Information
-
Patent Grant
-
6217480
-
Patent Number
6,217,480
-
Date Filed
Tuesday, October 21, 199726 years ago
-
Date Issued
Tuesday, April 17, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Marmor; Charles A
- Pang; Roger
Agents
- Knobbe, Martens, Olson & Bear LLP
-
CPC
-
US Classifications
Field of Search
US
- 477 107
- 477 110
- 477 111
- 477 113
- 123 198 F
- 123 481
- 123 333
- 123 335
-
International Classifications
-
Abstract
An engine control for an internal combustion engine is disclosed. The engine preferably includes at least two cylinders or combustion chambers. The engine control is arranged to run the engine in a first mode in which all cylinders are operating and a second mode in which at least one of the cylinders is disabled, such as by misfiring the ignition element corresponding thereto. The engine control is arranged to operate the engine in the second mode only when a predetermined condition, such as idle, is detected for a predetermined amount of time. The engine control is also arranged to prevent the operation of the engine in the second mode if an engine operating condition has changed states, even if the predetermined condition is detected.
Description
FIELD OF THE INVENTION
The present invention relates to an engine control. More particularly, the present invention is an engine control in which one or more cylinders of the engine are disabled during one or more operating conditions.
BACKGROUND OF THE INVENTION
It is well known to use an electronic engine control to control various aspects of an internal combustion engine. As one example, engine controls are often used to control the ignition circuit which fires an ignition element corresponding to each cylinder of the engine. In such an arrangement, the engine control may be used to adjust the timing of the firing of the ignition element and thus advance or retard the ignition based on an operating condition of the engine.
Along these same lines, the engine control may be used to entirely prevent the firing of the ignition element of one or more cylinders or to so substantially adjust the timing of the firing to misfire one or more cylinders under certain operating conditions. This prevention of firing or substantial misfiring is generally referred to as cylinder disabling, since combustion does not occur in the cylinder at all or occurs at a time which is ineffective in powering the engine.
It has been proposed to use the cylinder disabling feature when the engine is idling. When the engine is idling, the firing of some but not all of the cylinders has the advantage that engine temperature is reduced since combustion is not occurring in one or more of the cylinders. When fuel is not supplied to the disabled cylinder(s), the fuel consumption rate of the engine is also advantageously decreased.
A significant disadvantage to such a cylinder disabling strategy is that the operator of the engine has no control over whether the control unit operates the engine in a disabling mode. In general, the control is arranged to operate the disabling mode anytime an indicator of engine idling is provided. In some instances, however, this indication may be provided when in fact the operator of the engine desires a high engine power output.
It is an object of the present invention to provide an engine control which employs a cylinder disabling mode at certain engine idle conditions, but which is arranged to prevent operation of the cylinder disabling mode during certain other conditions.
SUMMARY OF THE INVENTION
The present invention is an engine control for an engine. Preferably, the engine is of the internal combustion type and includes at least two cylinders or combustion chambers.
The engine control includes means for disabling at least one of the cylinders. In the preferred embodiment, the means for disabling is not activated until a predetermined condition is detected for a predetermined time. Preferably, the means for disabling is not activated unless an idle condition of the engine is detected for a predetermined time.
In still a further embodiment of the engine, the engine is operable in first and second states and the means for disabling may also be activated even if the predetermined time has not passed if the state of the engine has not changed. Preferably, this first and second states comprise a drive state of the engine relative to a water propulsion device.
In an alternate embodiment, the engine is arranged to power a water propulsion device of an outboard motor propelling a watercraft and the means for disabling is not activated unless the speed of the watercraft is below a predetermined speed.
Advantageously, the engine control of the present invention is arranged to operate the engine in a cylinder disabling mode only upon the occurrence of certain conditions. Thus, the disabling mode is not activated when, for example, the engine is enters an idle mode only for a short period of time.
Further objects, features, and advantages of the present invention over the prior art will become apparent from the detailed description of the drawings which follows, when considered with the attached figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
schematically illustrates an engine powering an outboard motor and having a control in accordance with the present invention;
FIG. 2
is a cross-sectional view of a top portion of the motor and illustrated in
FIG. 1
exposing a portion of the engine positioned in a cowling thereof;
FIG. 3
schematically illustrates a portion of the intake and cooling systems for the engine illustrated in
FIG. 1
;
FIG. 4
graphically illustrates the output of a first transmission shift sensor of the engine control;
FIG. 5
graphically illustrates the output of a second transmission shift sensor of the engine control;
FIG. 6
schematically illustrates a control strategy for the control of the present invention; and
FIG. 7
schematically illustrates another control strategy for the control of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
FIGS. 1 and 2
illustrate an outboard motor
20
powered by an engine
22
controlled with an engine control in accordance with the present invention. The control of the present invention is described with an engine
22
utilized to power an outboard motor
20
since this is an application with which an engine controlled with the control has particular utility. As may be appreciated by one skilled in the art, the engine control may be used to control an engine used in a variety of other applications.
In general, and as described in more detail below, the engine control of the present invention is arranged to selectively disable one or more cylinders of the engine dependent on one or more operating conditions.
Referring to
FIGS. 1 and 2
, the outboard motor
20
has a powerhead which comprises the engine
22
positioned in a cowling
24
. A lower unit
26
extends below the powerhead. The outboard motor
20
is connected to the hull
28
of a watercraft
30
, preferably at a transom portion of the watercraft
30
. The motor
20
is connected to the watercraft
30
by a clamping bracket
32
. Preferably, the motor
20
is connected to the clamping bracket
32
in a manner which permits side-to-side movement about a vertically extending axis for permitting steering of the watercraft
30
with the motor, and in a manner which permits movement up and down about a horizontally extending axis for permitting trimming of the motor
30
. These mountings are well known to those skilled in the art.
The engine
22
includes a cylinder block
34
having a cylinder head
36
connected thereto and cooperating therewith to define four cylinders
38
, each cylinder including a combustion chamber portion
39
. As is known to those skilled in the art, the engine
22
may have a greater or lesser number of cylinders
38
than four.
In the present embodiment, a piston
40
is movably mounted in each cylinder
38
. Each piston
40
is connected to a crankshaft
42
which is journalled for rotation with respect to the remainder of the engine
22
via a connecting rod
44
. The crankshaft
42
is preferably positioned in a crankcase chamber defined by the block
34
opposite the cylinder head
36
and enclosed with a crankcase cover
43
.
The crankshaft
42
is generally vertically extending, and likewise the cylinders
38
are preferably arranged in in-line vertical fashion. As known to those skilled in the art, the engine
22
may be arranged in other orientations, such as a āVā arrangement. In addition, the engine
22
may be of the rotary type.
As illustrated in
FIG. 1
, the crankshaft
42
is preferably arranged to drive a drive shaft
46
which extends through the lower unit
26
of the motor
20
to drive a means for propelling water. In the embodiment illustrated, the drive shaft
46
extends to a forward-neutral-reverse transmission
50
. This transmission
50
may be of a variety of types. As illustrated, the transmission
50
includes a bevel gear
52
mounted on the end of the drive shaft
46
for selective engagement with forward and reverse bevel gears
54
,
56
mounted on a propeller drive shaft
58
. The propeller drive shaft
58
extends to the means for propelling water, which in the present invention is illustrated as a propeller
60
having at least one blade
62
.
A shift mechanism
61
is provided for permitting the operator of the watercraft
30
to shift the transmission
50
between forward, neutral and reverse positions. As illustrated, the mechanism
61
includes a shift lever
63
moveable between F, N and R positions corresponding to forward, neutral and reverse transmission positions, respectively. The shift lever
63
is connected via a shift cable
65
to a shift rod
67
extending through the lower unit
26
of the motor
20
to the transmission
50
. As illustrated, the shift rod
67
is arranged to rotate and move the forward and reverse bevel gears
54
,
56
into selective engagement with the bevel gear
52
on the drive shaft (or into a position in which neither gear
54
,
56
engages the bevel gear
52
in a neutral position).
Air is provided to each cylinder
38
for use in a fuel combustion process. Referring to
FIG. 2
, air is drawn through a vent
64
in the cowling
24
of the motor
20
. The air entering the cowling
24
is then drawn into an inlet
68
into an intake system
66
. In the embodiment illustrated, the air is routed through a passage extending across the top of the engine
22
to a surge tank
70
.
Air is drawn from the surge tank
70
through a throttle body
72
and delivered into a manifold
74
which includes individual runners
76
corresponding to each cylinder
38
. The rate of air flow to the cylinders
38
of the engine
22
is preferably governed by a throttle plate
80
movably mounted in a passage through the throttle body
72
. This plate
80
is preferably remotely movable by an operator of the watercraft
30
from a position in which the plate
80
generally obstructs the passage and other positions in which the throttle plate
80
generally does not obstruct the passage.
Each runner
76
has a passage
82
therethrough leading to an intake port of a cylinder
38
. As illustrated in
FIG. 1
, means are provided for controlling the timing of the flow of air into each cylinder
38
. Preferably, this means comprises an intake valve
84
having one end positioned in the intake port. The valve
84
is preferably actuated between one position in which is obstructs or closes the-port and a second position in which the port is opened by an intake camshaft
86
.
Preferably, the intake camshaft
86
is arranged to actuate the intake valve
84
corresponding to all of the cylinders
38
. Means are provided for driving the camshaft
86
, as well known in the art. For example, this means may comprises a chain or belt extending from the crankshaft
42
to the camshaft
86
whereby the crankshaft
42
drives the camshaft
86
.
Fuel is also supplied to the cylinder
38
for combustion therein. Preferably, the fuel is supplied through a suitable charge former, such as a fuel injector
88
. As illustrated, a fuel injector
88
is provided corresponding to each runner
76
and delivers fuel into the air passing through the passage
82
corresponding thereto.
Fuel is supplied to each fuel injector
88
by a fuel supply system which preferably includes means for delivering fuel from a supply to the injector
88
at high pressure. The fuel is preferably supplied to the injectors
88
through a fuel rail
90
extending generally vertically along the cylinder head
38
of the engine
22
.
Products of the combustion process are routed from each cylinder
38
through an exhaust port leading to an exhaust passage
92
. The exhaust passage
92
leading from each cylinder
38
preferably extends to a common exhaust passage
94
leading to a point external to the motor
20
.
Means are provided for controlling the flow of exhaust from each cylinder
38
to its respective exhaust passage
92
. Preferably, this means comprises an exhaust valve
96
having one end position in the exhaust port. The exhaust valve
96
is moveable between a first position in which it obstructs or closes the exhaust port and prevents the flow of exhaust therethrough, and a second open position in which exhaust is permitted to flow from the cylinder
38
to the exhaust passage
92
. Preferably, the valve
96
is actuated by an exhaust camshaft
98
. The camshaft
98
is preferably driven in like manner to the intake camshaft
86
.
The details of the remainder of the exhaust system are not provided herein as they form no part of the present invention, and are well known to those skilled in the art.
The engine
22
preferably includes a cooling system. As illustrated in
FIG. 3
, cooling water is preferably supplied by a pump
91
to a cooling jacket
93
surrounding at least a portion of each cylinder
38
. The coolant may be water in which the motor
20
is operating drawn through an inlet.
The coolant flows through the jacket
93
and, selectively, to a discharge. Preferably, a thermostat
95
controls the flow of coolant from the jacket
93
to the discharge. The thermostat
95
is arranged to stop the flow of coolant to allow the engine
22
to warm up, and to permit coolant to flow freely through the jacket
93
when the engine temperature is high, as is well known to those skilled in the art.
The engine
22
includes an engine control for controlling various engine functions. Preferably, the engine control is of the type which receives information from various sensors and utilizes the data from the sensor to control the engine functions. As illustrated in
FIG. 1
, a throttle position sensor
100
preferably provides data regarding the position of the throttle plate
80
to an ECU
102
of the engine control. An idle sensor or switch
104
is arranged to indicate to the ECU
102
when the throttle plate
80
is moved to an idle position, i.e., a position in which the plate
80
generally obstructs the passage, restricting the flow of air and slowing the engine speed.
An intake air pressure sensor
106
in communication with the intake system
74
provides air pressure data to the ECU
102
. A crankshaft angle sensor
108
is provided for monitoring the speed and angle of the crankshaft
42
, and a cylinder distinguishing sensor
110
is preferably provided for determining the position of the piston
40
of at least one of the cylinders
38
. As is known to those skilled in the art, by knowing the position of one of the pistons
40
and the angular position of the crankshaft
42
it is possible to determine the position of the piston of every cylinder
38
of the engine
22
.
A shift lever position sensor
112
is provided for sensing the position of the shift lever
63
in its F, N or R positions and sending the position data to the ECU
102
. This type of sensor
112
is preferably arranged to provide a unique signal indicative of each of the three shifter positions, as best illustrated in FIG.
5
. In the alternative, a shift position sensor
112
a
may be provided for determining the rotational position of the shift rod
67
for providing shift position data to the ECU
102
. As may be understood, the shift rod
67
does not have such distinct positions corresponding to the shift positions as does the shift lever
63
. As such, this sensor
112
a
generally provides a signal such as that illustrated in
FIG. 4
, wherein the rotational position of the rod with respect to the sensor
112
a
results in a linear signal output.
A watercraft speed sensor
114
provides data to the ECU
102
regarding the speed of the watercraft
30
. An engine coolant temperature sensor
115
provides temperature data to the ECU
102
. Preferably, as illustrated in
FIG. 3
, the sensor
115
is in communication with the coolant in the cooling jacket
93
.
Based on the sensor data, the ECU
102
controls an ignition circuit
116
which triggers an ignition coil
118
for firing of a spark plug
120
corresponding to each cylinder
38
. In this manner, combustion within each cylinder
28
is controlled.
Preferably, the ECU
102
includes a cylinder disabling control. The ECU
102
is arranged to disable one or more, but not all, of the cylinders
38
when the engine
22
is in at least one mode, preferably an idle mode. This is accomplished by either not firing the spark plug
120
corresponding to one or more cylinders
38
, or by advancing or retarding the timing of the firing of the spark plug
120
to such an extent that the combustion does not occur at a time which serves to drive the piston
40
(i.e. misfiring). Preferably, when a particular cylinder
38
is disabled, the ECU
102
is arranged to stop the introduction of fuel to that cylinder
38
, such as by controlling the fuel injector
88
which provides fuel thereto.
Most importantly, however, and in accordance with the present invention, the engine control of the present invention is arranged to operate all cylinders
38
when an operating parameter indicates the need for all cylinders to operate, such as by the movement of a shift lever
63
.
A first control strategy is illustrated in FIG.
6
. As illustrated, in a first step S
1
, the ECU
102
checks the idle sensor or switch
104
to determine if the engine
22
is in idle mode. If not, in a step S
2
the ECU
102
determines if the time which has passed since the idle switch
104
was turned off is greater than a predetermined time. If not, this indicates the desire to increase engine speed from idle. As described above, the engine
22
of the present arrangement is preferably arranged so that the initial engine speed increase from idle is not accomplish by increasing the angle of the throttle plate
80
, but by increasing the number of cylinders which are operating. Thus in a step S
4
, the ECU
102
decreases the number of cylinders which are temporarily disabled to a point at which all cylinders
38
are operating. Thus, in the event the idle switch is off and has been off for a sufficient period of time, all cylinders
38
of the engine
22
will be operating, as illustrated in step S
3
.
In the event the idle switch
104
is turned on, in a step S
5
the ECU
102
checks to determine if the switch has been turned on for a greater or lesser amount of time than a predetermined amount of time. If the idle switch
104
has been turned on for more than a predetermined amount time, it is determined that the operator intends to idle the engine
22
and thus in a step S
6
the ECU
102
disables one or more cylinders.
If the idle switch
104
has been turned on less than a predetermined amount of time, in a step S
7
the ECU
102
checks to determine if the shift position sensor
112
/
112
a
has indicated a shift from neutral to reverse. If not, then it is presumed that the operator intends to idle the engine
22
and thus in the step S
6
the ECU
102
employs a cylinder disabling mode.
If so, then it is indicated that the operator wishes to drive the watercraft
24
with the motor
20
, and the ECU
102
employs, as indicated in step S
3
, a mode in which all cylinders are operated. In this manner, the engine
22
provides maximum power to the water propulsion device of the watercraft
30
for propelling it.
In summary, in accordance with the control strategy illustrated in
FIG. 6
, the engine control employs a cylinder disabling mode. This disabling mode, however, is activated only during certain engine idle conditions. In the event the engine
22
is placed in idle mode only temporarily. In the present invention, such is detected by determining whether the idle condition has existed for a less than a predetermined length of time or whether the operator has moved the shift lever
63
(such as from forward to neutral and then to reverse). In either event, the cylinder disabling mode is prevented since it is determined that it is not the desire of the operator to actually run the engine
22
at idle but to have the engine provide increased power.
This strategy permits the engine
22
to run in a disabling mode when idling to reduce fuel consumption and engine operating temperature. At the same time, all cylinders of the engine
22
are arranged to operate to propel the water propulsion device, preventing engine stalling and the like during acceleration of the watercraft
30
.
An alternate control arrangement is illustrated in FIG.
7
. The control strategy of this embodiment is similar to that illustrated in FIG.
6
. In this embodiment, step S
11
is provided in the alternative to step S
5
of the control strategy illustrated in FIG.
6
. In particular, instead of checking to see if the idle switch
104
has been turned on longer than a predetermined time to verify that an engine idle mode is desired as in step S
5
of
FIG. 6
, in step S
11
of
FIG. 7
the ECU
102
determines if the speed of the watercraft
30
is larger or higher than a predetermined speed. If the speed is lower than a predetermined speed, it is presumed that the idle condition is desired and the ECU
102
operates the engine
22
in a cylinder disabling mode (step S
16
). On the other hand, if the watercraft speed is higher than the predetermined speed and the shift lever
63
has been moved from a neutral to reverse position (step S
12
), then it is known that the operator desires the engine
22
to provide maximum propeller rotation in the reverse direction to slow the watercraft
30
, requiring maximum engine power and thus the operation of all cylinders (step S
15
).
Of course, the control strategy illustrated in
FIGS. 6 and 7
and described above could be arranged in the same manner with respect to a shift lever
63
movement from the neutral to the forward position. In other words, in steps S
7
and S
12
, the ECU
102
would determine in the shift lever
63
has moved from the neutral to the forward position instead of the neutral to reverse position. Also, the control may be arranged to determine if the shifter has been moved to either the forward or reverse positions from neutral in these steps, and if so, operating all cylinders of the engine.
Of course, the foregoing description is that of preferred embodiments of the invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims.
Claims
- 1. An engine control for an internal combustion engine having a plurality of cylinders and driving a load through a transmission having at least a load driving operating condition and a non-load driving operating condition, said engine being operable in an idle condition and a non-idle condition, said engine control including means for operating said engine in a first mode in which all cylinders are operating and a second mode in which at least one of said cylinders is disabled, said engine control arranged to operate said engine in said second mode both when said transmission non-load driving operating condition does not change to a said load driving operating condition and when said engine idle condition has existed for a more than a first predetermined amount of time and for returning the operation to said first mode both when said transmission is changed to said load driving operating condition and when said engine condition has been changed from said idle condition to said non-idle condition for more than a second predetermined amount of time.
- 2. The engine control in accordance with claim 1, wherein said load comprises a water propulsion device of a water vehicle in forward or reverse drive states or a neutral non-drive state.
Priority Claims (1)
Number |
Date |
Country |
Kind |
8-278093 |
Oct 1996 |
JP |
|
US Referenced Citations (27)