Energy and bus signals in a moving cable – but completely reliable!

Profile

• What was needed: chainflex hybrid cables, energy chains
• Requirements: Cables must be extremely flexible and guarantee a long service life and dependability with very small bend radii. 
• Industry: Machine tool manufacturing
• Success for the customer: Customised test programme for new cables specially designed to meet the customer's requirements and in particular to cope with the exceptionally low bend radii

The IMAGIC flex drilling centre has been developed for the order-related production of furniture, which reflects a highly flexible production.

Problem

60 metres per minute: This speed sets the pace for the drilling stations integrated into the IMA Klessmann GmbH rigs. They have to drill at high speed, even if the components are manufactured according to specific orders and have different drilling patterns.  The IMA Klessmann "Drilling Technology" business unit has developed the flexible IMAGIC flex drilling system for this application profile. The individually controllable drilling spindles enable horizontal and vertical drilling as well as dowelling, and promise minimum set-up times even for complex drilling patterns - and at a remarkably high speed.  The systems, which are planned specifically according to customer requirements, are equipped with up to 50 axes, which must be positioned and coordinated in seconds. In order to prepare the IMAGIC flex for this task, the designers had to "upgrade" the drive and control technology appropriately and decided to use the latest servo technology. The new one-cable technology combines the power and feedback system in the same servo cable. The single-cable technology saves material as well as costs and installation effort, since depending on the position of the control cabinet - which is specified by the customer - up to four kilometres of cables are laid. At the same time, however, this brought with it the challenge that a hybrid cable was required that could guarantee a long service life and dependability at the same time, given the high dynamics. Another complicating factor is the very small bend radii, because leading control technology companies had rejected the single-cable concept in the past. IMA took these concerns seriously, especially since the mobility of the hybrid cables was added as an extra factor.

Solution

And the first request to igus by no means dispelled the doubts. There was no guaranteed service life for the parameters under which the cables were to be used.
The was because of the small cable bend radii in the servo axes, which are sometimes up to 50 percent smaller than the target value indicated in the catalogue. But igus proposed a customised test program to IMA Klessmann. It would test the hybrid cables according to drive manufacturer specifications and the Hyperface DSL bus element at over four million strokes with the IMA-specific bend radii. Then they would be handed over to IMA for a practical test. After successful testing and application, there were no more obstacles to volume production.IMA ultimately decided on the PVC version of the chainflex hybrid cable. In high-speed applications in particular, most machine builders use cables with PUR jackets. But IMA has already had good experience with PVC in the past. For example, it uses PVC jackets for other cables as well. They have less abrasion and are very durable and fail-safe even in highly dynamic applications.
For guiding the cables, IMA Klessmann also looks to the igus range, using ready-to-install readychain systems. It uses open energy chains in which the wood dust cannot collect. This allows customers to use reliable systems from a single source for which components have been harmonised in decades-long development processes in the igus test laboratory.

Up to 50 servo axes are supplied with energy and signals via chainflex hybrid cables.

The axes are controlled by highly dynamic servo systems with one-cable technology.

Good guidance: energy chains, delivered as readychain products, undertake the orderly supply of energy and signals to the individual axes of the IMAGIC flex.

The chainflex hybrid cables are equipped with a built-in bus element and have been designed for a long service life in highly dynamic applications.