【BS英国标准】BS EN 847-2-2001 Tools for woodworking — Safety requirements — Part 2 Requirements for the shank of shank-mounted milling tools.doc

british standard bs en847-2:2001incorporating corrigenda nos. 1 and 2tools forwoodworking safety requirements part 2: requirements for the shank of shank-mounted milling toolsthe european standard en 847-2:2001 has the status of abritish standardics 79.120.10-,-,- copyright british standards institutionreproduced by ihs under license with bsi - uncontrolled copydocument provided by ihs licensee=bureau veritas/5959906001, 11/08/200406:08:23 mst questions or comments about this message: please call the documentpolicy group at 303-397-2295.bs en 847-2:2001national forewordthis british standard is the official english language version ofen 847-2:2001, including corrigendum march 2003.the uk participation in its preparation was entrusted to technical committeemte/23, woodworking machinery safety, which has the responsibility to:aid enquirers to understand the text;present to the responsible 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 the uk.a list of organizations represented on this committee can be obtained on request to its secretary.cross-referencesthe british standards which implement international or european publications referred to in this document may be found in the bsi catalogue under the section entitled “international standards correspondence index”, or by using the “search” facility of the bsi electronic catalogue or of british standards online.this publication does not purport to include all the necessary provisions of a contract. users are responsible for its correct application.compliance with a british standard does not of itself confer immunity from legal obligations.-,-,-this british standard, having been prepared under the direction of the engineering sector committee, was published under the authority of the standards committee and comes into effect on15 may 2001 bsi 6 november 2003isbn 0 580 37574 9summary of pagesthis document comprises a front cover, an inside front cover, the en title page,pages 2 to 8 an inside back cover and a back cover.the bsi copyright notice displayed in this document indicates when the document was last issued.sidelining in this document indicates the most recent changes by amendment.amd. no.datecomments14384corrigendum no. 126 february 2003correction to equation in clause 614701corrigendum no. 26 november 2003indicated by a sideline in the marginamendments issued since publicationeuropean standard norme europenneeuropische normen 847-2march 2001ics 79.120.10incorporating corrigendum march 2003english version-,-,-tools for woodworking safety requirements part 2: requirements for the shank of shank-mounted milling toolsoutils pour le travail du bois prescriptions de scurit partie 2: prescriptions pour les queues des fraises queuemaschinen-werkzeuge fr holzbearbeitung sicherheitstechnische anforderungen teil 2: anforderungen fr den schaft von frswerkzeugenthis european standard was approved by cen on 18 january 2001.cen members are bound to comply with the cen/cenelec internal regulations which stipulate the conditions for giving this european standard the status of a national standard without any alteration. up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the management centre or to any cen member.this european standard exists in three official versions (english, french, german). a version in any other language made by translation under the responsibility of a cen member into its own language and notified to the management centre has the same status as the official versions.cen members are the national standards bodies of austria, belgium, czech republic, denmark, finland, france, germany, greece, iceland, ireland, italy, luxembourg, netherlands, norway, portugal, spain, sweden, switzerland and united kingdom.european committee for standardization c om i t eur op en de no r m al i s ati on eur o p i s c hes kom i t ee f r n or m ung management centre: rue de stassart, 36 b-1050 brussels 2001 cenall rights of exploitation in any form and by any means reserved worldwide for cen national members.ref. no. en 847-2:2001 epage 2en 847-2:2001forewordthiseuropeanstandardhasbeenpreparedbytechnicalcommitteecen/tc 142, woodworking machines safety, the secretariat of which is held by bsi.-,-,-this european standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by september 2001, and conflicting national standards shall be withdrawn at the latest by september 2001.this european standard has been prepared under a mandate given to cen by the european commission and the european free trade association. this european standard is considered to be a supporting standard to those application and product standards which in themselves support an essential safety requirement of a new approach directive and which make reference to this european standard.annex a is normative and annex b is informative.according to the cen/cenelec internal regulations, the national standards organizations of the following countries are bound to implement this european standard: austria, belgium,czech republic, denmark, finland, france, germany, greece, iceland, ireland, italy, luxembourg,netherlands, norway, portugal, spain, sweden, switzerland and the united kingdom.introductionthe content of this standard is aimed at eliminating hazards which can lead to overloading of the shank of shank-mounted milling tools for woodworking by excessive rotational speeds.1 scopethis european standard specifies the determination of the maximum speed for given eccentricity at clamping devices for the shank strength of milling tools with cylindrical shank and marking of the tool. it applies to shank-mounted milling tools for woodworking irrespective of whether they are mounted perpendicularly or horizontally.this standard complements en 847-1.2 normative referencesthis european standard incorporates, by dated or undated reference, provisions from other publications. these normative references are cited at the appropriate places in the text and the publications are listed hereafter. for dated references, subsequent amendments to or revisions of any of these publications apply to this european standard only when incorporated in it by amendment or revision. for undated references, the latest edition of the publication referred to applies (including amendments).en 847-1tools for woodworking safety requirements part 1: milling tools and circular saw blades.en 1050safety of machinery principles for risk assessment.iso 1940-1mechanical vibration balance quality requirements of rigid rotors part 1: determination of permissible residual unbalance.copyright british standards institutionreproduced by ihs under license with bsi - uncontrolled copydocument provided by ihs licensee=bureau veritas/5959906001, 11/08/200406:08:23 mst questions or comments about this message: please call the documentpolicy group at 303-397-2295.page 3en 847-2:20013 quantities and unitsa axis of rotationfigure 1 illustration of quantities and unitstable 1 quantities and unitsquantitiesdescriptionunitsd1is the tool diametermmd2is the shank diametermmeis the modulus of elasticitynmm-2eper30 gis the permissible gravity centre displacement: eper = nshankmmespis the eccentricity at clamping devicemmfis the form factor:f = 0,04 + 0,17 ln (mcut)this is an empirical formula of which the result is only valid between 0,6 and0,9. if the result is less than 0,6 use 0,6, and if the result is greater than 0,9 use 0,9. the form factor takes into account the deviation of the actual form (e.g. gullet; flattening) from the solid body form of the tool without shank.note in (mcut) is the natural logarithm of mass of the tool without shank.(./.)gis the product of the permissible eccentricity and the angular velocity according to iso 1940-1mms-1-,-,-page 4en 847-2:2001i(d )4is the second moment of area: i = 264mm4l1is the tool heightmml0is the free shank length: l0 = lg - lemmlsis the distance of gravity centre measured from the end of the clamping devicemmleis the clamping lengthmmlgis the total length of shankmmmcutis the mass of tool without shank (as solid body)gm*is the reduced mass of the total tool:1m* = f mcut +(d2)2 l0 /4.4the value takes into account the fact that the mass of the free shank is not placed in the centre of gravity of the milling tool.if known, the reduced mass can be replaced by the real mass.gnis the operational speedmin-1nshankis the maximum permissible rotational speed with regard to shank strengthmin-1sis the centre of gravityw (d )3is the section modulus : w = 2 32mm3wis the fatigue strength under reversed bending stressesnmm-2is the density of shank materialgmm-34 list of hazardstable 2 shows the list of hazards.table 2 list of hazardshazard according toen 1050condition or causes ofhazard related to the toolcorresponding clause ofthis european standardmechanical hazards due to:-inadequacy of mechanical strengthbreaking of the tool6vibrationdynamic unbalance of tool6variations in the rotational speedof toolsbreaking of the tool6-,-,-page 5en 847-2:20015 tool markingas an exception to the permissible speed range according to 7.4 of en 847-1, shank-mounted milling tools shall only be marked with the value of nshank or nmax according to of en 847-1, whichever is the lower. additionally the permissible eccentricity shall be marked (e.g. n max 12 000 e 0.06). the maximum free shank length shall also be marked as illustrated in figure 2.figure 2 marking of the maximum free shank length-,-,-6 safety requirementsfor composite tools “g” shall be 16 or less for the balance quality grade 16 according to iso 1940-1. for complex tools, “g” shall be 40 or less for the balance quality grade 40 according to iso 1940-1.for calculation of n with a given esp the following equation applies:2 nshank = g +15 g 2 + w wm* lsesp+ w w (ls )3 e i2 106 esp+ w w (ls )3 e ifor calculation of esp with a given n the following equation applies:1 15 2w 30 g w (l )2e= w 106 w s sspn m* l n3 e ithe safety requirements for the shank strength are fulfilled when using the given tool and material sizes with defined free shank length lo, gravity centre displacement eper and eccentricity at clamping device esp, the maximum permissible rotational speed for the shank nshank is not exceeded during operation. the cutting force is not significant in comparison with the centrifugal force. therefore the cutting force has not been taken into account.for general use nshank shall be calculated for esp = 0,1 mm and for tools used on nc- and cnc-machines nshank shall be calculated for esp = 0,06. in other cases the value of esp shall be taken according to the equation.for the operation of complex shank-mounted milling tools it has to be considered that the maximum permissible operational speed may not exceed the lower value of the two maximum speed values for the shank strength (nshank) as well as the strength to overspeed load (nmax) in accordance with of en 847-1.page 6en 847-2:2001the minimum value for the clamping length le shall be as given in table 3:table 3 clamping lengthd2 10 mm10 mm d2 25 mmd2 25 mmle 20 mmle 2 d2 (mm)le 1,8 d2 (mm)the tolerance of the shank diameter d2 shall be g7 for d2 12 mm and g8 for d2 12 mm. the measured eccentricity em shall be esp.the method of measuring the eccentricity em at clamping devices as given in annex a shall be used.-,-,-page 7en 847-2:2001annex a (normative)method of measuring the eccentricity at clamping devicesthe diameter of the test mandrel is the nominal diameter of the clamping device. for the test mandrel the following shall apply:a) test mandrel diameter tolerance: g7/g8 in accordance with clause 6;b) test mandrel cylindricity: 0,002 mm;-,-,-c) test mandrel straightness: 0,002 mm; d) test mandrel roundness: 0,002 mm; e) surface without longitudinal marks;f) surface roughness: max. rz = 4 m;g) surface hardness: 58 + 3 hrc.key1driving spindle/clamping device shank2clamping device3test point 14test point 25test mandrell110 mml2(lg + l1) - let1run-out at test point 1 t2run-out at test point 2 angular deviationfigure a.1 measuring method illustrationfor the calculation of the measured eccentricity em the following equation applies:measured eccentricity: em= t1 + t 2 esp4page 8-,-,-en 847-2:2001annex b (informative)table b.1 calculation examplequantityvalueunitshank diameter (d2)25mmtotal shank length (lg)80mmfree shank length (l0)25mmtool diameter (d1)125mmtool height (l1)40mmform factor (f)0,9mass of cutting part (f mcut)3 468,02greduced total mass (m*)3 492,11gdistance of gravity centre (ls)45mmg for balance quality gradeg 40 for complex tools40mms-1fatigue strength under reversed stresses (w)340nmm-2modulus of elasticity (steel) (e)210 000nmm-2density (steel) ()0,007 85gmm-3permissible rotational speed for esp = 0,1 (nshank)19 098min- 1-,-,-copyright british standards institutionreproduced by ihs under license with bsi - uncontrolled copydocument provided by ihs licensee=bureau veritas/5959906001, 11/08/200406:08:23 mst questions or comments about this message: please call the documentpolicy group at 303-397-2295.bs en847-2:2001bsi389 chiswick high roadlondonw4 4albsi british standards institutionbsi is the independent national body responsible for preparingbritish standards. it presents the uk view on standards in europe and at the international level. it is incorporated by royal charter.revisionsbritish standards are updated by amendment or revision. users ofbritish standards should make sure that they possess the latest amendments or editions.it is the constant aim of bsi to improve the quality of our products and services. we would be grateful if anyone finding an inaccuracy or ambiguity while using this british standard would inform the 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