WO2011096214A1

WO2011096214A1 - Induction cooking appliance and control method therefor

Info

Publication number: WO2011096214A1
Application number: PCT/JP2011/000595
Authority: WO
Inventors: 新太郎野口; 忠明伊東; 弘志中澤
Original assignee: パナソニック株式会社
Priority date: 2010-02-03
Filing date: 2011-02-03
Publication date: 2011-08-11
Also published as: JPWO2011096215A1; JP5592410B2; JPWO2011096217A1; WO2011096217A1; WO2011096215A1; WO2011096216A1; JP5681119B2; JPWO2011096213A1; JP5675657B2; WO2011096213A1; JPWO2011096214A1; JPWO2011096216A1; JP5684153B2; JP5684152B2

Abstract

The provided induction cooking appliance has an infrared sensor (13), below a top plate (2), that senses infrared radiation emitted from the bottom of a pot (3) and transmitted through the top plate (2). Said infrared sensor outputs an output voltage corresponding to the temperature of the bottom of the pot (3). On the basis of said output voltage, a stuck-food detection unit (14) detects whether or not food (5) has become burnt and stuck to the bottom of the pot. If so, the stuck-food detection unit outputs stuck-food information. The stuck-food detection unit determines that burnt food (5) has become stuck to the bottom of the pot if the aforementioned output voltage increases, at a rate less than or equal to a given increase rate, from a first output voltage to at least a second output voltage greater than the first output voltage.

Description

Induction heating cooker and control method thereof

The present invention relates to an induction cooking device that performs scoring detection in a normal heating mode and a control method thereof.

Conventionally, this type of induction heating cooker is provided with a function to prevent burning in a specific cooking mode, for example, a stewed cooking mode. When operated in this stewed cooking mode, the induction heating cooker detects boiling with temperature detecting means that detects the temperature of the pan bottom, and after boiling detection, determines the stewed thermal power and continues heating. When the temperature of the cooked food rises abnormally and the temperature at the bottom of the pan rises to a predetermined value or more, it is detected that the cooked product has burned on the pan bottom (see, for example, Patent Document 1). In addition, the induction heating cooker is equipped with a switch that activates the non-burning function, and when the user intentionally operates the non-burning function, it detects the burning from the inclination of the temperature change at the bottom of the pan and reduces the heating power Some of them (for example, refer to Patent Document 2). In addition, there is an infrared sensor that detects infrared rays radiated from the bottom of the pan in the temperature detection means (see, for example, Patent Document 3).

FIG. 7 is a block diagram of an induction heating cooker according to the prior art described in Patent Document 1. In FIG. 7, the inverter circuit 103 flows an induction current through the heating coil 102 to generate a high-frequency magnetic field, and heats the pan 101. The control unit 104 controls the inverter circuit 103 so that the pan 101 is heated with a predetermined heating output, and the temperature detection unit 105 detects the temperature of the pan 101. The boiling detector 106 detects boiling from the temperature and temperature gradient of the pan 101 detected by the temperature detector 105. The boiling power determination unit 107 determines the boiling power after boiling based on the pan bottom temperature and the input power when the boiling is detected by the boiling detection unit 106 and the pattern of temperature change until boiling. The burn detection unit 108 detects that the food in the pan 101 has been burned when the pan bottom temperature detected by the temperature detection unit 105 rises above a predetermined temperature. The cooking mode selection switch 109 can select a mode in which heating control for stewed cooking is automatically performed from among a plurality of cooking modes.

FIG. 8A shows the temperature change of the pan 101 when the cooking mode selection switch 109 selects the stew mode, and FIG. 8B shows the transition of the heating output (electric power). In FIG. 8, the boiling detector 106 detects boiling at time Ta, and the burn detector 108 detects burn at time Tb. When the cooking mode selection switch 109 selects the stew mode, the control unit 104 heats the pan 101 at 1200 W while the temperature detected by the temperature detection unit 105 is 100 ° C. or less. When boiling is detected by the boiling detection unit 106, a signal is output from the boiled power determination unit 107 to the control unit 104 so that the heating power is 400 W. The control unit 104 controls the inverter circuit 103 so that the input heating power of the pan 101 is 400 W. During cooking, the temperature of the pan 101 is stable, but the temperature rises abruptly when the food in the pan 101 is burnt out due to the lack of moisture. And if the temperature of the pan 101 detects 105 degreeC or more, the burning detection part 108 will detect burning, will output burning information to the control part 104, and the control part 104 will stop a heating.

JP-A-10-149875 Japanese Patent Laid-Open No. 9-437 JP 2007-115515 A

However, in the configuration of the induction heating cooker according to the above-described prior art, cooking modes in which the burn-in detection function can be used are limited, and they are limited to low heating cooking such as stew. In addition, when using the burn detection function, the user has to select a specific cooking mode (boiled mode) or a burn prevention function. Moreover, when burning is determined only by a temperature change as in Patent Document 3, there is a problem that burning is detected even in cooking in which the pan becomes hot, such as stir-fried food, which hinders cooking.

An object of the present invention is to solve the above-described problems of the prior art, even when the user performs cooking in a heating mode in which the output set value can be changed without selecting a specific cooking mode or a non-burning prevention function. An object of the present invention is to provide an induction heating cooker that uses a burn-in detection function and that does not interfere with heating because the burn-in detection function is activated due to a malfunction in cooking such as stir-fried pans at high temperatures, and a control method thereof.

In order to solve the problems of the prior art, an induction heating cooker according to the present invention includes a top plate on which a pan is placed, and an inverter including an induction heating coil that is provided under the top plate and heats the pan. An infrared sensor that is provided under the top plate, detects infrared rays emitted from the bottom of the pan and transmitted through the top plate, and outputs an output voltage corresponding to a pan bottom temperature of the pan; and the infrared sensor Based on the output voltage, a burn detection operation is performed to detect whether the food is burned to the bottom of the pan, and a burn detection unit that outputs burn information when detecting that the food has burned to the pan bottom, and a plurality of An output setting unit for selecting one of the output setting values from among the output setting values, and a high-frequency current to the induction heating coil and heating When the heating operation of the inverter is controlled so that the force becomes the output set value, the heating mode which is a control mode in which the output set value can be changed by the output setting unit and heating is stopped, and the heating start key is operated. An induction heating cooker having a standby mode that is a control mode for shifting to the heating mode, and a controller that shifts to the standby mode when the burn information is output during operation in the heating mode; The scoring detection unit detects that the output voltage from the infrared sensor has increased from a predetermined first output voltage value to a second output voltage that is greater than the first output voltage value, and the infrared with respect to the elapsed time. When it is detected that the increase rate of the output voltage from the sensor is equal to or less than a predetermined increase rate, it is detected that the cooked food has burned to the bottom of the pan.

This allows the user to use the burn-in detection function even when cooking in the normal heating mode without selecting a specific cooking mode or burn-in prevention function. The cooking detection function can be continued without causing trouble in heating due to the malfunction detection function.

Moreover, the control method of the induction heating cooking appliance concerning another this invention is as follows.
A top plate on which the pan is placed;
An inverter including an induction heating coil provided under the top plate for heating the pan;
An infrared sensor that is provided under the top plate, detects infrared rays emitted from the bottom of the pan and transmitted through the top plate, and outputs an output voltage corresponding to the pan bottom temperature of the pan;
Based on the output voltage from the infrared sensor, a burn detection operation is performed to detect whether the cooked food has burned to the bottom of the pan, and burnt detection that outputs burnt information upon detecting that the cook has burned to the pan bottom And
An output setting unit for selecting one output setting value from a plurality of output setting values;
Heating is a control mode in which a high-frequency current is supplied to the induction heating coil and the heating operation of the inverter is controlled so that the heating output becomes the output set value, and the output set value can be changed by the output setting unit. Control that shifts to the standby mode when the burn-in information is output during operation in the heating mode, having a standby mode that is a control mode that shifts to the heating mode when the mode and heating are stopped and the heating start key is operated A method for controlling an induction heating cooker comprising:
The scoring detection unit detects that the output voltage from the infrared sensor has increased from a predetermined first output voltage value to a second output voltage value greater than the first output voltage value, and for the elapsed time. The method includes a step of performing control so as to detect that the cooked food has burned to the bottom of the pan when detecting that the increase rate of the output voltage from the infrared sensor is equal to or less than a predetermined increase rate.

According to the induction heating cooker and the control method thereof according to the present invention, the user can use the burn-in detection function without selecting a specific cooking mode or burn-in prevention function, and can feel uncomfortable without malfunction during cooking. You can cook without.

It is a whole block diagram of the induction heating cooking appliance concerning Embodiment 1 of this invention. It is a block diagram of the induction heating cooking appliance of FIG. It is an operation | movement flowchart concerning Embodiment 1 of this invention. It is a graph which shows the output voltage change when a to-be-heated object begins to burn in the induction heating cooking appliance of FIG. It is a graph which shows the output voltage increase rate at the time of charred at the time of cooking in a stir-fry thing and curry stew in the induction heating cooking appliance of FIG. It is an operation | movement flowchart concerning Embodiment 2 of this invention. It is a graph which shows the output change when a to-be-heated object begins to burn in the induction heating cooking appliance which has the operation | movement of FIG. It is a block diagram of the induction heating cooking appliance concerning a prior art. (A) is a graph which shows the temperature change of the stew mode in the induction heating cooking appliance of FIG. 7, (b) is a graph which shows the thermal power (electric power).

An induction heating cooker according to a first invention is provided under a top plate on which a pan is placed, an inverter provided under the top plate and including an induction heating coil for heating the pan, and under the top plate. Infrared sensor that detects infrared rays emitted from the bottom of the pan and transmitted through the top plate and outputs an output voltage corresponding to the pan bottom temperature of the pan, and based on the output voltage from the infrared sensor, A scoring detection operation for detecting whether or not the cooked product is burnt, and when detecting that the cooked product is burnt on the bottom of the pan, a burnt detection unit that outputs burnt information, and a plurality of output setting values, 1 An output setting unit for selecting one of the output set values, and a high-frequency current is supplied to the induction heating coil, and the heating output becomes the output set value A heating mode that is a control mode in which the heating operation of the inverter is controlled and the output setting value can be changed by the output setting unit, and a standby mode that is a control mode that shifts to the heating mode when heating is stopped and the heating start key is operated. And a control unit that shifts to the standby mode when the burn information is output during operation in the heating mode, wherein the burn detection unit is from the infrared sensor. Is detected to increase from a predetermined first output voltage value to a second output voltage that is greater than the first output voltage value, and the rate of increase of the output voltage from the infrared sensor over time is predetermined. When it is detected that the rate of increase is equal to or less than the increase rate, it is detected that the cooked product has burned to the bottom of the pan. As a result, even if the user cooks in the normal heating mode without selecting a specific cooking mode or non-burning prevention function, it can detect burnt, particularly in cooking with high viscosity cooking such as curry, and fry In cooking where the pan becomes hot due to an object or the like, the scorching detection function is activated due to a malfunction, and cooking can be continued without hindering heating.

An induction heating cooker according to a second aspect of the invention is particularly the induction heating cooker according to the first aspect of the invention, wherein the burn-in detection unit has an output voltage from the infrared sensor determined from the predetermined third output voltage value. A timer for measuring an elapsed time until reaching a fourth output voltage value greater than three output voltage values, and when the elapsed time reaches a predetermined elapsed time, the output voltage is changed from the third output voltage value to the fourth output voltage value. When detecting that the increase rate of the output voltage from the infrared sensor with respect to the elapsed time when increasing up to the output voltage value is equal to or less than a predetermined increase rate, it is to detect that the food has burned to the bottom of the pan, Detect scoring faster. Thereby, it is possible to reduce the damage to the pan and the waste of cooking.

In the induction heating cooker according to the third invention, in particular, in the induction heating cooker according to the first or second invention, the first output detection voltage and the third output detection voltage are set to be equal. . As a result, processing can be performed with a small amount of memory using a microcomputer or the like, so that even an inexpensive microcomputer can be realized.

An induction heating cooker according to a fourth aspect of the invention is particularly the induction heating cooker according to any one of the first to third aspects of the invention, wherein the second output detection voltage and the fourth output detection voltage are made equal. Set to. As a result, processing can be performed with a small amount of memory using a microcomputer or the like, so that even an inexpensive microcomputer can be realized.

An induction heating cooker according to a fifth aspect of the invention is particularly the induction heating cooker according to any one of the first to fourth aspects of the invention, wherein the control unit has a predetermined output setting set by the output setting unit. The burn detection operation is prohibited outside the output setting range, and when the output setting is changed from outside the output setting range to within the output setting range, the burn detection operation is performed. As a result, in the normal heating mode, all the thermal power settings, in particular the thermal power settings used for boiling water and high-powered stir-fry cooking, do not prohibit the detection of burnt, Even when stew cooking is continued, the burn detection can be activated.

The control method of the induction heating cooker according to the sixth invention is:
A top plate on which the pan is placed;
An inverter including an induction heating coil provided under the top plate for heating the pan;
An infrared sensor that is provided under the top plate, detects infrared rays emitted from the bottom of the pan and transmitted through the top plate, and outputs an output voltage corresponding to the pan bottom temperature of the pan;
Based on the output voltage from the infrared sensor, a burn detection operation is performed to detect whether or not the food is burnt on the bottom of the pan. And
An output setting unit for selecting one output setting value from a plurality of output setting values;
Heating is a control mode in which a high-frequency current is supplied to the induction heating coil and the heating operation of the inverter is controlled so that the heating output becomes the output set value, and the output set value can be changed by the output setting unit. Control that shifts to the standby mode when the burn-in information is output during operation in the heating mode, having a standby mode that is a control mode that shifts to the heating mode when the mode and heating are stopped and the heating start key is operated A method for controlling an induction heating cooker comprising:
The scoring detection unit detects that the output voltage from the infrared sensor has increased from a predetermined first output voltage value to a second output voltage value greater than the first output voltage value, and for the elapsed time. It includes a step of controlling to detect that the cooked food has burned to the bottom of the pan when detecting that the increase rate of the output voltage from the infrared sensor is equal to or less than a predetermined increase rate. As a result, even if the user cooks in the normal heating mode without selecting a specific cooking mode or non-burning prevention function, it can detect burnt, especially when cooking in highly viscous cooking such as curry, and stir-fry In cooking where the pan becomes hot with an object or the like, the scorching detection function is activated due to a malfunction, and cooking can be continued without hindering heating.

The control method for the induction heating cooker according to the seventh invention is the control method for the induction heating cooker according to the sixth invention, in particular, in the burn detection unit, the output voltage from the infrared sensor is a predetermined third voltage. A timer for measuring an elapsed time from an output voltage value until reaching a fourth output voltage value larger than the third output voltage value;
When the elapsed time reaches a predetermined elapsed time, the burn detection unit detects the output voltage from the infrared sensor with respect to the elapsed time when the output voltage increases from the third output voltage value to the fourth output voltage value. The method further includes a step of controlling to detect that the cooked food has burned to the bottom of the pan when it is detected that the increase rate is equal to or less than a predetermined increase rate. As a result, scoring can be detected more quickly, and it is possible to reduce damage to the pan and waste of cooking.

An induction heating cooker control method according to an eighth invention is the control method for an induction heating cooker according to the sixth or seventh invention, in particular, the first output detection voltage and the third output detection voltage. Set to be equal. As a result, processing can be performed with a small amount of memory using a microcomputer or the like, so that even an inexpensive microcomputer can be realized.

A control method for an induction heating cooker according to a ninth invention is the control method for an induction heating cooker according to any one of the sixth to eighth inventions, in particular, the second output detection voltage and the fourth output detection. The voltage was set to be equal. As a result, processing can be performed with a small amount of memory using a microcomputer or the like, so that even an inexpensive microcomputer can be realized.

An induction heating cooker control method according to a tenth aspect of the invention is particularly the induction heating cooker control method according to any one of the sixth to ninth aspects of the invention, wherein the control unit is set by the output setting unit. The burn detection operation is prohibited when the output setting is outside a predetermined output setting range, and the burn detection operation is performed when the output setting is changed from outside the output setting range to within the output setting range. . As a result, in the normal heating mode, all the thermal power settings, in particular the thermal power settings used for boiling water and high-powered stir-fry cooking, do not prohibit the detection of burnt, Even when stew cooking is continued, the burn detection can be activated.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a perspective view showing the configuration of the induction heating cooker according to the first embodiment of the present invention.

In FIG. 1, a top plate 2 is provided on the upper part of the outer case 1. On the upper surface of the top plate 2, induction heating unit display 4a indicating the heating range of the induction heating unit 4 for induction heating the cooking container (pan) 3 such as a pan by induction heating, and a radiant for heating the metal pan or the like by radiant heat. A heater display 6a indicating the heating range of the heater unit 6 is provided, and a grill 7 for grilling fish and the like, and an operation display unit 8 for operating the heat source and displaying its operating state are provided on the side surface of the outer case 1. Is provided. The operation display unit 8 includes an output setting unit 12 for setting an output set value that is a set value of the heating output of each heat source.

Regarding the induction heating cooker configured as described above, the configuration of the induction heating unit 4 will be described with reference to FIG.

FIG. 2 is a block diagram showing a configuration of the induction heating unit 4 of the induction heating cooker according to the first embodiment of the present invention.

In FIG. 2, a heating coil (induction heating coil) 9 is provided below the top plate 2. Furthermore, an inverter 10 that controls the heating coil 9 and a control unit 11 for operating the inverter 10 are provided below the heating coil 9. Here, the control part 11 is comprised with a computer, for example.

When the output setting value P is set by the output setting unit 12 of the operation display unit 8, the control unit 11 supplies the high-frequency current to the heating coil 9 and the heating of the inverter 10 so that the heating output becomes the output setting value P. Control the behavior. The infrared sensor 13 is composed of an InGaAs pin photodiode or the like and is provided below the top plate 2 below the heating coil 9. The infrared sensor 13 detects infrared rays emitted from the bottom of the cooking vessel 3 and transmitted through the top plate 2. Outputs the output voltage corresponding to the pan bottom temperature. The scoring detector 14 detects scorching of the cooked food based on an output voltage corresponding to the temperature of the pan bottom detected by the infrared sensor 13. When the burn detection unit 14 detects that the food 5 has burned to the bottom of the pan, burn information indicating that the cook 5 has burned to the bottom of the pan is output to the control unit 11.

The operation and action of induction heating cooking configured as described above will be described with reference to FIGS.

FIG. 3 is a flowchart of the induction heating cooker according to the first embodiment of the present invention.

In FIG. 3, first, when the power switch (not shown) is turned on, the induction heating cooker enters a standby mode waiting for a heating instruction. In step 10 (S10), the control unit 11 continues the standby mode state until various cooking modes are selected by a mode selection switch (not shown) in the operation display unit 8. When any of the mode selection switches in the operation display unit 8 is selected, the control unit 11 determines whether the mode selection is the heating mode in step 20 (S20). And when it is not heating mode, the control mode of the control part 11 transfers to control for each cooking mode. If the heating mode is set in S20, the control unit 11 waits until a heating start switch (not shown) is pressed in Step 25 (S25). When a heating start switch (not shown) is pressed in step 25 (S25), the heating operation is started. In step 30 (S30), the burnout detector 14 detects the output voltage V output from the infrared sensor 13. The output voltage V corresponds to the temperature of the cooking vessel 3. The detection of the output voltage V is always performed at least during heating. Next, in step 40 (S40), the burnout detector 14 determines whether the output voltage V of the infrared sensor 13 has reached the first output voltage value V1. The first output voltage value V <b> 1 is set greater than and near the minimum temperature at the bottom of the cooking vessel 3 that can be detected by the infrared sensor 13. That is, by detecting that the output voltage value is equal to or higher than the first output voltage value V <b> 1, the infrared sensor 13 can determine that the output voltage V has risen and temperature measurement of the pan bottom of the cooking container 3 is possible. If the first output voltage value V1 has been reached, in step 50 (S50), the burn detection unit 14 determines whether the output voltage V has reached a second output voltage V2 that is higher than the first output voltage. By confirming that the output voltage V has reached the second output voltage V2 from the first output voltage value V1, it can be confirmed that the cooking vessel 3 has been heated to a high temperature, and the burn detection operation is performed without false detection. be able to. For example, when the cooking container 3 is at a high temperature at the start of heating, or when ambient light enters the infrared sensor 13, the output voltage V is equal to or higher than the second output voltage V2 without passing through the first output voltage value V1. There is a case. In this case, although not shown in FIG. 5, at least the function of the burn detection unit 14 can be stopped. When the output voltage V has reached the second output voltage V2, the burn-in detection unit 14 determines the elapsed time (integrated power) of the output voltage V from the first output voltage V1 to the second output voltage V2 in step 60 (S60). However, it is determined whether the increase rate detected in step 70 (S70) is equal to or less than a predetermined increase rate. If the detected increase rate is larger than the predetermined increase rate, the current heating is cooking in which the pan is heated at a high output such as a stir-fried food, and the scorching detection function is invalidated and heating is continued. If the increase rate is equal to or less than the predetermined increase rate in step 70 (S70), the current cooking is burnt during the cooking of relatively viscous food such as curry in step 80 (S80). It is determined that the food is burnt, and the burnt detection unit 14 outputs burnt information indicating that the food 5 has burned to the bottom of the pan to the control unit 11. The controller 11 stops heating by the inverter 10 or reduces the output based on the burnt information. Note that the output is stopped or reduced due to the degree of damage received by the cooking container 3 due to scoring according to the set heating power by the output setting unit 12, for example, when the set heating power is greater than 500W, the heating output is reduced to 500W and set. When the thermal power is 500 W or less, the heating is stopped, and it is possible to prevent the burning from proceeding to waste all the food.

Next, the rate of increase with respect to the elapsed time (or integrated power) of the output voltage V of the infrared sensor 13 will be described with reference to FIGS. 4A, 4B, and 5. FIG. FIG. 4A is a graph showing the relationship between the heating time until charring occurs and the output voltage V (corresponding to the temperature at the bottom of the pan) when curve A is when cooking fried food and curve B is when cooking curry. It has become. As shown in FIG. 4A, when cooking the fried food, it takes an elapsed time T1 seconds for the output voltage V to change from the first output voltage V1 to the second output voltage V2, and curry cooking takes an elapsed time T2 seconds. Represents. FIG. 4B shows the increase rate of the output voltage V of the fried food and the curry stew by (V2−V1) / T1 and (V2−V1) / T2, that is, slopes. In the fried food cooking, the heating output is larger or the weight of the food in the pan is smaller, so the temperature at the bottom of the pan rises more rapidly. Therefore, it can be seen that the output voltage (the temperature at the bottom of the pan) of the infrared sensor 13 in the case of cooking the stir-fry increases more rapidly than in the curry cooking. As a result, when it is detected that the increase rate of the output voltage V with respect to the predetermined time passage is equal to or less than a predetermined value (burning detection stop determination threshold value), it is determined that the output voltage V is burnt, thereby enabling high output such as fried food cooking. It is possible to avoid unnecessarily performing scoring detection when cooking. In FIG. 4A, the increase rate of the output voltage is assumed to be a slope, but the output voltage of the infrared sensor 13 may be converted into temperature. Further, the increase rate of the output voltage V is calculated by measuring the elapsed time (T1, T2) between the predetermined output voltages (V1-V2), but the output voltage during the predetermined time (not shown). The amount of change in V may be measured and calculated. For example, by measuring the change in the output voltage V in the time from when the output voltage V reaches the second output voltage V2 until the time when the output voltage V reaches the second output voltage V2, the output voltage V is measured. An increase rate of V may be calculated. As the increase rate, a voltage change per unit time may be calculated, or a time change per unit voltage may be calculated. Further, it may be detected using the elapsed times T1 and T2 as they are based on the increase rate. For example, if the elapsed time T is equal to or less than T1, it may be determined as fried food cooking, and if the elapsed time T is greater than T1, it may be determined as fried food cooking.

Although the infrared sensor 13 is an InGaAs pin photodiode, it may be any object that can detect a burnt temperature range with infrared rays, such as a silicon photodiode or a thermopile. Further, although the infrared sensor 13 is located below the heating coil 9, the infrared sensor 13 is not limited to the position below the heating coil 9 as long as the temperature of the cooking container 3 can be read.

In addition, the induction heating cooker according to the present embodiment can set the output set value in a plurality of stages by the output setting unit 12 in the heating mode, and has an output setting range for performing burnt detection. When the output setting range is less than a predetermined set value (for example, less than 1500 W), the burnt detection unit 14 in the heating mode performs burnt detection. When the output setting range is outside the predetermined setting range (for example, 1500 W or more), the burn detection operation by the burn detection unit 14 is prohibited or the burn detection result is invalidated. As a result, it is possible to prevent the cooking from being adversely affected, for example, in the case of boiling water that requires high heating power or a stir-fried food that is lightly loaded and cooked at a high temperature, and that the burnout is detected by mistake and the heating output is insufficient. Further, when the output setting value is changed by the output setting unit 12 from outside the predetermined output setting range to within the predetermined output setting range, a burn-in detection operation is performed. With this configuration, for example, in the case of cooking that is first fried at high heat and then boiled (for example, “meat potato” or “Chikuzen-ni”), the user can detect the burn without changing the mode or operating the burn-in prevention switch. It can be carried out.

As described above, even if the user cooks in the normal heating mode without selecting a specific cooking mode or a non-burning function, it is possible to detect burning especially in cooking with high viscosity like curry. In cooking where the pan becomes hot due to fried foods, etc., the burn detection function is automatically disabled so that the burn detection function can be activated due to malfunction and continue cooking without causing problems with heating. can do.

(Embodiment 2)
FIG. 5 is a flowchart of the induction heating cooker according to the second embodiment of the present invention, and FIG. 6 shows the elapsed time (heating time) of the infrared sensor 13 and the output voltage V when the stir-fried food and curry stew are burnt. It is a graph showing the relationship.

The flowchart of FIG. 5 is characterized in that the processing of Step 41 (S41) to Step 45 (S45) is added between Step 40 (S40) and Step 50 (S50) as compared to the flowchart of FIG. The description of the same parts as those in the first embodiment in FIG. 3 is omitted, and different parts will be described.

In FIG. 5, step 41 (S41) to step 45 (S45) are added between step 40 (S40) and step 50 (S50) of FIG. As shown in FIG. 5, after the burnout detection unit 14 reaches the first output voltage V1 in step 40 (S40), the output voltage V of the infrared sensor 13 is larger than the first output voltage value V1 in step 41 (S41). It is determined whether the output voltage V3 has been reached. When the output voltage V reaches the third output voltage V3, the burn detection unit 14 starts a count timer in step 42 (S42), and is greater than the third output voltage value V3 in step 43 (S43) and the fourth output voltage. It is determined whether a fourth output voltage V4 smaller than the value V4 has been reached. When the output voltage V reaches the fourth output voltage V4, the count timer is stopped in step 44 (S44), and the time T for changing from the third output voltage V3 to the fourth output voltage V4 is measured. And if it detects that the increase rate when the output voltage V increases from the 3rd output voltage value V3 to the 4th output voltage value is below a predetermined increase rate, it will detect that the food 5 has burned to the pan bottom, At 80 (S80), the burn is confirmed. If the increase rate when the output voltage V increases from the third output voltage value V3 to the fourth output voltage value is greater than the predetermined increase rate, the second output voltage is reached in step 50 (S50). Wait for. This increases the degree of freedom of design because the detection of the rate of increase for determining whether the food is stir-fried or cooked with relatively high viscosity, such as curry, and the output voltage V for determining burnt are different values. When the design is changed according to the experimental result, the first output voltage V1 and the second output voltage V2, and the third output voltage V3 and the fourth output voltage V4 can be set separately, so that the design becomes easy. In addition to being able to detect burning, the sudden increase in output voltage can be stopped by burning detection, and malfunction can be prevented.

In addition, even if the setting values of the first output voltage and the third output voltage, or the setting values of the second output voltage and the fourth output voltage are the same, the determination value for burning detection can be set similarly, and the program can be simplified. Processing can be performed with a small amount of memory using a microcomputer.

In addition, the induction heating cooker according to the present embodiment has an output setting range in which the output setting can be set in a plurality of stages by the output setting unit 12 and the burnout detection is performed. The output setting range is a predetermined set value. If it is less than (for example, less than 1500 W), the scoring detection unit 14 in the heating mode performs scoring detection, but if it is outside the predetermined setting range (for example, 1500 W or more), the scoring detection by the scoring detection unit 14 is prohibited. To do. This makes it possible to prevent the cooking from being affected by mistakenly detecting scorching in the case of boiling water requiring high heating power or stir-fry cooking at high temperatures. Then, when the output setting is changed from outside the predetermined output setting range to within the predetermined output setting range, for example, by performing a burnt detection operation, for example, first fried at high heat power and then simmered (for example, “meat potato” or “Chikuzen-ni” In the case of cooking (such as “boiled vegetables”), it is possible to detect the burn without changing the mode or operating the burn prevention switch.

As described above, the induction heating cooker according to the present invention discriminates the state of the object to be heated according to the output setting selected by the user, thereby eliminating false detection of the burn detection function and continuously cooking. It can be applied to any type of induction heating cooker, such as a built-in induction heating cooker, an induction heating cooker used on a tabletop, or a stationary induction heating cooker.

2 Top plate 3 Cooking container (pot)
9 Heating coil (induction heating coil)
DESCRIPTION OF SYMBOLS 10 Inverter 11 Control part 12 Output setting part 13 Infrared sensor 14 Burning detection part

Claims

A top plate on which the pan is placed;
An inverter including an induction heating coil provided under the top plate for heating the pan;
An infrared sensor that is provided under the top plate, detects infrared rays emitted from the bottom of the pan and transmitted through the top plate, and outputs an output voltage corresponding to the pan bottom temperature of the pan;
Based on the output voltage from the infrared sensor, a burn detection operation is performed to detect whether or not the food is burnt on the bottom of the pan. And
An output setting unit for selecting one output setting value from a plurality of output setting values;
Heating is a control mode in which a high-frequency current is supplied to the induction heating coil and the heating operation of the inverter is controlled so that the heating output becomes the output set value, and the output set value can be changed by the output setting unit. Control that shifts to the standby mode when the burn-in information is output during operation in the heating mode, having a standby mode that is a control mode that shifts to the heating mode when the mode and heating are stopped and the heating start key is operated An induction heating cooker comprising:
The scoring detection unit detects that the output voltage from the infrared sensor has increased from a predetermined first output voltage value to a second output voltage value greater than the first output voltage value, and for the elapsed time. An induction heating cooker characterized by detecting that the cooked food has burned to the bottom of the pan when detecting that the increase rate of the output voltage from the infrared sensor is equal to or less than a predetermined increase rate.
The burn detection unit includes a timer for measuring an elapsed time from when the output voltage from the infrared sensor reaches a fourth output voltage value larger than the third output voltage value from a predetermined third output voltage value,
When the elapsed time reaches a predetermined elapsed time, the burn detection unit detects the output voltage from the infrared sensor with respect to the elapsed time when the output voltage increases from the third output voltage value to the fourth output voltage value. 2. The induction heating cooker according to claim 1, wherein when the increase rate is detected to be equal to or less than a predetermined increase rate, it is detected that the cooked food has burned to the bottom of the pan.
The induction heating cooker according to claim 1 or 2, wherein the first output detection voltage and the third output detection voltage are set to be equal.
The induction heating cooker according to any one of claims 1 to 3, wherein the second output detection voltage and the fourth output detection voltage are set to be equal to each other.
The control unit prohibits the burn detection operation when the output setting set by the output setting unit is outside a predetermined output setting range, and the output setting is changed from outside the output setting range to within the output setting range. 5. The induction heating cooker according to claim 1, wherein the burn detection operation is performed.
A top plate on which the pan is placed;
An inverter including an induction heating coil provided under the top plate for heating the pan;
An infrared sensor that is provided under the top plate, detects infrared rays emitted from the bottom of the pan and transmitted through the top plate, and outputs an output voltage corresponding to the pan bottom temperature of the pan;
Based on the output voltage from the infrared sensor, a burn detection operation is performed to detect whether or not the food is burnt on the bottom of the pan. And
An output setting unit for selecting one output setting value from a plurality of output setting values;
Heating is a control mode in which a high-frequency current is supplied to the induction heating coil and the heating operation of the inverter is controlled so that the heating output becomes the output set value, and the output set value can be changed by the output setting unit. Control that shifts to the standby mode when the burn-in information is output during operation in the heating mode, having a standby mode that is a control mode that shifts to the heating mode when the mode and heating are stopped and the heating start key is operated A method for controlling an induction heating cooker comprising:
The scoring detection unit detects that the output voltage from the infrared sensor has increased from a predetermined first output voltage value to a second output voltage value greater than the first output voltage value, and for the elapsed time. An induction heating cooker characterized by including a step of detecting when the rate of increase of the output voltage from the infrared sensor is equal to or less than a predetermined rate of increase, to detect that the food has burned to the bottom of the pan. Control method.
The burn detection unit includes a timer for measuring an elapsed time from when the output voltage from the infrared sensor reaches a fourth output voltage value larger than the third output voltage value from a predetermined third output voltage value,
When the elapsed time reaches a predetermined elapsed time, the burn detection unit detects the output voltage from the infrared sensor with respect to the elapsed time when the output voltage increases from the third output voltage value to the fourth output voltage value. The induction heating cooker according to claim 6, further comprising a step of controlling to detect that the cooked product has burned on the bottom of the pan when detecting that the increase rate is equal to or less than a predetermined increase rate. Control method.
The method for controlling an induction heating cooker according to claim 6 or 7, wherein the first output detection voltage and the third output detection voltage are set to be equal to each other.
The method for controlling an induction heating cooker according to any one of claims 6 to 8, wherein the second output detection voltage and the fourth output detection voltage are set to be equal to each other.
The control unit prohibits the burn detection operation when the output setting set by the output setting unit is outside a predetermined output setting range, and the output setting is changed from outside the output setting range to within the output setting range. The induction heating cooker control method according to any one of claims 6 to 9, further comprising a step of performing the burn-in detection operation.