EFFICIENT COMPONENT HANDLING AND DRIVING INNOVATION

Doubling the number of product variants with half the setup time – that’s the achievement specialized machine manufacturer Harrandt accomplished when redesigning its measuring, testing, and assembly lines. At the core of this innovative solution is the SuperTrak long-stator linear motor-based transport system from B&R.

Precision is Key

“At first glance, engine pistons appear completely round and quite robust,” said Samy Alain Song, Head of Innovation and Electronics at Feinwerktechnik Otto Harrandt GmbH, “but during assembly, they must be handled with extreme precision and care.”

Meeting these core requirements when designing the piston assembly line has become increasingly challenging as the pistons themselves continue to evolve. For example, in the quest to create more efficient engines, automakers have halved the thickness of the rings installed on pistons over the past decade. As piston rings become thinner and more difficult to handle, maintaining the stability of the 24/7 production process becomes a significant challenge. “Even the slightest deviation during assembly can lead to quality issues,” Song emphasized.

That’s why Harrandt’s experts have meticulously developed and continuously refined every step of the piston assembly and inspection process, from measuring pistons with micron-level precision to installing piston rings and pressing piston pins into place.

Samy Alain Song, Head of Innovation and Electronics, Harrandt:

“The SuperTrak-based system gives us the opportunity to transfer the process and automation knowledge we’ve gained in piston assembly to both existing and new markets.”

On traditional assembly lines, pistons are transported from station to station on conveyors driven by belts or chains. “These systems are the most cost-effective solution for large-scale production—they are stable and reliable,” Song explained. “For large batches, requiring a relatively high number of changeover parts for up to 30 piston variants and an average changeover time of around an hour and a half isn’t a significant issue. However, the cost analysis looks entirely different for production runs of just a few thousand units, which have become more common today.” These smaller production runs—partly driven by the shift to electric vehicles—demand more flexible manufacturing options with fewer changeover parts and shorter changeover times.

More Flexibility with the New Transport System

To better meet the needs of today’s users with shorter production runs, Harrandt developed an entirely new approach to its assembly lines. The first line completed under this new concept produces two-stroke pistons. It allows users to measure, inspect, and assemble 65 different types of pistons with a changeover time of only 20 to 30 minutes. Additionally, it significantly reduces the required floor space.

Harrandt’s assembly line is arranged around an oval-shaped track system, with the straight sections consisting of two one-meter-long segments each. Along these straight sections, Harrandt’s engineers have placed a total of ten stations.

On the two-meter straight sections at the front of the line, there are seven measurement and assembly stations. On the opposite side of the oval-shaped track system, Harrandt’s engineers placed a loading station, an unloading station, and a calibration station in the middle for 12 to a maximum of 16 transport shuttles. Thanks to the new transport system, Harrandt’s new lines occupy only half the space of previous lines with the same number of stations while achieving the same output, as the development manager proudly reported.

Keep the Best, Innovate the Rest

“For the new generation of assembly lines, we were able to use the measurement and assembly stations from our premium lines with virtually no changes. This means our customers can expect the same precision, stability, and 7-second cycle times as in our strongest previous lines. On the other hand, it has allowed us to focus on all the new possibilities that SuperTrak offers,” added Mr. Song.

Harrandt also retained the control system for the assembly processes, adding a B&R controller for the SuperTrak system. This control solution provides the high-speed data transfer that Harrandt needs for continuous monitoring and traceability of the 12 (or optionally 16) transport shuttles. The shuttles can also be moved to any position via software with repeatability of ±0.01 mm. As a result, pistons of varying sizes can be aligned so that the outline always stops in the same position.

Harrandt took advantage of this flexibility to develop a universal product holder for cylindrical or box-shaped products that can accommodate different piston sizes. This led to a significant reduction in the number of changeover parts and the time required for switching between variants.

SuperTrak also enables higher transport speeds, and slower processing steps can be distributed across multiple identical stations to maintain an overall faster cycle time. This is made possible because the shuttles can simply pass by unnecessary stations without stopping.

Flexible Expansion, Easy Maintenance

If additional processing stations are required, SuperTrak allows Harrandt to add them with ease. “On one hand, we can place more stations inside the oval and perform processing in the remaining space on the curved sections. Our internal analysis has confirmed that SuperTrak can meet our repeatability requirements at any point along the track, even on the curves,” Song pointed out. “On the other hand, expanding the system by adding straight sections is also relatively simple, with each segment accommodating two or three additional processing stations. With traditional lines, such expansion would only be possible at great cost and with a significant increase in floor space.”

Maintenance is also simplified with SuperTrak. Using a specialized tool, the transport shuttles can be easily removed and replaced for maintenance. Even track segments can be quickly detached and replaced, keeping maintenance downtime to a minimum.

Minimizing Investment Risk

During the development of the new line, Harrandt minimized risk in several ways. First, the flexibility in design achieved with SuperTrak, combined with the decision to retain proven hardware and software solutions in the processing stations, significantly reduced potential issues.

Additionally, the ability to simulate the movement of the track system provided Harrandt’s management with peace of mind from the planning stage. “The simulation helped us feel confident that we were on the right track technically. It reduced the risks associated with new technology, both for us and for our customers,” Song explained. Harrandt also plans to use the simulation function to demonstrate the system’s capabilities and performance to customers during the bidding phase for new lines.

It’s not just customers looking for efficient piston assembly lines who will benefit from Harrandt’s new approach. Harrandt’s new SuperTrak-based concept offers them the opportunity to apply all the process and automation knowledge they have gained in piston assembly to other markets as well.

Source: https://www.br-automation.com/en/news/blog/moving-workpieces-and-driving-innovation/