In the process of CNC machining, the
deformation of the workpiece is very common. If the precision is not enough, it
can be used for secondary processing. However, the deformation of the workpiece
has to be rebuilt. The deformation of the workpiece is a difficult problem. The
best solution is to eliminate the deformation of the CNC machining parts from
the root. Let's take a look at how the deformation of CNC machined parts is
caused.
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| cnc machining |
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.
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| cnc turning |
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.
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| cnc machining parts |
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.
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| cnc machining |
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.
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| cnc milling |
The above is a summary of the causes of the
deformation of CNC machined parts. They are some of the more critical points.
To ensure the quality of CNC machined parts, it is necessary to pay attention
to these points in order to process CNC machined parts.
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