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„Fast, flexible pin placement“

New stitching process for plug conectors

Bihler has developed the stitching process for manufacturing plug connectors. This is fast enough to permit the highly flexible insertion of up to 600 pins per minute. At the heart of this process lies the newly developed insertion module, which can be used on both a BIMERIC and a BMK-NC.

Whether in vehicles, computers or medical applications, plug connections are playing an ever more important role in the digital world and demand for them is constantly growing. The most commonly used connections take the form of cable-to-board, board-to-board and hybrid connectors in SMD, THT or also press-fit technology. They can contain straight pins, angled pins as well as blade and spring contacts. Bihler has developed the so-called stitching process for the assembly of these precision products. “Our stitching process was specially developed for the variable, extremely high-speed production of a wide range of plug connector types,” explains Kay Wesendrup, Key Account Manager Connector Industry at Bihler. “At the heart of the process is the stitching operation, that is to say the insertion of the pins at the housing. This can be done extremely flexibly and precisely thanks to Bihler’s high-performance servo technology.”

For the most varied layouts

The immensely high performance of the stitching process developed by Bihler can be clearly seen in the fact that a connector housing can be equipped with up to 600 individual pins per minute. Thanks to the combination of Bihler servo and control technology, the insertion/stitching process can be performed extremely flexibly irrespective of the orientation, number, grid dimensions and layout of the pins. Using the Bihler stitching process, it is therefore possible to assemble many different types and categories of housings, and selective pin layouts and insertion positions can be achieved without difficulty.

Pin insertion module at the heart of the solution

The pin insertion module lies at the very heart of the Bihler stitching process. This is responsible for handling the housing and actually inserting the pins. This NC-assisted process is performed both horizontally and vertically. More specifically, the process starts with the infeed of the contact housing (1), which is then placed in the workpiece carrier (2). The workpiece carrier and housing are then transferred to the pin insertion position. At the same time as this is happening, the carrier strip is moved forward and the pin is separated or removed from the strip (3). The pin is inserted in the intended position in the housing before the housing itself is then rotated and the second row is inserted. The fully assembled housing is then removed from the workpiece carrier again and exits the process (4).

Full automation also possible

The pin insertion module and, therefore, the entire Bihler stitching process can be integrated without difficulty in a BIMERIC servo production and assembly system, for example. However, Bihler has also developed the BMK-NC for such applications. This constitutes the basic machine and comprises the machine bed, the electrical equipment and machine controller, the strip feed module for feeding the pre-stamped pins, a press module containing the separating tools and the pin insertion module for stitching the pins in the horizontal and vertical directions. The basic machine can then be equipped with various modules from a sort of application toolkit in order to meet customer-specific needs in the field of plug contact assembly. Thanks to the modular structure, multiple BMK-NC units can be arranged next to one another, consequently making it possible to machine different pin lengths and thicknesses depending on the complexity of the plug connector in question. The BMK-NC can also be equipped with application modules to permit the fully automatic production of large runs.


Kay Wesendrup
Key Account Manager
Connector Industry



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