KR0125709B1 - Cooking control method of microwave oven - Google Patents

Abstract

In a temperature sensing device of a microwave oven capable of performing an automatic cooking function of a sensor type, there is an internal air duct (11) where a suction port of a cavity (1) and a suction port provided far apart from an exhaust port are connected and internal air is guided, an external air duct (12) where a part of an air ventilated by a cooling fan (3) is sucked to be exhausted, an internal temperature sensor (21) sensing the temperature of an external air in a part of the exhaust port within the internal air duct (11), and a reference temperature sensor (22) sensing the temperature of the external air in a part of the exhaust port within the external air duct (12), and a controller controlling the cooking in the microwave oven reads voltage level due to a change of a resistance value of the temperature sensors (11 and 12) as a temperature value.

Description

Microwave temperature controller and cooking control method

1 is a structural diagram of a temperature sensing device for a microwave oven according to the present invention.

2 is a block diagram of a cooking control apparatus for implementing a temperature sensing cooking control method according to the present invention.

3 is a control flowchart of a temperature sensing cooking control method according to the present invention.

4 is a temperature waveform diagram for explaining a temperature sensing method according to the present invention.

* Description of the symbols for the main parts of the drawings *

1: Cavity 2: Cooling Fan

3: thick plate 11: high airflow duct

12: outside air duct 21, 22: temperature sensor

21a, 22a: temperature sensing circuit 30: microcomputer

31: display unit 32: load driving unit

33: keyboard 34: power circuit

The present invention relates to a temperature sensing device of a microwave oven and an automatic cooking control method according to temperature sensing. In particular, by detecting the temperature of the air inside the air and the outside air temperature blown by the blowing fan to cut off the food according to the comparison of the two temperatures. The present invention relates to a temperature sensing device and a cooking control method of a microwave oven for determining a point and controlling automatic cooking.

In the conventional sensor type microwave oven, the humidity sensor is installed on the exhaust port side where the high-temperature water vapor is exhausted, and the heating is started to determine that the food boils at a time when the humidity changes rapidly, that is, when the amount of change in the humidity becomes more than a preset reference value. The detection time from the start of heating until the boiling point is detected, the second heating time is obtained by multiplying the detection time by a predetermined addition factor, and then the heating is further performed during the second heating time to sort the cooking.

In addition, a conventional sensor type microwave oven may use a gas sensor instead of a humidity sensor, it is controlled similarly to the case of the humidity sensor.

However, the humidity sensor and gas sensor are installed on the exhaust duct outside the exhaust port to detect humidity and gas volume. Therefore, the air flows out through the exhaust port at high speed so that the air flowing through the sensor is unstable and accurate. Has the disadvantage that the sensing is unstable, such as the fall and the instantaneous control can occur.

In addition, the humidity sensor and gas sensor have become a cost increase factor at high prices.

In view of this, an object of the present invention is to provide a temperature sensing device and a cooking control method of a microwave oven that enable automatic cooking control by sensing a temperature in a stable air flow state.

As a means for achieving the object of the present invention, the air inside the high air flow duct and the outside air duct installed by the air blown by the cooling fan is installed, the air pressure as the air escapes through the outside air duct It is installed so that high air can be introduced into and discharged into the high air duct by a car, and a high temperature sensor and a reference temperature sensor are respectively installed in the high air duct and the outside air duct, and the controller is provided with two temperature sensors. It is characterized in that the cooking control to compare the temperature detected by the.

In addition, the controller of the microwave oven reads the temperature detection value from the temperature sensor and the reference temperature sensor while starting heating at the start of automatic cooking and counting the detection time, and the constant obtained by experiments on the temperature detection value inside the oven. Multiply the value, and add the constant value obtained by the experiment to the reference temperature detection value to detect the time when the two values are the same as the boiling point, find the detection time from the start of heating to the boiling point detection time, and at that time The secondary heating time is calculated by multiplying the magnetic field addition coefficients previously obtained according to the type, and further heating during the secondary heating time to sort the cooking.

According to the present invention, it is possible to stably detect the temperature through the thermistor by inducing high internal air of the slowest flow rate at the farthest side from the inlet and exhaust ports to the sensing duct, and detect the internal temperature and the reference temperature Since cooking control is performed by comparison with a value, accurate cooking control can be realized by a cheap temperature sensor.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a structure for installing a temperature sensor of a microwave oven according to the present invention, as shown in the air inlet and the exhaust port of the cavity (1) is connected to the inlet and the air inlet air duct (11) to guide the high internal air, and cooling, The air blown by the fan 3 is guided and the outlet port communicates with the outlet of the air inlet air duct 11 to discharge the air to the outside of the thick plate 3 and into the air inlet air duct 11 by a pressurized vehicle. Internal air ducts 12 for allowing internal air to be sucked in, respectively, internal air temperature ducts 11 and the internal air temperature sensor 21 and external air for detecting internal temperature at the outlet side inside the external air duct 12 Each reference temperature sensor 22 is installed to sense the temperature of the controller, and the controller for cooking control of the microwave is configured to read the temperature value detected by the temperature sensors 11 and 12 to perform cooking control. .

This apparatus forms an air through-hole for installing the high air intake duct 11 at the farthest side from the inlet and the exhaust in the cavity 1, and fixes the intake side of the high air inside the duct 11 to the through. Install.

The reason is to obtain the air for sensing at the slowest flow rate, whereby the sensing is possible in the most stable state.

In addition, the outside air duct 12 is exposed to the inlet port in the electrical equipment room, the outlet port is connected to the through hole of the thick plate 3 together with the outlet of the high air chamber duct (11).

Here, in the through-hole of the thick plate 3, the outlet of the internal air duct 11 and the external air duct 12 communicate with each other, and the air exits through the external air duct 12 to the internal air duct 11. Since the air on the outlet side exits together, suction force is generated according to the pressure difference, and the high internal air is introduced into the high internal air duct (11). However, because it is not a strong suction force, the flow rate is very slow, the temperature sensor 21 is able to detect the temperature in a stable state of air.

In addition, since the air for high temperature air duct 11 and the external air duct 12 need only flow for temperature sensing, the diameter does not need to be large, and thus the internal temperature of the high air duct 11 is not lowered.

Meanwhile, according to the present invention, the internal air duct 11 and the external air duct 12 are installed, and thermistor temperature sensors 21 and 22 are respectively installed therein to sense the temperature and control cooking. Apparatus for implementing a temperature-sensing cooking control method. As shown in FIG. 2, the temperature sensor 21 for internal temperature sensing and the voltage dividing resistor R1 are connected between the power supply terminal (+ 5V) and the ground, and the connection point is connected to the noise absorbing capacitor C1. The temperature sensor circuit 21a is connected to the A / D port A / D1 of the microcomputer 30, and the reference temperature sensing temperature sensor 22 and the voltage divider resistor R2 are connected to a power supply terminal. + 5V) and the ground, and the connection point is connected to the noise absorbing capacitor (C2), and connected to the A / D port (A / D2) of the microcomputer 30 to form a reference temperature sensing circuit (22a) A power supply circuit for supplying power voltages to the display unit 31 for displaying various types under the control of the microcomputer 30, the load driver 32 for driving various loads, the keyboard 33 for inputting operation key signals, and the respective units; 34 is included and configured.

Here, the temperature sensor circuit 21a and the reference temperature sensor circuit 22a of the air temperature sensor 21, 22 installed in the air air duct 11 and the external air duct 12, that is, the change in the resistance of the thermistor The temperature detection signal is input to the microcomputer 30 at the voltage level according to the present invention.

Accordingly, the microcomputer 30 reads the voltage level through the A / D port as digital data, and recognizes the internal temperature and the reference temperature based on the digital data to control cooking.

On the other hand, the method of cooking control based on the temperature data detected from the two temperature sensors 21 and 22 of the microcomputer 30, since the temperature sensor is used in two, a different program from the conventional cooking control You must proceed.

FIG. 3 is a main control flow diagram illustrating a method for controlling temperature sensing cooking of a microwave oven according to the present invention, and FIG. 4 is a flowchart of an additional time calculation and additional time count interrupt routine according to FIG. 3. The microcomputer 30 that senses the temperature through the sensors 21 and 22 and controls the cooking, when the automatic cooking of the sensor type is started, counts the sensing time T and detects the temperature of the air in the air. The voltage level of the temperature sensing circuit 21a is read through the input port A / D1 according to the change in the resistance of 21 (A / D1? A). Subsequently, the internal temperature sensed value A is multiplied by the constant value α obtained by the experiment (AA ← A * α). In addition, the voltage level of the temperature sensing circuit 22b is read through the input port A / D2 according to the change in the resistance of the temperature sensor 22 installed in the external air duct 12 to sense the reference temperature (A). / D2 → B). Subsequently, the constant temperature (+10) obtained by the experiment is added to the reference temperature detected value (B) (BB ← B + 10).

Thereafter, the calculated values AA and BB according to the two temperature values are compared with each other (AA = BB?). Here, the rate of rise of the outside air, that is, the air blown by the cooling fan and the high internal air temperature is different, but since the initial value is similar or the temperature of the external air is low, the two temperature waveforms cross as shown in FIG. In order to detect the boiling point as a boiling point, constant values (α) and (+10) necessary for the calculation are obtained in advance by cooking experiments, and the temperature detection values are multiplied and added to compare them.

If the two calculation values AA and BB are not equal to each other, the process of reading and calculating the temperature detection values is repeated until the two calculation values AA and BB are the same, and the calculation values AA and BB corresponding to the two temperature values are the same. When the food is boiling, the sensing time T counted up to that time is stored as the first heating time T1, and the addition obtained by the experiment according to the type of food in the first heating time T1. The secondary heating time T2 is obtained by multiplying the coefficient k.

When the secondary heating time T2 is obtained in this manner, it is determined whether the secondary heating time T2 is over by counting down the secondary heating time T2, and when the secondary heating time T2 ends, the heating is stopped. Cooking will end.

Therefore, as shown in FIG. 4, the temperature waveform (A * α = AA) obtained by multiplying the internal temperature detection value (A) by the rising value (α) and the reference temperature detection value (B) according to the external air temperature are constant. When the temperature waveform (B + 10 = BB) plus the value (+10) crosses each other as the boiling point, the additional coefficient (k) installed according to the type of food at the first heating time (T1) until the boiling point is detected Cooking is completed by further heating for the second heating time (T2 = T1 * K) multiplied by). At this time, the total cooking time is the time (T1 + T2) plus the first heating time (T1) and the second heating time (T2).

As described in detail above, according to the present invention, the internal air flows in a stable state to sense the temperature with a thermistor, and together with the reference temperature to detect the temperature of the outside air blown from the electrical equipment room to compare the two temperatures. According to the cooking control, there is an effect that can detect the internal temperature in a stable state, and cooking control in comparison with the detected reference temperature, it is possible to minimize the cooking deviation, thereby improving the reliability, It does not use expensive humidity sensor or gas sensor, so it is effective in cost reduction.

Claims (5)

In the microwave oven capable of performing automatic sensor type cooking function, the inlet and the exhaust port of the cavity (1) is connected to the inlet and the air inlet air duct (11) and the high-internal air is guided by the cooling fan (3) An internal air duct 12 and an external air duct are installed to respectively install external air ducts 12 through which a part of the blown air is introduced and discharged, and detect high internal air at an outlet side of the internal air duct 11. (12) respectively installed a reference temperature sensor 22 for sensing the temperature of the outside air at the outlet side of the inside, the controller for cooking control of the microwave oven to the variable resistance of the temperature sensor (11) (12) Temperature sensing device of the microwave oven, characterized in that configured to read the voltage level by the temperature value. The temperature sensing device of the microwave oven according to claim 1, wherein the temperature sensor (21) (22) is a thermistor whose resistance is variable according to temperature. The air freshening duct (11) according to claim 1, wherein the air freshening duct (11) is formed in the cavity (1) to form an air through hole for installing the fresh air duct (11) farthest from the inlet and the exhaust opening. The air inlet side of the air duct 11 is fixedly installed, and the outside air duct 12 has an inlet port exposed in the electric compartment and an outlet port of the thick plate 3 together with the outlet port of the air duct 11. It is connected to the microwave oven, characterized in that made by the air discharge of the air air duct 11 by the air discharge of the external air duct 12, the high air is slowly introduced into the high air duct 11 and discharged Temperature sensing device. A microwave oven configured to detect a temperature by installing a high temperature air duct and an external air duct and installing a high temperature sensor and a reference temperature sensor in the duct respectively, wherein the controller of the microwave oven starts heating at the start of automatic cooking. Starting and counting the detection time, reading the temperature detection value from the internal temperature sensor and the reference temperature sensor, multiplying the internal temperature detection value by an arbitrary constant obtained by an experiment, and multiplying the reference temperature detection value by Repeating the temperature sensing until the two values are equal to each other by adding another constant value obtained by the experiment; and the sensing time from the start of heating to the time when the two calculated values calculated by the constant are equal to each other. The stored part obtained by experiment in accordance with the type of food at the step of obtaining and the detection time Step and the second heating time more heat to the temperature sensing cooking control method for a microwave oven, characterized in that arranged to terminate the cooking while multiplying the coefficient calculating a second heating time. 5. The method of claim 4, wherein the constant value multiplied by the inside temperature detection value and the other constant value added to the reference temperature detection value are different from each other when the waveform of the inside temperature detected by the cooking experiment and the waveform of the reference temperature are at the time of boiling of the food. Cooking temperature control method of a microwave oven, characterized in that the constant value obtained by the experiment in consideration of the initial value and the increase rate of the internal temperature and the reference temperature so as to cross.