JPH0349182A - Heating apparatus - Google Patents

Abstract

PURPOSE:To quickly heat a heating surface to a stable temperature immediately after excitation with no local abnormal overheating by connecting heating elements with a positive resistance temperature coefficient and a heating element with no positive resistance temperature coefficient in parallel, and providing control devices controlling them. CONSTITUTION:With positive-resistance temperature coefficient heating elements 12 have a high output 15KW/m<2> at the ambient temperature 20 deg.C, the temperature quickly rises when they are excited, and the quick heating property is attained. When the temperature of a heating surface becomes 45 deg.C, the excitation of heating elements 12 is stopped by a thermostat 14, and a metal resistor heating body 13 with the power output at the 200-400W/m<2> level maintains stable warmth. Heating elements 12 are self-controlled at the temperature 90 deg.C in the local heating at the initial stage of excitation or at an emergency situation such as a failure of a temperature detector of a thermostat or the like, temperature over-rise preventing devices 15 and 16 are provided, abnormal overheating, smoking and firing are prevented making this heating apparatus very safe.

Description

[Detailed description of the invention] Industrial applications The present invention is an electric heating board, a foot warmer, and an electric foot warmer.

This field relates to heating appliances such as electric floor heating, and in particular to the configuration and control of their heating elements.

BACKGROUND OF THE INVENTION A conventional heating element of this type of heating appliance has a structure as shown in FIG. 9, as shown in, for example, Japanese Utility Model Application Publication No. 57-200818.

That is, string-shaped metal heating wires 2 coated with vinyl chloride resin are uniformly wired in the heating surface component 1 of the heating device, and a heat insulating material 3.4 is provided below.

Note that 5 is a frame to which the heating surface component 1 and the heat insulating materials 3 and 4 are fixed. Here, 6 is a temperature control device such as a thermostat, which controls the temperature or prevents excessive temperature rise. In an electric heating board like the one shown in Figure 9, when the electricity is turned on, the surface temperature of the heating surface is 40 to 60°C.
The temperature was stable at an appropriate level, and the power consumption per unit area was about 200 to 400 W/n (approximately 200 to 400 W/n), providing comfortable heating as contact heating. Plastic materials such as vinyl chloride resin are used, but it is necessary to keep the temperature of the heating wire below the heat-resistant temperature of this material, and to keep the power per unit length below the 5 to 7 W/m level. This ensured heat resistance and safety as a heater.

Problems to be Solved by the Invention However, with the structure of such heating equipment, it takes about 3 minutes or more to feel a sense of warmth, and it is necessary to turn on the electricity at least 3 minutes before starting to use it. In particular, if you use it in front of the kitchen sink or washstand, you may not need to be there before it warms up after you turn on the power, so you may not need to stay there until it warms up after you turn on the power. It had the disadvantage that it would be of no use if it was not kept. In order to improve the heating speed of heating equipment, it can be assumed that the power consumption density will be increased.
Because heat dissipation conditions differ depending on things being placed on the heating surface, even if a temperature control device is installed appropriately, the power consumption per heating area of the heating equipment is approximately 400 W.
It was necessary to suppress it to below /nf.

In this way, when the power is turned on, these heating devices generate approximately 300
Although there was a strong demand for a rapid heating function that would provide a sense of warmth within seconds, simply increasing the power density until a satisfactory level of rapid heating could not be achieved when keeping local areas warm.
In the event of a failure of the temperature control device, there is a risk of abnormal overheating, smoke generation, or ignition. There was also a fear that the heat generated could damage the insulating exterior material and lead to electric shock.

On the other hand, as a means to improve rapid heating properties, for example,
A method has also been devised in which a positive resistance temperature coefficient heating element is constructed as shown in Japanese Patent No. 7-186997, and a large amount of electric power is utilized at the initial stage of energization of this heating element. In FIG. 10, a pair of band-shaped electrodes 8 are placed opposite each other on an insulating substrate 7.
, 9 are provided, and a positive resistance temperature coefficient resistor 10 is provided thereon.
is provided.

Due to this positive resistance temperature characteristic, this heating element component receives a large amount of power at the initial stage of energization, rapidly rises in temperature, and self-temperature-controls to an appropriate set temperature, which is one step ahead technologically. The goal was to create a heating device with improved comfort. However, although the heating speed is more than twice as fast as that using the above-mentioned metal heating wire, it takes more than a minute to feel the heat, and it seems that the electricity is turned on when it is used. As expected, it was not completed in time, and the performance was only middling.

Means for Solving the Problems In order to solve the above problems, the heating appliance of the present invention includes a heating element having a positive temperature coefficient of resistance, and a temperature at which the heating element has a temperature higher than the self-temperature control under this heat load condition. A heating appliance is applied that includes a control device that controls the heating element to a low temperature, and a heating element that has almost no positive temperature coefficient of resistance and is electrically connected in parallel to the heating element.

action The effect of this technical means is as follows.

In other words, in the initial stage of energization, at least by generating heat from a high-output positive resistance temperature coefficient heating element that stabilizes at a temperature higher than the appropriately set temperature of the heating element of this heating device, the heating surface can be rapidly heated with extremely high power density. This makes it possible to achieve rapid heating in seconds. In addition, after it has been sufficiently heated, the control device can stop the energization or control the energization at any time as necessary, while maintaining stable heat generation due to the heating element that has almost no positive resistance-temperature characteristics. We can provide comfortable heating equipment. In addition, although this positive resistance temperature coefficient heating element has a high output, it is stable at a certain temperature higher than the appropriate set temperature, so it is extremely safe with no risk of localized abnormal overheating, smoke, or ignition. .

Embodiments Hereinafter, embodiments of the present invention will be explained based on the accompanying drawings.
The heating device of this embodiment has a heating element configuration on the heating surface as shown in the perspective view of FIG. The stable temperature is 45°C at room temperature of 20°C.
is set to be. In Fig. 1, reference numeral 11 is a substrate/plate that is thermally coupled to the heating surface constituent material, and on this substrate there is a positive resistance temperature coefficient heating element 12, and a string having almost no positive resistance temperature characteristics. shaped metal resistance heating wire 1
3 is placed. Further, the metal resistance heating wire 13 is coated with vinyl chloride resin. Here, in order to set the temperature of the heating surface to the set temperature of 45°C, it is necessary to set the heating element temperature to 50°C in this example due to the thermal structure of the heating device. The temperature coefficient heating element 12 has the resistance-temperature characteristics shown in Fig. 2, and if there is no energization control, the self-controlled temperature will be about 90°C, higher than the set temperature of 50"C, when the energization is stable. It is a positive resistance temperature coefficient heating element. Also, as a device for controlling this positive resistance temperature coefficient heating element, a thermostat 14 is configured near the center of the heating surface. This is a circuit diagram, in which a positive resistance temperature coefficient heating element 12 and a metal resistance heating wire 13 are connected in parallel, and when the temperature rises, a thermostat 14 stops energizing the positive resistance temperature coefficient heating element 12. Note that 15 and 16 are overtemperature rise prevention devices to ensure safety in the event of an abnormality.

The positive resistance temperature coefficient heating element 12 has an ambient temperature of 20
℃, it is a positive resistance temperature coefficient heating element with a high output of 1F per heating element area; KW/rrf, and when electricity is applied, the temperature of this heating element rises rapidly, and the temperature of the heating surface rises extremely quickly. It becomes possible to achieve rapid heating. It is set so that when the temperature of the heating surface reaches the 45°C level, the contact of the thermostat I4 is opened and the 1ilft to the positive resistance temperature coefficient heating element 12 is stopped, and from this point on, the metal resistance heating wire 13 200-40 depending on
The power output is due to the power density of 0W/rrf level,
It provides stable and comfortable warmth. Furthermore, when it is cold and the warmth is insufficient, the contacts of the thermostat 14 are intermittently opened and closed to supply warmth, further improving comfort.

In addition, even in abnormal situations such as local heat retention at the initial stage of energization or failure of a temperature sensing element such as a thermostat, this positive resistance temperature coefficient heating element will self-temperature-controlled at 90°C, resulting in abnormal overheating, smoke generation, ignition, etc. It is very safe.

In fact, this electric heating board was energized in a room at a room temperature of 20°C to test its rapid heating properties. As a comparative example, a conventional electric heating board as shown in FIG. 9 was prepared in which the surface temperature of the heating surface was the same at 45° C. when the current was stable. Figure 4 shows the surface temperature characteristics of the heating surface at this time. As is clear from Fig. 4, when the electric heating board of this example is energized, about 370 W of power is input at the time of inrush, and about 10 seconds after energization, the temperature at the center of the heating surface reaches about 33°C, and the temperature rises in seconds. The speed was confusing the warmth. On the other hand, the conventional electric heating board has a constant power output of 50W from the beginning, and it does not reach the point where you can feel the warmth even after 4 minutes have passed.The heating device of the present invention has a dramatically faster heating speed. This type of rapid heating capability makes it possible to use heating equipment that only turns on electricity when it is desired to use it, and also has the advantage of leading to energy savings.

In FIG. 4, temperature characteristic A is a temperature characteristic diagram of another embodiment of the present invention, and the temperature characteristic A is the temperature characteristic diagram of another embodiment of the invention. This is a temperature characteristic of a heating device that is set so that, by adjusting the time, etc., the temperature of the heating surface is higher than the appropriately set temperature of the heating surface at a stable time, at least in the initial stage of energization. . When a user warms a cold body using contact heating, etc., it is very comfortable to warm the user's body at a temperature higher than the set temperature when the body is cold at the beginning of use. It is something that I have studied. Here, in cases where the number of users changes sequentially on a minute-by-minute basis, in order for not only the first user to enjoy this comfort, but also the next user to enjoy this comfort, it is necessary to It is desired that the temperature-sensing element is thermally coupled to the heating element, and that the positive resistance temperature coefficient heating element is on standby for the next use. By configuring the device to have relatively large heat dissipation, the usability can be greatly improved.

Next, FIG. 5 is a perspective view showing another embodiment of the present invention different from the above. Cane electrode 18.
19 is provided, and a positive resistance temperature coefficient resistor 20 is provided thereon.
is provided. Above this, a string-shaped metal resistance heating wire 21 having almost no positive resistance-temperature characteristics is arranged with an insulating film interposed therebetween. Further, 22 is a temperature sensing element that controls the energization of the positive resistance temperature coefficient heating element 20,
The electrical circuit is the same as the circuit diagram shown in FIG. 3 except for the overtemperature rise prevention device, and the same as in the above embodiment.
This allows heating equipment to achieve rapid heating in seconds.

By the way, a positive resistance temperature coefficient heating element always maintains a good temperature distribution in the direction between a pair of electrodes in order to make the temperature distribution of the heating element itself uniform, especially when large power density or high temperature is required. As a solution to this problem, as shown in Japanese Patent Publication No. 62-59515, a method has been adopted in which the distance between a pair of electrodes is made close to each other, and the distance between the electrodes is at least 3 mm or less, preferably less than 3 mm. is 1-
Below, it became possible to considerably increase the output of the positive resistance temperature coefficient heating element. Moreover, 1986-2840
As shown in Publication No. 82 and Figure 6, safety has been achieved through revolutionary improvements such as making the creepage distance along the outer surface of the positive resistance temperature coefficient resistor itself larger than the thickness of the resistor. It has also become possible to increase sexuality.

In Fig. 6, 23 is a thin positive resistance temperature coefficient resistor with a thickness of 0.4 mm made of conductive fine powder and a crystalline polymer, and is provided to apply a voltage in the direction of its thickness. A pair of electrodes 24 and 25 are configured.

26.27 is this resistor 23 and electrode 24.25
This is an exterior material that further exteriorizes the integrated body. With a positive resistance temperature coefficient heating element having such a configuration, it is possible to achieve a high output of IOW/cj or more at the initial stage of energization in an atmosphere of 20°C, and it is possible to further dramatically improve the heating speed of the heating device of the present invention. The positive resistance temperature coefficient heating element of the present invention may be made of an inorganic ceramic type in addition to the organic carbon black-resin type shown above, and has a positive resistance temperature coefficient of 0. Any heating element may be used as long as it has a heating element.

Next, FIG. 7.8 shows another embodiment of the electrical circuit diagram of the present invention. In FIG. 7, 28 is a positive resistance temperature coefficient heating element, 29.30 is a heating element having almost no positive resistance temperature characteristic, and 31 is a temperature sensing element. Also,
Figure 8 shows a new heating element 32 that has almost no positive resistance-temperature characteristics, 33 is a positive resistance temperature coefficient heating element, and 34.35 is a heating element that has almost no positive resistance-temperature characteristics. It is a heating element, and 36 is a temperature sensing element. In this way, a heating element having a positive temperature coefficient of resistance, a control device that controls the temperature of the heating element to be lower than the temperature at which the heating element is self-temperature controlled by this heat load condition, and a heating element that is electrically connected in parallel to the heating element. Any heating device may be used as long as it has a connected heating element with almost no positive resistance temperature coefficient, and the control of the positive resistance temperature coefficient heating element may be performed in addition to the temperature control described above. , even timer control by initial energization time, phase control.

ON-OFF control etc. may also be used.Also, the temperature sensing body is shown as a thermostat in the example diagram, but
The present invention is not limited to this, and electronic control using an NTCSPTC thermistor or the like may be used, and control suitable for the product use may be used. Also, the power supply is not limited to alternating current or direct current.

Effects of the Invention As described above, the heating appliance of the present invention includes a heating element having a positive temperature coefficient of resistance and a temperature lower than the temperature at which the heating element is self-temperature controlled under the heat load conditions. By providing a control device that controls a heating element and a heating element that has almost no positive temperature coefficient of resistance and is electrically connected in parallel to the heating element, it is possible to
By generating heat using a high-output positive resistance temperature coefficient heating element that stabilizes at a temperature higher than the appropriate set temperature of the heating element of this heating device, it is possible to rapidly heat the heating surface with extremely high power density. It has an extremely excellent effect of being able to achieve rapid heating in seconds.

In addition, although this positive resistance temperature coefficient heating element has a high output, it is stable at a certain temperature higher than the appropriate setting temperature, so
It is extremely safe as there is no risk of localized abnormal overheating, smoke, or fire. Furthermore, this rapid heating function makes it possible to use heating equipment that only turns on the electricity when you want to use it, which also has the advantage of leading to energy savings, creating a new concept different from that of conventional heating equipment. This is an extremely useful invention.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the heating element configuration of a heating appliance according to an embodiment of the present invention, Fig. 2 is a resistance temperature characteristic diagram of the positive resistance temperature coefficient heating element of the heating appliance, and Fig. 3 is an electric circuit of the heating appliance. 4 is a temperature characteristic diagram of the heating surface surface of a heating device according to an embodiment of the present invention at the initial stage of energization, FIG. 5 is a perspective view of the configuration of a heating element of a heating device according to another embodiment of the present invention, and FIG. The figure is a perspective view of a positive resistance temperature coefficient heating element of a heating device according to an embodiment of the present invention, FIG.
FIG. 8 is an electric circuit diagram of a heating device according to another embodiment of the present invention,
FIG. 9 is a sectional view of the configuration of a conventional warming device, and FIG. 10 is a perspective view of the configuration of a heating element of the conventional warming device. 11, 17...Substrate thermally coupled to the heating surface constituent material, 12, 28.33...Positive resistance temperature coefficient heating element, 13.21...Metal resistance Heat generating wire, 14.
...Thermostat, 15゜16 ... Temperature rise prevention device, 18.19.24.25 ...
Electrode, 20.23... Positive resistance temperature coefficient resistor,
22.3136... Temperature sensing body, 26.27.
...Exterior material, 29.3032+ 34.35...
...Heating element with almost no positive resistance-temperature characteristics.

Claims (8)

[Claims] (1) A heating element having a positive temperature coefficient of resistance, a control device that controls the heating element to a temperature lower than the temperature at which the heating element is self-temperature controlled according to the heat load condition, and an electrical connection to the heating element. and a heating element having almost no positive temperature coefficient of resistance connected in parallel to the heating element. (2) The heating device according to claim (1), wherein the control device includes a temperature sensor that controls energization of the positive resistance temperature coefficient heating element by detecting temperature. (3) Claim (2) wherein the temperature sensing element is a thermostat and is electrically connected in series with the positive resistance temperature coefficient heating element.
) mentioned heating equipment. (4) The heating device according to claim (3), wherein the temperature sensor is thermally coupled to the heating element and configured to have relatively large heat radiation. (5) The heating device according to claim 1, wherein the control device is based on timer control that controls the energization of the positive resistance temperature coefficient heating element by detecting the energization time of the heating element. (6) The positive resistance temperature coefficient heating element consists of a thin positive resistance temperature coefficient resistor made of conductive fine powder and a crystalline polymer, and a pair of electrode bodies provided to apply a voltage in the thickness direction. Claim (1), (2) or (5), which is a heating element comprising:
The heating equipment listed. (7) The heating device according to claim (6), wherein the positive resistance temperature coefficient resistor has a thickness of 1 mm or less. (8) The heating surface according to claim (1), (2), (5) or (6), wherein at least in the initial stage of energization, the heating surface has a portion whose temperature is higher than the appropriately set temperature of the heating surface in a stable state. Heating equipment.