Shape follow-up soluble preform for internal combustion engine piston and piston manufacturing method

Abstract

The invention discloses a shape follow-up soluble preform for an internal combustion engine piston and a piston manufacturing method. The shape follow-up soluble preform comprises, by mass, 25%-50% ofNa2CO3, 1%-10% of mullite powder, 1%-10% of aluminum titanate powder, 1%-10% of aluminum oxide fibers and the balance NaCl. The preparation method comprises the following steps: 1) adding the NaCl and the Na2CO3 into a silicon carbide anti-corrosion crucible in proportion, heating until the NaCl and the Na2CO3 are molten, and controlling the temperature at 750-950 DEG C; 2) adding the ground mullite powder and aluminum titanate powder in proportion, and keeping the temperature for 10-30 minutes; 3) adding the aluminum oxide fibers, fully stirring before each time of pouring, and pouring intoa preheated soluble preform mold after stirring to obtain the shape-following soluble preform; and 4) casting the shape follow-up soluble preform with burrs removed into a piston, and then dissolvingthe preform with water to obtain the internal combustion engine piston with a shape follow-up inner cooling oil cavity. The temperature of a whole piston head mainly comprising a combustion chamber and a first annular groove can be effectively reduced, the production process of the soluble preform is simplified, and the production cost is reduced.

Description

technical field [0001] The invention relates to the technical field of internal combustion engine manufacturing, in particular to a conformal soluble preform for internal combustion engine pistons and a piston manufacturing method. Background technique [0002] As the country pays more and more attention to energy conservation and environmental protection, the requirements for internal combustion engine exhaust emission regulations are becoming more and more stringent. In order to improve the comprehensive utilization rate of internal combustion engines and reduce harmful emissions, the power per unit area of ​​internal combustion engines has been continuously increased, and the thermal and mechanical loads of pistons have also been continuously increased, especially pistons for diesel engines. The aluminum alloy piston is the core component of the internal combustion engine. Because it directly contacts high-temperature gas, it withstands high temperature and high pressure,...

AI Technical Summary

Problems solved by technology

However, limited by the molding process of the soluble core of the piston, the soluble core can only be made into a relatively simple shape, and because the soluble core is porous, it is only suitable for gravity casting. When a certain pressure is added during the casting process, the aluminum liquid is easy to enter In the soluble core, the inner cooling oil cavity is blocked

Moreover, the soluble core suitable for die casting has complicated process equipment, low yield, expensive raw materials, and high production cost, which is not conducive to large-scale industrial application.

[0004] Invention patent CN101869963B introduces a method of mixing halide salts, reinforcing agents, and binders after drying, pressing to form, then sintering, and finally turning to form. Due to the limitation of the pressing process, this method is only suitable for making soluble cores. simple shape

[0006] In addition, in the prior art, the soluble core of the internal cooling oil channel is formed by pressing, and the forming method is mostly one side is formed by a mold and the other side is processed, or both sides are processed surfaces

Due to the low strength of the soluble core blank, it is not suitable for complex lathe processing, and the pressing mold itself does not have the ability to produce products with complex shapes. This type of soluble core and its formed internal cooling oil passage cannot minimize the combustion chamber and the first ring groove temperature

Images