1、BRITISH STANDARD BS 6911-12: 1998 ISO 7457:1997 Testing earth-moving machinery Part 12: Determination of turning dimensions of wheeled machines ICS 53.100BS6911-12:1998 This British Standard, having been prepared under the directionof the Sector Board forBuilding and Civil Engineering, was published
2、 underthe authority of the Standards Board and comes intoeffect on 15 March 1998 BSI 05-1999 ISBN 0 580 29423 4 National foreword This British Standard reproduces verbatim ISO 7457:1997 and implements it as the UK national standard. It supersedes BS 6486:1984 which is withdrawn. The UK participation
3、 in its preparation was entrusted by Technical Committee B/513, Construction equipment and plant, and site safety, to Subcommittee B/513/1, Earth-moving machinery (international), which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European
4、 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 subcommittee can be obtained on request to its secretary. Cr
5、oss-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 Electro
6、nic 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 docu
7、ment comprises a front cover, an inside front cover, pages i and ii, theISO title page, page ii, pages 1 to 8 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. Amend
8、ments issued since publication Amd. No. Date CommentsBS6911-12:1998 BSI 05-1999 i Contents Page National foreword Inside front cover Foreword ii 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Test area 1 5 Test equipment 1 6 Preparation for test 2 7 Test procedure 5 8 Additional optional test
9、procedure for machines whose left- and right-hand brakes on the non-steered wheels can be applied separately 6 9 Test results 6 Figure 1 Turning and related diameters 2 Figure 2 Tyre clearance diameter 4 Figure 3 Non-stop 180 turn width 7 Figure 4 Calculation of diameters from measurements between t
10、hree approximately equally spaced circumference points 8ii blankBS6911-12:1998 ii BSI 05-1999 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 carrie
11、d 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. IS
12、O 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 appr
13、oval by at least 75% of the member bodies casting a vote. International Standard ISO 7457 was prepared by Technical Committee ISO/TC127, Earth-moving machinery, Subcommittee SC 1, Test methods relating to machine performance. This second edition cancels and replaces the first edition (ISO 7457:1983)
14、, which has been technically revised. Descriptors: Earth-moving equipment, self-propelled machines, turning circle, tests, determination, turning radius, dimensional measurements.BS6911-12:1998 BSI 05-1999 1 1 Scope This International Standard specifies methods for determining the turning radius, tu
15、rning diameter, machine clearance diameter, and inside and outside tyre clearance diameters, described in the horizontal plan by a wheeled earth-moving machine with its equipment and attachments when executing a turn. This International Standard is applicable to all types of steerable wheeled earth-
16、moving machinery. It is applicable irrespective of the type of steering used. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid.
17、All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standa
18、rds. ISO 5010:1992, Earth-moving machinery Rubber-tyred machines Steering requirements. ISO 6165:1997, Earth-moving machinery Basic types Vocabulary. ISO 9248:1992, Earth-moving machinery Units for dimensions, performance and capacities, and their measurement accuracies. 3 Definitions For the purpos
19、es of this International Standard, the definitions given in ISO 6165 and the following apply. 3.1 turning centre point about which all turns of constant radius are made (See Figure 1.) 3.2 turning diameter diameter of the circular path described by the centre of tyre contact with the surface of the
20、test site of the wheel describing the largest circle when the machine is executing its sharpest practicable turn under the test conditions described in clause 7, or by calculation for skid steer loaders (See Figure 1.) 3.3 turning radius half the turning diameter (as defined in 3.2) (See Figure 1.)
21、3.4 machine clearance diameter diameter of the smallest circle which will enclose the outermost points of projection of the machine and its equipment and attachments when it executes its sharpest practical turn, under the conditions described in clause 7, or by calculation for skid steer loaders (Se
22、e Figure 1.) NOTEAs the machine clearance diameter is affected by the type of equipment and attachments fitted, the latter should be stated in the test report. 3.5 outer and inner tyre clearance diameter diameter of the circular path described by the outermost point of the loaded (lower) section of
23、the tyre located on the vertical diameter of the outermost wheel and also that of the innermost point of the innermost wheel when the machine is executing its sharpest practical turn under the conditions described in clause 7 (See Figure 1 and Figure 2.) see clause 6 for the state of loading of the
24、machine 3.6 non-stop 180 turn width minimum road width required for the tyre paths of the machine as it makes a 180 turn without stopping (See Figure 3.) 4 Test area The test area shall be a compacted or paved surface affording good tyre adhesion, capable of displaying legible markings and resistant
25、 to defacement by turning machines. The test surface shall be visually flat, with no more than 3% grade in any direction. The test area shall be large enough to accommodate the test machine as it negotiates the appropriate tests. 5 Test equipment The following equipment or its equivalent shall be pr
26、ovided. 5.1 Steel tape, readable to 1 cm and of greater length than the diameter (or radii) to be measured. 5.2 Plumb line, as required in the measurement of clearance diameter (or radii). 5.3 Apparatus for the measurement of pedal effort, as required for the execution of the test.BS6911-12:1998 2 B
27、SI 05-1999 6 Preparation for test 6.1 The track of machines having adjustable track axles shall be measured and recorded. The tyre pressures shall be adjusted to those recommended by the manufacturer of the machine. If the manufacturer specifies various pressures or ballast according to ground condi
28、tions then those specified for a hard surface shall be used. The tyre sizes and pressures used shall be recorded. 6.2 The machine to be tested shall be in its operating condition, and the equipment and the attachments with which it is equipped and their positions shall be noted. 6.3 Movable equipmen
29、t shall be in its recommended transport position. 6.4 Load-carrying equipment shall be laden or empty as specified in 6.4.1 to 6.4.3 (see ISO 5010). 6.4.1 Tractor-scrapers and dumpers shall be at the manufacturers rated maximum gross mass and axle distribution, including the mass of the heaviest com
30、bination of equipment and attachments approved by the manufacturer, an operator of 75 kg and a full fuel tank. 6.4.2 Wheel loaders, wheel tractors, excavators and graders shall be at the manufacturers empty machine mass, including the mass of the heaviest combination of equipment and attachments app
31、roved by the manufacturer which produce the greatest load on the steered axle(s), an operator of75 kg and a full fuel tank. 6.4.3 All component parameters related to steering capability shall be within the manufacturers specifications; i.e. tyre size and pressure, hydraulic fluid pressure and flow,
32、warning device actuation point, etc. Figure 1 Turning and related diametersBS6911-12:1998 BSI 05-1999 3 Figure 1 Turning and related diameters (concluded)BS6911-12:1998 4 BSI 05-1999 Figure 2 Tyre clearance diameterBS6911-12:1998 BSI 05-1999 5 7 Test procedure See ISO 9248 for units and tolerances.
33、7.1 Right turn: Wheeled and articulated steer 7.1.1 Drive the machine forwards, at as low a speed as possible, on full right lock, that is, with the steering control element (e.g. steering wheel) turned to the right to its fullest extent, until the minimum diameter is being described. 7.1.2 Then con
34、tinue to drive the machine forward, at as low a speed as possible, with the position of the steering control element unchanged, for a further complete turn but stopping at regular short intervals. At appropriate stops, make projections to the surface of the test site with the plumb line and mark the
35、 test surface appropriately. The projections shall be made, as required, from the following. a) The outermost point of the loaded (lower) section of the tyre on the vertical diameter of the outermost wheel: this point shall be used to determine the outer tyre clearance diameter. NOTEShould the wheel
36、 at which the measurement is being made lean outwards to a significant extent it may be advisable to determine, in addition, the outer tyre clearance diameter or radius by projecting down from the upper section of the tyre on the vertical diameter of the outermost wheel. b) The innermost point of th
37、e loaded (lower) section of the tyre on the vertical diameter of the innermost wheel: this point shall be used to determine the inner tyre clearance diameter. NOTEAny inward wheel lean should again be taken into account. c) The outermost point, that is, the point describing the largest circle of the
38、 machine and its equipment: this point shall be used to determine the machine clearance diameter. 7.1.3 Measure the outer tyre clearance diameter at not less than three points spaced approximately equally around the circle. The average of the three or more measurements shall be calculated and noted,
39、 and the width of the outermost tyre, measured across the loaded section of the tyre shall be recorded as the turning diameter right. Alternatively and optionally the resulting dimension may be halved and recorded as turning radius right. 7.1.4 Measure the inner tyre clearance diameter at not less t
40、han three points spaced approximately equally around the circle. The average of the three or more measurements shall be calculated and noted. 7.1.5 Measure the diameter of the machine clearance circle at not less than three points spaced approximately equally around the circle. The average of the th
41、ree or more measurements shall be calculated and noted. The machine clearance diameter may also be determined by adding twice the radial distance between the point projected for the machine clearance diameter and the outer tyre clearance circle. 7.1.6 As an alternative to the above method of measure
42、ment of the diameters, the latter may be determined by calculation, using the distances between three approximately equally spaced points; see Figure 4, using the relationship shown. 7.1.7 For the right non-stop 180 turn width (see Figure 3), proceed as follows. a) The machine shall be in a non-arti
43、culated or non-steered position. Mark a line to the left of the machine parallel to the centreline of the machine. b) Turn the steering wheel to the full right turn angle while the machine is in a stationary position. Then drive the machine forward while still steering full right. A 270 turn shall b
44、e completed, while stopping at regular intervals to mark the tyre clearance circle as in 7.1.2. At the beginning of the turn, the tyre clearance circle shall be marked for whichever tyre is closest to the line described in a). c) Measure the perpendicular distances from the line described in a) to t
45、he near side and the far side of the tyre clearance circle. The difference between the two measurements shall be the right non-stop 180 turn width. 7.1.8 Any other methods for determining the turning diameters which give equal accuracy may be employed. 7.1.9 Each test shall be conducted three times
46、and the average of the turning dimensions obtained shall be recorded in the test results. 7.2 Left turn: Wheeled and articulated steer Repeat the procedure described in 7.1 but with the machine driven on full left lock instead of on full right lock and record the results as left turn results instead
47、 of right turn. 7.3 Skid steer Turning centre, machine clearance diameter and outer tyre clearance diameter are determined by calculation from machine drawings (see Figure 1). Definitions 3.5 and 3.6 are not applicable.BS6911-12:1998 6 BSI 05-1999 8 Additional optional test procedure for machines wh
48、ose left- and right-hand brakes on the non-steered wheels can be applied separately Repeat the test procedure described in clause7 with the inside non-steered wheel brake applied with a pedal effort of 450 N or with the effort necessary to lock the wheel if this is less than 450 N. The results obtai
49、ned shall be reported as “with brakes”. The results from the test procedure described in clause 7 shall be reported as “without brakes”. 9 Test results The following information shall be recorded in the test report: a) name of manufacturer; b) type of machine; c) model, serial number; d) equipment fitted and its position; e) tyre sizes: f) tyre pressure, in kilopascals: g) the track width, in metres, of all axles; h) outer tyre clearance diameter, in metres: 1) right turn without brakes; 2) left turn without brakes; and, where appl
