The effect of application methods on the service life of drilling rods
Mar 2, 2016
At present, according to direction of the blast hole, the operation modes of hand-held/air-leg rock drill can be divided into horizontal blast hole rock drilling, elevation blast hole rock drilling and depression blast hole rock drilling.
A Large number of experiments indicates that the crack of the tapered drill rods mostly happen in the working processes of elevation blast hole rock drilling and depression blast hole rock drilling. Given that a tilt angle exist between the horizontal plane and the axis of rock drill, tapered drill rod and the blast hole during the working processes of elevation blast hole rock drilling and depression blast hole rock drilling, the action point of the axial stress generated under tapered drill rod’s working state will displace and converge at the tail of the drilling rods which is weaker than other parts. The phenomenon of crack of tapered drill rod often occurs when encountering improper operations such as giving too strong impulse force, drilling in over-rigid rock or getting jammed. Moreover, factors like unstable air pressure, blunt drilling bits and overlong drilling rods for rock drilling can also lead to the crack. during rock drilling, drilling rods with over long length would result in lowered transmission efficiency of the axial stress, increased deflection, and enhanced bending stress as well, which are also the reasons for the crack on drilling rods.
In sum, in order to present the greatest efficacy, a good quality product still needs to follow the scientific application methods and modes.
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