JPH0632787Y2 - Switching power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field) The present invention relates to a mounting structure of a switching heating element in a switching power supply device.

(Prior Art) As a switching power supply device of this type, for example,
Some have an internal configuration as shown in the figure.

In the figure, reference numeral 101 is a rectangular printed circuit board, and on the printed circuit board 101, a noise filter circuit 104 including a capacitor 102 and a choke coil 103, and an input side rectifying / smoothing circuit 107 including a diode 105 and a capacitor 106. , Transformer 108, diode 109 and capacitor 1
An output side rectifying / smoothing circuit 111 composed of 10 and a switch circuit 11 composed of a power transistor 112 and a driving circuit 113 thereof.
4, a detection circuit 117 including a photocoupler 115, a resistance element 116, and the like are provided, and an input / output terminal portion 120 is provided on a side portion.

FIG. 8 shows the circuit configuration of the input / output terminal unit 120.
The AC voltage input from the input side of the is passed through the noise filter circuit 104, converted into a DC voltage by the input side rectifying and smoothing circuit 107, and given to the primary side of the transformer 108, and the transformer 108 is turned on by the signal from the switch circuit 114. When turned off, the AC voltage is sent to the secondary side, and this AC voltage is converted to a DC voltage again by the output side rectifying and smoothing circuit 111, and the input / output terminal unit 120
It is designed to be given to the output side of. Further, the detection circuit 117 detects the output voltage on the secondary side of the transformer 108 and outputs the detection output corresponding to the fluctuation of the output voltage to the switch circuit 11.
4 is provided so as to output to the drive circuit 113, and the drive circuit 113 is configured to control ON / OFF of the power transistor 112 in response to the input of the detection output.

(Problems to be solved by the invention) However, in such a switching power supply device, the amount of heat generated by the diode 109 and the power transistor 112 in the output-side smoothing circuit 111 is large, and therefore, heat is radiated from the diode 109 and the power transistor 112. Although the fins for use 121 are integrally provided, in such a configuration in which the heat dissipation fins 121 are provided, heat dissipation from the heat dissipation fins 121 adversely affects elements such as the capacitors 106 and 110, causing performance deterioration of those elements. Therefore, there is a problem that the life of the device is shortened.

In order to avoid this problem, it is conceivable to increase the arrangement interval between the radiation fin 121 and the capacitors 106, 110, etc., but the arrangement configuration of each element on the substrate 101 becomes complicated, and There is a problem that the device becomes large when a large size one is used.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a switching power supply device in which heat from a heating element does not reach a device such as a capacitor and is efficiently radiated to the outside.

(Means for Solving the Problems) In order to achieve such an object, the present invention provides a substrate in a casing, and the substrate is provided with a noise filter circuit and an AC voltage from the noise filter circuit is converted into a DC voltage. An input side rectifying / smoothing circuit, a transformer to which a DC voltage from the input side rectifying / smoothing circuit is given to the primary side, a switch circuit for giving a switch signal to the transformer, and 2 of the transformers based on the signal from the switch circuit. In a switching power supply device in which an output side rectifying / smoothing circuit that outputs an AC voltage applied from the next side as a DC voltage is arranged, a plurality of heat radiators are separately arranged between the back surface of the substrate and the inner surface of the casing. In addition, the switching heating element used in each circuit is individually attached to each radiator. It became the composition.

(Operation) According to this configuration, the heat radiator integrally including the switching heat generating element is provided between the back surface of the substrate and the inner surface of the casing, so that the heat dissipating element is separated from the other circuit component elements disposed on the front surface side of the substrate. The heat from the heating element does not reach the condenser or the like, and is radiated to the outside from the casing side.

Further, since the switching heating elements are individually attached to each heat radiator, it is possible to avoid the interference of noises of the switching heating elements.

Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an external perspective view of a switching power supply device according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the same, FIG. 3 is a cross sectional view showing the same internal structure, and FIG. 4 shows the same internal structure. FIG. Since the circuit configuration of the switching power supply device of the present invention is similar to that shown in the conventional example shown in FIG. 8, its explanation is omitted.

In the figure, reference numeral 1 is a resin casing that constitutes the outer shape, and is composed of a casing body 2 whose one side surface is open, and a lid body 3 which is provided so as to cover the opening.

The casing main body 2 is configured by integrally erected a peripheral wall portion 5 from a base portion 4, and the peripheral wall portion 5 has a rectangular shape in which its four corners are stepwise recessed portions 6 in its front shape. ing. Each of the pair of side portions 5a located in the longitudinal direction of the peripheral wall portion 5 is provided with a slit hole 7 for heat radiation in a grid pattern, and the pair of side portions 5a located in a direction orthogonal to the surface of the side portion 5a. A locking hole 8 is provided at a position near the opening of the side portion 5b. Each of the above-mentioned concave portions 6 of the base portion 4
Each of the mounting holes 10 is provided at a position corresponding to.

As shown in FIG. 5, a mounting groove 12 is provided in the longitudinal direction on the back surface of the base portion 4, and the lower part of the mounting groove 12 is made of a resin that elastically projects toward the mounting groove 12 side. Locking member 13 is provided.

The front shape of the lid 3 is similar to the front shape of the peripheral wall portion 5 of the casing body 2, and a pair of input terminal portions 14 is provided at the lower edge thereof.
And one ground terminal portion 15 are provided, and two pairs of output terminal portions 16 are provided at the upper edge. Each of the above terminals
14, 15 and 16 are configured by attaching terminal screws to terminal fittings. At the inner side of the side edge orthogonal to the upper and lower edges, a locking piece 18 that locks from the inside to the locking hole 8 provided in the peripheral wall portion 5 when the casing body 2 is mounted is provided. Further, an adjustment hole 19 and an operation display hole 20 are provided on the upper surface of the lid 3.

The lid 3 is attached to the casing body 2 by the above-mentioned locking piece 18
Is integrally fixed in a state in which is locked in the locking hole 8.

Next, the internal configuration of the device will be described.

In the casing 1, a first substrate 20 provided so as to face the inner surface of the lid body 3, and second and third substrates 21, 22 that face the inner surface of the side portion 5b of the peripheral wall portion 5 of the casing body 2. And a fourth substrate 23 provided so as to face the inner surface of the base portion 4 of the casing body 2 contact their edges to form a frame-shaped body in a planar configuration by the respective substrates 20, 21, 22, 23. It is provided to configure. The first substrate 20 is the lid 3
The lower ends of the terminal fittings of the respective terminal parts 14, 15, 16 are integrally fixed to the lid body 3 by being connected and fixed by soldering,
A coil 25a and a capacitor 25b that form a noise filter circuit, a diode 25c that forms an input side rectifying and smoothing circuit, and a fuse 25d are mounted on the surface side of the lid 3 that faces the inner surface.

One end of the second substrate 21 and the third substrate 22 is connected to both ends of the fourth substrate 24 by a connector 28 that can also be electrically connected, and is integrally fixed to the fourth substrate 23. The second, third, and fourth boards 21, 22, 23 that are integrated are fixed to the fixing screw 29 on the base portion 4 of the casing body 2 at the mounting hole 30 portion where the fourth board 23 is provided at the central position thereof. As a result, the casing 1 is fixedly provided. First substrate
Each lead wire 32 electrically connects 20 to the second and third substrates 21 and 22.

The surface of the second substrate 21 facing the third substrate 22 is provided with the capacitors 33a and the like forming the input side rectifying / smoothing circuit, and the surface of the third substrate 22 facing the second substrate 21 is an output side rectifying / smoothing circuit. The condenser 34a, the photocoupler 34b, the adjusting screw 34c, the operation indicator lamp 34d, etc.
A transformer 38a, a power transistor 38b forming a switch circuit, a diode 38c forming an output side rectifying / smoothing circuit, and the like are mounted on the surface of the substrate 23 opposite to the surface of the casing body 2 facing the base portion 4.

As shown in FIG. 6, the fourth substrate 23 is provided with a pair of protrusions 42 in the central portion on the side where it is connected to the second and third substrates 21 and 22, while the second and second 4th board 2 of 3 boards 21 and 22
A pair of notches 44 is provided in the center on the side connected to 3. Then, the second and third substrates 21 and 22 and the fourth substrate 23
When they are connected to each other, the protruding portion 42 protrudes to the back surface side of the second and third substrates 21 and 22 through the cutout portion 44, and the protruding portion 4
The power transistor 38b and the diode 38c described above are respectively mounted on the device 2.

Each of 46 is a heat sink as a radiator of the power transistor 38b and the diode 38c, and the power transistor 38b and the diode 38c, on the other hand, face the back surfaces of the second and third substrates 21 and 22 of the heat sink 46. Is integrally fixed to the inner surface side of the bending piece 47 positioned as described above. The heat sink 46 is formed by punching and bending a metal plate, and the bent portion 48 is formed.
An opening 50 provided with a locking portion 49 is provided in the. The heat sink 46 has the locking portion 49 on which the second and third substrates are attached.
The ends of the protruding portions 42 of 21, 22 are fixed by being locked.

When the power transistor 38b and the diode 38c are fixed to the second and third substrates 21 and 22 on the one hand, and the heat sink 46 on the other hand, the first and second substrates 21 and 22 and the heat sink 46 are relatively fixed. When displacement occurs, the fixed lead portions 38b ₁ and 38c _{1 of} the power transistor 38b and the diode 38c to the first and second substrates 21 and 22 may be cut off.
Since the second and third substrates 21 and 22 and the heat sink 46 are fixed as described above, the above relative displacement does not occur, so that there is no fear of cutting the fixed lead portions 38b ₁ and 38c ₁ .

Then, as described above, the second, third, and fourth substrates 21, 22, and 23 are connected, and the internal structural body 51 to which the heat sinks 46 are integrally attached is arranged in the casing body 2 in a predetermined direction. Installed in the heat sink 46
Each of the bent pieces 47 is just fitted into the storage space 52 formed on the inner surface of the side portion 5b of the peripheral wall portion 5 by providing the concave portion 6 of the casing body 2.
The above-mentioned internal structure 51 is incorporated into the casing body 2 by connecting the lead wire 32 to the first substrate 20 integrally fixed to the lid body 3.
The second substrate, the third substrate, and the fourth substrates 21, 22, 23 are connected to each other via the, and the lid body 3 is mounted on the casing body 2 together with the assembling.

In the above, the feature of the present invention is that the respective heat sinks are located between the back surfaces of the second, third and fourth boards 21, 22, 23 and the inner surface of the casing 1, and the second and third boards 2 thereof are provided.
A power transistor as a switching heating element is provided on each of the bending pieces 47 located in the storage space 52 formed between the back surfaces of the reference numerals 1, 22 and one side portion b of the peripheral wall portion 5.
The point is that the 38b and the diode 38c are individually attached.

By disposing the power transistor 38b, the diode 38c, and the bent piece 47 of the heat sink 46 to which they are attached separately in the storage space 52 in this way, heat radiation from them is blocked by the second and third substrates 21 and 22. Being
It does not reach the inner side of the casing 1 where other elements are arranged, but is smoothly discharged to the outside from the slit holes 7 of the peripheral wall portions 5 located at both ends of the storage space 52.

Furthermore, by separately mounting the power transistor 38b and the diode 38c on the heat sink 46, it is possible to prevent the switching noises of the power transistor 38b and the diode 38c from interfering with each other and causing a huge noise level.

Therefore, according to the present invention, a heat radiator that integrates the switching heating element is provided between the back surface of the substrate and the inner surface of the casing and is separated from the other circuit components, so that the heat generated from the switching heating element can be reduced. Is released to the outside without reaching the capacitor or the like, whereby performance deterioration due to heat of the capacitor or the like can be avoided, and the life of the power supply device can be extended.

In addition, since each of the switching heating elements is individually attached to each radiator, it is possible to prevent the switching noises from interfering with each other and generate a huge noise level, which may cause malfunction or damage to other connected devices. Is prevented.

[Brief description of drawings]

1 to 6 relate to an embodiment of the present invention. FIG. 1 is an external perspective view of a switching power supply device according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the same, and FIG. FIG. 4 is a longitudinal sectional view showing the internal structure, FIG. 5 is a rear view of the same, and FIG. 6 is a bottom view of the internal structure. 7 and 8 relate to a conventional example, FIG. 7 is an internal configuration diagram of a switching power supply device, and FIG. 8 is a block circuit diagram showing a circuit configuration. 1 ... Casing, 21 ... 2nd board (board), 22 ... 3rd board (board), 38b ... Power transistor (switching heating element), 38c ... Diode (switching heating element), 46 ... Heat sink (Heat radiator).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideo Nagaizumi 2075 Kaiyoshi, Okayama City, Okayama Prefecture Okayama Tateishi Electric Co., Ltd. (56) References: 58-145088 (JP, U) (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A substrate is provided in a casing, and a noise filter circuit, an input side rectifying / smoothing circuit for converting an AC voltage from the noise filter circuit into a DC voltage,
A transformer in which the DC voltage from the input side rectifying / smoothing circuit is applied to the primary side, a switch circuit for applying a switch signal to the transformer, and an AC voltage applied from the secondary side of the transformer based on the signal from the switch circuit. In a switching power supply device in which an output side rectifying / smoothing circuit for outputting as a DC voltage is arranged, a plurality of radiators are separately arranged between the back surface of the substrate and the inner surface of the casing, and used in each of the circuits. The switching power supply device is characterized in that the switching heat generating element is individually attached to each of the radiators.