Process for controlling a CVT installed in the power train of a motor vehicle

• US 6,436,003 B1
• Filed: 08/07/2000
• Issued: 08/20/2002
• Est. Priority Date: 08/24/1999
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Becker, Gernot, Kleila, Hans
• Primary Examiner(s): Marmor, Charles A
• Assistant Examiner(s): PANG, ROGER L
• Application Number:
  US09/633,385
• Time in Patent Office: 743 Days
• Field of Search: 477/43, 477/44, 477/46, 477/120, 477/121, 477/125
• US Class Current: 477/43
• CPC Class Codes: F16H 2059/183 Rate of change of accelerator position, i.e. pedal or throttle change gradient
• CPC Class Codes: F16H 2061/6611 Control to achieve a particular driver perception, e.g. for generating a shift shock sensation
• CPC Class Codes: F16H 2061/6615 Imitating a stepped transmissions
• CPC Class Codes: F16H 59/40 Output shaft speed
• CPC Class Codes: F16H 61/66259 using electrical or electronical sensing or control means

Abstract

The invention concerns a process for controlling a CVT in a motor vehicle. In order to avoid an uncomfortable excitation of a transmission ratio change of the CVT when the driving speed is constant it is proposed that in the case of small accelerator pedal changes (<a) and in the case of changes in driving speed (S) occurring within a calibrated range (S1<S<S2) the transmission ratio of the CVT be held constant.

Claims

1. Process for controlling a CVT (continuously variable transmission) installed in a drive train of a motor vehicle between a drive engine and a drive axle with a driven primary disk and a secondary disk of which at least one is variable in its active diameter and which together are surrounded by a surrounding organ for transmitting a torque, an electronic control device registering and monitoring the rpm signals of the primary disk and secondary disk, and actuators for adjusting the effective diameter of the primary and/or secondary disk and with it the transmission ratio of the CVT as a function of these rpm and of at least the position of an accelerator pedal, characterized by the following steps:

in the case of a change in the accelerator pedal position it checks whether this change is within a value (a) relevant for a driving behavior or lies above it (1), in which case only when the value is above it does it intervene in the regulation of the transmission ratio of the CVT in the form of a change in transmission ratio (4);

if it is found that the change in the accelerator pedal position is below a value (a) relevant for the driving behavior, it checks whether a driving speed (S) has changed to above a calibrated range around the current driving speed or remains within this calibrated range (S1<

S<

S2) (2) in which case only upon the recognition of a change in driving speed outside of the calibrated range (S1<

S<

S2) does it intervene immediately in the regulation of the transmission ratio in the form to a change in the transmission ratio (4) of the CVT;

if it is found that the change in the driving speed remains within the calibrated range (S1<

S<

S2) it does not intervene in the regulation of the CVT in the form of a transmission ratio change, and the existing transmission ratio remains constant (3).

2. Process as in claim 1, characterized by the fact that the calibrated range (S1<

S<

S2) varies in magnitude as a function of the actual driving speed (S).

3. Process as in claim 2, characterized by the fact that the calibrated range (S1<

S<

S2) becomes greater with increasing driving speed (S).