CA2059434C - Exhaust system for snowmobile - Google Patents
Exhaust system for snowmobile Download PDFInfo
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- CA2059434C CA2059434C CA 2059434 CA2059434A CA2059434C CA 2059434 C CA2059434 C CA 2059434C CA 2059434 CA2059434 CA 2059434 CA 2059434 A CA2059434 A CA 2059434A CA 2059434 C CA2059434 C CA 2059434C
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Abstract
An exhaust system for the internal combustion engine of a snowmobile that permits joining of the exhaust ports of pairs of cylinders and the use of a single silencer without having the exhaust pulses from one cylinder adversely effect those of another cylinder of the joining pairs. This is done by having adjacent cylinders fire at 180 degrees from each other so that their exhaust gases can be combined in a single manifold without adverse effects. The individual exhaust manifolds of the paired cylinders then communicate with a common silencing device through separate inlets.
Description
2503~F2024 EXHAUST SYSTEM FOR SNOWMOBILE
BACKGROUND OF THE INVENTION
This invention relates to an exhaust system for a multiple cylinder internal combustion engine and more particularly to an improved exhaust system for a snowmobile.
As is well known, snowmobiles are extremely compact devices.
This means that the powering internal combustion must be very compact in nature and be able to fit into a relatively small and confined space. However, there is a trend toward using multiple cylinder engines for driving snowmobiles. When multiple cylinder engines are employed, this gives rise to several difficulties in providing a compact engine construction.
For example, the exhaust gases from the engine should be passed through an exhaust system that includes one or more silencing devices to insure against undue exhaust noise.
However, if an attempt is made to collect the exhaust gases from multiple cylinders in a common exhaust system, the exhaust pulses from one cylinder can travel back through the common exhaust system to another cylinder and seriously diminish the performance of the engine.
It is, therefore, a principal object of this invention to provide an improved exhaust system for a multiple cylinder internal combustion engine.
It is a further object of this invention to provide an exhaust system for a multiple cylinder internal combustion engine wherein the exhaust gases from plural cylinders may be combined in a single manifold and the manifolds may all communicate with a single silencing device without causing adverse reactions between the individual cylinders thus joined.
SUMMARY OF THE INVENTION
This invention is adapted to be embodied in an exhaust system for an internal combustion engine having a plurality of pairs of exhaust ports. A plurality of exhaust manifolds each have a pair of inlet openings each of which communicates with a respective one of the pair of exhaust ports and which exhaust ports do not open at the same time to receive exhaust gases and a common outlet. A silencer has a plurality of inlets each receiving exhaust gases from the common outlet of a respective one of the exhaust manifolds and an atmospheric exhaust.
BRIER DESCRIPTION OF THE DRAWINGS
Figure 1 is a side elevational view of a snowmobile constructed in accordance with an embodiment of the invention.
Figure 2 is a top plan view of the snowmobile.
Figure 3 is an enlarged view taken in the same direction as Figure 1 showing the engine and exhaust system in solid lines in the snowmobile body and associated components in phantom.
Figure 4 is an enlarged top plan view, in part similar to Figure 2, showing the engine and exhaust system in solid lines and the snowmobile in phantom.
BACKGROUND OF THE INVENTION
This invention relates to an exhaust system for a multiple cylinder internal combustion engine and more particularly to an improved exhaust system for a snowmobile.
As is well known, snowmobiles are extremely compact devices.
This means that the powering internal combustion must be very compact in nature and be able to fit into a relatively small and confined space. However, there is a trend toward using multiple cylinder engines for driving snowmobiles. When multiple cylinder engines are employed, this gives rise to several difficulties in providing a compact engine construction.
For example, the exhaust gases from the engine should be passed through an exhaust system that includes one or more silencing devices to insure against undue exhaust noise.
However, if an attempt is made to collect the exhaust gases from multiple cylinders in a common exhaust system, the exhaust pulses from one cylinder can travel back through the common exhaust system to another cylinder and seriously diminish the performance of the engine.
It is, therefore, a principal object of this invention to provide an improved exhaust system for a multiple cylinder internal combustion engine.
It is a further object of this invention to provide an exhaust system for a multiple cylinder internal combustion engine wherein the exhaust gases from plural cylinders may be combined in a single manifold and the manifolds may all communicate with a single silencing device without causing adverse reactions between the individual cylinders thus joined.
SUMMARY OF THE INVENTION
This invention is adapted to be embodied in an exhaust system for an internal combustion engine having a plurality of pairs of exhaust ports. A plurality of exhaust manifolds each have a pair of inlet openings each of which communicates with a respective one of the pair of exhaust ports and which exhaust ports do not open at the same time to receive exhaust gases and a common outlet. A silencer has a plurality of inlets each receiving exhaust gases from the common outlet of a respective one of the exhaust manifolds and an atmospheric exhaust.
BRIER DESCRIPTION OF THE DRAWINGS
Figure 1 is a side elevational view of a snowmobile constructed in accordance with an embodiment of the invention.
Figure 2 is a top plan view of the snowmobile.
Figure 3 is an enlarged view taken in the same direction as Figure 1 showing the engine and exhaust system in solid lines in the snowmobile body and associated components in phantom.
Figure 4 is an enlarged top plan view, in part similar to Figure 2, showing the engine and exhaust system in solid lines and the snowmobile in phantom.
~~'~ ~~9'~~~
Figure 5 is a further enlarged side elevational view, taken in the same direction as Figure 3, and shows only the exhaust manifolds and their association with the exhaust silencing device.
DETAILED DESCRIPTION OIa THE PREFERRED EMBODIMENT OF THE INVENTION
Referring first to Figures 1 and 2, a snowmobile constructed in accordance with an embodiment of the invention is identified generally by the reference numeral 11. The snowmobile 11 includes a body assembly 12 made up of a number of parts which may be formed from suitable materials and which includes a nose piece 13 an upper engine cowling 14 and a lower tray 15 which together define an engine compartment in which a powering internal combustion engine, indicated generally by the reference numeral 16 is positioned.
In the illustrated embodiment, the engine 16 is of the inline four cylinder type operating on a two cycle crankcase compression principal. Although the engine 16 is described as being a four cylinder inline engine, it will be apparent as the description proceeds that the engine 16 is, in fact, comprised of two, two cylinder inline engines joined end to end. Although the invention has particular utility in conjunction with such engines, it is to be understood that certain facets of the invention may be employed with engines of other types. However, the invention does have particular utility in conjunction with two cycle crankcase compression engines, for a reason which will become apparent.
Figure 5 is a further enlarged side elevational view, taken in the same direction as Figure 3, and shows only the exhaust manifolds and their association with the exhaust silencing device.
DETAILED DESCRIPTION OIa THE PREFERRED EMBODIMENT OF THE INVENTION
Referring first to Figures 1 and 2, a snowmobile constructed in accordance with an embodiment of the invention is identified generally by the reference numeral 11. The snowmobile 11 includes a body assembly 12 made up of a number of parts which may be formed from suitable materials and which includes a nose piece 13 an upper engine cowling 14 and a lower tray 15 which together define an engine compartment in which a powering internal combustion engine, indicated generally by the reference numeral 16 is positioned.
In the illustrated embodiment, the engine 16 is of the inline four cylinder type operating on a two cycle crankcase compression principal. Although the engine 16 is described as being a four cylinder inline engine, it will be apparent as the description proceeds that the engine 16 is, in fact, comprised of two, two cylinder inline engines joined end to end. Although the invention has particular utility in conjunction with such engines, it is to be understood that certain facets of the invention may be employed with engines of other types. However, the invention does have particular utility in conjunction with two cycle crankcase compression engines, for a reason which will become apparent.
The body 12 further includes a rear body portion 17 that accommodates a seat 18 adapted to seat one or more riders seated in straddle fashion. A handlebar assembly 19 is positioned forwardly of the seat 18 for steering of the snowmobile, in a manner which will be described.
There is provided further an upper cowling portion 21 which may be removable to access the engine compartment and which carries an upper windshield 22 that is disposed forwardly of the handlebar assembly 19 for affording protection to the riders seated on the seat 18.
A pair of front skis 23 are supported at the forward portion of the body 12 by means of suspension struts 24 which also accommodate steering movement of the skis 23. The struts 24 are interconnected by means of a tie rod 25 so that they may be steered in unison and one of the skis 24 is provided with a steering link 26 which is connected to a steering rod 27 which is, in turn, operated by a steering column 28 that is coupled to the aforementioned handlebar assembly 19.
Rearwardly of the front skis 25, and beneath the seat 18, the body 12 suspends a carriage assembly, indicated generally by the reference numeral 29 by a suitable suspension system and which carriage assembly 29 supports a drive belt, indicated at 31. The drive belt 31 is trained around a driving sprocket 32, which is driven in a manner to be described, and idler sprockets 33 and 34 that are mounted on a pair of rails 35 of the carriage 29. In addition, further idler rolls 36 and 37 are carried by the carriage 29 and engage the drive belt 31 so as to confine and direct its path of movement. The rear idler wheels 37 are carried by frame members 38 of the carriage assembly 26 in a suitable manner.
The engine 16 is disposed transversely in the engine compartment and its output shaft drives a belt driveshaft 39 which extends transversely to the longitudinal center line of the snowmobile 12 as does the -crankshaft or output shaft of the engine l6. This belt driveshaft 39 drives a variable pulley 41 of a variable speed pulley drive mechanism indicatedgenerally by the reference numeral 42. This drive pulley 41 drives a belt 43 which, in turn, drives a driven variable pulley 44 which is affixed to an intermediate shaft 45. The intermediate shaft 45 has affixed to it a sprocket 46 which drives a drive belt 47 which is, in turn, trained around a sprocket that is affixed to a shaft 48 which is also coupled to the belt drive sprocket 32.
The details of the final drive and the engine and its output shaft are set forth more fully in the co-pending Canadian application entitled Power Transmission System For Snowmobile, Serial Number 2,059,395.
Referring now to the remaining figures and initially to Figures 4 and 5 and as has been noted, the engine 16 is of the four cylinder inline type but actually is made up of two, two inline cylinder engines connected end to end. To this end, each of these two cylinder engines comprises a respective cylinder _ 5 _ ~~t~~'~'~ ~!~
block 49 and 51. The cylinder blocks 49 and 51 are, however, connected to a common crankcase assembly 52 which is affixed to the cylinder blocks 49 and 51 in any suitable manner.
The cylinder blocks 49 and 51 slidably support pairs of pistons with the pistons of the cylinder block 49 being disposed so that they fire at 180 degree impulses from each other. In a like manner, the pistons of the cylinder block 51 also fire 180 degrees from each other. The pistons of the cylinder block 49, however, fire at a 90 degree interval from the pistons of the cylinder block 51 so that no two cylinders are firing at the same time, for a reason which will become apparent. The individual cylinders associated with each other cylinder block are designated in Figure 4 by the reference numerals 49a and 49b while those associated with the cylinder block 51 are designated as 51c and 51d. The angular relationship of their firing order is also shown in this figure. The reason for the firing cycle will be described later.
The exhaust ports of the respective cylinder blocks 49 and 51 extend forwardly and terminate in pairs of exhaust ports which communicate with respective paired exhaust manifolds 58 and 59, respectively. The manifolds 58 and 59 have respective pairs of inlet passages 61 and 62 and 63 and 64, respectively, which merge together and terminate in a respective common outlet section 65 and 66. Because the adjacent cylinders of each cylinder block 49 and 51 fire at 180 degrees from each other, it is possible to pair the cylinders through the common inlet passages 61 and 62 and 63 and 64 without any adverse effects on the performance of the engine. That is, no two exhaust ports of the same manifold 58 and 59 will be opened at the same time for any substantial portion of the time that they are open and hence there will be no adverse pulses go back from one exhaust port to the other.
The exhaust manifolds 58 and 59 communicate with respective inlet flanges 67 and 68 of a pair of exhaust pipes 69 and 71.
Spring type fasteners 72 and 73 hold the exhaust pipes 69 and 71 to the exhaust manifolds 58 and 59 while permitting some flexure there between without adversely effecting the seal.
The exhaust manifold 69 and 71 extend forwardly within the engine compartment of the snowmobile 11 and then turn toward one side of the engine, the right hand side in the illustrated embodiment. The intermediate portion of the exhaust pipe 69 and 71 are supported by a pair of frame members 74 and 75 of the body assembly by spring type retainers 76 and 77, respectively.
The exhaust pipes 69 and 71 turn rearwardly and have respective outlet ends 78 and 79 that communicate with respective inlet flanges 80 and 81 of an exhaust silencer device, indicated generally by the reference numeral 82. The exhaust silencer device 82 may have any known type of internal silencing mechanism, depending upon the type of silencing desired and the construction of the particular engine. Coil spring fasteners 83 and 84 respectively couple the exhaust type outlet ends 77 and 78 to the silencer inlet flanges 79 and 81.
The silence 82 is mounted at one end of the engine or at a side of the snowmobile depending upon the frame of reference upon a bracket assembly 90 by means of a spring type fastener 85. A
cushioning construction 86 is interposed between the frame bracket 90 and the silencer 82.
_ 7 _ Because the exhaust pipes 69 and 71 have separate communication with the silencer 82, the pulses which enter the silencer 82 will not flow back-to exhaust ports other than that firing and this reaction is further obtained by the uneven firing impulses between the cylinders, as aforenoted. The silencing device 82 has a downwardly curved discharge end 87 which discharges the exhaust gases to the atmosphere after they have been silenced by the silencing device 82.
The snowmobile engine is water cooled and has a water cooling system of the type as described in co-pending Canadian application entitled Engine Cooling System For Snowmobile, Serial Number 2,059,416. This cooling system includes a water pump driven by the engine output shaft and which circulates water through the engine for discharge through a thermostat 102 positioned on the intake side of the engine and through a transversely extending cross flow radiator 103. In cross flow radiator 103 the coolant is discharged to a heat exchanger system, shown in Figures 1 and 2.
This heat exchanger system is of the type described in more detail in the co-pending Canadian application Wind Leading System For Snowmobile, Serial Number 2,059,415. Basically this heat exchanger system includes the cross flow radiator 103 that is disposed generally above the engine and specifically above the exhaust _ g _ Ao ~~~ L,.t, ~I
manifolds 58 and 59. A conduit 104 communicates the thermostat 102 with the left hand side of the cross flow radiator 103.
Coolant is then delivered from the other side of the cross flow radiator 103 to a conduit 105 that extends along the right side of the snowmobile and which then curves inwardly to communicate with a longitudinally extending heat exchanger 106 that extends along one side of the underside of the seat 18. The seat 18 is constructed and configured so that air can flow across the heat exchanger 106 for its cooling but some heat will also be transferred to the seat 18 so as to warm the riders.
At the rear end of the seat 18, the heat exchanger 106 communicates with a conduit 107 that supplies coolant to a further transversely extending heat exchanger 108. The heat exchanger 108 then communicates with a conduit 109 which delivers the coolant to a further longitudinally extending heat exchanger 111 which extends parallel to the heat exchanger 106 on the other side of the seat 18. The heat exchanger 111 communicates at its forward end with a conduit 112 that delivers the coolant to the coolant pump.
The upper cowling piece 14 is provided with a pair of nostril like air inlet openings 113 which receive ram air flowing in the direction of the arrows in Figures 1 and 2 and direct this air to the radiator 103. The air then can exist through a pair of rearwardly positioned ducts 114 formed on opposite sides of the cowling piece 21 so that the heated air flow will be directed away from the handlebar assembly 19. It is desireable to insure that this air flow does not pass across the hands of the rider _ g _ because of the moisture in the air which could chill the rider's hands and body. Therefore, the air flow is clearly directed away from the rider and the rider's comfort is maximized.
The cooling system is also provided with an expansion tank 115 that accommodates for changes in volume of the coolant due to changes in its temperature.
The snowmobile 11 is also provided with a fuel tank 150 that is positioned beneath the body portion 17 and which has a fill neck 153 that can be accessed through a fill opening 154.
The fuel tank 152 supplies fuel to the carburetors 65 in a known manner.
It should be readily apparent from the foregoing description that the described snowmobile embodies an exhaust system that permits pairing of individual cylinders with an exhaust manifold and using plural exhaust manifolds that all communicate with a single silencing device but which will insure that the pulses from the exhaust gases of one cylinder will not travel back to another cylinder. Of course, the foregoing description is that of a preferred embodiment of the invention and various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims.
There is provided further an upper cowling portion 21 which may be removable to access the engine compartment and which carries an upper windshield 22 that is disposed forwardly of the handlebar assembly 19 for affording protection to the riders seated on the seat 18.
A pair of front skis 23 are supported at the forward portion of the body 12 by means of suspension struts 24 which also accommodate steering movement of the skis 23. The struts 24 are interconnected by means of a tie rod 25 so that they may be steered in unison and one of the skis 24 is provided with a steering link 26 which is connected to a steering rod 27 which is, in turn, operated by a steering column 28 that is coupled to the aforementioned handlebar assembly 19.
Rearwardly of the front skis 25, and beneath the seat 18, the body 12 suspends a carriage assembly, indicated generally by the reference numeral 29 by a suitable suspension system and which carriage assembly 29 supports a drive belt, indicated at 31. The drive belt 31 is trained around a driving sprocket 32, which is driven in a manner to be described, and idler sprockets 33 and 34 that are mounted on a pair of rails 35 of the carriage 29. In addition, further idler rolls 36 and 37 are carried by the carriage 29 and engage the drive belt 31 so as to confine and direct its path of movement. The rear idler wheels 37 are carried by frame members 38 of the carriage assembly 26 in a suitable manner.
The engine 16 is disposed transversely in the engine compartment and its output shaft drives a belt driveshaft 39 which extends transversely to the longitudinal center line of the snowmobile 12 as does the -crankshaft or output shaft of the engine l6. This belt driveshaft 39 drives a variable pulley 41 of a variable speed pulley drive mechanism indicatedgenerally by the reference numeral 42. This drive pulley 41 drives a belt 43 which, in turn, drives a driven variable pulley 44 which is affixed to an intermediate shaft 45. The intermediate shaft 45 has affixed to it a sprocket 46 which drives a drive belt 47 which is, in turn, trained around a sprocket that is affixed to a shaft 48 which is also coupled to the belt drive sprocket 32.
The details of the final drive and the engine and its output shaft are set forth more fully in the co-pending Canadian application entitled Power Transmission System For Snowmobile, Serial Number 2,059,395.
Referring now to the remaining figures and initially to Figures 4 and 5 and as has been noted, the engine 16 is of the four cylinder inline type but actually is made up of two, two inline cylinder engines connected end to end. To this end, each of these two cylinder engines comprises a respective cylinder _ 5 _ ~~t~~'~'~ ~!~
block 49 and 51. The cylinder blocks 49 and 51 are, however, connected to a common crankcase assembly 52 which is affixed to the cylinder blocks 49 and 51 in any suitable manner.
The cylinder blocks 49 and 51 slidably support pairs of pistons with the pistons of the cylinder block 49 being disposed so that they fire at 180 degree impulses from each other. In a like manner, the pistons of the cylinder block 51 also fire 180 degrees from each other. The pistons of the cylinder block 49, however, fire at a 90 degree interval from the pistons of the cylinder block 51 so that no two cylinders are firing at the same time, for a reason which will become apparent. The individual cylinders associated with each other cylinder block are designated in Figure 4 by the reference numerals 49a and 49b while those associated with the cylinder block 51 are designated as 51c and 51d. The angular relationship of their firing order is also shown in this figure. The reason for the firing cycle will be described later.
The exhaust ports of the respective cylinder blocks 49 and 51 extend forwardly and terminate in pairs of exhaust ports which communicate with respective paired exhaust manifolds 58 and 59, respectively. The manifolds 58 and 59 have respective pairs of inlet passages 61 and 62 and 63 and 64, respectively, which merge together and terminate in a respective common outlet section 65 and 66. Because the adjacent cylinders of each cylinder block 49 and 51 fire at 180 degrees from each other, it is possible to pair the cylinders through the common inlet passages 61 and 62 and 63 and 64 without any adverse effects on the performance of the engine. That is, no two exhaust ports of the same manifold 58 and 59 will be opened at the same time for any substantial portion of the time that they are open and hence there will be no adverse pulses go back from one exhaust port to the other.
The exhaust manifolds 58 and 59 communicate with respective inlet flanges 67 and 68 of a pair of exhaust pipes 69 and 71.
Spring type fasteners 72 and 73 hold the exhaust pipes 69 and 71 to the exhaust manifolds 58 and 59 while permitting some flexure there between without adversely effecting the seal.
The exhaust manifold 69 and 71 extend forwardly within the engine compartment of the snowmobile 11 and then turn toward one side of the engine, the right hand side in the illustrated embodiment. The intermediate portion of the exhaust pipe 69 and 71 are supported by a pair of frame members 74 and 75 of the body assembly by spring type retainers 76 and 77, respectively.
The exhaust pipes 69 and 71 turn rearwardly and have respective outlet ends 78 and 79 that communicate with respective inlet flanges 80 and 81 of an exhaust silencer device, indicated generally by the reference numeral 82. The exhaust silencer device 82 may have any known type of internal silencing mechanism, depending upon the type of silencing desired and the construction of the particular engine. Coil spring fasteners 83 and 84 respectively couple the exhaust type outlet ends 77 and 78 to the silencer inlet flanges 79 and 81.
The silence 82 is mounted at one end of the engine or at a side of the snowmobile depending upon the frame of reference upon a bracket assembly 90 by means of a spring type fastener 85. A
cushioning construction 86 is interposed between the frame bracket 90 and the silencer 82.
_ 7 _ Because the exhaust pipes 69 and 71 have separate communication with the silencer 82, the pulses which enter the silencer 82 will not flow back-to exhaust ports other than that firing and this reaction is further obtained by the uneven firing impulses between the cylinders, as aforenoted. The silencing device 82 has a downwardly curved discharge end 87 which discharges the exhaust gases to the atmosphere after they have been silenced by the silencing device 82.
The snowmobile engine is water cooled and has a water cooling system of the type as described in co-pending Canadian application entitled Engine Cooling System For Snowmobile, Serial Number 2,059,416. This cooling system includes a water pump driven by the engine output shaft and which circulates water through the engine for discharge through a thermostat 102 positioned on the intake side of the engine and through a transversely extending cross flow radiator 103. In cross flow radiator 103 the coolant is discharged to a heat exchanger system, shown in Figures 1 and 2.
This heat exchanger system is of the type described in more detail in the co-pending Canadian application Wind Leading System For Snowmobile, Serial Number 2,059,415. Basically this heat exchanger system includes the cross flow radiator 103 that is disposed generally above the engine and specifically above the exhaust _ g _ Ao ~~~ L,.t, ~I
manifolds 58 and 59. A conduit 104 communicates the thermostat 102 with the left hand side of the cross flow radiator 103.
Coolant is then delivered from the other side of the cross flow radiator 103 to a conduit 105 that extends along the right side of the snowmobile and which then curves inwardly to communicate with a longitudinally extending heat exchanger 106 that extends along one side of the underside of the seat 18. The seat 18 is constructed and configured so that air can flow across the heat exchanger 106 for its cooling but some heat will also be transferred to the seat 18 so as to warm the riders.
At the rear end of the seat 18, the heat exchanger 106 communicates with a conduit 107 that supplies coolant to a further transversely extending heat exchanger 108. The heat exchanger 108 then communicates with a conduit 109 which delivers the coolant to a further longitudinally extending heat exchanger 111 which extends parallel to the heat exchanger 106 on the other side of the seat 18. The heat exchanger 111 communicates at its forward end with a conduit 112 that delivers the coolant to the coolant pump.
The upper cowling piece 14 is provided with a pair of nostril like air inlet openings 113 which receive ram air flowing in the direction of the arrows in Figures 1 and 2 and direct this air to the radiator 103. The air then can exist through a pair of rearwardly positioned ducts 114 formed on opposite sides of the cowling piece 21 so that the heated air flow will be directed away from the handlebar assembly 19. It is desireable to insure that this air flow does not pass across the hands of the rider _ g _ because of the moisture in the air which could chill the rider's hands and body. Therefore, the air flow is clearly directed away from the rider and the rider's comfort is maximized.
The cooling system is also provided with an expansion tank 115 that accommodates for changes in volume of the coolant due to changes in its temperature.
The snowmobile 11 is also provided with a fuel tank 150 that is positioned beneath the body portion 17 and which has a fill neck 153 that can be accessed through a fill opening 154.
The fuel tank 152 supplies fuel to the carburetors 65 in a known manner.
It should be readily apparent from the foregoing description that the described snowmobile embodies an exhaust system that permits pairing of individual cylinders with an exhaust manifold and using plural exhaust manifolds that all communicate with a single silencing device but which will insure that the pulses from the exhaust gases of one cylinder will not travel back to another cylinder. Of course, the foregoing description is that of a preferred embodiment of the invention and various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims.
Claims (15)
1. An exhaust system for an internal combustion engine the exhaust system comprising a plurality of pairs of exhaust ports, the exhaust ports of each pair being configured and operated so that they do not open at the same time, a plurality of exhaust manifolds each having a pair of inlet openings each cooperating With a respective one of said pair of exhaust ports and a common outlet, and a silencer having a plurality of inlets each receiving exhaust gases from the common outlet of a respective one of said exhaust manifolds and an atmospheric exhaust.
2. An exhaust system as set forth in Claim 1 wherein each exhaust port communicates with an individual chamber of the engine.
3. An exhaust system as set forth in Claim 1 wherein the opening of the exhaust ports of the pairs are spaced at about 180 degrees from each other.
4. An exhaust system as set forth in Claim 1 wherein the engine operates on a two stroke cycle and chambers associated with the associated exhaust ports fire at 180 degrees from each other.
5. An exhaust system as set forth in Claim 4 wherein the opening of the exhaust ports of the pairs are spaced at about 180 degrees from each other.
6. An exhaust system as set forth in Claim 5 wherein the pairs of exhaust ports are associated with pairs of chambers with each pair of chambers being disposed in a respective cylinder block and wherein the cylinder blocks are connected to each other so that individual cylinders of the respective cylinder blocks do not fire at the same time.
7. An exhaust system as set forth in Claim 1 in combination with a snowmobile having a drive belt driven by an output shaft of the engine.
8. An exhaust system as set forth in Claim 7 wherein the engine is disposed with its output shaft extending transversely in an engine compartment of the snowmobile.
9. An exhaust system as set forth in Claim 8 wherein the engine compartment is positioned at the front of the snowmobile and wherein the exhaust manifolds are disposed at the front of the engine.
10. An exhaust system as set forth in Claim 9 wherein the silencer is disposed adjacent at one end of the engine.
11. An exhaust system as set forth in Claim 9 wherein each exhaust part communicates with an individual chamber of the engine.
12. An exhaust system as set forth in Claim 11 wherein the opening of the exhaust ports of the pairs are spaced at about 180 degrees from each other.
13. An exhaust system as set forth in Claim 11 wherein the engine operates on a two stroke cycle and the chambers associated with the associated exhaust ports fire at 180 degrees from each other.
14. An exhaust system as set forth in Claim 13 wherein the opening of the exhaust ports of the pairs are spaced at about 180 degrees from each other.
15. An exhaust system as set forth in Claim 14 wherein the pairs of exhaust ports are associated with pairs of chambers with each pair of chambers being disposed in a respective cylinder block and wherein the cylinder blocks are connected to each other so that the individual cylinders of the respective cylinder blocks do not fire at the same time.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JPHEI3-17070 | 1991-01-16 | ||
| JP1707091A JPH04306187A (en) | 1991-01-16 | 1991-01-16 | Engine exhaust device of snowmobile |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2059434A1 CA2059434A1 (en) | 1992-07-17 |
| CA2059434C true CA2059434C (en) | 2005-11-01 |
Family
ID=11933726
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2059434 Expired - Fee Related CA2059434C (en) | 1991-01-16 | 1992-01-15 | Exhaust system for snowmobile |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH04306187A (en) |
| CA (1) | CA2059434C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8245808B2 (en) * | 2008-10-31 | 2012-08-21 | Bombardier Recreational Products Inc. | Snowmobile exhaust system |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002178980A (en) | 2000-12-08 | 2002-06-26 | Yamaha Motor Co Ltd | Frame structure for snow vehicle |
-
1991
- 1991-01-16 JP JP1707091A patent/JPH04306187A/en active Pending
-
1992
- 1992-01-15 CA CA 2059434 patent/CA2059434C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8245808B2 (en) * | 2008-10-31 | 2012-08-21 | Bombardier Recreational Products Inc. | Snowmobile exhaust system |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2059434A1 (en) | 1992-07-17 |
| JPH04306187A (en) | 1992-10-28 |
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| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |