KR20020016234A - Microwave oven - Google Patents

Abstract

PURPOSE: A microwave oven is provided to reduce the number of switches, simplify circuit structure, and meet specification for a safety switch of a door. CONSTITUTION: A microwave oven comprises a body including a cooking room and a machinery room, a door, an operating panel, and a safety device. The safety device includes a safety switch part having a first door switch(45), a second door switch(47) and a monitor switch(49). The first door switch(45) is operated depending on open/closed state of the door. The monitor switch(49) is operated in opposite to the first and the second door switches(45,47). When the door is closed, the first door switch(45) is closed and the monitor switch(49) is opened so as to supply power to a magnetron(33) for generating a microwave and providing it to the cooking room. When the door is opened, the first door switch(45) is opened so as to power off the magnetron(33). The microwave oven further comprises a controller for powering off a magnetron(33) when the door is opened while the three switches(45,47,49) are all open or all closed.

Description

Microwave oven

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 safety device for a door with a simplified wiring structure.

A conventional microwave oven has a main body having a cooking chamber and a component chamber, a door for blocking the front opening of the cooking chamber to open and close an opening, and an operation panel provided in one region of the main body to drive a plurality of appliance parts. The component chamber is provided with a high voltage transformer that generates power by receiving power from a power supply unit (see FIG. 5) and a magnetron that generates electromagnetic waves by the high voltage generated by the high voltage transformer.

The microwave oven is provided with a safety device for preventing electromagnetic waves from being supplied to the cooking chamber with the door open. The safety device has a latch member provided in the door to be coupled to a pair of hook grooves provided in the front opening area of the cooking chamber, and a safety switch that opens and closes upon opening and closing of the door. The latch member has a pair of locking jaws formed to hook the hook groove, and the safety switch has a first door switch, a second door switch, and a monitor switch that can adjust the opening and closing operation by the operation of the locking jaw provided in the latch member. .

Hereinafter, with reference to the detailed circuit diagram of Figure 5 the conventional door safety device is disclosed.

The conventional microwave oven is a power supply unit 130 for supplying power, a high voltage transformer 131 for generating a high voltage by the power supplied from the power supply unit 130, and a high voltage generated by the high voltage transformer 131. It has a magnetron 133 for generating electromagnetic waves. The present microwave oven has a first current line L2 and a second current line L3 provided at both ends of the primary coil of the high voltage transformer 131, and between the first and second current lines L2 and L3. It is provided with each current line to form a closed circuit has a common current line (L1). The microwave is provided with a safety switch for detecting the on and off of the door, the safety switch is the first door switch 145 and the second door switch 147 that is turned on by the pressing of the latching jaw of the latch member not shown in the circuit diagram It is prepared.

The common current line (L1) is provided with a fuse 135 to cut off the over-current and the power supply unit 130, between the common current line (L1) and the first current line (L2) and the lamp 137 for illuminating the cooking chamber and The fan motor 139 is provided. In addition, between the common current line L1 and the first current line L2 and the common current line L1 and the second current line L3, a monitor switch 149 is turned on when the door is opened and turned off when the door is closed. It is prepared.

By such a configuration, when the door is opened, the first door switch 145 and the second door switch 147 are turned off to cut off the power supplied to the magnetron 133 so that electromagnetic waves are applied to the cooking chamber while the door is opened. You can block it.

Therefore, in the conventional door safety device that checks the opening and closing of the door by using the plurality of safety switches, if the number of safety switches can be reduced and the circuit can be simply configured to cut off the power supply due to the opening and closing of the door, more effective safety It may be possible to provide a device. In other words, if the number of safety switches can be reduced and the switch function specified by the standard agency can be implemented, manufacturing cost can be reduced and the trouble of circuit configuration can be reduced.

Accordingly, an object of the present invention is to provide a microwave oven capable of reducing the number of switches, implementing a simpler circuit, and implementing a switch function defined by a standard organization.

1 is a perspective view of a microwave oven according to the present invention,

2 is a control block diagram according to the door safety device of the present invention.

Figure 3 is a detailed circuit diagram specifically disclosed a safety device of the door according to the present invention,

4 is a control flow diagram of the safety device of the door according to the present invention,

5 is a detailed circuit diagram of a conventional door safety device disclosed in detail.

<Description of Symbols for Main Parts of Drawings>

1: body 3: cooking chamber

5: part room 7: door

11 hook groove 13 latch member

15: locking step L1: common current line

L2: first current line L3: second current line

L4: branch current line 30: power supply

31: high voltage transformer 33: magnetron

35: first fuse 36: second fuse

37: lamp 39: fan motor

41: switch 45: first door switch

47: second door switch 49: monitor switch

50: control unit 52: current inflow prevention unit

According to the present invention, in the microwave oven having a main body with a cooking chamber, a door for opening and closing the cooking chamber, and a magnetron provided in one region of the main body to heat the food housed in the cooking chamber, ; A first door switch which performs a closing operation when the door is closed; A monitor switch connected in series with the power supply unit and performing a reverse operation with the first door switch; At least one fuse provided between the power supply unit and the monitor switch to block an overcurrent; When the first door switch and the monitor switch perform the same operation, it is determined that at least one of the first door switch and the monitor switch is abnormal, and the first door switch and the monitor switch are closed. When the door is opened when the operation is achieved by a microwave oven, characterized in that it comprises a control unit for blocking the power supply to the magnetron.

The control unit may short-circuit the fuse when the door is opened while the first door switch and the monitor switch are closed.

Preferably, the fuse has a first fuse installed adjacent to the power supply unit and a second fuse installed adjacent to the monitor switch, wherein the second fuse has a smaller capacity than that of the first fuse. effective.

It is preferable to further include at least one current inflow prevention unit connected in series with the monitor switch and preventing current from flowing in the reverse direction when the monitor switch performs the closing operation. The current inflow prevention part is effectively a diode.

And a second door switch which performs the same operation as the opening / closing operation of the first door switch, and blocks the power supply from the power supply to the magnetron when the door is opened in connection with the first door switch. desirable.

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

1 is a perspective view of a microwave oven according to the present invention, Figure 2 is a control block diagram according to the door safety device of the present invention. As shown in these figures, the present microwave oven includes a main body 1 having a cooking chamber 3 for accommodating food and a component chamber 5 in which a plurality of appliance parts are installed, and the cooking chamber 3. A door 7 for blocking the front opening and opening and closing the opening, and an operation panel 9 provided in one region of the main body 1 to drive a plurality of device components.

The component chamber 5 is supplied with power from a power supply unit (see FIG. 3) to generate a high voltage, a high voltage transformer 31, and a magnetron 33 to generate electromagnetic waves by a high voltage generated by the high voltage transformer 31. Many appliance components are provided. The microwave oven is provided with a safety device for preventing electromagnetic waves from being supplied to the cooking chamber 3 while the door 7 is open.

1 and 2, the safety device includes a latch member 13 provided at the side of the door 7 to be coupled to a pair of hook grooves 11 provided at the front opening area of the cooking chamber 3, and It has a safety switch which interlocks with the latch member 13 according to the opening and closing of the door 7. The latch member 13 has a pair of catching jaws 15 formed to be hooked to the hook groove 11. The safety switch has a first door switch 45, a second door switch 47, and a monitor switch 49 that can control the opening and closing operation by the operation of the locking step 15 provided in the latch member 13. The first door switch 45 is opened and closed in conjunction with the opening and closing of the door 7, and the monitor switch 47 operates in the opposite direction to the opening and closing operations of the first door switch 45 and the second door switch 49. .

On the other hand, the microwave oven has a first fuse and a second fuse (35, 36) that can block the over-current, and a current inflow prevention unit 52 to prevent the reverse current flows into the circuit when an error occurs in the safety switch It is prepared. The microwave oven is provided with a controller 50 for cutting off the power supplied to the magnetron 33 based on the operation of the safety switch.

The control unit 50 may include the first and second door switches 45 and 47 when the first door switch 45, the second door switch 47, and the monitor switch 49 are all closed or remain open. And any of the monitor switches 49 is determined to be abnormal. After the controller 50 determines that an abnormality has occurred in the safety switch, when the door 7 is opened, the controller 50 forcibly short-circuits at least one of the first fuse and the second fuse 35 and 36 to generate a magnetron. The power supply to 33 is cut off.

Hereinafter, the safety device of the present invention will be described in detail with reference to FIG. 3, which is a detailed circuit diagram of a safety device of a door according to the present invention, and FIG. 4 of a control flow diagram of the safety device of a door according to the present invention.

Microwave oven with a safety device according to the present invention, as shown in Figure 3, a high-voltage transformer for generating a high voltage by the power supply unit 30 for supplying power and the power supplied from the power supply unit 30 ( 31), a commercial current line having one end connected to the power supply unit 30 and the other end connected to the high voltage transformer 31 to form a closed circuit for supplying power, and electromagnetic waves generated by the voltage generated by the high voltage transformer 31. It has a magnetron 33 for generating a.

The commercial current line (see FIG. 3) includes a first current line L2 and a second current line L3, a first current line L2, and a second current line connected to the primary coil of the high voltage transformer 31. It has a common current line L1 provided between (L3) and provided with these 1st and 2nd current lines L2 and L3 to comprise a closed circuit.

On the common current line L1, a power supply unit 30 for supplying power and a first fuse 35 capable of blocking an overcurrent supplied to a plurality of closed circuits such as a magnetron 33 and a load circuit are provided. On the first closed circuit formed by the first current line L2 and the common current line L1, a lamp 37 for illuminating the cooking chamber 3 and a fan motor 39 for driving a blowing fan (not shown) are provided. On the first closed circuit, switches 41 and 43 are provided for controlling the operation of the lamp 37 and the fan motor 39, respectively. By providing the switches 41 and 43 as a relay switch, the on-off control can be realized by the controller 50.

On the other hand, on the second closed circuit formed by the second current line L3 and the common current line L1, a branch current line L4 branched from the common current line L1 and meeting one point of the second current line is provided. . A monitor switch 49 is provided on the branch current line L4 in series with the power supply unit 30 and performs an operation opposite to that of the first door switch 45.

In the branch current line L4, a second fuse connected in series with the first fuse 35 disposed adjacent to the power supply unit 30 between the power supply unit 30 and the monitor switch 49 and blocking an overcurrent on the circuit ( 36) is provided. At least one current inflow preventing unit 52 connected to the branch current line L4 in series with the monitor switch 49 to block current from flowing through the monitor switch 49 while the monitor switch 49 is closed. ) Is provided. The current inflow prevention part 52 is a diode and can prevent the reverse current from flowing through the monitor switch 49 when the monitor switch 49 is closed. In this embodiment, one diode is provided as the current inflow preventing unit 52, but a plurality of diodes can be installed. In this detailed circuit diagram, a number of components such as a low voltage transformer, a temperature sensor, a door sensor sensor switch, and a FET are disclosed.

By such a configuration, when the user closes the door of the microwave oven, the first door switch 45 maintains the closed state, and the monitor switch 49 maintains the open state to supply power to the magnetron 33. Electromagnetic waves generated by the power supplied from the magnetron 33 are supplied to the cooking chamber. On the other hand, when the door 7 of the microwave oven is opened, the first door switch 45 may be kept open to cut off the power supplied to the magnetron 33.

Based on the control flow chart of FIG. 4, the control unit 5 (see FIG. 2) is configured such that the first door switch 45 and the second door switch 47 are closed when the door 7 is open (S10). Determine the recognition (S20). When it is determined that the first door switch 45 and the second door switch 47 are closed when the door 7 is in the open state, the controller 50 controls the first door switch 45 and the second door switch. At least one of 47 is determined to be abnormal (S30). If it is determined that the first door switch 45 and the second door switch 47 are abnormal, the controller 50 opens the second fuse 36 provided between the power supply unit 30 and the first door switch 45. Forced short circuit (S40). When the control unit 50 forcibly shorts the second fuse 36, the power supply to the magnetron 33 can be prevented even when the aperture start signal is input in the door 7 open state, further improving the safety of the circuit. You can.

As such, the power supply unit and the first door switch perform a closing operation when the door is closed; A monitor switch connected in series with the power supply unit and performing an operation and a reverse operation with the first door switch, at least one fuse provided between the power supply unit and the monitor switch to block overcurrent, and the first door When the switch and the monitor switch perform the same operation, it is determined that at least one of the first door switch and the monitor switch is abnormal, and when the first door switch and the monitor switch perform the closing operation. When the door is opened by including a control unit to block the supply of power to the magnetron, it is possible to implement a monitor switch of the microwave forcibly prescribed by the standards body. By reducing the number of switches, the circuit structure can be easily configured, which can reduce manufacturing costs and improve circuit safety.

In the above-described embodiment, a description has been made of forcibly shorting the second fuse when an error occurs in the safety switch, but of course, the first fuse and the second fuse may be simultaneously shorted or the first fuse may be shorted.

In the above-described embodiment, the installation of the diode as a current inflow preventing unit for preventing the inflow of reverse current has been described. However, other device components may be used to prevent the inflow of reverse current through the monitor switch.

As described above, according to the present invention, it is possible to implement a switch function forcibly prescribed by the standards organization. In addition, the number of switches can be reduced to easily implement the wiring structure of the circuit.

Claims (7)

In the microwave oven having a main body with a cooking chamber, a door for opening and closing the cooking chamber, and a magnetron provided in one region of the main body to heat the food contained in the cooking chamber, A power supply unit; A first door switch which performs a closing operation when the door is closed; A monitor switch connected in series with the power supply unit and performing a reverse operation with the first door switch; At least one fuse provided between the power supply unit and the monitor switch to block an overcurrent; When the first door switch and the monitor switch perform the same operation, it is determined that at least one of the first door switch and the monitor switch is abnormal, and the first door switch and the monitor switch are closed. And a control unit which blocks the supply of power to the magnetron when the door is opened. The method of claim 1, And the control unit short-circuits the fuse when the door is opened while the first door switch and the monitor switch are closed. The method of claim 2, And the fuse has a first fuse installed adjacent to the power supply unit and a second fuse installed adjacent to the monitor switch. The method of claim 3, And the second fuse has a smaller capacity than that of the first fuse. The method according to claim 1 or 2, And at least one current inflow preventing part connected in series with the monitor switch and preventing current from flowing in the reverse direction when the monitor switch performs the closing operation. The method of claim 5 Microwave oven, characterized in that the current inflow prevention unit is a diode. The method according to claim 1 or 2, And a second door switch which performs the same operation as the opening / closing operation of the first door switch and blocks the power supply from the power supply to the magnetron when the door is opened in connection with the first door switch. The microwave oven characterized by the above.