Avl Gesellschaft Fur Verbrennungskraftmaschinen Und Messtechnik M.b.h.

Avl List Gmbh

Herwig Ofner

Peter Herzog

Diethard Plohberger

Theodor Sams

Volker Pichl

Denis Walter Gill

The present invention relates to an injection system for an internal combustion engine operating on self-igniting, liquefied petroleum gas and including at least one injector per cylinder for direct fuel injection into the combustion chamber, a fuel tank in which fuel is held at a feed pressure, and a high-pressure fuel pump delivering fuel to the injector, the pressurized parts of the injector system being connected with the fuel tank by means of pressure relief lines. In order to ensure safe operation in a simple manner the proposal is put forward that a heating device should be provided which will convert the liquefied gas, at least partially, into a gaseous phase, at least in certain sections of the pressurized parts of the injection system. The gas bubble produced during this process will convey the liquid phase of the liquefied petroleum gas into the fuel tank.

Injection system

The present invention relates to an injection system for an internal combustion engine operated with liquefied petroleum gas and with a plurality of injection nozzles for the direct injection of fuel into the cylinders of the internal combustion engine, which injection system comprises the following:

Injection system for an internal combustion engine operated with

To provide an injection system for an internal combustion engine operating on self-igniting liquefied gas as a fuel, and to minimize cavitation and related problems of fuel delivery as well as wear, the fuel tank is configured as a low-pressure storage tank which is connected to a pressure control unit that includes a fuel pumping unit for drawing fuel from the storage tank and delivering the fuel to the suction line of the fuel delivery device and a pressure release line which branches off the suction line and leads back to the storage tank, the pressure release line including a release valve for maintaining a constant interior pressure in the suction line above the vapor pressure of the liquefied gas. The injection system is configured as a leakage-free system.

Injection system for an internal combustion engine

To provide an injection system for an internal combustion engine operating on self-igniting liquefied gas as a fuel, and to minimize cavitation and related problems of fuel delivery as well as wear, the fuel tank is configured as a low-pressure storage tank which is connected to a pressure control unit maintaining a constant interior pressure at a level above that of the vapor pressure of the liquefied gas, preferably at 6 to 30 bar, approximately, and further the injection system is configured as a leakage-free system.

In order to increase the safety of an injection system in an internal combustion engine operating on self-igniting liquefied gas as a fuel, especially after the engine has been switched off, the proposal is put forward that at least one pressurized part of the injection system be depressurized by means of a shut-down device, the latter including at least one pressure relief line which is controlled by at least one valve and opens into a tank with a low pressure level.

An injection system for an internal combustion engine, in particular an engine operating on liquid gas as fuel or fuel component, includes an injection unit for each cylinder for direct fuel injection into the combustion chamber, and a fuel supply system with at least one fuel tank and an oscillating pump element configured as a displacer for delivery of the fuel. The pump element is provided with an elastic sealing element fitted in a housing and which divides a pump chamber into two subchambers sealed tightly against each other, the first subchamber being supplied with fuel via a fuel feed line of the fuel supply system, and the second subchamber being supplied with a secondary medium. The dead volumes of the pump element may be reduced by configuring the pump chamber as an annular chamber at least partially surrounding a shaft moving axially in a cylinder, which shaft is mechanically linked with the sealing element.

In a device for controlling the lift of a hydraulically operated valve comprising an actuating element which is pressure-loaded or spring-loaded in closing direction and which acts as the boundary of an actuating chamber in the valve cage, and further comprising a pressure-generating unit, the valve lift is made continuously adjustable, independent of the control times of the valve, by providing that a flying setting plunger be used, which is guided in a cylinder, and which bounds a pressure from the actuating chamber in the valve cage, and by further providing that the pressure-generating unit have a high pressure line controlled by a valve and leading into the pressure chamber, as well as a low pressure line controlled by another valve and leading into the actuating chamber, the setting plunger being pressed against a stop in the cylinder during maximum valve lift.

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Stubing, Austria

Herwig Ofner