US3340958A

US3340958A - Muffler for internal-combustion engine

Info

Publication number: US3340958A
Application number: US536322A
Authority: US
Inventors: Patrick J Conlin
Original assignee: CONE MUFFLER DEV CO Ltd
Current assignee: MACAULAY NEIL P; CONE MUFFLER DEV CO Ltd
Priority date: 1966-03-22
Filing date: 1966-03-22
Publication date: 1967-09-12
Anticipated expiration: 1984-09-12
Also published as: BE703719A; NL6712125A; GB1126511A; NL129150C

Description

P. J. CON LIN Sept. 12, 1967 MUFFLER FOR INTERNAL-COMBUSTION ENGINE 2 Sheets-Sheet 1 Filed March 22, 1966 INVENTOR. PATRICK J. CONLIN Sept. 12, 1967 P. J. CONLIN R FOR INTERNAIrCOMBUSTION ENGINE MUFFLE 2 Sheets-Sheet 1' Filed March 22, 1966 INVENTOR. PATRICK J. CONLIN ATTORNEY United States Patent Ofiice 33405958 Patented Sept. 12, 1967 3,340,958 MUFFLER FOR INTERNAL-COMBUSTION ENGINE Patrick J. Conlin, Vancouver, British Columbia, Canada,

assignor to Cone Muffler Development Co., Ltd., Vancouver, British Columbia, Canada, a corporation of Canada Filed Mar. 22, 1966, Ser. No. 536,322 Claims. (Cl. 181-58) ABSTRACT OF THE DISCLOSURE A muffler for internal-combustion engines comprising a cylindrical hollow body having diametrically opposite, identically tangentially disposed inlet and outlet nipples extending into said body at opposite sides of a dividing wall having a tube extending therethrough whereby the input gases. are caused to partake of a whirling motion at an asynchronously increasing rate, then to pass through the tube to the opposite side of the partition and thereafter to asynchronously decrease in the rate of rotation or whirl in the same direction en route to the outlet port.

This invention relates to mufiler devices for the exhaust of internal-combustion engines and more particularly to a muffler device embodying improvements over that disclosed in my prior Patent No. 3,166,152 granted Jan. 19, 1965.

The principal object of the invention is to provide a mufller in which the pulsations of the exhaust gases as received from the engine are first asynchronously imposed on each other at an increasing frequency rate and thereafter, also asynchronously, imposed on each other at a decreasing frequency rate whereby the pulsations tend almost wholly to cancel themselves out with resultant substantially complete elimination of the vibrations causing the noise of an engine exhaust.

Other objects of the invention are to provide a muiller of the foregoing character which is composed of few parts, all of which are united into a unitary structure, which is much smaller in size for a given volume of exhaust gases than mufflers presently in common use, which imposes a minimum of back pressure on the exhaust gases, and which is economical to manufacture.

With the foregoing objects in view, together with such additional objects and advantages as may subsequently appear, the invention resides in the parts and in the construction, combination and arrangement of parts described, by way of example, in the following specification of a presently preferred embodiment of the invention, reference being had to the accompanying drawings which form a part of said specification and in which drawings:

FIG. 1 is a reduced scale, perspective view of a muflier constituting a presently preferred embodiment of the invention,

FIG. 2 is a geratly enlarged, exploded view of the muffler as shown in FIG. 1, taken as though the mufiler had been cut apart on a plane coincident with the center lines of the inlet and outlet port nipple components,

FIG. 3 is a medial sectional view on a slightly smaller scale than FIG. 2 taken in the plane including the line 33 of FIG. 1 and extending transversely of the center lines of the two port nipple components,

FIG. 4 is a sectional view in the same scale as FIG. 3 taken on the staggered line 44 of FIG. 1, and

FIG. 5 is a perspective view of a centrally disposed tubular component of the device.

Referring to the drawings, the muffler body structure 1 comprises a cylindrical center body portion 2 formed by a circular, thin metal wall 3 having an oval opening 4 extending therethrough through which an inlet nipple 5 extends tangentially with respect to the wall 3 from a point exteriorly of said wall and of sufficient length to permit connection to an exhaust conduit leading from an engine, said nipple extending through the wall 3 to a point within the muffler body which is slightly short of a center medial plane of said body member extending in a direction normal to the center line of the nipple component The wall 3 at a point diametrically opposite the opening 4 is provided with a similar opening 6 through which an outlet nipple component 7 extends similarly tangentially to the nipple 5 and in the same direction circularly of the body wall 3 as the nipple 5, said nipple extending from a point within the body which is slightly short of the plane referred to with respect to the inner end of the nipple 5 through the wall 3 and terminating exteriorly of the wall in a length sufiicient to permit connection of a tail pipe or the like if desired. The

nipples

5 and 7 are rigidly connected to the wall 3 by welding or brazing and preferably disposed with the axial lines thereof parallel to each other and at least substantially adjacent to a plane which is normal to the axial line of said body at the midlength of said cylindrical portion thereof.

The enclosure of the muffler body is completed by opposed outwardly pointed conical

end wall members

8 and 9 having edge portions which overlap the edges of the body member 3 and said end wall members are brazed or welded to the body member 3 to effect a unitary structure of the body and the end members. All of the above described body forming components are formed of suitable sheet metal stampings and lengths of tubing and, as noted, are of simple design, wherefore the cost of manufacture is kept at a minimum.

The interior of the body structure is divided into two compartments of substantially identical configuration by a center wall member 10 comprising a disk of metal of slightly oval configuration which is placed within the body member 3 so that with respect to the internal end of the inlet nipple 5 it is at the side thereof adjacent the end member 8 and with respect to the inner end of the outlet nipple 7 it is at the side of said nipple which is adjacent the end member 9, it being noted particularly in FIGS. 3 and 4 that the inner ends of the

nipples

5 and 7 are slightly flattened as at 5 and 7', respectively, to enable the circumferential edge of the end wall member 10 to be retained within the confines of the body wall member 3. This partition wall 10 is secured at various points along its circumference to the interior surface of the body member 3 by appropriate spot welds. For identification, the compartment formed by the wall 10, a portion of the body member 3 and the end member 8 and which is in communication with the inner end of the inlet nipple 5 will be designated as the inlet compartment 11 and the corresponding compartment which is in communication with the outlet nipple 7 will be designated as an outlet compartment 12.

Communication between the

compartments

11 and 12 is afforded by a tube 13 of substantially the same diameter as the outlet and inlet nipples and which is disposed axially of the mufiler body and which extends through an opening 13 in the wall 10 and being welded in place therein. The end 14 of the tube which is disposed in the inlet compartment 11 is cut away at opposite sides as at 15, 15 to form a pair of diametriaclly

opposite leg portions

16, 16 which are welded to the inner face of the end member 8. Adjacent the edge surfaces of the end 14, the wall thereof is provided with a plurality of the end member 9 as best shown in FIGS. 3 and 4 and adjacent to said end the tube is provided with a plurality of small holes 19 extending therethrough which are generally similar to the holes 17 at the opposite end of the tube.

It is again to be noted that the entire mufiler assembly is composed of what is essentially only four different parts, since the two end members and the nipple components are identical, and that all of the parts are individually of simple design and capable of economical manufacture. Still further, it is to be noted that all of the parts are welded together to form a construction which for all purposes may be regarded as being integral.

In operation, the exhaust gas entering the compartment 11 through the inlet nipple 5 must exit through the tube 13 to the outlet compartment 12 and thence through the outlet nipple 7 to atmosphere. Since the gas enters the v mufiier body tangentially of the wall of the body portion 3 the initial motion of the gas within the compartment 11 is circular therein and since the entrant end of the tube 13 is at the reduced diameter portion of the conical end wall, the rate of rotation of the gas as it approaches this smaller diameter end gradually asynchronously increases. Since the gas coming from the engine is delivered is a pulsating condition deriving from the operation of the engine, these pulsations within the inlet compartment 12 impose themselves on each other and tend to cancel each other out. Moreover, since the gas enters the tube 13 from opposite sides thereof the pulsations also tend further to oppose each other and to cancel each other out as they enter this tube. The progress of the gas going through the tube 13 is accompanied by an intense whirling motion therein deriving from the nature of the entrance of the gas into the inlet chamber 11 and emerging from the end 18 of the tube 13; the gas and its whirling motion must be slowed down by reason of gradually reaching the diameter of the body portion 3 in which the inner end of the outlet nipple is located. This is also an asynchronous change of rate of the whirling motion of the gas and for all practical purposes, completes the elimination of the pulsation of the gas resulting in a uniformly steady and noiseless emission of the gas from the muffler.

Referring now to the

holes

14 and 19, the exact manner in which these holes operate on the whirling gas is admittedly not known. Repeated experiments have shown, however, that adding these holes has measurably contributed to the silencing effect of this muffler. Several theories have been advanced and the most probable one seems to be that the holes 14, by permitting a portion of the gas to enter the tube radially in addition to the axial flow therethrough, tend to oppose and reduce the velocity of rotation of the gas as it traverses the tube 13 and that similarly, the holes 19 permit a portion of the gas traversing the tube 13 to escape radially through said holes into the outlet compartment 12 and correspondingly assist in further reducing this whirling movement of the gas in that chamber or compartment. Additionally, it is probable that holes 14 and 19 (particularly the holes 14) serve to destroy and tendency to form a vacuum pocket in the gas flow as it changes its direction of movement flowing around the thin edge of the tube 13 as it enters the tube at high velocity. As in my said prior patent, there are no baffles or other obstructions to the flow of exhaust gas, wherefore, the possibility of deleterious back pressure is practically eliminated.

While in the foregoing specification there is disclosed a presently preferred embodiment of the invention, the invention is not to be deemed to be limited to the precise details of construction thus disclosed by way of example and it will be understood that the invention includes as Well, all such changes and modifications in the parts and in the construction, combination and arrangement of parts as shall come within the purview of the appended claims.

I claim:

1. In a muffler for internal-combustion engines, a hollow body comprising a generally cylindrical center portion having opposed, outwardly pointed conical ends, a partition within said body dividing said body into two compartments comprising an inlet compartment disposed at one side of said partition, a portion of the cylindrical body and one of said ends, and an outlet compartment disposed at the other side of said partition, the remainder of said cylindrical body and the other of said ends, an inlet nipple extending through said cylindrical center portion of said body and disposed generally tangentially with respect to the outer diameter of said cylindrical center portion of said body at a point between the ends of said center portion and communicating with the interior of said inlet compartment at a point therein adjacent to a plane containing the axial line of said body and disposed normal to the axial line of said inlet nipple, an outlet nipple extending through said cylindrical portion in the same tangential direction as said inlet nipple at a point spaced from said inlet circumferentially of said body and affording communication between said outlet compartment and atmosphere with said outlet compartment, and a conduit means open at both ends thereof extending through said partition in the axial line of said body affording communication between said compartments.

2. A muffler for internal-combustion engines as claimed in claim 1 in which said inlet and outlet nipples are disposed with the axial line thereof disposed substantially in a plane normal to the axial line of said body and substantially at the mid-length of said cylindrical portion of said body, and in which said partition constitutes a fiat plate closely fitting the interior wall of the cylindrical portion of said body and extends from one side of said inlet nipple to the opposite side of said outlet nipple.

3. A mufiier for internal-combustion engines as claimed in claim 1 in which said conduit means through said partition comprises a tube having a first open end constituting an inlet orifice means disposed adjacent the apex of the conical end wall of the inlet compartment and a second open end constituting an outlet orifice disposed adjacent the apex of the conical end wall of the outlet compartment.

4. A mufiler for internal-combustion engines as claimed in claim 3 in which said tube includes pluralities of holes extending through the wall thereof adjacent the open ends thereof.

5. A muffler for internal-combustion engines as claimed in claim 3 in which said tube has one end thereof fixedly mounted on the conical end wall of said inlet compartment and the midlength portion thereof fixedly mounted in said partition, and in which the end of said tube within said outlet compartment is spaced from the conical end wall of said outlet compartment.

References Cited UNITED STATES PATENTS U 447,333 3/1891 Kutsche.

2,455,965 12/1948 Wohlberg 181-67 X 3,166,152 1/1965 Conlin 181-58 FOREIGN PATENTS 1,179,716 12/1958 France.

330,104 12/ 1920 Germany.

RICHARD B. WILKINSON, Primary Examiner, ROBERT S. WARD, J Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,340,958 September 12, 1967 Patrlck J. Conl1n It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 66, for "dlametrlaclly" read dlametrlcally column 3, line 59, for "and" read a any t Signed and sealed this 24th day of September 1968 (SEAL) Attest:

Edward M. Fletcher, Jr. EDWARD J. BRENNER Attesting Officer Commissioner of Patents

Claims

1. IN A MUFFLER FOR INTERNAL-COMBUSTION ENGINES, A HOLLOW BODY COMPRISING A GENERALLY CYLINDRICAL CENTER PORTION HAVING OPPOSED, OUTWARDLY POINTED CONICAL ENDS, A PARTITION WITHIN SAID BODY DIVIDING SAID BODY INTO TWO COMPARTMENTS COMPRISING AN INLET COMPARTMENT DISPOSED AT ONE SIDE OF SAID PARTITION, A PORTION OF THE CYLINDRICAL BODY AND ONE OF SAID ENDS, AND AN OUTLET COMPARTMENT DISPOSED AT THE OTHER SIDE OF SAID PARTITION, THE REMAINDER OF SAID CYLINDRICAL BODY AND THE OTHER OF SAID ENDS, AN INLET NIPPLE EXTENDING THROUGH SAID CYLINDRICAL CENTER PORTION OF SAID BODY AND DISPOSED GENERALLY TANGENTIALLY WITH RESPECT TO THE OUTER DIAMETER OF SAID CYLINDRICAL CENTER PORTION OF SAID BODY AT A POINT BETWEEN THE ENDS OF SAID CENTER PORTION AND COMMUNICATING WITH THE INTERIOR OF