CN101706300A

CN101706300A - Method for detecting constant-speed full-load fuel consumption rate of automobile

Info

Publication number: CN101706300A
Application number: CN200910205135A
Authority: CN
Inventors: 吴明
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-09-28
Filing date: 2009-09-28
Publication date: 2010-05-12
Anticipated expiration: 2029-09-28
Also published as: CN101706300B

Abstract

A method for detecting the constant-speed full-load fuel consumption rate of an automobile includes such steps as engaging the high-speed gear of speed variator to chassis dynamometer, detecting the fuel consumption of the automobile in a set time at a set middle speed point under the full-load condition of engine at the position of maximum accelerator pedal, measuring the output power of the driving wheel of the full-load automobile at a set speed point, measuring the power loss of the whole system of the automobile and the bench at the set speed point, setting the power loss of accessories of the engine at the set speed point, adding the three powers, correcting the power in standard state to obtain the output power of the engine at the speed point, calculating the full-load fuel consumption rate of the engine, and obtaining the load ratio of the engine.

Description

Detection method of automotive constant speed full load fuel consumption rate

Technical field

This method is that automobile is on chassis dynamometer, hang up under the wheel box top gear maximum throttle pedal position full engine load operating mode, detect automobile fuel consumption at the appointed time in regulation middling speed constant speed, by detecting the output power of vehicle motor, thereby calculate a kind of detection method of automotive constant speed full load fuel consumption rate, belong to automobile bench teat economic performance detection method technical field.

Background technology

Existing automobile fuel consumption of 100km detects, be that automobile is on chassis dynamometer, hang up wheel box top gear middling speed constant speed, load in the road examination of regulation speed of a motor vehicle bench teat simulating vehicle, under part accelerator pedal position engine section load condition, detect the automobile fuel consumption of 100km, the error of following several respects arranged:

(1) regulation speed of a motor vehicle point is set the error of vehicle road test system resistance.

(2) error of regulation speed of a motor vehicle point bench test system resistance.

(3) composition error of regulation speed of a motor vehicle point vehicle bench teat simulation road test system resistance.

(4) the vehicle road examination fuel consumption of 100km discreteness of same vehicle series different automobile types is bigger, estimates with the determined average limit of vehicle series statistics, and the accuracy that has many vehicles to estimate is too low.

For eliminating the influence of above-mentioned error, improve accuracy and operability that the automobile constant speed fuel economy detects and judges, the innovation detection method of automotive constant speed full load fuel consumption rate.

Summary of the invention

The quality of vehicle in use fuel economy, depend primarily on the quality of engine and chassis power train technology status, design factor for In-Use Motor Vehicles profile and vehicle weight can't change, do not consider these factors, the main factor that influences the vehicle in use fuel economy is the technology status of engine.

The good engine of various model technology status, under full load and sub-load, engine fuel consumption rate g when test can obtain each specific throttle position _eAnd the curve between the rotating speed, referring to Figure of description, thereby form family of curves, after condition of the engine descends, test still can obtain a sets of curves family of corresponding load, the good family of curves of the relative technology status of this family of curves moves on the whole, the g under each same speed of a motor vehicle point and same load condition _eRise, thereby cause each operating mode load fuel consumption of automobile to increase.By Figure of description as can be known, about full load minimum specific fuel consumption rotating speed near curvilinear motion milder, and the engine speed of minimum specific fuel consumption correspondence and engine torque capabilities might point rotating speed are close.By the minimum specific fuel consumption of detection and Control of Automobile full engine load operating mode, control whole fuel consumption g _eWith move scope in the engine speed graph family, thereby guarantee the fuel consumption of motor car engine under various operating modes, reach the vehicle energy saving effect.

The full load minimum specific fuel consumption g of the various model different capacity motor car engines of identical fuel oil and structure type _EmBasic identical, g _EmThe level of aggregation of be concentrated expression engine design and manufacturing, can roughly be divided into usually non-automatically controlled or automatically controlled dissimilar, the g of same type _EmUsually engine design and make the average level minimum specific fuel consumption ± 5% scope in, the technology height can not differ too big, determines limit value with this rule, then the accuracy for limit value provides good foundation.

Detection method of automotive constant speed full load fuel consumption rate is: vehicle hangs up the wheel box top gear on chassis dynamometer, stablizes the maximum throttle pedal position under the full engine load operating mode, and the regulation speed of a motor vehicle is put corresponding engine speed at full load minimum specific fuel consumption g _EmNear the engine speed point, constant speed is measured regulation speed of a motor vehicle point automobile driving wheel driving force and output power kW, simultaneously measuring gage interior fuel consumption Q Δ t second that fixes time _E1G, measured automobiles and stand whole drive system are set in the engine accessory power rating resistance and the loss power kW of regulation speed of a motor vehicle point at the resistance and the loss power kW of regulation speed of a motor vehicle point then, these three kinds of power additions are gone forward side by side after the power correction under the column criterion situation, obtain motor car engine output power P _E1, calculate motor car engine full load fuel consumption rate g _E1=3600 * Q _E1/ (Δ t * P _E1), g/ (kWh), and can obtain the engine load ratio.

1, the concrete steps of detection method of automotive constant speed full load fuel consumption rate:

(1) behind the hot machine of vehicle, reach on the cylinder of chassis dynamometer, wheel box hangs up the high speed gear, be generally direct retaining, step on maximum position and be stabilized in this position of throttle, the device for power absorption of chassis dynamometer loads gradually, makes the speed of a motor vehicle be stabilized in the middling speed speed of a motor vehicle point of regulation, usually in 45km/h～65km/h scope.

(2) after constant speed is stablized, in official hour, measure fuel consumption Q _E1, the average output power P of while measured automobiles driving wheel _DWith driving force F _DCan adopt freedom and twice coastdown of loading, twice constant force to load coastdown, twice coastdown of increase and decrease inertia, anti-steady state measurement method, a coastdown (the known chassis dynamometer equivalent inertia and the vehicle chassis power train equivalent inertia of examining) any method wherein of dragging then, measured automobiles and stand whole drive system are at the resistance F of regulation speed of a motor vehicle point _fWith loss power P _f

(3) be set in the engine accessory power rating loss power P that the regulation speed of a motor vehicle is put corresponding engine speed point _a=δ P _e, P _eBe rating of engine kW, δ is an engine accessory power rating loss power coefficient, and δ the power correction under three kinds of laggard column criterion states of power addition, obtains this speed of a motor vehicle point vehicle motor output power P in 0.05～0.08 scope usually _E1

(4) calculate motor car engine full load fuel consumption rate g _E1=3600 * Q _E1/ (Δ t * P _E1), g/ (kWh) compares and estimates with regulation full engine load fuel consumption limit value.Press vehicle equivalent weight torque dynamic property and detect and evaluation method, can obtain engine load ratio M _E/ M _m, M _EBe the engine torque that regulation speed of a motor vehicle point is surveyed, M _mBe engine torque capabilities might.

2, the technical characterstic of this method

(1) because vehicle is numerous, the various vehicles of same vehicle series differ greatly, existing fuel consumption of 100km detection method can't accurately be set the SR of institute's inspection vehicle road examination, and the composition error of bench teat simulating vehicle road test system resistance is bigger, and there are not these errors in our rule.

(2) influence factor of vehicle fuel consumption of 100km is a lot, numerous factor affecting such as vehicle external form, weight, engine capacity, tire are arranged, different automobile types series has different fuel consumption ofs 100km, same vehicle series different automobile types has different fuel consumption ofs 100km, the factor of seeking the limit value rule is too many, has a strong impact on the accuracy of limit value.This method can be according to existing technical merit of engine fuel economy and production level, determine motor car engine full load fuel consumption rate average limit exactly, the discreteness of the relative mean value of actual motor car engine full load fuel consumption rate reduces greatly, has improved the accuracy that detects and judge greatly.

(3) this method need not the constant force control that fuel consumption of 100km detects, simplified the automatic control requirement of equipment, do not need to adjust and the steady component throttle position yet, make simple to operate stable, and, can detect three-in-one operation with Automobile Dynamic Performance Measurement and bench teat simulation road examination coasting distance, improve detection efficiency and operability greatly.

Description of drawings

Figure of description is the speed characteristic curve of two kinds of loads of diesel vehicle, and wherein curve 1 is full-power g _e, M _eCurve, curve 2 are the g of 55% load _e, M _eCurve, M _eBe engine output torque, Nm, g _eBe fuel consumption, g/ (kWh), n are engine speed, r/min.By curve as can be known: the engine speed of nominal torque point and g _EmEngine speed be close g _eCurve is milder with the variation of the speed of a motor vehicle, the relative g of engine speed of the regulation gear and the regulation speed of a motor vehicle _EmCertain error of engine speed is little to detecting the fuel consumption influence.

Embodiment

To detect one 1070 serial diesel-powered truck is example, the rated power P of this lorry diesel motor _e=96kW, rated speed n _e=3400r/min, nominal torque M _m=280Nm, the nominal torque rotation speed n _m=1900r/min, main reducing gear ratio of gear i ₀=6.142, wheel box 4 retaining ratio of gear i ₄=1, tire calculates radius R=0.38m, and the full engine load minimum specific fuel consumption is 221g/ (kWh), and the minimum specific fuel consumption engine speed range is about 1700r/min～2200r/min.

1, adopting directly, retaining 50km/h speed of a motor vehicle point constant speed detects automobile driving wheel output power 50.3kW, behind constant speed and power stability, 30 seconds fuel consumption of continuous coverage is 150.7mL, presses diesel oil density 0.845kg/L and calculates, and fuel consumption is G=150.7 * 0.845=127.3g.

2, adopt twice coastdown of increase and decrease inertia to record vehicle with the stand total system is 8.6kW at the loss power of 50km/h speed of a motor vehicle point, the engine loss power of setting 50km/h speed of a motor vehicle point is 0.06P _e=5.76kW, detected state and standard state are more or less the same, and simplification will not be revised, and obtains engine output P _E1=50.3+8.6+5.76=64.66kW calculates g _E1=3600 * 127.3/ (30 * 64.66)=236.2g/ (kWh).

3, the regulation 4 retaining 50km/h speed of a motor vehicle and corresponding engine speed n=50 * 6.142 * 1/ (0.377 * 0.38)=2143r/min of this vehicle are in the range of speeds of full engine load minimum specific fuel consumption.

4, calculation engine load ratio, the engine torque M that surveys _E=64.66 * 9549/2143=288.1, engine load ratio M _E/ M _m=288.1/280=1.029=102.9%.

If 5 is that 1.1 * 221=243.1g/ (kWh) estimates with being not more than full load minimum specific fuel consumption limit value, this vehicle full engine load minimum specific fuel consumption increase is (236.2-221)/221=0.0679=6.79% relatively, and it is qualified to detect evaluation.

This method has the detection accuracy height, and simple and quick advantage can be applicable to measuring station to the detecting and assessing at usefulness car fuel economy.

Claims

1. The fuel consumption rate detection method at a constant speed and full load of a vehicle is a method for testing the fuel economy of a vehicle on a chassis dynamometer. The position of the accelerator pedal is under the full load condition of the engine, and the corresponding engine speed at the specified speed point is near the minimum fuel consumption rate g _em of the engine at a constant speed. The fuel consumption Q _e1 within time Δt seconds, g, then measure the resistance and loss power kW of the entire transmission system of the car and the platform at the specified speed point, set the resistance and loss power kW of the engine accessories at the specified speed point, and take this After adding the three kinds of power and correcting the power under standard conditions, the output power P _e1 of the automobile engine is obtained, and the fuel consumption rate of the automobile engine under full load is calculated g _e1 =3600×Q _e1 /(Δt×P _e1 ), g/( kW·h), and the engine load ratio can be obtained.