1、A. E. C. M, A. STAN DA i? D NORME A.E.C.M.A, A.E.C.M.A. NORM 14 th September 1987 prEN 3149 Issue P I September 1987 after the date of publication decision 88, Bd. Malesherbes A.E.C.M.A. Mr. WILLIAMS 75008 PARIS - FRANCE DIT PAR LASSOCIATION EUROPENNE DES CONSTRUCTEURS DE MATRIEL AROSPATIAL 88, boul
2、evard Malesherbes, 75008 PARIS -TL. 45-63-82-85 UDC : Key words- : ENGLISH VERSION Aerospace series Shank nuts, metric Installation holes Srie arospatiale crous sertir, mtrique Trou dinstallation Luft- und Raumfahrt Einnietmuttern, metrisch Einbaulcher This .Aerospace Series pre-standard has been dr
3、awn up under the responsibility of AECMA (Association Europenne des Constructeurs de Matriel Arospatial). It is published on green paper for the needs of AECMA-Members. It has been technicallyapprovedby the experts of the concerned AECMA Commission following comment by the Member countries. Subseque
4、nt to the publication of this pre-standard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of the standard. After examination and signature of the AECMA Standard Checking Centre (NPS) and formal agree
5、ment of the OfficiaiServices of the Member countries it will be submitted as a draft European Standard to CEN (European Committee for Standardization) for final vote. - -. :AECMA PREN3LL17 87 W LOL33LL aaoiqLY0- Previous page is blank Issue P 1 prEN3149 Page 3 - a o c c 1 This standard specifies the
6、 design of engine components for fitting of shank nuts as per EN2910 and EN2911. The shank nuts are made from the material EN2399 (A286). Scope and field of application 2 References EN2399, Heat resisting steel FE-PA92HT - Rm - 900 MPa - Bars for forged bolts D - 25 mm - Aerospace series EN2910, Aer
7、ospace series - Shank nuts, self locking, flange restrained, in heat resisting steel FE-PA92HT (A286) unplated - Classification : 1100 MPa /65OoC EN2911, Aerospace series - Shank nuts, self locking, flange restrained, in heat resisting steel FE-PA9ZHT (A286) silver plated - Classification : 1100 MPa
8、/650C Aerospace series - Self locking shank nuts - Installation procedure 1) EN3148, 3 Principles Self-locking shank nuts are parts which are secured axially by swaging an extended shank into a tapered bore. The self-locking property is achieved by way of the deformation of the first few threads. Th
9、e nuts are prevented from turning by a step in the component flange on one side (see figure i). Abutment to prevent turning i t Mounting flange C qmponent Nut riveted flange into the component Figure 1 4 Design instructions 4.1 Use Shank nuts are used for bolted joints which are only accessible from
10、 one side and where high-temperature, self-locking, double-hex head nuts cannot be used. With highly stressed components, shank nuts shall be avoided since the corner radius of the abutment shoulder is smaller than recommended. It is a stress increasing characteristic. 4.2 Flange design 4.2.1 Compon
11、ent flange The holes for the shank nuts shall be designed as per the dimensions in table 1. The dimensions and the 60 countersink ensure that the expansion of the shank on riveting-in is between 10% and 20%, which should guarantee adequate safety but prevent excessive expansion. i) In preparation. I
12、 AECNA PREN3L99 ? mp10L23LL 0004920 ? m Issue P 1 prEN3149 Page 4 Incorrect mating can lead to interference between the chamfer on tlle nut and the radius of the component flange during tightening. For this reason, the radius shall always be R1 + 0,l. Because of the small abutment face on the front
13、end of the nut, the strength of the component flange shall be suited to the pressure of the nut during tightening. It is recommended that the designer shall select the thickness of the component flange on the basis of the minimum structural requirements. However, this shall not be less than dimensio
14、n “E“ in table 1. Table 1 is illustrated by figures 2, 3, 4 and 5. 0B Table 1 - Hole dimensions I Figure 2 Dimensions in mm. Diameter B C D K(1) M min Thread size code L +0,1 +0,4 +0,2 Emin Fmin +o, 2 i) O O -0,l O MJ 50,80 - 4H6H 050 1,8 6,5 7,55 1 2 7,8 4,95 100 MJ 61,00 - 4H5H 060 1,8 7,5 8,55 1
15、2 8,8 5,45 120 MJ 7100 - 4H5H 070 2,8 8,5 9,55 1,8 3,O 10 5,95 150 MJ 81,00 - 4H5H 080 3,2 9,5 10,55 1,9 3,5 11,5 6,45 170 (i) The dimensions K and M1 are for recommendation only. 4.2.2 Securing the shank nut Shank nuts are prevented from turning by an abutment. Dimension K should be observed for ma
16、chined abutment surfaces (see table 1 and figures 3, 4 and 5). Dimensions M and M1 are derived from pitch circle diameters C and G1 using the formulae. see table i) (Mlmin The tolerance assigned to diameter M (or diameter Mi) shall take into account the run-out tolerance of diameter M (or diameter M
17、i) and the positional tolerance of diameter G. The sum of this tolerance shall not exceed 0,4 mm. ,AECMA PREN34L19 87 l10L23L_oooL+9219 Issue P 1 prEN3149 Page 5 Figure 3 Nomina clearance 0,2 F- LNomnol clearance 0,2 Figure 4 - Inner flange Figure 5 - Outer flange 5 Assembly Assembled as per EN3148.
18、 6 Drawing callout 0. Apart from the general dimensional data, the holes for shank nuts should also have a positional tolerance, The fitted nut shall be represented next to this. For swaging procedure callout, see figure 8, an example of a drawing entry. AECflApP-REN31!4Y 87 1012311 0004922 O Issue P 1 prEN3149 Page 6 SECTION YY N 81 I LRI*O,l I REPEATEO SECTION YY 1 I .a j NUT EN2911-050 ASSEMBLED TO EN3148 I L Figure 8 - Example of a drawing entry e
