Variable valve actuating apparatus for internal combustion engine, and controller for variable valve actuating apparatus

Abstract

A variable valve actuating apparatus for an internal combustion engine includes an exhaust valve operating angle varying mechanism, and an exhaust valve timing varying mechanism. When the internal combustion engine is at rest, the exhaust: valve operating angle varying mechanism sets an exhaust valve operating angle relatively small, and the exhaust valve timing varying mechanism sets an exhaust valve opening timing and an exhaust valve closing timing relatively retarded. Accordingly, when the internal combustion engine is at rest, the variable valve actuating apparatus sets the exhaust valve closing timing at or close to top dead center so as to enable startup of the internal combustion engine.

1 . A variable valve actuating apparatus for an internal combustion engine, comprising:
 a first valve actuating mechanism arranged to vary at least an exhaust valve operating angle of the internal combustion engine, wherein when the internal combustion engine is at rest, the first valve actuating mechanism sets the exhaust valve operating angle relatively small; and   a second valve actuating mechanism arranged to vary an exhaust valve opening timing and an exhaust valve closing timing of the internal combustion engine, wherein when the internal combustion engine is at rest, the second valve actuating mechanism sets the exhaust valve opening timing and the exhaust valve closing timing relatively retarded,   wherein when the internal combustion engine is at rest, the first and second valve actuating mechanisms set the exhaust valve closing timing at or close to top dead center so as to enable startup of the internal combustion engine.   
   
   
       2 . The variable valve actuating apparatus as claimed in  claim 1 , wherein the first valve actuating mechanism is arranged to automatically set the exhaust valve operating angle relatively small when the internal combustion engine is at rest. 
   
   
       3 . The variable valve actuating apparatus as claimed in  claim 1 , wherein the second valve actuating mechanism is arranged to automatically set the exhaust valve opening timing and the exhaust valve closing timing relatively retarded when the internal combustion engine is at rest. 
   
   
       4 . The variable valve actuating apparatus as claimed in  claim 3 , wherein the second valve actuating mechanism includes a biasing device arranged to mechanically bias a movable member in a direction to retard the exhaust valve opening timing and the exhaust valve closing timing. 
   
   
       5 . The variable valve actuating apparatus as claimed in  claim 1 , wherein the second valve actuating mechanism includes a lock mechanism adapted to be operated by a hydraulic pressure generated by an oil pump driven by the internal combustion engine, and wherein at startup of the internal combustion engine, the lock mechanism maintains the exhaust valve opening timing and the exhaust valve closing timing as when the internal combustion engine is at rest. 
   
   
       6 . The variable valve actuating apparatus as claimed in  claim 1 , wherein the first valve actuating mechanism is arranged to vary an exhaust valve lift of the internal combustion engine according to variation of the exhaust valve operating angle. 
   
   
       7 . The variable valve actuating apparatus as claimed in  claim 1 , wherein the internal combustion engine is a compression ignition engine. 
   
   
       8 . The variable valve actuating apparatus as claimed in  claim 1 , wherein the internal combustion engine is one of a spark ignition engine and a compression ignition engine that uses both of compression ignition and spark ignition. 
   
   
       9 . A variable valve actuating apparatus for an internal combustion engine, comprising:
 a first valve actuating mechanism arranged to vary at least an exhaust valve operating angle of the internal combustion engine, wherein when de-energized, the first valve actuating mechanism mechanically sets the exhaust valve operating angle at or close to a minimum setpoint; and   a second valve actuating mechanism arranged to advance or retard an exhaust valve opening timing and an exhaust valve closing timing of the internal combustion engine, wherein when de-energized, the second valve actuating mechanism mechanically sets the exhaust valve opening timing and the exhaust valve closing timing at or close to a most retarded setpoint.   
   
   
       10 . The variable valve actuating apparatus as claimed in  claim 9 , wherein the first valve actuating mechanism is arranged to mechanically set the exhaust valve operating angle at the minimum setpoint when de-energized. 
   
   
       11 . The variable valve actuating apparatus as claimed in  claim 9 , wherein the second valve actuating mechanism is arranged to mechanically set the exhaust valve opening timing and the exhaust valve closing timing at the most retarded setpoint when de-energized. 
   
   
       12 . The variable valve actuating apparatus as claimed in  claim 11 , wherein the second valve actuating mechanism includes a biasing device arranged to mechanically bias a movable member in a direction to retard the exhaust valve opening timing and the exhaust valve closing timing. 
   
   
       13 . The variable valve actuating apparatus as claimed in  claim 9 , wherein the second valve actuating mechanism includes a lock mechanism adapted to be operated by a hydraulic pressure generated by an oil pump driven by the internal combustion engine, and wherein at startup of the internal combustion engine, the lock mechanism maintains the exhaust valve opening timing and the exhaust valve closing timing as when the internal combustion engine is at rest. 
   
   
       14 . The variable valve actuating apparatus as claimed in  claim 9 , wherein the internal combustion engine is a compression ignition engine. 
   
   
       15 . The variable valve actuating apparatus as claimed in  claim 9 , wherein the internal combustion engine is one of a spark ignition engine and a compression ignition engine that selectively uses one of compression ignition and spark ignition. 
   
   
       16 . A controller for a variable valve actuating apparatus for an internal combustion engine, the variable valve actuating apparatus comprising a first valve actuating mechanism arranged to vary at least an exhaust valve operating angle of the internal combustion engine, and a second valve actuating mechanism arranged to vary an exhaust valve opening timing and an exhaust valve closing timing of the internal combustion engine, the controller comprising:
 a section connected for signal communication therewith to the first and second valve actuating mechanisms, wherein at startup of the internal combustion engine, the section sets by the first valve actuating mechanism the exhaust valve operating angle relatively small, and sets by the second valve actuating mechanism the exhaust valve opening timing and the exhaust valve closing timing relatively retarded, so as to set the exhaust valve closing timing at or close to top dead center for enabling startup of the internal combustion engine.   
   
   
       17 . The controller as claimed in  claim 16 , wherein after startup of the internal combustion engine, the first and second valve actuating mechanisms maintain their respective operating positions as at startup of the internal combustion engine. 
   
   
       18 . The controller as claimed in  claim 17 , wherein the first valve actuating mechanism is electrically driven. 
   
   
       19 . The variable valve actuating apparatus as claimed in  claim 16 , wherein the internal combustion engine is a compression ignition engine. 
   
   
       20 . The controller as claimed in  claim 16 , wherein the section is built in an engine control unit for the internal combustion engine. 
   
   
       21 . A variable valve actuating apparatus for an internal combustion engine, comprising:
 a first valve actuating mechanism arranged to vary at least an exhaust valve operating angle of the internal combustion engine, wherein when the internal combustion engine is at rest, the first valve actuating mechanism is automatically held in a default operating position to set the exhaust valve operating angle smaller by a predetermined amount than a maximum setpoint;   a second valve actuating mechanism arranged to vary an exhaust valve lift phase of the internal combustion engine, wherein when the internal combustion engine is at rest, the second valve actuating mechanism is automatically held in a default operating position to set the exhaust valve lift phase more retarded by a predetermined amount than a most advanced setpoint; and   a controller connected for signal communication therewith to the first and second valve actuating mechanisms, wherein at an initial stage of startup of the internal combustion engine, the controller outputs a control signal so as to maintain the first valve actuating mechanism in or close to the default operating position, and maintain the second valve actuating mechanism in or close to the default operating position.