JP2007234623A - Electromagnetic cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic cooker capable of very effectively cooling by a fan having reduced rotational frequency and having a quiet blower. <P>SOLUTION: The electromagnetic cooker comprises a heating coil; a top plate arranged under the heating coil and having an exhaust port; a pair of heat sinks having a plurality of cooling fins and fixed with circuit components, and a cooling fan. The pair of heat sinks are arranged in such a manner that the tip surfaces of the cooling fins face each other and are spaced from each other through a gap to form a cooling chamber. Air from the cooling fans flows to the exhaust port through the cooling chamber. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electromagnetic cooker, and more particularly to an electromagnetic cooker having an electric circuit component for supplying a large current to an electromagnetic induction heating coil.

  An electromagnetic cooker is highly safe because it uses a heating coil (electromagnetic induction coil) to form an eddy current at the bottom of the pan without using a flame, thereby heating the pan itself. Moreover, the electromagnetic cooker is a very excellent cooking utensil because it has high thermal efficiency and can save the time and cost required for cooking. For this reason, electromagnetic cookers are becoming more and more popular in recent years, with momentum surpassing conventional gas cookers.

  This electromagnetic cooker generally includes an induction heating type heating coil and various electronic components for supplying a large current to the controllable heating coil. These heating coils and electronic components generally need to be cooled using a blower having a cooling fan (propeller fan) in order to ensure their normal operation. Some of these electronic components generate extremely high heat during operation, so that they must be sufficiently cooled (for example, IGBTs and diode bridges), and those that generate a relatively low amount of heat (for example, capacitors). (Hereinafter, for the sake of convenience, such a part having a high calorific value is referred to as a high heat generating part, and a relatively low part is referred to as a low heat generating part. Usually, a heat sink is fixed to such a high heat-generating component, and it is devised to increase the cooling effect by increasing the cooling area.

  In addition, the cooling effect can be increased by increasing the rotation speed of the cooling fan of the blower. However, as the rotational speed increases, the noise generated by the cooling fan increases remarkably, giving the user discomfort. In recent years, the electric current to be supplied to the heating coil has been increasing more and more, especially because of the popularity of electromagnetic cookers with larger cooking power. In such a situation, when a larger amount of current is supplied to the heating coil, it is strongly desired to develop a technique for cooling the high heat-generating component more efficiently without causing discomfort to the user.

  Specifically, the conventional electromagnetic cooker includes a cooling path that is separated from each other with respect to an upper unit including a heating coil and a lower unit including a drive circuit unit, and is a first for cooling the heating coil. A cooling fan motor is disposed in the cooling path of the upper unit, and a second cooling fan motor that cools the drive circuit unit is disposed in the cooling path of the lower unit (see, for example, Patent Document 1).

  In addition, another conventional electromagnetic cooker has an intake-exhaust fan and an exhaust-exhaust fan arranged in a substantially sealed main body to secure an intake / exhaust path and efficiently cool equipment in the main body. (For example, refer to Patent Document 2).

JP-A-3-114178 JP-A-11-354264

  However, according to Patent Document 1, by separating the cooling path from the upper unit and the lower unit, it is possible to prevent the exhaust of the lower unit from entering the intake air of the upper unit and improve the cooling efficiency inside the upper unit. Although both the high heat-generating component and the low heat-generating component constituting the drive circuit unit are similarly cooled in the lower unit, in order to cool the high heat-generating component more efficiently, it is still necessary to It was necessary to increase the number of rotations of the cooling fan motor No. 2, and the noise caused by the motor could not be reduced.

  According to Patent Document 2, the main body is substantially sealed, and an intake-only fan and an exhaust-only fan are provided to secure an intake / exhaust path and improve cooling efficiency in the main body. Since these two fans are arranged at arbitrary positions in the main body, the high heat-generating parts and the low heat-generating parts are cooled in the same manner. The amount must be increased, and as in Patent Document 1, noise due to an increase in the number of rotations of the fan cannot be reduced.

  Therefore, the present invention has been made to solve such problems, and while suppressing the number of rotations of the cooling fan of the blower as much as possible and substantially reducing the noise generated thereby, it is possible to further increase the efficiency of high heat-generating parts such as IGBTs. It aims at realizing the electromagnetic cooker which can be cooled automatically.

  An electromagnetic cooker according to the present invention includes a heating coil, a top plate disposed below the heating coil, having an exhaust port, a plurality of cooling fins, and a pair of heat sinks to which circuit components are fixed, cooling The pair of heat sinks are arranged so that the front end surfaces of the cooling fins face each other and are spaced apart via a gap, forming the cooling chamber, and the air from the cooling fan is After flowing through the cooling chamber, it flows into the exhaust port.

  ADVANTAGE OF THE INVENTION According to this invention, it can cool very efficiently with a fan with few rotation speeds, and can implement | achieve the electromagnetic cooker which has a quieter air blower.

  Embodiments of an electromagnetic cooker according to the present invention will be described below with reference to the accompanying drawings. In the description of each embodiment, terms indicating directions (for example, “horizontal direction” and “vertical direction”, etc.) are used as appropriate for ease of understanding. The terminology does not limit the invention.

Embodiment 1 FIG.
In general, an electromagnetic cooker is roughly classified into a stationary type that is installed on a table and used, and a built-in type that is incorporated into a system kitchen and used, but the basic structure is the same in both. Here, the first embodiment of the present invention will be described in detail below with reference to the stationary electromagnetic cooker shown in FIGS. In FIG. 1, which is a perspective view of the electromagnetic cooker according to Embodiment 1 of the present invention, the electromagnetic cooker 1 generally includes a top plate 3 formed of glass or the like, and two heating coils 4 disposed below the top plate 3. A grill part 5, a dial-type thermal power adjustment part 6, a display part 7, an intake opening 8 and an exhaust opening 9 are provided. Moreover, this electromagnetic cooker 1 has the housing | casing 10 shown with a broken line inside.

  2 is a plan view of the housing 10 after removing the top plate 3 and the heating coil 4 of the electromagnetic cooker 1 of FIG. The internal structure of the housing 10 is illustrated by being removed (the top plate of an air guide duct described later is also illustrated). In FIG. 2, the housing 10 has one air inlet 14 at a position adjacent to the air intake opening 8, and a plurality of micro exhaust ports 16 on the top plate 12 of the housing at a position corresponding to the lower part of the heating coil 4. Have. Although not shown in detail, the intake port 14 and the minute exhaust port 16 are in fluid communication with the intake opening 8 and the exhaust opening 9, respectively. Thus, an air communication path (air passage) is formed by the intake opening 8, the intake opening 8 of the housing 10, the plurality of minute exhaust ports 16, and the exhaust opening 9.

  3 is a cross-sectional view taken along line III-III in FIG. As shown in FIG. 2 and FIG. 3, the electromagnetic cooker 1 of the present invention roughly includes a ventilation fan (first fan) 20 for feeding air into the entire housing 10 and two heating coils 4. And an electric circuit section 30 for supplying a large current in a controllable manner. The ventilation blower 20 has a ventilation fan 22 and is disposed adjacent to the air inlet 14. The electric circuit unit 30 is accommodated in the housing 10 and is preferably disposed immediately below the heating coil 4 closer to the intake opening 8, but immediately below the heating coil 4 adjacent to the exhaust opening 9. Or it is also possible to arrange | position directly under both the heating coils 4. FIG.

  The electric circuit unit 30 includes a circuit board 32, a plurality of low heat generation components (first circuit components) 34 having a relatively small heat generation amount during operation, such as a capacitor mounted thereon, and a heat generation amount during operation, such as an IGBT. A relatively large plurality of high heat generating components (second circuit components) 36 and a cooling blower (second blower) 40 for cooling only the high heat generating components 36.

  As is clear from the enlarged view of FIG. 4, the high heat-generating component 36 is fixed to a pair of heat sinks 38a and 38b having a plurality of cooling fins 39 extending in the horizontal direction in order to increase the cooling effect (cooling area). (Four heat-generating components 36 are fixed to each of the heat sinks 38a and 38b). The heat sinks 38a and 38b have substantially the same shape, and are arranged so that the front end surfaces of the respective cooling fins 39 face each other and are separated by a minute gap. Therefore, a plurality of spaces 50 (cooling chambers) are formed between the cooling fins 39 of the heat sinks 38a and 38b. In addition, since each heat sink 38a, 38b has a mutually different electric potential, it is preferable to provide an insulating member (not shown) between them.

  The cooling fan 40 includes a cooling fan 42 and an air guide duct 44 that accommodates the cooling fan 42 and efficiently guides the airflow formed thereby to the heat sinks 38a and 38b. Although the air guide duct 44 and the heat sinks 38a and 38b are close to each other, the cooling fan 42 and the heat sinks 38a and 38b are about half the length of the air guide duct 44 in order to increase the static pressure in the air guide duct 44. Arranged at a distance.

  Next, operation | movement of the electromagnetic cooker 1 by 1st Embodiment is demonstrated below. When the electromagnetic cooker 1 is used, the heating coil 4, the low heat generating component 34, and the high heat generating component 36 generate heat, and the ventilation fan 20 operates to cool them. The ventilation fan 20 can increase the static pressure in the housing 10 to be higher than the atmospheric pressure. Thus, the air flow (airflow) taken from the intake opening 8 from the ventilation blower 20 first cools the low heat generating component 34 and the high heat generating component 36, and the air flow exhausted through the plurality of micro exhaust ports 16. Collides with the heating coil 4 and cools it. The airflow that has cooled the heating coil 4 is exhausted from the exhaust opening 9.

  On the other hand, the cooling fan 40 operates in a state where the ventilation fan 20 is operated, and can accelerate the flow velocity of the air flow generated by the ventilation fan 20. That is, the cooling blower 40 can form a static pressure in the air guide duct 44 that is higher than the static pressure in the housing 10. Thus, since the air flow blown out from the air guide duct 44 has a higher flow velocity, the high heat generating component 36 can be cooled more efficiently than the air flow formed only by the ventilation fan 20.

  As described above, in the electromagnetic cooker 1 of the present invention, the cooling fan 40 that separately (intensively) cools only the components that need to be sufficiently cooled is separately provided. The number can be suppressed as much as possible. Further, since the cooling fan 40 accelerates the flow velocity of the air flow generated by the ventilation fan 20, the air flow having a flow velocity that can sufficiently cool the high heat generating component 36 without increasing the number of revolutions of the cooling fan 42. Can be realized. Actually, the air flow rate formed by the cooling fan 40 may be about 1/3 to 1/2 of the air flow rate formed by the ventilation fan 20, and the dimension (fan diameter) of the cooling fan 40 is It has been confirmed that about 1/2 to 2/3 of the size of the ventilation fan 20 is sufficient. Accordingly, the noise due to the rotation of the cooling fan 42 can be considerably smaller than that of the ventilation fan 22.

  Furthermore, as shown in FIGS. 2 and 3, the direction of the air flow generated by the ventilation fan 20 and the cooling fan 40 is substantially the same, so that the cooling air direction is different from the case where the direction of the formed air flow is different. The blower 40 can obtain an airflow with a faster flow rate. In other words, the cooling blower 40 can supply an airflow having a predetermined airflow velocity with a sufficiently high cooling effect at a lower rotational speed. Thus, the rotational speed of the fans 22 and 42 of the ventilation fan 20 and the cooling fan 40 can be reduced, and the rotational noise can be substantially reduced.

  In addition, as shown in FIG. 4, the cooling fins 39 of the heat sinks 38a and 38b according to the first embodiment form the cooling chamber 50 and are blown out from the air guide duct 44 adjacent to the heat sinks 38a and 38b. Since all the air flow is substantially guided into the cooling chamber 50, the heat sinks 38a and 38b can be cooled more efficiently. That is, according to the first embodiment, the accelerated air flow is guided into the cooling chamber 50, and therefore, the high heat generating component 36 can be cooled very efficiently by the cooling fan 42 having a small number of rotations. Thus, the electromagnetic cooker 1 having the quieter cooling fan 40 can be realized.

  In the above-described embodiment, the cooling chamber 50 is formed between the pair of heat sinks 38a and 38b arranged to face each other and to be separated from each other. Alternatively, as shown in FIG. 5, the high heat generating component 36 is mounted in parallel to the circuit board 32, and one heat sink 38 having a plurality of cooling fins 39 extending in the vertical direction is provided on the high heat generating component 36. Further, the cooling hood 52 is disposed so as to cover the heat sink 38. At this time, the cooling chamber 50 is formed between the cooling fins 39 and the cooling hood 52. The cooling chamber 50 obtained in this way is arranged in the vicinity of the air guide duct 44 as in the first embodiment, and substantially all the air flow blown out from the air guide duct 44 enters the cooling chamber 50. Since it is guided, the heat sinks 38a and 38b can be cooled more efficiently. Thereby, the electromagnetic cooker 1 having the quieter cooling fan 40 can be realized.

  Furthermore, in the above embodiment, the cooling fan 40 is disposed adjacent to the upstream side of the airflow of the heat sink 38, but may be disposed adjacent to the downstream side of the airflow. However, the cooling blower disposed on the downstream side of the airflow sucks the airflow from the plurality of cooling chambers 50, but the airflow is blown out from the cooling chamber 50 and naturally does not blow out from the cooling fins 39. The flow velocity of the airflow to be sucked has variations due to the position. Therefore, when the cooling fan 42 rotates in a direction crossing the variable airflow, a larger rotational noise is generated. Therefore, the cooling fan 40 is preferably disposed adjacent to the airflow upstream side of the heat sink 38.

Embodiment 2. FIG.
The second embodiment of the present invention will be described in detail below with reference to FIGS. The electromagnetic cooker 2 according to the second embodiment has the same configuration as that of the electromagnetic cooker 1 of the first embodiment except for the arrangement configuration of the electric circuit unit 30, and thus description of overlapping contents is omitted. To do.

  According to the electromagnetic cooker 2 according to the second embodiment, as shown in FIG. 6, the cooling fan 40 is disposed immediately downstream of the ventilation fan 20, and the air flow formed by the ventilation fan 20 is Accelerate the flow rate. Furthermore, the direction of the airflow generated by each of the blowers 20 and 40 is substantially the same as in the first embodiment.

  Further, in the electric circuit section 30 of the second embodiment, the high heat generating component 36 and the pair of heat sinks 38a and 38b are arranged on the downstream side of the air flow of the cooling blower 40 and at the approximate center of the circuit board 32, The low heat generating components 34 are disposed on both sides of the circuit board 32 with the high heat generating component 36 interposed therebetween.

  In the electromagnetic cooker 2 configured in this way, the airflow generated by the ventilation fan 20 and the cooling fan 40 cools the low heat-generating component 34 and the high heat-generating component 36, and a part of the air is heated via the micro exhaust port 16. Although the coil 4 is cooled, a part of the coil 4 collides with the end wall 18 of the housing 10 and flows backward to the vicinity of the intake port 14 to form a so-called circulation flow. Since the circulating flow is an air flow after cooling the low heat generating component 34 and the high heat generating component 36, the temperature thereof is higher than the air flow taken from the atmosphere. Therefore, the air duct 44 of the cooling fan 40 according to the second embodiment is longer than the air duct according to the first embodiment, and is substantially ventilated from the high heat generating component 36 (heat sink 38). Designed to extend to 20. As a result, the heat sink 38 can be efficiently cooled without the hot circulating flow being taken into the air guide duct 44. Thus, the rotational speed of the cooling fan 42 of the cooling blower 40 can be reduced, and the noise caused by the cooling fan 42 can be reduced.

Embodiment 3 FIG.
A third embodiment according to the present invention will be described in detail below with reference to FIG. The electromagnetic cooking device according to the third embodiment is the electromagnetic cooking according to the first and second embodiments except that the rotation direction of the cooling fan 42 of the cooling fan 40 and the ventilation fan 22 of the ventilation fan 20 are different. Since the configuration is the same as that of the containers 1 and 2, the description of the overlapping contents is omitted.

  As described above, according to the electromagnetic cookers 1 and 2 of the first and second embodiments, the cooling hood 22 of the ventilation fan 20 and the cooling fan 42 of the cooling fan 40 rotate in the same direction. Was designed to. However, according to the electromagnetic cooking device by 3rd Embodiment, as shown in FIG. 8, the rotation direction of the cooling hood 22 and the cooling fan 42 differs mutually.

In general, the airflow formed by the propeller fan has an airflow vector composed of an airflow direction component and a circumferential direction component orthogonal thereto when viewed microscopically. When two propeller fans that rotate in the same direction are arranged in series in the airflow direction, the airflow formed by the upstream fan collides with the downstream fan, giving it kinetic energy, rather, the flow velocity is May be smaller. However, when the upstream fan and the downstream fan rotate in different directions, the airflow vectors of the airflow generated by the respective fans are different from each other (that is, the orthogonal direction component is opposite), so the airflow of the upstream fan Is not weakened by the downstream fan.
In the third embodiment, the rotation directions of the cooling fan 22 and the cooling fan 42 are designed to be different from each other in order to prevent the flow velocity of the air flow generated by the cooling fan 22 from being decelerated by the cooling fan 42. ing. In this way, when viewed macroscopically, the static pressure in the air guide duct 44 can be substantially increased as compared with the static pressure in the housing 10, and the heat sink 38 and thus the high heat generating component 36 can be cooled more efficiently. be able to.

  In the above embodiment, the cooling hood 22 of the ventilation fan 20 and the cooling fan 42 of the cooling fan 40 have been described as propeller fans. However, as will be readily understood by those skilled in the art, Any type of fan, such as a sirocco fan or a turbo fan, can be used to construct the electromagnetic cooker of the present invention.

Embodiment 4 FIG.
The fourth embodiment according to the present invention will be described below in detail with reference to FIGS. The electromagnetic cooking device according to the fourth embodiment is the electromagnetic cooking according to the first to third embodiments except that at least one air guide plate is further provided between the ventilation fan 20 and the cooling fan 40. Since it has the same configuration as the container, the description of the overlapping contents is omitted.

  Referring to FIG. 9, as described above, the electromagnetic cooker 51 according to the fourth embodiment includes at least one air guide plate 46 between the ventilation fan 20 and the cooling fan 40. The main surface of the air guide plate 46 is disposed so as to be substantially parallel to the direction of the airflow formed by the ventilation fan 20. Thereby, when viewed microscopically, the airflow direction component of the airflow vector is not disturbed, and the circumferential direction component collides with the air guide plate 46 and is rectified. Therefore, when viewed macroscopically, the static pressure on the upstream side of the cooling fan 40 can be substantially increased without the airflow flowing from the ventilation fan 20 to the cooling fan 40 being diffused in the circumferential direction. That is, even when the cooling blower 40 having the same cooling capacity is used, the static pressure on the upstream side of the cooling blower 40 is increased by using the air guide plate 46 and flows into the heat sink 38. The air flow rate can be increased. In this way, the heat sink 38 and thus the high heat generating component 36 can be cooled more efficiently.

  As described above, the air guide plate 46 does not inhibit the air flow direction component of the air flow vector, and rectifies the circumferential direction component so as to substantially increase the static pressure on the upstream side of the cooling fan 40. , Can have any shape. For example, as illustrated in FIG. 9 and FIG. 10A, two air guide plates 46 assembled so as to be orthogonal to each other may be disposed on the downstream side of the ventilation fan 20. At this time, one air guide plate 46a is arranged in parallel to the circuit board 32 and the other air guide plate 46b is perpendicular to the circuit board 32. FIG. As described above, the air guide plates 46 a and 46 b may be arranged in a direction unrelated to the main surface of the circuit board 32. That is, the normal direction of the main surface of the air guide plates 46a and 46b is arbitrary.

  Further, the two air guide plates 46 shown in FIGS. 10 (a) and 10 (b) are assembled so that their main surfaces are orthogonal to each other, but are assembled so as to form an arbitrary angle other than a right angle. (Not shown). Furthermore, as shown in FIG. 10C, the plurality of air guide plates 46 may be configured in a lattice shape. At this time, the normal direction of the main surface of each air guide plate 46 is also arbitrary.

  As described above, the static pressure on the upstream side of the cooling fan 40 can be substantially increased by using the at least one air guide plate 46, and the heat sink 38 and the high heat generating component 36 can be cooled more efficiently. In addition, the rotational speed of the cooling fan 42 can be reduced, and the rotational noise of the fan can be significantly reduced.

FIG. 1 is a perspective view showing a stationary electromagnetic cooker according to the first embodiment of the present invention. FIG. 2 is a partially broken plan view of the electromagnetic cooker shown in FIG. 1 after removing the top plate and a part of the top plate of the housing. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a perspective view showing the heat sink, the cooling chamber, and the cooling blower shown in FIG. FIG. 5 is a perspective view showing an alternative heat sink, cooling chamber, and cooling fan. FIG. 6 is a partially broken plan view similar to FIG. 2 of the electromagnetic cooking device according to the second embodiment. FIG. 7 is a cross-sectional view similar to FIG. FIG. 8 is an enlarged sectional view showing the rotation direction of the cooling hood of the ventilation fan and the cooling fan of the cooling fan according to the third embodiment. FIG. 9 is a cross-sectional view similar to FIG. 3 of an electromagnetic cooker according to the fourth embodiment. FIG. 10 is an enlarged view of the air guide plate and the cooling fan of the ventilation fan.

Explanation of symbols

1, 2, 51 Electromagnetic cooker, 3 Top plate, 4 Heating coil, 5 Grill part, 6 Dial type thermal power adjustment part, 7 Display part, 8 Intake opening part, 9 Exhaust opening part, 10 Housing, 12 Top plate 14 Intake port, 16 Micro exhaust port, 18 End wall, 20 Ventilation fan (first fan), 22 Ventilation fan, 30 Electrical circuit section, 32 Circuit board, 34 Low heat generating component (first circuit component) 36 High heat generation Component (second circuit component), 38 heat sink, 39 cooling fin, 40 cooling fan (second fan), 42 cooling fan, 44 air guide duct, 46 air guide plate, 50 cooling chamber.

Claims (7)

A heating coil;
A top plate disposed below the heating coil and having an exhaust port;
A pair of heat sinks having a plurality of cooling fins to which circuit components are fixed;
With a cooling fan,
The pair of heat sinks are disposed so that the front end surfaces of the cooling fins face each other and are separated from each other through a gap, forming the cooling chamber,
The electromagnetic cooker according to claim 1, wherein air from the cooling fan flows through the cooling chamber and then flows into the exhaust port. The exhaust port is located below the heating coil,
The electromagnetic cooker according to claim 1, wherein the air flow exhausted through the exhaust port collides with the heating coil. A circuit board for mounting circuit components is provided,
The electromagnetic cooking device according to claim 1, wherein the cooling fins are arranged in parallel to the circuit board. The circuit component includes a first circuit component and a second circuit component that generates more heat than the first circuit component,
The electromagnetic cooker according to claim 1, wherein the second circuit component is fixed to the heat sink.   The electromagnetic cooker according to claim 1, wherein air that has flowed through the cooling chamber and air that has flowed outside the cooling chamber flow to an exhaust port.   The electromagnetic cooker according to claim 1, further comprising an air guide duct for guiding an airflow formed by the cooling fan to the cooling chamber.   The electromagnetic cooker according to claim 1, wherein an insulating member is provided between the pair of heat sinks.

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