Pumping loss controlling system

A pumping loss controlling system belongs to the technical field of internal combustion engines comprises an engine air inlet pipe, a supercharger, an engine, an engine exhaust pipe, a turbine, a connecting pipe, an adjusting cavity, a rotating shaft, a rotating plate, a control cavity, an inner pipe, a spring, a rotator and a stressed plate. The adjusting cavity and the control cavity are coaxially connected through the rotating shaft, the stressed plate is connected with a left wall of a fixed body through a spring, one end of a second connecting pipe is communicated with an inner cavity of the control cavity, and the other end of the second connecting pipe is connected with the engine exhaust pipe between the engine and the turbine. In the pumping loss controlling system, when the engine runs on the high-speed working conditions, the front exhaust capacity of the turbine is large, the pumping loss is small, and the oil consumption is low; when the engine runs on the low-speed working conditions, the front exhaust capacity of the turbine is small, pulse energy can be fully utilized, and the oil consumption is low. The pumping loss controlling system is reasonable in design, simple in structure and suitable for optimized design of turbocharged engine exhaust systems.