Turbocharging is a technology that uses the exhaust gas generated by the operation of an internal combustion engine to drive an air compressor. The main function of a car turbocharger is to increase the amount of air intake into the engine, thereby increasing the engine's power and torque and making the car more powerful. However, after supercharging, the pressure and temperature of the engine during operation are greatly increased. Therefore, while using turbocharging technology on the engine, material advancement is also critical.


Performance requirements for hoses used in turbocharger systems

High temperature resistance

The turbocharged gas undergoes compression and severe friction to produce high temperatures, and even the cooled gas temperature generally reaches over 100°C. Therefore, the hose materials used in turbocharging systems must be able to withstand higher temperatures. Ordinary natural rubber, styrene-butadiene rubber, and butadiene rubber cannot meet the requirements for use under high temperature conditions, and high-temperature-resistant special rubber materials must be used. As the turbocharger pressure increases, the temperature of the gas passing through the pipes increases. If the pressure reaches 3.5×105Pa, the temperature of the gas passing through the pipeline can reach over 250°C, and there are only a few types of rubber that can be used in such a high temperature environment.

Oil resistance

The gas passing through the hose of the turbocharger system is generally mixed with oil and gas, so the hose must have certain oil resistance, especially oil resistance.

Performance of high temperature oil and gas. Some rubbers with good high temperature resistance (such as silicone rubber) have poor oil resistance, so it is necessary to add a lining layer to the inner wall of the silicone rubber tube to prevent the erosion of oil and gas.

strength

The turbocharger system not only has high temperatures, but also has a certain amount of pressure, especially the high-temperature section of the pipeline that bears relatively high pressure. Although

Turbocharger hoses generally use reinforced hoses (the main pressure-bearing part is the reinforced layer), but the rubber is also required to have a certain strength to improve the overall strength of the hose; in addition, in order to meet the needs of the production process and use and assembly, the rubber is also required to have High tensile strength and tear strength.

Compression set

Generally, the turbocharger hose is connected to the metal pipe through a clamp to form a pipeline. At high temperatures, rubber should have good resistance to deformation. Otherwise, excessive compression permanent deformation will cause the clamp to loosen and the hose to fall off, causing quality accidents.

cold resistance

Although the hose is used in a high temperature environment after the engine is started, the hose is exposed to cold air after the engine is stopped. engine

When starting at low temperature in cold areas in winter, the rubber hose vibrates at low temperature. If the rubber's low temperature resistance is poor, the hose will become hard and brittle, leading to problems such as tearing, falling off, and loss of vibration damping function.

Adhesion strength

The rubber layer of the hose should maintain good bonding with the reinforcement layer and lining layer in harsh environments such as cold, heat, oil and gas, and have a certain adhesion strength to ensure that delamination does not occur. The adhesion strength is related to the characteristics of the rubber itself and the rubber formula. It is also closely related to the impregnation pretreatment method of the reinforcement layer, the selection of the adhesive and the bonding process, and should be fully considered.

hardness

The rubber should have the right hardness. If the hardness is too high, the rigidity of the hose will be too large and it will not be able to dampen vibrations, and it will be difficult to assemble and easy to fall off. If the hardness is too low, the strength will be difficult to guarantee.

Turbocharger hoses are commonly lined with rubber - fluorosilicone rubber
Since the inner lining of the silicone rubber tube of the turbocharger system is in direct contact with high-temperature harmful gases such as exhaust gas, the inner lining rubber is required to be resistant to high temperatures, lubricating oil, and fuel, and to have good adhesion and processing technology with the silicone rubber. performance. On the basis of maintaining the excellent properties of silicone rubber such as heat resistance, cold resistance, insulation and weather aging resistance, fluorosilicone rubber introduces fluorine-containing groups to make it have a certain degree of oil resistance, acid and alkali resistance and other fluorine-resistant properties. Properties of rubber. Fluorosilicone rubber has good bonding properties with silicone rubber and is generally used as the inner lining of silicone rubber pipes to block oil and gas in the system to avoid erosion of the silicone rubber.

Special fluorosilicone compound for turbocharger tubes