JPH0955285A - Sheet heating element and heater for generating hot air - Google Patents

Abstract

(57) Abstract: To provide a planar heating element capable of quickly soaking even if only a part of the heating element changes in temperature. SOLUTION: A pair of electrodes 4 are formed on a heat-resistant insulating substrate 2, and a plurality of film-shaped resistance heating elements 3 which electrically connect the electrode pairs in parallel are formed. The film-like resistance heating element 3 has a positive electric resistance that changes its resistance value in the same direction as the temperature change.
-Has temperature characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet heating element and a heater for generating warm air. For more details,
The present invention relates to a sheet heating element used as a heating heater in a domestic cooker, a heater, etc., and a warm air generating heater used in a warm air heater, etc.

[0002]

2. Description of the Related Art Conventionally, household cookers, heaters, etc.
Nichrome wire heaters and sheathed heaters are mainly used as heating heaters. When these heating heaters are used for cooking hot plates or heating panel heaters, for example, it is necessary to uniformly heat a relatively large area. Therefore, in addition to the above heater, a soaking plate such as an aluminum plate having good thermal conductivity is also used. Although the heating area can be expanded by the soaking plate, the method using the soaking plate has drawbacks such as low energy efficiency, slow rising temperature of rising temperature, and poor soaking. In order to solve these problems, JP-A-57-10
No. 7583, Japanese Patent Laid-Open No. 3-108294 and the like propose a planar heating element in which a resistance heating element is integrally formed on an insulating substrate by printing or the like.

The nichrome wire heater is sometimes used as a heater for generating hot air, but since it is used with a high electric power for heating, there is a risk that the nichrome wire heater itself becomes red. For this reason, PTC (Positive Temperatur
A corrugated aluminum radiator is attached to a ceramic heater plate having an e-coefficient characteristic (that is, a positive electric resistance-temperature characteristic) to suppress the temperature of the heater itself to a low temperature.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The sheet heating element proposed in Japanese Patent No. 7583, Japanese Unexamined Patent Publication No. 3-108294, etc. is effective for achieving an initial soaking and avoiding a functional stop due to a partial loss of the resistance heating element. However, when part of the resistance heating element that is generating heat is cooled (for example, when food such as cooked food is placed on the hot plate for cooking), the temperature of only the part where the temperature drops is quickly raised. Then, there is a problem that the temperature cannot be soaked. Similarly, when the heat radiation of a part of the resistance heating element is blocked (for example, when an object is placed in the heat radiation part of a radiant heater or a natural convection heating machine), abnormal heating occurs in a part of the resistance heating element. There are problems such as occurrence.

On the other hand, the above-mentioned heater for generating warm air has a problem that it is difficult for a simple propeller fan to blow air with an appropriate amount of air because the pressure loss during blowing air by the aluminum radiator is large. In addition, if the positional / temporal air volume balance during air blowing is disrupted, the air blowing temperature will change and hot air of an appropriate temperature cannot be obtained.

The present invention has been made in view of these points, and an object of the invention is to provide a planar heating element capable of achieving uniform heating quickly even if only a part of the heating element changes in temperature. And Moreover, it aims at providing the heater for warm air generation which can obtain the warm air of suitable air volume and temperature easily.

[0007]

In order to achieve the above object, the sheet heating element of the first invention comprises an electrode pair on a heat-resistant insulating substrate and a plurality of film-like elements electrically connecting the electrode pair in parallel. A planar heating element formed by forming a resistance heating element, wherein the film-shaped resistance heating element has a positive electric resistance-temperature characteristic that changes its resistance value in the same direction as a change in temperature. To do.

According to the structure of the first invention, even if the temperature of a part of the sheet heating element changes, the self-temperature control is performed by the action of each film-like resistance heating element as described below. For example, when voltage is applied to the electrode pair and the film resistance heating element or the heat-resistant insulating substrate heats up, if the temperature of that part of the heat-resistant insulating substrate is lowered by cooling, the heat-resistant insulation The temperature of the film-like resistance heating element formed in the portion where the temperature of the flexible substrate is lowered also drops.
An example of such a case where the temperature of a part of the film-shaped resistance heating element is lowered is the case where food is placed on a hot plate for cooking.

Since the film-like resistance heating element has a positive electric resistance-temperature characteristic that changes its resistance value in the same direction as the temperature change, the resistance value of the film-like resistance heating element in the portion where the temperature is lowered also decreases. To do. As a result, among the plurality of film-shaped resistance heating elements, a larger amount of current flows through the film-shaped resistance heating element whose temperature has decreased than that of the other film-shaped resistance heating elements. Therefore, the electric power (that is, the calorific value) is selectively concentrated on the part where a large amount of heat is required due to the cooling, and as a result, the calorific value is quickly replenished to that part and the temperature rises. It will be accelerated.

On the contrary, when the temperature of only a part of the heat-resistant insulating substrate rises, the film-like resistance heating element acts in the opposite manner. This will be described in more detail. For example, when voltage is applied to the electrode pair and the film-like resistance heating element or the heat-resistant insulating substrate is heated, if the temperature of the heat-resistant insulating substrate rises due to excessive heat generation, the heat The temperature of the film-like resistance heating element formed in the portion where the temperature of the insulating substrate rises also rises. An example of such a case where the temperature of a part of the film-shaped resistance heating element rises is a case where a part of the heating panel heater blocks heat radiation by an object such as a towel.

Since the film-like resistance heating element has a positive electric resistance-temperature characteristic that changes its resistance value in the same direction as the change in temperature, the resistance value of the film-like resistance heating element in the portion where the temperature rises also increases. . As a result, among the plurality of film-shaped resistance heating elements, a smaller amount of current flows through the film-shaped resistance heating element whose temperature has risen than in other film-shaped resistance heating elements.
Therefore, the electric power of the portion where it is necessary to suppress excessive heat generation is selectively suppressed, and as a result, it becomes difficult to supplement the heat generation amount to that portion, and partial abnormal heating is suppressed.

In the sheet heating element of the second invention, in the constitution of the first invention, the plurality of heating element groups each including the electrode pair and the film-like resistance heating element are electrically arranged in parallel. It is characterized in that it is formed on a heat-resistant insulating substrate.

According to the configuration of the second invention, the film-like resistance heating element is subdivided into a plurality of heating element groups, and the heating element groups are electrically arranged in parallel. Even if is formed into a shape close to a square, the distance between the electrodes can be made as short as possible, and the accuracy of selectively concentrating the amount of heat is improved.

In the sheet heating element of the third aspect of the invention, in the structure of the first and second aspects of the invention, a substrate having infrared transparency is used as the heat resistant insulating substrate, and the electrode is provided on one surface of the substrate. A pair and a film-like resistance heating element are formed, and a fluororesin film is formed on the other surface.

The heat from the film-like resistance heating element is transferred to the side surface of the fluororesin film of the heat-resistant insulating substrate by heat conduction, and at the same time, transferred to the side surface of the fluororesin film of the heat-resistant insulating substrate as infrared rays (that is, heat rays). Since the heat-resistant insulating substrate has infrared transparency as described above, infrared rays radiated from the film resistance heating element easily reach the surface of the heat-resistant insulating substrate on the fluororesin film side. Infrared rays that have passed through the heat-resistant insulating substrate with high efficiency enter the fluororesin film, so that the fluororesin film efficiently absorbs the infrared rays. Further, when the sheet heating element is used for a cooking plate or the like, the fluororesin film improves the releasability of the food material.

In the warm air generating heater of the fourth invention, a plurality of sheet heating elements according to the first and second inventions are used, arranged in a louver shape, and electrically connected in parallel. Characterize.

According to the structure of the fourth aspect of the invention, since the sheet heating elements are arranged in a louver shape, the pressure loss at the time of blowing air is small, and therefore the air flow is not significantly reduced by the pressure loss. In addition, since it is a simple configuration that only arranges the sheet heating elements in a louver shape,
By changing the shape, the number of sheets, the interval, etc. of the sheet heating element, it is possible to easily match the required electric power, heat quantity, air volume, warm air temperature, blower fan characteristics, etc. at low cost.

Furthermore, since the sheet heating elements provided with the film-like resistance heating elements are electrically connected in parallel, even if the positional or temporal air flow balance is disrupted during air blowing, each sheet heating element is destroyed. As a result of the heating balance, the blast temperature self-recovers, and as a result, temperature changes are suppressed. In other words, when the temperature of each film-like resistance heating element drops due to some cause, the resistance value decreases and a large amount of current flows, resulting in an increase in power consumption and suppression of temperature drop. When the temperature rises, the resistance value rises and it becomes difficult for current to flow. As a result, the power consumption decreases and the temperature rise is suppressed.

In the heater for generating hot air of the fifth invention, in the structure of the fourth invention, an adsorbent and an oxidation catalyst are coated with an inorganic binder on the outermost surface of the planar heating elements arranged in the louver shape. It is characterized by having a deodorizing function by being formed. According to the configuration of the present invention, the adsorbent exerts a deodorizing effect by adsorbing the odorous component at room temperature, the oxidation catalyst exerts a deodorizing effect by oxidatively decomposing the odorous component when heated, and the oxidation catalyst is the adsorbent. It also oxidizes and decomposes the odorous components adsorbed by.

In the heater for generating warm air of the sixth invention, in the constitutions of the fourth and fifth inventions, the planar heating elements arranged in the louver shape are movably provided to have a rectifying function. It is characterized by According to the configuration of the present invention, since the sheet heating element is movable, by moving the sheet heating element, the flow of warm air can be changed according to the moved state.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A planar heating element and a heater for generating hot air embodying the present invention will be described below with reference to the drawings. In addition, the same reference numerals are given to the same portions or corresponding portions in the embodiments, and the duplicate description will be omitted.

<< Flat heating element 1 for heater (FIGS. 1 to 3) >>
1 to 3 are plan views of a planar heating element 1 for a heating machine in which the present invention is implemented. The heat-resistant insulating substrate 2 is made of lithia-based crystallized glass ceramics, and on the heat-resistant insulating substrate 2, a pair of silver (Ag) -based electrodes 4 facing each other.
And a plurality of film-like resistance heating elements 3 are all formed into a film by printing or the like. The film-like resistance heating element 3 has a structure in which a pair of electrodes 4 are electrically connected in parallel. In this structure, the electrode 4 is provided on the end of the film-like resistance heating element 3.
It is obtained by partially overlapping. The film-like resistance heating element 3 has a positive electric resistance-temperature characteristic that changes its resistance value in the same direction as the temperature change.
(Positive Electrical Resistance-Temperature Coefficient) TCR.

Regarding the printing pattern of the film-like resistance heating element 3, the one shown in FIGS. 1 to 3 is only one example. Therefore, the shape is not limited to the linear shape parallel to each other as shown in FIG. 1 and the zigzag shape as shown in FIGS. 2 and 3, and other types depending on the performance of the planar heating element 1 used. You may use the kind. Further, the width, thickness and length of one film-shaped resistance heating element 3 are determined according to the surface resistance according to the type of the sheet heating element 1 to be used.

<Manufacturing Method of Sheet Heater 1> First, a conductive material (for example, a particulate conductive material) such as nickel, silver or tin oxide,
A glass frit such as borosilicate glass frit is mixed with a cellulose resin, an acrylic resin, terpineol or the like to form a paste. Then, the obtained conductive material paste is screen-printed on the surface of the heat-resistant insulating substrate 2. After being dried at 100 ° C. for about 30 minutes and baked at 900 ° C. for 10 minutes, the sheet heating element 1 is obtained. In addition,
When a material that is difficult to oxidize at high temperature, such as silver or tin oxide, is used as the conductive material, firing may be performed in the air, but when a conductive material that is easily oxidizable at high temperature, such as nickel, is used, it may be baked in a nitrogen atmosphere. It is preferable to perform firing.

In order to improve wear resistance and energization stability of the film resistance heating element 3, the film resistance heating element 3 is covered on the outermost surface of the heat resistant insulating substrate 2 on the film resistance heating element 3 side. It is preferable to form an overcoat. The material used for the overcoat may be the same type of glass frit as that used for manufacturing the film-shaped resistance heating element 3.

<< Radiation / natural convection type heater 10 (FIG. 5,
(FIG. 6) >> FIG. 5 is a perspective view showing a schematic structure of a heater 10 that uses radiation and natural convection, and FIG. 6 is a vertical cross-sectional view of the heater 10. The above-mentioned sheet heating element 1 is provided in the heater body 5.
And a reflector 6 are installed, and a grid-shaped top guard 7, front guard 8, and bottom guard 9 are attached to the top, front, and bottom of the heater body 5 to prevent burns.

Infrared rays (radiant heat) H1 radiated from the sheet heating element 1 are radiated toward the front of the heater 10. At the same time, natural convection occurs in the heater body 5 due to the chimney effect. Due to this natural convection, the indoor air (cold air) H2 is sucked from the bottom surface guard 9 at the bottom of the heater body and heated. The heated air (warm air) H3 passes through the upper surface guard 7 at the upper part of the heater body and rises.

If dust or the like is accumulated on the bottom surface guard 9, the natural convection is blocked by this. When the natural convection is blocked, the temperature of the sheet heating element 1 rises, and as a result, the temperature of the film resistance heating element 3 rises. Since the film-shaped resistance heating element 3 has a positive electric resistance-temperature characteristic, its resistance value increases as the temperature rises, and as a result,
The flowing current is reduced. Therefore, as a result of self-temperature control so that the calorific value is naturally suppressed, abnormal heating is prevented.

When a towel is hung on a part of the front guard 8 or an object is placed on it to block radiation, the heat of the heat-resistant insulating substrate 2 and the film resistance heating element 3 is blocked by the radiation. It rises only for the part that was given. However, since the film-like resistance heating element 3 has a positive electric resistance-temperature characteristic as described above, the resistance value of the film-like resistance heating element 3 in the portion where the temperature rises also increases, and as a result, a plurality of film-like resistance elements are formed. In the resistance heating element 3, the electric current flowing through the film resistance heating element 3 whose temperature has risen is smaller than that of the other film resistance heating elements 3. Therefore, the electric power of the portion required to suppress excessive heat generation is selectively suppressed, and as a result,
It becomes difficult to supplement the amount of heat generated in that portion, and partial abnormal heating is suppressed.

In this way, even if the temperature of a part of the planar heating element 1 rises excessively, it is extremely safe because the temperature can be quickly uniformized. Furthermore, the rising temperature of the rising temperature and the initial uniform temperature distribution. Since it can be converted quickly, it has the advantage of being easy to use.

<< Flat Heating Element 11 for Hot Plate (FIGS. 7 and 8) >> FIGS. 7 and 8 are bottom views of the planar heating element 11 for a hot plate according to the present invention. The molding plate 12 is a heat-resistant insulating substrate made of lithia-based crystallized glass ceramics, and is used as a cooking plate. On the bottom surface of the molding plate 12, three pairs (FIG. 7) or six pairs (FIG. 8) of silver (Ag) -based electrodes 14 facing each other are provided.
And a plurality of film-like resistance heating elements 13 are all formed into a film by printing or the like. The film-like resistance heating element 13 has a positive electrical resistance that changes its resistance value in the same direction as the temperature change, like the film-like resistance heating element 3.
It has a temperature characteristic TCR.

In these sheet heating elements 11, the film-like resistance heating element 13 electrically connects 3 pairs (FIG. 7) or 6 pairs (FIG. 8) of electrodes 14 in parallel, and 3 pairs of electrodes are formed. A heating element group 15 of three groups (FIG. 7) composed of the electrodes 14 and the film resistance heating elements 13 or a heating element group 15 of 6 groups (FIG. 8) composed of six pairs of electrodes 14 and the film resistance heating elements 13 , Electrically connected in parallel. This structure is obtained by forming the electrode 14 so as to partially overlap the end portion of the film-shaped resistance heating element 13.

In the planar heating element 11 shown in FIG. 8, the electrodes 14 located between the adjacent heating element groups 15 are common electrodes between the adjacent heating element groups 15. This allows
It is possible to make the area of the electrode 14 not used for heat generation as small as possible, and as a result, it is possible to make the temperature distribution of the molding plate 12 uniform.

The sheet heating element 11 can be manufactured in the same manner as the sheet heating element 1. Further, although not shown in FIGS. 7 and 8, in order to improve the wear resistance and the energization stability of the film resistance heating element 13, the film resistance heating element 13 is provided on the bottom surface of the molding plate 12. An overcoat 21 (FIG. 14) to be described later is formed.

<< Cooking hot plate 20 (FIGS. 9 and 1)
4) >> FIG. 9 is a cross-sectional view of the cooking hot plate 20 including the planar heating element 11 shown in FIG. The planar heating element 11 is installed on the upper part of the main body 16 via a heat insulating material 17. A contact point 18 for charging is provided on the main body 16 so that the contact point 18 comes into contact with the film-shaped electrode 14 formed on the bottom surface of the sheet heating element 11.
In addition, the upper surface of the planar heating element 11 (that is, the molding plate 1
As shown in FIG. 9, the food material 19 is placed on the heating surface 2),
It can be heated. Also,
FIG. 14 is a vertical cross-sectional view of the cooking hot plate 20. As described above, the overcoat 21 for protecting the film-like resistance heating element 13 is formed on the bottom surface of the molding plate 12 so as to cover the film-like resistance heating element 13.

When a voltage is applied to the electrode 14 and the film resistance heating element 13 and the molding plate 12 generate heat,
When the food material 19 is placed on the forming plate 12, a part of the forming plate 12 is cooled and the temperature of the part is lowered. Although the temperature of the film-shaped resistance heating element 13 formed in the part where the temperature of the molding plate 12 is decreased is also decreased, since the film-shaped resistance heating element 13 has the positive electric resistance-temperature characteristic, The resistance value of the film-shaped resistance heating element 13 in the portion where the temperature is lowered is also lowered.

As a result, among the plurality of film-shaped resistance heating elements 13, a larger amount of current flows through the film-shaped resistance heating element 13 whose temperature has decreased than that of the other film-shaped resistance heating elements 13. Therefore, the electric power (that is, the calorific value) is selectively concentrated in a portion where a large amount of heat is required by being cooled by the food material 19, and as a result, the calorific value is quickly supplemented to that portion. The temperature rise will be accelerated.

As described above, even if only a part of the planar heating element 11 changes in temperature, uniform heating can be achieved so that the cooking time can be shortened, and the rising temperature of the rising temperature and the initial temperature can be reduced. There is also an advantage that it is easy to use because it can be soaked quickly.

Further, as described above, the film-shaped resistance heating element 1
Since 3 is subdivided into a plurality of heating element groups and the heating element groups 15 are electrically arranged in parallel, the heating surface has a shape close to a square as shown in FIGS. Even if the battery is installed, the distance between the electrodes can be made as short as possible. Therefore, the accuracy of selectively concentrating the amount of heat is improved. Therefore, the soaking of the molding plate 12 can be achieved with higher energy efficiency.

By the way, as shown in FIG. 14, the heat generated from the film-shaped resistance heating element 13 by energization is the conduction heat H4.
As an infrared ray (that is, a heat ray) H1, it is directly transmitted to the upper surface of the molding plate 12 as it passes through the molding plate 12 and its upper surface. Since the lithia-based crystallized glass ceramics forming the molding plate 12 is a material having infrared transparency, the infrared rays H1 radiated from the film resistance heating element 13 due to the infrared transparency of the molding plate 12 are The top surface of 12 is easily reached. Therefore, a high thermal response is realized between the bottom surface and the top surface of the forming plate 12, and the food material 19 on the forming plate 12 is provided.
Is efficiently heated by the infrared rays H1.

<< Hot plate for cooking 20a (Fig. 15) >>
FIG. 15 is a vertical sectional view of another cooking hot plate 20a. The cooking hot plate 20a is composed of a planar heating element 11a having a fluororesin film 22 formed on the upper surface of the molding plate 12, and the like, and is otherwise configured similarly to the cooking hot plate 20.

The infrared rays H1 that have passed through the molding plate 12 with high efficiency are incident on the fluororesin film 22, so that the infrared rays H1 are efficiently absorbed by the fluororesin film 22. As described above, since the infrared ray H1 is efficiently absorbed by the fluororesin film 22 due to the infrared ray transmission of the molding plate 12, the heating efficiency of the sheet heating element 11a is improved. Therefore, the food 1 on the fluororesin film 22
6 can be efficiently heated.

Further, since the fluororesin film generally has good releasability, the fluororesin film 22 prevents the food material 19 from being released.
The mold release property with respect to the food is improved, and the food material 19 is prevented from sticking. In this way, the releasing action on the food material 19 prevents the food material 19 from sticking, so that the effect of improving the cleanability of the cooking hot plate 20a is obtained.

<< Sheet heating element 31 for hot air heater (see FIG. 1
6) >> FIG. 16 is a plan view of a long piece-shaped planar heating element 31 for a warm air heater according to the present invention. Heat-resistant insulating substrate 3
Reference numeral 2 is made of lithia-based crystallized glass ceramics. A pair of silver (Ag) -based electrodes 34 facing each other and four film-like resistance heating elements 33 are provided on both surfaces of the heat-resistant insulating substrate 32.
And are formed into a film by printing or the like. The film resistance heating element 33 has a structure in which a pair of electrodes 34 are electrically connected in parallel. In this structure, the electrode 34 is partially overlapped on the end of the film resistance heating element 33. Obtained by forming.

Like the film-like resistance heating element 3, the film-like resistance heating element 33 has a positive electric resistance-temperature characteristic TCR that changes its resistance value in the same direction as the temperature change. Further, here, the same film-like resistance heating element 33 and the electrode 34 are formed on both surfaces of the heat-resistant insulating substrate 32. However, depending on the performance of the warm air heater 40 described later, these may be formed on the heat-resistant insulating substrate. It may be provided only on one side of 32.

The sheet heating element 31 can be manufactured in the same manner as the sheet heating element 1. In addition, the film resistance heating element 3
In order to improve the abrasion resistance and the energization stability of No. 3, it is preferable to form an overcoat on the outermost surface of the heat resistant insulating substrate 32 so as to cover the film-like resistance heating element 33.

<< Heater 4 for generating warm air for warm air heaters
0 >> FIG. 17 is a heater 4 for generating hot air according to the present invention.
It is a longitudinal cross-sectional view which shows the schematic structure of the warm air heater 50 in which 0 was used. The warm air heater 50 includes a front guard 36a, a warm air generating heater 40, a propeller-type blower fan 35, a rear guard 36b, and the like inside a main body 37. According to the warm air heater 50, the cool air H2 sucked from the rear guard 36b by the blower fan 35 is heat-exchanged by the warm air generating heater 40, and the warm air H3 is discharged from the front guard 36a.
Will be blown out.

The heater 40 for generating warm air has a structure in which seven sheet heating elements 31 in the form of long pieces are used and arranged in a louver shape at regular intervals, and are electrically connected in parallel. Since the film-like resistance heating element 33 has the positive electric resistance-temperature characteristic as described above, the electric power rises when the blast temperature is low, and conversely the room temperature rises and the blast temperature rises. When the temperature becomes low, the self-temperature control is performed so that the power is reduced.

Next, the sheet heating element 31 which constitutes the louver.
Each of the mechanisms that rotate about the longitudinal direction will be described. FIG. 18 is a cross-sectional view showing the structure of the main part of the rotating mechanism for one sheet of heat generating element 31. Heat-resistant insulating substrate 3
The electrodes 34 formed on both sides of the plate 2 are the leaf spring terminals 41.
It is sandwiched between. A pin 43 is erected at the center of the leaf spring terminal 41. The pin 43 is pivotally supported by the support plate 42 so that the leaf spring terminal 41 can rotate about the pin 43.

FIG. 19 shows the pivoting operation of the leaf spring terminal 41 as seen from the side of the short side of the sheet heating element 31 (FIG. 18). The rotating mechanism shown in FIG. 18 is similarly configured for all the sheet heating elements 31. Also,
A lever 44 attached to the leaf spring terminals 41 in the same structure as the support plate 42 allows all the leaf spring terminals 41 to be
At the same time, the force is added. If the lever 44 is moved up and down while the support plate 42 is fixed, the same figure
As shown in (A) and (B), the leaf spring terminal 41 rotates about the pin 43. Since the leaf spring terminal 41 sandwiches the sheet heating element 31, it is possible to freely rotate the sheet heating element 31 as a louver about its longitudinal direction by operating the lever 44.

If the sheet heating element 31 is pivotally set to a certain angular position by operating the lever 44 up and down, the warm air heated by the warm air generating heater 40 is horizontally moved.
It is possible to freely blow air at a desired angle in {FIG. 19 (A)}, upward direction, downward direction {FIG. 19 (B)} and the like. Hot air heater 5
Since a user of 0 can send the hot air in a desired direction by controlling the air blowing direction, it can be said that this hot air generating heater is an optimal heater for a hot air heater.

Further, according to the structure of the hot air generating heater 40, the sheet heating elements 31 are arranged in a louver shape, so that the pressure loss at the time of blowing air is small, and therefore, the reduction in air volume due to the pressure loss is also small. Therefore, it is possible to efficiently generate hot air and easily obtain an appropriate amount of hot air. In addition, since the sheet heating elements 31 are simply arranged in a louver shape, the required power, heat quantity, air volume, and warm air can be changed by changing the shape, the number, and the interval of the sheet heating elements 31. The temperature and the characteristics of the blower fan 35 can be easily adjusted at low cost.

Further, since the sheet heating elements 31 provided with the film-like resistance heating elements 33 are electrically connected in parallel, even if the positional or temporal air volume balance during air blowing is lost, each sheet heating is generated. The blast temperature self-recovers due to the heating balance of the body 31, and as a result, the temperature change is suppressed. That is, when the temperature of each of the film-shaped resistance heating elements 33 is lowered for some reason, the resistance value is reduced and a large amount of current flows. As a result, the power consumption is increased and the temperature reduction is suppressed, and conversely,
When the temperature rises for some reason, the resistance value rises and it becomes difficult for current to flow. As a result, the power consumption is reduced and the temperature rise is suppressed. In this way, each sheet heating element 3
Since the self-temperature control is performed by 1, it is possible to easily obtain hot air having an appropriate temperature.

<< Sheet heating element 31a for warm air heater having deodorizing function (FIG. 20) >> FIG. 20 is a vertical cross-sectional view of a long sheet heating element 31a having a deodorizing function. In the sheet heating element 31a, an overcoat layer 45 containing glass frit as a main component is formed on the surface of the film resistance heating element 33, and a catalyst layer 46 for deodorization is formed on the outermost surface. It is a thing. The catalyst layer 46 is composed of an adsorbent having a high deodorizing effect such as copper ion-exchanged zeolite, a manganese oxide-based or noble metal-based oxidation catalyst, and an inorganic binder such as silica sol or alumina sol. The adsorbent exerts a deodorizing effect by adsorbing the odorous component at room temperature, and the oxidation catalyst exerts a deodorizing effect by oxidizing and decomposing the odorous component when heated at 200 ° C. or higher. Further, the oxidation catalyst can also serve to oxidize and decompose the odorous components adsorbed by the adsorbent.

<< Example of use of sheet heating element 31a >> The sheet heating element 31a having the deodorizing function is used to configure the warm air generating heater 40 shown in FIG. An example of use when applied will be described.

When heating is not required, the hot air generating heater 40 is not energized and only the blower fan 35 is operated. When the air containing various odors passes through the warm air generating heater 40, the air is deodorized by coming into contact with and adsorbing the adsorbent of the catalyst layer 46 formed on the outermost surface of the planar heating element 31a. If deodorization is continued for a certain period of time, the adsorbent will break through and the deodorizing effect will decrease. At this time, blower fan 3
5, the hot air generating heater 40 is energized for 1 to 2 minutes to raise the temperature of the sheet heating element 31a to about 300 ° C. Then, the odorous components adsorbed on the adsorbent are decomposed by the oxidation catalyst, and the air is deodorized and released from the adsorbent. On the other hand, the adsorbent is activated again to recover the deodorizing performance.

When heating is required, the warm air generating heater 40 and the blower fan 35 are simultaneously operated. At this time, the oxidation catalyst is heated by the sheet heating element 31a together with the air containing the odorous component. For this reason, the odorous components adsorbed on the oxidation catalyst are oxidized and deodorized (decomposed), and the odorous components in the blown air are brought into contact with the oxidation catalyst to be oxidatively deodorized (decomposed). Therefore, the warm air H3 blown out from the front guard 36a is
It will be odorless.

As described above, if the heater 40 for generating hot air is used, not only warm air heating but also deodorization can be performed at room temperature and during heating. Therefore, it can be said that the warm air heater 50 using the warm air generating heater 40 is an extremely useful low cost heater that also serves as a deodorizer. In the above-described conventional heater for generating hot air, aluminum is used as the material of the radiator, so even if the catalyst layer for deodorization is coated on the radiator, the catalyst layer does not adhere to the radiator. Therefore, even if the conventional heater for generating hot air is used, the heater cannot have a deodorizing function that operates simultaneously with the generation of hot air.

[0059]

EXAMPLES Hereinafter, the sheet heating element and the heater for generating hot air according to the present invention will be described more specifically with reference to Examples and Experimental Examples.

<< Electrical resistance-temperature characteristic TCR of film-like resistance heating element (FIG. 4) >> FIG. 4 shows a film-like film made of various conductive materials when a heat-resistant insulating substrate made of lithia-based crystallized glass ceramics is used. Electric resistance of resistance heating element-Temperature characteristic T
An example of CR is shown as a graph. The electric resistance-temperature characteristic TCR of each film resistance heating element is 0.65% / ° C for nickel (Ni) based film, 0.35% / ° C for silver (Ag) based film, and ruthenium oxide (RuO ₂ ) based film for TCR. -0.02% / ° C, Nichrome wire 0.02% / ° C.

<< Relationship between compounding ratio of film-like resistance heating element and sheet resistance (Table 1) >> Nickel (Ni) particles (flake-like particles) and glass frit are used as materials for the film-like resistance heating element. Table 1 shows the relationship between these weight compounding ratios and sheet resistance, taking the case of use as an example.

[0062]

[Table 1]

<< Flat heating element 1 for heater (Fig. 2) >> Heat-resistant insulating substrate 2 made of lithia-based crystallized glass ceramics
Two electrodes 4 were formed 220 mm apart on the surface (width 500 mm, height 250 mm, thickness 3 mm). A film-like resistance heating element 3 consisting of a Ni-based film (surface resistance: 80 mΩ / □) between two electrodes 4.
Ten (one width: 2 mm, length: 1820 mm) print patterns were formed as shown in FIG. The interelectrode resistance was 7.3Ω. When a voltage of 100 V is applied between the electrodes 4, the initial current is 13.7 A (power 1370 W), and then the current value gradually decreases as the temperature of the sheet heating element 1 rises, and a few minutes later. Stabilized. The current value at this time was 6 A (electric power 600 W), and the surface average temperature was about 220 to 230 ° C.

<< Sheet heating element 11 for hot plate (FIGS. 8 and 9) >> Molding plate 12 made of lithia-based crystallized glass ceramics (bottom size: 300 mm length × 300 mm width ×)
Six film-like resistance heating elements 13 (one length: 46 mm, width: 1.5 mm) are electrically connected in parallel between the pair of electrodes 14 on the bottom surface of thickness 5 mm, heating area: 260 mm x 260 mm). And the printed pattern was formed so that the six pairs of electrodes 14 were electrically parallel. The interelectrode resistance was 8.3Ω.
As a conductive material for the film-shaped resistance heating element 13, a mixture of silver and tin oxide particles was used. When the film thickness is 15 μm, the sheet resistance is 0.
58Ω / □, electric resistance-temperature characteristic TCR was 0.35% / ℃.

<< Changes in Resistance Value, Power, and Mold Plate Surface Temperature with Time (FIG. 10) >> FIG.
The sheet-like heating element 11 using the film-like resistance heating element 13 having CR of 0.35% / ° C. and the electric resistance-temperature characteristic TCR of 0
% / ° C. of a sheet-like resistance heating element using a sheet-like resistance heating element, (A) resistance value of the film-like resistance heating element 13 with respect to time, (B) electric power, and (C) surface temperature of the molding plate 12.
(Hereinafter, referred to as “plate temperature”).

Electrode 1 formed on molded plate 12
When a voltage of 100 V was applied between the four, a current of about 12 A (power 1200 W) flowed. The current value decreased as the temperature of the molding plate 12 increased, and stabilized at about 6 A (electric power 600 W). The plate temperature at this time was about 250 ° C. on average. When the food material 19 such as meat is placed on the entire surface of the molding plate 12 in this stable plate temperature state (h1), the plate temperature drops to about 120 ° C., and the current value is about 9 A (electric power of about 900 A).
W). After that, the current value decreased as the plate temperature increased. In addition, when the food 19 such as meat was placed on a part of the surface of the molding plate 12 (h2) while the plate temperature was stable at 250 ° C., the current value was about 7.
It has risen to 5A (power 750W).

It can be seen from FIG. 10 that immediately after the voltage is first applied, the plate temperature is low, so a large amount of power is consumed and the rise of the plate temperature is promoted. However, when the plate temperature rises, the power consumption is automatically suppressed. I understand. That is, if the hot plate 20 for cooking provided with the sheet heating element 11 is used, cooking can be started promptly.

Further, from FIG. 10, when the food material 19 is placed on the surface of the molding plate 12, the plate temperature is lowered (that is, the temperature of the film-like resistance heating element 13 is decreased), so that the film-like resistance heating element 13 is It can be seen that the resistance value decreases and the power automatically increases to promote the plate temperature increase. The increase in electric power at this time is due to the electric power of the film-like resistance heating element 13 formed in the portion where the plate temperature has decreased being more intensive than the other film-like resistance heating elements 13. In this way, each film-shaped resistance heating element 13
The self-temperature control of makes cooking easier and
Cooking time is reduced.

<< Film-shaped resistance heating element 1 for hot plate
3 circuit configuration (FIG. 11) >> FIG. 11 shows a film resistance heating element 1
3 (FIG. 8) schematically shows the electric circuit configuration. When the plate temperature is stable at 250 ° C, the film resistance heating element 1
The resistance value of each of 3a to 13m is about 600Ω, and the power is 16.
It was 7W.

Using the circuit diagram of FIG. 11, the molding plate 1
The electric power change when the food material 19 is placed on a part of the surface of No. 2 and the temperature of a part of the film-shaped resistance heating element 13 is lowered and the resistance value is decreased will be described. For example, the film resistance heating element 13
When the temperature of a to 13d drops to 100 ° C, the resistance value of each of the film-shaped resistance heating elements 13a to 13d becomes 390.
Ω, power is 25.6W. As described above, since the power density is significantly higher than the power of 16.7 W in the other film-shaped resistance heating elements 12e to 12m, the plate temperature rise is promoted and the temperature suitable for the food material 19 is quickly returned.

<< Wavelength-Infrared Transmittance Characteristic of Molded Plate 12 >> FIG. 12 is a graph showing the wavelength-infrared transmittance of the lithia white crystallized glass ceramics.
FIG. 4 is a graph showing wavelength-infrared transmittance of lithia-based transparent crystallized glass ceramics. It is understood that any of the lithia-based crystallized glass ceramics transmits infrared rays, but in particular, the lithia-based transparent glass ceramics transmits infrared rays well.

<< Flat heating element 31 for warm air heater >> Long sheet heating element 31 (Dimension of heat resistant insulating substrate 32: length 170)
mm, width 40 mm, thickness 3 mm; dimensions of heat generating part: length 150 mm, width 30
mm), the film-like resistance heating element 33 was formed on both surfaces of the heat resistant insulating substrate 32 so that 70 W of electric power was generated when a voltage of 100 V was applied between the pair of electrodes 34. Air flow rate 1m ³ / m
In, with a total power of about 1000W, it was possible to generate hot air with a temperature of about 80 ° C. At this time, the surface temperature of the sheet heating element 31 was about 300 ° C.

<< Deodorizing Effect of Warm Air Heater 50 >> Using a hot air heater (FIG. 17) equipped with a sheet-shaped sheet heating element 31a (FIG. 20) having a catalyst layer The one-pass removal rate of acetic acid odor when deodorizing was performed was measured. FIG. 21 shows the measurement results in a graph of SV (space velocity) value-removal rate. Similar results were obtained at both room temperature and heating. The removal rate and the SV value are defined by the following equations (1) and (2). [Removal rate] = ([Original gas concentration]-[Concentration at the outlet]) / [Original gas concentration] ... (1) [SV value] = [Air flow rate per hour] / [For generating hot air] Volume of heater] …… (2)

[0074]

As described above, according to the first to third inventions, the positive electric resistance of the film-like resistance heating element is-
Since the self-temperature control is performed according to the temperature characteristics, even if only a part of the heating element changes in temperature, it is possible to quickly achieve soaking. Further, the rising temperature of the rising temperature and the initial soaking can be performed quickly. Therefore, it is possible to realize a sheet heating element having excellent safety and usability.

According to the second aspect of the invention, the accuracy of selectively concentrating the amount of heat is improved by the plurality of heating element groups electrically connected in parallel, so that the above-mentioned soaking can be achieved with higher energy efficiency. You can

According to the third aspect of the invention, since the heat resistant insulating substrate has infrared transparency, it is possible to realize a high thermal response between one surface and the other surface of the heat resistant insulating substrate. You can Moreover, since infrared rays are efficiently absorbed by the fluororesin film, there is an effect that the heating efficiency of the sheet heating element is improved. In particular, when applied to a cooking plate, the fluororesin film prevents the food from sticking to the food, and therefore has the effect of improving the cleanability of the cooking plate by releasing the food.

According to the fourth to sixth aspects of the invention, since the above-mentioned self-temperature control is performed by the sheet heating elements electrically connected in parallel, it is possible to easily obtain the warm air of an appropriate temperature. Moreover, since the pressure loss is suppressed to a small level by the planar heating elements arranged in a louver shape, it is possible to efficiently generate hot air and easily obtain an appropriate amount of hot air. Moreover, since the structure is simple, it can be realized at low cost.

According to the heater for generating warm air according to the fifth aspect of the invention, not only warm air heating but also heating at room temperature are achieved by the combination of the adsorbent formed on the outermost surface of the sheet heating element and the oxidation catalyst. Deodorization can be performed even at times. Therefore, it is possible to realize an extremely useful low-cost warm air heater that also serves as a deodorizer.

According to the sixth aspect of the present invention, the user can control the air blowing direction and send the warm air in a desired direction. Therefore, the heater for generating warm air according to the present invention is optimal as a heater for a warm air heater.

[Brief description of drawings]

FIG. 1 is a plan view showing a planar heating element for a heater according to the present invention.

FIG. 2 is a plan view showing another planar heating element for a heater according to the present invention.

FIG. 3 is a plan view showing another planar heating element for a heater according to the present invention.

FIG. 4 is a graph showing electric resistance-temperature characteristics of a film resistance heating element obtained by using various conductive materials.

FIG. 5 is a perspective view showing a radiant / natural convection type heater including a sheet heating element embodying the present invention.

6 is a vertical cross-sectional view of the heater shown in FIG.

FIG. 7 is a bottom view showing a planar heating element for a cooker embodying the present invention.

FIG. 8 is a bottom view showing a planar heating element for another cooking machine embodying the present invention.

9 is a cross-sectional view showing a cooking hot plate including the planar heating element shown in FIG.

10 is a graph showing the relationship between the resistance value, the electric power, and the plate temperature with the passage of time in the planar heating element shown in FIG.

FIG. 11 is a circuit diagram schematically showing an electric circuit configuration of the film resistance heating element shown in FIG.

FIG. 12 is a graph showing wavelength-infrared transmittance of lithia-based white crystallized glass ceramics.

FIG. 13 is a graph showing wavelength-infrared transmittance of lithia-based transparent crystallized glass ceramics.

14 is a cross-sectional view of a main part of the sheet heating element shown in FIG.

FIG. 15 is a sectional view of an essential part of a sheet heating element having a fluororesin film formed on the surface of a molding plate.

FIG. 16 is a plan view showing a planar heating element for a warm air heater according to the present invention.

FIG. 17 is a vertical cross-sectional view showing a schematic structure of a warm air heater including a heater for generating warm air including the sheet heating element shown in FIG.

18 is a vertical cross-sectional view showing the structure of the main part of the rotating mechanism of the sheet heating element used in the heater for generating warm air in FIG.

FIG. 19 is a view showing the pivoting operation of the leaf spring terminal seen from the side surface side of the short side of the sheet heating element shown in FIG. 18;

FIG. 20 is a vertical cross-sectional view showing a planar heating element for a warm air heater having a deodorizing function.

21 is a graph showing the deodorizing effect (SV value-removal rate) on acetic acid gas in the warm air heater including the sheet heating element shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet heating element 2 Heat-resistant insulating substrate 3 Film resistance heating element 4 Electrode 10 Heating device 11 Sheet heating element 11a Sheet heating element 12 Forming plate 13 Sheet resistance heating element 14 Electrode 15 Heating element group 20 Cooking hot Plate 20a Cooking hot plate 21 Overcoat 22 Fluorocarbon resin film 31 Sheet heating element 31a Sheet heating element 32 Heat resistant insulating substrate 33 Film resistance heating element 34 Electrode 40 Hot air generating heater 45 Overcoat layer 46 Catalyst layer 50 Hot air heater

Claims (6)

[Claims] 1. A planar heating element comprising an electrode pair and a plurality of film-shaped resistance heating elements electrically connecting the electrode pairs in parallel on a heat-resistant insulating substrate. A planar heating element having a positive electric resistance-temperature characteristic in which a body changes its resistance value in the same direction as a change in temperature. 2. The heat-resistant insulating substrate according to claim 1, wherein a plurality of heating element groups each including the electrode pair and the film-like resistance heating element are electrically arranged in parallel. Sheet heating element. 3. A substrate having infrared transparency is used as the heat-resistant insulating substrate, the electrode pair and a film-like resistance heating element are formed on one surface of the substrate, and a fluororesin film is formed on the other surface. The sheet heating element according to claim 1 or 2, characterized in that. 4. A heater for generating warm air, comprising a plurality of sheet heating elements according to claim 1 or 2 arranged in a louver shape and electrically connected in parallel. 5. A deodorizing function is provided by forming a film of an adsorbent and an oxidation catalyst with an inorganic binder on the outermost surface of the planar heating elements arranged in a louver shape. The heater for generating the warm air described. 6. The heater for generating warm air according to claim 4, wherein the planar heating elements arranged in a louver shape are movably provided to have a rectifying function.