CN210157083U

CN210157083U - Power conversion device

Info

Publication number: CN210157083U
Application number: CN201890000510.0U
Authority: CN
Inventors: 一瀬笃史
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2017-04-28
Filing date: 2018-04-20
Publication date: 2020-03-17
Anticipated expiration: 2028-04-20
Also published as: JP2018191388A; WO2018198953A1

Abstract

The power conversion device includes a circuit board, an electrical component, a heat sink, a box-shaped case, and a sealing member. The electric component is mounted on the circuit board. The heat sink has a component mounting portion on which an electrical component is mounted and a heat dissipating portion that dissipates heat generated by the electrical component. The case is configured as a member separate from the heat sink, and houses the heat sink and the electric component. An opening is arranged on the shell. The sealing member is disposed between the heat sink and the case. The heat sink is attached to the housing with the heat dissipation portion exposed to the outside through the opening of the housing.

Description

Power conversion device

Technical Field

The present disclosure relates to a power conversion device, and more particularly, to a power conversion device suitable for vehicle mounting.

Background

An environmentally friendly vehicle such as an electric vehicle is equipped with a power conversion device such as a charger, an inverter, and a DC-DC converter. The power conversion device includes electric components such as a power semiconductor element that generate heat when energized. Generally, the electrical components are thermally connected to a heat sink (heat radiation member) for efficiently radiating generated heat to the outside. Patent documents 1 and 2 disclose a structure in which a heat sink made of a member separate from a case is attached to an opening formed in the case and is thermally connected to an electrical component.

In addition, in many power conversion devices, the housing is manufactured by die-casting from the viewpoint of water resistance, heat radiation, vibration resistance, and the like. Since die-casting can be performed to a complicated shape and has high dimensional accuracy, the heat sink and the housing can be integrally formed. In patent documents 1 and 2, the case and the heat sink are formed of separate members, but in this case, the case and the heat sink are also manufactured by die-casting.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2001-168560

Patent document 2: japanese patent laid-open publication No. 2013-162017

SUMMERY OF THE UTILITY MODEL

Even if the types (vehicle types) of vehicles on which the power conversion device is mounted are different, the electric circuit and the electric components housed inside the power conversion device do not change greatly. However, the mounting position of the power converter varies depending on the vehicle type, and the required outer dimensions and shapes vary. Therefore, at least the housing of the power conversion apparatus is developed for each vehicle type.

However, the die-casting requires a long time to design and manufacture the die, and the die is expensive. Therefore, designing for each vehicle model leads to an increase in development cost. In addition, even if the design such as the layout of the electrical components is changed in the development stage, the development cost is increased because the mold is newly manufactured. As described above, in the conventional power conversion device, since the housing is formed by die-casting, it is difficult to reduce the cost.

The present disclosure provides a power conversion device that can easily cope with design changes and can achieve cost reduction.

A power conversion device according to an embodiment of the present disclosure includes a circuit board, an electrical component, a heat sink, a box-shaped case, and a sealing member. The electric component is mounted on the circuit board. The heat sink has a component mounting portion on which an electrical component is mounted and a heat dissipation portion. The case is a member separate from the heat sink, and houses the heat sink and the electric component. An opening is arranged on the shell. The sealing member is disposed between the heat sink and the case. The heat sink is attached to the housing with the heat dissipation portion exposed to the outside through the opening of the housing.

Preferably, the housing is formed of a metal plate.

Preferably, the housing is made of resin.

Preferably, the heat sink is a die-cast product.

Preferably, a groove for disposing the sealing member is provided in the heat sink.

Preferably, the power conversion device further includes a biasing member that presses and fixes the electrical component to the component placement unit.

Preferably, the urging member is a plate spring, and the heat sink has a positioning pin and a screw hole.

Preferably, the electric component includes a power semiconductor element that generates heat when energized.

According to the present disclosure, a power conversion device that can easily cope with design changes and can achieve cost reduction is provided.

Drawings

Fig. 1A is a top perspective view illustrating an appearance of a charger as an example of a power conversion device according to an embodiment of the present disclosure.

Fig. 1B is a bottom perspective view of the charger shown in fig. 1A.

Fig. 2 is a diagram showing a state in which the circuit board is detached from the charger shown in fig. 1A.

Fig. 3 is an exploded perspective view of the charger shown in fig. 1A, which shows a state viewed from above.

Fig. 4 is an exploded perspective view showing a state in which the charger shown in fig. 3 is viewed from below.

Fig. 5A is a perspective view showing a state in which an electrical component (FET) is mounted to the heat sink shown in fig. 3, and shows a state viewed from above.

Fig. 5B is a perspective view showing a state where the heat sink and the electric component (FET) shown in fig. 5A are viewed from below.

Fig. 6 is an exploded perspective view illustrating the structure of the heat sink and the electrical component (FET) illustrated in fig. 5A.

Fig. 7 is a sectional view of a portion where a heat sink and an electric component (FET) are arranged in the charger shown in fig. 1A.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

Fig. 1A and 1B are diagrams showing an external appearance of a charger 1 as an example of a power conversion device according to an embodiment of the present disclosure. Fig. 1A is a perspective view of the charger 1 as viewed from above, and fig. 1B is a perspective view of the charger 1 as viewed from below. Fig. 2 is a diagram showing a state of the charger 1 with the circuit board 40 removed. Fig. 3 is an exploded perspective view of the charger 1 as viewed from above. Fig. 4 is an exploded perspective view of the charger 1 as viewed from below. In fig. 3 and 4, the electric component 41 mounted on the upper surface of the circuit board 40 and the boss 14 provided upright on the case 10 are omitted.

As shown in fig. 1A, 1B, 2, and 3, the charger 1 includes a case 10, a heat sink 20, an electric component 30, a circuit board 40, and the like.

The circuit board 40 is a printed circuit board on which a predetermined circuit pattern is formed. The circuit board 40 is provided to face the bottom surface of the case 10. The

electrical components

30 and 41 are mounted on the circuit board 40. The electric component 30 is mounted on the lower surface (the surface facing the case 10) of the circuit board 40 to dissipate heat. The electrical components 41 include, for example, a film capacitor and a relay. The electric component 41 is mounted on the upper surface of the circuit board 40 because of its low necessity of heat dissipation.

The electric component 30 is a component that generates heat by itself when energized, and includes, for example, power semiconductor elements (so-called power semiconductors) such as field effect transistors (fet) 30B and 30C, a diode 30D, and a bridge diode 30E, a coil 30F, a transformer 30A, and the like. As the power semiconductor elements,

FETs

30B and 30C, a diode 30D, and a bridge diode 30E, standardized general-purpose products can be applied.

The lead portion 32 of the electrical component 30 is electrically connected to a circuit pattern (not shown) of the circuit board 40 (see fig. 5A). The heat radiation surface 31a of the electrical component 30 is thermally connected to the component mounting surface 21a of the heat sink 20 (see fig. 6). An insulating sheet 54 is provided between the power semiconductor elements FET30B and FET30C, diode 30D, and heat sink 20.

The heat sink 20 thermally contacts the electrical component 30 and radiates heat generated by the electrical component 30 to the outside. That is, the heat sink 20 includes heat sinks 20A to 20F, and the heat sinks 20A to 20F are provided corresponding to the transformers 30A, FET30B, 30C, the diode 30D, the bridge diode 30E, and the coil 30F, which are electrical components, respectively. Heat sinks 20A to 20E corresponding to transformers 30A, FET30B and 30C, diode 30D, and bridge diode 30E are mounted to case 10 from the inside (upper side in fig. 3 and 4) of case 10. The heat sink 20F corresponding to the coil 30F is attached to the case 10 from the outside (lower side in fig. 3 and 4) of the case 10. The heat sink 20 is not particularly limited as to whether it is attached to the housing 10 from the inside or the outside.

The heat sink 20 is preferably formed by die-casting. That is, the heat sink 20 is preferably a die-cast product. This enables the heat sink 20 to be manufactured with high accuracy even if it has a complicated shape. In addition, when the heat sinks 20 are mass-produced, cost reduction can be achieved. Further, compared to the case where the housing and the heat sink are integrally formed by die-casting as in the related art, the cost required for die-casting is reduced because the die is smaller. A specific fixing structure of the electric component 30 and the heat sink 20 will be described later.

The case 10 is a box-shaped member that houses the heat sink 20, the electrical component 30, and the circuit board 40. The case 10 is formed by performing sheet metal working including punching, bending, and drawing on a plate material (for example, a steel plate) made of a metal material. That is, the housing 10 is a sheet metal processed product made of a metal plate. In general, sheet metal working can be performed at a lower cost than die-casting.

The case 10 has a recess 11 for accommodating the transformers 30A, FET30B and 30C, the diode 30D, the bridge diode 30E, the coil 30F, the circuit board 40, and the like as electrical components. A flange 12 protruding outward is formed on the upper edge of the concave chamber 11. A lid (not shown) having a shape symmetrical to the case 10 so as to cover the opening surface of the recess 11 is attached to the case 10. For example, the flange 12 of the case 10 and a flange (not shown) of the lid are overlapped and screwed to fix both.

The housing 10 has an opening 13 in the bottom surface of the recess 11. The opening 13 is provided corresponding to the heat sinks 20A to 20F (openings 13A to 13E). The heat dissipation portion 22 (see fig. 5B) of the heat sink 20 is exposed to the outside of the case 10 through the opening 13. On the other hand, the component mounting portion (see the component mounting portion 21 in fig. 5A) of the heat sink 20 on which the transformers 30A, FET30B, 30C, the diode 30D, the bridge diode 30E, and the coil 30F are mounted is disposed inside the recess 11 of the case 10. The recess 11, the flange 12, and the opening 13 can be easily formed by sheet metal working. Since the case 10 is formed by sheet metal working, it is possible to easily cope with the change in design (for example, the size and shape of the case 10, and the position of the opening 13 (in other words, the mounting positions of the transformers 30A, FET30B and 30C, the diode 30D, the bridge diode 30E, and the coil 30F, respectively)) and the like at low cost.

Further, a boss 14 (see fig. 2) having a screw hole for fixing the heat sink 20 and the like is provided upright on the bottom surface of the case 10. The projection 14 is formed on the bottom surface of the recess 11 by, for example, welding. Although not shown, screw holes through which screws (reference numerals are omitted, see fig. 1B) for fixing the heat sink 20 are inserted are formed in the bottom surface of the housing 10.

Hereinafter, a fixing structure of the heat sink 20 and the electric component 30 will be described by taking the FET30B as an example. Fig. 5A and 5B are diagrams showing a state in which the FET30B is mounted on the heat sink 20B. Fig. 6 is an exploded perspective view showing the structure of the heat sink 20B and the FET 30B. Fig. 7 is a sectional view of a portion of the charger 1 where the heat sink 20 and the FET30B are arranged. In fig. 5A, 5B, 6, and 7, the insulating sheet 54 (see fig. 3) is omitted.

As shown in fig. 5A, 5B, 6, and 7, 4 FETs 30B are provided side by side, and the 4 FETs 30B are fixed to the 1 heat sink 20B by being pressed by the biasing member 51.

The FET30B is a general-purpose transistor of the lead-in type, and has a package portion 31 and a lead portion 32. One main surface of the sealing portion 31 is a diffusion surface 31 a. The lead portion 32 extends from the sealing portion 31 in a bent state, and is connected to the circuit board 40 by, for example, soldering.

The heat sink 20B includes a component mounting portion 21, a heat dissipation portion 22, a fixing portion 23, a flange 24, and a groove 25.

The component mounting portion 21 mounts the FET30B thereon, and has a function of transferring heat generated by the FET30B to the heat dissipation portion 22. The component mounting portion 21 has a component mounting surface 21a on which the FET30B is mounted. The component mounting surface 21a is inclined with respect to the substrate surface of the circuit substrate 40. By inclining the component mounting surface 21a, the area of the bottom surface of the recess 11 can be reduced as compared with the case where the component mounting surface 21a is made parallel to the substrate surface of the circuit substrate 40, but the component mounting surface 21a may be made parallel to the substrate surface.

The heat dissipation portion 22 is provided on the surface of the component mounting portion 21 opposite to the component mounting surface 21 a. The heat dissipation portion 22 dissipates heat generated by the FETs 30B. The heat dissipation portion 22 has plate-shaped heat dissipation fins (reference numerals are omitted). The shape of the fins is not particularly limited, and may be, for example, a needle shape.

The fixing portion 23 has a positioning pin 23a and a screw hole 23 b. The urging member 51 is fixed to the fixing portion 23. The flange 24 is formed to protrude outward from the component mounting portion 21 and the fixing portion 23. The flange 24 is provided with a threaded hole 26 for screw-fastening to the housing 10.

The groove 25 is provided along the outer periphery on the lower surfaces of the component mounting portion 21, the fixing portion 23, and the flange 24, i.e., the surfaces that contact the housing 10. A seal member 53 (see fig. 7) is disposed in the groove 25.

In this way, the heat sink 20B includes the component mounting portion 21, the heat dissipation portion 22, the fixing portion 23, the flange 24, and the groove 25, which are complicated shapes. That is, by concentrating the structure that is difficult to manufacture by sheet metal working on the heat sink 20, the case 10 can be formed by a low-cost manufacturing method such as sheet metal working without including a complicated structure in the case 10.

Further, the heat sink 20 can be formed by die-casting. In particular, by integrally forming the component mounting portion 21 and the heat dissipation portion 22, higher heat transfer performance and heat dissipation performance can be achieved.

The urging member 51 has 4 leaf springs 51a and a connecting portion 51b connecting the leaf springs 51 a. The coupling portion 51B has through holes (reference numerals are omitted) through which the screws 52 pass, and through holes 51c through which the positioning pins 23a of the heat sink 20B pass.

The FET30B is mounted on the component mounting portion 21 so that a heat radiation surface (reference numeral omitted) of the package portion 31 is in surface contact with the component mounting surface 21 a. In this state, the biasing member 51 is attached to the heat sink 20B. Specifically, the biasing member 51 is positioned by the positioning pin 23a penetrating the heat sink 20B through the through hole 51 c. Then, the screw 52 is screwed into the screw hole 26 of the heat sink 20B through the through hole (not shown), thereby fixing the biasing member 51. At this time, the plate spring 51a is in a state of pressing the fet30B toward the heat sink 20B. That is, 4 FETs 30B are collectively pressed and fixed to the heat sink 20B. The lead portion 32 of the FET30B is electrically connected to a circuit pattern (not shown) of the circuit board 40 by, for example, soldering. The FET30B is mounted in a state of being inclined with respect to the circuit substrate 40.

Since the FET30B is mounted obliquely with respect to the circuit board 40, the FET30B can be pressed and fixed by the urging member 51 without increasing the space between the case 10 and the circuit board 40, and the insulation distance can be secured. Further, since the FET30B is fixed to the heat sink 20B by pressing, the contact thermal resistance is reduced, the heat radiation efficiency is improved, and the vibration resistance is also improved. Further, since a standardized general-purpose product is used as the FET30B, cost reduction can be achieved.

The heat sink 20B is attached to the housing 10 in a state where the heat dissipation portion 22 is exposed to the outside through the opening 13 formed in the housing 10 (see fig. 7). Specifically, the heat sink 20B is fixed to the case 10 by screwing screws (reference numerals are omitted, see fig. 2) from the outside of the case 10 into screw holes 26 provided in the flange 24. At this time, the sealing member 53 is disposed in the groove 25 of the heat sink 20B. Thereby, since the case 10 and the heat sink 20B are fixed watertightly, the waterproof property of the charger 1 is ensured. Further, an O-ring, a liquid gasket, or the like can be applied as the sealing member 53.

The structure of the heat sink 20B and the FET30B has been described as an example, and the basic parts of the

other heat sinks

20A and 20C to 20F and the structures of the transformer 30A, FET30C, the diode 30D, the bridge diode 30E, and the coil 30F are also the same. Further, when the heat sink 20F is attached to the housing 10 from the outside, the groove 25 in which the sealing member 53 is disposed is formed on the upper surface.

In this way, the charger 1 (power conversion device) includes the circuit board 40, the electrical component 30 mounted on the circuit board 40, the heat sink 20 having the component mounting portion 21 on which the electrical component 30 is mounted and the heat dissipation portion 22 that dissipates heat generated by the electrical component 30, the box-shaped case 10 that houses the heat sink 20 and the electrical component 30, and the sealing member 53 provided between the heat sink 20 and the case 10. The case 10 is formed of a member separate from the heat sink 20. The heat sink 20 is attached to the housing 10 in a state where the heat dissipation portion 22 is exposed to the outside from the opening 13 formed in the housing 10.

In the charger 1, the case 10 and the heat sink 20 are formed as separate members, and the case 10 is formed by sheet metal working, so that even if the specifications (for example, the outer dimensions and the shape) required for the charger 1 are different, the design of the case 10 can be changed only, and the heat sink 20 can be shared regardless of the design of the case 10. In addition, even if a design change such as a layout of the electrical component 30 is performed in a development stage, the design of the housing 10 can be changed to easily cope with the change. Therefore, according to the charger 1, it is possible to easily cope with the design change, and it is possible to reduce the cost.

In general, even if the vehicle type on which the charger 1 is mounted differs, the circuit board 40 and the electric components 30 housed inside the charger 1 do not change greatly. Therefore, the radiator 20 and the electric component 30 can be expected to be commonly used in a plurality of vehicle types. Therefore, according to the charger 1, it is possible to expand to a plurality of vehicle models and further reduce the cost.

The present disclosure has been specifically described above based on the embodiments, but the present disclosure is not limited to the above embodiments and may be modified within a range not departing from the gist thereof.

In the present embodiment, the charger 1 has been described as the power conversion device, but the above-described structure may be applied to other vehicle-mounted power conversion devices such as an inverter and a DC-DC converter.

The heat sink 20 may be manufactured by a manufacturing method other than die-casting, and forging or extrusion molding may be applied. In addition, for example, a groove for disposing the sealing member 53 may be formed in the case 10 instead of the heat sink 20.

The housing 10 may be manufactured by a manufacturing method other than sheet metal working. For example, the case 10 can be manufactured by resin molding. That is, the housing 10 may be a resin molded product.

It should be understood that the above embodiments are illustrative in all respects and not restrictive. The scope of the disclosure is indicated by the claims rather than the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Industrial applicability

The power conversion device according to the present disclosure is suitable for use in a vehicle-mounted power conversion device such as a charger, an inverter, or a DC-DC converter.

Description of the reference numerals

1: a charger (power conversion device); 10: a housing; 12. 24: a flange; 13. 13A, 13B, 13C, 13D, 13E, 13F: an opening; 14: a protrusion; 20. 20A, 20B, 20C, 20D, 20E, 20F: a heat sink; 21: a component mounting part; 21 a: a component mounting surface; 22: a heat dissipating section; 23: a fixed part; 23 a: positioning pins; 23b, 26: a threaded hole; 25: a groove; 30. 41: an electrical component; 30A: a transformer; 30B, 30C: a Field Effect Transistor (FET); 30D: a diode; 30E: a bridge diode; 30F: a coil; 31: a packaging section; 31 a: a heat dissipating surface; 32: a lead part; 40: a circuit substrate; 51: a force application member; 51 a: a plate spring; 51 b: a connecting portion; 51 c: a through hole; 52: a screw; 53: a sealing member; 54: an insulating sheet.

Claims

1. A power conversion device is characterized by comprising:

a circuit substrate;

an electric component mounted on the circuit board;

a heat sink having a component mounting portion on which the electrical component is mounted and a heat dissipating portion;

a box-shaped case configured as a member separate from the heat sink, housing the heat sink and the electric component, and having an opening; and

a sealing member disposed between the heat sink and the case,

wherein the heat sink is attached to the housing in a state where the heat dissipation portion is exposed to the outside from the opening of the housing.

2. The power conversion apparatus according to claim 1,

the housing is formed of a metal plate.

3. The power conversion apparatus according to claim 1,

the housing is made of resin.

4. The power conversion apparatus according to claim 1,

the radiator is a die-casting forming product.

5. The power conversion apparatus according to claim 1,

a groove for disposing the sealing member is provided to the heat sink.

6. The power conversion apparatus according to claim 1,

the power conversion device further includes a biasing member that presses and fixes the electrical component to the component placement unit.

7. The power conversion apparatus according to claim 6,

the force-applying member is a plate spring,

the radiator is provided with a positioning pin and a threaded hole.

8. The power conversion apparatus according to claim 1,

the electric component includes a power semiconductor element that generates heat by energization.

9. The power conversion apparatus according to claim 4,

a groove for disposing the sealing member is provided to the heat sink.

10. The power conversion apparatus according to claim 9,