| 摘要 |
PURPOSE:To make it possible to apply a sufficiently large braking force to a moving member of a feeding and driving shaft system of a long stroke by driving a hydraulic motor which imparts braking force to the moving member with an oil pressure of a value proportional to the moving speed of the moving member. CONSTITUTION:A torque motor 58 is rotated at the speed of a value a constant number of times the value of a moving speed signal 54 detected from a rotational speed detector 57 provided in the moving member 50. The flow quantity of an operating oil discharged through a hydraulic servo valve 62 driven by the torque motor 58, becomes proportional to the value of the moving speed, and passes through an orifice 65 of a bypass pipeline 64 to generate an oil pressure having a value proportional to the moving speed, at both ends of the orifice 65. A driving force is given to the hydraulic motor 66 by this oil pressure and a braking force is acted upon the moving member 50 between a pinion 67 directly coupled to the hydraulic motor 66 and a rack 68 on a stationary bedplate 53. |
