- This article is primarily about the suspension of four-wheeled vehicles (or more). For information on the suspension of two-wheeled vehicles, see Suspension (motorcycle), Fork motorcycle, bicycle suspension, and bicycle fork.
Suspension is a tire system, air tires, springs, shock absorbers and connections that connect the vehicle to its wheels and allow for the relative movement between the two. The suspension system should support both roadholding/handling and ride quality, as opposed to each other. Setting a suspension involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, since all road or ground forces acting on the vehicle do so through tire contact patches. The suspension also protects the vehicle itself and the cargo or luggage from damage and wear. Front and rear suspension car design may be different.
Video Suspension (vehicle)
History
The initial form of the suspension on an ox-drawn cart has a platform swing on an iron chain attached to the train wheel frame. This system remained the basis for all suspension systems until the turn of the 19th century, although the iron chains were replaced by the use of leather straps in the 17th century. There are no modern cars that use the 'suspension rope' system.
The car was originally developed as a vehicle pulled by a horse. However, horse-drawn vehicles have been designed for relatively slow speeds, and their suspensions are not suitable for higher speeds permitted by internal combustion engines.
The first applicable spring suspension requires a high level of metallurgical knowledge and skill, and is only possible with the advent of industrialization. Obadiah Elliott registered the first patent for a spring suspension vehicle; - Each wheel has two durable steel leaf springs on each side and the body of the carriage has been mounted directly to the spring that is fitted to the axle. Within a decade, most of Britain's horse-drawn carriages were fitted with springs; wooden springs in the case of a light one-horse vehicle to avoid taxes, and steel springs on larger vehicles. These are often made of low carbon steel and usually take the form of multiple leaf springs.
Leaf springs have existed since the beginning of Egypt. Ancient military engineers used leaf springs in the form of bows to light their siege engines, with little success at first. The use of leaf springs in catapults was then refined and made to work several years later. Springs are not only made of metal, sturdy tree branches can be used as springs, as with a bow. The horse-drawn carriage and Ford Model T use this system, and are still used today in larger vehicles, especially installed in the rear suspension.
It is the first modern suspension system and, along with advances in road construction, heralds the single greatest improvement in road transport until the emergence of cars. The British steel springs were unsuitable for use on American rugged roads at the time, so the Abbot-Downing Company of Concord, New Hampshire reintroduced the leather strap suspension, which gave the swinging motion rather than the ups and downs of the spring suspension.
In 1901 the Mors of Paris first installed the car with shock absorbers. With the advantage of a wet suspension system on its 'Mors Machine', Henri Fournier won the prestigious Paris-to-Berlin race on June 20, 1901. Fournier's superior time was 11 hours 46 minutes 10 seconds, while the best competitor was LÃÆ'Ã… © once Girardot in Panhard with a time of 12 hours 15 minutes 40 seconds.
Coil springs first appeared on a production vehicle in 1906 at Brush Runabout made by Brush Motor Company. Today, coil springs are used in most cars.
In 1920, Leyland Motors used torsion rods in a suspension system.
In 1922, independent front suspension was pioneered in Lancia Lambda and became more common in mass market cars than in 1932. Today most cars have independent suspension on all four wheels.
In 2002, a new passive suspension component was created by Malcolm C. Smith, inerter. It has the ability to increase the effective inertia of wheel suspension using gear wheels, but without adding significant mass. It was originally used in Formula 1 in secret but has since spread to other motorsport.
Maps Suspension (vehicle)
Difference between rear suspension and front suspension
Every four-wheel vehicle requires a suspension for the front wheel and rear suspension, but on these two-wheeled vehicles can be a very different configuration. For the front-wheel drive car, the rear suspension has several constraints and various beam axes and independent suspension are used. For the rear-wheel drive car, the rear suspension has many obstacles and the development of a more expensive but more costly suspension independent layout is difficult. The four-wheel drive often has a similar suspension for the front and rear wheels.
History
The Henry Ford model uses a torque tube to withstand this force, since the differential is attached to the chassis by lateral leaf springs and two narrow stems. The torque tube circles the actual driveshaft and exerts power to its ball connection at the extreme back of the transmission, which is attached to the engine. The same method was used by Buick in the late 1930s and by the 1948 mandarin tub, which used helical springs that could not take the thrust back and forth.
Encouragement Hotchkiss, created by Albert Hotchkiss, is the most popular rear suspension system used on American cars from the 1930s to the 1970s. The system uses longitudinal leaf springs that are mounted forward and behind the live pivot differential. These springs send torque to the frame. Despite being insulted by many European carmakers at the time, it was accepted by American car makers because it was not expensive to produce. In addition, the dynamic defect of this design is suppressed by heavy loads of US passenger vehicles prior to the adoption of the Company's Average Fuel Economy standard.
The other French invented the De Dion tube, which is sometimes called "semi-independent". Like a true independent rear suspension, it uses two universal or equivalent connections from the center of the differential to each wheel. But the wheels can not completely rise and fall independently of each other; they are bound by the yoke that surrounds the differential, below and behind it. This method is only slightly used in the United States, although there is no evidence to suggest that independent suspensions are more expensive and correct. Its use around the year 1900 may be due to poor quality of tires, which quickly run out. By eliminating many unsprung weights, such as independent rear suspension, it makes them last longer.
Current rear-wheel drive vehicles often use independent, multi-link suspensions that are complex enough to locate the rear wheels safely while providing decent ride quality.
Spring, wheel and roll
Spring rates
The spring level (or suspension level) is a component in adjusting the height of the vehicle or its location in the suspension handling. When the spring is compressed or stretched, the force it provides is proportional to the change in length. Spring spring rate or spring spring constant is a change in the force it provides, divided by spring deflection changes. Vehicles carrying heavy loads often have heavier springs to compensate for additional weights that otherwise would damage the vehicle to the bottom of the journey (stroke). Heavier springs are also used in performance applications where the loading conditions experienced are more extreme.
Springs that are too hard or too soft cause the suspension to be ineffective because they fail to isolate the vehicle properly from the road. Vehicles that typically experience heavier suspension loads typically have heavy or hard springs with spring levels approaching the upper limit for the weight of the vehicle. This allows the vehicle to work properly under heavy loads when control is limited by load inertia. Riding in an empty truck used to carry cargo can be uncomfortable for passengers because of the high rate of spring relative to the weight of the vehicle. The race car will also be described as having a heavy spring and also uncomfortable. However, even though we say both have heavy springs, the actual spring rate for a 2,000 pound (910 kg) race car and a 10,000-pound (4,500 kg) truck is very different. A luxury car, taxi, or passenger bus will be described as having a soft spring. Vehicles with worn or damaged springs rise lower to the ground which reduces the overall amount of compression available for suspension and increases the number of lean bodies. Vehicle performance can sometimes have spring speed requirements other than vehicle weight and load.
Spring level math
Spring rate is the ratio used to measure how hard the spring to compress or expand during spring deflection. The magnitude of the spring force increases as the deflection increases according to Hooke's Law. In brief, this can be expressed as
Where
- F is the spring style used
- k is the spring rate of the spring.
- x is the spring deflection from its equilibrium position (ie, when no force is applied to the spring)
The negative sign indicates the direction of force applied and the force given by the opposite spring. The spring rate is limited to narrow intervals by vehicle weight, vehicle load will carry, and to a lesser extent by suspension geometry and performance desire.
Spring rates typically have units of N/mm (or lbf/in). Example of a linear spring level is 500 lbf/in. For every inch of spring compressed, it gives 500 lbf. Non-linear spring rate is one that the relationship between spring compression and given force can not be adequately mounted to the linear model. For example, the first inlet gives a force of 500 lbf, the second gives an additional 550 lbf (with a total of 1050 lbf), the third gives 600 lbf (with a total of 1650 lbf). In contrast, 500 lbf/in linear springs compressed up to 3 inches will only use 1500 lbf.
Tingkat pegas dari pegas koil dapat dihitung dengan persamaan aljabar sederhana atau dapat diukur dalam mesin penguji pegas. Permanent pegas k dapat dihitung sebagai berikut:
where d is the diameter of the wire, G is the sliding modulus of the spring (for example, about 12,000,000 lbf/inÃ,² or 80 GPa for steel), N is the number of wraps and D is the diameter of the coil.
Wheel speed
Wheel speed is the effective spring rate when measured on wheels. This is not just a spring level gauge.
Wheel rate is usually equal to or much less than spring rate. Generally, the spring is mounted on the control arm, swing arm or some other rotating suspension member. Consider the example above where the spring rate is calculated to be 500 lbs/inch (87.5 N/mm), if you move the wheel 1 at (2.5 cm) (without moving the car), the spring is more than likely to compress a smaller amount. Let's assume the spring moves 0.75 in (19 mm), the ratio of the arm lever will be 0.75: 1. The wheel speed is calculated by taking the squared ratio (0,5625) times the spring rate, thus obtaining 281.25 lbs/inch (49 , 25 N/mm). The squaring ratio is because the ratio has two effects on the wheel rate. The ratio applies to the style and distance traveled.
Wheel speed on independent suspension is quite easy. However, special consideration should be taken with some non-independent suspension designs. Take the case of the straight axle. When viewed from front or back, the wheel rate can be measured by the above means. However, since the wheels are not independent, when viewed from the side below acceleration or braking, the pivot point is infinite (since both wheels have moved) and the spring is directly parallel to the wheel contact patch. The result is often that the effective wheel rate under cornering is different from what is under acceleration and braking. Variations in the speed of this wheel can be minimized by placing the spring as close to the wheel as possible.
Wheel speed is usually summed and compared to the emerging mass of a vehicle to create "driving speed" and the natural frequency of the corresponding suspension in transit (also referred to as "heave"). This can be useful in creating metrics for suspension stiffness and travel requirements for vehicles.
Roll rate
The ratio of the roll is analogous to the speed of the ride, but for the action that includes lateral acceleration, causing the mass of the vehicle to sprout to roll on its scroll axle. This is expressed as a torque per degree of rolled-up vehicle mass. This is influenced by factors including but not limited to the mass of vehicle sprung, track width, height of CG, spring and damper level, middle height of front and rear roll, anti-roll bar rigidity and pressure/tire construction. The vehicle roll rate can, and usually, differ from front to back, allowing for vehicle tuning capability for transient and steady state handling. The roll rate of the vehicle does not change the total amount of weight transfer on the vehicle, but it shifts the speed at which and the percentage of weight is transferred on a specific shaft to another shaft through the vehicle chassis. In general, the higher the roll speed on the vehicle axle, the faster and higher the weight transfer percentage on the shaft.
Play multiple percentages
The percentage of rolled pairs is a simplified method for describing the lateral load displacement distribution from front to back, and then handling the balance. This is the effective wheel speed, in rolls, of each vehicle axle as the ratio of the total roll rate of the vehicle. These are usually adjusted through the use of anti-roll bars, but can also be changed through the use of different springs.
Transfer weight
Heavy transfer during cornering, acceleration or braking are typically calculated per individual wheel and compared with static weights for the same wheel.
The total amount of weight transfer is only affected by four factors: the distance between the wheel center (wheelbase in the case of braking, or the width of the track in the case of cornering) the height of the center of gravity, the mass of the vehicle, and the amount of acceleration experienced.
The speed at which weight transfers occur as well as through the components transferred is complex and determined by many factors including but not limited to the height of the roll center, the spring and damper levels, the stiffness of the anti-roll bar and the kinematic design of the suspension link. In most conventional applications, when weight is transferred through elements that are deliberately suited like springs, silencers and anti-roll bars, weight transfers are said to be "elastic", while the weights transferred through a more rigid suspension link such as A-sleeve and toe linkage are said to be as "geometric".
Transfer weight without charge
Unsprung weight transfer is calculated on the weight of vehicle components not supported by springs. These include tires, wheels, brakes, spindles, half-weight control arm and other components. These components then (for calculation purposes) are assumed to be connected to vehicles with zero weighting emerging. They are then fed through the same dynamic load. The weight transfer for cornering in front will be equal to the total unsprung G-Force's front weight times the center of gravity of the front unsprung divided by the width of the front passage. The same goes for the back.
Move the weight transfer
The transfer of spring weight is the weight transferred only by the weight of the spring-mounted vehicle, not the total weight of the vehicle. Calculating this needs to know the weight of the emerging vehicle (total weight minus unsprung weight), center height of front and rear roll, and center of gravity emerging height (used to calculate arm length during rolls). Calculating the transfer of front and back weight will also require knowing the percentage of the spool coil.
The axis of the roll is the line through the center of the front and back windings so the vehicle rotates while cornering. The distance from this axis to the center popping up from the gravitational height is the arm's length during the roll. The total weight transfer is eyed equal to the time G-force whose eyebrows weigh the arm length when divided by the effective trajectory width. The forward-looking weight transfer is calculated by multiplying the roll several times the percentage of total weight transfer appears. The back is the total minus front transfers.
Jacking Troop
The jack power is the number of vertical force components experienced by the suspension link. The resultant force acts to lift the emerging mass if the center of the roll is above the ground, or compresses it if it is underground. In general, the higher the center of the roll, the more piracy power experienced.
Other properties
Travel
The trip is a measure of the distance from the bottom of the stroke of the suspension (such as when the vehicle in the jack and the wheels hang free) to the top of the suspension stroke (such as when the wheel of the vehicle can no longer make its way up towards the vehicle). Lowering or lifting the wheels can cause serious control problems or directly cause damage. "Bottoming" can be caused by suspension, tire, fender, etc. Run out of space to move or body or other components of the car that hit the road. Control problems caused by lifting the wheels lighter if the wheels lift up when the spring reaches the shape that is not lowered than if the trip is limited by the contact of the suspension member (See Triumph TR3B.) Many off-road vehicles, such as the desert racers, use a rope called " binder "to limit the suspension downward to a point within the safe boundary for connection and shock absorbers. This is necessary, because the truck is intended to travel in extremely rough terrain at high speed, and even into the air at times. Without something to limit travel, the suspension bus will take all the power when the suspension reaches "full droop", and can even cause the spring coils to get out of their "bucket" if they are held only with compression forces. The limiting cord is a simple string, often nylon of a predetermined length, which stops motion down at a predetermined point before the theoretical maximum journey is reached. The opposite of this is the "bump-stop", which protects the suspension and the vehicle (as well as its occupants) from "bottoming" the hardness of the suspension, caused when the obstruction (or hard landing) causes the suspension to run out of the journey upwards without fully absorbing energy from the stroke. Without bump-stops, the "bottoms out" vehicle will experience a very violent shock when the suspension contacts the bottom of the frame or body, which is transferred to the occupants and each connector and welds on the vehicle. Factory vehicles often come with plain rubber "nubs" to absorb the worst power, and isolate the shock. The desert racing vehicle, which must routinely absorb much higher impact strength, can be equipped with pneumatic or hydro-pneumatic pneumatics. This is basically a miniature shock absorbers attached to the vehicle at a location such that the suspension will contact the end of the piston when it approaches the upward travel limit. It absorbs much more effective impacts than a solid rubber lump-stop will, important because rubber lump-stop is considered the "last emergency" emergency insulator for the occasional deliberate underlying suspension; it's simply not enough to absorb repetitive and heavy bases like high-speed off-road vehicle encounters.
Damping
Damping is a motion control or oscillation, as seen with the use of hydraulic gates and valves in vehicle shock absorbers. It may also vary, either intentionally or unintentionally. Like spring level, optimal damping for convenience may be less than control.
Damping controls the speed of travel and vehicle suspension obstacles. Unreached cars will oscillate up and down. With the proper level of damping, the car will return to its normal state in a minimal amount of time. Most of the damping in modern vehicles can be controlled by increasing or decreasing resistance to fluid flow in shock absorber.
Control of the grip
See dependent and independent below. Camber changes due to wheel travel, body roll and deflection or compliance suspension system. In general, wear and brake tires are best on -1 to -2 ° c of the vertical. Depending on the tire and road surface, it may hold the best path with slightly different angles. Small changes in the camber, front and rear, can be used to adjust the handling. Some race cars are tuned with -2 to -7 Â ° camber depending on the desired type of handling and tire construction. Often, too many camber will result in decreased braking performance due to reduced contact patch size through excessive camber variation in suspension geometry. The amount of camber change in the lump is determined by the length of the front arm swing (FVSA) of the suspension geometry, or in other words, the tendency of the tire to camber inward when compressed in the bump.
Height of the center of the roll
High roll center is a product of suspension center height suspension and is a useful metric in analyzing the effects of weight transfer, body roll and stiffness distribution of roll forward to back. Conventionally, the distribution of the roll stiffness is adjusted to adjust the antiroll bars rather than the height of the roll center (since both tend to have the same effect on the popping masses), but the height of the center of the roll is significant when considering the amount of piracy power experienced.
Instant center
Due to the fact that wheel and tire movements are limited by a suspension link on the vehicle, the wheel wheel movement on the front display will record an imaginary arc in space with an "instantaneous" rotation center at a certain point along its path. An instant center for each wheel package can be found by following an imaginary line drawn through a suspension link to its intersection.
Component of the tire style vector point of the tire contact patch through the instant center. The larger this component, the less suspension movement will occur. Theoretically, if the result of the vertical load on the tire and the lateral force generated by it points directly to the instant center, the suspension link will not move. In this case, any weight transfer at the end of the vehicle will be geometric. This is the key information used in searching for power-based center reels as well.
In this case instant centers are more important for vehicle handling than kinematic reel centers only, where the ratio of geometric to elastic weight transfer is determined by the strength of the tires and their direction in relation to their position. instant center respectively.
Variations in suspension design
Anti-subs and anti-squat
Anti-diving and anti-squat are the percentages that indicate the extent of front dives under braking and rear squatting under acceleration. They can be considered as partners for braking and acceleration, due to the power of cornering cornering. The main reason for the difference is due to different design goals between the front and rear suspension, while the suspension is usually symmetrical between the left and right of the vehicle.
The method of determining anti-skid or anti-squat depends on whether the suspension relation reacts to the braking torque and acceleration. For example, with inner brakes and axle driven rear wheels, no suspension joints, but with outboard brakes and driveline swing-axis, they do so.
To determine the percentage of anti-dive front suspension braking for outboard brakes, it is first necessary to determine the angular tangent between the drawn line, in the side view, through the front tire fillings and the front center of the front suspension, and horizontally. In addition, the percentage of front-wheel braking efforts should be known. Then, multiply the tangent with the percentage of front wheel drive effort and divide by the ratio of the center of gravity to the wheelbase. A 50% value would mean that half of the weight transfer to the front wheels, during braking, is being sent through the front suspension linkage and half is being sent through the front suspension springs.
To brake in, the same procedure is followed but using the center of the wheel instead of the contact patch center.
Forward acceleration anti-squat is calculated in the same way and with the same relationship between percentage and weight transfer. The anti-squat value is 100% and more widely used in drag racing, but the value of 50% or less is common in cars that have to experience severe braking. Higher anti-squat values ​​generally cause wheel jumps during braking. It is important to note that, while a 100% value means that all weight transfers are made through a suspension relationship. However, this does not mean that the suspension is incapable of carrying additional loads (aerodynamics, cornering, etc.) during a braking or forward acceleration episode. In other words, there is no "binding" of the suspension to be implied.
Mode of flexibility and vibration of the suspension element
In some modern cars, the flexibility is primarily in rubber bushes, which are prone to decay over time. For high voltage suspension, such as off-road vehicles, polyurethane bushing is available, which offers longer lifespan under greater pressure. However, due to weight and cost considerations, the structure is not made more rigid than necessary. Some vehicles exhibit a destructive vibration that involves flexing the structural parts, such as when it accelerates while turning sharply. The flexibility of structures such as frames and suspension links can also contribute to the springs, especially to dampen high-frequency vibrations. The flexibility of the wire wheels contribute to their popularity in times when the car has a lighter suspension.
Load leveling
Cars can be heavily loaded with luggage, passengers, and trailers. This loading will cause the tail of the vehicle to sink down. Maintaining a stable chassis level is essential to achieve the proper handling for vehicles designed for it. The drivers that come can be blinded by the lights. The self-leveling suspension negates this by inflating the cylinder in suspension to lift the chassis higher.
Isolation from high-frequency shock
For most purposes, the weight of the suspension component is unimportant, but at high frequencies, caused by the roughness of the road surface, the part isolated by the rubber bushes acts as a multistage filter to suppress noise and vibration better than can be done only with tires and water springs. (The springs work mainly in the vertical direction.)
Different designs about how much space they take and where it is located. It is generally accepted that MacPherson struts is the most compact arrangement for front-engine vehicles, where inter-wheel spacing is required to place the engine.
Incoming brakes (which reduce unsprung weight) may be more avoided due to space considerations than costs.
Style distribution
Suspension suspension must conform to the frame design in geometry, strength, and stiffness.
Air resistance (drag)
Certain modern vehicles have high suspension that can be adjusted to improve aerodynamics and fuel efficiency. Modern formula cars that have wheels and open suspensions usually use a sleeker pipe than simple round tubes for their suspension arms to reduce aerodynamic obstacles. Also common is the use of rocker arm suspension, push rod, or pull rod type which, among other things, puts the spring/damper unit into and out of the airflow to further reduce air resistance.
Cost
Production methods are increasing, but cost is always a factor. The continuous use of a sturdy rear axle, with unsprung differentials, especially in heavy vehicles, seems to be the most obvious example.
Springs and dampers
Most conventional suspensions use passive springs to absorb collisions and dampers (or shock absorbers) to control spring movement.
Some notable exceptions are the hydropneumatic system, which can be treated as an integral unit of spring and damping components used by the French manufacturer CitroÃÆ'¡n and the hydraulics, hydragas and cone systems used by the British Motor Corporation, especially on the Mini. A number of different types of each have been used: Passive suspension
Passive suspension
Springs and traditional silencers are referred to as passive suspensions - most vehicles are suspended in this way.
Spring
The majority of land vehicles are hung by steel springs, of these types:
- Spring leaves - AKA Hotchkiss, Cart, or semi-elliptical spring
- Torque torque suspension
- Spindle spring
Automakers are aware of the limitations inherent in steel springs, that they tend to produce unwanted oscillations, and have developed other types of suspension materials and mechanisms in an effort to improve performance:
- Rubber bushing
- Gas under pressure - air springs
- Gas and hydraulic fluids under pressure - hydropneumatic suspension and oleo strut
Silencer or shock absorber
Shock absorbers muffle movement (if not simple harmonic) vehicle up and down in its spring. They also have to wet most of the wheels when the weight of the wheel, hub, shaft, and sometimes brakes and differential breaks and ups and downs when a tire occurs. Some people say that the usual bulge is found on a dirt road (dubbed "corduroy", but really wrinkles or washing) caused by this wheel bouncing, though some evidence exists that is not associated with suspension at all. (See washboarding.)
Suspension semi-active and active
If the suspension is externally controlled then it is a semi active or active suspension - the suspension reacts to the signal from the electronic controller.
For example, Citroën CitroÃÆ'® n will "know" how far off the ground the car should be and constantly rearrange to reach that level, regardless of the load. This will not directly compensate for the roll body due to cornering. CitroÃÆ''n system adds about 1% car cost versus passive steel springs.
The semi-active suspension includes devices such as air spring and switchable shock absorbers, various self-leveling solutions, as well as systems such as hydropneumatic, hydrolastic, and hydragas suspension. Toyota introduced switchable shock absorbers at Soarer 1983. Delphi currently sells shock absorbers filled with magneto-rheological fluid, whose viscosity can be electromagnetically altered, thus providing variable control without changing valves, which is faster and thus more effective.
The fully active suspension system uses electronic monitoring of vehicle conditions, coupled with the means to change the vehicle suspension behavior in real time to control the car's movements directly. Lotus Cars developed several prototypes, from 1982 onwards, and introduced them to F1, where they were quite effective, but have now been banned. Nissan introduced low-bandwidth active suspension around 1990 as an option that adds an additional 20% to the price of luxury models. CitroÃÆ'¡n has also developed several active suspension models (see hydration). The recently published fully active system of Bose Corporation uses linear electric motors (ie, solenoids) in lieu of hydraulic or pneumatic actuators which have been used up to now. Mercedes introduced an active suspension system called Active Body Control on the Mercedes-Benz CL-Class in 1999.
Several electromagnetic suspensions have also been developed for vehicles. Examples include Bose electromagnetic suspension, and electromagnetic suspension developed by prof. Laurentiu Encica. In addition, the new Michelin wheels with embedded suspensions that work on electric motors are similar.
With the help of the control system, various semi-active/active suspensions embody improved design compromises between different vibration modes of the vehicle, ie bounce, roll, pitch and warp modes. However, the applications of this advanced suspension are limited by cost, packaging, weight, reliability, and/or other challenges.
The interconnected suspension
The interconnected suspension, unlike the semi-active/active suspension, can easily separate the different modes of vehicle vibration in a passive way. Interconnects can be realized in various ways, such as mechanical, hydraulic and pneumatic. Anti-roll bars are one typical example of mechanical interconnection, while it has been stated that fluorescent interconnects offer greater potential and flexibility in improving stiffness and damping properties.
Considering the considerable commercial potential of hydro-pneumatic technology (Corolla, 1996), interconnected hydropneumatic suspensions have also been explored in recent studies, and their potential benefits in improving travel and vehicle handling have been demonstrated. Control systems can also be used to improve interconnection suspension performance. Regardless of academic research, the Australian company Kinetic has some successes (WRC: 3 Championships, Dakar Rally: 2 Championships, Lexus GX470 2004 4ÃÆ' â € "4 years with KDSS, PACE award 2005) with various passive or semi-active systems, which generally separates at least two vehicle modes (roll, warp (articulate), pitch and/or heave (bounce)) to simultaneously control the stiffness and attenuation of each mode, using interconnected shock absorbers, and other methods. In 1999, Kinetic was bought by Tenneco. Later developments by the Catalan company, Creuat had designed a simpler system design based on a single working cylinder. After several projects on the competition, Creuat is active in providing retrofit systems for several vehicle models.
Historically, the first mass-production car with front-to-back mechanical interconnection suspension was 1948 CitroÃÆ'¡n 2CV. The 2CV suspension is very soft - the elongated joint makes the pitch softer than making a rigid roll. It relies on antidive geometry â € <â € British Motor Corporation is also an early adopter of interconnected suspensions. The system, dubbed Hydrolastic, was introduced in 1962 in Morris 1100 and later used on various BMC models. Hydraulics were developed by the suspension engineer Alex Moulton and used conical rubber as a spring medium (first used in 1959 Mini) with suspension units on each side connected to each other by fluid-filled pipes. The fluid transmits the power of the protruding path from one wheel to the other (on the same principle as the Citroen 2CV mechanical system described above) and since each suspension unit contains a valve to limit fluid flow also functions as a shock absorber. Moulton went on to develop a Hydrolastic replacement for the successor of BMC, Leyland UK. The system is manufactured under license by Dunlop in Coventry, called Hydragas working on the same principle but instead of a rubber spring unit it uses a metal ball split internally by a rubber diaphragm. The upper half contains the pressurized gas and the lower half of the same liquid as used in the Hydraulics system. The suspended transmitted fluid forces between the units on each side while the gas acts as a spring medium through the diaphragm. This is the same principle as the Citroen hydropneumatic system and provides similar but standalone driving qualities and does not require machine-driven pumps to provide hydraulic pressure. The downside is Hydragas, unlike the Citroen system, it can not be set altitude or self-leveling. Hydragas was introduced in 1973 at Austin Allegro and was used on several models, the last car to use it became MG F in 2002. The system was changed for the sake of more damp coil springs, due to cost reasons, towards the end of vehicle life. When it was disabled in 2006, Hydragas's manufacturing line is over 40 years old. Some of the latest postwar War Packard models also feature inter-related suspensions.
Suspension geometry
The suspension system can be broadly classified into two subgroups: dependent and independent. These terms refer to the opposite wheel's ability to move independently of one another.
Suspension dependent usually has a beam (simple cart shaft) or live axle driven that holds the wheel parallel to each other and is perpendicular to the wheel axle. When the camber of one wheel changes, the camber of the opposite wheel changes in the same way (with convention on one side this is a positive change in the camber and on the other hand this is a negative change). De Dion suspensions are also in this category because they connect the wheels rigidly.
An independent suspension allows the wheel to rise and fall by itself without affecting the opposing wheel. Suspensions with other devices, such as sway bars that connect the wheels in a certain way are still classified as independent.
The third type is a semi-dependent suspension. In this case, the motion of one wheel does affect other positions but is not attached to each other rigidly. The twist-beam rear suspension is such a system.
Suspend delay
The dependent system can be distinguished by the relationship system used to locate them, both longitudinally and transversely. Often these two functions are combined in a set of relationships.
Examples of location relationships include:
- Satchell Link
- Panhard rod
- Watt relevance
- WOBLink
- Mumford Relationships
- Leaf spring used for location (transverse or elongated)
- A fully elliptical spring usually requires additional location links and is no longer in general use
- The semi-elliptical longitudinal spring is used for public and is still used in heavy duty trucks and aircraft. They have the advantage that spring levels can easily be made progressive (non-linear).
- A single transverse spring for the front wheel and/or both rear wheels, supporting solid axles, used by Ford Motor Company, before and immediately after World War II, even on expensive models. It has the advantages of simplicity and low unsprung weight (compared to other solid shaft designs).
On the front engine, the rear drive vehicle, the dependent rear suspension is the "live axis" or the deDion shaft, depending on whether the differential is run on the shaft or not. The living axis is simpler but the weight of the unsprung contributes to the wheel bouncing.
Because it ensures a constant camber, suspended (and semi-independent) suspension is most common in vehicles that need to carry large loads as a proportion of vehicle weight, which has relatively soft springs and which are not (due to cost and simplicity) active suspension. The use of a dependent front suspension has become limited to heavier commercial vehicles.
Independent suspension
The diversity of independent systems is greater and includes:
- Swing axle
- Shear Pillar
- MacPherson strut/Chapman strut
- A-upper and lower arm (double wishbone)
- Multi-link suspension
- Suspension of the semi-trailing arm
- Swing arm
- Leaf springs
- The transverse leaf spring when used as a suspension link, or a four-quarter ellipse on one end of the car similar to wishbones in geometry, but more appropriate. Examples are the original Fiat 500 front, Panhard Dyna Z and early examples of Peugeot 403 as well as the rear of AC Ace and AC Aceca.
Because the wheels are not limited to remain perpendicular to the flat road surface in bends, braking and load conditions, camber wheel control is an important issue. The swing arm is common in small cars that sprang up gently and can carry large loads, because the camber does not depend on the load. Some active and semi-active suspensions maintain elevated heights, and therefore camber, independent of the load. In a sports car, the optimum camber change when turning is more important.
Wishbone and multi-link enables engineers to better control the geometry, to arrive at the best compromise, rather than swing axle, MacPherson strut or swinging arm do; but the cost and space requirements may be greater. The semi-trailing arm is between the two, being a variable compromise between the geometry of the swing arm and the swing axis.
Suspension semi-independent
In a semi-independent suspension, the shaft wheels can move relative to each other as in independent suspension but the position of one wheel has an effect on the position and attitude of the other wheel. This effect is achieved through twisting or deflecting the suspension components under load. The most common type of semi-independent suspension is a rotary beam.
- Rotate blocks
Tilt the Suspension System
The Tiling Suspension System is not actually a different type or different construction geometry, let alone it is an additional technology in a conventional suspension system.
Such suspension systems consist primarily of independent suspensions (eg, MacPherson strut, A-arm (double wishbone)). With the addition of this suspension system there is a tilt or slant mechanism that connects the suspension system with the vehicle body (chassis).
This suspension system improves stability, traction, rotation of vehicle radius and rider comfort as well. When turning passengers or objects to the right or left of the vehicle, feel the G-style or inertial force outside the radius of curvature, which is why the Two Wheeler rider is leaning toward the center of curvature while turns that improve stability and reduce the possibility of rolling. But for vehicles more than two wheels and with conventional suspension systems can not do the same until now so passengers feel the inertial force out which reduces passenger stability and comfort as well. This tilted suspension system is the solution of the problem. If the road does not have a super-elevation or banking it will not affect the comfort with this suspension system, the tilt of the vehicle and lower the height of the center of gravity by increasing stability. It is also used in a fun vehicle.
Some trains also use tilting suspension (Tilting Train) with increased speed during cornering.
Mechanism of Rocker bogie
The rocker-bogie system is a suspension setting where there are multiple trailing arms equipped with some idler wheels, as the articulation between the driving part and the suspension follower is very flexible. Such suspensions are suitable for very rough terrain.
Such suspensions are used in Curiosity rover.
Traced vehicle
Some vehicles such as trains run on long railroad tracks mounted to the ground, and some like tractors, snowmobiles and tanks run on continuous rails that are part of the vehicle. Although both help level the road and reduce soil pressure, many of the same considerations apply.
Suspension of armored combat vehicle
Military AFVs, including tanks, have special suspension requirements. They can weigh over seventy tons and are required to move as fast as possible on very rough or soft ground. Their suspension components should be protected from land mines and antitank weapons. Tracked AFVs can have as many as nine wheeled roads on each side. Many AFV wheels have six or eight large wheels. Some have the Central Tire Inflation System to reduce ground loading on poor surfaces. Some wheels are too large and limited to turn, so steering wheel is used with wheel vehicles, as well as with tracked vehicles.
The earliest tanks of World War I have fixed suspensions without a completely designed movement. This unsatisfactory situation improved with leaf springs or spring coil suspensions adopted from agricultural, automotive or rail machines, but even this journey was very limited.
Speed ​​increases because the engine is more powerful, and the quality of driving should be improved. In the 1930s, the Christie suspension was developed, allowing the use of coil springs inside the armored vehicle's hull, by changing the direction of the spring deformation force, using a crank bell. The T-34 suspension is directly derived from the Christie design. Horstmann suspension is a variation that uses a combination of a crankbell and an exterior coil springs, which were used from the 1930s to the 1990s. The bogie, but remains independent, the M3 Lee/Grant and M4 Sherman suspensions are similar to the Hortsmann type, with the suspension contained in the oval tracks.
In World War II, another common type is the torque rod suspension, obtaining spring strength from the curved blades inside the hull - this sometimes has less travel than the Christie type, but is significantly more compact, allowing more space in the stomach, with consequences the possibility to install a larger turret ring and thus the heavier main weaponry. The torque rod suspension, sometimes including shock absorbers, has been the dominant heavy-duty vehicle suspension since World War II. Torsion bars can take up space under or near the floor, which can disrupt the manufacture of low tanks to reduce exposure.
Like a car, wheel travel and spring speed affect the speed of ride and speed in rough terrain can be negotiated. It may be significant that smooth ride, which is often associated with comfort, improves accuracy when shooting moves (analog to battle vessels with reduced stability, due to the reduced metacentric height). It also reduces shock on optics and other equipment. Unsprung weight and heavy track links can limit the speed on the road and affect the life of tracks and other components.
Most of the tracks are half the German WW II and their tanks that were introduced during the war such as Panther tanks have overlapping and sometimes interleaved road wheels to distribute loads more evenly on the track and therefore on the ground. This appears to contribute significantly to accelerating, reaching and tracking life, and providing ongoing protection. It has not been used since the end of the war, probably because of the maintenance requirements of the more complicated mechanical parts that work in mud, sand, rock, snow and ice, as well as cost. Frozen rocks and sludges are often trapped between overlapping wheels, which can prevent it from deflecting or causing damage to the wheels. If one of the inner road wheels is damaged, another wheel is needed to be removed in order to access the damaged road wheel, making the process more complicated and time-consuming.
See also
- 4-poster - test tool
- 7 post shakers - test rigs for high speed vehicles
- Automotive suspension design - design process
- Self-centered caster angle
- Coilover
- Corvette leaf springs - independent suspension combined with leaf-fiber reinforced transverse spurs
- Korres P4 - Greek all-round supercar, with unique suspension
- Magnetic Levitation
- Maglev Train
- Radius scrub
- Long short sleeve suspension - also known as "unbalanced arm", one of the double wishbone suspension design parameters
- Strut bar - semi-independent suspension form
- Oleo strut - the design used in most large aircraft, with compressed gas and hydraulic fluid - is conceptually similar to the car's Hydropneumatic suspension
References
External links
- How Car Suspension Works
- Robert W. Temple, ABC Chassis Frame and Suspensions , September 1969
- Suspension Geometry Calculator
Source of the article : Wikipedia
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