US3029895A - Muffler structure - Google Patents

Description

April 17, 1962 G. A. LYON MUFFLER STRUCTURE Filed March 12. 1958 2 Sheets-Sheet l G'eorye fl/er/ Lyon April 17, 1962 G. A.LYON

MUFFLER STRUCTURE 2 SheetsSheet 2 Filed March 12, 1958 fEYI Efl frzr' Geo/ye fl/ber/ Lyon United States Patent() Y 3,029,895 MUFFLER STRUCTURE George Albert Lyon, Detroit, Mich., assignor to Lyon Incorporated, Detroit, Mich., a corporation of Delaware Filed Mar.'12, 1958, Ser. No. 720,944 13 Claims. (Cl. 181--44) The present invention relates to improvements in mufilers and more particularly muflders of the type that are adapted for use between the exhaust manifold of explosion type internal combustion engines and an exhaust tail pipe.

An important object of the present invention is to provide an improved mufiler structure which is adapted to be made in relatively small sizes but is endowed with large sound damping, explosion mufilin-g capacity.

Another object of the invention is to provide an improved muffier structure embodying a comparatively simple construction of a minimum number of standard ized parts.

A further object of the invention is to provide a muiller structure having an improved flow pattern minimizing accumulations of condensate and thus reducing the susceptibility of corrosion deterioration.

Still another object of the invention is to provide an improved mufiler construction which because of economical structure encourages the use of higher grade, more corrosion resistant materials.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of certain preferred embodiments-thereof taken in conjunction with the accompanying drawings, in which:

. FIGURE 1 is a longitudinal axial diametrical sectional detail view through a mufiler structure embodying features of the invention;

FIGURE 2 is a fragmentary longitudinal axial diamet- 3 through one of the sound muffling bafldcs showing steps in the making thereof;

FIGURE 8 is an assembly view of various components of the muflier of FIGURE 6; and

FIGURE 9 is a partial transverse sectional elevational view through a muffler showing still another modification.

According to the present invention, mufiling of the normally explosive percussions of the engine exhaust is accomplished by repeatedly breaking the. exhaust stream into a large number of jet streams directed into head-on collision with one another in a restricted chamber space within which the progressively muffled exhaust stream is confined under only slight back pressure which becomes progressively less in each successive chamber until the explosive pulsations have been subdued to such a low pitch as to be below an objectionable noise level or to be substantially imperceptible within the usual hearing range. If desired, a preferred pleasant sound may be imparted to the exhaust stream by interposing resonators' in the path of the stream as it progresses through the muflder.

In the fairly simple form of 'the invention shown in portion of the casing 10 with the central offset baffle 3,029,895 Patented Apr. 17, 1962 FIGURE -1, a tubular casing 10 of suitable length and inside diameter provides a housing within which a tortuous, impulse-cancelling, but step-by-step forwardly advancing path for the exhaust gas stream is aiiorded by a coaxial series of force dissipating, impulse damping control baflies 11. At one end the casing 10 is provided with a substantial closure 12 provided with a central tubular inlet projection 13 adapted to be attached to the end of a duct leading from the exhaust manifold of an associated internal combustion engine. At its opposite end the easing 10 is provided with a separately formed and attached exhaust gas exit nozzle closure member 14 tapering toward a central tubular exhaust passage extension 15 of a diameter somewhat larger than the diameter of the inlet extension 13 and adapted to be attached to the trailing or entry end of a'tail pipe of an automotive vehicle. At its outside perimeter, the nozzle closure member 15 is provided with an axially extending annular and in this instance outwardly projecting attachmentflange 17 dimensioned to fit snugly slidably into the inner side of the open end margin of the casing 10 and to be there secured by any suitable means such as welding, riveting or the like.

All parts of the mufiier unit may be made from suitable sheet material such as stainless steel, aluminized steel, aluminum alloy, or suitable heat and corrosion resistant moldable plastic material having a satisfactory cost factor. Sheet metal has presently the advantage of economical base cost and mass production manufacturing techniques for forming the desired shapes.

Insofaras general shape is concerned, each of the series of control bafiles 11 may be identical and therefore a description of one will suflice for the remainder in this respect. Marginally, each of the bafiles is provided with an axially extending annular flange 18 of a diameter to fit in snug slidable relation within the tubular longitudinal housing portion of the casing 10. While the flange 18 may be secured to the casing 10 by any suitable means such as welding, riveting, and the like, in order to maintain a predetermined axial disposition of the respective bafile member spacer rings axially between the margins of the baffle members may be employed, or the housing wall may be dimpled at longitudinally opposite ends of the attachment flange 18 to maintain the axial position of the bafile member, or some other suitable retaining expedient may be employed to maintain the series of bafile members in predetermined spaced relationship.

Axially offset from the margin of the battle member -in each instance is a central solid baflle wall or parti- 'tion portion 19 joined integrally to the bafile margin. by

a plurality of sinuous cross-section generally accordion pleat-like open fold juncture and spacer ring ribs comprising a radially inwardly projecting rib 20 and a radially outwardly projecting rib 21 in return-bent relationship affording a common substantially radially extending intermediate wall 22 and affording an axially spaced relationship of the radially inner portion of the baffle member margin and the marginal portion of the ofiset baflle portion 19, with the intermediate wall 22 in spaced relation to each of the marginal portions. In a preferred form, the ring ribs 20 and 21 are substantially identical in radius, with the rib 20 providing a generally radially outwardly opening groove and the rib 21 providing a generally radially inwardly opening groove. The outside ring diameter of the radially outwardly projecting rib'21' is sufficiently smaller than the inside diameter of the housing portion of the casing 10 to afford a space or gap therewith at least as great as the width of the groove defined by the ring rib 20.

Each of the baflles 11 is mounted within the housing portion 19 facing toward the inlet end of the casing, and

. 3 means are provided for movement of the exhaust stream gases through and past the respective baffle members by way ofthe radially inwardly opening groove provided by the ring rib 21. To this end, the opposing generally axially facing walls defining the ring rib 21, namely the intermediate wall 22 and the opposing marginal portion of the central baffie member portion 19, are provided 7 with respective series of spaced openings 23. By having the-openings or orifices 23 in the respective series disposed directly opposite one another, the exhaust gases escaping through the openings into the channel groove of the rib 21 as jets under the explosive impulse and exhaust expansion impinge in head-on collision and by through the peripheral chamber the mouthof which is final bafiie 11 in the series the exhaust gases are subprovided by the margin of the bafile member 11a and the juncture ring rib intermediate structure of the bafiie member 11]; similarly as described in connection with the baffle member 11a. This muthing cycle is repeated progressively through the remainder of the series of baffles 11c, 11d, He and 11 until upon escaping past the stantially free from explosive impulses and while they their mutual pressure and the ensuing turbulence have c a sound damping resonance altering, explosion impulse cancelling action. The size and aggr'egate flow area of the flow controlling sets of orifices .23- are predetermined to afford as low a pressure drop'as' practicable consistent witheifectivemufiling and to maintain the back pressure load on the exhaustsystem of the engine as low as practicable.

may not be moving without any impulse, there will have been such impulse decay as to assure such'low register long wave length, flattened curve pulsations as to beaurally agreeable.

In order to implement the gradual leveling out of the exhaust impulses, gradual expansion of the exhaust gases in the tortuous passage through the muffler is afforded by havingthe collision jet orifice openings 23 of progressively: larger aggregate flow area from the first bafile member 11a to the last bafile member 11 in the series.

Cylinderdisplacernent and power of the associated eri V gine are taken into account in determining how many of the bafiies 11 will be desirable for mufiling efficiency where a single muffler is used for all cylinders or exhaust This may be effected by having orifices of the same size but gradually increasing number in the respective bafile members, or,- as shown by having the orifices of the same number in each of the bafile members but of progressively greater diameter in order to attain progressively ports of the engine. For some engines, therefore, it may be necessary to have a larger number of bafile's and therefore-a longer unit than shown in FIGURE 1, while for other engines a shorter unit with less baflles may be adequate. Where a plurality of mufiiers is used in an exhaust system of an engine, each of the mu'ffiers may be smaller than shown both as to diameter and as to number of bafiles or as to either of these dimensional and capacity factors.

In the illustrated example, six of the baffies 11 are greater aggregate flow area. In each of the between bafpurpose comprises tuning bell members 24 (FIGS. 2

shown in an equally spaced coaxial space. The first baffle 11a in the series is locatedas close as practicable to theentry end closure 12 the wall of which is preferably of a flaringform affording-with the bafiie member 11a j the mouth of a ring chamber defined about the perimeter of the ring rib 21 and Within the chamber groove of the 'ring rib 20 and thecircurnscribing casing housing wall.

As indicated bydirectional arrows as the. explosively and 3) of which there may be'one or more depending.

upon the sound level and tone quality desired. Each of the tuning bells 2'4 comprises a'genera'lly. cup-shaped member the base portion of which is constructed comple'mentai'y toand is engageable with the forwardly facing tuning hells.

impelled exhaust gases enter through the inlet 13, they tend to impinge against the central closure portion 19 of the bafhe member 11a and bounce back or atleast de flect in a radially outward direction under the pressure "of the exhaust gases advancing thereupon. At this point,

an initial minor impulse cancellation muffling action is eifectedlby having the "central offset baflie portion 19' of dished, concave form, thereby directing the impinging exhaust gases in a generally interceptingly joining relation to the peripheral portions of the exhaust gas stream that issuedirectly into the mouth of the peripheral cham' ber about the 'pe'rforatedring rib 21. By having the central baflie portion 19 of concave form, moveover,

diaphragm resonance is avoided although because of inherent resiliencein the portion 19'and the return-bent ring ribs 20 and 21 a cushioning action under the explosive impulses of theexhaust gases impinging thereagainst at? and thenmove radially inwardly uniformly from the ring chamber defined by the ring rib 21 toward the center surface of the central portion 19 of one of the baflle mom" I here 11, in this instance shownas either or both of the baflle member's He and 11 although each of the bathe members in the series may be equipped withone of the Any suitable means such as respective screws 25 are utilized to secure the tuning bells 24, con

centrically at their. centers to the baffle portions 19.. Marginally, the tuning bell in each instance is provided with a tone producing vibratory generally axially extending flange 27 which extends across the exit from the ring chamber within the associated ring rib 21 and is. of a length to lie opposite the ridge of the radially inwardly projecting ring rib 20 in ample spaced relation to avoid restricting movement of the exhaust gases'onward thereby.

In order to attain the desired tone quality from the tuning bells 24, materials and drawing or spinning techniques are selected. Over tones and tonal combinations can be attained by selection and combining of variously tuned bells in any given series.

For example, an auto-- mobile manufacturer may wish to have various models of of a control chamber defined between the baffie member v 11a and the second baffle member 1111 in the series. 'As

the exhaust gases crowd toward thecenter of this interbaffiechamber, their impulse force is further displaced The forward convex'side of thecentral portion 19 of the bafiie member 110: serves as a forwarddefiector'so that thebaffle 11b and a repetition of in inuating cycle in FIGURES 1-4.

automobile identified by the sound of the exhaust. By the described expedient, this can be attained. On theother hand, individual car owner preferences or aural identification requirements may be met;

In addition, of course, a further mufiling control factor is'i'nterposed in the exhaust gas stream where the bell members 24 are used.

Although the muffier may be made in the cylindrical.

form shown in FIGURES 3 and 4, an oval form asshown in FIGURE 5 may be provided wherein the muffler "10 has an elongated. transverse axis enabling it to, be ac: commodated in a. 10w head room clearance position. Other details of the mufiler. 10' may be the same as shown In FIGURES 6-7, a mufiler is shown which in general respects is much the same asthe muflier in FIGURE 1 both as to structure and operation but embodies a slightly different or modified bafile structure. To this end, a tubular casing 30 is provided affording an elongated housing for a series of baffle members 31. An integral inlet extension 32 is provided at one end of the casing and an attached end closure 33 is provided at the Opposite end of the casing and having an exhaust exit extension 34 coaxially disposed with respect to the casing. Attachment of the closure member 33 is by means of an axially outwardly extending peripheral attachment flange 35 dimensioned to engage within the open end margin of of the casing 30.

Each of the baflle members 31 includes a peripheral generally axially extending flange 37 dimensioned to engage and be secured, if desired, to the inside wall defining the housing portion of the casing 30. Joining a radially extending portion of the battle member 31 in each instance to a central solid offset portion 38 is a generally accordion pleat, sinuously cross-sectioned return-bent fold juncture structure including a radially inwardly projecting ring rib 39 and a radially outwardly projecting ring rib 4t) affording a common generally radially extending wall 41 therebetween. The wall 41 and the overlying opposite wall of the ring rib ,40, also constituting the marginal portion of the offset central bafiie member portion 38 are provided with opposed circumferentially spaced series of exhaust gas escape orifices 42 through which the exhaust gases escape in head-on colliding jet streams similarly as hereinbefore described.

In this instance, however, the central bafile portion 38 is dished to a greater extent than is the case with the central portions 19 of the baffles 11. Thereby, a ring shoulder 43 is provided on the dished portion 38 opposing the radially inwardly projecting ring rib 3 9 in spaced control gap relation. Through this arrangement, the exhaust gases after head-on collision impingement of the small streams or jets escaping through the opposed orifice apertures 42 into the chamber provided within the ring rib 40 are directed to flow in a more or less controlled radially inwardly and axially forward direction toward and into the relatively deep depression afforded by the opposing centralbafiie portion 33 and thus tending to develop a more or less swirling turbulence within the between bafiie chamber that leads peripherally to the peripheral ring chamber about the ring ribs 39 and 40 of the next adjacent baflie in the series. For some purposes this form of bafiie structure and arrangement may have improved muffling characteristics.

in making the battle members 31, a generally cup shaped shell is drawn or spun including the peripheral attachment flange 35 and a smaller diameter axial wall flange W of a diameter substantially midway between the ridge diameters of the radially inward ring rib 39 and the radially outward ring rib 40. Then the axial wall W is collapsed under controlled conditions to provide the sinuous accordion pleat-like folds to afiord the open groove ring ribs 39 and 40, with the ring rib 39 bent toward the inner sideof the axial plane of the wall W and the ring rib 40 bent toward the outer side of such plane. After the ring ribs have been bent to form, the orifice apertures 42 are drilled coaxially through the opposing spaced walls defining the rib ring 40.

It will be understood that the method of making the bafiie members 41 may be utilized in making the baffle members 11 as Well.

In FIGURE 8 is depicted the manner'of assembly of the muffler of FIGURE 6, although the same method of assembly is employed in assembling the muffler of FIG- URE 1. Each of the baflle members 31 is successively inserted into the housing portion of the casing 30 and secured in its proper spaced relation to the next preceding one of the bafile members 31. Finally the end closure exhaust outlet member 33 is inserted in place within the end margin of the casing 30 and secured in place to complete the unit. After the unit has been assembled, suitable external finish may be applied if desired.

Instead of a single circumferentially spaced series of exahust escape jet orifices at each side of the jet impingement, impulse cancellation chamber ring rib, a plurality of series of apertures may be provided as shown in FIG- URE 9 wherein the mufller may in other respects comprise structure similar to the muffler 0r FIGURES 1 and 6. To this end, a muflier having a casing 45 has bafiie members 47 therein each having a radially outwardly projecting ring rib 48 affording a chamber into which open a plurality of series of exahust escape jet apertures 49 coaxially aligned on each side of the ring rib. It will be understood, of course, that as many or as few of the apertures 49 may be used in all or selected ones of the battle members, or there may be a selection or particular order of bafiie members some of which have a single series of apertures while others have two or more series, as may be worked out to take care of particular requirements for operating conditions.

It will be understood that modifications and Variations may be etfected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In a mufiler structure wherein a casing provides a housing with an inlet and an outlet, a bafile member for disposition within and across the housing, said baflle member including a perimeter for attachment to the housing and a central portion joined to a marginal portion by an intermediate offsetting generally accordiion pleat-like plurality of radially inwardly and radially out wardly directed return-bent ring ribs having a common wall, one of said ribs having through the opposed walls thereof generally opposed orifices through which exhaust gases are adapted to issue in head on collision within the chamber provided by said rib.

2. In a muflier structure, an elongated casing having one end portion thereof constricted and providing a tubular inlet and the other end portion thereof normally open, a generally funnel-like discharge nozzle closing said normally open end, and a plurality of longitudinally spaced baflies in said casing between said inlet and said discharge nozzle, said baflies having centrally offset portions with intermediate connecting reverse bend ring ribs with flow control orifices therethrough, said offset portions and said ring ribs coacting to afford muflle cushions.

3. In a muflier bafile structure, a sheet metal piece of generally cup shape, the margin of the cup being of a perimeter of substantially greater diameter than the wall of the cup, the wall of the cup comprising radially inwardly and radially outwardly projecting ring ribs of smaller diameter than said perimeter, and perforations in the walls defining one of said ring ribs providing opposed iet orifices.

4. In a muffier structure, means providing a housing having an inlet and an outlet and a bafiie disposed within saidhousing between said inlet and said outlet, said bailie interrupting flow of fluid from the inlet to the outlet, said baffie having a ring rib thereon which projects from the inlet side of the battle and defines a chamber which opens toward the outlet side of the baffle, said rib having a pair of opposed ring walls, each of said walls having a series of orifices therein, the orifices of said walls being in respectively generally opposing relation to each other and defining jet streams of fluid moving from said inlet through said orifices to collide head-on in said chamber and then move from the opening of the chamber toward said outlet.

5. In a mufiler structure, means providing a housing having an inlet and an outlet and a bafiie disposed within said housing between said inlet and said outlet, said bafiie interrupting flow of fluid from the inlet to the outlet, said bafile having a ring rib thereon which projects from the inlet side of the balile and defines a chamber which opens toward the outlet side of the bafile, said rib having a pair of opposed ring walls, each of said walls having a series of orifices therein, the orifices of said walls being in respectively generally opposing relation to each other and defining jet streams of fluid moving from said inlet through said orifices to collide head-on in said chamber and then move from the opening of the chamber toward said outlet, the openinglfrom said ring rib chamber defining a mouth directed generally toward the axis of the housing whereby the fluid leaving the mouth converges toward said axis.

6. In a mufiier structure, means providing a housing 7 having an inlet and an outlet and a baflle disposed within said. housing between said inlet and said outlet, said bafiie interrupting flow of fluid from the inlet to the outlet, said bafllehaving a ring rib thereon which projects from the inlet side of the bafile and defines a chamber which opens toward the outlet side of the baffle, said rib having a pair of opposed ring walls, each of said walls having a series of orifices therein, the orifices of said walls being in respectively generally opposing relation to each other and defining jet streams of fluid moving from said inlet through said orifices to collide head-on in said chamber and then move from theopeniug of the chamber toward said outlet, said housing having therein between said baffle and said outlet a second baflle defining withthe first mentioned bafile achamber into which thefluidfrom said ring rib chamber issues, said second baflle having orifice means therethrough'through which the fluid from :the chamber between the baflies must pass in controlled relation toward said outlet. i

7. In a muffler structure, means providing a housing having an inlet and an outlet and a baflie disposed within said housing between said inlet and said outlet, said bafiie interrupting flow of fluid from the inlet to the outlet, said siliently flexible material and having a marginal portion in the .form of an accordion pleat-like plurality ofradtally inwardly and radially outwardly directed return-bent ring ribs having a common wall, said ring ribs being re- 4 siliently yieldable in response to impingement of fluid from said-inlet against said baflle member, said marginal portion having fluid controlling openings therethrough by which fluid passes from the inlet sidetothe outlet side of the baflle to move toward said outlet.

10. In a muffler structure including means defining a rhnfile chamber having inlet and outlet ends and a plubafiie having a ring rib thereon which projects from the inlet side of the battle and defines a chamber which opens toward the outlet side of the bafile, said rib having a pair of opposed ring walls, each of said walls having a series of orifices therein, the orifices of said walls being in respectively generally opposing relation to each other and defining jet. streams of fluid moving from said inlet thorugh said orifices to collidehead-on insaid chamber and then move from the opening of the chamber toward said outlet, said ring 'ribbeing disposed on amargihal portion of said baflie and comprising an accordion pleatlike fold defining a perimeter of. smaller diameter than said housing, the opening from said ring rib chain er. defining a month which opens towardthe axis of the housing.

8. in a mufller structure, means providing a housing said housing between said inlet and said outlet, said baflle interrupting flow of fluid from the inlet to the outlet, said bafile having a ring rib thereon which projects,

from the inlet side of the bafl ie and defines a chamber which opens toward the outlet side of the baflle, said rib having an inlet and an outletand a bafile disposedwithin having a pair of opposed ring walls, each of said walls 7 having a series or" orifices therein, the orifices offsaid walls being in respectively generally opposing relation to each other and defining jet "streams. of fluid moving.

from said inlet through said orifices to collide head-on in said chamber and'then move from the opening of the chamber toward said outlet, said ring rib being disposed 1, said jet orifices and provides jets of the fluid .which col- 4 on a marginal portion-of said baflle and comprising an aecordion pleat-like fold defininga perimeter of smaller diameter than said housing, the opening from said ring rib chamber defining a mouthwhich opens toward the axis of the housing, and a tuning bell member secured to the outlet side of said baffle andhaving flange s'truc-.

ture disposed in the path of fluid issuing from said mouth so that suchfluid will impinge againstsuch flange structure for development of predetermined tone response.

9. In a muffler structure comprising means providing. a housing with an inlet and an outlet and a battle mem her disposed within and across the housing between said inlet and said outlet, said baflle member comprising rerality of bafiies transversely across the muflie chamber, each of said bafiies having a marginal corrugation-like ring rib projecting generally toward the inlet and providing a groove chamber opening toward theoutlet, the side walls defining. the ribs being in substantially parallel adjacent spaced relation and having opposed orifices through which fluid to be mufiled from the inlet side of each of the baflles passes to the outlet-side thereof in jets that collide head-on within the groovechambers of the ring ribs. a I

11. In a mufller structure including means definmg a muiile chamber having inlet and outlet ends and a plurality of battles transversely across the muflie chamber,

each of said baflles having a marginal corrugation-like ring rib projecting generally toward the inlet and providingja groove channel opening toward the outlet, the side walls defining the ribs having opposed orifices through which fluid to be muflled from the inlet side of each of the bafiies passes to the outlet side thereof in jets that collide head-on within the groove channels of the ring ribs, said baflies having means for diverting the fluid passing from the rib groove channels transversely rela- 'tive to the axis of the mufile chamber. 35'

12. In a muffler construction, a baflle member. for disposition across the muflle chamber of the mufller, said bafiie having a generally axially projectingcircular corrugation-like rib portion having. opposed walls with opposed generally aligned orifices therein through which fluid to be muflied is sub-divided intojets that collide head-onwithin a channel groove chamber provided, by

the rib portion.

13. In amufiier structure including means defining a mufile chamber having an inlet at one end and an outlet 'atthe opposite "end, said chamber having fixedly thereacr'oss and in spaced relation a plurality of baflie walls defining therebetween expansion spaces, each of said walls having a corrugation-like rib projecting generally toward the inlet end and in each instance defining a narrow channel opening toward the outlet end, said ribs being defined by confronting walls, said walls having respec'tive jet-forming series'of orifices therein generally aligned with the jetorifices of the confronting wall in each instance so that fluid to be muflled entering the chamber through the inlet end is forced to pass through lide head-on with the jets from the respective opposed orifices within the respective rib channels before moving out ot said channels into the expansion space into which the channel opens. i

References Cited in the file of this patent V llllhll'lIL-il) STATES PATENTS Italy Apr. 29, 1952

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