JP3596323B2 - Power supply - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power supply device such as a switching power supply, and more particularly, to a structure of a power supply device including a heat sink.
[0002]
[Prior art]
In the above-mentioned switching power supply, a heating element such as a power transistor is mounted on a substrate via a heat radiating plate. Conventionally, a heat radiating plate having a heating element mounted thereon is disposed facing the substrate, and both ends of the heat radiating plate Some of the plurality of connecting legs bent and extended from the portion are locked and connected to the board, and the other connecting legs are inserted and connected to the connecting holes of the board.
[0003]
[Problems to be solved by the invention]
In order to improve the heat dissipation characteristics of the heat sink, it is desirable to increase the heat dissipation area as much as possible. However, the size of the substrate placed facing the substrate should be at most as large as the substrate. I could not do it.
[0004]
Also, in the above-described mounting structure of the heat sink, the heat sink is inclined with respect to the board, and some connecting legs are locked to the end of the board, and then the heat sink is attached to the board centering on the locking portion. Therefore, it is necessary to insert another connecting leg into the connecting hole of the substrate and connect the connecting legs by swinging them in parallel to each other, and it takes time and effort to mount the heat sink. In particular, in the case of automating this assembling, the process of swinging the member around one point requires considerably difficult control.
[0005]
The present invention has been made in view of such a point, and it is an object of the present invention to provide a power supply device capable of improving workability of assembling a heat sink to a board while improving heat dissipation characteristics of the heat sink. The main purpose is.
[0006]
[Means for Solving the Problems]
The present invention is configured as follows to achieve the above object.
[0007]
That is, in the power supply device according to the first aspect of the present invention, two first and second substrates that face each other at a predetermined interval are arranged in a case, and the first and second substrates are bent in an L shape to form the first and second substrates. The first heat radiating surface faces the heat radiating plate on which the heat radiating surface is formed on the inner corner side of the both heat radiating surfaces, and the second heat radiating surface is between the two substrates. The heat radiation plate has a first connecting portion extending toward the first substrate from a tip of the first heat radiation surface on which a heating element is mounted, A second connecting portion is provided at a bent portion connecting the heat dissipation surfaces, and the first substrate has an engaging hole corresponding to the first connecting portion, and has an edge corresponding to the second connecting portion at an edge thereof. Having an engaging portion, inserting the first connecting portion of the heat sink into the engaging hole of the first substrate. And, from the state of the temporary engagement in which the second connecting portion is opposed to the engaging portion, the entire heat radiating plate is relatively slid along the first heat radiating surface with respect to the first substrate. Thus, the first connecting portion is engaged with the engaging hole, and the second connecting portion is engaged with the engaging portion so as to be immovable in the substrate surface direction.
[0008]
According to a second aspect of the present invention, in the power supply device according to the first aspect, the heat dissipation plate includes one first connection portion and a pair of the second connection portions. An opening formed between the two connecting portions faces a soldering portion between the lead terminal of the heating element mounted on the first heat radiation surface and the first substrate.
[0009]
According to a third aspect of the present invention, in the power supply device according to the first or second aspect, the second heat radiating surface of the heat radiating plate is positioned and fitted to an engaging portion formed on a back wall surface of the case. .
[0010]
According to a fourth aspect of the present invention, in the power supply device according to any one of the first to third aspects, the heating element is screw-connected to an element mounting portion of the heat sink where the heating element is mounted with a screw. An abutment means for preventing rotation about the site is provided.
[0013]
[Action]
According to the configuration of the invention according to claim 1, since by bending a heat sink L-shaped to form a two heat radiating surfaces, while it is possible to enhance the heat radiation performance, a set of radiating plate to the first substrate at the time of attaching, engages a coupling portion and the engaging portion at the connecting portion from the state in which the engaged tentatively retaining the engagement portion of the first substrate, thereby relatively sliding the heat radiating plate to the first substrate Combine. As a result, the radiator plate is engaged and connected to the first substrate so as not to move in the direction of the substrate surface. Moreover, when assembling the heat sink to the first substrate, first, the first connecting portion is inserted into the engaging hole of the first substrate, and the second connecting portion is connected to the engaging portion of the first substrate. By sliding the entire heat radiating plate along the first heat radiating surface from the state in which the first heat radiating plate faces the first heat radiating surface, the first connecting portion is engaged with the engaging hole, and the second connecting portion is engaged with the engaging portion. As a result, the radiator plate is engaged and connected to the first substrate so as not to move in the direction of the substrate surface. Further, heat is radiated from the second heat radiating surface to a large space between the two first and second substrates facing each other in the case.
[0014]
According to the configuration of the second aspect of the invention, the radiator plate engaged and supported by the first substrate via the first and second connecting portions is held in a three-point support state. In addition, through the opening formed between the pair of second connecting portions, a soldering process is performed between the lead terminal of the heating element mounted on the first heat dissipation surface of the heat dissipation plate and the substrate.
[0015]
According to the configuration of the third aspect of the present invention , the entire heat radiating plate is engaged and supported by the substrate near both ends of the first heat radiating surface, while the second heat radiating plate is connected to the second heat radiating surface. The heat radiation surface is cantilevered, but its position is stabilized by being positioned and engaged with the inner wall of the case.
[0016]
According to the configuration of the invention according to claim 4, when the heating element is attached to the heat radiating plate with the screw, the screw operation can be performed without rotating together by positioning and engaging the heating element with the mounting position of the heat radiating plate.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
1 is an external perspective view of a power supply device according to the present invention, FIG. 2 is a cross-sectional plan view thereof, FIG. 3 is a longitudinal side view thereof, and FIG. 4 is a longitudinal front view thereof.
[0021]
The case 1 of the power supply device includes a resin case main body 1A and a resin front case 1B fitted and connected to a front end thereof, and through flange portions 1a formed on the upper, lower, left, and right sides of the case main body 1A. It is configured such that it can be screw-connected to a wall surface of a switchboard or the like, or can be fitted and connected to an arbitrary position of the support rail 2 attached to the wall surface from the front.
[0022]
The case body 1A is formed in a box shape having an open front end, and a heat radiation slit 3 is formed on the peripheral wall surface thereof. A locking hole 5 for engaging and connecting the locking claws 4 extended one by one is formed.
[0023]
At the top and bottom of the front end of the front case 1B, a large number of wiring connection portions 6 are formed in parallel and defined, and each wiring connection portion 6 is provided with a connection terminal 8 having a terminal screw 7, A wiring cover 9 that covers the front surface of the wiring connection portion 6 is provided so as to be swingably opened and closed. Further, on the front surface of the front case 1B, a display hole 11 facing the built-in monitor lamp 10 and an operation hole 13 facing the mode switch 12 are formed.
[0024]
The power supply circuit incorporated in the case 1 having the above configuration includes a first substrate 21 incorporated on the right side of the case body 1A, a second substrate 22 incorporated on the left side, and a third substrate assembled on the front case 1B. 23, various electronic components and elements are mounted on each of the boards 21, 22, and 23, and the boards 21, 22, and 23 are connected to each other by wiring.
[0025]
Here, as shown in FIG. 4, the first and second substrates 21 and 22 are vertically extended from the front opening of the case along the front and rear long guide grooves 24 formed on the upper and lower inner wall surfaces of the case main body 1A. The two substrates 21 and 22 are arranged so as to face each other in parallel at predetermined intervals. Further, the third substrate 23 is inserted and mounted in the connection terminals 8 arranged in parallel on the upper and lower sides of the front case 1B and connected by soldering. In a state where the front case 1B is assembled to the case main body 1A, As shown in FIGS. 2 and 3, a board portion 22a extending from the front end of the second board 22 is inserted into the front case 1B beyond the third board 23, and The monitor lamp 10 and the mode changeover switch 12 are mounted on the display hole 11 and the operation hole 13 so as to be attached to the display hole 22a.
[0026]
A heat sink 25 is mounted on the outer surface of the first substrate 21, and the detailed structure thereof is shown in FIGS. That is, the heat radiating plate 25 is formed by punching and pressing an aluminum plate to be bent into an L shape, and has a first heat radiating surface 25a facing the outer surface of the substrate 21 and a second substrate A heat radiating element 26 such as a power transistor is connected and fixed to a predetermined position on the inner surface of the first heat radiating surface 25 a by a single screw 27. ing. The first and second heat radiating surfaces 25a and 25b include front and rear surfaces and side surfaces, respectively.
[0027]
A first connecting portion 31 is provided at a front end portion of the first heat radiating surface 25a of the heat radiating plate 25, and a pair of upper and lower bent portions connecting the first heat radiating surface 25a and the second heat radiating surface 25b are provided. A second connecting portion 32 is provided, and the radiator plate 25 is supported by the substrate 21 by the three connecting portions 31, 32, and 32.
[0028]
The first connecting portion 31 is formed by bending a leg-like portion extending from the front end of the first heat radiation surface 25a toward the substrate, and the front end portion of the first connecting portion 31 is connected to the substrate 21. An engagement hole 33 is formed for joint support. Here, a cutout portion 34 having a width corresponding to the thickness of the substrate 21 is formed at the upper edge of the distal end portion of the first connection portion 31, and the engagement hole 33 is formed in the entire first connection portion 31. Are formed in such a manner that an insertion hole 33a having an upper and lower width through which is inserted and an engagement hole 33b having a smaller upper and lower width are connected in a hook shape. Therefore, the notch 34 is engaged with the upper edge of the engaging hole 33b by sliding the radiator plate 25 forward after the distal end portion of the first connecting portion 31 is inserted into the insertion hole 33a and temporarily engaged. Accordingly, the first connecting portion 31 is engaged so as not to be drawn out from the engaging hole 33 in the direction of the substrate surface. In the illustrated embodiment, the engaging hole 33 is a cutout hole opened at the front edge of the substrate 21, but may be an independent hook-shaped through hole.
[0029]
The second connecting portion 32 is formed as a pair of upper and lower leg-shaped portions which are cut and left above and below a substantially rectangular opening 35 formed at a bent portion of the heat radiating plate. A pair of upper and lower engaging portions 36 for engaging and supporting the second connecting portion 32 are formed in a recess. Here, cutout portions 37 each having a width corresponding to the thickness of the substrate 21 are formed at the upper end edge of the upper second connection portion 32 and the lower end edge of the lower second connection portion 32, respectively. The upper and lower second connecting portions 32 are respectively engaged with the upper and lower engaging portions 36 from the rear, and the notches 37 are engaged with the upper and lower edges of the upper and lower engaging portions 36, respectively. The connecting portion 32 is engaged so that it cannot be pulled out from the engaging hole 33 toward the substrate surface.
[0030]
That is, when connecting the heat radiating plate 25 to the substrate 21, first, as shown in FIG. 7, the distal end of the first connecting portion 31 is inserted into the insertion hole 33 a of the engagement hole 33, and The two connecting portions 32 are positioned and opposed to the upper and lower engaging portions 36, and then the entire heat radiating plate 25 is slightly slid forward, so that the first connecting portion 31 is inserted into the engaging holes 33 as described above. The upper and lower second connecting portions 32 are respectively engaged with the upper and lower engaging portions 36 so as not to be able to be pulled out in the direction of the substrate surface. As shown in FIG. 8, the radiator plate 25 is stably engaged with and supported by the substrate in the three-point engaged state.
[0031]
As described above, a lead terminal 26a bent toward the substrate 21 extends from the rear end of the heating element 26 which is screw-connected to the inner surface of the first heat radiation surface 25a of the heat radiation plate 25 connected to the substrate 21. In addition, a connection hole 38 is formed in the substrate 21 so as to insert the tip of the lead terminal 26a. Here, the connecting hole 38 is formed as a long hole extending forward and backward. In the positioning state before the heat sink 25 is slidably engaged with the substrate 21 as described above, the lead terminal 26a is connected to the connecting hole 38. When the heat sink 25 is slid forward and engaged and connected, the lead terminal 26a moves to the front of the connection hole 38. In this state, the opening 35 of the radiator plate 25 faces the connection hole 38, and the insertion end of the lead terminal 26 a is soldered to the circuit pattern formed on the outer surface of the substrate 21 through the opening 35. It is.
[0032]
Further, the heat radiating plate 25 is electrically connected to the ground line of the substrate 21 in order to enhance noise characteristics. That is, a conductive metal member 39 bent toward the substrate 21 is riveted to the inner surface of the first heat radiation surface 25a, and a front end of the conductive metal member 39 is inserted into the connection hole 40 of the substrate 21 to form a ground circuit. Soldered to the pattern. Also in this case, the connection hole 40 through which the conduction metal fitting 39 is inserted is long in the front and rear direction so as to correspond to the forward slide when the heat radiation plate 25 is connected to the substrate 21.
[0033]
In a state where the substrates 21 and 22 are inserted and mounted in the case body 1A, the second heat radiation surface 25b facing the space between the two substrates 21 and 22 comes into full contact with the inner wall of the case and the second heat radiation. The fitting hole 41 formed in the surface 25b is fitted to a projection 42 as an engaging portion projecting from the inner wall of the case, and the cantilevered second heat radiation surface 25b is formed inside the case body 1A. It is designed to be positioned and supported by the back wall. Here, the protrusion 42 is formed corresponding to a resin injection gate when the case main body 1A is injection-molded.
[0034]
Further, an insulating sheet 43 is interposed between the substrate 21 and the heating element 26 attached to the first heat radiating surface 25a. As shown in FIG. In addition, the positioning member is positioned by being inserted into and supported by the conduction metal fitting 39 and the projection portion 43a provided at the rear end portion is engaged and supported by the opening 35.
[0035]
As shown in FIG. 11, a second heat radiating plate 45 made of an aluminum plate and mounted with a small heat generating element 44 that generates a small amount of heat is also connected to the outer surface of the second substrate 22 as shown in FIG. The heat radiating plate 45 is provided with three connecting legs 46 and 47 at the front and rear ends thereof, and a pair of upper and lower connecting legs 46 at the front is engaged and supported by the substrate 22 so as not to come out in the substrate surface direction. At the same time, the rear connecting leg 47 is simply inserted into and supported by the substrate 22. Further, a conduction metal fitting 48 rivet-connected to the inner surface of the heat sink is soldered to the substrate 22 and connected to an earth line.
[0036]
The present invention can be implemented in the following forms.
[0037]
(1) When the heat generating element 26 is connected to the heat radiating plate 25 with one screw 27, the screw operation may cause the heat generating element 26 to rotate around the screw connection portion as shown in FIG. A plurality of detent projections 51 abutting on the outer periphery of the heat generating element 26 are formed at the element mounting portion of the heat radiating plate 25 by pressing, or, as shown in FIG. The stop protruding piece 52 is cut out from the heat radiating plate 25 or, as shown in FIG. 14, a shallow concave groove 53 for positioning and engaging the entire heat generating element 26 is formed by cutting or press forming. It is convenient to provide a means for preventing the axles from rotating together. Further, as shown in FIG. 15, it is also possible to prevent the heat generating element 26 from rotating together by using a pair of conductive fittings 39 for connecting the heat radiating plate 25 to the ground line.
[0038]
(2) The structure for engaging and connecting the heat radiating plate 25 to the substrate 21 in a retaining state is not limited to the above structure. For example, as shown in FIG. 16, the structure is formed at the distal end of the first connecting portion 31. The engagement protrusion 54 formed in the engagement hole 33 of the board 21 is engaged with the engagement hole 54, and the engagement hole 56 formed in the second connection portion 32 is engaged with the rear end edge of the board 21. It is also possible to engage the engagement protrusion 57 formed in the engagement portion 36 and to stably engage and support the substrate 21 by sliding the entire radiator plate 25 forward.
[0039]
(3) The mounting location of the heating element 26 is not necessarily limited to the first heat radiating surface 25a, but may be mounted on the second heat radiating surface 25b.
[0040]
【The invention's effect】
As is clear from the above description, the following effects can be expected according to the present invention.
[0041]
According to the invention of claim 1, the heat dissipation plate is bent in an L-shaped can be efficiently radiated from the heat radiating surface of the large heard two surfaces, it is possible to improve the heat radiation performance greatly. In addition, when the heat sink is mounted on the first substrate, the heat sink may be relatively slid and moved in the temporarily engaged state, and compared with a conventional mounting structure involving swinging. The operation becomes simple, and the assembling workability can be improved. Moreover, when the heat sink is mounted on the first substrate, a positioning step of bringing the heat sink closer to the first substrate from the surface direction and an engaging step of slightly sliding the positioned heat sink may be performed. As compared with the conventional mounting structure involving swinging, the operation is simpler, and the workability in assembling can be improved. In particular, according to the present invention, a simple operation of simply moving the radiator plate linearly in two orthogonal directions is sufficient, so that the assembling can be easily automated. Further, since the second heat radiating surface faces the space formed between the first and second substrates on the two sheets disposed opposite to each other, a special space for arranging the second heat radiating surface is provided in the case. A large heat radiation surface can be secured without providing the power supply device, and a power supply device with high heat radiation performance can be configured without increasing the size of the case.
[0042]
According to the second aspect of the present invention, since the heat sink is engaged and supported by the substrate by the three-point engagement support, the heat sink can be stably engaged and supported by the substrate with minimum engagement. The opening formed between the second connecting portions can be used also as a space for soldering processing, and the assembling workability is further improved.
[0043]
According to the third aspect of the present invention, since the second heat radiating surface is positioned and engaged with the inner wall of the case , the second heat radiating surface bent and extended in a cantilever manner can be stably accommodated and supported in the case. It also has excellent mechanical durability.
[0044]
According to the invention according to claim 4, since the heating element is attached to the heat sink with one screw, the heating element can be screwed in a detent and abutting state without using a special jig. Setting and screw tightening are quick and easy, which is effective in improving the assembling workability.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the overall appearance of a power supply device.
FIG. 2 is a cross-sectional plan view of the power supply device.
FIG. 3 is a vertical sectional side view of the power supply device.
FIG. 4 is a vertical sectional front view of the power supply device.
FIG. 5 is a perspective view of a first substrate on which a heat sink is mounted, as viewed from the front.
FIG. 6 is an exploded perspective view of a first substrate and a heat sink mounted on the first substrate as viewed from the front.
FIG. 7 is a partially cutaway perspective view showing a process of assembling a heat sink to a first substrate.
FIG. 8 is a partially cutaway perspective view of the first substrate on which the heat sink is mounted, as viewed from the rear.
FIG. 9 is an exploded perspective view of the first substrate and a heat sink attached to the first substrate as viewed from the rear.
FIG. 10 is a perspective view of the heat sink seen from the inner surface side.
FIG. 11 is a perspective view of the first and second substrates arranged opposite to each other as viewed from the rear.
FIG. 12 is an exploded perspective view showing an example of a heating element rotation stopping means.
FIG. 13 is an exploded perspective view showing another example of the rotation stopping means of the heating element.
FIG. 14 is an exploded perspective view showing another example of the means for preventing rotation of the heating element.
FIG. 15 is an exploded perspective view showing another example of the means for preventing rotation of the heating element.
FIG. 16 is an exploded perspective view showing another embodiment of the engagement structure for connecting the heat sink to the board.
[Explanation of symbols]
1 case 21 substrate 22 substrate 25 radiating plate 25a first radiating surface 25b second radiating surface 26 heat generating element 26a lead terminal 31 first connecting portion 32 second connecting portion 33 engaging hole 35 opening 36 engaging portion

Claims (4)

In a case, two first and second substrates that face each other at a predetermined interval are arranged, and a heat radiating plate that is bent into an L shape to form first and second heat radiating surfaces is attached to the two heat radiating surfaces. The first heat radiation surface is opposed to the first substrate located on the inner corner side of the second heat radiation surface, and the second heat radiation surface is disposed so as to face a space between the two substrates,
The heat radiating plate has a first connecting portion extending toward the first substrate from a tip of the first heat radiating surface on which a heat generating element is mounted, and has a bent portion connecting the both heat radiating surfaces. A second connecting portion, wherein the first substrate has an engaging hole corresponding to the first connecting portion, and has an engaging portion for the second connecting portion on an edge thereof;
From the state of temporary engagement in which the first connecting portion of the heat sink is inserted into the engaging hole of the first substrate and the second connecting portion faces the engaging portion, the entire heat sink is changed. Relative to the first substrate along the first heat radiating surface, so that the first connection portion is in the engagement hole and the second connection portion is in the engagement portion. A power supply device, wherein the power supply device is immovably engaged in a plane direction . The heat dissipation plate is formed with one first connection portion, and the second connection portion is formed as a pair. An opening formed between the pair of second connection portions is formed on the first heat dissipation surface. 2. The power supply device according to claim 1, wherein the power supply device faces a soldering portion between the mounted lead terminal of the heating element and the first substrate . The power supply device according to claim 1, wherein the second heat radiating surface of the heat radiating plate is positioned and fitted to an engaging portion formed on a rear wall surface of the case . 4. The device according to claim 1, further comprising a contact means for preventing the heat generating element from rotating around a screw connection portion, at a position where the heat generating element is mounted with a screw. power supply of crab described.

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