Double box opening model of auxiliary valve body of ball valve and casting process

Abstract

The invention provides a double box opening model of an auxiliary valve body of a ball valve. The double box opening model comprises an upper box, a lower box and a top core, the upper box and the lower box are divided from the inner side of a side flange of the auxiliary valve body, the upper box is subject to mold splitting from the inner side of an end flange, a top riser is arranged on the upper end face of the end flange, a chiller is allocated, and a side riser is arranged on the outer side of the side flange; a bottom mold filling pouring scheme is adopted; the top riser of the end flange and a solidification temperature field of the chiller are designed to be in axial symmetry, the top riser, the chiller and the upper end face of the end flange are jointly formed through the top core on the model, and the top core can move in a 360-degree manner in the axial direction; the side riser of the side flange is designed to be in a sinking and thermal center connection manner, and a bright casting and riser boundary is formed; and meanwhile, the uniform and in-order solidification temperature field is formed, coarse grain and solidification front secondary oxidation caused by local overheating of castings are avoided, and the reliability of the internal quality of the castings is guaranteed.

Description

technical field [0001] The invention relates to the technical field of casting molds for auxiliary valve bodies of ball valves, in particular to a two-open box model and casting process for auxiliary valve bodies of ball valves. Background technique [0002] As a type of valve developed in the 1950s, the ball valve is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. It only needs to be rotated 90° and can be closed tightly with a small rotational torque. Convenience, good performance, the usage is increasing year by year. [0003] like figure 1 As shown, one end of the auxiliary valve body 100 of the ball valve is the end flange 1 connected to the pipeline, and the other end is the side flange 2 connected to the main and auxiliary valve bodies; the inner cavity of the auxiliary valve body 100 is fully processed, and the precision and internal quality requirements are high. The casting process must ensure that the dimensions of...

AI Technical Summary

Problems solved by technology

[0004] For the secondary valve body 100 of a larger-diameter ball valve, there are two box-opening schemes in the traditional casting process as follows. One is a two-box scheme with live materials and horizontal splitting along the flange surface, such as figure 2 As shown, it includes the upper box 101, the lower box 102 and the live material 103, the upper box 101 and the lower box 102 are separated from the inner side of the side flange 2; another two-box scheme that passes through the center line of rotation horizontally, such as image 3 As shown, the upper box 101 and the lower box 102 are included, and the upper box 101 and the lower box 102 are divided into boxes horizontally from the center line of rotation; these two schemes have outstanding shortcomings. In the first scheme, a flange is made into a small A block of live material 103 is not conducive to ensuring the size; in the second scheme, although there is no live material 103, it is not conducive to the control of pouring quality, and the molten steel is easy to form turbulent flow during the pouring process, which is not conducive to the internal quality of the casting

There are also improved schemes for the first scheme, such as Figure 4 As shown, the loose material 103 is changed to the lost foam 104. The lost foam 104 can be used as a whole without cutting into small pieces of the loose material 103, which solves the problem of dimensional stability. However, every time a casting is produced, the lost foam must be made once. 104. Additional input is added, which is not conducive to improving production efficiency and saving resources

In addition, due to the unreasonable design of the casting gating system and the temperature field during the solidification process of the casting, shrinkage porosity and secondary oxidation inclusion defects are prone to appear in key parts such as the upper and lower flanges of the casting, which leads to a large amount of repairing of the casting and affects the service life of the casting

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