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

A damped liquid valve assembly, comprising:

• a valve body having a bore;
• a valve member slidably disposed in the bore between a first position and a second position;
• and
• damping means comprised by the bore and the valve member for damping motion of the valve member toward the second position by forming a damping volume between the bore and the valve member, the damping volume becoming smaller as the valve member approaches the second position and having a restricted fluid access therefrom.

A hydraulically actuated fuel injector, comprising:

• a valve body defining a seat and a stepped guide bore, the stepped guide bore including a wide bore portion and a narrow bore portion;
• an actuator assembly positioned in the valve body and movable between a first position and a second position with respect to the valve body;
• and
• a stepped valve member attached with the actuator assembly, the stepped valve member including a poppet seating surface for engaging the seat, a wide member section, and a narrow member section, the wide member section being slidably disposed in the wide bore portion and defining a first diametrical clearance therebetween,
• the narrow member section and the wide bore portion defining a damping chamber therebetween that is wider than the first diametrical clearance,
• the stepped valve member being slidable between an undamped position at which the damping chamber is substantially fluidly open to a low pressure hydraulic fluid reservoir, and first and second damped positions 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.