Application of Short Spiral Bit/Drill Pipe in Rotary Drilling Construction

Classification:

Company News

Release time:

2019-08-30

【Summary Description】 Application of Short Spiral Bit/Drill Pipe in Rotary Drilling Construction

钻杆

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. Usually, the hard formations of rotary excavation construction mainly include riverbed (old channel), mountain and hilly gravel, boulder and weathered rock, etc., and short spiral drill bits are mainly used to drill into these harder formations./drill pipe. The selection and use of short spiral bit is an important link affecting the construction efficiency.

Structure and Classification of Short Spiral Bits

Rock-socketed short auger bits for drilling into hard formations/drill pipeThe structure is composed of flange, mandrel tube, main spiral blade (guide screw) and guide spiral 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). Other bits with non-full screw and full cone/drill pipeThe form is 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.

钻杆

Key words:

weilida drill