COMPRESSION RELEASE ENGINE BRAKES WITH ELECTRONICALLY CONTROLLED, MULTI-COIL HYDRAULIC VALVES

摘要

In a compression release engine brake for increasing the braking available from an associated internal combustion engine, an electrically controlled hydraulic valve (30) having at least two coils (54a, 54b) and at least two positions is used to apply high pressure hydraulic fluid to a hydraulic actuator (70) for opening an exhaust valve (82) in the engine when a compression release event in the engine is desired. After each compression release event, the valve (70) is switched to a condition in which it allows hydraulic fluid to drain from the hydraulic actuator, thereby allowing the associated engine exhaust valve (82) to close.