WO2011096215A1

WO2011096215A1 - Induction cooker and control method for same

Info

Publication number: WO2011096215A1
Application number: PCT/JP2011/000600
Authority: WO
Inventors: さつき青山; 新太郎野口; 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; WO2011096216A1; JP5681119B2; JPWO2011096213A1; JP5675657B2; WO2011096214A1; WO2011096213A1; JPWO2011096214A1; JPWO2011096216A1; JP5684153B2; JP5684152B2

Abstract

When in a heating mode having a configurable output, a scorch detection unit (5) outputs scorch information if the output voltage (V) of an infrared sensor (4), which detects the infrared rays from a pot (1), increases from a first output voltage value (V1) to a second output voltage value (V2) or above. After the scorch information is input to a control unit (7), the control unit (7) stops the heating if the output voltage (V) reaches a third output voltage value (V3) which is set to be lower than an output voltage (V0) at which heating is suspended when scorch information is not input. The control unit (7) does not implement heating control on the basis of the scorch information when heating at an output setting value of at least a predetermined value, or when the rate of temperature increase of the pot (1) is at least a predetermined value. When carrying out high output cooking such as frying in the heating mode, scorching can be detected without the unnecessary suspension of heating.

Description

Induction heating cooker and control method thereof

The present invention relates to an induction heating cooker having a scorch detection function and a control method thereof.

A cooking device according to the prior art having a burn-in detection function performs a boiling detection operation after the start of heating, and the temperature and input power when the boiling is detected and the temperature change pattern until the boiling is detected. The state quantity such as the viscosity and capacity of the existing food is judged, and the cooking power required for heating after boiling is determined. In addition, during boiling cooking, when it is detected that stock broth has run out and the temperature at the bottom of the pan has risen to a predetermined value or higher, it is judged that the broth has run out and the cooked food has burned to the pan, and automatic boiling is performed. It has the structure which has a cooking mode (for example, refer patent document 1).

FIG. 6 is a block diagram of an induction heating cooker according to the prior art, and FIG. 7 is a flowchart showing its operation. In FIG. 6, the top plate 2 is a crystallized ceramic plate provided on the upper surface of the induction heating cooker, and the induction heating coil 3 is provided below the top plate 2. When the pan 1 is heated, the pan 1 is placed on the top plate 2 such that the bottom of the pan faces the induction heating coil 3. The inverter circuit 108 a includes a switching element and a resonance capacitor, constitutes an inverter together with the induction heating coil 3, and supplies a high frequency current to the induction heating coil 3. The controller 107 controls on / off of the switching element of the inverter circuit 108a to control the heating output. In order to detect the temperature of the pan 1, a thermistor 104 for measuring the back surface temperature of the top plate 2 is provided. The thermistor 104 outputs the detection result to the control unit 107. The operation unit 110 operated by the user of the induction heating cooker is provided with an output setting unit 110a, a heating start key 110b for starting a heating operation, and a control mode selection key 110c for selecting an operation mode. Yes. The output setting unit 110a is provided with a down key 110aa for decreasing the output set value by one step each time the button is pressed during operation in the heating mode, and an up key 110ab for increasing the output set value by one step each time the button is pressed. ing.

The operation of the induction heating cooker according to the prior art will be described below with reference to FIG. When the power switch 106 is turned on (S301), the control unit 107 enters a standby mode. The control unit 107 stops the heating operation when in the standby mode, and selects one operation mode from a plurality of operation modes including the stew mode by operating the control mode selection key 110c of the operation unit 110. Is possible. When the operation mode is selected in the standby mode (S302) and the heating start key 110b is pressed (S303), the heating operation is started in the selected operation mode. When the stew mode is selected and the heating operation is started (YES in S304), the control unit 107 prohibits the user from changing the output setting value by the output setting unit 110a, as described in Patent Document 1. In addition, after the boiling detection operation is performed, the heating output is automatically controlled, and when it is detected that the temperature of the pan 1 has risen abnormally, the burning detection function for detecting burning is activated (S306). When the heating mode is not selected, for example, when the heating mode is selected and the heating operation is started (NO in S304), the control unit 107 does not operate the burn detection function (S305), and the user sets the output setting unit 110a. It is possible to change the output set value by using.

JP-A-10-149875

However, in the configuration of the induction heating cooker according to the related art, the cooking mode in which the burn-in detection function works is limited to the stew mode, and in the stew mode, changing the output set value by the output setting unit 110a is prohibited. That is, in the heating mode in which the user can change the output setting value with the output setting unit 110a, the burn-in detection function cannot be activated, and the heating output is automatically set in order to use the burn-in detection function. There was a problem that the stew function must be selected.

The object of the present invention is to solve the above-mentioned conventional problems and provide a scoring detection function when it is assumed that a scoring detection function is necessary even when cooking is performed in a heating mode in which a heating output can be freely selected by a user's operation. In addition, if the burn-in detection function is activated unnecessarily and may adversely affect the cooking operation, the burn-in detection function is disabled so that the negative influence on the normal cooking operation in the heating mode is suppressed. It is another object of the present invention to provide an easy-to-use induction heating cooker that can prevent the degree of scoring from getting worse and a control method therefor.

The induction heating cooker according to the present invention is provided with a top plate for placing a pan, an inverter including an induction heating coil provided under the top plate for heating the pan, and provided under the top plate, An infrared sensor that detects infrared rays emitted from the bottom of the pan and passes through the top plate and outputs an output voltage corresponding to the bottom temperature of the pan; and the output voltage from a predetermined first output voltage value to the first output A scoring detection unit that outputs scoring information indicating that the food is scorched on the bottom of the pan when it is detected that it has increased to a predetermined second output voltage value greater than a voltage value, a first output setting value; An output setting unit for selecting one output set value from a plurality of different output set values including a second output set value higher than the first output set value; and the induction heating A heating mode for controlling the heating operation of the inverter so that the heating output is a heating output corresponding to the selected output setting value, and after inputting the burn information, The output voltage is set to be lower than a predetermined output voltage value used for stopping the heating operation or suppressing the heating output when the output voltage is not less than the second output voltage value and the burnt information is not input. A control unit that controls the heating operation based on the burnt information and stops the heating operation or suppresses the heating output when the voltage is equal to or higher than a predetermined third output voltage value. When the first output set value is selected during operation in the heating mode, the control unit performs control of the heating operation based on the burnt information, When the second output set value is selected, the control of the heating operation based on the burn information is prohibited and the heating operation is continued. When the first output set value is selected, the output voltage is When the burn detection unit detects that the elapsed time from the first output voltage value to the predetermined fourth output voltage value set to be equal to or lower than the third output voltage value is less than a predetermined determination value, the burn Control of the heating operation based on information is prohibited, and the heating operation is continued.

This makes it possible to detect scorching and prevent scoring from becoming serious when cooking in a heating mode where heating is performed at a heating output selected by the user. In addition, when performing a heating operation at a high output above a predetermined output set value, heating output control based on burnt information is prohibited, and heating output control based on burnt information is not performed, so that water heating or stir-fry is not performed. When cooking at high output such as, for example, when the cook is near a pan and cooking without the need for a burn-in detection function, the burn-in detection function operates and heating stops unnecessarily. It is possible to prevent the heating output from being lowered and the user can continue cooking without feeling uncomfortable, so that the usability is not deteriorated.

According to the induction heating cooker and the control method thereof of the present invention, even when the user performs the heating operation in the heating mode, which is the operation mode in which the user selects the heating output and performs the cooking, when cooking is cooked It is possible to stop heating automatically by detecting burnt or to weaken the heating output so that the burnt state does not worsen, and is unnecessary when cooking at high temperature such as fried cooking It is possible to improve usability by preventing the burn-in detection function from operating.

It is a block diagram which shows the structure of the induction heating cooking appliance which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the burning detection part 5 of the induction heating cooking appliance which concerns on Embodiment 1 of this invention. It is a flowchart which shows the heat processing in the heating mode of the induction heating cooking appliance which concerns on Embodiment 1 of this invention. It is a flowchart which shows the temperature gradient determination process performed by the burning detection part 5 of FIG. It is a graph which shows the time change of the output voltage V of the infrared sensor 4 after the heating start in Embodiment 1 of this invention. It is a block diagram of the induction heating cooking appliance which concerns on a prior art. It is a flowchart which shows operation | movement of the induction heating cooking appliance which concerns on a prior art.

An induction heating cooker according to a first invention is provided under a top plate on which a pan is placed, an inverter including an induction heating coil provided under the top plate and heating the pan, and under the top plate. Detecting an infrared ray radiated from the bottom of the pan and passing through the top plate and outputting an output voltage corresponding to a bottom surface temperature of the pan; and the output voltage from a predetermined first output voltage value A burnout detection unit that outputs burnt information indicating that the food has burnt on the bottom of the pan when detecting an increase to a predetermined second output voltage value greater than one output voltage value, and a first output set value An output setting unit for selecting one output setting value from a plurality of different output setting values including a second output setting value higher than the first output setting value, and the guidance A heating mode for controlling the heating operation of the inverter so as to supply a high-frequency current to the heating coil and a heating output corresponding to the selected output setting value; The output voltage is set to be lower than a predetermined output voltage value used for stopping the heating operation or suppressing the heating output when the output voltage is not less than the second output voltage value and the burned information is not input. A control unit that controls the heating operation based on the burned information and stops the heating operation or suppresses the heating output when the voltage is equal to or higher than a predetermined third output voltage value. The control unit executes control of the heating operation based on the burnt information when the first output set value is selected during the operation in the heating mode. When the second output set value is selected, control of the heating operation based on the burnt information is prohibited and the heating operation is continued. When the first output set value is selected, the output voltage is When the burn detection unit detects that an elapsed time from the first output voltage value to a predetermined fourth output voltage value set to be equal to or lower than the third output voltage value is less than a predetermined determination value, Control of the heating operation based on the burnt information is prohibited, and the heating operation is continued. Therefore, in the heating mode, which is an operation mode in which cooking is performed by selecting a heating output, it is possible to detect the burn and prevent the burned state from deteriorating, so that the usability can be improved. When the second output set value corresponding to high heating output is selected, control of the heating operation based on the burnt information is prohibited and the burnout detection function is disabled so that the heating output is stopped unnecessarily. Can be avoided or suppressed. Further, even when the first output set value corresponding to the relatively low output heating output used in stew cooking is selected and operated, the output voltage is changed from the first output voltage value to the fourth output voltage. If the elapsed time to reach the value is less than the predetermined judgment value, it is judged that the fried food is being cooked and the control of the heating operation based on the burnt information is prohibited so that the burnout detection function does not work and is used Contrary to the user's intention, the heating output is not unnecessarily reduced, and the usability can be improved.

An induction heating cooker according to a second aspect of the invention is particularly the induction heating cooker of the first aspect of the invention, in which the output set value is changed from the second output set value while the control unit is operating in the heating mode. When the first output set value is changed, the heating operation is controlled based on the burnt information. Therefore, even when the second output set value is selected, when the first output set value is selected, the burn-out detection operation is performed by executing the control of the heating operation based on the burn-in information. The burn-in detection function can be accurately performed with the changed output setting value including acceptance / rejection of the function.

An induction heating cooker according to a third invention is, in particular, the induction heating cooker according to the first or second invention, comprising a heating start key that is an operation switch, and the control unit selects a heating mode and performs the heating. When the start key is operated, the output set value is set to a first output set value that is smaller than a predetermined maximum output set value and greater than a predetermined minimum output set value, and the heating operation is performed in the heating mode. And Therefore, when the heating start key is operated, it is automatically set to an intermediate predetermined output set value at which the burn-in detection operation works, so that the usability can be improved.

In an induction heating cooker according to a fourth invention, in particular, in the induction heating cooker according to the first to third inventions, the control unit has the output voltage larger than the first output voltage value at the start of heating. And when it is more than the predetermined 5th output voltage value set below the 2nd output voltage value, control of the heating operation based on the burning information is prohibited, and the heating operation is performed in the heating operation mode. Therefore, the heating operation can be continued without unnecessarily stopping the heating operation or suppressing the heating output.

According to a fifth aspect of the present invention, there is provided a method for controlling an induction heating cooker comprising: a top plate on which a pan is placed; an inverter including an induction heating coil provided under the top plate for heating the pan; An infrared sensor that detects infrared rays radiated from the bottom of the pan and transmitted through the top plate and outputs an output voltage corresponding to the bottom temperature of the pan; and the output voltage is a predetermined first output voltage. A scoring detection unit that outputs scoring information indicating that the food is scorched on the bottom of the pan when it is detected that the value has increased from a value to a predetermined second output voltage value greater than the first output voltage value; An output setting unit for selecting one output set value from a plurality of different output set values including one output set value and a second output set value higher than the first output set value; A heating mode for controlling the heating operation of the inverter so as to supply a high frequency current to the induction heating coil and a heating output corresponding to the selected output setting value is input, and the burnt information is input. Thereafter, when the output voltage is equal to or higher than the second output voltage value and the burned information is not input, the output voltage is lower than a predetermined output voltage value used for stopping the heating operation or suppressing the heating output. A control unit that controls the heating operation based on the burnt information, which stops the heating operation or suppresses the heating output when the voltage is equal to or higher than a predetermined third output voltage value to be set. A heating operation based on the burnt information when the first output set value is selected while the control unit is operating in the heating mode. While executing the control, when the second output set value is selected, the control of the heating operation based on the burnt information is prohibited, the heating operation is continued, and the first output set value is selected In addition, the burn detection that the elapsed time until the output voltage reaches a predetermined fourth output voltage value set to be equal to or less than the third output voltage value from the first output voltage value is less than a predetermined determination value. When the unit detects it, the control of the heating operation based on the burnt information is prohibited, and the heating operation is continued.

The induction heating cooker control method according to a sixth aspect of the invention is particularly the induction heating cooker control method according to the fifth aspect of the invention, wherein the output set value is set while the control unit is operating in the heating mode. When the second output set value is changed to the first output set value, the method further includes a step of controlling the heating operation based on the burnt information.

The induction heating cooker control method according to the seventh aspect of the invention is particularly the induction heating cooker control method according to the fifth or sixth aspect of the invention, wherein the induction heating cooker has a heating start key that is an operation switch. And when the heating mode is selected and the heating start key is operated, the controller sets the output set value to be smaller than a predetermined maximum output set value and greater than a predetermined minimum output set value. And a heating operation in the heating mode.

The method for controlling the induction heating cooker according to the eighth aspect of the invention is particularly the control method for the induction heating cooker according to the fifth to seventh aspects of the invention, wherein the control unit is configured to output the output voltage when starting heating. When it is greater than a first output voltage value and greater than or equal to a predetermined fifth output voltage value set to be less than or equal to the second output voltage value, control of the heating operation based on the burn information is prohibited and heating operation is performed in the heating operation mode. The method further includes the step of:

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 an overall circuit block diagram of an induction heating cooker according to Embodiment 1 of the present invention, FIG. 2 is a block diagram of a burnt detection unit 5 in FIG. 1, and FIG. 3 is this embodiment. 4 is a flowchart showing a heating process in the heating mode of the induction heating cooker according to FIG. 4, and FIG. 4 is a flowchart showing a temperature gradient determination process executed by the burnt detection unit 5 of FIG. FIG. 5 is a diagram showing the time change of the output voltage V of the infrared sensor 4 after the start of heating.

In FIG. 1, the top plate 2 is a ceramic plate provided on the top surface of the induction heating cooker, and the induction heating coil 3 is provided below the top plate 2. The pan 1 is placed on the top plate 2 at a position facing the induction heating coil 3. Further, as shown in FIG. 2, a rectifier 9 c that rectifies AC power from an AC power source 9 a, a switching element, and a resonance capacitor are included, and an inverter 8 is configured together with the induction heating coil 3 to supply a high frequency current to the induction heating coil 3 An inverter circuit 8a, an input current detector 9b for measuring the input current of the inverter 8, and a controller 7 for controlling the heating output by controlling the switching elements of the inverter circuit 8a are provided. The induction heating coil 3 generates a high frequency magnetic field when a high frequency current is supplied. When the high frequency magnetic field is linked to the bottom surface of the pan 1, an eddy current is induced on the bottom surface of the pan 1, and the eddy current generates Joule heat and the bottom surface is inductively heated.

In FIG. 1, an operation unit 10 for a user to input a control command includes an output setting unit 10a, a heating start key 10b for starting a heating operation, and a control for selecting an operation mode. A mode selection key 10c is provided. The output setting unit 10a is provided with a down key 10aa for decreasing the output set value corresponding to the heating output of the induction heating coil 3 by one step and an up key 10ab for increasing the output set value by one step. ing. The user can set the heating output of the induction heating coil 3 by operating the keys 10aa and 10ab to select one output setting value from among a plurality of stages of output setting values. For example, when the number of stages of the output set value is 6, when the output set value is 1, the heating output is set to 100 W, when the output set value is 2, the heating output is set to 300 W, and when the output set value is 3 The heating output is set to 700 W. When the output set value is 4, the heating output is set to 1000 W. When the output set value is 5, the heating output is set to 1450 W. When the output set value is 6, the heating output is 2000 W. Is set. Hereinafter, among the output setting values 1 to 6, the

output setting values

1, 2, 3, and 4 corresponding to the “low output” heating output are referred to as the first output setting value W1 and correspond to the “high output” heating output. The set

output values

5 and 6 are referred to as a second set output value W2.

When the power switch 6 is turned on (on), the control mode of the control unit 7 becomes a standby mode in which heating is stopped. In the standby mode, the user can select an operation mode that is a control mode for controlling the operation during the heating operation. The user can select one operation mode from a plurality of operation modes by operating the control mode selection key 10c in the standby mode. Here, the plurality of operation modes include, for example, a heating mode and a fried food mode. The heating mode is an operation mode in which a heating operation is performed with a heating output corresponding to the output set value selected by the user as described above, and the fried food mode is an operation mode for fried food.

When the heating start key 10b is pressed (operated) in the standby mode after the heating mode is selected, the heating operation is started, and the control unit 7 automatically sets the output set value to 4 (that is, The heating output is 1000 W.) and the mode is changed to the heating mode. The heating mode is an operation mode in which the heating operation is performed with the output set value selected by the user. The output setting unit 10a includes an up key 10ab and a down key 10aa. When the control unit 7 operates in the heating mode, the user changes the output set value by operating the output setting unit 10a. Can do. When the output setting value is changed by the operation of the output setting unit 10a, the output setting unit 10a outputs the output setting information for notifying the changed output setting value to the control unit 7. The control unit 7 monitors the input current of the inverter 8 with the input current detection unit 9b including the current transformer, and configures the inverter circuit 8a so that the heating output becomes a value corresponding to the changed output set value. A switching element (not shown) is controlled to supply a required high-frequency current to the induction heating coil 3.

The infrared sensor 4 detects infrared rays emitted from the bottom surface of the pan 1 and transmitted through the top plate 2, and outputs an output voltage V corresponding to the bottom surface temperature of the pan 1 to the control unit 7. When the controller 7 operates in the heating mode, as shown in FIG. 5, the output voltage V is a predetermined output voltage value V0 (for example, the output voltage value V0 is the bottom temperature of the pan 1 is the ignition temperature of oil). This is the output voltage V when the temperature is about 300 ° C.) When the temperature is higher than that, heating is stopped to prevent oil ignition. Further, the control unit 7 has a fried food mode that is an operation mode for fried food. When the control unit 7 operates in the deep-fried food mode, the output voltage V is a predetermined output voltage value (not shown) (for example, the output voltage value V when the bottom temperature of the pan 1 is about 180 ° C.). ) Control to stop heating or increase / decrease heating output so as to stabilize.

Next, the configuration of the burn-in detection unit 5 and the burn-in detection operation will be described with reference to FIGS. The output voltage values V0 to V6, times t0 to t5, the first elapsed time T0, the boiled food determination value T01, the second elapsed time T1 and the fried food determination value T11 of the infrared sensor 4 described below are shown in FIG. Are listed.

Here, the output voltage values V0 to V6 (V1 <V6 <V2 ≦ V3 <V0) are defined as follows with respect to the bottom surface temperature of the pan 1.
(1) Output voltage value V0: During the operation in the heating mode, when the control of the heating operation based on the burn information described later from the burn detection unit 5 is prohibited and the heating operation is continued, the control unit 7 performs the heating operation. It is an output voltage value corresponding to a predetermined heating stop temperature to be stopped, and the heating stop temperature is, for example, an oil ignition temperature (300 ° C.).
(2) First output voltage value V1: A predetermined output voltage value substantially corresponding to the lowest temperature (for example, 129 ° C.) that can be measured by the infrared sensor 4.
(3) 2nd output voltage value V2: It is the temperature when the degree of burning of the pot bottom of the pot 1 is relatively small (when burning starts), and the temperature gradient of the heated object is “large”, Alternatively, a predetermined output voltage value corresponding to a predetermined temperature (for example, 159 ° C.) used to determine whether it is “medium”.
(4) Third output voltage value V3: a predetermined burn determination temperature (for example, 230 ° C.) for determining the burn of a high-viscosity heated object such as curry whose temperature gradient is determined to be “medium” A predetermined output voltage value corresponding to.
(5) Fourth output voltage value V4: A predetermined output voltage value when the measurement of the second elapsed time T1 is finished (V1 <V4 ≦ V3, and V4 = V2 may be used as shown in FIG. 5). .
(6) Fifth output voltage value V5: Predetermined output voltage value (V1 <V5 ≦ V2 when prohibiting the control of the heating operation based on the burnt information at the start of heating. As shown in FIG. 5, V5 = V2 may also be used.)
(7) Sixth output voltage value V6: a predetermined burn determination temperature (for example, 135 ° C.) for determining the burn of a low-viscosity heated object such as boiled food, for which the temperature gradient is determined to be “small” A predetermined output voltage value corresponding to.

The first elapsed time T0, the boiled food determination value T01, the second elapsed time T1 and the fried food determination value T11 are defined as follows.
(1) First elapsed time T0: Elapsed time after starting the heating operation at time t0.
(2) Boiled food determination value T01: A predetermined elapsed time after starting the heating operation at time t0 (for example, 2 minutes) for determining whether the object to be heated is a low-viscosity food such as boiled food. .
(3) Second elapsed time T1: Elapsed time from the time when the voltage value of the output voltage V of the infrared sensor 4 becomes the first output voltage value V1.
(4) Stir-fried determination value T11: The voltage value of the output voltage V of the infrared sensor 4 used for determining whether the temperature gradient is “large” or “medium” is the first output voltage value V1. A predetermined elapsed time from the time when it became (for example, 20 to 200 seconds)

With reference to FIG. 3, the heating process in the heating mode of the induction heating cooking appliance which concerns on this Embodiment is demonstrated. In FIG. 3, the portion showing the burn-in detection operation is indicated by a broken line. When the heating mode is selected and the heating start key 10b is operated during the standby mode (YES in S101), and the output setting value corresponding to the heating output is changed by the output setting unit 10a during the operation in the heating mode. In the case (YES in S102), the control unit 7 determines whether the currently set output setting value is the second output setting value W2 corresponding to “high output” or the first output setting corresponding to “low output”. It is determined whether or not the value is W1 (S103). If the output set value is a value equal to or greater than 5 that is the second output set value W2, it is determined that the output is “high output” (YES in S103), and heating based on burned information from the

comparison units

17 and 18 described later is performed. Control of the operation (the process of S111) is prohibited, and the heating operation is continued (S109). In S109, when the output voltage V becomes equal to or higher than the output voltage value V0 (see FIG. 5), the control unit 7 controls the inverter circuit 8a so as to stop heating, thereby preventing oil ignition. . On the other hand, if the output set value is 4 or less, which is the first output set value W1, in S103, it is determined that the output is “low output” (NO in S103), and the scoring detection operation after S104 is executed. Continue heating.

That is, when the second output set value W2 is selected and the heating operation is controlled in the heating mode (S109), the control unit 7 changes the output set value to the first output set value W1 by operating the output setting unit 10a. When changed (YES in S102 and NO in S103), the processing after S104 is executed, and the control of the heating operation based on the burning information from the

comparison units

17 and 18 of the burning detection unit 5 is executed. With this configuration, even when the second output set value W2 is selected, when the first output set value W1 is selected and a heating operation is performed, control of the heating operation based on the burn information (burn detection) Therefore, the control of the heating operation based on the burnt information after S104 can be accurately performed with the changed output set value while continuing the heating operation.

Hereinafter, in order to simplify the explanation, it is assumed that the output set value is 4 (the corresponding heating output is 1000 W) and is not changed. The control unit 7 receives the output voltage V of the infrared sensor 4, measures its magnitude, and sends the information to the burn detection unit 5. The burn-in detection unit 5 may input the output voltage V directly from the infrared sensor 4 without the control unit 7 interposed. In FIG. 2, the burn-in detection unit 5 includes a first output voltage value V1, a second output voltage value V2 that is greater than the first output voltage value V1, a third output voltage value V3, and a fourth output voltage value V4. And a temperature storage unit 11 for storing the sixth output voltage value V6 in advance.

The first output voltage value V1 can be, for example, a voltage output from the infrared sensor 4 when the pan bottom of the pan 1 reaches about 129 ° C. The output voltage V of the infrared sensor 4 used in this embodiment is a power function when the bottom surface temperature T of the pan 1 is a variable (y = aT ⁿ , y is the output voltage of the infrared sensor 4, and n is a positive value. It is a real number, and a is a positive real number.) Since it increases like FIG. 5, it increases while increasing an increase gradient with time passage like FIG. For this reason, it is preferable to select a value that is measurable as low as possible and set it as the first output voltage value V1.

The second output voltage value V2 is a voltage output from the infrared sensor 4 when the pan bottom of the pan 1 reaches about 159 ° C. This is because the degree of scorching is relatively small when the pan bottom of the pan 1 is about 159 ° C.

In FIG. 3, following S103, the comparison unit 12 determines whether the output voltage V is equal to or higher than the second output voltage value V2, thereby turning on the heating start key 10b and starting heating. It is determined whether or not the bottom surface temperature of the pan 1 immediately after or the bottom surface temperature of the pan 1 immediately after the output set value is changed during heating is equal to or higher than the temperature corresponding to the second output voltage value V2 (S104). . The control unit 7 determines that the output voltage V immediately after the heating start key 10b is turned on and heating is started, or the output voltage V immediately after the output set value is changed during heating is equal to or higher than the second output voltage value V2. (YES in S104), it is determined as “high temperature”, and the heating operation based on the burn information from the comparison units 17 and 18 (burn detection operation) is prohibited, and the heating operation is continued without being substantially executed. (S109). If it is determined that the temperature is high immediately after the start of heating, it can be assumed that the bottom temperature has already been burnt and the user is in front of the cooked food. I do not disturb. On the other hand, if the output voltage V is less than the second output voltage value V2 (NO in S104), it is determined as “low temperature” and a temperature gradient is determined (S105). In S104, whether the temperature is “high temperature” by a predetermined fifth output voltage value V5 (not shown) that is equal to or lower than the second output voltage value and greater than the first output voltage value V1 instead of the second output voltage value V2. It may be determined whether or not.

The temperature gradient determination process in FIG. 4 is executed by the scorch detection unit 5 in FIG. 2, and a first temperature gradient determination process (S201 to S206) for determining whether or not the temperature gradient of the object to be heated is “small”; And a second temperature gradient determination process (S208) for determining whether the temperature gradient is “medium” or “large”. As shown in FIG. 4, the controller 7 sends a counter reset signal and a count start signal to the second timer circuit 15 when the heating operation is started by the heating start key 10b (time t0). The second timer circuit 15 resets the first elapsed time T0 in response to the reset signal, and starts counting the first elapsed time T0, which is the elapsed time after the start of heating, in response to the count start signal (S201). ). Next, the comparison unit 12 determines whether or not the output voltage V is equal to or higher than the first output voltage V1 (S202). When YES in S202, the comparison unit 12 transmits a counter reset signal and a count start signal to the first timer circuit 14, and in response thereto, the first timer circuit is reset and counts the second elapsed time T1. Start (S204). On the other hand, when NO in S202, the comparison unit 14 determines whether or not the first elapsed time T0 is equal to or greater than the boiled food determination value T01 (S203). If YES in step S203, the process proceeds to step S207. If NO, the process returns to step S202.

As shown in curve A of FIG. 5, when the food in the pan 1 is a simmered food with a lot of moisture and a low viscosity, the bottom temperature of the pan 1 does not become the lowest temperature that can be measured by the infrared sensor 4 unless it is boiled. The output voltage V does not reach the first output voltage value V1. Therefore, before the output voltage V reaches the first output voltage value V1, the first elapsed time T0 becomes the boiled food determination value T01 stored in the time storage unit 16 (time t5). The boiled food determination value T01 can be, for example, about 2 minutes, but is not limited to this value. Thus, when the output voltage V does not reach the first output voltage value V1 even after the simmered determination value T01 has elapsed (YES in S203), the comparison unit 14 increases the bottom temperature of the pan 1 over time. Is “small” and a signal indicating the determination result is sent to the temperature storage unit 11 (S207). As a result of the first temperature gradient determination, if it is not determined that the rising gradient of the bottom surface temperature of the pan 1 is “small” (NO in S206), a second temperature gradient determination process is performed (S208).

On the other hand, if YES in S202, the time when the output voltage V of the infrared sensor 4 becomes the first output voltage value V1 by the first timer circuit 13 in S204 (for example, at time t1 in the case of the curve B in FIG. 5). Yes, in the case of curve C, it is time t2.) The counting of the second elapsed time T1 from the beginning is started. In S205, the comparison unit 12 determines whether or not the output voltage V is equal to or higher than the second output voltage value V2 that is larger than the first output voltage value V1. If NO in S205, the process of S205 is repeated. On the other hand, when YES in S205, the comparison unit 12 outputs an instruction signal to stop counting to the first timer circuit 13, and in response, the first timer circuit 13 stops counting, The second elapsed time T1 corresponding to the count value at the time of stop is output to the comparison unit 18, and the process proceeds to S206. In S206, the comparison unit 14 determines whether or not the first elapsed time T0 is equal to or greater than the boiled food determination value T01. When YES in S206, the comparison unit 14 determines in S207 that the rising gradient of the bottom surface temperature of the pan 1 over time is “small”, and sends a signal indicating the determination result to the temperature storage unit 11. send. On the other hand, if NO in S206, the process proceeds to S208. That is, the first timer circuit 13 has elapsed time from when the output voltage V reaches the first output voltage value V1 until it reaches the second output voltage value V2 (for example, from time t1 to time t4 in the curve B in FIG. 5). Or the time from time t2 to time t4 on curve C) is measured (S204, S205). In S206, it is determined whether or not the temperature gradient is “small”. When it is not determined that the temperature gradient is “small” (NO in S206), the process proceeds to S208. In S <b> 208, the comparison unit 18 determines the fried food in which the second elapsed time T <b> 1 until the output voltage V becomes the second output voltage value V <b> 2 after the output voltage V becomes the first output voltage value V <b> 1 is stored in the time storage unit 16. It is determined whether or not the value is equal to or greater than T11. For example, as shown by the curve B, the fried food determination in which the second elapsed time T1 until the output voltage V becomes the second output voltage value V2 after the output voltage V becomes the first output voltage value V1 is stored in the time storage unit 16 When the value is equal to or greater than the value T11 (YES in S208), the comparison unit 18 determines that the rising gradient of the bottom temperature of the pan 1 is “medium”, and outputs the determination result to the comparison unit 17 (S209). In this case, the comparison unit 17 determines whether or not the output voltage V is greater than or equal to the third output voltage value V3 (S211), and if the output voltage V is greater than or equal to the third output voltage value V3 (YES in S211). The burn information indicating that the cooked food has burned on the bottom of the pot 1 is output to the control unit 7 (S212). Moreover, if the output voltage V is less than the 3rd output voltage value V3, the comparison part 17 will continue heating, without outputting burning information to the control part 7 (it is NO at S211). On the other hand, when the second elapsed time T1 from when the output voltage V reaches the first output voltage value V1 until the second output voltage value V2 is less than the fried food determination value T11 (NO at S208), the comparison unit 18 determines that the rising gradient of the bottom surface temperature of the pan 1 is “large”, and the comparison unit 17 that has input the determination result displays burnt information even if the output voltage V is equal to or higher than the third output voltage value V3. Heating is continued without outputting to the control unit 7 (S210).

The fried food determination value T11 can be set, for example, between 20 seconds and 200 seconds, and can be set to, for example, about 100 seconds. Moreover, it is preferable that the fried food determination value T11 varies according to the plate thickness of the pan. That is, as the plate thickness becomes smaller (thinner), the rate at which the pan temperature rises increases, so it is preferable to set the fried food determination value T11 to be smaller. The thickness of the plate can be judged by the size of the rising speed of the pan temperature during heating. It can be estimated that the plate thickness is smaller (thin) as the rate of increase in the temperature measured by the infrared sensor 4 increases.

Returning to S105 in FIG. 3, if the first temperature gradient determination process (S201 to S206) in FIG. 4 determines that the rising gradient of the bottom temperature of the pan 1 is “small” (YES in S105), “ It is determined that the cooking is stewed such as “meat potato (meat and potato stew)”. The temperature storage unit 11 stores a sixth output voltage value V6 that is smaller than the second output voltage value V2. The sixth output voltage value V6 can be set to about 135 ° C., for example. The sixth output voltage value V6 may be set so that the degree of burning of the object to be heated in the cooking is as low as possible. When the set value of the sixth output voltage value V6 is set too low, there is a possibility that the cooked food is unnecessarily determined to have burnt. In S106, the comparison unit 17 compares the output voltage V with the sixth output voltage value V6, and when the output voltage V becomes equal to or higher than the sixth output voltage value V6 (YES in S106), the cooked food is placed on the bottom of the pot 1. Burn information indicating that the burn has occurred is output to the control unit 7. When the burn-in information is input from the comparison unit 17, the control unit 7 stops the heating operation or suppresses the heating output based on the burn-in information, notifies the burn-in (S111), and returns to S101. With this configuration, the burning of the object to be heated in stew cooking is higher than the burning determination temperature (a temperature corresponding to the third output voltage V3) when it is determined that the object to be heated has a relatively high viscosity such as curry. Detection can be performed earlier with a low burn determination temperature (a temperature corresponding to the sixth output voltage value V6), and heating can be stopped, heating output can be suppressed, or burn can be notified.

When the comparison unit 18 determines that the rising gradient of the bottom surface temperature of the pan 1 is “medium” as a result of the second temperature gradient determination process (S208) (YES in S208), the comparison unit 17 determines the determination result. Is output. The comparison unit 17 determines that the object to be heated has a relatively high viscosity such as curry (S209). In this case, it is determined as NO in S107, and the comparison unit 17 responds to the determination result output from the comparison unit 18 so that the output voltage V is smaller than the predetermined heating stop output voltage value V0 and is the sixth output voltage value. Compared with the third output voltage value V3 higher than V6 (S110), when the output voltage V reaches the third output voltage value V3 (YES in S110), control is performed to stop the heating operation or suppress the heating output. (S111), the process returns to S101. The third output voltage value V3 can be set to about 230 ° C., for example. When the comparison unit 18 determines that the rising temperature of the bottom surface temperature of the pan 1 is “large” as a result of the second temperature gradient determination (NO in S208), the comparison unit 17 is fried food cooking. And the burned information is not output to the control unit 7 (S210). As a result, it is determined as NO in S107, the control of the heating operation based on the burnt information of the control unit 7 is prohibited, and the heating operation is continued (S109).

With this configuration, in the case of a heated object having a relatively high viscosity such as curry, a burn detection operation (S110) at a higher burn determination temperature (a temperature corresponding to the third output voltage value V3) than in the case of boiled food cooking. ) To improve usability without cooking heating unnecessarily or weakening the heating output.

The measurement end time of the second elapsed time T1 used in the second temperature gradient determination process (S208) is the time when the second output voltage value V2 is reached, but is set to be equal to or lower than the third output voltage value V3. It may be the time when the fourth output voltage value V4 is reached, and the fourth output voltage value V4 and the second output voltage value V2 may be the same or different.

As described above, the induction heating cooker according to the present embodiment includes an inverter 8 including a top plate 2 on which the pan 1 is placed and an induction heating coil 3 that is provided below the top plate 2 and heats the pan 1. An infrared sensor 4 that is provided under the top plate 2, detects infrared rays that are emitted from the bottom of the pan 1 and passes through the top plate 2, and outputs an output voltage V corresponding to the bottom temperature of the pan 1; When it is detected that V has increased from a predetermined first output voltage value V1 to a predetermined second output voltage value V2 that is greater than the first output voltage value V1, it indicates that the food has been burned on the bottom of the pan 1 One output setting value from among a plurality of different output setting values including a burnout detection unit 5 that outputs information, a first output setting value W1, and a second output setting value W2 that is higher than the first output setting value W1. choose And a heating mode for controlling the heating operation of the inverter 8 so that a high-frequency current is supplied to the induction heating coil 3 and the heating output is a heating output corresponding to the selected output setting value. After the burn-in information is input, the predetermined output used for stopping the heating operation or suppressing the heating output when the output voltage V is equal to or higher than the second output voltage value V2 and the burn-in information is not input. A control unit 7 for controlling the heating operation based on the burned information, which stops the heating operation or suppresses the heating output when the voltage value is equal to or higher than a predetermined third output voltage value V3 set lower than the voltage value V0; When the first output set value W1 is selected during the operation in the heating mode, the control unit 7 controls the heating operation based on the burnt information. On the other hand, when the second output set value W2 is selected, the control of the heating operation based on the burnt information is prohibited and the heating operation is continued. When the first output set value W1 is selected, the output voltage The second elapsed time T1 until V reaches a predetermined fourth output voltage value V4 set to be equal to or less than the third output voltage value V3 from the first output voltage value V1 is less than the predetermined fried food determination value T11. When the burn-in detection unit 5 detects, control of the heating operation based on the burn-in information is prohibited and the heating operation is continued.

With this configuration, in the heating mode, which is an operation mode in which cooking is performed by selecting a heating output, it is possible to detect scorching and prevent the scoring state from deteriorating. In addition, when a relatively large heating output is set (when the second output set value W2 is selected), such as when cooking a stir-fried dish, the burning is not a problem, in FIG. 3, from the process of S103 to S109. Therefore, it is possible to prevent the heating output from decreasing by detecting that it has been burned unnecessarily.

Even when the first output set value W1 is selected, if the rate of increase in the temperature of the object to be heated is equal to or greater than a predetermined value (YES in S208), the fried food is cooked. Therefore, it is possible to continue the heating operation without stopping the heating operation or suppressing the heating output unnecessarily by determining that the burn is detected and preventing the burn-in detection function from working.

Further, according to the present embodiment, when the second output set value W2 is selected and the heating operation is controlled in the heating mode, the control unit 7 is changed to the first output set value W1 and in the heating mode. When the operation is performed, the control of the heating operation based on the burn-in information from the burn-in detection unit 5 (the processing of S103 to S111 in FIG. 3) is performed. With this configuration, even when the second output set value W2 is selected, when the heating operation is performed with the first output set value selected, the burn detection operation is performed, so the burn detection operation is changed. It is possible to accurately carry out with the set output set value.

Further, according to the present embodiment, the heating start key 10b which is an operation switch is provided. Further, when the heating mode is selected and the heating start key 10b is operated, the control unit 7 sets the output set value to a first output set value W1 that is 4 smaller than the maximum output set value 6 and larger than the minimum output set value 1. The heating operation is performed in the heating mode. With this configuration, the heating output that automatically controls the heating operation based on the burn-in information is set at the start of heating, so that the burn-in function does not work and the chance of the burn-out state getting worse can be reduced.

Moreover, according to this Embodiment, the control part 7 is the predetermined 5th output voltage value by which the output voltage V was set to the 2nd output voltage value V2 or the 2nd output voltage value V2 or less at the time of a heating start. When V5 or higher (YES in S104), control of the heating operation based on the burnt information is prohibited, and the heating operation is performed in the heating operation mode without executing the control of the heating operation based on the burnt information. With this configuration, the heating operation can be continued without unnecessarily stopping the heating operation or suppressing the heating output by the burn-in detection operation.

In addition, according to the present embodiment, the scoring detection unit 5 starts heating that the output voltage V has increased from the first output voltage value V1 to a second output voltage value V2 that is greater than the first output voltage value V1. A second elapsed time T1 from the first output voltage value V1 to the second output voltage value V2 is detected until the time has elapsed by the post-boiled food determination value T01 (NO in S206). When the fried food determination value is equal to or greater than T11 (YES in S208), that is, when it is detected that the rising gradient of the temperature corresponding to the output voltage V with respect to the time passage is below a predetermined value, it is detected that the cooked food has burned to the bottom of the pan. When the bottom temperature of the pan 1 becomes high, the heating stop temperature used for the fried food (the temperature corresponding to the output voltage value V0) is lower than the temperature (the temperature corresponding to the third output voltage value V3). Yes.) Stop heat or inhibit heating output. With this configuration, it is possible to alleviate the burnt state of a highly viscous liquid such as curry.

Further, according to the present embodiment, since the bottom surface temperature of the pan 1 is detected by the infrared sensor 4, the bottom surface temperature of the pan 1 can be detected with good responsiveness when using a temperature sensitive element such as a thermistor. Can be detected with high accuracy.

As described above, the induction heating cooker and the control method thereof according to the present invention can detect scorching in an operation mode in which heating is performed with an output setting value selected by the user, and can output as high as fried food cooking. When cooking in a kitchen, the burn-in detection function will not operate unnecessarily, and cooking can be continued, so it is built-in, tabletop type used on the table, or stationary type used on the table The present invention can be applied to an induction heating cooker for which output can be set for home use or business use.

DESCRIPTION OF SYMBOLS 1 Pan 2 Top plate 3 Induction heating coil 4 Infrared sensor 5 Burning detection part 7 Control part 8 Inverter 10a Output setting part 10b Heating start key 10c Control mode selection key 11 Temperature storage part 12 Comparison part 13 1st timer circuit 14 Comparison part 15 Second timer circuit 16 Time storage unit 17 Comparison unit 18 Comparison unit 19 Power switch T0 First elapsed time T01 Boiled food determination value T1 Second elapsed time T11 Stir-fried food determination value

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 an infrared ray radiated from the bottom of the pan and transmitted through the top plate, and outputs an output voltage corresponding to the bottom temperature of the pan;
When the output voltage is detected to increase from a predetermined first output voltage value to a predetermined second output voltage value that is greater than the first output voltage value, it indicates that the food has been burned on the pan bottom of the pan. A burnt detector that outputs information;
An output setting unit for selecting one of the output setting values from a plurality of different output setting values including a first output setting value and a second output setting value higher than the first output setting value;
A heating mode for controlling the heating operation of the inverter so as to supply a high frequency current to the induction heating coil and a heating output corresponding to the selected output setting value is input, and the burnt information is input. Thereafter, when the output voltage is equal to or higher than the second output voltage value and the burned information is not input, the output voltage is lower than a predetermined output voltage value used for stopping the heating operation or suppressing the heating output. A control unit that controls the heating operation based on the burnt information, which stops the heating operation or suppresses the heating output when the voltage is equal to or higher than a predetermined third output voltage value to be set. A vessel,
The controller is
During operation in the heating mode, when the first output set value is selected, the control of the heating operation based on the burnt information is performed, while the second output set value is selected. Control of the heating operation based on the burnt information is prohibited and the heating operation is continued.
When the first output set value is selected, an elapsed time until the output voltage reaches a predetermined fourth output voltage value set to be equal to or lower than the third output voltage value from the first output voltage value. An induction heating cooker characterized in that when the burn detection unit detects that the value is less than a predetermined determination value, control of the heating operation based on the burn information is prohibited and the heating operation is continued.
When the output set value is changed from the second output set value to the first output set value during operation in the heating mode, the control unit executes control of the heating operation based on the burnt information. The induction heating cooker according to claim 1.
It has a heating start key that is an operation switch,
When the heating mode is selected and the heating start key is operated, the control unit sets the output set value to a first output set value that is smaller than a predetermined maximum output set value and larger than a predetermined minimum output set value. The induction heating cooker according to claim 1, wherein the heating operation is performed in the heating mode.
When the control unit starts heating, the burn-in information indicates that the output voltage is greater than or equal to a predetermined fifth output voltage value set greater than the first output voltage value and less than or equal to the second output voltage value. The induction heating cooker according to any one of claims 1 to 3, wherein the control of the heating operation based on the heating operation is prohibited and the heating operation is performed in the heating operation mode.
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 an infrared ray radiated from the bottom of the pan and transmitted through the top plate, and outputs an output voltage corresponding to the bottom temperature of the pan;
When the output voltage is detected to increase from a predetermined first output voltage value to a predetermined second output voltage value that is greater than the first output voltage value, it indicates that the food has been burned on the pan bottom of the pan. A burnt detector that outputs information;
An output setting unit for selecting one of the output setting values from a plurality of different output setting values including a first output setting value and a second output setting value higher than the first output setting value;
A heating mode for controlling the heating operation of the inverter so as to supply a high frequency current to the induction heating coil and a heating output corresponding to the selected output setting value is input, and the burnt information is input. Thereafter, when the output voltage is equal to or higher than the second output voltage value and the burned information is not input, the output voltage is lower than a predetermined output voltage value used for stopping the heating operation or suppressing the heating output. A control unit that controls the heating operation based on the burnt information and stops the heating operation or suppresses the heating output when the voltage is equal to or higher than a predetermined third output voltage value to be set. A method of controlling the vessel,
The control unit is
During operation in the heating mode, when the first output set value is selected, the control of the heating operation based on the burnt information is performed, while the second output set value is selected. Control of the heating operation based on the burnt information is prohibited and the heating operation is continued.
When the first output set value is selected, an elapsed time until the output voltage reaches a predetermined fourth output voltage value set to be equal to or lower than the third output voltage value from the first output voltage value. A control method for an induction heating cooker, comprising: a step of prohibiting control of a heating operation based on the burn information and continuing the heating operation when the burn detection unit detects that the value is less than a predetermined determination value.
When the control unit is operating in the heating mode, and the output set value is changed from the second output set value to the first output set value, the control of the heating operation based on the burn information is executed. The method of controlling an induction heating cooker according to claim 5, further comprising:
The induction heating cooker includes a heating start key that is an operation switch,
When the heating mode is selected and the heating start key is operated, the control unit sets the output set value to a first output set value that is smaller than a predetermined maximum output set value and larger than a predetermined minimum output set value. The method of controlling an induction heating cooker according to claim 5 or 6, further comprising a step of performing a heating operation in the heating mode.
When the controller starts heating, if the output voltage is greater than or equal to a predetermined fifth output voltage value set greater than the first output voltage value and less than or equal to the second output voltage value, The method of controlling an induction heating cooker according to any one of claims 5 to 7, further comprising a step of performing a heating operation in the heating operation mode in which the control of the heating operation based on is prohibited.