What are the uses of different types of silicone hoses?
Cooling hoses are used in automobile engines, pressure accumulators, auxiliary heat exchangers (AT F) and automatic transmissions (CVTF), and internally pass engine oil, ATF, and CVTF coolant liquid. Since it is mostly in a compact engine room, in order to ensure that the coolant liquid can flow smoothly through the manifold and valve body, the cooling pipe is often made into a branch-like structure. At the same time, affected by the engine’s high-temperature radiation and long-term oil immersion corrosion, material aging has become the most serious problem, which often develops from the inside to outside, leading to leakage and malfunction. For this reason, the inner and outer rubber layers of the hose are mostly ACM and AEM, and the reinforcing layer is polyester fiber, and the traditional sleeve vulcanization in a vulcanizing tank is changed to a flatbed press vulcanization of a molding process.
As an important part of the automobile, the automotive silicone hose is distributed in the engine, chassis and body, and plays the role of transporting oil, gas, water and power, which is related to the safety and performance of the automobile. At present, a car needs at least 20 m silicone hoses, and the number of hose assemblies for luxury cars has reached more than 80 m, and there are no less than 10 types. Automotive silicone hoses have straight and special-shaped tubes in shape, high pressure, low pressure, and vacuum in pressure, oil and water vapor, heat-resistant and heat dissipation, refrigeration and cooling in media properties, and applications such as braking, drive, boosting transfer, etc. The type has become the representative of the advanced technology of today’s hose, and the exhibition hall of various new hoses is constantly moving towards the high-tech field. In terms of structure, in the past, various forms such as cloth clamping, weaving, and winding coexisted. Nowadays, most of them have been braided, almost all of which are connected short pipes less than 1 m.
The brake hose is the most critical safety component of the automobile brake system. It is required to be foolproof, and it must be strictly ensured that no leakage or malfunction occurs. Therefore, the safety factor of its burst pressure is 50% to 100% larger than that of general rubber hoses. The working pressure of the pneumatic brake silicone hose is reaching 5-8 times. The reinforcing layer is made of vinylon and polyester fiber. The use medium is compressed air, the inner rubber layer uses SBR, CR, and the outer rubber layer uses CR, CR/EPDM. The reinforcing layer of the hydraulic brake silicone hose is made of rayon and aramid fiber. As the medium used is mostly synthetic hydraulic oil, the inner rubber layer is usually NBR and the outer rubber layer is CR.
In recent years, due to the emergence of insurance-free luxury cars, a large number of high-boiling brake fluids and brake systems have been used, and the temperature of the working environment has increased, brake pipes have begun to use oil-resistant and heat-resistant rubber materials, such as The consumption of EPDM, CSM, CPE, ACM and HNBR is increasing. Among them, EPDM has become the mainstream of pneumatic pipes and HNBR as hydraulic pipes. Some of the reinforcing layer is also changed to nylon fiber, which raises the grade of the brake tube to a new level.
The heat radiator hose is a flexible hose connecting the automobile engine and the radiator, and is a key component in the automobile flexible pipeline. The conveyed fluid is cooling water, the pressure is not high, generally rayon, polyester fiber is used as the reinforcing layer, and the inner and outer diameters are often mainly sBR and CR. In recent years, due to the increase in engine compartment temperature (increased by l 5-50°C), automobiles are developing in the direction of energy saving and low pollution, and they are required to be able to adapt to the conditions of extreme low temperature in the field. Most of the rubber used in automobiles has been upgraded to EPDM. And change from ternary EPDM to binary EPM to improve the heat resistance and weather resistance of the hose, and achieve the service life of the same machine as the car. In addition, the same type of heater hose is now developing in the same direction.