JP2835949B2 - Safety device for carbon surface heating element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrical safety device used for a carbon surface heating element.

[0002]

2. Description of the Related Art A carbon surface heating element B provided with power supply electrode strips A, A along both side edges conventionally employs a thermostat C as shown in FIG.
, Or thermofuses D are connected to the power supply lines E, E to the electrode bands A, A, and are arranged so as to be even with respect to the surface of the surface heating element B, or as shown in FIG. As described above, the thermo-wire sensor F is meanderingly arranged on the surface of the surface heating element B and controlled by the controller.

[0003] However, these conventional temperature control methods are:
In any case, there is a risk that local overheating will not be perfect and could lead to a burn accident.

[0004] Further, in this kind of surface heating element, since electricity flows continuously from one electrode band A to the other electrode band A over the entire surface of the carbon heating surface b, cracks are formed in the carbon surface b. When the electrode strip A is cut, the arc generation due to the short circuit is greater than that of the wire heater, and the crack ends c and c and the cut side d of the electrode strip are overheated due to current concentration. There is a danger of ignition.

[0005] Therefore, a good conductive film is provided on the outer surface of the electrical insulation of the carbon surface heating element, and when the carbon heating surface is cracked or the electrode band is cut, the carbon heating surface is cut off from the carbon heating surface. The leaked electricity is received by the good conductive film to excite the coil, and power is supplied to the carbon-surface heating element. By opening the relay switch interposed in the input wire, the electricity to the carbon-surface heating element is released. A safety device was designed to stop the supply of water.

[0006] However, the carbon surface heating element is bent or bent due to the electric insulation structure in which the carbon heating surface obtained by applying a carbon paint to a cloth in which the electrode band is woven is integrally bonded with a vinyl chloride film. Although no abnormalities such as cracks occur on the heat generating surface of the carbon in response to repeated pressing, cracks easily occur in the electrical insulation part at an early stage, which may cause a safety device to work and shorten the life of the product significantly. .

[0007]

Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, and its object is to eliminate any problem such as local overheating, cracking of the heating surface, or cutting of the electrode strip. In the case of a carbon surface heating element which is designed to prevent the danger of ignition which may occur by shutting off the power supply, it is possible to extend the life of the product without impairing these essential functions. Car that can be
An object of the present invention is to provide a safety device for a bon surface heating element.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. In the drawing, reference numeral 1 denotes a carbon surface heating element, which is, for example, a table of a carbon heating surface obtained by applying a carbon paint to a cloth provided by weaving power supply electrode bands 2 and 2 along both side edges. On the back surface, electric insulating sheets 3 and 3 such as a vinyl chloride sheet are integrally adhered.

[0009] A good conductive film 4 is attached to the outer surface of one side of the electric insulating sheets 3 and 3 of the carbon surface heating element 1 thus constructed. It is formed by applying a carbon paint to the inner surface of a vinyl chloride film, and is glued to the carbon surface heating element 1 at the peripheral edge as in a bag.

[0010] Good conductive film 4 glued at the periphery
A flexible and thin auxiliary vinyl chloride film 5 having a thickness of about 200 microns is provided on the inner surface of the auxiliary vinyl chloride film so that the surface coated with the carbon conductive paint is included in the auxiliary vinyl chloride film. The bonding of the film 5 to the carbon-surface heating element 1 is performed by spot bonding at the four corners and the center or by line bonding at the side edges.
Is as free as possible.

[0011] However, from the good conductive film 4,
The lead wire 6 is drawn out and connected to the coil 8, and the coil 8 is linked with the relay switch 7, and the other end is connected to each pole of the power supply lead wires 10 and 10 via the diodes 9 and 9. ing. The relay switch 7 is installed on the power supply lead wires 10, 10 on the side of the power supply electrode bands 2, 2 of the carbon surface heating element 1.

Reference numeral 11 denotes a capacitor, 13 denotes a diode for preventing malfunction, 14 denotes a diode, and 15 denotes a resistor.

[0013]

[Operation] The safety device constructed as described above should
A cushion, a folded blanket, or the like having a large amount of heat is placed on a local portion of the bon surface heating element 1 and is overheated without the operation of a thermostat or a sensor wire. , The good conductive film 4 receives a leakage current from the carbon-surface heating element 1,
This current excites the coil 8, opens the relay switch 7, cuts off the power supply to the carbon-surface heating element 1, and can prevent an accident without causing a fire.

Also, when a crack is formed on the carbon heat generating surface, or when the electrode strips 2 and 2 are cut and short-circuited to generate an arc, electricity leaks to the good conductive film 4. As a result, the coil 8 is excited as described above, the relay switch 7 is opened, and the power supply to the carbon-surface heating element 1 is cut off to prevent a fire accident.

However, the provision of the auxiliary vinyl chloride film 5 between the carbon-surface heating element 1 and the good conductive film 4 does not actually cause a crack on the carbon heating surface, When only the electric insulating sheets 3 and 3 are cracked, the leakage current does not flow through the good conductive film 4 and the power supply is not cut off.

Therefore, the leakage current does not flow through the good conductive film 4 when only the electric insulation sheets 3 and 3 are cracked, not the electric damage of the carbon heating element 1 itself. With the cracks in the insulation sheets 3 and 3, the surface safety device does not operate and the normal function can be maintained.

On the other hand, since the auxiliary vinyl chloride film 5 is flexible and extremely thin, about 200 microns, there is no change in impedance due to its provision, and the performance as a safety device for the good conductive film 4 is reduced. There is no.

[0018]

As described above, according to the present invention, when the carbon surface heating element is locally overheated due to the heat of the body, when the electrode band is cut and short-circuited, or when the carbon heating surface is heated. When a short circuit occurs due to a crack, the coil is excited by the leakage current to open the relay switch and cut off the power to the heating element.
It is possible to prevent a burnout accident due to overheating and a short-circuited arc, and to use it safely.

Further, a flexible and thin auxiliary vinyl chloride film is freely bonded between the good conductive film and the carbon surface heating element to the electrically insulating sheet 3 of the carbon surface heating element by point bonding or wire bonding. The safety device does not work even if the insulation sheet on the heat generating surface of the carbon is cracked, so that the product life can be maintained for a long time. Does not decrease.

Since the auxiliary vinyl chloride film is provided with a degree of freedom without being fixed to the entire surface of the carbon-side heating element, cracks are less likely to be caused by repeated bending and pressing, so that the life of the product can be further extended. Can be measured.

The good conductive film or auxiliary vinyl chloride film coated with carbon does not block the far infrared rays emitted from the heating element on the carbon surface and does not deteriorate its performance.

In the case where the temperature sensing line F is provided as shown in FIG. 6, the signal to the controller 12 is cut off as shown in FIG. 4 to supply power to the carbon surface heating element. Can also achieve the purpose of the safety device.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view of a carbon surface heating element provided with a safety device according to the present invention.

FIG. 2 is a perspective view of a carbon surface heating element provided with a safety device according to the present invention.

FIG. 3 is an electric circuit diagram of the present invention.

FIG. 4 is a circuit diagram according to another embodiment of the present invention.

FIG. 5 is a perspective view for explaining a conventional method of controlling the temperature of a carbon surface heating element.

FIG. 6 is a perspective view for explaining a conventional method of controlling the temperature of a carbon surface heating element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Carbon surface heating element 2 ... Power supply electrode band 3 ... Electrical insulating sheet 4 ... Good conductive film 5 ... Auxiliary vinyl chloride film 7 ... Relay switch 8 ... Coil 9 ... Diode 12 ... Controller F ... Temperature sensing line

Continuing from the front page (72) Inventor Yoshimichi Nakamura 276-1031 Aoimachi, Hamamatsu-shi Rinishi Thermo Stock Company In-house (72) Inventor Tsukasa Matsushima 276-1031 Aoimachi Hamamatsu-shi Rinishi Thermo Stock Company In-house ( 56) References JP-A 3-12387 (JP, U) JP-A 57-22190 (JP, U) JP-A 49-5938 (JP, Y1) Registered utility model 3021203 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) H05B 3/00 365

Claims (1)

(57) [Claims] 1. A carbon-side heating element having power supply electrode strips along both side edges and electrically insulating the front and back surfaces with an insulating sheet, and one side of the insulating sheet of the carbon-side heating element. a flexible thin auxiliary vinyl chloride films adhered with substantially the entire surface to a point or linear bonding, to the inner surface of the polyvinyl chloride film mosquitoes - mosquitoes on the surface of the auxiliary vinyl chloride film by coating a carbon conductive coating - Bonn conductive coating The application surface of the auxiliary salt
Ryoden pasted so that it can be encapsulated with vinyl chloride film
An electrically conductive film , a relay switch provided in a power supply input path to the carbon surface heating element, and a relay connected to the good conductive film and connected to each pole of the power supply input path via a diode. It is composed of the relay switch coil described above, and when the heat generation temperature rises abnormally, the insulation sheet is degraded in insulation, and when the needle sticks through the conductive film, the electricity to the carbon surface heating element is conductive. The leakage current flows to the conductive film and the leakage current flows to the coil to excite the coil, and the relay switch opens to cut off the supply of electricity to the carbon surface heating element. Safety device.