1、BSI Standards PublicationBS ISO 6621-4:2015Internal combustion engines Piston ringsPart 4: General specificationsBS ISO 6621-4:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 6621-4:2015. It supersedes BS ISO 6621-4:2003 which is withdrawn.The UK participa
2、tion 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 all the necessaryprovisions of a contract.
3、 Users are responsible for its correctapplication. The British Standards Institution 2015. Published by BSI Standards Limited 2015ISBN 978 0 580 74522 5ICS 43.060.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority
4、 of theStandards Policy and Strategy Committee on 31 March 2015.Amendments/corrigenda issued since publicationDate Text affectedBS ISO 6621-4:2015 ISO 2015Internal combustion engines Piston rings Part 4: General specificationsMoteurs combustion interne Segments de piston Partie 4: Spcifications gnra
5、lesINTERNATIONAL STANDARDISO6621-4Third edition2015-03-15Reference numberISO 6621-4:2015(E)BS ISO 6621-4:2015ISO 6621-4:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilize
6、d otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright o
7、fficeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 6621-4:2015ISO 6621-4:2015(E) ISO 2015 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and def
8、initions . 14 Piston ring codes 15 Designation of piston rings 45.1 Designation elements and order . 45.2 Designation examples . 56 Marking of piston rings . 66.1 General . 66.2 Mandatory topside identification marking . 66.3 Additional marking . 77 General characteristics 77.1 Ring shape . 77.2 Lig
9、ht tightness . 87.3 Closed gap . 87.4 Tangential force, Ft, and diametral force, Fd, of single piece piston rings 87.5 Tangential force Ftof multipiece oil control rings as specified in ISO 6626-1, ISO 6626-2, and ISO 6626-3 127.6 Tangential force Ftof expander/segment oil control rings as specified
10、 in ISO 6627 .138 Notches for preventing ring rotation .138.1 Ring joint with internal notch (only for compression rings as specified in ISO 6622 and ISO 6624) 138.2 Ring joint with side notch (only for compression rings as specified in ISO 6622) .159 Machining of surfaces .169.1 Peripheral surfaces
11、 . 169.2 Side faces . 169.3 Other surfaces . 1610 Plated, coated, and treated surfaces .1710.1 Chromium plating on peripheral surfaces . 1710.2 Spray coated peripheral surfaces . 2010.3 Nitrided surfaces 2410.4 Treated surfaces 2510.5 Physical vapour deposition coating (PVD) 2611 Miscellaneous .2711
12、.1 Cleanliness . 2711.2 Corrosion protection . 2711.3 Packaging 2712 Traceability (optional) 27Bibliography .28BS ISO 6621-4:2015ISO 6621-4:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of
13、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-governmental,
14、 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.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/
15、IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility
16、 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. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of paten
17、t declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as informa
18、tion about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information.The committee responsible for this document is ISO/TC 22, Road vehicles.This third edition cancels and replaces the second edition (ISO 6621-4:2003), wh
19、ich has been technically revised.ISO 6621 consists of the following parts, under the general title Internal combustion engines Piston rings: Part 1: Vocabulary Part 2: Inspection measuring principles Part 3: Material specifications Part 4: General specifications Part 5: Quality requirementsiv ISO 20
20、15 All rights reservedBS ISO 6621-4:2015ISO 6621-4:2015(E)IntroductionISO 6621 is one of a series of International Standards dealing with piston rings for reciprocating internal combustion engines. Others are ISO 6622-1, ISO 6622-2, ISO 6623, ISO 6624-1, ISO 6624-2, ISO 6624-3, ISO 6624-4, ISO 6625,
21、 ISO 6626-1, ISO 6626-2, ISO 6626-3, and ISO 6627. ISO 2015 All rights reserved vBS ISO 6621-4:2015BS ISO 6621-4:2015Internal combustion engines Piston rings Part 4: General specifications1 ScopeThis part of ISO 6621 specifies the general characteristics of piston rings for reciprocating internal co
22、mbustion engines for road vehicles and other applications (the individual dimensional criteria for these rings are given in the relevant International Standards). It also provides a system for ring coding, designation, and marking. It is applicable to all such rings of a nominal diameter from 30 mm
23、up to and including 200 mm.2 Normative referencesThe 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 doc
24、ument (including any amendments) applies.ISO 6507-3, Metallic materials Vickers hardness test Part 3: Calibration of reference blocksISO 6621-1, Internal combustion engines Piston rings Part 1: VocabularyISO 6621-2, Internal combustion engines Piston rings Part 2: Inspection measuring principles3 Te
25、rms and definitionsFor the purposes of this document, the terms and definitions given in ISO 6621-1 apply.4 Piston ring codesCodes used for piston rings shall be as given in Table 1, corresponding to their explanatory descriptions.Table 1 Codes and descriptions in alphabetical orderCode DescriptionR
26、elevant International StandardB Barrel-faced rectangular ring ISO 6622-1, ISO 6622-2BA Asymmetrical barrel-faced rectangular ring ISO 6622-1, ISO 6622-2CR1E . CR2E Peripheral surface chromium plated semi-inlaid design ISO 6621-4CR1F . CR2F Peripheral surface chromium plated inlaid design ISO 6621-4C
27、RF . CR4 Peripheral surface chromium plated fully faced design ISO 6621-4CSN, CSG, CSE Type of coil spring ISO 6626-1, ISO 6626-2D Bevelled edge oil control ring ISO 6625D22 Radial wall thickness for “d1/22” ISO 6622-1, ISO 6623aMaterial mark (for alternative materials) at the discretion of the manu
28、facturer.bAny other additional marking on customers request, which shall be quoted clearly in the order, shall be agreed upon between manufacturer and customer.INTERNATIONAL STANDARD ISO 6621-4:2015(E) ISO 2015 All rights reserved 1BS ISO 6621-4:2015ISO 6621-4:2015(E)Code DescriptionRelevant Interna
29、tional StandardDSF Coil spring loaded bevelled edge oil control ring ISO 6626-1, ISO 6626-2DSF-C Coil spring loaded bevelled edge oil control ring, chromium plated, and profile groundISO 6626-1, ISO 6626-2DSF-CNP Coil spring loaded bevelled edge oil control ring, chromium plated, not profile groundI
30、SO 6626-1DSF-NG Coil spring loaded bevelled edge oil control ring (face geometry similar type DSF-C or DSF-CNP)ISO 6626-1DV Bevelled edge V-groove oil control ring ISO 6625E Scraper ring (stepped) ISO 6623EM1 . EM4 Scraper ring (stepped), taper-faced ISO 6623ES-1 . ES-4 Expander/segment oil control
31、rings ISO 6627FE Ferro oxided on all sides ISO 6621-4G Double bevelled oil control ring ISO 6625GSF Coil spring loaded double bevelled oil control ring ISO 6626-1, ISO 6626-2HK Straight faced half keystone ring 7 ISO 6624-2, ISO 6624-4HKB Barrel faced half keystone ring 7 ISO 6624-2, ISO 6624-4HKBA
32、Asymmetrical barrel-faced half keystone ring ISO 6624-2, ISO 6624-4HOL Openings in oil rings in form of holes ISO 6626-2IF Internal bevel (top side) ISO 6622, ISO 6624-1, ISO 6624-3IFU Internal bevel (bottom side) ISO 6622IFV Variable internal bevel (top side) for defined twist ISO 6622-1IFVU Variab
33、le internal bevel (bottom side) for defined twist ISO 6622-1IW Internal step (top side) ISO 6622-1, ISO 6624-1IWU Internal step (bottom side) ISO 6622-1K Straight-faced keystone ring 15 ISO 6624-1, ISO 6624-3KA Peripheral edges chamfered ISO 6622KB Barrel-faced keystone ring 15 ISO 6624-1, ISO 6624-
34、3KBA Asymmetrical barrel-faced keystone ring 15 ISO 6624-1, ISO 6624-3KG Reduced size of peripheral edges at the gap of chromium plated/spray coated/nitrided/PVD coated ringsISO 6621-4KI Inside edges chamfered ISO 6622KM1 . KM5 Taper-faced keystone ring 15 ISO 6624-1, ISO 6624-3KU Reduced peripheral
35、 bottom edge chromium plated fully faced designISO 6621-4LF Uncoated ring peripheral surface or uncoated land peripheral surface, fully lappedISO 6621-4LM Taper-faced piston ring with partly cylindrical machined peripheral surfaceISO 6621-4aMaterial mark (for alternative materials) at the discretion
36、 of the manufacturer.bAny other additional marking on customers request, which shall be quoted clearly in the order, shall be agreed upon between manufacturer and customer.Table 1 (continued)2 ISO 2015 All rights reservedBS ISO 6621-4:2015ISO 6621-4:2015(E)Code DescriptionRelevant International Stan
37、dardLP Taper-faced piston ring with lapped land over the whole circumference but not over the whole width of the peripheral surfaceISO 6621-4M1 .M5 Taper-faced rectangular ring ISO 6622-1, ISO 6622-2MC11 . MC68 Material subclasses ISO 6621-3MM Manufacturers mark ISO 6621-4MRReduced ratio m da11() fo
38、r reduced loadISO 6621-4MU Any other additional markbISO 6621-4MX Material markaISO 6621-4MY Mark for required ring shape “negative ovality” ISO 6621-4MZ Mark for required ring shape “round” ISO 6621-4N Napier ring (undercut step) ISO 6623NB030 . NB130 Nitrided surface, case depth specified on perip
39、heral surface and bottom sideISO 6621-4NE1 . NE3 Ring joint with lateral stop ISO 6621-4NH1 . NH3 Ring joint with internal stop ISO 6621-4NM1 . NM4 Napier ring (undercut step), taper-faced ISO 6623NP030 . NP130 Nitrided surface, case depth specified on peripheral surface onlyISO 6621-4NS 010 . NS 05
40、0 Nitrided surface, case depth on segments ISO 6627NT030 . NT130 Nitrided surface, case depth specified on peripheral surface and side facesISO 6621-4NX Nitrided surface of expanders/spacers ISO 6627PC001PC040 Physical vapour deposition coating (PVD) thickness ISO 6621-4PN 10PN 25 Nominal contact pr
41、essure classes ISO 6626-3PNE, PNL, PNR, PNM, PNH, PNVContact pressure class ISO 6626-1, ISO 6626-2, ISO 6627PO Phosphated on all sides ISO 6621-4PR Phosphated on all sides (for rust protection purposes) ISO 6621-4R Straight-faced rectangular ring ISO 6622-1, ISO 6622-2RU Napier ring with reduced und
42、ercut or step ISO 6623S Slotted oil control ring ISO 6625S005 . S100 Closed gap (minimum values) ISO 6621-4SC1 . SC4 Peripheral surface spray coated fully faced design ISO 6621-4SC1E . SC4E Peripheral surface spray coated semi-inlaid design ISO 6621-4SC1F . SC4F Peripheral surface spray coated inlai
43、d design ISO 6621-4SSF Coil spring loaded slotted oil control ring ISO 6626-1, ISO 6626-2SSF-L Coil spring loaded slotted oil control ring with 0,6 mm nominal land widthISO 6626-1, ISO 6626-2aMaterial mark (for alternative materials) at the discretion of the manufacturer.bAny other additional markin
44、g on customers request, which shall be quoted clearly in the order, shall be agreed upon between manufacturer and customer.Table 1 (continued) ISO 2015 All rights reserved 3BS ISO 6621-4:2015ISO 6621-4:2015(E)Code DescriptionRelevant International StandardT Straight-faced keystone ring 6 ISO 6624-1,
45、 ISO 6624-3TB Barrel-faced keystone ring 6 ISO 6624-1, ISO 6624-3TBA Asymmetrical barrel-faced keystone ring 6 ISO 6624-1, ISO 6624-3TM1 . TM5 Taper-faced keystone ring 6 ISO 6624-1, ISO 6624-3TT Seating tab angle ISO 6627WF Reduced heat set ISO 6621-5, ISO 6626-1, ISO 6626-2WK Reduced slot length I
46、SO 6626-1, ISO 6626-2WTL Radial wall thickness (large) ISO 6626-3WTS Radial wall thickness (small) ISO 6626-3Y Ring shape negative ovality ISO 6621-4Z Ring shape round ISO 6621-4aMaterial mark (for alternative materials) at the discretion of the manufacturer.bAny other additional marking on customer
47、s request, which shall be quoted clearly in the order, shall be agreed upon between manufacturer and customer.5 Designation of piston rings5.1 Designation elements and order5.1.1 GeneralWhen designating piston rings complying with the relevant International Standards, the following details shall be
48、provided in the order given, using the codes according to Table 1.5.1.2 Mandatory elementsThe following mandatory elements shall constitute the designation of a piston ring: designation (i.e. piston ring); number of International Standard; type of piston ring (e.g. R); hyphen; size of piston ring, d
49、1 h1; radial wall thickness “regular” without code; Code D22 if the selected wall thickness, in accordance with ISO 6622-1 and ISO 6623, is d1/22; hyphen; material code (e.g. MC11).Table 1 (continued)4 ISO 2015 All rights reservedBS ISO 6621-4:2015ISO 6621-4:2015(E)5.1.3 Additional elementsThe following optional elements may be added to the designation of a piston ring and, if so added, shall be positioned on a second line beneath or separated by a slash (/) from the mandatory elements given
