US 6,856,929 B1Granted

Tire manufacturing method for improving the uniformity of a tire

Assignee7 Michelin Recherche et Technique

InventorsWilliam David Mawby, George P. O'Brien, Eugene Marshall Persyn, James Michael Traylor

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Abstract

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.

Claims17

Dependent claims

A method for improving the uniformity of a tire comprising the steps of:

(a) Determining a set of vector coefficients corresponding to the after cure radial force variation of a tire, comprising the sub-steps of:
(i) Recording a loading angle of a tire carcass on a measurement fixture,
(ii) Measuring the before cure radial runout of a plurality of finished tires,
(iii) Recording a loading angle of said finished tires in a curing mold and curing said tires,
(iv) Measuring the after cure radial force variation for each of said tires,
(v) Extracting at least one harmonic of the radial runout and of the radial force variation of said tires,
(vi) Determining a set of vector coefficients relating the before cure radial runout to the after cure radial force variation of said tires cured in said mold,
(vii) Storing said vector coefficients,
(b) Estimating the after cure uniformity of an individual tire comprising the sub-steps of:
(i) Recording a loading angle of a carcass of said individual tire on said measurement fixture
(ii) Measuring the before cure radial runout of said individual tire,
(iii) Choosing a harmonic of radial force variation to be optimized,
(iv) Extracting a harmonic of radial runout of said individual tire,
(v) Estimating a tire room effect vector of the radial force variation corresponding to said harmonic,
(vi) Estimating a curing room effect vector of the radial force variation corresponding to said harmonic,
(c) Optimizing the after cure uniformity of an individual tire comprising the sub-steps of:
(i) Determining an azimuth of said tire room effect vector and of said curing room effect vector,
(ii) Aligning the angular position of said individual tire such that said azimuth of said tire room effect vector opposes said curing room effect vector, and
(iii) Placing said individual tire so aligned in said curing mold and curing said tire.

16 more elements

Dependencies are inferred from the claim text.