Hydraulic excavator and method for measuring the stroke of a hydraulic cylinder of a hydraulic excavator

摘要

A hydraulic excavator (1) comprises a base body portion, a movable portion, a hydraulic cylinder, a position sensor (10), a rotary encoder (20), and a control unit (30). The rotary encoder (20) comprises a light emitting unit (26), a light receiving unit (27) and a disk unit (25) having a plurality of passage portions (25a). The disk unit (25) is rotated in synchronization with the revolution of the movable portion relative to the base body portion. The light receiving unit (27) outputs a pulse signal based on the light that has passed through the plurality of passage portions (25a), wherein a rotation angle of the disk unit (25) is related to a rotation angle of the movable portion. The control unit (30) measures the stroke length of the hydraulic cylinder by correcting the deviation of the stroke length measured by the position sensor (10) based on the pulse signal output from the rotary encoder (20). In this way, a hydraulic excavator capable of accurately measuring a stroke length of a hydraulic cylinder driving a working tool and a method of measuring the stroke of the hydraulic cylinder of the hydraulic excavator can be obtained.