High-precision CNC machining center is a milling machine that automatically processes workpieces by sending digital quantities as instruction information from the digital control system. In the entire digital control system, operations such as spindle start and stop, spindle speed change, advance and retreat of the tool, and the relative displacement of the tool and the workpiece are digitally represented, which greatly improves the stability of the entire machining process, thereby improving the machining accuracy of CNC milling. reducing the machining error. However, due to the accuracy of the CNC machining center itself and the control error in the machining process, the machining accuracy will decrease, resulting in the phenomenon of machining out of tolerance. So what are the factors that cause the machining accuracy to decrease due to the CNC machining center’s own components? Here is a brief introduction for you:
- Error of high-speed electric spindle of high-precision CNC machining center
The spindle speed reaches more than 8,000 rpm, and the spindle of some high-speed CNC machining centers is as high as more than 20,000 rpm. Therefore, the configured spindle is not an ordinary spindle, but a high-speed, high-precision motorized spindle. The internal structure of the spindle is very complex, involving There are various parts and components. If you do not pay attention to maintenance during use, it is easy to cause some problems. If the gap is too large or vibration occurs, there will be large errors in the roundness and accuracy of the processed workpiece during high-speed rotation processing. . - Ball screw error of high precision CNC machining center
The ball screw is the key component that directly drives the table to move. If the ball screw has free clearance and other problems, it will cause the table to move inaccurately, especially when the table is fed forward and backward. The free clearance error performance of the ball screw more obvious. As a result, the positioning accuracy and repeated positioning accuracy of the worktable are deviated, which affects the machining accuracy. The supply and cleanliness of lubricating oil must be guaranteed when the ball screw is fed under load, which is the focus of inspection during normal maintenance. - Error of servo control system of high precision CNC machining center
The servo control part is the power output of the entire machine tool, including the spindle drive part and the feed drive, mainly composed of a driver and an AC servo motor. The spindle drive part is the guarantee for the power output of the spindle. If there is a problem with this part, it will directly lead to the decline of the spindle accuracy. The feed drive drives the feed of the worktable through the ball-type bar. After a problem occurs, it directly affects the positioning accuracy and repeatability of the worktable. If there is a problem with the positioning accuracy, the machining accuracy will not be talked about. - Guide rail error of high precision CNC machining center
The guide rail is the carrier of the worktable and the workpiece, and its importance can be imagined. The quality and supply of lubricating oil must be normal in the normal work of hard rail sticking plastic. Usually, attention should be paid to check the cleanliness of the rails, and prevent debris such as iron filings from scratching the rail surface. High-speed and heavy-duty linear guides are widely used in some CNC machining centers with high machining accuracy due to their small friction coefficient and accurate positioning. Otherwise, it may cause damage and cause the machining accuracy to exceed the standard.
