Electric vehicle

Abstract

The invention provides an electric vehicle capable of improving cooling performance of a motor and a power control device. A cooling oil passage for cooling the motor and discharging the oil discharged from the oil pump to the motor is disposed between the motor and the power control device, and the power control device is disposed adjacent to the motor above the vertical direction. As a result, both the motor and the power control device are cooled by the oil discharged from the cooling oil passage, and heat generation of the motor and the power control device can be suppressed. Therefore, the cooling performance of the motor and the power control device can be improved.

Description

Technical Field

[0001] The present invention relates to an electric vehicle equipped with a cooling oil circuit for spraying oil to the electric motor for cooling the electric motor. Background Art

[0002] An electric vehicle is known, which is equipped with: an electric motor, a power transmission device connected to the electric motor for power transmission, a driving battery, a power control device for controlling the power exchanged between the battery and the electric motor, and a housing that accommodates a drive device including the electric motor and the power transmission device and the power control device as a mechatronic unit. For example, the mechatronic device described in Patent Document 1 is of this type. Patent Document 1 discloses the following: a partition wall is provided in the housing, a part of the power control device is arranged on the upper surface of the partition wall in the vertical direction, and the other part is arranged on the lower surface of the partition wall in the vertical direction, and a cooling flow path for the flow of liquid refrigerant is provided inside the partition wall.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-161294 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in the mechatronic unit, an electric power control device is mounted vertically above and adjacent to the electric motor. For miniaturization, it is necessary to shorten the physical distance between the electric motor and the electric power control device. Thus, for example, in the mechatronic device described in Patent Document 1, other parts of the electric power control device and the electric motor are easily heated by each other due to the ambient temperature, the housing, etc. It is desirable to suppress the heating of the electric power control device. In addition, since the electric motor is easily demagnetized and its performance is reduced due to heat, it is desirable to suppress the heating. It is also well known that electric vehicles are equipped with a cooling oil circuit in which the oil discharged by the oil pump is sprayed to the electric motor for cooling the electric motor. There is still room for improvement in the use of such a cooling oil circuit.

[0008] The present invention is based on the above situation, and an object of the present invention is to provide an electric vehicle capable of improving the cooling performance of a motor and a power control device.

[0009] Means of solving problems

[0010] The main purpose of the first invention is that (a) an electric vehicle is equipped with: an electric motor; a power transmission device, the power transmission device is connected to the electric motor so as to be able to transmit power; a battery for driving; a power control device, the power control device controls the power exchanged between the battery and the electric motor; a housing, the housing accommodating a drive device including the electric motor and the power transmission device and the power control device as a mechatronic unit; an oil pump for discharging oil; and a cooling oil circuit, the cooling oil circuit sprays the oil to the electric motor for cooling the electric motor, (b) the power control device is arranged adjacent to and above the electric motor in a vertical direction when mounted on the electric vehicle, and (c) the cooling oil circuit is arranged between the electric motor and the power control device.

[0011] According to a second invention, in the electric vehicle according to the first invention, a plurality of power lines electrically connecting the electric motor and the power control device are further provided, and the cooling oil passage is arranged between any two of the plurality of power lines.

[0012] Moreover, a third invention is the electric vehicle according to the second invention, wherein the two power lines are two power lines having a short path among the plurality of power lines.

[0013] In addition, the fourth invention is that in the electric vehicle recorded in the second invention, the power control device is equipped with an inverter, the inverter has a three-phase bridge circuit of U phase, V phase and W phase, the motor is a three-phase AC synchronous motor driven by the inverter, and the multiple power lines are three power lines through which the three-phase AC current of U phase, V phase and W phase flows.

[0014] Moreover, according to a fifth invention, in the electric vehicle according to the fourth invention, the two power lines are two power lines having a short path among the three power lines.

[0015] In addition, the sixth invention is that in the electric vehicle recorded in any one of the second invention to the fifth invention, a terminal board is also provided, which connects a plurality of motor-side power lines connected to the motor among the plurality of power lines and a plurality of power control device-side power lines connected to the power control device among the plurality of power lines, and any two of the power lines are any two of the plurality of motor-side power lines arranged between the motor and the terminal board.

[0016] In addition, the seventh invention is that, in the electric vehicle recorded in any one of the first to sixth inventions, the electric motor includes a first electric motor and a second electric motor, and when the drive device is mounted on the electric vehicle, the rotation axis of the first electric motor, the rotation axis of the second electric motor, and the rotation axis of the power transmission device are respectively arranged in a manner parallel to the horizontal direction perpendicular to the forward and backward direction of the electric vehicle, and are arranged in the order of the rotation axis of the second electric motor and the rotation axis of the first electric motor from the top to the bottom in the vertical direction, and when the power control device is mounted on the electric vehicle, the vertical lower part is arranged at a position overlapping with the vertical upper part of the second motor when viewed in the forward and backward direction, and the vertical lower part is arranged above the vertical direction relative to the first motor, and the cooling oil circuit is arranged between the first motor and the vertical lower part of the power control device.

[0017] According to an eighth invention, in the electric vehicle according to any one of the first to seventh inventions, the direction of the cooling oil passage is the same as the direction of the rotation axis of the electric motor.

[0018] Effects of the Invention

[0019] According to the first invention, the cooling oil circuit for spraying the oil discharged from the oil pump to the motor for cooling the motor is arranged between the motor and the electric control device, and the electric control device is arranged adjacent to the motor in the vertical direction. Thus, the motor and the electric control device are cooled by the oil sprayed from the cooling oil circuit, and the heat generation of the motor and the electric control device can be suppressed. Therefore, the cooling performance of the motor and the electric control device can be improved.

[0020] In addition, according to the second invention, the cooling oil circuit is arranged between any two power lines among a plurality of power lines electrically connecting the motor and the power control device. Since the power line is shortened when the physical distance between the motor and the power control device is shortened, the heat dissipation of the power line is deteriorated, and the motor and the power control device are easily heated by each other. In contrast, according to the second invention, the power line is cooled by the oil sprayed from the cooling oil circuit, and the heating between the motor and the power control device can be suppressed.

[0021] According to the third invention, the two power lines are two power lines with short paths among the plurality of power lines. Therefore, the power lines with short paths have poorer heat dissipation than power lines with long paths, and the power lines with short paths are cooled, so that the heat received by the motor and the power control device can be efficiently suppressed.

[0022] Furthermore, according to the fourth invention, since the plurality of power lines are three power lines through which three-phase alternating currents of U phase, V phase, and W phase flow, the cooling oil passage is disposed between any two of the three power lines through which three-phase alternating currents flow. Thus, the power lines are cooled by the oil ejected from the cooling oil passage, and the mutual heat between the motor and the power control device can be suppressed.

[0023] According to the fifth invention, the two power lines are two power lines with short paths among the three power lines. Therefore, the power lines with short paths have poorer heat dissipation than power lines with long paths, and the power lines with short paths are cooled, which can effectively suppress the heat between the motor and the power control device.

[0024] According to the sixth invention, the two power lines are any two of the plurality of motor-side power lines disposed between the motor and the terminal board. Thus, the cooling oil path is disposed between any two of the plurality of motor-side power lines. Thus, the power lines are cooled by the oil ejected from the cooling oil path, and the heat received by the motor and the power control device can be appropriately suppressed.

[0025] In addition, according to the seventh invention, the drive device is arranged in the order of the rotation axis of the second motor and the rotation axis of the first motor from the upper direction to the lower direction in the vertical direction. In addition, the lower vertical side portion of the electric power control device is arranged at a position overlapping with the upper vertical side portion of the second motor when viewed in the forward and backward directions, and the lower vertical side portion is arranged above the first motor in the vertical direction. In addition, the cooling oil circuit is arranged between the first motor and the lower vertical side portion of the electric power control device. Thus, both the first motor and the lower vertical side portion of the electric power control device are cooled by the oil sprayed from the cooling oil circuit, which can suppress the heating of the motor and the electric power control device.

[0026] In addition, according to the eighth invention, the direction of the cooling oil passage is the same as the direction of the rotation axis of the motor. Thus, the cooling oil can flow down from the upper side in the vertical direction to the lower side in the vertical direction over the entire length of the rotation axis of the motor, and the entire motor can be efficiently cooled. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a diagram for explaining an example of a schematic structure of an electric vehicle to which the present invention is applied.

[0028] Figure 2 This is a diagram for explaining an example of an electrical configuration related to motor control and the like.

[0029] Figure 3This is a diagram for explaining an example of a schematic structure of a mechatronic unit.

[0030] Figure 4 This is a diagram for explaining an example of a cooling system using oil.

[0031] Figure 5 This is a diagram for explaining an example of the structure of a cover of a housing in a cooling system using oil.

[0032] Figure 6 This is a diagram for explaining an example of a cooling system in which cooling pipes are arranged between bus bars.

[0033] Figure 7 This is a diagram showing an example of the mounting range of the cooling pipe.

[0034] Figure 8 is a diagram for explaining an example of a schematic structure of an electric vehicle to which the present invention is applied, and is Figure 1 Different embodiments of the electric vehicle. DETAILED DESCRIPTION

[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0036] Example

[0037] Figure 1 FIG. 1 is a diagram for explaining an example of a schematic structure of an electric vehicle 10 to which the present invention is applied. Figure 1 In the embodiment, the electric vehicle 10 is a hybrid vehicle equipped with an engine 12 serving as a power source and a second electric motor MG2 serving as a power source. In addition, the electric vehicle 10 is equipped with drive wheels 14, a power transmission device 16, and a first electric motor MG1.

[0038] The engine 12 is a well-known internal combustion engine. The drive wheels 14 are left and right wheels with respect to the forward and backward directions of the electric vehicle 10. The power transmission device 16 is provided in the power transmission path between the engine 12 and the drive wheels 14 and the power transmission path between the second motor MG2 and the drive wheels 14.

[0039] The first motor MG1 and the second motor MG2 are known rotary electrical machines that function as an engine that generates mechanical power from electric power and as a generator that generates electric power from mechanical power, respectively, and are so-called motor generators. The first motor MG1 and the second motor MG2 are arranged in a non-rotatable housing 18 that is a non-rotating member mounted on the vehicle body.

[0040] The power transmission device 16 is provided with a shock absorber 20, an input shaft 22, a speed change unit 24, a compound gear 26, a driven gear 28, a driven shaft 30, a final drive gear 32, a differential gear 34, a reduction gear 36, etc. in a housing 18. In addition, the power transmission device 16 is provided with a pair of transmission shafts 38 connected to the differential gear 34, etc.

[0041] The damper 20 is connected to the crankshaft 12a of the engine 12. The input shaft 22 functions as an input rotating member of the speed change unit 24. The input shaft 22 is connected to the damper 20, and is connected to the crankshaft 12a via the damper 20 and the like. The speed change unit 24 is connected to the input shaft 22. The composite gear 26 is a rotating body on the output side of the speed change unit 24. The composite gear 26 forms a transmission gear 26a on a part of the outer peripheral surface. The transmission gear 26a is an output rotating member of the speed change unit 24. The driven gear 28 meshes with the transmission gear 26a. The driven shaft 30 is fixedly provided with the driven gear 28 and the final transmission gear 32 so as to be non-rotatable relative to each other. The final transmission gear 32 has a smaller diameter than the driven gear 28 and meshes with the differential ring gear 34a. The reduction gear 36 has a smaller diameter than the driven gear 28 and meshes with the driven gear 28. The rotor shaft of the second electric motor MG2 is connected to the reduction gear 36 , and the second electric motor MG2 is connected in a power-transmittable manner.

[0042] The power transmission device 16 thus configured is preferably suitable for a vehicle of FF (front engine front wheel drive) type or RR (rear engine rear wheel drive) type. The power transmission device 16 transmits the power output from the engine 12 to the driven gear 28 via the transmission unit 24. In addition, the power transmission device 16 transmits the power output from the second electric motor MG2 to the driven gear 28 via the reduction gear 36. The power transmission device 16 transmits the power transmitted to the driven gear 28 to the drive wheel 14 via the driven shaft 30, the final drive gear 32, the differential gear 34, the transmission shaft 38, etc. in sequence. The driven gear 28, the driven shaft 30, and the final drive gear 32 are a transmission mechanism for transmitting the power from the second electric motor MG2 to the differential gear 34, and are a transmission mechanism for transmitting the power from the transmission gear 26a to the differential gear 34. The differential gear 34 distributes the power from the engine 12 or the second electric motor MG2 to the drive wheel 14. The transmission shaft 38 transmits the power from the differential gear 34 to the drive wheel 14. The second electric motor MG2 is connected to the drive wheels 14 in a power-transmittable manner.

[0043] The speed change unit 24 is equipped with a first electric motor MG1 and a differential mechanism 40. The differential mechanism 40 is a well-known single pinion type planetary gear device equipped with a sun gear S, a planetary gear carrier CA and a ring gear R. The sun gear S is connected to the rotor shaft of the first electric motor MG1. That is, the differential mechanism 40, which is a part of the power transmission device 16, can be connected to the first electric motor MG1, which is an electric motor, in a power transmission manner. The planetary gear carrier CA is connected to the input shaft 22. That is, the differential mechanism 40 is connected to the engine 12 in a power transmission manner via the input shaft 22, etc. The ring gear R is formed on a part of the inner circumferential surface of the compound gear 26 and is integrally connected to the transmission gear 26a. That is, the differential mechanism 40 is connected to the drive wheel 14 in a power transmission manner.

[0044] The differential mechanism 40 functions as a differential mechanism that generates a differential action and is connected to the engine 12 in a power-transmittable manner. The first electric motor MG1 is a differential electric motor that is connected to the differential mechanism 40 in a power-transmittable manner. The differential mechanism 40 is a power distribution mechanism that mechanically distributes the power of the engine 12 input to the planetary gear carrier CA to the first electric motor MG1 and the transmission gear 26a. The speed change unit 24 is a well-known electric speed change mechanism that controls the differential state of the differential mechanism 40 by controlling the operating state of the first electric motor MG1.

[0045] The power transmission device 16 has a first axis CL1, a second axis CL2, a third axis CL3 and a fourth axis CL4. These four axes CL1, CL2, CL3 and CL4 are parallel to each other. The first axis CL1 is the axis center of the input shaft 22 and the rotor shaft of the first motor MG1. That is, the first axis CL1 is the rotation axis of the first motor MG1. The speed change unit 24 and the first motor MG1 are arranged around the first axis CL1. The second axis CL2 is the axis center of the driven shaft 30. The driven gear 28 and the final transmission gear 32 are arranged around the second axis CL2. That is, the second axis CL2 is the rotation axis of the driven gear 28, the driven shaft 30 and the final transmission gear 32. The third axis CL3 is the axis center of the rotor shaft of the second motor MG2. That is, the third axis CL3 is the rotation axis of the second motor MG2. The second motor MG2 and the reduction gear 36 are arranged around the third axis CL3. The fourth axis CL4 is the axis center of the transmission shaft 38 and the axis center of the differential gear 34. That is, the fourth axis CL4 is the rotation axis of the propeller shaft 38 and the differential gear 34 . The differential gear 34 is arranged around the fourth axis CL4 . The second axis CL2 and the fourth axis CL4 are the rotation axes of the power transmission device 16 .

[0046] The housing 18 is provided with a housing 18a, a housing body 18b and a cover 18c. The engine block 12b of the engine 12 is connected to the opened portion of the housing 18a on the engine 12 side. The housing 18a and the housing body 18b are connected as one piece by a fastener such as a bolt in such a manner that the opened portion of the housing 18a on the opposite side of the engine 12 matches the opened portion of the housing body 18b on the engine 12 side. The housing body 18b and the cover 18c are connected as one piece by a fastener in such a manner that the opened portion of the housing body 18b on the opposite side of the engine 12 is blocked by the cover 18c. The housing body 18b is a housing configured to include a partition wall not shown in the figure, which separates the gear chamber Rg accommodating the speed change unit 24, the driven gear 28, the differential gear 34, etc. from the motor chamber Rm accommodating the first motor MG1 and the second motor MG2. The housing body 18b and the housing 18a form the gear chamber Rg. The housing body 18b and the cover 18c form a motor chamber Rm. Thus, the housing 18 accommodates the first motor MG1, the second motor MG2, and the power transmission device 16 except for the transmission shaft 38 and the like.

[0047] Figure 2 1 is a diagram for explaining an example of an electrical configuration related to control of the first electric motor MG1 and the second electric motor MG2. Figure 2 In the embodiment, the electric vehicle 10 is further equipped with a high-voltage battery 50, an auxiliary battery 52, a power control unit 54, and the like.

[0048] The high-voltage battery 50 is a rechargeable DC power source, such as a secondary battery such as a nickel-metal hydride secondary battery or a lithium-ion battery. The high-voltage battery 50 is connected to a power control unit 54. The stored power is supplied from the high-voltage battery 50 to, for example, the second motor MG2 via the power control unit 54. In addition, the power generated by the power generation control of the first motor MG1 and the power generated by the regeneration control of the second motor MG2 are supplied to the high-voltage battery 50 via the power control unit 54. The high-voltage battery 50 is a driving battery.

[0049] The power control unit 54 includes a DCDC converter 56, a motor control device 58, a boost converter 60, an inverter 62, etc. The power control unit 54 is a power control device that controls the power transferred between the high voltage battery 50 and the first and second motors MG1 and MG2.

[0050] The DCDC converter 56 is connected to the high voltage battery 50. The DCDC converter 56 functions as a charging device that steps down the voltage of the high voltage battery 50 to a voltage equivalent to that of the auxiliary battery 52 to charge the auxiliary battery 52. ​​The auxiliary battery 52 supplies power for operating auxiliary machines, a motor control device 58, an electronic control device 70 to be described later, and the like provided in the electric vehicle 10.

[0051] The boost converter 60 is equipped with a reactor coil, a switching element, etc. (not shown in the figure). The boost converter 60 is a step-up / step-down circuit having the function of stepping up the voltage of the high-voltage battery 50 and supplying it to the inverter 62, and the function of stepping down the voltage converted into DC by the inverter 62 and supplying it to the high-voltage battery 50.

[0052] The inverter 62 is equipped with an MG1 power module 64, an MG2 power module 66, etc. The MG1 power module 64 is equipped with a plurality of transistors, etc., forming a three-phase bridge circuit of U phase, V phase, and W phase. The plurality of transistors, etc. are connected and disconnected as switching elements, thereby converting the direct current into a three-phase alternating current. The electric vehicle 10 is also equipped with a bus bar 68, and the first motor MG1 and the MG1 power module 64 (i.e., the inverter 62) are electrically connected through the bus bar 68. The bus bar 68 is a power line that electrically connects the first motor MG1 to the power control unit 54, and includes a plurality of bus bars 68u, 68v, and 68w. The plurality of bus bars 68u, 68v, and 68w are three power lines through which the three-phase alternating current of the U phase, the V phase, and the W phase flows. Since the MG2 power module 66 has the same structure as the MG1 power module 64, the description of the MG2 power module 66 is omitted. The first electric motor MG1 and the second electric motor MG2 are three-phase AC synchronous motors driven by the inverter 62 .

[0053] The inverter 62 converts the DC current from the boost converter 60 into an AC current for driving the first motor MG1 and the second motor MG2. The inverter 62 converts the AC current generated by the first motor MG1 by the power of the engine 12 and the AC current generated by the second motor MG2 by regenerative braking into a DC current. The inverter 62 provides the AC current generated by the first motor MG1 as driving power for the second motor MG2 according to the driving state.

[0054] The electric vehicle 10 is also equipped with an electronic control device 70, a communication line 72, etc. The electronic control device 70 sends and receives signals to and from the DCDC converter 56, the motor control device 58, etc. via the communication line 72. The electronic control device 70 performs various controls on the electric vehicle 10 based on signals from sensors, etc., which are not shown in the figure. The communication line 72 is, for example, a well-known CAN (Controller Area Network) communication line.

[0055] The motor control device 58 controls the boost converter 60 and the inverter 62 based on the instruction from the electronic control device 70, and controls the first motor MG1 and the second motor MG2. For example, the motor control device 58 converts the DC current from the high-voltage battery 50 into AC current for the first motor MG1 and the second motor MG2 respectively. In order to ensure the power supply to the second motor MG2 and the power generation required for charging the high-voltage battery 50, the motor control device 58 drives the first motor MG1. The motor control device 58 drives the second motor MG2 based on the output request value corresponding to the driver's request torque. The motor control device 58 functions as a generator for the second motor MG2 corresponding to the request amount of regenerative braking.

[0056] Figure 3 It is a diagram for explaining an example of a schematic structure of the driving unit 90 . Figure 3 2 is a side view of the left side of the electric vehicle 10. Figure 3 In the figure, the variable speed drive axle 92 and the power control unit 54 are contained in the same housing 18 as the drive unit 90. The drive unit 90 is a unit in which the variable speed drive axle 92 and the power control unit 54 are integrated, that is, a mechatronic unit. The variable speed drive axle 92 is a drive device including the power transmission device 16 (26a, 28, 32, 34a, 36, etc.), the first motor MG1, and the second motor MG2. In addition, the vertical direction, the forward and reverse direction, and the vehicle width direction (refer to Figure 5 ) indicates a direction in a state of being mounted on the electric vehicle 10. The vehicle width direction is the axis direction of each of the first axis CL1, the second axis CL2, the third axis CL3, and the fourth axis CL4.

[0057] In addition to the shell 18a, the shell body 18b, and the cover 18c, the shell 18 is also equipped with a protective plate 18d. The shell body 18b has a bottom wall and side walls, and the side walls extend from the outer peripheral edge of the bottom wall to the upper part in the vertical direction at the front side and the rear side in the forward and backward directions, respectively, and the upper part in the vertical direction of the shell body 18b is open. The protective plate 18d is a plate-shaped member that blocks the opening in the upper part in the vertical direction of the shell body 18b. The shell body 18b has a partition wall (not shown in the figure) inside, and the interior is divided into two spaces by the partition wall, namely, a lower space A as a space in the lower part in the vertical direction and an upper space B as a space in the upper part in the vertical direction.

[0058] The transaxle 92 is housed in the lower space A of the case body 18 b and the housing 18 a when mounted on the electric vehicle 10 .

[0059] The power control unit 54 is accommodated in the upper space B of the housing body 18b when mounted on the electric vehicle 10. The upper space B includes a remaining space B1 generated by the arrangement of the first motor MG1 and the second motor MG2 and an uppermost space B2 in the vertical direction above the second motor MG2. The remaining space B1 is shorter than the uppermost space B2 in the forward and backward directions. The power control unit 54 is arranged adjacent to the upper part of the first motor MG1 in the vertical direction when mounted on the electric vehicle 10.

[0060] In the remaining space B1, relatively short components or relatively easy-to-replace components in the power control unit 54, such as the DCDC converter 56 and a reactor (not shown) provided in the boost converter 60, are accommodated.

[0061] Reference Figure 3 , the transaxle 92 is arranged in a state where it is mounted on the electric vehicle 10 so that the first axis CL1, the second axis CL2, the third axis CL3 and the fourth axis CL4 are parallel to the horizontal direction perpendicular to the forward and backward direction of the electric vehicle 10. In addition, when the transaxle 92 is mounted on the electric vehicle 10, the positions of the first axis CL1, the second axis CL2, the third axis CL3 and the fourth axis CL4 form the order of the second motor MG2, the driven shaft 30, the first motor MG1 and the differential gear 34 from the top to the bottom in the vertical direction, and form the order of the first motor MG1, the driven shaft 30, the differential gear 34 and the second motor MG2 from the front to the rear in the forward and backward direction. If we focus on the first motor MG1 and the second motor MG2, the transaxle 92 is arranged in the order of the third axis CL3 and the first axis CL1 from the top to the bottom in the vertical direction when it is mounted on the electric vehicle 10. Thus, the inter-axis distances of the first axis CL1, the second axis CL2, the third axis CL3, and the fourth axis CL4 are appropriately ensured, and the volume of the transaxle 92 in the vertical direction is reduced. Therefore, by configuring the first motor MG1 and the second motor MG2, a surplus space B1 is generated, and an uppermost space B2 is generated in the vertical direction above the second motor MG2. The power control unit 54 is mounted in the upper space B (B1+B2).

[0062] When the power control unit 54 is mounted on the electric vehicle 10, it is arranged above the variable speed drive axle 92 in the vertical direction. Moreover, when the power control unit 54 is mounted on the electric vehicle 10, the vertical lower side portion of the power control unit 54 is arranged at a position overlapping with the variable speed drive axle 92, especially the vertical upper side portion of the second motor MG2 when viewed in the horizontal direction, especially in the forward and backward directions. To put it another way, when the power control unit 54 is mounted on the electric vehicle 10, the vertical lower side portion of the power control unit 54 is arranged above the first motor MG1 in the vertical direction. The vertical lower side portion of the power control unit 54 is, for example, a component (such as the DCDC converter 56 and the reactor) in the power control unit 54 that is accommodated in the remaining space B1.

[0063] The power control unit 54 is mounted in a space created by reducing the volume of the transaxle 92 in the vertical direction, and a space is created above the drive unit 90 in the vertical direction.

[0064] Here, the first motor MG1 and the second motor MG2 are cooled by the oil FLD in the electric vehicle 10. The oil FLD is also used to cool the power control unit 54. The cooling system using the oil FLD will be described in detail below by taking the first motor MG1 as an example.

[0065] Figure 4 It is a diagram for explaining an example of a cooling system using oil FLD. Figure 5 This is a diagram for explaining an example of the structure of the cover 18c of the case 18 in the cooling system using the oil FLD. Figure 4 It is a side view as seen from the left side of electric vehicle 10 . Figure 5 This is a perspective view of electric vehicle 10 as seen from the rear and right side.

[0066] exist Figure 1 , Figure 4 , Figure 5 In the embodiment, the electric vehicle 10 is further equipped with an electric oil pump 74, an oil storage portion 76, a filter 78, an intake oil passage 80, an exhaust oil passage 82, an intermediate oil passage 84, a cooling pipe 86, etc. in the housing 18. The electric vehicle 10 is further equipped with an oil cooler 88 mounted on the housing 18, for example, on the outside of the cover 18c.

[0067] The oil reservoir 76 is an oil tank provided at the bottom of the gear chamber Rg for storing the oil FLD. The electric oil pump 74 is driven based on a command from the electronic control device 70, sucks the oil FLD from the oil reservoir 76 through the filter 78 and the suction oil passage 80, and discharges the oil FLD to the discharge oil passage 82.

[0068] The oil cooler 88 is a heat exchanger or the like that cools the oil FLD by heat exchange. In the oil cooler 88, for example, the oil FLD is cooled by an electric or mechanical cooling fan or the like, or by a refrigerant such as a cooling medium.

[0069] The oil FLD discharged to the discharge oil passage 82 is supplied to the intermediate oil passage 84 via the oil cooler 88. The intermediate oil passage 84 is an oil passage on the downstream side of the oil cooler 88 and an oil passage between the oil cooler 88 and the cooling pipe 86 for introducing the oil FLD into the cooling pipe 86.

[0070] The cooling pipe 86 is a cooling oil passage for spraying the oil FLD discharged from the electric oil pump 74 toward the first electric motor MG1 for cooling the first electric motor MG1. The cooling pipe 86 is an upper pouring pipe arranged above the first electric motor MG1 in the vertical direction. The cooling pipe 86 is arranged along the vehicle width direction. That is, the direction of the cooling pipe 86 is the same as the direction of the first axis CL1. There are upper pouring cooling and axial cooling as cooling of electric motors, and in the electric vehicle 10, at least upper pouring cooling is adopted as cooling of the first electric motor MG1.

[0071] In the drive unit 90 in which the power control unit 54 is arranged vertically above the transaxle 92, the power control unit 54 is arranged adjacent to the first motor MG1 in the vertical direction. In order to reduce the vertical volume of the drive unit 90, it is necessary to shorten the physical distance between the first motor MG1 and the power control unit 54. Therefore, the first motor MG1 and the power control unit 54 are easily heated by each other.

[0072] Here, the cooling pipe 86 is arranged between the first motor MG1 and the power control unit 54. For example, the cooling pipe 86 is arranged between the first motor MG1 and the lower part of the power control unit 54 in the vertical direction (that is, the part accommodated in the remaining space B1). The cooling pipe 86 is provided with a plurality of spray holes that are opened to the first motor MG1 and the power control unit 54, for example, so that the oil FLD is sprayed out from the spray holes. As cooling of the first motor MG1, by spraying the oil FLD from the upper part, the oil FLD can flow down from the upper side in the vertical direction to the lower side in the vertical direction, thereby cooling the entire first motor MG1. By arranging the power control unit 54 on the upper side in the vertical direction of the cooling pipe 86, the number of cooling pipes 86 can be reduced, and cooling can be performed efficiently.

[0073] By disposing the cooling pipe 86 between the first electric motor MG1 and the power control unit 54, both the first electric motor MG1 and the power control unit 54 can be cooled by the oil FLD. This maximizes the cooling efficiency by the oil FLD and minimizes the disposition space of the cooling pipe 86.

[0074] There is heat conduction between the first electric motor MG1 and the electric power control unit 54 via the bus bar 68. If the physical distance between the first electric motor MG1 and the electric power control unit 54 is shortened, the bus bar 68 is shortened. Therefore, the heat dissipation of the bus bar 68 is deteriorated, and the first electric motor MG1 and the electric power control unit 54 are easily heated.

[0075] Here, the cooling pipe 86 is disposed between any two bus bars 68 among the plurality of bus bars 68u, 68v, and 68w. This can cool the heat receiving path between the first electric motor MG1 and the power control unit 54, thereby suppressing heat reception between the first electric motor MG1 and the power control unit 54.

[0076] The bus bar 68 with a short path has poorer heat dissipation than the bus bar 68 with a long path. If the oil FLD is sprayed to the bus bar 68 with a short path, the heat can be efficiently suppressed. Any two bus bars 68 between which the cooling pipe 86 is arranged are, for example, two bus bars 68 with a short path among the plurality of bus bars 68u, 68v, and 68w.

[0077] Figure 6 1 is a diagram for explaining an example of a cooling system in which cooling pipes 86 are arranged between bus bars 68. Figure 6In the figure, the bus bar 68 includes an MG bus bar 68m and a PCU bus bar 68p. The MG bus bar 68m is a plurality of motor-side power lines connected to the first motor MG1 among a plurality of bus bars 68u, 68v, and 68w, including a plurality of MG bus bars 68mu, 68mv, and 68mw. The PCU bus bar 68p is a plurality of power control device-side power lines connected to the power control unit 54 among a plurality of bus bars 68u, 68v, and 68w, including a plurality of PCU bus bars 68pu, 68pv, and 68pw. The electric vehicle 10 is also equipped with a terminal board 94 that connects a plurality of MG bus bars 68mu, 68mv, and 68mw with a plurality of PCU bus bars 68pu, 68pv, and 68pw. The MG bus bar 68mu is connected to the PCU bus bar 68pu at the terminal board 94 by the bus bar 68u. The MG bus bar 68mv and the PCU bus bar 68pv are connected at the terminal board 94 by the bus bar 68v. The MG bus bar 68mw and the PCU bus bar 68pw are connected at the terminal board 94 by the bus bar 68w. Any two bus bars 68 between which the cooling pipe 86 is arranged are any two MG bus bars 68m among the plurality of MG bus bars 68mu, 68mv, and 68mw arranged between the first motor MG1 and the terminal board 94. That is, the cooling pipe 86 is arranged between any two MG bus bars 68m among the plurality of MG bus bars 68mu, 68mv, and 68mw. These any two MG bus bars 68m are, for example, two MG bus bars 68mv and 68mw having the shortest path among the plurality of MG bus bars 68mu, 68mv, and 68mw.

[0078] As described above, according to the present embodiment, the cooling pipe 86 is disposed between the first electric motor MG1 and the electric power control unit 54. As a result, both the first electric motor MG1 and the electric power control unit 54 are cooled by the oil FLD ejected from the cooling pipe 86, and the heat generation of the first electric motor MG1 and the electric power control unit 54 can be suppressed. Therefore, the cooling performance of the first electric motor MG1 and the electric power control unit 54 can be improved.

[0079] According to the present embodiment, the cooling pipe 86 is disposed between any two bus bars 68 among the plurality of bus bars 68u, 68v, 68w. Thus, the bus bars 68 are cooled by the oil FLD ejected from the cooling pipe 86, and the heat transfer between the first electric motor MG1 and the power control unit 54 can be suppressed.

[0080] In addition, according to the present embodiment, the two bus bars 68 are two bus bars 68 with short paths among the plurality of bus bars 68u, 68v, and 68w. Therefore, the heat dissipation is poorer than that of the bus bars 68 with long paths, and the bus bars 68 with short paths are cooled, so that the heat received by the first motor MG1 and the power control unit 54 can be efficiently suppressed.

[0081] In addition, according to the present embodiment, the two bus bars 68 are any two MG bus bars 68m among the plurality of MG bus bars 68mu, 68mv, and 68mw disposed between the first electric motor MG1 and the terminal plate 94. Thus, the power lines are cooled by the oil ejected from the cooling oil passage, and the heat received by the first electric motor MG1 and the electric power control unit 54 can be appropriately suppressed.

[0082] In addition, according to the present embodiment, the cooling pipe 86 is disposed between the first electric motor MG1 and the vertically lower portion of the electric power control unit 54. Therefore, both the first electric motor MG1 and the vertically lower portion of the electric power control unit 54 are cooled by the oil FLD ejected from the cooling pipe 86, and the heat generation of the first electric motor MG1 and the electric power control unit 54 can be suppressed.

[0083] In addition, according to the present embodiment, the direction of the cooling pipe 86 is the same as the direction of the first axis CL1, that is, the vehicle width direction. As a result, the cooling oil FLD can flow down from the upper side in the vertical direction to the lower side in the vertical direction over the entire length of the first electric motor MG1 in the vehicle width direction, and the entire first electric motor MG1 can be efficiently cooled.

[0084] As mentioned above, although the embodiment of the present invention is described in detail based on the drawings, the present invention is also applicable to other aspects.

[0085] For example, in the above-described embodiment, the second motor MG2 may be cooled by pouring cooling similar to the first motor MG1. The present invention may also be applied to the second motor MG2. As long as the cooling pipe is arranged between the motors (MG1, MG2) and the power control unit 54, a certain effect of the present invention can be obtained. Figure 7 FIG. 1 is a diagram showing an example of the mounting range of the cooling pipe. Figure 7 In the figure, the cooling pipe only needs to be arranged between the thick line C and the thick line D.

[0086] Furthermore, in the above-described embodiment, the transaxle 92 and the power control unit 54 are housed in separate spaces partitioned by partition walls within the housing 18 . However, they may be housed in the same space not partitioned by partition walls.

[0087] In the above-described embodiment, as the oil pump for discharging the oil FLD, a mechanical oil pump may be used in place of the electric oil pump 74 , or a mechanical oil pump may be used in addition to the electric oil pump 74 .

[0088] In addition, in the above-mentioned embodiments, Figure 8 As shown, the electric vehicle may also be an electric car 100 equipped with a driving motor MG. Figure 8The electric vehicle 100 is different from the electric vehicle 10 of the above-described embodiment mainly in that the electric vehicle 100 is not equipped with the structural components (engine 12, transmission unit 24 including first electric motor MG1) around the first axis CL1. In addition, the electric motor MG of the electric vehicle 100 is equivalent to the second electric motor MG2 of the electric vehicle 10. In the electric vehicle 100, for example, Figure 3 In the arrangement positions of the structural members of the transaxle 92 shown, the first electric motor MG1 is eliminated and the second electric motor MG2 functions as the electric motor MG.

[0089] In addition, in the above-mentioned embodiment, the electric vehicle may also be a series hybrid vehicle equipped with an engine, a driving motor that functions as a power source, and an electric motor for power supply that can be connected to the engine in a power transmission manner and generates electricity via the power of the engine. In such a series hybrid vehicle, a structure that disconnects or connects the power transmission path between the engine and the drive wheel by the action of a clutch may also be used. In addition, the electric vehicle may also be a parallel hybrid vehicle equipped with an engine, a power transmission device that transmits power from the engine to the drive wheel, and an electric motor that transmits power to the drive wheel via the power transmission device.

[0090] In addition, in the above-described embodiment, the first motor MG1, the second motor MG2, and the motor MG are not limited to three-phase AC synchronous motors. For example, the first motor MG1, the second motor MG2, and the motor MG may be other motors such as single-phase synchronous motors or induction motors. The power line electrically connecting the motor and the power control device can be any power line through which current that drives the motor flows.

[0091] Furthermore, what has been described above is merely one embodiment, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art.

[0092] Description of Reference Numerals

[0093] 10: Electric vehicle, 16: Power transmission device, 18: Housing, 50: High-voltage battery (driving battery), 54: Power control unit (power control device), 62: Inverter, 64: MG1 power module (three-phase bridge circuit), 66: MG2 power module (three-phase bridge circuit), 68 (68u, 68v, 68w): Bus (power line), 68m (68mu, 68mv, 68mw): MG bus (motor side power line), 68p (68pu, 68pv, 68pw): PCU bus (power control device side power line), 74: Electric oil pump ( oil pump), 86: cooling pipe (cooling oil circuit), 90: drive unit (mechatronic unit), 92: variable speed drive axle (drive device), 94: terminal board, CL1: first axis (rotation axis of the first motor), CL2: second axis (rotation axis of the power transmission device), CL3: third axis (rotation axis of the second motor), CL4: fourth axis (rotation axis of the power transmission device), FLD: oil, MG1: first motor (motor, synchronous motor), MG2: second motor (motor, synchronous motor), 100: electric vehicle (electric vehicle), MG: motor

Claims

1. An electric vehicle (10; 100), comprising: an electric motor (MG1, MG2; MG); a power transmission device (16), the power transmission device (16) being connected to the electric motor (MG1, MG2; MG) so as to be capable of transmitting power; a battery (50) for driving; a power control device (54), the power control device (54) controlling the power transferred between the battery (50) and the electric motor (MG1, MG2; MG); and a housing (18), the housing (18) housing the electric motor The electric motor (MG1, MG2; MG) and the drive device (92) of the power transmission device (16) and the power control device (54) are used as a mechatronic unit (90); an oil pump (74) that discharges oil (FLD); and a cooling oil circuit (86) that uses the oil (FLD) for cooling the electric motor (MG1, MG2; MG) and sprays it to the electric motor (MG1, MG2; MG), wherein the electric vehicle (10; 100) is characterized in that: The power control device (54) is arranged adjacent to the motor (MG1, MG2; MG) in the vertical direction above the motor (MG1, MG2; MG) when mounted on the electric vehicle (10; 100). The cooling oil passage (86) is arranged between the electric motor (MG1, MG2; MG) and the electric power control device (54).

2. The electric vehicle (10; 100) according to claim 1, characterized in that A plurality of power lines (68) are also provided for electrically connecting the electric motors (MG1, MG2; MG) and the power control device (54). The cooling oil passage (86) is arranged between any two of the plurality of power lines (68).

3. The electric vehicle (10; 100) according to claim 2, characterized in that The any two power lines (68) are two power lines (68) having a short path among the plurality of power lines (68).

4. The electric vehicle (10; 100) according to claim 2, characterized in that The power control device (54) is equipped with an inverter (62), and the inverter (62) has a three-phase bridge circuit (64, 66) of U phase, V phase, and W phase. The motor (MG1, MG2; MG) is a three-phase AC synchronous motor (MG1, MG2; MG) driven by the inverter (62), The plurality of power lines (68) are three power lines (68) through which three-phase alternating currents of U phase, V phase and W phase flow.

5. The electric vehicle (10; 100) according to claim 4, characterized in that The any two power lines (68) are two power lines (68) having a short path among the three power lines (68).

6. The electric vehicle (10; 100) according to claim 2, characterized in that A terminal board (94) is also provided, wherein the terminal board (94) connects a plurality of motor-side power lines (68m) connected to the motors (MG1, MG2; MG) among the plurality of power lines (68) and a plurality of power control device-side power lines (68p) connected to the power control device (54) among the plurality of power lines (68), The two power lines (68) are any two motor side power lines (68m) among the plurality of motor side power lines (68m) arranged between the motor (MG1, MG2; MG) and the terminal board (94).

7. The electric vehicle (10) according to any one of claims 1 to 6, characterized in that: The electric motors (MG1, MG2) include a first electric motor (MG1) and a second electric motor (MG2), When the drive device (92) is mounted on the electric vehicle (10), the rotation axis (CL1) of the first motor (MG1), the rotation axis (CL3) of the second motor (MG2), and the rotation axes (CL2, CL4) of the power transmission device (16) are respectively arranged in parallel with a horizontal direction perpendicular to the forward and backward direction of the electric vehicle (10), and are arranged in the order of the rotation axis (CL3) of the second motor (MG2) and the rotation axis (CL1) of the first motor (MG1) from top to bottom in the vertical direction. When the power control device (54) is mounted on the electric vehicle (10), the vertical lower portion is arranged at a position overlapping with the vertical upper portion of the second motor (MG2) when viewed in the forward and backward direction, and the vertical lower portion is arranged above the first motor (MG1) in the vertical direction. The cooling oil passage (86) is arranged between the first electric motor (MG1) and the vertically lower portion of the power control device (54).

8. The electric vehicle (10; 100) according to claim 1, characterized in that The direction of the cooling oil passage (86) is the same as the direction of the rotation axis of the electric motor (MG1, MG2; MG).

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