JP2011146214A - High-frequency heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-frequency heating device which can efficiently heat a heating object such as juicy pot-au-feu. <P>SOLUTION: The device includes: a magnetron 7 emitting microwave to a heating chamber 2; a rotary antenna 10 provided on an upper end part of an antenna post 14; a drive motor 11 connected to a lower end part of the antenna post 14 through a dielectric shaft 12 having a projection 12a in the circumferential direction; a position detector 15 detecting the projection 12a; and a control means 9 which controls the drive motor 11 based on information of the position detector 15. The rotary antenna 10 includes rotating holes 10a provided on both outer periphery sides on a straight line passing the center of the antenna post 14 to be distant from the antenna post 14 by λ/2 of the wavelength λ of the microwave. The control means 9 manages the stop position of the rotary antenna 10 by means of elapsed time based on detection information of the position detector 15 in a step of heating the heating object 20, and causes the rotary antenna 10 to repeat rotation and stop several time while the rotary antenna 10 is rotated once. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a high-frequency heating device that radiates microwaves into a heating chamber using a rotating antenna to heat an object to be heated.

  In this type of conventional high-frequency heating device, every time the rotary antenna makes a round, it stops at a position where it can be heated with high heating efficiency and heats the object to be heated. There is known a high-frequency heating device that heats a rotating antenna without stopping so as to suppress it. (Patent Document 1)

JP 2009-36449 A

  In Patent Document 1 described above, when heating a single object to be heated, the rotating antenna is stopped at a position where the object to be heated can be heated with high heating efficiency, and heating is suppressed, thereby suppressing the occurrence of heating unevenness. Can be heated to the optimum temperature, but especially when cooking dishes such as potovy with a lot of moisture (potov is a dish of meat, sausage, carrots, onions, turnips cooked in soup) Each time around the rotating antenna, if it stops and heats at a position where the heated object can be heated with high heating efficiency, only the foodstuffs with strong microwaves (for example, specific carrots and turnips) are heated. However, there is a problem that so-called heating unevenness occurs in which other foods do not sufficiently pass through.

  In addition, even when the rotating antenna is always rotated without stopping during heating, when cooking food such as Potov with a lot of water is heated, uneven temperature occurs at the top and bottom of the soup, and the temperature unevenness is also observed in the ingredients. There are problems that are affected.

  The present invention solves such conventional problems and provides a high-frequency heating device that improves the heating efficiency of an object to be heated such as food, suppresses the occurrence of uneven heating, and is excellent in energy saving. It is.

In Claim 1 of this invention, the heating chamber which accommodates a to-be-heated material, the to-be-heated material mounting plate which is provided in the bottom part of this heating chamber, and mounts the said to-be-heated material, The magnetron which radiates | emits a microwave, A waveguide connected to the magnetron; a coupling hole provided in a bottom plate of the heating chamber for radiating microwaves from the waveguide to the heating chamber; and the waveguide penetrating through the coupling hole. An antenna post provided so as to face the tube and the heating chamber substantially vertically; a rotating antenna provided substantially horizontally at an upper end portion of the antenna post below the heating object placing plate; and A drive motor connected via a dielectric shaft having a protrusion in the circumferential direction at the lower end, a position detector for detecting the position of the protrusion rotated by the drive motor, and information on the position detector Control means for controlling the drive motor Provided,
The rotating antenna is provided with a rotation hole on both outer peripheral sides on a straight line passing through the center of the antenna post, separated from the antenna post by λ / 2 of the wavelength λ of the microwave,
In the step of heating the object to be heated, the control means manages the stop position of the rotating antenna from the detection information of the position detector based on the elapsed time, and rotates several times during one rotation of the rotating antenna. The stop is repeated.

  According to a second aspect of the present invention, the rotation hole provided in the rotating antenna has an opening dimension in the rotation direction of the rotating antenna set to λ / 2 of the wavelength λ of the microwave.

  Since the high-frequency heating device of the present invention is configured as described above, the heating unevenness of the object to be heated can be used not only when the object to be heated is cooked such as a lump or cooked but also when cooking a dish such as a pot with a lot of water. Can be suppressed.

It is a principal part longitudinal cross-sectional view of the high frequency heating apparatus which shows the 1st Example of this invention. It is a perspective view in the state where a part of a high-frequency heating device was cut similarly. It is a perspective view explaining the structure of a rotation antenna similarly. It is the perspective view of the state which looked at the drive motor part similarly provided in the lower part of the waveguide from the bottom. It is sectional drawing of the container similarly used for a high frequency heating apparatus. It is explanatory drawing which similarly shows the structure of a rotating antenna, and the state of heating operation. It is a timing chart which similarly shows the control method of a rotating antenna.

  Hereinafter, an embodiment of a high-frequency heating device according to the present invention will be described with reference to FIGS. 1 to 7 described above.

  In the figure, a heating chamber 2 is provided in the main body 1 of the high-frequency heating device.

  A door 3 that can be opened and closed is provided in front of the heating chamber 2 so that the object to be heated 20 can be taken in and out. When the door 3 is closed, the flange portion 18 provided in the heating chamber 2 and the door 3 are in close contact with each other. The heating chamber 2 is sealed.

  A convex portion 3 a is provided on the inner peripheral surface of the door 3, and the convex portion 3 a protrudes from a hole 18 a provided in the flange portion 17 when the door 3 is closed and is provided on the outside of the heating chamber 2. ON / OFF state of the door 3 is detected.

  On the bottom plate 2b of the heating chamber 2, a heated object placing plate 4 made of a material having a small dielectric loss is supported by weight detecting means 5 described later, and the heated object 20 is placed on the upper surface thereof. Yes.

  The weight detection means 5 is provided at two places (5a, 5b) at the front left and right corners of the heated object placing plate 4 and at one place (5c) at the rear center, and supports the heated object placing plate 4. ing.

  Information on the weight detected by the respective weight detection means 5a, 5b, 5c is input to the control means 9, and the information on the weight detected by the weight detection means 5a, 5b, 5c is summed to place the object to be heated. The weight of the object to be heated 20 placed on the plate 4 can be detected.

  A machine chamber 16 is provided between the bottom surface of the main body 1 and the heating chamber 2, and is separated from the heating chamber 2 by a thin plate constituting the casing of the heating chamber 2 so as to cut off heat or microwaves. .

  The machine room 16 includes a magnetron 7 that radiates microwaves necessary for heating the article 20 to be heated, an inverter power supply 8 that controls the microwave output generated by the magnetron 7, and a control unit 9 that controls the inverter power supply 8. It has.

  The coupling hole 13 to which the microwave is supplied is provided with the waveguide 6 passing through the coupling hole 13 and an antenna post 14 so as to face substantially vertically in the space 2a.

  The microwave radiated from the magnetron 7 passes through the waveguide 6 connected to the magnetron 7, passes through the coupling hole 13 provided in the substantially central portion of the bottom plate 2 b of the heating chamber 2, and the coupling hole 13. Is radiated to the space 2a provided between the waveguide 6 and the antenna post 14 provided substantially vertically in the space 2a, and the space 2a provided between the object mounting plate 4 and heated. Radiated to the heating chamber 2 through the object placement plate 4.

  A rotating antenna 10 made of a metal flat plate is provided substantially horizontally at the upper end portion of the antenna post 14 so as to be positioned in the space 2a, and the drive motor 11 is provided at the lower end portion via a dielectric shaft 12 with a protrusion 12a. It is connected. The rotating antenna 10 is rotated by the operation of the drive motor 11.

  A synchronous motor is used as the drive motor 11, and the rotational speed is determined by the applied frequency. The drive motor 11 used here is a motor provided with a speed reducer. When the frequency of the power supply to be applied is 50 Hz, the time required for one rotation of the output shaft is 12 seconds, and when the frequency is 60 Hz. 10 seconds. In addition, a mechanism that always rotates in a certain direction is provided.

  When the rotary antenna 10 is driven to rotate by driving the drive motor 11, the microswitch of the position detector 15 constituted by the microswitch is turned on and off by the protrusion 12a of the dielectric shaft 12, and the generated rotary antenna position detection signal is generated. Can be input to the control means 9 to detect the rotating position of the rotating antenna 10.

  Since the control means 9 is provided with means for detecting the frequency of the applied power supply before the start of heating, it rotates in the elapsed time after the microswitch of the position detector 15 is turned on according to the frequency of the power supply used. It is possible to specify the position of the rotating antenna 10 that is in operation.

  The rotating antenna 10 continuously radiates microwaves radiated to the heating chamber 2 to the object to be heated 20 by continuously rotating.

  The rotating antenna 10 is provided with a rotating hole 10a to be described later, and the object to be heated 20 is irradiated with microwaves through the rotating hole 10a so that the object to be heated 20 can be efficiently heated.

  Therefore, the position of the rotation hole 10a is provided according to the size of the object to be heated 20 (container 20a) to be heated.

  As for the size of the object to be heated 20 (container 20a), when cooking for 3 to 4 people, it is necessary to use the one having the optimum size with respect to the amount of the material, which is generally shown in FIG. Thus, an opening having a diameter of 200 to 250 mm and a depth of about 70 mm is used.

  Such a container 20a is widened from the bottom surface toward the opening on the top surface, and the bottom surface portion has a shape depicting a large arc. Therefore, the bottom surface portion in contact with the heated object placing plate 4 has a diameter of about 140 to 180 mm, and the rotation hole 10a provided in the rotating antenna 10 is provided so as to be inside the bottom surface of the container 22a.

  Specifically, the position of the rotation hole 10 a provided in the rotary antenna 10 is provided on both the outer circumference sides of the straight line passing through the center of the antenna post 14 and separated by λ / 2 of the microwave wavelength λ. (When the frequency of the microwave radiated from the magnetron 7 is 2450 MHz, the wavelength λ of the microwave is about 122 mm, and the wavelength λ / 2 of the microwave is 60 mm).

  In addition, the rotation hole 10a provided in the rotating antenna 10 has an opening dimension in the rotation direction A set to a dimension of λ / 2 of the wavelength λ of the microwave so that microwaves from below can easily pass therethrough.

  As described above, the position of the rotation hole 10a is provided on both linear outer circumferences passing through the center of the antenna post 14 so as to be separated from each other by λ / 2 of the wavelength λ of the microwave. The opening size of the rotation hole 10a is set to be 1 / 2λ of the microwave wavelength λ so that the microwave can be easily irradiated from the rotation hole 10a.

  A heater 21 is provided outside the upper portion of the heating chamber 2 and heats the upper portion of the heating chamber 2 to increase the temperature in the heating chamber 2 and heat the article 20 to be heated.

  The operation of the high-frequency heating apparatus configured as described above will be described with reference to FIGS.

  FIG. 6 shows a state in which the door 3 and the object to be heated mounting plate 4 of FIG. 2 are removed in order to explain the configuration and operation of the rotating antenna, and FIG. 7 shows a timing chart showing the control method of the rotating antenna. The horizontal axis indicates the heating time, the vertical axis indicates the operation of microwave heating and heater heating, which are heating sources, and the rotating antenna drive signal output from the control means 9 for operating the drive motor 11; FIG. 6 is a diagram showing a state of a rotating antenna position detection signal that is a signal from a position detector 15 that is input to the control means 9 as the rotating antenna 10 rotates.

  Initially, the case where stewed cooking is performed using the container 20a is demonstrated.

  The user opens the door 3 of the main body 1 and places the container 20a containing the article to be heated 20 on the article to be heated placing plate 4, and then closes the door 3 and inputs it by operating means (not shown). Then, an operation to start heating of the high-frequency heating device is performed.

  When heating is started, the control means 9 detects the weight of the object to be heated 20 by the weight detection means 5a, 5b, 5c, and the heating time T confirmed in advance according to the detected weight of the object to be heated 20. Is calculated.

  In the heating, the temperature of the soup is increased to just before boiling for a time ta immediately after the heating, and then the heating chamber 2 is heated to 130 to 140 ° C. by the heater 21 so that the heated object 20 does not cool.

  During the time ta, the soup of the object to be heated 20 is soaked in a microwave that is weak enough to prevent the soup from spilling, and the soup can be sufficiently soaked in the vegetable or the like.

  And when heating the to-be-heated material 20 for a long time with a weak microwave, it stops at every rotation of the rotating antenna 10 and heats it, so that the rotating antenna 10 can be heated above the rotating hole 10a. The to-be-heated object 20 located is heated efficiently.

  Therefore, a position 60 mm from the center of the container 20a is heated more strongly than the bottom surface, and the soup that has risen in temperature rises toward the upper surface that opens widely along the wall surface of the container 20a. Convection (I) is generated from the outer peripheral side of the container 20a toward the center part.

  Moreover, the to-be-heated material 20 located in the upper part of the rotation hole 10a is heated especially strongly, and temperature rises, and next, the rotation hole 10a moves, heating becomes weak and temperature falls.

  Thus, by repeatedly increasing and decreasing the temperature of the object to be heated 20 depending on the intensity of heating to the object to be heated 20, the soup is sucked when the temperature of the object to be heated 20 decreases, and a delicious stewed dish is completed. .

  Next, the rotating antenna 10 repeats the operation of stopping and heating for 10 seconds after rotating 90 degrees. The position to stop may be 45 degree intervals.

  The stop position is determined based on the time when the micro switch of the position detector 15 is turned on, and the subsequent stop position is determined by measuring the angle with the elapsed time. Since the time required for one rotation of the rotating antenna 10 is different, the elapsed time t1 corresponding to the frequency to be used is determined (t1 when stopping at 90 degree intervals is 3 seconds when the power supply used is 50 Hz, and 60 Hz) Is 2.5 seconds).

  Next, the case where Potov is made will be described.

  For example, the container 20a that can make 3-4 persons at a time uses a heat-resistant container having a diameter of 20 to 25 cm and a depth of about 7 cm as shown in FIG. Sausage, carrots, large onsets, onions, turnips, celery, and water, salt, and fragrances (pepper, herbs) that serve as soup are placed and placed on the heated object placing plate 4.

  In the control means 9, the weight of only the container 20a is measured in advance so that the weight of the container 20a to be used can be tared. However, the weight of the heat-resistant container that seems to be mainly used in advance is memorized, and the weight of the food can be detected by subtracting the weight of the heat-resistant container memorized at the time of heating. Anyway.

  In heating, the heating time T corresponding to the weight of the article to be heated 20, the time ta for raising the soup temperature of the article to be heated 20 to 80 ° C. just before boiling, and the cooking time tb for boiling are determined. To do.

  For heating the object 20 to be heated, the control means 9 controls the inverter power supply 8 to oscillate the magnetron 7 to emit microwaves. The radiated microwave passes through the waveguide 6 connected to the magnetron 7, passes through the coupling hole 13 provided in the substantially central portion of the bottom plate 2 b of the heating chamber 2, and the waveguide 6. And a space 2a provided between the heated object mounting plate 4 and a heated object mounting plate 4 via a coaxial path formed of an antenna post 14 provided substantially vertically in the space 2a. Through the heating chamber 2.

  Until the time of ta elapses from the start of heating, it is the time to raise the temperature of the soup of the heated object 20 just before boiling, so the heated object 20 is irradiated with a strong microwave of about 700 W, and the heated object is heated. The rotating antenna 10 continues to rotate without stopping so as not to cause heating unevenness in 20.

  When the weight of the food is around 1 kg, the heating time ta is about 7 minutes.

  And when heating time ta passes, it is trying to maintain the temperature of the heating chamber 2 at 130-140 degreeC by supplying with electricity to the heater 21 so that the to-be-heated material 20 may not cool during the next boiling heating time tb. . And the to-be-heated material 20 is heated by about 250 W of weak microwaves for the simmering heating time tb.

  The control means 9 periodically stops and rotates the rotation of the rotating antenna 10 so as to cause a temperature difference in the object to be heated 20 during the simmering heating time tb.

  The stop position of the rotating antenna 10 starts measurement of an elapsed time t1 for stopping the rotating antenna 10 with reference to a signal when the micro switch of the position detector 15 is turned on.

  For example, when the frequency of the power source to be used is 50 Hz and the rotating antenna 10 is stopped at intervals of 90 degrees, t1 is 3 seconds.

  When the ON signal is input from the micro switch of the position detector 15 after the heating time ta has elapsed, the control means 9 stops the first rotating antenna 10 and performs heating for 10 seconds in the stopped state. Thereafter, every time the rotating antenna 10 is rotated for 3 seconds, the rotating antenna 10 is stopped for 10 seconds and heating is repeated.

  Since the stop position of the rotating antenna 10 is based on the ON signal from the micro switch of the position detector 15 input every round, even if the rotation of the rotating antenna 10 is repeatedly stopped and rotated over a long period of time Since errors such as time are not accumulated, it is possible to accurately stop the rotating antenna 10 at a predetermined stop position at any time.

  By periodically stopping the rotation of the rotating antenna 10, the outer periphery of the container 20a is strongly heated in the object 20 to be heated, and a temperature difference is generated between the center and the outer periphery, thereby causing convection in the soup.

  Due to the convection boiled, the temperature difference between the top and bottom of the soup is kept small, and the heating unevenness of beef, sausage, carrots, onions, turnips, celery, etc., which are ingredients, is reduced. As a result, there is less unevenness in the taste of vegetables.

  Further, by stopping and heating the rotating antenna 10, the temperature of the object to be heated 20 located above the rotating hole 10 a rises, and then the rotating antenna 10 rotates and the position of the rotating hole 10 a moves. The temperature of the object to be heated 20 whose temperature has increased decreases. When the temperature drops, the soup is absorbed and a delicious pot is completed.

  When the boil heating time tb elapses, the remaining time is rotated without stopping the rotation of the rotating antenna 10, and the object to be heated 20 is heated and finished so that there is no temperature unevenness.

  In addition, in the high frequency heating apparatus of the present embodiment, a mark 4a (FIG. 2) indicating the bottom dimension of the container 20a is provided on the heated object placing plate 4 so that the size of the container 20a capable of efficiently heating the boiled food can be understood. May be.

  The mark 4a is shown in the form of a band with two circles so that the upper and lower limits of the size of the container 20a that can efficiently heat the boiled food can be seen.

  If it is larger or smaller than this mark 4a, a separate operation means may be provided so that the rotating antenna 10 can be continuously heated without stopping.

  As described above, according to the present embodiment, the position of the rotation hole 10a provided in the rotation antenna 10 is separated by λ / 2 of the wavelength λ of the microwave on both linear outer circumferences passing through the center of the antenna post 14. Providing a position where microwaves are easily radiated, and by setting the opening size of the rotation hole 10a to be 1 / 2λ of the wavelength λ of the microwave, microwaves can be easily irradiated from the rotation hole 10a. Thus, it is possible to suppress the occurrence of uneven heating of the heated object, not only when the heated object is cooked in a lump or cooked such as stew, but also when cooking a dish such as Potov with a lot of moisture.

DESCRIPTION OF SYMBOLS 1 Main body 2 Heating chamber 4 To-be-heated object mounting board 5 Weight detection means 6 Waveguide 7 Magnetron 9 Control means 10 Rotating antenna 10a Rotating hole 11 Drive motor 12 Dielectric shaft 12a Protrusion 13 Coupling hole 14 Antenna post 15 Position detector 20 Object to be heated 20a Container

Claims (2)

A heating chamber for storing an object to be heated, a heated object mounting plate provided on the bottom of the heating chamber for mounting the object to be heated, a magnetron for radiating microwaves, and a waveguide coupled to the magnetron A tube, a coupling hole provided in a bottom plate of the heating chamber for radiating microwaves from the waveguide to the heating chamber, and substantially perpendicular to the waveguide and the heating chamber through the coupling hole An antenna post provided to face the rotating object, a rotating antenna provided substantially horizontally at the upper end of the antenna post below the object-to-be-heated object mounting plate, and a protrusion in the circumferential direction at the lower end of the antenna post A drive motor connected via a dielectric shaft provided with a position detector, a position detector for detecting the position of the protrusion rotated by the drive motor, and a control for controlling the drive motor based on information of the position detector Means and
The rotating antenna is provided with a rotation hole on both outer peripheral sides on a straight line passing through the center of the antenna post, separated from the antenna post by λ / 2 of the wavelength λ of the microwave,
In the step of heating the object to be heated, the control means manages the stop position of the rotating antenna from the detection information of the position detector based on the elapsed time, and rotates several times during one rotation of the rotating antenna. A high frequency heating apparatus characterized by repeating the stop.   The high-frequency heating device according to claim 1, wherein the rotation hole provided in the rotation antenna has an opening size in the rotation direction of the rotation antenna set to λ / 2 of a wavelength λ of the microwave.

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