| 摘要 |
PURPOSE:To exactly stop a slewing body at a stopping position by controlling the tilting operation of an oil-pressure pump in such a way that the detected value of slewing speed of a slewing body, set values of stopping positions, and calculated values of stoppage torque and inertial moment become constant. CONSTITUTION:The pressures of main circuits A and B are detected by sensors 20a and 20b, and the tilting angle of the inclined plate 15a of a variable capacity both-side tilting oil-pressure pump 15 are detected by a sensor 19. The detected values, together with outputs of the angle sensor 21 of an upper slewing body and a stopping position setter 22 of the upper slewing body, are put in an arithmetic unit 23 where the remaining angle, angular speed, and angular acceleration of the upper slewing body until the stopping position are calculated from the outputs of the sensors 31 and 22. From the calculated values and the outputs of the sensors 20a and 20b, stoppage torque and inertial moment are calculated to obtain flow rates. When the flow rate is increased beyond the interval until a given stopping position, the supply of the pressure oil to the oil-pressure motor is reduced, and the plate 15a is controlled in such a way as to keep the ratio between the inertial moment and the stoppage torque constant. |
