Power on skip downshift using three clutches

Details Power on skip downshift using three clutches Power on skip downshift using three clutches

1998-08-10

1999-10-05

Ta, Khoi Q.

Interrelated power delivery controls, including engine control

Transmission control

Transmission controlled by engine

477144, 477 80, F16H 6104, F16H 6116

Patent

active

059614218

ABSTRACT:
In an automatic transmission of the type wherein a stage intermediate between a higher speed stage and a lower speed stage is achieved through a clutch-to-clutch operation, a power-ON skip downshift is executed via the intermediate stage. First, when the skip downshift has been judged, the hydraulic pressure of the clutch (C4) of the higher speed stage is lowered. Next, when the input speed(r.p.m.) of the transmission have reached the synchronous r.p.m. (SS3) of the intermediate stage, the hydraulic pressure (P3) of the clutch (C3) of the intermediate stage is raised and adjusted so that the rise rate of the input r.p.m. may become a specific value d/dt(NT1). When the input r.p.m. have exceeded the synchronous r.p.m. (SS2) of the lower speed stage, the hydraulic pressure of the intermediate-stage clutch (C3) is adjusted so that the input r.p.m. may keep specific r.p.m. higher than the synchronous r.p.m. (SS2) of the lower speed stage, and simultaneously, the hydraulic pressure of the clutch (C2) of the lower speed stage is gradually raised. Finally, when a predetermined time period has lapsed since the start of the operation of raising the hydraulic pressure (P2) of the clutch (C2), the hydraulic pressure (P3) of the clutch (C3) is gradually lowered till the end of the gearshift.

REFERENCES:
patent: 4671139 (1987-06-01), Downs et al.
patent: 5647819 (1997-07-01), Fujita et al.
patent: 5697864 (1997-12-01), Watanabe

Affiliated with

Also associated with

Rating

Power on skip downshift using three clutches does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Power on skip downshift using three clutches, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Power on skip downshift using three clutches will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1163947