PURPOSE: To maintain a target cargo handling amount at all times by detecting the driving hydraulic oil of a hydraulic motor to perform circulating bucket driving and controlling the moving feed speed of an unloader by a proportional and integrating calculation so that a target hydraulic pressure can be obtained.
CONSTITUTION: A hydraulic pressure detector 20 to detect the pressure load of a hydraulic motor 14 is provided on the hydraulic motor 14 as a drive device for a continuous unloader. Also a driving hydraulic pressure of the hydraulic motor 14 corresponding to a preset target cargo handling amount is calculated by an excavating amount set part 21, and the target hydraulic pressure is output to a control and calculation part 22. The target hydraulic pressure is input into the control and calculation part 22, and an actual driving hydraulic pressure of the hydraulic motor 14 is input from the hydraulic pressure detector 20. In the control and calculation part 22, a proportional and integrating calculation is made so that the actual hydraulic pressure becomes the target hydraulic pressure so as to correct the feed speed of a bucket elevator 3. Thus the cargo handling amount can be maintained at a constant by varying the moving feed speed even if there is any irregularity on the upper surfaces of bulk loads 5 or any load collapse occurs during excavating.
MONZEN TADAAKI
TAURA RYOJI
KUMAMOTO NAOKI
JINBO HIROSHI
KOBAYASHI TERUMI
KAWAI HITOSHI
KIYOTA SHIGESHIKI
NIPPON STEEL CORP
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