Anybrid - which emerged from the Institute of Polymer Technology and Lightweight Construction at TU Dresden in December 2020 - develops mobile injection molding applications for various industries. It uses an industrial robot arm with a mobile injection molding machine installed at its head. Its clamping system is made from lightweight materials such as carbon. The machine called 'Robin' (robotized injection molding) flexibly performs plastic injection molding within a large movement radius. For this to work, the components used must be particularly light and flexible. The robot arm works with six axes, so cable routing was also a major challenge during the development of the mobile injection molding system.

Cable routing in injection molding applications is traditionally not very flexible and is geared precisely to the required task. Safe and reliable injection molding requires many different media, in addition to the power and data supply, these are primarily hydraulic and water lines. At Robin, there are four hydraulic circuits with eight hydraulic lines alone.

In the past, the lines were usually routed via simple corrugated hoses, which worked well in the laboratory environment, but is not suitable for the demands of industry. The main problem is operational safety: the hydraulic line is located in the corrugated tube hose directly next to the hot water hose, which in turn is located directly next to the power lines. Due to these high physical loads, the susceptibility to faults increases significantly. If the system is then installed in a highly flexible system such as a robot arm, defects are inevitable. The corrugated tube hose was therefore replaced by a three-dimensional energy chain from Igus. The 'triflex R' energy chain, which is particularly suitable for use in robotics applications, solves several problems at once. On the one hand, it enables cables to be routed in several structurally separate chambers. Secondly, the chain links allow a twist of ±10° per chain link in the longitudinal axis. Compared to conventional hoses, the energy chain has a defined bending radius, which significantly increases the service life of the cables and hoses it carries. A rubber band inside the energy chain acts as a retraction system, constantly pulling the chain links back to their starting point. Two different strengths can be set via the rubber band. For strain relief, Anybrid uses the 'CFX' clamps from Igus, which ensure a high holding force of pneumatic hoses in the energy chain.

Anybrid uses two different types of energy chain: on the lower axes, the cables are routed through the open chain 'triflex R TRLF.100', whose chain links are easy to open, lightweight and cost-effective. This variant is mainly used for thick and stiff hoses or when many cables are routed through the chain. The snap lock makes it easy to fill and replace pre-assembled cables at any time.

The author: Matthias Meyer is Head of the ECS triflex & Robotics division at Igus in Cologne.

© Igus

In axes 3 to 6, Anybrid uses the closed 'triflex' variant 'TRCF.100', which offers the separate chambers that are so important for the start-up and provides a high torsional capacity. This system can be easily extended and shortened, making it suitable for use along robot arms.