Liquid control valve assembly with local damping and hydraulically actuated fuel injector using same

摘要

A hydraulically actuated fuel injector comprises a valve body and a stepped valve member. The valve body has a wide bore portion and a narrow bore portion. The stepped valve member has a wide member section and a narrow member section. The wide member section is slidably disposed in the wide bore portion and defines a first diametrical clearance therebetween. The narrow member section and the wide bore portion define a damping chamber therebetween that is wider than the first diametrical clearance. The stepped valve member is slidable between a first position at which the damping chamber is substantially fluidly open to a low pressure hydraulic fluid reservoir, and a second position at which a fractional portion of the narrow member section is slidably disposed within a portion of the narrow bore portion defining a second diametrical clearance therebetween that is less wide than the damping chamber and substantially restricts fluid communication between the damping chamber and the reservoir.