ABS sensor is not the most important function in order to shorten the braking distance, but the direction to be able to keep the stability of an automobile during braking. When the ABS function, the wheels and the road surface friction is a rolling friction, it will make full use of the maximum adhesion between the wheel and the road braking, thereby improving brake acceleration, shorter braking distances, but the most important thing is to ensure the car stability direction. ABS work is equivalent to a high frequency snub. So, in case of emergency if the brake pedal in the end, will certainly feel the brake pedal vibrate, but also to hear the clatter issued a brake master cylinder, which is the ABS is working properly. A brake master cylinder pressure is continuously adjusted, thereby creating a continuous feedback force to the brake pedal.
1.ABS sensor types and principles
1, the annular wheel speed sensor is mainly composed of a permanent magnet, an induction coil and the ring gear and other components. Number of pairs of poles of the permanent magnet composition, the ring gear during rotation, alternating magnetic flux inside of the induction coil to generate an induced electromotive force, the signal input of the ABS electronic control unit via the cable end of the induction coil. When the rotational speed of the ring gear is changed, a sense ofIt should change the frequency of the electromotive force.
2, when a Hall sensor gear wheel rotational speed, so that the magnetic flux density passing through the Hall element varies, thus causing a change in the Hall voltage, the Hall element outputs a millivolt (mV) level the quasi-sine wave voltage. This signal is converted by the electronic circuitry needed to standard pulse voltage.
3, linear wheel speed sensor is mainly composed of a permanent magnet, the pole shaft, the induction coil and the ring gear and other components. When rotation of the ring gear, and the tooth top of the tooth gaps alternating polar axis. In the ring gear during rotation, alternating magnetic flux inside of the induction coil to generate an induced electromotive force, the signal input of the ABS electronic control unit via the cable end of the induction coil. When the rotational speed of the ring gear changes the frequency of the induced electromotive force also varies.
2. Installation and maintenance
1. When the ABS to the automotive assembly, only the brake hose designed.
2. When an ABS pressure of Never open the exhaust valve or loosen a hydraulic line.
3. When the ignition switch is turned on, never disconnect or connect any electrical connections to prevent damage to the ABS control means.
4. Do not knock the speed sensor means, speed loop must be pressed into the hub, not knocked into the inner hub. These components may be removed or cause demagnetization polarization returns to affect the accuracy of the speed signal ABS control device.
5. Do not confuse the tire size. As long as the tire remains close to the original diameter, increasing the width is acceptable. Scroll four tires must be the same diameter.
6. Failure to follow this precaution may cause inaccurate wheel speed readings.
7. A wheel lug nuts do not overtighten. Prevent bowing of the rotor or brake drum, which leads to inaccurate wheel speed readings.
8. Do not speed sensor member grease contamination. When the system requirements for anti-corrosion coating, the coating can only recommend. After
9. The rotational speed sensor member detached, must be checked when using the air gap sensor ring.
10. Use only the recommended brake fluid. Do not use silicon in the brake fluid car equipped with ABS. When
11. The communication device mounted on a car equipped with ABS, not the antenna apparatus installed in the vicinity of the ABS control.
12. When using the welding equipment, disconnect all of the onboard computer.
not the ABS control means 13. The prolonged exposure to high heat environments.
14. The air spring on a vehicle equipped with a suspension system, raising the total car To a suspension before switch off (OFF) position.
15. Before fitted with an auxiliary restraint system (SIR), i.e., the vehicle airbag, ABS or traction control for any system for processing should make the SIR system is inoperative, since to avoid accidental an air bag deployment cause injury or damage.