1、BRITISH STANDARD BS7855-1: 1996 Metric rivets for the attachment of friction linings Part1: Specification for semi-tubular rivets ICS 21.060.40BS7855-1:1996 This BritishStandard, having been prepared under the directionof the Engineering SectorBoard, was published underthe authority of the Standards
2、 Board and comesintoeffect on 15May1996 BSI03-2000 The following BSI references relate to the work on this standard: Committee reference FME/6 Draft for comment95/707477 DC ISBN 0 580 25593 X Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted to Tec
3、hnical Committee FME/6, Rivets, upon which the following bodies were represented: British Friction Materials Council British Industrial Fasteners Federation British Steel Industry (Wire Section) Institution of Structural Engineers Ministry of Defence National Association of Fastener Stockholders Soc
4、iety of Motor Manufacturers and Traders Ltd. Amendments issued since publication Amd. No. Date CommentsBS7855-1:1996 BSI 03-2000 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Normative references 1 3 Definitions and symbols 1 4 Dimensions 1 5 Characteristics 1 6 M
5、arking 3 7 Designation for the purpose of an inquiry or order 3 Annex A (informative) Recommendations for rivet hole dimensions 5 Annex B (informative) Recommendations for semi-tubular friction rivetclenching 6 Annex C (informative) Recommendations for friction lining assembliesbeingreconditioned fo
6、r further service use 8 Figure 1 Dimensions of friction lining rivets 4 Figure A.1 Dimensions of rivet holes in friction linings 5 Figure A.2 Dimensions of rivet holes in support components 6 Figure B.1 Rivet before clenching 7 Figure B.2 Rivet after clenching 7 Table 1 Dimensions and nominal length
7、s 2 Table 2 Specifications for materials 3 Table B.1 Rivet clenching conditions 6 List of references Inside back coverBS7855-1:1996 ii BSI 03-2000 Foreword This Part of BS7855 has been prepared by Technical Committee FME/6. It specifies requirements to be met by semi-tubular rivets for use in the as
8、sembly of friction linings and support components for automotive and industrial use. Recommendations are included for associated components (both new and reconditioned) as well as for the assembled rivet condition and dimensions. The component sizes and tolerances recommended take into account both
9、the need for adequate friction material clearance to avoid assembly damage and the effect of geometric positional tolerances in multi-hole components. The recommendations made for the form and condition of the rivet clench are to ensure that the friction lining and support component are held firmly
10、in contact after assembly with an adequate grip on each item. Problems encountered in the past have, in many instances, been caused by either an incorrect relationship of the rivet/friction lining/support component clearances or an inadequate rivet clench, the most dangerous aspect being the uncontr
11、olled enlargement of support component rivet holes when friction linings are replaced. A combination of these deficiencies is likely to lead to early assembly failure and break-up of the friction lining, with serious consequences for operational safety. The recommendations contained in Annex AAnnex
12、C should help to minimize the potential problems associated with the inadequate control of either the dimensions of friction linings and support components being used, or the assembly technique employed when manufacturing or reconditioning friction lining assemblies. BS3575:1963 which specifies rive
13、ts for the attachment of friction linings (inchsizes) has been declared obsolescent and its use for new designs is not recommended. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Com
14、pliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have
15、had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS7855-1:1996 BSI 03-2000 1 1 Scope This Part of BS7855 specifies the dimensions and materials for semi-tubular rivets with nominal diameters from3mm up to and including10mm for the attachment of fri
16、ction linings to support components for use in automotive or industrial applications. Rivets conforming to this standard are suitable for automatic or hand fed riveting systems. Annex A gives recommendations for the dimensional tolerances that are applicable to the rivet holes in friction linings an
17、d support components assembled together with rivets conforming to this standard. Annex B gives recommendations for the rivet clench conditions and dimensions that are applicable to installed rivets. Annex C gives recommendations that should be applied when riveted friction lining assemblies are reco
18、nditioned for further service use. 2 Normative references This Part of BS7855 incorporates, by dated or undated reference, provisions from other publications. These normative references are made at the appropriate places in the text and the cited publications are listed on the inside back cover. For
19、 dated references, only the edition cited applies; any subsequent amendments to or revisions of the cited publication apply to this standard only when incorporated in the reference by amendment or revision. For undated references, the latest edition of the cited publication applies, together with an
20、y amendments. 3 Definitions and symbols 3.1 Definitions For the purpose of this Part of BS7855, the following definitions apply. 3.1.1 head upset portion of the rivet 3.1.2 radius part of the rivet that joins the shank to the head smoothly 3.1.3 shank part of the rivet that extends from the undersid
21、e of the head to the end of the rivet; its cross-section is essentially round 3.1.4 tube hollow section of the rivet shank at the opposite end to the head. The internal end of the tube is either flat or countersunk in form 3.1.5 length dimension measured from the top of the head to the end of the ri
22、vet 3.1.6 plain condition condition of the rivet after the removal of any lubricants used in the forming process 3.1.7 support components component onto which the friction lining is assembled in order to apply operational forces between the friction lining and opposing component 3.2 Symbols 4 Dimens
23、ions The dimensions of semi-tubular friction lining rivets shall be as given in Table 1 and Figure 1. 5 Characteristics The specifications for materials of semi-tubular friction lining rivets shall be as given in Table 2. Rivets shall be supplied in the plain condition. NOTEA variety of finishes are
24、 available for special applications by agreement between the purchaser and manufacturer. These are outside the scope of this standard. Acceptance criteria shall be as given in BS6587:1985 and ISO3269:1988. c head thickness d i clench diameter d k head diameter d s shank diameter d y inside diameter
25、of tube l length l x maximum allowable depth of the point in countersunk tubes l y depth of parallel part of tube r radiusBS7855-1:1996 2 BSI 03-2000 Table 1 Dimensions and nominal lengths Dimensions in millimetres Nominal diameter 3 3.5 4 5 6 8 10 Code reference P R T U V W X d s a max. min. 3 2.9
26、3.5 3.38 4 3.88 5 4.88 6 5.88 8 7.85 10 9.85 d k max. min. 6 5.52 7 6.42 8 7.42 10 9.42 12 11.3 16 15.3 20 19.16 c max. 0.36 0.42 0.48 0.5 0.72 0.96 1.20 r max. min. 0.6 0.4 0.6 0.4 0.6 0.4 0.8 0.6 0.8 0.6 0.8 0.6 0.8 0.6 d y max. min. 2.34 2.20 2.64 2.50 3.04 2.90 4.0 3.7 4.6 4.3 6.0 5.7 7.36 7.0 l
27、 y max. min. 3.5 3.0 3.7 3.2 4.1 3.6 5.2 4.4 6.0 5.2 7.1 6.3 7.8 7.0 l x b 3.7 4.0 4.5 5.5 6.5 8.0 9.0 l nominal l maximum l minimum 5 5.2 4.8 6 6.2 5.8 7 7.2 6.8 8 8.2 7.8 9 9.2 8.8 10 10.2 9.8 11 11.2 10.8 12 12.2 11.8 14 14.2 13.8 16 16.3 15.7 18 18.3 17.7 20 20.3 19.7 22 22.3 21.7 24 24.3 23.7 2
28、6 26.3 25.7 28 28.3 27.7 30 30.4 29.6 33 33.4 32.6 36 36.4 35.6 40 40.4 39.6 a For rivets where l 2d s , waisting of the rivet shank is permitted, seeFigure 1. b l xshall not exceed l nominal 2.BS7855-1:1996 BSI 03-2000 3 Table 2 Specifications for materials 6 Marking An embossed or indented marking
29、 on the head of a semi-tubular rivet shall be used to identify the size of each rivet. The marking shall comprise: a) the code reference for the rivet shank diameter, seeTable 1; b) the nominal length in millimetres, seeTable 2. Example The head marking of a semi-tubular friction lining rivet with s
30、hank diameter4mm and nominal length10mm is as follows. 7 Designation for the purpose of an enquiry or order When designating for the purpose of an enquiry or order, the following information shall be given: a) material (seeTable 2); b) the general product description, i.e.semi-tubular friction linin
31、g rivet; c) the code reference of the rivet shank diameter (seeTable 1); d) the nominal length in millimetres (seeTable 1); e) the number of this BritishStandard, i.e.BS7855-1:1996 1) ; f) the details of any finish, if required, including the number of any relevant BritishStandard. Example. The desi
32、gnation of a copper semi-tubular friction lining rivet with shank diameter3.5mm and nominal length8mm is as follows: Copper semi-tubular friction lining rivet R8 conforming to BS7855-1:1996. Material Specification Steel Conforming to BS3111-1:1987 type0/1 and0/2 or equivalent Copper Conforming to BS
33、2873:1969 typeC101 or equivalent Brass Conforming to BS2873:1969 typeCZ106 or equivalent 1) Marking BS7855-1:1996 on or in relation to a product represents a manufacturers declaration of conformity, i.e.a claim by or on behalf of the manufacturer that the product meets the requirements of the standa
34、rd. The accuracy of the claim is solely the claimants responsibility. Such a declaration is not to be confused with third party certification of conformity, which may also be desirable.BS7855-1:1996 4 BSI 03-2000 Figure 1 Dimensions of friction lining rivetBS7855-1:1996 BSI 03-2000 5 Annex A (inform
35、ative) Recommendations for rivet hole dimensions A.1 Dimensions of rivet holes in friction linings (seeFigure A.1) A.1.1 The minimum diameter of the rivet hole d hbshould be d smax.+0.4mm. A.1.2 The maximum diameter of the rivet hole d hbshould be d smax.+0.6mm. A.1.3 The minimum diameter of the riv
36、et hole counterbore d jashould be d kmax.+1mm. A.1.4 The concentricity of the rivet hole to the rivet hole counterbore should be0.2mm maximum. A.1.5 The residual thickness of the friction lining material remaining under the rivet counterbore should be as follows: a) for friction lining thickness T u
37、p to and including12mm, the residual thickness should be T/3 0.15mm; b) for friction lining thickness T over12mm the residual thickness should be4mm 0.15 mm. A.1.6 The inter-relationship of rivet holes in a friction lining should be held to within0.2mm diameter of geometric centre. A.2 Dimensions of
38、 rivet holes in the support component (seeFigure A.2) A.2.1 The minimum diameter of the rivet hole in the support component d hashould be d smax.+0.2mm. A.2.2 The maximum diameter of the rivet hole in the support component d hashould be d s max.+0.4mm. A.2.3 The inter-relationship of rivet holes in
39、the support component should be held to within0.2mm diameter of geometric centre. A.2.4 To facilitate a correct rivet clench the underside of the support component may be spot faced around the rivet hole at90 to the centre line of the rivet hole to a maximum diameter of d i +5mm. NOTEThis is particu
40、larly applicable to cast support components. A.2.5 The support component design should give adequate clearance to the rear of every rivet hole to allow free access for riveting and de-riveting of the assembly. Figure A.1 Dimensions of rivet holes in friction liningsBS7855-1:1996 6 BSI 03-2000 Annex
41、B (informative) Recommendations for semi-tubular friction rivet clenching B.1 Rivet clench The rivet clench is made by forming the tube section of the rivet outwards and back in a rounded form towards the rivet head to secure the friction lining and support component between the head of the rivet an
42、d the rolled over material. The diameter of the rivet clench is denoted by the symbol d i , its height by k iand its recommended length outside the component before clenching by l i , (seeFigure B.1, Figure B.2 and Table B.1). B.2 Riveting tool The riveting tool should be designed to give the correc
43、t formation to the rivet clench. B.3 Clench contact Contact between the underside of the support component and the roll-over of the rivet clench should be greater than60% of the clench circumference. B.4 Clench quality (other than for star clenching) Splits in the rivet clench, which are visible wit
44、hout optical magnification, should be avoided. B.5 Star clenching Star clenching should be used when it is necessary to clench a semi-tubular friction lining rivet onto a friction lining, where the assembly has a friction lining attached to either side of the support component. For this method of cl
45、enching, the rivet tube is opened onto the friction lining, typically into six approximately equal parts, without the expansion of the rivet shank, using a petal riveting tool. Ideally, adjacent rivets should be inserted from opposite sides of the assembly. Table B.1 Rivet clenching dimensions Figur
46、e A.2 Dimensions of rivet holes in support components Dimensions in millimetres Nominal diameter Code references l i d i k i 3 P 2.2 4.5 0.5 3.5 R 2.5 5.3 0.6 4 T 3 6 0.70 5 U 3.5 7.5 0.85 6 V 4.5 9 1 8 W 6 12 1.3 10 X 7.5 1.3 1.6BS7855-1:1996 BSI 03-2000 7 Figure B.1 Rivet before clenching Figure B
47、.2 Rivet after clenchingBS7855-1:1996 8 BSI 03-2000 Annex C (informative) Recommendations for friction lining assemblies being reconditioned for further service use C.1 The riveted friction lining should be removed from the support component with a rivet extraction punch. The punch design should be
48、such that its diameter is slightly less than the rivet tube diameter d yand of sufficient length to remove the rivet without causing any distortion to the support component. C.2 The drilling out of rivets to effect the removal of a friction lining should be avoided, in order to preserve the dimensio
49、ns of the rivet holes in the support component and consequently improve the reliability of the reconditioned assembly. C.3 Care should be taken to avoid any punch damage to the support component resulting from the removal of the friction lining, such that the mounting surface of the support component, upon which the replacement friction lining has to be affixed, becomes locally raised around any of its rivet holes. Damage of this nature should be removed before proceeding with the attachment of any replacement friction lining. C.4
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