JPH05190264A - Cordless equipment - Google Patents

Abstract

PURPOSE:To provide a cooking device actuated cordlessly. CONSTITUTION:A device comprises a magnetism generating part 7 and a load part 8 which can be mounted onto the magnetism generating part 7. The magnetism generating part 7 has a top plate 9, primary coil 10 provided below the top plate 9 and an inverter 13. The load part 8 has a metal-made heat generating part 16 induction heated by receiving a magnetic field of the primary coil 10 in a condition mounted onto the magnetism generating part 7, secondary coil 17 provided downward of the heat generating part 16 and a load circuit 18 with power supplied from the secondary coil 17. In a cordless equipment, a diameter of the secondary coil 17 is about half the sum of external and internal diameters of the primary coil 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device used cordlessly in ordinary households.

[0002]

2. Description of the Related Art Conventionally, a heating device such as a jar pot has been operated by a commercial power source by inserting a power cord into an outlet provided on a wall of a house or the like.

FIG. 4 shows a jar pot in such a conventional technique. Reference numeral 1 is a power cord for drawing in a commercial power source of AC100V. Reference numeral 2 is a tank for storing water, 3 is a heater, and 4 is a thermistor for detecting the water temperature. Further, 5 is the heater 3 based on the temperature information detected by the thermistor 4.
Is a control circuit for controlling. A power supply circuit 6 supplies power to the control circuit 5.

At the time of use, the user connects the power cord 1 to an outlet provided on a wall or the like. When the temperature of the water in the tank 2 is low, the resistance value of the thermistor 4 is large, and the control circuit 5 supplies power to the heater 3 to heat the water in the tank 2. When the water temperature in the tank 2 rises, the resistance value of the thermistor 4 decreases, and the control circuit 5 acts so as to cut off the current of the heater 3. In this way, the water temperature in the tank 2 is controlled, and boiling water is performed. The control circuit 5 is generally composed of a microcomputer or the like, and supplies a low voltage required for the control circuit 5 from a power supply circuit 6 using a transformer.

[0005]

The jar pot having the above-mentioned conventional structure has a power cord 1 for supplying electric power to an appliance.
The power cord 1 must be connected to the outlet when using. For this reason, it is troublesome to handle, and it is troublesome to dispose of the power cord 1 even when it is put on after use, and the power cord 1 is also designed.
Is a bottleneck. Further, in various cooking utensils such as a jar pot, since a heater is built in each heating device, there is also a problem that the weight becomes large.

The present invention is intended to solve such a problem, and an object thereof is to provide a device that operates cordlessly.

[0007]

In order to achieve the above object, the present invention comprises a magnetism generating part and a load part mountable on the magnetism generating part, wherein the magnetism generating part comprises a top plate, A metal coil that has a primary coil provided under the top plate and an inverter, and is subjected to induction heating by receiving the magnetic field of the primary coil in a state where the load section is placed on the magnetic field generating section. A heat generating part, a secondary coil provided below the heat generating part, and a load circuit supplied with electric power from the secondary coil, and the diameter of the secondary coil is the outer diameter and the inner diameter of the primary coil. It is a cordless device that is about half the sum.

[0008]

The cordless device of the present invention having the above structure
When the load section is set on the magnetic field generating section, the inverter provided in the magnetic field generating section operates to supply a high frequency current to the primary coil, and the load section is induction-heated. At the same time, a voltage is also generated in the secondary coil that is magnetically coupled to the primary coil, and this voltage is supplied to the load circuit and the temperature detection circuit / transmission circuit operates, acting as a device that is easy to use. is there.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a cordless device having a water heating function in one embodiment of the present invention. Reference numeral 7 denotes a magnetism generating portion that heats the load portion 8, reference numeral 8 denotes a load portion that can be placed on the magnetism generating portion 7, and shows a jar pot of this embodiment.

The magnetic field generator 7 includes the following parts. Reference numeral 9 is a ceramic top plate on which the load portion 8 and the like are mounted. Reference numeral 10 denotes a disk-shaped primary coil provided below the top plate 9 and generates a high-frequency magnetic field. Reference numeral 11 denotes a pot detecting means for detecting whether or not a pot is placed on the top plate 9 from the relationship between the voltage across the primary coil 10 and the power consumption. Reference numeral 12 is a receiving means for receiving the 300 MHz radio wave transmitted from the load unit 8. The receiving means 12 receives a 300 MHz radio wave and demodulates it. When the output is 1 kHz, the inverter 13 is continuously operated, and when it is 2 kHz, once every 5 seconds, 200 msec.
The inverter 13 is intermittently operated during the period. The inverter 13 receives the signal from the pan detecting means 11 and supplies a high frequency current of about 25 kHz to the primary coil 10 in response to the signal. Reference numeral 14 is a cooling fan for allowing heat generated by the primary coil 10 and the inverter 13 to escape to the outside of the magnetic field generator 7. Reference numeral 15 is a power cord.

The load section 8 includes the following sections. Reference numeral 16 is a heat generating portion made of magnetic stainless steel that heats water stored inside. Reference numeral 17 is a state in which the load portion 8 is placed on the magnetism generating portion 7, and the primary coil 10 is provided below the heat generating portion 16.
It is a secondary coil that is magnetically coupled with. The diameter of the secondary coil 10 is approximately half the sum of the outer diameter and the inner diameter of the primary coil 10. 18 is a load circuit, and the load circuit 18 is
The transmission means 19, the control circuit 20, the rectifying / smoothing circuit 21, and the thermistor 22 are included. Further, a hot water outlet button 23 for pouring hot water and a hot water outlet 24 are provided.

The high frequency voltage generated in the secondary coil 17 is converted into a direct current by the rectifying / smoothing circuit 21 and supplied to the transmitting means 19, the control circuit 20 and the thermistor 22.
In particular, in this embodiment, the rectifying / smoothing circuit 21 has a built-in large-capacity electric storage device such as an electric double layer capacitor. Therefore, even when the secondary coil receives a high frequency magnetic field for a short time of about 150 msec, the capacitor is charged within that period. Then, for about 7 seconds thereafter, power can be continuously supplied to the transmitting means 19, the control means 20, and the thermistor 22. The control circuit 20 is connected to the thermistor 22, and when the temperature of the thermistor 22 is high and its resistance value is equal to or lower than a predetermined value, it transmits a 2 kHz signal to the transmitting means 19. When the temperature of the thermistor 22 is low and the resistance value is equal to or higher than a predetermined value,
A 1 kHz signal is transmitted to the transmitting means 19. The transmitting means 19 is 1 kHz or 2 k transmitted from the control circuit 20.
A carrier wave of 300 MHz is amplitude-modulated by a signal of Hz and output as a radio wave.

The hot water discharge button 23 pushes the upper part downward to send air into the heat generating portion 16, and the hot water stored is pushed out from the hot water discharge port 24 to the outside by the increase of this pressure.

The operation of this embodiment will be described below. The power cord 15 constituting the magnetic field generator 7 is inserted into an outlet or the like and is operated by a commercial power source. The user places the load unit 8 on the top plate 9 for boiling water. At this moment, the secondary coil 17 is not yet supplied with high-frequency magnetism, and the output of the rectifying / smoothing circuit 21 is zero. Therefore, power is not supplied to the control circuit 20 and the transmission means 19, and the load section 8 does not operate. However, the pot detecting means 11 detects whether or not the pot is placed on the top plate 9, and activates the inverter 13. When the inverter 13 is activated, the pot detecting means 11 outputs a signal according to the presence or absence of a pot to the inverter 13. In the present embodiment, the load portion 8 has a considerably large diameter of the heat generating portion 16, and the pot detecting means 11 makes a determination that “the pot is present”. In addition, when the diameter of the heat generating portion is small, or when the heat generating portion is provided at a position apart from the primary coil 10, the pot detecting means 11 makes a determination of “no pot”. However, even if the pan detecting means 16 determines that there is no pan, the pan 17 signal is sent to the inverter 17 after about 150 msec. As a result, the inverter 17 does not depend on the output of the pan detecting means 16. A high-frequency current will be continuously supplied to the primary coil 10.

That is, first, the high frequency magnetic field generated from the primary coil 10 interlinks with the secondary coil 17, and the secondary coil 1
A high frequency voltage is generated between both terminals of 7. This high frequency voltage is applied to the rectifying / smoothing circuit 21 and converted into a DC voltage. This DC voltage is applied to the transmitting means 19, and the transmitting means 19 starts operating. The transmitting means 19 outputs a radio wave in which a carrier wave of about 300 MHz is amplitude-modulated with a pulse of 3 kHz.
This radio wave is received by the receiving means 12, and this signal is sent to the inverter 13. In this way, the inverter 13 continues to operate. Once such a state is entered, the inverter 13, the rectifying and smoothing circuit 21, the transmitting means 19, the receiving means 12
Continues to operate. Therefore, the heat generating portion 16 is induction-heated by receiving the high frequency magnetic field from the primary coil 10,
The water in it is heated. Here, when the temperature of the water in the heat generating portion 16 is low, the resistance value of the thermistor 22 is high, so the control circuit 20 outputs a signal of 1 kHz to the transmitting means 19. Therefore, the transmitting means 19 outputs a radio wave whose carrier wave of about 300 MHz is amplitude-modulated by a pulse of 1 kHz. This radio wave is received by the receiving circuit 12 of the magnetic field generator 7, and the inverter 13 continues to operate.

When the water temperature in the heat generating portion 16 rises and the resistance value of the thermistor 22 falls below a predetermined value, the control circuit 20
Will send a 2 kHz signal to the transmitting means 19. Receiving means 12 that has received the signal from the transmitting means 19
Demodulates this signal. Since the demodulated signal of the inverter 13 is 2 kHz, once every 5 seconds, 200 msec
It operates intermittently for a while. Here, during the suspension period of the inverter 13, the high-frequency magnetic field is not supplied to the primary coil 10 and the device is suspended. Then, power is supplied to the transmitting means 19 and the control circuit 20 even during the suspension period. Therefore, the control circuit 20
And the transmission means 19 continues to operate. In this way, since the high-frequency current is intermittently supplied to the primary coil 10, the large-capacity storage device is charged during that period, and a voltage above a certain level can be maintained. Note that the induction heating power is intermittently supplied to the heat generating portion 16 as well. The magnitude of the average power supplied at this time is necessary to maintain the water temperature in the heat generating portion 16 in the present embodiment. It is designed to be less than the amount of heat. Therefore, the water temperature in the heat generating portion 16 gradually decreases. When the water temperature drops below the specified temperature,
When the resistance value of the thermistor 22 exceeds a predetermined value, the control circuit 20 outputs the 1 kHz signal to the transmitting means 19 again.
In this way, the receiving means 12 receives the radio wave from the transmitting means 19 again, and the inverter 13 operates again. Therefore, heating in the heat generating portion 16 is also continuously performed. After that, by repeating such an operation, the water temperature in the heat generating portion 16 is maintained at a substantially constant value.

The user can press hot water button 23 as needed to pour hot water from the hot water outlet 24 into a clay bottle, a kyusu, a teacup, a cup type instant noodle, or the like.

Therefore, in the cordless device of this embodiment, the power cord, which was required in the prior art, is eliminated from the load portion, there is no trouble in using the load portion, and it is necessary to dispose of the power cord after use. It can be made clean without any design. Further, as a matter of course, the load section 8 does not require a heater.

Further, in the present embodiment, the power source of the transmitting means 19 and the control circuit 20 uses the voltage generated in the secondary coil 17. Therefore, it is not necessary to use a separate power source such as a dry battery on the load section 8 side. Therefore, maintenance such as battery replacement is unnecessary. Further, since the secondary coil 17 is provided below the heat generating portion 16 and the diameter thereof is approximately half the sum of the outer diameter and the inner diameter of the primary coil 10, power is supplied to the load circuit 18 with a small number of turns. It has the feature of being able to.

The reason for this will be described below with reference to FIGS. FIG. 2 shows a cross section of the primary coil 10 and the secondary coil 17 of the cordless device of FIG. The outer diameter of the primary coil 10 is 180 mm and the inner diameter is 50 mm. The diameter of the secondary coil 17 is half the sum of the two.
It is set to 5 mm. FIG. 3 is a cross-sectional view showing the distribution of magnetic flux around the primary coil 10. As shown in FIG. 3, since the position of the secondary coil 17 is located exactly in the middle of the primary coil 10, the magnetic field lines interlinking with the secondary coil 17 are 4 on each side, that is, 8 lines in total, which is the maximum value. Is becoming In general, the induced voltage in the secondary coil is proportional to the number of magnetic field lines interlinking with the coil, that is, the magnitude of magnetic flux. In this embodiment, since the diameter of the secondary coil 17 is set so that the number of magnetic lines of force generated from the primary coil is maximized, the induced voltage per turn of the secondary coil 17 is the largest. Therefore, the number of turns of the secondary coil 17 required to supply the required voltage to the load circuit 18 can be reduced.

In the prior art, the transmitting means 19
In order to obtain a low-voltage power source for the control circuit 20 and the control circuit 20, it is common to use a large and heavy transformer or an expensive switching power source. In this respect, in the present embodiment, since the power source of the transmitting means 19 and the control circuit 20 is supplied from the secondary coil 17, the structure is simple and the weight, size and cost are excellent, and the control circuit 2
The number of turns of the secondary coil 17 can be freely set to match 0 or the magnitude of the voltage required for the transmitting means 19.

The configuration of this embodiment can be used even with the magnetic field generator 7 alone. That is, the magnetic field generator 7
Instead of the load portion 8 on the top, a enamel pot or the like can be used as a cooking device.

In this case, the operation is as follows. The pot detecting means 11 detects that a pot is present on the top plate 9 and sends this signal to the inverter 13. The inverter 13 operates by receiving this signal, and the primary coil 1
A high frequency current is continuously supplied to 0. In this way, the pot placed on the top plate 9 is induction-heated and cooking can be performed.

When a small metal object is placed on the magnetic field generator 7, no signal is received by the receiving means 12 and the pot detecting means 11 outputs "no pot". Then, the high-frequency current is supplied to the primary coil 10. However, in this state, the heating power of the metal small articles is small, and even if the user touches them, they will not be burned.

In the present embodiment, the transmitting means 19 and the receiving means 12 communicate with each other by radio waves, but the invention is not limited to radio waves, and for example, voice, light, mechanical power, etc. are transmitted. May be. Further, in the present embodiment, the load circuit 18 is provided with a thermistor 22 that detects temperature and communicates with the magnetic field generator 7. However, the load circuit 18 is not limited to communication, and an alarm is emitted or a lamp is turned on. It may be something to wear.

Further, the frequency and the magnitude of the high frequency current supplied to the primary coil may be changed according to the signal from the receiving means. By doing so, it is suitable for the operation of the load section. A high frequency magnetic field can be supplied.

[0027]

As is apparent from the above embodiments, the present invention comprises a magnetism generating part and a load part mountable on the magnetism generating part, wherein the magnetism generating part comprises a top plate,
A metal coil that has a primary coil provided under the top plate and an inverter, and is subjected to induction heating by receiving the magnetic field of the primary coil in a state where the load section is placed on the magnetic field generating section. A heat generating part, a secondary coil provided below the heat generating part, and a load circuit supplied with electric power from the secondary coil, and the diameter of the secondary coil is the outer diameter and the inner diameter of the primary coil. As a cordless device, which is about half of the sum, it is possible to provide a device that is easy to use because the load device does not require a power cord. Further, in particular, by setting the diameter of the secondary coil to approximately half the sum of the outer diameter and the inner diameter of the primary coil, it is possible to effectively supply electric power from the secondary coil to the load circuit.

[Brief description of drawings]

FIG. 1 is a sectional view of a cordless device equipped with a water heater according to an embodiment of the present invention.

FIG. 2 is a partial sectional view of the same primary coil and a secondary coil.

FIG. 3 is an explanatory diagram showing the distribution of magnetic flux around the same primary coil.

FIG. 4 is a cross-sectional view of a conventional jar pot.

[Explanation of symbols]

 7 Magnetic Generation Section 8 Load Section 9 Top Plate 10 Primary Coil 13 Inverter 16 Heat Generation Section 17 Secondary Coil 18 Load Circuit

Claims (1)

[Claims] 1. A magnetism generating part and a load part mountable on the magnetism generating part, wherein the magnetism generating part comprises a top plate, a primary coil provided under the top plate,
An inverter is provided, and the load section is provided on the magnetic field generating section, and is provided below the heat generating section, which is made of metal and is induction-heated by receiving the magnetic field of the primary coil. A cordless device having a secondary coil and a load circuit supplied with electric power from the secondary coil, wherein the diameter of the secondary coil is about half the sum of the outer diameter and the inner diameter of the primary coil.