초록 ▼

An exhaust valve assembly includes a flapper valve fixed to a valve shaft where the flapper valve is movable between a closed position, an intermediate position, and an open position. A resilient member biases the flapper valve toward the closed position. An electric actuator actively moves the flap

An exhaust valve assembly includes a flapper valve fixed to a valve shaft where the flapper valve is movable between a closed position, an intermediate position, and an open position. A resilient member biases the flapper valve toward the closed position. An electric actuator actively moves the flapper valve at least from the closed position to the intermediate position. A coupling mechanism couples the valve shaft to an electric actuator shaft and allows the flapper valve to move to the open position in response to exhaust flow sufficient to overcome a biasing force of the resilient member without requiring input from the electric actuator.

대표청구항 ▼

What is claimed is: 1. An exhaust valve assembly comprising: a shaft; a flapper valve fixed to said shaft and movable relative to an exhaust component housing between a closed position, an intermediate position, and an open position; a resilient member biasing said flapper valve toward said closed

What is claimed is: 1. An exhaust valve assembly comprising: a shaft; a flapper valve fixed to said shaft and movable relative to an exhaust component housing between a closed position, an intermediate position, and an open position; a resilient member biasing said flapper valve toward said closed position; an electric actuator coupled to said shaft to actively move said flapper valve at least from said closed position to said intermediate position; and a coupling mechanism that couples said electric actuator to said shaft, said coupling mechanism allowing said flapper valve to move to said open position in response to exhaust flow sufficient to overcome a biasing force of said resilient member without requiring input from said electric actuator. 2. The exhaust valve assembly according to claim 1 wherein said electric actuator only actively moves said flapper valve from said closed position to said intermediate position, and wherein said flapper valve is passively moved from said intermediate position to said open position in response to exhaust flow sufficient to overcome said biasing force. 3. The exhaust valve assembly according to claim 1 wherein said electric actuator actively moves said flapper valve from one of said closed position, said intermediate position, and said open position to another of said closed position, said intermediate position, and said open position in response to an engine signal identifying an engine operating condition. 4. The exhaust valve assembly according to claim 3 wherein said engine operation condition comprises at least one of a number of operational engine cylinders and engine throttle/load conditions. 5. The exhaust valve assembly according to claim 1 wherein said electric actuator actively moves said flapper valve from said closed position to said intermediate position, and from said intermediate position to said open position. 6. The exhaust valve assembly according to claim 1 wherein said flapper valve passively moves from said closed position to said open position when said electric actuator fails and when exhaust flow is sufficient to overcome said biasing force. 7. The exhaust valve assembly according to claim 1 wherein said coupling mechanism comprises a coupling disc fixed to said shaft and an actuator disc fixed to an output from said electric actuator, wherein one of said coupling disc and actuator disc includes a pair of arcuate slots that receive a pair of pins associated with the other of said coupling disc and said actuator disc. 8. The exhaust valve assembly according to claim 7 wherein each pin is positioned at an end of one of said pair of slots when said electric actuator is in a neutral position. 9. The exhaust valve assembly according to claim 8 wherein said electric actuator rotates said actuator disc such that each pin drives against said ends of an associated slot to rotate said coupling disc and move said flapper valve to said intermediate position, said intermediate position defining a maximum rotational limit for said electric actuator. 10. The exhaust valve assembly according to claim 1 wherein said coupling mechanism comprises a coupling sleeve fixed for rotation with an output shaft of said electric actuator, and wherein said coupling sleeve is coupled to said resilient member. 11. The exhaust valve assembly according to claim 10 including a spring retainer fixed to an end of said shaft, said resilient member having a first end fixed to said shaft via said spring retainer and a second end fixed to said coupling sleeve. 12. The exhaust valve assembly according to claim 11 wherein said coupling sleeve includes at least one slot that receives said second end of said resilient member. 13. An exhaust valve assembly comprising: a shaft; a flapper valve fixed to said shaft and movable relative to an exhaust component housing between a closed position, an intermediate position, and an open position; a resilient member biasing said flapper valve toward said closed position; an electric actuator coupled to said shaft to actively move said flapper valve at least from said intermediate position to said open position; and a coupling mechanism that couples said electric actuator to said shaft, said coupling mechanism allowing said flapper valve to move to said intermediate position in response to exhaust flow sufficient to overcome a biasing force of said resilient member without requiring input from said electric actuator. 14. The exhaust valve assembly according to claim 13 wherein said electric actuator only actively moves said flapper valve from said intermediate position to said open position, and wherein said flapper valve is passively moved from said closed position to said intermediate position in response to exhaust flow sufficient to overcome said biasing force. 15. The exhaust valve assembly according to claim 13 wherein said electric actuator actively moves said flapper valve from at least one of said closed position, said intermediate position, and said open position toward another of said closed position, said intermediate position, and said open position in response to an engine signal identifying an engine operating condition that comprises at least one of a number of operational engine cylinders and engine throttle/load conditions. 16. The exhaust valve assembly according to claim 13 wherein said coupling mechanism comprises a coupling sleeve fixed for rotation with an output shaft of said electric actuator, and wherein said coupling sleeve is coupled to said resilient member. 17. The exhaust valve assembly according to claim 13 wherein said coupling mechanism comprises a coupling disc fixed to said shaft and an actuator disc fixed to an output from said electric actuator, wherein one of said coupling disc and actuator disc includes a pair of arcuate slots that receive a pair of pins associated with the other of said coupling disc and said actuator disc. 18. A method for controlling actuation of an exhaust valve assembly between at least closed, intermediate, and open positions comprising: (a) biasing a flapper valve supported on a shaft toward the closed position; (b) actively actuating the flapper valve with an electric actuator to move the flapper valve from at least the intermediate position to the open position; and (c) coupling the electric actuator to the shaft to allow the flapper valve to move to the intermediate position in response to exhaust flow sufficient to overcome a biasing force defined in step (a) without requiring input from the electric actuator. 19. The method according to claim 18 wherein step (b) includes only actively actuating the flapper valve to move from the intermediate position to the open position, and including passively moving the flapper valve from the closed position to the intermediate position in response to exhaust flow being sufficient to overcome the biasing force. 20. The method according to claim 18 including actively moving the flapper valve from at least one of the closed position, the intermediate position, and the open position toward another of the closed position, the intermediate position, and the open position in response to an engine signal identifying an engine operating condition that comprises at least one of a number of operational engine cylinders and engine throttle/load conditions. 21. The method according to claim 18 including providing a coupling mechanism that couples the electric actuator to the shaft, and including driving the coupling mechanism to move the flapper valve to an open position when the electric actuator fails and when exhaust flow is sufficient to overcome the biasing force. 22. The exhaust valve assembly according to claim 1 wherein said shaft comprises a valve shaft and wherein said electric actuator includes an actuator shaft that is coupled to said valve shaft with said coupling mechanism, and wherein said coupling mechanism includes coupling structure that couples said valve shaft and said actuator shaft for rotation together and that uncouples said valve shaft and said actuator shaft from each other to allow said valve shaft to rotate independently of said actuator shaft. 23. The exhaust valve assembly according to claim 22 wherein said coupling structure comprises one of a coupling sleeve and a coupling disc. 24. The exhaust valve assembly according to claim 13 wherein said shaft comprises a valve shaft and wherein said electric actuator includes an actuator shaft that is coupled to said valve shaft with said coupling mechanism, and wherein said coupling mechanism includes coupling structure that couples said valve shaft and said actuator shaft for rotation together and that uncouples said valve shaft and said actuator shaft from each other to allow said valve shaft to rotate independently of said actuator shaft. 25. The exhaust valve assembly according to claim 24 wherein said coupling structure comprises one of a coupling sleeve and a coupling disc. 26. The method according to claim 18 wherein the shaft comprises a valve shaft and wherein the electric actuator includes an actuator shaft, and including coupling the actuator shaft to the valve shaft such that under one set of conditions the actuator and the valve shafts rotate together and under another set of conditions the actuator and the valve shafts are rotatable independently of each other. 27. The method according to claim 26 including providing the coupling mechanism with one of a coupling disc and a coupling sleeve.