JP6507019B2 - Cooker - Google Patents

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a heating cooker, and more particularly to a heating cooker for heating an object to be heated by microwaves.

  Conventionally, a heating cooker includes a magnetron that generates microwaves to be supplied to a heating chamber, a waveguide that guides microwaves generated by the magnetron into the heating chamber, and a temperature sensor that detects a temperature increase of the magnetron. (See, for example, JP-A-2003-115375 (Patent Document 1)).

  In the heating cooker, based on the temperature rise of the magnetron detected by the temperature sensor, the output of the magnetron is controlled to suppress the temperature rise of the magnetron to prevent the failure.

Unexamined-Japanese-Patent No. 2003-115375

  However, in the above-described heating cooker, the distribution of microwave power is disturbed by the abnormal load (for example, a metal tray) in the heating chamber at the time of oscillation of the magnetron, and the wall surface temperature in the waveguide rapidly rises. There is a problem that discharge occurs between the and the wall in the waveguide. Such discharges in the waveguide can damage the waveguide or the magnetron, resulting in failure or reduced reliability.

  In the above-mentioned conventional heating cooker, the temperature of the magnetron detected by the temperature sensor hardly rises at the time of discharge occurrence in the waveguide, so it is impossible to predict or detect the occurrence of temperature discharge of the magnetron.

  Then, the subject of this invention is providing the heating cooker which can detect beforehand the sign of discharge generation | occurrence | production in a waveguide at the time of the heating driving | running which supplies a microwave in a heating chamber.

In order to solve the above-mentioned subject, the cooking-by-heating machine of this invention is
A heating chamber for containing the object to be heated;
A high frequency generator for generating microwaves supplied into the heating chamber;
A waveguide for guiding microwaves from the high frequency generator into the heating chamber;
A temperature sensor for detecting a temperature of a wall surface in the waveguide;
A control unit that controls the high frequency generator;
During the heating operation of supplying the microwaves from the high frequency generator into the heating chamber, the microwave radiation state of the high frequency generator is determined based on the temperature of the wall surface in the waveguide detected by the temperature sensor. and a determining radiation state determination unit,
An antenna that radiates microwaves of the high frequency generator protrudes into the waveguide,
A back wall is provided on the side of the waveguide opposite to the heating chamber for shorting the microwaves emitted from the antenna of the high frequency generator,
The temperature sensor is characterized in that the wall surface in the waveguide is provided on the side opposite to the heating chamber from the position facing the antenna of the high frequency generator .
Moreover, in the heating cooker of one embodiment,
A thermal fuse is provided on the side opposite to the heating chamber from the position facing the antenna of the high frequency generator in the wall surface in the waveguide.

Moreover, in the heating cooker of one embodiment,
The radiation state determination unit generates a discharge in the waveguide when the inclination of the temperature change when the temperature of the wall surface in the waveguide rises during the heating operation becomes equal to or greater than a preset threshold. Determine that there is a sign.

Moreover, in the heating cooker of one embodiment,
The control unit stops the microwave output of the high frequency generator when the radiation state determination unit determines that there is a sign that discharge will occur in the waveguide during the heating operation.

Moreover, in the heating cooker of one embodiment,
The temperature sensor detects the temperature of the wall surface of the high-frequency generator in the waveguide opposite to the antenna that radiates the microwave.

Moreover, in the heating cooker of one embodiment,
The temperature sensor detects one of a temperature of a wall surface of the high frequency generator in the waveguide opposite to an antenna that radiates microwaves of the high frequency generator or a temperature of a back wall in the waveguide.
During the heating operation, the temperature of the wall surface of the high-frequency generator in the waveguide opposite to the antenna that radiates the microwaves, or the other temperature of the back wall in the waveguide is at or above the preset upper limit temperature Then, the thermal fuse for stopping the microwave output of the high frequency generator was provided.

  As apparent from the above, according to the present invention, the radiation state is generated based on the temperature of the wall surface in the waveguide detected by the temperature sensor during the heating operation of supplying the microwaves from the high frequency generator into the heating chamber. By determining the microwave radiation state of the high frequency generator by the determination unit, it is possible to realize a heating cooker capable of detecting in advance the occurrence of discharge in the waveguide.

FIG. 1 is a front view of a heating cooker according to a first embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the heating cooker. FIG. 3: is a cross-sectional schematic diagram of the principal part containing some waveguides of the said heating cooker. FIG. 4 is a schematic view showing a schematic configuration of the heating cooker. FIG. 5: is a figure which shows the temperature of each part at the time of the abnormal temperature rise of the wall surface in the waveguide of the said heating cooker. FIG. 6: is a cross-sectional schematic diagram of the principal part containing some waveguides of the heating cooker of 2nd Embodiment of this invention. FIG. 7: is a cross-sectional schematic diagram of the principal part containing some waveguides of the heating cooker of 3rd Embodiment of this invention. FIG. 8 is a schematic cross-sectional view of the main part including a part of the waveguide of the heating cooker according to the fourth embodiment of the present invention.

  Hereinafter, the heating cooker of this invention is demonstrated in detail by embodiment of illustration.

First Embodiment
FIG. 1 shows a front view of a heating cooker according to a first embodiment of the present invention.

  As shown in FIG. 1, the heating cooker according to the first embodiment includes a rectangular parallelepiped main casing 1, a heating cabinet 2 (shown in FIG. 2) provided in the main casing 1, and a front face of the main casing 1. It has a door 3 rotatably mounted on the side.

  The door 3 is pivoted about the left side to open and close the opening of the heating chamber 2. A handle 4 is attached to the right of the door 3. Further, the heat-resistant glass 5 is disposed substantially at the center of the door 3, and the user can visually recognize the state in the heating chamber 2 through the heat-resistant glass 5. Further, a packing (not shown) made of a heat resistant resin is fixed to the rear surface of the door 3 so as to surround the heat resistant glass 5. When the door 3 is closed, the packing is in close contact with the peripheral portion of the opening of the heating chamber 2 to seal between the door 3 and the peripheral portion of the opening of the heating chamber 2.

  An operation panel 6 is provided on the right side of the front surface of the main body casing 1. The operation panel 6 has a liquid crystal display unit 7 on the upper side. Further, a power switch 8 is provided below the operation panel 6.

  Further, an exhaust port 9 is provided on the left side of the front surface of the main body casing 1, and three air intake ports 10 are provided on the lower side of the door 3 on the front surface of the main body casing 1.

  FIG. 2 shows a longitudinal cross-sectional view of the heating cooker, and is a front cross-sectional view along a vertical plane passing through the center of the heating cabinet 2. In FIG. 2, reference numerals 51 and 52 denote exhaust fans.

  As shown in FIG. 2, the antenna housing recess 12 covered by the bottom tray 11 is provided at the bottom of the heating chamber 2. The rotary antenna 13 is rotatably disposed in the antenna housing recess 12.

  Further, a magnetron 20 as an example of a high frequency generator is disposed in the main body casing 1 and on the right side in a front view of the heating chamber 2. A waveguide 21 is provided in communication with the central opening 22 at the bottom of the heating chamber 2 from the lower side of the magnetron 20. And the antenna 20a which radiates | emits the microwave of the lower side of the magnetron 20 protrudes in the waveguide 21. As shown in FIG. A back wall 21 a is provided to cover the right end of the waveguide 21 in a front view. The back wall 21 a is a shorting plate for shorting the microwaves radiated from the antenna 20 a of the magnetron 20.

  The waveguide 21 extends from the magnetron 20 side toward the central opening 22 side of the bottom of the heating chamber 2 in a top view (not shown), and the microwave propagation direction is substantially rectangular in the longitudinal direction. ing. The cross section of the waveguide 21 has a rectangular shape, and the bottom 21b is gradually shallower in the vertical direction from the side of the magnetron 20 toward the center opening 22 of the bottom of the heating chamber 2 . A semispherical stub 21c is provided on the bottom 21b of the waveguide 21 so as to project from the middle position between the magnetron 20 and the central opening 22 of the bottom of the heating chamber 2 to the central opening 22 side.

  Further, the rotary antenna driving motor 30 is disposed in the main body casing 1 and below the antenna receiving recess 12. The rotary antenna drive motor 30 rotationally drives the rotary shaft 32 penetrating the bottom 21 b of the waveguide 21 via the drive mechanism 31. The rotary shaft 32 is connected to the shaft 33 of the rotary antenna 13. The rotating shaft 32 and the shaft 33 of the rotating antenna 13 are made of ceramic or Teflon (registered trademark).

  By using a DC motor as the motor 30 for driving the rotary antenna, in the case of a heating cooker for an aircraft having a large fluctuation of the power supply frequency, the rotation unevenness of the rotary antenna 13 is eliminated and the rotation speed can be controlled.

  Moreover, FIG. 3 has shown the cross-sectional schematic diagram of the principal part containing a part of waveguide 21 of the said heating cooker.

  As shown in FIG. 3, a temperature sensor 40 for detecting the temperature of the wall surface facing the antenna 20a that radiates the microwaves of the magnetron 20 in the waveguide 21 is disposed at the bottom 21b of the waveguide 21. There is. The temperature sensor 40 is fixed so as to be in contact with the lower surface of the bottom 21 b of the waveguide 21 by the mounting bracket 41.

  FIG. 4 is a schematic view showing a schematic configuration of the heating cooker. The same reference numerals as in FIGS. 2 and 3 denote the same parts in FIG.

  As shown in FIG. 4, the heating cooker receives a detection signal from the temperature sensor 40 and controls the magnetron 20 and the like, and the control device 60 controls the magnetron 20 based on the control signal from the control device 60. And a high voltage circuit 70 for applying

  The control device 60 includes a microcomputer and an input / output circuit, and the temperature of the wall surface in the waveguide 21 detected by the temperature sensor 40 during the heating operation for supplying the microwaves from the magnetron 20 into the heating chamber 2. And a magnetron control unit 60b as an example of a control unit that controls the magnetron 20 based on the determination result of the radiation state determination unit 60a. .

  The inventor of the present invention arranges a metal rack (not shown) in the heating chamber 2 and supplies microwaves from the magnetron 20 into the heating chamber 2 in a state in which a discharge is generated in the waveguide 21. An experiment was conducted to measure the temperature change of each part when the heating operation was started.

The temperature change of each part at the time of the abnormal temperature rise of the wall surface in the waveguide 21 of the heating cooker at that time is shown in FIG. In FIG. 5, the horizontal axis represents time [sec], and the vertical axis represents temperature [° C.]. Here, in the state where the metal rack (not shown) is arranged in the heating chamber 2, the temperature change of each part when the heating operation for supplying the microwave from the magnetron 20 into the heating chamber 2 is started is the following curve. Shown in FIG.
Dashed-dotted line: temperature of the anode of the magnetron 20 thick solid line: temperature of the first wall in the waveguide 21 (temperature of the wall facing the antenna 20a of the magnetron 20)
Thin solid line: temperature of the second wall in the waveguide 21 (back wall 21a) dotted line: temperature of the stub 21c

  As shown in FIG. 5, immediately before the discharge occurs on the first wall surface (the wall surface facing the antenna 20a of the magnetron 20) in the waveguide 21 and the second wall surface (back wall 21a) in the waveguide 21. It was found that the wall temperature rose sharply.

  For example, in a state where a metal tray is disposed in the heating chamber 2 (mismatched load), heating is performed to supply microwaves from the magnetron 20 (high frequency generator) controlled by the magnetron control unit 60b into the heating chamber 2 When the operation is started, the distribution of the microwave power in the waveguide 21 is disturbed, and the temperature of the wall surface where the power density is increased in the waveguide 21 rapidly decreases. At this time, based on the temperatures of the first wall surface and the second wall surface in the waveguide 21 detected by the temperature sensor 40, the radiation state determination unit 60a determines the microwave radiation state of the magnetron 20. Then, based on the rapid temperature rise of the wall surface in the waveguide 21, it is determined whether or not the radiation state of the microwave in the waveguide 21 is abnormal, and the microwave output is stopped. Becomes possible.

  As described above, it is possible to realize the heating cooker capable of detecting in advance the occurrence of the discharge in the waveguide 21 during the heating operation of supplying the microwaves into the heating chamber 2.

  If the temperature of the wall surface in the waveguide 21 becomes equal to or higher than a predetermined judgment temperature, it may be determined that there is an abnormality in the microwave radiation state of the magnetron 20, or the wall surface in the waveguide 21. It may be determined that there is an abnormality in the microwave radiation state of the magnetron 20 when the slope of the temperature rise of the above becomes a predetermined threshold or more.

  In the heating operation by microwaves, when the inclination of the temperature change when the temperature of the wall surface in the waveguide 21 rises becomes equal to or more than the preset threshold value, the radiation state determination unit 60 a By determining that there is a sign that discharge will occur, it is possible to quickly and reliably determine the sign of the occurrence of a discharge from a rapid decrease in the temperature of the wall surface within the waveguide 21.

  Also, when the radiation state determination unit 60a determines that there is a sign that discharge will occur in the waveguide 21 during heating operation by microwaves, the microwave control of the high frequency generator 20 is stopped by the magnetron control unit 60b. A rapid decrease in the temperature of the wall surface in the wave tube 21 can be determined promptly, and the high frequency generator 20 can be reliably stopped before the discharge occurs in the waveguide 21.

  In the wall surface of the waveguide 21 facing the antenna 20a that radiates the microwaves of the magnetron 20, the power distribution of the microwaves in the waveguide 21 is disturbed due to an abnormal load or the like, and the power density becomes high. Since the rise is remarkable, the abnormality of the microwave radiation state of the magnetron 20 can be accurately determined.

  Note that error information is displayed or voiced according to the elapsed time from the start of the heating operation by microwaves to the determination by the radiation state determination unit 60a that the radiation state of the microwaves in the waveguide 21 is abnormal. The user may be notified by such means. For example, when the radiation state determination unit 60a determines that the operation state is abnormal immediately after the start of operation, there is a high possibility that the metal tray is accommodated in the heating storage 2, and thus, notification is made or If, after a while, the radiation state determination unit 60a determines that there is an abnormality, it is possible that the object to be heated is small or large, or contains little water, or the inside of the heating storage 2 is empty. As it is expensive, we notify that.

  As described above, the present invention is directed to a heating cooker such as a household microwave oven or a business microwave oven, in which a user may insert something which becomes a mismatched load in the heating cabinet 2 and discharge may occur. And discharge in the waveguide 21 can be prevented in advance, which is extremely effective in terms of safety and reliability. In particular, in a heating cooker for aircraft, safety in flight can be greatly improved by reliably preventing the occurrence of discharge.

Second Embodiment
FIG. 6: has shown the cross-sectional schematic diagram of the principal part containing a part of waveguide 21 of the heating cooker of 2nd Embodiment of this invention. The heating cooker according to the second embodiment has the same structure as the heating cooker according to the first embodiment except for the mounting position of the temperature sensor 40, and the same reference numerals are given to the same components. .

  In the heating cooker according to the second embodiment, as shown in FIG. 6, the temperature sensor 40 is attached to the outer wall surface of the back wall 21 a of the waveguide 21. Thus, the temperature sensor 40 detects the temperature of the back wall 21 a in the waveguide 21.

  According to the heating cooker of the above configuration, the temperature distribution of the microwaves in the waveguide 21 is disturbed due to abnormal load or the like, and the temperature of the back wall 21a in the waveguide 21 is increased due to the high power density. Is a point where it becomes prominent, it is possible to accurately determine the abnormality of the microwave radiation state of the magnetron 20.

  Moreover, the heating cooker of this 2nd Embodiment has an effect similar to the heating cooker of 1st Embodiment.

Third Embodiment
FIG. 7: has shown the cross-sectional schematic diagram of the principal part containing a part of waveguide 21 of the heating cooker of 3rd Embodiment of this invention. The heating cooker of the third embodiment has the same configuration as the heating cooker of the first embodiment except for the temperature fuse 50, and the same reference numerals are given to the same components.

  In the heating cooker according to the third embodiment, as shown in FIG. 7, the thermal fuse 50 is attached to the outer wall surface of the back wall 21 a of the waveguide 21. Thus, when the temperature of the back wall 21a in the waveguide 21 becomes equal to or higher than the preset upper limit temperature, the thermal fuse 50 operates to stop the microwave output of the magnetron 20.

  The power distribution of the microwave in the waveguide 21 is disturbed by the abnormal load or the like on the wall facing the antenna 20a that radiates the microwaves of the magnetron 20 in the waveguide 21 and the back wall 21a in the waveguide 21 This is where the power density is high and the temperature rise is noticeable.

  Therefore, according to the heating cooker of the above configuration, the temperature sensor 40 detects the temperature of the wall surface facing the antenna 20a that radiates the microwaves of the magnetron 20 in the waveguide 21 during the heating operation by the microwaves. The abnormality of the microwave radiation state of the magnetron 20 can be accurately determined.

  Furthermore, even when the microwave output of the magnetron 20 can not be stopped due to the temperature rise of the wall surface in the waveguide 21 detected by the temperature sensor 40 during the heating operation by the microwave, the temperature of the back wall 21a in the waveguide 21 When the temperature reaches or exceeds the preset upper limit temperature, the thermal fuse 50 operates to shut off the power supply to the high voltage circuit 70 (shown in FIG. 4), and the microwave output of the magnetron 20 is stopped.

  Therefore, damage to the magnetron 20 and the waveguide 21 can be reliably prevented, and the reliability can be improved.

Fourth Embodiment
FIG. 8 is a schematic cross-sectional view of the main part including a part of the waveguide 21 of the heating cooker according to the fourth embodiment of the present invention. The heating cooker according to the fourth embodiment has the same configuration as the heating cooker according to the third embodiment except for the mounting position of the temperature sensor 40 and the mounting position of the thermal fuse 50, and the same components are the same. Reference numbers are attached.

  In the heating cooker according to the third embodiment, as shown in FIG. 8, the temperature fuse 50 is provided on the outside of the wall facing the antenna 20a for radiating the microwaves of the magnetron 20 in the waveguide 21 of the waveguide 21. It is attached. As a result, when the temperature of the wall surface facing the antenna 20a in the waveguide 21 becomes equal to or higher than the preset upper limit temperature, the thermal fuse 50 operates to stop the microwave output of the magnetron 20.

  The power distribution of the microwave in the waveguide 21 is disturbed by the abnormal load or the like on the wall facing the antenna 20a that radiates the microwaves of the magnetron 20 in the waveguide 21 and the back wall 21a in the waveguide 21 This is where the power density is high and the temperature rise is noticeable.

  Therefore, according to the heating cooker of the above configuration, the microwave radiation state of the magnetron 20 is detected by the temperature sensor 40 detecting the temperature of the wall surface of the back wall 21a in the waveguide 21 during heating operation by microwaves. Can be accurately determined.

  Furthermore, even when the microwave output of the magnetron 20 can not be stopped due to the temperature rise of the wall surface in the waveguide 21 detected by the temperature sensor 40 during the heating operation by the microwave, it faces the antenna 20 a in the waveguide 21 When the wall surface reaches or exceeds the preset upper limit temperature, the thermal fuse 50 operates to shut off the power supply to the high voltage circuit 70 (shown in FIG. 4), and the microwave output of the magnetron 20 is stopped.

  Therefore, damage to the magnetron 20 and the waveguide 21 can be reliably prevented, and the reliability can be improved.

  Although the said 1st-4th embodiment demonstrated the heating cooker provided with the magnetron 20 as a high frequency generation apparatus, a high frequency generation apparatus is not restricted to this, The heating cooker provided with the high frequency generation apparatus of another structure The present invention may be applied.

  Further, in the first to fourth embodiments, the temperature of the wall surface facing the antenna 20a which radiates the microwaves of the high frequency generator 20 in the waveguide 21, or the temperature of the back wall 21a in the waveguide 21. In the heating cooker provided with one temperature sensor 40 for detecting one of the above, the temperature of the wall surface facing the antenna 20a for radiating the microwaves of the high frequency generator 20 in the waveguide 21 or It may be a heating cooker provided with two temperature sensors 40 for detecting both of the temperature of the back wall 21a in the wave tube 21 respectively.

  Further, the heating cooker according to the present invention supplies a microwave to a heating chamber with a mismatched load (such as a metal tray), and when the distribution of microwave power in the waveguide is disturbed, What is necessary is just to be provided with two temperature sensors which detect the temperature of the wall surface where temperature rise changes rapidly among the wall surfaces in a pipe.

  Although the specific embodiment of this invention was described, this invention is not limited to the said 1st-4th embodiment, It can change variously within the scope of this invention, and can be implemented. For example, a combination of the contents described in the first to fourth embodiments may be used as an embodiment of the present invention.

  The present invention and embodiments are summarized as follows.

The heating cooker of the present invention is
A heating chamber 2 for containing objects to be heated;
A high frequency generator 20 for generating a microwave supplied into the heating chamber 2;
A waveguide 21 for guiding the microwaves from the high frequency generator 20 into the heating chamber 2;
A temperature sensor 40 for detecting the temperature of the wall surface in the waveguide 21;
A control unit 60b for controlling the high frequency generator 20;
During the heating operation for supplying the microwaves from the high frequency generator 20 into the heating chamber 2, the temperature of the wall surface in the waveguide 21 detected by the temperature sensor 40 is used. And a radiation state determination unit 60a that determines the radiation state of the microwaves.

  According to the above configuration, for example, in a state where the metal tray is disposed in the heating chamber 2, the heating operation for supplying the microwaves from the high frequency generator 20 controlled by the control unit 60b into the heating chamber 2 is started Then, the distribution of microwave power in the waveguide 21 is disturbed, and the temperature of the wall surface where the power density is increased in the waveguide 21 rapidly decreases. At this time, based on the temperature of the wall surface in the waveguide 21 detected by the temperature sensor 40, the radiation state determination unit 60a determines the radiation state of the microwave of the high frequency generator 20. Therefore, during the heating operation in which the microwaves are supplied into the heating chamber 2, it is possible to detect in advance the occurrence of the discharge in the waveguide 21. Then, based on the rapid temperature rise of the wall surface in the waveguide 21, it is determined whether or not the radiation state of the microwave in the waveguide 21 is abnormal, and the microwave output is stopped. Becomes possible.

  Here, the radiation state determination unit 60a determines that there is an abnormality in the microwave radiation state of the high frequency generator 20 when the temperature of the wall surface in the waveguide 21 becomes equal to or higher than a predetermined determination temperature. Alternatively, it may be determined that the microwave radiation state of the high frequency generator 20 is abnormal when the inclination of the temperature rise of the wall surface in the waveguide 21 becomes equal to or more than a predetermined threshold.

Moreover, in the heating cooker of one embodiment,
In the heating operation, the radiation state determination unit 60a sets the inside of the waveguide 21 when the inclination of the temperature change when the temperature of the wall surface in the waveguide 21 rises is equal to or more than a preset threshold. It is determined that there is a sign that discharge will occur.

  According to the above-described embodiment, when the inclination of the temperature change when the temperature of the wall surface in the waveguide 21 rises during the heating operation becomes equal to or more than the preset threshold, the radiation state determination unit 60 a By determining that there is a sign that discharge will occur in the tube 21, it is possible to quickly and reliably determine the sign of the occurrence of a discharge from the rapid decrease in the temperature of the wall surface in the waveguide 21.

Moreover, in the heating cooker of one embodiment,
When the radiation state determination unit 60a determines that there is a sign that discharge will occur in the waveguide 21 during the heating operation, the control unit 60b stops the microwave output of the high frequency generator 20.

  According to the above embodiment, when the radiation state determination unit 60a determines that there is a sign that discharge will occur in the waveguide 21 during heating operation, the control unit 60b stops the microwave output of the high frequency generator 20. A rapid decrease in the temperature of the wall surface in the waveguide 21 can be determined promptly, and the high frequency generator 20 can be reliably stopped before the discharge occurs in the waveguide 21.

Moreover, in the heating cooker of one embodiment,
The temperature sensor 40 detects the temperature of the wall surface of the waveguide 21 facing the antenna 20 a that radiates the microwaves of the high frequency generator 20.

  According to the above-described embodiment, the wall surface of the waveguide 21 facing the antenna 20a that radiates the microwaves of the high frequency generating device 20 has a disordered distribution of microwave power in the waveguide 21 due to an abnormal load, etc. Since the power density is high and the temperature rise is remarkable, it is possible to accurately determine the abnormality of the microwave radiation state of the high frequency generator 20.

Moreover, in the heating cooker of one embodiment,
The temperature sensor 40 detects the temperature of the back wall 21 a in the waveguide 21.

  Here, the back wall 21 a is a short circuit plate provided to close one end of the waveguide 21, and shorts the microwaves radiated from the high frequency generator 20.

  According to the above embodiment, the temperature of the back wall 21a in the waveguide 21 is such that the distribution of the microwave power in the waveguide 21 is disturbed due to an abnormal load or the like, the power density becomes high, and the temperature rise becomes remarkable. Therefore, the abnormality of the radiation state of the microwaves of the high frequency generator 20 can be accurately determined.

Moreover, in the heating cooker of one embodiment,
The temperature sensor 40 is one of the temperature of the wall surface facing the antenna 20a that radiates the microwaves of the high frequency generator 20 in the waveguide 21 or the temperature of the back wall 21a in the waveguide 21. While detecting
At the time of the heating operation, the temperature of the wall surface facing the antenna 20a which radiates the microwaves of the high frequency generator 20 in the waveguide 21 or the temperature of the back wall 21a in the waveguide 21 is in advance The temperature fuse 50 is provided to stop the microwave output of the high frequency generator 20 when the temperature exceeds the set upper limit temperature.

  The wall surface facing the antenna 20a of the high frequency generator 20 in the waveguide 21 and the back wall 21a in the waveguide 21 distribute the microwave power in the waveguide 21 due to abnormal load or the like. Is a place where the power density is increased and the temperature rise becomes remarkable. Therefore, the temperature sensor 40 detects one of the temperature of the wall surface facing the antenna 20 a of the high frequency generator 20 in the waveguide 21 and the temperature of the back wall 21 a in the waveguide 21. Then, the abnormality of the radiation state of the microwave of the high frequency generator 20 can be accurately determined.

  Furthermore, even when the microwave output of the high frequency generator 20 can not be stopped due to the temperature rise of the wall surface in the waveguide 21 detected by the temperature sensor 40 during the heating operation, the micro size of the high frequency generator 20 in the waveguide 21 If the temperature of the wall facing the antenna 20a that radiates the wave or the other of the temperature of the back wall 21a in the waveguide 21 is equal to or higher than a preset upper limit temperature, the microwave output of the high frequency generator 20 is 50 makes it possible to stop. Therefore, damage to the high frequency generator 20 and the waveguide 21 can be reliably prevented by the double safety measures using the temperature sensor and the temperature fuse, and the reliability can be improved.

DESCRIPTION OF SYMBOLS 1 ... Body casing 2 ... Heating storage 3 ... Door 4 ... Handle 5 ... Heat-resistant glass 6 ... Operation panel 7 ... Liquid crystal display part 8 ... Power switch 9 ... Exhaust port 10 ... Intake port 11 ... Bottom tray 12 ... Antenna accommodation recess 13 ... Rotating antenna 20 ... Magnetron (high frequency generator)
DESCRIPTION OF SYMBOLS 20a ... Antenna 21 ... Waveguide 21a ... Back wall 21b ... Bottom part 21c ... Stub 22 ... Central opening 30 ... Motor for driving a rotation antenna 31 ... Drive mechanism 32 ... Rotation axis 33 ... Shaft part 40 ... Temperature sensor 50 ... Temperature fuse 60 ... Control device 60a ... Radiation state determination unit 60b ... Magnetron control unit (control unit)
70 ... high voltage circuit

Claims (5)

A heating chamber for containing the object to be heated;
A high frequency generator for generating microwaves supplied into the heating chamber;
A waveguide for guiding microwaves from the high frequency generator into the heating chamber;
A temperature sensor for detecting a temperature of a wall surface in the waveguide;
A control unit that controls the high frequency generator;
The microwave radiation state of the high frequency generator is determined based on the temperature of the wall surface in the waveguide detected by the temperature sensor during heating operation to supply the microwave from the high frequency generator into the heating chamber. and a determining radiation state determination unit,
An antenna that radiates microwaves of the high frequency generator protrudes into the waveguide,
A back wall is provided on the side of the waveguide opposite to the heating chamber for shorting the microwaves emitted from the antenna of the high frequency generator,
The heating cooker characterized in that the temperature sensor is provided on a side opposite to the heating chamber from a position facing the antenna of the high frequency generator in a wall surface in the waveguide . In the heating cooker according to claim 1,
A heating cooker characterized in that a temperature fuse is provided on the side opposite to the heating chamber from the position facing the antenna of the high frequency generator of the wall surface in the waveguide. In the heating cooker according to claim 1 or 2 ,
The radiation state determination unit generates a discharge in the waveguide when the inclination of the temperature change when the temperature of the wall surface in the waveguide rises during the heating operation becomes equal to or greater than a preset threshold. A heating cooker characterized by judging that there is a sign. In the heating cooker according to claim 3 ,
The heating cooker characterized in that the control unit stops the microwave output of the high frequency generating device when the radiation state determination unit determines that there is a sign that discharge will occur in the waveguide during the heating operation. . The heating cooker according to any one of claims 1 to 4 .
The heating cooker characterized in that the temperature sensor detects a temperature of a wall surface of the high frequency generator in the waveguide opposite to an antenna that radiates microwaves.

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