Verification of the effectivity, strength and operability of brakes
Service and parking brakes are safety-related devices used to reduce or limit speed or prevent the vehicle from moving uncontrolled. The braking process is mostly based on friction - the conversion of supplied (kinetic) energy into heat energy. The most common designs are the disc brake, drum brake and the block brake. Disc brakes, drum brakes and block brakes are often used for smaller transportation devices, such as bicycles, buggies, baby carriages, chairs, wheelchairs, walking frames and rollators.
In case of block brakes, the brake lining is radially pressed on the wheel tyre or the rim. Drum and disc brakes have a separate friction surface for axial pressure of the brake lining. In addition, magnetic brakes are used in which there is no contact between the brake and a mechanical actuator, so that only minimal wear occurs.
Regardless of the design of the braking principle, the method of transmitting the actuating force to the braking elements differs for pneumatically, hydraulically or cable-actuated brakes. Brakes are operated by pulling or pushing brake handles and levers (e.g. knee lever brake) by the user or an accompanying person.
Berlin Cert examination of brake systems
- Braking force: We determine the reduction of the braking efficiency by the influence of the environmental conditions (e.g. sunlight, dirt, humidity and ice) and wear.
- Structural stability and overheating: Thermal overload can cause deformation, melting and reduced braking effect. Long-term braking processes are therefore tested at different loads and with high braking forces. In addition, the effects of these effects on tires, bearings, hubs and lubricants are examined.
- Service life and dimensional stability of wearing parts
- Braking distances under different operating conditions (e.g. terrain) or wheel axis positions
- Ergonomic aspects of different mounting positions: Braking comfort (vibration, rubbing and squeaking), actuation forces, accessibility, clamping and squeezing
- Dynamic wheel load distribution: During the braking operation, the weight force is redistributed from the rear wheel to the front wheel, which reduces the static friction of the rear wheel and the stability of the entire system. The effects of wheel load distribution are amplified by a short wheelbase, steep inclination, road unevenness and a forward or upward shift of the center of gravity.
- Wheel lock: This effect is caused by the surface condition of the surface to be driven on and the braking force and can lead to a reduction in stability and steering ability. The inspection is carried out on different surfaces and inclinations of the road surface.
With isolated tests of brake systems based on selected configurations and with variable test parameters, definite & reliable statements can be obtained on product properties in a wide range of application scenarios.