Improved exhaust pipe for special vehicles

The utility model provides an improved exhaust pipe for special vehicles. An original exhaust pipe integrally formed is changed into an exhaust pipe consisting of an injection nozzle and a gradual expansion pipe which are molded in a split manner. The injection nozzle and the gradual expansion pipe which are molded in a split manner respectively form a straight pipe section and a gradual expansion pipe section, the front end of the injection nozzle extends into the gradual expansion pipe, and a gap is formed between the outer wall of the injection nozzle and the inner wall of the gradual expansion pipe. With the adoption of waste gas injection principle, external cold air is injected by utilizing the pressure of the exhaust gas of an engine in limited space, and the external cold air is mixed with the waste gas. The improved exhaust pipe for special vehicles overcomes the defects that the existing waste gas turbocharging diesel engine vehicle has low exhaust gas pressure, high exhaust gas temperature and remarkable infrared characteristics of the vehicle exhaust pipe and exhausted gas, so as to greatly improve the safety of special vehicles.