When turning end faces and steps on the machine tool, an offset tool with a leading angle of 900 or an elbow turning tool with a leading angle of 450 is usually used, and the installation method is the same as that of the cylindrical turning tool.
(1) Cutting of the end face The cutting of the end face generally refers to the cutting of the end face with a large diameter and a short length.
When installing the end face machine tool, it should be emphasized that the tool tip should be strictly aligned with the center of the workpiece. If it is too high, the tool tip will chip, and if it is too low, a boss will appear in the center of the workpiece end face.
Under normal circumstances, the right side cutter is often used to roughen the end face. The machine tool has the following cutting forms according to the feed direction and tool installation angle.
The eccentric tool feeds the cutting end face from the outer circle of the workpiece to the center, and the turning tool of the machine tool is cut by the secondary cutting edge. Since the force direction F of the secondary cutting edge is inclined inward, the cutting force causes the turning tool to gradually penetrate into the workpiece. Tendency to be concave.
In order to improve the cutting conditions, it can be changed to feed outward from the center of the workpiece and cut with the main cutting edge. However, due to the small main declination angle of the machine tool, a small amount of back-engagement should be used.
The rake angle and chip flute are ground on the secondary cutting edge, the secondary cutting edge is used for cutting, and the turning tool is fed from the outer circle of the workpiece to the center, so that the cutting is stable and the chip removal effect is better.
When finishing the end face, the machine tool cutting form can also be used. As long as the arc-shaped transition edge is ground at the tip of the turning tool, the roughness value of the end face can meet the technical requirements.
When the cutting surface requires a higher end face, the high-speed steel fine turning can be used to offset the right tool. The machine tool, that is, the main cutting edge should ensure that the length is (2-3), which is parallel to the end face of the trimming /, and the front and rear ends have arc-shaped transition edges in the shape of broken lines. The feed direction can be from inside to outside or from outside to inside. When cutting the end face with high quality requirements, if the machining allowance and cutting amount are properly selected, this form of finishing turning is used to turn the end face with a right-biased tool, and the surface roughness value is set. Up to 0 8 pLm or more.
(2) Cutting of steps In the process of cutting steps, not only the outer circle should be turned, but also the end face of the step should be turned by the machine tool, and the length of the step should be ensured to ensure the perpendicularity between the end face of the step and the axis of the workpiece.
90 can be used when cutting low white levels with similar diameters between adjacent two. The offset tool is turned out directly; when cutting two adjacent high steps with a large difference in diameter, the outer circle turning tool with a larger main declination angle can be used for rough turning, and then 90 is used. Clear the roots with a partial knife, and turn the steps into a right angle.
Since the function of the step is to determine the axial position of the assembled parts, it is required that the end face of the step should be perpendicular to the axis of the workpiece. Therefore, when sharpening the eccentric tool, the main cutting edge should have a high straightness. When installing the machine tool turning tool , the main cutting edge should also have 2 with the workpiece end face. ~3. When the inclination angle reaches the length dimension, stop the longitudinal feed, shake the handle of the middle skateboard by hand, and exit slowly and evenly.