JP4345374B2 - High frequency heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a method for fixing a fixed antenna of a high-frequency heating apparatus that heats an object to be heated by microwave heating.
[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 structure (turn table) in which a mounting table on which an object to be heated is placed is rotated, and a microwave is produced by rotating an antenna 3 that is coaxially coupled with a metal shaft portion 2 projecting into a waveguide 1 as shown in FIG. For example, a structure for changing the radiation direction (rotating antenna), a structure for stirring microwaves by rotating metal blades in a heating chamber (rotating stirrer), and the like.
[0003]
  Further, as shown in FIG. 9, the effect of irregular reflection by attaching metal pieces 7 a and 7 b through the mica 7 in the vicinity of the radiation antenna 6 of the magnetron 5 in the waveguide 4 and the effect by the rotation of the turntable 8 are achieved. There are some which are made more uniform by combining them (for example, see 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, the heating will proceed. 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]
  As described above, in particular, there is a desire to somehow equalize microwaves radiated from the ceiling wall by using components that do not rotate (especially inexpensive fixed antennas made of metal), and various studies have been conducted. However, it is considered that a constant electric field distribution always occurs on the metal that is not rotated and is maintained. Therefore, a metal fixed antenna always has a portion where the electric field is always strong locally, and how to secure the safety of that portion is an important issue.
[0009]
  The present invention solves this problem, and an object of the present invention is to improve the safety of a high-frequency heating apparatus in which a heating distribution by microwaves is made uniform using a metal fixed antenna.
[0010]
[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 in which microwaves radiated from a magnetron are guided from a waveguide opening to a distribution adjusting chamber to heat an object to be heated in the heating chamber. The distribution adjustment chamberBeforePlaced opposite the openingFlat plate processed into a circular shapeA metal antenna and the antennaIn the distribution adjustment chamberHolding means made of an insulating material to be fixed, and the holding meansIn order to avoid local high-frequency dielectric loss, the material of the holding means was formed avoiding a strong electric field position.And has an escape portion,The escape portion isIn the holding means in the vicinity of the antenna end face, where the electric field is highly likely to concentrate in the antennaWhen viewed from the antenna end face, the radial dimension of the central part of the antenna is 1 mm to 3 mm, and the radial dimension of the part opposite to the central side of the antenna is 5 mm or more.is doing.
[0011]
  Thereby, since the metal antenna is outside the waveguide, the electric field applied to the metal antenna can be weakened to some extent by the diffusion of the microwave, and the metal antenna is fixed with an insulator, so that the metal antenna And other metals (waveguide wall surface, distribution adjusting chamber wall surface, heating chamber wall surface) can be improved in insulation performance. Therefore, it is possible to improve the safety of the high-frequency heating device in which the heating distribution by the microwave is made uniform using the metal fixed antenna.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
  2. The high frequency heating apparatus according to claim 1, wherein the microwave radiated from the magnetron is guided from the opening of the waveguide to the distribution adjustment chamber and heats an object to be heated in the heating chamber.BeforePlaced opposite the openingFlat plate processed into a circular shapeA metal antenna and the antennaIn the distribution adjustment chamberHolding means made of an insulating material to be fixed, and the holding meansIn order to avoid local high-frequency dielectric loss, the material of the holding means was formed avoiding a strong electric field position.And has an escape portion,The escape portion isIn the holding means in the vicinity of the antenna end face, where the electric field is highly likely to concentrate in the antennaWhen viewed from the antenna end face, the radial dimension of the central part of the antenna is 1 mm to 3 mm, and the radial dimension of the part opposite to the central side of the antenna is 5 mm or more.is doing.
[0013]
  Thereby, since the metal antenna is outside the waveguide, the electric field applied to the metal antenna can be weakened to some extent by the diffusion of the microwave, and the metal antenna is fixed with an insulator, so that the metal antenna And other metals (waveguide wall surface, distribution adjusting chamber wall surface, heating chamber wall surface) can be improved in insulation performance. Therefore, it is possible to improve the safety of the high-frequency heating device in which the heating distribution by the microwave is made uniform using the metal fixed antenna.
[0014]
  AlsoThe escape portion can reduce the high-frequency dielectric loss of the holding means in the vicinity of the end face of the antenna, where the electric field tends to be strong, and can prevent the holding means from generating heat and melting.
[0016]
  AlsoThe main electric field that is directed toward the outside of the antenna from the end face of the antenna toward the wall of the distribution adjusting chamber or the waveguide can be effectively avoided.
[0017]
  Claim2In the described high-frequency heating device, the escape portion is constituted by a punched hole.
[0018]
  Claim3In the described high-frequency heating device, the escape portion is configured by a step.
[0019]
  As a result, the escape portion can be easily realized.
[0020]
【Example】
  Embodiments of the present invention will be described below with reference to the drawings.
[0021]
  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. 4A and 4B are configuration diagrams of the antenna and the holding means, in particular, FIG. 4A is a view from above, and FIG. 4B is a cross-sectional view taken along line AA in FIG.
[0022]
  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.
[0023]
  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.
[0024]
  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. 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. 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 in the cabinet is reduced to about 145 mm to improve efficiency. (By the way, the inner width is 285 mm, the depth is 270 mm) And, for example, a toast (not shown) is placed on the top 26 mounted in the chamber and can be efficiently baked from both the upper and lower sides. Even with a commercial power supply (100V, 15A), the toast baking time can be shortened 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.
[0025]
  As shown in FIG. 4, the antenna 21 has a flat plate shape whose outer shape is processed into a circular shape having a diameter of 80 mm, and has distribution adjustment 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.
[0026]
  On the other hand, the waveguide 19 is disposed in the center of the distribution adjusting chamber 18 in the depth direction (vertical direction in FIG. 3) 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.
[0027]
  Also, the length of the distribution adjusting chamber 18 in the left-right direction in FIG. 3 is such that the upper surface is about 103 mm and the lower surface is 143 mm and becomes wider toward the heating chamber. Further, 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 substantially the center in the thickness direction.
[0028]
  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.
[0029]
  Further, since the antenna 21 is located in the vicinity of the microwave radiated from the waveguide 19 through the opening 20, it can 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.
[0030]
  Further, the antenna 21 is not axially coupled in the waveguide 19. This allows the figure8The structure of the general rotating antenna 3 shown in FIG. 1 is a structure in which strong coaxial coupling is performed by the hole 31 provided on the metal shaft 2 and the metal wall surface 30, and microwaves are extracted and radiated from the tip 32. to differ greatly. Figure8In this embodiment, the directivity is determined by the shape of the tip 32 itself, but in this embodiment, the microwave radiation direction is changed not by the shape of the antenna 21 itself but by the relationship between the antenna 21 and the aperture or the distribution adjustment chamber. As a result, the directivity due to the shape of the antenna 21 itself can be eliminated, so that it is difficult to be non-uniform.
[0031]
  Further, the antenna 21 is mounted by a holding means made of a material having a low high-frequency dielectric loss such as PPS or mica, while being electrically insulated from the waveguide 19 and the distribution adjustment chamber 18, the distribution adjustment chamber 18 and the waveguide 19. It is conceivable to fix it to any one of the ceiling wall surface 15 and the like.
[0032]
  The holding means for holding the antenna of the present embodiment (hereinafter referred to as an antenna holder) will be described below.
[0033]
  The three holes 33 of the antenna 21 are not for adjusting the distribution, but are holes for catching the three claws A35 of the antenna holder 34, and have a small shape (10 mm × 3.5 mm) so that the microwave does not easily pass through. Yes. A hole 36 of the antenna 21 is a hole for inserting a positioning pin 37 of the antenna holder 34, and a hole 38 fits a stopper 39 formed of a protrusion of the antenna holder 34.
[0034]
  Thus, in order to mount the antenna 21 to the antenna holder 34, first, the pin 37 is inserted into the hole 36, the claw A35 is inserted into the hole 33, the antenna 21 is rotated counterclockwise, and the stopper 39 is inserted into the hole 38. Fit it in.
[0035]
  The claw B40 is for fixing the antenna holder 34 to the distribution adjusting chamber 18, and is configured to be fitted into a hole 41 provided on the outer surface of the waveguide 19 on the upper surface of the distribution adjusting chamber 18.
[0036]
  Further, since the hole 42 and the notch 43 of the antenna holder 34 are highly likely to concentrate the electric field on the end faces 44 and 45 of the antenna 21, in order to avoid locally generating high-frequency dielectric loss in the nearby antenna holder. The relief part which made the material escape is formed.
[0037]
  Incidentally, it is desirable that the antenna holder 34 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.
[0038]
  As described above, in this embodiment, the metal antenna 21 disposed not in the waveguide 19 but in the distribution adjusting chamber 18 so as to face the opening 20 is fixed by the antenna holder 34 made of an insulator. . In this respect, it is greatly different from the conventional configurations of FIGS. Conventionally, the metal shaft portion 2 of FIG. 8 and the metal pieces 7a and 7b of FIG. 9 are disposed inside the waveguide. Since this is a configuration having a rotating antenna and a turntable, the electric field distribution keeps changing due to the rotation of the rotating antenna and the turntable, even in the waveguide, so that the electric field concentration can be avoided to some extent. On the other hand, in this embodiment, there is nothing to rotate, and the electric field distribution is always constant, so it is necessary to devise the arrangement of the metal antenna 21, so that it faces the opening 20 in the distribution adjusting chamber 18 instead of the waveguide 19. An antenna 21 is arranged.
[0039]
  Thereby, since the antenna 21 is outside the waveguide 19, the microwave can diffuse in all directions in the distribution adjusting chamber 18, and the electric field applied to the antenna 21 can be weakened to some extent, and the antenna 21 can be insulated. Therefore, the insulation performance between the antenna 21 and other metals (the wall surface of the waveguide 19, the wall surface of the distribution adjusting chamber 18, and the ceiling wall surface 15 of the heating chamber 22) can be improved. Therefore, it is possible to improve the safety of the high-frequency heating device in which the heating distribution by the microwave is made uniform using the metal fixed antenna.
[0040]
  In addition, the distribution adjustment chamber 18 is arranged at a substantially central portion in the left-right direction of the top surface (ceiling wall surface 15) of the heating chamber 22.
[0041]
  As a result, microwaves are likely to be evenly diffused at least in the left-right direction of the top surface (ceiling wall surface 15) of the heating chamber 22, so that the electric field applied to the antenna 21 is also balanced in the left-right direction and is less likely to be concentrated locally. Therefore, insulation performance can be improved. Incidentally, since the balance is taken in the left-right direction, it is considered that the cuts 28a, 28b of the antenna 21 are configured in the left-right direction.
[0042]
  The antenna 21 is fixed to the waveguide 19 side of the antenna holder 34. This is a significant difference from the conventional configuration of FIG. Conventionally, the mica 7 that holds the metal pieces 7a and 7b is mounted in the waveguide 4. However, because this structure has the turntable 8, the electric field is generated by the rotation of the turntable regardless of the inside of the waveguide. As the distribution continued to change, electric field concentration on mica was avoided.
[0043]
  On the other hand, in this embodiment, there is nothing to rotate, and the electric field distribution is always constant, so that the arrangement of the antenna holder is also devised, and the antenna holder is placed on the opposite side (far side) from the waveguide as viewed from the antenna 21. It is arranged.
[0044]
  Accordingly, the antenna holder 34 is not exposed to a strong electric field generated between the antenna 21 and the wall surface of the waveguide 19, and the high frequency dielectric loss of the antenna holder 34 can be reduced. Heat generation and melting can be prevented.
[0045]
  Further, the antenna 21 is fixed by hooking the claw A35 of the antenna holder 34 into the hole 33 of the antenna 21.
[0046]
  Thereby, the antenna 21 can be easily fixed to the antenna holder 34.
[0047]
  Further, the antenna holder 34 is fixed to the wall surface of the distribution adjusting chamber 18.
[0048]
  As a result, the antenna holder 34 can be easily fixed, and the antenna holder 34 is not directly fixed to the waveguide 19, so that exposure to a strong electric field in the waveguide 19 can be prevented. . Therefore, the high frequency dielectric loss of the antenna holder 34 can be reduced, and accordingly, the antenna holder 34 can be prevented from being heated or melted.
[0049]
  Further, the tab B40 of the antenna holder 34 is hooked and fixed to the hole 41 on the wall surface of the distribution adjusting chamber 18.
[0050]
  Thereby, the antenna holder 34 can be easily fixed to the wall surface of the distribution adjusting chamber 18, and as a result, the antenna 21 can be easily fixed to the wall surface of the distribution adjusting chamber 18.
[0051]
  Further, the antenna holder 34 is configured to have a hole 42 and a notch 43 as an escape portion for releasing the material in a portion having a strong electric field.
[0052]
  Thereby, since the material of the antenna holder 34 does not exist in the relief portion, the high-frequency dielectric loss can be reduced as compared with the case where the material exists, and accordingly, the antenna holder 34 generates heat or melts. Can be prevented.
[0053]
  Further, a hole 42 and a notch 43 as escape portions are formed in the vicinity of the end faces 44 and 45 of the antenna.
[0054]
  As a result, the high frequency dielectric loss of the antenna holder 34 in the vicinity of the antenna end faces 44 and 45 where the electric field tends to be strong can be reduced, and accordingly, the antenna holder 34 can be prevented from being heated or melted. it can.
[0055]
  Further, the holes 42 and the cuts 43 serving as escape portions are configured such that the dimensions on the antenna outer side are larger than those on the antenna inner side when viewed from the antenna end faces 44 and 45. More specifically, the inner side is set to 1 mm to 3 mm and the outer side is set to 5 mm or more (of course, the larger the size, the higher the safety, but on the contrary, the strength becomes weaker. ).
[0056]
  Thereby, it is possible to more effectively avoid the strong electric field mainly directed toward the outside of the antenna from the end faces 44 and 45 of the antenna toward the wall surface of the distribution adjusting chamber 18 and the wall surface of the waveguide 19.
[0057]
  Further, the escape portion is constituted by a punched hole such as a hole 42 and a notch 43.
[0058]
  Thereby, an escape part is easily realizable.
[0059]
  (Example 2)
  FIG. 5 is a configuration diagram of an antenna 46 and an antenna holder 47 as a holding means in the configuration of the second embodiment of the present invention. 5A is a view from above, FIG. 5B is a cross-sectional view taken along the line BB in FIG. 5A, and FIG. 5B also shows the distribution adjusting chamber 48 and the waveguide 49. It is shown.
[0060]
  In this embodiment, the distribution adjustment chamber 48 is formed by squeezing the ceiling wall surface 50, and the antenna holder 47 made of mica is inserted into the bag portion 51 of the ceiling wall surface 50 and fixed with screws 52. The antenna 46 has a stepped portion 53 and is integrated with the antenna holder 47 by a pin 54. At this time, a step 55 as an escape portion can be formed between the end face around the antenna 46 and the antenna holder 47.
[0061]
  As described above, in this embodiment, the antenna holder 47 is fixed to the ceiling wall surface 50 of the heating chamber.
[0062]
  As a result, the antenna holder 47 can be easily fixed, and the antenna holder 47 is not directly fixed to the waveguide 49, so that exposure to a strong electric field in the waveguide 49 can be prevented. . Therefore, the high frequency dielectric loss of the antenna holder 47 can be reduced, and accordingly, the antenna holder 47 can be prevented from being heated or melted.
[0063]
  In addition, the antenna holder 47 is fixed to the ceiling wall surface 50 of the heating chamber by screwing.
[0064]
  As a result, the antenna holder 47 can be easily fixed to the ceiling wall surface 50 of the heating chamber. As a result, the antenna 46 can be easily fixed to the ceiling wall surface 50 of the heating chamber.
[0065]
  Further, the antenna holder 47 is configured to have a step 55 as an escape portion for escaping the material at a portion having a strong electric field.
[0066]
  Thereby, since there is no material of the antenna holder 47 in the step 55, the high frequency dielectric loss of the antenna holder 47 can be reduced, and accordingly, the antenna holder 47 can be prevented from being heated or melted.
[0067]
  Furthermore, it is very easy to configure the escape portion by the step 55.
[0068]
  (Example 3)
  FIG. 6 is a configuration diagram of an antenna 56 and an antenna holder 57 as a holding means in the configuration of the third embodiment of the present invention. 6A is a view seen from above, and FIG. 6B is a cross-sectional view taken along the line C-C in FIG. 6A.
[0069]
  In this embodiment, the antenna 56 is fixed to the antenna holder 57 by hooking the tab 59 of the antenna 56 into the hole of the antenna holder 57 and bending it inward.
[0070]
  Thereby, the antenna 56 can be easily fixed to the antenna holder 57.
[0071]
  In addition, the claw 59 can be prevented from being exposed to a strong electric field by directing the claw 59 to the heating chamber side instead of the waveguide side. In general, since the electric field tends to concentrate on the edge, there is a possibility of electric field concentration due to a strong electric field if the claw 59 is on the waveguide side, but this can be prevented.
[0072]
  (Example 4)
  FIG. 7 is a configuration diagram of an antenna 60 and an antenna holder 61 as a holding means in the configuration of the fourth embodiment of the present invention. 7A is a view seen from above, and FIG. 7B is a cross-sectional view taken along the line DD of FIG. 7A.
[0073]
  The outer shape of the antenna 60 is substantially circular, and has a part 62 that is partially expanded and a notch 63. In addition, the notch 64 on the antenna holder 61 side has a high possibility that the electric field concentrates on the spire portion (end face) 65 of the antenna 60, thereby avoiding local generation of high-frequency dielectric loss in the nearby antenna holder 61. Therefore, it is the escape part that caused the material to escape. Similarly, the antenna holder 61 is provided with steps 68 and 69 at portions facing the end faces 66 and 67. It is configured as an escape portion for escaping the material at the site where the electric field is strong.
[0074]
  Thereby, the high frequency dielectric loss of the antenna holder 61 in each escape part 64,68,69 can be reduced, and it can prevent that the antenna holder 61 generates heat | fever and melt | dissolves in connection with it.
[0075]
  In addition, it is very easy to configure the escape portion with a step.
[0076]
【The invention's effect】
  As described above, the high-frequency heating device of the present invention 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 to the distribution adjusting chamber from the opening of the waveguide, and A metal antenna disposed opposite to the opening in the distribution adjustment chamber, and the antenna is fixed by holding means made of an insulator.
[0077]
  Thereby, since the metal antenna is outside the waveguide, the electric field applied to the metal antenna can be weakened to some extent by the diffusion of the microwave, and the metal antenna is fixed with an insulator, so that the metal antenna And other metals (waveguide wall surface, distribution adjusting chamber wall surface, heating chamber wall surface) can be improved in insulation performance. Therefore, it is possible to improve the safety of the high-frequency heating device in which the heating distribution by the microwave is made uniform using the metal fixed antenna.
[0078]
  In addition, it is possible to reduce the high-frequency dielectric loss of the holding means in the vicinity of the end face of the antenna, where the electric field tends to be strong, and it is possible to prevent the holding means from generating heat and melting.
[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] Same as above, cross-sectional configuration diagram
FIG. 3 is a cross-sectional configuration view from above.
FIG. 4A is a configuration diagram of the antenna and the holding unit viewed from above.
  (B) AA sectional view of FIG. 4 (a).
FIG. 5A is a structural view of an antenna and holding means of a high-frequency heating device according to a second embodiment of the present invention as viewed from above.
  (B) BB sectional view of FIG. 5 (a).
6A is a configuration diagram of an antenna and a holding unit of the high-frequency heating device according to Embodiment 3 of the present invention as viewed from above. FIG.
  (B) CC sectional view of FIG. 6 (a).
FIG. 7A is a configuration diagram of an antenna and a holding unit of a high-frequency heating device according to a fourth embodiment of the present invention as viewed from above.
  (B) The DD sectional view of Drawing 7 (a) same as the above
FIG. 8 is a cross-sectional configuration diagram of a conventional rotating antenna of a microwave oven
FIG. 9 is a cross-sectional configuration diagram of another conventional microwave oven.
[Explanation of symbols]
  18, 48 Distribution adjustment room
  19, 49 Waveguide
  20 opening
  21, 46, 56, 60 Antenna
  22 Heating chamber
  24 Magnetron
  34, 47, 57, 61 Antenna holder (holding means)
  35 Claw A
  40 claw B
  41 holes
  42 hole (flank)
  43, 64 cuts (relief part)
  44, 45, 65, 66, 67 End face
  52 screw
  55, 68, 69 Level difference (escape part)
  58 holes
  59 claw

Claims (3)

In the high frequency heating apparatus the microwave radiated from the magnetron to heat the object to be heated in the heating chamber is guided to the distribution control chamber from the opening of the waveguide, a circle which is located opposite the front Symbol opening into the distribution control chamber a flat metal antenna processed into Jo, and retaining means made of an insulating material for fixing the antenna to the distribution control chamber, to avoid Oite locally high frequency dielectric loss is generated in the holding means A relief portion formed by avoiding a strong electric field position of the material of the holding means ,
The escape portion is formed in the holding means in the vicinity of the antenna end face where the electric field is highly likely to concentrate in the antenna , and the radial dimension of the center side portion of the antenna as viewed from the antenna end face is 1 mm. A high-frequency heating apparatus in which the dimension in the radial direction of the portion on the side opposite to the center side of the antenna is 5 mm or more . The high-frequency heating device according to claim 1, wherein the escape portion is constituted by a punched hole . The high-frequency heating device according to claim 1, wherein the escape portion is configured by a step .

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