Insights - Article - Featured
“Ready for Automation” in cable set production
Insights - Article - Featured
“Ready for Automation” in cable set production

The automation of cable set production is gathering speed. ITW Automotive’s Plastic Fasteners Division can support this process with an innovative production concept for bonded fasteners. It is characterized by a high level of standardization, continuous validation of the process chain and numerous cost and process benefits.

The vehicle electrical system is one of the last disciplines in automotive manufacturing which is not manufactured automatically. The size and complexity, the large number of varieties and the flexible structure of vehicle electrical systems were previously arguments against robot-assisted manufacturing.

However, the economic and geopolitical upheavals that have taken place over the last few years have motivated automotive manufacturers and vehicle electrical system suppliers to bring cable set production closer to vehicle production again in order to boost supply chain resilience. This requires automated systems, though, as only by using these systems can cost and quality targets be met. ITW is able to provide a decisive impetus for this type of automated production with a production concept for bonded fasteners.

ITW has developed a fully automated and fully validated production concept for bonded fasteners.

Reliable processes

ITW’s continuous process concept is fully validated, for example the interactions of an adhesive bond with various types of winding tape available on the market. Particular attention was paid to process reliability, cost efficiency and the locator geometry to ensure machine-compatible processing. Simplified automated prototype production enabled the proof of concept. Key steps in the fully automated process include:

  • Separation of the locators delivered as bulk goods into a vibratory bowl, for example
  • Picking up of the locator by the setting head at the end of the in-feeding conveyor
  • Plasma pretreatment (=cleaning) of the adhesive surface
  • Application of the hot adhesive on the curved contact surface
  • Placing of the locator on the taped wiring harness using a robot.
Picking up of the locator using the setting head (left), adhesive application (center) and the mounting of the cable set (right) are carried out fully automatically.

Standardization provides flexibility

ITW integrated several beneficial design details when designing the concept. For example, the locator has two standardized contact surfaces for the vacuum gripper ‑ regardless of the geometry of the connecting element. Various locators can therefore be handled on one cable set with a single standard setting head. Alternatively, they can be combined with manual winding technology in an initial step, and later either with an automated winding process or as a standalone adhesive bond. The adhesive selected ensures holding forces of up to 600 Newtons ‑ depending on the winding tape materials. This holding force is significantly above the force required of around 100 to 150 Newtons.

Thanks to the gluing robots’ modular design, the assembly line can be individually adapted to customers’ needs.

Modular expansion

Flexibility and modularity play a key role for cable set producers. With ITW adhesive technology, automated production lines can easily be expanded with separators, robots and setting heads, for example in order to shorten cycle times or to place additional locator variants on the same wiring harness.

Compared to previous fastener solutions – primarily cable ties and adhesive tape – bonding is a relatively simple and fast process with a high level of reliability and comparatively low investment costs. The small locators and the streamlined setting head can be easily inserted into narrow gaps between the mounting panel and the wiring harness, thereby ensuring good all-round accessibility. Competing concepts require significantly more space. Furthermore, a bonded locator can be placed with significantly reduced distance to an interference contour than is the case with competing processes.

On the path to series maturity

When developing the wiring harness, the ITW adhesive technology enables greater design freedom than competing concepts and is significantly more inexpensive. The concept complies with the fundamental recommendations of DIN 72036, which will soon be published. ITW has already presented the concept with bonded fasteners to premium OEMs in the south of Germany and is working together with one of them on the concept approval. If these tests are successfully completed, cable set manufacturers could integrate the adhesive technology into their initial automated production concepts for this premium OEM. ITW can support partners with fasteners suitable for automation, setting head technology and its expertise on the entire production concept in this process.

The ITW locators have individual geometries, but can be processed with just one setting head.