A gating system for steel castings on crowns of thin-wall conical water turbines

Abstract

The invention relates to a pouring system of an upper crown steel casting piece of a thin-wall conical water turbine. The system comprises a sprue cup, a sprue in a vertical direction, and a slow flow cross gate in a horizontal direction, wherein two branches of first-grade shunt gates are symmetrically arranged at the tail end of the slow flow cross gate along the two sides of a molding cavity; two branches of second-grade shunt gates are symmetrically arranged at the tail end of each first-grade shunt gate along the periphery of the bottom side of the molding cavity; the tail ends of the second-grade shunt gates are respectively connected with cross gates; the cross gates comprise a cross gate 1 horizontally arranged at the bottom of the molding cavity in the radial direction, and a cross gate 2 vertically connected with the outer end of the cross gate 1; the inner end, near the radial direction, of the cross gate 1 is vertically connected with elliptic ingates; all the elliptic ingates are connected to form an integrated annular ingate; the integrated annular ingate is communicated with the bottom of a molding cavity of the steel casting piece; circular ingates are vertically connected to the cross gates near the two ends; and the circular ingates vertically upwards extend to the lower side of the thickest place of the middle part of the molding cavity of the casting, and are communicated with the molding cavity.

Description

technical field [0001] The invention relates to the field of casting technology, in particular to a pouring system for a steel crown casting of a thin-wall conical water turbine. Background technique [0002] The crown castings of turbine runners manufactured by our company for a hydropower manufacturer, such as figure 1 As shown, the single weight is 15300kg, the maximum diameter of the top is 3440mm, the minimum diameter of the bottom is 500mm, the height is 1800mm, and the minimum wall thickness of the bottom is 30mm. All areas of castings meet the requirements of UT2 level, and the quality requirements are very high, especially the flow surface area needs to be welded with blades, and defects such as slag inclusions and pores are not allowed. Therefore, the gating system must ensure that there is no sand washing during the pouring and filling process, which can minimize the problems of molten steel backflow, turbulent flow, entrained air, etc., and can reduce the slag i...

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to provide a pouring system for steel castings on the upper crown of thin-walled conical water turbines to solve the problems of sand washing, backflow and air entrainment in the pouring and filling process of such steel castings, thereby improving Quality and pass rate of steel castings

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