| 摘要 |
PROBLEM TO BE SOLVED: To surely prevent engine stop when a high hydraulic pressure load is suddenly applied in a working vehicle such as a wheel loader. SOLUTION: If an operator suddenly operates an operation lever for a loader in a rise direction while operating a steering handle, engine torque rise can not catch up with quick hydraulic pressure load rise (occurrence of time delay) and actual rotation speed Nr of the engine 1 goes down to a threshold Nc or lower. If a controller judges that the engine rotation speed detected by an engine rotation speed detection sensor goes down to the threshold Nc or lower, the controller executes control for reducing absorbing torque of a variable displacement type hydraulic pump. Consequently, hydraulic pressure load shifts to a low hydraulic pressure load line shown as Tp2. Since hydraulic pressure load changes to the low hydraulic pressure load Tp2 from high hydraulic pressure load Tp1, present time engine torque gets excess to the low hydraulic pressure load Tp2, and returns onto a regulation line FL as shown by C2. COPYRIGHT: (C)2009,JPO&INPIT
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