Automotive connector is very common for electronic engineering technicians. Its function is very simple: it sets up a bridge of communication between the blocked or isolated circuits in the circuit. So that the current flows and the circuit realizes the predetermined function. As one of the connectors, the form and structure of automotive connectors are ever-changing. In addition, they have four basic structural components, namely: contacts, shells (depending on the types), insulators, and accessories. Get more details from this note about automotive connector overview and selection.
1 Automotive Connector
There are nearly 100 types of automotive connectors, and there are hundreds of connectors in a single model. As people have higher and higher requirements for safety, environmental protection, comfort, and intelligence in automobiles, the application of automotive electronic products is increasing, which make the number of automotive connector applications increase.
2 Basic Structure
There are four basic structural components that enable automotive connectors to act as a bridge to make cars run stably.
The contact piece is the core part of the automobile connector to complete the electrical connection function. Generally, a contact pair has a male contact piece and a female contact piece, then having the electrical connection with these two parts.
The male contact is a rigid part, and its shape is cylindrical (round pin), square column (pin) or flat (insert). And the male contacts are generally have brass and phosphor bronze. While the female contact piece is the jack, which is the key part of the contact pair. It relies on the elastic structure to elastically deform when it is into the pin to generate elastic force to form close contact with the male contact piece to complete the connection. There are many types of jack structures, including cylindrical type (split slot, necking), tuning fork type, cantilever beam type (longitudinal slotting), folding type (longitudinal slotting), box type (square jack) and hyperboloid wire spring jacks, etc.
The shell, is the outer cover of the automotive connector. It provides mechanical protection for the built-in insulating mounting plate and pins, and provides alignment when having the plug and socket, thereby fixing the connector to the device.
Insulators, are also often referred to as automobile connector bases or inserts. Its function is to arrange the contacts according to the required position and spacing, and to ensure the insulation performance with the shell. Good insulation resistance, withstand voltage performance and ease of processing are the basic requirements for selecting insulating materials.
Accessories have the structural part and the installation part. Structural accessories such as retaining rings, positioning keys, positioning pins, guide pins, coupling rings, cable clamps, sealing rings, gaskets, etc.
3 Design Criteria of Automotive Connector
With the rapid development, various functional parts and various components on the automobile are constantly developing in the direction of intelligence, refinement and reliability. You should also consider the structural design, appearance design, and material of automobile connectors. higher requirement. Automotive connectors must meet the USCAR-20 standard, which is the performance standard of automotive electrical connector systems.
Looking for A Better Automotive Connector
The contact surface of automotive connectors should always be reliable throughout the service cycle, including the following factors:
1) The material of the connector contacts is stable and reliable.
2) Positive force stability.
3) The voltage and current of the circuit are stable.
4) The temperature requirements are within the specified range, including the surrounding temperature and its own temperature rise.
5) Better robustness.
6) It must be the same as the connector used for high-speed and long-distance communication computers, and the automotive connector must be able to work reliably under harsh conditions.
7) Connector insertion force: below 20.5kg.
8) Connector retention force: 2.5kg or more.
9) Heat resistance: -40~120℃
4 Automotive Connector Development Trends
The “miniaturization”, “high speed” and “intelligence” of connector products are the trends of future development. The future technological innovation of the industry mainly has the following directions:
1) Miniaturization Development
This technology is mainly developed for the miniaturization trend of connectors, and can be applied to micro-miniature connectors below 0.3mm, which belongs to the new varieties of MINI USB series products. It can be used for multi-contact expansion card slot connectors, which can meet and exceed the strict requirements of multi-contact surface mount technology, with high accuracy and low cost.
2) Wireless Transmission of Automotive Connector
The high-frequency and high-speed wireless transmission of connector technology is mainly aimed at a variety of wireless device communication applications and has a wide range of applications.
3) Simulation Application Technology
It is based on a variety of disciplines and theories, using computer and its corresponding software such as AutoCAD, Pro/E program stress analysis software as tools, through the establishment of product models and corresponding boundary conditions, to its mechanical, electrical, high-frequency simulation analysis and confirmation of other performances, thereby reducing the cost of product development failure caused by factors such as material selection and unreasonable structure, improving the development success rate, and helping to provide support for the realization of complex system applications for products.
4) Connector Intelligence Technology
This technology is currently mainly used in DC series power connector products. Intelligent signal detection can be performed before power transmission to ensure that the positive and negative poles are turned on and the power is turned on after the plug is inserted in place. In the future, enterprises will need to develop similar intelligent technologies for other products because of the adverse consequences of arc damage and burn-in caused by conductive contact.
5) Precision Connector Technology
Precision connectors involve many aspects such as product design, process technology and quality control technology. The main technologies include the following aspects:
a. Precision Mold Processing Technology
Adopt CAD, CAM and other technologies, introduce high-precision processing equipment in the industry, and use personnel production experience and advanced equipment and technical means to achieve high-precision high-quality mold products.
b. Precision Stamping and Injection Molding Technology
Realize precise, efficient and stable all-round control and perfect surface quality of various stamping parts and injection molding parts to ensure product quality.
c. Automated Assembly Technology
Through the application of precision control technology, semi-automatic testing machine technology, etc., the problem of manual operation of precision products is overcome and the core competitiveness is improved.
6) Manufacturing Process Research
The competitiveness of products depends to a certain extent on the level of manufacturing technology. Continuously developing new manufacturing processes and improving existing production and processing technologies can greatly improve the manufacturing efficiency.
Automotive Connector Processing List
(1) Fine manufacturing process: This process is mainly aimed at technologies such as small spacing and thin thickness. Some companies have carried out research on the process of connectors with a spacing of less than 0.4mm. This type of technology can ensure that the company reaches the advanced level of the international industry in the field of ultra-fine manufacturing.
(2) Integrate development technology of light source signal and electromechanical structure. It can be applied to audio connectors placed in electronic components. By adding IC, LED and other electronic components to the audio connectors, which can also transmit analog signals and the function of digital signal.
(3) Low temperature and low pressure molding process technology. The sealing and physical and chemical properties of the hot-melt material are used to achieve the functions of insulation and temperature resistance.
5 Connector Selection
1) Electrical Factor
Current requirements: high current, low current, signal level;
They determine the type of terminal/size of contact segment/plating (0.64mm to 8.0mm pin and male terminal).
Wire diameter/insulation requirements: voltage drop and/or corrosion resistance, which determine the center distance of the connector.
Temperature: Engine compartment – sealed, ambient temperature >105℃; vibration, fluid compatibility, passenger compartment – unsealed, ambient temperature <85℃.
Sealing: Potential for high pressure jet/splash, potential for immersion, humidity; fluid type, sealed or not for device connectors.
3) Connector Standard
Standards: Customer Standards
Connector performance test requirements are included in system-level specifications. For GM, Ford and Chrysler are usually USCAR specifications, that is, engine-related applications have relatively high vibration requirements. Other OEMs generally have their own standards. What’s more, equipment-side suppliers are responsible for the performance of mating-side connectors.
4) Customer Preference
Preferred product strategy: Reduce cost of connector systems with different methods:
Ford: Design competition for door connectors.
Ford: Prefer terminal design/supplier (focus on contact interface).
General: Prefer the terminal design (focus on the hole position of the connector).
Chrysler: Strategies for favoring terminal/plastic Part suppliers.
5) Regional Preference
North America: USCAR Drawing/Performance/Design Criteria —Tangless Terminals, TPA, CPA regulations. In many instances the harness supplier has a significant influence.
Europe: Design influence of contact contacts/development with major OEMs; preference for two-piece contacts, even if cost pressures and North American porting operations force OEMs to consider U.S technology, that is, accepting Tangled contacts. Long-term relationships between OEMs and suppliers.
Asia: Traditionally influenced by Toyota. Focus on assembly ability that affects quality assurance; North America influences China to change the status.
6) Physical Factors
Such as size, number of circuits, mating position, wire harness docking or equipment connection, mechanical main features: levers, bolts; manual docking capability; multiple types of connectors for high input/output applications.
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