Granted Patent B2

US 6,912,981 · App. 10/225,452 · Granted Jul 5, 2005

Abstract

Claims (22)

1. A method of correcting a cam phaser system failure comprising:

detecting a cam phaser system fault in a hydraulic cam phaser system having a solenoid valve; and

determining if the cam phaser fault is caused by a blockage in the solenoid valve supplying hydraulic fluid to the cam phaser; and

generating a control signal to the solenoid valve to release the blockage.

2. The method of claim 1 wherein the step of generating a control signal comprises generating a current signal to the solenoid valve to correct the cam phaser fault.

3. A method of detecting a fault on camshaft position in an internal combustion engine comprising:

providing a hydraulically-actuated cam phaser coupled to the camshaft;

providing a controller to control the position of the cam phaser;

detecting a hydraulic flow fault for the cam phaser;

generating a control signal to the cam phaser to correct said hydraulic flow fault

determining if the hydraulic flow fault is a fault caused by a blockage in a solenoid valve supplying hydraulic fluid to the cam phaser; and

wherein generating a control signal to the cam phaser comprises generating a control signal to the solenoid valve to release the blockage.

4. A cam phaser system comprising:

a hydraulically cam phaser;

a solenoid providing a flow of pressurized oil to said hydraulically-actuated cam phaser;

a controller for providing a control signal to said solenoid; and

wherein said controller determines if a hydraulic fault caused by a blockage has occurred with said solenoid and wherein said controller provides a control signal to said solenoid to release said blockage.

5. The cam phaser system of claim 4 wherein said control signal is a cyclic current that does not affect the position of said cam phaser.

6. The cam phaser system of claim 4 wherein said cam phaser is coupled to an exhaust camshaft.

7. The cam phaser system of claim 4 wherein said cam phaser is coupled to an intake cam shaft.

8. The cam phaser system of claim 4 wherein said cam phaser system is coupled to an internal combustion engine with an overhead cam configuration.

9. The cam phaser system of claim 4 wherein said cam phaser includes camshaft position feedback for said controller.

Assignments (13)