Spiral flow-guide efficient heat exchange type sodium charging air valve

Abstract

The invention discloses a spiral flow-guide efficient heat exchange type sodium charging air valve which comprises an air valve head and an air valve rod. A cylindrical cavity is formed in the air valve rod in the axial direction of the air valve rod. The two axial end faces of the cavity are semi-spherical faces, and sodium is charged in the cavity. The surface of the air valve rod is provided with a chromium coating. A ring groove is formed in the air valve head in the circumferential direction of the air valve head. An overlaying layer is arranged in the ring groove in a covering manner, and the surface of the overlaying layer is a conical surface. According to the spiral flow-guide efficient heat exchange type sodium charging air valve, heat accumulated on the neck of the air valve and the center of the end face of the air valve head can be conducted away well, and therefore the air valve is uniform in heat radiation.

Description

technical field [0001] The invention relates to the field of engine parts, in particular to a spiral guide high-efficiency heat-exchange sodium flushing valve. Background technique [0002] In the past, the gasoline engine exhaust valve was made of solid exhaust valve, the head of the exhaust valve was made of high temperature resistant austenite material, the rod was made of martensite material, and then processed by welding, surface treatment and other processes. Exhaust valves of this structure and process can only be used on naturally aspirated gasoline engines whose exhaust temperature does not exceed 750°C. In a supercharged engine, due to the use of compressed air intake technology (specifically turbocharging, supercharging and dual supercharging), the combustion explosion pressure in the cylinder is higher than that of natural suction, and the temperature in the cylinder is also higher than that of natural gas. When the intake is high, the temperature of the exhaust...

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Problems solved by technology

In order to solve this problem, people drill a hole in the valve stem of the exhaust valve to form a cavity. The melting point of metal sodium is 97.81°C. Under the premise of a reasonable hollow cavity volume, when the valve is working, the temperature rises rapidly. Metal sodium changes from solid to liquid at high temperature, and moves up and down in the hollow cavity to continuously scour the valve face and valve stem, effectively transfer the heat load at the end of the valve face to the valve stem, and then cool the exhaust valve through the water passage in the cylinder head , which improves the heat dissipation of the exhaust valve and effectively reduces the heat load on the valve surface. In addition, the specific gravity of metal sodium is small, the overall mass of the valve becomes smaller, and the stiffness of the valve becomes stronger. Under the same conditions, the deformation of the valve is less Small; however, there is a problem with the existing hollow sodium-filled exhaust valve: the heat at the center of the valve neck and the end face of the valve head is not easy to be smoothly conducted away, and it is the place where the temperature gathers, which will affect the heat dissipation uniformity of the exhaust valve , reducing exhaust valve life

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