The structural characteristics of sleeve parts are that the hole wall thickness is thin, and the thin-walled parts are easy to deform during the machining process, especially under the action of cutting force and thermal deformation. In order to prevent deformation, the following process measures are taken:
1.Separate roughing and finishing
By separating roughing and finishing, the effects of cutting forces and cutting heat can be reduced. Distortions produced during roughing can be corrected during finishing.
2.Reduced effect of clamping force
1) Radial clamping is used in precision CNC machining, and the clamping force should be evenly distributed, avoiding concentration on a certain radial section and reducing the clamping force per unit area of the workpiece. If it is possible to clamp the workpiece together with the ring with an open ring of a suitable thickness, special jaws can also be used to increase the contact area.
2) The position of the clamping force should be selected in the part with strong rigidity to improve the deformation of the thin-walled parts under the action of the clamping force.
3) Change the direction of the clamping force, from radial clamping to axial clamping.
4) Add a rigid process boss or process thread to the workpiece to reduce the clamping deformation, clamp with a special structure of the jaw, and finally cut off the flange at the end of machining.
3.Reducing the effect of cutting forces on deformation
1) Increase the rake angle and main rake angle of the tool to make the cutting edge sharper and reduce the radial cutting force.
2) Separate roughing and finishing, and use a smaller amount of stock removal to reduce distortion.
3) The inner and outer circular surfaces are processed at the same time to counteract the effect of cutting force.
4.Heat treatment arrangement
The heat treatment arrangement between roughing and finishing reduces the effects of heat treatment deformation. Sleeve parts usually produce large deformation after heat treatment, and the deformation can be corrected during finishing, but the finishing allowance should be increased appropriately.
