When the diameter of the two ends of the conical surface of the lathe has a strictly limited fit requirement, the limit sleeve gauge or the plug gauge can be used to control the diameter size. The commonly used methods of lathes are:
①Calculation method. The lathe places the limit sleeve gauge or the limit plug gauge in the measured cone or conical hole respectively, measures the distance a between the end face of the workpiece and the limit surface of the sleeve gauge or plug gauge, and then calculates the amount of the back knife by the calculation method.
② moving saddle method. After the lathe measures the distance a between the workpiece end face and the limit surface, the turning tool touches the diameter of the small end of the workpiece, and then shakes the small slide plate to make the turning tool obliquely away from the workpiece end by a vertical distance. . At this time, when the middle slide plate and the small slide plate are fixed, move the saddle so that the turning tool is in contact with the small end plane, and then the small slide plate is fed obliquely. Although the lathe does not have a moving slide plate at this time, the turning tool has realized the lateral infeed, and the amount of the back cut is exactly the diameter cutting allowance of the workpiece.
"i During semi-finishing, the amount of back-feeding knife should not be too large, and the taper angle should be adjusted as the main focus. Generally, the fine-turning allowance should be more than 0 lmm to prevent the workpiece from being scrapped.
When the fine turning has a conical surface that meets the requirements, a high-speed steel turning tool with a wiper edge should be used. Talk about low-speed training. Lathe and fill with suitable cutting fluid. For lathes such as cutting plastic materials, use cutting fluids such as cutting oil. It has a lubricating effect; when cutting gray cast iron, kerosene can be used to refine the cutting layer and improve the surface quality.
When the turning tool is fed obliquely, hold the handle of the small slide plate with both hands and shake it alternately with both hands. In this way, the lathe can make the manual feeding speed of the turning tool uniform and stable.
The characteristics of the small slide method
1) The angle adjustment range is large, and the conical surface with a large conical angle can be turned.
2) Wide range of applications, can turn cones and tapered holes.
3) Restricted by the working stroke of the small sliding plate, only the conical surface with the cone length less than the working stroke of the small sliding plate can be processed.
4) It can only be fed manually, which is labor-intensive.