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The importance of foamed silicone sealing rings in new energy vehicles
With the implementation of the new energy vehicle plan, the electric vehicle industry as a whole has been rapidly improved in quality and quantity. As a power source component of new energy vehicles, the safety performance of power batteries directly affects the safety of vehicles and people. According to the national standards, the protection level of the power battery box shell should meet the design requirements of IP67, and should maintain the sealing and waterproof performance.
Nov 8th,2023
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Analysis of waterproof failure mode of power battery
1, foam silicone sealing ring waterproof failure
As an indispensable part in the design of the sealing structure of the power battery, the foamed silicone sealing ring is matched with the mounting surface of the upper and lower shell of the battery to ensure the sealing of the power battery. The closed material of foamed silicone rubber as the main component of foamed silicone sealing ring, and PET double-sided tape, surface treatment agent and other processing and adhesive, cut into a fixed frame form of O-type foamed silicone sealing ring. Compared with the traditional carbon foam material, it has excellent compression resistance to permanent deformation performance, good resistance to high and low temperature, high flame retardant, and excellent aging resistance and weather resistance, is an ideal choice for all kinds of high-performance sealing, shock absorption, buffering, sound insulation, protection,
The waterproof failure of foamed silicone sealing ring can usually be attributed to:
1) the external water pressure is greater than the compressive stress of foamed silicone;
2) The load of water pressure on foamed silicone is greater than the friction between the foamed silicone sealing ring and the power battery box;
3) The excessive compression deformation of the foamed silicone seal ring causes its compression rebound to fail under various complex working conditions and cannot be effectively sealed.
In the process of selection and use of foamed silicone seals, the compression deformation, suitable friction force, good volumetric gap ratio and environmental tolerance of foamed silicone seals should be comprehensively considered.
2, electrical connector waterproof failure
As the input/output medium of the power battery, the sealing of the high and low voltage electrical connector directly affects the overall waterproof performance of the power battery. The waterproof failure mode of the high and low voltage connector is as follows:
1) the Vickers hardness at the power battery connector socket is too low;
2) connector and socket, socket and box flatness and compatibility is poor;
3) Low pressure communication pin position seal failure ;
4) High and low voltage connector plug O-type foam silicone sealing ring extrusion during the process of irreversible deformation.
In addition to the above common waterproof failure modes of electrical connectors, there are also problems such as connector quality problems and lock failure after frequent insertion and removal.
