Design and calculation method of flange wedge valve body turning tool

In the valve body processing of various types of wedge gate valves, there is usually the problem of processing M85×2-6H threads on the inclined wedge surface with a wedge angle of 2°5′. ​

In order to improve work efficiency, a turning tool is specially designed to complete the thread processing on the two inclined wedge surfaces in one clamping, as shown in Figure 2.
1. Workwear design
(1)Artifact analysis

This type of workpiece is symmetrical. If the workpiece is rotated 180° around the O1′O2′ axis with an offset of e and parallel to the axis, then the center O2 of the right end thread is on the extension of the center line O1O of the original left end thread, and the right end The thread end face is perpendicular to the center line O1O of the original left end thread, that is, parallel to the original left end thread end face.
(2)Design requirements

From the workpiece analysis, it can be seen that to complete the processing of threads on two symmetrical inclined wedge surfaces in one clamping, when turning the left end thread, the left end thread center O1 must be on the lathe spindle center line, and the thread end face is perpendicular to the spindle center line; when processing the right end thread , the workpiece must be rotated 180° on the fixture. After rotation, the right end thread center O2 must also be on the center line of the lathe spindle, and the thread end face is perpendicular to the spindle center line.

(3) Structural features

There is a T-shaped groove on the carcass 1 to facilitate rotation. The center line of each rotation dimension at the left end of the carcass is consistent with the center line of the machine tool spindle. In this way, different conversion flanges can be used to connect with different lathe spindles; while the right end of the carcass each rotates The intersection point of the center line of the size and the right end face should be moved upward by h so that the intersection point O of the center line and the center line of the lathe spindle is on the center line of the left end thread. The inclination angle of the right end slope of the carcass must be 2°52′. ​

In order to ensure that the centers of the threads at the left and right ends of the workpiece are on the center line of the lathe spindle before and after the workpiece is rotated, the center line of each rotation dimension at the right end of the tire plate 3 should be offset downward by e relative to the center line of each rotation dimension at the left end.
(4) Calculation of critical dimensions

The center deviation of the rotational size of the left and right ends of the tire plate 3 is the offset of the workpiece rotating around O1′O2′ e=85/(2tg2°52′). ​

The center height difference of the rotational dimensions between the left and right ends of the carcass 1 is h=ltg2°52′.
2. Clamping and application of fixtures

The clamp is directly connected to the lathe using a conversion flange, and is connected to the conversion flange of CW6163. Use the flange hole on the workpiece to press the workpiece on the fixture with nut 12, loosen nut 5, and rotate the fixture to align the scale line on tire plate 3 with the scale line on carcass 1, and positioning pin 15 into position. After setting 2, tighten nut 5. When the upper end of the workpiece is consistent with the upper end of the fixture, the thread on the left end of the wedge is machined. If they are not consistent, the thread on the right end is machined. After processing one end, stop the machine, loosen the nut 5, turn the workpiece 180°, align the scale line on the tire plate 3 with the scale line on the carcass piece 1, enter the positioning pin 15 into the positioning sleeve at the other end, and tighten the nut 5. The other end thread can be turned. ​

The fixture has a simple structure and can be used to process similar valves of different sizes by simply replacing different tire plates. Production practice has proved that this turning tool is easy to use and can complete the processing of threads on two inclined wedge surfaces in one clamping, which can fully guarantee the processing quality of the product.