KR100206813B1 - Heating cooker - Google Patents

Abstract

The present invention relates to a plurality of induction heating rice cookers and a cooking method thereof. Conventionally, since the limit capacity of a commercial rice cooker is 3 kW for 25 persons, a rice cooker with a larger capacity can not be manufactured. When the capacity of the rice cooker is increased, There was a problem that it was deteriorated. Accordingly, the present invention is configured to include one inverter and two or more working coils capable of heating a load, and two or more loads so that rice can be cooked at a maximum capacity of 50 servants or more without increasing power consumption, Thereby making it possible to drastically reduce the deterioration of rice cooker taste.

Description

Induction heating cooker with multiple loads and its cooking method

[0001] The present invention relates to an induction heating cooker capable of drastically reducing the deterioration of rice taste of a rice cooker for a heat plate type household appliance, and more particularly, it is possible to cook rice cookers having a maximum capacity of 50 servings or more without increasing power consumption, And more particularly, to an induction heating cooker having a plurality of loads and a method of cooking the same.

As a conventional induction heating circuit configuration of the cooker, shown in Figure 2, by smoothing the power that is input and making the output into a direct-current voltage (Vd), as well as the filter capacitors (C _f) and to improve the power factor of the input voltage ; A heating unit 10 composed of a working coil L _r1 and a resonance capacitor C _r1 (C _r2 ) operating with a voltage inputted through the filter capacitor C _f to heat the heating plate; And a switch S1 and S2 for supplying power to the heating unit 10 so as to perform a heating operation.

The conventional technique configured as described above will be described as follows.

The conventional rice cooker for domestic use only requires only 25 servings. This is because the contract power of each business in Korea is only 5kW, so it can be said that 3kW is the maximum capacity that can be used as a commercial rice cooker.

This is about 25 servings.

The basic circuit of the rice cooker for 25 persons is shown in Fig. 1, and the operation of the half bridge inverter will be described with reference to Fig.

Respectively supply the direct-current voltage (Vd) made by smoothing the input power from the filter capacitor (C _f) for the switch (S1, S2) and the heating element (10).

At this time, when the switch S2 is first turned off and the switch S1 is turned on, the input voltage V _d is applied to the resonance tank composed of the working coil L _r1 and the resonance capacitors C _r1 and C _r2 through the switch S1 So that the resonance starts and the current rises in the working coil L _r1 .

When the switch S1 is turned off before the resonance half period passes, the auxiliary capacitors C _r1 and C _{r2 perform} the auxiliary resonance with the resonance tanks L _r1 and C _r1 and C _r2 so that the voltage of the auxiliary capacitor C _a2 becomes V _d To zero and the voltage of the auxiliary capacitor (C _a1 ) rises from zero to V _d .

Since the anti-parallel diode (D _a2) of the switch (S2) is conductive it is subjected to zero-voltage resonant tank capacitor (L _r1 and C _r1, C _r2).

Then, resonance occurs continuously by the voltage charged in the resonance capacitors C _r1 and C _r2 , and the switch S2 is turned on under the zero voltage condition.

The resonance current is reduced to zero by the subsequent resonance, and the resonance current is increased by the resonance in the opposite direction at this time.

When the switch S2 is turned off before the resonance half period passes, the auxiliary capacitors C _a1 and C _a2 perform auxiliary resonance with the resonance tank so that the voltage of the auxiliary capacitor C _a1 falls to zero to the voltage V _d, The voltage of _a2 rises from zero to V _d .

Since the parallel translation of the switch (S1) the diode (D _a1) is conductive in the resonant tank is subjected to a voltage V _d.

Then resonance occurs continuously, and at this time, it is turned on under the zero voltage condition of the switch S1. If the resonance current falls to zero due to the continued resonance, the operation is terminated and the same operation is repeated.

The eddy current generated in the load causes the load to be heated by the induced current.

The rice cooker, which is a load, is heated by the above-described operation, and rice is cooked according to the above operation. The conventional rice cooker is as shown in FIG. 1, and rice cooked with one rice cooker.

However, in the conventional technology as described above, a rice cooker having a larger capacity can not be manufactured because the limit capacity of the rice cooker for a business is 3 kW for 25 people. In addition, a rice cooker for a hot plate type rice cooker has a problem in that the rice bread tends to deteriorate when the capacity increases.

It is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to provide a method and apparatus for driving an inverter and two or more working coils capable of heating a load by two or more loads, The present invention also provides an induction heating cooker having a plurality of loads and a method for cooking the same.

FIG. 1 is a schematic view of a conventional induction heating cooker. FIG.

FIG. 2 is a basic circuit diagram of a conventional induction heating cooker.

FIG. 3 is a configuration diagram of the induction heating cooker of the present invention. FIG.

FIG. 4 is a circuit diagram of an induction heating cooker having several loads. FIG.

FIG. 5 is an explanatory view showing an example of a cooking process when the rice cooker 1 and the rice cooker 2 are simultaneously heated in FIG.

6 shows a first embodiment of an induction heating cooker having several loads according to the present invention.

FIG. 7 shows a second embodiment of an induction heating cooker having several loads according to the present invention. FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

100: heating unit 200: switching unit

C _a1 , C _a2 , C _a3 : auxiliary capacitors C _r1 , C _r2 , C _r3 : resonant capacitor

D _a1 , D _a2 , D _a3 : auxiliary diodes L _r1 , L _r2 , L _r3 : working coils

S1, S2, S3: Switch

In order to accomplish the above object, the present invention provides a method of cooking an induction heating cooker having a plurality of loads, the method comprising the steps of: performing heating by heating to less than 10% of a maximum output; A maximum output cooking step of heating the output to a maximum output until the temperature rises to a set temperature when the heating is completed; A temperature control step of performing temperature control with an output of about 80% after completion of heating in the above process; And the steam is heated by heating to a lesser power than when it is called.

As shown in FIG. 4, the circuit configuration of the induction heating cooker having several loads according to the present invention for performing the method as described above is such that the input power is smoothed to make a direct current voltage (Vd) A filter capacitor C _f for improving the power factor of the input voltage; A heating unit 100 for heating two or more loads according to a voltage supplied from the filter capacitor C _f ; And a switching unit 200 for switching the two or more loads according to a control signal.

The heating unit 100 includes a working coil L _{r1 that} operates according to a switching operation of the switching unit 200 and that heats the first heating plate and a first heating unit L _r1 including a resonance capacitor C _r1 . (100a); And a second heating unit 100b composed of a working coil L _r2 operating with a voltage inputted in accordance with the switching operation of the switching unit 200 to heat the second heating plate and a resonant capacitor C _r2 .

The switching unit 200 switches the first to third switches S1 to S3 to serially turn on the first heating unit 100a and the second heating unit 100b according to an input control signal. make up to S3) is connected in parallel with the filter capacitor (C _f) for.

The operation and effect of the present invention will be described in detail as follows.

To operate the L _r1 for the first cooker heating place by turning on the second switch (S2) one by the resonant tank of the remaining two switches (S1 and S3) and the working coil (L _r1) and the resonant capacitor (C _r1) The first switch S1 is turned on and the remaining two switches S2 and S3 and the working coil L _r2 and the resonance capacitor C _r2 are operated in order to operate the second rice cooker L _r2 , The other half bridge is operated by the resonance tank of FIG.

When the above two half bridge operations are alternately and time-divisionally controlled, the two rice cookers can be heated at the same time.

First, the operation for heating the first rice cooker will be described as follows.

When the first switch S1 is turned off and the third switch S3 is turned on in the state where the second switch S2 is always turned on, the resonance tanks L _r1 and C _{r1 are} connected to the filter capacitor C _f A smoothed direct current voltage V _d is applied, thereby starting resonance and raising the current of the working coil L _r1 .

When the third switch S3 is turned off before the resonance half period passes, the auxiliary capacitors C _a1 and C _a3 connected in parallel to the first switch S1 and the third switch S3 are connected to the resonance tanks L _r1 and L _r2 , voltage of C _r1) and a first auxiliary capacitor (C _a1) of the switch (S1) to the secondary resonance voltage of the auxiliary capacitor (C _a3) between falling in V _d to zero the third switch (S3) is at zero V _d .

Soon after the first switch (S1) the antiparallel diode (D _a1) of the conductive resonant tank (L _{r1 r1} and C), the applied voltage is zero.

Then, resonance occurs continuously by the voltage charged in the resonance capacitor C _r1 , and at this time, the first switch S 1 is turned on under the condition of zero voltage.

The resonance current decreases due to the continuous resonance, and this time, the resonance current increases due to the resonance in the opposite direction.

When the first switch S1 is turned off before the resonance half period passes, the auxiliary capacitors C _a1 and C _a3 of the first switch S1 and the third switch S3 are connected to the resonance tanks L _r1 and C _r1 , With the resonance, the voltage of the auxiliary capacitor C _a3 drops from V _d to zero while the voltage of the auxiliary capacitor C _a1 rises from zero to V _d .

Since the third switch in anti-parallel (S3) the diode (D _a3) conducts the resonant tank is applied to a voltage (V _d).

Then, resonance occurs continuously, and at this time, the third switch S3 is turned on under the condition of zero voltage.

If the resonance current falls to zero due to the continued resonance, the operation is terminated and the same operation is repeated.

When the second switch S2 is turned off and the third switch S3 is turned on in the state where the first switch S1 is always turned on, the operation for heating the second rice cooker is performed in the resonance tanks L _r2 and C _r2 The input voltage V _d is applied and the resonance starts and the current of the working coil L _r2 rises.

When the third switch S3 is turned off after the resonance half period passes, the auxiliary capacitor C _a2 (C _a3 ) connected in parallel to the second switch S 2 and the third switch S 3 is connected to the resonance tank L _r2 C _r2) and the voltage of the voltage of the second auxiliary capacitor (C _a2) of the switch (S2) to the secondary resonance is an auxiliary capacitor (C _a3) of falling in V _d to zero therebetween, the third switch (S3) is V at zero _d .

Soon after, the third switch antiparallel diode (D _a2) of (S3) interconnecting through the resonant tank (L _r2 and _r2 C) has a zero applied voltage.

Then, resonance occurs continuously by the voltage charged in the resonance capacitor C _r2 , and the third switch S3 is turned on under the zero voltage condition.

The resonance current decreases due to the continuous resonance, and this time, the resonance current increases due to the resonance in the opposite direction.

When the third switch S3 is turned off before the resonance half period passes, the auxiliary capacitors C _a3 and C _a3 of the second switch S2 and the third switch S _{3 are} connected to the resonance tanks L _r2 and C _r2 , By resonance, the voltage of the auxiliary capacitor (C _a2 ) drops from V _d to zero while the voltage of the auxiliary capacitor (C _a3 ) rises from zero to V _d .

Since the second switch is conducting anti-parallel diode (D _a2) of (S2) is applied to the resonant tank voltage (V _d).

Then, the resonance continues, and at this time, the second switch S2 is turned on under the zero voltage condition.

If the resonance current falls to zero due to the continued resonance, the operation is terminated and the same operation is repeated.

By repeating the above operation, the two rice cookers can be heated simultaneously.

Generally, a cooked iron of a commercially available induction heating cooker occurs in the order of cooking, maximum power cooking, temperature control cooking and moxibustion.

First, it is heated to less than 10% of the maximum output, and the process is called.

After the boiling is completed in this way, when the boiling is completed, the maximum output cooking is performed by heating to the maximum output until the temperature rises to a certain set temperature.

When the maximum output cooking process as described above is completed, the temperature control cooking is performed again. In the temperature control cooking, the cooking is performed by performing the temperature control rule with the output of the maximum output of 80%.

As described above, when the maximum output cooking and the temperature control cooking are finished and the process goes to the steam cooking process, the heating process is performed by heating the cooking steam with less power at the time of cooking.

This completes the cooking process.

If the two rice cookers are used for cooking at the same time, the cooking can be performed with a slight time difference by the procedure shown in FIG. 5.

In this case, one can cook, the other can keep warm, or both can keep warm.

The method described so far only refers to the case of 50 persons for two persons with 25 servings, but can be extended to cases such as 6 and 7 with three rice cookers or four persons.

In the end, the sixth operation is the same as the above-described operation in which the switch connected in parallel with two rice cookers which are 75 servings in case of three rice cookers and not in operation.

7 shows the case where there are four rice cookers and the operation is the same as the above operation when the switches connected in parallel to the three rice cookers which are not in use are turned on.

The desired rice cooker can be expanded and used in the same manner as described above.

As described above, since the rice cooker capacity can not be extended due to the limitation of the power source, it is possible to expand the rice cooker capacity to more than 50 persons, and it is possible to operate several rice cookers by time sharing with one inverter and one control circuit. .

Claims (4)

A filter capacitor (C _f ) for smoothing the input power to output the direct-current voltage (Vd) and improving the power factor of the input voltage; A heating unit 100 for heating two or more loads according to a voltage supplied from the filter capacitor C _f ; And a switching unit (200) for heating the two or more loads by performing a switching operation according to a control signal, wherein the heating unit (100) is inputted according to a switching operation of the switching unit (200) A first heating unit 100a composed of a working coil L _r1 and a resonance capacitor C _r1 operating with a voltage to heat the first heating plate; And a second heating unit 100b composed of a working coil L _r2 for operating the second heating plate and a resonance capacitor C _r2 operated by a voltage inputted in accordance with the switching operation of the switching unit 200 The induction heating cooker has several loads. The apparatus according to claim 1, wherein the switching unit (200) switches on / off in accordance with an input control signal to control the first heating unit (100a) and the second heating unit (100b) 3 switch (S1-S3) are connected in parallel with the filter capacitor ( _Cf ). 2. The induction heating cooker according to claim 1, wherein the heating unit (100) and the switching unit (200) are further arranged in parallel so that 2N loads can be heated. A step of heating to less than 10% of the maximum output to make a call; A maximum output cooking step of heating the output to a maximum output until the temperature rises to a set temperature when the heating is completed; A temperature control cooking step of performing cooking while performing temperature control with an output of about 80% after completion of heating in the above process; And the steam is heated and heated to a lower power than when the steam is blown.