OUTLINE OF CONSTRUCTION The steering gear box is the same rack and pinion type used in the previous model,. 2. Two types of power steering control. Steering-System Good pdf - Free download as PDF File .pdf), Text File .txt) or read online for free. Firstly, the road curvature estimator is designed based on the steering angle, which has steering angle and its derivative as two state variables for which an.
|Language:||English, Indonesian, German|
|Genre:||Business & Career|
|ePub File Size:||26.39 MB|
|PDF File Size:||20.24 MB|
|Distribution:||Free* [*Registration needed]|
Wheel alignment. • At today's increased driving speeds, it most important to have swift and positive response from the steering system. • To accomplish this, the. Identify and understand the fundamental principles of steering system The steering system of a vehicle allows the driver to control the direction of the vehicle . All of the above situations force the driver to operate the vehicle at slow speeds, increasing steering effort causing FATIGUE TO DRIVERS. Judgment of a.
As the steering wheel rotates, so does the steering column, as well as the upper end of the torsion bar. Since the torsion bar is relatively thin and flexible, and the bottom end usually resists being rotated, the bar will twist by an amount proportional to the applied torque.
The difference in position between the opposite ends of the torsion bar controls a valve. This means that at high engine speeds the steering would naturally operate faster than at low engine speeds. A pressure relief valve prevents a dangerous build- up of pressure when the hydraulic cylinders piston reaches the end of its stroke. The steering booster is arranged so that should the booster fail, the steering will continue to work although the wheel will feel heavier.
Loss of power steering can significantly affect the handling of a vehicle. Common working liquids are based on mineral oil.
Steering-System Good pdf
Sensors detect the position and torque of the steering column, and a computer module applies assistive torque via the motor, which connects to either the steering gear or steering column. This allows varying amounts of assistance to be applied depending on driving conditions. Engineers can therefore tailor steering-gear response to variable-rate and variable damping suspension systems, optimizing ride, handling, and steering for each vehicle.
These give more assistance as the vehicle slows down, and less at faster speeds. A mechanical linkage between the steering wheel and the steering gear is retained in EPAS.
In the event of component failure or power failure that causes a failure to provide assistance, the mechanical linkage serves as a backup. When EPAS fails, the driver encounters a situation where heavy effort is required to steer.
This heavy effort is similar to that of an inoperative hydraulic steering assist system. Depending on the driving situation, driving skill and strength of the driver, steering assist loss may or may not lead to a crash.
The difficulty of steering with inoperative power steering is compounded by the choice of steering ratios in assisted steering gears vs. Electric systems have an advantage in fuel efficiency because there is no belt-driven hydraulic pump constantly running, whether assistance is required or not, and this is a major reason for their introduction. Another major advantage is the elimination of a belt-driven engine accessory, and several high-pressure hydraulic hoses between the hydraulic pump, mounted on the engine, and the steering gear, mounted on the chassis.
This greatly simplifies manufacturing and maintenance. By incorporating electronic stability control electric power steering systems can instantly vary torque assist levels to aid the driver in corrective maneuvers. The first electric power steering system appeared on the Suzuki Cervo in Today a number of manufacturers use electric power steering. In , Toyota introduced its second-generation MR2 with electro-hydraulic power steering.
This avoided running hydraulic lines from the engine which was behind the driver in the MR2 up to the steering rack. In Volkswagen produced the Mark 3 Golf Ecomatic, with an electric pump. This meant that the power steering would still operate while the engine was stopped by the computer to save fuel.
AGR has found the following method is the only proper way to bleed a system. Do not start the engine until system is fully bled. If on a Hydro Boost system, follow hydro boost bleeding procedures after bleeding the power steering system.
Vane Power Steering Pump: Vane pumps are the most common type of power steering pump used. In this type of pump the rotor is housed in an oval- or elliptical-shaped housing where it turns. Vanes fitted to the outside diameter of the rotor sit against the housing walls as the rotor turns.
When power steering fluid enters into the vane pump housing it is trapped between the vanes, the housing wall and the rotor. A subsequent pressure increase causes the fluid to be pumped out of the housing and then through the outlet chambers. Roller Power Steering Pump: In a roller power steering pump, wide V-shaped grooves cut into the side of the rotor allow steel rollers to ride along the inside contour of the pump.
The pump is contained in an oval- shaped housing within the pump body. Centrifugal force pushes the rollers to the oval's outer edge where they trap fluid, similar to the way the vanes catch the fluid in a vane pump. The pressurized fluid is forced out through two outlets in the pump, driving the power steering system.
Slipper Power Steering Pump: Just like the vane and roller pump, the slipper power steering pump has a rotor housed in an elliptical-shaped chamber that rotates within the body of the pump.
Fitted into wide slots on the rotor are springs that are topped with scrubber-type "slippers. As fluid enters into the pump, pressure is built up and released to drive the power steering system. Dedicated Steering Fluids: The chemical composition of dedicated power steering fluids varies by maker, but all will be marked as "Power Steering Fluids" and usually be composed of mineral oil, polyalphaolefin or organophosphate ester.
Transmission Fluids: Not all cars use dedicated power-steering fluid.
In this unit, the steering wheel is pivoted about a
Some systems use transmission fluid for hydraulic pressure in the steering system. The car's manual should specify which type of transmission fluid should be used in the power steering system. Manufacturer's Steering Fluids: Many manufacturers, including GM and Honda, make their own steering fluids. Although any kind of power steering fluid will usually work, performance is often optimized by using the manufacturer's label, which can be bought from any parts supplier for that make of car.
Interchangeable Steering Fluids: There are many brands of power steering fluid designed for use in all steering systems. Though they are not distinguished by type, their chemical compositions are different from manufacturer to manufacturer. Power steering system is highly accurate when compare to the normal steering mechanism. In normal steering mechanism steering will become hard because of the friction involved in the mechanical parts but in power steering mechanism most of the friction is reduced due to the fluid mechanics.
Fluid mechanics makes the steering effortless since no friction is involved. Power steering system is most reliable than the other steering mechanism. It has very smooth handling compare to other steering mechanisms.
They are, a. Power Steering Leak: The most common power steering problem that people are going to find is a leak in the system. This problem has a few different signs that will help you diagnose is pretty quickly. When you hear the grinding noise you are getting to the point where the fluid is very low and it must be fixed quickly.
If you run out of fluid, the pump can burn out completely. Drive Belt Slipping: Another very common problem that is associated with the power steering is when the belt in the pump will start to slip.
You will notice this very quickly when you hear a very loud squealing sound when you turn the steering wheel in a sharp turn. For example, when you come to a stop and must turn onto a new street, you will hear a squealing sound as you turn the wheel all the way in which ever direction you go.
Cracked Hoses: After several years of use, you will find that some of the hoses that are associated with the power steering can start to become dry and cracked. The only way to realize this before you start to have a leak is with a periodic inspection of the hoses and other components in your car's engine compartment. Hose is worn: Because of the close proximity to other parts in the engine bay, there is the chance that there will be contact with other parts as the vehicle is driven.
Steering-System Good pdf
This contact can begin to wear a hole in the side of a hose, or start to make the hose a little spongy on one side. After some time the pressure in the hose can cause it to burst while driving.
A sudden loss of pressure from the hose will cause your steering to get very hard quickly. Peeling Hose: Another problem associated with the power steering is found after it has been worked on. When the hose has been over crimped at one end, you will notice a little bit of peeling back on the hose.
When you take your care in to be serviced you should continue to check for leaks and any those problems like the hose peeling so you can take it back in. Coupling Creeps Off: If you have owned your vehicle for several years, and drive it a lot, one more problem that you can find is that the coupling on the hose will begin to creep off.
With a visual inspection of the power steering you will see this happening. Now a day we can see almost all cars having a power steering.
It provides good handling to the driver, gives better comfort and make him less fatigue. Popular Mechanics 5: ISSN Retrieved 8 November United States Patent and Trademark Office. Nunney, Malcolm James Elsevier Science. ISBN Retrieved 18 June You just clipped your first slide!
Steering-System Good pdf
Clipping is a handy way to collect important slides you want to go back to later. Now customize the name of a clipboard to store your clips. With the help of this system all the four wheels can be turned to any direction using the steering.
Thus the vehicle can be controlled more effectively especially during cornering and parking. Also the speed of the vehicle can be increased or decreased.
Four-Wheel Steering System
The mechanical 4WS uses two separate steering gears to control the front and rear wheels. The hydraulic 4WS uses a two-way hydraulic cylinder to turn both the wheels in the same direction. It is not possible to turn them in the opposite direction. This system finds application in off-highway vehicles such as fork lifts, agricultural and construction equipment and mining machinery. It is also useful in passenger cars, mainly SUVs. Four-wheel steering, 4WS, also called rear-wheel steering or all-wheel steering, provides a means to actively steer the rear wheels during turning maneuvers.
It should not be confused with four-wheel drive in which all four wheels of a vehicle are powered. It improves handling and help the vehicle make tighter turns.
Production-built cars tend to understeer or, in few instances, oversteer. The front wheels do most of the steering. Rear wheel turning is generally limited to during an opposite direction turn. During a same direction turn, rear wheel steering is limited to about When both the front and rear wheels steer toward the same direction, they are said to be in-phase and this produces a kind of sideways movement of the car at low speeds.
When the front and rear wheels are steered in opposite direction, this is called anti-phase, counter-phase or opposite-phase and it produces a sharper, tighter turn. To understand the advantages of four-wheel steering, it is wise to review the dynamics of typical steering maneuvers with a conventional front -steered vehicle.
The tires are subject to the forces of grip, momentum, and steering input when making a movement other than straight-ahead driving. These forces compete with each other during steering maneuvers. This causes the vehicle to sway. Each of these must be balanced against the others. The tires are subjected to road grip and slip angle.
Steering input causes the front wheels to turn. The car momentarily resists the turning motion, causing a tire slip angle to form.
Once the vehicle begins to respond to the steering input, cornering forces are generated. The vehicle sways as the rear wheels attempt to keep up with the cornering forces already generated by the front tires.
This is referred to as rear-end lag, because there is a time delay between steering input and vehicle reaction. When the front wheels are turned back to a straight -ahead position, the vehicle must again try to adjust by reversing the same forces developed by the turn.
As the steering is turned, the vehicle body sways as the rear wheels again try to keep up with the cornering forces generated by the front wheels.Similarly refer the above figure when the valve spool is moved towards right side then the direct return line from the pump to reservoir is closed.
Similarly refer the above figure when the valve spool is moved towards right side then the direct return line from the pump to reservoir is closed. The lower portion of the steering wheel hub fits into the upper flange of the steering column. For example, when you come to a stop and must turn onto a new street, you will hear a squealing sound as you turn the wheel all the way in which ever direction you go.
Coupling Creeps Off: