| 摘要 |
<p>A hydraulic shovel, wherein a pipeline (71) allowing a pipeline (93) to communicate with a hydraulic tank (51) is installed in the pipeline (93). A restrictor (72) is installed in the pipeline (71) to form a restricted pipeline (7). If air is trapped between the hydraulic tank (51) and a hydraulic pump (52), the hydraulic pump (52) is driven to discharge the air from the restricted pipeline (7) to the hydraulic tank (51) to remove the air from the inside of a hydraulic circuit (5). Since a resistance by the restrictor (72) is increased when the air is removed, a hydraulic oil flows from a pilot pump (522) to a PPC valve (61). Since the air can be bled by a simple structure such as the restricted pipeline (7), the hydraulic oil from which the air is removed is supplied into a hydraulic cylinder (44) from the start. As a result, the responsiveness of the hydraulic cylinder (44) can be improved.</p> |
