1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 6627:2011Internal combustion engines Piston rings Expander/segment oil-control ringsBS ISO 6627:2011 BRITISH STANDARDNational forewordThis British Standard is the UK imple
2、mentation of ISO 6627:2011.The UK participation in its preparation was entrusted to TechnicalCommittee MCE/14/-/10, RIC engines - Cylinders, pistons and rings.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include
3、 all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 62299 1ICS 43.060.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and
4、Strategy Committee on 31 August 2011.Amendments issued since publicationDate Text affectedBS ISO 6627:2011Reference numberISO 6627:2011(E)ISO 2011INTERNATIONAL STANDARD ISO6627Second edition2011-08-01Internal combustion engines Piston rings Expander/segment oil-control rings Moteurs combustion inter
5、ne Segments de piston Segments racleurs rgulateurs dhuile/Ressorts dexpansion BS ISO 6627:2011ISO 6627:2011(E) COPYRIGHT PROTECTED DOCUMENT ISO 2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or m
6、echanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www
7、.iso.org Published in Switzerland ii ISO 2011 All rights reservedBS ISO 6627:2011ISO 6627:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword iv Introduction . v 1 Scope 1 2 Normative references 1 3 Symbols and abbreviated terms 1 4 Ring types and designations . 3 4.1 Types of expander/se
8、gment oil-control rings 3 4.2 General features 4 4.3 Designation examples . 5 5 Common features 5 5.1 Expander-spacer . 5 5.2 Segment features 7 5.3 Expander/segment assembly . 10 6 Dimensions 10 7 Materials . 13 7.1 Expander-spacer . 13 7.2 Segments . 13 8 Tangential force and nominal contact press
9、ure 13 8.1 Tangential force . 13 8.2 Classes of nominal contact pressure 13 Bibliography 15 BS ISO 6627:2011ISO 6627:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). Th
10、e work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-gov
11、ernmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
12、The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vo
13、te. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 6627 was prepared by Technical Committee ISO/TC 22, Road vehicles. This second edition cancel
14、s and replaces the first edition (ISO 6627:2000), which has been technically revised. BS ISO 6627:2011ISO 6627:2011(E) ISO 2011 All rights reserved vIntroduction ISO 6627 is one of a series of International Standards dealing with piston rings for reciprocating internal combustion engines. Others are
15、 ISO 6621, ISO 6622, ISO 6623; ISO 6624, ISO 6625 and ISO 6626 (see Clause 2 and the Bibliography). The common features and dimensional tables included in ISO 6627 represent a broad range of variables. In selecting a ring type, the designer will above all need to consider the particular operating co
16、nditions. Moreover, it is essential that the designer refer to the specifications and requirements of ISO 6621-3 and ISO 6621-4 before completing the selection. BS ISO 6627:2011BS ISO 6627:2011INTERNATIONAL STANDARD ISO 6627:2011(E) ISO 2011 All rights reserved 1Internal combustion engines Piston ri
17、ngs Expander/segment oil-control rings 1 Scope This International Standard specifies the essential dimensional features of expander/segment oil-control rings, without providing a complete product description (because expander-spacer design varies from piston-ring manufacturer to piston-ring manufact
18、urer, the interaction between the manufacturer and the client will determine specific design details). This International Standard applies to expander/segment oil-control rings of nominal diameters ranging from 40 mm to 125 mm for reciprocating internal combustion engines for road vehicles and other
19、 applications. It also applies to piston rings for compressors working under analogous conditions. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the lates
20、t edition of the referenced document (including any amendments) applies. ISO 6621-2, Internal combustion engines Piston rings Part 2: Inspection measuring principles ISO 6621-3, Internal combustion engines Piston rings Part 3: Material specifications ISO 6621-4, Internal combustion engines Piston ri
21、ngs Part 4: General specifications ISO 6626, Internal combustion engines Piston rings Coil-spring-loaded oil control rings 3 Symbols and abbreviated terms For the purposes of this International Standard, the symbols and abbreviated terms in Table 1 apply. Table 1 Symbols and abbreviated terms Symbol
22、 abbreviated terms Description a1Segment radial wall thickness a8Spacer radial thickness a9Expander radial thickness a11Assembly radial thickness a14Seating tab height d1Nominal ring assembly diameter (nominal diameter) h1Nominal assembly widthBS ISO 6627:2011ISO 6627:2011(E) 2 ISO 2011 All rights r
23、eservedTable 1 (continued) Symbol abbreviated terms Description h24 Segment contact face width h9Expander width h10Segment width near inside diameter (ID), after coiling h11Segment width near outside diameter (OD), after coiling and surface treatment or plating h12Nominal segment width h13Spacer wid
24、th poNominal contact pressure pouUnit contact pressure s1Segment closed gap; stagger gap FtTangential force FtcSpecific tangential force Tab angle CR1.CR2 Chromium-plating thickness LM Piston rings with partly cylindrical machined peripheral faced LP Piston rings with lapped stripe over the whole ci
25、rcumference ES1.ES4 Types of expander/segment oil-control rings PNH High nominal pressure PNL Low nominal pressure PNM Medium nominal pressure PNR Reduced nominal pressure PNV Very high nominal pressure TT00TT30 Nominal seating tab angle NS010NS050 Nitrided surface (segment) NX003NX025 Nitrided surf
26、ace (expander-spacer) BS ISO 6627:2011ISO 6627:2011(E) ISO 2011 All rights reserved 34 Ring types and designations 4.1 Types of expander/segment oil-control rings ES1 ES2 ES3 ES4 Key 1 centring pad (optional) Figure 1 Expander/segment oil-control ring designs BS ISO 6627:2011ISO 6627:2011(E) 4 ISO 2
27、011 All rights reserved4.2 General features The expander/segment assembly shall be in accordance with Figure 2. a) Assembly b) Expander-spacer c) Segment Key 1 seating tab 2 expander-spacer ends 3 peripheral surface 4 stagger segments gaps and expander ends (all three components); stagger angle shou
28、ld be larger than 30aaFor assembly arrangement regarding tangential force, see ISO 6621-2. bSeating tab angle dimensions are defined in Table 3. NOTE This is a schematic drawing of the four spring types shown in Figure 1. Figure 2 Expander/segment assembly BS ISO 6627:2011ISO 6627:2011(E) ISO 2011 A
29、ll rights reserved 54.3 Designation examples The following are examples of piston ring designations in accordance with this International Standard. EXAMPLE 1 Expander/segment oil-control ring type ES1 (ES1) of nominal diameter d1= 90 mm (90) and nominal assembly width h1= 3 mm (3,0), with segments m
30、ade of unalloyed steel subclass 68 (MC68), a chromium-plated peripheral surface of minimum thickness 0,05 mm (CR1), and with an expander made of 16 % Cr (min.) austenitic steel, of material subclass 67 (MC67) and tangential force, Ft, according to the medium nominal contact pressure class (PNM): Pis
31、ton ring ISO 6627 - ES1-90 3,0-MC68/CR1-MC67/PNM EXAMPLE 2 Expander/segment oil-control ring type ES2 (ES2) of nominal diameter d1= 90 mm (90) and nominal assembly width h1= 2,5 mm (2,5), with segments made of 11 % Cr (min.) martensitic steel, subclass 65 (MC65), nitrided on the peripheral and insid
32、e surfaces (NS020) to a minimum depth of 0,020 mm on the peripheral surface, and with an expander made of 16 % Cr (min.) austenitic steel, of material subclass 67 (MC67), nitrided on the surface (NX), and tangential force, Ft, according to the reduced nominal contact pressure class (PNR): Piston rin
33、g ISO 6627 - ES2-90 2,5-MC65/NS020-MC67/NXPNR EXAMPLE 3 Expander/segment oil-control ring type ES3 (ES3) of nominal diameter d1= 90 mm (90) and nominal assembly width h1= 4,0 mm (4,0), with segments made of unalloyed steel subclass 68 (MC68), a chromium-plated peripheral surface of minimum thickness
34、 0,05 mm (CR1) with lapped stripe (h24) of 0,30 mm, and with an expander made of 16 % Cr (min.) austenitic steel, of material subclass 67 (MC67) and tangential force, Ft, according to the high nominal contact pressure class (PNH): Piston ring ISO 6627 - ES3-90 4,0-MC68/CR1-MC67/PNH 5 Common features
35、 5.1 Expander-spacer 5.1.1 Design considerations In order to optimize the fit of the oil ring assembly into the engine cylinder bore, the following should be considered in the design of the expander/segment oil-control rings: total circumferential deflection of the expander; piston groove depth; fea
36、tures on the lands adjacent to the oil ring groove; groove-corner radius. 5.1.2 Without surface treatment The expander-spacer without surface treatment is typically used together with chromium-plated segments (see 5.2.1). 5.1.3 Nitrided surface (NX) The expander-spacer with a nitrided surface is typ
37、ically used together with nitrided segments (see 5.2.2). BS ISO 6627:2011ISO 6627:2011(E) 6 ISO 2011 All rights reservedTable 2 Expander-spacer nitrided case Dimensions in millimetres Code Nitrided case depth Tolerance NX003 0,003+ 0,012 0 NX010 0,010 NX015 0,015NX020 0,020 NX025 0,025NOTE 1 The tol
38、erance for NX applies at the contact area between the segment internal diameter and the expander. NOTE 2 For the definition of the nitrided case depth, see ISO 6621-2. 5.1.4 Seating tab angle The expander-spacer is usually designed with the seating tabs at a slight angle. These results in side seali
39、ng between the segment and the side of the piston groove (see Figure 3). Table 3 presents the recommended tab angles. Key 1 reference plane Figure 3 Expander-spacer seating tab angle Table 3 Seating tab angle Values in degrees Code Nominal value Tolerance TT00 0 + 5 TT05 5 5 TT10 10 TT15 15TT20 20 T
40、T25 25TT30 30 NOTE Code TT00 is only applicable for ES2 type expander. BS ISO 6627:2011ISO 6627:2011(E) ISO 2011 All rights reserved 75.1.5 Expander-spacer dimensions No values are given for features a8, a9, a14, h9and h13(see Figure 2), as these dimensions depend on the expander-spacer design and s
41、hall be defined by the manufacturer. 5.2 Segment features 5.2.1 Chromium-plated peripheral surface The common features of a chromium-plated segment are shown in Figure 4, with chromium-plating thickness given in Table 4. Figure 4 Chromium-plated segment Table 4 Chromium-plating thickness Dimensions
42、in millimetres Code Thickness min. CR1 0,05CR2 0,10 5.2.2 Nitrided surface codes NS010 to NS050 The common features of a nitrided segment are shown in Figure 5. The nitriding case depth (NS010 to NS050) is specified according to its reference to the peripheral surface, inside surface or the sides of
43、 the segment (see Table 5). Figure 5 Nitrided segment BS ISO 6627:2011ISO 6627:2011(E) 8 ISO 2011 All rights reservedTable 5 Nitrided case depth Dimensions in millimetres Code Nitrided case depthaPeripheral surface min. Inside surface min. Side faces NS010 0,010 0,005nitrided surface permissible NS0
44、20 0,020 0,005 NS030 0,030 0,010NS050 0,050 0,020 a For tolerances, see ISO 6621-4.5.2.3 Segment dimensions The nominal segment width (h12) is defined as the width at the mid-point of the segment radial-wall thickness. The segment width defined near the internal diameter of the segment (h10) and the
45、 outside diameter (h11) is shown in Figure 6, while typical values are given in Table 7. Figure 6 Segment width Table 6 Typical ring width and segment width combinations Dimensions in millimetres h1h120,30 0,35 0,40 0,45 0,50 0,60 1,5 x x x 2,0 x x x 2,5 3,0 x x x 3,5 x 4,0 BS ISO 6627:2011ISO 6627:
46、2011(E) ISO 2011 All rights reserved 9Table 7 Typical segment width and segment radial wall thickness combinations Dimensions in millimetres h12a11,50 1,70 1,85 2,00 2,10 2,30 2,50 2,70 3,00 0,30 x x x x 0,35 x x x x x x 0,40 x x x x x x 0,45 x x x x x x 0,50 x x x x x x 0,60 x x x x x Table 8 Typic
47、al ring width and segment radial wall thickness combinations Dimensions in millimetres h1a11,50 1,70 1,85 2,00 2,10 2,30 2,50 2,70 3,00 1,5 x x x x 2,0 x x x x x x x 2,5 x x x x x x x 3,0 x x x x x x 3,5 4,0 Table 9 Segment width due to processing Dimensions in millimetres h12Plated segment width Ni
48、trided segment width max. max.h10h11h24h10h11a h240.30 0.34 0.36 0.20 0.34 0.33 0.20 0.35 0.39 0.41 0.25 0.39 0.38 0.25 0.40 0.44 0.46 0.25 0.44 0.43 0.25 0.45 0.49 0.51 0.25 0.49 0.48 0.25 0.50 0.54 0.56 0.30 0.54 0.53 0.30 0.60 0.64 0.66 0.30 0.64 0.63 0.30 NOTE h24is applicable only for segments
49、with specified segment contact face width. aDimension h11optional. The radial wall thickness of the segment will vary in accordance with the expander-spacer design. Common ratios d1/a1are between 45 and 20. BS ISO 6627:2011ISO 6627:2011(E) 10 ISO 2011 All rights reservedThe common tolerance for the radial wall thickness (a1) of the nitrided segments is 0,05 mm, and the chromium-plated segments CR1 and CR2, is 0,08 mm. For lapped conta
