JP7269482B2 - induction heater - Google Patents

Description

The present invention relates to induction heaters.

A rice cooker main body having an open upper surface in the past, an inner pot detachably stored in the rice cooker main body, a protective frame for housing the inner pot in the rice cooker main body, and a bottom portion of the protective frame. A first heating coil along the bottom surface of the inner pot, a second heating coil along the lower side surface of the inner pot, and high-frequency power are supplied to the first and second heating coils to induce the inner pot. an inverter for heating; a control means for controlling the inverter to control induction heating during rice cooking, heat retention, etc.; a non-magnetic metal plate, the non-magnetic metal plate being installed on the bottom portion of the rice cooker main body so as to face the first and second heating coils, and the end face being connected to the second heating coil. A rice cooker has been proposed that has a bent portion along the entire circumference and is formed in a ring shape (see, for example, Japanese Patent Application Laid-Open No. 2010-240051).

JP 2010-240051 A

By the way, normally, an induction heater such as an induction heating rice cooker has a magnetic shielding member (for example, non-magnetic metal plate) is installed. Such a magnetic shielding member generally has a cylindrical shape with a bottom so as to cover the entire induction heating coil from below, and is installed above the bottom wall portion of the main body of the induction heater. However, in such a case, even if an exhaust port is formed in the bottom wall portion of the main body of the induction heater, there arises a problem that exhaust (exhaust heat) cannot be performed efficiently.

SUMMARY OF THE INVENTION An object of the present invention is to provide an induction heater capable of efficiently exhausting (exhausting heat) while sufficiently shielding against a magnetic field generated from an induction heating coil.

The induction heater according to the present invention is
a body to be heated;
a first induction heating coil arranged to face the object to be heated;
a second induction heating coil disposed outside the first induction heating coil so as to face the body to be heated and be spaced apart from the first induction heating coil;
a first magnetic shield disposed on the opposite side of the first induction heating coil from the side of the object to be heated;
a second magnetic shield disposed on the opposite side of the second induction heating coil from the side of the object to be heated;
a bottom wall portion provided with an exhaust port disposed below the object to be heated;
with
a third magnetic shield part at least partially disposed between the outer circumference of the first induction heating coil and the outer circumference of the second induction heating coil when viewed through a plane ;
and a fourth magnetic shield disposed below the first magnetic shield ,
At least a part of the exhaust port is formed between the third magnetic shielding portion and the fourth magnetic shielding portion when viewed through the plane .

According to the above configuration, the first magnetic shielding portion is arranged on the opposite side of the first induction heating coil from the object to be heated, and the second magnetic shielding portion is arranged on the opposite side of the second induction heating coil from the object to be heated, At least a portion of the third magnetic shielding portion is disposed between the outer circumference of the first induction heating coil and the outer circumference of the second induction heating coil when viewed through the plane. In this induction heater, the first magnetic shield suppresses the leakage of the magnetic field generated by the first induction heating coil to the outside, and the second magnetic shield suppresses the leakage of the magnetic field generated by the second induction heating coil to the outside. The magnetic shield suppresses it, and further, the third magnetic shield suppresses leakage of the magnetic field leaking from between the first magnetic shield and the second magnetic shield to the outside. Therefore, in this induction heater, the magnetic field generated by the induction heating coil can be sufficiently shielded, and an exhaust space is secured between the first, second, and third magnetic shields. can do. Therefore, in this induction heater, exhaust can be efficiently performed while sufficiently shielding against the magnetic field generated from the induction heating coil.

In addition, in this induction heater, by providing the third magnetic shield, the distance between the first magnetic shield and the second magnetic shield can be set relatively freely. The distance from the second induction heating coil can be set relatively freely. Therefore, in this induction heater, the heating efficiency can be adjusted.

Further, according to the above configuration, the exhaust space between the third magnetic shield portion and the fourth magnetic shield portion can be communicated with the exhaust port in a short distance, and the airflow between the third magnetic shield portion and the fourth magnetic shield portion can be communicated. The incoming exhaust can be efficiently guided to the exhaust port.

In the present invention,
It is preferable that the third magnetic shield part has an annular shape.

As a result of diligent studies by the inventors of the present application, it has been found that the magnetic shielding effect is improved when the third magnetic shielding member is ring-shaped as compared to when it is not ring-shaped. Therefore, in this induction heater, it is possible to further suppress leakage of the magnetic field generated from the induction coil to the outside.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view of the rice cooker which concerns on embodiment of this invention. It is a top view of a rice cooker concerning an embodiment of the invention. FIG. 3 is a sectional view taken along line II of FIGS. 1 and 2; FIG. 3 is a partial cross-sectional view taken along the line II-II of FIG. 2 (the main body of the rice cooker according to the embodiment of the present invention is cut along the ferrite core arrangement direction, and some members such as shoulder members are not depicted). omitted). FIG. 3 is a partial cross-sectional view taken along line III-III of FIG. 2 (illustration of some members such as shoulder members is omitted); It is a bottom view of the state which removed the bottom wall from the rice cooker which concerns on embodiment of this invention. Fig. 2 is a plan view showing the bottom wall, the horizontal shielding plate and the bottom shielding plate that constitute the rice cooker according to the embodiment of the present invention; It is a magnetic field strength measurement result in the vertical direction of the rice cooker according to the embodiment of the present invention when no horizontal shielding plate is provided. It is a magnetic field intensity measurement result of the vertical direction of the rice cooker according to the embodiment of the present invention when the horizontal shielding plate is arranged.

<Structure of the rice cooker according to the embodiment of the present invention>
A rice cooker 100 according to an embodiment of the present invention is an induction heating pressure rice cooker, and as shown in FIGS. It consists of a mechanism 150 . These constituent elements are described in detail below.

1. Main Body Main body 110, as shown in FIGS. 115 , a heat sink 116 , an operation panel 117 , a power circuit board 118 , a control circuit board 119 and an automatic winding type power cord unit 120 . These constituent elements are described in detail below.

(1) Housing As shown in FIGS. 1, 3 and 6, the housing 111 is mainly composed of a side wall 111a, a bottom wall 111b, a shoulder member 111c and a protective frame 111d. not shown), induction heating coil 113, ferrite core assembly 121, horizontal shielding plate SP1, bottom shielding plate SP2, thermistor 114, blower fan 115, heat sink 116, power supply circuit board 118, control circuit board 119 and automatic winding type It accommodates the power cord unit 120 and the like. An operation panel 117 is arranged on the upper front side of the shoulder member 111c. Each component of the housing 111 will be described in detail below.

The side wall 111a is an enclosure wall having a substantially rectangular shape in plan view as shown in FIG. 6, and covers the side surface of the main body 110 as shown in FIGS.

The bottom wall 111b is a substantially rectangular plate-like body and is fitted under the side wall 111a as shown in FIGS. 1 and 3 to 5 to cover the opening on the bottom side of the side wall 111a. As shown in FIG. 7, the bottom wall 111b is mainly formed with a cover member accommodating portion 127a, an intake port Os and an exhaust port Oe. The cover member accommodating portion 127a is a portion for accommodating a cover member 127 (described later) that supports the thermistor 114 (described later), and is formed in the central portion of the bottom wall 111b as shown in FIG. . The intake port Os is a part for sucking in the air outside the housing 111, and is formed in the front part of the bottom wall 111b as shown in FIGS. The exhaust port Oe is a portion for discharging the air inside the housing 111 to the outside, and is formed in the rear portion and the left and right side portions of the bottom wall 111b as shown in FIG. Here, as shown in FIG. 7, a part of the exhaust port Oe formed in the rear part of the bottom wall 111b is located between the lateral shielding plate SP1 (described later) and the bottom shielding plate SP2 (described later) when viewed through the plane. formed. In addition, the exhaust ports Oe formed on both left and right sides of the bottom wall 111b are formed between a horizontal shielding plate SP1 (described later) and a bottom shielding plate SP2 (described later) when viewed through the plane. In addition, as shown in FIG. 3, a blower fan 115 is arranged directly above the air inlet Os. When the blower fan 115 is driven, outside air is sucked into the housing 111 through the air intake port Os, and the air flow generated thereby causes the heated air inside to be discharged from the system through the exhaust port Oe. . A bottom shielding plate SP2 (described later) is provided at the center of the top surface of the bottom wall 111b.

Further, as shown in FIG. 4, an upper protrusion ST1 is provided on the inside (upper side) of the bottom wall 111b to prevent the second ferrite core FC2 from completely falling off from the ferrite core assembly 121. It is

The shoulder member 111c is a substantially rectangular frame, and as shown in FIGS. 1 and 3, is fitted on the upper side of the side wall 111a to cover the edge of the upper opening of the side wall 111a. As shown in FIG. 3, a protective frame 111d is attached to the lower side of the shoulder member 111c. In addition, as shown in FIG. 3, the protection frame 111d is attached to the shoulder member 111c with a protection frame flange portion FP (described later).

The protective frame 111d is a member that protects the outer circumference of the inner pot 130 and keeps the shape of the shoulder member 111c.As shown in FIG. It is formed from FP. The inner pot housing portion PA is a bowl-shaped portion that covers the outer circumference of the inner pot 130 . As described above, the protective frame flange portion FP is arranged below the shoulder member 111c and maintains the shape of the shoulder member 111c by stretching the shoulder member 111c outward.

(2) Handle The handle 112 is a member provided for the user to carry the rice cooker 100 by hand, and is composed of a body portion 112a and a shaft portion 112b as shown in FIG. The body portion 112a has a U-shape as shown in FIG. The shaft portion 112b extends inward from both ends of the body portion 112a as shown in FIG. In this rice cooker 100, the shaft portion 112b passes through a hole (not shown) formed in the upper portion of the longitudinal center of the side wall 111a and passes through a fitting portion (not shown) formed in the protective frame 111d. ).

(3) Heat Insulating Material The heat insulating material is wrapped around the side wall of the inner pot housing portion PA of the protective frame 111d and the outer periphery of the induction heating coil 113, and the heat generated from the inner pot 130 during rice cooking is transferred to the outside of the inner pot housing portion PA. It plays a role in suppressing the outflow of

(4) Induction Heating Coil The induction heating coil 113 is an induction heating source that generates a magnetic field to induction-heat the inner pot 130. As shown in FIGS. and a second induction heating coil 113b. As shown in FIGS. 4 and 5, the first induction heating coil 113a is arranged below the bottom wall portion of the inner pot accommodating portion PA of the protective frame 111d. As shown in FIGS. 4 and 5, the second induction heating coil 113b is placed outside the lower end of the side wall of the inner pot housing portion PA of the protective frame 111d so as to be spaced apart from the first induction heating coil 113a. It is arranged along the curved surface of the portion PA.

(5) Ferrite Core Assemblies Four ferrite core assemblies 121 are arranged around the induction heating coil 113 as shown in FIG. This ferrite core assembly 121 comprises a first ferrite core FC1, a second ferrite core FC2 and a ferrite core holder 122 as shown in FIG. The first ferrite core FC1 and the second ferrite core FC2 are rectangular parallelepiped ferrite cores having the same dimensions. The first ferrite core FC1 plays a role of suppressing leakage of the magnetic field generated from the first induction heating coil 113a when energized, and as shown in FIG. is arranged to The second ferrite core FC2 plays a role of suppressing leakage of the magnetic field generated from the second induction heating coil 113b when energized, and as shown in FIG. is arranged to The first ferrite core FC1 and the second ferrite core FC2 are accommodated and fixed in a ferrite core holder 122 as shown in FIG. In addition, between the first ferrite core FC1 and the second ferrite core FC2, an insulating adhesive (for example, a room-temperature curing mold silicone rubber, etc.) is injected.

The ferrite core holder 122 is formed with a first induction heating coil support (not shown) and a second induction heating coil support (not shown). The first induction heating coil support portion is a projecting portion that plays a role of supporting the first induction heating coil 113a. The second induction heating coil support portion is a concave curved portion that plays a role of supporting the second induction heating coil 113b.

(6) Horizontal Shielding Plate The horizontal shielding plate SP1 is an annular member made of metal (for example, aluminum), and the magnetic field leaking from between the first ferrite core FC1 and the second ferrite core FC2 leaks to the outside. It plays a role in suppressing the Here, as shown in FIG. 6, the central portion of the front side of the horizontal shielding plate SP1 is arranged so as to be positioned between the inner circumference and the outer circumference of the first induction heating coil 113a in bottom view. . As shown in FIG. 6, the horizontal shielding plate SP1 is located between the outer periphery of the first induction heating coil 113a and the outer periphery of the second induction heating coil 113b in bottom view. are placed in Furthermore, as shown in FIGS. 4 and 5, the horizontal shielding plate SP1 is positioned below the second induction heating coil 113b in a side view. The horizontal shielding plate SP1 is sandwiched between the bottom wall 111b and the ferrite core holder 122, as shown in FIGS.

Here, in order to confirm the magnetic shielding performance of the horizontal shielding plate SP1, the magnetic field strength in the vertical direction with respect to the rice cooker 100 was measured using a three-axis loop antenna with a diameter of 2 meters. FIG. 8 shows the measurement results when the horizontal shielding plate SP1 is not provided, and FIG. 9 shows the measurement results when the horizontal shielding plate SP1 is provided. In FIGS. 8 and 9, the horizontal axis is frequency (MHz), the vertical axis is magnetic field strength (dB (μA)), and QP is the limit value of magnetic field strength in the vertical direction specified by the Radio Law. . Without the horizontal shield SP1, as shown in FIG. 8, only a margin of +2.1 dB could be ensured with respect to the vertical magnetic field strength limit specified by the Radio Law. However, when the horizontal shielding plate SP1 was arranged, as shown in FIG. 9, it was possible to secure a margin of +6.3 dB with respect to the limit value of the magnetic field strength in the vertical direction stipulated by the Radio Law. .

(7) Bottom Shielding Plate The bottom shielding plate SP2 plays a role of suppressing leakage of the magnetic field generated from the first induction heating coil 113a to the outside and shielding heat. As shown in FIGS. 4 to 7, the bottom shielding plate SP2 is a plate-like member having a substantially rectangular shape with a circular opening in the center, and is made of metal (for example, aluminum). As described above, the bottom shielding plate SP2 is arranged at the center of the top surface of the bottom wall 111b. Further, the bottom shielding plate SP2 is arranged so as not to block the exhaust port Oe.

(8) Thermistor The thermistor 114 is a temperature sensor, and as shown in FIGS. protruding towards. The thermistor 114 is biased upward by a biasing member such as a coil spring. In other words, the thermistor 114 is arranged to be movable in the vertical direction. Also, this thermistor 114 is incorporated in an inner pot detection sensor (not shown). The inner pot detection sensor is for determining whether or not the inner pot 130 is present in the rice cooker 100. When the thermistor 114 is lowered to the lower end position, a detection signal is sent to the microcomputer on the control circuit board 119. Send. Upon receiving the detection signal, the microcomputer determines that the inner pot 130 is present in the rice cooker. Note that when the microcomputer determines that the inner pot 130 does not exist in the rice cooker, the rice cooking operation is not started. By the way, the thermistor 114 is supported by a substantially disk-shaped cover member 127 as shown in FIGS. The cover member 127 is screwed to the bottom wall of the inner pot accommodating portion PA of the protective frame 111d. Then, as shown in FIGS. 6 and 7, the cover member 127 is housed in the cover member housing portion 127a through the opening of the bottom shielding plate SP2.

(9) Blower Fan As described above, the blower fan 115 is disposed directly above the intake port Os formed in the bottom wall 111b of the housing 111 so that the rotation axis extends substantially in the vertical direction (Fig. 3). That is, when the blower fan 115 is driven, outside air is sucked from the intake port Os, flows into the housing, and is sent upward as it is. The external air sent upward passes through the heat sink 116 and is supplied to the power circuit board 118, the control circuit board 119, and the like to cool these members.

(10) Heat Sink The heat sink 116 is a component that efficiently exchanges heat with the outside air.

(11) Operation Panel The operation panel 117 is for determining and executing the operation method of the rice cooker 100, and as shown in FIGS. As described above, it is arranged on the upper front side of the shoulder member 111c.

(12) Power Supply Circuit Board The power supply circuit board 118 is a board that constitutes a power supply circuit, and several heat-generating components are mounted thereon. 3, the power circuit board 118 is housed in the front space SPf of the housing 111, like the control circuit board 119, which will be described later.

(13) Control Circuit Board The control circuit board 119 is a board constituting a control circuit, and has electronic components such as a microcomputer mounted thereon. The control circuit board 119 is accommodated in the front space SPf of the housing 111 as shown in FIG.

(14) Automatic Winding Power Cord Unit The automatic winding power cord unit 120 is composed of a power cord, an automatic winding mechanism (not shown), etc., and is housed as shown in FIGS. It is accommodated in the space behind the body 111 . The power cord consists of an insertion plug OP and an electric wire (not shown). The insertion plug OP is arranged at the tip of the electric wire. The electric wire is extendably wound around an automatic winding mechanism.

2. Inner Pot The inner pot 130 is a bowl-shaped pot that opens upward, is inserted through the opening of the shoulder member 111c, and is accommodated in the inner pot accommodating portion PA of the protective frame 111d with a predetermined gap. Here, the inner pot 130 is a multi-layer body (clad material) of various aluminum alloys and stainless alloys, and can be induction-heated by the induction heating coil 113 .

3. Lid Body Lid body 140, as shown in FIGS. It is It is rotatably attached to the main body 110 via a hinge mechanism 150 .

As shown in FIGS. 1 to 3, the exterior body 141 is a substantially rectangular parallelepiped member and accommodates an open/close button 142, a pressure adjustment mechanism 143, a lever member 146, and the like. Here, as shown in FIGS. 1 and 2, the open/close button 142 is arranged on the exterior body 141 so that its upper surface is exposed above the exterior body 141 . Also, here, the exterior body 141 is reinforced with a reinforcing member so as to withstand the internal pressure during use. Further, an inner lid 145 is detachably arranged on the lower surface of the exterior body 141 .

The open/close button 142 is a rectangular button with rounded corners for opening and closing the cover 140 and is arranged above the lever member 146 . The open/close button 142 is biased upward by a coil spring (not shown).

The lever member 146 includes an abutment plate portion (not shown), a pair of left and right extended plate portions (not shown) extending downward from the front side of the abutment plate portion, and rearward from the lower portion of each extended plate portion. It is a metal plate member formed of a claw portion (not shown) extending toward and is pivotally supported by the exterior body 141, and is pushed upward by a coil spring (not shown) at the rear end of the contact plate portion. urged toward. Here, when the open/close button 142 is pushed down by the user, the open/close button 142 comes into contact with a portion of the contact plate portion of the lever member 146 on the rear side of the rotation shaft.

When the user wants to close the lid 140 , the user does not need to operate the open/close button 142 , and can simply push the lid 140 toward the main body 110 . At this time, the claw portion of the lever member 146 moves downward while contacting an inclined surface (not shown) formed on the shoulder member 111c. During this time, the lever member 146 rotates forward against the biasing force of the coil spring. When the pawl reaches a pawl receiving hole (not shown) formed in the shoulder member 111c, the pawl is fitted into the pawl receiving hole by the biasing force of the coil spring. In this manner, the lid 140 is closed. On the other hand, when the lid body 140 is to be opened, the user presses the open/close button 142 . Then, the lower end portion of the open/close button 142 contacts the contact portion of the lever member 146, and the lever member 146 rotates forward against the biasing force of the coil spring. At this time, the claw portion fitted in the claw receiving hole is pulled out from the claw receiving hole. Then, the lid 140 is lifted upward by the biasing force of the hinge mechanism 150, and the lid 140 is opened.

The pressure adjustment mechanism 143 adjusts the pressure inside the inner pot 130 to 1.03 to 1.3 atm when the lid 140 is closed and the rice is cooked under pressure. Further, the pressure adjusting mechanism 143 regulates the rotation of the lever member 146 so as not to open the lid 140 during the pressure rice cooking operation. In this embodiment, the pressure adjusting mechanism is not particularly limited, and a conventional one may be employed.

The reinforcing member is for enhancing the strength of the lid body 140 . In the present embodiment, the reinforcing member is not particularly limited, and may be a metal plate itself or a metal plate having a complicated shape.

The inner lid 145 is a member for covering and sealing the upper portion of the inner pot 130 as shown in FIG.

4. Hinge Mechanism As described above, the hinge mechanism 150 attaches the lid 140 to the main body 110 so that the lid 140 is rotatable relative to the main body 110 . As described above, the hinge mechanism 150 biases the lid 140 in the opening direction.

<Characteristics of the rice cooker according to the embodiment of the present invention>
(1)
In the rice cooker 100 according to the embodiment of the present invention, the first induction heating coil 113a is arranged below the bottom wall portion of the inner pot accommodating portion PA of the protective frame 111d, and the second induction heating coil 113b is arranged on the first It is disposed outside the lower end of the side wall of the inner pot accommodating portion PA of the protective frame 111d so as to be spaced apart from the induction heating coil 113a. A first ferrite core FC1, which suppresses leakage of the magnetic field generated from the first induction heating coil 113a when energized, is arranged to face the first induction heating coil 113a. A second ferrite core FC2 that suppresses leakage of the magnetic field generated from the second induction heating coil 113b when energized is arranged to face the second induction heating coil 113b. Furthermore, at least part of the horizontal shielding plate SP1 that suppresses leakage of the magnetic field leaking from between the first ferrite core FC1 and the second ferrite core FC2 to the outside is separated from the outer periphery of the first induction heating coil 113a and the second induction heating coil 113a. It is arranged so as to be positioned between the outer circumference of the coil 113b. Therefore, in this rice cooker 100, the magnetic field generated by the first induction heating coil 113a and the second induction heating coil 113b can be sufficiently shielded, and the first ferrite core FC1 and the second ferrite core FC2 can be sufficiently shielded. and the lateral shielding plate SP1, an exhaust space can be secured. Therefore, in this rice cooker 100, exhaust can be efficiently performed while sufficiently shielding the magnetic field generated from the induction heating coils 113a and 113b.

(2)
In rice cooker 100 according to the embodiment of the present invention, a metal annular member is adopted as horizontal shielding plate SP1. When the vertical magnetic field strength of the rice cooker 100 was measured using a three-axis loop antenna with a diameter of 2 meters, it was +6.3 dB above the vertical magnetic field strength limit value stipulated by the Radio Law. It became clear that a margin could be secured. Therefore, in this rice cooker 100, the magnetic field generated by the induction heating coil 113 can be sufficiently shielded.

(3)
In the rice cooker 100 according to the embodiment of the present invention, the exhaust port Oe is formed in the rear portion and the left and right sides of the bottom wall 111b of the housing 111. The opening Oe is not blocked by the first ferrite core FC1, the second ferrite core FC2, the side shielding plate SP1 and the bottom shielding plate SP2. Further, the exhaust port Oe formed in the rear portion of the bottom wall 111b is not blocked by the first ferrite core FC1, the second ferrite core FC2 and the bottom shielding plate SP2, but is slightly blocked by the horizontal shielding plate SP1. It's just that Therefore, the exhaust space between the lateral shielding plate SP1 and the bottom shielding plate SP2 can be communicated with the exhaust port Oe in a short distance, and the exhaust gas flowing between the lateral shielding plate SP1 and the bottom shielding plate SP2 can be prevented. It can be efficiently guided to the exhaust port Oe.

<Modification>
(A)
In the rice cooker 100 according to the previous embodiment, as a member for suppressing leakage of the magnetic field leaking from between the first ferrite core FC1 and the second ferrite core FC2 to the outside, an annular ring made of metal (for example, aluminum) is provided. Although the lateral shielding plate SP1, which is a member, has been employed, metal lead wires, for example, may be employed instead of the lateral shielding plate SP1.

(B)
In rice cooker 100 according to the previous embodiment, the central portion of the front side of horizontal shielding plate SP1 is arranged so as to be positioned between the inner circumference and the outer circumference of first induction heating coil 113a in bottom view. rice field. However, the front central portion of the horizontal shielding plate SP1 may be designed so as to be positioned between the outer circumference of the first induction heating coil 113a and the outer circumference of the second induction heating coil 113b in bottom view. In this case, the entire horizontal shielding plate SP1 is arranged so as to be positioned between the outer circumference of the first induction heating coil 113a and the outer circumference of the second induction heating coil 113b in bottom view.

(C)
In the rice cooker 100 according to the previous embodiment, the bottom shielding plate SP2 has a substantially rectangular shape. However, the shape of the bottom shielding plate SP2 is not particularly limited.

(D)
In rice cooker 100 according to the previous embodiment, at least a portion of exhaust port Oe formed in the rear portion of bottom wall 111b of housing 111 is located between lateral shielding plate SP1 and bottom shielding plate SP2 in plan see-through. was formed. In addition, the exhaust ports Oe formed on both left and right sides of the bottom wall 111b are formed between the lateral shielding plate SP1 and the bottom shielding plate SP2 when viewed through the plane. However, the exhaust port Oe may be formed outside the bottom shielding plate SP2 when viewed through the plane.

(E)
In the rice cooker according to the previous embodiment, an annular member was adopted as the horizontal shielding plate SP1, but a partial annular member may be adopted as the horizontal shielding plate SP1.

(F)
In the rice cooker 100 according to the previous embodiment, the second induction heating coil 113b is positioned outside the lower end of the side wall of the inner pot accommodating portion PA of the protective frame 111d so as to be separated from the first induction heating coil 113a. It was arranged along the curved surface of the housing part PA. However, the second induction heating coil 113b may be arranged along the outer peripheral surface of the side wall of the inner pot housing portion PA.

(G)
Although the present invention was applied to the rice cooker 100 in the previous embodiment, the present invention may be applied to other induction heating heaters (induction heating hot plates, electric kettles, electric water heaters, etc.). .

100: Rice cooker (heating cooker)
111b: bottom wall (bottom wall portion)
113: induction heating coil 113a: first induction heating coil 113b: second induction heating coil 130: inner pot (object to be heated)
FC1: First ferrite core (first magnetic shield)
FC2: Second ferrite core (second magnetic shield)
Oe: Exhaust port SP1: Horizontal shield plate (third magnetic shield part)
SP2: bottom shield plate (fourth magnetic shield)

Claims (2)

a body to be heated;
a first induction heating coil arranged to face the object to be heated;
a second induction heating coil disposed outside the first induction heating coil so as to face the body to be heated and be spaced apart from the first induction heating coil;
a first magnetic shield disposed on the opposite side of the first induction heating coil from the side of the object to be heated;
a second magnetic shield disposed on the opposite side of the second induction heating coil from the side of the object to be heated;
a bottom wall portion provided with an exhaust port disposed below the object to be heated;
with
a third magnetic shield part at least partially disposed between the outer circumference of the first induction heating coil and the outer circumference of the second induction heating coil when viewed through a plane ;
and a fourth magnetic shield disposed below the first magnetic shield ,
At least a portion of the exhaust port is formed between the third magnetic shielding portion and the fourth magnetic shielding portion in plan perspective view,
induction heater. 2. The induction heater according to claim 1, wherein said third magnetic shield has an annular shape.

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