JP3363783B2 - High frequency heating equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention 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 cooking device for heating foods,
There is a high frequency heating device such as a microwave oven. The high-frequency heating device has a built-in high-frequency oscillator to allow the object to be heated to absorb high-frequency radio waves (microwave) supplied from the high-frequency oscillator.
The object to be heated is heated by the inductive loss effect.

FIG. 6 is a front sectional view schematically showing the overall structure of a microwave oven 200 which is an example of a conventional high frequency heating device. With reference to FIG. 6, the microwave oven 200 includes an exterior panel 22, a heating chamber 11 that houses the object to be heated 17,
A table 19 on which the object to be heated 17 is placed, and a table 19
The rotary shaft 20 is attached to the rotary shaft 20 and the rotary motor 21 that rotates the rotary shaft 20.

Further, referring to FIG. 6, a conventional microwave oven 200 is a magnetron 16 which is an example of a high frequency oscillator.
The magnetron antenna 15, the waveguide 10, and the radiation antenna 13 fixed to the radiation antenna supporting dielectric plate 14 are provided.

The microwave oven 200 includes a side wall 1 of the heating chamber 11.
The waveguide 10 is provided so as to face the power supply port 23 provided on the second side. The waveguide 10 spreads 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.

The magnetron 16 is a kind of electron tube for high frequency oscillation and generates microwaves. 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 arranged around the magnetron antenna 15. The radiation antenna 13 is provided in order to increase the spread of the microwave supplied to the heating chamber 11.

[0007]

However, in the conventional microwave oven 200, although the microwave radiation emitted from the waveguide 10 is limited in spite of the above-mentioned structure, the heating chamber 11 has a limited radiation range. There was a bias in the microwave diffusion in. Therefore, when cooking is performed using the conventional microwave oven 200, for example, although pizza on a short plate can be sufficiently heated, liquor in a relatively high sake bottle cannot be sufficiently heated. The problem still existed.

The present invention has been conceived in view of the above circumstances, and an object thereof 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, wherein a heating chamber for containing an object to be heated, a power supply port provided on a side wall of the heating chamber, and a power supply port facing the power supply port. A provided waveguide and a magnetron that is attached to one surface of the waveguide and emits microwaves that heat an object to be heated,
A magnetron antenna protruding from one surface of the waveguide into the waveguide, and no discharge is generated between the magnetron antenna and the microwave from the magnetron antenna.
In said waveguide at a predetermined interval is transmitted securely
Circular plates arranged around the magnetron antenna
-Shaped radiating antenna, an antenna supporting member that supports the radiating antenna, and is supported by the waveguide in a configuration in which an end is outside the waveguide through the hole of the waveguide, and the antenna supporting member. The angle of the radiating antenna is radiated through the member.
Change Tena to face up or face down
And a motor whose energization is controlled to be changed to .

According to the first aspect of the invention, the angle of the radiation antenna can be changed by the action of the motor . Furthermore
In addition, the radiating antenna has a predetermined size for the magnetron antenna.
Are provided at intervals of.

[0011] Thus, Ma by the shape of the object to be heated
Since the radiation range of the microwave can be changed, it is possible to provide a high-frequency heating device that can sufficiently heat an object to be heated regardless of the state of the object to be heated. Furthermore, from the magnetron antenna
The microwave is reliably transmitted to the radiating antenna.

In addition to the structure of the high frequency heating apparatus according to claim 1, the high frequency heating apparatus according to claim 2 further includes input operation means for selecting a desired cooking menu from a plurality of cooking menus. The motor changes the angle of the radiating antenna according to the selected cooking menu.

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

As a result, in addition to the effect of the invention according to claim 1, since the radiation range of the high frequency can be changed according to the selected cooking menu, the object to be heated can be more effectively discharged regardless of the state of the object to be heated. A high-frequency heating device that can be heated easily and sufficiently can be provided.

The high frequency heating apparatus according to claim 3, in addition to the configuration of the high frequency heating apparatus of claim 2, wherein the motor
When a specific cooking menu is selected, the parameter changes the angle of the radiating antenna during heating cooking according to the specific cooking menu.

According to the invention of claim 3, claim 2
In addition to the operation according to the invention described in (1), the angle of the radiating antenna can be changed by the function of the motor even during heating cooking according to one cooking menu.

As a result, in addition to the effect of the invention described in claim 2, a high-frequency heating device capable of sufficiently heating an object to be heated whose mode of absorption of high-frequency radio waves changes with the progress of heating. Can be provided.

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION A microwave oven, which is an embodiment of the high-frequency heating apparatus of the present invention, will be described below with reference to the drawings.

FIG. 1 is a front view showing the structure of the main part of the microwave oven centering on the waveguide 10. Since the entire structure of the microwave oven in the present embodiment is similar to the structure of the conventional microwave oven 200 shown in FIG. 6, the components common to the conventional microwave oven 200 shown in FIG.
The same reference numerals are given and the description thereof is omitted.

The difference between the microwave oven of the present embodiment and the conventional microwave oven 200 is that the antenna support member 2 supports the radiation antenna 13 instead of the radiation antenna support dielectric plate 14 of FIG. The angle of the radiation antenna 13 can be changed by the motor 5 or the like.
Referring to FIG. 1, the radiation antenna 13 has its lower end edge covered with the antenna support member 2. The antenna support member 2 has holes 10a, 1 provided on the left and right sides of the waveguide 10.
Both left and right ends are supported outside the waveguide 10 via 0b.

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

The radiation antenna 13 according to the present embodiment
Are provided around the magnetron antenna 15 with a predetermined space. The predetermined interval is an interval at which no discharge occurs between the magnetron antenna 15 and the radiation antenna 13, and is a distance at which high-frequency radio waves can be 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. Also, FIG.
FIG. 3 is a sectional view taken along the line III-III in FIG. 2. Figure 2
With reference to FIG. 3 and FIG.
It is connected to the connecting rod 3 via c. The hole 10c
Has a bow-like shape. One end of the connecting rod 3 is connected to the groove 7 of the cam 4. Further, the cam 4 is connected to the motor 5. Then, the cam 4 is rotated by an appropriate angle by the motor 5, so that the connecting rod 3
One end of the groove moves properly in the groove 7. At this time, the connecting rod 3
Moves around the fulcrum 3a,
The other end of the connecting rod 3 moves in the direction opposite to the one end. As a result, the antenna support member 2 changes the angle of the radiating 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 energization time to the motor 5.

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

A projection 8 is provided on the cam 4. The protruding portion 8 is connected to the micro switch 9. The micro switch 9 is turned on by the protrusion 8 every time the cam 4 rotates by 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 by the timing at which the micro switch 9 is turned on, that is, the timing at which the antenna support member 2 directs the radiation antenna 10 at a predetermined angle. Is detected. The energization time of the motor 5 when changing the angle of the radiation antenna 13 is controlled by the time from the time when the micro switch 9 is turned on.

Next, the input operation means of this embodiment will be described. FIG. 4 is a diagram showing a control panel which is an example of the input operation means of the present embodiment. The control panel 6 is, for example, a display panel 60 made of liquid crystal.
including. The control panel 6 also includes an automatic menu key 6a that is operated to select a desired menu from the automatic menu 61 in which cooking proceeds according to a prestored cooking program. Note that the automatic menu 61
Among the objects to be heated, there are "liquor cans" that heat relatively high sake in Sakeli, "warm milk" that heats drinks in cups such as mugs, and frozen after being cooked once. Includes menus for "frozen foods" for cooking cooked foods again.

Further, the control panel 6 includes a thawing key 6b which is operated for thawing the frozen food material to room temperature or lower, an oven key 6c which is operated for oven cooking, and a cooking start. 6d, a cancel key 6e, which is operated to cancel the contents specified by the key operation or to temporarily stop the cooking process that is in progress, and to warm food for a predetermined time such as 1 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 that is operated to use the microwave oven as a timer other than when 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 above-mentioned "liquor can" and "milk warming" menus is set in advance to a time suitable for a bottle of sake or a cup of tea. On the other hand, the heating time of the "frozen food" menu or the "thaw" menu selected by the thaw key 6b is set by the timer key 6i.
Is determined according to the weight of the object to be heated, etc.

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

First, in the control panel 6,
The case where the “decompress” menu is selected will be described.
The high-frequency radio waves emitted by the magnetron 16 are absorbed by water and hardly absorbed by ice. In the case of "Unzip" menu,
Frozen foods are thawed to room temperature or lower, but the foods just released from the freezer at the start of cooking contain much ice instead of water. Therefore, even if the food is irradiated with a high frequency, the high frequency radio wave is not easily absorbed.

Therefore, in this case, the microwave oven of the present embodiment irradiates the entire inside of the heating chamber 11 with a high frequency,
Water vapor in the heating chamber 11 absorbs a high frequency wave to raise the temperature in the heating chamber 11, thereby thawing the frozen food material. Specifically, in the microwave oven of 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. It is going to irradiate the whole heating chamber 11 with a high frequency.

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 “milk warm” is selected. In such a case, under the heating chamber 11, even if a high frequency is irradiated, the moisture that should absorb the high frequency is blocked by a tableware such as a bottle or a cup and cannot absorb the high frequency.

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

Next, on the control panel 6,
The case where the “frozen food” menu is selected will be described. Frozen foods are relatively easier to thaw than frozen foods that are cooked by the "thaw" menu. Also, in this menu, the object to be heated is relatively short.

Therefore, in such a case, the microwave oven of the present embodiment irradiates the microwave in the heating chamber 11 relatively downward. Specifically, as shown in FIG. 5 (c), the radiation antenna 13 is directed downward from the state shown in FIG. 5 (a), so as to irradiate a high frequency wave downward of the heating chamber 11. There is. The magnetron antenna 1 of the radiation antenna 13 according to the present embodiment
The angle with respect to 5 is preferably 50 ° to 70 °, 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 when the above menus of “liquor can”, “milk warm”, “thaw”, and “frozen food” are heated in a microwave oven,
This is a summary of the temperatures of the objects to be heated.

[0043]

[Table 1]

The "angle of radiation antenna" in Table 1 is "downward 63 °" when the radiation antenna 13
Means that it is facing downward as shown in FIG. 5C and that the angle with respect to the magnetron antenna 15 is 63 °. Further, “upward 63 °” means that the radiating antenna 13 is upward as shown in FIG. 5B and the angle with respect to the magnetron antenna 15 is 63 °.
Means being in the state of. And, “90 °” means that the radiating antenna 13 is at a 90 ° angle with respect to the magnetron antenna 15, as shown in FIG. 5 (a). Here, the radiation antenna 13
Table 2 shows the output and the efficiency at each angle.

[0045]

[Table 2]

Referring to Table 1, first, "sake no can",
Consider the "Milk Warm" menu. In the "Sake-no-kan" menu, sake that contains heated objects in sake bottle 1
In the "warm milk warming" menu, the cooked food was cooked with 180 cc of milk in a general mug. In addition,
“Upper and lower unevenness” is the temperature difference between the upper and lower parts of the object to be heated after cooking, and the “finishing temperature” is such that the upper part and the lower part are mixed after heating. It is the temperature of the object to be heated when it is stirred.

In the "liquor can" menu, when the angle of the radiation antenna is "upward 63 °", it is more than in other cases.
There is little vertical unevenness and the finishing temperature is high. Also, in the "Milk Warm" menu, "Upward 6
In the case of “3 °”, the vertical unevenness is relatively small, 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 radiating antenna 13 is directed upward and the heating chamber 11
It can be said that it is preferable to radiate a high frequency wave above.

Next, consider the "decompress" menu. In the “thaw” menu, 200 g of frozen minced meat and sliced meat were cooked as the objects to be heated. In addition, "thaw rate" means the rate at which the object to be heated can be thawed by cooking, and "boiled" means that the portion of the object to be heated that has been boiled through thawing by heating and cooking. It means whether or not there is.

In the "Thaw" menu, when the angle of the radiating antenna is "90 °", the thawing rate is relatively good for all objects to be heated, and "Boiled" is present in other cases. Regardless, I couldn't see "boiled".
Therefore, when almost all the water in the object to be heated is iced, as in the case of the "thaw" menu, it is preferable that the radiation antenna 13 is oriented horizontally and the high frequency wave is radiated to the entire heating chamber 11. It can be said that.

Next, consider the "frozen food" menu. In the "Frozen foods" menu, 15 frozen sweet potatoes, 300 grams of frozen pilaf, 1 frozen hamburger
Each plate (200 grams) was used as an object to be heated and cooked. The "maximum temperature" and the "minimum temperature" mean the maximum temperature and the minimum temperature, respectively, when the temperatures of a heated object after heating and cooking are measured at a plurality of points. The “uneven heating evaluation” is an evaluation as to whether or not there is uneven temperature in the object to be heated after cooking, and specifically, the difference between the “maximum temperature” and the “minimum temperature” is 20.
If it is less than degrees, it is “small”, and if it is 20 degrees or more, it is “large”.

In the “frozen food” menu, when the angle of the radiation antenna is “downward 63 °”, the “heating unevenness” is smaller than in other cases regardless of the kind of the object to be heated, and
Even though the maximum temperature is the same as in other cases, the minimum temperature is higher than in other cases. That is, the object to be heated is evenly heated. Therefore, if the object to be heated is relatively short, such as the "frozen food" menu,
It can be said that it is preferable to radiate a high frequency wave below the heating chamber 11 with the radiation antenna 13 facing downward.

Strictly speaking, the object to be heated in the "frozen food" menu has a large proportion of ice in the water content of the object to be heated at the start of cooking, but the ice melts as the cooking progresses. , The proportion of ice decreases and the proportion of water increases. Therefore, the microwave oven of the present embodiment irradiates high frequency radio waves to the entire heating chamber 11 at the start of heating cooking of the “frozen food” menu, as in the case of “thawing” menu, and when the heating cooking progresses to some extent. Then, as described above, it is more preferable to irradiate the high frequency radio wave downward of the heating chamber 11.

In order to configure in this way, the microwave oven is heated in accordance with one cooking menu, and the angle of the radiation antenna 13 is changed from "90 °" to "downward 63".
Change to “°”. The timing of changing the angle is, for example, by providing a temperature sensor inside the heating chamber 11,
It can be the time when the temperature sensor reaches a predetermined temperature. In addition, when ice melts in the object to be heated and the proportion of water increases, the proportion of the irradiated high frequency absorbed by the object to be heated increases. Therefore, the distribution of the high frequency in the heating chamber 11 may be detected, and the angle may be changed when the high frequency in the heating chamber 11 decreases to some extent. Further, the cooking time is determined by the weight and 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 time when the cooking is performed for a certain ratio (for example, half) of the determined time.

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

Further, in the present embodiment described above, the sake in Sake bottle and the drink in the cup are mentioned as the case where the object to be heated is tall, and the frozen foods such as frozen sushi and frozen pilaf are the case where it is short. However, the present invention is not limited to this. Especially as a short heated object,
In addition to the above, a popcorn set or the like cooked in a microwave oven can also be mentioned.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[Brief description of 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 an angle of a radiation antenna.

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

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 the microwave oven according to the embodiment of the present invention.

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

[Explanation of symbols]

2 Antenna support member 3 connecting rod 4 cams 5 motor 6 control panel 9 micro switch 10 Waveguide 11 heating chamber 13 radiating antenna 16 magnetron

─────────────────────────────────────────────────── ───Continuation of front page (56) Reference JP-A-9-320756 (JP, A) JP-A-8-148275 (JP, A) JP-A-9-102390 (JP, A) JP-A-51- 94145 (JP, A) JP 7-65947 (JP, A) JP 8-185967 (JP, A) JP 9-27389 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H05B 6/64-6/74 F24C 7/02

Claims (3)

(57) [Claims] 1. A heating chamber for accommodating an object to be heated, a power feeding port provided on a side wall of the heating chamber, a waveguide provided facing the power feeding port, and one surface of the waveguide. Installed,
A magnetron that emits microwaves to heat an object to be heated, a magnetron antenna protruding from one surface of the waveguide into the waveguide, and no discharge occurs between the magnetron antenna and the microphone from the magnetron antenna
B Inside the waveguide with a certain interval to ensure the transmission of waves
At the circle placed around the magnetron antenna
Supports the flat plate radiation antenna and this radiation antenna,
An antenna support member supported by the waveguide in a configuration in which the end is outside the waveguide through the hole of the waveguide, and the angle of the radiation antenna is radiated through the antenna support member.
Change the antenna so that it is pointing up or point it down
High-frequency heating device including a motor whose energization is controlled to be changed as described above . 2. An input operation unit for selecting a desired cooking menu from a plurality of cooking menus, wherein the motor changes the angle of the radiating antenna according to the selected cooking menu. The high frequency heating device according to claim 1. 3. The motor, when a specific cooking menu is selected, changes the angle of the radiating antenna during cooking according to the specific cooking menu.
The high frequency heating device according to claim 2.