JP2002134971A - Switching power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a switching power supply which can reduce the influence of the heat radiating from the frame of an electronic component, arranged near the frame or a side plate of a case, and the case. SOLUTION: The metallic frame 1 or case is used as a heat radiating member. Notches 16 and 17 of large size are provided at positions of the frame 1 or the side plate 1c of the case near the electronic components 9A and 11A of relatively large size. The notches 16 and 17 are lower in temperature than the frame 1, so the quantity of heat radiation and convection to the electronic components 16 and 17 are reduced to suppress temperature rise of the electronic components 9A and 11A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching power supply using a metal U-shaped or L-shaped frame or case as a heat radiating member, and more particularly to a U-shaped or L-shaped electronic component mounted on a printed circuit board. The present invention relates to a structure for preventing the influence of heat from a side plate of a case.

[0002]

2. Description of the Related Art A switching power supply has heat-generating components such as diodes and transistors. By attaching such a heat-generating component to a frame or case made of metal such as aluminum, heat is released to the frame or case, and measures are taken to suppress a rise in temperature.

[0003]

However, in order to reduce the size of the switching power supply, at least a part of winding components such as a transformer and a choke coil and electronic components such as a capacitor are provided on side plates of the frame and the case. It has to be placed close.

For this reason, the electronic components arranged close to each other are:
There is a problem that the heat-generating component is affected by heat from radiation from the frame or the case whose temperature has risen, and has a bad effect of shortening the service life and decreasing reliability.

SUMMARY OF THE INVENTION In view of the above problems, the present invention can reduce the effects of heat radiation and convection from a frame or a case of an electronic component disposed close to a side plate of a frame or a case, thereby extending the life and improving reliability. It is an object of the present invention to provide a switching power supply having a configuration capable of improving the size and reducing the size.

[0006]

A switching power supply according to claim 1 is a switching power supply using a metal U-shaped or L-shaped frame or case as a heat radiating member, and a side plate portion of the frame or case. A cutout having a size close to or larger than the projected area of the electronic component on the side plate portion is provided at a position close to the relatively large electronic component.

As described above, by providing a notch composed of a large opening or a notch at a position facing the electronic component on the side plate portion of the frame or the case, the temperature of the notch becomes low, and the electronic components arranged close to each other are provided. Radiation (fluctuation) and convection of heat from the side plate portion to the component are reduced, and the amount of heat received by the electronic component is reduced, so that the life of the electronic component can be extended and the reliability can be improved. In addition, by providing the notch, if the notch is not covered with a closed structure by a cover,
The ventilation to the electronic component is improved, and the temperature of the electronic component can be reduced from this aspect. Further, since the side plate portion can be arranged close to the electronic component, the size of the switching power supply can be reduced.

According to a second aspect of the present invention, there is provided a switching power supply.
, Wherein the electronic component is any one of a capacitor, a resistor, and a winding component.

In practicing the present invention, semiconductor components (heat generating components) such as diodes and transistors mounted on a printed circuit board may be mounted on the printed circuit board in addition to heat generating components such as semiconductors mounted on a frame or a case. If the semiconductor component is placed close to the side plate,
Since the temperature of the notch is low, a rise in temperature is suppressed. Similarly, in the case of a resistor, such as a capacitor, a resistor for preventing an inrush current or a resistor for an absorber, or a winding component, the temperature can be reduced.

A switching power supply according to a third aspect of the present invention is a switching power supply that uses a metal U-shaped or L-shaped frame or case as a heat radiating member, and is close to a relatively large electronic component on a side plate portion of the frame or case. A notch having a width greater than a width of a slit provided in the side plate portion is provided at a position where the slit is provided.

In order to enhance the effect of lowering the temperature according to the present invention, the cutout portion needs to be wider than the conventionally provided slit in order to improve ventilation.

According to a fourth aspect of the present invention, there is provided a switching power supply.
In any one of to 3, the notch is 7 mm,
It has a lateral width of at least 50 mm.

In a conventional switching power supply or the like, generally, a plurality of slits having a width of about 5 mm or less are provided in the side plate portion in order to improve ventilation. The notch provided has a width greater than the width of the slit, so that the temperature of the notch can be reduced. If the width of the notch exceeds 50 mm, the function of dissipating heat of the heat-generating component attached to the L-shaped frame or the case is reduced. Therefore, the width of the notch is preferably 50 mm or less. More preferably, the width is 10 mm or more and 30 mm or less.

[0014]

1 and 2A are exploded perspective views showing an embodiment of a switching power supply according to the present invention. 1 and 2A, reference numeral 1 denotes an L-shaped frame made of metal such as aluminum, and 2 denotes a cover also made of aluminum or the like. These are connected to each other by screws 3 to form a box shape as a whole. Make up the case to play.

Reference numeral 4 denotes a printed circuit board. The printed circuit board 4 is fixed on the bottom plate 1a of the L-shaped frame 1 by screws 6 screwed into a screw cylinder 5 also serving as a spacer.
fixed to a.

On the printed circuit board 4, a line filter 7, a diode 8, capacitors 9A and 9B, a transformer 10, a choke coil 11 constituting a switching power supply are provided.
A, 11B, etc. are mounted. The capacitor 9A is a primary-side capacitor of the transformer 10, and the capacitor 9B is a secondary-side electrolytic capacitor. The choke coils 11A and 11B are arranged on the primary side and the secondary side of the transformer 10, respectively.

Reference numeral 12 denotes transistors mounted on the side plate 1b of the L-shaped frame 1 to dissipate heat using the L-shaped frame 1. These transistors 12 are fixed to the L-shaped frame 1b by screws 14 using an insulating plate 13. And mounted.

As shown in FIGS. 1, 2B and 3, the side plate portion 1c of the L-shaped frame 1 is larger than the ventilation slit 15 at a position close to the capacitor 9A and the choke coil 11A, respectively. Notch 1 of size
6, 17 are provided.

As shown in FIG. 2A, in this embodiment, a portion corresponding to the portion where the notches 16 and 17 are provided in the cover 2 is used to protect the capacitor 9A, the choke coil 11A and the like. A structure is provided in which a perforated plate portion 2a having a structure capable of securing ventilation is provided, and this portion is set inside the side plate portion 1c of the L-shaped frame 1 and fixed with screws 3 (FIG. 4).
(A))). The perforated plate portion 2a does not necessarily need to be provided, and the cover is provided with the cutout portions 16 and 17.
May also cover the outside of the

As described above, the large cutout 16 is formed in the side plate 1c facing the capacitor 9A and the choke coil 11A.
If 17 is provided, the temperature of the cutouts 16 and 17 in the side plate portion 1c of the L-shaped frame 1 becomes low, and radiation and convection of heat from the side plate portion 1c to the capacitor 9A and the choke coil 11A, which are electronic components arranged close to each other. Is reduced and the amount of heat received is reduced, so that the service life can be extended and the reliability can be improved. In addition, the provision of the large cutouts 16 and 17 improves the ventilation of the electronic components 9A and 11A, and the temperature of the electronic components can be reduced from this aspect.

In the present invention, the electronic components arranged in the vicinity of the notches 16 and 17 are preferably winding components such as transformers and choke coils, and relatively long-life components such as capacitors. It may be a semiconductor component such as a transistor.

In the conventional product, the side plate generally has a width of about 5 m to improve ventilation.
Although a plurality of slits 15 of about m or less are provided, the notches 16 and 17 provided by the present invention are formed by making the width W1 (see FIG. 4A) larger than the width of the slits 15. 16 and 17 can be reduced in temperature.

As shown in FIGS. 4A and 4B, the relationship between the width W1 of the notches 16, 17 and the width W2 of the electronic component (capacitor 9A) or the height H1 of the notches 16, 17 is shown.
And the vertical width H2 of the electronic component, or notch 1
The relationship between the area S1 of 6 and 17 and the projected area S2 of the electronic component on the side plate 1c is as follows: 0.5 × W2 ≦ W1 ≦ 3.0 × W2 0.5 × H2 ≦ H1 ≦ 2.0 × H20 0.3 × S2 ≦ S1 ≦ 6.0 × S2.

Regarding the actual dimensions, depending on the size of the switching power supply, the width of the notches 16 and 17 is preferably 7 mm or more in order to obtain the effect of lowering the temperature. The width of the cutouts 16 and 17 is 50 mm.
If the width exceeds the range, the function of dissipating heat of the heat-generating components such as the transistor 12 attached to the L-shaped frame 1 is reduced. Therefore, the width of the cutouts 16 and 17 is preferably 50 mm or less. More preferably, the width is 10
mm or more and 30 mm or less.

It should be noted that the cutouts 16 and 17 may be combined into one to correspond to a plurality of electronic components. Further, the member for attaching the printed circuit board 4 may be configured as a U-shaped frame or case instead of the L-shaped frame. Further, the components corresponding to the notches 16 and 17 may be semiconductor components. In addition, the notches 16 and 17 may have a shape such as a polygon other than a circle and a square. Notch 1
The cutouts 6 and 17 may have a cut structure in which the upper part is open.

[Brief description of the drawings]

FIG. 1 is a partially exploded perspective view showing an embodiment of a switching power supply according to the present invention.

2A is an exploded perspective view of the switching power supply shown in FIG. 1, and FIG. 2B is a perspective view showing the L-shaped frame.

FIG. 3 is a perspective view showing a main part structure of the present embodiment.

FIGS. 4A and 4B are a plan view and a side view, respectively, showing the relationship between the horizontal width and the vertical width of the notch and the electronic component according to the present embodiment.

[Explanation of symbols]

1: L-shaped frame, 1a: bottom plate, 1b, 1c: side plate, 2: cover, 3: screw, 4: printed circuit board, 5: screw cylinder, 6: screw, 9A, 9B: capacitor, 10: transformer, 11A, 11B: choke coil, 12: transistor, 15: slit, 16, 17: notch

Claims (4)

[Claims] 1. A switching power supply using a metal U-shaped or L-shaped frame or case as a heat radiating member, wherein the electronic device is located on a side plate of the frame or case at a position close to a relatively large electronic component. A switching power supply characterized in that a cutout portion having a size close to or larger than a projected area of a component on a side plate is provided. 2. The switching power supply according to claim 1, wherein said electronic component is one of a capacitor, a resistor, a winding component, and a semiconductor component. 3. A switching power supply using a metal U-shaped or L-shaped frame or case as a heat radiating member, wherein a side plate portion is provided on a side plate portion of the frame or case near a relatively large electronic component. A switching power supply characterized in that a notch having a width greater than a width of a slit provided in the slit is provided. 4. The switching power supply according to claim 1, wherein said cutout portion has a width of not less than 7 mm and not more than 50 mm.