JPH06313558A - Microwave oven - Google Patents

Abstract

PURPOSE:To control the amount of heat generation of a motor-driven fan, and cool effectively a magnetron and electrical equipment components by driving an axial fan without applying overload to the motor-driven fan. CONSTITUTION:This microwave oven incorporates a device that cools a magnetron 31 and an electronic equipment component 32. A motor-driven fan 33 cools the magnetron 31 housed in an air duct 34. A drive fan 51 is rotated by an air current passing in the air duct 34 and an axial fan is also rotated, interlocking with the drive of the fan 51. The axial fan 52 blows air, thereby cooling the electrical equipment component 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave oven, and more particularly to a microwave oven having a high frequency oscillator and a device for cooling electrical components, which become hot during operation of the microwave oven. .

[0002]

2. Description of the Related Art Generally, during operation of a microwave oven, electric components such as a magnetron (high-frequency oscillator) and a high-voltage transformer connected to the magnetron are heated to a high temperature and must be cooled. Conventionally, in order to cool them, a microwave oven has a built-in device for cooling with air using a blower fan, a propeller fan, or the like.

A conventional cooling device is shown in FIG. 5 and FIG.
Briefly explained. FIG. 5 is a schematic cross-sectional side view of a conventional microwave oven.
A storage chamber 3 in which electric components 2 such as a magnetron M and a high-voltage transformer are stored is partitioned, and an upper plate 3 of the storage chamber 3 is defined.
The magnetron M is attached to a, and the electrical component 2 such as a high voltage transformer is installed on the lower plate 3c.

The cooling device for the electric components 2 such as the magnetron M of the microwave oven and the high-voltage transformer is mounted on the rear plate 3b of the storage chamber 3 and driven by a single motor. The electric fan 5 drives the rear plate 3b. Also, the outside air is taken in through the intake ports 3d and 3e provided in the lower plate 3c, and the air is blown onto the magnetron M and the electric component 2 to cool them. An air duct 4 is attached to the upper plate 3a so as to have an opening 4a toward the electric fan 5 and to cover the anode part Ma of the magnetron M which becomes hot during operation. The sucked air is guided to the air duct 4 and the magnetron M
The anode part Ma is effectively cooled. The arrows in the figure show the flow of the sucked air.

The air duct 4 is connected to the heating chamber of the microwave oven, and the air heated by cooling the magnetron M is discharged to the heating chamber. An exhaust port 3f is provided in the lower plate 3c of the storage chamber 3 so that the air that has cooled the electrical component 2 can be exhausted to the outside. However, in the cooling device having the above-described configuration, it is difficult to effectively cool both the magnetron M attached to the upper plate 3a of the storage chamber 3 and the electrical component 2 attached to the lower plate 3c. That is, if the electric fan 5 is attached to the upper side of the rear plate 3b in order to effectively cool the magnetron M, the electric component 2, particularly the lower part of the electric component 2, is not effectively cooled. On the contrary, the electric fan 5 is connected to the rear plate 3b.
If the electric component 2 is effectively cooled, the magnetron M will be insufficiently cooled if it is mounted on the lower side of the.

To solve this problem, it is possible to design the mounting position and output of the electric fan 5 optimally, but if this is done, the mounting position of the electric fan 5 will be very limited.
The degree of freedom in design becomes extremely narrow. Further, if the output of the electric fan 5 is increased in order to effectively cool both the magnetron M and the electrical component 2, the motor becomes large and heavy, which causes many design inconveniences. Furthermore, by using two sets of electric fans 5, the magnetron M and the electrical components 2
Although it may be possible to separately cool and, it is difficult to put them into practical use due to weight and cost problems.

Considering the above problems, it is conceivable to make an improvement as shown in FIG. That is, the centrifugal fan 5a is provided coaxially with the shaft of the electric fan 5, and the outlet of the centrifugal fan 5a is connected to the opening 4a of the air duct 4. If the shaft of the electric fan 5 is installed along the vertical direction, both the magnetron M and the electric component 2 can be effectively cooled.

[0008]

However, if two fans are driven by a single motor as described above, the load on the motor increases and the amount of heat generated by the motor itself increases. Therefore, the intake port 3 of the storage chamber 3
The outside air sucked from d d is heated by the motor and then blown onto the magnetron M and the electrical component 2. Moreover, recently, the output of a magnetron used in a microwave oven tends to be large, and the amount of heat generated in the storage chamber 3 is also increasing.
The load on the motor is further increased to cool it, and in some cases, a device for cooling the motor may be required.

Therefore, an object of the present invention is to provide a microwave oven having a built-in device capable of effectively cooling high-frequency oscillators such as magnetrons and high-voltage transformers and other electrical components without increasing the amount of heat generated by the motor. .

[0010]

In a microwave oven according to the present invention, a heating chamber for heating food and a storage chamber for storing a high frequency oscillator and electrical components are partitioned in a casing,
The storage chamber is provided with an air duct that communicates between the storage chamber and the heating chamber in a state where a part or all of the high-frequency oscillator is stored therein, and the air is drawn by the cooling electric fan provided in the storage chamber. A cooling device that cools the electrical components by the generated outside air, guides the sucked outside air into the air duct, cools the high-frequency oscillator by the outside air passing through the air duct, and then exhausts the outside air to the heating chamber. In the microwave oven, the cooling device is provided with a blowing unit that is driven by an air flow in the air duct to effectively cool the electric component.

[0011]

According to the microwave oven of the present invention, the outside air is taken in by the cooling electric fan provided in the storage chamber, and the electric components are cooled by the taken outside air. Also,
The outside air is guided to an air duct that houses a part or all of the high-frequency oscillator and is exhausted to the heating chamber.
The high-frequency oscillator is effectively cooled by the outside air passing through the air duct. Furthermore, the air blower can blow the air to the electric component, and the electric component can be effectively cooled. Moreover, since the air blower is driven by utilizing the air flow in the air duct, the motor of the electric cooling fan is not loaded when the air blower is driven.

[0012]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 1 is a schematic sectional side view of a microwave oven according to an embodiment of the present invention. Further, FIG. 2 is a diagram showing a main part of a schematic sectional plan view of the microwave oven. Referring to FIG. 1 and FIG. 2, this microwave oven accommodates a casing 10, a cooking chamber 20 that is partitioned by a partition plate S in the casing 10 for cooking food, and electrical components. The storage chamber 30 is included. A door 21 is provided on the front surface of the cooking chamber 20 so that food can be taken in and out. Further, reference numeral 11 denotes an operation panel provided with operation switches and the like, and by operating the operation switches, heating and cooking suitable for the food to be cooked can be performed.

The casing 10 is in the form of a metal box, and the rear plate 12 is provided with a number of intake holes 12a communicating with the storage chamber 30, and the bottom plate 13 is also communicated with the storage chamber 30. Small holes 13a and 13b are provided. The storage chamber 30 stores a magnetron 31, which is a high-frequency oscillator, an electrical component 32 including a high-voltage transformer connected to the magnetron 31, and a cooling device for cooling them. The cooling device includes an electric cooling fan 33, an air duct 34, and a blower B.

The electric cooling fan 33 is a motor 33a and an axial fan 33 connected to the rotating shaft of the motor 33a.
When the motor 33 rotates, it blows air in the axial direction. The electric fan 33 is attached to the rear plate 12 of the casing 10 with the axial direction of the fan 33b extending along the front-rear direction of the microwave oven.

The air duct 34 is a tubular member having a rectangular cross section having an air inlet 34a and an outlet 34b, and is a substantially V-shaped member that is bent in the middle. The air duct 34 is attached to the upper plate 30a of the storage chamber 30,
The air inlet 34a faces the fan 33b of the cooling electric fan 33, and the outlet 34b communicates with the cooking chamber 20. A cutout 34c is provided at a predetermined position on the wall surface of the air duct 34. An air guide member 34d is attached to the peripheral edge of the opening of the air inlet 34a so that the air blown to the air inlet 34a can satisfactorily flow into the air duct 34.
The shape of the air duct 34 may be U-shaped or the like instead of being tubular with a rectangular cross section.

The magnetron 31 is a high-frequency oscillation source, and the microwave oscillated from the magnetron 31 is
It is radiated to the cooking chamber 20 through the waveguide P. Further, the magnetron 31 has a bottom portion 34e of the air duct 34.
Through the air duct 34 from the upper plate 3 of the storage chamber 30
It is attached to 0a. In this case, the magnetron 31 is in a state where the anode part 31 a is housed in the air duct 34. In addition, magnetron 3
The entire unit 1 may be housed in the air duct 34. The electrical component 32 is attached to the lower plate 30b of the storage chamber 30.

The blower means B uses the airflow in the air duct 34 to rotate the fan, whereby the storage chamber 3
The electric component 32 in 0 is blown with air to cool it. This blower B has a central axis 53 and a central axis 53.
Has a drive fan 51 integrally attached to a predetermined position thereof, and an axial fan 52 integrally attached to one end portion 53a of the central shaft 53. The drive fan 51 and the axial fan 52 are interlocked with each other. Rotate. The drive fan 51 has a water wheel shape, and rotary vanes made of four rectangular flat plates are symmetrically attached in the vertical direction and around the central axis 53.
The number of rotary wings is not limited to four and can be set appropriately. The other end 53b of the central shaft 53 is attached to the upper plate 30a of the storage chamber 30 by a mounting member 54, and the other end 53b of the central shaft 34 is attached to the upper plate 30a of the storage chamber 30. It is freely rotatable. That is, the air blower B is attached in a state of being suspended from the upper plate 30a of the storage chamber 30. Then, the rotary vanes of the drive fan 51 are arranged such that the air duct 34 is rotated at a predetermined rotation position.
The notch 34c enters into the air duct 34, that is, the rotary vane moves into and out of the air duct 34 as it rotates.

According to this embodiment, the magnetron 31 and the electrical components 32, which have become hot during the operation of the microwave oven, are cooled as follows. When power is supplied to the motor 33a of the cooling electric fan 33, the axial fan 33b is rotated, and the small holes provided in the intake holes 12a provided in the rear plate 12 of the casing 10 and the bottom plate 30b of the storage chamber 30. Outside air is sucked from 13a, flows into the air duct 34 from the air inlet 34a of the air duct 34, and is blown to the electrical component 32. As a result, the electrical component 32 is cooled by the outside air. Further, since the anode part 31a of the magnetron 31 which becomes hot during operation is housed in the air duct 34, the magnetron 31 is effectively cooled by the outside air flowing into the air duct 34.

Air duct 3 passing through the magnetron 31
The air in 4 is exhausted to the cooking chamber 20, but before the passage to the cooking chamber 20, the rotary vanes of the driving fan 51 of the blower unit B are inwardly cut out from the cutout 34c provided in the wall surface of the air duct 34. Air duct 3 because it is entering
A force is applied to the rotary vane by the air flow inside the drive fan 4, and the drive fan 51 rotates. Then, the axial fan 52 rotates in association with the rotation of the drive fan 51, and blows air to the electrical component 32 mounted on the bottom plate 30b of the storage chamber 30 to further cool the electrical component 32.

As described above, in this embodiment, since the force of the air flow in the air duct 34 is used as the drive source of the blower B, the motor 33a of the cooling electric fan 33 is electrically connected to the electric component 3.
No additional load is applied to further cool 2. Therefore, the electric component 32 can be effectively cooled by using the motor having the same output as the conventional one without increasing the heat generation amount of the motor 33a.

Since the air blown by the air blowing means B is discharged to the outside from the small holes 13b provided in the bottom plate 30b of the storage chamber 30, the air passage shown by the arrow in the storage chamber 30 is formed. It is formed and good cooling can be performed. The present invention is not limited to the above embodiment, and the electric fan for cooling may be the electric fan BF having the structure shown in FIGS. 3 and 4. Figure 3
FIG. 4 is a front view of this electric fan BF, and FIG. 4 is a right side view of a partial cross section. That is, this electric fan BM is
The casing 70, a blower motor 80 attached to the casing 70, and a blower fan 90 driven by the motor 80 are configured.

The casing 70 has a substantially rectangular parallelepiped shape with an open rear surface, an air outlet 71 is provided on the front surface, and the casing 70 has predetermined positions at the upper rear edge and the lower rear edge. A claw portion 73 is formed on the.
The one side surface 70 a of the casing 70 has a casing 70.
Is inclined outward from the front surface to the rear surface, and the side surface 70a is provided with a hole 74 through which an electric wire or the like is inserted. A ring-shaped blower frame 72 is attached to the air outlet 71 in a state of protruding outward to rectify the blown air. Further, inside the casing 70, a motor mounting portion 76 for mounting the blower motor 80 is formed.

The blower motor 80 is attached to the motor mounting portion 76 so that its rotation shaft is located at the center of the air outlet 71 provided on the front surface of the casing 70. The rotation shaft of the blower motor 80 is Blower fan 9
0s are connected. The blower fan 90 is an axial fan, and sucks air from the rear of the casing 70 and blows it out forward by the rotation of the blower motor 80.

In order to mount the electric fan BF having the above-mentioned structure in the storage chamber 30 of the microwave oven, a groove is formed in the rear plate 12 of the microwave oven, and the casing 7 of the fan BF is installed.
The claw portion 73 formed in 0 and this groove are engaged. Further, the casing 70 and the rear plate 12 of the microwave oven are screwed together
If it is fastened using 5, etc., it is possible to prevent the electric fan BF from coming off due to vibration of the blower motor 80 or the like.

In addition, various design changes can be made without changing the gist of the present invention.

[0026]

According to the present invention, the electric components are cooled by the outside air drawn by the cooling electric fan, and the high frequency oscillator is effectively cooled by the outside air sent to the air duct. Furthermore, the air blower driven by the air flow in the air duct can blow the air to the electric component to effectively cool the electric component.

Therefore, it is possible to effectively cool the electric components without overloading the motor of the electric cooling fan. That is, the high-frequency oscillator can be effectively cooled, and the electrical components can be effectively cooled without increasing the heat generation amount of the motor.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a storage chamber in a microwave oven according to an embodiment of the present invention.

FIG. 2 is a main part of an I-arrow view in FIG.

FIG. 3 is a front view of an electric cooling fan according to a modification.

FIG. 4 is a right side view of the cooling electric fan of FIG.

FIG. 5 is a cross-sectional view showing a schematic configuration of a storage chamber in a conventional microwave oven.

FIG. 6 is a cross-sectional view showing a schematic configuration of a storage chamber in a conventional microwave oven.

[Explanation of symbols]

 10 Casing 20 Cooking Room 30 Storage Room 31 Magnetron (High Frequency Oscillator) 32 Electrical Components 33 Electric Fan for Cooling 34 Air Duct B Blower Means BF Electric Fan

Claims (1)

[Claims] 1. A heating chamber for heating a cooked food and a storage chamber for storing a high-frequency oscillator and electrical components are defined in a casing, and the storage chamber contains a part or all of the high-frequency oscillator therein. An air duct that connects the storage chamber and the heating chamber is provided, and the outside air sucked by the electric fan for cooling provided in the storage chamber cools the electrical components and removes the sucked outside air. In a microwave oven having a cooling device that guides the air into the air duct and cools the high-frequency oscillator with the outside air passing through the air duct, and then exhausts the outside air into a heating chamber, the cooling device is driven by an air flow in the air duct. A microwave oven provided with a blower for effectively cooling the electric component.