Automobile engine parts Analyze the role of valves and valve springs

Everyone knows that the engine generates power by sucking in air and fuel mixed and entering the engine cylinder to burn and explode, and then discharge the burned exhaust gas. The mechanism that controls the intake and exhaust of a four-stroke engine is the valve.

Valve is one of the most important parts inside the engine. The valve is divided into intake valve and exhaust valve. Its appearance is similar to the shape of a horn. The intake valve is responsible for the control of air entering the intake manifold and fuel mixing (in-cylinder direct injection is to supply fuel in the cylinder), and the exhaust valve is responsible for the exhaust gas after combustion in the cylinder. Outside control. The previous engine had only one intake valve and one exhaust valve per cylinder. This design was simpler and less costly, and the vehicle’s low-speed response was good, but the efficiency was poor at high speeds. Later, in order to improve the intake and exhaust efficiency, For vehicle performance, most of today’s engines use multi-valve designs. The most common is the design with 4 valves per cylinder. Taking a four-cylinder engine as an example, 4 valves per cylinder and four cylinders equal 16 valves. 16V seen in magazines or on the Internet.

The action of the valve is to drive the camshaft through the belt or metal chain connected to the camshaft by the crankshaft, and then the protruding part of the camshaft pushes the valve to open downward to carry out the action of intake and exhaust. As for the closing action, It is the responsibility of the valve spring. Nowadays, most valve springs are cylindrical spiral springs. Its function is to quickly return the opened valve to the closed position by relying on the tension of the spring, and prevent the valve from generating a gap due to inertial force during the movement of the engine, ensuring When the valve is closed, it can fit tightly, and it also prevents the valve from jumping and damaging the seal when it vibrates.

Since the valve and valve spring must work in harsh and harsh environments, especially the valve is directly in contact with high-temperature gas, the material must have sufficient rigidity and heat resistance. Today's valves are mostly made of JISSUH3 burn-in hardened special heat-resistant alloy, JISSUH36 (21-4N) high-grade heat-resistant alloy steel, STELLITE cobalt-chromium-tungsten alloy steel and other materials. Valve springs are mostly made of medium carbon chromium vanadium steel wire or silicon chromium steel wire, so that the spring has sufficient rigidity and fatigue strength to withstand frequent compression loads and maintain appropriate elasticity.