|
Corvette leaf spring commonly refers to a type of independent suspension which utilizes a fiber-reinforced plastic (FRP) mono-leaf spring instead of more conventional coil springs. A notable characteristic of this suspension configuration is the mounting of the mono-leaf spring such that it can serve as both ride spring and anti-roll spring. In contrast to many applications of leaf springs in automotive suspension designs, this type does not use the spring as a locating link. While this suspension type is most notably associated with several generations of the Chevrolet Corvette the design has been used in other production General Motors cars as well as vehicles from Volvo and Mercedes-Benz. Fiat and Zastava produced cars with a similar configuration using a multi-leaf steel spring in place of the FRP mono-leaf spring. Other manufactures and suppliers have researched variations of this suspension design. == Design == This suspension configuration is independent and utilizes control arms to define the motion of the wheel as the suspension is compressed. The coil springs are replaced with a single, FRP spring which spans the width of the car. As in independent suspension systems using coil springs, and unlike the common leaf spring supported Hotchkiss rear axle, the suspension kinematics are defined only by the control arms. Because the movement of one wheel is not determined by the position of the other this is an independent suspension type. As in a coil spring suspension design, the FRP mono-leaf spring supports the weight of the vehicle. However, the FRP leaf springs differ from steel coils and traditional steel multi-leaf springs in a number of significant ways. The FRP plastic springs have 4.3–5.5 times the strain energy storage per weight as compared to steel. This results in a lighter spring for a given application. The single FRP mono-leaf front spring used on the fourth generation Corvette weights 33 percent of the weight of an equivalent set of coil springs. FRP spring weight savings as compared to conventional leaf springs in similar applications are even greater. The third generation Corvette offered an optional FRP mono-leaf spring as an alternative to the standard multi-leaf steel spring. The steel spring was replaced by a mono-leaf spring. Volvo claims a weight savings of by using a FRP spring in the rear suspension of the second generation XC90 as compared to designs using coil springs. In addition to reduction in vehicle weight, the weight of the spring is partly unsprung mass. The relative sliding movement of the leaves of a multi-leaf steel spring results in stiction based hysteresis with respect to spring compression. This stiction reduces suspension compliance and can compromise both ride quality and handling. Lacking individual leaves, the mono-leaf spring avoids stiction. FRP springs are advertised as having exceptional cycle life and corrosion resistance.〔 A GM test comparing the third generation Corvette springs found the multi-leaf steel springs failed spec after 200,000 full travel cycles. The replacement FRP leaf spring showed no loss of performance after two million full cycles.〔 Packaging is cited as both an advantage and disadvantage of the transverse FRP leaf spring as compared to coil springs depending on the application. The FRP spring is typically packed low in the suspension resulting in a low center of gravity. It also allows manufactures to avoid tall spring mounts thus resulting in a flatter load floor about the suspension.〔 James Schefter reports that as used on the C5 and later Corvettes the use of OEM coilover damper springs would have forced the chassis engineers to either vertically raise the shock towers or move them inward. In the rear this would have reduced trunk space. In the front this would have interfered with engine packaging. The use of the leaf spring allowed the spring to be placed out of the way under the chassis and while keeping the diameter of the shock absorber assembly to that of just the damper rather than damper and spring. However, in other applications such as race car designs, the need to span the width of the vehicle result in significant design limitations. Coil and torsion springs present better packaging options for racing applications. FRP springs also have limited availability and selection as compared to coil spring. Higher cost has also been cited as a disadvantage when compared to coil springs on production road cars. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Corvette leaf spring」の詳細全文を読む スポンサード リンク
|