Control system for a decompression engine brake

Abstract

Control system (5) for intake (1) and exhaust (2) valves of an internal combustion engine system, configured to control the valves (1, 2) to pass between a first configuration in which they do not cooperate in contact in a respective seat (4) of the engine system and a second configuration in which they cooperate in contact with said seat (5), and comprising a control system with cams (6) configured to control the opening and closing of the valves (1, 2) to allow the production of a driving torque by the engine system and to selectively control the opening and closing of at least one of the exhaust valves (2) to allow the production of a braking torque by said engine system.

1 . Control system for intake and exhaust valves of an internal combustion engine system, said control system being configured to control said valves to pass between a first configuration in which they do not cooperate in contact in a respective seat of said engine system and a second configuration in which they cooperate in contact with said seat, said control system comprising a control system with cams configured to control the opening and closing of said valve to allow the production of a driving torque by said engine system and to selectively control the opening and closing of at least one of said exhaust valves to allow the production of a braking torque by said engine system. 
     
     
         2 . Control system according to  claim 1 , wherein said cam system comprises a first cam mechanism configured to control said intake valves, a second cam mechanism configured to control said exhaust valves and a third cam mechanism configured to selectively control said exhaust valves, said first, second and third cam mechanisms each comprising a cam configured to actuate a respective rocker, said cams being carried by a same rotating shaft and said rockers being rotationally free on a same support shaft carried fixed by a base integral with said motor system. 
     
     
         3 . Control system according to  claim 2 , wherein said rocker of said third cam mechanism is configured to selectively actuate said rocker of said second cam mechanism. 
     
     
         4 . Control system according to  claim 2 , wherein said rocker of said third cam mechanism is configured to selectively actuate one of said intake valves. 
     
     
         5 . Control system according to  claim 2 , comprising a pair of exhaust valves rigidly connected by a common support, said common support being actuated by said rocker of said second cam mechanism for carrying both of said exhaust valves. 
     
     
         6 . Control system according to  claim 2 , comprising a pair of exhaust valves, one of said exhaust valves being rigidly connected by a common support, the other of said exhaust valves being carried in a movable way by said common support, said common support being actuated by said rocker of said second cam mechanism to carry both of said exhaust valves, said other of said exhaust valves being actuatable by said rocker of said third cam mechanism. 
     
     
         7 . Control system according to  claim 5 , wherein said rocker of said second cam mechanism cooperates in contact with said common support by means of a hydraulic tappet. 
     
     
         8 . Control system according to  claim 7 , wherein said tappet is collapsible. 
     
     
         9 . Control system according to  claim 2 , wherein said third cam mechanism is movable on said support shaft between a first maximum clearance position and a second minimum clearance position, said control system comprising an actuator mechanism configured to bring said third cam mechanism between said first and second positions. 
     
     
         10 . Control system according to  claim 9 , wherein said actuator mechanism comprises an eccentric device interposed between said support shaft and said rocker of said third cam mechanism and an actuator device configured to control said eccentric device for passing said rocker between said first and said second positions. 
     
     
         11 . Control system according to  claim 10 , wherein said actuator device is a device of the hydraulic type. 
     
     
         12 . Control system according to  claim 10 , wherein the actuator device is a device of the electro-hydraulic type. 
     
     
         13 . Control system according to  claim 9 , comprising elastic means interposed between said rocker of said third cam mechanism and said support and configured to keep said rocker in said first position. 
     
     
         14 . Control system according to  claim 2 , wherein said first cam and said second cam comprise a single actuating portion, said third cam comprising two actuating portions angularly spaced from each other in a circumferential direction with respect to said rotating shaft. 
     
     
         15 . Control system according to  claim 4 , wherein said first cam and said second cam comprise a single actuating portion, said third cam comprising four actuating portions angularly spaced from each other in a circumferential direction with respect to said rotating shaft. 
     
     
         16 . Control system according to  claim 15 , in which said hydraulic system is controlled in a synchronized manner with respect to said collapsible tappet. 
     
     
         17 . Internal combustion engine system comprising intake and exhaust valves, a cylinder system and defining respective seats for said valve, said engine system comprising a control system for said valves according to  claim 1 . 
     
     
         18 . Internal combustion engine system according to  claim 17 , wherein said cam system comprises a first cam mechanism configured to control said intake valves, a second cam mechanism configured to control said exhaust valves and a third cam mechanism configured to selectively control said exhaust valves, said first, second and third cam mechanisms each comprising a cam configured to actuate a respective rocker said cams being carried by a same rotating shaft and said rockers being rotationally free on a same support shaft carried fixed by a base integral with said motor system. 
     
     
         19 . Internal combustion engine system according to  claim 18 , wherein said rocker of said third cam mechanism is configured to selectively actuate said rocker of said second cam mechanism. 
     
     
         20 . Internal combustion engine system according to  claim 18 , wherein said rocker of said third cam mechanism is configured to selectively actuate one of said intake valves.