Patent attributes
A shovel that performs excavation in accordance with a complex excavation operation including an arm or bucket closing operation and a boom raising operation includes an excavation operation detection part, a position detection part, a maximum allowable pressure calculation part, and a boom cylinder pressure control part. The excavation operation detection part detects that the complex excavation operation has been performed. The position detection part detects the position of the shovel. The maximum allowable pressure calculation part calculates the pressure of the contraction-side oil chamber of a boom cylinder corresponding to an excavation reaction force at a time when the shovel is lifted by the excavation reaction force as a maximum allowable pressure, based on the position of the shovel. The boom cylinder pressure control part controls the pressure of the contraction-side oil chamber not to exceed the maximum allowable pressure when the complex excavation operation is performed.
