Abstract:
The present invention controls the position of a center mounted spool valve (192) with an externally mounted vacuum controlled actuator (301). The actuator position is preferably controlled by a pulse width modulated or variable force solenoid (302), which modulates the amount of vacuum going to the actuator (301). A microprocessor (208) reads the phase angle and adjusts the duty cycle or current based on the error signal of the control loop (450). In a preferred embodiment, a position sensor (304) further controls the position of the spool valve (192). The position sensor (304) creates an inner loop (400) with position feedback on the position of the actuator (301) and spool valve (192), while the outer loop controls the phase angle. Added to the spool valve position is an offset to move the spool valve (192) to its steady state or null position (410).
Abstract:
A chain drive having a phaser such as a hydraulic vane phaser interposed between a timing chain and a driving or driven shaft is provided. The phaser or the vane are controlled to oscillate more at certain engine speeds to thereby reduce the tensioning force on the chain at the certain engine speeds.
Abstract:
A remotely mounted 4-way valve (2) or two solenoid valves (12) (13) control a center mounted spool valve (28). In the 4-way valve embodiment, one control port (3) provides oil pressure to one end (26) of the spool valve (28) and the other control port (4) provides oil pressure to the other end (27) of the spool (25). In the embodiment with two solenoid valves, one solenoid valve control port (16) feeds oil to one end (26) of the spool (25) and another solenoid valve control port (17) feeds oil to the other end (27). For both of these control systems, the relationship of percent of control signal to percent of control pressure is mapped into the controller, and varies as the engine oil pressure and temperature changes. In a preferred embodiment, a position sensor (34) mounted to the spool valve position reduces this error by having a control loop controlling the position of the spool valve. There is also another loop to control the phaser angle.
Abstract:
A lock mechanism for a phaser of a variable cam timing system is actuated by an electromagnetic force. Since the lock mechanism is not dependent upon engine oil pressure, it is actuatable at any time from engine startup to engine shutdown. A lock solenoid is preferably used to actuate a lock pin, which is otherwise urged toward a lock hole and a locked position by a spring force, to an unlocked position. The lock solenoid preferably acts on a pin lock plate that is coupled to the lock pin. A preferred startup method and a preferred shutdown method are also described.
Abstract:
A variable camshaft timing phaser for an internal combustion engine having at least one camshaft comprising a plurality of vanes in chambers defined by a housing and a spool valve. The vanes define an advance and a retard chamber. At least one of the vanes is cam torque actuated (CTA) and at least one of the other vanes is oil pressure actuated (OPA). The spool valve is coupled to the advance and retard chamber defined by the CTA vane and the advance chamber defined by the OPA vane. When the phaser is in the advance position, fluid is routed from the retard chamber defined by the OPA vane to the retard chamber defined the CTA vane. When the phaser is in the retard position, fluid is routed from the retard chamber defined by the CTA vane to the advance chamber defined by the CTA vane.
Abstract:
A variable camshaft timing phaser for an internal combustion engine having at least one camshaft comprising a plurality of vanes in chambers defined by a housing and a spool valve. The vanes define an advance and retard chamber. At least one of the vanes is cam torque actuated (CTA) and at least one of the other vanes is oil pressure actuated (OPA). The spool valve is coupled to the advance and retard chamber defined by the CTA vane and the advance chamber defined by the OPA vane. When the phaser is in the advance position, fluid is routed from the retard chamber defined by the OPA vane to the retard chamber defined the CTA vane. When the phaser is in the retard position fluid is routed from the retard chamber defined by the CTA vane to the advance chamber defined by the CTA vane.
Abstract:
A variable camshaft timing system for an internal combustion engine comprising a housing having an outer circumference for accepting drive force, a rotor for connection to a camshaft coaxially located within the housing capable of rotation to shift the relative angular position of the housing and the rotor, a locking pin, and a centrifugal valve. The locking pin is slidably located and radially moveable in a radial bore from a locked position in which the inner end fits into the recess defined by the housing, locking the relative angular position of the rotor and housing, to an unlocked position in which the inner end does not engage the receiving hole defined by the housing. The centrifugal valve is in fluid communication with an inlet line coupled directly to an engine oil supply controlling flow of oil to the locking pin.
Abstract:
A variable camshaft phase adjustment device (phaser) for an internal combustion engine having at least one camshaft. The phaser has a housing having an outer circumference for accepting a drive force, and a rotor connected to a camshaft coaxially located within the housing. The housing and the rotor are capable of rotation to shift the relative angular position of the camshaft and the crankshaft. The spool valve comprising a spool slidably mounted within a bore in the rotor. In the spool a chamber is present that has an input communicating with the bore the spool is mounted in, an output communicating with the outside, and an air flow restriction. Hydraulic fluid from the input communicating with the bore is prevented from communicating with the outside by the air flow restriction. The air flow restriction is either in the input communicating with the bore or the output communicating with the outside.
Abstract:
An internal combustion engine that has a camshaft having a plurality of cam lobes, a plurality of valves where each of the valves are actuated by a lifter actuated by the camshaft with a cam lobe. The lifter comprises a lifter body having an upper surface and a lower surface. A cam contact plate pivots on an axis on the upper surface of the lifter body. Opposed hydraulic actuators are present on either side of the axis of the cam contact plate, where each hydraulic actuators comprise a fluid chamber in the lifter body, a piston in the chamber, and a spring biasing the piston into contact with the cam contact plate. The lifter further comprises a line supplying hydraulic fluid to the fluid chambers of the hydraulic actuators and a control valve for controlling fluid flow from one hydraulic actuator to the other hydraulic actuator.
Abstract:
A phaser for an internal combustion engine having at least one camshaft. The phaser has a housing and a rotor. The housing has an outer circumference for accepting a drive force and the rotor connects to a camshaft coaxially located within the housing. The housing and the rotor define at least one vane separating chambers, advance and retard. The vane shifts the relative angular position of the housing and the rotor. The phaser also includes a spool valve comprising a spool slidably mounted within in a bore in the rotor. The spool routes operating fluid from a supply of pressurized fluid to the chambers. At least one passage from the supply to the chambers provides makeup fluid. The passage includes a check valve and a restrictor.