GB2496151A

GB2496151A - An air filter unit for a motor vehicle

Info

Publication number: GB2496151A
Application number: GB201118916A
Authority: GB
Inventors: Israel Garcia Sanchez; Victor Manuel Delgado Deza; Daisuke Takada
Original assignee: Nissan Motor Manufacturing UK Ltd
Current assignee: Nissan Motor Manufacturing UK Ltd
Priority date: 2011-11-02
Filing date: 2011-11-02
Publication date: 2013-05-08
Also published as: ES2550838T3; EP2589784B1; EP2589784A1; GB201118916D0

Abstract

An air filter unit 11 for a motor vehicle, comprises a housing for mounting on an engine of the motor vehicle including an air inlet and being capable of accommodating an air filtering means therein, and including a wall 15 extending to contact against a surface of the engine such that in use one part of the engine is isolated from another part of the engine by the wall. Seals or barriers (16, 19) may be provided under the air filter unit. Advantageously, fuel carrying components (H, I) of the engine are isolated from high temperature engine components by the wall, to prevent external combustion in the case of a fuel leak.

Description

An Air Filter Unit for a Motor Vehicle The present invention relates to an air filter unit for a motor vehicle, particularly a compact vehicle where space in the engine bay is limited.

In the design of a compact vehicle it is commonplace to locate an air cleaner/filter unit on top of the engine where there is more space compared to cther areas in the tO engine bay. However, even in this location, space is restricted and any reduction in height of the air filter unit can result in an increase in engine air intake noise; and if the height of the air filter element is reduced, more frequent maintenance being required. Any constriction of the air intake passage below its optimum size can also reduce the engine's efficiency, resulting in a lower power output; and also an increase in fuel consumption, and therefore in CO2 emissions.

Also located atop a typical compact vehicle engine is a "splash cover", so-called because it prevents fuel from contacting high temperature components (e.g. the exhaust manifold or turbocharger) of the engine even if a high pressure fuel part leaks fuel. This is an important safety feature as external combustion could otherwise occur in the unlikely event of fuel component leakage or failure.

The present invention seeks to provide an air filter unit that will allow for improved performance without compromising the safety aspects of existing engine designs.

In a broad aspect, the invention provides an air filter unit for a motor vehicle comprising a housing fcr mcunting on an engine of the mctor vehicle, said housing including an air inlet and capable of accommodating an air filtering means therein, and including a wall extending to contact against a surface of the engine, such that one part of the engine is isolated frcm another part of the engine by the wall.

tO Preferably a contacting edge of the wall includes a seal means. In a preferred form the seal means comprises a rubber seal element. The rubber seal may be fixed to the air filter housing or wall by rubber harpoons.

In another broad aspect of the invention there is provided an air filter unit for a motor vehicle engine, the air filter unit including an integrated splash cover, said splash cover including a wall extending to contact a surface of the engine, such that at least one engine component having an outer surface is isolated from at least one other engine component having an outer surface by the wail.

The meaning of the term "outer surface" in this context is that the engine component has a surface which is exposed on the outer surface of the engine as a whole, as opposed to components such as pistons which are totally enclosed within the engine.

Furthermore, according to the invention, there is provided a method of installing an air filter unit to a motor vehicle engine, wherein the air filter unit includes a housing for accommodating an air filter means and is provided with a barrier wall extending from an underside thereof to contact a surface of the engine, such that the wall spatially isolates fuel carrying components of the engine from high temperature components of the engine to prevent migration of fuel therebetween.

Acoording to all aspects of the invention, the wall which extends to oontaot a part of the engine (e.g. a rocker cover) forms a barrier through which leaked fuel, that may originate in fuel carrying components mounted on one tO part of the engine, cannot contact hot compcnents mounted on another external part of the engine.

An air filter unit according to the invention avoids the need for a separate splash cover component; thus reducing the overall number of parts, and simplifying engine assembly, while maintaining an equivalent safety function. Moreover, dispensing with the conventional splash cover frees up space for a larger (higher or deeper) air filter element to be used, with a corresponding increase in performance (less pressure drop on the air intake to the engine), and reduced noise.

An air filter unit according to the present invention will be described hereinafter with reference to the accompanying drawings, in which:-Figures 1 to 3 illustrate various views of an existing compact vehicle engine and its components for general reference; Figures 4a and 4b illustrate sectional views of an air filter unit according to the invention fitted to an engine; Figure 5 illustrates a further detailed view of the air filter unit according to the invention; and Figure 6 illustrates a general view of a seal means attached to the air fitter unit casing according tc the invention.

Figure 1 shows an existing compact vehicle engine E that includes a splash cover S (also shown in an enlarged view), which is secured (by clips in several locations) over high-pressure fuel carrying components of the engine. Standard engine components such as a compressor tO C, an oil filter C, a flywheel F and an alternator T are also shown. The spray cover S is a contoured, moulded component that is intended to prevent any fuel from escaping and contacting hot components. At least one drain channel DC is provided to allow any accumulation of leaked fuel to be directed away from the top of the engine, for example into the sump.

Figure 2 illustrates a side section view of a partly assembled engine E without a splash cover fitted. In this scenario any fuel leaking from a high pressure fuel connection H may possibly migrate in the direction of arrow U over the rocker cover F toward an exhaust manifold X, turbocharger G, or turbocharger heat shield K. A combustion chamber J to which a fuel injector I delivers fuel is shown for completeness.

It will be apparent that an engine in the form shown by Figure 2 is not optimized in safety terms because external combustion could result as a conseguence of any leaked fuel passing in the particular direction shown. It must be stressed that the engine configuration in this Figure is incomplete for the sake of ciarity of illustration. Components such as an air filter unit which are omitted from this view could restrict, but not entirely prevent, passage of leaked fuel.

Figure 3a shows a plan view of an existing engine layout where an air cleaner/filter unit L is visible.

Furthermore, an air flow meter N measures air flow into the filter, whereas a splash cover S is seen in place underneath the air filter unit L. The corresponding sectional views along lines A-A (Figure Sb) and B-B tO (Figure Sc) show that the air filter unit L is mounted with a gap or mechanicalL clearance P between itself and the surface of the splash cover S. The purpose of gap P is to keep intake air cool, and to avoid noise and vibration damage that could occur if the air filter unit L rattles against the engine.

With the state of the art layout of a compact vehicle engine now summarised, the air filter unit of the present invention is described by reference to Figures 4 to 6.

Firstly, with reference to Figures 4a and 4b, the separate splash cover component S from previous drawings is removed completely; and only an air filter unit 11 is located above the rocker cover R of the engine F. The air filter unit ii of the invention is capable of housing an air filter element with a notably greater height, since the separate splash cover component is not present. Filter 11 is generally comprised of a topside wall 12 (which may include a hatch to access the replaceable air filter element), side walls 13 and an underside wall 14 which are variously shaped to fit around the surrounding engine components. It wifl be apparent that the illustrated embodiment is substantially asymmetrical.

According to the invention, preferably protruding from the underside wall 14, a barrier wall 15 is provided whioh extends to contact the engine in the vioinity of the rooker cover R. At the contacting edge is a seal, e.g. of rubber, 16.

tO Barrier wall 15 may extend from any suitable place on the air filter unit 11. Its purpose is to isolate the high pressure fuel components H on one side of the engine from the high temperature components on the other side of the engine, which are shown in more detail in Figure 2.

The underside wall 14 in conjunction with barrier wall 15 serves to contain any fuel leak, at least in the direction D (toward the left) of Figure 2.

It will be apparent that the barrier wall 15 is an essential safety feature of the air filter unit 11 in connection with its ability to replace a splash cover S of the known type. The air filter need not necessarily have a corresponding solid barrier wall at the opposite side of the engine, where a fuel leak would not contact particularly hot components. A dotted line 17 represents a possible barrier wall to contain leaks; however, in other forms access to the high pressure fuel components H is open. Therefore, only a shroud 18 may be present that deflects any leaked fuel away from the underside of the vehicle bonnet or engine cover (not shown) Other than seal 16, the walls 13/14 of air filter unit 11 are not in substantive contact with the engine components below the air filter unit; which helps to minimise vibration damage to the filter. However, air filter unit 11 must be secured in place by suitable means, most preferably a nominal number of bolts, in the conventional way; or by other equivalent fixing means.

Figure 5 illustrates a further seal means 19 located on the underside wall 14, above the injector I and high pressure fuel hose H. Such a seal provides an additional tO barrier against leakage into the air filter unit casing or cavity where the air fitter element is located, and also provides added noise and vibration damping properties, along with thermal insulation for the intake air stream.

Figure 6 illustrates a sealing skirt component 20 that can be connected to the air filter casing II by rubber harpoons 21 to form the barrier wall 15 (these harpoons can be omitted if the components are integrated) The air filter unit of the invention can be manufactured with available tools and materials, most likely injection moulded plastic components that are suitably resistant to aggressive conditions in an engine bay. In general terms, all engine components except the air filter and splash cover can be carried over without modification to an engine incorporating an air filter unit of the invention; however, a drain channel may be pressed or moulded into the engine rocker cover to take over the function of

drain channel DC in prior art Figure 1.

In general, it will be apparent that a number of design changes to shape and configuration can be made to the air filter unit without departing from the invention. The innovation is highlighted by recognition of the problem of restricted space in a compact vehicle engine (indeed most modern vehicles) and proposal of a solution which will enable a larger (higher/deeper) and hence more efficient air filter to be utilised. 7&t the same time the solution reduces the number of engine components without a corresponding reduction in safety and functionality.

Claims

<claim-text>WHAT WE CLAIM IS: 1. An air filter unit for a motor vehicle comprising a housing for mounting on an engine of the motor vehicle, said housing including an air inlet and being capable of accommodating an air filtering means therein, and including a wall extending to oontact against a surface of the engine, suoh that, in use, one part of the engine is isolated from tO another part of the engine by the wall.</claim-text> <claim-text>2. The air filter unit of claim 1 wherein a contacting edge of the wall includes a seal means.</claim-text> <claim-text>3. The air filter unit of claim 2 wherein the seal means comprises a rubber seal element.</claim-text> <claim-text>4. The air filter unit of any of the preceding claims wherein the wall and an underside of the housing define an enclosure that, in use, spatially isolates fuel carrying components of the engine from high temperature components of the engine.</claim-text> <claim-text>5. The air filter unit of claim 4 wherein the enclosure is partial, e.g. open on one side.</claim-text> <claim-text>6. The air filter unit of claim 4 wherein the enclosure is complete.</claim-text> <claim-text>7. The air filter unit of any one of claims 4 to 6 wherein both the underside of the housing and the wall include a seal or barrier means.</claim-text> <claim-text>8. An air filter unit for a motor vehicle engine, the air filter unit including an integrated splash cover, including a wall extending to contact against a surface of the engine, such that, in use, at least one engine component having an outer surface is isolated from at least one other engine component having an outer surface by the wall.</claim-text> <claim-text>9. The air filter unit of claim 8, wherein the wall tO includes a contacting edge with a seal means.</claim-text> <claim-text>10. The air filter unit of claim 8 or claim 9, wherein the splash cover is further defined by an underside of the air filter unit that also includes a seal or barrier material.</claim-text> <claim-text>11. A method of installing an air filter unit to a motor vehicle engine, wherein the air filter unit includes a housing for accommodating an air filter means and is provided with a barrier wall extending from an underside thereof to contact a surface of the engine, such that the wall spatially isolates fuel carrying components of the engine from high temperature components of the engine to prevent migration of fuel therebetween.</claim-text> <claim-text>12. An air filter unit substantially as herein described with reference to Figures 4 to 6 of the accompanying drawings.</claim-text> <claim-text>13. A method of installing an air filter unit substantially as herein described with reference to Figures 4 to 6 of the accompanying drawings.</claim-text>