# رسالة الى د / محمد باشراحيل ::طلب بحث عن نظام التوجية و التعليق في السيارة



## راشد977 (10 ديسمبر 2009)

السلام عليكم و رحمة الله و بركاته :
بحث كثيرا عن بحث لنظام التوجية و التعليق في السيارة ولم اجدة و طالب مساعدتك الله يجزيك الف خير وطلبا منك وليس امرا عليك بتعجيل الرد في اليومين القادمة امدك الله بالصحة و العافية .


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## د.محمد باشراحيل (10 ديسمبر 2009)

راشد977 قال:


> السلام عليكم و رحمة الله و بركاته :
> بحثت كثيرا عن بحث لنظام التوجية و التعليق في السيارة ولم اجدة و طالب مساعدتك الله يجزيك الف خير وطلبا منك وليس امرا عليك بتعجيل الرد في اليومين القادمة امدك الله بالصحة و العافية .


 
وعليكم السلام ورحمة الله وبركاته 
أخي المهندس راشد 
أشكرك على ثقتك .. واسأل المولى ان أكون عند حسن ظن عباده بي..​ 
هناك موضوع بقسم السيارات هذا رابطه :​ 
مكونات الشاسيه:الفرامل،مجموعة التعليق ، مجموعة التوجيه ، الإطارات ‏​ 
وسوف اقوم بإقتباس موضوع من موقع Howstuffworks​ 
http://auto.howstuffworks.com/steering.htm​ 
ا- مجموعة التوجيه Steering System​ 
*How Car Steering Works*​ 
by Karim Nice​ 



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​ 
*Please copy/paste the following text to properly cite this HowStuffWorks article:*​ 
Nice, Karim. "How Car Steering Works." 31 May 2001. HowStuffWorks.com. <http://auto.howstuffworks.com/steering.htm> 09 December 2009.​ 

*Inside this Article*​ 



<LI sizset="57" sizcache="29">Introduction to How Car Steering Works <LI sizset="58" sizcache="29">Turning the Car
Rack-and-pinion Steering

<LI sizset="60" sizcache="29">Recirculating-ball Steering <LI sizset="61" sizcache="29">Power Steering <LI sizset="62" sizcache="29">The Future of Power Steering <LI class=articleTOCSeeMore sizset="81" sizcache="30" jQuery1260420292051="27">See more »
Lots More Information
See all Steering & Suspension articles

Junkyard Wars: Creating Steering Mechanisms




​ 



More Auto Videos »
 



​ 
There are several different types of car steering. See more car steering pictures.​ 


You know that when you turn the steering wheel in your car, the wheels turn. Cause and effect, right? But a lot of interesting stuff goes on between the steering wheel and the tires to make this happen.​ 



Up Next

<LI sizset="72" sizcache="29">*Car Suspension Quiz* <LI sizset="73" sizcache="29">*How Car Suspensions Work*
[URL="http://dsc.discovery.com/news/2008/04/04/space-rocket-shocks.html"]*Discovery.com: Rocket Shock Absorbers*[/URL]



­ In this article, we'll see how the two most common types of c­ar steering systems work: rack-and-pinion and recirculating-ball steering. Then we'll examine power steering and find out about some interesting future developments in steering systems, driven mostly by the need to increase the fuel efficiency of cars. But first, let's see what you have to do turn a car. It's not quite as simple as you might think!

­




​ 
When it comes to crucial automotive systems, steering is right up there with the engine and the brakes. The inner workings of this important component are pretty cool.​ 


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## د.محمد باشراحيل (10 ديسمبر 2009)

*Turning the Car*

You might be surprised to learn that when you turn your car, your front wheels are not pointing in the same direction. 

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For a car to turn smoothly, each wheel must follow a different circle. Since the inside wheel is following a circle with a smaller radius, it is actually making a tighter turn than the outside wheel. If you draw a line perpendicular to each wheel, the lines will intersect at the center point of the turn. The geometry of the steering linkage makes the inside wheel turn more than the outside wheel. 
There are a couple different types of steering gears. The most common are *rack-and-pinion* and *recirculating ball*. 


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## د.محمد باشراحيل (10 ديسمبر 2009)

*Rack-and-pinion Steering*

*Rack-and-pinion steering* is quickly becoming the most common type of steering on cars, small trucks and SUVs. It is actually a pretty simple mechanism. A rack-and-pinion gearset is enclosed in a metal tube, with each end of the rack protruding from the tube. A rod, called a *tie rod*, connects to each end of the rack








[SIZE=+1][/SIZE] 
[SIZE=+1][/SIZE] 
[SIZE=+1]Power Rack-and-pinion​When the rack-and-pinion is in a power-steering system, the rack has a slightly different design. 
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Part of the rack contains a cylinder with a piston in the middle. The piston is connected to the rack. There are two fluid ports, one on either side of the piston. Supplying higher-pressure fluid to one side of the piston forces the piston to move, which in turn moves the rack, providing the power assist. 
We'll check out the components that provide the high-pressure fluid, as well as decide which side of the rack to supply it to, later in the article. First, let's take a look at another type of steering

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## د.محمد باشراحيل (10 ديسمبر 2009)

*Recirculating-ball Steering*

*Recirculating-ball steering* is used on many trucks and SUVs today. The linkage that turns the wheels is slightly different than on a rack-and-pinion system. 
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The recirculating-ball steering gear contains a worm gear. You can image the gear in two parts. The first part is a block of metal with a threaded hole in it. This block has gear teeth cut into the outside of it, which engage a gear that moves the *pitman arm* (see diagram above). The steering wheel connects to a threaded rod, similar to a bolt, that sticks into the hole in the block. When the steering wheel turns, it turns the bolt. Instead of twisting further into the block the way a regular bolt would, this bolt is held fixed so that when it spins, it moves the block, which moves the gear that turns the wheels. 
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Instead of the bolt directly engaging the threads in the block, all of the threads are filled with ball bearings that recirculate through the gear as it turns. The balls actually serve two purposes: First, they reduce friction and wear in the gear; second, they reduce *slop* in the gear. Slop would be felt when you change the direction of the steering wheel -- without the balls in the steering gear, the teeth would come out of contact with each other for a moment, making the steering wheel feel loose. 
Power steering in a recirculating-ball system works similarly to a rack-and-pinion system. Assist is provided by supplying higher-pressure fluid to one side of the block. 
Now let's take a look at the other components that make up a power-steering system. 



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## د.محمد باشراحيل (10 ديسمبر 2009)

*Power Steering*

There are a couple of key components in *power steering* in addition to the rack-and-pinion or recirculating-ball mechanism. 

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[SIZE=+1]Pump[/SIZE]
The hydraulic power for the steering is provided by a *rotary-vane pump* (see diagram below). This pump is driven by the car's engine via a belt and pulley. It contains a set of retractable vanes that spin inside an oval chamber. 
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As the vanes spin, they pull hydraulic fluid from the return line at low pressure and force it into the outlet at high pressure. The amount of flow provided by the pump depends on the car's engine speed. The pump must be designed to provide adequate flow when the engine is idling. As a result, the pump moves much more fluid than necessary when the engine is running at faster speeds. 
The pump contains a pressure-relief valve to make sure that the pressure does not get too high, especially at high engine speeds when so much fluid is being pumped. 
[SIZE=+1]Rotary Valve[/SIZE]
A power-steering system should assist the driver only when he is exerting force on the steering wheel (such as when starting a turn). When the driver is not exerting force (such as when driving in a straight line), the system shouldn't provide any assist. The device that senses the force on the steering wheel is called the *rotary valve*. 
The key to the rotary valve is a *torsion bar*. The torsion bar is a thin rod of metal that twists when torque is applied to it. The top of the bar is connected to the steering wheel, and the bottom of the bar is connected to the pinion or worm gear (which turns the wheels), so the amount of torque in the torsion bar is equal to the amount of torque the driver is using to turn the wheels. The more torque the driver uses to turn the wheels, the more the bar twists. 
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The input from the steering shaft forms the inner part of a *spool-valve assembly*. It also connects to the top end of the *torsion bar*. The bottom of the torsion bar connects to the outer part of the spool valve. The torsion bar also turns the output of the steering gear, connecting to either the pinion gear or the worm gear depending on which type of steering the car has. 
As the bar twists, it rotates the inside of the spool valve relative to the outside. Since the inner part of the spool valve is also connected to the steering shaft (and therefore to the steering wheel), the amount of rotation between the inner and outer parts of the spool valve depends on how much torque the driver applies to the steering wheel. 

[FONT=arial,helvetica][SIZE=-1]*Animation showing what happens inside the rotary valve when you first start to turn the steering wheel*[/SIZE][/FONT] 
When the steering wheel is not being turned, both hydraulic lines provide the same amount of pressure to the steering gear. But if the spool valve is turned one way or the other, ports open up to provide high-pressure fluid to the appropriate line. It turns out that this type of power-steering system is pretty inefficient. Let's take a look at some advances we'll see in coming years that will help improve efficiency. 


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## د.محمد باشراحيل (10 ديسمبر 2009)

*The Future of Power Steering*

Take the Quiz​Do you know what steering systems are used in cars? Test your knowledge with this quiz from *Turbo*:
Car Steering Quiz​ 

Since the power-steering pump on most cars today runs constantly, pumping fluid all the time, it wastes horsepower. This wasted power translates into wasted fuel.
You can expect to see several innovations that will improve fuel economy. One of the coolest ideas on the drawing board is the "steer-by-wire" or "drive-by-wire" system. These systems would completely eliminate the mechanical connection between the steering wheel and the steering, replacing it with a purely electronic control system. Essentially, the steering wheel would work like the one you can buy for your home computer to play games. It would contain sensors that tell the car what the driver is doing with the wheel, and have some motors in it to provide the driver with feedback on what the car is doing. The output of these sensors would be used to control a motorized steering system. This would free up space in the engine compartment by eliminating the steering shaft. It would also reduce vibration inside the car. 
General Motors has introduced a concept car, the Hy-wire, that features this type of driving system. One of the most exciting things about the drive-by-wire system in the GM Hy-wire is that you can fine-tune vehicle handling without changing anything in the car's mechanical components -- all it takes to adjust the steering is some new computer software. In future drive-by-wire vehicles, you will most likely be able to configure the controls exactly to your liking by pressing a few buttons, just like you might adjust the seat position in a car today. It would also be possible in this sort of system to store distinct control preferences for each driver in the family. 
In the past fifty years, car steering systems haven't changed much. But in the next decade, we'll see advances in car steering that will result in more efficient cars and a more comfortable ride. 
For more information on steering systems and related topics, check out the links on the next page

*Lots More Information*



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[SIZE=+1]More Great Links[/SIZE] 

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ويتبع مجموعة التعليق​


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## د.محمد باشراحيل (10 ديسمبر 2009)

2- مجموعة التعليق Suspension System​

​وسوف اقوم بإقتباس موضوع من موقع Howstuffworks​ 

http://auto.howstuffworks.com/car-suspension.htm​ 
*How Car Suspensions Work*​ 
by William Harris​

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​ 
*Please copy/paste the following text to properly cite this HowStuffWorks article:*​ 
Harris, William. "How Car Suspensions Work." 11 May 2005. HowStuffWorks.com. <http://auto.howstuffworks.com/car-suspension.htm> 09 December 2009.​ 

*Inside this Article*​

<LI sizset="57" sizcache="29">Introduction to How Car Suspensions Work <LI sizset="58" sizcache="29">Car Suspension Parts
Dampers: Shock Absorbers

<LI sizset="60" sizcache="29">Dampers: Struts and Anti-sway Bars <LI sizset="61" sizcache="29">Suspension Types: Front <LI sizset="62" sizcache="29">Suspension Types: Rear <LI class=articleTOCSeeMore sizset="2" sizcache="39" jQuery1260420770899="27">See more »
<LI sizset="64" sizcache="29">Specialized Suspensions: The Baja Bug <LI sizset="65" sizcache="29">Specialized Suspensions: Formula One Racers <LI sizset="66" sizcache="29">Specialized Suspensions: Hot Rods <LI sizset="67" sizcache="29">The Bose Suspension System
Lots More Information
See all Steering & Suspension articles

Wrecks to Riches: Mock Up Engine



 

​

More Auto Videos »
When people think of automobile performance, they normally think of horsepower, torque and zero-to-60 acceleration. But all of the power generated by a piston engine is useless if the driver can't control the car. That's why automobile engineers turned their attention to the suspension system almost as soon as they had mastered the four-stroke internal combustion engine.​ 
*Car Suspension Image Gallery*​ 
­



Photo courtesy Honda Motor Co., Ltd.
Double-wishbone suspension on Honda Accord 2005 Coupe. See more car suspension pictures.​




The job of a car suspension is to maximize the friction between the tires and the road surface, to provide steering stability with good handling and to ensure the comfort of the passengers. In this article, we'll explore how car suspensions work, how they've evolved over the years and where the design of suspensions is headed in the future.​ 


Up Next

<LI sizset="79" sizcache="29">*Car Suspension Quiz* <LI sizset="80" sizcache="29">*How do stabilizer bars work?*
*Discovery.com: Shock Absorbers for Rockets*
If a road were perfectly flat, with no irregularities, suspensions wouldn't be necessary. But roads are far from flat. Even freshly paved highways have subtle imperfections that can interact with the wheels­ of a car. It's these imperfections that apply forces to the wheels. According to Newton's laws of motion, all forces have both magnitude and direction. A bump in the road causes the wheel to move up and down perpendicular to the road surface. The magnitude, of course, depends on whether the wheel is striking a giant bump or a tiny speck. Either way, the car wheel experiences a vertical acceleration as it passes over an imperfection. 



 


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Without an intervening structure, all of wheel's vertical energy is transferred to the frame, which moves in the same direction. In such a situation, the wheels can lose contact with the road completely. Then, under the downward force of gravity, the wheels can slam back into the road surface. What you need is a system that will absorb the energy of the vertically accelerated wheel, allowing the frame and body to ride undisturbed while the wheels follow bumps in the road.



The study of the forces at work on a moving car is called *vehicle dynamics*, and you need to understand some of these concepts in order to appreciate why a suspension is necessary in the first place. Most automobile engineers consider the dynamics of a moving car from two perspectives:

*Ride* - a car's ability to smooth out a bumpy road
*Handling* - a car's ability to safely accelerate, brake and corner
These two characteristics can be further described in three important principles - *road isolation*, *road holding* and *cornering*. The table below describes these principles and how engineers attempt to solve the challenges unique to each.


[SIZE=+1]Principle[/SIZE][SIZE=+1]Definition[/SIZE][SIZE=+1]Goal[/SIZE][SIZE=+1]Solution[/SIZE]*Road Isolation*[SIZE=-1]The vehicle's ability to absorb or isolate road shock from the passenger compartment[/SIZE][SIZE=-1]Allow the vehicle body to ride undisturbed while traveling over rough roads.[/SIZE][SIZE=-1]Absorb energy from road bumps and dissipate it without causing undue oscillation in the vehicle.[/SIZE]*Road Holding*[SIZE=-1]The degree to which a car maintains contact with the road surface in various types of directional changes and in a straight line (Example: The weight of a car will shift from the rear tires to the front tires during braking. Because the nose of the car dips toward the road, this type of motion is known as "dive." The opposite effect -- "squat" -- occurs during acceleration, which shifts the weight of the car from the front tires to the back.)[/SIZE][SIZE=-1]Keep the tires in contact with the ground, because it is the friction between the tires and the road that affects a vehicle's ability to steer, brake and accelerate.[/SIZE][SIZE=-1]Minimize the transfer of vehicle weight from side to side and front to back, as this transfer of weight reduces the tire's grip on the road.[/SIZE]*Cornering*[SIZE=-1]The ability of a vehicle to travel a curved path[/SIZE][SIZE=-1]Minimize body roll, which occurs as centrifugal force pushes outward on a car's center of gravity while cornering, raising one side of the vehicle and lowering the opposite side.[/SIZE][SIZE=-1]Transfer the weight of the car during cornering from the high side of the vehicle to the low side.[/SIZE]​

A car's suspension, with its various components, provides all of the solutions described.​ 
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## د.محمد باشراحيل (10 ديسمبر 2009)

*Car Suspension Parts*

­ The suspension of a car is actually part of the chassis, which comprises all of the imp­ortant systems located beneath the car's body. 
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[SIZE=-1]*Chassis*[/SIZE][/FONT]
These systems include: 

The *frame* - structural, load-carrying component that supports the car's engine and body, which are in turn supported by the suspension
The *suspension system* - setup that supports weight, absorbs and dampens shock and helps maintain tire contact
The *steering system* - mechanism that enables the driver to guide and direct the vehicle
The *tires and wheels* - components that make vehicle motion possible by way of grip and/or friction with the road
So the suspension is just one of the major systems in any vehicle. 
With this big-picture overview in mind, it's time to look at the three fundamental components of any suspension: springs, dampers and anti-sway bars. 
*Springs*
Today's springing systems are based on one of four basic designs: 

*Coil springs* - This is the most common type of spring and is, in essence, a heavy-duty torsion bar coiled around an axis. Coil springs compress and expand to absorb the motion of the wheels.
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[SIZE=-2]Photo courtesy Car Domain[/SIZE]
[SIZE=-1]*Coil springs*[/SIZE][/FONT]







[SIZE=-2]Photo courtesy HowStuffWorks Shopper[/SIZE]
[SIZE=-1]*Leaf spring*[/SIZE]
<LI sizset="75" sizcache="29">*Leaf springs* - This type of spring consists of several layers of metal (called "leaves") bound together to act as a single unit. Leaf springs were first used on horse-drawn carriages and were found on most American automobiles until 1985. They are still used today on most trucks and heavy-duty vehicles. 
*Torsion bars* - Torsion bars use the twisting properties of a steel bar to provide coil-spring-like performance. This is how they work: One end of a bar is anchored to the vehicle frame. The other end is attached to a wishbone, which acts like a lever that moves perpendicular to the torsion bar. When the wheel hits a bump, vertical motion is transferred to the wishbone and then, through the levering action, to the torsion bar. The torsion bar then twists along its axis to provide the spring force. European carmakers used this system extensively, as did Packard and Chrysler in the United States, through the 1950s and 1960s.
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[SIZE=-2]Photo courtesy HowStuffWorks Shopper[/SIZE]
[SIZE=-1]*Torsion bar*[/SIZE][/FONT]


*Air springs* - Air springs, which consist of a cylindrical chamber of air positioned between the wheel and the car's body, use the compressive qualities of air to absorb wheel vibrations. The concept is actually more than a century old and could be found on horse-drawn buggies. Air springs from this era were made from air-filled, leather diaphragms, much like a bellows; they were replaced with molded-rubber air springs in the 1930s.
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[SIZE=-2]Photo courtesy HSW Shopper[/SIZE]
[SIZE=-1]*Air springs*[/SIZE][/FONT]
Based on where springs are located on a car -- i.e., between the wheels and the frame -- engineers often find it convenient to talk about the *sprung mass* and the *unsprung mass*. 
*Springs: Sprung and Unsprung Mass*
The *sprung mass* is the mass of the vehicle supported on the springs, while the *unsprung mass* is loosely defined as the mass between the road and the suspension springs. The stiffness of the springs affects how the sprung mass responds while the car is being driven. Loosely sprung cars, such as luxury cars (think Lincoln Town Car), can swallow bumps and provide a super-smooth ride; however, such a car is prone to dive and squat during braking and acceleration and tends to experience body sway or roll during cornering. Tightly sprung cars, such as sports cars (think Mazda Miata), are less forgiving on bumpy roads, but they minimize body motion well, which means they can be driven aggressively, even around corners. 
So, while springs by themselves seem like simple devices, designing and implementing them on a car to balance passenger comfort with handling is a complex task. And to make matters more complex, springs alone can't provide a perfectly smooth ride. Why? Because springs are great at absorbing energy, but not so good at *dissipating* it. Other structures, known as *dampers*, are required to do this. 

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## د.محمد باشراحيل (10 ديسمبر 2009)

*Dampers: Shock Absorbers*

­ Unless a *dampening structure* is present, a car spring will extend and release the energy it absorbs from a bump at an uncontrolled rate. The spring­ will continue to bounce at its natural frequency until all of the energy originally put into it is used up. A suspension built on springs alone would make for an extremely bouncy ride and, depending on the terrain, an uncontrollable car. 
Enter the *shock absorber*, or snubber, a device that controls unwanted spring motion through a process known as *dampening*. Shock absorbers slow down and reduce the magnitude of vibratory motions by turning the kinetic energy of suspension movement into heat energy that can be dissipated through hydraulic fluid. To understand how this works, it's best to look inside a shock absorber to see its structure and function. 
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A shock absorber is basically an *oil pump* placed between the frame of the car and the wheels. The upper mount of the shock connects to the frame (i.e., the sprung weight), while the lower mount connects to the axle, near the wheel (i.e., the unsprung weight). In a *twin-tube design*, one of the most common types of shock absorbers, the upper mount is connected to a piston rod, which in turn is connected to a piston, which in turn sits in a tube filled with hydraulic fluid. The inner tube is known as the pressure tube, and the outer tube is known as the reserve tube. The reserve tube stores excess hydraulic fluid. 
When the car wheel encounters a bump in the road and causes the spring to coil and uncoil, the energy of the spring is transferred to the shock absorber through the upper mount, down through the piston rod and into the piston. Orifices perforate the piston and allow fluid to leak through as the piston moves up and down in the pressure tube. Because the orifices are relatively tiny, only a small amount of fluid, under great pressure, passes through. This slows down the piston, which in turn slows down the spring. 
Shock absorbers work in two cycles -- the *compression cycle* and the *extension cycle*. The compression cycle occurs as the piston moves downward, compressing the hydraulic fluid in the chamber below the piston. The extension cycle occurs as the piston moves toward the top of the pressure tube, compressing the fluid in the chamber above the piston. A typical car or light truck will have more resistance during its extension cycle than its compression cycle. With that in mind, the compression cycle controls the motion of the vehicle's unsprung weight, while extension controls the heavier, sprung weight. 
All modern shock absorbers are *velocity-sensitive* -- the faster the suspension moves, the more resistance the shock absorber provides. This enables shocks to adjust to road conditions and to control all of the unwanted motions that can occur in a moving vehicle, including bounce, sway, brake dive and acceleration squat. 

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## د.محمد باشراحيل (10 ديسمبر 2009)

*Dampers: Struts and Anti-sway Bars*

­A­nother common dampening structure is the *strut* -- basically a shock absorber mounted inside a coil spring. Struts perform two jobs: They provide a *dampening* function like shock absorbers, and they provide *structural support* for the vehicle suspension. That means struts deliver a bit more than shock absorbers, which don't support vehicle weight -- they only control the speed at which weight is transferred in a car, not the weight itself. 
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[SIZE=-1]*Common strut design*[/SIZE][/FONT]
Because shocks and struts have so much to do with the handling of a car, they can be considered critical safety features. Worn shocks and struts can allow excessive vehicle-weight transfer from side to side and front to back. This reduces the tire's ability to grip the road, as well as handling and braking performance. 
[SIZE=+1]Anti-sway Bars[/SIZE]
Anti-sway bars (also known as anti-roll bars) are used along with shock absorbers or struts to give a moving automobile additional stability. An anti-sway bar is a metal rod that spans the entire axle and effectively joins each side of the suspension together. 
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[SIZE=-2]Photo courtesy HSW Shopper[/SIZE]
[SIZE=-1]*Anti-sway bars*[/SIZE][/FONT]
When the suspension at one wheel moves up and down, the anti-sway bar transfers movement to the other wheel. This creates a more level ride and *reduces vehicle sway*. In particular, it combats the roll of a car on its suspension as it corners. For this reason, almost all cars today are fitted with anti-sway bars as standard equipment, although if they're not, kits make it easy to install the bars at any time. 

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## د.محمد باشراحيل (10 ديسمبر 2009)

*Suspension Types: Front*

­So far, ou­r discussions have focused on how springs and dampers function on any given wheel. But the four wheels of a car work together in two independent systems -- the two wheels connected by the front axle and the two wheels connected by the rear axle. That means that a car can and usually does have a different type of suspension on the front and back. Much is determined by whether a rigid axle binds the wheels or if the wheels are permitted to move independently. The former arrangement is known as a *dependent system*, while the latter arrangement is known as an *independent system*. In the following sections, we'll look at some of the common types of front and back suspensions typically used on mainstream cars. 
[SIZE=+1]Dependent Front Suspensions[/SIZE]
Dependent front suspensions have a rigid front axle that connects the front wheels. Basically, this looks like a solid bar under the front of the car, kept in place by leaf springs and shock absorbers. Common on trucks, dependent front suspensions haven't been used in mainstream cars for years. 
[SIZE=+1]Independent Front Suspensions[/SIZE]
In this setup, the front wheels are allowed to move independently. The *MacPherson strut*, developed by Earle S. MacPherson of General Motors in 1947, is the most widely used front suspension system, especially in cars of European origin. 
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[/FONT]
The MacPherson strut combines a shock absorber and a coil spring into a single unit. This provides a more compact and lighter suspension system that can be used for front-wheel drive vehicles. 
The *double-wishbone suspension*, also known as an A-arm suspension, is another common type of front independent suspension. 
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[SIZE=-2]Photo courtesy Honda Motor Co., Ltd.[/SIZE]
[SIZE=-1]*Double-wishbone suspension on Honda Accord 2005 Coupe*[/SIZE][/FONT]
While there are several different possible configurations, this design typically uses two wishbone-shaped arms to locate the wheel. Each wishbone, which has two mounting positions to the frame and one at the wheel, bears a shock absorber and a coil spring to absorb vibrations. Double-wishbone suspensions allow for more control over the camber angle of the wheel, which describes the degree to which the wheels tilt in and out. They also help minimize roll or sway and provide for a more consistent steering feel. Because of these characteristics, the double-wishbone suspension is common on the front wheels of larger cars. 
Now let's look at some common rear suspensions. 

يتبع


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## د.محمد باشراحيل (10 ديسمبر 2009)

*Suspension Types: Rear*





[SIZE=-2]Photo courtesy HowStuffWorks Shopper[/SIZE]
[SIZE=-1]*Leaf spring*[/SIZE]

[SIZE=+1]­Dependent Rear Suspensions[/SIZE]
­ If a solid­ axle connects the rear wheels of a car, then the suspension is usually quite simple -- based either on a leaf spring or a coil spring. In the former design, the leaf springs clamp d­irectly to the drive axle. The ends of the leaf springs attach directly to the frame, and the shock absorber is attached at the clamp that holds the spring to the axle. For many years, American car manufacturers preferred this design because of its simplicity. 
The same basic design can be achieved with coil springs replacing the leaves. In this case, the spring and shock absorber can be mounted as a single unit or as separate components. When they're separate, the springs can be much smaller, which reduces the amount of space the suspension takes up. 
[SIZE=+1]Independent Rear Suspensions[/SIZE]
If both the front and back suspensions are independent, then all of the wheels are mounted and sprung individually, resulting in what car advertisements tout as "four-wheel independent suspension." Any suspension that can be used on the front of the car can be used on the rear, and versions of the front independent systems described in the previous section can be found on the rear axles. Of course, in the rear of the car, the steering rack -- the assembly that includes the pinion gear wheel and enables the wheels to turn from side to side -- is absent. This means that rear independent suspensions can be simplified versions of front ones, although the basic principles remain the same. 
Next, we'll look at the suspensions of specialty cars. 
[SIZE=+1]Historical Suspensions[/SIZE][SIZE=-1]­Sixt­eenth-century wagons and carriages tried to solve the problem of "feeling every bump in the road" by slinging the carriage body from leather straps attached to four posts of a chassis that looked like an upturned table. Because the carriage body was suspended from the chassis, the system came to be known as a "suspension" -- a term still used today to describe the entire class of solutions. The slung-body suspension was not a true springing system, but it did enable the body and the wheels of the carriage to move independently. [/SIZE]
[SIZE=-1]Semi-elliptical spring designs, also known as cart springs, quickly replaced the leather-strap suspension. Popular on wagons, buggies and carriages, the semi-elliptical springs were often used on both the front and rear axles. They did, however, tend to allow forward and backward sway and had a high center of gravity. [/SIZE]
[SIZE=-1]By the time powered vehicles hit the road, other, more efficient springing systems were being developed to smooth out rides for passengers[/SIZE]


إنتـــــــــــــــــــــــــــــــــــهى


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## عاطف مخلوف (10 ديسمبر 2009)

بارك الله فيك دكتورنا العزيز 
موضوع يعد اثراء حقيقي للقسم فجزاك الله خيرا ، وزادك علما وفضلا.


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## اسامة القاسى (10 ديسمبر 2009)

جزاك الله خيرا كثيرا يادكتور محمد


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## د.محبس (10 ديسمبر 2009)

موضوع متكامل جدا

بارك الله فيك دكتورنا


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## سمير شربك (10 ديسمبر 2009)

واضيف الموضوع في الصفحة 1 للأخ الزائر mosbhy98
نظام التوجيه والتعليق

http://cdd.gotevot.edu.sa/college/mechanics/pdf/veh223.pdf
http://cdd.gotevot.edu.sa/college/mechanics/pdf/vehl223.pdf
كتب جيدة ومفيدة


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## راشد977 (11 ديسمبر 2009)

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وما قصرت د / محمد اتمنى من الله ان يديم عليك و على كل من يعز عيلك الصحة والعافية و العلم النافع
ومعليش اتعبتك معاية .


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## م.عبدالناصرعجوة (11 ديسمبر 2009)

بسم الله ماشاء الله عليك دكتورنا الفاضل دمت بخير


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## د.محمد باشراحيل (1 مارس 2010)

عاطف مخلوف قال:


> بارك الله فيك دكتورنا العزيز
> موضوع يعد اثراء حقيقي للقسم فجزاك الله خيرا ، وزادك علما وفضلا.


 
 أخي المهندس الفاضل عاطف مخلوف​


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## د.محمد باشراحيل (1 مارس 2010)

اسامة القاسى قال:


> جزاك الله خيرا كثيرا يادكتور محمد



بارك الله فيك مهندس أسامة​


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## د.محمد باشراحيل (1 مارس 2010)

د.محبس قال:


> موضوع متكامل جدا
> 
> بارك الله فيك دكتورنا



وبارك فيك د.محبس


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## د.محمد باشراحيل (1 مارس 2010)

سمير شربك قال:


> واضيف الموضوع في الصفحة 1 للأخ الزائر mosbhy98
> نظام التوجيه والتعليق
> 
> http://cdd.gotevot.edu.sa/college/mechanics/pdf/veh223.pdf
> ...


 

مشكور على الإضافة أخي المهندس سمير 




​


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## د.محمد باشراحيل (1 مارس 2010)

راشد977 قال:


> مشكوووووووووووووووووووووووووووور
> وما قصرت د / محمد اتمنى من الله ان يديم عليك و على كل من يعز عيلك الصحة والعافية و العلم النافع
> ومعليش اتعبتك معاية .


 
الأخ الكريم راشد977
 تقبل مني هذه الورود 






تقبل الله دعواتك وأثابك بمثلها 
وأدام علينا وعليك نعمه ظاهرة وباطنة.​


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## طارق حسن محمد (27 مارس 2010)

بارك الله فيك استاذنا العزيز على هذا المجهود الرائع0000000

لك مني كل احترام 00000000000


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## د.محمد باشراحيل (1 يوليو 2010)

للرفع.......................


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## د.محمد باشراحيل (1 يوليو 2010)

للرفع.......................


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## د.محمد باشراحيل (1 يوليو 2010)

للرفع..............


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