What Is Diamond Drilling?

Drilling refers to the operation of drilling holes in solid materials with a drill. This section describes the drilling work in the exploration work, as well as the auxiliary tools and some emergency measures needed for drilling.

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The names of each part of the drilling are shown in the figure. The starting point of the hole is called the orifice, the side is called the hole wall, and the bottom is called the hole bottom. The diameter D of the drilled hole is referred to as the hole diameter, the hole diameter is called the opening diameter, and the hole bottom diameter is called the final hole diameter. The distance H from the hole to the bottom of the hole is called a drill

The function of drilling:

Obtain first-hand underground geological material data, that is, remove cores, cores, cuttings or liquid and gaseous states from the boreholes

Drilling holes in solid material with a drill is called drilling. Hole machining of various parts

The drill bit rotates at a high speed.

Severe friction, difficult heat dissipation, high heat, high cutting temperature.

Large cutting volume, difficult chip removal, and easy to produce vibration.

The drill bit has poor rigidity and precision, so the drilling accuracy is low. The general dimensional accuracy is IT11 IT10.

First, drilling machine equipment

Commonly used drilling machine equipment are

The drill is a cutting tool for drilling. It is usually made of high-speed steel. The working part is hardened to 62-65HRC after heat treatment. Generally, the drill consists of a shank, a neck and a working part.

Shank: It is the clamping part of the drill, which plays the role of transmitting power. There are two types of shank: straight shank and taper shank. Straight shank has a small transmission torque. It is generally used for drills with a diameter less than 12mm. Torque (mainly the flat tail part of the handle) is used for drills with a diameter greater than 12mm.

Neck: It's a grinding wheel

For drilling

accurate

The control of the position accuracy of the drilling is essentially a process of controlling the mutual correct position of the drill and the workpiece during the drilling process. In order to evaluate the operator's operating skills, it is required that the adjustment of the hole position can only be performed manually and dynamically during the drilling process. The use of drilling dies and other fixtures is not allowed. Therefore, the accuracy of the hole position is affected by scribing, machine tool accuracy, workpiece and drill bit accuracy. Clamping, bit grinding quality, workpiece position and

Reaming

Reaming is used to enlarge the machined hole (cast, forged or drilled hole), it can correct the deviation of the axis of the hole, and make it obtain the correct geometry and smaller

In addition to the grade of the material and the geometry of the drill bit, the main reasons for the break of the drill bit are as follows:

driller

The vibration of the drill itself and the swing of the drill shaft basically decrease with the decrease of the diameter of the drill pin. In half, the vibration requirements are below 0.1 microns when the diameter of the drill is 0.1-0.3 mm, and the amplitude is below 10 microns when the diameter of the drill is 0.35-0.5 mm. At the same time, from the viewpoint of productivity, the drill When the diameter is reduced, the speed of the drill shaft must be relatively increased. Although the high speed drill shaft has developed to 80

. Spindle speed

(RPM) Basically, the rotation speed of the drill shaft is calculated from the circumferential speed of the drill bit. From the perspective of productivity and tool life, there is a suitable speed range. For ordinary diameter drill bits, it is 100-200 m / min. But for ultra-small diameter drills, this speed

operation

Drilling accidents are the biggest obstacle to improving drilling efficiency and reducing costs. Therefore, it must be prevented to minimize the incidence of accidents. And after the accident, it can be correctly handled in time.

Experience has shown that although there are objective reasons for the occurrence of drilling accidents, as long as they are subjectively valued, they will implement various operating procedures in the work, master the technology, earnestly operate, and take effective preventive measures at any time. .

Drilling workers should be familiar with the causes of various hole accidents and the warning signs before they occur, so that they can be prevented in their work. In the event of an accident and its occurrence, the cause of the accident and the current situation in the hole should be clarified first, as long as the cause of the accident and the situation in the hole can be grasped before handling. Don't engage blindly to avoid improper handling and repeated accidents, which will increase the severity and complexity of the problem.

There are usually drilling tool retention accidents, drilling tool breakage accidents, and holes falling into tool iron parts accidents during drilling.

Type I: Drilling tool retention accidents

stuck: Any phenomenon that the down pipe string and tools cannot be lifted, lowered or rotated in the well.

Clamped drill: That is, the large-diameter drilling tool is sandwiched between the hole wall or the casing by the coarse particles of the drill or hard rock. come out.

Buried drill: refers to the hole section in the upper part of the borehole collapsed during drilling, and the drilling tool is buried at the bottom of the hole.

Dredging drill: It means that a large amount of fine-grained rock powder or quicksand fills up and around the drilling tool, and the drilling tool is blocked, and the water cannot be drilled when the water is stopped.

Burning drill: refers to the lack of water during drilling, the bottom of the large-diameter drill tool becomes hot, and sinters with the hole wall, and cannot be pulled out.

Type II: Drilling tool break accident

The breakage of the large-diameter drilling tool means that the thread of the drill pipe joint at the three-purpose joint is broken during drilling; the thread of the core pipe is disconnected or tripped; A part of the large-diameter drill is dropped at the bottom of the hole.

Broken drill pipe means that when drilling or handling other drilling accidents, due to excessive force, the drill pipe or drill pipe joint is broken, and the drilling tool is dropped at the bottom of the hole.

Category III: Tools and iron parts fall into drilling accidents

This type of accident refers to the fall of tools or iron parts on the drilling site into the borehole, which affects drilling and drilling.