JP4474762B2 - Cooling device for electric elements - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric element cooling apparatus that cools electric elements on a circuit board through cooling fins in a ventilation duct.
[0002]
[Prior art]
3 and 4 show a cooling device of this type in an electromagnetic cooker, FIG. 3 is a schematic longitudinal sectional view of the main body of the electromagnetic cooker, and FIG. 4 is a perspective view of the cooling device shown together with a circuit board. As is well known, an electromagnetic cooker induces an eddy current at the bottom of a pan made of a magnetic material to generate heat and cooks food in the pan. In FIG. 3, 1 is on the top plate 2. An induction coil for inducing an eddy current in a magnetic pot (not shown) placed thereon is a circuit board on which a power supply circuit and a control circuit for supplying a high frequency current to the induction coil 1 are mounted. Various heat-generating electric elements are mounted on the circuit board 3, but the switching transistor (IGBT) 4, which is a main element of the high-frequency power supply, generates a particularly large amount of heat and is cooled by the cooling fins 5 made of aluminum die casting. It is like that. The cooling fin 5 is a rectangular parallelepiped with an open top surface, and is fixed to the circuit board 3 with screws through a spacing piece. The bottom surface of the cooling fin 5 is in thermal contact with the top surface of the switching transistor 4 mounted on the circuit board 3. ing.
[0003]
In FIG. 4, the cooling fin 5 is covered with a ventilation duct 6 having a gate-shaped cross section made of heat-resistant resin with open front and rear ends, and a cooling fan 7 is connected to one end (rear end) thereof. The cooling fan 7 is supported by an impeller 7a (FIG. 3) in a rectangular frame corresponding to the ventilation duct 6, and is viewed from the direction of arrow A in FIG. 4, that is, from the front side of the ventilation duct 6 (left side in FIG. 3). Rotate in the direction and blow cooling air toward the front (arrow B direction).
The cooling fin 5 is cooled by the cooling air, and the switching transistor 4 in contact with the bottom surface is cooled. Various electric elements 8 other than the switching transistor 4 are mounted on the circuit board 3, and they are arranged around the ventilation duct 6, but these electric elements 8 also generate heat. Therefore, conventionally, for example, a slit 9 is provided in the ventilation duct 6 so that a part of the cooling air from the cooling fan 7 is appropriately leaked out of the duct as indicated by a curved arrow C, so that the electric element 8 in the vicinity of the ventilation duct is provided. Are cooled at the same time.
[0004]
[Problems to be solved by the invention]
Conventionally, the electric element 8 in the vicinity of the ventilation duct is cooled by the cooling air leaked from the ventilation duct 6. However, since this leakage cooling air diffuses on the circuit board, the cooling efficiency is poor and a sufficient cooling effect is obtained. There wasn't. Further, when the leakage amount of the cooling air is increased as a countermeasure, there is a problem that the air amount with respect to the cooling fin 5 is insufficient.
The subject of this invention is improving the cooling performance of the electric element of the periphery, without producing the trouble in cooling of the electric element cooled via a cooling fin.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a cooling fin whose bottom surface is in thermal contact with an electrical element on a circuit board, a ventilation duct covering the cooling fin, and a cooling coupled to one end of the ventilation duct. In the cooling device for an electric element that cools the electric element through the cooling fin by cooling air that is passed from one end of the ventilation duct to the other end by the cooling fan, the lateral width of the ventilation duct a margin to the cooling fins in the space, the with the electrical elements on the cooling the circuit board other than the electric element fins is contacted intended to be housed in the spare area of the ventilation duct In the lateral width space of the ventilation duct, the cooling fins may be arranged so as to be shifted to the side where the impeller of the cooling fan rotates from top to bottom.
[0006]
As shown in FIG. 5, the wind sent forward from the cooling fan 7 usually has a speed component (arrow B) in the rotational direction (arrow A) of the impeller 7a and swirls in the rotational direction as a whole. . Accordingly, on the side where the impeller of the cooling fan rotates from the top to the bottom (the right side in FIG. 5), the cooling air also turns so as to face from the top to the bottom. By cooling the cooling fins supported on the circuit board by blowing cooling air so as to pour down from the upper surface, the cooling effect is enhanced, and the cooling effect of the electric elements by accommodating other electric elements in the extra space Can be reduced.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a cooling device similar to that shown in the conventional example will be described with reference to FIGS. In FIG. 1, the difference from the conventional one is that the ventilation duct 6 is configured to be wide so that the lateral width space has a margin with respect to the cooling fin 5, and is conventionally arranged in the margin space 10 near the outside of the cooling duct 6. A part or all of the electric element 8 that has been used is accommodated. As shown in FIG. 2, the cooling fin 5 is configured such that the impeller 7 a of the cooling fan 7 that rotates clockwise (in the direction of arrow A) as viewed from the front rotates in the horizontal space of the ventilation duct 6 from top to bottom. The marginal space 10 is provided on the left side.
[0008]
In such a cooling device, most of the cooling air blown forward from the cooling fan 7 (in the direction of arrow B in FIG. 1) flows through the cooling fins 5 and cools the electric element 4 with which the cooling fins 5 contact. A part thereof flows through the marginal space 10 and directly cools the electric element 8. In such a configuration, since all the cooling air that does not pass through the cooling fins 5 is concentrated in the marginal space 10 and applied to the electric element 8, the cooling air that diffuses without being used for cooling is reduced, and the cooling as a whole is performed. Increases efficiency. Further, in FIG. 2, the cooling fin 5 that is biased toward the side where the impeller 5a performs the rotational movement from the top to the bottom, as indicated by the arrow C, receives cooling air so as to flow down from the upper surface thereof. The cooling efficiency is higher than when 5 is arranged at the center of the right and left of the ventilation duct 6, and as a result, a decrease in the cooling effect due to a part of the cooling air flowing into the marginal space is reduced. In addition, although the example in an electromagnetic cooker was shown in illustrated embodiment, application of this invention is not restricted to this.
[0009]
【The invention's effect】
As described above, according to the present invention, it is possible to effectively use the cooling air of the cooling fan that passes through the cooling fins and efficiently cool not only the electric elements that contact the cooling fins but also the peripheral electric elements.
[Brief description of the drawings]
FIG. 1 is a perspective view of an electric element cooling apparatus according to an embodiment of the present invention.
FIG. 2 is a front view of FIG.
FIG. 3 is a schematic longitudinal sectional view of an electromagnetic cooker equipped with a conventional electric element cooling device.
4 is a perspective view of a cooling device for the electric element in FIG. 3. FIG.
FIG. 5 is a front view illustrating a wind direction component of a cooling fan.
[Explanation of symbols]
3 Circuit board 4 Electrical element 5 Cooling fin 6 Duct 7 Cooling fan 7a Impeller 8 Electrical element 10 Spacious space

Claims (1)

A cooling fin whose bottom surface is in heat transfer contact with an electric element on the circuit board, a ventilation duct covering the cooling fin, and a cooling fan connected to one end of the ventilation duct, and the ventilation duct is formed by the cooling fan. In the cooling device for an electric element that cools the electric element through the cooling fin by cooling air that is ventilated from one end to the other end,
The lateral space of the ventilation duct has a margin with respect to the cooling fins, and electrical elements on the circuit board other than the electrical elements that are in contact with the cooling fins are accommodated in the marginal space of the ventilation duct , and The cooling device for an electric element according to claim 1 , wherein the cooling fins are arranged close to a side where the impeller of the cooling fan rotates from top to bottom in a lateral width space of the ventilation duct .

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