JP2835948B2 - 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 Conventionally, a carbon surface heating element B having power supply electrode bands A.A along both side edges is 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 thermosensor wire 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 a local overheating will not be perfect and could lead to a burn accident. Further, in this kind of surface heating element, since electricity flows from the one electrode band A to the other electrode band A over the entire surface of the carbon surface b, the carbon surface b is cracked or the electrode band A is cut. In such a case, the arc generation due to the short circuit is greater than that of the wire heater, and there is a danger of overheating due to current concentration at the crack end c, c and the cutting side d of the electrode band, leading to ignition. ing.

Accordingly, a good conductive film is provided on the outer surface of the electrically insulating body of the carbon surface heating element so that when the carbon heating surface is cracked or the electrode strip 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 cause the resistor to generate heat, and power is supplied to the carbon-side heating element. A safety device for stopping the supply of electricity has been invented.

However, the carbon surface heating element is formed by integrally bonding the carbon heating surface obtained by applying a carbon paint to a cloth in which the electrode band is woven, such as a vinyl chloride sheet. Due to the structure of electrical insulation, it is not
Even though there is no abnormality such as a crack on the heat generating surface of the bon, it is easy for cracks to 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.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the purpose of any case such as local overheating, cracking of a heating surface, or cutting of an electrode strip. In the case of a carbon surface heating element in which the danger of possible ignition may be prevented by shutting off the power supply, it is possible to extend the product life without impairing these functions. -To provide a safety device for the bon surface heating element.

[0007]

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. An electric insulating sheet 3, 3 such as a vinyl chloride sheet is integrally adhered to the back surface.

[0008] A good conductive film 4 is bonded to the outer surface of one side of the electrical 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 the vinyl chloride film, and is glued to the carbon-surface heating element 1 at the peripheral edge thereof like a bag.

[0009] 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 inside of the substrate, and the carbon conductive paint application surface is adhered to the auxiliary vinyl chloride film so as to be included in the auxiliary vinyl chloride film. 5 is bonded to the carbon-surface heating element 1 by spot bonding at the four corners and the center or by line bonding at the side edges, and is as free as possible with respect to the carbon-surface heating element 1. It is.

A lead wire 6 is drawn out of the good conductive film 4 and is connected to one end of a resistor 8 linked so as to embrace a temperature fuse 7, and the other end of the resistor 8 is connected to diodes 9,9. Are connected to the respective poles of the power supply leads 10, 10. The temperature fuse 7 is provided on the power supply lead wires 10 and 10 on the side of the power supply electrode bands 2 and 2 of the carbon surface heating element 1.

[0011]

[Operation] The safety device constructed as described above should
A seat cushion or a folded blanket with a large amount of heat was placed in a local area of the bon-surface heating element 1, and the thermostat and the sensor wire were overheated without working, and the electric insulating sheets 3 and 3 were in an insulation-degraded state. Occasionally, the good conductive film 4 receives a leakage current from the carbon-side heating element 1, and this current causes the resistor 8 to generate heat and blow the temperature fuse 7 tied as shown in FIG. An accident can be prevented beforehand without interrupting the power supply to the surface heating element 1 to cause ignition.

Also, when the carbon heat generating surface is cracked, 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. In the same manner as described above, the resistor 8 generates heat, blows the temperature fuse 7 and cuts off the power supply to the carbon-surface heating element 1, thereby preventing a fire accident.

However, the provision of the auxiliary vinyl chloride film 5 between the carbon-side heating element 1 and the good conductive film 4 actually caused a crack on the heating surface of the carbon-side heating element 1. Instead, when only the electric insulation 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 safety device does not operate and the normal function can be maintained without the electric damage of the heat generating surface of the carbon surface heat generating element 1 and the degree of cracking of the insulating sheets 3 and 3.

On the other hand, the auxiliary vinyl chloride film 5 is flexible and 2
Since it is as thin as about 00 microns, there is no change in impedance due to the provision thereof, and the performance as a safety device for the good conductive film 4 does not decrease.

[0016]

As described above, according to the present invention, when the carbon-surface heating element is locally heated by the heat of the body, when the electrode band is cut and short-circuited, or when the heating surface is cracked. When a short-circuit occurs, the resistance is heated by the leakage current, the temperature fuse is blown, and the power to the heating element is cut off. An accident can be prevented beforehand, and it can be used safely.

Further, a thin auxiliary vinyl chloride film is provided between the good conductive film and the carbon-surface heating element with respect to the electrically insulating sheet 3 of the carbon-surface heating element by means of point bonding or wire bonding to increase the degree of freedom. By having it, it can be used in a normal state without the safety device working at the degree of cracking of the insulation sheet on the carbon heating surface, so that the product life can be maintained long and the original purpose of the safety device as a safety device There is no degradation in performance.

Since the auxiliary vinyl chloride film is provided with a degree of freedom without being entirely fixed to the carbon-side heating element, cracks are unlikely to be caused by repeated bending and pressing, so that the life of the product is further extended. be able to.

The carbon-coated good conductive film and auxiliary vinyl chloride film do not deteriorate in their performance without blocking far-infrared rays emitted from the carbon-surface heating element.

In the case where the temperature sensing line F is provided as shown in FIG. 7, the controller 11 is provided as shown in FIG.
The purpose of the safety device can also be achieved by cutting off the signal to the heating device and cutting off the power supply to the carbon surface heating element.

[Brief description of the drawings]

FIG. 1 is a 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 the safety device according to the present invention.

FIG. 3 is an electric circuit diagram.

FIG. 4 is a circuit diagram according to another embodiment.

FIG. 5 is an explanatory diagram showing an example of a linked state between a resistance and a temperature fuse.

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

FIG. 7 is a perspective view for explaining a conventional method of controlling a surface heating element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Carbon surface heating element 2 ... Power supply electrode band 3 ... Electric insulating sheet 4 ... Good conductive film 5 ... Auxiliary vinyl chloride film 7 ... Temperature fuse 8 ... Resistance 9 ... Diode. 11 ... Controller F ... Temperature sensing line

Continued on the front page (72) Inventor Yoshimichi Nakamura 276-1031 Aoimachi, Hamamatsu-shi, Rishinishi Stock Company In-house (72) Inventor Tsukasa Matsushima 276-1031 Aoimachi, Hamamatsu-shi, Rishinishi Stock Company In-house ( 56) References JP-A-3-12387 (JP, U) JP-A-49-74313 (JP, U) Registered utility model 3021203 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) ) H05B 3/00 365

Claims (1)

(57) [Claims] 1. A carbon heating element having power supply electrode strips along both side edges and electrically insulating the front and back surfaces by an insulating sheet, and substantially the entire surface of one surface of the insulating sheet of the surface heating element. a flexible thin auxiliary vinyl chloride films adhered at two points or linear bonding, mosquitoes on the inner surface of the polyvinyl chloride film - mosquito Bonn conductive coating applied to the surface of the auxiliary vinyl chloride film - coating of carbon conductive coating Surface is auxiliary vinyl chloride
A good conductive film attached so as to be included in the film
And Lum, the mosquitoes - temperature provided to the power supply entrance road to the Bonn surface heating element fuse - and's, resistor and connected through a diode to each pole of the power supply entrance road connecting to the highly conductive film When the heat generation temperature rises abnormally, the insulation of the insulation sheet deteriorates, and when the needle sticks through the good conductive film, the electricity to the carbon surface heating element leaks to the good conductive film and the resistance increases. A safety device for a carbon surface heating element in which a temperature fuse is blown by interrupting a temperature fuse by a leakage current flowing through the body and the resistor generates heat.