| 摘要 |
<p>A clamping control device of a hydraulic pulse wrench, wherein a pressure introducing path (28) is branched off from a bypass passage (27) for allowing communication between a high pressure chamber (H) and a low pressure chamber (L), a fixed restriction (27a) is installed on the part of the bypass passage (27) which is closer to the high pressure chamber (H) than to the portion from which the pressure introducing path (28) is branched, the pressure introducing path (28) being connected to the primary side of a relief valve (31), an auto shutoff mechanism (41) is operated by a hydraulic oil pressure relieved to the secondary side of the relief valve (31) so as to stop air supply to an air motor (11), and a relief pressure regulating means (43) is installed to regulate a relief pressure of the relief valve (31), whereby a highly accurate clamping torque control can be made with a simple structure.</p> |
