The difference of the three guide rails of cnc metal milling machine:
There are mainly three kinds of guide rails for cnc metal milling machine, and the difference between these three kinds of guide rails is relatively large, so if you need to select the guide rails of the cnc machining center, it is best to have a detailed understanding of these three guide rails in advance, so that you can better I have chosen the guide rails for my cnc machining center. The following is an introduction to the guide rails of the cnc machining center:
The guide rails can be divided into linear motion guides and circular motion guides according to the motion track; according to the nature of work, they can be divided into main motion guides, feed motion guides and adjustment guides; according to the nature of the touch surface, they can be divided into sliding guides, rolling guides and static pressure 3 kinds of guide rails.
1. Sliding rail
The sliding guide rail has the advantages of simple structure, convenient manufacturing, good rigidity and seismic resistance. Traditional cast iron-cast iron, cast iron-quenched steel guide rails have the disadvantage of large static interference coefficient, and dynamic interference coefficient changes with speed, large interference loss, and creeping phenomenon at low speed/(1-60mm/min/) , And then reduce the positioning accuracy of the moving parts, so in addition to economical CNC machine tools, it is no longer used on other CNC machine tools.
At present, most CNC machine tools use plasticized guide rails, that is, a layer of plastic film soft tape composed of plastic and other chemical materials is pasted on the contradictory surface of the movable guide rail.
The guide rail plastics are commonly used in two types: PTFE guide rail soft belt and epoxy wear-resistant guide rail coating. Plastic sliding guide rails are characterized by good resistance, good wear resistance, smooth movement, good shock absorption and good manufacturability.
2. Rolling rail
Rolling guide rails are to place rolling bodies such as balls, rollers, and rollers between the guide rail surfaces, so that the sliding resistance between the guide 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 the dynamic and static resistance coefficients is very small, so the movement is stable, and the crawling phenomenon is not easy to appear when moving at low speed; (high positioning accuracy, repeat positioning accuracy can reach 02um; small resistance, easy movement, low wear, good precision persistence and long life. However, the anti-vibration of the tumbling rail is poor, and the requirements for protection are high.
The rolling guide rail is especially suitable for the occasions where the working parts of the machine tool require uniform movement, flexible movement and high positioning accuracy. This is the reason why the roll guide is widely used on CNC machine tools.
3. Hydrostatic guide rail
Static pressure guide rails can be divided into hydrostatic pressure guide rails and gas static pressure guide rails.
There is an oil cavity between the working surfaces of the two guide rails of the hydrostatic guide rail. After the lubricating oil with a certain pressure is passed in, a static pressure oil film can be formed to make the guide rail work surface in pure liquid interference, no wear, and good precision persistence; At the same time, the interference coefficient is also extremely low, which greatly reduces the driving power; low speed, no crawling, large carrying capacity, and good rigidity; in addition, the oil has a vibration absorption effect and good vibration resistance.
The disadvantage is that the structure is messy, there must be an oil supply system, and the cleanliness of the oil is required. Hydrostatic guide rails are increasingly used on machine tools.
The suitable cnc metal milling machines for these three kinds of guide rails are also different, so it is best for you to choose the suitable one based on your professional understanding.
