Abstract: A high-pressure pump includes a plunger that varies a volume of a pressurizing chamber, and a control valve that controls supply of fuel into the pressurizing chamber through a first valve body. When a predetermined execution condition is satisfied, an ECU reduces power supplied to a coil more than that in a normal control to implement a noise reduction control for reducing an operating noise generated along with the driving of the valve body. During the noise reduction control, a responsiveness parameter indicating responsiveness from starting energization of the coil until the valve body is displaced to a valve closing position is acquired. An energization start timing in the noise reduction control is calculated based on the acquired responsiveness parameter after the parameter is acquired. As a result, a discharge amount control of the high-pressure pump can be appropriately implemented in the noise reduction control.

Abstract: A control device for a high-pressure pump includes: a determination unit, an acquisition unit, and an electric power setting unit. The determination unit determines whether a movable portion of an electromagnetic valve has been moved to a closed position to close the electromagnetic valve when the electromagnetic valve is energized. The acquisition unit acquires, as an electromagnetic-valve response time, a period of time from a start of the energization of the electromagnetic valve until when it is determined that the electromagnetic valve has been closed. The electric power setting unit sets a supply power to the electromagnetic valve by repeating a process in which the supply power to the electromagnetic valve is reduced so as to be smaller than a previous value until the electromagnetic-valve response time reaches a predefined upper limit value.

Abstract: A control device for a high-pressure pump includes: a determination unit, an acquisition unit, and an electric power setting unit. The determination unit determines whether a movable portion of an electromagnetic valve has been moved to a closed position to close the electromagnetic valve when the electromagnetic valve is energized. The acquisition unit acquires, as an electromagnetic-valve response time, a period of time from a start of the energization of the electromagnetic valve until when it is determined that the electromagnetic valve has been closed. The electric power setting unit sets a supply power to the electromagnetic valve by repeating a process in which the supply power to the electromagnetic valve is reduced so as to be smaller than a previous value until the electromagnetic-valve response time reaches a predefined upper limit value.

Abstract: A high-pressure pump includes a plunger that varies a volume of a pressurizing chamber, and a control valve that controls supply of fuel into the pressurizing chamber through a first valve body. When a predetermined execution condition is satisfied, an ECU reduces power supplied to a coil more than that in a normal control to implement a noise reduction control for reducing an operating noise generated along with the driving of the valve body. During the noise reduction control, a responsiveness parameter indicating responsiveness from starting energization of the coil until the valve body is displaced to a valve closing position is acquired. An energization start timing in the noise reduction control is calculated based on the acquired responsiveness parameter after the parameter is acquired. As a result, a discharge amount control of the high-pressure pump can be appropriately implemented in the noise reduction control.

Abstract: A high-pressure pump includes a plunger and a control valve. An ECU adjusts a fuel discharge amount of the high-pressure pump by switching a valve opening and a valve closing of the control valve by the energization control of a coil. The ECU detects movement of the valve body with respect to a drive command of the valve opening or the valve closing of the control valve and executes an actuation determination of the high-pressure pump on the basis of a detection result. The ECU executes sound reduction control that reduces actuation sound of the high-pressure pump by controlling supply power supplied to the electromagnetic section on the basis of a determination result of the actuation determination in previous energization by the actuation determination section.

Abstract: In a system where an air-fuel ratio feedback correction amount is learned when its variation width is within a stable determination value, the stable determination value is set at larger value when a deviation amount of the correction amount becomes larger. When the air-fuel ratio feedback correction amount is rapidly changed after the learning is completed, the stable determination value is increased to moderate the learning condition and accelerate the learning speed (update speed of the learning value). Hence, the air-fuel ratio feedback correction amount is immediately learned. Furthermore, when a behavior of the air-fuel ratio feedback correction amount is stable, the stable determination value is made small to avoid an erroneous learning of the air-fuel ratio feedback correction amount.

Abstract: In a system where an air-fuel ratio feedback correction amount is learned when its variation width is within a stable determination value, the stable determination value is set at larger value when a deviation amount of the correction amount becomes larger When the air-fuel ratio feedback correction amount is rapidly changed after the learning is completed, the stable determination value is increased to moderate the learning condition and accelerate the learning speed (update speed of the learning value). Hence, the air-fuel ratio feedback correction amount is immediately learned. Furthermore, when a behavior of the airfuel ratio feedback correction amount is stable, the stable determination value is made small to avoid an erroneous learning of the air-fuel ratio feedback correction amount.

Abstract: When a specified air-fuel ratio F/B control condition is established during supply of a secondary air provided, an air-fuel ratio F/B control is executed, and at this time, an initial value of a target air-fuel ratio is set to a before-catalyst air-fuel ratio detected by an A/F (air-fuel ratio) sensor. The target air-fuel ratio subsequent to this is gradually changed from the initial value to a specified air-fuel ratio. By this, the initial value of the target air-fuel ratio can be suitably set at a start time of execution of the air-fuel ratio F/B control during the supply of the secondary air. The target air-fuel ratio subsequent to this is gradually changed to a stoichiometric air-fuel ratio, so that a change in engine rotation speed is suppressed and the drivability can be improved.

Abstract: When a specified air-fuel ratio F/B control condition is established during supply of a secondary air provided, an air-fuel ratio F/B control is executed, and at this time, an initial value of a target air-fuel ratio is set to a before-catalyst air-fuel ratio detected by an A/F (air-fuel ratio) sensor. The target air-fuel ratio subsequent to this is gradually changed from the initial value to a specified air-fuel ratio. By this, the initial value of the target air-fuel ratio can be suitably set at a start time of execution of the air-fuel ratio F/B control during the supply of the secondary air. The target air-fuel ratio subsequent to this is gradually changed to a stoichiometric air-fuel ratio, so that a change in engine rotation speed is suppressed and the drivability can be improved.