1、BRITISH STANDARD BS EN ISO 5456-2:1999 Technical drawings Projection methods Part 2: Orthographic representations The European Standard EN ISO 5456-2:1999 has the status of a British Standard ICS 01.100.01 BS EN ISO 5456-2:1999 This British Standard, having been prepared under the direction of the E
2、ngineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 October 1999 BSI 15 September 2002 ISBN 0 580 35160 2 National foreword This British Standard is the English language version of EN ISO 5456-2:1999. It is identical with ISO 5456-2:1
3、996. The UK participation in its preparation was entrusted to Technical Committee TDE/4, Engineering drawing, metrology, precision measurement and all related documentation, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secre
4、tary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement international or European publications r
5、eferred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of
6、 a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the
7、interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO
8、title page, pages ii to iv, pages 1 to 10, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 5456-2
9、 July 1999 ICS 01.100.10 English version Technical drawings Projection methods Part 2: Orthographic representations (ISO 5456-2:1996) Dessins techniques Mthodes des projection Partie 2: Reprsentations orthographiques (ISO 5456-2:1996) Technische Zeichnungen Projektionsmethoden Teil 2: Orthogonale Da
10、rstellungen (ISO 5456-2:1996) This European Standard was approved by CEN on 27 May 1999. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lis
11、ts and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the respo
12、nsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Net
13、herlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1999 CEN All rights of exploitation in any form and by any mean
14、s reserved worldwide for CEN national Members. Ref. No. EN ISO 5456-2:1999 EEN ISO 5456-2:1999 BSI 15 September 2002 Foreword The text of the International Standard from Technical Committee ISO/TC 10, Technical drawings, product definition and related documentation, of the International Organization
15、 for Standardization (ISO) has been taken over as a European Standard CEN/CS. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2000, and conflicting national standards shall be withdrawn at
16、 the latest by January 2000. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembo
17、urg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of the International Standard ISO 5456-2:1996 has been approved by CEN as a European Standard without any modification. NOTE Normative references to International Standards are listed i
18、n Annex ZA (normative).EN ISO 5456-2:1999 ii BSI 15 September 2002 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
19、 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, in liaison with ISO, also take part in the work. ISO collaborates closely with
20、 the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. 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 th
21、e member bodies casting a vote. International Standard ISO 5456-2 was prepared by Technical Committee ISO/TC 10, Technical drawings, product definition and related documentation, Subcommittee SC 1, Basic conventions. ISO 5456 consists of the following parts, under the general title Technical drawing
22、s Projection methods: Part 1: Synopsis Part 2: Orthographic representations Part 3: Axonometric representations Part 4: Central projection Annex A forms an integral part of this part of ISO 5456. Descriptors: graphic methods, drawings, technical drawings, graphic projections.EN ISO 5456-2:1999 BSI 1
23、5 September 2002 iii Introduction Orthographic representation in its various forms is the most widely used method of representing technical objects in all fields of technical drawing (mechanical, electrical, construction, etc.), and is thus considered to be the accepted technical language.iv blankEN
24、 ISO 5456-2:1999 BSI 15 September 2002 1 1 Scope This part of ISO 5456 specifies basic rules for the application of orthographic representation to all types of technical drawings in all technical fields, according to the general rules specified in ISO 128, ISO 129, ISO 3098-1, ISO 3461-2 and ISO 545
25、6-1. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 5456. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this
26、part of ISO 5456 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 128:1982, Technical drawings General principles of presentation. ISO 129:198
27、5, Technical drawings Dimensioning General principles, definitions, methods of execution and special indications. ISO 3098-1:1974, Technical drawings Lettering Part 1: Currently used characters. ISO 3461-2:1987, General principles for the creation of graphical symbols Part 2: Graphical symbols for u
28、se in technical product documentation. ISO 5456-1:1996, Technical drawings Projection methods Part 1: Synopsis. ISO 10209-1:1992, Technical product documentation Vocabulary Part 1: Terms relating to technical drawings: general and types of drawings. ISO 10209-2:1993, Technical product documentation
29、Vocabulary Part 2: Terms relating to projection methods. 3 Definitions For the purposes of this part of ISO 5456, the definitions given in ISO 5456-1, ISO 10209-1 and ISO 10209-2 apply.EN ISO 5456-2:1999 2 BSI 15 September 2002 4 General principles 4.1 General Orthographic representation is obtained
30、 by means of parallel orthogonal projections and results in flat, two-dimensional views systematically positioned relative to each other. To show an object completely, the six views in the directions a, b, c, d, e and f may be necessary, in order of priority (see Figure 1 and Table 1). 4.2 Designati
31、on of views See Table 1. Table 1 The most informative view of the object to be represented is normally chosen as the principal view (front view). This is view A according to the direction of viewing a (see Figure 1 and Table 1), generally showing the object in the functioning or manufacturing or mou
32、nting position. The position of other views relative to the principal view in the drawing depends on the projection method chosen (first angle, third angle, reference arrows). In practice, not all six views (A to F) are needed. When views (cuts or sections) other than the principal view are necessar
33、y, these shall be selected in order to: limit the number of views, cuts and sections to the minimum necessary and sufficient to fully represent the object without ambiguity; avoid unnecessary repetition of detail. Figure 1 Direction of observation Designation of view View in direction View from at h
34、 e f r o n t A ba b o v e B (E) 1) ct h e l e f t C dt h e r i g h t D e below E ft h e r e a r F 1) See 5.4.EN ISO 5456-2:1999 BSI 15 September 2002 3 5 Methods of representation 5.1 First angle projection The first angle projection method is an orthographic representation in which the object to be
35、 represented (see Figure 1) appears between the observer and the coordinate planes on which the object is orthogonally projected (seeFigure 2). The positions of the various views relative to the principal (front) view A are determined by rotating their projection planes around lines coinciding with
36、or parallel to the coordinate axes on the coordinate plane (drawing surface) on which the front view A is projected (see Figure 2). Therefore, in the drawing, with reference to the principal view A, the other views are arranged as follows (see Figure 3): View B: the view from above is placed underne
37、ath; View E: the view from below is placed above; View C: the view from left is placed on the right; View D: the view from the right is placed on the left; View F: the view from the rear is placed on the right or on the left, as convenient. The identifying graphical symbol of this method is shown in
38、 Figure 4. Figure 2EN ISO 5456-2:1999 4 BSI 15 September 2002 5.2 Third angle projection The third angle projection method is an orthographic representation in which the object to be represented (see Figure 1), as seen by the observer, appears behind the coordinate planes on which the object is orth
39、ogonally projected (see Figure 5). On each projection plane, the object is represented as if seen orthogonally from infinite distance with transparent projection planes. The positions of the various views relative to the principal (front) view A are determined by rotating their projection planes aro
40、und lines coinciding with or parallel to the coordinate axes on the coordinate plane (drawing surface) on which the front view A is projected (see Figure 5). Therefore, in the drawing, with reference to the principal view A, the other views are arranged as follows (seeFigure 6): View B: the view fro
41、m above is placed above; View E: the view from below is placed underneath; View C: the view from the left is placed on the left; View D: the view from the right is placed on the right; View F: the view from the rear may be placed on the left or on the right, as convenient. The identifying graphical
42、symbol of this method is shown in Figure 7. Figure 3 Figure 4EN ISO 5456-2:1999 BSI 15 September 2002 5 Figure 5 Figure 6EN ISO 5456-2:1999 6 BSI 15 September 2002 5.3 Reference arrows layout In those cases where it is advantageous to position the views not according to the strict pattern of the fir
43、st or the third angle projection method, the use of the reference arrows method permits the various views to be freely positioned. With the exception of the principal view, each view shall be identified by a letter in accordance with Figure 1. A lower-case letter indicates in the principal view the
44、direction of observation of the other views, which are identified by the corresponding capital letter placed immediately above the view and on the left. The identified views may be located irrespective of the principal view (see Figure 8). Whatever the direction of observation, the capital letters (
45、see ISO 3098-1) identifying the views shall always be positioned to be read from the normal direction of viewing of the drawing. No graphical symbol for the indication of this method is needed on the drawing. 5.4 Mirrored orthographic representation Mirrored orthographic representations 1)is an orth
46、ographic representation in which the object to be represented (see Figure 1) is a reproduction of the image in a mirror (face up) which is positioned parallel to the horizontal planes of this object (see Figure 9). The view resulting from a mirrored orthographic representation may be indicated by us
47、ing the capital letter for the designation of views (i.e. “E”, see 4.2). Figure 7 Figure 8 1) This method is preferably used in construction drawings.EN ISO 5456-2:1999 BSI 15 September 2002 7 The identifying graphical symbol of this method is shown in Figure 10. Figure 9 Figure 10EN ISO 5456-2:1999
48、 8 BSI 15 September 2002 Annex A (normative) Proportions and dimensions of graphical symbols A.1 General requirements In order to harmonize the sizes of the graphical symbols specified in this part of ISO 5456 with those of the other inscriptions on the drawing (dimensions, tolerances, etc.), the ru
49、les given in ISO 3461-2 shall be applied. A.2 Proportions The graphical symbols shall be drawn in accordance with Figure A.1, Figure A.2 and Figure A.3. For practical reasons the centrelines may be omitted. Figure A.1 Figure A.2EN ISO 5456-2:1999 BSI 15 September 2002 9 A.3 Dimensions The range of sizes to be used for the graphical symbols and additional indications shall be as specified in Table A.1.
