JP2015185409A - Microwave processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microwave processor capable of efficiently generating circular or ellipse polarization wave in a smaller space and shorter waveguide.SOLUTION: A heating chamber 1 is formed with a propagation part 3a (first propagation part) for propagating microwave toward the wall surface of a heating chamber in the wall surface thereof and is provided with a waveguide 3 including a propagation part 3b (second propagation part) for allowing microwave to propagate along the wall surface of the heating chamber. A circular polarization wave is generated at a pair of openings of an opening 4a and the other opening 4b which are disposed to include a range where a cross section of a propagation part 3a in which the microwave propagates toward the wall surface of heating chamber is projected to the wall surface of the heating chamber.

Description

  The present invention relates to a microwave processing apparatus such as a microwave oven that radiates microwaves to an object to be heated.

  Conventionally, in this type of microwave processing apparatus, microwaves generated by a magnetron, which is a typical microwave generation means, are propagated through a waveguide to be fed to a heating chamber, and are used for the food placed inside the heating chamber. Such an object to be heated is heat-treated. However, the electric field distribution in the heating chamber is not necessarily uniform. Therefore, in order to uniformly heat the object to be heated, some drive unit such as a structure that rotates the shelf on which the object to be heated is rotated to rotate the object to be heated itself or a structure that rotates an antenna that radiates microwaves. Generally, a method of stirring the microwave radiated to the object to be heated is used.

  On the other hand, a method has been proposed in which an object to be heated is uniformly heated by using circularly polarized waves or elliptically polarized waves whose electric field polarization plane rotates with time. In order to generate circularly polarized waves or elliptically polarized waves, it is necessary to provide a pair of excitation means whose excitation directions intersect and a phase difference between the pair of excitation phases.

  The excitation direction that can be supplied from the waveguide differs depending on the surface that constitutes the waveguide. In general, the rectangular waveguide type waveguide 100 has a rectangular cross section perpendicular to the traveling direction of the microwave, has a relatively large width dimension, and a pair of opposing wall surfaces (wide). And a pair of opposing wall surfaces with narrow width (referred to as narrow wall surfaces).

  As shown in FIG. 6, when an opening is provided in a cross-section 101 perpendicular to the microwave propagation direction in a rectangular waveguide type waveguide 100 in which microwaves propagate in the TE10 mode, Since excitation is caused by the electric field 104 in such a direction, the excitation is uniaxial. When the opening is provided in the narrow wall surface 102, the wall surface is excited in the direction of the uniform current 105, and thus the excitation is performed in one axis direction. When an opening is provided in the wide wall surface 103, excitation can be performed in the direction of the current 105 in all directions on the same plane depending on the location, so that biaxial excitation is possible.

  For these reasons, the wide wall surface 103 is provided with an opening used for generating circularly polarized waves that require a pair of excitation means whose excitation directions intersect.

  Further, since the excitation position shifts with time due to radio wave propagation, for example, circularly polarized waves can be generated by combining the two openings and arranging them appropriately.

  Patent Document 1 describes a method of disposing two rectangular slot-shaped openings 107 that are orthogonal to each other on the wide wall surface 103 of the waveguide 106 while facing each other, as shown in FIG. ing.

Japanese Patent No. 3510523

  However, as described in Patent Document 1, the conventional microwave processing apparatus in which a pair of circularly polarized apertures is provided on the wide surface 103 avoids the influence of disturbance of the electromagnetic field distribution in the vicinity of the magnetron. There has been a problem that the length of the waveguide becomes long. In addition, since an opening is provided in the wall surface parallel to the microwave propagation direction and the radiation is radiated in a direction perpendicular to the microwave propagation direction, there is a problem that efficiency is low.

  The present invention solves the above-described problems, and an object thereof is to provide a microwave processing apparatus capable of generating circularly or elliptically polarized waves with high efficiency by using a space-saving and short waveguide.

  In order to solve the above-described conventional problems, a microwave processing apparatus according to the present invention includes a heating chamber that houses an object to be heated, a microwave generation unit that generates a microwave, and a microwave generated by the microwave generation unit. A waveguide that propagates, and a plurality of openings that radiate microwaves from the waveguide to the heating chamber. The waveguide extends along the heating chamber wall surface and a portion that propagates the microwave toward the heating chamber wall surface. It consists of a part that propagates microwaves, and is configured to generate circularly polarized waves with a pair of openings. One of the pair of openings heats the cross section of the part that propagates microwaves toward the heating chamber wall of the waveguide The arrangement includes a range projected on the room wall surface.

  With the above configuration, the opening that generates circularly polarized waves can be provided at a position facing the microwave propagation direction and at a position parallel to the microwave propagation direction. The opening facing the microwave propagation direction radiates the microwave propagating toward the heating chamber wall surface in substantially the same direction, so even if the waveguide is short, the electric field in the uniform direction in the waveguide Excited in a stable direction. The opening provided at a position parallel to the microwave propagation direction can avoid influences such as disturbance of the electromagnetic field distribution near the magnetron by the part that propagates the microwave toward the heating chamber wall surface. Even if the portion that propagates the microwave is shortened, it can be excited in the intended direction, and a pair of apertures can be combined to reliably generate circularly or elliptically polarized waves.

  The microwave processing apparatus of the present invention is affected by radiation from a portion that propagates microwaves toward the wall surface of the heating chamber and disturbance of electromagnetic field distribution near the magnetron in the portion that propagates microwaves toward the wall surface of the heating chamber. By combining the radiation from the portion that propagates the microwave along the wall surface of the heating chamber that avoids the above, even if the waveguide is shortened, it is possible to reliably generate circularly polarized waves or elliptically polarized waves.

  In addition, by providing an opening facing the microwave propagation direction of the part that propagates the microwave toward the heating chamber wall surface, the propagated microwave can be radiated in substantially the same direction, thereby improving efficiency. Can do.

  Furthermore, the waveguide installation part can be made compact by arranging the part that propagates the microwave toward the heating chamber wall surface and the part that propagates the microwave along the heating chamber wall surface in an L shape.

Plan sectional drawing of the microwave processing apparatus in Embodiment 1 of this invention 1 is an enlarged cross-sectional view of a vicinity of a waveguide of a microwave processing apparatus according to a first embodiment of the present invention. Enlarged view of the vicinity of the opening of the microwave processing apparatus according to Embodiment 1 of the present invention. Plan sectional drawing of the microwave processing apparatus in Embodiment 2 of this invention FIG. 7 is an enlarged cross-sectional view of the vicinity of the waveguide of the microwave processing apparatus according to Embodiment 3 of the present invention. Explanatory drawing of the current flowing through the wall surface of a waveguide in a conventional microwave processing apparatus Configuration diagram of a conventional microwave processing device that generates circularly polarized waves

  According to a first aspect of the present invention, there is provided a heating chamber for storing an object to be heated, a microwave generating means for generating a microwave, a waveguide for propagating a microwave generated by the microwave generating means, and a heating chamber from the waveguide. The waveguide has a plurality of openings that radiate microwaves to the heating chamber wall surface and a portion that propagates microwaves toward the heating chamber wall surface, and a pair of microwave propagation waves along the heating chamber wall surface. A configuration in which circularly polarized waves are generated at the opening, and one of the pair of openings includes an area in which a cross section of a portion that propagates microwaves toward the heating chamber wall surface of the waveguide is projected onto the heating chamber wall surface. By using a combination of a microwave propagation direction and an opening in a direction parallel to the microwave propagation, circular polarization or elliptic polarization can be generated even with a short waveguide.

  The second aspect of the invention is particularly the microwave processing apparatus of the first aspect of the invention, wherein at least the center of the other opening that generates circularly polarized waves by a pair of openings is directed toward the heating chamber wall surface of the waveguide. The cross section of the part that propagates the microwave is removed from the range projected on the wall surface of the heating chamber, and stable excitation is achieved even if the part of the waveguide that propagates the microwave is short along the wall surface of the heating chamber. Can be secured, and can generate circularly polarized waves or elliptically polarized waves.

  According to a third aspect of the present invention, in particular, the microwave processing apparatus according to the first aspect of the present invention is configured such that circularly polarized waves are radiated from the pair of openings to the heating chamber, and the excitation directions of the radiated microwaves are not parallel. Thus, excitation in two directions can be secured, and circularly polarized waves or elliptically polarized waves can be reliably generated.

  According to a fourth aspect of the invention, in particular, the microwave processing apparatus of the first aspect of the invention has a shape in which a cross section substantially parallel to the microwave propagation direction of the waveguide is bent in an L shape, and the microwave generating means is the waveguide It is configured to be provided in a part that propagates microwaves toward the wall surface of the heating chamber. By using a waveguide bent in an L shape, circular polarization or elliptic polarization can be obtained even in a short waveguide. Can be generated.

  According to a fifth aspect of the invention, in particular, the microwave processing apparatus according to the first aspect of the present invention includes a portion that propagates microwaves toward the heating chamber wall surface of the waveguide and a portion that propagates microwaves along the heating chamber wall surface. It is configured such that the wide surfaces coincide with each other, and can be circularly polarized or elliptically polarized even with a short waveguide.

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

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
1 to 3 are explanatory diagrams of the microwave processing apparatus according to Embodiment 1 of the present invention. 1 is a sectional view as seen from the front, FIG. 2 is an enlarged sectional view near the waveguide, and FIG. 3 is a front view as seen from the inside of the heating chamber.

In the figure, a microwave oven as a typical microwave processing apparatus includes a heating chamber 1 for storing an object to be heated, a magnetron 2 as a typical microwave generating means for generating microwaves, and radiation from the magnetron 2. A waveguide 3 that propagates the microwaves and openings 4 a and 4 b that radiate the microwaves in the waveguide 3 into the heating chamber 1 are provided.

  The waveguide 3 is a rectangular waveguide, and a propagation part 3 a (first propagation part) that propagates the microwave 6 a toward the heating chamber 1 and a propagation part 3 b that propagates the microwave 6 b along the heating chamber 1. It is comprised by (2nd propagation part), and the cross section of the advancing direction of the microwaves 6a and 6b is L-shaped.

  One of the openings 4 a that generate a circularly polarized wave includes a range in which a cross section of the propagation part 3 a that propagates the microwave toward the wall surface of the heating chamber 1 of the waveguide 3 is projected onto the wall surface of the heating chamber 1. The position is opposite to the microwave propagation direction. Since the microwave 6a propagating toward the wall surface of the heating chamber 1 is radiated in substantially the same direction, even when the waveguide 3 is short, the microwave 6a is stabilized by the electric field 5 in the uniform direction in the waveguide 3. Excited in the direction.

  Among the openings 4 a and 4 b that generate a pair of circularly polarized waves, one opening 4 b has a cross section of the propagation portion 3 a through which the microwave 6 a propagates toward the wall surface of the heating chamber 1 of the waveguide 3. Is removed from the range projected on the wall surface of the heating chamber 1, and is disposed in the propagation portion 3 b that propagates the microwave 6 b along the heating chamber 1.

  As described above, since the propagation part 3a that propagates the microwave toward the wall surface of the heating chamber 1 can avoid the influence of disturbance of the electromagnetic field distribution near the magnetron 2, the microwave along the wall surface of the heating chamber 1 can be avoided. Even if the propagation part 3b for propagating the light is shortened, the opening 4b can be excited in the intended direction, and therefore the circularly polarized wave or the elliptically polarized wave can be reliably generated by the pair of openings 4a and 4b.

(Embodiment 2)
FIG. 4 is a front sectional view of the microwave processing apparatus according to the second embodiment of the present invention.

  In the figure, the waveguide 3 is coupled so as to cover the corner of the heating chamber projection 7 provided at the bottom of the heating chamber 1. The waveguide 3 includes a propagation part 3c (first propagation part) that propagates the microwave 6a toward the heating chamber 1, and a propagation part 3d (second propagation part) that propagates the microwave 6b along the heating chamber 1. Are arranged in front and rear.

  On the vertical wall surface side of the heating chamber projection 7, an opening 4 a that is long in the depth direction of the paper is provided facing the microwave 6 a propagating toward the heating chamber 1, and the propagating microwave 6 a is radiated with high efficiency as it is. To do. On the horizontal wall surface side of the heating chamber projection 7, an opening 4 b that is parallel to the microwave 6 b that propagates along the heating chamber 1 and that is long in the depth direction of the drawing is provided. Or elliptically polarized waves are generated.

(Embodiment 3)
FIG. 5 is an enlarged cross-sectional view of the vicinity of the microwave processing device waveguide according to the third embodiment of the present invention.

  In the figure, a magnetron 2 is attached to a waveguide 3 provided on one wall surface of a heating chamber 1, and microwaves 6a and 6b are propagated and radiated from openings 4a and 4b. The waveguide 3 includes a propagation part 3e (first propagation part) that propagates the microwave 6a toward the heating chamber 1 by the waveguide convex part 8, and a propagation part that propagates the microwave 6b along the heating chamber 1. And 3f (second propagation part).

Of the pair of openings that generate circularly polarized waves, one opening 4a faces the propagation direction of the microwave 6a of the propagation part 3e that propagates the microwave 6a toward the wall surface of the heating chamber 1 of the waveguide 3. Installed. Since the microwave 6a propagating toward the wall surface of the heating chamber 1 is radiated in substantially the same direction, even if the waveguide 3 is short, it is stabilized by the electric field 5 in the uniform direction in the waveguide 3. Excited in the direction.

  Of the openings that generate a pair of circularly polarized waves, the other opening 4 b is disposed in the propagation portion 3 f that propagates the microwave 6 b along the heating chamber 1. The portion 3e that propagates the microwave toward the wall surface of the heating chamber 1 is installed obliquely and has a long length even in a small space, so that the influence of disturbance of the electromagnetic field distribution in the vicinity of the magnetron 2 is avoided. Thus, the opening 4b can be excited in the intended direction, and the pair of openings 4a and 4b can surely generate circularly polarized waves or elliptically polarized waves.

  In addition, although the circularly polarized wave feeding means of the present embodiment has been illustrated by taking an I-shaped circularly polarized aperture separately disposed on the waveguide 3, it is not limited thereto. It is sufficient if there are two rectangular slots on the waveguide 3 that are orthogonal to each other, and may be L-shaped or partially crossed. Also, the two slots need not be orthogonal.

  Moreover, although it is a rectangular slot, it is not limited to a rectangle. It would be possible to generate circularly polarized waves even if the corners of the openings are rounded or elliptical. The basic idea of circularly polarized aperture is to combine two long and narrow shapes that are long in one direction and short in the perpendicular direction.

  As described above, since the microwave processing apparatus of the present invention can uniformly irradiate the object to be heated with microwaves, the microwave processing apparatus is effectively used for a microwave processing apparatus that performs food processing and sterilization. be able to.

1 Heating chamber 2 Magnetron (microwave generation means)
3 Waveguide 3a, 3c, 3e Propagation part (first propagation part)
3b, 3d, 3f Propagation unit (second propagation unit)
4a, 4b Opening 5 Electric field 6a, 6b Microwave 7 Heating chamber convex part 8 Waveguide convex part

Claims (5)

A heating chamber for storing an object to be heated, a microwave generating means for generating a microwave, a waveguide for propagating the microwave generated by the microwave generating means to the heating chamber, and the heating from the waveguide With multiple openings to radiate microwaves into the chamber,
The waveguide has a first propagation part that propagates microwaves toward the heating chamber wall surface, and a second propagation part that propagates microwaves along the heating chamber wall surface,
The opening is configured to generate circular polarization with a pair of openings,
One of the openings that generate circularly polarized waves by the pair of openings is a microwave processing apparatus that includes a range in which a cross section perpendicular to the tube axis of the first propagation part is projected onto the wall surface of the heating chamber. Among the openings that generate circularly polarized waves by the pair of openings, at least the center of the opening is a cross section of a portion that propagates microwaves toward the heating chamber wall surface of the waveguide. The microwave processing apparatus according to claim 1, wherein the microwave processing apparatus is disposed outside the projected range. The microwave processing apparatus according to claim 1, wherein the microwave excitation direction radiated from the openings that radiate circularly polarized waves to the heating chamber through the pair of openings is not parallel. A cross section substantially parallel to the microwave propagation direction of the waveguide is bent in an L shape,
The microwave processing apparatus according to claim 1, wherein the microwave generation means is provided in a portion of the waveguide that propagates microwaves toward the wall surface of the heating chamber. 2. A structure in which a portion of the waveguide that propagates microwaves toward the heating chamber wall surface and a portion that propagates microwaves along the heating chamber wall surface are stacked and integrated so that the wide surfaces coincide with each other. 2. The microwave processing apparatus according to 1.

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