Valve train system of internal combustion engine

Abstract

An object of the present invention is to simplify a valve train system that can change valve operation characteristics of an intake valve(s) and/or an exhaust valve(s) mounted on an internal combustion engine while improving the response in changing valve operation characteristics. To achieve this object, according to the present invention, a valve train system of an internal combustion engine that can change valve operation characteristics of an intake valve and/or an exhaust valve comprises a plurality of changing mechanisms that change valve operation characteristics by connecting/disconnecting a plurality of power transmission members provided between a cam and a valve to/from each other, a switching pin that is provided in each changing mechanism in such a way as to be able to move forward and backward to provide switching between connection and disconnection of the plurality of power transmission members, an actuator that generates power for moving the switching pin forward and backward, and a distribution mechanism that distributes the power generated by one actuator to a plurality of switching pins.

1 - 11 . (canceled) 
     
     
         12 . A valve train system of an internal combustion engine that can change valve operation characteristics of an intake valve and/or an exhaust valve provided on an internal combustion engine, comprising:
 a plurality of changing mechanisms that change valve operation characteristics by connecting/disconnecting a plurality of power transmission members provided between a cam and a valve to/from each other;   a switching pin that is provided in each changing mechanism in such a way as to be able to move forward and backward to provide switching between connection and disconnection of the plurality of power transmission members;   an actuator that generates power for moving the switching pin forward and backward; and   a distribution mechanism that distributes the power generated by one actuator to a plurality of switching pins,   wherein said plurality of power transmission members include a first swing member that is caused to swing by a cam and a second swing member that swings with the operation of the valve,   said switching pin is supported by one of said first swing member and said second swing member in such a way as to be able to move forward and backward and inserted/retracted into/out of an engagement bore provided in the other of said first swing member and said second swig member,   said distribution mechanism comprises a shift member that can shift with the forward and backward motion of the plurality of switching pins,   said actuator comprises a biasing member that biases said shift member in the direction of forward motion of said switching pins and a drive unit that causes said shift member to shift in the direction of backward motion of said switching pins utilizing a torque of a cam.   
     
     
         13 . A valve train system of an internal combustion engine according to  claim 12 , further comprising a helical groove provided on an outer circumferential surface of a rotary member that rotates with the cam, and an insert pin that is attached on said shift member and can be inserted/removed into/out of said helical groove, wherein said drive unit inserts/removes said insert pin into/out of said helical groove. 
     
     
         14 . A valve train system of an internal combustion engine according to  claim 13 , wherein said shift member comprises a shaft member that is in contact with said switching pins, can move forward and backward in the same direction as the switching pins, and can rotate in a circumferential direction and a pivoting member that is fixed to said shaft member and can pivot about the shaft member serving as a pivot, said insert pin is attached on said pivoting member, and said drive unit presses said pivoting member to thereby insert said insert pin into said helical groove. 
     
     
         15 . A valve train system of an internal combustion engine according to  claim 14 , wherein said insert pin is provided between a portion of said pivoting member that is in contact with said drive unit and a portion of said pivoting member that is connected with said shaft member. 
     
     
         16 . A valve train system of an internal combustion engine according to  claim 14 , wherein a volume portion is provided on a surface of said pivoting member that faces in a direction in which said insert pin is removed from the helical groove and in a direction in which the weight of the pivoting member acts. 
     
     
         17 . A valve train system of an internal combustion engine according to  claim 13 , further comprising a restraining mechanism that restrains a shift of said shift member in the forward direction when said shift member has shifted to reach its backside extremity. 
     
     
         18 . A valve train system of an internal combustion engine according to  claim 13 , further comprising a control means for controlling the actuator in such a way that the first swing member and the second swing member are disconnected at a time when a fuel cut operation of the internal combustion engine is started. 
     
     
         19 . A valve train system of an internal combustion engine according to  claim 13 , further comprising a sub cam that rotates while being in contact with said second swing member, wherein said sub cam has a cam profile different from that of said cam.