JP2021097474A - Electric power conversion system - Google Patents

Abstract

To provide an electric power conversion system capable of achieving treatment of dew condensation water in an enclosure, reduction in the number of components and prevention of invasion into the enclosure.SOLUTION: An electric power conversion system 1 includes: an enclosure 2; a base part 3 stored in the enclosure 2; a circuit board 4 stored in the enclosure 2 and supported on the downward side of the base part 3; an electric power conversion module 5 stored in the enclosure 2 and arranged on the upward side of the base part 3; and a cooling part 6 mounted on the enclosure 2 and cooling the electric power conversion module 5 on the upward side of the base part 3. The base part 3 has a water receiving region 31 provided downward of the cooling part 6, a cut-off wall 32 provided around the water receiving region 31 and a drain channel 33 joined to the water receiving region 31. The drain channel 33 includes an inlet 33a opened to the cut-off wall 32 and facing the water receiving region 31 and an outlet 33b formed more outward than an outer edge 41 of the circuit board 4.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a power converter.

Conventionally, an invention relating to an inverter device including a water receiving member for guiding condensed water dripping from a cooling unit has been known (see Patent Document 1 below). An object of the invention described in Patent Document 1 is to provide an inverter device capable of guiding condensed water while suppressing the complexity of the process of forming a water receiving member and the increase in the number of parts (the same). See literature, abstracts, paragraph 0006, etc.).

As a means for solving this problem, the conventional inverter device is arranged below the cooling unit for cooling the electronic components and the cooling unit, and downward so as to guide the condensed water dripping from the cooling unit. It is provided with a sheet metal water receiving member arranged at an angle (see the same document, abstract, claim 1, paragraph 0007, etc.). On both sides of the guide portion of the water receiving member, water channel portions for guiding the condensed water to the discharge member are fixed by screws (see the same document, paragraph 0039, etc.).

Further, in the conventional inverter device, a sheet metal discharge member is arranged below the water receiving member so as to be separated from the water receiving member, and the condensed water dripping from the water receiving member is discharged to the outside of the inverter device main body. Further provided (see the same document, claim 7, paragraph 0040, etc.). The inclined portion of the discharge member is inserted into the discharge hole provided on the front surface of the housing, and the condensed water passes through the guide portion and the relief portion of the water receiving member, the water passage portion, and the inclined portion of the discharge member. , Accumulates in the box-shaped part of the discharge member (see the same document, paragraph 0043, etc.).

JP-A-2017-158248

The conventional inverter device not only requires a water receiving member, a fastening member, a water channel portion, and a draining member as dedicated parts for discharging condensed water, but also forms a draining hole on the front surface of the housing. Therefore, the problems are the increase in the number of parts and the intrusion of foreign matter into the housing.

The present disclosure provides a power conversion device that enables treatment of condensed water inside a housing, reduction of the number of parts, and prevention of foreign matter from entering the housing.

One aspect of the present disclosure is a housing, a base portion housed in the housing, a circuit board housed in the housing and supported on the lower side of the base portion, and housed in the housing. A power conversion module arranged on the upper side of the base portion and a cooling unit provided in the housing for cooling the power conversion module on the upper side of the base portion are provided, and the base portion is provided with the cooling portion. It has a water receiving area provided below the portion, a water blocking wall provided around the water receiving area, and a drainage channel connected to the water receiving area, and the drainage channel has the stop. A power conversion device including an inlet that opens into a water wall and faces the water receiving region, and an outlet that is provided outside the outer edge of the circuit board.

According to the above aspect of the present disclosure, it is possible to provide a power conversion device capable of treating dew condensation water inside the housing, reducing the number of parts, and preventing foreign matter from entering the inside of the housing. ..

The front view which shows one Embodiment of the power conversion apparatus of this disclosure. An exploded perspective view of the power conversion device shown in FIG. FIG. 2 is a perspective view of the base portion shown in FIG. FIG. 3 is a cross-sectional view of the power conversion device shown in FIG. FIG. 3 is a perspective view of a state in which the power conversion device shown in FIG. 1 is disconnected. FIG. 3 is a cross-sectional view of the base portion along the VI-VI line shown in FIG. An enlarged view of a through hole and a drainage channel of the base portion shown in FIG. An enlarged view of the headrace portion included in the drainage channel of the base portion shown in FIG. An enlarged view of the headrace portion included in the drainage channel of the base portion shown in FIG.

Hereinafter, embodiments of the power conversion module of the present disclosure will be described with reference to the drawings.

FIG. 1 is a front view showing an embodiment of the power conversion device of the present disclosure. FIG. 2 is an exploded perspective view of the power conversion device 1 shown in FIG. FIG. 3 is a perspective view of the base portion 3 shown in FIG. FIG. 4 is a cross-sectional view of the power conversion device shown in FIG. FIG. 5 is a perspective view of the power conversion device shown in FIG. 1 in a disconnected state.

As shown in FIG. 1, the power conversion device 1 of the present embodiment is, for example, a device attached to a housing M1 of an in-vehicle motor M to supply electric power to the motor M. Note that FIG. 1 shows a state in which a part of the housing M1 of the motor M is cut off. The motor M is mounted on a vehicle such as an electric vehicle (EV), a hybrid vehicle (HV), a plug-in hybrid vehicle (PHV), or a fuel cell vehicle (FCV), and constitutes a vehicle drive device. Since the configuration of the motor M is known, the description thereof will be omitted.

The power conversion device 1 is connected to, for example, a terminal of the motor M, converts a direct current supplied from an in-vehicle power source such as a lithium ion secondary battery or a fuel cell into an alternating current and supplies the direct current to the motor M to supply the motor M. Drive. Although details will be described later, the power conversion device 1 of the present embodiment is characterized by the following configuration.

The power conversion device 1 includes a housing 2, a base portion 3 housed in the housing 2, and a circuit board 4 housed in the housing 2 and supported on the lower side of the base portion 3. Further, the power conversion device 1 includes a power conversion module 5 housed in the housing 2 and arranged on the upper side of the base portion 3, and a power conversion module 5 provided on the housing 2 on the upper side of the base portion 3. A cooling unit 6 for cooling is provided. The base portion 3 includes a water receiving region 31 provided below the cooling portion 6, a water blocking wall 32 provided around the water receiving region 31, and a drainage channel 33 connected to the water receiving region 31. have. The drainage channel 33 includes an inlet 33a that opens into the water blocking wall 32 and faces the water receiving region 31, and an outlet 33b provided outside the outer edge 41 of the circuit board 4.

Hereinafter, the configuration of the power conversion device 1 of the present embodiment will be described in detail. The housing 2 has a storage space for accommodating the parts constituting the power conversion device 1 inside. The housing 2 has, for example, a bottom wall 21, a cover 22, and an upper lid 23 made of a conductive material such as metal.

The bottom wall 21 is a flat plate-shaped member that is arranged below the circuit board 4 and defines the lower end of the accommodation space inside the housing 2. The bottom wall 21 is fixed to the housing M1 of the motor M by, for example, a fastening member such as a bolt. The bottom wall 21 may be provided integrally with the housing M1 as a part of the housing M1 of the motor M, for example. The bottom wall 21 has a partition wall 21b that defines a plurality of water retention regions 21a on the upper surface facing the circuit board 4.

The bottom wall 21 has, for example, a concave or dish-shaped shape, and has a peripheral wall portion rising from the upper surface at a predetermined height at the peripheral edge portion. The upper end of the peripheral wall portion of the bottom wall 21 is provided, for example, in the shape of a flange protruding outward. The bottom wall 21 has, for example, a lattice-shaped partition wall 21b that projects upward from the upper surface at a predetermined height inside the peripheral wall portion. The upper surface of the bottom wall 21 is divided into a plurality of water retention regions 21a by the partition wall 21b.

The water retention region 21a is, for example, a flat region in which the upper surface inside the peripheral wall portion of the bottom wall 21 is partitioned by a grid-like partition wall 21b. Each water retention region 21a is defined by a partition wall 21b surrounding it. That is, the partition wall 21b prevents the water in each water retention area 21a from moving to the outside of the water retention area 21a, and keeps the water in each water retention area 21a in the water retention area 21a. be able to. Further, the bottom wall 21 has, for example, a through hole 21c for passing a bus bar or electrical wiring (not shown) connecting the power conversion module 5 and the terminal of the motor M.

The cover 22 extends from, for example, a flat upper wall portion defining the upper end of the accommodation space inside the housing 2 and the peripheral edge of the upper wall portion toward the peripheral edge portion of the bottom wall 21 to accommodate the housing 2. It has a side wall that defines the side edges of the space. The upper lid 23 is a plate-shaped member that closes the upper part of the cooling portion 6 provided in the housing 2. The lower end surface of the side wall portion of the cover 22 is in contact with the upper end surface of the peripheral wall portion of the bottom wall 21, and the upper lid 23 is placed on the upper end surface of the cover 22. In this state, the peripheral wall portion of the bottom wall 21 and the side wall portion of the cover 22 and the peripheral edge portion of the upper lid 23 and the upper end surface of the cover 22 are fastened with fastening members such as bolts and nuts. As a result, the housing 2 having the accommodation space inside can be assembled.

Further, the housing 2 has, for example, a fixed portion 24 fixed to an external device such as the motor M shown in FIG. 1, and a heat conduction path 25 for causing heat conduction from the fixed portion 24 to the bottom wall 21. doing. In the example shown in FIG. 4, the fixing portion 24 is a flange-shaped portion provided on the cover 22 and has a bolt hole for passing a bolt. Further, the heat conduction path 25 is composed of a fixed portion 24 and a part of the cover 22.

Further, as shown in FIG. 4, the housing 2 has a convex portion 26 extending downward from the cooling portion 6 toward the water receiving region 31 of the base portion 3. More specifically, the convex portion 26 extends downward from the partition wall 62 defining the coolant flow path 61 constituting the cooling portion 6 toward the water receiving region 31 of the base portion 3. The tip of the convex portion 26 is in contact with the upper surface of the base portion 3 in the water receiving region 31, for example, and is fixed to the base portion 3 by a fastening member such as a bolt. As a result, the tip of the convex portion 26 is connected to, for example, the water receiving region 31 of the base portion 3.

The base portion 3 is a member for holding and fixing the circuit board 4 inside the housing 2. More specifically, the base portion 3 is arranged on the upper side opposite to the bottom wall 21 of the housing 2 with respect to the circuit board 4, and generally covers the entire surface of the circuit board 4 on which the electronic components are mounted. It is a plate-shaped member that covers it. The base portion 3 is formed of a material capable of shielding electromagnetic waves, such as a metal plate or a resin plate having a metal layer on the surface, and is attached to the housing 2 by a fastening member such as a bolt.

The base portion 3 has a water receiving region 31 provided below the cooling portion 6, a water blocking wall 32 provided around the water receiving region 31, and a drainage channel 33 connected to the water receiving region 31. Have. Further, the base portion 3 connects, for example, a plurality of through holes 34 for passing the terminals 51 of the power conversion module 5 connected to the circuit board 4, and the terminals of the power conversion module 5 and an external device such as the motor M. It has a through hole 35 for passing a bus bar or an electric wiring to be used.

The water receiving region 31 is a flat region on the upper surface of the base portion 3 for receiving the condensed water dripping from the cooling portion 6. In the water receiving region 31, the upper surface of the base portion 3 may have an inclination that gradually decreases toward the inlet 33a of the drainage channel 33, for example. In other words, in the water receiving region 31, the upper surface of the base portion 3 may have an inclination that increases as the distance from the inlet 33a of the drainage channel 33 increases, for example.

The water stop wall 32 has a predetermined height from the upper surface of the base portion 3 and surrounds the water receiving region 31. The inlet 33a of the drainage channel 33 is formed by opening a part of the water blocking wall 32 surrounding the water receiving region 31. The water stop wall 32 prevents the movement of water from the water receiving area 31 to the outside of the water receiving area 31 except for the movement of water from the water receiving area 31 to the drainage channel 33. Further, the water blocking wall 32 is provided, for example, between the through hole 34 for passing the terminal 51 of the power conversion module 5 and the water receiving region 31.

The drainage channel 33 is connected to the water receiving area 31, and discharges the condensed water dropped from the cooling unit 6 to the water receiving area 31 to the outside of the outer edge 41 of the circuit board 4. The drainage channel 33 includes an inlet 33a that opens into the water blocking wall 32 and faces the water receiving region 31, and an outlet 33b provided outside the outer edge 41 of the circuit board 4.

The through hole 35 of the base portion 3 is provided, for example, in the shape of an elongated hole extending along the outer edge 41 of the circuit board 4. The base portion 3 has, for example, a tubular hanging portion 36 extending downward from the opening of the through hole 35. The base portion 3 has, for example, a protruding support portion 37 for supporting the circuit board 4 on one surface of the housing 2 facing the bottom wall 21.

Further, the base portion 3 is supported by fixing a power conversion module 5, a filter, a capacitor, a sensor, etc. (not shown) on a surface opposite to one surface on which the circuit board 4 is supported. .. Although not shown, the bus bar or electrical wiring connected to the power conversion module 5 passes through the through hole 35 of the base portion 3 and the through hole 21c provided in the bottom wall 21 of the housing 2 to form a housing. It extends to the outside of body 2.

In the example shown in FIGS. 2 to 5, the drainage channel 33 is provided between the plurality of through holes 34 for passing the terminals 51 of the power conversion module 5, and the through holes 35 for passing the bus bar or the electric wiring. It is provided in the vicinity.

FIG. 6 is a cross-sectional view of the base portion 3 along the VI-VI line shown in FIG. FIG. 7 is an enlarged view of the through hole 34 and the drainage channel 33 of the base portion 3 shown in FIG. 8 and 9 are enlarged views of the water conveyance portion 33c included in the drainage channel 33 of the base portion 3 shown in FIG.

As shown in FIGS. 3 and 6, the drainage channel 33 provided between the plurality of through holes 34 for passing the terminals 51 of the power conversion module 5 is provided with respect to the inlet 33a provided between the through holes 34. Includes an inclined surface 33d that is lowered in a stepped manner and gradually lowered toward the outlet 33b. The inclined surface 33d is made lower than, for example, the opening 34a on the upper side of the through hole 34. The inclined surface 33d extends from the central portion of the base portion 3 toward the outer edge of the base portion 3 located outside the outer edge 41 of the circuit board 4, for example, in a direction intersecting the outer edge 41 of the circuit board 4. .. The inclined surface 33d is inclined so as to become lower as it approaches the outer edge of the base portion 3, for example.

As shown in FIGS. 4, 7 and 8, the drainage channel 33 provided between the plurality of through holes 34 for passing the terminals 51 of the power conversion module 5 is, for example, above the upper surface of the circuit board 4. Includes a water guide 33c that connects the inlet 33a located at and the outlet 33b located below the upper surface of the circuit board 4. The water conveyance portion 33c is gradually lowered from the inlet 33a of the drainage channel 33 toward the outlet 33b.

As shown in FIGS. 4 and 9, the drainage channel 33 provided in the vicinity of the bus bar or the through hole 35 for passing the electric wiring is, for example, an inlet 33a located above the upper surface of the circuit board 4 and the circuit board. A water guide portion 33c that connects the outlet 33b located below the upper surface of the fourth portion 4 is included. The water guiding portion 33c is, for example, a part of a tubular hanging portion 36 extending downward from the opening of the through hole 35. The water conveyance portion 33c is gradually lowered from the inlet 33a of the drainage channel 33 toward the outlet 33b.

The circuit board 4 is equipped with, for example, a power conversion module 5, an IC, a transistor, a resistor, and the like, and includes an electronic circuit for controlling the power conversion module 5. The power conversion module 5 incorporates a power semiconductor element and a switching element, and is controlled by a circuit board 4 to perform mutual conversion between direct current and alternating current. For example, a filter, a capacitor, a sensor, and the like (not shown) are connected to the power conversion module 5. The sensor detects, for example, the magnitude of the current flowing from the power conversion module 5 to the bus bar or the electric wiring, and transmits the electric signal of the detection result to the electronic circuit of the circuit board 4.

Hereinafter, the operation of the power conversion device 1 of the present embodiment will be described.

As described above, the power conversion device 1 includes a housing 2, a base portion 3 housed in the housing 2, and a circuit board 4 housed in the housing 2 and supported on the lower side of the base portion 3. , Equipped with. Further, the power conversion device 1 includes a power conversion module 5 housed in the housing 2 and arranged on the upper side of the base portion 3, and a power conversion module 5 provided on the housing 2 on the upper side of the base portion 3. A cooling unit 6 for cooling is provided. The base portion 3 includes a water receiving region 31 provided below the cooling portion 6, a water blocking wall 32 provided around the water receiving region 31, and a drainage channel 33 connected to the water receiving region 31. have. The drainage channel 33 includes an inlet 33a that opens into the water blocking wall 32 and faces the water receiving region 31, and an outlet 33b provided outside the outer edge 41 of the circuit board 4.

With such a configuration, the power conversion device 1 can, for example, convert the direct current supplied from the vehicle-mounted power supply into an alternating current by the power conversion module 5 and supply it to the motor M to drive the motor M. At this time, since the power conversion module 5 generates heat, for example, a refrigerant such as cooling water is passed through the cooling unit 6 to cool the power conversion module 5 and its surroundings. When the surface of the cooling unit 6 is cooled inside the housing 2 and becomes colder than the other parts, water vapor contained in the air inside the housing 2 may condense on the surface of the cooling unit 6. .. When the amount of dew condensation water adhering to the surface of the cooling unit 6 increases due to dew condensation, the dew condensation water will eventually drip downward from the surface of the cooling unit 6.

The condensed water dripping downward from the surface of the cooling unit 6 is received by the water receiving region 31 provided below the cooling unit 6. When the amount of dew condensation water dripping on the water receiving area 31 increases to some extent, the dew condensation water dripping on the water receiving area 31 collects and tends to flow to the lower side. Most of the flow of water from the water receiving area 31 to the outside of the water receiving area 31 is blocked by the water blocking wall 32 provided around the water receiving area 31, and the water collects in the water receiving area 31.

The water collected in the water receiving area 31 eventually opens into the water blocking wall 32 and flows into the drainage channel 33 through the inlet 33a of the drainage channel 33 facing the water receiving area 31. The water that has flowed into the inlet 33a of the drainage channel 33 flows through the drainage channel 33 and is discharged from the outlet 33b provided outside the outer edge 41 of the circuit board 4. The water discharged from the outlet 33b of the drainage channel 33 flows or falls below the circuit board 4 outside the outer edge 41 of the circuit board 4. Therefore, the contact between the dew condensation water generated inside the housing 2 and the circuit board 4 can be avoided, and the influence of the dew condensation water on the circuit board 4 can be avoided. As described above, according to the power conversion device 1 of the present embodiment, the housing 2 is provided with the base portion 3 required to support the circuit board 4 and shield the electromagnetic waves from the power conversion module 5 to the circuit board 4. Condensation water inside can be treated.

Therefore, the power conversion device 1 of the present embodiment does not require a dedicated component used only for discharging the condensed water. Further, the power conversion device 1 of the present embodiment is an opening for discharging the dew condensation water by discharging the dew condensation water to the outside of the outer edge 41 of the circuit board 4 by the drainage channel 33 of the base portion 3 and guiding the dew condensation water downward. It is not necessary to provide the housing 2. Therefore, according to the present embodiment, there is provided a power conversion device 1 that enables treatment of dew condensation water inside the housing 2, reduction of the number of parts, and prevention of foreign matter from entering the inside of the housing 2. can do.

Further, in the power conversion device 1 of the present embodiment, the drainage channel 33 of the base portion 3 has an inlet 33a located above the upper surface of the circuit board 4 and an outlet 33b located below the upper surface of the circuit board 4. Includes a water guide 33c to be connected.

With this configuration, the water flowing from the water receiving region 31 into the inlet 33a of the drainage channel 33 flows downward along the water conveyance portion 33c, is located below the upper surface of the circuit board 4, and is located below the outer edge 41 of the circuit board 4. Is also guided to the outlet 33b located on the outside. As a result, the water flowing through the water guiding portion 33c of the drainage channel 33 can be discharged from the outlet 33b which is lower than the upper surface of the circuit board 4 and outside the outer edge 41 of the circuit board 4.

Therefore, for example, even if the power conversion device 1 mounted on the vehicle vibrates or tilts, the influence of the dew condensation water generated inside the housing 2 is more reliably avoided on the circuit board 4. be able to. Further, as shown in FIG. 8, the water guide portion 33c is extended to the vicinity of the cover 22 of the housing 2, and the outlet 33b of the drainage channel 33 is adjacent to the side wall of the cover 22, so that the water can be discharged from the outlet 33b of the drainage channel 33. The water can be made to flow downward along the inner surface of the cover 22.

Further, in the power conversion device 1 of the present embodiment, the water conveyance portion 33c included in the drainage channel 33 of the base portion 3 is gradually lowered from the inlet 33a of the drainage channel 33 toward the outlet 33b.

With this configuration, the water that has flowed into the inlet 33a of the drainage channel 33 flows down along the water guide 33c toward the outlet 33b without staying in the middle of the water guide 33c. Therefore, the drainage capacity of the drainage channel 33 can be improved, and the water accumulated in the water receiving region 31 of the base portion 3 arranged above the circuit board 4 can be promptly moved below the circuit board 4 by the drainage channel 33. It can be discharged to the outside.

Further, in the power conversion device 1 of the present embodiment, the housing 2 has a convex portion 26 extending downward from the cooling portion 6 toward the water receiving region 31 of the base portion 3.

With this configuration, the condensed water condensed on the surface of the cooling portion 6 inside the housing 2 flows downward along the surface of the convex portion 26 and is guided to the water receiving region 31 of the base portion 3. That is, the condensed water on the surface of the cooling unit 6 can be guided to the water receiving region 31 by the convex portion 26, and the condensed water can be prevented from falling from the cooling unit 6 to the outside of the water receiving region 31. ..

Further, in the power conversion device 1 of the present embodiment, the tip of the convex portion 26 of the housing 2 is connected to the water receiving region 31 of the base portion 3.

With this configuration, the condensed water condensed on the surface of the cooling portion 6 inside the housing 2 flows downward along the surface of the convex portion 26, and at the tip of the convex portion 26, from the surface of the convex portion 26 to the base portion 3. Move to the water receiving area 31. That is, the dew condensation water on the surface of the cooling unit 6 can be guided to the water receiving region 31 along the surface of the convex portion 26 without dropping in the space inside the housing 2, and the dew condensation water can be guided to the water receiving region 31. It is possible to more reliably prevent the water from falling to the outside of the water receiving area 31.

Further, in the power conversion device 1 of the present embodiment, the base portion 3 has a plurality of through holes 34 for passing the terminals 51 of the power conversion module 5 connected to the circuit board 4. The water blocking wall 32 of the base portion 3 is provided between these through holes 34 and the water receiving region 31.

With this configuration, the water accumulated in the water receiving area 31 is blocked by the water blocking wall 32 provided between the through hole 34 for passing the terminal 51 of the power conversion module 5 and the water receiving area 31, and the through hole. It is prevented from flowing into 34. As a result, it is possible to prevent the water accumulated in the water receiving region 31 from flowing down to the upper surface of the circuit board 4 through the through hole 34.

Further, in the power conversion device 1 of the present embodiment, the drainage channel 33 of the base portion 3 is lowered in a stepped manner with respect to the inlet 33a provided between the through holes 34, and is gradually lowered toward the outlet 33b. Includes surface 33d.

With this configuration, the water flowing in from the inlet 33a of the drainage channel 33 flows down to the inclined surface 33d lowered in a stepped manner with respect to the inlet 33a, and is prevented from flowing back to the water receiving region 31. Further, the water that has flowed down to the inclined surface 33d flows toward the outlet 33b along the inclined surface 33d that gradually decreases toward the outlet 33b. As a result, the drainage capacity of the drainage channel 33 can be improved, and the water accumulated in the water receiving region 31 can be quickly discharged to the outside of the outer edge 41 of the circuit board 4.

Further, in the power conversion device 1 of the present embodiment, the inclined surface 33d included in the drainage channel 33 of the base portion 3 is made lower than the opening 34a on the upper side of the through hole 34.

With this configuration, it is possible to more reliably prevent the water that has flowed down from the inlet 33a of the drainage channel 33 to the inclined surface 33d from entering the opening 34a on the upper side of the through hole 34 through which the terminal 51 of the power conversion module 5 passes. it can. Further, the drainage capacity of the inclined surface 33d of the drainage channel 33 is improved, and the water in the vicinity of the terminal 51 of the power conversion module 5 is easily discharged to the outside of the outer edge 41 of the circuit board 4 by the inclined surface 33d.

Further, in the power conversion device 1 of the present embodiment, the housing 2 has a bottom wall 21 below the circuit board 4. The bottom wall 21 has a partition wall 21b that defines a plurality of water retention regions 21a on the upper surface facing the circuit board 4.

With this configuration, the water discharged from the outlet 33b of the drainage channel 33 of the base portion 3 and moved below the circuit board 4 outside the outer edge 41 of the circuit board 4 is collected in the water retention region 21a on the upper surface of the bottom wall 21. The water collected in the water retention region 21a is suppressed from moving to the outside of the water retention region 21a by the partition wall 21b. Further, the water flowing out from a certain water retention area 21a beyond the partition wall 21b is collected in another water retention area 21a adjacent to the water retention area 21a, and is moved to the outside of the water retention area 21a by the partition wall 21b around the water retention area 21a. Movement is suppressed. Therefore, water is retained by the plurality of water retention regions 21a on the upper surface of the bottom wall 21, and it is possible to prevent water from flowing out from the upper surface of the bottom wall 21 to the outside due to, for example, vibration or inclination of the power conversion device 1.

Further, in the power conversion device 1 of the present embodiment, the housing 2 has a fixed portion 24 fixed to an external device such as a motor M, and a heat conduction path that causes heat conduction from the fixed portion 24 to the bottom wall 21. It has 25 and.

With this configuration, the heat generated by the external device such as the motor M is conducted to the bottom wall 21 via the fixed portion 24 of the housing 2 of the power conversion device 1 and the heat conduction path 25. As a result, evaporation of water held in the plurality of water retention regions 21a on the upper surface of the bottom wall 21 is promoted, and the water held in the water retention regions 21a becomes water vapor and is discharged from the inside of the housing 2 to the outside. Therefore, it is prevented that water stays in the water retention region 21a.

As described above, according to the present embodiment, power conversion that enables treatment of dew condensation water inside the housing 2, reduction of the number of parts, and prevention of foreign matter from entering the inside of the housing 2. Device 1 can be provided.

Although the embodiment of the power conversion device according to the present disclosure has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and the design change is not deviated from the gist of the present disclosure. Etc., but they are included in this disclosure.

1 Power conversion device 2 Housing 21 Bottom wall 21a Water retention area 21b Partition 24 Fixed part 25 Heat conduction path 26 Convex part 3 Base part 31 Water receiving area 32 Water stop wall 33 Drainage channel 33a Inlet 33b Outlet 33c Water conveyance part 33d Inclined surface 34 Through hole 34a Opening 35 Through hole 4 Circuit board 41 Outer edge 5 Power conversion module 51 Terminal 6 Cooling unit M Motor (external device)

Claims (10)

A housing, a base portion housed in the housing, a circuit board housed in the housing and supported on the lower side of the base portion, and a circuit board housed in the housing and supported on the upper side of the base portion. It is provided with an arranged power conversion module and a cooling unit provided in the housing and cooling the power conversion module on the upper side of the base portion.
The base portion has a water receiving region provided below the cooling portion, a water blocking wall provided around the water receiving region, and a drainage channel connected to the water receiving region.
The drainage channel is a power conversion device including an inlet that opens into the water blocking wall and faces the water receiving region, and an outlet provided outside the outer edge of the circuit board. The power conversion device according to claim 1, wherein the drainage channel includes a water conveyance portion that connects the inlet located above the upper surface of the circuit board and the outlet located below the upper surface. The power conversion device according to claim 2, wherein the water conveyance portion is gradually lowered from the inlet to the outlet. The power conversion device according to claim 1, wherein the housing has a convex portion extending downward from the cooling portion toward the water receiving region. The power conversion device according to claim 4, wherein the tip of the convex portion is connected to the water receiving region. The base portion has a plurality of through holes for passing terminals of the power conversion module connected to the circuit board.
The power conversion device according to claim 1, wherein the water stop wall is provided between the through hole and the water receiving region. The power conversion device according to claim 6, wherein the drainage channel includes an inclined surface that is stepped lower with respect to the inlet provided between the through holes and gradually lowers toward the outlet. The power conversion device according to claim 7, wherein the inclined surface is lower than the opening on the upper side of the through hole. The housing has a bottom wall below the circuit board.
The power conversion device according to claim 1, wherein the bottom wall has a partition wall that defines a plurality of water retention regions on an upper surface facing the circuit board. The power conversion device according to claim 9, wherein the housing has a fixed portion fixed to an external device and a heat conduction path that causes heat conduction from the fixed portion to the bottom wall.

Images