CN112504690B - A test method for minimum curve of engine fuel consumption rate - Google Patents

Abstract

Aiming at the problem of how to quickly test the minimum fuel consumption curve of the engine at low cost when the minimum fuel consumption curve of the engine is optimized, the invention provides a method for quickly testing the minimum fuel consumption curve of the engine at low cost.

Description

A test method for minimum curve of engine fuel consumption rate

technical field

The invention relates to a measurement technology, in particular to a method for testing the minimum curve of the engine fuel consumption rate.

Background technique

Saving energy, reducing pollution and protecting the environment have become the most urgent issues facing the world's automobile industry and even the entire human race. Improving the fuel efficiency of the engine when it is working has received more and more attention from governments. Chinese Patent Publication No. CN 110761906A, published On February 07, 2020, the name of the invention is a control method for improving engine fuel efficiency. The invention discloses a method that uses the actual throttle opening of the engine to determine the throttle opening and engine speed based on the electronic throttle output signal. The throttle opening weighted result method determined by the principle of the minimum fuel consumption rate can improve the fuel efficiency of the engine. The actual throttle opening can be regarded as the control result of the weighted throttle signal. The disadvantage is that when testing the minimum fuel consumption rate curve of the engine, it usually needs The process of measuring the actual fuel consumption and passing the actual fuel consumption test curve is time-consuming, labor-intensive and expensive, which is not conducive to customizing the corresponding weighted accelerator for hundreds of millions of cars on the market.

Contents of the invention

Technical problem to be solved

The technical problem to be solved by the invention is that when the throttle of the automobile engine adopts the weighted throttle, the minimum curve of the fuel consumption rate of the engine can be tested quickly and at low cost.

Technical solutions

The method of off-line testing the minimum curve of vehicle fuel consumption rate is to control the electrical signal output by the traditional electronic accelerator pedal and fix it at V1, and control the loading device of the automobile chassis dynamometer so that the axle speed is stable within the allowable range from small to large. Different values , looking for the engine speed N1 when the fuel consumption rate of the engine is the minimum, a point on the minimum fuel consumption rate curve can be determined by (V1, N1), and the electric signal output by the accelerator pedal is changed in turn and stabilized at V2, V3,... ., Vm, in order to find the engine steady-state speed N2, N3, ..., Nm when the fuel consumption rate is minimum, for these m points ((V1, N1), (V2, N2), .... .., (Vm, Nm)) curve fitting, the minimum fuel consumption rate curve can be obtained. When calculating the fuel consumption rate, the fuel consumption is set in real time, and the value of the curve is loaded into the circuit board controller of the weighted throttle to participate in the actual run.

Beneficial benefits

When the above-mentioned technical solution is adopted, it will become a reality to convert the throttles of hundreds of millions of cars in the market into weighted throttles, and the effect of energy saving and emission reduction will be very obvious, and the cost is low, and the method is simple and easy.

Detailed ways

The minimum fuel consumption rate curve of the engine is the corresponding relationship between the instantaneous fuel injection quantity of the engine and the engine speed when the fuel consumption rate of the engine is minimum. Based on the minimum fuel consumption rate curve, the fuel injection quantity is set by the engine speed. It is an open-loop control method to test fuel consumption. When the rate is the minimum curve, disconnect the oxygen sensor output signal.

The real-time setting value of the basic fuel injection quantity is:

（1）

(1)

是进气量，

是比例常数，

是发动机转速，考虑了修正油量和增加油量后的喷油量实时设定值为：In the above formula:

is the intake air volume,

is the constant of proportionality,

is the engine speed, and the real-time setting value of the fuel injection quantity after considering the corrected fuel quantity and the increased fuel quantity is:

（2）

(2)

是修正油量系数，

，

是增加油量系数，

，测试是在发动机启动后，暖机过程结束，地点不变，持续时间短，又依次固定油门开度在不同值，改变发动机负载来改变发动机转速的条件下，寻找每个油门开度燃油消耗率最小且稳态时的速度值，所以在测试曲线上每个点的过程中参数

是常数。In the above formula:

is the corrected oil quantity coefficient,

,

is the increase in oil quantity coefficient,

, the test is after the engine is started, the warm-up process is over, the location remains the same, the duration is short, and the throttle opening is fixed at different values in turn, and the engine load is changed to change the engine speed to find the fuel consumption of each throttle opening. The speed value at the time of minimum rate and steady state, so the parameters in the process of each point on the test curve

is a constant.

Instantaneous fuel consumption rate

（3）

(3)

是瞬时喷油量设定值，用汽车底盘测功机测试曲线时，

是测功机瞬时输出功率折算到发动机输出端的功率，

是测功机瞬时输出扭矩折算到发动机输出端的扭矩,

是测功机瞬时输出转速折算到发动机输出端的转速，在机械传动效率确定的情况下，寻找一定进气量

，即实际节气门开度

不变，不同转速时

的最小值，等价于寻找

的最大值，

最大时的发动机转速

与实际节气门开度

确定曲线上的一个点，依次改变实际节气门

并固定，再寻找燃油消耗率最小时与其对应的转速

来确定曲线上的其它点，对这些点曲线拟合，实际运行时，将曲线数据下载到加权油门电路板控制器中，电路板控制器实时采集发动机转速信号，基于燃油消耗率最小曲线确定最优节气门开度信号，与传统电子油门的信号加权后作为实际节气门控制信号。In the above formula:

is the set value of the instantaneous fuel injection quantity, when the curve is tested with a chassis dynamometer,

is the power converted from the instantaneous output power of the dynamometer to the output end of the engine,

is the torque converted from the instantaneous output torque of the dynamometer to the output end of the engine,

It is the speed converted from the instantaneous output speed of the dynamometer to the output end of the engine. When the mechanical transmission efficiency is determined, it is necessary to find a certain amount of air intake

, that is, the actual throttle opening

constant, at different speeds

The minimum value of is equivalent to finding

the maximum value of

Engine speed at maximum

vs actual throttle opening

Identify a point on the curve and change the actual throttle in turn

And fix it, and then look for the corresponding speed when the fuel consumption rate is the minimum

To determine other points on the curve, and to fit these points, the curve data will be downloaded to the weighted accelerator circuit board controller during actual operation, and the circuit board controller will collect the engine speed signal in real time, and determine the minimum fuel consumption rate based on the curve. The optimized throttle opening signal is weighted with the traditional electronic throttle signal as the actual throttle control signal.

There is a one-to-one correspondence between the intake air volume and the throttle opening, and the relationship between the throttle opening and the electric signal output by the throttle. During the test, a controllable analog electric signal can be used instead of the electric signal output by the throttle to test the fuel. The minimum consumption rate curve is the corresponding relationship curve between the electrical signal output by the throttle and the engine speed when the engine fuel consumption rate is minimum.

Claims (1)

1. A minimum curve test method of engine fuel consumption rate, characterized in that, in the test process, the fuel consumption adopts a real-time set value when calculating the fuel consumption rate, and is fixed at V1 by controlling the electric signal output by the traditional electronic accelerator pedal , control the loading device of the automobile chassis dynamometer, so that the axle speed stabilizes at different values within the allowable range from small to large, and find the engine speed N1 when the engine fuel consumption rate is the minimum, and a minimum fuel consumption rate can be determined by (V1, N1) Points on the curve, sequentially change the electric signal output by the accelerator pedal and stabilize it at V2, V3, ..., Vm, and search for the steady-state engine speed N2, N3, ... when the fuel consumption rate is the minimum in sequence , Nm, for these m points ((V1, N1), (V2, N2), ..., (Vm, Nm)) curve fitting, the minimum fuel consumption curve can be obtained.