JP2014032842A - High-frequency heating cooker - Google Patents

Abstract

An object of the present invention is to reduce heating unevenness of a cooking device equipped with a microwave heating element and improve cooking performance in food cooking.
In a high-frequency cooking device having a microwave heating element 17 mainly composed of a microwave absorbing material that absorbs and radiates irradiated microwaves, the microwave radiation means serves as a microwave radiation means from a circularly polarized radiation opening. When the power feeding method is used, the microwave heating element 17 has at least the first heat generating portion 21 and the microwave to be irradiated from the first heat generating portion 21 against uneven heating due to non-uniformity of the microwave irradiation distribution. The second heat generating part 20 having a large amount of energy is formed, and the film thickness of the first heat generating part 21 of the microwave heat generating body 17 is made larger than the film thickness of the second heat generating part 20, thereby achieving uniform heating properties. The cooking performance of the object to be heated can be improved.
[Selection] Figure 2

Description

  The present invention relates to a heating cooker that performs oven cooking by combining a radiant heater at the top of a heating chamber and a heating element that absorbs microwave energy and generates heat. The present invention relates to a high-frequency cooking device for cooking food uniformly without heating when using power feeding from an opening as microwave irradiation means.

  In recent years, a high-frequency heating device in which a microwave oven and a heater heating device are integrated has been put into practical use.

  In these high-frequency heating devices, a heater is provided in the heating chamber, the air in the heating chamber is heated by radiant heat from the heater, and the temperature in the heating chamber is increased to cook food placed in the heating chamber. .

  In addition, a saucer constructed by attaching a microwave heating element to the bottom surface of the food placing means is disposed in the heating chamber of the high-frequency heating device, and the food is heated mainly by radiant heat from the heater and heat from the microwave heating element. There is a configuration in which grill cooking is performed on both sides with a grilled color or burnt.

  Furthermore, a configuration has also been proposed for performing oven cooking in a limited heating region by heating with a top heater and a microwave heating element.

  With respect to this microwave heating element, conventionally, due to the influence of standing waves generated by the microwaves irradiated inside the heating chamber, the temperature rise of the microwave heating element becomes uneven depending on the site, and uniform heating cooking has been difficult. It was.

  As one of the means for eliminating the non-uniform heating of the microwave heating element due to the standing wave in the heating chamber generated during microwave irradiation into the heating chamber, microwave irradiation is performed for each part of the microwave heating element. There is a configuration in which the thickness of the microwave heating element is changed according to the amount and the content of the microwave absorbing material is adjusted (see, for example, Patent Document 1).

  On the other hand, as a microwave irradiation method to the interior, conventionally, a microwave generated from a magnetron or the like is transmitted through a waveguide and irradiated to the interior by a rotating antenna, or an object to be heated is placed. There was a way for the table itself to rotate. In recent years, with regard to the microwave irradiation method, a circularly polarized wave is radiated from an opening as a microwave radiating portion without using a rotating antenna mechanism or a rotating table mechanism when radiating microwaves into a heating chamber. There is a configuration in which space and cost are reduced (for example, see Patent Document 2).

JP 2011-156185 A U.S. Pat. No. 4,301,347

However, when the microwave heating element placed in the heating chamber is irradiated with microwaves by the circularly polarized wave method, not only nonuniform irradiation of microwave energy by standing waves but also circularly polarized waves are radiated in the heating chamber. Irradiation distribution due to microwaves radiated directly from the opening is generated. As a result, in order to equalize the amount of microwave energy absorbed by the microwave heating element, it is necessary to consider the effect of direct irradiation from the circularly polarized radiation opening in addition to the distribution of the standing wave in the heating chamber .

  Therefore, in order to make the absorption amount of the microwave heating element uniform, the microwave heating element is adjusted with the conventional configuration in which the film thickness, the content of the microwave absorbing material, and the like are adjusted only by the distribution of the standing wave. The temperature of this becomes a non-uniform state, and it becomes difficult to perform uniform heating cooking of the object to be heated, so that there is a problem that good cooking performance cannot be obtained.

  The present invention solves the above-mentioned conventional problems, reduces the uneven heating of the microwave heating element, and, for high-frequency heating cooking utensils, the cooking performance of the microwave heating element in the circularly polarized power feeding system is made uniform. The purpose is to improve.

  In order to solve the above-mentioned problems, the high-frequency cooking device of the present invention is mainly composed of a microwave absorbing material that absorbs microwave energy and generates heat, which is disposed in a cooking device equipped with microwave radiation means. A high-frequency cooking device having a microwave heating element, wherein the microwave heating element includes a first heating part and a second heating part having a microwave irradiation amount larger than that of the first heating part. And the microwave absorption amount of the first heat generating portion is increased to suppress the microwave absorption amount of the second heat generating portion.

  As a result, even when heating unevenness occurs due to the unevenness of the irradiation distribution due to the microwave energy or standing wave emitted from the microwave radiating means, the microwave heat absorption is performed at the first heat generating portion where the amount of microwave irradiation is small. Since the amount of microwave energy absorption is suppressed in the second heat generating part where the amount of microwave irradiation is increased, the amount of absorption is uniform throughout the microwave heating element, and the temperature distribution difference is small. It becomes possible to warm, and uneven heating of the object to be heated can be reduced.

  The high-frequency cooking device of the present invention can reduce uneven heating of the object to be heated, and can ensure stable cooking performance. In addition, a uniform baked color and darkness can be achieved, and the finish of cooking can be improved.

Explanatory drawing which shows the use condition of the high frequency heating cooking appliance in Embodiment 1 of this invention The schematic diagram of the mounting tray which is a high frequency heating cooking appliance in Embodiment 1 of this invention The schematic diagram of the mounting plate which is a high frequency heating cooking appliance in Embodiment 2 of this invention

  1st invention is a high frequency heating cooking appliance which has a microwave heating element which has as a main component a microwave absorption material which absorbs microwave energy and generates heat arranged in a cooking device provided with microwave radiation means The microwave heating element includes a first heat generating portion and a second heat generating portion having a microwave irradiation amount larger than that of the first heat generating portion. Non-uniform heating of the microwave heating element caused by non-uniformity due to the standing wave of the microwave in the heating chamber is configured to increase the amount of wave absorption and suppress the amount of microwave absorption in the second heat generating portion. This ensures a stable cooking performance of the object to be heated, a uniform baked color, and the finish of cooking by scorching.

In particular, the second aspect of the invention has a configuration in which the microwave radiating means of the first aspect of the invention radiates microwaves from the circularly polarized radiation opening that generates circularly polarized waves into the heating cooker. The microwave heating element can irradiate the microwave heating element with high efficiency by the straightness of microwave radiation unique to the wave.

  In the third invention, in particular, the second heat generating portion of the first or second invention passes through the center of the microwave radiating section, and the oscillation frequency of the microwave generating means is centered on the normal to the microwave radiating section. This is a part of the microwave heating element in a region having a radius of at least 1/4 to 1/2 of the microwave wavelength in the waveguide means in the region, and this part is from the circularly polarized radiation opening. Because the microwave of this is a part where the microwave energy irradiation is particularly strong due to the straightness characteristic of circular polarization, the microwave absorption amount can be suppressed in the region where the direct microwave irradiation amount is large. Uneven heating of the wave heating element can be reduced, and uniform heating cooking of the object to be heated can be performed.

  In the fourth invention, in particular, the microwave heating element of the first to third inventions is configured such that the film thickness of the first heat generating portion is larger than the film thickness of the second heat generating portion. Suppresses the amount of absorption at the site with a large amount of microwave irradiation, and increases the amount of microwave absorption at the region with a small amount of microwave irradiation, making the temperature distribution uniform and enabling uniform cooking. . Moreover, it is easy to form a heating element in the manufacturing process, and a cooking utensil excellent in productivity can be realized.

  In the fifth invention, in particular, the content of the microwave absorbing material contained in the first heat generating portion of the first to fourth inventions is greater than the content of the microwave absorbing material contained in the second heat generating portion. It is possible to control the amount of microwave absorption by changing the content of the microwave absorbing material in each part. By reducing the unevenness of heating of the microwave heating element, the object to be heated can be made uniform. Heat cooking is possible.

  In the sixth invention, in particular, the microwave absorbing material of the first to fifth inventions is made of ferrite having a Curie temperature of 250 ° C. to 300 ° C., so that the magnetic characteristics governing the absorption performance of microwave energy are obtained. Since the temperature can be expressed from 250 ° C. to near 300 ° C., the temperature reached by the grill pan can be increased, the cooking performance of the grill pan can be improved, and when the ferrite is close to the Curie temperature, the microwave Since energy is not absorbed, excessive heating of the microwave heating element and the mounting plate is prevented, and excellent durability and safety can be realized.

  In the seventh invention, in particular, the microwave heating element according to the first to sixth inventions is composed of at least a microwave absorbing material and a binder for holding the microwave heating element, so that the microwave heating element and the microwave heating element are mounted. The adhesiveness of the dish can be improved, peeling and cracking of the microwave heating element can be prevented, and heat generation performance can be maintained for a long time. Therefore, always stable cooking can be realized. Moreover, since washing after cooking can be easily performed, convenience is high.

  In the eighth aspect of the invention, in particular, the moldability of the microwave heating element is improved and excellent heat resistance is achieved by using silicone rubber as the binder for holding the microwave heating element of the first to seventh inventions. Therefore, it is possible to realize a microwave heating element with high durability and reliability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The shape of the mounting tray according to the embodiment of the present invention shows a form of a microwave heating element formed on the back side of the mounting surface of the flat plate, with the mounting surface on which the food is mounted being a flat plate. . Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is an explanatory view showing a use state of the high-frequency heating cooker according to the first embodiment of the present invention, and is an explanatory view of a positional relationship among a microwave heating element, a heating cooker, and a circularly polarized radiation opening. .

  In FIG. 1, a heating cooker 12 includes a heating chamber 13 for storing an object to be heated, a microwave generating means 14 for generating microwaves, a waveguide means 15 for transmitting microwaves to the heating chamber 13, and transmission The microwave is radiated into the heating chamber 13 as a circularly polarized wave, the circularly polarized radiation opening 16, the mounting plate 30 disposed in the heating chamber 13, and the mounting plate 30. It is mainly composed of a microwave heating element 17 that generates heat by being irradiated with waves. The circularly polarized radiation opening 16 is schematically represented by the shape of the opening and the number of openings.

  In FIG. 1, with respect to the microwave heating element 17, the microwave wavelength in the oscillation frequency region of the microwave generating means is at least from the normal line 19 passing through the center of the circularly polarized radiation opening to the circularly polarized radiation opening. The positional relationship of the 2nd heat_generation | fever site | part 20 to the range which the distance of 1/4 to 1/2 left | separated, and the 1st heat_generation | fever part 21 of the area | region of the circumference | surroundings is represented.

  FIG. 2 is a schematic diagram of a mounting plate that is a high-frequency cooking device according to the first embodiment of the present invention. 2A is a plan view of the back surface, and FIG. 2B is a cross-sectional view of the A-A ′ plane of FIG. FIG. 2 also schematically represents the position of the circularly polarized radiation opening when viewed from above.

  In FIG. 2, a mounting dish 30 that is a high-frequency cooking device includes a mounting surface 31 on which food is placed and a microwave heating element 17 formed on the back side of the mounting surface 31. Further, the microwave heating element 17 includes a first heat generating portion 21 located in a peripheral region of the mounting surface 31 and a circular shape of the mounting surface 31 having a larger microwave energy irradiation amount than the first heat generating portion 21. The second heat generating portion from the normal line 19 to the circularly polarized radiation opening portion passing through the center of the polarized radiation opening portion to at least a range of 1/4 to 1/2 distance of the microwave wavelength in the magnetron oscillation frequency region The thickness t1 of the first heat generating portion is larger than the thickness t2 of the second heat generating portion.

  When microwave energy is irradiated into the heating chamber 13, a standing wave is generated in the heating chamber 13. Therefore, the irradiation of microwave energy is in a non-uniform state. Furthermore, the direct radiation from the circularly polarized radiation opening 16 makes the non-uniform distribution of microwave energy noticeable. When the mounting plate 30 having the microwave heating element 17 formed so that the absorption of the microwave energy is uniform in the heating chamber 13, the microwave heating element 17 is caused by the non-uniformity of the microwave energy in the cabinet. The amount of microwave energy applied to the light becomes non-uniform, that is, in the portion where the amount of microwave irradiation energy is small, the amount of microwave energy absorbed by the microwave heating element 17 is small, and in the portion where the amount of microwave irradiation energy is large. The amount of microwave energy absorbed by the microwave heating element 17 increases. As a result, the temperature rise of the microwave heating element 17 becomes non-uniform, and problems such as non-uniform baking color with respect to food in cooking and a decrease in cooking performance occur.

  In the microwave heating element 17 of the present invention, since the thickness of the microwave heating element 17 in the first heating part 21 with a small amount of irradiated microwave energy is increased, the microwave energy absorption efficiency is high. Therefore, even if the microwave irradiation energy amount is small, the microwave absorption amount can be increased.

  On the other hand, since the film thickness of the second heat generating portion 20 with a large amount of irradiated microwave energy is thinner than that of the first heat generating portion 21, the absorption efficiency of the microwave energy is lowered, and the microwave absorption amount is reduced. Can be suppressed.

As a result, the temperature distribution of the entire microwave heating element 17 approaches uniformly, and the uneven heating temperature of the mounting surface 31 of the mounting tray 30 is reduced, so that a stable finished state of the food is obtained and the uniform baking color is obtained. , Can burn and improve cooking performance.

  In addition, the film thickness in the 2nd heat_generation | fever part 20 may be zero.

  The microwave heating element 17 of the present invention is composed of a composition of at least a microwave absorbing material and a binder for holding the microwave absorbing material. More specifically, as the microwave absorbing material, ferrite and binder are used. Silicone rubber is used.

  By using silicone rubber as a binder, the adhesiveness between the microwave heating element 17 and the mounting tray 30 can be improved, so that peeling and cracking of the microwave heating element 17 are prevented, and heat generation performance is maintained for a long time. In addition to being able to realize stable cooking performance at all times, silicone rubber has excellent heat resistance and chemical resistance, so that the microwave heating element 17 having high durability and reliability can be realized.

  In addition, the microwave heating element 17 can easily form a composition of ferrite and silicone rubber on the mounting tray 30 by hot pressing, and the first heating portion 21 and the second heating portion 21 of the microwave heating element 17. Since the heat generating portion 20 of FIG. 1 has only a different film thickness, there is no need to change the type of ferrite material, the blending ratio with the silicone rubber, and the like. By designing a hot press mold so that a predetermined film thickness can be obtained for the heat generating portion 20, the microwave heating element 17 can be formed by a single press, and productivity can be improved.

  Furthermore, since the microwave heating element 17 has high heat resistance and can reduce uneven heating, the temperature of the entire mounting tray 30 can be raised uniformly, and cooking performance can be improved.

  The microwave absorbing material used for the microwave heating element 17 of the present invention is preferably ferrite having a Curie temperature of 250 ° C to 300 ° C. By using this ferrite, it is possible to develop the magnetic properties that govern the absorption performance of microwave energy from the temperature of 250 ° C. to the vicinity of 300 ° C., so that the temperature reached by the mounting tray 30 can be further increased, Cooking performance can be improved. Furthermore, when the ferrite is heated to a temperature close to the Curie temperature, the magnetic characteristics governing the absorption of the microwave energy are lowered, and the microwave energy absorption efficiency is lowered, so that the heating of the microwave heating element 17 is stopped, Overheating of the mounting tray 30 is prevented, and excellent durability and safety can be realized.

  In addition, the film thickness of each of the first heat generating portion 21 and the second heat generating portion 20 of the microwave heat generating body 17 is as follows: input power of microwave energy, mounting plate area, cooking heating temperature, circularly polarized radiation opening It is appropriately selected depending on the position and shape of 16.

  In addition, the first heat generating portion 21 and the second heat generating portion 20 such as the shape of the microwave heat generating body 17 shown in FIG. The present invention is also applicable to a configuration in which the wave heating element 17 as a whole is inclined in film thickness.

  The circularly polarized radiation opening 16 has a configuration in which two slits intersecting at right angles intersect with each other, and a shape inclined by 45 degrees with respect to the microwave transmission direction is arranged. It may be a type radiation opening, a T type radiation opening, or an L type radiation opening.

  In addition, the position of the circularly polarized radiation opening 16 is schematically represented by a plurality of openings as shown in FIG. 2 at this time. However, the position may be single or the arrangement position may be changed. good.

  As described above, in the present embodiment, at least the microwave heating element 17 includes the first heat generating portion 21 and the second heat generating portion 20 having a microwave irradiation energy amount larger than that of the first heat generating portion 21. The thickness of the first heat generating portion 21 is made thicker than that of the second heat generating portion 20, so that the amount of microwave energy absorbed in each heat generating portion can be equalized. And the heating unevenness of the mounting surface 31 of the mounting tray 30 is reduced, and cooking performance can be improved.

(Embodiment 2)
FIG. 3 is a schematic view of a mounting plate that is a high-frequency cooking device according to the second embodiment of the present invention. More specifically, FIG. 3A is a plan view when the mounting plate 30 is viewed from the back surface, and FIG. 3B is a cross-sectional view taken along the line BB ′ of FIG.

  The difference from the first embodiment is not the film thickness of the first heat generating portion and the second heat generating portion of the microwave heat generating element, but the content of the microwave absorbing material included in the composition constituting the microwave heat generating element. The material used for the mounting tray and the microwave heating element is the same as that of the first embodiment.

  In FIG. 3, the mounting tray 30 includes a mounting surface 31 on which food is placed and a microwave heating element 17 formed on the back side of the mounting surface 31. Further, the microwave heating element 17 is located in a region around the mounting surface 31 and a region where a distance of 1/4 to 1/2 of the microwave wavelength in the magnetron oscillation frequency region is separated from the circularly polarized radiation opening 16. The content of the microwave absorbing material in the first heat generating part 21 is set to be larger than the content of the microwave absorbing material in the second heat generating part 20.

  The placing plate 30 having the above-described configuration is installed in the heating chamber 13 of the microwave heating device (not shown), and is heated by absorbing microwave energy. Can be cooked.

  In the microwave heating element 17 of the present invention, the first heating portion 21 having a small microwave irradiation energy amount increases the content of the microwave absorbing material in the microwave heating element 17, so Even if the irradiation energy amount is small, the microwave absorption amount can be increased.

  Further, since the second heat generating portion 20 having a large amount of microwave irradiation energy has a content of the microwave absorbing material smaller than that of the first heat generating portion 21, the absorption efficiency of the microwave energy is lowered, and the Wave energy absorption is suppressed.

  As a result, the temperature difference of the entire microwave heating element 17 can be reduced, and uneven heating of the mounting surface 31 of the mounting tray 30 is suppressed, so that a stable finish of food is obtained and uniform heating is achieved. A uniform baked color and scorch can be created by cooking, and the cooking performance can be improved.

  Since the present invention requires at least two different types of microwave absorbing materials for forming the microwave heating element 17, the production of this composition and the hot pressing process are more complicated than in the first embodiment, but the same An effect can be obtained.

As described above, in the present embodiment, at least the microwave heating element 17 includes the first heating part 21 and the second heating part 20 having a microwave irradiation energy amount larger than that of the first heating part 21. By making the content of the microwave absorbing material in the first heat generating portion 21 larger than that in the second heat generating portion 20, the amount of microwave energy absorbed in each heat generating portion can be made uniform. Thus, uneven heating of the microwave heating element 17 and the mounting tray 30 is reduced, and cooking performance can be improved.

  In the first and second embodiments, the wavelength of the microwave in the magnetron oscillation frequency region centering on the normal to the opening passing through the center of the circularly polarized radiation opening at the second heating portion of the microwave heating element. The microwave heating element part in the range of ¼ to ½ of the above, and the other part as the first heating part, the presence of a standing wave of microwave energy in the heating chamber, In the circularly polarized wave feeding method, depending on the shape of the heating chamber, there is a part where the microwave radiation from the opening is increased near the end of the waveguide, and it can be clearly divided into two heat generation parts. is not. Therefore, heating unevenness can be achieved by forming a heat generation site with a structure in which the film thickness and microwave absorbing material are changed to match the distribution of microwave energy depending on the standing wave generated and the distance from the center of the opening. Can be improved.

  In the first embodiment, the thickness of the microwave heating element is described, and in the second embodiment, the change of the microwave absorbing material is described. However, the combination of the first and second embodiments is also applicable.

  In Embodiments 1 and 2, the effect of the configuration in which the heat generating part is divided into two regions has been described. However, in order to further suppress heating unevenness, it may be divided into three or more regions.

  As described above in detail, the high-frequency cooking device according to the present invention can be applied to a microwave heating device such as a microwave oven.

DESCRIPTION OF SYMBOLS 12 Heating cooker 13 Heating chamber 14 Microwave generation means 15 Waveguide means 16 Circularly polarized radiation opening part 17 Microwave heating element 19 Normal 20 Second heat generation part 21 First heat generation part 30 Placement plate 31 Placement Surface t1 thickness of the first heat generating portion t2 thickness of the second heat generating portion

Claims (8)

A high-frequency cooking device having a microwave heating element mainly composed of a microwave absorbing material that absorbs microwave energy and generates heat by being placed in a cooking device equipped with microwave radiation means,
The microwave heating element has a first heating part and a second heating part having a microwave irradiation amount larger than that of the first heating part, and the microwave absorption amount of the first heating part is increased. A high-frequency cooking device that is configured to increase and suppress the amount of microwave absorption of the second heat generating portion. The high-frequency cooking device according to claim 1, wherein the microwave radiation means is configured to radiate microwaves from a circularly polarized radiation opening for generating circularly polarized light into the cooking device. The second heat generating portion passes through the center of the microwave radiating portion and has a normal to the microwave radiating portion as a central axis, and at least 1/4 of the microwave wavelength in the waveguide means in the oscillation frequency region of the microwave generating means. The microwave heating cooking appliance according to claim 1 or 2, which is a part of a microwave heating element in a region having a radius of ½ from the length. The high frequency heating cooking appliance according to any one of claims 1 to 3, wherein the microwave heating element is configured such that the film thickness of the first heat generating portion is thicker than the film thickness of the second heat generating portion. The high frequency heating according to any one of claims 1 to 4, wherein the content of the microwave absorbing material contained in the first heat generating part is greater than the content of the microwave absorbing material contained in the second heat generating part. kitchenware. The high-frequency cooking device according to any one of claims 1 to 5, wherein the microwave absorbing material is ferrite having a Curie temperature of 250 ° C to 300 ° C. The high-frequency cooking device according to any one of claims 1 to 6, wherein the microwave heating element comprises at least a microwave absorbing material and a binder for holding the microwave heating element. The high-frequency cooking device according to any one of claims 1 to 7, wherein the binder for holding the microwave heating element is silicone rubber.