In the rapidly developing tunnel construction industry, rock drill jumbos are an indispensable construction tool, and their performance and efficiency are directly related to the progress and cost of the entire project. Especially in the construction of mountain tunnels, the drilling efficiency of the rock drill jumbo determines the excavation speed and directly affects the subsequent support and lining work. Therefore, in-depth exploration and optimization of critical operating parameters of rock drill jumbos to significantly improve their drilling efficiency has become a hot topic in the current field of tunnel construction. This article will explore how to improve the drilling efficiency of rock drill jumbos by adjusting crucial operating parameters.
Key parameters
Propulsion pressure
Definition: propulsion pressure is the pressure exerted on the drill bit by the rock drill jumbo during drilling, which directly affects the drilling speed and efficiency of the drill bit. Research shows that the propulsion pressure and drilling speed have a linear relationship, i.e., if the propulsion pressure increases, the drilling speed will be increased accordingly.
Optimization suggestion: in practice, it is important to control the propulsion pressure within a reasonable range. Research indicates that the upper limit of this reasonable threshold is 8MPa. When the propulsive pressure reaches this value, the maximum drilling speed can be achieved. However, excessively high pressure may cause equipment damage, so it must be carefully set.
Impact pressure
Definition: impact pressure is the impact force produced by the impact piston of the rock drill on the drill rod. Stress waves are transmitted to the rock mass, causing it to break. Different from the propulsion pressure, the relationship between impact pressure and drilling speed exhibits a quadratic parabolic characteristic, meaning that there is an optimal impact pressure value that maximizes the drilling speed.
Optimization suggestion: to obtain the best drilling efficiency, drilling speed and drilling energy consumption per unit volume should be comprehensively considered. Enterprises can determine the optimal range of impact pressure under different rock qualities through tests and data analysis. Generally speaking, the optimal solution for impact pressure is between 15 and 17MPa, with an average value of 16MPa. In actual operation, the impact pressure should be adjusted to the optimal value according to the specific conditions of the rock to achieve the best drilling efficiency.
Rotation speed
Definition: rotation speed is the rotation speed of the drill bit during drilling. It has a relatively small impact on drilling speed, but it will still affect drilling efficiency and quality to a certain extent.
Optimization suggestion: since the rotation speed has little effect on the drilling speed, there is no need to set the rotation speed too high in actual operations. A reasonable rotation speed can ensure stable drilling of the drill bit while reducing energy consumption and wear.
Relationship between rock properties and drilling parameters
The nature of the rock is a critical factor that affects the rock drill jumbos’ drilling efficiency. Rocks with different hardness, strength, and integrity have different requirements for drilling parameters. For instance, when drilling into hard rocks, it’s necessary to increase the propulsion pressure and impact pressure to generate enough crushing force. Conversely, when drilling in rocks with poor integrity, it’s crucial to decrease the impact force to avoid rock fragmentation. Applying excessive force can result in problems like drill sticking or hole collapse. Therefore, before commencing construction, a thorough geological survey and testing of the physical and mechanical properties of the rocks should be carried out to comprehend their characteristics and properties. Reasonably set and adjust the drilling parameters of the rock drill jumbo according to the nature and characteristics of the rock to ensure its efficient operation under different rock conditions. At the same time, during the construction process, drilling parameters should be adjusted in time according to actual conditions to cope with changes in rock properties.
Conclusion
In the study of improving the drilling efficiency of rock drill jumbos, the optimization of critical parameters is more important. Therefore, in practical use, by reasonably adjusting parameters such as propulsion pressure, impact pressure, and rotation speed, the rock drill jumbo’s drilling efficiency can be significantly increased, leading to reduced construction costs. In the future, technology will continue to advance, leading to further improvements in the performance and functions of rock drill jumbos. At the same time, more research results will emerge regarding the factors that influence drilling efficiency. We eagerly anticipate delivering more efficient and dependable mechanical equipment and solutions for the tunnel construction industry through ongoing exploration and practical application.
