KR20020039498A - A door latch apparatus for microwave oven - Google Patents

Abstract

PURPOSE: A door latch device for a microwave oven is provided to prevent leakage of microwave by reducing size of a latch slot and to reduce a producing cost by simplifying a latch board. CONSTITUTION: A door latch device of a microwave oven comprises a front plate forming a front face of a cavity; a door(50) attached to the front plate; a latch slot(22) mounted on the front plate; a latch inserted to the latch slot by being installed on the door; a latch board(30) arranged on an inner face of the front plate; a stopper(32) formed on the latch board; a latch lever(40) controlled by the stopper; guide pins(34,34') guiding a moving orbit of the latch lever; an interlock switch(36) mounted on the latch board with a monitor switch(38); and a latch lever spring(41) located in a spring placing unit of the latch lever. Thereby, the door latch device of the microwave oven prevents leakage of microwave by reducing size of the latch slot.

Description

A door latch apparatus for microwave oven

The present invention relates to a microwave oven, and more particularly to a door latch device for detecting the opening and closing state of the door.

A microwave oven uses microwaves to heat food, and when the microwave is applied to a person, the part is heated. Therefore, microwaves should be kept to minimize leakage of microwaves. In addition, the microwave oven is driven while the door is opened to prevent the microwaves from being transmitted to the outside. To this end, a latch device is employed in the door of the microwave oven to prevent the door from being opened. Of course, the latch device may also serve to keep the door locked to the front plate of the microwave oven.

1 shows a configuration of a latch apparatus of a microwave oven according to the prior art. According to this, the front plate 1 forms a front surface of a cavity (not shown) in which a cooking chamber (not shown) is provided. A latch slot 2 is formed at one side of the front plate 1. The latch slot 2 is a portion in which the latch 16 of the door 15 to be described below is moved into and out of the front plate 1.

A latch board 3 is installed on an inner surface of the front plate 1. The latch board 3 may be installed on the left and right sides or one side up and down of the front plate 1 according to the opening and closing method of the door 15. The latch board 3 is fastened to the outer surface of the cavity as an injection molded product. The latch board 3 is provided with various switches to be described below and levers for driving the switches. To this end, when the structure for the installation of the switch and the lever is formed on the latch board 3, in particular, the center of rotation (4, 5) of the lever is formed to protrude. The latch seating part 6 is formed at the position of the latch board 3 corresponding to the latch slot 2.

A first latch lever 7 is installed at the rotation center 4. In addition, the second latch lever 8 is elastically supported by the latch spring 9 at the rotation center 5. The monitor switch 9 is installed at a position adjacent to the rotation center 4 of the first latch lever 7, and the first interlock switch 10 is positioned at a position corresponding to the front end of the first latch lever 7. Is installed. In addition, a second interlock switch 12 is installed at a position adjacent to the front end of the second latch lever 8.

On the other hand, the door 15 is used to selectively open and close the cooking chamber, the door 15 is provided with a latch 16. The latch 16 is generally elastically supported in one direction by a spring 17.

Referring to the operation of the latch device according to the prior art having such a configuration as follows.

The latch device serves to detect the open / closed state of the door 15 and the door 15 to be in close contact with the front plate 1. That is, when the door 15 is opened, the monitor switch 9 is turned on, and the first and second interlock switches 10 and 12 are turned off to provide a signal so that the microwave oven is not driven.

When the door 15 is closed, the latch 16 enters the inside of the front plate 1 through the latch slot 2 and is seated on the latch seat 6. In this way, when the latch 16 is seated on the latch seat 6, the first latch lever 7 and the second latch lever 8 are operated to turn off the monitor switch 9. The second interlock switches 10 and 12 are turned on so that the microwave oven can be operated.

However, the latch device according to the related art as described above has the following problems.

First, since the latch 16 is supported by the door 17 to the spring 17, the elastic force of the spring 17 weakens during long time use, and the latch 16 may not function properly.

In the conventional latch device, the latch 16 supports the spring 17 on the door 15 and the first and second latch levers 7 and 8 on the latch board 3 rotate centers 4 and 5. It is installed so as to rotate around the assembly error of these accumulate or if the position is changed during operation, malfunction occurs.

When a malfunction occurs in this way, when the door 15 is closed, the order in which the monitor switch 9 is operated and the interlock switches 10 and 12 are operated, and when the door 15 is opened, the interlock switches 10 and 12 Is operated and the order in which the monitor switch 9 is operated is changed, thereby causing damage to the circuit of the microwave oven.

On the other hand, since the latch 16 is supported by the spring 17 on the door 15, and the front end of the latch 15 is installed so as to rotate itself by a predetermined angle, the latch slot 2 is relatively rotated. ) Should be large. As such, when the latch slot 2 is large, leakage of microwaves through the latch slot 2 is large.

Therefore, an object of the present invention is to solve the problems of the prior art as described above to provide a door latch device with improved durability and operation reliability.

Relatively reducing the size of the latch slot to prevent microwave leakage.

1 is a plan view showing the configuration of a door latch device for a microwave oven according to the prior art.

Figure 2 is an operating state showing that the door latch apparatus of the microwave oven according to the prior art is operated.

Figure 3 is a plan view showing the configuration of a preferred embodiment of the door latch apparatus for a microwave oven according to the present invention.

Figure 4 is an operating state showing the state in the middle of the door closing in the door latch device of the embodiment of the present invention.

Figure 5 is an operating state showing the door closed state in the door latch device of the embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

20: front plate 22: latch slot

30: latch board 32: stopper

34,34 ': Guide pin 36: Interlock switch

38: monitor switch 40: latch lever

41: latch lever spring 42,42 ': guide hole

44: spring seat 46: first cam portion

48: second cam portion 50: the door

52: latch

According to a feature of the present invention for achieving the above object, the present invention is a latch that is fixed to the door for opening and closing the cooking chamber inside the cavity, and is mounted on the rear of the front plate of the cavity to detect the opening and closing state of the door And a latch board having a plurality of switches, and a latch lever installed at one side of the latch board and driving the switch while linearly reciprocating as the latch moves along the opening and closing of the door.

The latch lever is elastically supported by a spring on the latch board, and has a cam portion for sequentially operating the plurality of switches.

The plurality of switches are respectively provided on both sides of the linear reciprocating movement path of the latch lever and operated by the cam part at a time difference.

With reference to the accompanying drawings, a preferred embodiment of a door latch device for a microwave oven according to the present invention having such a configuration will be described in detail.

As shown in FIG. 3, the front plate 20 constitutes a front surface of a cavity (not shown) having a cooking chamber (not shown) therein. The front plate 20 forms the front edge of the cooking chamber while forming the front surface of the cavity, so that the inner surface of the door 50 to be described below is in close contact. The front plate 20 is formed with a latch slot 22 into which the latch 52 of the door 50 is inserted.

A latch board 30 is installed on an inner surface of the front plate 20. A stopper 32 is formed on the latch board 30. The stopper 32 serves to regulate the movement of the latch lever 40 to be described below. And guide pins (34, 34 ') for guiding the movement trajectory of the latch lever 40 is formed on the latch board (30).

The interlock switch 36 and the monitor switch 38 are installed on the latch board 30. In this case, the two interlock switches 36 may be installed to overlap each other. In this way, the interlock switch 36 is installed so that one is used as an auxiliary. The interlock switch 36 and the monitor switch 38 as described above are installed to face each other. The interlock switch 36 is in a depressed state and the monitor switch 38 is in a depressed state.

Meanwhile, a latch lever 40 is installed on the latch board 30. The latch lever 40 tends to be moved in the direction of the latch 52 to be described below by the latch lever spring 41. The latch lever spring 41 is positioned in the spring seat 44 of the latch lever 40 so that one end is supported by the stopper 32 and the other end is supported by one side of the latch lever 40. In addition, guide holes 42 and 42 'are formed on the latch lever 40 to guide the guide pins 34 and 34'. The guide holes 42 and 42 'control the movement trajectory of the latch lever 40 together with the guide pins 34 and 34'.

First and second cam portions 46 and 48 are formed at upper and lower ends of the latch lever 40, respectively. The first and second cam parts 46 and 48 are configured to sequentially operate the interlock switch 36 and the monitor switch 38. When the door 50 is closed, as shown in FIG. 1 cam portion 46 is formed so as to touch and press the monitor switch 38 first.

On the other hand, the latch 52 is fixed to the door 50 in close contact with the front plate 20 to close the cooking chamber from the outside. Here, the latch 52 is formed of a metal and is fastened to the door 50 by welding or the like. Accordingly, the latch 52 does not move at all with respect to the door except for the movement trajectory according to the opening and closing of the door 50.

Hereinafter, the operation of the door latch device of the microwave oven according to the present invention having the configuration as described above.

First, FIG. 3 illustrates a state in which the door 50 is opened. At this time, the latch lever 40 is moved toward the latch slot 22 by the latch lever spring 41. Both the interlock switch 36 and the monitor switch 38 are not pressed, so the interlock switch 36 is off and the monitor switch 38 is on.

When the door 50 is closed in this state, the latch 52 of the door 50 enters through the latch slot 22. The latch 52 presses the latch lever 40. Accordingly, the latch lever 40 starts to move in the direction of the arrow of FIG. 4 while overcoming the elastic force of the latch lever spring 41. The movement of the latch lever 40 is guided by the guide holes 42 and 42 'and the guide pins 34 and 34'.

Then, the first cam portion 38 first presses the monitor switch 38 to turn off. This state is well illustrated in FIG. 4.

Subsequently, when the door 50 is closed, the latch 52 completely enters the latch slot 22 to further push the latch lever 40. Accordingly, the second cam portion 48 of the latch lever 40 is turned on by pressing the interlock switch 36. In this case, the door 50 is closed, and the interlock switch 36 provides the control unit to the state in which the microwave oven can operate.

On the other hand, when the door 50 is opened in the state of FIG. 5, since the force that the latch 52 presses the latch lever 40 is removed, the latch lever 40 is restored by the restoring force of the latch lever spring 41. ) Moves toward the latch slot 22. At this time, when the latch 52 of the door 50 exits the latch slot 22, the latch lever 40 moves to the position of FIG. 3 to press the interlock switch 36 and the monitor switch 38. Release it. Thus, the interlock switch 36 is turned off and the monitor switch 38 is turned on.

In the latch apparatus of the microwave oven according to the present invention as described above in detail, since the latch lever drives the interlock switch and the monitor switch while linearly reciprocating, there is no unnecessary operation and the latch of the door is operated without moving separately. The operation can be made more accurately, thereby preventing damage to the circuit of the microwave oven.

In addition, since the operation of the latch lever for the operation of the switch is simple, the shape of the latch board is simplified, so that the shape of the latch board installed at the positions corresponding to both sides of the door can be made identical, thereby reducing the manufacturing cost.

In addition, since the latch does not move relative to the door, the size of the latch slot of the front plate can be minimized, thereby minimizing microwave leakage.

Claims (3)

A latch fixed to a door that opens and closes the cooking compartment inside the cavity; A latch board mounted to the rear of the front plate of the cavity and having a plurality of switches for detecting an open / closed state of the door; And a latch lever installed at one side of the latch board and configured to drive the switch while linearly reciprocating as the latch moves along the opening and closing of the door. The door latch device according to claim 1, wherein the latch lever has a cam portion elastically supported by a spring on the latch board and sequentially operates the plurality of switches. The door latch device according to claim 1 or 2, wherein the plurality of switches are provided at both sides of the linear reciprocating movement path of the latch lever, and are operated at a time difference by the cam part.