JP2020131869A - Power control device - Google Patents

Abstract

To provide a power control device in which pressure loss of a refrigerant when flowing in a refrigerant passage can be reduced.SOLUTION: A power control device comprises a housing which houses at least a part of electric equipment supplying power to a traction motor of an electric vehicle, and in which a refrigerant passage for circulating a refrigerant for cooling the electric equipment is formed. The housing is formed by combining a housing body and a cover. A joint portion is provided in the housing body, for making the refrigerant passage communicate with an external refrigerant pipe. A wall which is a part of the wall defining the refrigerant passage and is open on a cover side is engraved in the housing body. The refrigerant passage closed by the housing body side wall and the cover side wall is formed by combining the housing body and the cover. The cover side wall which is continuous with the joint portion is displaced to an opposite housing body side beyond a position where a surface intersecting the refrigerant passage of the housing body and the cover are tightly adhered to each other.SELECTED DRAWING: Figure 4

Description

The techniques disclosed herein relate to power control devices. In particular, a refrigerant passage that is mounted on an electric vehicle and circulates a refrigerant that accommodates at least a part of the electric equipment that supplies electric power to the traveling motor of the electric vehicle and cools the contained electric equipment is formed. The present invention relates to a power control device having a housing.

The "electric vehicle" as used herein includes a hybrid vehicle equipped with both a traction motor and an engine. Further, an automobile equipped with a fuel cell and a battery as a power source for a traveling motor is also included in the "electric vehicle".

There is known a power control device mounted on an electric vehicle in a state where an electric device such as an inverter that supplies electric power to a traveling motor of the electric vehicle and a converter that supplies boosted DC power to the inverter is housed in a housing. ing. Electric devices such as inverters and converters handle a large amount of electric power and therefore generate a large amount of heat. Patent Document 1 discloses a power control device in which a refrigerant passage for circulating a refrigerant for cooling such an electric device is formed in a housing.

In Patent Document 1, in order to cool the electrical equipment mounted on the upper side of the floor surface of the housing body (referred to as a case in Patent Document 1), the refrigerant is circulated under the floor surface of the housing body. There is. In addition, the housing body is typically manufactured by die-casting aluminum. Therefore, the entire hollow cross section of the refrigerant passage cannot be formed by the housing body. In Patent Document 1, another cover is attached to the lower side of the housing body to close the refrigerant passage, thereby forming the refrigerant passage. That is, the housing body forms a part of the wall of the refrigerant passage.

Further, in Patent Document 1, a slope that is displaced toward the lower side of the housing body toward the inside of the housing from the joint portion (referred to as the first opening in Patent Document 1) that takes in the refrigerant into the refrigerant passage provided in the housing. The floor surface of the housing body is formed so as to be. By forming a slope on the floor surface of the housing body in this way, a wide space inside the housing body is secured. In Patent Document 1, the space inside the housing body is widened and the size of the entire housing is reduced in order to reduce the size and weight of the vehicle.

Japanese Unexamined Patent Publication No. 2017-048990

In Patent Document 1, the surface of the cover that closes the refrigerant passage is a flat surface. Therefore, on the slope portion of the floor surface of the housing body, the upper end of the wall of the refrigerant passage formed by the housing body approaches the flat surface of the cover toward the inside of the housing body. That is, on the slope portion of the floor surface of the housing body, the cross-sectional area of the refrigerant passage changes and becomes narrower toward the inside of the housing body. If the cross section of the refrigerant passage changes rapidly, the pressure loss when the refrigerant flows through the refrigerant passage becomes large. In the present specification, when the refrigerant passage is formed by combining the housing body and the cover, the pressure loss when the refrigerant flows through the refrigerant passage can be reduced by gradually changing the cross-sectional area of the refrigerant passage. A power control device is presented.

The electric power control device disclosed in the present specification is mounted on an electric vehicle. Further, this electric power control device accommodates at least a part of the electric equipment that supplies electric power to the traveling motor of the electric vehicle, and has a casing in which a refrigerant passage for circulating the refrigerant that cools the contained electric equipment is formed. Have a body. The housing is formed by combining the housing body and the cover. The housing body includes a surface that intersects the refrigerant passage and a surface that extends along the refrigerant passage. A joint portion for communicating the refrigerant passage with the external refrigerant pipe is provided on the surface intersecting the refrigerant passage. The surface extending along the refrigerant passage is engraved with a wall that is a part of the wall defining the refrigerant passage and has an open cover side. Further, on the cover side, a wall that is a part of the wall that defines the refrigerant passage and the housing body side is open is engraved. In the power control device disclosed in the present specification, the refrigerant passage closed by the wall on the housing body side and the wall on the cover side is formed by combining the housing body and the cover. Further, the wall on the cover side following the joint portion is displaced toward the anti-housing body side from the position where the surface intersecting the refrigerant passage of the housing body and the cover are in close contact with each other.

By adopting the above-mentioned structure, the refrigerant flows through the wall carved on the housing body side and the refrigerant passage closed by the wall carved on the cover side. Since the wall on the cover side is displaced toward the anti-housing body side from the position where the cover is in close contact with the surface intersecting the refrigerant passage of the housing body, the upper end of the wall on the housing body side is displaced toward the cover side. However, the area of the refrigerant passage does not change suddenly. Therefore, in the power control device disclosed in the present specification, the pressure loss when the refrigerant flows through the refrigerant passage can be reduced.

Further, although the details will be described in Examples, the conventional cover is provided with ribs and the like for ensuring the rigidity of the cover. By suppressing the depth of the wall carved on the cover side from the height of the ribs, it is possible to reduce the pressure loss when the refrigerant flows through the refrigerant passage without increasing the thickness of the cover as a whole. That is, the pressure loss can be reduced without changing the size of the entire housing.

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 front compartment of the hybrid vehicle which carries the electric power control device of an Example. 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. It is sectional drawing along the IV-IV line of FIG. It is sectional drawing along the VV line of FIG.

A converter module, which is an example of the power control device of the embodiment, will be described with reference to the drawings. First, the device layout inside the front compartment 4 of the hybrid vehicle 2 on which the converter module 14 of the embodiment is mounted will be described with reference to FIG. In the coordinate system in the figure, the positive direction of the F axis indicates the front of the vehicle, and the positive direction of the V axis indicates the upper side of the vehicle. The positive direction of the H axis indicates the left side of the vehicle. In the present specification, the F-axis positive direction side may be expressed as the front side, the V-axis positive direction side as the upper side, and the H-axis positive direction side as the left side. It should be noted that FIG. 1 schematically shows a device mounted in the front compartment 4.

The front compartment 4 contains an engine 6, a transaxle 8, a power control unit 10, and a radiator 18. Various other devices are housed in the front compartment 4, but their illustration and description are omitted.

The power control unit 10 is fixed to the upper surface of the transaxle 8. The power control unit 10 is composed of a converter module 14 and an inverter module 12. The converter module 14 is a power control device that boosts the DC power of a main battery (not shown) by using an electric device such as a reactor contained therein. The inverter module 12 is a power control device that converts the DC power boosted by the converter module 14 into AC power suitable for driving the motor and supplies it to the traveling motor of the hybrid vehicle 2 housed in the transformer axle 8. The converter module 14 houses at least a part of electric devices that supply electric power to the traveling motor of the hybrid vehicle 2.

As shown in FIG. 1, the converter module 14 is arranged below the inverter module 12. The refrigerant passage formed in the converter module 14 and the refrigerant passage formed in the inverter module 12 are connected to each other by a resin water passage 16 provided on the front side of the power control unit 10. The refrigerant that circulates in the cooling passage formed in the inverter module 12 and cools the electrical equipment housed inside the inverter module 12 passes through the resin water channel 16 and the joint 22b (see FIG. 2) to the lower converter module. It flows into 14. The refrigerant that circulates in the cooling passage formed in the converter module 14 and cools the electrical equipment housed inside the converter module 14 flows out from the converter module 14 through the joint 22a (see FIG. 2). The refrigerant flowing out of the converter module 14 flows into a refrigerant pipe (not shown) arranged inside the front compartment 4. After that, the refrigerant is cooled by the radiator 18 and sent to the inverter module 12 again by a water pump (not shown). The electrical equipment housed in each of the inverter module 12 and the converter module 14 is cooled by the refrigerant circulating in this way.

Subsequently, the configuration of the converter case 14a, which is the housing of the converter module 14, will be described with reference to FIG. FIG. 2 is a perspective view of the converter case 14a. As shown in FIG. 2, the converter case 14a is formed by combining the case body 20 and the lower cover 26. The converter case 14a is a housing that houses an electric device such as a converter inside. The case body 20 is made of die-cast aluminum. The case body 20 is provided with a connecting surface 22 on the front side and a boundary surface 24 on the lower side. A joint 22a and a joint 22b are provided on the connection surface 22. As described above, the joint 22a is a refrigerant passage through which the refrigerant flows out from the converter module 14. The joint 22b is a refrigerant passage for allowing the refrigerant to flow into the converter module 14. Both the joints 22a and 22b are refrigerant passages for circulating the refrigerant that cools the electrical equipment housed in the converter module 14. That is, the connecting surface 22 intersects with the joints 22a and 22b, which are refrigerant passages. A lower cover 26 is attached to the boundary surface 24 of the case body 20. The lower cover 26 is also made of die-cast aluminum like the converter case.

Next, the detailed shape of the lower cover 26 will be described with reference to FIG. FIG. 3 is a perspective view of the converter case 14a as viewed from diagonally below. As described above, the lower cover 26 is attached to the boundary surface 24 of the case body 20. The lower cover 26 is fixed to the case body 20 by eight bolts 28 arranged at substantially equal intervals along the outer circumference. The lower cover 26 is provided with a rib 26b. The rib 26b goes around the outer circumference of the lower cover 26 while avoiding the bolt 28. The lower cover 26 secures shape rigidity by ribs 26b.

Further, as shown in FIG. 3, a U-shaped ridge with an open front side is provided on the lower surface (that is, the upper side of the drawing) of the lower cover 26. This ridge is the lower surface of the cover side passage 26w (see FIG. 4). Although details will be described later, the refrigerant flowing in from the joint 22b passes through the cover-side passage 26w and the refrigerant passage closed by the case-side passage 20w engraved on the case body 20 side, and flows out from the joint 22a. Therefore, the refrigerant passage formed in the converter case 14a has a U shape connecting the joint 22b and the joint 22a as shown in FIG. In the converter module 14 of the embodiment, the electric device housed inside is cooled by circulating the refrigerant in the U-shaped refrigerant passage.

The internal structure of the converter case 14a will be described with reference to FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. FIG. 4 shows a cross section passing through the center of the joint 22b, but the shape of the refrigerant passage described below is the same for the cross section passing through the center of the joint 22a. As shown in FIG. 4, the converter case 14a houses the reactor 30. The reactor 30 is one of the electric devices constituting the converter. Although the details are known, the reactor is an electric device having a coil and a core, and generates heat when energized. The reactor 30 is mounted on the upper side of the floor surface 20a of the converter case 14a. The floor surface 20a has a slope that is displaced upward as it goes forward from the front side of the reactor 30. A joint 22b is provided in front of the floor surface 20a. The resin water channel 16 is fixed to the joint 22b by two bolts 29. Although not shown, a packing on a thin plate is sandwiched in a portion where the joint 22b and the resin water channel 16 are in close contact with each other to seal the contact portion between the joint 22b and the resin water channel 16. On the lower side of the floor surface 20a, the terminals before and after the lower cover 26 are fixed to the case body 20 by bolts 28, respectively. The case body 20 and the lower cover 26 are in close contact with each other at the boundary surface 24. Grooves are provided on the front and rear boundary surfaces 24 of the space between the case body 20 and the lower cover 26. A rubber packing 25 sandwiched between the case body 20 and the lower cover 26 is provided in the groove of the boundary surface 24. The rubber packing 25 seals the space between the case body 20 and the lower cover 26. As described above, the refrigerant flows from the resin water channel 16 through the joint 22b into the space between the case body 20 and the lower cover 26. In other words, the space between the case body 20 and the lower cover 26 is a refrigerant passage through which the refrigerant circulates. That is, the joint 22b communicates the refrigerant passage with the external resin water channel 16.

In FIG. 4, the position of the boundary surface 24 in which the case body 20 and the lower cover 26 are in close contact with each other is indicated by a broken line for easy understanding. Since the surfaces of the case body 20 and the lower cover 26 in close contact with each other are flat, the broken line indicates the outer shape of the case body 20 and the lower cover 26. The lower surface of the floor surface 20a of the case body 20 is located above the broken line of the boundary surface 24 (that is, the case body 20 side). That is, the lower surface of the floor surface 20a of the case body 20 is carved from the boundary surface 24. The carved portion of the case body 20 forms a case-side passage 20w in which the lower cover 26 side is open. Similarly, the lower cover 26 is also engraved on the lower side (that is, the lower cover 26 side) of the boundary surface 24 below the broken line. The carved portion of the lower cover 26 forms a cover side passage 26w in which the case body 20 side is open.

Here, the refrigerant passage formed by the case body 20 and the lower cover 26 will be described once with reference to FIG. FIG. 5 is a partial cross-sectional view of the converter module 14 along VV of FIG. As shown in FIG. 5, a case-side passage 20w is engraved on the boundary surface 24 of the case body 20. The case-side passage 20w is a wall forming a cross section of the refrigerant passage. In other words, the case side passage 20w is a wall defining the refrigerant passage. The case-side passage 20w is open to the lower cover 26 side. Similarly, the cover side passage 26w is engraved on the lower cover 26. The cover side passage 26w is a wall forming a cross section of the refrigerant passage. In other words, the cover side passage 26w is a wall that defines the refrigerant passage. The cover side passage 26w is open to the case body 20 side.

As shown in FIG. 5, the refrigerant passage is formed by fixing the case body 20 and the lower cover 26 vertically. Further, similarly to FIG. 4, a rubber packing 25 sandwiched between the case main body 20 and the lower cover 26 is provided in the groove of the boundary surface 24. The rubber packing 25 seals the space formed by the case-side passage 20w and the cover-side passage 26w. By combining the case body 20 and the lower cover 26, the refrigerant passage is formed by being closed by the case side passage 20w and the cover side passage 26w. By closing in this way, the converter module 14 of the embodiment can circulate the refrigerant without leaking.

Here, returning to FIG. 4, the space for accommodating the electrical equipment in the converter case 14a will be described. As described above, the reactor 30 is mounted on the upper side of the floor surface 20a of the converter case 14a. Although not shown, the space above the floor surface 20a of the converter case 14a for accommodating electrical equipment also accommodates various electrical equipment other than the reactor 30. As described above, in the converter case 14a, the floor surface 20a is displaced upward toward the front side of the reactor 30 and is connected to the joint 22b. In other words, the floor surface 20a following the joint 22b is displaced toward the lower cover 26 toward the inside of the converter case 14a. By changing the floor surface 20a in this way, the space for accommodating the electrical equipment above the floor surface 20a can be widened. The converter module 14 of the embodiment accommodates various electric devices such as the reactor 30 without changing the size of the converter case 14a by widening the space for accommodating the electric devices on the floor surface 20a in this way. are doing.

As described above, the refrigerant that cools the reactor 30 circulates in the space closed by the case-side passage 20w, which is the space below the floor surface 20a of the converter case 14a, and the cover-side passage 26w of the lower cover 26. .. As described above, after cooling the electrical equipment in the inverter module 12 (see FIG. 1) mounted on the upper side of the converter module 14, it passes through the resin water channel 16 and the joint 22b to enter the converter case 14a. Inflow to. As described above, the floor surface 20a forming the refrigerant passage leading to the joint 22b is displaced toward the lower cover 26 toward the inside of the converter case 14a. That is, the floor surface 20a is closer to the lower cover 26 toward the inside of the converter case 14a. Here, if the distance between the floor surface 20a and the lower cover 26 becomes small and the cross-sectional area of the refrigerant passage through which the refrigerant circulates suddenly changes, the pressure loss when the refrigerant flows increases. When the pressure loss when the refrigerant flows becomes large, it is necessary to increase the capacity of the water pump that circulates the refrigerant.

In the lower cover 26 of the converter module 14 of the embodiment, the cover side passage 26w is engraved from the boundary surface 24. As described above, the cover side passage 26w is a wall defining the refrigerant passage. Therefore, the refrigerant that has flowed into the converter case 14a from the joint 22b circulates in the refrigerant passage defined by the case-side passage 20w and the cover-side passage 26w that continue to the joint 22b. Further, as shown in FIG. 4, in the slope portion of the floor surface 20a that is displaced toward the lower cover 26 toward the inside of the converter case 14a, the portion of the cover side passage 26w that faces the slope portion of the floor surface 20a is a boundary. It is displaced from the surface 24 to the side opposite to the case body 20. In other words, the portion of the cover-side passage 26w facing the slope of the floor surface 20a is displaced so as not to reduce the cross-sectional area of the refrigerant passage. Therefore, even in the portion where the floor surface 20a is displaced toward the lower cover 26 side, the refrigerant passage is formed with a diameter d2 substantially the same as the diameter d1 of the joint 22b portion. In other words, the cross section of the refrigerant passage is almost unchanged. At least it doesn't change suddenly. Therefore, in the converter module 14 disclosed in the present specification, the pressure loss when the refrigerant flows through the refrigerant passage can be reduced.

Further, as shown in FIGS. 4 and 5, the lower end of the cover side passage 26w and the lower end of the rib 26b of the lower cover 26 are substantially the same. That is, the entire thickness of the lower cover 26 is not increased by engraving the cover side passage 26w on the lower cover 26 side. Therefore, according to the converter module 14 disclosed in the present specification, it is possible to reduce the pressure loss when the refrigerant flows through the refrigerant passage without changing the size of the entire converter module 14.

The points to be noted in the examples are described below. The power controller of the embodiment is a converter module, but the techniques disclosed herein are not limited thereto. Further, the electric device cooled by the refrigerant is not limited to the reactor 30, and other electric devices such as a condenser may be used. Further, in FIG. 4, the refrigerant passage on the lower side of the reactor 30 is formed at a constant height, but the height of the refrigerant passage may be changed in consideration of air accumulation in the refrigerant passage and the like.

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 illustrated above. The technical elements described in the present specification or drawings exhibit 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 illustrated in the present specification or drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

2: Hybrid vehicle 4: Front compartment 6: Engine 8: Transaxle 10: Power control device 12: Inverter module 14: Converter module 16: Resin water channel 18: Radiator 20: Converter case 20a: Floor surface 20w: Case side passage 22: Connection surface 22a, 22b: Joint 24: Boundary surface 25: Rubber packing 26: Lower cover 26w: Cover side passage 26b: Rib 28, 29: Bolt 30: Reactor

Claims (1)

It is a power control device installed in an electric vehicle.
It houses at least a part of the electric equipment that supplies electric power to the traveling motor of the electric vehicle, and has a housing in which a refrigerant passage for circulating the refrigerant that cools the housed electric equipment is formed. ,
The housing is formed by combining the housing body and the cover.
The housing body includes a surface that intersects the refrigerant passage and a surface that extends along the refrigerant passage.
A joint portion for communicating the refrigerant passage with the external refrigerant pipe is provided on the surface intersecting the refrigerant passage.
The surface extending along the refrigerant passage is engraved with a wall that is a part of the wall defining the refrigerant passage and the cover side is open.
On the cover side, a wall that is a part of the wall that defines the refrigerant passage and the housing body side is open is engraved.
By combining the housing body and the cover, the refrigerant passage closed by the wall on the housing body side and the wall on the cover side is formed.
The electric power characterized in that the wall on the cover side following the joint portion is displaced toward the anti-housing body side from the position where the cover intersects the surface of the housing body that intersects with the refrigerant passage. Control device.

Images