Patent ID: 7082923

Claim:
An idling speed control system for an internal combustion engine, comprising: an intake amount regulator valve that is arranged in or along an intake passage of the internal combustion engine to regulate an intake amount supplied to the internal combustion engine; a variable valve mechanism that changes at least one of an operation angle and a valve lift of an intake valve of the internal combustion engine; wherein the variable valve mechanism includes a valve control mechanism that changes the at least one of the operation angle and the valve lift of the intake valve seamlessly, and after the at least one of the operation angle and the valve lift of the intake valve has been changed via the variable valve mechanism in response to the change in the load generation state of the accessory device, the controller controls the variable valve mechanism to gradually change the at least one of the operation angle and the valve lift back to a level before being changed; a controller that controls the intake amount regulator valve and the variable valve mechanism; and an accessory device that is mechanically or electrically connected to the internal combustion engine and generates a load on the internal combustion engine during operation; wherein when a load generation state of the accessory device changes while the internal combustion engine is idling, the controller controls the intake amount regulator valve to change its opening and controls the variable valve mechanism to change the at least one of the operation angle and the valve lift of the intake valve in accordance with the change in the load generation state of the accessory device.