JPS63105492A - Heater - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention aims to automate heating equipment by recognizing the shape of objects to be heated.
The present invention relates to a heating device realized by detecting the progress of heating.

The conventional automatic high-frequency heater disclosed in Japanese Unexamined Patent Publication No. 50-152334 detects the size v'ff of the object to be heated using a wave detector and automatically sets the heating time.

This is the size of the load on the heated object, equivalent to water V (g
)'t, the heating time proportional to 7X (Te - Ts') is calculated from the initial temperature Ts' detected by the wave detector placed in the auxiliary waveguide, the manually set initial temperature Ts', and the finished temperature Te. This automatically controls heating.

The magnitude V of the object to be heated as a load is realized by detecting a part of the heating radio waves.

Problems to be Solved by the Invention However, in such conventional automatic heating methods, the size of the object to be heated is estimated from the degree of O matching between the magnetron, the load, and the object to be heated is estimated to be heavy in terms of impedance to the magnetron. The light weight of the heated object is detected, and the size of the heated object can also be determined from this, and the volume of the object to be heated is not actually detected.

Moreover, the high frequency current detected by the detector varies significantly depending on the temperature of the magnetron, and the size of the object to be heated, V, in terms of water, is not stable. In other words, even if the object to be heated is the same size, the high frequency current increases when it is cold, and as the magnetron is used repeatedly, the magnetron warms up, the high frequency current decreases, and the size of the heated object is detected to be smaller.

In view of this background, the present invention detects the actual volume of the object to be heated, optimizes the factors that determine the heating time of the finish sensor based on this, and attempts to automatically heat a wide range of objects with a few keys. It is something to do.

Means for Solving the Problems In order to solve the above problems, the present invention provides an ultrasonic sensor to detect the distance to the object to be heated, thereby determining the shape of the object to be heated. The aim is to automatically heat a wide range of objects with just a few keys by optimizing all the factors that determine the heating time of the finishing sensor.

Function: In the heating device of the present invention, the ultrasonic sensor detects the distance to the object to be heated. The control unit determines the shape of the heated object from this distance data and estimates the type of the heated object. Based on this estimation, the factors that determine the heating time of the finished senna, ie, the detection threshold and the additional heating time constant, are set, and the power supply to the heating means is fully controlled.

EXAMPLE Hereinafter, a heating device according to an example of the present invention will be explained 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 freely openable and closable, and an operation panel 3 is provided. A keyboard 4 is arranged on this operation panel 3.

FIG. 1 is a block diagram showing the configuration of such a heating device. Operation commands input from the keyboard 4 on the operation panel 3 are decoded by the control section 5. Then, the control unit 6 uses the ultrasonic sensor 6 to measure the distance to the object to be heated.

Since the distance from the ultrasonic sensor to the rotating mounting table is constant,
If the object to be heated is below the ultrasonic sensor, the reflection returns to the ultrasonic sensor quickly. The height of the object to be heated can be determined by the difference.

That is, the height of the object to be heated is calculated from 11-H-d h□Height of the temporarily heated object H□Distance to the rotary mounting table d□Detected distance.

Now, when the rotary mounting table 8 in the heating chamber 7 starts rotating in this state, the relative positional relationship between the object to be heated 9 and the ultrasonic sensor 6 changes. Then, the height data of the object to be heated is inputted to the control section, and from this data the control section can detect the entire rotating section of the object to be heated, and from this, the entire size and volume of the object to be heated can be estimated.

Next, in this example, in order to further find the total power of the heated object,
A weight sensor 10 provided below the rotary mounting table is used to detect the total weight of the object to be heated. As the weight sensor 10, one that detects the displacement amount of the rotary mounting table 8 using a capacitance method or a strain gauge method, or a vibration method that measures the natural frequency of the mounting table using a magnet and a coil, etc. can be adopted. Mo°-Evening 11
is a drive source that rotates the rotary mounting table 8.

The ultrasonic sensor inputs data to the control unit via the detection circuit 12, and the weight sensor inputs data to the control unit via the detection circuit 13.

FIG. 3 shows a narrow ultra-directional ultrasonic microphone as an example of an ultrasonic sensor. The ultrasonic sensor is a piezoelectric element 143
Conical resonator 15. Terminal 16. Beam shaping plate 1, case 1B, lead wire 19. Connection shaft 20. Terminal board 21. It consists of a sound absorbing sheet 22. (National Technical Report P, 504-614 Vol. 29
7a3AN FIG. 4 shows the volume of a heated object being detected using such an ultrasonic sensor. The horizontal axis represents the position and rotation angle (t) of the rotary mounting table, and the vertical axis represents the height of the object to be heated. Therefore, the continuous data of the height of the heated object detected at each position on the mounting table (shaded area) represents the rotational cross section of the heated object, and the ultrasonic sensor is installed at the position (1). If the value) is selected appropriately, the shape of the entire object to be heated can be estimated.

Based on the shape of the heated object detected by the ultrasonic sensor, the optimal detection threshold and additional heating time constant can be set according to the shape and size.

Now, Figure 4 shows the data for spinach and potatoes, but as it is clear from the figure, if the weights are the same,
There are considerable differences between the two. In other words, if the weight and volume can be detected, then in the case of vegetables, it is possible to detect leafy vegetables (
You can tell whether it is a spinach) or a root vegetable (potato). η) Based on this determination, the control unit 5 can also estimate the type of the object to be heated.

Next, the control unit 5 sets factors for determining the heating time using the finish sensor 27 based on the results of the above determination, and starts supplying power to the heating means 26 by activating the driver 26 .

When heating is started, the cooling fan 28 rotates to cool the magnetron serving as the heating means 26, and at the same time, cooling air is introduced into the heating chamber via the intake guide 29 to ventilate the heating chamber. A humidity sensor serving as a finish sensor 27 is provided in the exhaust guide 3o to detect steam generated from the object to be heated. 31 is a detection circuit of a humidity sensor.

FIG. 5 is a time chart showing the procedure for automating such heating. First, in the first shape determination cycle PD, the rotary mounting table rotates and the size of the object to be heated is detected. During this time, the microwave is turned off. Through this shape determination, the shape or type of the object to be heated is determined, and the additional heating time constant K is selected.

Next, microwaves are irradiated and heating of the object to be heated is started. When steam exceeding a certain detection threshold ΔH is detected by the humidity sensor, the additional heating time KT1 is calculated by multiplying 1 by the above-mentioned additional heating time constant K by the required time, and this is counted. Heating continues until

In this embodiment, the additional heating time constant is made variable by shape recognition, but of course the detection threshold ΔH (
A similar effect can be obtained by changing the shape by i-shape recognition.

Now, FIG. 6 is a block diagram showing an example of the configuration of a detection circuit of an ultrasonic sensor.

The control unit 6 is composed of a microcomputer or the like, and performs timing control so that one ultrasonic sensor transmits an ultrasonic wave of several tens of KHz, and when receiving, it is switched to a receiver and operates.

32 is a transmitting circuit, and 33 is a receiving circuit. Comparison circuit 34
compares the reference voltage with the received signal, latches the received signal exceeding the reference voltage, and inputs it to the control section 5. The control unit 5 counts the time from transmitting the ultrasonic waves to receiving them, calculates the distance to the object to be heated from the propagation velocity of the ultrasonic waves, and calculates the height of the object from this.

The detection circuit and control method for a weight sensor can be realized, for example, in Japanese Patent Application No. 60-264051, and the detection circuit and control method for a humidity sensor, which is a finishing sensor, can be realized in, for example, Japanese Patent Application Laid-Open No. 51-134951. can.

With the above configuration, it is possible to accurately recognize the shape of the object to be heated, and it is possible to control the finish sensor appropriately, and automatically heats the object according to the shape and estimated type of the object to be heated. can do.

Effects of the Invention As described above, the heating device of the present invention is equipped with an ultrasonic sensor and a finish sensor, and detects the shape of the object to be heated by the ultrasonic sensor, estimates the type of the object, etc. This configuration sets the factors that determine the heating time to optimal values, and can automatically heat a wide range of objects with just a few keys.

Furthermore, since an ultrasonic sensor is used as a shape recognition sensor, it is much cheaper and more resistant to dirt than optical sensors such as cameras and CODs that are commonly used. In heating devices such as microwave ovens, the heating chamber gets quite dirty with oil, and the sensors installed in these devices usually require measures such as burning off the dirt with a heater, but if it is a drip-proof ultrasonic sensor, the element It is impossible for the material itself to change physically or chemically over time due to dirt, so there is no need for such consideration.

As described above, according to the present invention, heating of a wide variety of objects to be heated can be automated with a small number of keyboards, and good heating can be achieved with simple operations.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of a heating device according to an embodiment of the present invention, Fig. 2 is a perspective view of the main body, Fig. 3 is a sectional view of a narrow directional ultrasonic sensor, and Fig. 4 is an ultrasonic sensor. A waveform diagram showing the height data of the heated object detected by the sensor, Fig. 5 is a time chart showing the heating automation procedure, and Fig. 6 is a circuit block showing a configuration example of the detection circuit of the ultrasonic sensor. It is a diagram. 6...Control unit, 6...Ultrasonic sensor,
7... Heating chamber, 9... Heated object, 1o
... Weight sensor, 26 ... Heating means,
27...Finishing sensor. Name of agent: Patent attorney Toshio Nakao and one other person
2 Figure? Figure 3 Figure 4 1 = 80 - Food weight = σpi turntable 11@(') Figure 5

Claims (1)

[Claims] a heating chamber in which an object to be heated is placed; a heating means coupled to the heating chamber; a control section controlling power supply to the heating means; an ultrasonic sensor detecting the shape of the object to be heated; The controller includes a finish sensor that detects the progress of heating of the object to be heated, and the control section uses the ultrasonic sensor to detect the distance from the ultrasonic sensor to the object to be heated, thereby determining the shape of the object to be heated. A heating device characterized in that the heating device is configured to determine a factor for determining a heating time using the finishing sensor based on the determination, and to control power supply to the heating means.