Wartsila Diesel International Ltd Oy

Convion Oy

Erkko Fontell

David C Jay

Matti Noponen

An injection valve arrangement for injecting a pressure medium into a combustion chamber of an internal combustion engine comprises a valve body formed with a feed duct and an actuation chamber, and an elongated valve member fitted in the valve body and movable in the valve body between an open position and a closed position. The valve member is formed with an internal chamber which is in communication with the feed duct and is also formed with one or more nozzle orifices which provide fluid communication between the internal chamber and the combustion chamber when the valve member is in the open position. The valve member has a piston surface bounding the actuation chamber such that force acting on the valve member due to pressure in the actuation chamber urges the valve member toward its open position against the force of a spring. A control valve controls feeding of pressure medium to the actuation chamber, so that when the control valve is open, supply of pressure medium to the actuation chamber causes an increase in pressure in the actuation chamber.

Injection valve arrangement

A fuel injection valve for an internal combustion engine comprises a valve body structure including a nozzle part formed with a needle passage having at least one nozzle passage at one end, a primary control chamber spaced along the needle passage from the nozzle passage, and a secondary control chamber. The primary control cheer is connected in use to a duct for supplying fuel under pressure. The nozzle part of the valve body structure has a seating surface between the nozzle passage and the primary control chamber. A needle structure is fitted slidably in the needle passage with one end of the needle structure proximate the seating surface. The needle structure has a first control surface that is exposed to pressure of fluid in the primary control chamber, a second control surface at the end of the needle structure proximate the seating surface, and a third control surface exposed to pressure of fluid in the secondary control chamber. The three control surfaces are disposed so that force generated by fluid pressure acting on each of these surfaces has a component urging the needle structure away from the seating surface against the force of a needle return spring. A control valve has a first position in which it communicates pressure of fuel in fuel supply duct to the secondary control chamber and a second position in which it cuts off the pressure of fuel in the fuel supply duct from the secondary control chamber. When the control valve is in its first position, it is urged by the pressure of fuel in the fuel supply duct toward its second position against the force of a control valve return spring.

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Vaasa, Finland

Erkko Fontell