KR20010081568A - Microwave oven - Google Patents

Abstract

PURPOSE: A microwave oven is provided to reduce the percent defective by compacting the structure of an output control device and to make assembling easy. CONSTITUTION: An output control device of a microwave oven includes a cam assembly(21) having plural cams(22a,22b,22c,22d) integrally rotating with a tray motor(16) and plural output switches(25a,25b,25c,25d) fixed on the tray motor corresponding to the cams. The cams includes a non-working section to turn off the output switches and a working section to turn on the output switches. Radial width of the working section is various. The ratios of the working section of the cams are 70%, 50%, 30% and 15%. If the cam(22a) of 70% working section is operated, the on-time of a magnetron is 70%. The output switches are microswitches controlling power supply to a high voltage transformer. Therefore, the structure of the output control device is compacted and the percent defective in assembling is reduced. Moreover, assembling of components becomes convenient.

Description

Microwave oven {MICROWAVE OVEN}

The present invention relates to a microwave oven, and more particularly, to a microwave oven capable of reducing costs by simplifying a structure for adjusting a power level.

As shown in FIG. 5, the operation panel 80 of the mechanical microwave oven includes a rectangular cylindrical casing 81 having a rear opening and a timer assembly 60 coupled to the rear of the panel casing 81. do.

The timer assembly 60 has a mechanical timer 61 for setting a cooking time and an output control device 70 for output adjustment, and the timer 61 has a timer gear 62 for operation of the timer 61. ), And a timer shaft 63 is formed on the timer gear 62 so that the cooking time setting from the outside can be manipulated. Similarly, the output control device 70 is equipped with an output gear 71 for output control, and the output gear 71 is provided with an output shaft 72 for operation from the outside.

In the area adjacent to the timer gear 62, a main switch 65 for controlling the power supply to each component of the microwave oven and an output switch 66 for controlling the power supply to the high voltage transformer are provided. The main switch 65 is turned on at the same time as setting the time by operating the timer gear 62, the output switch 66 is repeated on and off in accordance with the operation of the timer gear (62).

The main switch 65 is turned on by a lever (not shown) which is pressurized when the timer gear 62 rotates and rotates toward the main switch 65, and the output switch 66 is the timer gear 62 and the output gear 71. The cam assembly 75 and the operation lever 85 provided therebetween are turned on and off. The main switch 65 and the output switch 66 each have a pair of contact plates formed in parallel to each other, the contact plate on one side is spaced apart and approaching from the other contact plate on and off.

Here, the cam assembly 75 has an operation cam 76 whose position is set by the output gear 71 and a timing cam fixed to the same axis as the operation cam 76 and rotated by the timer gear 62. 77, the cam cam 78 is formed in the operating cam 76 and the timing cam 77, respectively, which is in contact with each other to determine the on-off cycle of the output switch (66). A plurality of transmission gears 90 are interlocked between the output gear 71 and the operation cam 76 to transmit rotation of the output gear 71 by the operation of the output shaft 72 to the operation cam 76. A plurality of transmission gears 90 are also provided between the timer gear 62 and the timing cam 77 to operate the timing cam 77 when the timer 61 is positioned by the timer shaft 63. Done.

The operation lever 85 has a contact arm 86 that contacts the outer circumferential surface of the timing cam 77, and an operation arm 87 that is bent from the contact arm 86 to turn the output switch 66 on and off. A rotation shaft is formed in the connection area between the 86 and the operation arm 87. When the contact arm 86 rotates by contacting the timing cam 77, the operation arm 87 moves one contact plate of the output switch 66. Pressing or depressurizing turns the output switch 66 on and off.

The conventional timer assembly 60 is provided in a single casing so that the timer 61 and the output control device 70 work together, and the cam assembly between the timer 61 and the output control device 70. Numerous transmission gears 90 are provided at 75 to transmit rotational forces from the timer shaft 63 and the output shaft 72. Therefore, as the number of parts is relatively large and the structure thereof is complicated, assembly work is cumbersome. In addition, when the error between the gears is large, since the rotational force from the timer shaft 63 and the output shaft 72 is not transmitted correctly, precise error control is required, and there is a problem that the defective rate of the component is relatively increased.

It is therefore an object of the present invention to provide a power supply control apparatus for a microwave oven capable of simplifying the structure and reducing the defective rate of parts.

1 is an exploded perspective view of a microwave oven,

2 is a cross-sectional view of the tray motor region of the microwave oven according to the present invention;

3 is an exploded perspective view of the tray motor region of FIG. 2;

4 is a perspective view of the combination of FIG.

5 is an exploded perspective view of a conventional operation panel region.

<Description of the symbols for the main parts of the drawings>

1: main body 3: outer casing

4: cooking chamber 6: rotating tray

7: Parts room 9: High voltage transformer

10: magnetron 16: tray motor

17: rotating shaft 20: output control device

21: cam assembly 22: cam

25: output switch 30: operation panel

The object of the present invention is a microwave oven having a cooking chamber provided with a rotary tray, a magnetron for providing electromagnetic waves to the cooking chamber, a high voltage transformer for providing a high voltage to the magnetron, and a tray motor for driving the rotary tray. A cam assembly comprising: a cam assembly having at least one cam that rotates in response to a driving force of the tray motor; And a switch installed adjacent to the cam and on / off by the cam to control the power supply of the high voltage transformer.

Here, the cam assembly has a plurality of cams arranged in the axial direction on the tray motor rotation axis, each of the cams is different in the ratio of the operating zone to the switch on, so that the high voltage transformer according to the selection of each cam The on / off period is determined so that the output level can be adjusted.

In addition, a plurality of switches are provided to correspond to the cams, and the switch is provided as a micro switch that comes in contact with the corresponding cam in the action section of each cam, so that the power supply to the high voltage transformer can be easily controlled electrically. have.

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

As shown in FIG. 1, the mechanical microwave oven has a main body 1 having a cooking chamber 4 and a component chamber 7, and an outer casing 3 surrounding the upper side and both sides of the main body 1. In the cooking chamber 4, a rotary tray 6 on which food is placed is accommodated, and a door 5 is provided in the front opening of the cooking chamber 4 so as to be able to rotate and open. The component chamber 7 houses a magnetron 10 for generating electromagnetic waves, and a high voltage transformer 9 for supplying a high voltage to the magnetron 10. An operation panel 30 is provided in front of the component chamber 7. Is equipped.

The operation panel 30 has a rectangular cylindrical casing 31 with a rear opening. The panel casing 31 includes a time setting knob 32 using a timer for setting a cooking time, and for selecting an output level. An output adjustment knob 33 is mounted.

Meanwhile, as shown in FIG. 2, a tray motor 16 for driving the rotary tray 6 is installed below the cooking chamber 4, and the rotating shaft 17 of the tray motor 16 is a cooking chamber ( It extends through the bottom surface of 4) to the center area of the rotary tray 6. The tray motor 16 is installed to operate in conjunction with the tray motor 16, an output control device 20 for regulating the power supply to the high voltage transformer 9 to regulate the output of the magnetron 10.

As shown in FIGS. 3 and 4, the output adjusting device 20 includes a plurality of cams 22a and 22b installed on the rotary shaft 17 of the tray motor 16 and integrally rotating with the tray motor 16. To correspond to each cam 22a, 22b, 22c, 22d to be turned on and off according to the rotation of the cam assembly 21 and the cam assembly 21 having the It includes a plurality of output switches (25a, 25b, 25c, 25d) fixed to the tray motor 16. Here, the output switches 25a, 25b, 25c, and 25d are arranged in parallel on the circuit of the microwave oven so as to act independently of each other.

A plurality of cams 22a, 22b, 22c, and 22d of the cam assembly 21 are formed integrally along the longitudinal direction of the rotation shaft 17, and each cam 22a, 22b, 22c, 22d is formed in a circumferential direction. As a result, a non-operation section in which the output switches 25a, 25b, 25c, and 25d are turned off, and an operation section in which the radius is larger in diameter than other regions are formed so that the output switches 25a, 25b, 25c, and 25d are turned on. Here, the circumferential widths of the working sections of the cams 22a, 22b, 22c, and 22d are different, and each of the cams 22a, 22b, 22c, and 22d has a ratio of 70%, 50%, and 30% to the working sections. , 15% is formed. That is, when the cam 22a having a 70% working period is operated, the on time of the magnetron 10 becomes 70% during the entire cooking time, and when the cam 22c having a 30% working period is operated, During the cooking time, the magnetron 10 is turned on for 30% of the time.

The output switches 25a, 25b, 25c, and 25d provided on the sides of the cams 22a, 22b, 22c, and 22d of the cam assembly 21 are formed of micro switches for intermittent power supply to the high voltage transformer 9. It is. Each output switch 25a, 25b, 25c, 25d receives a separate power supply, and interrupts the power supply to the high voltage transformer 9 during power supply.

By this configuration, when the user selects the output level as 50% by the output adjustment knob 33, power is supplied to the output switch 25b corresponding to the cam 22b whose output level is 50%. When the cooking time is set by the time setting knob 32, the tray motor 16 operates, and the cam assembly 21 rotates simultaneously with the operation of the tray motor 16. At this time, by means of the cam 22b having an output level of 50%, the corresponding output switch 25b is turned on in the operating section of the cam 22b and off in the non-operating section to interrupt the power supply to the high voltage transformer 9. do. That is, the power is supplied to the high voltage transformer 9 only for 50% of the time during which the rotary shaft 17 of the tray motor 16 turns, so that the electromagnetic wave only enters the cooking chamber 4 for 50% of the time. Will be supplied.

Similarly, when the cams 22a, 22c, and 22d having the ratio of the working ranges of 70%, 30%, and 15% are selected, they operate in the same manner to control output. On the other hand, in order to adjust the output so that the magnetron 10 is operated throughout the cooking time, a separate switch is provided in parallel with each output switch and does not contact the cam. When the output level with 100% output is selected, the switch is turned on immediately so that power can be continuously supplied to the high voltage transformer 9 so that the output can be adjusted to 100%.

On the other hand, in the above-described embodiment, although the power to the high voltage transformer 9 is interrupted by using a micro switch, an output switch having a pair of contact plates is installed in a region adjacent to the cam assembly 21 as in the prior art, and the cam assembly is installed. An actuating lever is provided between the 21 and the output switch in contact with the circumferences of the cams 22a, 22b, 22c and 22d to contact and space the contact plates of the output switch. Then, the rotating lever is provided with a rotating shaft parallel to the axis of the cam assembly 21, and the lifting shaft is provided with lifting means for raising and lowering the operating lever in accordance with the external output selection. Accordingly, according to the external output selection, the working lever can be raised and lowered to contact the cams 22a, 22b, 22c, and 22d to mechanically turn the output switch on and off to adjust the output.

As described above, in the present invention, the structure of the output adjusting device 20 is simplified by providing the tray motor 16 with the output adjusting device 20 using the cams 22a, 22b, 22c, 22d and the micro switch. In addition, in the related art, as a plurality of gears are used to transmit rotational force between the timer gear and the output gear, the assembly work is cumbersome and the defective rate is high due to the minute error management between the gears, but the cams 22a, 22b, 22c, By assembling microswitches or output switches 25a, 25b, 25c, and 25d directly on the outer circumferential surface of 22d), the assembling work is simplified.

As described above, according to the present invention, it is possible to simplify the structure of the output control device to reduce the defective rate and facilitate the assembly operation.

Claims (3)

In a microwave oven having a cooking chamber provided with a rotary tray, a magnetron for providing electromagnetic waves to the cooking chamber, a high voltage transformer for providing a high voltage to the magnetron, and a tray motor for driving the rotary tray, A cam assembly having at least one cam that rotates in response to a driving force of the tray motor; And a switch installed adjacent to the cam and on / off by the cam to control the power supply of the high voltage transformer. The method of claim 1, The cam assembly has a plurality of cams disposed along the axis of rotation of the tray motor in the axial direction, wherein each of the cams is different in the ratio of the operating zone is the switch is turned on. The method of claim 1, A plurality of switches are provided so as to correspond to each of the cams, the microwave oven, characterized in that the micro switch is turned on in contact with the corresponding cam in the action section of each cam.