Vehicle-mounted configuration of drive unit

Abstract

A vehicle-mounted structure mounts a drive unit composed of a drive motor and a transmission on a vehicle having an engine, the drive unit being composed of the drive motor and the transmission connected in series in a width direction of the vehicle, an exhaust pipe of the engine being disposed so as to extend in a front-rear direction of the vehicle in the vicinity of the transmission, the transmission having a cooling water flow path for cooling water to flow at a position opposite the exhaust pipe, the cooling water cooling lubricating oil for lubricating a transmission mechanism in the transmission.

Description

Technical Field

[0001] This invention relates to an onboard structure for a drive unit of a vehicle having an engine. Background Technology

[0002] Regarding hybrid vehicles equipped with an engine and a rotating electric motor (electric motor), depending on the vehicle layout, the exhaust pipe through which the engine's exhaust flows is sometimes configured adjacent to the electric motor. In this configuration, the heat from the hot exhaust pipe is conducted to the electric motor, increasing its temperature and reducing its efficiency.

[0003] JP2009-269547A discloses a structure in which an isolation element is provided between the motor and the exhaust pipe, and air is supplied from the exhaust fan between the motor and the exhaust pipe, so that hot air does not linger near the motor. Summary of the Invention

[0004] In the aforementioned patent documents, in order to cool the motor, new components such as isolation components and blowers are installed in the vehicle, which leads to increased component costs and assembly time.

[0005] The present invention was made in view of this problem, and its object is to provide an on-vehicle structure for a drive unit that is configured to conduct heat from the exhaust pipe to the motor without increasing costs.

[0006] According to one embodiment of the present invention, a vehicle-mounted structure is applied to a vehicle having an engine, which mounts a drive unit consisting of a drive motor and a transmission. The drive unit is configured by connecting the drive motor and the transmission in series in the width direction of the vehicle. The engine's exhaust pipe extends near the transmission, passing through the vehicle's longitudinal direction. The transmission has a cooling water flow path opposite the exhaust pipe, through which cooling water cools the lubricating oil that lubricates the transmission mechanism within the transmission.

[0007] The effects of the invention

[0008] According to the present invention, the transmission is located between the drive motor and the exhaust pipe, and a cooling water flow path is provided in the transmission opposite to the exhaust pipe, thereby preventing the immediate conduction of heat from the exhaust pipe to the motor. Thus, without adding new components such as a blower, the temperature rise of the drive motor can be suppressed, and the efficiency reduction of the drive motor can be prevented. Attached Figure Description

[0009] Figure 1 This is a block diagram of the driving unit according to an embodiment of the present invention.

[0010] Figure 2 This is an explanatory diagram of the drive unit.

[0011] Figure 3 This is an explanatory diagram of the vehicle-mounted structure of the drive unit.

[0012] Figure 4 This is an explanatory diagram of the vehicle-mounted structure of the drive unit.

[0013] Figure 5 This is a side view of the speed reducer.

[0014] Figure 6 This is a cross-sectional view of the drive unit. Detailed Implementation

[0015] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings and other figures.

[0016] Figure 1 This is a structural diagram of a hybrid vehicle 100 equipped with a drive unit 1 according to an embodiment of the present invention.

[0017] The hybrid vehicle (hereinafter also referred to as "vehicle") 100 has a drive unit 1, a battery 40, an engine 50, a generator 60, an axle 71, and drive wheels 72. The drive unit 1 has a drive motor (rotary motor) 10, a reduction gear (transmission) 20, and a power conversion device 30.

[0018] The drive motor 10 receives power from the power conversion device 30 and is driven to rotate the drive wheel 72, thereby driving the vehicle 100. The drive motor 10 also functions as a generator to generate regenerative electricity when the vehicle 100 decelerates.

[0019] The reducer 20 is a speed-changing device with multiple gears that reduces the rotation of the drive motor 10 and causes the drive wheel 72 to rotate via the axle 71. The reducer 20 and the drive motor 10 are connected in series, so that the axle 71 through which the reducer 20 and the drive motor 10 pass can rotate.

[0020] The power conversion device 30 is configured to have an inverter unit that converts the power used to charge the battery 40 into power suitable 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 regenerated power from the drive motor 10 to charge the battery 40.

[0021] When the SOC of the battery 40 decreases, the power conversion device 30 starts the engine 50, which drives the generator 60 to generate electricity. The electricity generated by the generator 60 is then supplied to the drive motor 10 or used to charge the battery 40 via the power conversion device 30.

[0022] In this embodiment, the vehicle 100 has a drive unit 1 at its rear side to drive the drive wheels 72, which are the rear wheels. Alternatively, a motor for driving the front wheels may be located at the front side of the vehicle 100 (e.g., in the engine compartment), or the engine 50 may drive the front wheels.

[0023] Figure 2 This is an explanatory diagram of drive unit 1. Figure 3 This is an explanatory diagram of the vehicle-mounted structure of the drive unit 1 according to an embodiment of the present invention, showing a view of the drive unit 1 and the suspension beam 2 from below the vehicle 100.

[0024] like Figure 2 As shown, the drive unit 1 is configured by connecting a drive motor 10 and a reducer 20 in the width direction of the vehicle 100. Figure 2 In the vehicle 100, a drive motor 10 is arranged on the left side and a reducer 20 is arranged on the right side. A power conversion device 30 is mounted on the upper part of the drive motor 10. The axle 71 extends outward from both ends of the drive motor 10 and the reducer 20 in the width direction of the vehicle 100.

[0025] The drive shaft of the drive motor 10 has a hollow structure, and one end of the drive shaft is connected to the reduction mechanism (speed change mechanism) 22 of the reducer 20 (see reference). Figure 6 The input side is connected to the speed reduction mechanism 22. Regarding the rotation after being reduced by the speed reduction mechanism 22, the hollow shaft is connected to the drive wheel 72 by the axle 71 connected to the output side of the speed reduction mechanism 22, which passes through the interior of the hollow shaft and protrudes to both ends of the drive motor 10 and the speed reducer 20.

[0026] like Figure 3 As shown, the drive unit 1 is supported by the suspension beam 2 and mounted on the vehicle 100.

[0027] The suspension beam 2 consists of a set of longitudinal beams 81 extending along the longitudinal direction of the vehicle 100, and a set of transverse beams 82 extending along the width direction of the vehicle 100. The set of longitudinal beams 81 and the set of transverse beams 82 define an approximately rectangular shape. The drive unit 1 is fixed to the longitudinal beams 81 and transverse beams 82 via brackets such as sleeves, located inside the rectangular shape of the suspension beam 2.

[0028] An exhaust pipe 51 extends from the engine 50. The exhaust pipe 51 extends from the engine 50 toward a muffler 52 located at the rear of the vehicle 100 and is positioned below the vehicle 100.

[0029] Near suspension beam 2, exhaust pipe 51 is configured to extend from below suspension beam 2 in the longitudinal direction of vehicle 100. Figure 3 (near the anterior side) passes through.

[0030] Here, with the drive unit 1 currently positioned at the rear of the vehicle 100, the following problem exists.

[0031] The exhaust pipe 51 becomes hot (e.g., 200°C) because the hot exhaust gas from the engine 50 passes through it. On the other hand, if the drive motor 10 and the power conversion device 30 are exposed to such high temperatures, their efficiency will decrease. Therefore, it is preferable to configure them so that they are not close to the exhaust pipe 51.

[0032] However, in addition to the drive unit 1, suspension beam 2, and muffler 52, the rear of the vehicle 100 equipped with suspension beam 2 also has suspension devices (not shown). Therefore, the arrangement of exhaust pipe 51 at the rear of the vehicle 100 is limited, and sometimes the distance between drive unit 1 and exhaust pipe 51 cannot be fully achieved.

[0033] In this case, components such as isolation parts and blowers can be installed to prevent heat from the exhaust pipe 51 from being conducted to the drive motor 10. However, if configured in this way, there are problems such as an increase in the number of components, assembly time, and cost.

[0034] Therefore, in this embodiment, as explained below, the heat from the exhaust pipe 51 is not conducted to the drive motor 10 without adding any components.

[0035] like Figure 3 As shown, the exhaust pipe 51 extends from the engine 50 toward the rear of the vehicle 100, near the suspension beam 2. Figure 3 The left side (the reducer 20 side of drive unit 1) is bent. The exhaust pipe 51 is on the front crossbeam 82 and the right side ( Figure 3 The longitudinal beam 81 on the left side bends towards the rear of the vehicle 100 near the intersection point, and is configured to pass directly under the right longitudinal beam 81 along the right longitudinal beam 81. The exhaust pipe 51 then passes through the rear crossbeam 82 and connects to the muffler 52, which is configured to be further rearward than the suspension beam 2.

[0036] Thus, the exhaust pipe 51 is positioned near the lower part of the suspension beam 2, below the front crossbeam 82 and the right longitudinal beam 81 of the suspension beam 2, extending along the shape of these components.

[0037] Figure 4 This is an explanatory diagram showing the drive unit 1 and suspension beam 2 viewed from the rearward side of vehicle 100. Figure 3 The view M.

[0038] like Figure 4As shown, the exhaust pipe 51 is configured to run along the longitudinal beam 81 and the cross beam 82 below the suspension beam 2. Thus, the exhaust pipe 51 is positioned near the suspension beam 2, and the longitudinal beam 81 is located between the exhaust pipe 51 and the reducer 20 near the drive unit 1.

[0039] The suspension beam 2 is made of a metal with a large heat capacity, such as iron. Therefore, the heat conducted from the exhaust pipe 51 to the suspension beam 2 is diffused to all parts of the suspension beam 2 and is quickly released due to the driving wind.

[0040] According to this structure, the heat from the exhaust pipe 51 is isolated by the longitudinal beam 81 and is difficult to conduct to the drive unit 1 side.

[0041] Furthermore, in the drive unit 1, the drive motor 10 is positioned further away from the exhaust pipe 51 than the reducer 20. Figure 4 (Left side of the image). That is, if viewed from the drive motor 10, there is a reducer 20 and a longitudinal beam 81 between it and the exhaust pipe 51.

[0042] According to this structure, the heat from the exhaust pipe 51 is isolated by the longitudinal beam 81 and the reducer 20, thus preventing direct conduction to the drive motor 10 and the power conversion device 30.

[0043] Furthermore, the reducer 20 has a cooling water flow path 211 as described below.

[0044] Figure 5 From the axial direction ( Figure 2 The diagram shows the view of reducer 20 from the direction of sight A. Figure 6 It is a cross-sectional view of drive unit 1 and suspension beam 2, and it is Figure 3 Section VI-VI.

[0045] The reducer 20 is configured such that a reduction mechanism 22 consisting of multiple gears (e.g., a planetary gear mechanism) is housed within a housing 21 having an outer diameter that is approximately cylindrical in shape. Figure 6 ).

[0046] The housing 21 is made of a metal such as aluminum alloy in a cylindrical shape, and has a cooling water flow path 211 on its inner side for the refrigerant (cooling water) to flow through. Figure 5 (As shown by the dashed line). When the cooling water flow path 211 is cut across the housing 21 with a face perpendicular to the direction of rotation, an arc-shaped space is formed on the lower part of the housing 21, opposite to the lower part of the reduction gear 22. This arc-shaped space is formed as a passage extending in the longitudinal direction of the vehicle, and is configured to house the reduction gear 22 (which is housed in the housing 21). Figure 5 The lower side is covered by the dotted line (as shown in the middle).

[0047] A cooling water inlet 212 and a cooling water outlet 213 are provided on the end face 21A of the housing 21 (the axial end opposite to the drive motor 10) to allow cooling water to flow through the cooling water flow path 211. The cooling water inlet 212 and the cooling water outlet 213 are separately arranged on the end face 21A of the reducer 20 in the longitudinal direction of the vehicle 100.

[0048] Specifically, the cooling water inlet 212 is located on the rear side of the vehicle 100 of the reducer 20, and communicates with one end of the arc-shaped cooling water flow path 211. The cooling water outlet 213 is located on the front side of the vehicle 100 of the reducer 20, and communicates with the other upper end of the arc-shaped cooling water flow path 211. The cooling water inlet 212 is positioned at a height higher than the cooling water outlet 213 relative to the road surface.

[0049] The lubricating oil used for lubricating the reduction gear 22 is stored inside the housing 21. The lubricating oil comes into contact with the cooling water flow path 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 flow path 211.

[0050] Moreover, such as Figure 6 As shown, the cooling water flow path 211 of the reducer 20 is formed at a position opposite to the exhaust pipe 51 disposed near the lower part of the reducer 20.

[0051] A portion of the heat from the exhaust pipe 51 is conducted through the longitudinal beam 81 to the lower part of the end face 21A side of the housing 21 of the reducer 20. However, since there is a cooling water flow path 211 in the housing 21, the heat conducted to the housing 21 can be suppressed from being conducted to the drive motor 10 and the power conversion device 30.

[0052] Furthermore, in this embodiment, there is a section between the exhaust pipe 51 and the reducer 20 where the suspension beam 2 (longitudinal beam 81, cross beam 82) may not exist. Even in such a section, the cooling water flow path 211 of the reducer 20, which is in between, can prevent heat conduction from the exhaust pipe 51 to the drive motor 10.

[0053] Furthermore, in the reducer 20, the cooling water inlet 212 is positioned at a height relative to the road surface that is higher than the height relative to the road surface of the cooling water outlet 213. The cooling water flow path 211, which is 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.

[0054] This structure improves the cooling efficiency of the reducer 20 on uphill roads. Specifically, when the vehicle 100 is traveling uphill, the oil level of the lubricating oil inside the reducer 20 (at...) Figure 5As indicated by the dashed line, the oil level is higher at the rear of the vehicle than at the front, corresponding to the slope of the uphill road. Furthermore, when the vehicle 100 is traveling uphill, the torque required by the drive motor 10 and engine 50 increases compared to traveling downhill on a flat road or slope. Therefore, the temperature of the exhaust pipe 51 increases under these conditions.

[0055] Here, as Figure 5 As shown, the rear side of the cooling water flow path 211 (cooling water inlet 212) is at a higher position, so even if the lubricating oil level is tilted rearward, the cooling water inlet 212 is located higher than the tilted lubricating oil level. Thus, the stored lubricating oil is basically cooled entirely by the cooling water.

[0056] Therefore, even when the vehicle 100 is going uphill, the cooling efficiency of the reducer 20 will not be affected. Furthermore, because the cooling water in the cooling water flow path 211 causes the heat conducted from the exhaust pipe 51 to be released quickly, the heat from the exhaust pipe 51 will not be conducted to the drive motor 10.

[0057] And, as Figure 3 As shown, near the cooling water inlet 212 of the housing 21 of the reducer 20, the exhaust pipe 51 is configured such that, when viewed from above, its center (centerline P) is the same as the center (centerline F) of the longitudinal beam 81 in the width direction, or is configured to be further outward than the center in the width direction (on the side separated from the reducer 20).

[0058] Heat from the exhaust pipe 51 is insulated by the longitudinal beam 81 and is not easily conducted to the reducer 20, especially the cooling water inlet 212. The cooling water flowing in from the cooling water inlet 212 is at a lower temperature than the cooling water flowing out from the cooling water outlet 213 before undergoing heat exchange inside the reducer 20. Therefore, the reducer 20 is configured to be free from heat conduction from the exhaust pipe 51 near the cooling water inlet 212, thereby preventing damage to its cooling efficiency.

[0059] In the embodiments of the present invention described above, a vehicle structure is applied to a vehicle 100 having an engine 50, which is equipped with a drive unit 1 consisting of a drive motor 10 and a transmission (reducer 20). The drive unit 1 is configured such that the drive motor 10 and the reducer 20 are connected in series in the width direction of the vehicle 100. The exhaust pipe 51 of the engine 50 extends from near the reducer 20 in the longitudinal direction of the vehicle 100. The reducer 20 has a cooling water flow path 211 for cooling water to flow through at a position opposite to the exhaust pipe 51, which cools the lubricating oil that lubricates the reduction mechanism 22 inside the reducer 20.

[0060] With this structure, the heat from the exhaust pipe 51 is not immediately conducted to the drive motor 10, and the heat conducted to the reducer 20 is quickly removed by the cooling water. Therefore, the drive motor 10 is not affected by the heat from the exhaust pipe 51, and thus, without the need for additional components such as heat shields, the efficiency of the drive motor 10 can be prevented from decreasing. Furthermore, both the drive motor 10 and the power conversion device 30 have housings and cooling water flow paths for the cooling water to circulate.

[0061] In addition, in this embodiment, the reducer 20 has a housing 21 that houses the reduction mechanism 22, and a cooling water flow path 211 is formed in the housing 21. The cooling water flow path 211 is arc-shaped and extends along the lower side of the housing 21 in the vehicle's longitudinal direction.

[0062] According to this structure, the lubricating oil is always cooled by cooling water on the inner circumference of the arc-shaped cooling water flow path 211, so the cooling efficiency of the reducer 20 will not be damaged.

[0063] In addition, in this embodiment, the cooling water inlet 212 and cooling water outlet 213 of the cooling water flow path 211 are separately arranged in the front-rear direction of the housing 21 in the vehicle 100, and one of the cooling water inlet 212 and cooling water outlet 213 is arranged at a higher position relative to the ground compared to the other.

[0064] According to this structure, when the vehicle 100 is traveling uphill, even if the oil level of the lubricating oil is tilted inside the reducer 20, the cooling water flows at a position higher than the tilted oil level, so the cooling efficiency of the reducer 20 will not be damaged.

[0065] In addition, in this embodiment, the cooling water inlet 212 is configured to be located further behind the vehicle 100 than the cooling water outlet 213, and the cooling water inlet 212 is configured at a position higher than the cooling water outlet 213 relative to the ground.

[0066] According to this structure, when the vehicle 100 is going uphill, even if the oil level of the lubricating oil is tilted backward inside the reducer 20, the cooling water inlet 212 is located above the tilted oil level, allowing the cooling water to flow. Therefore, even when going uphill, the cooling efficiency of the reducer 20 will not be affected.

[0067] In addition, in this embodiment, regarding the drive unit 1, the power conversion device 30 that supplies power to the drive motor 10 is disposed on the upper side of the drive motor 10.

[0068] According to this structure, the heat from the exhaust pipe 51 will not be immediately conducted to the power conversion device 30, and the power conversion device 30 is not affected by the heat from the exhaust pipe 51. Therefore, the efficiency of the power conversion device 30 can be prevented from decreasing without adding any components.

[0069] In this embodiment, the drive unit 1 is supported on the suspension beam 2. The suspension beam 2 consists of a set of longitudinal beams 81 extending in the longitudinal direction of the vehicle 100 and a set of transverse beams 82 extending in the width direction of the vehicle 100. The drive unit 1 is disposed inside the approximately rectangular shape defined by the set of longitudinal beams 81 and the set of transverse beams 82. The exhaust pipe 51 is disposed below the longitudinal beams 81 along the longitudinal beams 81.

[0070] With this structure, the heat from the exhaust pipe 51 is isolated by the longitudinal beam 81 and is not easily conducted to the drive unit 1 side, so the efficiency of the drive motor 10 can be prevented from decreasing without adding any components.

[0071] In addition, in this embodiment, the exhaust pipe 51 is located near the cooling water inlet 212 of the reducer 20 and on the lower side of the longitudinal beam 81, further outward than the center of the longitudinal beam 81 in the width direction of the vehicle 100.

[0072] With this structure, the coolant with the lowest temperature flows into the coolant inlet 212 of the reducer 20, and the heat of the exhaust pipe 51 is isolated by the longitudinal beam 81, so the cooling efficiency of the reducer 20 will not be compromised.

[0073] The embodiments and variations of the present invention have been described above. The above embodiments and variations only illustrate a part of the application examples of the present invention, and their purpose is not to limit the technical scope of the present invention to the specific structure of the above embodiments.

[0074] The drive motor 10 of this embodiment can be used as a drive power source for devices other than automobiles, such as various electrical instruments or industrial machinery.

[0075] In addition, in this embodiment, the cooling water inlet 212 in the reducer 20 is located on the rear side of the vehicle 100, but it is not limited to this. It can also be configured such that the cooling water outlet 213 is located on the rear side of the vehicle 100, and the cooling water flows from the front side of the reducer 20 toward the rear side of the vehicle.

[0076] In addition, in this embodiment, the reducer 20 can be configured as a transmission having a transmission mechanism capable of switching multiple reduction gears.

[0077] In this embodiment, the suspension beam 2 (longitudinal beam 81) is configured to be located between the exhaust pipe 51 and the reducer 20, but it is not limited to this configuration. It is acceptable as long as there is no suspension beam 2 between the exhaust pipe 51 and the drive motor 10 and the power conversion device 30, and only the reducer 20 exists. The cooling water flow path 211 of the reducer 20 prevents heat conduction from the exhaust pipe 51 to the drive motor 10 and the power conversion device 30. In this case, the exhaust pipe 51 can be positioned near the side of the housing 21 where the cooling water flow path 211 is located, rather than below the reducer 20.

Claims

1. A vehicle-mounted structure for a drive unit, comprising a drive motor and a transmission, mounted on a vehicle having an engine, wherein... The drive unit is configured by connecting the drive motor and the transmission in series along the width direction of the vehicle. The engine's exhaust pipe is provided near the transmission, extending through the vehicle in a longitudinal direction. The transmission has a cooling water flow path located opposite the exhaust pipe, through which cooling water cools the lubricating oil that lubricates the transmission mechanism within the transmission. The cooling water flow path is not in fluid communication with the exhaust pipe.

2. The vehicle-mounted structure of the drive unit according to claim 1, wherein, The transmission has a housing that houses the shift mechanism. The cooling water flow path is formed in the housing. The cooling water flow path is formed in an arc shape on the lower side of the housing, opposite to the lower part of the transmission mechanism.

3. The vehicle-mounted structure of the drive unit according to claim 2, wherein, In the housing, the cooling water inlet and cooling water outlet of the cooling water flow path are separately configured in the longitudinal direction of the vehicle. One of the cooling water inlet and the cooling water outlet is positioned at a higher elevation relative to the road surface compared to the other.

4. The vehicle-mounted structure of the drive unit according to claim 3, wherein, The cooling water inlet is configured to be located further rearward than the cooling water outlet of the vehicle. The cooling water inlet is positioned at a higher elevation relative to the road surface compared to the cooling water outlet.

5. The vehicle-mounted structure of the drive unit according to any one of claims 1 to 4, wherein, The drive unit also includes a power conversion device mounted on the upper part of the drive motor for supplying power to the drive motor.

6. The vehicle-mounted structure of the drive unit according to any one of claims 1 to 4, wherein, The drive unit is supported by the suspension beam. The suspension beam consists of the following components: a set of longitudinal beams extending along the longitudinal direction of the vehicle; and a set of transverse beams extending along the width direction of the vehicle. The drive unit is positioned inside an approximately rectangular shape defined by a set of longitudinal beams and a set of transverse beams. The exhaust pipe is disposed below the longitudinal beam along the longitudinal beam.

7. The vehicle-mounted structure of the drive unit according to claim 6, wherein, The exhaust pipe is located near the coolant inlet of the transmission, on the lower side of the longitudinal beam, positioned further outward than the center of the longitudinal beam in the vehicle width direction.

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