JPH0568634A - Heating vessel with cover - Google Patents

Abstract

PURPOSE:To eliminate a wiring and an exposed electric contact, and to execute attachment/detachment of a cover body and whole washing, although this vessel consists of a structure in which an electric load such as a heater is fitted in the cover body. CONSTITUTION:In a vessel main body 1, a primary side coil 8, and an oscillator 17 for allowing the primary side coil 8 to generate an alternating field are provided. On the other hand, in a cover body 3, a secondary side coil 11 positioned in a magnetic field of the primary side coil 8, and a load (cover heating heater) 14 connected to the secondary side coil 11 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lid-added heat container such as an electric rice cooker, an electric pot or the like having a removable lid.

[0002]

2. Description of the Related Art Conventionally, for example, some electric rice cookers are provided with a dew-exposing heater on a lid and a lamp for displaying operation during rice cooking or heat retention. Further, a roaster or a fryer having a smoke absorber attached to its lid has been proposed. In the lid-added heat container in which the lid is provided with an electrical load in this way, if the container body is wired to the load of the lid, the lid cannot be attached or detached. Therefore, a rice cooker in which wiring to the heater of the lid is removed and the lid is detachable is proposed in Japanese Utility Model Publication No. 2-14223. In this device, a heater is embedded along the opening edge of the container body, and an inner lid for covering the inner pot accommodated in the container body is provided on the lid body, and the peripheral edge portion of the inner lid is opened at the opening of the container body. The inner lid is brought into contact with the edge to heat the inner lid by heat conduction from the heater.

[0003]

However, in the structure of this conventional rice cooker, the inner lid cannot be heated uniformly, and the inner lid and the opening edge of the container body are formed to raise the temperature of the central portion of the inner lid. Since the temperature of the abutting portion must be raised, there is a problem that the container body becomes abnormally hot. Further, since the contact state of the contact portion between the inner lid and the opening edge of the container body must be ensured, there is a problem that high processing and assembling accuracy is required. An object of the present invention is to solve such a problem, and has a structure in which an electric load such as a heater is attached to the lid body, but there is no wiring or exposed electric contacts, and the lid body can be attached / detached and washed as a whole. It is intended to provide an additional heat container.

[0004]

In order to achieve the above object, the first aspect of the present invention is to provide a container main body with a primary coil and an oscillator for generating an alternating magnetic field in the primary coil. The lid is provided with a secondary coil located in the magnetic field of the primary coil and a load connected to the secondary coil. The second aspect of the invention is that the container body
A lid heating coil and an oscillator for generating an alternating magnetic field in the lid heating coil are arranged, while a heating plate located in the magnetic field of the lid heating coil is arranged in the lid body. ..

[0005]

According to the structure of the first aspect of the present invention, when a high frequency current is passed through the primary coil of the container body by the oscillator, an electromotive current is generated in the secondary coil of the lid by the electromagnetic induction action. As a result, the electromotive current is applied to the load and the load performs a predetermined operation. In this way, since the electric power is exchanged between the lid body and the container body by the electromagnetic induction of the primary coil and the secondary coil, the lead wire and the electrical contact are unnecessary,
The lid can be attached and detached. Further, according to the configuration of the second invention, similarly to the first invention, when a high-frequency current is passed through the lid heating coil by the oscillator, an alternating magnetic field is generated in the lid heating coil and the metal placed in the magnetic field is generated. As a result of the generation of eddy currents in the body, the heating plate is heated by the induction heating action. Therefore, also in the second aspect of the invention, no lead wire or electrical contact is required between the lid and the container body, and the lid can be attached and detached.

[0006]

Embodiments of the present invention will now be described with reference to the drawings. (1) Embodiment of the first invention FIG. 1 shows a rice cooker according to the first invention.
Reference numeral 1 is a container body, 2 is an inner pot, and 3 is a lid. Container body 1
Is composed of a rectangular outer casing 4 and an outer container 5 housed in the outer casing 4. As shown in FIG. 2, a heater 6 is provided on the outer surface of the bottom of the outer container 5, and a pot-shaped core 9 around which a primary coil 8 is wound is provided inside a shoulder portion 7 of the outer casing 4.
A lid opening / closing detection switch 10 is provided. The lid opening / closing detection switch 10 is turned on when a magnet 16 provided on the lid body 3 described later approaches, and is turned off when the magnet 16 is separated from the lid body 3 to close the lid body 3.
The open / close state is detected, but a micro switch can be used instead.

The inner pot 2 is made of metal and is accommodated in the outer container 5 of the container body 1. The lid 3 covers the inner pot 2 of the container body 1, and as shown in FIG.
It is attached to the shoulder portion 7 of the container body 1 so as to be rotatable about the hinge 3a and detachable. Inside the corner of the lid 3, a core 12 around which the secondary coil 11 is wound is provided so as to face the core 9 when the lid 3 is closed. The primary coil 8 and the secondary coil 11 may be air-core coils, but in that case, a ferrite plate may be arranged on the opposite side to the opposite side so that the magnetic flux is concentrated. .. The core 9 and the core 12 are not limited to the pot shape, and may have an E shape.

A heating plate 13 is attached to the lid 3 so as to cover the inner pot 2. A lid heating heater 14 connected to the secondary coil 11 and a temperature sensitive switch 15 are arranged on the back surface of the heating plate 13. The temperature-sensitive switch 15 is for adjusting the temperature, which is turned off when the heating plate 13 reaches a predetermined upper limit temperature and is turned on when the heating plate 13 is below a predetermined lower limit temperature, and a thermostat or the like may be used. Inside the other corner of the lid body 3, as shown in FIG. 2, a magnet 16 is provided which faces the lid opening / closing detection switch 10 when the lid body 3 is closed.

In this rice cooker, an oscillator 17 for the primary coil 8 and a control circuit 18 for controlling the oscillator 17 are provided inside the bottom of the exterior body 4. FIG. 3 shows an electric circuit diagram of this rice cooker. The oscillator 17 includes a rectifier circuit 20 connected to an AC power source composed of four diodes 19 connected in a bridge, a resonance capacitor 21 connected to the rectifier circuit 20, and a switching capacitor connected in series to the capacitor 21. Transistor 22 and a drive pulse oscillation circuit 23 that outputs a transistor drive pulse to the base of the switching transistor 22.

The primary coil 8 is connected in parallel with the capacitor 21 of the oscillator 17 to form an LC resonance circuit. The lid opening / closing detection switch 10 is connected to the control circuit 18. When cooking rice, the control circuit 18 uses the heater 18 based on a rice cooking start switch and an inner pot temperature detecting means (not shown).
When the temperature is maintained, the drive pulse oscillation circuit 23 is controlled based on the signal from the lid opening / closing detection switch 10. On the other hand, in the secondary coil 11 on the lid side,
The lid heating heater 14 and the temperature sensitive switch 15 are connected in series, and a lid heating circuit 24 is formed.

In the rice cooker having the above-described structure, after the rice is cooked by the heater 6, the heat is kept by the heat-retaining heater (not shown). During this heat retention, the control circuit 18
Outputs a drive signal to the drive pulse oscillation circuit 23 of the oscillator 17. As a result, the drive pulse oscillation circuit 23 applies a drive pulse to the base of the transistor 22 to turn on the transistor 22 and, after passing a current through the primary coil 8 for a predetermined time, turns off the transistor 22. As a result, a high-frequency current flows in the primary coil 8 to generate an alternating magnetic field, and an electromotive current flows in the secondary coil 11 placed in this magnetic field due to an electromagnetic induction effect. Then, the electromotive current flows through the heater 14 for heating the lid, so that the heating plate 13 is heated and the dew is prevented from adhering to the heating plate 13. The drive pulse oscillating circuit 23 repeatedly turns on the transistor 22 at a certain point and turns it off after a certain period of time in order to prevent the high frequency current flowing through the primary coil 8 from being attenuated with time. Maintaining current.

When the temperature of the heating plate 13 rises and reaches a predetermined upper limit temperature, the temperature sensitive switch 15 is turned off and the lid heating circuit 2
4 is cut off, heating is stopped, and when the temperature falls to a predetermined lower limit temperature, the temperature sensitive switch 15 is turned on and the lid heating circuit 2
4 is closed and heating continues. In this way, the temperature of the heating plate 13 is adjusted. If the lid body 3 is opened or removed during this heat retention, the magnet 16 is separated from the lid opening / closing detection switch 10 and the lid opening / closing detection switch 10 is turned off. As a result, the control circuit 18 causes the lid opening / closing detection switch to move. Based on the OFF signal from 10, the stop signal is output to the drive pulse oscillation circuit 23 of the oscillator 17. As a result, the oscillation of the oscillator 17 is stopped and the magnetic field of the primary coil 8 is demagnetized. Therefore, even if a user places a metal object such as a spoon on the primary coil 8 with the lid open, the metal object is not heated by the induction heating action.
It's safe.

In the above embodiment, the inner pot 2 is heated by the heater 6 as shown in FIG.
The induction coil 26 may be arranged below the outer container 5 and heated by induction heating by the induction coil 26. In this case, as shown in FIG. 4, the rice cooker induction coil 26 and the lid heating primary side coil 8 are connected to the oscillator 17 via the switching circuit 25 that operates based on the switching signal from the control circuit 18. According to this, the control circuit 18
Switches the switching circuit 25 to the induction coil 26 side during rice cooking, and causes the induction coil 26 to generate an alternating magnetic field. As a result, an eddy current is generated in the inner pot 2 due to the induction heating action, and the inner pot 2 generates heat due to its electric resistance, so that the rice is cooked. When the rice cooking is completed, the control circuit 18 switches the switching circuit 25.
Is switched to the primary coil 8 side. As a result, in the same manner as described above, an electromotive current is generated in the secondary coil 11 by the electromagnetic induction action, the lid heating heater 14 generates heat, and the heating plate 13 is heated, so that dew adhesion is prevented.

FIG. 5 shows another embodiment of the first invention. The primary coil 8 is provided on the outer periphery of the upper end of the outer container 5,
The secondary coil 11 is provided on the outer periphery of the heating plate 13 so as to face the primary coil 8. Further, although the primary coil 8 is air-core, ferrite 27 is disposed below as shown in FIG. 6 so that the magnetic flux is concentrated. The circuit configuration and operation are the same as those in the above-mentioned embodiment, and the explanation is omitted. This coil arrangement is particularly effective when the container body 1 is round.

Although the above embodiment is the rice cooker in which the lid heating heater 14 is arranged on the lid 3 as an electric load, the first invention is not limited to this, and the lid 3 is electrically charged. The present invention can also be applied to a rice cooker provided with LEDs for operation display during rice cooking or heat retention as a load, a cooker provided with a stirrer, a roaster provided with a smoke absorber, and the like. That is, by connecting these electrical loads to the secondary coil,
Since the loads can be operated and there is no connection, the lid body to which the loads are attached can be easily removed.

In the embodiment of the first invention (FIG. 3), the impedance of the primary coil 8 is measured to detect whether the load on the lid side (heater 14 for heating the lid) is on or off, and the load is detected. The drive pulse oscillation circuit 23 may be stopped at the time of turning off to reduce power consumption and protect the oscillation circuit 17.

(2) Embodiment of Second Invention FIGS. 7 and 8 show an induction heating rice cooker according to a second invention of the present invention, wherein the rice cooker of the first invention is an outer container 5
The induction coil 26 for cooking rice is arranged on the outer surface of the bottom of the
Substantially the same except that the lid heating coil 31 is provided in the container body 1 and the first heating plate 32a and the second heating plate 32b are provided in the lid body 3, and the same symbols are given to corresponding parts. Is attached. As shown in FIG. 8, the lid heating coil 31 is provided inside the shoulder portion 7 of the container body 1 and on the outer periphery of the upper end of the outer container 5, and a magnetic flux is provided below the lid heating coil 31. A ferrite plate 33 for concentrating is arranged. On the other hand, the first heating plate 32a is an annular member made of an iron-based metal such as stainless steel, and is arranged inside the lid 3 so as to face the lid heating coil 31.
A second heating plate 32b made of aluminum is joined to the first heating plate 32a, and an inner lid 34 that covers the inner pot 2 is attached to the center of the second heating plate 32b.

FIG. 9 is an electric circuit diagram of the induction heating rice cooker according to the second aspect of the present invention, which is different from the electric circuit diagram of the rice cooker of the first aspect of the invention in that the lid side does not have a lid heating circuit. Since the lid heating coil 31 is connected instead of the coil and the switching circuit 25 for switching the lid heating coil 31 and the rice cooking induction coil 26 is provided, the same reference numerals are given. In this rice cooker, after the rice is cooked, when a high-frequency current flows in the lid heating coil 31 and an alternating magnetic field is generated in the same manner as described above, the induction heating action causes
Eddy current is generated in the first heating plate 32a, and its electrical resistance causes the first heating plate 32a to generate heat. As a result, the heat of the first heating plate 32a is transferred to the second heating plate 32b by heat conduction,
The second heating plate 32b and the inner lid 34 are heated. This prevents the dew on the second heating plate 32b and the inner lid 34.

Also in this second invention, when the lid is opened,
Since the lid opening / closing detection switch 10 detects the opening of the lid 3 and stops the oscillator 17, even if a metal object is placed on the shoulder 7 of the container body 1, the metal object does not generate heat. , Safe. Instead of providing the first heating plate 32a and the second heating plate 32b as in the above-described embodiment,
The second heating plate 32 is formed by making the heating plate 32a circular rather than annular.
You may make it serve also as b. It is also possible to omit the inner lid 34 and cover the inner pot 2 with the second heating plate 32b. Further, the second invention is similar to the first embodiment of the first invention, except for the induction heating rice cooker that uses the induction coil 26 to heat the inner pot 2 as in the first embodiment. It can also be applied to jars. In this case, the switching circuit 25 becomes unnecessary.

In the embodiment of the first invention (FIG. 3), the temperature of the lid 3 is controlled by the temperature sensitive switch 15. However, by providing the temperature detecting sensor on the container body side, the temperature detected by the temperature detecting sensor can be controlled. Based on the drive pulse oscillation circuit 23
May be driven and stopped. Further, also in the embodiment of the second invention (FIGS. 8 and 9) in which the temperature control means is not provided, the temperature of the lid 3 can be controlled in the same manner.

[0021]

As is apparent from the above description, according to the invention of claim 1, a current is supplied to the load of the lid by the electromagnetic induction effect, and according to the invention of claim 2, the induction heating effect. Since the heating plate of the lid body is heated by, the lead wire is not required between the lid body and the container body, and the lid body can be removed, and the electrical contacts and the like are not exposed on the lid body. It is possible to wash the whole. Even if there is a gap of several millimeters between the lid and the container body, the load on the lid can be operated and the heating element is heated. Is not strictly required, and processing and assembly work is simplified. Furthermore, in an induction heating rice cooker having an induction coil for cooking rice and an oscillator in the container body, the oscillator can be used for electromagnetic induction of the secondary coil of the lid or for induction heating of the heating plate of the lid. The circuit of the oscillator is made common, and it has the effects of being inexpensive and compact.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a rice cooker according to a first embodiment of the first invention.

2 is a cross-sectional view of the rice cooker of FIG.

FIG. 3 is an electric circuit diagram of the rice cooker of FIG. 1.

FIG. 4 is a block diagram of an induction heating rice cooker in which the induction coil for rice cooking and the primary coil for heating the lid have the same oscillator.

FIG. 5 is an exploded perspective view of a rice cooker according to a second embodiment of the first invention.

6 is a partial cross-sectional view of FIG.

FIG. 7 is an exploded perspective view of a rice cooker according to a second invention.

8 is a cross-sectional view of the rice cooker of FIG.

9 is an electric circuit diagram of the rice cooker of FIG. 7. FIG.

[Explanation of symbols]

1 ... container body, 3 ... lid body,
5 ... Outer container, 8 ... Primary coil, 11 ... Secondary coil, 13 ... Heating plate, 14 ... Lid heating heater (load), 17 ... Oscillator, 31 ... Lid heating coil, 3
2a, 32b ... First and second heating plates.

Claims (2)

[Claims] 1. A container main body is provided with a primary coil and an oscillator for generating an alternating magnetic field in the primary coil, while a lid is located within the magnetic field of the primary coil. Two
A lid-added heat container comprising a secondary coil and a load connected to the secondary coil. 2. A lid heating coil and an oscillator for generating an alternating magnetic field in the lid heating coil are provided in the container body, while the lid body is positioned within the magnetic field of the lid heating coil. A lid-added heat container having a heating plate.