JP2011187838A - Mounting structure of transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting structure of a transformer capable of efficiently radiating heat generated in a transformer toward a heat sink by a simple structure. <P>SOLUTION: The transformer 13 transforms (boosts or lowers) a voltage value of an input current from a primary side 13A and outputs it from a secondary side 13B. At the secondary side 13B of the transformer 13, there are formed two first terminals, two second terminals 22a and 22b, and a terminal block 23. At one surface 11a of the heat sink 11, a terminal holder is integrally formed adjacently to a recess to hold the second terminals 22a and 22b. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

   The present invention relates to a transformer mounting structure, and more particularly, to a technique for efficiently mounting a transformer and a heat sink with few parts.

   For example, a switching power supply (DC / DC converter) mounted on an automobile or the like is composed of components such as an IC, a power transformer, a diode, and a transistor. Among the components of these switching power supplies, especially power transformers tend to be used with large capacities corresponding to large currents due to an increase in power used in automobiles. Such a power transformer increases the amount of heat generated as the capacity increases.

   For this reason, power transformers used in conventional switching power supplies generally have a configuration in which a terminal and a heat sink are connected via a terminal block, and heat generated in the power transformer is radiated from the heat sink via the terminal block. Met.

   Further, for example, in Patent Document 1, a terminal portion that is electrically connected to other components and a heat dissipation foot portion branched from the terminal portion are provided and connected to a base plate (heat sink), and heat generated in the coil is generated. An inductance component that radiates heat to the base plate through the heat radiation foot is described.

JP 2004-303823 A

However, in the configuration where heat is radiated from the transformer terminal to the heat sink through the terminal block as described above, a plurality of connection portions such as a connection portion between the terminal and the terminal block and a connection portion between the terminal block and the heat sink are generated. There has been a problem that heat dissipation loss occurs at each stage of the plurality of connection portions, and the heat dissipation efficiency is deteriorated as a whole.
Further, for example, when there are three terminals on the secondary side of the transformer, a large terminal block for receiving these three terminals and an extension terminal for electrically connecting from the terminal block to the components to be connected are separately provided. There is also a problem that the number of components increases and the manufacturing cost increases.

   On the other hand, an inductance component such as that described in Patent Document 1 requires a conductive member having a complicated shape in which a terminal portion and a heat dissipation foot portion are branched, and in the manufacturing process, separately from the connection step of the terminal portion. Since the step of connecting the heat radiation foot to the base plate is required, there is a problem that the manufacturing cost increases.

   Some aspects of the present invention have been made in view of the above circumstances, and provide a transformer mounting structure capable of efficiently dissipating heat generated in a transformer toward a heat sink with a simple configuration. With the goal.

In order to solve the above problems, some aspects of the present invention provide the following transformer mounting structure.
That is, the transformer mounting structure of the present invention is a transformer mounting structure in which a transformer having a plurality of terminals is attached to a heat sink for radiating heat generated in the transformer.
The first terminal and the second terminal constituting the plurality of terminals sandwich the terminal block between different heights in the height direction with respect to one surface of the heat sink, and the first terminal passes through the terminal block and It is connected to a heat sink, and the heat of the first terminal is dissipated to the heat sink via the terminal block, and the second terminal is a terminal holding portion formed integrally with the heat sink, via the first insulating layer. The heat sink is connected to the heat sink, and the heat of the second terminal is directly radiated to the heat sink.

   The tip part of the second terminal only needs to be extended integrally to the outside of the region overlapping the terminal block.

   The second terminal is formed with a hole through which a second screw for directly screwing the second terminal to the heat sink is formed, and the terminal block is insulated to cover the inner peripheral surface of the hole. It is only necessary that the peripheral wall of the sex is formed integrally.

   The terminal block is in contact with the first terminal on the upper surface side in the height direction, and on the lower surface side in the height direction is in contact with the second terminals respectively disposed on both sides of the first terminal. Good.

   The terminal block is provided with a screw hole member for fixing the first terminal with a first screw, and the screw hole member is made of metal for efficiently dissipating heat of the first terminal to the heat sink. It is only necessary that a second insulating layer is formed between the screw hole member and the heat sink.

   The terminal block may be formed by stacking a plurality of the first terminals and screwing the first screw to the screw hole member integrally.

   An extension terminal electrically connected to the electronic component may be integrally screwed to the screw hole member with the first screw on the terminal block.

   According to the transformer mounting structure of the present invention, the second terminal of the transformer is directly attached to the terminal holding portion serving as a terminal block formed integrally with the heat sink via the first insulating layer. It becomes possible to dissipate the heat of the terminal directly to the heat sink. Thus, heat generated in the transformer can be quickly and efficiently radiated toward the heat sink.

   As a terminal block for receiving the second terminal of the transformer, a metal screw hole that receives the second terminal on the terminal block and dissipates heat by forming a terminal holding part that functions as a terminal block integrally with the heat sink. A member etc. become unnecessary. As a result, the terminal block can have a simple configuration, and the manufacturing cost of the switching power supply can be reduced.

   The second screw for screwing the second terminal into the terminal holding part of the heat sink is completely against the second terminal by the first insulating layer and the peripheral wall covering the lower surface of the terminal block and the inner peripheral surface of the hole. Since it is insulated, the insulation of the second terminal with respect to the heat sink can be reliably maintained even if the second terminal is directly connected to the conductive heat sink.

   Moreover, since the front-end | tip part of a 2nd terminal is extended toward the electronic component, extension terminals, such as another metal plate which connects a terminal block and an electronic component, become unnecessary. As a result, the number of components attached to the terminal block can be reduced, and the manufacturing cost of the switching power supply can be reduced.

It is a top view which shows an example of the switching power supply provided with the attachment structure of the transformer of this invention. It is a principal part expansion perspective view which shows the transformer attachment part of FIG. FIG. 2 is an enlarged cross-sectional perspective view near the terminal block of FIG. 1. It is an expanded sectional view of the terminal block vicinity in the AA line of FIG.

   Hereinafter, an embodiment of a transformer mounting structure according to the present invention will be described with reference to the drawings. The present embodiment is specifically described for better understanding of the gist of the invention, and does not limit the invention unless otherwise specified. In addition, in the drawings used in the following description, in order to make the features of the present invention easier to understand, there is a case where a main part is shown in an enlarged manner for convenience, and the dimensional ratio of each component is the same as the actual one. Not necessarily.

FIG. 1 is an overall configuration diagram showing an example of a switching power supply having a transformer mounting structure according to the present invention. FIG. 2 is an enlarged perspective view of a main part showing a transformer mounting portion in FIG. FIG. 3 is an enlarged cross-sectional perspective view of the vicinity of the terminal block of FIG. FIG. 4 is an enlarged cross-sectional view of the vicinity of the terminal block taken along line AA in FIG.
The switching power supply 10 is, for example, a DC / DC converter that is a vehicle-mounted device. The switching power supply 10 includes a heat sink 11 having a substrate function for mounting components. The heat sink 11 is entirely made of a metal excellent in heat dissipation, such as aluminum. Components constituting the switching power supply 10 are mounted on the one surface 11 a side of the heat sink 11. In the following description, a direction perpendicular to the one surface 11a of the heat sink 11 may be referred to as a height direction (reference numeral H in the drawing).

   A transformer 13, an electronic component 16, and the like are mounted on one surface 11 a of the heat sink 11. A recess 28 for receiving the coil main body 13 a of the transformer 13 is formed in a portion where the transformer 13 is provided on the one surface 11 a of the heat sink 11.

   On the other surface 11 b side of the heat sink 11, heat radiation fins 12 made of a large number of plate-like members extending along the height direction H of the heat sink 11 may be formed integrally with the heat sink 11. The heat dissipating fins 12 increase the surface area of the heat sink 11 on the other surface 11b side, so that heat generated by components constituting the switching power supply 10, for example, the transformer 13, can be efficiently dissipated to the outside.

   The transformer 13 transforms (steps up or steps down) the voltage value of the current input from the primary side 13A and outputs it from the secondary side 13B. On the secondary side 13B of the transformer 13, two first terminals 21a and 21b, two second terminals 22a and 22b, and a terminal block 23 are formed. Further, on one surface 11a of the heat sink 11, terminal holding portions 29 and 29 which are formed adjacent to the recess 28 and receive the second terminals 22a and 22b are integrally formed.

   The terminal block 23 is made of, for example, an insulating resin as a whole. The terminal block 23 has a screw hole member 31 inserted in the center portion thereof, a main body portion 23a extending in the height direction H, and wing-like portions 23b and 23b protruding from the vicinity of the upper surface of the main body portion 23a in the lateral direction X. Consists of. The screw hole member 31 is made of a metal having excellent heat conductivity, for example, brass, and a screw hole 31a extending along the height direction H is formed in the center portion. The first screw 33 is screwed into the screw hole 31a.

   A terminal receiving surface 231 c is formed on the top surface of the main body 23 a of the terminal block 23, that is, the portion where the upper surface of the screw hole member 31 is exposed. The first terminals 21a and 21b constituting the transformer 13 extend outward from different height positions in the height direction H of the coil body 13a, and the respective tip portions of the first terminals 21a and 21b are connected to the terminal receiving surface. Bending toward each other toward 231c. And the hole 211a, 211b which penetrates the 1st screw | thread 33 is formed in the front-end | tip part of this 1st terminal 21a, 21b.

   An extension terminal 24 extending toward the electronic component 16 is connected to the terminal receiving surface 231c. A hole 241 a that allows the first screw 33 to pass therethrough is also formed at one end of the extension terminal 24. With such a configuration, on the terminal receiving surface 231c of the terminal block 23, the first terminals 21a and 21b and the extension terminal 24 are screwed in a state where they are overlapped with each other by the first screws 33 that pass through the respective holes 211a, 211b, and 241a. The hole member 31 is fastened together.

   On the other hand, a recess 27 for receiving the main body 23 a of the terminal block 23 is formed between the terminal holding portions 29, 29 formed on the one surface 11 a of the heat sink 11. The screw hole member 31 is exposed on the bottom surface 231a of the main body 23a of the terminal block 23. A second insulating layer 36 is formed between the bottom surface 231 a of the main body 23 a and the bottom surface 27 a of the recess 27 of the heat sink 11. With such a configuration, the first terminals 21 a and 21 b and the extension terminal 24 are connected to the heat sink 11 so as to be able to dissipate heat through the screw hole member 31 while ensuring insulation.

   Holes 231b and 231b through which the second screws 34 and 34 pass are formed in the wing-like portions 23b and 23b of the terminal block 23, respectively. The second terminals 22 a and 22 b constituting the transformer 13 extend between the lower surfaces 232 b and 232 b of the wing-like parts 23 b and 23 b and the terminal holding parts 29 and 29 of the heat sink 11.

   The second terminals 22a and 22b constituting the transformer 13 are arranged so as to sandwich the first terminals 21a and 21b on both sides of the coil body 13a, that is, the secondary side 13B, and overlap the terminal holding portions 29 and 29 of the heat sink 11, respectively. Extend in the direction. In addition, holes 221a and 221b through which the second screws 34 and 34 pass are formed at positions where the second terminals 22a and 22b overlap with the holes 231b and 231b of the terminal block 23, respectively. Insulating peripheral walls 233b and 233b covering the inner peripheral surfaces of the holes 221a and 221b are formed integrally with the terminal block 23 on the lower surfaces 232b and 232b of the wing-like portions 23b and 23b. Furthermore, a first insulating layer 35 is formed between the terminal holding portions 29 and 29 and the second terminals 22a and 22b.

   With such a configuration, the wing-like portions 23 b and 23 b of the terminal block 23 are connected to the terminal holding portions 29 and 29 of the heat sink 11 by sandwiching the second terminals 22 a and 22 b and the first insulating layer 35 with the second screws 34 and 34. 29 is screwed. The second terminals 22a and 22b are connected to the heat sink 11 at the terminal holding portions 29 and 29 so as to be able to directly radiate heat while ensuring insulation.

   That is, the second terminals 22a and 22b are electrically conductive by the lower surfaces 232b and 232b of the wing-like portions 23b and 23b, the peripheral walls 233b and 233b covering the inner peripheral surfaces of the holes 221a and 221b, and the first insulating layers 35 and 35. The second screw 34, 34 is completely covered. As a result, even if the second terminals 22 a and 22 b are screwed into the terminal holding portions 29 and 29 of the heat sink 11 with the second screws 34 and 34, the second terminals 22 a and 22 b are insulative with respect to the heat sink 11. It can be secured. The second terminals 22a and 22b may be integrally extended to the outside of the terminal holding portions 29 and 29, that is, the region overlapping the wing-like portions 23b and 23b of the terminal block 23, and connected to other components. .

   According to the switching power supply 10 having the above-described configuration, the terminal holding portions 29 and 29 that function as a terminal block are integrally formed on the heat sink 11 as terminal blocks for receiving the second terminals 22a and 22b of the transformer 13. A metal screw hole member for receiving the second terminals 22a and 22b on the terminal block 23 and radiating heat to the heat sink 11 is not necessary. As a result, the terminal block 23 can have a simple configuration, and the manufacturing cost of the switching power supply 10 can be reduced.

   In the transformer 13, the second terminals 22a and 22b on the secondary side 13B where a large amount of heat is generated are connected to the terminal holding portions 29 and 29 that function as a terminal block formed integrally with the heat sink 11, with the first insulation. By attaching directly through the layers 35, 35, the heat of the second terminals 22 a, 22 b can be directly radiated to the heat sink 11. As a result, heat generated on the secondary side 13 </ b> B of the transformer 13 can be quickly and efficiently radiated toward the heat sink 11.

   Moreover, the conductive second screws 34 and 34 for screwing the second terminals 22a and 22b to the terminal holding portions 29 and 29 of the heat sink 11 are the lower surfaces 232b and 232b of the wing-like portions 23b and 23b and the holes 221a and 221b. Are completely insulated from the second terminals 22a and 22b by the peripheral walls 233b and 233b covering the inner peripheral surfaces of the first and second insulating layers 35 and 35. Thereby, even if the second terminals 22a and 22b are directly connected to the conductive heat sink 11, the insulation of the second terminals 22a and 22b with respect to the heat sink 11 can be reliably maintained.

   Moreover, since the front-end | tip part of 2nd terminal 22a, 22b is electrically connected to the circuit board and other components which are not shown in figure, another terminal which connects the terminal block 23 and these circuit boards and other components An extension terminal such as a metal plate is also unnecessary.

   On the other hand, the heat of the first terminals 21a and 21b can be efficiently radiated toward the heat sink 11 through the screw hole member 31 made of a metal having excellent heat conductivity. Moreover, since the second insulating layer 36 is formed between the conductive screw hole member 31 and the heat sink 11, the first terminals 21 a and 21 b can be reliably insulated from the heat sink 11. .

   The terminal block 23 is in contact with the first terminals 21a and 21b on the upper surface side in the height direction H, that is, the terminal receiving surface 231c, and on the lower surface side in the height direction H, that is, on the lower surfaces 232b and 232b of the wing portions 23b and 23b. It contacts the second terminals 22a and 22b arranged on both sides of the one terminal 21a and 21b, respectively. Accordingly, the terminal block 23 is sandwiched between the first terminals 21a and 21b and the second terminals 22a and 22b in the height direction H between different heights.

   For this reason, it is possible to easily attach the transformer 13 when the switching power supply 10 is manufactured by sandwiching the terminal block 23 between the first terminals 21a and 21b and the second terminals 22a and 22b in advance. become. Moreover, the terminal block 23 is configured such that the peripheral walls 233b and 233b protruding from the lower surfaces 232b and 232b of the wing-like portions 23b and 23b are engaged with the holes 221a and 221b of the second terminals 22a and 22b. Positioning during assembly with respect to can be easily performed.

   Furthermore, since the terminal block 23 receives the main body 23a of the terminal block 23 by the recess 27 formed between the terminal holding portions 29, 29, the terminal block 23 can be stably attached to the heat sink 11. .

   In the above-described embodiment, the terminals extending from the secondary side 13B of the transformer 13 are the four terminals of the first terminals 21a and 21b and the second terminals 22a and 22b. However, the present invention is not limited to this. is not. For example, the present invention can be applied to a transformer having an arbitrary configuration, such as a transformer having one first terminal and two second terminals on the secondary side, or a transformer having one first terminal and one second terminal.

   In the above-described embodiment, the end portions of the first terminals 21 a and 21 b and the electronic component 16 are connected by the extension terminal 24, but the first terminal 21 a or the first terminal 21 b is further connected from the terminal block 23. It is possible to extend and connect the first terminals 21a and 21b directly to other components. Accordingly, it is possible to reduce the manufacturing cost of the switching power supply 10 by eliminating the extension terminal 24 and further reducing the number of components.

   In the embodiment described above, the transformer mounting structure of the present invention is applied to the secondary side 13B of the transformer 13 where a large amount of heat is generated. However, the present invention is not limited to this, and the transformer 13 It is also preferable to apply the above-described transformer mounting structure to the primary side 13A.

DESCRIPTION OF SYMBOLS 10 ... Switching power supply, 11 ... Heat sink, 13 ... Transformer, 21a, 21b ... First terminal, 22a, 22b ... Second terminal, 23 ... Terminal block, 29 ... Terminal holding part, 35 ... First insulating layer, 233b, 233b ... A peripheral wall.

Claims (7)

A transformer mounting structure in which a transformer having a plurality of terminals is attached to a heat sink for radiating heat generated in the transformer,
The first terminal and the second terminal constituting the plurality of terminals sandwich the terminal block between different heights in the height direction with respect to one surface of the heat sink,
The first terminal is connected to the heat sink via the terminal block, and the heat of the first terminal is radiated to the heat sink via the terminal block.
The second terminal is a terminal holding part formed integrally with the heat sink, and is connected to the heat sink via a first insulating layer, and the heat of the second terminal is directly radiated to the heat sink. Transformer mounting structure.    2. The transformer mounting structure according to claim 1, wherein a tip end portion of the second terminal is integrally extended to the outside of a region overlapping with the terminal block.    The second terminal is formed with a hole through which a second screw for directly screwing the second terminal to the heat sink is formed, and the terminal block is insulated to cover the inner peripheral surface of the hole. The transformer mounting structure according to claim 1, wherein the peripheral wall is integrally formed.    The terminal block is in contact with the first terminal on the upper surface side in the height direction, and is in contact with the second terminal disposed on both sides of the first terminal on the lower surface side in the height direction. The transformer mounting structure according to any one of claims 1 to 3.    The terminal block is provided with a screw hole member for fixing the first terminal with a first screw, and the screw hole member is made of metal for efficiently dissipating heat of the first terminal to the heat sink. The transformer mounting structure according to claim 1, wherein a second insulating layer is formed between the screw hole member and the heat sink.    6. The transformer according to claim 1, wherein the terminal block is configured such that a plurality of the first terminals are overlapped and screwed together to the screw hole member with the first screw. Mounting structure. The extension terminal electrically connected to the electronic component is screwed integrally to the screw hole member with the first screw on the terminal block. The transformer mounting structure described in the section.

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