Which one of the hard and linear rails of a cnc machining center is better?
Release time: 2020-01-03 10:32:09
Generally, cnc machining centers are assumed to be used for products, and they purchase linear rails. If they are processing molds, they buy hard rails, which have higher accuracy than hard rails, but hard rail cnc machining centers are more robust.
Hard Track Features
I. Benefits of hard rail cnc machining centers:
1. It can accept larger loads and is suitable for roughing machine tools with large tool volumes and large feeds.
2. Due to the large contact area of the guide rail, the operation of the machine tool is more stable, which is suitable for machine tools with high requirements on machine tool oscillation, such as grinding machines.
Disadvantages of hard rail cnc machining centers:
1. The material is not uniform. Because casting is generally formed, casting defects such as sand inclusion, porosity, and looseness occur briefly in the material guessing. If these disadvantages exist on the guide surface, the service life of the guide rail and the accuracy of the machine tool are unlucky. .
2. It is difficult to process. Since this type of guide is generally connected with the main components of the machine tool such as the base, column, work table, slider, etc., during the processing process, its shape and position are required to be used for service, and the roughness is required. Aging, quenching and other processes are difficult to control, and then the quality of the parts cannot reach the requirements of the equipment.
3. The equipment is very difficult. The word "equipment" means both installation and matching. The process of matching is a process that combines skills and physical strength. It is not something that ordinary workers can complete, and the relative number of skills required. The equipment workers who have a proper grasp of the overall accuracy of the machine tool are adjusted. They also need to be equipped with a shovel, a square ruler, a square ruler, a square ruler, a dial indicator, a dial indicator and other corresponding things.
4. The service life is not long. This can only be relatively speaking. Under the same maintenance and application conditions, the service life of a wide range of hard rails is less than the service life of a linear rail, which is similar to their exercise methods. For a large connection, the hard rails slide and interfere, and the linear rails roll over and interfere. From the standpoint of the resistance, the hard rails are far more resistant than the linear rails. Especially, In the case of insufficient smoothness, the resistance of the hard rail is even more.
5. The repairing cost is too high. The repair of the hard rail is much more expensive than the repair of the linear rail no matter how difficult it is. It is assumed that in the case of lack of scraping margin, it may involve the separation of all the large parts of the machine tool. After re-hardening and machining, the large piece may be re-casted, and the wire gauge only needs to replace the corresponding wire rail, which basically does not greatly affect the use of related large pieces.
6. The working speed of the machine tool is low. Hard rails generally cannot accept excessively fast working speeds due to their moving methods and excessive resistance, which is inconsistent with the current processing concept. In particular, workers in many factories do not have the corresponding maintenance knowledge of machine tools. Many hours they only know how to use machine tools, but they largely ignore the maintenance of machine tools. The maintenance of machine tool tracks is the top priority. Once the track is smooth and insufficient, Will cause burnout or wear transitions, which are loss of life to the accuracy of the machine tool.
Line rail features
First, the benefits of linear CNC machining center
1. The cnc machining center is simple and convenient, and only a little practice can complete high-quality equipment. Because the accuracy of cnc machining center machines is so high, the accuracy of the transmission arrangement is determined. The transmission arrangement is generally composed of wire rails and screw rods. That is to say, the accuracy of the wire rails and the screw rod itself determines the accuracy of the machine tool, and the line rails And the screw rod generally exists as a standard piece method, you only need to choose the corresponding accuracy provided by the manufacturer, and generally there will not be a big problem.
2. There is a lot of room for choice. Whether it is the structural method of the line rail or the accuracy level, the smooth method is still load-bearing talents, the processing method to the operating speed and other parameters can be selected. You can choose according to the specific situation of your planned machine tool. Intentionally configure the type of rail you need.
3. The working speed is fast. Nowadays, the operating speed of many machine tools is extremely fast, especially the idling speed. This is largely due to the credit of the line rail. Due to the conflicting operation method and high-precision processing, it is truly guaranteed. The accuracy and smoothness of the high-speed operation of the machine tool have greatly improved the processing power and processing accuracy.
4. High machining accuracy. As the wire rail is a standard product, both the material and the processing method have entered a benign and controllable scale. Therefore, most of the machine tools in the field of precision machining use high-precision wire. The rail is used as the guide rail of the machine tool, which also greatly ensures the machining accuracy of the machine tool. The domestic technology has done well in Nanjing technology, the Hanjiang line rail, Taiwan has the silver line rail, Germany has Rexroth, Japan has THK line rail, etc. These brands are extremely rich and meet the needs of the mall for various requirements of the line rail. Personally, I prefer to use the Japanese THK, with stable functions and precise workmanship, because the price is high.
5, using long life, because the operating method of the line rail is rolling and resisting, the steel ball in the slider is driven by the rolling on the track to drive the movement of the feeding component. The resisting force accepted by such rolling and resisting is smaller than that of the hard rail. There are many more, so whether the power is transmitted or the service life is used, the line rail is much better than the hard rail.
6. The repair cost is low. Regardless of the repair cost and convenience of repair, the rail has its natural advantages and convenience. As a standard part, the replacement method of the rail is the same as replacing a screw. Of course, there are still some adjustments in the reply, but in terms of hard tracks, it is really convenient.
7, the delivery cycle is short, the general delivery cycle of the rail can be completed within half a month, unless you choose foreign brands, such as Rexroth and THK, in fact, these two brands also have corresponding processing plants in China As long as the type of rail you choose is not very biased, basically the delivery period of about half a month can still be guaranteed, and the line rail of Taiwan Shangyin can even achieve a one-week delivery cycle, but The same hard track does not have such a good time to control talent. Assuming that the action is relatively large, such as recasting, the cycle may be uncertain for more than a few months.
Second, the shortcomings of the line rail
1. The carrying capacity is relatively small. This relatively small size is only for hard rails. In fact, the rails of many large factories have undergone some structural planning, and their carrying talents have been greatly improved. In terms of bearing capacity, rails are still relatively small.
2. The stability is relatively weaker than the hard rails, such as the ability to resist oscillation. However, I still want to focus on this kind of weakness, which is relative to the hard rails. In fact, the smoothness of many line rails is also Very well done, as long as the equipment you plan is not a special requirement for overheating, generally it can meet the demand.
3. Pay special attention to the maintenance of the line rail during the transportation and equipment process. Because of its unique structural characteristics as a standard part, it is in an awkward position where it is relatively briefly damaged, such as the slender shape and then the line The rigidity of the rail is lacking, and it simply bends and deforms during kneading, which then leads to loss of accuracy; for example, because it is a steel part, it is assumed that the rust prevention treatment has not been performed, and it has been exposed to water or other solvents during transportation and equipment. Phenomena such as rust and corrosion occur briefly, and then the accuracy is lost.