Profile

• What was needed: energy chains from the E4 product range, supplied as slim E4 light, as well as harnessed readychain; rotating energy supply with Reverse Bend Radius rotation module; chainflex cables
• Requirements: high stress with more than 8 million strokes per year, 24/7 operation and speeds of 4m/s (x-axis) or 3.5m/s (y-axis)
• Industry: automotive industry, press plant
• Success for the customer: chains and cables prove their worth with more than 23,000 strokes a day, tight bend radii and high speeds. Supplied as a harnessed readychain, the customer receives the system including cables and connectors in the correct length, crimped and screwed.

The combination of moving linear and rotary axes is the main reason for the special performance of the new feeder system (source: Strothmann).

Problem

With the "FeederPlus6 neo" from Strothmann, the press lines of automotive body construction can be automated. Within the forming process - from the sheet metal plate to the bonnet, to the door panel or to the complete side panel - it is the task of the feeder to pass the metal sheets from one station to the next. A complex sequence of movements is created in a four-second rhythm.
Compared to its predecessors, the FeederPlus6 neo sets new standards in service life and flexibility. This is due to the unique kinematics in which linear, rotary and telescoping movements are superimposed and precisely coordinated. Thanks to the telescope mechanism and the linear movements that are twice as fast as a result, the transfer unit can reach very far into the individual press stages within a few seconds. A total of five axes - three linear, one rotating and one telescopic - are electronically synchronised at each station, grip the plate and "thread" it into the next station.
The components that are particularly stressed during the complex movements include the energy chains for the power and signal supply up to the tool. A total of six energy chains were required here, whereby the cable guidance on the two main reverse rotary axes posed a major challenge.
First and foremost, these must allow a large number of strokes: a cycle rate of 16 strokes of the FeederPlus6 neo results in 23,040 strokes after just 24 hours, and over 8 million after a year. This requires maximum reliability and a robust construction, also because the presses are in 24/7 operation.
However, the speeds of 4m/s on the x-axis and 3.5m/s on the y-axis with acceleration values of up to 20m/s² must also be tolerated by the cable guidance.
These requirements also apply to the cables within the energy chains: with high loads, servo, bus, control, measuring system and grounding cables with a long service life should be found, for tight bend radii and many strokes.

Solution

In the FeederPlus6 neo, standard chains from the universally applicable E4 product range are used, some of them in the option E4 light, which takes up less installation space. A major challenge was the cable guidance on the two main reverse rotary axes. Reverse Bend Radius rotation modules for the rotary movements together with internal energy chains have proven themselves in this area today. chainflex cables, which were developed from the ground up for mobile applications, are guided in the energy chains. Strothmann prefers hybrid technology, in which the energy for the motor and the sensor signals are guided in one cable. We have a product range of cables that are extensively tested and approved for this system. For the FeederPlus6 neo, different cable types (servo cables, bus cables, control cables, measuring system cables and grounding cables) of the CF series with TPE jacket and the type CF280 hybrid servo cables are used. All cables prove their worth over the long term, even under adverse conditions, which are the case here because the plates are oiled. They are also characterised by small bend radii. Due to the extremely "slim" feeder system, these were also absolutely necessary. The moving cables cover a total length of 13 metres - distributed over five individual cables, each of which is supplied as a harnessed readychain. Strothmann uses this service mainly for reasons of process reliability. The customer receives professionally harnessed cables, crimped and screwed without tools and with a defined torque.
For a first prototype, the readychain systems were harnessed with connectors only on one side. After installing the energy chains, the exact cable length was measured and the cables were harnessed to fit perfectly. Strothmann initially tested this prototype for more than several 100,000 cycles. Only then was the FeederPlus6 neo released for sale. Since a service life of three years was agreed with Strothmann, the chains and cables have to achieve up to 24 million strokes. With this, we go well beyond our standard guarantee. Thanks to numerous operating parameters with datasets from our test laboratory, this is a guarantee that we can give with a clear conscience.

Extremely compact and very flexible: view of the FeederPlus6 neo with tooling.

Both the energy chains and the rotation modules were manufactured by us as a fully harnessed "readychain".