Coating is one of the most complicated steps in the production process of ignition coils. Many believe it is also the most expensive. As a result, a large number of automotive suppliers hesitate to implement complex machinery to avoid procurement costs.
But there is an alternative to expensive custom-built systems, which has been around for some time now.
A cutting-edge economic solution for small to medium-sized automotive suppliers
In addition to its proven vacuum dispensing systems, Scheugenpflug AG offers bespoke equipment modules customised for ignition coil production.
The system is a standardised set of modules which can be combined into a repeat-accurate vacuum production system sizeable to suit any budget.
The production line modules are manufactured in volume production, which gives them a major advantage over custom systems.
The ideal process
A vehicle that starts rain or shine and takes us reliably to our destination? This is a matter of course for every car or lorry driver, whether air temperature is -40°C on ice and snow or 40°C on sandy roads with wind blowing. To master extreme conditions such as these is a quality standard for the automotive industry, which is a compulsory condition that ignition coil manufacturers must meet in all circumstances.
Even the tiniest inhomogeneity, bubble or cavity will result in a reject during production or in failure in the field. To guarantee maximum operability of an ignition coil dispensing must be done in a vacuum. However, it does not suffice to merely carry out the dispensing action in a vacuum. Ideally, the process starts with the proper preparation of the dispensing material.
Custom-built stirring mechanisms, tank degassing and material feed lines, pumps and valves sealed airtight are the minimum requirements to begin with. Dispensers in airtight design and a parametrised vacuum control round off the ultimate vacuum process. Most dispensing materials for potting ignition coils contain jagged fillers for better heat dissipation. Conventional machines suffer increased wear and tear, which raises costs for spare parts.
Therefore, we use low-wear spare parts instead of expensive ceramic seals and robust pumps and dispensers. When potting ignition coils it is essential to remove all air from the delicate coils of the component. To get rid of even the tiniest bubbles of air deep inside the coiled section of the part air pressure is lowered to about one millibar or less (absolute pressure) during the dispensing process. This is a much lower pressure than in conventional vacuum applications.
A standard system with modular design
In addition to the proven and compact-sized vacuum systems Scheugenpflug AG offers several production modules optimised for ignition coil encapsulation. Their material preparation units and vacuum chambers are equipped with more efficient pumps. Their double-walled hoses and lines (with a vacuum between the two tube walls) prevent air from diffusing into the dispensing material through the hose wall. Using these highly affordable accessories, every standard vacuum chamber becomes suitable for fine and high vacuum applications. Which means it can be used for filling ignition coils.
This modular plant design concept, which has already been implemented by many renowned automotive suppliers, uses standardised modules which can be flexibly combined with one another. Since these modules are manufactured in volume production, they show a major advantage over custom-built systems. Thanks to their universal interfaces they can be easily adapted to requirements and retrofitted or converted should the need arise due to newly emerging production requirements. If the system needs to be modified, the necessary module is added without having to discard existing machinery.
The controls are intuitive and their operation is easy to learn for handling personnel. This saves costs of training and familiarisation. It is an overall economic system which delivers output of highest repeat accuracy and superior process reliability, both in its semi-automated and its fully automated versions.
Scheugenpflug AG recommends consulting with a vacuum dispensing specialist from the planning stage of the system onwards. Many details, such as the design and shape of the substrate, upstream and downstream production processes, curing, etc. have considerable impact on the dispensing process. Therefore, professional analysis combined with mature processing technology and the correct choice of machinery can considerably lower investment costs and reduced project planning times.