JP3201570B2 - High frequency electromagnetic induction heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency electromagnetic induction heater useful for heating furnaces or charcoal-grilled dishes, and more particularly to fish and shellfish, meat, vegetables, mushrooms, pizza,
The present invention relates to a high-frequency electromagnetic induction heater useful for a high-frequency electromagnetic cooker used for baking gratin or the like with synchrotron radiation.

[0002]

2. Description of the Related Art Heretofore, grilled foods have been best prepared with charcoal fire using natural charcoal. For example, eel kabayaki cannot be tasted good without charcoal fire. Not only eel,
The best restaurants use charcoal fire to taste good fish, shellfish and meat. The reason why the charcoal fire is used is that the radiant heat of the charcoal fire due to the infrared rays is excellent in heat permeability to the cooked object to be heated and can generate uniform heat. However, in order to generate uniform heat, charcoal obtained from hard wood such as oak is used, the arrangement of the charcoal fire is devised, and smoke generated by liquid dropped from the cooked food is eliminated by a fan during cooking. In addition, it was necessary to take measures such as removing the ash generated on the surface of the charcoal fire, and many years of training and skill were required to become a top-class cook. Besides,
Because good quality charcoal is difficult to obtain and handling the charcoal itself is cumbersome, charcoal is becoming increasingly unused.

[0003] In restaurants and homes where it is not required to give a very first-class taste due to cost considerations, grilling is performed by using a resistance-type electric oven or by heating a metal object by burning gas and reflecting it. It is common practice to bake food materials (food ingredients) with heat.

Further, firing furnaces for ceramics and the like, mold heating furnaces for synthetic fibers, and general heating furnaces are heated to a constant heating temperature over a long period of time by using a resistance heater such as a nichrome wire.

[0005]

However, the cooking using the electric oven of the above resistance type does not generate a large amount of heat, requires a long time to elevate the temperature to a constant heating temperature, and requires a long time for cooking. However, it took a long time, and there was a problem that the fire did not pass well through the inside of the food. In addition, cooking by gas combustion has a problem that the fire does not well pass through the inside of the food. In particular, with a conventional cooker, it was difficult to obtain a high heat. Further, there is a problem that a general heating furnace also requires a long time to elevate the temperature to a certain heating temperature. Further, the present inventors have already proposed a disk-shaped metal heating member having a slit hole extending in a circumferential direction as a heating element used in a high-frequency electromagnetic induction heater (Japanese Patent Application No. 6-238666). However, in the case where the disk-shaped metal heating member is to be cooked with a body to be heated on top, there is a problem that if a liquid such as oil or fat falls from the body to be heated, smoke or ignition is likely to occur.

In order to solve the above-mentioned problems of the prior art, the present invention is capable of heating with radiant heat rays including visible light or infrared rays using high-frequency power, has a fast heating rate, and when applied to a cooker, is a pottery. An object of the present invention is to provide a high-frequency electromagnetic induction heater which can be cooked and which can be a high-frequency electromagnetic cooker excellent in heat uniformity, and which does not easily generate smoke or fire even when a liquid such as oil or fat falls from a heated object. And

[0007]

In order to achieve the above object, a high frequency electromagnetic induction heater according to the present invention comprises a work coil for generating a high frequency, a metal heating member heated by an AC magnetic field generated by the high frequency, At least means for thermally insulating the work coil and the metal heating member is provided , and heating means is provided by radiant heat rays generated from the metal heating member.
A high-frequency electromagnetic induction heater for heat cooking , wherein the metal heating member is constituted by a plurality of cylindrical strips having different diameters.
The axial direction of the plurality of cylindrical strips is the same as that of the food.
Qualitatively located vertically, the insulation means
Top plate on the top coil and on the top plate
A heat insulating material plate installed through a spacer to the
Blow air into the gap between the top plate and the insulation plate
It is characterized by being constituted by means .

[0008] In the above configuration, it is preferable that the plurality of cylindrical strips are fixed at fixed intervals by a fixing device.

In the above structure, the plurality of cylindrical strips are preferably non-magnetic or magnetic stainless steel having a width of 3 to 20 mm and a thickness of 0.1 to 1 mm. Further, in the above configuration, the heat generation temperature of the metal heating member is preferably in the range of 700 to 1000 ° C.

In the above structure, it is preferable that the heat generated by the metal heating member includes visible light or infrared light.
Further, in the above configuration, it is preferable that the generated frequency of the work coil is in a range of 20 to 30 kHz.

[0011]

[0012] In the above structure, the high-frequency electromagnetic induction heater is preferably a high-frequency electromagnetic cooker.

[0013]

According to the present invention described above, a work coil for generating a high frequency, a metal heating member heated by an AC magnetic field generated by the high frequency, and a heat insulation between the work coil and the metal heating member. A high-frequency electromagnetic induction heater provided with at least a means for performing the above-mentioned steps, wherein the metal heating member is composed of a plurality of cylindrical strips having different diameters, so that the cylindrical strip can be efficiently heated by electromagnetic heating ( Fever). In addition, the heating surface can be effectively utilized, and even if a liquid such as oil or fat falls from the object to be heated, the probability of falling into the cylindrical strip is low. Smoke and ignition are less likely to occur. Further, even if the metal heating member rapidly expands to a high temperature at which a radiant heat ray is generated, the metal heating member does not undergo thermal deformation and can stably maintain a cylindrical shape. In addition, when the shape is cylindrical, both the front surface (flat surface) and the back surface can contribute to heating, and radiant heat rays can be generated most efficiently. As a result, it is possible to provide a high-frequency electromagnetic cooker excellent in heat uniformity suitable for grilled cooking. In addition, since electric power is used as an energy source, temperature control is easy, and the cooking environment can be much cleaner than that of charcoal or gas combustion. Further, even when applied to a general heating furnace, the temperature can be raised to a temperature of several hundred degrees within a few minutes, so that the rate of temperature rise is extremely high.

Considering the reason why the radiant heat ray can be efficiently generated in the above description, the magnetic flux rises like a tornado upward from the work coil. However, a plurality of ring-shaped metal heating members (heating members) of the present invention are used. ), Which causes a short-circuit current to flow and generate Joule heat.

[0015] In the above structure, when the plurality of cylindrical strips are fixed at fixed intervals by a fixing device,
This is preferable because uniform heating can be performed. Further, in the above configuration, when the axial direction of the plurality of cylindrical strips is positioned substantially perpendicular to the object to be heated, even if a liquid such as oil or fat falls from the object to be heated, smoke or ignition may occur. It is difficult to occur and is preferable.

In the above structure, when the plurality of cylindrical strips are made of non-magnetic or magnetic stainless steel having a width of 3 to 20 mm and a thickness of 0.1 to 1 mm, the heat generation efficiency is high, and Various liquids (oils and fats, seasonings, etc.) generated from foodstuffs or related materials with excellent oxidation resistance at high temperatures
Can be used stably for a long time without deterioration even when contacted at high temperature. Further, since the radiant heat ray generated by the present invention requires a heat ray amount, the thickness of the metal heating member is not so necessary, and a thickness of about 0.1 to 1 mm is sufficient. More preferably, 0.3 to 0.8 m
m. Examples of the stainless steel include austenitic stainless steel such as SUS304.

In the above, according to the preferred example in which the heat generation temperature of the metal heating member is in the range of 700 to 1000 ° C., radiant heat rays can be sufficiently generated practically.
Further, in the above, according to a preferred example in which the heat generated by the metal heating member includes visible light or infrared light, radiant heat rays including yellow, orange (orange), red, and the like can be sufficiently generated practically. That is, heat generation equal to or higher than that of high-grade charcoal fire can be generated. More specifically, the wavelength is 0.75 to 1
A radiant heat ray including near infrared rays, middle infrared rays, and far infrared rays of about 00 μm can be generated.

In the above, according to the preferred example in which the frequency of generation of the work coil is in the range of 20 to 30 kHz, radiated heat rays can be sufficiently generated practically.
The input electric capacity is suitable for, for example, a commercial cooker of about 3.0 to 5.0 kW.

In the above, the means for thermally insulating the work coil and the metal heating member includes a top plate on the work coil, a heat insulating material plate installed on the top plate via a spacer, a top plate and a heat insulating material plate. because of consisting of means for blowing air into the gap can operate the heating device efficiently stably for a long period of time.

The high-frequency electromagnetic induction heater of the present invention can also be used as a heating furnace. When used also as a heating furnace, it may be used in an atmosphere of an inert gas such as nitrogen.
In addition, when used as a heating furnace, replacement work such as attachment and removal of a metal heating member (heating element) is easy.

The high-frequency electromagnetic induction heater of the present invention is preferably used particularly for a high-frequency electromagnetic cooker.

[0022]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. FIG. 1 is a perspective view of a metal heating member (heating member) 6 of the high-frequency electromagnetic induction heater according to the present invention. As a material of the metal heating member (heat generating member) 6, non-magnetic stainless steel includes austenitic stainless steel such as SUS304. As magnetic stainless steel,
For example, NAR16 manufactured by Sumitomo Metal Technology Co., Ltd.
0, FH-11 and the like. In this embodiment, SUS304 is used, and is constituted by a plurality of narrow strips 19 having a width of 7 mm and a thickness of 0.5 mm. The narrow band body 19 is fixed at the connecting portion 20 by welding or pressure welding and has a cylindrical shape. Then, it is fixed at a constant interval by a cross-shaped fixing device 21 having slits formed at a constant interval. In this embodiment, the inner diameter of the innermost cylindrical strip is 52 mm, and the inner diameter of the outermost cylindrical strip is 205 m using the fixing device 21.
m, and a total of 10 cylindrical strips were arranged.

FIG. 2 is a schematic view showing one embodiment of the high-frequency electromagnetic cooker according to the present invention. As shown in FIG.
A ceramic top plate 2 is fixed to an upper portion of the upper portion, and a high frequency power generator well known to those skilled in the art is provided below the top plate 2. FIG. 2 illustrates the work coil 3 of the inverter and omits other high-frequency power generators. However, the high-frequency power generator uses a commercial wave number (50 Hz or 60H) via an AC power supply.
z, 3.0 to 5.0 kW), converts the DC power into DC current, generates high frequency power (for example, 25 kHz) from the work coil 3 using an inverter and an output transformer, An alternating magnetic field is generated. Here, the top plate 2 has a role of protecting the inverter.

5-10 m above the top plate 2
A heat insulating material 5 is provided via ceramic spacers 4 and 4 having a thickness of m, and a metal heating member (heating member) 6 is mounted on the heat insulating material 5. As a result, an electromotive force is induced in the metal heating member (heating member) 6 by the action of the AC magnetic field generated above the top plate 2 by the work coil 3, and Joule heat is generated by an eddy current flowing through the surface layer of the metal heating member. The heating member (heating member) 6 is heated. The metal heating member (heat generating member) 6 emits radiant heat rays including visible light and infrared light, and cooks fish and shellfish, beef, etc. placed at a certain distance above the metal heating member (heat generating member) 6. Can be.

On the top plate 2, a cooling fan 7 is provided on the side of the heat insulating material 5. The cooling fan 7 sends cool air between the heat insulating material 5 and the top plate 2. Can be. Then, the heat radiated downward from the heat insulating material 5 is cooled by the operation of the cooling fan 7, and the work coil 3 does not become hot, so that the work coil 3 can be prevented from being damaged.
As described above, since the work coil 3 is prevented from being damaged by the cooling fan 7, the work coil of the inverter can be protected without turning off the entire apparatus as in the related art. You can cook well if you need to.

The side wall 5a of the heat insulating material 5 has a diameter of 1.2 mm.
Is wound about 1 to 20 times to form an antenna coil 8. Thereby, the magnetic flux leaking around the heat insulating material 5 links the antenna coil 8 and generates an electromotive force in the antenna coil 8, so that an alternating current can be obtained.

As shown in FIG. 3, the antenna coil 8 is connected to a DC through a silicon rectifier 9 and a smoothing capacitor 10.
It is connected to the motor 11. Incidentally, in FIG.
Is a resistor for circuit protection.

With the above configuration, the alternating current obtained by the antenna coil 8 is
And full-wave rectified through the smoothing capacitor 10,
Since a direct current of up to 30 V can be obtained, the DC motor 1
1 can be driven to operate the cooling fan 7.
Of course, the cooling fan 7 may be connected to another power supply.

As described above, since the cooling fan 7 is operated using the magnetic flux leaking around the heat insulating material 5, no external power supply is required. As a result, the power cord does not hang from the electromagnetic cooker, the appearance of the electromagnetic cooker becomes cleaner, and power can be saved. Also, the power cord does not hinder the cleaning of the electromagnetic cooker, and there is no problem in transporting it to another place.

Although the cooling fan 7 is provided on the top plate 2 in this embodiment, the invention is not necessarily limited to this configuration. Cold air may be sent between the top plate 2 and the work coil 3.

In this embodiment, the antenna coil 8 is formed by winding an aluminum wire around the side wall 5a of the heat insulating material 5 provided on the top plate 2, but is not necessarily limited to this structure. Alternatively, an antenna coil may be provided around the heat insulating material 5 independently of the heat insulating material 5. In this case, the metal heating member does not need to be in the form of a container like the heat insulating material 5, but may be in the form of, for example, a flat plate or a sheet.

Further, in the present embodiment, the cooling fan 7 is operated by utilizing the leakage magnetic flux. However, the present invention is not necessarily limited to this configuration. The cooling fan 7 may be operated by connecting the DC motor 11 via a thermocouple and adjusting the generated electromotive force to a driving voltage suitable for the DC motor 11. Further, the cooling fan 7 can be operated using another external power supply.

FIG. 4 is a schematic view showing another embodiment of the high-frequency electromagnetic cooker according to the present invention. What is different from FIG. 2 is the part that sends out the cooling air. That is, a fan 13 is provided inside the main body 1 to cool the work coil 3, and at the same time, a cooling wind is passed through the hood 15 from a cooling hole 14 opened at the end of the top plate 2 to cool the work coil 3.
This is a part that cools the space between the heat insulator 5.

FIG. 5 is a schematic view showing still another embodiment of the high-frequency electromagnetic cooker according to the present invention. 2 is different from FIG. 2 in that the fan 17 is placed sideways beside the heat insulating plate 16 and the top plate 2 and the heat insulating plate 16
It is about to cool between. In this way, the fan 17 does not hinder the cooking for the user, and the metal heating member (heat generating member) 6 is easy to see. If the motor for rotating the fan 17 (not shown because it is thin) is placed downward, it is easier for the user to use. In this embodiment, the antenna coil is located outside the metal heating member (heating member) 6 and below the heat insulating plate 16.
Wind up to 6 times. Since the antenna coil is thin, it does not obstruct the air flow from the fan 17. In addition,
The space (interval) between the top plate 2 and the heat insulating material plate 16 is preferably about 5 mm.

In the above, as the heat insulating material plate 16, for example, an inorganic material heat insulating sheet such as a board made of silica-based ceramic fiber such as a kao wool board (manufactured by Isolite Industries) and a kao wool 1000 board (manufactured by Isolite Industries) is used. Is preferred. In FIG. 5, reference numeral 18 denotes a center spacer.

Next, FIG. 6 shows the shape of the heat insulating material plate 16. As the heat insulating material plate 16, a kao wool board or a kao wool 1000 board was used as described above, and a square plate having a thickness of 5 mm and a side of 240 mm was used after debinding treatment. The binder removal treatment is performed in order to eliminate an unusual odor, and was performed by heat treatment at 700 to 800 ° C. A hole 18 'for passing the center spacer 18 was formed in the center.

Next, FIG. 7 shows that the wire mesh 2 is placed on the heating device of FIG.
3 (the distance between the wire mesh 23 and the metal heating member (heating member) 24 is about 20 to 120 mm, and in the case of a raw fish, it is about 80 m
m, about 20 mm for dry matter, 80-100 mm for shellfish,
This is an example of an experiment in which a suction duct 22 is provided around a metal heating member (heat generating member), and a fish 24 is actually grilled. The input electric capacity was 200 V, 4.0 kW, and the generation frequency of the work coil 3 was 25 kHz. Under these conditions, the heating temperature of the metal heating member (heating member) 6 can be raised to 820 ° C. in 1 minute 20 seconds to 1 minute 30 seconds, and yellow, orange (orange),
Visible and infrared radiant heat rays, including red, were generated. The fish 24 was sufficiently heated to the inside without burning the surface, and could cook as good as or better than the case using a high-grade charcoal fire. The liquid 25 that falls from the fish 24 rarely falls directly on the metal heating member (heating member) 6.
Even if it fell, it was repelled, preventing both smoke and fire. At the same time, air is sent between the top plate 2 and the heat insulating material 5 using the cooling fan 17, and at the same time, air is sent also onto the metal heating member (heat generating member) 6, and the suction duct 22.
Aspirated. As a result, the metal heating member (heating member) 6
The oils and fats that fell during the process became gasified by the high temperature and were sucked into the suction duct 22, and no smoke was found to the outside. Further, the metal heating member (heating member) 6 was not contaminated. In addition to fish, shellfish such as turban shells, crabs, shrimp, eel, etc. were also cooked, but the outside did not burn or become black, and the inside was sufficiently heated to the same extent as when using high-grade charcoal fire. I was able to cook better. I also baked beef, chicken, yakitori, etc., but the surface did not burn and the inside was heated enough to cook well. The above-mentioned cooking was done by top-class cooks, but they were able to cook at the same level as charcoal or over charcoal. After repeated use for one month, the metal heating member (heating member) 6 was not deformed or oxidized.

Next, using the apparatus shown in FIG. 7, an experiment was conducted to determine the specific amount of heat generated by heating water. The pot used was a black pot with a black surface. Two liters of water at 25 ° C. was put therein, the position of the gantry was changed to 20 mm above the metal heating member (heating member) 6, a wire net was placed on the gantry, and a pan was placed on the wire net. After heating for 10 minutes, the temperature of the heating plate 6, the temperature when stirring the water in the pan, and the temperature of the wire mesh on the gantry were measured. As the metal heating member (heating member) 6, SUS304 stainless steel, NAR160 stainless steel, and FH-11 stainless steel were used. As a result, the temperature of the heating plate was 820-910 ° C, and the water temperature was 91-97 ° C.

From the above results, it was confirmed that the thermal power was strong. It was also found that rapid heating was possible. Next, FIG.
Shows another embodiment of the present invention, in which the work coil 3 and the top plate 2 are placed on the upper side, and the heat insulating material plate 16 and the metal heating member (heating member) 6 are installed above the heating box 26. Things. In this example, the ingredients 2 such as gratin and pizza pie in the dish 27 are used.
8 is convenient for heating or baking.

FIG. 9 shows another embodiment of the present invention, in which the work coil 3 and the top plate 2 are arranged in a pair, and a pair of heat insulating plates 16 and metal A heating member (heating member) 6 is provided. In this example, it is convenient to cook or bake a large food material 31 such as a single chicken in the dish 30.

As described above, according to the high-frequency electromagnetic cooker according to the present embodiment, the work coil of the inverter can be protected without turning off the entire apparatus as in the related art, so that the heating is performed for a long time. You can cook well if you need to.

In this embodiment, an antenna coil is provided around the metal heating member to generate an alternating current by interlinking the leakage magnetic flux, and the antenna coil is connected to a DC motor for a cooling device via a rectifier circuit. Preferred configuration for connection or D around the metal heating element and cooling device
According to a preferred configuration of connecting the C motor via a thermocouple, no external power supply is required to operate the cooling device, so that the power cord does not impair the appearance of the electromagnetic cooker, It can also contribute to power saving. In addition, the power cord does not hinder the cleaning, and there is no problem in transporting the power cord to another place.

[0043]

As described above, according to the present invention, a work coil for generating a high frequency, a metal heating member heated by an AC magnetic field generated by the high frequency, a work coil and the metal heating member are provided. A high-frequency electromagnetic induction heater provided with at least a heat insulating means, wherein the metal heating member is composed of a plurality of cylindrical strips having different diameters, so that the cylindrical strip can be efficiently heated by electromagnetic heating. (Heat generation), the heating surface can be effectively used, and even if a liquid such as oil or fat falls from the object to be heated, the probability of falling to the cylindrical strip is low. It is difficult for smoke and fire to occur. Further, even if the metal heating member rapidly expands to a high temperature at which a radiant heat ray is generated, the metal heating member does not undergo thermal deformation and can stably maintain a cylindrical shape. In addition, when it is cylindrical, both the flat surface and the back surface can contribute to heating, and radiant heat rays can be generated most efficiently. As a result,
It is possible to provide a high-frequency electromagnetic cooker excellent in heat uniformity suitable for grilled food cooking. In addition, since electric power is used as an energy source, temperature control is easy, and the cooking environment can be much cleaner than that of charcoal or gas combustion. Furthermore, even when applied to a general heating furnace, the temperature can be raised to a temperature of several hundred degrees within a few minutes, so that the rate of temperature rise is extremely high.

[Brief description of the drawings]

FIG. 1 is a perspective view of a metal heating member (heating member) used in one embodiment of the present invention.

FIG. 2 is a schematic diagram showing one embodiment of a high-frequency electromagnetic cooker according to the present invention.

FIG. 3 is an electric circuit diagram for operating the cooling fan.

FIG. 4 is a schematic view showing another embodiment of the high-frequency electromagnetic cooker according to the present invention.

FIG. 5 is a schematic view showing still another embodiment of the high-frequency electromagnetic cooker according to the present invention.

FIG. 6 shows the shape of a heat insulating plate used in an embodiment of the present invention.

FIG. 7 shows an experimental example of the heating device of FIG.

FIG. 8 shows another embodiment of the present invention, in which a heating unit is installed above.

FIG. 9 is a view showing another embodiment of the present invention, in which a heating unit is installed in a pair at the side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Top plate 3 Work coil 4 Spacer 5 Heat insulating material 6 Metal heating member (heating member) 7, 17 Cooling fan 8 Antenna coil 9 Silicon rectifier 10 Smoothing capacitor 11 DC motor 12 Circuit protection resistor 13 Fan 14 Cooling Hole 15 Hood 16 Insulation material plate 18 Center spacer 18 ′ Hole for passing center spacer 19 Metal heating part 20 Slit hole 21 Central hollow part 22 Suction duct 23 Wire net 24 Fish 25 Liquid falling from fish 26, 29 Heating box 27, 30 Dish 28,31 ingredients

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A47J 27/00

Claims (7)

(57) [Claims] 1. A metal heating member comprising: a work coil for generating a high frequency; a metal heating member heated by an AC magnetic field generated by the high frequency; and a means for thermally insulating the work coil and the metal heating member. From
A high-frequency electromagnetic induction heater that heats and cooks with generated radiant heat rays , wherein the metal heating member includes a plurality of cylindrical strips having different diameters, and an axial direction of the plurality of cylindrical strips is Said
Being located substantially vertically with the food, the insulation means comprises a top plate on the work coil;
A breaker installed on the top plate via a spacer
Heating material plate, the top plate and the insulation material
A high-frequency electromagnetic induction heater characterized by comprising means for blowing air into a gap with a heat sink. 2. The high-frequency electromagnetic induction heater according to claim 1, wherein the plurality of cylindrical strips are fixed at fixed intervals by a fixing device. 3. A plurality of cylindrical strips having a width of 3 to 20 m.
The high-frequency electromagnetic induction heater according to claim 1, wherein the high-frequency electromagnetic induction heater is a nonmagnetic or magnetic stainless steel having a thickness of 0.1 to 1 mm. 4. The heating temperature of the metal heating member is 700 to 1
The high frequency electromagnetic induction heater according to claim 1, wherein the temperature is in the range of 000 ° C. 5. The high frequency electromagnetic induction heater according to claim 1, wherein the heat generated by the metal heating member includes visible light or infrared light. 6. The generated frequency of a work coil is 20 to 3
2. The high frequency electromagnetic induction heater according to claim 1, wherein the frequency is in a range of 0 kHz. 7. The high-frequency electromagnetic induction heater according to claim 1, wherein the high-frequency electromagnetic induction heater is a high-frequency electromagnetic cooker.