Engine valve device

Abstract

An engine valve device includes an intake valve which opens and closes an intake port by a pressing force of a rotating cam and a pressing force of a valve spring, a piston which is movable in a same direction as the intake valve, a cylinder portion which houses the piston such that the piston is movable inside, a hydraulic actuator including the piston and the cylinder portion, a supply discharge pipe line which communicates with a pressure chamber formed by the piston and the cylinder portion, an accumulator which accumulates hydraulic oil flowed out from the pressure chamber via the supply discharge pipe line, and an electromagnetic on-off valve which controls a flow of the hydraulic oil between the pressure chamber and the accumulator. The electromagnetic on-off valve is arranged on the supply discharge pipe line between the hydraulic actuator and the accumulator.

1 . An engine valve device including a cam which rotates by engaging with a crankshaft, a rocker arm which follows a movement of the cam, and an intake valve which opens and closes an intake port by interacting the rocker arm and a spring, the engine valve device comprising:
 a piston which is movable in a same direction as that of the intake valve;   a cylinder which houses the piston such that the piston is movable inside the cylinder;   a hydraulic actuator including the piston and the cylinder;   a hydraulic pipe line which communicates with a pressure chamber formed by the piston and the cylinder;   an accumulation unit which accumulates hydraulic oil flowed out from the pressure chamber via the hydraulic pipe line; and   an electromagnetic on-off valve which controls a flow of the hydraulic oil between the pressure chamber and the accumulation unit, wherein   the hydraulic actuator, the hydraulic pipe line, the accumulation unit, and the electromagnetic on-off valve make up a hydraulic circuit, and   the electromagnetic on-off valve is arranged on the hydraulic pipe line between the hydraulic actuator and the accumulation unit.   
   
   
       2 . An engine valve device including a cam which rotates by engaging with a crankshaft, a rocker arm which follows a movement of the cam, and an intake valve which opens or closes an intake port by interacting the rocker arm and a spring, the engine valve device comprising a hydraulic circuit, wherein
 the hydraulic circuit includes:
 a hydraulic actuator which is activated by an open and close motion of the intake valve, the hydraulic actuator stopping a close motion of the intake valve in an open state when hydraulic oil is sealed in a pressure chamber; 
 an accumulation unit which accumulates the hydraulic oil flowed out from the pressure chamber of the hydraulic actuator when the intake valve moves to close, and which provides the hydraulic oil to the pressure chamber of the hydraulic actuator when the intake valve moves to open; and 
 an electromagnetic on-off valve which controls a flow of the hydraulic oil from the hydraulic actuator to the accumulation unit, wherein 
   the electromagnetic on-off valve is arranged between the hydraulic actuator and the accumulation unit.   
   
   
       3 . The engine valve device according to  claim 1 , further comprising a hydraulic oil supply unit which provides the hydraulic oil to the hydraulic circuit. 
   
   
       4 . The engine valve device according to  claim 3 , wherein the hydraulic oil supply unit is a lubrication unit which provides lubricating oil to an engine and is attached to the engine. 
   
   
       5 . The engine valve device according to  claim 1 , further comprising an auxiliary pipe line which allows the flow of the hydraulic oil from the pressure chamber of the hydraulic actuator to the accumulation unit, wherein
 the auxiliary pipe line includes a port which opens when the piston of the hydraulic actuator comes to a predetermined section, the piston of the hydraulic actuator follows the intake valve moving to a closing direction.   
   
   
       6 . The engine valve device according to  claim 3 , further comprising a check valve which supplies the hydraulic oil from the hydraulic oil supply unit to the hydraulic circuit only if an oil pressure of the hydraulic circuit is lower than that of the hydraulic oil supply unit, and the check valve is arranged between the hydraulic oil supply unit and the hydraulic circuit. 
   
   
       7 . The engine valve device according to  claim 1 , wherein the pressure chamber of the hydraulic actuator is configured to cushion a shock when the intake valve closes. 
   
   
       8 . The engine valve device according to  claim 2 , further comprising:
 a push rod which transmits motion from the cam to the rocker arm, the push rod being disposed between the cam and the rocker arm; and   a biasing unit which biases the rocker arm to tightly contact with the push rod.   
   
   
       9 . The engine valve device according to  claim 2 , further comprising a hydraulic oil supply unit which provides the hydraulic oil to the hydraulic circuit. 
   
   
       10 . The engine valve device according to  claim 9 , wherein the hydraulic oil supply unit is a lubrication unit which provides lubricating oil to an engine and is attached to the engine. 
   
   
       11 . The engine valve device according to  claim 2 , further comprising an auxiliary pipe line which allows the flow of the hydraulic oil from the pressure chamber of the hydraulic actuator to the accumulation unit, wherein
 the auxiliary pipe line includes a port which opens when the piston of the hydraulic actuator comes to a predetermined section, the piston of the hydraulic actuator follows the intake valve moving to a closing direction.   
   
   
       12 . The engine valve device according to  claim 9 , further comprising a check valve which supplies the hydraulic oil from the hydraulic oil supply unit to the hydraulic circuit only if an oil pressure of the hydraulic circuit is lower than that of the hydraulic oil supply unit, and the check valve is arranged between the hydraulic oil supply unit and the hydraulic circuit. 
   
   
       13 . The engine valve device according to  claim 2 , wherein the pressure chamber of the hydraulic actuator is configured to cushion a shock when the intake valve closes.