Purifying apparatus of a particulate trap-type for collecting particulates in exhaust gas from an engine

摘要

An exhaust-gas purifying apparatus according to the present invention comprises an exhaust-gas filter for trapping particulates in exhaust gas from an engine, and a heating device located on the upper-course side of the filter, with respect to the flowing direction of the exhaust gas, the heating device including one or more conductive-ceramic heater elements, capable of heating and burning the particulates caught by the filter, and a heater case for holding the heater elements in position, so that the caught particulates are heated and burned by the heater elements when the flow resistance of the exhaust gas, flowing through the filter, is increased by the caught particulates, whereby the flow resistance is reduced. The heater element includes a fixed electrode portion, immovably fixed to the heater case, and a slidable electrode portion held slidably. An electrode member, fixed to the heater case, is brazed to the fixed electrode portion, and the heater element is bonded to the electrode member, so as to be clamped from both sides by solidified molten solder. The slidable electrode portion is supported by the heater case, for sliding motion in the direction of thermal deformation, so that the working life of the heater element is prolonged.