JPH0310848B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high frequency heating device such as a microwave oven.

Conventional Structure and Its Problems FIG. 1 is a sectional view showing the structure of a conventional high-frequency heating device. In FIG. 1, a door 2 is provided at the front of a heating chamber 1 so as to be openable and closable. Heating chamber 1
A waveguide 3 is connected to the waveguide 3, and a magnetron 4 is provided to the waveguide 3. Radio waves oscillated from the magnetron 4 are irradiated into the heating chamber 1 via the waveguide 3.
The object to be heated 5 is placed on a rotating plate 6, and is rotated by a motor 7 during heating to uniformly heat the object. In this way, the object to be heated 5 is heated by radio waves, but according to such a conventional high-frequency heating device, the user can set the heating time according to the amount and weight of the object to be heated 5 using a time switch or the like. It was a pain to have to set it up each time.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to measure the weight of an object to be heated and to automatically heat the object without setting a heating time. The purpose of this invention is to further improve the measurement accuracy in this weight measurement.

Structure of the Invention In order to achieve the above object, the high-frequency heating device of the present invention supports a rotating mounting table with an elastic body, and uses a detector to detect the frequency of vertical vibration of the rotating mounting table when an object to be heated is placed thereon. The weight of the object to be heated is measured by the detection, and the heating time is automatically determined without having to set the heating time each time. Then, a push-down mechanism is provided that is linked to the opening and closing of the door.
When the door is open, the rotary mounting table is pushed up, and when the door is closed, it is quickly returned to its original position, and this action activates the vertical vibration of the rotary mounting table. This configuration has the effect of generating reliable vibrations and measuring the reliable vibration frequency to improve measurement accuracy and enable stable heating with a more stable heating time.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a partial sectional view of the high frequency heating device according to the present invention. In FIG. 2, a door 12 is provided at the front of the heating chamber 11 so as to be openable and closable. Heating chamber 11
Radio waves oscillated from a magnetron (not shown) are irradiated inside to heat the object 13 at high frequency. The object to be heated 13 is placed on a rotating plate 14, and the rotating plate 14 is placed on a rotating mounting table 15. Rotating mounting table 15
is fitted to the shaft 17 of the motor 16, and the motor 1
6 for rotational driving. motor 16
is fixed to block A18, and connected to block B20 by a plurality of leaf springs 19.
Block B20 is fixed to the bottom 21 of the main body.
Since the block A18, the block B20, and the leaf spring 19 constitute a roberval mechanism, the motor 16 fixed to the block A18 moves vertically and elastically. Block A18 has magnet 22
is provided, and a detection coil 23 is provided opposite to this. The motor 16 moves downward according to the weight of the object 13 to be heated. Further, the motor 16 vibrates at a frequency depending on the weight of the object to be heated 13 and the elasticity of the leaf spring 19. The detection coil 23 extracts the vibration frequency of the magnet 22 as an electrical signal.

Further, the block A18 is provided with a contact portion 24,
A cam 25 is provided at a position opposite to this. The cam 25 is connected by a groove 28 to a pin 27 which is rotationally driven by a lever 26, and the groove 28 is made slightly wider than the pin 27 to provide a gap, so-called play. The upper end of the lever 26 is rotatably connected to a door arm 29 provided on the door 12. The door arm 29 is a roller 3 provided inside the main body.
By sliding on the 0 surface, the door 12 can be opened and closed smoothly. The door arm 29 is biased in the pulling direction by the door spring 31.
The operation of the above configuration will be explained below. When the door 12 is open, the lever 26 moves to the position shown by the two-dot chain line, the pin 27 rotates, and the cam 25
rotates and pushes down the abutting portion 24, so that the block A18 moves to the position shown by the two-dot chain line. When the door 12 is closed, the rotary mounting table 15 has a step h with respect to the bottom surface of the heating chamber, but the above-mentioned block A1
8, the rotary mounting table 15 becomes flush with the bottom surface of the heating chamber. On the other hand, when closing the door 12, the lever 26 is moved by the door arm 29, the cam 25 is rotated, and the abutment part 24 is returned to its original position.

The groove 28 provided in the cam 25 is made wider than the thickness of the pin 27, and is fitted with the pin 27 with a little margin in the rotational direction, that is, so-called rotational play. Therefore, in the operation in which the cam 25 rotates and the abutting portion 24 returns to its original position, the cam 2
When the concave portion 5 reaches the abutting portion 24, the abutting portion 24 moves along the slope of the concave portion of the cam 25, but at this time the cam 25 moves toward the pin 27.
The abutment part 24 moves the cam 25 at once without being constrained by the rotational play. In this way, when the abutting portion 24 returns, it returns quickly. As a result, the block A, the rotary mounting table 15, and the object to be heated 13 are moved to the door 12.
When it is closed, it suddenly returns upwards, causing vertical vibration. The vibration frequency generated at this time is detected by the detection coil 23 as the movement of the magnet 22, and the overall weight is measured from the output.

FIG. 3 shows another embodiment of the high-frequency heating device according to the present invention, and is an exploded perspective view showing the main components. In FIG. 3, parts that are the same as those in FIG. 2 are indicated by the same numbers with alphanumeric characters.

In FIG. 3, a door 12A is provided to be able to open and close with respect to the heating chamber, and a door arm 29A slides on rollers 30' provided on the main body to facilitate opening and closing. The motor 16A is fixed to the block A 18A, and is connected to the block B by a plurality of leaf springs 19A.
20A, and the block B 20A is fixed to the bottom 21A of the main body. A lever 26A is rotatably connected to the door arm 29A, and a cam 41 is integrally provided to the lever 26A.
It is rotationally driven by lever 26A. A lever B42 is brought into contact with the cam 41, and the lever B42 is rotatably supported by a pin 44 fixed to a shaft 43. The lever B spring 45 is a coil spring that pulls the lever B42 in the thrust direction of the cam 41. A lever C46 is fixedly provided at the other end of the shaft 43, the tip of which is opposed to the abutment part 24A integrally formed with the block A18A, and biased by a lever C spring 47 in a direction away from the abutment part 24A. .

FIG. 4 is a perspective view showing a portion of the cam and lever of the high-frequency heating device according to the present embodiment. In FIG. 4, the cam 41 is provided with a small diameter part 51 and a large diameter part 52, which are brought into contact with the side surface 48 of the lever B42, and the rotation of the cam 41 moves the lever B42 in the radial direction of the cam 41. The narrow diameter portion 51 is configured with a thrust surface A53, the large diameter portion 52 is configured with a thrust surface B54 provided with a step, and an inclined surface 55 connecting the thrust surface A53 and the thrust surface B54 is provided. This thrust surface A53, thrust surface B54, inclined surface 5
5, the inner surface 49 of the lever B42 comes into contact with the lever B42, and the lever B42 moves in the thrust direction.

The operation of the structure of the embodiment shown in FIGS. 3 and 4 will be explained below.

The sliding path of the lever B42 on the cam 41 is shown by a dashed arrow. FIG. 3 shows a state in which the door 12A is closed, and the side surface 48 of the lever B42 is in contact with the narrow diameter portion 51 due to the bias of the lever C spring 47. The path on the cam 41 is point A. In this state, the lever C46 is separated from the contact portion 24A. Next, when the door 12A is opened to the half-open position, the large diameter portion 52 of the cam 41 moves to the lever B42.
Push outward in the radial direction. The curve on the cam 41 is point B. As a result, the lever B42 rotates to the left, and this rotational force is transmitted through the shaft 43, rotating the lever C46, whose tip pushes down the abutting portion 24A. As a result, the rotary mounting table (not shown) is pushed down until it is flush with the bottom surface of the heating chamber. And the lever B42 is
At this point, the force of the lever B spring 45 causes the inner surface 4 to
9 moves from thrust surface A53 to thrust surface B54.

When the door 12A is fully opened, the cam 41 rotates further and the path on the cam 41 reaches point C. When the door 12A begins to close, the path makes a U turn, but the side surface 48 of the lever B42
Since only the lever B42 slides, the lever B42 does not move, and therefore the abutting portion 24A remains pressed down.

Then, when the door 12A is closed just before closing, the route reaches point D. Then, the inner surface 49 of lever B42
slides on the inclined surface 55, and the inner surface 49 overcomes the tensile force of the lever B spring 45 and moves from the thrust surface B54 to the thrust surface A53. At the same time, the side surface 48 of the lever B42 is removed from the large diameter portion 52 and moved to point A of the narrow diameter portion 51 by the force of the lever C spring 47. At this time, the lever B42 moves quickly and quickly, and accordingly, the lever C46 also moves quickly to release the pressing part 24A.

As described above, according to this embodiment, when the door 12 is open, the rotary mounting table 15 is pushed down, so that the rotary mounting table 15 is on the same surface as the bottom surface of the heating chamber, and the operation of loading and unloading the heated object 13 is facilitated. becomes easier. Furthermore, since the pushdown is quickly released by closing the door 12, the rotary mounting table 15 generates its own vertical vibration according to the weight of the object to be heated 13 and the elasticity of the leaf spring. By detecting this frequency with a detector, the weight of the object to be heated 13 can be measured, and the heating time can be automatically set without having to set the heating time each time. have

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) When opening the door to take out or take out the rotary plate or heated object, the rotary table is pushed down, so there is no step between the bottom of the heating chamber and the rotary table, and the same Since it can be made on a surface, it can be pulled out while sliding. If the door is designed to open from the front so that it is flush with the inner surface of the door when opened, it will be possible to smoothly pull the door out from the heating chamber to the top of the door, so if the object is heavy or hot. However, it is safer to operate and the device is easier to use.

(2) When placing a rotating plate or an object to be heated on the rotating mounting table, the rotating mounting table does not vibrate up and down, resulting in good stability, and there is no need to worry about spilling or instability of heated objects such as liquids. Since it can be used without feeling, the operation feeling is improved and it is easier to use. It is also easy to clean the inside of the heating chamber.

(3) When measuring the weight of the object to be heated by detecting the vertical vibration frequency of the object to be heated or the rotating mounting table, the rotating mounting table should return quickly when the door is closed. Due to the action of the push-down mechanism, reliable vibration is generated upon return, and a large signal can be obtained as a signal from the detector. In addition, since reliable vibration is generated, it is possible to clearly distinguish it from external vibrations that may be applied depending on the installation location of the main unit, so-called noise vibrations (the S/N ratio increases), so it is more accurate and reliable. It will be possible to detect it.

(4) A push-down mechanism linked to the opening and closing of the door allows
For example, if you install a door switch that is linked to the door, you can easily synchronize the timing so that the control unit reads the detector signal at the same time as the door closing signal, and you can measure the moment when the amplitude is large, making it more accurate. Detection is possible, and weight measurement accuracy is extremely high.

(5) By measuring the weight of the object to be heated and controlling the operation of the magnetron, which is an oscillator, via the control unit, the optimal heating time can be automatically set without having to set the heating time each time. ,
Convenient and easy to use without any hassle.

Further, if the circuit is configured to prevent so-called dry firing operation, in which the heating target is heated inadvertently without the object being heated, the apparatus becomes safer.

(6) Since the mechanism for pushing down the rotary mounting table is configured to be linked with the opening and closing of the door, the operation is carried out naturally and unconsciously during the normal operation of loading and unloading objects to be heated, making it easy to operate and use. Cheap.

(7) Since the push-down mechanism is operated by the movement of the door arm, the lever has a lever effect and can be operated with an extremely light operating force.

(8) As shown in Figures 3 and 4, by using a push-down mechanism using a lever that slides in contact with the radial direction and thrust direction of the cam,
The lever moves three-dimensionally on the cam, moves over a wide range on the cam, and has the effect of pushing down and returning quickly.
Lever B also acts as a lever, so
No concentrated force is applied to mechanical parts such as the cam and lever B, and the sliding movement on the cam moves smoothly, allowing more natural and reliable operation.

This results in a device that is easy to use, has a long life, and is highly reliable.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the structure of a conventional high-frequency heating device, Fig. 2 is a partial sectional view showing one embodiment of the high-frequency heating device of the present invention, and Fig. 3 is the main configuration of another embodiment of the same device. FIG. 4 is an enlarged perspective view showing part of the cam and lever of the device. 12... Door, 13... Heated object, 15... Rotating table, 16... Motor, 18... Block A, 19... Leaf spring, 20... Block B, 24
...Attaching portion, 26...Lever, 29...Door arm, 25...Cam, 41...Cam, 42...Lever B, 43...Shaft, 46...Lever C.

Claims (1)

[Scope of Claims] 1. A heating chamber, an oscillator that supplies radio waves to the heating chamber, a door that opens and closes the heating chamber, a rotary mounting table on which an object to be heated is placed in the heating chamber, and a rotating mounting table for placing an object to be heated in the heating chamber. An elastic body that supports a mounting base, a detector that detects movement of the rotary mounting base and the elastic body, and a push-down mechanism that operates in conjunction with the door, and the push-down mechanism operates when the door is opened. A high-frequency heating device configured with a quick-acting mechanism that returns quickly when the rotary mounting table is pushed down and the door is closed. 2. A cam that is linked to the opening and closing of the door, and a lever that slides in contact with the cam in the radial direction and the thrust direction are provided, and the lever constitutes a mechanism that pushes down the rotary mounting table, and when the door is closed, the lever 2. The high-frequency heating device according to claim 1, wherein said cam is configured to slide quickly.