Heat Retention/Cooling Control Device for PM Filter Device

Abstract

Provided is a heat retention/cooling control device for a PM filter device, which controls the temperature of the outer periphery of the PM filter device to ensure an efficient burning in the PM filter device and prevents the influence of heat damage on the periphery of the PM filter device by effectively using moving air. An engine room and a cooling passage which are demarcated by a partition wall are provided in parallel in the front-back direction of an work machine, and an aftercooler, a cooling fan, and a PM filter device are provided in the cooling passage. When the exhaust temperature of exhaust gas is lower than a target temperature when PM is burned, the air volume of the cooling fan is controlled so as to decrease, thereby increasing the exhaust gas temperature. When the exhaust temperature of the exhaust gas is higher than the target temperature, the air volume of the cooling fan is controlled so as to increase, thereby enhancing the effect of cooling the outer periphery of the PM filter device.

1 . A heat retention/cooling control device for a PM filter device for reducing PM as particulate matters contained in an exhaust gas exhausted from a diesel engine mounted on an work machine comprising:
 a cooling passage disposed in parallel with an engine room configured in a front-back direction of the work machine and demarcated from the engine room via a partition wall;   an aftercooler disposed in the cooling passage for cooling air supercharged by a supercharger disposed in the engine room;   the PM filter device which is disposed on a downstream side of the aftercooler in the cooling passage and into which the exhaust gas from the engine is introduced;   a cooling fan which is disposed in the cooling passage, cools the aftercooler, and cools an outer periphery of the PM filter device by waste heat wind which has cooled the aftercooler;   a temperature sensor for detecting an exhaust gas temperature of the exhaust gas; and   a controller connected to the temperature sensor for controlling an amount of air of the cooling fan when the PM captured by a filter of the PM filter device is combusted,   wherein when the exhaust gas temperature detected by the temperature sensor is higher than a target temperature, the controller performs a control for increasing a cooling effect to the outer periphery of the PM filter device by increasing the amount of air from the cooling fan, and when the exhaust gas temperature detected by the temperature sensor is lower than the target temperature, the controller performs a control for assisting to increase and to retain a temperature in the outer periphery of the PM filter device by reducing the amount of air from the cooling fan.   
     
     
         2 . The heat retention/cooling control device for the PM filter device according to  claim 1 , wherein an exhaust pipe for introducing an exhaust gas exhausted from the engine into the PM filter device is disposed to receive wind from the cooling fan on an upstream side of the PM filter device.