| 摘要 |
A variable valve timing control device has, as control modes for adjusting inflow and outflow of oil with an OCV, a lock mode for moving a lock pin in a locking direction, a phase control mode for controlling a camshaft phase by a target phase in accordance with an operation state of an engine, and an oil filling mode for filling an advancement chamber and a retardation chamber with the oil in a state that the lock pin moves in the locking direction, before shifting from the lock mode to the phase control mode. When the oil filling mode has been selected, a target position of a spool is set based on viscosity of the oil, and the position of the spool is controlled so as to be the set target position. |
| 主权项 |
1. A valve timing control device of an internal combustion engine, the device comprising:
a timing adjustment device that changes a rotation phase of a camshaft with respect to a crank shaft by adjustment of inflow and outflow of hydraulic oil to and from an advancement chamber and a retardation chamber, to adjust valve timing; a lock pin that moves by adjustment of inflow and outflow of the hydraulic oil to and from an oil pressure chamber, to lock the rotation phase in an intermediate phase between the most advanced phase and the most retarded phase; and an oil pressure adjustment valve that adjusts inflow and outflow of the hydraulic oil to and from the advancement chamber, the retardation chamber, and the oil pressure chamber by reciprocation of a spool in a shaft direction, wherein the lock pin moves in a lock releasing direction by inflow of the hydraulic oil to the oil pressure chamber, and moves in a locking direction by outflow of the hydraulic oil from the oil pressure chamber, a first region, a second region, and a third region are aligned in this order in the shaft direction of the spool as regions in which the spool moves, and the valve timing control device includes:
a mode selection device that selects as a control mode any of a lock mode for setting a target position of the spool within the first region to move the lock pin in the locking direction, a phase control mode for setting the target position within the third region to control the rotation phase by a target phase in accordance with an operation state of the internal combustion engine, and an oil filling mode for setting the target position within the second region before a shift is made from the lock mode to the phase control mode, to fill the advancement chamber and the retardation chamber with the hydraulic oil in a state where the lock pin moves in the locking direction; anda position control device that sets the target position based on viscosity of the hydraulic oil, and controls a position of the spool so as to be the set target position when the mode selection device selects the oil filling mode as the control mode. |
