An intelligent and highly flexible transport system enables a wide variety of production steps to be flexibly combined in a modular, powerful and versatile machine for the assembly of automotive fuel lines. Modularity and smart conveying offer a strategy that can be applied in multiple industries and applications.
“Fuel lines must be precisely adapted to the geometry of the respective vehicle model,” said Jörg Pfeiffer, a managing partner at Riester. “For this purpose, the fuel lines must be bent and provided with various connections, brackets, or fasteners.”
The challenge for Riester, an automotive and medical equipment original equipment maker based in Aspach, Germany, was to design a modular assembly machine that could produce many different fuel lines—as many as eight—at low cycle times without sacrificing product quality. Typically, multiple machines are necessary for different configurations. To support the auto industry’s requirements to lower equipment costs, conserve valuable floor space and increase flexibility, Riester decided to do something completely new. This led the company to contact Festo and Siemens, the developers of the multi-carrier system (MCS), a smart conveyor.
MCS carriers powered by linear motors are individually routed to the next designated assembly station. The carriers can be precisely positioned for greater accuracy in fuel-line assembly. Carriers can be accelerated and decelerated to synchronize with production, and carriers can be seamlessly shuffled into and out of a standard conveyor system. Using a mix of smart and standard conveying lowers cost.
While the bulk of transport in the new machine is via standard conveyor, MCS tracks route carriers to and from robot assemblers and machining stations. Rapid conversion of the machine is accomplished by automatically purging the previous MCS carrier type and introducing a new set of MSC carriers for the next fuel line to be assembled. At Riester, the MCS achieves changeover time up to five times faster than its previous solutions.
“Each fuel line requires its own specialized carrier for precise positioning,” Pfeiffer said. “And one machine is sufficient now because the changeover is simply the inflow of different MCS carriers and consequent change in software assembly recipe.”
Because robotic assemblers and machining stations are modular, Riester works on several in parallel to reduce total manufacturing time. Integrating the MCS was simply a matter of adding MSC tracks running to and from the stations. “If we want to create a new cable or geometry with this platform, we simply enter corresponding data into the human-machine interface, which includes new positions for the MCS carriers, and design new carriers,” Pfeiffer said. “There is no need to engage in complex modifications to the machine or the controller. This lets us quickly convert or adapt machines. If need be, we can add assembly modules and extend the MCS track.”
Pfeiffer sees modularity and smart conveying as a strategic capability.
“Modularity and smart conveying make it easy for Riester to develop new solutions that go beyond our previous business areas,” he said. “In principle, our assembly system can be used wherever components are individually assembled or handled from door handles up to individually manufactured medical products. With such new, strategic capabilities, you suddenly have many ideas—and also the possibilities to implement these ideas.”