Information
-
Patent Grant
-
6808433
-
Patent Number
6,808,433
-
Date Filed
Wednesday, February 26, 200321 years ago
-
Date Issued
Tuesday, October 26, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Kadievitch; Natalie D.
- Fredrikson & Byron, P.A.
-
CPC
-
US Classifications
Field of Search
US
- 440 88 G
- 440 88 J
- 440 89 R
- 440 89 B
- 440 89 C
- 440 89 F
- 440 89 J
- 114 5557
-
International Classifications
-
Abstract
An exhaust system for a personal watercraft that places components of the exhaust vehicle on one side of the watercraft, so that the exhaust system takes less space in the watercraft.
Description
BACKGROUND OF THE INVENTION
This invention relates to a small watercraft such as a personal watercraft and, more particularly, to an improved exhaust system therefore.
FIELD OF THE INVENTION
Personal watercrafts are a popular type of watercraft in which one or more passengers ride on, rather than in, the watercraft.
Frequently, these watercrafts are sporting in nature, and the riders expect to leave the watercraft at times during its use and enter into the body of water in which the watercraft is operating.
Presently, one drawback of personal watercrafts is that unwanted noises are generated by the exhaust system upon the discharge of exhaust gases into the atmosphere. The conventional way of resolving this noise problem is to silence the exhaust noises by cooling the exhaust gases either through water jacketing the exhaust system or by dumping cooling water directly into the exhaust system and mixing the water with the exhaust gases. This water coolant is normally drawn from the body of water in which the watercraft is operating and then discharged back into the body of water along with the gases after being circulated through the exhaust system.
In a typical watercraft exhaust system, there is an_exhaust manifold (often part of the engine itself) that discharges gas into an exhaust pipe. From the exhaust pipe, the gases move through an upwardly arched connector pipe or sleeve, an expansion chamber, another connector pipe, a resonator and then out of the watercraft. Generally, cooling water is introduced into the exhaust pipe to silence the noise generated from the exhaust gases. This water then moves along with the exhaust gases through the remainder of the exhaust system and is discharged. The expansion chamber functions to trap the water to prevent it from flowing backwards into the engine. In many watercraft exhaust systems, the expansion chamber is normally positioned lower than the connector pipe connecting the exhaust pipe to the expansion chamber. In other words, this connector pipe is arched upward relative to the exhaust pipe and expansion chamber. Thus, once water reaches the expansion chamber, it is trapped and is difficult to flow backwards towards the engine.
One drawback with such a system is that since the connector sleeve following the exhaust pipe is arched upward, water often remains within the exhaust pipe and is often difficult to move forward. Typically, this water must be blown out of the exhaust pipe when the driver increases the throttle, the initial power blowing both the exhaust gases and the water upward through the connector sleeve and into the expansion chamber. When the watercraft is at low idle, water will not be blown out of the exhaust pipe and will accumulate since there is not enough power to blow it upward through the connector sleeve.
For several reasons, it is undesirable to have water remaining within the exhaust pipe. For one, the remaining water slows down the process of starting up the watercraft. This is because the remaining water must first be blown out of the exhaust pipe before the watercraft can be started. The occupants of the watercraft will often note a sputtering delay in starting the watercraft. That is, the water will sputter out of the watercraft for a few seconds before the engine becomes started. Water remaining in the exhaust pipes may also lead to undesirable corrosion and obstruction.
Thus, there is a need for an improved exhaust system for a personal watercraft capable of more effectively channeling water from an exhaust pipe into an expansion chamber while still allowing the expansion chamber to retain its water trapping functions. There is also a need for an improved watercraft system capable of starting rapidly, without the sputtering delay due to water being blown out.
In addition, there is a need for an improved exhaust system for a personal watercraft that occupies less hull space and can be packaged in a compact configuration. Furthermore, there is a need for an exhaust system that maintains the level of power needed for successful operation of the personal watercraft and allows for backflow protection to the engine.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, there is provided a watercraft having a hull, a propulsion unit, an engine and an exhaust system. The hull is divided in half lengthwise by a centerline and the propulsion device is carried by the hull for propelling the watercraft. The engine is positioned within the hull and drives the propulsion device. The exhaust system delivers exhaust gases from an exhaust port of the engine to the atmosphere and includes an exhaust pipe, an expansion chamber, a first connector sleeve and second connector sleeve. The exhaust pipe is located on a first side of the centerline and is coupled to an exhaust manifold of the engine. The expansion chamber is located on the first side of the centerline. The first connector sleeve is located between the exhaust pipe and expansion chamber and has a proximal end coupled to a first outlet of the exhaust pipe and a distal end coupled to a first input of the expansion chamber. The first connector sleeve is located on the first side of the centerline. The second connector sleeve is located between the expansion chamber and the exhaust port and has a proximal end coupled to a first outlet of the expansion chamber and a distal end coupled to the exhaust port, wherein the second connector sleeve is located on the first side of the centerline.
According to a second aspect of the invention, there is provided an exhaust system for delivering exhaust gases from an exhaust port of an engine to the atmosphere for a small vehicle, the vehicle having an interior region divided by a centerline. The exhaust system includes an exhaust pipe, an expansion chamber, a first connector sleeve and a second connector sleeve. The exhaust pipe is located on a first side of the centerline and coupled to an exhaust manifold of the engine. The expansion chamber is located on the first side of the centerline. The first connector sleeve is located between the exhaust pipe and the expansion chamber and has a proximal end coupled to a first input of the expansion chamber. The first connector sleeve is located on the first side of the centerline. The second connector sleeve is located between the expansion chamber and the exhaust port and has a proximal end coupled to a first outlet of the expansion chamber and a distal end coupled to the exhaust port. The second connector sleeve is located on the first side of the centerline.
According to a third aspect of the invention, there is provided a watercraft having a hull, a propulsion device, an engine and an exhaust system. The hull is divided in half lengthwise by a centerline. The propulsion device is carried by the hull for propelling the watercraft. The engine is positioned within the hull and drives the propulsion device. The exhaust system delivers exhaust gases from an exhaust port of the engine to the atmosphere and includes an exhaust pipe, an expansion chamber, a resonator, a first connector sleeve, a second connector sleeve and a third connector sleeve. The exhaust pipe is coupled to an exhaust manifold of the engine.
The first connector sleeve is located between the exhaust pipe and expansion chamber and has a proximal end coupled to a first outlet of the exhaust pipe and a distal end coupled to a first input of the expansion chamber. The second connector sleeve is located between the expansion chamber and the resonator and has a proximal end coupled to a first outlet of the expansion chamber and a distal end coupled to an input of the resonator. The third connector sleeve is located between the resonator and the exhaust port and has a proximal end coupled to an output of the resonator and a distal end coupled to the exhaust port. The components of the exhaust system are located at least on a first side of the centerline.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a perspective view of a personal watercraft.
FIG. 2
is a perspective view of the exhaust system shown in the hull of a personal watercraft with the deck removed according to a preferred embodiment of the present invention.
FIG. 3
is a schematic view of the exhaust system according to a preferred embodiment of the invention, not drawn to scale, showing exhaust flow through the system.
FIG. 4
is a top schematic view of the exhaust system shown in FIGS.
2
-
3
.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered identically. The drawings depict selected embodiments and are not intended to limit the scope of the invention. It will be understood that embodiments shown in the drawings and described above are merely for illustrative purposes, and are not intended to limit the scope of the invention as defined in the claims that follow.
FIG. 1
illustrates a personal watercraft
20
having generally a front or bow
22
and a rear or stern
23
. The personal watercraft
20
includes a top deck
26
secured to a bottom hull
24
along an overlapping portion covered with a rub rail
30
in the embodiment illustrated, thereby forming a hull. The hull includes an exhaust opening
32
. The hull formed by the bottom hull
24
and top deck
26
define a compartment sized to contain an internal combustion engine
33
for powering the watercraft, and may also include one or more storage compartments, depending upon the size and configuration of the watercraft. The deck portion
26
also has a raised, longitudinally extending seat
28
adapted to accommodate one or more riders seated in straddle fashion on the seat
28
.
Engine
33
powers a jet propulsion unit
34
, typically mounted in a tunnel at the bottom rear portion of the watercraft. Jet propulsion unit
34
includes a steerable water discharge nozzle (not shown) that is operatively connected to a set of handlebars
42
to facilitate steering of the watercraft by the operator. The engine
33
may be of the two or four cycle variety. Of course, the engine
33
may have as few as one, or more than two cylinders, as appreciated by those skilled in the art. In engines of the four-stroke variety, the engine
33
includes a lubricating system (not shown). The lubricating system includes an oil reservoir (not shown) that must be drained and refilled routinely. The hull
24
may be made of any suitable material including molded fiberglass, reinforced resin plastic, and/or a sheet of molding compound.
FIG. 2
is a perspective view of the exhaust system
100
shown in the hull of a personal watercraft with the deck removed according to a preferred embodiment of the present invention. The exhaust system
100
includes an exhaust manifold
102
that is coupled to an engine (see
200
, FIGS.
3
and
4
). Also, the exhaust system
100
includes an exhaust pipe
104
, a first connector sleeve
106
, an expansion chamber
108
, a second connector sleeve
120
, a resonator
110
, a third connector sleeve
124
and an exhaust port
122
. The first connector sleeve
106
is located between the exhaust pipe
104
and the expansion chamber
108
. More particularly, the first connector sleeve
106
has a proximal end
112
coupled to a first output
116
of the exhaust pipe
104
and a distal end
114
coupled to a first input
118
of the expansion chamber
108
. The resonator
110
and expansion chamber
108
are coupled together by a second connector sleeve
120
. The resonator
110
is coupled to an exhaust port (
122
,
FIGS. 3 and 4
) by a third connector sleeve
124
. The first connector sleeve extends from the first output generally upwardly over the exhaust pipe to a point disposed about level with a top of the engine and from that point downwardly to the first input if the expansion chamber. As can be seen in
FIG. 3
, the first output of the exhaust pipe is located at a point disposed about level with a bottom of the engine. In addition, the first output of the exhaust pipe is located at a point lower than the first input of the expansion chamber. The first connector sleeve has a maximum height that is located higher than the exhaust port.
A water drain conduit
126
is coupled between the exhaust pipe
104
and the expansion chamber
108
. More particularly, the water drain conduit
126
has a proximal end
128
coupled to a second output
130
of the exhaust pipe
104
and a distal end
132
coupled to a second input
134
of the expansion chamber
108
. The second input
134
of the expansion chamber
108
is located below the first input
118
of the expansion chamber
108
and the second output
130
of the exhaust pipe
104
is located below the first output
116
of the exhaust pipe
104
. The water drain conduit may be made of metal or a plastic-type material and may be rigid or flexible. In a preferred embodiment, the water drain conduit has an inner diameter ranging from about 0.5 inches to about 1.5 inches. In a preferred embodiment the ratio of inner diameters of the water drain conduit
126
and first connector sleeve
106
is about 1:4.
FIG. 3
is a schematic view of the exhaust system according to a preferred embodiment of the present invention, not drawn to scale, showing exhaust flow through the system. The engine
200
is coupled to the exhaust pipe
104
by exhaust manifold
102
. In a preferred embodiment, part of the exhaust pipe
104
and manifold are cooled by a water jacket
202
. The water jacket
202
has an input
204
that is coupled to a jet pump (not shown). The water jacket
202
includes a conduit
206
that couples part of the water jacket
202
to an input
208
in the exhaust pipe
104
. More particularly, the conduit
206
in coupled to the water jacket
202
at location
210
where there is a filter screen
212
. The flow of the exhaust gases through the exhaust system
100
and the water in the water jacket are shown by the arrows.
The operation of the exhaust system
100
will now be described. Exhaust flows from the cylinders (not shown) of the engine
200
to the exhaust manifold
102
and from the exhaust manifold
102
to the exhaust pipe
104
. The exhaust flows from the exhaust pipe
104
to the expansion chamber
108
and through the expansion chamber
108
to the resonator
110
and out the rear of the vehicle through the exhaust port
122
.
Water is injected into the water jacket
202
at input
204
and is eventually injected in the exhaust pipe at input
208
to reduce the gas temperature and reduce noise. Water is pumped into the water jacket
202
through input
204
from the jet pump (not shown). A portion of the cooling water in the water jacket
202
is diverted by conduit
206
. The water flows through the conduit
206
and is injected inside the exhaust pipe
104
at input
208
. The water cools the exhaust gas from a temperature of about 1,000 degrees Fahrenheit to about 150-200 degrees Fahrenheit. This reduces the heat in the gas before it reaches the portion of the exhaust pipe
104
, first connector sleeve
106
and expansion chamber
108
that are not water jacketed. At high speed, the water is carried with the exhaust gas through the exhaust system
100
. At low speeds water collects in the bottom of the exhaust pipe
104
.
The water drain conduit
126
allows the water to drain from the exhaust pipe
104
to the expansion chamber
108
. Water collects in the expansion chamber
108
. The expansion chamber contains baffles
127
which inhibit water from passing back through the engine exhaust system
100
into the engine. The expansion chamber
108
has an output
214
. Extending into the expansion chamber
108
at output
214
is a pipe
216
. When the water level in the expansion chamber
108
rises to the bottom edge of the pipe
216
, the water is then blown up the pipe
216
and out the rear of the boat with the exhaust through the exhaust port
122
. Without the water drain conduit
126
, water would accumulate in the exhaust pipe
104
at low speeds. When water accumulates in the exhaust pipe
104
, it reduces the rate of acceleration when the engine throttle is opened and makes for a greater risk of water getting inside the engine should the vehicle be overturned.
FIG. 4
is a top schematic view of the exhaust system shown in
FIGS. 2-3
. The location of the various components are shown with respect to the center line of the craft. It can be seen that the exhaust pipe
104
, first connector sleeve
106
, expansion chamber
108
, second connector sleeve
120
, third connector sleeve
124
and exhaust port
122
are all located on a first side of the centerline of the craft. The resonator
110
is located on a second side of the centerline opposite the first side. The engine
200
is located on both the first and second sides of the centerline.
By locating a majority of the exhaust system's components on one side of the centerline of the hull, the exhaust system can be packed in a tight space and thus the exhaust system occupies less hull space. In addition, the layout of the exhaust system provides for a compact configuration and it does not require connector sleeves and components crossing back and forth across the centerline of he hull. In addition, the configuration of the exhaust pipe and first connector sleeve help maintain the level of power needed for successful operation of the personal watercraft. Furthermore, the configuration of the first connector sleeve
106
provides a trap
107
that helps protect the engine from backflow even when the watercraft is inverted. By placing the output of the exhaust pipe
104
away from the expansion chamber
108
, the first connector sleeve
106
can reach the desired height while the separation between the exhaust pipe
104
and expansion chamber
108
remains small.
As can be seen the expansion chamber
108
is located downstream of the exhaust pipe
104
and the resonator
110
is located downstream of the expansion chamber
108
.
While a personal watercraft has been described as a preferred vehicle, it will be recognized that the exhaust system according to the preferred embodiments of the present invention may be used in other types of vehicles such as snowmobiles, ATVs for example, especially where the size and configuration of the engine compartment is a concern.
The above specification provides a complete description of the manufacture and use of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention reside in the claims hereinafter appended.
Claims
- 1. A watercraft comprising:hull divided in half lengthwise by a centerline; propulsion device carried by the hull propelling the watercraft; an engine positioned within the hull, the engine driving the propulsion device; an exhaust system for delivering exhaust gases from an exhaust port of the engine to the atmosphere, the exhaust system comprising: an exhaust-pipe located on a first side of the centerline and coupled to an exhaust manifold of the engine; an expansion chamber located on the first side of the centerline; a first connector sleeve located between the exhaust pipe and expansion chamber, the first connector sleeve having a proximal end coupled to a first outlet of the exhaust pipe and a distal end coupled to a first input of the expansion chamber, wherein the first connector sleeve is located on the first side of the centerline; a second connector sleeve located between the expansion chamber and the exhaust port, the second connector sleeve having a proximal end coupled to a first outlet of the expansion chamber and a distal end coupled to the exhaust port, wherein the second connector sleeve is located on the first side of the centerline a resonator coupled to the second connector sleeve at a point between the second connector sleeve's proximal and distal ends wherein the resonator is located on a second side of the centerline opposite the first side.
- 2. The watercraft according to claim 1 wherein the engine is locate on both first and second sides of the centerline.
- 3. The watercraft according to claim 1 wherein the expansion chamber is located downstream of the exhaust pipe.
- 4. The watercraft according to claim 3, wherein the exhaust port is located downstream of the expansion chamber.
- 5. The watercraft according to claim 1 wherein the hull further defines a rider's compartment having at least one seat and a control for the watercraft disposed forwardly of the seat.
- 6. The watercraft according to claim 5 wherein the seat has a removable portion for accessing the engine.
- 7. The watercraft according to claim 1 wherein the engine is water cooled by coolant drawn from the body of water in which the watercraft is operated.
- 8. The watercraft according to claim 7 wherein at least a portion of the water flowing through the engine for its cooling is discharged into the exhaust pipe.
- 9. An exhaust system for delivering exhaust gases from an exhaust port of an engine to the atmosphere for a small vehicle, the vehicle having an interior region divided by a centerline, the exhaust system comprising:an exhaust pipe located on a first side of the centerline and coupled to an exhaust manifold of the engine, an expansion chamber located on the first side of the centerline; a first connector sleeve located between the exhaust pipe and expansion chamber, the first connector sleeve having a proximal end coupled to a first outlet of the exhaust pipe and a distal end coupled to a first input of the expansion chamber, wherein the first connector sleeve is located on the first side of the centerline; and a second connector sleeve located between the expansion chamber and the exhaust port, the second connector sleeve having a proximal end coupled to a first outlet of the expansion chamber and a distal end coupled to the exhaust port, wherein the second connector sleeve is located on the first side of the centerline a resonator coupled to the second connector sleeve at a point between the second connector sleeve's proximal and distal ends wherein the resonator is located on a second side of the centerline opposite the first side.
- 10. A system according to claim 9 wherein the engine is locate on both the first and second sides of the centerline.
- 11. A system according to claim 9 wherein the expansion chamber is located downstream of the exhaust pipe.
- 12. A system according to claim 11 wherein the exhaust port is located downstream of the expansion chamber.
- 13. A system according to claim 9, incorporated in a watercraft wherein the engine is water cooled by coolant drawn from the body of water in which the watercraft is operated.
- 14. A system according to claim 13 wherein at least a portion of the water flowing through the engine for its cooling is discharged into the exhaust pipe.
- 15. A system according to claim 9 wherein the small vehicle is a personal watercraft comprising:a hull divided in half lengthwise by the centerline; a propulsion device carried by the hull for propelling the personal watercraft; the engine positioned within the hull, the engine driving the propulsion device.
- 16. As system according to claim 15 wherein the hull further defines a rider's compartment having at least one seat and a control for the watercraft disposed forwardly of the seat.
- 17. A system according to claim 16 wherein the seat has a removable portion for accessing the engine.
- 18. A watercraft comprising:a hull divided in half lengthwise by a centerline; a propulsion device carried by the hull for propelling the watercraft; an engine positioned within the hull, the engine driving the propulsion device; an exhaust system for delivering exhaust gases from an exhaust port of the engine to the atmosphere, the exhaust system having components comprising: an exhaust pipe coupled to an exhaust manifold of the engine; an expansion chamber; a resonator wherein the resonator is located on a second side of the centerline; a first connector sleeve located between the exhaust pipe and expansion chamber, the first connector sleeve having a proximal end coupled to a first outlet of the exhaust pipe and a distal end coupled to a first input of the expansion chamber; a second connector sleeve located between the expansion chamber and the resonator, the second connector sleeve having a proximal end coupled to a first outlet of the expansion chamber and a distal end coupled to an input of the resonator; and a third connector sleeve located between the resonator and the exhaust port, the third connector sleeve having a proximal end coupled to an output of the resonator and a distal end coupled to the exhaust port, wherein the components of the exhaust system are located at least on a first side of the centerline.
- 19. A watercraft according to claim 18 wherein the resonator has a portion that is located on a second side of the centerline opposite the first side.
US Referenced Citations (15)