Gearbox rear shell casting method

Abstract

The invention discloses a gearbox rear shell casting method. The method includes the steps that modeling material selection is conducted; parting face selection is conducted; casting position determining is conducted; one box is adopted for containing one part; the casting shrinkage rate is set; the pattern draft is set; a sand core is designed, wherein a positioning core head is arranged on the sand core, resin self-hardening sand is adopted for manufacturing the sand, and an exhaust channel is formed in the sand core; a casting manner is selected, wherein a sealed intermediate injection typecasting system is adopted, a semispherical sprue base is arranged, and a funnel-shaped sprue cup provided with a foam type ceramic filter net is arranged; a chilling block is arranged; the sizes of inner frames of an upper box and a lower box are the same; smelting is conducted; casting forming is conducted; and heat treatment is conducted. By means of the gearbox rear shell casting method, sequential solidification is achieved at the defect position of a casting, a compact structure is formed, in addition, grains at the position are refined, and the mechanical performance of the casting canbe improved; and during casting, large impurities can be intercepted on the outer surface of a filter, micro impurities are adsorbed on the wall face of a channel, a metal liquid flowing manner is changed into a laminar flow manner from a turbulent flow manner, and the probability that filtered metal is further oxidized is lowered.

Description

technical field [0001] The invention relates to a casting method for a gearbox rear casing, which belongs to the technical field of gearbox rear casing casting. Background technique [0002] The rear casing of the gearbox is the rear casing of a light truck gearbox. The gearbox is a commonly used transmission device in mechanical equipment and is widely used in automobiles. The light truck gearbox is an important part of the rotating parts of the car. The rear case of the gearbox is mainly used to support and protect the gear transmission mechanism, and at the same time, it can seal the lubricating oil in the gearbox. The quality of the gearbox housing directly affects the overall performance of the gearbox, so it is of great significance to control its quality and precision. The rear casing of the gearbox is mainly used in the gearbox of a light truck. Its outline size is 275mm×176mm×160mm, the wall thickness is about 5-28mm, the main wall thickness is 5mm, and the mass is...

AI Technical Summary

Problems solved by technology

The existing gearbox rear casing castings have low casting efficiency, low dimensional accuracy, and are prone to defects such as shrinkage cavities, shrinkage porosity, cracks, and penetration. The quality of the produced castings is difficult to guarantee and cannot meet the performance requirements of the castings.

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