1、Test ProcedurePowertrain GME16200Spin Down Test1 IntroductionNote: Nothinginthisstandardsupersedesapplicablelaws and regulations.1.1 Purpose. Primary aim of this test is to measurein-car the drag torque of the drive train as a functionof speed in neutral gear.As a welcome side-effect also the inerti
2、a of the drivetrain is an intermediate result of the evaluation.1.2 Foreword. Transmission drag in neutral is asubset of the total vehicle road load.Thevehicle road loadis a prerequisite to run emissionand fuel consumption tests (e.g. for type approval)on a roller dynamometer.The road load is usuall
3、y determined by vehicle coastdowns on a proving ground. By means of spin downtest results the number of required vehicle coastdowns can be reduced to at least 1 drive train variantper carline. The remaining variants are calculated bysubtracting and adding the drag torque of differentdrive trains fro
4、m / to the road load of at least 1available vehicle road load.Beside of that the drag torque is an adequate indi-cation for the efficiency / losses of a transmission.But as a matter of course the spin down test is not asubstitute for a transmission efficiency map, since itis conducted without torque
5、 transfer (gear = neutral).1.3 Applicability. All vehicles with a mechanicaldrive train.2 ReferencesNote: Only the latest approved standards are appli-cable unless otherwise specified.2.1 External Standards/Specifications. None.2.2 GM Standards/Specifications.GMW150072.3 Additional References. Europ
6、ean patent num-ber of Spin Down Test: 08005637.7-12363 Resources3.1 Facilities. Set up example see Appendix A, Fig-ure 1.3.1.1 Garage box.3.1.2 Device to lift up the vehicle and fix it safely in aposition w/o ground contact of the wheels.3.1.3 Cooling blower in front of the vehicle.3.1.4 Exhaust-gas
7、 exhaustion.3.2 Equipment.3.2.1 Flywheels (replacement for the wheels).Use 2 flywheels with defined inertia for vehicles with1 driven axle, 4 for AWD.Recommendations:Use of 2 flywheel sets with different inertia (e.g. incase of AWD = 2 x 4 flywheels)Inertia of heavy flywheels | 2.5 kgm2Inertia of li
8、ght flywheels | 1.5 kgm23.2.2 Wheel-Speed Sensors.3.2.3 Transmission Oil Temperature Sensor.3.2.4 Data Acquisition. Capable to measured andrecord with 10 Hz:Each wheel speed.Test time.Transmission oil temperature.3.3 Test Vehicle / Test Piece. See paragraph 3.2.3.4 Test Time. 2 days, thereof test an
9、d coordinationtime | 8 h in each case.3.5 Test Required Information. See paragraph 4.3.6 Personnel / Skills. 2 workers, entitled to removeand reinstall brake calipers.4 Procedure4.1 Preparation.4.1.1 Vehicle Preparation.4.1.1.1 Install probe (e.g. thermocouple) for trans-mission oil temperature.4.1.
10、1.2 Set up the test vehicle into a stable horizontalposition in the garage box with free hanging wheelsclose above the ground. Copyright 2010 General Motors All Rights ReservedPublication Department: GME Specification CenterApril 2010 - Issue No. 1 Page 1 of 5PRD045 - VPRE ST 1 10/03 GME16200 GM EUR
11、OPE ENGINEERING STANDARDS4.1.1.3 Position an auxiliary blower in front of the carto support heat dissipation out of the engine compart-ment.4.1.1.4 Remove wheels of driven axle(s).4.1.1.5 Remove brake calipers and brake pads inorder to avoid residual brake drag during the test.4.1.1.6 Fasten flywhee
12、ls instead of the wheels. (Ifnecessary by means of an additional adapter collar).4.1.1.7 Fasten wheel-speed sensors.4.1.1.8 Accomplish the measuring set up by installa-tion of data acquisition system.4.1.1.9 Deactivate traction control system of the testvehicle in order to avoid active brake / throt
13、tle inter-vention during test run.4.1.2 Test Preparation. Warm up the transmissionby means of running engine until the desired trans-mission oil temperature for the test is reached. Applythe auxiliary blower to avoid heat storage.4.1.2.1 Warm up Procedure. Apply coast downsaccording to paragraph 4.3
14、 or another suitable pro-cedure (e.g. running with different speed / gears).4.1.2.2 Desired Transmission Oil Temperature.Average temperature observed during the road coastdown test with same vehicle, or another temperaturefor which the drag torque is intended to be measured.4.2 Conditions.4.2.1 Envi
15、ronmental Conditions. Recommenda-tion according vehicle road coast down procedure.Ambient temperature: (+20 15) CBarometric pressure: 100 kPa, if not possiblepreferably within (91 to 104) kPa.Relative humidity: 95 %.4.2.2 Test Conditions. Deviations from the require-ments of the test procedures shal
16、l have been agreedupon. Such requirements shall be specified on com-ponent drawings, test certificates, reports etc.4.3 Instructions. The test procedure is equivalentto GMW15007 Global Regulatory Coastdown Proce-dures (driving schedule for Europe).4.3.1 Data Acquisition Set Up. Set up the start ands
17、toptriggerfordatarecordingtotheconsideredspeedrange.In order to support the official road coast down thespin down test shall cover at least the same speedrange (120 to 20) km/h.Basedontheactualtirecircumferenceofthetestvehi-cle the equivalent drive shaft speed shall be deter-mined.Starttrigger: Driv
18、e shaft speed min-1 (rpm) equiv-alent 125 km/h or higher if desired.Stop trigger: Drive shaft speed min-1 (rpm) equiv-alent 15 km/h or lower if desired.4.3.2 Test Execution.1 Accelerate the drive train | 10 km/h above starttrigger.2 Declutch engine (manual transmission), shift intoneutral gear, rele
19、ase clutch pedal (manual trans-mission).3 Arm data acquisition before the decelerating driveshafts pass speed of start trigger.4 Test run is finished after stop trigger speed ispassed.5 Save recorded test run.4.3.3 Variation of Inertia Configuration. Run thespin down test at least in two different c
20、onfigurations:With preferably heavy flywheels and without fly-wheels.An additional flywheel configuration with e.g.lighter inertia is recommended in order to enablebetter verification of test results.4.3.4 General Recommendations. In order toassure steady test conditions repeat spin down runsuntil n
21、o spin down time drift of successive runs isobserved. Run the subsequently repeatable testsseveral times (e.g. 10) in order to apply the averageof these test data for the evaluation later on.If it is not possible to maintain desired transmissionoil temperature and simultaneously keeping the testruns
22、repeatabletrytochangeconfigurationofexternalblower, e.g.:Distance to the vehicle.Power of air flow.Open or close engine hood.4.3.5 Note. Normally the internal friction of the dif-ferential is experienced strong enough to ensure syn-chronized spin down speeds of all flywheels.Test data shall always b
23、e checked for speed devia-tions before evaluation. Copyright 2010 General Motors All Rights ReservedPage 2 of 5 Issue No. 1 - April 2010PRD045 - VPRE ST G 10/03 GM EUROPE ENGINEERING STANDARDS GME16200Occasionally occurring minor deviations | 1 % due tonatural resonances are acceptable. In this case
24、 theaveraged speed of all flywheels can be applied forfurther data evaluation.Significant speed deviations are supposed to becaused by a failure and do not comply with regularroad operation condition. In such a case the spindown test shall not be performed until the problem iseliminated.5 Data5.1 Ca
25、lculations. Calculation formula see AppendixA, Figure 3.Explanation formula symbols see paragraph 7.2.The official European vehicle road load (e.g. usedfor MVEG emission test) is defined within the speedrange(20to120)km/handexpressedbyapolynomialof 2nd order.In order to add or subtract the drag of d
26、rive train to /from the vehicle road load by simply add / subtractingthe coefficients of the polynomials the drag (12) shallbe approximated into a polynomial of 2nd order too.Hence, for this approximation apply the above speci-fied speed range.5.2 Interpretation of Results. See paragraph 5.1:Drag to
27、rque curve according (8) and / orPolynomial of 2nd order for drag force according to(12).Example Drag Torque see Appendix A, Figure 2.5.3 Test Documentation. The results shall be rep-resented in a test report with reference to this TestProcedure.6 SafetyThisstandard mayinvolvehazardousmaterials, ope
28、r-ations and equipment. This standard does not pro-pose toadress allthesafetyproblemsassociatedwithits use. It is the responsibility of the user of this stan-dard to establish appropriate safety and health prac-tices and determine the applicability of regulatory lim-itations prior to use.7 Notes7.1
29、Glossary. Not applicable.7.2 Acronyms, Abbreviations and Symbols.(min-1) drive shaft speed(km/h) vehicle speed(m) tire circumference(Nm) drag torque(N) drag force(kg m) inertia(rad/s) difference of angular speed(s) time increment(rad/s) rotational deceleration / t8 Coding SystemThisstandard shallber
30、eferenced inotherdocuments,drawings, etc. as follows:Example: “GME16200”9 Release and Revisions9.1 Release. This standard was first approved andreleased on 15/APR/2010.Content Owner: GMPT E9.2 Revisions.Rev. Date Description (Org.)1 APR 2010 First Release (GME Engineering) Copyright 2010 General Mot
31、ors All Rights ReservedApril 2010 - Issue No. 1 Page 3 of 5PRD045 - VPRE ST U 10/03 GME16200 GM EUROPE ENGINEERING STANDARDSAppendix AFigure 1: Test Set UpFigure 2: Example for Final Results Copyright 2010 General Motors All Rights ReservedPage 4 of 5 Issue No. 1 - April 2010PRD045 - VPRE ST G 10/03 GM EUROPE ENGINEERING STANDARDS GME16200Figure 3: Formula Copyright 2010 General Motors All Rights ReservedApril 2010 - Issue No. 1 Page 5 of 5PRD045 - VPRE ST U 10/03
