1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 2009 SAE InternationalAll rights reserved. No part of this publication may be
3、reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying,recording, or otherwise, without the prior written permission of SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-
4、776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSURFACEVEHICLERECOMMENDEDPRACTICEJ2370REAF.MAR2009Issued 2001-05Reaffirmed 2009-03Superseding J2370 DEC2003Geometric Dimensions and Tolerancing for Curved HoseForewordThe design engineer assigning tolerances for size, length and
5、geometry must consider function, matingrelationships, virtual condition, datums, and economy. Owing to the construction of rubber hoses (syntheticelastomeric material) and being a “non-rigid” product that can be deformed by shipping conditions, measurementforces, and in many cases its own weight, ca
6、re must be taken in applying GD no tolerances for true position outerboundary (see Section 3) will be included with this document. The true position tolerance for the outer boundaryshall be determined by customer and supplier and should be based on feasibility analysis conducted prior to finalreleas
7、e of design record.1. ScopeTo provide the curved hose industry and their customers with a recommended practice for applyingGD or if datum targets are designated,positioned against datum target features simulators. Other than locating on the specified datum features andother datum target features (su
8、pport points) as designated on the drawing, the hose will be considered to bein its “free-state.”6.2 Method 26.2.1 The part may also be described by establishing a datum reference frame at one end of the hose andproviding additional support or restraint as necessary (see Figures 2 and 3).6.2.2 PRIMA
9、RY DATUMThe primary datum feature is the internal diameter (I.D.) of one of the hose ends. Thedatum is the axis of the internal diameter over a prescribed length. The axis is theoretically the intersectionof two mutually perpendicular planes, which are the origin of measurement in two (of three) dir
10、ections.6.2.3 SECONDARY DATUMThe secondary datum feature is the end surface of the hose. The datum is a planewhich is perpendicular to the primary datum axis (and planes) and is the origin of measurement in the thirddirection.6.2.4 TERTIARY DATUMThe tertiary datum feature may be an alignment mark or
11、 datum target which can be usedwhen orientation is essential. Since the three datum planes and directions of measurement have alreadybeen established, the tertiary datum merely orients the part in space relative to them.6.2.5 Since a hose is flexible, supplemental support or restraint may be require
12、d beyond those identified in thedatum reference frame. These features may be covered in a note on the drawing and must be used forinspection as indicated. By placing the datum and additional support features in a holding fixture in relativelocation and orientation, according to the car coordinate in
13、formation, the hose can be inspected as installed(see Figures 2 and 3).7. Drawing Notes and Symbols7.1 True Position SymbolThe hose contour is specified by using a True Position Symbol with a cylindricaltolerance zone at Maximum Material Condition (MMC) for the feature tolerance. Datums, if applicab
14、le arespecified as Regardless of Feature Size (RFS).7.2 Support PointsAll vehicle hose support points, or restrictions (brackets etc.) are to be identified and locatedwith appropriate geometric tolerancing dimensions and symbols.7.3 BoundaryThe outside contour of the hose is controlled by a true pos
15、ition outer boundary tolerance zone.The tolerance zone follows the basic centerline of the hose, and its zone is equal to the hose outsidediameters MMC size plus the positional tolerance. The outside surface of the hose must reside within thisboundary. To invoke this concept, the term BOUNDARY is pl
16、aced beneath the feature control frame (seeFigures 1 to 3).SAE J2370 Reaffirmed MAR2009-5-FIGURE 1DRAWING WITH MULTIPLE DATUM FEATURESSAE J2370 Reaffirmed MAR2009-6-FIGURE 2DRAWING WITH DATUM TARGETSSAE J2370 Reaffirmed MAR2009-7-FIGURE 3DRAWING WITH DATUM FEATURES ANDDATUM PLANES OFFSET FROM FEATUR
17、ESSAE J2370 Reaffirmed MAR2009-8-FIGURE 4RIGHT HAND RULE AND REFERENCE COORDINATE TABLESAE J2370 Reaffirmed MAR2009-9-FIGURE 5DATUM REFERENCE FRAMESAE J2370 Reaffirmed MAR2009-10-8. Notes8.1 Marginal IndiciaThe change bar (l) located in the left margin is for the convenience of the user in locatinga
18、reas where revisions have been made to the previous issue of the report. An (R) symbol to the left of thedocument title indicates a complete revision of the report.PREPARED BY THE SAE NON-HYDRAULIC HOSE COMMITTEESAE J2370 Reaffirmed MAR2009RationaleFigure 4 was a duplicate of Figure 2 instructions a
19、nd therefore deleted. Wherever Figure 4 was inthe text it was replaced with Figure 2. The boundary boxes on Figures 2 and 3 were standardized.Figures 5 and 6 were re-numbered Figures 4 and 5 and the text updated to match the new numberingscheme.Relationship of SAE Standard to ISO StandardNot applica
20、ble.ApplicationTo provide the curved hose industry and their customers with a recommended practice forapplying GD&T procedures to curved hoses and to provide generic curved hose drawings that representthe application of GD&T to typical curved hose parts. Dimensioning and Tolerancing will be inaccordance with ASME Y14.5M.Reference SectionSAE J20Coolant System HosesASME Y14.5M 1994Dimensioning and TolerancingDeveloped by the SAE Non-Hydraulic Hose Committee
