Apr 25, 2020
1. What are the causes of deformation and vibration when the pin is slender? What solutions can be taken?
Answer: When the slender shaft is pinned, the causes of deformation and vibration are:
(1) The workpiece is deformed by cutting thermal elongation.
(2) The workpiece bends and vibrates under the action of cutting force.
(3) Vibration caused by the weight deformation of the workpiece.
(4) The work piece is exacerbated by the centrifugal force to increase bending and vibration.
The measures taken are:
(1) Use the center frame
(2) Use the follower frame
(3) Reduce the
(4) thermal deformation;
Reasonably choose the geometry and cutting amount of turning tools.
2. The reason why the "slubby shape" is generated when the slender shaft of the follow tool post is used is that the contact pressure of the support finger of the follow tool post and the workpiece is too large,
The correct way to use the heel holder is:
(1) The distance between the support position of the support claw on the processed surface and the tool is within 10MM.
(2) Control the amount of back-eating knives, and cut the remaining amount of the blank over the entire shaft length, without leaving black scars and spots.
(3) Adjust the supporting claws to lightly touch the outer circle in the order of rear, top and bottom, feel, ear, and visually check, so that each claw maintains the same small gap and can move freely.
(4) Keep track of the contact condition of each support claw at all times and ensure good lubrication.
3. What are the factors that affect the processing quality of thin-walled workpieces?
(1) The clamping force deforms the workpiece, which affects the dimensional accuracy and shape accuracy.
(2) The cutting heat causes deformation of the workpiece and affects the dimensional accuracy.
(3) The cutting force causes the workpiece to vibrate and deform, affecting the dimensional accuracy, shape accuracy and surface roughness of the workpiece.
(4) The residual internal stress deforms the workpiece and affects the dimensional accuracy and shape accuracy.
4. What are the methods to prevent and reduce the deformation of thin-walled workpieces?
(1) When processing, it is divided into rough, fine turning, clamping when rough turning, loosening when finishing.
(2) Reasonably select the geometric parameters of the tool and increase the rigidity of the tool handle.
(3) Use slotted sleeves or special soft jaws to increase the clamping contact area.
(4) Apply axial clamping methods and clamps.
(5) Add convex edges and process aids to improve the rigidity of the workpiece itself.