US2930440A

US2930440A - Exhaust system

Info

Publication number: US2930440A
Application number: US686940A
Authority: US
Inventors: George L Fetzer; Leonard M Morrish
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1957-09-30
Filing date: 1957-09-30
Publication date: 1960-03-29
Anticipated expiration: 1977-03-29

Description

March 29, 1960 G, 1 FETZER ETAL 2,930,440

EXHAUST SYSTEM INVENTORS. 16J/? 2 Shets-Sheet 1 gg@ Blsazzazef Filed Sept. 30, 1957 A trafen/5y.

March 29, 1960 G. L. FETZER ETAL 2,930,440

EXHAUST SYSTEM 2 Sheets-Sheet 2 Filed Sept. 50, 1957 EXHAUST SYSTEM George L. Fetzer and Leonard M. Morrish, Flint, Mich., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application September 30, 1957, Serial No. 686,940

Claims. (Cl. 181-54) This invention relates to sound attenuating devices for use in the exhaust systems of internal combustion en- Y gines and has particular relation to muliiers, resonators and other sound attenuating devices adaptable for use in different combinations for attenuating sounds in a wide variety of engine installations.

In the manufacture of motor vehicles it is necessary to be able to supply a large variety of engines of different displacements, compression ratios, horse power, etc. These require different exhaust systems, either single or dual exhaust systems and sometimes both for each engine installation. The variety of mul'llers that are required to tune out or mul'lle the objectionable exhaust noises in each of these installations presents a tooling and inventory problem which has become large and objectionable. To solve this problem it is proposed to provide a mufller and a number of resonators which can be employed in different combinations to provide a variety of exhaust systems that can be tuned to attenuate the sounds in a large number of engine installations.

In the drawings:

Figure l is a fragmentary view of a motor vehicle chassis embodying an exhaust system means embracing the principles of the invention;

Figure 2 is a cross-sectional view of a muflier embodied in the exhaust system or systems disclosed by Figure l. Figure 2 is taken in the plane of line 2--2 of Figure 1 looking in the direction of the arrows thereon;

Figure 3 is an enlarged fragmentary perspective view of an acoustical coupling means embraced in the muffler disclosed by Figure 2.

Figure 4 is a longitudinal sectional view through the mufer disclosed by Figures 1 and 2 and takenV substantially in the plane of line 4-4 on Figure 2 and looking in the direction of the arrows thereon.

Figure 5 is an enlarged fragmentary cross sectionalfview of one of the resonators embodiedv in the structure disclosed by Figure l. Figure 5 is taken substantially in the plane of line S-Son Figure 1 and looking in the direction of the arrows thereon.

Figure 6 is a longitudinal sectional view of the resonator disclosed by Figure 5.

The frame 10 disclosed by Figure l1 supports an ex haust system 11 which is adapted to exhaust to the atmosphere at the rear of the vehicle the products of combustion from an engine supported at the front of the.

frame and employed in driving the vehicle. Thev exofv a single exhaust conduit means 12or it .mayv be a dual exhaust system consisting of a pair of the exhaust conduit means 12 and 13. Single or duel exhaust systems are employed in motor vehicles having the same engines as well as with motor vehicles having different engines. In such installations,the exhaust conduit means 12 and 13 may embody mutllers 14 and a variety of resonators 16 and 17.

The muliiers 14 may embody casings 18 consisting of haust system 11 may be a single exhaust system consisting 2, terial 22. The casings 18 have ends 23 and 24 secured toY the ends of the walls 19 and 21 by beads or rolled seamsA indicated at 26. The interiors of the casings 18 are di vided by

partitions

27, 28, 29, 31 and 32 extending trans-v versely across the casings and all being spaced between the end walls 23 andV 24 to provide resonating chambers 33,.

34, and 36 and expansion chambers 37 and 38. Resonating chambers 33 are small high frequency resonating; chambers located at the inletends of the casings 18 while, resonating chambers 36 are large low frequency reso-4 nating chamberslocated adjacent the outlet ends of thecasings 18. The resonating chambers 34 also are small', high frequency chambers, these being located between,y the expansion chambers 37 and 38 disposed between theexpansion chambers 33 and 36. Inlet conduits 39 extend through the end walls 23 and the

partitions

27, 28

and 29 and supply exhaust gas to the expansion charn-l bers 38. Return conduits 41 extend through partitions; 28 and 29 and connect the expansion chambers 37 and. 38. Outlet conduits 42 extend through

partitions

28, 29,', 31 and 32 and the end wall 24 to connect the expansion; chambers 37 to the atmosphere at the rear of the vehicle.

Figure 3 illustrates a part of the casing Wall 27 in' which extrusions 44 have been struck outbetween pairs.

Ofslits 46. The extrusions 44 provide openings 47 groups of which provide acoustical coupling means such..

as that formed in partitions 27 and indicated at 48. The acoustical coupling means 48 is formed in partitions 27 between the resonating chambers 33 andexpansion charn-- bers 37 and in directly opposed relation to the inlet ends. of the outlet conduits 42. Other extrusons illustrated.

within dot and dash lines provide acoustical coupling means 49 and 51 in the conduits 39 and 41 respectively and acoustically coupling the conduits 39 and 41 throughthe resonating chambers 34. Another group of the extru sions 44 illustrated within dot and dash lines provide acoustical coupling means 52 in the outlet conduits 42. The acoustical coupling means 52 connect the conduits 42 to the resonating chambers 36 through annular acoustical coupling means 53 surrounding the conduit 42and within tubes 54 secured to the conduits 42 at 56 andA opening at the opposite ends into the resonatingcham bers 36. The resonating chambers 36 extend from parti-'- tions 31 to thewalls 24, the partitions 32 being provided with extensive openings indicated at 57 for coupling the. ends of the chambers 36 without appreciable restriction.4

The close coupling of the high frequency resonating chamber means 33 and 34 with the low frequency resonating chamber means 36 through the expansion chamber means 37 and 38 and the acoustical coupling means 48,

49, 51, 52 and 53 prevents the mufflers 14 from beingv sharply tuned to the vibrational frequencies of the resonating chamber means 33, 34 and 36. Instead of such sharp tuning the coupling means reduces the amplitude of sound attenuation of the frequencies represented by the resonating chamber means 33, 34 and 36 and spreads the tuning throughout a range of frequencies extending from the high frequencies of the resonating chamberV means 33 andV 34 to the low frequency of the resonatingchamber means 36. It is therefore possible to employ the mufers 14 for tuning sounds throughout a sound frequency range extending from the high frequencyrepr'esented by the resonating chambers 33, 34 to the low fre-v low and the frequency range is wide. It is also possible to use such mufllers in a dual exhaust system in which Patented Mar. 29, 1960- throughout the same frequency range but arer of greater` amplitude in one conduit than in the other.

Under such circumstances a resonator such as that indicated at 16 may beemployed. The resonator 16 also may be formed by employing a casing 61 having spaced walls 62 and'63 separated by sound absorbing material indicated at 64. The ends of the casing are closedvby end walls 66 and 67 fastened to the side walls 62 andv63 by rolled 'seams 68. The interior of the casing 61 is divided by partitions 69 and 71 into resonating chambers 72, 73 and 74. Outlet conduit 42 extends through the resonator 16 and is acoustically coupled to the resonating chambers 72, 73 and 74 by acoustical coupling means 76, Y77 and 78 formed by the 'extrusions'44. rThe' tuning frequency of the resonating chambers 72,73, 74'within the resonator 61 may be within the'freq'uen'cy range which includes and extends between the frequency of the high frequency resonating chambers 33 and 34 and the low frequency resonating chamber 36 in the mufl'lers 14. Y

The muilers 14 also may be used in the same exhaust system for engines where the low frequency sounds are of greater amplitude. To do this it is necessary only to attach single low frequency resonators 17 in the outlet conduits 42. Y t

Such added frequency resonators will give the exhaust system a iiexibility and range of application which will permit the utilization of a relatively small number of sound attenuating units in a wide variety of combinations in either single or dual exhaust systems for a largenumbcr of engines.

We claim:

1. An exhaust system for internal combustion engines for motor vehicles and the like and comprising an elongated casing having transverse' partitions disposed therein and dividing said casing into a plurality of acoustical Vexpansion and resonating chamber means, there being a pair of said expansion chamber means separated by high frequency. resonating chamber means at the inlet end of said casing and low frequency resonating chamber means beyondY said expansion chamber means and said high frequency resonating chamber means and at the outlet Vend of said casing,.an inlet conduit extending through one end of said casing and through one of said expansion chamber means and ksaid high frequency resonating chamber means and opening at the inner end thereof into the other of said expansion chamber means, a return conduit extending through said high frequency resonating chamber means and opening atzthe opposite ends thereof into said pair of expansion chambermeans, an outlet pansion and resonating chamber means, there being a pair of said expansion chamber means separated by high frequency resonating chamber means at the inlet end of said casing and low frequency resonating chamber means beyond said expansion chamber means and said high frequency resonating chamber means and at the outlet end of said casing, an inlet conduit extending through one end of said casing and through one of said expansion chamber means and saidhigh Yfrequency resonating chamber means and opening at the inner end thereof into the other of said expansion chamber means, a return conduit extendingthrough said high frequency resonating chamber means and opening at the opposite ends thereof into said pair of expansion chamber means, an outlet conduit having the inlet end thereof opening into said one of said expansion chamber means and extending through said high frequency resonating chamber means and said other of said expansionchamber means and through said low frequency resonating chamber means and outwardly of said casing through the opposite end of said casing, means acoustically coupling said inlet conduit and said return conduit to said high frequency resonating chamber means, and means acousticallyrcoupling said low frequency resonating chamber means to said outlet conduit, said expansion chamber meansv and said high frequency resonating chamber means and said low frequency resonating chamber means and said acoustical coupling means being capable of being tuned to attenuateiso'unds throughout a relatively wide frequency range and including within isaid range sounds of the same frequency as the frequency ofY said high frequency resonating chamber means and of the same frequency as the frequency of said low frequency resonating chamber means.

3. An exhaust system forginternal combustion-engines for motor vehicles and the like and comprising, an elongated casing having transverse partitions disposed therein and dividing said casing into a plurality of acoustical expansion and resonating chamber means, there being a pair of said expansion chamber means separated byfhigh frequency resonating chamber means Vat the inlet end of said casing and low frequency resonating chamber means beyond said expansionV chamber means and said high fre- Y quency resonating chamber means and at the outlet end conduit having the inlet end thereof opening into said t one of said expansion chamber means and extending through said high frequency resonating chamber means and said other of said expansion chamber means and through said low frequency resonating chamber means and outwardly of said casing through the opposite end of said casing, means acoustically coupling a pair of said conduits to one Vanother' through said high frequency resonating chamber means, and means acoustically coupling said low frequency resonating chamber means to said outlet conduit, said expansion chamber means and said high frequency resonating chamber means and said low frequency resonating chamber means and said acoustical coupling means being capable of being tuned to attenuate sounds throughout a relatively wide frequency range and including Within saidY range sounds of the same frequency as the frequency of said high frequency resonating chamber means and ofthe same frequency as the frequency of said low Vfrequency resonating chamber means.

2. An exhaust system for internal combustion engines for motor vehicles and the like and comprising an elongated casing having transverse partitions disposed therein' and dividing said casing into aplurality of acousticalexof said casing, an inlet conduit extending through one end of said casing and through one of said expansion chamber means and said high frequency resonating chamber means and opening at the inner end thereof into the other of said expansion chamber means, aV return conduit extending through said high frequency resonating chamber means and opening at the opposite ends thereof into said pair Vof expansion chamber means, an outlet conduit having the inlet end thereof opening into said one of said expansion chamber means and extending through said high frequency resonating chamber means and said other of said expansion chamber means and through said low frequency resonating chamber means and outwardly of said casing through the opposite end of said casing, additional high frequency resonating chamber means formed in said y casing'anterior to said one of said expansion chamber means Yand throug'hrwhich said' inlet conduit extends, means acoustically coupling said inlet conduit and said return conduit to said'high frequency resonating chamber means, means directlyaligned with Vthe inlet end ofrsaid outlet'conduit Vandacoustically coupling said additional high frequency resonating chamber means to said outlet conduit and saidone of said expansion chamber means7 and means acoustically coupling said low frequency resonating chamber means to saidoutlet conduit, said expansion chamber means and said high frequency resonating chamber means and said low frequency resonating chamber means and said acoustical coupling means being capable of being tuned to attenuatesounds throughout a relatively wide frequency range and including within said range sounds of the'same frequency as the frequency' of said high frequency resonating chamber means and of the same frequency as the frequency of said low frequency resonating chamber means.

4. An exhaust system for internal combustion engines for motor vehicles and the like and comprising an elongated casing having transverse partitions disposed therein and dividing said casing into a plurality of acoustical expansion and resonating chamber means, there being a pair of said expansion chamber means separated by high frequency resonating chamber means at the inlet end of said casing and low frequency resonating chamber means beyond said expansion chamber means and said high frequency resonating chamber means at the outlet end of said casing, an inlet conduit extending through one end of said casing and through one of said expansion chamber means and said high frequency resonating chamber means and opening at the inner end thereof into the other of said expansion chamber means, a return conduit extending through said high frequency resonating chamber means and opening at the opposite ends thereof into said pair of expansion chamber means, an outlet conduit having the inlet end thereof opening into said one of said expansion chamber means and extending through said high frequency resonating chamber means and said other of said expansion chamber means and through said low frequency resonating chamber means and outwardly of said casing through the opposite end of said casing, means acoustically coupling said inlet conduit and said return co'nduit to said high frequency resonating chamber means, means acoustically coupling said low frequency resonating chamber means to said outlet conduit, said expansion chamber means and said high frequency resonating chamber means and said low frequency resonating chamber means and said acoustical coupling means being capable of being tuned to attenuate sounds throughout a relatively wide frequency range and including Within said range sounds of the same frequency as the frequency of `said high frequency resonating chamber means and of the same frequency as the frequency of said low frequency resonating chamber means, and additional resonating chamber means within said frequency range and -acoustically coupled to said outlet conduit externally of said casing and capable of being tuned to attenuate sounds throughout said range and increasing the sound attenuating capacity o'f said system in said range.

5. An exhaust system for internal combustion engines for motor vehicles and the like and comprising, a pair of elongated casings having transverse partitions disposed therein and dividing said casings into a plurality of acoustical expansion and resonating chamber means, there being a pair of said expansion chamber means separated by high frequency resonating chamber means at the inlet ends of said casings and low frequency resonating chamber means beyond said expansion chamber means and said high frequency resonating chamber means at the outlet ends of said casings, an inlet conduit extending through one end of each of said casings and through one of said expansion chamber means and said high frequency resonating chamber means and opening at the inner end thereof into the other of said expansion chamber means, a return conduit in each of said casings and extending through said high frequency resonating chamber means and opening at the opposite ends thereof into said pair of expansion chamber means, an outlet co'nduit in each of said casings and having the inlet end thereof opening into said one of said expansion chamber means and extending through said high frequency resonating chamber means and said other of said expansion chamber means and through said low frequency resonating chamber means and outwardly of said casings through the opposite ends of said casings, means acoustically coupling a pair of said conduits in each of said casings to one another through said high frequency resonating chamber means, means acoustically coupling said low frequency resonating chamber means to said outlet conduits in each of said casings, said expansion chamber means and said high frequency resonating chamber means and said low frequency resonating chamber means and said acoustical coupled means in each of said casings being capable of being tuned to attenuate sounds throughout a relatively wide frequency range and including within said range sounds of the same frequency as the frequency of said high frequency resonating chamber means and of the same frequency as the frequency of said low frequency resonating chamber means, and additional resonating chamber means within said frequency range and acoustically coupled to one of said outlet conduits externally of said casing of said outlet conduit and capable o'f being tuned to attenuate sounds throughout said range and increasing the sound attenuating capacity of one part of said system in said range, said part of said system being the part of said system having said additional resonating chamber means.

References Cited in the file of this patent UNITED STATES PATENTS 2,020,054 Ford Nov. 5, 1935 2,188,202 Mackenzie Jan. 23, 1940 2,618,354 Hedrick No'v. 18, 1952 2,652,128 Cary Sept. 15, 1953 OTHER REFERENCES Motor," March 1932, page 48.