JPH07103998B2 - Heating device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes a door body that opens and closes an opening of a heating chamber,
Further, the present invention relates to a heating device including a rotary mounting table that heats an object to be heated while rotating the object.

2. Description of the Related Art In order to improve heating unevenness of an object to be heated, a rotary mounting table is installed in a heating chamber, and a heating device of a system for heating an object to be heated while rotating, for example, a microwave oven equipped with a turntable is used. In the equipment, there are already many inventions and inventions which make it easy to take out the object to be heated by stopping the rotary mounting table at a predetermined position when the heating is completed.

As an example, in Japanese Utility Model Laid-Open No. 56-45715, a cam mechanism that moves in tandem with a turntable is provided, and an electric contact or an optical contact that is turned on / off by the cam mechanism or a magnetic contact is used. The position of the turntable is detected, and the turntable is configured to be the same before and after cooking.

Further, in JP-A-60-185391, the turntable is stopped at a specific position by a magnetic field generating means attached to a part of the lower surface of the turntable and a detecting means for detecting the position of the magnetic field generating means. The invention is disclosed.

Problems to be Solved by the Invention As described above, the conventional stop device for the rotary mounting table detects the position of the rotary mounting table and stops it at a specific position.

However, with such a stopping device, depending on where the object to be heated is placed on the door at the start of heating, the rotary mounting table does not always stop at a position where the object to be heated can be easily taken out. It can be said that the method is effective only when the operator of the heating device adheres to the constraint that the object to be heated is placed at a specific position, for example, in front of the door body, at the start of heating.

Even if the object to be heated is placed in front of the door, if part of it is placed outside the rotary mounting table, the protruding part touches the heating chamber wall due to rotation of the rotary mounting table. The position of the object to be heated may be greatly deviated.

In view of such a background, the present invention, no matter what position the object to be heated is placed with respect to the door at the start of heating, when the door is always opened, the rotary mounting table is stopped at a specific position where the object to be heated is easily taken out. The present invention is intended to realize a heating device that does.

Means for Solving the Problems In order to solve the above problems, the present invention provides a control unit that controls power supply to a heating unit, a position detection sensor that detects a position of an object to be heated, and a door body opening / closing. And a means for detecting.

The heating device of the present invention, when the door opening operation is detected by the means for detecting the opening / closing of the door body, or when the stop of heating is detected by the control unit, the position detection sensor heats the rotary table. The position of the object is detected, and the rotary mounting table is stopped so as to reach a specific position where the object to be heated can be easily taken out from the door body.

Example Hereinafter, a heating device according to an example of the present invention will be described with reference to the drawings.

FIG. 2 is a perspective view of the main body of the heating device according to the present invention.
A door body 2 is pivotally supported on the front surface of the main body 1 so as to be openable and closable, and an operation panel 3 is provided. On the operation panel 3, a keyboard 4 for instructing power supply to the heating means is arranged, and heating time, output, etc. are input.

FIG. 1 is a block diagram showing the configuration of such a heating device. The heating command input from the keyboard 4 is sent to the control unit 5
Decrypted by Then, the control unit 5 detects the position of the object to be heated 8 placed on the rotary mounting table 7 in the heating chamber 6 by using the position detection sensor 9. Reference numeral 10 is a drive means for driving the rotary mounting table.

In this embodiment, an ultrasonic sensor is used as the position detection sensor 9, and the ultrasonic sensor is installed on the ceiling of the heating chamber 6 so as to be eccentric to the rotation axis of the rotary mounting table 7. With this configuration, the ultrasonic sensor serving as the position detection sensor 9 detects the distance a from the ceiling to the object to be heated 8.

Now, assuming that the constant distance from the ceiling of the heating chamber 6 to the rotary mounting table 7 is D and the height of the heated object 8 is h, the distance a to the heated object 8 detected by the position detection sensor 9 is a. Is expressed by the following equation.

a = D−h That is, only when the heated object 8 comes under the position detection sensor 9, reflection by the heated object 8 occurs and the detection distance a becomes short. When the object 8 to be heated moves away from below the position detection sensor 9, the detection distance a comes to show a constant value D.

FIG. 3 (a) is a time chart showing such a state. The vertical axis is the detection distance a and the horizontal axis is the originally elapsed time,
If the drive means 10 is a synchronous motor, the rotary mounting table 7 rotates at a constant speed, so the control unit 5 can regard the passage of time as the relative position of the rotary mounting table 7 with respect to the door body 2. The elapsed time can be regarded as a rotation angle with respect to a certain origin. FIG. 3B is a top view of the rotary mounting table 7 showing this relationship.

Therefore, the control unit 5 can detect that the object 8 to be heated is present during the period from the rotation angle A at which reflection occurs to the rotation angle B.

Now, returning to FIG. 1, means 11 for detecting opening / closing of the door body 11
Notifies the control unit 5 of the door opening operation of the door body 2. Control unit 5
When the door opening operation is detected, or when the timer means in the control unit 5 stops or ends the power supply to the heating means 12, the position detecting sensor 9 is used to make the rotary mounting table. The position of the object 8 to be heated on 7 is detected,
A specific position where the object to be heated 8 can be easily taken out from the door body 2,
For example, the drive means 10 is controlled so as to come to the front side of the door body 2, and the rotary mounting table 7 is stopped.

A switch or the like is used as the means 11 for detecting the opening / closing of the door body 2, and a magnetron or the like is used as the heating means 12. Reference numeral 13 is a driver that controls power supply to the heating means 12, 14 is a detection circuit of the position detection sensor 9, and 15 is a driver of the drive means 10.

Next, as the position detection sensor 9, the ultrasonic sensor adopted in this embodiment will be described in detail.

FIG. 4 is a sectional view showing the structure of the ultrasonic sensor. The ultrasonic sensor includes a piezoelectric element 16 and a piezoelectric element 16 via a coupling shaft 17.
A conical resonator 18 that engages with, a terminal 20 coupled to the piezoelectric element 16 by a lead wire 19, a terminal plate 21 that fixes the terminal 20, a case 22 that forms an outer shell, and a cone of the case 22. Beam shaping plate 23 covering the opening on the side of the cylindrical resonator 18 and the terminal plate 21.
The sound absorbing sheet 24 is provided on the inner surface of the.
(National Technical Report P.504-514 Vo
Next, FIG. 5 is a block diagram showing a configuration example of the detection circuit 14 when an ultrasonic sensor is used as the position detection sensor 9.

The control unit 5 is composed of a microcomputer or the like, and by performing timing control, one ultrasonic sensor 9 which is a position detection sensor transmits an ultrasonic wave of several tens of kHz, and at the time of reception, the ultrasonic wave is transmitted to a receiver. It operates by switching.

Reference numeral 25 is a transmission circuit, and 26 is a reception circuit. The comparison circuit 27 compares the received signal with the reference voltage, latches the received signal exceeding this reference voltage, and inputs it to the control unit 5. The control unit 5 counts the time from transmitting the ultrasonic wave to receiving the ultrasonic wave, calculates the distance to the object to be heated 8 from the propagation speed of the ultrasonic wave, and detects the position of the object to be heated 8 from this.

With the above configuration, the control unit can detect the position of the object to be heated, and at the time of opening or closing the door or stopping or ending the heating, the drive unit is controlled to a specific position where the object to be heated can be easily taken out from the heating chamber. You can stop.

Next, another embodiment of the position detection sensor will be shown. FIG. 6 is a plan sectional view of a heating chamber showing an example using an optical sensor. It is the same as the embodiment shown in FIG. 1 that the opening of the heating chamber 6 is openably and closably closed by the door 2 and the rotary mounting table 7 rotationally drives the object to be heated 8. In this example, as the position detection sensor 9, an optical sensor, for example, an element such as a phototransistor whose electric characteristics are changed by receiving light from the light source 28 is used. With this configuration as well, when the heated object 8 blocks the light from the light source 28,
Like the ultrasonic sensor, the control unit can detect the position of the object to be heated 8.

EFFECTS OF THE INVENTION As described above, the heating device of the present invention includes the position detection sensor, which detects the position of the object to be heated on the rotary mounting table, and detects the opening operation of the door body based on this. Alternatively, it is possible to detect the stop of the power supply to the heating means and stop the rotary mounting table so that the object to be heated can be brought to a specific position where it can be easily taken out of the heating chamber. And since the position of the object to be heated is detected instead of detecting the position of the rotary mounting table as in the past, no matter what position the object to be heated is installed at the start of heating, the object to be heated must be Can be stopped at a position where it can be easily taken out.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a heating device according to an embodiment of the present invention, FIG. 2 is a perspective view of the main body, and FIG. 3 (a) shows distance values detected by an ultrasonic sensor which is a position detection sensor. Waveform diagram showing the transition, FIG. 3 (b) is a top view of the rotary mounting table,
FIG. 4 is a sectional view of an ultrasonic sensor as an example of a position detecting sensor, FIG. 5 is a circuit block diagram showing a configuration example of a detecting circuit of the ultrasonic sensor, and FIG. 6 is an optical circuit as another embodiment of the present invention. It is a plane sectional view of a heating chamber showing an example in which the sensor is used as a position detection sensor. 5 ... Control unit, 6 ... Heating chamber, 7 ... Rotating table, 8 ...
… Heating object, 9 …… Position detection sensor, 10 …… Driving means,
11 …… Door opening / closing detection means.

Claims (1)

[Claims] 1. A heating chamber for accommodating an object to be heated, a door for opening and closing the opening of the heating chamber, a heating means provided in the heating chamber, and a power supply to the heating means. A control unit, a rotary mounting table on which the object to be heated is mounted, a drive unit that rotationally drives the rotary mounting table, a position detection sensor that detects the position of the object to be heated on the rotary mounting table, and the door body. The opening and closing detection means for detecting the opening and closing of the door body, the control unit detects the position of the object to be heated on the rotary mounting table using the position detection sensor, the opening and closing detection means of the door body of the door body When a door opening operation is detected, or when stop of power supply to the heating means is detected by the control unit, the drive means is controlled to position the object to be heated at a predetermined position with respect to the door body. Is configured to stop the rotary mounting table so that Apparatus.