Home / How to choose a good rotary drilling tool (bucket, auger and core barrel) for your deep pile foundation?
How to choose a good rotary drilling tool (bucket, auger and core barrel) for your deep pile foundation?
As an important part of rotary drilling, choose a good drilling tool become a very important thing before construction. Firstly, what is a good drilling tools? And what are the standards for a good drilling tool? There are 7 key point:
1. Beautiful weld.
2. Three points are concentric. The whole kelly bar is concentric, the kelly box is concentric, and the center guide tooth is concentric, so that three points are in a straight line, and the drill bit rotates around the center.
If the drilling tools cannot achieve three-point concentricity, the following problems will appear:
Drilling position deviation: Due to the non-concentricity of the three points, the drill tool is easy to deviate from the predetermined position during drilling, resulting in inaccurate drilling position.
Inaccurate drilling hole diameter: Non-concentric drill tools may cause inconsistent hole diameters during the drilling process, affecting construction accuracy.
Unstable hole wall: Non-concentric drill tools may produce uneven extrusion on the hole wall during drilling, resulting in unstable hole wall and prone to collapse.
Slower drilling speed: Due to the non-concentricity of the drill tool, more time and energy are required to overcome uneven friction and resistance during drilling, resulting in slower drilling speed.
Increased equipment wear: Non-concentric drill tools will cause greater wear on the equipment during the drilling process, shortening the service life of the equipment.
Operator injury risk: Non-concentric drill tools may produce severe vibration and impact during drilling, which may easily cause the operator to lose balance or get injured.
Risk of equipment failure: Long-term use of non-concentric drill tools may cause internal parts of the equipment to loosen or be damaged, increasing the risk of equipment failure.
Material waste: Due to inaccurate drilling positions and inconsistent hole sizes, more materials may be required to fill or repair the holes.
Increased maintenance costs: Increased equipment wear and increased risk of failure will lead to increased maintenance costs.
3. Fast drilling efficiency. The bottom plate tooth arrangement is required to be good, the drill teeth are arranged in an arc shape, and the teeth on the tooth plates on both sides are staggered and not symmetrical.
If the bottom plate tooth arrangement is unreasonable, the following problems will appear:
Poor cutting effect: Unreasonable tooth arrangement may increase the contact area between the drill teeth and the formation, thereby reducing the cutting efficiency of the drill teeth.
Energy loss: Unreasonable tooth arrangement design may increase energy loss during drilling, slowing down the drilling speed.
Uneven wear: Unreasonable tooth arrangement may cause some drill teeth to bear excessive load, thereby accelerating their wear.
Shortened life: Due to increased wear, the overall life of the drill tool will be shortened and the frequency of replacement will increase.
Material waste: Due to reduced drilling efficiency and increased wear of drill tools, more materials may be required to repair or replace the drill tools.
Increased time cost: Frequent replacement and maintenance of drill tools will extend the construction period and increase time cost.
Irregular drilling: Unreasonable tooth arrangement may lead to irregular drilling shape, affecting the quality of subsequent construction.
Formation damage: Unreasonable tooth arrangement design may cause excessive damage to the formation, affecting the stability of underground structures.
Risk of equipment failure: Improper tooth arrangement may cause failure of the drill bit during operation, such as breakage or falling off, thereby increasing the risk of equipment failure.
Risk of personal injury: Equipment failure may cause injury to the operator, increasing safety hazards.
4. High soil feeding efficiency. There is no step between the tooth plate and the bottom plate. Steps will hinder the smooth drilling of the drilling tools, requiring additional energy to overcome the resistance caused by the unevenness during the drilling process, affecting the drilling speed and efficiency.
5. Good positioning. The pilot tip is higher than the tooth plate, which is convenient for positioning. The height of the pilot tip is crucial to ensure the verticality and position accuracy of the drilled hole. If the pilot tip is not higher than the tooth plate, the vertical deviation of the drilled hole may increase, thus affecting the construction accuracy.
6. The unlocking mechanism is flexible and not stuck.
7. The inside of the drilling tools is clean. The inside of the drilling tools is not easy to observe, and it can better reflect the details of production.
Raw material preparation Select high-quality steel, such as alloy structural steel, to ensure that it has sufficient strength and wear resistance.
Flame cutting and blanking Making blank parts of each component with flame cutting machine
Roll forming Roll the cut steel plate into a tube through a roll machine.
Turning Cutting shaft parts with lathes, milling machines and other machine tools.
Welding Welding the parts cut out according to the drawings.
Assembly and debugging Assemble the various components into a complete rotary drilling tool and debug it to ensure its stable and reliable performance.
Quality inspection Ensuring that the quality of the drilling tool meets the standards with various inspection methods, such as size measurement, flexibility testing, etc.
