A fuel injection valve includes a nozzle needle that opens or closes an injection hole communicating with an internal combustion engine, and a high-pressure fuel is introduced into a control room to urge the nozzle needle to close the injection hole. An orifice body includes a discharge passage through which the fuel is discharged from the control room to a low pressure portion, and an orifice-body sheet surface that is flat and surrounds a downstream end part of the discharge passage. A valve body contacts with or separates from the orifice-body sheet surface to close or open the discharge passage. A chamfered part is provided on a corner part in which the orifice-body sheet surface intersects with the discharge passage.

A throttle device for controlling a fuel quantity to be supplied to a fuel injection nozzle includes a control chamber and a supply device for supplying fuel to the control chamber. The supply device includes an inlet throttle having a length selected such that a fuel flowing through the inlet throttle, when in operation, flows through the inlet throttle in a turbulent flow. An injection device including the throttle device is also provided.

A fuel injection device has a valve body, a drive portion, a nozzle needle, and a control valve body. The valve body defines a control chamber, a valve chamber and a low pressure communication passage. The nozzle needle is displaced due to a fuel pressure variation in the control chamber to open/close an injection port. When the control valve body sits on an upper seat surface, a low pressure communication passage is closed so that the valve chamber is fluidly disconnected from the low pressure chamber. The control valve body defines a gap restriction on the upper seat surface. A flow passage area of a sub orifice provided to the low pressure communication passage is smaller than a flow passage area of the gap restriction.

A fuel injector includes an injector body and a valve stack within the injector body that includes a valve seat plate. The valve seat plate includes a pressure control passage for controlling fuel injection, and a valve seat positioned fluidly between the pressure control passage and a low-pressure drain. The valve seat plate includes a pressure-limiting annular groove that extends circumferentially around the valve seat and axially inward from a side of the valve seat plate where the valve seat is located. The groove enables deformation in response to pressure differences across the valve seat plate in a manner that limits stress concentrations.

A fuel injection device is provided with a valve body, a nozzle needle, a movable plate, and a support spring. The valve body has a control chamber therein. The control chamber is defined by a defining wall which has a dividing wall portion. The dividing wall portion divides the control chamber into an accommodation chamber and a backpressure chamber. The accommodation chamber accommodates a movable plate and a support spring. A fuel pressure in the backpressure chamber is applied to the nozzle needle. The dividing wall portion has a restriction hole fluidly connecting the accommodation chamber and the backpressure chamber with each other, and a support surface supporting the support spring.

A fuel injector device for injecting fuel into a combustion chamber of an internal combustion engine is provided. Included in the fuel injector is a body having a chamber and a pilot valve assembly including a seat retainer configured to be detachably insertable into the chamber of the body. A pilot valve seat is disposed in the seat retainer and substantially enclosed by the seat retainer. A stator assembly is disposed in the seat retainer and at least partially enclosed by the seat retainer. The pilot valve seat and the stator assembly in the pilot valve assembly are replaceable as a single unit of the pilot valve assembly for the fuel injector.

A control valve arrangement includes a valve body with a filling chamber with a filling hole. A filling valve is arranged in the filling chamber for opening or closing a first fluid communication controlling filling of a first control chamber, the filling valve having a filling valve member with a moving valve seat, the filling valve member being normally biased open by a first spring. A control valve opens and closes a second fluid communication for controlling the emptying of the first control chamber, the control valve being normally biased closed by a second spring. A plug is arranged in the valve body for closing the filling chamber, the plug being provided with an opening which cooperates with the moving valve seat, the opening defining the first fluid communication between the filling chamber and the first control chamber.

The invention relates to a fluid conveyance system for a fluid, comprising a low-pressure conveyance system having a low-pressure pump (2) and a high-pressure conveyance system having a high-pressure pump (8), which are connected by means of a connecting line, wherein the fluid conveyance system has a pressure damper (19). According to the invention, a fluid conveyance system is provided, by means of which a pulsation of the fluid caused by flow-rate waves or pressure waves in the fluid is damped. This is achieved in that the pressure damper (19) is arranged in the lower-pressure conveyance system and is a hydraulic pressure damper (19). Said hydraulic damper (19) has a piston (21) arranged in a cylinder (20), which piston can be moved against the force of a compression spring (23) and the vapor pressure present in a compression-spring chamber (22) accommodating the compression spring.

A needle type fuel injector has a needle control chamber at a pressure subject to a control valve in a control valve chamber which in an opening phase is lifted from its seat to expose the control valve chamber, connecting passage, and needle control chamber to a low pressure drain and in a closing phase is urged against the seat to isolate the control valve chamber, connecting passage, and needle control chamber from the drain. The potential for cavitation at high fuel injection pressure is reduced by throttling the flow of fuel past the control valve seat when the control valve opens, thereby maintaining sufficient back pressure in the control valve chamber and upstream connecting passages.

The invention relates to a high pressure pump for a fuel injection system, in particular a common rail injection system, comprising a housing part (1) with a bore (2), in which a pump piston (3) is received such that it can be moved with a reciprocating movement, which pump piston (3) is supported via a tappet assembly (4) on a cam (5) or eccentric and delimits a pump working chamber (6) in the axial direction, which pump working chamber (6) can be filled with fuel via an upstroke valve (7) which is integrated into the high pressure pump. According to the invention, a feed bore (8) is configured in the housing part (1) in order to supply the upstroke valve (7) with fuel, which feed bore (8) is connected to a bore (11) of a further housing part (12), which bore (11) connects a pump interior chamber (9) and a tappet chamber (10).