JPH09273759A - Microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make heat in a heating chamber hard to escape at the time of heating cooking and enhance heating efficiency. SOLUTION: An exhaust duct 22 for allowing an exhaust outlet 23 in an upper portion of a side face of an inner box 13 to communicate with an exhaust outlet 24 in a bottom 11a of an outer box is provided in such a manner as to form a space 26 between an inner face of the outer box 11 and an outer side face of the inner box 13 having an interior functioning as a heating chamber 12. Even if heat in the heating chamber 12 has escaped to the exhaust duct side 22 at the time of cooking by use of a heater 15, the heat is not discharged easily out of the exhaust outlet 24 but is retained in an upper portion within the exhaust duct 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave oven equipped with a heater for heating an object to be cooked.

[0002]

A conventional structure of this type of microwave oven will be described with reference to FIG. Inside the outer box 1, an inner box 3 having a heating chamber 2 inside is arranged. A magnetron 4 for range cooking is arranged outside the right side surface of the inner box 3, and a heater 5 for heating a heater is arranged above the heating chamber 2. An intake duct 6 is provided between the outer box 1 and the inner box 3 for communicating the intake port 1a formed on the right side surface of the outer box 1 and the intake port 3a formed on the upper right side surface of the inner box 3. In addition, an exhaust duct 7 that connects the exhaust port 3b formed on the upper left side surface of the inner box 3 and the exhaust port 1b formed on the upper left side surface of the outer box 1 is provided sideways.

A heating chamber fan unit 8 is disposed in the intake duct 6, and when the heating chamber fan unit 8 is driven, as shown by an arrow A in the drawing, the heating chamber fan unit 8 is placed outside the outer box 1. The air is sucked into the intake duct 6 and the wind is sent into the heating chamber 2 through the intake port 3a, so that the air in the heating chamber 2 is discharged to the outside through the exhaust duct 7. Further, a cooling fan device 9 is arranged on the right side of the bottom portion 1c of the outer case 1, and when the cooling fan device 9 is driven, as shown by an arrow B in the figure, the outer case 1 Air is sucked into the outer box 1 from the bottom inlet 1d formed in the bottom 1c, and the wind is blown to the electric parts such as the magnetron 4 and thereafter passed between the outer box 1 and the inner box 3. The air is discharged to the outside from a bottom exhaust port 1e formed on the left side of the bottom 1c of the outer box 1.

The above conventional structure has the following drawbacks. That is, when the food 10 to be cooked contained in the heating chamber 2 is cooked by the heater 5, the hot air in the heating chamber 2 is likely to escape from the exhaust duct 7 to the outside, resulting in an energy loss correspondingly and an increase in energy in the heating chamber 2. The temperature distribution becomes poor and the heating efficiency becomes poor.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a microwave oven equipped with a heater, in which the hot air in the heating chamber is less likely to escape during cooking with the heater and the heating efficiency can be improved. To provide.

[0006]

The microwave oven according to the present invention comprises:
In order to achieve the above object, an outer box having an exhaust port at the bottom, an inner box that is disposed in the outer box, has an intake port and an exhaust port, and has an inside as a heating chamber, and the inside of the heating chamber. A magnetron and a heater for heating the housed food, a fan device for a heating chamber that sends air from the intake port of the inner box into the heating chamber, and a cooling fan device for cooling electric parts including the magnetron. And an exhaust duct provided outside the inner box in a state of forming a space between the inner box and the inner surface of the outer box, the exhaust duct connecting the exhaust port of the inner box and the exhaust port of the outer box bottom. It is a feature.

In the above structure, when the heater cooking is performed, even if the hot air in the heating chamber is discharged to the exhaust duct side,
Since the hot air is not easily discharged from the exhaust port at the bottom of the outer box, the hot air in the heating chamber does not easily exit to the outside.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. Inside the outer box 11, an inner box 13 having a heating chamber 12 therein is arranged. Inner box 1
Outside of the right side of 3 is a magnetron 14 for range cooking.
Is provided, and a heater 15 for heating the heater is provided above the heating chamber 12. An intake port 16 formed on the right side surface of the outer box 11 is provided on the right side between the outer box 11 and the inner box 13.
An intake duct 18 that connects the intake port 17 formed on the upper right side surface of the inner box 13 is provided. A heating chamber fan device 19 is disposed in the intake duct 18.

On the bottom 11a of the outer box 11, a cooling fan unit 2 is provided on the right side below the magnetron 14.
0 is provided and the cooling fan device 20
A number of bottom intake ports 21 are formed around the.

On the outer side of the left side surface of the inner box 13, an exhaust duct 22 is provided so as to extend vertically. The exhaust duct 22 covers the exhaust port 23 formed in the upper part of the left side surface of the inner box 13 from the outside, and the exhaust port 23 and the exhaust port 24 formed on the left part of the bottom part 11 a of the outer box 11. Are in communication. A space 26 is formed between the outer surface of the exhaust duct 22 and the inner surface of the outer box 11 and forms a part of the cooling air passage 25 between the outer box 11 and the inner box 13. At the bottom 11a of the outer box 11, the space 2
An exhaust port 27 is also formed in a portion corresponding to 6. At the lower end of the exhaust duct 22, a U-shaped water receiving portion 28 is provided.
Are integrally formed.

At the lower part of the inner box 13, a partition plate 2 for partitioning the exhaust duct 22 side and the cooling air passage 25 side below the inner box 13 is provided.
9 are provided. Therefore, in this case, the exhaust duct 2
2 extends from the exhaust port 23 of the inner box 13 to the exhaust port 24 of the bottom 11a of the outer box 11 and is independent of the other cooling air passages 25. At the bottom of the inner box 13, an RT motor 32 for rotating a plate 31 on which the food 30 is placed is arranged.

Next, the operation of the above configuration will be described. First, in the case of performing range cooking, the cooking target 30 is placed in the heating chamber 12
The dish is placed on the inner dish 31 and the cooking start operation is performed with the door (not shown) closed. Then, the RT motor 32, the magnetron 14, the heating chamber fan device 19, and the cooling fan device 20 are energized and driven.

Of these, the cooked object 30 is rotated by energizing the RT motor 32. When the magnetron 14 is energized and driven, microwaves are supplied into the heating chamber 12, and the microwaves 3 serve to cook the food 3
0 is cooked. Further, as the heating chamber fan device 19 is energized and driven, the air outside the outer box 11 is supplied into the heating chamber 12 through the intake duct 18 as indicated by the arrow C in FIG. The air inside 12 passes through the exhaust duct 22 and the exhaust port 24 of the bottom 11 a of the outer box 11
Is discharged to the outside. Further, the cooling fan device 20
1 is energized, the air outside the outer box 11 is sucked into the outer box 11 through the bottom inlet 21 as shown by the arrow D in FIG. 1, and the air is blown onto electrical parts including the magnetron 14. Then, they are cooled and then discharged through the cooling air passage 25 from the exhaust port 27 of the bottom 11 a of the outer box 11.

On the other hand, when the heater cooking is performed, the cooking start operation is performed with the object to be cooked 30 housed in the heating chamber 12 and the door (not shown) being closed. Then, the heater 15 is energized to generate heat. The heat of the heater 15 heats and cooks the food 30. In this case, the RT motor 32, the heating chamber fan device 19 and the cooling fan device 20 are not energized.

At this time, even if the hot air in the heating chamber 12 goes out to the exhaust duct 22 side, the hot air is exhausted at the lower exhaust port 24.
Since it does not easily exit from the outside to the outside, hot air accumulates in the upper part of the exhaust duct 22, and the temperature in the heating chamber 12 and the temperature in the vicinity of the exhaust port 23 in the exhaust duct 22 become substantially the same. Therefore, since the hot air in the heating chamber 12 does not easily come out to the outside, energy loss can be reduced and the temperature distribution in the heating chamber 12 can be improved and heating efficiency can be improved as compared with the conventional case. Further, even if the temperature inside the exhaust duct 22 rises, since the space portion 26 exists outside the exhaust duct 22, the heat insulation effect of the space portion 26 can further prevent the outer case 11 from becoming hot.

Further, in the above-described embodiment, during range cooking or heater cooking, steam generated from the cooking object 30 is condensed in the exhaust duct 22 to form a water drop W (shown by a chain double-dashed line in FIG. 1). Even if it becomes, the water droplets W will be transmitted along the inner surface of the exhaust duct 22 and will be received by the water receiving portion 28 at the lower end and accumulated therein.
Can be prevented from getting dirty with water. The water stored in the water receiving portion 28 naturally evaporates.

By the way, in the conventional configuration (FIG. 3), when the steam generated from the cooking object 10 is condensed in the vicinity of the exhaust port 1b of the outer box 1 to form a water droplet W (shown by a chain double-dashed line in FIG. 3). The water droplets W may travel along the outer surface of the outer box 1 and may contaminate the installation surface of the microwave oven. In this respect, in the present embodiment, such a defect can be prevented as much as possible.

Further, since the exhaust duct 22 extends from the exhaust port 23 of the inner box 13 to the exhaust port 24 of the bottom 11a of the outer box 11 and is independent of the other cooling air passages 25, it is assumed that the heater is cooked. Even if the cooling fan device 20 is energized and the air that has passed through the cooling air passage 25 is exhausted from the exhaust port 27, the hot air in the heating chamber 12 is exhausted by being pulled by the air from the cooling fan device 20. Can be prevented.

FIG. 2 shows a second embodiment of the present invention. This second embodiment differs from the above-mentioned first embodiment in the following points. That is, the water receiving portion 33 having a container shape
Is formed as a separate member from the exhaust duct 22, and is detachably attached to the bottom portion 11 a of the outer box 11 at a portion corresponding to the lower side of the exhaust duct 22. In this case, the exhaust ports 24 and 27 of the bottom 11 a of the outer box 11 are partitioned by the water receiving portion 33. In the case of the second embodiment as described above, the water receiving portion 33 is attached to the bottom portion 11a of the outer box 11.
There is an advantage that the water accumulated in the water receiving portion 33 can be easily discharged by removing the water.

The present invention is not limited to the above-described embodiment, and for example, the exhaust duct 22 may be provided on the back surface of the inner box 13, and the air is sent into the heating chamber 12 by the cooling fan device. It may be configured. Furthermore, intake port 1
7, a damper may be attached, and the intake port 17 may be closed by the damper when the heater is cooked so that the wind does not enter the heating chamber 12. .

[0021]

According to the microwave oven of the present invention, even if the hot air in the heating chamber is discharged to the exhaust duct side during cooking with the heater, the hot air is easily discharged from the exhaust port at the bottom of the outer box. Since it is not discharged, it is possible to prevent hot air in the heating chamber from escaping,
The heating efficiency can be improved.

According to the microwave oven of the third aspect, even if dew condensation occurs in the exhaust duct, the water drop can be received and stored in the water receiving portion to prevent the installation surface of the microwave oven from being soiled. . According to the microwave oven of the fourth aspect, even if the wind passes through the cooling air passage during the cooking with the heater, it is possible to prevent the hot air in the heating chamber from being exhausted from the exhaust duct by being pulled by the wind. .

[Brief description of drawings]

FIG. 1 is a longitudinal sectional front view showing a first embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional front view of a main part showing a second embodiment of the present invention.

FIG. 3 is a diagram corresponding to FIG. 1 showing a conventional configuration.

[Explanation of symbols]

11 is an outer box, 11a is a bottom part, 12 is a heating chamber, 13 is an inner box, 14 is a magnetron, 15 is a heater, 17 is an intake port, 19 is a heating chamber fan device, 20 is a cooling fan device, and 22 is exhaust. Ducts, 23 and 24 are exhaust ports, 25 is a cooling air passage, 26 is a space part, 27 is an exhaust port, 28 is a water receiving part, 30 is an article to be cooked, and 33 is a water receiving part.

Claims (4)

[Claims] 1. An outer box having an exhaust port at the bottom, an inner box disposed inside the outer box, having an intake port and an exhaust port, and having an interior as a heating chamber, and an enclosure housed in the heating chamber. A magnetron and a heater for heating the food, a fan device for the heating chamber that sends air from the intake port of the inner box into the heating chamber, a cooling fan device for cooling the electric parts including the magnetron, and the inner box. An electronic device, characterized in that the electronic device is provided with an exhaust duct that is provided on the outside of the container in a state that a space is formed between the exhaust port of the internal box and the internal surface of the external box, and that connects the exhaust port of the internal box and the exhaust port of the external box bottom. range. 2. The microwave oven according to claim 1, wherein the exhaust duct is provided on a side surface of the inner box. 3. The microwave oven according to claim 1, wherein the exhaust duct is provided with a water receiver. 4. The electronic device according to claim 1, wherein the exhaust duct extends from the exhaust port of the inner box to the exhaust port of the bottom of the outer box and is independent of other cooling air passages. range.