JP3671812B2 - Induction heating cooker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an induction heating cooker that performs accurate control without overheating the oil temperature even when the amount of oil is small when cooking deep-fried food.
[0002]
[Prior art]
Conventionally, in an induction heating cooker, a temperature detection means is provided in the main body, and the temperature of a pan that generates heat is indirectly measured via a plate. In the method in which temperature detection means is provided on the upper surface of the plate and the temperature is measured by bringing it into contact with the pan, the plate is not flat and the usability is deteriorated. Further, if the temperature detecting means is directly put into the oil, it causes a hygienic problem and a user's uncomfortable feeling. Accordingly, as described above, the temperature detecting means is provided in the main body portion away from the oil so as to indirectly detect the temperature of the oil.
[0003]
[Problems to be solved by the invention]
However, in the induction heating cooker, since the temperature of the pan is indirectly detected via the plate, the temperature detection means is less likely to follow as the amount of oil is smaller. Therefore, even if a flat pan is used, when heating to a target temperature with a constant power, the oil temperature is higher as the amount of oil is smaller, and the temperature is lower as the amount is higher. In the case of fried food cooking, cooking is performed by setting the oil temperature, but when the amount of oil is small, the oil temperature becomes higher than the set temperature and the fried food becomes unsatisfactory. This invention solves the subject which such a conventional induction heating cooker has, and it aims at implement | achieving the induction heating cooker which can perform fried food cooking accurately even when there is little oil amount. Another object of the present invention is to start up to the target temperature as soon as possible when the amount of oil is large and to prevent the oil temperature from rapidly rising with a small amount of oil.
[0004]
[Means for Solving the Problems]
The present invention provides a plate for placing a pan filled with oil, a heating coil for heating the pan provided under the plate, an inverter circuit for driving the heating coil, and a plate under the plate in contact with the plate The temperature detection means for measuring the temperature of the pan, the frying mode selection switch for selecting the frying mode, the oil temperature setting means for setting a set temperature which is a stable temperature of the oil, and the frying mode by the frying mode selection switch. Is selected and the target set temperature is selected by the oil temperature setting means, the temperature rise at which heating is performed by controlling the inverter circuit until the temperature Ts measured by the temperature detection means reaches the first target temperature To. And heating means for controlling the inverter circuit to keep the oil temperature at the set temperature after the oil temperature reaches the set temperature. Degree adjusting means, and the temperature raising means has first rising heating means and second rising heating means for heating at a constant power P, and the second rising heating means is configured to detect the temperature. The second target temperature Tt, ie, Tt = Ts + ΔT, which is a temperature obtained by adding the shift temperature ΔT to the temperature Ts measured by the means, is set to be lower than the first target temperature To, and the second target temperature Tt setting The difference between the temperature Ts measured by the temperature detection means and the second target temperature Tt increases as the slope of the decrease in the temperature Ts measured by the temperature detection means increases until the later delay time Δt elapses. The oil temperature is raised by heating with a larger power as the time becomes larger, and the temperature Ts and the shift temperature measured by the temperature detecting means every time the delay time Δt elapses. The second target temperature Tt is updated based on ΔT, and the oil temperature rising operation and the second target temperature Tt based on the updated second target temperature Tt during the delay time Δt set thereafter are set. The renewal operation is repeated until the temperature Ts measured by the temperature detecting means reaches the first target temperature To, and further, the heating operation by the first start-up heating means is performed, and then measured by the temperature detecting means. In order to make the difference between the Ts and the oil temperature closer, the power is turned off for a predetermined tw time that is set longer as the amount of oil is smaller, and then the induction heating cooker shifts to the heating operation by the second start-up heating means. is there.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
First aspect of the present invention, a plate put pot containing the oil, a heating coil for heating the pot provided under said plate, and an inverter circuit drive the said heating coil, under the plate a temperature detecting means for measuring the temperature of said pan is provided in contact with the plate, and fried foods mode selection switch for selecting the fry mode, and the oil temperature setting means for setting a set temperature which is the stable temperature of the oil, the frying mode When the deep-fried food mode is selected by the selection switch and the target set temperature is selected by the oil temperature setting means, the inverter circuit is controlled until the temperature Ts measured by the temperature detection means reaches the first target temperature To. and a temperature raising means for performing heating, and controls the inverter circuit so as to maintain the oil temperature at the set temperature after the oil temperature has reached the set temperature And a temperature control unit for heating, the temperature raising means, and a first raising heating means and the second start-up heating means for heating at constant power P, the second raising heating means, A second target temperature Tt that is a temperature obtained by adding a shift temperature ΔT to the temperature Ts measured by the temperature detecting means , that is, Tt = Ts + ΔT , is set to be lower than the first target temperature To , and the second target temperature To As the slope of the decrease in the temperature Ts measured by the temperature detection means increases until the delay time Δt elapses after the temperature Tt is set , or the temperature Ts measured by the temperature detection means and the second target temperature Tt and the temperature Ts of launching the oil temperature by heating in a large power as when the large temperature difference, and measured by the temperature sensing means for each of the delay time Δt course of Serial shift temperature ΔT updates the second target temperature Tt based on, subsequently set the start-up operation and the second target of the oil temperature based on the second target temperature Tt that is the update between the delay time Δt The renewal operation of the temperature Tt is repeated until the temperature Ts measured by the temperature detecting means reaches the first target temperature To, and further, the heating operation by the first rising heating means is performed, and then the temperature detection is performed. turns off the predetermined tw time power amount of oil Ru is set as small as long to approximate the measured difference of Ts and the oil temperature by means, followed induction heating cooker shifts to the heating operation by the second raising heating means to those, this temperature rise means sets a first start-up heating means tw time to turn off the power between the second raising heating means the smaller the amount of oil increased In, to achieve an induction heating cooker capable of heating to the first target temperature To better accuracy can suppress the difference between the actual oil temperature and the measured temperature Ts by the temperature detecting means as the amount of oil is small is large be able to.
[0006]
According to a second aspect of the present invention, the second start-up heating means shifts the second target temperature Tt as the difference between the temperature Ts measured by the temperature detection means and the first target temperature To increases as the delay time Δt elapses. The induction heating cooker according to claim 1 , wherein the temperature ΔT is set large and updated , and when the oil temperature is low, the temperature difference from the second target temperature Tt set by the second start-up heating means is When the oil temperature is high and the oil temperature is high, the temperature difference from the target temperature is small. Therefore, it is difficult for large power to enter and the oil temperature overshoot can be suppressed.
[0007]
According to a third aspect of the present invention, when the second start-up heating means sets the second target temperature Tt, the delay time Δt is set smaller as the difference between the temperature Ts measured by the temperature detection means and the first target temperature To increases. When the oil temperature is low, the second target temperature Tt set by the second start-up heating means is updated in a short time, and when the oil temperature is high, the induction heating cooker according to claim 1 is used. 2 Since the renewal time of the target temperature Tt becomes long and large power can be prevented from continuously entering, overshoot of the oil temperature can be suppressed.
[0008]
According to a fourth aspect of the invention, the second start-up heating means does not update the target temperature Tt when the second target temperature Tt is updated and the current target temperature Tt2 is lower than the previous target temperature Tt1. In the induction heating cooker according to Item 1, the target temperature is lowered even when the oil temperature is lowered, such as when cooking is started during heating by the second start-up heating means. Can be avoided. Further, it can be prevented that the temperature detected by the temperature detecting means decreases due to external noise or the like and the target is temporarily lowered.
[0009]
【Example】
(Example 1)
Embodiments of the present invention will be described below with reference to the drawings.
[0010]
FIG. 1 shows a block diagram of an induction heating cooker in an embodiment of the present invention. 2 is a plate on which the pan 1 is placed, 3 is a heating coil that heats the pan 1 provided under the plate 2, 4 is an inverter circuit that drives the heating coil and heats the pan 1, and 5 is a thermistor that is a temperature sensitive element. A temperature detecting means (hereinafter referred to as a sensor) for detecting the temperature of the plate 1 in contact with the plate 1 under the plate 1, a fried food mode selection switch 6a for selecting a fried food mode, and an oil temperature setting means for setting a target oil temperature 6b is a microcomputer, 12 is a microcomputer, which controls the inverter circuit 4 and controls the power supplied to the heating coil 3, and sends a signal to the control means 7 until the first target temperature is reached. Temperature riser 9 for controlling and heating, and controller 7 controls the inverter circuit to keep the oil temperature at the set temperature after the oil temperature reaches the set temperature. It has a configuration comprising a temperature control unit 11 to send the Migihitsuji signal. Further, the temperature raising means 9 includes a first raising heating means 9a and a second raising heating means 9b.
[0011]
Next, the operation of the first rising heating means 9a and the second rising heating means 9b of the temperature raising means 9 will be described with reference to FIGS. First, when the temperature of the object Ri by the fry mode is selected oil temperature setter 6b by fried foods mode selection switch 6a is selected, first raising the heating means 9a at constant power P (1450W in this embodiment) Heating is performed for a certain time (180 seconds in this embodiment). And after heating for a fixed time by the 1st starting heating means 9a, tw time power is turned off. As a result, the temperature of the sensor 5 and the actual oil temperature once opened by heating can be brought close again. The temperature setting by the temperature setting means 6b can be arbitrarily changed by the user. Further, although the first start-up heating means 9a is heated for a certain time, it may be until the temperature of the sensor 5 reaches a predetermined temperature rise from the start or until it reaches a predetermined temperature. Furthermore, the above-described conditions may be changed according to the temperature selected by the temperature setting means 6b.
[0012]
Next, the second start-up heating means 9b starts operation after power off for tw time. First, a temperature that is a shift temperature ΔT higher than the temperature Ts of the sensor 5 when the operation is started, that is, Ts + ΔT is set as the target temperature Tt, and is determined by the difference between the target temperature Tt and the temperature Ts of the sensor 5 and the inclination of the sensor 5. Heating is performed for a delay time Δt with power (the larger the temperature difference is, or the greater the temperature decrease is, the larger the power is). Then, after the lapse of Δt time, the target temperature Tt is calculated again from the temperature Ts of the sensor 5 at that time, and heating is performed for Δt time. Thereafter, this operation is repeated, and heating is performed until the final target temperature To of the temperature raising means 9 is reached. Thereby, the overshoot of the actual oil temperature when the final target temperature To is reached can be suppressed, and the oil temperature can be heated with high accuracy.
[0013]
Next, FIG. 4 shows the behavior of the oil temperature and the temperature of the sensor 5 depending on the amount of oil in the pan when heated in the same pan. As shown in FIG. 4, when the amount of oil is small, the sensor 5 cannot follow and the difference between the actual oil temperature and the temperature of the sensor 5 becomes large. Therefore, the power off time tw between the first start-up heating means 9a and the second start-up heating means 9b is changed depending on the oil amount (if the oil amount is small, tw is lengthened, and if the oil amount is large, By shortening tw), it is possible to bring the temperature of the sensor 5 closer to that of the oil regardless of the amount of oil.
[0014]
Further, as shown in FIG. 5, when the difference between the final target temperature To of the temperature raising means 9 and the temperature of the sensor 5 is large, that is, when the actual oil temperature is low and the temperature Ts of the sensor 5 is low, the aforementioned shift temperature. When ΔT is increased and the temperature of the sensor 5 approaches the final target temperature To and the temperature difference is small, the shift temperature ΔT is decreased, and when the oil temperature is low, heating is performed with high power and the target temperature Tt is approached. When heated, it can be heated with low power, and the oil temperature can be raised relatively quickly and with little overshoot.
[0015]
Similarly, as shown in FIG. 6, when the difference between the final target temperature To of the temperature raising means 9 and the temperature of the sensor 5 is large, the delay time Δt is reduced and the temperature of the sensor 5 becomes the final target temperature To. When the temperature difference approaches, the delay time Δt is increased. When the oil temperature is low, the update interval of the target temperature Tt is shortened. When the oil temperature approaches the target temperature Tt, the update time of the target temperature Tt is increased. it can. As a result, the sensor 5 can be heated with a large power when the temperature of the sensor 5 is low, and can be heated with a small power when the temperature of the sensor 5 is high, and the oil temperature can be raised relatively quickly and with little overshoot.
[0016]
Next, when cooking is started during the operation of the second start-up heating means 9b, the temperature of the sensor 5 decreases, so that the current target temperature is lower than the previous target temperature. For this reason, the oil temperature must be quickly restored with a large power, but it is heated with a small power, and cooking becomes worse. Therefore, as shown in FIG. 7, when the current target temperature is lower than the previous target temperature, by not updating the target temperature Tt, the difference between the temperature of the sensor 5 and the target temperature Tt is wide and large. Power can be entered. Further, when the temperature of the sensor 5 drops for a moment due to external noise or the like, the same is true and the power is not inadvertently lowered.
[0017]
【The invention's effect】
As described above, according to the first aspect of the present invention, the temperature rising means turns off the tw time power between the first rising heating means and the second rising heating means , and the tw time is determined as the oil amount. in Rukoto is set smaller the longer the oil amount is small enough to actually the temperature measured by the temperature sensing means oil temperature difference in temperature and measured by said temperature detecting means and can oil temperature suppressing the increase of An induction heating cooker that can be heated close to the first target temperature To with high accuracy can be realized.
[0018]
According to the invention described in claim 2, when the oil temperature is low , the temperature measured by the temperature detecting means and the temperature between the second target temperature Tt updated by the second start-up heating means every time the delay time Δt elapses. When the difference is large, large power is easily entered, and the oil temperature is high, the temperature difference from the target temperature is small, so that large power is difficult to enter and oil temperature overshoot can be suppressed.
[0019]
According to the invention described in claim 3, when the oil temperature is low, the second target temperature Tt set by the second start-up heating means is updated in a short time, and when the oil temperature is high, the second target temperature is updated. Since the update time of the temperature Tt becomes longer and it is possible to prevent large power from continuing to enter, it is possible to suppress oil temperature overshoot.
[0020]
According to the invention of claim 4 , it is avoided that the target temperature is lowered even when the oil temperature is lowered, such as when cooking is started during heating by the second start-up heating means. be able to. Further, it can be prevented that the temperature detected by the temperature detecting means decreases due to external noise or the like and the target is temporarily lowered.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an induction heating cooker according to a first embodiment of the present invention. FIG. 2 is a diagram showing an operation of a temperature raising means. FIG. 3 is a target of a second raising heating means. Fig. 4 shows the timing of temperature update. Fig. 4 shows the difference in temperature rise depending on the oil amount. Fig. 5 shows the change in shift temperature ΔT. Fig. 6 shows the change in delay time Δt. FIG. 7 is a diagram showing the target temperature Tt when the temperature is lowered.
DESCRIPTION OF SYMBOLS 1 Pan 2 Plate 3 Heating coil 4 Inverter circuit 5 Temperature detection means 6 Switch 6a Deep-fried food mode selection switch 6b Oil temperature setting means 7 Control means 9 Temperature raising means 9a First raising heating means 9b Second raising heating means

Claims (4)

A plate put oil of containing pan, a heating coil for heating the pot provided under said plate, and an inverter circuit you drive the said heating coil, provided in contact with the plate under the plate the The fried food mode is selected by the temperature detecting means for measuring the temperature of the pan , the fried food mode selecting switch for selecting the fried food mode, the oil temperature setting means for setting the set temperature which is the stable temperature of the oil, and the fried food mode selecting switch. When the target set temperature is selected by the oil temperature setting means, the temperature raising means for controlling and heating the inverter circuit until the temperature Ts measured by the temperature detection means reaches the first target temperature To. When the temperature adjustment hand performing the heating by controlling the inverter circuit so as to keep after the oil temperature has reached the set temperature the oil temperature to the set temperature With the door, the temperature raising means, and a first raising heating means and the second start-up heating means for heating at constant power P, the second raising heating means, measured by the temperature sensing means The second target temperature Tt, that is, the temperature obtained by adding the shift temperature ΔT to the measured temperature Ts , that is, Tt = Ts + ΔT , is set to be lower than the first target temperature To, and the delay time after the setting of the second target temperature Tt When the slope of the decrease in the temperature Ts measured by the temperature detecting means is large until Δt elapses , or when the temperature difference between the temperature Ts measured by the temperature detecting means and the second target temperature Tt is large. Based on the temperature Ts measured by the temperature detection means and the shift temperature ΔT every time the delay time Δt elapses, the oil temperature is raised by heating with a relatively large power. There updating the second target temperature Tt, the re-updating the updated the oil temperature raising operation and the second target temperature Tt of that based on the second target temperature Tt between the delay time Δt is set later The operation is repeated until the temperature Ts measured by the temperature detection means reaches the first target temperature To, and after the heating operation by the first start-up heating means, the Ts measured by the temperature detection means is performed. the amount of oil to approach the difference in oil temperature turns off the predetermined tw time power that will be set longer as small, then induction heating cooker shifts to the heating operation by the second raising heating means. The second start-up heating means sets the second target temperature Tt for each delay time Δt, and sets the shift temperature ΔT to be larger as the difference between the temperature Ts measured by the temperature detection means and the first target temperature To increases . The induction heating cooker according to claim 1 to be renewed .   The induction heating cooking according to claim 1, wherein when the second target temperature Tt is set, the second start-up heating means sets the delay time Δt smaller as the difference between the temperature Ts measured by the temperature detecting means and the first target temperature To increases. vessel.   The induction heating cooker according to claim 1, wherein the second start-up heating means does not update the target temperature Tt when the second target temperature Tt is updated and the current target temperature Tt2 is lower than the previous target temperature Tt1. .

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