EN 847-2:2013
(Main)Tools for woodworking - Safety requirements - Part 2: Requirements for the shank of shank mounted milling
Tools for woodworking - Safety requirements - Part 2: Requirements for the shank of shank mounted milling
This European Standard specifies the determination of the maximum speed for given eccentricity at clamping devices for the shank strength of milling tools with cylindrical and taper shank. It also specifies the marking of the tool. Bore mounted tools which are mounted on an arbor should be considered as a shank mounted tool.
This European Standard complements EN 847 1 and applies also for shank tools with a cutting diameter of less than 16 mm.
Maschinen-Werkzeuge für Holzbearbeitung - Sicherheitstechnische Anforderungen - Teil 2: Anforderungen für den Schaft von Fräswerkzeugen
Diese Europäische Norm legt die Bestimmung der Höchstdrehzahl für gegebene Exzentrizitäten an Spannzeugen für die Schaftfestigkeit von Fräswerkzeugen mit Zylinder- und Kegelschaft fest. Sie legt auch die Kennzeichnung des Werkzeuges fest. Bohrungswerkzeuge, die an einem Aufnahmedorn befestigt sind, sollten als ein Werkzeug mit Schaft angesehen werden.
Diese Europäische Norm ergänzt EN 847 1 und gilt auch für Schaftwerkzeuge mit einem Schneidenkreisdurchmesser von weniger als 16 mm.
Outils pour le travail du bois - Prescriptions de sécurité - Partie 2: Prescriptions pour les queues des fraise à queue
La présente Norme européenne spécifie la détermination de la vitesse maximale, pour une excentricité donnée au niveau des dispositifs de serrage, pour la résistance de la queue des fraises à queue cylindrique et à queue conique. Elle spécifie également le marquage de l’outil. Il convient de considérer lles outils avec alésage montés dans un mandrin comme des outils à queue.
La présente norme complète l'EN 847-1 et s’applique également aux outils à queue de diamètre coupant inférieur à 16 mm.
Orodja za obdelavo lesa - Varnostne zahteve - 2. del: Zahteve za držalo rezkalnih orodij
Ta evropski standard določa največje hitrosti za dano ekscentričnost pri vpenjalnih napravah za moč stojala frezal s cilindričnim in stožčastim stojalom. Prav tako določa označevanje orodja. Orodja, ki se pritrdijo v izvrtino in so pritrjena na stojalo, naj bi bila obravnavana kot orodja, pritrjena na stojalo. Ta evropski standard dopolnjuje standard EN 847-1 in se uporablja tudi za orodja, ki so pritrjena na stojalo in imajo premer rezanja manjši od 16 mm.
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-januar-2014
1DGRPHãþD
SIST EN 847-2:2002
SIST EN 847-2:2002/AC:2004
Orodja za obdelavo lesa - Varnostne zahteve - 2. del: Zahteve za držalo rezkalnih
orodij
Tools for woodworking - Safety requirements - Part 2: Requirements for the shank of
shank mounted milling
Maschinen-Werkzeuge für Holzbearbeitung - Sicherheitstechnische Anforderungen - Teil
2: Anforderungen für den Schaft von Fräswerkzeugen
Outils pour le travail du bois - Exigences de sécurité - Partie 2: Prescriptions pour les
queues des fraises à queue
Ta slovenski standard je istoveten z: EN 847-2:2013
ICS:
25.100.20 Orodja za frezanje Milling tools
79.120.10 Lesnoobdelovalni stroji Woodworking machines
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 847-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2013
ICS 79.120.10 Supersedes EN 847-2:2001
English Version
Tools for woodworking - Safety requirements - Part 2:
Requirements for the shank of shank mounted milling
Outils pour le travail du bois - Prescriptions de sécurité - Maschinen-Werkzeuge für Holzbearbeitung -
Partie 2: Prescriptions pour les queues des fraise à queue Sicherheitstechnische Anforderungen - Teil 2:
Anforderungen für den Schaft von Fräswerkzeugen
This European Standard was approved by CEN on 10 August 2013.
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 CEN-CENELEC 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 CEN-CENELEC Management Centre has the same
status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 847-2:2013: E
worldwide for CEN national Members.
Contents Page
Foreword .3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 List of significant hazards .6
5 Safety requirements .6
5.1 General requirements for cylindrical shank .6
5.2 Stability of the shank of mounted tools .6
5.3 Stability of HSK mounted tools . 12
6 Tool marking . 14
Annex A (informative) Examples of calculation . 16
A.1 Example of a calculation of n . 16
shank
A.2 Example of a calculation of n . 17
HSK
Annex B (informative) Method of measuring the eccentricity at clamping devices . 18
Bibliography . 19
Foreword
This document (EN 847-2:2013) has been prepared by Technical Committee CEN/TC 142 “Woodworking
machines - Safety”, the secretariat of which is held by UNI.
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 April 2014, and conflicting national standards shall be withdrawn at the
latest by April 2014.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 847-2:2001.
The following table contains a list of modifications from the previous edition.
EN 847-2:2001 EN 847-2:2013 Reason
1 Scope 1 Scope: ed/te
Precision of the indent
New paragraph: applies also for
shank tools with a cutting diameter
of less than 16 mm
3 Quantities and units 3 Terms and definitions ed
5 Tool marking 5 Safety requirements: te (missing requirements)
5.1 General requirements for
cylindrical shank
5.2 Stability of the shank of the
shank mounted tools
5.3 Stability of HSK mounted tools
6 Safety requirements 6 Tool marking te
Changed symbol for the free
shank length
Annex A: Method of measuring Annex A: Examples of calculation ed
the eccentricity at clamping
devices
Annex B: Example of calculation Annex B: Method of measuring the ed
eccentricity at clamping devices
New: Bibliography ed
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Introduction
The content of this European 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 Scope
This European Standard specifies the determination of the maximum speed for given eccentricity at clamping
devices for the shank strength of milling tools with cylindrical and taper shank. It also specifies the marking of
the tool. Bore mounted tools which are mounted on an arbour should be considered as a shank mounted tool.
This European Standard complements EN 847-1 and applies also for shank tools with a cutting diameter of
less than 16 mm.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
EN 847-1:2013, Tools for woodworking — Safety requirements — Part 1: Milling tools, circular saw blades
EN ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk
reduction (ISO 12100:2010)
ISO 1940-1, Mechanical vibration — Balance quality requirements for rotors in a constant (rigid) state —
Part 1: Specification and verification of balance tolerances
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 847-1:2013 and the following apply.
3.1
7/24 shank
SK
type of toolholder with a 7/24 cone ratio taper that contacts the spindle on two surfaces
Note 1 to entry: Toolholder with a 7/24 cone ratio taper; see Bibliography.
3.2
hollow taper shank
HSK
type of toolholder with a short hollow taper with a high positioning accuracy and high grade of rigidity that
contacts the spindle on two surfaces
Note 1 to entry: Toolholder with 1:1,09 cone ratio hollow taper shank; see Bibliography.
3.3
arbour
device to mount in or on the spindle of a machine tool, and which is designed to carry and drive a bore type
cutting tool
4 List of significant hazards
Table 1 shows the list of significant hazards.
Table 1 — List of significant hazards
Hazard according to Condition or causes of hazard Corresponding clause of
EN ISO 12100:2010 related to the tool EN 847-2
Mechanical hazards due to:
Breaking of the tool 5
Inadequacy of mechanical strength
Vibration Dynamic unbalance of tool 5
Variations in the rotational speed of
Breaking of the tool 5
tools
5 Safety requirements
5.1 General requirements for cylindrical shank
The minimum value for the clamping length l shall be as given in Table 2.
e min
Table 2 — Minimum clamping length l
e min
10 mm < d < 25 mm
d ≤ 10 mm d ≥ 25 mm
2 2
l = 20 mm
l = 2 ⋅ d (mm) l = 1,8 ⋅ d (mm)
e min e min 2 e min 2
The tolerance of the shank diameter d shall be h6 for d ≥ 12 mm and h8 for d < 12 mm. The method of
2 2 2
measuring the eccentricity e at clamping devices, as given in Annex B, shall be used.
m
5.2 Stability of the shank of mounted tools
Every shank of a mounted milling tool shall be calculated with the quantities and units as shown in Figure 1a)
(with d = d ).
If the shank mounted milling tool is clamped in a taper holder, the cone strength shall be calculated with the
quantities and units as shown in Figure 1b) (with d = d ).
If tools are mounted on a taper shank, the shank strength of the clamping diameter shall be calculated with
the quantities and units as shown in Figure 1c) with
l = l
e g
l = 0
d = 1,4 · d (d ≤ 50mm)
4 arbour arbour
d = 20 + d (d > 50mm)
4 arbour arbour
NOTE 1 Clamping systems:
with axial clamping force [Fa] d = d4;
without axial clamping force [Fa] d = d .
arbour
a)
b)
Figure 1 — Quantities for calculation of n (1 of 2)
shank
c)
Key
a axis of rotation
Figure 1 — Quantities for calculation of n (2 of 2)
shank
For balance quality, see EN 847-1:2013, Table 5.
For calculation of n with a given e the following formula applies:
sp
W ⋅ ⋅
W ⋅
σ σ l
2 w w s 6
− G + + ⋅ + ⋅
G e 10
sp
*
3 ⋅ E ⋅ I
⋅
m
l
s
30
= ⋅ (1)
n
shank
f ⋅ π
W ⋅ ⋅
σ l
w s
S
+
e
sp
3 ⋅ E ⋅ I
For calculation of e with a given n the following formula applies:
sp
W ⋅ ⋅
1 30 W ⋅ 30 ⋅ G
σ σ l
w 6 w s
= ⋅ ⋅ ⋅ − ⋅ (2)
e 10
sp
*
n π 3 ⋅ E ⋅ I
f ⋅ π ⋅ ⋅ n
m
l
s
S
30 ⋅ G
e = (3)
per
π ⋅ n
shank
The mass m of the tool components related to the centre of gravity S in the area of l + l , is given in
cut 0 1
Figure 1.
m* = f ⋅ m (4)
cut
f = 0,04 + 0,17 ⋅ ln (m ) (5)
cut
This is an empiric formula of which the result is only valid between 0,6 and 0,9. 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 2 The expression "In (m )" is the natural logarithm of mass of the tool without shank.
cut
d
I = π ⋅ (6)
l = l − l (7)
0 g e
If known the real mass can be used in place of the reduced mass.
d
W =π ⋅ (8)
EXAMPLE Figure 2 and Formula (9) give an example for the calculation of the distance l .
s
Figure 2 — Distances of the gravity centres of the tool components
m ⋅l + m ⋅l + m ⋅l + m ⋅l
1 S,1 2 S,2 3 S,3 4 S,4
l =
S (9)
m + m + m + m
1 2 3 4
Table 3 — Stability of the shank of the shank mounted tools — Quantities and units
Quantity Description Unit
d diameter mm
a) shank diameter d
b) cone diameter d
c) with axial force d : calculated; without axial force: d
4 arbour
d tool diameter mm
d shank diameter, see Figure 1a) mm
d cone diameter, see Figure 1b) mm
d calculated hub diameter, see Figure 1c) mm
d shank diameter of the arbour, see Figure 1c) mm
arbour
−
E
modulus of elasticity N mm
e permissible gravity centre displacement mm
per
a
e eccentricity at clamping device mm
sp
f form factor
f safety factor (f = 4) ./.
s S
F
axial clamping force, see Figure 1c) N
a
− 1
G product of the permissible eccentricity and the angular velocity according to ISO 1940-1
mm s
I
second moment of area mm
l height of tool components mm
l free shank length mm
l distance of gravity centre measured from the end of the clamping device mm
s
l clamping length mm
e
l total length of shank mm
g
m mass of the tool components related to the centre of gravi
...
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