The discharge valve is part of the internal combustion engine. Ensures that the exhaust gases are released from the combustion chamber.
The combustion chamber shall be leakproof when the fuel has been flashed. Once the flash energy is exhausted, the cells need to remove the exhaust, fill it with air and petrol, and prepare for a new flash. To remove the exhaust gases in the head, the cylinder is fitted with plates that provide reliable sealing of the combustion chamber when they are closed.
Vour valve design
The discharge valves are located in the cylinder head. The intake of air-fuel-air mixture into the cylinder is subject to a vacuum in the combustion chamber and the release-under conditions of increased pressure. This means that after the combustion gases are sought to leak out, it is sufficient to open the valve for release. So, by the way, the vents are always smaller than the intake-the suction force of dilution is inferior to the force of the pressure that is pushing the gases out.
The valve mechanism requires fine-tuning. If the valve is closed too soon, the underburned gas will burn it very quickly.
For reliable sealing of the combustion chamber in all modern engines the plates valves are used. There are several advantages to this design. A valve made of a plate and a rod, is simple and reliable as a nail. The transition from the fasque to the rod has been performed smoothly, which gives the valve the necessary strength. In addition, the conical form of the transition contributes to the reduction of the resistance of gases and the improvement of sealing.
Operating principle of the vent valve
The outlet valve opens from the power of the distribution shaft. The back-forward movement of the valve is carried out in a box that is compressed into the cylinder head.
There is a valve seat in the head. In essence, this is a depression whose shape corresponds to the shape of the upper part of the plate. The meal and the plate of high accuracy are tidled together. This excludes gas outbursts from the combustion chamber at a time when the valve is closed.
When the first plate is cracked, the process of destruction becomes a chain reaction. The larger the crack, the greater the overheating from the surface of the unburned fuel
The top part of the valve of the discharge valve has a point. It establishes a "Suhari" cut by two halved conical ring. They're holding a spring plate on the valve. The spring creates the necessary force to return the valve to the closed position.
Individual motor vehicles have a special mechanism to force the shut-off of the valve. This ensures that the details are evenly worn.
The exhaust gases are released when the piston of the cylinder is moving from the lowest dead point to the top. The DMF leave valve operates under increased pressure. The valves are able to heat up to 800 degrees during engine operation.
Characteristics of discharge
Aggressive waste gases cause corrosion of exhaust outlets. The products of incomplete combustion of the fuel lead to burnout.
After a certain period of operation, the plate of the exhaust valve and the saddle at the head of the unit shall be covered by the tan.
High temperature's heating up. The exhaust valve surface is burned. This entails the loss of tightness. Engine disruptions: power down, engine starting to be difficult. The resulting slits are precipitating under pressure of hot, unprocessed gases. This further heats the head of the valve. The result is the deformation of the head and the destruction of the valve. When the valve is destroyed, the cylinder's operation is in fact terminated.
Methods of protection against overheating
To withstand overheating, the vent valves are made of heat-resistant steel (chromnikylwolmmolybdenum steel).
When replacing the damaged valve, the berk is absolutely mandatory. If the valve doesn't clean, it'll have to change again, and very soon.
The base of the alloy is nickel. This metal increases the resistance of the valve to mechanical deterioration. Since the valve is subject to a higher thermal load than intake, it has a different structure. The valve of the valve shall be made to the floor. The inside of the cavity is filled with metal sodium. This is necessary to improve the heat exchange.
Modern technology provides an opportunity to further protect the vent valve from aggressive exposure.
The most universal method is smelting powder. In addition, there are laser alloying methods and high frequency currents. These methods of protection increase the cost of the details, but significantly extend the period of its service.
