Installed as part of major production line upgrade, along with a Hofmann high speed inflating machine, the new system has reduced assembly and inflation time by a factor of ten, from around seventy to just seven seconds.
The bulk of Tyre-Line’s business is the supply of wheels for trailers and caravans. Managing director Edward Musson explains: “Until recently, our assembly process was largely semi-automated. This was relatively slow and inflexible, which made it difficult to handle different sizes of wheels and tyres; due to its age, it had also become increasingly unreliable. With demand growing for our products we recognised that we had to take a fresh approach, and contacted a number of potential suppliers, who we thought might be able to help us develop a suitable solution that matched our budget and specification, while future-proofing our business.
Musson adds that Autarky “went far further than simply building a system to our specification, as they worked with our production team to carry out a full design and needs assessment. As part of this process they developed solutions to potential problems that we’d not even considered; this completely changed our approach and resulted in a system that far surpassed our original criteria, in terms of performance, flexibility and future scalability.”
The Hofmann tyre inflation machine forms the heart of the new system. Capable of inflating each tyre in just seven seconds, the machine has infeed and outfeed conveyors, with the latter comprising two separate spurs: one for automotive wheels that need balancing and one for all other wheels.
Wheel rims and tyres are assembled and labelled with a unique bar code at the start of the infeed conveyor, with an extended track and additional loading and queuing zones leading up an inclined track to match the height of the tyre inflation machine.
Immediately prior to the inflation machine is a bar code reading station. This comprises an array of three camera units, with integrated lighting; these are positioned so that they can read barcode labels placed at any angle or position on the wheel rims. The information from each bar code is automatically transferred to the tyre inflation machine, to control the inflation pressure; it also allows a dimensional check to be carried out, confirming that the correct combination of tyre and wheel rim has been fitted.
Edward Musson points out: “Interconnecting the bar code reading station and tyre inflation machine allows us to run any rim and tyre configuration, in any combination, without the need for changing the system setup. This is a major boost to productivity and gives us the ability to run just a single wheel, or any batch size.”
The entire system has been designed to minimise the risk of damage to each assembly. For example, transfer units automatically align each assembly on the centre line of the conveyor, to prevent contact with side rollers, with all rollers being fitted with soft PVC sleeves. The downward-sloping outfeed unit features inertia braking to control the speed with which the finished assembly is presented to the operator, while loading points use specially developed plastic raise/lower beds to make it easier for operators to load and unload wheel assemblies. Additionally, each wheel assembly is automatically kept within an independent zone, to prevent contact between wheels in the event of backup before the inflation machine.
The solution developed by Autarky Automation uses 24V DC motorised drive rollers throughout, with Siemens PLC and HMI to control the conveyors, transfer units and barcode readers. Data is communicated to the Hofmann controller via a standard Profinet industrial network.
Edward Musson concludes: “The new system has revolutionised our business. It provides the foundation for long-term growth, giving us additional capacity for the immediate future and scalability as our needs change. For example, Autarky Automation has already designed-in scope to add further automation equipment. The new system also gives us traceability of every assembly, so we can improve quality control still further; and by reducing manual handling we have also benefited from improved operator safety, with the ability to redeploy skilled staff to other operations within the business.”