GB2440925A

GB2440925A - Vehicle engine air cooling and deflector

Info

Publication number: GB2440925A
Application number: GB0616341A
Authority: GB
Inventors: Gerry Christie
Original assignee: Nissan Motor Manufacturing UK Ltd
Current assignee: Nissan Motor Manufacturing UK Ltd
Priority date: 2006-08-17
Filing date: 2006-08-17
Publication date: 2008-02-20
Anticipated expiration: 2026-08-17
Also published as: GB0616341D0; GB2440925B

Abstract

The invention relates to a method of cooling a vehicle engine in a wind tunnel using airflow generated by the wind tunnel. The method comprises moving an engine compartment cover 13 of the vehicle to create an opening through which airflow may pass. A deflector 15 is positioned relative to the vehicle. Airflow is provided around the vehicle in the wind tunnel. The airflow is deflected by way of the deflector 15 toward the engine so as to cool the engine. The invention also relates to apparatus comprising a deflector 15 and a support. The deflector 15 is for deflecting the airflow toward the engine. The support is removably fixable to the vehicle for holding the deflector in a deflecting position relative to the vehicle. The deflector 15 may be attached to a bonnet support and may be mounted at an adjustable angle.

Description

VEHICLE ENGINE COOLING

Technical Field

The invention relates to a method of cooling a vehicle engine and cooling apparatus for cooling the vehicle engine. The invention is particularly, but not exclusively, intended for use in cooling vehicle engines between successive tests in a wind tunnel.

Introduction

Vehicle and vehicle component manufacturers often test vehicles in a wind tunnel in order to test the performance of vehicles and their components under various environmental conditions. These tests may, for example, be carried out to ensure compliance with various statutory standards or other durability criteria.

Some tests require a vehicle engine to start up from cold at very low ambient temperatures as low as, for example, minus 30 Celsius. However, as the engine may still be hot as a result of a previous test, it is necessary to allow the engine to cool in order for the next test to be carried out. Unfortunately, the engine can take several hours to cool to the required temperature.

The use of a wind tunnel is typically costed on the basis of the time taken to carry out a programme of tests because wind tunnels are expensive assets to maintain and to operate. Wind tunnel proprietors may hire out their wind tunnels to other users, even though they may use the tunnels for their own testing programmes. Also, there is pressure to minimise development timescales and to reduce manpower costs. So, for both a wind tunnel proprietor and a user it is advantageous to plan vehicle testing programmes so that each programme uses the wind tunnel for the shortest time possible.

The longest step in a testing programme is often cooling the engine between successive start up tests. Effective cooling cannot be achieved by using the internal cooling system of the vehicle because this requires the engine to be running.

Cooling to ambient temperature can be achieved by external means, such as blowing cold air at the vehicle engine. For example, in a wind tunnel, high-speed airflow can be directed at the front of the vehicle. However, this technique is ineffective because the engine is designed to be cooled by coolant flowing through the internal coolant system of the vehicle and not by an external airflow in isolation.

Figure 1 shows a typically densely-packed arrangement of components within a vehicle engine compartment of a vehicle 2. The arrangement of the components restricts the access for oncoming airflow to the hottest parts of the engine 1, notably the engine block. In this case airflow would be prevented from reaching the engine block by components such as the radiator 3, cross-member 5 and exhaust manifold 7 located between the engine block and the front of the vehicle 2.

In addition the engine compartment may be equipped with baffles and deflectors which inhibit external airflow from cooling the engine 1 effectively. For example, the engine compartment may have a shield underneath to protect the engine from damage, to reduce the emission of engine noise, and/or to improve the aerodynamic performance of the vehicle.

Raising or removing the vehicle bonnet or hood may help the oncoming airflow to access the engine, but these solutions have problems of their own.

To secure the raised bonnet in position, the bonnet is typically propped with a bonnet support 9. The bonnet support 9 is not designed to support the bonnet in high-speed airflow necessary to achieve effective cooling. So, in high-speed airflow characteristic of wind tunnels, the bonnet may be torn off or otherwise damaged by the force applied to it by the airflow.

Removing the bonnet is time-consuming because it may have to be replaced for other tests of the testing programme. Also, removal of the bonnet allows much of the airflow to flow over the top of the engine rather than around the engine.

The invention resides in a deflector arrangement that is held securely to a vehicle in airflow.

Statements of Invention

According to a first aspect of the invention there is provided a method of cooling a vehicle engine in a wind tunnel using airflow generated by the wind tunnel. The method comprises moving an engine compartment cover of the vehicle to create an opening through which airflow may pass. A deflector is positioned relative to the vehicle. Airflow is provided around the vehicle in the wind tunnel, and is deflected by way of the deflector toward the engine so as to cool the engine.

The method advantageously deflects airflow past the various components of the engine, especially the engine block. Thus the rate of cooling is increased to achieve a required ambient temperature of the engine as quickly as possible, for example for the next test in a wind tunnel testing programme. Furthermore, the deflector is fixed to the vehicle in a manner that prevents the deflector and/or the bonnet from being ripped off the vehicle or otherwise damaged.

In a second aspect the inventive concept extends to a cooling apparatus for cooling a vehicle engine in a wind tunnel using airflow generated by the wind tunnel. The apparatus comprises a deflector and a support. The deflector is for deflecting the airflow toward the engine. The support is removably fixable to the vehicle for holding the deflector in a deflecting position relative to the vehicle.

Further optional features of the invention are set out in the appended claims.

Drawings Preferred embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is an elevated perspective view of a vehicle engine compartment showing the arrangement of the engine components and ancillaries; Figure 2 is front perspective view of a vehicle with cooling apparatus according to the present invention fitted by way of a connection to a bonnet catch and a loop, and showing the components of the apparatus including a strut and a deflector; Figure 3 is a side perspective view of the vehicle fitted with the cooling apparatus as shown in Figure 2; Figure 4 is an enlarged upward perspective view of the connection of the strut to the loop as shown in Figure 2; Figure 5 is an enlarged downward perspective view of a connection of the strut to the bonnet catch as shown in Figure 2; Figure 6 is an exploded side perspective view of a part of the strut shown in Figure 2 and a joint for securing the strut to the deflector of the apparatus shown in Figure 2; Figure 7 is an expanded side perspective representation of an improvement to the deflector shown in Figure 2 and of a part of the joint shown in Figure 6; and Figure 8 is a front perspective view of a second embodiment of cooling apparatus according to the present invention, the cooling apparatus being fitted to a loop and a bonnet catch of a vehicle.

Detailed description

Cooling Apparatus Referring to Figure 2, cooling apparatus 25 is shown secured to the vehicle 2. The apparatus 25 is configured to interface with the standard features of a bonnet closure mechanism. Such a mechanism typically comprises a bonnet latch 19 mounted on a cross-member 5 and a ioop 21 mounted on the underside surface of the bonnet 13.

The bonnet 13 is otherwise supported by rearward hinges 20. When closed, the bonnet 13 lies over the engine compartment defmed by a peripheral vehicle body structure 27 extending around the engine, the latch 19 and the loop 21 which engages to secure the front of the bonnet 13 to the cross-member 5.

The cooling apparatus has a deflector 15 connected to a strut 17 by a joint 18. The strut 17 is connected at one end to the bonnet latch 19 on the cross-member 5 and at its other end to the loop 21 located toward the front of the underside surface of the bonnet 13.

The Deflector The deflector 15 is generally oblong and is pivotally secured to the strut 17 substantially at the midpoint of long front edge 16 of the deflector 15. The front edge 16 is orthogonal to the direction of airflow, in use. With half of the deflector 15 positioned either side of the strut 17 the forces applied by oncoming airflow to each half of a forward surface 23 of the deflector 15 are substantially equal. If there is any significant imbalance in those forces side-to-side, the deflector 15 can move at the joint 18 about the strut 17 so as to self-steer in the airflow. The strut 17 can flex in torsion for this purpose.

The deflector 15 is inclined downwardly toward the rear of the engine 1. In high-speed airflow directed toward the front of the vehicle 2, the deflector 15 deflects airflow downwards towards the engine 1, whilst the deflector 15 is fixed to the vehicle 2. So, deflection of airflow by the deflector 15 increases airflow around the engine 1 enabling the engine 1 to be cooled quickly.

The joint 18 between the deflector 15 and the strut 17 is adjustable so that the angle of the deflector 15 with respect to the strut 17. Furthermore, as a result of the screw-thread that extends along the entire length of the strut 17, the position of the joint 18 along the strut 17, can be altered. As shown in Figure 2, but more clearly in Figure 3, the deflector 15 is angled with respect to the strut 17 so that the deflector 15 is broadly parallel to the raised bonnet 13. However, the skilled man would understand that the angle of the deflector 15 will be selected so as to optimise airflow over the engine 1.

The angle may differ from the angle of the bonnet, depending on the size of the engine. Note also that the joint 18 is located in a different position on the strut 17 in Figure 3 from Figure 2. Thus, by positioning the joint 18 along the strut 17 and selecting the angle of the deflector 15 with respect to the strut 17, the depth of the deflector 15 can be adjusted to match a gap defined between the peripheral vehicle body structure 27 and the raised bonnet 13. By making these adjustments, the deflector 15 can be adjusted to optimise the deflection of airflow around the engine 1 and the consequential cooling.

Loop Connection Referring to Figure 4, the loop 21 is shown engaged with a loop connection 29 secured to an upper end 37 of the strut 17. The loop connection 29 is connected to the strut 17 by means of a eyelet 30 formed in the upper end 37 of the strut 17 The eyelet is either welded to the upper end 37 of the strut 17 or is formed integrally therewith.

The loop connection 29 is a carabiner type connection comprising a rigid hook 31 and a latch 33 pivotally and resiliently biased to engage a tip 35 of the hook 31. Thus, the loop connection 29 is readily snap-fitted to the ioop 21 by aligning the latch 33 with the loop 21. The loop 21 is forced against the bias of the latch 33 so that latch 33 pivots away from contact with the tip 35, admits the loop 21 into engagement with the hook 31 and snaps closed behind. The loop connection 29 has a lock 39 to secure the latch 33 to the tip 35, so preventing the loop connection 29 from disengaging from the loop 21 during use.

To detach the loop connection 29 from the loop 21, the lock 39 is released. The latch 33 is then moved away from the tip 35 so far as to free the ioop 21 from the hook 31.

The loop connection 29 may then be removed from the loop 21.

Bonnet Latch Connection Referring to Figure 5, the bonnet latch 19 is shown engaged with a latch connection 43 that forms part of a lower connector 42 which is, in turn, pivotally attached to a lower end 45 of the strut 17.

The latch connection 43 has a similar loop shape to the loop 21, and it is designed to engage the bonnet latch 19 in a manner similar to the loop 21. The latch connetion 43 is placed above the bonnet latch 19. The strut 17 is then forced downwards to open the bonnet latch 19, so that the latch connection 43 passes downwards between inwardly-biased jaws of the bonnet latch 19. Once the latch connection 43 has passed the jaws of the bonnet latch 19, the jaws snap back inwardly under their bias to lock and to engage the latch connection 43.

The strut 17 is thus securable to the vehicle 2 so that the strut 17 can hold the position of the deflector 15 relative to the vehicle 2 in the airflow so as to deflect the airflow to the engine 1. The strut 17 also supports the bonnet 13 of the vehicle 2 to prevent damage in high speed airflow; the shielding effect of the deflector 15 also assists in that regard. The cooling apparatus 25 thereby solves the problem of using the bonnet 13 of the vehicle 2 in an attempt to deflect airflow towards the engine 1, risking damage to the bonnet 13 or the vehicle 2 as a whole.

Connection Mechanism to Strut Figure 6 shows the joint 18 that secures the deflector 15 to the strut 17. The joint 18 has a cuboidal block 47 and a deflector bracket 48 co-operable with the block 47. The block 47 has a threaded vertical strut passageway 49 passing between apertures 51, one of which is defined in each of an upper surface 53 and a lower surface 55 of the block 47, toward its front face 56. The thread of the internal surface of the strut passageway 49 is complementary to the screw-thread provided along the entire length of the strut 17 thus enabling adjustment of the position of the joint 18 along the length of the strut 17.

The block 47 has a hinge passageway 57 that extends between apertures 52, one of which is defined in each of the side faces 59 of the block 47, toward its rear surface 61. The hinge passageway 57 has a central longitudinal axis that lies orthogonal to the plane containing the central longitudinal axis of the strut passageway 49. Three pin passageways 63 are proximate to the hinge passageway 57, angularly spaced about the central longitudinal axis of the hinge passageway 57 with a common radial distance from that axis.

The bracket 48 is generally U-shaped in plan. The base of the U has an attachment 64 for attaching to the deflector 15 and the arms 65 of the U lie in parallel planes. The anns 65 are spaced so that they tightly fit around the side faces 59 of the block 47. A bolt aperture 67 and a pin aperture 69 are defined in each arm 65. When the bracket 48 is fitted to the block 47, the bolt apertures 67 can be aligned with the hinge passageway 57. The hinge passageway 57 and the bolt apertures 67 are each dimensioned to accept a shaft 71 of a bolt 73 so that the bracket 48 can be secured to the block 47 by a nut engaged with the bolt 73. By adjusting the tightness with which the bracket 48 is held to the block 47 by the bolt 73, the bracket 48 can be pivoted with respect to block 47 about the bolt shaft 71 and then held in a desired position.

Each pin aperture 69 is spaced apart from the central axis of the adjacent bolt aperture 67 by the same distance as each pin passageway 63 is spaced apart from the central longitudinal axis of the hinge passageway 57. Therefore, on pivoting of the bracket 48 relative to the block 47 about the rotational axis of the bolt shaft 71, the pin apertures 69 can be aligned with a selected one of the three pin passageways 63. The angular position of the attachment 64 (and thus an attached deflector 15) relative to the block 47 (and thus the strut 17) can be fixed by passing a lockable pin 75 through the pin apertures 69 and the selected one of the pin passageways 63. This provides greater security than relying upon the nut and bolt 73 alone to hold the angular position of the deflector 15.

When the deflector 15 deflects high-speed airflow, the airflow applies an upward force to the deflector 15. The upward force is transmitted to the block 47 so as to urge the surface of the strut passageway 49 against the strut 17. In consequence, the block 47 is additionally secured to the strut 17 by the provision of a pair of lock nuts (not shown) threaded onto the strut 17 on either side of the joint 18 to prevent movement of the joint 18 relative to the strut 17.

The joint 18 thus enables the angle of deflection of airflow to the engine I to be adjusted to optimise cooling of the engines of different vehicle designs and under different airflow conditions.

Connection Mechanism to Deflector In Figure 7 the bracket 48 is shown secured to the deflector 15. All features present in Figure 6 that are shown in Figure 7 take the same reference numbers. The deflector 15 has a planar oblong plate 77 with oblong side plates 79 that are orthogonal to the plane of the plate 77 and hence parallel to each other. The side plates 79 are each directed generally downwards so that in use they point towards the vehicle engine 2.

The planar plate 77 is secured by the attachment 64 to the bracket 48 midway between the two side plates 79. By virtue of the side plates 79, the deflector 15 is a more efficient airflow scoop than a deflector without side plates 79. Moreover, the side plates 79 help to improve the stability of the deflector 15 in high speed airflow.

Two adjustable sidepieces 81 (only one of which is shown) are attached one to each side of the planar plate 77 above the side plates 79. Each sidepiece 81 has a body plate 83 substantially parallel with the planar plate 77 and a side panel 85 orthogonal to the planar plate 77 and substantially parallel to the side plates 79. The body plates 83 each have three parallel lateral slots 87. Through each slot 87 extends a bolt 89 to which a nut 91 may be secured. The bolts 89 extend through holes in the planar plate 77 spaced to match the spacing between the slots 87. Thus, by slackening and tightening the nuts 91, the sidepieces 81 can be moved laterally and fixed in position relative to the planar plate 79 so as to widen or narrow the deflector 15. The deflector 15 is therefore further adjustable to optimise the deflection of airflow by the deflector 15 to suit different vehicles and different speeds of airflow.

Method of ODeration To fit the cooling apparatus 25 to the vehicle 1, the bonnet 13 is released by operating the release mechanism to disengage the ioop 21 from the bonnet latch 19. The bonnet 13 is then raised. The cooling apparatus 25 is then adjusted if necessary before fitting to the vehicle 2. The angle of the deflector 15 with respect to the strut 17 is selected by inserting the lockable pin 75 through one of the three pin passageways 63 and through the pin apertures 69. The elevation of the deflector 15 relative to the engine 2 (once fitted) is selected by adjusting the joint 18 to the required position along the strut 17.

The latch connection 43 is then placed on, and forced down on to, the bonnet latch 19 so that the bonnet latch 19 engages the latch connection 43. Then the loop connection 29 is engaged with the ioop 21 so that the bonnet 13 is secured in its raised position.

The deflector 15 is now in position to deflect airflow toward the engine 1.

When the vehicle 2 is in a wind tunnel (not shown), the wind tunnel is used to generate airflow around the vehicle 2. The deflector 15 deflects part of the airflow towards the engine 2 so that the engine 2 cools quickly to the required temperature.

The various adjustable parts of the cooling apparatus 25 can be further adjusted to optimise the cooling of the engine 2. In particular, the gap between the back of the deflector 15 and the engine block can be minimised in order to prevent the wind from spilling over the windscreen rather than passing through the engine. In a programme of tests, in which the engine is required to be at a specific ambient temperature for each test, this method of cooling is used prior to each successive test.

Variations and Modifications Having described the preferred embodiment of the present invention, it is to be appreciated that the embodiment in question is exemplary only and that variations and modifications, such as will occur to those possessed of the appropriate knowledge and skills, may be made without departure from the scope of the invention as set forth in the appended claims.

Improvement of Figure 7 Note that the bracket 48 shown in Figure 7 is an improved version of the bracket 48 shown in Figure 6 because each arm 65 has two extra pin apertures 69. These extra pin apertures 69 enable the bracket 48, and thus an attached deflector 15, to be locked in additional angular positions relative to the block 47.

Other Embodiment Figure 8 shows another embodiment of cooling apparatus 25a according to the invention. The cooling apparatus 25a has several features in common with the cooling apparatus 25 of the previous embodiment shown in Figures 2 to 7 and takes the same reference numbers to that extent. In the embodiment of Figure 8 the various previously adjustable parts of the cooling apparatus 25a are fixed so that the apparatus is optimised for use with a particular type of vehicle in certain types of airflow. The deflector 15 is welded to the strut 17. So, the angle of the deflector 15 relative to the strut 17 and the position of the deflector 15 along the strut 17 are both fixed. The deflector 15 does not have adjustable side panels 83 and the side plates 79 are not orthogonal to the planar plate 77. Instead the deflector 15 has triangular side plates 79 that extend the length of the deflector 15 and are obtusely angled with respect to the planar plate 77 so as to scoop the airflow towards the engine 2.

In variants of the preferred embodiment, particular features of the cooling apparatus may be fixed whilst others are adjustable.

In variants of the aforementioned embodiments, the bonnet 13 can be removed. In these variants, a cooling apparatus including a deflector may, for example, be fixed to anchoring points on the vehicle structure within the engine compartment, such as the strut towers of the front suspension.

Claims

CLAIMS

1. A method of cooling a vehicle engine in a wind tunnel using airflow generated by the wind tunnel, the method comprising: moving an engine compartment cover of the vehicle to create an opening through which airflow may pass; positioning a deflector relative to the vehicle; providing airflow around the vehicle in the wind tunnel; and by way of the deflector, deflecting the airflow toward the engine so as to cool the engine.

2. The method of Claim 1, comprising deflecting airflow by way of the deflector through the opening and then onto the engine.

3. The method of Claim 1 or Claim 2, wherein moving is raising the engine compartment cover.

4. The method of Claim 3, comprising securing the deflector to the raised cover.

5. The method of Claim 4, comprising securing the deflector to a vehicle structure that normally supports the cover when lowered.

6. The method of Claim 5, the structure being a cross-member having a latch co-operable with the cover when the cover is lowered, wherein the method comprises attaching the deflector to the cross-member by engagement with the latch when the cover is raised.

7. The method of any of Claims 5 or Claim 6, comprising adjusting the depth of deflector to match a gap defined between the vehicle structure and the raised cover.

8. The method of any preceding Claim, comprising adjusting the angle of incidence of the deflector with respect to the airflow.

9. The method of any preceding Claim, comprising adjusting the width of the deflector.

10. Cooling apparatus for cooling a vehicle engine in a wind tunnel using airflow generated by the wind tunnel, wherein the apparatus comprises: a deflector for deflecting the airflow toward the engine and a support removably fixable to the vehicle for holding the deflector in a deflecting position relative to the vehicle.

11. A cooling apparatus of Claim 10, wherein the support comprises a strut to be secured between a raised engine compartment cover and a vehicle structure that supports the cover when lowered.

12. A cooling apparatus of Claim 11, wherein the strut has means engageable with an engine compartment cover at one end and means engageable with a latch for the cover at another end.

13. A cooling apparatus of any of Claims 10 to 12, wherein the deflector is pivotable with respect to the support.

14. A cooling apparatus of any of Claims 10 to 13, wherein the deflector comprises a deflector plate and side plates, one each side of the deflector plate.

15. A cooling apparatus of Claim 14, wherein the side plates are orthogonal to the deflector plate.

16. A cooling apparatus of Claim 14 or Claim 15, wherein the side plates are each laterally movable with respect to the deflector plate so as to adjust the width of the deflector.

17. Cooling apparatus substantially as herein described with respect to the attached drawings.

18. A method of cooling a vehicle engine in a wind tunnel using airflow generated by the wind tunnel substantially as herein described.