JPS5842193A - Heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure, and more particularly, to a heater that has a self-temperature control function and is suitable for defrosting heaters used in refrigerators, etc. .

In general, refrigerator coolers or air conditioner coolers are designed to protect against water vapor generated from items stored in the refrigerator, trapped air that enters the refrigerator when the door is opened/closed, or outside air. Frost formation occurs due to the temperature difference with the indoor air. When frost adheres to the cooler, the heat exchange efficiency of the cooler decreases and the cooling capacity decreases. Therefore, in the refrigerator,
Conventionally, a vibration damper is installed on the heat exchange fins attached to the refrigerant pipes of the cooler, and each time the refrigerator has been operating for a certain period of time, the operation of the refrigerator's cooling system is stopped and electricity is turned on to the defrosting heater. Then, the defrosting heater is heated to remove the moisture, thereby preventing the cooling capacity from decreasing. In addition, in the case of air conditioning equipment, when frost occurs, the operation of the air conditioning equipment is stopped for a certain period of time, and
The frost is removed by the heat of the outside air, and the defrosting process takes place at 2'-C.

Conventionally, as a defrosting heater for a refrigerator, a metal heater wire such as a nichrome wire, a nickel wire, or a copper wire is housed in a protective tube such as an aluminum pipe, and a portion thereof is used.

Some of these conventional defrosting heaters do not have a self-temperature control function, but because they have the characteristic of maintaining a constant amount of heat regardless of the amount of frost attached to the cooler and the frost distribution, The time when defrosting is completed differs for each part. In other words, defrosting is delayed in areas where frost is heavily deposited. Conventionally, in order to detect when defrosting is complete, a circstar-type temperature sensing device is installed in the part of the cooler where defrosting is completed the latest, and the temperature is detected while defrosting. It is assumed that defrosting is completed when a certain temperature is reached, which is 7t4. t
Furthermore, in consideration of the possibility that the amount of frost may increase due to seasonal changes, or the distribution of frost may change due to differences in the arrangement of stored items, sufficient measures should be taken in both cases. Next, it is necessary to set defrosting conditions such as temperature and time so that defrosting occurs. For this reason, the amount of frost on the cooler is small,
The temperature of the portion where defrosting is completed early becomes unnecessarily high as the electricity supply time increases. i*, energize the heater #! There is a large temperature difference between the temperatures of each part of the cooler at the time of completion. If the temperature of the cooler becomes unnecessarily high, it will take a long time to lower the temperature of the cooler when the cooling operation resumes after the vibration isolation is completed, and the power consumption will increase. ing.

t*.Furthermore, there is a drawback that the electric power required to heat the defrosting heater is unnecessarily large. However, there is a drawback that the temperature of foods stored in the refrigerator tends to rise.

On the other hand, some organic materials are known as heaters that have a self-temperature control function. The structure of this heater is shown in Figure 1.
, Ch”) and shown in FIG.

In Fig. 1 (a) # (h) and Fig. 2, 1 and 1 # are electrical conductors for daughter-in-law feeding, which are made of tinned copper wire, for example, and 2 is a mixed conductor of high-density polyethylene thick organic material and carbon. 3 is an insulating material part such as urethane rubber, and 4 is a heat generating part having a self-temperature control function.
is a purulent covering material portion made of, for example, polyethylene or the like. Although the cross-sectional shapes of the two shown in Figure 1 (I(b)K and ℃2 shown in Figure 2 are different in terms of their configurations), there is no essential difference in their configurations. When used as a heater, the heater is installed in the opening of the heat exchange fins (not shown) of the cooler (not shown) as shown in FIG. 1 (cL) #Cb). It is necessary to use the heater by storing it in a pipe with good thermal conductivity, such as aluminum. Although this heater operates as a defrosting device with very good defrosting performance, it is not always sufficient in terms of heat transfer and assembly man-hours.
In other words, when using a heater with the structure shown in Fig. 1 (@), (b) or Fig. 2, an air layer is inevitably created between it and the storage pipe. Poor communication,
It cannot be said to be optimal in terms of heat transfer. If it contains a self-temperature control function, it will require a process of inserting a part into the storage pipe, which requires a lot of time.To reduce the labor of the insertion process, The inner diameter must be increased, which further deteriorates heat transfer.

In addition, positive temperature characteristics with self-temperature control effect→4
Organic semiconductor heaters suffer from the pinch effect, as the distance between the feeding electrical conductors increases.

That is, the electric field concentration phenomenon is likely to occur, and as a result, only a portion of the heating element material between the power supply electrodes is at a high temperature, and the entire multi-heating element material section does not operate effectively.

That is, as shown in FIG. 5, between the power supply electrodes.

A m degree distribution occurs in the temperature in the region 6 connecting the bodies 1 and 1-, and the force where only the temperature in the central part 2 between the power supply electric conductors of the heating element part 2 is high is effective for the other heating element parts 2. However, there is a drawback that the heat generation operation is stopped and the heat output decreases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a defrosting heater that eliminates the drawbacks of the above-mentioned techniques, has excellent heat transfer characteristics, and is easy to assemble.

In order to achieve the above object, in the present invention, two or more pairs of power supplying electric conductor tubes are arranged in a heating element part having a self-temperature control function, which is composed of a conductive material and an organic material, and adjacent power supplying The distances between the conductors are arranged in substantially concentric positions.

Then, a protective coating made of a good thermal conductor is formed on the outside of the electrically insulating material in close contact with the electrically insulating material.

As described above, the necessary conditions for heat transfer that the heater should have are: 1) good thermal contact between the object to be heated and the heater; 2) Thermal J1 between the heat generating part of the heater and the outermost heat radiation surface of the heater is small.

Itoto. 5) Particularly in a heater having a self-temperature control function, the entire group of heat-generating materials operates effectively.

In the present invention, by structuring the heater as described above, it is difficult to generate a heat-generating concentrated area due to the pinch effect, the entire heat-generating material group operates effectively, and it forms a protective coating by closely contacting the TFT electrical insulating material part, thereby generating heat. To form an excellent heater with little thermal loss between a body part and an outermost protective covering part.

However, in the present invention, a cavity is formed in the heating element, and this cavity relieves the internal stress that occurs when the heating element generates heat and expands. prevent physical properties from changing due to internal stress. That is,
The coefficient of thermal expansion of the protective coating and the heating element are different; the coefficient of thermal expansion of the heating element is greater than the coefficient of thermal expansion of the protective coating, and even when the heating element generates heat and expands, the characteristics of the heating element change. prevent

The structure of the defrosting heater according to the present invention is shown in FIGS.
). Figure 4, (S, (b), 7.7.8
．． 8 is an electrical conductor for power supply, which is made of, for example, a tin-plated copper wire, and 9 is a mixed conductor made of an organic material such as high-density polyethylene and a conductive material such as graphite or carbon. The heating element 10 having a self-temperature control function is made of urethane rubber,
Electrical insulating material part made of polyvinyl fluoride, -IJden, etc.
Reference numeral 11 denotes a protective cover made of a material with good thermal conductivity, and is made of, for example, steel or aluminum. 12
is a cavity or a filling portion filled with a heat-resistant elastic material such as glass wool.

Next, the operation of the heater according to the present invention will be explained.

By applying the rated voltage between the power supply electric conductors 7, 7I and 8, 81], the heating element portion 9, that is, the power supply electric conductors 7, 8, 8 and 7', 7' and 8', A current flows between 8# and 7, and the heating element part 9 generates heat due to the heat generated by the metal. Then, due to the temperature rise due to heat generation, the organic material constituting the multiple heating element section 9t expands, and the internal resistance of the heating element section 9 increases.
As a result, the current flowing through the heating element portion 9 decreases. When the current decreases, the temperature of the heating element 9 rises to a certain temperature determined by the characteristics of the organic material, that is, the heating element 9, and then the temperature is maintained at the rated temperature. In the case of heaters with the same heat dissipation area, as shown in Figure 4 (A), the current per power supply conductor is reduced by using t-4 or more power supply conductors and arranging them concentrically. However, since the cross-sectional area of the power supply conductor can be made small, the distance from the effective heating operation part of the heating element section 9 to the outermost heat radiation w of the heater can be made small, and the heat loss due to the heat transfer path can be made small. , a companion that can reduce the spacing between electrical conductors for power supply,
It can be a pinch effect. Further, the protective covering part 11 made of a material with good thermal conductivity and provided at the outermost part of the dividing heater shown in FIGS. 4(g) and (A) is similar to the electrically insulating material part 10.
In the heater manufacturing process, the heating element part 9 and the electrical insulating material part 1 are
0. Good adhesion between the protective coating parts 11 makes it possible to minimize thermal loss.

tyc, the conventional process of inserting a heating wire into a pipe made of aluminum or the like is completely unnecessary.

In addition, as described above, in the case where the heat generating body part 11't-fc is integrated, the heat generating body part 11' has good thermal conductivity and has a coefficient of thermal expansion different from that of the heat generating body part 9 and the electrical material insulating part 10. 9 thermally expands or contracts, and one of the characteristics of the heating element 9 changes. Swelling: The stress generated by stroking is relieved by the cavity 12! No problems occur.The cavity 12 provided at the center of the heater has the following properties: It may be filled with a material that is heat resistant and has an elasticity of 1.

Although the above-described embodiment shows the case where there are four power supply conductors, the same effect can be obtained even if six or more power supply conductors are used, for example. This heater has a heat generating part 9, a power supply electric conductor 77', 8.8',
Electrical conductors 7, 7#, 8, 8# for power supply and insulating material part 10
．． Since the insulating material portion 10 and the protective portion 11 are in close contact with each other, the heat generated in the heat generating portion 9 is efficiently transferred to the protective portion 111, and therefore the heat transfer characteristics are improved.

The above-mentioned hole heater was attached to the fin section (not shown) of a refrigerator cooler using the hook-in method, similar to a conventional heater, and combined with a defrosting control circuit, and a defrosting experiment was conducted. Since the heat transfer characteristics from the heating element of the heater to the cooler fins were improved, the time required for defrosting could be shortened. tm heat transfer characteristics are improved and the area of the effective heat generating part is increased, so even if a heater with a low rated temperature is used as a heater with a self-temperature control function, it can be put to practical use. The power consumption required for this has been reduced by 15 to 25 seats compared to conventional models.

As explained above, according to the misfire, at least four, that is, two pairs of power supply gas conductors are arranged on the heating element part, approximately spaced apart from each other, and a protective coating with good heat conduction is attached to the heating element. Because it is attached to the electrically insulating material part placed on the outside, heat is generated almost uniformly throughout the heating element part.
In addition, the heat generated in the heating element is well transmitted to the protective coating, and a portion of the heat loss inside the heater can be reduced.

[Brief explanation of the drawing]

Figures 1 (#) and 2 are diagrams showing the structure of a conventional heater with a self-temperature control function. Figure 1 (-) is an enlarged view, Figure 1 (b) is Figure 2 is a cross-sectional view, Figure 3 is a characteristic diagram showing the temperature gradient in a conventional heater, and Figure 4 (g
), '(ri is a diagram showing a heater according to the present invention, and FIG.
11) is a front view, and FIG. 4 is a sectional view.

Claims (1)

[Claims] t. A heating element made of a conductive material and an organic material, a power supply electric conductor disposed inside the heating element, and an insulating material disposed outside the heating element. In the equipped heater, at least two pairs of electric conductors for power supply are disposed within the heating element part, and are arranged on the outside of the insulating material part in close contact with the insulating material part.
It is said that it is characterized by a protective coating made of a material that is a good thermal conductor. 2. A heater comprising a heating element made of a conductive material and an organic material, a power supply electric conductor disposed inside the heating element, and an insulating material disposed outside the heating element, at least Two pairs of electric conductors for power supply are arranged inside the heating element part, and on the outside of the insulating material part, in close contact with the insulating material part,
A protective covering made of a material that is a good thermal conductor is formed, and
A heater in which a cavity is formed in the center of the heating element, and the heating element is formed in a ring shape.