BS ISO 9518-1998 Forestry machinery - Portable chain-saws - Kickback test《林业用机械 便携式链锯 逆转试验》.pdf

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1、BRITISH STANDARD BS ISO 9518:1998 Forestry machinery Portable chain-saws Kickback test ICS 65.060.80BS ISO 9518:1998 This British Standard, having been prepared under the directionof the Engineering Sector Committee, was publishedunder the authority ofthe Standards Committee and comes into effect on

2、 15 December 1998 BSI 06-1999 ISBN 0 580 30898 7 National foreword This British Standard reproduces verbatim ISO9518:1998 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee AGE/29, Agricultural and forestry machinery, which has

3、 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 t

4、he 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

5、“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 w

6、ith 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, theISOtitle page, pagesii toiv, pages1to38 and a back cover. This standard has been updated (see copyright date) and may ha

7、ve had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBS ISO 9518:1998 BSI 06-1999 i Contents Page National foreword Inside front cover Foreword iii Text of ISO 9518 1ii blankBSISO9518:1998 i

8、i BSI 06-1999 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Test method 2 4.1 Principle 2 4.2 Materials 2 4.3 Apparatus 2 4.4 Preparation 3 4.4.1 Physical measurements 3 4.4.2 Saw chain preparation 3 4.4.3 Chain-saw preparation 3 4.4.4 Kickback machin

9、e preparation 3 4.4.5 Chain-saw installation and alignment 3 4.4.6 Saw/clamp/cradle assembly balance 4 4.4.7 Friction measurements 4 4.4.8 Restraining systems alignment 4 4.4.9 Impact velocity adjustment 4 4.5 Test requirements and procedures 4 4.5.1 Test requirements 4 4.5.2 Kickback testing 5 4.5.

10、3 Kickback energy determination 5 4.5.4 Chain brake energy determination 6 4.5.5 Chain brake actuation angle measurement 7 4.5.6 Chain brake stopping time measurement 7 4.6 Kickback angle computation 7 4.6.1 Input data 7 4.6.2 BASIC computer program 7 4.6.3 Results 8 4.7 Test report 8 Annex A (norma

11、tive) Computer program flowchart 18 Annex B (informative) Basic computer program 29 Figure 1 Computed kickback angle 8 Figure 2 Coordinate measurements 9 Figure 3 Saw chain tension adjustment 10 Figure 4 Installation of saw/clamp/cradle assembly 11 Figure 5 Adjustment of rack/horizontal restraining

12、system 12 Figure 6 Adjustment of rotary restraining system 13 Figure 7 Adjustment of chain brake actuator 14 Figure 8 Specimen exit angle measurement 15 Figure 9 Kickback test record 16 Figure 10 Chain-saw installation and balancing test record 17 Table 1 Test sequence 5 Table 2 Optional test sequen

13、ce 5 Descriptors: Forest equipment, portable equipment, mechanically-operated devices, saws, chain saws, tests, impact tests.BSISO9518:1998 BSI 06-1999 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). Th

14、e 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-gov

15、ernmental, 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

16、voting. Publication as an International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO9518 was prepared by Technical Committee ISO/TC23, Tractors and machinery for agriculture and forestry, Subcommittee SC17, Manually portable forest machine

17、ry. This second edition cancels and replaces the first edition (ISO9518:1992), which has been technically revised, mainly to extend it to include chain-saws with an engine capacity of80cm 3 . Annex A forms an integral part of this International Standard. Annex B is for information only.iv blankBS IS

18、O 9518:1998 BSI 06-1999 1 Introduction The movement of a chain-saw during kickback can be simulated by a mathematical model. Through application of engineering principles, vertical, horizontal and rotational components of the chain-saws movement are predicted. The model is presented in this Internat

19、ional Standard in the form of a computer program which predicts the peak position of the chain-saw, upward and backward towards the user. This is called the “computed kickback angle” and is illustrated in Figure 1. The computer program uses standard engineering force-motion equations to predict the

20、path of the saw based on kickback energy, physical characteristics of the chain-saw and simulated operator reaction forces. User reaction forces were determined through analysis of high-speed motion pictures of actual hand-held kickbacks. 1) Input data for the computer program is obtained from physi

21、cal measurements and from kickback energy tests performed on a completely assembled chain-saw including powerhead, guide bar and saw chain. Kickback energy of a chain-saw is measured on a apparatus (called the kickback machine) developed specifically for this purpose. Kickbacks are generated by deli

22、vering the flat surface of a fibreboard test specimen into contact with the bar tip under controlled conditions. This apparatus and standardized specimen have been found to yield a realistic measurement of kickback energy of any specific saw/bar/chain combination. The test procedure requires testing

23、 over a range of conditions to ensure that peak kickback energy for the particular saw/bar/chain combination on test is determined. When the rotating parts of a chain-saw are stopped by a chain brake, a moment is generated that tends to reduce the kickback angle. The procedure accounts for this effe

24、ct. Annex A is a flow diagram of the computer program used to determine the computed kickback angle. Annex B contains a BASIC language program (complete with examples) to make these computations 1 Scope This International Standard specifies the methodology for determining the kickback potential of a

25、 gasoline-powered chain-saw, complete with guide bar and saw chain. This International Standard has been demonstrated to be an accurate method of measurement for evaluating computed kickback angles and energy associated with chain-saw kickback for chain-saws with engine capacity up to80cm 3 . It is

26、not intended to evaluate chain-saws with an engine capacity of above80cm 3 . Furthermore, because of physical size limitations of the kickback machine, testing of units with guide bar cutting length in excess of63cm is not recommended. NOTEAlthough this International Standard is applicable to gasoli

27、ne-powered chain-saws, the kickback machine and test procedure ought to be also suitable for testing of electric powered chain-saws. To aid in application of this test method to electric powered units, some instructions are included in this document that relate specifically to electric chain-saws. 2

28、 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. All standards are subject to revision and parties to agreements based on this I

29、nternational 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 Standards. ISO 6535:1991, Portable chain-saws Chain brake performance. BOM-0100, Kickb

30、ack machine Bill of materials 2) . 3 Definitions For the purposes of this International Standard, the following definitions apply. 3.1 bar tip guard shield that prevents contact with the chain at the tip of the guide bar and which may be removable and replaceable 3.2 chain brake lever device, usuall

31、y the front hand guard, used to activate the chain brake 1) For additional details see Overview of the KICKBACK Computer Program Contents and Development, available from the Portable Power Equipment Manufacturers Association, 4720 Montgomery Lane, Suite514, Bethesda, MD20814, USA. 2) The bill of mat

32、erials and engineering drawings describing the kickback machine are available from the Portable Power Equipment Manufacturers Association, 4340 East-West Highway, Suite912, MD20814, USA.BS ISO 9518:1998 2 BSI 06-1999 3.3 computed kickback angle angle used as a measure of the reaction of a hand-held

33、chain-saw, backward and upward toward the user, when subjected to a rotational kickback under simulated conditions see Figure 1 3.4 contact angle angle between the surface of the test specimen and a perpendicular to the guide bar centreline 3.5 data set group of data points, all taken at the same te

34、st conditions 3.6 horizontal system portion of the kickback machine used to measure the horizontal energy of the kickback reaction 3.7 impact test sequence involving releasing the specimen into contact with the moving saw chain at the guide bar tip to create a simulated kickback reaction 3.8 kickbac

35、k rotational kickback rapid upward and backward motion of the saw which can occur when the moving saw chain near the upper portion of the tip of the guide bar contacts an object such as a log or branch 3.9 kickback machine apparatus used to measure the energy generated by a chain-saw kickback under

36、controlled conditions 3.10 power head chain-saw without the guide bar and chain 3.11 rotary system portion of the kickback machine used to measure the rotary energy of the kickback reaction 3.12 specimen test specimen block of medium density fibreboard used as an object for the saw chain to engage i

37、n a simulate kickback 4 Test method 4.1 Principle The flat surface of a wood-like specimen is thrust into contact with the moving saw chain at the tip of a chain-saw guide bar, in order to produce a simulated kickback reaction. This takes place under controlled conditions in apparatus designed to me

38、asure the magnitude of rotary and horizontal energies generated during the resulting kickback reaction. A step-by-step search, covering a range of critical test conditions, determines the peak energy values to be used in computing kickback angle. This peak value is intended to simulate the most seve

39、re conditions reasonably expected to be encountered by typical users. Since there may be some variability, several impacts are made under each set of conditions and the results averaged. NOTETest parameters such as approach speed, engine speed, shape and type of test materials have been established

40、to permit consistent evaluation of a wide range of cutting attachment and type of power head and to simulate kickback situations found in actual practice. Other test parameters will lead to different computed kickback angles. 4.2 Materials Test samples, consisting of medium-density fibreboard (densi

41、ty range732kg/m 3 32kg/m 3 ). Samples shall be oriented with the rough side (end grain) facing the bar tip. Standard test samples are38mm 38mm 250mm. At the discretion of the test laboratory, specimens with depth (measured perpendicular to the test face) up to76mm may be used. NOTEBecause kickback e

42、nergy measurements are sensitive to the consistency of the fibreboard, careful control of these specimens is essential. In order for test results to be reproducible over time and for comparisons with results from other laboratories, the test specimens need to be calibrated against “known” specimens.

43、 Calibration requires kickback testing with samples from batch lots using a “standard” saw/chain/bar combination for which the kickback energies have been established. A calibration factor can then be applied to the energy values before they are used in the computer model. 4.3 Apparatus 4.3.1 Chain-

44、saw kickback machine BOM-0100 for energy level measurements. (Seeclause2.) 4.3.2 Engine speed indicator with a rotational frequency reading accuracy of 1,5% of the measured value. 4.3.3 Carriage velocity timing device, including probes with an accuracy of 1ms and a holding circuit to prevent unwante

45、d re-triggering. 4.3.4 Chain brake timing device, including probes having an accuracy of 3ms. 4.3.5 Chain brake testing apparatus in accordance with ISO6535. 4.3.6 Computer and kickback program to compute the kickback angle.BS ISO 9518:1998 BSI 06-1999 3 4.4 Preparation NOTERecord all measurements o

46、n the kickback test record (seeFigure 9 andFigure 10). 4.4.1 Physical measurements 4.4.1.1 The following physical measurements are to be made with the guide bar and saw chain attached in proper working position and with oil and fuel tanks full. The saw chain shall be prepared in accordance with4.4.2

47、 prior to taking measurements. 4.4.1.2 Chain-saw mass in kilograms. An accuracy of 50g is acceptable for this measurement. 4.4.1.3 Location of axis of rotation, through the centre of gravity, perpendicular to the plane of the guide bar. It is to be marked on the saw body. An accuracy of 6mm is accep

48、table for this measurement. 4.4.1.4 Chain-saw moment of inertia about an axis through the centre of gravity and perpendicular to the plane of the guide bar, in kilograms metre squared. 4.4.1.5 Chain-saw tab tip, front handle and rear handle locations relative to the centre of gravity expressedas x,

49、y coordinates, in millimetres. An accuracy of 3mm is acceptable for these measurements(see Figure 2). 4.4.2 Saw chain preparation 4.4.2.1 The saw chain shall be new. 4.4.2.2 Saw chain tension shall be set in accordance with Figure 3. The chain should move freely on the bar. 4.4.3 Chain-saw preparation 4.4.3.1 The chain-saw shall be in functionally new condition. 4.4.3.2 The saw shall be run-in according to the manufacturers recommendations. 4.4.3.3 If the saw is equipped with a removable bar tip guard, remove the bar tip