Variable valve opening property internal combustion engine

A variable valve opening property internal combustion engine, comprising:

• an engine valve provided in a combustion chamber at least partly defined by a cylinder head of the engine and biased in a valve closing direction by a valve spring;
• a rocker arm pivotally supported by the cylinder head and having an end acting upon a valve stem of the engine valve for opening the engine valve;
• a camshaft rotatably supported by the cylinder head and carrying a cam;
• a roller link including a cam engaging part configured to engage the cam and a rocker arm engaging part engaging a slipper surface of the rocker arm, and adjustably supported by the cylinder head for a guided motion of the cam engaging part;
• a control link for adjusting a trajectory of the guided motion of the cam engaging part;
• an actuator for actuating the control link;
• and
• a spring device mounted on the cylinder head and provided with a pressure surface that acts upon a spring engaging part of the roller link so as to bias the cam engaging part against the cam;
• wherein the pressure surface extends by a prescribed distance so as to accommodate a guided movement of the spring engaging part caused by an adjustment of the trajectory of the guided motion of the cam engaging part by the control link, wherein the spring device comprises at least a pair of compression springs arranged along direction of the guided movement of the spring engaging part.

A variable valve opening property internal combustion engine, comprising:

• an engine valve provided in a combustion chamber at least partly defined by a cylinder head of the engine and biased in a valve closing direction by a valve spring;
• a rocker arm pivotally supported by the cylinder head and having an end acting upon a valve stem of the engine valve for opening the engine valve;
• a camshaft rotatably supported by the cylinder head and carrying a cam;
• a roller link including a cam engaging part configured to engage the cam and a rocker arm engaging part engaging a slipper surface of the rocker arm, and adjustably supported by the cylinder head for a guided motion of the cam engaging part;
• a control link for adjusting a trajectory of the guided motion of the cam engaging part;
• an actuator for actuating the control link;
• and
• a spring device mounted on the cylinder head and provided with a pressure surface that acts upon a spring engaging part of the roller link so as to bias the cam engaging part against the cam;
• wherein the pressure surface extends by a prescribed distance so as to accommodate a guided movement of the spring engaging part caused by an adjustment of the trajectory of the guided motion of the cam engaging part by the control link, wherein the pressure surface is contoured such that an angle between a trajectory of the guided motion of the spring engaging part and a direction of a pressure applied by the pressure surface onto the spring engaging part may be minimized.