In general, the subject matter described in this disclosure can be embodied in a fuel injector that includes an upper housing portion that defines an inlet passage adapted to receive fuel, and a lower housing portion that is attached to the upper housing portion and that defines an injector outlet adapted to dispense fuel. The fuel injector includes an electromagnetic coil assembly that is user removable while the upper housing portion remains attached to the lower housing portion. The fuel injector includes a movable pintle that is biased to a closed position that is adapted to prevent fuel from flowing through the injector outlet, and movable, responsive to magnetic force produced by energizing the electromagnetic coil assembly, to an open position that is adapted to permit fuel to flow through the injector outlet.

A movable core is movable relative to a needle main body of a needle. A stationary core is placed on an opposite side of the movable core, which is opposite from a valve seat. A spring is operable to urge the needle and the movable core toward the valve seat. A spring seat is shaped into a ring form and is placed on a radially outer side of the needle main body at the valve seat side of the movable core. The spring is placed between the movable core and the spring seat and is operable to urge the movable core toward the stationary core. A guide is placed on the valve seat side of the movable core in an inside of a housing. An outer wall of the spring seat is slidable relative to an inner wall of the guide to guide reciprocation of the needle.

In an electromagnetic fuel injection which is structured such that both end surfaces of an inner circumferential iron core portion and an outer circumferential iron core portion face a movable iron core, and a non-magnetic portion made of a metal material is provided between both end surfaces, an object of the present invention is to realize a structure of the electromagnetic fuel injector in which a surface of a target object is unlikely to be affected by a heat treatment with the surface facing the movable iron core. In an electromagnetic fuel injector 1 of the present invention which is structured such that both end surfaces of an inner circumferential iron core portion 401a and an outer circumferential iron core portion 401b face a movable iron core 402, and a non-magnetic portion 401d made of a metal material is provided between both end surfaces, in order to achieve this object, heat in a target member to be heat treated is generated by applying energy to a target member's surface which is different from a target member's surface that faces the movable iron core 402. More preferably, energy is applied to a surface different from a surface on a side that faces the movable iron core 402.

The purpose of the present invention is to provide a fuel injection valve control device with which variability in the injection amount with respect to drive pulse width can be kept to a satisfactory level in each of a plurality of fuel injection devices. The present invention provides a fuel injection valve control device for controlling a plurality of fuel injection devices each equipped with a valve body and a solenoid for opening the valve body, characterized in that the device is configured such that, a prescribed time after voltage has been applied to the solenoid, a holding current is applied, the prescribed time and the holding current being corrected for each of the fuel injection devices, on the basis of the operating characteristics of the fuel injection device.

Provided are an electromagnetic valve control unit and a fuel injection control device using the same that can precisely detect a change of an operating state of an electromagnetic valve, that is, a valve opening time or a valve closing time of the electromagnetic valve, precisely correct a drive voltage or a drive current applied to the electromagnetic valve, and appropriately control opening/closing of the electromagnetic valve, with a simple configuration. In an electromagnetic valve control unit for controlling opening/closing of an electromagnetic valve by a drive voltage and a drive current to be applied, the drive voltage and the drive current applied to the electromagnetic valve are corrected on the basis of a detection time of an inflection point from time series data of the drive voltage and the drive current when the electromagnetic valve is opened/closed.

Electromagnetic solenoid has movable core having end surface that is formed between inner circumferential surface and outer circumferential surface of movable core; and fixed core having end surface that is formed between inner circumferential surface and outer circumferential surface of fixed core and faces the end surface of movable core. Ring-shaped protruding portion is formed at least either one of the end surface of the movable core or the end surface of the fixed core. Protruding portion is provided at a position that is shifted to a radially inner circumferential side of the end surface. A length between apex and inner circumferential edge of protruding portion is shorter than a length between the apex and an outer circumferential edge of protruding portion.

An in-cylinder pressure detecting apparatus for detecting a pressure in a combustion chamber of an internal combustion engine is provided. The in-cylinder pressure detecting apparatus comprises a pressure detecting element mounted on a tip-portion of a fuel injection device which injects fuel into the combustion chamber, and an amplifying circuit unit having an amplifying circuit which amplifies a signal output from the pressure detecting element and outputs a pressure detection signal. An in-cylinder pressure detecting unit integrated fuel injection device is configured by integrating an in-cylinder pressure detecting unit with the fuel injection device. The in-cylinder pressure detecting unit includes the pressure detecting element, the amplifying circuit unit, and a connecting member connecting the pressure detecting element with the amplifying circuit unit. The in-cylinder pressure detecting unit integrated fuel injection device is mounted on the internal combustion engine.

The present disclosure relates to internal combustion engines. Various embodiments thereof may include a fuel injection valve for a combustion engine comprising: a valve body with a cavity; a valve needle movable in the cavity; an actuator assembly to actuate the valve needle. The actuator assembly includes an electro-magnetic coil, a pole piece positioned inside the cavity, and an armature element. The armature element moves within the cavity to move the valve needle in a predetermined direction. A fixing ring abutting the pole piece, fixed to the valve body by means of joining to a circumferential surface of the cavity.

It is important not to form the partial bump in the collision structural part, however the fixed core and the movable core are relatively inclined due to an accumulation of tolerances and therefore even if each collision structural part of the fixed core and the movable core in formed in a flat shape, the fixed core and the movable core are contacted with not the whole of the collision structural parts but a part of the collision structural parts at the moment of the collision. In a case in which the collision structural part is formed in a ring shape or an intermittent ring shape, the fixed core and the movable core are contacted with each other at outer peripheral parts. Thus, when the fixed core and the movable core are collided with each other, a high stress is applied to the outer peripheral parts contacted first. Accordingly, the shape of the outer peripheral parts of the collision structural parts is important, however since such a part, which is a tiny protruding shape, requires high processing accuracy, to reduce stress occurred during collision while keeping productivity is difficult. In the present invention, an R-shaped part and a flat part are provided in order from an outer peripheral side of a collision structural part. Further, the R-shaped part and the flat part are connected in a tangent manner.

A method for providing consistent actuator events for each of a plurality of consecutive actuator events of an electromagnetic actuator, includes applying a first bi-directional current waveform for a first actuator event and applying a second bi-directional current waveform for a second actuator event immediately subsequent to the first actuator event. The first bi-directional current waveform includes applying current in a first direction when the actuator is commanded to an actuated position and applying current in a reversed second direction when the actuator is commanded to a rest position. The second bi-directional current waveform includes applying current in the reversed second direction when the actuator is commanded to an actuated position and applying current in the first direction when the actuator is commanded to a rest position.