关键词: 高低温环境；挡位开关；高低温性能；工程塑料件耐高温等级；橡胶件高低温性能

Abstract: The gear switch is one of the import electrical components on the transmission, and its output signal indicates whether the transmission is hanging into the corresponding gear, which avoids a protective device that makes the vehicle rush forward when the gear is already in gear. The working reliability of the gear switch directly affects the driver's driving experience. Aiming at the problem that the gear switch used in heavy truck, by improving the temperature resistance grade of the engineering plastic parts inside the switch, optimizing the high and low temperature performance of the rubber parts and adjusting the internal strucure of the switch, make the gear switch meet the use requirements of the gearbox under complex environmental conditions.

Key words: High and low temperature environment; Gear switch; High and low temperature performance; Temperature resistance grade of the engineering plastic parts; High and low temperature performance of the rubber parts