BRITISH STANDARD AUTOMOBILE SERIES BS AU 50 1 4 8 1998 ISO 11795 1997 Tyres and wheels — Part 1 Tyres — Section 4 Agricultural tractor and machine tyres — Subsection 4 8 Method of measuring tyre rolli[.]
BRITISH STANDARD AUTOMOBILE SERIES BS AU 50-1 4.8:1 998 ISO 1 795 : 997 Tyres and wheels — Part : Tyres — Section 4: Agricultural tractor and machine tyres — Subsection 4.8 Method of measuring tyre rolling circumference for agricultural tractor drive wheels IC S 65 60 ; 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 4.8:1 998 National foreword This British Standard reproduces verbatim ISO 1 795: 997 and implements it as the UK national standard The UK participation in its preparation was entrusted to Technical Committee AUE/4, Wheels and tyres 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 and 2, an inside back cover 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 Amendments issued since publication This British Standard, having been prepared under the direction of the Engineering Sector Board, was published under the authority of the Standards Board and comes into effect on March 998 © BSI 04- 999 ISBN 80 291 74 X Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy Amd No Date Comments BS AU 0-1 4.8:1 998 Contents Page National foreword Foreword Text of ISO 1 795 © BSI 04- 999 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 4.8:1 998 Contents Page Foreword iii Introduction 1 Scope Normative references Definition Principle Test conditions Tyre installation Test tyres Tyre load and inflation pressure Tyre measurement 5 Test course Weather conditions Test measurement Test speed Method of test Test preparation Test procedure Expression of results Test report Other test conditions Annex A (informative) Bibliography ii Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy Inside back cover © BSI 04- 999 BS AU 0-1 4.8:1 998 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 11795 was prepared by Technical Committee ISO/TC 31, , Subcommittee SC 5, Annex A of this International Standard is for information only Tyres, rim s and v alv es Agricultural tyres and rim s Agricultural machinery, agricultural tractors, drive-wheels, tyres, pneumatic tyres, tests, determination, circumference, dimensional measurements Descriptors: © BSI 04-1999 Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy 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 0-1 4.8:1 998 Introduction Matching front and rear wheels with different tyre sizes on four-wheel drive agricultural tractors requires accurate rolling circumference values The test method to determine rolling circumference outlined below was developed to follow this requirement The values thus obtained are not intended for use as levels of performance or quality The test speed has been set at typical working speed when the four-wheel drive will likely be engaged and the most critical match is required Generally, the four-wheel drive is disengaged at roading speeds Therefore, the determination of rolling circumference is not related to the tyre’s maximum speed, e.g 30 km/h or 40 km/h Nevertheless, other speeds or conditions may be run provided it is clearly documented in the results Scope This International Standard specifies the method for measuring rolling circumference for new tyres, under loaded conditions, made for use on agricultural tractors and machines, and applies to agricultural tractor drive wheel tyres in diagonal and radial construction ISO 8664:1992, Agricultural tractor drive-wheel tyres — Service description (load index — speed symbol) marked tyres Definition For the purposes of this International Standard, the following definition applies 3.1 rolling circumference of tyre distance that the (axle) centre of the tyre moves in one revolution of the tyre under the conditions specified in clause Principle The measurement consists of driving a typical vehicle equipped with the test tyres on the drive axle, on a straight, level road at a constant speed, and counting the number of tyre revolutions (or portions thereof) that occur while traversing a measured distance Test conditions 5.1 Tyre installation Tyre to be tested shall be installed as a single on the drive wheels of a vehicle which shall be Normative references representative of that used with the tyre size being An approved rim in accordance with The following standards contain provisions which, tested ISO 4251-1, ISO 7867-1 or ISO 8664 shall be used through reference in this text, constitute provisions Only the test axle shall be driven of this International Standard At the time of publication, the editions indicated were valid All 5.2 Test tyres standards are subject to revision, and parties to The tyres shall be a matched set of the same size agreements based on this International Standard designation, type, and brand, having inflated, are encouraged to investigate the possibility of unloaded overall diameters within 0,5 % of each applying the most recent editions of the standards other indicated below Members of IEC and ISO maintain registers of currently valid International Standards 5.3 Tyre load and inflation pressure ISO 4251-1:—1) , Tyres (ply rating marked series) The load on each tyre shall be the maximum rated and rims for agricultural tractors and machines — load at 30 km/h, in accordance with ISO 4251-2, Part 1: Tyre designation and dimensions, and ISO 7867-2 or ISO 8664 Tyre inflation pressure approved rim contours shall be the reference inflation pressure that corresponds to the 30 km/h load The tyre shall be ISO 4251-2:—2) , Tyres (ply rating marked series) inflated with air only and rims for agricultural tractors and machines — Part 2: Tyre load ratings 5.4 Tyre measurement ISO 7867-1:1996, Tyres and rims (metric series) for The overall diameter of each tyre shall be measured agricultural tractors and machines — Part 1: Tyre after being inflated for 24 h at ambient temperature designation, dimensions, marking and with no applied load and the inflation pressure tyre/rim coordination specified in 5.3 Inflation pressure shall be checked ISO 7867-2:1996, Tyres and rims (metric series) for and adjusted, if necessary, immediately prior to measurement agricultural tractors and machines — Part 2: Service description and load ratings 1) To be published (Revision of ISO 4251-1:1992) 2) To be published (Revision of ISO 4251-2:1992) © BSI 04-1999 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 4.8:1 998 5 Test course Expression of results 5.8 Test speed Test report The test course for the distance specified in clause The tyre rolling circumference is calculated by shall be a level, straight section of flat, dry road averaging the impulses recorded for the eight surface (asphalt or concrete) observations per test (4 runs × tyres) and then using the following formula: Weather conditions The ambient air temperature for measuring, RC = 1000 ×IS × ipr warm-up, and test shall be between °C and 30 °C; however, an asphaltic surface shall be sufficiently cool that the surface is not tacky The wind speed where: RC = rolling circumference, in millimetres; shall not exceed 15 km/h S = test course length, in metres; Test measurement ipr = number of impulses per tyre revolution; Distance shall be determined by direct measurement or by tyre use of a calibrated fifth I = average number of impulses recorded per wheel Each tyre on test shall be instrumented to test return a minimum of eight impulses per revolution Tyres shall be tested at 10 km/h ± km/h The test report shall include the following information: Method of test a) a reference to this International Standard; 6.1 Test preparation b) the identification of the tested tyre; Immediately prior to testing, the inflation pressure c) the rim width (code); of the loaded tyres shall be adjusted to the inflation d) the tyre overall diameter (mm); pressure specified in at the ambient e) the tyre load (kg); temperature Tyres shall be run for 30 at 25 km/h ± km/h or until inflation pressure f) the inflation pressure (kPa); stabilizes (warm-up) The inflation pressure shall g) the ambient air temperature (°C); not be readjusted afterwards h) the test speed (km/h); 6.2 Test procedure i) the test distance (m); Immediately after the test preparation, run the test j) the test result (rolling circumference in mm); at the speed specified in 5.8 to achieve a minimum k) the date of the test (year-month-day) of 000 impulses over a test course of 100 m minimum while recording the number of impulses Other test conditions for the right wheel and the left wheel separately During the test run, a differential lock shall not be If desired and agreed upon among the interested engaged, acceleration and braking shall be avoided parties, rolling circumference under other and steering input should be kept to minimum Two conditions may be determined by following the runs shall be made in each direction of travel on the above method of test The test report must clearly test course Repeat this procedure if the number of indicate that results were obtained under impulses recorded on any run differs from the others non-standard conditions which shall be defined by more than 0,2 % In the event of stoppage or interruption of the test, repeat the whole test Reprodu ced by I H S u n d er l i cen se wi th BSI - U n trol l ed Copy © BSI 04-1999 BS AU 50-1 4.8:1 998 Annex A (informative) Bibliography Tyres (ply rating marked series) and rims for agricultural tractors and machines — Part 3: Rims IS O 42 - : 99 4, © BS I 4- 99 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 4.8:1 998 ISO 1 795 : 997 BSI — British Standards Institution BS I is the indep endent national b ody res p ons ib le for p rep aring Britis h S tandards It p res ents the UK view on s tandards in E urop e and at the international level It is incorp orated b y Royal C harter Revisions Britis h S tandards are up dated b y amendment or revis ion Us ers of Britis h S tandards should make s ure that they p oss es s the latest amendments or editions It is the constant aim of BS I to imp rove the quality of our p roducts and services We would b e grateful if anyone finding an inaccuracy or amb iguity while us ing this Britis h S tandard would inform the S ecretary of the technical committee res p ons ib le, the identity of which can b e found on the inside front cover Tel: 02 89 96 90 00 Fax: 02 89 96 40 BS I offers memb ers an individual up dating s ervice called PLUS which ens ures that s ub s crib ers automatically receive the lates t editions of s tandards Buying standards O rders for all BS I, international and foreign s tandards p ub lications s hould b e addres s ed to C us tomer S ervices Tel: 899 00 Fax: 899 7001 In res p ons e to orders for international standards , it is BS I p olicy to sup p ly the BS I imp lementation of thos e that have b een p ub lis hed as Britis h S tandards, unless otherwis e requested Information on standards BS I p rovides a wide range of information on national, E urop ean and international standards through its Lib rary and its Technical H elp to E xp orters S ervice Various BS I electronic information s ervices are also availab le which give details on all its p roducts and s ervices C ontact the Information C entre Tel: 02 89 96 71 1 Fax: 02 89 96 048 S ub s crib ing memb ers of BS I are kep t up to date with s tandards develop ments and receive sub s tantial discounts on the p urchase p rice of s tandards For details of thes e and other b enefits contact Memb ership Adminis tration Tel: 02 89 96 70 02 Fax: 02 89 96 00 Copyright C op yright s ub s is ts in all BS I p ub lications BS I als o holds the cop yright, in the UK, of the p ub lications of the internationalstandardization b odies E xcep t as p ermitted under the C op yright, D es igns and Patents Act 988 no extract may b e rep roduced, s tored in a retrieval s ystem or transmitted in any form or b y any means – electronic, p hotocop ying, recording or otherwis e – without p rior written p ermis s ion from BS I This does not p reclude the free us e, in the cours e of imp lementing the standard, of necess ary details such as s ymb ols, and size, typ e or grade designations If thes e details are to b e used for any other p urp os e than imp lementation then the p rior written p ermiss ion of BS I must b e ob tained If p ermis sion is granted, the terms may include royalty p ayments or a licensing agreement D etails and advice can b e ob tained from the C op yright Manager BS I 89 C his wick H igh Road London W4 4AL Reprodu ced by I H S u n d er l i cen se wi th BSI - 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