US 6,672,148 B2 · Method of improving steering performance robustness utilizing mass non-uniformity in tire/wheel

Abstract

The invention relates to methods for improving vehicle steering performance and robustness of that performance through control of non-uniformities in the vehicle's tires, wheels and tire/wheel assemblies as a way to overcome the tendency of many vehicle types to undergo “steering performance loss.” While minimizing lateral force variations (e.g., couple imbalance), a controlled amount of radial and/or tangential force variation is induced in one or more tire/wheel assemblies by means of mass non-uniformity, dimensional non-uniformity, and/or stiffness non-uniformity. For mass non-uniformity, the preferred method includes imparting a controlled amount of excess mass to tires, especially in the tread region, by means, for example, of a heavy splice, an extra fabric piece, or a sector of a tire component having excess mass. The excess mass is meridionally symmetric so as to induce static but not couple imbalance, thereby imparting a “residual static imbalance” (RSI) to the tire. Beneficial tangential and/or radial force variations will result in the use of such a tire, even if the tire/wheel assembly is balanced by weights added to the wheel. A method of determining steering performance robustness for a vehicle/wheel/tire construction combination comprises conducting a series of steering performance tests of the vehicle, wherein at least one of the tire/wheel assemblies has its balance condition changed for each test through a progression of values from values favorable to steering performance (e.g., RSI), through neutral values (balanced), to values unfavorable to steering performance (e.g., couple imbalance).

Claims20

Dependent claims

A method of improving steering performance robustness in a vehicle, comprising;

mounting a plurality of tire/wheel assemblies on the vehicle, said plurality of tire/wheel assemblies, including a number of front tire/wheel assemblies and a number of rear tire/wheel assemblies, each tire/wheel assembly comprising a tire mounted on a wheel, and;
imparting a controlled amount of mass non-uniformity to at least one of the tire/wheel assemblies to improve steering performance robustness, said step of imparting a controlled amount of mass non-uniformity including providing an excess amount of mass at one or more circumferential locations.

A method of determining steering performance robustness in a vehicle having a plurality of tire/wheel assemblies, including a number of front tire/wheel assemblies and a number of rear tire/wheel assemblies, each tire/wheel assembly comprising a tire mounted on a wheel, characterized by the step of:

conducting a series of steering performance tests of the vehicle, wherein at least one of the tire/wheel assemblies is selected and has its balance condition changed for each test of steering performance;
making the same balance condition changes simultaneously on all of the selected tire/wheel assemblies;
changing the balance condition of the at least one tire/wheel assembly through a progression of pre-determined values selected from values which are favorable to steering performance, values which are neutral to steering performance, and values which are unfavorable to steering performance;
and
determining that a vehicle (including the plurality of tire/wheel assemblies) with more robust steering performance is a vehicle having better steering performance when tested with at least one tire/wheel assembly having pre-determined balance condition values which are more unfavorable to steering performance.

2 more elements

Dependencies are inferred from the claim text.

Method of improving steering performance robustness utilizing mass non-uniformity in tire/wheel

Life of this patent

Method of improving steering performance robustness utilizing mass non-uniformity in tire/wheel

Life of this patent

Abstract

Claims20