Patent Publication Number: US-2021168912-A1

Title: Induction heating cooker

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based on and claims priority under 35 U.S.C. § 119 of a Japanese patent application number 2019-216178, filed on Nov. 29, 2019 in the Japanese Patent Office and of a Korean patent application number 10-2020-0101623, filed on Aug. 13, 2020 in the Korean Intellectual Property Office, the disclosure of each of which is incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Field 
     The disclosure relates to an induction heating cooker. More particularly, the disclosure relates to an induction heating cooker for achieving high output of power and small thickness. 
     2. Description of Related Art 
     An induction heating cooker allows a high-frequency current to pass through a heating coil to generate a high-frequency magnetic flux, which is provided to pass through a heating object, such as a frying pan or a pot, loaded on a top plate, and heat the heating object using electromagnetic induction. In such an induction heating (IH), a high-frequency magnetic flux passing through a heating object induces an eddy current to the heating object, and the heating object is heated by heat generated by the electrical resistance thereof 
     In an induction heating cooker, when induction heating heats a heating object, the heating coil becomes hot due to a phenomenon (referred to as a skin effect or a proximity effect), such as causing energy loss. Accordingly, in order to cool the heating coil, the induction heating cooker is provided with a blower device that introduces external air into a main body and blows the introduced air to the heating coil. An example of the induction heating cooker is disclosed in Japanese Patent Application Publication Number JP2019-046726 A. 
     The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure. 
     SUMMARY 
     In order to improve the heating performance for the heating object, the above described induction heating cooker needs to achieve high output of power. In order to achieve high output of power in the induction heating cooker, current applied to the heating coil needs to have high frequency or high current, which results in heat generation increasing by the induction heating of the heating coil. Therefore, in the conventional induction heating cooker, a large-sized air blower device is used to improve the cooling function of the heating coil. 
     In particular, in the case of an induction heating cooker capable of coping with all types of metals by induction-heating even non-magnetic and low-resistance metals, such as aluminum and copper, since the frequency of current applied to the heating coil is high, a large-sized blower device is required to cool the heating coil. However, when a large-sized blower device is used, a relatively large space is required in the main body to accommodate the blower device, which causes the size of the induction heating cooker to be increased. 
     Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure to provide an induction heating cooker capable of increasing output of power of the induction heating cooker with a reduced size. 
     In order to achieve the above object, in the technique of the disclosure, air is blown from a blower device to the heating coil in two directions. 
     Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments. 
     In accordance with an aspect of the disclosure, an induction heating cooker is provided. The induction heating cooker includes a main body provided at an upper side with a top plate, a heating coil to induction-heat a heating object loaded on the top plate, and a blower device provided in the main body and configured to blow air into the heating coil by introducing external air. The heating coil and the blower device are accommodated in the main body. The induction heating cooker according to the disclosure includes a first flow path for allowing air blown by the blowing device to be supplied toward the heating coil from an outer periphery side and a second flow path allowing air blown by the blowing device to be supplied toward the heating coil from a lower side. 
     With such a configuration, air is blown to the heating coil in two directions from the rear side and the lower side by the first blower and the second blower, so that the heating coil can be cooled efficiently. Therefore, high frequency current, which may cause the heating coil to generate relatively large heat, may be applied to the heating coil, so that high frequency or high current of current applied to the heating coil can be achieved, thereby providing the induction heating cooker with high output of power. In addition, since the heating coil is efficiently cooled, the blower device is reduced, so that the size of the induction heating cooker  1  can be reduced. 
     In the induction heating cooker according to the technology of the disclosure, the main body is provided with an exhaust port for discharging air passed through the heating. In this case, the exhaust port may be preferably positioned in the direction in which the blower device blows air to the first flow path. 
     With such a configuration, air is blown toward the exhaust port by the blower device, so that the air having a temperature elevated in the main body may be smoothly discharged out of the main body through the exhaust port while being suppressed from staying around the heating coil. Such a configuration is beneficial in efficiently cooling the heating coil. 
     In accordance with an aspect of the disclosure, the induction heating cooker to the technology is provided. The induction heating cooker to the technology includes a partition member that divides the space in the main body in the vertical direction. The partition member divides a first space constituting the first flow path and a second space constituting the second flow path. The blower device may blow air into the first space and the second space. In this case, the partition member may be preferably formed with a ventilation hole for allowing air blown by the blower device to flow from the second space, passing through the first space, to be supplied toward the heating coil from the lower side. 
     With such a configuration, since the air blown into the first space by the blower device is supplied to the heating coil from the outer periphery side, and the air blown into the second space is supplied to the heating coil from the lower side through the ventilation hole of the partition member, thereby easily implementing a configuration of blowing air to the heating coil in two directions by the blower device. 
     The partition member may be preferably provided with an edge wall surrounding at least a space in which the heating coil is disposed between the upper plate and the partition member in the first space. 
     With such a configuration, since a space in which the heating coil is disposed in the first space is surrounded by the edge wall of the partition member, air having a temperature elevated due to heat generation of the heating coil in the main body may be suppressed from leaking out to the surroundings, and the temperature elevated air may be efficiently discharged out of the main body through the exhaust port. Such a configuration is beneficial in efficiently dissipating heat of the induction heating cooker by preventing heat from staying in the main body. 
     The plurality of ventilation holes of the partition member are provided to be open toward a plurality of locations at intervals from each other in the circumferential direction of the heating coil. 
     With such a configuration, since the air blown to the second space by the blower device is supplied to a plurality of locations at intervals in the circumferential direction of the heating coil through the plurality of ventilation holes formed in the partition member, the heating coil may be cooled at the plurality of locations in the circumferential direction and thus can be efficiently cooled as a whole. 
     In the induction heating cooker provided with the partition member, the blower device may be disposed at one side in a horizontal direction with respect to the second space. In this case, the second space may be preferably provided with a splitting wall that divides air blown by the blower device into one side and the other side of an area corresponding to the heating coil in the vertical direction. 
     With such a configuration, air blown by the blower device is divided into one side and the other side of an area corresponding to the heating coil in the vertical direction by the splitting wall, so that a large amount of air is prevented from being circulated to a specific ventilation hole, and air is evenly discharged through a plurality of ventilation holes. Such a configuration is beneficial in efficiently cooling the heating coil as a whole. 
     In accordance with an aspect of the disclosure, the induction heating cooker with the partition member is provided. The induction heating cooker with the partition member includes a power supply circuit for supplying power to the heating coil. The first space may be an upper space partitioned by the partition member among the spaces within the main body, and the second space may be a space formed inside the partition member. In this case, the power supply circuit may be disposed in a lower space partitioned by the partition member among the spaces within the main body. 
     With such a configuration, the power supply circuit is separated from the heating coil by the partition member having the second space, so that heat generated by the heating coil is prevented from exerting an adverse effect on the power supply circuit. Accordingly, the reliability of the induction heating cooker may be increased. 
     In the induction heating cooker according to the technology of the disclosure, the amount of air flowing through the second flow path is preferably provided to be larger than the amount of air flowing through the first flow path. 
     With such a configuration, the blower device allows the heating coil to be supplied with air from a lower side thereof in an amount larger than that supplied from an outer periphery side thereof Since the heating coil comes in contact with the air blown from the lower side of the heating coil in a larger area compared to the air blown from the outer periphery side, the efficiency of heat dissipation of the heating coil may be enhanced. Therefore, blowing a relatively large amount of air to the heating coil from the lower side contributes to increasing the cooling efficiency of the heating coil. 
     In the induction heating cooker according to the present disclosure, the blower device may preferably have a plurality of blowers which are disposed at different positions in the horizontal direction. 
     With such a configuration, the plurality of blower forming the blower device, which are disposed at different positions in the horizontal direction, may secure the total volume of air blown to the first flow path and the second flow path by the plurality of blowers while miniaturizing each blower. Such a configuration contributes to reducing the size of the induction heating cooker. 
     In accordance with an aspect of the disclosure, an induction heating cooker is provided. An induction heating cooker incudes a heating coil configured to heat a heating object, a first blower configured to blower air to the heating coil, a first flow path including a center flow path allowing the air from the first blower to be blown toward the heating coil in a first direction, and a second flow path provided to the air from the first blower to be blown toward the heating coil in a second direction  1  different from the first direction, and separated from the first flow path. 
     In accordance with an aspect of the disclosure, the induction heating cooker is provided. The induction heating cooker includes a circuit board disposed on a space separated from a space in which the heating coil is located, and a second blower configured to blow air toward the circuit board. 
     In accordance with an aspect of the disclosure, the first flow path includes a side flow path to allow the air from the second blower to be blown in a third direction different from the first direction and the second direction toward the heating coil. 
     The second blower may be arranged at a side in a horizontal direction with respect to the first blower. 
     The induction heating cooker may further include a substrate edge wall provided to surround the circuit board such that air having heat exchanged with the circuit board is guided to an outside. 
     In accordance with an aspect of the disclosure, the induction heating cooker may further include a third flow path is provided. The induction heating cooker includes to allow the air from the second blower to be guided toward one portion of the circuit board, and a fourth flow path provided to allow the air from the second blower to be guided to another portion of the circuit board, and separated from the third flow path. 
     The third flow path may be provided to guide air toward a side surface of the circuit board, and the fourth flow path may be provided to guide air toward an upper surface of the circuit board. 
     The induction heating cooker may further include a plurality of ventilation holes through which air passing through the second flow path is discharged to the heating coil, and the plurality of ventilation holes may be spaced apart from each other along a circumferential direction of the heating coil. 
     In accordance with an aspect of the disclosure, the second flow path may include a left side flow path is provided to guide the air from the first blower in one direction along the circumferential direction of the heating coil, and a right side flow path provided to guide the air from the first blower in a direction opposite to the one direction along the circumferential direction of the heating coil. 
     The second flow path may be formed to blow air in an amount larger than an amount in which the first flow path blows air. 
     The first flow path may be provided to guide air toward a side surface of the heating coil, and the second flow path may be provided to guide air toward a bottom surface of the heating coil. 
     The induction heating cooker may further include an exhaust port hole located to correspond to a direction in which the first blower blows air, and provided to discharge air passing through the heating coil to an outside. 
     The induction heating cooker may further include a coil edge wall provided to surround the heating coil to guide air having heat exchanged with the heating coil to an outside. 
     The induction heating cooker may further include an intake port through which air is introduced from an outside, and electronic parts including a switching mode power supply located on a flow path between the intake port and the first blower. 
     In accordance with another aspect of the disclosure, an induction heating cooker is provided. The induction heating cooker includes a heating coil configured to heat a heating object, a first blower configured to blow air to the heating coil, a second blower disposed at one side in a horizontal direction with respect to the first blower and configured to blow air to the heating coil, a center flow path configured to guide the air blown by the first blower toward one part of the heating coil, a side flow path configured to guide the air blown by the second blower toward another part of the heating coil, and a second flow path configured to guide the air blown by the first blower toward another part of the heating coil and formed to be separated from the first flow path. 
     The induction heating cooker may further include a circuit board disposed in a space separated from a space in which the heating coil is located, and provided to be cooled by the second blower. 
     The induction heating cooker may include a third flow path configured to guide the air blown by the second blower toward one part of the circuit board, and a third flow path configured to guide the air blown by the second blower to another part of the circuit board and formed to be separated from the third flow path. 
     The induction heating cooker may further include an exhaust port positioned to correspond to a direction in which the first blower and the second blower blow air, and configured to discharge the air passing through the heating coil and the circuit board to the outside. 
     The induction heating cooker may further include a substrate edge wall provided to surround the circuit board to guide the air having heat exchanged in the circuit board to the exhaust port, and a coil edge wall provided to surround the heating coil the heating coil to guide the air having heat exchanged in the heating coil to the exhaust port. 
     The induction heating cooker may further include a plurality of ventilation holes through which air passing through the second flow path is discharged to the heating coil, and the plurality of ventilation holes may be disposed to be spaced apart from each other along a circumferential direction of the heating coil. 
     According to the technique of the disclosure, by effectively cooling the heating coil, it is possible to increase the output of the induction heating cooker and contribute to reducing the size. 
     Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a perspective view illustrating an induction heating cooker according to an embodiment of the disclosure; 
         FIG. 2  is a plan view illustrating main parts of an induction heating cooker according to an embodiment of the disclosure; 
         FIG. 3  is a cross-sectional view of the induction heating cooker taken along line III-III of  FIG. 2  according to an embodiment of the disclosure; 
         FIG. 4  is a cross-sectional view of the induction heating cooker taken along line IV-IV of  FIG. 2  according to an embodiment of the disclosure; and 
         FIG. 5  is a plan view illustrating a portion of an induction heating cooker in which a heating coil is mounted according to an embodiment of the disclosure. 
     
    
    
     Throughout the drawings, like reference numerals will be understood to refer to like parts, components, and structures. 
     DETAILED DESCRIPTION 
     The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. 
     The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents. 
     It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces. 
     Hereinafter, embodiments will be described in detail with reference to the drawings. In the following embodiments, for the sake of convenience in description of an induction heating cooker, a front side in a direction opposing a user is referred to as “front” and a rear side in the direction is referred to as “back”, and a left side when viewed from the front to the rear is “left” and a right side is referred to as “right”, and an upper side in a height direction during use of the induction heating cooker is referred to as “upper” and a lower side is referred to as “lower”. 
       FIG. 1  is a perspective view illustrating an induction heating cooker according to an embodiment of the disclosure.  FIG. 2  is a plan view illustrating main parts of an induction heating cooker according to an embodiment of the disclosure.  FIG. 3  is a cross-sectional view of the induction heating cooker taken along line III-III of  FIG. 2  according to an embodiment of the disclosure.  FIG. 4  is a cross-sectional view of the induction heating cooker taken along line IV-IV of  FIG. 2  according to an embodiment of the disclosure.  FIG. 5  is a plan view illustrating a portion of an induction heating cooker in which a heating coil is mounted according to an embodiment of the disclosure. For the sake of convenience in description, in  FIG. 1 , a top plate  7  and a manipulation portion  9  are indicated by a double-dashed line. In addition, in  FIG. 2 , a heating coil  13  is schematically indicated by a double-dashed line and indicated by hatching. 
     An induction heating cooker  1  according to the embodiment is provided in a type of a built-in induction heating (IH) cooking heater that is mounted and assembled in an opening installed into a kitchen countertop, and configured to heat a heating object X, such as a frying pan or pot, using the principle of electromagnetic induction. 
     Referring to  FIG. 1 , the induction heating cooker  1  is provided in a double-burner type induction heating cooker with two heating portions  3  serving as a loading place for the heating object X on which induction heating is performable. The two heating portions  3  are provided at intervals in the left-right direction. The induction heating cooker is a double burner type induction heating cooker having two heating portions  3  capable of coping with all types of metal, and specifically, the two heating portions  3  are each configured to induction-heat not only magnetic stainless or steel, but also non-magnetic and low-resistance metal, such as aluminum and copper. 
     Referring to  FIGS. 1 to 4 , the induction heating cooker  1  includes a main body  5 , a top plate  7 , a manipulation portion  9 , a cabinet  11 , a heating coil  13 , a blower device  15 , and a control board  17 . The cabinet  11 , the heating coil  13 , the blower device  15 , and the control board  17  are provided with the same configuration for each of the heating portions  3 , and are accommodated in the main body  5 . 
     Main Body 
     The main body  5  has an outer edge corresponding to a space in which the induction heating cooker  1  is installed, and is formed in a substantially rectangular box shape that is open at an upper side thereof The main body  5  is mainly formed of sheet metal or the like. A frame-shaped bracket  19  formed of sheet metal or the like is assembled to a rim around the opening of the main body  5 . A plurality of intake ports  21  are formed in a rear wall of the main body  5 . A plurality of exhaust ports  23  are formed in a front wall of the main body  5 . The intake ports  21  and the exhaust ports  23  are slit-shaped openings extending in the vertical direction, and are formed at intervals in the left and right directions in each of the rear wall and the front wall of the main body  5 . 
     Top plate 
     The top plate  7  is provided on an upper part of the main body  5  through the bracket  19  and covers the opening of the main body  5 . A gap between a portion exposed from the bracket  19  at four corners of the main body  5  and the top plate  7  is sealed with a seal member  25  formed of polyurethane or the like. The top plate  7  is a substantially rectangular plate body formed of glass or ceramic having high heat resistance, and constitutes a loading surface on which a heating object X is placed. Position marks (not shown) representing the positions of the respective heating portions  3  are indicated on the loading surface. 
     Manipulation Portion 
     The manipulation portion  9  is provided in a panel shape and located between the bracket  19  and the top plate  7  at a front side area of the main body  5 . Although not shown, the manipulation portion  9  has a left manipulation portion and a right manipulation portion. The left manipulation portion displays a heating level for the heating object X loaded on the heating portion  3  on the left side while receiving an input. The right manipulation portion displays a heating level for the heating object X loaded on the heating portion  3  on the right side while receiving an input. Such a left manipulation portion and a right manipulation portion may each include, for example, a display provided as a liquid crystal display device and a touch panel. 
     Cabinet 
     The cabinet  11  is provided on both left and right sides of the front side area of the main body  5 . The cabinet  11  is an example of a partition member. The cabinet  11  has a partition plate portion  27 , a coil edge wall  29 , and a substrate edge wall  31 . The partition plate portion  27  partitions the interior of the main body  5  in the vertical direction. In this way, the space in the main body  5  is divided into an upper space  33  positioned above the partition plate portion  27  and a lower space  35  positioned below the partition plate portion  27 . The upper space  33  corresponds to a first space. 
     The partition plate portion  27  is provided at a rear right side thereof with a first duct  37  that extends to the left side toward the front. The first duct  37  has a rear end that is open to the rear of the cabinet  11 , and has a front end that is open to the front at the upper side of the partition plate portion  27 . The partition plate portion  27  is provided at a center portion and a rear side thereof with a second duct  39  in which a region corresponding to the heating coil  13  is extended substantially as a whole. The second duct  39  is formed in a bulge at a lower side of the partition plate portion  27 . 
     The second duct  39  has a rear end that is open to the rear of the cabinet  11 . The partition plate portion  27  is provided in the central portion thereof with a first ventilation hole  41  having a large diameter. The first ventilation hole  41  communicates a space  40  in the second duct  39  with the upper space  33 . The shape of the first ventilation hole  41  is, for example, a circular shape. The space  40  in the second duct  39  is partitioned from the upper space  33  by the cabinet  11  (the partition plate portion  27 ). The space  40  corresponds to a second space. 
     The second duct  39  is provided therein with a splitting wall  43  that divides a flow path from the rear end opening to the first ventilation hole  41  into two parts. The splitting wall  43  has a separation wall  45 , a bypass wall  47 , and a lead-out wall  49 . 
     The separation wall  45  extends in a forward direction from the rear end opening of the second duct  39  toward the first ventilation hole  41 . The splitting wall  43  divides air blown inward from the rear end opening of the second duct  39  into the right side and left sides. The bypass wall  47  extends in an arc shape surrounding the first ventilation hole  41  except for a part of the front side of the first ventilation hole  41  when viewed from above. The bypass wall  47  is connected to the separation wall  45  and allows the air separated by the separation wall  45  to pass around the first ventilation hole  41  and flow forward. 
     The lead-out wall  49  extends from an outer peripheral wall of the second duct  39  at a front of the first ventilation hole  41 , passing through open ends of the front side of the bypass wall  47 , to a position corresponding to the inside of the first ventilation hole  41 . The lead-out wall  49  allows the air passed around the first ventilation hole  41  by the bypass wall  47  to flow through the first ventilation hole  41  in a separated state. The space  40  in the second duct  39  includes a left flow path  51  and a right flow path  53  bypassing on the left side of the first ventilation hole  41  and bypassing on the right side of the first ventilation hole  41 , respectively. 
     Portions of the partition plate portion  27  corresponding to the left flow path  51  and the right flow path  53  around the first ventilation hole  41 , that is, the upper wall of the second duct  39 , are formed with a plurality of second ventilation holes  55 . The plurality of second ventilation holes  55  are spaced apart from each other in the circumferential direction around the first ventilation hole  41 , and are provided to form a radial shape centered on the first ventilation hole  41 . Similar to the first ventilation hole  41 , the second ventilation hole  55  is a hole that communicates the space  40  (the left flow path  51  or the right flow path  53 ) in the second duct  39  with the upper space  33 . The shape of the second ventilation hole  55  is, for example, a circular shape having a diameter smaller than that of the first ventilation hole  41 . 
     A third duct  57  extending in the front-rear direction is provided on the right side of the partition plate portion  27 . The third duct  57  is formed in a bulge at a lower side of the partition plate portion  27  while extending from a position overlapping the first duct  37  via the right side of the second duct  39  to a position near the rear end of the partition plate portion  27  when viewed from above. The third duct  57  has a rear end located below the rear end opening of the first duct  37  and open to the rear of the cabinet  11 . A plurality of third ventilation holes  59  are formed in a lower wall of a front side area of the third duct  57 . The third ventilation hole  59  is a hole for communicating the interior of the third duct  57  with the lower space  35 . The shape of the third ventilation hole  59  is, for example, a slit shape extending in the left-right direction. 
     The coil edge wall  29  is integrally formed with the partition plate portion  27 . The col edge wall  29  is provided on the outer periphery of the partition plate portion  27  and extends upward from the partition plate portion  27 . The coil edge wall  29  surrounds the upper space  33  between the top plate  7  and the coil edge wall  29  in three directions corresponding to both left and right sides and the rear side, and allows the upper space  33  to be open to the front in which the exhaust port  23  is provided. The coil edge wall  29  has a rear side wall, a lower portion of which is formed with an upper vent  61  open rearward. The upper vent  61  is located above the rear end opening of the second duct  39 . 
     The substrate edge wall  31  is integrally formed with the partition plate portion  27 . The substrate edge wall  31  is provided on the outer periphery of the partition plate portion  27  and extends downward from the partition plate portion  27 . The substrate edge wall  31  surrounds the lower space  35  in three directions corresponding to both left and right sides and the rear side, and allows the lower space  35  to be open to the front in which the exhaust port  23  is provided. The substrate edge wall  31  has a rear side wall, a right portion of which is formed with a lower vent  63  that is open rearward. The lower vent  63  is located below the rear end opening of the third duct  57 . 
     Heating Coil 
     Referring to  FIG. 5 , the heating coil  13  is supported by a coil base  65  on the partition plate portion  27  of the cabinet  11  and disposed in the upper space  33 . The coil base  65  is formed in an approximately disk shape. Ferrite is substantially radially buried in the coil base  65 . The heating coil  13  is a horizontal dual coil for induction-heating the heating object X loaded on the top plate  7 , and includes an inner coil  67  and an outer coil  69  provided on the same plane in a concentric circle. The inner coil  67  is disposed inside the outer coil  69  and is electrically connected to the outer coil  69 . 
     The inner coil  67  and the outer coil  69  are each formed by winding a coil wire  71 , referred to as a Ritz wire or a flat wire a plurality of turns. Between the coil wires  71  adjacent to each other in each of the inner coil  67  and the outer coil  69 , a gap through which air may flow is provided. The inner coil  67  is disposed on the first ventilation hole  41  of the cabinet  11 . The plurality of second ventilation holes  55  provided in the cabinet  11  at a plurality of locations spaced apart from each other in the circumferential direction of the outer coil  69  are oriented toward the opening. The gap  73  between the coil wires  71  in the outer coil  69  is provided at a position corresponding to the second ventilation hole  55 . 
     A sensor support  75  is provided at the center of the coil base  65 . A temperature sensor  77  is mounted on the sensor support  75 . As the temperature sensor  77 , a contact-type temperature sensor, such as a thermistor, may be used. The temperature sensor  77  is provided in close contact with a lower surface of the top plate  7 , and senses the temperature of the heating object X loaded on the heating portion  3  over the top plate  7 . The temperature sensor  77  may be a non-contact type temperature sensor, such as an infrared sensor. The detected value of the temperature sensor  77  is transmitted to the control board  17 . 
     Blower Device 
     The blower device  15  allows external air to be introduced into the main body  5  from the intake port  21 , generates a flow of air flowing from the intake port  21 , passing through the heating coil  13  and the control board  17 , and directed to the exhaust port  23  in the main body  5 , and discharges the air in the main body  5  to the outside from the exhaust port  23 . The blower device  15  has a first blower  79  and a second blower  81 . The first blower  79  and the second blower  81  are disposed at different positions in the horizontal direction. 
     The first blower  79  is disposed behind the central portion of the cabinet  11  in the left-right direction. The first blower  79  has a casing  83  and an electric fan  85  accommodated in the casing  83 . The first blower  79  may be provided using a centrifugal blower that has a blower fan (referred to as a sirocco fan) as the electric fan  85 . The first blower  79  is provided in a posture with the rotation axis of the electric fan  85  oriented in the vertical direction. The first blower  79  allows air to be introduced from an inlet  87  provided in a lower portion of the casing  83  by the rotating operation of the electric fan  85 , and allows the air to be blown from an outlet  89  of the casing  83  facing forward. 
     The first blower  79  is accommodated in a case  91 . An opening  93  exposing the air inlet  87  of the first blower  79  is formed on a lower surface of the case  91 . A discharge flow path  95  through which air blown by the first blower  79  circulates is formed in a front side area of the case  91 . The discharge flow path  95  has a front end that is open toward the front of the case  91 . The opening of the front end of the discharge flow path  95  is connected to the rear end opening of the second duct  39  and the upper vent  61  as a front end of the case  91  is adjacent to the rear wall of the cabinet  11 . In the direction in which the first blower  79  blows air from the upper vent  61  to the upper space  33  through the discharge flow path  95 , the exhaust port  23  is positioned. 
     The second blower  81  is disposed on the right side of the first blower  79  behind the cabinet  11 . The second blower  81  has a casing  97  and an electric fan  99  accommodated in the casing  97 . For the second blower  81 , an axial blower having a propeller fan may be used as the electric fan  99 . The second blower  81  is provided in a posture with the rotation axis of the electric fan  99  oriented in the front-rear direction. The second blower  81  allows air to be introduced from an inlet  101  provided at a rear side of the casing  97  by the rotational operation of the electric fan  99 , and allows the air to be blown from an outlet  103  provided at a front side of the casing  97 . 
     A flow path member  105  having a block shape is provided between the second blower  81  and the rear wall of the cabinet  11 . The flow path member  105  is provided with a flow path connecting passage  107  opening in a direction in which air is blown from the outlet  103 . A rear end opening of the flow path connection passage  107  is connected to the outlet  103  of the second blower  81 . A front end opening of the flow path connection passage  107  is connected to the rear end opening of the first duct  37 , the rear end opening of the third duct  57 , and the lower vent  63  as a front end of the flow path member  105  is adjacent to the rear wall of the cabinet  11 . In the directions in which the second blower  81  blows air from the first duct  37  to the upper space  33  and blows air from the lower vent  63  to the upper space  33  through the flow path connection passage  107 , the exhaust ports  23  are located. 
     Control Board 
     The control board  17  controls the heating operation of the heating coil  13  and the blowing operation of the first blower  79  and the second blower  81 . The control board  17  has a first circuit board  109  and a second circuit board  111 . 
     The first circuit board  109  is disposed in the lower space  35  below the cabinet  11 . On the first circuit board  109 , an inverter circuit  113 , other electronic components, a heat sink  115 , and the like are mounted as a power supply circuit. The first circuit board  109  applies a high frequency current of about 20 kHz to 100 kHz to the heating coil  13 . The magnitude of the high-frequency current applied to the heating coil  13  is controlled by the first circuit board  109  based on the detection value of the temperature sensor  77  or the like according to the heating level set by the manipulation portion  9 . 
     The second circuit board  111  is disposed behind the cabinet  11 . Electronic components  116 , such as a switching mode power supply, are mounted on the second circuit board  111 . The second circuit board  111  supplies power to the first blower  79  and the second blower  81 , and drives the first blower  79  and the second blower  81 . The amount of air blown by the blower device  15 , that is, the number of rotations of the fan of the first blower  79  and the number of rotations of the fan of the second blower  81  are controlled by the second circuit board  111 . 
     Flow Path in Main Body 
     The main body  5  is provided therein with a first flow path  117  and a second flow path  119  serving as flow paths through which air for cooling the heating coil  13  flows by the operation of the blower device  15 . 
     The first flow path  117  is a flow path that allows air blown by the blower device  15  toward the heating coil  13  to be supplied from an outer peripheral side. The first flow path  117  has a center flow path  121  and a side flow path  123 . 
     The center flow path  121  is formed by the discharge flow path  95  of the case  91  accommodating the first blower  79 , the upper vent  61  of the cabinet  11 , and the upper space  33  above the partition plate portion  27  in the main body  5 . The center flow path  121  supplies the air blown by the first blower  79  to the heating coil  13  from an immediately rear side of the heating coil  13 . 
     The side flow path  123  is formed by the flow path connecting passage  107  of the flow path member  105 , a space in the first duct  37  of the cabinet  11 , and the upper space  33  on the partition plate portion  27  in the main body  5 . The side flow path  123  supplies the air blown by the second blower  81  to the heating coil  13  from an immediate rear side of the heating coil  13 . 
     The second flow path  119  is a flow path that allows air blown by the first blower  79  to be supplied toward the heating coil  13  from the lower side of the heating coil  13 . The second flow path  119  is formed by the discharge flow path  95  of the case  91  accommodating the first blower  79 , the left flow path  51  and the right flow path  53  in the second duct  39  of the cabinet  11 , and the first ventilation hole  41  and the plurality of second ventilation holes  55  of the partition plate portion  27 . 
     In the main body  5 , a third flow path  125  and a fourth flow path  127  are provided as flow paths through which air for cooling the first circuit board  109  flows. 
     The third flow path  125  is a flow path that allows air blown by the second blower  81  to be supplied toward the first circuit board  109  from the outer periphery side. The third flow path  125  is formed by the flow path connecting passage  107  of the flow path member  105 , the lower vent  63  of the cabinet  11 , and the lower space  35  below the partition plate portion  27  in the body  5 . 
     The fourth flow path  127  is a flow path that allows air blown by the second blower  81  to be supplied toward the first circuit board  109  from the upper side. The fourth flow path  127  is formed by the flow path connecting passage  107  of the flow path member  105 , a space in the third duct  57  of the cabinet  11 , and the plurality of third ventilation holes  59  provided on the front portion of the third duct  57 . 
     In the induction heating cooker  1  of the above configuration, when the first blower  79  and the second blower  81  are driven, external air is introduced into the main body  5  from the intake port  21  and the air, introduced into the main body  5 , passes through the second circuit board  111 , and then is blown to the center flow path  121  and the second flow path  119  by the first blower  79 , and then blown to the side flow path  123 , the third flow path  125 , and the fourth flow path  127  by the second blower  81 . 
     In this case, the air volume circulating through the second flow path  119  is larger than the air volume circulating through the first flow path  117 . Here, the air volume circulating through the first flow path  117  is an average value of the air volume circulating through the center flow path  121  and the air volume circulating through the side flow path  123 . The air volume circulating through the first flow path  117  may be one of the air volume circulating through the center flow path  121  and the air volume circulating through the side flow path  123  (for example, a larger air volume). In addition, the air volume circulating through the second flow path  119  is the air volume passing through the rear end opening of the second duct  39 . The air volume circulating through the second flow path  119  may be one of the air volume circulating through the left flow path  51  and the air volume circulating through the right flow path  53 , and may be an average value of the air volume circulating through the left flow path  51  and the air volume circulating through the right flow path  53 . 
     The air blown into the center flow path  121  by the first blower  79  is supplied from the rear side of the heating coil  13 , and the air after passing through the heating coil  13  is directed toward the exhaust port  23  and discharged out of the main body  5  from the exhaust port  23 . The air blown into the second flow path  119  by the first blower  79  and discharged from the first ventilation hole  41  and the second ventilation hole  55  on the lower side of the heating coil  13  is supplied to the heating coil  13 , and while joining the air supplied from the first flow path  117  (the center flow path  121  and the side flow path  123 ) passes through the heating coil  13  and then is directed toward the exhaust port  23  to be discharged out of the main body  5  from the exhaust port  23 . 
     The air blown to the side flow path  123  by the second blower  81  is supplied from the right rear side of the heating coil  13 , and while joining the air supplied from the center flow path  121 , passes through the heating coil  13  and then is directed toward the exhaust port  23  to be discharged out of the main body  5  from the exhaust port  23 . The air blown to the third flow path  125  by the second blower  81  is supplied from the rear side of the first circuit board  109 , and the air, passing through the first circuit board  109 , is directed toward the exhaust port  23  to be discharged out of the main body  5  from the exhaust port  23 . The air blown to the fourth flow path  127  by the second blower  81  is supplied to the front portion of the first circuit board  109  from the upper side of the first circuit board  109 , and while joining the air blown to the third flow path  125 , the air is directed to the exhaust port to be discharged out of the main body  5  from the exhaust port  23 . 
     In this way, the flow of air generated in the main body  5  by the driving of the first blower  79  and the second blower  81  cools the heating coil  13 , the first circuit board  109 , and the second circuit board  111 . The second circuit board  111  is cooled by being exposed to air directed from the intake port  21  to the first blower  79  and the second blower  81 . The first circuit board  109  is cooled by being exposed to air supplied from the rear side thereof through the third flow path  125  and air supplied from the upper side thereof through the fourth flow path  127 . The heating coil  13  is cooled by being exposed to air supplied from the rear side thereof through the first flow path  117  and air supplied from the lower side thereof through the second flow path  119 . 
     Effect of Example 
     With the induction heating cooker  1  according to the embodiment, air is blown to the heating coil  13  in two directions from the rear side and the lower side by the first blower  79  and the second blower  81 , so that the heating coil  13  can be cooled efficiently. Therefore, high frequency current, which may cause the heating coil  13  to generate relatively large heat, may be applied to the heating coil  13 , so that high frequency or high current of current applied to the heating coil can be achieved, thereby providing the induction heating cooker  1  with high output of power. In addition, since the heating coil  13  is efficiently cooled, the size of the first blower  79  and the second blower  81  is reduced, so that the size of the induction heating cooker  1  can be reduced. 
     With the induction heating cooker  1  according to the embodiment, the exhaust ports  23  are located in a direction in which the first blower  79  blows air to the center flow path  121  and in a direction the second blower  81  blows air to the side flow path  123 , and air is blown toward the exhaust ports  23  by the first blower  79  and the second blower  81 , so that the air having a temperature elevated in the main body  5  can be smoothly discharged out of the main body  5  through the exhaust port  23  while being suppressed from staying around the heating coil  13 . Such a configuration is beneficial in efficiently cooling the heating coil  13 . 
     With the induction heating cooker  1  according to the embodiment, since the upper space  33  in which the heating coil  13  is disposed is surrounded by the coil edge wall  29  of the cabinet  11 , air having a temperature elevated due to heat generation of the heating coil  13  may be suppressed from leaking out to the surroundings, and the temperature elevated air may be efficiently discharged out of the main body  5  through the exhaust port  23 . Such a configuration is beneficial in efficiently dissipating heat of the induction heating cooker  1  by preventing heat from staying in the main body  5 . 
     With the induction heating cooker  1  according to the embodiment, since the lower space  35  in which the first circuit board  109  is disposed is surrounded by the substrate edge wall  31  of the cabinet  11 , the air having a temperature elevated due to heat generation of the first circuit board  109  in the main body  5  can be suppressed from leaking to the surroundings, and efficiently discharged out of the main body  5  through the exhaust port  23 . Such a configuration is also beneficial in efficiently dissipating the heat of the induction heating cooker  1 . 
     With the induction heating cooker  1  according to the embodiment, since the air blown to the second duct  39  by the first blower  79  is supplied to a plurality of locations at intervals in the circumferential direction of the heating coil  13  through the first ventilation hole  41  and the second ventilation holes  55  provided in the partition plate portion  27 , the heating coil  13  is cooled at the plurality of locations in the circumferential direction and thus can be efficiently cooled as a whole. 
     With the induction heating cooker  1  according to the embodiment, the air blown into the second duct  39  by the first blower  79  is divided between the left flow path  51  and the right flow path  53  by the splitting wall  43 , so that a large amount of air is prevented from being circulated to the first ventilation hole  41  or a specific second ventilation hole  55 , and air is evenly discharged not only from the first ventilation hole  41  but also each second ventilation hole  55 . Such a configuration is beneficial in efficiently cooling the heating coil  13  as a whole. 
     With the induction heating cooker  1  according to the embodiment, the first circuit board  109  is separated from the heating coil  13  by the cabinet  11  including the second flow path  119  (the left flow path  51  and the right flow path  53 ) and the third flow path  125 , so that heat generated by the heating coil  13  is prevented from exerting an adverse effect on the inverter circuit  113  or the like. Accordingly, the reliability of the induction heating cooker  1  can be increased. 
     With the induction heating cooker  1  according to the embodiment, the blower device  15  allows the heating coil  13  to be supplied with air from a lower side thereof in an amount larger than that supplied from an outer periphery side thereof Since the heating coil  13  comes in contact with the air blown from the lower side of the heating coil  13  in a larger area compared to the air blown from the outer periphery side, the efficiency of heat dissipation of the heating coil  13  may be enhanced. Therefore, blowing a relatively large amount of air to the heating coil  13  from the lower side contributes to increasing the cooling efficiency of the heating coil  13 . 
     With the induction heating cooker  1  according to the embodiment, the blower device  15  has the first blower  79  and the second blower  81 , and the first blower  79  and the second blower  81 , which are disposed at different positions in the horizontal direction, secure the total volume of air blown to the first flow path  117  and the second flow path  119  by the first blower  79  and the second blower  81  while miniaturizing the first blower  79  and the second blower  81 . Such a configuration contributes to reducing the size of the induction heating cooker  1 . 
     In the above, a preferred embodiment has been described as an example of the present disclosure. However, the features of the present disclosure are not limited thereto, and may be applied to various forms in which appropriate changes, substitutions, additions, omissions, and the like are implemented. In addition, some of the components described in the accompanying drawings and detailed description may also include components that are not needed. Therefore, even when such constituent elements are described in the accompanying drawings and detailed description, such constituent elements may not be recognized as needed. 
     For example, the following configuration is also possible for the above embodiment. 
     In the above embodiment, the intake port  21  is formed in the rear wall of the main body  5 , the exhaust port  23  is formed in the front wall of the main body  5 , and the blower device  15  generates a flow of air directed from the intake port  21  on the rear side toward the exhaust port  23  on the front side in the main body  5 , but the disclosure is not limited thereto. For example, the intake port  21  and the exhaust port  23  may be respectively formed on the left side and the right side in the rear wall of the main body  5 . In this case, the blower device  15  may be provided to generate a flow of air from the intake port  21  flowing through the heating coil  13  and the control board  17  and then making a U-turn, flowing toward the exhaust port  23 . 
     In the above embodiment, the volume of air circulating through the second flow path  119  is provided to be larger than that circulating through the first flow path  117 , but the disclosure is not limited thereto. The volume of air circulating through the second flow path  119  and the volume of air circulating through the first flow path  117  may be similar to each other. The volume of air flowing through the second flow path  119  may be smaller than the volume of air flowing through the first flow path  117 . 
     In the above embodiment, the induction heating cooker  1  is illustrated as having a flow path in which air is blown toward the heating coil  13  from the rear side and the lower side in the main body  5  by the blower device  15 , but the disclosure is not limited thereto. For example, the flow path of the main body  5  in which the blower device  15  blows air may be configured to blow air toward the heating coil  13  from one of the left and right sides, and the lower side of the heating coil  13 . The flow path of the main body  5  may be variously provided as long as it has a flow path allowing air blown by the blower device  15  to be supplied toward the heating coil  13  from the outer periphery side and a flow path allowing air blown by the blower device  15  to be supplied toward the heating coil  13  from the lower side, in the main body  5 . 
     In the above embodiment, the blower device  15  is illustrated as having the first blower  79  and the second blower  81 , but the disclosure is not limited thereto, and the blower device  15  may include only one blower or three or more blowers. 
     In the above embodiment, the first blower  79  is illustrated as blowing air to the first flow path  117  and the second flow path  119 , and the second blower  81  is illustrated as blowing to the first flow path  117 , the third flow path  125 , and the fourth flow path  127 , but the disclosure is not limited thereto. For example, the first blower  79  may blow air only to the first flow path  117 , the second blower  81  may blow air only to the second flow path  119 , and a separate blower (a third blower) may blow air to the third flow path  125  and the fourth flow path  127 . 
     In the above embodiment, a centrifugal blower is illustrated as the first blower  79  and an axial blower is illustrated as the second blower  81 , but the disclosure is not limited thereto. As the first blower  79 , an axial flow blower, a mixed flow blower, or a cross-flow blower may be used. In addition, as the second blower  81 , a centrifugal fan, a mixed flow fan, or a cross-flow fan may be used. 
     In the above embodiment, the induction heating cooker  1  is illustrated as a double-burner type induction heating cooker having two heating portions  3  each capable of coping with all types of metals, but the disclosure is not limited thereto. For example, in the induction heating cooker  1 , only one of the two heating portions  3  may be provided as a single all-metal available type heating portion, that is, a type capable of coping with all metals, or both of the two heating portions  3  may be provided as a magnetic exclusive type for magnetic materials, such as stainless steel or iron having magnetic properties. In addition, the induction heating cooker  1  may have one heating portion  3  or three or more heating portions  3 . 
     In the above embodiment, the induction heating cooker  1  is illustrated as a built-in type induction heating cooker, but the disclosure is not limited thereto. The built-in induction heating cooker  1  is only an example, and the technology of the disclosure may also be applied to a mounting type induction heating cooker installed on a kitchen countertop. 
     As described above, the technique of the disclosure is useful for an induction heating cooker that may cool the heating coil by blowing air. 
     While the disclosure has been shown described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.