An object of the present invention is to provide a fuel injection valve which has a structure where failure hardly occurs in a valve member and a peripheral member thereof at the time of press-fitting of a fixed core. The present invention provides a fuel injection valve that includes: a valve member 114A; an anchor 102 which is relatively displaceable with respect to the valve member 114A; a fixed core 107 in which a through-hole 107A is formed; a gap forming member 133 which forms a gap between an engagement portion 129B on the valve member side and an engagement portion 102D on the anchor side; and a biasing spring 134 which biases the gap forming member 133 in a valve closing direction. The engagement portions 102D and 129B are provided in both the anchor 102 and the valve member 114A so as to be engaged with each other when the anchor 102 is displaced in a valve opening direction with respect to the valve member 114A, thereby regulating the displacement of the anchor 102 in the valve opening direction. An outer diameter of the gap forming member 133, an outer diameter of the biasing spring 134, and a maximum outer diameter of the valve member 114A are set to be smaller than an inner diameter of the through-hole 107A.

There is provided a vehicle engine control system that includes engine and transmission control functions and enables evacuation driving to be readily performed. A monitoring control circuit unit and an error processing circuit unit monitors controlling operation of a main control circuit unit; when the occurrence frequency of valve-opening control abnormality becomes larger than threshold value, a first storage circuit stores the occurrence frequency, and driving of an intake valve control motor is stopped to set to fixed opening degree; when transmission-control abnormality is occurs, power supply to automatic transmission is stopped to set to the third speed fixation ratio; when an abnormality occurs, evacuation driving is implemented using fixed opening degree and automatic transmission ratio, variable rotation speed and fixed transmission ratio, or fixed opening degree and fixed transmission ratio. When valve-opening control abnormality or transmission-control abnormality occurs, fuel injection control is prevented from being inappropriately stopped.

A system for controlling actuation of an electromagnetic actuator includes an actuator having an electrical coil, a magnetic core, and an armature. A controllable drive circuit is responsive to an electric power flow signal for driving current through the electrical coil to actuate the armature. A control module includes an armature motion observer configured to determine an armature motion parameter in the actuator based upon a magnetic flux within the actuator and a predetermined mechanical equation of motion corresponding to the actuator and adapt the electric power flow signal based on the armature motion parameter.

A solenoid actuator for an injection valve or an intake valve is driven with current control during closed-loop control phases. In between the closed-loop current control, the actuator must be clamped to an opposite voltage so as to quickly decrease the current through the solenoid. The current is measured immediately following the clamping phase so as to determine whether or not the clamping phase resulted in the correct current level. If the measured current indicates an extraneous reduction in the current, the clamping phase duration is shortened for the next activation of this clamping phase. If the measured current indicates an insufficient decrease, the clamping phase duration is lengthened for the next following activation cycle.

When a rotational speed of an engine is higher than a predetermined rotational speed, a low-pressure fuel injection valve is controlled through the use of a fuel injection time based on an estimated fuel pressure in a low pressure supply pipe and a target fuel injection amount. When the rotational speed of the engine is equal to or lower than the predetermined rotational speed, the low-pressure fuel injection valve is controlled through the use of a fuel injection time based on a detected fuel pressure input from the fuel pressure sensor from the issuance of a command to activate energization of a solenoid to the start of energization of the solenoid and a target fuel injection amount.

An object of the present invention is to provide a fuel injector which can promote convergence of a motion of a valve body while a valve is opened and promote stabilization of an injection amount. In the present invention, a fuel injector includes a movable iron core 404, a fixed iron core 401, a first spring member 405, a second spring member 406, contact portions 102c and 404b′, and a gap g1. The movable iron core 404 is provided relatively displaceable to a valve body 102. The fixed iron core 401 is opposed to the movable iron core 404. The first spring member 405 energizes the valve body 102 in a valve closing direction. The second spring member 406 energizes the movable iron core 404 in a valve closing direction. The contact portions 102c and 404b′ are in contact with each other in a case where the movable iron core 404 displaces in a valve opening direction with respect to the valve body 102. The gap g1 is formed between the contact portions 102c and 404b′ in a valve closing state. In a state in which the movable iron core 404 and the valve body 102 move in different directions after the movable iron core 404 collides with the fixed iron core 401 while a valve is opened, a spring force is not applied between the movable iron core 404 and the valve body 102.

An apparatus and method for operating a fuel injector of an internal combustion engine is disclosed. A first energizing electrical current is supplied to an injector solenoid, causing the opening of an injector control volume and a pressure reduction in said injector control volume, for a first energizing time. The first energizing time is predetermined to avoid that the pressure in the injector control volume approximates a value which would cause an injector needle to raise up and a fuel injection to start. After the predetermined time interval, a second energizing electrical current is supplied to the injector solenoid for a predetermined second energizing time, which is a function of a rail pressure (p.sub.rail) and a fuel injection quantity.

Disclosed is a method for controlling a fuel injector provided with a solenoid for actuating a needle which opens the injector and with a spring for returning the needle to the closed position. The solenoid is supplied with power by a controller including a first potential and a second potential, a first diode and a second diode, a first transistor, a second and a third transistor which is controlled so as to generate various currents using the potentials.

An engine includes a fuel injector. The fuel injector includes a valve body and an electromagnetic part that moves by energizing the valve body from a valve-closed position to a valve-open position. The fuel injector injects fuel when the valve body is moved to the valve-open position. In fuel injection, an ECU feeds a pre-charge current smaller than a current for operating the valve body, to the electromagnetic part in a pre-charge period at the beginning of a start of energization, and subsequently feeds a drive current for operating the valve body, to the electromagnetic part. Further, the ECU acquires a current change parameter as a parameter correlated with a speed of a rising change in drive current, and controls the feed of the pre-charge current to the electromagnetic part of the fuel injector, based on the acquired current change parameter.

An ECU calculates peak-current arrival time (time elapsed before a detected current arrives at a target peak current), and calculates predetermined-current arrival difference time (time elapsed before the detected current becomes lower than a predetermined current after exceeding the predetermined current). The ECU uses a beforehand stored relationship between the predetermined-current arrival difference time and defined peak-current arrival time to calculate the defined peak-current arrival time corresponding to the latest predetermined-current arrival difference time. The ECU uses such defined peak-current arrival time to compare the latest peak-current arrival time with the defined peak-current arrival time (for example, calculates a difference between the peak-current arrival time and the defined peak-current arrival time), and thus determines a shift in detected current of a current detection circuit.