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1、BRITISH STANDARD BS ISO 13772:1997 Forestry machinery Portable chainsaws Non-manually actuated chain brake performance ICS 65.060.80 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:24:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 13772:1997 This British Standard, having been prepare
2、d under the direction of the Engineering Sector Board, was published under the authority of the Standards Board and comes into effect on 15 December 1997 BSI 04-2000 ISBN 0 580 28866 8 National foreword This British Standard reproduces verbatim ISO 13772:1997 and implements it as the UK national sta
3、ndard. The UK participation in its preparation was entrusted to Technical Committee AGE/29, Forestry machinery, 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 cha
4、nge, 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 E
5、uropean 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 n
6、ecessary 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, th
7、e ISO title page, pages ii to iv, pages 1 to 5 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 Amd. No.DateComments Licensed Co
8、py: sheffieldun sheffieldun, na, Mon Nov 27 03:24:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 13772:1997 BSI 04-2000i Contents Page National forewordInside front cover Forewordiii Text of ISO 137721 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:24:38 GMT+00:00 2006, Uncontrolled
9、 Copy, (c) BSI ii blank Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:24:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:24:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 13772:1997 ii BSI 04-2000 Contents Page Forewordiii Int
10、roduction1 1Scope1 2Normative references1 3Definitions1 4Performance requirements1 5Principle1 6Test equipment1 6.1Acceleration measuring equipment1 6.2Test rig2 7Preparation2 8Test Procedure4 9Test report4 Annex A (normative) Frequency range and low-pass filter characteristics5 Figure 1 Threshold l
11、evel for actuation of non-manually actuated chain brakes2 Figure 2 Test rig with mounted chain saw3 Figure A.1 Tolerance boundaries for the filter frequency response5 Table 1 Corresponding values of engine displacement and length of guide bar1 Table A.1 Filter frequency response boundaries5 Descript
12、ors: Forestry, forest equipment, portable equipment, saws, chain saws, brakes, specifications, performance, safety requirements, tests, braking tests. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:24:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 13772:1997 BSI 04-2000iii Foreword
13、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
14、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 elect
15、rotechnical 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 13772 was prepare
16、d by Technical Committee ISO/TC 23, Tractors and machinery for agriculture and forestry, Subcommittee SC 17, Manually portable forest machinery. Annex A forms an integral part of this International Standard. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:24:38 GMT+00:00 2006, Uncontrolled
17、 Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:24:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 13772:1997 BSI 04-20001 Introduction This International Standard was developed in response to worldwide demand for a test method and criteria for acceptable initi
18、ation of non-manually actuated chain brakes. 1 Scope This International Standard specifies a method to check the function of the non-manually actuated chain brake on portable hand-held combustion engine driven chain-saws and gives performance requirements. 2 Normative references The following standa
19、rds contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to i
20、nvestigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 5347-0:1987, Methods for the calibration of vibration and shock pick-ups Part 0: Basic concepts. ISO 5348:, Mech
21、anical vibration and shock Mechanical mounting of accelerometers1). ISO 6531:1982, Machinery for forestry Portable chain saws Vocabulary. 3 Definitions For the purposes of this International Standard, the definitions given in ISO 6531 and the following definition apply. 3.1 non-manually actuated cha
22、in brake brake which is actuated irrespective of operator intervention when a kick-back occurs 4 Performance requirements The non-manually actuated chain brake function shall be checked on a normal production saw equipped with a specified guide bar. If no specification is given for the guide bar, th
23、e bar length shall be in accordance with Table 1 and without a sprocket. The chain-saw shall be in a new and clean condition. Deviations shall be reported in the test report. Table 1 Corresponding values of engine displacement and length of guide bar The chain brake shall be considered to have an ac
24、ceptable non-manually actuated function if each of the horizontal and vertical acceleration levels, ax and ay, at which the chain brake actuates (see clause 8) are below the appropriate limit line as given in Figure 1. 5 Principle The chain-saw shall be mounted on a test rig as shown in Figure 2. Th
25、e drop mass falls from a defined height on the rocker and accelerates the chain-saw on the opposite side. The drop height shall be increased until an actuation of the non-manually actuated chain brake occurs. The chain-saw is suspended in the test rig from cords at the guide bar and at the rear hand
26、le behind the throttle trigger in such a way that the chain saw can conduct an unhindered rotary and translatory motion after the impact pulse has been introduced into the bar tip. The bar tip acceleration needed to actuate the brake is determined and used as a value to evaluate the brake function.
27、6 Test equipment 6.1 Acceleration measuring equipment The total mass of the accelerometer(s) shall be as low as possible and may not in any case exceed 50 g including the mounting but excluding the cables. The signal from the accelerometer(s) shall be processed by a low-pass filter with characterist
28、ics as showing in Annex A. Care shall be taken when mounting the accelerometer so that the transfer function is flat up to 300 Hz for both measuring directions. For general considerations concerning accelerometer mounting, see ISO 5348. NOTEThe transfer function can be considered flat if an addition
29、 of mass to the accelerometer equal to that of the accelerometer does not have any significant influence on ax and ay. (This additional mass should be placed between the accelerometer and its mounting, if the mass is of metal, or around the accelerometer if the mass consists of materials such as cla
30、y or wax.) 1) To be published. (Revision of ISO 5348:1987) Engine displacement cm3 Effective length of guide bar L m 0 to 44 45 to 69 70 to 89 W 90 0,25 to 0,35 0,30 to 0,40 0,40 to 0,50 0,50 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:24:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI B
31、S ISO 13772:1997 2 BSI 04-2000 The accuracy of the measuring equipment, excluding accelerometer mounting and the filter shall be 5 % of registered value in the frequency range 0 Hz to 300 Hz. See ISO 5347-0 for calibration methods. 6.2 Test rig The design principles of the test rig shall be as shown
32、 in Figure 2. The test rig cord length, as well as the longitudinal and lateral positioning of the pivoting pulley for the cord, shall be adjustable. The test rig rocker shall be made of rectangular hollow steel section, 80 mm 40 mm 4 mm. The drop weight device shall have a drop mass of 15 000 g 20
33、g. It shall be possible to select drop heights in steps of 10 mm or less, at least between a drop height of 200 mm to 1 400 mm. The accuracy of the drop height shall be 2 mm. The spring in the drop weight device shall have a characteristic of 640 N/mm 20 N/mm for an increasing spring load. NOTEThe s
34、pecified spring rate can be achieved by 7 leaf springs (45 mm 22,4 mm 1,75 mm) with an adverse orientation to each other. The spring defines the length and the characteristic of the impulse. The pulse of the simulated kickback will then be approximately 10 ms. 7 Preparation Check that the chain-saw
35、is in accordance with the product specification. If no guide bar length has been specified, choose one according to Table 1. Precondition the saw by actuating the non-manually actuated chain brake 10 times, for example by dropping the saw, while holding the rear handle, so the bar tip hits a rigid,
36、wooden surface. Then adjust the chain tension adjuster to its mid-position and move the guide bar to its uppermost position, at the top of the bar, in order to eliminate the play, and fasten the guide bar on the saw. The saw chain shall not be installed and the tanks shall be empty. Figure 1 Thresho
37、ld level for actuation of non-manually actuated chain brakes Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:24:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 13772:1997 BSI 04-20003 Figure 2 Test rig with mounted chain saw Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:24
38、:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 13772:1997 4 BSI 04-2000 Attach the accelerometer(s) to measure the horizontal and vertical accelerations, ax and ay respectively. The centrelines of the active direction of the accelerometer shall intersect the guide bar tip radius centre point
39、within 2 mm. For the other two orthogonal directions the centre of gravity of the respective accelerometers shall be within 10 mm from the guide bar tip radius centre point. The orientation of the accelerometer(s) shall be as shown in Figure 2. The chain-saw shall be mounted on the test rig by the c
40、ord at attachment point A and B (see Figure 2), so that the longitudinal centreline for the guide bar is inclined downwards at 30 2 and is parallel to the longitudinal plane of the test rig rocker. The attachment point A shall be on the grip area of the rear handle. The attachment point B shall be l
41、aterally adjusted so that the guide bar plane is vertical within 3. Attachment point B shall be chosen high enough to ensure stable suspension of the chain-saw, i.e. the straight line between point A and B shall pass above the centre of gravity of the chain-saw. The attachment point B shall be along
42、 the longitudinal centre plane of the guide bar chosen so that the guide bar tip will be lifted off the aluminium spacer when a normal force, Fn, of 2 N 0,4 N is applied, see Figure 2. The angular support shall be adjusted so that the line perpendicular to the test rig rocker longitudinal centreline
43、 through the contact point between the rocker spacer and the guide bar tip will pass through the guide bar tip radius centre point within 1 mm. The pulley shall be longitudinally positioned so that the guide bar tip will be pulled off the angular support when a tangential force, Ft, of 2 N 0,4 N is
44、applied, see Figure 2. 8 Test procedure The non-manually actuated chain brake shall be actuated by the acceleration which will occur after the drop mass has been released. It is recommended to start at a drop height of 200 mm and to increase the height in steps of 100 mm to initiate actuation. After
45、 the first actuation, decrease the drop height again in steps of 20 mm to a point where the brake no longer actuates automatically. Raise the drop height by 10 mm and repeat the test five times under the same conditions. If the brake is actuated five times, the conditions established shall be used t
46、o measure the accelerations, ax and ay, see Figure 1. If the brake is not actuated five times, raise the drop height by 10 mm and repeat the test five times. The procedure shall be repeated, if necessary, until the drop height at which the brake is actuated for all five tests is attained. When the l
47、owest drop height has been defined, measure and register the values of the bar tip accelerations, ax and ay, five times under the same conditions and calculate the average values of the accelerations. 9 Test report The test report shall include the following information: a) reference to this Interna
48、tional Standard; b) date and place of measurement; c) name of the operator; d) description of the chain-saw: manufacturer; type, model and serial number; type and length of guide bar; mass of the chain-saw as measured (with bar, without chain, with tanks empty), in kilograms; release force of the ch
49、ain brake (see ISO 6535), in newtons; e) description of the measuring equipment; f) description of accelerometer mounting; g) values of the recorded bar tip accelerations, ax and ay, expressed in metres per second squared, and the calculated average accelerations, ax,av and ay,av, respectively, at the chain brake actuation limit. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 03:24:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 13772:1997 BSI 04-20005 Annex A (normative) Frequency rang
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