The so-called CNC machining is also known as CNC machining, which refers to a kind of processing which is operated by CNC machining operators after the programmer uses the computer to program the work order to be processed. There are three kinds of guide rails for CNC machining center. The differences between these three kinds of guides are quite big. Therefore, if you need to select the guide rails of CNC machining centers, it is better to have a detailed understanding of these three kinds of guides in advance, so that we can better select the guide rails for our CNC machining centers. The following is an introduction to the guide rails of CNC machining centers:
According to the motion track, the guide rail can be divided into linear motion guide rail and circular motion guide rail; according to the working nature, it can be divided into main motion guide rail, feed motion guide rail and adjustment guide rail; according to the friction property of contact surface, it can be divided into sliding guide rail, rolling guide rail and hydrostatic guide rail.
Slide guide
The sliding guide has the advantages of simple structure, convenient manufacturing, good stiffness and high vibration resistance. The traditional cast iron cast iron and cast iron quenched steel guide rail has the disadvantages of large static friction coefficient, dynamic friction coefficient changes with the speed, and the friction loss is large. It is easy to crawl at low speed / (1-60mm / min /), which reduces the positioning accuracy of moving parts. Therefore, it is not used in other CNC machine tools except economical CNC machine tools.
At present, most CNC machine tools use plastic guide, that is, a layer of plastic film soft belt composed of plastic and other chemical materials is pasted on the friction surface of moving guide rail.
There are two kinds of guide rail Plastics: PTFE soft belt and epoxy wear-resistant rail coating. The characteristics of plastic sliding guide are good friction characteristics, good wear resistance, smooth movement, good vibration damping and good technology.
Rolling guide
Rolling guide is to place ball, roller, needle and other rolling elements between the guide surfaces, so that the sliding friction between the guide surfaces becomes rolling friction. Compared with sliding guide rail, rolling guide has the advantages of high sensitivity and little difference between dynamic friction coefficient and static friction coefficient, so it can move stably, and it is not easy to crawl when moving at low speed; (high positioning accuracy, repeated positioning accuracy can reach 02um; low friction resistance, light movement, small wear, good accuracy retention and long service life. However, the anti vibration performance of rolling guide is poor, which requires high protection.
The rolling guide rail is especially suitable for the working parts of machine tools requiring uniform movement, sensitive motion and high positioning accuracy. This is the reason why rolling guide is widely used in CNC machine tools.
Hydrostatic guideway
There is an oil cavity between the two working faces of the hydrostatic guideway. After the lubricating oil with certain pressure is injected, the hydrostatic oil film can be formed, so that the working surface of the guide rail is in pure liquid friction, without wear, and has good accuracy retention; at the same time, the friction coefficient is also very low, which greatly reduces the driving power; at low speed, there is no creeping, the bearing capacity is large, and the rigidity is good; In addition, the oil has the function of vibration absorption and good vibration resistance. Hydrostatic guideway can be divided into hydrostatic guideway and aerostatic guideway.
Its disadvantage is that the structure is complex, there must be an oil supply system, and the cleanliness of the oil is required to be high. Hydrostatic guideway is widely used in machine tools. The hydrostatic guideway of CNC turret punch press can be divided into open type and closed type
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