| 摘要 |
<p>PURPOSE:To raise the capability of climbing slope by a method in which a port relief valve is used as a relief valve to control the pressure of working oil in cylinders, and the relief pressure is set up to a drive pressure with a power margin for the allowable confining pressure of the cylinders. CONSTITUTION:The relief pressures of port relief valves 23a and 23b are set up to drive pressures with a power margin for the allowable confining pressure of the cylinders 6a, 7a, and 8a of arm, boom, and bucket respectively. Working oil sent under pressure by a pump P1 is controlled for its pressure by a main relief valve 27a and supplied through control valves 12, 13a, and 14 to the cylinder 7a, a left side traveling motor 10a, and a slewing motor 11. The working oil sent under pressure by a pump P3 is controlled for its pressure by a main relief valve 27b and supplied through control valves 15, 16, and 13b to the cylinder 6a, the cylinder 8a, and the right side traveling motor 10b. The working oil is further supplied to the cylinders 6a-8a by being controlled for pressures by valves 23a and 23b according to the drive pressure of each cylinder.</p> |
