Exhaust valve device

Abstract

An exhaust valve device includes an exhaust valve formed by a valve body, a valve stem and a valve element, which opens and closes an exhaust passage provided in the valve body, mounted on the valve stem that is inserted into and supported rotatably by the valve body; and an actuator that drives the exhaust valve to open and close. The actuator includes an electric actuator, and an opening detection sensor to detect an opening of the exhaust valve. Further, the electric actuator and the opening detection sensor are disposed coaxially, a connecting shaft that connects the two is disposed parallel to and offset from the valve stem of the exhaust valve, and the connecting shaft and valve stem are connected by a link mechanism.

1 . An exhaust valve device comprising:
 an exhaust valve formed by a valve body, a valve stem and a valve element, which opens and closes an exhaust passage provided in the valve body, mounted on the valve stem that is inserted into and supported rotatably by the valve body; and   an actuator that drives the exhaust valve to open and close, the actuator comprising an electric actuator, and an opening detection sensor to detect an opening of the exhaust valve.   
   
   
       2 . The exhaust valve device according to  claim 1 , wherein the electric actuator and the opening detection sensor are disposed coaxially. 
   
   
       3 . The exhaust valve device according to  claim 2 , further comprising:
 a connecting shaft to connect the electric actuator to the opening detection sensor, the connecting shaft being disposed parallel to and offset from the valve stem of the exhaust valve; and   a rotation transmitter to connect the connecting shaft and the valve stem.   
   
   
       4 . The exhaust valve device according to  claim 3 , wherein the rotation transmitter comprises:
 a link mechanism including levers attached respectively to the connecting shaft and the valve stem; and   a rod to connect the levers.   
   
   
       5 . The exhaust valve device according to  claim 4 , wherein the lever attached to the connecting shaft is disposed between the electric actuator and the opening detection sensor in an axial direction. 
   
   
       6 . The exhaust valve device according to  claim 3 , further comprising a return spring to bias the exhaust valve in an opening direction at all times provided on the connecting shaft. 
   
   
       7 . The exhaust valve device according to  claim 1 , further comprising a protective cover to cover the electric actuator and the opening detection sensor. 
   
   
       8 . The exhaust valve device according to  claim 7 , wherein the protective cover includes a slit or an opening portion to release air that is formed in a ceiling portion of the protective cover. 
   
   
       9 . The exhaust valve device according to  claim 1 , wherein at least one of the exhaust valve and said electric actuator is fixed via thermal insulation packing. 
   
   
       10 . The exhaust valve device according to  claim 1 , wherein a magnitude relationship of θ 1 <θ 2 <θ 3  is established between an operating angle θ 1  of said exhaust valve, an operating angle θ 2  of said electric actuator, and a detection angle θ 3  of said opening detection sensor.