What is a tooth pick?

　　Picks are mainly used in coal shearers and roadheaders, and picks are also used in some excavators and milling machines. However, different models and different construction environments require different types of picks. So, what are the commonly used pick models? What kind of working conditions and machines are they suitable for?

　　It is understood that the common pick models are S and U.

　　S class picks:

　　S-type picks are mostly used in roadheaders, subdivided models such as: S100, S200, S120, etc. These picks are suitable for the construction environment of coal and rock roadways, soft rock roadways, road tunnels, railway tunnels, etc.

　　It is worth mentioning that the pick shape of the roadheader is pick-shaped, mostly made of alloy steel and alloy with high hardness. The life of this kind of pick is determined by the material, welding quality, working conditions, etc.

　　U class pick

　　U-type picks are used on shearers, and there are more than ten kinds of specific types such as U47, U84, U85, u94|u95, etc. Moreover, according to different working conditions, the picks of coal shearers are also divided into ordinary type, super hard rock type, sandstone type and so on. These picks have undergone special treatment in the production process, such as: sandstone-type picks are added with alloy strips, wear-resistant picks have an additional wear-resistant layer, and non-spark picks are treated with plasma technology. , A wear-resistant layer of alloy material is added to the tooth body.

　　Therefore, when selecting picks, construction personnel must first understand their own construction environment and the model of the machine, and then match the appropriate picks.

　　1.3. Mining picks are subjected to high periodic compressive stress, shear stress and impact load when cutting coal and rock. Although the hardness of coal is not high, hard mineral materials such as coal gangue are often encountered in the process of cutting coal and rock. Due to friction and impact, the temperature of the pick will also increase. For picks working under such complex industrial and mining conditions, the pick body is required to be both wear-resistant and have good impact resistance. The pick is mainly composed of a pick handle, a pick head, and an alloy cutter head. The pick handle and the pick head are often called the pick cutter body. There are many types of mining picks, and the general structure is to insert a hard alloy cutter head on a quenched and tempered low alloy structural steel cutter body.

　　1.4. Coal shearer: The coal shearer is a large and complex system integrating machinery, electricity and hydraulic pressure. The working environment is harsh. If a failure occurs, the entire coal mining operation will be interrupted, resulting in huge economic losses.

　　1.4.1. Saw-cut coal shearer - also called coal cutter, cuts coal by cutting teeth installed on the circularly moving cutting chain deep into the coal wall.

　　1.4.2. Planing coal shearer—that is, a coal plow, which plans and breaks coal by the reciprocating motion of the planer.

　　1.4.3. Drilling shearer--drill into the coal body by the cutter teeth on the edge of the drill bit, and break the coal body in the middle by the coal breaking cutter teeth in the middle of the drill bit.

　　1.4.4. Percussive shearer-according to the stress characteristics and mechanical characteristics of the coal wall, make full use of the mechanical characteristics of the weakest tensile strength of the coal rock, and use the cutter parallel to the coal wall of the working face to punch the coal body A coal mining device that causes the cutter to touch and rush into the coal body to generate a splitting tensile stress in the coal body, causing the coal body to crack and fall.

　　1.5. Tunneling machine: Tunneling machine is a machine used to excavate straight underground roadways. The roadheader is divided into open type roadheader and shield type roadheader. The price generally ranges from 2 million to 8 million yuan. It is mainly composed of walking mechanism, working mechanism, shipping mechanism and reloading mechanism. As the traveling mechanism advances, the cutting head in the working mechanism continuously breaks the rock and transports the broken rock away. It has the advantages of safety, high efficiency and good lane quality, but the cost is high, the structure is complicated, and the loss is also large.

　　1.6. Rotary excavator: It is a tool for road traffic and high-rise building construction. The rotary excavator is a comprehensive drilling rig, which can be used for dry excavation with a short auger bit, or wet excavation with a rotary bit for mud protection. The rotary excavator can cooperate with the hammer to drill the hard stratum and carry out the hole digging operation. If it cooperates with the reaming drill, the reaming operation can be performed at the bottom of the hole. The rotary excavator adopts multi-layer telescopic drill pipe, which has less auxiliary drilling time, low labor intensity, no need for mud circulation and slag discharge, cost saving, and no pollution. It is especially suitable for the foundation construction of urban construction.