JPS59229132A - Foot-warmer with frame and legs - Google Patents

Abstract

PURPOSE:To contrive to shorten the required time for the sensing of warm feeling, also to obtain the uniform and gentle warm feeling by a method wherein a low power density high emissivity heat generating body and a high power density high emissivity heat generating body are provided on the inner ceiling surface of the titled foot-warmer, while, the former covers nearly all part thereof and the latter covers small part of the ceiling surface. CONSTITUTION:The titled foot-warmer 4 is composed of a low power density high emissivity heat generating body 5 and a high power density high emissivity heat generating body 6, the former having large surface area is arranged on the inner ceiling surface of the foot-warmer frame 4, covers nearly all part of the inner ceiling surface of the foot-warmer, while the latter having small surface area is also arranged on the inner ceiling surface. The heat generating body 5 has the characteristics such as a slow temperature starting and a uniform radiation heat due to the long wavelength, consequently, the uniform and gentle warm feeling can be sensed. The heat generating body 6 is heated by the radiation heat just after the energizing with a rapid temperature starting, accordingly, the speedy warm feeling can be sensed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a tower kotatsu placed on the floor and used for heating.

Conventional structure and its problems Yagura kotatsu is one of the excellent heating systems with high energy utilization efficiency as a local heating device. The required performance is to be able to feel a warm sensation as soon as the power is turned on, and to be able to get a uniform and soft feeling of warmth. Most conventional Yagura Kotatsu have focused on the former performance, and as shown in Figure 1, many have used high-power-density metal heating wires that heat quickly as the heat source. In Figure 1, 1 is a tube heating element with a built-in metal heating wire, 2 is a card,
3 is the leg and 4 is the tower. In order to improve the heating rate, it is advantageous to increase the wire temperature, and until now efforts have been made in this direction. However, when the linear temperature is increased, the wavelength of the radiated infrared rays changes to the shorter wavelength side, which not only stimulates the painful point, but also causes the radiant energy distribution to become non-uniform as the size and shape of the heat source become smaller. It was a far cry from the soft, warm feeling. On the other hand, attempts have been made to use a planar heating element as a heat source to provide a uniform and soft feeling of warmth, but in this case, the time from turning on the power until a feeling of warmth is felt tends to be longer. Ta.

Purpose of the Invention In view of the above-mentioned points, the present invention simultaneously satisfies the contradictory demands of shortening the time from when the power is turned on until the sensation of warmth is obtained, and at the same time providing a uniform and soft sensation of warmth. The purpose is to realize Yagura Kotatsu.

Structure of the Invention The structure consists of a tower, a high emissivity heating element with a large area and low power density, which is provided on the inner face of the tower and occupies a majority of the inner face, and a high emissivity heating element with a small area and high power density. The basic structure consists of a radiant heating element.

DESCRIPTION OF EMBODIMENTS Below, explanations will be added based on embodiments. FIG. 2 is a diagram showing an embodiment based on the present invention, and 5 indicates a stable temperature of 90°C.
, power density 50W/rr? , area 0.4ze, power 2oo
W sheet heating element, 6 has stable temperature 300℃, power density 5
000W/rr? + Area 0. o4 go, power 200
It is a planar heating element of W, and 7 is its guard. A high emissivity surface material is provided on the surface of each heating element.
Heat can be radiated efficiently. Although the temperature rises slowly from the 60 large-area heating element, it radiates uniform radiant heat with long wavelengths, so you can get a uniform and soft feeling of warmth.
The small-area heating element No. 6 quickly rises in temperature after the start of energization and radiates heat, so you can immediately feel a sense of warmth. As shown in Figure 3, it is difficult to start up a heating element with low power density and a large area for a short time with limited power. Since it is also affected by the rise in ambient temperature, only a slow start-up as shown in curve 8 can be obtained. On the other hand, as the temperature of a high-power-density heating element increases, the heat dissipated by radiation increases rapidly, and the temperature does not immediately reach a saturated state. Also, the degree of influence of the atmosphere is /J\, so the curve 9 A fast start-up as shown is obtained. This tendency becomes stronger as the power density increases. To improve the rise of low power density heating elements,
If a resistor with the resistance-temperature characteristics shown in Figure 4 is used, several times as much power as in the stable state is applied during startup, and the resistance value increases rapidly in a predetermined temperature range. A fast rise like the curve of is possible. Naturally, this characteristic significantly shortens the time it takes to feel a warm sensation. Furthermore, another important feature of the positive resistance temperature characteristic heating element is that even with such a large area heating element, local heat dissipation conditions such as washing, washing, etc. Even if there is an abnormality, the resistors in each part limit the power in a direction that equalizes the temperature, which is extremely superior in terms of temperature distribution and safety.

Next, explanations will be added based on other embodiments. FIG. 6 is a diagram showing the electrical connection state between a large-area heating element 6 with a stable and extremely low power density and a positive resistance temperature characteristic, and a heating element 6' with a small area and high power density, both of which are connected in series. It is connected. As an example of this effect is shown in Fig. 6, the resistance at room temperature is 1o
Q, heating element 6' for heating element 5 with inrush power of 1000W
It varies somewhat depending on the size of the resistance value. In FIG. 6, curves 11 and 11' correspond to the case where the heating element 6' is short-circuited, and as the temperature of the heating element 5 increases rapidly after the start of energization, the electric power also decreases rapidly. Curves 12 and 12' are 5Q
When heating elements 6' are connected in series, the inrush power is 66
The inrush power distributed to the heating element 5 is reduced to 444 W, which is less than half of that when the heating element 6' is short-circuited. Therefore, the rate of temperature rise of the heating element 5 is significantly reduced, and the time required for the resistance value to increase becomes considerably longer. Eventually, as time passes, the resistance value of the heating element 6 starts to increase due to the increase in the temperature of the atmosphere due to the 222 W generated from the heating element 6', and the resistance value of 60 of the heating element 6' becomes smaller than that of the heating element 5. Approximately 1
/1o. In this state, curves 11 and 12 naturally almost match.

However, the integrated power input is larger for song a12,
Moreover, since a part of the heat is supplied to the heating element 6' which has a quick rise time, a feeling of warmth can be obtained in a much shorter time. This can be measured as a difference in floor surface temperature. Curves 13 and 13
In this case, the above-mentioned tendency is even more pronounced in the case where 10 Q heating elements 6' are connected in series. If the resistance value of the generator 6/ is further increased, not only will the absolute amount of power required for startup decrease, but the heating element 6 will only effectively generate heat under certain conditions, and its effectiveness will be almost completely lost. I end up. As is clear from this, the heating element 5 must be in a state where it has the function of detecting the temperature inside the Yagura Kotatsu, reflecting it in the resistance value, and switching between the rising state and the stable state. It is also necessary to avoid an increase in the resistance value immediately after starting energization due to its own heat generation, and most importantly, it is necessary to have a heating ability that provides a uniform and soft feeling of warmth. Therefore, the heating element 5 needs to occupy the majority of the area of the inner top surface of the tower in order to have heat dissipation ability, atmosphere detection ability, and uniform heating ability.
In order to reflect the ambient temperature in the resistance value, a characteristic is required in which the resistance value increases significantly when the ambient temperature is around 80° C. or lower, which is the normal upper limit value. Note that the heating elements 6 and 6
By making the resistance value of ' variable, it is possible to construct a circuit that can easily adjust not only the strength scale but also the start-up speed and the mode of warmth sensation. In addition, if a changeover switch 7 is provided that allows selection of connection combinations of individual connection, series connection, or parallel connection of the heating elements 5 and 6', for example, four types of start-up as shown in FIG. Characteristics and power can be adjusted. By incorporating an appropriate temperature control circuit into this, it is possible to create a Yagura Kotatsu that can be used in any region and for any purpose. In FIG. 7, curve 14 represents the case where a positive resistance temperature characteristic heating element with a room temperature resistance of 10Q is used alone.
Curve 16 is when a 20Q high power density heating element is used alone.
Curve 16 shows the case where both are connected in series, and curve 17 shows the case where they are connected in parallel.

The placement of the heating element is arbitrary, but in order to effectively use the narrow space of the Yagura Kotatsu, to sufficiently heat the surrounding area, and to evenly distribute the warm sensation when the kotatsu rises, it is necessary to
As shown in Figure 8, a low power density heating element 18 is placed around the inner top surface of the tower kotatsu, and a high power density heating element 1 is placed in the center.
9 is the most desirable method. It is necessary to place a guard 19 on the high power density heating element 19 to prevent burns, but for the low power density heating element 18,
To prevent instant burns, it may be sufficient to provide a thermal buffer film with low thermal conductivity on the surface or a thin net thermal buffer structure, especially when using a heating element with positive resistance temperature characteristics. If the heating element has a high power density, it will not cause abnormal local heating even if it is covered with cloth, etc., so there is no problem in terms of safety. However, it goes without saying that it is more effective to use a heating element that emits warm visual light in addition to infrared radiation in order to visually appeal to the sense of warmth when the temperature rises. .

Effects of the Invention As stated above, the present invention represents a very effective and effective means for increasing the comfort while maintaining the quick heating performance of the Yagura Kotatsu. It brings out the maximum of

[Brief explanation of the drawing]

Figure 1 is a side view of a conventional Yagura Kotatsu, Figure 2 is a side view of a Yagura Kotatsu according to an embodiment of the present invention, Figure 3 is a temperature rise characteristic diagram of the heating element, and Figure 4 is the same. Figure 5 is a circuit diagram showing the electrical connection state of the heating element, Figure 6 is a diagram showing the temperature and power start-up characteristics of the same Yagura Kotatsu, and Figure 7 is a diagram showing the temperature and power characteristics of the heating element. FIG. 8 is a front view of the tower kotatsu, which is a diagram showing the power start-up characteristics of the tower kotatsu. 3...Legs, 4...Yagura, 5...
...Low power density heating element, 6...High power density heating element. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (7)

[Claims] (1) A tower, a large area, low power density, high emissivity heating element installed on the white side of the tower and occupying a majority of the inner surface, and a small area, high power density, high emissivity heating element. Yagura kotatsu consisting of. (2) The tower kotatsu according to claim 1, wherein the large area, low power density, high emissivity generating body is a positive resistance temperature coefficient heating element. (3) Claims 1 or 2 comprising a large-area, low-power-density high-emissivity heating element and a small-area, high-power-density, high-emissivity heating element electrically connected in series. The Yagura Kotatsu mentioned above. (4) Connect a large-area, low-power-density, high-emissivity heating element and a small-area, high-power-density, high-emissivity heating element using a changeover switch that can be electrically switched independently or in series or parallel. A tower kotatsu according to claim 1 or 2. (5) A patent claim in which a large-area, low-power-density, high-emissivity heating element is arranged at the periphery of the inner face of the tower, and a small-area, high-power-density, high-emissivity heating element is arranged in the center. Yagura kotatsu as described in item 1 or 2 of the range. (6) Provide a thin thermal buffer or thermal buffer structure material on the surface of a large-area, low-power-density, high-emissivity heating element, and provide a protective guard around the small-area, high-power-density, high-emissivity heating element. A tower kotatsu according to claim 1 or 2, comprising: (7) A tower kotatsu according to claim 1 or 2, which has a structure in which a small area, high power density, high radiation heating element generates warm visible light as well as infrared rays.