How to Choose Rock Drilling Tools for Hydraulic Rock Drill Jumbo?

Table of Contents

Hydraulic rock drill jumbo is a machine that can support the rock drill to drill rock holes and walk with various powers. It is widely used in the construction of mines, tunnels, water conservancy, and other projects. When choosing a hydraulic rock drill jumbo, in addition to considering the performance and price of the equipment itself, you also need to pay attention to a very critical link – the matching of rock drilling tools. The right rock drilling tool is significant for hydraulic rock drill jumbos’ performance and construction efficiency.

Understand the types of rock drilling tools

Rock drilling tools are the primary tools of hydraulic rock drill jumbos. There are many types of rock drilling tools. Rock drill bits and drill rods are the core products.

Rock drill bits

rock drill bits

To achieve the ideal rock drilling rate, it is required that the drill bit can effectively break the rock. Foreign users often use the index of rock drilling rate to evaluate the rock drilling speed of rock drill bit. Among the cross bits, X bits, and button bits, the rock-drilling rate index of ogive drill bit is the largest, followed by button bit and chip drill bit. Therefore, in the middle and deep hole drilling, the rock drilling speed of chip drill bit is the lowest, but in the comparison of drilling straightness, the drill bits that achieve the minimum deflection effect is X drill bit, followed by ogive drill bit, and button bit.

In addition, during the normal service life of button bit, it is necessary to avoid grinding the head of drill bit into a convex shape as much as possible. Because a worn drill bit not only reduces the chisel speed but also makes it easier to produce a skewed hole. During the rock drilling of button bit, the first thing is that gauge teeth are worn out, so the wear resistance of carbide button of button bit should be taken very seriously. At the same time, when drilling in medium to deep holes in low abrasive rocks, deep concave button bits are often used. When choosing a drill bit for drill jumbo, the type of drill bit should be determined according to the rock conditions.

Drill rods

drill rods

According to the steel grade of hollow steel, the controlled cooling after rolling, and the surface hardness of the rod, three types of rods are mainly used in foreign hydraulic drill jumbos, which are surface-hardened rods, carburized rods, and carburized MF rods.

The toughness of surface-hardened rods is better than the overall carburized rods, but the fatigue life is lower, and these rods can be used for drilling interbedded rocks or fissured rocks. Carburized rods have good wear resistance and fatigue life, but their carburizing and air-cooling process requirements are very strict. When drilling holes with a depth of more than 20m, integral carburized rods and guided retract button bits can better control the deflection of holes and increase the service life of rock drilling tools.

In the drill rod connected by casing, the energy consumption generated at the connection is 6% when the T-thread is tightly connected and will exceed 10% if the threaded connection is poorly matched. High heat caused by energy consumption at the connection not only damages the thread but also tends to form a source of fatigue. Therefore, most foreign users choose long drill rods to reduce the connection points in the rock drilling tools when working on open-air projects.

drill rods

MF rods were introduced by Kometa Finland in the late 80s for medium and deep holes, as the mass (weight) of these rods at the connection is less than 60% of casing connection rods. Therefore, the impact energy transfer is very effective. At the same time, because MF rod can maintain a tight connection throughout the rock drilling process, the energy application effect is also more significant than that of the casing-connected drill rod. This type of drill rod also has the advantage of easy automatic loading and unloading connection for rock drill jumbos, and it has become the main drill rod chosen for rock drill jumbos for open-pit medium and deep holes.

Pay attention to the hardness and wear resistance of rock drilling tools

rock drilling tools

Rock drilling tools’ hardness and wear resistance are critical to their longevity and efficiency. Generally speaking, insufficient hardness can lead to premature wear of rock drilling tools, while excessive hardness may result in construction challenges. Therefore, it is essential to carefully choose the appropriate hardness based on the construction environment and the type of rock.

Furthermore, wear resistance is another critical factor to consider. Frequent replacement of drill tools due to wear can significantly impact construction efficiency. Therefore, selecting rock drilling tools with optimal wear resistance is essential to ensure prolonged tool life and minimize disruptions in construction activities. Striking the right balance between hardness and wear resistance is critical to achieving optimal performance and longevity of rock drilling tools in various drilling conditions.

Considering the size and weight of rock drilling tools

rock drilling tools

Indeed, the size and weight of rock drilling tools directly affect the operating performance of hydraulic rock drill jumbos. If a rock drilling tool is excessively large or heavy, it may impede the regular operation of the drill jumbo. Conversely, rock drilling tools that are too small or light can compromise the construction effect.

When selecting a rock drilling tool, it’s crucial to carefully determine the appropriate size and weight based on the model of the hydraulic rock drill jumbo and the specific requirements of the construction project. It ensures that rock drilling tools are compatible with the equipment and capable of delivering optimal performance, contributing to the efficiency and effectiveness of the overall drilling operation. Matching the right size and weight of rock drilling tools to the drill jumbo is essential for achieving successful and productive construction outcomes.

Compare products from different brands and manufacturers

Selecting rock drilling tools involves navigating a diverse market with various brands, manufacturers, price ranges, and quality levels. When choosing rock drilling tools, sufficient investigation and comparison are required. Utilizing user reviews and professional evaluation reports available on the Internet can provide valuable insights into the strengths and weaknesses of different products.

Considering factors such as durability, efficiency, and compatibility with specific drilling requirements is crucial. Additionally, after-sales service is critical. Opt for manufacturers that offer reliable after-sales support, ensuring access to timely technical assistance and maintenance services during the tool’s usage.

In summary, a comprehensive approach that includes user feedback, professional evaluations, and attention to after-sales service can guide you in choosing rock drilling tools that best align with your needs and expectations.

Taking into account costs and benefits

Considering cost and benefits is an indispensable component of selecting rock drilling tools for hydraulic rock drill jumbos. The wide range of prices among different brands and types of rock drilling tools necessitates a careful assessment based on actual needs and budget constraints.

It’s critical to weigh the initial cost against long-term benefits, and we should consider factors such as durability, wear resistance, and maintenance requirements. A more expensive but durable and efficient rock drilling tool might offer better value over its extended service life compared to products that are cheaper and require frequent replacement.

Moreover, the impact of service life and replacement frequency of rock drilling tools on construction costs should be a key consideration. Balancing the upfront cost with long-term savings through reduced replacement and maintenance expenses is vital to maximizing construction efficiency while minimizing overall costs.

In essence, a comprehensive evaluation that encompasses upfront costs, long-term benefits, and the overall impact on construction expenses is necessary for making an informed decision when selecting rock drilling tools for hydraulic rock drill jumbos.

In summary, choosing suitable rock drilling tools for hydraulic rock drill jumbos is a multifaceted decision that requires careful consideration of various factors. Through comprehensive evaluation, we can choose the most suitable products, better utilize the performance advantages of hydraulic rock drill jumbos, and improve the quality and efficiency of engineering construction.

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