BMW Car Parking assistance: two-component rotary table machine from ARBURG produces two million connectors per year
- Machinery & Equipment
When manoeuvring into tight parking spaces in their 7 Series BMWs equipped with the optional "Surround View" feature, motorists receive assistance from four digital cameras (icams). Eight-pin connectors featuring liquid silicone (LSR) seals for protection against spray water and dust are responsible for reliable connection between the cameras and electronic system.
H&B Electronic, based in Deckenpfronn, Germany, produces around two million of these icam connectors for Bosch each year on a two-component rotary table machine.
Additional eyes for parking
The cameras are installed in the exterior mirrors, front grille and tailgate, and show the surrounding area from a bird's eye view. The icam connectors provide the link to the central control unit. At the heart of the 8-pin connector, which features a positively bonded, moulded-on LSR seal, are four short and four long pins. During production, these are fed from stamping reels, automatically bent and inserted into a carrier component by a SCARA robot. The finished pre-assemblies are conveyed into the injection moulding cell on workpiece carriers.
H&B Electronic has extensive experience with delicate metal inserts and fully automated production processes. The icam connector is the first product with an LSR seal. H&B Electronic enlisted ARBURG's expertise and application technology consulting for its entry into liquid silicone injection moulding.
Two moulds – one ALLROUNDER
Stephan Schöne, responsible for project planning: "A combination of two injection moulding machines would have been significantly less expensive. However, the precise positioning of the pins is of the greatest importance for us. Here, we've had extensive and very good experiences with rotary table machines. Combining two moulds on a single ALLROUNDER also dispenses with coordination problems. We consequently opted for a two-component ALLROUNDER 1500 T rotary table machine with size 30 and 100 injection units for the LSR and PBT components respectively."
For the sprueless production of the pre-moulded part, H&B Electronic built a 4-cavity hot runner mould. Connectors for two different camera variants can be produced thanks to a changeover slide. "For moulding-on the LSR seal, we use a thermally self-sufficient cold runner mould," explains Stephan Schöne. The mixing and dosing technology is supplied by Reinhardt Technik and the automation solution was implemented jointly with partner fpt Robotik. The fully automated production cell is completed by a traverse handling system, three six-axis robots as well as two inspection stations and one tempering station."
|fig.: Stephan Schöne from Project Planning at H&B Electronic relies on a two-component rotary table machine for the production of icam connectors. These components for BMW park assistance systems are produced fully automatically|
Moulded-on rather than fitted seal
The precise positioning of four pre-assemblies in the mould is performed by a suspended six-axis robot. After overmoulding with PBT (GF 30), the pre-moulded parts are removed by a linear traverse handling system. The seal (LSR, Shore 40) is injected into the LSR mould from above in order to dispense with downstream assembly or bonding. While handling of the next pre-moulded parts is performed, the material has a few seconds' time to vulcanise. In order to ensure that the seal is intact and the pin positioning is correct, a camera test as well as one electrical and two mechanical tests are performed simultaneously at four inspection stations. Reject parts are sorted according to fault type and removed into drawers.
Following gentle heat treatment in a paternoster tempering furnace for eight hours, a pressure compensating element is finally applied and ultrasonically welded on by a further six-axis robot. Flow measurement, camera inspection and cleaning follow, before the icam connectors are packaged in 18-unit magazines and removed from the cell. Some two million icam connectors are produced each year in this manner. With expansion of the "Surround View" optional equipment to smaller vehicle series, this component promises great potential for the future.
Name: H&B Electronic GmbH & Co. KG
Location: Deckenpfronn, Germany
Divisions: In-house development, mould construction and 3D measuring lab, expertise in injection moulding, stamping and automated assembly
Production area: 13,500 square metres
Employees: 320, of which eight percent in Research and Development
Industries: Automotive, medical technology, control technology
Products: Complex connectors, hybrid components, precision-engineered modules
Machine fleet: 29 ALLROUNDERs (one and two components, LSR)
- ARBURG spol. s r.o.