Analysis on the Design Specifications of Automotive Wire Harness Connectors

The connector is also called the plug-in connector, which is a common component used for transmitting current or signal in the car.

Connectors can be divided into three categories: airtight (used in vehicle wet area), non-sealed (used in vehicle dry area), and safety-related (airbag-related). At the beginning of the design, PIN needles with different widths are selected according to the current size of each PIN needle, and then a cavity for accommodating different PIN needles is formed on the connector, thereby forming a Housing that accommodates multiple PINs.

This article analyzes and explores the design ideas at the beginning of the connector design from the several different appearance structures of the Automotive connector Seal and the assemblability of the plastic shell. They are, CPA, the secondary locking mechanism of the plastic shell. (Connector Position Assurance); Lever/Slider (lever), auxiliary mechanism; waterproof sealing ring; TPA (Terminal Position Assurance), terminal secondary locking mechanism; Cavity, terminal chamber.

Housing + CPA + sealing ring + TPA

First of all, CPA, its function is to ensure that the buckle of the locking mechanism will not easily exit after the plastic case and the electrical interface are assembled in place. Due to its functional particularity, the CPA must be designed to ensure the operability and identification of the workers This requires that the CPA must be an independent organization on the plastic case and must have a special color mark.

Wire harness Seal

Lever/Slider, auxiliary installation mechanism. For VW or GM, the boundary requirement of using auxiliary installation mechanism is whether the force of the plastic case is greater than 75N. Like CPA, due to its functional characteristics, special colors must be used and it is on the plastic case It is an independent institution. One thing that needs special explanation is that the plastic case with Lever mechanism must use a guiding mechanism that can guide the lead wire at the end of the plastic case to ensure that the Lever will not scratch the wiring harness;

Waterproof sealing ring: There are two kinds of waterproof sealing mechanism, one is used for sealing between plastic case and plastic case, and the other is used for sealing of terminal lead wire. As for the sealing mechanism, heat-shrinkable materials are never allowed to be exposed to the outside of the plastic shell mechanism to prevent accelerated aging. For the sealing mechanism between the plastic case and the plastic case, it is generally not allowed to use the convex point mechanism to fix the sealing ring. The product line of the convex point mechanism after the aging of the waterproof mold causes water leakage; for the terminal lead sealing structure, the single-line sealing type or The integrated gasket type structure, it should be noted that the gasket type terminals of the integrated gasket machine need to use special structure terminals (VW called clean body). The special structure of the waterproof terminal will scratch the gasket and cause the waterproof effect to deteriorate.

TPA (Terminal Position Assurance), terminal secondary locking structure. Not all terminals need a secondary locking structure. The VW requirement is that the terminal width is 2.8mm (including 2.8) or less. TPA should be used to ensure that the wiring harness factory workers install Convenient, the color of the TPA is also required to be identifiable, and there must be a clear hand feeling during assembly. To ensure that the TPA will not automatically enter the locked position during transportation to the wiring harness factory, the anti-locking mechanism is necessary on the TPA of.

Cavity, the terminal cavity, the plastic case containing the terminal mechanism, in order to ensure that the electrical circuit is clear and reliable, the cavity must be numbered on the plastic case. Some OEMs are defined by ABCD, and some are defined by 1234. In order to ensure the operability of the wiring harness factory workers, the terminal should enter the locked position smoothly when entering the chamber. Forced push is never allowed. This may cause damage to the key mechanism of the terminal, and the terminal should not be used When the auxiliary tooling is pushed into the plastic case, the pushing force is generally not more than 15N, and the GM requires 30N. After the terminal is pushed in, the top of the chamber needs to ensure that the terminal is not damaged under the force of 30N. GM requires 50N. If it is not satisfied, the special mechanism design to protect the chamber from being damaged needs to be considered.

After the introduction of all the mechanisms, there are also some requirements for matching the plastic case with the electrical equipment after it is attached to the wire harness. For example, when the wire harness plastic case is inserted into the device end, the PIN pin on the device end must not be damaged, which requires the device port There is a sufficiently long guide mechanism to ensure that the port PIN needle will not be damaged when the wire harness plastic case is inserted; the plastic case is required to be a complete mechanism as much as possible when assembling the terminal in the plastic case harness factory, and only the worker is required to push the TPA into the locked position. Try not to divide it into multiple organizations, which will hurt the people and money; the hand feel that requires assembly force during OEM assembly must be good, which requires the FEA simulation of the supplier to be in place during development.

The plastic case is the core key component of the Wire harness Seal. Any small problem may cause electrical equipment to fail to work properly. Therefore, it is necessary to invest as much energy as possible to develop and ensure its quality.