Internal-combustion engines – Accessories – Covers – trays – vibrators – corrosion inhibitors – air filters
Reexamination Certificate
2000-02-24
2003-07-22
Yuen, Henry C. (Department: 3747)
Internal-combustion engines
Accessories
Covers, trays, vibrators, corrosion inhibitors, air filters
C123S478000, C123S630000
Reexamination Certificate
active
06595179
ABSTRACT:
PRIORITY INFORMATION
This application is based on and claims priority to Japanese Patent Application No. 11-046,618, filed Feb. 24, 1998, the entire contents of which is hereby expressly incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to an electrical system for an engine. More particularly, the present invention relates to an improved electrical system that comprises a control unit and a power supply circuit that is connected to the control unit through a time delay switch.
2. Description of Related Art
Recently, engine designers have been emphasizing decreasing emissions, improving fuel economy and, at the same time, maintaining if not improving power output. One way of obtaining at least some of these results involves electrically controlling any of a variety of engine operations. For instance, ignition timing can be altered to better reflect changing engine operating parameters. Moreover, certain characteristics of fuel injected engines can be optimized through an electrically controlled fuel injection system.
An engine control unit (ECU) typically forms a portion of such an electrical control of the engine. For instance, an outboard engine can comprise a number of sensors that sense engine running conditions, ambient conditions or other conditions of the outboard motor that could affect ultimate engine performance. The engine generally includes controllable engine actuators such as, for example, fuel injectors and spark plugs. Signals from the sensors are received by the ECU and the ECU controls the engine actuators in response to the sensed signals. In arrangements in which the engine actuators are the fuel injector and spark plug, for instance, an injection timing, a duration of injection and a firing timing can be controlled and manipulated by the ECU. Thus, the ECU often forms an integral component in an efficiently designed and operated engine. Malfunctions with the ECU, therefore, can impair engine operation.
With reference now to
FIG. 1
, an exemplary circuit diagram of a prior power supply system is illustrated. It is believed that at least some portions of the illustrated circuit have been used in earlier outboard motor designs. As illustrated, a first portion of the power supply system is located within the watercraft hull while a second portion of the power supply system is located within the outboard motor. The first portion and the second portion can be joined through suitable couplings.
A battery
20
can be provided in the hull of the associated watercraft. In addition, an ECU
22
can be mounted on an engine used in the outboard motor. In the illustrated arrangement, a set of engine actuators, that can include a fuel injector
24
, an ignition coil
26
and a fuel pump
28
, are connected to the ECU
22
. The illustrated power supply system
30
further includes a main switch
32
and a stop switch
34
that is linked with the main switch
32
. These switches can be disposed within the hull of the watercraft. A locking relay
36
can be disposed on the outboard motor and a wire harness
38
can extend between and couple a variety of components.
The negative pole of the illustrated battery
20
is grounded and the positive pole thereof is connected directly to the ECU
22
and to the actuators
24
,
26
,
28
via the relay
36
. Preferably, the relay
36
is normally open. The relay
36
generally comprises an excitable coil
44
that holds the contacts
40
in a closed position when supplied with electrical power. One end of the coil
44
can be grounded and the other end can be connected to a relay control terminal
46
of the ECU
22
. The positive pole of the battery
20
is also connected to a relay-state detection terminal
48
of the ECU
22
via the main switch
32
.
One end of the stop switch
34
can be grounded, while the other end thereof is connected to the ECU
22
. The stop switch
34
is normally closed and can be opened when the main switch
32
is closed because the switch
34
is linked to the main switch
32
.
When the main switch
32
is closed, the exciting coil
44
is powered through the ECU
22
and the contacts
40
of the relay
36
are closed. Simultaneously, the ECU
22
holds the contacts
40
in this/closed position through a supply of electricity. The engine actuators
24
,
26
,
28
are, therefore, supplied with power. When the main switch
32
is opened, the stop switch
34
is closed and the ECU
22
stops supplying power to the coil
44
. The ECU
22
continues operating for a preset time after the stop switch
34
is closed and then the ECU
22
shuts down.
Because the exciting coil
44
of the relay
36
is controlled by the ECU
22
in the illustrated power supply system
30
, the ECU
22
must furnish a separate control circuit for the relay use only. The provision of the seperate control circuit necessarily increases the size and associated cost of the ECU
22
. In addition, the ECU
22
is coupled with the sensors and engine actuators through a connector that has multiple terminals. Connectors sold on the market are available for this purpose. However, because such connectors have a fixed number of terminals, for example, twenty four or thirty two terminals, if even one or more terminals, is needed, a special connector must be used. This increases the cost of the ECU
22
and occasionally requires a larger connector size. In this regard, the conventional power supply system
30
needs at least two additional terminals. i.e., the relay control terminal
46
and the relay detective terminal
48
, for the activation and deactivation of the relay
36
.
SUMMARY OF THE INVENTION
A need therefore exists for an improved engine electrical control system that can decrease the required size and cost of the associated ECU.
Accordingly, one aspect of the present invention involve a control system for an internal combustion engine comprising a power source and a control unit controlling an operation of the engine. A coupling switch selectively joins the power source and the control unit. A main switch is provided between the power source and the coupling switch with the main switch being adapted to switch the coupling switch between a coupling condition and a non-coupling condition. The coupling switch is brought to the coupling condition when the main switch is closed. The coupling switch includes an actuator that is coupled to the power source through the main switch with the actuator being adapted to move and maintain the coupling switch in the coupling condition when activated. A delay component is coupled to the actuator with the delay component selectively activating the actuator after the main switch is opened.
Another aspect of the present invention involves a method of controlling a power supply to a controller adapted to control an engine. The method comprising sensing an operational condition of a main switch, generating an output signal when said operational condition of said main switch changes for a preset period of time, and delaying a shutdown of said controller when said output signal ends.
A further aspect of the present invention involves an electrical control system for an internal combustion engine comprising a control unit controlling an operation of the engine and a power source. Coupling means are provided for coupling together the control unit and the power source under a coupling condition. A switch is provided for switching the coupling means between the coupling condition and a non-coupling condition. The coupling means are brought to the coupling condition when the switch is turned on and the coupling means include a self-hold element that holds the coupling means under the coupling condition when activated by electric power supplied through the switch. The control system further comprises preservation means that are provided for preserving the self-hold element under an active condition when the switch is turned off.
For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and
Benton Jason
Knobbe Martens Olson & Bear LLP
Yamaha Marine Kabushiki Kaisha
Yuen Henry C.
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