Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B6/00—Heating by electric, magnetic or electromagnetic fields
  • H05B6/64—Heating using microwaves
  • H05B6/72—Radiators or antennas
  • H05B6/725—Rotatable antennas
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B6/00—Heating by electric, magnetic or electromagnetic fields
  • H05B6/64—Heating using microwaves
  • H05B6/66—Circuits
  • H05B6/68—Circuits for monitoring or control
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B6/00—Heating by electric, magnetic or electromagnetic fields
  • H05B6/64—Heating using microwaves
  • H05B6/72—Radiators or antennas

Definitions

• the present invention relates to a microwave heating apparatus that dielectrically heats an object to be heated.
• a microwave oven which is a typical microwave heating device, can directly heat food, which is a typical object to be heated, so it is not necessary to prepare a pan or pot and is essential for daily life with ease.
• Device Up to now, microwave ovens have a size of about 300 to 400 mm in the width and depth dimensions and about 200 mm in the height direction. Power is generally popular.
• the width of the space for storing foods has been flattened, and the width is 400 mm or more, which is relatively larger than the depth.
• a product with a wide heating chamber shape has been put to practical use.
• the microwave wavelength used by the microwave oven is about 120 mm, and a strong electric field distribution (hereinafter referred to as radio wave distribution) is generated in the heating chamber. Furthermore, the shape of the object to be heated and its physical characteristics It is known that the effects of the above are synergistic and heating unevenness occurs. In particular, in the heating chamber having a large size in the width direction as described above, it is necessary to increase the uniformity of heating more than before in order to simultaneously heat foods placed on a plurality of dishes.
• this type of microwave heating apparatus has been difficult to locally heat the central portion of the force heating chamber, which has been provided with one radiation antenna and rotationally drives the antenna. Therefore, as a measure for improving the uniformity of heating, one having a plurality of radiation antennas or one having a plurality of high-frequency stirring means has been proposed (see Patent Document 1).
• Patent Document 1 Japanese Patent Application Laid-Open No. 2004-259646
• Patent Document 2 Japanese Patent No. 3617224
• the present invention has been made to solve the above-described problem, and provides a microwave heating apparatus that normally achieves uniform central heating in accordance with the purpose while achieving uniform heating of the entire heating chamber.
• the purpose is to do.
• the microwave heating apparatus of the present invention includes a microwave generation means, a waveguide that transmits microwaves from the microwave generation means, a heating chamber that houses an object to be heated by the microwave, A rotating antenna for radiating the microwave from the waveguide to the heating chamber, a driving means for rotating the rotating antenna, a temperature distribution detecting means for detecting a temperature distribution in the heating chamber, and the temperature Control means for controlling the direction of the rotating antenna by controlling the driving means based on the detection result of the distribution detecting means, and the control The means controls at least one of the plurality of rotating antennas in a concentrated manner by controlling a portion having a strong radiation directivity in a direction determined based on the detection result of the temperature distribution detecting means, and the driving means And a position detecting means for detecting the position of the rotating antenna.
• the microwave heating apparatus of the present invention accommodates a microwave generation means, a waveguide for transmitting microwaves from the microwave generation means, and an object to be heated by the microwave.
• a heating chamber ; a plurality of rotating antennas for radiating the microwaves from the waveguide to the heating chamber; a driving means for rotating the rotating antenna; and a temperature distribution detection for detecting a temperature distribution in the heating chamber.
• a control means for controlling the direction of the rotating antenna by controlling the driving means based on the detection result of the temperature distribution detecting means, wherein the control means is at least one of the plurality of rotating antennas.
• the two rotating antennas are configured to be centrally heated by controlling a portion having a strong radiation directivity in a direction determined based on the detection result of the temperature distribution detecting means.
• a moderate local calorific heat is realized by directing a portion of the rotating antenna having high radiation directivity to an area that needs to be heated in the heating chamber.
• the control unit controls the portion having a strong radiation directivity of the rotating antenna in a direction determined based on the detection result of the temperature distribution detection unit, thereby performing concentrated heating.
• An antenna control unit having a local heating mode control unit that performs heating and a distributed heating mode control unit that uniformly heats the heating chamber.
• the heating chamber can be centrally heated or uniformly heated.
• the antenna control unit controls the rotating antenna with the distributed heating mode control unit at an initial stage of heating, and when the initial stage ends, the local heating unit controls the local antenna. Control by heating mode controller.
• the antenna control unit controls the rotating antenna with a local heating mode control unit at an initial stage of heating, and when the initial stage is completed, the distributed heating is performed. Control by the mode controller.
• the heating chamber can be heated uniformly after being heated centrally.
• control means includes a food determination unit that determines whether or not an object to be heated placed in the heating chamber is food, and the food The rotating antenna is controlled based on the temperature of the food area determined by the determination unit.
• the rotating antenna can be controlled based on the temperature of the food area.
• the control means stores an angle of the rotating antenna when a portion having a strong radiation directivity of the rotating antenna is directed to a specific region in the heating chamber.
• An antenna angle storage section that directs a portion having a strong radiation directivity of the rotating antenna to a low temperature portion of the temperature of each detection region detected by the temperature distribution detecting means.
• the distributed heating mode control unit changes a stop position of the rotating antenna every moment, or rotates the rotating antenna continuously, or
• the configuration is such that distributed heating is performed by randomly changing the stop position of the rotating antenna.
• distributed heating can be performed by changing the stop position of the rotating antenna every moment, continuously rotating the rotating antenna, or randomly changing the stopping position of the rotating antenna. .
• the local heating mode control unit has a reciprocating angle.
• the reciprocal angle storage unit stores the reciprocal angle storage unit, and the angle determined by referring to the antenna angle storage unit based on the detection result detected by the temperature distribution detection unit is the only angle stored by the reciprocal angle storage unit.
• the rotary antenna is configured to swing back and forth.
• the rotating antenna continues to stop during the microwave radiation, so that the microwave is prevented from being excessively concentrated on a part of the rotating antenna to prevent overheating. Powering about ⁇ 5 degrees around the target angle does not affect the local heating effect on the object to be heated, but it is sufficient to prevent the antenna component from overheating.
• the local heating mode control unit includes a stop upper limit time storage unit that stores an upper limit time during which the rotating antenna stops at a predetermined angle, and the rotating antenna stops.
• a stop time counting unit that counts the time, and when the time counted by the stop time counting unit reaches the time stored in the stop upper limit time storage unit, the position is shifted to a position shifted by a predetermined angle. Move the rotating antenna.
• the rotating antenna continues to stop during microwave radiation, thereby preventing the microwave from being excessively concentrated on a part of the rotating antenna and causing excessive heating.
• the upper limit time is experimentally determined under the severest conditions where there is no heated object. Force 30 seconds to 1 minute When microwaves are concentrated locally with no load, antenna components may melt Therefore, the shorter time, for example, about 30 seconds is set as the upper limit time, and if it is exceeded, the angle is rotated by, for example, about 5 degrees.
• the temperature distribution detection means includes a plurality of infrared detection elements, and a direction in which the plurality of infrared detection elements intersects a direction in which the plurality of infrared detection elements are arranged. And a driving means for moving the device.
• a plurality of infrared detection elements can be moved in a direction that intersects the direction in which the infrared detection elements are arranged.
• the driving means includes a position detecting means for detecting a position of the rotating antenna.
• the position of the rotating antenna can be detected by the position detection means.
• the position detection unit is configured to detect the origin of the rotating antenna in the origin detection mode. With this configuration, the origin of the rotating antenna can be detected by the position detection means in the origin detection mode.
• the microwave heating apparatus of the present invention is configured such that the origin detection mode confirms the origin of the rotating antenna before the heat treatment is performed or after the heat treatment is performed.
• the origin of the rotating antenna can be confirmed before the start of heating or after the end of heating.
• control means stops the operation of the magnetron while driving the rotating antenna in the origin detection mode.
• control means includes a menu for determining that an error occurs when the origin is not detected in the origin detection mode and prohibiting execution of the heating process, and the rotating antenna.
• a menu is provided for performing heat treatment in a stopped state.
• the temperature distribution in the heating chamber may be biased according to the cooking menu.
• the heating process is performed while the operation of the rotating antenna is stopped.
• the minimum functions can be provided.
• the rotation centers of the plurality of rotating antennas are arranged at substantially equal distances from the center of the heating chamber.
• the rotation centers of the plurality of rotating antennas are arranged at approximately the same distance from the center of the heating chamber. Heating can be done by directing the part with strong radiation directivity near the center.
• the microwave heating apparatus of the present invention uses a stepping motor as the driving means, and sets the time difference for each stepping motor to the timing of inputting a pulse to each stepping motor corresponding to each antenna. Provided.
• the timing for inputting pulses to each stepping motor is provided with a time difference for each stepping motor, which eliminates the need for installing a circuit that can handle a large current and prevents an increase in circuit size. be able to.
• the invention's effect is provided with a time difference for each stepping motor, which eliminates the need for installing a circuit that can handle a large current and prevents an increase in circuit size. be able to.
• FIG. 1 is a front sectional configuration diagram of a microwave heating apparatus according to a first embodiment of the present invention.
• FIG.2 Cross-sectional side view of the microwave heating device (AA 'cross-sectional view in Fig. 1)
• FIG. 4 Diagram explaining the orientation of the rotating antenna when locally heating the vicinity of the center in the heating chamber.
• FIG. 5 Diagram explaining the orientation of the rotating antenna when locally heating the left side of the heating chamber.
• FIG. 6 Diagram explaining the orientation of the rotating antenna when the right side of the heating chamber is heated locally
• FIG. 7 is a diagram illustrating the orientation of the rotating antenna when locally heating the front of the heating chamber
• FIG. 8 A diagram for explaining the orientation of the rotating antenna when locally heating the back of the heating chamber
• FIG. 10 is a cross-sectional plan view of a microwave heating device having three rotating antennas.
• FIG. 11 Schematic cross-sectional configuration diagram of temperature distribution detection means
• FIG. 12 is a diagram for explaining an infrared temperature detection spot in the CC ′ section in FIG.
• FIG. 13 Schematic configuration diagram of control means 411
• FIG. 14 is a flowchart for explaining the control operation in the initial stage of heating.
• FIG. 15 is a flowchart for explaining the control operation in the heating feedback stage.
• FIG. 16 is a flowchart for explaining the control operation in the heating feedback stage of the second embodiment.
• FIG. 17 is a diagram showing a modification of the rotating antenna
• FIG. 18 is a diagram showing a modification of the rotating antenna
• FIG. 19 is a diagram showing a modification of the rotating antenna
• Microwave oven (microwave heating device)
• FIG. 1 to 3 are block diagrams of a microwave oven 31 that is a typical microwave heating apparatus according to the present invention.
• FIG. 1 is a cross-sectional view seen from the front
• FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG. 3 is a cross-sectional view taken along the line B-B 'of FIG. 1
• FIG. 4 is a cross-sectional view taken along the line D-D' of FIG.
• a microwave oven 31 is connected to a waveguide 33 that transmits a microwave emitted from a magnetron 32, which is a typical microwave generation means, and an upper portion of the waveguide 33.
• the widthwise dimension (about 41 Omm) is larger than the depthwise dimension (about 315 mm) and the shape of the heating chamber 34 and the heating chamber 34 for placing food (not shown), which is a typical object to be heated 34
• a mounting table 35 that is fixed inside and has a low loss dielectric material force such as ceramic and glass, and that can easily transmit microwaves, and an antenna formed below the mounting table 35 in the heating chamber 34.
• Typical drive that can rotate the rotating antennas 38 and 39 and the rotating antennas 38 and 39 Motors 40 and 41 as control means, control means 411 for controlling the directions of the rotating antennas 38 and 39 by controlling the motors 40 and 41, and an origin detecting mechanism for detecting the origin of rotation of each of the rotating antennas 38 and 39
• the infrared sensor 10 which is a temperature distribution detecting means for detecting the temperature distribution in the heating chamber 34.
• the microwave oven 31 includes a door 64 as shown in FIG.
• the setting means 63 is arranged under the 64.
• the setting means 63 allows the user to select various cooking menus according to food and cooking contents. Based on this selection result, Stage 411 can control magnetron 32 and motors 40 and 41.
• the rotating antennas 38 and 39 are configured to have radiation directivity.
• the microwave oven 31 of the first embodiment is configured to centrally heat specific foods by controlling at least one of the rotating antennas 38 and 39 having a strong radiation directivity in a predetermined direction. The specific control method will be described later.
• the rotating antennas 38 and 39 are approximately cylindrical with a diameter of about 18 mm that penetrates the coupling holes 43 and 44 having a diameter of about 30 mm provided on the boundary surface between the waveguide 33 and the bottom surface 42 of the heating chamber.
• the joints 45 and 46 which also have the same conductive material force, are integrated by being electrically connected to the upper ends of the joints 45 and 46 by crimping, welding, etc., and have a wider area in the horizontal direction than in the vertical direction.
• radiating portions 47 and 48 having conductive material power.
• the rotating antennas 38 and 39 are configured to be fitted to the shafts 49 and 50 of the motors 40 and 41 so that the centers of the coupling portions 43 and 44 are the centers of the rotational driving.
• the radiation parts 47 and 48 have a radiation directivity because the shape is not constant with respect to the direction of rotation.
• the rotation centers of the rotary antennas 38 and 39 are arranged at substantially equal distances from the center in the heating chamber 34. With this configuration, it is possible to heat the vicinity of the center of the heating chamber, which is usually difficult to heat with one antenna, by directing the strong radiation directivity of the rotating antennas 38 and 39 toward the center. .
• the waveguide 33 has a T-shape when viewed from the top as shown in FIG. 3 and is symmetrical, so that the distance from the magnetron 32 to the coupling portions 45 and 46 is equal and coupled. Since the parts 45 and 46 are attached at symmetrical positions with respect to the width direction of the heating chamber 34, the microwaves radiated from the magnetron 32 pass through the waveguide 33 and the rotating antennas 38 and 39 in the heating chamber 34. Is distributed evenly.
• the radiating portions 47 and 48 have the same shape, and the radiating portion upper surfaces 51 and 52 have a shape having an R in a substantially quadrangular shape. It is configured to have the portions 53 and 54 and limit the microwave radiation to the outside of the two sides.
• the distance between the bottom surface 42 of the heating chamber 42 and the top surfaces 51 and 52 of the radiating section is about 10 mm, and the bending sections 53 and 54 of the radiating section are pulled down to a position about 5 mm lower than that.
• the remaining two sides have different horizontal lengths from the joints 45, 46 to the end, and the joints
• the end portions 55 and 56 are about 75 mm from the center, and the end portions 57 and 58 are about 55 mm from the center of the coupling portion.
• the width in the end is 80 mm or more.
• the rotating antennas 38 and 39 can increase the radiation directivity in the direction from the coupling portions 45 and 46 to the end portions 57 and 58.
• the rotating antennas 38 and 39 that do not need to be particular about the place of placement may be rotated as in the conventional case, as in the conventional microwave oven.
• the control means 411 moves the end portions 57 and 58 of the rotating antennas 38 and 39 to the calorie heating chamber 34 as shown in FIG. It is controlled so as to be directed in a predetermined direction, ie, approximately the center in the width direction and approximately the center in the depth direction.
• control means 411 faces the ends 57 and 58 of the rotating antennas 38 and 39 to the left (the heating chamber 34 is connected to the door 64). Control it so that it is directed to the left side when viewed from the side.
• Both ends 57 and 58 of the rotating antennas 38 and 39 have a radiation directivity toward the ends 57 and 58 when the heating chamber 34 faces the left side when viewed from the door 64 side. Since it is strong, microwaves are emitted from the direction of the ends 57 and 58 in particular, and the food located in that direction can be intensively heated.
• control means 411 directs the ends 57 and 58 of the rotating antennas 38 and 39 to the right (the heating chamber 34 is a door). Control it so that it faces the right side as viewed from the 64th side.
• each antenna has a radiation directivity toward the ends 57 and 58. Since it is strong, microwaves are emitted from the direction of the ends 57 and 58 in particular, and the food located in that direction can be intensively heated.
• the control means 411 moves the end portions 57 and 58 of the rotating antennas 38 and 39 in the width direction of the heating chamber 34 as shown in FIG. It is controlled so that it is directed to the front in the approximate center and direction of the back (near the center front in the heating chamber 34).
• each antenna has a radiation directivity in the direction of the end portions 57 and 58.
• microwaves are emitted from the direction of the ends 57 and 58, and the food located in that direction can be intensively heated.
• control means 411 moves the end portions 57 and 58 of the rotating antennas 38 and 39 in the width direction of the heating chamber 34 as shown in FIG. It is controlled so that it is directed to the rear in the approximate center and the back direction (near the center rear in the heating chamber 34).
• each antenna has a radiation directivity toward the end portions 57 and 58.
• microwaves are emitted from the direction of the ends 57 and 58, and the food located in that direction can be intensively heated.
• the microwave oven 31 controls the direction of the rotating antenna in accordance with the place where it is desired to locally heat.
• a stepping motor is used as the motors 40 and 41. For example, even if the motor is a constant rotating motor, the reference position is detected and the energization time is controlled. Can be considered.
• stepping motors are used as the motors 40 and 41, and position detection means for detecting the antenna position are provided on the shafts 40 and 41 of the motors, respectively.
• This antenna position detecting means is a force that can be constituted by a known rotary encoder or potentiometer for detecting the rotational position of the rotary shaft.
• the antenna position detecting means is constituted by an origin detecting mechanism described below. That is, as shown in FIG. 9, the original inspection mechanism is composed of a disc 36a having a shaft as a central axis and a photo interrupter 36.
• the circular plate 36a is provided with a rectangular slit 36b.
• the disc 36a is commonly attached to the shafts 49 and 50 of the motors that rotate the rotating antennas 38 and 39, and is a photointerrupter including a light emitting element and a light receiving element. It rotates to block 36 light paths.
• control means 411 uses the angle of the rotating antennas 38, 39 when concentrating the highly directional portions of the rotating antennas 38, 39 at the local heating location with reference to the origin that can be detected by the origin detecting mechanism (
• the antenna angle storage unit stores the stop position in advance. When local heating is performed by controlling the operation of the rotating antennas 38 and 39, information in the antenna angle storage unit is referred to.
• the force described so far for the case of two rotating antennas is not limited to this.
• the number of rotating antennas is not limited to this, and may be two or more.
• a structure having an antenna may be used. In the state shown in Fig. 10, the end of each rotating antenna faces the center of the heating chamber, and the food located near the center can be heated intensively.
• the temperature detection means includes a plurality of infrared detection elements 13 arranged in a line on the substrate 19, a case 18 that accommodates the entire substrate 19, and a direction in which the infrared detection elements 13 are arranged in the case 18.
• the stepping motor 11 that moves in the direction that intersects perpendicularly is omitted.
• a metal can 15 enclosing the infrared detection element 13 and an electronic circuit 20 for processing the operation of the infrared detection element are provided.
• the can 15 is provided with a lens 14 through which infrared rays pass.
• the case 18 is provided with an infrared passage hole 16 through which infrared light passes and a hole 17 through which lead wires from the electronic circuit 20 pass.
• the case 18 can be moved in a direction perpendicular to the direction in which the infrared detection elements 13 are arranged in a row.
• FIG. 12 is a diagram illustrating the infrared temperature detection spot in the CC ′ section in FIG.
• the microwave oven 31 of the first embodiment can detect the temperature distribution in almost all regions in the heating chamber 34 by the reciprocating rotation of the stepping motor 11 as the temperature detecting means. Is.
• the temperature detection elements 13 for example, infrared sensors arranged in a line of the temperature detection unit simultaneously detect the temperature distribution in the regions A1 to A4 in FIG.
• the temperature detection element 13 detects the temperature distribution in the region of B1 to B4.
• the temperature detection element 13 detects the temperature distribution in the region C1 to C4, and similarly detects the temperature distribution in the region D1 to D4. .
• the stepping motor 11 rotates in reverse to detect the temperature distribution in the order of C1 to C4, B1 to B4, and A1 to A4 from the D1 to D4 region side.
• the temperature detection means can detect the entire temperature distribution in the heating chamber 34 by repeating the above operation.
• the control means 411 includes an antenna control unit 101 that controls the operation of the rotating antennas 38 and 39, a food determination unit 102 that determines whether the object to be heated placed in the heating chamber 34 is a food, a heating unit This is a configuration having an initial heating stage end determination unit 103 that determines the end of the initial stage of the process, and a heating end determination unit 104 that determines the end of the entire heating process.
• the food determination unit 102 includes an initial temperature distribution storage unit 108 that stores an initial temperature distribution of the object to be heated, a temperature increase rate calculation unit 109 that calculates a temperature increase rate per unit time of the object to be heated, When the calculated temperature rise rate is equal to or higher than a predetermined value, it is determined that the object to be heated is food. In other words, this is to determine whether it is a mounting table on which an area force object to be heated is detected or a food to be heated. This is because the mounting table transmits microwaves and hardly rises in temperature, but food easily absorbs microwaves and rises in temperature! /, And is distinguished by the difference in its characteristics.
• the heating initial stage end determination unit 103 determines, for example, a determination condition for determining that the heating initial stage has ended when the heating start force has also passed a predetermined time, and the maximum temperature of the object to be heated reaches a predetermined temperature or higher. Judgment conditions for determining that the initial stage of heating has been completed, Heating start force Judgment is made that the initial stage of the heat treatment has ended using the determination condition that determines that the initial stage of heating has ended when the maximum temperature change of the object to be heated is greater than or equal to a predetermined value. .
• the heating end determination unit 104 determines, for example, a determination condition for determining that the heating process is to be ended when the maximum temperature of the temperature distribution of the object to be heated exceeds a preset temperature, or a location determined as food. Judgment conditions for ending the heat treatment when the average temperature of the product exceeds the set temperature, and the time required for the maximum temperature of the object to be heated to reach the specified temperature, and measuring a certain percentage of the time required The end of the heat treatment is determined by a configuration in which (for example, 50%) is heat-treated as the additional heating time and then the heat treatment is terminated when the additional heating time is over.
• the antenna control unit 101 includes a distributed heating mode control unit 105 that controls the operation of the rotating antennas 38 and 39 that uniformly heat the heating chamber, and a rotating antenna 38 that heats the low-temperature portion of the object to be heated. 39, a local heating (spot heating) mode control unit 106 that controls the operation of 39, and a low-temperature part extraction unit 107 that detects a low-temperature part of an object to be heated placed in the heating chamber.
• the distributed heating mode control unit 105 changes the stop position of the two rotary antennas 38 and 39 that can be locally heated by stopping at a predetermined position during microwave oscillation. To achieve distributed heating, to rotate the rotating antennas 38 and 39 continuously, to achieve distributed heating, and to change the stopping positions of the rotating antennas 38 and 39 randomly to achieve distributed heating. This is a configuration to be realized.
• the local heating mode control unit 106 is configured to obtain information on the lowest temperature location from the low temperature part extraction unit 107 and to control the orientation of the rotating antennas 38 and 39 to perform local heating. For example, if the lowest temperature point is any of B2, B3, C2, and C3 in FIG. 12, the rotating antennas 38 and 39 are heated in the center, that is, at the stop position shown in FIG. , 39 is stopped.
• the rotating antennas 38, 39 are heated in the left direction, that is, in the stop position shown in FIG. Stop 39. Also, if the minimum temperature location is either B4 or C4 in Figure 12, The rotating antennas 38 and 39 are stopped in the direction in which the rotating antennas 38 and 39 are heated in the right direction, that is, in the stop position shown in FIG.
• the rotating antennas 38, 39 are in the direction in which the rotating antennas 38, 39 heat the front, that is, in the stop position shown in FIG. Stop.
• the rotating antennas 38 and 39 are stopped in the direction in which the rotating antennas 38 and 39 heat the rear, that is, in the direction shown in Fig. 8.
• control means 411 is a force for controlling the stop position of the rotating antennas 38 and 39 according to the lowest temperature location detected by the temperature detecting means. At this time, the rotating antenna is at a predetermined position. If the microwave is continuously radiated into the heating chamber while it is stopped, the rotating antenna itself may overheat and melt.
• the local heating mode control unit 106 of the control means 411 is configured so that the rotating antenna is about a predetermined angle (for example, ⁇ 5 degrees) around the target angle (stop position) in the local heating mode described above. Reciprocally swing. As a result, the deterioration of the rotating antenna can be prevented without affecting the local heating effect. In addition, the rotating antenna continues to stop during the microwave radiation, so that the microwave is prevented from being excessively concentrated on a part of the rotating antenna to prevent overheating.
• This reciprocating rocking operation may be performed at the time of starting local heating, but may be configured to start after a predetermined time has elapsed (for example, 30 seconds to 1 minute) after starting local heating.
• the control means 411 includes a stop upper limit time storage unit that preliminarily stores an upper limit time that allows the rotating antennas 38 and 39 to stop, and the rotation antenna stops. And a reciprocal angle storage unit for storing an angle at which the rotating antennas 38 and 39 swing back and forth.
• the rotation antenna may be rotated by a predetermined angle (for example, 5 degrees) after a predetermined time has elapsed from the start of local heating (for example, after 30 seconds to 1 minute).
• control means 411 stores the time when the rotating antennas 38 and 39 are at a predetermined stop position (angle) as the origin. Then, for example, the control means 411 executes an origin detection mode in which the origin of the rotating antennas 38 and 39 is confirmed before the heat treatment is performed or after the heat treatment is performed. To do.
• the control means 411 performs control to stop the operation of the magnetron while driving the rotating antenna in the origin detection mode.
• control unit 411 performs the origin detection mode after the end of the heating process, and waits for non-heating with the origin detected. As a result, it is possible to prevent the waiting time for the origin detection from occurring before starting the heat treatment.
• control means 411 includes a menu for determining that there is an error and prohibiting the subsequent heating process from being performed when the origin has a strong force in the origin detection mode, and the rotating antennas 38, 3 And a menu for executing the heat treatment in a state in which 9 is stopped.
• the temperature distribution in the heating chamber 34 may be biased.
• unevenness may be acceptable. Since the heat treatment is performed while the operations of 38 and 39 are stopped, the minimum functions can be provided to the user.
• control means 411 uniformly heats the entire heating chamber 34 in the distributed heating mode in the initial stage of heating, and shifts to the local heating mode when a difference in the temperature distribution in the heating chamber 34 begins to occur. It is good to do. Since there is no difference in the temperature distribution in the heating chamber 34 at the initial stage of heating, the distributed heating mode can raise the temperature of the entire heating chamber 34 efficiently.
• control means 411 may first locally heat the vicinity of the center in the heating chamber 34. Usually there is no difference in the temperature distribution in the heating chamber. When the heat treatment is started from a high state, the temperature rise is most difficult in the vicinity of the center of the heating chamber. Therefore, the entire heating chamber can be efficiently uniformly heated by first locally heating the vicinity of the center in the heating chamber 34 and then performing distributed heating to uniformly heat the entire heating chamber.
• the motors 40 and 41 that drive the respective rotating antennas 38 and 39 may be, for example, stepping motors.
• the control means 411 may control the timing of inputting pulses to the stepping motors attached to the rotary antennas 38 and 39 so as not to be simultaneously provided with a time difference for each stepping motor. If a pulse is input at the same time, the required current increases at that timing, and a circuit that can handle a large current must be installed in the microwave oven 31. An increase in size can be prevented.
• the magnetron 32 when the heat treatment is started, the magnetron 32 generates a microwave, and the microwave is transmitted into the heating chamber 34 via the waveguide (S 101).
• the temperature detection means detects the temperature distribution in the heating chamber 34 at the initial heating time, and the control means 411 stores the detection result of the temperature distribution (S102).
• control means 411 rotates, for example, the rotating antennas 38 and 39 at a constant speed in order to realize distributed heating (S103).
• the temperature detecting means detects the temperature distribution in the heating chamber 34 again (S104).
• the heating initial stage end determination unit 103 of the control means 411 includes the temperature distribution in the heating chamber in the initial heating stage detected in the stage of S102, and the heating chamber after a predetermined time detected in the stage of S104. With reference to the temperature distribution of the above, it is determined whether or not a certain condition for determining the end of the initial heating stage has been found! If the determination condition is satisfied! Or not (S 105 —No), the inside of the heating chamber 34 is dispersedly heated, and the temperature distribution in the heating chamber 34 is detected again after a predetermined time.
• the process proceeds to a step of determining whether or not each area where the temperature detecting means detects the temperature is an area where the food is placed. .
• the rate of temperature increase per unit time in each area where the temperature is detected is calculated. If the reference value is greater than or equal to the predetermined value, it is determined that food is placed in the area.
• the initial temperature is referred to for each area where the temperature is detected, and if the initial temperature is negative (for example, frozen food is assumed), the area is determined to be an area where food is placed. May be.
• the step of S106 out of all the regions in the heating chamber 34, the region where the food is placed and the other region where the food is not placed are discriminated and stored in the control means 411. Keep it. (S106).
• the microwave oven 31 proceeds to the heating feedback stage.
• the operation in the heating feedback stage will be described with reference to FIG.
• the temperature distribution detecting means of the microwave oven 31 detects the entire temperature distribution in the heating chamber 34 after the initial heating stage is completed (S107). Then, the lowest temperature region in the region where the food is determined to be placed in the heating chamber 34 is extracted, that is, the lowest temperature portion of the food portion is extracted (S108).
• the control means 411 is designed to heat the center of the rotating antenna 38, 39 outlet heat 3 chamber 34. That is, the operation control is executed so that the rotating antennas 38 and 39 are stopped at the stop position shown in FIG. 4 (S117).
• the control means 411 causes the rotating antennas 38 and 39 to heat the left in the heating chamber 34. Operation control is performed so that the rotating antennas 38 and 39 are stopped in the direction, that is, in the stop position shown in FIG. 5 (S118).
• Means 411 controls the operation so that the rotating antennas 38 and 39 are heated in the right direction in the heating chamber 34, that is, stop the rotating antennas 38 and 39 at the stop position shown in FIG. (S 119).
• the control means 411 causes the rotating antennas 38 and 39 to heat the forward direction in the heating chamber 34. Operation control is performed so that the rotating antennas 38 and 39 are stopped in the direction, that is, in the stop position shown in FIG. 7 (S120).
• control means 411 causes the rotating antennas 38 and 39 to heat the rearward direction in the heating chamber 34. Operation control is performed so that the rotating antennas 38 and 39 are stopped in the direction, that is, the stop position shown in FIG. 8 (S121).
• control means 411 rotates the rotating antennas 38 and 39 at a constant speed to make the inside of the heating chamber 34 uniform.
• the process shifts to the distributed heating mode for heating (S114).
• the control means 411 performs an end determination after executing any one of the steps S114 and S117 to S121 (S115). For example, the heat treatment end determination condition for determining that the heat treatment is to be terminated when the maximum temperature of the food temperature distribution exceeds a preset temperature, or the average temperature at the location determined as food exceeds the set temperature. It is determined whether or not the heat treatment end determination condition for determining that the heat treatment is to be completed is satisfied.
• the microwave oven 31 can intensively heat a specific portion in the heating chamber 34 by two rotating antennas, and is covered during the heat treatment. Since the temperature distribution of the food, which is a heated product, can be detected, and the food can be heated locally by applying a spot to the lowest temperature portion of the food, the food can be heated evenly.
• the local heating and the dispersion heating can be switched according to the temperature distribution of the food, that is, the microwave can be concentrated at a necessary place, so that the food can be efficiently heated in a short time. Can do.
• the order of searching for the minimum temperature portion of the food is not limited to this, and any other order may be used as long as the whole food is searched as a result. It's okay to do it!
• FIG. 16 is a flowchart for explaining the heating feedback stage of the microwave oven according to the second embodiment.
• the same components as those described above are denoted by the same reference numerals, and the description thereof is omitted.
• the process proceeds to the calorie heat feedback stage shown in FIG.
• the difference between the heating feedback control of the first embodiment shown in FIG. 15 and the heating feedback control of the second embodiment shown in FIG. 16 is the heating feedback control force of the second embodiment.
• A1 to A4, B1 to B4, CI to C4, D1 to D4 the central region A (B2, B3, C2, C3), the left region B (B1, CI) and the right region C (B4, C4) It is classified into the front area D (A2, A3) and the rear area E (D2, D3), and heating feedback is performed based on the average temperature of the food parts in the classified area.
• the temperature detecting means of the microwave oven 31 detects the entire temperature distribution in the heating chamber 34 after the heating initial stage is completed (S201).
• Central area A (B2, B3, C2, C3), left area B (B1, CI), right area C (B4, C4), front area D (A2, A3), and rear area E (D2, D3)
• the average temperature of the food part is calculated every time (S202).
• the control means 411 causes the rotating antennas 38 and 39 to heat the left side in the heating chamber 34, that is, to the stop position shown in FIG. Operation control is executed to stop the rotating antennas 38 and 39 (S211).
• the control means 411 moves the rotating antennas 38 and 39 to the front side in the heating chamber 34, that is, to the stop position shown in FIG. Operation control is executed to stop the rotating antennas 38 and 39 (S213).
• the control means 411 continues to disperse calorie that uniformly heats the inside of the heating chamber 34 by rotating the rotating antennas 38 and 39 at a constant speed. Transition to the heat mode (S208). [0135] After executing any one of steps S208 and S210 to S214, the control means makes an end determination (S209). As in the first embodiment, for example, it is determined that the heat treatment is terminated when the maximum temperature force in the temperature distribution of the food exceeds a preset temperature, or the average temperature of the location determined as food is the set temperature. It is determined whether or not the heat treatment end judgment condition for judging that the heat treatment is finished when exceeding the temperature is satisfied.
• the microwave oven 31 of the second embodiment determines the local heating location based on the average temperature of the food location within the classified fixed area (A to E). Even if only the location is extremely low, it is possible to perform centralized heating on the location where the whole food needs to be heated.
• the rotating antenna may have an opening in a part of a disk shape.
• the rotating antennas 83 and 84 have arcuate openings 87 and 88 on the radiating portions 85 and 86, respectively.
• the length L1 in the width direction is set to be one quarter or more of the wavelength of the microwave radiated into the heating chamber. Therefore, the rotating antennas 83 and 84 have a configuration in which the opening has radiation directivity when stopped, and can locally heat a specific region in the heating chamber 34.
• the rotating antenna for example, there are rectangular rotating antennas 90 and 91 as shown in FIG.
• the rotary antennas 90 and 91 have bent portions 94 and 95 in which three sides of the rectangular shape are bent toward the bottom surface of the heating chamber, and the remaining one side portions 92 and 93 are not bent but are bent.
• the side portions 92 and 93 having no directivity have a strong directivity, and a specific region in the calorie heat chamber 34 can be locally heated.
• the rotating antenna 201, 202 has power.
• the rotating antennas 201 and 202 are oriented by having bent portions 203 and 204 bent on the bottom side of the heating chamber on the four sides of the rectangular shape, and further having openings 208 and 209 on the radiating portions 206 and 207. This makes it possible to locally heat a specific area in the heating chamber 34.
• the rotating antennas are spaced 5 [mm] or more apart from each other. As a result, it is possible to prevent the rotating antennas from interfering with each other and causing a part of the rotating antennas to be damaged by excessive heating.
• a specific object to be heated can be centrally heated by controlling a portion having a high radiation directivity of the rotating antenna disposed in the heating chamber in a predetermined direction. It can also be applied to applications such as heating, thawing, ceramic heating, drying, sintering, or biochemical reaction of various dielectric materials such as products.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Constitution Of High-Frequency Heating (AREA)
• Electric Ovens (AREA)
• Control Of High-Frequency Heating Circuits (AREA)

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• 2006
  • 2006-06-19 JP JP2006169268A patent/JP4979280B2/ja not_active Expired - Fee Related
• 2007
  • 2007-06-15 CN CN2007800230730A patent/CN101473692B/zh not_active Expired - Fee Related
  • 2007-06-15 EP EP07745423.9A patent/EP2051563B1/en not_active Not-in-force
  • 2007-06-15 US US12/305,314 patent/US8525086B2/en not_active Expired - Fee Related
  • 2007-06-15 WO PCT/JP2007/062169 patent/WO2007148632A1/ja not_active Ceased

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