1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 11837:2011Machinery for forestry Sawchain shot guarding systems Test method and performancecriteriaBS ISO 11837:2011 BRITISH STANDARDNational forewordThis British Standard
2、 is the UK implementation of ISO 11837:2011.The UK participation in its preparation was entrusted to TechnicalCommittee AGE/29, Forestry machinery.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the nec
3、essaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 66309 3ICS 65.060.80Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Com
4、mittee on 31 July 2011.Amendments issued since publicationDate Text affectedBS ISO 11837:2011Machinery for forestry Saw chain shot guarding systems Test method and performance criteriaMatriel forestier Systme de protection contre ljection dlments de chanes de scie Mthode dessai et critres de perform
5、ance ISO 2011Reference numberISO 11837:2011(E)First edition2011-07-15ISO11837INTERNATIONAL STANDARDBS ISO 11837:2011ISO 11837:2011(E)COPYRIGHT PROTECTED DOCUMENT ISO 2011All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any m
6、eans, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrigh
7、tiso.orgWeb www.iso.orgPublished in Switzerlandii ISO 2011 All rights reservedBS ISO 11837:2011ISO 11837:2011(E)Contents PageForeword ivIntroduction v1 Scope 12 Terms and definitions .13 Test equipment .23.1 Test apparatus 23.2 Drive unit .23.3 Saw chain speed control .23.4 Drive shaft speed measure
8、ment .23.5 Saw chain tensioning system 23.6 Saw chain lubrication system 23.7 Saw chain stopping device .23.8 Protective cover .24 Cutting attachment24.1 Guide bar .24.2 Drive sprocket 34.3 Saw chain 35 Reference panels .36 Pre-calibration of test arrangement .37 Assembly of saw chain shot guarding
9、system in test rig 47.1 Position 47.2 Alternative positions 47.3 Obstacles .58 Test procedure .59 Total number of test runs 610 Performance requirements .611 Test report .6Annex A (normative) Saw chain stopping device 8 ISO 2011 All rights reserved iiiBS ISO 11837:2011ForewordISO (the International
10、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 esta
11、blished 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 standardiza
12、tion.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
13、 Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.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 pat
14、ent rights.ISO 11837 was prepared by Technical Committee ISO/TC 23, Tractors and machinery for agriculture and forestry, Subcommittee SC 15, Machinery for forestry.ISO 11837:2011(E)iv ISO 2011 All rights reservedBS ISO 11837:2011IntroductionOn the basis of a risk analysis, the types of saw chain bre
15、akage can be determined and a saw chain shot guarding system selected that protects against these risks.Harvester heads and grip saws need an effective saw chain shot guarding system. However, no such system can give 100 % safety protection against a saw chain shot. This International Standard speci
16、fies a method for evaluating the performance of a guarding system for the prevention of saw chain shot from behind the drive sprocket and upwards, relative to the direction of movement of the saw chain.The test apparatus specified in this International Standard is designed to simulate the situation
17、in which the saw chain becomes stuck in the wood at a cut and is broken. The end of the saw chain passes the drive sprocket in the guide bar plane. At different saw chain speeds and combinations of distance to the saw chain breakage, the break force, guide bar geometry and saw chain preload will thr
18、ow the saw chain in a curve, producing a whiplash that could create a chain shot.The test procedures presented in this International Standard can be used to evaluate a guarding systems ability to prevent the saw chain from producing whiplash and chain shot.ISO 11837:2011(E) ISO 2011 All rights reser
19、ved vBS ISO 11837:2011BS ISO 11837:2011INTERNATIONAL STANDARD ISO 11837:2011(E)Machinery for forestry Saw chain shot guarding systems Test method and performance criteriaCAUTION The test method specified in this International Standard involves the use of processes which could lead to a hazardous sit
20、uation. The test creates saw chain shots. Under no circumstances shall the test be performed without the protective cover for the test apparatus in place. The protective cover is only to be removed when rotating parts are standing still.1 ScopeThis International Standard specifies performance requir
21、ements and a corresponding test method for saw chain shot guarding systems on the harvester heads and grip saws of forestry machines.It is applicable only to saw chain breakage on the cutting side of the guide bar.NOTE Other test methods and test apparatus can be used if shown to give equivalent per
22、formance results.2 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.2.1saw chain shotobject flying with high speed and consisting of one or more parts (drivelinks, sidelinks, cutters) of a broken saw chainNOTE 1 A saw chain consists of parts in the fo
23、rm of drivelinks, cutters and sidelinks held together by rivets.NOTE 2 The saw chain shot will have a weight of 1 g to 100 g, depending on the size of the saw chain and the broken saw chain parts.NOTE 3 During a test run, more than one saw chain shot can be created by the same saw chain whiplash, in
24、 different directions.2.2maximum design saw chain speedChighest saw chain speed under no load, for a given combination of saw chain, guide bar and drive sprocket2.3cutting attachmentcombination of saw chain, guide bar and drive sprocket mounted on the harvester head or grip saw2.4saw chain shot guar
25、ding systemsystem that prevents the saw chain from whiplashing and/or creating a saw chain shot after passing the drive sprocket in the event of a saw chain breakage2.5reference panelplane panel consisting of plastic film, kraft paper or similar material to indicate a saw chain shot ISO 2011 All rig
26、hts reserved 1BS ISO 11837:20113 Test equipment3.1 Test apparatusThe saw chain shot guarding system, with all its component parts, shall be attached to the test rig as it would be on the respective harvester head or grip saw. Alternatively, the complete harvester head or grip saw shall be attached t
27、o the test rig.3.2 Drive unitThe drive unit shall be maintained at constant speed to within 2 m/s during breakage, taking into account the increased force involved in the breakage of the saw chain.NOTE One way to accommodate this is using an electric motor (15 kW and 50 r/s) with a belt transmission
28、 gearing up the speed four times and with a flywheel mass of 15 kg mounted on the drive shaft (360 mm in diameter and 19 mm in thickness).3.3 Saw chain speed controlIt shall be possible to adjust the saw chain speed within the range of 30 m/s to 60 m/s with a maximum tolerance of 2 m/s.3.4 Drive sha
29、ft speed measurementA drive shaft speed indicator shall be used to verify the saw chain speed with a maximum uncertainty of 1,0 % of the reading.3.5 Saw chain tensioning systemThe saw chain tensioning system shall tension the saw chain according to the manufacturers recommendations.3.6 Saw chain lub
30、rication systemThe saw chain lubrication system shall lubricate the saw chain with oil flow and oil quality according to the manufacturers recommendations.3.7 Saw chain stopping deviceThe saw chain stopping device shall be as specified in Annex A.3.8 Protective coverA protective cover shall fully en
31、close the test equipment and the harvester head or grip saw under test. The protective cover shall have a strength at least equivalent to 6 mm steel sheet.4 Cutting attachment4.1 Guide barThe longest available guide bar shall be chosen for the test runs. If a guide bar with a different shape is an o
32、ption, it also shall be tested.The mounting of the guide bar shall be on a unit with original mounting attachments, according to the manufacturers specifications.ISO 11837:2011(E)2 ISO 2011 All rights reservedBS ISO 11837:20114.2 Drive sprocketThe test runs shall be performed within the manufacturer
33、s operating specifications and with the drive sprocket available in the original cutting attachment that providesa) the highest saw chain speed, andb) the largest distance between the drive sprocket and the saw chain shot guarding system.4.3 Saw chainA saw chain that is recommended in the harvester-
34、head or grip-saw manufacturers instruction handbook for use together with the guide bar and drive sprocket shall be chosen. One of the following reference saw chain dimensions shall be preferred: saw chain with 0,404 inch pitch, thickness 1,6 mm; saw chain with 0,404 inch pitch, thickness 2,0 mm; sa
35、w chain with 3/4 inch pitch, thickness 3,1 mm.The number of drive links is determined in relation to the guide bar length.5 Reference panelsThere shall be two reference panels (see items 1a and 1b in Figure 1) with a width of 400 mm 20 mm and a length of 1 000 mm 20 mm, consisting of plastic film, k
36、raft paper or similar material. The location and orientation of the two reference panels shall be as described in Figure 1.6 Pre-calibration of test arrangementThe pre-calibration is performed in order to secure the statistical confidence of the test results.Ten test runs without the saw chain shot
37、guarding system mounted shall be performed to evaluate the functioning of the test arrangement. Perform the test procedure specified in Clause 8, but without assembling the saw chain guarding system. Run five test runs at 0,8 times the maximum design saw chain speed, C, and five test runs at 1,2C. A
38、t least four of the five test runs at each speed shall result in a saw chain shot through one of the reference panels.If a complete harvester head or grip saw is tested, some parts of the saw chain shot guarding system and obstacles (see 7.3) will have to be removed prior to the pre-calibration test
39、s, to ensure that saw chain shots are created.If the criterion of at least four saw chain shots out of five test runs is not met, the test arrangement shall be modified and the pre-calibration repeated until this criterion is met.ISO 11837:2011(E) ISO 2011 All rights reserved 3BS ISO 11837:2011Dimen
40、sions in millimetres680860234a1 000 10001a1bKey1a reference panel parallel to the guide bar centre line1b reference panel perpendicular to the guide bar centre line2 saw chain shot area3 drive sprocket4 guide baraSaw chain rotation direction.Figure 1 Guide bar and location of reference planes7 Assem
41、bly of saw chain shot guarding system in test rig7.1 PositionThe saw chain shot guarding system shall be positioned at the same distance, in both the horizontal and vertical directions, from the drive sprocket as it was originally on the harvester head or grip saw.7.2 Alternative positionsIf the pos
42、ition of the saw chain shot guarding system changes relative to the guide bar during cutting, the system shall be tested in the following three different positions: Position 1 guide bar in “home” position; Position 2 guide bar at half cutting depth; Position 3 guide bar at maximum cutting depth.ISO
43、11837:2011(E)4 ISO 2011 All rights reservedBS ISO 11837:20117.3 ObstaclesAny part or parts on the harvester head or grip saw which can be considered to influence the behaviour of a broken saw chain shall be included in the test.EXAMPLE Screws, nuts, welding, saw casing and reinforcements.8 Test proc
44、edureThe test shall be performed as follows.a) Assemble the saw chain shot guarding system and the cutting attachment (guide bar, saw chain and drive sprocket) in the test rig. Use only new saw chains.Alternatively, a complete harvester head or grip saw may be attached to the test rig.b) Connect the
45、 drive sprocket to the drive system and activate the saw chain lubrication system.c) Position the saw chain stopping device (see Annex A). The position shall depend on the guide bar length, XS, measured from the centre of the drive sprocket to the guide bar tip. See Figure 2. Distance X1shall be 0,5
46、XSand distance X2shall be 0,8XS.X1X2XSFigure 2 Saw chain stopping device positionsd) Preload the saw chain stopping device and block it in the start position as close as possible to the saw chain while allowing the saw chain to move freely. See Figure A.1.e) Unblock the saw chain stopping device and
47、 put the protective cover in position before performing any test runs.f) Adjust the saw chain tension and, with the protective cover in place, allow the cutting attachment to run in and warm up.g) Start the test run by running the saw chain.h) Adjust and calibrate the saw chain speed to the chosen t
48、est speed, maintaining that speed constant to within 2 m/s.i) Release the saw chain stopping device.j) Turn off the power source to the drive system and allow all rotating parts to come to a complete stop.k) Open the protective cover.l) Evaluate all reference panels. If a reference panel has been pe
49、netrated by a saw chain, report this.m) Photograph each test sample of broken saw chain, including all loose parts.n) Continue with the next test run in accordance with Clause 9.ISO 11837:2011(E) ISO 2011 All rights reserved 5BS ISO 11837:20119 Total number of test runsEach test run shall consist of three tests with the same configuration of the test rig. The total number of test runs will also depend on the number of different guide bars (see 4.1), sprockets (see 4.2) and possible saw chain shot gu
