GB/T 20069-2006 Road vehicle — Fifth wheel couplings strength tests
1 Scope
This standard specifies the strength requirements and test conditions to be met by 50 and 90 fifth wheel couplings.
This standard is applicable to 50 and 90 fifth wheel couplings.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this standard. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest editions of the normative document referred to applies.
GB/T 13880 Road vehicles - Semi trailer fifth wheel mounting (GB/T 13880-1992, idt ISO 3842:1984)
GB/T 3730.2 Road vehicle - Masses - Vocabulary and codes (GB/T 3730.2-1996, idt ISO 1176:1990)
3 Requirements
3.1 Static lifting test requirements
3.1.1 Up to a lifting force of FA1, as specified in 5.2.1.1, there shall be no major permanent bending of the coupling plate over more than 0.2% of its width.
3.1.2 In the case of fifth wheel couplings and comparable couplings for the same kingpin diameter, there shall be no separation of the kingpin from the coupling with a lifting force of FA2 (as specified in 5.2.1.3) or FA3 (as specified in 5.2.1.3).
3.2 Dynamic test requirements
After completing the dynamic tests as specified in 5.3, the fifth wheel couplings shall not cause permanent deformation, breaks or cracks.
3.3 Additional requirements
The additional test items and strength requirements for fifth wheels intended for forced semi-trailer axle steering (through a steering wedge) are specified in Annex C.
4 Determination of longitudinal forces (D-value) between the towing vehicle and the semi-trailer
The D-value is a comparative value determined by calculation for the longitudinal forces occurring between the towing vehicle and the semi-trailer. D, expressed in kilonewtons (kN), shall be calculated from the equation:
Contents
Foreword II
1 Scope
2 Normative references
3 Requirements
4 Determination of longitudinal forces (D-value) between the towing vehicle and the semi-trailer
5 Test conditions
Annex A (Informative) Comparison between this standard and ISO 8717:2000 in clause/subclause numbers
Annex B (Informative) Technical deviations between this standard and ISO 8717:2000 and their justifications
Annex C (Normative) Additional requirements for fifth wheels intended for forced semi-trailer axle steering
