Drive unit arrangement structure

Abstract

To provide a drive unit arrangement structure that can efficiently cool a power control device positioned above a rotating electric machine. [Solution] The drive unit 5 has an arrangement structure that includes a motor generator, an inverter 6 provided above the motor generator and controlling the power supplied to the motor generator, and a drive case 8 housing the motor generator and the inverter 6, and is positioned below the floor panel of the vehicle 1, and a cross member 3 positioned in front of the drive unit 5 and extending in the vehicle width direction, and the drive unit 5 is elastically supported by the cross member 3 by a front mounting device 10. The drive unit 5 is positioned in a forward-tilted state such that the upper front end 8a of the drive case 8 is located below the lower surface of the cross member 3, and the upper rear end 8b of the drive case 8 is located above the lower surface 3a of the cross member 3.

Description

Technical Field

[0001] The present invention relates to an arrangement structure of a drive device.

Background Art

[0002] Conventionally, a power unit suspension structure of an electric vehicle is known in which a power unit composed of a motor and a speed reducer is arranged below a rear floor, and a front portion of the power unit is suspended from a front cross frame portion via a motor-side front mount bracket (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional power unit suspension structure of an electric vehicle, it is possible to cool the lower part of the power unit with the running wind, but the upper part of the power unit is not structured to be cooled by the running wind. That is, there is no structure for actively taking in the running wind between the rear floor and the power unit.

[0005] In a power unit having a motor, a power control device such as an inverter is often arranged above the power unit. However, in the conventional power unit suspension structure of an electric vehicle, it is difficult to actively cool the electrical equipment arranged above the power unit by the running wind.

[0006] The present invention has been made paying attention to the above circumstances, and an object thereof is to provide an arrangement structure of a drive device that can efficiently cool a power control device arranged above a rotating electric machine.

Means for Solving the Problems

[0007] The present invention relates to a drive unit arrangement structure comprising a drive unit located below the floor panel of a vehicle, having a rotating electric machine, a power control device provided above the rotating electric machine for controlling the power supplied to the rotating electric machine, and a case housing the rotating electric machine and the power control device; a cross member located in front of the drive unit and extending in the vehicle width direction; and a mounting device that elastically supports the drive unit on the cross member, wherein the drive unit is arranged in a forward-tilted state such that the upper front end of the case is located below the lower surface of the cross member and the upper rear end of the case is located above the lower surface of the cross member. [Effects of the Invention]

[0008] As described above, according to the present invention, a power control device positioned above a rotating electric machine can be efficiently cooled. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a diagram showing the arrangement structure of a drive unit according to one embodiment of the present invention, and is a bottom view of the rear of a vehicle. [Figure 2] Figure 2 is a cross-sectional view taken along the line II-II in Figure 1. [Figure 3] Figure 3 is a cross-sectional view taken along the line III-III in Figure 1. [Modes for carrying out the invention]

[0010] An arrangement structure for a drive unit according to one embodiment of the present invention comprises a drive unit located below the floor panel of a vehicle, having a rotating electric machine, a power control device provided above the rotating electric machine and controlling the power supplied to the rotating electric machine, and a case housing the rotating electric machine and the power control device; a cross member located in front of the drive unit and extending in the vehicle width direction; and a mounting device that elastically supports the drive unit on the cross member, wherein the drive unit is arranged in a forward-tilted state such that the upper front end of the case is located below the lower surface of the cross member and the upper rear end of the case is located above the lower surface of the cross member.

[0011] As a result, the drive unit arrangement structure according to one embodiment of the present invention can efficiently cool the power control device which is positioned above the rotating electric machine. [Examples]

[0012] The following describes the arrangement structure of a drive device according to one embodiment of the present invention with reference to the drawings. Figures 1 to 3 show the arrangement structure of a drive device according to one embodiment of the present invention.

[0013] First, let me explain the structure. In Figures 1 to 3, the vertical, horizontal, and vertical directions are based on the drive unit as it is positioned on the vehicle. The horizontal direction of the vehicle is defined as the horizontal direction, the horizontal direction (vehicle width direction) as the horizontal direction, and the vertical direction (height direction) as the vertical direction.

[0014] As shown in Figure 1, vehicle 1 is equipped with a left side member 2L, a right side member 2R, a cross member 3, and a sub-side member 4.

[0015] The left side member 2L and the right side member 2R are spaced apart in the vehicle width direction and extend in the front-to-back direction. The vehicle width direction is the same as the left-to-right direction.

[0016] The cross member 3 extends in the vehicle width direction, and its left and right ends are connected to the left side member 2L and the right side member 2R. The sub-side member 4 has its front end connected to the cross member 3 and its rear end connected to a rear cross member (not shown).

[0017] A drive device 5 is arranged in the space surrounded by the left side member 2L, the sub-side member 4, and the cross member 3.

[0018] Specifically, the drive device 5 is arranged between the left side member 2L and the sub-side member 4 in the vehicle width direction and behind the cross member 3 in the front-rear direction. That is, the cross member 3 is arranged in front of the drive device 5.

[0019] The drive device 5 includes a motor generator (not shown) as a rotary electric machine, an inverter 6 (see Figure 2) as a power control device provided above the motor generator for controlling the power supplied to the motor generator, a speed reducer (not shown) for reducing the driving force (rotational speed) of the motor generator, and a differential device (not shown) for transmitting the power of the speed reducer to the left and right rear wheels (not shown) via the left drive shaft 7L and the right drive shaft 7R.

[0020] The motor generator, the inverter 6, the speed reducer, and the differential device are housed in a drive case 8. The drive case 8 of this embodiment constitutes the case.

[0021] The motor generator has a function as an electric motor driven by the power supplied from a high-voltage battery (not shown) via the inverter 6, and a function as a generator for generating electricity by the reverse driving force input from the differential device.

[0022] The inverter 6 converts DC power supplied from the high-voltage battery into three-phase AC power and supplies it to the motor generator, and converts the three-phase AC power generated by the motor generator into DC power to charge the high-voltage battery. The high-voltage battery is composed of a secondary battery such as a lithium-ion battery.

[0023] As shown in Figure 2, the inverter 6 is positioned at the top, above the motor generator, reduction gear, and differential, and extends from the upper front end 8a to the upper rear end 8b of the drive case 8 in the space above the drive case 8.

[0024] The drive unit 5 is located below the floor panel 9 and is situated at the rear of the vehicle 1. At the front of the vehicle 1 are a drive source (not shown), the left and right drive shafts to which the power from the drive source is transmitted, and the left and right front wheels.

[0025] In this embodiment, vehicle 1 can be driven in two-wheel drive mode when only the front drive source is driven, and in four-wheel drive mode when both the drive source and the drive unit 5 are driven. The front drive source is not particularly limited.

[0026] The drive unit 5 is elastically supported on the cross member 3 by the front mounting device 10. The front mounting device 10 includes a mounting bush 11 and a mounting bracket 12. In this embodiment, the front mounting device 10 constitutes the mounting device.

[0027] The mounting bush 11 comprises an inner cylinder 11A whose central axis extends in the front-rear direction, an outer cylinder 11B provided radially outward from the inner cylinder 11A and whose central axis also extends in the front-rear direction, and a mounting rubber 11C provided radially between the inner cylinder 11A and the outer cylinder 11B and connecting the inner cylinder 11A and the outer cylinder 11B, and is formed in a cylindrical shape overall.

[0028] The inner cylinder 11A is fastened (connected) to the lower part of the front wall 8A of the drive case 8 by bolts 13A, and the mount bush 11 is positioned so that its central axis extends in the front-rear direction.

[0029] The mount bracket 12 has a member mounting portion 12A that extends in the vehicle width direction and is fastened (connected) to the lower surface 3a of the cross member 3 by bolts 13B, an annular portion 12B that accommodates the mount bush 11 when the mount bush 11 is press-fitted into it, and a connecting portion 12C that connects the annular portion 12B and the member mounting portion 12A.

[0030] The connecting portion 12C is inclined diagonally upward and forward from the annular portion 12B toward the member mounting portion 12A, such that the annular portion 12B is located behind the member mounting portion 12A and the member mounting portion 12A is located in front of the annular portion 12B.

[0031] As shown in Figure 1, the drive unit 5 is fitted with a left mount device 14 and a right mount device 15, and the drive unit 5 is elastically supported by the left side member 2L and the sub-side member 4 by the left mount device 14 and the right mount device 15.

[0032] As shown in Figure 3, the left mounting device 14 has a cylindrical mounting bush 16 and a mounting bracket 17. The mounting bush 16 comprises an inner cylinder 16A whose central axis extends in the vehicle width direction, an outer cylinder 16B provided radially outward from the inner cylinder 16A, and a mounting rubber 16C provided radially between the inner cylinder 16A and the outer cylinder 16B, connecting the inner cylinder 16A and the outer cylinder 16B. The inner cylinder 16A is fastened (connected) to the left side wall 8B of the drive case 8 by a bolt 13C.

[0033] The mount bracket 17 has a member mounting portion 17A which is fastened (connected) to the lower surface of the left side member 2L by a bolt 13D, an annular portion 17B which accommodates the mount bush 16 when the mount bush 16 is press-fitted into it, and a connecting portion 17C which connects the annular portion 17B and the member mounting portion 17A.

[0034] The member mounting portion 17A is located above the annular portion 17B, and the connecting portion 17C extends in the vehicle width direction.

[0035] As shown in Figures 1 and 3, the drive unit 5 is elastically supported on the sub-side member 4 by the right mounting device 15.

[0036] As shown in Figure 3, the right mounting device 15 has a cylindrical mounting bush 18 and a mounting bracket 19. As shown in Figure 3, the mounting bush 18 has an inner cylinder 18A whose central axis extends in the vehicle width direction, an outer cylinder 18B provided radially outward from the inner cylinder 18A, and a mounting rubber 18C provided radially between the inner cylinder 18A and the outer cylinder 18B, connecting the inner cylinder 18A and the outer cylinder 18B. The inner cylinder 18A is fastened (connected) to the right side wall 8C of the drive case 8 by a bolt 13E.

[0037] The mounting bracket 19 has a member mounting portion 19A that is fastened (connected) to the lower surface of the sub-side member 4 by bolts 13F (see Figure 1), and an annular portion 19B that houses the mounting bush 18 when the mounting bush 18 is press-fitted into it and is connected to the member mounting portion 19A. The member mounting portion 19A is located above the annular portion 19B.

[0038] The front mounting device 10, the left mounting device 14, and the right mounting device 15 have their mounting bushings 11, 16, and 18, which are fastened (connected) to the drive case 8, positioned at the lowest position.

[0039] In other words, the drive unit 5 is elastically supported by the left side member 2L, the sub-side member 4, and the cross member 3, by being suspended from the left side member 2L, the sub-side member 4, and the cross member 3 by the front mounting device 10, the left mounting device 14, and the right mounting device 15.

[0040] As shown in Figure 2, the drive unit 5 is positioned in a forward-tilting position such that the upper front end 8a of the drive case 8 is located below the lower surface 3a of the cross member 3, and the upper rear end 8b is located above the lower surface 3a of the cross member 3.

[0041] The upper surface 8c of the upper wall 8D of the drive case 8 is formed as a plane that slopes from the upper front end 8a to the upper rear end 8b. In this embodiment, the upper surface 8c constitutes the upper surface of the case. Hereinafter, the upper surface 8c of the upper wall 8D of the drive case 8 will be referred to as the upper surface 8c of the drive case 8.

[0042] As shown in Figure 2, a bulge 9A is formed in the floor panel 9, and the bulge 9A bulges upward from the horizontal portion 9a of the floor panel 9. The bulge 9A has an inclined portion 9b, a left wall portion 9c, a right wall portion 9d, and a rear wall portion 9e (see Figure 3).

[0043] The inclined portion 9b faces the upper surface 8c of the drive case 8 in the vertical direction and is inclined upward from the front end 9f to the rear end 9g. In other words, a gap S1 is formed between the inclined portion 9b and the upper surface 8c of the drive case 8.

[0044] The gap S2 between the upper front end 8a side of the drive case 8 and the inclined portion 9b is larger than the gap S3 between the upper rear end 8b side of the drive case 8 and the inclined portion 9b, and the gap S1 between the upper surface 8c of the drive case 8 and the inclined portion 9b is formed to gradually decrease as you move from the upper front end 8a side of the drive case 8 towards the upper rear end 8b. The gap S1 includes the gaps S2 and S3.

[0045] As the drive unit 5 is positioned in a forward-tilting position, it extends into the passenger compartment from the horizontal portion 9a of the floor panel 9. This prevents the vertical dimensions of the vehicle 1 from increasing, thereby enabling a more compact vehicle 1.

[0046] As shown in Figure 2, the lower surface 3a of the cross member 3 is inclined parallel to the upper surface 8c of the drive case 8. In other words, the lower surface 3a of the cross member 3, the inclined portion 9b, and the upper surface 8c of the drive case 8 are inclined parallel to the horizontal plane.

[0047] The rear wall portion 9e extends downward from the rear end portion 9g of the inclined portion 9b, and the lower end portion 9h of the rear wall portion 9e is located below the upper rear end portion 8b of the drive case 8.

[0048] As shown in Figure 3, the left side wall portion 9c extends downward from the left end of the inclined portion 9b, and the lower end portion 9i of the left side wall portion 9c is located below the upper rear end portion 8b of the drive case 8.

[0049] The right side wall portion 9d extends downward from the right end of the inclined portion 9b, and the lower end portion 9j of the right side wall portion 9d is located below the upper rear end portion 8b of the drive case 8.

[0050] Next, the effects of the arrangement structure of the drive unit 5 in this embodiment will be explained. The drive unit 5 of this embodiment has an arrangement structure that includes a motor generator, an inverter 6 provided above the motor generator and controlling the power supplied to the motor generator, and a drive case 8 housing the motor generator and the inverter 6, and is located below the floor panel of the vehicle 1.

[0051] Furthermore, the arrangement structure of the drive unit 5 in this embodiment includes a cross member 3 positioned in front of the drive unit 5 and extending in the left-right direction (vehicle width direction), and a front mounting device 10 that elastically supports the drive unit 5 on the cross member 3.

[0052] The drive unit 5 is positioned in a forward-tilting position such that the upper front end 8a of the drive case 8 is located below the lower surface of the cross member 3, and the upper rear end 8b of the drive case 8 is located above the lower surface 3a of the cross member 3.

[0053] In other words, the drive unit 5 is positioned in a forward-tilting position such that its upper front end 8a is located lower than its upper rear end 8b.

[0054] This prevents the airflow W1 flowing from the front to the rear of the vehicle 1 from being obstructed by the cross member 3, allowing it to be drawn into the gap S1 between the upper front end 8a of the drive case 8 and the floor panel 9 (inclined portion 9b). The airflow W1 that has entered the gap S1 can then be directed along the upper surface 8c of the drive case 8.

[0055] Therefore, the inverter 6, which is located at the top of the drive case 8, can be cooled by the low-temperature running airflow W1, thereby improving the cooling efficiency of the inverter 6.

[0056] Alternatively, a cooling water inlet pipe and a cooling water outlet pipe (not shown) may be connected to the front wall 8A of the drive case 8, and the inverter 6 may be cooled by the cooling water introduced into the drive case 8 from the cooling water inlet pipe, and the cooling water used to cool the inverter 6 may be discharged from the drive case 8 through the cooling water outlet pipe. In this way, the inverter 6 can be cooled more effectively by the cooling water and the airflow W1.

[0057] Furthermore, according to the arrangement structure of the drive device 5 in this embodiment, the upper surface 8c of the drive case 8 is formed as a planar inclined surface that slopes from the upper front end 8a toward the upper rear end 8b.

[0058] In addition, the floor panel 9 faces the upper surface 8c of the drive case 8 in the vertical direction and has an inclined portion 9b that slopes upward from the front end 9f to the rear end 9g, and a gap S1 is formed between the upper surface 8c of the drive case 8 and the inclined portion 9b.

[0059] This allows a large amount of airflow W1 taken in from between the upper front end 8a and the inclined portion 9b of the drive case 8 into the gap S1 between the drive case 8 and the floor panel 9 to flow along the upper surface 8c of the drive case 8, thereby cooling the inverter 6 more effectively.

[0060] Furthermore, according to the arrangement structure of the drive unit 5 in this embodiment, the lower surface 3a of the cross member 3 is inclined parallel to the upper surface 8c of the drive case 8.

[0061] This allows the airflow W1 from the front to the rear of the vehicle 1 to be directed along the lower surface 3a of the cross member 3 into the gap S1 between the inclined portion 9b and the upper surface 8c of the drive case 8, thereby allowing more airflow W1 to be drawn into the gap S1 between the inclined portion 9b and the upper surface 8c of the drive case 8. As a result, the inverter 6 can be cooled more effectively.

[0062] Furthermore, according to the arrangement structure of the drive device 5 in this embodiment, the gap S1 between the upper surface 8c of the drive case 8 and the inclined portion 9b is formed to gradually decrease as you move from the upper front end 8a side of the drive case 8 towards the upper rear end 8b side.

[0063] This suppresses turbulence in the airflow through the gap S1, allowing the running air W1 to flow smoothly along the upper surface 8c of the drive case 8.

[0064] Furthermore, since the gap S1 between the upper surface 8c of the drive case 8 and the inclined portion 9b gradually decreases from front to rear, the airflow velocity on the downstream side of the gap S1 can be increased, and more air can be drawn into the gap S1 from the upstream side, where the gap is larger than on the downstream side. As a result, the inverter 6 can be cooled more effectively by the airflow W1.

[0065] Furthermore, according to the arrangement structure of the drive unit 5 in this embodiment, the floor panel 9 has a rear wall portion 9e extending downward from the rear end portion 9g of the inclined portion 9b, and the lower end portion 9h of the rear wall portion 9e is located below the upper rear end portion 8b of the drive case 8.

[0066] This allows the airflow W1 that flows through the gap S1 between the inclined section 9b and the upper surface 8c of the drive case 8 to collide with the rear wall section 9e and be directed downwards.

[0067] Therefore, the airflow W2 (see Figure 2) can be passed through the gap S4 between the rear wall 9e and the upper part of the rear wall 8E of the drive case 8, allowing the rear side of the inverter 6 to be cooled by the low-temperature airflow W2. As a result, a wide area of ​​the inverter 6 can be cooled, and the inverter 6 can be cooled more effectively.

[0068] Furthermore, according to the arrangement structure of the drive unit 5 in this embodiment, the floor panel 9 has a left wall portion 9c extending downward from the left end of the inclined portion 9b and a right wall portion 9d extending downward from the right end of the inclined portion 9b, and the lower end portion 9i of the left wall portion 9c and the lower end portion 9j of the right wall portion 9d are located below the upper rear end portion 8b of the drive case 8.

[0069] This allows the airflow W1 that flows through the gap S1 between the inclined section 9b and the upper surface 8c of the drive case 8 to flow from front to rear along the left wall section 9c and the right wall section 9d, thereby suppressing leakage outwards to the left and right from the gap S1.

[0070] Therefore, more airflow W1 can be directed through the gap S1 between the inclined section 9b and the upper surface 8c of the drive case 8, allowing the inverter 6 to be cooled more effectively.

[0071] While embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that modifications can be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims. [Explanation of symbols]

[0072] 1 vehicle 3 Cross Member 3a Bottom surface (bottom surface of the cross member) 5. Drive unit 6. Inverter (Power Control Device) 8 Drive Case (Case) 8a Upper front end 8b Upper rear end 8c Top surface (top of the case) 9 Floor Panels 9c Left side wall 9d Right side wall 9e Rear wall 9h Lower end (lower end of rear wall) 9i Lower end (lower end of left wall) 9j Lower end (lower end of right side wall) 10 Front mounting device (mounting device) S1 Gap (the gap between the top surface of the case and the slanted part)

Claims

1. A drive unit having a rotating electric machine, a power control device provided above the rotating electric machine and controlling the power supplied to the rotating electric machine, and a case housing the rotating electric machine and the power control device, and positioned below the floor panel of the vehicle, A cross member positioned in front of the aforementioned drive unit and extending in the vehicle width direction, An arrangement structure for a drive device comprising a mounting device that elastically supports the drive device on the cross member, The drive unit is characterized by being arranged in a forward-tilting position such that the upper front end of the case is located below the lower surface of the cross member, and the upper rear end of the case is located above the lower surface of the cross member.

2. The upper surface of the case is formed as a planar inclined surface that slopes upward from the upper front end to the upper rear end. The floor panel faces the upper surface of the case in the vertical direction and has an inclined portion that slopes upward from the front end to the rear end. The drive device arrangement structure according to claim 1, characterized in that a gap is formed between the upper surface of the case and the inclined portion.

3. The drive device arrangement structure according to claim 2, characterized in that the lower surface of the cross member is inclined parallel to the upper surface of the case.

4. The arrangement structure of the drive device according to claim 2 or 3, characterized in that the gap between the upper surface of the case and the inclined portion is formed to gradually decrease as the case moves from the upper front end to the upper rear end.

5. The drive device arrangement structure according to claim 2 or 3, characterized in that the floor panel has a rear wall portion extending downward from the rear end of the inclined portion, and the lower end of the rear wall portion is located below the upper rear end of the case.

6. The drive device arrangement structure according to claim 4, characterized in that the floor panel has a rear wall portion extending downward from the rear end of the inclined portion, and the lower end of the rear wall portion is located below the upper rear end of the case.

7. The floor panel has a left wall portion extending downward from the left end of the inclined portion and a right wall portion extending downward from the right end of the inclined portion. The drive device arrangement structure according to claim 2 or 3, characterized in that the lower ends of the left wall portion and the right wall portion are located below the upper surface of the case.

8. The floor panel has a left wall portion extending downward from the left end of the inclined portion and a right wall portion extending downward from the right end of the inclined portion. The drive device arrangement structure according to claim 4, characterized in that the lower ends of the left wall portion and the right wall portion are located below the upper surface of the case.

9. The floor panel has a left wall portion extending downward from the left end of the inclined portion and a right wall portion extending downward from the right end of the inclined portion. The drive device arrangement structure according to claim 5, characterized in that the lower ends of the left wall portion and the right wall portion are located below the upper surface of the case.

10. The floor panel has a left wall portion extending downward from the left end of the inclined portion and a right wall portion extending downward from the right end of the inclined portion. The drive device arrangement structure according to claim 6, characterized in that the lower ends of the left wall portion and the right wall portion are located below the upper surface of the case.

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