Drive unit mounting structure

Abstract

The present invention is a vehicle-mounted structure for mounting, in a vehicle provided with an engine, a driving unit comprising a driving motor and a transmission, wherein the driving unit is configured by coupling the driving motor and the transmission in series in the width direction of the vehicle, an exhaust pipe of the engine extends so as to pass through the vicinity of the transmission in the front-back direction of the vehicle, and the transmission comprises, at a position facing the exhaust pipe, a cooling water flow path through which flows cooling water for cooling a lubricant for lubricating a speed change mechanism inside the transmission.

Description

[Technical field]

[0001] The present invention relates to a mounting structure for a drive unit of a vehicle equipped with an engine. [Background technology]

[0002] In a hybrid vehicle equipped with an engine and a rotating electric machine (motor), the exhaust pipe through which the engine exhaust passes may be located adjacent to the motor due to the layout of the vehicle. In such a location, the heat of the exhaust pipe, which becomes very hot, is transferred to the motor, causing the motor temperature to rise and reducing its efficiency.

[0003] JP2009-269547A discloses a configuration in which an insulator is provided between the motor and the exhaust pipe, and air is blown between the motor and the exhaust pipe from a blower fan, thereby preventing hot air from accumulating near the motor. Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned patent documents, since parts such as an insulator and a blower are newly installed in the vehicle in order to cool the motor, there is a problem that the cost of parts and the number of assembly steps increase.

[0005] The present invention has been made in consideration of such problems, and has an object to provide a vehicle mounting structure for a drive unit that is configured so as not to transfer heat from the exhaust pipe to the motor without increasing costs. [Means for solving the problem]

[0006] According to one embodiment of the present invention, the present invention is applied to a vehicle mounting structure in which a drive unit consisting of a drive motor and a transmission is mounted on a vehicle equipped with an engine. The drive unit is configured by connecting the drive motor and the transmission in series in the width direction of the vehicle. The exhaust pipe of the engine is extended so as to pass near the transmission in the front-rear direction of the vehicle. The transmission is provided with a cooling water flow path at a position opposite the exhaust pipe, through which cooling water flows to cool the lubricating oil that lubricates the speed change mechanism in the transmission. Effect of the Invention

[0007] According to the present invention, a transmission is interposed between the drive motor and the exhaust pipe, and a cooling water flow path is provided in a position of the transmission facing the exhaust pipe, so that heat from the exhaust pipe is prevented from being directly transmitted to the motor. This makes it possible to suppress the temperature rise of the drive motor and prevent a decrease in the efficiency of the drive motor without adding new parts such as a blower. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of a drive unit according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram of the drive unit. [Diagram 3] FIG. 3 is an explanatory diagram of a vehicle mounting structure of the drive unit. [Figure 4] FIG. 4 is an explanatory diagram of a vehicle mounting structure of the drive unit. [Diagram 5] FIG. 5 is a side view of the reducer. [Figure 6] FIG. 6 is a cross-sectional view of the drive unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] FIG. 1 is a configuration diagram of a hybrid vehicle 100 equipped with a drive unit 1 according to an embodiment of the present invention.

[0011] A hybrid vehicle (hereinafter also referred to as “vehicle”) 100 includes a drive unit 1, a battery 40, an engine 50, a generator 60, an axle 71, and drive wheels 72. The drive unit 1 includes a drive motor (rotating electric machine) 10, a reduction gear (transmission) 20, and a power conversion device 30.

[0012] The traction motor 10 is driven by receiving a supply of electric power from the power conversion device 30, and rotates the drive wheels 72 to drive the vehicle 100. The traction motor 10 also functions as a generator that generates regenerative electric power when the vehicle 100 decelerates.

[0013] The reducer 20 is a transmission having multiple gears, which reduces the rotation speed of the drive motor 10 and rotates the drive wheels 72 via an axle 71. The reducer 20 is disposed in series with the drive motor 10, and rotates the axle 71 which passes through the reducer 20 and the drive motor 10.

[0014] The power conversion device 30 is configured with an inverter unit, and converts the power charged in the battery 40 into power appropriate for driving the drive motor 10 and supplies it to the drive motor 10. The power conversion device 30 receives power generated by the generator 60 and regenerative power from the drive motor 10 to charge the battery 40.

[0015] When the SOC of the battery 40 drops, the power conversion device 30 starts the engine 50 and generates power by having the engine 50 drive the generator 60. The power generated by the generator 60 is supplied to the drive motor 10 via the power conversion device 30 and charges the battery 40.

[0016] In the vehicle 100 of this embodiment, the drive unit 1 is provided at the rear side of the vehicle 100 to drive the rear wheels 72. Note that a separate motor for driving the front wheels may be provided at the front side of the vehicle 100 (for example, in an engine room), or the engine 50 may be configured to drive the front wheels.

[0017] Fig. 2 is an explanatory diagram of the drive unit 1. Fig. 3 is an explanatory diagram of a vehicle-mounted structure of the drive unit 1 according to an embodiment of the present invention, showing the drive unit 1 and suspension member 2 observed from below the vehicle 100.

[0018] As shown in Fig. 2, the drive unit 1 is configured by connecting a drive motor 10 and a reduction gear 20 in the width direction of the vehicle 100. left A drive motor 10 is disposed in the Right side A reduction gear 20 is disposed on the drive motor 10, and a power conversion device 30 is mounted on the upper part of the drive motor 10. Axles 71 are provided extending outward in the width direction of the vehicle 100 from both ends of the drive motor 10 and the reduction gear 20.

[0019] The drive shaft of the drive motor 10 has a hollow structure, and one end of the drive shaft is connected to the input side of the reduction mechanism (speed change mechanism) 22 (see FIG. 6) of the reduction gear 20. The rotation reduced by the reduction mechanism 22 passes through the inside of the hollow shaft via an axle 71 connected to the output side of the reduction mechanism 22, protruding from both ends of the drive motor 10 and the reduction gear 20, and is connected to drive wheels 72.

[0020] As shown in FIG. 3, the drive unit 1 is supported by a suspension member 2 and mounted on a vehicle 100.

[0021] The suspension member 2 is composed of a set of side members 81 extending in the front-rear direction of the vehicle 100, and a set of cross members 82 extending in the width direction of the vehicle 100. A substantially rectangular shape is defined by the set of side members 81 and the set of cross members 82. The drive unit 1 is fixed to the side members 81 and the cross members 82 via mounts such as bushes so that the drive unit 1 is located inside the rectangular shape of the suspension member 2.

[0022] An exhaust pipe 51 extends from the engine 50. The exhaust pipe 51 extends from the engine 50 toward a muffler 52 disposed on the rear side of the vehicle 100, and is disposed below the vehicle 100.

[0023] In the vicinity of the suspension member 2, the exhaust pipe 51 is disposed so as to pass below the suspension member 2 (on the front side in FIG. 3) across the front-rear direction of the vehicle 100.

[0024] Conventionally, when the drive unit 1 is disposed at the rear of the vehicle 100, the following problems arise.

[0025] The exhaust pipe 51 has a high surface temperature (e.g., 200° C.) because the exhaust pipe 51 passes through it and is subjected to high temperatures. However, the efficiency of the drive motor 10 and the power conversion device 30 decreases when exposed to such high temperatures. Therefore, it is desirable to arrange them not to be close to the exhaust pipe 51.

[0026] However, in the rear of the vehicle 100 where the suspension member 2 is arranged, in addition to the drive unit 1, suspension member 2, and muffler 52, a suspension device (not shown) and the like are also arranged. Therefore, in the rear of the vehicle 100, restrictions are imposed on the arrangement of the exhaust pipe 51, and it may not be possible to ensure a sufficient distance between the drive unit 1 and the exhaust pipe 51.

[0027] In this case, components such as an insulator or a blower can be provided to prevent heat from being transmitted from the exhaust pipe 51 to the drive motor 10. However, such a configuration increases the number of components and assembly steps, resulting in increased costs.

[0028] Therefore, in this embodiment, as described below, a configuration is made in which the heat of the exhaust pipe 51 is not transferred to the drive motor 10 without increasing the number of parts.

[0029] As shown in FIG. 3, the exhaust pipe 51 extends from the engine 50 to the rear of the vehicle 100 and is disposed near the suspension member 2 as shown in FIG. Rightward The exhaust pipe 51 is bent toward the front cross member 82 (the reduction gear 20 side of the drive unit 1). Right side The side member 81 is curved toward the rear of the vehicle 100 near the intersection with the side member 81. Right side Along the side member 81 of Right sideThe exhaust pipe 51 is disposed so as to pass directly below the side member 81. The exhaust pipe 51 then passes through a rear cross member 82 and is connected to a muffler 52 that is disposed rearward of the suspension member 2 in the vehicle.

[0030] In this way, the exhaust pipe 51 is disposed near the lower portion of the suspension member 2. Right side Side member 81 and Front It is extended below the cross member 82 in a shape that fits along these.

[0031] FIG. 4 is an explanatory diagram of the drive unit 1 and the suspension member 2 viewed from diagonally rearward of the vehicle 100, and shows the direction of arrow M in FIG.

[0032] 4, the exhaust pipe 51 is configured to run along the side member 81 and the cross member 82 below the suspension member 2. By arranging the exhaust pipe 51 near the suspension member 2 in this manner, the side member 81 is interposed between the exhaust pipe 51 and the reduction gear 20 near the drive unit 1.

[0033] The suspension member 2 is made of a metal with a large heat capacity, such as iron. Therefore, the heat transferred from the exhaust pipe 51 to the suspension member 2 is diffused to each part of the suspension member 2 and is quickly dissipated by the wind generated when the vehicle is running.

[0034] With this configuration, the heat of the exhaust pipe 51 is blocked by the side member 81 and is less likely to be transmitted to the drive unit 1 side.

[0035] In the drive unit 1, the drive motor 10 is disposed on the side farther from the exhaust pipe 51 than the reduction gear 20 (the left side in FIG. 4). In other words, when viewed from the drive motor 10, the reduction gear 20 and the side member 81 are present between the drive motor 10 and the exhaust pipe 51.

[0036] With this configuration, the heat of the exhaust pipe 51 is blocked by the side member 81 and the reduction gear 20, and is prevented from being directly transmitted to the drive motor 10 and the power conversion device 30.

[0037] Furthermore, the reducer 20 includes a cooling water passage 211, as will be described next.

[0038] Fig. 5 is an explanatory diagram of the reducer 20 as viewed from the axial direction (arrow A in Fig. 2). Fig. 6 is a cross-sectional view of the drive unit 1 and the suspension member 2, taken along line VI-VI in Fig. 3.

[0039] The speed reducer 20 is configured by accommodating a speed reduction mechanism 22 (see FIG. 6) made up of a plurality of gears (for example, a planetary gear mechanism) in a housing 21 having a substantially cylindrical outer diameter.

[0040] The housing 21 is made of a metal such as an aluminum alloy and has a cylindrical shape, and includes a cooling water flow path 211 (shown by a dotted line in FIG. 5) inside thereof through which a refrigerant (cooling water) flows. The cooling water flow path 211 is formed as an arc-shaped space facing the lower part of the reduction mechanism 22 in a case where the housing 21 is cut along a plane perpendicular to the rotational axis direction. This arc-shaped space is formed as a passage extending in the front-rear direction of the vehicle, and is configured to cover the lower side of the reduction mechanism 22 (shown by a dashed line in FIG. 5) housed in the housing 21.

[0041] A coolant inlet 212 and a coolant outlet 213 that allow coolant to flow through the coolant flow passage 211 are provided on an end face 21A of the housing 21 (the end in the axial direction opposite to the drive motor 10). The coolant inlet 212 and the coolant outlet 213 are disposed apart from each other in the front-rear direction of the vehicle 100 on the end face 21A of the reducer 20.

[0042] That is, the cooling water inlet 212 is disposed on the rear side of the vehicle 100 in the reduction gear 20, and communicates with one end of the cooling water flow path 211 formed in an arc shape. The cooling water outlet 213 is disposed on the front side of the vehicle 100 in the reduction gear 20, and communicates with the other upper end of the cooling water flow path 211 formed in an arc shape. The cooling water inlet 212 is disposed at a position higher above the road surface than the cooling water outlet 213.

[0043] Lubricating oil for lubricating the reduction gear mechanism 22 is stored inside the housing 21. The lubricating oil comes into contact with a cooling water passage 211 formed in the housing 21 via the inner surface of the housing 21, and is cooled by the cooling water in the cooling water passage 211.

[0044] As shown in FIG. 6, the cooling water passage 211 of the reducer 20 is formed at a position facing the exhaust pipe 51 arranged near the lower part of the reducer 20.

[0045] Although some of the heat from the exhaust pipe 51 passes through the side member 81 and is transferred to the lower part of the end face 21A side of the housing 21 of the reducer 20, the presence of a cooling water flow path 211 in the housing 21 prevents the heat transferred to the housing 21 from being transferred to the drive motor 10 or the power conversion device 30.

[0046] In this embodiment, there are some locations between the exhaust pipe 51 and the reduction gear 20 where the suspension members 2 (side members 81, cross members 82) are not necessarily present. Even in such locations, the presence of the cooling water flow paths 211 of the reduction gear 20 prevents the heat of the exhaust pipe 51 from being transmitted to the drive motor 10.

[0047] In the reducer 20, the cooling water inlet 212 is disposed at a position where its height from the road surface is higher than the height from the road surface of the cooling water outlet 213. The cooling water flow path 211 formed in an arc shape at the bottom of the housing 21 is configured to cover the lubricating oil stored in the reducer 20 from below.

[0048] This configuration can improve the cooling efficiency of the reduction gear 20 on an uphill road. Specifically, when the vehicle 100 is climbing an uphill road, the oil level of the lubricating oil in the reduction gear 20 (indicated by the dashed line in FIG. 5) inclines according to the inclination of the uphill road, and the oil level on the rear side of the vehicle becomes higher than the front side of the vehicle. Furthermore, when the vehicle 100 is climbing an uphill road, the torque required by the drive motor 10 and the engine 50 increases compared to when the vehicle is climbing a flat road or descending a slope. Therefore, in such a case, the temperature of the exhaust pipe 51 increases.

[0049] 5, since the vehicle rear side (cooling water inlet 212) of the cooling water flow passage 211 is located at a high position, even if the oil level of the lubricating oil tilts rearward, the cooling water inlet 212 is located above the tilted oil level of the lubricating oil. As a result, almost the entire stored lubricating oil is cooled by the cooling water.

[0050] Therefore, even when the vehicle 100 is climbing an uphill road, the cooling efficiency of the reduction gear 20 is not impaired. Furthermore, since the cooling water in the cooling water passage 211 quickly dissipates the heat transferred from the exhaust pipe 51, the heat of the exhaust pipe 51 is not transferred to the drive motor 10.

[0051] Furthermore, as shown in FIG. 3, near the cooling water inlet 212 arranged in the housing 21 of the reducer 20, the exhaust pipe 51 is configured such that, in a plan view, its center (center line P) is aligned with the widthwise center (center line F) of the side member 81 or is positioned outside the widthwise center (on the side away from the reducer 20).

[0052] The heat of the exhaust pipe 51 is blocked by the side member 81 and is difficult to transmit to the reduction gear 20, particularly to the cooling water inlet 212. The cooling water flowing in from the cooling water inlet 212 has not yet undergone heat exchange inside the reduction gear 20, and is therefore at a lower temperature than the cooling water flowing out from the cooling water outlet 213. Therefore, by configuring the vicinity of the cooling water inlet 212 so that heat is not transmitted from the exhaust pipe 51, it is possible to prevent the cooling efficiency of the reduction gear 20 from being impaired.

[0053] The embodiment of the present invention described above is applied to an on-board structure in which a drive unit 1 consisting of a drive motor 10 and a transmission (reduction gear 20) is mounted on a vehicle 100 equipped with an engine 50. The drive unit 1 is configured by connecting the drive motor 10 and the reduction gear 20 in series in the width direction of the vehicle 100. An exhaust pipe 51 of the engine 50 is extended so as to pass near the reduction gear 20 in the front-rear direction of the vehicle 100. The reduction gear 20 is provided at a position opposite the exhaust pipe 51 with a cooling water flow path 211 through which cooling water flows for cooling the lubricating oil that lubricates the reduction mechanism 22 in the reduction gear 20.

[0054] With this configuration, the heat of the exhaust pipe 51 is not directly transmitted to the drive motor 10, and the heat transmitted to the reduction gear 20 is quickly removed by the cooling water. As a result, the drive motor 10 is not affected by the heat of the exhaust pipe 51, and it is possible to prevent a decrease in the efficiency of the drive motor 10 without adding new parts such as a heat shield. The drive motor 10 and the power conversion device 30 also have housings, and are each provided with a cooling water flow path through which cooling water flows.

[0055] In addition, in this embodiment, the reducer 20 has a housing 21 that accommodates the reduction mechanism 22, and a cooling water flow path 211 is formed in the housing 21. The cooling water flow path 211 is formed in an arc shape on the lower side of the housing 21 in the fore-and-aft direction of the vehicle.

[0056] With this configuration, the lubricating oil is always cooled by the cooling water on the inner circumferential side of the cooling water flow passage 211 formed in an arc shape, so that the cooling efficiency of the reducer 20 is not impaired.

[0057] In addition, in this embodiment, the housing 21 has the cooling water inlet 212 and the cooling water outlet 213 of the cooling water flow path 211 arranged apart in the fore-and-aft direction of the vehicle 100, and one of the cooling water inlet 212 and the cooling water outlet 213 is arranged at a higher height from the ground than the other.

[0058] With this configuration, even if the oil level of the lubricating oil tilts inside the reducer 20 when the vehicle 100 travels uphill, the cooling water flows above the tilted oil level of the lubricating oil, so the cooling efficiency of the reducer 20 is not impaired.

[0059] In this embodiment, the cooling water inlet 212 is disposed further rearward of the vehicle 100 than the cooling water outlet 213, and the cooling water inlet 212 is disposed at a position higher above ground level than the cooling water outlet 213.

[0060] With this configuration, even if the lubricating oil level tilts backward inside the reducer 20 when the vehicle 100 is climbing an uphill road, the cooling water inlet 212 is located above the tilted lubricating oil level, allowing the cooling water to flow, so the cooling efficiency of the reducer 20 is not impaired even when climbing an uphill road.

[0061] In the present embodiment, the drive unit 1 has the power conversion device 30 that supplies power to the drive motor 10 disposed above the drive motor 10.

[0062] With this configuration, the heat of the exhaust pipe 51 is not directly transferred to the power conversion device 30, and the power conversion device 30 is not affected by the heat of the exhaust pipe 51, so that it is possible to prevent a decrease in the efficiency of the power conversion device 30 without adding any components.

[0063] In this embodiment, the drive unit 1 is supported by a suspension member 2. The suspension member 2 is made up of a set of side members 81 extending in the front-rear direction of the vehicle 100 and a set of cross members 82 extending in the width direction of the vehicle 100, and the drive unit 1 is disposed inside a substantially rectangular shape defined by the set of side members 81 and the set of cross members 82. The exhaust pipe 51 is disposed below and along the side members 81.

[0064] With this configuration, the heat of the exhaust pipe 51 is blocked by the side member 81 and is less likely to be transmitted to the drive unit 1 side, so that a decrease in the efficiency of the drive motor 10 can be prevented without adding any parts.

[0065] In this embodiment, the exhaust pipe 51 is disposed near the cooling water inlet 212 of the reduction gear 20, below the side member 81, and outside the center of the side member 81 in the width direction of the vehicle 100.

[0066] With this configuration, the heat of the exhaust pipe 51 is blocked by the side member 81 at the cooling water inlet 212 through which the cooling water with the lowest temperature flows into the reduction gear 20, so that the cooling efficiency of the reduction gear 20 is not impaired.

[0067] The above describes the embodiments of the present invention and their modifications. However, the above embodiments and modifications merely illustrate some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0068] The traction motor 10 of this embodiment may be used as a driving power source mounted on devices other than automobiles, for example, various electric devices or industrial machines.

[0069] In addition, in this embodiment, the cooling water inlet 212 is arranged on the rear side of the vehicle 100 in the reduction gear 20, but this is not limited to this, and the cooling water outlet 213 may be arranged on the rear side of the vehicle 100, and the cooling water may be configured to flow from the front side of the vehicle to the rear side of the vehicle in the reduction gear 20.

[0070] In addition, in this embodiment, the reducer 20 may be configured as a transmission having a speed change mechanism capable of switching between a plurality of reduction stages.

[0071] In addition, in this embodiment, the suspension member 2 (side member 81) is configured to be interposed between the exhaust pipe 51 and the reduction gear 20, but this is not limited to the above. There may be no suspension member 2 between the exhaust pipe 51 and the drive motor 10 and the power conversion device 30, and only the reduction gear 20 may be interposed. The cooling water passage 211 of the reduction gear 20 prevents heat from the exhaust pipe 51 from being transferred to the drive motor 10 and the power conversion device 30. In this case, the exhaust pipe 51 may be disposed near the side surface of the housing 21 where the cooling water passage 211 is present, rather than below the reduction gear 20.

Claims

1. A vehicle mounting structure in which a drive unit including a drive motor and a transmission is mounted on a vehicle having an engine, The drive unit is configured by connecting the drive motor and the transmission in series in a width direction of the vehicle, an exhaust pipe of the engine extends in a front-rear direction of the vehicle so as to pass near the transmission; The transmission includes a cooling water flow path through which cooling water for cooling a lubricating oil that lubricates a transmission mechanism in the transmission flows, the cooling water flow path being located opposite the exhaust pipe. Vehicle mounting structure of drive unit.

2. 2. The vehicle mounting structure of the drive unit according to claim 1, The transmission includes a housing that accommodates the transmission mechanism, The housing has the cooling water passage formed therein. The cooling water flow path is formed in an arc shape on the lower side of the housing so as to face a lower portion of the transmission mechanism. Vehicle mounting structure of drive unit.

3. 3. The vehicle mounting structure of the drive unit according to claim 2, the cooling water outlet is disposed rearward of the vehicle relative to the cooling water inlet, The cooling water outlet is disposed at a position higher from the road surface than the cooling water inlet. Vehicle mounting structure of drive unit.

4. A vehicle mounting structure for the drive unit according to claim 2, the cooling water inlet is disposed rearward of the vehicle relative to the cooling water outlet, The cooling water inlet is disposed at a position higher from the road surface than the cooling water outlet. Vehicle mounting structure of drive unit.

5. A vehicle mounting structure for a drive unit according to any one of claims 1 to 4, The drive unit includes a power conversion device that supplies power to the drive motor and is mounted on an upper portion of the drive motor. Vehicle mounting structure of drive unit.

6. 6. A vehicle mounting structure for a drive unit according to claim 1, The drive unit is supported by a suspension member. The suspension member is composed of a pair of side members extending in the front-rear direction of the vehicle and a pair of cross members extending in the width direction of the vehicle, the drive unit is disposed inside a substantially rectangular shape defined by a set of the side members and a set of the cross members, The exhaust pipe is disposed below the side member and along the side member. Vehicle mounting structure of drive unit.

7. 7. The vehicle mounting structure of a drive unit according to claim 6, 1. The exhaust pipe is disposed near the cooling water inlet of the transmission, below the side member, and outboard of the center of the side member in the vehicle width direction. Vehicle mounting structure of drive unit.

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