| 摘要 |
<p>PURPOSE:To facilitate fastening or loosening operation of a nut by connecting a hydraulic cylinder of a hydraulic torque wrench to a hydraulic pump by a high pressure hose, and arranging an air pump in a driving part of the hydraulic pump. CONSTITUTION:A stop valve 17 is opened, and compressed air is inserted in a hydraulic pump 9 as an arrow 20 by operating an air piston 12. Thereby, high pressure oil is supplied in a hydraulic cylinder 2 through a high pressure hose 8 as an arrow 21, and projects a piston rod 4 in the direction of an arrow 22. Thereby, a driving lever 6 is rotated in the direction of an arrow 23, and rotates a ratchet socket 5 as an arrow 24, and fastens a nut. When a cylinder 10 reaches a prescribed position, a detector 25 is actuated, and switches an automatic directional control valve 15, and sends pressurized air in the arrow 27 direction, and returns a cylinder rod 10 in the arrow direction 26 together with the piston 12 of a pneumatic cylinder 11. Thereby, the hydraulic pump 9 is put under negative pressure, and a hydraulic cylinder 2 is retreated, and the high pressure oil is returned to the hydraulic pump 9.</p> |
