The braking system is one of the most important safety systems in the car. A conventional braking system, however, has its flaws. If you brake too hard, the wheels lock up and the car will skid. If that happens, it is impossible to steer and to control its direction, certainly if it starts to spin. The tendency to spin will increase hugely if only one side of the car is skidding due to a difference in friction, for instance if there's water or ice on the side of the road.
Locked wheels generate far less friction than a turning wheel, so locking your wheels will elongate the braking distance considerably. Wheels generate the most friction and the shortest braking distance at 10 to 15% slip. Still, you need to be an expert racing driver to keep your car exactly on that limit. Most drivers can't, but a computer controlled Anti-Lock system can.
The hart of an ABS system is the actuator. This is a pump, which decreases the brake pressure to a wheel caliper if the wheel locks up. Then it restores the pressure gently, carefully increasing the braking force to the point of maximum friction. The actuator is controlled by a computer. It reacts if it notices that a wheel locks up. This perception is based on a difference in wheel speed between the wheels and on the angular velocity loss of individual wheels.
For the ABS computer it is vital to have an accurate wheel speed reading. This signal comes from a wheel speed sensor and a toothed ring on the hub. A wheel speed sensor is a coil, wrapped around a magnet. Coils react to a changing magnetic field. When the teeth of the toothed ring pass by the coil, the proximity of a tooth changes the magnetic field, causing an electric pulse in the coil. The amount of teeth passing per second creates a frequency of pulses, so the frequency is a measure for the wheel speed.
ABS sensors or wheel speed sensors are high precision parts. The amount of windings on the coil, the strength of the magnets or the composition of the core are crucial to create the specific pulse strength to which the ABS computer is tuned. The quality of the copper wires, the moulding and the insulation as well as the quality of the electrical connectors are essential for the quality and reliability of the system. Needless to say, that is a key element for one of the most important safety systems.
Nipparts has developed a wide range of ABS-sensors for Japanese and Korean cars. Nipparts ABS sensors are made to OE specifications and offer OE matching quality, to insure a perfect fit, easy installation, optimum functionality and flawless reliability of the Anti-lock systems. You can find our range of ABS sensors in our free catalogue.
- Perfect fit
- Tuned to OE specs
- OE matching quality
- Wide range available for Asian cars