A check valve part includes: a valve seat hole into which hydraulic oil flows; a valve seat formed around the valve seat hole; a lateral hole formed to have an axis intersecting an axis of the valve seat hole; and a valve body provided so as to be separated from the valve seat or abutted against the valve seat. The valve timing adjustment device further includes a back pressure oil passage that communicates a space opposite to the valve seat with respect to the valve body with the lateral hole.

In a first state: a spool valve of a control valve is disposed such that a second spool oil passage is closer to a second side in a longitudinal direction than a first spool oil passage; and as the spool valve has traveled toward the second side against a biasing force of a biasing member, a first port communicates with a second port via the first spool oil passage, a first sleeve oil passage, and the second spool oil passage. In a second state: the spool valve is disposed such that the first spool oil passage is closer to the second side than the second spool oil passage; and as the spool valve has traveled toward a first side in the longitudinal direction, the first port communicates with the second port via the first spool oil passage, the first sleeve oil passage, and the second spool oil passage.

A variable cam timing phaser has a rotor assembly with a central hub defining an axial bore and an interface groove with a first seal land, a second seal land and a single undercut area. A width of the first seal land is greater than a width of the second seal land. The single undercut area is in fluid communication with an axial undercut passage connected to a radial undercut passage within the rotor assembly. A clamping interface is between the camshaft and the rotor assembly, such that a seal is present between first seal land and the first end of the camshaft, and the second seal land and the first end of the camshaft. Fluid from a supply, flows into the passage of the camshaft to the single undercut area, through the axial undercut passage, the radial undercut passage to a passage within the rotor assembly.

In a first state: a spool valve of a control valve is disposed such that a second spool oil passage is closer to a second side in a longitudinal direction than a first spool oil passage; and as the spool valve has traveled toward the second side against a biasing force of a biasing member, a first port communicates with a second port via the first spool oil passage, a first sleeve oil passage, and the second spool oil passage. In a second state: the spool valve is disposed such that the first spool oil passage is closer to the second side than the second spool oil passage; and as the spool valve has traveled toward a first side in the longitudinal direction, the first port communicates with the second port via the first spool oil passage, the first sleeve oil passage, and the second spool oil passage.

A control device for an internal combustion engine includes an internal combustion engine and a valve opening-closing timing control device. The valve opening-closing timing control device has a phase adjustment mechanism for setting a relative rotation phase of a driving-side rotator and a driven-side rotator. The phase adjustment mechanism overlaps a timing of opening an intake valve with a timing of opening an exhaust valve, by setting, in a predetermined period, the relative rotation phase such that the exhaust valve closes after a top dead center position has been reached, and a bypass passage is provided that connects an exhaust passage of one cylinder that is in an exhaust process to the exhaust passage of another cylinder that is in an intake process at the same time as the exhaust process.

Methods and systems are provided for adjusting engine cranking. In one example, a method for an engine cold start may include extending engine cranking at least based on one or more engine cold start conditions, where extending engine cranking may increase an engine oil pressure in a plurality of camshaft phaser cavities of a variable camshaft timing (VCT) phaser. In some examples, the method may further include, after engine cranking, enabling fueling. In this way, fuel efficiency considerations may be balanced with increases to the engine oil pressure such that components of the VCT phaser may be actuated and/or lubricated.

A rotor is provided for a camshaft phaser. The rotor includes a plurality of vanes, a locking pin aperture, a vent passage connected to an end of the locking pin aperture, and an axial face configured to connect with a camshaft. The axial face defines a timing protrusion that is aligned with the vent passage or the locking pin aperture, and configured to be received by the camshaft.

A valve opening and closing timing control device includes: a drive-side rotary body rotating synchronously with a crankshaft; a driven-side rotary body provided inside the drive-side rotary body coaxial with the drive-side rotary body and rotating integrally with a camshaft; advance and retard chambers formed between the drive-side and driven-side rotary bodies; a valve unit including a spool and controlling supply and discharge of fluid to and from the advance and retard chambers; a tubular valve case having an internal space extending along the rotation axis inside the driven-side rotary body and housing the valve unit; first and second drain flow paths through which the fluid is discharged from one and the other of the advance and retard chambers, respectively, through the spool. The first drain and second drain flow paths extend in directions intersecting each other at different positions in the rotation axis direction.

A lock pin for a VCT device that has a locked position, locking a housing assembly relative to a rotor assembly of the variable cam timing device, and an unlocked position. The lock pin has a body comprising a first diameter with a first area, a second diameter with a second area, and a chamber formed between the first area of the first diameter and the second area of the second diameter for receiving fluid, the first area being greater than the second area. When fluid is applied to the chamber through the variable cam timing phaser, a difference between first area and the second area defining the chamber creates a force imbalance, such that the oil pressure applied to the chamber of the body assists in maintaining the Sock pin in the locked position.

A control device for an internal combustion engine includes an internal combustion engine and a valve opening-closing timing control device. The valve opening-closing timing control device has a phase adjustment mechanism for setting a relative rotation phase of a driving-side rotator and a driven-side rotator. The phase adjustment mechanism overlaps a timing of opening an intake valve with a timing of opening an exhaust valve, by setting, in a predetermined period, the relative rotation phase such that the exhaust valve closes after a top dead center position has been reached, and a bypass passage is provided that connects an exhaust passage of one cylinder that is in an exhaust process to the exhaust passage of another cylinder that is in an intake process at the same time as the exhaust process.