JP6670567B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker.

  The induction heating cooker is a device that performs heating cooking by using Joule heating by eddy current generated at the bottom of a pan when a magnetic field line generated by flowing a high-frequency current through a heating coil passes through a metal pan. At the time of heating, heat is generated not only from a pan but also from a heating coil and a substrate for controlling the heating coil. Therefore, blast cooling is performed using a fan device.

  In addition, induction heating cookers placed in system kitchens are mainly configured to perform induction heating of a cooking pot on a top plate and cooking such as grilled fish in a heating room (grill storage) equipped with a heat source such as an electric heater. It is.

  In a conventional induction heating cooker, the main components to be cooled are a plurality of heating coils and a board, and the heating coil is housed in an upper space near a top plate above the main body, and the board is housed in a surplus space on a side of the grill portion in terms of structure. The configuration is general (Patent Document 1).

  The intake and exhaust ports of the main body arranged in the system kitchen have many intake and exhaust paths in which the intake port is arranged below the top plate and only the exhaust port is provided on the top plate, as in Patent Document 1. In addition, a configuration is adopted in which it is difficult for spills due to boiling or bumping in the cooking pot during heating and steam in the pot to flow into the inside of the main body.

  In addition, when the induction heating cooker is stored in the system kitchen frame, the flange is formed at the outer peripheral end of the top plate to hold the main body, and the liquid spilled during heating of the cooking pot on the top plate ( A packing is provided on the outer peripheral side of the top plate so that water does not easily enter the gap between the system kitchen frame and the top plate (flange portion).

  Alternatively, even if the heating operation is performed in a state where the top plate is cracked or broken by mistake, a structure that suppresses the spilled liquid from entering the charged portion (exposed portion of the circuit pattern) of the substrate. Has been taken.

  On the other hand, since the dimensions of most system kitchen frames in Japan are specified, the maximum external dimensions of induction heating cookers are also roughly determined, making them optimal for cooling heating coils and substrates in a limited space. It is necessary to construct an airway.

  In order to efficiently heat the cooking pot with the heating coil, it is important to optimally lay out the electronic components of the inverter circuit that supplies power to the heating coil. The optimum layout generally means that components are arranged in an ideal circuit pattern in which the distance between components is small (high integration) and is not easily affected by other electronic components such as a power supply (low noise). Therefore, it is possible to arrange the control board on one surface as in the induction heating cooker described in Patent Document 2 and to arrange the components such that there is no wiring (jumper wire or the like) between the boards or across the electronic components on the board. A circuit that is effective for improving the efficiency and that has a good heating efficiency can also suppress the generation of electromagnetic noise.

JP 2011-3372 A JP 2014-142125 A

  A conventional general induction heating cooker as disclosed in Patent Literature 1 has a circuit configuration in which a plurality of substrates are divided, stacked, and stored on the side of a grill storage, and have a plurality of wirings connecting the substrates ( Since optimization is restricted), the heating efficiency is deteriorated. Further, the fan device for cooling the heating coil and the substrate is housed in a narrow space, and various members are arranged near the intake / exhaust portion of the fan device. For this reason, the turbulence of the intake air flow due to the wind speed distribution caused by the arrangement of the members and the increase of the ventilation resistance deteriorate the air blowing performance of the fan device, and lower the component cooling performance and increase the fan noise.

  On the other hand, in the case of an induction heating cooker having a grill storage which is the most mainstream configuration, as in Patent Document 2, it is not possible to store a plurality of fan devices and substrates arranged on one surface between the grill storage and a top plate. Insufficient volume and difficult. In a general system kitchen, the gap between the grill storage and the top plate is only about 60 mm, and the volume of the grill storage is about half or more of the width of the main body. For this reason, when the substrate is to be placed on the substantially same surface and housed in the main body, the gap in the height direction from the grill storage to the heating coil is about 20 to 30 mm, and the component mounting volume is smaller than the conventional one (Patent Document 1). Also decreases. Here, a heat sink for mounting and emitting heat to electronic components that generate high heat is mounted on the board, and a heat sink having a height of about 40 to 50 mm is used for a board that is stacked and stored on the side of the grill storage. Since the cooling of electronic components that generate high heat is determined by the volume of the heat sink and the amount of air flowing through the heat sink, if the volume of the heat sink is reduced, a large-sized fan device with high pressure is required. That is, it is impossible to simply store the substrates stacked on the side of the grill storage side under the heating coil.

  Further, when the substrate is arranged below the heating coil, the substrate has a positional relationship closer to the top plate than in the related art. For this reason, the possibility that the liquid comes into contact with the substrate due to the infiltration of the liquid is higher than in the state where the substrates are concentrated and stacked on one side as in Patent Document 1. That is, the distance between the exhaust port of the top plate and the substrate and the distance between the outer peripheral edge of the top plate and the substrate are significantly shorter. Furthermore, in the case of cracking or breakage of the top plate, there is a possibility that liquid may enter the entire top plate.

  In view of the above, the present invention provides an induction heating cooker having a substrate layout in which a circuit pattern for driving with high efficiency is mounted and a substrate layout in which a liquid pattern is prevented, in which a substrate is arranged below a heating coil so that electronic components can be optimally arranged. The task is to provide

In order to solve the above problems, the induction heating cooker according to the present invention, the present body, a top plate that is installed to the body top surface, a plurality of heating coils provided below the said top plate, the heating coil A board on which electronic components such as an inverter for supplying high-frequency power are mounted, a waterproof plate provided in a gap between a top plate and the heating coil, a fan device for cooling the board, and a grill built in the main body In the induction heating cooker provided with a refrigerator, the substrate is disposed between the plurality of heating coils and the grill refrigerator, and a substrate cover that covers the substrate is provided between the plurality of heating coils and the substrate. The substrate cover includes a discharge unit that supplies air that has cooled the substrate to the heating coil, and the waterproof plate is provided to cover an opening of the discharge unit from above.

  The details will be described in an embodiment for carrying out the invention.

  ADVANTAGE OF THE INVENTION According to this invention, the invasion of water into the inside of a main body is suppressed, a failure is few, and a safe induction heating cooker can be provided.

1 is a perspective view of an induction heating cooker according to a first embodiment. Exploded view of the induction heating cooker shown in FIG. FIG. 1 is a side sectional view taken along line AA shown in FIG. 1. Exploded perspective view of the fan device shown in FIG. FIG. 1 is a front sectional view taken along line BB shown in FIG. 1. FIG. 1 is a front sectional view taken along line CC shown in FIG. 1. Layout of substrate and fan device in substrate cover cut along line DD shown in FIG. FIG. 8 is a perspective view of a heat sink that cools the high heat generation component shown in FIG. 8. FIG. 10 is a circuit diagram of a current resonance inverter configured by the high heat-generating components of FIG. 9. Top view showing air flow in induction heating cooker Side sectional view when the heating coil is installed in FIG. Exploded perspective view of the heating coil of FIG. Modified example of side sectional view of induction heating cooker shown in FIG. Exploded perspective view of an induction heating cooker according to a second embodiment. Side sectional view of the heating coil of FIG. Top plate of induction heating cooker according to embodiment 2 Example 3 Top Plate

  Embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In addition, front and rear, up and down, and left and right are defined as shown in FIG. 1 and the like based on the user's line of sight facing the induction heating cooker Z (see FIG. 1).

<Configuration of induction heating cooker>
FIG. 1 is a perspective view of the induction heating cooker Z of the first embodiment, and FIG. 2 is an exploded view of FIG. First, as an example, a case will be described in which the induction heating cooker Z (see FIG. 1) is a built-in type induction heating (IH) cooking heater provided with a grill storage 5 for heating an object to be cooked by an electric heater or the like.

  The induction heating cooker Z is a device that generates an eddy current at the bottom of a cooking pot (not shown) made of metal and causes the cooking pot itself to generate heat by Joule heat due to the eddy current. The above-mentioned eddy current is generated by causing a high-frequency current of, for example, about 20 kHz to 40 kHz to flow through the heating coils 3a, 3b, and 3c to change the magnetic flux with time. The induction heating cooker Z mainly covers the main body 1, the top plate 2, the heating coils 3a, 3b, 3c, the substrates 7a, 7b placed on the substrate stands 73a, 73b, and the substrates 7a, 7b. Board covers 6a, 6b provided as described above, and a fan device 9. The main body 1 is a housing having an outer shell corresponding to a space (a predetermined left-right width, front-rear width, and height) in which the induction heating cooker Z is installed, and has a box shape (concave shape) with an open upper side. I have. This main body 1 is provided with a lower left grille storage 5, and substrates 7 a and 7 b mounted on board bases 73 a and 73 b above a partition plate 1 b covering the grill storage 5, and a lower casing constituting a fan device 9. 90b and the impeller 91 are arranged in a plane, and the outlet 95, which is the outlet of the fan device 9, is arranged at a height including the surfaces of the substrates 7a and 7b.

  The boards 7a, 7b are covered with board covers 6a, 6b, respectively, and an upper casing 90a constituting the fan device 9 is arranged alongside the board covers 6a, 6b, and the heating coils 3a, 3b, 3c, a display part P1 and the like are provided, and a top plate 2 is further provided so as to cover from above. Here, the electronic components 71 on the substrates 7a and 7b are integrated circuits, inverter circuits, capacitors, resistors, and the like that are used to supply a high-frequency current to the heating coils 3a and 3b and to drive the fan device 9. is there. The board bases 73a and 73b are insulating members (resin members) for fixing the boards 7a and 7b, and are fixed to the inner wall of the main body 1 and the partition plate 1b.

  The heating coils 3a, 3b, 3c are installed below the top plate 2, and a temperature sensor 34 for detecting the temperature of the pot bottom is installed near the center thereof. The heating coils 3a, 3b, and 3c are disposed downstream of the fan device 9, and after cooling air blown from the fan device 9 cools the substrates 7a and 7b in the substrate covers 6a and 6b, the heating coils 3a, 3b, and 3c are located at the front corners of the main body. The heating coils 3a, 3b, 3c are cooled through the discharge section 60a. The heating coils 3a, 3b, and 3c are coils through which a high-frequency current flows by driving an inverter circuit described later, and are mounted on the coil base 31. In this embodiment, the heating coils 3a, 3b, and 3c are provided one each at the right, left, and back of the center in plan view. The coil base 31 is supported by three support members 32 (for example, springs), and an upward biasing force is applied by the support members 32. As a result, the heating coil is pressed against the lower surface of the plate 2, and the distance between the cooking pot and the heating coils 3a, 3b, 3c is kept constant.

  An inlet (not shown) is provided in the grill storage 5 on the front left side of the main body 1 for installing a food (not shown) by sliding back and forth. On the right front side of the main body 1, an operation panel P2 for mainly adjusting the degree of heating in the grill storage 5 is provided. The top plate 2 includes a plate-like glass (not shown) on which a cooking pot is placed, and a frame portion (not shown) that holds four sides of the plate-like glass, and is installed from above the main body 1. . The top plate 2 includes a three-port pan placement section 21 corresponding to the installation positions of the three heating coils 3a, 3b, and 3c, an operation section 22 for adjusting the heating of the cooking pan, and an exhaust opening H2. have. The exhaust opening H2 is a plurality of holes for discharging air blown out from the fan device 9, and is provided behind (the right side and the left side) of the top plate 2. FIG. 3 is a side sectional view taken along line AA shown in FIG.

  An intake opening H1 for taking in air from outside by driving the fan device 9 is provided on the back side of the main body 1 respectively. Air blown into the main body 1 from the fan device 9 is exhausted from an exhaust opening H2 provided behind the top plate 2.

  In addition, if an intake opening is provided, for example, on the lower side of the front in addition to the rear of the main body 1, relatively low-temperature air can be easily taken into the main body 1. Further, by providing the intake opening H1 on the back side far from the grill storage 5 located on the left side (see FIG. 2), it is possible to make it difficult to suck in the high temperature air taken in through the intake opening H1.

  FIG. 4 is a perspective view of the fan device 9 which is disposed substantially in a plane with the substrates 7a and 7b and is provided on the side of the substrate tables 73a and 73b. The fan device 9 is a centrifugal fan including an impeller 91, casings 90 a and 90 b provided so as to vertically sandwich the impeller 91, and a motor 92 penetrating the casing 90 a and connecting to the impeller 91. In other words, the impeller 91 is housed in a space surrounded by a casing 90a provided with a motor 92 and a casing 90b provided with an intake port 9a, and the rotating shaft 92a of the motor 92 is kept out of contact with the casings 90a and 90b. Is rotatably supported. Therefore, the fan device 9 has the rotating shaft 92 a of the impeller 91 in the vertical direction of the main body 1, sucks air from below, and blows air from the lateral discharge port 95 in two directions. The intake port 9a of the casing 90b has a bell mouth shape (not shown). That is, the fan device 9 is arranged on the upstream side of the substrates 7a and 7b, and when the motor 92 is driven, air is taken in from the intake port 9a and diverted in two directions from the discharge port 95, and the heat sink 8a of the substrates 7a and 7b is formed. , 8b (see FIG. 1).

  As shown in FIG. 3, a hollow portion (chamber portion F0) is provided below the fan device 9, that is, on the right side of the grill storage 5. The chamber portion F0 provided between the intake opening H1 and the fan device 9 reduces the wind speed distribution of the air flowing from the intake opening H1, and supplies an airflow with little turbulence along the bell mouth of the intake 9a.

  Therefore, separation of the flow at the impeller 91 downstream of the intake port 9a can be suppressed, and the impeller 91 can blow air while performing work efficiently. Therefore, the fan device 9 can be driven to rotate with a low noise and a large air volume, and becomes an induction heating cooker with a small operating sound. That is, when the fan device 9 is incorporated into the induction heating cooker Z, a predetermined increase in the pressure of the impeller 91 can be ensured, so that the rotation speed does not need to be increased more than necessary, and the operation can be performed with low noise.

  Further, the lower casing 90b of the fan device 9 protrudes below the partition plate 1b (see FIG. 1) on which the substrate table 73a is placed, so that the impeller having a large diameter and a large blade thickness can be easily stored. Has become.

The fan device 9 in the induction heating cooking has a sufficiently large pressure-air volume blowing characteristic with respect to the ventilation resistance (for example, 100 to 200 Pa) in the main body 1 so that the air volume required for cooling at low speed rotation ( For example, 1.0 to 1.5 m ³ / min) can be obtained, so that the substrates 7a and 7b and the heating coils 3a, 3b and 3c can be efficiently cooled, and it is easy to reduce operating noise during use. Become.

  The air blown out from the fan device 9 flows on the substrate 7a provided in the gap between the substrate stand 73a and the substrate cover 6a (F1), and the substrate cover moves toward the heating coil 3a installed on the substrate cover 6a downstream therefrom. It flows through the gap between 6a and the top plate 2 (F2). In this embodiment, a discharge section 60a for supplying air from the side toward the heating coil 3a is provided on the front side of the substrate cover 6a. The opening of the discharge unit 60a faces the side surface of the heating coil 3a, and the opening is not visible even when viewed from above in a plan view. This is to prevent the liquid from penetrating into the substrate cover from the opening of the ejection part 60a even if the liquid invades from the cracked part of the top plate.

  As shown in FIG. 3, the discharge port 95 of the fan device 9 is configured such that the intake port 9a communicating with the impeller 91 is located below the substrate table 73a, so that air is blown obliquely upward toward the substrate cover 6a. You. This configuration suppresses a temperature rise of the substrate cover 6a caused by providing the substrate 7a and the heating coil 3a close to each other via the substrate cover 6a. Since the temperature of the heating coil 3a during the induction heating cooking rises to a temperature of about 200 ° C., the temperature of the substrate cover 6a rises due to the radiant heat of the heating coil 3a. Therefore, by forming the discharge port 95 toward the substrate cover 6a and deviating the main flow toward the substrate cover 6a, thermal deformation due to radiant heat is suppressed.

  In the present embodiment in which the substrate 7a (7b) is provided on the grill warehouse 5, the distance between the heating coil 3a (3b, 3c) and the substrate 7a (7b) is shorter than in the conventional configuration in which the substrate is provided on the side of the grill warehouse. As a result, the main flow of the fan device 9 is inclined to the substrate cover 6a (6b) as in this configuration, so that heat is transferred to the substrate 7a via the substrate cover 6a. Heat can be prevented, and the entire components in the main body 1 can be efficiently cooled.

  Here, the cooling coil 3a is cooled, and the air (F2) flowing through the gap between the substrate cover 6a and the top plate 2 is discharged toward the exhaust opening H2 behind the main body 1. The exhaust opening H2 is covered with an exhaust cover 25 having a plurality of small-diameter holes formed in a metal plate, so that a liquid (not shown) flowing when a spill or the like occurs on the top plate is difficult to enter. I have. The exhaust cover 25 is detachable and can be removed and cleaned when it becomes dirty. Further, the liquid that has passed through the exhaust cover 25 is received by the water receiving portion 94 provided below the exhaust cover 25 to receive and drop the vigorously dropped droplets on a wide surface so that the liquid does not flow into the fan device 9 side. I have. A grid-like partition 94a is provided between the water receiving portion 94 and the motor 92 to suppress the liquid from entering the inside of the main body 1.

  Further, in the configuration of the present embodiment, by disposing the fan device 9 near the exhaust opening H2, the distance from the right exhaust opening H2 to the substrate 7a can be increased, and the liquid permeates into the charged portion of the substrate. It has a difficult structure. Therefore, the possibility of liquid intrusion of the substrate 7a into the exhaust opening H2 can be extremely reduced, and the present embodiment has a highly safe structure in which a failure hardly occurs. In the left exhaust opening H2, as shown in FIG. 1, a water receiving portion 1a is provided on the partition plate 1b, and the droplet that has passed through the exhaust cover 25 falls to the rear of the grill storage 5. Therefore, it is difficult to enter the substrate cover 6b.

  FIG. 5 is a front sectional view taken along line BB shown in FIG. 1, and FIG. 6 is a front sectional view taken along line CC shown in FIG. The heating chamber 50 in the grill storage 5 is a space in which cooking items such as grilled fish are arranged, for example, an electric heater (upper heater 51 and lower heater 52) as a heat source, and a grille on which fish and the like are placed. And a saucer 53 disposed below the grill 54. As described above, the heating chamber 50 is disposed in the left area in the main body 1 in a plan view, and the receiving tray 53 and the like inside the main body 1 are slidable in the front-rear direction.

  Note that the heat source of the heating chamber 50 is not limited to the electric heater, and the food may be heated by microwaves, steam, or a combination thereof. Alternatively, a temperature controller may be provided to heat the oven. FIG. 1 shows an induction heating cooker Z provided with a grill storage 5 having a half or more of the main body width.

  As shown in FIG. 3, the substrates 7 a and 7 b on which the electronic components 71 are mounted and the fan device 9 that allows air to flow through the air passages in the substrate covers 6 a and 6 b include an exhaust opening of the top plate 2. Since it is arranged near H2, the right area in the main body 1 shown in FIG. 5 showing the front section of the heating coil 3c and FIG. 6 showing the front section of the heating coils 3a and 3b is a space (chamber section F0). . As shown in FIG. 6, in this embodiment, the substrate 7a is divided below the right heating coil 3a, and the substrate 7b is divided below the left heating coil 3b. An inverter circuit for supplying power to the heating coil 3a is mounted on the substrate 7b, and an inverter circuit for supplying power to the heating coil 3b on the left side and the heating coil 3c on the back side is mounted on the substrate 7b. The substrates 7a and 7b are respectively disposed in a space in which the substrate stand 73a and the substrate cover 6a are vertically combined, and the substrate stand 73b and the substrate cover 6b are vertically combined, and the space serves as an air passage (F1). The substrate covers 6a and 6b have a structure that covers at least the upper surfaces of the charged portions of the substrates 7a and 7b.

  FIG. 7 is a layout of the substrate and the fan device in the substrate cover taken along line DD shown in FIG. As shown in FIG. 7, a heat sink 8a of the substrate 7a and a heat sink 8b of the substrate 7b are arranged downstream of the discharge port 95 of the casing 90a of the fan device 9. The heat sinks 8 a and 8 b are radiators that absorb heat from the high heat generating element 72, which is an electronic component having high heat generation, and radiate heat to the air flowing in through the fan device 9. Each of the heat sinks 8a and 8b has a fin (not shown) having a predetermined surface area, and is provided on the substrates 7a and 7b. The outlet 95 of the fan device 9 is divided into two portions facing the heat sinks 8a and 8b, and a predetermined amount of air is guided to the heat sinks 8a and 8b with the driving of the motor 92. Since the high heat generating elements 72 constituting the inverter circuit are installed on the heat sinks 8a and 8b, high cooling performance can be obtained by arranging them on the most upstream side close to the fan device 9.

  FIG. 8 is a perspective view of a heat sink for cooling the high heat generating element 72 (72a, 72b, 72x) shown in FIG. 7, and is seen through the board covers 6a, 6b from the rear left of the main body. In this embodiment, ribs 60b extending downward (substrate side) are provided on the upper wall surfaces of the substrate covers 6a and 6b, respectively, and the ribs 60b and the outer walls of the substrate covers 6a and 6b form ventilation ducts 65a and 65b. .

  The heat sinks 8 a and 8 b are installed on the upstream side near the fan device 9. That is, the heat sinks 8a and 8b are arranged so that the high heat generating element 72 having the largest heat generation is cooled first by the air flowing through the discharge port 95. In this way, by disposing the heat sinks 8a and 8b near the discharge port 95 and concentrating the flow by the ribs 60b, the high heat generating element 72 can be effectively cooled. The ribs provided on the board covers 6a and 6b may be appropriately provided in consideration of the air distribution to the other electronic components 71 and the like. Also, the height of the ribs may be appropriately determined according to the air distribution condition, and may be provided not on the inside of the substrate cover but on the upper wall surface side of the heating coil side to serve as a coil cooling air path. Instead of the rib shape, a configuration may be adopted in which the upper wall surface of the substrate cover is provided with irregularities according to the external shape of the component.

  This embodiment shows an example in which the half bridge circuit of the current resonance inverter shown in FIG. 9 is constituted by the number of the high heating elements 72 shown in FIG. Here, FIG. 9A is a circuit diagram for the heating coil 3b on the left side and the heating coil 3c on the back side, and FIG. 9B is a circuit diagram for the heating coil 3a on the right side. As a circuit generally used in an induction heating cooker, there is a half bridge circuit of a current resonance inverter. For example, as shown in FIG. 9B, two half IGBTs (Insulated Gate Bipolar Transistor) 72a and DB (Diode Bridge) 72x are used. Be composed. Further, as shown in FIG. 9A, the present embodiment has a configuration in which the DB of the inverter that supplies power to the heating coils 3b and 3c is shared. The sharing of the DB is configured so as to be optimal on one substrate 7b, and further, as shown in FIG. 8, the high heat generating elements 72 are arranged in a layout arranged in the front-rear direction of the main body, and are used as cooling air passages. .

  FIG. 10 is a top view showing the flow in the main body 1 from the fan device 9 to the exhaust opening H2 through the top plate 2. As shown in FIG. 10, the air discharged from the fan device 9 flows from the rear to the front through the ventilation ducts 65a and 65b near the left and right centers of the main body 1 (see FIG. 7). The air that has passed through the ventilation duct 65a is bent to the right side of the main body, cools the electronic components 71 (not shown) on the substrate 7a in the substrate cover 6a, and is supplied to the heating coil 3a downstream thereof. .

  The air that has passed through the ventilation duct 65b has its main flow bent to the left side of the main body, cools the electronic components 71 (not shown) on the board 7b in the board cover 6b, and is supplied to the heating coil 3b downstream thereof. . That is, since the cooling air of the fan device 9 is guided so that the main flow branches and flows to the left and right sides of the main body in the substrate covers 6a and 6b, the cooling air is easily guided efficiently to the downstream exhaust opening H2 without intersecting. Has become. Further, in this configuration, the cooling air path is composed of two layers in the substrate covers 6a and 6b (F1) and below the top plate 2 (F2), so that the main flow from the fan device 9 collides with the wall surface. The number of parts that change the flow direction is reduced, and a structure with reduced ventilation resistance can be realized.

  FIG. 11 is a side sectional view when the heating coil 3a is installed, and FIG. 12 is a perspective exploded view of the heating coil 3a. As shown in FIGS. 11 and 12, the heating coil 3a is mounted on a coil base 31 in which a rod-shaped ferrite 33 made of a magnetic material is radially incorporated. It is held by three support portions 32 via support grooves 31a on the outer periphery. The ferrite 33 is arranged so that the magnetic flux around the heating coil 3a, which is generated by the high-frequency current supplied from the inverter board 7a to the heating coil 3a, is directed to the cooking pot. Note that the ferrite 33 may be formed in a fan shape instead of a rectangular shape with respect to the heating coil. In the case of a fan shape, the lower surface of the heating coil can be easily covered with ferrite, and leakage of magnetic flux can be reduced.

  The support portion 32 is installed on the substrate covers 6a and 6b and the casing 90a (see FIG. 2), and supports the coil base 31 from below. In this embodiment, the support portion 32 is formed of a spring inserted into the support groove 31a, and presses the coil base 31 against the top plate 2 while aligning the heating coil 3a. Are close to each other.

  In the vicinity of the center of the coil base 31, a contact-type temperature sensor 34 such as a thermistor that indirectly detects the temperature of the cooking pot from the contact temperature with the top plate 2 via a sensor base 34a. The sensor base 34a has a shaft (not shown) that penetrates a support hole 31b at the center of the coil base 31, and the temperature sensor 34 on the sensor base 34a is topped by a spring 34b provided on the shaft. It is configured to be pressed against the plate 2. The smaller the gap between the heating coil 3a and the top plate 2 is, the better the electrical connection with the cooking pot is. Therefore, the smaller the gap is, the more efficient heating can be performed. The heating coil 3a of this embodiment has a configuration in which a litz wire formed by twisting a plurality of strands is spirally wound, and the heating coil 3a is formed of an outer litz wire 30a and an inner litz wire 30b. It has a split configuration. The above configuration is an effective arrangement for uniformly heating the cooking pot, and if a temperature sensor is separately arranged between the outer litz wire 30a and the inner litz wire 30b, the temperature of the bottom of the cooking pot can be reduced. The sensor can be arranged at a position close to the highest temperature portion, and the temperature of the cooking pot can be appropriately controlled. Here, a non-contact sensor such as an infrared sensor may be used as the temperature sensor instead of the thermistor.

(Modification)
FIG. 13 is a modification of the side sectional view of the induction heating cooker shown in FIG. 3, in which the fan device 9 is constituted by an axial fan. As in FIG. 3, the fan device 9 has a configuration in which the rotating shaft 92a is in the up-down direction of the main body 1, and the air flowing in from the intake opening H1 is sucked in through the chamber portion F0. In the axial fan, since the suction direction and the discharge direction of the air are in the direction of the rotating shaft 92a, a casing 90a with which the discharged air collides is provided above the fan device 9, and the flow direction is changed by 90 degrees to cool the substrate 7a. Supply. With this configuration, since the motor 92 shown in FIG. 3 is not disposed so as to be exposed near the top plate 2, the failure of the fan device 9 due to liquid intrusion can be reduced. Alternatively, the same applies to a configuration in which the motor of the centrifugal fan of the first embodiment is embedded in the impeller and installed inside the upper casing 90a.

(Heating operation and air flow inside the board case)
The cooking pot is placed on the pot placing portion 21 (corresponding to the left heating coil 3a) of the top plate 2, and the heating process is started when the user operates the operation portion 22 (see FIG. 1). . The operation unit 22 is a touch key, and can be operated by touching a key printed on the top plate 2.
A high-frequency current is supplied from the inverter circuit shown in FIG. 9B to the heating coil 3a located below the cooking pot in response to a command from a control device (not shown), and the cooking pot is induction-heated. You. When the cooking pot is induction-heated by the heating coil 3a, in addition to the heating coil 3a, the high heating element 72 and the electronic component 71 constituting the inverter circuit also generate heat.

  At the start of the heating process, the fan device 9 is driven according to a command from a control device (not shown). When the fan device 9 is driven, a negative pressure is generated at the inlet of the impeller 91, and the air flowing from the intake opening H1 via the chamber portion F0 is taken into the fan device 9. The air discharged from the fan device 9 is diverted to the ventilation ducts 65a and 65b in the substrate covers 6a and 6b, and absorbs heat from the heat sink 8a on the substrate 7a. The high heat generating element 72 (72a, 72x) is cooled by heat radiation through the heat sink 8a, and the other electronic components 71 mounted on the substrate 7a are also cooled by heat exchange with air. The air that has cooled the substrate 7a flows from the discharge portion 60a above the substrate cover 6a toward the heating coil 3a, cools the heating coil 3a, and is discharged through the exhaust opening H2. The air that has passed through the ventilation duct 65b also flows through the inside of the substrate cover 6b, and similarly flows and is exhausted from the exhaust opening H2.

<Effect>
According to the present embodiment, it is possible to provide an induction heating cooker that suppresses water intrusion into the inside of the main body, has less trouble, and has high safety. Further, the distance between the exhaust opening H2 and the substrates 7a and 7b is increased by the casing 90a of the fan device 9 provided near the exhaust opening H2, and the liquid penetrating from the exhaust opening H2 reaches the charged portions of the substrates 7a and 7b. It has become difficult.

  Also, even if the top plate is cracked or broken and liquid invades from the cracks or the like, the liquid does not come into contact with the charged portion and safety can be maintained. In addition, by arranging the substrates 7a and 7b and the fan device 9 in a planar shape, the fan device can be operated efficiently and parts can be cooled, so that a comfortable use environment where cooking can be performed with low noise can be maintained, and cooking with high heat can be performed. An induction heating cooker that can be provided.

  The second embodiment is different from the first embodiment in the configurations of the substrate covers 6a and 6b, the heating coil, and the top plate 2, but is otherwise the same as the first embodiment. Therefore, only the different parts will be described, and the description of the parts overlapping with the first embodiment will be omitted.

  FIG. 14 is an exploded perspective view of the induction heating cooker according to the second embodiment, and shows the components of the substrate covers 6a, 6b and the heating coils 3a, 3b, 3c. FIG. 15 is a side sectional view of the heating coil of FIG. As shown in FIG. 14, the substrate covers 6a and 6b according to the present embodiment are provided with an opening 63 and a discharge unit 60a. The openings provided above the substrate covers 6a and 6b have a larger opening area than the discharge unit 60a (see FIG. 2) of the first embodiment. The larger the opening area, the lower the average wind speed and the lower the ventilation resistance when passing through the discharge section 60a.

  That is, by providing the discharge portion 60a having a large opening area shown in FIG. 14, the entire ventilation resistance from the intake opening H1 to the exhaust opening H2 is reduced. Therefore, it is possible to efficiently blow air from the fan device 9 with a small fan power. Further, as shown in FIG. 15, since the cooling air can be supplied from below the heating coil 3a, the heating coil can be efficiently cooled with a low pressure loss.

  On the other hand, when the liquid invades due to a crack in the top plate 2 or the like, the electronic components 71 of the substrates 7a and 7b exposed from the ejection portions 60a provided on the substrate covers 6a and 6b are protected. In the coil 3a, a waterproof plate 35 larger than the outer shape of the heating coil 3a is installed in a gap between the coil 3a and the top plate 2. The waterproof plate 35 is not limited as long as it does not affect the induction heating of the cooking pot. For example, a mica plate is inexpensive and easy to mold, so that manufacture is easy. That is, the discharge portions 60a of the substrate covers 6a, 6b provided below the heating coils 3a, 3b, 3c of the present embodiment are covered with the waterproof plate 35. For this reason, the liquid entering through the top plate 2 above the heating coils 3a, 3b, 3c drops onto the substrate covers 6a, 6b on the outer peripheral side of the heating coils 3a, 3b, 3c without entering the discharge part 60a. Thus, the charged portions of the substrates 7a and 7b are protected.

  FIG. 16 shows the top plate 2 of the induction heating cooker according to the second embodiment, as viewed from the heating coil side. The top plate 2 of this embodiment has a configuration in which a reinforcing plate 20 is provided on the back surface, and is attached to a portion excluding the heating coils 3a, 3b, 3c and the display unit P1. The reinforcing plate 20 is used for protecting the electronic component 71 when liquid invades due to misuse when the glass is cracked. Therefore, even if the opening 63 as shown in FIG. 14 is provided in the substrate cover 6b, the liquid does not enter the opening 63 and the electronic component 71 on the substrate 7b does not get wet.

  In this way, by covering the substrate covers 6a and 6b with the reinforcing plate 20, the safety against cracking of the top plate 2 and the like can be further improved. In addition, the opening 63 of the substrate cover 6b below the reinforcing plate 20 is arbitrarily arranged, so that the efficiency of the ventilation path with reduced ventilation resistance can be improved. Furthermore, since the motor 92 of the fan device 9 can be protected, the motor is less likely to touch the liquid.

  FIG. 17 shows a modification of the top plate 2 shown in FIG. 16, in which the area of the reinforcing plate 20 provided on the lower surface of the top plate 2 is further enlarged. In this embodiment, the liquid intrusion path from the cracks in the top plate 2 is limited to an area excluding the reinforcing plate 20, three waterproof plates 35, and the teaching portion P1 from the top plate 2. Therefore, if the reinforcing plate 20 is widely arranged so as to cover the top plate 2 so as to surround the heating coils 3a, 3b, and 3c, it is possible to further reduce the trouble caused by the liquid that has entered due to the crack in the top plate 2.

  The reinforcing plate 20 is made of a metal such as an iron plate, and needs to be separated from the heating coils 3a, 3b, and 3c so as not to be subjected to induction heating. However, the waterproof plate 35 is enlarged, and the gap between the reinforcing plate 20 and the waterproof plate 35 is increased. May be reduced. Further, the waterproof plate 35 may cover most or all of the top plate 2.

  According to the present embodiment, it is easy to protect the charged portions of the substrates 7a and 7b against cracks and cracks in the top plate 2, and it is possible to perform safe and highly reliable heating cooking.

DESCRIPTION OF SYMBOLS 1 Main body 2 Top plate 20 Reinforcement plate 22 Operation part 3a, 3b, 3c Heating coil 35 Waterproof plate 6a, 6b Board cover 7a, 7b board 71 Electronic component 72 (72a, 72b, 73b, 73x) High heat generating element 73a, 73b board Table 8a, 8b Heat sink 9 Fan device 90a, 90b Casing 91 Impeller 92 Motor F0 Chamber H1 Intake opening H2 Exhaust opening P1 Display

Claims (3)

  Body and
  A top plate installed on the upper surface of the main body,
  A plurality of heating coils provided below the top plate,
  A substrate on which electronic components such as an inverter for supplying high-frequency power to the heating coil are mounted,
  A waterproof plate provided in a gap between the top plate and the heating coil,
  A fan device for cooling the substrate;
  In an induction heating cooker having a grill storage built in the main body,
  Arranging the substrate between the plurality of heating coils and the grill storage, a substrate cover that covers the substrate is provided between the plurality of heating coils and the substrate,
  The substrate cover includes a discharge unit that supplies air that has cooled the substrate to the heating coil,
  The induction heating cooker, wherein the waterproof plate is provided so as to cover an opening of the discharge unit from above.   2. The fan device according to claim 1, wherein the fan device is disposed near an exhaust opening of the main body, a rotation axis of the fan device is in a vertical direction of the main body, and a suction port of the fan device is provided below. Induction heating cooker.   An intake opening is provided on the back side of the main body,
  The induction heating cooker according to claim 2, wherein at least a part of the intake opening is provided below a suction port of the fan device.

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