In automotive electrical systems, connector sheaths not only fulfill the basic function of protecting internal terminals but also need to withstand complex operating conditions and environmental requirements.To meet the functional needs of different application scenarios, sheaths have developed a diverse classification system in design and use. Classification based on application location, protection level, structural form, and material type provides a clearer understanding of their characteristics and applicable scope, offering a systematic reference for selection and application.
Based on installation location, sheaths are mainly divided into wire-end sheaths and device-end sheaths. Wire-end sheaths are typically located at the end of the wire harness, mating with the crimped terminals of the wires to provide fixation and protection; device-end sheaths are installed on devices such as controllers, sensors, and actuators, forming a mating pair with the wire-end sheaths. The two differ in locking methods and external contours to meet different assembly space and mating frequency requirements.
Based on protection level, sheaths can be classified into open, semi-enclosed, and fully enclosed structures. Open-type sheaths provide only mechanical isolation and are suitable for dry, clean vehicle interior environments. Semi-enclosed sheaths, with added dust baffles or simple seals in certain areas, can be used in less demanding areas such as the dashboard. Fully enclosed sheaths, equipped with sealing rings or potting structures, can resist water spray, salt spray, and oil corrosion, and are commonly found in engine compartments, chassis, and high-voltage systems in new energy vehicles.
Structurally, sheaths come in inline, right-angle, multi-core integrated, and detachable/combinable types. Inline structures facilitate wiring harness routing along the vehicle body and occupy less lateral space; right-angle structures allow for turning wiring in narrow areas, optimizing assembly paths; multi-core integrated structures integrate multiple circuits into a single sheath, reducing the number of connection points and improving system reliability; detachable/combinable sheaths facilitate segmented maintenance and module replacement, offering significant advantages in large electrical architectures.
Based on material categories, sheaths are mainly divided into thermoplastic plastic sheaths and thermosetting plastic sheaths. The former, such as PBT, PA, and PPE, features high molding efficiency, a wide temperature range, and recyclability, making it suitable for mass production. The latter, such as certain modified phenolic resins, exhibits outstanding high-temperature resistance and flame retardancy, and is often used in high-temperature areas or applications with special safety requirements. In recent years, to balance lightweight and high strength, the application of carbon fiber reinforced composite materials has also been explored.
The cross-combination of different classification dimensions allows sheaths to meet a wide range of needs, from low-voltage signal connections to high-voltage power transmissions. Clearly defining the classification and its characteristics helps to accurately match vehicle operating conditions and service life requirements during the design and manufacturing stages, thereby ensuring the reliability of electrical connections while optimizing the maintenance convenience and overall cost of the vehicle system.
