Patent ID: 6149547
Filing Date: 2000-11-21
Classification: F16H,Y10T

Abstract:
A gearshift control apparatus for an automatic transmission having a release side hydraulic control mechanism which controls a hydraulic pressure of a release side clutch, and an engagement side hydraulic control mechanism which controls a hydraulic pressure of an engagement side clutch, wherein a torque capacity of the release side clutch is gradually lowered by the release side hydraulic control mechanism, and a torque capacity of the engagement side clutch is gradually raised by the engagement side hydraulic control mechanism, so that the release side clutch and the engagement side clutch are changed-over to effect a clutch-to-clutch gearshift, comprising:control means for issuing first and second hydraulic pressure commands for the hydraulic pressure of said engagement side clutch to said engagement side hydraulic control mechanism; whereinsaid control means issues said first hydraulic pressure command for a predetermined time period for adjusting a timing of the changeover between said clutches, and thereafter, issues said second hydraulic pressure command as a constant level command until the inertia phase begins for adjusting the torque capacity of said engagement side clutch at said changeover,wherein said control means alters at least one of a command value of the fist hydraulic pressure command and said predetermined time, thereby to adjust the timing of said changeover between said clutches,further comprising means for detecting a time period having lapsed since a timing at which a release command was issued to said engagement side clutch in a previous gearshift; wherein said control means alters at least one of the command value of said first hydraulic pressure command and said predetermined time on the basis of the time period having lapsed since the timing at which the release command was issued to said engagement side clutch in the previous gearshift.