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Usage precautions for drill rodsour advice

There are many factors that affect the service life of the drill rod, and they are relatively complex. In addition to internal factors such as steel type, smelting and rolling process, forging and brazing, heat treatment process, surface strengthening and anti-corrosion treatment, the use conditions (i.e. external factors such as rock drill type, wind pressure, rock type) .hardness, pH value of mineral water, bit condition, rock engineering operations, etc.) also affect the rock drilling life of the drill rod. Therefore, even a drill rod made of high-quality hollow steel will be damaged if it is not paid attention to during use. The ideal rock drilling life cannot be obtained. Practice shows that in order to maximize the service life of the drill rod, the properties of the drill rod, bit, rock drill, rock, etc. must be adapted. The following is a brief description of some issues that should be paid attention to when using the drill rod.

The steel type or heat treatment system of the drill rod should be selected based on the rock hardness.

A hard drill rod can be used to cut soft rock, and a soft drill rod can be used to cut hard rock. For drilling hard rock, a light rock drill with high impact frequency is more suitable, while for tough and wear-resistant rocks, it is best to use a rock drill with low frequency and high impact force. In addition, when drilling hard rock, the blade angle of the bit can be increased from 110° to 120°.

Choose a drill rod of appropriate length according to the depth of the blast hole

The longer the drill rod, the easier it is to bend. Therefore, the additional bending stress endured by the long drill rod is greater than that of the short drill rod. The greater the bending stress, the easier it is for the drill rod to break. Therefore, it is necessary to avoid using a long drill rod that is too deep than the blast hole. When the depth of the blast hole is too large, you should avoid using the same long drill rod from the opening to the end. In this case, you should use several drill rods of different lengths, which is the so-called "set drill".

Select the drill rod cross-section size according to the type of rock drill.

The impact power of the piston, that is, the striking force of the rock drill, has a great influence on the life of the drill rod. If a drill rod with a small cross-section is selected that is not suitable for the rock drill, the additional bending stress will increase, causing the drill rod to break early.

Extend the service life of drill rod

In order to extend the service life of the drill rod, the rock drill should never work at low propulsion, and the axial force applied to the drill rod must be moderate.

Choose a drill bit of appropriate shape and pay attention to the degree of wear of the drill bit.

Practice has proved that the harder the rock and the slower the drilling speed, the faster the fatigue damage of the drill rod will occur and the shorter the life of the drill rod will be. Therefore, using a drill bit suitable for rock conditions plays an important role in preventing early breakage of the drill rod. A straight-shaped drill bit is usually used. In places where rock cleavage is well developed, a cross-shaped drill bit should be used to avoid bending of the drill rod. It is forbidden to use a large drill bit with an excessively large drilling surface that is not suitable for the drill rod. Otherwise, the drill rod will be stressed too much and may easily cause early breakage. At present, some places use drill bits for 25mm hexagonal drill rods with 22mm hexagonal drill rods, which is obviously inappropriate. A blunt drill bit must be replaced or sharpened in time, because the stress generated by a blunt drill bit during rock drilling is much higher than that of a normal drill bit, which can easily cause the drill rod to break early.

Control the appropriate air pressure and do not increase the air pressure inappropriately in order to drill quickly.

Especially when a drill rod is first used, high wind pressure should be avoided to prevent the drill rod from breaking early due to overload. It is best to lower the air pressure when the drill rod is first opened, and then increase the air pressure to normal, which will play a greater role in improving the service life of the drill rod.

The worn rock drill rotating sleeve must be replaced in time.

The gap between the worn rotating sleeve and the drill tail handle increases and becomes larger as it is worn, so that the impact of the piston becomes an oblique impact. The impact force is therefore uneven, which reduces the rock drilling speed and causes the use of the drill rod. Reduction in life span. At the same time, with the development of wear, the casing and the drill tail bite each other, causing operating accidents. In addition, a worn rotating sleeve will accelerate the wear of the tail part of the drill rod.

When using an air leg rock drill, ensure that the axis of the rock drill and drill rod are consistent.

Otherwise, great bending stress will be generated in the drill rod, which will accelerate the breakage of the drill rod.

During the use and transportation of the drill rod, avoid knocking and collision to prevent scratches.

When scratches occur on the surface of the drill rod, stress concentration will occur, thereby reducing its service life. At the same time, bending must be prevented. A bent drill rod will cause bending stress during rock drilling, accelerate fatigue, and lead to premature breakage. In addition, the bent drill rod tail part also wears faster.

Try to prevent the drill rod from rusting.

The corrosion on the surface of the drill rod and inside the water hole can become a source of fatigue, thus accelerating the breakage of the drill rod. Therefore, the drill rod should be placed in a dry room as much as possible, and the drill rod that is not used immediately should be avoided on site.