1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW16708 Overall Seat Hardness and Seat Hardness Distribution Test Procedure Copyright 2012 General Motors Company All Rights Reserved June 2012 Originating Department: North American Engineering Standards Page 1 of 20 1 Scope Note: Nothing in this sta
2、ndard supercedes applicable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. This document provides test methods for evaluating performance characteristics of motor vehicle seating related to occu
3、pant support, penetration, and comfort. It provides a means of comparing and assessing comfort-related performance of complete prototype or competitive benchmark vehicle seat systems. 1.2 Foreword. The tools and procedures for determining seat coordinate positions used in this document are based on
4、the SAE J826 H-Point Machine (Manikin). 1.3 Applicability. These test procedures apply to complete seat systems (production seats or prototypes built at the intended manufacturing quality). Testing must be performed on complete seat backs and complete seat cushions. Tests performed on subsystems or
5、individual components will not be considered valid. For convenience and simplicity, many terms associated with H-Point devices use human body parts in their name. However, they should not be construed as measures that indicate interaction with any or all occupants concerning accommodation, human cap
6、abilities, or comfort. H-Point devices do not represent the size or posture of any category of occupant (see SAE J2896). 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. SAE J826 SAE J2896 2.2 GM Standards/Specifi
7、cations. GMW16710 GMW16719 GMW16712 2.3 Additional References. None 3 Resources 3.1 Facilities. Tests must be performed in a climate controlled area capable of maintaining a constant temperature of 23 C 2 C and a relative humidity of 50% 5%. 3.2 Equipment. 3.2.1 Load/Deflection Measuring System. A s
8、ystem capable of applying forces up to 1500 N at a constant rate and measuring the resulting indenter position is required. Optionally, a system that is capable of performing tests on the seat, while the seat is mounted in the vehicle, may be used, provided the vehicle suspension effects are removed
9、. 3.2.2 Seat Fixture. Fixture capable of simulating the position of the seat within the vehicle and capable of mounting the seat in positions required for testing of seat cushion and seat back. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo
10、 reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16708 Copyright 2012 General Motors Company All Rights Reserved June 2012 Page 2 of 20 3.2.3 Indenters. For overall seat cushion measurements, the SAE J826 buttock form, as seen in Figure 1, shal
11、l be used with a fixed joint. If overall seat back measurements are desired, the SAE J826 back form shall be used with a fixed joint. Figure 1: SAE J826 Buttock and Back Pans for Overall Cushion/Seat Back Measurements Note: For the Hardness Distribution Test, an indenter, as shown in Figure 2, is to
12、 be used. Figure 2: Indenter for Hardness Distribution Test 3.3 Test Vehicle/Test Piece. A complete seat created at the intended level of manufacturing quality shall be used. 3.4 Test Time. Calendar time: 1.5 days Test hours: 8 hours Coordination hours: 4 hours 3.5 Test Required Information. Torso a
13、ngle, thigh angle, and Seating Reference Point (SgRP). For General Motors vehicles, the seat should be set into the audit position per GMW16710 and the design SgRP used. For Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or net
14、working permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16708 Copyright 2012 General Motors Company All Rights Reserved June 2012 Page 3 of 20 competitive/Non-GM vehicles, the seat should be placed and the H-Point found using GMW16719. SgRP/ H-Point will be referred to a
15、s the reference point in this procedure. 3.6 Personnel/Skills. Test requires an engineer or technician capable of mounting the seat and running test machinery. 4 Procedure 4.1 Preparation. The specimen should be conditioned, undeflected, and undistorted at 23 C 2 C and relative humidity of 50% 5% fo
16、r at least 4 h before being tested. The tests shall be performed 72 h or more after the manufacturing of the raw materials used in the test specimen (foam, elastic components other than metal, etc.) 4.2 Conditions. 4.2.1 Environmental Conditions. Test shall be run at 23 C 2 C and relative humidity o
17、f 50% 5%. 4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 4.3 Instructions. 4.3.1 Seat Setup. The seats shall be placed into the same position used for f
18、inding H-Point. For General Motors vehicles, GMW16710 shall be used. For competitive/Non-GM vehicles, GMW16719 shall be used. Any nonstandard adjustable features should be set to the specified positions. If no setting is specified, features should be set to full off or retracted position (e.g., lumb
19、ar support or thigh extender). Note: When setting the tilt on the seat, it should be set in the neutral position (middle position); if no tilt position is specified. Measurements shall be referenced to the H-Point, thigh angle, and the torso angle. For General Motors vehicles, the nominal values sha
20、ll be provided by GM. Loading direction is to be normal to thigh angle (cushion) and torso angle (back) as shown in Figures 3 thru 5. If a competitive seat is to be measured, use H-Point procedure from GMW16719 to set the seat in the correct position. For seat force vs. deflection testing of competi
21、tive seats, the load direction should be normal to the measured thigh angle and torso angle as seen in Figures 3 thru 5. Figure 3: Load Directions Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without l
22、icense from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16708 Copyright 2012 General Motors Company All Rights Reserved June 2012 Page 4 of 20 Figure 4: Seat Cushion Fixed, Indentation Normal to Thigh Line Figure 5: Seat Back Fixed, Indentation Normal to Torso Line Notice the Head Restraint Bars a
23、re Supported Seats should be attached to a rigid fixture capable of securing the test sample in proper position and orientation under test conditions. When performing tests on the seat back, the seat back must be supported or blocked so as to keep the frame from bending due to unintended flex or adj
24、uster movement. One way that this may be accomplished is to place blocks underneath the head restraint bars. Place a piece of muslin cotton cloth over the seat area to be checked during all tests. The muslin cloth should be of sufficient size to prevent the machine from contacting the seat. The musl
25、in should be a plain cotton fabric having a thread count and weight typical of a durable, mid-grade, general-purpose muslin that is available from most fabric stores. The muslin should have enough slack so that the cloth does not provide resistance to the indentation. If the muslin cloth is pulled t
26、oo tight over the surface, the resistance of the cloth will affect the loading/unloading curve. 4.3.2 Overall Cushion Measurement. During the overall cushion measurement, the H-Point of the buttock shape is to be placed 50 mm forward of the reference point of the seat. This is done as it is not poss
27、ible on many seats to match the H-Point of the buttock form and the reference point of the seat without the buttock shape coming into contact with the seat back. This contact with the seat back would skew the results of the loading test. The placement of the loading point is outlined in Figure 6. To
28、 meet this requirement, the loading point will differ for each buttock form, as the mounting point may be different from one buttock form to the next. See Appendix A3 for details in measuring this X-Offset. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot
29、 for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16708 Copyright 2012 General Motors Company All Rights Reserved June 2012 Page 5 of 20 Figure 6: Overall Cushion Measurement Loading Point Location The test is to be performed is out
30、lined as follows. Prior to the test, the force on the machine should be zeroed. No preload should be used. A conditioning cycle should be run prior to each test run. The conditioning cycle should reach a maximum load of 1100 N at a rate of 200 mm/minute and then removed with instantaneous changeover
31、 at a rate of 200 mm/minute. Upon termination of the conditioning cycle, there should be a 5 s dwell time prior to the test run. The test cycles maximum loading force should be 1100 N at a rate of 200 mm/minute. Changeover time from loading to unloading should be instantaneous. Record the force-posi
32、tion data taken during the application and removal of the force on the test specimen. Allow the specimen to rest for 60 s before running subsequent trials. Typically, three total trials are collected. Data is to be collected from both the conditioning cycles and test cycles. 4.3.3 Overall Back Measu
33、rement. When performing the overall back measurement, the location of the loading point is to be set so that the H-Point location of the back form matches the location of the reference point of the seat. As the location of the mounting fixture used on each individual back form may differ, it will be
34、 necessary to measure the Z-Offset between the H-Point of the back form and the location of the mounting/loading point as seen in Figure 7. For details regarding the measurement of the Z-Offset value see Appendix A4. Figure 7: Overall Back Measurement Loading Point Location Copyright General Motors
35、Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16708 Copyright 2012 General Motors Company All Rights Reserved June 2012 Page 6 of 20 The test is to be performed
36、 as specified by SAE J2896. This is outlined as follows. Prior to the test, the force on the machine should be zeroed. No preload shall be used. A conditioning cycle should be run prior to each test run. The conditioning cycle shall reach a maximum load of 550 N at a rate of 200 mm/minute and then r
37、emoved with instantaneous changeover at a rate of 200 mm/minute. Upon termination of the conditioning cycle, there should be a 5 s dwell time prior to the test run. The test cycles maximum loading force should be 550 N at a rate of 200 mm/minute. Changeover time from loading to unloading should be i
38、nstantaneous. Record the force-position data taken during the application and removal of the force on the test specimen. Allow the specimen to rest for 60 s before running subsequent trials. Typically, three total trials are collected. Data is to be collected from both the conditioning cycles and te
39、st cycles. 4.3.4 Hardness Profile Test. The support provided by a seat system is determined by the shape of the seat surface, the support structure (frame), and the loading characteristics of these materials. This test measures the contour or hardness profile of motor vehicle seats. Measurements are
40、 to be performed with lumbar full off and lumbar full on. Set maximum loading force to: a. Seat Cushion: 200 N (44.2 lbf) b. Seat Back: 100 N (22.1 lbf) Set indenter speed to 200 mm/minute with an instantaneous changeover time. At each cross section, spacing between consecutive points should be no g
41、reater than 25 mm, as seen in Figure 8. Measurements should be taken at points along the cross sections locations presented in Tables 1 and 2. An example grid of indentation points on a seat cushion is seen below in Figure 8. This is the minimum amount of points that should be tested with a default
42、spacing of 25 mm between points. If greater resolution between points is needed, indentations may be performed at a lesser spacing at the discretion and need of the operator. Note: Only one column 110 mm to the right or left of the centerline needs to be performed. In Figure 8, the column of points
43、is shown on the right. Table 1: Seat Cushion Sections Section Definition Figure Lateral Cross Section 0 mm forward of the reference point. 9 Lateral Cross Section 125 mm forward of the reference point. 9 Lateral Cross Section 250 mm forward of the reference point. 9 Centerline Cross Section 0 mm lat
44、eral of the reference point. (Plane parallel to the cushion and torso (back) line through SgRP) 10 Centerline Cross Section 110 mm on either side of the reference point. (Note that only the positive OR negative side of the centerline is necessary) 10 Table 2: Seat Back Sections Lateral Cross Section
45、 35 mm above the reference point. 9 Lateral Cross Section 175 mm above the reference point. 9 Lateral Cross Section 350 mm above the reference point. 9 Centerline Cross Section 0 mm lateral of the reference point. (Plane parallel to the cushion and torso (back) line through SgRP) 10 Centerline Cross
46、 Section 110 mm on either side of the reference point. (Note that only the positive OR negative side of centerline is necessary) 10 Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS
47、-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16708 Copyright 2012 General Motors Company All Rights Reserved June 2012 Page 7 of 20 Figure 8: Seat Cushion and Seat Back with Grid of Indentation Points In Figures 9 and 10, a detailed diagram of the spacing of columns and rows of indentation points with
48、 respect to H-Point is given. Figure 9: Recommended Lateral Cross Sections Referenced from H-Point Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STA
49、NDARDS GMW16708 Copyright 2012 General Motors Company All Rights Reserved June 2012 Page 8 of 20 Figure 10: Recommended Centerline Sections Referenced from H-Point Position the indenter at least 5 mm above initial contact over the local point. Record the force-position data taken during the application and removal of force on the test specimen. Data sh
