Variable lost motion valve actuator and method

A engine valve actuation system adapted to selectively provide main valve event actuations and auxiliary valve event actuations, said system comprising:

• means for containing the system, said containing means having a piston bore and a first fluid passage communicating with the piston bore;
• a lever located adjacent to the containing means, said lever including (i) a first repositionable end, (ii) a second end for transmitting motion to an engine valve, and (iii) a centrally located cam roller;
• a piston disposed in the piston bore and connected to the first repositionable end of the lever;
• a cam in contact with the cam roller;
• a fluid control valve in communication with the piston bore via the first fluid passage;
• means for actuating the fluid control valve to control the flow of fluid from the piston bore through the first fluid passage;
• and
• means for supplying low pressure fluid to the piston bore.

An apparatus for limiting the seating velocity of an engine valve comprising:

• a housing;
• a seating bore provided in the housing;
• means for supplying fluid to the seating bore;
• an outer sleeve slidably disposed in the seating bore and defining an interior chamber;
• a cup piston slidably disposed in the outer sleeve, said cup piston having a lower surface adapted to transmit a valve seating force to the engine valve;
• a cap connected to an upper portion of the outer sleeve, said cap having an opening there through;
• a disk disposed within the interior chamber between the cup piston and the cap, said disk having at least one opening there through;
• a central pin disposed in the interior chamber between the cup piston and the disk;
• a spring disposed around the central pin and between the disk and the cup piston;
• an upper seating member slidably disposed in the seating bore;
• and
• a means for biasing the upper seating member towards the cap.

A valve actuation system for controlling the operation of an engine valve, said system comprising:

• means for hydraulically varying the amount of engine valve actuation;
• a solenoid actuated trigger valve operatively connected to the means for hydraulically varying;
• and
• means for determining trigger valve actuation and deactuation times based on a selected engine mode, and engine load and engine speed values.

A valve actuation system for controlling the operation of at least one valve of an engine at different operating temperatures, comprising:

• means for determining a present temperature of an engine fluid;
• means for operating the at least one valve;
• and
• means for modifying the operation of the at least one valve in response to the determined temperature.

A valve actuation system for controlling the operation of at least one valve of an engine at different engine fluid operating viscosities, comprising:

• means for determining a present viscosity of an engine fluid;
• means for operating the at least one valve;
• and
• means for modifying the operation of the at least one valve in response to the determined viscosity.

A method of modifying the timing of at least one engine valve, said method comprising the steps of:

• determining a current temperature of an engine fluid;
• determining a timing modification for the operation of the at least one engine valve based on the determined current temperature;
• and
• modifying the timing of the operation of the at least one engine valve in response to the determined timing modification.

A method of modifying the timing of at least one engine valve, said method comprising the steps of:

• determining a current viscosity of an engine fluid;
• determining a timing modification for the operation of the at least one engine valve based on the determined current viscosity;
• and
• modifying the timing of the operation of the at least one engine valve in response to the determined timing modification.

A valve actuation system for compensating for varying engine fluid viscosity by controlling the operation of at least one valve of an engine at different operating temperatures, said system comprising:

• measuring means for determining a present temperature of an engine fluid;
• measuring means for determining a present viscosity of an engine fluid;
• operating means for operating the at least one valve;
• and
• control means for modifying the operation of the at least one valve in response to the temperature determined by said temperature measuring means and the viscosity determined by said viscosity measuring means.

A lost motion engine valve actuation system comprising:

• a rocker lever adapted to provide engine valve actuation motion, said rocker lever having a first repositionable end and a second end for transmitting valve actuation motion;
• means for hydraulically varying the position of the first end of the rocker lever;
• and
• means for maintaining the position of the first end of the rocker lever during periods of time that the means for hydraulically varying is inoperative.