| 摘要 |
PURPOSE:To prevent deterioration of durability in a driving gear deriving from vibration, in a butterfly valve used for the exhaust brake in an automobile, by driving the valve with a crank and providing a stopper fro locking rotary motion of the crank. CONSTITUTION:A diaphragm type actuator 1 is used for driving a butterfly valve. When the butterfly valve is not driven, a diaphragm 1d is locked between a side plate 1c and push plate 1e by urging force of a spring 1g. While cranks 2, 3 are integrally locked by a branch part 4b of a spring 4. When the valve is in a driven state, each member from a rod 1f to the cranks 2, 3 is integrally pressed to a stopper 3c. In this way, vibration of each member due to looseness can be eliminated, and abnormal friction is not caused in use even for a long period. |
