Ball valve core hydraulic expansion method

Abstract

The invention discloses a hydro-bulging method of a valve core of a ball valve, which is that at first a mould is prepared according to the shape of the ball valve, then the hydro-bulging method is used for forming an external ball shell with a groove at the middle part of a metal pipe after the metal pipe is cut to the needed length; the metal pipe is cut to the matched length of the external ball shell to form an internal straight pipe; and then the internal straight pipe is put into the external ball shell and the welding seam that connects both ends is welded; and a valve core green body is obtained; at last a product can be obtained after doing the corresponding machine processing, polishing and deburring on the surface of the valve core of the valve core green body. The valve core of the ball valve produced by the hydro-bulging method which is compact in structure avoids defects of the casting craft from the root and has important significance on material conservation, product quality improvement, energy conservation and environment protection.

Description

technical field [0001] The invention belongs to the field of advanced manufacturing technology, and in particular relates to a hydraulic bulging method for a ball valve core. The method adopts an internal high-pressure forming technology to deform and stick a pipe material in a mold, and finally realize the forming of the ball valve core. Background technique [0002] Ball valves are widely used in petrochemical, construction, pneumatic and hydraulic industries. Due to the blockade of foreign technology, domestic enterprises producing ball valves still generally use the casting process that has been eliminated abroad to produce valve cores. The working conditions of the spool casting process are poor, which is harmful to the environment and workers. Although the casting process of the valve core is simple and the price is cheap, there are defects such as casting pores, sand inclusions and impurities, poor dimensional accuracy, and high scrap rate, resulting in cracks and mi...

AI Technical Summary

Problems solved by technology

Although the casting process of the valve core is simple and the price is cheap, there are defects such as casting pores, sand inclusions and impurities, poor dimensional accuracy, and high scrap rate, resulting in cracks and micropores on the outer wall of the valve core, resulting in low productivity and material utilization of the valve core. Low

At the same time, the sand casting precision is low and the mud core is biased, resulting in serious uneven wall thickness of the casting valve core, large machining allowance, and high material consumption.

In particular, the pressure resistance of the cast spool is poor, resulting in a low service life and poor reliability during the use of the ball valve.

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