| 摘要 |
PURPOSE:To effectively utilize the horse power of a construction vehicle by a method in which each horse power of three liquid-pressure pumps is changed with time, a small horse power is supplied to a turning pump and its horse power is increased with time at the beginning of turning, and a horse power opposite to the foregoing case is supplied to two other pumps. CONSTITUTION:In an oil-pressure circuit system consisting of a prime mover and three pumps, a liquid-pressure motor 13 for turning is driven by a stationary capacity pump 2, and the other working machine is driven by other variable capacity pumps 3 and 4. Pilot pressures 16 and 15 are taken out of the discharge side circuit 12 and the charging side circuit 11 of the oil-pressure motor 13 of a turning circuit, a switch valve 8 in the discharge side pipeline is switched, a back pressure 29 proportional to the rotation speed of a rotator and the driving pressure 27 of the rotator are introduced from a tank line 7 to a regulator valve 21, the outputs of two variable pumps 3 and 4 are changed, and the input horse power of three liquid-pressure pumps is controlled in such a way as to keep its total horse power constant. |
