Systems, methods and devices for rocker arm position sensing
A system for monitoring operation of an internal combustion engine having a rocker arm assembly for actuating an engine valve is disclosed. The rocker arm assembly includes a first arm with a first end, a second arm also having a first end pivotally connected near the first end of the first arm, a latch that when latched secures the first arm relative to the second arm in a latched mode, and when unlatched allows the first arm to move relative to the second arm in an unlatched mode. The system also employing a sensor attached to one of the first and second arms that can detect when the arms are moving relative to each other, and adapted to provide a signal indicating the sensed movement.
1. A system for monitoring operation of an internal combustion engine, comprising:
a rocker arm assembly having:
a first arm having a first end;
a second arm having a first end, the second arm pivotally connected near the first end of the first arm along a pivot having a pivot axis;
a reference structure comprising magnetic material forming at least a portion of the first end of the first arm; and
a latch that when latched secures the first arm relative to the second arm in a latched mode, and when unlatched allows the first arm to move relative to the second arm in an unlatched mode;
wherein the rocker assembly is adapted to pivot about the pivot axis to open an engine valve and return to a position in which the engine valve is closed; and
a sensor positioned near the rocker arm assembly adapted to provide a signal indicating proximity of the reference structure to the sensor.
2. The system of claim 1 wherein the reference structure is an outer arm tie bar.
3. The system of claim 1 wherein the reference structure is a structure near the first end of the first arm.
4. The system of claim 1 wherein the reference structure is metal and the sensor creates a signal relative to its distance from a metal object.
5. The system of claim 1 wherein the sensor is a non-contact sensor.
6. The system of claim 1 wherein the sensor is an optical sensor.
7. The system of claim 1 wherein the sensor is a Hall-effect sensor.
8. The system of claim 1 wherein when the rocker arm assembly is in the latched mode, it can provide a first lift height to the engine valve.
9. The system of claim 1 wherein when the rocker arm assembly is in the unlatched mode, it can provide a second lift height to the engine valve.
10. The system of claim 8 wherein the second lift height is lower than the first lift height.
11. A system for monitoring operation of an internal combustion engine, comprising:
a rocker arm assembly for actuating an engine valve, the rocker arm assembly comprising:
a first arm having a first end;
a second arm having a first end, the second arm pivotally connected near the first end of the first arm along a pivot having a pivot axis;
a latch that when latched secures the first arm relative to the second arm in a latched mode, and when unlatched allows the first arm to move relative to the second arm in an unlatched mode; and
a sensor attached to at least one of the first and second arms that can detect motion of the arms relative to each other, and adapted to provide a signal indicating the detected motion.
12. The system of claim 11 wherein the sensor comprises:
magnetic material connected to at least one of the first arm and the second arm; and
a coil sufficiently near the magnetic material wherein relative motion of the magnetic material relative to the coil creates a signal indicating that the rocker arm assembly is not in the latched mode.
13. The system of claim 11 wherein the sensor is a non-contact sensor.
14. The system of claim 11 wherein the sensor is an optical sensor.
15. The system of claim 11 wherein the sensor is a Hall-effect sensor.
16. A system for monitoring operation of an internal combustion engine, comprising:
a rocker arm assembly for actuating an engine valve having:
a first arm having a first end;
a second arm having a first end, the second arm pivotally connected near the first end of the first arm along a pivot having a pivot axis;
a latch that when latched secures the first arm relative to the second arm in a latched mode, and when unlatched allows the first arm to move relative to the second arm in an unlatched mode; and
a sensor for detecting motion of the first arm and second arm relative to each other, the sensor adapted to provide a signal indicating the detected motion.
17. The system of claim 16 , wherein the first end of the first arm comprises a tie bar.
18. The system of claim 16 , wherein the sensor is mounted on the rocker arm assembly.
19. The system of claim 16 , wherein the sensor is mounted on one of the first arm and the second arm.