JP2017041334A - Induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction heating cooker which has high water resistance and which is not likely to break down at the time of water immersion.SOLUTION: An induction heating cooker comprises: a body 1; a top plate 2 installed on a top face of the body; a plurality of heating coils 3a, 3b provided below the top plate; multiple substrates/a single substrate 7a, 7b on which an electronic component 71 such as an inverter for supplying high frequency power to the heating coils is mounted; a fan unit 9 for cooling the substrate; and a grill chamber 5 built in the body, in which the multiple substrates/single substrate are/is arranged between the plurality of heating coils and the grill chamber in such a manner that planes/a plane of the multiple substrates/single substrate are/is included in a height of an outflowing part of the fan unit. The induction heating cooker further comprises substrate covers 6a, 6b provided between the plurality of heating coils and the multiple substrates/single substrate, for covering the electronic components.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an induction heating cooker.

  An induction heating cooker is a device that performs cooking by using Joule heating due to eddy currents generated at the bottom of a pan when magnetic lines generated by passing a high-frequency current through a heating coil pass through a metal pan. Since heat is generated not only from the pan but also from the heating coil and the substrate that controls the heating coil during heating, air cooling is performed using a fan device.

  In addition, the induction heating cooker arranged in the system kitchen is mainly composed of cooking such as grilled fish in a heating chamber (grill chamber) equipped with a heat source such as an electric heater, in addition to induction heating of the cooking pan on the top plate. It is.

  In a conventional induction heating cooker, main components to be cooled are a plurality of heating coils and a substrate, and the heating coil is housed in the vicinity of the top plate above the main body and the substrate is stored in an extra space on the side of the grill part. The configuration is general (Patent Document 1).

  The intake and exhaust ports of the main body arranged in the system kitchen have a large intake / exhaust path 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 boiling or boiling in a cooking pan during heating or water vapor in the pan hardly flows into the main body.

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

  Alternatively, even if the top plate is accidentally heated when it is cracked or damaged, the liquid that has been spilled can be prevented from entering the live part of the board (exposed part of the circuit pattern). Have been taken.

  On the other hand, most of the system kitchen frames in Japan are stipulated in dimensions, so the maximum outer dimensions of induction heating cookers are also roughly determined, which is optimal in a limited space for cooling heating coils and substrates. It is necessary to construct an air path.

  In order to efficiently heat the cooking pan 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. In general, the optimum layout means that components are arranged with an ideal circuit pattern in which the distance between components is narrow (high integration) and is not easily influenced by other electronic components such as a power supply (low noise). Therefore, the circuit board is configured such that the control board is configured on one side like the induction heating cooker described in Patent Document 2 and there is no wiring (jumper wire etc.) between the boards or between the electronic parts on the board. A circuit that is effective in improving efficiency and that has 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 such as Patent Document 1 has a circuit configuration in which a plurality of substrates are divided and stacked on the side of the grill cabinet and have a plurality of wirings connecting the substrates ( (There is a limit to optimization), and 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 close to each other in the vicinity of 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 blowing performance of the fan device, resulting in a decrease in component cooling performance and an increase in fan noise.

  On the other hand, in the case of an induction heating cooker having a grill cabinet 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 in one plane between the grill cabinet and the top plate. The volume is insufficient. In a general system kitchen, the gap between the grill cabinet and the top plate is only about 60 mm, and the grill cabinet has a volume of about half or more of the main body width. For this reason, when it is going to store a board | substrate in a main body by arrange | positioning on a substantially identical surface, the clearance gap of the height direction from a grill warehouse to a heating coil will be about 20-30 mm, and a component mounting volume is conventionally (patent document 1). Also decreases. Here, a heat sink is mounted on the substrate to dissipate and dissipate electronic components that generate high heat, and a heat sink having a height of about 40 to 50 mm is used for the substrate stacked and stored on the side of the grill cabinet. 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. Therefore, if the heat sink volume is reduced, a large fan device with high pressure is required. In other words, it is impossible to simply store the substrates stacked on the side of the grill cabinet side by side under the heating coil.

  Further, when the substrate is disposed below the heating coil, the substrate is in a positional relationship closer to the top plate than in the conventional case. For this reason, compared with the state which laminated | stacked the board | substrate like patent document 1 on one side, possibility that a board | substrate and a liquid will contact by liquid penetration will become high. 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 remarkably close. Furthermore, there is a possibility of liquid intrusion over the entire top plate when the top plate is cracked or broken.

  In view of this, the present invention provides an induction heating cooker having a substrate layout on which a circuit pattern for driving with high efficiency is mounted and a liquid invasion prevention structure, with the substrate disposed below the heating coil so that electronic components can be optimally arranged. It is an issue to provide.

  In order to solve the above-mentioned problems, an induction heating cooker according to the present invention includes a main body, a top plate installed on the upper surface of the main body, a plurality of heating coils provided below the top plate, and the heating coil. In an induction heating cooker provided with a plurality of / single substrates mounted with electronic components such as inverters for supplying high frequency power, a fan device for cooling the substrates, and a grill box built in the main body, The plurality / single substrate is disposed between a heating coil and the grill cabinet, and the plane of the plurality / single substrate is disposed so as to be included in the height of the outflow portion of the fan device. A substrate cover that covers the electronic component is provided between the heating coil and the plural / single substrate.

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

  According to the present invention, it is possible to provide an induction heating cooker that suppresses water intrusion into the main body, has few failures, and is highly safe.

The perspective view of the induction heating cooking appliance of Example 1. Exploded view of the induction heating cooker shown in FIG. Side sectional view cut along line AA shown in FIG. 1 is an exploded perspective view of the fan device shown in FIG. Front sectional view cut along line BB shown in FIG. Front sectional view cut along line CC shown in FIG. The layout of the board and fan device in the board cover cut along the line DD shown in FIG. The perspective view of the heat sink which cools the high heat-emitting component shown in FIG. FIG. 10 is a circuit diagram of a current resonance inverter composed of the high heat generation component of FIG. 9. Top view showing the flow of air in the induction heating cooker Side sectional view when the heating coil of FIG. 1 is installed 1 is an exploded perspective view of the heating coil of FIG. The modification of side sectional drawing of the induction heating cooking appliance shown in FIG. The exploded perspective view of the induction heating cooking appliance of Example 2 Side sectional view of the heating coil of FIG. Top plate of induction heating cooker of embodiment 2 Top plate of Example 3

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

<Configuration of induction heating cooker>
FIG. 1 is a perspective view of the induction heating cooker Z of Example 1, 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 IH (Induction Heating) cooking heater provided with a grill 5 for heating an object to be cooked with an electric heater or the like.

  The induction heating cooker Z is an apparatus that generates an eddy current at the bottom of a cooking pot (not shown) made of metal and generates the cooking pot itself by Joule heat generated by the eddy current. The aforementioned eddy current is generated by changing the magnetic flux with time by supplying a high-frequency current of about 20 kHz to 40 kHz to the heating coils 3a, 3b, and 3c. The induction heating cooker Z mainly covers the main body 1, the top plate 2, the heating coils 3a, 3b, and 3c, the substrates 7a and 7b placed on the substrate bases 73a and 73b, and the substrates 7a and 7b. Board covers 6a and 6b and a fan device 9 are provided. The main body 1 is a housing having an outer shell corresponding to a space (predetermined left-right width, front-rear width, height) in which the induction heating cooker Z is installed, and has a box-like shape (concave shape) with an open top. Yes. The main body 1 is provided with a lower left grill box 5, and substrates 7 a and 7 b placed on the board bases 73 a and 73 b above the partition plate 1 b covering the grill box 5, and a lower casing constituting the fan device 9. 90b and the impeller 91 are arranged in a planar shape, and the discharge port 95 which is the outflow portion of the fan device 9 is arranged at a height including the surfaces of the substrates 7a and 7b.

  The substrates 7a and 7b are covered with substrate covers 6a and 6b, respectively, and an upper casing 90a that constitutes the fan device 9 is arranged alongside the substrate covers 6a and 6b, and the heating coils 3a, 3b, 3c, the display part P1, etc. are installed, and the top plate 2 is further installed so as to cover from above. Here, the electronic component 71 on the boards 7a and 7b is an integrated circuit, an inverter circuit, a capacitor, a resistor, or the like used for supplying a high-frequency current to the heating coils 3a and 3b or driving 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, and 3c are installed below the top plate 2, and a temperature sensor 34 that detects the temperature of the pan bottom is installed near the center. The heating coils 3a, 3b, 3c are arranged on the downstream side of the fan device 9, and after the cooling air blown from the fan device 9 cools the substrates 7a7b in the substrate covers 6a, 6b, the front corners of the main body The heating coils 3a, 3b, 3c are cooled via the discharge part 60a. The heating coils 3 a, 3 b, and 3 c are coils through which a high-frequency current flows by driving an inverter circuit described later, and are placed on the coil base 31. In this embodiment, the heating coils 3a, 3b, and 3c are provided one by one on the right, left, and center back 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. Thereby, 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.

  The grill compartment 5 on the left side of the front face of the main body 1 is provided with an insertion port (not shown) for sliding the article back and forth to install an object to be cooked (not shown). An operation panel P <b> 2 for mainly adjusting the heating condition in the grill 5 is provided on the front right side of the main body 1. The top plate 2 is composed of a plate glass (not shown) on which the cooking pan is placed and a frame portion (not shown) that holds four sides of the plate glass, and is installed from above the main body 1. . The top plate 2 includes a three-necked pan mounting unit 21 corresponding to the installation positions of the three heating coils 3a, 3b, and 3c, an operation unit 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 from the fan device 9, and is provided at the rear (right side / left side) of the top plate 2. FIG. 3 is a sectional side view taken along line AA shown in FIG.

  An intake opening H <b> 1 for taking in air from the outside by driving the fan device 9 is provided on the back side of the main body 1. Air blown out from the fan device 9 into the main body 1 is discharged from an exhaust opening H2 provided behind the top plate 2.

  In addition to the rear of the main body 1, for example, if an intake opening is provided on the lower front side, 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 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 arranged substantially in a plane with the substrates 7a and 7b and provided on the sides 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 with the impeller 91 sandwiched therebetween, and a motor 92 that penetrates the casing 90 a and is connected to the impeller 91. That is, the impeller 91 is housed in a space surrounded by the casing 90a provided with the motor 92 and the casing 90b provided with the air inlet 9a, and the rotating shaft 92a of the motor 92 is prevented from contacting the casings 90a and 90b. Is supported rotatably. 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 in two directions from the side discharge ports 95. The intake port 9a of the casing 90b has a bell mouth shape (not shown). That is, the fan device 9 is disposed 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 is divided in two directions from the discharge port 95, and the heat sink 8a of the substrates 7a and 7b. , 8b (see FIG. 1) is supplied with cooling air.

  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 cabinet 5. The chamber F0 provided between the intake opening H1 and the fan device 9 relaxes the wind speed distribution of the air flowing in from the intake opening H1, and supplies a less turbulent airflow along the bell mouth of the intake opening 9a.

  Therefore, the 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 working efficiently. Therefore, the fan device 9 can be rotationally driven with low noise and a large air volume, and becomes an induction heating cooker with low operation sound. That is, when the fan device 9 is incorporated in the induction heating cooker Z, a predetermined pressure increase of the impeller 91 can be secured, so that it is not necessary to increase the number of rotations more than necessary, and operation is possible with low noise.

  Further, the lower casing 90b of the fan device 9 protrudes downward from the partition plate 1b (see FIG. 1) on which the board base 73a is placed, and the impeller having a large diameter and a large blade thickness can be easily accommodated. It has become.

The fan device 9 in induction heating cooking has a sufficient air flow resistance (for example, 100 to 200 Pa) in the main body 1, and the air flow necessary for cooling at a low speed rotation (the air flow characteristic of sufficient pressure-air flow). (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 the noise can be easily reduced while suppressing operation noise during use. Become.

  The air blown from the fan device 9 flows on the substrate 7a installed in the gap between the substrate stand 73a and the substrate cover 6a (F1), and the substrate cover toward the heating coil 3a installed on the substrate cover 6a downstream thereof. It flows through the gap between 6a and the top plate 2 (F2). In this embodiment, a discharge portion 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 surface is not visible even when viewed from above. This is to prevent the liquid from entering the substrate cover from the opening of the discharge section 60a even if the liquid enters the crack from the top plate.

  As shown in FIG. 3, since 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 base 73a, air is blown obliquely upward toward the substrate cover 6a. The In this configuration, the 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 is suppressed. Since the heating coil 3a during induction heating cooking rises to a temperature close to 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 causing the main flow to drift to the substrate cover 6a side, thermal deformation due to radiant heat is suppressed.

  In the present embodiment in which the substrate 7a (7b) is provided on the grill cabinet 5, the distance between the heating coils 3a (3b, 3c) and the substrate 7a (7b) is closer than in the conventional configuration in which the substrate is provided on the side of the grill cabinet. Therefore, although it is easily affected by the temperature rise of the heating coil, as in the present configuration, the main flow of the fan device 9 is inclined to the substrate cover 6a (6b), whereby 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 heating 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 in which a plurality of small-diameter holes are provided in a metal plate, so that liquid (not shown) that flows when spillage occurs on the top plate is difficult to enter. Yes. 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 so as to receive and buffer the dropped liquid droplets on a wide surface so that it does not flow into the fan device 9 side. Yes. A grid-like partition 94 a is provided between the water receiving portion 94 and the motor 92 to suppress liquid intrusion into the main body 1.

  Further, in the configuration of the present embodiment, the fan device 9 is arranged in the vicinity of the exhaust opening H2, so that the distance from the right exhaust opening H2 to the substrate 7a can be increased, and liquid enters the charging portion of the substrate. It has a difficult structure. Therefore, the possibility of liquid intrusion of the substrate 7a with respect to the exhaust opening H2 can be extremely reduced, and this embodiment has a highly safe structure in which failure is unlikely to occur. 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 droplets that have passed through the exhaust cover 25 fall to the rear of the grill box 5. Therefore, it is difficult to enter the substrate cover 6b side.

  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 cabinet 5 is a space for arranging cooked food such as fish grill, for example, and an electric heater (upper heater 51 and lower heater 52) as a heat source and a grill on which fish and the like are placed. 54 and a tray 53 disposed below the grill net 54. As described above, the heating chamber 50 is arranged in the left region in the main body 1 in a plan view, and the inner tray 53 and the like can slide relative to the main body 1 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, water vapor, or a combination thereof. Further, a temperature controller may be provided and oven heating may be performed. In FIG. 1, the induction heating cooking appliance Z provided with the grill 5 with 1/2 or more of main body width was shown.

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

  FIG. 7 is a layout of the board and the fan device in the board cover cut along the line DD shown in FIG. As shown in FIG. 7, the heat sink 8a of the substrate 7a and the heat sink 8b of the substrate 7b are respectively arranged on the downstream side of the discharge port 95 of the casing 90a of the fan device 9. The heat sinks 8 a and 8 b are heat radiators that absorb heat from the high heat generating element 72, which is an electronic component with high heat generation, and dissipate heat to the air flowing in through the fan device 9. Each of the heat sinks 8a and 8b has fins (not shown) having a predetermined surface area, and is installed on the substrates 7a and 7b. The discharge port 95 of the fan device 9 is divided into two locations facing the heat sinks 8a and 8b, and a predetermined flow rate of air is guided to the heat sinks 8a and 8b as the motor 92 is driven. Since the heat generating elements 72 constituting the inverter circuit are installed in the heat sinks 8a and 8b, high cooling performance can be obtained by arranging them on the most upstream side near 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 left rear side of the main body. In the present embodiment, ribs 60b extending downward (board side) are provided on the upper wall surfaces of the substrate covers 6a and 6b, respectively, and ventilation ducts 65a and 65b are constituted by the ribs 60b and the outer walls of the substrate covers 6a and 6b. .

  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 amount is cooled first by the air flowing in through the discharge port 95. As described above, the heat generating elements 72 can be effectively cooled by disposing the heat sinks 8a and 8b in the vicinity of the discharge port 95 and concentrating the flow by the rib 60b. The ribs provided on the board covers 6a and 6b may be appropriately provided in consideration of the air distribution to other electronic components 71. Further, the height of the rib may be determined as appropriate according to the air distribution situation, and even if it is not inside the substrate cover, it may be provided on the upper wall surface side of the heating coil and may be used as a coil cooling air passage. Moreover, the structure which provided the unevenness | corrugation in the upper wall surface of the board | substrate cover according to the external shape of components instead of a rib shape may be sufficient.

  In the present embodiment, an example is shown in which the half-bridge circuit of the current resonance inverter shown in FIG. 9 is configured by the number of high heat generating elements 72 shown in FIG. 9A is a circuit diagram for the left side heating coil 3b and the back side heating coil 3c, and FIG. 9B is a circuit diagram for the right side heating coil 3a. 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 IGBTs (Insulated Gate Bipolar Transistor) 72a and DB (Diode Bridge) 72x are used. Composed. Moreover, as shown to Fig.9 (a), it has the structure which shared DB of the inverter which supplies electric power to the heating coils 3b and 3c in a present Example. The DB is shared so as to be optimal on a single substrate 7b, and as shown in FIG. 8, the high heat generating elements 72 are laid out in the longitudinal direction of the main body and used as a cooling air passage. .

  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. FIG. As shown in FIG. 10, the air discharged from the fan device 9 flows from the rear toward the front through the ventilation ducts 65a and 65b near the center of the left and right of the main body 1 (see FIG. 7). The air passing through the ventilation duct 65a is bent to the right side of the main body to cool the electronic component 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 is bent to the left side of the main body to cool the electronic component 71 (not shown) on the substrate 7b in the substrate cover 6b, and is supplied to the heating coil 3b downstream thereof. . That is, the cooling air of the fan device 9 is guided so that the main flow branches and flows left and right in the substrate covers 6a and 6b, and therefore, it is easily guided efficiently to the downstream exhaust opening H2 without crossing the flows. It has become. Further, in this configuration, the cooling air passage 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 draft 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 rod-like ferrites 33, which are magnetic bodies, are radially incorporated. For example, an elastic spring is used to form the coil base 31. It is hold | maintained by the three support parts 32 via the outer periphery support groove | channel 31a. The ferrite 33 is arranged so that the magnetic flux around the heating coil 3a generated by the high-frequency current supplied from the inverter board 7a to the heating coil 3a is directed to the cooking pot. The ferrite 33 may be fan-shaped instead of rectangular with respect to the heating coil. If it is fan-shaped, it becomes easy to cover the lower surface of the heating coil 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 the present embodiment, the support portion 32 is constituted by a spring inserted into the support groove 31a, and the coil base 31 is pressed against the top plate 2 while positioning the heating coil 3a, and the heating coil 3a and the top plate 2 are pressed. Are in close proximity.

  Near the center of the coil base 31, a contact-type temperature sensor 34 such as a thermistor for detecting the temperature of the cooking pot indirectly from the contact temperature with the top plate 2 is arranged via a sensor base 34a. The sensor base 34a is provided with a shaft portion (not shown) penetrating the support hole 31b in 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 portion. It is configured to press against the plate 2. The smaller the gap between the heating coil 3a and the top plate 2, the better the electrical coupling with the cooking pan. Therefore, the smaller the gap, the more efficient the heating. The heating coil 3a of the present embodiment has a configuration in which a litz wire obtained by twisting a plurality of strands is spirally wound, and the heating coil 3a is composed of an outer litz wire 30a and an inner litz wire 30b, and is doubled in the radial direction. It has a divided structure. The configuration as described above is an effective arrangement for uniformly heating the cooking pan. If a temperature sensor is separately provided between the outer litz wire 30a and the inner litz wire 30b, A sensor can be arranged at a position close to the maximum temperature part, and the cooking pot temperature can be appropriately controlled. Here, the temperature sensor may be a non-contact sensor such as an infrared sensor instead of the thermistor.

(Modification)
FIG. 13 is a modified example of a side cross-sectional view of the induction heating cooker shown in FIG. 3, and 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 vertical direction of the main body 1 and the air flowing in from the intake opening H1 is sucked through the chamber portion F0. In the axial fan, since the air suction direction and the discharge direction are in the direction of the rotation shaft 92a, a casing 90a that collides with the air discharged above the fan device 9 is provided, and the flow direction is changed by 90 degrees to Supply. With this configuration, since the motor 92 shown in FIG. 3 is not exposed and disposed in the vicinity of the top plate 2, failure of the fan device 9 due to liquid intrusion can be reduced. Or it is the same even if it is the structure which embedded the motor of the centrifugal fan of 1st Example in the impeller, and was installed inside the upper casing 90a.

(Heating operation and air flow in the substrate case)
The cooking pot is placed on the pan placing portion 21 (corresponding to the left heating coil 3a) of the top plate 2, and the operation is started by the user operating 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 to the heating coil 3a located below the cooking pan from the inverter circuit shown in FIG. 9B in response to a command from a control device (not shown), and the cooking pan is induction-heated. The When the cooking pan is induction-heated by the heating coil 3a, the high heating element 72 and the electronic component 71 constituting the inverter circuit generate heat in addition to the heating coil 3a.

  With the start of the heat treatment, the fan device 9 is driven in response 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 air flowing from the intake opening H1 through 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 dissipation through the heat sink 8a, and the other electronic components 71 mounted on the board 7a are also cooled by heat exchange with air. The air that has cooled the substrate 7a flows from the discharge part 60a above the substrate cover 6a toward the heating coil 3a, cools the heating coil 3a, and is then discharged through the exhaust opening H2. The air that has passed through the ventilation duct 65b also flows through the substrate cover 6b, and flows in the same manner 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 main body, has few failures, and has high safety. Further, the casing 90a of the fan device 9 provided in the vicinity of the exhaust opening H2 increases the distance between the exhaust opening H2 and the substrates 7a and 7b, and the liquid that has entered from the exhaust opening H2 reaches the charging portions of the substrates 7a and 7b. It has become difficult.

  In addition, even if the top plate is cracked or broken and the liquid enters from the crack or the like, the liquid does not come into contact with the charged part, and safety can be maintained. In addition, since the boards 7a and 7b and the fan device 9 are arranged in a flat shape, the fan device can be operated efficiently and the parts can be cooled, thus maintaining a comfortable use environment where cooking can be done with low noise and cooking with high thermal power. An induction heating cooker 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, the different part will be described, and the description of the same part as the first embodiment will be omitted.

  FIG. 14 is an exploded perspective view of the induction heating cooker according to the second embodiment, showing the component structure of the substrate covers 6a and 6b and the heating coils 3a, 3b and 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 shown in the present embodiment are provided with an opening 63 and a discharge part 60a. The opening provided above the substrate covers 6a and 6b has a larger opening area than the discharge part 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 part 60a.

  That is, by providing the discharge portion 60a having a large opening area shown in FIG. 14, the overall ventilation resistance from the intake opening H1 to the exhaust opening H2 is reduced. For this reason, it is possible to efficiently blow air from the fan device 9 with less 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 low pressure loss.

  On the other hand, when liquid enters due to cracks or the like of the top plate 2, the heating of this embodiment is performed to protect the electronic components 71 of the substrates 7 a and 7 b exposed from the discharge portions 60 a provided on the substrate covers 6 a and 6 b. The coil 3 a is provided with a waterproof plate 35 larger than the outer shape of the heating coil 3 a in the gap with the top plate 2. The waterproof plate 35 is not limited as long as it is a material that does not affect induction heating of the cooking pot. For example, a mica plate is easy to manufacture because it is inexpensive and easy to mold. That is, the discharge part 60a of the board | substrate covers 6a and 6b provided under the heating coils 3a, 3b, and 3c of a present Example is covered with the waterproof board 35. FIG. For this reason, the liquid that enters through the top plate 2 above the heating coils 3a, 3b, and 3c does not enter the discharge section 60a and drops on the substrate covers 6a and 6b on the outer peripheral side of the heating coils 3a, 3b, and 3c. The charged parts of the boards 7a and 7b are protected.

  Moreover, FIG. 16 is the top plate 2 of the induction heating cooking appliance which concerns on 2nd Example, and is the figure seen 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, and 3c and the display portion P1. The reinforcing plate 20 is used to protect the electronic component 71 when liquid enters due to misuse when a crack occurs in the glass. 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.

  Thus, by covering the substrate covers 6a and 6b with the reinforcing plate 20, safety against cracks of the top plate 2 can be further improved. Further, the opening 63 of the substrate cover 6b below the reinforcing plate 20 can be arbitrarily arranged to increase the efficiency of the air blowing path with reduced ventilation resistance. Furthermore, since the motor 92 of the fan device 9 can be protected, the motor is less likely to touch the liquid.

  FIG. 17 is 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 the present embodiment, the liquid intrusion path from the crack of the top plate 2 is limited to the area portion excluding the reinforcing plate 20, the 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 surround the heating coils 3a, 3b, and 3c so as to cover the top plate 2, failure due to liquid that has entered due to cracks in the top plate 2 can be reduced.

  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 induction-heated. 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 the entire surface of the top plate 2.

  According to the present embodiment, it becomes easy to protect the charging parts of the substrates 7a and 7b against cracks and cracks in the top plate 2, and further safe and highly reliable cooking can be performed.

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

Claims (4)

The body,
A top plate installed on the upper surface of the main body;
A plurality of heating coils provided below the top plate;
A plurality of / single substrates on which electronic components such as an inverter for supplying high-frequency power to the heating coil are mounted;
A fan device for cooling the substrate;
In an induction heating cooker provided with a grill house built in the main body,
The plurality / single substrate is arranged between the plurality of heating coils and the grill cabinet, and the plane of the plurality / single substrate is arranged to be included in the height of the outflow portion of the fan device, An induction heating cooker, wherein a substrate cover that covers the electronic component is provided between the plurality of heating coils and the plurality / single substrate.   The induction heating cooker according to claim 1, wherein a reinforcing plate is provided under the top plate so as to avoid a heating coil.   The induction heating cooker according to claim 1, wherein a waterproof plate is provided in a gap between the top plate and the heating coil.   The fan device is disposed in the vicinity of an exhaust opening of the main body, the rotation shaft of the fan device is in the vertical direction of the main body, and the suction port of the fan device is provided below. The induction heating cooking appliance as described in any one.

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