What are the common rotary drilling bits?

Common rotary drilling bits include spiral drill bits, rotary digging buckets, barrel core bits, expanded bottom bits, percussion bits, punching taper bits and hydraulic grabs, which are briefly introduced below.

1.1 Spiral drill
(1) Cone: Double-headed double screw, suitable for hard bedrock. Double-headed single snail, suitable for weathered bedrock, pebbles, frozen soil, etc. The above drills are equipped with various picks, and many types of drills can be derived from changes in tooth profile, pitch, and helix angle.

(2) Straight spiral drill bit:
a. Bucket tooth straight snail: double-headed double snail, suitable for sandy soil, small diameter gravel layer with poor cementation; double-headed single snail, suitable for sandy soil, soil layer; single-headed single snail, suitable for large diameter poor cementation Pebble, cohesive soil and hard clay.

b. Picked straight snails: There are double snails, three snails and four snails, which are suitable for hard bedrock or gravel.

1.2 Rotary drilling bucket
According to the installed teeth, it can be divided into pick drill bucket and bucket tooth drill bucket; according to the number of bottom plates, it can be divided into double bottom bucket and single bottom bucket; according to the number of doors, it can be divided into double door bucket and single door bucket; according to the number of buckets The taper can be divided into cone barrel drill bucket and straight barrel drill bucket; according to the shape of the low plate, it can be divided into pot bottom drill bucket and flat bottom drill bucket. The above structural forms are combined with each other, plus the change of whether there is a vent hole and the door opening mechanism, dozens of types of rotary drilling buckets can be combined. Generally speaking, double-bottom drilling buckets are applicable to a wide range of formations, single-bottom drilling buckets are only suitable for relatively viscous soils, and double-door drilling buckets are applicable to a wide range of formations. Single-door drilling buckets are only used for large-diameter pebbles and Hard clay.

1.3 Barrel core bit
There are currently two common types: pick barrel drills (suitable for medium-hard bedrock and gravel), roller cone drills (suitable for hard bedrock and large boulders). Among the two major types of barrel core drill bits, the difference between the core device and the non-coring device depends on the difficulty of coring. Because cone core bits are mainly used for hard rock drilling, and the drilled ring area is large, if conditions permit, reverse circulation drilling can be installed in the bit part to improve drilling efficiency.

1.4 Bottom drill
On the basis that the pile diameter does not increase and the pile depth does not increase, in order to improve the bearing capacity of a single pile, the design department often implements the expansion of the bottom pile. The bottom drill bit is fine. Bottom-reaming drill bits are commonly used mechanically. This type of drill bit is relatively simple to use and maintain. There are top-opening and bottom-opening types. The opening mechanism is generally four-bar linkage, which is used for soil, strong wind, and moderate weathering. The formation is even hard bedrock. Since the rotary drilling is a non-circular drilling, the slag cleaning bucket can be used to clear the slag after the bottom expansion is completed.