Page 240 - Demo

238 ISCAR DEEP HOLE DRILLINGDTS Drill StructureThe DTS drill is an assembly tool for deep drilling.The main elements are the drilling head and a two-layered stem. The stem consists of an outer tube and an inner tube (Figure 6.7.2.1).Figure 6.7.2.1drilling headtwo-layered stemdrilling headouter tubeinner tubeThe drilling head is screwed on the outer pipe using a rectangular thread with a coarse pitch. The thread on the drill head and outer pipe can start one or four-start, depending on the type of drill and the diameter of the drilling. The diameter of the outer drill pipe is slightly less than the diameter of the drill head (Figure 6.7.2.2).Figure 6.7.2.2DgapThe inner pipe is inserted into the drilling head until it reaches the stopper (Figure 6.7.2.3).Figure 6.7.2.3drilling headstopper4-start threadouter tube inner tubeGenerally, sloped slots are located at the tail end of the inner tube. The location of the inclined slots on the inner pipe is not random since the efficiency and performance of the ejector drill system depend on its position (Figure 6.7.2.4).