JP3702076B2 - Induction heating cooker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an induction heating cooker including a plurality of heating coils arranged below a top plate on which a cooking container is placed and a plurality of inverters for driving the coils.
[0002]
[Prior art]
FIG. 7 is a perspective view showing a conventional example in the case where such an induction heating cooker is incorporated into a cooking table of a system kitchen. Although not specifically shown, the upper body 1 of the induction heating cooker is a halogen whose heat source is an electric heater such as a coil heater or a halogen lamp that radiates infrared rays in a rectangular box-shaped body case having an open upper surface. A plurality of heating means including a heater or a heating coil that performs induction heating is disposed. On the upper surface of the main body case, a top plate 2 made of heat-resistant glass is disposed together with an outer frame 3 that supports the top plate 2.
[0003]
On the surface of the top plate 2, there are two induction heating units 4 and 5 on the front side corresponding to the position where the plurality of heating means are disposed, and on the back side, the heater heating unit There are six. In addition, after the outer frame 3 positioned on the back side of the top plate 2, intake ports 7 and 8 for taking in air for cooling electrical components such as induction heating coils are provided on both the left and right sides. And 8, an exhaust port 9 is provided. And the upper main body 1 is inserted from the upper part into the insertion part of the rectangular opening formed in the top plate 11 of the cooking table 10 of the system kitchen, and is supported by the cooking table 10 by the outer frame 3.
[0004]
On the other hand, the lower main body 12 is fitted into the lower portion of the upper main body 1 from the front side of the cooking table 10. A roaster portion 13 is provided on the left side of the front surface of the lower main body 12, and an operation / display portion 14 is provided on the right side for performing cooking operations and various displays according to the operations. Is provided. Further, a cooling air exhaust port 15 is provided in a horizontally long rectangular shape at a position located above the roaster unit 13 and the operation / display unit 14.
[0005]
FIG. 8 is a plan view showing an internal configuration mainly related to cooling of the upper main body 1 with the top plate 2 removed. When performing induction heating, a switching element such as an IGBT that constitutes an inverter that supplies a high-frequency current to the heating coil mainly generates heat. In order to efficiently cool the switching element, air taken from the outside by a cooling fan is blown as cooling air to cool the heat radiating plate attached to the switching element.
[0006]
That is, in FIG. 8, the main circuits (not shown) of the inverter corresponding to the induction heating units 4 and 5 are configured on the boards 16 and 17 arranged on the left and right front sides of the upper main body 1. Then, heat sinks 18a and 18b, 19a and 19b having a large number of fins for cooling the positive and negative switching elements constituting the main circuit are provided on the substrates 16 and 17, respectively. A substrate 20 on which control circuits (not shown) for two inverters are mounted is disposed on the central back side of the upper body 1.
[0007]
Ducts 21 and 22 are provided on both the left and right sides in the upper body 1 so as to communicate with the air inlets 7 and 8, respectively, and cooling fans 23 and 24 are disposed inside the ducts 21 and 22, respectively. On the leeward side of the fans 23 and 24, heat radiating plates 18a and 18b, 19a and 19b are arranged.
[0008]
The cooling fans 23 and 24 blow the cooling air sucked from the intake ports 7 and 8 to the heat radiating plates 18a and 18b, 19a and 19b, and are exhaust ports provided on the front side and the back side of the upper main body. By evacuating from 15 and 9, the switching element is cooled.
[0009]
[Problems to be solved by the invention]
However, in the induction heating cooker having such a conventional configuration, the intake ports 7 and 8, the ducts 21 and 22, the cooling fans 23 and 24, etc. are provided corresponding to the induction heating units 4 and 5. The structure inside the main body 1 becomes complicated and the number of parts increases, resulting in a problem that the degree of freedom of design in the upper main body 1 is limited by these cooling structures.
[0010]
This invention is made | formed in view of the said situation, The objective is to provide the induction heating cooking appliance which can cool a some inverter with a simple cooling structure.
[0011]
[Means for Solving the Problems]
  In order to achieve the above object, an induction heating cooker according to claim 1 includes a top plate on which a cooking container is placed;
  A plurality of heating coils arranged below the top plate for induction heating the cooking vessel, and a plurality of inverters for supplying a high-frequency current to the heating coils;
  A plurality of heat sinks attached to switching elements constituting the plurality of inverters;
  A cooling fan that blows cooling air;
  A duct for guiding cooling air blown from the cooling fan,
  The plurality of heat sinks are arranged inside the duct.PutThe
[0012]
  If comprised in this way, the switching element which comprises several inverters can be cooled together by arrange | positioning one cooling fan in the inside of a duct, and blowing cooling air to several heat sinks. The cooling structure becomes simple.
  Then, the inverter is configured as a half-bridge type, the heat sink is provided independently for the positive side switching element and the negative side switching element, and the heat sink provided in the negative side switching element is arranged on the windward side inside the duct. When a half-bridge type inverter that does not generate interference sound even if driven at the same time is installed, the heat sink of the negative switching element with a longer ON period and a large amount of heat generation is installed on the windward side inside the duct. It can arrange | position to and can cool efficiently.
  Further, as described in claim 2, the inverter is configured as a half-bridge type,
  A heat sink is provided independently for each of the positive side switching element and the negative side switching element,
  You may arrange | position the heat sink provided in the positive side switching element closely.
  With such a configuration, when a switching element having a non-insulated package is employed, the heat sinks provided on the positive side switching element are always at the same potential, so they may be arranged close to each other. Since there is no problem in insulation, it is possible to secure an arrangement space for other components.
[0013]
  In this case, the claim3As described above, it is preferable to provide a wind direction plate that divides the air passage of the cooling air into a plurality of air inside the duct. If comprised in this way, the air volume suitable for cooling each inverter can be supplied to the several air path divided | segmented with the wind direction board.
[0014]
  Claims4As described above, an insulating wall that insulates a plurality of heat sinks may be provided inside the duct. If comprised in this way, even when the switching element which has a non-insulation type package with sufficient cooling efficiency is employ | adopted, the short circuit between switching elements via a heat sink can be prevented.
[0015]
  Further claims5As described in the above, it is preferable to arrange a heat radiating plate provided in an inverter having a large rated output among a plurality of inverters on the windward side inside the duct. If comprised in this way, the switching element with much more calorific value can be cooled efficiently.
[0016]
  Claim6As described above, a plurality of heat sinks are provided per inverter,
  Among the plurality of inverters, a plurality of inverter-side heat sinks with a large rated output are arranged in parallel with the direction of the cooling air inside the duct, and a plurality of inverter-side heat sinks with a small rated output are arranged in the direction of the wind. On the other hand, it is good to arrange in series.
[0017]
If comprised in this way, while arranging the several heat sink of the inverter side with a large rated output in parallel with respect to the wind direction of a cooling wind, while being able to cool a switching element with much emitted-heat amount efficiently, By arranging a plurality of inverter-side heat sinks with a low rated output in series with respect to the wind direction, it is possible to secure an arrangement space for other components.
[0018]
  Claim7As described above, a plurality of heat sinks are provided per inverter,
  You may arrange | position the several heat sink provided in each inverter in series with respect to the wind direction of the cooling air inside a duct, respectively. If comprised in this way, the flow of a cooling wind can be smoothly guide | induced with a heat sink.
[0022]
  Claim8As described above, it is preferable to configure a plurality of inverters on a single substrate. With such a configuration, a simple configuration is obtained, the assemblability is improved, and the cost can be reduced.
[0023]
  Claim9As described above, it is preferable that the connection terminal for connecting the inverter and the heating coil is disposed on the substrate on which the inverter is configured and at a site located outside the duct. If comprised in this way, the connection of an inverter and a heating coil can be performed without removing a duct.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the first embodiment when the induction heating cooker of the present invention is applied to a built-in induction heating cooker used by being incorporated in a kitchen table of a system kitchen will be described with reference to FIGS. explain. The induction cooking device of the present embodiment has two induction heating cooking units (not shown) on the left and right front sides of the upper main body, similarly to the configuration shown in the prior art. FIG. 3 is a diagram illustrating an electrical configuration of the induction heating cooking unit. In FIG. 3, the AC input terminal of the rectifier circuit 31 formed of a diode bridge is connected to a commercial AC power supply 32, and the DC output terminal is connected to both ends of the smoothing capacitor 34R via a choke coil 33R. Yes.
[0025]
Both ends of the smoothing capacitor 34R are connected to arms made up of positive and negative IGBTs (switching elements) 37R and 38R via DC buses 35R and 36R, so that a half-bridge inverter 39R is connected. It is composed. Free wheel diodes D1R and D2R are connected between the collectors and emitters of the IGBTs 37R and 38R, respectively. One end of the heating coil 40R is connected to the output terminal 39Ra of the inverter 39R, and a parallel circuit of a resonant capacitor 41R and a diode 42R is connected between the other end of the heating coil 40R and the DC bus 36R. Yes.
[0026]
The output terminal of the drive circuit 43R is connected to the gates of the IGBTs 37R and 38R. When receiving a control signal from a control circuit (not shown), the drive circuit 43R outputs a drive signal to the gates of the IGBTs 37R and 38R according to the control signal.
[0027]
In addition, the above shows the electrical configuration corresponding to the induction heating cooking unit on the right side. The same circuit corresponding to the induction heating cooking unit on the left side is connected in parallel to the DC output terminal of the rectifier circuit 31. In FIG. Yes.
[0028]
In the inverter 39R, the negative-side IGBT 38R is always turned on at a duty of about 50% in the latter half of a constant period of about 20 KHz, and the amount of current supplied to the heating coil 40R is constant for the positive-side IGBT 37R. Control is performed by changing the on-time duty in the first half of the cycle between 0% and less than 50%. Accordingly, even when the left and right inverters 39R and 39L are operated simultaneously, the operating frequency of both is always constant, so that no interference sound due to the frequency difference is generated.
[0029]
The operation of the inverter 39R is composed of the following four cycles.
(1) IGBT37R: ON / IGBT38R: OFF
While supplying a current to the heating coil 40R, the resonant capacitor 41R is charged.
(2) IGBT37R: Off / IGBT38R: Off
The resonance capacitor 41R is further charged by the delay current of the heating coil 40R.
(3) IGBT37R: OFF / IGBT38R: ON
The resonant capacitor 41R is discharged, and a current in the reverse direction is passed through the heating coil 40R.
(4) IGBT37R: Off / IGBT38R: Off
The delay current of the heating coil 40R is regenerated to the power supply side via the diode D1R.
By repeating the above cycle, a high frequency current is supplied to the heating coil 40R.
[0030]
FIG. 1 is a plan view showing the internal configuration mainly relating to the cooling structure of the upper main body 45 with the top plate removed, similarly to FIG. A substrate 44 on which a control circuit is configured is disposed on the left back side, and a power transformer 46 that supplies power to the control circuit is disposed on the left front side.
[0031]
In addition, a rectangular substrate 47 is disposed on the right front side, and on the substrate 47, four IGBTs 37R, 38R, which constitute inverters 39R, 39L corresponding to the left and right induction heating cooking units are arranged. 37L and 38L (see FIG. 2; however, those corresponding to 38L are not shown). The four IGBTs 37R, 38R, 37L, and 38L are respectively attached with heat sinks 48R, 49R, 48L, and 49L having a plurality of fins.
[0032]
The rated outputs of the inverters 39L and 39R corresponding to the left and right induction heating cooking units are, for example, 3 KW and 2 KW, and the left output is set higher. Accordingly, since the heat generation amounts of the IGBTs 37L and 38L are larger than those of the IGBTs 37R and 38R, the heat capacity (that is, the outer size) of the heat radiating plates 48L and 49L is set larger than that of the heat radiating plates 48R and 49R.
[0033]
The IGBTs 37R, 38R, 37L and 38L use non-insulating type packages with high heat dissipation efficiency, and the heat sinks 48R, 49R, 48L and 49L are electrically connected to the collectors of the IGBTs 37R, 38R, 37L and 38L. Has been. Further, on the left side of the substrate 47, from the top to the bottom in FIG. 1, the heat radiating plates 49L, 48L, 49R are arranged side by side, and the heat radiating plate 48R is arranged vertically on the right side of the substrate 47.
[0034]
A cooling fan 50 is disposed on the right rear side of the upper main body 45. And the duct 51 is arrange | positioned so that this heat sink 48R-49L on this cooling fan 50 and the board | substrate 47 may be covered. A casing 51a having a shape surrounding the cooling fan 50 is communicated with the duct 51, and openings 51b and 51b are provided on the upper and lower sides of a portion of the casing 51a corresponding to the center of the cooling fan 50, respectively.
[0035]
Here, FIG. 2 shows a longitudinal section of the upper main body 45 concerning the cooling fan 50 and the heat radiating plates 49L, 48L, 49R. In FIG. 2, a driving motor 52 is disposed below the cooling fan 50. An intake port 53 is provided on the right rear side of the upper main body 45, and a cover 45a that allows the upper opening 51b to communicate with the intake port 53 is disposed in an upper part of the casing 51a.
[0036]
Also, a cover 45b that covers the motor 52 and communicates the lower opening 51b with the air inlet 53 is disposed at the bottom of the upper main body 45, and the cooling fan 50 rotates to suck air from the air inlet 53. The cooling air thus taken is taken in from the openings 51b and 51b of the casing 51a and blown to the heat radiating plates 48R to 49L arranged on the leeward side.
[0037]
In FIG. 2, a top plate 54 installed on the upper portion of the upper main body 45 is illustrated, and a heating coil 40 </ b> R is disposed immediately below the top plate 54.
[0038]
As for the arrangement of the radiator plates 48R to 49L, the radiator plates 48L and 49L are arranged in parallel to the direction of the cooling air, and the radiator plates 48R and 49R are arranged in series. Wind direction plates 55 and 56 are provided between the heat radiating plates 49L and 48L and between the heat radiating plates 48L and 49R so as to partition the two. In FIG. 2, the IGBTs 38 </ b> L, 37 </ b> L, and 38 </ b> R are supported by soldering leads (not shown) to the substrate 47.
[0039]
The wind direction plates (insulating walls) 55 and 56 are made of, for example, synthetic resin. And the base end part of the wind direction boards 55 and 56 is attached to the duct 51, and the front-end | tip part extends to the surface vicinity of the board | substrate 47, and partitions between each heat sink. The wind direction plates 55 and 56 are extended in the windward direction while gently curving along the cooling air flow path 57 in the duct 51, and the air flow path 57 extends from the middle to the three wind paths 57 a and 57 a. It is divided into 57b and 57c. That is, the radiator plates 49L, 48L and 48R, 49R are arranged in the air passages 57a, 57b and 57c, respectively.
[0040]
As shown in FIG. 1, an exhaust port 58 is provided on the left back side of the upper main body 45, and the cooling air discharged from the duct 51 by cooling the heat radiating plates 48 </ b> R to 49 </ b> L from the exhaust port 58 to the outside. It is supposed to be discharged. Further, in order to connect the output terminals 39Ra and 39La of the two inverters 39R and 39L and the (two) heating coils 40R and 40L so as to be positioned outside the duct 51 at the upper left and lower right of the substrate 47. Connection terminals 59R and 59L are provided.
[0041]
According to the present embodiment configured as described above, the following operational effects can be obtained. That is, when performing induction heating cooking, by driving the inverters 39R and 39L as described above, a high frequency current is supplied to the heating coils 40R and 40L, and at the same time, the cooling fan 50 is driven to rotate, thereby rotating each IGBT 37R. Cool ~ 38L.
[0042]
At this time, the heat radiation plates 48R, 49R, 48L, and 49L attached to the IGBTs 37R, 38R, 37L, and 38L are disposed inside the duct 51, so that they are provided corresponding to the two induction heating cooking units. The IGBTs 37R and 38R, 37L and 38L constituting the two inverters 39R and 39L can be cooled together by a single cooling fan 50, thereby simplifying the cooling structure inside the upper main body 45 and reducing the cost. Can be planned.
[0043]
Further, according to the present embodiment, since the wind direction plates 55 and 56 for dividing the cooling air flow path 57 into three are provided in the duct 51, the air flow direction plates 55 and 56 are arranged between the duct 51 and the wind direction plate 55. By appropriately adjusting the distance between the wind direction plate 56 and the duct 51, the IGBTs 37R and 38R, 37L and 38L are cooled in the three air paths 57a, 57b and 57c divided by the wind direction plates 55 and 56, respectively. It is possible to supply an appropriate air volume.
[0044]
Further, since the wind direction plates 55 and 56 are made of an insulating synthetic resin, the wind direction plates 55 and 56 also have a function as an insulating wall, and the heat radiation plates 49L-48L and 48L-49R are interposed therebetween. Thus, it is possible to prevent a short circuit between the IGBTs 38L and 37L and between the IGBTs 37R and 38R.
[0045]
In addition, according to the present embodiment, the radiators 48L and 49L on the inverter 39L side having a large rated output are arranged in parallel with the direction of the cooling air inside the duct 51, and the inverter 39R side having a small rated output is arranged. Since the plurality of heat radiating plates 48R and 49R are arranged in series with respect to the wind direction, the IGBTs 37L and 38L having a large amount of heat generation can be efficiently cooled, and the arrangement space for other components is secured in the upper main body 45. can do.
[0046]
In addition, since the intake port 53 is provided on the right back side of the upper body 45 and the exhaust port 58 is provided on the left back side of the upper body 45, a sufficient distance between the two can be secured. Is not configured, and cooling can be performed more efficiently.
[0047]
Furthermore, according to the present embodiment, since the two inverters 39R and 39L are configured on the single substrate 47, a simple configuration is obtained, the assemblability is improved, and the cost can be reduced. And since the connection terminals 59R, 59L for connecting the inverters 39R, 39L and the heating coils 40R, 40L are arranged on the substrate 47 and at the part located outside the duct 51, the connection between them is This can be performed without removing the duct 51, and workability can be improved.
[0048]
FIG. 4 shows a second embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof will be omitted. Only different parts will be described below. In the second embodiment, the rated outputs of the inverters 39L and 39R corresponding to the left and right induction cooking units are both equal, for example, set to 2.5 KW and 2.5 KW.
[0049]
The heat capacities of the four heat radiating plates 60L, 61L, 60R, 61R are all set equal. On the substrate 47, the heat radiating plates 60L and 61L and the heat radiating plates 60R and 61R are arranged side by side in the left-right direction in FIG. 4, and the inverters 39L and 39R are connected to the direction of the cooling air in the duct 51. Corresponding ones are arranged in series.
[0050]
However, in both cases, the radiator plates 61L and 61R attached to the IGBTs 38L and 38R on the negative side of the inverters 39L and 39R are arranged so as to be on the upstream side of the cooling air. Also, between the heat sinks 60L-60R and between the heat sinks 61L-61R, synthetic resin insulating walls 62a, 62b are provided in place of the wind direction plates 55, 56 of the first embodiment, respectively. The short circuit between them is prevented. Other configurations are the same as those of the first embodiment.
[0051]
According to the second embodiment configured as described above, the following operational effects are obtained. That is, when performing the induction cooling of the IGBTs 37L to 38R by the cooling fan 50 when performing induction heating cooking as in the first embodiment, the heat radiating plates 60L and 61L and the heat radiating plates 60R and 61R are respectively in series with the wind direction. Therefore, the cooling air can be smoothly blown to the heat radiating plates 60L, 61L, 60R, 61R without providing the wind direction plates 55, 56 and the like.
[0052]
Further, in the half-bridge type inverters 39L and 39R, the negative side IGBTs 38L and 38R are always turned on with a 50% duty as described above, so that the amount of heat generation (loss) is larger than that of the positive side IGBTs 37L and 37R. Therefore, the cooling effect of the negative side IGBTs 38L and 38R can be further enhanced by arranging the heat sinks 61L and 61R attached to the negative side IGBTs 38L and 38R so as to be on the upstream side of the cooling air.
[0053]
FIG. 5 shows a third embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted. Only different parts will be described below. In the third embodiment, the heat radiating plates 48L and 49L attached to the IGBTs 37L and 38L on the inverter 39L side having a large rated output are arranged so as to be on the upper side of the cooling air in the duct 51, and the heat radiating on the inverter 39R side. The plates 48R and 49R are arranged so as to be on the leeward side of the cooling air.
[0054]
That is, on the substrate 47, the heat radiating plates 48L and 49L are vertically arranged on the right side (windward side), and the heat radiating plates 48R and 49R are vertically arranged on the left side (leeward side). A wind direction plate (insulating wall) 63 is disposed between the heat radiating plate 48L-48R and the heat radiating plate 49L-49R, and the cooling air flow path 57 is divided into two air paths. It is divided into 57a 'and 57b'. Other configurations are the same as those of the first embodiment.
[0055]
According to the third embodiment configured as described above, the following operational effects can be obtained. That is, when induction cooling cooking is performed in the same manner as in the first embodiment and the cooling of the IGBTs 37L to 38R is performed by the cooling fan 50, the inverters 39L having a large rated output are attached to the IGBTs 37L and 38L that generate more heat. By disposing the radiating plates 48L and 49L on the upper side of the cooling air in the duct 51, the cooling efficiency of the IGBTs 37L and 38L can be further increased.
[0056]
FIG. 6 shows a fourth embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted, and only different parts will be described below. In the fourth embodiment, the positions of the heat radiating plates 48R and 49R are replaced with those of the first embodiment. The radiator plates 48L and 48R attached to the positive side IGBTs 37L and 37R of the inverters 39L and 39R are arranged close to each other on the substrate 47, and the radiator plates 49L and 48L are the first embodiment. It is arranged farther away.
[0057]
Short wind direction plates 64 and 65 are disposed at the windward end between the heat sinks 49L-48L and the windward end between the heat sinks 48L-48R, respectively. The wind direction plates 64 and 65 are not formed so as to separate the heat radiating plates 49L to 48L and the heat radiating plates 48L to 48R, as the wind direction plates 55 and 56 in the first embodiment, but as insulating walls. The function of is not provided. Other configurations are the same as those of the first embodiment.
[0058]
According to the fourth embodiment configured as described above, the following operational effects are obtained. That is, since the collectors of the positive side IGBTs 37L and 37R of the inverters 39L and 39R are directly connected to the positive side buses 35L and R, their potentials are always equal. Therefore, there is no danger of a short circuit even if the radiator plates 48L and 48R are arranged close to each other. Therefore, more arrangement space for other components can be ensured. For example, as shown in FIG. 6, the heat radiating plates 49L and 48L can be spaced apart from each other, so that there is no need to provide an insulating wall between them and, of course, between the heat radiating plates 48L and 48R.
[0059]
  The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following modifications or expansions are possible.
  A part of the leeward end of each heat radiating plate may protrude from the duct 51 as shown in the drawings, or all of the heat radiating plate may be accommodated in the duct 51.
  WindThe facing plate or the insulating wall may be provided as necessary.
  An IGBT having an insulation type package may be used as the switching element. In that case, you may share a heat sink with IGBT of positive side and negative side.
  The switching element is not limited to the IGBT, and may be a power transistor or a power MOSFET.
[0060]
In the second embodiment, the left and right arrangements of the heat sinks 60L and 61L, 60R and 61R may be interchanged.
The connection terminals 59R and 59L may be provided at arbitrary positions on the substrate 47.
The inverters 39R and 39L may be configured on independent substrates.
There may be three or more heating coils and inverters.
The present invention is not limited to a built-in type and may be applied to a single cooking device as long as it has a plurality of induction heating cooking units.
[0061]
【The invention's effect】
  Since this invention is as having demonstrated above, there exist the following effects.
  According to the induction heating cooker of the first aspect, since the plurality of heat radiating plates attached to the switching elements constituting the plurality of inverters are arranged inside the duct, the cooling air is blown by one cooling fan. As a result, the switching elements constituting the plurality of inverters can be cooled together, and the cooling structure can be simplified and the cost can be reduced.
  Then, the inverter is configured as a half-bridge type, the heat sink is provided independently for the positive side switching element and the negative side switching element, and the heat sink provided in the negative side switching element is arranged on the windward side inside the duct. If a half-bridge inverter that does not generate interference sound even when driven at the same time is used, the heat sink of the negative switching element with a longer ON period and a large amount of heat generation is placed on the windward side inside the duct. It can be placed and cooled efficiently.
  According to the induction heating cooker of claim 2, the inverter is configured as a half-bridge type, and the heat radiating plate is provided independently for each of the positive side switching element and the negative side switching element, and is provided in the positive side switching element. Since the heat sinks installed in the positive side switching element are always at the same potential when a switching element having a non-insulated package is used, the heat sinks are placed close to each other. Even if they are arranged, there is no problem in insulation, so it is possible to secure an arrangement space for other components.
[0062]
  Claim3According to the induction heating cooker described above, since the wind direction plate that divides the cooling air flow path into a plurality of air paths is provided inside the duct, each inverter is cooled in the plurality of air paths divided by the wind direction plate. It is possible to supply an appropriate air volume.
[0063]
  Claim4According to the described induction heating cooker, an insulating wall that insulates between the plurality of heat radiating plates is provided inside the duct. Therefore, even when a switching element having a non-insulated package with good cooling efficiency is employed, heat dissipation. A short circuit between the switching elements via the plate can be prevented.
[0064]
  Claim5According to the described induction heating cooker, among the plurality of inverters, the heat dissipation plate provided in the inverter having a large rated output is arranged on the windward side inside the duct, so that the switching element with a larger amount of heat generation can be efficiently used. Can be cooled.
[0065]
  Claim6According to the induction heating cooker described above, a plurality of heat sinks are provided for each inverter, and a plurality of inverter-side heat sinks having a large internal rated output of the plurality of inverters are directed to the direction of the cooling air inside the duct. A plurality of inverter-side heat sinks that are arranged in parallel and have a low rated output are arranged in series with respect to the wind direction, so that switching elements that generate a large amount of heat can be efficiently cooled and other components Can be secured.
[0066]
  Claim7According to the described induction heating cooker, a plurality of heat sinks are provided per inverter, and a plurality of heat sinks provided in each inverter are arranged in series with respect to the direction of the cooling air inside the duct. The flow of cooling air can be smoothly guided by the heat sink.
[0069]
  Claim8According to the described induction heating cooker, since the plurality of inverters are configured on one substrate, the configuration is simple, the assemblability is improved, and the cost can be further reduced.
[0070]
  Claim9According to the described induction heating cooker, since the connection terminal for connecting the inverter and the heating coil is arranged on the substrate on which the inverter is configured and located outside the duct, the inverter and the heating Connection to the coil can be made without removing the duct, and workability can be improved.
[Brief description of the drawings]
FIG. 1 is a plan view showing an internal configuration mainly related to a cooling structure of an upper main body with a top plate removed in a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of a portion of the upper main body that covers a cooling fan and a heat sink.
FIG. 3 is a diagram showing an electrical configuration of an induction heating cooking unit.
FIG. 4 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.
FIG. 5 is a view corresponding to FIG. 1 showing a third embodiment of the present invention.
FIG. 6 is a view corresponding to FIG. 1 showing a fourth embodiment of the present invention.
FIG. 7 is a perspective view showing the appearance of a conventional built-in heating cooker.
FIG. 8 is equivalent to FIG.
[Explanation of symbols]
37R, 38R, 37L and 38L are IGBTs (switching elements), 39R and 39L are inverters, 40R and 40L are heating coils, 47 is a substrate, 48R, 49R, 48L and 49L are heat sinks, 50 is a cooling fan, 51 is a duct , 54 are top plates, 55 and 56 are wind direction plates (insulating walls), 57, 57a, 57b, 57c, 57a 'and 57b' are air passages, 59R and 59L are connection terminals, and 60L, 61L, 60R and 61R are heat sinks. Plates 62a and 62b are insulating walls, 63 is a wind direction plate (insulating wall), and 64 and 65 are wind direction plates.

Claims (9)

A top plate on which the cooking container is placed;
A plurality of heating coils arranged below the top plate for induction heating the cooking vessel, and a plurality of inverters for supplying a high-frequency current to the heating coils;
A plurality of heat sinks attached to switching elements constituting the plurality of inverters;
A cooling fan that blows cooling air;
A duct for guiding cooling air blown from the cooling fan,
Arranging the plurality of heat sinks inside the duct ,
The inverter is configured as a half-bridge type,
The heat sink is provided independently for each of the positive side switching element and the negative side switching element,
An induction heating cooker characterized in that a heat radiating plate provided on the negative side switching element is arranged on the windward side inside the duct . A top plate on which the cooking container is placed;
A plurality of heating coils arranged below the top plate for induction heating the cooking vessel, and a plurality of inverters for supplying a high-frequency current to the heating coils;
A plurality of heat sinks attached to switching elements constituting the plurality of inverters;
A cooling fan that blows cooling air;
A duct for guiding cooling air blown from the cooling fan,
Arranging the plurality of heat sinks inside the duct,
The inverter is configured as a half-bridge type,
The heat sink is provided independently for each of the positive side switching element and the negative side switching element,
An induction heating cooker characterized in that the heat dissipating plates provided on the side switching elements are arranged close to each other . The induction heating cooker according to claim 1 or 2, wherein a wind direction plate that divides the air passage of the cooling air into a plurality of air paths is provided inside the duct. The induction heating cooker according to any one of claims 1 to 3, wherein an insulating wall that insulates a plurality of heat sinks is provided inside the duct . The induction heating cooker according to any one of claims 1 to 4, wherein a heat radiating plate provided in an inverter having a large rated output among a plurality of inverters is arranged on the windward side inside the duct . Multiple heat sinks are provided per inverter,
Among the plurality of inverters, a plurality of inverter-side heat sinks with a large rated output are arranged in parallel with the direction of the cooling air inside the duct, and a plurality of inverter-side heat sinks with a small rated output are arranged in the direction of the wind. induction heating cooker according to any one of claims 1 to 4, characterized in that arranged in series against. Multiple heat sinks are provided per inverter,
The induction heating cooker according to any one of claims 1 to 4, wherein a plurality of heat radiating plates provided in each inverter are arranged in series with respect to the direction of the cooling air inside the duct . The induction heating cooker according to any one of claims 1 to 7, wherein a plurality of inverters are configured on a single substrate . 9. The connection terminal for connecting the inverter and the heating coil is arranged on a substrate on which the inverter is configured and at a position located outside the duct. Induction heating cooker.

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