U.S. patent application number 10/778826 was filed with the patent office on 2004-10-14 for exhaust system for v-twin engines.
Invention is credited to Adams, Gar M..
Application Number | 20040200665 10/778826 |
Document ID | / |
Family ID | 33135164 |
Filed Date | 2004-10-14 |
United States Patent
Application |
20040200665 |
Kind Code |
A1 |
Adams, Gar M. |
October 14, 2004 |
Exhaust system for V-twin engines
Abstract
An exhaust system for V-twin engines having a pair of engine
cylinders connected to a crankcase to define a V-space
therebetween. Each of the cylinders includes an exhaust port which
faces outwardly of the V-space, and a pair of mufflers are attached
directly to the exhaust ports of the respective engine cylinders.
In this manner, the exhaust ports and mufflers are disposed outside
of the V-space to promote the ready dissipation of the heat
associated with the exhaust gases to the atmosphere. A common
exhaust conduit is connected to both of the mufflers, and carries
exhaust gases from the mufflers to a common exhaust outlet.
Inventors: |
Adams, Gar M.; (Chilton,
WI) |
Correspondence
Address: |
BAKER & DANIELS
111 E. WAYNE STREET
SUITE 800
FORT WAYNE
IN
46802
|
Family ID: |
33135164 |
Appl. No.: |
10/778826 |
Filed: |
February 16, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60461119 |
Apr 8, 2003 |
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Current U.S.
Class: |
181/240 |
Current CPC
Class: |
F01N 13/10 20130101 |
Class at
Publication: |
181/240 |
International
Class: |
F01N 007/10 |
Claims
What is claimed is:
1. An internal combustion engine, comprising: a crankcase; a pair
of cylinders connected to said crankcase and defining a V-space
therebetween, each cylinder including an exhaust port facing
outwardly of said V-space; a pair of separate mufflers respectively
attached to said exhaust ports; and an exhaust conduit connected to
both of said mufflers, said exhaust conduit including at least one
exhaust outlet.
2. The internal combustion engine of claim 1, wherein said exhaust
ports are disposed on respective sides of said cylinders which are
opposite said V-space.
3. The internal combustion engine of claim 1, wherein said exhaust
conduit includes opposite end portions, said end portions
respectively attached to said mufflers.
4. The internal combustion engine of claim 3, wherein said exhaust
conduit is attached at said opposite end portions to said mufflers
via a slip-fit connection, said exhaust conduit captured between
said mufflers.
5. The internal combustion engine of claim 1, wherein said exhaust
outlet is positioned centrally with respect to said cylinders, said
exhaust outlet directing exhaust outwardly of said engine.
6. The internal combustion engine of claim 1, wherein said exhaust
outlet is positioned adjacent one of said cylinders, said exhaust
outlet directing exhaust gases outwardly to one side of said
engine.
7. The internal combustion engine of claim 1, wherein said
cylinders are disposed in a perpendicular relationship with respect
to one another.
8. The internal combustion engine of claim 1, wherein said mufflers
are attached directly to said exhaust ports.
9. An internal combustion engine, comprising: a crankcase; a pair
of cylinders connected to said crankcase and disposed in an angular
relationship to one another, each said cylinder including an
exhaust port; a pair of separate mufflers respectively attached
directly to said exhaust ports; and a common exhaust conduit
connected between said mufflers, said exhaust conduit including an
exhaust outlet.
10. The internal combustion engine of claim 9, wherein said
cylinders define a V-space therebetween, said exhaust ports
disposed on a side of said cylinders opposite said V-space, said
mufflers disposed externally of said V-space.
11. The internal combustion engine of claim 9, wherein said exhaust
outlet is positioned centrally with respect to said cylinders, said
exhaust outlet directing exhaust outwardly of said engine.
12. The internal combustion engine of claim 9, wherein said exhaust
outlet is positioned adjacent one of said cylinders, said exhaust
outlet directing exhaust gases outwardly to one side of said
engine.
13. The internal combustion engine of claim 9, wherein said
cylinders are disposed in a perpendicular relationship with respect
to one another.
14. The internal combustion engine of claim 9, wherein said exhaust
conduit includes a pair of end portions, said end portions
respectively attached to said mufflers.
15. The internal combustion engine of claim 14, wherein said
exhaust conduit is attached at said opposite end portions to said
mufflers via a slip-fit connection, said exhaust conduit captured
between said mufflers.
16. In combination: an internal combustion engine, comprising: a
crankcase; and two cylinders connected to said crankcase and
disposed in an angular relationship to one another, each cylinder
including an exhaust port; and an exhaust system, comprising: two
separate mufflers respectively attached to said exhaust ports; and
a common exhaust conduit having two end portions respectively
connected to said mufflers, said exhaust conduit including an
exhaust outlet.
17. The combination of claim 16, wherein said end portions of said
exhasut conduit are respectively attached to said mufflers via a
slip-fit connection, said exhaust conduit captured between said
mufflers.
18. The combination of claim 16, wherein said cylinders define a
V-space therebetween, said exhaust ports disposed on a side of said
cylinders which faces outwardly of said V-space.
19. The internal combustion engine of claim 16, wherein said
exhaust outlet is positioned centrally with respect to said
cylinders, said exhaust outlet directing exhaust outwardly of said
engine.
20. The internal combustion engine of claim 16, wherein said
exhaust outlet is positioned adjacent one of said cylinders, said
exhaust outlet directing exhaust gases outwardly to one side of
said engine.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(e) of U.S. Provisional Patent Application Serial No.
60/461,119, entitled EXHAUST SYSTEM FOR V-TWIN ENGINES, filed on
Apr. 8, 2003.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to small internal combustion
engines of the type used with lawnmowers, lawn and garden tractors,
other small working implements, or sport vehicles. In particular,
the present invention relates to an exhaust system for such
engines.
[0004] 2. Description of the Related Art
[0005] V-twin engines generally include a crankcase having a pair
of cylinders, each cylinder including a cylinder bore in which a
piston is reciprocatingly disposed, each of the pistons connected
by a connecting rod to a common crank pin of a crankshaft rotatably
carried within the crankcase. The cylinders are usually disposed at
a 90.degree. angle with respect to one another to define a V-space
between the cylinders, although the angular spacing of the
cylinders may vary. The crankshaft is usually disposed in a
horizontal orientation when such engines are used in snow throwers,
generators, or in sport vehicles, and the crankshaft is usually
disposed in a vertical orientation when such engines are used in
lawnmowers or in lawn and garden tractors. However, the foregoing
configurations and applications may vary.
[0006] The cylinders each include an exhaust port for venting
exhaust from the engine cylinders during running of the engine.
Exhaust pipes communicate the exhaust from the exhaust ports to a
common muffler, which is typically a separate component from the
engine. The muffler is usually attached to the frame of the
implement or machine with which the engine is used using suitable
brackets and fasteners. The muffler may include pipes, baffles, or
other structures therein for reducing the noise associated with the
exhaust, and also includes an outlet for venting the exhaust to the
atmosphere.
[0007] A problem with the foregoing arrangement is that motion
between the engine and the implement, such as vibrations from the
running engine or movement of the implement, may cause fatigue or
failure within the exhaust system at the various connection points
between the components of the system, such as between the exhaust
pipes and the exhaust ports of the engine, or between the exhaust
pipes and the muffler. Additionally, the numerous components of the
exhaust system, such as the exhaust pipes, the muffler, and
attachment hardware, must be separately attached to one another
and/or to the implement with which the engine is used during final
manufacturing of the implement.
[0008] Further, when the exhaust exits directly from the muffler,
the exit point of the exhaust is necessarily directly dependent
upon the location of the muffler itself. While the particular
location of the exhaust outlet may not be important in many
implements with which the engine is used, it may be advantageous or
necessary in some implements to place the exhaust outlet at a
specific location.
[0009] What is needed is an exhaust system for V-twin engines which
is an improvement over the foregoing.
SUMMARY OF THE INVENTION
[0010] The present invention provides an exhaust system for V-twin
engines of the type having a pair of engine cylinders connected to
a crankcase, with a V-space defined between the engine cylinders.
Each of the cylinders includes an exhaust port which faces
outwardly of the V-space, and a pair of mufflers are attached
directly to the exhaust ports of the respective engine cylinders.
In this manner, the exhaust ports and mufflers are disposed outside
of the V-space to promote the ready dissipation of the heat
associated with the exhaust gases to the atmosphere. A common
exhaust conduit is connected to both of the mufflers, and carries
exhaust gases from the mufflers to a common exhaust outlet.
[0011] Advantageously, the exhaust conduit may be configured such
that the exhaust outlet is disposed centrally with respect to the
engine, to one side of the engine, or at any location with respect
to the engine. In this manner, exhaust gases are carried by the
exhaust conduit to a common exhaust outlet, the exhaust outlet
selectively positionable with respect to the engine and/or with
respect to the implement with which the engine is used.
[0012] For example, when the engine is used in a snow thrower
application, the exhaust outlet may be disposed to one side of the
engine and away from the discharge chute of the snow thrower, such
that the hot exhaust gases are vented to the side of the snow
thrower and away from the discharge chute. In this manner, melting
and subsequent re-freezing of snow within the discharge chute is
prevented, which could otherwise clog or impede the flow of snow
through the discharge chute.
[0013] In another example, the engine is used in a generator
application, in which the exhaust outlet is disposed to one side of
the engine, and away from the fuel tank of the engine and the
generator head of the generator.
[0014] In one form thereof, the present invention provides an
internal combustion engine, including a crankcase; a pair of
cylinders connected to the crankcase and defining a V-space
therebetween, each cylinder including an exhaust port facing
outwardly of the V-space; a pair of separate mufflers respectively
attached to the exhaust ports; and an exhaust conduit connected to
both of the mufflers, the exhaust conduit including at least one
exhaust outlet.
[0015] In another form thereof, the present invention provides an
internal combustion engine, including a crankcase; a pair of
cylinders connected to the crankcase and disposed in an angular
relationship to one another, each the cylinder including an exhaust
port; a pair of separate mufflers respectively attached directly to
the exhaust ports; and a common exhaust conduit connected between
the mufflers, the exhaust conduit including an exhaust outlet.
[0016] In another form thereof, the present invention provides, in
combination, an internal combustion engine, including a crankcase;
and two cylinders connected to the crankcase and disposed in an
angular relationship to one another, each cylinder including an
exhaust port; and an exhaust system, including two separate
mufflers respectively attached to the exhaust ports; and a common
exhaust conduit having two end portions respectively connected to
the mufflers, the exhaust conduit including an exhaust outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The above-mentioned and other features and advantages of
this invention, and the manner of attaining them, will become more
apparent and the invention itself will be better understood by
reference to the following description of embodiments of the
invention taken in conjunction with the accompanying drawings,
wherein:
[0018] FIG. 1 is a front perspective view of a V-twin engine
including an exhaust system in accordance with the present
invention;
[0019] FIG. 2 is a rear perspective view of the engine of FIG. 1;
showing an exhaust conduit in accordance with a first
embodiment;
[0020] FIG. 3 is a first exploded assembly view showing an
exemplary manner in which the exhaust system of the engine of FIG.
1 may be assembled;
[0021] FIG. 4 is a rear perspective view of the engine of FIG. 1,
showing an exhaust conduit in accordance with a second
embodiment;
[0022] FIG. 5 is a view of a first exemplary implement with which
the engine of FIG. 1 may be used, the exhaust system including the
exhaust conduit of FIG. 4;
[0023] FIG. 6 is a second exploded assembly view showing an
exemplary manner in which the exhaust system of the engine of FIG.
1 may be assembled;
[0024] FIG. 7 is a sectional view taken along line 7-7 of FIG. 6,
showing the slip-fit connection between the exhaust conduit and a
muffler; and
[0025] FIG. 8 is a view of a second exemplary implement with which
the engine of FIG. 1 may be used, the exhaust system including the
exhaust conduit of FIG. 4.
[0026] Corresponding reference characters indicate corresponding
parts throughout the several views. The exemplifications set out
herein illustrate preferred embodiments of the invention, and such
exemplifications are not to be construed as limiting the scope of
the invention any manner.
DETAILED DESCRIPTION
[0027] Referring first to FIG. 1, a small internal combustion
engine 20 is shown as a horizontal crankshaft V-twin engine, such
as that described in detail in U.S. patent application Ser. No.
10/409,262, entitled INTERNAL COMBUSTION ENGINE, filed on Apr. 8,
2003 (Attorney File Ref.: TEL0633-02), assigned to the assignee of
the present invention, the disclosure of which is expressly
incorporated herein by reference. Although engine 20 is shown as a
horizontal crankshaft V-twin engine, the present invention may be
embodied in vertical crankshaft V-twin engines as well. As
described in further detail below, engine 20 also includes exhaust
system 21.
[0028] Engine 20 generally includes crankcase 22 having a pair of
cylinders 24 which may be mounted to crankcase 22 in the manner
described in the above-incorporated U.S. patent application Ser.
No. 10/409,262. A horizontally disposed crankshaft 26 is rotatably
carried within crankcase 22, and is coupled to a pair of
conventional piston/connecting rod assemblies (not shown), one
corresponding to each cylinder 24. Cylinders 24 are mounted to
crankcase 22 in a manner in which cylinders 24 are disposed at an
approximate 90.degree. angle with respect to one another, with a
V-space 25 between cylinders 24.
[0029] Further details regarding the various user interfaces of
engine 20, including the engine controls, are set forth in detail
in U.S. patent application Ser. No. 10/409,202, entitled ENGINE
CONTROL SYSTEM, filed on Apr. 8, 2003 (Attorney File Ref.:
TEL0683). Also, further details regarding the air intake and air
cleaner system of engine 20 are set forth in detail in U.S. patent
application Ser. No. 10/408,882, entitled AIR CLEANER ASSEMBLY FOR
INTERNAL COMBUSTION ENGINES, filed on Apr. 8, 2003 (Attorney File
Ref.: TEL0681). Each of the foregoing applications are assigned to
the assignee of the present invention, the disclosures of which are
expressly incorporated herein by reference.
[0030] Engine cover or shroud 28 is connected to crankcase 22 and
covers at least a portion of each of crankcase 22 and cylinders 24.
Shroud 28 may be formed of a relatively thin sheet metal, or from
an injection-molded or vacuum-formed plastic material, for example.
Cylinder wraps 30, typically made of a relatively thin sheet metal,
are also connected to crankcase 22 and cylinders 24, and closely
surround cylinders 24 for directing cooling air around cylinders
24. Fuel tank 32 is mounted via brackets 34 to the upper ends of
cylinder wraps 30. Air inlet screen 36 is mounted to shroud 28, and
covers an opening in shroud 28 through which intake air is drawn by
rotation of the engine flywheel (not shown), which is attached to
an end of crankshaft 26 which extends externally of crankcase
22.
[0031] Specifically, rotation of the flywheel draws intake air
through louvers 38 of air inlet screen 36 and into an area defined
between crankcase 22 and shroud 28. The intake air then passes
through an air cleaner assembly, discussed in detail in the
above-incorporated U.S. patent application Ser. No. 10/408,882
(Attorney File Ref.: TEL0681), before entering a carburetor for
mixing with fuel from fuel tank 32 to form an air/fuel combustion
mixture. The air/fuel combustion mixture is conducted by a pair of
intake pipes (not shown) to the intake ports (not shown) of
cylinders 24. The carburetor, intake pipes, and intake ports of
cylinders 24 are each disposed internally within V-space 25.
[0032] Referring to FIGS. 3 and 6, each cylinder 24 includes an
exhaust port 40, which is disposed on a side of each cylinder 24
opposite the intake port of each cylinder 24. In this manner,
exhaust ports 40 of cylinders 24 each face outwardly of V-space 25
toward the sides of engine 20. Exhaust ports 40 terminate in
mounting flanges 42, which extend outwardly of cylinder wraps 30
for attachment thereto of mufflers 44.
[0033] Exhaust system 21 generally includes a pair of mufflers 44
and exhaust conduit 60. One muffler 44 is directly attached to each
exhaust port 40 by suitable fasteners 46, which pass through
apertures 48 in muffler 44 and engage apertures 50 of mounting
flanges 42 of exhaust ports 40. As shown in FIGS. 1-4 and 6,
mufflers 44 are respectively mounted to the outside portions of
cylinders 24, and are disposed on a side of cylinders 24 which is
opposite V-space 25, such that heat from exhaust ports 40 and
mufflers 44 is readily dissipated into the atmosphere around engine
20, and does not collect within V-space 25.
[0034] Mufflers 44 each generally include a pair of shell halves 52
and 54 formed of a suitable metal, such as a relatively thin sheet
metal or stainless steel, for example. The shell halves 52 and 54
include abutting attachment faces, and may be attached to one
another by crimping the peripheral edge of one shell half over the
peripheral edge of the other shell half, for example. Mufflers 44
may include various internal exhaust passages, perforated baffles,
spark arrestors, sound absorbent materials, or catalytic converter
elements therein in order to dissipate the noise associated with
exhaust gases which pass through mufflers 44, and/or to remove
potential contaminant materials from the exhaust gases.
[0035] Exhaust conduit 60 is formed of a relatively heavy gauge
metal or stainless steel, for example, and includes opposite end
portions 62 received within respective outlets 58 of mufflers 44 by
a slip-fit, interference fit, or another suitable manner. As shown
in FIGS. 3, 4, and 7, end portions 62 of exhaust conduit 60 are
each attached to outlets 58 of mufflers 44 via a slip-fit, such
that exhaust conduit 60 is captured between mufflers 44, with
exhaust conduit shown positioned adjacent the rear portion of
engine 20. Alternatively, exhaust conduit may be positioned
adjacent the front portion of engine 20.
[0036] Specifically, referring to FIGS. 6 and 7, end portions 62 of
exhaust conduit are received within openings 58 in shell halves 52
of mufflers which are defined by inwardly-formed lips 53 in shell
halves 52. In this manner, exhaust conduit 60 may be attached to
mufflers 44 concurrently with the attachment of mufflers 44 to
exhaust ports 40, such that separate brackets and fasteners are not
needed to attach exhaust conduit 60 to mufflers 44. For example, as
shown in FIGS. 3 and 6, one muffler 44 may be first attached to its
respective exhaust port 40, followed by attachment of the second
muffler 44 to its exhaust port 40 with concurrent insertion of end
portions 62 of exhaust conduit 60 within outlet openings 58 of
mufflers to capture exhaust conduit 60 between mufflers 44. Thus,
the total number of components needed to assemble exhaust system 21
is reduced, and easy assembly of exhaust system 21 is
facilitated.
[0037] Exhaust conduit 60 may be covered by a protective cage to
prevent incidental contact with exhaust conduit 60, which becomes
heated by passage of exhaust gases therethrough during running of
engine 20. Additionally, exhaust conduit 60 may optionally include
perforations 66, as shown in FIG. 2, for venting exhaust gases at
any location along exhaust conduit 60.
[0038] As shown in FIG. 2, exhaust conduit 60 includes outlet 64
through which exhaust gases may exit exhaust conduit 60. Outlet 64
vents exhaust gasses from both of mufflers 44, and is therefore a
common outlet for mufflers 44. As shown in FIG. 2, outlet 64 is
positioned centrally behind engine 20 and substantially above the
power take-off ("PTO") end of crankshaft 26. Outlet 64 may include
a cover, such as a perforated screen, a mesh material, or a
suitable spark arrestor.
[0039] Alternatively, referring to FIG. 4, outlet 60 of exhaust
conduit 60 may be configured such that it faces to one side of
engine 20 to thereby vent exhaust gases to the atmosphere along one
side of engine 20. Thus, outlet 64 of exhaust conduit 60 may be
selectively positioned or configured in order to vent exhaust gases
from exhaust gas conduit 60 at any desired location around engine
20, depending upon the particular application or implement with
which engine 20 is used.
[0040] For example, referring to FIG. 5, snow thrower 70 is shown,
which generally includes transaxle 72 having wheels 74, and engine
20 mounted above transaxle 72. Handle 76 is mounted to transaxle 72
or another portion of snow thrower 70 to allow same to be
maneuvered and wheeled about by a user. Auger assembly 78 is
mounted to a front end of transaxle 72, and includes auger 80
driven by engine 20 through transaxle 72. Auger assembly 78 also
includes discharge chute 82, through which snow is discharged after
collection by auger assembly 78.
[0041] As shown in FIG. 5, outlet 64 of exhaust conduit 60 is
configured to vent exhaust gases outwardly toward the side of
engine 20 and snow thrower 70, and away from discharge chute 82.
Therefore, the heat associated with the exhaust gases is directed
away from discharge chute 82 such that snow within discharge chute
82 is prevented from melting and re-freezing therewithin, which
could clog or obstruct the flow of snow through discharge chute
82.
[0042] In FIG. 8, generator set 90 is shown, including engine 20
and generator head 92. Engine 20 is mounted to, and supported by,
skid frame 94. Skid frame 94 may include wheels and a handle (not
shown) to allow same to be moved about by an operator. Generator
set 90 may further include additional components (not shown), such
as a control panel, battery, etc., mounted to generator head 92
and/or skid frame 94.
[0043] Generator head 92 is also attached to and supported by skid
frame 94 and further, is operably attached to engine 20 in a manner
in which generator head 92 is driven by crankshaft 26 of engine 20.
As shown in FIG. 8, outlet 64 of exhaust conduit 60 is configured
to vent exhaust gases outwardly toward the side of engine 20 and
skid frame 94. Therefore, the heat associated with the exhaust
gases is directed away from components of generator set 90, such as
fuel tank 32 of engine 20, generator head 92, the control panel of
generator set 92, etc., and to the side of skid frame 94.
[0044] Thus, it can be seen that exhaust assembly 21 of the present
invention allows the directing of exhaust gases from cylinders 24
to a common outlet 64 which may be positioned at any location with
respect to engine 20 in order to accommodate the particular
construction of the implement or machine with which engine 20 is
used.
[0045] While this invention has been described as having a
preferred design, the present invention can be further modified
within the spirit and scope of this disclosure. This application is
therefore intended to cover any variations, uses, or adaptations of
the invention using its general principles. Further, this
application is intended to cover such departures from the present
disclosure as come within known or customary practice in the art to
which this invention pertains and which fall within the limits of
the appended claims.
* * * * *