JP2005019196A - High frequency heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high frequency heating device in which heating distribution by microwave is made uniform without driving rotatively. <P>SOLUTION: This is the high frequency heating device that heats a heating object in a heating chamber 22 by a microwave emitted from a magnetron 24. The microwave is introduced from an opening part 20 of a waveguide 19 into a distribution control chamber 18 and emitted uniformly into the heating chamber 22 from the surrounding of an antenna 21 provided in the distribution control chamber 18. By this structure, the uneven microwave transferred from the opening 20 of the waveguide 19 into the distribution control chamber 18 is partly interrupted by the antenna 21 and made to be irradiated from the end part of the distribution control chamber 18 surrounding the antenna 21 into the heating chamber 22, thereby the radiation direction of the microwave can be changed in the distribution control chamber 18 and thus uniform microwave can be emitted into the heating chamber 22. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency heating apparatus that heats an object to be heated by microwaves, and uniformizes a heating distribution without being driven to rotate.
[0002]
[Prior art]
In a microwave oven, which is a typical high-frequency heating device, various configurations have been put into practical use for uniformizing the heating distribution by microwaves. For example, a configuration (turn table) for rotating a mounting table on which an object to be heated is placed, and a microwave radiation direction by rotating an antenna 3 that is coaxially coupled with a shaft portion 2 protruding into a waveguide 1 as shown in FIG. And the like (rotating antenna), and the structure of stirring the microwave by the rotation of metal blades in the heating chamber (rotating stirrer).
[0003]
In addition, as shown in FIG. 12, the effect of mounting the metal pieces 7a and 7b in the vicinity of the radiation antenna 6 of the magnetron 5 in the waveguide 4 and the effect of the turntable 8 are combined to achieve more uniformity. Yes (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
JP-A-8-148273
[0005]
[Problems to be solved by the invention]
The conventional configuration has a rotation drive unit in any case, and parts such as a motor and a drive shaft are required, and power for driving is also required.
[0006]
In addition, rotating parts such as a turntable, rotating antenna, and rotating stirrer are arranged near the wall surface of the heating chamber and occupy a considerably large space. However, for products having not only a microwave oven function but also a heater heating function such as a recent microwave oven and toaster range, the rotation space is an obstacle, and it is difficult to arrange the heater at an optimal position. In particular, in the case of a radiant heater such as a tube heater used in an oven toaster, it is known that efficient heating can be achieved by bringing the upper heater and the lower heater as close as possible to the object to be heated. For example, when baking toast, it can be baked in a short time by placing a heater close to both the upper and lower surfaces of the pan. However, in the conventional configuration, the lower heater cannot be arranged in the center with the turntable or the rotating antenna arranged in the center of the bottom surface, and the upper heater is difficult to arrange in the rotating antenna or the rotating stirrer arranged in the center of the top surface. . In any case, not only the rotating parts but also the drive motor for transmitting the rotational force must be arranged in the vicinity of the rotating parts. Therefore, it is more difficult to arrange the heater.
[0007]
Moreover, in order to raise heater efficiency, the structure which makes the inside height low can be considered. This is because if the inside height is low, the distance between the upper heater and the food and the distance between the lower heater and the food can be reduced. However, when the inside height is lowered, it is difficult to make the heating distribution by the microwave uniform in a configuration without rotating parts. In general, most foods (objects to be heated) have a flat shape. Considering the case of heating flat foods, if microwaves are irradiated from the side wall or rear wall, the part on the side that irradiates microwaves However, heating will progress. On the other hand, when microwaves are irradiated from the bottom wall surface, the object to be heated and the bottom wall surface are so close that only the portion directly above the irradiated portion is heated. Therefore, in order to make the heating distribution uniform, it is always possible to know the ceiling wall surface that can maintain a certain distance from the object to be heated (especially from the center), and to irradiate uniform microwaves to make the distribution on the plane uniform. desirable.
[0008]
The present invention has been made to solve these problems, and an object of the present invention is to provide a high-frequency heating apparatus in which the heating distribution by microwaves is made uniform without being driven to rotate.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a high-frequency heating device according to the present invention is a high-frequency heating device that heats an object to be heated in a heating chamber with microwaves radiated from a magnetron. And is uniformly radiated from the periphery of the antenna provided in the distribution adjustment chamber into the heating chamber.
[0010]
As a result, the non-uniform microwave transmitted from the waveguide opening into the distribution adjustment chamber is partially blocked by the antenna and radiated from the end of the distribution adjustment chamber around the antenna to the heating chamber. Thus, the microwave radiation direction can be changed, and uniform microwaves can be radiated into the heating chamber.
[0011]
Therefore, it is possible to provide a high-frequency heating apparatus in which the heating distribution by microwaves is made uniform without being driven to rotate.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The high-frequency heating device according to claim 1 is a high-frequency heating device that heats an object to be heated in a heating chamber by microwaves radiated from a magnetron, and the microwave is guided from a waveguide opening to a distribution adjusting chamber, and the distribution It is configured to radiate uniformly from the periphery of the antenna provided in the adjustment chamber into the heating chamber.
[0013]
As a result, the non-uniform microwave transmitted from the waveguide opening into the distribution adjustment chamber is partially blocked by the antenna and radiated from the end of the distribution adjustment chamber around the antenna to the heating chamber. Thus, the microwave radiation direction can be changed, and uniform microwaves can be radiated into the heating chamber.
[0014]
Therefore, it is possible to provide a high-frequency heating apparatus in which the heating distribution by microwaves is made uniform without being driven to rotate.
[0015]
The high-frequency heating apparatus according to claim 2 is configured such that the distribution adjusting chamber is disposed at substantially the center of at least one of the front and rear directions and the left and right directions of the top surface of the heating chamber.
[0016]
This makes it easy to design the distribution adjustment chamber and the antenna because microwaves should be radiated symmetrically from the distribution adjustment chamber in at least one direction (in the direction of the central portion). Therefore, it becomes easy to radiate a uniform microwave into the heating chamber.
[0017]
In the high-frequency heating device according to claim 3, the outer shape of the opening and the antenna are different from each other.
[0018]
As a result, microwaves are radiated through passages having different shapes of the opening and the antenna, so that the direction of microwave radiation can be easily changed.
[0019]
In the high-frequency heating device according to the fourth aspect, the outer shape of the opening and the antenna are different in the number of vertices.
[0020]
As a result, one apex of the aperture and the antenna faces a portion different from the other apex, so that the microwave radiation direction can be easily changed in the vicinity thereof.
[0021]
In the high-frequency heating device according to the fifth aspect, the outer shape of the opening and the antenna are different from each other.
[0022]
Thereby, since one R of an opening and an antenna opposes another different R, the radiation | emission direction of a microwave can be easily changed in the periphery.
[0023]
The high-frequency heating device according to claim 6 is configured such that microwaves are radiated from four corners by making the opening substantially square and the outer shape of the antenna substantially circular.
[0024]
Thereby, the radiation direction of the microwave can be changed so that the microwave is emitted in at least four directions from the four corners formed by the four apexes of the opening and the circumference of the antenna.
[0025]
In the high-frequency heating device according to the seventh aspect, the opening and the outer shape of the antenna have the same size.
[0026]
As a result, the path of the microwave changes greatly due to a slight difference in shape between the aperture and the antenna, so that the influence of the difference in shape on the radiation direction of the microwave can be enhanced.
[0027]
In the high-frequency heating device according to the eighth aspect, the outer shape of the antenna is smaller than the wavelength λ of the microwave.
[0028]
As a result, the width of the waveguide is generally smaller than λ and, as a result, the width of the opening formed in the waveguide is also smaller than λ. Furthermore, since the outer shape of the antenna is relatively small as compared with general rotary drive parts, the antenna can be made compact.
[0029]
In the high-frequency heating device according to the ninth aspect, the outer shape of the antenna is approximately the same as the width of the waveguide.
[0030]
Thereby, since the opening formed in the waveguide is equal to or less than the width of the waveguide, the opening and the outer shape of the antenna can be easily set to the same degree. Furthermore, since the outer shape of the antenna is relatively small as compared with general rotary drive parts, the antenna can be made compact.
[0031]
In the high-frequency heating device according to a tenth aspect, the antenna has a distribution adjusting hole or cut.
[0032]
Thereby, it becomes possible to radiate | emit a microwave from a hole or a notch | incision, and can change the radiation | emission direction of a microwave still more easily.
[0033]
In the high-frequency heating device according to claim 11, the hole or the notch has a long shape in the longitudinal direction of the distribution adjusting chamber.
[0034]
Thereby, the microwave radiated into the heating chamber can be made uniform even from a distribution adjusting chamber having a long and short shape.
[0035]
In the high-frequency heating device according to a twelfth aspect, the length of the hole or the notch is set to about λ / 4 where λ is the wavelength of the microwave.
[0036]
As a result, the ratio of microwave radiation from the hole or notch is increased, and the effect of the hole or notch can be maximized.
[0037]
The high-frequency heating device according to claim 13 is configured such that the hole or the notch has a width of at least 5 mm.
[0038]
Thereby, even if a strong electric field is generated in the width direction of the hole or the notch, the dielectric breakdown can be prevented, so that it can be used safely.
[0039]
The high-frequency heating device according to a fourteenth aspect is configured such that a metal antenna is electrically insulated and fixed from the waveguide and the distribution adjusting chamber.
[0040]
Thereby, even if there is a strong electric field in the waveguide and a strong electric field in the distribution adjustment chamber, it is possible to prevent dielectric breakdown in the vicinity of the antenna, so that it can be used safely. In addition, since the antenna is fixed, it is not necessary to expand the space by rotation and to provide a separate drive unit, and the configuration is extremely simple and compact.
[0041]
The high-frequency heating apparatus according to claim 15 is configured such that the metal antenna is not axially coupled into the waveguide.
[0042]
As a result, the microwave is not drawn out by strong coaxial coupling as in a general rotating antenna, so there is no directivity as determined by the shape of the antenna itself, and therefore the microwave radiation is uneven. Hard to become.
[0043]
In the high-frequency heating device according to the sixteenth aspect, the distribution adjusting chamber has a heating chamber side wider than the waveguide side.
[0044]
Accordingly, the microwave radiation direction can be gradually expanded from the opening having a smaller area than the heating chamber and guided to the heating chamber, so that the microwave radiation into the heating chamber can be made more uniform.
[0045]
In the high-frequency heating device according to a seventeenth aspect, the distribution adjusting chamber is configured to widen the heating chamber side along the microwave transmission direction of the waveguide.
[0046]
Thereby, the heating distribution by the microwave is made more uniform with respect to the direction of the heating chamber corresponding to the microwave transmission direction of the waveguide.
[0047]
In the high-frequency heating device according to an eighteenth aspect, the distribution adjusting chamber has a length equivalent to the wavelength λ of the microwave in at least one of the width direction of the waveguide and the microwave transmission direction.
[0048]
This makes it possible to transmit microwaves of all modes unlike the waveguide, and the effect of the distribution adjustment chamber is enhanced, and the microwave radiation into the heating chamber is made uniform.
[0049]
In a high-frequency heating device according to a nineteenth aspect, the distribution adjusting chamber has a thickness not exceeding λ / 4 where λ is the wavelength of the microwave.
[0050]
As a result, the distance from the opening to the antenna can be made smaller than λ / 4, and the microwave resonance mode during this period can be prevented. Therefore, the microwave radiated from the opening of the waveguide can be smoothly and efficiently guided into the heating chamber, so that a desired heating distribution can be obtained. In addition, the thickness of the distribution adjusting chamber is reduced, and further downsizing is achieved.
[0051]
The high-frequency heating device according to claim 20 is configured such that the flat antenna is disposed at substantially the center in the thickness direction of the distribution adjusting chamber.
[0052]
As a result, the distance from the opening to the antenna and the distance from the antenna to the heating chamber can be made equal, so that the non-uniform emission of the microwave from the opening and the uniform emission of the microwave in the heating chamber can be reduced. Can be well matched.
[0053]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0054]
(Example 1)
1 to 4 show the configuration of the first embodiment of the present invention, FIG. 1 is a cross-sectional configuration diagram of the high-frequency heating device viewed from the front, FIG. 2 is a cross-sectional configuration diagram viewed from the right, and FIG. FIG. 4 and FIG. 4 are configuration diagrams showing only the aperture and the antenna.
[0055]
The left wall surface 9, the rear wall surface 10 and the right wall surface 11 are made of a common wall member, but this member is made of a material coated with fluorine in advance so that each wall surface is hard to get dirty and easy to wipe off. Yes. A horizontally long tube heater 13 (heating element) is mounted at the center lower portion of the bottom wall surface 12 and the periphery is covered with a reflecting plate 14 so as to equalize radiation heating from below. The ceiling wall surface 15 is provided with a tube heater 17 (heating element) in a horizontally narrowed aperture 16 on the front side, and the shape of the aperture 16 makes uniform radiation heating from above. Since both the bottom wall surface 12 and the ceiling wall surface 15 are heated by the tube heaters 13 and 17, they are constituted by other members not coated with fluorine.
[0056]
A metal distribution adjustment chamber 18 is disposed behind the ceiling wall surface 15 and substantially in the center in the left-right direction. The microwave transmitted through the waveguide 19 is guided into the distribution adjusting chamber 18 from the opening 20 formed on the upper surface, passes through the periphery of the antenna 21 fixed in the distribution adjusting chamber 18, and is heated. It is the structure radiated to. Here, the heating chamber 22 is formed by five wall surfaces (the left wall surface 9, the rear wall surface 10, the right wall surface 11, the bottom wall surface 12, and the ceiling wall surface 15), and is a space for heating an object to be heated (not shown). is there. The left wall surface 9, the rear wall surface 10, the right wall surface 11, the bottom wall surface 12, the ceiling wall surface 15, the distribution adjustment chamber 18, and the waveguide 19 that form the heating chamber 22 are electrically resistance welded (projection welding, spot welding) or caulked. Are joined mechanically and electrically conductively. The door 23 is configured to be able to open and close the heating chamber 22. The magnetron 24 generates microwaves from the radiation antenna 25, and the microwaves are transmitted from the center rear of the ceiling wall surface 15 into the heating chamber 22 through the waveguide 19, the opening 20, and the distribution adjustment chamber 18. In this configuration, an object to be heated (not shown) arranged in the heating chamber 22 is heated.
[0057]
In the present embodiment, while the magnetron 24 is arranged on the right side wall surface 11 side, the ceiling wall surface 15 clearly knows that the microwave is guided into the heating chamber 22, so even if the inside height is lowered, the heating distribution by the microwave is used. Can be made uniform to some extent.
[0058]
Further, when the magnetron 24 is arranged on the right wall surface 11 side, the components can be arranged together on the right wall surface 11 side as in the conventional case, so that efficient component arrangement can be performed. At the same time, the magnetron 24 does not have to be arranged on the ceiling wall surface 15 side, so that the dead space on the ceiling wall surface 15 side can be reduced, and a compact configuration can be realized particularly in the vertical direction. As described above, even if the inside height is lowered, there is no harmful effect, and it is easy to shorten the baking time for toast and the like by improving the heater performance by reducing the inside height.
[0059]
In this embodiment, the upper and lower heaters are optimized by optimizing the shape of the squeeze 16 for the tube heater 17 that is the upper heater and the reflector 14 for the tube heater 13 that is the lower heater. While improving the distribution, the height of the interior is reduced to about 145 mm to improve the efficiency (by the way, the interior width is 285 mm and the depth is 270 mm).
[0060]
For example, the toast (not shown) is placed on the top 26 mounted in the cabinet and can be efficiently baked from both the upper and lower sides, and the toast is baked even with a household commercial power supply (100V, 15A). The time can be reduced to about 3 minutes, similar to an oven toaster. Moreover, at the time of microwave heating, food may be placed on the top 26, or food may be placed after the plate 27 is placed on the top 26 as shown in FIG.
[0061]
As shown in FIG. 4, the antenna 21 has a flat plate shape whose outer shape is processed into a circle having a diameter of 80 mm, and has cuts 28 a and 28 b toward the center of the circle. The cuts 28a and 28b are both 17.5 mm wide and about 30 mm long, and the angle they make is about 160 degrees. On the other hand, the opening 20 is located slightly in front of the waveguide 19, and both the opening 20 and the antenna 21 are disposed in front of the distribution adjusting chamber 18. The opening 20 is about 68 mm in the vertical direction of FIG. 3 and about 80 mm in the horizontal direction of FIG.
[0062]
On the other hand, the waveguide 19 is disposed at the center in the depth direction (vertical direction in FIG. 3) of the distribution adjusting chamber 18 and to the right in the horizontal direction (horizontal direction in FIG. 3). The waveguide 19 has a width (vertical direction in FIG. 3) of about 80 mm, as in the case of a general microwave waveguide, and is positioned forward and backward with respect to the depth (vertical direction in FIG. 3) 108 mm of the distribution adjusting chamber 18. There will be steps of 14 mm.
[0063]
Further, the length of the distribution adjusting chamber 18 in the left-right direction in FIG. Furthermore, the thickness of the distribution adjusting chamber 18 (vertical direction in FIGS. 1 and 2) is about 15 mm, and the antenna 21 is mounted at the approximate center in the thickness direction.
[0064]
The mounting method of the antenna 21 is a material with low high-frequency dielectric loss, such as PPS or mica, and is electrically insulated from the waveguide 19 or the distribution adjusting chamber 18 while being held, while being distributed, the distribution adjusting chamber 18, the waveguide 19, the ceiling. What is necessary is just to fix to either the wall surface 15 etc., and is not illustrated in a present Example.
[0065]
Further, a cover 29 is attached to the lower side of the distribution adjusting chamber 18 so as to be closed from the inside of the heating chamber 22.
[0066]
Furthermore, since the antenna 21 is located in the vicinity of the microwave radiated from the waveguide 19 through the opening 20, the antenna 21 may be made of a material with low high-frequency magnetic loss such as aluminum or a material obtained by subjecting an iron plate to aluminum plating. desirable.
[0067]
As described above, according to the configuration of the present embodiment, nonuniform microwaves transmitted from the opening 20 of the waveguide 19 into the distribution adjustment chamber 18 are partially blocked by the antenna 21 and the distribution adjustment chamber 18 around the antenna 21 is blocked. Since the radiation is emitted from the end portion into the heating chamber 22, the radiation direction of the microwave can be changed in the distribution adjusting chamber 18, and the uniform microwave can be emitted into the heating chamber 22.
[0068]
Therefore, it is possible to provide a high-frequency heating apparatus in which the heating distribution by microwaves is made uniform without being driven to rotate.
[0069]
Further, the distribution adjusting chamber 18 is arranged at a substantially central portion in the left-right direction of the ceiling wall surface 15.
[0070]
Accordingly, since it is sufficient to radiate microwaves symmetrically from the distribution adjusting chamber 18 at least in the left-right direction, the design can be facilitated such that the cuts 28a, 28b of the antenna 21 can be formed symmetrically. Therefore, it becomes easy to radiate a uniform microwave into the heating chamber.
[0071]
Further, the outer shapes of the opening 20 and the antenna 21 are different from each other. In particular, the opening 20 is substantially square, and the outer shape of the antenna 21 is substantially circular so that microwaves are emitted from the four corners.
[0072]
Thereby, the radiation direction of the microwave can be changed so as to radiate the microwave in at least four directions from the four corners formed by the four apexes of the opening 20 and the circumference of the antenna.
[0073]
Moreover, the external shape of the opening 20 and the antenna 21 is made into the same magnitude | size.
[0074]
As a result, the path of the microwave greatly changes due to a slight difference in shape between the opening 20 and the antenna 21, which increases the influence of the difference in shape on the radiation direction of the microwave. On the other hand, for example, when the antenna is much smaller than the aperture, it can be easily imagined that the microwave radiation direction is hardly changed even if the shape of the antenna is slightly changed.
[0075]
The outer shape of the antenna 21 is about 80 mm, which is smaller than the wavelength λ of the microwave (about 120 mm in the case of a general microwave oven), and especially about the same as the width of the waveguide.
[0076]
Usually, the width of the waveguide is smaller than the wavelength λ, and in this embodiment, the width is 80 mm, which is equivalent to that of a general microwave oven. As a result, the width of the opening 20 is about 68 mm, which is smaller than 80 mm. Further, if the outer shape of the antenna 21 is about 80 mm, the general rotating antenna and the rotating stirrer are 120 mm or more, and the general turntable can be configured to be considerably smaller than that of 250 mm or more.
[0077]
The antenna 21 is configured to have distribution adjustment cuts 28a, 28b.
[0078]
Thereby, it is possible to radiate microwaves not only from the outer periphery of the antenna 21 but also from the cuts 28a and 28b, and the radiation direction of the microwaves can be changed more easily.
[0079]
In particular, the cuts 28a and 28b have a shape that is long in the longitudinal direction of the distribution adjusting chamber 18 (left and right direction in FIG. 3).
[0080]
Thereby, the microwave radiated | emitted in the heating chamber 22 was able to be made uniform.
[0081]
The length of the cut is configured to be about λ / 4 (= about 30 mm), where the wavelength of the microwave is λ (= about 120 mm).
[0082]
As a result, microwave radiation from the cuts 28a and 28b can be increased, and the effect of the cut can be maximized.
[0083]
Further, the cuts 28a and 28b are configured to have a width of 17.5 mm.
[0084]
Thereby, even if a strong electric field is generated in the width direction of the cuts 28a and 28b, the dielectric breakdown can be prevented, so that it can be used safely.
[0085]
In addition, the antenna 21 which is aluminum-plated on an aluminum or iron plate is configured to be electrically insulated from the waveguide 19 and the distribution adjusting chamber 18 and fixed.
[0086]
Thereby, although there is a strong electric field in the waveguide and a strong electric field in the distribution adjustment chamber, dielectric breakdown in the vicinity of the antenna 21 can be prevented, so that it can be used safely. Further, since the antenna 21 is fixed, there is no need to expand the space by rotation and to provide a separate drive unit, and the configuration is extremely simple and compact.
[0087]
Further, the antenna 21 is configured not to be axially coupled in the waveguide 19.
[0088]
Accordingly, the structure of the general rotating antenna 3 shown in FIG. 11 (strong coaxial coupling is performed by the hole 31 provided on the metal shaft 2 and the metal wall surface 30, and the microwave is extracted and radiated from the tip portion 32. Greatly different). In FIG. 11, the directivity is determined by the shape of the tip 32 itself, but in the present embodiment, the direction of microwave radiation is not the shape of the antenna 21 itself but the relationship between the antenna 21 and the aperture or distribution adjustment chamber. Since the directivity due to the shape of the antenna 21 itself can be eliminated, non-uniformity is unlikely to occur.
[0089]
In addition, the distribution adjusting chamber 18 has a heating chamber 22 side wider than the waveguide 19 side.
[0090]
Thereby, the microwave radiation direction can be gradually expanded from the opening 20 having a smaller area than the heating chamber 22 and guided to the heating chamber 22, so that the microwave radiation into the heating chamber 22 can be made more uniform. .
[0091]
In addition, the distribution adjusting chamber 18 is configured to widen the heating chamber 22 side along the microwave transmission direction of the waveguide 19 (from right to left in FIG. 3).
[0092]
Thereby, the heating distribution by the microwave is made more uniform in the horizontal direction of the heating chamber 22.
[0093]
Further, the distribution adjusting chamber 18 is a heating chamber having a width of 108 mm in the width direction (vertical direction in FIG. 3) and a top surface of about 103 mm, a bottom surface 143 mm, and an average of 123 mm in the microwave transmission direction (left and right direction in FIG. 3). It is the shape which becomes wide toward. In any direction, it can be said that the length is approximately the same as the microwave wavelength λ = 120 mm.
[0094]
Thereby, the distribution adjusting chamber 18 can transmit microwaves of all modes unlike the waveguide. The waveguide transmits microwaves in a single mode such as the TE10 mode by setting the width to less than λ and the height to less than λ / 2, but the distribution adjusting chamber 18 is much more than the waveguide. In addition, it has a wide area, and the mode is not easily limited. Therefore, there is an effect of preventing a standing wave from being generated and becoming non-uniform due to a single mode, and microwave radiation into the heating chamber 22 can be made uniform.
[0095]
The distribution adjusting chamber 18 has a thickness (vertical direction in FIGS. 1 and 2) of about 15 mm and a thickness that does not exceed λ / 4 (= 30 mm).
[0096]
As a result, the distance from the opening 20 to the antenna 21 can be made smaller than λ / 4, and the microwave resonance mode is prevented from occurring during this time. Therefore, resonance does not occur between the opening 20 of the waveguide 19 and the antenna 21, and the microwave radiated from the opening 20 of the waveguide 19 is smoothly and efficiently guided into the heating chamber 22. The desired heating distribution can be obtained. Further, the thickness of the distribution adjusting chamber 18 can be reduced, and further downsizing can be achieved.
[0097]
Further, the flat antenna 21 is arranged at the approximate center in the thickness direction of the distribution adjusting chamber 18.
[0098]
Thereby, since the distance from the opening 20 to the antenna 21 and the distance from the antenna 21 to the heating chamber 22 can be made equal, the non-uniform emission of the microwave from the opening 20 and the inside of the heating chamber 22 can be achieved. The uniform radiation of the microwave can be well matched.
[0099]
(Example 2)
FIG. 5 is a configuration diagram showing only the opening and the antenna of the high-frequency heating device according to the second embodiment of the present invention. The opening 32 is a quadrangle, the antenna 33 is an octagon, and the antenna 33 has a larger number of vertices.
[0100]
Thereby, at the four corners of the opening 32, the apex of the opening 32 faces the side of the antenna 33, and the triangular gap 34 is formed large, so that the microwave radiation from the gap 34 increases, and the microwave The radiation direction of is changed.
[0101]
Example 3
FIG. 6 is a configuration diagram showing only the opening and the antenna of the high-frequency heating device according to the third embodiment of the present invention. The opening 35 has a hexagonal shape, and the antenna 36 has a triangular shape. The antenna 35 has a shape with fewer vertices.
[0102]
As a result, a large trapezoidal gap 37 is formed in the vicinity of the three sides of the antenna 35. Therefore, microwave radiation from the gap 37 increases, and the microwave radiation direction is changed. .
[0103]
(Example 4)
FIG. 7 is a configuration diagram showing only the opening and the antenna of the high-frequency heating device according to the fourth embodiment of the present invention.
[0104]
The opening 38 is a quadrangle, and the antenna 39 has a shape having a large R at the apex of the quadrangle.
[0105]
As a result, the apex of the opening 38 faces the R of the antenna 39, and a triangular gap 40 is formed. Therefore, microwave radiation from the gap 40 increases, and the microwave radiation direction is changed. Will be.
[0106]
The antenna 39 has a distribution adjustment hole 41.
[0107]
As a result, it is possible to radiate microwaves from the hole 41, and there is an effect of changing the radiation direction of the microwaves.
[0108]
(Example 5)
FIG. 8 is a configuration diagram showing only the opening and the antenna of the high-frequency heating device according to the fifth embodiment of the present invention. The plurality of openings 42a and 42b and the antenna 43 complicate the shape of the gap generated between them, so that the microwave radiation direction is also complicated.
[0109]
(Example 6)
9 and 10 are configuration diagrams of a high-frequency heating device according to Embodiment 6 of the present invention. FIG. 9 is a block diagram showing only the antenna and the antenna holder that supports the antenna, and FIG. 10 is a block diagram showing only the distribution adjusting chamber and the waveguide.
[0110]
The outer shape of the antenna 44 is substantially circular, and has a partially expanded portion 45 and a cut 46. The three holes 47 are not for adjusting the distribution, but are holes for catching the three claws A49 of the antenna holder 48, and have a small shape (10 mm × 3.5 mm) so that the microwave does not easily pass. The hole 50 is a hole for inserting the positioning pin 51 of the antenna holder 48, and the stopper 52 is a protrusion on the antenna holder 48.
[0111]
Thus, in order to mount the antenna 44 to the antenna holder 48, first, the hole 50 is inserted into the pin 51, the claw A49 is inserted into the hole 47, the antenna 44 is rotated counterclockwise, and the notch 46 is cut by the stopper 52. Just hold it down.
The claw B53 is for fixing the antenna holder 48 to the distribution adjusting chamber 54, and is configured to fit into a hole 56 provided outside the waveguide 55 on the upper surface of the distribution adjusting chamber 54.
[0112]
In addition, the notch 57 in the antenna holder 48 is likely to concentrate the electric field on the spire 58 of the antenna 44, thereby allowing the material to escape to avoid locally generating high frequency dielectric losses in nearby antenna holders. This is the configuration.
[0113]
Incidentally, it is desirable that the antenna holder 48 of the present embodiment is made of a material such as PPS that is easy to process, has strength, and has low high-frequency dielectric loss. Of course, mica may be used if there is no problem in strength.
[0114]
Further, in this embodiment, the distribution adjusting chamber 54 is configured so that the heating chamber side is wider than the waveguide side in the vertical direction as well as the horizontal direction in FIG. There is an effect that makes it easier to make uniform.
[0115]
In addition, in the said Example, although it did not describe in particular about opening of the connection surface of a distribution adjustment chamber and a heating chamber, it is not limited only to full opening, It is also possible to block a part.
[0116]
Moreover, although the antenna has been described with only a flat plate, it is also conceivable to bend the edge, for example. Moreover, although the antenna and the distribution adjustment chamber have been described as being parallel to the heating chamber, the antenna and the distribution adjustment chamber may be inclined with respect to the ceiling wall surface, for example.
[0117]
Furthermore, it is conceivable to form antenna cuts and holes in a circular shape.
[0118]
【The invention's effect】
As described above, the present invention relates to a high-frequency heating apparatus that heats an object to be heated in a heating chamber with microwaves radiated from a magnetron, and the microwave is guided to the distribution adjusting chamber from the opening of the waveguide, and into the distribution adjusting chamber. It is configured to radiate uniformly from the periphery of the provided antenna into the heating chamber.
[0119]
As a result, the non-uniform microwave transmitted from the waveguide opening into the distribution adjustment chamber is partially blocked by the antenna and radiated from the end of the distribution adjustment chamber around the antenna to the heating chamber. Thus, the microwave radiation direction can be changed, and uniform microwaves can be radiated into the heating chamber.
[0120]
Therefore, it is possible to provide a high-frequency heating apparatus in which the heating distribution by microwaves is made uniform without being driven to rotate.
[Brief description of the drawings]
FIG. 1 is a cross-sectional configuration diagram of a high-frequency heating device according to a first embodiment of the present invention viewed from the front.
FIG. 2 is a sectional configuration view from the right
FIG. 3 is a structural view seen from above.
FIG. 4 is a block diagram showing only an aperture and an antenna.
FIG. 5 is a configuration diagram showing only an opening and an antenna of a high-frequency heating device according to a second embodiment of the present invention.
FIG. 6 is a configuration diagram showing only an opening and an antenna of a high-frequency heating device according to a third embodiment of the present invention.
FIG. 7 is a configuration diagram showing only an opening and an antenna of a high-frequency heating device according to a fourth embodiment of the present invention.
FIG. 8 is a configuration diagram showing only an opening and an antenna of a high-frequency heating device according to a fifth embodiment of the present invention.
FIG. 9 is a configuration diagram showing only an antenna of a high-frequency heating device and an antenna holder for supporting the antenna in Embodiment 6 of the present invention.
FIG. 10 is a block diagram showing only the distribution adjusting chamber and the waveguide.
FIG. 11 is a cross-sectional configuration diagram of a conventional rotating antenna of a microwave oven.
FIG. 12 is a configuration diagram of another conventional microwave oven.
[Explanation of symbols]
18, 54 Distribution adjustment room
19, 55 Waveguide
20, 32, 35, 38, 42a, 42b Opening
21, 33, 36, 39, 43, 44 Antenna
22 Heating chamber
24 Magnetron
28a, 28b cut
41 holes

Claims (20)

In a high-frequency heating apparatus that heats an object to be heated in a heating chamber with microwaves radiated from a magnetron, the microwave is guided from the opening of the waveguide to the distribution adjusting chamber and from the periphery of the antenna provided in the distribution adjusting chamber. A high-frequency heating device configured to radiate uniformly into the heating chamber. The high frequency heating apparatus according to claim 1, wherein the distribution adjusting chamber is arranged at a substantially central portion of at least one of the front and rear direction and the left and right direction of the top surface of the heating chamber. The high frequency heating device according to claim 1 or 2, wherein the outer shape of the opening and the antenna are different from each other. The high-frequency heating device according to claim 3, wherein the outer shape of the opening and the antenna have different vertices. The high-frequency heating device according to claim 3, wherein the outer shape of the opening and the antenna are different from each other. The high-frequency heating device according to claim 3, wherein microwaves are radiated from four corners by making the opening substantially rectangular and the outer shape of the antenna substantially circular. The high-frequency heating device according to any one of claims 3 to 6, wherein the opening and the outer shape of the antenna are approximately the same size. The high-frequency heating device according to claim 1 or 2, wherein an outer shape of the antenna is configured to be smaller than a wavelength λ of the microwave. The high-frequency heating device according to claim 8, wherein the outer shape of the antenna is approximately the same as the width of the waveguide. 3. The high frequency heating apparatus according to claim 1, wherein the antenna has a distribution adjusting hole or cut. The high-frequency heating device according to claim 10, wherein the hole or the notch has a shape elongated in the longitudinal direction of the distribution adjusting chamber. The high frequency heating apparatus according to claim 10, wherein the length of the hole or notch is set to about λ / 4 where λ is the wavelength of the microwave. The high-frequency heating device according to claim 10, wherein the hole or notch has a width of at least 5 mm. The high-frequency heating device according to claim 1 or 2, wherein the metal antenna is configured to be electrically insulated and fixed from the waveguide and the distribution adjusting chamber. The high-frequency heating device according to claim 14, wherein the metal antenna is configured not to be axially coupled in the waveguide. The high frequency heating apparatus according to claim 1 or 2, wherein the distribution adjusting chamber has a heating chamber side wider than the waveguide side. The high-frequency heating device according to claim 16, wherein the distribution adjusting chamber is configured to widen the heating chamber side along the microwave transmission direction of the waveguide. The high frequency heating apparatus according to claim 16, wherein the distribution adjusting chamber has a length equivalent to the wavelength λ of the microwave in at least one of the width direction of the waveguide and the microwave transmission direction. The high frequency heating apparatus according to claim 16, wherein the distribution adjusting chamber has a thickness that does not exceed λ / 4 where λ is a wavelength of the microwave. The high-frequency heating device according to claim 19, wherein the flat antenna is arranged at substantially the center in the thickness direction of the distribution adjusting chamber.

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