Construction machine

摘要

A regeneration apparatus for executing a regeneration process to an exhaust gas purifying apparatus and an engine control device that controls a rotational speed of an engine according to an instruction value by a rotational speed instruction apparatus are provided. When a directional control valve is in a neutral position, the engine control device controls the rotational speed of the engine to an automatic idle rotational speed (Nai) by an automatic idle selection unit regardless of the instruction value. However, when it is determined that the regeneration process of the exhaust gas purifying apparatus is executed in a state of controlling the rotational speed of the engine at the automatic idle rotational speed (Nai), the engine control device increases the rotational speed of the engine to a regeneration processing rotational speed (N1) higher than the automatic idle rotational speed (Nai).

主权项

1. A construction machine comprising:
an engine (10) as a prime mover; an exhaust gas purifying apparatus (16) that is provided in an exhaust side of said engine (10) to purify an exhaust gas; a regeneration apparatus (35, 36) for executing a regeneration process to said exhaust gas purifying apparatus (16); a hydraulic pump (13) that is driven by said engine (10) to suck operating oil in a tank and discharge pressurized oil; at least one hydraulic actuator (24) that is driven by the pressurized oil discharged from said hydraulic pump (13); a directional control valve (25) that is provided between said hydraulic actuator (24) and said hydraulic pump (13) to control supply of the pressurized oil to said hydraulic actuator (24); a rotational speed instruction apparatus (29) that instructs a rotational speed (N) of said engine (10); an automatic idle selection unit (30) configured to lower said rotational speed of said engine (10) to a predetermined automatic idle rotational speed (Nai); and an engine control device (34) that regularly controls said rotational speed (N) of said engine (10) according to an instruction value by said rotational speed instruction apparatus (29) and, when said directional control valve (25) is in a neutral position, controls said rotational speed (N) of said engine (10) to said automatic idle rotational speed (Nai) by said automatic idle selection unit (30) regardless of said instruction value, characterized in that: said engine control device (34) comprises: a regeneration determining unit configured to determine whether or not said regeneration process to said exhaust gas purifying apparatus (16) is executed by said regeneration apparatus (35, 36), at the time of controlling said rotational speed (N) of said engine (10) to said automatic idle rotational speed (Nai) by said automatic idle selection unit (30); and an engine rotational speed increasing unit configured to increase said rotational speed (N) of said engine (10) to a regeneration processing rotational speed (N1) higher than said automatic idle rotational speed (Nai), when it is determined that said regeneration process is executed by said regeneration determining unit.