A modular hoist drum is disclosed for use with a power shovel. The modular hoist drum may have a first outer body, a second outer body, and an anchor body that are hollow and generally cylindrical. The anchor body is connected between the first outer body and the second outer body. The anchor body may include an internal anchor configured to receive a ferrule.

A construction machine is provided. If the rotational speed of a prime mover is set lower than a rated rotational speed and the delivery rate of a hydraulic pump is lowered, the construction machine can prevent deterioration of the operability in slow speed operation works by keeping wide a lever operation range in which the rate of flow supplied to a hydraulic actuator is variable. A center bypass control valve (2) is arranged downstream of a plurality of directional flow control valves (1, 20, 21) in a center bypass line (12), and if an engine rotational speed (N) detected by a rotational speed sensor (19) is lower than a rated rotational speed (Nmax), a controller (10) calculates a combined opening area obtained by combining opening areas of the plurality of directional flow control valves in the center bypass line based on operation pilot pressures (Pp1, Pp3 to Pp6) detected by pressure sensors (7, 25, 26, 28, 29) and controls the center bypass control valve such that an opening area of the center bypass control valve becomes smaller than the combined opening area.

A construction machine is provided. If the rotational speed of a prime mover is set lower than a rated rotational speed and the delivery rate of a hydraulic pump is lowered, the construction machine can prevent deterioration of the operability in slow speed operation works by keeping wide a lever operation range in which the rate of flow supplied to a hydraulic actuator is variable. A center bypass control valve (2) is arranged downstream of a plurality of directional flow control valves (1, 20, 21) in a center bypass line (12), and if an engine rotational speed (N) detected by a rotational speed sensor (19) is lower than a rated rotational speed (Nmax), a controller (10) calculates a combined opening area obtained by combining opening areas of the plurality of directional flow control valves in the center bypass line based on operation pilot pressures (Pp1, Pp3 to Pp6) detected by pressure sensors (7, 25, 26, 28, 29) and controls the center bypass control valve such that an opening area of the center bypass control valve becomes smaller than the combined opening area.

A modular hoist drum is disclosed for use with a power shovel. The modular hoist drum may have a first outer body, a second outer body, and an anchor body that are hollow and generally cylindrical. The anchor body is connected between the first outer body and the second outer body. The anchor body may include an internal anchor configured to receive a ferrule.