In a complex and ever-changing engineering environment, DTH drill bits are the core component of drilling operations, and their performance directly affects project progress and cost-effectiveness. As carbide buttons, as DTH drill bits, directly act on critical parts of the rock, the selection of their assembly interference is even more crucial. The correct amount of interference can significantly improve the drill bit’s rock-breaking efficiency and service life and effectively avoid common problems such as tooth loss, ensuring the continuity and safety of engineering operations. This article will discuss the importance of selecting the interference amount for alloy tooth assembly of DTH drill bits and provide practical references for engineers.
The relationship between DTH drill bits and carbide buttons
- Drilling efficiency: the material, shape, and number of carbide buttons directly determine the drilling efficiency of the DTH drill bit. High-quality carbide buttons have better wear resistance and impact resistance and can maintain a high drilling speed in solid formations, thus improving overall construction efficiency.
- Drilling quality: the shape and arrangement of the carbide buttons directly affect the drill bit’s drilling trajectory and hole diameter quality. A reasonable carbide button design can reduce vibration and offset during drilling, ensure the roundness and verticality of the hole diameter, and improve drilling quality.
- Service life: the connection method between the carbide buttons and the drill bit body (such as brazing, hot embedding, and cold pressing.) and the selection of the assembly interference have a crucial impact on the service life of the drill bit. Reasonable assembly process and interference amount can effectively prevent the carbide buttons from falling off, thereby extending the overall service life of the drill bit.
Carbide buttons are a crucial part of DTH drill bits, and there is a close relationship. The choice of fit directly affects the secure attachment of the carbide buttons to the drill bit, ultimately impacting the performance and lifespan of the entire drill bit.
Definition and function of carbide buttons assembly interference
In simple terms, assembly interference refers to the tightness of fit between carbide buttons and tooth holes. Reasonable interference can ensure that carbide buttons can be firmly fixed in the tooth holes and not easily fall off when subjected to high-frequency impact and formation anti-torque.
The functions are mainly reflected in the following aspects:
- Enhance the ability to fix buttons: appropriate interference can increase the friction between carbide buttons and tooth holes, improve the effect of fixing buttons, and prevent carbide buttons from falling off during drilling.
- Extend service life: reasonable interference can reduce the relative sliding between carbide buttons and tooth holes, reduce wear, and thus extend the overall service life of the drill bit.
- Improve drilling efficiency: stable carbide buttons can ensure that the drill bit maintains efficient and stable rock-breaking ability during drilling and improve drilling efficiency.
Consequences of Improper Interference Selection
If the interference is not selected appropriately, a series of problems will arise:
- Too small interference: insufficient fixing force, carbide buttons will easily fall off under high-frequency impact, resulting in drill bit failure.
- Too much interference: although the tooth-fixing force is enhanced, too much interference will cause the tooth hole to burst, reduce the tooth-fixing effect, and even damage the drill bit.
How to choose a reasonable interference amount?
To select a suitable interference amount, we can take the following steps:
- Theoretical analysis: based on the thick-walled cylinder theory, Tresca yield condition, and full increment theory, mechanically analyze the fit between carbide buttons and drill bit and calculate the theoretically optimal range of interference amount.
- Finite element simulation: use the finite element simulation software to simulate the assembly process of carbide buttons, analyze the stress distribution and deformation between alloy teeth and tooth holes under different amounts of interference, and further verify the reliability of the theoretical calculation results.
- Field test: based on theoretical analysis and simulation verification, a field test is carried out to check the reasonableness of the amount of interference through actual use and adjust and optimize according to the test results.
Conclusion
The selection of the interference amount of the carbide buttons assembly of the DTH drill bit has a vital impact on the performance and service life of the drill bit. Through the combination of scientific theoretical calculation, finite element simulation, and field tests, we can accurately determine a reasonable range of the interference, thereby effectively improving the bit’s tooth-fixing ability, extending its service life, and improving drilling efficiency.
In the future, with the continuous development of material science, computer simulation technology, and intelligent manufacturing technology, the selection of the interference fit of carbide buttons in DTH drill bits will be more accurate and efficient. We believe that with the continuous promotion of science and technology, the performance of DTH drill bits will be further improved, providing more reliable and efficient drilling solutions for various engineering construction projects.
