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.QUESTIONS REGARDING THIS DOCUMENT: (724) 772-8512 FAX: (724) 776-0243TO PLACE A DOCUMENT
3、 ORDER; (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 1998 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001RECOMMENDEDPRACTICEAn American National StandardJ839REI.SEP1998Issued 19
4、62-11Reissued 1998-09Superseding J839 JUN97 CancPassenger Car Side Door Latch Systems1. ScopeThis SAE Recommended Practice establishes minimum performance requirements and testprocedures for evaluating and testing passenger car side door latch systems. It is limited to tests that can beconducted on
5、uniform test fixtures and equipment in commercially available laboratory test facilities.The test procedures and minimum performance requirements outlined in this document are based on currentlyavailable engineering data. It is intended that all portions of the document will be periodically reviewed
6、 andrevised, as additional knowledge regarding vehicle latch performance under impact conditions is developed.2. ReferencesThere are no referenced publications specified herein.3. Definitions3.1 LatchA mechanical device employed to position the door in a closed position relative to the vehicle bodyw
7、ith provisions for controlled release (or operation).3.1.1 Basic latch components (nomenclature) are:a. PlateThe main body or frame for supporting working components, appendages, and transmitting ordistributing loads to the door structure.b. Rotor (Or Bolt)The rotating or sliding member of the latch
8、 which engages and restrains the latch tothe striker.c. RatchetA member of the latch connected to the rotor to provide an abutment or abutments which,when properly indexed, become engaged with a related pawl to inhibit motion of the rotor in onedirection.d. PawlA member of the latch that can be caus
9、ed to engage the abutments of the ratchet to inhibitrelative motion between the two parts except in one direction.3.2 StrikerA mechanical device with which the latch engages on the opposing member of the body.3.3 Fully Latched PositionThe attitude that exists between the latch and striker when the d
10、oor is securelypositioned in the fully closed position.COPYRIGHT Society of Automotive Engineers, Inc.Licensed by Information Handling ServicesSAE J839 Reissued SEP1998-2-3.4 Secondary Latched PositionThe attitude that exists between the latch and striker when the latch holds thedoor in a position l
11、ess than fully closed.NOTEThe secondary latched position may be included in the side door latch, as an added mechanicalfeature to reduce the possibility of the door opening freely, in the event the door is not closed to the fullylatched position. It should be recognized that doors are intended to be
12、 in the fully latched positionwhenever the vehicle is in motion.4. Basic Requirements4.1 Longitudinal LoadAn automotive door latch and striker assembly, when tested as described under testprocedures, must be able to withstand an ultimate longitudinal load of 11 000 N when in the fully latchedpositio
13、n (see 5.1) and 4450 N when in the secondary latched position (see 5.2).4.2 Transverse LoadAn automotive door latch and striker assembly, when tested as described under testprocedures, must be able to withstand an ultimate transverse load of 8900 N when in the fully latched position(see 5.3) and 445
14、0 N when in the secondary latched position (see 5.4).4.3 Inertia LoadAn automotive door latch, when contained in the door latch system (including the door latch,striker assembly, outside handle, key cylinder, and any connecting mechanisms) and, in the fully latchedposition, when evaluated by calcula
15、tion, must remain in the fully latched position when subjected to an inertiaload of 30 g in any direction. (See Section 6.)NOTE Due to the interdependency of the components, it is important that the door latch be analyzed withinthe confines of the total system and these results considered the basis
16、of acceptance.5. Static Tests5.1 Longitudinal LoadFully Latched Position5.1.1 PURPOSETo determine the ability of the vehicle latch and striker to withstand a test load perpendicular tothe face of the latch.5.1.2 EQUIPMENTa. Tensile testing machine.b. Static test fixture (see Figure 1).5.1.3 OPERATIO
17、Na. Attach the test fixture to the mounting provisions of the latch and striker. Align the direction ofengagement parallel to the linkage of the fixture. Mount fixture with latch and striker in fully latchedposition in the test machine so as to apply a load perpendicular to the face of the latch.b.
18、Locate weights to apply an 890 N load tending to separate the latch and striker in the direction of thedoor opening.c. Apply the test load at a rate not to exceed 5 mm/min until failure. Record maximum load.5.2 Longitudinal LoadSecondary Latched Position5.2.1 PURPOSETo determine the ability of the v
19、ehicle latch and striker in the secondary position to withstand atest load perpendicular to the face of the latch.COPYRIGHT Society of Automotive Engineers, Inc.Licensed by Information Handling ServicesSAE J839 Reissued SEP1998-3-5.2.2 EQUIPMENTa. Tensile testing machine.b. Static test fixture (see
20、Figure 1).FIGURE 1DOOR LATCHSTATIC LOAD TEST FIXTURE (LONGITUDINAL LOAD)5.2.3 OPERATIONa. Attach the test fixture to the mounting provisions of the latch and striker. Align the direction ofengagement parallel to the linkage of the fixture. Mount fixture with latch and striker in secondarylatched pos
21、ition in the test machine so as to apply a load perpendicular to the face of the latch.b. Locate weights to apply an 890 N load tending to separate the latch and striker in the direction of thedoor opening.c. Apply the test load at a rate not to exceed 5 mm/min until failure. Record maximum load.d.
22、The test plate to which the door latch is mounted will have a striker cutout configuration similar to theenvironment in which the door latch will be mounted on normal vehicle doors.5.3 Transverse LoadFully Latched Position5.3.1 PURPOSETo determine the ability of the vehicle latch and striker to with
23、stand the test load in the direction ofdoor opening.COPYRIGHT Society of Automotive Engineers, Inc.Licensed by Information Handling ServicesSAE J839 Reissued SEP1998-4-5.3.2 EQUIPMENTa. Tensile testing machine.b. Static test fixture (see Figure 2).FIGURE 2DOOR LATCHSTATIC LOAD FIXTURE (LATERAL LOAD)
24、5.3.3 OPERATIONa. Adapt the test fixture to the mounting provisions of the latch and striker. Mount fixture with the latchand striker in fully latched position in the test machine so as to apply a load in the direction of dooropening.b. Apply the test load at a rate not to exceed 5 mm/min until fail
25、ure. Record the maximum load.5.4 Transverse LoadSecondary Latched Position5.4.1 PURPOSETo determine the ability of the vehicle latch and striker in the secondary position to withstand thetest load in the direction of door opening.5.4.2 EQUIPMENTa. Tensile testing machine. b. Static test fixture (see
26、 Figure 2).COPYRIGHT Society of Automotive Engineers, Inc.Licensed by Information Handling ServicesSAE J839 Reissued SEP1998-5-5.4.3 OPERATIONa. Adapt the test fixture to the mounting provisions of the latch and striker. Mount fixture with the latchand striker in secondary latched position in the te
27、st machine so as to apply a load in the direction ofdoor opening.b. Apply the test load at a rate not to exceed 5 mm/min until failure. Record the maximum load.6. Inertial Analysis6.1 PurposeTo determine the ability of the vehicle latch system to resist inertia loading by means of amathematical anal
28、ysis of the component parts in their true car relationship.NOTEDue to the complexity of physical testing for inertial characteristics, it is judged to be more practicaland more accurate to base evaluations on mathematical analysis. The procedure described in thissection provides a means for analytic
29、ally determining the ability of a door latch system to withstandinertia loading. Spring forces are the average of the minimum spring output in the installed positionand the minimum spring output in the release position. Friction effects and work to be done are notconsidered in the calculations. Grav
30、itational pull on components may also be omitted if it tends torestrict unlatching. These omissions from the calculations are permissible because they provideadditional factors of safety.6.2 Calculation ConsiderationEach component or subassembly can be calculated for its minimum inertia loadresistan
31、ce in a particular direction. Their combined resistance to the unlatching operation must assure that thedoor latch system (when properly assembled in the vehicle door) will remain latched when subjected to aninertia load of 30 g in any direction. Figure 3 is an example of the components and combinat
32、ions ofcomponents to be considered.COPYRIGHT Society of Automotive Engineers, Inc.Licensed by Information Handling ServicesSAE J839 Reissued SEP1998-6-FIGURE 3INERTIA LOADINGSAMPLE CALCULATIONPREPARED BY THE SAE LATCH AND HINGE SUBCOMMITTEECOPYRIGHT Society of Automotive Engineers, Inc.Licensed by I
33、nformation Handling ServicesSAE J839 Reissued SEP1998RationaleSAE J839 was canceled in June 1997. It has been reissued.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationThis SAE Recommended Practice establishes minimum performance requirements and testprocedures for evaluation an
34、d testing passenger car side door latch systems. It is limited to tests thatcan be conducted on uniform test fixtures and equipment in commercially available laboratory testfacilities.The test procedures and minimum performance requirements outlined in this document are based oncurrently available e
35、ngineering data. It is intended that all portions of the document will be periodicallyreviewed and revised, as additional knowledge regarding vehicle latch performance under impactconditions is developed.Reference SectionThere are no referenced publications specified herein.Developed by the SAE Latch and Hinge SubcommitteeCOPYRIGHT Society of Automotive Engineers, Inc.Licensed by Information Handling Services
