A
de Dion tube is an
automobileAn automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
suspensionSuspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. Suspension systems serve a dual purpose — contributing to the car's roadholding/handling and braking for good active safety and driving pleasure, and keeping vehicle occupants...
technology. It is a sophisticated form of non-
independent suspensionIndependent suspension is a broad term for any automobile suspension system that allows each wheel on the same axle to move vertically independently of each other. This is contrasted with a beam axle, live axle or deDion axle system in which the wheels are linked – movement on one side affects...
and is a considerable improvement over the alternative
swing axleA swing axle is a simple type of independent suspension first used in early aircraft , such as the Sopwith and Fokker, usually with rubber bungee and no damping....
and
Hotchkiss driveThe Hotchkiss drive is a system of power transmission. It was the dominant form of power transmission for front-engine, rear-wheel drive layout cars in the 20th century...
types. A de Dion suspension uses
universal jointA universal joint, universal coupling, U joint, Cardan joint, Hardy-Spicer joint, or Hooke's joint is a joint or coupling in a rigid rod that allows the rod to 'bend' in any direction, and is commonly used in shafts that transmit rotary motion...
s at both the wheel hubs and
differentialA differential is a device, usually, but not necessarily, employing gears, capable of transmitting torque and rotation through three shafts, almost always used in one of two ways: in one way, it receives one input and provides two outputs—this is found in most automobiles—and in the other way, it...
, and uses a solid tubular beam to hold the opposite wheels in parallel. Unlike an anti-roll bar, a de Dion tube is not directly connected to the
chassisA chassis consists of an internal framework that supports a man-made object. It is analogous to an animal's skeleton. An example of a chassis is the underpart of a motor vehicle, consisting of the frame with the wheels and machinery.- Vehicles :In the case of vehicles, the term chassis means the...
nor is it intended to flex. In suspension geometry it is close to the
trailing beam suspensionA beam axle is a suspension system, also called a solid axle, in which one set of wheels is connected laterally by a single beam or shaft...
seen on many front wheel drive cars, but without the torsional flexibility of that suspension.
History
The de Dion tube was named after Comte Jules-Albert de Dion, founder of
FrenchThe French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
automobile manufacturer
De Dion-BoutonDe Dion-Bouton was a French automobile manufacturer and railcar manufacturer operating from 1883 to 1932. The company was founded by the Marquis Jules-Albert de Dion, Georges Bouton and his brother-in-law Charles Trépardoux....
. The tube, however, was invented around 1894 by co-founder Charles Trépardoux for use on the company's steam tricycles.
Advantages and disadvantages
The benefits of a de Dion suspension include:
- Reduced unsprung weight
In a ground vehicle with a suspension, the unsprung weight is the mass of the suspension, wheels or tracks , and other components directly connected to them, rather than supported by the suspension...
compared to the Hotchkiss drive since the differential is connected to the chassis.
- Unlike a fully independent suspension there are no camber
thumb|100px|From the front of the car, a right wheel with a negative camber angleCamber angle is the angle made by the wheels of a vehicle; specifically, it is the angle between the vertical axis of the wheels used for steering and the vertical axis of the vehicle when viewed from the front or...
changes on suspension unloading (or rebound). Fixing the camber of both wheels at 0° assists in obtaining good traction from wide tires and also tends to reduce wheel hop under high power operations compared to an independent suspension.
There are costs, however:
- A pair of CV or universal joints are required for each wheel, adding complexity and weight.
- If coil springs are used then a lateral location link (usually either a Panhard rod
A Panhard rod is a component of a car suspension system that provides lateral location of the axle...
or Watt's linkageWatt's linkage is a type of mechanical linkage invented by James Watt in which the central moving point of the linkage is constrained to travel on an approximation to a straight line...
), plus additional torque links on each side (five link suspension) or a combination of lower trailing links and an upper transverse wishbone are required. None of these additional links are required if leaf springs are used, but ride can be compromised due to the leafs having to do double duty as both locating links and springs.
- Sympathetic camber changes on opposite wheels are seen on single-wheel suspension compression. This is not important for operation on improved surfaces but is more critical for rough road or off road use.
- Compared to a fully independent rear suspension the ability to refine the dynamic response of the vehicle is somewhat limited.
Use in production cars
Older cars
In addition the original
Mazda CosmoThere have been four generations of Mazda automobiles which went by the name of Cosmo, although they are not all particularly related. All were Grand tourers, with the first proving a successful launch for the Mazda Wankel engine and acting as a "halo" vehicle for the new Mazda brand...
,
Alfa Romeo AlfettaAlfa Romeo GTV redirects here. For 916 series GTV see Alfa Romeo GTV & SpiderThe Alfa Romeo Alfetta is an Italian rear-wheel drive executive saloon car and fastback coupé produced from 1972 until 1987 by Alfa Romeo...
, GTV6,
GiuliettaThe Alfa Romeo Giulietta is an automobile manufactured by the Italian car maker Alfa Romeo. The car was introduced in November 1977 and while it took its name from the original Giulietta of 1954 to 1965, it was a new design based on the Alfa Romeo Alfetta chassis .-History:At the beginning, two...
,
Alfa 6The Alfa Romeo Alfa 6 is an executive car produced by the Italian automaker Alfa Romeo from 1979 to 1986.On its launch in 1979, the Alfa 6 was the flagship of the Alfa Romeo range...
,
90The Alfa Romeo 90 is an executive car produced by the Italian automaker Alfa Romeo between 1984 and 1987.Designed by Bertone and introduced at the 1984 Turin Motor Show, the 90 was pitched between the Alfa Romeo Alfetta and the Alfa Romeo Alfa 6, both of which were soon discontinued after the 90's...
,
75/MilanoThe Alfa Romeo 75, sold in North America as the Milano, was a compact sports saloon / compact executive car produced by the Italian automaker Alfa Romeo between 1985 and 1992...
,
Lancia AureliaThe Lancia Aurelia is a car that was produced by the Italian manufacturer Lancia. Designed by Vittorio Jano, the Aurelia was launched in 1950 and production lasted until the summer of 1958....
(fourth series onwards), first and second generation Prince Gloria,
Lancia FlaminiaThe Lancia Flaminia is a luxury car from the Italian automaker, Lancia, built from 1957 to 1970. It was Lancia's flagship model at that time, replacing the Aurelia. It was available throughout its lifetime as saloon, coupé and cabriolet. The Flaminia coupé and cabriolet were coachbuilt cars with...
,
Volvo 300-seriesThe Volvo 300 series is a rear wheel drive automobile sold as both a hatchback and a conventional saloon from 1976-1991. It was launched in the Netherlands shortly after Volvo acquired a major stake in the passenger car division of DAF in 1973...
,
Rover P6The first P6 used a 2.0 L engine designed specifically for the P6. Although it was announced towards the end of 1963, the car had been in "pilot production" since the beginning of the year, therefore deliveries were able to begin immediately. Original output was in the order of . At the...
and Dodge Caravan & Grand Caravan (all wheel drive version from 1991–2004), DAF 46, DAF 66, are examples of production vehicles using this suspension. Some of the largest Opels, such as the
Opel DiplomatThe Opel Diplomat is a large car manufactured by Opel. Opel's range-topping models were traditionally the Admiral and Kapitän, introduced in 1937 and 1938 respectively....
"B" of 1969, all
Aston MartinAston Martin Lagonda Limited is a British manufacturer of luxury sports cars, based in Gaydon, Warwickshire. The company name is derived from the name of one of the company's founders, Lionel Martin, and from the Aston Hill speed hillclimb near Aston Clinton in Buckinghamshire...
s from 1967 to 1989,
FerrariFerrari S.p.A. is an Italian sports car manufacturer based in Maranello, Italy. Founded by Enzo Ferrari in 1929, as Scuderia Ferrari, the company sponsored drivers and manufactured race cars before moving into production of street-legal vehicles as Ferrari S.p.A. in 1947...
375 and 250TR,
MaseratiMaserati is an Italian luxury car manufacturer established on December 1, 1914, in Bologna. The company's headquarters is now in Modena, and its emblem is a trident. It has been owned by the Italian car giant Fiat S.p.A. since 1993...
Quattroporte,
BugattiAutomobiles E. Bugatti was a French car manufacturer founded in 1909 in Molsheim, Alsace, as a manufacturer of high-performance automobiles by Italian-born Ettore Bugatti....
251,
Mercedes-BenzMercedes-Benz is a German manufacturer of automobiles, buses, coaches, and trucks. Mercedes-Benz is a division of its parent company, Daimler AG...
W125 and W154 as well as
Auto UnionAuto Union was an amalgamation of four German automobile manufacturers, founded in 1932 and established in 1936 in Chemnitz, Saxony, during the Great Depression. The company has evolved into present day Audi, as a subsidiary of Volkswagen Group....
Type D also used this suspension.
Recent cars
The
Smart FortwoThe Smart Fortwo is a rear-engined two-seater city car manufactured by Smart GmbH, introduced at the 1998 Paris Motor Show as the Smart City Coupé, and currently in its second generation...
and Smart Roadster micro-compact cars produced by Daimler AG,
Mitsubishi iThe is a kei car from Japanese automaker Mitsubishi Motors, first released in January 2006, twenty eight months after its debut at the 2003 Frankfurt Motor Show...
kei carKei cars, K-cars, or , are a Japanese category of small vehicles, including passenger cars, vans, and pickup trucks. They are designed to comply with Japanese government tax and insurance regulations, and in most rural areas are exempted from the requirement to certify that adequate parking is...
produced by Mitsubishi Motors and the Caterham 7 (a development of the
Lotus SevenThe Lotus Seven is a small, simple, lightweight two-seater open-top sports car produced by Lotus Cars between 1957 and 1972....
after Lotus sold the design rights to
Caterham CarsCaterham Cars is a manufacturer of specialist lightweight sports cars based in Caterham, Surrey, England and part of the British motor industry. Their only current model, the Caterham 7 , is a direct evolution of the Series 3 Lotus Seven designed by Colin Chapman and originally launched in 1968. A...
), are the only cars currently in production that utilize this arrangement, as well as the products of some
kit carA kit car, also known as a "component car", is an automobile that is available as a set of parts that a manufacturer sells and the buyer then either assembles into a car themselves, or retains a third party to do part or all of the work on their behalf...
companies. A recent vehicle to use this suspension coupled with leaf springs was the
Ford Ranger EVThe Ford Ranger EV is a battery electric vehicle produced by Ford Motor Company. It was produced starting in the 1998 model year through 2002 and is no longer in production. It is built upon a light truck chassis used in the Ford Ranger. A few vehicles with lead-acid batteries were sold, but most...
. The American built MV-1 van by VPG also uses this suspension in the rear with leaf springs and is just starting production in spring 2010.