KR0146829B1 - Noise control method of microwave oven - Google Patents

Abstract

The present invention relates to a noise control device and a method of microwave oven for effectively attenuating noise generated during the operation of the microwave oven, the microwave oven, the control means, and generating a high frequency in accordance with the control of the control means A rotation speed to cool the magnetron according to a magnetron, a temperature conversion means for detecting a surface temperature of the magnetron that changes when the magnetron is driven, and converting contact terminals, and a contact terminal converted by the temperature conversion means; It is characterized by consisting of a fan motor to drive.

Description

Microwave noise control device and its method

1 is a detailed circuit diagram of a noise control apparatus for a microwave oven according to an embodiment of the present invention;

2 is a flowchart illustrating a noise control operation procedure of the microwave oven according to the present invention.

* Explanation of symbols for main parts of the drawings

10: cooking input means 20: power supply means

21: decompression transformer 23: rectifier

30: control means 40: high frequency output means

41: High voltage transformer 43: Magnetron

50: cooling means 51: fan motor

60: temperature conversion means 70: protection means

80: display means

The present invention relates to a noise control device and a method of a microwave oven for effectively attenuating noise generated during operation of the microwave oven.

In general, in a conventional microwave oven, when a user places food in a cooking chamber and presses a start button, the magnetron generates a high frequency by receiving a high pressure from a high voltage transformer.

The high frequency generated in the magnetron is guided into the cooking chamber through the waveguide and starts to heat the rotating food in the cooking chamber. At this time, the cooling fan motor to protect each component from the high temperature and high temperature of the various high temperature components including the magnetron. Is driven.

When the fan motor is driven, the cooling fan coupled to the fan motor is rotated in conjunction with it to cool air from the outside into the main body to cool the various high temperature parts, including the magnetron.

At this time, in order to increase the amount of air introduced into the main body from outside, noise and fluid generated when the fan motor is driven because a cover is put around the fan motor or the rotation speed of the fan motor is maximized (about 3000 rpm). Not only the performance of the device is lowered due to the exhaust noise caused by vibration generated when the air moves, but also there is a problem that the user is uncomfortable due to the noise.

Thus, a method of reducing the noise and vibration of the fan motor by using a sponge or a tape has also been proposed, but it is not effective considering the fact that the manufacturing process is complicated and the manufacturing cost increases due to the use of ancillary parts.

Therefore, the present invention has been made to solve the above problems, the object of the present invention is to control the rotational speed of the fan motor in two stages according to the changing surface temperature of the magnetron can not only reduce the noise more effectively Rather, to provide a noise control device and a method of microwave oven that can reduce the manufacturing cost.

Another object of the present invention is to provide a noise control device and method of a microwave oven that can satisfy the user's satisfaction with the product because the low temperature of the magnetron can reduce the noise by rotating the fan motor at a low speed. have.

Still another object of the present invention is that when the surface temperature of the magnetron is a high temperature, the fan motor can be rotated at a high speed to cool the magnetron in a short time, so that the noise of the microwave oven can be prevented from overheating of the parts to ensure the safety of the device. It is to provide a control device and a method thereof.

In order to achieve the above object, a noise control apparatus for a microwave oven according to the present invention includes a control unit, a magnetron for generating a high frequency under control of the control unit, and a magnetron that changes when the magnetron is driven. It characterized by consisting of a fan motor for switching the rotational speed to cool the magnetron in accordance with the contact terminal converted by the temperature conversion means and the temperature conversion means for sensing the surface temperature.

In addition, the noise control method of the microwave oven according to the present invention is a temperature sensing step for detecting the surface temperature of the magnetron that is changed during the high frequency output of the magnetron, and whether the surface temperature of the magnetron detected in the temperature sensing step is a low temperature? A low temperature discrimination step for discriminating, a low speed rotation step for rotating the fan motor at a low speed to cool the magnetron when the surface temperature of the magnetron is low, and whether the surface temperature of the magnetron detected in the temperature sensing step is high temperature And a high speed rotation step of rotating the fan motor at a high speed to cool the magnetron when the surface temperature of the magnetron is high.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the cooking input unit 10 is configured to input various cooking functions (cooking time setting, cooking menu selection, microwave output control of a microwave oven, start / stop of cooking operation, etc.) desired by a user. Is a function key on the front control panel of the microwave oven.

The power supply unit 20 receives the power supply voltage of the commercial AC power supplied from the AC power input terminal 1, converts the power supply voltage into a predetermined DC voltage required for driving the microwave, and outputs the power supply means 20. The decompression transformer 21 receives the power supply voltage of the commercial AC power supplied from the AC power input terminal 1 on the primary side, decompresses to a predetermined low voltage, and discharges it to the secondary side, and decompresses it by the decompression transformer 21. It is comprised by the rectification part 23 which converts the alternating voltage into predetermined | prescribed DC voltage, and outputs.

In addition, the control means 30 is applied to the DC voltage output from the power supply means 20 to initialize the microwave oven and at the same time the overall operation of the microwave oven according to the key signal input by the cooking input means 10 Microcomputer to control the

In addition, the high frequency output means 40 receives the power voltage of the commercial AC power supplied from the AC power input terminal 1 under the control of the control means 30 to generate a high frequency (microwave) to heat food in the cooking chamber. By outputting, the high frequency output means 40 receives the power supply voltage of the commercial AC power supplied from the AC power input terminal 1 on the primary side, converts it to high voltage, and induces the secondary voltage to the secondary side. And a magnetron 43 for generating a high frequency by receiving the high voltage converted by the high voltage transformer 41, a high voltage capacitor C1 for charging the induced voltage in the secondary winding of the high voltage transformer 41, and It consists of a high voltage diode (D1) for rectifying the voltage charged in the high voltage capacitor (C1) to a double voltage of high voltage and low current.

In addition, in the figure, the cooling means 50 cools the magnetron 43 under the control of the control means 30 at the time of high frequency output of the magnetron 43. The commercial alternating current supplied from the AC power input terminal 1 during the on / off operation of the fan motor relay RY2 and the fan motor relay RY2 that is turned on / off by receiving a control signal output from the control means 30. The fan motor 51 is rotated to receive the power supply voltage of the power source and to cool the magnetron 43.

In addition, the temperature conversion means 60 detects the surface temperature of the magnetron 43 that changes during the high frequency output of the magnetron 43, and the contact terminal to control the rotational speed of the fan motor 51 in two stages. As a bimetal switch for converting, the temperature converting means (60) is a common terminal (COM) and a normally closed terminal (NC; normally closed terminal) when the surface temperature of the magnetron (43) is low (about 70 ° C). And the common terminal COM and the normally open terminal (NO; NORMAL OPEN; hereinafter referred to as open terminal) when the surface temperature of the magnetron 43 is high (about 150 ° C). To come on.

On the other hand, the fan motor 51 of the cooling means 50 is the common terminal COM of the temperature conversion means 60 when the surface temperature of the magnetron 43 detected by the temperature conversion means 60 is a low temperature When the surface temperature of the magnetron 43 is high, the common terminal COM of the temperature converting means 60 and the open terminal NO are connected to each other. It rotates at high speed (3000rpm) and converts the rotation speed into two stages.

In addition, the protection means 70 is to protect the circuit safely during the high frequency output from the high frequency output means 40, the protection means 70 receives the control signal output from the control means 30 to receive the high pressure The main relay RY1 turned on / off to control the power voltage supplied to the transformer 41 and the fan motor 51, and the high voltage transformer from the AC power input terminal 1 when the temperature of the cooking chamber rises excessively. 41) and the temperature switch 71 connected to one end of the AC power input terminal 1 so as to cut off the power voltage supplied to the decompression transformer 21, and the AC power input terminal 1 when overcurrent flows in the circuit. And a fuse 73 connected to the other end of the AC power input terminal 1 so as to cut off the power supply voltages supplied to the high voltage transformer 41 and the reduced pressure transformer 21.

In addition, the display means 80 displays a cooking time, a cooking menu, etc. input by the user by the cooking input means 10.

Hereinafter, the operation of the noise control device and method of the microwave oven configured as described above will be described.

FIG. 2 is a flowchart showing the operation procedure of the output conversion control of the microwave oven according to the present invention. In FIG. 2, S denotes a step.

First, when power is supplied to the microwave oven, the power supply voltage of the commercial AC power supplied from the AC power input terminal 1 is applied to the primary side of the decompression transformer 21 of the power supply means 20.

At this time, the decompression transformer 21 reduces the power supply voltage from the AC power supply input terminal 1 applied to the primary side to a low voltage suitable for the operation of the circuit and outputs it to the rectifying unit 23 on the secondary side.

Therefore, the rectifier 23 converts the AC voltage reduced by the decompression transformer 21 into a predetermined DC voltage necessary for driving the microwave oven and outputs it to the control means 30 and each driving circuit.

Accordingly, in step S1, the DC voltage output from the rectifying unit 23 is applied by the control means 30 to initialize the microwave oven in accordance with the cooking operation.

At this time, in step S2, the food to be cooked is placed in the cooking chamber, and the cooking input means 10 inputs a cooking time or cooking menu desired by the user.

Subsequently, in step S3, it is determined whether the start button of the cooking input means 10 is turned on. If the start button is not turned on (NO), the process returns to the step S3 and repeats the operation of step S3 or less. If the start button is turned on (YES), the control means 30 goes to the main relay RY1 and the high voltage relay RY3 through the output terminals 01, 02 and 05, 06. Output a high level control signal.

Therefore, the relay coils L1 and L3 connected to the output terminals 01, 02 and 05 and 06 of the control means 30 in accordance with the high level control signal output from the control means 30. As the current is induced in the main relay RY1 and the high voltage relay RY3 are turned on.

When the main relay RY1 and the high voltage relay RY3 are turned on, in step S5, the power supply voltage of the commercial AC power supplied from the AC power input terminal 1 is supplied to the primary side of the high voltage transformer 41 of the high frequency output means 40. It is applied at and converted to high pressure and induced to secondary side.

Accordingly, the magnetron 43 receives the high pressure induced on the secondary side of the high voltage transformer 41 to generate a high frequency to start heating food in the cooking chamber.

Subsequently, in step S6, the surface temperature of the magnetron 43, which changes at the high frequency output of the magnetron 43, is sensed by the temperature converting means 60, and the flow proceeds to step S7 to be sensed by the temperature converting means 60. It is discriminated whether or not the surface temperature of the magnetron 43 is low temperature (about 70 ° C).

As a result of the discrimination in step S7, when the surface temperature of the magnetron 43 is low (YES), the magnetron 43 is not yet overheated, and therefore the fan motor 51 rotates at low speed (step S8). The common terminal COM and the closing terminal NC of the temperature converting means 60 are connected to generate 1500 rpm.

At this time, the control means 30 outputs a high level control signal to the fan motor relay RY2 through the output terminals 03 and 04.

Accordingly, the fan motor relay RY2 is induced while the current is induced in the relay coil L2 connected to the output terminals 03 and 04 of the control means 30 according to the high level control signal output from the control means 30. Comes on.

When the fan motor relay RY2 is turned on, the coil of the fan motor 51 is connected to the terminal A and the terminal B according to the connection between the common terminal COM and the closing terminal NC of the temperature conversion means 60. The fan motor 51 starts to rotate at a low speed (1500 rpm).

When the fan motor 51 is rotated at a low speed, the cool air from the outside is introduced into the main body through a suction port (not shown) to cool the magnetron 43 that is raised to a low temperature (normal temperature) according to the use of a microwave while making noise. Can be reduced.

On the other hand, when the determination result in step S7, if the surface temperature of the magnetron 43 is not low temperature (NO), go to step S9 and the surface of the magnetron 43 detected by the temperature conversion means 60 It was determined whether the temperature was high temperature (about 150 ° C).

As a result of the discrimination in step S9, when the surface temperature of the magnetron 43 is high (YES), the temperature of the magnetron 43 rises due to prolonged use of the microwave and is overheated. The common terminal COM and the closing terminal NC of the temperature converting means 60 are disconnected so that the 51 generates a high rotational speed (3000 rpm), and the common terminal COM and the open terminal NO are connected to each other.

At this time, the control means 30 similarly outputs a high level control signal to the fan motor relay RY2 through the output terminals 03 and 04 at the low speed rotation of the fan motor 51.

Accordingly, the fan motor relay RY2 is induced while the current is induced in the relay coil L2 connected to the output terminals 03 and 04 of the control means 30 according to the high level control signal output from the control means 30. Comes on.

When the fan motor relay RY2 is turned on, the coil of the fan motor 51 is connected to the terminal A and the terminal C according to the connection between the common terminal COM and the open terminal NO of the temperature converting means 60. The fan motor 51 starts to rotate at a high speed (3000 rpm).

When the fan motor 51 is rotated at a high speed, the cool air from the outside is introduced into the main body more than the low speed rotation to prevent the overheating of the parts while cooling the magnetron 43, which is overheated by using the microwave for a long time, in a short time. You can do it.

In addition, when the magnetron 43 is cooled by the high speed rotation of the fan motor 51 and the surface temperature is lowered (about 70 ° C.), the common terminal COM and the open terminal NO of the temperature converting means 60 are reduced. ), The common terminal COM and the closing terminal NC are connected.

Therefore, the fan motor 51 is rotated again at a low speed to maintain a low noise operating state.

If the surface temperature of the magnetron 43 is not high (NO) as a result of the discrimination in step S9, the process returns to step S7 to repeat the operation of step S7 or less.

Meanwhile, in one embodiment of the present invention, the on / off temperature control of the temperature conversion means 60, which is a bimetal switch, is set to 150 ° C./70° C., but the on / off temperature condition of the bimetal can be changed according to a product. Of course.

According to the noise control device and method of the microwave oven according to the present invention as described above, by controlling the rotational speed of the fan motor in two stages according to the changing temperature of the magnetron can not only reduce the noise more effectively In addition, the manufacturing cost can be reduced, and if the surface temperature of the magnetron is low, the fan motor can be rotated at a low speed to reduce noise, thereby satisfying the user's satisfaction with the product, and the surface temperature of the magnetron is increased. At high temperatures, the fan motor can be rotated at a high speed to cool the magnetron in a short time, thus preventing the parts from overheating and ensuring the safety of the device.

Claims (3)

A microwave oven comprising: a control means, a magnetron for generating a high frequency under the control of the control means, a temperature converting means for detecting a surface temperature of the magnetron that changes when the magnetron is driven, and converting contact terminals; Noise control device of a microwave oven, characterized in that the fan motor for driving by switching the rotation speed to cool the magnetron according to the contact terminal converted by the conversion means. The noise control apparatus of a microwave oven according to claim 1, wherein the temperature converting means is a bimetal switch for controlling the rotational speed of the fan motor in two stages by converting a contact terminal according to the surface temperature of the magnetron. A temperature sensing step of sensing the surface temperature of the magnetron that changes at the high frequency output of the magnetron, a low temperature discrimination step of determining whether the surface temperature of the magnetron sensed in the temperature sensing step is a low temperature, and a surface temperature of the magnetron When the temperature is low, a low speed rotation step of rotating the fan motor at a low speed to cool the magnetron, a high temperature discrimination step of determining whether the surface temperature of the magnetron sensed by the temperature sensing step is high temperature, and a surface temperature of the magnetron is high temperature And a high speed rotating step of rotating the fan motor at a high speed to cool the magnetron.