A HIGH PRESSURE DTH DRILLING MACHINE IN 4' SERIES (100MM TO 130MM)

摘要

The invention relates to an improved high-pressure down-the -hole (DTH) drilling system in 4"-series capable of efficiently penetrating hardest grounds for mining and construction quarrying, comprising a main frame with at least two crawler chains coupled to corresponding numbers of pneumatic propel motors a hammer actuatable by compressed air and providing periodic impact on a drill bit by a reciprocating piston of the hammer, one end of the hammer connected to at least one string for allowing compressed air to flow to the drill bit via the string and the hammer, a plurality of cylindrical pipes joined through their male and female threaded connectors to form a plurality of strings which connect the hammer and a rotary head for providing a desired weight on the drill bit and simultaneously acting as an annulus for the compressed air to flow through the strings to the hammer, a mast acting as a guide and holding the rotary head so as to allow the rotary head to move in registration with the drill-hole-axis, a rotary head acting as the pneumatic drive to the drill system, and being fitted on the mast via a swivel arrangement, for providing rotation to the drill string including the hammer enabling appropriate indexing at the hole-bottom for drilling, a boom having hydraulic cylinders for holding the mast during the drilling operation including imparting requisite orientation to the mast, the hydraulic cylinders being powered by a combination of a hydraulic pump and a pneumatic motor, an air-compressor constituting the prime power source providing via a drive air-line air at desired pressure and volume to the drilling system, and a drill bit for penetrating the ground in correspondence with the feed rate, weight and impact provided by the hammer and a feed assembly. A high-reduction pressure regulator (which can withstand input pressure of beyond 200 psi), and a safety valve incorporated on the drive air line enabling feeding of the pneumatic drive motors the air at a pressure of about half the pressure of the air provided simultaneously from the same air-compressor, which delivers high pressure for example, beyhond 200psi to the hammer and the bit.