Rocker latch for controlling engine valve actuation
AssigneeJacobs Vehicle Systems, Inc.
InventorsG. Michael Gron, JR., Justin Damien Baltrucki, Neil Fuchs, John J. Lester
Life of this patent
Estimating the term…
Abstract
Engine valve actuation systems and methods used to decompress an engine cylinder during engine start-up, shut-down, and for bleeder braking are disclosed. An exemplary system may include a rocker arm pivotally mounted on a rocker shaft, and a structure mounted adjacent to the rocker arm in a fixed position relative to the rocker arm. A latch piston may be slidably disposed between the rocker arm and the structure. The latch piston may be selectively extended to engage both the rocker arm and structure to limit the pivotal motion of the rocker arm and maintain the engine valves in an open condition.
Claims23
A system for preventing a rocker arm actuated engine valve from closing, said system comprising:
- a rocker arm pivotally mounted on a rocker shaft;
- a structure mounted adjacent to the rocker arm in a fixed position relative to the rocker arm;
- a latch piston slidably disposed between the rocker arm and the structure, and
- a latch piston actuator operatively connected to the latch piston,
- wherein said latch piston is adapted to assume an extended position causing the latch piston to engage both the rocker arm and the structure to limit the pivotal motion of the rocker arm,
- wherein the latch piston actuator is adapted to exert a force on the latch piston to cause the latch piston to assume the extended position or to retract from the extended position, and
- wherein the latch piston further comprises an engagement surface adapted to maintain the latch piston in the extended position continuously when the latch piston actuator ceases to exert force on the latch piston.
A method of decompressing an internal combustion engine cylinder comprising the steps of:
- pivoting a rocker arm in a first direction to open an engine valve associated with the engine cylinder and the rocker arm;
- pivoting the rocker arm in a second direction so that the engine valve moves in a closing direction;
- exerting an actuation force on a latch piston to cause the latch piston to engage the rocker arm and a structure adjacent to the rocker arm, or to disengage the rocker arm from the structure;
- maintaining the engine valve in an open position in response to the latch piston engaging the rocker arm and the structure;
- and
- maintaining the latch piston in a position in which it engages the rocker arm and the structure after the actuation force on the latch piston is reduced so that the engine valve maintains an open position.
A method of starting an internal combustion engine, comprising the steps of:
- maintaining one or more engine valves in an engine cylinder in a continuously open state for more than one engine cycle during engine cranking;
- discontinuing maintaining the one or more engine valves in the continuously open state after an engine parameter has reached a predetermined value;
- and
- providing fuel to the engine cylinder for engine start-up responsive to the discontinuation of maintaining the one or more engine valves in the continuously open state.
Dependencies are inferred from the claim text.