Why do high precision CNC machining centers have errors? You should pay attention to these four reasons!

High precision CNC The machining center is a milling machine that automatically processes the workpiece by using the digital quantity sent by the digital control system as the instruction information . Start and stop the spindle in the whole digital control system 、 Spindle speed change 、 Advance / retreat knife 、 The relative displacement between the tool and the workpiece is represented by digitization , Greatly improve the stability of the whole processing process , Thus, the machining accuracy of NC milling is improved , Reduced machining error . however , Due to the existence CNC The accuracy of the machining center itself and the control error in the machining process , The machining accuracy will decrease , Cause processing out of tolerance , So because of CNC What are the factors that cause the decline of machining accuracy of the machining center itself ？ Here is a brief introduction to ：

One 、 High precision CNC Machining center high speed motorized spindle error

The spindle speed reaches 8000 Turn above every minute , Some high speed CNC The spindle of machining center is as high as 2 Ten thousand turns , Therefore, the configured spindle is not an ordinary spindle , It's high speed 、 High precision motorized spindle , The internal structure of the spindle is very complex , There are a variety of parts involved , If you don't pay attention to maintenance during use, it is easy to have some problems , If there is too much clearance or vibration , In high-speed rotary machining, roundness of the workpiece will appear 、 There is a large error in accuracy .

Two 、 High precision CNC Machining center ball screw error

Ball screw is the key component that directly drives the workbench to move , If the ball screw has problems such as free clearance , It will cause inaccurate movement of the workbench , In particular, the free clearance error of the ball screw is more obvious when the worktable is fed forward and backward . As a result, there is a deviation between the positioning accuracy of the workbench and the repeated positioning accuracy , Affect machining accuracy . The supply and cleanliness of lubricating oil for ball screw during load feeding must be ensured , This is the key point of inspection during normal maintenance .

3、 ... and 、 High precision CNC Machining center servo control system error

The servo control part is the power output of the whole machine tool , Including spindle drive part and feed drive two parts , It is mainly composed of driver and AC servo motor . The main shaft drive part is the guarantee of the main shaft power output , If there is a problem with this part , It will directly lead to the decrease of spindle accuracy . The feed drive drives the feed of the worktable through the ball screw , The problem will directly affect the positioning accuracy and repeated positioning accuracy of the workbench , If there is a problem with positioning accuracy, there is no machining accuracy .

Four 、 High precision CNC Machining center guide rail error

Guide rail is the carrier of worktable and workpiece , Its importance can be imagined , The guide rail type is divided into two forms: hard Rail plastic pasting and high-speed heavy-duty linear guide rail . During normal operation, the quality and supply of lubricating oil must be normal , At ordinary times, pay attention to the cleanness of the guide rail , Strictly prevent iron filings and other sundries from grinding the guide rail surface . High speed and heavy load linear guideway has small friction coefficient , Accurate positioning and other advantages , In some 、 High machining precision CNC Widely used in machining centers , Special attention should be paid to this type of guide rail , Be sure to control the load capacity of a single piece , Do not exceed the rated load , Otherwise, it may cause damage and cause the machining accuracy to exceed the standard .