CN2128971Y - Computer-controling device for air-fuel ratio of gasoline engine - Google Patents

Abstract

The utility model relates to a device implementing the adaptive control on the air-fuel ratio of the gas mixture of the carburetter gasoline engine by a microcomputer by adopting the additional air method. The device can implement the control on the air-fuel ratio of the entire operating condition of the gasoline engine on the basis of unchanging the original machine without checking the air-fuel ratio to obtain the effect of reducing the oil consumption and the discharge. The system has reliable and stable work and little investment.

Description

Computer-controling device for air-fuel ratio of gasoline engine

The utility model relates to a kind of device of the carburetor gasoline engine gasoline air mixture ratio being realized self adaptive control with single chip microcomputer.

Stable performance, cost are low because Carburetor has, maintenance and characteristics such as easy to use, and therefore, in the petrol engine that China produces at present, common Carburetor is still air fuel ratio control and the regulating device that is widely adopted.The performance of Carburetor directly influences the performances such as power character, Economy and discharging of petrol engine.And the gasoline air mixture ratio that Carburetor provided can not with the required optimum value driving fit of each operating mode of motor, this latent defect of common Carburetor, general adjustment and additional mechanical device all can not solve well, and necessity of it being set up a control system is just arranged.At present, the control of air fuel ratio is needed exhaust gas oxygen sensor, and exhaust gas oxygen sensor also is to be in development and to improve the stage abroad, the price height, the life-span is short and problem such as poor reliability awaits further researching and solving.China's research in this respect is then at the early-stage, and universal practicality is still needed the long period.

The purpose of this utility model is exactly that the performance of Carburetor is improved and improved, and designing does not a kind ofly need directly to detect air fuel ratio (promptly without exhaust gas oxygen sensor), and the microcomputer air fuel ratio adaptive controller of enough control accuracies is arranged.Obtain the effect that reduces oil consumption, reduces discharging.

This air fuel ratio adaptive controller, with the Carburetor in the motor (3), storage battery (5), flywheel (8) has connecting relation, control section comprises Control System of Microcomputer (6), engine load sensor (4), speed probe (7), linear electromagnet (2), be contained on the flywheel casing speed probe and with the engine load sensor of throttle plate pin interlock be that Control System of Microcomputer (6) provides input signal, Control System of Microcomputer (6) provides the current signal of control linear electromagnet (2), and wherein Control System of Microcomputer (6) is by the tach signal processing circuit, the throttle opening signal processing circuit, with the single chip microcomputer is the central unit of principal controller, insulating power supply, solenoid driver circuit is formed.Speed probe (7) is one to be installed in the magnetoelectric transducer on the flywheel casing, and its sine wave output is converted to square wave through the rotating speed processing circuit, detects its square wave frequency with microcomputer, is scaled rotating speed then.With throttle opening as load signal, engine load sensor (4) be one with the linear potentiometer of throttle plate pin interlock, treated circuit conversion is 0～5 volt voltage, imports central unit.

The input signal of this device is tach signal and throttle opening signal, the output control signal is the electric current that inputs to linear electromagnet (2), determine control signal according to engine operating condition and feedback signal different, guarantee that gasoline air mixture ratio is an optimum value under various operating modes.

The executive component of this device is an additive air valve of being handled by linear electromagnet (2).According to the needs of control, linear electromagnet (2) can be controlled the aperture of additive air valve continuously pari passu.This valve is contained between Carburetor and the suction tude, by changing the aperture of additive air valve, can change the additive air amount and influence the oil pump capacity of Carburetor (3), thereby reach the purpose of control air fuel ratio.

Electrical interference signal on the automobile is very strong, and for microcomputer that uses on the automobile and relevant interface circuit thereof, if directly utilize the car accumulator power supply, The whole control system can't the work of normal reliable ground.For this reason, develop and used the inversion insulating power supply that can guarantee the work of vehicle microcomputer control system normal reliable.Insulating power supply is as the load of storage battery (5), for central unit, rotating speed and throttle opening processing circuit and solenoid driver circuit provide power supply.

Below in conjunction with embodiment and accompanying drawing the utility model is described in further detail.

Accompanying drawing 1 control gear structured flowchart.

Accompanying drawing 2 control gear totally connect figure.

Adjust characteristic from fuel and learn, the moment of torsion of motor and specific fuel consumption are respectively and exist certain function relation between the air fuel ratio.Under the certain condition of the resisting moment of motor and throttle opening, air fuel ratio changes the change in torque that causes and will reflect on change in rotational speed.This installs constantly online acquisition engine speed and two signals of throttle opening, according to the currency and the variable quantity thereof of throttle opening and rotating speed, the aperture of additive air valve is constantly adjusted.

When surpassing relevant setting value (being equivalent to people for a change throttle opening and load variations respectively), throttle opening and change in rotational speed value carry out open loop control.When throttle opening very little, and engine speed is when being higher than certain certain setting value (so-called forced idling mode), and this device can make the additive air valve opening for maximum, can reduce closure final vacuum degree, then avoid fuel oil to be sucked out, reach the purpose of forced idling fuel-economizing.

When throttle opening and rotation speed change value during less than certain certain setting value, this device carries out closed-loop adaptation control to the additive air valve opening.Middle or small load is a feedback signal with the second order finite difference that additive air changes the rotating speed that causes, seeks the consumption minimization point on the fuel adjustment characteristic curve, reaches the purpose that reduces oil consumption.Big load, the first difference that changes the rotating speed that causes with additive air at full capacity are feedback signal, seek fuel and adjust maximum torque point on the characteristic curve, reach the purpose that Economy when increasing power character or guaranteeing power character has change.Idling is limited to feedback signal with the single order that additive air changes the rotating speed that causes, seeks the maximum air fuel ratio under the engine idle steady running condition, reaches the purpose that reduces discharging (mainly being CO).

The utility model is an additional regulating device to original air fuel ratio control of motor and regulating device (Carburetor (3)).When this device was installed, this body structure of motor was without any need for change.Even the native system operational failure does not influence former machine performance yet.Can finish by conversion software for dissimilar motors, hardware does not need big change.By certain six-cylinder gasoline engine stand test is shown: the fuel-economizing of mapping characteristics overwhelming majority operating mode is more than 10%, and economic limit significantly enlarges; The full load operating mode, power character does not have reduction, and Economy is slightly taken on a new look; It is about 30% that middle or small load, HC discharging reduce, and the CO discharging reduces about 40%; Idling operation discharges under the constant substantially condition at HC, and the CO discharging reduces more than 40%, is lower than emission standard, and motor road test shows: fuel-economizing 7.3%.Adopt single chip microcomputer and insulating power supply, and, make the control system hardware investment minimum and stable and reliable for performance in conjunction with reasonably software programming.Illustrate that this device economic benefit of employing is obvious.In addition, this system expands the function that also can have other related system a little.

Claims (5)

1, a kind of Air Fuel Ratio of Gasoline Engines microcomputer automatic adaptation control gear comprises Carburetor (3), storage battery (5), flywheel (8) and control section in the motor: i.e. Control System of Microcomputer (6), engine load sensor (4), speed probe (7), linear electromagnet (2); It is characterized in that: described speed probe is arranged on the shell of flywheel (8), in order to control system sine wave output signal, described engine load sensor and throttle plate pin interlock are to the control system output voltage signal, and the output signal of control system then is the electric current of control linear electromagnet (2).

2, air-fuel ratio control device according to claim 1, it is characterized in that Control System of Microcomputer (6) is made up of tach signal processing circuit, throttle opening signal processing circuit, the central unit based on single-chip microcomputer, insulating power supply, solenoid driver circuit.

3, Control System of Microcomputer according to claim 2 (6) is characterized in that this device also comprises an inversion insulating power supply that several different output voltages are arranged; This insulating power supply is as the load of storage battery (5), for central unit, tach signal processing circuit, throttle opening signal processing circuit, solenoid driver circuit provide power supply.

4, air-fuel ratio control device according to claim 1 is characterized in that, this device has an executive component, and this element is an additive air valve by linear electromagnet (2) manipulation; Linear electromagnet (2) is action in proportion continuously, finishes the quantitatively accurately control to additive air; The residing position of linear electromagnet (2) is corresponding with control signal, and according to the needs of control, the additive air valve changes between standard-sized sheet arrives to full cut-off.

5, air-fuel ratio control device according to claim 1 is characterized in that, speed probe (7) is one to be contained in the magnetoelectric transducer on the flywheel casing, and its output signal is converted to square signal after treatment, measures its square wave frequency, is scaled rotating speed again; Engine load sensor (4) be one with the linear potentiometer of throttle plate pin interlock, its output signal is converted to 0～5 volt voltage after treatment, imports central unit.