JPH0368301B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a heating device equipped with a weight sensor, and more particularly to one that detects the weight of an object to be heated on a placing tray in a heating chamber.

Configuration of conventional example and its problems A heating device equipped with a weight sensor has already been put into practical use. For example, in a microwave oven, the time for defrosting is calculated using a weight sensor, and such a weight sensor is mounted below a placing tray in a heating chamber, which has been commercialized. With this configuration, the weight of the object to be heated can be detected simply by placing it in the heating chamber, so users can use this weight sensor without the operational complexity associated with using a scale. can.

On the other hand, in the case of a device that detects the weight of an object to be heated in a heating chamber, the problem is how to subtract the weight of a mounting plate attached to the heating device, which is a tare processing operation. In microwave ovens, such placement plates are often made of ceramic or heat-resistant glass, and are inevitably quite heavy, weighing around 1,000 grams. Moreover, there is a large variation in the weight of ceramic plates, which can vary by ±50 grams, or about 100 grams. However, the weight of the heated object is 50~
It is about 1000 grams, and the total weight of the mounting plate and its variation cannot be ignored. In other words, the method of mechanically subtracting the standard weight of the mounting plate from the measured weight will result in too large an error.

In order to subtract the weight of such a placing plate, conventional heating devices equipped with a weight sensor empty the top of the placing plate each time cooking is completed, and measure only the weight of the placing plate. A method of storing and processing it as a tare bag will be put into practical use. However, with this method, if the user makes a mistake, for example, closes the door without taking the heated items out of the refrigerator after cooking is finished, or takes out the heated items together with the mounting plate, it will naturally occur that the The weight of the plate cannot be measured correctly and taring fails.

Purpose of the Invention The present invention solves the above-mentioned conventional problems, and makes it possible to accurately subtract the weight of the mounting tray from the total measured weight without the need for taring, and also to suppress the error of the weight sensor to a small level. The purpose is to provide a heating device.

Structure of the Invention In order to achieve the above object, the heating device of the present invention includes a weight sensor that detects the weight of an object to be heated, a mounting plate on which the object to be heated is placed, and a device that records the weight of the mounting plate. The true value of the weight of the mounting plate and the detected value by the weight sensor are recorded in the storage means, and when the weight of the object to be heated is detected by the weight sensor, the weight of the mounting plate is recorded. It is configured to automatically subtract and estimate the detection error, so that the weight of the mounting plate can be subtracted without the troublesome operation of taring, and the detection error can be reduced.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a perspective view of a 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 heating mode key 4 is arranged on the operation panel 3. The heating mode keys 4 include a defrost key using a weight sensor and the like. Further, a tray weight setting switch 5 is arranged below the operation panel 3.
Used to record the weight of the mounting plate.

FIG. 2 shows the construction of such a heating device. Commands input from the heating mode key 4 on the operation panel 3 are decoded by the control unit 6. Now, if a heating mode key using a weight sensor such as a defrost key is pressed, the control unit 6 calculates the weight of the object to be heated 9 placed on the mounting tray 8 in the heating chamber 7 using the weight sensor 1.
Detect using 0. The weight detected at this time is the total weight of the object to be heated 9 and the mounting plate 8.
The control unit 6 reads the weight of the mounting plate from the memory 11 and subtracts it to calculate only the weight of the object to be heated. With this configuration, only the weight of the object to be heated can be detected without a tare operation. Note that the procedure for storing the weight of the mounting plate 8 in the memory 11 will be described in detail later.

The weight sensor 10 may be one that detects changes in capacitance or one that detects displacement using a strain gauge.
Vibration detection methods that measure the natural frequency that changes depending on the heated object can be applied. Data from the weight sensor 10 is input to the control unit 6 via the detection circuit 12. Further, the mounting plate 8 is rotationally driven by a motor 13, and uneven baking during microwave heating is improved.

Memory 11 was backed up by battery.
A memory such as RAM or nonvolatile memory that can retain stored contents even without power supply is used, and the weight of the mounting tray 8 is input at the time of shipment from the factory. As the memory, MN1218 manufactured by Matsushita Corporation can be used.

The memory 11 stores the true value of the weight of the mounting plate and the value detected using the weight sensor 10. This detected value is used in the same bag retrieval process described above. Furthermore, the accuracy of this weight sensor can be determined from the difference from the true value, and the measured value of the object to be heated 9 can also be corrected. For example, suppose the weight of a certain mounting plate is 1000 grams (true value).
Suppose that a weight sensor detects this as 1020 grams. The error is +20 grams per 1000 grams. In other words, the error of this weight sensor is +2 grams per 100 grams. Therefore, if the detected total weight is 1270 grams, the control section first subtracts the weight of the placement tray, 1020 grams, from this. Then, 250 grams is the weight of the object to be heated. If we take into account the error of this weight sensor, the true value of the object to be heated is 245 grams. Therefore, this error may be stored in the memory instead of the true value of the weight of the mounting plate.

Now, when the weight of the object to be heated 9 is detected and the heating time is calculated, the control section 6 starts supplying power to the heating means 15 via the driver 14. In the illustrated example, the heating means is a magnetron, which is cooled by a fan 16.

Next, the procedure for inputting the weight of the mounting plate into the memory will be explained using FIG. 3. Normally, zero is displayed on the display section as shown in Figure a. If the plate weight setting switch 5 is pressed here, the mode shifts to the adjustment mode, and the detected weight is displayed on the display section as shown in figure b. Therefore, if only the mounting plate is placed in the heating chamber, its weight will be displayed as, for example, "1020" grams.

When the setting switch 5 is then pressed again, this detected weight is stored in the memory and the display returns to zero as shown in Figure c. Here, use some method, for example, a timer knob, to input the true value of the weight of the mounting plate as "1000 grams". This is diagram d.
Here, the error per 100 grams mentioned above is “+2”
You can also enter grams. Finally, if the setting switch 5 is pressed once again, this is input, the display returns to a, and the adjustment mode ends. The setting switch 5 may be recessed inside the machine so that it cannot be operated from the outside, or may be configured to shift to the adjustment mode when specific keys are operated in a specific order.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) The weight of the mounting plate can be automatically subtracted from the measured weight without the troublesome operation of taring.

(2) By storing the weight of the mounting plate, which varies widely, in memory at the time of shipment from the factory, the weight of the mounting plate can be handled accurately.

(3) The error of the weight sensor can be stored in memory, and the weight of the object to be heated can be handled accurately.

(4) A memory that can retain its stored contents even without power supply can store the weight of the tray.
It can also be used to input the user's favorite heating pattern for the home menu, etc., and this data will not be destroyed even in the event of a power outage.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the main body of a high-frequency heating device showing an embodiment of the present invention, Fig. 2 is a block diagram showing the same configuration, and Fig. 3 is a diagram showing a procedure for memorizing the weight of the same mounting plate. . 6...Control unit, 7...Heating chamber, 8...Place plate,
9... Heated object, 10... Weight sensor, 11...
Memory, 15...Heating means.

Claims (1)

[Claims] 1. An object to be heated, a mounting plate attached to a heating device on which it is placed, a heating chamber that houses these, a heating means provided in this heating chamber, and a control unit that controls power supply to this heating means. a weight sensor for detecting the weight of the object to be heated and the placing plate; and a non-volatile storage means for recording the weight of the placing plate; The value detected using the weight sensor and the true value of the weight of the placement plate or the difference between the detected value and the true value are recorded at the time of factory shipment, and the control unit is controlled by the operator of the device. When an object to be heated is placed on a placing plate and stored in the heating chamber, the weight of the placing plate recorded in the storage means is subtracted from the weight measured using the weight sensor. In addition to calculating the weight, an error is corrected from the weight of the object to be heated, which is calculated based on the true value of the weight of the placing plate recorded in the storage means or the difference between the true value and the detected value, and the corrected value is calculated based on the weight of the heated object. A heating device configured to control power supply to the heating means based on weight.