Patent ID: 8423247

Claim:
A speed change control system for industrial vehicle, comprising: a speed ratio detecting unit that detects a speed ratio of speeds of an input shaft and of an output shaft of a torque converter; a speed changer that includes a plurality of speed stages, shifts up a speed stage of a transmission to a 2 nd speed when a traveling load lowers to increase the detected speed ratio to a first predetermined value or greater while traveling at a 1 st speed, and shifts down the speed stage of the transmission to the 1 st speed when a traveling load rises to decrease the detected speed ratio to a second predetermined value or lower while traveling at the 2 nd speed; a braking detection unit that detects an operation of a braking device for traveling; and a downshift limit unit that permits a downshift to the 1st speed by the speed changer when the traveling load rises to decrease the speed ratio to the second predetermined value or lower while traveling at the 2 nd speed if a non-operation of the braking device is detected by the braking detection unit, and does not permit the downshift to the 1 st speed by the speed changer but maintains the 2 nd speed even when the traveling load rises to decrease the speed ratio to the second predetermined value or lower while traveling at the 2 nd speed if an operation of the braking device is detected.