1、Test ProcedureLaboratory GME8724Underhood and Underbody Component TemperatureValidation Procedure for EuropeNote: This standard may be applied only for current projects incl. Global Epsilon (37#). It isSuperceded for all future projects and replaced by GMW14555.1 Introduction1.1 Purpose. To determin
2、e the operating tempera-tures of all vehicle components and fluids impactedby powertrain generated heat.1.2 Foreword. This procedure provides a uniformmethod to simulate vehicle operations under variousoperating modes at an outdoor test facility or in aclimatic wind tunnel. This procedure contains t
3、heschedules needed to validate the thermal require-ments found in the Vehicle Technical Specification(VTS). The temperature data obtained for each mea-surement point and sub-procedure is to be comparedto the specified temperature limits required of thatpoint and sub-procedure (dictated by the therma
4、lsection of the VTS).1.3 Applicability. For all passenger vehicles sold inEurope.1.4 Definitions.1.4.1 Ambient Temperature. The surrounding airtemperature measured at such a distance from thevehicle that the temperature reading is not signifi-cantly affected by the heat from the vehicle.1.4.2 Cycle.
5、 One complete execution of a drivingschedule as written.1.4.3 Drivers Aid. A device which assists a humandriver execute a prescribed velocity vs. time trace. Adrivers aid commonlyuses a displaywhich allows thedriver to “follow” the velocity Vs time profile.1.4.4 Idle. Engine operating with no operat
6、or inputto the throttle. An automatic transmission may be inDrive or Neutral as specified. A manual transmissionshould be in Neutral with the clutch pedal released.In both cases, the service brake should be releasedunless otherwise specified. The park brake may beapplied to prevent rolling.1.4.5 Ove
7、rrun. A condition caused by the downshift-ing of the transmission where the momentum of thevehicle causes the engine speed to increase. Fora manual transmission, shift to the lowest gear thatwill not cause engine speed to exceed its maximumdesign RPM at a specified vehicle speed.1.4.6 Control Module
8、 (PCM, VCM, TCM, etc.). Anonboard vehicle computer which controls fuel, sparktiming, EGR, transmission shift schedule, and vari-ous other functions according to vehicle parametersmonitored such as exhaust gas oxygen concentra-tion, manifold pressure, throttle position and vehiclespeed.1.4.7 Robotic
9、Driver. A throttle controller which hasthe additional ability of shifting gears (both manualand automatic) and applying the service brake.1.4.8 Soak (Ignition Off). Vehicle is stopped andignition turned off.1.4.9 Temperature Limits. A reference tempera-ture or temperatures used to determine suitabil
10、ity of acomponent (based on its material properties or otherfactors). A temperature limit is often specified rel-ative to a particular location on or near the compo-nent. Operational test results are compared to theirappropriate temperature limits. The VehicleTechnicalSpecification (VTS) defines thr
11、ee types of tempera-ture limits. The VTS specifies the type of temperaturelimit that is not to be exceeded for each portion of theprocedure. The three temperature limits are definedbelow.1.4.10 Continuous Temperature. The maximumtemperature a component will experience on a con-tinuous basis and main
12、tain its design functional life.1.4.11 ExcursionTemperature. Themaximumtem-perature a component will experience on an infre-quent basis and maintain its design functional life.1.4.12 Due Care Temperature (Extreme Event).The maximum temperature a component will expe-rience during specified conditions
13、 of abuse oroperation outside the owners manual. Componentsmay be damaged during event and the vehicle shallbe drivable after event. Copyright 2008 General Motors Corporation All Rights ReservedPublication Department: GME Specification CenterSeptember 2008 Page 1 of 12PRD045 - VPRE ST 1 10/03 GME872
14、4 GM EUROPE ENGINEERING STANDARDS1.4.13 ThrottleController. Adevice whichregulatesthe vehicles speed.1.4.14 Trailer Road Load. Force (or equation whichrepresents the force) that a representative trailerexerts on the vehicle when traveling on a levelsurface. The trailer road load is made up of rollin
15、gresistance and aerodynamic drag forces acting onthe trailer and is a function of the vehicle, trailerweight and velocity.1.4.15 HighSpeedatMaximumExhaustGasTem-perature. Fora flatroadandinthegearinwhichMax.Speed can be achieved, the speed which producesthe maximum exhaust gas temperature.1.4.16 Zer
16、o-point Measurement. Data scan takenbefore the powertrain or test started to document thepre-test state of each parameter.1.4.17 Road Load (RL). The force required to movea vehicle on level roads without acceleration.1.4.18 Grade Load (GL). The force required to oper-ate a vehicle on stretches of ro
17、ad along which theslope changes in the direction of travel.1.4.19 TrailerGradeLoad(TGL).The force requiredto operate a vehicle and specified trailer on stretchesof road along which the slope changes in the directionof travel.Note: Nothing in the specification supersedes appli-cable laws and regulati
18、ons.2 ReferencesNote: Only the latest approved standards are appli-cable unless otherwise specified.2.1 External Standards/Specifications. None.2.2 GM Group Standards/Specifications.GMI R-1A02-1GMI R-6Y-12.3 Additional References.Relevant Vehicle Technical Specification (VTS) -Thermal Section3 Resou
19、rcesThe test facilities and equipment shall be in goodworking order and shall have valid calibration labels.3.1 Facilities.3.1.1 Facilities Test. An outdoor test track shallbe equipped with a circular track with the appropriatesoak- wind break(see below). Thecircular track shallhave high speed testi
20、ng capability. To accommodatethe city traffic simulation, stop and go driving shall bepossible. The stop and go city traffic driving may beconducted on a circular or on a separate test tracklocated near the circular track.3.1.1.1 Wind Breaks. A 4 sided wind break with anopenroofisthepreferredwindbre
21、ak. Useofa3 sidedwind break with an open roof is permitted, a 2 sidedonly if it is possible to stop the test vehicle on thedownwind side.3.1.2 Facilities Climatic Wind Tunnel. Theclimatic tunnel shall be equipped with the followingcapabilities:Tunnel shall have a minimum wind speed and roadspeed cap
22、ability of 140 km/h.Ability to maintain the ambient as specified in theapplicable subsections (+25 C and +35 C).Ability to provide representative airflow through thevehicles heat exchangers, underhood, and aroundthe test vehicle.Ability to provide the appropriate loading of thevehicle (chassis dynam
23、ometer) as specified in theapplicable subsections.Recommendation: Tunnelwind speed controlshallhave the capability to follow vehicle velocity.Recommendation: Ability to provide the solarspecified in the applicable subsections is recom-mended but not required.3.1.2.1 Tunnel Use Recommendation. Unless
24、underbody temperature measurements and methodshave been correlated with road and/or test track data,underbody temperatures measured in a climatictunnel shall not be used for vehicle validation.3.2 Equipment.3.2.1 Sensing Equipment. Sensing equipment isnecessary to accurately acquire the temperature
25、ofa measurement point, pressures, currents, voltages,etc. This may include type K (chromel / alumel) ther-mocouple wire and probes, Skin Thermal Transducer(SST), infrared probes or imaging system, pressuretransducers of the appropriate range with signal con-ditioning, current shunts, and a device to
26、 obtain pow-ertrain control module parameters may also be used.3.2.2 Towing Dynamometer. A towing dynamome-ter shall be used on a circular track. The dynamome-ter shall be able to simulate the vehicle load associ-ated with uphill driving with and without a trailer.3.2.3 Data Processing and Reporting
27、. The largeamount of data involved makes it imperative that acomputersystem be used to receive the data from therecording equipment. Copyright 2008 General Motors Corporation All Rights ReservedPage 2 of 12 September 2008PRD045 - VPRE ST G 10/03GM EUROPE ENGINEERING STANDARDS GME87243.3 Test Vehicle
28、 / Test Piece.3.3.1 Vehicle Selection. Vehicle selection criteriashallcomprehendvariationsinthosecomponentsthatcan affecttemperatures (i.e. engine and transmissiontypes, finaldriveratio, tire size,coolingsystem capac-ity,airdams/spoilers,customer-selectedtransmissionshift schedule, etc.).3.3.2 Vehic
29、le Equipment. The test vehicle usedshall be fully configured with the recommendedequipment for towing the specified trailer weight forOperation on Grades (VTS-Requirement).3.3.3 Vehicle FrequentStop WarningLights. Ifthecity traffic test (paragraph 4.3.7.2) will be conductedon circular test track, th
30、e vehicle shall be equippedwith appropriate warning lights or signs to indicate thevehicle will be making frequent stops.3.3.4 Powertrain Assembly. The powertrainassembly shall be a verified production intent engine,transmission, final drive and calibration. The testvehicle engine, transmission, and
31、 axle shall have suf-ficient break-in prior to test. A 3200 km ( 2000 miles)minimum break-in is recommended.3.3.5 Cooling System. Verify that cooling systemrepresents intended design including, but not limitedto, front sheet metal, grille, fan(s), radiator, con-denser, engine and transmission oil co
32、olers (if any),working thermostat, fan logic, etc.3.4 Test Time. Following are estimates of the timeneeded to complete the various portions of theregional different parts.3.5 Test Required Information. The followinginformation is required to determine the dynamome-ter loads for the climatic wind tun
33、nel or towingdynamometer:Gross Vehicle Mass Ratings GVMR and GCMRInputsforloadcalculationperparagraph5.1.2(incl.vehicle speed for grade tests).Engine Maximum Power brake system fluid,booster, pipes, hoses; steering system fluid,hoses, boots; miscellaneous cables, hoses, link-ages, sensors; various c
34、ontainers, reservoirs, etc.near heat sources.Air Temperatures. Outside air entering and leav-ing various heat exchangers; underhood regions.Passenger Compartment (including Trunk):Surfaces which may come in contact with humanskin or may affect sensitive equipment (cameras,etc.) if stored there.Note:
35、 The locations where thermocouples areinstalled on any particular component shall be con-sistent with the locations specified for guidelinetemperatures. Copyright 2008 General Motors Corporation All Rights ReservedSeptember 2008 Page 11 of 12PRD045 - VPRE ST U 10/03GME8724 GM EUROPE ENGINEERING STAN
36、DARDSAppendix C - ThermocoupleInstallation GuidelinesThe proper location, construction and installationof the temperature sensing equipment is critical toobtaining accurate and representative results fromthe test. Misleading data and/or significant errors canresult from misplaced installation points
37、, improperlyformed thermocouple junctions, unsecured junctionmounting, damaged lead wires and other tempera-ture circuit problems. The information below is meantonly to call attention to some of the important factorswhich shall be considered in obtaining the test data.C.1 Measurement Location. In ca
38、ses where theprecise location at which the temperature shall besensed is not defined, tests may be needed to deter-mine the best measurement point. Infrared sensinginstruments (either discrete point or full field) or atemperature sensitive coating can be used to moreclearly define the appropriate in
39、stallation point. Inareas which are difficult to define, the thermocoupleshall be placed on a particular component at the pointwhich is nearest the heat source.Following facts / effects shall be taken into account:direct / reflected radiation, different surface orienta-tions, emissivities, heat cond
40、uctions, air flow, veloc-ity and direction of aur flow, thermal inertia of compo-nents, temperature limits etc.C.2 Junction Formation. The thermocouple effectis obtained by the junction of two dissimilar metals inthe temperature environment in question. The junc-tion is formed at the first electrica
41、l contact betweenthe two arms. The recommended method for mostapplications is inert-gas welding. The junction mayalso be formed by welding the wires ends in a dis-tance of (3.5) mm onto a metallic component. In anyevent,thejunctionshallprovidelowresistanceand bedurable. At some locations where tempe
42、ratures canchange quite rapidly, the mass of the junction shall bekept as small as possible to minimize response time.Where surface temperature shall be measured, thethermocoupleshall be inintimatecontact with the sur-face. Tominimizeradiantheaterrors, theemissivityoftheoutersurfaceofthejunctionshal
43、lapproximatethatofthe surroundingpart. Care shallbe takennot tosig-nificantly alter the insulation characteristics betweenthe junction or the component and the surrounding airby routing the thermocouple wires in an area of (moreor less) uniform temperature. The necessary lengthof this TC part - from
44、 the measuring spot - dependsupon thespecific localtemperaturegradients, the sur-rounding air temperature etc. (e.g. 40mmfora0.5 mm thermocouple).C.3 LeadWire. Careshallbetakentoassurethatthethermocouple lead wire is homogeneous and undam-aged. Significant errors can result from including sec-tions
45、which have been damaged or are not uniform inan unevenly heated environment. Cold workingofthewire during installation and use can result in notice-ableerrors. Thisis particularlytrue oftype-K (chromel- alumel) wire. Minimizing wire diameter will reducecold working effects. Stranded lead shall be co
46、nsid-ered where durability is a factor. Connectors in thecircuit can be of any convenient design if they are ina region of uniform temperature. Proper type designconnectors will be needed in regions of high thermalgradients. Copyright 2008 General Motors Corporation All Rights ReservedPage 12 of 12 September 2008PRD045 - VPRE ST G 10/03
