Patent ID: 8858151
Filing Date: 2014-10-14
Classification: E02F

Abstract:
1. A method of operating a machine including ground engaging propulsion elements and a hydraulically actuated implement system having a linkage and an implement, the method comprising the steps of: fluidly connecting a hydraulic actuator for the linkage to an inlet passage via a first valve conveying hydraulic fluid to the hydraulic actuator at an outlet pressure of a hydraulic pump of the implement system; receiving via an electronic control unit an implement down force control command; adjusting the pressure of hydraulic fluid in the hydraulic actuator from the pump outlet pressure to an adjusted pressure via the electronic control unit at least in part by opening another fluid connection from the hydraulic actuator to the inlet passage via a second valve, responsive to the command, and moving the first valve to a neutral position such that the corresponding fluid connection is shut; resting the implement upon a substrate below the machine such that the implement applies a controlled down force to the substrate which is based on the adjusted pressure and is less than a quiescent down force of the hydraulically actuated implement system; the step of adjusting further including a step of conveying hydraulic fluid to the hydraulic actuator from the inlet passage via the second valve such that a pressure of the hydraulic fluid is reduced by the second valve from the pump outlet pressure in the inlet passage to the adjusted pressure; the step of conveying hydraulic fluid further including conveying the hydraulic fluid from the hydraulic pump to a head-side chamber of the hydraulic actuator by way of a reducing valve that includes the second valve; electronically reading stored implement type data, and stored valve state data; and moving the reducing valve responsive to the implement type data and the valve state data.