162 results about "Tire uniformity" patented technology

A system and related method for improving tire uniformity includes providing a number (n) of test tires manufactured in a known order and identifying at least one candidate cyclic process effect with a corresponding frequency of introduction (f). A given uniformity parameter, such as radial or lateral run-out, balance, mass variation, radial lateral or tangential force variation, is measured for each tire in the test set, and measured data points are combined into a concatenated composite waveform. At least one process harmonic associated with each identified cyclic process effect is separated from the tire harmonics, for example, by Fourier transformation with identification of the process harmonics as positive integer multiples of the mth harmonic of the measured uniformity parameter where m=n/f. Once the process harmonics are extracted, filtered uniformity measurements can be provided or new tires can be built with the process effect minimized.

A system and related method for improving tire uniformity includes identifying at least one candidate process effect and a corresponding process harmonic number for each process effect. A given uniformity parameter, such as radial or lateral run-out, balance, mass variation, radial lateral or tangential force variation, is measured for each tire in a test set, such that the measurements contain tire harmonics as well as a process harmonics corresponding to each candidate process effect. Rectangular coordinate coefficients are electronically constructed for each said process harmonic, after which point the rectangular coordinates corresponding to each process harmonic are solved for (e.g., by using regression-based analysis). The magnitude of each said process harmonic is estimated, and a final magnitude estimate for each process harmonic can be determined by summarizing (e.g., by taking the average or median value) the respectively estimated magnitudes for each process harmonic across all test tires.

Improved and more easily implemented methods for predicting high speed radial force variation and uneven mass distribution utilize other measurements such as radial nm out and other parameters. The prediction model for high speed radial force variation uses a speed-dependent calibration term for predicting higher harmonic components, while the same or other models can be used for the first harmonic. The uneven mass distribution prediction model accounts for deformation of the tire along multiple tracks, thus employing a more realistic model of crown deformation that accounts for changing tire stiffness levels across different harmonic components of the measured and predicted parameters.

Improved and more easily implemented methods for predicting uniformity parameters such as uneven mass distribution, radial run out and high speed radial force variation utilize other measurements such as the tire crown thickness variation. When high speed radial force variation is calculated, low speed radial force variation is also measured. Tire crown thickness variation can be measured in different fashions depending on the particular tire manufacturing process employed. By electronically determining resultant uniformity parameters, tires can be improved by rectification to address the uniformity levels. In addition, tire manufacturing can be improved by altering the resultant location of tire crown thickness variation relative to other aspects of the tire and/or tire manufacturing process.

There is provided a method of tire manufacturing a tire in which preset-beads each preformed by mounting a bead filler on a bead core are disposed radially outward of a carcass band and both side portions of the carcass band are turned around the preset beads to build the tire. The method eliminates a need to bold the considerable intermediate stocks and does not deteriorate the tire uniformity due to the unevenness of the preset bead in the circumference direction. There are also provided an apparatus of forming a preset bead used therefore and a system of forming a preset bead. In the method of manufacturing a tire in which preset-beads each preformed by mounting a bead filler on a bead core are disposed radially outward of a carcass band and both side portions of the carcass band are turned around the preset beads to build the tire, the preset bead is formed by winding and laminating a ribbon-shaped filler rubber 5 radially outward of the bead core 10 over several laps.

A system and related method for improving tire uniformity includes providing at least one set of test tires constructed with one or more process elements provided at known relative angular locations. At least one uniformity parameter, such as radial or lateral run-out, balance, mass variation, radial lateral or tangential force variation, is measured for at least one harmonic of interest for each test tire. Respective rectangular coordinates are determined for each measured uniformity parameter and harmonic of interest for each tire. A form of the determined rectangular coordinates (e.g., the rectangular coordinates themselves and/or the log of the residuals squared) is analyzed for each tire to identify optimized relative angular locations for each process element that reduce dispersion (or dispersion and mean) of the measured uniformity parameter. New tires are built with the one or more process elements positioned in the identified optimized relative angular locations.

A tire manufacturing method includes a method for optimizing the uniformity of a tire by reducing the after cure radial force variation. The after cure radial force variation vector is modeled as a vector sum of each of the vectors representing contributions arising from the tire building steps—the “tire room effect vector” and a vector representing contributions arising from the vulcanization and uniformity measurement steps—the “curing room effect vector.” In further detail, both the tire room and curing room effect vectors can be further decomposed into sub-vectors representing each radial force variation contribution for which a measurable indicator is available. For a series of tires, the method obtains such measurements as the before cure radial runout (RRO) at one or more stages of the building sequence, measurements of loading angles on the tire building equipment, and measurements made during vulcanization process.

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.

A tire comprising a tread layer comprised of a tread rubber and an electrically conductive band arranged in a widthwise middle portion thereof, and a method of producing the tire, wherein the tread rubber is made of a low-conductive continuous rubber ribbon circumferentially wound plural times, and the electrically conductive band is made of a high-conductive thin annular rubber sheet. Also, the electrically conductive band is arranged so as to extend in the widthwise region ranging from a part of the top face of the first tread rubber portion to a part of the bottom face of the second tread rubber portion, whereby the tire uniformity is improved and the production is possible in a multi-size mixed production system and the conductive path from the belt to the treading face can be surely formed at a low cost.

A tread feed rack and a feed method thereof of the invention can simultaneously satisfy centering and length control demands for tread materials. In a cutting process, a cutter slides on a sliding track of a cutter carrier by a driving mechanism, and in a process that the cutter slides downwards, the cutter cuts off the tread by a shoveling manner. The cutter carrier of the feed rack is fixed on a frame at two sides of a conveying template, the sliding track is arranged on the cutter carrier, the sliding track forms a certain included angle with the tread conveying direction, and the cutter is slidingly connected with the sliding track. The tread feed rack and feed method thereof of the invention can eliminate the influence on centering in the cutting process, simultaneously eliminates length control error influence on the tyre homogeneity.

A tire manufacturing method includes a method for optimizing the uniformity of a tire by reducing the green tire radial runout. The green tire radial runout is modeled as a vector sum of each of the vectors representing contributions arising from the tire building steps. A set of vector coefficients is generated from the vector equation. The building steps include building the tire carcass, building the tire summit, transferring the summit onto the inflate carcass, and measuring the radial runout and tooling angles at each step in the process. After the model is built the vector equations and coefficients are applied to subsequent tires. By adjusting the tooling angles, green tire radial runout can be optimized.

Methods and systems for a computer implemented method of analyzing a vehicle wheel assembly including a tire and a rim is provided. The method includes removably mounting a wheel assembly on a shaft having a longitudinal axis and being rotatable about the longitudinal axis to rotate the wheel assembly, applying a substantially radial force to the wheel assembly during rotation thereof, and measuring variations in the radial force from at least one of radial runout, tire uniformity, and tire flatspotting. The method also includes determining a condition of the wheel assembly based on a spectral density analysis of the measured variations.

In a tire uniformity measurement, accurate tire uniformity is obtained from a measurement waveform immediately after a rotation of a tire is switched from a normal rotation direction to a reverse rotation direction. A tire uniformity testing device of the present invention includes a measurement unit 108 that obtains a force variation from a uniformity waveform corrected by a correction unit 109 that corrects the uniformity waveform so as to eliminate a shift gradient α existing in the uniformity waveform measured after a rotation of a tire T1 is reversed, and further includes an air-outflow regulation member 220 that regulates an from flowing into a tire T2 when a drum 205 retreats or advances.