Back to results
US 2011/0214631 A1Published application
Variable valve device and method of controlling the same
AssigneeKomatsu Ltd.
InventorsEtsuro Sato, Hideaki Tachibana, Youhei Hisada, Kazuo Ohta
Life of this patent
Estimating the term…
Abstract
A variable valve device and a method of controlling the variable valve device, wherein, in order to prevent a shortage of oil film in a spool section, only the spool of a solenoid on/off valve is moved at a timing not affecting operation of an air intake valve, to thereby stabilize operation of the solenoid on/off valve.
Claims20
A variable valve device comprising:
- a valve actuation mechanism for moving an air intake valve of an engine to open or close an air intake port;
- a hydraulic actuator provided with a piston rod section for preventing the air intake valve from moving;
- a hydraulic control valve for controlling an operating oil supplied to or discharged from the hydraulic actuator, the hydraulic control valve having a spool and a slide surface on which the spool slides, the spool being configured so as to move between a prevented position at which the moving of the piston rod section of the hydraulic actuator is prevented and a released position at which the moving of the piston rod section is not prevented;
- valve stabilizing control means for performing a control valve stabilizing control for sliding the spool of the hydraulic control valve during a period where the valve actuation mechanism causes the air intake valve to fully close the air intake port;
- and
- variable valve control means for performing a variable valve control for sliding, while the air intake valve is being engaged in closing movement, the spool to the prevented side to prevent the moving of the piston rod section, stopping the closing movement of the air intake valve to thereby change a timing at which the air intake port is fully closed.
3 more elements
A method of controlling a variable valve device, wherein
- an air intake valve of an engine is moved by the valve actuation mechanism to open or close an air intake port;
- the moving of the air intake valve is prevented by a piston rod section of a hydraulic actuator;
- a valve member of the hydraulic control valve for controlling an operation oil to be supplied to or discharged from the hydraulic actuator is caused to move between a prevented position at which the moving of the piston rod section of the hydraulic actuator is prevented and a released position at which the moving of the piston rod section is not prevented, so as to control an operation of the piston rod section of the hydraulic actuator, to thereby change a timing at which the air intake port is fully closed,
- the method comprising:
- performing a control valve stabilizing control for sliding the spool of the hydraulic control valve between the released position and the prevented position during a period where the valve actuation mechanism causes the air intake valve to fully close the air intake port;
- and
- performing a variable valve control for sliding, while the air intake valve is being engaged in closing movement, the spool of the hydraulic control valve to the prevented side to prevent the moving of the piston rod section of the piston, stopping the closing movement of the air intake valve, to thereby change a timing at which the air intake port is fully closed.
4 more elements
Dependencies are inferred from the claim text.