1、raising standards worldwide NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BSI Standards Publication BS ISO 6627:2011 Internal combustion engines Piston rings Expander/ segment oil-control ringsBS ISO 6627:2011 BRITISH STANDARD National foreword This British Standard is the U
2、K implementation of ISO 6627:2011. The UK participation in its preparation was entrusted to Technical Committee MCE/14/-/10, RIC engines - Cylinders, pistons and rings. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purpor
3、t to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 62299 1 ICS 43.060.10 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the S
4、tandards Policy and Strategy Committee on 31 August 2011. Amendments issued since publication Date Text affectedBS ISO 6627:2011Reference number ISO 6627:2011(E) ISO 2011INTERNATIONAL STANDARD ISO 6627 Second edition 2011-08-01 Internal combustion engines Piston rings Expander/segment oil-control ri
5、ngs Moteurs combustion interne Segments de piston Segments racleurs rgulateurs dhuile/Ressorts dexpansion BS ISO 6627:2011 ISO 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
6、by any means, electronic or mechanical, 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-
7、mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2011 All rights reservedBS ISO 6627:2011 ISO 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 designation
8、s . 3 4.1 Types of expander/segment 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 f
9、orce and nominal contact pressure 13 8.1 Tangential force . 13 8.2 Classes of nominal contact pressure 13 Bibliography 15 BS ISO 6627:2011 ISO 6627:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards
10、 bodies (ISO member bodies). The 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 organiza
11、tions, governmental and non-governmental, 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 t
12、he ISO/IEC Directives, Part 2. 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
13、 the member bodies casting a vote. 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 vehic
14、les. This second edition cancels and replaces the first edition (ISO 6627:2000), which has been technically revised. BS ISO 6627:2011 ISO 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 interna
15、l combustion engines. Others are 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 cons
16、ider the particular operating conditions. 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 6627:2011 INTERNATIONAL STANDARD ISO 6627:2011(E) ISO 2011 All rights reserved 1Inte
17、rnal combustion engines Piston rings 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 man
18、ufacturer to piston-ring manufacturer, 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 en
19、gines for road vehicles and other 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.
20、For undated references, the latest 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, Inte
21、rnal combustion engines Piston rings 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 Sym
22、bols and abbreviated terms Symbol abbreviated terms Description a 1 Segment radial wall thickness a 8Spacer radial thickness a 9Expander radial thickness a 11Assembly radial thickness a 14Seating tab height d 1Nominal ring assembly diameter (nominal diameter) h 1Nominal assembly width BS ISO 6627:20
23、11 ISO 6627:2011(E) 2 ISO 2011 All rights reservedTable 1 (continued) Symbol abbreviated terms Description h 24 Segment contact face width h 9Expander width h 10Segment width near inside diameter (ID), after coiling h 11Segment width near outside diameter (OD), after coiling and surface treatment or
24、 plating h 12Nominal segment width h 13Spacer width p oNominal contact pressure p ouUnit contact pressure s 1Segment closed gap; stagger gap F tTangential force F tcSpecific tangential force Tab angle CR1.CR2 Chromium-plating thickness LM Piston rings with partly cylindrical machined peripheral face
25、d LP Piston rings with lapped stripe over the whole circumference 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 NS010NS0
26、50 Nitrided surface (segment) NX003NX025 Nitrided surface (expander-spacer) BS ISO 6627:2011 ISO 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-contro
27、l ring designs BS ISO 6627:2011 ISO 6627:2011(E) 4 ISO 2011 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
28、expander ends (all three components); stagger angle should be larger than 30 aaFor 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/seg
29、ment assembly BS ISO 6627:2011 ISO 6627:2011(E) ISO 2011 All 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 d 1= 90 mm (90)
30、 and nominal assembly width h 1= 3 mm (3,0), with segments made 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, F t , acc
31、ording to the medium nominal contact pressure class (PNM): Piston ring ISO 6627 - ES1-90 3,0-MC68/CR1-MC67/PNM EXAMPLE 2 Expander/segment oil-control ring type ES2 (ES2) of nominal diameter d 1= 90 mm (90) and nominal assembly width h 1= 2,5 mm (2,5), with segments made of 11 % Cr (min.) martensitic
32、 steel, subclass 65 (MC65), nitrided on the peripheral and inside 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, F t , accordi
33、ng to the reduced nominal contact pressure class (PNR): Piston ring ISO 6627 - ES2-90 2,5-MC65/NS020-MC67/NXPNR EXAMPLE 3 Expander/segment oil-control ring type ES3 (ES3) of nominal diameter d 1= 90 mm (90) and nominal assembly width h 1= 4,0 mm (4,0), with segments made of unalloyed steel subclass
34、68 (MC68), a chromium-plated peripheral surface of minimum thickness 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, F t , according to the high nominal contact pressure class (PNH):
35、 Piston ring ISO 6627 - ES3-90 4,0-MC68/CR1-MC67/PNH 5 Common features 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: tota
36、l circumferential deflection of the expander; piston groove depth; features 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 Ni
37、trided surface (NX) The expander-spacer with a nitrided surface is typically used together with nitrided segments (see 5.2.2). BS ISO 6627:2011 ISO 6627:2011(E) 6 ISO 2011 All rights reservedTable 2 Expander-spacer nitrided case Dimensions in millimetres Code Nitrided case depth Tolerance NX003 0,00
38、3 + 0,012 0 NX010 0,010 NX015 0,015 NX020 0,020 NX025 0,025 NOTE 1 The tolerance 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 des
39、igned with the seating tabs at a slight angle. These results in side sealing 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
40、 Code Nominal value Tolerance TT00 0 + 5 TT05 5 5 TT10 10 TT15 15 TT20 20 TT25 25 TT30 30 NOTE Code TT00 is only applicable for ES2 type expander. BS ISO 6627:2011 ISO 6627:2011(E) ISO 2011 All rights reserved 75.1.5 Expander-spacer dimensions No values are given for features a 8 , a 9 , a 14 , h 9a
41、nd h 13(see Figure 2), as these dimensions depend on the expander-spacer design and shall 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 Tab
42、le 4. Figure 4 Chromium-plated segment Table 4 Chromium-plating thickness Dimensions in millimetres Code Thickness min. CR1 0,05 CR2 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 specifie
43、d according to its reference to the peripheral surface, inside surface or the sides of the segment (see Table 5). Figure 5 Nitrided segment BS ISO 6627:2011 ISO 6627:2011(E) 8 ISO 2011 All rights reservedTable 5 Nitrided case depth Dimensions in millimetres Code Nitrided case depth aPeripheral surfa
44、ce min. Inside surface min. Side faces NS010 0,010 0,005 nitrided surface permissible NS020 0,020 0,005 NS030 0,030 0,010 NS050 0,050 0,020 a For tolerances, see ISO 6621-4.5.2.3 Segment dimensions The nominal segment width (h 12 ) is defined as the width at the mid-point of the segment radial-wall
45、thickness. The segment width defined near the internal diameter of the segment (h 10 ) and the outside diameter (h 11 ) 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 h 1h 120
46、,30 0,35 0,40 0,45 0,50 0,60 1,5 x x x 2,0 x x x 2,5 x x 3,0 x x x 3,5 x x x 4,0 x x BS ISO 6627:2011 ISO 6627:2011(E) ISO 2011 All rights reserved 9Table 7 Typical segment width and segment radial wall thickness combinations Dimensions in millimetres h 12a 11,50 1,70 1,85 2,00 2,10 2,30 2,50 2,70 3
47、,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 Typical ring width and segment radial wall thickness combinations Dimensions in millimetres h 1a 11,50 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
48、,0 x x x x x x 3,5 x x 4,0 x x Table 9 Segment width due to processing Dimensions in millimetres h 12Plated segment width Nitrided segment width max. max. h 10h 11h 24h 10h 11 a h 240.30 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 0.5
49、1 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 h 24is applicable only for segments with specified segment contact face width. aDimension h 11optional. The radial wall thickness of the segment will vary in accordance with the expander-spacer design. Common ratios d 1 /a 1are between 45 and 20. BS ISO 6627:2011 ISO 6627:2011(E) 10 ISO 2011 All rights reservedThe common tolerance for the radia
