Percussion drilling method The characteristic is that the drilling tool breaks the rock by punching, including the three main processes of punching, rotation and slag removal. Use Top Hammer Drilling Tools to drill shallow blastholes and small diameter deep blastholes, and use DTH drills and wire rope percussion rigs to drill large diameter deep blastholes. Rock drill (pneumatic drill) is suitable for drilling rocks in rocks above medium-hardness. The diameter of the blasthole is usually 35-65mm, and the depth generally does not exceed 15m. According to power, there are four types: pneumatic, hydraulic, electric and internal combustion. Pneumatic rock drills are currently the most widely used, but the latter two are rarely used. Hydraulic rock drills have fast drilling speed, low power consumption and low noise, and are being promoted and applied in some countries. The drill tool of the rock drill is composed of a drill bit, a drill rod and a drill tail. When drilling shallow holes, the shank tail and the drill rod are usually integrated, and the drill bit is mounted on the drill rod. The drill bit, drill rod and drill tail as a whole is rarely used. When drilling deep holes, the shank, shank and shank are made separately, and the shank is extended one by one with the deepening of the blast hole. The rock drill is installed on the air leg, on the drill frame or on the rock drilling rig to drill the hole. Nowadays, the drill bit of flake or cylindrical cemented carbide is widely used. For shallow holes, in-line sheet alloy bits are often used, for deep holes or shallow holes in rocks with developed fissures, cross-shaped or T-shaped bits are often used. The columnar alloy drill bit is suitable for rock drills with large impact power and low speed, and drill holes with a diameter greater than 40mm. The drill rod is used to transfer impact energy and torque, and is made of hexagonal or round hollow alloy steel. The shank directly bears the impact of the piston. The shape and size depend on the Button Bits model. The shank tail, the drill rod and the drill bit need to be heat treated according to the use conditions and materials to increase the service life.
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