JP2537880B2 - High frequency heating equipment - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating device such as a microwave oven in which heating conditions are automatically determined based on the shape, weight, etc. of an object to be heated.

2. Description of the Related Art In recent years, high-frequency heating devices, especially microwave ovens, have been equipped with various types of sensors such as temperature sensors, humidity sensors, and weight sensors for the purpose of realizing automatic cooking. The sequence is selected. One of the important pieces of information for such automatic cooking is the density of food. For example, when vegetables are considered as food, if attention is paid to the density, it is possible to classify root vegetables, fruit and vegetables, leaf vegetables, etc. with relatively high accuracy, which can be useful information for automatic cooking. . To find the density of food or a parameter close to density,
It is necessary to know the general shape of the food together with the information from the weight sensor.

Conventionally, as one means for recognizing the general shape of food, there is a method in which ultrasonic waves are horizontally emitted to the food from the side.

Hereinafter, with reference to the drawings, a method for recognizing the general shape of the conventional food described above will be described.

FIG. 4 is a diagram showing a conventional example of a method for recognizing the shape of food. In FIG. 4, 1 is a magnetron, 2
Is a waveguide, 3 is a heating chamber, 4 is a rotary plate, 5 is a drive unit for rotationally driving the rotary plate 4, 6 is food, 13 is a magnetron drive control unit for driving and controlling the magnetron 1, and 14 is CPU for controlling each control unit, 15 is an ultrasonic transducer, and is attached to the side wall of the heating chamber 3
On the other hand, it functions as an element that oscillates an ultrasonic arus and receives a reflected wave from the side wall surface of the food 6 or the heating chamber 3. Reference numeral 16 denotes an ultrasonic wave transmission / reception control unit which receives a control signal from the CPU 14 and supplies a transmission pulse to the ultrasonic wave oscillator 15, and amplifies the reflected wave returned to the ultrasonic wave oscillator 15 and transfers it to the CPU 14.

The operation of the high-frequency heating device configured as above will be described. The food 6 is placed on the rotary plate 4 and rotated by the drive unit 5. The CPU 14 sends a control signal to the ultrasonic wave transmission / reception control unit 16 in a short cycle, and in response to this, the ultrasonic wave transmission / reception control unit 16 intermittently drives the ultrasonic transducer 15 for each minute rotation angle of the food 6. The ultrasonic waves transmitted from the ultrasonic vibrator 15 propagate horizontally in the direction of the central axis of the rotary dish 4 and are reflected by the surface of the food 6. The reflected wave is an ultrasonic transducer
After being received by 15 and amplified by the ultrasonic transmission / reception control unit 16,
A control signal indicating that the reflected wave has been received is sent to the CPU 14 by comparison with an appropriate threshold voltage. CPU14
Counts the time from the transmission of ultrasonic waves to the reception of reflected waves, and recognizes the rough shape of the food 6 based on this data.
Based on the recognition result and information from another sensor (not shown), the CPU 14 selects the genre classification of the food 6 and the optimum cooking sequence, and controls the output of the magnetron 1 by the magnetron drive control unit 13.

FIG. 5 shows an example of the result obtained after data processing. The horizontal axis represents the weight of the food and the vertical axis represents the approximate volume.
An example of food is cabbage. The distribution width is wide.

Problems to be Solved by the Invention However, in the above-described configuration, the shape of the food causes the transmitted wave to be reflected in a direction different from that of the receiving unit, and thus the receiving unit does not return within a certain period of time. It was Therefore, there is a problem that the data in that portion is deficient and the accuracy deteriorates.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a high-frequency heating device capable of accurately recognizing a food shape without changing a simple configuration.

Means for Solving the Problems In order to solve the above problems, the high-frequency heating apparatus of the present invention has an ultrasonic transducer mounted on the side wall surface of the heating chamber in a downward direction of 5 ° to 20 ° with respect to the horizontal plane, or A hole is formed on the side wall of the heating chamber to serve as an ultrasonic path, and a reflector is installed to place an ultrasonic transducer outside the heating chamber. Installed so that it is guided into the heating chamber in the same direction, the time until the ultrasonic waves are reflected by the object to be heated or the wall of the heating chamber and received by the ultrasonic transducer is measured. It is configured to include means for recognizing the shape of the heated object.

Action The present invention, by the above configuration, while intermittently irradiating the food with ultrasonic pulses in a short cycle during the rotation of the food by the rotating dish and the reflected wave from the food, in some cases the reflected wave from the heating chamber wall surface To receive. At that time, by irradiating the ultrasonic pulse downward from the horizontal plane by 5 to 20 degrees,
Due to the shape, the reflected wave that cannot be received is reflected by the bottom surface to become the reflected wave that can be received, so that the reception rate is improved. Therefore, the accuracy is improved. The presence / absence of food and the distance between the ultrasonic transducer and the food are measured from the accurate transmission / reception time difference, and the rough shape of the food is recognized based on these data.

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

FIG. 1 shows a high frequency heating apparatus according to the first embodiment of the present invention. In FIG. 1, 1 is a magnetron, 2 is a waveguide, 3 is a heating chamber, 4 is a rotary dish, 5 is a drive unit, 6 is food, 13 is a magnetron drive control unit, 14 is a CPU, 16 is an ultrasonic wave transmitter / receiver. In the control unit, these are the same as in the conventional example. Reference numeral 17 denotes an ultrasonic transducer, which is attached to the side wall surface of the heating chamber 3 so as to face downward by 5 ° to 20 ° with respect to the horizontal plane and oscillates an ultrasonic pulse with respect to the food 6 or the food 6 or
It functions as an element that receives a reflected wave from the wall surface of the heating chamber 3.

The operation of the high-frequency heating device configured as above will be described. The food 6 is placed on the rotary plate 4 and rotated by the drive unit 5. The CPU 14 sends a control signal to the ultrasonic wave transmission / reception control unit 16 in a short cycle, and in response to this, the ultrasonic wave transmission / reception control unit 16 intermittently drives the ultrasonic transducer 15 for each minute rotation angle of the food 6.

The ultrasonic wave transmitted from the ultrasonic transducer 15 propagates in the direction of the central axis of the rotary dish 4 at a downward angle of 5 ° to 20 ° with respect to the horizontal plane, and is reflected by the surface of the food 6. The reflected wave is received by the ultrasonic transducer 15. Also, even for those that do not receive reflected waves, the reflected waves that are further reflected on the bottom surface are received,
The reception rate is improved. Further, these reflected waves are amplified by the ultrasonic wave transmission / reception control unit 16, and then compared with an appropriate threshold voltage, a control signal indicating that the reflected waves have been received is sent to the CPU 14. The CPU 14 counts the time from the transmission of ultrasonic waves to the reception of reflected waves, and accurately recognizes the rough shape of the food 6 based on this data. Based on this recognition result and information from another sensor (not shown), the CPU 14 selects the genre classification of the food 6 and the optimum cooking sequence, and controls the output of the magnetron 1 by the magnetron drive control unit 13.

FIG. 2 is an example of a schematic shape recognition result obtained after data processing. The horizontal axis is the weight of the food, and the vertical axis is the approximate volume. An example of food is cabbage. The distribution width is narrow and the approximate volume is required with high accuracy.

FIG. 3 is a cross-sectional view of the main parts of a high frequency heating apparatus showing a second embodiment of the present invention.

3 is different from FIG. 1 in that a hole 18 is provided in the side wall surface of the heating chamber 3 and an ultrasonic wave is transmitted from the reflecting plate 19 to the heating chamber 3 in a downward direction of 5 ° to 20 ° with respect to the horizontal plane. Ultrasonic transducer installed outside the heating chamber 3
The ultrasonic pulse transmitted to 15 transmits the food 6 through the reflector 19.
Is the point that is guided to. With such a configuration, the ultrasonic vibrator 15 can be protected from oil and dirt, and further, in the microwave oven or the like, it can be prevented from being deteriorated in characteristics, sensitivity, etc. by being placed directly under high temperature.

In the embodiment shown in FIGS. 1 and 3, one ultrasonic transducer 15 is provided, but two or more ultrasonic transducers 15 are provided in order to perform three-dimensional shape recognition in consideration of information in the height direction. The configuration may be different. In addition, each ultrasonic transducer 15 is connected to the heating chamber 3
May be attached to different side wall surfaces.

According to the present invention, at least one ultrasonic transducer is directly attached to the side wall surface of the heating chamber with a downward direction of 5 ° to 20 ° with respect to the horizontal plane, or a hole is formed in the side wall surface of the heating chamber. , A reflector is installed so as to propagate ultrasonic waves downward 5 ° to 20 ° to the horizontal plane to the heating chamber, and an ultrasonic transducer is used so that ultrasonic waves are propagated into the heating chamber via this reflector. Attached to the outside of the heating chamber, while the food placed on the rotating dish is rotating, ultrasonic waves are transmitted to the inside of the heating chamber at a very short cycle compared to the rotation cycle, and with the reflected waves from the food and the side wall surface. Depending on the shape, the reflected wave from the food that cannot be received is received as the indirect reflected wave through the bottom surface. As a result, it is possible to realize a high-frequency heating device capable of selecting a cooking method together with information from other sensors by enabling the rough shape recognition of food having a narrow distribution width, that is, with higher accuracy.

[Brief description of drawings]

FIG. 1 is a sectional view showing the main part of a high frequency heating apparatus according to an embodiment of the present invention, FIG. 2 is a characteristic diagram showing a result of shape recognition according to the present embodiment, and FIG. 3 is a second embodiment of the present invention. FIG. 4 is a cross-sectional view of a main part showing an example high-frequency heating device, FIG. 4 is a cross-sectional view of a main part showing a conventional high-frequency heating device, and FIG. 5 is a characteristic diagram showing a result of shape recognition according to the conventional example. 1 ... Magnetron, 2 ... Waveguide, 3 ... Heating chamber, 4
...... Rotating plate, 5 …… Drive unit, 6 …… Food, 13 …… Magnetron drive control unit, 14 …… CPU, 15,17 …… Ultrasonic transducer, 16 …… Ultrasonic transmission and reception control unit, 18 ・ ・ ・… Hole, 19 …… Reflector.

 ─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-51-147041 (JP, A) JP-A-61-187606 (JP, A) JP-A-62-46282 (JP, A) Special table Sho-60- 501874 (JP, A)

Claims (2)

(57) [Claims] 1. A heating chamber, a high-frequency oscillator, a rotary plate on which an object to be heated is placed, and a drive unit for rotating the rotary plate, and at least one ultrasonic transducer is provided on a side wall surface of the heating chamber. Is attached downward from the horizontal plane by 5 ° to 20 °, and the ultrasonic waves emitted from the ultrasonic transducer are reflected by the object to be heated or the wall surface of the heating chamber to cause the ultrasonic vibration. A high-frequency heating device comprising a means for measuring the time until the child receives it and recognizing the shape of the object to be heated based on the measurement data. 2. A heating chamber is provided with at least one hole in the side wall surface thereof, and at least one reflecting plate is attached so that ultrasonic waves can be emitted downward at 5 ° to 20 ° with respect to a horizontal plane. The high-frequency heating device according to claim 1, wherein the high-frequency heating device is arranged outside the heating chamber, and transmits / receives ultrasonic waves through the reflection plate.