公开(公告)号：US4492080A

公开(公告)日：1985-01-08

申请号：US590675

申请日：1984-02-21

Applicant: Robert E. Yapp ,  John D. Smith

Inventor： Robert E. Yapp ,  John D. Smith

IPC: A01B63/00 ,  A01B63/10 ,  A01B63/111 ,  F15B9/08

CPC classification number: A01B63/1013 ,  A01B63/1117

Abstract: A tractor hydraulic control system of the kind comprising a power lift with a hydraulic actuator (12) and a main control valve (17) controlling the supply of fluid from a pump (19) to the actuator, the system including selector valve means (50) interconnected with the main control valve (17) and movable between a first position in which flow to and from the actuator (12) occurs via the selector valve means under the control of the main control valve and the associated system control mechanism (28) and a second position in which the actuator is hydraulically locked in a given position and an external services outlet (51) is placed in communication with the pump. Linkage means (60,61,62) operatively connects the selector valve means (50) and the system control mechanism (28) to condition the main control valve (17) to cause the pump (19) to supply fluid to the external service outlet (51) via the selector valve means on movement of the selector valve means to the second position. Preferably, the main control valve (17) is biased towards a position in which the pump delivery its maximum output flow to the selector valve means and movement of the selector valve means to its second position is arranged to disconnect the control mechanism from the main control valve.

Abstract translation: 一种拖拉机液压控制系统，包括具有液压致动器（12）的动力升降器和控制从泵（19）向致动器供给流体的主控制阀（17），该系统包括选择阀装置（50 ）与所述主控制阀（17）相互连接，并且可在主控制阀和相关的系统控制机构（28）的控制下经由所述选择阀装置在所述第一位置与所述致动器（12）之间流动和流动的第一位置之间移动; 以及第二位置，其中致动器被液压地锁定在给定位置，并且外部服务出口（51）被放置成与泵连通。 连接装置（60,61,62）可操作地连接选择阀装置（50）和系统控制机构（28）以调节主控制阀（17），以使泵（19）向外部服务出口 （51）在选择阀装置移动到第二位置时经由选择阀装置。 优选地，主控制阀（17）被偏压到泵输送到其选择阀装置的最大输出流量并且选择阀装置移动到其第二位置的位置，以将控制机构与主控制器 阀。