MACHINE BODY AND WORKING MACHINE

摘要

Provided is a space-saving inexpensive machine which is capable of cooling a part necessary to be cooled of an exhaust gas treatment device. The exhaust gas treatment device (22) includes an injector (29) which injects urea water as a liquid reducing agent supplied through a urea water hose (34) serving as a reducing agent supply pipe from a reducing agent supply source, a NOx sensor (30) which detects a concentration of nitrogen oxide in exhaust gas, and an air duct (35) including an inlet side opening (42) and an outlet side opening (53) that cool at lease either one of the urea water in the urea water hose (34), the NOx sensor (30) or the injector (29) with cooling air introduced from outside of the machine room (19). A ventilation opening (26) opened at the outside of the machine room (19) is communicated with the inlet side opening (42) of the air duct (35), and air in the air duct (35) is forcibly exhausted from the outlet side opening(53) of the air duct (35) with the use of negative pressure formed in a circumference of the exhaust gas flow by an ejector (51) arranged in an exhaust pipe passage (24).