Element for controlling exhaust line valves in heat engine of car, has overtravel spring absorbing overtravel of piston beyond its active position when specific temperature exceeds preset upper limit, and body attached to obturation unit

摘要

The element (1) has an actuator (45) including a movable hollow body (51) arranged longitudinally relative to a chamber (47). A main return spring (53) e.g. Belleville washer, for a piston (49) is interposed longitudinally between the chamber and the body. An overtravel spring (55) i.e. helicoid spring, is longitudinally interposed between the piston and the body, and absorbs overtravel of the piston beyond its active position when temperature of variable material exceeds a preset upper limit. The piston and the springs are placed in the body, which is attached to an obturation unit.