System to diagnose variable valve actuation malfunctions by monitoring fluid pressure in a control gallery

Patent metadata

Field	Value
Publication number	US-9291075-B2
Application number	US-201313873774-A
Country	US
Kind code	B2
Filing date	Apr 30, 2013
Priority date	Jul 22, 2008
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A system for diagnosing malfunctions in a variable valve actuation device is disclosed. The system has a rocker arm assembly that includes: a first arm, a second arm with the first and second arms attached at a first end, a hydraulically operated latch assembly that functions to secure the first arm to the second arm when latched. It also includes a source of pressurized fluid connected to a hydraulic valve that provided fluid high or low pressure fluid to the hydraulically-operated latch. The latch may be operated by a remote device. A control gallery connects the hydraulic valve to the latch. A pressure transducer is positioned within the gallery and is adapted to create a signal indicating the pressure in the gallery. A control unit is coupled to the hydraulic valve and the pressure transducer, and is adapted to sense engine operation parameters, actuate the hydraulic valve, read the signal from the pressure transducer; and identify malfunctions of the rocker arm assembly based upon the signal from the transducer.

First claim

What is claimed is:

1. A system for diagnosing malfunctions in a variable valve actuation system comprising:
a rocker arm assembly comprising:
a first arm with a first end;
a second arm with a first end pivotally connected to the first arm, the first end of the first arm and the first end of the second arm both pivoting about a same pivot axis;
a hydraulically-operated latch assembly functioning to secure the first arm to the second arm when latched for operation in a first operating mode and functioning to allow the first arm to move relative to the second arm when unlatched in a second operating mode;
a source of pressurized fluid;
a hydraulic valve coupled to the source of pressurized fluid, adapted to provide pressurized fluid to the hydraulically-operated latch assembly;
a gallery connecting the hydraulic valve to the hydraulically-operated latch assembly;
a pressure transducer for indicating a pressure in the gallery; and
a control unit coupled to the hydraulic valve and the pressure transducer, adapted to:
accept a hydraulic pressure input from the pressure transducer; and
identify motion of a latch of the hydraulically-operated latch assembly based upon the hydraulic pressure input from the pressure transducer.

2. The system of claim 1 wherein the control unit is further adapted to:
sense engine operation parameters; and
actuate the hydraulic valve.

3. The system of claim 1 wherein the control unit is further adapted to:
identify when the latch has been actuated based upon the hydraulic pressure input from the pressure transducer.

4. The system of claim 1 wherein the control unit is further adapted to: calculate a velocity of the latch based upon the hydraulic pressure input from the pressure transducer.

5. The system of claim 1 wherein the control unit is further adapted to: calculate when the latch is moving slower than a predetermined acceptable velocity.

6. The system of claim 1 wherein the control unit is further adapted to: store previously calculated latch velocities and determine changes in the velocities over time to identify a probability that the latch will not respond within a predetermined acceptable time period.

7. The system of claim 1 wherein the control unit is further adapted to: calculate a velocity of the latch based upon a measured slope of a time vs. hydraulic pressure input from the pressure transducer.

8. The system of claim 1 , further comprising a second source of pressurized fluid connected to the hydraulically-operated latch assembly.

9. A system for diagnosing malfunctions in a variable valve actuation system comprising:
a hydraulically-operated latch assembly;
a first source of pressurized fluid;
a hydraulic valve coupled to the first source of pressurized fluid and adapted to provide pressurized fluid through the hydraulic valve to the hydraulically-operated latch assembly;
a gallery connecting the hydraulic valve to the hydraulically-operated latch assembly;
a pressure transducer for measuring a hydraulic pressure in the gallery; and
a control unit coupled to the hydraulic valve and the pressure transducer, adapted to:
receive a hydraulic pressure input from the pressure transducer; and
identify motion of a latch of the hydraulically-operated latch assembly in the variable valve actuation system based upon an input from the pressure transducer.

10. The system of claim 9 , further comprising:
a rocker arm assembly comprising:
a first arm with a first end; and
a second arm with a first end pivotally connected to the first arm, the first end of the first arm and the first end of the second arm both pivoting about a same pivot axis and
wherein the hydraulically-operated latch assembly secures the first arm to the second arm when the latch is latched for operation in a first operating mode and functioning to allow the first arm to move relative to the second arm when unlatched in a second operating mode.

11. The system of claim 9 , further comprising a second hydraulically-operated latch assembly also provided with a first source of pressurized fluid, wherein the hydraulically-operated latch assembly and the second hydraulically-operated latch assembly are operably connected to rocker arm assemblies of two cylinders of an internal combustion engine.

12. The system of claim 9 , wherein the hydraulically-operated latch assembly further comprises a dual-feed hydraulic lash adjuster (DFHLA).

13. The system of claim 9 , wherein the gallery comprises an upper gallery and is a pressurized vessel of hydraulic fluid.

14. The system of claim 9 , further comprising a second source of pressurized fluid connected to the hydraulically-operated latch assembly.

15. The system of claim 14 , wherein the second source of pressurized fluid comprises a lower gallery and is a pressurized vessel of hydraulic fluid.

16. A system for diagnosing malfunctions in a variable valve actuation system comprising:
a hydraulically-operated latch assembly;
a hydraulic valve coupled to a first source of pressurized fluid and adapted to provide pressurized fluid through the hydraulic valve to the hydraulically-operated latch assembly;
a pressure transducer for measuring a pressure of the pressurized fluid provided by the first source of pressurized fluid; and
a control unit coupled to the hydraulic valve and the pressure transducer, adapted to:
receive a hydraulic pressure input from the pressure transducer; and
identify motion of a latch of the hydraulically-operated latch assembly in a variable valve actuation system based upon an input from the pressure transducer.

17. The system of claim 16 , further comprising an upper gallery connecting the hydraulic valve to the hydraulically-operated latch assembly.

18. The system of claim 16 , further comprising a second source of pressurized fluid connected to the hydraulically-operation latch assembly.

19. The system of claim 18 , wherein the second source of pressurized fluid comprises a lower gallery.

20. The system of claim 16 , further comprising:
a rocker arm assembly comprising:
a first arm with a first end; and
a second arm with a first end pivotally connected to the first arm, wherein the first end of the first arm and the first end of the second arm both pivoting about a same pivot axis, and
wherein the hydraulically-operated latch assembly secures the first arm to the second arm when the latch is latched for operation in a first operating mode and functioning to allow the first arm to move relative to the second arm when unlatched in a second operating mode.

21. The system of claim 16 , wherein one indication of a malfunction in the variable valve actuation system comprises an unexpected time shifting of a pressure increase or pressure decrease during latching or unlatching.

22. The system of claim 16 , wherein one indication of a malfunction in the variable valve actuation system comprises a difference from an expected rate of increase or decrease of pressure during latching or unlatching.

23. The system of claim 16 , wherein the control unit is adapted to yield an indication of a malfunction in the variable valve actuation system independent of direct measurement of a valve lift or a latch pin movement.

Assignees

• Eaton Corp

Inventors

• Zurface Austin Robert
• Boychuk Robert
• Vandeusen Brian Karl

Classifications

• F01L2301/00

  Using particular materials · CPC title

• F01L1/2405

  by means of a hydraulic adjusting device located between the cylinder head and rocker arm · CPC title

• F01L2800/11

  Fault detection, diagnosis · CPC title

• F01L13/0036

  the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction · CPC title

• F01L2820/043

  Pressure · CPC title