How are the causes of the deformation of CNC workpieces caused?
In the process of CNC machining,the deformation of the workpiece is very common.If the precision is not enough,the secondary processing can be carried out,but the deformation of the machined parts has to be rebuilt.The deformation of the machined parts is a difficult problem to be solved.The best solution is to prevent the deformation of the CNC machining parts from the root cause.Let's take a look at how the deformation of CNC workpieces is caused.
1.The influence of the material and structure of the workpiece on the deformation of the workpiece
The amount of deformation and the complexity of the shape,the long width and the wall thickness are proportional to the rigidity and stability of the material.It is generally necessary to reduce the influence of these factors on the deformation of the workpiece when designing the part.Especially in some large parts and structures,it is necessary to make the structure reasonable.In the process of machining,it is necessary to control the hardness and looseness of the blank to ensure the quality of the blank and reduce the deformation of the workpiece.
2.Deformation caused by workpiece clamping
When clamping the workpiece,you need to select the correct clamping point and select the appropriate clamping force at that position.Therefore,it is necessary to keep the clamping point and the supporting point in line,so that the clamping force acts on the support,the clamping point should be as close as possible to the working surface,and the position where the force is not easily caused by the clamping deformation is selected.
When there is a clamping force acting in several directions on the workpiece,the order of the clamping force is required.For the workpiece to be in contact with the support,the clamping force should be applied first,not too large,and the main clamping force for balancing the cutting force,Should be at the end.
Secondly,it is necessary to increase the contact area between the workpiece and the jig and the axial clamping force used.Allowing the rigidity of the part to be enhanced is very effective in solving the clamping deformation.However,due to the shape and structure of thin-walled parts,it will result in lower rigidity.In this way,deformation occurs due to the application of the clamping force.
3.Deformation caused by workpiece processing
During the cutting process,due to the cutting force,the workpiece will have an elastic deformation toward the direction of the force,which is the knife phenomenon.For similar deformations,corresponding measures can be taken on the tool.When finishing,the tool is required to be sharp,so that on the one hand,the resistance formed by the friction between the tool and the workpiece can be reduced.On the other hand,the heat dissipation can be improved when the tool is cut.Ability to reduce residual internal stress on the workpiece.
The heat generated by the friction between the tool and the workpiece during machining also deforms the workpiece,and high-speed machining is generally selected.In this type of processing,since the cutting chips are removed in a short time,most of the cutting heat is carried away by the chips,which can effectively reduce the deformation.
In order to ensure the accuracy of the parts,a reasonable amount of cutting is required during the machining process.In the case of thin-walled parts with high processing precision,symmetric machining is generally adopted to equalize the stress generated on the opposite sides to reach a stable state,and the workpiece is flat after processing.
The above is a summary of the causes of the deformation of CNC machining parts,are some of the more critical points,in order to ensure the quality of CNC machining parts,you need to pay attention to these points,in order to carry out the processing of CNC machining parts.