أحتاج الى مصدر عن نظام منع الانغلاق (abs)

علي الخانقيني1

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بسم الله الرحمن الرحيـم
اللهم صل على محمد وآل محمد
السلام عليكم ورحمة الله وبركاته ...
أخوتي الاعزاء احتاج الى مصدر خاص عن نظام الفرامل abs
ويا ريت مصدر حديث و انكليزي ...
ودمتم في عافية ...

 

hooold

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أرجو أن يفيدك هذا الفيديو البسيط : ABS operation - YouTube

ورابطان يحتويان على كتابين عن هذا النظام:

http://www.google.ca/url?sa=t&rct=j&q=anti%20lock%20brake%20system%20abs.pdf&source=web&cd=3&cad=rja&sqi=2&ved=0CDIQFjAC&url=http%3A%2F%2Fwww.fmcsa.dot.gov%2Fdocuments%2Ffhwa-abs.pdf&ei=90uiUOz8GsjJhAeFxYDAAg&usg=AFQjCNGZhyVVJ8TX1E9nkLOVmoUCUeYjrQ]Redirect Notice


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طارق حسن محمد

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[FONT=&quot]اليك اخي العزيز نظام فرامل[/FONT][FONT=&quot](ABS )
عسى ان تستفاد منه وتقبل تحياتي

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[FONT=&quot]HOW ANTILOCK BRAKES WORKS[/FONT][FONT=&quot]
All antilock brake systems control tire slip by monitoring the relative deceleration rates of the wheels during braking. If one wheel starts to slow at a faster rate than the others, or at a faster rate than that which is programmed into the antilock control module, it indicates the wheel is starting to slip and is in danger of breaking traction and locking up. The ABS system responds by momentarily reducing hydraulic pressure to the brake on the affected wheel or wheels.
Electrically operated solenoid valves are used to hold, release and reapply hydraulic pressure to the brakes. This produces a pulsating effect, which can usually be felt in the brake pedal during hard braking. The driver may also hear a buzzing or chattering noise from the ABS hydraulic unit.
The rapid modulation of brake pressure in the brake circuit reduces the braking load on the slipping wheel and allows it to regain traction, thus preventing lockup. It is the same as pumping the brakes, except that the ABS system does it automatically for each brake circuit, and at speeds that would be humanly impossible, up to dozens of times per second depending on the system (some are faster than others).
Once the rate of deceleration for the affected wheel comes back in line with the others, normal braking function and pressure resume, and antilock reverts to a passive mode.



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[FONT=&quot]WHO MAKES ANTILOCK BRAKES?[/FONT][FONT=&quot]
The major OEM suppliers of antilock brakes are:
Bendix, Acquired from Allied Signal by Bosch, used primarily on Chrysler and Jeep products.
Bosch, Main supplier for most imports and assorted domestic vehicles.
Delco, Now known as Delphi, is used exclusively on GM applications.
Continental Teves, found on various Ford, GM, Chrysler and import applications.
Kelsey-Hayes, supplier of rear-wheel ABS and four-wheel ABS systems on Ford, Chevy and Dodge trucks.
Nippondenso, used on Infiniti and Lexus
Sumitomo, found on certain Mazda and Honda applications, as well as Ford Escort.
Toyota, rear wheel only ABS systems on Toyota pickups



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[FONT=&quot]ANTILOCK BRAKE CONFIGURATIONS[/FONT][FONT=&quot]
Regardless of who makes them, all ABS systems keep track of wheel deceleration rates with wheel speed sensors. On some applications, each wheel is equipped with its own speed sensor. This type of arrangement would be called a "four wheel, four channel" system since each wheel speed sensor would give its input into a separate control circuit (the word "channel" here actually refers to each individual electronic circuit rather than the individual hydraulic brake circuits).
On other applications, fewer sensors are used. Many four-wheel ABS systems have a separate wheel speed sensor for each front wheel but use a common speed sensor for both rear wheels. These are called "three channel" systems. The rear wheel speed sensor is mounted in either the differential or the transmission. The sensor reads the combined or average speed of both rear wheels. This type of setup saves the cost of an additional sensor and reduces the complexity of the system by allowing both rear wheels to be controlled simultaneously.
Another variation is the "single channel" rear-wheel only ABS system that is used on many rear-wheel drive pickups and vans. Fords version is called "Rear Antilock Brakes" (RABS) while GM and Chrysler call theirs "Rear Wheel Anti-Lock" (RWAL). The front wheels have no speed sensors and only a single speed sensor mounted in the differential or transmission is used for both rear wheels. Rear-wheel antilock systems are typically used on applications where vehicle loading can affect rear wheel traction, which is why it is used on pickup trucks and vans. Because the rear-wheel antilock systems have only a single channel, they are much less complex and costly than their three- and four-channel, four-wheel counterparts.




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[FONT=&quot]INTEGRAL & NONINTEGRAL ANTILOCK BRAKES SYSTEMS[/FONT][FONT=&quot]
Another difference in ABS systems is that some are "integral" and others are "nonintegral."
Integral systems, which are found mostly on older full-size passenger car applications, combine the master brake cylinder and ABS hydraulic modulator, pump and accumulator into one assembly. Integral systems do not have a vacuum booster for power assist and rely instead on pressure generated by the electric pump for this purpose. The accumulators in these systems can contain over 2700 psi. The accumulator must be depressurized prior to doing any type of brake repair work by pumping the brake pedal 40 times while the key is off.
Nonintegral ABS systems, which are sometimes refereed to as "add-on" systems, are used on most of the newer vehicles. Nonintegral ABS systems use a conventional master brake cylinder and vacuum power booster with a separate hydraulic modulator unit. Some also have an electric pump for ABS braking (to reapply pressure during the ABS hold-release-reapply cycle), but do not use the pumps for normal power assist.



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[FONT=&quot]WHEEL SPEED SENSORS[/FONT][FONT=&quot]
The wheel speed sensors (WSS) consist of a magnetic pickup and a toothed sensor ring (sometimes called a "tone" ring). The sensor(s) may be mounted in the steering knuckles, wheel hubs, brake backing plates, transmission tailshaft or differential housing. On some applications, the sensor is an integral part of the wheel bearing and hub assembly. The sensor ring(s) may be mounted on the axle hub behind the brake rotor, on the brake rotor itself, inside the brake drum, on the transmission tailshaft or inside the differential on the pinion shaft.
The wheel speed sensor pickup has a magnetic core surrounded by coil windings. As the wheel turns, teeth on the sensor ring move through the pickup magnetic field. This reverses the polarity of the magnetic field and induces an alternating current (AC) voltage in the pickup windings. The number of voltage pulses per second that are induced in the pickup changes in direct proportion to wheel speed. So as speed increases, the frequency and amplitude of the wheel speed sensor goes up.
The WSS signal is sent to the antilock brake control module, where the AC signal is converted into a digital signal and then processed. The control module then counts pulses to monitor changes in wheel speed.
On applications where the wheel speed sensor is not part of the hub or wheel bearing assembly, it can be replaced if defective. Sensor problems can be caused by an accumulation of debris on the end (they are magnetic), incorrect air gap or faults in the wiring or connectors. [/FONT]

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