JPH059913B2 - - 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. A waveguide 3 is connected to the heating chamber 1, and a magnetron 4 is provided thereto. 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 includes a heating chamber, an oscillator that supplies radio waves to the heating chamber, a door that opens and closes the heating chamber, and an object to be heated that is placed inside the heating chamber. Weight measurement of the object to be heated to automatically determine the heating time of the object by detecting the rotating mounting table, the elastic body that supports the rotating mounting table, and the movement of the rotating mounting table or the elastic body as vibration frequency. a door arm that is linked to the opening and closing of the door, and a biasing means that engages with the door arm and biases an elastic body, and the biasing means is configured to move the door to a predetermined position as the door is closed. It has a function to release the bias when the door is closed, and the bias release position is set close to when the door closes. With this configuration, the heating time can be automatically determined without having to set the heating time each time. In addition, this configuration has the effect of generating reliable vibrations and measuring the reliable vibration frequency, thereby increasing measurement accuracy and enabling 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 1
1 is irradiated with radio waves oscillated from a magnetron (not shown) to heat the object 13 at high frequency. The object to be heated 13 is placed on the rotating plate 14.
is placed on the rotary mounting table 15. Rotating mounting table 1
5 is fitted onto a shaft 17 of a motor 16, and is driven to rotate by the motor 16. Motor 1
6 is fixed to block A18, which is connected to block B20 by a plurality of leaf springs 19, and block B20 is fixed to the bottom 21 of the main body. Block A18, block B20, leaf spring 1
9 constitutes a roberval mechanism, so that the motor 16 fixed to the block A18 moves elastically vertically up and down. A magnet 22 is provided in the block A18, and a detection coil 23 is provided opposite to the magnet 22. The motor 16 moves downward according to the weight of the object 13 to be heated. In addition, the motor 16 is connected to the heated object 1.
3 and the elasticity of the leaf spring 19. The detection coil 23 extracts the amount of displacement or 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 an arm 29 provided on the door 12. The door arm 29 slides on rollers 30 provided within the main body to smoothly open and close the door 12. 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, the cam 25 rotates, and the abutment part 24 is pushed down, so that the block A18 moves to the position shown by the two-dot chain line. When the door 12 is closed, the rotary table 15 has a step h with respect to the bottom surface of the heating chamber, but due to the movement of the block A18, 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 when the opening angle α of the door 12 becomes 20° or less, the abutting portion returns to its original position.

At this time, since there is some play between the pin 27 and the groove 28, when the concave part of the cam 25 touches the abutting part 24, the cam 25 slides down along the slope, and the cam 25 moves forward by this force by the amount of play. As it rotates, the abutment part 24 slides down the cam 25 at once. In this way, when the abutting portion 24 returns, it returns quickly. As a result, the block A18, the rotary mounting table 15, and the object to be heated 13 suddenly return upward when the door 12 is closed, and at this time vertical vibrations occur. 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. By the way, the plate spring 19 is the object to be heated 1
In order to support the considerable weight of the 3rd grade, a very strong material is used. For this reason, the cam 25 is
When the door 12 slides down all at once, a rather loud "thump" sound is emitted, but this sound occurs when the opening angle α of the door 12 is within 20 degrees, close to the door closing.
2 and the front surface of the heating chamber 11 overlap, making it almost indiscernible. Further, the door arm 29 is provided with a convex portion 29a on the sliding surface with the roller 30, so that the door opening angle α is
When the door 12 is closed within 20 degrees, the roller 30 rides over this convex portion 29a.
Since the door 12 is closed with a stronger force, the door 12 is closed all at once, and the sound of the rapid movement of the cam 25 and the contact portion 24 can be canceled out more reliably by the sound of the door 12. When the door 12 is closed, it is normal for the front surface of the heating chamber 11 to hit the door 12 and make a sound, and there is no discomfort at all.

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 dashes attached.

In FIG. 3, the door 12 is provided to be openable and closable with respect to the heating chamber, and a door arm 29' slides on rollers 30 provided on the main body to facilitate opening and closing.

The motor 16' is fixed to the block A18', and is connected to the block B2 by a plurality of leaf springs 19'.
0', and the block B20' is fixed to the bottom part 21' of the main body. A lever 26' is rotatably connected to the door arm 29', and a cam 41 is integrally provided with the lever 26', and is rotationally driven by the lever 26'. A lever B42 is in contact with the cam 41, and the lever B42 is in contact with the shaft 4.
It is rotatably supported by a pin 44 fixed to 3. 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 24' integrally constructed with the block A18', and the lever C spring 47
As a result, it is biased in a direction away from the contact portion 24'. The convex portion 29a' on the sliding surface of the door arm 29 with the roller 30 is similar to the embodiment shown in FIG.
It has the effect of attracting

FIG. 4 is a perspective view showing a part of the cam and lever of the high-frequency heating device according to the present invention.

In FIG. 4, the cam 41 is provided with a small diameter part 51 and a large diameter part 52, and the side surface 48 of the lever B42 is brought into contact with the cam 41, and the rotation of the cam 41 moves the lever B42 to the cam 4.
1 in the radial direction. The narrow diameter portion 51 is configured with a thrust surface A53, and the large diameter portion 52 is configured with a thrust surface B54 provided with a step.
An inclined surface 55 connecting the thrust surface B54 and the thrust surface B54 is provided. This thrust surface A53, thrust surface B54,
The inner surface 49 of the lever B42 comes into contact with the inclined surface 55, 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 12 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 24'.

Next, when the door 12' is opened to the half-open position,
The large diameter portion 52 of the cam 41 pushes the lever B42 outward in the radial direction. The path 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, and its tip pushes down the abutting portion 24'. As a result, the rotary mounting table (not shown) is pushed down until it is flush with the bottom surface of the heating chamber. Then, at point B, the inner surface 49 of the lever B42 moves from the thrust surface A53 to the thrust surface B54 due to the force of the lever B spring 45.

When the door 12' is fully opened, the cam 41 rotates further and the path on the cam 41 reaches point C. When the door 12' begins to close, the path makes a U-turn, but since the side surface 48 of the lever B42 slides only on the large diameter portion 52, the lever B42 does not move, and the abutting portion 24' remains pressed down. .

Then, when the door 12' is closed just before closing, the path reaches point D. Then, the inner surface 4 of lever B42
9 slides on the inclined surface 55, and when the opening angle (not shown) of the door 12' is a predetermined value of 20 degrees or less, 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. Move to A53. At the same time, the side surface 48 of the lever B42 comes off the large diameter portion 52, and the force of the lever C spring 47 causes the side surface 48 of the lever B42 to detach from the small diameter portion 52.
Move to point A of 1. At this time, the lever B42 moves quickly and quickly, and accordingly, the lever C46 also moves quickly to release the pressing part 24'. In this case, lever B42 moves from thrust surface B54 to thrust surface A.
53, the force of the leaf spring 19' and the lever C spring 47 makes a fairly loud noise, but the timing is within 20 degrees of the door closing, and the sound of the door closing immediately after that makes a very loud noise. canceled out. The function of the door arm protrusion 29a' is the same as described in the embodiment shown in FIG.

In this way, according to this embodiment, the pressing is quickly released by closing the door, so at this time, the rotating mounting table moves up and down depending on the weight of the object to be heated and the elasticity of the leaf spring. Vibration can be generated reliably. In addition, since the fast-acting mechanism is set to operate immediately before the door is closed to generate vibrations of the object to be heated, the sound generated when the quick-acting mechanism operates is canceled out by the sound of the door closing. Also, since the door is strongly retracted just before the door closes, the door is closed all at once, so the above operating noise can be reliably canceled by the door closing sound, without worrying about the operating noise of the quick-acting mechanism. By generating sufficient vertical vibration of the rotary mounting table and the object to be heated, and by detecting the frequency of this vibration with a detector, the weight of the object to be heated can be measured with higher accuracy. This has the effect that the heating time can be automatically set without having to set the heating time each time.

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

(1) 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, so it is stable, and there is no need to spill or damage objects to be heated, such as liquids. Since it can be used without a sense of stability, it has a better operational feel and is easier to use. It is also easy to clean the inside of the heating chamber.

(2) 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 can be clearly distinguished from external vibrations that may be applied depending on the installation location of the main unit, so-called noise vibrations (S/N
(the ratio becomes larger), more accurate and reliable detection can be performed.

(3) Since the operating noise generated when vertical vibration is generated can be canceled out by the door closing sound, there is no discomfort in use and the product value is high.

(4) Furthermore, since vertical vibrations of sufficient amplitude can be generated without worrying about the above-mentioned operating noise, highly accurate and stable detection can be performed.

(5) The effects of (3) and (4) above can be further improved by increasing the door retraction force near door closing.

(6) If a push-down mechanism is provided that is linked to the opening and closing of the door, such as a door switch that is linked to the door, it is easy to adjust the timing so that the control unit reads the detector signal at the same time as the door closing signal. Since it is possible to measure the moment when the amplitude is large, more accurate detection is possible, and the accuracy of weight measurement is extremely high.

(7) 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.

Furthermore, 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.

(8) Since the mechanism for pushing down the rotary device base is configured to be linked to the opening and closing of the door, the action is carried out naturally and unconsciously during the normal operation of putting in and taking out heated objects, making it easy to operate and use. Cheap.

[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 a 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 part, 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 table; a detector that detects the movement of the rotary mounting table or the elastic body as a vibration frequency and measures the weight of the heated object in order to automatically determine the heating time of the heated object; A door arm that is linked to the opening and closing of the door, and a biasing device that engages with the door arm and biases an elastic body, the biasing device being biased when the door comes to a predetermined position as the door is closed. A high-frequency heating device that has a function to release the energization, and the energization release position is set close to when the door closes. 2. The high-frequency heating device according to claim 1, wherein the door closes with a stronger force when the door approaches closing.