The automobile intake manifold is the intake pipe from the rear of the carburetor or throttle body to the front of the cylinder head intake port. Its main function is to distribute the air and fuel mixture from the carburetor or throttle body to the intake ports of each cylinder. It is an important part of the engine. Driven by the development trend of automobile lightweight, more than 90% of the recent manifolds are realized by the reinforced nylon of the modified nylon series. Why should the automobile intake manifold be made of modified nylon?

Intake manifold nylon

First, let's start with the advantages of the intake manifold made of modified nylon:

1) large degree of design freedom: the design of intake manifold is complex, while the modified nylon can realize the design of intake manifold through thermoplastic process.

2) cost reduction: the cost of modified nylon products is lower than that of aluminum products. The production method is mostly injection molding, vibration friction welding process and less molding process, so the production efficiency is high and the qualification rate is relatively high.

3) lightweight: the mass is only 40% of the aluminum intake manifold, which reduces the overall weight of the engine, thus saving fuel and vehicle mobility.

4) performance improvement: because the modified nylon intake manifold is injection molded, the inner wall is very smooth, which is very helpful to improve the intake charge. Because the thermal conductivity of the modified nylon intake manifold is lower than that of the aluminum intake manifold, the thermal expansion rate of the gas is lower, the density of the gas is increased, and the temperature of the gas entering the combustion chamber is reduced, which not only improves the hot start performance, but also improves the efficiency and torque of the engine.

5) the inner wall of the environment-friendly modified nylon intake manifold is smooth and the intake air is smooth, which can fully burn the fuel, reduce the generation of exhaust gas, reduce the emission of harmful exhaust gas, and recycle the waste parts of the modified nylon.

Carbon fiber reinforced nylon

Secondly, the automobile intake manifold puts forward higher requirements for the performance improvement of modified nylon: the modified nylon intake manifold requires that nylon must meet the performance requirements of high temperature resistance, high strength, dimensional stability, chemical stability and thermal aging stability at the same time.

(1) high temperature resistance: the modified nylon intake manifold is directly connected with the engine cylinder head, and the engine cylinder head temperature can reach 130~150 ℃. Therefore, the modified nylon intake manifold material is required to withstand a high temperature of 180 ℃.

(2) thermal aging stability: the automobile engine operates at a very harsh ambient temperature, and the operating temperature changes back and forth between 30 ℃ and 130 ℃. The modified nylon material must ensure the long-term reliability of the manifold.

(3) dimensional stability: the dimensional tolerance requirements for the connection between the intake manifold and the engine are very strict, and the installation of sensors and actuators on the manifold should also be very accurate.

(4) high strength: the modified nylon manifold is installed on the engine to bear the automobile engine vibration load, throttle and sensor inertia force load, intake pressure pulsation load, etc., and to ensure that it will not be burst by high pressure pulsation pressure in case of abnormal tempering of the engine. Therefore, the modified nylon used is required to have high strength.

Glass fiber reinforced nylon

Later, the modified nylon punctured product reinforced nylon became the main reason for the intake manifold:

　　1. Reinforced nylon has good injection processability

　　2. Reinforced nylon has good vibration friction welding performance

　　3. Reinforced nylon has excellent welding air tightness

　　4. Reinforced nylon has excellent blast resistance

　　5. Reinforced nylon has long-term aging resistance and high temperature resistance

　　6. Reinforced nylon is treated with special formula and has good resistance to freezing liquid

Conclusion: the main advantages of modified nylon intake manifold are low cost, light weight and superior comprehensive performance. As for nylon material, its thermal conductivity is lower than that of aluminum, and the fuel nozzle and incoming air temperature are lower, which can not only improve the hot start performance and improve the engine power and torque, but also avoid the heat loss in the pipe to a certain extent during the cold start, and accelerate the increase of gas temperature. In addition, the inner wall of nylon intake manifold is smooth, which can reduce the air flow resistance, so as to improve the engine performance. Under long-term high temperature conditions, It has stable thermodynamic performance and is a better choice for automobile intake manifold.

Source: Jiangmen engineering plastics http://www.wywantong.com/