Construction machine

Abstract

There is provided a construction machine capable of increasing the intervals for replacing a hydraulic fluid. A hydraulic excavator includes an additive tank for storing an additive, an additive supply line for supplying the additive from the additive tank to a hydraulic fluid tank, an on-off valve disposed on the additive supply line and switchable between a closed state and an open state, a degree-of-oxidation sensor for sensing the degree to which the hydraulic fluid has been oxidized, and a controller. The controller performs control for reporting that the on-off valve is to switch into the open state or control for switching the on-off valve into the open state when the rate of change in the degree to which the hydraulic fluid has been oxidized is equal to or higher than a predetermined value. The controller performs control for reporting that the on-off valve is to switch into the open state or control for switching the on-off valve into the open state when the machine uptime from the time of replacement of the hydraulic fluid or the machine uptime from the time of switching of the on-off valve from the open state into the closed state is equal to or longer than a predetermined value.