Patent attributes
When an engine is cold-started, the engine oil is quite viscous and requires larger passageways to flow through the engine than when the engine is warmed up and the engine oil flows readily. The present invention relates to a pin valve assembly which may be used on a fuel injector of an engine. The pin valve assembly of the present invention includes a movable shuttle which allows for a relatively large fluid flow space within the pin valve assembly when the engine is cold, and then moves to reduce the fluid flow space when the engine oil is less viscous and requires less room to flow as desired. Therefore, the advantages of a relatively large fluid flow space as well as a shorter pin travel distance within the pin valve assembly are both preserved.