JP2020126750A - Induction heating cooker - Google Patents

Abstract

To provide an induction heating cooker capable of providing a preheat completion notification time for notifying preheat completion according to a result of a determined oil amount and making fry cooking easy to use by quickly notifying that preheating is complete without giving extra heating time for the oil amount in a pan.SOLUTION: The induction heating cooker is configured to: control an inverter so that a pan bottom temperature becomes a second temperature higher than a set temperature; determine an oil amount in a pan based on a degree of rise in the pan bottom temperature until it reaches the second temperature; determine a control temperature and a preheat completion notification time based on a combination of the determined oil amount and the set temperature; control the inverter so that the pan bottom temperature converges to the control temperature; and notify completion of preheating when the preheating completion notification time elapses after the pan bottom temperature has converged to the control temperature.SELECTED DRAWING: Figure 6

Description

The present invention relates to an induction heating cooker in which a pan bottom temperature of a pan placed on a top plate is detected by an infrared sensor and a heating power is controlled so as to reach a set oil temperature.

As an induction heating cooker that performs preheating so that the temperature of oil becomes an appropriate temperature and notifies in advance of the completion of preheating, the one described in Patent Document 1 is known. For example, in the abstract of this document, "preheating completion notification time (La) is adjusted according to the material and shape of the pot to be heated, and the heating environment due to the difference in the amount of oil, the temperature at the start of heating, and the oil temperature. Based on the determined preheating completion notification time (La), the time point traced back by a certain set time is set as the preheating completion prior notification point (B), so that the preheating completion notification time (La) can be accurately adjusted according to various heating environments. It is possible to give advance notice of the completion of preheating."

Further, in claim 1 of Patent Document 1, the preheating completion notification time is determined by obtaining a maximum temperature reaching point which is an inflection point where the temperature of the object to be heated changes from rising to falling, and the determined time is It is described that the time point of going back is the preheating completion advance notification point.

JP2012-252883A

As described above, in Patent Document 1, regardless of the amount of oil, the preheating completion notification time (La) is determined starting from the highest temperature reaching point on the bottom surface of the object to be heated (pot). On the other hand, Patent Document 1 does not consider that the time taken for the temperature of the object to be heated (pot) to converge from the maximum temperature to the control temperature is affected by various conditions such as the amount of oil and the material of the pot.

In Patent Document 1, control is performed to lower the temperature of the object to be heated after the maximum temperature is reached, but normally, when lowering the temperature of the object to be heated, heating is stopped or weakened. However, the length of time it takes for the bottom surface temperature of the object to be heated to drop from the maximum temperature to the control temperature varies depending on the heating environment such as the amount of oil and the set temperature. In the method of Patent Document 1 that determines the preheating completion notification time (La) as the starting point, an error is likely to occur between the time when the object to be heated converges to the control temperature and the time when the oil temperature converges to the set temperature. That is, in the induction heating cooker of Patent Document 1, there is a situation in which the actual oil temperature does not reach the set temperature, although the completion of preheating is notified when the object to be heated reaches the control temperature. sell.

Therefore, in the present invention, the time until the oil temperature converges to the set temperature is usually short for a small amount of oil and long for a large amount of oil. It is an object of the present invention to provide an induction heating cooker capable of notifying completion of preheating at an appropriate timing.

The present invention has been made to solve the above problems, and is provided on the upper surface of the main body, a top plate on which a pan containing oil is mounted, and below the top plate, the pan is induction-heated. A heating coil, an inverter that supplies power to the heating coil, an infrared sensor that detects the pot bottom temperature based on infrared rays radiated from the pot bottom of the pot, an input unit that inputs the set temperature of the oil, and A pan bottom temperature, and a controller for controlling the electric power supplied to the heating coil by the inverter based on the set temperature, the controller having a second temperature at which the pan bottom temperature is higher than the set temperature. The inverter is controlled so that the amount of oil in the pot is determined based on the degree of increase in the pot bottom temperature until the second temperature is reached, and the combination of the determined oil amount and the set temperature is determined. Based on the control temperature and preheating completion notification time, controlling the inverter so that the pan bottom temperature converges to the control temperature, after the pan bottom temperature converges to the control temperature, the preheating completion notification time. The induction heating cooker notifies the completion of preheating when the time has passed.

According to the induction heating cooker of the present invention, it is possible to notify the completion of preheating at an appropriate timing according to the amount of oil when cooking fried food.

The external appearance perspective view of the induction heating cooking appliance of one Example. The top view except the top plate of the induction heating cooker. FIG. 3 is a block diagram showing a configuration mainly including left and right heating coils. Explanatory drawing of a reflection type photo interrupter. Explanatory drawing of an upper surface operation part and an upper surface display part. The flowchart explaining operation|movement of an induction heating cooking appliance. Explanatory drawing of the data table of amount determination time and oil amount. Explanatory drawing of the data table of the control temperature determined by the set temperature and the oil amount. Explanatory drawing of data table of preheating completion notification time determined by set temperature and oil amount Explanatory drawing explaining the relationship between the detection temperature of an infrared sensor, and the temperature of oil.

An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is an external perspective view of an induction heating cooker according to an embodiment of the present invention. In FIG. 1, a top plate 2 is horizontally arranged on the upper surface of a main body 1 of the induction heating cooker.

The top plate 2 is made of heat-resistant glass and has a thickness of about 4 mm, on which a cooking container such as a pot 30 made of a magnetic material such as iron or a non-magnetic material such as aluminum is placed.

Below the top plate 2, heating units are provided on the left, right and center rear parts of the upper part of the main body 1. The heating coils 3 formed in an annular shape are respectively arranged in the left and right heating parts, and the pan 30 and the like mounted on the top plate 2 are induction-heated. An example of the heating coil 3 is shown as the heating portion after the center, but a radiant heater may be used.

An upper surface operation unit 7 (7a, 7b, 7c) corresponding to each heating coil 3 is provided on the upper surface on the front surface side of the top plate 2 to set and operate the energized state of the heating coil 3. Further, an upper surface display unit 8 (8a, 8b, 8c) is provided near the upper surface operation unit 7 corresponding to each upper surface operation unit 7a, 7b, 7c, and displays the energization state of each heating coil 3 and the like. To do. The upper surface operation unit 7 and the upper surface display unit 8 form an input unit 70, and the input unit 70 sets the temperature of the pot 30 to be heated.

The upper surface operation unit 7a inputs the heating power of the heating coil 3 on the right side of the main body 1, the upper surface operation unit 7b inputs the heating power of the heating coil 3 on the center rear portion of the main body 1, and the upper surface operation unit 7c inputs the heating power on the left side of the main body 1. The heating power of the heating coil 3 is input.

An intake port 4 that opens upward is provided on the right side of the rear part of the main body 1, and a cooling air that has been taken in from the intake port 4 by the fan (not shown) provided inside the main body 1 inside the main body 1 is provided. A control board (not shown) provided on the board, a heating coil 3 and the like are caused to flow to cool. The intake port 4 may be provided on the front surface or the lower surface of the main body 1. Further, on the left side of the rear portion of the main body 1, an exhaust port 5 for exhausting cooling air that has cooled the inside of the main body 1 is provided.

A grill heater 6 for grilling fish, pizza, etc. is provided on the left side of the front surface of the main body 1. The grill heater 6 has a box shape with an opened front surface, and a sheath heater or the like is provided inside the cooking chamber. A heating element and a grill thermistor (not shown) for detecting the internal temperature are provided, and the front surface is closed by a grill door 6b to which a handle 6a is attached. The grill door 6b has a saucer attached to the back side thereof, and is stored in the cooking cabinet so that it can be freely taken in and out through the front opening, and cooking ingredients such as fish and pizza are placed on the grill placed on the saucer. To do.

A main power switch 9 for supplying power to the main body 1 and a front operating section 10 for inputting cooking conditions and the like of the grill heater 6 are provided on the right front portion of the main body 1.

FIG. 2 is a top view of the induction heating cooker with the top plate 2 removed, and FIG. 3 is a block diagram showing a configuration mainly including left and right heating coils of the induction heating cooker.

The heating coils 3 arranged on the left and right sides are composed of an inner heating coil 3a having an annular shape and an outer heating coil 3c having an annular gap 3b provided on the outer side thereof. The reason for providing the gap 3b in the heating coil 3 is to disperse the magnetic flux generated in the inner heating coil 3a and the outer heating coil 3c to make the temperature of the pan 30 uniform. Although each heating coil 3 is configured to have the gap 3b, the present invention is not limited to this. For example, the inner heating coil 3a and the outer heating coil 3c may be wound without any gap to form the heating coil 3 having no gap 3b.

The heating coil 3 is installed on the coil base 13 as shown in FIG. Further, the gap spacers 14 are provided on the outer periphery of the coil base 13 at appropriate intervals, and the coil base 13 is biased in the direction of the top plate 2 by a plurality of springs (not shown). Is substantially parallel to the top plate 2, and the gap between the pan 30 placed on the top plate 2 and the heating coil 3 is kept constant.

The heating coil 3 employs a litz wire in order to suppress the skin effect, and a voltage of several hundreds of V is applied at a high frequency of several tens of kHz by an inverter 100 described later to apply a high frequency magnetic field to the pan 30. Eddy current is generated in the pan 30 to heat the pan 30 by self-heating.

An inner temperature sensor 15a composed of a thermistor is provided in close contact with the lower surface of the top plate 2 near the center of the heating coils 3 arranged on the left and right, and a pan placed above the heating coil 3 is provided. The temperature of 30 is detected via the top plate 2. Further, the gap 3b of the heating coil 3 is provided with outer temperature sensors 15b, 15c, 15d formed of a thermistor at equal distances from the center of the heating coil 3, and the outer temperature sensors 15b, 15c, 15d are in close contact with the lower surface of the top plate 2 to heat them. The temperature of the pan 30 placed above the coil 3 is detected. Although the outside temperature sensors 15b, 15c, and 15d are provided in the gap 3b of the heating coil 3, the present invention is not limited to this. For example, the configuration may be provided near the outer circumference of the outer heating coil 3c or near the outer circumference of the heating coil 3 in which the inner heating coil 3a and the outer heating coil 3c are wound without a gap 3b. Further, the outside temperature sensors 15b, 15c, 15d are not limited to three, and may be one or two, or three or more.

An infrared sensor 17 that receives infrared rays emitted from the bottom surface of the pot 30 through the top plate 2 and detects the temperature from the energy of the received infrared rays is provided below the gap 3b between the heating coils 3 arranged on the left and right. Has been. The infrared sensor 17 is a sensor that uses a thermal detection element and detects infrared rays emitted from the pan 30. Further, the infrared sensor 17 is provided with a lens, a light guide tube and the like (not shown) for limiting the viewing angle of infrared rays to be detected.

In the gap 3b between the heating coils 3 arranged on the left and right, a reflection type photo interrupter 18 is provided at a position close to the infrared sensor 17 and away from the lower surface of the top plate 2. FIG. 4 is a diagram illustrating the reflective photo interrupter 18. As shown in the figure, in the reflection type photo interrupter 18, an infrared LED 18a as an infrared light emitting element and an infrared phototransistor 18b as an infrared light receiving element are arranged in the same plastic member and molded 18c. A lens is made of plastic on the light emitting surface of the infrared LED 18a, and a narrow beam irradiates infrared light near 930 nm upward. On the light receiving surface of the infrared phototransistor 18b, a lens is formed of plastic that blocks visible light, and the infrared light reflected by the object (bottom of the pan) of the previously irradiated infrared light is received at a narrow viewing angle, and the amount of light received Output a current proportional to. From the output of the reflection type photo interrupter 18, the reflectance measuring circuit 19 measures the reflectance of the bottom surface of the pot 30 placed on the top plate 2. Most of the infrared light of the infrared LED 18a near 930 nm passes through the top plate 2, but part of the infrared light is reflected by the top plate 2. This is because the transmittance of the top plate 2 is 90% at the wavelength of 930 nm, and the remaining 10% of infrared light is reflected. Therefore, the reflectance measuring circuit 19 measures in advance the relationship with the output of the reflective photointerrupter 18 when the pot 30 (metal plate) having a known reflectance is placed on the top plate 2, and this relationship is stored in a table. The data or the coefficient value of the approximate expression is stored, and the reflectance is calculated.

FIG. 5 is a diagram for explaining the upper surface operation unit 7a and the upper surface display unit 8a of the input unit 70. The contents of the upper surface operation unit 7c and the upper surface display unit 8c are the same as the contents of the upper surface operation unit 7a and the upper surface display unit 8a, and thus description thereof will be omitted. The upper surface display portion 8a is divided into a display portion 81a and a display portion 81b, and the display portion 81a displays the heat power input by the heat power setting key 72, the cooking menu input by the menu setting key 71, and the like. The display unit 81b informs the user of the timing of feeding the ingredients when the temperature of the pan 30 reaches an appropriate temperature by preheating the pan 30 in the "fried food" or "steak" menu set by the menu setting key 71. It is possible to display "preheating" and "appropriate temperature" so that it can be performed.

The heat power that can be set with the heat power setting key 72 is divided into four stages of "melt heat" key 72a "low heat" key 72b "medium heat" key 72c "high heat" key 72d, so that the required heat power can be input by one operation. Keys are provided individually according to the heating power.

As a guideline for the thermal power to be set, a maximum of 12 levels of thermal power are provided, and the relationship between each thermal power and power consumption is 100 W for the "1" stage, 200 W for the "2" stage, and 300 W for the "3" stage. , "4" stage is 400W, "5" stage is 500W, "6" stage is 800W, "7" stage is 1.1kW, "8" stage is 1.4kW, "9" stage is 1.6kW, " The 10" stage is 2 kW, the "11" stage is 2.5 kW, and the "12" stage is 3 kW. The number of each stage is a number displayed on the display unit 81a as a measure of the heat power. In addition, the relationship between the four-stage thermal power display and the 12-stage display is "1" for "low heat", "2" "3" "4" "5" for "low heat", and "6" "7" for "medium heat". "8" and "high heat" are "9" "10" "11" "12".

When inputting a thermal power that cannot be input with the thermal power setting key 72, for example, a thermal power of "9", first set the thermal power to "7" with the "medium heat" key 72c, and then with the thermal power adjustment UP key. When 73b is pressed twice, the number showing the heat power displayed on the display unit 81a is changed from "7" to "8", "8" to "9", and the heat power becomes high heat "9". Indicates. By the way, when the arrow adjustment DOWN key 73a is pressed next, the heating power can be lowered from "9" to "8".

The menu setting key 71 is used to set "cooking rice", "fried food", "boiled water", "stir-fried food", "steak", etc. for automatic cooking. A menu is displayed on 81a, and each time the menu setting key 71 is pressed, the menu is switched and displayed. This selects the menu to use.

When "fried food" is selected with the menu setting key 71, it is necessary to set the oil temperature next, and in that case, the arrow adjustment key 73 can be operated to set the temperature in seven stages from 140°C to 200°C. .. For example, when the menu setting key 71 is used to set the fried food and then the arrow adjustment key 73 is used to set the oil temperature to 180° C., the display section 81a displays the number "180" and the "fried food" as shown in FIG. Is displayed.

Reference numeral 74 is an off/start key for starting and stopping cooking.

Next, the heating control of the pan 30 by the left and right heating coils 3 will be briefly described with reference to FIG. The description of the control of the grill heater 6 and the control of the heating coil 3 at the central rear portion of the main body 1 is omitted.

The control device 118 receives the output signals of the heating power from the menu setting key 71 and the heating power setting key 72 and the temperature from the arrow adjustment key 73 of the upper surface operation unit 7a. Further, the control device 118 receives output signals from the inner temperature sensor 15a provided near the heating coil 3 and the outer temperature sensors 15b, 15c, 15d.

Regarding the output of the infrared sensor 17 provided in the heating coil 3, the output of the infrared sensor 17 is different due to the difference in the infrared emissivity of the pan 30 even though the pan bottom temperature is the same. Therefore, in order to correct the output due to the difference in the emissivity of the pot 30, the reflectance measuring circuit 19 measures the reflectance of the bottom of the pot 30 from the output of the reflective photointerrupter 18, and the controller 118 outputs the output of the infrared sensor 17. The temperature of the pot 30 is detected by correcting the obtained reflectance. Then, the control device 118 controls the inverter 100 based on the output of the input unit 70 and the output of the infrared sensor 17 and the output signal of the temperature sensor 15, controls the high frequency current flowing through the heating coil 3, and supplies the electric power to the heating coil 3. To control the heating of the pan 30.

The details of the operation of the induction heating cooker configured as above when cooking fried food will be described with reference to FIGS. 6 to 10.

When controlling the electric power supplied to the heating coil 3 while detecting the pan bottom temperature of the pan 30 containing oil during cooking of deep-fried food and maintaining the oil temperature at a constant set temperature T _S , the pan 30 There is a temperature difference between the pan bottom temperature of the pan 30 detected by the infrared sensor 17 and the actual oil temperature according to the amount of oil put in the pan, and the pan bottom temperature of the pan 30 detected by the infrared sensor 17 also according to the set temperature. There is a problem that a temperature difference occurs in the actual oil temperature.

Therefore, in the present embodiment, the oil amount is determined according to the degree of increase in the pan bottom temperature detected by the infrared sensor 17, and the control temperature that is the target temperature of the pan bottom temperature is determined according to the combination of the determined oil amount and the set temperature. By correcting T _C , heating is performed so that the oil temperature substantially matches the set temperature T _S. The overall flow will be described below with reference to the flowchart of FIG. 6 and will be described in more detail with reference to the tables of FIGS. 7 to 9 and the specific example of FIG.

First, the tables in FIGS. 7 to 9 will be described.

FIG. 7 is an example of a table for determining the oil amount Q according to the degree of increase in the pot bottom temperature. This table monitors the temperature detected by the infrared sensor 17 when the oil-filled pot 30 is heated, and the time when the detected temperature passes a section of a specific detected temperature (hereinafter referred to as the passage time t _P ) and the passage time t _It shows the relationship of the oil amount Q according to _P. Here, the passage time t _P is divided into four amount determination times t _J1 , t _J2 , t _J3 , and t _J4 . For example, the amount determination time t _J1 is 20 seconds or less, t _J2 is 20 seconds or more and less than 25 seconds, t _J3 is 25 seconds or more and less than 30 seconds, and t ₄ is 30 seconds or more and less than 60 seconds. Then, the oil amount Q is determined according to which amount determination time t _J corresponds to. When the amount determined time _{t J} and 4 section of the oil amount Q is determined, for example, _{Q A} is less than 200 g 400 g, _{Q B} is less than 400 g 600 g, _{Q C} is less than 600 g 800 g, _{Q D} Are four categories of 800 g or more.

FIG. 8 is an example of a table for obtaining the control temperature T _C from the combination of the oil amount Q determined based on the amount determination time t _J and the set temperature T _S set by the user using the input unit 70. When the control temperature T _C is obtained from this table, the control device 118 controls the electric power supplied from the inverter 100 to the heating coil 3 so that the pan bottom temperature detected by the infrared sensor 17 becomes the control temperature T _C. The control temperature T _C is set to a higher temperature as the oil amount Q is larger. This is because the temperature difference between the pan bottom temperature and the oil temperature is generally in proportion to the oil amount, and therefore the actual oil temperature becomes lower than the pan bottom temperature as the oil amount increases.

Further, FIG. 9 controls the oil amount Q determined based on the amount determination time t _J , the set temperature T _S set by the user using the input unit 70, and the like. The preheating completion notification time t _A is set to be longer as the oil amount Q is larger. This is because when the thermal power control is the same, the time required to raise the oil temperature to the set temperature T _S is approximately proportional to the oil amount.

Next, the flow of control when cooking "fried food" will be described based on the flowchart of FIG. Before starting this process, the user puts the amount of oil in the frying pan 30 according to the content of the cooking, and places it in the center of the heating coil 3 on the right side of the main body 1.

First, in step S1, the user turns on the main power switch 9.

Next, in step S2, the user operates the menu setting key 71 of the upper surface operation unit 7a while viewing the display unit 81a to display "fried food" on the display unit 81a, and then operates the arrow adjustment key 73. Then, the set temperature T _S (140° C. to 200° C. selectable in steps of 10° C.) is input. In the description below, it is assumed that the user has set the set temperature T _S to 180° C. When this step is completed, the set temperature T _S “180” and the menu “fried food” are displayed on the display unit 81a, as illustrated in FIG.

Then, in step S3, when the user operates the switching-start key 74, the control device 118, regardless of the set temperature T _S, the pan bottom temperature detected by the infrared sensor 17, the upper limit 200 ° C. of the set temperature T _S The pot 30 is heated with a constant heating power (for example, 1.5 kW) until the higher second temperature T ₂ (for example, 220° C.) is reached. As a result, both the pan bottom temperature and the oil temperature start to rise.

Steps S4 to S10 are steps in which the control device 118 determines the oil amount Q in the pan 30, and after the pan bottom temperature detected by the infrared sensor 17 reaches the first temperature T ₁ (for example, 200° C.). In this step, the control device 118 measures the passage time t _P until reaching the second temperature T ₂ (for example, 220° C.), and determines the oil amount Q according to the passage time t _P. The first temperature T ₁ and the second temperature T ₂ are fixed temperatures that are set regardless of the set temperature T _S.

First, in step S4, the control device 118 monitors with the infrared sensor 17 whether the pot bottom temperature has reached the first temperature T ₁ . Then, when the detected temperature reaches the first temperature T ₁ , the process proceeds to step S5 and the measurement of the passage time t _P is started.

In step S6, the control device 118 monitors with the infrared sensor 17 whether the pot bottom temperature has reached the second temperature T ₂ . Then, if the second temperature T ₂ is not reached, the process proceeds to step S7, and if the second temperature T ₂ is reached, the process proceeds to step S9.

In step S7, the control device 118 monitors whether or not the passing time t _P during measurement has passed a predetermined waiting time t _W (for example, 60 seconds). Then, the process returns to step S6 before the elapse of the waiting time t _W , and proceeds to step S8 after the elapse. The standby time t _W is the maximum time required to increase the temperature from the first temperature T ₁ to the second temperature T ₂ when the maximum amount of oil that can be heated by the induction cooker (for example, 800 g) is heated. It's a corresponding time.

Step S8, a process to continue processing even if the pan bottom temperature did not reach the second temperature T _2, in this case, the control device 118, the largest segment of the oil amount Q Q Set to _D.

In step S9, when the pot bottom temperature rises from the first temperature T ₁ to the second temperature T ₂ before the waiting time t _W has elapsed, the control device 118 determines the time required for that as the passage time t _P.

In step S10, the control device 118 determines the section of the amount determination time t _J that includes the passage time t _P based on the passage time t _P determined in step S9, and determines the oil amount Q according to each section. judge. The table shown in FIG. 7 is used in this step.

In step S11, the controller 118 sets the control temperature T _C based on the set temperature T _S set in step S2 and the oil amount Q determined in step S10. The table shown in FIG. 8 is used in this step.

In step S12, the control unit 118 sets the set temperature _{T S,} which is set in step S2, the completion of preheating broadcast time _{t A} based on the oil amount Q determined in step S10. The table shown in FIG. 9 is used in this step.

In step S13, the control unit 118, the target temperature of the pan bottom, the second temperature T ₂ set in step S3, switch to control temperature T _C set in step S11, controls the power supplied to heating coil 3 The infrared sensor 17 monitors whether the pan bottom temperature has converged near the control temperature T _C. Then, if it has not converged to the control temperature T _C , step S13 is repeated, and if it reaches the control temperature T _C , the process proceeds to step S14.

In step S14, the control device 118 measures the elapsed time after the pan bottom temperature converges to the control temperature T _C and monitors whether the measured time has passed the preheating completion notification time t _A. Then, if the completion notification time t _A has not elapsed, step S14 is repeated, and if the completion notification time t _A has elapsed, the process proceeds to step S15.

In step S15, the control device 118 notifies the user that the oil temperature in the pan 30 has reached the set temperature T _S , and ends the preheating control. Incidentally, after the end of the preheating control, the control device 118, the pan bottom temperature detected by the infrared sensor 17, so as to maintain the control temperature T _C, controls the electric power supplied to the heating coil 3.

Next, referring to FIG. 10, the cooking temperature of the fried food of the present embodiment will be concretely described by taking the case where the set temperature T _S set by the user is 180° C. and the amount of oil Q in the pan 30 is 300 g as an example. To explain. In FIG. 10, the upper graph is a diagram showing the temporal change of the pan bottom temperature (solid line) detected by the infrared sensor 17 and the oil temperature in the pan 30 (dashed line), and the lower graph is supplied to the heating coil 3. It is a figure which shows the time change of the electric power made into.

When cooking of deep-fried food is started, as shown in the graph below, a predetermined constant power is supplied to the heating coil 3, and the pot bottom temperature rapidly rises to the preset second temperature T ₂ . During this period, the control device 118 measures the length of time (passing time t _P ) until the temperature detected by the infrared sensor 17 rises from the first temperature T ₁ to the second temperature T ₂ . The heating control until reaching the second temperature T ₂ is the same regardless of the set temperature T _S.

When the passage time t _P (for example, 15 seconds) is measured, the control device 118 specifies the amount determination time t _J1 including the passage time t _P (15 seconds) by using the table illustrated in FIG. 7. Further, the oil amount Q _A corresponding to this amount determination time t _J1 is specified. Then, using the tables illustrated in FIGS. 8 and 9, the control temperature T _C (210° C.) and the preheating completion notification time t corresponding to the specified combination of the oil amount Q _A and the set temperature T _S (180° C.). Determine _A (80 seconds).

Then, the control device 118 uses the timing at which the pan bottom temperature detected by the infrared sensor 17 converges to the control temperature T _C (210° C.) as a starting point until the preheating completion notification time t _A (80 seconds) elapses. The electric power supplied to the heating coil 3 is controlled so as to maintain the control temperature T _C (210° C.). As is clear from the upper graph of FIG. 10, the oil temperature rises later than the pot bottom temperature, so when the pot bottom temperature converges to the control temperature T _C (210° C.), the oil temperature is set to the set temperature T _S ( (180° C.) is not reached, and the set temperature T _S is reached when the preheating completion notification time t _A (80 seconds) has elapsed. Therefore, the control device 118 notifies the user of the timing when the oil temperature reaches the set temperature T _S (180° C.) by notifying the preheating completion by using the display unit 81b and the sound after the preheating completion notifying time t _A has elapsed. Can be notified.

Even after the completion of preheating is notified, the control device 118 controls the electric power supplied to the heating coil 3 so that the pot bottom temperature maintains the control temperature T _C (210° C.). As a result, the oil temperature in the pan 30 can also be maintained at the set temperature T _S (180° C.).

As described above, according to the embodiment, the amount of oil in the pan 30 is determined, and the stepwise preheating completion notification time t _A associated with the amount of oil and the set temperature T _S is set. If the time and the amount of oil are large, it can be set to a long time and the preheating completion notification time t _A according to the amount of oil can be set.

In addition, since the preheating completion notification time t _A , which is a fixed time, is set according to the determined amount of oil, heating is performed by displaying information on the product body, voice, or by transferring information from the product body to a mobile terminal such as a smartphone. It is also possible to inform the user at a relatively early stage from the start until the completion of preheating to reach a temperature at which cooking is possible.

In this way, the time required for completion of preheating is notified to the user at the time when the control temperature T _C is reached and the control by the preheating completion notification time t _A starts, and the user is notified to the user at a relatively early stage from the start of heating. It is also possible to convey information.

1 Main Body 2 Top Plate 3 Heating Coil 17 Infrared Sensor 30 Pan 70 Input Unit 118 Control Device t _P Pass Time t _J Amount Determination Time t _A Preheating Completion Notification Time T _S Set Temperature T ₁ First Temperature T ₂ Second Temperature T _C Control temperature Q Oil quantity

Claims (5)

A top plate provided on the upper surface of the main body and equipped with a pan containing oil,
A heating coil provided below the top plate for inductively heating the pan;
An inverter for supplying electric power to the heating coil,
An infrared sensor that detects the temperature of the bottom of the pot based on the infrared radiation emitted from the bottom of the pot,
An input unit for inputting the set temperature of the oil,
A control device for controlling the electric power supplied to the heating coil by the inverter based on the pot bottom temperature and the set temperature;
The control device is
Control the inverter so that the pot bottom temperature becomes a second temperature higher than the set temperature,
Determine the amount of oil in the pot based on the degree of increase in the pot bottom temperature until reaching the second temperature,
Based on the combination of the determined oil amount and the set temperature, determine the control temperature and preheating completion notification time,
Controlling the inverter so that the pot bottom temperature converges to the control temperature,
After the pan bottom temperature has converged to the control temperature, when the preheating completion notification time has elapsed, the preheating completion is notified.
An induction heating cooker characterized by the following. The induction heating cooker according to claim 1,
The induction heating cooker, wherein the degree of rise of the pot bottom temperature is a length of a passage time required for the pot bottom temperature to rise from a preset first temperature to a second temperature. The induction heating cooker according to claim 1,
The induction heating cooker, wherein the control temperature is determined based on a control temperature setting table that defines a control temperature corresponding to a combination of the set temperature and the oil amount. The induction heating cooker according to claim 1,
The induction heating cooker is characterized in that the preheating completion notification time is determined based on a preheating completion notification time setting table that defines a preheating completion notification time corresponding to a combination of the set temperature and the oil amount. The induction heating cooker according to any one of claims 1 to 4,
The lapse of the preheating completion notification time is
An induction heating cooker characterized by being visually or audibly notified via a display unit provided on the main body or a mobile terminal.

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