JPH088055A - Microwave heating device - Google Patents

Abstract

PURPOSE:To provide a microwave heating device which can perform highly efficient heating while preventing electric waves from leaking out of the device. CONSTITUTION:A metallic cooker 1 and a metallic lid 3 constitute a cavity, and choke structures 2 provided on the end faces of the lid 3 act to prevent microwaves which a magnetron 5 generates from leaking out of the cavity. Even if the position of the lid 3 has moved up or down, a spacer 4 provided between the lid 3 and the side face of the cooker 1 acts to ensure that leakage of the microwaves is prevented by keeping the distance between the lid 3 and the side face of the cooker 1 within a predetermined size.; also, the lid 3 is positioned to match the capacity of food to be cooked, so that this microwave heating device can achieve high heating efficiency using the magnetron 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave heating device that heats food by using radio waves.

[0002]

2. Description of the Related Art A microwave oven has been used as a microwave heating device. This microwave oven heats the food by irradiating the food with microwaves. At this time, in order to prevent microwaves from leaking from the inside of the refrigerator, one is to adopt a shield configuration in which the door and the enclosure are made of metal and are completely in contact with each other. In addition, two are provided with a radio wave trap called a choke between the door and the enclosure to prevent the microwave from leaking out of the refrigerator by utilizing the reflection inside the choke.

[0003]

However, the above-mentioned microwave oven has a problem that the heating efficiency by the magnetron is extremely low depending on the size of the food to be cooked.
In other words, the size of the inside of the microwave oven is constant, and the equivalent impedance viewed from the magnetron antenna changes as the size of the food changes. Whether or not the microwave output from the magnetron is efficiently applied to the food is determined by the impedance characteristics of the radio wave propagation system and the optimum operation characteristics of the magnetron. Therefore, if the optimum operating point of the magnetron is determined with the capacity of the cooked food as a certain value, the efficiency will be reduced except for the capacity.

The present invention solves the problems of such a conventional structure, and provides a microwave heating device capable of performing efficient heating while preventing radio wave leakage to the outside of the device. The first purpose is to do. The second and third objectives are to provide second and third means for achieving the first objective.

[0005]

[Means for Solving the Problems] A first means of the present invention for achieving the first object is to provide a metal pot having a cylindrical shape with a bottom and an opening of the pot so as to be openable and closable, and choke the end face. A metallic lid having a structure, a magnetron for generating microwaves for irradiating the food in the pot, and a spacer provided between the lid and the pot are provided, and the thickness of the spacer is set to 1 of the operating frequency of the magnetron. / 5 or less is a microwave heating device in which microwaves do not leak outside the device even when the lid is moved up and down according to the amount of food to be cooked.

A second means of the present invention for achieving the second object is, in particular, that the pot is a microwave heating device having a lid position adjusting scale.

A third means of the present invention for attaining the third object is a metallic pot having a bottomed cylindrical shape and a metallic pot having an end face which has a choke structure for opening and closing the opening of the pot. With a lid,
A magnetron for generating microwaves for irradiating the food in the pan, a spacer having a thickness of ⅕ or less of the operating frequency of the magnetron provided between the lid and the pan, and detection means for detecting the amount of the food And a lid driving motor that drives the lid up and down, and a motor driving unit that drives the lid driving motor.

[0008]

According to the first means of the present invention, the metallic pot and the metallic lid form a cavity, and the choke structure provided on the end face of the lid causes the microwave generated by the magnetron to leak to the outside of the cavity. Acts to prevent that. At this time, the spacer provided between the lid and the side surface of the pan keeps the distance between the lid and the side surface of the pan below a predetermined dimension even when the position of the lid moves up and down, so that the leakage of the microwave is surely prevented. It works. Further, at this time, by setting the position of the lid to a position corresponding to the capacity of the cooked food, a microwave heating device with high heating efficiency by the magnetron can be obtained.

The second means of the present invention is that the lid position adjusting scale provided on the inner wall of the pot acts so as to adjust the installation position of the lid according to the amount of the food, and the antenna of the magnetron. It is possible to obtain a microwave heating device which has a constant impedance as seen from the above and has high heating efficiency.

In the third means of the present invention, the lid driving motor is operated by the motor driving means which receives a signal from the detecting means for detecting the amount of food to be cooked, and the position of the lid is automatically adjusted to the amount of food to be cooked. As a response, a microwave heating device having high heating efficiency can be provided.

[0011]

EXAMPLES Examples of the first means of the microwave heating apparatus of the present invention will be described below. In this embodiment, a rice cooker will be described as an example. FIG. 1 is a schematic sectional view showing the overall structure of this embodiment. Further, FIG. 2 is a sectional view showing a main part.

Reference numeral 1 denotes a bottomed cylindrical metal pot, and rice, which is a cooking product 6, and water are contained therein. Reference numeral 3 is a metallic lid which has a choke structure 2 on its end face as shown in FIG. 2 and which covers the opening of the pot 1 in an openable and closable manner. The metallic pot 1 and the metallic lid 3 constitute a cavity 8 which is a heating space for microwaves generated by the magnetron 5. The magnetron 5 is provided on the top of the lid 3,
The antenna 9 is provided in the cavity 8. Further, the lid 3 is configured to be movable up and down with respect to the pot 1 by a device (not shown) via a spacer 4 provided between the lid 3 and the side wall of the pot 1. The spacer 4 is made of a non-magnetic material and has a thickness of ⅕ or less of the operating frequency of the magnetron 5. In this way, the size of the lid 3 including the spacer 4 is set to be slightly smaller than the inner diameter of the pot 1.

Reference numeral 7 is a magnetron driving means for driving the magnetron 5. The operation of this embodiment will be described below. When a switch (not shown) is turned on, the magnetron driving means 7 operates, the magnetron 5 starts transmitting, and the microwave is radiated from the antenna 9. This microwave heats the inside of a cavity 8 formed by a metallic pot 1 and a metallic lid 3 having a choke arrangement 2 on its end face. In this way, the cooked food 6 contained in the pan 1 is heated and rice is cooked.

At this time, according to this embodiment, the lid 3 can be moved up and down in the pot 1 by a device (not shown) through the spacer 4 made of a non-magnetic material. . The thickness of the spacer 4 is set to 1/5 or less of the operating frequency of the magnetron 5, as described above. Therefore, even if the lid 3 moves up and down in the pot 1, the distance between the lid 3 and the side wall of the pot 1 can be kept constant to the thickness of the spacer 4. That is, it is possible to keep 1/5 or less of the operating frequency of the magnetron 5. Therefore, the microwaves radiated into the cavity 8 are irrespective of the position of the lid 3,
Due to the choke structure 2 provided on the end surface of the cavity, it is impossible to leak from the inside of the cavity 8.

Further, according to the present embodiment, since the position of the lid 3 can be moved up and down in the pot 1 by a device (not shown), the impedance seen from the antenna 9 of the magnetron 5 depends on the amount of food to be cooked. It is possible to realize a microwave heating device that can maintain a constant value and has high heating efficiency.

Further, according to this embodiment, the lid 3 is provided with the spacer 4
Since it is configured to be accommodated in the pan 1 via the lid, for example, when the shape of the pan 1 is remarkably deformed by being accidentally dropped when transported to a table or the like after cooking, the lid 3 cannot be closed. Will be things. That is, when the distance between the lid 3 and the inner wall of the pot 1 cannot be kept constant and microwaves leak to the outside of the cavity 8, cooking cannot be performed. Therefore, a microwave heating device excellent in safety is realized.

Next, an embodiment of the second means of the present invention will be described with reference to FIG. In this embodiment, the pan 1 is provided with a lid position adjusting scale 10. Of course, the lid position adjusting scale 10 is adapted to the amount of food to be cooked. In this way, the lid 3 is constructed so that it can freely move up and down in the pot 1 by means of a device (not shown) as in the previous embodiment.

The operation of this embodiment will be described below. When a switch (not shown) is turned on as in the above-described embodiment, the magnetron drive means 7 operates to operate the magnetron 5
Starts transmitting and radiates a microwave from the antenna 9. This microwave heats the inside of a cavity 8 formed by a metallic pot 1 and a metallic lid 3 having a choke arrangement 2 on its end face. In this way, the cooked food 6 contained in the pan 1 is heated and rice is cooked.

At this time, according to this embodiment, the lid position adjusting scale 10 is provided on the inner wall of the pot 1. Therefore, the position of the lid 3 can be accurately set according to the amount of food to be cooked, the impedance seen from the antenna 9 of the magnetron 5 can be kept at an optimum value according to the amount of food to be cooked, and the heating efficiency is high. The microwave heating device can be realized.

Next, an embodiment of the third means of the present invention will be described with reference to FIG. Reference numeral 13 is a detection means for detecting the amount of the cooked food, and includes a sensor 13a. Reference numeral 12 is a lid driving motor that drives the lid 3 up and down, and is controlled by the motor driving means 14.

The operation of this embodiment will be described below. When a switch (not shown) is turned on as in the above-described embodiment, the magnetron drive means 7 operates to operate the magnetron 5
Starts transmitting and radiates a microwave from the antenna 9. This microwave heats the inside of a cavity 8 formed by a metallic pot 1 and a metallic lid 3 having a choke arrangement 2 on its end face. In this way, the cooked food 6 contained in the pan 1 is heated and rice is cooked.

At this time, according to this embodiment, the detection means 13
Detects the amount of food to be cooked by the sensor 13a. Specifically, the amount of cooked food is detected by emitting ultrasonic waves from the sensor 13a, measuring the time required for the ultrasonic waves to be reflected on the water surface and return. The signal of the detecting means 13 is transmitted to the motor driving means 14, and the motor driving means 14 receives the signal and drives the lid driving motor 12. Therefore, the lid 3 is automatically placed at a height according to the amount of food. That is, the lid driving motor 12 is operated by the motor driving means 14 to control the position of the lid 3 so as to be in phase with the optimum operating impedance of the magnetron 5. Therefore, the magnetron 5 can always operate under the best conditions during cooking, and realizes a microwave heating device with high heating efficiency.

[0023]

The first means of the present invention is to provide a bottomed cylindrical metal pot, a metallic lid that covers the opening of the pot so as to be openable and closable, and has a choke structure on the end face. Of the cooker for generating microwaves for irradiating the cooked food, and a spacer provided between the lid and the pan, the thickness of the spacer is set to 1/5 or less of the operating frequency of the magnetron, and the lid is cooked. A microwave heating device capable of performing efficient heating while preventing electric wave leakage to the outside of the device is configured to be moved up and down according to the amount. Provided a microwave oven with a pot structure and a lid structure that can prevent the occurrence of radio wave leakage even if the lid position is moved up and down according to the increase or decrease in the amount of objects to be heated if the lid is placed within a certain range of the pot position. it can.

In the second means of the present invention, the pot has a lid position adjusting scale, and the lid can be installed at a position corresponding to the amount of food to be cooked, and the impedance seen from the magnetron antenna is constant. It is intended to realize a microwave heating device having high heating efficiency.

A third means of the present invention is a bottomed cylindrical metal pot, a metal lid that opens and closes the opening of the pot and has a choke structure on the end face, and cooking in the pot. A magnetron for irradiating the object with microwaves, a spacer having a thickness of ⅕ or less of the operating frequency of the magnetron provided between the lid and the pan, and a detection means for detecting the amount of the cooked food,
The lid driving motor for driving the lid up and down and the motor driving means for driving the lid driving motor can be provided so that the position of the lid can be automatically adjusted according to the amount of the food. It is intended to realize a microwave heating device capable of maintaining a constant impedance as seen from above and a high heating efficiency.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a microwave heating apparatus showing an embodiment of the first means of the present invention.

FIG. 2 is a sectional view illustrating a choke structure.

FIG. 3 is a schematic sectional view of a microwave heating apparatus showing an embodiment of the second means of the present invention.

FIG. 4 is a schematic sectional view of a microwave heating apparatus showing an embodiment of the third means of the present invention.

[Explanation of symbols]

 1 Pot 2 Choke Configuration 3 Lid 4 Spacer 5 Magnetron 10 Lid Position Adjustment Scale 12 Lid Driving Motor 13 Detecting Means 14 Motor Driving Means

Claims (3)

[Claims] 1. A bottomed cylindrical metal pot, a metal lid that covers the opening of the pot so that it can be opened and closed, and has a choke structure on the end face, and microwaves that irradiate the food in the pot. A magnetron for generating and a spacer provided between the lid and the pan are provided, and the thickness of the spacer is set to ⅕ or less of the operating frequency of the magnetron, and even if the lid is moved up and down according to the amount of food to be cooked, the micro A microwave heating device that prevents waves from leaking out of the device. 2. The microwave heating device according to claim 1, wherein the pan of the microwave heating device has a lid position adjusting scale. 3. A bottomed cylindrical metal pot, a metal lid that covers the opening of the pot so that it can be opened and closed, and has a choke structure on the end face, and a microwave that irradiates the food in the pot. A magnetron to be generated, a spacer having a thickness less than ⅕ of the operating frequency of the magnetron provided between the lid and the pot, a detection means for detecting the amount of the cooked food, and a lid driving for driving the lid up and down. A microwave heating device comprising a motor and a motor driving means for driving the lid driving motor.