Engine braking system
AssigneeCaterpillar Inc.
InventorClifford E. Cotton, III
Life of this patent
Estimating the term…
Abstract
An engine braking system for a multi-cylinder engine includes a supply of low pressure fluid and an engine fluid sump. A plurality of valve actuators are each configured to be alternatively fluidly coupled to the supply of low pressure fluid and the engine fluid sump. Each valve actuator is operably coupled to at least one exhaust valve for a respective cylinder. The system also includes a braking control valve operably coupled to two of the valve actuators. The braking control valve is movable between a first position at which the two valve actuators are fluidly coupled to the engine fluid sump and blocked from the supply of low pressure fluid and a second position at which the two valve actuators are fluidly coupled to the supply of low pressure fluid and blocked from the engine fluid sump.
Claims20
An engine braking system for a multi-cylinder engine, comprising:
- a supply of low pressure fluid;
- an engine fluid sump;
- a plurality of valve actuators, each of the valve actuators being configured to be alternatively fluidly coupled to the supply of low pressure fluid and the engine fluid sump, each valve actuator being operably coupled to at least one exhaust valve of a respective cylinder;
- and
- a braking control valve operably coupled to two of the valve actuators, the braking control valve being movable between a first position at which the two valve actuators are fluidly coupled to the engine fluid sump and blocked from the supply of low pressure fluid and a second position at which the two valve actuators are fluidly coupled to the supply of low pressure fluid and blocked from the engine fluid sump.
An engine braking method for a multi-cylinder engine wherein compressed air from the compression stroke of a cylinder is used for engine braking and the compressed air is released through a cylinder exhaust valve near a piston top-dead-center position, the method comprising:
- supplying fluid from a supply of low pressure fluid to a braking control valve;
- and
- selectively controlling movement of the braking control valve between a first position at which two valve actuators are fluidly coupled to an engine fluid sump and blocked from the supply of low pressure fluid and a second position at which the two valve actuators are fluidly coupled to the supply of low pressure fluid and blocked from the engine fluid sump, each of the valve actuators operably coupled to an exhaust valve of a different cylinder.
An engine braking system for two cylinders of a multi-cylinder engine, comprising:
- a supply of low pressure fluid;
- an engine fluid sump;
- two valve actuators, each valve actuator operably coupled to a different one of the two cylinders, each of the valve actuators being configured to be alternatively fluidly coupled to the supply of low pressure fluid and the engine fluid sump;
- a braking control valve operably coupled to the two valve actuators, the braking control valve being movable between a first position at which the two valve actuators are fluidly coupled to the engine fluid sump and blocked from the supply of low pressure fluid and a second position at which the two valve actuators are fluidly coupled to the supply of low pressure fluid and blocked from the engine fluid sump;
- a check valve associated with each of the two valve actuators, each check valve being configured to prevent fluid flow from a respective valve actuator to the supply of low pressure fluid;
- and
- at least one exhaust valve operably coupled to each of the two valve actuators.
Dependencies are inferred from the claim text.