What Is Valve Oil?
The role of the valve is specifically responsible for inputting air into the engine and exhausting the exhaust after combustion. From the engine structure, it is divided into intake valve and exhaust valve. The role of the intake valve is to suck air into the engine and mix it with fuel for combustion; the role of the exhaust valve is to exhaust and dissipate the exhaust gas after combustion.
- Chinese name
- Valve
- The role of the valve is specifically responsible for inputting air into the engine and exhausting the exhaust after combustion. From the engine structure, it is divided into intake valve and exhaust valve. The role of the intake valve is to suck air into the engine and mix it with fuel for combustion; the role of the exhaust valve is to exhaust and dissipate the exhaust gas after combustion.
Valve function:
- The role of the valve is specifically responsible for inputting air into the engine and exhausting the exhaust after combustion. From the engine structure, it is divided into intake valve and exhaust valve. The role of the intake valve is to suck air into the engine and mix it with fuel for combustion; the role of the exhaust valve is to exhaust and dissipate the exhaust gas after combustion.
Valve composition:
- The valve is composed of a valve head and a stem. The temperature of the valve head is very high (intake valve 570 ~ 670K, exhaust valve 1050 ~ 1200K), and it also bears the pressure of the gas, the force of the valve spring and the inertia force of the transmission component. Its lubrication and cooling conditions are poor, and the valve must be Has a certain strength, stiffness, heat resistance and wear resistance. The intake valve is generally made of alloy steel (chrome steel, nickel-chromium steel), and the exhaust valve is made of heat-resistant alloy (silicon-chrome steel). Sometimes in order to save heat-resistant alloys, the exhaust valve head is made of heat-resistant alloy, and the rod part is made of chrome steel, and then the two are welded together.
- The shape of the valve head includes flat top, spherical top and horn top. Flat tops are usually used. Flat top valve head has simple structure, convenient manufacturing, small heat absorption area, small mass, and can be used for both intake and exhaust valves. Spherical top valve is suitable for exhaust valve. It has high strength, low exhaust resistance and good exhaust gas elimination effect, but it has a large heating area, large mass and inertia, and complicated processing. The horn type has a certain streamline shape, which can reduce the intake resistance, but its head has a large heating area, which is only suitable for the intake valve.
- The valve cone angle is the angle of the valve sealing surface, which is generally 45 °, and some are 30 ° (CA1091-type automobile 6102 engine). The 30 ° valve is considered to have the same lift, the valve taper is small, the valve passing end face is large, and the intake resistance is small, but because the taper of the valve head is thinner, the stiffness is small, the sealing and thermal conductivity are poor, it is generally used On the intake valve. The thickness of the edge of the valve is generally 1 ~ 3mm, in order to prevent damage to the valve seat during work or damage by high temperature. In order to reduce intake resistance and improve cylinder intake efficiency, most engine intake valves are larger than exhaust valves. Used intake and exhaust valves are also different in color.
- The valve stem is cylindrical and continuously reciprocates in the valve guide. The surface must be heat treated and polished. The shape of the valve stem end depends on the fixed form of the valve spring. The commonly used structure is two halves of the lock plate to fix the spring seat. The end of the valve stem has a ring groove to install the lock plate, and some are fixed by a lock pin. There is a hole for the lock pin. [1]
Valve Status:
- In order to improve the intake and exhaust efficiency, multi-valve technology is now used. It is common to arrange 4 valves per cylinder (there are also single-cylinder 3 or 5 valve designs, the principle is the same, such as the Audi A6 engine). There are 16 valves. The "16V" that we often see in the car data indicates that the engine has 16 valves. This multi-valve structure is easy to form a compact combustion chamber, and the injector is arranged in the center, so that the fuel-air mixture can be burned more quickly and more uniformly. The weight and opening of each valve are appropriately reduced, which makes the valves open or close. faster.
Valve material:
- Valve materials in China are usually divided into 40Cr, 4Cr9Si2, 4Cr10Si2Mo, 21-4N and 23-8N. 5Cr8Si2, 4Cr9Si3, 21-2N, 21-12N, 23-8N, XB, etc. have been used in large quantities on some imported models. High-temperature nickel-based alloys have also begun to be used in exhaust valves of high-load diesel engines. [2]