GB2562224B

GB2562224B - Heat retention member and method

Info

Publication number: GB2562224B
Application number: GB1707307.3A
Authority: GB
Inventors: Ian Chandler Paul
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2017-05-08
Filing date: 2017-05-08
Publication date: 2019-07-31
Anticipated expiration: 2037-05-08
Also published as: GB201707307D0; DE102018206365A1; GB2562224A

Description

HEAT RETENTION MEMBER AND METHOD

FIELD OF THE INVENTION

Aspects of the present invention relate to improvements in the efficiency of vehicle operation. In particular, aspects of the present invention relate to a structure for promoting engine heat retention when the engine is not in use, to an engine, to a motor vehicle and to a method.

BACKGROUND

The efficiency of internal combustion engines is known to be dependent at least in part on the viscosity (and therefore the temperature) of the oil used to lubricate the crank bearings and cylinders of the engine. Accordingly, it is desirable for internal combustion engines to be able to attain their normal operating temperature as quickly as possible following a cold start.

It is known to provide a layer of thermal insulation over portions of an engine in order to reduce heat loss when the vehicle is parked for extended periods. However, it is desirable to further reduce heat loss whilst a vehicle is parked whilst still obtaining effective engine cooling during normal vehicle operations.

It is against this background that the present invention has been conceived. Embodiments of the invention provide a structure, a method or a vehicle which addresses the above problems. Other aims and advantages of the invention will become apparent from the following description, claims and drawings.

SUMMARY OF THE INVENTION

In one aspect of the invention for which protection is sought there is provided a motor vehicle engine heat retention member comprising a thermal insulation portion configured to at least partially encapsulate a sump portion of a motor vehicle engine to reduce heat loss therefrom, and at least one air conduit, the at least one air conduit having an air inlet provided in a front region of the heat retention member for receiving a flow of ambient air, and at least one air outlet at a rear region of the heat retention member, the at least one air outlet being arranged to direct the ambient air to flow upwardly over a rear surface of the engine to cause cooling thereof.

Embodiments of the present invention have the advantageous feature that the same structure can be employed to reduce heat loss from an engine, for example when the engine is switched off, whilst at the same time being capable of directing a flow of ambient air over the engine to cause cooling when air is directed into the air inlet, for example by an engine cooling fan when the engine is running. Thus, the thermal insulation portion may serve the purpose of insulating the lower region of the engine from heat loss whilst at the same time the member causes a flow of air over a rear surface of the engine to promote cooling of the engine.

Optionally, the thermal insulation portion comprises an open body having a hollow arranged to receive the sump of the engine.

The thermal insulation portion may be arranged to be provided in thermal contact with the sump.

Optionally, the hollow in the open body is provided with a shape corresponding to that of the sump.

Optionally, the air conduit is arranged to convey air along a flow path that passes underneath the sump portion of the engine.

Optionally, the at least one conduit is integrally formed with the thermal insulation portion.

Optionally, the at least one conduit is formed in a wall of the thermal insulation portion.

Optionally, the at least one conduit is formed in a component that is coupled to a wall of the thermal insulation portion.

Optionally, the at least one conduit is formed in a component that is coupled to an underside of the thermal insulation portion.

The member may comprise a plurality of air conduits.

Optionally, at least one air conduit is provided at or near a left side of the thermal insulation portion and at least one air conduit is provided at or near a right side of the thermal insulation portion. That is to say at least two air conduits are provided at or near opposite lateral sides of the thermal insulation portion.

In a further aspect of the invention for which protection is sought there is provided a motor vehicle engine having a sump that is provided with a member according to another aspect coupled thereto.

Optionally, the air outlet of the at least one air conduit is arranged to direct air to flow upwardly over a turbocharger of the engine.

The engine may be further provided with a thermal shell portion, the thermal shell portion being arranged to at least partially encapsulate the engine, the shell portion being arranged to be provided in a spaced apart relationship with the engine thereby to allow circulation of air between the shell portion and engine, the shell portion comprising a substantially downwardly directed open skirt portion arranged to at least partially surround a block of the engine, the shell portion being arranged to substantially prevent flow of air out from the shell portion above a predetermined depth below an upper surface of the engine block, the skirt portion being arranged to allow air to flow upwardly or downwardly into and out from the thermal shell portion between the engine and shell portion.

The presence of the thermal shell portion has the advantage that air surrounding the engine within the thermal shell that becomes heated by the engine will remain substantially trapped within the shell unless air is forced upwardly into the thermal shell, for example due to movement of the vehicle or the action of a blower. Similarly, air can escape from the shell by passing below a lower edge of the skirt portion. However, advantageously, when the engine is switched off and air is no longer being forced upwardly into the thermal shell, ambient air heated by the engine remains substantially trapped within the volume defined by the shell. This is due to the greater buoyancy of air warmed by the engine relative to ambient air.

Thus embodiments of the present invention have the advantage that circulation of relatively cool, ambient air may take place over the engine block when the engine is in use. Whilst when the engine is switched off, relatively warm ambient air may be trapped between the engine and shell, reducing the rate of cooling of the engine. Accordingly, the probability that the engine will still be at a temperature above ambient temperature when it is next switched on is increased, reducing the losses associated with higher oil viscosity. Higher engine temperatures at start-up may also increase the rate at which an engine after-treatment system warms to its normal operating temperature.

Optionally, the thermal shell portion is formed at least in part from a thermal insulator material.

The thermal insulator material may comprise any suitable material such as a polyurethane foam, a fibrous material, an insulating board material such as a corrugated sheet of material such as a high temperature plastics material or fibre board material laminated on one or both sides with a substantially flat sheet of the same or a different material, or any other suitable material.

Optionally, the air outlet is arranged to direct air to flow upwardly into a volume between the engine and thermal shell portion.

In a further aspect of the invention for which protection is sought there is provided a motor vehicle having an engine according to another aspect.

In another aspect of the invention for which protection is sought there is provided a method of cooling comprising providing a motor vehicle engine heat retention member comprising a thermal insulation portion such that it at least partially encapsulates a sump portion of a motor vehicle engine to reduce heat loss therefrom, and at least one air conduit, the at least one air conduit having an air inlet provided in a front region of the heat retention member for receiving a flow of ambient air, and an air outlet at a rear region of the heat retention member, the air outlet being arranged to direct the ambient air to flow upwardly over a rear surface of the engine to cause cooling thereof.

The method may comprise causing air to flow into the air inlet of the at least one air conduit and out from the air outlet over the rear surface of the engine to cause cooling thereof.

The method may further comprise providing a thermal shell arranged to at least partially encapsulate an engine, the shell being arranged to be provided in a spaced apart relationship with the engine thereby to allow circulation of air between the shell and engine, the shell comprising a substantially downwardly directed open skirt portion arranged to at least partially surround an engine block of the engine, the structure being arranged to substantially prevent flow of air out from the structure above a predetermined depth below an upper surface of the engine block, the method comprising causing a flow of air upwardly into the heat retention structure from the air outlet to a region between the engine and shell portion via the skirt portion.

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.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIGURE 1 is a schematic illustration of a side view in cross-section of front portion of a vehicle having an engine having a heat retention structure according to an embodiment of the invention fitted thereto; FIGURE 2 is an exploded view of the engine heat retention structure of the embodiment of FIG. 1; FIGURE 3 is a schematic illustration of (a) an engine heat retention structure of a vehicle according to a further embodiment of the invention and (b) an engine heat retention structure of a vehicle according to a still further embodiment of the invention.

DETAILED DESCRIPTION FIG. 1 is a schematic illustration of a front portion of a vehicle 100 according to an embodiment of the present invention in cross-sectional form as viewed in a transverse direction, i.e. with the vehicle viewed from one side (in the present illustration, a left side). The vehicle 100 has an engine compartment 120 covered by a bonnet (or hood) 103 and separated from a cabin of the vehicle by a cabin bulkhead 102. The engine compartment 120 houses an engine 121, transmission (not shown) and various other components and vehicle systems. The engine 121 has a head portion (or ‘head’) 121H, a block portion (or ‘block’) 121B and a sump portion (or ‘sump’) 121S. In the embodiment shown the engine 121 is also provided with a turbocharger device 125. An engine undertray 145 is provided below the engine 121 and spans a distance between a front bumper 104 and cabin bulkhead 102. The tray 145 is provided with apertures 145A therein in a rearward portion, allowing for flow or air downwardly out from the engine compartment 120.

The engine 121 is provided with a thermal shell structure or portion 130 (which may also be referred to as an ‘insulation cover’) substantially in the form of an inverted box-shaped cup that encloses an upper portion of the engine 121 including the head 121H of the engine 121 and a substantial portion of the block 121B of the engine 121.

In the embodiment of FIG. 1 the thermal shell structure 130 may be said to have an upper or top portion 130T and a downwardly-directed skirt portion 130S that projects downwardly from the top portion 130T.

The engine 121 is also provided with an engine heat retention member in the form of a sump thermal insulation cover 135S as shown in FIG. 1 and (in exploded form) FIG. 2. The cover 135S has a cover insulation portion 135SC also referred to as a cover thermal insulation portion that encapsulates the exposed portion of the engine sump 121S and a conduit or duct portion 135SD that fits into a recess formed in an outer (lower) surface of the cover insulation portion 135SC. The cover insulation portion 135SC is in the form of an open body or shell having a hollow therein that conforms to the external shape of the sump 121S of the engine 121. When offered to the sump 121S, the cover insulation portion 135SC forms a snug fit in thermal contact with the surface of the sump 121S. The duct portion 135SD has an air inlet 135SDI and an air outlet 135SDO. In the embodiment of FIG. 2 the cover insulation portion 135SC and duct portion 135SD are separate components that are joined to form the cover 135S. In some alternative embodiments the cover insulation portion 135SC and duct portion 135SD are integrally formed, for example by injection moulding to provide a cover 135S in the form of a single component.

The purpose of the cover insulation portion 135SC is to provide thermal insulation for the sump 121S, reducing the rate of cooling when the engine 121 is not running. The purpose of the duct portion 135SD is to direct air entering the air inlet 135SDI to flow under the cover insulation portion 135SC and out from the duct portion 135SD via air outlet 135SDO in a substantially upward direction over a rearward-facing surface of the engine 121. The duct portion 135SD incorporates a right-angle bend by means of which the direction of air flow is turned through substantially 90 degrees before it exits the air outlet 135SDO. In the embodiment of FIG. 1 and FIG. 2, air flowing out from the air outlet 135SDO is directed to impinge upon a turbocharger 125 that is located within the thermal shell structure 130 on the rearward-facing surface of the engine 121. It is to be understood that in the embodiment shown the duct portion 135SD is positioned substantially centrally with respect to a width of the cover insulation portion 135SC (i.e. with respect to a lateral or ‘east-west’ dimension of the engine 121). The additional flow of air over the turbocharger from the air outlet 135SDO enhances cooling of the turbocharger 125, assisting in maintaining component temperatures within operational limits.

The vehicle 100 has a radiator pack 140 provided within the engine compartment 120 behind a front grille 105 of the vehicle 100. The front grille 105 has ram flaps 105R that are pivotable between open and closed conditions in which they permit and block, respectively, a flow of ram air into the engine compartment 120 when the vehicle 100 travels in a forward direction. The ram flaps 105R are caused to switch between the open and closed conditions by means of an actuator device under the control of a controller 100C.

The radiator pack 140 has a fan device 143 arranged to draw air through a radiator 141 and the front grille 105 when the ram flaps 105R are open. The fan device 143 blows the air rearwardly towards the engine 121 via a radiator pack flow duct MOD. The air is thereby forced to flow through the duct portion 135SD of the sump thermal insulation cover 135S. FIG. 3(a) is a schematic illustration of a sump thermal insulation cover 235S according to a further embodiment of the present invention. Like features of the embodiment of FIG. 3(a) to those of the embodiment of FIG. 2 are provided with like reference signs incremented by 100.

In the embodiment of FIG. 3(a) the cover 235S has an insulation portion 235SC arranged to substantially surround an exposed portion of the engine sump 121S in substantially direct thermal contact therewith and a pair of duct portions 235SD located on respective opposite (left and right) lateral sides of the cover portion 235SC. Each duct has a respective forwardfacing (in use) air inlet 235SDI and an upward-facing air outlet 235SDO. The duct portions 235SD are arranged to cause the direction of air flow through the duct portions 235SD to bend through substantially 90 degrees before exiting the outlets 235SDO. The flow of air from the duct portions 235SD is therefore in a substantially upward direction, promoting flow of air into the thermal shell structure 130. In some embodiments the duct portions 235SD may be configured to direct air to flow over a region of the engine 121 requiring additional cooling effort such as a turbocharger device, exhaust manifold or the like. FIG. 3(b) is a schematic illustration of a sump thermal insulation cover 335S according to a further embodiment of the present invention. Like features of the embodiment of FIG. 3(b) to those of the embodiment of FIG. 3(a) are provided with like reference signs incremented by 100.

In the embodiment of FIG. 3(b) the cover 335S also has an insulation portion 335SC arranged to substantially surround an exposed portion of the engine sump 121S in substantially direct thermal contact therewith, in a similar manner to the embodiment of FIG. 3(a). A pair of duct portions 335SD are located on respective opposite (left and right) lateral sides of the cover portion 335SC. Each duct has a respective forward-facing (in use) air inlet 235SDI and a rearward-facing air outlet 335SDO. The duct portions 335SD are arranged to cause the direction of air flow through the duct portions 235SD to bend through an angle of around 45 degrees before exiting the outlets 235SDO. It is to be understood that in some embodiments the air outlets 335SDO may be configured to direct air to further air conduits that direct the air flow to a desired location, in some embodiments upwardly into the thermal shell structure 130. In some embodiments the air may be directed to one or more deflectors that deflect the air upwardly into the thermal shell structure 130.

In some embodiments, the sump 121 may be provided with close-coupled thermal insulation thereover in the form of either of a polyurethane (PUR) foam or fibrous material or a sprayed-on foam such as a sprayed-on polyurethane foam to form an insulation layer in addition to the installation of a cover insulation portion 135SC, 235SC. The cover insulation portion may be formed from any suitable material. In some embodiments the cover insulation portion may be formed at least in part from a polyurethane foam or any other suitable insulation material.

The cover insulation portion 135SC, 235SC may be bonded to the sump by means of an adhesive, or attached thereto by means of mechanical fixing elements such as screws, bolts, clips or the like.

In some embodiments, one or more fan devices may be provided in addition to the fan device 143 within the radiator pack 140 for directing air rearwardly towards the engine 121.

It is to be understood that, in the present embodiment, the flow rate of air through the radiator pack flow duct MOD towards the thermal shell structure 130 and sump thermal insulation cover 135S, 235S may be controlled at least in part by means of the ram flaps 105R of the front grille 105 (open or closed) and the state of the fan device 143 (on or off).

In the present embodiment, controller 100C is provided for controlling the state of the fan device (switching it on or off) and the state of the ram flaps 105R (causing them to open and close). The controller 100C monitors the temperature of the engine 121 by means of a temperature sensor 121TS located within the thermal shell structure 130. In the embodiment of FIG. 1 the sensor 121TS is located in an upper region of the thermal shell structure 130 where the temperature is expected to be higher than in lower regions due to buoyancy and heat soak after engine shutdown.

When the temperature exceeds a first predetermined temperature the controller 100C causes the ram flaps 105R to open. In the present embodiment the first predetermined temperature is in the range from around 80-90C. If the temperature exceeds a second predetermined temperature the controller 100C causes the fan device 143 to switch on in addition to maintaining the ram flaps 105R in the open condition. In the present embodiment the second predetermined temperature is in the range from 100-110C. It is to be understood that other values of first and/or second predetermined temperatures may be useful in some embodiments.

It will be understood that the embodiments described above are given by way of example only and are not intended to limit the invention, the scope of which is defined in the appended claims.

Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of the words, for example “comprising” and “comprises”, means “including but not limited to”, and is not intended to (and does not) exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

Claims

CLAIMS:

1. A motor vehicle engine heat retention member comprising a thermal insulation portion configured to at least partially encapsulate a sump portion of a motor vehicle engine to reduce heat loss therefrom, and at least one air conduit, the at least one air conduit having an air inlet provided in a front region of the heat retention member for receiving a flow of ambient air, and at least one air outlet at a rear region of the heat retention member, the at least one air outlet being arranged to direct the ambient air to flow upwardly over a rear surface of the engine to cause cooling thereof.

2. A member according to claim 1 wherein the thermal insulation portion comprises an open body having a hollow arranged to receive the sump of the engine.

3. A member according to claim 2 wherein the thermal insulation portion is arranged to be provided in thermal contact with the sump.

4. A member according to claim 2 or claim 3 wherein the hollow in the open body is provided with a shape corresponding to that of the sump.

5. A member according to any preceding claim wherein the air conduit is arranged to convey air along a flow path that passes underneath the sump portion of the engine.

6. A member according to any preceding claim wherein the at least one conduit is integrally formed with the thermal insulation portion.

7. A member according to claim 6 wherein the at least one conduit is formed in a wall of the thermal insulation portion.

8. A member according to any one of claims 1 to 5 wherein the at least one conduit is formed in a component that is coupled to a wall of the thermal insulation portion.

9. A member according to claim 8 wherein the at least one conduit is formed in a component that is coupled to an underside of the thermal insulation portion.

10. A member according to any preceding claim comprising a plurality of air conduits.

11. A member according to claim 10 wherein at least two air conduits are provided at or near opposite lateral sides of the thermal insulation portion.

12. A motor vehicle engine having a sump that is provided with a member as claimed in any preceding claim coupled thereto.

13. An engine according to claim 12 wherein the air outlet of the at least one air conduit is arranged to direct air to flow upwardly over a turbocharger of the engine.

14. An engine according to claim 12 or 13 further provided with a thermal shell portion, the thermal shell portion being arranged to at least partially encapsulate the engine, the shell portion being arranged to be provided in a spaced apart relationship with the engine thereby to allow circulation of air between the shell portion and engine, the shell portion comprising a substantially downwardly directed open skirt portion arranged to at least partially surround a block of the engine, the shell portion being arranged to substantially prevent flow of air out from the shell portion above a predetermined depth below an upper surface of the engine block, the skirt portion being arranged to allow air to flow upwardly or downwardly into and out from the thermal shell portion between the engine and shell portion.

15. An engine according to claim 14 wherein the thermal shell portion is formed at least in part from a thermal insulator material.

16. An engine according to claim 14 or 15 wherein the air outlet is arranged to direct air to flow upwardly into a volume between the engine and thermal shell portion.

17. A motor vehicle having an engine according to any one of claims 12 to 16.

18. A method of cooling comprising providing a motor vehicle engine heat retention member comprising a thermal insulation portion such that it at least partially encapsulates a sump portion of a motor vehicle engine to reduce heat loss therefrom, and at least one air conduit, the at least one air conduit having an air inlet provided in a front region of the heat retention member for receiving a flow of ambient air, and an air outlet at a rear region of the heat retention member, the air outlet being arranged to direct the ambient air to flow upwardly over a rear surface of the engine to cause cooling thereof.

19. A method according to claim 18 comprising causing air to flow into the air inlet of the at least one air conduit and out from the air outlet over the rear surface of the engine to cause cooling thereof.

20. A method according to claim 18 or 19 further comprising providing a thermal shell arranged to at least partially encapsulate an engine, the shell being arranged to be provided in a spaced apart relationship with the engine thereby to allow circulation of air between the shell and engine, the shell comprising a substantially downwardly directed open skirt portion arranged to at least partially surround an engine block of the engine, the structure being arranged to substantially prevent flow of air out from the structure above a predetermined depth below an upper surface of the engine block, the method comprising causing a flow of air upwardly into the heat retention structure from the air outlet to a region between the engine and shell portion via the skirt portion.