1、BSI Standards Publication BS ISO 789-3:2015 Agricultural tractors Test procedures Part 3: Turning and clearance diametersBS ISO 789-3:2015 BRITISH STANDARD National foreword This British Standard is the UK implementation of ISO 789-3:2015. It supersedes BS 6347-3:1983 which is withdrawn. The UK part
2、icipation in its preparation was entrusted to Technical Committee AGE/6, Agricultural tractors and forestry machinery. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a con
3、tract. Users are responsible for its correct application. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 79529 9 ICS 65.060.10 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under t
4、he authority of the Standards Policy and Strategy Committee on 30 September 2015. Amendments issued since publication Date Text affectedBS ISO 789-3:2015 ISO 2015 Agricultural tractors Test procedures Part 3: Turning and clearance diameters Tracteurs agricoles Mthodes dessai Partie 3: Diamtres de br
5、aquage et de dgagement INTERNATIONAL STANDARD ISO 789-3 Third edition 2015-09-01 Reference number ISO 789-3:2015(E)BS ISO 789-3:2015ISO 789-3:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no par
6、t of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member bo
7、dy in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.orgBS ISO 789-3:2015ISO 789-3:2015(E)Foreword iv 1 Scope . 1 2 T erms and definitions . 1 3 Apparatus . 5 4 Gen
8、eral requirements . 5 4.1 Test area 5 4.2 Tractor test requirements . 5 4.2.1 Tire and wheel equipment 5 4.2.2 Track (tread) setting . 5 4.2.3 Other settings . 5 5 Procedure. 6 5.1 Right-hand turn, without brakes . 6 5.1.1 Direct measurement . 6 5.1.2 Alternate GPS method . 6 5.2 Left-hand turn, wit
9、hout brakes . 6 5.3 Right-hand turn, with brakes . 7 5.4 Left-hand turn, with brakes . 7 6 Test report 10 Annex A (informative) Specimen test report 11 ISO 2015 All rights reserved iii Contents PageBS ISO 789-3:2015ISO 789-3:2015(E) Foreword ISO (the International Organization for Standardization) i
10、s 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 represe
11、nted 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. The procedures used to develo
12、p this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/I
13、EC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during th
14、e development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the meaning
15、 of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this document is ISO/TC 23, Tr
16、actors and machinery for agriculture and forestry, Subcommittee 2, Common tests. This third edition cancels and replaces the second edition (ISO 789-3:1993), which has been technically revised. ISO 789 consists of the following parts, under the general title Agricultural tractors Test procedures: Pa
17、rt 1: Power tests for power take-off Part 2: Rear three-point linkage lifting capacity Part 3: Turning and clearance diameters Part 4: Measurement of exhaust smoke Part 5: Partial power PT0 Non-mechanically transmitted power Part 6: Centre of gravity Part 7: Axle power determination Part 8: Engine a
18、ir cleaner Part 9: Power tests for drawbar Part 11: Steering capability of wheeled tractors Part 12: Low temperature starting ISO/OECD 789 consists of the following parts, under the general title Agricultural tractors Test procedures: Part 10: Hydraulic power at tractor/implement interfaceiv ISO 201
19、5 All rights reservedBS ISO 789-3:2015INTERNATIONAL ST ANDARD ISO 789-3:2015(E) Agricultural tractors Test procedures Part 3: Turning and clearance diameters 1 Scope This part of ISO 789 specifies a method of determining the turning and clearance diameters of wheeled agricultural tractors. It applie
20、s to wheeled agricultural tractors having at least two axles fitted with pneumatic tyres. 2 T erms a nd definiti ons For the purpose of this document, the following terms and definitions apply. 2.1 agricultural tractor self-propelled agricultural vehicle having at least two axles and wheels, or endl
21、ess tracks, particularly designed to pull agricultural trailers and to pull, push, carry and operate implements used for agricultural work (including forestry work), which may be provided with detachable loading platform Note 1 to entry: The agricultural vehicle has a maximum design speed of not les
22、s than 6 km/h and may be equipped with one or more seats. SOURCE: ISO 12934:2013, 3.1 2.2 track treaddistance at ground level between two vertical planes passing through the centreline of ground contact of the tires parallel to the median plane of the tractor with the wheels in the straight ahead po
23、sition Note 1 to entry: In the case of dual wheels, it is the distance at ground level between two planes passing through the centreline of the dual wheels. Note 2 to entry: See Figure 1. ISO 2015 All rights reserved 1BS ISO 789-3:2015ISO 789-3:2015(E) Figure 1 Track (tread) of the wheeled tractor 2
24、.3 wheelbase horizontal distance between the two vertical planes passing through the rotational centrelines of the wheels, where one plane is for the front wheels and the other for the rear wheels Note 1 to entry: In the case of a tractor equipped with a rear tandem, it is the distance between two v
25、ertical planes passing through the centres of the front wheel and the vertical plane midway between the wheel centres of the two axles of the tandem. Note 2 to entry: See Figure 2.2 ISO 2015 All rights reservedBS ISO 789-3:2015ISO 789-3:2015(E) Figure 2 Wheelbase of the wheeled tractor 2.4 turning d
26、iameter diameter of the circular path described by the centre of tire contact with the surface of the test site of the wheel describing the largest circle when the tractor is executing its sharpest practicable turn under the test conditions described in Clause 5 Note 1 to entry: See Figure 3. 2.5 cl
27、earance diameter diameter of the smallest circle which will enclose the outermost points of projection of the tractor and its equipment while executing its sharpest practicable turn Note 1 to entry: See Figure 3. ISO 2015 All rights reserved 3BS ISO 789-3:2015ISO 789-3:2015(E) F i g u r e 3 T r a c
28、t o r t u r n i n g c o n f i g u r a t i o n s4 ISO 2015 All rights reservedBS ISO 789-3:2015ISO 789-3:2015(E) 3 Apparatus 3.1 Tape measure, of length greater than the turning and clearance diameters to be measured, having a tolerance within 0,5 %. 3.2 Plumb-line, if required, for measuring clearan
29、ce diameters. 3.3 GPS equipment for alternate test, corrected GPS having a measurement accuracy sufficient to produce a linear measurement tolerance of 0,5 %. 4 General requirements 4.1 Test area The test area shall be a compacted or paved dry surface affording good tire adhesion, capable of display
30、ing legible markings, and resistant to defacement by turning machines. The test surface shall be visually flat, with no more than 3 % grade in any direction. In selecting the test area used for GPS measurement, take into consideration the effects of obstructions (e.g. tall buildings, trees, etc.) on
31、 GPS accuracy. 4.2 Tractor test requirements 4.2.1 Tire and wheel equipment The tractor to be tested shall be in its operating state, and the attachments with which it is equipped and their positions shall be noted. The tire, wheel and fender equipment shall be that commonly used in the country for
32、which the tractor is intended, i.e. as specified by the manufacturer, and shall be stated in the test report. Generally, dual wheeled tractors or tractors with added ballast should not be tested unless it is the only specification presented by the manufacturer. Tire pressures, tractor ballast and us
33、e of duals on front or rear shall be recorded in the test report. If steering and/or axle oscillation stops and fenders are part of standard equipment, then these shall be positioned according to the manufacturers instructions. 4.2.2 Track (tread) setting A track (tread) setting of 1 500 mm 25 mm sh
34、all be used. If this is not possible, the nearest setting specified by the manufacturer shall be used. Additional measurement may be made at other track settings specified by the manufacturer. Front and rear track settings shall be as nearly as possible the same and shall be recorded. 4.2.3 Other se
35、ttings 4.2.3.1 Tractors which have all wheels steerable, or which incorporate devices for disconnecting either or both axles, shall be tested in each operating condition in which the tractor is intended to be used. Results shall be recorded for each operating condition. 4.2.3.2 Tractors which have m
36、ore than one powered axle, and which have devices for disconnecting the power to any of the axles, shall be tested in each operating condition in which the tractor is intended to be used. Results shall be recorded for each operating condition. ISO 2015 All rights reserved 5BS ISO 789-3:2015ISO 789-3
37、:2015(E) 5 Procedure 5.1 Right-hand turn, without brakes 5.1.1 Direct measurement 5.1.1.1 Drive the tractor slowly forward while making its sharpest possible right-hand turn, that is, with the steering kept on full right-hand lock, at a speed not exceeding 2 km/h for at least one complete turn, unti
38、l it is established that the minimum turning circle is being described. 5.1.1.2 Continue to drive the tractor slowly forward on the same lock for a further complete turn, at a speed not exceeding 2 km/h. At short regular intervals around the turn, mark on the ground those points coinciding with the
39、centre of the tire-to-ground contact area of the outermost wheel. Make the marks immediately behind this contact area and determine the position of each mark by visually projecting vertically downwards from the centre of the tire tread width at points on the tire circumference situated as close as p
40、ossible to the ground. The marking may be done with or without stopping the tractor. The broken circle formed by the marks on the ground is the turning circle. 5.1.1.3 During the turn described in 5.1.1.2, stop the tractor and drop a plumb-line (3.2) to the ground from the outermost point of the tra
41、ctor (that is from the point of the tractor describing the largest circle). Clearly mark the point on the ground beneath the plumb-line: this point lies on the tractor clearance circle. 5.1.1.4 Measure (3.1) the diameter of the turning circle (see 5.1.1.2) at a minimum of three places spaced approxi
42、mately equally around the circle as shown in Figure 4. Calculate the average value of the diameter measured and report it as the “minimum turning diameter, right-hand, without brakes”. 5.1.1.5 Measure and record the radial distance between the point on the tractor clearance circle (see 5.1.1.3) and
43、the circumference of the tractor turning circle (see 5.1.1.2). Add twice this dimension to the minimum turning diameter and report the result as the “minimum clearance diameter, right-hand, without brakes”. 5.1.2 Alternate GPS method 5.1.2.1 Drive the tractor slowly forward while making its sharpest
44、 possible right-hand turn, that is, with the steering kept on full right-hand lock, at a speed not exceeding 2 km/h for at least one complete turn, until it is established that the minimum turning circle is being described. 5.1.2.2 The diameter of the turning circle shall be calculated as shown in F
45、igure 5 and report it as the “minimum turning diameter, right-hand, without brakes”. 5.1.2.3 Measure and record the lateral and longitudinal position from the GPS receiver (3.3) to the points on the vehicle most likely to produce the largest clearance circle. Calculate as shown in Figure 5 and recor
46、d the largest clearance circle diameter. 5.2 Left-hand turn, without brakes Repeat the procedures described in 5.1 with the tractor driven forward while making its sharpest possible left-hand turn, that is, with the steering kept on full left-hand lock. Report the results as the “minimum turning dia
47、meter, left-hand, without brakes”.6 ISO 2015 All rights reservedBS ISO 789-3:2015ISO 789-3:2015(E) 5.3 Right-hand turn, with brakes Where applicable, repeat the procedure described in 5.1 with the inside non-steered wheel brake applied with a pedal effort sufficient to lock the wheel, subject to a m
48、aximum of 60 daN. Report the results as the “minimum turning/clearance diameter, right-hand, with brakes”. 5.4 Left-hand turn, with brakes Where applicable, repeat the procedure described in 5.3 with the tractor making its sharpest possible left-hand turn, that is, with the steering kept on full lef
49、t-hand lock. Report the results as the “minimum turning/clearance diameter, left-hand, with brakes”. Figure 4 Calculation of the diameters from measurements between three approximately equally spaced circumference points ISO 2015 All rights reserved 7BS ISO 789-3:2015ISO 789-3:2015(E) Figure 5 Geometric for calculation of the turning diameter
