Hollow mandrel whole sand core casting mold for super long hollow camshaft

Abstract

The present invention proposes a hollow mandrel integral sand core casting mold for an ultra-long hollow camshaft, which includes an upper mold, a lower mold, and a resin sand integral sand core. There are multiple core supports set at certain intervals along the length direction. The core supports protrude 3-5 support arms along the circumferential direction. There is a cold iron. When pouring with the present invention, the resin sand integrated sand core is supported by the core support to ensure strength and rigidity, and will not loosen and break. Further, the core support on the resin sand integral sand core is melted and integrated with the hollow mandrel, thereby ensuring Casting of hollow mandrel; the integral sand core of resin sand is provided with a central vent hole to facilitate the venting of the cavity. The invention changes the positioning mode of the integral sand core in the lower mold cavity, thereby realizing the hollow mandrel casting of the super-long hollow camshaft, and controlling the reject rate within 3%.

Description

technical field [0001] The invention relates to the technical field of engine camshaft manufacturing, in particular to an integral sand core casting mold for an ultra-long hollow camshaft. Background technique [0002] The camshaft is one of the five core parts of the automobile engine. The traditional manufacturing method of the camshaft of the automobile engine mainly adopts the integral casting or integral forging of the camshaft blank, and then cuts it for production. Cast camshafts mainly include chilled cast iron, chilled nodular cast iron, etc., which are the main production forms of automotive camshafts at present. [0003] In the prior art, the mainstream manufacturers of gasoline engines mainly use cast camshafts, which are generally solid type due to technical reasons. The performance of the camshaft is mainly guaranteed by the material of the cam working surface. As long as the connecting shaft has a certain bending strength, it can meet the requirements without...

AI Technical Summary

Problems solved by technology

However, it is difficult to cast an ultra-long hollow combined camshaft with a length of more than 60 cm, mainly because in the process of casting the hollow mandrel, the casting mold needs to use a resin sand integral sand core, and in the casting cavity, it is only supported from both ends Resin sand integral sand core, but the length of the resin sand integral sand core is too long, the strength and stiffness are low, resulting in looseness and fracture, the hollow mandrel forms sand inclusion defects, and the reject rate remains high, with a reject rate of 20-30%

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