Servo operation apparatus for a transmission

Abstract

A servo operation apparatus for a transmission comprising an input shaft to which the shift-change operation force is mechanically transmitted from a shift lever, a servo unit for boosting the shift-change operation force by feeding a working fluid, and a valve device which feeds the working fluid to, or drains the working fluid from, the servo unit depending upon the shift-change operation of the shift lever, wherein provision is made of an working fluid feed control means which feeds the working fluid in such a manner that the pressure of the working fluid in the servo unit is raised with a steep gradient in the former half until a predetermined initially raised pressure value is reached and, thereafter, is raised in the latter half with a gradient less steep than that of said former half. Or, when the apparatus is equipped with a reaction device which imparts reaction to the shift-change operation force transmitted to the input shaft by utilizing the working fluid, provision is made of a working fluid feed control means which feeds the working fluid in such a manner that the rise of the pressure of the working fluid in the reaction device is delayed behind the rise of the pressure of the working fluid in the servo unit.