Advantages and disadvantages of cnc processing different guide rails

There are three main guide rails for cnc machining centers. According to the conflicting nature of the touch surface, they can be divided into hydrostatic guide rails, sliding guide rails, and rolling guide rails. The difference between these three guide rails is quite big. Understand, the following editor will briefly introduce their advantages and disadvantages.

　　 The advantages of the three are as follows:

1. There is an oil cavity between the working surfaces of the two guide rails of the hydrostatic guide rail. After a certain pressure of lubricating oil is passed into it, a static pressure oil film can be formed, so that the guide rail working surface is in pure liquid interference, no wear, and precision persistence Good; at the same time, the interference coefficient is also extremely low, which greatly reduces the driving power; low speed, no creep, great load-bearing ability, and good rigidity; in addition, the oil has a vibration absorption effect and good vibration resistance. Static pressure guide rails can be divided into hydrostatic pressure guide rails and gas static pressure guide rails.

　　2, the sliding guide has the advantages of simple structure, convenient manufacturing, good rigidity and vibration resistance. Rail plastics are commonly used in two types: PTFE rail soft tape and epoxy wear-resistant rail coating. Plastic sliding guide rails are characterized by good resistance, good wear resistance, smooth movement, good vibration damping and good manufacturability.

　　3. Rolling rail is to place rolling bodies such as balls, rollers, and needles between the rail surfaces, so that the sliding resistance between the rail surfaces becomes a rolling resistance. Compared with sliding guide rails, the advantages of rolling guide rails are: high degree of flexibility, and the difference between dynamic and static resistance coefficients is very small, so it moves smoothly, and it is not easy to crawl when moving at low speed; (high positioning accuracy, repeat positioning accuracy can be Up to 02um; small resistance, easy movement, low wear, good precision persistence, and long life. However, the anti-vibration of the rolling guide is poor and requires high protection.

　　 What are the shortcomings of the three?

　　 1. The defect of the static pressure guide rail is that the structure is messy, the oil supply system is required, and the cleanliness of the oil is required. Hydrostatic guide rails are increasingly used in machine tools. The hydrostatic guideway of CNC turret punch press can be divided into two categories: open type and closed type.

2. The defect of the sliding guide rail is that the static resistance coefficient is large, and the dynamic resistance coefficient changes with the speed change, the resistance loss is large, and the crawling phenomenon is easy to occur at low speed/(1-60mm/min/), and then the positioning accuracy of the moving parts is reduced. Therefore, except for economical CNC machine tools, it is no longer used on other CNC machine tools. Nowadays, most CNC machine tools use plasticized guide rails, that is, a layer of plastic film soft tape made of plastic and other chemical materials is pasted on the contact surface of the moving guide rail.

　　3. The defect of the rolling guide is that the damping is small and simple to cause overshoot or vibration, the rigidity is low, the manufacturing is difficult, and it is more sensitive to dirt and rail surface errors. The rolling guide rail is especially suitable for the occasions where the operating parts of the machine tool require uniform movement, flexible movement and high positioning accuracy.