US2340152A - Air cleaner and silencer - Google Patents

Description

Jan. 25, 1944. a. STEENSIEN 2,340,152

AIR CLEANER AND SILENCER Filed Nov. 4. 1940 !NVENTOR 38)?2474 52 88475 9);

fi M, Mill, Wm *M ATTORNEYfi- Patented Jenzs, 1944 2,340,152

UNITED STATES PATENT OFFICE AIR CLEANER AND SILENCER buretors in which the silencer comprises a closed vessel so arranged that oil cannot be pulled over from the oil bath into the silencer as in prior arrangements. The advantages of the present invention include cleanliness and the elimination Bernard Steensen, Detroit, Mich assignor to Chrysler Corporation, Highland Park, Mich, a corporation oi Delaware Application November 4, 1940, Serial No. 364,113

2 Claims. (Cl. 183-15) The present invention relates to a device for of'a fire hazard since any oil which might be cleaning the air being taken into a carburetor, pulled over from the oil bath is drawn directly particularly of the downdraft type, and for silencinto the engine cylinders and burned. ing the noises emanating from the intake of an A further advantage of the present arrangeengine as well as produced by the passage of thement over prior known arrangements. such as air through the cleaner and into the carburetor. horizontal in-line positioning of the cleaner and It is an object of the present invention to provide silencer, or other known prior arrangements, is I a carburetor air cleaner and silencer which 00- the elimination of vibration breakage since the cupies a minimum height above the carburetor only overhanging part is of light but rigid conwith which it is associated so as to reduce the 1 struction. v minimum under-hood height requirements. This An additional object of the invention is the object is principally achieved by arranging the provision in an air cleaner and laterally oifset air cleaner vertically above the air intake of the silencer assembly of a connecting throat between carburetor and arranging a silencer laterally of the cleaner and silencer portions which is so dithe body ofthe air cleaner instead of in line mensionally predetermined with respect to the therewith as in prior practice. The advantages volume of the silencer as to serve as the attenuof such an arrangement include not only the reating means thereof, thus obviating the necessity duction of height of the carbiu'etor assembly but of a separate and additional member for accomthe permission of larger silencers having greater plishing this purpose.

effect than those heretofore possible. A still further object of the invention is the A further object 'of the present invention is to provision in an air cleaner and silencer assembly provide an air cleaner and silencer comprising of this kind of a fire screen to prevent igniting an open conduit leading directly into the intake of any fuel mixture which gains access to the tube of the carburetor and extending coaxially silencer under certain operating conditions of an 7 thereof so as to eliminate elbows and bends which engine. 7 tend to cause unequal distribution of the air and These and other objects and advantages of the fuel mixture to the branches of the engine intake present invention should be more apparent from manifold. The advantages of the present inven-p a study of the following specification taken in tion are: increased freedom of air travel due to connection with the accompanying drawing the elimination of the elbows and other restric- 'm wherein like numerals refer to like parts through-. tions heretofore thought necessary, improved disout. tribution of fuel mixture into the engine intake In the drawing, I manifold due to the straight flow of air concen- Fig. 1 is a. viewin elevation of an internal comtrically into the intake tube of the carburetor, bustion engine having the present invention apand improved carburetor performance due to the 3.", plied thereto; concentric flow of air through the Venturi throat Fig. 2 is a vertical section through the air of the carburetor. cleaning device and silencer of the present in- A particular advantage resulting from the presvention; ent invention is that the use of oil bath filtering Fig. 3 is a fragmentary sectional view of a devices is greatly increased. Such oil bath demodified form of the invention; vices require more vertical height than dry filters The present invention is adapted to be assobut are far more efficient in removing dust and ciated with an internal combustion engine Hi other foreign material fromthe air so that the comprising intake manifold II and exhaust maniuse thereof is of great advantage. The present fold l2 and a downdraft carburetor l3 having an invention permits the use of an oil bath filtering air intake tube It incorporated therein. The air device in an automobile having under-hood clear cleaner preferably comprises a stamped intake height arranged for a dry filter due to the offset chamber [5 which is divided into upper and lower lateral arrangement of the silencer. portions by an oil holder l6 adapted to hold a A further object of the present invention is to supply of oil therein. The bottom wall of the inprovide a silenced, oil-bath air cleaner for carso take chamber I 5 is provided with a concentric opening I! and protruding neck i8 adapted to be clamped onto the top of the intake tube H by a clamping device I9.

The upper extremity of the wall of the intake chamber I5 is provided with a. plurality of air collecting ports 20 located above the oil holder l8. and the wall terminates in an annular flange 2|. The intake chamber is adapted to be closed by a dome-shaped cover 22 having its edge crlmped over and retaining a filter holding device comprising a depending flange portion 23 and upper and lower retaining grids 24 and 25, respectively, suitably attached to the upper and lower edges of the flange portion 23. The grids of the intake chamber l5 by means of a bolt 28 having a winged head 29, the lower end of which is threaded into a member 30 traversing the opening 1.

The tube 26 forms an open conduit concentrically aligned with the intake tube I, the lower end of the tube terminating centrally of the lower open portion of the intake chamber I I so as to be spaced from the upper end of the intake tube H. The lower portion of the wall of the intake chamber I5 is provided with an opening 35 surrounded by a protruding fiange 3B, and a silencer comprising a closed vessel 31 is associated with the intake chamber by welding neck I: thereon to the flange 36. The flange 35 and neck 38 constitute a restricted connection generally designated by the numeral 38' between the interior of the silencer 31 and the space surrounding the passage from the air cleaner through which air is supplied to the engine. The silencer 21 is preferably cylindrical, and the neck 3| and fiange 3! are are also preferably cylindrical for ease of manufacturing and assembling. It may be seen that the silencer comprises a very light shell of rigid construction which maybe rigidly united to the air cleaningdevice and may be of considerable size without requiring an increase in underhood free height. 7

Engine air intake silencers have heretofore been provided with an attenuating passage or passages which have for their sole purpose the function of eliminating the objectionable eifects of sounds having wave length within predetermined limits which have been found to be particularly disturbing. Such attenuating passages are so predetermined in length and cross sectional dimensions with respect to the volume and dimensions of the silencer as to cause the sound wave reflected by the silencer to occur in an out-of-phase relationship with respect to the original sound waves emanating from the engine.

When the silencer is laterally offset as illus-' trated in the drawing, the restricted connection 38' between the silencer 31 and the space surrounding the passage from the air cleaner may be relied upon to provide the attenuating passage. This connection 38' is accordingly so predetermined in length and cross sectional dimensions with respect to the volume of the silencer 31 as to cause the sound waves reflected by the silencer to occur in an out-of-phase relationship with respect to the original sound waves emanating from the engine the objectionable effect of which it is desired to mitigate.

' While there has been devised,- and may be employed, mathematical formulas for calculating the dimensions or attenuating passages of this character, satisfactory results are, in actual practice, obtained by trial and error methods. In the latter way, an air cleaner and silencer assembly may be accurately constructed to eliminate the objectionable sound waves emanating from an internal combustion engine of predetermined design and duplications of the assembly will serve for all engines of the same design. The restricted connection 38' thus serves the dual function of communicatively connecting the silencer with the engine inlet air passage and attenuating sound waves of a selected range thus obviating the requirement of an additional member to accomplish the latter purpose.

The present invention, when in operation, causes air to pass through a labyrinth including the openings 20, the space between the fiange portion 23 and the shell of the intake chamber, across the surface of the oil in holder l6 and through the interstices of the filtering material 21, then into the upper end of the tube 28. The filtering material 21 is impregnated or coated with oil which is carried from the sump It by the air stream which passes through the filter so as to increase the filtering efiiciency of the device. Most of the heavy particles of foreign matter, such as dust and grit will be trapped in the oil held in the holder I8, and those finer particles which might fiow across the surface of the oil and upward with the airstream will be trapped by the coated filtering material. A substantially equal quantity of air traveling at substantially the same velocity will fiow evenly into every equal segment of the intake tube 28, and the tube 28 is of considerable length so that the air flow therethrough tends to be further evenly distributed. The member an preferably comprises a central enlarged portion, as shown in Fig. 2, and supporting arms of small diameter (not shown) so that the air flow into the intake tube It is not disturbed thereby.

It may be seen that it would be impossible for oil, which might be carried from the oil holder I up through the filter and down the tube 28, to

. become trapped in the silencer or vessel 31 since the particles of oil would be carried directly into the carburetor and from there into the cylinders where they would be burned.

In order to prevent ignition of fuel mixture in the silencer and consequent injury to the latter during back firing of the engine and otherunusual operating conditions thereof, a fire screen 40 of frusto-conical shape is disposed between the lower end opening of the tube 28 and the end opening of the intake tube It. This screen serves to prevent fiame propagation to the space surrounding the tube 26 as well as to the interior of the silencer 31 without obstructing the free flow of air to the engine.

In the form of the invention illustrated in Fig. 3 of the drawings, the air cleaner and silencer assembly is substantially identical to that shown in Figs. '1 and 2 with the exception that a fire screen 4| is provided across the passage of the restricted connection 38'. This serves to prevent fiame propagation into the interior of the silencer l1 and may be used alone or in combination with the screen 40 shown in Fig. 2.

Having illustrated and described the preferred embodiments of my invention, it should be apparent to those skilled in the art that the same permits of modifications in arrangement and details. All such modifications as come within the scope of the followingclaimsare considered to be a part of my invention,

I claim:

1. An internal combustion engine air supplying system including avertically extending substantially cylindrical casing comprising side, top and bottom walls, a horizontal partition in said casing between said top and bottom walls providing upper and lower chambers within said casing, said upper chamber having an atmospheric air inlet and including means for cleaning the incoming air, a clean air conduit supported by said partition extending centrally within said casing and establishing communication between said upper and lower chambers, said conduit terminating short of the bottom wall of said casing, said bot- ,tom wall having a central opening providing an outlet for said lower chamber, said opening being axially aligned with said conduit, the space between said bottom wall and the lower-extremity of said conduit accommodating lateral flow of sound waves emanating from said engine into said lower chamber, a silencer acoustically cooperating with said lower chamber comprising a casing having an end wall provided with an opening facing a side wall of said lower'chamber, said silencer casing having its longitudinal axis extending horizontally from said lower chamber and including an impervious opposite end wall 'and impervious side walls, said lower chamber having an opening in its side wall registering with the opening of said silencer end wall and having relationship with respect to the original sound waves emanating from the engine.

, 2. An internal combustion engine air supply-- system including a vertically extending substantially cylindrical casing comprising side, top and bottom walls, a horizontal partition in said casing between said top and bottom walls providing upper and lower chambers within said casing, said upper chamber having an atmospheric air inlet and including means for cleaning the incoming air, a clean air conduit supported by said partition extending centrally within said casing and establishing communcaton between said upper and lower chambers, said conduit terminating short of the bottom wall of said casing, said bottom wall having a central opening providing an outlet for said lower chamber, said opening being axially aligned with said conduit,

the space between said bottom wall and the lower cooperating with said lower chamber comprising a casing having an end wall provided with an opening facing a side wall of said lower chamber, said silencer casing having its longitudinal axis extending horizontally from said lower chamber and including an impervious opposite end wall andimpervious side walls, said lower chamber having an opening in its side wall registering with the opening of said silencer end wall and having a substantial portion of its area horizontally aligned and in direct unobstructed sound wave communication with the space in said lower chamber between said bottom wall of said casing and the lower extremity of said conduit, a sleeve rigid with and extending between said air cleaner and silencer casings and communicating with the registering openings thereof, said sleeve having a sound attenuating passage therethrough so predetermined in length and cross sectional area with respect to the volume of the interior of said silencer casing as to cause the sound waves reflected by the silencer to occur in out-of-phase relationship with respect'to the original sound waves emanating from the engine, and a tubular fire screen concentric with said conduit and extending between the lower end of the latter and the bottom wall of said air cleaner casing for protecting the interior of said air cleaner casing as well as said silencer.

BERNARD s'rEENsEN.

Images