1、BSI Standards Publication BS ISO 6621-4:2015 Internal combustion engines Piston rings Part 4: General specificationsBS ISO 6621-4:2015 BRITISH STANDARD National foreword This British Standard is the UK implementation of ISO 6621-4:2015. It supersedes BS ISO 6621-4:2003 which is withdrawn. The UK par
2、ticipation 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 purport to include all the necessary provisions of
3、a contract. Users are responsible for its correct application. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 74522 5 ICS 43.060.10 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published un
4、der the authority of the Standards Policy and Strategy Committee on 31 March 2015. Amendments/corrigenda issued since publication Date Text affectedBS ISO 6621-4:2015 ISO 2015 Internal combustion engines Piston rings Part 4: General specifications Moteurs combustion interne Segments de piston Partie
5、 4: Spcifications gnrales INTERNATIONAL STANDARD ISO 6621-4 Third edition 2015-03-15 Reference number ISO 6621-4:2015(E)BS ISO 6621-4:2015ISO 6621-4:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015 All rights reserved. Unless otherwise specified, no part of this publicati
6、on may be reproduced or utilized 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 o
7、f 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.iso.org Published in SwitzerlandBS ISO 6621-4:2015ISO 6621-4:2015(E) ISO 2015 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope
8、. 1 2 Normative references 1 3 Terms and definitions . 1 4 Piston ring codes 1 5 Designation of piston rings 4 5.1 Designation elements and order . 4 5.2 Designation examples . 5 6 Marking of piston rings . 6 6.1 General . 6 6.2 Mandatory topside identification marking . 6 6.3 Additional marking . 7
9、 7 General characteristics 7 7.1 Ring shape . 7 7.2 Light tightness . 8 7.3 Closed gap . 8 7.4 Tangential force, F t , and diametral force, F d , of single piece piston rings 8 7.5 Tangential force F tof multipiece oil control rings as specified in ISO 6626-1, ISO 6626-2, and ISO 6626-3 12 7.6 Tange
10、ntial force F tof expander/segment oil control rings as specified in ISO 6627 .13 8 Notches for preventing ring rotation .13 8.1 Ring joint with internal notch (only for compression rings as specified in ISO 6622 and ISO 6624) 13 8.2 Ring joint with side notch (only for compression rings as specifie
11、d in ISO 6622) .15 9 Machining of surfaces .16 9.1 Peripheral surfaces .16 9.2 Side faces .16 9.3 Other surfaces .16 10 Plated, coated, and treated surfaces .17 10.1 Chromium plating on peripheral surfaces .17 10.2 Spray coated peripheral surfaces .20 10.3 Nitrided surfaces 24 10.4 Treated surfaces
12、25 10.5 Physical vapour deposition coating (PVD) 26 11 Miscellaneous .27 11.1 Cleanliness .27 11.2 Corrosion protection .27 11.3 Packaging 27 12 Traceability (optional) 27 Bibliography .28BS ISO 6621-4:2015ISO 6621-4:2015(E) Foreword ISO (the International Organization for Standardization) is a worl
13、dwide federation of national standards 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
14、that committee. International organizations, 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. The procedures used to develop this d
15、ocument and those intended for its further maintenance are described in the ISO/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 Direc
16、tives, Part 2 (see www.iso.org/directives). 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. Details of any patent rights identified during the develo
17、pment of the document will be in the Introduction and/or on the ISO list of patent 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
18、specific terms and expressions related to conformity assessment, as well as information 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 vehic
19、les. This third edition cancels and replaces the second edition (ISO 6621-4:2003), which 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: Materi
20、al specifications Part 4: General specifications Part 5: Quality requirementsiv ISO 2015 All rights reservedBS ISO 6621-4:2015ISO 6621-4:2015(E) Introduction ISO 6621 is one of a series of International Standards dealing with piston rings for reciprocating internal combustion engines. Others are ISO
21、 6622-1, ISO 6622-2, ISO 6623, ISO 6624-1, ISO 6624-2, ISO 6624-3, ISO 6624-4, ISO 6625, 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 specifications 1 Scope This part of IS
22、O 6621 specifies the general characteristics of piston rings for reciprocating internal combustion 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, desi
23、gnation, and marking. It is applicable to all such rings of a nominal diameter from 30 mm up to and including 200 mm. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only
24、 the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 6507-3, Metallic materials Vickers hardness test Part 3: Calibration of reference blocks ISO 6621-1, Internal combustion engines Piston rings Part 1: Vocabulary I
25、SO 6621-2, Internal combustion engines Piston rings Part 2: Inspection measuring principles 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 6621-1 apply. 4 Piston ring codes Codes used for piston rings shall be as given in Table 1, corresponding to t
26、heir explanatory descriptions. Table 1 Codes and descriptions in alphabetical order Code Description Relevant International Standard B Barrel-faced rectangular ring ISO 6622-1, ISO 6622-2 BA Asymmetrical barrel-faced rectangular ring ISO 6622-1, ISO 6622-2 CR1E . CR2E Peripheral surface chromium pla
27、ted semi-inlaid design ISO 6621-4 CR1F . CR2F Peripheral surface chromium plated inlaid design ISO 6621-4 CRF . CR4 Peripheral surface chromium plated fully faced design ISO 6621-4 CSN, CSG, CSE Type of coil spring ISO 6626-1, ISO 6626-2 D Bevelled edge oil control ring ISO 6625 D22 Radial wall thic
28、kness for “d1/22” ISO 6622-1, ISO 6623 aMaterial mark (for alternative materials) at the discretion 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. INTERNATIONAL ST ANDARD ISO
29、 6621-4:2015(E) ISO 2015 All rights reserved 1BS ISO 6621-4:2015ISO 6621-4:2015(E) Code Description Relevant International Standard DSF Coil spring loaded bevelled edge oil control ring ISO 6626-1, ISO 6626-2 DSF-C Coil spring loaded bevelled edge oil control ring, chromium plated, and profile groun
30、d ISO 6626-1, ISO 6626-2 DSF-CNP Coil spring loaded bevelled edge oil control ring, chromium plated, not profile ground ISO 6626-1 DSF-NG Coil spring loaded bevelled edge oil control ring (face geometry similar type DSF-C or DSF-CNP) ISO 6626-1 DV Bevelled edge V-groove oil control ring ISO 6625 E S
31、craper ring (stepped) ISO 6623 EM1 . EM4 Scraper ring (stepped), taper-faced ISO 6623 ES-1 . ES-4 Expander/segment oil control rings ISO 6627 FE Ferro oxided on all sides ISO 6621-4 G Double bevelled oil control ring ISO 6625 GSF Coil spring loaded double bevelled oil control ring ISO 6626-1, ISO 66
32、26-2 HK Straight faced half keystone ring 7 ISO 6624-2, ISO 6624-4 HKB Barrel faced half keystone ring 7 ISO 6624-2, ISO 6624-4 HKBA Asymmetrical barrel-faced half keystone ring ISO 6624-2, ISO 6624-4 HOL Openings in oil rings in form of holes ISO 6626-2 IF Internal bevel (top side) ISO 6622, ISO 66
33、24-1, ISO 6624-3 IFU Internal bevel (bottom side) ISO 6622 IFV Variable internal bevel (top side) for defined twist ISO 6622-1 IFVU Variable internal bevel (bottom side) for defined twist ISO 6622-1 IW Internal step (top side) ISO 6622-1, ISO 6624-1 IWU Internal step (bottom side) ISO 6622-1 K Strai
34、ght-faced keystone ring 15 ISO 6624-1, ISO 6624-3 KA Peripheral edges chamfered ISO 6622 KB Barrel-faced keystone ring 15 ISO 6624-1, ISO 6624-3 KBA Asymmetrical barrel-faced keystone ring 15 ISO 6624-1, ISO 6624-3 KG Reduced size of peripheral edges at the gap of chromium plated/spray coated/nitrid
35、ed/PVD coated rings ISO 6621-4 KI Inside edges chamfered ISO 6622 KM1 . KM5 Taper-faced keystone ring 15 ISO 6624-1, ISO 6624-3 KU Reduced peripheral bottom edge chromium plated fully faced design ISO 6621-4 LF Uncoated ring peripheral surface or uncoated land peripheral surface, fully lapped ISO 66
36、21-4 LM Taper-faced piston ring with partly cylindrical machined peripheral surface ISO 6621-4 aMaterial mark (for alternative materials) at the discretion of the manufacturer. bAny other additional marking on customers request, which shall be quoted clearly in the order, shall be agreed upon betwee
37、n manufacturer and customer.Table 1 (continued) 2 ISO 2015 All rights reservedBS ISO 6621-4:2015ISO 6621-4:2015(E) Code Description Relevant International Standard LP Taper-faced piston ring with lapped land over the whole circumference but not over the whole width of the peripheral surface ISO 6621
38、-4 M1 .M5 Taper-faced rectangular ring ISO 6622-1, ISO 6622-2 MC11 . MC68 Material subclasses ISO 6621-3 MM Manufacturers mark ISO 6621-4 MR Reduced ratio 11 for reduced load ISO 6621-4 MU Any other additional mark b ISO 6621-4 MX Material mark a ISO 6621-4 MY Mark for required ring shape “negative
39、ovality” ISO 6621-4 MZ Mark for required ring shape “round” ISO 6621-4 N Napier ring (undercut step) ISO 6623 NB030 . NB130 Nitrided surface, case depth specified on peripheral surface and bottom side ISO 6621-4 NE1 . NE3 Ring joint with lateral stop ISO 6621-4 NH1 . NH3 Ring joint with internal sto
40、p ISO 6621-4 NM1 . NM4 Napier ring (undercut step), taper-faced ISO 6623 NP030 . NP130 Nitrided surface, case depth specified on peripheral surface only ISO 6621-4 NS 010 . NS 050 Nitrided surface, case depth on segments ISO 6627 NT030 . NT130 Nitrided surface, case depth specified on peripheral sur
41、face and side faces ISO 6621-4 NX Nitrided surface of expanders/spacers ISO 6627 PC001PC040 Physical vapour deposition coating (PVD) thickness ISO 6621-4 PN 10PN 25 Nominal contact pressure classes ISO 6626-3 PNE, PNL, PNR, PNM, PNH, PNV Contact pressure class ISO 6626-1, ISO 6626-2, ISO 6627 PO Pho
42、sphated on all sides ISO 6621-4 PR Phosphated on all sides (for rust protection purposes) ISO 6621-4 R Straight-faced rectangular ring ISO 6622-1, ISO 6622-2 RU Napier ring with reduced undercut or step ISO 6623 S Slotted oil control ring ISO 6625 S005 . S100 Closed gap (minimum values) ISO 6621-4 S
43、C1 . SC4 Peripheral surface spray coated fully faced design ISO 6621-4 SC1E . SC4E Peripheral surface spray coated semi-inlaid design ISO 6621-4 SC1F . SC4F Peripheral surface spray coated inlaid design ISO 6621-4 SSF Coil spring loaded slotted oil control ring ISO 6626-1, ISO 6626-2 SSF-L Coil spri
44、ng loaded slotted oil control ring with 0,6 mm nominal land width ISO 6626-1, ISO 6626-2 aMaterial mark (for alternative materials) at the discretion of the manufacturer. bAny other additional marking on customers request, which shall be quoted clearly in the order, shall be agreed upon between manu
45、facturer and customer.Table 1 (continued) ISO 2015 All rights reserved 3BS ISO 6621-4:2015ISO 6621-4:2015(E) Code Description Relevant International Standard T Straight-faced keystone ring 6 ISO 6624-1, ISO 6624-3 TB Barrel-faced keystone ring 6 ISO 6624-1, ISO 6624-3 TBA Asymmetrical barrel-faced k
46、eystone ring 6 ISO 6624-1, ISO 6624-3 TM1 . TM5 Taper-faced keystone ring 6 ISO 6624-1, ISO 6624-3 TT Seating tab angle ISO 6627 WF Reduced heat set ISO 6621-5, ISO 6626-1, ISO 6626-2 WK Reduced slot length ISO 6626-1, ISO 6626-2 WTL Radial wall thickness (large) ISO 6626-3 WTS Radial wall thickness
47、 (small) ISO 6626-3 Y Ring shape negative ovality ISO 6621-4 Z Ring shape round ISO 6621-4 aMaterial mark (for alternative materials) at the discretion of the manufacturer. bAny other additional marking on customers request, which shall be quoted clearly in the order, shall be agreed upon between ma
48、nufacturer and customer. 5 Designation of piston rings 5.1 Designation elements and order 5.1.1 General When designating piston rings complying with the relevant International Standards, the following details shall be provided in the order given, using the codes according to Table 1. 5.1.2 Mandatory
49、 elements The 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 1 h 1 ; 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 662
