Pouring system used for low pressure casting of 64-slice spiral computed tomography (CT) machine stators

Abstract

The invention relates to a pouring system used for low pressure casting of 64-slice spiral computed tomography (CT) machine stators. The pouring system of a casting mold comprises a straight runner, a horizontal runner and inner gates, and is innovatively characterized in that the inner gates are arranged in positions in a mold cavity of the casting mold, which are corresponding to the bottom of a product inner ring and close to connecting ribs; the inner gates are similarly arranged in positions in the mold cavity, which are corresponding to the bottom of a product outer ring and close to the connecting ribs; the inner gates are respectively communicated with a liquid lifting pipe of low pressure casting equipment through the straight and the horizontal runners; wedge-shaped structures are adopted by the inner gates; and an exhaust cooling needle is arranged at the top of the casting mold. The inner gates of the pouring system are arranged in the positions of the inner and the outer rings, which are close to the connecting ribs, so a good mold filling effect is achieved; the wedge-shaped structures are adopted by the inner gates, so the temperature of a sand mold at the upper side wall parts of the inner gates can be improved, hot spots are easy to eliminate, and consecutive solidification is smoothly realized; a fireproof material layer is spread on the surface of the mold cavity of the casting mold, so aluminum liquid cannot enter the sand mold to produce gas at high temperature during long time pressurization and pressure maintaining and thereby shrinkage porosity is avoided.

Description

technical field [0001] The invention relates to a gating system, in particular to a gating system for low-pressure casting of a 64-row spiral CT machine stator. Background technique [0002] The level of medical equipment in my country's medical institutions is still very low. About 15% of the medical instruments and equipment owned by 175,000 medical and health machines nationwide are products around the 1970s, and 60% are products in the mid-1980s. Large-scale diagnosis and treatment Equipment such as X-ray machines, CT scans, nuclear magnetic resonance, deep X-ray therapy, cobalt 60 therapy machines, gamma knife, etc. are urgently needed equipment and updated equipment in third-class and second-class A hospitals. However, these high-end, high-quality, and cutting-edge equipment are mainly imported from the United States, Europe, and Japan. These equipment range from hundreds of thousands to tens of millions. If high-end medical equipment is localized, its price will be 1 / ...

AI Technical Summary

Problems solved by technology

There are certain defects in this process: a. A gating system with a large-caliber riser is adopted. The gate is designed on the side of the mold away from the connecting ribs, and several risers are set on the side with the connecting ribs for exhaust and replenishment. shrinkage, the yield rate of molten metal process is low, and there are many machining processes; b. The setting of the riser makes it only use low pressure to fill the mold, and cannot adopt the process of supercharged crystallization, which is not a real low-pressure casting, and the shrinkage effect Slightly worse, the compactness of the casting structure has a certain influence; c. The gating system uses the riser structure in the traditional gravity pouring as the gate, and the gate is flat, the hot spot is not easy to eliminate, and there are shrinkage porosity and holes

Therefore, when this process is used to produce the stator of the 64-row spiral CT frame, very high requirements are put forward for the process and equipment. When the above-mentioned low-pressure filling process is used to produce this product in China, the qualified rate of castings is very low.

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