In mechanical machining, the adjustment of the workpiece is the first step. The purpose is to make the reference centerline of the workpiece coincide with the rotation center of the machine tool to ensure that the outer surface of the machined part is concentric with the reference surface. This process may seem simple. In fact, the method of calibration and the speed of calibration play a key role in the quality and efficiency of parts processing. This process can be easily accomplished for those parts with relatively regular shapes and calibration references. However, most parts are rough before processing, some are irregular, the reference is hard to find, and the adjustment is difficult. Large, especially large, irregular parts, the problem is more prominent. machining manufacturer
First, regular adjustment method
The external threading at the right end of the hook requires the centerline of the thread to coincide with the symmetrical center of the left hook section. As the workpiece is a blank forging, the shape is not only poor in flatness, but also the balance is very uneven, so the adjustment is very difficult. machining manufacturer
Before turning on the lathe, we usually use the method of scribing to find out the basis of the blank, that is, place the workpiece on the scribe table first, and on the premise of ensuring the machining allowance in each place, draw the waist line in both horizontal and vertical directions ( That is, two center planes perpendicular to each other) XX, YY, as a reference before turning. Then the workpiece on the lathe, one end by the front chuck grip the left end of the workpiece on the construction of the rider, the other end with a small four-jaw chuck clamped to the tailstock, the calibration reference plane XX is roughly flat, and in the XX to take office Take two points A, B (the farther the distance between two points is, the better), and use the scribing dial to measure whether the two points are equal. machining manufacturer
If not, you can level two points by adjusting the claws at both ends. Then move the scimitar dial to the opposite side of the work piece to check if the same waist line and the front face are equal in height. If not, turn the chuck and change the height of the stylus so that the front and rear waistlines are at the same height. At this time, only the plane where the XX is located is parallel to the horizontal center plane of the machine tool, and the workpiece is rotated through 180° again. Check whether the height of the original waist line and the scribing disk are the same. If they are not the same, adjust the height of the two ends to adjust the height. Repeatedly until the XX horizontal line coincides with the horizontal centerline of the machine tool. Then turn the workpiece 90° again so that the other belt Y-Y turns to the horizontal position. The same method is used to adjust the waist line to coincide with the horizontal center plane of the machine tool. At this time, the calibration process of the workpiece is completed. This method is time-consuming and laborious. machining manufacturer
Second, the improved school adjustment method
If you adopt another method, the situation will be greatly improved. The specific method is: before the workpiece on the lathe, first in the boring machine in accordance with the dash datum to process the small end of the center hole, and then on the lathe, using a folder and a top method of clamping, the workpiece is roughly flat (visual inspection), Then, by adjusting the heights of the claw and the scribing disk, any two points on the XX waistline away from the points M and N are brought to the same height, thus completing the adjustment in one direction.
Then turn the workpiece 90° again, use the same method to level the other waist line Y-Y, and then adjust it a little to complete the entire calibration process, without having to perform a 180° turn calibration. machining manufacturer