JP6972949B2 - Power controller - Google Patents

Description

The technology disclosed herein relates to a power control device that controls the power supplied to a traveling motor.

The electric vehicle is equipped with a power control device that controls the power supplied to the traveling motor. The power control device is equipped with a cooler using a liquid refrigerant in order to handle a large amount of electric power. Patent Document 1-3 discloses a power control device in which a cooler using a liquid refrigerant is provided in a housing. In addition, water droplets may adhere to the power control device mounted on the vehicle, and the housing thereof is required to have water resistance.

Patent Document 1 discloses a power control device in which a refrigerant flow path is provided in the lower part of the housing. A gasket is arranged on the lower surface of the housing so as to surround the periphery of the refrigerant flow path, and a cover is attached to the lower surface with the gasket sandwiched so as to block the refrigerant flow path. On the other hand, a flow path port communicating with the refrigerant flow path is provided on the side surface of the housing.

Japanese Unexamined Patent Publication No. 2016-11125 Japanese Unexamined Patent Publication No. 2016-076511 Japanese Unexamined Patent Publication No. 2015-216295

A pipe (refrigerant pipe) for passing the refrigerant is connected to the flow path port provided on the side surface of the housing. Refrigerant may leak from the joint between the flow path port on the side surface of the housing and the refrigerant pipe. The leaked refrigerant may travel from the side surface to the lower surface of the housing and adhere to the gasket. Moisture adhering to the gasket can accelerate corrosion (deterioration) of the gasket and its surroundings. The present specification provides a technique for preventing water from adhering to a gasket in a power control device in which a cover blocking the refrigerant flow path is attached to the lower surface of the housing with the gasket interposed therebetween.

The power control device disclosed in the present specification includes a refrigerant flow path provided in a lower portion (lower surface) of the housing thereof and a cover that closes the refrigerant flow path. The cover is attached to the lower surface of the housing with a gasket arranged so as to surround the refrigerant flow path. A flow path port communicating with the refrigerant flow path is provided on the side surface of the housing. The housing is provided with a wall that protrudes from the lower surface along the edge below the flow path opening and close to the flow path opening of the cover. The liquid refrigerant leaking from the joint between the flow path port and the pipe is transmitted downward along the side surface of the housing. The liquid refrigerant may be transmitted from the side surface to the lower surface of the housing. However, the housing is provided with a wall that is below the channel opening and projects from the lower surface along the edge near the channel opening of the cover. The liquid refrigerant leaking from the joint between the flow path port and the pipe is blocked by the wall and cannot reach the gasket. Therefore, water is prevented from adhering to the gasket.

Details and further improvements to the techniques disclosed herein will be described in the "Modes for Carrying Out the Invention" section below.

It is a perspective view of the power control device of an Example. It is a perspective view which looked at the power control device of an Example from diagonally below. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. It is sectional drawing of the comparative example (power control device which does not have a protective wall).

The power control device 10 of the embodiment will be described with reference to the drawings. FIG. 1 shows a perspective view of the power control device 10. FIG. 2 shows a perspective view of the power control device 10 as viewed from diagonally below. FIG. 2 is a diagram in which the lower cover 16 is removed.

The electric power control device 10 of the embodiment is a device mounted on an electric vehicle and controlling the driving power of a traveling motor. The XYZ coordinate system in the figure is a coordinate system fixed to the power control device 10. The power control device 10 is used in a posture in which the + Z direction is upward. Note that in FIG. 2, the downward direction in the figure is the + Z direction.

Four flow path ports 18a, 18b, 19a, and 19b are provided on the front surface 112 of the housing 11 of the power control device 10. The housing 11 contains two refrigerant flow paths, the flow path ports 18a and 18b communicate with the upper refrigerant flow path, and the flow path ports 19a and 19b communicate with the lower refrigerant flow path. doing. The flow path port 18b and 19a are connected by a connecting pipe 21. The flow path ports 18a and 19b are connected to a refrigerant circulation device (not shown) outside the housing 11. The refrigerant supplied from the refrigerant circulation device is guided to the upper refrigerant flow path through the flow path port 18a. After passing through the upper refrigerant flow path, the refrigerant flows to the lower refrigerant flow path through the flow path port 18b, the connecting pipe 21, and the flow path port 19a. The refrigerant that has flowed through the lower refrigerant flow path is discharged from the flow path port 19b and returns to the refrigerant circulation device. The refrigerant is a liquid, water, or LLC (Long Life Coolant).

The housing 11 of the power control device 10 is provided with a flow path (refrigerant flow path 12) through which the refrigerant flows (see FIG. 2). The refrigerant flow path 12 corresponds to the above-mentioned lower refrigerant flow path. The refrigerant flow path 12 is provided on the lower surface 115 on the outer side of the housing 11. The refrigerant flow path 12 is divided into a supply path 121 and a discharge path 122 in the lateral direction (Y direction) by the partition plate 13. The supply path 121 communicates with the flow path port 19a provided on the front surface 112 of the housing 11, and the discharge path 122 communicates with the flow path port 19b provided on the front surface 112. The partition plate 13 extends from the front to the rear and ends in the middle. The supply path 121 and the discharge path 122 are connected by a U-turn portion 123 at the rear of the refrigerant flow path 12. As described above, the liquid refrigerant is supplied to the refrigerant flow path 12 from the flow path port 19a. The refrigerant supplied through the flow path port 19a passes through the supply path 121, the U-turn portion 123, and the discharge path 122, and is discharged from the flow path port 19b. An electric portion having a large calorific value is arranged inside the housing 11 so as to face the refrigerant flow path 12. The heat of the electric component is absorbed by the refrigerant passing through the refrigerant flow path 12.

The lower side (bottom of the refrigerant flow path 12) of the refrigerant flow path 12 provided in the lower part (lower surface 115) of the housing 11 is open. A gasket 14 is arranged on the lower surface 115 of the housing 11 so as to surround the refrigerant flow path 12. The open bottom surface of the refrigerant flow path 12 is covered with the lower cover 16. The lower cover 16 is attached to the lower surface 115 of the housing 11 with the gasket 14 interposed therebetween. The lower cover 16 is attached to the lower surface 115 with a plurality of bolts 28. A plurality of bolt holes 29 screwed with the bolt 28 are provided on the lower surface 115 of the housing 11 so as to surround the refrigerant flow path 12 and the gasket 14. In FIG. 2, a reference numeral 28 is attached to only one of the plurality of bolts 28, and the reference numeral is omitted for the remaining bolts. Similarly, of the plurality of bolt holes 29, only one bolt hole is designated by the reference numeral 29, and the remaining bolt holes are designated by the reference numerals.

The gasket 14 may be a metal gasket or a rubber gasket. Alternatively, the gasket 14 may be a FIPG (Formed In Place Gasket). In the case of the embodiment, the gasket 14 is FIPG. FIPG is initially gel-like and solidifies when exposed to air.

A protective wall 17 is provided on the lower surface 115 of the housing 11 at the boundary with the front surface 112. The protective wall 17 is provided between the flow path openings 19a and 19b and the lower cover 16 (gasket 14). The protective wall 17 extends along the edges of the lower cover 16 near the flow path openings 19a, 19b. In other words, the protective wall 17 is provided below the flow path openings 19a and 19b along the edge of the lower cover 16 (the edge of the gasket 14).

FIG. 3 shows a cross-sectional view taken along the line III-III of FIG. The cross-sectional view of FIG. 3 is a cross-sectional view which is a plane parallel to the XZ plane of the coordinate system in the figure and is cut by a plane passing through the flow path port 19a and the connecting pipe 21. In FIG. 3, the upper part of the housing 11 is not shown. As described above, the electric component 90 is arranged inside the housing 11 so as to face the refrigerant flow path 12. The electrical component 90 is, for example, a reactor or a capacitor. Further, as described above, the lower surface 115 of the housing 11 is provided with a protective wall 17 below the flow path openings 19a and 19b and along the edge of the lower cover 16 near the flow path openings 19a and 19b. There is.

The function of the protective wall 17 will be described. An enlarged view of the range surrounded by the broken line A in FIG. 3 is shown at the lower side of FIG. The flow path openings 19a and 19b are located above the protective wall 17. A connecting pipe 21 is connected to the flow path port 19a. A pipe extending from a refrigerant circulation device (not shown) is connected to the flow path port 19b. Liquid refrigerant may leak from the joint between the flow path ports 19a and 19b and the pipe (connecting pipe 21 or the like). The refrigerant leaking from the seam moves downward along the front surface 112 of the housing 11. The protective wall 17 is located between the flow path ports 19a and 19b and the gasket 14, and prevents water droplets that have moved from the front surface 112 to the bottom surface 115 of the housing 11 to adhere to the gasket 14. The water adhering to the gasket 14 causes the corrosion (deterioration) of the gasket 14 and its surroundings to be accelerated. The protective wall 17 prevents moisture from adhering to the gasket 14, and suppresses deterioration of the gasket 14 and its surroundings.

The protective wall 17 also has the following advantages. In the power control device 10 of the embodiment, the leading edge of the gasket 14 is close to the front surface 112 of the housing 11. The gasket 14 is a FIPG that is initially in the form of a gel. FIG. 4 shows a cross-sectional view of a comparative example (power control device 910 without a protective wall). In the power control device 910, the distance between the flow path port 19a and the gasket 14 is short, and the gasket is FIPG (Formed In Place Gasket). When the FIPG before solidification is applied to the lower surface 115 of the housing and the lower cover 916 is attached, the gel-like FIPG 914 extruded from between the lower cover 916 and the lower surface 115 may adhere to the flow path port 19a. Point P2 in FIG. 4 shows FIPG914 reaching the inside of the flow path port 19a. On the other hand, in the power control device 10 of the embodiment, since the protective wall 17 is provided along the leading edge of the gasket 14, the FIPG extruded from between the lower surface 115 and the lower cover 6 is blocked by the protective wall 17. It does not reach the flow path port 19a. Point P1 in FIG. 3 shows the FIPG blocked by the protective wall 17.

As described above, a protective wall 17 extending along the gasket 14 is provided between the flow path ports 19a and 19b provided on the front surface 112 of the housing 11 and the gasket 14 arranged on the lower surface 115 of the housing 11. Therefore, it is possible to prevent the adhesion of water to the gasket 14.

The points to be noted regarding the technique described in the examples will be described. The flow path ports 19a and 19b of the embodiment correspond to an example of a flow path port communicating with the refrigerant flow path. The flow path port may be provided on the side surface or the rear surface instead of the front surface of the housing. The protective wall 17 corresponds to an example of a wall protruding from the housing between the flow path port and the gasket.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples exemplified above. The technical elements described herein or in the drawings exhibit their technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques exemplified in the present specification or the drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

6: Lower cover 10: Power control device 11: Housing 12: Refrigerant flow path 13: Partition plate 14: Gasket 16: Lower cover 17: Protective walls 18a, 18b, 19a, 19b: Flow path port 21: Connecting pipe 28: Bolt 29: Bolt hole 90: Electrical component 112: Front surface 115: Bottom surface 121: Supply path 122: Discharge path 123: U-turn portion 910: Power control device 916: Lower cover

Claims (1)

The refrigerant flow path provided at the bottom of the housing of the power control device,
A cover attached to the lower surface of the housing with a gasket arranged so as to surround the refrigerant flow path, and a cover that closes the refrigerant flow path.
A flow path port provided on the side surface of the housing and communicating with the refrigerant flow path, and a flow path port.
A wall below the flow path port that protrudes from the lower surface along the edge of the cover near the flow path port.
It is equipped with a power control device.

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