GB2564086B

GB2564086B - Heat retention apparatus and method

Info

Publication number: GB2564086B
Application number: GB1707317.2A
Authority: GB
Inventors: Richard Hutchins William
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2017-05-08
Filing date: 2017-05-08
Publication date: 2019-09-18
Anticipated expiration: 2037-05-08
Also published as: GB201707317D0; GB2564086A

Description

HEAT RETENTION APPARATUS 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 an apparatus 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 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 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 an apparatus for use with an engine, the apparatus comprising: a first structure configured to at least partially surround a first portion of the engine, the first structure configured to provide thermal insulation of the first portion of the engine to retain engine heat, the first structure configured to be provided in a spaced apart relationship with the first portion of the engine to allow air flow between the first structure and the first portion of the engine; a second structure configured to at least partially surround a second portion of the engine, the second structure configured to provide thermal insulation of the second portion of the engine to retain engine heat, the second structure configured to be provided in a spaced apart relationship with the second portion of the engine to allow air flow between the second structure and the second portion of the engine; wherein the second portion of the engine includes at least one of: an exhaust manifold; a turbocharger or a supercharger; an exhaust system component.

The second structure is capable of withstanding a higher operating temperature compared to the first structure. Optionally, the apparatus comprises at least one of: a fan device and a deflector configured to direct air into the second structure.

Optionally, the apparatus comprises at least one of: a fan device and a deflector configured to direct air into the first structure.

Optionally, the second portion of the engine is located alongside the first portion of the engine, and the first structure is configured to at least partially surround the first portion of the engine and does not surround the second portion of the engine.

Optionally, the second portion of the engine is located alongside the first portion of the engine, and the first structure is configured to at least partially surround the first portion of the engine and a part of the second structure.

Optionally, the apparatus comprises the first structure does not contact the second structure.

Optionally, the second structure comprises a forward face, a rear face, a side face and a top face.

Optionally, at least one of the forward face and the rear face is inclined at an acute angle to horizontal.

Optionally, the second structure has a lower thermal insulating rating than the first structure.

Optionally, the second structure is formed of a different material to the first structure.

Optionally, the second structure is formed of a metal, such as stainless steel.

In a further aspect of the invention for which protection is sought there is provided a motor vehicle comprising an engine and an engine provided with an apparatus as disclosed.

In another aspect of the invention for which protection is sought there is provided a motor vehicle comprising an engine and an apparatus as disclosed.

In another aspect of the invention for which protection is sought there is provided a method for use with an engine comprising: providing a first structure which at least partially surrounds a first portion of the engine, the first structure provided in a spaced apart relationship with the first portion of the engine to allow air flow between the first structure and the first portion of the engine; providing a second structure which at least partially surrounds a second portion of the engine, the second structure provided in a spaced apart relationship with the second portion of the engine to allow air flow between the second structure and the second portion of the engine, wherein the second portion of the engine includes at least one of: an exhaust manifold; a turbocharger or a supercharger; an exhaust system component; causing a flow of air into the first structure and into the second structure, wherein air flowing into each of the structures displaces heated air within the structures; and retaining heated air within the first structure and within the second structure when the flow of air into the structures ceases, wherein the second structure is capable of withstanding a higher operating temperature compared to the first structure.

Embodiments of the present invention have the feature that air surrounding the engine within the structures that becomes heated by the engine will remain trapped within the structures unless air is forced upwardly into the structures due to movement of the vehicle or the action of a fan device, as discussed below. However, advantageously, when the engine is switched off and air is no longer being forced upwardly into the structures due to movement of the vehicle, ambient air heated by the engine remains substantially trapped within the volumes defined by the structures. It is to be understood that 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 structures, reducing the rate of cooling of the engine. It is to be understood that, by reducing the rate of cooling of the engine, higher engine start-up temperatures may be enjoyed, depending on the time for which the engine remains switched off. Higher engine startup temperatures reduce 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.

Within the scope of the appended claims it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, 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 that falls within the scope of the appended claims, 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 vehicle engine with apparatus according to an embodiment of the invention; FIGURE 2 is another schematic illustration of the vehicle engine with apparatus of the embodiment of FIG. 1 showing an airflow path through the second structure; FIGURE 3 is a schematic illustration of a side view of the vehicle engine with apparatus of the embodiment of FIGS. 1 and 2; FIGURE 4 is a schematic illustration of the apparatus of the embodiment of FIGS. 1-3; FIGURE 5 is a schematic illustration of a side view of another embodiment.

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 right 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 having a head portion (or ‘head’) 121H, a block portion (or ‘block’) 121B and a sump portion (or ‘sump’) 121S. In the embodiment illustrated in FIG. 1 the engine 121 is located between a pair of front wheels 151 of the vehicle 100. An undertray 145 is provided below the engine 121 and spans at least part of a distance between a front bumper 104 and a cabin bulkhead 102. The tray 145 is discontinuous, allowing for flow or air downwardly out from the engine compartment 120. The engine 121 comprises an exhaust manifold 122, a turbocharger or a supercharger 123, a catalytic device 124 and a particulate filter 125, such as a diesel particulate filter or a gasoline particulate filter. In the embodiment shown in FIG. 1 the exhaust manifold 122, the turbocharger 123, the catalytic device 124 and the particulate filter 125 are located to one side of the engine block 121B and engine head portion 121H.

The engine 121 is provided with an apparatus 130 for promoting engine heat retention. The apparatus 130 comprises a first structure 131 and a second structure 160. The first structure 131 is configured to at least partially surround, or encapsulate, a first portion of the engine 121. The first structure 131 is configured to provide thermal insulation of the first portion of the engine 121. The first structure 131 comprises insulating material. The first structure 131 can retain engine heat when the engine is switched off. The first structure 131 is provided in a spaced apart relationship with the engine 121 to allow air flow between the first structure and the engine 121. The first structure 131 has an open lower face. The first structure 131 is substantially in the form of an inverted cup that encloses the head 121H and substantially the entire block 121B of the engine 121. The sump 121S of the engine 121 protrudes below a lower edge of the shell structure 131 in the embodiment shown. In some alternative embodiments the lower edge of the first structure 131 may be substantially at or below a lower level of the sump 121S. In the embodiment of FIG. 1 the first structure 131 may be said to have an upper, or top, portion and a downwardly-directed skirt portion 132 that projects downwardly from the top portion.

The first structure 131 may be provided as a single integral piece (e.g. which can be lifted from the engine) or as a plurality of pieces which fit together to provide the first structure. Examples of suitable materials for the shell structure include cellular foam or matted fibres. The first 131 may comprise layered skins of material or a composite/bonded assembly of materials.

The first structure 131 and the second structure 160 may be provided in addition to any insulation lining a periphery of the engine compartment 120. For example, insulation material may be provided on one or more of: an underside of the bonnet 103; the cabin bulkhead 102; sides of the engine compartment 120. Alternatively, the first structure 131 and the second structure 160 may be provided instead of any insulation lining a periphery of the engine compartment 120. The structures 131, 160 provides thermal insulation at a closer distance to the engine 121 than insulation lining the engine compartment. The structures 131, 160 provide a more effective way of reducing heat loss from the engine 121.

The second structure 160 is configured to at least partially surround a second portion of the engine 121. In the embodiment shown in FIG. 1 the second portion of the engine includes the exhaust manifold 122, the turbocharger/supercharger 123 (or multiple turbochargers or superchargers), the catalytic device 124 and the particulate filter 125. These components of the engine have a very high operating temperature, e.g. 300-400°C, or up to 800°C. There is an advantage to retaining heat in these components of the engine after shut down. The second structure 160 has an open lower face. In the embodiment shown the second portion of the engine is located alongside the first portion of the engine, i.e. on a side of the engine. In other embodiments the second structure 160 may be configured to at least partially surround one or more of: the exhaust manifold 122, the turbocharger/supercharger 123 (or multiple turbochargers or superchargers), the catalytic device 124 and the particulate filter 125.

An example of a suitable construction of the second structure 160 is a twin-walled structure or a layered structure. An example of a suitable material of the second structure 160 is a metal such as stainless steel.

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 optionally has active grill shutters 105S that are pivotable between an open condition and a closed condition. In the open condition the active grill shutters 105S permit a flow of ram air into the engine compartment 120 when the vehicle 100 travels in a forward direction. In the closed condition the active grill shutters 105S block a flow of ram air into the engine compartment 120 when the vehicle 100 travels in a forward direction. The active grill shutters 105S are caused to switch between the open and closed conditions by means of an actuator device under the control of a controller 100C in a known manner.

The radiator pack 140 has a fan device (or blower) 143 arranged to draw air through a radiator 141 and front grille 105 when the active grill shutters 105R are open. The fan device 143 blows the air rearwardly towards the first structure 131. In the present embodiment the fan device 143 is electrically powered although in some embodiments the device 143 may be engine driven.

Some of the air blown rearwardly by the fan device 143 is deflected downwardly by the first structure 131. A device is provided to deflect, or to guide, or to scoop, a portion of the air flowing rearwardly through the engine compartment 120. FIG. 1 shows a deflector 147. This may be called an air velocity deflector 147. The air velocity deflector 147 directs the air under the lower edge 133 of the skirt portion of the first structure 131 and upwardly between the engine 121 and first structure 131. Air drawn through the front grille 105 is thus introduced into the first structure 131 and forced in an upward direction between the engine block 121B and the first structure 131. Existing air within the first structure 131 is therefore displaced, being ultimately forced downwardly out from the first structure 131 and exhausted from the engine compartment 120.

The air velocity deflector 147 may be open or closed at the sides. In some alternative embodiments the deflector 147 may be in the form of an open air-deflecting surface arranged to direct air from the front of the vehicle 100 upwardly into the first structure 131. The deflector 147 may be referred to as a scoop in some embodiments. In some embodiments an air velocity deflector 147 may not be provided.

In FIG. 1 air flow lines are shown, illustrating the flow of air passing through the radiator grill 105, the radiator pack 140, the air velocity deflector 147 and within the first structure 131.

It is to be understood that, in the present embodiment, the flow rate of air through the deflector 147 and up within the first structure 131 may be controlled at least in part by means of the active grill shutters 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 active grill shutters 105R (causing them to open and close). The controller 100C monitors the temperature of the engine 121 by means of a temperature sensor 101. When the temperature exceeds a first predetermined temperature the controller 100C causes the active grill shutters 105R to open. For example, the first predetermined temperature can be in the range from around 80-90 °C. If the temperature exceeds a second predetermined temperature the controller 100C causes the fan device 143 to switch on in addition to maintaining the active grill shutters 105R in the open condition.

It is to be understood that, in use, the engine 121 and first structure 131, which is fixedly coupled to the engine 121, experience movement within the engine bay 120 such as a rocking movement during acceleration and deceleration. Whilst in some embodiments the air velocity deflector 147 could be coupled to the radiator pack 140 to increase the flow of air through the deflector 147, the fact that the engine 121, first structure and air velocity deflector 147 are decoupled from the radiator pack 140 in the present embodiment eliminates problems associated with direct coupling such as wear. In the present embodiment the air velocity deflector 147 is positioned such that a flow of air is maintained therethrough from the radiator pack 140, when the blower device is running, even at the extremes of movement of the engine 121 within the engine bay 120 in normal use.

In the embodiment of FIG. 1, engine sump 121S protrudes below the first structure 131 and is exposed to air flowing between the undertray 145 and first structure 131.

In the embodiment shown, the sump 121S is provided with close-coupled thermal insulation thereover in the form of a sprayed-on foam insulation layer. Other forms of thermal insulation may be useful such as sheet-form insulation 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 thermal insulation is not provided in contact with the sump 121S. FIG. 2 shows just the engine 121 and the structures 131, 160 with other features being omitted for clarity. A deflector or scoop 161 is provided proximate a forward edge 163 of the second structure 160. The deflector 161 may also be called an air velocity director. Some of the air blown rearwardly by the fan device 143 (FIG. 1) is collected by the deflector 161. The deflector 161 directs the air under the forward lower edge 163 of the second structure 160 and upwardly into the second structure 160. Air drawn through the front grille 105 is thus introduced into the second structure 160 and forced into the second structure 160. Existing air within the second structure 160 is therefore displaced, being ultimately forced downwardly out from the second structure 160 and exhausted from the engine compartment 120. When the vehicle is at rest, and any fan device 143 is switched off, heated air is retained within the second structure 160. This allows the engine components within the second structure 160 to more quickly reach an optimum operating temperature. For example, the catalytic device may require a shorter time to return to an optimum operating temperature.

The air velocity deflector 161 may be open or closed at the sides. The deflector 161 may be in the form of an open air-deflecting surface arranged to direct air from the front of the vehicle 100 upwardly into the second structure 160. In some embodiments the deflector 161 may not be provided. FIG. 3 is a side view of the engine 121, the first structure 131 and the second structure 160. Other components such as the front grille 105 and bonnet 103 are omitted for clarity. The first structure 131 is provided on a side and on a top of the engine 121, in addition to the front and the back of the engine (shown in FIG. 1). In this embodiment, the first portion of the engine 121 can be considered as the engine block 121B and the engine head 121H, and the first structure 131 surrounds the engine block 121B and the engine head 121H on a total of three sides of the engine (front, rear, side) in addition to the top. The first structure 131 includes a portion 134 which terminates alongside the head portion 121H of the engine 121. In this embodiment the first structure 131 does not contact the second structure 160 to prevent any damage due to the high surface temperature of the second structure 160 during operation. In another embodiment, the first structure 131 may contact the second structure 160. The first structure 131 may be formed of a heat resistant material in the region where it contacts the second structure 160. FIG. 3 shows a gap between the second structure 160 and the first structure 131. This gap may provide a function of allowing thermal expansion of the second structure 160 and avoiding contact between the first structure 131 and the (much hotter) second structure 160. The size of the gap may be minimised to avoid thermal loss from the exposed engine 121. FIG. 4 is a perspective view of the first structure 131, the second structure 160 and the deflector 161. Other components are omitted for clarity. In this embodiment the second structure 160 comprises a forward face 165, a rear face 166, a side face 167 and a top face 168. In other embodiments the second structure may have a rounded shape. The forward face 165 and the rear face 166 are inclined at an acute angle to a horizontal reference. The inclined angle of the forward face 165 and the rear face 166 can assist flow of cooling air through the second structure 160. FIG. 5 shows a side view of another embodiment of the apparatus, with the engine 121, a first structure 231 and a second structure 160. FIG. 5 is similar to FIG. 3 and like components are labelled with like reference numerals. In this embodiment the first structure 231 extends over the top of the second structure 160 and contacts the second structure 160.

Optionally, the first structure 231 may extend down at least part of the side of the second structure with a gap between the first structure 231 and the side of the second structure 160.

The first structure 131, 231 and the second structure 160 can each be optimised for the i portion of the engine that it surrounds. The first portion of the engine (e.g. engine block 121B) is water-cooled and therefore has a lower operating temperature than the second portion of the engine. The first structure 131, 231 can be formed of a material such as a soft material with a high insulating rating while the second structure 160 can be formed of a material which is better suited to high operating temperatures. The second structure 160 provides thermal insulation to the second portion of the engine, but is engineered to survive high operating temperatures. In any of the embodiments, airflow into each of the first structure 131, 231 and the second structure 160 can be independently controlled. For example, the inlet deflector 161 and the shape of the second structure 160 can be configured to provide a higher flow of cooling air during operation compared to inlet deflector • 147 and the first structure 131,231. A fan device may be provided for each of the structures, and each of the fan devices may be independently controlled to provide a flow of cooling air during operation.

In some embodiments, one or more fan devices may be provided for directing air into the first structure 131 substantially directly and not via the radiator pack 140. Additionally, or alternatively, one or more fan devices may be provided for directing air into the second structure 160, 260, 360 substantially directly and not via the radiator pack 140.

It is to be understood that a first 131 according to an embodiment of the invention may itself • have a lower edge 133 that is any suitable depth (distance) below the top of the engine block 121B such as 50%, 75%, 80, 90%, 100%, 110%, 120% or any other suitable depth.

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.

I

Claims

CLAIMS:

1. Apparatus for use with an engine, the apparatus comprising: a first structure configured to at least partially surround a first portion of the engine, the first structure configured to provide thermal insulation of the first portion of the engine to retain engine heat, the first structure configured to be provided in a spaced apart relationship with the first portion of the engine to allow air flow between the first structure and the first portion of the engine; a second structure configured to at least partially surround a second portion of the engine, the second structure configured to provide thermal insulation of the second portion of the engine to retain engine heat, the second structure configured to be provided in a spaced apart relationship with the second portion of the engine to allow air flow between the second structure and the second portion of the engine; wherein the second portion of the engine includes at least one of: an exhaust manifold; a turbocharger or a supercharger; an exhaust system component; wherein the second structure is capable of withstanding a higher operating temperature compared to the first structure.

2. An apparatus according to claim 1 comprising at least one of: a first fan device and a first deflector configured to direct air into the second structure.

3. An apparatus according to claim 1 or 2 comprising at least one of: a second fan device and a second deflector configured to direct air into the first structure.

4. An apparatus according to any one of the preceding claims wherein the second portion of the engine is located alongside the first portion of the engine, and the first structure does not surround the second portion of the engine.

5. An apparatus according to any one of the preceding claims wherein the second portion of the engine is located alongside the first portion of the engine, and the first structure is configured to at least partially surround a part of the second structure.

6. An apparatus according to any one of the preceding claims wherein the first structure does not contact the second structure.

7. An apparatus according to any one of the preceding claims wherein the second structure comprises a forward face, a rear face, a side face and a top face.

8. An apparatus according to claim 7 wherein at least one of the forward face and the rear face is inclined at an acute angle to horizontal.

9. An apparatus according to any one of the preceding claims wherein the second structure has a lower thermal insulating rating than the first structure.

10. An apparatus according to any one of the preceding claims wherein the second structure is formed of a different material to the first structure.

11. An apparatus according to claim 10 wherein the second structure is formed of a metal.

12. A motor vehicle engine provided with apparatus according to any one of the preceding claims.

13. A motor vehicle comprising an engine and apparatus according to any one of claims 1 to 11.

14. A method for use with an engine comprising: providing a first structure which at least partially surrounds a first portion of the engine, the first structure provided in a spaced apart relationship with the first portion of the engine to allow air flow between the first structure and the first portion of the engine; providing a second structure which at least partially surrounds a second portion of the engine, the second structure provided in a spaced apart relationship with the second portion of the engine to allow air flow between the second structure and the second portion of the engine, wherein the second portion of the engine includes at least one of: an exhaust manifold; a turbocharger or a supercharger; an exhaust system component; causing a flow of air into the first structure and into the second structure, wherein air flowing into each of the structures displaces heated air within the structures; and retaining heated air within the first structure and within the second structure when the flow of air into the structures ceases; wherein the second structure is capable of withstanding a higher operating temperature compared to the first structure.