SUMP guard for vehicle

Abstract

An assembly comprising an electric drive unit (4) for an electric vehicle (2) and a sump guard (12) mounted to the electric drive unit (4) is provided. The sump guard (12) is mounted to the electric drive unit (4) by a plurality of mounting arrangements (18) and comprises a plate body (16) which defines at least part of an underside surface of the electric vehicle (2) when the assembly is arranged for use. The sump guard (12) further comprises an arrangement of elongate ribs (28) provided on the plate body (16).

Description

[0001] SUMP GUARD FOR VEHICLE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a sump guard for a vehicle. Aspects of the invention relate to a sump guard, and an assembly comprising the sump guard.

[0004] BACKGROUND

[0005] In the design of electric vehicles, it is desirable to maximise the space available for passengers within the vehicle cabin. Lowering the position of the electric drive unit (EDU) is one way of providing more cabin space, but doing so without reducing the ground clearance of the vehicle is challenging. The underside of the EDU must be protected from the road and, typically, an undertray coupled to the vehicle frame would provide the required protection. Therefore, in a typical arrangement, the undertray position defines the lowest possible position for the EDU.

[0006] It is against this background that the present invention has been devised.

[0007] SUMMARY OF THE INVENTION

[0008] Aspects and embodiments of the invention provide a sump guard for an electric vehicle, an assembly comprising the sump guard, and a vehicle as claimed in the appended claims.

[0009] According to an aspect of the invention, an assembly comprising an electric drive unit (EDU) for an electric vehicle, and a sump guard mounted to the electric drive unit by a plurality of mounting arrangements is provided. According to another aspect of the invention, a vehicle comprising the assembly is provided. The sump guard comprises a plate body which defines at least part of an underside surface of the electric vehicle when the assembly is arranged for use. The sump guard further comprises an arrangement of elongate ribs provided in I on the plate body. The arrangement of elongate ribs may include one or more ribs which extend perpendicular to a fore-aft axis of the electric vehicle when the assembly is arranged for use. These ribs serve to stiffen the sump guard so that various benefits may be simultaneously realised, namely improved impact resistance and improved noise, vibration and harshness (NVH) performance. The sump guard may be made from cast metal, such as aluminium.

[0010] To further improve NVH performance, each mounting arrangement may comprise a rubber bushing arranged between the EDU and the sump guard. Additionally or alternatively, the sump guard may further comprise a foam panel coupled to a surface of the plate body which faces the EDU.

[0011] The sump guard may comprise a ramped surface which extends from the plate body to a forward edge such that the ramped surface is angled towards the electric drive unit. The sump guard defines the forward edge (i.e. an edge which is foremost along the fore-aft axis) when the assembly is arranged for use. In embodiments with a ramped surface, the sump guard may further comprise one or more support ribs which extend between the plate body and the ramped surface to support the ramped surface. According to another aspect of the invention, a sump guard for an electric vehicle is provided. The sump guard comprises a plate body and an arrangement of elongate ribs provided in I on the plate body. The arrangement of elongate ribs may be provided integrally with the plate body or affixed to the plate body and may be provided on a central portion of the plate body. For example, the arrangement of elongate ribs may be defined by an arrangement of debossed plate portions in the plate body. The sump guard further comprises a plurality of mounting members for fixing the plate body to an electric drive unit of the vehicle so that the plate body defines an underside surface of the vehicle.

[0012] In embodiments, the arrangement of elongate ribs may comprise one or more ribs extending in a first direction, and one or more ribs extending in a second direction perpendicular to the first direction. Alternatively or additionally, the elongate ribs may be provided in a grid pattern arrangement to define rectangular plate portions therebetween. Such a grid pattern may extend over a majority of the plate body, for example, each plate portion may have a maximum dimension of between 30 and 90mm.

[0013] Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner.

[0014] BRIEF DESCRIPTION OF THE DRAWINGS

[0015] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0016] Figure 1 shows a schematic view of a vehicle according to an embodiment of the invention;

[0017] Figure 2 shows a perspective view of an assembly according to an embodiment of the invention;

[0018] Figure 3 shows a perspective view of a sump guard according to an embodiment of the invention;

[0019] Figure 4 shows a plan view of the underside of the sump guard shown in Figure 3;

[0020] Figure 5 shows a cross-sectional view of the sump guard shown in Figures 3 and 4;

[0021] Figure 6 shows a cross-sectional view of a mounting member of the sump guard shown Figures 3 to 5.

[0022] DETAILED DESCRIPTION

[0023] In general terms, embodiments of the invention provide an assembly comprising a sump guard coupled directly to an electric drive unit (EDU) of a vehicle. The sump guard is configured to be a structural component which protects the EDU from under vehicle impact. Thus, the sump guard can replace the region of the protective vehicle undertray that would typically extend beneath the EDU and define an underside surface of the vehicle. As a result, the EDU can be packaged in a lower position within the vehicle such that the sump guard is flush with vehicle undertray. In this way, the available cabin space can be increased while maintaining the same ground clearance for the vehicle. However, since the sump guard is coupled to the EDU, vibrations from the EDU may cause the sump guard to vibrate. Therefore, the sump guard is configured to be sufficiently stiff so as not to be a source of excessive noise, vibration and harshness (NVH) to passengers in the cabin.

[0024] So that the sump guard simultaneously meets the desired structural and NVH requirements, it is provided with an arrangement of elongate ribs which serve to stiffen and strengthen the sump guard, without adding excessive weight to the component.

[0025] To provide context for the invention, Figure 1 shows a schematic view of a vehicle 2, specifically an electric vehicle. The vehicle 2 comprises an electric drive unit (EDU) 4 which is configured to convert energy from a vehicle battery 6 into mechanical power to drive the wheels 8. The EDU 4 shown is a ‘rear’ EDU and is arranged between the two rear wheels 8 of the vehicle 2. The vehicle 2 may alternatively or additionally comprises a ‘front’ EDU arranged towards the front end of the vehicle 2. Arrow X indicates the forward direction, or a fore-aft axis of the vehicle.

[0026] A sump 10 is provided underneath the EDU 4 for collecting excess fluid (such as oil) as it circulates through the EDU 4. A sump guard 12 is provided underneath the sump 10 to protect the sump 10 from debris and from impact from the road. As shown, the sump guard 12 is coupled to the EDU 4 and defines an underside surface of the vehicle underneath the EDU 4. The vehicle further comprises an undertray 14 which defines another underside surface of the vehicle 2 away from the region underneath the EDU 4. The assembly of the EDU 4 and the sump guard 12 are mounted in the vehicle 2 so that the sump guard 12 is substantially flush with the undertray 14, i.e. so that the ground clearance underneath the EDU (between the ground 17 and the sump guard 12) is at least as high as the clearance between the ground 17 and the undertray 14.

[0027] Figure 2 shows an assembly according to an embodiment of the invention. The assembly comprises the EDU 4 and the sump guard 12 discussed above with reference to Figure 1 . The EDU comprises mounting points 11 for mounting the EDU to the vehicle. The sump guard 12 comprises a plate body 16 which is mounted to the EDU 4 by a plurality of mounting arrangements 18. In this example, the plate body 16 is generally rectangular and is mounted to the EDU 4 at each corner by a mounting arrangement 18 such that there are four mounting arrangements 18 in total. The mounting arrangements 18 are configured to position the sump guard 12 away from the EDU 4 to define a space 20 therebetween within which the vehicle sump 10 can be installed. The sump 10 is not shown in Figure 2 so that the features of the sump guard 12 can be more clearly seen. The mounting arrangements 18 themselves will be discussed in more detail below with reference to Figure 6.

[0028] When the assembly is arranged for use, the plate body 16 defines at least part of an underside surface of the vehicle 2 so as to protect the sump 10 and the EDU 4 from road debris and impact. In this example, the sump guard 12 is made from cast metal, specifically cast aluminium, so that it can resist block strike impacts (e.g. from large rocks when driving off-road). Accordingly, the sump guard 12 shields the sump structure 10 from impact. The side of the plate body 16 which faces the ground when the sump guard is arranged for use may be referred to as the outward facing side of the plate body 16. The opposite side, which faces towards the EDU 4 when the sump guard 12 is arranged for use, may be referred to as the inward facing side of the plate body 16.

[0029] As mentioned, the plate body 16 is generally rectangular and defines a forward edge 22 which is foremost, and a rear edge 24 which is rearmost, having regard to the fore-aft axis of the vehicle when the sump guard 12 is arranged for use (See Figure 4). The forward and rear edges 22, 24 are substantially parallel to each other and are substantially perpendicular to the fore-aft axis of the vehicle when the sump guard 12 is arranged for use. The plate body 16 defines side edges 26 which extend generally in a direction parallel to the fore-aft axis between the forward and rear edges 22, 24.

[0030] Turning to Figures 3 and 4, which show perspective and bottom up views of the sump guard 12 respectively, the sump guard 12 further comprises an arrangement of elongate ribs 28 provided on the plate body 16. As shown, the arrangement of elongate ribs 28 includes a plurality of straight ribs which extend between the forward and rear edges 22, 24 of the plate body 16 in a direction which is substantially parallel to the fore-aft axis of the vehicle 2 when the assembly is arranged for use. These elongate ribs may herein be referred to as longitudinal ribs 28’ and each one extends from a rear end 30 to a forward end 32. The arrangement of elongate ribs 28 further includes a plurality of straight ribs which extend between the side edges 26 of the plate body 16 in a direction which is substantially perpendicular to the fore-aft axis of the vehicle 2 when the assembly is arranged for use. These elongate ribs may herein be referred to as lateral ribs 28” and each one extends from a nearside end 34 to an offside end 36. In more general terms, the arrangement of elongate ribs 28 includes one or more ribs 28’ extending in a first direction (X) and one or more ribs 28” extending in a second direction (Y) perpendicular to the first direction (X).

[0031] In the example shown, the arrangement comprises a series of four longitudinal ribs 28’ and a series of two lateral ribs 28”. The longitudinal ribs 28’ are arranged aligned and spaced apart from each other between the side edges 26 of the plate body 16, while the lateral ribs 28” are arranged aligned and spaced apart from each other between the forward and rear edges 22, 24 of the plate body 16. The longitudinal and lateral ribs 28’, 28” overlap with each other to provide a grid pattern arrangement of ribs 28. That is to say, each of the lateral ribs 28” intersects each of the longitudinal ribs 28’ at respective intersection regions 38 so that there are eight intersection regions 38 in total.

[0032] As best seen in Figure 3, the grid pattern of ribs 28 defines an array of substantially rectangular plate portions 40 between adjacent ribs 28. Other examples may comprise more of fewer of each of the described longitudinal and lateral ribs 28’, 28” and some examples may comprise only longitudinal or lateral ribs 28’, 28”.

[0033] In this example, the longitudinal ribs 28’ are equidistantly spaced apart from each other to define substantially rectangular plate portions 40 therebetween having a width, W, in the lateral direction. The pair of lateral ribs 28” are symmetrically spaced apart along the length of the longitudinal ribs 28’ to thereby divide the plate portions between the longitudinal ribs 28’ into three so that each plate portion has a length, L. As such, the grid pattern arrangement of ribs 28 defines 15 rectangular plate portions 40 arranged in a grid of three by five. The lateral ribs 28” are closer to the ends 30, 32 of the longitudinal ribs 28’ than to each other so that plate portions between the two lateral ribs 28” (central plate portions 40’) are longer than the plate portions defined between the lateral ribs and the ends of the longitudinal ribs (end portions 40”). In this example, the longitudinal ribs 28’ are spaced apart to define plate portions 40 that are 15 to 25 mm wide, specifically 20mm. The lateral ribs 28” are positioned to define central plate portions 40’ that are 55 to 85 mm long, specifically 60 mm.

[0034] The grid of elongate ribs 28 is positioned substantially centrally in I on the plate body 16 so that the distance between the ends of the ribs 28 and the edges 22, 24, 26 of the plate body 16 is generally constant around the grid arrangement. In other words, the arrangement of elongate ribs 28 is provided on a central portion of the plate body 16. The regions between the grid arrangement of ribs 28 and the edges 22, 24, 26 of the plate body 16 may be referred to as edge regions 42. In this example, the grid pattern extends over a majority of the plate body 16 such that each longitudinal rib 28’ extends more than halfway between the forward and rear edges 22, 24 and each lateral rib 28” extends more than halfway between the side edges 26.

[0035] In examples of the sump guard 12, the ribs 28 may take the form of beams which are coupled to the plate body 16. For example, the beams may be welded along their length to the outward or inner facing sides of the plate body 16. However, in the example shown, the ribs 28 are formed integrally with the plate body 16. Figure 5 shows a cross-sectional view of the sump guard 12 and, as shown, the ribs 28 are defined by the plate portions 40 being debossed in the plate body 16.

[0036] In more detail, the plate body 16 has a varied thickness between the inward and outward facing sides 44, 46 so as to define the ribs 28 which have a greater thickness than the plate portions 40. In other words, the ribs 28 are thicker in the Y-direction than the plate portions 40 defined between the ribs 28. As shown, the plate portions 40 are debossed inwardly (i.e. towards the EDU 4 when the sump guard 12 is arranged for use) so that the ribs 28 do not project outwardly beyond the edge portions 42 of the plate body 16. In this example, the plate body 16 and the edge regions 42 are the same thickness, meaning that the transition 48 from edge portion 42 to debossed plate portion 40 effectively defines a region of increased thickness which acts as a rib 28. The edge regions 42 and debossed plate portions 40 are generally 5mm thick (in the Y-direction), while the ribs 28 and the transition 48 between edge region 42 and plate portion 40 have a maximum dimension in the Y-direction of 10mm. As shown, the transitions between the debossed plate portions 40 and the adjacent ribs 28 and edge regions 42 are radiused so as to avoid sharp corners in the cross section which could lead to stress concentrations in use.

[0037] As will be appreciated, the longitudinal ribs 28’ serve to increase the bending stiffness of the sump guard 12 in the fore-aft (longitudinal) direction. As a result, the sump guard 12 is more able to resist structural loads experienced during a block strike that might occur as the vehicle 2 moves. This improved stiffness performance allows the sump guard 12 to transfer block strike loads through the mounting arrangements 18 to the EDU mount points 11 which couple the EDU 4 to the vehicle frame. In turn, this means that the sump guard 12 is particularly suited for protecting the sump 10 and the EDU 4 against block strikes. Furthermore, since the ribs 28 extend lower than the debossed plate portions 40 (having regard to the orientation of the sump guard 12 when arranged for use) it is more likely that any block strike and I or road debris would first impact against the ribs 28, as opposed to against the thinner debossed plate portions 40. Due to their greater thickness, the ribs 28 more resistant to impact loads and are therefore less likely to be punctured. Hence, the ribs 28 further act to protect the thinner debossed plate portions 40 from impact and, as such, the overall impact resistance of the sump guard 12 is improved.

[0038] Meanwhile, the lateral ribs 28” serve to stiffen the sump guard 12 in the side-to-side (lateral) direction. As a result, the sump guard 12 is less susceptible to flexing in the lateral direction as the attached EDU 4 moves and vibrates in use. The overall increased stiffness provided to the plate body 16 by the grid pattern arrangement of elongate ribs 28 means the sump guard 12 is more able to resist movement and vibrations from the attached EDU 4. As a result, the noise, vibration and harshness (NVH) produced by the sump guard 12 is reduced, compared to if there were no elongate ribs 28, or only longitudinal elongate ribs 28’.

[0039] Of course, increased stiffness provided by the longitudinal ribs 28’ will also contribute to improving the NVH performance of the sump guard 12, while increased stiffness provided by the lateral ribs 28” will also contribute to improving the structural performance of the sump guard 12. Thus, as will be understood, the arrangement of elongate ribs 28 provided on the plate body simultaneously improves the structural and NVH performance of the sump guard.

[0040] As best seen in Figure 3, plate body 16 comprises a ramped surface 49 which extends to the forward edge 22 in the direction of the fore-aft axis (X) such that the ramped portion 49 is angled away from the ground 17 (with the forward edge 22 higher than rear edge 24) the when the sump guard 12 is arranged for use. In other words, the sump guard 12 comprises a ramped portion 49 which extends from the plate body 16 to the forward edge 22 such that the ramped portion 49 is angled towards the EDU 4. The sump guard 12 further comprises a series of ribs 51 (five in this example) which extend between the plate body 16 and the ramped portion 49 to provide structural support to the ramped portion 49. Each support rib 51 extends in the direction of the fore- aft axis (X). The ramped portion 49 serves to deflect (or guide) the assembly over smaller rocks and obstacles as the vehicle drives in a forward direction.

[0041] Turning now to Figure 6, a cross-sectional view of one of the mounting arrangements 18 is shown. As can be seen, the mounting arrangement 18 comprises a mounting member 50, a metal bushing 52, and a rubber bushing (or grommet) 54 for NVH dampening. The mounting member 50 extends upwardly away from the plate body 16 towards the EDU 4 to define a flange 56 for mating against a corresponding mounting region (not shown) of the EDU 4. An aperture 58 for receiving the bushing 52 and the grommet 54 extends through the flange 56.

[0042] The grommet 54 comprises a tubular shaft 60 and an annular flange 62’, 62” at arranged at each end of the shaft 60. The grommet 54 is configured so that, when inserted into the aperture 58 in the mounting member 50, the shaft 60 fits tightly against the aperture 58 and the opposing annular flanges 62’, 62” fit tightly on either side of the mounting member flange 56. One of the annular flanges 62” comprises an angled surface 64 which allows for the grommet 54 to be more easily inserted into the aperture 58.

[0043] Similarly, the bushing 52 is arranged to be inserted into the tubular shaft 60 of the grommet. The bushing 52 comprises a tubular shaft 66 arranged for receiving a coupling member such as a bolt, and an annular flange 68 for abutting against the non-angled flange 62’ of the grommet 54. Thus, as shown, when the mounting member 50, grommet 54, and bushing 52 are arranged together, a flange 62’ of the grommet 54 is arranged between the mounting member flange 56 and the bushing flange 68 such that the mounting member 50 and the bushing 52 are isolated from each other. In general terms, each mounting arrangement 18 comprises a rubber bushing 54 arranged between the EDU 4 and the sump guard 12.

[0044] The grommet 54 is made from a rubber with shore hardness of 50 and, as such, is particularly suited for damping vibrations between the EDU 4 and the sump guard 12. Thus, the inclusion of rubber grommets 54 further improves the NVH performance of the sump guard 12 when coupled to the EDU 4.

[0045] To yet further improve NVH performance, the assembly further comprises a panel 70 of absorbent foam coupled to the inward facing side 44 of the sump guard 12. In other words, the sump guard 12 comprises a foam panel 70 coupled to a surface 44 of the plate body 16 which faces the EDU 4 when in use. This can be seen in Figures 2 and 5 and, as shown, the foam panel 70 is substantially rectangular and extends over a majority of the inward facing side 44 of the plate body 16.

[0046] It will be appreciated that various modifications may be made to the aforementioned embodiments without departing from the scope of the present application.

Claims

CLAIMS1 . An assembly comprising: an electric drive unit for an electric vehicle; and a sump guard mounted to the electric drive unit by a plurality of mounting arrangements, wherein: the sump guard comprises a plate body and an arrangement of elongate ribs provided on the plate body; and the plate body defines at least part of an underside surface of the electric vehicle when the assembly is arranged for use.

2. An assembly according to claim 1 , wherein the sump guard is made from cast metal.

3. An assembly according to any preceding claim, wherein the arrangement of elongate ribs includes one or more ribs which extend perpendicular to a fore-aft axis of the electric vehicle when the assembly is arranged for use.

4. An assembly according to any preceding claim, wherein each mounting arrangement comprises a rubber bushing arranged between the electric drive unit and the sump guard.

5. An assembly according to any preceding claim, wherein the sump guard comprises a foam panel coupled to a surface of the plate body which faces the electric drive unit.

6. An assembly according to any preceding claim, wherein the sump guard defines a forward edge when the assembly is arranged for use, and wherein the sump guard comprises: a ramped portion which extends from the plate body to the forward edge, wherein the ramped portion is angled towards the electric drive unit; and one or more support ribs extending between the plate body and the ramped portion.

7. A sump guard for an electric vehicle, wherein the sump guard comprises: a plate body; a plurality of mounting members for fixing the plate body to an electric drive unit of the vehicle so that the plate body defines an underside surface of the vehicle; and an arrangement of elongate ribs provided on the plate body.

8. A sump guard according to claim 7, wherein the arrangement of elongate ribs is provided on a central portion of the plate body.

9. A sump guard according to any preceding claim, wherein the arrangement of elongate ribs includes one or more ribs extending in a first direction; and one or more ribs extending in a second direction perpendicular to the first direction.

10. A sump guard according to any preceding claim, wherein the elongate ribs are provided in a grid pattern arrangement to define rectangular plate portions therebetween.

11. A sump guard according to claim , wherein the grid pattern extends over a majority of the plate body.

12. A sump guard according to claim 11 , wherein each plate portion has a maximum dimension of between 30 and 90mm.

13. A sump guard according to any preceding claim, wherein the arrangement of elongate ribs are provided integrally with the plate body.

14. A sump guard according to claim 13, wherein the arrangement of elongate ribs is defined by an arrangement of debossed plate portions in the plate body.

15. A vehicle comprising the assembly of claims 1 to 6 or a sump guard according to claims 7 to 14.

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