Idling speed control system for outboard motor

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 from a neutral position to a forward position or a reverse position, having:

• secondary air supplier that supplies secondary air through 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;
• engine operating condition detecting means for detecting parameters indicative of operating conditions of the engine including at least an engine speed;
• engine start-state determining means for determining engine start-state as to whether the engine has been started based on one of the detected parameters;
• desired value determining means for determining a desired idling speed and for determining a desired secondary air supply amount such that a deviation 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 improvement comprises:
• clutch position detecting means for detecting the position of the clutch;
• wherein the desired value determining means determines the desired idling speed and the desired secondary air supply amount based on the determined engine start-state and the detected clutch position;
• and
• wherein the desired value determining means learning-controls the determined desired secondary air supply amount.

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 from a neutral position to a forward position or a reverse position, having:

• secondary air supplier that supplies secondary air through 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;
• engine operating condition detecting means for detecting parameters indicative of operating conditions of the engine including at least an engine speed;
• engine start-state determining means for determining engine start-state as to whether the engine has been started based on one of the detected parameters;
• desired value determining means for determining a desired idling speed and for determining a desired secondary air supply amount such that a deviation 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 improvement comprises:
• clutch position detecting means for detecting the position of the clutch;
• wherein the desired value determining means determines the desired idling speed and the desired secondary air supply amount based on the determined engine start-state and the detected clutch position;
• wherein the desired value determining means determines to correct the desired secondary air supply amount by a prescribed amount such that the deviation between the desired idling speed and the detected engine speed decreases, when the clutch position is changed;
• and
• wherein the desired value determining means determines to correct the desired secondary air supply amount by correcting a current command value which is determined based on a base current command value including a learning control value by the prescribed amount such that the deviation between the desired idling speed and the detected engines speed decreases.

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 from a neutral position to a forward position or a reverse position, and having secondary air supplier that supplies secondary air through 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;

• including the steps of:
• detecting parameters indicative of operating conditions of the engine including at least an engine speed;
• determining engine start-state as to whether the engine has been started based on one of the detected parameters;
• determining a desired idling speed and a desired secondary air supply amount such that a deviation between the determined desired idling speed and the detected engine speed decreases;
• and
• controlling the opening of the valve to a value that effects the desired secondary air supply amount;
• wherein the improvement comprises the steps of:
• detecting whether or not the clutch is at a neutral position by outputting either of two signals, one of said signals indicating that the clutch is in a neutral position and the other of said signals indicating that the clutch is in a forward or a reverse position, the same signal being output when the clutch is in a forward position and when the clutch is in a reverse position;
• and
• determining the desired idling speed and the desired secondary air supply amount based on the determined engine start-state and the detected clutch position.

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 from a neutral position to a forward position or a reverse position, and having secondary air supplier that supplies secondary air through 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;

• including the steps of:
• detecting parameters indicative of operating conditions of the engine including at least an engine speed;
• determining engine start-state as to whether the engine has been started based on one of the detected parameters;
• determining a desired idling speed and a desired secondary air supply amount such that a deviation between the determined desired idling speed and the detected engine speed decreases;
• and
• controlling the opening of the valve to a value that effects the desired secondary air supply amount;
• wherein the improvement comprises the steps of:
• detecting the position of the clutch;
• and
• determining the desired idling speed and the desired secondary air supply amount based on the determined engine start-state and the detected clutch position;
• and
• wherein the desired value determining step includes learning-controlling the determined desired secondary air supply amount.