The accurate state fuel consumption of bench teat simulation road test-object quantity measuring method
Technical field
The accurate state fuel consumption of bench teat simulation road test-object quantity measuring method is that unloaded automobile is simulated the method that motor road test carries out the detection of standard state Fuel Consumption on chassis dynamometer, belongs to automotive performance detection method technical field.
Background technology
The measuring method of the existing commercial vehicle Fuel Consumption type designation of China is to adopt fully loaded automobile to detect hundred kilometric fuel consumptions in the speed of a motor vehicle point constant speed of regulation, calculates comprehensive hundred kilometric fuel consumptions by weight coefficient.Be that the road examination Fuel Consumption that detects with sample car specified states, gear and speed of a motor vehicle point constant speed stable state is as reference value with car.Background technology list of references: JT711-2008 " operating passenger car Fuel Consumption limit value and measuring method " and JT719-2008 " operation lorry Fuel Consumption limit value and measuring method ", two standards adopt the system-wide examination, when automobile production producer needs repetition test to the new model optimal design, perhaps when detecting, have following deficiency with ride examination carrying out standard state Fuel Consumption:
(1) each speed of a motor vehicle point road examination comes and goes test needs repeatedly, and many speed of a motor vehicle point constant speed are long detection time.(2) test place and environmental baseline are had relatively high expectations.(3) influenced by environmental parameter very big for road examination vehicle resistance.(4) bench teat is not considered the influence of environmental baseline to engine capacity and Fuel Consumption.
This method is suitable for automobile production producer and detects to the repetition test of new model Fuel Consumption research and development with at the Fuel Consumption with car, only need a road examination of sample car, consider of the influence of bench teat environmental baseline, make unloaded automobile on chassis dynamometer, simulate road examination carrying out standard state Fuel Consumption and detect engine capacity and Fuel Consumption.
Summary of the invention
Will accurately carry out the accurate state Fuel Consumption of unloaded automobile bench teat simulation road test-object detects, should guarantee engine output and rotating speed each speed of a motor vehicle point correspondent equal under standard state of the examination of same automobile bench teat and road, consider that bench teat engine output and Fuel Consumption are influenced by ambient condition.The concrete steps of this method are as follows:
1, the retarded velocity a that obtains each speed of a motor vehicle point is slided in unloaded or fully loaded automobile neutral road examination
i, m/s
2, calculate the SR F that each speed of a motor vehicle point is tried on zero load or fully loaded automobile neutral road
2, determine F
2Mode can have multiple: can each vehicle sample car by CC.5.1.1.2.7 money among the GB GB18352.3-2005 " light-duty vehicle pollutant emission limit and measuring method ", the mensuration resistance F that can Reference mass calculates as system inertia
MeasureAs F
2, also can add the mensuration resistance F that vehicle neutral chassis transmission revolving part equivalent inertia calculates as system inertia by Reference mass
MeasureAs F
2, also can be by GB GB18352.3-2005 CC.5.1.1.2.8 money, to measuring resistance F
MeasureF after the correction
Proofread and correctAs F
2
Can need not road examination, determine that by statistic law or computing method zero load or fully loaded automobile neutral road try the SR F of each speed of a motor vehicle point
2
2, unloaded automobile is after hanging up variator high speed gear on the chassis dynamometer, device for power absorption does not load, open the throttle and make the speed of a motor vehicle pine tar door that is above standard behind the 5km/h of the regulation highest detection speed of a motor vehicle hang neutral, adopt freedom and twice coastdown of loading, twice constant force to load wherein any method of coastdown, twice coastdown of increase and decrease inertia, or adopt coastdown one time, measure each speed of a motor vehicle point resistance F of neutral automobile, chassis dynamometer whole drive system
1
3, by the standard ambient condition of standard, the speed of a motor vehicle parameter of engine capacity is not subjected to the influence of ambient condition, and the driving force correction coefficient equals the capability correction coefficient, uses power correction coefficient a F
2Be modified to the engine driven power F under the current bench teat ambient condition
2D=F
2/ a, the automobile zero load is on chassis dynamometer, and the driver hangs up the transmission gear of regulation, stipulates identical speed of a motor vehicle point at each, the loading force F of device for power absorption on cylinder surface
3=F
2D-F
1, with F
3The constant force control loaded, the driver adjusts and stablizes accelerator pedal position, carries out the accurate state Fuel Consumption of bench teat simulation road test-object in regulation speed of a motor vehicle point constant speed stable state and detects.
4, after the engine that the new model automobile is carried out Fuel Consumption, wheel box, drive axle, wheel diameter optimal design, possible F
1Variation has taken place, and variation has also taken place in ambient condition, can set the F of original fully loaded road examination
2Constant, test F again
1, then F
2Be adapted to the engine driven power F under the bench teat current environment state
2D, obtain new F
3, device for power absorption on cylinder surface with new F
3Constant force loads, examination the carrying out standard state consumption trial of bench teat simulation road, and optimal design is until the requirement of new model Fuel Consumption conformance with standard limit value or reach good Fuel Consumption.
5, with the accurate state Fuel Consumption of car test mark, calculate or definite fully loaded or unloaded neutral road examination resistance F with this vehicle code requirement
2, use the power correction coefficient F
2Be modified to the engine driven power F under the current bench teat ambient condition
2D, measure at each speed of a motor vehicle point resistance F with car neutral, chassis dynamometer whole drive system
1, obtain corresponding F
3
The accurate state fuel consumption of bench teat simulation road test-object quantity measuring method, be applicable to when automobile production producer carries out new model Fuel Consumption optimal design need repetition test, perhaps when detecting with the car Fuel Consumption, unloaded automobile is simulated motor road test and is carried out the detection of standard state Fuel Consumption on chassis dynamometer, its technical characterstic is as follows:
Bench teat engine output and Fuel Consumption are influenced by ambient condition, standard ambient condition by standard, the driving force parameter of power is subjected to the influence of ambient condition, the driving force correction coefficient equals the capability correction coefficient, and the SR F of each speed of a motor vehicle point is tried on calculating or definite zero load or fully loaded automobile neutral road
2After, F
2Be modified to engine driven power F under the current bench teat ambient condition with power correction coefficient a
2D=F
2/ a measures each speed of a motor vehicle point resistance F of unloaded automobile neutral, chassis dynamometer whole drive system
1, the automobile zero load is on chassis dynamometer, and the driver hangs up the transmission gear of regulation, at the identical speed of a motor vehicle point of regulation, the loading force F of device for power absorption on cylinder surface
3=F
2D-F
1, with F
3The constant force control loaded, the driver adjusts and stablizes accelerator pedal position, carries out the accurate state Fuel Consumption of bench teat simulation road test-object in regulation speed of a motor vehicle point constant speed stable state and detects.Add F after vehicle neutral chassis transmission revolving part equivalent inertia calculates and proofreaies and correct as system inertia with Reference mass
Proofread and correctAs F
2, road examination load and bench teat load all have been adapted under the unified standard state, improved accuracy and consistance that the accurate state Fuel Consumption of bench teat simulation road test-object detects and estimates.
After automobile production producer is to the engine of this vehicle, variator, drive axle, wheel diameter optimal design, need not the road examination again of fully loaded automobile, set the F of fully loaded motor road test
2Constant, use the power correction coefficient F
2Be modified to the driving force F under the current bench teat ambient condition
2D, test F again
1Obtain new F
3, only need a road examination can carry out the bench teat repeatedly of this vehicle Fuel Consumption optimal design, when the vehicle total quality is big,, can approximate the equivalent inertia m that 1% kerb weight is estimated whole non-driving wheels by per two non-driving wheels for simplifying the operation
4
When using the accurate state Fuel Consumption of car test mark, the fully loaded or unloaded neutral road examination resistance F of calculating or definite this vehicle
2After, use the power correction coefficient F
2Be modified to the engine driven power F under the current bench teat ambient condition
2D, measure each speed of a motor vehicle point resistance F of unloaded neutral automobile, chassis dynamometer whole drive system
1, obtain corresponding F
3
Embodiment
With lorry new model optimal design and test with surveying with car test is being the embodiment that example illustrates this method: requirement in accordance with regulations, the mensuration resistance F that can Reference mass calculates as system inertia
MeasureAs F
2, also can add the mensuration resistance F that vehicle neutral chassis transmission revolving part equivalent inertia calculates as system inertia by Reference mass
MeasureAs F
2, also can be by to measuring resistance F
MeasureF after the correction
Proofread and correctAs F
2
Also can need not road examination, determine that by statistic law or computing method zero load or fully loaded automobile neutral road try the SR F of each speed of a motor vehicle point
2
1, lorry new model optimal design and test
Add F after vehicle neutral chassis transmission revolving part equivalent inertia calculates and proofreaies and correct as system inertia with Reference mass
Proofread and correctAs F
2, illustrate embodiment:
(1) the chassis dynamometer instructions indicates that its equivalent inertia is 896kg.From the tire handbook, search the moment of inertia L of tire, kg.m
2The equivalent inertia of metering tire is L/r
2, kg, r are tire radius m.
(2) driving wheel reaches dynamometer roller, device for power absorption does not load, after variator hangs up direct retaining, open the throttle and the speed of a motor vehicle is above standard after the regulation lorry detects the about 5km/h of max. speed 80km/h and be the 85km/h speed of a motor vehicle, the pine tar door is hung neutral, adopt freedom and twice coastdown of loading, twice constant force to load wherein any method of coastdown, twice coastdown of increase and decrease inertia, or adopt coastdown one time, record each speed of a motor vehicle point resistance F of neutral automobile, chassis dynamometer whole drive system
1And equivalent inertia m
2, obtain automobile neutral chassis power train revolving part equivalent inertia m
3=m
2-896.
(3), can adopt twice coastdown of bench teat to obtain the equivalent inertia m of the non-drive wheels of automobile as the moment of inertia L of unknown tire
4, vehicle front sails on the cylinder of chassis dynamometer, start counter drag motor to make front-wheel reach certain speed of a motor vehicle after, adopt twice coastdown of increase and decrease inertia, record the equivalent inertia m of vehicle front (non-driving wheel)
4
(4) lorry is fully loaded to total quality, hangs up fifth wheel instrument on the road of regulation examination runway, the speed of a motor vehicle is surpassed hang the examination of neutral road behind the 85km/h to slide, and records the retarded velocity a of each speed of a motor vehicle point
i, calculate the road test system resistance F of each speed of a motor vehicle point
Measure=(m
3+ m
4+ m) * a
i, m is the fully loaded lorry total quality of weighing.
(5) calculate the F of each speed of a motor vehicle point
Measure, measure the environmental parameter of road examination, road examination load correction coefficient in accordance with regulations is the F of each speed of a motor vehicle point
MeasureProofread and correct and be F
Proofread and correctThe back is as F
2, connect fuel consumption meter after, with power correction coefficient a F
2Be modified to the driving force F under the current bench teat ambient condition
2D=F
2/ a is at each regulation speed of a motor vehicle point, the loading force F of device for power absorption on cylinder surface
3=F
2D-F
1Constant force loads, and the driver hangs up the transmission gear of regulation, and adjustment and stable throttle carry out Fuel Consumption in regulation speed of a motor vehicle point constant speed stable state and detect.Can be F
2Load in the regulation road examination that detects with the car Fuel Consumption as this vehicle.
(6) comprehensive hundred kilometers fuel consumption that detect when this vehicle do not reach the standard limited value requirement, as behind optimal design engine, variator, the drive axle etc. again, need not the road examination again, establish F
2Constant, F
2Be modified to the driving force F under the current bench teat ambient condition
2D, test F again
1Obtain new F
3, the standard state consumption trial is carried out in unloaded then vehicle bench teat simulation fully loaded vehicle road examination, continues to optimize and tests, and requires or advanced Fuel Consumption until the limit value that reaches standard.
2, at the embodiment of surveying Fuel Consumption with car test
(1) road of known this vehicle examination F
2Or calculate F in accordance with regulations
2After, use power correction coefficient a F
2Be modified to the driving force F under the current bench teat ambient condition
2DUnloaded automobile is after hanging up variator high speed gear on the chassis dynamometer, device for power absorption does not load, open the throttle make the speed of a motor vehicle be above standard regulation detect the 5km/h of the speed of a motor vehicle after the pine tar door hang neutral, adopt freedom and twice coastdown of loading, twice constant force to load wherein any method of coastdown, twice coastdown of increase and decrease inertia, or adopt coastdown one time, measure each speed of a motor vehicle point resistance F of neutral automobile, chassis dynamometer whole drive system
1, use power correction coefficient a F
2Be modified to the driving force F under the current bench teat ambient condition
2D=F
2/ a is at each regulation speed of a motor vehicle point, the loading force F of device for power absorption on cylinder surface
3=F
2D-F
1Constant force loads, and the driver hangs up the transmission gear of regulation, and adjustment and stable throttle carry out Fuel Consumption in regulation speed of a motor vehicle point constant speed stable state and detect.
This method only needs a road examination can satisfy the repetition test of vehicle Fuel Consumption optimal design, and good in the Fuel Consumption comparison property of surveying with car test, this method accuracy height, simple, quick has reduced time and cost.