JP4992525B2 - Microwave processing equipment - Google Patents

Description

  The present invention relates to a microwave processing apparatus including a microwave generation unit configured using a semiconductor element.

  A conventional microwave processing apparatus of this type includes a heating chamber formed in a polyhedron having six or more planes, and a radiating antenna protruding from a part or all of each surface into the heating chamber (for example, Patent Documents). 1).

  And it is supposed that mutual interference can be prevented by arranging the mutual radiation antennas on different surfaces. Furthermore, since the radiating antennas are directed in different directions, the radiated radio wave propagates in all directions in the heating chamber and is reflected and scattered by the wall surface, so that the radio wave is uniformly distributed in the heating chamber.

  In addition, there is a type in which a plurality of microwave generators are distributed on the wall surface of the heating chamber, and the generators arranged on at least two wall surfaces among these generators are operated in a time-sharing manner (see, for example, Patent Document 2).

  Then, the microwave generation unit selected for operation is operated in a time-sharing manner to prevent the generation unit from being destroyed due to interference and to be operated simultaneously. In addition, the generators arranged on the orthogonal wall surfaces can be excited so as not to interfere with each other by appropriately selecting the coupling between the heating chamber and the generator, and can be simultaneously oscillated.

  Also provided with a phase shifter, a semiconductor oscillating unit, a distributing unit that divides the output of the oscillating unit into a plurality of components, a plurality of amplifying units that amplify the distributed outputs, and a combining unit that combines the outputs of the amplifying units And a phase shifter is provided between the distributing unit and the amplifying unit (see, for example, Patent Document 3).

  The phase shifter is configured to switch the microwave pass line length according to the on / off characteristics of the diode. In addition, the synthesis unit can use two 90-degree and 180-degree hybrids, so that the output of the synthesis unit can be made two. Can be in phase or out of phase.

In addition, this type of microwave processing apparatus generally uses a vacuum tube called a magnetron in a microwave generation section as represented by a microwave oven.
JP-A-52-193242 Japanese Patent Laid-Open No. 53-5445 JP 56-132793 A

  However, the configuration in which the radiation antenna is arranged on each surface of the conventional polyhedron is different in the radiation direction, but the scattering due to the reflection on the wall surface of the heating chamber and the scattered microwave hit the wall surface and further scatter. Therefore, it is impossible to prevent interference from microwaves radiated from other radiating antennas.

In addition, it is disclosed that when a plurality of microwave generators are arranged on the wall surface of the heating chamber and they are operated in a time-sharing manner, simultaneous oscillation is possible when arranged on the orthogonal wall surfaces. If it is a simple coupling form, there is no disclosure of whether or not mutual interference can be avoided, and only the possibility of realization.

  Further, in the case of a device equipped with a phase shifter, the microwaves radiated from the two outputs of the combining unit can change the radiated power ratio and phase difference from the two radiating antennas by changing the phase by the phase shifter. Although it is possible to change it instantaneously, it is difficult to heat objects to be heated in various shapes, types, and quantities stored in a heating chamber to which microwaves are supplied by radiation to a desired state. Was.

  The present invention solves the above-described conventional problems, and optimally arranges a plurality of power feeding portions having a function of radiating microwaves on a wall surface constituting a heating chamber, thereby allowing various shapes, types, and quantities. An object of the present invention is to provide a microwave generating apparatus that heats different objects to be heated to a desired state.

In order to solve the above-described conventional problems, the microwave processing device of the present invention includes an oscillation unit, a power distribution unit that distributes and outputs the output of the oscillation unit, and an output of the power distribution unit. A microwave generation unit having an amplification unit for amplifying, and a plurality of output units for outputting the outputs of the amplification unit, a heating chamber for storing an object to be heated, and the microwave generation unit in the heating chamber, respectively. A plurality of power feeding sections for supplying output, the plurality of power feeding sections covering the opening provided on the wall surface of the heating chamber and the opening from the outside of the wall surface of the heating chamber and having the opening as a terminal side. A feeding section configured to supply a microwave generated by the microwave generating section to the wave guide section, and an opening of the feeding section disposed on the opposing wall surface constituting the heating chamber in a plurality of feeding sections. placed in a parallel state, the heating chamber Are those comprising an opening of the feeding portion disposed adjacent walls consist disposed configured in an orthogonal state, the microwave radiated from the respective openings arranged on the opposite wall a direction parallel state of the opening Therefore, the polarization planes of the microwaves radiated from the openings are substantially the same, and the energy of each microwave can be concentrated on the object to be heated.

  In addition, by arranging the opening of the power feeding unit arranged on the adjacent wall surface in an orthogonal state, the plane of polarization of the microwave radiated from the opening of the adjacent power feeding unit can be made in an orthogonal state so that mutual interference can be reduced. The energy of the microwave radiated from each adjacent power feeding unit can be efficiently supplied to the object to be heated.

  In the microwave processing apparatus of the present invention, a plurality of power feeding parts having a function of radiating microwaves are optimally arranged on the wall surface constituting the heating chamber, and the radiation direction from each power feeding part is optimized. It is possible to provide a microwave processing apparatus that heats objects to be heated having different shapes, types, and amounts to a desired state.

The first invention includes an oscillating unit, a power distributing unit that distributes and outputs the output of the oscillating unit, an amplifying unit that amplifies the output of the power distributing unit, and an output of the amplifying unit, respectively. A microwave generation unit having a plurality of output units to output, a heating chamber that houses an object to be heated, and a plurality of power feeding units that supply the respective outputs of the microwave generation unit to the heating chamber, The plurality of power feeding units include an opening provided on the wall surface of the heating chamber, the waveguide covering the opening from the outside of the wall surface of the heating chamber and having the opening as a termination side, and the microwave generating unit on the waveguide unit. And a supply section for supplying the generated microwaves, and in the plurality of power supply sections, the openings of the power supply sections arranged on the opposing wall surfaces constituting the heating chamber are arranged in a parallel state, and adjacent to the heating chamber. wall
The microwaves radiated from the respective openings arranged on the opposing wall surface are perpendicular to the direction of the parallel state of the openings. Therefore, the polarization planes of the microwaves radiated from the openings are substantially parallel to each other, so that the energy of each microwave can be concentrated on the object to be heated.

In addition, it consists of a configuration in which the openings of the power feeding units arranged on the adjacent wall surfaces constituting the heating chamber are arranged in an orthogonal state, and thereby the polarization plane of the microwave radiated from the opening of the adjacent power feeding unit is in an orthogonal state Thus, mutual interference can be mitigated, and microwave energy radiated from each power feeding section can be efficiently supplied to the object to be heated.

According to a second aspect of the present invention, particularly in the plurality of power feeding portions of the first invention, the opening of the power feeding portion arranged on the side wall surface of the heating chamber is arranged at a position higher than the feeding portion to the waveguide portion. Therefore, the propagation direction of the microwave radiated from the opening can be biased toward the upper wall surface, and the deflection surface of the microwave radiated from each opening due to the influence of the amount and shape of the object to be heated The disturbance can be alleviated and the microwave energy can be supplied to the object to be heated more efficiently.

According to a third aspect of the present invention, in particular, in the plurality of power feeding units of the first invention, the opening of the power feeding unit disposed on the side wall surface of the heating chamber is configured to be disposed substantially at the center of each side wall surface. The disturbance of the deflection surface of the microwave radiated from each opening due to the bulky effect of the heated object can be alleviated, and the microwave energy can be supplied to the object to be heated more efficiently.

According to a fourth aspect of the invention, in particular, a phase variable unit is arranged in at least one of a plurality of transmission paths for transmitting the output of the power distribution unit of the first invention to the amplifier unit. By changing the phase of the microwaves radiated from one of the power supply units over time, the phase difference from the microwaves output from other power supply units is changed over time, and the microwave distribution in the heating chamber is changed. Uniform heating of the heated product can be further promoted.

In the fifth invention, in particular, in the plurality of power feeding units of the first invention, the phase difference of the microwave between the pair of power feeding units arranged on the opposing wall surfaces is made variable, and the phase difference is made variable. By making it, the heating of the specific part of a to-be-heated material can be accelerated | stimulated, and the whole to-be-heated material can be heated to a desired state.

In the sixth invention, in particular, in the plurality of power feeding units of the first invention, the phase difference of the microwave between the pair of power feeding units arranged on the adjacent wall surfaces is made variable, and the phase difference is made variable. By making it, the heating of the more specific part of the to-be-heated material can be accelerated | stimulated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of a microwave processing apparatus according to the first embodiment of the present invention.

In FIG. 1, a microwave generation unit 10 includes an oscillation unit 11 configured using a semiconductor element, three power distribution units 12 a, 12 b, 12 c, and a distribution unit 12 b, each of which has a two-stage configuration that distributes the output of the oscillation unit 11. Using the semiconductor elements that further amplify the respective outputs of the microwave transmission paths 14a to 14d and the first stage amplifying parts 13a to 13d that lead the respective outputs of 12c to the first stage amplifying parts 13a to 13d configured using the semiconductor elements of the subsequent stage Electric power inserted into the microwave transmission paths 17a to 17d and the microwave transmission paths 17a to 17d for guiding the outputs of the configured main amplification sections 15a to 15d and main amplification sections 15a to 15d to the output sections 16a to 16d of the microwave generation section 10 Detection unit 1
8a to 18d.

  In addition, the microwave processing apparatus of the present invention includes a heating chamber 19 having a substantially rectangular parallelepiped structure that accommodates an object to be heated, and the heating chamber 19 includes a left wall surface 20, a right wall surface 21, a bottom wall surface 22, and an upper surface made of a metal material. It is comprised from the wall surface 23, the back wall surface 24, and the opening-and-closing door (not shown) opened and closed in order to accommodate a to-be-heated material, and it is comprised so that the supplied microwave may be confined inside. Further, power supply units 25 a to 25 d that transmit the four outputs of the microwave generation unit 10 and radiate the microwaves into the heating chamber 19 are arranged on the respective wall surfaces constituting the heating chamber 19. The power feeding portions 25c and 25d are disposed in the approximate center of the left wall surface 20 and the right wall surface 21 of the opposing configuration, respectively, and the power feeding portions 25a and 25b are disposed in the approximate center of the upper wall surface 23 and the bottom wall surface 22, respectively.

  And each electric power feeding part 25a-25d covers the opening part 251a-251d provided in the heating chamber wall surface, the opening part 251a-251d from the exterior of a heating chamber wall surface, and arrange | positions each opening part 251a-251d in the termination | terminus side. The wave sections 252a to 252d and supply sections 253a to 253d for supplying the respective outputs of the microwave generation section 10 to the respective waveguide sections 252a to 252d. The openings 251a to 251d have a substantially rectangular shape, and the opposed openings 251a and 251b and the openings 251c and 251d are arranged so that the longitudinal opening directions of the substantially rectangular openings are parallel to each other. In addition, the openings 251c and 251d arranged on the left and right wall surfaces orthogonal to and adjacent to the upper wall surface 23 where the opening 251a is arranged are arranged so that the longitudinal direction of the openings is orthogonal. Furthermore, the power supply portions 25c and 25d disposed on the left and right wall surfaces 20 and 21 are arranged such that the openings 251c and 251d are higher in the height direction than the supply portions 253c and 253d of the respective power supply portions. In addition, in order to increase the transmission efficiency of the microwave into the heating chamber 19 as a component, an impedance matching element may be attached inside the waveguide portions 252a to 252d.

  The first stage amplifying units 13a to 13d and the main amplifying units 15a to 15d constitute a circuit with a conductor pattern formed on one surface of a dielectric substrate made of a low dielectric loss material, and are semiconductor elements that are amplifying elements of the amplifying units. Matching circuits are arranged on the input side and the output side of each semiconductor element in order to operate the semiconductor device satisfactorily.

  The microwave transmission paths 14a to 14d and 17a to 17d form a transmission circuit having a characteristic impedance of about 50Ω by a conductor pattern provided on one surface of a dielectric substrate.

  The power distribution units 12a, 12b, and 12c each have a 3 dB branch line coupler configuration having the same structure, and the configuration will be described as a representative of the power distribution unit 12a. Assuming that each terminal of the power distribution unit 12a is 121 to 124, the characteristic impedance is approximately 50Ω between the terminal 121 and the terminal 122 and between the terminal 123 and the terminal 124, and the electrical length is λ / 4 (λ is the frequency band used). A microstrip line having an effective wavelength of the center frequency of the microstrip line having a characteristic impedance of about 35.35Ω and an electrical length of λ / 4 between the terminal 121 and the terminal 123 and between the terminal 122 and the terminal 124. Further, a power terminator 125 having a resistance value of 50Ω is connected to the terminal 123. With this configuration, the microwave signal input to the terminal 121 is distributed to the terminal 122 and the terminal 124 and output. At this time, the signal output from the terminal 122 and the terminal 124 is delayed in phase by 90 degrees with respect to the phase of the output signal from the terminal 122.

  With the configuration in which the power distribution units are connected in two stages, the output power of the oscillating unit 11 is distributed approximately ¼ at a time and is output to the subsequent first stage amplification units 13a to 13d. When the microwave signal transmitted through the microwave transmission path 14b is used as a reference, the microwave signal transmitted through the microwave transmission paths 14a and 14c is transmitted as a signal whose phase is delayed by 90 degrees and transmitted through the microwave transmission path 14d. The microwave signal to be transmitted is transmitted as a signal whose phase is delayed by 180 degrees.

  Further, phase variable sections 26a and 26b are inserted in the microwave transmission paths 14a and 14c, respectively. The phase variable sections 26a and 26b are configured by using a variable capacitance element whose capacitance changes according to the applied voltage, and the phase variable range is a range from 0 degrees to about 180 degrees.

  The power detection units 18a to 18d extract so-called reflected wave power transmitted from the heating chamber 19 side to the microwave generation unit 10 side. The power coupling degree is about 40 dB, for example. Extract the electric energy of 1/10000. The power signals are rectified by a detection diode (not shown), smoothed by a capacitor (not shown), and the output signal is input to the control unit 27.

  The control unit 27 detects the heating conditions (arrow 28) obtained from the heating condition of the object to be heated (arrow 28) directly input by the user or the heating information (arrow 28) obtained from the heating state of the object to be heated and detection from the power detection units 18a to 18d. Based on the information, control of driving power supplied to the oscillation unit 11, the first stage amplification units 13a to 13d, and the main amplification units 15a to 15d, which are components of the microwave generation unit 10, and the phase variable units 26a and 26b are supplied. By controlling the voltage to be heated, the object to be heated housed in the heating chamber 19 is optimally heated.

  The microwave generator 10 is provided with a heat radiating means (not shown) for radiating heat generated by the semiconductor element. A placing plate 29 made of a low dielectric loss material that covers and feeds the power supply unit 25b provided on the bottom wall surface 22 of the heating chamber 19 is disposed.

  About the microwave processing apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, the object to be heated is stored in the heating chamber 19, the heating condition is input from the operation unit (not shown), and the heating start key is pressed. In response to the control output signal of the control unit 27 that has received the heating start signal, the microwave generation unit 10 starts operating. The control unit 27 operates a drive power supply (not shown) to supply power to the oscillation unit 11. At this time, the initial oscillation frequency of the oscillation unit 11 is supplied with a voltage signal set to 2450 MHz, for example, and oscillation starts.

  When the oscillating unit 11 is operated, its output is distributed approximately ½ by the power distributor 12a, and further approximately ½ distributed by the subsequent power distributors 12b and 12c, resulting in four microwave power signals. . Thereafter, the drive power supply is controlled to operate the first stage amplifier, and then the main amplifier is operated.

  And each microwave power signal is each output to the output parts 16a-16d through the amplifier parts 13a-13d and 15a-15d which operate | move in parallel, and the electric power detection parts 18a-18d. Each output is transmitted to the power feeding units 25 a to 25 d and radiated into the heating chamber 19. At this time, based on the phase of the microwave signal radiated from the power supply unit 25b, the microwave signals of the power supply unit 25a and the power supply unit 25c are delayed by approximately 90 degrees, and the microwave signal of the power supply unit 25d is approximately the same. The signal is delayed by 180 degrees. That is, it arrange | positions so that the output of the microwave generation part 10 may be supplied to each electric power feeding part so that the phase difference between adjacent electric power feeding parts may be about 90 degree | times. Each main amplifying unit at this time outputs microwave power of less than 100 W, for example, 50 W.

  When 100% of the microwave power supplied into the heating chamber 19 is absorbed by the object to be heated, the reflected power from the heating chamber 19 is eliminated, but the type, shape, and amount of the object to be heated include the object to be heated. Based on the output impedance of the microwave generation unit 10 and the impedance of the heating chamber 19, the reflected power transmitted from the heating chamber 19 side to the microwave generation unit 10 side is generated.

  The power combiners 18a to 18d are coupled with the reflected power transmitted to the microwave generation unit 10 and detect a signal proportional to the amount of reflected power. The control unit 27 receiving the detection signal Select the oscillation frequency that minimizes the power. For this frequency selection, the control unit 27 changes the oscillation frequency of the oscillation unit from the initial 2450 MHz to a lower frequency side with a 0.1 MHz pitch (for example, 1 MHz in 10 milliseconds), which is the lower limit of the frequency variable range. When 2400 MHz is reached, the frequency is increased at a 1 MHz pitch, and when 2450 MHz is reached, the frequency is increased again to 2500 MHz, which is the upper limit of the frequency variable range, at a 0.1 MHz pitch. A frequency at which the reflected power obtained in the frequency variation is minimized and a signal corresponding to the reflected power at that frequency are stored. Then, select the frequency with the smallest signal corresponding to the reflected power in the frequency group where the reflected power is minimized, and control the oscillation unit to oscillate the selected frequency and respond to the heating condition where the oscillation output is input So that the output can be obtained. Thereby, each main amplifying part outputs microwave power of 200 W to 300 W, respectively.

  Each output is transmitted to the power feeding units 25 a to 25 d and radiated into the heating chamber 19. At this time, based on the phase of the microwave signal radiated from the power supply unit 25b, the microwave signals of the power supply unit 25a and the power supply unit 25c are delayed by approximately 90 degrees, and the microwave signal of the power supply unit 25d is approximately the same. The signal is delayed by 180 degrees. That is, it arrange | positions so that the output of the microwave generation part 10 may be supplied to each electric power feeding part so that the phase difference between adjacent electric power feeding parts may be about 90 degree | times.

  In addition, by using a 90-degree hybrid distributor in the power distribution unit for forming a phase difference that is a multiple of about 90 degrees, a stable uniform distribution can be executed in a compact shape, and the power distribution units are connected in multiple stages. Thus, even if 4-distribution or 8-distribution is formed, the phase difference between the distribution outputs can be stably formed at approximately 90 degrees.

  Further, by controlling the voltage applied to the phase variable sections 26a and 26b inserted in the microwave transmission paths 14a and 14c, the positions of the opposing and / or adjacent power feeding sections 25a, 25b, 25c, and 25d, respectively. By making the phase difference the same phase or reversed phase (180 degree difference), the propagation state of the microwave in the heating chamber 19 is changed over time, the local heating of the heated object is eliminated, and the heating is made uniform. Can be promoted.

  In the present embodiment, only two phase variable sections are inserted. However, a plurality of phase variable sections are inserted into all the microwave transmission paths 14a to 14d at the maximum, and each is individually and temporally controlled. Uniform heating can be further promoted by changing the combination of the phases of the microwaves radiated from the power feeding unit. Further, by controlling the voltage applied to the phase variable unit based on the detection signals of the power detection units 18a to 18d so as to reduce the amount of reflected power, the heating efficiency can be increased and the heating can be performed for a short time. . When the amount of reflected power detected by the power detection unit exceeds a predetermined maximum allowable reflected power amount, the control unit 27 supplies the oscillation unit 11 or the amplification units 13a to 13d and 15a to 15d so as to reduce the oscillation output. Electric power is reduced to avoid thermal destruction of each semiconductor element.

  In the arrangement of the plurality of power feeding parts, at least two power feeding parts are heated by being arranged on adjacent wall surfaces (the left wall surface 20 and the bottom wall surface 22 or the relationship between the right wall surface 21 and the bottom wall surface 22) constituting the heating chamber. Heating a thick object to be heated can be promoted by directly irradiating the object with microwaves from two different directions.

In addition, the microwaves radiated from the openings of the power supply units provided on the opposing wall surfaces in the plurality of power supply unit arrangements propagate while circulating around the heating chamber wall surfaces in a direction perpendicular to the direction of the parallel state of the openings. Therefore, the polarization planes of the microwaves radiated from the openings are substantially parallel, and the energy of each microwave can be concentrated on the object to be heated.

  Further, in the plurality of power supply units, the power supply unit openings arranged on the adjacent wall surfaces constituting the heating chamber are arranged in an orthogonal state, whereby microwaves radiated from the adjacent power supply unit openings By making the planes of polarization of each other orthogonal, the mutual interference can be mitigated, and the microwave energy radiated from each power feeding section can be efficiently supplied to the object to be heated.

  Furthermore, the opening part of the power feeding part arranged on each of the left wall surface 20 and the right wall surface 21 which are the side wall surfaces of the heating chamber is configured to be arranged at a position higher than the supply part to the waveguide part. The propagation direction of the radiated microwave can be biased toward the upper wall surface, and the disturbance of the deflection surface of the microwave radiated from each opening due to the influence of the amount and shape of the object to be heated is mitigated. Wave energy can be supplied to the object to be heated more efficiently.

  Moreover, the opening part of the electric power feeding part arrange | positioned at the left wall surface 20 and the right wall surface 21 which are the side wall surfaces of a heating chamber respectively consists of a structure arrange | positioned in the approximate center of each side wall surface, and, thereby, the bulkiness of a to-be-heated material The disturbance of the deflection surface of the microwave radiated from each opening due to the influence of the above can be alleviated, and the microwave energy can be supplied to the object to be heated more efficiently.

  Furthermore, by arranging the phase variable unit in at least one of the plurality of transmission paths for transmitting the output of the power distribution unit to the amplifier unit, the phase of the microwave radiated from the target power supply unit by controlling the phase variable unit By changing the time with time, the phase difference from the microwaves output from other power supply units is changed with time, and the microwave distribution in the heating chamber is changed to further promote uniform heating of the object to be heated. be able to.

(Embodiment 2)
FIG. 2 is a block diagram of a microwave processing apparatus according to the second embodiment of the present invention.

  In FIG. 2, the same members or the same function members as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. The second embodiment is different from the first embodiment in that an amplification unit selection unit 30 is used.

  That is, in FIG. 2, the microwave generation unit 31 includes an oscillation unit 11 configured using a semiconductor element, a power distribution unit 12 a that distributes the output of the oscillation unit 11 into two, and outputs of the power distribution unit 12 a to the subsequent amplification unit selection. The microwave transmission paths 32a and 32b leading to the means 30a and 30b, the switching terminals 301a to 301d of the amplifying part selecting means 30a and 30b, and the input terminals of the first stage amplifying parts 13a to 13d configured using semiconductor elements are connected. The outputs of the main amplifiers 15a to 15d and the main amplifiers 15a to 15d configured by using semiconductor elements that further amplify the outputs of the microwave transmission paths 33a to 33d and the first stage amplifiers 13a to 13d are used as the microwave generator 31. Of microwave transmission paths 17a to 17d led to the output sections 16a to 16d of the It is composed of a part 18a~18d.

Moreover, it has the heating chamber 19 which consists of a substantially rectangular parallelepiped structure which accommodates to-be-heated material, and the heating chamber 19 is the left wall surface 20, the right wall surface 21, the bottom wall surface 22, the upper wall surface 23, the back wall surface 24, and to-be-heated which consist of metal materials. It consists of an open / close door (not shown) that opens and closes in order to store objects, and is configured to confine the supplied microwave inside. And the electric power feeding parts 25a-25d respectively connected to the four output parts of the microwave generation part 31 are arrange | positioned at each wall surface which comprises the heating chamber 19. FIG. Feeding portions 25c and 25d are arranged at approximately the center of the left wall surface 20 and the right wall surface 21 of the opposing configuration, respectively, and feeding portions 25a and 25b are disposed at approximately the centers of the upper wall surface 23 and the bottom wall surface 22, respectively. Then, the power feeding unit 25a and the power feeding unit 25d are switched and selected by the amplifier switching unit 30a. Further, the power feeding unit 25b and the power feeding unit 25c are switched and selected by the amplifier switching unit 30b.

  The output power of the oscillating unit 11 is distributed approximately ½ by the power distributing unit 12a, is transmitted through the microwave transmission paths 32a and 32b, and is input to the subsequent amplifying unit selecting means 30a and 30b. The amplifying unit selection means 30a and 30b select the amplifying unit that transmits the microwave among the following amplifying units 13a to 13d (and 15a to 15d). Then, by controlling the operation of the amplification unit selection means 30a and 30b, the microwave transmission paths 33a to 33d through which the microwave signal is transmitted are selected, and driving power is supplied to the amplification section connected to the selected microwave transmission path. As a result, the microwave signal is amplified, and the amplified microwave power signal is radiated and supplied into the heating chamber 19 from the power supply unit connected to the selected amplification unit.

  At this time, based on the microwave signal transmitted through the microwave transmission path 32a, the microwave signal transmitted through the microwave transmission path 32b is transmitted as a signal whose phase is delayed by 90 degrees. And the microwave finally radiated | emitted in the heating chamber 19 is based on the phase of the microwave radiated | emitted from the electric power feeding part 25a or the electric power feeding part 25b, and the phase of the microwave radiated | emitted from the electric power feeding part 25c or the electric power feeding part 25d Is emitted as a signal delayed by approximately 90 degrees.

  Further, the phase variable unit 26 is inserted in the microwave transmission path 32a. The phase variable unit 26 is configured using a capacitance variable element whose capacitance changes according to the applied voltage, and the phase variable range is a range from 0 degrees to about 180 degrees.

  About the microwave processing apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  Various operations related to selection of the oscillation frequency at the start of heating of the object to be heated are the same as those in the first embodiment, and the description of the operation is omitted.

  The object to be heated is stored in the heating chamber 19, the heating condition is input from the operation unit (not shown), and the heating start key is pressed to receive the heating condition and the heating start signal (34 in FIG. 2). The microwave generation unit 31 starts to operate according to the control output signal of the control unit 27. The control unit 27 controls the amplification unit selection means 30a and 30b based on the input heating condition, and determines the amplification unit to be operated at the start of heating. Thereafter, driving power is supplied to the oscillating unit 11 to oscillate a microwave having a desired oscillation frequency. Thereafter, the first amplification unit of the amplification unit selected by the amplification unit selection means 30a and 30b is operated, and then the main amplification unit is operated.

  As a result, each main amplification section outputs microwave power of 200 W to 500 W with a phase difference of 90 degrees. Then, microwaves are supplied and radiated from the power supply unit connected to the selected amplification unit into the heating chamber 19 in which the object to be heated is stored. For example, when the power feeding unit selected at the initial stage of heating is a power feeding unit 25d disposed on the right wall surface 21 and a power feeding unit 25b disposed on the bottom wall surface 22, the level of microwaves radiated from these power feeding units The phase difference is approximately 90 degrees (for example, the state where the signal of the power supply section 25d is delayed by approximately 90 degrees with reference to the signal of the power supply section 25b), and the electric field concentration of the microwave from the approximate center of the heating chamber 19 to the right wall surface 21 side. A region is formed. When the object to be heated is stored in the approximate center of the heating chamber 19 due to the electric field concentration region formed in the heating chamber 19, the right side of the object to be heated is strongly heated from the approximate center.

Then, the control unit 27 sends a control signal to the microwave generation unit 31 for switching the amplification unit to be operated based on an appropriate time period or temperature distribution information of the heated object in order to achieve uniform heating of the heated object. Output. By this control signal, the driving power to the switching target amplification unit is stopped, and the amplification unit to be operated is switched by operating the amplification unit selection means. When the switching is completed, power is supplied to the target amplification unit to operate the amplification unit.

  This series of operations will be described, for example, when the power supply unit 25d is switched to the power supply unit 25c. The switching of the power feeding unit 25d to the power feeding unit 25c is performed for the purpose of promoting heating of the object to be heated from the approximate center to the left.

  For example, in the surface temperature distribution of the object to be heated as the temperature distribution information of the object to be heated, the lowest surface temperature in the region on the left side from the approximate center of the object to be heated is 10 ° C. compared to the maximum surface temperature in the region on the right side. When the above difference is reached, the control unit 27 outputs a switching command.

  Based on this switching command, the drive power supplied to the first stage amplifier 13d and the main amplifier 15d is stopped. Then, the amplifier selection unit 30b is controlled to connect the common terminal to the terminal 301c. Thereafter, drive power is sequentially supplied to the first stage amplifier 13c and the main amplifier 15c. By this series of control operations, microwaves are supplied from the power supply unit 25 c into the heating chamber 19.

  Due to the microwave supply from both the power feeding portion 25c of the left wall surface 20 and the power feeding portion 25b of the bottom wall surface 22, the heated region starts to be strongly heated in the region closer to the left than its approximate center.

  In continuing this state, when the surface temperature rise due to the heating of the region to the left of the substantially center of the object to be heated is not good, the microwave power feeding from the power feeding unit 25b arranged on the bottom wall surface 22 is performed. Switch to microwave feed from.

  This switching control is based on the above-described switching control content from the power supply unit 25d to the power supply unit 25c, although the amplification unit to be controlled and the amplification unit selection unit are different.

  The series of switching control described above is appropriately performed during heating based on the surface temperature distribution information of the object to be heated.

  Further, by controlling the voltage applied to the phase variable section 26 inserted in the microwave transmission path 32a, the phase difference of the microwaves radiated from the two power feeding sections in operation can be made in-phase or reversed (180-degree difference). ), The propagation state of the microwave in the heating chamber 19 can be temporally changed, the local heating of the object to be heated can be eliminated, and the uniform heating can be further promoted.

  Then, heating is controlled to end based on the detection signal of the surface temperature detection means of the article to be heated and the manually input heating time information.

  According to the second embodiment described above, the amplification unit selecting means is controlled to select the position where the microwave is supplied into the heating chamber, so that heating of a specific part of the object to be heated is promoted. The entire object to be heated can be heated to a desired state by selectively switching the position where the waves are supplied.

  Also, by arranging the phase variable unit between the output of the power distribution unit and the amplification unit selecting means, the phase variable unit is controlled to change the phase of the microwave radiated from the target power supply unit with time. Accordingly, the phase difference from the microwaves output from the other power feeding units can be changed temporally to change the microwave distribution in the heating chamber, thereby further promoting the uniform heating of the object to be heated.

Further, in the plurality of power feeding unit arrangements, the amplification unit selecting means selects one of the amplification units corresponding to the pair of power feeding units arranged on the opposing wall surfaces constituting the heating chamber. By radiating microwaves from either one of the opposingly arranged power supply units according to the type, size, and quantity of the object, the heated object region near the power supply unit can be strongly heated. By utilizing this, it is possible to raise the temperature of different types of heated objects having different heat receiving efficiencies simultaneously and uniformly. As the opposing wall surface, the right and left wall surfaces or the upper and lower wall surfaces of the heating chamber have great practical value.

  Further, in the plurality of power feeding unit arrangements, the amplification unit selecting means selects one of the amplification units corresponding to the pair of power feeding units arranged on the same wall surface constituting the heating chamber. Depending on the type, size, and quantity, the heated object region on the side close to the power feeding unit can be strongly heated by radiating microwaves from either one of the power feeding units arranged oppositely. By utilizing this, it is possible to raise the temperature of different types of heated objects having different heat receiving efficiencies simultaneously and uniformly. As the same wall surface, the bottom wall surface of the heating chamber has great practical value.

  Furthermore, in the plurality of power feeding unit arrangements, the power supply unit has a pair of power feeding units arranged on the same wall surface and a pair of power feeding units arranged on the opposite wall surfaces, and the arrangement on the same wall surface is set to be a facing direction of the opposed wall surfaces. As a result, the radiation direction of the power supply unit arranged in the opposite direction and the power supply unit arranged in the same wall surface are orthogonal to each other, and the microwave of the power supply unit arranged in the same wall surface is maintained while continuing the microwave radiation from one of the power supply units arranged in the opposite direction. It is possible to promote uniform heating of the object to be heated by selectively switching the wave radiation in terms of time. In particular, the practical value can be increased by applying the heating chamber to a horizontally long rectangular parallelepiped structure.

  As described above, the microwave processing apparatus according to the present invention optimizes the radiation direction from each power supply unit by optimally arranging a plurality of power supply units having a function of radiating microwaves on the wall surface constituting the heating chamber. In addition, it is possible to provide a device that changes the microwave phase difference between the power supply units that are operating while switching the power supply unit that radiates the microwaves. Therefore, a heating device that uses dielectric heating as represented by a microwave oven It can also be applied to uses such as a microwave power source of a plasma power source that is a garbage processing machine or a semiconductor manufacturing apparatus.

Configuration diagram of microwave processing apparatus according to Embodiment 1 of the present invention The block diagram of the microwave processing apparatus in Embodiment 2 of this invention

DESCRIPTION OF SYMBOLS 10, 31 Microwave generation part 11 Oscillation part 12a, 12b, 12c Power distribution part 13a-13d, 15a-15d Amplification part 16a-16d Several output part 19 Heating chamber 20 Left wall surface (one of the opposing wall surfaces)
21 Right wall (one of the opposite walls)
22 Bottom wall (one of the other facing walls)
23 Upper wall (one of the other facing walls)
25a to 25d Feeding part 251a to 251d Opening part 252a to 252d Waveguide part 253a to 253d Supply part 26, 26a, 26b Phase variable part

Claims (6)

An oscillation unit, a power distribution unit that distributes and outputs the output of the oscillation unit to a plurality of outputs, an amplification unit that amplifies the power of the output of the power distribution unit, and a plurality of output units that outputs the output of the amplification unit, respectively A microwave generation unit having a heating chamber that houses an object to be heated, and a plurality of power supply units that supply each output of the microwave generation unit to the heating chamber, the plurality of power supply units, An opening provided on the wall surface of the heating chamber, a waveguide that covers the opening from the outside of the wall surface of the heating chamber and that has the opening as a termination side, and a microwave generated by the microwave generation unit in the waveguide portion A power supply unit configured to supply power, and in a plurality of power supply units, an opening of a power supply unit disposed on an opposing wall surface configuring the heating chamber is disposed in a parallel state, and power supply is disposed on an adjacent wall surface configuring the heating chamber The opening of the section is arranged in an orthogonal state Microwave treatment apparatus comprising a configuration. The microwave processing apparatus according to claim 1, wherein, in the plurality of power feeding units, the opening of the power feeding unit disposed on the side wall surface of the heating chamber is disposed at a position higher than the supply unit to the waveguide unit. The microwave processing apparatus according to claim 1, wherein, in the plurality of power feeding units, the opening of the power feeding unit disposed on the side wall surface of the heating chamber is disposed at substantially the center of each side wall surface. The microwave processing device according to claim 1, wherein a phase variable unit is disposed in at least one of a plurality of transmission paths for transmitting the output of the power distribution unit to the amplification unit. The microwave processing apparatus according to claim 1 , wherein a microwave phase difference between a pair of power supply units arranged on opposing wall surfaces is varied in a plurality of power supply units. The microwave processing apparatus according to claim 1 , wherein a microwave phase difference between a pair of power supply units arranged on adjacent wall surfaces is varied in a plurality of power supply units.

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