COUNTERCIRCULATION CORE DRILL WITH WATER CONTROLLING MEANS

The utility model belongs to a countercirculation core drill with water controlling means. A water controller is added between the spray inverse device and the inner tube chamber of the existing countercirculation drill. The water controller comprises a water diversion joint and a water controlling needle valve, and the joint is provided with a water inlet cone hole and a water controlling cone hole and communicated with the back drainage hole of a diffusion joint. The utility model has the advantages of simple structure and good quality of coring; the production efficiency is increased greatly; the average taking rate reaches more than 98%; the month efficiency of each drill, the highest drill efficiency of the single hole and the back footage are great higher than the existing drill; the utility model is suitable for all complicated stratum drilling such as leakage strata, gushing water strata, hard strata, crisp strata, broken strata, butter strata, spongy strata, etc.