SAE J2370-2001 Geometric Dimensions and Tolerancing for Curved Hose.pdf

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SURFACE VEHICLE 400 Commonwealth Drive, Warrendale, PA 15096-0001 RECOMMENDED PRACTICE Submitted for recognition as an American National Standard J2370 ISSUED MAY2001 Issued2001-05 Geometric Dimensions and Tolerancing for Curved Hose ForewordThe design engineer assigning tolerances for size, length and geometry must consider function, mating relationships, virtual condition, datums, and economy. Owing to the construction of rubber hoses (synthetic elastomeric material) and being a “non-rigid” product that can be deformed by shipping conditions, measurement forces, and in many cases it's own weight, care must be taken in applying GD no tolerances for true position outer boundary (see Section 3) will be included with this document. The true position tolerance for the outer boundary shall be determined by customer and supplier and should be based on feasibility analysis conducted prior to final release of design record. 1.ScopeTo provide the curved hose industry and their customers with a recommended practice for applying GD or if datum targets are designated, positioned against datum target features simulators. Other than locating on the specified datum features and other datum target features (support points) as designated on the drawing, the hose will be considered to be in its “free-state.” 6.2Method 2 6.2.1The part may also be described by establishing a datum reference frame at one end of the hose and providing additional support or restraint as necessary (see Figures 3 and 4). 6.2.2PRIMARY DATUMThe primary datum feature is the internal diameter (I.D.) of one of the hose ends. The datum is the axis of the internal diameter over a prescribed length. The axis is theoretically the intersection of two mutually perpendicular planes, which are the origin of measurement in two (of three) directions. 6.2.3SECONDARY DATUMThe secondary datum feature is the end surface of the hose. The datum is a plane which is perpendicular to the primary datum axis (and planes) and is the origin of measurement in the third direction. 6.2.4TERTIARY DATUMThe tertiary datum feature may be an alignment mark or datum target which can be used when orientation is essential. Since the three datum planes and directions of measurement have already been established, the tertiary datum merely orients the part in space relative to them. 6.2.5Since a hose is flexible, supplemental support or restraint may be required beyond those identified in the datum reference frame. These features may be covered in a note on the drawing and must be used for inspection as indicated. By placing the datum and additional support features in a holding fixture in relative location and orientation, according to the car coordinate information, the hose can be inspected as installed (see Figures 3 and 4). 7.Drawing Notes and Symbols 7.1True Position SymbolThe hose contour is specified by using a True Position Symbol with a cylindrical tolerance zone at Maximum Material Condition (MMC) for the feature tolerance. Datums, if applicable are specified as Regardless of Feature Size (RFS). 7.2Support PointsAll vehicle hose support points, or restrictions (brackets etc.) are to be identified and located with appropriate geometric tolerancing dimensions and symbols. 7.3BoundaryThe outside contour of the hose is controlled by a true position outer boundary tolerance zone. The tolerance zone follows the basic centerline of the hose, and its zone is equal to the hose outside diameters MMC size plus the positional tolerance. The outside surface of the hose must reside within this boundary. To invoke this concept, the term BOUNDARY is placed beneath the feature control frame (see Figures 1 to 4). SAE J2370 Issued MAY2001 -5- FIGURE 1DRAWING WITH MULTIPLE DATUM FEATURES SAE J2370 Issued MAY2001 -6- FIGURE 2DRAWING WITH DATUM TARGETS SAE J2370 Issued MAY2001 -7- FIGURE 3DRAWING WITH MULTIPLE DATUM FEATURES AND DATUM PLANES OFFSET FROM FEATURES SAE J2370 Issued MAY2001 -8- FIGURE 4DRAWING WITH DATUM TARGETS AND DATUM PLANES OFFSET FROM FEATURES SAE J2370 Issued MAY2001 -9- FIGURE 5RIGHT HAND RULE AND REFERENCE COORDINATE TABLE SAE J2370 Issued MAY2001 -10- FIGURE 6DATUM REFERENCE FRAME PREPARED BY THE SAE COOLANT HOSE COMMITTEE SAE J2370 Issued MAY2001 RationaleNot applicable. Relationship of SAE Standard to ISO StandardNot applicable. ApplicationTo provide the curved hose industry and their customers with a recommended practice for applying GD&T procedures to curved hoses and to provide generic curved hose drawings that represent the application of GD&T to typical curved hose parts. Dimensioning and Tolerancing will be in accordance with ASME Y14.5M. Reference Section SAE J20Coolant System Hoses ASME Y14.5M 1994Dimensioning and Tolerancing Developed by the SAE Coolant Hose Committee