# US 2014/0150744 A1 · Valve timing adjusting system

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- Number: US 2014/0150744 A1
- Document ID: US20140150744A1
- Status: Published application
- Kind: A1
- Application number: 14/131,185
- Filed: 2012-07-05
- Published: 2014-06-05
- Earliest claimed: 2011-07-12
- Assignees: Aisin Seiki Kabushiki Kaisha
- Inventors: Yuji Kakuda; Satoshi Kokubo; Kenji Ikeda; Masaki Kobayashi; Yuuki Ohta
- Web page: https://patentgrep.com/patent/US20140150744A1

## CPC

- F01L 1/3442: {using hydraulic chambers with variable volume to transmit the rotating force}
- F02D 13/0219: {by shifting the phase, i.e. the opening periods of the valves are constant}
- F01L 2001/3443: {Solenoid driven oil control valves}
- F01L 2001/34463: {Locking position intermediate between most retarded and most advanced positions}
- F01L 2001/34466: {with multiple locking devices}
- F01L 2001/34469: {Lock movement parallel to camshaft axis}
- F01L 2001/34476: {Restrict range locking means}
- F01L 2001/34483: {Phaser return springs}
- F01L 2250/02: the camshaft being driven by chains
- F01L 2800/00: Methods of operation using a variable valve timing mechanism
- F01L 2800/11: Fault detection, diagnosis
- Y02T 10/12: Improving ICE efficiencies
- F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A valve timing adjusting system includes a displacement mechanism unit that displaces a camshaft rotational phase relative to a crankshaft, a locking mechanism unit that locks the rotational phase, and a control unit that controls operations of a hydraulic control valve. The control unit includes a property obtainment unit that obtains property information regarding hydraulic properties, and a lock release process completes locking release by supplying oil pressure to the locking mechanism unit for moving the rotational phase from an intermediate locked phase toward one of a retard/advance position, and then supplying oil pressure to the locking mechanism unit for moving the rotational phase toward the other of the retard/advance position; the rotational phase stands by at a predetermined position of the one of the retard/advance position past the intermediate locked phase during the lock release process, until a standby time has elapsed.

## Claims

### Claim 1

A valve timing adjusting system comprising:
a displacement mechanism unit that displaces a rotational phase of a camshaft relative to a crankshaft of an internal combustion engine between a retard position and an advance position, a locking mechanism unit that locks the rotational phase at an intermediate locked phase positioned within a displacement range of the rotational phase by inserting a locking pin into a locking recess, a hydraulic pathway having a hydraulic control valve that hydraulically drives the displacement mechanism unit and the locking mechanism unit, and a control unit having a control system that controls operations of the hydraulic control valve,
wherein the control unit includes a property obtainment unit that obtains property information regarding hydraulic properties of the hydraulic pathway;
a lock release process that releases the locking of the locking mechanism unit completes the locking release by supplying oil pressure to the locking mechanism unit for moving the rotational phase from the intermediate locked phase toward one of the retard position and the advance position, and then supplying oil pressure to the locking mechanism unit for moving the rotational phase toward the other of the retard position and the advance position;
the rotational phase is caused to stand by at a predetermined position of the one of the retard position and the advance position past the intermediate locked phase during the lock release process, until a standby time has elapsed; and
the system further comprises a standby time changing unit that changes the standby time based on the property information.

### Claim 2 (depends on 1)

The valve timing adjusting system according to claim 1,
wherein the property information includes at least one of an oil temperature, an oil pressure, an RPM of a hydraulic pump, and a degree of oil degradation in the hydraulic pathway.

### Claim 3 (depends on 1)

The valve timing adjusting system according to claim 1,
wherein the standby time changing unit includes a correction unit that extends and corrects the standby time in the case where a lock release failure has been detected in the locking mechanism unit.

### Claim 4 (depends on 3)

The valve timing adjusting system according to claim 3,
wherein the correction unit is a learning-based correction unit that calculates a correction amount for the standby time based on a learning result from a plurality of lock release failures.

### Claim 5 (depends on 1)

The valve timing adjusting system according to claim 1, further comprising:
an abnormality determination unit that outputs an abnormal signal when the standby time extended by the standby time changing unit exceeds a threshold.