A combustion system is applied to an engine. The combustion system includes an injection device that injects a fuel into a combustion chamber, a spark plug that ignites fuel in the combustion chamber, and a control device that controls the injection device and the spark plug. The control device includes a first control unit that executes predetermined first control. In the first control, control is performed such that, a total injection amount corresponding to all the fuel injected by the injection device in one combustion cycle of the engine is injected within a first period corresponding to a period from valve close timing which brings an intake valve into a closed state until a first half of a compression stroke of the engine ends.

In at least some implementations, a fuel metering valve, includes a bobbin defining a passage and having one or more voids in the surface of the bobbin that defines the passage, aa wire coil around the bobbin and an armature. The armature is received within the passage in the bobbin and movable relative to the bobbin from a first position to a second position when electricity is supplied to the wire coil.

There are provided a laminated piezoelectric element in which a stress applied to an interface between a cover layer and a stacked body is reduced, and an injection device and a fuel injection system provided with the laminated piezoelectric element. A laminated piezoelectric element includes a stacked body in which piezoelectric layers and internal electrode layers are alternately laminated; and a cover layer disposed so as to surround a side face of the stacked body, and the cover layer has a two-layer structure with an annular boundary when viewed in a section perpendicular to a stacking direction of the stacked body.

A valve assembly for an injection valve is disclosed. The valve assembly includes a valve body having a cavity with a fluid inlet portion and a fluid outlet portion, a valve needle, an armature which is able to slide on the valve needle, and a disc element positioned to limit axial displaceability of the armature relative to the valve needle. The disc element includes a plurality of passages extending in axial direction through a disc-shaped part of the disc element. The passages provide a first flow resistance for a fluid passing in a direction away from the fluid outlet passage and a second flow resistance in a direction towards the fluid outlet passage, wherein the second flow resistance is larger than the first flow resistance.

A fuel injection valve control device controlling a fuel injection valve that injects a fuel into a combustion chamber includes an operation-condition calculation portion that calculates a fuel injection condition of the fuel injection valve based on a crank angle detected by a crank angle sensor that detects the crank angle of an engine, a current-waveform setting portion that sets a current waveform of a current supplied to the fuel injection valve on the basis of the fuel injection condition calculated by the operation-condition calculation portion, and so on. The current-waveform setting portion sets the current waveform so as to set a temporal change of a pickup current of a needle provided in the fuel injection valve to be equal to or less than a predetermined reference value when a fuel injection start timing is equal to or more than 180 degrees BTDC. The current-waveform setting portion sets the current waveform so as to set a temporal change of the pickup current of the needle to be more than the predetermined reference value when the fuel injection start timing is smaller than 180 degrees BTDC.

A fuel injection valve control device controlling a fuel injection valve that injects a fuel into a combustion chamber includes an operation-condition calculation portion that calculates a fuel injection condition of the fuel injection valve based on a crank angle detected by a crank angle sensor that detects the crank angle of an engine, a current-waveform setting portion that sets a current waveform of a current supplied to the fuel injection valve on the basis of the fuel injection condition calculated by the operation-condition calculation portion, and so on. The current-waveform setting portion sets the current waveform so as to set a temporal change of a pickup current of a needle provided in the fuel injection valve to be equal to or less than a predetermined reference value when a fuel injection start timing is equal to or more than 180 degrees BTDC. The current-waveform setting portion sets the current waveform so as to set a temporal change of the pickup current of the needle to be more than the predetermined reference value when the fuel injection start timing is smaller than 180 degrees BTDC.

Provided is a prestroke adjustment method for a fuel injection valve capable of reducing variations in a prestroke amount regardless of the level of machining accuracy of a component. The prestroke adjustment method adjusts a prestroke amount D2 of a fuel injection valve 1 including a gap forming member 50 that forms a gap G2 defining a prestroke between a valve member 30 and engagement portions 33a and 423a of a movable core 42 by a second portion 52a abutting on the movable core 42 in a state where a first portion 51a is positioned at a reference position 33b of the valve member 30. In the prestroke adjustment method, a load L in the direction from the first portion 51a toward the reference position 33b of the valve member 30 is applied to the gap forming member 50 assembled to the valve member 30 to plastically deform the gap forming member 50, thereby shortening the relative length between the first portion 51a and the second portion 52a and setting the prestroke amount D2 to the target value T2.

Provided is a prestroke adjustment method for a fuel injection valve capable of reducing variations in a prestroke amount regardless of the level of machining accuracy of a component. The prestroke adjustment method adjusts a prestroke amount D2 of a fuel injection valve 1 including a gap forming member 50 that forms a gap G2 defining a prestroke between a valve member 30 and engagement portions 33a and 423a of a movable core 42 by a second portion 52a abutting on the movable core 42 in a state where a first portion 51a is positioned at a reference position 33b of the valve member 30. In the prestroke adjustment method, a load L in the direction from the first portion 51a toward the reference position 33b of the valve member 30 is applied to the gap forming member 50 assembled to the valve member 30 to plastically deform the gap forming member 50, thereby shortening the relative length between the first portion 51a and the second portion 52a and setting the prestroke amount D2 to the target value T2.

In a fuel injection device, a driving unit structure has a magnetic aperture, in which an inner diameter is gradually enlarged toward the mover side, provided in an inner peripheral surface of the magnetic core. It is possible to reduce magnetic delay time upon valve opening from the supply of the electric current to the coil to the rise of magnetic flux and magnetic delay time upon valve closing from the stoppage of the electric current to the coil to reduction of magnetic flux, by providing a magnetic aperture in the inner peripheral surface of the magnetic core. Thus it is possible to improve the dynamic responsiveness upon valve opening and valve closing.

A fuel injector is configured such that a non-magnetic member constituting a magnetic circuit is deformed by an axial force generated when the non-magnetic member is combined with a cover and a housing, thereby providing airtight contact. The fuel injector is a device that injects fuel into an engine by raising a needle. A magnetic field generated from a coil forms a magnetic circuit when the coil is magnetized, and the magnetic circuit raises the needle. The fuel injector includes a block ring disposed inside the coil, a cover disposed at an upper end of the block ring, and a housing disposed at a lower end of the block ring. The block ring is made of a non-magnetic material and configured to extend the magnetic circuit. When the cover and the housing are combined by being screwed together, the upper end and the lower end of the block ring are deformed to provide airtight contact with respect to the cover and the housing, respectively.