1, valve sphere forming method comparison

(1) casting which is a traditional processing method, it requires a complete set of smelting and casting equipment, also need larger plants and workers, large investment, multi process and complex production process, and the pollution of the environment, directly affect the technical level of the workers of each process sound product quality. The valve ball capillary leakage problems cannot be solved thoroughly, and rough machining allowance, high waste, often in the process because of casting defects make the scrap, to make the product cost increase, quality can not be guaranteed, the law should not be used in factory.

(2) forging method, which is one of the other methods adopted by many domestic valve manufacturers. It has two processing methods: one is to cut and forge spherical solid blanks with round steel, and then to do mechanical processing. The second is in the large-scale press molding feed into the next round of the stainless steel plate, are hollow hemispherical blank, and then welded into the valve ball blanks for machining, high material utilization of this method, but need a high-power press and the furnace and argon arc welding equipment, is expected to invest 3 million yuan to the formation of productivity, this method is not suitable for the plant.

(3) spinning metal spinning is an advanced, non chip processing methods, the new branch is pressure processing, which combines the technology characteristics of forging extrusion rolling and rolling, has high utilization rate of materials (up to 80-90%), save a lot of processing time (1-5 minutes forming). Strength of materials by post spinning can be doubled. The spinning, spinning wheel and workpiece contact area of small, metallic materials for the two or three to stress to the state, easy to deformation, the driving force in the smaller, the unit can get a higher contact stress (up to 25-35Mpa), therefore, light equipment weight, total power required for small (not to press 1/5-1/4), has been recognized as the foreign valve industry valve ball processing scheme of energy saving, but also applicable to other hollow rotary machining parts. Spinning technology has been widely used in foreign countries and the development of high-speed, process and equipment are very mature and stable, and realize the automatic control of machine, electricity, liquid integration. At present, spinning technology has also been greatly developed in China, and has entered the stage of popularization and application.

2, spinning valve ball blank technical conditions, according to the production needs of our factory and combined with spinning deformation characteristics, draw up the following technical conditions:

(1) material and type of spinning blank: 1Gr18Nr9Tr or 2Gr13 steel tube or steel plate;

(2) the shape and structure of the sphere of the spinning valve: