| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of shock and keep continuous torque transmission by keeping continuous engine rotation at the time of switching operation modes. SOLUTION: A hydromechanical transmission is so structured that a mechanical transmission(MT) is arranged between an input shaft and an output shaft, and a hydrostatic transmission(HST) is parallelly arranged for dividing operation mode into three i.e., the first to third. In order to switch a first mode where a first clutch mechanism 10 only is connected to a second mode where a second clutch mechanism 11 only is connected, first when the second clutch mechanism 11 is engaged, that is switching is started, a swash plate angle of a variable swash plate of a hydraulic pump is set so as to engage at a swash plate angleθp1 corrected by a lowered rate of volumetric efficiency due to torque transmission relative to a swash angleθp0 at the time of volumetric efficiency 1.0. Secondly the swash plate angle is corrected to a degree inversely in respect to an inversed torque after switching. The first clutch mechanism 10 is separated, that is, switching is completed. |
