| 摘要 |
<P>PROBLEM TO BE SOLVED: To effectively prevent damage to a transmission including an HST due to an excessive running load while preventing cost escalation as much as possible. <P>SOLUTION: A control device, in which a relation between an actual gear ratio and load torque, and a protection torque value for protecting the transmission including the HST are stored for each of two or more gear ratios, has a vehicle speed control mode in which HST operation control is performed using a set gear ratio as a target gear ratio, and a load control mode performed when a load torque value, which is estimated from the actual gear ratio calculated by signals from the input side sensor and output side sensor of the HST and the relation between the actual gear ratio and load torque in the current target gear ratio, exceeds the protection torque value in the current target gear ratio. In the load control mode, the HST operation control is performed using a lower speed gear ratio than the current target gear ratio as the target gear ratio regardless of the operation state of a shift operation member. <P>COPYRIGHT: (C)2012,JPO&INPIT |
