JPH0321832A - Sheet type temperature sensor with electric shock preventing function - Google Patents

Abstract

PURPOSE:To use both electrodes for protection and temperature detection in common by forming a three-layered sheet by forming electrode sheets of conductive foil in contact with both surfaces of a heat sensing sheet of a high polymer heat sensing resistance body which varies in impedance with ambient temperature. CONSTITUTION:An electric carpet is formed by laminating a back ornamental material 9, a face heat generating body 8, a sheet type temperature sensor 1, and a top ornamental material 10 from the bottom to the top. The sensor 1 which contacts the entire top surface of the heat generating body 8 is constituted by forming the electrode film by bringing the electrode sheets 3 of copper foil, etc., into entire-surface contact with both the surfaces of the heat sensing sheet 2 of the high polymer heat sensing resistance body and connecting conductors 11 for impedance detection thereto. Then when a power source is connected between band-like electrodes 14 and 14, the entire surface of the electric carpet generates heat at uniform temperature by the heat generating body 8. The impedance variation of the sheet 2 under the influence of the heat generation is measured to accurately detect the two-dimensional means value of the heat generation temperature. Further, the opposite sheets 3 short- circuits in case of a pin sticking phenomenon to cause a disconnection. Consequently, both accurate temperature detection and electric shock prevention are enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sheet-like temperature sensor used as a temperature detection element of a temperature control device in a heater having a planar heating element, such as an electric carpet.

(Prior art) The lower surface of the sheet heating element (8)' is used as a temperature detection element for detecting the heat generation temperature of the sheet heating element (8)' not locally but in an average two-dimensional manner over the entire surface. It is equipped with a heat-sensitive wire α9 provided in a meandering shape, and is also superimposed on the top surface of the sheet heating element in order to cause a leakage current to flow through the pin etc. and protect from electric shock when a pin etc. pierces the heating element. The heater having the structure shown in FIG. 3, which is equipped with a protective electrode 06) made of aluminum foil or the like, is known, for example, in Japanese Utility Model Publication No. 62-303.
This is disclosed in Japanese Patent No. 05.

(Problems to be Solved by the Invention) In the conventional heater described above, the protective electrode α, which is a part of the layer of the sheet heating element made of a multilayer body, and the heat-sensitive wires α, which are arranged in a meandering pattern, are each independent of each other. Because they are separate structures, in the manufacturing process of the heating heater, separate processes are required to assemble the protective electrode α0 and the heat-sensitive wire α, which complicates the process. The problem was that the control system was also complicated because of the conflicting wiring relationships.

The present invention was developed in response to the actual situation in which conventional devices still have various problems to be solved in terms of production and cost as practical devices. The purpose of this invention is to make it possible to use both the electrode and the temperature sensing electrode, thereby simplifying the structure and streamlining production.

(Means for Solving the Problems) As is clear from the drawings shown in the embodiments of the present invention, in order to achieve the above object, the sheet-like temperature sensor according to the invention of claim 1 is capable of controlling the ambient temperature. The core is a heat-sensitive sheet (2) made of a polymer heat-sensitive resistor such as a vinyl chloride mixture whose impedance changes in response to changes in impedance, and electrode sheets (2) made of conductive foil such as argonium foil are placed on both sides of the heat-sensitive sheet (2). 3) is formed into a three-layer sheet in which the sheets are closely attached to each other, and a predetermined area that can cover the entire surface of the sheet heating element (8) is provided on the upper surface side of the sheet heating element (8) arranged two-dimensionally. and both electrode sheets (3). (
3) for impedance detection iwAQl),
Ql) are connected to each other.

Further, the invention of claim 2 provides two electrode sheets 1-(3),
The structure in which (3) has a plastic insulating layer (4) closely attached to the outer surface opposite to the surface to be adhered to the heat-sensitive sheet (2) is added to the structure of the invention of claim 1. be.

(Function) The present invention utilizes the three-dimensional three-dimensional structure of the heat-sensitive sheet +21 existing between the electrode sheets (3), (3) as a carrier of impedance for temperature detection. ) can be detected not only partially but also as an average value over the entire area.

Furthermore, the electrode sheets (3) and (3) are attached to the planar heating element (8).
Since it is spread over a flat surface that covers the entire surface of the electrode, it is possible to reliably detect the phenomenon of a resistance short circuit between the electrode sheets (3) and (3) when the needle sticks, and it has an electric shock prevention function. Demonstrate fully.

In addition, by bringing the plastic insulating layer (4) into close contact with the electrode sheets (3), (3), safety can be improved by not exposing live parts more than necessary, and the electrode sheet has high bending and friction resistance. can be provided.

(Example) Hereinafter, an example of the present invention will be described based on the accompanying drawings.

FIGS. 1 and 2 show an electric carpet according to an embodiment of the present invention, and from the bottom side, the back exterior material (9), the planar heating element (
8) A thick rectangular sheet is formed by laminating the sheet temperature sensor (1) and the front/exterior material Ql.

As the planar heating element (8), those having various known structures are selected and used, but the illustrated example uses a composite of tetrafluoroethylene resin mixed with conductive carbon powder as a raw material with 0.0.
After forming it into a sheet with a thickness of about 5 to 0.1 nm, it is vertically cut into narrow conductive tabs using a slitter machine, and this is made from synthetic resin yarn. The warp yarns are arranged alternately in the warp yarns or in a ratio of one for every several warp yarns, while the warp yarns are intertwined in a plain weave by using the above-mentioned Gakkai resin yarn α hot water for the weft yarns. A planar heating element (8) is formed by a woven heating element in which conductive tape (self) is arranged at a predetermined pitch, and a conductive thread made of copper foil thread is attached for each predetermined length of each conductive tape (self). The charged electrode Q4 is made by weaving multiple pieces of
) has been established.

A sheet-like temperature sensor (11) is attached to the entire upper surface of this sheet-like heating element (8) and fixed with an adhesive. The electrode sheet (3) and the plastic insulating layer (4) are sequentially laminated on both sides of the sheet, and the heat-sensitive sheet (2) is made of a vinyl chloride mixture, a nylon mixture, etc. It is formed into a sheet with a thickness of about 100 μm using a polymer heat-sensitive resistance material that has a negative characteristic of increasing and decreasing impedance, such as volume resistivity.

On the other hand, the electrode sheet (3) is made of conductive foil such as copper foil, aluminum foil, or tin foil, and is formed into a sheet with a thickness of about 15 μm, which is adhered to both sides of the heat-sensitive sheet (2) with a conductive adhesive. , a heat-sensitive sheet (2L (21) with an electrode film in full contact with both sides of the sheet, both electrode sheets (3)
, (3), the terminal of the conducting wire αυ for impedance detection is connected by solder to an appropriate location on the side.

Next, the plastic layer (4) is provided for electrical insulation protection and for reinforcing the folding strength of both sheets (2) and (3), so it is sufficient to perform both functions. It may be made of a single layer if it is made of a material that can exhibit a strong adhesive property, but the example shown is a polyethylene sheet (5 µm thick) with a thickness of 20 μm in order to have a strong adhesive effect on the electrode sheet [3]. ) on the adhesive side with the electrode sheet (3), and also has a polyester sheet (6) with a thickness of about 16 μm which is bonded to this polyethylene sheet (5) and has excellent folding strength. Thickness: 20μm with excellent adhesiveness and electrical insulation properties when bonded to sheet (6)
It is formed into a three-layer insulating sheet with a polyethylene sheet (7). The sheet-like temperature sensor ( ) having the structure described above and the sheet-like heating element (8) are stacked one on top of the other, and the back exterior material (9) and the front exterior material α are attached to the lower and upper surfaces thereof. The electric carpet is constructed using a sheet heating element (8).
When commercial power is applied between the charged electrodes <141 and αO at both ends of the electric carpet, the planar heating element (8) generates heat due to electricity and is distributed in a flat manner, so that the entire surface of the electric carpet generates heat at a uniform temperature. .

The impedance of the heat-sensitive sheet (2) changes due to the influence of this heat generation temperature, so both electrode sheets (3), (3+
By measuring this impedance using conductive wires αυ and αυ connected to the electric carpet, it is possible to accurately detect the two-dimensional average value of the heat generation temperature. Adjustments can be made.

However, if a push pin etc. were to pierce the carpet while using the electric carpet and come into contact with the conductive part of the sheet heating element (8 layers), the exposed part of the push pin would normally become a live part and would come into contact with the person taking the heat. However, there is a risk of electric shock.
In this example, at the same time that the push pin contacts the conductive part of the sheet-like heating element (8), the opposing electrode sheets [3], (3) of the sheet-like temperature sensor (11) are short-circuited by penetrating them. Therefore, as a result of detecting the impedance value of the heat-sensitive sheet (2) as a low resistance value due to a short circuit, the control circuit determines this state as abnormal and turns off the sheet heating element (8).
) and the power supply can be forcibly disconnected, thereby providing a safety device that prevents electric shock.

(Effects of the Invention) The sensor of the present invention having the structure and operation described above has the following effects.

The heat-sensitive sheet (2) made of a polymer heat-sensitive resistor is spread as a two-dimensional volumetric resistor and covers the entire surface of the sheet-like heating element (8). ), it is possible to accurately detect the temperature as an average temperature value for the entire surface.

Moreover, both electrode sheets are in close contact with both sides of the heat-sensitive sheet (2).
(3), (3) functions as a protective electrode corresponding to a short circuit between electrodes against the bottle-stick phenomenon, so it can also serve as an electric shock prevention, and there is no need to separately provide a control detector for this purpose. Therefore, the structure of the car vent surface heater can be simplified and a low-cost product can be provided.

[Brief explanation of drawings]

1 and 2 are a partially peeled plan view and a cross-sectional view of an electric carpet according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view of a conventional electric carpet. (1)...Sheet temperature sensor, (2)...Thermosensitive sheet, (3)...Electrode sheet, (4)...Plastic insulation layer, (8)...Planar heating element, αυ・・・Conducting wire. Procedure Nefu Seisho (voluntary) 1. Display of the incident Heikai 1 year patent application No. 157521 2. Name of the invention Sheet-like temperature sensor with electric shock prevention function 3. Relationship with the person making the amendment Patent applicant address Umeda Center Building 2-4-12 Nakazaki Nishi, Kita-ku, Osaka Name (285) Daikin Industries, Ltd. Representative Minoru Yamada 4. Agent residence: 3-9-10 Minamisenba, Chuo-ku, Osaka 5. Date of amendment order Voluntary amendment 6. Subject of amendment The scope of claims and detailed description of the invention in the specification (1) The statement of the scope of claims in the description shall be amended as shown in the attached sheet. (2) The phrase "vinyl chloride mixture, etc." in page 3, item 18 of the specification is deleted. (3) Delete "vinyl chloride mixture" on page 6, line 16 of the specification. 8. List of attached documents (1) Attached sheet (1 copy)
Paper 2. Claims 1. A thermal sheet made of a polymer thermal resistor whose impedance changes according to changes in ambient temperature (2)
It is formed into a three-layer sheet with electrode sheets (3) made of conductive foil such as aluminum foil adhered to each side of the core, and two-dimensionally arranged planar heating elements (3).
8) A conductive wire for impedance detection is arranged in parallel on the upper surface side with a predetermined area that can cover the entire surface of the sheet heating element (8), and for both the electrode sheets [3), (3). A sheet-like temperature sensor with an electric shock prevention function, characterized in that αυ and αD are connected respectively. 2. The two electrode sheets (3), (3) are heat-sensitive sheets (
2. The sheet-like temperature sensor with an electric shock prevention function according to claim 1, further comprising a plastic insulating layer (4) in close contact with the outer surface of the opposite side of the surface to which the temperature sensor is attached.

Claims (2)

[Claims] 1. The core is a heat-sensitive sheet (2) made of a polymer heat-sensitive resistor such as a vinyl chloride mixture whose impedance changes according to changes in ambient temperature, and the electrode sheet is made of conductive foil such as aluminum foil on both sides of the heat-sensitive sheet (2). (3), (
3) is formed into a three-layer sheet that is closely attached to each other,
They are arranged in parallel on the upper surface side of the two-dimensionally arranged sheet heating element (8) with a predetermined area that can cover the entire surface of the sheet heating element (8), and both the electrode sheets (3), For (3), conductor wires (11), (11) for impedance detection
A sheet-like temperature sensor with an electric shock prevention function, characterized in that the two are connected to each other. 2. Two electrode sheets (3), (3) are heat-sensitive sheets (2
2. A sheet-like temperature sensor with an electric shock prevention function according to claim 1, further comprising a plastic insulating layer (4) in close contact with the outer surface of the opposite side of the surface to which it is attached.