JP2697262B2 - High frequency heating equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating device for achieving automatic thawing of food.

2. Description of the Related Art Conventionally, as means for achieving automatic thawing of a high-frequency heating device, a turn as a uniformizing means for uniformly heating a food 2 placed in a heating chamber 1 as shown in FIG. Weight sensor 4 for measuring the weight of food 2 on table 3
, And thawing is performed according to the detected weight. However, this means cannot be automated in the case of a high-frequency heating device that does not use the turntable 3. When it was used, it was heated and boiled by that much weight. In addition, the weight sensor 4 can obtain only information on only the weight,
The amount of heating was not adjusted according to conditions such as the starting temperature of the heating.

However, if the weight sensor 4 is used, it is impossible to determine a difference in state such as the starting temperature of the food 2, and boiling may occur in the case of thawing a food having a high starting temperature. There was sex.

Therefore, the intensity of the electric field in the heating chamber 1 is detected by the antenna 5 and a high frequency having a means for determining the cooking time based on the output obtained from the detecting means 7 for each cycle of the turntable 3 as the equalizing means. A first object is to provide a heating device.

It is a second object of the present invention to provide a control means having a judgment means for judging the state of the food based on the output.

It is a third object of the present invention to provide a control means for determining the cooking time more appropriately according to the state of the food determined by the amount of change in the output.

It is a fourth object of the present invention to provide a control unit that changes the time for determining the state of the food according to the size of the food so that more appropriate cooking can be performed.

Means for Solving the Problems In order to achieve the first object, the present invention relates to a method for uniformly heating food in a heating chamber, the method comprising: It has control means having a conversion function for determining the high-frequency output and time for decompression from the maximum value of the output.

Further, in order to achieve the second object, the present invention has a control means for judging a state of a food based on the magnitude of change of the plurality of outputs.

Further, in order to achieve the third object, the present invention provides a method for converting a maximum value of a plurality of outputs obtained from the detection means into a cooking time according to a determined food state. And a control means for determining the high-frequency output used for heating the food and the time of the output using the above conversion formula.

In order to achieve the fourth object, according to the present invention, the time for judging the state of the food is set to an integral multiple of the rotation period of the uniform means in accordance with the magnitude of the change in the plurality of outputs obtained from the detection means. It has a control means having a mode for reducing the time.

The high-frequency heating device according to the present invention detects a high-frequency signal from an antenna for detecting the intensity of an electric field in the heating chamber by a detection unit, and outputs a signal from a plurality of detection units output for each rotation cycle of the equalization unit. The high frequency output used for defrosting the food and the cooking time thereof are determined by the conversion means on the basis of the maximum value of, and automation of defrosting can be achieved.

Further, the high-frequency heating device according to the present invention can estimate the state of the food based on the magnitude of the amount of change in the plurality of outputs from the detecting means for each rotation cycle of the equalizing means.

Further, the high-frequency heating device of the present invention determines the state of the food so that the cooking time corresponding to the state can be optimally thawed using a plurality of conversion means.

Further, the high-frequency heating device of the present invention, the maximum value of the plurality of outputs obtained from the detection means, the time required to estimate the initial temperature of the food, when the food weight is small, the rotation period of the uniformization means Can be shortened by an integral multiple of the time,
In the case where the food weight is small, it is possible to prevent the food from boiling during estimation.

Embodiment Hereinafter, a high-frequency heating device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram of the main body of the high-frequency heating device according to one embodiment of the present invention. The food 2 in the heating chamber 1 is thawed by the high-frequency radiation means 6 controlled by the control means 9.
The magnitude of the electric field in the heating chamber 1 depending on the size of the food 2 and the heating chamber 1 that changes with the progress of thawing of the food 2
The change in the intensity of the electric field inside the heating chamber 1 is shorter than the 高周波 wavelength of the oscillating frequency of the high-frequency radiation means 6 coupled to the heating chamber 1 by the high frequency leaking from the coupling hole 8 provided on the wall surface of the heating chamber 1. The signal is received by the antenna 5 and its intensity is detected by the detection means 7 as a voltage output. The signal is converted into a voltage output by the detection means 7, and based on this output, the high-frequency radiation means 6 is controlled by the control means 9 to perform cooking.

Here, the cooking control will be described with reference to the flowchart of FIG. In order to stabilize the anode temperature characteristic of the oscillation of the high-frequency radiating means 6 for 4 seconds after the start of cooking, the high-frequency radiating means 6 is cooled by a fan (this period is called a fan mode), and then the high-frequency radiating means 6 is driven. For six seconds after the driving, the reading of the signal is masked for stabilizing the oscillation of the high-frequency radiation means 6 (this period is called a mask mode). After that, the antenna 5
The high-frequency signal received at (1) is detected by the detection means 7 and converted into a voltage output. The converted voltage output is A / D-converted by a microcomputer which is the control means 9 and is equalized by the microcomputer 3.
Is integrated over the rotation cycle of the turntable, and the integrated value is divided because of the added data, and is output as an averaged output. Since the output stability is poor with only the data of the first initial rotation, the data of the maximum value of the two outputs up to the second rotation of the equalizing means 3 is used. If the food 2 is small, the amount of radio waves absorbed by the food 2 is small, and the intensity of the electric field in the heating chamber 1 increases, and as a result, the voltage output increases. Conversely, if the food 2 is large, the voltage output will be small. In this way, 2
By converting the maximum value V _Max of the two outputs into the cooking time t using a conversion curve as shown in FIG. 3, automation of thawing can be achieved.

After the start of cooking, the fan mode is set for 4 seconds to stabilize the high-frequency radiating means 6, and then the high-frequency radiating means 6 is driven. After the driving, the signal is read for 6 seconds to stabilize the oscillation of the high-frequency radiating means 6. Set the mask mode for masking. Thereafter, the signal is integrated and averaged for each rotation cycle of the turntable of the equalizing means 3 to obtain an output for each rotation cycle. Then, when the turntable of the equalizing means 3 makes three rotations, the difference between the minimum value of the output of the first and second rotations and the minimum value of the output of the first to third rotations (hereinafter referred to as SA), and 1
Considering the amount of change in the two outputs, which is the absolute value of the difference between the outputs of the second to third rotations (hereinafter referred to as SB), a matrix for determining the state (starting temperature) of the food 2 as shown in FIG. create.

Here, the amount of change in SA is divided into three, and the amount of change in SB is divided into two, so that the cases are divided into a total of six cases. C.) When the starting temperature is high (about -10 ° C.), B. The starting temperature is classified into three starting temperatures in the middle between A and C.

Here, the amount of change in the output is due to the temperature dependence of the dielectric loss of the food 2 as shown in FIG. 6. If the dielectric loss is small, the amount of reflection of the food 2 is large, and the electric field in the heating chamber 1 is strong. It gets stronger. Conversely, if the dielectric loss is large, the intensity of the electric field in the heating chamber 1 becomes weak. The dielectric loss increases linearly from −20 ° C. to 0 ° C. Therefore, if the starting temperature of −20 ° C. and the starting temperature of −10 ° C. are to be thawed to a certain temperature, the change in the dielectric loss changes. The amount is a at −20 ° C., −20
In the case of ° C., b (a> b), and the lower the starting temperature of the food 2 is, the larger the amount of change in SA and SB becomes, and the starting temperature of the food 2 can be determined based on this principle.

Next, a control method for determining the cooking time based on the output from the detection means 7 will be described with reference to FIG.

As described above, between the size of the food and the maximum value of the output according to the rotation cycle of the uniforming means 3 from the detection means 7,
Since the amount of high-frequency absorption varies depending on the size of the food item 2, there is a correlation, and the correlation can be converted into a conversion formula to determine the cooking time from the maximum output value. However, even if the state such as the starting temperature of the food 2 can be determined, even if the maximum value of the output is the same, the cooking time will be different if the starting temperature is different, so as shown in FIG. By using a plurality of (three in this case) conversion curves, it is possible to set a detailed cooking time according to the starting temperature of the food 2.

Here, when the maximum value of the output and V _Max, when the starting temperature food 2 is low (approximately -20 ° C.), the cooking time using the A transformation curve is determined as t _a. However, the higher the starting temperature food 2 (-10 ° C. approximately) Cooking time determines the cooking time is short t _c than t _a using the C conversion curve, the start temperature higher partial discreet cooking time You have set.

On the other hand, the food 2 is continuously heated while the starting temperature of the food 2 is being estimated from the change amount of the output value for three rotations calculated for each period of the equalizing means from the detection means 7 as described above. Have been. Therefore, especially in the case of a very small load of about 100 g or less, boiling may occur during the determination of the start temperature, and as shown in FIG.
After performing the mask mode for 6 seconds, when two outputs up to the second rotation of the turntable of the equalizing means 3 are obtained, 2
If the maximum value of the two outputs is equal to or more than a certain value, it is determined that the load is extremely small, the acquisition of the data of the third rotation of the turntable of the equalizing means 3 is stopped, and the output of the second rotation is stopped. The starting temperature is determined by dividing the amount of change, that is, the amount of change in SB into two parts, and control is performed to determine the cooking time in accordance with the state of the determined food. Is prevented from occurring. Effect of the Invention As described above, in the high-frequency heating device of claim 1,
There is an effect that the cooking time for thawing can be automatically determined from the maximum value of the output values of a plurality of rotations averaged for each cycle of the means for equalizing the electric field in the heating chamber.

Further, the high-frequency heating device according to claim 2 has an effect that the state of the food can be estimated from the amount of change in the output from the detection means.

Further, the high-frequency heating device according to the third aspect has an effect that by adjusting the heating time according to the determined state of the food, it is possible to realize fine thawing without boiling or the like.

Further, the high-frequency heating device according to claim 4 can prevent the possibility that a minimum load may cause a problem such as boiling during the determination of the state of the food by ending the determination early so that it can be prevented beforehand. Has the effect that can be.

[Brief description of the drawings]

FIG. 1 is a flowchart of control of a high-frequency heating device in one embodiment of the present invention, FIG. 2 is a cross-sectional view of the device, FIG. 3 is a characteristic diagram illustrating the principle of cooking time determination of the device, and FIG. FIG. 5 is a flow chart for determining the starting temperature of food in the apparatus, FIG. 5 is a matrix diagram for determining the starting temperature of the apparatus, FIG. 6 is a characteristic diagram illustrating the principle of determining the starting temperature of food, and FIG. FIG. 8 is a flow chart of the shortening judgment of the apparatus, and FIG. 9 is a sectional view of a conventional high-frequency heating apparatus. 1 ... heating chamber, 2 ... food, 3 ... uniformizing means, 5 ...
Antenna, 6 high frequency control means, 7 detection means, 9
... Control means.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Tomomi Moriyama 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. In-company (72) Inventor Koji Yoshino 1006 Kadoma, Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (56) References JP-A-61-208439 (JP, A) JP-A-59-71290 (JP, A) ) Tokiko 52-2133 (JP, B2)

Claims (4)

(57) [Claims] 1. A heating chamber for heating food, high-frequency radiating means for supplying high-frequency power to the heating chamber, uniformizing means for uniformly heating the heating chamber, and detecting the intensity of an electric field in the heating chamber. An antenna provided outside the heating chamber, a detecting means for detecting a high-frequency signal from the antenna, and a control means for taking in an output from the detecting means and controlling the high-frequency radiating means; A high-frequency heating apparatus having a conversion means for converting a maximum value of a plurality of rotations or more of an output from the detection means output for each rotation cycle of the means into a cooking time. 2. A heating chamber for heating food, high-frequency radiating means for supplying high-frequency power to the heating chamber, uniformizing means for uniformly heating the heating chamber, and detecting the intensity of an electric field in the heating chamber. An antenna provided outside the heating chamber, a detecting means for detecting a high-frequency signal from the antenna, and a control means for taking in an output from the detecting means and controlling the high-frequency radiating means, wherein the control means A high-frequency heating apparatus having a determination unit that determines the state of the food based on the amount of change in the output from the detection unit that is output for each rotation cycle of the conversion unit over a plurality of rotations. 3. The control means according to claim 1, further comprising a plurality of conversion means for converting the maximum value of the output from the detection means into the cooking time in accordance with the state of the food determined by the amount of change in the output. High frequency heating device. 4. A heating chamber for heating food, high-frequency radiating means for supplying high-frequency power to the heating chamber, uniformizing means for uniformly heating the heating chamber, and detecting the intensity of an electric field in the heating chamber. An antenna provided outside the heating chamber, a detecting means for detecting a high-frequency signal from the antenna, and a control means for taking in an output from the detecting means and controlling the high-frequency radiating means, wherein the control means comprises the detecting means A high-frequency heating device having a mode in which the time for determining the state of the food according to the maximum value of the output from the unit is shortened by an integral multiple of the rotation cycle of the uniformizing means.