheres. If a small current flows, the circuit is normal. When a short circuit occurs and a large current flows, it is determined that moisture is generated. Further, the portion corresponding to the exposed hole in the low resistance conductive wire is the extended portion 6a having a larger area than the exposed hole.
[Selection] Figure 1

Description

  The present invention relates to a moisture detection sensor.

  Conventionally, a moisture detection sensor that detects the presence and generation of moisture when moisture adheres between electrodes and current flows is known (see, for example, Patent Documents 1, 2, and 3). This moisture detection sensor is used for, for example, automatic wipers and diapers of automobiles.

JP-A 63-290950 JP 2000-19136 A JP 2002-82080 A

  The conventional moisture detection sensor generates a potential difference between the electrodes, and when moisture flows between the electrodes and a current flows, it outputs a signal that moisture has been generated. The quality of the included circuit cannot be determined. For this reason, although moisture adheres between the electrodes, a signal is not generated due to an electrode defect or the like, and there is a disadvantage that the generation and presence of moisture cannot be detected.

  Further, when the conventional moisture detection sensor is used for detecting urination in a diaper or the like, there is a problem that if the urination is detected a plurality of times, the resistance value changes and a malfunction is likely to occur.

  Accordingly, an object of the present invention is to provide a moisture detection sensor that can solve the above-described problems.

  In order to solve the above-mentioned problems, the invention according to claim 1 includes a low-resistance conductive wire (1, 2) extending side by side and a high-resistance conductive wire (3) connecting between the ends of the low-resistance conductive wires (1, 2). Is exposed between the carrier (4) and the cover (5), both of which are waterproof and insulating, and exposes the low resistance conductors (1, 2) at a plurality of locations. 6) is formed on the covering (5) or the carrier (4), and moisture (W) adheres between the exposed holes (6) in a state where current is passed through the circuit portion, and between the low resistance conductors (1, 2). When a short circuit occurs, the current value becomes larger than before moisture (W) adheres, and the portion corresponding to the exposed hole (6) in the low resistance conductors (1, 2) is larger than the exposed hole (6). A moisture detection sensor having an extended area (6a) having an area is employed.

  The invention according to claim 2 is the moisture detection sensor according to claim 1, wherein the low-resistance conductive wires (1, 2) and the high-resistance conductive wires (3) are printed on the film-shaped carrier (4). A moisture detection sensor having a cover (5) printed from above is employed.

  The invention according to claim 3 is the moisture detection sensor according to claim 1 or claim 2, wherein the extension (1a, 2a) of the low resistance conductor (1, 2) is provided at a location where moisture (W) tends to concentrate. ) And a moisture detection sensor in which an exposure hole (6) is formed.

  According to a fourth aspect of the present invention, in the moisture detection sensor according to any one of the first to third aspects, the moisture passage hole (9a) that penetrates between the front and back sides of the carrier (4) and the covering (5). , 9b) is employed.

  The invention according to claim 5 employs the moisture detection sensor according to claim 1, wherein the low resistance lead and the high resistance lead are printed with conductive ink containing conductive carbon.

  In this case, the printing ink of the low resistance conductive wire may contain more conductive carbon than the printing ink of the high resistance conductive wire.

  According to a seventh aspect of the present invention, in the moisture detection sensor according to the first aspect, the covering body or the support body provided with the exposed holes is formed as a laminated body of printing ink layers, and at least one of the laminated bodies. Employs a moisture detection sensor formed of urine resist ink.

  In this case, at least one layer interposed between the urine resist ink layer, the low-resistance conductive wire, and the high-resistance conductive wire in the laminate can be formed with the solvent resist ink. The urine resist ink can be a urethane bond ink of polyester polyol and isocyanate or a UV curable resin ink. The solvent resist ink can be a polyester resin ink.

  The invention according to claim 11 is the moisture detection sensor according to claim 1, wherein the low resistance lead and the high resistance lead are printed with conductive ink containing only conductive carbon as a conductive substance. adopt.

  According to the first aspect of the present invention, when a short circuit occurs between the low resistance conductors (1, 2) that run side by side when moisture (W) adheres between the exposed holes (6) in a state where an electric current is passed through the circuit portion. Since the current flowing through the circuit is increased compared to before the moisture (W) is attached, it can be used as a moisture detection sensor after confirming the quality of the circuit portion. It is possible to accurately detect the presence or absence of. Moreover, even when the low-resistance conductive wire is thin, the accuracy as the moisture detection sensor can be increased.

  According to the invention which concerns on Claim 2, a moisture detection sensor can be formed thinly, and it becomes possible to install in a narrow place, an uneven part, etc.

  According to the invention which concerns on Claim 3, the sensitivity as a moisture detection sensor can be raised.

  According to the invention of claim 4, even if moisture exists on the side opposite to the exposed hole (6), the moisture flows to the exposed hole (6) side through the moisture passage hole (9a, 9b). The presence of (W) can be properly detected.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

<Embodiment 1>
As shown in FIGS. 1 to 4, this moisture detection sensor includes a circuit portion including a low-resistance conductive wire 1, 2 that extends side by side and a high-resistance conductive wire 3 that connects between the ends of the low-resistance conductive wires 1, 2. Prepare. This circuit part is sandwiched between the waterproofing and insulating carrier 4 and the covering 5, and an exposed hole 6 is formed in the covering 5 to expose the low resistance conductors 1 and 2 at a plurality of locations. .

  The carrier 4 carries the entire moisture detection sensor and is formed in a bendable belt shape. The carrier 4 has a waterproof property so as not to allow moisture to pass therethrough, and has an insulating property so as not to pass electricity. Moreover, in order to make it easy to confirm the quality of the circuit portion, it is desirably formed transparent. The support 4 is made of a biaxially stretched film such as polypropylene, polyethylene, polyvinyl chloride, polyester, polyamide, polyimide, polyamideimide, polycarbonate, or polystyrene. The thickness of the carrier 4 is desirably 30 μm to 300 μm, and more desirably 50 μm to 100 μm.

  A plurality of low-resistance conductive wires 1 and 2 in the circuit portion are provided, and each extend in parallel along both side edges of the belt-like film that is the carrier 4. The low resistance conductive wires 1 and 2 are formed by printing on the carrier 4 using conductive ink.

  The conductive ink is made by kneading a binder, conductive metal powder, and other fillers. The binder is polyvinyl chloride resin, polyacrylic resin, epoxy resin, polyester resin, polyacrylurethane type. Resins, polyolefin resins, polyurethane resins, phenol resins, and the like can be used. As the conductive metal powder, silver, gold, copper, nickel, aluminum, conductive carbon, or the like can be used. The filler includes a viscosity modifier, a dispersant and the like. The low resistance conductive wires 1 and 2 are formed by applying the conductive ink in a thin strip shape on the carrier 4 by screen printing, direct gravure printing, flexographic printing or the like. Each of the low resistance conductive wires 1 and 2 is printed to have a width of 1 mm and a thickness of 10 μm, preferably 5 μm to 30 μm, for example. The resistance value of the low-resistance conductive wires 1 and 2 is preferably 0 to 200 kΩ, more preferably 100 kΩ or less, for example, by adjusting the content of the conductive metal powder of the conductive ink. In the first embodiment, it is set to about 100 kΩ.

  The high resistance conductive wire 3 of the circuit portion is printed by the same printing method with the conductive ink having the same composition as the conductive ink used for printing the low resistance conductive wires 1 and 2. However, the amount of the conductive metal powder contained in the conductive ink is small, and as a result, the resistance value of the high-resistance conductive wire 3 is set larger than the low-resistance conductive wires 1 and 2, for example, about several MΩ. Moreover, in order to make it easy to distinguish from the low-resistance conductive wires 1 and 2, it is formed thinner than the low-resistance conductive wires 1 and 2, for example, with a width of about 0.5 mm. Further, the high resistance conductive wire 3 extends from one end portion of one low resistance conductive wire 1 to the other end portion along the low resistance conductive wire 1, toward the other end portion of the other low resistance conductive wire 2, and this low resistance conductive wire 2. Extending to one end thereof. As a result, the high-resistance conductive wire 3 and the low-resistance conductive wires 1 and 2 are connected as a single electric wire on the carrier 4, and a certain amount is generated by forming a potential difference between the rear ends of the low-resistance conductive wires 1 and 2. Current flows. The resistance value of the high resistance conductive wire 3 is preferably set to 1 MΩ to 10 MΩ, more preferably 2 MΩ to 6 MΩ.

  Lead wires 7 and 8 are connected to the other end portions of the two low resistance conductive wires 1 and 2. The lead wires 7 and 8 are also printed on the carrier 4 with conductive ink. The conductive ink used for this is the same as the conductive ink for the low resistance conductors 1 and 2.

  In addition, the extended portions 1a and 2a of the low resistance conductive wires 1 and 2 are formed at the tip of the carrier 4, for example, where the water W tends to concentrate. Specifically, one end portion of each low resistance conducting wire 1, 2 is bent and extended to cross the carrier 4 to the opposite low resistance conducting wire 2, 1. Further, the high resistance conductive wire 3 also bends and extends along the low resistance conductive wires 1 and 2.

  The covering 5 is coated on the surface of the carrier 4 from above the circuit part, and insulates the circuit part together with the carrier 4 from the outside. Specifically, the covering 5 is formed of printing ink.

  Printing ink is made by kneading a binder, pigment, and other fillers. The binder is polyvinyl chloride resin, polyacrylic resin, epoxy resin, polyester resin, polyacrylurethane resin, polyolefin resin. Resins, polyurethane resins, phenol resins, and the like can be used. Moreover, as the binder, a polyester polyol-isocyanate bonded with urethane or a UV curable resin can be used. As the pigment, for example, a white pigment is used for easy identification from the circuit portion. The filler includes a viscosity modifier, a dispersant and the like. The printing ink is applied on the surface of the carrier 4 so as to leave the lead wires 7 and 8 from above the circuit portion by screen printing, direct gravure printing, or the like, thereby forming the covering 5. This covering 5 functions as an insulating film and a waterproof film.

  An exposure hole 6 is formed in the covering 5 to expose the low resistance conductive wires 1 and 2 at a plurality of locations. These exposed holes 6 are formed simultaneously with the printing of the covering 5. In the illustrated example, two low resistance conductors 1 and 2 extending in parallel are provided at predetermined intervals, and one or a plurality of extensions 1a and 2a of the low resistance conductors 1 and 2 are provided. Although the exposure hole 6 is circular in the illustrated example, it can be appropriately changed to other shapes such as an ellipse and a rectangle. In addition, an extended portion 6 a having a larger area than the exposure hole 6 is formed as necessary at a location on the low resistance conductive wires 1 and 2 corresponding to the exposure hole 6. Thereby, even if the position of the exposure hole 6 is slightly shifted, the low resistance conductive wires 1 and 2 can be properly exposed to the outside. When moisture W adheres so as to straddle the exposed holes 6 on the low resistance conductive wires 1 and 2, the current flows between the low resistance conductive wires 1 and 2 in a short circuit. This current value is larger than the current value in the case where no short circuit occurs, whereby the adhesion of moisture W is detected.

  The carrier 4 is formed with moisture passage holes 9 penetrating between the front and back sides. In the illustrated example, the low-resistance conductive wires 1 and 2 and the extensions 1a and 1b are formed in a substantially rectangular shape, but are formed in other shapes and forms such as a plurality of small holes. It is also possible. Thereby, even if the moisture W adheres to the cover 5 side, the moisture W passes through the moisture passage holes 9a and 9b to the exposed hole 6 and the moisture W is properly detected. .

  Next, the operation of the moisture detection sensor will be described.

  Since the circuit portion and the covering 5 of the moisture detection sensor are printed on the carrier 4 made of a transparent film with different colors of ink, the presence or absence of disconnection of the circuit portion, the presence or absence of the covering 5 is visually observed. Immediate recognition is made, and the selection of the quality of the moisture detection sensor is simplified.

  In addition, when the lead wires 7 and 8 are connected to a power source (not shown) and a voltage is applied to the circuit portion, a current flows from one low resistance conductor 1 to the other low resistance conductor 2 via the high resistance conductor 3. By detecting the presence or absence of this current, etc., it is possible to select the quality of the moisture detection sensor.

  The moisture detection sensor is attached to, for example, a car body or window glass of an automobile so that the exposure hole 6 side is exposed outside the car. Or it is stuck on a diaper. When the lead wires 7 and 8 are connected to a power source such as a battery and a voltage is applied to the circuit portion, a current flows from one low resistance conductor 1 to the other low resistance conductor 2 through the high resistance conductor 3. By detecting this current, it is determined whether or not the moisture detection sensor is normal.

  When moisture W adheres to the exposed holes 6 on the two low-resistance conductive wires 1 and 2 due to rain or the like, a current flows between the low-resistance conductive wires 1 and 2 while being short-circuited. This current value is larger than the current value when no short circuit occurs, whereby the adhesion of moisture is detected. The control unit of the automobile determines that it is raining based on the output of a signal from the moisture detection sensor, and starts the wiper. When rain stops and moisture evaporates, the current value decreases again, and the control unit stops the wiper. In the case of a diaper, if the discharged urine adheres across the exposed holes 6 on the two low resistance conductors 1 and 2, the current flows between the low resistance conductors 1 and 2 in a short circuit. Thereby, the presence or absence of urination is notified by an alarm or the like.

<Embodiment 2>
In the second embodiment, as shown in FIG. 5, the high-resistance conductive wire 10 in the circuit portion of the moisture detection sensor is formed shorter than in the first embodiment.

  Note that the same portions as those in Embodiment 1 are denoted by the same reference numerals, and redundant description is omitted.

<Embodiment 3>
In the third embodiment, as shown in FIG. 6, the high-resistance conductive wire 11 in the circuit portion of the moisture detection sensor is formed shorter than in the first and second embodiments, and one end of the two low-resistance conductive wires 1 and 2. The section extends linearly.

  In addition, the same part as the part in Embodiment 1, 2 is shown using the same code | symbol, and the overlapping description is abbreviate | omitted.

<Embodiment 4>
In the moisture sensor according to the fourth embodiment, as shown in FIG. 7, the covering 5 provided with the exposed holes 6 is formed as a laminate of printing ink layers. Specifically, it consists of three layers of printing ink, and the first solvent resist ink layer 5a is printed on the surface of the carrier 4 from above the low resistance conductors 1 and 2 and the high resistance conductor 3 of the circuit part, The urine resist ink layer 5b is printed from above, and the second solvent resist ink layer 5c is printed from above. In addition, when the layers 5a, 5b, and 5c are printed, the exposed holes 6 are simultaneously formed as non-image areas.

  As the solvent resist ink, a polyester resin ink is used. As the urine resist ink, urethane bond ink of polyester polyol and isocyanate or UV curable resin ink is used.

  When this moisture sensor is attached to the diaper, the low resistance conducting wires 1 and 2 and the high resistance conducting wire 3 are protected by the covering 5 made up of the multiple printing ink layers 5a, 5b and 5c, so that the urine is an intermediate urine. The resist ink layer 5b prevents permeation into the low resistance conductors 1 and 2 and the high resistance conductor 3, so that the resistance values of the low resistance conductors 1 and 2 and the high resistance conductor 3 in the circuit portion are prevented from changing. As a result, urination can be properly detected multiple times, and the diaper can be used over multiple urinations. Further, the penetration of components such as the solvent contained in the urine resist ink layer 5b into the circuit portion is blocked by the first solvent resist ink layer 5a, and the penetration to the opposite side of the circuit portion is caused by the second solvent resist ink layer 5c. It is interrupted by.

  In addition, the same part as the part in Embodiment 1-3 is shown using the same code | symbol, and the overlapping description is abbreviate | omitted.

<Embodiment 5>
In the moisture sensor according to the fifth embodiment, in each of the first to fourth embodiments, the low resistance conductive wires 1 and 2 and the high resistance conductive wire 3 are printed with conductive ink containing only conductive carbon as a conductive substance. Is done. Thereby, the low resistance conducting wires 1 and 2 and the high resistance conducting wire 3 exhibit higher resistance to the urine component, and the fluctuation of the resistance value is suppressed. As a result, according to this moisture sensor, urination can be repeatedly and properly detected when used for a diaper.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the above embodiment, the exposure hole is provided in the cover, but it can also be provided in the carrier. It is. Further, although the covering is provided as a printing ink layer, the covering may be formed of a film similar to the carrier.

It is a surface view of the moisture detection sensor which concerns on Embodiment 1 of this invention. It is a reverse view of a moisture detection sensor. It is a top view of a circuit part. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1. It is a top view of the circuit part of the moisture detection sensor which concerns on Embodiment 2 of this invention. It is a top view of the circuit part of the moisture detection sensor which concerns on Embodiment 3 of this invention. It is sectional drawing similar to FIG. 4 of the moisture detection sensor which concerns on Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 ... Low resistance conducting wire 1a, 2a ... Extension part 3 ... High resistance conducting wire 4 ... Carrier 5 ... Covering body 6 ... Exposed hole 6a ... Expansion part 9a, 9b ... Moisture passage hole W ... Moisture

Claims (11)

  A circuit part including a low-resistance conductive wire extending side by side and a high-resistance conductive wire connecting between the ends of the low-resistance conductive wire is sandwiched between a waterproof and insulating carrier and a covering, and has low resistance. If the exposed holes that expose the conductors at multiple locations are formed on the cover or carrier, moisture will adhere between the exposed holes while a current is passed through the circuit section, and if the low resistance conductors are short-circuited, A moisture detection sensor characterized in that a current value is increased in comparison with an extended portion having a larger area than the exposed hole in a portion corresponding to the exposed hole in the low-resistance conductive wire.   2. The moisture detection sensor according to claim 1, wherein a low-resistance conductive wire and a high-resistance conductive wire are printed on a film-like carrier, and a covering is printed thereon.   The moisture detection sensor according to claim 1 or 2, wherein an extension portion and an exposure hole of a low resistance conductive wire are formed at a tip portion of the carrier.   The moisture detection sensor according to any one of claims 1 to 3, wherein a moisture passage hole is formed in the carrier and the cover so as to penetrate between the front and back sides.   2. The moisture detection sensor according to claim 1, wherein the low resistance lead and the high resistance lead are printed with a conductive ink containing conductive carbon.   The moisture detection sensor according to claim 5, wherein the printing ink for the low resistance lead contains more conductive carbon than the printing ink for the high resistance lead.   2. The moisture detection sensor according to claim 1, wherein the covering body or the support body provided with the exposed holes is formed as a laminated body of printing ink layers, and at least one of the laminated bodies is formed of urine resist ink. Moisture detection sensor.   8. The moisture detection sensor according to claim 7, wherein at least one layer interposed between the urine resist ink layer, the low resistance lead and the high resistance lead in the laminate is formed of a solvent resist ink. Detection sensor.   8. The moisture detection sensor according to claim 7, wherein the urine resist ink is urethane bond ink of polyester polyol and isocyanate or UV curable resin ink.   The moisture detection sensor according to claim 8, wherein the solvent resist ink is a polyester resin ink.   2. The moisture detection sensor according to claim 1, wherein the low resistance lead and the high resistance lead are printed with a conductive ink containing only conductive carbon as a conductive substance.

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