Drill rod is one of the important accessories of rock drill. It is a necessary tool in rock drilling. Drill rod must be able to bear significant torque, torsion, bending and vibration in the process of rotation, so its quality directly affects the efficiency of rock drilling.
(1) Drill rod specifications such as material and thickness do not meet the requirements of technical specifications.
(2) There are serious scratches on the surface of the drill rod body.
(3) In the process of forging and heat treatment of drill rod, due to poor temperature control or unreasonable process, small cracks of thermal stress will occur in the drill rod.
(1) The drill rod is used for a long time, resulting in more surface damage.
(2) When reaming or drilling pilot holes for a long distance, if the speed is too fast, the drill bit will suddenly hit the hard object, which will produce a strong impact force, and the torque will suddenly increase, resulting in the fracture of the drill rod;
(3) The torque on the rock drill is greater than the torque that the drill rod inclination can bear.
In the process of rock drilling, the drill rod is subjected to repeated impact and torsion about 2000 times per minute, and there are alternating compressive stress, tensile stress, bending stress and shear stress in the drill rod. When these stresses reach or exceed the limit of drill rod, fine cracks will appear in drill rod. During underground operation, the corrosion of mine water and underground humid air will accelerate the growth of drill rod cracks, resulting in fracture.
(1). Drill rods conforming to technical specifications shall be selected.
(2). Avoid using drill rods with severe scratches.
(3). Replace the new drill rod in time.
(4). During operation, the rotating speed and propulsive force of drill rod shall be reasonably controlled.
(5). The rock drill shall be equipped with an appropriate drill rod.
This is the first one.