JP6458575B2 - Power converter - Google Patents

Description

  The present invention relates to a power converter, and more particularly to a cooling structure for a capacitor mounted on a circuit board.

  In power converters in which a large-capacity capacitor is mounted on a circuit board, various cooling structures are provided in order to prevent the influence of heat generated from the capacitor. For example, in Patent Document 1, a hole through which a capacitor passes is formed in a housing case that covers a circuit board, and the capacitor is disposed outside the housing case. A cap member that covers the periphery of the capacitor is attached to the hole of the housing case. This cap member prevents water and dust from entering through a hole formed in the housing case. According to this power conversion device, the heat generated from the capacitor is released to the outside of the housing case through the entire surface of the cap member, and the cooling performance can be improved.

JP 2000-173861 A

  Incidentally, in the above-described cooling structure, it is necessary to prepare a cap member according to the number of capacitors mounted on the circuit board. In addition, a seal member must be interposed between the cap member and the housing case. For this reason, there is a problem that not only the number of handling parts increases, but also the assembly work of the power conversion device may be complicated.

  In view of the above circumstances, an object of the present invention is to provide a power conversion device capable of improving the cooling performance of a capacitor without incurring the problem of increasing the number of parts and the problem of complicated assembly work. .

  To achieve the above object, a power conversion device according to the present invention is a power conversion device in which a circuit board on which a capacitor is mounted is housed in a housing case, wherein the housing case faces a capacitor mounting surface of the circuit board. A main cover portion arranged in a manner that protrudes to the outside in a portion corresponding to the capacitor in the main cover portion, and a capacitor accommodating portion for accommodating the capacitor therein, the main cover portion The capacitor housing portion is integrally formed.

  According to the present invention, in the above-described power conversion device, a ventilation fan configured to form a ventilation passage at a position surrounding the capacitor housing portion outside the housing case and ventilate from one of the ventilation passages to the other is provided. It is characterized by being arranged.

  Further, the present invention provides the above-described power converter, wherein the capacitor housing portion is formed in an elliptical column shape, and a plurality of capacitors mounted on the circuit board in a manner along the ventilation direction of the ventilation passage are provided inside the capacitor housing portion. It is characterized by having been accommodated in.

  Moreover, the present invention is characterized in that, in the above-described power converter, the capacitor housing portion has a vent hole communicating with the outside of the housing case, and the vent hole is covered with a moisture-permeable waterproof sheet. To do.

  According to the present invention, since the main cover portion and the capacitor housing portion of the housing case are integrally formed, the number of components does not increase regardless of the number of capacitors mounted on the circuit board. In addition, there is no need to provide a seal member between the main cover portion and the capacitor housing portion. Therefore, it is possible to improve the cooling performance of the capacitor without incurring the problem of increasing the number of parts and the problem of complicated assembly work.

FIG. 1 is a perspective view showing an appearance of a power conversion device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a main part of the power conversion device shown in FIG. FIG. 3 is a cross-sectional side view of the power conversion device shown in FIG. 1. 4 is a partially cutaway plan view of the power conversion device shown in FIG. FIG. 5 is a perspective view of a circuit board applied to the power converter shown in FIG. FIG. 6 is a perspective view of the second case portion constituting the housing case of the power conversion device shown in FIG. 1. FIG. 7 is a perspective view of a frame member constituting the ventilation portion of the power conversion device shown in FIG. 1. FIG. 8 is a perspective view of a second case portion applied to the power conversion device that is Modification 1 of the present invention. FIG. 9 is a perspective view of a second case portion of a circuit board applied to the power conversion device shown in FIG. FIG. 10 is a cross-sectional view of a main part of a power converter that is a second modification of the present invention. FIG. 11 is a perspective view showing a part of the main part of the power converter shown in FIG.

  Hereinafter, preferred embodiments of a power converter according to the present invention will be described in detail with reference to the accompanying drawings.

  1 to 4 show a power conversion apparatus according to an embodiment of the present invention. The power conversion device 1 exemplified here is for supplying an AC voltage supplied from a commercial power source to a desired frequency / amplitude and then supplying it to a load such as a motor, and a housing case for housing the circuit boards 2A and 2B. 10, and a ventilation module 20 for cooling the semiconductor module 3 such as an IGBT and the capacitor 4 that are components of the power conversion device 1.

  The housing case 10 includes a first case portion 11 and a second case portion 12. The 1st case part 11 comprises a part of outline of the power converter device 1, and is comprised so that the substantially rectangular flat plate shape may be comprised with a resin material. On the inner surface side of the first case portion 11, two circuit boards 2A and 2B having different sizes are supported in a stacked state. As shown in FIGS. 2 to 5, a circuit board having a large outer dimension (hereinafter referred to as a main circuit board 2 </ b> A) is configured in a rectangular shape slightly smaller than the first case part 11. It is arrange | positioned facing the inner surface. A circuit board having a small outer dimension (hereinafter referred to as a sub circuit board 2B) has a width approximately ½ that of the first case part 11, and is the right half of the first case part 11 in FIG. It is arranged in the part. On the sub circuit board 2B, the heat generating components such as the semiconductor module 3 and the capacitor 4 described above are mainly mounted. Although not clearly shown in the figure, the main circuit board 2A and the sub circuit board 2B are electrically connected to each other to form a control circuit necessary for power conversion.

  As shown in FIG. 5, the semiconductor module 3 applied in the present embodiment has a substantially rectangular parallelepiped shape, and has screw fastening portions 3a on upper and lower side surfaces that are parallel to each other. The screw fastening portion 3a is a tongue-like portion protruding from an edge located on the side of the heat radiating surface 3b separated from the sub circuit board 2B on the side surface of the semiconductor module 3. Each screw fastening portion 3a is provided with a screw insertion hole 3c through which the attachment screw B is inserted. In the main circuit board 2A and the sub circuit board 2B, through holes 2a are formed in portions facing the screw insertion holes 3c of the semiconductor module 3, respectively. The through-hole 2a is a circular opening having an inner diameter larger than that of the screw insertion hole 3c.

  The capacitor 4 has a cylindrical shape, and is mounted on the sub circuit board 2B with one end face thereof facing the mounting surface 2Ba of the sub circuit board 2B. In the present embodiment, capacitors 4 are respectively disposed at the upper left corner and the lower right corner of the upper end of the sub circuit board 2B.

  As shown in FIGS. 2 to 4 and 6, the second case portion 12 is a resin molded product having a size that covers the first case portion 11, and includes a main cover portion 12 a and a capacitor housing portion 12 b. ing. The main cover portion 12a is a plate-like portion that is disposed to face the mounting surfaces 2Aa and 2Ba of the circuit boards 2A and 2B. The capacitor accommodating portion 12b is for individually accommodating the individual capacitors 4 mounted on the sub circuit board 2B, and is integrally formed with the main cover portion 12a so as to protrude outward from the main cover portion 12a. In the present embodiment, the capacitor housing portion 12b is configured so as to be a bottomed cylindrical sealed container having an opening only at a portion facing the mounting surface 2Ba of the sub circuit board 2B. The size of the capacitor accommodating portion 12b is set so that a gap of 0.5 mm is formed between the end surface and the peripheral surface of the capacitor 4 when the capacitor 4 is accommodated therein.

  Further, the main cover portion 12 a of the second case portion 12 is provided with a communication hole 12 c at a portion corresponding to the semiconductor module 3. The communication hole 12c is a substantially rectangular opening having an outer shape smaller than a heat receiving surface 30a of the heat sink 30 described later, while allowing the semiconductor module 3 to be inserted therethrough. Around the communication hole 12c, a seal groove 12d is provided on the back side that is not opposed to the first case portion 11. The seal groove 12 d is a recess for accommodating the endless seal material 13.

  As is apparent from FIG. 2, the second case portion 12 has a partition wall portion 12e so that the back surface is divided into left and right parts, and at the upper edge of the right half in FIG. A ventilation plate portion 12f is provided. The partition wall portion 12 e is a flat plate member that is erected so as to be substantially orthogonal to the first case portion 11. The ventilation plate portion 12f is a flat plate member having a large number of ventilation holes 12g, and is provided so as to cover the upper right half of the second case portion 12 in FIG.

  The ventilation portion 20 includes a frame member 40 configured to surround the second case portion 12, and constitutes a ventilation passage 21 along the vertical direction between the second case portion 12 and the frame member 40. . The upper end opening of the ventilation passage 21 is covered with the ventilation plate portion 12 f provided in the second case portion 12. The frame member 40 is formed of a high thermal conductive material having good thermal conductivity such as aluminum or aluminum alloy. As shown in FIGS. 2 and 4, the main plate portion 41, the side plate portion 42, and the auxiliary side plate portion 43 are formed. have. The main plate portion 41 has an outer dimension that can cover a portion of the second case portion 12 that is located on the right side of the partition wall portion 12e. A large number of fin fitting grooves 41a are provided on the inner surface of the main plate portion 41 facing the second case portion 12 along the vertical direction. The side plate portion 42 is a portion extending from the one edge portion of the main plate portion 41 toward the second case portion 12 in a substantially right angle direction. The side plate portion 42 is configured to be disposed to face the partition wall portion 12 e of the second case portion 12 when the main plate portion 41 is opposed to the second case portion 12. The auxiliary side plate portion 43 is a portion extending from the other edge portion of the main plate portion 41 toward the second case portion 12 in a substantially perpendicular direction. As is clear from the drawing, the auxiliary side plate portion 43 is configured so that the extension length from the main plate portion 41 is smaller than that of the side plate portion 42. The auxiliary side plate portion 43 is configured to overlap the partition wall portion 12e when the main plate portion 41 is opposed to the second case portion 12.

  A ventilation fan 50 and a heat sink 30 are provided on the inner surface of the frame member 40. The ventilation fan 50 is arrange | positioned in the lower end part of the inner surface in the frame member 40, as shown in FIG. When driven, the ventilation fan 50 introduces external air into the ventilation passage 21 through the ventilation holes 12g of the ventilation plate portion 12f, and operates to discharge the air in the ventilation passage 21 from the opening at the lower end. Is.

  As with the frame member 40, the heat sink 30 is formed of a highly thermally conductive material having good thermal conductivity such as aluminum or aluminum alloy. In the present embodiment, a heat sink 30 having a flat heat receiving surface 30a on one surface of the base member and a plurality of cooling fins 30b standing on the other surface is applied. The heat receiving surface 30 a of the heat sink 30 is configured in a rectangular shape having a size capable of coming into contact with the entire circumference of the sealing material 13 accommodated in the sealing groove 12 d of the second case portion 12. The heat sink 30 is attached to the frame member 40 in a state where it is thermally connected to the frame member 40 by fitting the front end portions of the cooling fins 30b into the fin fitting grooves 41a of the main plate portion 41, respectively. The position where the heat sink 30 is attached to the frame member 40 is such that when the main plate portion 41 faces the second case portion 12, the communication hole 12c of the second case portion 12 is covered and the peripheral edge portion of the heat receiving surface 30a is sealed. This is the position where the entire circumference of the material 13 faces.

  As shown in FIG. 7, the heat receiving surface 30 a of the heat sink 30 is provided with a pair of screw fastening holes 31. The screw fastening holes 31 are provided corresponding to the screw insertion holes 3 c of the screw fastening portions 3 a provided in the semiconductor module 3. As shown in FIG. 3, the screw fastening hole 31 of the heat sink 30 has a mounting screw B through the through hole 2a of the main circuit board 2A, the through hole 2a of the sub circuit board 2B, and the screw insertion hole 3c of the semiconductor module 3. It is concluded. The mounting screw B has a function of bringing the heat radiation surface 3b of the semiconductor module 3 into close contact with the heat reception surface 30a of the heat sink 30 and bringing the seal material 13 of the second case portion 12 into close contact with the heat reception surface 30a of the heat sink 30. ing.

  For example, the power conversion device 1 configured as described above is installed in a state where the ventilation unit 20 is exposed to the outside. Since the housing case 10 that houses the main circuit board 2A and the sub circuit board 2B and the ventilation part 20 exposed to the outside are isolated by the second case part 12, water such as rainwater can enter the ventilation path 21. Even if it enters, there is no possibility of affecting the control circuit and electronic components mounted on the main circuit board 2A and the sub circuit board 2B.

  When the ventilation fan 50 is driven in the above-described installation state, external air is introduced into the ventilation passage 21 through the ventilation holes 12g of the ventilation plate portion 12f. The air introduced into the ventilation passage 21 is exhausted to the outside of the ventilation passage 21 through the opening at the lower end after sequentially exchanging heat with the capacitor housing portion 12 b and the heat sink 30. Therefore, when the power converter 1 is operating, the heat generated in the capacitor 4 and the semiconductor module 3 is dissipated through the capacitor housing portion 12b and the heat sink 30 by the air passing through the ventilation passage 21. The influence of heat on the electronic components mounted on the main circuit board 2A and the sub circuit board 2B can be prevented. Moreover, in the power conversion device 1 described above, the capacitor housing portion 12 b is formed integrally with the main cover portion 12 a of the second case portion 12. Therefore, the number of components does not increase regardless of the number of capacitors 4 mounted on the circuit boards 2A and 2B. Further, it is not necessary to provide a seal member for ensuring water tightness between the main cover portion 12a and the capacitor housing portion 12b. Therefore, it is possible to improve the cooling performance of the capacitor 4 without causing the problem of increasing the number of parts and the problem of complicating the assembly work.

  In the above-described embodiment, since the condenser housing portion 12b is disposed in the ventilation passage 21, the cooling performance of the capacitor 4 can be further improved. However, the condenser housing portion 12b is not necessarily provided in the ventilation passage 21. It is not necessary to arrange.

  In the above-described embodiment, the individual capacitors 4 are arranged in the individual capacitor housing portions 12b. However, the present invention is not necessarily limited to this. For example, as in Modification 1 shown in FIGS. 8 and 9, an elliptical capacitor housing portion 112b is formed integrally with the second case portion 12, and a plurality (two in the illustrated example) are formed in the capacitor housing portion 112b. It is also possible to configure so as to accommodate the capacitor 4. In this case, it is preferable to configure the capacitor housing portion 112b so that the major axis of the ellipse is arranged along the ventilation direction of the ventilation portion 20 (arrow A in FIG. 8). That is, when the capacitor housing portion 112b is configured such that the major axis of the ellipse is arranged along the ventilation direction of the ventilation portion 20, the ventilation of the ventilation portion 20 is not hindered by the capacitor housing portion 112b. There is no possibility that the cooling performance of the semiconductor module 3 is impaired. In addition, in the modification 1 of FIG.8 and FIG.9, about the structure similar to embodiment, the same code | symbol is attached | subjected.

  Furthermore, in the above-described embodiment, the capacitor housing portion 12b is configured so as to be a bottomed cylindrical sealed container. For example, as in the second modification of FIGS. 10 and 11, the main cover portion 12a. If an opening (vent hole) 212c for ventilation is formed at the tip of the capacitor housing part 212b provided integrally with the heat, the heat released from the capacitor 4 to the inside of the capacitor housing part 212b is directly outside the second case part 12. The cooling performance can be further improved. However, the ventilation opening 212c needs to be covered with a moisture-permeable waterproof sheet 212d in order to prevent intrusion of water such as rainwater or dust. In addition, in the modification 2 of FIG.10 and FIG.11, the same code | symbol is attached | subjected about the structure similar to embodiment.

2B Circuit board 2Ba Mounting surface 4 Capacitor 10 Housing case 12a Main cover portion 12b Capacitor housing portion 20 Ventilation portion 21 Ventilation passage 40 Frame member 50 Ventilation fan 112b Capacitor housing portion 212b Capacitor housing portion 212c Opening 212d Moisture permeable waterproof sheet

Claims (3)

In the power conversion device in which the circuit board on which the semiconductor module and the capacitor are mounted is housed in the housing case,
The housing case is disposed so as to face the capacitor mounting surface of the circuit board, and forms a main cover part that covers the circuit board, and protrudes to the outside in a portion corresponding to the capacitor in the main cover part. A capacitor accommodating portion for accommodating the capacitor therein, a side surface projecting so as to cover an end surface of the circuit board from an end portion of the main cover portion, and a portion corresponding to the semiconductor module in the main cover portion And a communicating hole, and a case portion having
The capacitor housing is configured to be a sealed container that is open only at a portion facing the capacitor mounting surface of the circuit board,
The communication hole has a size capable of inserting the semiconductor module;
Around the communication hole, a seal groove for accommodating an endless seal material is provided on a surface that is not opposed to the circuit board,
The power conversion device, wherein the main cover portion, the side surface of the case portion, and the capacitor housing portion are integrally formed.   The ventilation fan which ventilates from one side of the ventilation path toward the other while arranging a ventilation path in the position which surrounds the capacitor accommodation part in the exterior of the storage case, and is arranged. Power converter. Forming the capacitor housing in an elliptical column shape;
The power conversion device according to claim 2, wherein a plurality of capacitors mounted on the circuit board in a manner along a ventilation direction of the ventilation passage are accommodated in the capacitor accommodation portion.

Images