CVT Shift Speed Control for Vibration Reduction

The patent changes the parameter of shift speed by introducing a shift speed limit value. When the accelerator pedal is detected to be off and engine speed is below a predetermined threshold, the control device limits the shift speed to a value lower than the normal shift speed. This parameter change suppresses hydraulic pressure vibration during shifting while still allowing the engine speed to be controlled at appropriate levels, thereby reducing vehicle vibration and driver discomfort without excessive engine braking force.

The patent implements dynamic adjustment of shift speed based on operating conditions. The control device determines whether to apply shift speed limitation based on real-time detection of accelerator pedal position and engine speed. When conditions indicate potential for hydraulic vibration (accelerator off and low engine speed), the shift speed is dynamically reduced. When conditions are favorable (accelerator on or high engine speed), normal shift speed is maintained. This dynamic approach optimizes shifting performance while suppressing hydraulic pressure vibration only when necessary.