JPS6162725A - Heating and cooking apparatus with weight sensing function - Google Patents

Abstract

PURPOSE:To provide an accurate sensing of a weight of food and enable a stable heating and cooling with a simple constitution by a method wherein a sensing operation of a weight sensing means is performed in cooperation with an opening and closing of a door and a weight reference point adjusting and setting means is set in response to a mean sensed value. CONSTITUTION:A weight sensing means for sensing a weight of food 6 in cooperation with a closing operation of a door 2 and a weight reference point adjusting and setting means for correcting an error in the reference weight are provided and the sensed weight is corrected in response to the desired value of the weight reference point adjusting and setting means. That is, the reference point corresponds to the condition in which a receiving tray 7 is mounted on a mount table 8 and the weight W of the food corresponds to the value in which a zero (g) is applied. Only the tray 7 is placed on the mount table and its vibration is generated by a closing operation of the door 2. The weight is vibrated under the number of vibration corresponding to the weight and a period at that time T1 is measured. This period T1 shows a more superior power of resolution in measuring a period of a plurality of pulses (n pulses) than a period of one cycle. A measured weight is calculated in response to an approximate equation of W=C1T<2>+C2T+C3 stored in the microcomputer 33 with the measured period T1.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a heat cooker with a weight detection function that improves cooking performance by measuring the weight of food and cooking it with heat according to the weight. be.

Conventional Structure and Problems There is a high-frequency heating device disclosed in Japanese Patent Application Laid-open No. 160742/1983 as an example of a conventional heat cooker with a weight detection function. This high-frequency heating device supports the food table with springs.
The idea is to measure the weight of food by making it vibrate using the elasticity of the spring and detecting the frequency of vibration. It is true that heating can be done according to the amount of food, so there is no need for the user to set the heating time or heating output, and there is an advantage that cooking performance is improved.

However, in reality, when a large number of springs are produced, variations occur in the elastic constant of the spring, which causes errors. Furthermore, if the weight of the mounting table itself is also produced in the same manner, there will be variations, making it impossible to accurately measure the weight of the food. If the weight of food cannot be accurately measured, heating control will be disrupted, resulting in insufficient cooking.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to accurately detect the weight of food with a simple configuration and enable stable heating and cooking.

In order to achieve the configuration and purpose of the invention, the heat cooker with a weight detection function of the present invention has a door provided at the front of the heating chamber that can be opened and closed for taking food in and out, and which is linked to the closing operation of this door. A weight detection means for detecting the weight of the food, and a weight reference point adjustment and setting means for correcting errors in the reference weight are provided, and the detected weight is corrected by the set value of the weight reference point adjustment and setting means. And in conjunction with the door opening/closing operation,
Moreover, since the weight detection means detects the reference weight a plurality of times and sets the weight reference point adjustment setting means based on the average value, accurate setting is possible. Furthermore, since the weight detected by the weight detection means is corrected, the corrected detected weight also becomes an accurate value.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an external perspective view of a microwave oven which is a high frequency heating device as an embodiment of the present invention. 1 is a heating chamber;
A door 2 that can be opened and closed is provided on the front side, and 5 is a main body that covers the main body. A display section 3 for displaying heating temperature, heating time, weight of food, etc. is provided on the front surface. This display section 3 further displays the detected weight of the weight detecting means or a value corresponding to the detected weight during setting of the reference weight, the set value of the weight reference point adjustment setting means, and the like. Reference numeral 4 provides an operation input section for setting heating time, heating output, cooking menu, and instructing start and stop of cooking.

FIG. 2 shows a side sectional view showing the structure of this microwave oven. In the figure, a heating chamber 1 for storing food 6 is provided, and a door 2 which can be opened and closed for taking food in and out is provided in front of the heating chamber 1. The receiver for receiving the food 6 has a structure in which a plate 7 is provided and the plate 7 is placed on a mounting table 8. The mounting table 8 is supported by a mounting table shaft 10 passing through a hole in the bottom plate of the heating chamber, and is held by being inserted into the shaft 11. The shaft 11 is fixed in a rotatable state by a vibration-side spring spacer 16 and a shaft fixing member 19. Therefore, the loads of the food 6, the tray 7, the mounting table 8, etc. are applied to the vibration-side spring spacer 16. Vibration side harness spacer part 1
6 is supported by a plate spring 12 and is a fixed side spring spacer 17
is connected to. This plate spring 12 is attached in parallel via a vibration side spring spacer 16 and a fixed side spring spacer 17, and is pressed and fixed by a fixed side spring body 18, a bearing 2o, and a shaft fixing member 19. A motor 1 for rotationally driving the mounting table 8 is mounted on the vibration side spring spacer of the vibration section.
5, motor side gear 14 and shaft side gear 1
The rotational driving force is transmitted to the support 11 via 3. The fixed side spring spacer 17 and the fixed side paneosae 18 on the fixed side are fixed to the spring mounting base 9.

With the above configuration, the weight of the vibrating parts such as the food 6 and the mounting table 8 is applied to the leaf spring 12. This frequency is applied to the leaf spring 12. It is determined by the load and the elastic constant of the leaf spring 12, and if the same leaf spring 12 is used, the frequency corresponds to the load. If the load is large, the frequency will be small; if the load is small, the frequency will be large. In order to detect this frequency, a magnet 21 and a detection coil (v22) are provided. A magnet 21 is attached to the vibrating part, and the detection coil 22 is fixed in a vibration-free place. In this configuration, the magnet 21 vibrates together with the vibrating section, and as a result, the magnetic field strength in the non-vibrating sensing coil 22 changes, thereby generating an electromotive force in the sensing coil v22. The frequency of the electromotive force generated in the detection coil 22 is the vibration itself of the magnet 21, that is, the vibration section. Therefore, by detecting the frequency of the electromotive force generated by the detection coil 22, the load applied to the leaf spring 12 can be detected. Therefore, it is necessary to generate vibrations in this vibrating section.

Therefore, an excitation arm 23 is provided to apply vibration to the vibrating section. Further, this excitation arm 23 is configured to move and operate when the door 2 is opened and closed. Add this configuration to the third
As shown in the figure.

FIG. 3 is a perspective view of a vibrating section constituted by the leaf spring 12 and an excitation mechanism section for causing the vibrating section to generate vibrations. First, the door 2 is in a state that it can be opened and closed freely, and a door arm 25 is connected to the door 2. The door arm 25 transmits the opening/closing operation of the door 2 to the excitation cam 26. This excitation cam 26 rotates by a predetermined angle. The excitation cam 26 is provided with a small diameter part and a large diameter part, and the excitation lever 27 is in contact with either the small diameter part or the large diameter part. Move the large diameter section. An enlarged view of the excitation cam 26 is shown in (b). A- shows the contact trajectory of the excitation lever 27 on the small diameter part of the excitation cam 26 and the large diameter part.
The order of D is indicated by a dotted line. When the door 2 is closed, the excitation lever ~27 is at point A, and as the door 2 is opened, it is at point B.
point, move from the narrow diameter part to the large diameter part at point B, and then reach point C as the door 2 is opened. That is, the excitation lever 27 moves from the small diameter portion to the large diameter portion by opening the door 2. Conversely, for the action of closing door 2, the movement goes from point C to point D. Since the trajectory at this time is pulled by the coil spring 39, it passes through point D and reaches point E. Then, at point E, the cam pushes it toward the narrow diameter portion and returns to point A. By closing the door 2, the excitation lever 2
7 moves from the large diameter part to the small diameter part. The movement is rapid from point E to point A. With the above F14 configuration, the angle of the excitation lever 27 changes by the difference between the small diameter part and the large diameter part in conjunction with the door opening/closing operation. This change is then transmitted to the excitation arm 2a by the excitation rod 28. The excitation arm 23 is configured to apply force to the vibrating section to generate vibration.

FIG. 4 shows a detection circuit for detecting the frequency of the vibrating section and a zero g adjustment circuit as a weight reference point adjustment and setting means for correcting the detected weight. First, as the magnet 21 attached to the vibrating section vibrates, an electromotive force having the same frequency as the vibration frequency of the magnet 21 is generated in the sensing coil/L'22. Since this electromotive force is small, it is amplified by an amplifier circuit 29, and a filter circuit 30 is provided to remove noise other than the vibration of the magnet 21. And this filter circuit 3
A waveform shaping circuit a1 is provided to shape the signal that has passed through 0 into a waveform that can be easily processed digitally by a microcomputer, that is, a square wave.

Then, it is input to the input terminal I of the microcomputer a3. On the other hand, a zero J adjustment polyurethane 32 is provided as a circuit for correcting the detected weight.

The microcomputer 33 is configured to correct the detected weight detected by the detection circuit with a value taken in by the zero I adjustment volume 32.

The data conversion method for inputting the zero I adjustment polyurethane 320 to the microcomputer 33 is structured such that a zero g adjustment oscillator 38 is provided to convert the resistance change of the zero g adjustment volume 32 into a frequency. Therefore, the oscillation frequency corresponding to the resistance value of the zero g adjustment volume 32 is set by the microcomputer 33.
Enter.

The microcomputer 33 has a counter input terminal CT.
The detected weight is corrected based on this oscillation frequency.

FIG. 5 is a weight detection characteristic diagram showing the correction function of the detected weight by the zero g adjustment volume 32.

The horizontal axis shows the period T, which is the reciprocal of the vibration frequency, and the vertical axis shows the weight W of the food 6. One of the causes of measurement error in the detected weight W of the food is the variation due to the elastic constant of the leaf spring 12, and the other is the variation in the initial weight, that is, the weight of the support is due to the weight of the pivoting and the loading. 06 There are variations in the parts that make up the vibrating part, such as weight. It is necessary to correct these. For example, B in the figure is based on a design with no variation, and there is no need to correct it at all. Therefore, the relational expression between the period T and the weight W of the food is stored in the microcomputer. The relational expression CW=CI T2+C2T+C3 becomes a quadratic expression, and is the characteristic of B in the figure. For example, if the food has the characteristic shown in the figure, it will show a negative value when the weight flW of the food is 0 g. Therefore, it is necessary to correct the minus amount of a-a'. Conversely, if the food has characteristics C, the weight of the food is f.
When f1W is zero l, it shows a positive value. i.e. b-b
'It is necessary to correct the minute value.

FIG. 6 shows a reference point setting method using a zero g adjustment volume 32 as a weight reference point adjustment and setting means. The reference point is the mounting table 8
It is assumed that the plate 7 is placed on the tray and the weight iW of the food is 0 g. The operation at this time will be explained according to the diagram. First, only the plate 7 is placed on the mounting table, and vibration is generated by the closing operation of the door 2.

It vibrates at a frequency corresponding to the weight at this time, and the period T1 at that time is measured. The resolution of this period T1 is better when measuring the period of a plurality of pulses (n pulses) than the period of one cycle. Based on the measured period T1, the approximate formula W=CIT2+C2 stored in the microcomputer 33
Calculate the measured weight by T+Sa3. Therefore, rather than correcting the reference point only once, it is better to measure it several times and then use the average to determine the correction value for the reference point. Therefore, in the case of FIG. 6, the method is to measure three times and take the average.

Therefore, after the first weight W1 is loaded, the number display is changed. In other words, the display contents indicating that this is the second time will be explained in detail later with reference to FIG. Perform the above operation three times. That is, W2 and W3 are taken in. Then, the average W of the three measured weights W1, W2, and W3 is determined. Therefore, it is necessary to make the set numerical value of the zero g adjustment polyurethane 32 and the average value W correspond to each other in order to correct this. The zero I adjustment volume 32 is divided into 100 levels from 0 to 99.
This means that the rubel center value is set at level 50. In other words, since the 50 level is the center, Ld='+50 is the setting level of the zero g adjustment polyum 32. The resistance value of the zero y adjustment volume 32 is converted into a frequency by the zero I adjustment oscillator 38, and is assigned from 0 to 99 depending on the frequency.

Therefore, the resistance value of the zero J adjustment volume 32 is set so that it becomes the same value as the displayed Ld. This completes the weight reference point adjustment setting.

FIG. 7 explains the operation when measuring the weight W of actual food. First, the receiver places food 6 on plate 7 1 and closes door 2 to generate vibrations. Then, the period T of multiple pulses of 7 minutes (n pulses) of the vibration at that time is measured. Approximate formula W stored in the microcomputer 33 from the measured period T
= C I T 2+ C2T+c3 to calculate W'. It is necessary to correct this W'. Therefore, the set level is determined from the oscillation frequency determined by the resistance value of the zero I adjustment volume 32. Since there is a rubel and the center is assigned to level 50, the correction value is 3x(50-Ld). Therefore, the correct measured value W of the food 6 is W=W'+3(50-Ld). The measurement of food 6 is thus completed.

FIG. 8 is an enlarged perspective view of the display section 3 and operation input section 4 of a microwave oven as a heat cooker with a weight detection function according to the present invention. Also shown are the circuit boards 1 to 4o to which electronic circuits such as a zero I adjustment polyurethane 32 and a microcomputer 33 are attached and wired.

When the printed circuit board 4o is installed after the operation input section, the position of the zero lA adjustment hole 34 and the zero g adjustment volume 32 are adjusted.
Install them so that their positions match.

Then, the zero Y adjustment volume 32 can be set by penetrating the zero I adjustment hole 34 with a screwdriver or the like. Further, the zero I adjustment hole 34 is not located at the front like the operation input section 4, but is located at an inconspicuous location on the side.

This is because once the settings are made, they are rarely reset.

Fig. 9 shows the display contents when setting the weight reference point.

The operation at the time of setting has already been explained based on FIG. 6 above. FIG. 9(,) shows a state in which the microwave oven is normally stopped and the time is displayed. In order to switch from this state to the weight reference point setting mode, use the keys on the operation input section 4. This is done by not providing a special key for entering the weight reference point setting mode, but by inputting a plurality of predetermined keys in a predetermined order among the keys shown in FIG. 8. In other words, a setting method such as encryption may be provided. When the above-described weight reference point setting mode is input, a display as shown in FIG. 6(b) appears. That is "183"
will be displayed. The 1 on the left side indicates the first measurement. Father's two digits 83 indicate the setting level of the zero I adjustment volume 32. Then, the door 2 is closed and the first measurement is performed. When the measurement is completed, the display shown in FIG. 3(c) appears. That is, the left end changes from 1 to 2, indicating that the next measurement will be performed twice. Measurements are made in the same manner a second time and a third time. When the third measurement is completed, it becomes "52s3J" as shown in the same figure (e). The two digits on the left "52" are the 6th
The level of Ld explained in the figure is displayed.

In other words, since the center value is 52 levels compared to 50 levels, a two-level difference occurred. This needs to be corrected. Therefore, the level of the zero J adjustment polyum a2 is set to match Ld. In other words, the left two digits "
Set the two digits on the right to be "52" to match 52J. This completes the setting of the zero g adjustment volume 32. In this display, the left two digits and the right two digits can be set to the same value, making them easy to read and less likely to be misread.

FIG. 10 shows a control circuit diagram of a microwave oven which is an embodiment of the present invention. The microcomputer 33 plays a central role in control, and has memory, arithmetic, judgment, and input/output control functions, and performs the control shown in FIG. It has a function of generating signal output to control the output of 24, etc. 36 in the same figure is an output control relay, and the microcomputer 33
The output of the magnetron 24 is controlled based on the signal from the magnetron 24. Reference numeral 37 denotes an operation control relay, which controls the operation of the microwave oven, such as cooking, stopping, and termination, based on signals from the microcomputer. Reference numeral 38 is a reference oscillation circuit for operating the microcomputer 33, and is also used for counting reference time.

As described above, according to this embodiment, there is a door provided at the front of the heating chamber, a weight detection means for detecting the weight of food in conjunction with the opening/closing operation of the door 2, and a device for correcting errors in the reference weight. By providing a weight reference point adjustment and setting means and correcting the detected weight according to the setting value of the weight reference point adjustment and setting means, it is possible to accurately measure the weight of the food. Since the reference weight is detected a plurality of times by the weight detection means and the weight reference point adjustment setting means is set based on the average value, accurate setting is possible, and therefore the weight of the food is also accurately measured. It has the effect of being able to.

Effects of the Invention According to the present invention, the following effects can be obtained.

(1) Since the detection by the weight detection means is linked to the opening/closing operation of the door, there is no need for complicated operations, and the operation is simple because the operation is just opening/closing the door.

(2) Since the detection means of the weight detection means is detected multiple times and the weight reference point adjustment setting means is set based on the average value, accurate settings can be made and the detected weight of the food is also accurate. .

(3) Since the number of detections of the weight detection section is displayed, the number of detections can be confirmed at a glance, and there is no need to make mistakes in operation.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of a microwave oven as an embodiment of the present invention, and FIG. 2 is a side sectional view showing the structure of the microwave oven.
Figure 3 is a perspective view of the vibrating section and exciter groove of the weight detection section that detects weight, and Figure 4 is a detection circuit diagram that detects the frequency of the vibrating section and zero I adjustment for correcting the detected weight. A circuit diagram, Fig. 5 is a weight detection characteristic diagram showing the correction function of the detected weight by the zero g adjustment polyurethane, Fig. 6 is a flowchart showing a reference point setting method using the zero g adjustment volume as a weight reference point adjustment setting means, and Fig. 7 The figure is a flowchart showing the operation when measuring the weight of actual food, Figure 8 is an enlarged perspective view of the display section and operation input section, Figure 9 is a diagram showing the display contents when setting the weight reference point, and Figure 10 is a diagram showing the display contents when setting the weight reference point. The figure is a control circuit diagram of a microwave oven as one embodiment of the present invention. 1... Heating chamber, 2... Door, 3...
...Display tube, 4...Operation input section, 5...
・Main body, 6... Food, 7...
The receiver is a plate, 8... Placement stand, 9... Spring mounting stand, 10... Placement stand shaft, 11... Shaft, 12... ...Plate spring, 13...Shaft side gear, 14...Motor side gear, 15...
・Motor, 16... Vibration side spring Nuvasa, 17
・・・・・・B fixed (II vanunubesa, 1 day...
...Fixed side honeycomb 19...Shaft fixing material, 20
... Bearing, 21 ... Magnet, 22 ...
...Detection coil, 23...Excitation arm, 24
...Magnetron, 25 ...Door 7-
4.26...Excitation cam, 27...Excitation lever, 2B...Excitation rod, 29...
...Amplification circuit, 30...Filter circuit, 31.
・・・・・・Heat shape shaping circuit, 32・・・Zero J adjustment volume, 33・・・・・・Microcomputer, 34
...... Hole for zero g adjustment, 35... Reference oscillation circuit, 36... Output control relay, 37...
...Operation control 1) L/-138...Zero I
Adjustment oscillator, 39... Coil spring, 40...
...Printed circuit board, 41...Fan motor. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (3)

[Claims] (1) A heating chamber for storing food, a heating source for heating the food, an output control means for controlling the heating output of the heating source, and a heating chamber located in the front of the heating chamber for controlling the loading and unloading of the food. a door that can be opened and closed freely, a weight detection means that detects the weight of the food in conjunction with the opening and closing operation of the door, and a weight reference point adjustment setting means that adjusts a weight reference point; The adjustment setting is performed based on the weight detected by the weight detecting means at the reference weight. (2) The weight detection function according to claim 1, wherein the adjustment setting of the weight reference point adjustment setting means is performed based on the average value of the weight detected by the weight detection means a plurality of times at the reference weight. Heating cooker. (3) The overheating cooker with a weight detection function according to claim 2, further comprising a display unit that displays the number of times the weight detection unit detects the number of times the weight detection unit detects the number of times the weight detection unit detects the number of detections.