JP5295181B2 - Induction heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating cooker which can efficiently cool an induction heating coil by varying cooling capacities corresponding to a heat density distribution on the induction heating coil. <P>SOLUTION: The induction heating cooker comprises a top plate 30 provided on a top face of a housing 1, an induction heating coil 11 provided below the top plate 30, a coil base 12 with the induction heating coil 11 placed on a top face thereof, a cooling fan 14 provided inside the housing 1, and a coil duct 13 disposed below the coil base 12 for guiding air blown from the cooling fan 14 to the induction heating coil 11. The coil duct 13 has a plurality of discharge holes 2 on a top face thereof for discharging air blown from the cooling fan 14 toward the induction heating coil 11. The plurality of discharge holes 2 are adjusted such that air velocities of air emerged from the discharge holes 2 vary corresponding to a heat density distribution on the induction heating coil 11. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an induction heating cooker, and more particularly to an improvement in a cooling structure of an induction heating coil.

  2. Description of the Related Art Conventionally, induction heating cookers are known in which an eddy current is induced by a high-frequency magnetic flux generated by flowing a high-frequency current through an induction heating coil, and an object to be heated is heated by Joule heat generated thereby.

  In recent years, objects to be heated by this induction heating cooker have been diversified, and there are not only iron pots but also nonmagnetic stainless steel pots, copper pots, aluminum pots, and the like. Along with this, induction heating cookers tend to be increased in output in order to realize cooking based on the type of object to be heated.

  The induction heating cooker with high output increases the effective frequency due to the skin effect to increase the frequency, and heat generation increases. Further, since the current value is increased, the self-heating of the induction heating coil is also increased. In order to increase the performance of such an induction heating cooker, it is necessary to efficiently cool the induction heating coil. Therefore, various induction heating cookers have been proposed in which the induction heating coil is efficiently cooled.

  As such, “in the heating coil base 17 having the central portion 23, the outer peripheral portion 24, the plurality of connecting ribs 25 provided across the central portion 23 and the outer peripheral portion 24, and the space 26 generated by the connecting ribs, The height of the connecting rib 25 is set higher than the height of the outer peripheral portion 24, and the induction heating coil 16 is placed on the connecting rib 25. With this configuration, the outer periphery of the induction heating coil and the outer periphery of the heating coil base 17 are arranged. A communication hole is formed between the space 26 and the air passage that connects the space 26 and the communication hole. The cooling air flows through this air path, whereby the induction heating coil can be directly cooled. " It has been proposed (see, for example, Patent Document 1).

  As another example, “a top plate 9 provided on the top frame 8 on the upper surface of the main body 1, and at least an induction heating coil 3 provided below the top plate 9 and a coil base on which the induction heating coil 3 is placed. In an induction heating cooker provided with a coil unit 2 composed of 4, a fan device 16 provided inside the main body 1, and a duct 17 for guiding the air blown by the fan device 16 to the coil unit 2, By providing a plurality of openings 18 having a hole diameter of 3 to 10 mm on the upper surface of the duct 17 positioned below the coil unit 2, and blowing cooling air 28 from the plurality of openings 18 to collide with the lower surface of the coil unit 2. The thing which enabled it to cool an induction heating coil with an air volume is proposed (for example, refer patent document 2).

Japanese Patent Laid-Open No. 2002-43045 (Abstract, FIGS. 1 and 2) Japanese Unexamined Patent Publication No. 2004-214217 (Abstract, FIGS. 1 and 2)

  In the induction heating cooker described in Patent Document 1, cooling air is supplied from below the induction heating coil toward the induction heating coil, and the cooling air flows along the induction heating coil to cool the induction heating coil. Like to do. In this induction heating cooker, since it becomes a laminar flow except directly above the opening, the heat transfer on the back surface of the induction heating coil is low, and the cooling performance is not good. For this reason, there has been a problem that the induction heating coil having a large heat loss cannot be sufficiently cooled.

  In the induction heating cooker described in Patent Document 2, cooling air is jetted from a plurality of openings on the upper surface of the duct located below the coil unit toward the lower surface of the coil unit, that is, the lower surface of the induction heating coil to cool the induction heating coil. Yes. In this induction heating cooker, since the air ejected from the opening becomes a jet, the heat transfer rate is increased and the cooling performance is improved. However, since the plurality of openings have a uniform diameter and a uniform distribution, and uniform ejection is performed over the entire surface of the induction heating coil, there is a bias in the cooling of the induction heating coil where the heat generation density varies depending on the part. . In addition, the induction heating coil is opened with a diameter determined in accordance with the portion having the highest heat generation density, so even a portion having a small heat generation density is cooled by an excessive cooling capacity, However, there was a problem that efficient cooling was not performed.

  The present invention has been made to solve the above-described problems, and induction heating that can efficiently cool the induction heating coil by varying the cooling capacity according to the heat generation density distribution of the induction heating coil. The purpose is to provide a cooker.

An induction heating cooker according to the present invention has a top plate provided on an upper surface of a housing, an induction heating coil provided below the top plate , formed concentrically with multiple rings, and an induction heating coil mounted on the upper surface. A coil base to be placed, a cooling fan provided inside the housing, and a duct arranged below the coil base for guiding the air blown from the cooling fan to the induction heating coil. It has a plurality of discharge holes for discharging the blown air toward the induction heating coil, and the heat generation density of the induction heating coil is larger than the inner peripheral side of the induction heating coil, and is ejected from each discharge hole on the outer periphery side of the induction heating coil as the wind velocity of the air is increased, the diameter of the discharge port facing the outer peripheral side of the induction heating coil, while smaller than the diameter of the discharge holes facing the inner circumferential side, the diameter of the discharge port A duct inside the wind passage sectional area of the portion that fence increased, in which was smaller ducts inside the wind passage sectional area of diameter greater portion of the discharge hole.

  According to the present invention, a plurality of discharge holes adjusted to have different wind speeds of air to be blown into a duct for guiding the air blown from the cooling fan to the induction heating coil according to the heat generation density distribution of the induction heating coil. Thus, the induction heating coil can be effectively cooled according to its heat generation density.

It is a whole perspective view of the induction heating cooking appliance which concerns on Embodiment 1 of this invention. It is a perspective view which shows the positional relationship of the coil duct and coil unit of FIG. It is sectional drawing which shows the positional relationship of the coil duct of FIG. 2, and a coil unit. It is a figure which shows the other example of an induction heating coil. It is a figure which shows the heat generation density distribution at the time of using the induction heating coil of FIG. It is a figure which shows the state by which the small diameter pan was put on the induction heating coil of the multi-ring structure which can be driven independently. It is a figure which shows the heat generation density distribution in the utilization form of FIG. It is sectional drawing which shows the positional relationship of the coil duct and coil unit of the induction heating cooking appliance which concerns on Embodiment 2 of this invention. It is a perspective view which shows the positional relationship of the coil duct and coil unit of the induction heating cooking appliance which concerns on Embodiment 3 of this invention. It is sectional drawing which shows the positional relationship of the coil duct of FIG. 9, and a coil unit. It is a perspective view which shows the positional relationship of the coil duct and coil unit of the induction heating cooking appliance which concerns on Embodiment 4. FIG.

<Embodiment 1>
The present invention will be described below with reference to illustrated embodiments. Note that the present invention is not limited to the embodiments.
FIG. 1 is an overall perspective view of the induction heating cooker according to Embodiment 1 of the present invention, and is a perspective view in a state where a top plate is removed. Here, the induction heating cooker has a built-in type in which cooking pan mounting portions 22a and 22b by induction heating are provided in two on the left and right, and a cooking pan mounting portion 22c by radial heater (RH) heating is provided in the back center. (System kitchen integrated type) An example of an IH cooking heater will be described.

  As shown in FIG. 1, an induction heating cooker 100 according to the present embodiment is opposed to a coil unit 10 a, 10 b (hereinafter may be collectively referred to as a coil unit 10) and a coil unit 10 in a housing 1. Coil ducts 13a and 13b (hereinafter may be collectively referred to as coil duct 13) are provided. Cooling fans 14 a and 14 b (hereinafter sometimes collectively referred to as “cooling fan 14”) and a radiant heater 20 are further provided in the housing 1. Two sets of the coil unit 10, the coil duct 13, and the cooling fan 14 are provided corresponding to two induction heating units. A grill portion 21 is disposed at the center bottom of the housing 1, and a top plate 30 is provided on the top of the housing 1.

  The coil unit 10 includes an induction heating coil 11a, 11b (hereinafter, may be collectively referred to as the induction heating coil 11) for heating an object to be heated such as a pan or a frying pan, and the induction heating coil 11 mounted on the upper surface. Coil bases 12a and 12b (hereinafter may be collectively referred to as the coil base 12).

  A right control board 18a is disposed on the right side of the housing 1, and a right cooling fan 14a is disposed behind the right control board 18a. A coil unit 10a is disposed above the right control board 18a. Similarly, a left control board 18b (not shown) is disposed substantially symmetrically with the right side across the grill portion 21, and a left cooling fan 14b is disposed behind the left control board 18b. The coil unit 10b is disposed above the left control board 18b.

  Each control board 18 (18a, 18b) includes a high frequency power supply unit (not shown) for supplying the induction heating coil 11 with a high frequency power supply and a control unit (not shown). The high-frequency power supply unit includes a circuit formed by a heat generating part such as a switching element, and one or more capacitors connected to the circuit. The control unit controls the entire induction heating cooker including the induction heating coil 11, the radiant heater 20, and a drive motor (not shown) that drives the cooling fan 14.

  The induction heating coil 11 generates an eddy current in the heated object by applying a magnetic field generated by the high-frequency current flowing through the induction heating coil 11 to the heated object placed above the induction heating coil 11, The object to be heated itself generates heat. Further, the radial heater 20 is supplied with AC power of a normal commercial frequency, and the heater itself generates heat, whereby the object to be heated is heated by the radiant heat.

  The cooling fan 14 blows air that cools the induction heating coil 11. In the first embodiment, the case where the cooling fan 14 is an axial fan is shown as an example, but the present invention is not limited to this.

  The case where the top plate 30 is a glass top formed of heat-resistant glass or the like will be described as an example. The glass top 30 is provided on the upper surface of the housing 1. And the glass top 30 can mount the to-be-heated material heated. The glass top 30 is formed with three cooking pot placing portions 22a, 22b, and 22c (hereinafter may be collectively referred to as the cooking pot placing portion 22). The cooking pot placing unit 22 indicates a part on which the object to be heated is placed on the glass top 30. In other words, the cooking pot mounting unit 22 is disposed at two locations on the left and right sides of the housing 1 so as to correspond to the induction heating coil 11 and at one location in the center of the back of the housing 1 so as to correspond to the radiant heater 20. Has been. In addition, although the case where the glass top 30 is comprised with heat resistant glass is shown as an example here, it is not limited to this.

  Behind the glass top 30, the cooling fan 14 sucks outside air from the outside of the housing 1, and the air taken into the housing 1 to cool the inside of the housing 1. 1 An exhaust port 16 for exhausting to the outside is formed. Here, the case where the intake port 15 and the exhaust port 16 are formed behind the glass top 30 is shown as an example. However, the present invention is not limited to this. For example, the intake port 15 and the exhaust port behind the glass top 30 are used. 16 may be omitted and formed on the front surface and the back surface of the housing 1.

  Further, an operation panel 19 for receiving support from the user is provided in front of the glass top 30. That is, when an instruction is given from the user via the operation panel 19, the control unit on the control board 18 controls the induction heating coil 11 and the radiant heater 20 based on the contents of the instruction. Further, the control unit controls heating / discharging of the induction heating coil 11 and the radiant heater 20 based on the temperature detected from a temperature sensor (not shown).

FIG. 2 is a perspective view showing a positional relationship between the coil duct and the coil unit shown in FIG. FIG. 3 is a cross-sectional view showing the positional relationship between the coil duct and the coil unit shown in FIG. FIG. 3 also shows the heat generation density distribution of the induction heating coil of FIG. Moreover, in FIG. 3, the arrow has shown the flow of air, and the magnitude | size of the arrow has shown the magnitude | size of the wind speed.
The coil base 12 of the coil unit 10 is provided with a rod-like ferrite 17 for preventing the magnetic field lines generated from the induction heating coil 11 from flowing downward and concentrating the magnetic field lines on the object to be heated. In the present embodiment, as an example, a plurality of rod-like ferrites 17 are mounted radially around a ventilation hole 12 c provided in the center of the coil base 12. The ventilation hole 12 c is for supplying air blown from the cooling fan 14 to the surface of the induction heating coil 11. Although not shown in the drawing, the coil base 12 is preferably provided with a temperature sensor for detecting the temperature state of the object to be heated.

  The coil base 12 is supported from below by a support member (not shown) and is pressed so as to be in close contact with the top plate 30. In addition, this support member should just support the coil bases 12, such as a spring, and does not specifically limit a kind and number.

  The coil duct 13 is formed in a substantially circular shape when viewed from above so that the coil base 12 of the coil unit 10 can be placed thereabove, and is disposed opposite to the lower surface of the coil base 12. A plurality of discharge holes 2 for ejecting air from the cooling fan 14 toward the induction heating coil 11 are formed in the upper surface of the coil duct 13 (the surface facing the coil base 12).

  It has been found that the heat generation density distribution generated when the induction heating coil is driven varies depending on the method of forming the induction heating coil. For example, when the induction heating coil 11 is formed in a single ring shape as shown in FIG. 4, the heat generation density in the vicinity of the center of the ring band is the highest during driving as shown in FIG. Distribution. In addition, when the coil is formed in a concentric multiple (in this case, double) ring like the induction heating coil 11 of the first embodiment shown in FIG. 2, the heat generation density is a ring as shown in FIG. The distribution becomes higher near the center of each ring band, although it weakens in the middle part. However, even in the case of the same multiple rings, this is not limited to the case where individual driving is possible for each ring, and when heating a pot with a small diameter as shown in FIG. 6, the inner ring band as shown in FIG. The distribution is such that the heat generation density near the center is the highest. As described above, since the heat generation density distribution differs depending on the method of forming the induction heating coil mainly by the control method, it is preferable that the portion where the heat generation density is high is cooled with a higher cooling capacity than the portion where the heat generation density is low. That is, it is effective to change the cooling capacity according to the heat generation density distribution of the induction heating coil 11 and cool it.

  In the case of cooling by a jet flow from the discharge hole 2 as in this example, the higher the jet velocity (wind speed), the higher the cooling capacity. For this reason, the wind speed with respect to a site | part with a high heat generation density is made faster than a part with a low heat generation density. In the first embodiment, the wind speed is changed by changing the diameters of the plurality of discharge holes 2 in accordance with the heat generation density distribution, and the diameter of the discharge holes 2 corresponding to the portion where the heat generation density is large is reduced. In addition, the diameter of the discharge hole 2 corresponding to the portion where the heat generation density is small is increased. Specifically, in the first embodiment, the plurality of discharge holes 2 are arranged in a ring shape of a plurality of layers (here, three layers) centering on a portion corresponding to the ventilation hole 12c provided in the center of the coil base 12. A small-diameter discharge hole 2a, a medium-diameter discharge hole 2b, and a large-diameter discharge hole 2c are formed in this order from the outer ring. As a result, as indicated by the arrows in FIG. 3, it is possible to increase the wind speed with respect to the part having a high heat generation density as compared with the part having a low heat generation density.

  Next, the cooling operation of the induction heating coil 11 will be described. First, the cooling fan 14 sucks air from the intake port 15 behind the glass top 30 and blows the air to the control board 18 and the coil duct 13. The air that has reached the coil duct 13 is ejected from the plurality of discharge holes 2 on the upper surface of the coil duct 13 toward the coil base 12 and collides with the lower surface of the coil base 12 to cool the induction heating coil 11. The air that has cooled the induction heating coil 11 flows along the lower surface of the glass top 30 in a state where the temperature rises due to heat exchange with the induction heating coil 11, and is discharged to the outside from the exhaust port 16 behind the glass top 30. The

  Here, in the first embodiment, as described above, the diameter of the discharge hole 2 provided in the coil duct 13 is small at a position corresponding to a portion having a large heat generation density, and large at a position corresponding to a portion having a low heat generation density. doing. If the same air volume is supplied to each discharge hole 2, the wind speed is faster in the discharge hole 2 with a small diameter, and conversely, the wind speed is slow in the discharge hole 2 with a large diameter. For this reason, in the induction heating coil 11, a portion having a large heat generation density is cooled with high cooling capacity by air having a high wind speed, and a portion having a low heat generation density is cooled by air having a slower wind speed than a portion having a large heat generation density. Cooled with capacity.

  As described above, according to the first embodiment, the diameter of the discharge hole 2 of the coil duct 13 is changed in accordance with the heat generation density, and the wind speed of the cooling air ejected toward the induction heating coil 11 is distributed. Therefore, the induction heating coil 11 can be effectively cooled according to the heat generation density. Further, by changing the diameter of the discharge hole 2, the total air volume blown toward the induction heating coil 11 can be appropriately dispersed for each part and can be cooled with a minimum necessary air volume without waste. There is no need to supply air to the duct 13 more than necessary. For this reason, low noise and energy saving can be realized by reducing the rotational speed of the cooling fan 14.

  Further, as compared with the conventional cooling method in which uniform discharge holes 2 are formed in the coil duct 13 and uniform ejection is performed as in the prior art, cooling can be performed more effectively, so that the number of discharge holes 2 is not increased unnecessarily. It can be the minimum number. For this reason, the pressure loss by the collision of the air after ejecting from the discharge hole 2 can be reduced. Therefore, also from this aspect, it is possible to realize noise reduction and energy saving by reducing the rotational speed of the cooling fan 14.

  As described above, highly efficient induction heating coil cooling with a low air volume and low pressure loss can be realized, and the specification of the cooling fan can be reduced. Therefore, the effect of extending the life can be expected.

  Here, the diameter of the discharge hole 2 is three stages, but it may be further plural stages or two stages according to the heat generation density distribution.

<Embodiment 2>
In the second embodiment, in addition to the configuration of the first embodiment, the cross-sectional area of the air passage in the coil duct 13 from the suction hole of the coil duct 13 toward each discharge hole 2 is made different according to the heat generation density distribution. Is.

  FIG. 8 is a cross-sectional view showing the positional relationship between the coil duct and the coil unit of the induction heating cooker according to Embodiment 2 of the present invention. FIG. 8 also shows the heat generation density distribution of the induction heating coil. In FIG. 8, the same parts as those in the first embodiment shown in FIG. The perspective view of the coil duct and coil unit of the induction heating cooking appliance which concerns on Embodiment 2 is the same as that of Embodiment 1 shown in FIG. Below, it demonstrates centering on the point which Embodiment 2 differs from Embodiment 1. FIG.

  The coil duct 13 of the induction heating cooker of the second embodiment is formed with a plurality of discharge holes 2 whose diameters are changed according to the heat generation density distribution of the induction heating coil 11 on the upper surface, as in the first embodiment. Yes. Furthermore, in Embodiment 2, it has the inclined surface 13B which protrudes upwards as it goes to a center part from an outer peripheral part inside the lower surface of the coil duct 13. As shown in FIG. Thereby, the cross-sectional area of the air passage inside the coil duct 13 from the suction hole 13A of the coil duct 13 toward each discharge hole 2 becomes large at a place where the diameter of the discharge hole 2 is small, and at a place where the diameter of the discharge hole 2 is large. Get smaller.

  With this configuration, the resistance of the air passage in the coil duct 13 corresponding to the discharge hole 2 having a small diameter is reduced at a portion where the heat generation density is large. Therefore, the diameter of the cooling air that has entered the coil duct 13 is small. The amount of cooling air supplied to the small discharge hole 2 increases, and jet air with a high speed can be reliably ejected. On the other hand, in the part where the heat generation density is small, the ventilation resistance of the air passage in the coil duct 13 corresponding to the discharge hole 2 having a large diameter is large, so that the cooling air entering the coil duct 13 is supplied to the discharge hole 2 having a large diameter. The amount of cooling air to be discharged is reduced, and jet air having a lower speed than the discharge hole 2 having a small diameter is ejected. As a result, a part with a large heat generation density is cooled with a high cooling capacity, and a part with a low heat generation density is cooled with a low cooling capacity.

  As described above, according to the second embodiment, the same effect as in the first embodiment can be obtained, and the inclined surface 13B is provided on the inner side of the lower surface of the coil duct 13 so that the air passage cross-sectional area inside the coil duct 13 is provided. Is configured to be wide at a portion having a high heat generation density and narrow at a portion having a low heat generation density. Thereby, compared with Embodiment 1, the wind speed of a site | part with a large heat_generation | fever density can be raised further, and it becomes possible to cool with a higher cooling capacity. On the other hand, the wind speed can be suppressed for a portion having a small heat generation density, the cooling capacity can be suppressed, and effective cooling can be achieved.

<Embodiment 3>
In the third embodiment, the number of the discharge holes 2 is changed according to the heat generation density distribution so that the wind speed of the air ejected from the coil duct 13 has a distribution.

  FIG. 9 is a perspective view showing a relationship between a coil base and a coil duct mounted on the induction heating cooker according to Embodiment 3 of the present invention. 10 is a cross-sectional view showing the positional relationship between the coil duct and the coil unit shown in FIG. FIG. 10 also shows the heat generation density distribution of the induction heating coil of FIG. Further, in FIG. 9 and FIG. 10, the same parts as those in the first embodiment shown in FIG. 2 and FIG. Below, it demonstrates centering on the point from which Embodiment 3 differs from Embodiment 1. FIG.

  The coil duct 13 of the induction heating cooker according to the third embodiment has a uniform diameter on its upper surface so that the amount of air blown to the coil base 12 changes according to the heat density distribution of the induction heating coil 11. The number of such discharge holes 2 is changed. Specifically, in Embodiment 1 and Embodiment 2 shown in FIGS. 2 and 3, the number of discharge holes 2 in each ring arranged in a triple ring is the same. In the third aspect, the number of the discharge holes 2 constituting the innermost ring corresponding to the portion having a small heat generation density is minimized, and the number of the discharge holes 2 is increased as it becomes the outer ring and the outer ring. Yes.

  Thus, on the upper surface of the coil duct 13, the ventilation resistance is reduced by increasing the number of the discharge holes 2 in the portion where the heat generation density of the induction heating coil 11 is large. Therefore, heat is generated in the cooling air entering the coil duct 13. The amount of cooling air supplied to the discharge holes 2 facing the portion having a high density is increased, and the cooling speed can be increased by increasing the speed of the air blown from there. On the contrary, since the ventilation resistance is increased by reducing the number of the discharge holes 2 at the portion where the heat generation density is low, the cooling air supplied to the discharge hole 2 for the portion where the heat generation density is low among the cooling air entering the coil duct 13. The air volume is reduced, and the cooling speed can be suppressed by reducing the speed of the air blown from there. By comprising in this way, the induction heating coil 11 can be cooled effectively according to the heat generation density.

  As described above, according to the third embodiment, the number of discharge holes 2 having the same diameter is changed in accordance with the heat generation density distribution, and the distribution of the wind speed of the air blown toward the induction heating coil 11 is given. The induction heating coil 11 can be effectively cooled according to its heat generation density. In addition, by changing the number of discharge holes 2, the total air volume blown toward the induction heating coil 11 can be appropriately dispersed for each part, and can be cooled with a minimum necessary air volume without waste. There is no need to supply air to the duct 13 more than necessary. For this reason, it is possible to realize a reduction in noise by reducing the rotational speed of the cooling fan 14.

  Further, as compared with the conventional cooling method in which uniform discharge holes 2 are formed in the coil duct 13 and uniform ejection is performed as in the prior art, cooling can be performed more effectively, so that the number of discharge holes 2 is not increased unnecessarily. It can be the minimum number. For this reason, the pressure loss by the collision of the air after ejecting from the discharge hole 2 can be reduced. Therefore, also from this aspect, it is possible to realize noise reduction and energy saving by reducing the rotational speed of the cooling fan 14.

  As described above, highly efficient induction heating coil cooling with a low air volume and low pressure loss can be realized, and the specification of the cooling fan can be reduced. Therefore, the effect of extending the life can be expected.

<Embodiment 4>
In the first to third embodiments, the induction heating coil 11 is configured by one coil configured by one winding wire, but in the fourth embodiment, the induction heating coil 11 is configured by two independent annular winding wires. It is configured with two coils.

FIG. 11: is a perspective view which shows the relationship between the coil duct and coil unit of the induction heating cooking appliance which concerns on Embodiment 4 of this invention. In FIG. 11, the same parts as those of the first embodiment shown in FIG.
The induction heating coil 31 of the induction heating cooker according to the fourth embodiment has a configuration in which two coils 31A and 31B configured by two independent annular winding wires are arranged concentrically. The coils 31A and 31B can be independently driven and controlled. Other configurations are the same as those of the first embodiment shown in FIG.

  According to the fourth embodiment configured as described above, the same function and effect as those of the first embodiment can be obtained. In addition, although the example which replaced the induction heating coil 11 with the induction heating coil 31 in the structure of Embodiment 1 shown in FIG. 2 was shown here, in Embodiment 2 and Embodiment 3, the induction heating coil 31 is shown. It is good also as a structure replaced with. In this case, the same effect as in the second and third embodiments can be obtained. In addition, the induction heating coil of the present invention is not limited to one formed by concentrically winding multiple rings, and one formed by winding a single ring as shown in FIGS. Shall be included.

  In each of the above embodiments, the example in which the discharge holes 2 are arranged in a plurality of annular shapes has been described. However, the present invention is not limited to the annular arrangement, and the discharge holes having the characteristics of the respective embodiments. 2 may be used.

  Moreover, although each said embodiment demonstrated to the example the case where the induction heating cooking appliance was equipped with two induction heating coils 11, it does not limit to this. For example, an induction heating cooker including one induction heating coil 11 or an induction heating cooker including three or more induction heating coils 11 may be used. Moreover, although the glass top shape | molded with glass was demonstrated to the example as the top plate 30, it does not limit to this.

  Further, in each of the above embodiments, the case where the induction heating cooker is used for a built-in type (system kitchen integrated type) IH cooking heater has been described as an example. However, the present invention is not limited to this. Needless to say, the same effects can be obtained even when used in a cooking heater.

  The induction heating cooker according to the present invention can be applied to a built-in induction heating cooker as well as a built-in type.

  DESCRIPTION OF SYMBOLS 1 Housing | casing, 2 discharge hole, 10 coil unit, 11 induction heating coil, 12 coil base, 12c ventilation hole, 13 coil duct, 13A suction hole, 13B inclined surface, 14 cooling fan, 15 intake port, 16 exhaust port, 17 Ferrite, 18 control board, 19 operation panel, 20 radiant heater, 21 grill section, 22 cooking pot mounting section, 30 glass top (top plate), 31 induction heating coil, 100 induction heating cooker.

Claims (1)

A top plate provided on the upper surface of the housing;
An induction heating coil provided below the top plate and formed concentrically with multiple rings ;
A coil base on which the induction heating coil is mounted;
A cooling fan provided inside the housing;
A duct that is disposed below the coil base and guides the air blown from the cooling fan to the induction heating coil;
The duct has a plurality of discharge holes for discharging air blown from the cooling fan toward the induction heating coil,
On the outer peripheral side of the induction heating coil, the wind speed of the air ejected from each discharge hole is faster on the outer peripheral side of the induction heating coil, where the heat generation density of the induction heating coil is larger than the inner peripheral side of the induction heating coil. While forming the diameter of the discharge holes facing each other smaller than the diameter of the discharge holes facing the inner peripheral side,
The air passage cross-sectional area inside the duct of the portion where the diameter of the discharge hole is reduced is increased, and the air passage cross-sectional area inside the duct of the portion where the diameter of the discharge hole is increased is reduced. Induction heating cooker.

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