GB2177936A

GB2177936A - Air-filter arrangement

Info

Publication number: GB2177936A
Application number: GB08617228A
Authority: GB
Inventors: Hans Alfred Kochanowski
Original assignee: Motorenfabrik Hatz GmbH and Co KG
Current assignee: Motorenfabrik Hatz GmbH and Co KG
Priority date: 1985-07-23
Filing date: 1986-07-15
Publication date: 1987-02-04
Also published as: IT8620932A0; IT8620932A1; GB8617228D0; FR2585411A1; JPS6226363A; IT1191813B

Abstract

In an air filter arrangement for an internal combustion engine,the filter element (22) is mounted directly on a duct 14 which is an integral part of or directly secured to the engine casing, whereas the filter housing (32) is separate from the filter element and is independently mounted on the engine with the interposition of vibration 26 damping materials (36, 38). The filter housing in Figures 2 to 4 is an extension of the sound-deadening cowling which surrounds the engine. <IMAGE>

Description

SPECIFICATION Air filter arrangement for internal combustion engines The invention relates two an airfilter arrangement for internal combustion engines in which the airfilter comprises a filter element and a filter housing which surrounds the filter element and incorporates the air inlet.

In known arrangements ofthis kind it is necessary to use costly means, which demand a great deal of space and are thus disadvantageous, in order at least partly to damp the vibrations which emanate from the component ofthe engine casing which is subjected to extreme conditions of vibration, namely the cylinder head and its inlet duct for combustion airwhich car riestheairfilter,from being carried over directly into the airfilter and from there transmitted to thesur- rounding air.

The object of the present invention is to obviate these disadvantages and to achieve with very simple means a vibration-deadening construction ofthefilterelements and consequently optimum sound damping at the inletforthe combustion air as well.

The invention therefore provides an airfilter arrangement for internal combustion engines in which airfiltercomprisesafilterelementand a filter housing surrounding the element, saidfilterfurther incorporating an air inlet wherein the filter element is carried by a support which is directly secured to a wall ofthe engine casing, the filter housing being formed by at least one wall which is separate from thefilter element and carried on a component ofthe engine with the interposition ofvibration-deadening materials.

Inthisway,thefilterhousing which is itself pro tectedfrom vibrations constitutes a sound deadening casing forthe filter element with the help ofwhich optimum sound damping is achieved at the inlet for the combustion air.

The mounting of the elements ofthe airfilter may be effected in various ways adapted to various types of engine. A simple form of construction is achieved if the wall constituting the filter housing is carried by the same component of the engine casing asthefilter element is also secured to. In this respect it is espe ciallyadvantageousto use as that component the air inlet duct ofthe cylinder head ofthe engine.

However, the wall constituting the filter housing may be secured to one component of the engine casing whilstthe filter element is carried by another component ofthe engine. In such an arrangement the filter element is preferably secured to a wall ofthe air inlet duct of the cylinder head ofthe engine, the wall forming thefilter housing being constituted byat leasta partofthe sound-deadening cowling which surrounds the engine casing and mounted on the engine casing with the interposition of sound damping materials.

Advantageously, the arrangement can also be formed in such a way thatthe wall surrounding the filter element also encloses other components of the engine.

In the following description embodiments ofthe invention are described by way of example with referenceto drawings in which: Figure lisa side view, partly in section of a first example in which both component parts ofthe air filter are mounted on the same component ofthe engine; Figure2 is a similarview of a second example in which the elements are mounted on alternative components of the engine; Figure 3 is a cross-section on the line A-A of Figure 2; and Figure4is a cross-section on the line B-B of Figure 2.

Thefirstembodimentshown in Figure 1 shows a vertically arranged cylinder 10, only part of which is illustrated, and in which a piston 12 is movable upand-down. In the cylinder head 14 mounted on the cylinder 10 are housed the two valves as well as their operating members. Only the inlet valve 16 is shown in full whereasjust partofthe outlet valve 18 is illustrated. The valve 16 controls the connecting duct between the operating chamber in the cylinder 10 and the inlet channel 14a in the cylinder head 14. Acover 20, only part of which is shown seals offthevalves andtheiroperating members from above.

Avertically arranged flange 14bofthecylinder head 14is provided for mounting the airfilterforthe combustion airofthe internal combustion engine.

The filter element itself consists of a horizontally arranged cartridge 22 madeoffilterpaperorthelike which is combined with two mounting discs 24 and is secured to the cylinder head 14 by means of a securing cover 26 and a bolt 28 which is engaged in the cylinder head. The filter cartridge 22,24 is in contact with a ceramic ring 30 let into the cylinder head 14, 1 4a to provide heat insulatidn between the cylinder head and the airfilter. Thefilterelement itself 22 is surrounded bya horizontally arranged filter housing 32 in the shape of a pot so thatthere is an air gap on all sides between the filter cartridge and thefilter housing. Preferably, the housing 32 is made from sheet metal and has an air inlet port 32a.Around the open end ofthefilter housing 32 are secured a number of fixing lugs 32b. In each fixing lug an aperture is provided fora fixing bolt 34 which engages in a screw threaded hole in theflange 14b ofthe cylinder head 14. Between each bolt 34 and the associated fixing lug 32b is located a sealing washer 36 made of resilient, vibration-damping material, for example rubber. A furthersealing ring 38 is located between the end face 32cofthe housing 32 and the flange 14b ofthe cylin- derhead 14.

It is clearthat in this way no direct contact (material contact) occurs in the connection between the filter housing 32 and the cylinder head 14 but ratherwith the help ofthe resilient elements 36,38, a connection is established which strongly dampsthetransmission of vibrations in the material. In this way, the vibrations which, in operation, originate from the stronglyvibrating engine casing will only reach the filter housing 32 after being very well damped so that the emission ofsoundfrom thefilter housing into its surroundings is extremely small. This therefore re- sults in a zone with a very low noise level in the region around the airfilter.

In the embodimentjust described the filter element and its housing are both carried by the same componentofthe engine, namelythe cylinder head. It is howeverpossibleto mountthefilterelementonone componentofthe engine and to mountthefilter housing in another suitable engine component with the interposition of vibration damping materials.

In the second embodiment according to Figures 2 4there is shown an arrangement in which a cowling which surrounds the engine casing to provide sound insulation also serves in part as a wall forthefilter housing.

An inlet duct 120 forthe combustion air is secured by a numberof bolts 1 18to an approximatelyvertical flange 1 14b ofthe cylinder head 114, and an upper horizontal flange 120a ofthe inlet duct 120 serves for mounting the horizontally disposed ring-shaped filter element, that is the filter cartridge 222 and its supporting parts 224,226,228.

Inthiscase,theinternal combustion engine issurrounded bya sound deadening cowling comprising a number of parts made of sheet metal orthe like. This cowling is carried by a supporting plate 140 which is clamped between the cylinder 10 and the cylinder head 1 14, for example in the manner described in the United Kingdom patent specification no.1443276. Its vertically disposed covers 142 and 144 and the upper horizontal cover 146, together with other covers which are not illustrated, completely shield the engine casing from outside.

A horizontal rectangular cover plate 160 is located between the covers 142 and 146 and is secured by means of a number of snap closures 162 and seals 164,166. This cover plate 160, when opened, allows free access to the airfilter 222 which is necessaryfor servicing.

An apertureforthe inlet duct 148forthecombus- tion air is provided in the cover 144 (as shown in Figure 3) and the inlet duct is surrounded by a rectan gularlyshaped housing 150. The parts 148 and 150 are secured to one another and to the cover 144 in a suitableway,forexample by means of adhesive. The vertical wall 1 50a ofthe housing 150 which is directed towards the filter element 222 is formed like a sieve with numerous holes which serve as a coarse filter for dirt particles in the combustion air. The rectangularly shaped housing 150 servestogetherwith the inlet duct 148 as additional sound dampingforthecom bustion air.

Theverticalwall 152 (Figure 3) is secured insidethe engine cowling. Itextends from the uppercover 146 to the supporting plate 140 on which it rests with the interposition ofa sealing ring (notshown). In addition it lies againstthefloor 150b' ofthe housing 150.

Afurthervertical wall 154 (Figure 4) runs parallel to the cover 142, surrounds the flange 1 14b ofthe cylin der head 114 in horseshoe fashion, rests, with inter position of a sealing ring 156, on the peripheryofthe cylinder head 114, and extends to the supporting pIatel4O.Thewall 154hasanumberoflugs154a whichserveforsecuring it to the housing 150.

In this way, the space 158 surrounding thefilter element 222 is completely separated from the space insidethe engine cowling. Intothisspaceisleadthe combustion airentering through the inlet 148, as indicated bythe arrows shown in Figures 2-4. After passing through the filter element 222 the combustion air next reaches the inlet duct 120 and then the inletvalveinthecylinderhead 114.

Cooling airforthe engine is forwarded through the space within the engine cowling by a blower and after passing through the cowling leaves it again through an outlet opening, as indicated, for example, in the aforementioned United Kingdom patent specification no. 1443276. However, because the space 158 is com pletely closed off, this cooling air cannot mix with the combustion air moving to the filter element 222.

It isclearthat in the second embodiment as well the same optimum isolation ofthe airfilterfrom sound vibrations is achieved as in the first embodiment by separating the filter housing from the actual filter element, as shown, and by mounting the filter housing on the cowling which is secured on the engine so as to be isolated from its sound vibrations. Since the inlet duct 120 ofthe cylinder head 114 is also located in the enclosed space 158 surrounding the filter element 222 the vibrations which issue fro it as sound waves are also strongly damped by the filter housing.

(140,142,144,150,152,1 54,160).

ltshouldalso be mentioned that all thesealing elements provided for the resilient noise deadening mounting ofthefilter housing in both embodiments are located on thefresh airside,that is on the inlet side ofthe actual filter element. Should the resilient seal become ineffective at one place or another after a long period of use, the airwhich enters there cannot gain direct entry into the cylinder head. Any airwhich mayenterthrough unsealed places must in any case first pass through thefilterelement in order to gain entry to the inlet duct in the cylinder head and,furth er,totheworking space in the cylinder. Thus, the engine only ever receives filtered combustion air so that possible damage as a result of unpurified combustion air in the engine cannotarise.

Finally, it should also be mentioned that thefilter housing could be mounted separately from the filter element, on another component of the engine, for example on the base of the engine, and isolated in a similarwayfrom vibrations.

Claims

1. An airfilter arrangementfor internal combustion engines in which the air filter comprises afilter element and a filter housing which surrounds the filter element and incorporates the air inlet, wherein the filter element is carried by a supportwhich is directly secured to a wall oftheenginecasing,the filter housing being formed by at least one wall which is separate from the filter element and carried by a component of the engine with the interposition of vibration damping materials.

2. An arrangementaccordingto claim 1,wherein the wall forming the filter housing is carried by the same component ofthe engine casing to which the filter element is secured.

3. An arrangementaccording to claim 2,wherein the component is constituted byte air inlet duct of the cylinder head ofthe engine.

4. An arrangement according to claim 1, wherein the wall forming the filter housing is secured to one component ofthe engine casing whilstthefilterele ment is carried byanothercomponentoftheengine.

5. An arrangement according claim 4, wherein the filter element is secured to a wall ofthe air inletductof the cylinder head ofthe enginewhilstthewall form ingthefilterhousing is constituted by at leastone part ofthe sound deadening cowling which surrounds the engine casing and is mounted on the engine casing with the interposition of vibration damping materials.

6. An arrangement according to claim 5, characterised in that the wall surrounding the filter element also encloses other components ofthe engine.

7. An airfilter arrangement for internal combustion engines, constructed and arranged substantially as hereinbefore described with reference to and as shown in the drawings.