In the valve body machining of various wedge gate valves, there is usually a problem of processing M85×2-6H threads on a wedge surface with a wedge angle of 2° 5′.
Valve body structure shown in Figure 1. In order to improve ergonomics, a turning tooling that completes the machining of the threads on two inclined wedge surfaces at a time has been specially manufactured, as shown in FIG. 2 .
1. Tooling design
(1) Workpiece analysis As can be seen from Figure 1, this type of workpiece has symmetry. If the workpiece is rotated 180° around the O1′O2′ axis with an offset of e and parallel to the axis, the center O2 of the right-end thread is threaded at the original left end. The extension line of the center line O1O, and the right end of the thread surface is perpendicular to the original left end thread centerline O1O, that is, parallel to the original left end thread surface.
(2) Design requirements From the analysis of the workpiece, it can be seen that the machining of the threads on the two symmetrical wedge surfaces is completed at the same time. When machining the left-hand thread, the left-end thread center O1 must be on the center line of the lathe spindle, and the thread end surface is perpendicular to the centerline of the spindle. When machining the right thread, the workpiece must be rotated 180° on the fixture. After rotation, the center O2 of the right thread must also be on the center line of the lathe spindle, and the thread end surface is perpendicular to the centerline of the spindle.
1. Fetal styling 2. Positioning sleeve 3. Carcass 4. Washer 5. Nut M16 6. T-slot bolt 7. Positioning block
8. Allen screw M10×40 9. Allen screw 16×30 10. Swivel block 11. Bolt
12. Nut M27 13. Countersunk head screw 14. Handle 15. Positioning pin 16. Cap 17. Spring Figure 2
(3) Structural features There is a T-shaped groove on the carcass 1 that is easy to rotate. The centerline of each turning dimension at the left end of the carcass is the same as the centerline of the spindle of the machine tool, so that different conversion flanges can be used to connect with different lathe spindles; The intersection of the center line and the right end face of each carousel at the right end of the carcass shall be shifted upwards by h, so that the intersection point O between the center line and the center line of the lathe spindle is on the centerline of the left end thread, and the inclination of the right carcass bevel must be 2°52 '.
In order to rotate the workpiece before and after the rotation, the centers of the left and right threads are on the center line of the lathe spindle. The centerline of each rotation dimension of the right end of the slab 3 should be downwardly offset by e relative to the centerline of each rotation dimension on the left end.
(4) Calculation of key dimensions The center deviation of the rotation dimensions of the left and right ends of the slab 3, that is, the offset of the rotation of the workpiece around O1'O2' is e = 85/(2tg2 52').
The center height difference between the left and right ends of the carcass 1 is h=ltg2°52′.
2. Fixture clamping and application
The fixture is directly connected to the lathe with a conversion flange. The conversion flange connected to CW6163 is shown in Figure 3. Using the flange hole on the workpiece, press the workpiece with the nut 12 on the fixture, loosen the nut 5, and turn the fixture to align the scale on the carcass 3 with the scale on the carcass 1, and the positioning pin 15 enters the positioning After the sleeve 2, tighten the nut 5. When the upper end of the workpiece coincides with the upper end of the fixture, the thread on the inclined surface of the left end of the car, if not, the right end of the car is threaded. After processing one end, stop, loosen the nut 5, turn the workpiece 180°, align the scale line on the tire plate 3 with the scale line on the carcass 1 and the positioning pin 15 into the other end positioning sleeve, and tighten the nut 5 Turn the other thread.
image 3
The fixture is simple in structure and only needs to be replaced with different treads. It can be used to process similar valves of different sizes. The production practice has proved that the turning tooling is easy to use, and the machining of the threads on the two inclined wedge surfaces can be completed in a single clamping operation, and the processing quality of the product can be completely guaranteed.