Beyond three years we are working with an automotive leader company in a project that concerns car’s rear-view mirrors.

The project foresees the production of millions of assemblies composed by a bonded plasto-neodymium magnet with an inner plastic insert (POM) gear shaped.

The complication is due to the strict specify and tight tolerances of the helix direction and helix angle of the plastic gear, aggravated by the small dimensions of the assembly.  The piece has indeed a diameter of 10 mm and total high of 17 mm.

First of all we have realized the magnetic part: a plasto-neodymium ring, D10*H8.5 mm, magnetized 16 poles on OD. This magnetization helps position sensor’s reading to control the angle of rear-view mirror opening/closure. Magnetic features correspond to grade BM-04 (Br 400-500 mT / Hcb 240-320 KA/m / Hcj 560-720 KA/m / (BH)max 32-44 MGOe). Maximum temperature resistance is 160 °C.

Successively we focused on plastic injection: a 17 mm high POM insert. The role of the POM is decrease inertia during piece rotation and make the motor lighter.

Compo Tech Co has realized today a pre-series of 20.000 unity already been homologated.

We are able to projects and produce customized magnets to satisfy every customer needs, also with special insert.

 

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