Drills are tools used to drill holes in different materials and widen the drilled holes. There are two main drilling methods performed with a drill. The first method is the hammer drilling method used mostly in mining or drilling. In this method, the digger moves forward by crashing into the environment drilled with the blows it receives. This progress takes place in a discrete manner, by removing the piece from the ground with the blows hit. The second, more commonly known method of drilling is the rotary drilling method. In this method, rotating cutting tools drill the relevant material by cutting and grinding.
In impact drilling; the feed rate depends on the impact force, the number of impacts corresponding to the rotation of the drill, as well as the impact frequency. The drilling tool performs discrete rotation motion at certain intervals independently to ensure that the feed travels along the axis. It is mostly used in mining or soil drilling.
In rotary drilling, the wear problem for the tool tip is more important than impact workers. Abrasion depends on the feed rate, pressing force and amount of water and oil sent to the drilling zone at each turn.
Drill Types According to the Places of Use
Drills are divided into two basic parts according to their usage areas: workshop drills, mine drills. Workshop drills are the most commonly used rotary drills in the home, workshop and industry. Although these are generally helical drill bits, there are also flat tip types used in carpenter workshops. Mining drills are drills that can be of various types, impact or rotary, used for drilling soil and hard rocks for mining or drilling.
A workshop drill has three main parts, the tool system, the part system, and the body. The body can be portable in small hand drills, but it may also have to be rigid and large on heavy benches. Track system, where the part is connected It covers the mechanism that will control and drive it if the table and the table are mobile. The table is driven manually or mechanically. The drilling tool and the table to which the part is attached can be driven from only one motor, and sometimes they can also be driven from two separate motors.
The main basic system of the machine is the tool system. Small portable drills only have this system. Apart from the engine, the chuck that holds the main parts of the drill bits is a simple gear system that reduces the engine speed to the appropriate speed for the drill.
Drill drilling tools are the basic part of the drill. Rotary drill tools can be of either flat or helical type. It is preferred only in small diameter holes with a soft material, since the sharpening of the bits used in the flat drill set is arduous and requires considerable force for advancement. Generally used rotary drill sets are drill sets called helical. There are openings on the body, which is the main part of the team. The team may also have more than one mouth. The mouth is in the form of straight or helical opened channels. The sawdust removed in the hole drilled in this way is transmitted from these channels to the material surface by going through these channels and thrown out. The most commonly used material in drill tools is the high alloy steel type called speed steels. Tools made from this material can be used at higher cutting speeds and temperatures than those made from normal steels. The cheap drills preferred in home workshops are made of carbon steel. There are many types of workshop drills, including electric hand drills, vertical, radial, horizontal drills and multi-spindle special drilling machines:
1. Hand drills or portable drills: Such portable drills, produced in the form of pistols, are often used for drilling small holes or for drilling in places other than metal, such as plastic and wood. In some types used in carpenter workshops, the act of driving is done manually.
2. Vertical drill benches: There are types such as table drill, column drill, foot drill and coordinate drill bench. Drilling is done by fixing the part to the workbench table. The drilling tool is rotated by the electric motor on the bench.
For highly precise or mixed drilling operations, coordinate hole benches are used. These are generally numerically controlled machines. In these benches, which are very rigid in structure, the drill spindle moves only in the vertical direction, and the table to which the part is connected moves in a vertical and horizontal direction in two directions with automatic control. The speed and progress of this movement can be controlled precisely, optically, electrically or servo (hydraulically).
3. Radial boring machines: They are used to perform all kinds of boring and machining work, usually to drill holes between 30 and 80 mm in diameter. Contrary to the vertical variant, the location of the workpiece is fixed on radials. The adjustment is made by adjusting the position of the drill spindle. In this way, even large parts can be easily drilled.
5. Multi-spindle special hole machines: These kinds of machines are used in mass production. They have a large number of heads used for tool clamping, allowing multiple holes on one or several pieces to be drilled and machined simultaneously by installing different tools at the same time, saving time.
These are generally preferred drills for drilling rock and soil floors and mining. Depending on the truck, they can be mobile or installed platforms for deep drilling. Its main types are gear, impact and rotary miner drills.
1. Impact mining drill: Impact drilling is a slower way compared to rotary drilling, although it is preferred in many places, especially for not very deep drilling operations. In principle, the tool connected with a cable or rod is transmitted one after the other and the drilling is performed by rotating the tool between the pulses. The drill makes tool progress at each stroke. Pneumatic hammer drills are often chosen for impact drilling. The tools used can be in the form of rods or tubes. The tips used in the digger bar tools are usually made of tungsten carbide or coated. The bits of hollow tubular rock drilling drills are embedded in the tool and contain abrasive hard material particles.
2. Mining drill with backhoe gear set : In this type of drill used for hard rocks, the backhoe gear set achieves a satisfactory drilling rate and is used for jobs where no precise drilling is required. In the gear sets, three rotating backhoe gear wheels are mounted on the end of the drill set with bearings. The appearance of the digging teeth is in the form of sharp-edged teeth. Surfaces on rotating threaded ends, with tungsten carbide to reduce wear here and prolong life It coated.
3. Rotational mining drill: This type of drill using rotary drilling method has two types as helical and bucket. In helical mine type drills, the rod is added as the hole deepens. During the process, the sawdust is stopped and the chip is cleaned. Here the diluted mud is pulled up by a pump. With the help of the helical mouth at the mouth of the bucket type bucket, the bucket is filled at the end of one or two turns and pulled upwards and emptied. It is widely used in drilling because it is suitable for drilling not only vertically but also in every direction. This method is also used in mines.
General Culture Encyclopedia
Author: Murat Güven