Shift control device for vehicular continuously variable transmission

A shift control device for a vehicular continuously variable transmission, including shift mode switching means for determining as to whether an accelerator operation amount being an acceleration demand value by a driver exceeds a predetermined acceleration demand determining value and switching a shift mode from a normal shift mode in which an input-shaft rotation speed is controlled in accordance with a predetermined shifting condition in terms of parameters including the accelerator operation amount and a vehicle speed to an acceleration shift mode when the accelerator operation amount exceeds the predetermined acceleration demand determining value,

• the shift control device comprising:
• the acceleration shift mode performing a shift control such that an input shaft rotation speed upon switching from the normal shift mode to the acceleration shift mode is caused to increase up at once to a predetermined initial value smaller than a value calculated in accordance with the shifting condition in the normal shift mode and subsequently, the input shaft rotation speed is increased in proportion to increase of a vehicle speed by adding a vehicle-speed-variation correction value NINTLSPD calculated by multiplying a variation amount ΔV of the vehicle speed and a predetermined correction value α,
• the acceleration demand determining value being determined depending on a road surface gradient being a running resistance of a vehicle such that the shift mode is more difficult to be switched to the acceleration shift mode when the road surface gradient is larger than when the road surface gradient is smaller, and
• during the acceleration shift mode, the correction coefficient α being determined such that as the road surface gradient becomes larger, the value of the correction coefficient α becomes larger, such that the shift control is performed so as to cause the input-shaft rotation speed to be higher when the road surface gradient is larger than when the road surface gradient is smaller.