Machining center set oil, gas, electricity, numerical control as one, can achieve a variety of disc, plate, shell, CAM, mold and other complex parts of the workpiece clamping, can complete drilling, milling, boring, expanding, reaming, rigid tapping and other processes processing, so it is the ideal equipment for high-precision processing, this article will share from the following aspects of the use of processing center skills:
1.Return to zero (return to the origin of the machine)
Before the knife, be sure to return to zero (return to the origin of the machine) operation, in order to clear the coordinate data of the last operation. Note that the X, Y, and Z axes all need to return to zero.
2.The main shaft is turning
With the “MDI” mode, the spindle is turned forward by entering the command code, and the moderate rotation speed is maintained. Then it is changed to the “hand wheel” mode, and the operation of machine tool movement is carried out by changing the speed of adjustment.
3.Align the knife in the X direction
Gently touch the tool on the right side of the workpiece to clear the relative coordinates of the machine tool; Lift the tool along Z direction, then move the tool to the left side of the workpiece, down along Z to the same height as before, move the tool to touch the workpiece gently, lift the tool, record the X value of the relative coordinate of the machine tool, move the tool to half of the relative coordinate X, record the X value of the absolute coordinate of the machine tool, and press (INPUT) input coordinate system.
4.Align the knife in the Y direction
Gently touch the front of the workpiece with the tool to clear the relative coordinates of the machine tool; Lift the tool along Z direction, then move the tool behind the workpiece, down along Z to the same height as before, move the tool to touch the workpiece gently, lift the tool, record the Y value of the relative coordinate of the machine tool, move the tool to half of the relative coordinate Y, record the Y value of the absolute coordinate of the machine tool, and press the coordinate system INPUT.
5.Knife in the Z direction
Move the tool to the surface of the workpiece to the z-zero, slowly move the tool until it is in slight contact with the upper surface of the workpiece, record the Z-value in the coordinate system of the machine tool at this time, and press the coordinate system INPUT.
6.Spindle stop
First stop the spindle rotation, and move the spindle to the appropriate position, access the processing program, ready for formal processing.
For the parts with light quality, poor rigidity and weak strength, they are easy to be stressed and deformed during processing, and the high processing scrap rate leads to a substantial increase in cost. For such parts, we must first understand the causes of deformation:
– Stress deformation:The wall of such parts is thin, and under the action of clamping force, it is easy to have different thickness during machining and cutting, and the elasticity is poor, and the shape of the parts is difficult to recover by itself.
– Heat deformation: the texture of the workpiece is thin, and the heat deformation of the workpiece will be caused by the radial force during the cutting process, so that the size of the workpiece is not accurate.
– Vibration deformation: Under the action of radial cutting force, parts are prone to vibration and deformation, affecting the dimensional accuracy, shape, position accuracy and surface roughness of the workpiece.
– Processing method of deformable parts: The deformable parts represented by thin-wall parts can adopt the form of high-speed machining cutting with small feed amount and large cutting speed to reduce the cutting force on the workpiece during processing, and at the same time make most of the cutting heat be taken away by the chip flying away from the workpiece at high speed, thus reducing the temperature of the workpiece and reducing the thermal deformation of the workpiece.
CNC tool is not the faster the better, why should passivation treatment? In fact, tool passivation is not a literal meaning, but a way to improve the service life of the tool. Improve tool quality by leveling, polishing, deburring and other processes. This is actually a normal process after the tool is polished and before the coating.
Surface roughness is one of the common problems in CNC machining centers, which directly reflects the machining quality. How to control the surface roughness of parts processing, we must first in-depth analysis of the causes of surface roughness, mainly including: cutting marks caused by milling process; Heat deformation or molding deformation caused by cutting separation; Friction between the tool and the machined surface.
When the workpiece surface roughness is selected, it should not only meet the surface function requirements of the parts, but also consider economic rationality. Under the premise of meeting the cutting function, a larger reference value of surface roughness should be selected as far as possible to reduce production costs. As a cutting center, the tool should pay attention to daily maintenance and timely grinding to avoid the surface roughness caused by the tool being too blunt.
Machining center traditional machine tool processing procedures in general is roughly the same, the most important difference is that the machining center is through a clamping, continuous automatic processing to complete all cutting processes, so the machining center after the completion of CNC machining to carry out some “afterwork.”
1.Cleaning treatment, machining center after the completion of the cutting task to remove chips in time, wipe the body, the use of machine tools and the environment to maintain a clean state.
2.The inspection and replacement of accessories, first of all, pay attention to check the oil rub plate on the guide rail, and replace it in time if wear occurs. Check the status of lubricating oil and coolant, if turbidity occurs, it should be replaced in time, and it should be added below the scale water level.
3.The shutdown procedure should be standardized, and the power supply and the total power supply on the operation panel of the machine tool should be turned off in turn. In the absence of special circumstances and special requirements, the principle of first return to zero, manual, point, automatic should be followed. Machining center operation should also first low speed, medium speed, and then high speed. The running time of low speed and medium speed shall not be less than 2-3 minutes, and no abnormal conditions can be started.
4.Standard operation, can not punch, correct, correct the workpiece on the chuck, the center, must confirm the workpiece and the tool clamping before the next operation. The safety and safety protection device on the machine tool shall not be arbitrarily disassembled and moved. The most efficient processing is actually safe processing, and the operation of the processing center as an efficient processing equipment must be reasonable and standardized, so that it is not only the maintenance of the current completed process, but also the preparation for the next start.
