Patent number: 8356583

Variable camshaft timing device with hydraulic lock in an intermediate position

Original Assignee: BorgWarner Inc.

Field of technology: Vehicles, Engines and Transportation

Patent granted on: Tue, 22 Jan 2013

Patent drawing

Abstract

A variable cam timing phaser for an internal combustion engine including a piloted valve in the rotor assembly, movable from a first position to a second position, and detent lines communicating with the advance chamber or the retard chamber are restricted and or blocked when the rotor assembly is in or near an intermediate phase angle position. When the piloted valve is in the first position, fluid is blocked from flowing through the piloted valve. When the piloted valve is in a second position, fluid is allowed to flow between the detent line from the advance chamber and the detent line from the retard chamber through the piloted valve and a common line, such that the rotor assembly is moved to and held in the intermediate phase angle position relative to the housing assembly.