A fuel injection system for an internal combustion engine including a fuel injector which can be subjected to fuel at high pressure and is actuatable via a metering valve device by which the pressure in a pressure booster control chamber is controllable such that the pressure in a pressure booster pressure chamber, defined by a pressure booster piston, that can be filled with fuel from the high-pressure fuel source via a filling path in which a check valve is disposed and that is in communication with an injection valve member pressure chamber, is increased by the pressure booster piston such that an injection valve member opens for injecting fuel, whereupon fuel is positively displaced out of a damping chamber via a damping path, in which a damping throttle is disposed. To assure stable injection performance, the damping path is embodied such and connected in such a way to the filling path that the fuel positively displaced from the damping chamber via the damping throttle in an injection event reaches the filling path of the pressure booster pressure chamber via the damping path.

Fuel injection system

The invention relates to a fuel-injection valve, in particular a high-pressure injection valve for directly injecting fuel into a combustion chamber of a compressed-mixture, spark-ignition internal combustion engine. Said valve is characterised in that an outlet opening (23) is provided downstream of the valve seat (20), the downstream end of said opening having a slit-forming element (30) that to a great extent closes the outlet opening (23). A slit-type flow outlet (35), through which a fuel spray can be discharged in a fan-type jet, is formed between the slit-forming element (30) and a front face (34) of the valve seat body (16).

Fuel-injection valve

During a transitional operation of an engine in which an engine load is changed suddenly from a high load to a low load, a control operation for extending an opening period of a change-over valve which is adapted to switch a low-pressure accumulator and a high-pressure accumulator from one to the other during a fuel injection operation is carried out to increase a flow rate of a fuel supplied to the low-pressure accumulator and thereby reduce the pressure in the high-pressure accumulator, whereby a response delay of the fuel pressure in the high-pressure accumulator is minimized. During a transitional operation of the engine in which the engine is in an accelerated operation, the change-over valve is kept open until the fuel pressure in the low-pressure accumulator, which is connected to the portion of a fuel passage which is on the downstream side of the change-over valve adapted to switch the low-pressure accumulator and high-pressure accumulator from one to the other during a fuel injection operation, reaches an indicated level, and until a predetermined period of time elapses after the fuel injection finishing time, whereby the formation of a fuel pressure in the low-pressure accumulator is promoted to obtain injection condition suiting the operating condition of the engine.

Accumulator-type fuel injection system

In a high pressure fuel supply pump for transmitting rotation of a cam to a reciprocating plunger via a tappet and a retainer, a diametric force acting on the plunger is reduced. The pump includes the retainer disposed on the plunger and a return spring exerting an urging force on the retainer in a direction of the tappet. A clearance between a plunger leading end and a tappet bottom surface opposed thereto is set to be greater than a clearance between a retainer bottom surface and the tappet bottom surface opposed thereto, and a clearance between a retainer inside diameter section and a plunger peripheral surface section opposed thereto is set to be greater than a clearance between a retainer outside diameter section and a tappet inner wall opposed thereto.

High-pressure fuel supply pump

A mobile vehicle having a substantially hexagonally-shaped frame member that is movable between a collapsed position to enable the vehicle to enter a vessel opening or an area having constrained access points and a more stable expanded position. Drive apparatuses are attached to the frame member for driving the vehicle on a surface. The vehicle is also equipped with a tether line that is used to supply control power to the vehicle drives and to deploy and retrieve the vehicle. Various collapsible tool members are operably attached to the vehicle for performing various tasks within an enclosed environment.

Collapsible mobile vehicle

A fuel-injection device has a pump working chamber (7) which can be supplied and discharged by means of a fuel line (13) provided with a solenoid valve (23). The pump working chamber (7) is connected to a fuel-injection valve (33). Control of the fuel injection is achieved by means of the opening or closing of the solenoid valve (23) during the delivery stroke of the pump piston (5). The solenoid valve (23) is controlled by a control device (51). A needle stroke transducer (61) is disposed at the nozzle needle of the fuel-injection valve (33) which, after a limit value is exceeded, detects the stroke moment of the nozzle needle as a precise signal of the commencement and termination, and therefore the quantity, of the fuel injection, and transmits it to the control device (51) where this actual value is compared with a desired value from performance characteristics and, if necessary, results in a correction of the controlling of the solenoid valve (23).

Fuel-injection device for internal-combustion engines

a) L'invention concerne un dispositif d'injection de carburant pour moteurs a combustion interne, b) dispositif caracterise en ce que le detecteur (61) constitue sous la forme d'un capteur de la course de l'aiguille transmet a l'appareil de commande (51) le signal de l'ouverture ou de la fermeture de l'aiguille d'injection seulement apres qu'une valeur limite determinee a ete depassee ou sous-depassee a partir du debut du mouvement de l'aiguille d'injection dans le sens de l'ouverture et dans le sens de la fermeture. c) L'invention applique aux moteurs a combustion interne a injection.

Helmut Laufer

Papers

Fuel-injection device for internal-combustion engines

Dispositif d'injection de carburant pour moteurs à combustion interne.