EXHAUST PIPE TEMPERATURE CONTROL DEVICE FOR ENGINE

PROBLEM TO BE SOLVED: To restrain a temperature of an exhaust pipe from becoming an abnormally high temperature.SOLUTION: An exhaust pipe temperature control device 7 for an engine, includes: an exhaust gas temperature predicting section 77a for predicting a temperature of exhaust gas based on an operation state of the engine 1; an exhaust pipe temperature predicting section 77b for predicting a temperature of an exhaust pipe based on the exhaust gas temperature predicted by the exhaust gas temperature predicting section 77a, an exhaust pipe heat capacity coefficient, and a heat radiation coefficient based on wind velocity in an engine room; and a control section 77d for performing rotation speed increase control for increasing rotation speed of a cooling fan 5 when predicted exhaust pipe heat quantity related to the exhaust pipe temperature predicted by the exhaust pipe temperature predicting section 77b is larger than first prescribed heat quantity. 【課題】排気管の温度が異常高温になるのを抑制する。【解決手段】エンジンの排気管温度制御装置７は、エンジン１の運転状態に基づいて、排ガスの温度を予測する排ガス温度予測部７７ａと、排ガス温度予測部７７ａにより予測された排ガス温度と排気管熱容量係数とエンジンルーム内の風速に基づく放熱係数とに基づいて、排気管の温度を予測する排気管温度予測部７７ｂと、排気管温度予測部７７ｂにより予測された排気管温度に関連する予測排気管熱量が第１所定熱量よりも大きいときに、冷却ファン５の回転数を上げる回転数上昇制御を行う制御部７７ｄとを備えている。【選択図】図２