Advantages and disadvantages of engine rubber mount technology
Rubber mounts; in modern vehicle design, . The engine is installed with elastic supports. This is called "suspension". Its basic functions are:
-Fix and support the vehicle powertrain.
- To withstand the reciprocating inertial forces and torques generated by the rotating and translating masses of the engine inside the powertrain.
-Withstand all the power acting on the powertrain while the car is running.
-Isolate the transmission of body vibrations caused by road surface irregularities and road shocks on the wheels to the powertrain.
The ideal engine rubber mount should have the characteristics of low frequency, high stiffness and large damping. To attenuate the low-frequency large-amplitude vibration generated by uneven road air pressure and engine idling. . In order to reduce the noise inside the car and improve the handling stability, it should have the characteristics of high frequency, small stiffness and small damping. Therefore, the rubber mounts are usually required to have frequency variation and amplitude variation characteristics.
There are various types of mounts for existing engines, mainly including rubber mounts, air spring mounts, hydraulic mounts, semi-active mounts, and active mounts. Each structure has its own characteristics and advantages and disadvantages. There are different applications at different stages of development.
Natural rubber NR
(Natural rubber) Made from rubber latex. Latex is a polymer of isoprene. It has good abrasion resistance, high elasticity, breaking strength and elongation. It is easy to age in the air, become sticky when heated, swell and dissolve in mineral oil or gasoline, and is resistant to alkali but not strong acid. Advantages: good elasticity, acid and alkali resistance. . Disadvantages: Weather resistance and oil resistance (vegetable oil resistance) are the raw materials for making tapes, hoses, and rubber shoes. They are suitable for making shock-absorbing components and products used in hydroxyl-containing liquids such as automobile brake oil and ethanol.
Styrene butadiene rubber
(Styrene-butadiene copolymer) Compared with natural rubber, the copolymer of butadiene and styrene has the advantages of uniform quality, less foreign matter, better abrasion resistance and aging resistance, but weaker mechanical strength. blend. . Advantages: low-cost non-oil resistant material, good water resistance, hardness below 70, good elasticity, high hardness, poor compressibility, disadvantages: strong acid, ozone, oil, oil ester and fat and most hydrocarbons are not recommended. Widely used in tire industry, shoe industry, cloth industry and conveyor belt industry.
Butyl rubber IIR
Butyl rubber is polymerized from isobutylene and a small amount of isoprene. Because the sterically hindered molecule of the methyl group moves less than other polymers, it has less gas permeability, high resistance to heat, sunlight, and ozone, and good electrical insulation. Resistant to polar solvents, generally used in the temperature range of -54-110 °C. . Advantages: Impervious to most general gases, resistant to sunlight and odors, contact with animal or vegetable oils or volatile chemicals. . Disadvantages: It is not recommended to use inner tubes, leather bags, rubber paste, window frame rubber, steam hoses, heat-resistant conveyor belts, etc. Used in car tires with petroleum solvents, rubber kerosene and aromatic hydrogen.