Introduction
You have read all of the connector directory, found Satisfy all of your design standards and fully suited to your application's connector. Correct rated current, rated voltage, circuit size, and then together, line capacity, structure, termination methods and security features, such as being locked, completely independent of contact, polarity and agents eligibility requirements are met, then In short, you find the perfect connectors.
But not completely to grow when in one breath, especially if you choose to use press-fit connector system. Although this may be the fastest, most reliable and solid termination one of the methods, if the terminal is not correctly crimp on the cable, you'll forget to choose the correct connector on hard work all paid. Although there are 13 common questions would reduce the press-fit your product reliability, but only some small knowledge and pre-planning can be easy to avoid these problems.
First of all, know terminal has three main parts: plug-in zone, transitional zone and press-fit zone (Figure A), which help us understand. As the name suggests, plug-in terminal area and the other half are connected terminal plug part. In part by the connector designer with docking terminal joint, and to a certain way. If the process of press-fit interface deformation, will reduce the performance of the connector.
Designed as a transition zone in the same press-fit process will not be affected. If you change the flexible plates or terminal position of the mouth only, the same will affect the performance of the connector.
Press-fit Design District is the only process affected by the press-fit part. The use of connector manufacturers recommend termination equipment, clamp crimping zone, thereby firmly connect with the cable. Ideally, you will crimp terminals on cable at all happened only at Press-fit zone.
The correct implementation of the Press-fit examples see (Figure B). Press-fit zone insulation insulating layer compression, but not punctured. Line core (or wire brush) out in the conductor crimp area anterior distance of at least equal the diameter of cable conductors. For example, 18 AWG cable should extend at least .040. "Conductor in the insulation and crimping part of the district can be seen between the insulating layer and conductor. Conductor crimp area at the introduction of client and the end was flared, and the transitional zone and seam zone at before and after the crimping process has always remained unchanged.
If you look the press-fit terminal and (Figure B in different terminals, it may be because in the crimping process errors. Here are press-fit process that may occur in the 13 most common questions, as well as how to avoid them.
1. Crimp height is too small
Press-fit guide body height are press-fit zone at press-fit after the cross-sectional height, it is a good press-fit the most important characteristics. Connector manufacturers to provide the design for the terminal for each cable size crimp height. Given the correct cable crimp height range or tolerance may be small up to 0.002. "In such a strict norms, testing whether the crimping machine is set up correctly for good compression is very important.
Too small (Figure I) or too large (Figure II) a high degree of press-fit can not provide the required compression strength (on the wire retention terminal), will reduce the cable pulling force and the rated current, under normal circumstances also give rise to pressure joints in a non-normal under the conditions of job performance. Too small a high degree of press-fit pressure will break or fracture of the core conductor crimp area of metal.
2. Crimp height is too large
Excessive crimp height can not be the correct line-core compression, caused by compression of the void area is too large gap, because the metal core and the terminal does not have enough metal between the contacts.
Problem # 1 & # 2 the solution is simple: adjusting crimping machine crimp on the conductor height. At the first use of press-fit plane of the use (Figure B), as shown in the vernier caliper or micrometer test crimp height at the specified scope, and in the course of their work should be in accordance with the requirements of a re-examination of the frequency in order to maintain the correct a high degree of press-fit.
3. & 4. Insulation crimp area is too small or too large (Figure III and Figure IV)
Insulation type and thickness because of the diversity of connector manufacturers generally will not provide the insulating layer of a high degree of press-fit. Press-fit for the conductor insulation crimp provide stress release, it will not bend in the cable core so that a broken line. Too small insulation crimp area will crimp insulated metal stress zone is too large, reducing its stress release function.
Most types of crimping tools can be independent of the conductor crimp height adjust the insulation crimp height. Regulation makes the correct clamping terminal insulating layer at least 180 degrees, and does not puncture the insulating layer. At terminal crimping pieces of insulation and the outside diameter of the outer diameter of cable insulating layer close to the same, the best way is to IDT technology.
5. Loose core
Loose core (Figure V) is press-fit, another common cause of problem. If all the line core is not completely closed on the conductor crimp area, press-fit pieces of the intensity and current load capacity will be greatly reduced. To get a good press-fit, you must meet the connector manufacturer specified crimp height. If not all lines of the core crimp height and crimp strength play a role, then press-fit performance parts will not be able to meet the requirements. Generally speaking, the loose line core questions are easily resolved, simply re-list systematically cable bundles, and then inserted into the terminal press-fit to Medium. If removed from the cable insulating layer on a separate process, in the course of treatment or cluster may not be accidentally separated from the core line. The use of strip and maintain the process to remove the insulating layer, so that insulation does not completely set up from the cable removed, until ready to use terminal crimping cable at up to help reduce the lines to maximize the core problem of loose problem.
6. Strip length is too short
If the strip length is too short, or did not fully insert the cable conductor crimp area, termination may not be able to achieve the required drawing force, as between the cable and terminal contact metal is reduced. Such as (Figure VI), as shown in the strip length of cable is too short (Note that the insulating layer in the correct location), extending conductor crimp area anterior distance not have access to the requirements of a cable outside diameter. Solution is simple: increase the length of strip strip equipment provided to the terminal value.
7. Cable inserted too deep
And too short length of the strip, another press-fit problem, appears in the cable into the compression zone depth cases. Such as (Figure VII) below, the insulating layer to move too deep to insert the insulation crimp area, the conductors extending to the transitional zone. In practice, this may lead to three kinds of failure modes. Because one of the two conductors are press-fit metal contact area reduction, the rated current and lower cable pulling force. Metal and plastic contact is not solid metal contact, but it is not conductive.
The third failure mode at the connector joints that may arise. If the cable extending to the transitional zone too deep, pin terminal collision on the cutting-edge cable may prevent the connector fully in place, or may lead to bending pin or socket terminals. This situation is called terminal collision.
In extreme cases, even if the terminal to be fully in place in the shell, but will be the introduction of the back shell. To resolve this problem, confirmed that no use of excessive force to insert the cable crimping machine so as to cross the wire crimping machine only I, or adjust the location of cable I just correctly so that the axial positioning of the lines have been skinned cable.
8. "Banana" (excessive bending) terminal
Press-fit the image of one of the issues referred to as the "banana" Press-fit (Figure VIII), because press-fit terminal was the shape of bananas. This makes it difficult to insert shell terminal, the terminal may cause a collision. Is easy to solve this problem, adjusting crimping machine restrictions on the location pin. This small pin crimping machine is located, in the press-fit zone at crimping cable terminals on the junction when the contact area. At press-fit process, the terminal end of a large number of metals (in press-fit zone) mobile. Such a large force tended to be forced to bend the front of terminals, unless the appropriate "restricted sales" by that restriction.
9. Ballast to take over at the top
A more obvious problem crimping the transition zone are partially damaged, such as (Figure IX) as shown. Icon at the terminal, the vertical part of the process are referred to as "terminal only the mouth" of the design features. Its function is to prevent too deep to insert a terminal shell. If only I were completely damaged, the actual terminal has to be pushed through the shell.
Solution is relatively simple. Caused this problem is due to terminal and metal article (from the manufacturer when you received the goods terminals connected by metal strips) compared with the crimping machine location is not correct. Just relax interchangeable tool substrates, and then re-aligned crimping machine, you can solve the problem.
10. Bell is too small
Horn (Figure X) are close to the correct size terminal material thickness of 2 times. For example, if the terminal by the thickness of .008 "of material, bell should be about .016." Although a few thousandths of inches at the nature of the deviation will not affect the terminal on the performance, if the lack of bell, or less than the terminal material thickness, there will be dangerous to cut off the line core. Reservations core to reduce the termination strength will be reduced. Calibration of the problem to confirm on the press-fit equipment and Anvil Punch the correct alignment.
11. Bell is too large
If the bell is too large problem will arise (Figure XI), because this will reduce the terminal crimping cable contact areas and the total area. Cable with the terminal contact surface of the smaller, the smaller the cable pulling force. If the crimp height is correct, then the tool may be due to the problems caused by wear and tear should be replaced.
12. Tailings is too long
At press-fit process, the tailings from the terminal on cutting down. If the reservation is too long tailings (Figure XII), there will be questions. When the terminal insert shell, the long tail of the metal is expected to extend to the rear connector, imposed at a higher voltage caused by the connector between adjacent contact arc. If the terminal end of the front of material is too long, would interfere with the splice connector and give rise to "terminal collision."
Solution is relatively simple. Crimping Machine regulation on the substrate, so that terminal crimping machine at the right center. Terminal is not correctly marked by the middle of another bell is not correctly formed. This occurs because the end of feed horn with a tool relations with space.
13. Barb bending
Despite the barbed bending is not necessarily incorrect crimping process, but the connector will still be invalid. Barb (Figure XIII) may be inward or outward bending over, which will affect the terminal completely locked into the plastic shell capacity. Barbed damage may be due to the terminal from the reel to start up, the press-fit fixation machine shaft on the friction wheel too tight, or it may be press-fit in the cable terminal on arising after removal. Termination of the cable are usually tied into bundles will, inventory or transport to another location of factories. Banding at the course of, or termination of each cable has been removed from the wiring harness, the barb may also be curved.
If you are in the crimping machine are damaged, then the necessary adjustment of the tightness friction wheel, just keep scrolling terminal will not launch because of its self-respect can be. If the problem lies in the banding process, required the use of a smaller harness or improved handling procedures.
Guidelines
Despite the press-fit process may lead to 13 kinds of questions, just comply with the four simple guidelines can help ensure the success of connector applications:
1. For your application requirements to choose the correct connector.
2. The use of terminal manufacturers specified crimping tool.
3. The right to regulate and safeguard the crimping tool to make it in good working condition.
4. The regular replacement of replacement of metal parts (such as conductors and insulators, punch, and the terminal Anvil cutting knife).
