Machining method of slender shaft of small precision parts machining:
Due to the poor rigidity of the slender shaft, it is extremely easy to deform during processing, which greatly affects the processing accuracy and processing quality. For this reason, the following measures are often used to solve the problem in production.
(1) Improve the clamping method of the workpiece
During rough machining, due to the large cutting margin, the workpiece is subjected to a large cutting force. Generally, the clamping method is adopted, and the tip of the tailstock adopts an elastic tip to allow the workpiece to extend freely in the axial direction. However, due to the limitation of the tip elasticity, the axial extension is also limited, so the tightening force is not very large. In high-speed, large-volume cutting, there is a danger of the workpiece from falling off the tip. Carafa can be used to avoid this phenomenon.
When finishing turning, the double tip method (the tailstock should use elastic tip at this time) is helpful to improve the accuracy. The key is to improve the accuracy of the center hole.
(2) Adopt a knife holder
The follower is an extremely important accessory for turning slender shafts. The use of the tool rest can offset the influence of the radial cutting component during machining, thereby reducing cutting vibration and workpiece deformation, but careful adjustment must be paid to keep the center of the tool rest consistent with the center of the machine tool tip.
(3) Adopt reverse feed
When turning a slender shaft, the turning tool is often made to feed in the direction of the tailstock (the cara tool should be installed at this time), so that the direction of the feed force exerted by the tool on the workpiece is toward the tailstock, thus causing the workpiece to produce axial elongation The Kara tool greatly reduces the bending deformation caused by the elongation of the workpiece.
(4) Using turning tools for turning slender shafts
Turning tools for turning slender shafts generally have large rake angles and entering angles to make cutting brisk and reduce radial vibration and bending deformation. The turning tool for rough machining has chip breakers on the rake face to make chip breaking easy. The precision turning tool often has a certain negative edge inclination, so that the chips flow to the surface to be machined.
