First, the reason why the dimensional accuracy of the turning parts for the clamping ring can not meet the requirements and its solution.
1. CNC machining due to the operator's carelessness, mistakes in measuring children's time, or wrong dial and improper use. Therefore, when measuring, it is very important to be careful and use the dial correctly. As far as the dial of the middle carriage handle is concerned, the dials of various types of lathes are different, and each small dial can be calculated by the following formula; Turning tool movement interval from scale to one grid = carriage screw interval/total number of scoring grids of dial (mm) Knowing the scale value of each grid in the future, we should pay attention to the fact that there is a gap between the lead screw and the nut, and sometimes the turning tool will move despite the rolling of the dial, and the turning tool will not move until the gap is turned. Therefore, in application, if the scale turns over the number of grids, it is never allowed to reverse only a few grids, but to reverse once and then align with the scale from the beginning.
2. The measuring tool itself has errors or is not aligned when it is used. Before using the measuring tool, it must be carefully checked and adjusted, and it should be aligned when using it.
3. Because of the change of temperature, the size of turning parts for the clamping ring changes. the chips are deformed, and the molecules of the chips move with each other, while they collide and generate a lot of heat when moving. In addition, because the chips collide with the front of the turning tool, and the rear of the turning tool collides with the surface of the workpiece, it also generates heat, which directly affects the tool and workpiece. Of course, the highest heat is chips (about 75%), followed by turning tools (about 20%) and workpieces (about 4%, and 1% in the air). When the workpiece is heated, its diameter increases (about 0.01 ~ 0.05 mm, the change of cast iron is larger than that of steel), and after cooling, its diameter shortens, forming waste products. Therefore, it is impossible to measure when the workpiece temperature is very high. If lateral measurement is necessary, pour enough cutting fluid during turning so as not to increase the temperature of the workpiece; Secondly, it is separated by rough and fine cars.
4. All the blanks will not work There are some factors, such as the blank itself is not straightened, and the base hole is biased.
Second, the main factors that the surface roughness of the turning parts for the clamping ring can not meet the requirements
1. lack of rigidity of lathe For example, the sliding block iron is loose and the transmission is unbalanced, which leads to oscillation. Of course, unstable lathe device will also lead to oscillation, which will cause the roughness of workpiece surface to decrease.
2. The lack of rigidity of turning tool leads to oscillation Therefore, as far as possible, choose a thick cutter bar and reduce the extension length of the turning tool; The lack of rigidity of the workpiece will also lead to oscillation, so the base frame should be used when turning the slender shaft, or one clamp and one top should be used instead of two center clamps.
3. Some parameters of turning tool cutting are incorrect According to the machinability characteristics of workpiece data, select a reasonable and suitable cutting viewpoint to reduce the surface roughness.
4. Because of the outbreak of chip accumulation tumor, the roughness of the workpiece surface decreases and the chip accumulation tumor is very strong When cutting, because of the participation of chip accumulation tumor, the appearance of workpiece presents the scene of galling or cutting grooves, which should be prevented as far as possible when turning. According to the analysis of the above factors, it is necessary to know early and prevent early in processing, eliminate the doubt in the bud, improve the accuracy of the workpiece and satisfy the planning request.