SPEED-CHANGE CONTROLLER FOR WORKING VEHICLE

摘要

PROBLEM TO BE SOLVED: To provide a speed-change controller for a working vehicle easily composable to change a gear change range of traveling vehicle speed in response to conditions and carry out drive control of an HST stepless speed change drive. SOLUTION: The speed-change controller for a working vehicle is provided with an HST transmission mechanism operated by a trunnion shaft, and a sub transmission mechanism operated by a sub speed change selector lever. It is composed of a control part carrying out drive control of the trunnion shaft of the HST transmission mechanism to a target vehicle speed set in response to both selection positions of an advance/reverse lever for advance/reverse selection, and a main speed change lever for vehicle speed selection. The control part carries out drive control of the trunnion shaft in a limit of a separately determined vehicle speed setting range corresponding to the selection position of the sub speed change selector lever. COPYRIGHT: (C)2009,JPO&INPIT