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 entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, 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 2007 SAE International All rights reserved. No part of this publication m
3、ay be 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)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org J1691 REV. FEB2007 SURFACE VEHICLE RECOMMENDED PRACTICE Issued 1997-04 Revised 2007-02 Superseding J1691 APR1997 Plastic Motor Vehicle Safety GlazingTolerances and Fabrication Details RATIONALE Modifications to the R
5、ecommended Practice are made to clarify thermal expansion, modulus of elasticity, and definition of marking parameter. 1. SCOPE This SAE Recommended Practice is intended to cover plastic safety glazing for use in motor vehicles and motor vehicle equipment. Nominal specifications for thickness, flatn
6、ess, curvature, size, and fabrication details are presented principally for the guidance of body engineers and designers. For additional information on plastic safety glazing materials for use in motor vehicles and motor vehicle equipment, please see SAE J674. 2. REFERENCES 2.1 Applicable Publicatio
7、n The following publication forms a part of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. 2.1.1 SAE Publication Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (i
8、nside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J674 Safety Glazing MaterialsMotor Vehicles 2.2 Related Publications The following publications are provided for information purposes only and are not a required part of this document. 2.2.1 SAE Publication Available from SAE Inte
9、rnational, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J673 Automotive Safety Glazing SAE J1691 Revised FEB2007 - 2 - 2.2.2 FMVSS Publication Available from the Superintendent of Documents, U.S. Governme
10、nt Printing Office, Mail Stop: SSOP, Washington, DC 20402-9320. FMVSS 205 Glazing Materials 3. SIZES There are no standard sizes applicable to plastic safety glazing for use in motor vehicles and motor vehicle equipment. The feasibility of proposed plastic safety glazing sizes developed by the motor
11、 vehicle/motor vehicle equipment manufacturer must be determined by conference with the plastic glazing fabricator. The various types of plastic safety glazing (flat or curved) are as follows: injection molded, extruded (formed), and cell cast. 4. TYPICAL COMMERCIAL TOLERANCE INFORMATION 4.1 Thickne
12、ss Commercially available flat or curved plastic safety glazing has thickness tolerance as follows in Table 1: TABLE 1THICKNESSES(1)Type of Plastic Safety Glazing Typical Nominal Thickness Injection Molded and Extruded 4.00, 5.00, and 6.00 (5% of total thickness) mm 0.157, 0.197, and 0.236 (5% of to
13、tal thickness) inches Cell Cast 4.00, 5.00, and 6.00 (+10% / -20% of total thickness) mm 0.157, 0.197, and 0.236 (+10% / -20% of total thickness) in 1. NOTE - Other plastic safety glazing thicknesses may be acceptable for use in motor vehicles and motor vehicle equipment provided they meet the requi
14、rements of all applicable laws, regulations, codes, and practices in effect. 4.2 Flatness Flat safety plastic glazing of the types noted may have 0.8 mm (0.03 in) maximum total bow per 305 mm (12 in length), and each part may have a maximum overall bow, in millimeters, of 0.0026 times the length of
15、the part. 4.3 Curvature Dimensional tolerances on the physical dimensions of curved injection molded, extruded (formed), or cell cast plastic automotive safety glazing parts shall be specified as follows, with reference to numeric design data or to a master die model derived from numeric data suppli
16、ed by the automotive manufacturer. a. SizeMaximum size (plus zero) with specified minimum size. Allowances must be made for the thermal expansion and contraction of the material based upon design and installation. In addition, material stresses need to be accounted for in order to meet acceptable di
17、mensional tolerance limits. These material stresses are both a function of the thermal deformation vector (i.e., CTE) and the materials elastic modulus. The Coefficient of Thermal Expansion for several plastic glazing materials (e.g., polycarbonate and acrylic) is shown in Table 2 along with the Mod
18、ulus of Elasticity for each material. SAE J1691 Revised FEB2007 - 3 - TABLE 2COEFFICIENT OF THERMAL EXPANSION AND MODULUS OF ELASTICITY FOR TYPICAL PLASTIC GLAZING MATERIALS Type of Safety Glazing Material Coefficient of Thermal Expansion Modulus of Elasticity Polycarbonate 6.8 x 105(m/m/C), 3.8 x 1
19、05(in/in/F) 2.3 GPa Acrylic 7.4 x 105(m/m/C), 4.1 x 105(in/in/F) 2.5 GPa b. ThicknessNominal thickness, with acceptable commercial ranges above and below nominal. c. ContourPeripheral or edge contour may be specified in terms of maximum departure from the peripheral face of the desired surface. Cent
20、ral area surface contour may be specified in terms of permissible deviations of curvature from the designed contour. For example, this contour may be measured from the vertical centerline chord of the plastic, taken at the point of maximum designed depth of curvature. NOTEManufacturing tolerances on
21、 size and contour will vary with design and should be established by conference. Designs for complex curved parts should recognize and accommodate necessary tolerances on size and shape. 5. FABRICATION DETAILS 5.1 Curved plastic safety glazing parts are generally checked for size and curvature on a
22、male checking gauge made to receive the desired surface of the plastic. The male checking gauge should be accurate, rigid, and permanent. Size is checked using maximum and minimum lines, stops, or notches on the gauge. 5.2 Peripheral or edge contour is usually checked by inserting a thickness feeler
23、 gauge (where possible) between the face of the checking ledge and the plastic. The width of the face of the checking ledge can vary with design and should be established by conference. 5.3 The central area of the checking gauge is undercut, with a spring pin or other means of checking the surface c
24、ontour at the specified area. 5.4 Size tolerances for curved injection molded, extruded, or cast plastic glazing are affected by pattern and degree of curvature and should be checked by the manufacturer. 5.5 Mark Off (Extruded or Cell Cast) Mark-off for thermoformed cast or extruded sheet may extend
25、 to 13 mm (0.5 in) maximum from the edge of the plastic depending on the size and complexity of the curved part, unless otherwise specified. 5.6 Drilled Holes (Extruded or Cell Cast) The dimensions and tolerances for the size and location of drilled holes will vary with design and plastic thickness
26、and should be established by conference. 5.7 Edges The edges should be finished with regard to the design and engineering of the motor vehicle, location of the glazing and in conjunction with regulatory standards as well as the plastic glazing manufacturers recommended practices. 5.8 Injection-molde
27、d edges do not require finishing unless specified by the automotive manufacturer or regulatory requirements. SAE J1691 Revised FEB2007 - 4 - 5.9 Markings Markings are to be in accordance with current government regulations. Location of these markings must be visible for identification after installa
28、tion. Any other special identifying marks required must be specified and located on the drawing and must be apart from the plastic manufacturers distinctive trademark or other markings required by law, ordinance, or regulation. The marking should include the recycling symbol for the particular plast
29、ic being used.1For example, the recycling symbol for a polycarbonate glazing material is represented by: 7PC FIGURE 1 6. NOTES 6.1 Marginal Indicia The change bar (l) located in the left margin is for the convenience of the user in locating areas where technical revisions have been made to the previous issue of the report. An (R) symbol to the left of the document title indicates a complete revision of the report. PREPARED BY THE SAE GLAZING MATERIALS STANDARDS COMMITTEE 1Resin Identification Coding System, The Society of the Plastics Industry (SPI), Inc., (1988).
