JPS623557B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a microwave oven having an oven cooking function, and particularly to an air cooling device thereof.

(Prior Art) In this type of conventional microwave oven, an air cooling device (for example, a fan) is provided to send cooling air to a high frequency generation source (for example, a magnetron) in the machine room in the microwave cooking (high frequency heating) mode. This cooling air is further guided to a ventilation path for discharging water vapor and the like generated from the food in the oven (cooking chamber) to the outside of the oven.

However, in the oven cooking (heater cooking) mode, introducing cooling air into the ventilation path would lower the temperature inside the oven, so the air cooling device was stopped and the interior of the machine room was left to natural heat dissipation.

(Problems to be Solved by the Invention) In the configuration of such a conventional microwave oven, the inside of the oven and the machine room are not sufficiently insulated, so the temperature inside the machine room becomes considerably high during oven cooking. For this reason, it is necessary to use electrical parts with high heat resistance to be installed in the machine room, which increases the unit cost of the parts.Also, it is generally difficult to use printed circuit boards that are sensitive to heat, and when using microcomputers, Since the temperature conditions cannot be guaranteed, there is a drawback that problems such as malfunctions may occur.

This invention has been made in view of the above circumstances, and an object of the present invention is to provide a microwave oven that can reduce the cost of electrical components used and stabilize operation by forcing air cooling inside the machine room even in oven cooking mode. With the goal.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention has a method in which, in the microwave cooking mode, the cooling air sucked in from outside the microwave through the ventilation holes by the fan is used. By blowing air toward the high frequency generator, air is sent into the oven through the duct, and in oven cooking mode, the air blowing direction of the fan is reversed and air is sent toward the ventilation hole, which draws air from outside the oven to the bottom of the cabinet in the machine room. The structure is such that the machine room is mainly cooled by cooling air sucked in through the holes.

(Function) In the above configuration, in microwave cooking mode,
The fan blows cooling air toward the high-frequency generator to forcibly cool the high-frequency generator. On the other hand, in oven cooking mode, the fan blows air in the opposite direction and blows the air toward the ventilation holes. Since the high-frequency generator protruding into the machine room acts as a large resistance to blowing air, most of the cooling air bypasses the machine room where the blow resistance is small, effectively cooling the electrical components in the machine room. , it is possible to reduce the cost of the parts used and stabilize the operation.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In the microwave oven shown in FIGS. 1 and 2, reference numeral 1 denotes a cabinet in which an oven 2 and a machine room 3 are formed. Machine room 3
In this case, a magnetron 4 is mounted on the upper part so as to protrude from the oven side, and behind this magnetron 4 there is a first fan 5 that closely opposes the magnetron 4, and from this first fan there is a Cabinet 1 located far away
A second fan 6 is disposed close to the rear surface. Further, in front of the magnetron 4, a duct 7 is arranged to introduce cooling air blown toward the magnetron 4 by the first fan 5. That is, one end of the duct 7 is connected to the magnetron 4, and the other end is connected to a ventilation hole provided in the oven wall 8. Further, a waveguide 9 is disposed between the antenna section 4' of the magnetron 4 and a microwave supply hole provided on the upper surface of the oven wall. Inside the oven 2, blades (not shown) are provided which are rotated by the wind coming in from the ventilation hole and agitate the microwaves guided from the supply hole. Exhaust holes (not shown) are provided in the oven wall to guide the input air from the holes out of the oven. Further, the cabinet 1 is provided with an exhaust hole (not shown) for discharging water vapor etc. discharged from the exhaust hole in the oven wall to the outside of the oven. A ventilation hole 10 is provided, and an intake hole 11 is further provided in the front of the bottom surface of the cabinet 1. In addition, in the lower part of the machine room 3, a component mounting plate 12 to which electrical components are attached, a high voltage transformer (for obtaining high voltage for the magnetron) 13, etc. are provided, and a microcomputer etc. is provided in the front. . This printed circuit board 14 is supported on the back side of a panel frame 15 (used as a microwave operation panel, etc.) at the front end of the cabinet 1.

In the above configuration, the circuit is connected so that the first fan 5 is driven when cooking in the microwave cooking mode, and the second fan 6 is driven when cooking in the oven cooking mode.
and the second fan 6 are provided so that their rotation directions are opposite to each other.

Next, the operation of the microwave oven will be explained.

During cooking in the microwave cooking mode, the rotation of the first fan 5 that is close to the magnetron 4 causes the cooling air sucked in from outside the microwave through the vent 10 to cool the magnetron 4, and the cooling air also cools the magnetron 4. is discharged from the duct 7→inside the oven→oven wall exhaust hole→cabinet exhaust hole→outside the oven, and at the same time, water vapor and the like generated during cooking of food in the oven are also discharged outside the oven. Of course, a part of the air sucked through the ventilation hole 10 is not taken into the duct 7, but cools the inside of the machine room 3, and also escapes from the air intake hole 11 on the bottom of the cabinet 1 to the outside of the range. However, since the first fan 5 blows cooling air toward the adjacent magnetron 4, most of the cooling air is forced into the duct 7 side after cooling the magnetron 4. Therefore, relatively little air escapes from the intake hole 11 through the machine room 3.

On the other hand, during cooking in the oven cooking mode, the second
As the fan 6 rotates, the cooling air sucked in from outside the oven through the intake hole 11 on the bottom of the cabinet 1 cools the component mounting plate 12, printed circuit board 14, etc. in the machine room 3, and this cooling air flows into the cabinet 1.
is discharged from the oven through the vent hole 10 of the oven. That is,
When this second fan 6 rotates, the suction force is widely dispersed due to the characteristics of the fan, and the magnetron 4 protruding into the machine room acts as a large resistance element for blowing air. The electrical components inside the machine room can be effectively cooled by bypassing the small machine room. Of course, the rotation of the second fan 6 also tries to draw air from the air path on the magnetron 4 side, but there are many cooling fans in the air path of the magnetron 4, and the oven 2 connected to the duct 7
Since the airflow resistance is extremely large due to the large number of punched holes in the airflow path, most of the cooling air flows into the machine room 3 where the airflow resistance is small.

In the above embodiment, two fans were used, but in place of this, one fan capable of forward and reverse rotation is used, and the circuits are connected so that they can be reversed in microwave cooking mode and oven cooking mode. Good too.

[Effects of the Invention] As described above, the present invention can effectively cool the electrical components in the machine room in each mode of microwave cooking mode and oven cooking mode, so it is possible to reduce the cost of used components and stabilize the operation. We can provide a microwave.

[Brief explanation of the drawing]

The drawings show an embodiment of a microwave oven according to the present invention, and FIGS. 1 and 2 are a top view and a side view, respectively, showing the arrangement inside the microwave oven. In the figure, 1 is a cabinet, 2 is an oven, 3 is a machine room, 4 is a magnetron, 5 and 6 are fans, 1
0 is a ventilation hole, 11 is an intake hole, 12 is a parts mounting plate,
14 indicates a printed circuit board.

Claims (1)

[Claims] 1. A cabinet, an oven provided inside the cabinet, a machine room formed between the oven and the cabinet for housing electrical components, and a high frequency generator mounted on the oven side so as to protrude into the machine room. A generator, a fan disposed behind the high-frequency generator, a ventilation hole provided on the rear surface of the cabinet in the machine room opposite to the fan, and a vent provided on the front side of the bottom surface of the cabinet in the machine room. A microwave oven comprising an air intake hole and a duct provided in front of the high frequency generator and communicating with the inside of the oven, and capable of selecting a range cooking mode in which food in the oven is heated by high frequency and an oven cooking mode in which food is heated by a heater. In the cooking mode, the cooling air sucked in from outside the oven through the ventilation hole by the fan is blown toward the high-frequency generator and into the oven through the duct, and in the oven cooking mode, the direction of the fan's air is reversed. The microwave oven is characterized in that the machine room is mainly cooled by the cooling air sucked in from outside the oven through the intake hole by blowing air toward the ventilation hole.