JP7378019B2 - Microwave processing equipment - Google Patents

Description

The present disclosure relates to a microwave processing device equipped with a heater.

FIG. 5 is a schematic diagram showing the configuration of a conventional microwave processing apparatus 100. FIG. 6 is a plan view showing the ceiling 105a of the heating chamber 105 in the conventional microwave processing apparatus 100. As shown in FIGS. 5 and 6, the microwave processing device 100 is provided with a radiation area 101 that emits microwaves and an installation area for the heater 102, which are separated.

The radiation region 101 is arranged so as to occupy most of the ceiling 105a. The heater 102 is arranged in a limited range on the ceiling 105a so as to be away from the radiation area 101 and surround the radiation area 101. A radiation section 104 such as a rotating antenna is arranged within the radiation region 101 . The oscillating section 103 generates microwaves and supplies them to the radiating section 104. With this configuration, microwaves are radiated throughout the heating chamber 105.

Some of these microwave processing devices place the heating element at a lower position than the rotating antenna, or stop the highly directional end of the rotating antenna at a higher position than the heating element. (For example, see Patent Document 1).

The microwave processing device described in Patent Document 1 attempts to achieve a targeted heating distribution by stopping a rotating antenna in a direction where the surrounding sheathed heaters are less likely to interfere and radiating microwaves.

JP2008-286457A

However, with the conventional configuration described above, it is difficult to heat objects of various shapes, types, and quantities housed in the heating chamber to a desired state.

That is, if a sufficient microwave radiation area is secured, the installation area of the heater is limited. In this case, sufficient heating performance by the heater cannot be obtained. On the other hand, securing a sufficient installation area for the heater limits the microwave radiation area. In this case, if the object to be heated is placed over a wide area, the heating efficiency will decrease or uneven heating will occur, making it impossible to obtain sufficient heating performance by microwaves.

In order to ensure the heating performance of the heater, it is desirable to use a small antenna and widen the installation area of the heater. In order to ensure heating performance with microwaves, it is desirable to have a wide radiation area where antennas and the like are placed so that microwaves can be radiated over a wide range. That is, in order to simultaneously ensure the heating performance of the heater and the heating performance of the microwave, it is necessary to solve contradictory problems.

The present disclosure provides a microwave processing device that can heat objects of various shapes, types, and amounts as desired by achieving both heating performance by a heater and heating performance by microwaves. purpose.

A microwave processing apparatus according to one aspect of the present disclosure includes a heating chamber that houses an object to be heated, an oscillation section that generates microwaves, a radiation section, and a heater. The heater is arranged in the heating chamber at a predetermined distance from the wall surface of the heating chamber so as to form a plane facing the wall surface of the heating chamber. The radiator is disposed within the heating chamber and radiates microwaves into the space between the heater and the wall so that the microwaves propagate through the space between the heater and the wall.

According to this aspect, the space between the plane formed by the heater and the wall surface of the heating chamber can be used as a waveguide. As a result, the installation area of the heater can be widened by using a small antenna, and the radiation area of microwaves can be expanded. As a result, the heating performance of the heater and the heating performance of the microwave can be made compatible, and the object to be heated can be heated as desired.

FIG. 1 is a schematic diagram showing the configuration of a microwave processing apparatus according to Embodiment 1 of the present disclosure. FIG. 2 is a plan view of the ceiling of the heating chamber in the microwave processing apparatus according to the first embodiment. FIG. 3 is a cross-sectional view of the microwave processing apparatus according to the first embodiment taken along line 4-4 shown in FIG. FIG. 4 is an enlarged view of the radiation section of the microwave processing device according to Embodiment 2 of the present disclosure. FIG. 5 is a schematic diagram showing the configuration of a conventional microwave processing device. FIG. 6 is a plan view of the ceiling of a heating chamber in a conventional microwave processing apparatus.

A microwave processing apparatus according to a first aspect of the present disclosure includes a heating chamber that houses an object to be heated, an oscillation section that generates microwaves, a radiation section, and a heater. The heater is arranged in the heating chamber at a predetermined distance from the wall surface of the heating chamber so as to form a plane facing the wall surface of the heating chamber. The radiation section is disposed within the heating chamber and radiates microwaves into the space between the heater and the wall surface so that the microwaves propagate through the space between the heater and the wall surface.

In the microwave processing device according to the second aspect of the present disclosure, in addition to the first aspect, the radiation section is a loop antenna having a loop plane perpendicular to the wall surface. The center of the loop plane is located in the space between the heater and the wall surface. The microwave radiated by the radiator propagates through an antenna projection space that includes the loop plane and extends perpendicularly to the loop plane.

In the microwave processing device according to a third aspect of the present disclosure, in addition to the second aspect, the distance between the wall surface and the portion of the radiation section farthest from the wall surface is the distance between the wall surface and the heater farthest from the wall surface. It is less than twice the distance from the part.

In the microwave processing device according to the fourth aspect of the present disclosure, in addition to the second aspect, the heater crosses the antenna projection space at multiple locations.

In the microwave processing device of the fifth aspect of the present disclosure, in addition to the second aspect, the antenna projection space extends from the loop plane in two directions perpendicular to the loop plane.

In the microwave processing apparatus according to the sixth aspect of the present disclosure, in addition to the second aspect, the heating chamber includes a holder that holds the heater. The holder is placed outside the antenna projection space.

In the microwave processing apparatus according to the seventh aspect of the present disclosure, in addition to the second aspect, the heating chamber has a drawer part that connects the heater and an external power source. The extraction part is arranged outside the antenna projection space.

In the microwave processing device according to the eighth aspect of the present disclosure, in addition to the second aspect, the radiation section is arranged between two opposing wall surfaces of the heating chamber.

In the microwave processing device according to the ninth aspect of the present disclosure, in addition to the second aspect, one end of the loop antenna is connected to the transmission section via a connection section provided on the wall surface of the heating chamber. The other end of the loop antenna is connected to the wall surface at a grounding point that is away from the connecting point by a distance within one quarter of the wavelength of the microwave.

In the microwave processing device according to the tenth aspect of the present disclosure, in addition to the second aspect, the radiation section has a loop side arranged parallel to the wall surface.

In the microwave processing device according to the eleventh aspect of the present disclosure, in addition to the second aspect, the radiation section includes a plurality of loop antennas. The antenna projection spaces of the plurality of loop antennas do not overlap within the heating chamber.

In the microwave processing apparatus according to the twelfth aspect of the present disclosure, in addition to the first aspect, the wall surface is the ceiling of the heating chamber.

Embodiments of the present disclosure will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic diagram showing the configuration of a microwave processing device 50 according to Embodiment 1 of the present disclosure. FIG. 2 is a plan view of the ceiling 1a of the heating chamber 1 in the microwave processing apparatus 50.

As shown in FIGS. 1 and 2, the microwave processing apparatus 50 includes a heating chamber 1 that accommodates an object to be heated 2, an oscillation section 3, an antenna 4, a heater 5, and a transmission line 6.

The oscillation unit 3 includes, for example, a semiconductor amplifier and generates microwaves. The transmission line 6 transmits the microwaves generated by the oscillation section 3 to the antenna 4 via a connection section 6a provided on the ceiling 1a. Antenna 4 radiates microwaves transmitted through transmission line 6 into heating chamber 1 . Heater 5 is a sheathed heater. The heater 5 is held by a holder 8 provided on the ceiling 1a and is disposed near the ceiling 1a. In this embodiment, the antenna 4 and the transmission line 6 correspond to a radiation section and a transmission section, respectively.

Antenna 4 is placed on the ceiling 1a. The antenna 4 has a loop antenna structure in which one end is connected to a transmission line connected to the oscillation section 3, and the other end is connected to the ceiling 1a and grounded. The loop plane 4a of the antenna 4 is perpendicular to the ceiling 1a.

The microwave generated by the oscillator 3 generates a high frequency current flowing through the antenna 4. As a result, a strong electromagnetic field excitation 9 is generated on the loop plane 4a of the antenna 4. The electromagnetic field excitation 9 propagates in the antenna projection space 7 extending along the straight line X. The straight line X is a straight line that passes through the center of the loop plane 4a and is perpendicular to the loop plane 4a.

The antenna projection space 7 includes a loop plane 4a, and a cross section perpendicular to the straight line X has the same shape and size as the loop plane 4a. In other words, the antenna projection space 7 is the locus of the loop plane 4a of the antenna 4 when the loop plane 4a is virtually moved along the straight line X.

The heater 5 is arranged annularly at an appropriate distance from the ceiling 1a so as to form a plane facing the ceiling 1a. The space between the ceiling 1a and the heater 5 allows the propagation direction of the electromagnetic field radiated by the antenna 4 to be aligned. Therefore, in this embodiment, this space is used as a microwave waveguide. More specifically, the antenna projection space 7 becomes a waveguide. Thereby, even if a small antenna 4 is used, the microwave can be propagated to the end of the antenna projection space 7 shown in FIG. 2, that is, to the end of the heating chamber 1.

The holder 8 is placed outside the antenna projection space 7. Thereby, in the antenna projection space 7 which is a waveguide, the holder 8 does not reflect or divide the microwave propagating through the waveguide. As a result, even with the small antenna 4, microwaves can be reliably and efficiently propagated throughout the waveguide.

FIG. 3 is a cross-sectional view of the microwave processing device 50 taken along line 4-4 shown in FIG. As shown in FIG. 3, the heater 5 is arranged at an appropriate distance from the wall surface of the heating chamber 1 (in this embodiment, the ceiling 1a) as described above. Thereby, the antenna projection space 7 becomes a waveguide as described above.

The heater 5 is arranged over a wide area below the antenna projection space 7. The heater 5 traverses the antenna projection space 7 with a plurality of heater transverse sections 15 . With this configuration, a part of the microwave propagating through the waveguide is branched toward the object to be heated 2 at the heater crossing portion 15, as shown by the arrow 10 in FIG. That is, by diffraction and scattering of the microwaves generated around the heater 5, a part of the microwaves can be separated toward the object to be heated 2. Thereby, the microwave propagates more uniformly throughout the waveguide in the heating chamber 1, and the object to be heated 2 can be heated efficiently.

As shown in FIG. 2, the heater 5 is connected to an external power source 20 via a drawer portion 19 provided on the wall surface of the heating chamber 1 (in this embodiment, the rear wall surface 1b (see FIG. 3)). The drawer portion 19 is arranged outside the antenna projection space 7. In this embodiment, no structure is provided near the end of the space between the plane formed by the heater 5 and the ceiling 1a to prevent the propagation of microwaves. Thereby, a waveguide is secured and microwaves can be propagated over a wide range.

In this embodiment, the two antennas 4 are arranged so that the loop plane 4a is along the straight line Y, which is the center line of the heating chamber 1 in the depth direction. That is, the two antennas 4 are arranged between two opposing walls of the heating chamber 1. In this embodiment, these two wall surfaces are the rear wall surface 1b of the heating chamber 1 and the inner wall surface of the door 21 that covers the front opening of the heating chamber 1 (see FIG. 3).

The electromagnetic field excitation 9 of the antenna 4 having the loop antenna structure propagates from the loop plane 4a along two directions (direction 9a and direction 9b) perpendicular to the loop plane 4a. According to this embodiment, microwaves can be propagated uniformly and over a wide range. As a result, the object to be heated 2 can be heated more uniformly.

The antenna projection spaces 7 of each of the two antennas 4 do not overlap within the heating chamber 1. According to this embodiment, by preventing the microwaves radiated from the two antennas 4 from interfering with each other, the microwaves can be propagated to every corner of the heating chamber 1.

(Embodiment 2)
FIG. 4 is an enlarged view of the upper part of the heating chamber 1 in the microwave processing apparatus 50 according to Embodiment 2 of the present disclosure.

As shown in FIG. 4, in the present embodiment, an antenna 4 having a loop antenna structure has an antenna center portion 14, which is the center portion of the loop, between the plane formed by the heater 5 and the ceiling 1a of the heating chamber 1. It is constructed to be located in the space between. With this configuration, most of the microwaves radiated from the antenna 4 can be efficiently propagated into the space between the plane formed by the heater 5 and the ceiling 1a.

In this embodiment, the distance between the antenna 4 and the ceiling 1a is set to be less than twice the distance between the heater 5 and the ceiling 1a. More precisely, the distance 16 between the ceiling 1a and the part of the antenna 4 furthest from the ceiling 1a is set to be twice or less the distance 17 between the ceiling 1a and the part of the heater 5 furthest from the ceiling 1a.

Thereby, the antenna center portion 14 can be placed within the waveguide formed by the heater 5 and the ceiling 1a. As a result, most of the microwaves excited by the antenna 4 can be guided to the waveguide, and efficient heating can be achieved.

Generally, in order to prevent the ceiling 1a from deforming due to thermal expansion or the like, the ceiling 1a is partially provided with unevenness or an inclined surface 11. Since the inclined surface 11 is a part that absorbs deformation and is unstable, in this embodiment, the antenna 4 is arranged on the flat part 12 of the ceiling 1a.

As shown in FIG. 4, a connecting portion 18a is provided on the ceiling 1a. In this embodiment, the coaxial line 18 is the transmission line 6. The coaxial line 18 is connected to the oscillation section 3 and transmits the microwave generated by the oscillation section 3 to the antenna 4 via the connection section 18a.

One end of the antenna 4 is connected to the coaxial line 18 at a connecting portion 18a. The other end of the antenna 4 is connected to the ceiling 1a through a grounding portion 13 and grounded. In this embodiment, the grounding portion 13 is provided at a distance within one-fourth of the wavelength of the microwave from the connecting portion 18a. The reason for this is shown below.

When the grounding portion 13 is placed apart from the connecting portion 18a, the antenna 4 does not remain in the space below the flat portion 12, but reaches the space below the inclined surface 11. In this case, the stability of the radiation performance of the antenna 4 is impaired. The high frequency current flowing from the antenna 4 to the ground portion 13 returns to the outer sheath ground of the coaxial line 18 via the ceiling 1a. The electromagnetic field excitation caused by the high-frequency current flowing through the ceiling 1a shifts the intended radiation performance of the antenna 4.

However, in this embodiment, the distance between the connecting portion 18a and the grounding portion 13 is set to within one-fourth of the wavelength of the microwave. Thereby, the problem of stability and deviation of the radiation performance of the antenna 4 can be solved, and efficient heating can be achieved. This is because it is desirable that the distance between the connecting portion 18a through which the high-frequency current flows and the grounding portion 13 be short.

In this embodiment, the antenna 4 has a loop side 4b arranged substantially parallel to the inclined surface 11 of the heating chamber 1. In this way, when a high frequency current flows through the antenna 4 near the wall of the ceiling 1a, the electromagnetic field generated between the antenna 4 and the ceiling 1a affects the radiation performance of the antenna 4.

In this embodiment, by providing a space with a substantially uniform thickness between the antenna 4 and the ceiling 1a, it is possible to make the electromagnetic field distribution between the loop side 4b of the antenna 4 and the ceiling 1a more uniform. can. Thereby, the influence of the loop antenna on electromagnetic field excitation can be suppressed. As a result, good radiation performance of the antenna 4 can be obtained.

As described above, the microwave processing apparatus 50 according to the present embodiment uses the space between the heater 5 and the ceiling 1a of the heating chamber 1 as a waveguide. Thereby, the antenna 4 can radiate microwaves to the entire heating chamber 1. As a result, it is possible to achieve both heating performance using a heater and heating performance using microwaves using a small antenna.

The microwave processing device according to the present disclosure has been described using the above embodiments. However, the present disclosure is not limited thereto. For example, in this embodiment, the microwave oscillator is made of a semiconductor. However, other oscillators such as magnetrons may also be used. In this embodiment, the antenna is a loop antenna. However, antennas of other constructions may be used.

The present disclosure is applicable to heating devices that utilize dielectric heating, garbage disposal machines, and the like.

1, 105 Heating chamber 1a, 105a Ceiling 1b Rear wall 2 Object to be heated 3, 103 Oscillator 4 Antenna 5, 102 Heater 6 Transmission line 6a, 18a Connection part 7 Antenna projection space 8 Holder 9 Electromagnetic field excitation 9a, 9b Direction 10 Arrow 11 Inclined surface 12 Flat part 13 Ground part 14 Antenna center part 15 Heater crossing part 16, 17 Distance 18 Coaxial line 19 Outer part 20 External power supply 21 Door 50, 100 Microwave processing device 101 Radiation area 104 Radiation part

Claims (10)

a heating chamber configured to accommodate an object to be heated;
an oscillator configured to generate microwaves;
a heater arranged in the heating chamber at a predetermined distance from the wall surface so as to form a plane facing the wall surface of the heating chamber;
placed in the heating chamber and configured to radiate the microwave into the space between the heater and the wall so that the microwave propagates through the space between the heater and the wall. comprising a radiating section;
The radiation section is a loop antenna having a loop plane perpendicular to the wall surface, the loop antenna is located between two walls of the heating chamber facing the loop plane, and the center of the loop plane is The microwave is located in the space between the heater and the wall surface, and the microwave radiated by the radiator propagates in an antenna projection space that includes the loop plane and extends perpendicularly to the loop plane. Processing equipment. The microwave according to claim 1 , wherein a distance between the wall surface and a portion of the radiation section furthest from the wall surface is twice or less a distance between the wall surface and a portion of the heater furthest from the wall surface. Processing equipment. The microwave processing device according to claim 1 , wherein the heater crosses the antenna projection space at a plurality of locations. The microwave processing device according to claim 1 , wherein the antenna projection space extends from the loop plane in two directions perpendicular to the loop plane. The microwave processing apparatus according to claim 1 , wherein the heating chamber has a holder for holding the heater, and the holder is arranged outside the antenna projection space. The microwave processing apparatus according to claim 1 , wherein the heating chamber has a drawer part that connects the heater and an external power source, and the drawer part is arranged outside the antenna projection space. The transmission section further includes a transmission section connected to the oscillation section and configured to transmit the microwave to the radiation section, wherein one end of the loop antenna is connected to the transmission section via a connection section provided on the wall surface. 2. The microwave according to claim 1 , wherein the other end of the loop antenna is connected to the wall surface at a grounding portion spaced from the connecting portion by a distance within one quarter of the wavelength of the microwave. Processing equipment. The microwave processing device according to claim 1 , wherein the radiation section has a loop side arranged parallel to the wall surface. The microwave processing device according to claim 1 , wherein the radiation section includes a plurality of loop antennas, and the antenna projection spaces of the plurality of loop antennas do not overlap in the heating chamber. The microwave processing apparatus according to claim 1, wherein the wall surface is a ceiling of the heating chamber.

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