SIST EN 13906-3:2014

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 3: DrehfedernRessorts hélicoïdaux cylindriques fabriqués à partir de fils ronds et de barres - Calcul et conception - Partie 3: Ressorts de torsionCylindrical helical springs made from round wire and bar - Calculation and design - Part 3: Torsion springs21.160VzmetiSpringsICS:Ta slovenski standard je istoveten z:EN 13906-3:2014SIST EN 13906-3:2014en,fr,de01-april-2014SIST EN 13906-3:2014SLOVENSKI
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SIST EN 13906-3:2014



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 13906-3
January 2014 ICS 21.160 Supersedes EN 13906-3:2001English Version
Cylindrical helical springs made from round wire and bar - Calculation and design - Part 3: Torsion springs
Ressorts hélicoïdaux cylindriques fabriqués à partir de fils ronds et de barres - Calcul et conception - Partie 3: Ressorts de torsion
Zylindrische Schraubenfedern aus runden Drähten und Stäben - Berechnung und Konstruktion - Teil 3: DrehfedernThis European Standard was approved by CEN on 10 November 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.
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EN 13906-3:2014 (E) 2 Contents Page Foreword . 3 1 Scope . 4 2 Normative references . 4 3 Terms and definitions, symbols, units and abbreviated terms . 4 3.1 Terms and definitions . 4 3.2 Symbols, units and abbreviated terms . 5 4 Theoretical torsion spring diagram . 7 5 Design Principles . 10 5.1 General . 10 5.2 Design of the ends . 10 5.3 Mounting of the ends . 11 5.4 Design of the spring body . 11 6 Types of loading . 12 6.1 General . 12 6.2 Static and quasi-static loading . 12 6.3 Dynamic loading . 12 7 Stress correction factor q . 13 8 Material property values for the calculations of springs . 14 9 Design formulate. 15 9.1 Design assumptions . 15 9.2 Formulae . 15 9.2.1 General . 15 9.2.2 Spring torque . 15 9.2.3 Angular spring rate . 15 9.2.4 Developed length of active coils . 16 9.2.5 Nominal diameter of wire or bar . 16 9.2.6 Inside coil diameter of the spring . 16 9.2.7 Outside coil diameter of the spring . 16 9.2.8 Body length of the spring (excluding ends) . 16 9.2.9 Number of active coils . 16 9.2.10 Torsional angle . 16 9.2.11 Spring work . 17 9.2.12 Uncorrected bending stress . 17 9.2.13 Corrected bending stress . 17 10 Permissible bending stress . 20 10.1 Permissible bending stress under static or quasi-static loading . 20 10.2 Permissible stress range under dynamic loading . 20 10.2.1 Fatigue strength values . 20 10.2.2 Permissible stress range . 20 10.2.3 Lines of equal stress ratio . 21 Bibliography . 22
SIST EN 13906-3:2014



EN 13906-3:2014 (E) 3 Foreword This document (EN 13906-3:2014) has been prepared by Technical Committee CEN/TC 407 “Project Committee - Cylindrical helical springs made from round wire and bar - Calculation and design”, the secretariat of which is held by AFNOR. 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 July 2014, and conflicting national standards shall be withdrawn at the latest by July 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 13906-3:2001. This European Standard has been prepared by the initiative of the Association of the European Spring Federation ESF. This European Standard constitutes a revision of EN 13906-3:2001 for which it has been technically reviewed. The main modifications are listed below: — updating of the normative references; — technical corrections. EN 13906 consists of the following parts, under the general title Cylindrical helical springs made from round wire and bar — Calculation and design: — Part 1: Compression springs; — Part 2: Extension springs; — Part 3: Torsion springs. According to the CEN-CENELEC Internal Regulations, the national standards organizations 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. SIST EN 13906-3:2014



EN 13906-3:2014 (E) 4 1 Scope This European Standard specifies the calculation and design of cold and hot coiled cylindrical helical torsion springs with a linear characteristic, made from round wire and bar of constant diameter with values according to Table 1. Table 1 Characteristic Cold coiled torsion spring Hot coiled torsion springa Wire or bar diameter d ≤ 20 mm d ≥ 10 mm Number of active coils n
≥ 2 n
≥ 2 Spring index 4 ≤ w ≤ 20 4 ≤ w ≤ 12 a The user of this European Standard shall pay attention to the design of hot coiled springs, because there can be differences between the design and a real test. 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 10089, Hot-rolled steels for quenched and tempered springs - Technical delivery conditions 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 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 torsion spring spring that offers resistance to a twisting moment around the longitudinal axis of the spring [SOURCE: EN ISO 26909:2010, 1.4] SIST EN 13906-3:2014



EN 13906-3:2014 (E) 5 3.1.3 helical torsion spring torsion spring normally made of wire of circular cross-section wound around an axis and with ends suitable for transmitting a twisting moment [SOURCE: EN ISO 26909:2010, 3.14] 3.2 Symbols, units and abbreviated terms Table 2 contains the symbols, units and abbreviated terms used in this standard. Table 2 Symbols Units Terms DA mm coil diameter tolerance of the unloaded spring a mm gap between active coils of the unloaded spring ei2DDD+=
mm mean diameter of coil dD mm mandrel diameter eD mm outside diameter of the spring eDα mm outside coil diameter of the spring when deflected through and angle . in the direction of the coiling hD mm housing diameter iD mm inside diameter of the spring iαD mm inside coil diameter of the spring when deflected through and angle . in the direction of the coiling pD mm test mandrel diameter d mm nominal diameter of wire (or bar) maxd mm upper deviation of d Rd mm diameter of loading pins E N/mm2 (MPa) modulus of elasticity (or Young's modulus) F N spring force .
,21FF N spring forces for the torsional angles .
,21ααand related lever arms BA ,RRat ambient temperature of 20 °C nF N spring force for the maximum permissible angle nαand the lever arms BA ,RR KL mm body length of the unloaded spring for close-coiled springs (excluding ends) K0L mm body length of the unloaded spring for open-coiled springs (excluding ends) KLα mm body length of close-coiled spring deflected through an angle . (excluding ends) l mm developed length of active coils (excluding ends)
,BAll mm length of ends M N mm spring torque SIST EN 13906-3:2014



EN 13906-3:2014 (E) 6 Symbols Units Terms .
,21MM N mm spring torque for the angles .
,21ααand related lever arms BA ,RRat ambient temperature of 20 °C nM N mm spring torque for the maximum permissible angle, .n maxM N mm maximum spring torque, which occurs occasionally in practice, in test or during assembly of the spring N - number of cycles up to rupture n - number of active coils q - stress correction factor (depending on D/d)
, ,BARRR mm effective lever arms of spring mR N/mm2 (MPa) minimum value of the tensile strength MRR Nmm/Deg angular spring rate (increase of spring torque per unit angular deflection) nBA .
, ,rrrr mm inner bending radii W mm3 sectional moment W N mm spring work =Dwd
- spring index z - decimal values of the number of active coils n α Deg torsional angle .
,21αα Deg torsional angle corresponding to spring torque M1, M2 . to the spring forces F1, F2 . nα Deg maximum permissible torsional angle α′ Deg corrected torsional angle . in the case of a long, unclamped radial end α′′ Deg corrected torsional angle . in the case of a long, unclamped tangential end hα Deg angular deflection of spring (stroke) between two positions
and 21αα maxα Deg maximum torsional angle which occurs occasionally in practice, in test or by mounting of the spring β Deg increase of
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