Note: Descriptions are shown in the official language in which they were submitted.
CA 02794236 2012-10-31
1
VEHICLE EXHAUST SYSTEM
FIELD OF THE INVENTION
100011 The present invention relates to an exhaust system for a vehicle.
BACKGROUND
[0002] Vehicles powered by internal combustion engines are provided with
exhaust
systems connected to the exhaust ports of the engine. The design of the
exhaust system has
an effect on the power output of the engine, the noise level and sound
signature generated by
the engine. The exhaust system also assists in controlling the pollution
generated by the
engine. However, the design choices for an exhaust system that maximizes power
output are
generally contradictory to the design choices for an exhaust system that
minimizes noise level
and optimizes sound signature. A reasonable trade-off therefore has to be
reached in the
design.
[0003] In order to maximize power, it is known to have long exhaust
pipes connected to
the exhaust ports. In order to minimize noise, it is known to include
expansion chambers
such as resonator and mufflers in the exhaust system. Long exhaust pipes and
expansion
chambers take a lot of room in a vehicle.
[0004] In many vehicles, such as off-road side-by-side vehicles (SSVs),
the amount of
room available for the various vehicle components is limited. In a SSV for
example, the
cockpit area has low seats, therefore providing very little room for
components under the
seats, and most of the remaining volume has to be free in order to accommodate
the riders of
the vehicle. The portions of the SSV forward and rearward of the cockpit area
are relatively
short and mostly occupied by the drive train and suspension components (and
steering
components at the front), thus leaving little room for other components. Also,
in view of the
operating conditions of SSVs, typically rough, unpaved terrain, designers of
SSVs try as
much as possible not to have any components extending below the frame of the
vehicle as
these could get damaged. As such, there is not a lot of room to place
components of an
exhaust system, especially one with long exhaust pipes and expansion chambers.
3593 758 I
CA 02794236 2012-10-31
2
[0005] There is therefore a need for an exhaust system for a vehicle
which provides an
acceptable trade-off between engine power output and noise level while fitting
in a limited
amount of space.
SUMMARY
[0006] It is an object of the present invention to ameliorate at least some
of the
inconveniences present in the prior art.
[0007] In one aspect, embodiments of the present invention provide a
vehicle exhaust
system having a first exhaust pipe adapted to be connected to a first exhaust
port of an
engine, a first expansion chamber connected to the first exhaust pipe, a
second exhaust pipe
adapted to be connected to a second exhaust port of an engine, a second
expansion chamber
connected to the second exhaust pipe, a collector connected to the first and
second expansion
chambers, a third exhaust pipe connected to the collector, and a first muffler
connected to the
third exhaust pipe.
[0008] In an additional aspect, a fourth exhaust pipe is connected to
the collector, and a
second muffler is connected to the fourth exhaust pipe.
[0009] In a further aspect, a catalytic converter is connected
downstream of the collector
and upstream of the third exhaust pipe.
[0010] In an additional aspect, exhaust gases from the first and second
exhaust pipes flow
through the catalytic converter.
[0011] In a further aspect, the first and second expansion chambers are
adjacent to each
other.
[0012] In an additional aspect, the first and second expansion chambers
are received in
part inside the collector.
[0013] In a further aspect, the first expansion chamber is a first
resonator and the second
expansion chamber is a second resonator.
[0014] In an additional aspect, the first exhaust pipe extends through
the first resonator.
The first exhaust pipe has an end disposed inside the collector. A portion of
the first exhaust
pipe disposed inside the first resonator defines at least one aperture fluidly
communicating
3593788J
CA 02794236 2012-10-31
3
the first exhaust pipe with the first resonator. The second exhaust pipe
extends through the
second resonator. The second exhaust pipe has an end disposed inside the
collector. A
portion of the second exhaust pipe disposed inside the second resonator
defines at least one
aperture fluidly communicating the second exhaust pipe with the second
resonator.
[0015] In a further aspect, each of the first and second exhaust pipes is
longer than each of
the third and fourth exhaust pipes.
[0016] In an additional aspect, a flow of exhaust gases inside the first
exhaust pipe and the
first expansion chamber is separate from a flow of exhaust gases inside the
second exhaust
pipe and the second expansion chamber. The flow of exhaust gases from the
first exhaust
pipe and the first expansion chamber is mixed with the flow of exhaust gases
from the second
exhaust pipe and the second expansion chamber inside the collector.
[0017] In another aspect, embodiments of the present invention provide a
vehicle having a
frame and an internal combustion engine mounted to the frame. The internal
combustion
engine has a first exhaust port and a second exhaust port. A first exhaust
pipe is connected to
the first exhaust port. A first expansion chamber is connected to the first
exhaust pipe. The
first expansion chamber is disposed rearward of the engine. A second exhaust
pipe is
connected to the second exhaust port. A second expansion chamber is connected
to the
second exhaust pipe. The second expansion chamber is disposed rearward of the
engine. A
collector is connected to the first and second expansion chambers. A third
exhaust pipe is
connected to the collector. A first muffler is connected to the third exhaust
pipe, the first
muffler being disposed rearward of the collector.
[0018] In a further aspect, a fourth exhaust pipe is connected to the
collector, and a second
muffler is connected to the fourth exhaust pipe. The second muffler is
disposed rearward of
the collector.
[0019] In an additional aspect, a catalytic converter is connected
downstream of the
collector and upstream of the third exhaust pipe.
[0020] In a further aspect, exhaust gases from the first and second
exhaust pipes flow
through the catalytic converter.
3593788.1
CA 02794236 2012-10-31
4
[0021] In an additional aspect, the first and second expansion chambers
are adjacent to
each other.
[0022] In a further aspect, the first and second expansion chambers are
received in part
inside the collector.
[0023] In an additional aspect, the first expansion chamber is a first
resonator and the
second expansion chamber is a second resonator.
[0024] In a further aspect, the first exhaust pipe extends through the
first resonator. The
first exhaust pipe has an end disposed inside the collector. A portion of the
first exhaust pipe
disposed inside the first resonator defines at least one aperture fluidly
communicating the first
exhaust pipe with the first resonator. The second exhaust pipe extends through
the second
resonator. The second exhaust pipe has an end disposed inside the collector. A
portion of the
second exhaust pipe disposed inside the second resonator defines at least one
aperture fluidly
communicating the second exhaust pipe with the second resonator.
[0025] In an additional aspect, each of the first and second exhaust
pipes is longer than
each of the third and fourth exhaust pipes.
[0026] In a further aspect, the engine is a V-type engine having a first
cylinder and a
second cylinder. The first exhaust port fluidly communicates with the first
cylinder and faces
generally toward a front of the vehicle. The second exhaust port fluidly
communicates with
the second cylinder and faces toward a rear of the vehicle.
[0027] In an additional aspect, a driver seat is mounted to the frame. The
driver seat has a
seat bottom and a backrest. Two front wheels are mounted to the frame
forwardly of the
driver seat. Two rear wheels are mounted to the frame rearward of the driver
seat. The first
expansion chamber, the second expansion chamber and the collector are disposed
rearward of
the backrest.
[0028] In a further aspect, each of the two rear wheels rotate about a rear
wheel rotation
axis. The first expansion chamber, the second expansion chamber and the
collector are
disposed forwardly of the rear wheel rotation axes.
3593788.1
CA 02794236 2012-10-31
[0029] In an additional aspect, a cargo rack is mounted to the frame
rearward of the
backrest. The first expansion chamber, the second expansion chamber and the
collector are
disposed at least in part below the cargo rack.
[0030] In a further aspect, a driver seat is mounted to the frame. The
driver seat has a seat
5 bottom and a backrest. Two front wheels are mounted to the frame
forwardly of the driver
seat. Two rear wheels are mounted to the frame rearward of the driver seat. A
cargo rack is
mounted to the frame rearward of the backrest. The first and second mufflers
are disposed at
least in part below the cargo rack.
[0031] In an additional aspect, the first and second mufflers are
disposed on opposite sides
of a longitudinal centerline of the vehicle.
[0032] In a further aspect, the first and second expansion chambers each
have an inlet.
The inlets are disposed on a same side of a longitudinal centerline of the
vehicle.
[0033] In an additional aspect, a flow of exhaust gases inside the first
exhaust pipe and the
first expansion chamber is separate from a flow of exhaust gases inside the
second exhaust
pipe and the second expansion chamber. The flow of exhaust gases from the
first exhaust
pipe and the first expansion chamber is mixed with the flow of exhaust gases
from the second
exhaust pipe and the second expansion chamber inside the collector.
[0034] For purposes of the present application, terms related to spatial
orientation when
referring to a vehicle, such as, but not limited to, "forwardly", "rearward",
"front", "rear",
"above", "below", "left" and "right", are as they would be understood by a
driver of the
vehicle sitting in the vehicle in a normal driving position, with the vehicle
in a straight ahead
orientation (i.e. not steered left or right). Terms related to spatial
orientation when referring
to a component of the vehicle should be understood as they would be understood
when the
component is installed in the vehicle.
[0035] Embodiments of the present invention each have at least one of the
above-
mentioned object and/or aspects, but do not necessarily have all of them. It
should be
understood that some aspects of the present invention that have resulted from
attempting to
attain the above-mentioned object may not satisfy this object and/or may
satisfy other objects
not specifically recited herein.
3593788.1
CA 02794236 2012-10-31
6
[0036] Additional and/or alternative features, aspects and advantages of
embodiments of
the present invention will become apparent from the following description, the
accompanying
drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] For a better understanding of the present invention, as well as
other aspects and
further features thereof, reference is made to the following description which
is to be used in
conjunction with the accompanying drawings, where:
[0038] Figure 1 is a perspective view of a vehicle taken from a front,
left side thereof;
[0039] Figure 2 is a left side elevation view of a frame, seats, exhaust
system and rear
wheels support and drive mechanism of the vehicle of claim 1;
[0040] Figure 3 is a rear elevation view of the portions of the vehicle
of Fig. 3;
[0041] Figure 4 is a top plan view of the frame and exhaust system of
the vehicle of Fig.
1;
[0042] Figure 5 is a right side elevation view of the frame, engine and
exhaust system of
the vehicle of Fig. 1;
[0043] Figure 6 is a top plan view of the exhaust system of the vehicle
of Fig. 1;
[0044] Figure 7 is a left side elevation view of the exhaust system of
Fig. 6;
[0045] Figure 8 is a right side elevation view of the exhaust system of
Fig. 6;
[0046] Figure 9 is a front elevation view of the exhaust system of Fig.
6;
[0047] Figure 10 is a rear elevation view of the exhaust system of Fig. 6;
[0048] Figure 11 is a perspective view taken from a rear, right side of
the exhaust system
of Fig. 6;
[0049] Figure 12 is a cross-sectional view of the exhaust system of Fig.
6 taken through
line A-A of Fig. 11; and
3593788.1
CA 02794236 2012-10-31
7
[0050] Figure 13 is a cross-sectional view of an alternative embodiment
of the exhaust
system of Fig. 6 with an alternative embodiment of expansion chambers.
DETAILED DESCRIPTION
[0051] Embodiments of the present invention will be described with
respect to an off-road
side-by-side vehicle (SSV). However, it contemplated that aspects of the
embodiments of the
present invention could also be used on other types of wheeled vehicles, such
as, but not
limited to, all-terrain vehicles (ATVs), motorcycles and snowmobiles.
[0052] Fig. 1 illustrates a SSV 10 having a front end 12 and a rear end
14. The SSV 10
includes a frame 16 to which a vehicle body is mounted. The frame 16 will be
described in
greater detail below. A pair of front wheels 18 is suspended from the front
portion of the
frame 16 via front suspensions 20. A pair of rear wheels 22 is suspended from
the rear
portion of the frame 16 via rear suspensions 24. Each of the four wheels 18,
22 has a tire 26.
It is also contemplated that the SSV 10 could have six or more wheels.
[0053] A cockpit area 28 is disposed in the middle portion of the frame
16. The cockpit
area 28 comprises a driver seat 30 and a passenger seat 32 mounted laterally
beside each
other to the frame 16 to accommodate a driver and a passenger (riders) of the
SSV 10
respectively. Each seat 30, 32 has a seat bottom 34 and a backrest 36. The
cockpit area 28 is
open at the two lateral sides of the SSV 10, forming two lateral passages 38
through which
the riders can ingress and egress the SSV 10. A lateral cover (not shown),
selectively
disposed across each lateral passage 38, can be opened to clear the lateral
passage 38 for
egress or ingress. A cargo rack 40 is mounted to the frame 16 rearward of the
backrests 36 of
the seats 30, 32 as will be described in greater detail below. The cargo rack
40 is surrounded
in part by two side body panels 42. A roll cage 46 is connected to the frame
16 and disposed
above the cockpit area 28.
[0054] An internal combustion engine 48 (shown schematically in Fig. 5) is
mounted to
the middle portion of frame 16 between the seats 30, 32. In the illustrated
embodiment of the
SSV 10, the engine 48 is a V-type engine having a front cylinder 50 and a rear
cylinder 52
disposed at an angle to each other. Each cylinder 50, 52 has an intake port
and an exhaust
port (not shown). The intake ports are connected to an air intake manifold 54
(schematically
shown in Fig. 5). The intake manifold 54 is connected to a throttle body (not
shown)
regulating the flow of air to the engine 48. The exhaust port of the front
cylinder 50 faces
3593788.1
CA 02794236 2012-10-31
8
generally toward the front of the SSV 10. The exhaust port of the rear
cylinder 52 faces
generally toward the rear of the SSV 10. The exhaust ports are connected to
the exhaust
system 200 described below. It is contemplated that other types of internal
combustion
engine could be used, such as, for example, an inline engine. It is also
contemplated that the
engine 48 could have more than two cylinders 50, 52 and that the intake and
exhaust ports
could be oriented differently. A console 56, positioned between seats 30, 32
covers the
engine 48.
[0055] A steering assembly including a steering wheel 58 is disposed in
front of the driver
seat 30. The steering assembly is operatively connected to the two front
wheels 18 to permit
steering of the SSV 10.
[0056] Each front suspension 20 includes lower and upper A-arms 60
pivotally connected
at one end to the frame 16, and at the other end to the corresponding front
wheel 18. A shock
absorber 62 is connected between the outer end of each upper A-arm 60 and the
frame 16. A
sway bar (not shown), disposed rearward of the front suspensions 20, is
connected to both
upper A-arms 60 to increase the roll stiffness of the front suspensions 20.
[0057] Each rear suspension 24 includes lower and upper A-arms 64 (Figs.
2 and 3)
pivotally connected at one end to the frame 16, and at the other end to the
corresponding rear
wheel 22. As can be seen in Fig. 2, the upper A-arm 64 of each rear suspension
24 is
pivotally connected by a linkage 65 to a swing arm 66. The swing arm 66 is
disposed below
the upper A-arm 64 and is pivotally connected to the frame 16 about an axis
that is forward of
the A-arms 64. A shock absorber 67 (Fig. 1) is connected between the outer end
of each
upper A-arm 64 and the frame 16. Toe links 68 are pivotally connected at one
end to the
frame 16, and at the other end to their corresponding rear wheel 22 to
maintain the rear
wheels 22 in a generally straight ahead orientation. The length of the toe
links 68 can be
adjusted to give the rear wheels 22 some toe in or some toe out.
[0058] To drive the front wheels 18, the engine 48 is connected to a
front driveshaft (not
shown), which is in turn connected to a front differential (not shown). The
front differential
transfers the torque from the front driveshaft to left and right half-shafts
70 (only one of
which is shown in Fig. 1). The half-shafts 70 are connected to their
respective front wheels
18. Similarly, to drive the rear wheels 22, the engine 48 is connected to a
rear driveshaft (not
shown), which is in turn connected to a rear differential 72 (best seen in
Fig. 3). The rear
3593788.1
CA 02794236 2012-10-31
9
differential 72 transfers the torque from the rear driveshaft to left and
right half-shafts 74
(Fig. 3). The half-shafts 74 are connected to their respective rear wheels 22.
[0059] The SSV 10 has other features and components such as headlights
and handles. As
it is believed that these features and components would be readily recognized
by one of
ordinary skill in the art, further explanation and description of these
components will not be
provided herein.
[0060] Turning now to Figs. 2 to 5, the frame 16 of the vehicle will be
described in more
detail. For simplicity, only the main elements of the frame 16 will be
described. It is
contemplated that the SSV 10 could have a frame 16 that is different from the
one described
below. The frame 16 has a central frame portion 76, a front frame portion 78
connected to
the front of the central fame portion 76 and a rear frame portion 80 connected
to the back of
the central frame portion 76. As can be seen in Fig. 4, the front and rear
frame portions 78,
80 are narrower than the central frame portion 76.
[0061] The central frame portion 76 defines, together with the roll cage
46, the cockpit
area 28. The central frame portion 76 is also used to mount the seats 30, 32
and the engine
48. The central frame portion 76 has a front upper lateral member 82 and a
rear upper lateral
member 84. A frame member 86 extends downward and rearward from each end of
the front
upper lateral member 76 and then bends near a bottom of the frame 16 to extend
longitudinally rearward. Frame members 88 extend between the rearward ends of
the frame
members 86 to the ends of the rear upper lateral member 84. A cross-member 89
extends
laterally between the members 88. The lower portions of the frame members 86
connect via
cross-members 90 to a lower rectangular frame assembly 92. The frame assembly
92
supports the engine 48. Member 93 extends upward and rearward from the frame
assembly
92 to the rear upper lateral member 84. Members 94 extend downwardly from the
front
upper lateral member 82. Plates 96 extend between the front of the frame
assembly 92 and
the front frame portion 78. A longitudinal member 98 extends longitudinally
between the
seats 30, 32. The member 98 is connected at its front end to the front frame
portion 78 and at
its rear end to the rear frame portion 80. A U-shaped bar 100 is connected at
its ends to the
ends of the front upper lateral member 82 and the member 98. The U-shaped bar
100 extends
upward and rearward from the front upper lateral frame member 82. Another U-
shaped bar
102 is connected to the right side of the U-shaped bar 100. The U-shaped bar
102 serves has
a grab bar for the passenger of the SSV 10. Seat frames 104 are connected to
the cross-
3593788.1
CA 02794236 2012-10-31
members 90, the lower rectangular frame assembly 92, the frame members 88, and
the
longitudinal member 98. The seats 30, 32 are mounted to the seat frames 104.
[0062] The front frame portion 78 provides the connection points for the
front suspensions
and is used to mount the front differential. The front frame portion 78 has
upper and
5 lower trusses 106, 108 connected to the members 94 of the central frame
portion 76. Two
triangular frame assemblies 110 are connected to the front of the trusses 106,
108. Each
triangular frame assembly 110 provides mounting points for its corresponding
front
suspension 20. A bumper 112 is connected to the front of the frame assemblies
110.
[0063] The rear frame portion 80 provides the connection points for the
rear suspensions
10 24 and is used to mount the rear differential 72. The rear frame portion
80 has a trapezoidal
frame assembly 114 connected at its front to the rear of the lower rectangular
frame assembly
92. Two members 116 are disposed above the assembly 114. The members 116 are
connected at their fronts to the cross-member 89 and extend rearward therefrom
parallel to
the sides of the assembly 92. Brackets 118 connect the rear of the members 116
to the rear of
15 the assembly 114. Brackets 120 are also connected between the members
116 and the sides
of the assembly 114 forward of the brackets 118. The brackets 118, 120 provide
the
attachment points for the A-arms 64 of the rear suspensions 24. The rear
differential 72 sits
in the space defined by the assembly 114 and the members 116. Members 122
connect to the
rear ends of the members 116 and extend upward, forward, and laterally outward
therefrom to
20 the rear upper lateral member 84. A cross-member 124 is connected
between the members
122. A generally trapezoidal-shaped tube 126 is connected by members 128 to
the rear upper
lateral member 84 so as to be disposed higher than the member 84. The tube 126
has a
number of brackets 130 (Fig. 4) used to fasten the cargo rack 40 to the tube
128. A member
132 extends downward and forward from the rear part of the tube 126 to the
cross-member
124. The member 132 is disposed along the longitudinal centerline 134 of the
SSV 10.
[0064] Turning now to Figs. 6 to 12, the exhaust system 200 will be
described in more
detail. The exhaust system 200 has an exhaust pipe 202 connected at one end to
one exhaust
port of the engine 48 and to an expansion chamber 204 at the other end and an
exhaust pipe
206 connected at one end to the other exhaust port of the engine 48 and to an
expansion
chamber 208 at the other end. Both expansion chambers 204, 208 are connected
to a
collector 210. The collector 210 is connected to a catalytic converter 212
which is itself
connected to a fitting 214. Two exhaust pipes 216, 218 are connected at one
end to the fitting
359378.I
CA 02794236 2012-10-31
11
214. The other end of the exhaust pipe 216 is connected to a muffler 220. The
other end of
the exhaust pipe 218 is connected to a muffler 222. It is contemplated that
the exhaust pipe
218 and the muffler 222 could be omitted.
[0065] During operation of the engine 48, exhaust gases from the front
cylinder 50 of the
engine 48 flow in the exhaust pipe 202 and then in the expansion chamber 204,
and exhaust
gases from the rear cylinder 52 of the engine 48 flow in the exhaust pipe 206
and then in the
expansion chamber 208. From the expansion chambers 204, 208 the flows of
exhaust gases
mix inside the collector 1210. It should be noted that the flow of exhaust
gases inside the
exhaust pipe 202 and the expansion chamber 204 remains separate from the flow
of exhaust
gases inside the exhaust pipe 206 and the expansion chamber 208 until the two
flows are
mixed in the collector 210. From the collector 210, the exhaust gases then
flow through the
catalytic converter 212. From the catalytic converter 212, the exhaust gases
then enter the
fitting 214 and are separated into two separate flows. From the fitting 214,
part of the
exhaust gases flow inside the exhaust pipe 216, then into the muffler 220 and
out to the
atmosphere, and part of the exhaust gases flow inside the exhaust pipe 218,
then into the
muffler 222 and out to the atmosphere.
[0066] The various components of the exhaust system 200 will now be
described in more
detail
[0067] The exhaust pipe 202 has two main pipe sections 224, 226. It is
contemplated that
the exhaust pipe 202 could be made of a single pipe or of more than two main
pipe sections.
The pipe section 224 has a flange 228 used to fasten the exhaust pipe 202 to
the front of the
front cylinder 50 such that the end of the exhaust pipe 202 fluidly
communicates with the
exhaust port of the cylinder 50. The end of the exhaust pipe 202 that fluidly
communicates
with the exhaust port of the cylinder 50 is disposed on a right side of the
longitudinal
centerline 134 (Fig. 6). From the exhaust port, the pipe section 224 extends
forward and
downward, then rearward, downward and toward the left of the SSV 10, then
rearward, and
finally rearward, upward and toward the right of the SSV 10. As a result, the
pipe section
224 passes under the driver seat 30. The downstream end of the pipe section
224 is inserted
into the upstream end of the pipe section 226. A flange 230 on the downstream
end of the
pipe section 224 is fastened to a flange 232 on the upstream end of the pipe
section 226 via
spring-loaded fasteners 234. A support 236 welded to the downstream portion of
the pipe
section 224 is used to connect the exhaust pipe 202 to a bracket (not shown)
on the central
3593788.1
CA 02794236 2012-10-31
12
frame portion 76. A rubber damper 238 disposed between the support 236 and the
bracket
reduces the transmission of vibrations between the frame 16 and the exhaust
system 200.
From its upstream end, the pipe section 226 extends rearward, upward and
toward the right of
the SSV 10 into the expansion chamber 204. As best seen in Fig. 12, the pipe
section 226
then extends through the expansion chamber 204 and its downstream end is
disposed and
opens inside the collector 210. The inlet 240 of the expansion chamber 204
(i.e. the aperture
through which the pipe section 226 enter the expansion chamber 204) is
disposed on a left
side of the longitudinal centerline 134. The portion of the pipe section 226
that is disposed
inside the expansion chamber 204 has a plurality of apertures 242 fluidly
communicating that
portion of the pipe section 226 with the interior of the expansion chamber
204. It is
contemplated that there could be more or less apertures 242 and/or that the
apertures 242
could be relatively bigger or smaller than illustrated. As such, the expansion
chamber 204 in
the present embodiment is a resonator. Sound absorbing material 244 is
provided inside the
expansion chamber 204 around the pipe section 226. It is contemplated that the
sound
absorbing material 244 could be omitted. As can be seen, the exhaust pipe 202
is longer than
the exhaust pipes 216, 218. As can be seen in Figs. 2 to 5, the expansion
chamber 204 is
disposed rearward of the engine 48 and the backrests 36, forward of the
rotation axes 136 of
the rear wheels 22, and in part below the cargo rack 40.
[0068] The exhaust pipe 206 has four main pipe sections 246, 248, 250,
252. It is
contemplated that the exhaust pipe 206 could be made of a single pipe or of
more or less than
four main pipe sections. The pipe section 246 has a flange 254 used to fasten
the exhaust
pipe 206 to the rear of the rear cylinder 52 such that the end of the exhaust
pipe 206 fluidly
communicates with the exhaust port of the cylinder 52. The end of the exhaust
pipe 206 that
fluidly communicates with the exhaust port of the cylinder 52 is disposed on a
right side of
the longitudinal centerline 134 (Fig. 6). From the exhaust port, the pipe
section 246 extends
rearward and downward, then rearward and upward, and finally rearward and
downward. As
a result, the pipe section 246 passes over the cross-member 89 of the central
frame portion
76. The downstream end of the pipe section 246 is inserted into the upstream
end of the pipe
section 248. A flange 256 on the downstream end of the pipe section 246 is
fastened to a
flange 258 on the upstream end of the pipe section 248 via spring-loaded
fasteners 260.
From its upstream end, the pipe section 248 extends rearward and downward,
then toward the
right of the SSV 10, then rearward toward the right of the SSV 10 and rearward
toward the
left of the SSV 10 in a generally U-shape, and finally toward the left of the
SSV 10 across the
3593788.1
CA 02794236 2012-10-31
13
longitudinal centerline 134. The downstream end of the pipe section 248 is
inserted over the
upstream end of the pipe section 250. A flange 262 on the downstream end of
the pipe
section 248 is fastened to a flange 264 on the upstream end of the pipe
section 250 via spring-
loaded fasteners 266. A support 268 welded to the top of the pipe section 248
is used to
connect the exhaust pipe 206 to a bracket (not shown) on the rear frame
portion 80. A rubber
damper 270 disposed between the support 268 and the bracket reduces the
transmission of
vibrations between the frame 16 and the exhaust system 200. From its upstream
end, the pipe
section 250 extends toward the left of the SSV 10, upward and forward. The
downstream end
of the pipe section 250 has a flange 272 fastened to a flange 274 on the
upstream end of the
pipe section 252 via fasteners 276. From its upstream end, the pipe section
252 extends
forward, upward and toward the right of the SSV 10 into the expansion chamber
208. As
best seen in Fig. 12, the pipe section 252 then extends through the expansion
chamber 208
and its downstream end is disposed and opens inside the collector 210. The
inlet 278 of the
expansion chamber 208 (i.e. the aperture through which the pipe section 252
enter the
expansion chamber 208) is disposed on a left side of the longitudinal
centerline 134. The
portion of the pipe section 252 that is disposed inside the expansion chamber
208 has a
plurality of apertures 280 fluidly communicating that portion of the pipe
section 252 with the
interior of the expansion chamber 208. It is contemplated that there could be
more or less
apertures 280 and/or that the apertures 280 could be relatively bigger or
smaller than
illustrated. As such, the expansion chamber 208 in the present embodiment is a
resonator.
Sound absorbing material 282 is provided inside the expansion chamber 208
around the pipe
section 252. It is contemplated that the sound absorbing material 282 could be
omitted. As
can be seen, the exhaust pipe 206 is longer than the exhaust pipes 216, 218.
As can be seen
in Figs. 2 to 5, the expansion chamber 208 is disposed rearward of the engine
48 and the
backrests 36, forward of the rotation axes 136 of the rear wheels 22, and in
part below the
cargo rack 40.
[0069] The expansion chambers 204, 208 are adjacent to each other such
that the
expansion chamber 208 is disposed above and in contact with the expansion
chamber 204. It
is contemplated that the expansion chambers 204, 208 could be spaced apart. As
best seen in
Fig. 12, the right ends (on the left in Fig. 12) of the expansion chambers
204, 208 are
received inside the left (on the right in Fig. 12), upstream, end of the
collector 210. The left
end of the collector 210 is welded around the expansion chambers 204, 208. As
can also be
seen in Fig. 12, the ends of pipe sections 226, 252 point toward the center of
the collector 210
3593788.!
CA 02794236 2012-10-31
14
and the outlet 284 of the collector 210. The collector 210 is generally funnel-
shaped and
converges from its left end to its outlet 284 (Fig. 12). A flange 286 disposed
around the
outlet 284 of the collector 210 is fastened to a flange 288 on the upstream
end of the catalytic
converter 212 via fasteners 290. As can be seen in Figs. 2 to 5, the collector
210 is disposed
rearward of the engine 48 and the backrests 36, forward of the rotation axes
136 of the rear
wheels 22, and in part below the cargo rack 40.
[0070] As best seen in Fig. 12, the catalytic converter 212 is received
inside the fitting 214
such that a majority of the catalytic converter is housed in the fitting 214.
As can be seen, the
left end of the fitting 214 (on the right in Fig. 12) fits tightly around the
catalytic converter
212. Similarly, the portion of the fitting 214 around the right end of the
catalytic converter
(on the left in Fig. 12) fits tightly around the catalytic converter 212. A
space 292 is defined
between the catalytic converter 212 and the fitting 214 between these tight
fitting portions.
As can also be seen in Fig. 12, the upstream ends of the exhaust pipes 216,
218 extend inside
the chamber defined by the fitting 214 downstream of the catalytic converter
212.
[0071] The exhaust pipe 216 extends through an opening disposed in the rear
of the fitting
214. From the fitting 214, the exhaust pipe 216 extends rearward, upward and
toward the left
of the SSV 10, then forward, downward and toward the left of the SSV 10, and
finally
rearward and upward into the muffler 220. The downstream end of the exhaust
pipe 216 is
received into the muffler 220. It is contemplated that the exhaust pipe 216
could be made of
multiple sections fastened together. The muffler 220 is connected to the
exhaust pipe 216 by
a clamp 294. The muffler 220 is disposed rearward of the collector 210 on a
left side of the
longitudinal centerline 134. As best seen in Fig. 7, the muffler 220 extends
rearward and
upward from its upstream end. The muffler 220 has a number of chambers, pipes
and/or
baffles defined therein. A support 296 welded to the top of the muffler 220 is
used to connect
the muffler 220 to a bracket 298 (Fig. 3) connected to the member 132 on the
rear frame
portion 80. A rubber damper 300 disposed between the support 296 and the
bracket 298
reduces the transmission of vibrations between the frame 16 and the exhaust
system 200. A
support 302 welded to the bottom of the muffler 220 forward of the support 296
is used to
connect the muffler 220 to a bracket 304 (Fig. 3) connected to the member 132
below the
bracket 298. A rubber damper 306 disposed between the support 302 and the
bracket 304
reduces the transmission of vibrations between the frame 16 and the exhaust
system 200. As
can be seen in Figs. 2 to 5, the muffler 220 is disposed in part below the
cargo rack 40.
3593788.!
CA 02794236 2012-10-31
[0072] The exhaust pipe 218 extends through an opening disposed in the
bottom of the
fitting 214. From the fitting 214, the exhaust pipe 216 extends rearward and
downward, and
rearward and upward into the muffler 222. The downstream end of the exhaust
pipe 218 is
received into the muffler 222. It is contemplated that the exhaust pipe 218
could be made of
5 multiple sections fastened together. The muffler 222 is connected to the
exhaust pipe 216 by
a clamp 308. The muffler 222 is disposed rearward of the collector 210 on a
right side of the
longitudinal centerline 134. As best seen in Fig. 8, the muffler 222 extends
rearward and
upward from its upstream end. The muffler 222 has a number of chambers, pipes
and/or
baffles defined therein. A support 310 welded to the top of the muffler 222 is
used to connect
10 the muffler 222 to the bracket 298 (Fig. 3) connected to the member 132
on the rear frame
portion 80. A rubber damper 312 disposed between the support 310 and the
bracket 298
reduces the transmission of vibrations between the frame 16 and the exhaust
system 200. A
support 314 welded to the bottom of the muffler 222 forward of the support 310
is used to
connect the muffler 222 to the bracket 304 (Fig. 3) connected to the member
132. A rubber
15 damper 316 disposed between the support 310 and the bracket 304 reduces
the transmission
of vibrations between the frame 16 and the exhaust system 200. As can be seen
in Figs. 2 to
5, the muffler 222 is disposed in part below the cargo rack 40.
[0073] It is contemplated that the expansion chambers 204, 208, which
are resonators,
could be replaced with another type of expansion chambers. In the exhaust
system 200'
illustrated in Fig. 13, the expansion chambers 204, 208 have been replaced by
expansion
chambers 204', 208' respectively. The expansion chambers 204', 208' are
mufflers.
Although illustrated as each having a single chamber, it is contemplated that
the expansion
chambers 204', 208' could each contain multiple chambers, pipers and/or
baffles. The pipe
sections 226, 252 have been replaced with shorter pipe sections 226', 252'. As
a result, the
pipe sections 226', 252' only extend partly inside their respective expansion
chambers 204',
208'. A pipe 318 connects the expansion chamber 204' with the inside of the
collector 210.
Similarly, a pipe 320 connects the expansion chamber 208' with the inside of
the collector
210. The other elements of the exhaust system 200' are the same as those of
the exhaust
system 200 and have been labeled in Fig. 13 with the same reference numerals.
These
elements will not be described again herein.
[0074] Each main pipe section 224, 226, 246, 248, 250, 252, 226', 252'
and each exhaust
pipe 216, 218 is made of multiple pipe sections welded or otherwise connected
together. For
3593788.1
CA 02794236 2012-10-31
16
simplicity and clarity, these sections were not described. It is contemplated
that each main
pipe section 224, 226, 246, 248, 250, 252, 226', 252' and each exhaust pipe
216, 218 could
also be made of a single bent pipe.
[0075] Modifications and improvements to the above-described embodiments
of the
present invention may become apparent to those skilled in the art. The
foregoing description
is intended to be exemplary rather than limiting. The scope of the present
invention is
therefore intended to be limited solely by the scope of the appended claims.
3593788.1
