JPH02257587A - Electromagnetic cooker - Google Patents

Abstract

PURPOSE:To easily confirm the matching state between a heating coil and an article to be heated with vision by comparing a value detected by means of an input detecting means with a value set by means of an input set means, thus indicating the compared result. CONSTITUTION:As an input set circuit 10 is operated to set an input power, the set value is outputted to an arithmetric circuit 12 and also a drive circuit is actuated according to the set value. In this case, with an iron pot of a sufficient large size mounted at the center of a top plate 21 of a cooking utensil, an input detector 13 detects an input power of an inverter circuit 4 to output the detected signal to the arithmetric circuit 12. The circuit 12 compares the value to be inputted with the value of the detected input power to output the compared result to an indicating part 14. As the matching state between a heating coil 5 and the iron pot 23 is discriminated to be proper, the indicating part 14 causes all of LED 15b, 15c,..., 15f to be lightened according to signals from the arithmetric circuit 12 and, therefore, it is possible to easily confirm visually that the matching state is optimum.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention supplies a frequency current to a heating coil, induces an eddy current in the object to be heated by the magnetic flux from the heating coil, and This invention relates to an electromagnetic cooker that heats objects using Joule heat generated by eddy currents.

(Conventional technology) An electromagnetic cooker that heats objects by electromagnetic induction is a
It has advantages such as high safety as it does not produce flames, cleanliness as the top plate on which the heated object is placed can be made of crystallized glass, and high thermal efficiency, and various electromagnetic cookers have been developed. has been done.

As such a conventional electromagnetic cooker, one shown in FIG. 8 is known.

The front operation panel of the electromagnetic cooker 1o1 has a knob 103 that can be slid laterally.

This knob 103 is connected to a variable resistor provided in the electromagnetic cooker 101, and by sliding the knob 103 to an appropriate position, input settings regarding the heating power for heating the object to be heated can be performed. I can do it. The input power value is displayed on the front operation panel. For example, if the knob 103 is slid to the 600W display position, the object to be heated placed on the top plate 105 will be heated with the heating power corresponding to the input power of 600W. , for example, to heat pots and frying pans.

Specifically, the electromagnetic cooker 101 has a built-in power supply circuit, an inverter circuit, and a heating coil, and supplies DC power obtained by rectifying and smoothing AC power to the inverter circuit. . This inverter circuit generates high frequency power according to the input set value mentioned above,
This high frequency power is supplied to the heating coil. The heating coil heats the object based on high frequency power. Therefore, when the knob 103 is moved further to the right, the object to be heated is heated with even greater heating power.

In addition, the conventional electromagnetic cooker has a built-in no-load detection means, and detects when no object to be heated is placed on the top plate 105 or when an inappropriate load such as a knife or fork is placed on the top plate 105. If it is placed on the top, it determines that there is no load and stops the heating operation.
We are trying to ensure safety.

(Problem to be Solved by the Invention) However, in the conventional electromagnetic cooker, even when the knobs 103 are set at the same position, the top plate 10
The heating power changes depending on the size, shape, and material of the object to be heated placed on the top plate, the distance between the object to be heated and the top plate, etc.

Figure 9 shows the change in input power with respect to the distance between the top plate and the bottom of the pot. Curve a is a characteristic curve using steel or magnetic stainless steel, and curve a is a characteristic curve using non-magnetic stainless steel. This is a characteristic curve when a member such as 18-8 stainless steel is used.

As is clear from FIG. 9, even when the knob 103 is set to the same state, when steel is used as the object to be heated, the input is larger than when non-magnetic stainless steel is used. You can get electricity. Also, the steel is lifted up from the top plate 105 and the top plate 10
The value of input power decreases as the distance between 5 and the bottom of the pot increases. When the value of this input power falls below a predetermined no-load level, it is determined that there is no-load state and the heating operation is stopped.

FIG. 10 is a characteristic diagram when the size of the pot placed on the top plate 105 is changed.

If the size of the pot is larger than the size of the standard steel, the value of input power will not increase much, but if the size of the pot is smaller than the size of the standard steel, the input power value will not increase much.
The value of input power decreases rapidly depending on the size of the steel placed on top.

When cooking using a small steel as described above, or when cooking by moving the frying pan or lifting the frying pan from the top plate 105 as in the case of Chinese cooking, the input power is reduced. Furthermore, if the frying pan is raised above a predetermined height, it may be determined that there is no load and the heating operation may be stopped. In this way, it is not possible to recognize changes in input power caused by lifting the frying pan during cooking, which is inconvenient.

For this reason, it has been proposed that a conventional electromagnetic cooker is provided with means for measuring input power and displays the value of the measured input power.

However, if the value input by the input setting means is small, the value of the input power actually input to the heating coil is also small, so it is important to check whether the heating coil and the object to be heated are aligned, for example, if the top plate 11 objects to be heated in the proper position! It was not possible to easily determine whether the

The present invention has been made in view of the above problems, and even when the value input and set by the input setting means is small,
The system improves usability by appropriately displaying whether the heating coil and the object to be heated are aligned, that is, changes in the heating state due to differences in the position and material of the object placed on the top plate. The purpose is to provide an electromagnetic cooker with

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides an electromagnetic cooker that includes a high-frequency power generation means that generates high-frequency power from input power, and a high-frequency power generating means that generates high-frequency power from input power. a heating means that receives high frequency power from the generating means and generates an eddy current in the heated object to heat the heated object; an input power setting means that sets the output of the heating means; and the high frequency power generating means. an input detecting means for detecting input power to the input detecting means; a comparing means for comparing the input power detected by the input detecting means with an input power preset by the input setting means; and displaying a comparison result of the comparing means. and display means.

(Function) The electromagnetic cooker according to the present invention generates high frequency power according to a value input and set in advance by the input power setting means, and inductively heats the object to be heated. Further, the input power input to the heating means at this time is detected by the input detection means, and the comparison means compares the value of the detected input power with a value preset by the input setting means. The comparison results are displayed. Thereby, the alignment state between the heating means and the object to be heated can be easily achieved.

(Example) Hereinafter, an example according to the present invention will be described in detail with reference to the drawings.

First, the configuration will be explained with reference to FIG.

AC 111 source 1 is connected to DC power supply circuit 3 via switch 2 . The DC power supply circuit 3 has four bridge-connected diodes, and rectifies the AC power.

A smoothing capacitor C1 is connected to this DC power supply circuit 3, and smoothes the power rectified by the DC power supply circuit 3. The smoothing capacitor C1 is connected to the inverter circuit 4, and smoothed DC power is supplied to the inverter circuit 4.

In the inverter circuit 4, a heating coil 5 and a resonance capacitor 6 are connected in series, and a transistor 7 is connected in parallel with the resonance capacitor 6. Further, a damper diode 8 is connected in parallel to the resonance capacitor 6. The base of the transistor 7 is connected to a drive circuit 9, and by turning on and off the transistor 9 based on a signal from the drive circuit 9, the heating coil 5 and the resonance capacitor 6 are set in a series resonance state. The electromagnetic induction effect caused by the magnetic flux generated from the heating coil 5 generates eddy currents in the object to be heated, such as steel, thereby heating the object.

The input setting circuit 10 is an input power setting means for making input settings regarding the heating object for heating the heating object,
The drive circuit 9 operates according to the value input and set by the input setting circuit 10. The input setting circuit 10 is also connected to an arithmetic circuit 12, and the value input and set by the input setting circuit 10 is output to the arithmetic circuit 12.

Further, an input detection circuit 13 is provided on the power line between the AC power supply 1 and the DC power supply circuit 3. This input detection circuit 1
For example, a current transformer is provided as 3, and outputs a detection signal having a value proportional to the input current from the AC power supply 1. The input detection circuit 13 is connected to the arithmetic circuit 12 and outputs a detection signal to the arithmetic circuit 12. The arithmetic circuit 12 compares the input setting value inputted from the input setting circuit 10 and the value of the detection signal inputted from the input detection circuit 13, and calculates the ratio thereof. In other words, the arithmetic circuit 12 is the input setting circuit 1
The value input and set by 0 is compared with the value of the detection signal which is proportional to the input power input to the heating coil 5 which is the heating means, and the ratio of both values is calculated. This determines the matching state between the heating coil 5 and the object to be heated.

The display section 14 is connected to the arithmetic circuit 12, and displays the matching state between the heating coil 5 and the object to be heated in five levels according to a signal from the arithmetic circuit 12.

Specifically, as shown in FIG. 2, the display section 14 includes an LED 15a indicating that the alignment between the heating coil 5 and the object to be heated is not good, and LEDs 15b to 115c indicating that the alignment is good. .

15d, 15e and 15f. At this time, among the plurality of LEDIs 5b, 15c, . For example, 5 LEDs15
When the lights b, 15c1 and 15r are turned on, the matching state between the heating coil 5 and the object to be heated is at level 5, which is the optimum state, that is, the input power to the inverter circuit 4 is 100% of the input setting value. Display something.

In addition, when displaying the matching state between the heating coil 5 and the object to be heated, it may be configured such that only one LED corresponding to the matching state level is lit. For example, if the configuration is such that only the LED 15f is turned on when the matching state is optimal, power consumption can be reduced.

Next, the operation of the embodiment according to the present invention will be explained.

First, operate the input setting circuit 10 to set the input power to 60, for example.
When set to 0W, this input set value is output to calculation circuit 1.
At the same time, the drive circuit 9 operates according to the input set value.

As a result, the inverter circuit 4 starts an oscillation operation, and the heating coil 5 and the resonance capacitor 6 are set in a series resonance state. The electromagnetic induction effect of the magnetic flux generated from the heating coil 5 generates eddy currents in the object to be heated, such as steel, thereby heating the object.

At this time, as shown in FIG. 3(A), a sufficiently large iron w4 is placed approximately in the center of the top plate 21 of the electromagnetic cooker.
23 is placed, the input detection circuit 13 detects the input power of the inverter circuit 4 performing the heating operation, and outputs a detection signal to the arithmetic circuit 12. Arithmetic circuit 1
2 compares and calculates the value set by the input setting circuit 10 and the value of the input power detected by the input detection circuit 13, and outputs the calculation result to the display section 14. At this time, since the detection signal from the input detection circuit 13 has a sufficient value, that is, the input power is 600 W, the arithmetic circuit 12 determines that the matching state between the heating coil 5 and the iron 123 is optimal. do. The display unit 14 displays LEDs 15b and 1 in response to the signal from the arithmetic circuit 12 as shown in FIG. 3(B).
All LEDs of 5c, . . . 15f are turned on.

This allows the cook to know that both the input setting value and the input power to the inverter circuit are 600W, and the heating coil 5 and iron WA2
It can be easily seen that the matching state between 3 and 3 is the optimal state.

Next, when the iron pot 23 is placed at a position shifted from the center point of the top plate 21 as shown in FIG. 3(C), input is made according to the positional shift as shown in FIG. As the power decreases, LEDs 15b and 15'C light up, heating coil 5 and iron fl! The consistency state with 123 is level 2.
In other words, it is displayed that the input power to the inverter circuit 4 is 40% of the input setting value.

Next, as shown in FIG. 3(E), when the steel 23 is placed at a position significantly deviated from the center point of the top plate 21, the input power further decreases and falls below the no-load level. As shown in FIG. 3(F), the LED 15a lights up to indicate that the matching state between the heating coil 5 and the iron w423 is not appropriate.

Next, when the iron pot 23 is placed again at the center point of the top plate 21 as shown in FIG. 4(A), as shown in FIG. 4(B),
As shown, LED15b, 15C1... 15f
All LEDs will light up to indicate that the alignment between the iron chain 23 and the heating coil 5 is optimal.

Next, as shown in FIG. 4(C), when a medium-sized iron 8125 having a smaller shape than the iron pan 23 is placed on the center point of the top plate 21, the display section 14 displays the iron 8125 as shown in FIG. )
As shown in , the input power decreases depending on the shape of the iron 5125, so the LEDs 15b and 15c light up to indicate that the matching state between the heating coil 5 and the steel 25 is level 2.

Next, as shown in FIG. 4(E), when an 81127 smaller than the specified size is placed on the top plate 21, the input power decreases further, and when it falls below the no-load level, the As shown in FIG. 4(F), the LED 5a lights up to indicate that the w427 placed on the top plate 21 is an inappropriate load.

Next, as shown in FIG. 5(A), place the medium-sized iron pot 25 again at the center point of the top plate 21, and as shown in FIG. 5(B), the LEDs 15b and 15C light up. This indicates that the matching state between the heating coil 5 and the steel 25 is level 2, that is, the input power to the inverter circuit 4 is 40% of the input setting value.

Next, as shown in Figure 5 (C), a medium-sized steel 2
5 is placed offset from the center point of the top plate 21, the LED 15b lights up as shown in FIG. . That is, input setting circuit 1
0 indicates that the value of the input power input to the inverter circuit 4 is 20% with respect to the input setting value set. Next, as shown in FIG. 5(E), when the 18-10 stainless steel pot 29 of sufficient size is placed on the center point of the top plate 21, the LE
D15b, 15c, and 15d light up to indicate that the matching state between the heating coil 5 and the stainless steel tA29 is level 3. That is, it is displayed that the value of the input power input to the inverter circuit 4 is 60% of the input setting value set by the input setting circuit 10.

Next, referring to FIG. 6, the effect when a sufficiently large steel 31 is moved or lifted from the top plate 21 will be explained.

When the heating coil 131 is placed on the center point of the top plate 21 as shown in FIG. 6(A), the LEDs 15b, 15C1...15f are lit and the heating coil 5 is turned on as shown in FIG. 6(B). This indicates that the alignment between the pan 31 and the pot 31 is optimal.

Next, as shown in FIG. 6(C), when the ll31 is slightly lifted off the top plate 21, as shown in FIG. 6(D), LEDI 5b, 15c.

and 15d are lit to indicate that the value of the input power to the inverter circuit 4 with respect to the input setting value is 60%.

Next, when the steel 31 is further lifted from the top plate 21 as shown in FIG. 6(E), as shown in FIG.
), only the LED 15b lights up to indicate that the value of the input power to the inverter circuit 4 is 20% of the input setting value.

Next, another embodiment of the present invention will be described with reference to FIG.

The embodiment shown in FIG. 7 is characterized in that it is constructed using a microcomputer 17 as the arithmetic circuit 12, and the value of the input setting value set by the input setting circuit 10 and the input detected by the input detection circuit 13 are The matching state between the heating coil 5 and the object to be heated can be determined with high precision by processing each power value using a digital signal and calculating the ratio of the input power input to the actual inverter circuit 4 to the input setting value. I am trying to process the calculations accordingly.

Note that the other circuit sections are the same as those shown in FIG. 1, are given the same numbers, and detailed explanations are omitted.

As described above, in the embodiment shown in FIG. 7, since the microcomputer 17 is used to perform arithmetic processing using digital signals, power consumption can be reduced.

[Efficacy of invention! If! ] As explained above, according to the present invention, the value detected by the input detection means is compared with the value input and set by the input setting means, and the comparison result is displayed. The ratio of the input power to the inverter circuit to the determined value, that is, the matching state between the heating coil and the object to be heated can be easily checked visually.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the display section of Fig. 1, and Fig. 3 shows a sufficiently large pot placed on the top plate. Fig. 4 is an explanatory drawing showing an example of the display when steels of different sizes are placed approximately at the center of the top plate. An explanatory diagram showing an example of the display when a medium-sized iron chain and stainless steel are placed, Fig. 6 is an explanatory diagram showing an example of the display when the steel is lifted from the top plate, and Fig. 7 is an explanatory diagram showing an example of the display when a medium-sized iron chain and stainless steel are placed. FIG. 8 is a perspective view showing a conventional example; FIG. 9 is a characteristic diagram showing the value of input power with respect to the distance between the top plate and the bottom of the pot; FIG. FIG. 10 is a characteristic diagram showing the value of input power with respect to the size of steel. 4...Inverter circuit 5...Heating circuit 10...Input setting circuit 12...Arithmetic circuit 13...Input detection circuit 14...Display section Fig. 4 (A) -l') 4th Figure (C) Figure 4 CB) Figure 4 (D)

Claims (1)

[Claims] A high-frequency power generation means for generating high-frequency power from input power; and a high-frequency power generation means that generates an eddy current in a heated object by receiving the high-frequency power from the high-frequency power generating means to heat the heated object. heating means for heating; input power setting means for setting the output of the heating means; input detection means for detecting the input power to the high frequency power generation means; and the input power detected by the input detection means and the input power. An electromagnetic cooking device characterized by having a comparison means for comparing the input power set in advance by the power setting means, and a display means for displaying the comparison result of the comparison means.