1.Description: The mechanical-hydraulic drilling jar is a jarring and stuck releasing tool. It integrates the up jar and down jar and can release the stuck accident occurring during drilling operation. The drilling jar is an ideal tool for directional well and deep well drilling. Operating principle 1.Operating principle of up jar Lifting drilling tool, slip assembly which bear the acting of dish reed elastic force and slip locking force compels latch mechanism of slip clasp slip mandrel. While slip mandrel up run with mandrel to overcome slip locking force and damping action between hydraulic valve assembly and spindle extension, jar Make drill stem accumulate energy, delay time. When mandrel up run to the state of release constraint, elastic potential energy accumulated in drill stem will convert to upward kinetic energy, generate up jar. If need sequence up jar, you need fed off drilling tool till relock latch mechanism, reduplication above process, Generate sequence up jar. 2.Operating principle of down jar The loosen load of down jar lock can be transfer as per in demand .There are a certain ratio between up locking force and down locking force , and the ratio is adjustable. If down jar, fed off drilling tool until pressure reach to down locking force, jar should generate down jar force. If need to repeat jar, lifting drilling tool to anew securing position repeat above process.