166 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.

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 presenting 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.

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.

A grinder assembly (10) contacts a tire (T) supported by a frame (F) relative to the tire (T). The grinder assembly (10) includes at least one section, and a vertical repositioning system (118) supporting the at least one section. The vertical repositioning system (118) enables the at least one section to be vertically repositioned relative to the tire (T). The at least one section includes a grinding head (24), a radial positioning system (18) supporting the grinding head (24) for radial movement with respect to the tire (T), and a tilt adjuster (90) provided adjacent the grinding head (24) to provide for pivotal movement thereof. The vertical repositioning system (118) includes at least one rail extending along the frame (F), and a rail carriage supporting the at least one section on the at least one rail, the rail carriage being vertically repositionable along the at least one rail.

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.

There is provided a method and a apparatus for measuring tire uniformity. The apparatus comprises a spindle, a rotating drum, a sensor and a computing means. The method comprises the steps of mounting a tire on the spindle, pressing a circumferential surface of a rotating drum against the tread surface of the tire with a first pressing force, rotating the tire around rotational axis thereof, and computing the forces which the tire acts on first and second planes of the tire by the computing means while the tire is rotating. The first plane is perpendicular to the rotational axis and in one sidewall side of the tire. The second plane is perpendicular to the rotational axis and in the other sidewall side of the tire. The forces are computed based on values obtained by the sensor measuring forces transmitted to the spindle from the tire at first and second positions. The first and second positions have different distances from the tire in the rotational axis direction.

An apparatus for changing rim sets at a testing station of a tire uniformity testing system that includes a storage unit for storing a plurality of rim set assemblies. A transfer arm is reciprocally movable and includes a gripper mechanism for gripping a rim set assembly and moving it from a storage position to a position at which rims forming part of the rim set assembly are aligned with opposed spindles at the testing station. The rim set assembly includes a bracket having structure engageable by the transfer arm and at least one of the rims forming part of the assembly includes a locking member rotatable between a first position and a second position. The bracket includes a structure for immobilizing the rim to inhibit relative rotation between the rim and the bracket and further includes a lever mechanism for moving the locking member from its first position to its second position in order to engage retaining members forming part of the bracket. The lever mechanism moves the locking member from its second position to its first position when the rim is aligned with an associated spindle in order to engage other retaining members forming part of the spindle. The rim is released from the bracket as the locking member moves to engage the other retaining members. After release, the bracket moves to a remote position spaced from the testing station. To remove the rim sets, the steps for attaching rims to the spindles are reversed in order to release the rims from the spindles while simultaneously engaging the bracket. The resulting rim set assembly is moved to a remote position defined by a storage unit that stores a plurality of rim set assemblies. The disclosed locking member and associated rim can be used to facilitate the manual installation of a test rim to a spindle.

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 uniformity testing machine includes an upper spindle including an upper rim portion, a lower spindle including a lower rim portion, and a spindle actuator such as a servo actuator adapted to vary a distance between the upper and lower spindles along a y axis. The tire testing machine also includes a conveyor adapted to move an associated tire to be tested along an x axis in a conveying direction. The conveyor is driven by a conveyor actuator said as a servo actuator. A motion controller is provided and receives x axis position feedback indicating a conveying distance moved by the conveyor along said x axis and that uses the x axis position feedback to control the spindle actuator to vary the distance between the upper and lower spindles along the y axis according to a function y=F(x) for coordinated synchronous variation of the distance between the upper and lower spindles along the y axis in response to movement of the conveyor along the x axis. The conveyor also moves vertically along the y axis and its position along with y axis can also be controlled by a servo actuator for coordinated vertical movement as a function of said x axis position feedback and / or as a function of y axis position feedback provided by said spindle actuator indicating a distance between said lower and upper spindles.

A tire uniformity machine is provided to prevent axes of rims from being misaligned while shortening a measurement cycle by installing a rim width adjustment unit in a first spindle. A tire uniformity machine includes an upper rim(2) for supporting and holding an upper bead section of a tire(1) and a lower rim(3) for supporting and holding a lower bead section of the tire(1). The upper rim(2) is detachably attached to a lower end of an upper spindle(5). The upper rim(2) is oppositely aligned with respect to the lower rim(3) by means of lower and upper spindles(4,5) in such a manner that axes of the upper and lower rims(2,3) are aligned in the same line. The lower and upper spindles(4,5) are installed on a top frame(6) and a base frame(8), respectively. The top and base frames(6,8) are supported by an installation frame(7).

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.

There is provided a method and a apparatus for measuring tire uniformity. The apparatus comprises a spindle, a rotating drum, a sensor and a computing means. The method comprises the steps of mounting a tire on the spindle, pressing a circumferential surface of a rotating drum against the tread surface of the tire with a first pressing force, rotating the tire around rotational axis thereof, and computing the forces which the tire acts on first and second planes of the tire by the computing means while the tire is rotating. The first plane is perpendicular to the rotational axis and in one sidewall side of the tire. The second plane is perpendicular to the rotational axis and in the other sidewall side of the tire. The forces are computed based on values obtained by the sensor measuring forces transmitted to the spindle from the tire at first and second positions. The first and second positions have different distances from the tire in the rotational axis direction.

A grinder assembly (10) contacts a tire (T) supported by a frame (F) relative to the tire (T). The grinder assembly (10) includes at least one section, and a vertical repositioning system (118) supporting the at least one section. The vertical repositioning system (118) enables the at least one section to be vertically repositioned relative to the tire (T). The at least one section includes a grinding head (24), a radial positioning system (18) supporting the grinding head (24) for radial movement with respect to the tire (T), and a tilt adjuster (90) provided adjacent the grinding head (24) to provide for pivotal movement thereof. The vertical repositioning system (118) includes at least one rail extending along the frame (F), and a rail carriage supporting the at least one section on the at least one rail, the rail carriage being vertically repositionable along the at least one rail.

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.

Tire-uniformity components may generate a lateral force on a vehicle body, when the vehicle is in a turning movement. The lateral force may cause vibrations on the vehicle body. The controller controls a motor of an electric power steering system to modulate an assist torque acting on steerable wheels in accordance with the tire-uniformity components. The assist torque is modulated in the same direction as the lateral force. As a result, it is possible to reduce vibrations on the vehicle body, since the modulated assist torque avoids conflict with the lateral force and release the lateral force.

Systems and methods for improving tire uniformity include identifying at least one candidate process harmonic and corresponding period. A set of uniformity waveforms is then collected for each test tire in a set of one or more test tires. To provide better data for analysis, the collection of waveforms may include multiple waveforms including measurements obtained before and / or after cure, in clockwise and / or counterclockwise rotational directions, and while the tire is loaded and / or unloaded. The uniformity waveforms may be re-indexed to the physical order of the at least one candidate process harmonic, and selected data points within the waveforms may optionally be deleted around a joint effect or other non-sinusoidal effect. The re-indexed, optionally partial, waveforms may then be analyzed to determine magnitude and azimuth estimates for the candidate process harmonics. Aspects of tire manufacture may then be modified in a variety of different ways to account for the estimated process harmonics.

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.

A method of controlling uniformity during tire manufacture includes the steps of selecting a target attribute and assigning a target value thereto, measuring the target attribute in a subject tire at a first rotational speed approximating highway speed and measuring in the subject tire indicator attributes a second rotational speed lower than the first rotational speed. The indicator attributes are condensed via a multivariate process to determine which attributes are the most strongly related to the target attribute. Next, a plurality of predictors for the target attribute is determined, each predictor having components including at least one indicator attribute. From the plurality of predictors, at least one best predictor is selected. The measurements for the indicator attributes making up the selected predictor are compared to limit values for the indicator attributes, and, responsive to the comparison, the tire manufacturing process may be controlled to correct any deviation between the measured attribute and the limit value for at least an additional subject tire. Production tires are measured for the components of the selected predictor at the second rotational speed, and a value for the target uniformity attribute is predicted based on the selected predictor for the additional subject tire. The predicted value is compared to the target value to allow for sorting or grading the tires.

A method and apparatus for testing tires. In step (110), the radial force variation is measured in the current direction of rotation. The first harmonic of this force variation is calculated in step (120) and a tire position corresponding to either zero crossing of the first harmonic is determined in step (130). In step (140), the tire position is monitored until a zero crossing is reached. The rotation direction is reversed at the appropriate location in step (150) and the test is continued.

A dynamic calibrator in an tire uniformity machine for testing a tire having a chuck assembly for receiving and chucking a tire load cell in sensing relation therewith, the load cell transmitting sensed information to a controller, the dynamic calibrator including a rotatable calibration wheel coupled to the chuck assembly; a motor assembly operatively coupled to the wheel to cause rotation thereof; and a wheel velocity sensing assembly.

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.