KEY FACTORS IN THE PRODUCTION OF ENGINE BONNETS
The production of geometrically complex bonnets and ventilation grilles for agricultural and construction vehicles is a challenge in terms of manufacturing technology. This is mainly due to the difficult-to-predict behaviour of the filigree perforated sheet during the individual production steps.
In our interview, we asked the experienced process engineer Bence Osvald about the most important challenges in the production of bonnets and ventilation grilles. As team leader of application technology at the automotive technology supplier Solvaro, he is very familiar with the technical details of the manufacturing process and knows the stumbling blocks on the way to the perfect product. We asked him for an assessment of the critical points in the process.
Mr Osvald, why is it so important for you to be involved in the client’s projects at an early stage?
As soon as I get involved with a project, it is absolutely fundamental for me to know the exact requirements and wishes of the customer. If I don’t know why the customer designed the part in a certain way, I can’t make suggestions to improve it or avoid problems during production. It is not enough to see a 3D model or the technical drawing of a part. Because these don’t explain anything in terms of a particular stress or performance expectations. As a supplier, it is crucial for us to be involved in the early development phase. The effort is worthwhile: by taking advantage of the existing design leeway in this phase, we optimise the manufacturing process with foresight and minimise risks. As a result, we also reduce the resulting unit costs.
How do you eliminate possible complications in production in advance?
With method and a lot of experience. Knowing the behaviour of perforated metal in production is crucial for success. The only problem with this is that no one can exactly simulate the reaction of perforated metal. It is very different from the behaviour of unperforated metal. It is virtually impossible to calculate the mechanical stress, fracture behaviour or elongation. The only real guide that exists is experience. We also use a number of methods that eliminate any complications in advance. This makes the procedures and processes safe, stable and repeatable.
As a supplier, it is crucial for us to be involved in the early development phase.
Your personal hobbyhorse is the deep drawing of perforated parts. What is so complex about it?
Yes, I have been dealing with it for years and every project is a challenge, no matter how complex. Deep-drawing is difficult, deep-drawing perforated sheets more difficult and deep-drawing with semi-perforated sheets a special art. One issue that comes up again and again: the deformation of perforated areas after deep drawing. Every case is individual, every part is special and every material reacts differently. Based on years of experience, we now know how to set the decisive parameters, i.e. above all drawing radius and drawing speed, for complex components. For this purpose, we also use extensive tests in which we adapt the parameters individually to the customer’s requirements. So we are very practised in avoiding deformations or shifting them into the invisible range. So far, no case has remained unsolved. But the only guideline that exists is experience.
No other forming process offers such extensive design possibilities in production as deep drawing. With intuition and experience, we succeed in combining extraordinary customer requirements for function and weight of the component as well as the resulting air passage. Last but not least, the design also plays a decisive role.
Information on the expert
SOLVARO Kft, Project Leader and Application Engineering Specialist