JP7252104B2 - Grounding structure for vehicle power control unit - Google Patents

Description

The present invention relates to a grounding structure for a vehicle power control unit.

For example, Patent Literature 1 describes a hybrid vehicle having an engine and a motor as drive sources. A vehicle equipped with such a motor is equipped with a power control unit (PCU) that controls power used in the vehicle.

The power control unit is electrically connected to the chassis body of the vehicle via a ground cable. Also, in order to more reliably connect the power control section to the chassis body, the ground path is duplicated. Specifically, for example, the power control unit and the chassis body are connected by two ground cables.

JP 2018-76024 A

In a vehicle equipped with a motor as described above, for example, a large vehicle such as a bus may have two power control units. In this case, if two earth cables are connected to each power control section in order to duplicate the earth path, the number of earth cables increases, the structure becomes complicated, and assembly takes time. Or, the possibility of forgetting to attach the ground cable increases.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a grounding structure for a vehicle power control unit that enables simplification of the grounding structure in a vehicle having two power control units.

A grounding structure for a vehicle power control unit according to the present invention includes a first power control unit and a second power control unit that control power of a vehicle running using a motor, and a first power control unit and a second power control unit. a chassis body of the vehicle that supports the unit; a first ground cable that connects the first power control unit and the chassis body; a second ground cable that connects the second power control unit and the chassis body; and a conductive bracket connecting the power control unit and the second power control unit, the first power control unit has a first housing to be at the same potential as the chassis body, and the second power control unit is connected to the chassis body. It has a second housing to be at the same potential as the body, a first ground cable electrically connects the first housing and the chassis body, and a second ground cable connects the second housing and the chassis body. and the conductive bracket electrically connects the first housing and the second housing.

In this ground structure of the vehicle power control unit, the first housing of the first power control unit and the second housing of the second power control unit are electrically connected by the conduction bracket. Also, the first housing is electrically connected to the chassis body by a first ground cable, and the second housing is electrically connected to the chassis body by a second ground cable. That is, the first power control unit includes, as a ground path connecting the first housing and the chassis body, a ground path via the first cable and a ground path via the conduction bracket, the second housing, and the second ground cable. It has two ground paths for ground paths. Similarly, the second power control unit includes, as a ground path connecting the second housing and the chassis body, a ground path via the second cable, a conductive bracket, the first housing, and the first ground cable. It has two ground paths, one ground path and one ground path. Thus, by connecting the first housing and the second housing with the conduction bracket, the first power control unit and the second power control unit can be connected without connecting two ground cables to one power control unit. Two ground paths may be provided for each of the power controls. Therefore, the ground structure of the vehicle power control unit can be simplified in a vehicle having two power control units.

In the ground structure of the vehicle power control unit, the conductive bracket may have a bracket main body and a conductive plating layer provided on the surface of the bracket main body. In this case, the conductive bracket can electrically connect the first housing and the second housing while suppressing rusting of the bracket main body by the plated layer.

In the ground structure of the vehicle power control unit, an in-vehicle component mounted on the vehicle may be fixed to the conduction bracket. In this case, in the ground structure of the vehicle power control unit, the conduction bracket that electrically connects the first housing and the second housing can function as a member that supports the vehicle-mounted component.

The vehicle-mounted component may be an electrical component of a vehicle. In this case, in the ground structure of the vehicle power control unit, the conductive bracket can function as a member that supports the electrical components of the vehicle.

The vehicle power control unit ground structure further includes a support frame on which the first power control unit and the second power control unit are mounted and fixed to the chassis body, and the conduction bracket is mounted on the upper surface of the first housing. may be connected to the upper surface of the second housing. In this case, in the ground structure of the vehicle power control unit, even if the support frame supports the lower surfaces of the first power control unit and the second power control unit, the conductive bracket can be easily attached and detached from above. be able to.

According to the present invention, it is possible to simplify the grounding structure in a vehicle having two power control units.

FIG. 1 is a diagram showing a schematic configuration of main parts of a vehicle according to the embodiment. FIG. 2 is a diagram showing a schematic configuration around the first PCU and the second PCU to which the ground structure of the vehicle power control unit is applied. FIG. 3 is a diagram for explaining the flow of ground current when the second ground cable is not connected in FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle to which a grounding structure for a vehicle power control unit according to the present invention is applied will be described below with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

As shown in FIG. 1, the vehicle V includes an engine 2, a motor 3, a transmission 4, and drive wheels W as components around the drive system. A vehicle V is a hybrid vehicle having an engine 2 and a motor 3 as drive sources. The vehicle V runs using at least one of the engine 2 and the motor 3 as a drive source. The driving force of the engine 2 and the motor 3 is transmitted to the drive wheels W via the transmission 4 and the like.

The vehicle V also includes a power control device 1 . The power control device 1 includes a first PCU (Power Control Unit) 11 and a second PCU 21 . The first PCU 11 and the second PCU 21 use the motor 3 to control the electric power of the vehicle V running.

More specifically, the first PCU 11 (first power control unit) controls power supplied from the battery to the motor 3 . Also, the first PCU 11 controls electric power generated by the motor 3 performing regenerative power generation. The first PCU 11 performs, for example, conversion of voltage, conversion between direct current and alternating current, etc., as power control. The first PCU 11 includes various circuits such as an inverter to realize these functions. Similarly, the second PCU 21 (second power control unit) controls power supplied to the motor 3 from the battery. Also, the second PCU 21 controls electric power generated by the motor 3 performing regenerative power generation. The second PCU 21 performs, for example, conversion of voltage, conversion between direct current and alternating current, etc., as power control. The second PCU 21 has various circuits such as an inverter, for example, in order to realize these functions.

Here, the power control device 1 controls the power supplied from the battery by using the first PCU 11 and the second PCU 21 , and supplies the motor 3 with the combined outputs of the first PCU 11 and the second PCU 21 . For example, if the vehicle V is a large vehicle such as a bus, it is necessary to supply a large amount of electric power to the motor 3 . Even in such a case, since the power control device 1 includes two PCUs (the first PCU 11 and the second PCU 21), a large amount of power can be supplied to the motor 3. However, the vehicle V in this embodiment is not limited to a large vehicle such as a bus. The vehicle V only has to include the power control device 1 having two PCUs (the first PCU 11 and the second PCU 21).

Next, the configuration around the first PCU 11 and the second PCU 21 to which the grounding structure 100 of the vehicle power control unit is applied will be described with reference to FIG. In the following description, "front", "rear", "left", and "right" are directions with respect to the vehicle V. FIG.

As shown in FIG. 2, the first PCU 11 and the second PCU 21 are supported by the chassis body 5 of the vehicle V. As shown in FIG. Various parts such as parts around the drive system such as the engine 2 and the motor 3, parts around the wheel shaft, and a passenger compartment are attached to the chassis body 5 . Here, the chassis body 5 has a left chassis body 10 and a right chassis body 20 extending along the longitudinal direction of the vehicle V. As shown in FIG.

The left chassis body 10 and the right chassis body 20 are made of a conductive metal material such as iron. The left chassis body 10 and the right chassis body 20 are connected to each other by a lateral frame or the like extending along the left-right direction, and are electrically at the same potential. The chassis body 5 (the left chassis body 10 and the right chassis body 20) is connected to the negative terminal of the battery mounted on the vehicle V via an earth cable or the like.

A vehicle V includes a support frame 40 fixed to the left chassis body 10 and the right chassis body 20 . The support frame 40 has a lower frame 41 extending in the left-right direction, a plurality of struts 42 rising upward from the lower frame 41 , and an upper frame 43 fixed on the struts 42 . there is The lower frame 41 is fixed to the left chassis body 10 and the right chassis body 20 respectively. The first PCU 11 and the second PCU 21 are placed on the upper frame 43 . Note that the first PCU 11 is arranged on the left side of the second PCU 21 on the upper frame 43 .

Here, the first PCU 11 includes a first power control circuit 11a having an inverter and the like, and a first housing 11b that houses the first power control circuit 11a. The first housing 11b is a part to be connected to the negative terminal of the battery mounted on the vehicle V. As shown in FIG. That is, the first housing 11b is a portion that should be at the same potential as the chassis body 5. As shown in FIG. Similarly, the second PCU 21 includes a second power control circuit 21a having an inverter and the like, and a second housing 21b that houses the second power control circuit 21a. The second housing 21b is a part to be connected to the negative terminal of the battery mounted on the vehicle V. As shown in FIG. That is, the second housing 21b is a portion that should be at the same potential as the chassis body 5. As shown in FIG.

The vehicle V also includes a first earth cable 12 and a second earth cable 22 . The first ground cable 12 electrically connects the first housing 11 b (first PCU 11 ) and the left chassis body 10 . The second ground cable 22 electrically connects the second housing 21 b (second PCU 21 ) and the right chassis body 20 . Although not shown, a plus cable (cable for power supply) is also connected to the first PCU 11 and the second PCU 21 .

The vehicle V also includes a conduction bracket 30 that connects the first PCU 11 and the second PCU 21 . More specifically, the conduction bracket 30 electrically connects the first housing 11b and the second housing 21b. The conductive bracket 30 has a bracket body portion 30a and a plated layer 30b. The bracket body portion 30a is made of a metal material such as iron. The plated layer 30b is provided on the surface of the bracket body portion 30a and has electrical conductivity. Various well-known plated layers can be used as the conductive plated layer 30b.

One end of the conduction bracket 30 is in contact with the upper surface of the first housing 11b. The other end of the conduction bracket 30 is in contact with the upper surface of the second housing 21b. That is, the first housing 11b and the second housing 21b are electrically connected to each other via the conduction bracket 30 (plating layer 30b). The plated layer 30b has a function of preventing the bracket main body 30a from rusting and a function of electrically connecting the first housing 11b and the second housing 21b.

Various in-vehicle components mounted on the vehicle V can be fixed to the conduction bracket 30 . In this embodiment, for example, a fuse box (electrical component) 50 is fixed to the conductive bracket 30 as an in-vehicle component. This fuse box 50 may be a fuse box connected to at least one of the first PCU 11 and the second PCU 21 . Electrical components other than the fuse box 50 may be fixed to the conduction bracket 30 .

Next, the flow of ground current when the second ground cable 22 is not connected will be described. A state in which the second ground cable 22 is not connected means a state in which the second housing 21 b and the right chassis body 20 are not electrically connected by the second ground cable 22 . This state can occur, for example, when the connection between the second ground cable 22 and the right chassis body 20 is disconnected or the connection is forgotten during assembly, as shown in FIG.

In this case, as indicated by arrows in FIG. and flows to the left chassis body 10 (chassis body 5). That is, even if the second ground cable 22 is not connected, the ground path of the second PCU 21 is secured.

As described above, in the grounding structure 100 of the vehicle power control unit, the second PCU 21 connects the second grounding cable 22 with the grounding path through the conductive bracket 30, the first housing 11b, and the first grounding cable 12 described above. It has two ground paths, one through and one through. That is, the ground path is duplicated. Therefore, even if one of the two ground paths is disconnected, the second PCU 21 can secure the ground path through the other.

Similarly, when the first ground cable 12 is not connected, the ground current from the first housing 11b to the chassis body 5 flows through the conductive bracket 30 (plating layer 30b), the second housing 21b, and the second ground cable 22. to the right chassis body 20 (chassis body 5). That is, even if the first ground cable 12 is not connected, the ground path of the first PCU 11 is secured.

Thus, in the grounding structure 100 of the vehicle power control unit, the first PCU 11 connects the first grounding cable 12 with the grounding path through the conductive bracket 30, the second housing 21b, and the second grounding cable 22 described above. It has two ground paths, one through and one through. That is, the ground path is duplicated. Therefore, even if one of the two ground paths is disconnected, the first PCU 11 can secure the ground path through the other.

As described above, in the grounding structure 100 for the vehicle power control unit, the first housing 11b of the first PCU 11 and the second housing 21b of the second PCU 21 are electrically connected by the conduction bracket 30 . The first housing 11b is electrically connected to the left chassis body 10 (chassis body 5) by a first ground cable 12, and the second housing 21b is electrically connected to the right chassis body 20 (chassis body 5) by a second ground cable 22. ) is electrically connected to That is, the first PCU 11 has two ground paths as ground paths connecting the first housing 11 b and the chassis body 5 . Similarly, the second PCU 21 has two ground paths as ground paths connecting the second housing 21 b and the chassis body 5 .

Thus, by connecting the first housing 11b and the second housing 21b with the conductive bracket 30, the first PCU 11 and the second PCU 21 can be connected to each of the first PCU 11 and the second PCU 21 without connecting two ground cables to one PCU. Two ground paths can be provided for . Therefore, in the vehicle power control unit grounding structure 100, it is possible to simplify the grounding structure in the vehicle V including the two power control units (the first PCU 11 and the second PCU 21). In the vehicle power control unit grounding structure 100, it is not necessary to connect two grounding cables to one PCU.

The conductive bracket 30 has a plated layer 30b covering the surface of the bracket body 30a. In this case, the conductive bracket 30 can electrically connect the first housing 11b and the second housing 21b with the plated layer 30b while suppressing rusting of the bracket main body 30a. Further, the conductive bracket 30 can easily electrically connect the first housing 11b and the second housing 21b simply by bringing the plated layer 30b into contact with the first housing 11b and the second housing 21b. .

An in-vehicle component mounted on the vehicle V may be fixed to the conduction bracket 30 . In this case, the conduction bracket 30 can function as a member that supports the vehicle-mounted component.

The vehicle-mounted component may be a fuse box 50 as an electrical component of the vehicle V. FIG. In this case, in the vehicle power control unit grounding structure 100 , the conduction bracket 30 can function as a member that supports the fuse box 50 arranged around the first PCU 11 and the second PCU 21 .

The first PCU 11 and the second PCU 21 are placed on the support frame 40 . The conduction bracket 30 connects the upper surface of the first PCU 11 and the upper surface of the second housing 21b. In this case, in the grounding structure 100 of the vehicle power control unit, even if the lower surfaces of the first PCU 11 and the second PCU 21 are supported by the support frame 40, the conduction bracket can be connected from above without being obstructed by the support frame 40. 30 can be easily attached and detached.

Here, the upper frame 43 of the support frame 40 requires strength in order to support the first PCU 11 and the second PCU 21 and is larger in size than the conduction bracket 30 . Therefore, if a plated layer is provided on the upper frame 43 and the upper frame 43 is used to electrically connect the first housing 11b and the second housing 21b, the plated layer is required more than when the conductive bracket 30 is used. The area becomes large, and the plating process takes time and effort, and the cost increases. For this reason, as in the above-described embodiment, by providing the plated layer 30b on the conductive bracket 30 different from the upper frame 43 and electrically connecting the first housing 11b and the second housing 21b, the plated layer is removed. The range to be provided can be suppressed, and the labor and cost of the plating process can be reduced.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, the conduction bracket 30 may not have the plated layer 30b as long as it can electrically connect the first housing 11b and the second housing 21b. In this case, the conductive bracket 30 may be configured to electrically connect the first housing 11b and the second housing 21b by the bracket body portion 30a.

At least part of the embodiments and various modifications described above may be combined arbitrarily.

3 Motor 5 Chassis body 11 First PCU 11b First housing 12 First ground cable 21 Second PCU 21b Second housing 22 Second ground cable 30 Continuity Bracket 30a Bracket main body 30b Plated layer 40 Support frame 50 Fuse box (on-vehicle component, electrical component) 100 Grounding structure of vehicle power control unit V Vehicle.

Claims (5)

a first power control unit and a second power control unit that control power of a vehicle running using a motor;
a chassis body of the vehicle that supports the first power control unit and the second power control unit;
a first ground cable connecting the first power control unit and the chassis body;
a second ground cable connecting the second power control unit and the chassis body;
a conduction bracket that connects the first power control unit and the second power control unit;
with
The first power control unit has a first housing that should be at the same potential as the chassis body,
The second power control unit has a second housing that should be at the same potential as the chassis body,
the first ground cable electrically connects the first housing and the chassis body;
the second ground cable electrically connects the second housing and the chassis body;
The conductive bracket is a ground structure for a vehicle electric power control unit, electrically connecting the first housing and the second housing. The conduction bracket is
a bracket body;
a conductive plating layer provided on the surface of the bracket main body;
2. The grounding structure for a vehicle power control unit according to claim 1, comprising: 3. The grounding structure for a vehicle power control unit according to claim 1, wherein an on-vehicle component mounted on said vehicle is fixed to said conduction bracket. 4. The grounding structure for a vehicle power control unit according to claim 3, wherein said in-vehicle component is an electrical component of said vehicle. a support frame on which the first power control unit and the second power control unit are placed and fixed to the chassis body;
5. The grounding structure for a vehicle power control unit according to claim 1, wherein said conductive bracket connects an upper surface of said first housing and an upper surface of said second housing.

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