JP2001311519A - Heating cooking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the number of part items and lower the cost of a heating cooking device in which wind generated by a cooling fan is guided to a heating chamber from an inlet port on the ceiling part of the heating chamber. SOLUTION: A duct 24 for guiding the air generated by the cooling fan 16 which passes through a magnetron 13 from an air guide duct 18 to the front side of the upper surface of a ceiling plate 3e of an inner box 3 (the ceiling part of the heating chamber) is composed of the ceiling plate 3e, a protruding part 20 provided in the ceiling plate 3e and serving as the reflecting plate of a heater 19 and a heat shield plate disposed in the upper part of the ceiling plate 3e. Thus, an exclusive intake duct does not need to be separately provided, so that the number of parts can be reduced and the cost can be lowered, which is different from a case where an exclusive intake duct is provided on the upper surface of the ceiling part of the heating chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating cooker having a configuration in which air from a cooling fan for cooling electric components such as a magnetron is guided into a heating chamber from a ceiling air inlet of the heating chamber.

[0002]

For example, in a microwave oven having an oven function, wind generated by a cooling fan for cooling electric components such as a magnetron is blown onto a side wall of a heating room on the machine room side. In addition to providing a ventilation duct for guiding to the upper surface side, an intake duct communicating with the ventilation duct is provided on the upper surface of the ceiling of the heating room, and a ceiling intake port is provided in front of the ceiling of the heating room. There is a configuration in which wind from a cooling fan that cools electric components such as a magnetron is guided from the ceiling inlet to the inside of the heating chamber through the air guide duct and the intake duct. In this case, a heater for oven cooking is provided on the lower surface of the ceiling of the heating chamber, and the heat of the heater is prevented from being transmitted to the outer cover between the ceiling of the heating chamber and the ceiling of the outer cover. A heat shield plate is provided.

[0003] In such a configuration, the wind generated by the cooling fan is guided from the ceiling intake port of the heating chamber to the front portion of the heating chamber, so that the door is clouded by steam generated from the object to be cooked. This has the effect that it can be prevented.

[0004] However, in the configuration described above,
Since a dedicated intake duct is provided on the upper surface side of the ceiling of the heating chamber, there are drawbacks in that the number of parts increases and the cost increases accordingly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a structure in which wind from a cooling fan is guided from a ceiling intake port of a heating chamber into the heating chamber. It is another object of the present invention to provide a heating cooker that can reduce the cost and reduce the cost.

[0006]

In order to achieve the above object, the invention according to claim 1 is provided inside an outer cover,
A heating chamber for accommodating an object to be cooked therein, a door for opening and closing a front opening of the heating chamber, and a magnetron for supplying microwaves to the heating chamber to heat and cook the object accommodated in the heating chamber A cooling fan provided to cool electric components such as the magnetron; a wind guide duct provided to guide wind from the cooling fan to an upper surface side of a ceiling of the heating chamber; and A heater disposed on the lower surface of the ceiling of the heater for heating and cooking an object contained in the heating chamber; and blocking heat from being transmitted to the outer cover side above the ceiling of the heating chamber. The heat shield plate provided as described above, is provided so as to protrude toward the other side at one of the heat shield plate and the ceiling portion of the heating chamber, together with these heat shield plate and the ceiling portion of the heating chamber, Heating the wind from the air duct A convex portion that forms an air passage leading to the front side of the upper surface of the ceiling portion, and a ceiling portion that is provided at the front of the ceiling portion of the heating chamber and guides the wind passing through the air passage to the inside of the heating chamber. And an intake port.

According to the above-described means, the ventilation passage for guiding the wind from the cooling fan from the air guide duct to the front side of the upper surface of the ceiling of the heating chamber is provided with the ceiling of the heating chamber and the shielding provided above the ceiling. Since it is configured to be formed by a hot plate and a convex portion provided on one of the ceiling portion and the heat shield plate of these heating rooms, a case where a dedicated intake duct is provided on the upper surface side of the ceiling portion of the heating room. On the contrary, it is not necessary to separately provide a dedicated intake duct, so that the number of parts can be reduced and the cost can be reduced.

In this case, it is preferable that the projection is provided on a ceiling of the heating chamber and also serves as a reflector of the heater. According to this, the configuration can be simplified as compared with a case where a dedicated convex portion is provided to form a ventilation path.

Further, it is preferable that the heat shield plate is provided with a downwardly inclined portion at the front of the heat shield plate. According to this, the wind supplied into the heating chamber from the ventilation path through the ceiling inlet of the heating chamber flows along the inclined portion, so that the wind easily flows along the inner surface of the door, and Fogging can be better prevented.

A fourth aspect of the present invention is characterized in that a cooling fan is operated during heating cooking by a heater. When the cooling fan is not operated, there is a possibility that steam or the like generated from the cooking object in the heating chamber flows from the ceiling intake port of the heating chamber to the ventilation path and the ventilation duct side, that is, the so-called reverse flow. By doing so, it is possible to prevent the backflow from occurring.

A fifth aspect of the present invention is characterized in that an interior light for illuminating the inside of the heating chamber is arranged in a ventilation path. According to this, the wind that passes through the ventilation path also hits the interior light, so that the interior light can be cooled and vapor can be prevented from adhering to the interior light.

The invention according to claim 6 is characterized in that the ceiling intake port is formed such that the opening area on the side close to the air guide duct is larger than that on the side far from the air guide duct. The wind that has flowed into the ventilation path from the air guide duct tends to easily enter the heating chamber from the ceiling air inlet farther from the air guide duct than the ceiling air inlet closer to the air guide duct. Therefore, as in the present invention, the ceiling intake port is formed such that the opening area on the side close to the air guide duct is larger than that on the side far from the air guide duct, so that the air inlet on the side close to the air guide duct is formed. A uniform amount of wind is introduced as much as possible from the ceiling intake port and the ceiling intake port far from the wind guide duct.

[0013] The invention of claim 7 is characterized in that the interior lamp for illuminating the inside of the heating chamber is disposed in a portion of the ventilation path where the opening area of the ceiling intake port is large. According to this, the wind can be satisfactorily applied to the interior lamp, and the interior of the heating chamber can be satisfactorily illuminated by the light emitted from the interior lamp through the ceiling intake port.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a microwave oven with an oven function will be described below with reference to the drawings.

First, in FIG. 2 showing the overall appearance, the main body 1 of the microwave oven as a heating cooker has a rectangular box shape with an open front surface inside an outer cover 2 having a rectangular box shape elongated in the lateral direction. An inner box 3 is provided, and the inside of the inner box 3 is a heating chamber 4. 1 and FIGS. 3 to
As shown in FIG. 5, the space on the right side of the inner box 3 is
And A door 7 that opens and closes a front opening 6 of the heating chamber 4 is provided on the front surface of the main body 1 so as to be rotatable in the vertical direction.
Is provided. The operation panel 8 includes a plurality of keys 9
And a display unit 10 are provided. In this case, the inner box 3 forming the heating chamber 4 includes a bottom plate 3a, left and right side plates 3b,
3c and the rear plate 3d are formed of an aluminum-plated steel plate,
Only the ceiling plate 3e is formed of a stainless steel plate.

A turntable 11 rotated by a turntable drive motor (not shown) is provided at the bottom of the heating chamber 4, and a turntable (not shown) is removably mounted on the turntable 11. It has become. On the left and right side plates 3b and 3c of the inner box 3 (heating chamber 4), a dish receiving portion 12 for placing a rectangular oven dish (not shown) for oven cooking is provided. Also, the right side plate 3 of the inner box 3 on the machine room 5 side.
c, a magnetron 1 for supplying microwaves into the heating chamber 4 to heat the food housed in the heating chamber 4
3 and a waveguide 14 are provided. In the machine room 5,
In addition to the magnetron 13, the electric parts 15 of the inverter circuit
(See FIG. 3) and the like, and a cooling fan 16 for cooling these heat-generating electric components is provided. The cooling fan 16 includes a blower blade 16a and a fan motor 16b that drives the blower blade 16a to rotate.

An air guide duct 18 is provided on the front side of the magnetron 13. This air duct 18
It extends upward and opens at the upper surface of the ceiling plate 3e of the inner box 3 constituting the ceiling of the heating chamber 4 (see FIG. 5),
The configuration is such that the wind generated by the cooling fan 16 after passing through the magnetron 13 is guided to the upper surface side of the ceiling of the heating chamber 4.

On the lower surface side of the ceiling plate 3e of the inner box 3, a bar-shaped heater 19 for oven cooking is provided. The heater 19 is formed in a rectangular frame shape corresponding to the planar shape of the heating chamber 4 (see FIG. 1), and an end 19a for power supply connection is directed to the machine chamber 5 side. On the ceiling plate 3e of the inner box 3, a convex portion 20 bulging upward is integrally formed by drawing (see FIGS. 1, 5 and 6). The convex portion 20 is formed in a rectangular shape large enough to accommodate the heater 19, and has a configuration also serving as a reflecting plate portion of the heater 19. Although not shown, a lower heater composed of a planar heater is also provided on the lower surface of the bottom plate 3a of the inner box 3.

At the front of the ceiling plate 3e of the inner box 3, as shown in FIG. 1, a ceiling intake port 21 having a large number of punching holes 21a is formed. As shown in FIG. 1, the ceiling intake port 21 is formed such that the opening area on the right side near the air guide duct 18 is larger than that on the left side far from the air guide duct 1. On the upper surface side of the front part of the ceiling plate 3 e of the inner box 3, an interior light 22 is disposed on the right side where the opening area of the ceiling intake port 21 is large. When the interior light 22 is turned on, the light causes the ceiling air intake 21
The interior of the heating chamber 4 is illuminated through the (punching holes 21a).

Above the ceiling plate 3e of the inner box 3, a heat shield plate 23 for blocking the heat of the heater 19 from being transmitted to the outer cover 2 is provided so as to cover the ceiling plate 3e. (See FIGS. 3 to 6). The heat shield plate 23, the ceiling plate 3e of the inner box 3 (the ceiling of the heating chamber 4), and the ceiling plate 3e
The convex portion 20 forms a ventilation path 24 (see FIGS. 1 and 6) communicating with the upper portion of the air guide duct 18 and the ceiling intake port 21. The heat shield plate 23 is integrally formed with a bulging portion 25 bulging upward at a connection portion with the air guide duct 18 by drawing (see FIGS. 4 to 6). The bulging portion 25 is formed with a curved portion 25a for facilitating the flow of the wind from the wind guide duct 18 to the front side. At the front of the heat shield plate 23, a forwardly inclined portion 26 (see FIGS. 3 and 6) is formed over the width direction of the heat shield plate 23.

In FIG. 6, the right side plate 3c of the inner box 3 is shown.
Is located at a position corresponding to the waveguide 14,
The excitation port 27 is provided with a mica cover 28. Also, the ceiling plate 3 of the inner box 3
e, an exhaust port 29 (see FIGS. 1, 3 and 4)
Are formed facing backwards. Further, although not shown, a control circuit including a microcomputer is provided on the back side of the operation panel 8.
The magnetron 13, the cooling fan 16, the heater 1
9, the lower heater, the display unit 10, the interior lamp 22, and the like are controlled.

Next, the operation of the above configuration will be described. When performing range cooking, a rotating plate (not shown) is placed on the turntable 11 in the heating chamber 4, an object to be cooked is placed on the rotating plate, and the operation is performed with the door 7 closed. A range cooking instruction is issued by operating the key 9 on the panel 8. Based on this instruction, the turntable 11 and the turntable are rotated by the turntable drive motor, and the magnetron 13 is oscillated. Microwaves oscillated from the magnetron 13 pass through the waveguide 14 and pass through the excitation port 27. From the heating chamber 4 and the microwaves heat the object to be cooked on the rotating plate.

At this time, the fan motor 16b of the cooling fan 16 is energized, and the fan motor 16b is rotated at a rotation speed of, for example, 2800 rpm. By the blowing action of the cooling fan 16, air outside the main body 1 is sucked into the machine room 5 (see the arrow A <b> 1 in FIGS. 1 and 3), a part of which cools the magnetron 13, and , And is supplied to the ventilation passage 24 on the upper surface of the ceiling portion 3e of the inner box 3 (see the arrow A2 in FIGS. 1, 3 and 5), and the remaining air cools the electric parts 15 and the like of the inverter circuit. Is discharged to the outside of the outer cover 2 (arrow A3 in FIG. 3).
reference).

The air supplied into the ventilation passage 24 flows through the ventilation passage 24 and is supplied into the heating chamber 4 from the ceiling inlet 21 (see the arrow A4 in FIGS. 1 and 6). At this time, since the forwardly inclined portion 26 is formed at the front of the heat shield plate 23, the wind supplied from the ventilation passage 24 into the heating chamber 4 through the ceiling intake port 21 flows through the inclined portion 26. Will flow along. In addition, the interior light 22 is cooled by the wind flowing through the ventilation path 24. As the air is supplied into the heating chamber 4, the air in the heating chamber 4 is discharged from the rear exhaust port 29 to the outside of the main body 1.

On the other hand, when performing oven cooking, an oven dish (not shown) on which an object to be cooked is placed is set in the dish receiving portion 12 in the heating chamber 4 and the operation panel 8 is closed with the door 7 closed. Is operated by operating the key 9.
Based on this instruction, the heater 19 and the lower heater are energized to generate heat, and the heat cooks the food on the oven plate.

At this time, the fan motor 16b of the cooling fan 16 is also energized.
It is not necessary to cool the fan motor 16b
Is rotated at a lower rotation speed than that of the range cooking, for example, at a rotation speed of 1400 rpm by the phase control. By the blowing action of the cooling fan 16, the air outside the main body 1 is sucked into the machine room 5 (see arrow A 1), and a part of the air passes through the magnetron 13, as in the case of the range cooking described above. The air passes through the air duct 18 and is supplied to the ventilation path 24 on the upper surface of the ceiling 3e of the inner box 3 (see arrow A2),
The remaining air is discharged to the outside of the outer cover 2 after cooling the electric components 15 and the like of the inverter circuit (see arrow A3). The air supplied into the ventilation path 24 flows through the ventilation path 24 and is supplied into the heating chamber 4 from the ceiling intake port 21 (see arrow A4).

According to the above-described embodiment, the following effects can be obtained. First, the air from the cooling fan 16 that has passed through the magnetron 13 is passed from the air guide duct 18 to the inner box 3.
The ventilation path 24 leading to the front side of the upper surface of the ceiling plate 3e is connected to the ceiling plate 3e of the inner box 3 constituting the ceiling of the heating chamber 4, the heat shield plate 23 disposed above the ceiling plate 3e, and the inner box 3 Is different from the case where a dedicated air intake duct is provided on the upper surface side of the ceiling of the heating chamber 4, it is necessary to separately provide a dedicated air intake duct. In addition, the number of parts can be reduced and the cost can be reduced accordingly.

In this case, since the convex portion 20 is provided on the ceiling plate 3 e of the inner box 3 (the ceiling portion of the heating chamber 4) and serves also as the reflecting plate portion of the heater 19, the ventilation passage 24 is formed. Therefore, the configuration can be simplified as compared with the case where a dedicated convex portion is provided.

Further, by providing the forwardly inclined portion 26 at the front of the heat shield plate 23, the air supplied into the heating chamber 4 from the ventilation passage 24 through the ceiling intake port 21 is supplied to the inclined portion 26. , The wind easily flows along the inner surface of the door 7, and the door 7 can be satisfactorily prevented from fogging with water vapor generated from the food. At this time, the wind supplied into the heating chamber 4 at the time of microwave cooking is warm air after the magnetron 13 has been cooled, so that the fogging of the door 7 can be more effectively prevented.

Here, the wind flowing from the air guide duct 18 to the air passage 24 is heated from the ceiling air inlet 21 farther from the air guide duct 18 than the ceiling air inlet 21 closer to the air guide duct 18. There is a tendency to easily enter the room 4. Therefore,
As in the present embodiment, the ceiling intake port 21 is
8 is formed so that the opening area on the side closer to 8 (the right side in FIG. 1) is larger than the side farther from the air guide duct 21 (the left side in FIG. 1). A uniform amount of wind can enter as much as possible from the intake port 21 and the ceiling intake port 21 farther from the air guide duct 18.

Further, an interior light 22 for illuminating the inside of the heating chamber 4
Is disposed in the ventilation path 24, so that the wind passing through the ventilation path 24 also hits the interior light 22. The wind can cool the interior light 22 and vapor adheres to the interior light 22. Can be prevented. At this time, the interior light 2
2 is located at the right side of the ventilation path 24 where the opening area of the ceiling intake port 21 is large,
The wind can be satisfactorily applied to the interior light 22, and the inside of the heating chamber 4 can be satisfactorily illuminated through the ceiling intake port 21 by the light emitted from the interior light 22.

Further, the heat shield plate 23 is provided with the air guide duct 18.
A bulging portion 25 that bulges upward is formed at a connection portion with the air passage, so that wind can easily flow into the ventilation passage 24 from the ventilation duct 18 and a ventilation amount can be secured. Further, since the curved portion 25 a is formed in the bulging portion 23, the wind from the wind guide duct 18 can easily flow to the front side of the air passage 24.

On the other hand, the cooling fan 16 does not need to cool the magnetron 13 during oven cooking.
It is designed to operate at a lower rotation speed than during microwave cooking. In this case, too, the air from the cooling fan 16 is supplied into the heating chamber 4 through the ventilation path 24 in the same manner as in the case of the range cooking. It is possible to prevent backflow to the side, and eventually to the machine room 5 side, and to cool the interior lamp 22. Incidentally, if the air containing moisture in the heating chamber 4 flows toward the machine room 5, it may cause a failure of the electric components 16 disposed in the machine room 5.

In the above-described embodiment, the ceiling plate 3e of the inner box 3 constituting the ceiling of the heating chamber 4 is formed of a stainless steel plate. Since the ceiling intake port 21 formed of a punching hole also serving as the light opening is formed, it is not necessary to apply a coating for preventing rust to the ceiling intake port 21 portion. Incidentally, in the case where an intake port comprising a punched hole is formed in the right side plate 3c of the inner box 3 made of an aluminum-plated steel plate, it is necessary to apply a coating for preventing rust to the intake port portion. In the embodiment, since it is not necessary to apply a coating for preventing rust, the cost can be reduced accordingly.

[0035]

As is apparent from the above description, according to the heating cooker of the present invention, the ventilation passage for guiding the air from the cooling fan from the air guide duct to the front side of the upper surface of the ceiling of the heating chamber is heated. Since it is configured to be formed by the ceiling part of the room, the heat shield plate disposed above the room, and the projection provided on one of the ceiling part and the heat shield plate of these heating chambers, Unlike the case where a dedicated intake duct is provided on the upper surface side of the ceiling, there is no need to separately provide a dedicated intake duct, and the number of parts can be reduced and the cost can be reduced accordingly.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is a plan view with an outer cover and a heat shield plate removed.

FIG. 2 is an overall perspective view showing a state where a door is opened.

FIG. 3 is a right side view with the outer cover removed.

FIG. 4 is a plan view with the outer cover removed.

FIG. 5 is a sectional view of a main part along a line BB in FIG. 4;

FIG. 6 is a sectional view of a main part at a portion corresponding to line CC in FIG. 4;

[Explanation of symbols]

In the drawing, 1 is a main body, 2 is an outer cover, 3 is an inner box, 3e is a ceiling plate (the ceiling of a heating room), 4 is a heating room, 5 is a machine room, 6
Is a front opening, 7 is a door, 13 is a magnetron (electric part), 15 is an electric part, 16 is a cooling fan, 18 is a ventilation duct, 19 is a heater, 20 is a convex part, 22 is an interior light, 2
Reference numeral 3 denotes a heat shield plate, 24 denotes a ventilation path, and 26 denotes an inclined portion.

Claims (7)

[Claims] 1. A heating chamber provided inside an outer cover and accommodating an object to be cooked therein, a door for opening and closing a front opening of the heating chamber, and a microwave supplied into the heating chamber to perform the heating. A magnetron that heats and cooks the food housed in the room, a cooling fan that is provided to cool electric components such as the magnetron, and guides wind from the cooling fan to the upper surface side of the ceiling of the heating chamber. And a heater disposed on the lower surface of the ceiling of the heating chamber for heating and cooking the food contained in the heating chamber; and the heater above the ceiling of the heating chamber. A heat shield plate provided to block the transmission of heat to the outer cover side; and a heat shield plate provided on one of the heat shield plate and the ceiling of the heating chamber so as to project toward the other side. , These heat shields and the heating room Together with a convex portion that forms a ventilation path for guiding the wind from the air guide duct to the front side of the upper surface of the ceiling of the heating chamber, provided at the front of the ceiling of the heating chamber, A heating cooker, comprising: a ceiling air inlet for guiding the passed air into the heating chamber. 2. The heating cooker according to claim 1, wherein the projection is provided on a ceiling of the heating chamber and also serves as a reflector of the heater. 3. The heating cooker according to claim 1, wherein a forwardly inclined portion is provided at a front portion of the heat shield plate. 4. The cooking device according to claim 1, wherein a cooling fan is operated during cooking by the heater. 5. The cooking device according to claim 1, wherein an interior light for illuminating the inside of the heating chamber is arranged in the ventilation path. 6. The heating device according to claim 1, wherein the ceiling intake port is formed such that an opening area on a side near the air guide duct is larger than that on a side far from the air guide duct. Cooking device. 7. The cooking device according to claim 6, wherein the interior light for illuminating the inside of the heating chamber is disposed in a portion of the ventilation path where the opening area of the ceiling intake port is large.