Drivetrain for Vehicles 2018 presentation of an innovation RoBoC = Roll Bond Core ADVANTAGES OFFER RoBoC - Keep the stator housing battery housing power unit housing junction box and other similar applications cool 1
Introduction of company AionaCast AionaCast Consulting GmbH is located in the South of Germany. Since 2010 AionaCast has been involved in all aspects of the aluminum castings business; it handles marketing, sales, development and also offers consulting, engineering and troubleshooting services. The company does not have an own production facility, we did set up collaborations with partners who own adequate production capacities in the required fields. 2
new manufacturing process for cooling channels Agenda E-engines All new e-engine housings for electric driven passenger cars and trucks are liquid cooled. Quelle: https://press.zf.com/site/press/de_de/microsites/press/list/release/media_18317.html; 2015-03-02_3_E-Maschine_Achsantrieb.jpg; ZF Friedrichshafen AG 3
importancy Agenda How to create cooling channels? The following procedures are used to create cooling channels for casted e-engine housings: Two-shell design (combination of high pressure die casting with another one or with continuous casting profile) Disadvantages: costs for additional CNC machining, sealing and assembly, risk of leakage, less stability of the inside part Shell casting with a lost core (sand, salt, glass, ceramic; shouted, pressed, cast or 3D-printed) Disadvantages: core removal, residual dirt, gas bubbles, machining and closing the core prints, with a cap, extended tests Inserted tubes, at times filled with salt Disadvantages: very limited in design Lost Foam Casting Process Disadvantages: costly, tolerances Laser powder deposition welding (3D-print) Disadvantages: just costly 4
Creating innovation The problem we would like to solve is: How to offer a production process for the cooling channels, which is at the same time easier, cheaper and of a higher quality? It should present the following features: No assembly process, just one casting for the housing, potentially including other features such as a gear box, etc. Suitable for high volume production -cheap- Low pressure drop Flexible layout of the cooling channels Thin cooling channels No corrosion issues Scalable in length and diameter 5
Our idea, which is already (PCT) patent pending We insert a light metal sheet package, which already includes all cooling channels and connectors, in a die for gravity or low pressure die casting and we recast it with aluminium. What makes this innovation really stand out, is the perfect combination of a standard casting process with the common rollbonding production method used for the light metal sheet package! Hence the innovation is named RoBoC. (Roll Bond Core) 6
Realization 1. Roll bond of 2 (aluminium-) sheets Heating of both sheets Apply a separating agent on the later inflated sections Roll bonding Pressurization with air to inflate the cooling channels Stamping (not used sections) Joining of the in- and outlet pipes 2. Forming the flat metal sheet to a cylinder 3. Inserting the light metal sheet package in the die 4. Closing of the die 5. Filling the die with molten metal and cooling of the RoBoC from inside during filling Avoiding fuse of the RoBoC 6. Solidification 7. Taking out the casting of the die 7
Design options Single Side Inflated with the help of different aluminium material grades Or Two Side Inflated Geometric tolerance is similar to the standard sand core process, only the tolerance in direction of the roll bonding is to be discussed The thickness of each sheet is approximately 0,35 to 0,6 mm Stable up to a test pressure of 20 bar 8
Implementation Present design of the inserted metal sheet 9
Implementation Example of a design for the inserted metal sheet 10
Result The result is a smooth embedded metal sheet with the shapes for the cooling channels integrated in the casting. 11
Implementation Present design of the inserted metal sheet 12
Implementation E-engine housing with connectors 13
Ø < 10 µm Agenda Result If requested, an additional coating of the metal sheet could prevent the gap formation between the RoBoC and the casting! without coating with coating aluminium sheet aluminium sheet casting alloy casting alloy 14
Cost advantages One piece of casting, no additional machinery or assembly process necessary ADVANTAGES Elimination of the highly complex sand core production necessity to remove the sand core machining and associated closing of the core prints Shorter cycle times for the casting process in reason of cooling from inside of the casting Elimination of the flow rate and leak pressure test after casting / assembly Less X-ray test Less casting scrap Potential cost reduction of up to 5 per unit 15
ADVANTAGES Additional advantages Design flexibility of the channels very flat channels are possible (2mm) different profiles for different value of heat exchange design of parallel channels is possible (less pressure drop) High stability of the housing, compared to a 2 shell design, Very smooth surface inside the channels Change of cooling channel layout is quite cheap Cooling of the channels during pouring and solidification of the molten metal, means better mechanical properties of the casting The process is also suitable for battery housings, power unit housings, junction boxes and other similar applications 16
Offer We can offer business cases: all rights of the patent pending licenses the casted and machined stator housing from a cooperation partner ADVANTAGES OFFER 17
Thank you for your attention! ADVANTAGES OFFER 18