Wide range air/gasoline proportionality measurement sensor for automobile

Abstract

The invention discloses an automobile wide-range air / petrol ratio measurement sensor, adopting a flat battery oxygen sensor, which comprises an oxygen pump battery formed by a solid electrolyte and at least two oxygen pump electrodes respectively formed at two side surfaces of the solid electrolyte; an oxygen measurement battery formed by a solid electrolyte, at least one induction electrode at the side surface of the solid electrolyte at a measurement cavity and at least one reference electrode at the side surface of a reference condition, wherein the oxygen pump battery and the oxygen measurement battery are parallel arranged, the oxygen pump battery is arranged more near the object gas than the oxygen measurement battery. The automobile wide-range air / petrol ratio measurement sensor can improve measurement accuracy, reduce sensor activation time, improve reliability and durability of oxygen sensors, and reduce manufacture difficulty and cost, thereby resolving the defects of the prior flat dual-battery oxygen sensors.

Description

technical field [0001] The invention relates to a wide-range air / gasoline ratio measurement sensor for automobiles, in particular to a flat-plate dual-battery oxygen sensor. Background technique [0002] Cars bring convenience and comfort to people's lives, but also bring pollution. Untreated car exhaust contains NO x , CO, hydrocarbons and other harmful gases will pollute the environment and endanger human health. Therefore, all countries have restricted the emission of harmful gases in automobile exhaust. [0003] The oxygen sensor is the abbreviation of the exhaust oxygen sensor. Its function is to obtain the air-fuel ratio signal of the gasoline / air mixture in the automobile engine by monitoring the oxygen content in the automobile exhaust, and convert the signal into an electrical signal and input it to the electronic control unit ECU. According to the oxygen sensor signal, the ECU corrects the fuel intake and realizes the air-fuel ratio feedback control, so that the e...

AI Technical Summary

Problems solved by technology

[0005] There are still many shortcomings in the existing planar dual battery oxygen sensor, so its practical application is limited

First of all, there is a large oxygen concentration gradient in the measurement cavity 3 of the existing dual-cell oxygen sensor during operation, that is, from the diffusion hole 5 to the edge of the sensor, from the inner electrode 13 of the oxygen pumping battery 1 to the oxygen measuring battery 2 The oxygen concentration between the inner electrodes 21 is distributed in a gradient, which will lead to inaccurate voltage measured by the oxygen measuring cell 2, resulting in a deviation in the measured oxygen content

Although the method of short-circuiting the inner electrode 13 of the oxygen pumping cell 1 and the inner electrode 21 of the oxygen measuring cell 2 so that the inner electrode 21 of the oxygen measuring cell 2 also participates in pumping oxygen can partially eliminate the oxygen concentration difference between the above two electrodes, but from the diffusion The oxygen concentration gradient between hole 5 and the edge of the sensor cannot be eliminated

Secondly, the existing planar double-battery oxygen sensor is a laminated structure, that is, the oxygen pumping battery 1 is superimposed on the oxygen measuring battery 2, and the oxygen pumping battery 1 is far away from the heater. When the sensor is cold started, when the oxygen measuring battery 2 has reached the operating temperature, the oxygen pumping battery 1 still needs a period of time to reach the operating temperature, so the activation time of the sensor is long, which cannot well meet the emission control requirements when the car is started

Again, the existing dual-battery oxygen sensor uses the voltage measured by the oxygen-measuring battery 2 as a comparison parameter for the external control circuit. Once the oxygen-measuring battery 2 cannot output voltage due to the disconnection of the line, the sensor will lose its working ability. The sensor will be in harsh environments such as rapid temperature rise and fall, turbulence, strong reducing atmosphere, etc., and the internal circuit is prone to disconnection and other problems. Therefore, the reliability and durability of the existing dual-battery oxygen sensor is not high

Finally, the existing dual-battery oxygen sensor is made by superimposing the oxygen pumping battery 1 on the oxygen measuring battery 2. During production, it is necessary to process multiple ceramic thin layers with different components and press them into a complete body. The production process is complicated, so the cost is also high

[0006] Chinese patent 03103722.4 mentions that when the existing flat-plate double-battery oxygen sensor is produced, the distance between the oxygen pumping battery 1 and the oxygen measuring battery 2 must be accurately controlled within a certain range, preferably 20-80 microns, otherwise It will affect the measurement accuracy of the sensor, which undoubtedly increases the difficulty and cost of sensor production

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