Valve
A valve, which is provided in an exhaust passage of an internal combustion engine to release exhaust, includes a valve seat having an opening opened to the exhaust passage, a valve body having a conical surface or a spherical surface configured to close the opening by coming into contact with the valve seat, a movement unit configured to move the valve body in a direction of intersecting the opening, and an urging unit configured to urge the valve body in the direction of intersecting the opening, and the urging unit controls urging force by the movement unit in a direction of suppressing vibration of the valve body caused by vibration of exhaust pulse frequency determined by a speed of the internal combustion engine and a number of cylinders of the internal combustion engine.
1. A valve provided in an exhaust passage of an internal combustion engine to release exhaust, the valve comprising:
a valve seat having an opening opened to the exhaust passage;
a valve body having a surface configured to close the opening by coming into contact with the valve seat;
an arm supporting the valve body;
an actuator configured to move the valve body with the arm in a direction of intersecting the opening; and
a spring configured to urge the valve body in the direction of intersecting the opening to close the valve,
wherein the actuator is configured to control the urging force of the spring in accordance with exhaust pulse frequency relating to the speed of the internal combustion engine,
the spring is set to have a spring constant suppressing vibration of the valve body caused by vibration of exhaust pulse frequency determined by a predetermined speed of the internal combustion engine and the number of cylinders of the internal combustion engine when the valve is closed and the valve body is pressed against the valve seat,
further comprising a storage medium storing set values of urging force in a plurality of stages relating to a predetermined engine speed or less, and a sensor monitoring the speed of the internal combustion engine,
wherein when the valve is closed and when the speed of the internal combustion engine is lower than the predetermined speed, the actuator is operated to further urge the valve body toward the valve seat in accordance with the urging force stored in the storage medium corresponding to the speed of the internal combustion engine whereby the actuator moves the valve body in a direction of suppressing vibration of the valve body caused by vibration of exhaust pulse frequency applied to the valve body.
2. The valve according to claim 1 , wherein:
the exhaust passage is joined to one exhaust passage by an exhaust path in accordance with the number of cylinders of the internal combustion engine; and
the valve seat is provided in the one joined exhaust passage.
3. A valve provided in an exhaust passage of an internal combustion engine to release exhaust, the valve comprising:
a valve seat having an opening opened to the exhaust passage;
a valve body having a surface configured to close the opening by coming into contact with the valve seat;
an arm supporting the valve body;
an actuator configured to move the valve body with the arm in a direction of intersecting the opening; and
an electromagnetic spring configured to urge the valve body in the direction of intersecting the opening to close the valve,
wherein
the actuator is configured to control the urging force of the electromagnetic spring in accordance with exhaust pulse frequency relating to the speed of the internal combustion engine,
the electromagnetic spring is set to have a spring constant suppressing vibration of the valve body caused by vibration of exhaust pulse frequency determined by a predetermined speed of the internal combustion engine and the number of cylinders of the internal combustion engine when the valve is closed and the valve body is pressed against the valve seat,
further comprising a storage medium storing set values of the spring constant in a plurality of stages relating to a predetermined engine speed or less, and a sensor monitoring the speed of the internal combustion engine,
wherein when the valve is closed and when the speed of the internal combustion engine is lower than the predetermined speed, the spring constant of the electromagnetic spring is increased in accordance with the spring constant stored in the storage medium corresponding to the speed of the internal combustion engine whereby vibration of the valve body caused by vibration of exhaust pulse frequency applied to the valve body is suppressed.
4. The valve according to claim 3 , wherein:
the exhaust passage is joined to one exhaust passage by an exhaust path in accordance with the number of cylinders of the internal combustion engine; and
the valve seat is provided in the one joined exhaust passage.
5. The valve according to claim 1 , wherein the surface of said valve body is conical.
6. The valve according to claim 1 , wherein the surface of said valve body is spherical.
7. The valve of claim 1 , wherein said spring is a coil spring.
8. The valve of claim 1 , wherein said spring is a leaf spring.
9. The valve according to claim 3 , wherein the surface of said valve body is conical.
10. The valve according to claim 3 , wherein the surface of said valve body is spherical.