QCT221-1997标准（英文版）

QC/T 221-1997PrefaceThis Standard is formulated on the basis of the plan for formulation and revision of standards made in 1995.This Standard is formulated by reference to the relevant American Standard SFI and Japanese Standard JASO.This Standard is put forward by the Ministry of Machine Building Industry of the Peoples Republic of China.This Standard is placed under the administration of the National Automotive Standardization Technical Committee.This Standard is drafted by Guangdong Nanhai Zhongnan Alloy Hub Co., Ltd. with the assistance of Lizhong Wheel Manufacture Co., Ltd.Main Draftsperson: Lei MingjunAutomobile Industrial Standard of the Peoples Republic of ChinaQC/T 221-1997Requirements and Test Methods for Performance of Light Alloy Automobile Wheel 1. ScopeThis Standard sets forth requirements and test methods for dynamic bending fatigue performance and dynamic radial fatigue performance of light alloy automobile wheel.This Standard is applicable to any automobile wheel which is totally or partially made of light alloys.2. Test Item2.1 Dynamic Bending Fatigue Test2.2 Dynamic Radial Fatigue Test 3. Test SpecimenThe wheels used in bending fatigue test and radial fatigue test shall be new finished wheels which have not been tested or used, and only one time of test is allowed to be carried out on every wheel. 4. Dynamic Bending Fatigue Test4.1 Test EquipmentThe test stand shall be equipped with a rotating device so that the wheel may rotate under an unchanged bending torque or the wheel stands still and bears a rotating & bending torque (See Figure 1 hereof).4.2 Test ProcedureArm of ForceTest LoadingMounting SurfaceFigure 1 Schematic Diagram of Apparatus for Dynamic Bending Fatigue Test4.2.1 PreparationOn the basis of the actual situation that the wheel is mounted on the vehicle, fix the wheel to the supporting surface of the test apparatus with the torque which is 115% of the minimum torque specified; be sure not to apply any lubricant to any nut.After adjusting the location of the wheel, make the wheel rim clamped by the clamping apparatus, and remove all unnecessary articles, dust or foreign matters from the mating surface between the wheel and the test apparatus.In the course of the test, the bolts and nuts on the wheel may be tightened up again.The loading system shall maintain the load specified, of which the error may not exceed 2.5%.In case any bolt is broken in the course of the test, it is allowed to continue the test after the broken bolt is replaced.4.2.2 Bending TorqueThe bending torque is determined on the basis of the following equation:M = (R+d)FSWhere:M Bending torque, Nm; Friction coefficient between tire and road, which is set at 0.7;R Dead-load diameter, namely the maximum tire dead load diameter specified by the wheel manufacturer or the vehicle manufacturer for the wheel, m;d Offset distance of wheel, (offset distance for inside wheel is positive, offset distance for outside wheel is negative), determined by the wheel manufacturer, m;F Maximum rated load of wheel, determined by the wheel manufacturer or the vehicle manufacturer, N;S Intensified test coefficient (See Table 1 hereof)4.3 Test Requirement on Dynamic Bending FatigueTable 1 Test Requirement for Dynamic Bending FatigueCode of Nominal Diameter of Wheel RimIntensified Test CoefficientSCycles12, 13, 14, 15, 16, 171.610000016, 17 (optional)1.352500004.4Basis of Invalidationa) Fatigue crack is found on any portion of the wheel through dye penetrant inspection or other acceptable inspection such as zyglo inspection; b) The wheel fails to bear the load before the cycles required have been finished.In case the displacement of load point exceeds 20% of the original fully-loaded displacement before the required cycles have been finished, it shall be concluded that the wheel fails the test.5. Dynamic Radial Fatigue Test5.1 Test ApparatusThe test apparatus is a device which is equipped with a rotating drum. The surface of such rotating drum is smooth and is wider than the contact area of the wheel tested. The connection of the test apparatus shall match with the wheel rim in nature. When the wheel is rotating, the test apparatus shall be able to apply a constant radial load to the wheel, and the wheel-loading direction shall be vertical to the surface of the rotating drum and be in line with the center of wheel and the center of the rotating drum and be parallel to the axial line of rotating drum and the axial line of wheel. It is recommended that the minimum diameter of the rotating drum shall be 1700 mm (See Figure 2). 5.2 Test Procedure5.2.1 PreparationThe wheel used in the test shall be the wheel which has the maximum load bearing capacity as specified by the wheel manufacturer or the vehicle manufacturer. In case a wheel without inner tire is tested, no inner tire may be used. The recommended air pressure for tire is 44835kPa (cold state). The tire pressure may rise in the course of the test, however, it is unnecessary to carry out adjustment.Wheel Nut and BoltLight Alloy WheelRadial LoadTireRotating DrumFigure 2 Schematic Diagrams of Apparatus for Dynamic Radial Fatigue TestMake sure that the connecting pieces used in the test match with the wheel, fix the wheel with the bolts and nuts specified, tighten up the nuts with the torque which is 115% of the lower limit of the tightening torque specified for the nuts. In the course of the test, inspect and adjust the torque of the nuts regularly, be sure not to apply any lubricant to the nuts.Make sure that the loading system can maintain the load as required and the error is less than 2.5%.In case the tire tested is damaged in the course of the test, it is allowed to continue the test after the damaged tire is replaced.5.2.2 Radial LoadThe radial load is determined on the basis of the following equation:Fr = FKWhere:Fr Radial load, N;F Maximum rated load of wheel, determined by the wheel manufacturer or th