Prediction and control of mass unbalance and high speed uniformity

Abstract

Methodology for characterizing non-uniformity forces at a tire spindle, such as low and high speed radial force variations and high speed tangential force variations include the steps of measuring radial run out and radial or tangential force variations at high and / or low speeds. From such measurements, the contribution of a predetermined type of stiffness variation (e.g. radial, tangential, extensional, bending) to respective radial and / or tangential force variations can be determined. Signature analysis statistical methods may also be utilized to characterize such tire non-uniform forces for different steps and reference physical angles of a tire construction process. Based on the characterization of such tire non-uniform forces, additional process steps may further correspond to tire grading and / or sorting processes, physical tire modification processes and tire manufacturing processes. Tire correction mechanisms and / or feedback control in a tire manufacturing process preferably yield tires having radial run out and stiffness variation parameters that are out of phase for one or more harmonics, thus yielding a reduction in the non-uniformity forces such as radial and tangential force variations at a tire spindle.

Description

FIELD OF THE INVENTION [0001] The present invention generally concerns technology for characterizing tire uniformity performance parameters, such as radial and tangential force variations that affect tire uniformity at both low and high speeds. Characterization and prediction of such tire parameters and others may subsequently be used to grade, sort, or provide correction to manufactured products and / or control manufacturing aspects thereof. BACKGROUND OF THE INVENTION [0002] One exemplary cause of vehicle vibrations at both high and low traveling speeds corresponds to force variations at respective tire spindle locations. This phenomenon is typically referred to as tire uniformity. Tire high speed uniformity (HSU) may be of particular interest as related to tire performance levels, since potential non-uniformity characteristics of a tire can produce a significantly greater amount of vibration at faster highway road speeds, such as those in excess of 25 mph. [0003] High speed unifor...

AI Technical Summary

Benefits of technology

[0008] In view of the recognized features encountered in the prior art and addressed by the present subject matter, improved technology is presented for characterizing non-uniformity forces at a tire spindle. More particularly, features for characterizing radial force variations at high and low speeds and tangential force variations at high speed are presented. Characterization can be further applied to tire grading and / or sorting processes, physical tire modification processes and tire manufacturing processes.

[0017] Additional embodiments of the subject technology combine aspects of the above methods for characterizing high speed radial / tangential force variations methods of manufacturing tires, in which the characterization steps are applied to each tire in a plurality of sets of tires that are constructed such that each set has a different combination of reference physical angles for different steps of the tire building process. The reference physical angles may correspond to the locations of overlap or variation in multiple respective tire layers. Low and high speed RRO and RFV / TFV measurements are obtained for each tire in each constructed set, from which respective RSV contributions can be determined. A statistical method, such as a signature analysis, may be applied to estimate high speed RRO and RSV signatures for each step in the tire building process, from which a determination can be made regarding which tire set's combination of relative angles of the different tire building process steps results in high speed RRO and RSV signatures being out of phase for one or more harmonics, thus yielding reduced levels of radial / tangential force variation at high speed. Again, other types of stiffness variation than the RSV may be the focus of such exemplary methodology.

[0016] In still further exemplary embodiments of the present subject matter, high speed radial / tangential force variations in a tire may be compensated by creation of additional stiffness variation as opposed to creation of additional radial run out. In accordance with such an exemplary embodiment, radial run out of one or more constructed tires is obtained. The radial run out measurements may occur at a predetermined rotational speed such as one greater than about 300 rotations per minute and at a relatively low pressure such as less than about 1.0 bar. From the radial run out measurements, a value for stiffness variation (e.g., one or more of radial, tangential, bending, and extensional stiffniess variations) may be determined that would result in minimized radial / tangential force variations for the measured radial run out values. Such a determined stiffness variation may then be created, such as in subsequently created tires by applying feedback to one or more steps of a tire building process.

Problems solved by technology

Therefore, at relatively higher speeds, Fx can potentially be quite large.

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