What is the cause of the spherical error in the CNC machining center?
Although the CNC machining center can say that it can produce a good machining effect for general parts,it is rare for the machining of precision parts and complex shapes.However,for the processing of spherical objects,errors often occur.Why do you have a shoulder,a shovel,etc?Why?
1,the system gap caused
In the transmission pair of equipment,there is a certain gap between the screw and the nut.As the running time of the equipment increases,the gap gradually increases due to wear.Therefore,the corresponding clearance compensation for the reverse movement is overcome.The main factor in the processing of the surface to create a shoulder.Gap measurements are usually measured using a dial gauge and require control errors.However,it should be noted that the watch base and the watch stem should not be extended too long,because in the process of measurement,because the cantilever is long,the watch base is easily moved by force,resulting in inaccurate counting and error in the compensation value.
2,improper tool selection
The tool removes material through the main cutting edge during cutting.However,after the arc has been processed through the quadrant,the minor cutting edge may be involved in the cutting after the arc is tangent to the cutting edge of the tool.Therefore,when selecting or grinding a tool,the wedge angle of the tool must be carefully considered.
3,the workpiece processing allowance is uneven
In the process of realizing the design of the part,whether the machining allowance of the surface to be machined is uniform is also an important reason for the forming surface to meet the design requirements.Because the machining allowance is uneven,it is easy to cause"replication"error.Therefore,for parts with high surface shape requirements,the machining allowance should be as uniform as possible before molding or by multi-machining a profile to meet the design requirements.
The requirements for spherical machining parts are very high,and it is necessary to use a large numerical control vertical car.The cost is relatively high.If there is still an error,it will undoubtedly result in greater cost.Therefore,Xiaobian gives you the following methods for eliminating the spherical aberration of CNC machining:
During the processing of the spherical surface and the curved surface,the sphere may have a large middle or small head,or a small middle and small head.In this case,the sphere radius value needs to be controlled.If the middle is large and the two ends are small,you need to increase the radius slightly.If the middle is small and the two ends are large,this reduces the radius value.Try to control the ball error within 0.05mm.