Method and apparatus for estimating content temperature in electric pot

Abstract

To promptly and accurately estimate the heating temperature that varies over time of water or other contents stored in an electric pot without directly measuring the content temperature by using the temperature of a heater.SOLUTION: An apparatus which receives power by a power receiving coil 14 of an electric pot 28 in a non-contact manner from a power supply coil 13 of a power supply base 27, and heats contents 36 by a built-in heater 18, comprises: a power supply circuit 19 which supplies power to the heater 18; a temperature sensor 22 which detects the temperature of the heater 18; a control unit 20 which controls the energization of the heater 18; a temperature storage unit 25 which stores the detection temperature of the temperature sensor 22 via the control unit 20; a temperature estimation coefficient storage unit 29 which stores the preset and specific temperature estimation coefficient Ce of the electric pot 28; and a temperature estimation unit 26 which estimates the temperature of the contents 36 on the basis of the data from the temperature storage unit 25 and the temperature estimation coefficient Ce.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for estimating the temperature of the contents in an electric kettle that accurately estimate the heating temperature of the contents based on a temperature sensor of a heater built in the electric kettle.

Background Art

[0002] Conventionally, an electric kettle as shown in FIG. 7 has been known (Patent Document 1). In FIG. 7, an annular heater 52 is provided as a heating means at the outer bottom of a container 51, and a temperature-sensitive element (thermistor) 53 is attached to the center thereof so as to be in pressure contact with the container 51. The temperature of the water in the container 51 is indirectly detected by a temperature detection means 54 including the temperature-sensitive element 53 as a part. When power is supplied to the heater 52 to start heating, a temperature gradient detection means 55 detects a temperature gradient from the output of the temperature detection means 54 and stores the value in a first storage means 56 under predetermined conditions.

[0003] Then, a gradient comparison means 57 compares the value stored in the first storage means 56 with the output of the temperature gradient detection means 55 and outputs when it becomes equal to or less than a predetermined ratio. On the other hand, a temperature comparison means 58 compares the output of the temperature detection means 54 with a value stored in a non-volatile second storage means 59 and outputs when the output of the temperature detection means 54 becomes equal to or greater than the stored value. And a boiling detection means 60 detects boiling when one of the output of the gradient comparison means 57 and the output of the temperature comparison means 58 is obtained, stops the power supply to the heater 52, and stores the output of the temperature detection means 54 at this time in the second storage means 59. It is described as follows.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The invention described in Patent Document 1 aims to provide an electric kettle that detects boiling. An annular heater 52 is provided as a heating means at the outer bottom of a container 51, and a temperature-sensitive element (thermistor) 53 is attached to the central portion thereof so as to be in pressure contact with the container 51. Therefore, the detected temperature is the outer bottom of the container 51. Accordingly, since the actual temperature characteristics of the water in the container 51 vary depending on the thermal resistance of the container, the material of the container, the heat retention ability of the container, the capacity of the container, etc., the actual temperature of the water had to be detected indirectly by the temperature detection means 54. Further, when power is supplied to the heater 52 to start heating, since the temperature gradient detection means 55 detects the temperature gradient from the output of the temperature detection means 54, the actual temperature of the water takes time and rapid temperature detection could not be achieved.

[0006] An object of the present invention is to provide a method and an apparatus for estimating the temperature of contents in an electric kettle that enables rapid and accurate estimation of the constantly changing temperature of water or other contents during heating.

Means for Solving the Problems

[0007] The apparatus for estimating the temperature of contents in an electric kettle according to the present invention is comprising a power supply stand 27 incorporating a power supply coil 13 and an electric kettle 28 incorporating a power receiving coil 14 that receives power wirelessly from the power supply coil 13, in an apparatus for heating contents 36 accommodated by a heater 18 provided in the electric kettle 28, 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 that controls the energization of the heater 18, a temperature storage unit 25 coupled to the control unit 20 that stores the detected temperature of the temperature sensor 22 via the control unit 20, A temperature estimation coefficient storage unit 29 that stores a preset specific temperature estimation coefficient Ce of the electric kettle 28; A temperature estimation unit 26 that estimates the temperature of the content 36 based on the data of the temperature storage unit 25 and the temperature estimation coefficient Ce; It is characterized by comprising the above.

[0008] The temperature estimation coefficient Ce is the temperature stored in the temperature storage unit 25 when a pulse voltage that is turned on between T11 - T21 and turned off between T21 - T31 is applied to the heater 18 by controlling the power supply circuit 19 according to a command from the control unit 20. When the temperature at T21 is To1, the temperature at T31 is Tn1, and the temperature actually measured 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. Ce = (To1 - Tn1) / (To1 - Te1)

[0009] The estimated temperature Te of the content 36 is The temperature stored in the temperature storage unit 25 when a pulse voltage that is turned on between T1 - T2 and turned off between T2 - T3 is applied to the heater 18 by controlling the power supply circuit 19 according to a command from the control unit 20. When the temperature at T2 is To and the temperature at T3 is Tn, the estimated temperature Te of the content 36 is obtained by calculating the following formula in the temperature estimation unit 26. Te = To - (To - Tn) / Ce

[0010] 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 = To - (To - Tn) / Ce of the content 36.

[0011] A gyro sensor 21 is further provided at a substantially rotation center position of the electric kettle 28, which outputs the rotation angle and rotation direction of the electric kettle 28. The gyro sensor 21 is coupled to the control unit 20. The temperature set by 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 to make the temperature of the content 36 coincide with the set temperature of the temperature setting unit 24.

[0012] A gyro sensor 21 is further provided at a substantially rotation center position of the electric kettle 28, which outputs the rotation angle and rotation direction of the electric kettle 28. The gyro sensor 21 is coupled to the control unit 20. The temperature set by 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 to make the temperature of the content 36 coincide with the set temperature of the temperature setting unit 24. A vibration motor 43 is provided inside the electric kettle 28. The vibration motor 43 is 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 predetermined value, the control unit 20 drives the vibration motor 43 with a signal to vibrate the electric kettle 28 for notification.

[0013] The method for estimating the temperature of the content in the electric kettle according to the present invention is A device includes a power supply stand 27 incorporating a power supply coil 13, and an electric kettle 28 incorporating a power receiving coil 14 for non-contact power reception from the power supply coil 13, and heats the contents 36 contained by 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 detected temperature of the temperature sensor 22 via the control unit 20, a temperature estimation coefficient storage unit 29 for storing a preset specific 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 the data of the temperature storage unit 25 and the temperature estimation coefficient Ce. Controlling the power supply circuit 19 according to a command of the control unit 20 to apply a pulsed voltage to the heater 18, which is turned on between T11 and T21 and turned off between T21 and T31, repeatedly. Obtaining the temperature To1 at T21 and the temperature Tn1 at T31 by the temperature sensor 22. Obtaining the actually measured temperature Te1 at T31 of the contents 36 by a temperature sensor different from the temperature sensor 22. Obtaining the specific temperature estimation coefficient Ce of the electric kettle 28 by Ce = (To1 - Tn1) / (To1 - Te1). Controlling the power supply circuit 19 according to a command of the control unit 20 to apply a pulsed voltage to the heater 18, which is turned on between T1 and T2 and turned off between T2 and T3, repeatedly. Storing the temperature To at T2 and the temperature Tn at T3 measured by the temperature sensor 22 in the temperature storage unit 25. Obtaining the temperature Te of the contents 36 by calculation of Te = To - (To - Tn) / Ce based on the preset temperature estimation coefficient Ce, the To, and the Tn. It is characterized by comprising the above steps.

Advantages of the Invention

[0014] According to the invention described in claim 1, A device comprising a power supply stand with a built-in power supply coil and an electric kettle with a built-in power receiving coil for non-contact power reception from the power supply coil, and heating the contents contained by a heater provided in the electric kettle. A power supply circuit for supplying power to the heater; A temperature sensor for 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 detected temperature of the temperature sensor via the control unit; A temperature estimation coefficient storage unit for storing a unique temperature estimation coefficient Ce set in advance for the electric kettle; A temperature estimation unit for estimating the temperature of the contents based on the data of the temperature storage unit and the temperature estimation coefficient Ce Since it is provided, without using a temperature sensor that directly measures the temperature of the contents, by setting and registering in advance the unique temperature estimation coefficient Ce of the electric kettle, the temperature of the contents can be accurately and quickly estimated from the measured value of the temperature sensor that measures the temperature of the heater.

[0015] According to the invention described in claim 2, The temperature estimation coefficient Ce is the temperature stored in the temperature storage unit when a pulse voltage that turns on between T11 - T21 and turns off between T21 - T31 is applied to the heater by controlling the power supply circuit according to a command from the control unit. When the temperature at T21 is To1, the temperature at T31 is Tn1, and the temperature actually measured by a temperature sensor different from the temperature sensor of the contents at T31 is Te1, the temperature estimation coefficient Ce is Ce = (To1 - Tn1) / (To1 - Te1) Since it is calculated and obtained in this way, the unique temperature estimation coefficient Ce of the electric kettle can be easily obtained.

[0016] According to the invention described in claim 3, The temperature stored in the temperature storage unit when a pulse voltage that turns on between T1 - T2 and turns off between T2 - T3 is applied to the heater by controlling the power supply circuit according to the command of the control unit. When 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 Te = To - (To - Tn) / Ce can be easily and accurately obtained by calculation.

[0017] According to the invention described in 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 this first subtraction circuit by the temperature estimation coefficient Ce to obtain (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 content. Therefore, the temperature estimation unit can be composed of simple subtraction circuits and division circuits.

[0018] According to the invention described in claim 5, Furthermore, a gyro sensor is provided at a substantially rotation center position of the electric kettle, which outputs the rotation angle and rotation direction of the electric kettle. This gyro sensor is coupled to the control unit, the temperature set by the output of the gyro sensor is stored in the temperature setting unit, and the control unit controls the power supply of the power supply circuit so that the temperature of the content matches the set temperature of the temperature setting unit. Therefore, the set temperature can be set by the rotation angle and rotation direction of the electric kettle.

[0019] According to the invention described in claim 6, Further provided is a gyro sensor which is provided at a substantially 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 a temperature setting unit. The control unit controls the power supply of the power supply circuit so that the temperature of the content matches the set temperature of the temperature setting unit. A vibration motor is provided inside the electric kettle, and the vibration motor is coupled to the control unit. When the set temperature by the gyro sensor reaches a predetermined value, the control unit drives the vibration motor by a signal to vibrate the electric kettle for notification. Therefore, the set temperature can be sensed by touch.

[0020] According to the invention described in claim 7, A device comprising a power supply base incorporating a power supply coil and an electric kettle incorporating a power receiving coil for non-contact power reception from the power supply coil, the device heating the content accommodated by a heater provided in the electric kettle, the device comprising a power supply circuit for supplying power to the heater, a temperature sensor for detecting the temperature of the heater, a control unit coupled to the power supply circuit for controlling the energization of the heater, a temperature storage unit coupled to the control unit for storing the detected temperature of the temperature sensor via the control unit, a temperature estimation coefficient storage unit for storing a specific temperature estimation coefficient Ce set in advance for the electric kettle, and a temperature estimation unit for estimating the temperature of the content based on the data of the temperature storage unit and the temperature estimation coefficient Ce. A step of controlling the power supply circuit according to a command of the control unit to apply a pulse voltage to the heater, which is turned on between T11 and T21 and turned off between T21 and T31 in a repeating manner. A step of obtaining, by the temperature sensor, the temperature To1 at T21 and the temperature Tn1 at T31. A step of obtaining the actually measured temperature Te1 at T31 by a temperature sensor different from the temperature sensor of the content at T31. A step of obtaining the specific temperature estimation coefficient Ce of the electric kettle by Ce = (To1 - Tn1) / (To1 - Te1). A step of controlling the power supply circuit according to a command of the control unit to apply a pulse voltage to the heater, which is turned on between T1 and T2 and turned off between T2 and T3; A step of storing, in the temperature storage unit, the temperature To at T2 and the temperature Tn at T3 measured by the temperature sensor; A step of obtaining the temperature Te of the content based on the preset temperature estimation coefficient Ce, To, and Tn by calculating Te = To - (To - Tn) / Ce; Since it consists of the above, the temperature of the content can be estimated according to the unique characteristics of the electric kettle.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0022] An apparatus for estimating the temperature of the content in an electric kettle according to the present invention is A device comprising a power supply base 27 incorporating a power supply coil 13 and an electric kettle 28 incorporating a power receiving coil 14 for non-contact power reception from the power supply coil 13, and heating the contents 36 contained in the electric kettle 28 with a heater 18 provided in the electric kettle 28. 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 detected temperature of the temperature sensor 22 via the control unit 20; A temperature estimation coefficient storage unit 29 for storing a specific temperature estimation coefficient Ce preset for the electric kettle 28; A temperature estimation unit 26 for estimating the temperature of the contents 36 based on the data of the temperature storage unit 25 and the temperature estimation coefficient Ce It consists of.

[0023] The temperature estimation coefficient Ce is the temperature stored in the temperature storage unit 25 when a pulse voltage that turns on between T11 - T21 and turns off between T21 - T31 is applied to the heater 18 by controlling the power supply circuit 19 according to a command from the control unit 20. Let the temperature at T21 be To1, the temperature at T31 be Tn1, and the temperature actually measured by a temperature sensor different from the temperature sensor 22 of the contents 36 at T31 be Te1. Then, the temperature estimation coefficient Ce is obtained by calculating the following formula. Ce = (To1 - Tn1) / (To1 - Te1)

[0024] When a pulse voltage that turns on between T1 - T2 and turns off between T2 - T3 is applied to the heater 18 by controlling the power supply circuit 19 according to a command from the control unit 20, and the temperature stored in the temperature storage unit 25 at this time is considered, with the temperature at T2 being To and the temperature at T3 being Tn, the estimated temperature Te of the contents 36 is obtained by the temperature estimation unit 26 calculating the following formula. Te = To - (To - Tn) / Ce

[0025] 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 = To - (To - Tn) / Ce of the content 36.

[0026] The electric kettle 28 further includes a gyro sensor 21 provided at a substantially rotation center position of the electric kettle 28, which outputs the rotation angle and rotation direction of the electric kettle 28. The gyro sensor 21 is coupled to the control unit 20, the temperature set by the output of the gyro sensor 21 is stored in the temperature setting unit 24, and the control unit 20 controls the power supply of the power supply circuit 19 to make the temperature of the content 36 coincide with the set temperature of the temperature setting unit 24.

[0027] The electric kettle 28 further includes a gyro sensor 21 provided at a substantially rotation center position of the electric kettle 28, which outputs the rotation angle and rotation direction of the electric kettle 28. The gyro sensor 21 is coupled to the control unit 20, the temperature set by the output of the gyro sensor 21 is stored in the temperature setting unit 24, and the control unit 20 controls the power supply of the power supply circuit 19 to make the temperature of the content 36 coincide with the set temperature of the temperature setting unit 24. A vibration motor 43 is provided inside the electric kettle 28, the vibration motor 43 is coupled to the control unit 20, and when the set temperature set by the gyro sensor 21 and stored in the temperature setting unit 24 reaches a predetermined value, the control unit 20 drives the vibration motor 43 with a signal to vibrate the electric kettle 28 for notification.

[0028] A device comprising a power supply base 27 incorporating a power supply coil 13 and an electric kettle 28 incorporating a power receiving coil 14 for non-contact power reception from the power supply coil 13, and heating the contents 36 contained by a heater 18 provided in the electric kettle 28, the device comprising 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 detected temperature of the temperature sensor 22 via the control unit 20, a temperature estimation coefficient storage unit 29 for storing a unique temperature estimation coefficient Ce preset for the electric kettle 28, and a temperature estimation unit 26 for estimating the temperature of the contents 36 based on the data of the temperature storage unit 25 and the temperature estimation coefficient Ce is used, Controlling the power supply circuit 19 according to a command of the control unit 20 to apply a pulsed voltage to the heater 18 that is on between T11 - T21 and off between T21 - T31 in repetition; Obtaining the temperature To1 at T21 and the temperature Tn1 at T31 by the temperature sensor 22; Obtaining the temperature Te1 actually measured by a temperature sensor different from the temperature sensor 22 of the contents 36 at T31; Obtaining the unique temperature estimation coefficient Ce of the electric kettle 28 by Ce = (To1 - Tn1) / (To1 - Te1); Controlling the power supply circuit 19 according to a command of the control unit 20 to apply a pulsed voltage to the heater 18 that is on between T1 - T2 and off between T2 - T3 in repetition; Storing the temperature To at T2 and the temperature Tn at T3 measured by the temperature sensor 22 in the temperature storage unit 25; Obtaining the temperature Te of the contents 36 by calculation of Te = To - (To - Tn) / Ce based on the preset temperature estimation coefficient Ce, the To, and the Tn; It consists of.

Example

[0029] Hereinafter, Example 1 of the present invention will be described with reference to FIGS. 1 to 6. In FIG. 1, the method and apparatus for estimating the temperature of the contents in the electric kettle according to the present invention comprise a power supply stand 27 and an electric kettle 28 placed on the power supply stand 27. The power supply coil 13 in the power supply stand 27 and the power receiving coil 14 in the electric kettle 28 are magnetically coupled, and electric power is transmitted by electromagnetic induction and the magnetic field resonance action of a resonance capacitor. The power supply stand 27 is as thin as about 10 to 15 mm in thickness and about 100 to 200 mm in diameter. Inside the power supply stand 27, an AC adapter 10a connected to an AC power supply 10 as shown in FIG. 2, a rectifier circuit 11, an inverter circuit 12 for converting to a high-frequency signal, and the power supply coil 13 are incorporated. Note that the AC adapter 10a connected to the AC power supply 10 and the rectifier circuit 11 may be provided outside the power supply stand 27. The electric kettle 28 contains water or other contents 36 to be heated inside. The electric kettle 28 has an electric kettle body 37 airtightly fitted into a lower exterior member 40 with a packing 41 interposed therebetween. The electric kettle body 37 is composed of a double wall of an inner wall portion 38a and an outer wall portion 38b, and the inside is a vacuum insulation portion 39. A lid 42 is placed on the electric kettle body 37. A substrate holder 45 is provided between the bottom 44 of the exterior member 40 and the bottom of the electric kettle body 37. A wiring board 47 is arranged between the substrate holder 45 and a substrate holder cover 46 on the lower side thereof, and the power receiving coil 14 is attached between the lower surface of the substrate holder cover 46 and the bottom 44.

[0030] A vibration motor 43 is provided on the side of the substrate holder 45. A heater 18 such as ceramic 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 closely attached to the lower surface of the heater 18. The heater 18 is pressed against the bottom of the electric kettle body 37 by a spring plate 48 between the substrate holder 45 and the inner bottom cover 50. The heater 18 is formed by a heater pattern meandering on a thin ceramic plate, and a thin thermistor is provided at the center of the heater pattern. The wiring board 47 is provided with a circuit element including a control unit 20 by a microcomputer as shown in FIG. 2 and other circuits. More specifically, the wiring board 47 includes a resonance capacitor 15 through which power is conducted by the magnetic resonance action connected to the power receiving coil 14, 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 composed of a switch circuit such as a MOS-FET. Further, the control unit 20 is connected to 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 content 36, a non-volatile memory 23 that stores the current set temperature of the electric kettle 28, a gyro sensor 21 that detects the angular velocity of the electric kettle 28 provided substantially at the center of the wiring board 47 and sets the temperature of the content 36, a temperature setting unit 24 that stores the set temperature of the content 36, and a wireless communication unit 9. Furthermore, the vibration motor 43 is connected. The temperature estimation unit 26 is connected to a temperature estimation coefficient storage unit 29 that stores a temperature estimation coefficient Ce preset based on the thermal resistance of the container constituting the electric kettle 28, the material of the container, the heat retention ability of the container, the capacity of the container, and the like.

[0031] The temperature estimation unit 26 includes a first subtraction circuit 30 that subtracts Tn (the temperature obtained in step a8 described later) input to a 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 a first temperature signal input terminal 33, a division circuit 31 that divides the arithmetic 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. In FIG. 6, To and Tn are temperatures detected by applying a pulse voltage that is turned on between T1 and T2 and turned off between T2 and T3 to the heater 18 in order to obtain the estimated temperature Te of the content 36. To is the temperature obtained in step a5 described later, and Tn is the temperature obtained in step a8 described later.

[0032] In such a configuration, the heating process of the content 36 will be described based on FIG. 4. a1: When the electric kettle 28 is placed at the center position of the power supply base 27, the temperature setting unit 24 is initialized to the set temperature immediately before the electric kettle 28 is removed from the power supply base 27 according to the data stored in the non-volatile memory 23 via the control unit 20. For example, assume that the set temperature is initialized to 55°C. At this time, the content 36 and the heater 18 are considered to be in a temperature equilibrium state. The temperature of the heater 18 is measured by the temperature sensor 22, and this temperature is taken as the current temperature of the content 36. For example, assume that the current temperature is 50°C. a2: At this time, set temperature - current temperature of the content 36 > a°C (for example, a = 0.5°C) becomes YES. a3: The control unit 20 closes the power supply circuit 19 to supply power to the heater 18 for heating. a4: Wait for t1 seconds (for example, t1 = 15 seconds). a5: The temperature of the heater 18 is detected by the temperature sensor 22, and this temperature is denoted as To and stored in the temperature storage unit 25 via the control unit 20. a6: Open the power supply circuit 19 to stop heating by the heater 18.

[0033] a7: Wait for t2 seconds (for example, t2 = 5 seconds). a8: The temperature of the heater 18 is detected by the temperature sensor 22, and this temperature is denoted as Tn and stored in the temperature storage unit 25 via the control unit 20. a9: The estimated temperature Te is calculated by the temperature estimation unit 26. Details will be described later. a10: The estimated temperature Te is taken as the current temperature of the content 36. a11: When set temperature - current temperature of the content 36 > a°C becomes YES, return to the initial a3 step. a12: When set temperature - current temperature of the content 36 > a°C becomes NO in the a11 step, wait for t3 seconds (for example, t3 = 40 seconds). This step is to wait for the heater 18 and the content 36 to reach a temperature equilibrium state. a13: Detect the temperature of the heater 18 with the temperature sensor 22, use this temperature as the current temperature of the content 36, and return to the step a2. a14: In the step a2, when the set temperature - the current temperature of the content 36 > a °C is NO, wait for t4 seconds (for example, assume t4 = 1 second). a15: Detect the temperature of the heater 18 with the temperature sensor 22, use this temperature as the current temperature of the content 36, and return to the step a2.

[0034] The details of the step of calculating the estimated temperature Te by the temperature estimation unit 26 in a9 will be described based on FIGS. 5 and 6. This step is a step of estimating the temperature of the content 36 heated by the electric kettle 28 without using a direct temperature sensor for the content 36, using the detected value of the temperature sensor 22 provided on the outer bottom surface of the electric kettle body 37 and the specific temperature estimation coefficient Ce of the electric kettle 28. For this step, at the time of developing the electric kettle 28 shown in FIG. 1, the specific temperature estimation coefficient Ce of this electric kettle 28 is obtained in advance. The heating of the content 36 by the electric kettle 28 depends on 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 ability of the electric kettle 28, the capacity of the electric kettle 28, etc. The correlation between the heating of the heater 18 and the temperature of the content 36 is different. Therefore, the specific temperature estimation coefficient Ce of the electric kettle 28 is set in advance in the following step. In FIG. 6, close the power supply circuit 19 at T11 and energize and heat the heater 18 for T11 - T21 (for example, 15 seconds). Detect and store the temperature To1 of the heater 18 at this time with the temperature sensor 22. Next, for T21 - T31 (for example, 5 seconds), stop the power supply to the heater 18 to make it non - heating, and detect and store the temperature Tn1 of the heater 18 at this time with the temperature sensor 22. At the same time, measure the actual temperature of the content 36 at T31 with another temperature sensor (not shown), and store the temperature Te1 at this time. Based on these values To1, Tn1, Te1, When developing the electric kettle 28, a value that satisfies the following formula is obtained in advance as the specific temperature estimation coefficient Ce of the electric kettle 28. Ce = (To1 - Tn1) / (To1 - Te1) Incidentally, as a specific example, the temperature estimation coefficient Ce was obtained as 0.57.

[0035] The process will be described in detail with reference to FIG. 5. a91: Close the power supply circuit 19 at time T1 in FIG. 6. The step a3 corresponds to this step. a92: Heat the heater 18 for a predetermined time (t8 seconds, the time between T1 and T2, for example, 15 seconds). The step a4 corresponds to this step. a93: Detect the temperature To of the heater 18 at time T2 with the temperature sensor 22, and store this To in the temperature storage unit 25 via the control unit 20. The step a5 corresponds to this step. a94: Open the power supply circuit 19 at time T2 to stop heating by the heater 18. The step a6 corresponds to this step. a95: Perform non-heating for a predetermined time (t9 seconds, the time between T2 and T3, for example, 5 seconds). The step a7 corresponds to this step. a96: Detect the temperature Tn of the heater 18 at time T3 with the temperature sensor 22, and store this Tn in the temperature storage unit 25 via the control unit 20. The step a8 corresponds to this step. The temperature estimation unit 26 calculates the estimated temperature Te based on To and Tn input from the temperature memory unit 25 and Ce input from the temperature estimation coefficient memory unit 29. The step a9 corresponds to this step. As shown in FIG. 3, the calculation of Te by the temperature estimation unit 26 is as follows: From To input from the temperature memory unit 25 to the first temperature signal input terminal 33, Tn input from the temperature memory unit 25 to the second temperature signal input terminal 34 is subtracted by the first subtraction circuit 30 to obtain (To - Tn). In the division circuit 31, (To - Tn) obtained by the first subtraction circuit 30 is divided by Ce pre-stored in the temperature estimation coefficient memory unit 29 to obtain (To - Tn) / Ce. In the second subtraction circuit 32, (To - Tn) / Ce obtained by the division circuit 31 is subtracted from To input to the first temperature signal input terminal 33. As a result, Te is obtained at the output terminal 35 by the following equation. Te = To - (To - Tn) / Ce The temperature of the content 36 obtained in this way is used as the current temperature for temperature control, and 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.

[0036] When the electric kettle 28 is placed on the center position of the power supply base 27, the temperature setting unit 24 is initialized to the immediately previous set temperature when the electric kettle 28 is removed from the power supply base 27 according to the data stored in the non-volatile memory 23 via the control unit 20. When trying to increase the set temperature of the temperature setting unit 24, touch the electric kettle 28 and rotate it in the right direction by a predetermined angle. Then, the gyro sensor 21 detects the angular velocity of the electric kettle 28 and outputs it to the control unit 20. The control unit 20, for example, increases the set temperature of the temperature setting unit 24 by 1 °C for every 20 degrees of the central angle, and stores the set temperature of the temperature setting unit 24 in the non-volatile memory 23. By repeating the heating step using the set temperature of the temperature setting unit 24, the temperature of the content 36 rises to the target temperature. When attempting to lower the set temperature of the temperature setting unit 24, place a hand on the electric kettle 28 and rotate it leftward by a predetermined angle. Then, the gyro sensor 21 detects the angular velocity of the electric kettle 28 and outputs it to the control unit 20. The control unit 20, for example, lowers the set temperature of the temperature setting unit 24 by 1 °C for every 20 degrees of the central angle, and stores the set temperature of the temperature setting unit 24 in the non-volatile memory 23. By repeating the heating process using the set temperature of this temperature setting unit 24, the temperature of the contents 36 drops to the target temperature.

[0037] In FIG. 1, a vibration motor 43 is built into the substrate holder 45 inside the electric kettle 28, and the electric kettle 28 can be vibrated to notify the user in the cases shown in Table 1 below.

Table 1

Explanation of Signs

[0038] 7... display unit, 8... wireless terminal, 9... wireless communication unit, 10... AC power supply, 11... rectifier circuit, 12... inverter circuit, 13... power feeding coil, 14... power receiving coil, 15... resonance 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 memory unit, 26... temperature estimation unit, 27... power feeding station, 28... electric kettle, 29... temperature estimation coefficient memory 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... content, 37... electric kettle body, 38a... inner wall portion, 38b... outer wall portion, 39... vacuum heat insulation portion, 40... exterior material, 41... packing, 42... lid, 43... vibration motor, 44... bottom, 45... substrate holder, 46... substrate holder cover, 47... wiring board, 48... spring plate, 49... mica plate, 50... inner bottom cover, 51... container, 52... heater, 53... temperature sensing element, 54... temperature detection means, 55... temperature gradient detection means, 56... first storage means, 57... gradient comparison means, 58... temperature comparison means, 59... second storage means, 60... boiling detection means.

Claims

1. An apparatus for heating contents contained in an electric kettle by a heater provided in the 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 for wireless power reception from the power supply coil, a power supply circuit for supplying power to the heater, a temperature sensor for 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 detected temperature of the temperature sensor via the control unit, a temperature estimation coefficient storage unit for storing a unique temperature estimation coefficient Ce preset for the electric kettle, and a temperature estimation unit for estimating the temperature of the contents based on the data of the temperature storage unit and the temperature estimation coefficient Ce. An apparatus for estimating the temperature of contents in an electric kettle, characterized by comprising the above components.

2. The temperature estimation coefficient Ce is the temperature stored in the temperature storage unit when a pulse voltage that turns on between T11 - T21 and turns off between T21 - T31 is applied to the heater by controlling the power supply circuit according to a command of the control unit. When the temperature at T21 is To1, the temperature at T31 is Tn1, and the temperature actually measured by a temperature sensor different from the temperature sensor of the contents at T31 is Te1, the temperature estimation coefficient Ce is obtained by calculating the following formula. The apparatus for estimating the temperature of contents in an electric kettle according to Claim 1, characterized by this. Ce = (To1 - Tn1) / (To1 - Te1)

3. The temperature stored in the temperature storage unit when a pulse voltage that turns on between T1 - T2 and turns off between T2 - T3 is applied to the heater by controlling the power supply circuit according to a command of the control unit. When the temperature at T2 is To and the temperature at T3 is Tn, the estimated temperature Te of the contents is obtained by calculating the following formula in the temperature estimation unit. The apparatus for estimating the temperature of contents in an electric kettle according to Claim 2, characterized by this. Te = To - (To - Tn) / Ce

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 arithmetic output (To - Tn) of the first subtraction circuit by the temperature estimation coefficient Ce to obtain (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 content. The apparatus for estimating the temperature of the content in the electric kettle according to claim 3 is characterized by comprising the above.

5. The electric kettle further includes a gyro sensor provided at a substantially rotation center position of the electric kettle, which outputs a rotation angle and a rotation direction of the electric kettle. The gyro sensor is coupled to the control unit, the temperature set by the output of the gyro sensor is stored in the temperature setting unit, and the control unit controls the power supply of the power supply circuit so that the temperature of the content coincides with the set temperature of the temperature setting unit. The apparatus for estimating the temperature of the content in the electric kettle according to claim 1 is characterized by the above.

6. The electric kettle further includes a gyro sensor provided at a substantially rotation center position of the electric kettle, which outputs a rotation angle and a rotation direction of the electric kettle. The gyro sensor is coupled to the control unit, the temperature set by the output of the gyro sensor is stored in the temperature setting unit, and the control unit controls the power supply of the power supply circuit so that the temperature of the content coincides with the set temperature of the temperature setting unit. A vibration motor is provided inside the electric kettle, the vibration motor is coupled to the control unit, and when the set temperature by the gyro sensor reaches a predetermined value, the control unit drives the vibration motor with a signal to vibrate the electric kettle for notification. The apparatus for estimating the temperature of the content in the electric kettle according to claim 1 is characterized by the above.

7. The present invention relates to an apparatus for heating contents stored in an electric kettle, the apparatus comprising: a power supply stand having a built-in power supply coil; and an electric kettle having a built-in power receiving coil that receives power from the power supply coil in a non-contact manner, the apparatus comprising: a power supply circuit that supplies power to the heater; a temperature sensor that detects the temperature of the heater; a control unit that is connected to the power supply circuit and controls the supply of power to the heater; a temperature memory unit that is connected to the control unit and stores the temperature detected by the temperature sensor via the control unit; a temperature estimation coefficient memory unit that stores a preset unique 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 memory unit and the temperature estimation coefficient Ce, a step of controlling the power supply circuit according to a command from the control unit to apply a pulse voltage to the heater, the pulse voltage being turned on between T11 and T21 and turned off between T21 and T31; determining a temperature To1 at time T21 and a temperature Tn1 at time T31 by the temperature sensor; A step of determining a temperature Te1 of the content at time T31 measured by a temperature sensor different from the temperature sensor; A step of calculating the temperature estimation coefficient Ce specific to the electric pot 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, the pulse voltage being turned on during T1-T2 and turned off during T2-T3; storing the temperature To at time T2 and the temperature Tn at time T3 measured by the temperature sensor in the temperature storage unit; A step of calculating a temperature Te of the contents based on the preset temperature estimation coefficient Ce, the To and the Tn by a calculation of Te=To-(To-Tn) / Ce; A method for estimating the temperature of contents in an electric kettle comprising the steps of:

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