A method of ignition control for a carbureted aero-piston engine

Abstract

The application provides a kind of ignition control method of carburetor type aviation piston engine, obtains performance parameter and inquires preset parameter table to obtain ignition energy basic value and ignition advance angle basic value;Again, the correction value of ignition energy basic value is calculated according to performance parameter, and the corrected ignition energy calculation value is converted into ignition pulse width by the discharge voltage of ignition controller;The correction value of ignition advance angle basic value is calculated according to performance parameter, and the sum of correction value data is the ignition advance angle calculation value of ignition output;Finally, the engine is ignited according to ignition pulse width and ignition advance angle. Ensure that the engine ignition control system obtains the best ignition pulse width calculation value and ignition advance angle calculation value under different working conditions, so that the engine is in the best working condition.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine ignition control, in particular to an ignition control method of a carburetor type aviation piston engine. BACKGROUND

[0002] The time of engine spark plug continuous discharge (ignition duration) is called engine ignition pulse width. The angle of crankshaft rotation from the ignition time to the piston reaching the compression top dead center is called ignition advance angle. The rationality and control accuracy of ignition advance angle directly affect the power, economy and emission of the engine. If the ignition advance angle is too large, the combustion is carried out during the compression process, the pressure in the cylinder rises sharply, and the maximum pressure is reached before the piston reaches the top dead center, which gives a large resistance to the rising piston, not only reduces the engine power and increases the fuel consumption, but also causes the knock. If the ignition advance angle is too small, the mixture burns when the piston is descending, that is, the combustion is carried out when the volume is increasing, so that the pressure in the cylinder is reduced, the engine power is reduced, and the exhaust temperature is increased due to the increased contact area between the hot gas and the cylinder wall, the heat loss is increased, resulting in overheating of the engine and reduction of power. Due to the difference of engine actual operation condition and environment (environmental temperature, humidity and altitude, etc.), the best ignition pulse width and the best ignition advance angle of the engine output are also different.

[0003] The ignition control system of the carburetor type aviation piston engine is composed of a trigger, an ignition controller, an ignition coil and a spark plug. The output ignition energy is fixed and cannot be changed with the change of engine operating condition. The ignition controller is an electronic device for controlling the operation of each part of the engine. Its basic function is to realize data collection and interaction by using various sensors, to determine the best ignition advance angle and ignition duration, and to send an ignition signal to the ignition controller at the appropriate time. The aviation engine works under variable altitude and multi-condition conditions. Altitude and temperature directly affect the engine intake. The existing control method cannot adjust according to the differences and gradual characteristics of the actuator and related sensors, and cannot ensure that the engine is in the best working condition. SUMMARY

[0004] In view of the above technical problems, the purpose of the present application is to provide an ignition control method of a carburetor type aviation piston engine, which solves the problem of unable to adjust the ignition energy of the carburetor type aviation piston engine.

[0005] In order to achieve the above technical purpose, the present application adopts the following technical scheme:

[0006] An ignition control method of a carburetor type aviation piston engine, comprising the following steps:

[0007] Firstly, performance parameters of the carbureted aero-piston engine are obtained.

[0008] Secondly, according to the performance parameters, a preset parameter table is inquired to obtain a basic value of ignition energy and a basic value of ignition advance angle.

[0009] Thirdly, a correction value of the basic value of ignition energy is calculated according to the performance parameters, and a corrected ignition energy calculation value is converted into an ignition pulse width through a supply voltage of an ignition controller; a correction value of the basic value of ignition advance angle is calculated according to the performance parameters, and a sum of the correction value data is an ignition advance angle calculation value of ignition output.

[0010] Fourthly, the engine is ignited according to the ignition pulse width and the ignition advance angle.

[0011] Further, the first step specifically includes obtaining performance parameters that can reflect combustion in a cylinder of the engine and changes in load of the engine.

[0012] In order to make the engine work in a better state, the performance parameters at least include a rotating speed.

[0013] In order to make the engine work in a better state, the performance parameters further include a cylinder temperature, an intake pressure and an intake temperature.

[0014] In order to make the engine work in a better state, the process of obtaining the ignition advance angle further includes the following steps: in a take-off working condition of the engine, a correction value of the intake temperature to the ignition advance angle and a correction value of the cylinder temperature to the ignition advance angle are cleared.

[0015] In order to make the engine work in a better state, the ignition output includes ignition 1 output and ignition 2 output, and an ignition advance angle calculation value of the ignition 2 output = an ignition advance angle calculation value of the ignition 1 output + a working condition difference value.

[0016] In order to make the engine work in a better state, the process of obtaining the ignition advance angle further includes the following steps: the working condition difference value is obtained according to the intake pressure and the rotating speed obtained in real time by inquiring a preset two-dimensional MAP table.

[0017] Compared with the prior art, the engine ignition controller obtains data through a sensor, calculates influences of various factors on correction values of the ignition pulse width and the ignition advance angle in real time, ensures that the engine ignition control system obtains optimal ignition pulse width calculation values and ignition advance angle calculation values in different working conditions, and makes the engine in an optimal working state. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The ignition control method flowchart provided for the embodiment of the application is shown. DETAILED DESCRIPTION

[0019] The present application will be further described below in connection with the drawings and specific embodiments. However, the following description of the embodiments is only used to help understand the principles of the present application and its core ideas, and is not intended to limit the scope of the present application. It should be noted that for those skilled in the art, improvements made to the present application without departing from the principles of the present application also fall within the scope of the claims of the present application.

[0020] Embodiment: As shown in the figure, the ignition control method provided by the embodiment is applied to a carburetor type aviation piston engine, and includes the following steps: Figure 1

[0021] Step S01, obtaining the speed, cylinder temperature, intake pressure and intake temperature of the carburetor type aviation piston engine. In this step, the speed is obtained by a crankshaft position sensor, the intake temperature is obtained by an intake temperature sensor, the intake pressure is obtained by an intake pressure sensor, and the cylinder temperature is obtained by a cylinder temperature sensor.

[0022] Step S02, according to the intake pressure and the speed, querying a preset parameter table to obtain a basic value of ignition energy and a basic value of ignition advance angle. The cylinder temperature, intake temperature and speed can reflect the combustion condition in the engine cylinder, and the speed can also reflect the change of the engine load. The key factor to determine the ignition advance angle is the speed, and on this basis, the intake pressure and other performance parameters can be referred to. A series of calibration data corresponding to the basic value of ignition energy and the basic value of ignition advance angle are set in the parameter table, and the table can be quickly determined. When other factors are not considered, the basic value of engine ignition energy and the basic value of ignition advance angle stored in the preset parameter table of the ignition controller according to different intake pressures and speeds are the best ignition pulse width and the best ignition advance angle, but the actual best ignition pulse width and the best ignition advance angle of the engine need to be calculated and corrected according to other factors.

[0023] Step S03, calculating a correction value of the basic value of ignition energy according to the intake temperature and the cylinder temperature, and increasing the ignition energy according to the speed in the starting condition. The calculated value of the corrected ignition energy is converted into the ignition pulse width through the discharge of the supply voltage of the ignition controller; and calculating a correction value of the basic value of ignition advance angle according to the overspeed, intake temperature and cylinder temperature.

[0024] In the case of overspeed of the engine, the time for turning the same angle becomes shorter, and the ignition advance angle needs to be reduced.

[0025] When the engine runs at a lower intake temperature, the ignition advance angle needs to be increased; when the engine runs at a higher intake temperature, the ignition advance angle needs to be reduced.

[0026] ​When the engine operates at a lower cylinder temperature, the ignition advance angle needs to be increased; when the engine operates at a higher cylinder temperature, the ignition advance angle needs to be reduced.

[0027] The sum of the correction value data is the optimal ignition advance angle calculation value of the ignition 1 output in the fault-free state. The optimal ignition advance angle = ignition advance angle basic value + speed overspeed correction value + intake temperature correction value + cylinder temperature correction value. After determining the optimal ignition advance angle, it is output to the ignition device, and the ignition device uses the obtained optimal ignition advance angle to perform ignition operation, so that the carbureted aviation piston engine operates in the best working condition.

[0028] The ignition output includes ignition 1 output and ignition 2 output. When the ignition 1 output fails, it does not affect the ignition 2 output; when the ignition 2 output fails, it also does not affect the ignition 1 output.

[0029] The ignition advance angle calculation value of the ignition 2 output = the same ignition advance angle calculation value as the ignition 1 output + working condition difference value. The working condition difference value is obtained by querying the preset two-dimensional MAP table according to the real-time obtained intake pressure and speed. The two-dimensional MAP table has intake pressure as the horizontal coordinate and speed as the vertical coordinate. The ignition output failure is determined by the following method: the output control port voltage > preset value, and the duration > preset value, then it is determined that the ignition output has a short circuit fault to the power supply; the output control port current < preset value, and the duration > preset value, then it is determined that the ignition output has an open circuit fault; the output port current > preset value, and the duration > preset value, then it is determined that the ignition output has a short circuit fault to the ground; the output port voltage < preset value, and the duration > preset value, then it is determined that the ignition output has a short circuit fault to the ground.

[0030] Step S04, the engine is ignited according to the ignition pulse width and the ignition advance angle, and the ignition controller limits the ignition pulse width according to the engine speed and the ignition pulse width MAX value.

[0031] In the engine take-off working condition, the correction value of the intake temperature to the ignition advance angle and the correction value of the cylinder temperature to the ignition advance angle are zeroed.

Claims

1. A method for ignition control of a carbureted aero-piston engine, comprising the following steps: Step 1: obtaining performance parameters of the carbureted aero-piston engine; Step 2: obtaining a basic value of ignition energy and a basic value of ignition advance angle according to the performance parameters by consulting a preset parameter table; Step 3: calculating a correction value of the basic value of ignition energy according to the performance parameters, and converting the corrected ignition energy calculation value into an ignition pulse width through a discharge conversion of a power supply voltage of an ignition controller; calculating a correction value of the basic value of ignition advance angle according to the performance parameters, and adding the correction value data to obtain a calculation value of the ignition advance angle of an ignition output; the ignition output comprises an ignition 1 output and an ignition 2 output, and the calculation value of the ignition advance angle of the ignition 2 output = the same calculation value of the ignition advance angle of the ignition 1 output + a working condition difference value; the process of obtaining the ignition advance angle further comprises the following steps: in an engine take-off working condition, clearing the correction value of the ignition advance angle with respect to an intake temperature and the correction value of the ignition advance angle with respect to a cylinder temperature; Step 4: igniting the engine according to the ignition pulse width and the ignition advance angle.

2. The ignition control method of a carburetted aero-piston engine according to claim 1, characterized in that, The specific steps of Step 1 are: obtaining performance parameters that can reflect the combustion condition in the engine cylinder and the load change condition of the engine.

3. The ignition control method of a carburettor-equipped aero-piston engine according to claim 1 or 2, characterised in that, The performance parameters at least comprise a rotating speed.

4. The ignition control method of a carburettor-equipped aero-piston engine according to claim 1 or 2, characterised in that, The performance parameters comprise a cylinder temperature, an intake pressure and an intake temperature.

5. A carburettor ignition control method for an aero-piston engine according to any one of claims 1-4, characterized in that: The working condition difference value is obtained by consulting a preset two-dimensional MAP table according to the real-time obtained intake pressure and rotating speed.

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