KR101139770B1 - Exclusive inner pan judging apparatus for induction heating cooker - Google Patents

Abstract

The present invention is to accurately determine whether the appropriate dedicated inner pot is inserted into the induction heating cooker by compensating the input current for determining the dedicated inner pot according to the magnitude of the input voltage supplied to the induction heating cooker, commercial power and inverter resonance circuit An input current sensing unit for sensing an input current flowing between the furnace and an input voltage sensing unit for sensing an input voltage from a commercial power source, and the microcomputer performs induction heating by an inverter resonance circuit, and inputs during this induction heating. Based on the magnitude of the input voltage from the voltage sensing unit, the value of converting the input current or the input current from the input current sensing unit into voltage is compensated, and the value of converting the compensated input current or the compensated input current into voltage. Using to determine whether the object inserted into the heating space is a dedicated inner pot.

Description

Dedicated inner pot discrimination device for induction cooker {EXCLUSIVE INNER PAN JUDGING APPARATUS FOR INDUCTION HEATING COOKER}

The present invention relates to a dedicated inner pot discrimination apparatus of an induction heating cooker, in particular, by compensating the input current for determining the dedicated inner pot according to the magnitude of the input voltage supplied to the induction heating cooker, an appropriate dedicated inner pot is inserted into the induction heating cooker It relates to a dedicated inner pot determination device of the induction heating cooker that can accurately determine whether.

The induction heating cooker is composed of a main body, an inner pot containing food and seated inside the main body, and a cooking heater and an induction heating coil mounted on the lower portion of the inner pot or the inner side of the main body so that the food contained in the inner pot is cooked.

The cookers may be classified according to a method of providing cooking heat to the inner pot, and coils are formed at a predetermined interval on the main body portion on which the inner pot is seated, so that eddy currents are formed in the inner pot formed of a magnetic body by a magnetic field generated as a current flows in the coil. A cooker that heats the inner pot by being generated is called an induction heating cooker.

1 is a block diagram of the inner pot detection device of the induction heating cooker according to the prior art. As shown in FIG. 1, the inner pot detecting device is connected to a current sensing unit 1 for detecting a current of a commercial AC power applied to an induction heating cooker, and an induction heating coil L (eg, a cooking heater). In addition, by generating a high output voltage from the commercial AC power applied by switching the switching element is applied to the coil (L), induction heating of the inner pot and the food contained in the inner pot, to the sense current from the current sensing unit (1) An inverter circuit 2 for applying a corresponding inner pot detection signal to an input terminal of the microcomputer 3 and a microcomputer 3 for controlling cooking of food by applying a control signal to the inverter circuit 2.

A microcomputer protection resistor R1 is connected in series between the inverter circuit 2 and the input terminal of the microcomputer 3, and a noise eliminating capacitor C1 and a pull-down resistor R2 are connected between the input terminal of the microcomputer 3 and the ground. ) Are connected in parallel, and the inner pot detection signal from the inverter circuit 2 is applied to the microcomputer 3.

If cooking is started after the AC power is applied to the induction heating cooker, when the inner pot is seated, the current of the entire induction cooker is increased. On the contrary, when the inner pot is not seated, a relatively low current flows. This current is applied by the current sensing unit 1 to the inverter circuit 2 by converting the voltage, and the inverter circuit 2 (exactly the microcomputer in the inverter circuit 2) is converted from the current sensing unit 1. When the voltage is equal to or higher than a predetermined value, the inner pot detection signal, which is a high signal, is applied to the microcomputer 3, and in the opposite case, the inner pot detection signal, which is a low signal, is applied to the microcomputer 3. Through this process, the microcomputer 3 determines whether the inner pot is seated. These inner pot detection signals are applied to the microcomputer 3 through the inner pot detection port P of the inverter circuit 2.

However, when a foreign substance having a metal component other than a dedicated inner pot is inserted into the main body, the inverter circuit 2 applies a high voltage to the coil L, so that the current of the entire induction heating cooker increases, thereby increasing the current of the inverter circuit 2. Since the voltage value applied from the current sensing unit 1 is greater than or equal to a certain magnitude, the inverter circuit 2 may apply a HIGH signal to the microcomputer 3. In addition, when the inner pot cover (or the oven cover) is detachable, the same problem may occur even when the inner pot cover is separated from the lid in the state where the inner pot is not inserted into the main body, and inserted into the main body.

In addition, the voltage value detected by the current sensing unit 1 varies according to the magnitude of an input voltage which is an external commercial power source applied to an induction heating cooker. For example, if the input voltage is low, even if the normal inner pot is inserted, the detected voltage value is low, and heating may not be performed. On the other hand, if the input voltage is high, the inner pot cover, knife, and spoon are not the normal inner pot. Even when an object of the Venus component such as the like is inserted, the detected voltage value becomes high, and there is a problem that heating is performed.

It is an object of the present invention to provide a dedicated inner pot determination device of the induction heating cooker to accurately determine whether the dedicated inner pot is inserted into the main body.

In addition, an object of the present invention is to provide a dedicated inner pot determination device of the induction heating cooker to compensate for the detected input current, even if the size of the external commercial power applied is changed, to enable accurate dedicated inner pot determination.

In addition, an object of the present invention is to provide a dedicated inner pot determination apparatus of the induction heating cooker to accurately determine the dedicated inner pot, based on the magnitude of the input current or the value of the value converted from the input current to the voltage compensated in the inner pot determination process. do.

Dedicated inner pot determination device of the induction heating cooker of the present invention is an induction heating cooker having a main body having a heating space, an inverter resonant circuit for switching the induction heating by applying a commercial power supply, and a microcomputer to control the inverter resonant circuit. An apparatus for determining an internal pot, comprising: an input current sensing unit configured to sense an input current flowing between a commercial power source and an inverter resonance circuit; An input voltage sensing unit for sensing an input voltage from a commercial power source is provided, and the microcomputer performs induction heating by an inverter resonance circuit, and based on the magnitude of the input voltage from the input voltage sensing unit during the induction heating, Compensate the value of the input current or the input current from the current sensing unit to the voltage, and by using the value of the compensated input current or the compensated input current to the voltage, whether the object inserted into the heating space is a dedicated inner pot. The microcomputer determines whether the compensated input current or the compensated input current is converted into voltage and is the amount of change in the value of the compensated input current or the compensated input current converted into a voltage for a predetermined time after the determination start voltage or more. When the difference in voltage is greater than the reference voltage difference by comparing the voltage difference with the reference voltage difference, the object inserted into the heating space is a dedicated inner pot. A judgment.

In addition, the microcomputer according to the present invention performs a negative compensation when the magnitude of the input voltage is greater than the reference input voltage, and performs a positive compensation when it is smaller than the reference input voltage.

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In addition, the determination start voltage is larger than a value indicating the input voltage before performing induction heating by voltage.

The present invention accurately determines whether the dedicated inner pot is inserted into the main body,

By preventing unnecessary heating or cooking process, there is an effect to enable the stable use of the induction cooker.

In addition, the present invention compensates the sensed input current even if the size of the external commercial power applied is changed to enable accurate dedicated inner pot determination, thereby improving the reliability and safety of the induction cooker.

In addition, the present invention has an effect of accurately determining the dedicated inner pot on the basis of the amount of the input current or the value of the value converted from the input current or the current compensated according to the magnitude of the input voltage.

1 is a block diagram of the inner pot detection device of the induction heating cooker according to the prior art.
2 is a block diagram of a dedicated inner pot determination apparatus of the induction heating cooker according to the present invention.
3 is a graph of input current according to a change in input voltage.
4 is a graph of input current compensated by the dedicated inner pot determination apparatus of FIG. 2.
5 is an embodiment of a determination method performed by the dedicated inner pot determination apparatus of FIG. 2.

In the following, the invention is described in detail with reference to the embodiments and drawings.

A general induction heating cooker basically includes a main body (not shown) having an upwardly opened heating space therein, a main body lid (not shown) installed on the upper surface of the main body so as to be opened and closed, and detachably installed inside the heating space. It is configured to include a dedicated inner pot (not shown) in which control such as cooking and keeping warm in the opened inner space. The food is accommodated in the dedicated inner pot, and cooking and warming control are performed.

2 is a block diagram of a dedicated inner pot determination apparatus of the induction heating cooker according to the present invention.

The induction heating cooker is basically supplied with commercial power and rectified through the bridge diode (BD1), and the rectified power is smoothed through the choke coil (CH) in the smoothing capacitor (C3) and supplied to the resonator unit. Here, the resonator unit is composed of a heating coil L and a resonant capacitor C4, and the on / off operation of the resonator unit is performed by the driving of the switching element Q1. Resonators are formed in the lower or side surfaces of the heating space corresponding to the dedicated inner pot.

In addition, the switching element driving circuit 10 turns on / off the switching element Q1 by a control signal from the microcomputer 20, and the on / off operation of the switching element Q1 is performed by the heating coil L of the induction heating cooker. ) To generate heat. The resonant capacitor C4 is used for the purpose of attenuating back EMF generated from the heating coil L when the switching element Q1 is turned off.

The above-described part is an inverter resonant circuit of the induction heating cooker, and are elements provided for induction heating of the induction heating cooker. The microcomputer 20 controls the inverter resonance circuit according to a cooking algorithm according to the selected menu to perform cooking.

In addition, the induction heating cooker includes an input unit 12 for acquiring an input such as a menu selection from a user, a speaker 14 for acoustically informing necessary information, and a display unit 16 for visually informing necessary information. The microcomputer 20 performs selection and control according to an input from the input unit 12, and informs the outside of necessary information through an information transfer unit consisting of a speaker 14 or a display unit 16.

Dedicated inner pot determination device according to the present invention is a current transformer (CT) formed between the input terminal of the commercial power supply and the bridge diode (BD1) of the inverter resonance circuit, bridge diode (BD2) for rectifying the output of the current transformer (CT), and rectification And an input current sensing unit having voltage divider resistors R3 and R4 for dividing the output, and a smoothing capacitor C5 for smoothing the divided output, for applying an input current to the terminal IC of the microcomputer 20. . The input current detector detects a current flowing between the commercial power supply and the inverter resonance circuit.

In addition, the dedicated inner pot determination device is connected to both ends of the commercial power source, respectively, diodes (D1) and (D2) for converting the input alternating current into direct current, distribution resistors (R5 and R6) for distributing the converted power, and distributed And a smoothing capacitor C6 for smoothing the power supply and applying an input voltage to the terminal IV of the microcomputer 20.

In this embodiment, a power supply unit for applying power to the microcomputer 20, the switching element driving circuit 10, the input unit 12, the speaker 14, the display unit 16, etc. is not shown, but such a power supply unit is provided. It is only a matter of course recognized by those familiar with the technical field to which the present invention belongs, and the description thereof is omitted.

Before performing the cooking process, the microcomputer 20 generates a control signal for turning on the switching element Q1 for a short time in order to determine whether an appropriate dedicated inner pot is mounted in the heating space, and thereby the switch element driving circuit 10 ) Is applied.

When the switching element Q1 is turned on, a current flows in the heating coil L, and an induction current flows through heat generated by a magnetic inner wire or an object of a dedicated inner pot or a metal component, which generates heat. It is input to the microcomputer 20 through. That is, the input current detected when the dedicated inner pot of normal load is inserted into the heating space is higher than the input current detected when non-dedicated objects such as inner pot cover, knife, and cutlery are inserted into the heating space.

3 is a graph of input current according to a change in input voltage. In FIG. 3, the X axis represents an input voltage, and the Y axis represents an input current (or a value obtained by changing the input current into a voltage) according to the change of the input voltage. As shown in FIG. 3, as the input voltage increases, the input current curve S1 also increases when the dedicated inner pot is mounted. For example, the input current when the inner pot cover is inserted into the heating space. The curve S2 and the input current curve S3 when an object such as a knife or cutlery is inserted into the heating space also increase. In FIG. 3, the curve CV corresponds to a reference value curve for discriminating the dedicated inner pot. As shown in FIG. 3, when the curve CV is kept constant regardless of the change in the magnitude of the input voltage, the input current on the curves S2 and S3 is curved according to the magnitude of the input voltage. When the value is greater than the reference value, the microcomputer 20 determines that the object is currently inserted as the dedicated inner pot, even when the dedicated inner pot is not mounted, and thus can perform a cooking algorithm.

In order to solve this problem, the microcomputer 20 needs to compensate the input current according to the magnitude of the input voltage.

4 is a graph of input current compensated by the dedicated inner pot determination apparatus of FIG. 2. In FIG. 4, the microcomputer 20 sets, for example, 220V as the reference input voltage, performs a positive compensation for the input current at less than 220V, and input current in the case of an input voltage exceeding 220V. Perform negative compensation for. By this compensation, the curves SC1, SC2, and SC3 that compensate the curves S1, S2, and S3 are adjusted so that the slope becomes close to zero or becomes a small value. The reference value curve CV may be set to a constant value that does not meet the curves SC2 and / or SC3 even if the magnitude of the input voltage varies, as in the reference value curve CV of FIG. 4.

In addition, in the graph of FIG. 3, for example, by setting 175V as the reference input voltage, compensation is not performed for the input current at 175V, and negative for the input current when the input voltage exceeds the reference input voltage. You can perform a negative compensation.

When the microcomputer 20 compensates for the input current, as shown in FIG. 3, the degree of compensation for the input current (positive compensation degree, negative compensation degree) is equal to the input current of the dedicated inner pot, even if the input voltage changes. The input current of the dedicated inner pot (eg, an inner pot cover, a knife, a cutlery, etc.) should be set to a value such that the input current does not overlap with the reference value. The microcomputer 20 stores the set compensation degree, compensates the detected input current (or a value indicating the input current as a voltage) according to the magnitude of the input voltage, and applies the same to FIG. 5 below.

5 is an embodiment of a determination method performed by the dedicated inner pot determination apparatus of FIG. 2. The input current (or a value representing the input current as a voltage) below corresponds to a value in which the microcomputer 20 compensates according to the magnitude of the input voltage as shown in FIG. 4.

Before the input power is applied to the resonator unit to perform the induction heating, the value indicating the compensated input current (or initial current) as a voltage corresponds to the initial voltage Vi. When the microcomputer 20 starts induction heating for discriminating the dedicated inner pot, a voltage curve V1 indicating the compensated input current of the dedicated inner pot as a voltage, and an object capable of induction heating without using the inner pot (for example, A voltage curve V2 representing the compensated input current of the separate inner pot cover) is shown in FIG. 5.

As shown in the lower graph of FIG. 5, the microcomputer 20 has each of the compensated voltages of the voltage curve V1 and the voltage curve V2 determined from the determination start voltage Vi + a (where a is equal to 0.15V, for example). After reaching the voltage level, a voltage when a predetermined time (for example, 30 ms) has elapsed is applied from the input current sensing unit, and compensated to be used as the discrimination termination voltage. The microcomputer 20 may calculate the discrimination voltage difference (the discrimination end voltage-the discrimination start voltage), respectively.

As shown in Fig. 5, on the voltage curve V1 of the dedicated inner pot, the time when the voltage reaches the determination start voltage Vi + a is t1, and the voltage after a predetermined time from t1 to t2 is the determination end voltage. Corresponds to On the voltage curve V2 of the non-dedicated inner pot, the time at which the voltage reaches the determination start voltage Vi + a is t3, and the voltage after a predetermined time from t3 to t4 corresponds to the determination end voltage. Here, the time interval t1-t2 and the time interval t3-t4 correspond to the same time.

The microcomputer 20 stores a dedicated inner pot and a reference voltage difference for discriminating the non-dedicated inner pot, and compares the reference voltage difference with the discriminating voltage difference to determine whether the object currently inserted into the heating space is the dedicated inner pot. do. As shown in Figure 5, to determine a voltage difference (ΔV1) of the time interval (t1-t2) can be found in size is great as compared to determine a voltage difference (ΔV2) of the time interval (t3-t4). Accordingly, the reference voltage difference is set to be larger than the discriminating voltage difference of the non-dedicated inner pot, and smaller than the discriminating voltage difference of the dedicated inner pot, and the microcomputer 20 determines that the discriminating voltage difference is smaller than the reference voltage difference, and determines the discriminating inner pot. If the difference is greater than the reference voltage difference, it is determined as a dedicated inner pot.

When the microcomputer 20 starts induction heating, the input current gradually increases even if the non-dedicated inner pot or induction heating is possible by induction heating, but the increase is smaller than that of the dedicated inner pot. By using it can determine whether the dedicated inner pot.

As described above, the microcomputer 20 performs a dedicated inner pot discrimination process by using the value represented by the compensated input current or the compensated input current as a voltage, and stops induction heating and transmits information when the dedicated inner pot is not. Through wealth, visually or audibly informs that the currently inserted object is not a dedicated inner pot. By stopping the induction heating and information notification, it is possible to prevent the induction heating cooker from unnecessarily heating or burning of the product due to the heating of the object not to be heated. The user can check the information and remove the object in the heating space.

In addition, in the dedicated inner pot determination process, in the case of the dedicated inner pot, the microcomputer 20 performs cooking according to the selected menu. The microcomputer 20 may transmit to the outside that the object inserted into the current heating space is a dedicated inner pot through the information transfer unit.

Hereinafter, the present invention has been described in detail based on the embodiments of the present invention and the accompanying drawings. However, the scope of the present invention is not limited by the following embodiments and drawings, and the scope of the present invention will be limited only by the contents described in the claims below.

Claims (5)

In the dedicated inner pot discrimination apparatus of the induction heating cooker having a main body having a heating space, an inverter resonant circuit for switching induction by applying a commercial power supply to perform induction heating, and a microcomputer for controlling the inverter resonant circuit,
An input current detector for detecting an input current flowing between the commercial power supply and the inverter resonance circuit;
An input voltage sensing unit for sensing an input voltage from a commercial power source is provided, and the microcomputer performs induction heating by an inverter resonance circuit, and based on the magnitude of the input voltage from the input voltage sensing unit during the induction heating, Compensate the value of the input current or the input current from the current sensing unit to the voltage, and by using the value of the compensated input current or the compensated input current to the voltage, whether the object inserted into the heating space is a dedicated inner pot. Determine,
The microcomputer includes a discrimination voltage difference, which is a change amount of a value obtained by converting a compensated input current or a compensated input current into a voltage for a predetermined time from when the value of the compensated input current or the compensated input current to voltage is equal to or greater than the discrimination start voltage. And comparing the reference voltage difference, and when the discrimination voltage difference is greater than the reference voltage difference, it is determined that the object inserted into the heating space is a dedicated inner pot. The induction heating cooker of claim 1, wherein the microcomputer performs negative compensation when the magnitude of the input voltage is greater than the reference input voltage, and performs positive compensation when it is smaller than the reference input voltage. Dedicated inner pot determination device. delete delete The apparatus of claim 1, wherein the determination start voltage is greater than a value represented by a voltage representing the input current before the induction heating is performed.

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