JP3374758B2 - Electromagnetic 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 electromagnetic rice cooker configured to heat an inner pot by high frequency electromagnetic induction by an electromagnetic induction coil.

[0002]

2. Description of the Related Art In recent years, an electromagnetic rice cooker employing a high frequency electromagnetic induction heating device as a heating means for heating an inner pot has been developed. In the case of the electromagnetic rice cooker, the Joule heat generated by the eddy current generated in the inner pot by the high frequency electromagnetic induction by the electromagnetic induction coil is used for heating the inner pot.

By the way, in the case of an inner pot for an electromagnetic rice cooker, it is necessary to employ a material having a high electric resistance with respect to an eddy current generated by high frequency electromagnetic induction as a material of the inner pot.
Since the electromagnetic induction coil is arranged corresponding to the bottom of the inner pot, the material that has high heat transfer performance to the upper part of the inner pot (in other words, good conductor of heat) is disadvantageous in terms of uniform heating. There is a request to do.

As a technique satisfying the above requirements, an inner pot is made of an aluminum alloy which is a good conductor of heat but a non-magnetic material, and the outer peripheral surface of the inner pot is protected against eddy currents generated by high frequency electromagnetic induction. It has been proposed that an iron-based sprayed layer having a high electric resistance is formed (for example, JP-A-8-1408).
32).

[0005]

However, in the case of the above-mentioned known example, since the surface of the sprayed layer is a rough surface with a rough surface, when the inner pot is placed, a mating member (for example, a sink, etc.) However, the current situation is that it has not been put into practical use.

[0006] Recently, attempts have been made to positively promote convection generated in the inner pot during rice cooking by making the bottom surface of the inner pot upwardly curved.
When the thermal spray layer is formed on the outer peripheral surface of the inner pot having such a shape, the following problems occur.

The thickness of the sprayed layer is not always constant because it is easily influenced by various requirements. For example, in the case of an electromagnetic rice cooker in which the inner pot is placed inside the rice cooker body, the ground plane is used. If the thickness of the sprayed layer at is not constant,
When the inner pot is housed in the rice cooker body, the gap between the electromagnetic induction coil and the sprayed layer may not be as designed. Then, the eddy current generated by the high frequency electromagnetic induction by the electromagnetic induction coil becomes strong and weak, which causes non-uniform heating.

The present invention has been made in view of the above points, and improves the heat transfer performance and the high frequency electromagnetic induction heating performance of the inner pot, and at the same time, damages the counterpart member when the inner pot is placed. The purpose is to ensure that the gap between the electromagnetic induction coil and the sprayed layer is secured as designed.

[0009]

According to the invention of claim 1,
As a means for solving the above problems, an electromagnetic induction coil is used.
Electromagnetic rice cooker that heats the inner pot by high frequency electromagnetic induction
In the inner pot,Made of non-magnetic material,Center
ButCurved upwardsThe bottom surface and the side surface
With a curved surface that continuesWith the shape,The aboveInner pot
The outer surface of the bottom surface and the outer surface of the curved surface in
And the ground surface part and the part of the bottom surface excluding the central outer surface
In addition, a high voltage is applied to the eddy current generated by high frequency electromagnetic induction.
A thermal spray layer made of magnetic metal material showing air resistanceEachform
SuccessOn the other hand, the outer bottom surface of the inner pot and the outer side from the outer bottom surface
The shape corresponding to the curved surface facing the surface and along the sprayed layer
Bottom side and side electromagnetic induction coils
PlaceTo improve high-frequency electromagnetic induction heating performance and heat transfer performance.
Along with making efforts, even when the inner pot is placed, the mating member
I try not to hurt them. Only
Even when the inner pot is stored in the rice cooker body,
A sprayed layer that is difficult to keep constant is not formed on the ground plane
From the beginning, design the spacing between the electromagnetic induction coil and the sprayed layer
Can be secured in the streetAnd the electromagnetic induction coil and thermal spraying
It means that the space between the layers can be made almost equal,
Uniform heating is possible. Also, the bottom of the electromagnetic induction coil
Place the upper part above the lowermost part of the electromagnetic induction coil on the side surface side.
Position it and place it in the inner pot by the electromagnetic induction coil on the bottom side.
Due to slewing convection and electromagnetic induction coil on the side surface,
Good balance with slewing convection and good rice cooking
I am trying.

In a second aspect of the present invention, as means for solving the above problems, in an electromagnetic rice cooker for heating an inner pot by high frequency electromagnetic induction by an electromagnetic induction coil, the inner pot is made of a non-magnetic material. , the central portion of the curved upwards
A curved bottom surface and a curved surface continuous from the bottom surface to the side surface.
Together form a shape having, on an outer bottom surface and an outer surface of the inner bowl to form a sprayed layer made of a magnetic metal material having a high electrical resistance to eddy current generated by high frequency electromagnetic induction and the inner bowl in solution picolinimidate Ground plane part and the bottom surface
The central part of the inner pot is formed into a smooth surface, while the outer bottom surface of the inner pot is
And a curved surface from the outer bottom surface to the outer surface, and
Electromagnetic induction on the bottom side and side sides along the sprayed layer
By arranging the conducting coils respectively , the high-frequency electromagnetic induction heating performance and the heat transfer performance are improved, and even when the inner pot is placed, the counterpart member is not damaged. Moreover, even when the inner pot is stored in the rice cooker main body, the smooth surface can have a constant thickness, so that the gap between the electromagnetic induction coil and the sprayed layer can be secured as designed , and the electromagnetic induction Coil and sprayed layer
Since the intervals can be made almost equal, uniform
Can be heated. Also, the top of the electromagnetic induction coil on the bottom side
Is located above the bottom of the electromagnetic induction coil on the side.
Then, it is generated in the inner pot by the electromagnetic induction coil on the bottom side.
Generated in the inner pan by convection and electromagnetic induction coil on the side
Good balance with convection and good rice cooking
I have to.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

First Embodiment FIGS. 1 to 4 show an electromagnetic rice cooker according to a first embodiment of the present invention.

This electromagnetic rice cooker is used for both rice cooking and heat insulation, and as shown in FIG.
A rice cooker main body 1 having a double structure configured so that the rice cooker can be set, and a lid 2 that covers an upper opening of the rice cooker main body 1 so as to be openable and closable.

The rice cooker body 1 has a bottomed cylindrical outer case 4 made of synthetic resin which constitutes the bottom and outer peripheral surfaces, a synthetic resin protective frame 5 which constitutes the inner peripheral surface, and an outer case 4. It is configured by a shoulder member 6 made of a synthetic resin that is connected to the upper end of the protective frame 5, and the inner pot 3 is placed in the inside so that it can be taken out.

The lid 2 has an upper plate 7 made of synthetic resin forming an upper surface, a lower plate 8 made of synthetic resin forming an outer peripheral annular portion on the lower surface, and heat for covering an opening in the lower plate 8. A heat dissipation plate 9 made of a good conductor (for example, an aluminum alloy) is formed into a hollow structure, and a heat insulating material 10 is arranged inside. The lid body 2 is rotatably attached to one side of the shoulder member 6 via a hinge mechanism 11, and its open end side is engaged with a predetermined position of the lid body 2. A lock mechanism 12 for maintaining the closed state of the lid body 2 is provided. Reference numeral 13 is a steam discharge passage, and 14 is a lid heater.

The inner pot 3 is made of a non-magnetic metal material having a good thermal conductivity (for example, an aluminum alloy), its central portion is curved upward, and its apex (that is, a center sensor 15 described later is brought into contact therewith). The bottom portion 3a has a flat shape, and the curved surface 3b is continuous from the bottom surface 3a to the side surface 3c. The curved portion 3b is assumed to have a radius of curvature with which rice chamomile can easily come into contact, for example. The bottom surface 3a whose central portion is curved upward,
It serves to strengthen the convection generated in the inner pot 3 when cooking rice.

On the other hand, the protective frame 5 also has a bottom surface 5a whose central portion is curved upward along the bottom surface 3a of the inner pot 3.
And a curved surface 5b and a side surface 5c along the inner pan curved surface 3b and the inner pan side surface 3c, the bottom surface 5 of the protective frame 5
A through hole 16 is formed in the center of a so as to face the center sensor 15 that contacts the bottom surface of the inner pot 3.

The center sensor 15 functions as a temperature detecting means for detecting the temperature of the inner pot 3, and whether or not the thermistor and the inner pot 3 which are temperature detecting parts are set inside the center sensor 15. It has a built-in sensor for detecting inner pot (not shown).

The protective frame bottom surface 5a and the protective frame curved surface 5
In b, annular electromagnetic induction coils 17A and 17B are arranged so as to surround the center sensor 15 and correspond to the inner pot bottom surface 3a and the inner pot curved surface 3b.
The electromagnetic induction coils 17A and 17B act as a magnetism generating means in the high frequency electromagnetic induction heating device.
In these electromagnetic induction coils 17A and 17B, the electromagnetic induction coil 17A on the bottom side is at the same height as or at a position higher than the lowermost part of the electromagnetic induction coil 17B on the side surface side, and the uppermost part of the electromagnetic induction coil 17A on the bottom side is The convection generated in the inner pan 3 by the electromagnetic induction coil 17A on the bottom side and the inner pan by the electromagnetic induction coil 17B on the side surface are arranged so as to be higher than the lowermost portion of the electromagnetic induction coil 17B on the side surface. The balance with the convection that occurs in 3 becomes better,
It is preferable in that good rice can be obtained. Reference numeral 18 is a coil die that holds the electromagnetic induction coils 17A and 17B in a predetermined position, 19 is a ferrite core that shields the electromagnetic induction coils 17A and 17B so as to prevent the magnetism from affecting the equipment below, and 20 is It is a heat retention heater.

In FIG. 1, reference numeral 21 is a control circuit board for controlling energization of the electromagnetic induction coils 17A and 17B, the lid heater 14 and the heat retaining heater 20, 22 is an operation panel, and 23 is an electromagnetic induction coil 17A, 17B. A cooling fan for cooling a power transistor (not shown) for starting and the like, and 24 are air inlets formed on the bottom surface of the outer case 4.

Next, the structure of the inner pot 3 used in the electromagnetic rice cooker according to the present embodiment will be specifically described in detail with reference to FIGS. 2 to 4.

The inner pot 3 is in contact with the grounding surface 3d and the center sensor 15 on the outer surface of the bottom surface 3a (that is, the outer bottom surface) and the outer surface of the curved surface 3b (that is, from the outer bottom surface to the outer surface). A magnetic metal material (for example, iron-based material or iron-based material) that has a high electric resistance to an eddy current generated by high frequency electromagnetic induction in a portion (in other words, a portion corresponding to the electromagnetic induction coils 17A and 17B) excluding the central outer surface of the bottom surface 3a. Thermal sprayed layers 25A and 25B made of stainless steel material are formed. That is, each electromagnetic induction coil 17A, 1
7B is to be arranged along the sprayed layers 25A and 25B.

As a method of not forming the sprayed layer on the grounding surface 3d, a method of scraping off the sprayed layer once formed or a method of masking at the time of spraying is adopted. As a result, the grounding surface 3d is smooth without a sprayed layer. To be a face. Further, the sprayed layers 25A and 25B are the electromagnetic induction coils 17
The area is equal to or larger than the areas of A and 17B.

A fluororesin coating layer 26 (see FIG. 4) is formed on the entire inner peripheral surface of the inner pot 3 for the purpose of preventing adhesion of rice.

The sprayed layers 25A and 25B are formed by spraying a magnetic metal material in a molten state (for example, an iron-based material or a stainless-based material) using a known spraying technique. It has excellent adhesion to the base material and can be formed thin. Therefore, it contributes greatly to the weight reduction and cost reduction of the inner pot 3, and it is excellent in durability without the need to worry about peeling.

Since the sprayed layers 25A and 25B are for spraying a magnetic metal material, the surface becomes rough or the thickness becomes uneven depending on the size of the sprayed particles. When this sprayed layer is formed on the entire outer peripheral surface of the inner pot 3, the ground contact surface 3d becomes rough, and even when the inner pot 3 is placed, the mating member T (for example, sink) may be damaged. , As in the present embodiment, the ground surface 3d of the inner pot 3
If the thermal sprayed layer is not formed on the other side, the mating member T (e.g., sink) is not damaged.

Further, even when the inner pot 3 is housed in the rice cooker main body 1, the electromagnetic spray coils 17A, 17B are formed because the sprayed layer, which is difficult to keep the thickness constant, is not formed on the ground surface 3d. And the distance d between the sprayed layers 25A and 25B
(See FIG. 2) can be secured as designed. Therefore, uniform heating can be performed during rice cooking.

Further, the electromagnetic induction coils 17A, 17
Since B is arranged along the sprayed layers 25A and 25B at the portions corresponding to the sprayed layers 25A and 25B, the electromagnetic induction coils 17A and 17B and the sprayed layer 2 are formed.
Since the distance d between 5A and 25B can be made substantially equal, uniform heating can be performed during rice cooking. Moreover, since the thermal sprayed layers 25A and 25B are formed only in the portions where the high frequency electromagnetic induction heating is required, the inner pan 3 can be reduced in weight and cost.

Furthermore, since the sprayed layer is not formed on the grounding surface 3d of the inner pot 3, the contact portion with the protective frame 5 does not generate heat. Therefore, the thermal deterioration of the protective frame 5 can be suppressed.

Second Embodiment FIG. 5 shows an inner pot of an electromagnetic rice cooker according to a second embodiment of the present invention.

In this case, a sprayed layer 25 made of a magnetic metal material having a high electric resistance against an eddy current generated by high frequency electromagnetic induction is formed on the entire outer peripheral surface of the inner pot 3, and the sprayed layer 25 is formed. The grounded surface 3d portion is the sprayed layer 2
A smooth surface 27 is formed by polishing # 5. In addition, the part where the center sensor 15 is in contact also has a smooth surface 28.
It is said that. According to this structure, even when the inner pot 3 is placed, the mating member (for example, a sink or the like) and the smooth surface 27 come into contact with each other, so that the mating member is not damaged. Moreover, the inner pot 3 is the rice cooker body 1
Since the smooth surface 27 can have a constant thickness even when housed inside, the electromagnetic induction coils 17A, 1
The space between 7B and the sprayed layer 25 can be secured as designed. Further, since the thermal spray layer 25 is formed on the entire outer peripheral surface of the inner pot 3, the thermal spray layer 25 can be easily formed. Further, the detection sensitivity of the center sensor 8 can be sufficiently secured. It is preferable that the smooth surface 28 is thinned by polishing so that the detection sensitivity is good. Other configurations and effects are the same as those in the first embodiment, and the description thereof will be omitted.

[0032]

According to the invention of claim 1, in the electromagnetic rice cooker for heating the inner pot by the high frequency electromagnetic induction by the electromagnetic induction coil, the inner pot is made of a non-magnetic material, and the central portion is directed upward. Curved bottom and from the bottom to the side
Together form a shape having a curved surface continuous Te, the outer surface of the outer surface and the curved surface of the bottom in the <br/> inner bowl
Except for the grounding surface and the outer surface of the center of the bottom surface
Minute, while each <br/> forming a sprayed layer made of a magnetic metal material exhibiting a high electrical resistance to eddy current generated by high frequency electromagnetic induction, out of the outer bottom and outer bottom of the inner bowl
Along the curved surface facing the side surface and along the sprayed layer
The bottom side and side electromagnetic induction coils
Since they are arranged , the high-frequency electromagnetic induction heating performance and the heat transfer performance can be improved, and even when the inner pot is placed, there is an effect that the mating member is not damaged. Moreover, even when the inner pot is stored in the rice cooker main body, the sprayed layer, which is difficult to keep the thickness constant, is not formed on the ground plane, so the spacing between the electromagnetic induction coil and the sprayed layer is as designed. Since it can be ensured, there is also an effect that uniform heating can be performed . Further, since the sprayed layer is not formed on the ground surface 3d of the inner pot 3, even in the type in which the inner pot 3 is stored in the rice cooker in a mounted state, the portion where the bottom surface of the inner pot 3 contacts (For example, the protective frame) does not generate heat, and the thermal deterioration of the protective frame can be suppressed. Also, place the uppermost part of the electromagnetic induction coil on the bottom side on the side
Position it above the bottom of the electromagnetic induction coil
Since it has to, the inner bowl by electromagnetic induction coils on the bottom side
In the inner pan due to the convection that occurs in the
A good balance with the convection that occurs in the
It also has the effect of

According to the invention of claim 2, in the electromagnetic cooker for heating the inner pot by a high-frequency electromagnetic induction by the electromagnetic induction coil, the inner bowl, and of a non-magnetic material, the central portion is curved upwardly From the bottom to the sides
Together form a shape having a curved surface contiguous to the outer bottom surface and an outer surface of the inner pot, and forming a sprayed layer made of a magnetic metal material having a high electrical resistance to eddy current generated by high frequency electromagnetic induction the While forming the ground plane part of the inner pot and the central part of the bottom face in the sprayed layer on a smooth surface ,
The outer bottom surface of the inner pot and the bay extending from the outer bottom surface to the outer surface
The bottom surface side is made to correspond to the curved surface and along the sprayed layer.
Since the electromagnetic induction coils on the side and the side are arranged respectively, it is possible to improve the high-frequency electromagnetic induction heating performance and the heat transfer performance, and to damage the mating member even when the inner pot is placed. There is an effect of disappearing. Moreover, even when the inner pot is housed in the rice cooker body, the smooth surface can have a constant thickness, so that the distance between the electromagnetic induction coil and the sprayed layer can be secured as designed, and a uniform thickness can be obtained. There is also the effect that it can be heated . Also, the top of the electromagnetic induction coil on the bottom side
Is located above the bottom of the electromagnetic induction coil on the side.
The electromagnetic induction coil on the bottom side
More convection in the inner pot and electromagnetic induction coil on the side
The balance with the convection that occurs in the inner pot is better and better.
There is also an effect that you can cook various rice.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an electromagnetic rice cooker according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of an inner pot of the electromagnetic rice cooker according to the first embodiment of the present invention.

FIG. 3 is a bottom view of the inner pot of the electromagnetic rice cooker according to the first embodiment of the present invention.

FIG. 4 is a partially enlarged cross-sectional view of an inner pot of the electromagnetic rice cooker according to the first embodiment of the present invention.

FIG. 5 is a partial vertical cross-sectional view of the inner pot of the electromagnetic rice cooker according to the second embodiment of the present invention.

[Explanation of symbols]

1 is a rice cooker main body, 3 is an inner pot, 3a is a bottom surface, 3b is a curved surface, 3c is a side surface, 3d is a ground surface, 15 is a center sensor, 17A and 17B are electromagnetic induction coils, 25, 25A,
25B is a sprayed layer, 27 is a smooth surface, and T is a mating member (such as a sink).

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) A47J 27/00 103

Claims (2)

(57) [Claims] 1. A solenoid rice cooker to heat the inner bowl by high-frequency electromagnetic induction by the electromagnetic induction coil, the inner bowl, and of a non-magnetic material, the central portion is curved upwardly
A curved bottom surface and a curved surface continuous from the bottom surface to the side surface.
Together form a shape of the bottom surface of the inner bowl
A ground plane portion on the outer surface and the outer surface of the curved surface;
The portion excluding the central portion exterior surface of the bottom surface, while forming a sprayed layer made of a magnetic metal material exhibiting a high electrical resistance to eddy currents caused by the high frequency electromagnetic induction, respectively, said
On the outer bottom surface of the pan and the curved surface from the outer bottom surface to the outer surface
The bottom side and the side corresponding to each other and along the sprayed layer
The electromagnetic induction coils on the surface side are respectively arranged and on the bottom surface side.
Place the uppermost part of the electromagnetic induction coil on the side of the electromagnetic induction coil.
An electromagnetic rice cooker characterized by being located above the bottom of the le . 2. A solenoid rice cooker to heat the inner bowl by high-frequency electromagnetic induction by the electromagnetic induction coil, the inner bowl, and of a non-magnetic material, the central portion is curved upwardly
A curved bottom surface and a curved surface continuous from the bottom surface to the side surface.
Together form a shape, the outer bottom surface and an outer surface of the inner pot forms a sprayed layer made of a magnetic metal material exhibiting a high electrical resistance to eddy current generated by high frequency electromagnetic induction and inner bowl in solution picolinimidate Ground plane part and the bottom surface
The outer surface of the inner pot is formed while the outer surface of the center part of the
Surface and the curved surface from the outer bottom surface to the outer surface
In addition, the bottom surface side surface and the side surface side surface are electrically connected along the sprayed layer.
Magnetic induction coils are respectively arranged and electromagnetic induction on the bottom side
Place the top of the coil at the bottom of the electromagnetic induction coil on the side.
An electromagnetic rice cooker characterized by being placed above the section .