Machining method for valve rod

Abstract

The invention discloses a machining method, and particularly discloses a machining method for a valve rod. The machining method for the valve rod comprises the following steps: blanking a round steelblank of the valve rod at first; carrying out rough machining on a tail end head, a polished rod part, back seal, and a groove buffer area between the back seal and the polished rod part, of the valverod; carrying out rough turning on a thread rod; rolling a trapezoidal thread which is formed through the rough turning on a thread rolling machine by virtue of a die, and correcting the redundant parts and nonstandard parts of the trapezoidal thread through cold rolling; carrying out finish turning on the back seal, and a groove between the back seal and the polished rod part to form the groovebuffer area; and carrying out finish turning on a polished rod of the valve rod. The machining method for the valve rod has the following beneficial effects: less material waste, no burrs, edges and corners, and high smoothness and concentricity are achieved; the valve rod is flexibly and easily opened and closed while being cooperatively used with a valve; high sealing performance is achieved; the valve rod is highly light and not liable to be damaged and bent, and high in tensile resistance and wear resistance; and the service life of the valve is prolonged.

Description

technical field [0001] The invention relates to a processing method, in particular to a processing method of a valve stem. Background technique [0002] In the existing large valve stem processing technology, the threaded part is mainly formed by spiral flying knife or CNC machine tool processing technology, and the polished rod part is mainly processed by grinding machine, which has many thread burrs formed by spiral flying knife or numerical control processing technology, and its accuracy Low, the finish is not high, there is no chamfering buffer zone, when used in conjunction with the valve, the valve is not in place when the valve is opened and closed up and down, it is easy to damage the nut thread, and the sealing performance is poor. When the traditional pure rolling technology is used to process the valve stem, the valve stem The junction of the screw thread and the polished rod will be bent and deformed, the concentricity is different, the finish is not high, and de...

AI Technical Summary

Problems solved by technology

[0002] In the existing large valve stem processing technology, the threaded part is mainly formed by spiral flying knife or CNC machine tool processing technology, and the polished rod part is mainly processed by grinding machine, which has many thread burrs formed by spiral flying knife or numerical control processing technology, and its accuracy Low, the finish is not high, there is no chamfering buffer zone, when used in conjunction with the valve, the valve is not in place when the valve is opened and closed up and down, it is easy to damage the nut thread, and the sealing performance is poor. When the traditional pure rolling technology is used to process the valve stem, the valve stem The junction of the screw thread and the polished rod will be bent and deformed, the concentricity is different, the finish is not high, and defects such as bending and fracture often occur. The billet larger than the maximum diameter of the valve stem is machined, resulting in waste of materials