JP2014032788A - Microwave heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microwave heating device capable of efficiently and uniformly heating a heated object by a simple structure not using a rolling mechanism and the like for a table, an antenna, and a phase shifter, and to prevent attaching means for a mounting part for radiation heating from impeding uniform heating property even when a configuration is shared with radiation heating cooking.SOLUTION: In a state that a microwave transmitted in a waveguide 106 is a progressive wave 401 with a few standing waves, by emitting the progressive wave whose a radiant quantity is changed via openings distributed at a plurality of positions, a heated object 102 can be heated uniformly without using a rolling mechanism. Further, by configuring so that an attaching direction 112 of a mounting part for radiation heating is substantially the same as a microwave transmission direction 113, such a configuration that attaching means 111 does not impede uniformity at microwave heating can be achieved.

Description

  The present invention relates to a microwave heating apparatus such as a microwave oven, and more particularly to a microwave heating apparatus characterized by the structure of a microwave radiation portion.

  A typical microwave heating apparatus that heats an object to be heated with a microwave is a microwave oven. In the microwave oven, the microwave generated in the microwave supply means is radiated into the metal heating chamber, and the object to be heated in the heating chamber is heated by the radiated microwave.

  A magnetron is used as a microwave supply means in a conventional microwave oven. Microwaves generated by the magnetron are radiated into the heating chamber through the waveguide. If the electromagnetic field distribution of the microwave in the heating chamber is not uniform, the object to be heated cannot be heated by microwaves uniformly.

  As a means for uniformly heating the object to be heated, a structure for rotating the object to be heated by rotating a table on which the object to be heated is rotated, a structure for rotating an antenna for radiating microwaves while fixing the object to be heated, or A microwave heating apparatus having a structure in which the phase of the microwave generated from the microwave supply means is changed by a phase shifter has been common.

  For example, in a conventional microwave heating apparatus, a rotating antenna, an antenna shaft, and the like are arranged inside a waveguide. By driving a magnetron while rotating the rotating antenna by an antenna motor, the microwave distribution in the heating chamber is increased. Non-uniformity is reduced.

  Further, as described in Patent Document 1, a rotatable antenna is provided on the upper part of the magnetron, and the antenna is rotated by the wind of the blower fan by applying cooling air from the blower fan to the blades of the rotary antenna. There has been proposed a microwave heating apparatus that changes the microwave distribution in the heating chamber.

  On the other hand, as described in Patent Document 2 which reduces the uneven heating of the object to be heated by microwave heating and reduces the cost and saves the space of the power feeding unit, it simply radiates circularly polarized waves into the heating chamber. A microwave heating apparatus having a single microwave radiating portion has been proposed.

JP 62-064093 A U.S. Pat. No. 4,301,347

  However, in the microwave heating apparatus such as the microwave oven having the above-described conventional configuration, it is required to efficiently heat an object to be heated with a simple structure as much as possible, and has been proposed so far. There were various problems with the structure.

In addition, microwave heating devices, particularly microwave ovens, have been developed for high-power technology, and a rated high-frequency output of 1000 W has been commercialized in Japan. Microwave ovens are notable for heating food by heat conduction, but the convenience of directly heating food using dielectric heating is a major feature of the product. The problem of non-uniform heating will become more apparent.

  The following two points can be cited as structural problems of the conventional microwave heating apparatus.

  The first point requires a mechanism for rotating the table or antenna in order to reduce non-uniform heating. Therefore, it is necessary to secure a rotation space and an installation space such as a motor for rotating the table or antenna. That was hindering the miniaturization of the range.

  The second point is that in order to stably rotate the table or antenna, it is necessary to provide the rotating antenna above or below the heating chamber, and the structure is limited.

  Installing a table or a phaser rotation mechanism in the microwave irradiation chamber of the microwave heating apparatus lowers the reliability. Therefore, there is a demand for a microwave heating apparatus that does not require these mechanisms.

  Further, circularly polarized light is radiated into the heating chamber as described in Patent Document 2 which reduces the uneven heating of the object to be heated by microwave heating and reduces the cost and saves the space of the power feeding unit. The microwave heating apparatus having a single microwave radiating portion has an advantage that it does not have a rotating mechanism, but the problem is that sufficient uniform heating by microwave heating has not been realized.

  In addition, when the heating chamber is configured to be used not only for microwave heating but also for radiant heating cooking, a mounting means for the mounting portion for radiant heating cooking is required. There exists a subject that it is necessary to take the structure which does not prevent the uniform heating property.

  The present invention solves the above-mentioned problem, and can heat the object to be heated uniformly without using a rotating mechanism, and the means for mounting the mounting portion for radiant heating cooking hinders uniform heating. An object of the present invention is to provide a microwave heating apparatus having no configuration.

  In order to solve the above-described conventional problems, the microwave is guided to the heating chamber by the heating chamber input portion at the end portion of the waveguide, and the microwave transmitted through the waveguide is a traveling wave with few standing waves. By radiating microwaves into the heating chamber by heating the object to be heated by the microwave radiating part provided in the waveguide, the microwaves with varying radiation can be radiated from the openings dispersed in multiple locations. Therefore, it is possible to uniformly heat the object to be heated without using a rotating mechanism, and when the heating chamber is used for radiant heating cooking, the radiation by the mounting means of the radiant heating mounting portion is used. By configuring the mounting portion for heating to be mounted in substantially the same direction as the microwave transmission direction, it is possible to provide a microwave heating device in which the mounting means does not hinder the uniformity during microwave heating.

  In addition, by using a microwave heating device in which a plurality of microwave radiation portions are arranged symmetrically with respect to the center of the heating chamber, the amount of radiation to the object to be heated in the heating chamber is symmetric and uniform microwave radiation is performed. be able to.

  Moreover, the amount of microwaves used for heating the object to be heated is set so that the total amount of microwaves input from the heating chamber input unit to the heating chamber is 10% or less of the total amount of microwaves radiated from the microwave radiating unit. Can be ensured, and the traveling wave can be dominant.

  In addition, the heating chamber input section is composed of a termination section and a termination radiation section, and the distance between the termination section and the center of gravity of the termination radiation section is an odd multiple of approximately 1/4 of the in-tube wavelength of the waveguide. Thus, a standing wave based on the wavelength inside the tube is arranged at the center of gravity of the terminal radiating part to make it easy to emit the microwave from the terminal radiating part, and the microwave transmitted through the waveguide can be a traveling wave.

  In addition, the heating chamber input section is composed of a termination section and a termination radiation section, and the distance between the termination section and the center of gravity of the termination radiation section is an odd multiple of approximately 1/4 of the oscillation wavelength of the microwave supply means. As a result, the microwave absorbed by the object to be heated is small, and the once radiated microwave returns from the heating chamber to the waveguide through the microwave radiating section at the wavelength of the microwave supply means. When placing emphasis on the light load heating performance shown, placing the antinode of the standing wave generated on the basis of the oscillation wavelength of the microwave supply means at the center of gravity of the terminal radiating unit makes it easy to extract the microwave from the terminal radiating unit. The microwave that transmits can be a traveling wave.

  In addition, since the terminal radiating portion also functions as the microwave radiating portion, the heating chamber input portion can be configured in a compact manner.

  Moreover, the uniform heating range can be further widened by forming the microwave radiating part to emit circularly polarized waves.

  According to the present invention, the microwave transmitted through the waveguide is made to be a traveling wave with less standing wave by guiding the microwave into the heating chamber by the heating chamber input section at the waveguide end portion. Thus, the object to be heated can be heated by radiating the microwave into the heating chamber by the microwave radiating portion provided in the waveguide. According to this configuration, since the traveling wave whose amplitude changes passes through the microwave radiating unit, the microwave whose radiation amount changes is radiated from the openings dispersed in a plurality of locations, and the rotation mechanism is It is possible to uniformly heat the object to be heated without using it, and when the heating chamber is used for radiant heating cooking, the mounting direction of the radiant heating mounting portion by the mounting means of the radiant heating mounting portion Is configured so as to be substantially in the same direction as the microwave transmission direction, it is possible to provide a microwave heating apparatus in which the attachment means does not hinder the uniformity during microwave heating.

Sectional drawing of the microwave heating apparatus in Embodiment 1 of this invention The perspective view of the microwave heating apparatus in Embodiment 1 of this invention The perspective view of the microwave heating apparatus in Embodiment 1 of this invention FIG. 3 is an explanatory diagram of the relationship between the microwave radiating unit and the traveling wave of the microwave heating apparatus according to Embodiment 1 of the present invention. Relation explanatory drawing explaining the microwave radiation | emission part arrangement | positioning of the microwave heating apparatus in Embodiment 1 of this invention Relationship explanatory drawing explaining the microwave radiation in Embodiment 1 of this invention Explanatory drawing of the relationship between microwave radiation and attachment means in Embodiment 1 of the present invention Explanatory drawing of the relationship between microwave radiation and attachment means in Embodiment 1 of the present invention Explanatory drawing of the relationship between the microwave radiation | emission part and traveling wave of the microwave heating device in Embodiment 2 of this invention Explanatory drawing of the relationship between the microwave radiation | emission part and traveling wave of the microwave heating device in Embodiment 2 of this invention

1st invention is the heating chamber which puts a to-be-heated material, the mounting part which mounts the said to-be-heated material, the microwave supply means for supplying a microwave to the said heating chamber, The said microwave supply means A waveguide for transmitting the microwave supplied from the heating chamber to the heating chamber, a heating chamber input for guiding the microwave passing through the waveguide at the end of the waveguide to the heating chamber, and A plurality of microwave radiating sections arranged in a microwave transmission direction between the microwave supply means and the heating chamber input section to radiate microwaves passing through the waveguide to the object to be heated in the heating chamber; Heating means for radiant heating cooking, a detachable radiant heating mounting part that is attached to the inside of the heating chamber in order to place an object to be heated during radiant heating cooking by the heating means, and the radiant heating mounting part Mounting means for attaching And a microwave heating device in which the mounting direction of the radiation heating mounting portion and the microwave transmission direction are substantially the same in which the mounting means mounts the radiation heating mounting portion. In the state where the microwave is guided into the heating chamber by the heating chamber input section, and the microwave transmitted through the waveguide is a traveling wave with less standing waves, the microwave is transmitted by the microwave radiation section provided in the waveguide. By heating the object to be heated by radiating it into the heating chamber, it is possible to radiate microwaves with varying radiation amounts from openings dispersed in multiple locations, so the object to be heated can be made uniform without using a rotating mechanism. When the heating chamber is used for radiant heating cooking, the mounting means for the radiant heating mounting portion is configured to be substantially in the same direction as the microwave transmission direction. Doing, it is possible to provide a microwave heating apparatus which does not inhibit the uniformity during microwave heating attachment means.

  In particular, the second invention is a microwave heating device in which a plurality of the microwave radiating portions of the first invention are arranged symmetrically with respect to the center of the heating chamber. The amount of radiation is symmetric and microwave radiation can be performed uniformly.

  In the third invention, in particular, the total amount of microwaves input to the heating chamber from the heating chamber input unit of the first or second invention is 1 of the total amount of microwaves radiated from the microwave radiation unit. By using a microwave heating apparatus that is not more than 30%, it is possible to secure a large amount of microwaves used for heating an object to be heated and to make a traveling wave dominant.

  In a fourth aspect of the invention, in particular, the heating chamber input section according to any one of the first to third aspects of the present invention is configured by a termination portion and a termination radiation portion, and the distance between the termination portion and the center of gravity of the termination radiation portion is: By using a microwave heating apparatus that is an odd multiple of approximately ¼ of the in-tube wavelength of the waveguide, an antinode of a standing wave based on the in-tube wavelength is placed at the center of gravity of the end radiating portion so that the micro wave from the end radiating portion can be reduced. Waves can be easily generated and the traveling wave component of the microwave transmitted through the waveguide can be further enhanced.

  In the fifth aspect of the invention, in particular, the heating chamber input section of any one of the first to third aspects of the present invention is configured by a termination portion and a termination radiation portion, and a distance between the termination portion and the center of gravity of the termination radiation portion is By using a microwave heating device that is an odd multiple of approximately 1/4 of the oscillation wavelength of the microwave supply means, there is little microwave absorbed by the object to be heated, and the microwave that has been radiated once is the microwave radiation section When the light load heating performance showing the characteristic of returning from the heating chamber into the waveguide at the wavelength of the micro supply means is emphasized, the constant radiation generated on the basis of the oscillation wavelength of the microwave supply means at the center of the terminal radiation section By arranging the antinodes of the standing waves, the microwaves can be easily emitted from the terminal radiation portion, and the traveling wave component of the microwaves transmitted through the waveguide can be further strengthened.

  In the sixth aspect of the invention, in particular, the terminal radiating section of the fourth or fifth aspect is a microwave heating means that also functions as the microwave radiating section, so that the bottom surface of the heating chamber is uniformly heated to the object to be heated. The heating chamber input section can be configured compactly.

  According to a seventh aspect of the present invention, in particular, the microwave heating unit according to any one of the first to sixth aspects is a microwave heating device having a shape that radiates circularly polarized waves, thereby providing a uniform heating range. Can be wider.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment of a microwave heating apparatus according to the invention will be described with reference to the accompanying drawings. In the microwave heating apparatus of the following embodiment, a microwave oven will be described. However, the microwave oven is an example, and the microwave heating apparatus of the present invention is not limited to the microwave oven, and uses dielectric heating. And a microwave heating device such as a garbage processing machine or a semiconductor manufacturing device. Further, the present invention is not limited to the specific configurations of the following embodiments, and configurations based on similar technical ideas are included in the present invention.

(Embodiment 1)
FIG. 1 is a cross-sectional view of the microwave heating apparatus according to the first embodiment of the present invention. In FIG. 1, a housing 101, an object to be heated 102, a heating chamber 103, a placement portion 104, a microwave supply means 105, a waveguide 106, a heating chamber input portion 107, a microwave radiation portion 108, a heating means 109, radiation. A microwave heating apparatus is constituted by the heating mounting portion 110, the attachment means 111, and the door 114.

  The mounting portion 104 is a glass plate, the microwave supplying means 105 is a magnetron, the waveguide 106 is a rectangular waveguide, the microwave radiating portion 108 is an opening provided in the waveguide 106, and a heating means. This configuration can be easily realized by using 109 as a heater, a metal dish as the radiant heating mounting portion 110, and a rail-like convex portion provided on the side wall of the heating chamber 103 as the attachment means 111.

  The heating chamber input unit 107 includes a termination unit 115 and a termination radiation unit 116, and the interval between the termination unit 115 and the center of gravity of the termination radiation unit 116 is an in-tube wavelength λg of the microwave transmitted through the waveguide 106. The heating chamber 103 and the waveguide 106 are arranged on the surface in contact with each other so that the distance is an odd multiple of approximately 1/4 of the distance.

  In addition, in FIG. 1, the mounting direction for attaching and removing the mounting portion 110 for radiation heating is defined as a mounting portion 112 for mounting the mounting portion for radiation heating. In FIG. 1, the microwave transmission direction in the waveguide 106 on the surface (the lower surface in FIG. 1) of the heating chamber 103 where the microwave radiating unit 108 is disposed is defined as a microwave transmission direction 113. In the present embodiment, the radiant heating mounting portion mounting direction 112 and the microwave transmission direction 113 are configured to be substantially the same direction.

  2 and 3 are perspective views of the microwave heating apparatus according to the first embodiment of the present invention. FIG. 2 shows a state in which the radiation heating mounting part 110 is removed, and FIG. 3 shows a state in which the radiation heating mounting part 110 is attached in the radiation heating mounting part mounting direction 112 using the attachment means 111. .

  4A and 4B are explanatory diagrams of the relationship between the microwave radiating unit and the traveling wave of the microwave heating apparatus according to the first embodiment of the present invention. FIG. 4A is a side view of the waveguide 106, and FIG. It is the schematic of the microwave radiation | emission part of a waveguide upper surface. Here, a configuration is described in which the microwave radiating portion 108 is an opening provided in the upper portion of the waveguide 106 and microwaves existing in the waveguide 106 are radiated to the heating chamber 103.

The operation and action of the microwave heating apparatus configured as described above will be described in the following order.
(1) The action of converting the microwave into a traveling wave according to the configuration of the heating chamber input unit 107.
(2) Action by traveling wave and overall operation of microwave heating apparatus.
(3) The effect | action by the structure which makes the mounting part mounting direction 112 for radiation heating and the microwave transmission direction 113 into the substantially same direction.

  First, (1) the action of converting the microwave into a traveling wave according to the configuration of the heating chamber input unit 107 will be described.

  The microwave that is supplied from the microwave supply means 105 and travels in the waveguide 106 generates a standing wave based on the wavelength λg in the tube as shown in FIG. Form. Here, as shown in FIG. 4B, the center of gravity of the terminal radiating section 116 is positioned at the antinode of the standing wave on the basis of the guide wavelength λg (an odd multiple of (approximately 1/4 of the guide wavelength of the waveguide 106)). As a result, the microwave input opening to the heating chamber 103 is installed in the maximum standing wave amplitude portion, and microwave radiation to the heating chamber 103 is performed from the formed standing wave based on the in-tube wavelength λg. Can be made easier.

  As a result, the traveling wave can be dominant in the microwave transmitted through the waveguide 106. In this state, the microwave radiating unit 108 has a large opening, and the microwave input from the heating chamber input unit 107 is set to be 10% or less of the total microwave radiated from the microwave radiating unit 108. By doing so, it is possible to secure a large amount of microwaves used for heating the article to be heated 102 and to make the traveling wave 401 dominant.

  Further, by arranging the terminal radiating unit 116 so as to function as the microwave radiating unit 108 for heating the article to be heated 102 like the terminal radiating unit 501 shown in FIG. The heating chamber input section can be configured in a compact manner without much reduction.

  As described above, the distance between the terminal portion 115 constituting the heating chamber input portion 107 and the center of gravity of the terminal radiating portion 116 is an odd multiple of approximately 1/4 of the in-tube wavelength of the waveguide 106. The microwave can be easily emitted from the terminal radiating section 116, and the traveling wave component of the microwave transmitted through the waveguide 106 can be further strengthened.

  Further, by arranging the terminal radiation portion so as to also function as the microwave radiation portion 108 for heating the object to be heated 102, the bottom surface of the heating chamber 103 is heated without significantly reducing the uniform heating performance. The heating chamber input section can be configured compactly by effectively utilizing the uniform heating of the object 102.

  Next, (2) the action by the traveling wave and the overall operation of the microwave heating apparatus will be described.

  When performing microwave heating with a microwave heating device, first, when the object to be heated 102 is placed on the mounting portion 104 in the heating chamber 103 by a user and a heating start instruction is given, the microwave heating device is A microwave is supplied into the waveguide 106 from the magnetron which is the microwave supply means 105. As described above, the microwave transmitted through the waveguide 106 becomes a traveling wave.

  When the traveling wave 401 is transmitted through the waveguide 106, the traveling wave 401 travels while changing the amplitude in the microwave radiating unit 108 as indicated by a dotted line in FIG.

  Therefore, the microwave that is radiated from the microwave radiating unit 108 to the heating chamber 103 and heats the object to be heated 102 is dispersed in a plurality of openings while changing the amount of radiation according to the amplitude change of the traveling wave 401 that is the radiation source. Will be emitted.

As described above, the microwave is applied to the heating chamber 1 by the heating chamber input unit 107 at the end portion of the waveguide.
In the state where the microwave transmitted through the waveguide 106 is changed to a traveling wave 401 having a small number of standing waves, the microwave radiation unit 108 provided in the waveguide 106 converts the microwave into the microwave 106. Can be radiated into the heating chamber 103 to heat the article to be heated 102.

  According to this configuration, since the traveling wave 401 whose amplitude changes passes through the microwave radiating unit 108, the microwave whose radiation amount changes is radiated from the openings dispersed in a plurality of locations, and is rotated. The object to be heated 102 can be uniformly heated by microwaves without using a mechanism.

  When the heating chamber 103 of the microwave heating apparatus is used for radiant heating cooking, the radiant heating mounting part 110 is first installed by the user in the radiant heating mounting part mounting direction 112 by the mounting means 111. Next, when the object to be heated 102 is placed on the radiant heating mounting unit 110 and a heating instruction is given, the heating means 109 performs radiant heating. At this time, the mounting section 112 for mounting the radiation heating and the microwave transmission direction 113 are configured to be substantially the same direction.

  Next, the effect | action by the structure which makes (3) the mounting part mounting direction 112 for radiant heating and the microwave transmission direction 113 substantially the same direction is demonstrated. FIG. 6 shows a state in which microwaves are radiated from the waveguide 106 by the microwave radiating unit 108. As shown in FIG. 6, the microwave radiated from the microwave radiating unit 108 is radiated from the traveling wave component 601 that is in the same direction as the microwave transmission direction 113 traveling through the waveguide 106 and the microwave radiating unit 108. As a combined wave of the radiation component 602, the light is emitted with a microwave radiation direction 603. The emitted microwave is made uniform by repeating reflection in the heating chamber 103, but immediately after the irradiation, the microwave is first reflected by the inner wall of the heating chamber 103. At this time, if the mounting means 111 is arranged in such a configuration that the microwave transmission direction 113 and the radiant heating mounting portion mounting direction 112 intersect as shown in FIG. 7, the microwave radiated from the microwave radiating portion 108. Will directly collide with the mounting means 111 at the interference position 701, which will be an obstacle to microwave radiation. Therefore, in order to prevent the attachment means 111 arranged for radiant heating cooking from becoming a factor that impedes uniformity when performing microwave heating, a micro that is a source for determining the microwave radiation direction 603 as shown in FIG. It is necessary to arrange the wave transmission direction 113 and the radiation heating mounting portion mounting direction 112 so as to be substantially the same direction.

  The necessity of this arrangement is, for example, when an experiment is performed in which a beaker in which water is put in the heating chamber 103 (eg, 100 cc injection into a cylindrical glass beaker having a diameter of 50 mm) is evenly arranged to check the temperature rise, In the arrangement, the temperature rise of all the beakers is substantially equal, but in the case of FIG. 7, it can be confirmed that the temperature rise is biased due to the influence of the attachment means 111.

  As described above, in the state where the microwave is guided into the heating chamber 103 by the heating chamber input unit 107 at the end portion of the waveguide, and the microwave transmitted through the waveguide 106 is a traveling wave with few standing waves. The microwave is radiated into the heating chamber 103 by the microwave radiating portion 108 provided in the waveguide to heat the object to be heated. Because it can radiate, it is possible to uniformly heat the object to be heated without using a rotating mechanism, and when the heating chamber 103 is used for radiant heating cooking, mounting a mounting portion for radiant heating By configuring the direction 112 to be substantially the same direction as the microwave transmission direction 113, it is possible to provide a microwave heating apparatus in which the attachment means 111 does not hinder uniformity during microwave heating. Kill.

  Further, by arranging a plurality of the microwave radiating portions 108 symmetrically with respect to the center of the heating chamber, the amount of radiation to the object to be heated 102 can be made symmetrical and microwave radiation can be performed uniformly.

Further, the total amount of microwaves input from the heating chamber input unit 107 to the heating chamber 103 is 10% or less of the total amount of microwaves radiated from the microwave radiating unit, so that the microwave used for heating the object to be heated is used. A large amount of wave can be secured and the traveling wave can be made more dominant.

  Further, in the heating chamber input unit 107 including the termination part 115 and the termination radiation part 116, the distance between the termination part 115 and the center of gravity of the termination radiation part 116 is an odd multiple of (approximately ¼ of the waveguide wavelength in the waveguide). By adopting a distant configuration, an antinode wavelength-based standing wave antinode is placed at the center of gravity of the terminal radiating portion to make it easy to emit the microwave from the terminal radiating portion 116, and the microwave transmitted through the waveguide is a traveling wave. It can be.

  Further, since the terminal radiating unit 116 also functions as the microwave radiating unit 108, the heating chamber input unit 107 can be configured in a compact manner.

  In this embodiment, the heater is used as the heating means 109 for radiant heating cooking. However, a microwave absorber is attached to the radiant heating mounting unit 110, and the radiant heating mounting is performed by microwaves. It is good also as a structure which the mounting part 110 for radiation heating fulfill | performs the function of the heating means 109 by comprising so that the part 110 can be heated.

Note that when heating the object to be heated 102 with a light load, since the microwave absorbed by the load is small, the microwave radiated from the microwave radiating unit 108 once passes through the microwave radiating unit 108 and is heated. Returns to the waveguide 106. The microwave transmitted through the waveguide 106 is apparently transmitted at the guide wavelength λg, but the original microwave is a wave of wavelength λ ₀ of the microwave supply means. As described above, in the state where the microwave is returned from the heating chamber 103 through the microwave radiating unit 108, the microwave supply means 105 has a constant oscillation wavelength λ ₀ base in the vicinity of the terminal end 115 of the heating chamber input unit 107. A wave is formed. Therefore, in the case of a microwave heating apparatus that places importance on light load heating performance, the distance between the terminal portion 115 constituting the heating chamber input unit 107 and the center of gravity of the terminal radiation unit 116 is the oscillation wavelength of the microwave supply means 105. it may be configured away odd multiple of approximate 1/4 of λ _0.

  In the present embodiment, the mounting means 111 has been described as a rail-shaped convex portion. However, the mounting means 111 is formed by squeezing the wall surface of the heating chamber 103 or is attached to the vicinity of the wall surface of the heating chamber 103 with metal, resin, or the like. It may be formed as a separate member. Moreover, you may be comprised so that it may support with a some protrusion rather than rail shape.

  In the present embodiment, the configuration in which the heating chamber input portion 107 is formed by the termination portion 115 and the termination radiation portion 116 has been described. However, the microwave transmitted by the waveguide 106 is guided to the heating chamber, and the traveling wave has an advantage. Other configurations may be used as long as the configuration is as follows.

(Embodiment 2)
FIG. 4 is an explanatory diagram for explaining the arrangement of the microwave radiating portions of the microwave heating apparatus according to the second embodiment of the present invention, and the arrangement of the microwave radiating portions 108 having a shape that radiates circularly polarized waves. It is explanatory drawing. In the drawings, the same reference numerals are given to the portions showing the same operations as those in (Embodiment 1). The basic operation in (Embodiment 2) is the same as that in (Embodiment 1). The operation and action will be described below.

In the present embodiment, the microwave radiating portion 108 is shaped to radiate circularly polarized waves as shown in FIG. Circular polarization is a technique widely used in the field of mobile communication and satellite communication. Examples of familiar use include an ETC (Electronic Toll Collection System) “non-stop automatic toll collection system” and the like. Circular polarization is a microwave in which the polarization plane of the electric field rotates with respect to the traveling direction of the radio wave, and when the circular polarization is formed, the direction of the electric field continues to change with time. The radiation angle of the microwave radiated into the inside continues to change, and the electric field strength does not change with time.

  Thereby, compared with the microwave heating by the linearly polarized wave used in the conventional microwave heating apparatus, the microwave is dispersed and radiated over a wide range so that the object to be heated can be microwave heated uniformly. become.

  In particular, there is a strong tendency for uniform heating in the circumferential direction of circular polarization. Note that circularly polarized waves are classified into two types, that is, right-handed polarization (CW: clockwise) and left-handed polarization (CCW: counterclockwise) from the direction of rotation, but there is no difference in heating performance.

  By utilizing the above feature and radiating circularly polarized microwaves through the microwave radiation unit 108, the heating distribution in the heating chamber 103 can be made more uniform. In order to output circularly polarized waves from the microwave radiating portion 108 provided in the waveguide 106, as shown in FIG. 9, two slits having a width are intersected at the center, and the microwave transmission direction is set. It is necessary to arrange the shape inclined 45 degrees with respect to the waveguide 106 at a position that does not pass through the tube axis 901 in the microwave transmission direction.

  As described above, in the present embodiment, the microwave radiating unit 108 is configured to radiate circularly polarized waves, so that microwaves that have spread from the microwave radiating unit are radiated into the heating chamber 103. The microwave radiation to the object to be heated 102 can be made uniform over a wider range.

  In the present embodiment, the shape of the microwave radiating unit 108 that radiates circularly polarized waves has been described with reference to the shape shown in FIG. 9, but the shape is not limited to that shown in FIG. Any shape can be used.

  Further, by arranging the terminal radiating section as an opening that matches the tube axis 901 where the microwave transmitted by TE10 is strongest, like the terminal radiating section 1001 shown in FIG. 10, the terminal radiation at the heating chamber input section 107 is reduced. It can be made easier.

  As described above, since the microwave heating device of the present invention can uniformly irradiate an object to be heated, the microwave heating device can also be applied to uses such as a microwave heating device that performs heating processing and sterilization of food.

DESCRIPTION OF SYMBOLS 101 Case 102 To-be-heated object 103 Heating chamber 104 Mounting part 105 Microwave supply means 106 Waveguide 107 Heating chamber input part 108 Microwave radiation part 109 Heating means 110 Radiation heating mounting part 111 Attachment means 112 For radiation heating Placement part mounting direction 113 Microwave transmission direction 114 Door 115 Termination part 116 Termination radiation part 401 Traveling wave 501 Termination radiation part 601 Traveling wave component 602 Radiation component 603 Microwave radiation direction 701 Interference position 901 Tube axis 902 Microwave radiation part 903 Terminal radiation part 1001 Terminal radiation part

Claims (7)

A heating chamber for storing the object to be heated;
A placement section for placing the object to be heated;
Microwave supply means for supplying microwaves to the heating chamber;
A waveguide for transmitting the microwave supplied from the microwave supply means to the heating chamber;
A heating chamber input for guiding microwaves passing through the waveguide at the end of the waveguide to the heating chamber;
A plurality of microwave radiating portions arranged in a microwave transmission direction between the microwave supply means and the heating chamber input portion to radiate microwaves passing through the waveguide to the object to be heated in the heating chamber; ,
Heating means for radiation heating cooking;
A detachable mounting portion for radiant heating attached to the inside of the heating chamber in order to place an object to be heated during radiant heating cooking by the heating means,
An attachment means for attaching the radiation heating mounting portion;
The microwave heating apparatus according to claim 1, wherein a mounting direction of the radiant heating mounting portion for mounting the radiant heating mounting portion by the mounting means is substantially the same direction as the microwave transmission direction. The microwave heating device according to claim 1, wherein a plurality of the microwave radiating portions are arranged symmetrically with respect to the center of the heating chamber. The microwave according to claim 1 or 2, wherein a total amount of microwaves input to the heating chamber from the heating chamber input unit is 10% or less of a total amount of microwaves radiated from the microwave radiation unit. Heating device. The heating chamber input section is composed of a termination section and a termination radiation section, and a distance between the termination section and the center of gravity of the termination radiation section is an odd multiple of approximately 1/4 of the waveguide wavelength of the waveguide. Item 4. The microwave heating apparatus according to any one of Items 1 to 3. The heating chamber input section includes a termination section and a termination radiation section, and the distance between the termination section and the center of gravity of the termination radiation section is an odd multiple of approximately 1/4 of the oscillation wavelength of the microwave supply means. Item 4. The microwave heating apparatus according to any one of Items 1 to 3. The microwave heating device according to claim 4 or 5, wherein the terminal radiating unit also functions as the microwave radiating unit. The microwave heating device according to any one of claims 1 to 6, wherein the microwave radiating unit has a shape that radiates circularly polarized waves.