PRESSURE REGULATING DEVICE FOR IMPACT DRIVING TOOL

摘要

PROBLEM TO BE SOLVED: To automatically regulate filler gas pressure of a hydraulically operated gas type impact driving tool. SOLUTION: In the pressure regulating device mounted on an exhaust flow passage for exhausting nitrogen gas in a gas chamber 9 of a hydraulic breaker 1, an opening/closing means to close when the gas pressure is at a permissive upper limit or lower and open when the gas pressure is over the limit is formed by a valve chest 102, a valve seat 104, a spool 110 and a spring 106. A lower end part (end part of the opposite side of the valve seat 104 side) of the valve chest 102 is communicated with an oil filler port 33 for having a lower end face (end face of the opposite side of the valve seat 104 side) of the spool 110 to receive a hydraulic pressure when the hydraulic breaker 1 is operated. Thereby the opening/closing means opens/closes according to the gas pressure when the hydraulic breaker 1 is stopped and the means stops opening/closing to maintain a closing state when the hydraulic breaker 1 is operated.