Drive unit arrangement structure

Abstract

This invention provides a drive unit arrangement structure that ensures ventilation around the breather opening and improves breather performance. [Solution] The upper surface 8c of the drive case 8 is formed as an inclined surface that slopes upward from the upper front end 8a to the upper rear end 8b, and the floor panel 9 is inclined along the upper surface 8c of the drive case 8, facing the upper surface 8c of the drive case 8 in the vertical direction, and has an inclined portion 9b at which the rear end 9e is located at the highest position within the floor panel 9. The rear part 8d of the drive case 8 enters into a space 31 enclosed by a virtual horizontal plane 30 passing through the lower end of the inclined portion 9b, the inclined portion 9b and the rear wall portion 9c, and a breather opening 8e is formed in the rear part 8d of the drive case 8, which connects the inside and outside of the drive case 8.

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] However, in the conventional power unit suspension structure of an electric vehicle, although it is possible to cool the lower part of the power unit with the running wind, the upper part of the power unit is not structured to be cooled with the running wind. That is, it is difficult to actively introduce the running wind between the rear floor and the power unit.

[0005] In the power unit, the breather port is often formed at the upper part of the power unit. However, in the conventional power unit suspension structure of an electric vehicle, it is difficult to introduce the running wind above the power unit, so it is difficult to ensure the air permeability around the breather port, and it is difficult to ensure the breather performance.

[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 ensure the air permeability around the breather port and improve the breather performance. [Means for solving the problem]

[0007] The present invention relates to a drive unit arranged below a floor panel, wherein the drive unit comprises 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, wherein the drive unit is arranged in a forward-tilting position such that the upper front end of the case is located below the upper rear end of the case, the upper surface of the case is formed as an inclined surface that slopes upward from the upper front end to the upper rear end, the floor panel is inclined in the vertical direction opposite to the upper surface of the case and along the upper surface of the case, and has an inclined portion at its rear end that is the highest point within the floor panel, a part of the case fits into a space enclosed by a virtual horizontal plane passing through the lower end of the inclined portion and the inclined portion, and a breather port is formed in a part of the case that communicates the inside and outside of the case. [Effects of the Invention]

[0008] As described above, according to the present invention, it is possible to ensure airflow around the breather opening and improve breather performance. [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(a) is a cross-sectional view taken along the line II-II in Figure 1, and Figure 2(b) is a cross-sectional view of a breather opening located at a different position from the breather opening in Figure 2(a) and its surrounding area. [Modes for carrying out the invention]

[0010] An arrangement structure for a drive unit according to one embodiment of the present invention has a drive unit arranged below a floor panel, the drive unit comprising 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, the drive unit arrangement structure is tilted forward so that the upper front end of the case is located below the upper rear end of the case, the upper surface of the case is formed as an inclined surface that slopes upward from the upper front end to the upper rear end, the floor panel has an inclined portion that faces the upper surface of the case in the vertical direction and slopes along the upper surface of the case, with the rear end being the highest point within the floor panel, a part of the case fits into a space enclosed by a virtual horizontal plane passing through the lower end of the inclined portion and the inclined portion, and a breather port is formed in a part of the case that communicates the inside and outside of the case.

[0011] As a result, the arrangement structure of the drive unit according to one embodiment of the present invention can ensure airflow around the breather port and improve breather performance. [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 and 2 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 and 2, the vertical, horizontal, and vertical directions are defined with reference to 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-rear 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 disposed 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 disposed 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 disposed 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 Fig. 2(a)) 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 the present 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 the DC power supplied from the high-voltage battery into three-phase AC power and supplies it to the motor generator, or 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, for example.

[0023] As shown in FIG. 2(a), the inverter 6 is disposed at the uppermost position so as to be located above the motor generator, the reduction gear, and the differential device, and extends from the upper front end portion 8a to the upper rear end portion 8b of the drive case 8 in the space above the drive case 8.

[0024] The drive device 5 is disposed below the floor panel 9 and is located at the rear part of the vehicle 1. In the front part of the vehicle 1, there are arranged drive sources (not shown in any figure), left and right drive shafts to which the power of the drive sources is transmitted, and left and right front wheels.

[0025] In the vehicle 1 of the present embodiment, when only the front drive source is driven, the vehicle runs in a two-wheel drive mode, and when both the drive source and the drive device 5 are driven, the vehicle runs in a four-wheel drive mode. The front drive source is not particularly limited.

[0026] The drive device 5 is elastically supported by the front mount device 10 on the cross member 3. As shown in FIG. 2(a), the front mount device 10 has a mount bush 11 and a mount bracket 12. The front mount device 10 of the present embodiment constitutes the mount device.

[0027] The mount bush 11 includes an inner cylinder 11A whose central axis extends in the front-rear direction, an outer cylinder 11B provided radially outward of the inner cylinder 11A and whose central axis extends in the front-rear direction, and a mount rubber 11C provided between the inner cylinder 11A and the outer cylinder 11B in the radial direction to connect the inner cylinder 11A and the outer cylinder 11B, and is formed in a cylindrical shape as a whole.

[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] The left mounting device 14 has a mounting bracket 16. The mounting bracket 16 has a member mounting portion 16A that is fastened (connected) to the lower surface of the left side member 2L by bolts 13C, an annular portion 16B that accommodates a cylindrical mounting bush (not shown) when it is press-fitted, and a connecting portion 16C that connects the annular portion 16B and the member mounting portion 16A. The mounting bush is fastened to the left side wall 8B of the drive case 8 by bolts 13D.

[0033] The member mounting portion 16A is located above the annular portion 16B, and the connecting portion 16C extends in the vehicle width direction.

[0034] The right mounting device 15 has a mounting bracket 17. The mounting bracket 17 has a member mounting portion 17A that is fastened (connected) to the lower surface of the sub-side member 4 by bolts 13E, and an annular portion 17B that houses a cylindrical mounting bush (not shown) by press-fitting a mounting bush and is connected to the member mounting portion 17A. The member mounting portion 17A is located above the annular portion 17B. The mounting bush is fastened to the right side wall 8C of the drive case 8 by bolts 13F.

[0035] The front mounting device 10, the left mounting device 14, and the right mounting device 15 have the mounting bush 11 fastened (connected) to the drive case 8, the mounting bush of the mounting bracket 16, and the mounting bush of the mounting bracket 17 positioned at the lowest position.

[0036] 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.

[0037] As shown in Figure 2(a), 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 3a of the cross member 3, and the upper rear end 8b is located above the lower surface 3a of the cross member 3.

[0038] 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.

[0039] 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 and a rear wall portion 9c.

[0040] 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 9d to the rear end 9e. In other words, a gap S1 is formed between the inclined portion 9b and the upper surface 8c of the drive case 8.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] The rear wall portion 9c extends downward from the rear end portion 9e of the inclined portion 9b, and the lower end portion 9f of the rear wall portion 9c is located below the upper rear end portion 8b of the drive case 8 and the breather opening 8e, which will be described later.

[0045] As shown in Figure 2(a), the inclined section 9b has its rear end 9e at the highest position within the floor panel 9, and its front end 9d at the lowest position. In other words, the front end 9d of the inclined section 9b constitutes the lower end of the inclined section 9b.

[0046] When a virtual horizontal plane 30 is set that passes through the front end 9d of the inclined portion 9b, the rear portion 8d of the drive case 8 is contained within the space 31 enclosed by the virtual horizontal plane 30, the inclined portion 9b, and the rear wall portion 9c. Note that the rear portion 8d of the drive case 8 only needs to be contained within the space enclosed by the virtual horizontal plane 30 and the inclined portion 9b in at least the vertical direction.

[0047] A breather opening 8e is formed at the upper end of the rear 8d of the drive case 8, and the breather opening 8e is formed in front of the rear end 9e of the inclined portion 9b. In other words, the breather opening 8e enters the space 31 enclosed by the virtual horizontal plane 30, the inclined portion 9b, and the rear wall portion 9c.

[0048] Furthermore, a breather chamber is formed at the top of the drive case 8, which communicates with the breather port 8e. The breather chamber is located in a space 31 surrounded by a virtual horizontal plane 30, an inclined portion 9b, and a rear wall portion 9c.

[0049] The breather port 8e connects the inside and outside of the drive case 8, allowing air to flow in and out of the inside of the drive case 8 (breather chamber) through the breather port 8e. The rear part 8d in this embodiment constitutes part of the case.

[0050] When the temperature of the drive case 8 decreases, the pressure inside the drive case 8 decreases. When the pressure inside the drive case 8 falls below atmospheric pressure, outside air is drawn into the drive case 8 through the breather port 8e. This maintains the pressure inside the drive case 8 at atmospheric pressure.

[0051] On the other hand, as the temperature inside the drive case 8 rises, the pressure inside the drive case 8 also rises. When the pressure inside the drive case 8 becomes higher than atmospheric pressure, the air inside the drive case 8 is expelled through the breather port 8e. This maintains the pressure inside the drive case 8 at atmospheric pressure.

[0052] Next, the effects of the arrangement structure of the drive unit 5 in this embodiment will be explained. The drive unit 5 in this embodiment has a drive unit 5 positioned below the floor panel 9. The drive unit 5 comprises 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. The drive case 8 is positioned in a forward-tilting position such that the upper front end 8a is located below the upper rear end 8b of the drive case 8.

[0053] The upper surface 8c of the drive case 8 is formed as a planar inclined surface that slopes upward from the upper front end 8a to the upper rear end 8b, and the floor panel 9 is inclined along the upper surface 8c of the drive case 8, facing the upper surface 8c of the drive case 8 in the vertical direction, and has an inclined portion 9b at which the rear end 9e is located at the highest position within the floor panel 9.

[0054] This allows the airflow W1 to be easily drawn in from between the upper front end 8a of the drive case 8 and the inclined portion 9b into the gap S1 between the inclined portion 9b and the upper surface 8c of the drive case 8, and the airflow W1 can 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] 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.

[0057] 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.

[0058] 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.

[0059] Furthermore, according to the arrangement structure of the drive unit 5 in this embodiment, the rear portion 8d of the drive case 8 enters into a space 31 surrounded by a virtual horizontal plane 30 passing through the lower end of the inclined portion 9b, the inclined portion 9b, and the rear wall portion 9c, and a breather port 8e is formed in the rear portion 8d of the drive case 8, which connects the inside and outside of the drive case 8.

[0060] As a result, compared to the case where the drive unit 5 is positioned without tilting forward and the breather opening 8e is formed at the upper end of the rear 8d of the drive case 8, the breather opening 8e can be formed at a higher position because the breather opening 8e can be formed at the upper end of the rear 8d of the drive case 8 of the tilted drive unit 5.

[0061] In addition, sufficient ventilation around the breather port 8e can be ensured by the airflow W1 that flows through the gap S1 between the upper surface 8c and the inclined portion 9b of the drive case 8.

[0062] In other words, if air accumulates in the gap S1 between the upper surface 8c and the inclined portion 9b of the drive case 8, the air accumulated in the gap S1 may prevent the air inside the drive case 8 from being easily discharged through the breather port 8e, and may also prevent air from being easily drawn into the drive case 8.

[0063] According to the arrangement structure of the drive unit 5 in this embodiment, air stagnation in the gap S1 between the upper surface 8c and the inclined portion 9b of the drive case 8 is suppressed, and sufficient ventilation around the breather port 8e is ensured. As a result, the efficiency of air inflow and outflow to and from the drive case 8 can be increased, and breather performance can be improved.

[0064] Furthermore, according to the arrangement structure of the drive unit 5 in this embodiment, since the lower surface 3a of the cross member 3 is inclined parallel to the upper surface 8c of the drive case 8, the airflow W1 flowing from the front to the rear of the vehicle 1 can 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.

[0065] Therefore, more airflow W1 can be taken into the gap S1 between the inclined section 9b and the upper surface 8c of the drive case 8. As a result, the inverter 6 can be cooled more effectively, and the airflow around the breather port 8e can be improved more effectively.

[0066] In addition, when the vehicle 1 is submerged in water and the water rises close to the floor panel 9, an air layer can be formed in the space 31, which can prevent water from entering the inside of the drive case 8 through the breather port 8e.

[0067] Furthermore, since the breather port 8e can be positioned at a high location, it is difficult for foreign objects such as flying stones to reach the breather port 8e when the vehicle 1 is in motion, and it is difficult for foreign objects to enter the inside of the drive case 8 from the breather port 8e.

[0068] Furthermore, according to the arrangement structure of the drive unit 5 in this embodiment, the drive unit 5 has a cross member 3 positioned in front of it 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.

[0069] 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.

[0070] 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.

[0071] Furthermore, according to the floor panel arrangement structure of the drive unit 5 of this embodiment, it has a rear wall portion 9c extending downward from the rear end portion 9e of the inclined portion 9b, and the lower end portion 9f of the rear wall portion 9c is located below the breather opening 8e.

[0072] This allows the airflow W1 flowing 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 9c and flow downward. As a result, airflow W2 (see Figure 2(a)) can flow through the gap S4 between the rear wall section 9c and the drive case 8, which can more effectively improve the ventilation around the breather opening 8e and thus more effectively improve the breather performance.

[0073] In this embodiment, the breather opening 8e is formed in front of the rear end 9e of the inclined portion 9b, but as shown in Figure 2(b), the breather opening 8f may be formed at the upper rear end 8b of the drive case 8.

[0074] In this case, the breather port 8f can be formed at the highest position on the drive case 8, which can more effectively improve breather performance. In addition, when the vehicle 1 is submerged in water, it is possible to more effectively prevent water from entering the inside of the drive case 8 through the breather port 8f.

[0075] 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]

[0076] 1 vehicle 3 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) 8d Rear (part of the case) 8e Breather outlet 9 Floor Panels 9b Inclined section 9c Rear wall 9d Front end (lower end of the inclined section) 9e Rear end (rear end of the inclined section) 9f Lower end (lower end of rear wall) 10 Front mounting device (mounting device) 30 Virtual horizontal plane 31 Space section

Claims

1. It has a drive unit located below the floor panel, The drive unit comprises a rotating electric machine, a power control device provided on the upper part of 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, wherein the drive unit is arranged in a forward-tilting position such that the upper front end of the case is located below the upper rear end of the case. The upper surface of the case is formed as an inclined surface that slopes upward from the upper front end to the upper rear end. The floor panel is inclined in the vertical direction, facing the upper surface of the case and along the upper surface of the case, and has an inclined portion at its rear end that is located at the highest position within the floor panel. A portion of the case is contained within the space enclosed by the virtual horizontal plane passing through the lower end of the inclined portion and the inclined portion itself. The drive device arrangement structure is characterized in that a breather port is formed in a part of the case, which connects the inside and outside of the case.

2. The floor panel has a rear wall portion that extends downward from the rear end of the inclined portion, The drive device arrangement structure according to claim 1, characterized in that the lower end of the rear wall portion is located below the breather opening.

3. A cross member positioned in front of the aforementioned drive unit and extending in the vehicle width direction, The drive unit has a mounting device that elastically supports the cross member, The drive device is arranged in a forward-tilting manner 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, as described in claim 1 or 2.

Images