DUNN, JAMES T.,LEVERICK, GRAHAM M.,LYONS, RUSSELL G.,SHEARER, BRUCE R.
申请号：
CA3003019
公开号：
CA3003019A1
申请日:
2017.03.30
申请国别(地区):
CA
年份:
2017
代理人:
摘要：
In a crop harvesting machine there is provided a pair of hydraulic floatcylinders for a header relative to a vehicle, where a float pressure to thecylinders isdirectly controlled by an electronic control supplying a variable controlsignal to aPPRR valve arrangement to maintain the float pressure at a predeterminedvalue.At the set pressure a predetermined lifting force is provided to the header. Aposition sensor is used to generate an indication of movement and/oracceleration.The electronic control is arranged, in response to changes in the sensorsignal, totemporarily change the control signal to vary the lifting force and thuschange thedynamic response of the hydraulic float cylinder. In order to reduce staticfriction sothat the system can react quickly, an arrangement is provided for causingrelativereciprocating movement in an alternating wave pattern between the piston andcylinder.
