초록 ▼

An infinitely variable transmission has a gear neutral (GN) point and serves as an output member by torque circulation. When a pulley ratio thereof is within a predetermined range from the GN point, a coasting state occurs which may hinder smooth torque transmission based on the transmission efficie

An infinitely variable transmission has a gear neutral (GN) point and serves as an output member by torque circulation. When a pulley ratio thereof is within a predetermined range from the GN point, a coasting state occurs which may hinder smooth torque transmission based on the transmission efficiency and generate a great engine braking effect (failure in the transmission resulting from the coasting state) based on a large gear ratio. When the pulley ratio assumes a predetermined value that may cause failure in transmission resulting from the coasting state, upon release of the accelerator pedal, an electronic throttle system performs control such that the engine outputs a predetermined torque. Thus a positive driving state is always established. In this state, the continuously variable transmission (CVT) is shifted in the upshift direction to escape rapidly from a range defined by the pulley ratio of the predetermined value.

대표청구항 ▼

[ What is claimed is:] [1.] An infinitely variable transmission for use with an output shaft of a power source and wheels, comprising:an input shaft connected to the output shaft of the power source;an output member connected to the wheels;a continuously variable transmission having a first rotating

[ What is claimed is:] [1.] An infinitely variable transmission for use with an output shaft of a power source and wheels, comprising:an input shaft connected to the output shaft of the power source;an output member connected to the wheels;a continuously variable transmission having a first rotating member connected to said input shaft, a second rotating member, and speed-change operating means for changing rotational ratio between the first rotating member and the second rotating member;a planetary gear set having at least first, second and third rotating elements, said first, second and third rotating elements connected to said input shaft, said second rotating member and said output member respectively, so as to change a torque transmitting direction between the first rotating member and the second rotating member based on changes in the rotational ratio of said continuously variable transmission, and to change a torque transmitting direction for transmitting output torque of said output member; andpower control means for controlling output of said power source;wherein said power control means establishes a positive driving state such that a torque is transmitted from said power source to said wheels, when the rotational ratio of said continuously variable transmission is within a first predetermined range from a neutral position in which rotation of said output member is zero wherein an engine braking effect is generated due to a failure in power transmission resulting from a coasting state based on a large gear ratio in the coasting state, and if the output torque of the output shaft of said power source is less than a second predetermined value that establishes a negative driving state in which torque is transmitted from the wheels to said power source.