I. Overview
The connector plays an important role as an electrical medium connecting the power supply side and the demand side. Therefore, when selecting low-voltage electrical appliances for passenger cars, the best electrical appliances should be selected from the aspects of environment, temperature, humidity, installation location, vibration, dustproof, waterproof, noise, sealing, etc., and special attention should be paid to the design and test of the seal.
The connector consists of two parts, a male end and a female end. The female end is composed of a female body, a secondary lock (terminal), a sealing ring, a terminal, a terminal sealing ring and a cover. Due to their different structures, specific parts will have individual differences, but the differences are not large and can basically be ignored. The same connector is generally divided into long skirts and short skirts.

2. Harm
The low-voltage wiring harness is the nervous system of the car, connecting the electrical components of the car, and plays the role of power distribution and signal transmission. In order to ensure the stability of the wiring harness system, it is necessary to determine the corresponding protection design of the wiring harness in each area according to the working environment of the vehicle.
Assembly damage:
After riveting the terminal with the wire harness, the sealing lip was scratched when the waterproof plug was installed due to the poor riveting of the terminal.
The installation position of the waterproof plug and wiring harness is incorrect.
The waterproof plug was damaged before assembly.
The male/female sealing ring is not installed properly and the sealing ring is warped;
Design damage:
The design of the seal ring and the wiring harness interference is not good;
The design of the seal ring and the mother body interference is not good;
The design of the public and female waterproof plugs is not good enough;
The female end does not interfere well with the waterproof plug;

Three, design terms
The design input information is as follows:
a. Part type and hole number
B. Component part number
C. Overall size
d. Control size of parts (function key size)
E. Molding accessories
f. Surface finish of plastic shell
g. Plastic shell material
h. Diameter range and insulation type of wire for connector
i. Wire type (thin wall or thick wall)
j. Waterproof material
k. The base material and coating, size (thickness, material) of the terminal

test environment:
If there are no other requirements, the setting of test parameters should be accurate to the following range:
Temperature (+2 C) (only for performance test)
Temperature (+5 C) (only for temperature cycle)
Voltage (±1.5%)
Current (±1.5%)
b. The accuracy of all test instruments should be equal to or greater than 10% of the given tolerance.
c. The instrument should have a valid calibration indication, and its calibration requirements should comply with national standards.
d. If there is no special requirement, all units are international units.
e. When there is no special requirement, the temperature measurement unit is Celsius (?)
f. If there are no special requirements, the room temperature conditions for all tests are defined as (23(+5)C, and the relative humidity is between 45% and 75%.

Four, test method

Waterproof test: This test method is suitable for IP X7 connectors.

Test the waterproof characteristics as shown in the water-proof test. The aqueous solution is kept at room temperature and contains 5% salt and 0.1% wetting agent (washing salt) in the volume ratio of water.

Insert the sample into the water until the upper surface of the sample is 200 mm from the water surface.

Put the water basin and the sample into the vacuum box, reduce the pressure in the vacuum box to 60kPa and maintain this pressure for 30 minutes.

When the pressure in the vacuum box drops, it is necessary to observe whether the sample has gas escaped and record it in the test report.

Then increase the pressure at a rate of 2.5kPa/min until it reaches atmospheric pressure (minimum 90kPa).