GERMANY: Continental saves 1.5kg per wheel with new caliper brake
Continental has developed a fixed-type caliper brake for medium-sized passenger cars that is estimated to save 1.5kg per wheel.
The new aluminium monobloc brake caliper features drawn brake pads and is, Continental claims, more robust in terms of brake squeal, previously a known problem with fixed calipers.
"We are helping vehicle manufacturers to further reduce the CO2emissions on new models," said Continental chassis & safety division hydraulic brake systems business unit head of development for wheel brakes, Dietrich Golz.
"At the same time, light-weight design must not be allowed to create problems in other areas. In order to prevent squeal on fixed-type caliper brakes, we have used our experience with fist-caliper brakes to come up with an innovative fixed-type caliper design."
The new fixed-type caliper is primarily designed for the front axle, but can also be scaled for the rear axle. Based on this concept, the company is also considering developing a solution for the high-performance segment.
Unlike the fist-caliper brake, the fixed-type caliper has brake cylinders on both sides of the brake disk. The new 4MF fixed-type caliper brake (four pistons in a monobloc fixed-caliper housing) therefore has four brake cylinders.
The brake caliper is rigid and does not have to transfer any reaction forces from the side with the brake cylinders to the opposite side of the disk. Fixed-type calipers can therefore be installed in the area around the solid bridge straddling the brake disk, but also at the sides of the caliper with reduced thickness.
The technical benefits of the fixed-type caliper include residual brake torque when the brake is not actuated: the gap between the brake pads and the surface of the brake disk - known as clearance - can be made smaller and more even with a fixed-type caliper.
The fixed-type caliper brake has always had an audible weakness - as its frame is rigid it cannot dampen any vibrations. Fixed-type calipers therefore tend to squeal when the brakes are applied.
In order to eliminate this side effect, Continental has used simultaneous engineering to transfer the characteristic shape of the drawn brake pads to the fixed-type caliper.
On the new brakes, the brake pads are not held in place by individual bolts with cushion deflection, but by a central retaining spring with integrated pin lock.
In conjunction with the shape of the pad backing plate designed to support the pad, this reduces the vibrational energy when braking, says Continental.