Machine Body and Working Machine

Abstract

An injector injects urea water as a liquid reducing agent; a NOx sensor detects concentration of nitrogen oxide in exhaust gas; and an air duct including an inlet side opening and outlet side opening cools at least either one of urea water in urea water hose, NOx sensor or injector with cooling air introduced from outside of the machine room. A ventilation opening at the outside of the machine room communicates with the inlet side opening of the air duct using negative pressure formed in a circumference of exhaust gas flow by an ejector arranged in an exhaust pipe passage.

1 . A machine body comprising:
 a machine room;   an engine installed in the machine room;   an exhaust line through which exhaust gas from the engine is discharged;   an exhaust gas cleaning apparatus provided in the exhaust line to execute a reducing process on nitrogen oxide in exhaust gas; and   a reducing agent supply apparatus that supplies a liquid reducing agent to the exhaust gas cleaning apparatus through a reducing agent supply pipe,   wherein the exhaust gas cleaning apparatus includes:   an injector that injects the liquid reducing agent supplied by the reducing agent supply apparatus through the reducing agent supply pipe;   a nitrogen oxide sensor that detects a concentration of the nitrogen oxide in the exhaust gas;   an air passage body installed so as to surround at least one of a part of the reducing agent supply pipe, a part of the nitrogen oxide sensor, and a part of the injector to allow at least one of the liquid reducing agent in the reducing agent supply pipe, the nitrogen oxide sensor, and the injector to be cooled using cooling air taken from an outside of the machine room, the air passage body including an inlet side opening and an outlet side opening;   an outside air intake port which communicates with the inlet side opening of the air passage body and which opens to the outside of the machine room; and   an ejector provided in the exhaust line to forcibly discharge air in the air passage body through the outlet side opening of the air passage body by utilizing a negative pressure formed around an exhaust gas flow.   
     
     
         2 . A working machine comprising:
 the machine body according to  claim 1 ; and   a working apparatus mounted on the machine body.