BRITISH STANDARD AUTOMOBILE SERIES BS AU 50 1 0 1 1999 ISO 13326 1998 Tyres and wheels — Part 1 Tyres — Section 0 General — Subsection 1 Method of test for measuring tyre uniformity ICS 43 040 50; 83[.]
BRITISH STANDARD AUTOMOBILE SERIES BS AU 50-1 -0.1 :1 999 ISO 3326: 998 Tyres and wheels — Part : Tyres — Section 0: General — Subsection : Method of test for measuring tyre uniformity IC S 43 40 ; 83 60 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS AU 0-1 -0.1 :1 999 National foreword This British Standard reproduces verbatim ISO 3326: 998 and implements it as the UK national standard The UK participation in its preparation was entrusted to Technical Committee AUE/4, Tyres and wheels for motor vehicles, which has the responsibility to: — aid enquirers to understand the text; — present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; — monitor related international and European developments and promulgate them in the UK A list of organizations represented on this committee can be obtained on request to its secretary Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application Compliance with a British Standard does not of itself confer immunity from legal obligations Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the ISO title page, pages ii to iv, pages to and a back cover This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover This British Standard, having been prepared under the direction of the Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on May 999 © BSI 02- 2000 ISBN 80 30624 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy Amendments issued since publication Amd No Date Comments BS AU 0-1 -0.1 :1 999 Contents Page National foreword Foreword Text of ISO 332 © BSI 02 - 000 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy Inside front cover iii i ii Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy blank Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS AU 0-1 -0.1 :1 999 Contents Page Foreword iii Scope Normative references 1 Definitions Test equipment and its requirements Apparatus for measurement of forces and geometry General Structural resonant frequencies 4 External vibrations 4 Test drum 4 Test rim 4 Measuring system 5 Type inflation and deflation Optional instrumentation Ambient conditions 5 Testing 5 Preparation of the tyre for measurement 5 Measurement of forces 5 Measurement of geometrical parameters 6 Data interpretation Forces Geometry Accuracy of the instrumentation 8 Accuracy of the calibration system Annex A (informative) Optional test conditions A Purpose A Test wheels A Test mean radial force Figure — Reference axis system for forces Figure — Examples of wave shapes of forces generated by tyre Table Table Table Table Table 5 Table Table Table Table A Table A Table A 10 Descriptors: Road vehicles, tyres, pneumatic tyres, tests, determination, characteristics ii Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 02- 2000 BS AU 0-1 -0.1 :1 999 Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work of preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization Draft International Standards adopted by the technical committees are circulated to the member bodies for voting Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote International Standard ISO 13326 was prepared by Technical Committee ISO/TC 31, Annex A of this International Standard is for information only Tyres, © BSI 02-2000 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy rim s and v alv es iii iv Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy blank BS AU 50-1 -0.1 :1 999 Scope This International S tandard s p ecifies tes t methods carried out under controlled conditions for verifying the uniformity of tyres for p as s enger cars , commercial vehicles and motorcycles NO TE Lack of uniformity around a tyre p roduces variations in forces ap p lied b y the tyre to the vehicle and this influence is rep eated with each revolution of the tyre At the p res ent s tate of the art, however, it is imp os s ib le to m anufacture p erfectly uniform tyres A rigid control of the comp lete manufacturing p roces s can only minimis e the unavoidab le imp erfections of materials , comp onents and p roces s es affecting uniformity Methods for meas uring the geometrical run- out of the tyre in b oth radial and lateral directions are covered, as well as methods for meas uring the following p arameters: — radial force variation; — lateral force variation; IS O 42 49 - : 90, Motorcycle tyres and rims (Code-designated series) — Part 2: Tyre load ratings IS O 42 49 - : 97, Motorcycle tyres and rims (code-designated series) — Part 3: Rims IS O - : 94, Motorcycle tyres and rims (metric series) — Part 1: Design guides IS O - : 94, Motorcycle tyres and rims (metric series) — Part 2: Tyre dimensions and load-carrying capacities IS O 60 4- : 94, Motorcycle tyres and rims (code-designated series) — Diameter codes to — Part 1: Tyres IS O 60 4- : 90, Motorcycle tyres and rims (Code-designated series) — Diameter codes to 12 — Part 2: Rims Road vehicles — Vehicle dynamics and road-holding ability — Vocabulary IS O 885 : 991 , — p ly s teer; — conicity Not all of thes e meas urements will neces sarily b e relevant in every s ituation This International S tandard does not include methods for meas uring the static and the dynamic unb alance nor methods related to tyre- wheel IE C 6065 4- : 993 , Industrial-process measurement and control equipment — Operating conditions — Part : Climatic conditions VIM: 93 , International vocabulary of basic and general terms in metrology, BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, OIML as semb lies The test methods s p ecified in this International Definitions S tandard are not intended for the gradation of tyres For the p urp os es of this International S tandard, the or the definition of quality levels definitions given in IS O 42 - , IS O 885 , VIM and the following ap p ly Normative references The following s tandards contain p rovis ions which, NO TE S ee Figure for the axis reference s ys tem NO TE Als o refer I S O 40 00 - , I S O 400 0- , I S O 42 9- , IS O 42 9- , I S O 42 49 - , I S O 42 49- , I S O 42 49 - , IS O - , through reference in this text, constitute p rovis ions of this International S tandard At the time of p ub lication, the editions indicated were valid All s tandards are s ub j ect to revis ions and p arties to agreements b ased on this International S tandard IS O 75 - , I S O 05 4- and I S O 60 4- 3.1 uniformity state in which any characteris tic of the tyre is are encouraged to inves tigate the p os s ib ility of constant in p hase and magnitude in b oth static and ap p lying the mos t recent edition of the s tandards dynamic conditions around the circumference indicated b elow Memb ers of IE C and IS O maintain registers of currently valid International S tandards Passenger car tyres and rims — Part : Tyres (metric series) IS O 4000- : 99 , IS O 4000- : 99 4, Part 2: Rims Passenger car tyres and rims — Truck and bus tyres and rims (metric series) — Part 1: Tyres IS O 42 09- : 99 , Truck and bus tyres and rims (metric series) — Part 2: Rims IS O 42 09- : 99 , Definitions of some terms used in the tyre industry — Part : Pneumatic tyres IS O 42 - : 989, Motorcycle tyres and rims (Code designated series) — Part 1: Tyres IS O 42 49- : 985 , NO TE Uniformity is concerned with axis s ymmetry of m as s dis trib ution, geometry and forces generated when the s olid is in motion Lack of uniformity in a tyre, when it is rotating around its axis , caus es variations of forces , which m ay vary with the angular s p eed and are ap p lied to the s aid axis 3.2 peak to peak (total) difference b etween the maximum and the minimum values of meas urement signal, within a sp ecified b andwidth, during one revolution 3.3 first harmonic p eak to p eak amp litude of the fundamental frequency comp onent of the Fourier transform rep resenting the variation NO TE © BS I - 00 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy Its frequency is equal to the frequency of rotation BS AU 50-1 -0.1 :1 999 Figure — Reference axis system for forces 3.4 3.5.4 second (and higher order) harmonic ply steer peak to peak amplitude of the second (or higher component of the lateral force offset which changes order) frequency component of the Fourier sign with a change in the direction of rotation, in transform representing the variation newtons 3.5 Forces 3.5.5 3.5.1 radial force variation %F R value of the variation of the force in the radial conicity component of the lateral force offset which does not change sign with a change in the direction of rotation, in newtons direction (Z axis) of a loaded tyre which repeats 3.5.6 itself for each revolution at a fixed loaded radius and tangential force variation a constant speed, in newtons tractive force variation 3.5.2 %F lateral force variation value of the variation of the force in fore and aft %F L value of the variation of the force in the lateral direction (Y axis) of a loaded tyre which repeats itself for each revolution at a fixed loaded radius and a constant speed, in newtons T direction (X axis) of a loaded tyre which repeats itself for each revolution at a fixed loaded radius and a constant speed, in newtons NOTE Measurement of this parameter is not covered by this International Standard 3.5.3 lateral force offset lateral force deviation F L average value of the lateral force of a loaded straight free- rolling tyre, in newtons Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 02- 2000 BS AU 0-1 -0.1 :1 999 NOTE 3.6 Geometry When the tyre is spun at a constant angular velocity the dynamic unbalance generates a bending moment 3.6.1 perpendicular to the rotation axis given by: M = (I – I ) ì sin ì ấ tyre radial run-out a variation of the tyre radius measured d M, Ê, where sin µ is approximated by µ NOTE A pneumatic tyre is actually a deformable solid, which I I , and therefore the relative positions of their perpendicularly to the spin axis on a circumference means that along the tread surface, excluding the influence of axes in space, may vary with the rotational speed In practical the various grooves and vents located on the tread, terms it should be assumed that in millimetres 3.8 a and d a and I d are functions of Ê phase 3.6.2 angular orientation of the tyre related to a reference tyre lateral run-out variation of the distance from a fixed reference point plane, normal to the spin axis, of a given tyre 3.9 sidewall at a given distance from said axis, direction of rotation excluding the influence of the lettering and other markings on the sidewall, in millimetres direction of rotation as perceived from the operating position 3.6.3 see Figure test rim radial run-out NOTE Positive rotation of the drum is assumed to be a rotation around the Y axis, when the Z axis moves clockwise onto the X variation of the wheel radius measured perpendicularly to the spin axis on a circumference axis 3.1 along the bead seat, in millimetres NOTE I test drum It is measured separately for each bead seat rotating cylindrical flywheel 3.6.4 test rim lateral run-out variation of the distance from a fixed reference Test equipment and its requirements plane, perpendicular to the spin axis, of the inside 4.1 Apparatus for measurement of forces and vertical portion of the rim flange at a given distance geometry from said axis, in millimetres 4.1 NOTE It is measured separately for each rim flange General 4.1 1 The equipment for the measurement of 3.7 Mass distribution forces and geometry shall include 3.7.1 — an axle or spindle supporting a rim on which unbalance the tyre may be readily mounted, static unbalance (3.7.2 ) or dynamic — a test drum, the axis of which is parallel to said unbalance (3.7.3 ) or both axle, 3.7.2 — a means for loading the tyre against the drum static unbalance (or pushing the drum against the tyre) at a product ( specified force and/or for holding a fixed m × e) of the mass m of the tyre times the eccentricity e of its centre of gravity, expressed in gram millimetres NOTE When the tyre is spun at an angular velocity static unbalance generates a centrifugal force rotational axis, given by: F =m×e×Ê z NOTE F z Ê, the normal to the measurements, — equipment to measure the force components in the radial (Z axis) and lateral (Y axis) directions while the tyre and the drum are rotated at A pneumatic tyre is actually a deformable solid, which means that the distribution of mass, and therefore the speed Therefore in practice it should be assumed that Ê prescribed speed, and — optionally, means for rapid inflation and eccentricity of the centre of gravity, may vary with the rotational function of tyre- to- drum axis distance during e is a deflation of the tyre and for control of inflation pressure during rotation 3.7.3 4.1 The parallelism of the two axes of rotation dynamic unbalance shall be kept below I I ) ì of the axial inertia I minus the diametrical inertia I times the misalignment µ the product ( a d a d between the tyre main inertia axis and the tyre rotation axis, measured on a tyre running freely, 0, 25 mm/m when loaded with a radial force (Z axis) of kN and a lateral force of 500 N if the apparatus is equipped with a test drum of type A (preferred outer diameter 854 mm) , expressed in gram square millimetres © BSI 02- 2000 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy BS AU -1 -0 : 999 0,5 mm/m when loaded with a radial force The width of the drum surface shall be greater (Z axis) of 40 kN and a lateral force of kN if the than the footprint of the tyre tested apparatus is equipped with a test drum of type B The drum shall be provided with a (preferred outer diameter 600 mm) high-friction coarse-textured outer surface in order NOTE It is desirable that the parallelism between drum and to prevent lateral forces generated during the tyre axes be 0,17 mm/m maximum under no load, when the measurement from causing the tyre to skid on the absolute values of lateral force offset are made equal, by drum adjusting the fitting angle detectors, in order to correct the errors 4.2.4 4.2.5 caused by axis parallelism, interference and fitting accuracy of the detectors The outer surface of the drum may be used as reference in place of the drum axis Te st rim The rim width shall be equal to that of one of the rims permitted by ISO 4000-1, ISO 4000-2, ISO 4209-1, ISO 4209-2, ISO 4249-1, ISO 4249-2, ISO 4249-3, ISO 5751-1, ISO 5751-2, ISO 6054-1 and ISO 6054-2, and preferably equal to the measuring rim width The specified diameter and the inner contour of the test rim for the measurement of forces and/or geometry shall generally conform to the standard diameter and contour, but some modifications of the contour may be required to facilitate mounting, dismounting and proper seating of the tyre beads for repeatable data Wheels having special contours for bead retention (e.g humps, etc.) shall be avoided The rims shall be sufficiently rigid to ensure that deflection in any direction at the bead seat, when operating under load, is less than 0,125 mm The rims shall have a peak-to-peak run-out at the bead seats, in both radial (bead seat portion) and axial (inner surface of flange) directions, when installed with normal piloting on the apparatus, less than the values given in Table The preferred outer diameters of the drum are: 854 mm for type A, and 600 mm for type B mm NOTE The actual specified outer diameter can be comprised Type A drum < 0,05 between: 830 mm and 000 mm (reference being 854 mm) for type A, Type B drum < 0,1 and 520 mm and 710 mm (reference being 600 mm) for The difference in diameter on the two bead type B seats of the test rim shall not exceed the values If other drum diameters are used, their correlation with the given in Table preferred diameters is to be checked The run-out of the outer surface of the drum, as measured at a reference band, shall be less than mm 0,05 mm when using type A test drum, and Type A drum < 0,1 0,1 mm when using type B test drum The unbalance of the test drum, which is Type B drum < 0,2 critical in case forces are measured at the drum axis, The bead seats shall be turned and polished; shall remain less than the values given in Table the two surfaces shall be symmetrical with respect to the equatorial plane of the wheel within the values given in Table Rotational torque should preferably be applied from the tyre axis; alternatively it may be from the drum axis There should be provisions for both clockwise and counter clockwise directions of rotation The equipment shall be capable of rotating tyres at a rotational frequency of at least 10 r/min and not higher than 250 r/min during the measuring operations Structural resonant frequencies The supporting structure and components of the machine shall be so designed that the influence of natural frequencies, within the measurement frequency range, does not alter the measured parameters more than 10 % External vibrations Sufficient isolation of the equipment shall be provided in order to minimise the influence of the environment on measured parameters 4.3.1 4.1 4.1 4.3.2 4.1 4.3.3 4.1 4.3.4 Te st drum 4.2.1 Tab le E quip me nt Pe ak-to -p e ak run-out 4.3.5 4.2.2 Tab le E quip me nt D iffe re nce in diame te r 4.2.3 4.3.6 Tab le Re sidual unb alance of the te st drum Te st drum Type A Type B S tatic,