Information
-
Patent Grant
-
RE37348
-
Patent Number
RE37,348
-
Date Filed
Tuesday, November 17, 199826 years ago
-
Date Issued
Tuesday, September 4, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Knobbe, Martens, Olson & Bear LLP
-
-
US Classifications
Field of Search
US
- 123 73 AD
- 123 196 W
- 123 495
- 123 447
- 123 451
- 123 507
- 123 509
- 123 508
- 123 195 HC
-
International Classifications
-
Abstract
A number of embodiments of high pressure pumps for internal combustion engines having vertically extending output shafts. In each embodiment, the high pressure pump has its pump driving shaft rotatable about an axis that is parallel to the crankshaft axis and is driven by the crankshaft. This arrangement lends itself to application in outboard motors. The high pressure pump includes an integral lubricating pump for lubricating components of the high pressure pump.
Description
BACKGROUND OF THE INVENTION
This invention relates to a vertical engine of the type employed in outboard motors and more particularly to an improved fuel injection system for such vertical engines.
The use of fuel injection for internal combustion engines in order to improve performance, particularly fuel economy and exhaust emission control, is well known. A wide variety of types of fuel injection systems have been proposed for this purpose. Many of these systems inject the fuel into the induction system rather than into the combustion chamber. Such so-called “manifold injected” engines have advantages over carbureted engines. However, there are a number of additional advantages that can be obtained by utilizing direct cylinder injection.
By using direct cylinder injection, it is possible to more accurately control the actual fuel-air ratio in the combustion chamber on each cycle of operation. In addition, by utilizing direct cylinder injection, it is possible to obtain stratification in the combustion chamber and thus operate under a lean mixture under some or most running conditions. That is, by stratifying the charge in the combustion chamber, it is not necessary to have a homogeneous stoichiometric charge in the entire combustion chamber. All that is required is to have a stoichiometric charge present in the vicinity of the spark plug at the time that it is fired in order for combustion to be initiated.
There are, however, a number of reasons why direct cylinder injection is not utilized more widely. Not the least of these is cost. Not only are the injectors more costly and more critical with direct injected engines, but the supply system for supplying fuel to the injectors also becomes more complicated and expensive.
When direct cylinder injection is employed, the injection pressures must not only be higher, but they also must be more accurately controlled. As a result of this, it has been the practice to normally employ reciprocating plunger-type pumps for direct injected engines. Such pumps have a number of components, are complex, and in fact, can become quite bulky.
Although these problems may be overcome in some applications, there is a desire to employ direct cylinder or high pressure fuel injection systems for outboard motors. Like other vehicle applications, outboard matters are subject to concern over environmental control and also fuel economy. In addition, outboard motors frequently utilize two-cycle engines as their power plants. These engines can benefit as much or more from direct cylinder fuel injection as four-cycle engines.
In addition to the cost factor, the complexity of high pressure injection systems makes it more difficult to integrate them into outboard motors. One reason for this is that the outboard motor is a very compact type of device, and it may be difficult to locate the necessary components for a high pressure fuel injection system. In addition, the injection pump normally is driven off of the engine crankshaft and frequently in timed relationship thereto. This further complicates the placement and driving of such high pressure fuel injection pumps in outboard motors.
In addition to these problems, an outboard motor has another problem which is somewhat unique and different from automotive or other vehicle applications. That is, it is normally the practice to mount an outboard motor engine so that its crankshaft rotates about a vertically extending axis. As a result, the orientation of the engine is quite different than automotive and other applications. This further complicates the location and driving of accessories, such as high pressure fuel injection pumps.
When utilizing plunger or piston type high pressure fuel injection pumps, there are a number of mechanical components which are subject to wear. The fuel may not contact all of these components and in many instances, even if the fuel did, it does not have sufficient lubrication properties in order to prevent wear on the components.
For these reasons, it has also been the practice at times to incorporate a separate lubricating system for certain components of the high pressure pump. However, when the engine is mounted so that it its output shaft extends vertically, this further complicates the lubrication system for the fuel injection system and its high pressure pump.
It is, therefore, a principal object of this invention to provide an improved high pressure fuel injection pump for an internal combustion engine.
It is a further object of this invention to provide an improved high pressure fuel injection pump for a vertically disposed engine.
It is yet another object of this invention to provide an improved, compact and high efficiency fuel injection system for an outboard motor.
It is still another object of this invention to provide an improved high pressure fuel injection pump that can be operated with its driving shaft extending in a vertical direction.
It is a still further object of this invention to provide an improved lubricating system for such a vertically disposed high pressure pump.
SUMMARY OF THE INVENTION
This invention is adapted to be embodied in a fuel injected internal combustion engine having an output shaft rotatable about a vertically extending output shaft axis and driven by the combustion occurring in a combustion chamber. A high pressure piston pump is driven by a rotating pump drive shaft that is journaled for rotation about a vertically extending pump drive shaft axis that extends parallel to the engine output shaft axis. Pump driving means are provided for driving the pump drive shaft from the output shaft. A lubricant pump is driven off one end of the pump drive shaft for pumping lubricant to elements of the high pressure pump.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a top plan view of an outboard motor constructed in accordance with an embodiment of the invention, with the protective cowling shown in phantom and also illustrating alternate positions for the high pressure fuel injection pumps in phantom.
FIG. 2
is a schematic view showing the components associated with the fuel injection system, including the high pressure fuel injection pump.
FIG. 3
is an enlarged view which is partially in cross-section through the high pressure pump in accordance with one embodiment of the invention and shows the system components, in part schematically, and thus is related closely to FIG.
2
.
FIG. 4
is a cross-sectional view taken along the line
4
—
4
of FIG.
3
.
FIG. 5
is a cross-sectional view, in part similar to
FIG. 3
, and shows another of the pump embodiments, which is also shown in phantom lines in FIG.
1
.
FIG. 6
is a cross-sectional view taken along the line
6
—
6
of FIG.
5
.
FIG. 7
is a partial cross-sectional Kew taken through the cylinder block of a high pressure fuel injection pump constructed in accordance with another embodiment of the invention, which embodiment is also shown in phantom in FIG.
1
.
FIG. 8
is a cross-sectional view taken along the line
8
—
8
of
FIG. 7
, and shows certain other components of the system schematically.
FIG. 9
is a cross-sectional view, in part similar to
FIGS. 4 and 6
, and shows another embodiment of the invention.
FIG. 10
is a cross-sectional view, in part similar to
FIGS. 4
,
6
and
9
, and shows yet another embodiment of the invention.
FIG. 11
is a partial cross-sectional view, in part similar to
FIGS. 4
,
6
,
9
and
10
, and shows still another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
Referring now in detail to the drawings and initially to
FIG. 1
, an outboard motor constructed in accordance with an embodiment of the invention is shown partially, with certain components being shown in phantom as well as alternative constructions being shown in phantom, and with portions broken away so as to more clearly show the construction of the basic engine. The invention is described in conjunction with an outboard motor because the invention has particular utility in conjunction with applications where a very compact construction is required, as is the case with outboard motors. In addition, the engine is depicted in conjunction with an outboard motor because outboard motors normally have their crankshafts rotatable about vertically extending axes, and the invention has particular utility in conjunction with engines having such orientations. Finally the invention also has particular utility, but is not so limited, for use with two-cycle crankcase compression internal combustion engines, and such engines are frequently employed as the power units in internal combustion engines.
Because of the fact that the invention deals primarily with the fuel injection system, and specifically the high pressure fuel injection pump therefore, components of the outboard motor which are not necessary to understand the invention are not illustrated. It will be readily apparent to those skilled in the art how the invention can be practiced in conjunction with any known type of outboard motor, if that is the specific application for the invention. Also, the details of the powering internal combustion engine, which engine is indicated generally by the reference numeral
22
, will be described only briefly in order to permit those skilled in the art to understand the orientation of the invention and how it can be utilized with engines of varying types.
In the illustrated embodiment, the engine
22
is depicted as being a V-6, two-cycle, crankcase compression engine, but for the reasons already mentioned, it will be apparent to those skilled in the art how the invention can be utilized with a wide variety of types of engines and engine configurations. In addition, although the invention is described in conjunction with a reciprocating engine, it should also be apparent to those skilled in to an that the invention can be utilized with a wide variety of OEM types at engines, such as rotary engines.
The engine
22
is comprised of a cylinder block
23
which is provided with a pair of angularity disposed cylinder banks
24
. Each cylinder bank
24
is formed with three in-line, horizontally extending cylinder bores in which pistons
25
reciprocate. As is typical with V-type engine practice, the cylinder banks
24
may be staggered axially relative to each other so that connecting rods, indicated by the reference numeral
26
, can connect the pistons
25
to common throws of a crankshaft
27
.
The crankshaft
27
is rotatably journaled within a crankcase chamber
28
that is formed in part by the cylinder block
23
and by a crankcase member that is affixed thereto in any known manner. As is well known in two-cycle crankcase compression engine practice, the crankcase chamber
28
is divided into individual sealed portions, each associated with a respective one of the cylinder bores in which the pistons
25
reciprocate.
The engine
22
is confined within a surrounding protective cowling that is shown in phantom and identified by the reference numeral
29
. Thus, the engine
22
and protective cowling
29
form the powerhead of be outboard motor the vertical disposition of the crankshaft
27
permits its attachment to a drive shaft (not shown) that depends from this powerhead through a drive shaft housing into a lower unit for driving a propulsion unit for propelling an associated watercraft, as is well known in this art.
The protective cowling
29
is formed with a suitable atmospheric air inlet device which preferably is designed so as to permit air to be drawn in for the operation of the engine
22
while, at the same time, excluding water from entering within the protective cowling
29
. This air is then delivered to an induction system, which is indicated generally by the reference numeral
31
, through an air inlet device
32
of that induction system.
The air inlet device
32
may include internal baffling for accomplishing silencing of the inducted air. Air is delivered from the air inlet device
32
through intake pipes
33
to an intake manifold
34
. The intake manifold
34
has individual passages
35
that serve the individual crankcase chambers
29
. A throttle valve assembly (not shown) may be mounted in this intake manifold
34
or in the intake pipes
33
for controlling the speed of the engine.
Reed-type check valves
36
are disposed in each of the manifold runners
35
so as to permit a charge to be drawn into the crankcase chamber portions
28
when the pistons
25
are moving upwardly. When the pistons move downwardly, these reed-type check valves
36
will close and permit the inducted charge to be compressed in the crankcase chambers
28
.
Combustion chambers are formed by the heads of the pistons
25
, the cylinder bores in which they reciprocate, and by cylinder head assemblies
31
which an affixed to the cylinder banks
24
in any known manner, such as by the illustrated but unnumbered fasteners. Each cylinder head assembly
37
has a plurality of recesses
38
which complete the formation of these combustion chambers. The combustion chamber recesses
38
may, at times, be referred to as the combustion chambers since, at top dead center, they comprise the substantial clearance volume of the engine, as best seen in the left-hand side of
FIG. 1
, wherein the piston
25
is shown at this top dead center position.
The charge which has been drawn into the combustion chambers
28
through the induction system
31
and compressed therein is transferred to these combustion chambers
38
through one or mum scavenge passages
39
formed in the cylinder block
23
. This charge is then further compressed in to combustion chambers
38
and eventually fired by a spark plug
41
. Obviously, there is and least one spark plug mounted is each cylinder head
37
for each cylinder. The spark plugs
41
are fired by a suitable ignition system in appropriate timed relationship.
As has been noted, the cylinder heads
37
are assemblies, and these include cover pieces
42
which assist in the formation of water cooling jackets
43
for water cooling of the engine. Such cooling jackets are also formed in other components of the engine
22
as is well known in this art. Water is drawn from the body of water in which the outboard motor operates for circulation through these water jackets in any manner known in this art.
Suitable high pressure fuel injectors, shown schematically and indicated by the reference numeral
41
are also mounted in the cover plates
42
and cylinder head assemblies
37
. These fuel injectors
44
are supplied with high pressure fuel from a fuel supply system which will be described later, and which forms the primary portion of the invention Thus, when the fuel-air mixture is present in the combustion chambers
38
and fired by the spark plugs
41
, the charge will burn and expand and drive the pistons
25
downwardly to drive the crankshaft
27
.
The charge is then expelled through exhaust ports formed in the cylinder block
23
and which communicate with an exhaust manifold
45
formed in the valley between the cylinder banks
24
. This exhaust manifold
45
is also formed by a cover plate assembly
46
which has a further water jacket for cooling of the exhaust manifold
45
. As is typical with outboard motor practice, the exhaust manifold
45
has one or more collector sections, depending upon whether me cylinder banks
24
share a manifold or have separate manifolds.
This collector section extends downwardly and discharges the exhaust gases through an exhaust system, which is typically formed in major part in the drive shaft housing of the outboard motor, as is well known in this art. For the reasons already described, it is not believed that a further description of this known portion of the construction is required to permit those skilled in the art to practice the invention.
The construction of the engine
22
as thus far described may be considered to be conventional, as it has already been noted. For that reason, any further description of the basic structure of the engine
22
or the outboard motor
21
, for that part, is believed to be unnecessary to enable those skilled in the art to practice the invention.
The fuel injection system will now be described in detail, initially primarily to the schematic view of FIG.
2
. It has been noted that the fuel injectors
44
are of any known high pressure type. Since the invention deals primarily with the high pressure fuel injection pump, indicated generally by the reference numeral
47
, the details of the fuel injectors
44
and other components of the injection system will be general in nature, and most of these components are illustrated merely schematically. Again, it will be readily apparent to those skilled in the art how the invention can be practiced in conjunction with any type of conventional components.
There is provided a remotely positioned fuel storage tank
48
which, in typical outboard motor practice, is positioned remotely within the hull of the associated watercraft. Obviously, however, the fuel tank
48
may be contained within the powerhead of the outboard motor
21
, or a small supply tank may be thus located that is served by a remote main tank.
An electrically driven low pressure fuel pump
49
is submerged in the fuel tank
48
below the fuel level therein and discharges fuel through an outlet fitting
51
. This fuel flows in the direction shown by the arrow
52
through a fuel filter
53
, which may be located in the powerhead somewhere within the protective cowling
29
to facilitate servicing. This fuel is then supplied through a conduit
54
to the delivery inlet
55
of die high pressure pump
47
. A low pressure regulator
56
regulates the pressure at which fuel is supplied to the high pressure pump
47
.
Before describing the details of the high pressure pump
47
, the remaining components of the system will be described.
The high pressure pump
47
supplies fuel under a high pressure in pulsed intervals through a pressure conduit
57
to an accumulator
58
. The accumulator
58
has an inlet fitting
59
to which the fuel is delivered. The pressure in the accumulator
58
may be controlled by an electronic control
61
under the direction of a CPU, indicated generally by the reference numeral
62
. This control
61
may also include a distributor arrangement for delivering fuel through respective conduits
63
to the fuel injectors
44
.
It should be noted tat
FIG. 2
shows three fuel injectors
44
which are the fuel injectors associated with one cylinder bank. It has been noted already that the engine
22
is a V-6 engine and hence, there is another bank of fuel injectors. As will become apparent later, the high pressure pump
47
may have banks of plungers or may be of an in-line type, and this will determine to some extent how the fuel is actually supplied from the pump
47
to the individual injectors
44
. Again how this is done forms no major part of the invention.
Returning now to the description of the CPU
62
, this CPU
62
may have any control strategy that operates on input signals from a wide variety of sensors. In the illustrated embodiment, two such sensors are illustrated. These sensors comprise an engine speed sensor
64
which supplies signals not only of engine speed but of crank angle, and an operator demand sensor or load sensor, such as a throttle sensor
65
. Obviously, those skilled in the art will readily understand how the invention may be practiced with a wide variety of types of control strategies.
It has been noted that the low pressure fuel regulator
56
regulates the low pressure supplied to the high pressure pump
47
, and the control
61
of the accumulator
58
regulates the pressure therein. These pressures are regulated by dumping excess fuel back to the fuel tank
48
through respective return conduits
66
and
67
, as is well known in this art.
The construction of the high pressure pump
47
will now be described in detail by reference to
FIGS. 3 and 4
, where the actual construction of the pump is shown, although certain of the auxiliaries associated with it are shown in phantom. The pump
47
is comprised of a main housing assembly
68
which, in the illustrated embodiment, has a pair of opposed cylinder banks
69
. In the illustrated arrangement, each bank
69
contains one pumping assembly. It will be readily apparent to those skilled in the art, however, that the number of pumping assemblies employed can be increased, and one way in which this may be done will be described later, when the actual pumping mechanisms are described.
The banks
69
are each provided with respective cylinder heads
71
that are affixed thereto in any known manner. The cylinder head of one bank is provided with a T-shaped fitting
72
that receives the end of the conduit
54
for supply thereto. The T-fitting
72
has a branch that supplies a further conduit
73
which extends, as indicated at a, to a corresponding inlet fitting
74
of the cylinder head
71
of the other cylinder bank.
The construction of these cylinder heads
71
appears in most detail in FIG.
4
. It will be seen that each cylinder head
71
includes a delivery check valve
75
that cooperates with an inlet fitting
76
to permit the fuel to be drawn into a pumping chamber
77
. This pumping chamber
77
communicates with a pumping bore
78
in which one end of a pumping plunger
79
is slidably supported. An O-ring seal
81
encircles the pumping plunger
79
and provides a fluid seal therearound.
The pumping plunger
79
is reciprocated, in a manner to be described, and when the volume of the pumping chamber
77
is increasing, fluid will be drawn into this pumping chamber through die opening of the delivery check valve
75
. When the volume of the pumping chamber
77
is being decreased by the upward movement of the pumping plunger
79
, high pressure will be generated and it will open a discharge check valve
82
to permit fluid to be discharged through a fitting
83
to the conduit
57
which communicates with the accumulator chamber
58
. An outlet fitting
84
is provided for communication between the fitting
83
and the conduit
57
.
Turning now to the operation for reciprocating the pumping plungers
74
, it will be seen that the banks
69
of the housing assembly
68
are formed with bores
85
that are concentric with the pumping chamber portion
78
. The pumping plungers
100
have a shank portion
86
that has a yoke part
87
at its bottom end that A urged by a coil compression spring
88
into engagement with a piston or tappet-type actuator
89
. At the opposite end, the spring
88
acts against a closure plug
91
that closes the upper end of the bore
85
and which slidably supports the pumping plunger
79
. An O ring seal
90
seals the plugs
91
to the housing
69
.
The piston or tappet actuator
89
is held against rotation by means of a set screw
92
and carries a roller follower
93
which is journaled on a shaft
94
by a needle-bearing assembly
95
. The spring
88
in addition to urging the pump plunger yoke
87
into engagement with the actuating tappet
89
, also urges the tappet into engagement with a drive cam
96
of a pump drive shaft, indicated generally by the reference numeral
97
.
Referring now primarily to
FIG. 3
, it will be seen that the housing assembly
68
has an upwardly extending cylindrical portion
98
and a downwardly extending larger diameter cylindrical attachment piece
99
. The upper portion
98
rotatably journals the pump drive shaft
97
through a first thrust bearing
101
. Disposed above the thrust bearing
101
is an oil set
102
that defines a lubricant receiving chamber
103
, for a purpose which will be described.
The pump drive shaft
97
continues upwardly into and through a cover plate
104
that is held in place by threaded fasteners
105
. This cover plate
104
permits the pump drive shaft to enter into a drive cavity formed by a timing drive cover
106
that is comprised of a lower portion
107
and an upper portion
108
, which may be of any known construction and which are shown primarily in phantom in the figures. Reference also should be had to
FIG. 1
for this construction.
This contains a timing drive, indicated generally by the reference numeral
109
, which consists of a chain
111
or other flexible transmitter such as a toothed belt that is driven by a drive sprocket
112
that is affixed to either the upper or lower end of the crankshaft
27
. This drive chain
111
is in engagement also with a the sprocket
113
that is held to the upper end of the pump drive shaft
97
by means of a retainer plate assembly
114
and a nut
115
threaded onto the upper end of the pump drive shaft
97
. Finally, a drive key
116
interconnects the sprocket
113
with the pump drive shaft
97
to provide a timed driving connection therebetween.
Referring now again primarily to
FIG. 3
, the lower end of housing attachment
90
as has been noted, is of a larger diameter than the upper portion
90
This is to permit it to form a combined oil reservoir and pump cavity
117
, the lower end of which is closed by a closure plate
118
. An oil pump assembly, indicated generally by the reference numeral
119
, is driven off of the lower end of the pump drive shaft
97
. This oil pump assembly
119
may be comprised of a gerotor-type pump that realms oil in a pumping cavity
121
from the reservoir
117
and pressurizes it. Oil is delivered through delivery ports
122
and
123
.
The oil is pumped under high pressure through a first conduit
124
that extends axially through the pump drive shaft
97
from the pumping cavity
121
, and specifically its outlet, to a cross-drilling
125
that communicates with the lubricant cavity
103
so as to lubricate the upper bearing
101
. This lubricant then flows downwardly so as to lubricate the cams
96
, roller followers
93
, needle bearings
95
and pin
94
. In addition, same of this lubricant will also lubricate the lower end of the pump driving pistons or tappets
89
. An oil cavity
126
is formed around the pump driving elements for assisting in this lubrication.
The lower pump housing portion
99
supports a second thrust bearing
127
which receives the down-flowing lubricant from the cavity
126
and permits it to drain back into the reservoir cavity
117
.
In addition to this lubricant path, the pump
119
further delivers lubricant under pressure through a passageway
128
formed between the pump housing member
99
and the cover plate
118
, which communicates with a further main supply passageway
129
. The main supply passageway
129
extends upwardly, as shown in
FIG. 4
, and intersects a drilled passageway
131
which is drilled through the pump housing
69
, and is intersected by a pair of cross-drillings
132
, each of which extends to the respective plunger supporting closure elements
91
, These elements are provided with cross-drillings that extend from circumferential grooves
133
formed therein to inner circumferential grooves
134
that surround the pump plungers
79
. These cross-drillings are indicated by the reference numeral
135
in the drawings. This oil will flow into the bores
85
and can drain back into the cavity
126
for return to the reservoir
117
.
As should be readily apparent from the foregoing description, the configuration and orientation of the high pressure pump
47
permits it to be conveniently mounted in the valley between the cylinder heads
37
adjacent the pressure accumulator
58
so as to provide a very compact assembly and one which is located close to the actual fuel injectors
44
so as to minimize the length of the conduits. In addition, the vertical disposition of the pump drive shaft
97
permits it to drive its own lubricating pump off the lower end thereof, and lubricant can be returned to the reservoir of this pump through a gravity return system. Hence, the structure is not only compact, but it is also well lubricated and well protected.
A high pressure oil pump constructed in accordance with another embodiment of the invention is illustrated in
FIGS. 5 and 6
and is indicated generally by the reference numeral
201
. The pump
201
is employed in a system of the type as previously described and thus, many components associated with this pump are the same or substantially the same and have been identified by the same reference numeral when that is the case.
In the previously described embodiment, the high pressure pump
47
was of the opposed piston type, whereas the embodiment of
FIGS. 5 and 6
shows an in-line type of pump. Therefore, the pump body
202
is formed with in-line bores that receive the plunger mechanisms and which are closed by a cylinder head assembly, indicated generally by the reference numeral
203
. Each pumping unit is the same as that previously described and, for that reason, the components of the pumping elements which are the same in construction and operation as those already described have been identified by the same reference numerals and will be described again only insofar as is necessary to understand the construction and operation of this embodiment.
The drive for the pump shaft
97
is also the same as that previously described and, for that reason, this mechanism also will not be described again in detail. In this embodiment, since the outer housing
202
is formed with aligned cylinder bores that receive the pumping plunger actuating pistons or tappets
89
, it is higher than the previously described embodiment. However, because of this disposition, it is shorter in width and thus can be located, for example, on one side of one of the cylinder banks
24
. Such an alternative location is shown in
FIG. 1
by the phantom line view.
In view of this location, a shorter drive chain
204
or a flexible timing belt may be employed, which is still driven by the crankshaft sprocket
112
and which drives the pump shaft
97
by a pump drive sprocket
113
. This type of pump lends itself better to an arrangement wherein it is utilized with an in-line engine, but can be utilized with a V-type engine with either a slot pump on one side of the one cylinder bank
24
or with individual pumps on one side of each cylinder bank, as illustrated.
As may be seen, the pump drive shaft, therefore, has three pump actuating cams
96
-
1
,
96
-
2
and
96
-
3
. As has been previously noted, the V-type or opposed-type pump, like the pump
47
, may also be employed with multiple plunger cylinders, and these would embody such an extended cam shaft having a greater number of pump plungers.
With this arrangement, however, there is a simpler disposition of the manifolding for supplying fuel to and from the pump
201
and accordingly, a single fluid inlet conduit
205
may be provided that supplies all of the delivery valves
75
for this embodiment. The communication between the delivery valves
15
can be formed internally in the cylinder head
203
. In addition, a single pump discharge fitting
206
can be mounted in the cylinder head
203
and is served by internal conduits which communicate with each of the pump delivery check valves
82
.
Because of the greater length of the pump shaft
97
in this embodiment, a different arrangement is provided for the lubricant and the reservoir therefore. In this embodiment, a gerotor-type pump, indicated generally by the reference numeral
207
and having a pumping cavity
208
, is formed between a lower housing member
209
that is fixed to the main housing member
202
in a suitable fashion, and closed by a closure plate
211
. A drain reservoir
212
below the lowermost pump drive shaft bearing
127
collects the oil and returns it to the pumping cavity
208
through a drain passageway
213
. The lubricant is then delivered under pressure by the pumping element of the gerotor pump
207
to a high pressure discharge
214
which communicates with a delivery passage
215
. The passage
215
, in turn, communicates with a fitting
216
and through a pressure responsive check valve
217
with an oil reservoir
218
. A port
219
in the housing piece
202
permits this communication.
A discharge passageway
221
extends from this reservoir cavity
218
to an oil delivery check valve
222
positioned in a pressure fitting
223
. The pressure fitting
223
communicates with a drilled passageway
224
(
FIG. 6
) which, in turn, supplies oil to the oil delivery grooves
133
of each of the pump plunger supports
91
in this embodiment.
A separate passageway (not shown) may extend from the pump pressure cavity
214
to a point above the uppermost pump drive shaft support bearing
101
for its lubrication. Again, the oil will drain through the return path as aforedescribed.
The invention has been described thus far in conjunction with opposed-type and in-line-type of high pressure fuel pumps. Another embodiment appears in
FIGS. 7 and 8
and provides a V-type high pressure fuel pump, indicated generally by the reference numeral
251
. This type of fuel pump may be easily incorporated in conjunction with a V-type engine, and one possible location is shown in phantom in FIG.
1
. In this location the pump can be disposed compactly to the engine
22
because of both units V shaped configuration as seen in FIG.
1
.
Again, be pump
251
basically has the same pumping plunger arrangements as those previously described and, for that reason, where components of this embodiment are the same or substantially similar to those previously described, will be identified by the same reference numerals, or the parts are not shown, because it is believed that those skilled in the art will readily understand the arrangement of the components. In this embodiment the pump
251
is designed for a four cylinder engine, but obviously this pump may be used with engines having any number of cylinders.
In this embodiment the pump
251
includes a cylinder block
252
that has a pair of aligned banks, each of which is adapted to receive a pumping assembly, indicated generally by the reference numerals
253
, which comprise the pumping plungers, delivery lines and actuators as previously described. One cylinder bank extends generally parallel to one of the engine cylinder banks
24
. The other pump cylinder bank is perpendicular to the first one.
These elements are mounted primarily in bores
254
formed at the lower portion of the pump receiving cavities, wherein the piston actuators, which are not shown, can operate with cam lobes
255
formed integrally on the cam shaft, which is indicated by the same reference numeral as previously applied, i.e.,
97
.
In this embodiment, the accumulator chamber
58
may be formed by a bore
256
that is formed integrally in the cylinder block
252
in the area between the bores
253
that receive the pumping mechanism. Internal cavities
257
perform the function of the supply conduits
57
from the previously described embodiments which supply the high pressure fluid to the accumulator chamber
256
. A pressure regulator may be contained within this assembly and hence, the high pressure regulated fuel return line
67
is connected directly to the fuel tank
48
for this return.
This embodiment employs a more compact lubricant pump, which can have the same construction as that of the embodiments of
FIGS. 5 and 6
, and which is, therefore, identified by the same reference numeral
207
. In all other regards, this embodiment is the same as those previously described.
A driving sprocket
258
is affixed to the upper end of the pump drive shaft
97
and is driven by a chain
259
or a flexible timing belt off of the crankshaft driving sprocket
112
, as shown in FIG.
1
.
In the embodiments of the invention as thus far described, the pumping plungers have all been actuated directly by cams on the pump drive shaft.
FIG. 9
shows another embodiment which employs a rocker arm actuation and hence, can achieve greater strokes for a given cam lift or strokes which can be varied if desired.
A pump constructed in accordance with this embodiment is identified generally by the reference numeral
301
and is shown only in a single cross-sectional view, because it is believed readily apparent to those skilled in the art, from the foregoing description, how the invention may be employed with varying numbers of plungers and varying orientations for them, such as in-line, V-type, etc., as previously described.
In this embodiment, the pump
301
includes an outer housing assembly
342
which defines a cavity
303
in which the pump drive shaft
304
is journaled for rotation in a manner as previously described. The pump drive shaft
304
has one or more cam lobes
305
that engage the follower portion
305
of a rocker arm, indicated generally by the reference numeral
307
. The rocker arm or rocker arms, if more than one are employed, are rotatably journaled on a rocker arm shaft
308
that extends parallel to the axis of rotation of the pump drive shaft
304
. As with all of the previously described embodiments, this pump drive shaft
304
rotates about an axis that is parallel to the axis of rotation of the crankshaft
27
and which, accordingly, is vertically disposed.
The rocker arm
307
has a further arm portion
309
that carries an adjustable follower
311
having a spherical portion
312
that is engaged with a yoke portion
313
of the pumping plunger, indicated generally by the reference numeral
314
. The pumping plunger
314
has a shank or plunger portion
315
which is supported in a pump support element
316
which is affixed in the housing
302
and which has an O-ring seal
317
that provides a seal therewith.
A valve body and distribution member
318
is affixed to the main pump housing
302
with an O-ring seal
319
encircling the plunger supporting member
316
and providing a seal therebetween. A pumping chamber
3211
formed in the member
318
and receives the pumping end of the pumping plunger
315
. A return spring
320
acts between the plunger support member
316
and the yoke portion
313
of the pumping plunger
315
to urge it into engagement with the adjustable follower
312
and to return it on its intake stroke.
Fuel is delivered to the pumping chamber
321
through an inlet fitting
322
which communicates with a delivery port
323
. The low pressure regulator
324
communicates with this area and, as aforenoted, regulates the pressure from the low pressure pump by returning fluid to the fuel tank
48
through the return conduit
66
.
A delivery check valve
325
permits fuel to flow into the pumping chamber
321
when the pumping plunger
311
is moving downwardly and precludes reverse flow as it moves upwardly. Upon upward movement, the fuel is compressed and discharged through a delivery check valve
326
to the accumulator chamber
58
through a supply passage
327
and a supply fitting
328
.
Like the previously described embodiments, the mechanism is also lubricated by a lubricant pump that is driven off the lower end of the pump drive shaft
304
in a manner as previously described. The lubrication system for the pumping plunger
315
appears in this figure and it includes the outer supply game
329
that communicates with an inner lubricating groove
331
through a plurality of drilled passages
332
, as with the previously described embodiments.
FIG. 10
shows another type of pump plunger actuating mechanism, and since this type of mechanism may be employed with any of the pump assemblies as previously described, only the plunger actuating mechanism will be described. Unlike the previously described cam and follower mechanisms, this mechanism employs a Geneva or segmented gear-type drive, indicated generally by the reference numeral
351
. A segmented gear having teeth segments
352
is affixed for rotation with the pump driving shaft
353
. The teeth
352
are adapted to selectively engage follower ribs
354
formed on an extension
355
of the pump plunger, indicated generally by the reference numeral
356
to drive the plunger
356
sequentially. The pump plunger
356
has a shoulder portion
357
that is engaged by a spring
358
for urging the plunger to a retracted position in the pumping bore
359
formed by a cylinder head member
361
.
The opposite end of the spring
358
acts against a plunger retainer element
362
which, like the previously described embodiments, provides an arrangement for lubricating the pump plunger
356
. This member
362
has an O-ring seat
363
that engages the pump housing
364
for sealing therewith. A similar seal
365
is disposed between the end of the plunger supporting member
362
and the cylinder head
361
.
An oil supply game
366
receives oil from an oil pump driven off the lower end of the pump drive shaft
353
. This oil is then delivered to lubricate the plunger
356
through drilled passageways
367
and a lubricant supply groove
368
that extends around the pump plunger within the member
362
.
FIG. 11
shows another embodiment driven similar to the embodiment of FIG.
10
. In this embodiment, however, there are two Geneva gear mechanisms
401
and
402
that operate so that their teeth
403
and
404
are respectively out of phase with the ribbed members
354
on the pumping plunger. These Geneva gear mechanisms
401
and
402
are driven by a pump drive shaft (not shown) and rotate in the same direction and at the same speed, but at a different phase to each other as noted. Thus, this mechanism is capable of supplying more pumping strokes during a given cycle.
From the foregoing description, it should be readily apparent that the embodiments of the invention are extremely effective in providing a high pressure pump for a vertical engine that can have a compact construction and thus, may be conveniently placed-relative to the engine. In addition, the pump shaft rotates about a vertically extending axis to simplify the drive from the vertically extending output shaft to the engine. Lubricating systems are incorporated within the pump mechanism for its lubrication.
It should be readily apparent to those skilled in the art that the foregoing descriptions at don of preferred embodiments of the invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims.
Claims
- 1. A fuel injected internal combustion engine having an output shaft rotatable about a vertically extending output shaft axis and driven by the combustion within the engine, a high pressure piston pump driven by a rotatable pump driving shaft journaled for rotation about a vertically extending pump drive axis and extending parallel to said engine output shaft axis, pump drive means for driving said pump drive shaft from said engine output shaft, and a lubricant pump driven off one end of said pump drive shaft for pumping lubricant to the elements of said high pressure pump.
- 2. The fuel injected internal combustion engine of claim 1, wherein the engine is a reciprocating engine and the engine output shaft comprises a crankshaft.
- 3. The fuel injected internal combustion engine of claim 1, wherein the lubricant pump is driven off the lower end of the pump drive shaft.
- 4. The fuel injected internal combustion engine of claim 1, wherein the pump drive shaft drives at least two pumping plungers.
- 5. The fuel injected internal combustion engine of claim 4, wherein the pumping plungers are disposed at an angle to each other, but in the same vertical plane.
- 6. The fuel injected internal combustion engine of claim 5, wherein the pumping plungers are opposed to each other.
- 7. The fuel injected internal combustion engine of claim 4, wherein the pumping plungers are arrayed in a vertical plane.
- 8. The fuel injected internal combustion engine of claim 7, wherein each pumping plunger is driven by a separate cam lobe.
- 9. The fuel injected internal combustion engine of claim 3, wherein the pump drive shaft is supported by a pair of spaced apart bearings and wherein the lubricant pump delivers lubricant to the bearings.
- 10. The fuel injected internal combustion engine of claim 9, wherein the lubricant pump further delivers lubricant to the pumping plunger for the lubrication of the pumping plunger.
- 11. The fuel injected internal combustion engine of claim 10, wherein the lubricant from the pumping plunger and the bearings is returned by gravity to the lubricant pump.
- 12. The fuel injected internal combustion engine of claim 2, wherein the lubricant pump is driven from the engine output shaft by a flexible transmitter.
- 13. The fuel injected internal combustion engine of claim 12, wherein the flexible transmitter comprises a chain.
- 14. The fuel injected internal combustion engine of claim 1, wherein the engine comprises the power plant of a marine outboard drive.
- 15. The fuel injected internal combustion engine of claim 14, wherein the engine is a reciprocating engine and the engine output shaft comprises a crankshaft.
- 16. The fuel injected internal combustion engine of claim 14, wherein the lubricant pump is driven off the lower end of the pump drive shaft.
- 17. The fuel injected internal combustion engine of claim 14, wherein the pump drive shaft drives at least two pumping plungers.
- 18. The fuel injected internal combustion engine of claim 17, wherein the pumping plungers are disposed at an angle to each other, but in die same vertical plane.
- 19. The fuel injected internal combustion engine of claim 18, wherein the pumping plungers are opposed to each other.
- 20. The fuel injected internal combustion engine of claim 17, wherein the pumping plungers are arrayed in a vertical plane.
- 21. The fuel injected internal combustion engine of claim 20, wherein each pumping plunger is driven by a separate cam lobe.
- 22. The fuel injected internal combustion engine of claim 16, wherein the pump drive shaft is supported by a pair of spaced apart bearings and wherein the lubricant pump delivers lubricant to the bearings.
- 23. The fuel injected internal combustion engine of claim 22, wherein the lubricant pump further delivers lubricant to the pumping plunger for the lubrication of the pumping plunger.
- 24. The fuel injected internal combustion engine of claim 23, wherein the lubricant from the pumping plunger and the bearings is returned by gravity to the lubricant pump.
- 25. The fuel injected internal combustion engine of claim 15, wherein the lubricant pump is driven from the engine output shaft by a flexible transmitter.
- 26. The fuel injected internal combustion engine of claim 25, wherein the flexible transmitter comprises a chain.
- 27. The fuel injected internal combustion engine of claim 14, wherein the engine comprises a reciprocating engine and the engine output shaft comprises a crankshaft driven by a pair of pistons slidably supported in a cylinder block having opposed cylinder banks, each defining at least one bore receiving respective one of said pistons.
- 28. The fuel injected internal combustion engine of claim 27, wherein the high pressure pump is disposed in a valley between the cylinder banks.
- 29. The fuel injected internal combustion engine of claim 28, wherein the high pressure pump has at least two plungers driven by the pump driving shaft and which are disposed in opposed relationship to each other.
- 30. The fuel injected internal combustion engine of claim 27, wherein the high pressure pump is disposed adjacent one side of one of the cylinder banks of the engine.
- 31. The fuel injected internal combustion engine of claim 30, wherein the pump has a plurality of pumping plungers disposed in a vertically arranged plane and which lie at a complementary angle to the angle of the cylinder bank.
- 32. The fuel injected internal combustion engine of claim 27, wherein the high pressure pump has a pair of pumping plungers disposed at a V angle to each other and is disposed on one side of one of the cylinder banks.
- 33. The fuel injected internal combustion engine of claim 32, wherein one of the pumping plungers reciprocates along an axis that is generally parallel to the axis of the cylinder bore of the adjacent cylinder bank and the other of the pumping plungers reciprocates along an axis that is generally perpendicular to the axis of the first pumping plunger.
- 34. An outboard motor comprised of a power head consisting of an internal combustion engine and a surrounding protective cowling and a driveshaft housing and lower unit containing a propulsion device within said lower unit depending from said power head, said engine being mounted within said protective cowling so that its crankshaft rotates about a vertically-extending axis, said crankshaft being coupled to a drive shaft that depends into said driveshaft housing and lower unit for driving said propulsion device, said engine being formed with a plurality of combustion chambers, a plurality of fuel injectors for injecting fuel directly into respective of said combustion chambers, a high pressure fuel pump contained within said protective cowling and having a pumping element reciprocating along a horizontal axis for pressurizing fuel for delivery to said fuel injectors, and a mechanical transmission for driving said pumping element from said crankshaft for delivering, high pressure fuel to said fuel injector.
- 35. An outboard motor as set forth in claim 34 wherein the pumping element is operated by a rotating cam.
- 36. An outboard motor as set forth in claim 35 wherein the rotating cam rotates about a vertically extending axis that is parallel to the axis of rotation of the crankshaft.
- 37. An outboard motor as set forth in claim 36 wherein the rotating cam is positioned externally of the engine body.
- 38. An outboard motor as set forth in claim 37 wherein the rotating cam is fixed for rotation with a camshaft that is directly driven by the crankshaft through a flexible transmitter.
- 39. An outboard motor as set forth in claim 34 wherein the engine is a spark ignited engine.
- 40. An outboard motor as set forth in claim 39 wherein the fuel injectors, inject fuel directly into the combustion chambers.
Priority Claims (1)
Number |
Date |
Country |
Kind |
6-300350 |
Nov 1993 |
JP |
|
US Referenced Citations (13)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2 140 083 |
Nov 1984 |
GB |
Divisions (1)
|
Number |
Date |
Country |
Parent |
08/556065 |
Nov 1995 |
US |
Child |
09/195459 |
|
US |
Reissues (1)
|
Number |
Date |
Country |
Parent |
08/556065 |
Nov 1995 |
US |
Child |
09/195459 |
|
US |