| 摘要 |
PURPOSE:To reduce the generation of a gear shifting shock at an upward and a downward slope and to improve amenity by providing a boosting means to control boosting of the feed working pressure of a working oil feed means for feeding working oil to a hydraulic actuator when a detecting inclination angle exceeds a set value. CONSTITUTION:Since, when gear shifting operation is effected at an upward slope or during traction of a truck or at a muddy ground or when gear shifting operation is performed at a downward slope, the working pressure of a hydraulic actuator for gear shifting operation is increased, the hydraulic actuator effects slide operation of shift gears S1 and S3 of gear shifting devices A and D to gear the shift gears with a transmission gear. As noted above, by performing operation to engage the hydraulic clutch B through slide operation of the shift gears S1 and S3 before a machine body is widely decelerated during gear shifting operation at an upward slope, the occurrence of rapid acceleration phenomenon is suppressed to reduce the generation of gear shifting shock. |
