Speed ratio controller and control method of toroidal continuously variable transmission

A speed ratio controller for use with a toroidal continuously variable transmission for a vehicle, to transmit an input torque from an engine to a drive wheel at an arbitrary speed ratio, said controller comprising:

• means for selecting either of an automatic operation mode and a manual operation mode of the transmission,
• means for designating a speed ratio grade in the manual operation mode,
• means for detecting the input torque of the transmission,
• means for detecting a real speed ratio of the transmission,
• means for calculating a target speed ratio according to the speed ratio grade designated by said speed ratio grade designating means,
• means for feedback controlling the speed ratio of the transmission such that said real speed ratio coincides with said target speed ratio, and
• means for preventing the speed ratio of the transmission from varying irrespective of said target speed ratio, after said input torque is varied.

A speed ratio controller for use with a toroidal continuously variable transmission for a vehicle, said transmission transmitting an input torque from an engine to a drive wheel at an arbitrary speed ratio, said controller comprising:

• a member for selecting either of an automatic operation mode and a manual operation mode of said transmission,
• a member for designating a speed ratio grade in the manual operation mode,
• a sensor for detecting the input torque of said transmission,
• a sensor for detecting a real speed ratio of said transmission, and
• a microprocessor programmed to:
• calculate a target speed ratio according to the speed ratio grade designated by said speed ratio grade designating member,
• feedback control the speed ratio of said transmission such that said real speed ratio coincides with said target speed ratio, and
• prevent the speed ratio of said transmission from varying irrespective of said target speed ratio, after said input torque is varied.

A method for controlling a speed ratio of a toroidal continuously variable transmission for a vehicle, said transmission transmitting an input torque from an engine to a drive wheel at an arbitrary speed ratio, said transmission comprising a member for selecting either of an automatic operation mode and a manual operation mode of said transmission, and a member for designating a speed ratio grade in the manual operation mode, said method comprising:

• detecting the input torque of said transmission,
• detecting a real speed ratio of said transmission,
• calculating a target speed ratio according to the speed ratio grade designated by said speed ratio grade designating member,
• feedback controlling the speed ratio of said transmission such that said real speed ratio coincides with said target speed ratio, and
• preventing the speed ratio of said transmission from varying irrespective of said target speed ratio, after said input torque is varied.