Patent ID: 8206264

Claim:
A load control system for a work vehicle comprising: set rotation speed detection means for detecting a set rotation speed of an engine of the work vehicle; actual rotation speed detection means that senses an actual rotation speed of the engine; continuously variable speed change device that receives power from the engine of the work vehicle; speed change position detecting means for detecting a speed change operating position of the continuously variable speed change device; operating means for speed-shifting the continuously variable speed change device; and control means for controlling the operation of the operating means with the set rotation speed of the engine being unchanged, the control means including: a drop amount calculating unit for calculating a drop amount of the actual engine rotation speed from the set rotation speed based on the detected information from the set rotation speed detection means and the actual rotation speed detection means; a data table for storing a correlation data set that defines operating positions of the continuously variable speed change device relative to the drop amount; wherein the data table includes a first region and a second region and the drop amount is larger in the second region than in the first region; wherein the correlation data is set such that a change rate of the operating position relative to the drop amount in the second region becomes smaller than a change rate of the operating position relative to the drop amount in the first region; and wherein the second region has a stabilizing point where the actual rotation speed of the engine does not fall due to a running load.