JP3498024B2 - Transformer heat dissipation structure - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a heat dissipation structure of a transformer, and more particularly, to fixing a transformer core at a constant pressure and not only heat dissipation of the transformer core but also a winding portion. In which heat dissipation is considered to be good. 2. Description of the Related Art As shown in FIG. 5, a transformer used in a conventional high-power type power supply has a winding part 3 in which a primary winding and a secondary winding are resin-molded, and a winding part 3 having the same. 3 are constituted by transformer cores 4a and 4b constituting a magnetic circuit, and a leaf spring 10 which is screwed to a radiation base plate (not shown) by screws 6a and 6b. By fixing the leaf spring 10 with screws 6a and 6b, the transformer core 4 is pressed by the spring pressure of the leaf spring 10.
a, 4b and the winding part 3 are fixed to form a transformer. As described above, the transformer used in the conventional high-power type power supply is screwed to the heat-radiating base plate (not shown), and the fastening force of the screws 6a and 6b and the leaf spring 10
The transformer cores 4a and 4b and the winding part 3 are fixed by the spring pressure. For this reason, the contact pressure varies depending on how the screws 6a, 6b are tightened, and the magnetic resistance of the transformer cores 4a, 4b, particularly the magnetic path formed by the outer legs 5a, 5b of the transformer core changes, and the characteristics vary. Further, loosening of the screws 6a and 6b causes a decrease in the contact pressure, an increase in the magnetic resistance and a deterioration in the characteristics. Further, since a high voltage is applied to the primary winding of the winding portion 3, the primary winding of the winding portion 3 is molded with a resin such as an epoxy resin to secure a withstand voltage. Heat dissipation was required. According to the present invention, for example, a large transformer used for a high-power type power supply has a structure capable of being screwed to a heat-radiating base plate or the like. Another object of the present invention is to provide a heat dissipation structure of a transformer that does not deteriorate the characteristics of the transformer and that can satisfactorily dissipate heat from the surface of a resin-molded winding portion. FIG. 1 is a block diagram showing the principle configuration of the present invention.
This will be described below. In FIG. 1, 1 is a metal plate, 2
Is a leaf spring, 3 is a winding part, 4a and 4b are transformer cores, 5
a and 5b are outer legs of the transformer core, 6a and 6b are screws, 1
1 is a notch, 12 is a protrusion, 13 is a screw hole, 21 is both arms, and 22 is a bent ceiling. The above object of the present invention is achieved by the following constitution . A ceiling part 22 is bent inward so as to pressurize the outer legs 5a and 5b of the transformer core, and extends in an L-shape from both ends of the ceiling part 22 so as to hold the transformer cores 4a and 4b. A leaf spring 2 made of an elastic material having both arm portions 21 formed thereon and a notch portion 11 in which both arm portions 21 of the leaf spring 2 can be locked are arranged to face the edge, and a molding surface 3a of the winding portion 3 is formed. , Protruding part 12 that contacts 3b is opposed
The notch 11 and the protrusion 1
2 comprises a metal plate 1 arranged on separate sides, and when the two arms 21 of the leaf spring 2 are locked to the metal plate 1, the two inwardly-transformed outer cores 5a are formed by the inwardly bent ceiling. , 5b are in pressure contact with each other, the transformer cores 4a, 4b are held by the arms 21 and the projections 12 of the metal plate 1 are in contact with the molding surface of the winding portion 3 to improve heat dissipation. Good, and furthermore of the metal plate adjacent to the projection on the diagonal of the metal plate.
The holes 13 in at least two locations provided in the corner, radiating Base plate
It is characterized in that the mounting density is improved by being able to be screwed at a rate or the like. As a result, the following functions and effects can be obtained. (1) When the leaf spring is locked to the metal plate, the outer legs of the transformer core come into contact with each other, and the projection of the metal plate comes into contact with the molding surface of the winding portion. In addition to effectively preventing the characteristic from changing due to the change, the heat generated by the winding portion can be effectively radiated through the protrusion of the metal plate. In addition, since the leaf spring is locked to the metal plate, a fixing screw fixing portion is not required, dead space is eliminated, and when this is incorporated into a product, the mounting density can be increased and the product can be downsized. (2) Since the metal plate can be screwed to the heat dissipation base plate or the like, heat dissipation characteristics can be improved. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an exploded perspective view of a heat dissipation structure of a transformer according to the present invention, FIG. 2 is an assembled perspective view of a heat dissipation structure of a transformer according to the present invention, and FIG. It is a comparative figure. In the drawing, 1 is a metal plate, 2 is a leaf spring, 3
Is a winding surface, 3a and 3b are molding surfaces of the winding portion, 4a and 4b are transformer cores, 5a and 5b are transformer core outer legs, 6
a and 6b are screws, 11 is a notch, 12 is a protrusion, 1
3 is a hole for screwing, 21 is both arms, 22 is a bent ceiling, 23 is a locking part, 24 is a holding part, 31 is a primary winding terminal, and 32 is a secondary winding terminal. The metal plate 1 has a winding portion 3 in which a primary winding and a secondary winding are formed of an insulating resin such as an epoxy resin, and a transformer including a transformer core 4a and 4b.
And dissipates heat generated in the transformer. The metal plate 1 is desirably made of a material having good thermal conductivity, and can be manufactured by molding or cutting aluminum or copper. The metal plate 1 has a notch 11 which engages with a locking portion 23 of a leaf spring 2 to be described later, a projection 12 which comes into contact with the molding surfaces 3a and 3b of the winding portion 3, and a hole 13 for screwing.
Are formed. Notch 11 is metal plate 1
Is formed at the edge of. The leaf spring 2 includes a winding part 3 and a transformer core 4.
a and 4b are integrally held on the metal plate 1 and are preferably made of a metal that can withstand the heat generated by the transformer. It is preferable to manufacture spring stainless steel, phosphor bronze, or the like by sheet metal processing. it can. The leaf spring 2 has a bent ceiling portion 22 bent inward, and has L-shaped arms 21 extending from both ends of the bent ceiling portion 22 so as to hold the transformer cores 4a and 4b. A locking portion 23 is formed at the tip of the portion 21. The leaf spring 2 is inserted in the direction of the arrow shown in the perspective view of FIG.
2 presses the center of the transformer core 4a,
21 distal edge engaging portion 23, 23 of the metal plate 1 of
It locks to the notch parts 11 formed in the die. As a result, the winding portions 3 and the transformer cores 4a and 4b are placed on the metal plate 1 so that the molding surfaces 3a and 3b of the winding portions 3
12 and can be fixed. At this time, as shown in FIG. 2, the holding unit 24 holds the transformer cores 4a and 4b so as not to move in the lateral direction. The transformer core 4a,
The contact pressure of the core of 4b including the outer core portions 5a and 5b of the transformer core is independent of the tightening torque of the screws 6a and 6b. FIG. 2 shows an example in which four screws are used. Thus, after the metal plate 1 is fixed to the fixing portion (not shown) by the screws 6a and 6b shown in FIG. 1, even if the tightening torque of the screws 6a and 6b changes, the transformer cores 4a and 6b are changed. The contact pressure of the magnetic path 4b does not change slightly, and the magnetic resistance of the magnetic path does not change. Therefore, even if the screws 6a and 6b are loosened, the characteristics of the transformer do not deteriorate. In addition, since the projection 12 of the metal plate 1 is in contact with the molding surfaces 3a and 3b of the winding 3, heat generated from the primary winding and the secondary winding is good via the projection 12. The heat can be dissipated. The strength of the pressure applied by the leaf spring 2 depends not only on the material, but also on the distance between the bent ceiling 22 and the metal plate 1, the thickness of the leaf spring 2 and the leaf spring. 2, etc., can also be determined. The screw holes 13 provided in the metal plate 1 enable screw mounting. FIG. 3A shows a case where the transformer shown in FIGS. 1 and 2 is mounted on a substrate or the like (not shown) by screws 6a and 6b. As shown in FIG. 3 (B), the screw mounting portion 10-1 shown in FIG. 5 is formed on the leaf spring 10, and when this is mounted on a board or the like, the presence of the screw mounting portion 10-1 causes Even if the transformer shown in FIG. 3B is mounted in close contact with another component A, the peripheral area of the screw mounting portion 10-1 becomes a dead space S, and the mounting density cannot be improved. On the other hand, according to the present invention, the screws 6a, 6b
3A is mounted in the metal plate 1, so that FIG.
As shown in (1), the other components A can be arranged close to this without a dead space, so that the mounting density can be increased. A second embodiment of the present invention will be described with reference to FIG. FIG. 4 shows a case where screws 6a and 6b are mounted on the heat dissipation base plate 7 with screws 6a and 6b in screw holes 13 provided in the metal plate 1. Thereby, heat radiation can be further improved. Note that Japanese Patent Application Laid-Open No. 7-23559 discloses that
A circuit board, a printed coil, and a ferrite core are stacked on a radiating fin to form an inductance or a transformer, but this is not pressed by a leaf spring from the top, causing play at each relative position. Is not stable, and the heat radiation is not sufficient. According to the configuration of the present invention, anyone can assemble with stable pressurization, so that there is little variation during assembling.
In addition, since the inspection can be performed without attaching to the heat dissipation base plate, the number of steps can be reduced. The lock on both arms can be easily released with tweezers or a flathead screwdriver, so disassembly is easy. Furthermore, the hole for screwing is metal
Metal plate adjacent to the protrusion on the diagonal of plate 1
At least two places in the corners of G1 can be screwed
Thus, as shown in FIG. 3, the space can be effectively used so that there is no dead space in the arrangement of the transformer.
Products can be downsized. According to the present invention, the following effects can be obtained. (1) When the leaf spring is locked to the metal plate, the outer legs of the transformer core come into contact with each other, and the protrusion of the metal plate comes into contact with the molding surface of the winding portion. In addition to effectively preventing the characteristic from changing due to the change, the heat generated by the winding portion can be effectively radiated through the protrusion of the metal plate. In addition, since the leaf spring is locked to the metal plate, a fixing screw fixing portion is not required, dead space is eliminated, and when this is incorporated into a product, the mounting density can be increased and the product can be downsized. (2) Since the metal plate can be screwed to the heat dissipation base plate or the like, heat dissipation characteristics can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of an embodiment of the present invention. FIG. 2 is an assembled perspective view of a heat dissipation structure of a transformer according to the present invention. FIG. 3 is a comparison diagram of a mounting space between a heat dissipation structure of a transformer according to the present invention and a conventional structure. FIG. 4 is a perspective view of a second embodiment of the present invention. FIG. 5 is an exploded perspective view of a conventional transformer structure. DESCRIPTION OF SYMBOLS 1 Metal plate 2 Leaf spring 3 Winding part 3a, 3b Molding surface 4a, 4b Trans core 5a, 5b Trans core outer leg part 6a, 6b Screw 7 Heat dissipation base plate 10 Leaf spring 11 Notch 12 Projection Part 13 Screw hole 21 Both arms 22 Bent ceiling part 23 Locking part 24 Holding part 31 Primary winding terminal 32 Secondary winding terminal

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-64436 (JP, A) JP-A-7-153638 (JP, A) JP-A-63-50007 (JP, A) 59825 (JP, U) Actually open 55-74024 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05K 7/20 H01F 27/08-27/26

Claims (1)

(57) [Claims 1] A transformer core having an inwardly bent ceiling so as to pressurize an outer leg thereof, and an L-shape so as to hold the transformer core from both ends of the ceiling. A leaf spring made of an elastic material having both arm portions extending to a notch, and a notch portion in which both arm portions of the leaf spring can be locked is disposed to face the edge, and a protrusion comes into contact with a molding surface of the winding portion. parts are opposed the the Rutotomoni the notch
The projection includes a metal plate arranged on separate sides, and when locking both arms of the leaf spring to the metal plate,
Due to the inwardly bent ceiling, the two outer legs of the transformer core are in pressure contact with each other, the transformer core is held by the both arms, and the projection of the metal plate is formed on the molding surface of the winding part. Contact to improve heat dissipation, and adjacent to the protrusion on the diagonal line of the metal plate
At least two holes in the corners of the metal plate
A transformer heat dissipation structure characterized by improved mounting density by being screwed to a heat dissipation base plate .