Process and system for compression release engine retarding

Claim 2

A process for compression release retarding of a multi-cylinder four cycle internal combustion engine having a rotatable crankshaft and an engine piston operatively connected to said crank- shaft for each cylinder thereof and having intake and exhaust valves for each cylinder thereof, said process being applicable to at least one of the multi-cylinders of the engine which in a normal operational powering or fueling mode has its piston moving in four cycles through a downward intake stroke, an upward compression stroke, a downward power stroke and an upward exhaust stroke during each two complete revolutions of the crankshaft, characterized in that during compression release retarding operation of the internal combustion engine the normal four cycle powering engine operation is converted to a two cycle operation by disabling, during each two revolutions of the crankshaft, the exhaust and intake valves from moving at the points they would normally move during normal engine operation and by modifying during said two crankshaft revolutions the normal open and closing times of the exhaust and intake valves to provide a compression release event for each revolution of the crankshaft.

Claim 3

The process of claim 1, characterized in that during the compression release retarding operation of the internal combustion engine, the normal compression, power, exhaust and intake strokes of the piston in the powering mode of the engine are converted to a first forced exhaust, a first forced intake, a forced compression, a second forced exhaust and a second forced intake.

Claim 4

The process of claim 1 or 2, characterized in that in the compression release retarding operation of the engine, for attaining said first forced exhaust, opening of the exhaust valve is commenced before the piston in its upward movement reaches the top dead center position of its normal compression stroke to produce a first compression release retarding event, closing said exhaust valve after the top dead center position of said engine piston, opening said intake valve during the ensuing downstroke of the piston to produce a first forced intake, closing said intake valve at substantially the ensuing bottom dead center position of said engine piston, disabling said exhaust valve from moving at the point it would move in the cycle during normal operation of the engine, disabling said intake valve from moving at the point it would move in the cycle during normal operation of the engine, commencing reopening said exhaust valve substantially at the ensuing top dead center position of the engine piston to produce a second compression release retarding event, reopening said intake valve during the next downstroke of the piston to produce a second forced intake, reclosing said exhaust valve after the top dead center position of said engine piston, reclosing said intake valve at substantially the ensuing bottom dead center position of said engine piston whereby one compression release event is produced in said one cylinder during each revolution of said crankshaft.

Claim 5

The process of claim 3, characterized in that the first opening motion of the exhaust valve is at about 40° BTDC and the first closing event of the exhaust valve is completed at about 180° ATDC, the first opening motion of the intake valve is at about 10° BTDC and the first closing event of the intake valve is completed at about 210° ATDC, the second opening motion of the exhaust valve is at about 350° ATDC, the second closing event of the exhaust valve is completed at about 450° ATDC, the sec opening motion of the intake valve is at about 370° ATD and the second closing event of the intake valve is complete at about 540° ATDC.

Claim 6

The process of claim 4, characterized in that the exhaust valve is disabled from moving at the point it would move in the cycle during the normal powering operation of the engine at least during the period from about 130° ATDC to about 370° ATDC and the intake valve is disabled from moving at the point it would move in the cycle during normal operation of the engine at least during the period from about 340° ATDC to about 580° ATDC.

Claim 7

The process of claim 3, characterized in that the first opening motion of the exhaust valve is at about 40° BTDC and the first closing event of the exhaust valve is completed at about 90° ATDC, the first opening motion of the intake valve is at about 30° ATDC and the first closing event of the intake valve is completed at about 180° ATDC, the second opening motion of the exhaust valve is at about 300° ATDC, the second closing event of the exhaust valve is completed at about 450° ATDC, the second opening motion of the intake valve is at about 380° ATDC and the second closing event of the intake valve is completed at about 540° ATDC.

Claim 8

The process of claim 6, characterized in that the exhaust valve is disabled from moving at the point it would move in the cycle during normal operation of the engine at least during the period from about 130° ATDC to about 370° ATDC and the intake valve is disabled from moving at the point it would move in the cycle during normal operation of the engine at least during the period from about 340° ATDC to about 580° ATDC.

Claim 9

An engine retarding system of a gas compression release type comprising a multi-cylinder four cycle internal combustion engine having a crank- shaft and a camshaft driven in synchronism with said crankshaft, engine pistons operatively connected with said crankshaft, exhaust valve means and intake valve means for each cylinder of the engine, first and second pushtubes driven from said camshaft, hydraulic fluid supply means, and an hydraulically actuated first piston operatively associated with said exhaust valve means to open said exhaust valve means, characterized by a second piston (162) actuated by said first pushtube (170) and hydraulically interconnected with said first piston (144) and said hydraulic fluid supply (102,104) to open said exhaust valve means (158) during an upstroke of the engine piston associated with said exhaust valve means corresponding to its compression stroke during normal powering operation of the engine to produce a first compression release event, first means (58,66,68,104 or 88,90,94) responsive to hydraulic pressure fluid supplied by said hydraulic fluid supply means adapted to disable the normal operation of said exhaust valve means, second means (58,66,68,144 or 88,90,94) responsive to hydraulic pressure supplied by said hydraulic fluid supply means adapted to disable the normal operation of said intake valve means, a third piston (184) associated with said intake valve means (180) and hydraulically interconnected with said first (144) and second (182) pistons to open said intake valve means at a predetermined time, a fourth piston (162a) actuated by said second pushtube (170a) and hydraulically interconnected with said first (144), second (162) and third (184) pistons to actuate said first piston (144) to open said exhaust valve means during an upstroke of the engine piston associated with said exhaust valve means (158), corresponding to its exhaust stroke during normal operation of the engine to produce a second compression release event and thereafter to actuate said third piston to open said intake valve means whereby one compression release event is produced in each cylinder during each revolution of said crankshaft.

Claim 10

An engine retarding system of a gas compression release type comprising a multi-cylinder four cycle internal combustion engine having a crank- shaft and a camshaft driven in synchronism with said crankshaft, engine pistons operatively connected with said crankshaft, exhaust valve means and intake valve means for each cylinder of the engine, first and second pushtubes driven from said camshaft, hydraulic fluid supply means, and an hydraulically actuated first piston operatively associated with said exhaust valve means to open said exhaust valve means, characterized by a second piston (162) actuated by said first pushtube (170) and hydraulically interconnected with said first piston (144) and said hydraulic fluid supply (102,104) to open said exhaust valve means (158) during an upstroke of the engine piston associated with said exhaust valve means corresponding to its compression stroke during normal powering operation of the engine to produce a first compression release event, first means (58,66,68,104 or 88,90,94) responsive to hydraulic pressure fluid supplied by said hydraulic fluid supply means adapted to disable the normal operation of said exhaust valve means, second means (58,66,68,144 or 88,90,94) responsive to hydraulic pressure supplied by said hydraulic fluid supply means adapted to disable the normal operation of said intake valve means, a third piston (184) associated with said intake valve means (180) and hydraulically interconnected with said first (144) and second (182) pistons to open said intake valve means at a predetermined time, a fourth piston (162a) actuated by said second pushtube (170a) and hydraulically interconnected with said first (144), second (162) and third (184) pistons to actuate said first piston (144) to open said exhaust valve means during an upstroke of the engine piston associated with said exhaust valve means (158), corresponding to its exhaust stroke during normal operation of the engine to produce a second compression release event and thereafter to actuate said third piston to open said intake valve means whereby one compression release event is produced in each cylinder during each revolution of said crankshaft.

Claim 11

The engine retarding system of claim 8, characterized in that after opening of said exhaust valve means under control of said second piston (162) and before operation of said first means adapted to disable said exhaust valve means, means (132,144) in the system closes the exhaust valve means after the top dead center position of said engine piston, means (189) is operative for opening said intake valve during the ensuing downstroke of the piston to produce a first forced intake, and means (162a) is operative for closing said intake valve at substantially the ensuing bottom dead center position of said engine piston, whereafter said first means disables said exhaust valve from moving at the point it would move in the cycle during normal operation of the engine.

Claim 12

The engine retarding system of claim 9, characterized in that after said second means disables the normal operation of the intake valve means, the exhaust valve means, under control of the first piston, commences its reopening at the ensuing top dead center position of the engine piston to produce said second compression release retarding event whereafter the same operational cycle takes place as after the first compression release retarding event.

Claim 13

An engine retarding system of a gas compression release type comprising a multi-cylinder four cycle internal combustion engine having a crank- shaft and a camshaft driven in synchronism with said crankshaft, engine piston means associated with said crankshaft, exhaust valve means and intake valve means associated with each cylinder of said engine, pushtube means driven from said camshaft and associated with each of said exhaust valves, hydraulic fluid supply means, first piston means associated with said exhaust valve means to open and close said exhaust valve means, and second piston means actuated by said pushtube means and hydraulically interconnected with said first piston means and said hydraulic fluid supply means, characterized by fluid pressure accumulator means (248) interposed between said first piston means (264) and said second piston means (162), said accumulator being adapted to receive hydraulic fluid pressurized by said second piston means (162), first solenoid valve means (260) interposed between said accumulator means (248) and said first piston means, hydraulically actuated exhaust valve means (58,66,68,104 or 88,90,94) supplied by said hydraulic fluid supply means, second solenoid valve means (272) communicating between said hydraulic fluid supply means and said exhaust valve disabling means, third piston means associated with said intake valve means (180) to open and close said intake valve means, solenoid means (280) interconnected with said third piston means, hydraulically actuated intake disabling means (58,66,68,104 or 88,90,94) supplied by said hydraulic fluid supply means, third solenoid valve means (276) communicating between said hydraulic fluid supply means and said intake disabling means, first check valve means (256) interposed between said accumulator (248) and said second piston means (162), second check valve means (244) interposed between said hydraulic fluid supply means and said second piston means, sensing means (230 or 238) responsive to the position of said crankshaft and electronic controller means (234) communicating electrically with said sensor means, said first, second and third solenoid valve means and said solenoid means.

Claim 14

An engine retarding system of a gas compression release type comprising a multi-cylinder four cycle internal combustion engine having a crank- shaft and a camshaft driven in synchronism with said crankshaft, engine piston means associated with said crankshaft, exhaust valve means and intake valve means associated with each cylinder of said engine, pushtube means driven from said camshaft and associated with each of said exhaust valves, hydraulic fluid supply means, first piston means associated with said exhaust valve means to open and close said exhaust valve means, and second piston means actuated by said pushtube means and hydraulically interconnected with said first piston means and said hydraulic fluid supply means, characterized by fluid pressure accumulator means (248) interposed between said first piston means (264) and said second piston means (162), said accumulator being adapted to receive hydraulic fluid pressurized by said second piston means (162), first solenoid valve means (260) interposed between said accumulator means (248) and said first piston means, hydraulically actuated exhaust valve means (58,66,68,104 or 88,90,94) supplied by said hydraulic fluid supply means, second solenoid valve means (272) communicating between said hydraulic fluid supply means and said exhaust valve disabling means, third piston means associated with said intake valve means (180) to open and close said intake valve means, solenoid means (280) interconnected with said third piston means, hydraulically actuated intake disabling means (58,66,68,104 or 88,90,94) supplied by said hydraulic fluid supply means, third solenoid valve means (276) communicating between said hydraulic fluid supply means and said intake disabling means, first check valve means (256) interposed between said accumulator (248) and said second piston means (162), second check valve means (244) interposed between said hydraulic fluid supply means and said second piston means, sensing means (230 or 238) responsive to the position of said crankshaft and electronic controller means (234) communicating electrically with said sensor means, said first, second and third solenoid valve means and said solenoid means.

Claim 15

A modification of the system of claim 11, characterized in that in place of the solenoid means there is provided a fourth solenoid valve means interposed between said accumulator means and said third piston means, said sensing means communicating electrically with said sensor means and first, second, third and fourth solenoid valve means.