Hydraulic excavator

摘要

There is provided a hydraulic excavator in which invasion of a design surface by a work implement can be suppressed. A boom-lowering proportional solenoid valve is provided in a boom-lowering pilot conduit connected to a boom-lowering pilot port. A first pressure sensor detects a pressure generated in the boom-lowering pilot conduit between a control lever and the boom-lowering proportional solenoid valve. A controller controls an opening degree of the boom-lowering proportional solenoid valve based on the pressure detected by the first pressure sensor. The controller gently increases, from zero, a current value outputted to the boom-lowering proportional solenoid valve.

主权项

1. A hydraulic excavator, comprising:
a boom; a pilot switching valve for said boom having a boom-lowering pilot port and controlling operation of said boom; a boom-lowering pilot conduit connected to said boom-lowering pilot port; a boom-lowering proportional solenoid valve provided in said boom-lowering pilot conduit; a control lever operated by an operator; a first pressure sensor detecting a pressure generated in said boom-lowering pilot conduit between said control lever and said boom-lowering proportional solenoid valve; and a controller controlling an opening degree of said boom-lowering proportional solenoid valve based on the pressure detected by said first pressure sensor, wherein said controller gently increases, from zero, a current value outputted to said boom-lowering proportional solenoid valve.