Method and device for estimating temperature of contents in electric kettle

Abstract

[Problem] To quickly and accurately estimate the constantly changing heating temperature of water or other contents contained in an electric kettle using the temperature of a heater without directly measuring the temperature of the contents. [Solution] A device for contactlessly receiving power from a power supply coil (13) of a power supply base (27) through a power receiving coil (14) of an electric kettle (28) and heating a content (36) through a built-in heater (18), the device comprising: a power supply circuit (19) for supplying power to the heater (18); a temperature sensor (22) that detects the temperature of the heater (18); a control unit (20) that controls the energization of the heater (18); a temperature storage unit (25) that stores the temperature detected by the temperature sensor (22) via the control unit (20); an estimated temperature coefficient storage unit (29) that stores a predetermined unique estimated temperature coefficient (Ce) of the electric kettle (28); and a temperature estimation unit (26) that estimates the temperature of the content (36) on the basis of the data stored in the temperature storage unit (25) and the temperature estimation coefficient (Ce).

Description

Technical Field

[0001] The present invention relates to a method and device for estimating the temperature of contents in an electric kettle, which accurately estimates the heating temperature of the contents based on a temperature sensor built into a heater of the electric kettle. Background Art

[0002] Previously known Figure 7 The electric kettle shown in Patent Document 1.

[0003] exist Figure 7 In the embodiment, a ring-shaped heater 52 is provided as a heating unit on the outer bottom of a container 51. A temperature sensing element (thermistor) 53 is mounted in its center, pressed against the container 51. This temperature sensing element 53 serves as a part of a temperature detection unit 54, which indirectly detects the temperature of the water in the container 51. When power is supplied to the heater 52 to initiate heating, a temperature gradient detection unit 55 detects the temperature gradient based on the output of the temperature detection unit 54 and stores the detected value in a first storage unit 56 under specified conditions.

[0004] Then, the gradient comparison unit 57 compares the value stored in the first storage unit 56 with the output of the temperature gradient detection unit 55 and outputs a value when the value becomes equal to or less than a predetermined ratio.

[0005] Meanwhile, the temperature comparison unit 58 compares the output of the temperature detection unit 54 with the value stored in the nonvolatile second storage unit 59 and outputs the value when the output of the temperature detection unit 54 is equal to or greater than the stored value. Then, upon obtaining either the output of the gradient comparison unit 57 or the output of the temperature comparison unit 58, the boiling detection unit 60 detects boiling, stops powering the heater 52, and stores the output of the temperature detection unit 54 at that time in the second storage unit 59.

[0006] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Laid-Open No. 3-191925. Summary of the Invention

[0007] The invention described in Patent Document 1 aims to provide an electric kettle capable of detecting boiling. A ring-shaped heater 52 is provided as a heating unit on the outer bottom of a container 51. A temperature sensing element (thermistor) 53 is mounted at its center, pressed against the container 51. Therefore, the temperature detected is at the outer bottom of the container 51. Because the actual temperature characteristics of the water within the container 51 vary depending on the container's thermal resistance, material, heat retention capacity, and volume, the actual water temperature can only be detected indirectly via the temperature sensing unit 54.

[0008] Furthermore, when the heater 52 is energized to start heating, the temperature gradient detection unit 55 detects the temperature gradient based on the output of the temperature detection unit 54 . Therefore, it takes time to detect the actual temperature of the water, and rapid temperature detection is not possible.

[0009] An object of the present invention is to provide a method and apparatus for estimating the temperature of contents in an electric kettle, which can rapidly and accurately estimate the temperature of water or other contents that changes moment by moment during heating.

[0010] The device for estimating the temperature of the contents of an electric kettle of the present invention comprises: The power supply stand 27 has a built-in power supply coil 13; and the electric kettle 28 has a built-in power receiving coil 14. The power receiving coil 14 receives power from the power supply coil 13 in a contactless manner. The device heats the stored contents 36 via the heater 18 provided in the electric kettle 28. The device is characterized by having: a power supply circuit 19 for supplying power to the heater 18; a temperature sensor 22 for detecting the temperature of the heater 18; a control unit 20 coupled to the power supply circuit 19 to control the energization of the heater 18; a temperature storage unit 25 coupled to the control unit 20 and configured to store the temperature detected by the temperature sensor 22 via the control unit 20; a temperature estimation coefficient storage unit 29 for storing a preset unique temperature estimation coefficient Ce of the electric kettle 28; and The temperature estimation unit 26 estimates the temperature of the content 36 based on the data in the temperature storage unit 25 and the temperature estimation coefficient Ce.

[0011] It is characterized in that, regarding the temperature estimation coefficient Ce, when the temperature stored in the temperature storage unit 25 is assumed to be the temperature when the power supply circuit 19 is controlled according to the instruction of the control unit 20 and a pulse voltage is applied to the heater 18 that is repeatedly turned on during the period T11-T21 and turned off during the period T21-T31, the temperature at T21 is To1, the temperature at T31 is Tn1, and the temperature actually detected at T31 by a temperature sensor different from the temperature sensor 22 of the content 36 is Te1, the temperature estimation coefficient Ce is obtained by calculating the following formula.

[0012] Ce=(To1-Tn1) / (To1-Te1) It is characterized in that, regarding the estimated temperature Te of the content 36, when the temperature stored in the temperature storage unit 25 is assumed to be the temperature when the power supply circuit 19 is controlled according to the instruction of the control unit 20 and a pulse voltage is applied to the heater 18 that is repeatedly turned on during the period T1-T2 and turned off during the period T2-T3, the temperature at T2 is To and the temperature at T3 is Tn, the estimated temperature Te of the content 36 is calculated by the temperature estimation unit 26 using the following formula.

[0013] Te=To-(To-Tn) / Ce The temperature estimation unit 26 is characterized in that it includes: a first subtraction circuit 30, which subtracts Tn from the output To of the temperature storage unit 25; a division circuit 31, which divides the calculation output (To-Tn) of the first subtraction circuit 30 by the temperature estimation coefficient Ce to obtain (To-Tn) / Ce; and a second subtraction circuit 32, which subtracts the output (To-Tn) / Ce of the division circuit 31 from the output To of the temperature storage unit 25 to calculate the estimated temperature Te of the content 36 = To-(To-Tn) / Ce.

[0014] It is characterized in that it also has a gyro sensor 21, which is arranged at the approximate rotation center position of the electric kettle 28, and outputs the rotation angle and rotation direction of the electric kettle 28. The gyro sensor 21 is coupled to the control unit 20, and the temperature set according to the output of the gyro sensor 21 is stored in the temperature setting unit 24. The power supply of the power supply circuit 19 is controlled by the control unit 20 to make the temperature of the content 36 consistent with the set temperature of the temperature setting unit 24.

[0015] The electric kettle 28 is characterized in that it further includes a gyro sensor 21, which is provided at a substantially rotation center position of the electric kettle 28 and outputs the rotation angle and rotation direction of the electric kettle 28. The gyro sensor 21 is coupled to the control unit 20, and the temperature set according to the output of the gyro sensor 21 is stored in the temperature setting unit 24. The control unit 20 controls the power supply of the power supply circuit 19 so that the temperature of the content 36 is consistent with the set temperature of the temperature setting unit 24. A vibration motor 43 is provided inside the electric kettle 28 and coupled to the control unit 20. When the temperature set by the gyro sensor 21 and stored in the temperature setting unit 24 reaches a specified value, the vibration motor 43 is driven by a signal from the control unit 20, causing the electric kettle 28 to vibrate for notification.

[0016] The method for estimating the temperature of the contents of an electric kettle according to the present invention is characterized by using a device comprising: A power supply stand 27 having a built-in power supply coil 13; and an electric kettle 28 having a built-in power receiving coil 14, the power receiving coil 14 receiving power from the power supply coil 13 in a contactless manner. The device heats the stored contents 36 via a heater 18 provided in the electric kettle 28. The device comprises: a power supply circuit 19 that supplies power to the heater 18; a temperature sensor 22 that detects the temperature of the heater 18; a control unit 20 coupled to the power supply circuit 19 and controlling the energization of the heater 18; a temperature storage unit 25 coupled to the control unit 20 and storing the temperature detected by the temperature sensor 22 via the control unit 20; a temperature estimation coefficient storage unit 29 that stores a preset unique temperature estimation coefficient Ce of the electric kettle 28; and a temperature estimation unit 26 that estimates the temperature of the contents 36 based on data in the temperature storage unit 25 and the temperature estimation coefficient Ce. The method includes: a step of controlling the power supply circuit 19 according to a command from the control unit 20 to apply a pulse voltage to the heater 18, which is repeatedly turned on during a period T11 to T21 and turned off during a period T21 to T31; a step of obtaining the temperature To1 at time T21 and the temperature Tn1 at time T31 by the temperature sensor 22; A step of determining the temperature Te1 actually detected by a temperature sensor different from the temperature sensor 22 of the content 36 at the time T31; a step of calculating the temperature estimation coefficient Ce inherent to the electric kettle 28 by Ce=(To1-Tn1) / (To1-Te1); a step of controlling the power supply circuit 19 according to a command from the control unit 20 to apply a pulse voltage to the heater 18, which is repeatedly turned on during a period T1-T2 and turned off during a period T2-T3; a step of storing the temperature To at time T2 and the temperature Tn at time T3 measured by the temperature sensor 22 in the temperature storage unit 25; and A step of calculating Te=To-(To-Tn) / Ce based on the preset temperature estimation coefficient Ce, To, and Tn to obtain the temperature Te of the content 36 .

[0017] According to the invention of claim 1, The device comprises: a power supply stand having a built-in power supply coil; and an electric kettle having a built-in power receiving coil, the power receiving coil receiving power from the power supply coil in a contactless manner, and heating the stored contents using a heater provided in the electric kettle. a power supply circuit that supplies power to the heater; a temperature sensor that detects the temperature of the heater; a control unit coupled to the power supply circuit and configured to control energization of the heater; a temperature storage unit, coupled to the control unit, and configured to store the temperature detected by the temperature sensor via the control unit; a temperature estimation coefficient storage unit storing a preset unique temperature estimation coefficient Ce of the electric kettle; and The temperature estimation unit estimates the temperature of the contents based on the data of the temperature storage unit and the temperature estimation coefficient Ce. Therefore, there is no need to use a temperature sensor that directly measures the temperature of the contents. Instead, by presetting and registering the inherent temperature estimation coefficient Ce of the electric kettle, the temperature of the contents can be estimated with high precision and quickly based on the measurement value of the temperature sensor that measures the temperature of the heater.

[0018] According to the invention of claim 2, Regarding the temperature estimation coefficient Ce, when the pulse voltage repeatedly turned on during T11-T21 and turned off during T21-T31 is applied to the heater by controlling the power supply circuit according to the instruction of the control unit, the temperature stored in the temperature storage unit, the temperature at T21 is To1, the temperature at T31 is Tn1, and the temperature actually detected by a temperature sensor different from the temperature sensor of the content at T31 is Te1, the calculation is performed. Ce=(To1-Tn1) / (To1-Te1) By obtaining the temperature estimation coefficient Ce, it is possible to easily obtain the temperature estimation coefficient Ce inherent to the electric kettle.

[0019] According to the invention of claim 3, When the power supply circuit is controlled according to the instruction of the control unit and a pulse voltage is applied to the heater repeatedly between T1 and T2 and between T2 and T3, the temperature stored in the temperature storage unit is To and the temperature at T3 is Tn. Te=To-(To-Tn) / Ce Therefore, the estimated temperature Te of the content can be easily and accurately obtained.

[0020] According to the invention of claim 4, The temperature estimation unit includes: a first subtraction circuit that subtracts Tn from the output To of the temperature storage unit; a division circuit that divides the calculation output (To-Tn) of the first subtraction circuit by the temperature estimation coefficient Ce to calculate (To-Tn) / Ce; and a second subtraction circuit that subtracts the output (To-Tn) / Ce of the division circuit from the output To of the temperature storage unit to calculate the estimated temperature Te=To-(To-Tn) / Ce of the contents. Therefore, the temperature estimation unit can be formed by a simple subtraction circuit and a division circuit.

[0021] According to the invention of claim 5, The electric kettle is also provided with a gyro sensor, which is arranged at the approximate rotation center position of the electric kettle and outputs the rotation angle and rotation direction of the electric kettle. The gyro sensor is coupled to the control unit, and the temperature set according to the output of the gyro sensor is stored in the temperature setting unit. The power supply of the power supply circuit is controlled by the control unit to make the temperature of the contents consistent with the set temperature of the temperature setting unit. Therefore, the set temperature can be set according to the rotation angle and rotation direction of the electric kettle.

[0022] According to the invention of claim 6, The electric kettle is also provided with a gyro sensor, which is arranged at the approximate rotation center position of the electric kettle and outputs the rotation angle and rotation direction of the electric kettle. The gyro sensor is coupled to the control unit, and the temperature set according to the output of the gyro sensor is stored in the temperature setting unit. The power supply of the power supply circuit is controlled by the control unit to make the temperature of the contents consistent with the set temperature of the temperature setting unit. A vibration motor is provided inside the electric kettle and coupled to the control unit. When the set temperature based on the gyro sensor reaches a specified value, the vibration motor is driven by the signal of the control unit, causing the electric kettle to vibrate for notification, so that the set temperature can be felt by touch.

[0023] According to the invention of claim 7, The method uses a device comprising: a power supply stand having a built-in power supply coil; and an electric kettle having a built-in power receiving coil, the power receiving coil receiving power from the power supply coil in a contactless manner. The device heats stored contents using a heater provided in the electric kettle, and comprises: a power supply circuit that supplies power to the heater; a temperature sensor that detects the temperature of the heater; a control unit coupled to the power supply circuit and controlling energization of the heater; a temperature storage unit coupled to the control unit and storing the temperature detected by the temperature sensor via the control unit; a temperature estimation coefficient storage unit that stores a preset inherent temperature estimation coefficient Ce of the electric kettle; and a temperature estimation unit that estimates the temperature of the contents based on data in the temperature storage unit and the temperature estimation coefficient Ce. The method includes: a step of controlling the power supply circuit according to a command from the control unit to apply a pulse voltage to the heater that is repeatedly turned on during a period T11 to T21 and turned off during a period T21 to T31; a step of obtaining the temperature To1 at time T21 and the temperature Tn1 at time T31 by the temperature sensor; a step of determining a temperature Te1 actually detected by a temperature sensor different from the temperature sensor of the contents at the time T31; a step of calculating the temperature estimation coefficient Ce inherent to the electric kettle by Ce=(To1-Tn1) / (To1-Te1); a step of controlling the power supply circuit according to a command from the control unit to apply a pulse voltage to the heater that is repeatedly turned on during a period T1-T2 and turned off during a period T2-T3; a step of storing the temperature To at time T2 and the temperature Tn at time T3 measured by the temperature sensor in the temperature storage unit; and The step of calculating Te=To-(To-Tn) / Ce based on the preset temperature estimation coefficient Ce, To, and Tn to obtain the temperature Te of the content enables estimating the content temperature based on the inherent characteristics of the electric kettle. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a cross-sectional view showing a method and apparatus for estimating the temperature of contents in an electric kettle according to a first embodiment of the present invention.

[0025] Figure 2 This is a circuit diagram showing a first embodiment of a method and apparatus for estimating the temperature of contents in an electric kettle according to the present invention.

[0026] Figure 3 yes Figure 21 is a block diagram of the temperature estimation unit 26 in FIG.

[0027] Figure 4 This is a flow chart of a method and apparatus for estimating the temperature of contents in an electric kettle according to the present invention.

[0028] Figure 5 This is a flow chart of a method for estimating the temperature of contents in an electric kettle and a device thereof during liquid temperature estimation according to the present invention.

[0029] Figure 6 This is a waveform diagram of the method for estimating the temperature of the contents of an electric kettle and the device thereof according to the present invention.

[0030] Figure 7 This is an illustration of a conventional electric kettle.

[0031] (Explanation of symbols) 7: Display unit; 8: Wireless terminal; 9: Wireless communication unit; 10: AC power supply; 11: Rectifier circuit; 12: Inverter circuit; 13: Power supply coil; 14: Power receiving coil; 15: Resonant capacitor; 16: Rectifier circuit; 17: Smoothing capacitor; 18: Heater; 19: Power supply circuit; 20: Control unit; 21: Gyro sensor; 22: Temperature sensor; 23: Non-volatile memory; 24: Temperature setting unit; 25: Temperature storage unit; 26: Temperature estimation unit; 27: Power supply stand; 28: Electric kettle; 29: Temperature estimation coefficient storage unit; 30: First subtraction circuit; 31: Division circuit; 32: Second subtraction circuit; 33: First temperature signal input terminal ; 34: Second temperature signal input terminal; 35: Output terminal; 36: Contents; 37: Electric kettle body; 38a: Inner wall portion; 38b: Outer wall portion; 39: Vacuum insulation portion; 40: External packaging material; 41: Pad; 42: Lid; 43: Vibration motor; 44: Bottom; 45: Substrate holder; 46: Substrate holder cover; 47: Wiring substrate; 48: Spring plate; 49: Mica board; 50: Inner bottom cover; 51: Container; 52: Heater; 53: Temperature sensing element; 54: Temperature detection unit; 55: Temperature gradient detection unit; 56: First storage unit; 57: Gradient comparison unit; 58: Temperature comparison unit; 59: Second storage unit; 60: Boiling detection unit. DETAILED DESCRIPTION

[0032] The device for estimating the temperature of the contents of an electric kettle of the present invention comprises: The device includes a power supply base 27 having a power supply coil 13 built therein; and an electric kettle 28 having a power receiving coil 14 built therein. The power receiving coil 14 receives power from the power supply coil 13 in a contactless manner. The device heats the stored contents 36 via a heater 18 provided in the electric kettle 28, including: a power supply circuit 19 for supplying power to the heater 18; a temperature sensor 22 for detecting the temperature of the heater 18; a control unit 20 coupled to the power supply circuit 19 to control the energization of the heater 18; a temperature storage unit 25 coupled to the control unit 20 and configured to store the temperature detected by the temperature sensor 22 via the control unit 20; a temperature estimation coefficient storage unit 29 for storing a preset unique temperature estimation coefficient Ce of the electric kettle 28; and The temperature estimation unit 26 estimates the temperature of the content 36 based on the data in the temperature storage unit 25 and the temperature estimation coefficient Ce.

[0033] Regarding the temperature estimation coefficient Ce, when the power supply circuit 19 is controlled according to the instruction of the control unit 20 and a pulse voltage is applied to the heater 18 which is repeatedly turned on during the period T11-T21 and turned off during the period T21-T31, the temperature stored in the temperature storage unit 25 is To1, the temperature at T31 is Tn1, and the temperature actually detected by a temperature sensor different from the temperature sensor 22 of the content 36 at T31 is Te1, the temperature estimation coefficient Ce is obtained by calculating the following formula.

[0034] Ce=(To1-Tn1) / (To1-Te1) When the temperature stored in the temperature storage unit 25 is assumed to be To and the temperature at T3 is Tn when the power supply circuit 19 is controlled according to the instruction of the control unit 20 and a pulse voltage is applied to the heater 18 repeatedly turned on during T1-T2 and turned off during T2-T3, the temperature at T2 is To and the temperature at T3 is Tn, the estimated temperature Te of the content 36 is calculated by the temperature estimation unit 26 using the following formula.

[0035] Te=To-(To-Tn) / Ce The temperature estimation unit 26 includes: a first subtraction circuit 30 that subtracts Tn from the output To of the temperature storage unit 25; a division circuit 31 that divides the calculation output (To-Tn) of the first subtraction circuit 30 by the temperature estimation coefficient Ce to obtain (To-Tn) / Ce; and a second subtraction circuit 32 that subtracts the output (To-Tn) / Ce of the division circuit 31 from the output To of the temperature storage unit 25 to calculate the estimated temperature Te of the content 36 = To-(To-Tn) / Ce.

[0036] The electric kettle 28 is also provided with a gyro sensor 21, which is arranged at the approximate rotation center position of the electric kettle 28, and outputs the rotation angle and rotation direction of the electric kettle 28. The gyro sensor 21 is coupled to the control unit 20, and the temperature set according to the output of the gyro sensor 21 is stored in the temperature setting unit 24. The power supply of the power supply circuit 19 is controlled by the control unit 20 to make the temperature of the contents 36 consistent with the set temperature of the temperature setting unit 24.

[0037] The electric kettle 28 is also provided with a gyro sensor 21, which is arranged at a substantially rotation center position of the electric kettle 28 and outputs the rotation angle and rotation direction of the electric kettle 28. The gyro sensor 21 is coupled to the control unit 20, and the temperature set according to the output of the gyro sensor 21 is stored in the temperature setting unit 24. The control unit 20 controls the power supply of the power supply circuit 19 so that the temperature of the content 36 is consistent with the set temperature of the temperature setting unit 24. A vibration motor 43 is provided inside the electric kettle 28 and coupled to the control unit 20. When the set temperature set by the gyro sensor 21 and stored in the temperature setting unit 24 reaches a specified value, the vibration motor 43 is driven by a signal from the control unit 20, causing the electric kettle 28 to vibrate for notification.

[0038] In a method for estimating the temperature of contents in an electric kettle according to the present invention, the method uses a device comprising: a power supply base 27 having a built-in power supply coil 13; and an electric kettle 28 having a built-in power receiving coil 14, the power receiving coil 14 receiving power from the power supply coil 13 in a contactless manner. The device heats stored contents 36 via a heater 18 provided in the electric kettle 28. The device comprises: a power supply circuit 19 for supplying power to the heater 18; a temperature sensor 22 for detecting the temperature of the heater 18; a control unit 20 coupled to the power supply circuit 19 for controlling energization of the heater 18; a temperature storage unit 25 coupled to the control unit 20 for storing the temperature detected by the temperature sensor 22 via the control unit 20; a temperature estimation coefficient storage unit 29 for storing a preset unique temperature estimation coefficient Ce of the electric kettle 28; and a temperature estimation unit 26 for estimating the temperature of the contents 36 based on data in the temperature storage unit 25 and the temperature estimation coefficient Ce. The method includes: a step of controlling the power supply circuit 19 according to a command from the control unit 20 to apply a pulse voltage to the heater 18, which is repeatedly turned on during a period T11 to T21 and turned off during a period T21 to T31; a step of obtaining the temperature To1 at time T21 and the temperature Tn1 at time T31 by the temperature sensor 22; A step of determining the temperature Te1 actually detected by a temperature sensor different from the temperature sensor 22 of the content 36 at the time T31; a step of calculating the temperature estimation coefficient Ce inherent to the electric kettle 28 by Ce=(To1-Tn1) / (To1-Te1); a step of controlling the power supply circuit 19 according to a command from the control unit 20 to apply a pulse voltage to the heater 18, which is repeatedly turned on during a period T1-T2 and turned off during a period T2-T3; a step of storing the temperature To at time T2 and the temperature Tn at time T3 measured by the temperature sensor 22 in the temperature storage unit 25; and A step of calculating Te=To-(To-Tn) / Ce based on the preset temperature estimation coefficient Ce, To, and Tn to obtain the temperature Te of the content 36 .

[0039] [Example 1] The following is based on Figures 1-6 Example 1 of the present invention will be described.

[0040] exist Figure 1 In the present invention, the method for estimating the temperature of the contents in an electric kettle and the device thereof include a power supply base 27 and an electric kettle 28 placed on the power supply base 27. The power supply coil 13 in the power supply base 27 is magnetically coupled with the power receiving coil 14 in the electric kettle 28, and power is transmitted through electromagnetic induction and the magnetic field resonance of the resonant capacitor.

[0041] The thickness of the power supply seat 27 is as thin as about 10-15mm and the diameter is about 100-200mm. Inside the power supply seat 27, there is a built-in Figure 2 The AC power source 10 shown is connected to an AC adapter 10a, a rectifier circuit 11, an inverter circuit 12 for converting a high-frequency signal, and the power supply coil 13. Alternatively, the AC adapter 10a and the rectifier circuit 11 connected to the AC power source 10 may be provided outside the power supply stand 27.

[0042] The electric kettle 28 contains water or other heated contents 36. The kettle body 37 is airtightly embedded in the outer packaging material 40 at the bottom of the kettle 28 via a gasket 41. The kettle body 37 is constructed of a double wall, consisting of an inner wall 38a and an outer wall 38b, with a vacuum insulation section 39 inside. A lid 42 covers the kettle body 37. A substrate holder 45 is provided between the bottom 44 of the outer packaging material 40 and the bottom of the kettle body 37. A wiring substrate 47 is disposed between the lower side of the substrate holder 45 and a substrate holder cover 46. The power receiving coil 14 is mounted between the lower surface of the substrate holder cover 46 and the bottom 44.

[0043] A vibration motor 43 is installed to the side of the substrate holder 45. A ceramic heater 18, supported by an inner bottom cover 50, is in close contact with the outer surface of the bottom of the electric kettle body 37. A temperature sensor 22 is mounted in close contact with the lower surface of the heater 18. The heater 18 is press-fitted to the bottom of the electric kettle body 37 via a spring plate 48 between the substrate holder 45 and the inner bottom cover 50. The heater 18 is constructed by bending a thin film heater pattern on a thin ceramic plate, with a thin thermistor positioned in the center of the heater pattern.

[0044] On the wiring substrate 47, circuit elements and other circuits are provided. The circuit elements include Figure 2 The microcomputer-based control unit 20 shown in FIG. More specifically, the wiring board 47 includes a resonant capacitor 15 connected to the power receiving coil 14 to transmit power through magnetic field resonance; a rectifier circuit 16 that rectifies the high-frequency power received by the power receiving coil 14; a smoothing capacitor 17; and a power supply circuit 19 including a switching circuit such as a MOS-FET. Furthermore, the following components are connected to the control unit 20: a temperature storage unit 25 that stores the temperature detected by the temperature sensor 22; a temperature estimation unit 26 that estimates the temperature of the contents 36; a non-volatile memory 23 that stores the current set temperature of the electric kettle 28; a gyro sensor 21 located approximately in the center of the wiring board 47 that detects the angular velocity of the electric kettle 28 and sets the temperature of the contents 36; a temperature setting unit 24 that stores the set temperature of the contents 36; and a wireless communication unit 9. Furthermore, the vibration motor 43 is connected to the control unit 20. The temperature estimation coefficient storage unit 29 is connected to the temperature estimation unit 26. The temperature estimation coefficient storage unit 29 stores a temperature estimation coefficient Ce, which is pre-set based on the thermal resistance of the container constituting the electric kettle 28, the material of the container, the heat preservation capacity of the container, the capacity of the container, etc.

[0045] The temperature estimation unit 26 includes: a first subtraction circuit 30 that subtracts Tn (the temperature obtained in step a8 described later) input to the second temperature signal input terminal 34 from To (the temperature obtained in step a5 described later) output from the temperature storage unit 25 and input to the first temperature signal input terminal 33; a division circuit 31 that divides the calculation output To-Tn of the first subtraction circuit 30 by the preset temperature estimation coefficient Ce to obtain (To-Tn) / Ce; and a second subtraction circuit 32 that subtracts the output (To-Tn) / Ce of the division circuit 31 from To output from the temperature storage unit 25 and input to the first temperature signal input terminal 33 to calculate the estimated temperature Te=To-(To-Tn) / Ce of the content 36.

[0046] In addition, Figure 6 In the figure, To and Tn are temperatures detected by repeatedly applying a pulse voltage to the heater 18, which is turned on during T1-T2 and off during T2-T3, in order to obtain the estimated temperature Te of the content 36. To is the temperature obtained by the process a5 described later, and Tn is the temperature obtained by the process a8 described later.

[0047] In such a structure, based on Figure 4 The step of heating the content 36 will be described.

[0048] a1: When the electric kettle 28 is placed at the center of the power supply stand 27, the temperature setting unit 24 initializes the temperature to the set point immediately before the electric kettle 28 was removed from the power supply stand 27, based on the data stored in the non-volatile memory 23 via the control unit 20. For example, the set temperature is initialized to 55°C. At this point, the contents 36 and the heater 18 are considered to be in temperature equilibrium. The temperature of the heater 18 is measured by the temperature sensor 22 and set as the current temperature of the contents 36. For example, the current temperature is assumed to be 50°C.

[0049] a2: At this time, if the set temperature - the current temperature of the contents 36 > a° C. (for example, let a=0.5° C.), the result is “Yes”.

[0050] a3: The control unit 20 closes the power supply circuit 19 and supplies power to the heater 18 to perform heating.

[0051] a4: Wait for t1 seconds (for example, let t1 = 15 seconds).

[0052] a5: The temperature of the heater 18 is detected by the temperature sensor 22 , and this temperature is referred to as To. The temperature is stored in the temperature storage unit 25 via the control unit 20 .

[0053] a6: The power supply circuit 19 is turned off, and heating by the heater 18 is stopped.

[0054] a7: Wait for t2 seconds (for example, let t2 = 5 seconds).

[0055] a8: The temperature of the heater 18 is detected by the temperature sensor 22, and this temperature is referred to as Tn. The temperature is stored in the temperature storage unit 25 via the control unit 20.

[0056] a9: The estimated temperature Te is calculated by the temperature estimation unit 26. Details will be described later.

[0057] a10: The estimated temperature Te is set as the current temperature of the content 36 .

[0058] a11: When the set temperature - the current temperature of the contents 36 > a°C and the result is "yes", the process returns to the initial step a3.

[0059] a12: If the result of "set temperature - current temperature of contents 36 > a°C" in step a11 is "No", wait for t3 seconds (for example, t3 = 40 seconds). This step is to wait for the heater 18 and contents 36 to reach temperature equilibrium.

[0060] a13: The temperature of the heater 18 is detected by the temperature sensor 22, and this temperature is used as the current temperature of the content 36, and the process returns to the above step a2.

[0061] a14: When the set temperature minus the current temperature of the contents 36 > a° C. is “No” in step a2, wait for t4 seconds (for example, t4 = 1 second).

[0062] a15: The temperature of the heater 18 is detected by the temperature sensor 22, and this temperature is used as the current temperature of the content 36, and the process returns to the above step a2.

[0063] based on Figure 5 and Figure 6 , the details of the step a9 in which the temperature estimation unit 26 calculates the estimated temperature Te will be described.

[0064] This process is as follows: without using a direct temperature sensor of the contents 36, the temperature of the contents 36 heated by the electric kettle 28 is estimated using the detection value of the temperature sensor 22 arranged on the bottom outer surface of the electric kettle body 37 and the inherent temperature estimation coefficient Ce of the electric kettle 28.

[0065] For this process, Figure 1When using the electric kettle 28 shown, a temperature estimation coefficient Ce unique to the electric kettle 28 is determined in advance. The heating of the contents 36 by the electric kettle 28 varies depending on factors such as the power supplied to the heater 18, the thermal resistance between the heater 18 and the electric kettle 28, the material of the electric kettle 28, the heat retention capacity of the electric kettle 28, and the capacity of the electric kettle 28. Therefore, the temperature estimation coefficient Ce unique to the electric kettle 28 is determined in advance through the following process.

[0066] exist Figure 6 At T11 , the power supply circuit 19 is closed, and during T11 - T21 (eg, 15 seconds), the heater 18 is energized to heat the heater 18 . The temperature To1 of the heater 18 at this time is detected and stored by the temperature sensor 22 .

[0067] Then, during a period from T21 to T31 (eg, 5 seconds), the heater 18 is de-energized and no heating is performed, and the temperature Tn1 of the heater 18 at this time is detected and stored by the temperature sensor 22 .

[0068] At the same time, the actual temperature of the content 36 at T31 is measured by another temperature sensor (not shown), and the temperature Te1 at that time is stored.

[0069] Based on these values To1 , Tn1 , and Te1 , when developing the electric kettle 28 , a value satisfying the following equation is determined in advance as a temperature estimation coefficient Ce unique to the electric kettle 28 .

[0070] Ce=(To1-Tn1) / (To1-Te1) Incidentally, regarding the temperature estimation coefficient Ce, as a specific example, 0.57 is obtained.

[0071] pass Figure 5 The process is described in detail.

[0072] a91: in Figure 6 At T1, the power supply circuit 19 is closed. The above-mentioned step a3 corresponds to this step.

[0073] a92: The heater 18 heats for a predetermined time (t8 seconds) (T1-T2 time, for example, 15 seconds). The above-mentioned step a4 corresponds to this step.

[0074] a93: The temperature To of the heater 18 at time T2 is detected by the temperature sensor 22, and the temperature To is stored in the temperature storage unit 25 via the control unit 20. The above-mentioned step a5 corresponds to this step.

[0075] a94: At T2, the power supply circuit 19 is turned off to stop heating by the heater 18. The above-mentioned step a6 corresponds to this step.

[0076] a95: No heating is performed for a predetermined time (t9 seconds) (T2-T3 time, for example, 5 seconds). The above-mentioned step a7 corresponds to this step.

[0077] a96: The temperature Tn of the heater 18 at time T3 is detected by the temperature sensor 22, and the temperature Tn is stored in the temperature storage unit 25 via the control unit 20. The above-mentioned step a8 corresponds to this step.

[0078] a97: Based on To and Tn input from the temperature storage unit 25 to the temperature estimation unit 26 and Ce input from the temperature estimation coefficient storage unit 29, the temperature estimation unit 26 calculates the estimated temperature Te. The a9 step corresponds to this step. The calculation performed by the temperature estimation unit 26 for Te is as follows: Figure 3 As shown, the first subtraction circuit 30 subtracts Tn, which is input from the temperature storage unit 25 to the second temperature signal input terminal 34, from To, which is input from the temperature storage unit 25 to the first temperature signal input terminal 33, to obtain (To - Tn). The division circuit 31 divides (To - Tn) obtained by the first subtraction circuit 30 by Ce, which is pre-stored in the temperature estimation coefficient storage unit 29, to obtain (To - Tn) / Ce. The second subtraction circuit 32 subtracts (To - Tn) / Ce obtained by the division circuit 31 from To, which is input to the first temperature signal input terminal 33. As a result, Te is obtained at the output terminal 35 using the following equation.

[0079] Te=To-(To-Tn) / Ce The temperature of the content 36 thus obtained is used as the current temperature for temperature control, is transmitted from the wireless communication unit 9 to the wireless terminal 8 via the control unit 20 , and is displayed on the display unit 7 provided in the wireless terminal 8 .

[0080] When the electric kettle 28 is placed at the center of the power supply stand 27 , the temperature setting unit 24 is initialized to the set temperature immediately before the electric kettle 28 was removed from the power supply stand 27 based on data stored in the nonvolatile memory 23 via the control unit 20 .

[0081] To increase the temperature set in temperature setting unit 24, one places one's hand on electric kettle 28 and rotates it clockwise by a predetermined angle. The gyro sensor 21 then detects the angular velocity of electric kettle 28 and outputs this to control unit 20. Control unit 20 then increases the temperature set in temperature setting unit 24 by, for example, 1°C per 20-degree central angle, and stores the temperature set in temperature setting unit 24 in nonvolatile memory 23.

[0082] The above-described heating process is repeated using the set temperature of the temperature setting unit 24 , so that the temperature of the content 36 rises to the target temperature.

[0083] To lower the temperature set in temperature setting unit 24, one places one's hand on electric kettle 28 and rotates it to the left by a predetermined angle. The gyro sensor 21 then detects the angular velocity of electric kettle 28 and outputs this to control unit 20. Control unit 20 then lowers the temperature set in temperature setting unit 24 by, for example, 1°C for every 20° of central angle, and stores the temperature set in temperature setting unit 24 in nonvolatile memory 23.

[0084] By repeating the heating process using the set temperature of the temperature setting unit 24 , the temperature of the content 36 is lowered to the target temperature.

[0085] exist Figure 1 In the embodiment, a base plate support 45 inside the electric kettle 28 has a built-in vibration motor 43, which can vibrate the electric kettle 28 to inform the user under the conditions shown in Table 1 below.

[0086] [Table 1]

Claims

1. A device for estimating the temperature of contents in an electric kettle, comprising: a power supply base having a built-in power supply coil; and an electric kettle having a built-in power receiving coil, the power receiving coil receiving power from the power supply coil in a contactless manner, wherein the device heats the contents stored in the electric kettle using a heater provided in the electric kettle, characterized in that: have: a power supply circuit that supplies power to the heater; a temperature sensor that detects the temperature of the heater; a control unit coupled to the power supply circuit and configured to control energization of the heater; a temperature storage unit, coupled to the control unit, and configured to store the temperature detected by the temperature sensor via the control unit; a temperature estimation coefficient storage unit storing a preset unique temperature estimation coefficient Ce of the electric kettle; as well as A temperature estimation unit estimates the temperature of the content based on the data in the temperature storage unit and the temperature estimation coefficient Ce.

2. The device for estimating the temperature of contents in an electric kettle according to claim 1, wherein: Regarding the temperature estimation coefficient Ce, when the temperature stored in the temperature storage unit when a pulse voltage is repeatedly applied to the heater during the period T11-T21 and the period T21-T31 while the power supply circuit is controlled according to an instruction from the control unit, the temperature at T21 is To1, the temperature at T31 is Tn1, and the temperature actually detected by a temperature sensor different from the temperature sensor of the contents at T31 is Te1, the temperature estimation coefficient Ce is calculated by the following equation: Ce=(To1-Tn1) / (To1-Te1).

3. The device for estimating the temperature of the contents of an electric kettle according to claim 2, wherein: When the temperature stored in the temperature storage unit is assumed to be the temperature when the power supply circuit is controlled according to the instruction of the control unit and a pulse voltage is applied to the heater that is repeatedly turned on during the period T1-T2 and turned off during the period T2-T3, the temperature at T2 is To and the temperature at T3 is Tn, the estimated temperature Te of the content is calculated by the temperature estimation unit using the following formula: Te=To-(To-Tn) / Ce.

4. The device for estimating the temperature of the contents of an electric kettle according to claim 3, wherein: The temperature estimation unit includes: a first subtraction circuit that subtracts Tn from the output To of the temperature storage unit; a division circuit that divides the calculation output (To-Tn) of the first subtraction circuit by the temperature estimation coefficient Ce to calculate (To-Tn) / Ce; and a second subtraction circuit that subtracts the output (To-Tn) / Ce of the division circuit from the output To of the temperature storage unit to calculate the estimated temperature Te of the contents = To-(To-Tn) / Ce.

5. The device for estimating the temperature of contents in an electric kettle according to claim 1, wherein: The electric kettle is also provided with a gyro sensor, which is arranged at the approximate rotation center position of the electric kettle and outputs the rotation angle and rotation direction of the electric kettle. The gyro sensor is coupled to the control unit, and the temperature set according to the output of the gyro sensor is stored in the temperature setting unit. The power supply of the power supply circuit is controlled by the control unit to make the temperature of the contents consistent with the set temperature of the temperature setting unit.

6. The device for estimating the temperature of contents in an electric kettle according to claim 1, wherein: The electric kettle is also provided with a gyro sensor, which is arranged at the approximate rotation center position of the electric kettle and outputs the rotation angle and rotation direction of the electric kettle. The gyro sensor is coupled to the control unit, and the temperature set according to the output of the gyro sensor is stored in the temperature setting unit. The power supply of the power supply circuit is controlled by the control unit to make the temperature of the contents consistent with the set temperature of the temperature setting unit. A vibration motor is provided inside the electric kettle and coupled to the control unit. When the set temperature based on the gyro sensor reaches a specified value, the vibration motor is driven by a signal from the control unit, causing the electric kettle to vibrate for notification.

7. A method for estimating the temperature of contents in an electric kettle, the method using a device comprising: a power supply stand having a built-in power supply coil; and an electric kettle having a built-in power receiving coil, the power receiving coil receiving power contactlessly from the power supply coil, the device heating the contents stored therein using a heater provided in the electric kettle, the device comprising: a power supply circuit supplying power to the heater; a temperature sensor detecting the temperature of the heater; a control unit coupled to the power supply circuit for controlling energization of the heater; a temperature storage unit coupled to the control unit for storing the temperature detected by the temperature sensor via the control unit; and a temperature estimation coefficient storage unit storing a preset unique temperature estimation coefficient Ce of the electric kettle. and a temperature estimating unit for estimating the temperature of the contents based on the data in the temperature storage unit and the temperature estimation coefficient Ce, the method comprising: a step of controlling the power supply circuit according to a command from the control unit to apply a pulse voltage to the heater that is repeatedly turned on during a period T11 to T21 and turned off during a period T21 to T31; a step of obtaining the temperature To1 at time T21 and the temperature Tn1 at time T31 by the temperature sensor; a step of determining a temperature Te1 actually detected by a temperature sensor different from the temperature sensor of the contents at the time T31; a step of calculating the temperature estimation coefficient Ce inherent to the electric kettle by Ce=(To1-Tn1) / (To1-Te1); a step of controlling the power supply circuit according to a command from the control unit to apply a pulse voltage to the heater that is repeatedly turned on during a period T1-T2 and turned off during a period T2-T3; a step of storing the temperature To at time T2 and the temperature Tn at time T3 measured by the temperature sensor in the temperature storage unit; and A step of calculating Te=To-(To-Tn) / Ce based on the preset temperature estimation coefficient Ce, To, and Tn to obtain the temperature Te of the content.

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