| 摘要 |
PURPOSE:To make the pay-out amount of cargo constant, by providing such an arrangement that a signal for setting the pay-out amount of cargo is received and a drive device is controlled in accordance with a signal for compensating errors caused by various factors of computed values from the actually measured value of pay-out amount and a detected value of a drive device. CONSTITUTION:A computing device 34 receives a set pay-out amount Q from a pay-out amount setting unit 35, a pressure signal P from a pressure detector 32 for detecting the primary side pressure of a hydraulic motor 31, and a speed signal V from a speed detector 33 for detecting the rotational speed of the motor 31 and an actually measured value of a pay-out amount which is actually measured by a pay-out amount measuring apparatus 39. If the difference between the set pay-out amount Q and the actually measured value W is induced by adhesion of bulk material, a pressure loss due to temperature variations, variations in excavating resistance, etc., so that the difference between the primary side pressure P' of the motor 31 corresponding to the set value Q and the signal P occurs, or if the signal V differs from a predetermined value, a hydraulic pressure control device 36 delivers an oil flow compensating signal R to adjust the discharge amount of a hydraulic pump. |
