Application of Typical Silicone Rubber Parts in Automobiles

Automotive rubber turbocharged hose

The application of turbocharged engines is increasing and the pressure is getting higher and higher, and the temperature of the gas through the pipeline is also getting higher and higher. High-temperature and high-pressure turbocharged hoses must use aramid fabric reinforcement, otherwise they cannot reach the strength required for use, especially the requirements for use at high temperatures. In order to reduce costs, some silicone hose manufacturers use nylon, vinylon or polyester reinforced layers, which have relatively low strength and high-temperature resistance performance. Since materials such as nylon, vinylon, and polyester cannot withstand temperatures above 200°C, if the usage temperature exceeds the limit of the material, it will cause the reinforcement fabric to come off, tear or even pulverize. Therefore, only polyester or nylon fabric reinforced silicone hoses can be used in occasions where the temperature is below 150°C. In addition, the reinforcement fabric in the silicone hose is manually wound.

If the tape winding method is used, attention must be paid to the width of the lap joint, otherwise it is easy to damage at the joint. It is advisable to use semi-automatic winding of the entire sheet as much as possible, reduce reliance on the proficiency of workers' operations, and ensure stable product quality. Since silicone rubber is not resistant to oil, and there is often oil and gas in the turbocharged hose, a layer of fluororubber layer or fluorosilicone rubber lining should be attached to the inner layer of the silicone rubber hose.

Automotive rubber radiator water hose

Silicone rubber radiator water hose is generally longer than turbocharged rubber hose and most of them are irregular in shape. It is difficult to use the entire sheet winding method during production, so special attention should be paid to leaving enough overlap width at the tape overlap (especially at the turning point) and increasing the width of the overlap to avoid damage under the repeated impact of hot water during use. Compared with the turbocharged hose, the reinforcement layer of the radiator water hose is less, with only 24 layers of polyester or nylon fabric reinforcement.

Automotive rubber disc brake liner sleeve

Disc brakes are small in size, light in weight, stable in heat resistance, small in water degradation resistance, and easy to achieve automatic clearance adjustment, so they are increasingly being used. Near the brake area, when frequent braking occurs, a high temperature will be generated, so a heat-resistant automotive rubber material should be used. When designing the silicone lining, excessive stretching should be avoided as much as possible. Because the strength of silicone rubber is low, tensile stress will cause early damage to the lining.

Automotive rubber gasket

High-temperature gaskets are generally coated with silicone rubber, and some gasket formulas also add silicone rubber to improve the heat-resistant performance of the product. Typical products include cylinder head gaskets, camshaft gaskets, engine intake/exhaust pipe gaskets, transmission gaskets, etc. In order to ensure the sealing performance, the cylinder head gasket is coated with silicone rubber.

Automotive rubber oil seal

Although silicone rubber is not resistant to oil, after modification, the oil-resistant silicone rubber still has certain performance advantages under high temperature conditions, so oil-resistant silicone rubber oil seals have been developed and applied to automobiles as special oil seals. The application range of full silicone oil seals is limited. The outer diameter of the oil seal that does not directly contact the grease includes polytetrafluoroethylene lip seals and dust-proof lips that use silicone rubber to apply oil seals more commonly in automobiles, especially the polytetrafluoroethylene seal used under high temperature conditions Crimping the outer rubber generally uses silicone rubber.

Since this seal ring is in contact with water on one side and oil on the other, if two seals are used, fluorine rubber can be used on the side of the oil seal and silicone rubber can be used on the water seal. If only one seal is used, silicone rubber must have certain oil resistance, and oil-resistant silicone rubber is preferred. When designing the seal ring, the rationality of the groove size should be considered to ensure a certain amount of compression after installation and use. Since the diameter of the seal ring is relatively large, when designing the compression amount, the excessive installation stretching of the seal ring, the expansion rate of the automotive rubber material after contact with the medium, permanent compression deformation performance, hardness, heat resistance or cold resistance The changes in size and hardness of the material should be considered.