EN 13906-2:2013

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Zylindrische Schraubenfedern aus runden Drähten und Stäben - Berechnung und Konstruktion - Teil 2: ZugfedernRessorts hélicoïdaux cylindriques fabriqués à partir de fils ronds et de barres - Calcul et conception - Partie 2: Ressorts de tractionCylindrical helical springs made from round wire and bar - Calculation and design - Part 2: Extension springs21.160VzmetiSpringsICS:Ta slovenski standard je istoveten z:EN 13906-2:2013SIST EN 13906-2:2014en,fr,de01-januar-2014SIST EN 13906-2:2014SLOVENSKI
STANDARDSIST EN 13906-2:20091DGRPHãþD

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 13906-2
June 2013 ICS 21.160 Supersedes EN 13906-2:2001English Version
Cylindrical helical springs made from round wire and bar - Calculation and design - Part 2: Extension springs
Ressorts hélicoïdaux cylindriques fabriqués à partir de fils ronds et de barres - Calcul et conception - Partie 2: Ressorts de traction
Zylindrische Schraubenfedern aus runden Drähten und Stäben - Berechnung und Konstruktion - Teil 2: ZugfedernThis European Standard was approved by CEN on 16 May 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.
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for cold coiled springs . 12 10.3 Permissible torsional stress τzul
for hot coiled springs . 12 10.4 Initial tension torsional stress τ0 . 12 11 Calculation of extension springs for dynamic loading . 13 Annex A (informative)
Types of spring ends . 14 Bibliography . 18
NOTE In cases of substantially higher or lower working temperature, it is advisable to seek the manufacturer’s advice. 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 10270-1, Steel wire for mechanical springs — Part 1: Patented cold drawn unalloyed spring steel wire EN 10270-2, Steel wire for mechanical springs — Part 2: Oil hardened and tempered spring steel wire EN 10270-3, Steel wire for mechanical springs — Part 3: Stainless spring steel wire EN 10089, Hot-rolled steels for quenched and tempered springs — Technical delivery conditions EN 12166, Copper and copper alloys — Wire for general purposes EN ISO 26909:2010, Springs — Vocabulary (ISO 26909:2009) ISO 26910-1, Springs — Shot peening — Part 1: General procedures 3 Terms and definitions, symbols, units and abbreviated terms 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in EN ISO 26909:2010 and the following apply. 3.1.1 spring mechanical device designed to store energy when deflected and to return the equivalent amount of energy when released [SOURCE: EN ISO 26909:2010, 1.1] 3.1.2 extension spring spring (1.1) that offers resistance to an axial force tending to extend its length, with or without initial tension [SOURCE: EN ISO 26909:2010, 1.3] SIST EN 13906-2:2014

Symbols
Units Terms 2ieDDD+= mm mean diameter of coil De mm outside diameter of the spring Di mm inside diameter of the spring d mm nominal diameter of wire (or bar) E N/mm² (MPa) modulus of elasticity (or Young’s modulus) F0 N initial tension force F N spring force
F1, F2. N spring forces, for the spring lengths L1, L2 . (at ambient temperature of 20 ºC) Fn N maximum permissible spring force for the maximum permissible spring length Ln G N/mm² (MPa) modulus of rigidity
k - stress correction factor (depending on D/d) L mm spring length L0 mm Nominal free length of spring L1, L2. mm spring lengths for the spring forces F1, F2 . LH mm distance from inner radius of loop to spring body LK mm body length when unloaded but subject to initial tension force Ln mm maximum permissible spring length for the spring force Fn m mm hook opening N - Number of cycles up to rupture n - number of active coils nt - total number of coils R N/mm spring rate
Table 2 (2 of 2)
Symbols
Units Terms Rm N/mm² (MPa) minimum value of tensile strength s mm spring deflection
s1, s2 .
mm spring deflections, for the spring forces F1, F2 .
sh mm deflection of spring (stroke) between two positions sn mm spring deflection, for the spring force Fn W Nmm spring work dDw= - spring index ρ kg/dm3 density τ N/mm² (MPa) uncorrected torsional stress (without the influence of the wire curvature being taken into account) τ0 N/mm² (MPa) uncorrected torsional stress, for the initial tension force F0 τ1, τ2 .
N/mm² (MPa) uncorrected torsional stress, for the
spring forces F1, F2 . τk N/mm² (MPa) corrected torsional stress, (according to the correction factor k) τk1, τk2 . N/mm² (MPa) corrected torsional stress, for the
spring forces F1, F2 . τkh N/mm² (MPa) corrected
torsional stress range, for the stroke
sh τkn N/mm² (MPa) corrected torsional stress, for the
spring force Fn τn N/mm² (MPa) uncorrected torsional stress, for the spring force Fn τzul N/mm² (MPa) permissible torsional stress
4 Theoretical extension spring diagram The illustration of the extension spring corresponds to Figure 5.1 from EN ISO 2162-1:1996. The theoretical extension spring diagram is given in Figure 1. SIST EN 13906-2:2014

Key 1
spring deflection 2
spring lengths Figure 1 — Theoretical extension spring diagram 5 Types of loading 5.1 General Before carrying out design calculations, it should be specified whether they will be subjected to static loading, quasi-static loading or dynamic loading. 5.2 Static and/or quasi-static loading A static loading is:  a loading constant in time. A quasi-static loading is:  a loading variable with time with a negligibly small torsional stress range (stroke stress) (e.g. torsional stress range up to 10 % of fatigue strength);  a variable loading wit
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