Construction Mode of Short Spiral Bit in Outer Flat Drill Pipe

Classification:

Company News

Release time:

2019-08-09

【Summary Description】 Construction Mode of Short Spiral Bit in Outer Flat Drill Pipe

外平钻杆

Very practical in recent years.The large-diameter rotary drilling method has been widely promoted in pile foundation construction. In the construction of large diameter rotary drilling, hard formation drilling is one of the main problems encountered in the construction. Generally, the hard stratum for rotary excavation mainly includes riverbed (old channel), pebble-bearing gravel, boulder and weathered rock stratum in mountainous and hilly areas, and the short screw bit is mainly used to drill these hard stratum.Outer screen drill pipecohesiveThe selection and use of short spiral bit is an important link affecting the construction efficiency.

Let's summarize belowOutside flat drill pipeWorking principle of articulation of short helical drill bits

The rock-socketed short auger bit structure for drilling hard formation consists of flange, mandrel tube, main helical blade (guide screw) and guide helical blade (cone). The commonly used rock-socketed short spiral drill bits can be divided into single-cone single-screw short spiral drill bits and double-cone single-screw short spiral rotary drill bits, and double-cone double-screw short spiral drill bits.

Single-cone single-screw short spiral drill refers to a spiral drill bit composed of a set of main spiral blades (guide screw) and guide spiral blades (cone), and double-cone double-screw refers to a combination of two sets of main spiral blades (guide screw) and two sets of guide spiral blades (cone). The double cone single screw short spiral bit is composed of a group of main spiral blades (guide screw) and two groups of guide spiral blades (cone).Outside flat drill pipeunderstand thatThere are other non-full screw and cone drill bit forms, which are generally less used. The blade spacing of a single cone and a single screw is equal to the lead, and the blade spacing of a double cone and double screw is equal1/2 lead. The upper part of the guiding spiral blade is provided with a cutting tool to undertake the task of drilling broken rock and discharging soil (stone), and the flat spiral blade has the function of guiding and discharging soil (stone). The cutting tool is generally a pick with tungsten-cobalt carbide head insert welding..

Key words:

weilida drill