SWING TYPE HYDRAULIC EXCAVATOR

An upper cover (8) has a curved portion (45) formed in its end portion on the side near a work front (5) for avoiding interference with the work front (5). The curved portion (45) comprises a recessed surface (45A) having a center axis aligned with the axis (m) of a vertical pin of a swing post (4), a first stepped portion (45B) provided at a lower end of the recessed surface (45A) and defining a substantially constant gap with respect to a locus drawn by a rear projecting portion (4A) of the swing post (4) when the work front (5) is swung, and a second stepped portion (45C) provided in an intermediate portion of the recessed surface (45A) in the direction of height thereof and having a substantially horizontal surface (45C1) for assuring a foothold. The recessed surface (45A) is configured to extend along a locus drawn by a back surface of the boom (16) when the work front (5) is swung in its minimum-turn posture, while defining a gap with respect to the locus. The first stepped portion (45) has a substantially vertical curved surface (45B1) formed in continuation with the lower end of the recessed surface (45A) and defining a substantially constant gap with respect to the locus drawn by the rear projecting portion (4A) of the swing post (4) when the work front (5) is swung, and a substantially horizontal surface (45B2) formed in continuation with adjacent the curved surface (45B1) on the side near the work front (5) and defining a substantially constant gap with respect to a locus drawn by a lower end of the rear projecting portion (4A) of the swing post (4) when the work front (5) is swung.