| 摘要 |
PROBLEM TO BE SOLVED: To perform smooth auxiliary shift operation by a method wherein control of boosting is effected during connection of the shift clutch of the auxiliary transmission. SOLUTION: A main transmission 2 performs speed change of transmission of a reverser 1 and transmits it to an auxiliary gear shifter 3. The auxilary transmission 3 performs further speed change of transmission of a main speed change shifted by the main gear shifter 2 and transmits it to running wheels. In speed change operation of the auxiliary transmission 3, shift clutches 4-7 are provided at each auxiliary speed change and a power is disconnected once, and each time auxiliary speed change is effected, the shift clutches 4-7 are brought into engagement. Besides, during engagement of the shift clutches 4-7, a clutch connection pressure is gradually increased through control of boosting. This constitution absorbs torque during connection of the shift clutches 4-7 and effects smooth connection, reduces the occurrence of a shock during gear shift, and improves operability. |
