GB2128896A

GB2128896A - Air cleaner of an internal combustion engine

Info

Publication number: GB2128896A
Application number: GB8230126A
Authority: GB
Inventors: Rudolf Natanovich Starobinsky; Mikhail Ilich Fesina; Jury Petrovich Lazarev; Evgeny Vasilievich Lysenko
Original assignee: VOLZH OB PROIZV; VOLZHSKOE OBIEDINENIE PO PROIZVODSTVU LEGKOVYKH AVTOMOBILEI
Current assignee: VOLZH OB PROIZV; VOLZHSKOE OBIEDINENIE PO PROIZVODSTVU LEGKOVYKH AVTOMOBILEI
Priority date: 1982-10-21
Filing date: 1982-10-21
Publication date: 1984-05-10
Also published as: FR2534630A1; FR2534630B1; SE8205701D0; GB2128896B; SE450722B; DE3237747A1; DE3237747C2; SE8205701L

Abstract

An air cleaner of an internal combustion engine comprises a housing 1 in the form of a round cylinder having an inlet port 2 with an air intake tube 3 secured therein, an outlet port being arranged at the bottom of the housing. Disposed inside the housing 1 coaxially therewith is a filter element 6. The centers of the inlet and outlet ports 2 and 5 are positioned in mutually perpendicular planes passing through the centerline of the housing 1, whereas the center of the outlet port 5 is offset relative to the centerline of the housing 1 a distance (0.58-0.68)R, where R is the radius of the base of the cylindrical housing 1. The invention can find application in air intake systems of most carburator engines to reduce the amount of air intake noise. <IMAGE>

Description

SPECIFICATION Air cleaner of an internal combustion engine This invention relates to the art ofengine construction, and more particularly to air cleaners of internal combustion engines.

The invention can find application predominantly in air intake systems of motorvehicle carburator engines, such as automobile, marine, locomotive engines and the like, as well as stationary engines, for example, those used to drive generators, compress ors, etc., when it is necessary to reduce the amount of air intake noise emitted into the atmosphere.

The present invention is directed toward the provision of an air cleanerwherein the amount of air intake noise is reduced by virtue of bringing down the level of noise components within a range covering the natural frequencies ofthe tangential and radial forms of oscillations ofthe air volume in the chamber ofthe air cleaner by modifying the construction ofthe air filter.

This is attained by that in an air cleaner of an internal combustion engine comprising a housing in the form of a round cylinder with an inlet port having secured thereto a n an airintaketube,a bottom ofthe housing having an outlet port, a filter element, and a filter cover, according to the invention, the centers of the inlet and outlet ports are positioned in mutually perpendicular planes passing through the centerline of the housing, the center of the outlet port being offset relative to the centerline ofthe housing.

Such positioning of the ports enables to effectively reduce the level of air intake noise at the lowerst natural tangential forms of oscillations of the air volume in the chamber of the air cleaner.

Preferably, the center of the outlet port is offset relative to the centerline of the housing a distance (0.58-0.68)R,where R is the radius ofthe housing.

This affords effective suppression of air intake noise atthelowerstnatural radial forms of airvolume oscillations in the chamber of the air cleaner.

The invention will now be described in greater detail with reference to specific embodiments thereof taken in conjunction with the accompanying drawings in which: Fig. lisa schematic illustration of an air intake cleaner of an internal combustion engine (a side view); Fig. 2 shows a top plan view of Fig. 1; Fig. 3 represents pressure distribution curves in the chamber ofthe air intake cleaner according to the invention at the lowerst natural tangential forms of oscillations; Fig. 4 shows a pressure distribution curve in the chamber of the air cleaner at the lowerst natural radial forms of oscillations; and Fig. 5 illustrates a noise spectrogram made in the course of comparative tests of the prior art device and the device according to the invention.

An air cleaner of an internal combustion engine (Fig.

1 ) comprises a housing 1 in the form of a round cylinder having an inlet port 2 whereto there is attached an air intake tube 3 (Fig. 2). A bottom 4 (Fig. 1) of the housing 1 is provided with an outlet port 5, whereas arranged coaxially relative to the housing 1 is a filter element 6 (Fig. 2). The housing 1 is capped by a filter cover 7 (Fig. 1). The centers ofthe inlet and outlet ports 2 and 5 (Fig. 2), respectively, are disposed in mutually perpendicular planes passing through the centerline ofthe housing 1 (Fig. 2), the centerofthe outlet port5 being offset relative to the housing 1 a distance (0.58-0.68)R, where R is the radius ofthe base ofthe round cylinder making up the housing 1.

The aircleaner of an internal combustion engine with reference to Figs. 1 and 2 operates in the following manner.

At the moment of opening/closing of the inlet valves and in the course ofcylinderdisplacementvariations an accompanying variable component ofthe volumetric consumption of air results in "swinging" ofairvolumes enclosed in various elements of conduits and other volumes ofthe air intake system.

The air volumes in various elements of the system have certain frequency characteristics, particularly natural oscillation frequencies adapted to "transform" the action imparted thereto according to their own frequency characteristics,to finally determine the noise produced bytheopen endoftheairintaketube 3. The volume ofthe air column contained in the housing 1 may be viewed as a distributed (by volume) mass posessing certain resilient, inertial and dissipative characteristics. Agitation of this mass is effected through the outlet port 5.By virtue of the aforesaid agitation, the airvolume contained in the housing 1 starts to oscillate at natural frequencies which enhances swinging ofthe air column contained in the air intake tube 3 atthesefrequencies and amplifies the intensity of noise produced by the open end of the air intake tube 3. Experiments have shown that most intensive are oscillations of the ain column contained in the housing 1 atthelowersttangential and radial forms of oscillations, which are characterized by clear-cut maximums (antinodes) and minimums (nodes) of pressure.The arrangement ofthe outlet port 5 at a distance of 0.63 R from the geometrical center of the cylinder corresponds to placing it on the nodal line ofthe lowerst radial form of oscillations, which actsto reducetheswinging of the airvolumeat these oscillations. The arrangement of the inlet port 2 on the nodal line ofthe lowersttan gential form of oscillations results in afailureto transmit energy to the air column enclosed in the air intake tube 3 whereby transmission of these oscillations from the housing 1 to the air intake 3 is prevented, which in turn prevents amplified noise at this frequency.

Calculations and experiments into the distribution of pressure fields in the housing 1 ofthe air cleaner have shown thatthe lowerstforms of natural pressure oscillations ofthe volume of the housing 1 have the form of cosinusoids, more precisely Bessel's functions (Fig. 3) with a maximum pressure at the side wallsofthehousing 1 oftheaircleanerina plane passing through the centerline of the housing 1 (Fig. 2) and the center of the outlet port 5. As best seen in Fig.

3, at radii which are perpendicularto a straight line connecting the centerline ofthe housing 1 (Fig. 2) with the center of the outlet port 5 nodal or zero points are disposed. This signifies the advisability of connecting the inlet port 2 (Fig. 1 ) ofthe air intake tube 3 (Fig. 2) to these zero or minimum value zones in order to maximize the transmission of pressure oscillations in the chamber (atthe lowerstforms oftheir natural oscillations) into the air intake tube 3 (Fig. 2) the open end of which is in factthe source of acoustic energy.

From the analysis of pressure distribution curves in the housing 1 of the air cleaner at the lowerst natural radial forms of oscillations (Fig. 4) it follows that the nodal zones are disposed circumferentially having a center coinciding with the geometrical center of the housing 1 and a radius r = 0.63R, where R is the radius ofthecylindrical housing 1 of the air cleaner.

The distribution of pressure fields in the housing 1 at such aform of oscillations follows the Bessel's function ofthefirsttype: F P i;o (3.83 R ), where P is the pressure in the radial form; r is the current radius; and R is the radius of the housing 1.

In this case zero values of pressure are obtained at r = 0.63R (i.e., the nodal lines are formed at r = 0.63R).

As can be seen from the curve shown in Fig. 4, sufficiently small pressure values are maintained at r = (0.58-0.68)R, which enables to take into account and compensate for certain amount of"deforamtion" ofthe pressure curve from the assymetrical location of the outlet port 5 at the bottom 4 of the air cleaner.

It is important to consider the location of the two ports 2 and 5 in the housing 1 (Figs 1 and 2) ofthe air cleanertaking into account other factors. Forexam- ple, agitation and transmission ofthe lowersttangential forms of oscillations may be precluded (or significantly weakened) at any disposition of the air intake tube 3 in the housing 1 in the case when the outlet port 5 is located in the geometrical center of the housing 1. However, this entails a very active passage (exitation,transmission and radiation) ofthe lowerst form ofthe radial oscillation as best seen in Fig. 4.

In view ofthe aforegoing, in order to suppress these two forms of oscillations, it is necessary to strictly correlate the interposition of the ports 2 and 5 in the housing 1 of the air cleaner, as has been mentioned earlier.

The results of studies carried out versus the closest prior art device are represented in Fig. 5.

Thefull line curve (a) shows the noise spectrum of the prior art device, while the broken line curve (b) illustrates the noise spectrum for the proposed construction.

The arrangement of the inlet port 2 (Fig. 1 ) in the nodal line of resonance tangential oscillations of the air volume in the housing 1 enabled to preventthe passage of these oscillations to the air intake tube 3 and eliminate intensive noise radiation produced by the tube 3 at frequencies of between 630 and 800 he to 9dub. The efficiency of intake noise suppression by the herein proposed air cleaner is represented by the hatched area in the spectrum.

The object of the invention is therefore attained as described above.

Claims

1. An air cleaner of an internal combustion engine comprising a housing in the form of a round cylinder having an inlet port with an air intake tube secured therein, the housing being provided with a filter cover; the bottom of the housing having an outlet port, while disposed inside the housing coaxially therewith there is provided a filter element; the centers of the inlet and outlet ports being positioned in mutually perpendicular planes passing through the centerline of the housing, the center of the outlet port being offset relative to the centerline ofthe housing.

2. An air cleaner of an internal combustion engine substantially as heretofore described with reference to the accompanying drawings.

2. An air cleaner of an internal combustion engine according to claim 1 wherein the center ofthe outlet port is offset relative to the centerline ofthe housing a distance (0.580.68)R, where R is the radius of the base ofthe round cylinder.

3. An air cleaner of an internal combustion engine substantially as heretofore described with reference to the accompanying drawings.

New claims or amendments to claims filed on 15 December1983 Superseded claims 1-3 CLAIMS

1. An air cleaner of an internal combustion engine comprising a housing in the form of a round cylinder having an inlet port with an air intake tube secured therein,the housing being provided with afilter cover; the bottom ofthe housing having an outlet port, while disposed insidethe housing coaxially therewith there is provided a filter element; the centers ofthe inlet and outlet ports being positioned in mutually perpendicular planes passing through the centerline ofthe housing, the center of theoutlet port being offset relative to the centerline ofthe housing by a distance (0.58-- 0.68)R, where R isthe radius ofthe base ofthe round cylinder.