JP6983058B2 - Induction heating cooker - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention is an induction heating cooker that heats a cooking container placed on the upper surface of the top plate by electromagnetic induction, and in particular, induction heating cooking provided with a pot bottom temperature sensor that detects the temperature of the cooking container on the lower surface of the top plate. Regarding the vessel.

Conventionally, in an induction heating cooker equipped with a heating coil that heats a cooking container such as a pot or a frying pan placed on the upper surface of the top plate by electromagnetic induction, a pot bottom temperature sensor is provided on the lower surface of the top plate for cooking. It is known that the amount of warpage of the bottom of the container is determined based on the detection temperature of the pot bottom temperature sensor, and the output of the heating coil is controlled according to the amount of warpage (for example, Patent Document). 1).

Japanese Unexamined Patent Publication No. 2012-178273

In this type of induction heating cooker, ceramic glass having high heat resistance and impact resistance is widely used for the top plate so that the induction heating performance of the cooking container by the heating coil is not impaired and sufficient durability can be obtained. There is. However, on the other hand, the thermal conductivity from the cooking container to the pot bottom temperature sensor is low, and the actual temperature state of the object to be heated in the cooking container cannot be detected accurately and in a timely manner. In particular, when the amount of warp at the bottom of the container is large, the temperature of the cooking container is not sufficiently transmitted to the pot bottom temperature sensor even though the cooking container itself is normally heated by electromagnetic induction, and the actual object to be heated is actually heated. The error between the temperature state and the temperature detected by the pot bottom temperature sensor becomes larger. Therefore, in the above-mentioned conventional induction heating cooker, when it is determined that the amount of warpage of the bottom of the container is large, the output of the heating coil is limited to prevent overheating of the object to be heated such as oil.

However, in boiling water where it is not necessary to consider overheating of the object to be heated, if the output of the heating coil is limited during cooking as in the conventional induction heating cooker, the temperature of the object to be heated is increased by that amount. Since the time to reach the temperature becomes redundant, there is a problem that the user feels inconvenience when he / she wants to complete the boiling at an early stage.

The present invention has been made in view of the above problems, and an object of the present invention is to improve usability at the time of boiling in an induction heating cooker that heats a cooking container placed on the upper surface of a top plate by electromagnetic induction. There is something in it.

The present invention includes a heating coil that heats a cooking container placed on the upper surface of the top plate of the instrument body by electromagnetic induction, and a pot bottom temperature sensor provided on the lower surface of the top plate to detect the temperature of the bottom of the container of the cooking container. , An inductive heating cooker equipped with an operation control unit that controls the output of the heating coil and measures the cooking time. The operation control unit is a pan bottom temperature sensor after the heating of the cooking container is started as a boiling operation. The amount of warpage of the bottom of the container is determined based on the degree of change in the detected temperature, the boiling time corresponding to the amount of warping is set as the cooking time, and after the heating of the cooking container is started, the boiling time is started from a predetermined time point. until after maintaining the output of the heating coil at a predetermined setting output, have rows predetermined cooking end process at the time the kettle time has elapsed, the warp amount determination operation, the change in the first period during the heating of the cooking container The first warp amount determination operation for detecting the degree and determining that the smaller the degree of change in the first period is, the larger the warp amount at the bottom of the container is, and the second period after the first period during heating of the cooking container. The second warp amount determination operation for detecting the degree of change and determining that the smaller the degree of change in the second period is, the larger the warp amount at the bottom of the container is executed, and the first warp amount determination operation and the second warp amount are executed, respectively. It is characterized in that the amount of warpage of the bottom of the container is determined based on the determination result of the determination operation.

In this case, in the water boiling operation, the output of the heating coil is maintained at the set output without being changed from a predetermined time point until the water boiling time elapses. Therefore, during that time, the cooking container is continuously heated at a high temperature. Can be done. Therefore, even if the amount of warpage of the bottom of the container is large, the time until the object to be heated reaches the target temperature does not become redundant.

In this case, not only the degree of change in the temperature detected by the pot bottom temperature sensor in the first period during heating of the cooking container, but also the degree of change in the first period and the degree of change in the second period thereafter are used to determine the bottom of the container. Since the amount of warpage is determined, the accuracy of the warpage determination is high, and a more appropriate boiling time is set. Therefore, it is possible to reliably prevent the object to be heated from being continuously heated more than necessary or being insufficiently heated.

Preferably, in the induction heating cooker, when it is determined that the warp amount is smaller than the reference in at least one of the first warp amount determination operation and the second warp amount determination operation, it is further after the second period. In the third period of the above, the calculation temperature rise time required for the detection temperature to rise from the predetermined calculation start temperature to the calculation end temperature is detected, and the boiling time is calculated using the calculation temperature rise time.

In this case, when it is determined that the warp amount at the bottom of the container is smaller than the standard in at least one of the first warp amount determination operation and the second warp amount determination operation, the actual temperature state of the object to be heated and the pot bottom temperature. Assuming that the error from the detection temperature of the sensor is small, it is necessary for the detection temperature of the pot bottom temperature sensor to rise from the calculation start temperature to the calculation end temperature in the third period, which is closer to the boiling temperature after the second period. The time (calculation temperature rise time), that is, the degree of increase in the temperature of the object to be heated is detected, and the boiling time is determined according to the degree of increase. As a result, the cooking end process can be performed more accurately according to the actual temperature state of the object to be heated.

Preferably, in the induction heating cooker, if it is not determined in any of the first warp amount determination operation and the second warp amount determination operation that the warp amount is smaller than the reference, the second warp amount determination operation is performed. The water boiling time is calculated using the determination temperature rise time required for the detected temperature to rise from the predetermined determination start temperature to the determination end temperature, which is detected as the degree of change in the second period.

When it is not determined that the warp amount at the bottom of the container is smaller than the standard in either the first warp amount determination operation or the second warp amount determination operation, that is, when it is determined that the warp amount is equal to or more than the standard, that time point. Already, the actual temperature of the object to be heated may be close to the boiling temperature. Therefore, in the present invention, when it is determined that the amount of warpage is equal to or greater than the standard as described above, it depends on the determination temperature rise time detected to determine the amount of warpage of the bottom of the container in the second period. Determine the boiling time. Therefore, the cooking end process can be performed earlier than the case where the degree of increase in the temperature of the object to be heated is newly detected after the determination of the amount of warpage is completed and the boiling time is calculated based on the degree of increase.

As described above, according to the present invention, the water boiling operation can be completed at an early stage regardless of the amount of warpage of the bottom of the container, so that the usability at the time of boiling is improved.

FIG. 1 is a schematic configuration diagram of an induction heating cooker according to an embodiment of the present invention. FIG. 2 is a flowchart showing a main control operation of a water heater operation in the induction heating cooker according to the embodiment of the present invention. FIG. 3 is a flowchart showing a first warp amount determination operation of the bottom of the container in the induction heating cooker according to the embodiment of the present invention. FIG. 4 is a flowchart showing a second warp amount determination operation of the bottom of the container in the induction heating cooker according to the embodiment of the present invention. FIG. 5 is a data table showing constants for calculating the first boiling time in the induction heating cooker according to the embodiment of the present invention. FIG. 6 is a data table showing constants for calculating the second boiling time in the induction heating cooker according to the embodiment of the present invention.

Next, the above-described embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the induction heating cooker 1 according to the embodiment of the present invention is a so-called built-in type IH stove that is mounted in a dropped state in a mounting port 50 provided in a counter top 5 of a kitchen. On the lower surface side of the top plate 11 constituting the upper surface of the instrument main body 10, one or a plurality of heating coils 21 for heating a cooking container P such as a pot or a kettle placed at a predetermined position on the top plate top surface 11A by electromagnetic induction. Is provided. In this specification, the front surface 13 of the instrument body 10 arranged facing the front side of the counter top 5 is the front surface of the induction heating cooker 1, and the depth direction when the instrument body 10 is viewed from the front side is defined. The front-back direction and width direction are called the left-right direction, and the height direction is called the up-down direction.

The heating coil 21 is connected to a power supply circuit (not shown) incorporated in the main control circuit 100 through electrical wiring, and is placed above the heating coil 21 by supplying a predetermined high output power from the power supply circuit. Electromagnetic induction is generated in the cooked container P.

In the space provided in the center of the heating coil 21 on the lower surface side of the top plate 11, the pot bottom temperature for detecting the temperature of the bottom of the cooking container P (hereinafter referred to as “container bottom”) P1 heated by the heating coil 21. A sensor 22 is provided. The pot bottom temperature sensor 22 may be provided on the side of the heating coil 21 as long as the temperature of the container bottom P1 can be appropriately detected.

The top plate 11 is made of ceramic glass having high heat resistance and impact resistance, and the cooking container P is directly placed on the upper surface of the top plate 11A at a position facing upward of the heating coil 21. The pot bottom temperature sensor 22 is provided in contact with the bottom surface 11B of the top plate, and detects the temperature transmitted from the cooking container P via the top plate 11. If the temperature of the bottom P1 of the container can be appropriately detected, the pot bottom temperature sensor 22 may be provided in a state where it is not in contact with the bottom surface 11B of the top plate.

In front of the top plate 11, there is a power switch (not shown) for operating the on / off of the main power supply of the induction heating cooker 1, a coil operation switch 23 for operating the output of the heating coil 21, and a heating coil 21. An operation panel 14 including a setting operation switch 24 for setting and operating the cooking conditions of the object F to be heated, an information display unit 25 for displaying information such as the output state of the heating coil 21 and the cooking conditions is provided. Further, inside the instrument main body 10, an audio output unit 26 for outputting information such as the output state of the heating coil 21 and the cooking conditions by voice is provided. The audio output unit 26 may output each of the above information as a buzzer sound.

Although not shown, on the operation panel 14, as a setting operation switch 24, a cooking mode setting switch for selecting and setting one cooking mode from a plurality of cooking modes such as boiling water, simmered food, fried food, and rice cooking, and a cooking time are manually set. It is equipped with a timer setting switch for setting, a temperature setting switch for manually setting the heating temperature, and the like, and various cooking conditions of the object F to be heated can be set and input by using each of these setting operation switches 24.

Inside the instrument body 10, a main control circuit 100 is incorporated as an operation control unit that controls the operation of the entire induction heating cooker 1 such as output control of the heating coil 21 and measurement of cooking time. The power switch, coil operation switch 23, setting operation switch 24, information display unit 25, audio output unit 26, heating coil 21, pot bottom temperature sensor 22, and other electrical components are all connected to the main control circuit 100 through electrical wiring. ing. The power supply circuit of the main control circuit 100 is connected to an external power supply (not shown), and the drive power of each of the electrical components is supplied from the external power supply through the power supply circuit.

The main control circuit 100 includes a power supply control unit that turns on and off the main power of the inductive cooking cooker 1 according to an on / off operation of the power switch, a heating control unit that controls the output of the heating coil 21, an information display unit 25, and an audio output unit 26. Information output control unit that controls the output of, cooking time setting unit that sets the cooking time of the selected cooking mode, time measuring unit that measures the cooking mode or manually set cooking time, predetermined according to the above cooking time A cooking control unit that performs cooking end processing, a warp amount determination unit that determines the amount of warpage of the container bottom P1 based on the degree of change in the detection temperature (hereinafter referred to as "pot bottom detection temperature") T1 of the pot bottom temperature sensor 22, and a pot bottom detection temperature. It has a circuit configuration such as a water heater mode limiting unit that prohibits the setting of a water heater cooking mode (water heater mode) when T1 is equal to or higher than a predetermined limit temperature Ts.

When the boiling mode is selected and set, the cooking control unit sets the boiling times H1 and H2 corresponding to the warp amount as the cooking time, and performs a predetermined cooking end process when the boiling times H1 and H2 have elapsed. It has an execution unit for boiling water.

The warp amount determination unit has a temperature rise value monitoring unit that monitors the temperature rise value ΔT of the pot bottom detection temperature T1 per predetermined time during heating of the cooking container P, and a pot bottom detection temperature T1 that monitors the pot bottom detection temperature T1 during heating of the cooking container P. The determination temperature rise time monitoring unit that monitors the determination temperature rise time ΔS1 required to rise from the determination start temperature Ta to the determination end temperature Tb, and the smaller the temperature rise value ΔT, the larger the amount of warpage of the container bottom P1. It has a first warp amount determination operation execution unit for determining that, and a second warp amount determination operation execution unit for determining that the longer the determination temperature rise time ΔS1 is, the larger the warp amount of the container bottom P1 is. ..

The cooking time setting unit has a start temperature setting unit that selects a water boiling start temperature T2 corresponding to the pot bottom detection temperature T1 at the time when the heating coil 21 is turned on from a plurality of reference temperatures, and water boiling times H1 and H2. A constant selection unit that selects constants A1, B1, A2, and B2 for calculation according to the boiling start temperature T2, the judgment result of the first warp amount determination operation, and the judgment result of the second warp amount determination operation, and cooking. The calculation temperature rise time monitoring unit for monitoring the calculation temperature rise time ΔS2 required for the pot bottom detection temperature T1 to rise from the predetermined calculation start temperature Tc to the calculation end temperature Td while the container P is being heated, and the above constant A1. , B1 and the first water heater time calculation unit for calculating the water heater time H1 using the calculation temperature rise time ΔS2, and the second water heater time H2 for calculating the water heater time H2 using the above constants A2 and B2 and the determination temperature temperature rise time ΔS1. It has a boiling time calculation unit.

The control operation during the water boiling operation by the induction heating cooker 1 will be described with reference to the flowcharts of FIGS. 2 to 4.

As shown in FIG. 2, when the main power of the induction cooker 1 is turned on, the pot bottom detection temperature T1 is not less than the limit temperature Ts (here, 50 ° C.), that is, the bottom of the container P1. If the temperature is already above the limit temperature Ts (No in the step of ST1), the temperature of the bottom P1 of the container is less than the limit temperature Ts and the degree of temperature rise after that is different, so the boiling operation is started from this state. However, there is a possibility that the boiling of the object to be heated F cannot be detected accurately and in a timely manner. Therefore, in this case, the reception of the water boiling mode selection operation by the setting operation switch 24 is rejected (ST2).

On the other hand, if the pot bottom detection temperature T1 is less than the limit temperature Ts (Yes in the step of ST1) when the main power of the induction heating cooker 1 is turned on, the setting of the boiling mode is permitted (ST3). .. Then, when the water boiling mode is selected by the operation of the setting operation switch 24 and the heating coil 21 is turned on by the corresponding coil operation switch 23 (Yes in the step of ST4), the output of the heating coil 21 is the water boiling mode. While maintaining the predetermined high output set in, the elapsed time from the time when the above-mentioned on operation is performed and the heating of the cooking container P is started, that is, the measurement of the cooking time is started, and the pot bottom is detected at that time. The boiling start temperature T2 corresponding to the temperature T1 is set (ST5).

Specifically, for example, if the pot bottom detection temperature T1 at the time when the on operation is performed is "8 ° C", the boiling start temperature T2 is set to "10 ° C" and the pot bottom detection at the time when the on operation is performed is performed. If the temperature T1 is "12 ° C", the boiling start temperature T2 is set to "20 ° C", and if the pot bottom detection temperature T1 at the time when the above on operation is performed is "25 ° C", the boiling start temperature T2 is It is set to "30 ° C". That is, the water boiling start temperature T2 is set to a value obtained by raising the ones digit of the pot bottom detection temperature T1 at the time when the on operation is performed.

After executing the step of ST5, the first warp amount determination operation and the second warp amount determination operation are performed (ST6). More specifically, as shown in FIG. 3, in the first warp amount determination operation, first, it is monitored whether or not the pot bottom detection temperature T1 reaches the water boiling start temperature T2 set as described above (ST611). Then, when the pot bottom detection temperature T1 reaches the boiling start temperature T2 (Yes in the step of ST611), it is monitored that a predetermined time (here, 60 seconds) elapses from that point (ST612). Even during the first warp amount determination operation, the output of the heating coil 21 is maintained at a high output without being changed.

If the predetermined time elapses after the pot bottom detection temperature T1 reaches the boiling start temperature T2 (Yes in the step of ST612), the value obtained by subtracting the boiling start temperature T2 from the pot bottom detection temperature T1 at that time, that is, the predetermined time. The temperature rise value ΔT of the pot bottom detection temperature T1 is detected, and the first warp amount of the container bottom P1 is determined based on the magnitude of the temperature rise value ΔT (ST613 to ST615).

Specifically, if the temperature rise value ΔT is larger than the first reference rise value D1 (here, 20 deg) and the second reference rise value D2 (here, 30 deg) (Yes in the step of ST614). , Yes in the step of ST615), the first warp amount is determined to be "small" (ST616), and if the temperature rise value ΔT is larger than the first reference rise value D1 but is equal to or less than the second reference rise value D2. (Yes in the step of ST614, No in the step of ST615), the first warp amount is determined to be "medium" (ST617), and if the temperature rise value ΔT is equal to or less than the second reference rise value D2 (in the step of ST614). No), the first warp amount is determined to be "large" (ST618).

As shown in FIG. 4, in the second warp amount determination operation, first, it is monitored whether or not the pot bottom detection temperature T1 has reached the determination start temperature Ta (here, 40 ° C.) (ST621). Then, when the pot bottom detection temperature T1 reaches the determination start temperature Ta (Yes in the step of ST621), the measurement of the elapsed time from that point is started, and the pot bottom detection temperature T1 is the determination end temperature Tb (here, 60 ° C.). ) Is monitored (ST622-ST623). Even during the second warp amount determination operation, the output of the heating coil 21 is maintained at a high output without being changed.

If the pot bottom detection temperature T1 reaches the judgment end temperature Tb from the judgment start temperature Ta (Yes in the step of ST623), the elapsed time at that time, that is, the pot bottom detection temperature T1 rises from the judgment start temperature Ta to the judgment end temperature Tb. The second warp amount of the container bottom P1 is determined based on the length of the determination temperature rise time ΔS1 required for the determination (ST624 to ST625).

Specifically, if the determination temperature rise time ΔS1 is equal to or less than the first reference rise time E1 (here, 40 seconds) (No in the step of ST624), the second warp amount is determined to be “small” (No). ST626), if the determination temperature rise time ΔS1 is longer than the first reference rise time E1 but is equal to or less than the second reference rise time E2 (here, 60 seconds) (Yes in the step of ST624, in the step of ST625). No), if the second warp amount is determined to be "medium" (ST627) and the determination temperature rise time ΔS1 is longer than the first reference rise time E1 and the second reference rise time E2 (ST624). Yes in the step, Yes in the step of ST625), and the second warp amount is determined to be "large" (ST628).

As shown in FIG. 2, the determination result of the first warp amount determination operation performed in the step of ST6 (hereinafter referred to as "first warp determination") or the determination result of the second warp amount determination operation (hereinafter, "second"). If at least one of (referred to as "warp determination") is "small" (Yes in the step of ST7 or ST8), the pot bottom detection temperature T1 is further set as a parameter corresponding to the capacity (water amount) of the object to be heated F. The calculation temperature rise time ΔS2 required from the calculation start temperature Tc to the calculation end temperature Td is detected. Specifically, as in the steps from ST621 to ST623, if the pot bottom detection temperature T1 reaches the calculation start temperature Tc (here, 60 ° C.) (Yes in the step of ST9), the elapsed time from that point is measured. Is started, and further, it is monitored that the pot bottom detection temperature T1 reaches the calculation end temperature Td (here, 85 ° C.) (ST10 to ST11).

When the pot bottom detection temperature T1 reaches the second temperature Td (Yes in the step of ST11), the elapsed time at that time, that is, the pot bottom detection temperature T1 is required to rise from the calculation start temperature Tc to the calculation end temperature Td. Using the calculation temperature rise time ΔS2 and the constants A1 and B1 corresponding to the boiling start temperature T2, the boiling time (hereinafter referred to as “first boiling time”) H1 when the warp amount is “small” is defined as follows. It is calculated by the formula (1) of (ST12).

H1 = A1 × ΔS2 + B1 ・ ・ ・ (1)

The constants A1 and B1 when at least one of the warpage determinations is "small" are the calculation temperature rise time ΔS2 and the boiling time measured on a trial basis using the cooking container P having the minimum warp amount. It is preset based on a plurality of sample data showing the relationship between the above (see FIG. 5). Further, the first warp amount determination operation and the second warp amount determination operation are performed in parallel at the same time, and when the warp determination is set to "small" in any one of them, the other warp amount determination operation is determined. The step of ST11 is executed without waiting for the result.

After that, when the cooking time reaches the first boiling time H1 (Yes in the step of ST13), the output of the heating coil 21 is limited to a predetermined low output (here, the minimum output) as a cooking end process, and information is displayed. The unit 25 and the voice output unit 26 notify that the object F to be heated has reached a boiling state, that is, that the boiling has been completed, and the boiling operation is terminated (ST14).

On the other hand, if neither the first warp determination nor the second warp determination is "small" in the step of ST6, that is, if it is "medium" or "large" (No, in the step of ST7). No) in the step of ST8, the water boiling time when the amount of warpage is not "small" using the determination temperature rise time ΔS1 used for the second warp determination and the constants A2 and B2 corresponding to the water boiling start temperature T2. H2 (hereinafter referred to as "second boiling time") is calculated by the following formula (2) (ST15).

H2 = A2 × ΔS1 + B2 ・ ・ ・ (2)

The constants A2 and B2 when none of the warp determinations were set to "small" are the determination temperature rise time ΔS1 and the boiling time measured on a trial basis using a plurality of types of cooking containers P having different warpage amounts. It is preset based on a plurality of sample data showing the relationship between the above (see FIG. 6).

After that, when the cooking time reaches the second boiling time H2 (Yes in the step of ST16), the output of the heating coil 21 is adjusted to a low output (here, the lowest output) as the cooking end process, and the information display unit 25 is used. And the voice output unit 26 notifies that the object F to be heated is in a boiling state, that is, that the boiling is completed, and the boiling operation is terminated (ST14).

As described above, according to the induction heating cooker 1, the output of the heating coil 21 is changed until the boiling times H1 and H2 elapse, even while the amount of warpage of the container bottom P1 is determined in the boiling operation. Since it is maintained at the set output (high output), the cooking container P can be continuously heated at a high temperature during that time. Therefore, regardless of the amount of warpage of the bottom P1 of the container, the time until the object F to be heated reaches the target temperature does not become redundant, and the water boiling operation can be completed at an early stage. Therefore, usability is improved.

Moreover, in this case, when the boiling operation is started, the boiling times H1 and H2 corresponding to the amount of warpage of the bottom P1 of the container are set, and when the boiling times H1 and H2 have elapsed, the cooking end process is performed (here, the cooking end process is performed). The output of the heating coil 21 is limited to a low output, and the information display unit 25 and the voice output unit 26 notify the completion of boiling), so that the object F to be heated continues to be heated more than necessary, or the heating becomes insufficient. It can also be prevented. Therefore, the usability is further improved.

Further, in this case, the magnitude of the temperature rise value ΔT of the pot bottom detection temperature T1 after the output start of the heating coil 21 or the judgment required for the pot bottom detection temperature T1 to rise from the judgment start temperature Ta to the judgment end temperature Tb. Since the amount of warpage of the bottom P1 of the container is determined not only by either the length of the temperature rise time ΔS1 but also by both the temperature rise value ΔT and the determination temperature rise time ΔS1, the accuracy of the warp determination is high and more appropriate. The boiling time H1 and H2 are set. Therefore, it is possible to more reliably prevent the object F to be heated from being continuously heated more than necessary or being insufficiently heated, and the usability is further improved.

Further, in this case, when the warp amount of the container bottom P1 is determined to be "small" in at least one of the first warp amount determination operation and the second warp amount determination operation, the actual temperature of the object F to be heated is determined. Assuming that the error between the state and the pot bottom detection temperature T1 is small, the calculation temperature rise time ΔS2 required for the pot bottom detection temperature T1 to rise from the calculation start temperature Tc to the calculation end temperature Td closer to the boiling temperature, that is, , The degree of temperature rise of the object F to be heated is detected, and the first boiling time H1 is determined according to the degree of temperature rise. Therefore, the cooking end process can be performed more accurately according to the actual temperature state of the object F to be heated. It can be carried out.

On the other hand, if the warp amount of the container bottom P1 is not determined to be "small" in either the first warp amount determination operation or the second warp amount determination operation, the actual temperature state of the object F to be heated and the pot bottom detection temperature. Assuming that the error from T1 is large, the second water boiling time H2 is set according to the determination temperature rise time ΔS1 detected for determining the warp amount of the container bottom P1 in the second warp amount determination operation. Since it is determined, the cooking end process is performed earlier than the case where the degree of increase in the temperature of the object to be heated F is newly detected after the determination of the amount of warpage is completed and the second boiling time H2 is calculated based on the degree of increase. It can be performed.

In the above embodiment, as the cooking end process, the output of the heating coil 21 is limited to a low output, and the information display unit 25 and the voice output unit 26 notify the user of the completion of boiling, and the heating coil 21 is notified to the user. Although the configuration for prompting the output stop operation of the above is described, the output of the heating coil 21 may be automatically stopped, and the information display unit 25 and the audio output unit 26 may notify the completion of boiling water. The output of the heating coil 21 may not be limited, and only the notification of the completion of boiling water may be notified from the information display unit 25 and the voice output unit 26.

Further, in the above embodiment, as a parameter corresponding to the capacity of the object to be heated F, the calculation temperature rise time ΔS2 required for the pot bottom detection temperature T1 to rise from the calculation start temperature Tc to the calculation end temperature Td is detected. As described above, the temperature rise value ΔTp is detected every unit time (for example, every 5 seconds) after the pot bottom detection temperature T1 reaches the calculation start temperature Tc, and the above is within a predetermined time (for example, 25 seconds). Of the temperature rise values ΔTp, the sum of the other temperature rise values ΔTp excluding the maximum value and the minimum value may be used as a parameter corresponding to the capacity of the object to be heated F.

Further, in the above embodiment, the output of the heating coil 21 is set and output from the time when the heating coil 21 is turned on, that is, the time when the heating of the cooking container P is started until the boiling times H1 and H2 elapse. However, after the heating coil 21 is turned on, a predetermined time has elapsed (for example, when the pot bottom detection temperature T1 reaches the boiling start temperature T2). It may be configured to maintain the output of the heating coil 21 at the set output until the time H1 and H2 elapse.

Further, in the above embodiment, the elapsed time from the time when the heating coil 21 is turned on is monitored as the cooking time, and when the cooking time reaches the boiling times H1 and H2, a predetermined cooking end process is executed. However, the elapsed time from the time when a predetermined time elapses after the heating coil 21 is turned on (for example, when the pot bottom detection temperature T1 reaches the boiling start temperature T2) is shown. It may be monitored as a cooking time, and if the cooking time reaches the boiling times H1 and H2, it may be configured to execute a predetermined cooking end process.

Further, in the above embodiment, the first warp amount determination operation and the second warp amount determination operation are performed in parallel at the same time, and when the warp determination is set to "small" in any one of them, the other warp amount is determined. Although the first boiling time H1 is calculated without waiting for the judgment result of the judgment operation, as the first warp amount judgment operation, the pot bottom detection temperature T1 in the first period during heating of the cooking container is described. After making the first warp determination based on the degree of change in the above, as the second warp amount determination operation, the second warp determination is made based on the degree of change in the pot bottom detection temperature T1 in the second period after the first period. It may be configured to calculate the first boiling time H1 when the warp determination of at least one of them is set to "small".

More specifically, in the step of ST6 shown in FIG. 2, first, as the degree of change of the pot bottom detection temperature T1 in the first period, a predetermined time after the pot bottom detection temperature T1 reaches the water boiling start temperature T2 set as described above. The temperature rise value ΔT until (for example, 60 seconds) elapses is detected. Alternatively, the temperature rise time ΔS is detected based on the elapsed time required for the pot bottom detection temperature T1 to reach a predetermined temperature (for example, 40 ° C. lower than the limit temperature Ts) after reaching the boiling start temperature T2. As a result, if the temperature rise value ΔT is large (or if the temperature rise time ΔS is short), it is determined that the first warp amount is small, and if the temperature rise value ΔT is small (or if the temperature rise time ΔS is long), the first warp is determined. It is determined that the amount is large (first warp amount determination operation).

Next, as the degree of change of the pot bottom detection temperature T1 in the second period after the end of the first period, after the pot bottom detection temperature T1 reaches the determination start temperature Ta (for example, 40 ° C.), the determination end temperature Tb (for example, for example) is further reached. , 60 ° C.), and the temperature rise time ΔS1 for determination is detected based on the elapsed time required for the temperature to rise to 60 ° C.). As a result, if the determination temperature rise time ΔS1 is short, it is determined that the first warp amount is small, and if the temperature rise value ΔT is long, it is determined that the first warp amount is large (second warp amount determination operation).

When at least one of the determination results of the first warp amount determination operation or the second warp amount determination operation is "small", the pot bottom detection temperature in the third period after the second period ends. As the degree of change in T1, the temperature rise time ΔS2 for calculation required for the pot bottom detection temperature T1 to reach the calculation start temperature Tc (for example, 60 ° C.) and then further rise to the calculation end temperature Td (for example, 85 ° C.) is set. It is detected, and the first boiling time H1 is calculated in the same manner as in the above embodiment.

On the other hand, if neither of the determination results of the first warp amount determination operation and the second warp amount determination operation is "small", the pot bottom detection temperature T1 in the second period is first in the second warp amount determination operation. Using the determination temperature rise time ΔS1 detected when determining the degree of change, the second water boiling time H2 is calculated in the same manner as in the above embodiment.

In this way, the degree of change in the pot bottom detection temperature T1 during the first period (here, a predetermined time from the boiling start temperature T2 or from the boiling start temperature T2 to 40 ° C.), which is the initial stage of heating, and the second after that. Since the amount of warpage of the container bottom P1 is determined by both the degree of change in the pot bottom detection temperature T1 during the period (here, from 40 ° C. to 60 ° C.), the amount of warpage can be determined more accurately as in the above embodiment. .. Therefore, it is possible to reliably prevent the object F to be heated from being continuously heated more than necessary or being insufficiently heated.

Further, when the warp amount of the container bottom P1 is determined to be "small" in at least one of the first warp amount determination operation and the second warp amount determination operation, the boiling temperature is closer to the boiling temperature after the second period. Since the degree of change in the pot bottom detection temperature T1 for three periods (here, from 60 ° C. to 85 ° C.) is detected and the first boiling time H1 is determined according to the degree of change, the subject is covered in the same manner as in the above embodiment. The cooking end process can be performed more accurately according to the actual temperature state of the heated material F.

On the other hand, if the warp amount of the container bottom P1 is not determined to be "small" in either the first warp amount determination operation or the second warp amount determination operation, the actual temperature of the object to be heated F is already set at that time. Since it may be close to the boiling temperature, the amount of warpage of the container bottom P1 is first determined in the second period without detecting the degree of change in the pot bottom detection temperature T1 for newly calculating the second boiling time H2. The second boiling time H2 is determined according to the determination temperature rise time ΔS1 detected in. Therefore, as in the above embodiment, the cooking end process can be performed at an early stage.

INDUSTRIAL APPLICABILITY The present invention is particularly useful in an induction heating cooker for general households in which the amount of boiling water is relatively small (for example, 1 liter to 2 liters). If the amount of boiling water is as described above, a sufficient temperature change can be detected even if the amount of water is different, so that the amount of warpage can be accurately determined.

Further, the present invention is not limited to the built-in stove used by being embedded in the countertop 5 of the kitchen, the table stove used by placing it on the table of the kitchen, or a small size that can be carried to a desired place and used. It can also be applied to a tabletop stove.

1 Induction heating cooker 10 Instrument body 100 Main control circuit 11 Top plate 21 Heating coil 22 Pot bottom temperature sensor P Cooking container P1 Container bottom

Claims (3)

A heating coil that heats the cooking container placed on the upper surface of the top plate of the instrument body by electromagnetic induction, a pot bottom temperature sensor that is provided on the lower surface of the top plate and detects the temperature of the bottom of the cooking container, and a heating coil. It is an induction heating cooker equipped with an operation control unit that controls output and measures cooking time.
The motion control unit
As a boiling operation, the amount of warpage of the bottom of the container is determined based on the degree of change in the detection temperature of the pot bottom temperature sensor after the heating of the cooking container is started, and the boiling time corresponding to the amount of warpage is set as the cooking time. after heating of the cooking container is started, the output of the heating coil from a predetermined time point until the lapse of kettle time maintained at a predetermined set output, have rows predetermined cooking end process at the time the kettle time has elapsed,
As a warp amount determination operation, a first warp amount determination operation is performed in which the degree of change in the first period during heating of the cooking container is detected, and the smaller the degree of change in the first period, the larger the amount of warp at the bottom of the container. A second warp amount determination operation that detects the degree of change in the second period after the first period during heating of the cooking container, and determines that the smaller the degree of change in the second period, the larger the amount of warpage at the bottom of the container. The induction cooking apparatus, which is characterized in that the warp amount of the bottom of the container is determined based on the determination results of the first warp amount determination operation and the second warp amount determination operation. In the induction heating cooker according to claim 1,
When it is determined that the warp amount is smaller than the reference in at least one of the first warp amount determination operation and the second warp amount determination operation, the detection temperature is predetermined in the third period after the second period. An induction heating cooker, characterized in that the temperature rise for calculation required to rise from the calculation start temperature to the calculation end temperature is detected, and the boiling time is calculated using the calculation temperature rise time. In the induction heating cooker according to claim 1 or 2.
If it is not determined that the warp amount is smaller than the reference in any of the first warp amount determination operation and the second warp amount determination operation, it is detected as the degree of change in the second period by the second warp amount determination operation. An induction heating cooker, characterized in that the boiling time is calculated using the determination temperature rise time required for the detection temperature to rise from a predetermined determination start temperature to the determination end temperature.

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