JP2755188B2 - Electric rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric rice cooker,
More specifically, the present invention relates to an electric rice cooker having a structure in which steam generated during rice cooking is not discharged to the outside.

[0002]

2. Description of the Related Art Generally, in an electric rice cooker, a large amount of steam is generated at the time of cooking rice. Therefore, a steam discharge passage is formed in a lid to discharge the steam to the outside, and the steam is discharged through the steam discharge passage. It is said that the steam is discharged to the outside.

[0003] By the way, there are cases where the user uses the electric rice cooker on various floors (for example, on a tatami mat) where an infant can reach the electric rice cooker. Risk of burns.

[0004] Therefore, the electric rice cooker is housed in a storage to be used, so that the accident in the above-mentioned usage form can be prevented, and the steam is cooled in the storage to be recovered as water. Such a configuration has been proposed (for example, see Japanese Utility Model Laid-Open No. 1-171239).

[0005]

However, in the case of the above-mentioned known example, even if water vapor is recovered as water in the storage, not only may the inside of the storage become wet, but also after the rice cooking is completed, the storage may be stopped. There is a trouble in using that the electric rice cooker has to be taken out from the storage. It is ideal for a user to be able to eat as it is after cooking rice, and development of an electric rice cooker having a structure in which steam is not discharged to the outside even during cooking is awaited.

[0006] The present invention has been made in view of the above points, and has as its object to prevent water vapor from being discharged to the outside even during rice cooking.

[0007]

According to the basic structure of the present invention, a container body having an electromagnetic induction coil for heating an inner pot housed therein and an upper portion of the container body are provided as means for solving the above-mentioned problems. A lid having an opening and a cover that can be freely opened and closed and having a vapor discharge passage for discharging water vapor generated during rice cooking to the outside. While providing a steam outlet passage leading to the, while providing a condenser for cooling the steam, in the space in the container body, disposing a cooling fan for blowing air to the condenser,
A heating element is provided between the cooling fan and the condenser to control current to the electromagnetic induction coil.

[0008]

According to the basic structure of the present invention, the following effects can be obtained by the above means.

That is, a large amount of water vapor generated during cooking rice reaches the condenser through the vapor outlet passage, is pressure-fed from a cooling fan, and is condensed and liquefied by heat exchange with cooling air after cooling the heating element. Most of it is water.

[0010]

According to the present invention, a large amount of water vapor generated during rice cooking is guided to the condenser through the vapor outlet passage, is pressure-fed from the cooling fan, and is cooled by the cooling air and heat after cooling the heating element. Since it is made to exchange and condense and liquefy and recover most as water, there is no risk of causing an accident such as a burn in any use form of the user, and it is possible to avoid an increase in moisture by discharging a large amount of water vapor, There is an excellent effect that both the heating element and the condenser can be cooled by one cooling fan.

[0011]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

The electric rice cooker of this embodiment is of a high-frequency electromagnetic induction type using an electromagnetic induction coil as an inner pot heating means, and is configured to be able to serve both rice cooking and heat retention. Can of course be applied to those using an electric heater as the inner pan heating means.

As shown in FIG. 1, the electric rice cooker is configured so that an inner pot 3 can be set therein, and a space 4
And a lid 2 for opening and closing the upper opening of the container main body 1 in an openable and closable manner.

The container body 1 has a bottomed cylindrical outer case 5 made of a synthetic resin forming an outer wall and a bottom wall, and a bottomed cylindrical inner case 6 made of a synthetic resin forming an inner peripheral surface. And a synthetic resin shoulder member 7 for joining the upper ends of the two cases 4 and 5. The space portion 4 is formed by being surrounded by the outer case 5, the inner case 6 and the shoulder member 7. I have. Note that the inner pan 3 is set in the inner case 6 so as to be removable.

At the center of the bottom surface of the inner case 6, a sensor hole 9 for receiving a center sensor 8 is formed, and an annular electromagnetic induction coil 10 is surrounded by the inner case 6 so as to surround the sensor hole 9. It is arranged on the bottom surface of. The electromagnetic induction coil 10 functions as a heating unit for heating the inner pot 3. This electromagnetic induction coil 10
Is sandwiched between a ferrite core 12 fixed to the bottom surface of the inner case 6 by screws 11 and a bottom surface of the inner case 6, and the ferrite core 12 is magnetized by the electromagnetic induction coil 10 downward. It also acts as a shield so as not to affect existing equipment.

A cylindrical portion 12a corresponding to the sensor hole 9 is formed at the center of the ferrite core 12, and a center sensor that contacts the bottom surface of the inner pot 3 is formed in the cylindrical portion 12a. 8 are provided.

The center sensor 8 functions as temperature detecting means for detecting the temperature of the inner pot 3, and detects whether or not the thermistor 13 serving as a temperature detecting unit and the inner pot 3 are set. It is provided with a pan set detection sensor 14. And this center sensor 8
Is a sensor holder 15 which is disposed inside the cylindrical portion 12a so as to be vertically movable and incorporates the thermistor 13, and the sensor holder 15 is moved upward (that is, in a direction in which it comes into contact with the bottom surface of the inner pot 3). And a spring 16 that urges the spring. The inner pan set detection sensor 14 is composed of a reed switch and a magnet (not shown). The reed switch is turned ON when the sensor holder 15 is lowered by setting the inner pan 3.

Below the ferrite core 12, there is provided a power supply board 17 which transmits and receives signals to and from various electric elements while being supported by the ferrite core 12. The substrate 17 includes the electromagnetic induction coil 1.
A power transistor 18 for controlling the current to zero and a rectifying diode bridge 19 are also mounted. The power transistor 18 and the rectifying diode bridge 19 are heating elements that generate heat during operation.

A cooling fan 20 is provided below the power supply board 17 while being supported by the ferrite core 12. The cooling fan 20 sends cooling air F to the power transistor 18 and the rectifying diode bridge 19 under pressure, and includes a fan motor 21 and an axial impeller 22 driven to rotate by the fan motor 21. I have.

On the bottom wall of the container body 1 (specifically, on the bottom surface of the outer case 5), a cooling air inlet 23 is formed to face the cooling fan 20, while the outer wall of the container body 1 is formed. (Specifically, a cooling air outlet 24 is formed in the side peripheral surface of the outer case 5). In the space 4 of the container body 1, a condenser 25 for condensing water vapor (which will be described in detail later) is provided so as to face the cooling air outlet 24. Therefore, the cooling air F sucked from the cooling air inlet 23 by the cooling fan 20 cools the power transistor 18 and the rectifying diode bridge 19, and then cools the condenser 25.
Is cooled and then discharged to the outside from the cooling air outlet 24. The condenser 25 is disposed at a position corresponding to a non-operating portion (that is, a portion excluding a rear hinge pivot portion and a front lock operating portion of the lid 2) in the space portion 4 of the container body 1.

On the other hand, the lid 2 is made of a synthetic resin upper plate 26 constituting the outer surface, a synthetic resin lower plate 27 constituting the inner peripheral surface, and a metal plate attached to the lower surface of the lower plate 27. Of the upper and lower plates 2
A hollow portion 29 is formed between 6 and 27.

The lid 2 is rotatably attached to one side of the shoulder member 7 via a hinge mechanism (not shown).

At the center of the lid 2, a lower tubular portion 30 erected from the lower plate 27 and an upper tubular portion 31 erected from the upper plate 26 are joined. A steam discharge passage 32 is formed. The steam discharge passage 32 is for discharging steam S generated during cooking rice to the outside.

The radiator plate 28 is provided with the steam discharge passage 3.
2, a hole 33 corresponding to the lower end is formed.
Is wrapped around the lower edge of the radiator plate 28 so that the radiator plate 28 is supported by the lower plate 27.
Further, when the lid 2 is closed, the outer peripheral edge of the heat radiating plate 28 is pressed against a shoulder heater 34 provided on the inner peripheral edge of the shoulder member 7. Accordingly, the heat radiating plate 28 is heated by the heat transfer from the shoulder heater 34. Reference numeral 35 denotes a seal packing for maintaining airtightness between the heat radiating plate 28 and the upper edge of the inner pot 3, and reference numeral 36 denotes an elastic member for urging the outer peripheral side of the heat radiating plate 28 downward.

In the hole 33 of the heat radiating plate 28, an oneva reservoir 37 for retaining oneva discharged together with the water vapor S is supported on the inlet side of the steam discharge passage 32. The oneva reservoir 37 is provided between a pressure regulator 37a made of silicon rubber which is locked in the hole 33 and an outer periphery of the pressure regulator 33, and is connected between the lower surface of the heat sink 28 and the pressure regulator 37a. And an opening 38 serving as an inlet for water vapor S is formed in the oneva receiver 37b, while the one pressure chamber 37a has an oneva inside. Oneva return hole 39 for returning to pot 3 and communication hole 4 for guiding water vapor S to vapor discharge passage 32
0 is formed.

A steam outlet passage 41 is provided which branches off from the steam discharge passage 32, passes through the hollow portion 29 in the lid 2, and is connected to the condenser 25 in the space 4 in the container body 1. ing. One end of the steam outlet passage 41 is connected to a branch port 42 formed in the lower cylinder portion 30, and a lid-side connection port formed on the outer peripheral edge of the lid lower plate 27 through the lid hollow portion 29. A lid-side steam outlet pipe 44 having the other end connected to 43 and a main-body-side connection port 45 connected to the lid-side connection port 43 and formed in the shoulder member 7 so as to face the lid-side connection port 43. On the other hand, the connecting pipe 4 is communicated when the lid 2 is closed, and is not communicated when the lid 2 is opened.
6 and a main body side steam outlet pipe 47 having one end connected to the main body side connection port 45 and the other end connected to the inlet of the condenser 25. The connecting pipe 46 is made of a material that can be elastically deformed so that it can be pressed against the edge of the main body side connection port 45 in an elastically deformed state when the lid 2 is closed.

The steam discharge passage 32 is provided with passage switching means 48 for switching the flow of steam to the steam discharge passage 32 or to the steam discharge passage 41.

The passage switching means 48 includes a valve element 50 for opening and closing a valve seat 49 formed above the branch port 42 in the lower cylindrical portion 30, and a valve operating mechanism for opening and closing the valve element 50. 51 and the valve operating mechanism 51
The cam piece 52 fixed to the upper end of the valve rod 50a of the valve body 50, the operation cam 53 slidably abutting on the cam piece 52, and the cam piece 52 And a spring 54 that urges in the valve direction. Reference numeral 71 denotes a spring receiver.

The operation cam 53 is slidably supported in the direction of arrow A or B with respect to the outlet 32a of the steam discharge passage 32, as shown in an enlarged view in FIG.
The cam engaging portion 53a and the cam engaging portion 52a of the cam piece 52
Is engaged, the valve body 50 moves upward as shown by a chain line to open the valve seat 49. In the case of the present embodiment, when the valve body 50 is closed, all of the discharged steam S flows to the steam outlet passage 41, the steam discharge from the steam discharge passage 32 stops, and when the valve body 50 is opened. In, the discharged steam S can flow through both the steam discharge passage 32 and the steam discharge passage 41, but most of the discharged steam S flows through the steam discharge passage 32 having a short passage length.

The condenser 25 has one side open, and an upper opening 57 serving as an inlet for steam S, a lower opening 58 serving as an outlet for condensed and liquefied recovered water W, and an unrecovered steam S. A condenser main body 55 having a discharge port 59 for discharging and a plurality of ribs 61 forming a meandering passage 60 extending from the upper opening 57 to the lower opening 58 (see FIG. 3).
And a heat radiating plate 56 fixed to the condenser main body 55 with screws 62.

The condenser body 55 and the radiation plate 5
6 is an integrally molded product of an aluminum alloy which is a good thermal conductor,
The radiating plate 56 has a number of radiating fins 63, 63.
・ Is integrally molded. The radiation fins 63, 63,.
Are horizontal fins, and the length thereof is reduced from the top to the bottom. As a result, the cooling air F sent from the cooling fan 20 can be efficiently brought into contact with all the radiating fins 63. Reference numeral 64 denotes a gasket interposed between the condenser main body 55 and the heat radiation plate 56, and reference numeral 65 denotes a boss for attaching the screw 62.

Further, in the container body 1, an outer case 5 is provided below a place where the condenser 25 is provided.
A recess 66 is formed by recessing a part of the recovery tank 67. In the recess 66, an open-top recovery tank 67 for storing the recovery water W condensed and liquefied in the condenser 25 is formed. Is detachably stored. The lower opening 58 of the condenser main body 55 penetrates the outer case 5 and faces above the recovery tank 67.

As shown in FIG. 4, the recovery tank 67 includes a tank main body 67 having a rectangular cross section and a tank main body 6.
7, a vertically extending protruding portion 67 integrally formed at the rear portion.
b), and has a volume capable of accommodating the recovered water W recovered by cooking rice three times.

On both sides of the ridge 67b, a water level sensor 6 for detecting a storage limit water level L (for example, a water level when the recovered water W collected by cooking rice twice is stored) is provided.
8 are provided. The water level sensor 68 is a photocoupler including a light emitting element 68a and a light receiving element 68b which are arranged on both sides of the recovery tank ridge 67b so as to face each other. The light-emitting element 68a and the light-receiving element 68b are connected to the power supply board 17 described above, detect a storage limit water level L, output a detection signal, and are provided, for example, at an appropriate position in the container body 1 as described later. An alarm buzzer 69 and an alarm lamp 70 (see FIG. 5) serving as alarm means are operated.

Next, an electric configuration of the electric rice cooker according to the present embodiment will be described with reference to an electric circuit diagram shown in FIG. Parts corresponding to the respective parts shown in FIG. 1 are denoted by the same reference numerals.

The electric power from the commercial AC power supply 72 is supplied to the shoulder heater 34 and the cooling fan 20 via the temperature fuse 73 that detects and melts the abnormal heating of the inner pot 3, and is stepped down by the step-down transformer 74. The power is rectified by the rectifier 75 and supplied to the microcomputer unit 76 as its power supply power. The electric power from the commercial power supply 72 is supplied to the electromagnetic induction coil 10 via the rectifying diode bridge 19 and the choke coil 77. Further, the electromagnetic induction coil 10, the shoulder heater 34 and the cooling fan 20
Are connected in parallel with each other. Reference numerals 78 and 79 are smoothing capacitors, 80 is a resonance capacitor, and 81 is a diode.

A triac 82 is connected between the shoulder heater 34 and the commercial AC power supply 72. The gate of the triac 82 has a PN that is ON / OFF controlled by a command from the microcomputer unit 76.
A control signal from P transistor 83 is to be applied. The electromagnetic induction coil 10 is turned ON / OFF by a command from the microcomputer unit 76.
A control signal from the power transistor 18 to be turned off is supplied.

The microcomputer unit 76
Operates based on a clock signal from a reference frequency generation circuit (OSC) 84, controls the power transistor 18 and the transistor 83 according to a predetermined program, and thereby controls the electromagnetic induction coil 10 and the shoulder heater 34.
To control the energization of This energization control is performed based on an output signal from a thermistor 13 built in the center sensor 8. Reference numeral 85 denotes switches, 86 denotes a timer setting display, and 87 denotes a liquid crystal display.

The microcomputer unit 76 includes control means for operating an alarm buzzer 69 and an alarm lamp 70 as alarm means in response to a detection signal of the water level sensor 68. Note that the microcomputer unit 76 also includes functional means for controlling power supply to the electromagnetic induction coil 10 during rice cooking, controlling power supply to the electromagnetic induction coil 10 according to a rice cooking menu, and the like.
A description of these controls will be omitted.

Next, the operation of the electric rice cooker of this embodiment will be described.

For example, when cooking rice without discharging water vapor according to the user's request, the operation cam 53 of the passage switching means 48 is slid in the direction of arrow A, and the valve body 50 is moved.
Is seated on the valve seat 49. Then, the steam S generated at the time of cooking rice is guided to the condenser 25 through the steam outlet passage 41, and is sent under pressure from the cooling fan 20 in the condenser 25,
The heat is exchanged with the cooling air F after cooling the power transistor 18 and the rectifying diode bridge 19 to condense and liquefy, and is collected as collected water W in the collection tank 67. In the condenser 25, most of the steam S is condensed and liquefied, but a small amount of unrecovered steam is discharged from the outlet 59 through the container body 1.
The air is discharged to the internal space 4 and is discharged to the outside from the cooling air outlet 24 together with the cooling air W. Since the discharged air is warm air containing a small amount of water vapor S, there is no danger of burns or the like, and there is no possibility of increasing humidity.

When the user desires to select a use mode in which the water vapor S is discharged, the operation cam 53 of the passage switching means 48 is slid in the direction of the arrow B fully, and the operation engagement of the operation cam 53 is performed. When the portion 53a and the cam engaging portion 52a of the cam piece 52 are engaged, the valve body 50
The valve seat 49 is opened and the steam discharge passage 32 is opened as shown by a chain line in FIG. In this state, the steam S generated during cooking rice can flow through both the steam discharge passage 32 and the steam outlet passage 41, but most of the steam S flows through the short steam discharge passage 32. It will be discharged from the outlet 32a to the outside. Also in this case, the cooling air outlet 24
The cooling air F that has cooled the power transistor 18 and the rectifying diode bridge 19, which are heating elements, is exhausted from the heater.

When the collected water W is collected in the collection tank 67 every time rice is cooked as described above, the collection tank 6
In this embodiment, when the water level sensor 68 detects the water level of the collected water W collected by cooking the rice twice (that is, the storage limit water level L), an alarm buzzer 69 and an alarm are issued. The lamp 70 is to operate. Therefore, the alarm control will be described in detail below with reference to the flowchart shown in FIG.

The cooking switch (not shown) in step S ₁ is made is discriminated whether the ON operation, and if an affirmative decision is made, ON determination of the water level sensor 68 is made in step S _2. Here, if an affirmative determination is made, the alarm buzzer 69 at step S ₃ is sounded operated at 5 second intervals, the alarm lamp 70 is blinking in step S _4, and then returns to step S _1. Accordingly, the user is warned that the recovery water W may overflow from the recovery tank 67 if the rice cooking is directly performed.
Therefore, if the user discards the collected water W in the collection tank 67 before performing the rice cooking and resets the collection tank 67, the overflow of the collected water W can be prevented. The above warning is continued until the recovery tank 67 is reset, but when the recovery tank 67 is reset, the water level sensor 68 is naturally turned off.

[0045] When a negative determination is made in step S ₂ (i.e., when the water level of the recovered water W is lower than the accommodation limit water level L) in is turned off the alarm lamp 70 in step S _5, the cooking performed in step S ₆ You. ON determination of the water level sensor 68 is made in a subsequent step S ₇ in cooking execution, if an affirmative determination, the warning lamp 70 is turned on in step S _8, after attention to the user, the process returns to step S ₆ . In this case, the amount of the recovered water W recovered by the current rice cooking is determined by the recovery tank 67.
Although the collected water W does not overflow from, it may overflow at the next rice cooking, so that the user's attention is urged. When a negative determination is made in step S _7,
After turning off the warning lamp 70 and returns to step S _5, the subsequent processing is performed.

In the case of an electric rice cooker, the cooling fan 20 is not provided, but the condenser 25 is provided with a cooling air inlet 23.
From the air to the cooling air outlet 24, and condensed and liquefied water vapor S can be sufficiently achieved.

The present invention is not limited to the configuration of the above-described embodiment, and it is needless to say that the design can be changed without departing from the gist of the invention.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electric rice cooker according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of a lid of the electric rice cooker according to the embodiment of the present invention.

FIG. 3 is a front view of a condenser main body constituting the condenser in the electric rice cooker according to the embodiment of the present invention.

FIG. 4 is an enlarged sectional view taken along the line IV-IV of FIG. 1;

FIG. 5 is an electric circuit diagram showing an electric configuration of the electric rice cooker according to the embodiment of the present invention.

FIG. 6 is a flowchart showing alarm control of the electric rice cooker according to the embodiment of the present invention.

[Explanation of symbols]

1 is a container body, 2 is a lid, 3 is an inner pot, 4 is a space, 5 is an outer case, 6 is an inner case, 10 is a heating means (electromagnetic induction coil), 18 is a heating element (power transistor), 19
Is a heating element (rectifier diode bridge), 20 is a cooling fan, 23 is a cooling air inlet, 24 is a cooling air outlet, 25 is a condenser, 32 is a steam discharge passage, 41 is a steam outlet passage,
2 is a branch port, 43 is a lid side connection port, 44 is a lid side steam outlet pipe, 45 is a main body side connection port, 46 is a connection pipe,
7 is a main body side steam outlet pipe, 48 is a passage switching means, 67
Is a recovery tank, 68 is a water level sensor, 69 is alarm means (alarm buzzer), 70 is alarm means (alarm lamp), 76
Is a microcomputer unit, F is a cooling wind, L is a storage limit water level, S is steam, and W is recovered water.

Claims (1)

(57) [Claims] 1. A electromagnetic induction to heat the pot inner contained therein
An electric rice cooker comprising: a container body having a conductive coil ; and a lid body that covers an upper opening of the container body so as to be openable and closable and has a steam discharge passage for discharging steam generated during rice cooking to the outside. While providing a steam outlet passage for guiding steam generated at the time to the space of the container body through the lid, a condenser for cooling the steam is provided in the space of the container body. , Blown to the condenser
The cooling fan and the condenser
Between the control and the current controlling the current to the electromagnetic induction coil.
An electric rice cooker comprising a heat element .