Idling speed control system for outboard motor
First Claim
1. A system for controlling an idling speed for an outboard motor mounted on a boat and equipped with an internal combustion engine whose output is connected to a propeller through a clutch such that the boat is propelled forward or reverse when the clutch is changed to a neutral position to a forward position or a reverse position, comprising:
- a secondary air supplier that supplies secondary air trough a passage that is connected to an air intake pipe downstream of a throttle valve and that is equipped with a secondary air control valve such that amount of secondary air is supplied to the air intake pipe in response to an opening of the secondary air control valve;
clutch position detecting means for detecting a position of the clutch;
engine operating condition detecting means for detecting parameters indicative of operating conditions of the engine including at least an engine speed;
desired value determining means for determining a desired idling speed based on the detected position of the clutch and for determining a desired secondary air supply amount such that a difference between the determined desired idling speed and the detected engine speed decreases; and
valve controlling means for controlling the opening of the valve to a value that effects the desired secondary air supply amount;
wherein the desired value determining means including;
comparing means for calculating a change of the desired secondary air supply amount and for comparing the change with a predetermined value when it is determined based on the detected position of the clutch that the clutch is changed;
change direction determining means for determining whether the change is in an increasing direction or in a decreasing direction; and
correcting means for correcting the desired secondary air supply amount by a predetermined correction amount in the determined direction, when the change is greater than the predetermined value.
1 Assignment
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Accused Products
Abstract
An idling speed control system for an outboard motor mounted on a boat and equipped with an internal combustion engine, whose output is connected to a propeller through a clutch, having secondary air supplier that supplies secondary air. In the system, a difference of preceding and present current command values each indicative of a desired secondary air supply amount is comparing with a predetermined value when the clutch is changed, and the current command value is increased or decreased by a predetermined correction amount when the difference is greater than the predetermined value. With this, it can surely improve the control stability and suppress the overshooting or undershooting of engine speed due to the load change when the clutch is changed, thereby enabling to eliminate or reducing the shock to be felt by the operator and improving the feeling of the operator.
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Citations
22 Claims
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1. A system for controlling an idling speed for an outboard motor mounted on a boat and equipped with an internal combustion engine whose output is connected to a propeller through a clutch such that the boat is propelled forward or reverse when the clutch is changed to a neutral position to a forward position or a reverse position, comprising:
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a secondary air supplier that supplies secondary air trough a passage that is connected to an air intake pipe downstream of a throttle valve and that is equipped with a secondary air control valve such that amount of secondary air is supplied to the air intake pipe in response to an opening of the secondary air control valve;
clutch position detecting means for detecting a position of the clutch;
engine operating condition detecting means for detecting parameters indicative of operating conditions of the engine including at least an engine speed;
desired value determining means for determining a desired idling speed based on the detected position of the clutch and for determining a desired secondary air supply amount such that a difference between the determined desired idling speed and the detected engine speed decreases; and
valve controlling means for controlling the opening of the valve to a value that effects the desired secondary air supply amount;
wherein the desired value determining means including;
comparing means for calculating a change of the desired secondary air supply amount and for comparing the change with a predetermined value when it is determined based on the detected position of the clutch that the clutch is changed;
change direction determining means for determining whether the change is in an increasing direction or in a decreasing direction; and
correcting means for correcting the desired secondary air supply amount by a predetermined correction amount in the determined direction, when the change is greater than the predetermined value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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12. A method of controlling an idling speed for an outboard motor mounted on a boat and equipped with an internal combustion engine whose output is connected to a propeller through a clutch such that the boat is propelled forward or reverse when the clutch is changed to a neutral position to a forward position or a reverse position, having a secondary air supplier that supplies secondary air trough a passage that is connected to an air intake pipe downstream of a throttle valve and that is equipped with a secondary air control valve such that amount of secondary air is supplied to the air intake pipe in response to an opening of the secondary air control valve, comprising the steps of
(a) detecting a position of the clutch; -
(b) detecting parameters indicative of operating conditions of the engine including at least an engine speed;
(c) determining a desired idling speed based on the detected position of the clutch and for determining a desired secondary air supply amount such that a difference between the determined desired idling speed and the detected engine speed decreases; and
(d) controlling the opening of the valve to a value that effects the desired secondary air supply amount;
wherein the step (c) including the steps of;
(e) calculating a change of the desired secondary air supply amount and comparing the change with a predetermined value when it is determined based on the detected position of the clutch that the clutch is changed;
(f) determining whether the change is in an increasing direction or in a decreasing direction; and
(g) correcting the desired secondary air supply amount by a predetermined correction amount in the determined direction, when the change is greater than the predetermined value.
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Specification