Methods and systems are provided for detection of a closing time for a solenoid valve. In one example, a method may include monitoring a current of the solenoid valve, filtering the current, and determining the closing time of the solenoid valve based on each of the current and the filtered current. In some examples, the solenoid valve may be an electrically-actuated fuel injection valve. In some examples, determining the closing time may include using the filtered current to determine an inflection point of the current.

A valve seat member shared by an outlet valve and a pressure relief valve is provided between a pressurizing chamber and a high pressure path. A valve seat of the relief valve is provided on the side of the pressurizing chamber of the valve seat member. A valve seat of the outlet valve is provided in the valve seat member on the side of the high pressure path. One end of a relief path whose other end is open in the valve seat of the pressure relief valve is connected with the high pressure path, and one end of an outlet path whose other end is open in the valve seat of the outlet valve is connected with the pressurizing chamber.

A method is provided for determining the fuel temperature in the high-pressure zone of a fuel injection system of a motor vehicle. The fuel injection system has at least one injector operated by a servo valve which is actuated by means of a piezo actuator. After an injection process has been carried out, the piezo actuator is discharged after the injection has ended in such a way that the servo valve can close, but a non-positive connection remains between the piezo actuator and the servo valve. This condition of reduced charge is maintained. The pressure oscillation of the actuator voltage resulting from this is recorded and from this the hydraulic natural frequency of the enclosed high-pressure volume of fuel is deduced. The prevailing fuel temperature can be determined from the natural frequency.

A high-pressure fuel pump includes an outlet valve, a valve ball, a valve spring that acts on the valve ball in a closing direction, and a stop body for the valve ball. The stop body has a stop section that limits the opening stroke of the valve ball, and the valve spring is supported by the stop body. The stop body has a cut-out section that at least partially accommodates the valve spring and that has a radial inner periphery which forms a guide for the valve spring.

A fuel system includes a fuel injector having a split check assembly with a control piece, an outlet piece, and a check sleeve. A trapped volume is formed between the control piece and the outlet piece within the check sleeve, to hydraulically couple the control piece to the outlet piece. A starting rate shape clearance fluidly connects the trapped volume to a fuel cavity and is formed between the check sleeve and one of the control piece or outlet piece received therein, and modulates a starting rate shape of fuel injection from the fuel injector. Related methodology is disclosed.

A fuel injector nozzle assembly includes a two-piece outlet check having a timing control piece and a rate control piece. A nozzle passage is formed between a nozzle body and a two-piece outlet check, and a sac cavity is formed by the rate control piece and the nozzle body and fluidly connects a through-hole in the rate control piece to nozzle outlets. A starting-flow clearance is formed by the rate control piece and the timing control piece, and is opened by moving the timing control piece relative to the rate control piece. Moving the rate control piece relative to the nozzle body opens a main-flow seat. The nozzle assembly provides a slow starting injection rate shape in a common rail or similar fuel system and improved controllability over minimum delivery quantities.

A valve for metering a flowing medium, in particular a fluid, having a metering opening situated in the fluid flow and surrounded by a valve seat, a valve needle that controls the metering opening and that has a closing head that works together with the valve seat to close and release the metering opening, a piezoelectric actuator that acts on the valve needle to release the metering opening, and an elastic resetting element that acts on the valve needle to close the metering opening. To minimize the required stroke of the piezoelectric actuator for a required stroke of the closing head of the valve needle, the point of action of the resetting element on the valve needle is situated on or close to the end of the valve needle that bears the closing head.

Fuel injector systems, methods, and assemblies can comprise an injector pushrod; a hold down clamp having an opening that can slidably receive the injector pushrod; a helper spring that can surround a first portion of the injector pushrod; a spacer that can surround a second portion of the injector pushrod and that can be positioned between the hold down clamp and a first end of the helper spring; and a retention seat that can retain a second end of the helper spring opposite the first end of the helper spring and that can surround a third portion of the injector pushrod.

A subassembly for a high pressure fuel injector control valve includes, a control valve member and a sleeve attached to a stem of the control valve member, the sleeve extending along at least a partial axial length of the stem of the control valve member, and wherein a clearance, provided between the sleeve and the control valve member, is in fluid communication with the control chamber such that during use, pressure compensation occurs, as the sleeve is caused to expand and seal against the control valve bore, thereby preventing leakage of fuel within the control valve assembly.

A high pressure pump includes a housing with a chamber formed inside and a flow control valve and a discharge check valve installed in the chamber; a piston installed to operate up and down in an assembly hall formed in the housing to compress fuel in the chamber to a high pressure; a cylinder forming a gap between an inner circumferential surface and the piston and guiding reciprocation of the piston; and a support member seated on a stepped surface of the housing to surround an outside of the cylinder and configured to elastically support the housing and the cylinder, thereby reducing friction while preventing fuel leakage between the piston and the cylinder.