Waste gas braking butterfly valve for braking system of automobile and engineering machinery

The utility model discloses a waste gas braking butterfly valve for a braking system for an automobile and engineering machinery, which comprises a butterfly valve body, a butterfly valve sheet and a support frame assembly, wherein the butterfly valve sheet is arranged on the butterfly valve body through a butterfly valve sheet rotating shaft, the waste gas braking butterfly valve is provided with a waste gas operation cylinder, a gas inlet is arranged on a cylinder body of the waste gas operation cylinder, a piston is arranged in the cylinder body of the waste gas operation cylinder, the end part of the butterfly valve sheet rotating shaft extending out of the butterfly valve body is provided with a rotating arm assembly which is fastened and connected with the butterfly valve sheet rotating shaft, and the piston is connected with the rotating arm assembly through a piston rod. After the technical scheme is adopted, the waste gas braking butterfly valve is arranged in the braking system of the automobile or the engineering vehicle, the butterfly valve works when an engine conveys gas pressure into a braking pipeline, and the output power of the engine is regulated through controlling the exhaust speed (high speed or low speed) of the engine waste gas to realize the auxiliary braking effect.