JPS6359052B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a heating cooking device that can measure the weight of an object to be heated and automatically calculate heating time, output, pattern, etc. according to the weight. Configuration of conventional examples and their problems In conventional high-frequency heating devices, the weight of the object to be heated is measured using a scale, etc., and the heating time and heating output are set based on the weight using a rotary timer or output setting key. Was. Therefore, cumbersome operations such as measurement, timer setting, and heating output setting are required before starting cooking, and improvements in usability have been desired. OBJECTS OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to improve usability by providing a measuring function to an apparatus. Purpose of the Invention The present invention provides a heating chamber for storing an object to be heated, a heating means such as a high frequency oscillator that supplies heating energy such as high frequency energy to the inside of the heating chamber, and a vibration frequency that changes depending on the weight of the object to be heated. The apparatus is equipped with a circuit that calculates the weight of the object to be heated from the vibration frequency by magnetically transmitting the frequency of the oscillation of the apparatus to the outside of the heating chamber. A circuit for controlling the output and oscillation time of the high-frequency oscillator is installed in the high-frequency heating device, which simplifies the operation of the high-frequency heating device and improves its usability. This eliminates the need for weighing before cooking and enables efficient cooking. DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a perspective view of a microwave oven, which is a high-frequency heating device. 1 is a display section that displays the weight of the object to be heated and the heating time; 2 is a setting section that has various keys for selecting the type of cooking, heating output, and starting cooking; and 3 is for heating chamber 5. This is a door that can be opened and closed to take food in and out, and 4 is the main body. In FIG. 2, 6 is a magnetron that supplies high frequency waves to the heating chamber 5, and 7 is food as an object to be heated. Reference numeral 8 denotes a rotatable table device on which food is placed, which vibrates at a frequency corresponding to the weight of the food 7 and transmits the vibration to the outside of the heating chamber using magnetism. 11
is a magnetic field strength detection unit such as a Hall element that detects transmitted vibrations. 9 and 15 are for applying rotational force by magnetic force in order to rotate the table device 8.
1 is a rotating plate, and 15 is a rotating magnet. FIG. 3 shows the structure and frequency detection section of the stand device 8. Further, FIG. 4 shows the configuration of the stand device 8 in detail. 8a
Reference numeral 17 denotes a table for placing the food, and 17 is a support member that is attached to the table 8a and transmits its weight to the balance rod 16. 13 is food 7 to eliminate uneven heating of food.
It is a wheel that can be heated while rotating.
Reference numeral 19 denotes a connecting ring for connecting the shafts of the wheels 13 and for arranging the wheels in a circular manner. Reference numeral 18 denotes a ring-shaped support rotary table that rests on wheels and rotates. spring 12
is attached to the center of the mounting table 8a, and is connected to the spring 12, the support rod 17, and the support rotating table 18 by a balance rod 16. The support member 17 transmits the weight of the food product downward to the balance rod 16, and the balance rod supports the force and supports the rotary table 18 and the spring 1.
Tell 2. This causes the spring 12 to vibrate. The frequency of this spring 12 changes depending on the weight of the food. 10 is a magnet, which vibrates in the same way as the vibration of this spring 12. Additionally, this magnet is covered with a material that blocks high frequencies and allows magnetic fields to pass through. 11
is a magnetic field strength detection unit that detects the strength of the magnetic field from the magnet 10, and when the magnet 10 vibrates, the distance between the magnetic field strength detection unit 11 and the magnet 10 changes, so that the frequency can be detected. . This magnetic field strength detection element includes a Hall element and the like. Numerals 14 and 15 are magnets, and by rotating the rotary plate 9 outside the heating chamber, this force is transmitted to the support rotary table 18 using the attraction or repulsion force of the magnets 14 and 15. 1 unit
The mounting table 8a and the balance rod 16 placed on 8 also rotate in the same way. Reference numeral 20 denotes a mounting member for preventing the balance rod 16 from detaching from the mounting table 8a. FIG. 5 shows the relationship between the magnet 10 and the magnetic field strength detection section 11, and FIG. As shown in FIG. 1B, the voltage generated between AB in the Hall element changes depending on the current I flowing through the Hall element and the magnetic field H applied thereto. Therefore, by passing a constant current through the Hall element, changes in magnetic field strength can be detected by the voltage generated between AB. Furthermore, by making the bottom plate of the heating chamber 5 of a material that blocks high frequency waves but allows the magnetic field to pass through, the magnetic field strength detection section 11 can detect changes in the strength of the magnetic field without being affected by the high frequency waves. Figure 6a shows the vibration when a weight is attached to a spring.The elastic constant of the spring is k, and the mass of the weight is m.
In this case, the frequency f is

[Formula] The larger the mass, the smaller the frequency of vibration. FIG. 3b shows a mounting device according to an embodiment of the present invention. This structure and operation will be explained. First, the weight of the food 7 is applied to the mounting table 8a, and its force is applied to the point B of the balance rod 16 by the support member 17. Balance rod 1
6 is point _A1 , which plays the role of a lever and whose fulcrum rests on the support rotating table 18. Therefore, the force applied to _one point C is
The force applied to _one point B is multiplied by the length between A ₁ B ₁ / the length between A ₁ C ₁ , so no large force is applied. On the other hand, the amplitudes of _one point B and _one point C are opposite.
C ₁ point is large and B ₁ point is small. Therefore, even if the amplitude at _one point B, that is, the mounting table 8a is small, the amplitude at _one point C, that is, the magnet 10 is large. This means that the vertical fluctuation of the mounting table 8a due to the weight of the food is small, but the fluctuation of the magnet 10 is large, and the change in magnetic field strength is also large. Also, the frequency changes depending on the weight. FIG. 7 shows the relationship between the various parts when the magnet 10 is vibrating. Figure a shows the magnet 10 and the magnetic field strength detector 1.
1, and the distance L changes over time due to vibration. Figure b shows the distance L and the magnetic field strength detector 1.
1 shows the relationship between magnetic field strength. In the same figure, c is a and b.
3 shows temporal changes in magnetic field strength due to vibration of the magnet 10 of the magnetic field strength detection unit 11. Figure d shows the relationship between the magnetic field strength of the Hall element and the output voltage when a constant current is passed when a Hall element is used as the magnetic field strength detection section 11. Figure e shows the output voltage of the Hall element from c and d. Therefore, the same frequency as the vibration of the magnet 10 can be detected by the Hall element. FIG. 8 shows a circuit for extracting the output of this Hall element as a signal. The _two points A are the output voltages from the Hall elements. At point _B , only the alternating current component is transmitted by the capacitor. The voltage at _two points B is amplified to form the waveform at _two points C. By inputting the voltage at _two points C to the comparator, it is possible to extract square wave output like _{the two} points D. Figure 9 shows the vibration of the spring 12, that is, the magnet 10.
D This shows the relationship between the output waveforms at _two points, and shows that the vibration frequency varies depending on the weight of the food. That is, between a and b in the same figure, the frequency of vibration in the figure a is higher, so the weight of the food is smaller. FIG. 10 is an example of a control circuit for the high frequency heating device of the present invention. A microcomputer 24 constitutes a control section and performs storage, judgment, calculation, data input/output, etc. 25 is an oscillation circuit that generates a fundamental frequency for measuring the vibration frequency of the magnet 10. 6 is a magnetron that generates high frequency waves, and 23 is a fan motor for cooling the magnetron 6. 21 and 22 are relays and their drive circuits for controlling the output of the magnetron 6. FIG. 11 shows the operation of weight measurement. Figure a shows the pulse extracted from the vibration of the magnet 10, Figure b shows the output waveform of the oscillation circuit 25, and Figure c shows the flow of the measurement method at that time. That is, magnet 1 in figure a
The frequency of the magnet 10 can be determined by counting the number of pulses from the oscillation circuit between the falling point P of the pulse from the zero vibration and the next falling point Q. Next, a block diagram of the internal functions of the microcomputer 24 in the circuit diagram of FIG. 10, which are actually used in the present invention, will be explained.
24a inside the microcomputer 24 constituting the control section is an oscillation circuit 25 as a time base.
A pulse counter that counts the pulses of 24
b is a vibration detection means 24 that detects vibrations of the magnet 10;
24d is a weight storage means that stores the correlation between the vibration frequency and the weight of the object to be heated; and 24d is a heating form storage means that stores the combination of weight, heating output, and time distribution. FIG. 11 shows the actual operation, in which the vibration of the magnet 10 is detected by the vibration detection means 24b.
The pulse counter 24a counts the number of pulses from the oscillation circuit 25 as a time base that enters from the falling point P of the pulse to the next falling point Q. This is actually magnet 1
This measures the period of 0 vibration, which is equivalent to the actual frequency. Then, the weight of the food is determined by the weight storage means 24c based on the vibration frequency detected by the vibration detection means 24b and the pulse counter 24a. Next, the heating output and time allocation are determined by the heating form storage means 24d based on the calculated weight. The configuration is such that a signal is output to and controlled by a drive circuit for relays 21 and 22 for controlling the output of the magnetron 6. As described above, food can be measured inside the heating chamber, and the signal can be easily transmitted outside the heating chamber using magnetism, so it is not affected by high frequencies. Furthermore, the measurement accuracy is completely unaffected by variations and errors caused by components on the control circuit. A microcomputer then calculates the heating output, time, pattern, etc. corresponding to the measured weight. An example of the operation of a microwave oven as an embodiment of the present invention will be described with reference to FIG. FIG. 12 shows an example of the display section 1 and the setting section 2. The setting section 2 has a cooking menu selection key, and the heating time, output, and pattern are determined based on the selected menu and the measured weight of the food. The operation will be explained using an example of thawing frozen food. When you press the "Decompress" key 26 in the setting section 2, the first
Display Og as shown by A in Figure 2b. Next, by placing the frozen food on the mounting table 8a in the heating chamber, the magnet 10 vibrates, and the microcomputer 24 calculates the weight by determining the frequency or period of vibration. Display the weight as shown. For this purpose, the correlation between vibration frequency and weight is stored in the storage section of the microcomputer 24. Then, after the weight is displayed, the "cooking start" key 27 is pressed to start heating. Immediately after the start, the microcomputer 24 calculates the heating time T corresponding to the weight of the food, and the display section 1 switches to display the time as shown in C of FIG. 12B. Thereafter, the remaining time is displayed as shown in FIG. 12b. Furthermore, the heating output P, heating time T, and heating pattern for defrosting the food at this time are shown in FIGS. After that, thawing automatically progresses, and when a predetermined period of time has elapsed, high frequency oscillation is stopped and thawing is completed. In addition, Fig. 13 a shows heating for T ₁ second with an output of 600W, stopping for the next T ₂ seconds, and heating for the next T ₃ seconds.
Indicates heating at 200W. Furthermore, Figure 13b
indicates that each time is determined from the weight of the food, Wg. In this way, just by placing the object to be heated in the heating chamber,
Since the weight is measured and the food is cooked automatically, it is easy to use and allows for efficient cooking. Effects of the Invention As described above, according to the present invention, the following effects can be obtained. (1) It is easy to use because the weight of food can be measured by placing it inside the heating chamber. (2) Since the weight of food is measured by the frequency of the spring, the causes of measurement errors are the elastic modulus of the spring, the accuracy of the balance rod, and the basic oscillation circuit, which are affected by the strength of the magnetic field and variations in the detection circuit. Not done. (3) It is not affected by high frequencies because the vibration is transmitted by a magnetic field. This allows measurements within the food heating chamber. (4) Since the weight signal is converted into a vibration frequency by the spring, no circuit-based A-D conversion function is required. (5) To eliminate uneven heating of food, a method of heating while rotating can be easily implemented. (6) The structure is such that there is little variation in the height of the mounting table due to the weight of the food, and the amplitude of the magnet can be increased.

[Brief explanation of drawings]

Fig. 1 is an external perspective view of a microwave oven that is an embodiment of the present invention, Fig. 2 is a side sectional view of the microwave oven, Fig. 3 is a sectional view showing the frequency detection section of the stand of the microwave oven, and Fig. 4 The figure is an exploded perspective view of the stand of the same microwave, No. 5
Figures a and b are principle explanatory diagrams showing the vibration detection principle of the frequency detection section of the same range, Figures 6 a and b are principle explanatory diagrams showing the principle of vibration of the spring in the same range, and Figures 7 a,
b, c, d, and e are characteristic diagrams showing the relationship between each part of the weight measurement system in the same part, Figure 8 is a waveform shaping circuit diagram of the output voltage from the Hall element in the same part, and Figure 9 a and b are the same. Figure 10 is a circuit diagram of the same range, Figures 11a, b, and c are characteristic diagrams and flowcharts for reading the frequency of the same part and converting it to weight. Figures 12a and 12b are front views and display state diagrams of the setting section of the microwave oven, and Figures 13a and b are characteristic diagrams showing conversion for determining heating conditions for defrosting in the microwave oven. 5... Heating chamber, 6... Magnetron, 7... Food (object to be heated), 8... Placing device, 8a... Placing table, 9... Rotating plate, 10... Magnet, 11... Magnetic field strength detection Part (Hall element), 12... Spring, 13
... Axle, 16 ... Flat scale rod, 17 ... Supporting material, 1
8...Support rotary table, 19...Connection ring, 20...Mounting material, 24...Microcomputer, 25...
Oscillation circuit.

Claims (1)

[Claims] 1 Consisting of a heating chamber for storing an object to be heated, a heating means for heating the object to be heated in the heating chamber, and a spring on which the object to be heated is placed and whose vibration frequency changes depending on the weight of the object to be heated. a placing table device, a weight storage means for storing the correlation between the frequency of the said placing table device and the weight of the object to be heated, a heating form storing means for storing the combination form of the weight, heating output and time distribution, and the placing table device; An oscillation circuit that serves as a time base for detecting the vibration frequency, and a magnet that uses the oscillation circuit as a time base and is provided in the vibrating section of the stand device, and detects changes in magnetism due to the vibrations of the magnet. vibration detecting means for detecting the frequency of vibration, the weight storage means determines the weight from the frequency detected by the vibration detection means, the heating form storage means determines the heating form from the determined weight, and the heating form is determined by the heating form storage means. and a control means for controlling the heating means based on the heating means, and the structure of the device for placing the object to be heated includes a connecting wheel for connecting three or more wheels and the shafts of the wheels, and a connecting wheel for arranging the wheels in a circular shape. , a support rotary table that is mounted on the wheels and is rotatable, a mounting table on which the object to be heated is placed, a balance rod, and a device on the balance rod that uses the support rotary table as a fulcrum and the load of the mounting table as a point of force and balances this point of force. A heating cooker with a structure in which one point of effort is supported by a spring.