APPARATUS AND METHOD FOR AIR REMOVAL IN TILLAGE IMPLEMENTS USING THREE WAY VALVES

摘要

Air is removed from an hydraulic system for an agricultural implement supporting a plurality of gangs of disk blades extending generally laterally relative to a forward travel direction. The implement has carrier frames pivotally connected to wheel assemblies for controlling the height of the carrier frames relative to the ground through hydraulic actuators acting on the wheel assemblies. The hydraulic control unit enables independent and individual control of each actuator. An electronic control unit (ECU) controls three way valves associated with each actuator so that they may be operated in unison or individually. Hydraulic fluid is passed through the most remote actuator first and then actuators closer to the hydraulic control unit to remove air.

主权项

1. An agricultural implement spanning a lateral distance relative to a forward direction, said implement comprising:
a plurality of carrier frames, each for supporting a plurality of soil engaging tools; at least one supporting element carried by each carrier frame for variably positioning the carrier frame relative to the soil; an hydraulic actuator having a housing, in which a piston is displaceable and an output shaft connected thereto variably extending from said actuator housing and connected between said each supporting element and said respective carrier frame for varying the position of said respective carrier frame relative to the soil, said piston having a land to permit flow past the piston when the actuator output shaft is fully extended; a sensor determining the displacement of the output shaft relative to the actuator housing of each said actuator; a source of pressurized hydraulic fluid; an hydraulic control unit receiving said pressurized fluid and directing pressurized hydraulic fluid to said actuators to move said actuators independently in response to a signal input; an electronic control unit (ECU) establishing a desired input signal and comparing it to the signal from each said sensor to send a resultant signal to said hydraulic control unit for varying the position of each actuator output shaft to reach the signal input a pair of hydraulic lines extending from said hydraulic control unit for connection with said actuators; and valves controllable by said ECU for individually selectively one of bypassing and connecting each actuator to said hydraulic control unit, whereby said actuators may be controlled individually or in unison, said valves being connected by a common line, said ECU being controllable to fully extend the output shaft of one of the actuators and block other actuators from the hydraulic system while flowing hydraulic fluid through the valve common line and said one actuator past the land to therein to remove air, said ECU being controllable to subsequently also extend the next actuator fully and flowing through the next actuator and common line to remove air from said next actuator and, when air is removed from all subsequent actuators and common lines connecting the valves to provide a series connection therebetween.