SAE J 1051-1993 Force-Deflection Measurements of Cushioned Components of Seats for Off-Road Work Machines.pdf

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4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J1051_201308 SURFACE VEHICLE STANDARD J1051 AUG2013 Issued 1974-01 Reaffirmed 201

5、3-08 Superseding J1051 APR2008 Force-Deflection Measurements of Cushioned Components of Seats for Off-Road Work Machines RATIONALE J1051 has been reaffirmed to comply with the SAE five year review policy. 1. ScopeThis SAE Standard provides a method to obtain consistent force-deflection data of finis

6、hed (orunfinished, when specified) cushioned components of seats for off-road work machines as listed in SAEJ1116. This data may be helpful in maintaining seat comfort characteristics and quality control. There is nointent to establish any acceptance criteria.2. References2.1 Applicable Publications

7、The following publication forms a part of this standard to the extent specifiedherein. The latest issue of SAE publications shall apply.2.1.1 SAE PUBLICATIONSAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.SAE J1116Categories of Off-Road Work MachinesSAE TSB 002Preparation of S

8、AE Technical ReportsSAE REPORTFormat Guidelines for the Electronic Capture of SAE Documents, June 19923. Technical Requirements3.1 Test Apparatus3.1.1 A 200 mm diameter, rigid, flat, or curved indentor (Figure 1 and Figure 2) or a 50 mm diameter, rigid, flatindentor (Figure 1). The indentor force sh

9、all be applied through a rigid joint or a swivel joint capable ofaccommodating the angle of the top surface of the test specimen.3.1.2 A platform capable of positioning the top surface of the test specimen parallel to and centered with the rigidjoint indentor and not to restrict the breathing or nor

10、mal deformation of the specimen tested (Figure 3). Theindentor with the swivel joint may be preferred for tapered or irregular shaped cushions or for a fixed platform(Figure 4).3.1.3 An apparatus capable of applying forces and measuring the deflection of the indentor into the specimen.FIGURE 1FLAT I

11、NDENTORFIGURE 2CURVED INDENTORFIGURE 3ADJUSTABLE PLATFORMSAE J1051 Reaffirmed AUG2013 Page 2 of 4_FIGURE 4SWIVEL JOINT INDENTOR3.2 Procedure3.2.1 TEST SPECIMENThe test specimen shall consist of a seat cushion, back cushion, or other components in anunused condition (with packaging or protective bag

12、removed).3.2.2 TEST CONDITIONSThe specimen shall be conditioned, undeflected, and undistorted at 22 C 2.8 C andrelative humidity of 50% 2% for at least 12 h before being tested. The tests shall be performed 96 h ormore after the manufacture of the raw materials used in the test specimen (foam, elast

13、ic components otherthan metal, etc.). In case of a question, refer to the applicable SAE or ASTM specification (if available) forthe particular material.3.2.3 PERCENT DEFLECTIONPercent Deflections are determined using the cushion material and cover without thesupporting structure (base).3.2.4 TEST M

14、ETHOD3.2.4.1 Mount SpecimenMount the specimen with the top surface parallel to and centered with the indentor,unless otherwise specified by mutual agreement of the manufacturer and the customers. The 200 mmdiameter curved or flat indentor shall be used on seat and back cushions unless otherwise spec

15、ified. Alight muslin of a quality comparable to a grade described as a weave of 48 threads per inch and density of190 g/m2is allowed to prevent marking of the component. In the case of components with unusual shapesor contours, location for placement, and the size of the indentor is to be agreed upo

16、n by the manufacturerand customer and shall allow a minimum of 80% of the indentor area to be in contact when the initialzeroing force of 3.2.3.3 is applied. (Example: Smaller diameter or curved indentor for curved backrestsee Figure 2.)3.2.4.2 PreflexPreflex the test specimen three times by compres

17、sing and releasing the force at a rate of 100mm/min. The specimen shall be compressed as follows:a. Seat Cushion: 1335 Nb. Back Cushion: 665 Nc. Other Components: Compress to 20% of original thicknessAllow 10 min 5 min for the specimen to stabilize after preflexing before continuing the test.3.2.4.3

18、 Zero the Deflection ScaleApply a force of 45 N to the 200 mm diameter indentor or 10 N to the 50 mmdiameter indentor and set the deflection scale to zero.SAE J1051 Reaffirmed AUG2013 Page 3 of 4_3.2.4.4 Force-Deflection ApplicationFor the 200 mm indentor, apply an incremental force (no greater than

19、220 N) slowly to minimize shock. Allow 1 min for the specimen to stabilize, then measure the deflection.Continue this incremental procedure without removing the preceding force until the maximum force of 1335N for the seat cushion and 665 N for the back cushion is reached. For the 50 mm indentor or

20、thin cushions,incremental deflection versus force may be more desirable. When incremental deflection is used, thespecimen shall be compressed to not less than 20% of its original thickness. When the maximum force is45 N or less the indentor diameter should be increased if possible.3.2.4.5 Force-Defl

21、ection RemovalAfter reaching maximum force, reduce the force slowly (minimize shock) in220 N maximum increments, allowing 1 min for the test specimen to stabilize before measuring deflectionat each increment.3.2.4.6 Return TimeDeflect the cushion to 25% 2.5% of undeflected condition and hold for 1 m

22、in. Release theload in 0.5 s or less and record the time taken to return to the undeflected condition.3.3 Data Required3.3.1 Description of the test specimen (Manufacturers name, number, etc.).3.3.2 Diameter and curvature of the indentor.3.3.3 Deviations on special test conditions.3.3.4 Location of

23、the indentor on the test specimen.3.3.5 Record all force-deflection data taken during the application and removal of the force on the test specimen.3.3.6 Plot the force on the Y-axis versus deflection on the x-axis.PREPARED BY THE SAE HUMAN FACTORS TECHNICALCOMMITTEE SC4OPERATOR SEATING AND RIDESAE J1051 Reaffirmed AUG2013 Page 4 of 4_