| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an impact fastening tool which is smoothly operated by increasing a force acting in relation to a first motion of a piston, and in which fastening accuracy is made uniform and the accuracy is improved.SOLUTION: In an impact fastening tool, that fastening torque reaches a specified value is detected by a relief valve which is made to open by the pressure of working oil of a hydraulic pulse generator, a shut-off valve which blocks air supply to a motor is actuated by acting of the pressure of the working oil passing through the relief valve to a piston through the passage of the working oil, and a communication member communicates with an opening of the passage of the working oil at a position at which the passage of the working oil formed at a liner upper cover opens. The passage of the working oil is provided which opens at the central position of the piston edge surface and the hydraulic pulse generator side, respectively. A separation member is provided with a flowing hole between the communication member and the piston so that the piston edge surface does not come into contact with the opening surface at which the passage of the working oil of the communication member opens.</p> |
