WO2012070211A1

WO2012070211A1 - Microwave heating device

Info

Publication number: WO2012070211A1
Application number: PCT/JP2011/006434
Authority: WO
Inventors: 澁谷　昌樹; 河合　祐; 近藤　龍太; 西村　誠
Original assignee: パナソニック株式会社
Priority date: 2010-11-25
Filing date: 2011-11-18
Publication date: 2012-05-31
Also published as: EP2645001B1; EP2645001A1; JPWO2012070211A1; EP2645001A4; JP5874040B2

Abstract

In order to suppress heat generation in a gridiron (4) which is a net body and attain efficient heating with less energy loss, a heating cooker of the present invention has the gridiron so configured that an outer frame (21) and bridge members (20) configuring the gridiron are provided outside the vicinities of antinodes of standing waves (SW) generated in a heat chamber (1) so as to open the vicinities of the antinodes of the standing waves (SW).

Description

Microwave heating device

The present invention relates to a microwave heating apparatus that performs microwave heating.

In a conventional microwave heating apparatus, for example, in a heating cooker that cooks food to be heated, which is food, in order to float the heated object from the bottom of the heating chamber to a desired position, welding is performed by combining metal bars. A configuration using a network body (rotating network) is proposed (for example, see Japanese Patent Laid-Open No. 9-145044 (Patent Document 1)).

JP-A-9-145044 Japanese Utility Model Publication No. 55-059209

The cooking device described in Patent Document 1 places a glass rotating dish on a rotating net in the microwave heating mode, and a metal square dish in the rotating net in the oven heating mode. It is configured so that the object to be heated can be placed at a desired position in the heating chamber and cooked by heating.

In the conventional cooking device described in Patent Document 1, for example, a circular mesh body 100 having a fine mesh as shown in FIG. 12 is provided in the heating chamber. In the microwave heating mode, a standing wave is generated in the heating chamber of the cooking device by the microwave from the antenna and the reflected wave from the wall surface. For this reason, the net-like member 101 constituting the metal net 100 is arranged in a region near the antinode of the standing wave generated in the heating chamber in the microwave heating mode (region where the electric field is strong). As a result, in the microwave heating mode, a large current flows through the mesh member 101 of the mesh body 100, the mesh body 100 generates heat, and energy loss occurs. As a result, the conventional heating cooker has been a factor of deteriorating the heating efficiency.

In addition, a conventional cooking device has a configuration in which a grill net is provided as a metal net for placing an object to be heated housed in a heating chamber (for example, Japanese Utility Model Sho 55- No. 059209 (Patent Document 2)). FIG. 13 is a plan view showing a configuration of a general grill net 102 provided in a heating chamber in a conventional cooking device. As shown in FIG. 13, the grill net 102 has a configuration in which many rod-like members 104 are arranged at narrow intervals with respect to the outer frame 103 corresponding to the shape of the heating chamber. Also in such a grill 102, a region near the antinode of the standing wave generated in the heating chamber in the microwave heating mode (a region indicated by “MA” as an example in FIG. 13) is a metal grill 102. The rod-shaped member 104 which comprises is arrange | positioned. As a result, in the microwave heating mode, there is a problem that a large current flows through the rod-like member 104 of the grill 102 and the grill 102 generates heat abnormally. Therefore, when a grill is used in the microwave heating mode in the conventional cooking device, a large energy loss occurs and the heating efficiency of the cooking device is deteriorated.

The present invention solves the above-described problems in the conventional microwave heating apparatus, and provides a high-efficiency microwave heating apparatus that suppresses abnormal heat generation in a mesh body or the like disposed in a heating chamber and reduces energy loss. The purpose is to do.

The microwave heating apparatus of the present invention includes a heating chamber for heating an object to be heated,
A microwave generator for supplying microwaves into the heating chamber;
A grill that is a net made of a metal rod-like member for placing the object to be heated in the heating chamber;
The grill is composed of an outer frame fixed at a predetermined position in the heating chamber, and a bridging material fixed to the outer frame,
The outer frame and the bridging material are provided in areas other than the vicinity of the standing wave antinode so that the vicinity of the antinode of the standing wave generated in the heating chamber opens in the grill.

The present invention configured as described above is a high-efficiency microwave heating apparatus that suppresses abnormal heat generation in the grille and prevents energy loss in the microwave heating mode without large current flowing through the bridging material. Can be provided.

The microwave heating device of the present invention can provide a high-efficiency heating device with less energy loss by suppressing abnormal heat generation in a net or the like disposed in the heating chamber.

Front sectional view showing the microwave heating apparatus according to the first embodiment of the present invention. The top view which shows the grill in the microwave heating apparatus of Embodiment 1 which concerns on this invention Cross-sectional schematic diagram along line III-III in the grill shown in FIG. Sectional view taken along line IV-IV in the grill shown in FIG. The top view which shows the grill net used in the microwave heating apparatus of Embodiment 2 which concerns on this invention The top view which shows the grill of another structure used in the microwave heating apparatus of Embodiment 2 which concerns on this invention The top view which shows the grill of another structure used in the microwave heating apparatus of Embodiment 2 which concerns on this invention The top view which shows the grill of another structure used in the microwave heating apparatus of Embodiment 2 which concerns on this invention Main part sectional drawing seen from the side of the heating cooker of Embodiment 2 which concerns on this invention The top view which shows the grill net in the heating cooker of Embodiment 3 which concerns on this invention Sectional drawing of the principal part seen from the side surface of the heating cooker of Embodiment 3 which concerns on this invention The perspective view which shows the rotation net | network which is a net | network body used in the conventional microwave heating apparatus. The top view which shows the grill net which is the net body used in the conventional microwave heating device

A first invention is a heating chamber for heating an object to be heated;
A microwave generator for supplying microwaves into the heating chamber;
A microwave heating apparatus comprising a grill made of a metal rod-like member for placing the object to be heated in the heating chamber,
The grill is composed of an outer frame fixed at a predetermined position in the heating chamber, and a bridging material fixed to the outer frame,
The outer frame and the bridging material are provided in areas other than the vicinity of the standing wave antinode so that the vicinity of the antinode of the standing wave generated in the heating chamber opens in the grill.
In the microwave heating apparatus of the first invention configured as described above, in the microwave heating mode, since a large current does not flow through the bridging material of the grill net, abnormal heat generation is suppressed and energy loss is small. It becomes a highly efficient heating device.

In the second invention, in particular, in the first invention, at least one of the outer frame and the bridging material is provided in the vicinity of the node of the standing wave. In the second invention configured as described above, almost no current flows through the outer frame and / or the bridging material provided in the vicinity of the node, so that no abnormal heat is generated in the grill and high energy loss is low. An efficient microwave heating apparatus can be provided.

In the third invention, in particular, in the first or second invention, the bridging material is provided at a position separated by 3/8 or more of the wavelength of the standing wave from the inner wall of the heating chamber. The microwave heating apparatus according to the third aspect of the present invention configured as described above can reliably avoid the vicinity of ¼ of the wavelength of the standing wave from the inner wall of the heating chamber, which is the position of the antinode of the standing wave. Therefore, it is possible to provide a highly efficient microwave heating apparatus that suppresses heat generation in the grill and has little energy loss.

In a fourth aspect of the invention, in particular, in any one of the first to third aspects of the invention, a rail portion for inserting the grill net into the heating chamber is provided in the heating chamber. An insulating structure is provided between the rail portion and the grill. In the microwave heating apparatus of the fourth invention configured as described above, since the rail portion and the grill are insulated, the electric field is difficult to concentrate, abnormal heat generation is suppressed, and energy loss is reduced. Less efficient heating device.

In a fifth aspect of the invention, in particular, in the grill of the first aspect of the invention, the plurality of bridging members are fixed in parallel to the outer frame, and the adjacent bridging members are formed by a single bar-shaped member, An end portion of the rod-shaped member is configured not to protrude from the outer frame toward the side wall of the heating chamber. The microwave heating apparatus of the fifth invention configured as described above is configured such that the end of the rod-shaped member does not protrude into the heating chamber, so that the electric field in the grill is difficult to concentrate, and abnormal heat generation occurs. It becomes a highly efficient heating device with little energy loss.

In the sixth invention, in particular, the bridging material in the fifth invention is formed by forming a rod-like member in an annular shape. In the microwave heating apparatus of the sixth invention configured as described above, since there is no end portion in the bridging material, abnormal heating in the grill is eliminated, and the heating apparatus is highly efficient with little energy loss.

In the seventh invention, in particular, the ring of the bridging material in the sixth invention has a long and narrow track shape. 7th invention comprised in this way reduces the manufacturing cost by shortening the bridging distance in the bridging material with respect to the outer frame as much as possible by leaving the straight part like a track shape (elongated annular shape), It is possible to provide a highly efficient microwave heating apparatus with little deflection when an object to be heated is placed and low energy loss.

In the eighth invention, in particular, the bridging material in the fifth invention is formed in a meandering shape. The eighth invention thus configured can provide a high-efficiency microwave heating apparatus with reduced welding locations, reduced heat generation due to the concentration of the electric field at the welding locations, and less energy loss.

In the ninth aspect of the invention, in particular, the bridging material in any one of the fifth to eighth aspects of the invention is fixed so as to contact the inside of the outer frame. In the ninth invention configured as described above, there is no gap formed by the crossing of the bridging material and the outer frame, the electric field is less concentrated in the gap in the grill, and heat is less generated, resulting in less energy loss. A highly efficient microwave heating apparatus can be provided.

In the tenth aspect of the invention, in particular, the arc portion of the bridging member according to any one of the sixth to eighth aspects of the invention is arranged so as to protrude to the outside of the outer frame. The tenth aspect of the invention thus configured is configured so that the arc portion of the bridging material protrudes, and the end of the bridging material does not protrude, so there is no abnormal heat generation in the grill net, A highly efficient microwave heating apparatus with little energy loss can be provided.

The eleventh invention is particularly configured such that the grill net in the first invention makes point contact with the heating chamber. The eleventh aspect of the invention thus configured can be configured to have a wide gap where electric field concentration is unlikely to occur in a portion other than the point contact portion. In terms of processing, it is very difficult to form both the contact surface of the grill and the heating chamber so as to be in parallel and linear contact. However, in the eleventh aspect of the invention, the grill net and the heating chamber are configured to be in point contact with each other so that a slight gap does not occur between the grill net and the heating chamber. With this configuration, concentration of the electric field is prevented, abnormal heat generation is suppressed, and a highly efficient microwave heating apparatus with little energy loss is obtained.

According to a twelfth aspect of the invention, in particular, in the eleventh aspect of the invention, the outer frame is provided with a protrusion so that the grill net is in point contact with the rear wall of the heating chamber. As described above, when the contact surface between the grill net and the back wall of the heating chamber is in a line contact state, it is extremely difficult to form both the contact surfaces in parallel and linearly. However, a narrow gap is generated, and the electric field may concentrate in the gap. However, according to the twelfth aspect of the present invention, the point of contact is formed on the contact surface between the grill net and the back wall of the heating chamber, thereby preventing concentration of the electric field, suppressing abnormal heat generation, and reducing energy loss. A low-efficiency microwave heating apparatus can be provided.

In a thirteenth aspect, in particular, in the eleventh aspect, a hemispherical protrusion is provided on the back wall so that the grill net is in point contact with the back wall of the heating chamber. As described above, when the contact surface between the grill net and the back wall of the heating chamber is in a line contact state, it is very difficult to form both of the contact surfaces in parallel and linearly. There is a possibility that a narrow gap is generated and the electric field is concentrated in the gap. In the thirteenth aspect of the invention, the contact surface between the grill net and the back wall of the heating chamber is configured to make point contact, so that concentration of the electric field is prevented, abnormal heat generation is suppressed, and energy loss is low. An efficient microwave heating apparatus can be provided.

In a fourteenth aspect of the invention, in particular, in the twelfth aspect of the invention, the protrusions formed on the outer frame of the grill net are formed by bending a part of a rod-like member into a U shape. According to the fourteenth aspect of the invention thus configured, since the protruding portion that becomes the point contact portion can be formed simply by bending the rod-shaped member in the grill net into a U shape, the manufacturing is easy and the manufacturing cost is reduced. Can be reduced. In addition, when the protrusion is provided on the grill by welding, it may be removed during use. However, in the microwave heating apparatus of the fourteenth invention, the protrusion is integrated with the grill, and therefore used. Protruding part can not be taken out and it becomes a highly reliable heating device

In a fifteenth aspect of the invention, in particular, in any one of the eleventh to fourteenth aspects of the invention, a rail portion for inserting the grill net into the heating chamber is provided in the heating chamber, and the rail portion and the rail It is configured to make point contact with the grill. As described above, when the contact surface between the rail portion and the grille is in line contact as described above, it is very difficult to form both of the contact surfaces in parallel and linearly. There is a possibility that a narrow gap is formed and the electric field is concentrated in the gap. However, in the microwave heating apparatus of the fifteenth aspect of the invention, since the point between the rail part and the grille is in point contact, the concentration of the electric field between the rail part and the grille is prevented. In addition, it suppresses abnormal heat generation and becomes a highly efficient heating device with little energy loss.

Hereinafter, preferred embodiments of the microwave heating apparatus of the present invention will be described with reference to the accompanying drawings. In the microwave heating device of the following embodiment, a microwave oven with an oven function will be described as a heating cooker, but this microwave oven is an example, and the microwave heating device of the present invention is such an electronic device. It is not limited to the range, but includes various heating devices using dielectric heating. In the following embodiment, although the specific structure of a heating cooker is demonstrated, this invention is not limited to the structure of embodiment, The structure based on the same technical idea is included.

(Embodiment 1)
FIG. 1 is a front cross-sectional view showing a microwave oven with an oven function as a cooking device which is a microwave heating apparatus according to Embodiment 1 of the present invention.

The microwave oven with an oven function that is the heating cooker according to the first embodiment includes a door (not shown) that opens and closes to the front and back of the object to be heated, and the object to be heated 5 that is sealed and accommodated by the door. A heating chamber 1 for microwave heating.

In the heating cooker according to the first embodiment shown in FIG. 1, the heating chamber 1 for storing and heating food or the like to be heated 5 is configured by enamelling the surface of a steel plate. Inside the heating chamber 1, an upper heater 2 and a lower heater 3 are provided. In the heating space between the upper heater 2 and the lower heater 3, a grill 4 formed by combining and welding stainless steel bars is provided so as to be able to be taken in and out of the heating chamber 1. In addition, a plurality of

rails

12 and 13 are provided on both side wall surfaces of the heating chamber 1 so that the grill 4 can be disposed at a plurality of upper and lower positions in the heating chamber 1. In the oven heating mode, a food or the like to be heated 5 is placed on the grill 4 housed in the heating chamber 1 and heated so as to be sandwiched between the upper heater 2 and the lower heater 3. It is. In the oven heating mode, a saucer for receiving the broth from the article to be heated 5 may be provided between the grill 4 and the lower heater 3.

The corner of the inner wall surface of the heating chamber 1 is formed with a curved surface with an R, and the bottom surface of the heating chamber 1 is formed in a large arc shape (in FIG. 1, the curved surface configuration of the bottom surface is not shown). ing). In addition, although the wall surface of the heating chamber 1 in Embodiment 1 demonstrated in the example which performed enamel coating, you may perform the coating which has another heat resistance.

Further, as the wall surface material of the heating chamber 1, stainless steel or PCM steel plate can be used, and as the grill 4, a steel material or the like subjected to plating treatment can be used.

In the heating cooker according to the first embodiment, a magnetron 6 as a microwave generator is provided in the upper right side of the heating chamber 1 so as to output in the horizontal direction. Microwaves generated in the magnetron 6 are transmitted through the waveguide 14 and radiated into the heating chamber 1 from the rotating antenna 11 coupled to the waveguide 14. In the microwave heating apparatus of the first embodiment, the food that is the object to be heated 5 is heated by performing microwave heating and at least one of radiant heat and convection heat by the upper heater 2 and the lower heater 3. It is the structure which can do. In the first embodiment, the microwave generator includes an antenna 11 and a waveguide 14 in addition to the magnetron 6, and generates microwaves and supplies the generated microwaves to the heating chamber 1. including.

The upper heater 2 is provided with an upper heater thermocouple 7 that is an upper heater temperature detecting portion so as to be in contact with the surface thereof. The upper heater thermocouple 7 is covered with a metal tube so as not to be affected by the microwave from the magnetron 6, and enables highly accurate heater temperature detection regarding the upper heater 2.

Further, the lower heater 3 is provided with a lower heater thermocouple 8 that is a lower heater temperature detecting portion so as to be in contact with the surface thereof. A thermistor 9 that is a temperature detecting means in the heating chamber 1 is fixed to the wall surface of the heating chamber 1. Each of the upper heater thermocouple 7, the lower heater thermocouple 8, and the thermistor 9 is electrically connected to the control unit 10. The control unit 10 controls energization to the upper heater 2 and the lower heater 3 based on outputs from the upper heater thermocouple 7, the lower heater thermocouple 8, and the thermistor 9, and the heating cooker according to the first embodiment. Has a configuration in which the heating amount in the oven heating mode can be controlled.

1 has an output portion that is led out in the horizontal direction and is joined to the end of the waveguide 14. The waveguide 14 has a vertical portion including an end portion to which the output portion of the magnetron 6 is joined, and a horizontal portion extending in the horizontal direction, and an L-shaped internal passage is formed. In the waveguide 14, a rotating antenna 11 is provided as a radio wave stirring means near the center in the horizontal direction of the heating chamber 1. The shaft portion 11B of the rotating antenna 11 is mechanically connected to the rotating shaft of the motor 18, and the antenna portion provided at the end of the shaft portion 11B via the shaft portion 11B of the rotating antenna 11 by driving the motor 18. 11A is configured to rotate. The waveguide 14 is provided with a power supply port 17, and a conical dome 15 is provided so as to surround the power supply port 17. The shaft portion 11 B of the rotating antenna 11 passes through the power feeding port 17 of the waveguide 14, and the antenna portion 11 A is disposed inside the dome 15.

As described above, the rotating antenna 11 includes the antenna portion 11A and the shaft portion 11B, and the antenna portion 11A is formed of a substantially circular plate having a diameter of about φ62 with a metal plate having a thickness of 1 mm. The antenna portion 11A has a shaft portion 11B fixed at a position deviated by about 12 mm from the center of the disk.

The motor 18 side portion of the shaft portion 11B is made of fluororesin, and the antenna portion 11A side portion is made of metal. In the first embodiment, the metal portion on the antenna portion 11A side of the shaft portion 11B protrudes about 11 mm inside the waveguide 14 and protrudes about 15 mm toward the heating chamber 1 through the power supply port 17 of the dome 15. The projecting end portion is provided with an antenna portion 11A. The clearance between the shaft portion 11b and the power feeding port 17 is secured by 5 mm or more.

In addition, in the heating cooker of Embodiment 1, although the magnetron 6, the rotation antenna 11, the waveguide 14, the dome 15, and the electric power feeding port 17 are demonstrated in the example provided in the upper side of the heating chamber 1, The present invention is not limited to such a configuration. For example, the heating chamber 1 can be provided on the bottom surface side or the side surface side, and the installation direction of the waveguide 14 or the like can be set in any direction. Is possible.

In the heating cooker according to the first embodiment, a cover 16 made of mica is provided at the lower end of the dome 15 so that dirt from the heated object 5 does not adhere to the rotating antenna 11. The cover 16 is configured to be detachable from an insulator hook 19 fixed to the heating chamber 1.

In the heating cooker according to the first embodiment, the upper heater 2 is arranged so as not to be directly under the lower opening of the dome 15 so that the upper heater 2 is not directly affected by microwaves.
In the configuration of the first embodiment, an example in which mica, which is a low-loss dielectric material, is used as the cover 16 has been described. However, a ceramic or glass can be similarly configured.

FIG. 2 is a plan view showing the grill 4 in the cooking device which is the microwave heating apparatus according to the first embodiment of the present invention. In FIG. 2, the lower side is the user side (door side) in the heating cooker, and the upper side is the back side. FIG. 2 shows an example of a standing wave SW generated in the heating chamber 1 in a contour line. A hatched area having a deep color indicates a region where the amplitude of the standing wave is large (region having a strong electric field: MA). Show.

In FIG. 2, the grill 4 is composed of an outer frame 21 made of a metal φ6 bar and a plurality of bridging members 20 (20A, 20B) made of a metal φ3 bar. Yes. As shown in FIG. 2, in the grill net 4, insulating members 22 are fixed to left and right side portions (21 B) of the outer frame 21. Further, two bridging members 20A are provided in parallel with the front side and the back side side parts (21A) of the outer frame 21 so as to bridge the left and right side parts (21B) of the outer frame 21. . Further, twelve bridging members 20B are welded and joined to each other so as to be bridged orthogonally to the two bridging members 20A with a predetermined interval described later.

The distance between the left and right side portions (21B) of the outer frame 21 and each of the bridging members 20B at both ends is set to be approximately 3/8 or more of the wavelength λ of the standing wave SW. Further, as shown in FIG. 2, the twelve bridging members 20B are arranged with a wide interval (first interval: A) every three. A narrow interval between the three is defined as a second interval B. In the configuration of the first embodiment, the first interval A is arranged so as to sandwich the anti-MA near the amplitude of the standing wave SW that is 80% or more of the strongest electric field, and the wavelength of the standing wave SW. It is set to be approximately 1/4 of λ. Further, the second interval B, which is a narrow interval in the bridging material 20B, is set to be approximately 1/8 of the wavelength λ of the standing wave SW.

Here, the standing wave is a wave generated inside the heating chamber, and is basically generated when the radiated wave from the antenna and the reflected wave from the wall surface of the heating chamber overlap. A standing wave is a wave that appears to be oscillating, stopping in place, with almost no waveform. Therefore, the standing wave generation state is determined to some extent by the configuration of the heating chamber, the configuration of the antenna, and the like.

In addition, in the heating space of the heating chamber 1 of the heating cooker according to the first embodiment, as described above, the distance between the bridging material 20B (the first region) between the region sandwiching the anti-MA near the standing wave and the other regions. The first interval A and the second interval B) are different. However, in the present invention, it is sufficient if the bridging material 20B is arranged in a region avoiding the anti-MA near the antinodes of the standing wave SW generated in the heating chamber 1, and if the condition is satisfied, etc. The same effect can be obtained even at intervals.

Note that the wavelength of the standing wave SW varies depending on the shape of the internal space of the heating chamber 1, and the wavelength of the standing wave SW in the left-right direction of the heating chamber 1 in the configuration of the first embodiment is about 14 cm. It was. Therefore, 3/8 of the wavelength λ of the standing wave is about 5.3 cm, 1 / 4λ is about 3.5 cm, and 1 / 8λ is about 1.8 cm.

In addition, the standing wave SW generated in the heating chamber 1 varies depending on the food that is the object to be heated 5 placed on the grill 4 in addition to the inner surface configuration of the heating chamber 1. However, in the outer peripheral region of the grill 4, the occurrence position of the antistatic MA near the standing wave SW is rarely changed.

FIG. 3 is a schematic cross-sectional view taken along line III-III in the grill 4 shown in FIG. 2, and schematically shows the standing wave SW generated inside the heating chamber 1.

As shown in FIG. 3, in the heating chamber 1, the microwave radiated from the antenna and the microwave reflected in the heating chamber 1 overlap with each other so that the waveform stops and vibrates on the spot without progressing the waveform. The standing wave SW that appears is generated. Therefore, in the heating chamber 1, a standing wave SW having a node position where the electric field overlaps and hardly vibrates and the amplitude is zero and an antinode position where the amplitude is greatly displaced is formed.

As shown in FIGS. 2 and 3, in the heating cooker according to the first embodiment, four of the bridging materials 20B of the grill net 4 are arranged near the node of the standing wave SW. Further, the insulating member 22 made of insulator is fixed with the outer frame 21 interposed therebetween, and is configured to be slidable on the plurality of rails 12 (12A, 12B) fixed to the heating chamber 1. Therefore, the insulating member 22 electrically insulates between the outer frame 21 and the rail 12 of the grill 4 and between the outer frame 21 and the heating chamber 1.

In the standing wave SW shown in FIG. 3, the standing wave SW in which five antinodes and six nodes are formed is shown. It varies depending on various conditions. Therefore, the structure of the grill 4 is appropriately changed according to the specifications of the heating cooker.

As the material of the insulating member 22 in the first embodiment, an example using an insulator has been described, but a material such as glass or plastic can be used as long as it is an insulating member.

The wavelength λ of the standing wave referred to here represents the periodic length including two antinodes and two nodes, and the periodic length in the case of one antinode and one node. Becomes ½ wavelength.

FIG. 4 is a cross-sectional view of a principal part of a component such as the grill 4 in the heating chamber 1 taken along line IV-IV in FIG. In FIG. 4, the left side is the front side where the door is provided, and the right side is the back side of the heating chamber 1.
As shown in FIG. 4, the outer frame 21 of the grill 4 is arranged so as to be sandwiched between the lower rail 12 (12 A, 12 B) and the upper rail 13. As described above, since the grill 4 is configured to be sandwiched between the upper and

lower rails

12 and 13, it is possible to prevent the grill 4 from being inclined while being pulled out of the heating chamber 1.

Next, the operation and action of the heating cooker according to the first embodiment configured as described above will be described.

In the heating cooker according to the first embodiment, when the microwave heating mode is selected by the user and the heating operation start switch is turned on, the microwave is formed in the magnetron 6, and the microwave from the magnetron 6 is generated. It is transmitted to the waveguide 14. The microwave transmitted through the waveguide 14 is supplied to the heating chamber 1 while being agitated by the rotating antenna 11 that is irradiated with the rotating antenna 11 and rotated by the motor 18.

The microwave supplied into the heating chamber 1 irradiates the object to be heated 5, for example, food, the food absorbs the microwave, and the food is heated by microwave.

On the other hand, in the cooking device of the first embodiment, when the oven heating mode is selected by the user and the heating operation start switch is turned on, the upper heater 2 and the lower heater 3 are energized to generate heat. When the upper heater 2 and the lower heater 3 generate heat, the radiant heat from the upper heater 2 and the lower heater 3 is transmitted to the food in the heating chamber 1, and the food is heated in the oven.

As described above, in the heating cooker according to the first embodiment, the shape of the grill 4 disposed in the heating chamber 1 for placing the object to be heated 5 and cooking by heating is the inside of the heating chamber 1. Is formed in consideration of the standing wave SW generated in the above. Specifically, the grill 4 is formed so that the vicinity of the antinode of the standing wave SW generated in the heating chamber 1 is opened, and the outer frame 21 and the bridging material 20 in the grill 4 are arranged in the heating chamber 1. Is provided in an area other than the anti-MA near the anti-MA near the standing wave SW. As a result, in the heating cooker according to the first embodiment, the outer frame 20 and the bridging material 20 of the grill 4 are not arranged in the region where the electric field is strong in the microwave heating mode, so the grill 4 in the microwave heating mode. An unusually large current does not flow through the heat generating device, and heat generation of the grill 4 is greatly suppressed, and a highly efficient cooking device with little energy loss can be provided.

Further, the heating cooker according to the first embodiment is configured such that most of the bridging material 20B is arranged in the vicinity of the node of the standing wave SW generated in the heating chamber 1. Therefore, since current does not flow so much in the bridging material 20B provided in the vicinity of the node, in the microwave heating mode, there is little heat generation in the bridging material 20B, and high efficiency is realized as a whole in the heating cooker. be able to.

In the heating cooker of the first embodiment, the bridging

materials

20A and 20B are configured to be separated from the inner wall surface of the heating chamber 1 by 3/8 or more of the wavelength λ of the standing wave SW. With this configuration, a bridging material is provided in the region of the quarter of the wavelength λ of the standing wave SW from the inner wall surface of the heating chamber 1 that is the position of the antinode of the standing wave SW generated in the heating chamber 1. Since 20A and 20B are not arranged, heat generation in the grill 4 is suppressed and high efficiency is realized in the microwave heating mode.

As described above, in the heating cooker according to the first embodiment, the grill 4 is provided with the insulating member 22 between the outer frame 21 and the lower rail 12 and between the outer frame 21 and the heating chamber 1. Insulated structure. If the grill 4 is not insulated, the electric field concentrates in a small gap and abnormal heat generation occurs. However, in the heating cooker of the first embodiment, since the grill 4 has an insulating structure, the rail 12 and the grill 4 and the heating chamber 4 and the rail 12 are reliably insulated. Thus, electric field concentration is difficult to occur, heat generation is suppressed, and high efficiency can be realized.

In addition, in the heating cooker of Embodiment 1, although the example of the insulation structure demonstrated between the side wall of the heating chamber 1, and the grill 4, the insulation between the back wall of the heating chamber 1 and the grill 4 was carried out. By setting it as a structure, it becomes a structure which can further suppress the heat generation in the grill 4.

As described above, as described in the heating cooker according to the first embodiment, the microwave heating apparatus of the present invention suppresses abnormal heat generation in a mesh body or the like disposed in the heating chamber, and has high efficiency with low energy loss. The heating device can be provided.

(Embodiment 2)
As described above with reference to FIG. 13 for the grill 102 in the conventional microwave heating apparatus, the conventional grill 102 has a large number of metal rod-like members 104 arranged closely. Therefore, as shown in FIG. 13, the conventional grill net 102 has a configuration in which the protruding end faces 104 a and 104 b of a large number of rod-like members 104 are exposed in the heating chamber. For this reason, in the microwave heating mode, the electric field concentrates on the projecting end faces 104a and 104b of the rod-shaped member 104 and generates heat, resulting in a large energy loss, which deteriorates the heating efficiency of the heating cooker.

It should be noted that it is conceivable to form a grill by punching a metal steel plate so that no protruding end face is formed in the grill, but in such a configuration, the electric field tends to concentrate on the edge portion in the punched hole. For this reason, there is a problem that heat is generated at the edge portion, resulting in energy loss.

In the microwave heating apparatus according to the second embodiment of the present invention, as described in the first embodiment, the grill 4 is formed in consideration of the standing wave SW generated in the heating chamber 1. At the same time, it is a heating device that relaxes the concentration of the electric field in the grill 4 and has high energy efficiency with less energy loss.

Hereinafter, a cooking device as a microwave heating apparatus according to a second embodiment of the present invention will be described with reference to the attached drawings. In addition, in the heating cooker of the following Embodiment 2, although the microwave oven with an oven function is demonstrated, this microwave oven is an illustration and is limited to such a microwave oven as a microwave heating device of this invention. It is not intended to include a heating device using dielectric heating.

In the description of the heating cooker according to the second embodiment below, differences from the configuration of the heating cooker according to the first embodiment shown in FIG. 1 will be described, and the same components as those in the heating cooker according to the first embodiment will be described. Components having functions and configurations are denoted by the same reference numerals, and the description of Embodiment 1 is applied to the detailed description thereof.

In the heating cooker that is the microwave heating apparatus of the second embodiment, the difference from the configuration of the first embodiment is the shape and configuration of the grill net 4, and the other configurations are the same as those of the heating cooker of the first embodiment. The same. Therefore, in Embodiment 2, the shape and configuration of the grill 4 will be described.

Four types of grill nets (4A, 4B, 4C, 4D) used in the heating cooker according to the second embodiment of the present invention are shown in plan views in FIGS.

The grill net 4A shown in FIG. 5 includes a substantially rectangular outer frame 21 and a plurality of bridging members 200A formed in a ring shape in a long and narrow shape. As shown in FIG. 5, each of the plurality of bridging members 200 A is arranged in parallel and is provided so as to bridge the opposing long side portions of the substantially rectangular outer frame 21. The grill net 4A shown in FIG. 5 is configured such that the straight portion of the vertically long portion of the bridging material 200A extends to the outside of the outer frame 21, and the arc portions on both ends of the bridging material 200A do not intersect the outer frame 21. Has been.

The grill 4A shown in FIG. 5 is formed of an outer frame 21 made of a metal φ6 bar and a bridging material 200A made of a metal φ3 bar. The five bridging members 200A provided so as to bridge the opposing long side portions in the outer frame 21 are formed in an annular and elongated track shape (substantially track elliptical shape), and the straight portion of the bridging member 200A is the outer frame. The arc portions extending from the outer side 21 to the outer ends of the bridge member 200 A are disposed outside the outer frame 21.

6 has a substantially rectangular outer frame 21 and a plurality of bridging members 200B formed in an annular shape and in a track shape. As shown in FIG. 6, each of the plurality of bridging members 200 B is arranged in parallel and is joined to opposing long side portions of the substantially rectangular outer frame 21. The grill 4B shown in FIG. 6 is configured such that each of the bridging materials 200B is inscribed in the outer frame 21. That is, the grill 4B shown in FIG. 6 is joined so as to be in contact with the inner side of the outer frame 21 at one point on the outer periphery of the arc portion that is both ends of each annular and long track-shaped bridging member 200B.

The grill 4B shown in FIG. 6 is formed of an outer frame 21 made of a metal φ6 bar and a bridge material 200B made of a metal φ3 bar. The five bridging members 200B provided so as to bridge the opposing long side portions in the outer frame 21 are formed in an annular and elongated track shape (substantially track elliptical shape), and the bridging member 200B is formed inside the outer frame 21. It is joined so that the arc part of

7 has a substantially rectangular outer frame 21 and a bridging material 200C formed in a folded meandering shape. The straight portion of the bridging material 200 C extends to the outside of the outer frame 21, and the arc portions that are both end portions of the bridging material 200 C are configured not to intersect the outer frame 21.

7 is formed of an outer frame 21 made of a metal φ6 bar and a bridge material 200C made of a metal φ3 bar. In the grill 4C shown in FIG. 7, the bridging material 200C is joined to the outer frame 21 in a meandering manner, and the straight portion of the bridging material 200C extends to the outside of the outer frame 21, and the bridging material 200C The arc portion is disposed outside the outer frame 21. However, both end portions of the folded meandering bridge member 200 C are joined to the outer frame 21, and preferably joined to the inner side of the outer frame 21.

8 has a substantially rectangular outer frame 21 and a bridging material 200D formed in a folded meandering shape. As shown in FIG. 8, the arc portion of the bridging material 200 D is joined to the outer frame 21 in abutment, and the outer circumference of the arc portion of the bridging material 200 D is joined so as to be in contact with the inner surface of the outer frame 21.

8 is formed of an outer frame 21 made of a metal φ6 bar and a bridge material 200D made of a metal φ3 bar. In the grill 4D shown in FIG. 8, the bridging material 200D is provided in a meandering manner inside the outer frame 21, and the arc portion of the bridging material 200D is joined to the inner side of the outer frame 21 by abutment. Further, both end portions of the folded meandering bridge member 200 C are joined to the inner side of the outer frame 21.

As described above, in the heating cooker according to the second embodiment, the interval between the rod-shaped members in the bridging materials 200A to 200D of the grills 4A to 4D is determined based on the standing wave λ generated in the heating chamber 1. The length is set to about 1/4 or more of λ. In the configuration of the second embodiment, the number of rod-shaped members in the grill 4 is appropriately changed depending on the size of the heating chamber 1 and the article to be heated.

FIG. 9 is a cross-sectional view of the main part viewed from the side surface of the cooking device of the second embodiment. In FIG. 9, the case where the grill 4B shown in FIG. 6 is used is illustrated. In FIG. 9, the left side is the front side where the door is provided, and the right side is the back side of the heating chamber 1.

As shown in FIG. 9, the outer frame 21 of the grill 4 (4A to 4D) is arranged so as to be sandwiched between the lower rail 12 and the upper rail 13 in the vertical direction. The upper rail 13 prevents the grill 4 from being inclined while being pulled out of the heating chamber 1. Also, below the grill net 4, hemispherical portions 23 that are in point contact with the rails 12 are provided at two locations on one side and at four locations on the left and right.

Next, the operation and action of the heating cooker according to the second embodiment configured as described above will be described.

In the heating cooker according to the second embodiment, when the microwave heating mode is selected by the user and the heating operation start switch is turned on, the microwave is formed in the magnetron 6, and the microwave from the magnetron 6 is generated. It is transmitted to the waveguide 14. The microwave transmitted through the waveguide 14 is supplied to the heating chamber 1 while being agitated by the rotating antenna 11 that is irradiated with the rotating antenna 11 and rotated by the motor 18.

On the other hand, in the cooking device of the second embodiment, when the oven heating mode is selected by the user and the heating operation start switch is turned on, the upper heater 2 and the lower heater 3 are energized to generate heat. When the upper heater 2 and the lower heater 3 generate heat, the radiant heat from the upper heater 2 and the lower heater 3 is transmitted to the food in the heating chamber 1, and the food is heated in the oven.

As described above, in the microwave heating mode, when the end face of the metal rod-shaped member in the grill net is exposed in an acute angle state, the electric field concentrates at that portion and heat is generated, resulting in a large energy loss. Become. In the heating cooker according to the second embodiment, the grill net 4 is not configured to project an acute end face, and the grill net 4 is configured by an elongated annular or folded meandering member. The part where the electric field concentrates is greatly limited. As a result, the heating cooker according to the second embodiment is a highly efficient heating cooker in which heat generation in the grill 4 is suppressed and energy loss is small.

In the configuration of the second embodiment, as shown in FIGS. 6 and 8, when the arc portions of the bridging portions 200 B and 200 D are in contact with the outer frame 21, the bridging materials 200 B and 200 D and the outer frame 21 are formed. There is no gap formed by crossing. For this reason, in the cooking device having the configuration shown in FIGS. 6 and 8, the concentration of the electric field is reduced, energy loss is reduced, and the heating cooking device with high heating efficiency is obtained.

Further, in the configuration of the second embodiment, as shown in FIG. 8, the bridging material 200 D is formed in a meandering manner, and the arc portion of the bridging material 200 D is joined to the inside of the outer frame 21 in a butt manner. The outer periphery of the arc portion of the bridging material 200 D is joined so as to contact the inner periphery of the outer frame 21. For this reason, the cooking device having the configuration shown in FIG. 8 can be configured so that the thickness of the grill 4 can be made thin, and both sides of the grill 4 can be placed on the surface on which the object to be heated 5 can be placed. In addition, since there are few steps, the cleaning is easy.

In the configuration of the second embodiment, as shown in FIGS. 5 and 7, when the straight portions of the bridging portions 200 A and 200 C extend to the outside of the outer frame 21, the arc portions and the outer frame 21 in the bridging portions 200 A and 200 C If the gap between the two and the gap becomes large and dirt is accumulated in such a gap, cleaning becomes easy and the maintenance management becomes easy.

In the configuration of the second embodiment, the longitudinal direction of the bridging materials 200A to 200D is arranged so as to be the front-rear direction of the heating chamber 1. However, any of the horizontal direction of the heating chamber 1, the oblique direction of the heating chamber 1, etc. Even if the longitudinal direction of the bridging materials 200A to 200D is arranged in the direction, the same effect can be obtained.

Further, in the configuration of the second embodiment, by setting the interval between the rod-shaped members in the bridging material 20 of the grill net 4 to ¼λ or more, the microwaves wrap around the grill net 4 and the heated object 5 Is configured to absorb microwaves from the lower side, and the heating cooker of the second embodiment is configured to achieve high efficiency.

As described above, in the configuration of the second embodiment, the grill net 4 is provided with the hemispherical portion 23 so as to slide on the lower rail 12. If the hemispherical portion is not provided, the outer frame 21 and the rail 12 are in a line contact state. In processing, it is very difficult to form all the contact surfaces of the left and right outer frames 21 and the rails 12 in parallel and in a completely linear shape. Therefore, since these contact surfaces are actually bent, they are not in a line contact state but in a contact state with a slight gap. As a result, electric field concentration is likely to occur in a slight gap generated between the contact surfaces of the outer frame 21 and the rail 12, which causes a large energy loss.

In the configuration of the second embodiment, by providing the hemisphere portion 23 on the grill net 4, the hemisphere portion 23 of the grill net 4 comes into contact with the lower rail 12 at two points on one side, and the left and right are aligned at four positions. Point contact. For this reason, the outer frame 21 of the grill 4 is arranged with a large gap except for the portion in point contact with the rail 12. Therefore, in the configuration of the second embodiment, since the overall gap between the grille 4 and the rail 12 is increased, electric field concentration between the grille 4 and the rail 12 is prevented, and high efficiency is achieved. Can be realized.

In the configuration of the second embodiment, the example has been described in which the hemisphere portion 23 is provided on the grill net 4 at two locations on one side and four locations on the left and right, but the present invention is not limited to such a configuration. It is possible to support the grill 4 if there are at least three places, or the same effect can be obtained by increasing the number of the hemispherical portions 23 in order to improve the balance of the grill 4 when the article 5 to be heated is placed. It is done.

In the configuration of the second embodiment, the example in which the hemisphere portion 23 is provided in the grill 4 has been described. However, an insulator may be provided instead of the hemisphere portion 23 to prevent electric field concentration. good. In this case, the insulator is provided in a region of the grill 4 between the lower rail 12 and a region close to the wall surface of the heating chamber 1, thereby preventing concentration of the electric field and increasing the heating efficiency. be able to.

Also, as shown in FIG. 9, in the configuration of the second embodiment, the upper rails 12 (12A, 12B) and the lower rails 13 are alternately arranged. Thus, by arranging the upper rails 12 (12A, 12B) and the lower rails 13 alternately, the concentration of the electric field generated between the rails can be prevented and high efficiency can be realized. .

Furthermore, in the configuration of the second embodiment, the corner portion of the wall surface of the heating chamber 1 is configured by a curved surface (R), and the bottom surface is formed in a large arc shape so that the microwave reflected by the wall surface of the heating chamber 1 is covered. The configuration is such that the object to be heated 5 is easily irradiated with the reflected wave in the direction of the heated object 5, and more efficient heating can be performed.

As described above, as described in the heating cooker according to the second embodiment, the microwave heating apparatus of the present invention has less exposure of the end face of the rod-shaped member of the grill net in the heating chamber, so that the concentration of the electric field is alleviated. Therefore, heat generation in the grill is reduced, resulting in highly efficient cooking with less energy loss.

(Embodiment 3)
In the configuration of the heating cooker of the above-described second embodiment, the hemisphere portion 23 is provided in the grill net 4 so that the grill net 4 is in point contact with the lower rail 12 (12A, 12B). explained. The microwave heating apparatus according to the third embodiment of the present invention has a configuration in which a hemisphere portion is provided in the grill 4 and the concentration of the electric field generated between the grill 4 and the heating chamber 1 is further reduced. .

As described in the second embodiment, when the hemispherical portion 23 is not provided, the outer frame 21 of the grill net 4 and the lower rail 12 are in a line contact state. It is very difficult to form all the contact surfaces of the rail 21 and the rail 12 in parallel and in a linear shape. For this reason, the outer frame 21 and the rail 12 are not in a line contact state but in a contact state having a slight gap. As a result, electric field concentration tends to occur in a slight gap generated between the contact surfaces, resulting in energy loss. As a result, there is a problem that the heating efficiency of the cooking device deteriorates.

Further, as described in the first embodiment, the insulating member 22 (see FIG. 3) is provided between the grill 4 and the rail 12 so that no discharge occurs between the outer frame 21 and the rail 12. ) Is a preferable measure. However, the configuration in which the insulating member 22 is provided has a problem that the number of parts increases, the manufacturing process increases, and the apparatus becomes expensive. Furthermore, there has been a problem that the weight of the grill 4 becomes heavy and the handling becomes difficult.

The microwave heating apparatus according to the third embodiment of the present invention solves the above-described problem, and provides a low-cost heating apparatus that has high energy efficiency with low energy loss and is easy to handle. .

In the heating cooker that is the microwave heating apparatus of the third embodiment, the difference from the configuration of the first embodiment is the shape and configuration of the grill net 4, and the other configurations are the same as those of the heating cooker of the first embodiment. The same. Therefore, in Embodiment 3, the shape and configuration of the grill 4 will be described.

In the description of the heating cooker of the third embodiment below, the same reference numerals are given to the components having the same functions and configurations as the components in the heating cooker of the first embodiment, and the detailed description thereof is carried out. The description of Form 1 is applied.

FIG. 10 is a plan view showing grill net 4E in the heating cooker according to the third embodiment of the present invention.

A grill net 4E shown in FIG. 10 is formed by an outer frame 21 made of a metal φ6 bar and a bridging material 20 made of a metal φ3 bar. Eight bridging members 20 are provided so as to bridge the opposing long side portions of the substantially rectangular outer frame 21.

In the outer frame 21, two U-shaped protrusions 21C are formed so as to protrude toward the back wall 1A side of the heating chamber 1. The two protruding portions 21C are provided in the vicinity of the left and right end portions of the outer frame 21 at positions facing the back wall 1A of the heating chamber 1, and are formed by bending the outer frame 21.

When the grill 4E configured as described above is mounted at a predetermined position in the heating chamber 1 (see FIG. 10), the two protruding portions 21C are in point contact with the back wall 1A of the heating chamber 1, respectively. At this time, the gap L between the portion of the outer frame 21 on the back wall 1A side and the back wall 1A of the heating chamber 1 is set to about 5 mm excluding the protruding portion 21C.

In the heating cooker of the third embodiment, the interval between the rod-like members in the bridging material 20 of the grill 4E is a length that is approximately ¼ or more of the wavelength λ based on the standing wave λ generated in the heating chamber 1. Is set. In the configuration of the third embodiment, the number of rod-shaped members in the grill 4 is appropriately changed depending on the size of the heating chamber 1 and the object to be heated.

FIG. 11 is a cross-sectional view of the main part viewed from the side surface of the cooking device of the third embodiment. In FIG. 11, the left side is the front side where the door is provided, and the right side is the back side of the heating chamber 1.

In FIG. 11, the outer frame 21 of the grill 4E is arranged so as to be sandwiched between the lower rail 12 and the upper rail 13. The upper rail 13 prevents the grill 4E from being inclined while being pulled out of the heating chamber 1. Further, on the lower side of the outer frame 21, hemispherical portions 23 that make point contact with the rail 12 are provided at two locations on one side and at four locations on the left and right.

As shown in FIG. 11, when the grill 4 is inserted into the heating chamber 1 and the protruding portion 21 C is in contact with the back wall 1 A, the portion of the outer frame 21 on the back wall 1 A side and the heating chamber 1. A gap L is formed between the rear wall 1A. In the heating cooker according to the third embodiment, the gap L is set to about 5 mm. However, if the gap L is at least 3 mm, concentration of the electric field is prevented.

Next, the operation and action of the heating cooker according to Embodiment 3 configured as described above will be described.

In the heating cooker according to the third embodiment, when the microwave heating mode is selected by the user and the heating operation start switch is turned on, the microwave is formed in the magnetron 6, and the microwave from the magnetron 6 is generated. It is transmitted to the waveguide 14. The microwave transmitted through the waveguide 14 is supplied to the heating chamber 1 while being agitated by the rotating antenna 11 that is irradiated with the rotating antenna 11 and rotated by the motor 18.

On the other hand, in the heating cooker of the third embodiment, when the oven heating mode is selected by the user and the heating operation start switch is turned on, the upper heater 2 and the lower heater 3 are energized to generate heat. When the upper heater 2 and the lower heater 3 generate heat, radiant heat from the upper heater 2 and the lower heater 3 is transmitted to the food in the heating chamber 1, and the food is oven-heated.

As described above, in the configuration of the third embodiment, the grill net 4 is provided with the hemispherical portion 23 so as to slide on the rail 12. If the hemispherical portion is not provided, the outer frame 21 and the lower rail 12 are in a line contact state. However, it is very difficult to form all the contact surfaces of the left and right outer frames 21 and the rails 12 in parallel and in a linear shape in processing. Therefore, since these contact surfaces are actually bent, they are not in a line contact state but in a contact state with a slight gap. As a result, electric field concentration is likely to occur in a slight gap generated between the contact surfaces of the outer frame 21 and the rail 12, which causes energy loss.

In the configuration of the third embodiment, by providing the hemispherical portion 23 on the grill 4, the hemispherical portion 23 of the grill 4 contacts the lower rail 12 at two points on one side, and the left and right are aligned at four points. Point contact. For this reason, the outer frame 21 of the grill 4 is arranged with a large gap except for the portion in point contact with the rail 12. Therefore, in the configuration of the third embodiment, since the gap between the grille 4 and the rail 12 is wide (more than 5 mm), electric field concentration between the grille 4 and the rail 12 is prevented. High efficiency can be realized.

In the configuration of the third embodiment, the example has been described in which the hemispherical portion 23 is provided in the grill net 4 at two locations on one side and four locations on the left and right, but the present invention is not limited to such a configuration. It is possible to support the grill 4 if there are at least three places, or the same effect can be obtained by increasing the number of the hemispherical portions 23 in order to improve the balance of the grill 4 when the article 5 to be heated is placed. can get.

In the configuration of the third embodiment, the point of contact between the grill net 4 and the rail 12 reduces the frictional force between the grill net 4 and the rail 12 and makes it easier to pull out the grill net 4. Have

In the configuration of the third embodiment, by providing the outer frame 21 with a U-shaped projection 21C, the grill 4 is in point contact with the back wall 1A of the heating chamber 1 only at the projection 21C. . For this reason, the outer frame 21 is disposed with a large gap at a portion other than the protruding portion 21 C with respect to the back wall 1 C of the heating chamber 1. Therefore, in the configuration of the third embodiment, electric field concentration between the grill 4 and the heating chamber 1 can be prevented, and high efficiency can be realized.

In the configuration of the third embodiment, the protrusion 21C formed on the outer frame 21 is formed only by bending the outer frame 21 into a U-shape, so that the manufacturing is easy and the manufacturing cost can be reduced. In addition, since the protruding portion 21 C is integrated with the outer frame 21 and is not likely to be detached from the outer frame 21, the highly reliable grill 4 can be provided.

Further, in the configuration of the third embodiment, the example in which two U-shaped protrusions 21C are provided on the grill net 4 has been described, but the deformation when the grill net 4 is strongly pressed against the back wall 1C. For prevention, the number of protrusions 21C may be increased. The shape of the protruding portion 21C may be any shape that can alleviate the concentration of the electric field, and the same effect can be obtained by using a semicircular or triangular configuration in addition to the U shape.

In the configuration of the third embodiment, the example in which the protruding portion 21 C is formed on the grill net 4 has been described, but it may be provided on the back wall side of the heating chamber 1. In such a configuration, a hemispherical protrusion is formed on the back wall side of the heating chamber 1, and the outer frame 21 of the grill net 4 may be configured to make point contact with the protrusion. When the protrusion is formed on the back wall side of the heating chamber 1 in this way, the heating chamber 1 can be formed at the same time when the press chamber is manufactured, so that the manufacturing is easy and the manufacturing cost is greatly reduced. Can be planned.

Further, in the configuration of the third embodiment, the example in which the hemispherical portion 23 is configured as a separate member has been described. However, the outer frame 21 of the grill 4 may be bent into a U shape so as to protrude downward. . In this case, the same effect as when the hemispherical portion 23 is provided, and the configuration is further simplified, and the manufacturing cost can be reduced.

In the configuration of the third embodiment, the gap between the outer frame 21 of the grill 4 and the back wall 1A of the heating chamber 1 and the gap between the outer frame 21 and the lower rail 12 are point contact portions. Except for the example in which the gap is set to about 5 mm, if the gap is 3 mm or more, the concentration of the electric field is small and substantially the same effect can be obtained.

Further, in the configuration of the third embodiment, by setting the interval between the rod-shaped members in the bridging material 20 of the grill net 4 to ¼λ or more, the microwaves wrap around the grill net 4 and the heated portion 5 Becomes a structure which absorbs a microwave from the lower side, and the heating cooker of Embodiment 3 becomes a structure which can implement | achieve high-efficiency.

Further, as shown in FIG. 11, in the configuration of the third embodiment, the upper rails 12 (12A, 12B) and the lower rails 13 are alternately arranged. Thus, by arranging the

upper rails

12A, 12B and the lower rails 13 alternately, it is possible to prevent the concentration of the electric field generated between the rails and to achieve high efficiency.

Furthermore, in the configuration of the third embodiment, the corner portion of the wall surface of the heating chamber 1 is configured by a curved surface (R), and the bottom surface is formed in a large arc shape so that the microwave reflected by the wall surface of the heating chamber 1 is covered. The configuration is such that the object to be heated 5 is easily irradiated with the reflected wave in the direction of the heated object 5, and more efficient heating can be performed.

As described above, as described in the heating cooker according to the third embodiment, the microwave heating apparatus of the present invention prevents the concentration of the electric field generated in a slight gap and suppresses abnormal heat generation in the grill. Thus, a highly efficient heating device with little energy loss is obtained.

As described above, the microwave heating apparatus according to the present invention enables high-efficiency heating with little energy loss. Therefore, a microwave oven, an oven microwave oven, an electric oven, and a business as a cooking utensil using a microwave function The present invention can also be applied to various microwave heating devices for industrial use, for example, heating devices in industrial fields such as thawing devices and drying devices, ceramic heating, sintering devices, and biochemical reaction devices.

DESCRIPTION OF SYMBOLS 1 Heating chamber 2 Upper heater 3 Lower heater 4 Burning net 5 Heated object 6 Magnetron 10 Control part 11 Rotating antenna 12 Lower rail 13 Upper rail 20 Bridging material 21 Outer frame 22 Insulating member SW Standing wave MA Near standing wave antinode

Claims

A heating chamber for heating an object to be heated;
A microwave generator for supplying microwaves into the heating chamber;
A grill formed of a metal rod-like member for placing the object to be heated in the heating chamber,
The grill is composed of an outer frame fixed at a predetermined position in the heating chamber, and a bridging material fixed to the outer frame,
The outer frame and the bridging material are microwave heating devices provided in areas other than the vicinity of the standing wave antinode so that the vicinity of the antinode of the standing wave generated in the heating chamber opens in the grill.
The microwave heating apparatus according to claim 1, wherein at least one of the outer frame and the bridging material is provided near a node of the standing wave.
The microwave heating apparatus according to claim 1 or 2, wherein the bridging material is provided at a position separated by 3/8 or more of the wavelength of the standing wave from the inner wall of the heating chamber.
The rail part for inserting the said grill into the inside of the said heating chamber is provided in the inside of the said heating chamber, The insulation structure is provided between the said rail part and the said grill. The microwave heating device according to one item.
In the grill, a plurality of the bridging members are fixed in parallel to the outer frame, adjacent bridging members are formed by a single bar-shaped member, and an end of the bar-shaped member is heated from the outer frame to the heating frame. The microwave heating device according to claim 1, wherein the microwave heating device is configured not to protrude toward the side wall of the chamber.
The microwave heating apparatus according to claim 5, wherein the bridging material is formed by forming a rod-shaped member in an annular shape.
The microwave heating device according to claim 6, wherein the ring of the bridging material has an elongated track shape.
The microwave heating device according to claim 5, wherein the bridging material is formed in a meandering shape.
The microwave heating device according to any one of claims 5 to 8, wherein the bridging material is fixed so as to contact the inside of the outer frame.
The microwave heating device according to any one of claims 6 to 8, wherein an arc portion of the bridging member is disposed so as to protrude outside the outer frame.
The microwave heating apparatus according to claim 1, wherein the grill is configured to make point contact with the heating chamber.
The microwave heating apparatus according to claim 11, wherein a projection is provided on the outer frame so that the grill net is in point contact with a back wall of the heating chamber.
The microwave heating apparatus according to claim 11, wherein a hemispherical protrusion is provided on the back wall so that the grill net makes point contact with the back wall of the heating chamber.
The microwave heating device according to claim 12, wherein the protrusions formed on the outer frame of the grill net are formed by bending a part of a rod-shaped member into a U shape.
The rail part for inserting the said grill into the inside of the said heating chamber is provided in the inside of the said heating chamber, The structure of any one of the Claims 11 thru | or 14 comprised so that a point may contact between the said rail part and the said grill The microwave heating device according to claim 1.