Claims
- 1. In a braking system for an internal combustion engine having an engine valve selectively openable in response to movement of a rotary cam about a cam shaft and a rocker assembly cooperative therewith, and having a control valve hydraulically connected to an engine valve assembly and thereby to said engine valve, wherein said engine is operable in either a power mode or a braking mode, the improvement comprising:means for checking hydraulic fluid to provide constant directional flow of hydraulic fluid for automatic lash adjustment of a valve actuating piston having an upper end and a lower end; and means for controlling a supply of hydraulic fluid in order to provide actuation of said engine valve by said piston.
- 2. The braking system of claim 1, wherein said engine valve assembly further comprises an accumulator slidably disposed in an accumulator bore in said upper end of said piston, said accumulator biased upward by an accumulator spring, having a swivel foot disposed on a valve stem of said engine valve, and wherein said lower end of said piston is in contact with said swivel foot.
- 3. The braking system of claim 2, wherein said hydraulic fluid checking means and said controlling means are combined in said control valve.
- 4. The braking system of claim 3, wherein said control valve further comprises a control valve body having an upper end and a lower end and being slidably disposed in a control valve bore in said rocker arm and biased upward by a control valve spring, an inner body having a ball seat formed therein, and a check ball disposed in said inner body and biased upward by a check spring.
- 5. The braking system of claim 4, wherein said control valve body further comprises an upper annulus located toward said upper end of said control valve body, a lower annulus located toward said lower end of said control valve body, a middle annulus located around said control valve body between said upper annulus and said lower annulus, a first horizontal bore which diametrically spans said control valve body, having each end of said first horizontal bore opening within said upper annulus, and a second horizontal bore, which diametrically spans said control valve body, having each end of said second horizontal bore opening within said middle annulus, and wherein a first vertical bore and a second vertical bore are axially disposed in said inner body about a longitudinal axis.
- 6. The braking system of claim 5, wherein said check ball is disposed in said second vertical bore, and wherein said first vertical bore connects said first horizontal bore with said second horizontal bore to provide hydraulic communication from said upper annulus, through said control valve body, to said middle annulus.
- 7. The braking system of claim 6 further comprising a hydraulic system having a switched low pressure supply circuit and a constant low pressure supply circuit connected to said hydraulic fluid supply and to said control valve, and a lashless fluid supply circuit and an accumulator control circuit connecting said control valve to said engine valve assembly.
- 8. The braking system of claim 7, wherein upon activation of a solenoid switch in braking mode, said control valve indexes in said control valve bore, aligning said middle annulus with said lashless fluid supply circuit and said accumulator control circuit so that said lashless fluid supply circuit and said accumulator control circuit become hydraulically locked and the motion of said cam is translated directly into the motion of said engine valve.
- 9. The braking system of claim 1, wherein said hydraulic fluid controlling means further comprises an accumulator control circuit and a switched low pressure supply circuit for providing clipping of said valve actuating piston and thereby providing lost motion braking.
- 10. The braking system of claim 9, further comprising a clipping/reset spool disposed in said cam shaft.
CROSS REFERENCE TO RELATED APPLICATIONS
This application relates to and claims priority on U. S. Provisional Applications Ser. No. 60/154,474, entitled “CHECK/SHUTTLE VALVE (CONTROL VALVE) FOR AN INTEGRATED LOST MOTION ROCKER BRAKE,” filed on Sep. 17, 1999 and Ser. No. 60/172,138, entitled “VALVE FOR LOST MOTION CLIP/RESET LOCATED IN THE ROCKER SHAFT,” filed on Dec. 17, 1999.
US Referenced Citations (12)
Provisional Applications (2)
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Number |
Date |
Country |
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60/154474 |
Sep 1999 |
US |
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60/172138 |
Dec 1999 |
US |