JP2005237183A - Switching power supply unit capable of dissipating heat from transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for dissipating heat with a transformer mounted on a substrate. <P>SOLUTION: A first hole is bored in a portion having the smallest distance between a substrate and the magnetic core of the transformer. A first base projecting from a housing passing through the first hole is installed on the housing and the substrate is fixed on the housing to bring the surfaces of the magnetic core and the first base into close contact with each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a switching power supply device, and more specifically to a heat dissipation means of a transformer.

  As an example of the conventional method, there is a method shown in FIG.

  In FIG. 4, the transformer 1 is fixed to the housing at a position away from the substrate, and the substrate 2 and the transformer 1 are connected by an electric wire 14.

In the case of the conventional system shown in FIG. 4, since the transformer and the substrate on which the switch element of the switching power supply device is mounted are separated from each other, the leakage inductance of the transformer increases and the surge voltage applied to the switch element increases. Noise tends to come out from the wire connecting the two.
Therefore, the present invention provides means for enabling heat dissipation with the transformer mounted on a substrate.

  In the first aspect of the present invention, a first hole is formed in a portion where the distance between the substrate of the substrate and the magnetic core of the transformer is the shortest, and a first base protruding from the casing penetrating the first hole is provided in the casing. Then, by fixing the substrate to the housing, the surfaces of the magnetic core and the first table are brought into close contact with each other.

  3. The invention according to claim 2, wherein a second hole is formed on both sides of the first hole of the board, and the projecting second base with a screw hole through which the board can be fixed with a screw through the second hole. The heat sink was placed on the surface of the magnetic core opposite to the surface in contact with the first base, and the heat sink was fixed to the second base with a screw passing through the second hole of the substrate.

  In the invention according to claim 3, the heat sink constitutes a part of the casing.

  Although the switching power supply device is miniaturized year by year, the loss caused by the transformer itself is not so much reduced. Therefore, heat dissipation of the transformer becomes a problem when the transformer is miniaturized. Especially in an environment where forced air cooling is not possible, there is an increasing need to solve the heat dissipation of the transformer. The present invention can suppress the increase in the temperature of the transformer while keeping the wiring between the transformer and the switch element optimal, thereby contributing to the miniaturization of the switching power supply in the future.

Since the heat generated by the transformer is conducted from the magnetic core through the casing, the temperature rise of the transformer itself caused by the loss of the transformer is reduced.
The transformer and the switching element can be mounted on the same substrate. As a result, the wiring between the transformer and the switch element is shortened, so that the characteristics of the switching power supply are improved.

FIG. 1 is a view showing an embodiment of the present invention.
FIG. 1 shows a view of a transformer and a switch element viewed from directly above and a cross-sectional view thereof. The heat of the transformer 1 is conducted through the first base 3a and radiated from the housing 3 into the air.

  FIG. 2 is a sectional view showing an embodiment of the second aspect of the present invention. The heat sink 4 is fixed to the housing 3 with screws 5 and screws 6. In FIG. 2, the heat of the transformer 1 is conducted through the first base 3 a and the heat radiating plate 4 and is radiated from the housing 3 and the heat radiating plate 4 to the air.

  FIG. 3 is a sectional view showing an embodiment of the invention as set forth in claim 3. Screws 5 and 6 for fixing the heat radiating plate 4 are fixed to extension screws 5 a and 6 a, and the extension screws 5 a and 6 a also serve to fix the substrate 2 to the housing 3. In FIG. 3, the housing 3 is a sealed case, and the heat radiating plate 4 constitutes a part of the housing as a lid of the housing 3. The heat of the transformer is conducted through the first base 3a and the heat radiating plate 4 and radiated from the housing 3 into the air.

  It can be applied to a power supply that cannot be forced-air cooled, a power supply stored in a sealed case, or a power supply device placed in outer space.

  It is a figure which shows the Example of invention of Claim 1.   It is a figure which shows the Example of invention of Claim 2.   It is a figure which shows the Example of invention of Claim 3.   It is a figure which shows one example of the conventional system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transformer 1a Magnetic core of a transformer 2 Board | substrate 3 Case 3a 1st stand 3b, 3c 2nd stand 4 Heat sink 5,6 Screw 5a, 6a Extension screw 7 Switch element 8, 9, 10, 11, 12, 13 Screw 14 Wire connecting the transformer and substrate

Claims (3)

  In a switching power supply apparatus including a substrate, a transformer having a magnetic core mounted on a component surface of the substrate, and a casing for fixing the substrate, the substrate is located at a position where the distance between the substrate and the magnetic core of the transformer is the closest. There is a first hole, and the housing has a protruding first base that penetrates the first hole, and the transformer core and the first base when the substrate is fixed to the housing. Switching power supply device characterized in that the surfaces of each other are in contact with each other.   The substrate has a second hole through which the screw is passed on both sides of the first hole, and the housing has a protruding second base with a screw hole through which the substrate can be fixed with the screw through the second hole. The heat sink is in contact with the surface of the transformer core opposite to the surface in contact with the first base, and the heat sink is fixed to the second base through the second hole with a screw. The switching power supply device according to claim 1.   The switching power supply device according to claim 3, wherein the heat radiating plate constitutes a part of the housing.

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