Patent ID: 8052572

Claim:
A control device for an electronically controlled transmission disposed between a driving source and a driving wheel of a straddle-type vehicle that is capable of continuously changing a transmission ratio, wherein the straddle-type vehicle includes a shift-down permission switch that outputs a shift-down permission signal to the control device, a throttle operation member that operates a throttle, and a throttle operation member sensor that detects at least one of an operation amount of the throttle operation member and an operation speed of the throttle operation member, wherein the control device comprises: a transmission ratio control portion that controls the transmission ratio of the transmission according to a transmission ratio map; a shift mode selection portion that is capable of selecting, in accordance with a running state of the straddle-type vehicle, an AT mode in which the transmission ratio control portion continuously changes the transmission ratio of the transmission, the shift mode selection portion being configured such that, in the AT mode, the AT mode is shifted to a shift-down permission mode when the shift-down permission signal is output; and a shift-down operation amount computation portion that computes a shift-down operation amount, different from a shift-down transmission ratio stored in the transmission ratio map, based on a vehicle state of the straddle-type vehicle that includes at least one of the operation amount of the throttle operation member and the operation speed of the throttle operation member, wherein the transmission ratio control portion, in the shift-down permission mode, shifts down the transmission ratio of the transmission based on the shift-down operation amount when the throttle is operated.