In addition to advances in batteries or continuous improvements in aerodynamics, electric cars of the not too distant future will also gain autonomy thanks to a new design of their brakes. The calls ‘Green Caliper’ (green caliper, translated into Spanish) are brakes developed by Continental significantly lighter and with which the autonomy of electric cars where they are mounted will be increased.
This is a new development from Continental, one of the most important suppliers to the industry worldwide, consisting of brake calipers (for disc brakes, of course). lighter than current and with a lower residual braking torque thanks to a less friction between the brake pad and the disc.
This new design of the caliper saves up to two kilograms on each brake caliper, plus another three kilograms per disc, since the disk is also much thin and light. In total, up to five kilos are saved per wheel, a diet that not only contributes to reducing consumption and increasing the range of an electric car, but also has an impact on better driving dynamics thanks to the reduction of unsprung masses. We all come out winning.
The other advantage has to do with the friction reduction. An advance that has been possible thanks to the fact that the development of the caliper has been specifically oriented to meet the requirements of a brake on an electric vehicle.
Unlike the brakes of a conventional vehicle, those of an electric car are activated much less frequently. In more than 80% of deceleration situations, an electric vehicle decelerates thanks to the energy recovery system (up to about 0.3 g of deceleration), so that the hydraulic brake is not necessary except in more intense braking or when braking. of emergency.
The transition zone between recovery braking and disc brakes is controlled by the electronic braking system, so the brakes only work beyond this point. Continental developers have designed a more compact caliper and smaller, thinner brake pads. At the same time, the smallest brake caliper with its lower height allows the installation of a brake disc with a larger diameter and, thanks to the reduction of the thermal load, much thinner, which saves more weight. By applying the same force to the caliper, greater deceleration power is achieved.
For the sake of efficiency, the ‘Green Gripper’ features a active brake pad retraction after each stop. This reduces the residual braking torque between the pads and the disc to less than 0.2 newtons, which means operation with virtually no frictional energy losses. Another design innovation ensures that the air gap between the pad and the disc is larger and is evenly distributed on both sides of the brake.
In combination with the brake-by-wire system and an electronic pedal, the longer pad travel (done this way to reduce residual torque) has no perceptible effect on the brake pedal for the driver. In this way, Continental ensures that with these clamps That “strange” touch on the brake pedal of electric cars and some plug-in hybrids ceases to exist in the transition zone between one braking system and another.
Continental ensures that this technology is now ready for production and the Green Caliper brake caliper will be able to be integrated into production vehicles with the usual development time of two to three years.