JPH11273852A - High-frequency heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adequately heat an object to be heated, irrespective of the state of the object to be heated. SOLUTION: A microwave oven is equipped with a wave guide 10, a magnetron 16 for emitting microwaves, a magnetron antenna 15 projecting within the wave guide 10, and a radiating antenna 13 for enlarging the expansion of the microwave. The radiating antenna 13 is held by an antenna support member 2 such that its angle can be changed. When an object to be heated is frozen, because there is much ice but little water that absorbs microwaves, the angle of the radiating antenna 13 is set at 90 deg. with respect to the magnetron antenna 15, in order to irradiate the microwave to the whole span of a heating chamber. If the object to be heated is relatively large in height, the radiating antenna 13 is directed upward in order to have the microwave irradiated towards the upper part of the heating chamber, and, if the object to be heated is relatively low in state, the radiating antenna 13 is directed downward in order to have the microwave irradiated towards the lower part of the heating chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-frequency heating device such as a microwave oven, and more particularly to a high-frequency heating device including a radiation antenna provided around a high-frequency oscillator.

[0002]

2. Description of the Related Art Conventionally, as a heating cooker for foods and the like,
There is a high-frequency heating device such as a microwave oven. The high-frequency heating device has a built-in high-frequency oscillator, and absorbs high-frequency radio waves (microwaves) supplied from the high-frequency oscillator to the object to be heated.
The object to be heated is heated by the induction loss effect.

FIG. 6 is a front sectional view schematically showing the entire structure of a microwave oven 200 which is an example of a conventional high-frequency heating device. Referring to FIG. 6, microwave oven 200 includes an exterior panel 22, a heating chamber 11 that accommodates object 17 to be heated,
A table 19 on which the object 17 is placed;
And a rotation motor 21 for rotating the rotation shaft 20.

Further, referring to FIG. 6, a conventional microwave oven 200 includes a magnetron 16 which is an example of a high-frequency oscillator.
And a radiation antenna 13 fixed to a radiation antenna supporting dielectric plate 14.

[0005] The microwave oven 200 includes a side wall 1 of the heating chamber 11.
2 is provided with the waveguide 10 facing the power supply port 23 provided therein. The waveguide 10 expands in the shape of a truncated cone in the direction of the heating chamber 11, and a magnetron 16 is attached to one side surface thereof.

[0006] The magnetron 16 is a kind of electron tube for high-frequency oscillation, and generates a microwave. The magnetron antenna 15 is a cylindrical antenna that protrudes into the waveguide 10 from one side surface of the waveguide 10. Radiation antenna 13
Is a circular flat plate-shaped antenna disposed around the magnetron antenna 15. The radiation antenna 13 is provided to increase the spread of the microwave supplied to the heating chamber 11.

[0007]

However, in the conventional microwave oven 200, despite the structure described above, the radiation range of the microwave radiated from the waveguide 10 is limited, so that the heating chamber 11 There was a bias in microwave diffusion at. Therefore, when cooking is performed using the conventional microwave oven 200, for example, even if the pizza on the short plate can be sufficiently heated, the liquor in the relatively tall sake bottle cannot be sufficiently heated. The problem still existed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-frequency heating apparatus capable of sufficiently heating an object to be heated regardless of the state of the object to be heated.

[0009]

According to a first aspect of the present invention, there is provided a high-frequency heating apparatus provided with a high-frequency oscillator for heating an object to be heated by emitting high-frequency radio waves, and for increasing the spread of the high-frequency. It is characterized by including a radiation antenna and radiation angle control means for changing the angle of the radiation antenna.

According to the first aspect of the present invention, the angle of the radiation antenna can be changed by the function of the radiation angle control means.

Thus, the high-frequency radiation range can be changed depending on the shape and the like of the object to be heated, so that a high-frequency heating apparatus capable of sufficiently heating the object to be heated can be provided regardless of the state of the object to be heated.

A high-frequency heating device according to a second aspect of the present invention further includes, in addition to the configuration of the high-frequency heating device according to the first aspect, an input operation means for selecting a desired cooking menu from a plurality of cooking menus. , The radiation angle control means,
The angle of the radiation antenna is changed according to the selected cooking menu.

According to the invention described in claim 2, according to claim 1
In addition to the operation according to the invention described in (1), the angle of the radiation antenna can be changed according to the cooking menu selected by the input operation means by the function of the radiation angle control means.

Thus, in addition to the effect according to the first aspect of the present invention, the high-frequency radiation range can be changed according to the selected cooking menu, so that the object to be heated can be more improved regardless of the state of the object to be heated. A high-frequency heating device that can be easily and sufficiently heated can be provided.

According to a third aspect of the present invention, in addition to the configuration of the high-frequency heating apparatus according to the second aspect, when the specific cooking menu is selected, the radiation angle control means may determine the specific cooking menu. The angle of the radiating antenna is changed during heating cooking according to the cooking menu of (1).

According to the invention of claim 3, according to claim 2,
In addition to the operation according to the invention described in (1), the radiation angle control means can change the angle of the radiation antenna even during heating cooking according to one cooking menu.

Thus, in addition to the effect according to the second aspect of the present invention, a high-frequency heating apparatus capable of sufficiently heating even an object to be heated whose absorption of high-frequency radio waves changes with the progress of heating. Can be provided.

According to a fourth aspect of the present invention, in addition to the configuration of the high-frequency heating apparatus according to any one of the first to third aspects, the radiating antenna is provided at a predetermined position with respect to the high-frequency oscillator. Are provided at intervals of.

According to the invention described in claim 4, according to claim 1,
In addition to the operation according to any one of the third to third aspects, the radiation antenna is provided at a predetermined interval with respect to the high-frequency oscillator.

Thus, a high-frequency radio wave is reliably transmitted from the high-frequency oscillator to the radiation antenna.

According to a fifth aspect of the present invention, in addition to the configuration of the high frequency heating apparatus according to any one of the first to fourth aspects, the radiation angle control means supports the radiation antenna. An antenna support that changes the angle of the radiating antenna by performing a predetermined reciprocating motion; a motor that generates rotational power; and a rotational power that the motor generates generates the antenna reciprocating motion of the antenna support. And a cam for converting to.

According to the invention of claim 5, according to claim 1,
In addition to the operation according to any one of claims 4 to 5, the motor generates rotational power, and the rotational power is converted into a predetermined reciprocating motion of the radiation antenna support by the action of the cam. The angle of the radiating antenna is changed by an antenna support that performs a predetermined reciprocating motion.

Thus, the angle of the radiation antenna can be changed more easily.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a microwave oven which is an embodiment of the high-frequency heating device of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing a structure of a main part of a microwave oven centering on a waveguide 10. Note that the overall structure of the microwave oven according to the present embodiment is the same as the structure of the conventional microwave oven 200 shown in FIG. 6, and therefore, the components common to the conventional microwave oven 200 shown in FIG.
The same reference numerals are given and the description is omitted.

The difference between the microwave oven in the present embodiment and the conventional microwave oven 200 is that the antenna supporting member 2 supports the radiation antenna 13 instead of the radiation antenna supporting dielectric plate 14 in FIG. That is, the angle of the radiation antenna 13 can be changed by the motor 5 or the like.
Referring to FIG. 1, radiation antenna 13 has a lower end edge covered with antenna support member 2. The antenna support member 2 is provided with holes 10 a, 1 provided on the left and right of the waveguide 10.
The left and right ends are supported outside the waveguide 10 via the Ob.

A hole 10c is provided below the hole 10a of the waveguide 10. And the antenna support member 2
Is branched at the right end, and is connected to the connecting rod 3 (see FIG. 2) through a hole 10c at one of the branches.

Radiating antenna 13 in the present embodiment
Are provided at predetermined intervals around the magnetron antenna 15. The predetermined interval is an interval at which no discharge occurs between the magnetron antenna 15 and the radiation antenna 13, and is an interval at which high-frequency radio waves are reliably transmitted from the magnetron antenna 15 to the radiation antenna 13.

Next, a method of changing the angle of the radiation antenna 13 will be described. FIG. 2 is a diagram for explaining a method of changing the angle of the radiation antenna 13. FIG.
FIG. 3 is a cross-sectional view along the III-III plane in FIG. 2. FIG.
With reference to FIG. 3 and FIG.
It is connected to the connecting rod 3 via c. The hole 10c
Has an arcuate shape. One end of the connecting rod 3 is connected to the groove 7 of the cam 4. The cam 4 is connected to a motor 5. When the cam 4 is rotated by an appropriate angle by the motor 5, the connecting rod 3 is rotated.
Moves appropriately in the groove 7. At this time, connecting rod 3
Exercises around the fulcrum 3a,
The other end of the connecting rod 3 moves in a direction opposite to the one end. Thereby, the antenna support member 2 changes the angle of the radiation antenna 13 by a desired angle. Here, the rotation angle of the cam 4, that is, the angle to be changed when changing the angle of the radiation antenna 13 can be controlled by controlling the power supply time to the motor 5.

That is, in this embodiment, the radiation antenna is supported by the antenna support member 2 and the connecting rod 3,
An antenna support that changes the angle of the radiation antenna by performing a predetermined reciprocating motion is configured. And
The motor 5 constitutes a motor that generates rotational power. The cam 4 constitutes a cam for converting the rotational power generated by the motor into a predetermined reciprocating motion of the antenna support.

The cam 4 is provided with a projection 8. The protrusion 8 is connected to the micro switch 9. The microswitch 9 is turned on by the projection 8 every time the cam 4 rotates a predetermined angle (for example, one rotation). In the microwave oven according to the present embodiment, the timing at which the cam 4 is at a predetermined rotational position, that is, the timing at which the antenna support member 2 directs the radiation antenna 10 to a predetermined angle, is determined by the timing at which the microswitch 9 is turned on. Is detected. The energization time to the motor 5 when changing the angle of the radiation antenna 13 is controlled by the time from when the microswitch 9 is turned on.

Next, the input operation means of this embodiment will be described. FIG. 4 is a diagram illustrating a control panel that is an example of the input operation unit according to the present embodiment. The control panel 6 includes a display panel 60 made of, for example, liquid crystal.
including. The control panel 6 also includes an automatic menu key 6a operated to select a desired menu from among the automatic menus 61 in which cooking proceeds according to a cooking program stored in advance. The automatic menu 61
Among the objects to be heated, "Sake no Kan", which heats sake in Tokuuchi, which is relatively tall, "Hot Milk", which heats drinks in cups such as mugs, and frozen once cooked Includes each menu of "frozen food" for reheating cooked food.

Further, the control panel 6 includes a thawing key 6b operated for thawing the frozen food material to room temperature or lower, an oven key 6c operated for oven cooking, and a cooking key for starting cooking. The start key 6d is operated to cancel the contents specified by the key operation, or the cancel key 6e is operated to temporarily stop the cooking process in progress, and is operated to warm the food for a predetermined time such as one minute. A heating key 6f, a range key 6g operated for range cooking, a grill key 6h operated for grill cooking, and a timer key 6i rotated for setting a cooking time. Also,
The control panel 6 includes a kitchen timer key 62 operated to use the microwave as a timer other than during cooking. The contents of these various key operations are displayed on the display panel 60 each time, and the user can confirm the operation contents.

The heating time of the "Sake no Kan" and "Milk Warm" menus is set in advance to a time suitable for one bottle or one cup. On the other hand, the heating time of the “frozen food” menu and the “thawing” menu selected by the thawing key 6b is determined by the timer key 6i.
Is determined in accordance with the weight or the like of the object to be heated, which is input by the user.

The microwave oven according to the present embodiment operates according to the cooking menu selected by the control panel 6.
The angle of the radiation antenna 13 is changed. Hereinafter, the change of the angle of the radiation antenna 13 corresponding to the cooking menu will be described.

First, on the control panel 6,
The case where the “decompression” menu is selected will be described.
High-frequency radio waves emitted by the magnetron 16 are absorbed by water and are hardly absorbed by ice. For the "Unzip" menu,
The frozen food is thawed to room temperature or lower, but the food that has just been taken out of the freezer at the start of cooking contains more ice than water. Therefore, even if this food is irradiated with high frequency, high frequency radio waves are hardly absorbed.

Therefore, in this case, the microwave oven of the present embodiment irradiates the entire inside of the heating chamber 11 with high frequency,
The temperature in the heating chamber 11 is raised by absorbing high frequency waves in the water vapor in the heating chamber 11, thereby trying to thaw the frozen food. Specifically, in the microwave oven according to the present embodiment, when the “defrost” menu is selected, the angle of the radiation antenna 13 is set to 90 ° with respect to the magnetron antenna 15 as shown in FIG. At this time, it is intended to irradiate the high frequency toward the entire heating chamber 11.

Next, on the control panel 6,
A case will be described in which a cooking menu in which the object to be heated is relatively tall, such as "liquor can" or "warm milk", is selected. In such a case, even if a high frequency is applied below the heating chamber 11, the water to absorb the high frequency is blocked by tableware such as a bottle or a cup and cannot absorb the high frequency.

Therefore, in such a case, the microwave oven of the present embodiment emits a high-frequency radio wave relatively upward in the heating chamber 11. Specifically, FIG.
As shown in FIG. 5, the radiating antenna 13 is directed upward from the state shown in FIG. In this case, the angle of the radiation antenna 13 with respect to the magnetron antenna 15 is preferably set between the heating chamber 11 and the magnetron 16.
Although it is affected by the positional relationship with
For example, 50 ° to 70 ° is preferable, and 60 ° to 65 °
Is more preferred.

Next, on the control panel 6,
The case where the “frozen food” menu is selected will be described. Frozen foods are relatively easy to thaw than frozen ingredients, which are cooked by a "thaw" menu. In this menu, the object to be heated is relatively short.

Therefore, in such a case, the microwave oven of the present embodiment irradiates a high frequency relatively downward in the heating chamber 11. More specifically, as shown in FIG. 5C, the radiation antenna 13 is directed downward from the state shown in FIG. I have. Note that the magnetron antenna 1 of the radiation antenna 13 in the present embodiment
The angle with respect to 5 is preferably, for example, 50 ° to 70 °, and more preferably 60 ° to 65 °.

Here, the effect of changing the angle of the radiation antenna 13 according to the selected cooking menu in the present embodiment will be described. Table 1 shows that the above-mentioned “Sake no Kan”, “Milk Warm”, “Thaw”, and “Frozen Food” menus were heated in a microwave oven.
It summarizes the temperature of the object to be heated.

[0043]

[Table 1]

It should be noted that “downward 63 °” as “the angle of the radiation antenna” in Table 1 means that the radiation antenna 13
However, as shown in FIG. 5 (c), it means that it is downward and the angle with respect to the magnetron antenna 15 is 63 °. Further, “upward 63 °” means that the radiation antenna 13 is upward and the angle with respect to the magnetron antenna 15 is 63 ° as shown in FIG.
Means that And, “90 °” means that the radiation antenna 13 is at an angle of 90 ° with respect to the magnetron antenna 15 as shown in FIG. 5A. Here, the radiation antenna 13
Table 2 shows the output and efficiency at each angle.

[0045]

[Table 2]

Referring to Table 1, first, "Sake no Kan",
Consider the "warm milk" menu. In the "Sake no Kan" menu, sake 1
In the "warm milk" menu, the cooking was performed in the case of 180 cc of milk in a general mug. In addition,
"Up and down unevenness" is the temperature difference between the upper and lower portions of the object to be heated after the cooking is performed, and "finish temperature" is such that the upper and lower portions are mixed after the cooking is performed. This is the temperature of the object to be heated when stirring.

In the “Sake no Kan” menu, when the angle of the radiating antenna is “upward 63 °”,
There is little vertical unevenness and the finishing temperature is high. Also, in the "Warm Milk" menu, "Upward 6
In the case of “3 °”, there is relatively little vertical unevenness, and the finishing temperature is higher than in other cases. Therefore, when the object to be heated is relatively tall as in both menus, the radiation antenna 13 is turned upward and the heating chamber 11 is turned up.
It can be said that it is preferable to radiate a high frequency above.

Next, the "decompression" menu will be considered. In the “thaw” menu, heating cooking was performed using 200 g of minced meat and sliced meat that had been frozen, respectively. The “thaw rate” means the rate at which the object to be heated can be thawed by cooking, and the “boil” means that the part of the object to be heated that has been boiled past the thaw by heating and cooking. It means whether there is.

In the “thawing” menu, if the angle of the radiating antenna is “90 °”, the thawing rate is relatively good for any object to be heated, and “boiled” in other cases. Regardless, "boiled" was not seen.
Therefore, when almost all the water of the object to be heated is ice, as in the “thawing” menu, it is preferable to direct the radiation antenna 13 horizontally and radiate high frequency to the entire heating chamber 11. It can be said that.

Next, the “frozen food” menu will be considered. In the “Frozen Foods” menu, 15 frozen sweets, 300 grams of frozen pilaf, 1 frozen hamburger
Each piece (200 g) was heated and cooked. The “maximum temperature” and the “minimum temperature” mean the maximum temperature and the minimum temperature, respectively, when measuring the temperature at a plurality of locations on the heated object after cooking. The “uneven heating evaluation” is an evaluation as to whether or not the object to be heated after heating and cooking has uneven temperature. Specifically, the difference between the “highest temperature” and the “lowest temperature” is 20%.
If it is less than the degree, it is "small", and if it is more than 20 degrees, it is "large".

In the “frozen food” menu, when the angle of the radiating antenna is “downward 63 °”, “irregularity of heating” is smaller than in other cases regardless of the type of the object to be heated.
The lowest temperature is higher than in other cases, even though the highest temperature is not different from the other cases. That is, the object to be heated is evenly heated. Therefore, if the object to be heated is relatively short, as in the “Frozen Food” menu,
It can be said that it is preferable to radiate high frequency below the heating chamber 11 with the radiation antenna 13 facing downward.

Strictly speaking, in the “frozen food” menu, the percentage of ice in the water content of the object to be heated is high at the start of cooking, but the ice melts as the cooking proceeds. , The proportion of ice decreases and the proportion of water increases. Accordingly, the microwave oven according to the present embodiment emits high-frequency radio waves to the entire heating chamber 11 as in the “thawing” menu at the time of starting the heating and cooking of the “frozen food” menu, and when the heating and cooking have progressed to some extent. Thus, it is more preferable to irradiate a high-frequency radio wave toward the lower side of the heating chamber 11 as described above.

Note that, in such a configuration, the angle of the radiation antenna 13 is changed from “90 °” to “downward 63” during heating according to one cooking menu.
° ”. And the timing of the angle change is, for example, to provide a temperature sensor inside the heating chamber 11,
This may be a point in time when the temperature sensor reaches a predetermined temperature. Further, when ice melts in the object to be heated and the proportion of water increases, the rate of absorption of the object in the irradiated high frequency increases. Therefore, the angle may be changed when the high-frequency distribution in the heating chamber 11 is detected and the high-frequency distribution in the heating chamber 11 is reduced to some extent. Further, the cooking time is determined by the weight or amount of the object to be heated, which is input by the timer key 6i (see FIG. 4). And
The angle may be changed at the point in time when the cooking is performed at a fixed rate (for example, half) of the determined time.

In the present embodiment described above, the radiation for changing the angle of the radiating antenna is provided by the antenna support member 2, the connecting rod 3, the cam 4, and the motor 5 provided for changing the angle of the radiating antenna 13. Angle changing means is configured.

In the above-described embodiment, the liquor in the bottle and the drink in the cup are cited as the case where the object to be heated is tall, and the frozen food such as frozen sweet potato and the frozen pilaf are cited as the case where the object to be heated is short. Although mentioned above, the present invention is not limited to this. In particular, as a short object to be heated,
In addition to the above, a popcorn set cooked in a microwave oven can also be mentioned.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[Brief description of the drawings]

FIG. 1 is a front view showing a structure of a main part centering on a waveguide of a microwave oven according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a method of changing the angle of a radiation antenna.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a diagram showing a control panel of a microwave oven according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a structure of a main part centering on a waveguide of a microwave oven according to an embodiment of the present invention.

FIG. 6 is a front sectional view schematically showing the entire configuration of a microwave oven as an example of a conventional high-frequency heating device.

[Explanation of symbols]

 2 Antenna support member 3 Connecting rod 4 Cam 5 Motor 6 Control panel 9 Micro switch 10 Waveguide 11 Heating chamber 13 Radiation antenna 16 Magnetron

Claims (5)

[Claims] 1. A high-frequency oscillator that emits high-frequency radio waves to heat an object to be heated, a radiation antenna provided around the high-frequency oscillator, and a radiation angle control unit that changes an angle of the radiation antenna. Including, high frequency heating equipment. 2. An input operation unit for selecting a desired cooking menu from a plurality of cooking menus, wherein the radiation angle control unit adjusts an angle of the radiation antenna according to the selected cooking menu. The high-frequency heating device according to claim 1, which is changed. 3. The radiation angle control means, when a specific cooking menu is selected, changes the angle of the radiation antenna during heating cooking according to the specific cooking menu. 3. The high-frequency heating device according to 2. 4. The radiating antenna is provided at a predetermined interval with respect to the high-frequency oscillator.
The high-frequency heating device according to any one of the above. 5. The radiation angle control means, comprising: an antenna support that supports the radiation antenna and changes the angle of the radiation antenna by performing a predetermined reciprocating movement; a motor that generates rotational power; The high-frequency heating apparatus according to any one of claims 1 to 4, further comprising: a cam that converts a rotational power generated by the antenna support into the predetermined reciprocating motion of the antenna support.