| 摘要 |
A hydraulic breaker with an idle blow preventive structure is provided to minimize useless striking of the hydraulic breaker by stopping a piston and shutting off hydraulic pressure after breaking, and to extend the life span by preventing damage of the hydraulic breaker. In a hydraulic breaker(1) with an idle blow preventive structure, a lower idle blow preventive sill(37b) is connected to an upper part of an upper chamber(36b) and formed to be larger than a lower piston ring(31b). An upper idle blow preventive sill(37a) is formed to be larger than the outer diameter of an upper piston ring(31a) and placed in an upper part of a bypass chamber(36c). A hydraulic recovery passage(81) is formed in the upper idle blow preventive sill to flow hydraulic pressure through a low pressure passage(8). A select switch(9) is installed in a hydraulic supply line(61) of a hydraulic circuit(6) to prevent idle striking of a piston(31) by supplying high hydraulic pressure to a high pressure connector(32). First and second sensors(9a,9b) are installed in a cylinder body(3) and a print head(4) to turn on and off the select switch. |
