As early as 2024, Erwin Quarder Systemtechnik GmbH was commissioned by Volkswagen AG from Braunschweig with the development, including sample delivery, of an innovative solution for cooling control systems in electric vehicles. Internally, this project / the new cooling solution is simply referred to as the “VW Base Frame”.
Specifically, the plinth frame is a component of a component of the "HV heart" from the field of battery management. It serves as a carrier plate with integrated cooling for the electronic control units and plugs within VW's SSP platform (Scalable Systems Platform = modular vehicle platform for electric cars), which has been in planning since 2021. The SSP platform is intended to replace the current MEB (= Modular Electric Drive Toolkit) and PPE (= Premium Platform Electric – modular system for the "premium" segment of vehicle manufacturers) platforms for electric cars and is expected to be introduced from 2029. The main features of the SSP platform are a modular design of different vehicle types (e.g. sedans and SUVs) and a uniform powertrain (= the standardization of the powertrains, batteries and software for all electric cars of the VW Group). The SSP will also be prepared for future technologies (such as autonomous driving and advanced battery chemistry) and will also be made available to other automakers – so it will play a key role in future VW models and form the basis for the next generation of electric cars.
In this case, plastic injection moulding replaces the classic die-cast aluminium housing in the production of the base frame. The use of the injection moulding process offers an enormous weight advantage over aluminium and also eliminates the need for subsequent machining of the precise surfaces and the time-consuming friction stir welding of the cooling plates.
All functions are already integrated into the injection-molded component – only the aluminum cooling plates are joined using MPDB® technology, creating a helium-tight and long-term stable connection between plastic and metal. All cooling connections and screw-on points for the electrical components inside the "HV-Herz", as well as the circumferential screw-on points for screwing on the lid and pressing the seal of the lid, are already embedded in the injection-molded component. The cooling plates serve to cool the charging unit, connector contacts, and busbars. The component will later be located above the battery (1st Floor) and thus on the 2nd Floor of the “HV Heart”. Not only is the functional integration impressive, but also the realization of the imposing size of the functional carrier with integrated cooling, approximately 1,115.2 x 422 x 125 mm, in the injection molding process.
The injection moulded parts for the required sample parts are produced in China and in cooperation with a company that specialises in the development and manufacture of injection moulds and the production of injection moulded products of this size. Here in Espelkamp, the manufactured plastic parts are connected to the cooling plates using the MPDB® technology presented above, and their tightness is checked. In the final process step, the screw points are inserted into the prototypes and the cooling plates are contacted with potential equalization before the components are shipped to the customer. A dedicated area was newly created in development at Plant 4 for the assembly of prototypes to efficiently carry out all process steps.
Parallel to the production of prototypes, the base plate undergoes extensive internal tests to ensure quality based on customer requirements and to gain valuable experience for the next sample stage and series production. The knowledge gained will be immediately transferred to the next B3 sample phase by means of regular coordination rounds.
The first sample parts were already delivered in calendar week 20 and are being extensively checked and tested within the VW Group. Once the tests are successfully completed, the aforementioned B3 sample phase will begin, and series production will be within reach.
At the current time, the “HV Heart Base Frame” project looks very promising. We are all working together and keeping our fingers crossed that VW successfully implements the new SSP platform and that our component becomes an integral part of the cross-manufacturer modular principle.
