1、BSI Standards Publication BS ISO 6621-5:2013 Internal combustion engines Piston rings Part 5: Quality requirementsBS ISO 6621-5:2013 BRITISH STANDARD National foreword This British Standard is the UK implementation of ISO 6621-5:2013. It supersedes BS ISO 6621-5:2005 which is withdrawn. The UK parti
2、cipation 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 a
3、contract. Users are responsible for its correct application. The British Standards Institution 2013. Published by BSI Standards Limited 2013 ISBN 978 0 580 69378 6 ICS 43.060.10 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published unde
4、r the authority of the Standards Policy and Strategy Committee on 30 September 2013. Amendments issued since publication Date Text affectedBS ISO 6621-5:2013 ISO 2013 Internal combustion engines Piston rings Part 5: Quality requirements Moteurs combustion interne Segments de piston Partie 5: Exigenc
5、es de qualit INTERNATIONAL STANDARD ISO 6621-5 Third edition 2013-10-01 Reference number ISO 6621-5:2013(E)BS ISO 6621-5:2013ISO 6621-5:2013(E)ii ISO 2013 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2013 All rights reserved. Unless otherwise specified, no part of this publication may be rep
6、roduced 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 of the request
7、er. 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 6621-5:2013ISO 6621-5:2013(E) ISO 2013 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normati
8、ve references 1 3 T erms and definitions . 2 4 Visible defects 2 4.1 General . 2 4.2 Pores, cavities, and sand inclusions 2 4.3 Scratches, indentations, depressions, and cracks . 3 4.4 Edges 3 4.5 Other characteristics subject to visual inspection only 10 5 Material .11 5.1 Specifications.11 5.2 Los
9、s of tangential force under temperature effects .11 6 Raised material caused by marking of rings 11 7 Machining of periphery and sides Unint entional de viation fr om ideal pr ofile and flatness .12 7.1 General 12 7.2 Permissible deviations for peripheral surface profile .12 7.3 Permissible helix 13
10、 Bibliography .14BS ISO 6621-5:2013ISO 6621-5:2013(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees.
11、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, in liaison with ISO, also take part in the work. ISO collaborates closely with the Internat
12、ional 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/IEC Directives, Part 1. In particular the different approval criteria needed for the differ
13、ent types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2. 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 b
14、e 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 patent declarations received. www.iso.org/patents Any trade name used in this document is information
15、 given for the convenience of users and does not constitute an endorsement. The committee responsible for this document is ISO/TC 22, Road vehicles. This third edition cancels and replaces the second edition (ISO 6621-5:2005), of which it constitutes a minor revision. ISO 6621 consists of the follow
16、ing 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 2013 All rights reservedBS ISO 6621-5:2013ISO 6621-5:2013(E) Intro
17、duction This International Standard is one of a number of series of International Standards dealing with piston rings for reciprocating internal combustion engines. Others are ISO 6622, ISO 6623, ISO 6624, ISO 6625, ISO 6626, and ISO 6627. The common features and dimensional tables presented in this
18、 part of ISO 6621 constitute a broad range of variables, and the designer, in selecting a particular ring type, should bear in mind the conditions under which it will be required to operate. The designer also refers to the specifications and requirements of ISO 6621-3 and ISO 6621-4 before completin
19、g his selection. The difficulty of trying to define in absolute terms the quality attainable in normal commercial manufacture of piston rings is well known. In this part of ISO 6621, the commonly encountered aspects of quality in terms of casting defects and other departures from ideal are quantifie
20、d. Many minor defects are clearly quite acceptable; other defects because of size or number are inadmissible. ISO 2013 All rights reserved vBS ISO 6621-5:2013BS ISO 6621-5:2013Internal combustion engines Piston rings Part 5: Quality requirements 1 Scope This part of ISO 6621 specifies those quality
21、aspects that are capable of definition but not normally found on a drawing specification. It is applicable to the following: single-piece piston rings of grey cast iron or steel; multi-piece piston rings (oil control rings) consisting of cast iron parts and spring components; single-piece and multi-
22、piece oil control rings of steel, i.e. oil control rings in the form of strip steel components or steel segments (rails) with spring expander components. In addition to specifying certain of the limits of acceptance relating to inspection measuring principles (covered by ISO 6621-2), this part of IS
23、O 6621 also covers those features for which no recognized quantitative measurement procedures exist and which are only checked visually with normal eyesight (spectacles if worn normally) and without magnification. Such features (superficial defects) are additional to the standard tolerances of ring
24、width, radial wall thickness, and closed gap. This part of ISO 6621 does not establish acceptable quality levels (AQL), it being left to manufacturer and client to decide the appropriate levels jointly. In this case, the recommendations of ISO 2859 are followed. This part of ISO 6621 specifies the q
25、uality requirements of piston rings for reciprocating internal combustion engines for road vehicles and other applications. 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 normati
26、vely 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 document (including any amendments) applies. ISO 6621-1, Internal combustion engines Piston rings Part 1: Voc
27、abulary ISO 6621-3, Internal combustion engines Piston rings Part 3: Material specifications ISO 6622 (all parts), Internal combustion engines Piston rings ISO 6623, Internal combustion engines Piston rings Scraper rings made of cast iron ISO 6624 (all parts), Internal combustion engines Piston ring
28、s ISO 6625, Internal combustion engines Piston rings Oil control rings ISO 6626, Internal combustion engines Piston rings Coil-spring-loaded oil control rings ISO 6626-2, Internal combustion engines Piston rings Part 2: Coil-spring-loaded oil control rings of narrow width made of cast iron INTERNATI
29、ONAL ST ANDARD ISO 6621-5:2013(E) ISO 2013 All rights reserved 1BS ISO 6621-5:2013ISO 6621-5:2013(E) ISO 6626-3, Internal combustion engines Piston rings Part 3: Coil-spring-loaded oil control rings made of steel ISO 6627, Internal combustion engines Piston rings Expander/segment oil-control rings 3
30、 T erms a nd definiti ons For the purposes of this document, the terms and definitions in ISO 6621-1 apply. 4 Visible defects 4.1 General Visible defects are divided into two principal classes as described in 4.2 to 4.5. The first class covers those defects frequently found in castings and includes
31、such defects as porosity, sand inclusions, cavities, etc. The second class of defects covers mechanical abrasions which may occur during forming, machining, or handling of the rings and includes scratches, dents, chipping, burrs, and cracks. Inspection of piston rings for such defects is generally c
32、arried out visually, without magnification, by inspectors having normal eyesight, corrected if necessary. It is not intended that every ring be rigorously inspected for size and distribution of defects, but rather that the values given in the tables and text be used as a general guide. However, in c
33、ase of doubt, the values given should be used as the means of judging the quality of the rings. 4.2 Pores, cavities, and sand inclusions Such defects are permissible on uncoated surfaces and edges provided that the values given in Table 1 for size, number, and spacing are not exceeded. Table 1 Permi
34、ssible values of size, number, and spacing of pores, cavities, and sand inclusions Dimensions in millimetres Nominal diameter d 1 Defect size max. Number of defects per ring max. Spacing of defects cmin. On peripheral surface a On other surfaces a On peripheral edges On other edges b 30 d 1 60 0,1 0
35、,3 0,1 0,1 2 4 60 d 1 100 0,15 0,5 0,1 0,2 4 4 100 d 1 150 0,2 0,5 0,1 0,3 6 8 150 d 1 200 0,2 0,8 0,1 0,4 8 8 aThe defects should not be closer to an edge than one-half of the maximum permissible size of the defect, with a minimum of 0,2. bDoes not apply to inside gap edges of piston rings with int
36、ernal notch. cSpacing includes defects on adjacent or opposite surfaces.2 ISO 2013 All rights reservedBS ISO 6621-5:2013ISO 6621-5:2013(E) 4.3 Scratches, indentations, depressions, and cracks 4.3.1 Scratches Isolated scratches are permissible provided that no burrs are produced exceeding the permiss
37、ible values given in 4.4.1.1, on turned peripheral surfaces, they are not deeper than the tool marks, on non-turned peripheral surfaces, they are not deeper than 0,004 mm, on the side faces, they are not deeper than 0,01 mm, and on other surfaces, they are not deeper than 0,06 mm. 4.3.2 Indentations
38、 and depressions Indentations and depressions are permissible provided that the values given in Table 1 for number and spacing of defects are met, no burrs are produced exceeding the permissible values given in 4.4.1.1, and they do not exceed the values for size and depth given in Table 2. Rings of
39、a plated/coated/nitrided type shall not have indentations or depressions on the periphery. NOTE Indentations arising from hardness measurements on the side faces are acceptable provided that they do not exceed the limits given in Tables 2 and 11. 4.3.3 Cracks No cracks are permissible. See also 4.5.
40、4 for chromium-plated peripheral surfaces and 4.5.6 for nitrided surfaces. Table 2 Permissible size of indentations and depressions Dimensions in millimetres Nominal diameter d 1 Defect size max. Depth max. On peripheral surface On side face 30 d 1 100 0,3 0,6 10 % of corresponding max. defect size
41、100 d 1 200 0,5 1 4.4 Edges 4.4.1 E dge c onfigur ation All edges of the piston ring shall be sharp; ideally, they should be free from burrs and from ragged edges, whether arising from crumbling of material or from deburring. Such conditions are almost impossible to achieve regularly in volume produ
42、ction and hence both burrs and removal of edge material is permitted up to the maximum sizes given in 4.4.1.1 and 4.4.1.2. ISO 2013 All rights reserved 3BS ISO 6621-5:2013ISO 6621-5:2013(E) 4.4.1.1 Burrs Burrs are permitted up to the maximum values given in Table 3. The orientation and direction of
43、burrs shall relate to the functional surfaces of the piston ring; any burr present should point in the direction of sliding motion of the ring and not normal to the direction of sliding. Any burrs remaining on the edges of rings should be firmly attached, forming an integral part of the edge. Table
44、3 Permissible size of burrs for all sizes of ring Dimensions in millimetres Burrs on edges adjacent to: Maximum size of burr Cast iron and steel single and two-piece rings Expander/segment oil control rings Expander Plated segment Nitrided seg- ment Peripheral surface 0,006 0,01 0,004 0,004 Side fac
45、es 0,006 0,01 0,02 0,01 Butt ends (gap surface) 0,04 0,1 0,1 0,04 The outside groove face (oil rings) 0,2 The inside surface and the ends of the slots (oil rings) 0,5 0,5 0,1 0,1 All other surfaces 0,1 0,1 0,1 0,1 4.4.1.2 Edge material removal To eliminate protruding burrs in any direction, it is pe
46、rmissible to remove material from the edges to the values given in Table 4. Table 4 Edge material removal in deburr operations Dimensions in millimetres Location of edge Removal of material max. On peripheral edges 0,08 On peripheral edges of the gap a 0,15 On inside edges of the gap 0,5 in circumfe
47、rential direction 0,25 in radial direction On other edges 0,25 aDoes not apply to rings which have specified gap edge chamfers. 4.4.2 Chipping and similar defects on peripheral edges, peripheral edges of the gap, outside gap corners, and on peripheral chamfers Chipping and similar defects are permit
48、ted at these points provided that they are free of loosely adhering particles, no burrs are produced exceeding the values permitted in 4.4.1.1, they do not exceed half the width of any witness land on, for example, taper-faced rings, and4 ISO 2013 All rights reservedBS ISO 6621-5:2013ISO 6621-5:2013
49、(E) they do not exceed the values given in the following tables: Table 5 for plain rings; Table 6 for chromium-plated or nitrided rings; Table 7 for spray-coated rings; Table 8 for chamfers on all rings. Typical defects are illustrated in Figures 1 to 6. K 1 , K 2 , and K 3are always the dimensions of the defect measured along the edge cut by the defect. F 1 , F 2 , and F 3are always the dimensions of the defect measured fro
