Engine ignition system work quality assessment and fault diagnosis method Gasoline ignition system quality of work is good or bad, directly affect the technical condition of the engine can be engine integrated detector analysis of the ignition waveform and the ignition system performance parameters to find the cause of the fault and related Parts, to achieve engine detection, adjustment or repair as appropriate, to ensure or improve the engine's power, economy and emissions performance. Combined with the research and popularization and application of the "Science and Technology Commission of the People's Republic of China on Vehicle Detection and Diagnosis Technology", the Highway Science Research Institute of the Ministry of Communications (as technical support unit) jointly developed the FDJ-B2 engine comprehensive detector with Zibo Branch Computer Applications Research Institute. The detector can detect the engine working conditions of the nearly 30 kinds of parameters and a variety of waveforms in the case of the engine does not disintegrate, is conducive to the engine failure of the "rapid diagnosis" and the maintenance of the project to determine, in vehicle maintenance and automotive inspection stations Promote the application. In this paper, an FDJ-B2 engine comprehensive detector as an example, describes the gasoline engine ignition system fault diagnosis, for reference purposes only. 1FDJ-B2 engine integrated detector principle FDJ-B2 engine integrated detector to 586 computer as the core, and sensors, signal processors and printers to form a complete set of signal detection and data analysis system. Testing through different sensors, the collected various working conditions of the engine signal, the signal processor converts the analog signal can be received by the computer digital signal, and with the appropriate software to support the completion of a variety of parameters through the keyboard to measure and measure Fault diagnosis, test results can be displayed on the screen, but also by the printer print output, its working principle shown. The detector for the detection of gasoline engine functions include: starting system, ignition system, power, charging system, gas phase, abnormal sound testing, comprehensive testing and gun test results printing. The detection of the ignition system includes: a. Full detection (engine speed, closing angle, overlap angle, ignition pressure, single cylinder power); b. Platinum Observation and analysis); c. Ignition high pressure detection; d. "Cylinder pressure method" ignition advance angle detection. The detection of diesel engines include: starting system, fuel system, power, charging system, abnormal sound testing, comprehensive testing and test results printing. 2 Gasoline engine during the firing waveform characteristics 2.1 Pinghuo Bo Pingbo is the ignition waveform of each cylinder according to the engine firing order of the horizontal arrangement of graphics used to check the ignition system, the technical status of the secondary circuit to assess the capacitors, distributor, ignition coil, Spark plugs and other components of the working performance. 2.2 Parallel wave parallel wave refers to the firing waveform of each cylinder according to the engine ignition sequence arranged from the bottom up graphics used to diagnose the size of the distributor closing angle and the working condition of each cylinder spark plug. 2.3 Overlapped wave Overlapped wave is to overlap the ignition waveform of each cylinder to the same figure, which is used to analyze and diagnose the wear of the distributor and its camshaft. The following will be the most commonly used in the actual test single-tank flat wave waveform sub-sections are as follows: A (ignition zone): breaker contacts open, the primary current decreases, the secondary circuit generates high voltage (15kV-20kV) Spark plug gap breakdown, breakdown voltage value of 8kV-10kV. B (Burning Zone): The spark plug gap is broken down causing the combustible mixture in the spark plug gap to ionize, causing arc discharge. As soon as the spark plug discharges, the secondary ignition voltage drops (3kV-4kV) and the spark plug electrode discharges The required voltage, so that the rapid combustion of the mixture within the cylinder. C (Oscillator Area): When the energy consumed to discharge the spark plug is consumed and the arc is interrupted, the residual energy in the ignition coil continues to be discharged slowly along the ionized spark plug gap, causing the residual energy to dissipate as a damped oscillation (first oscillation). D (closed area): the moment the contact is closed, the primary circuit of the ignition coil passes the current to generate a self-inductance voltage, and a corresponding reverse voltage (1.5kV-2kV) is generated in the secondary circuit and oscillations occur ). 3 engine ignition timing detection and fault diagnosis 3.1 Test items Test items are engine speed, ignition advance angle (θST) FDJ-B2 engine comprehensive detector is the use of "cylinder pressure method" principle to determine the engine at a certain speed Ignition advance angle, the angle can be altitude, temperature, gasoline octane number, car technology for proper adjustment. To EQ1090-1 car engine as an example: the engine is working normally, when the speed of 800r / min ignition advance angle of 9 °, 1200r / min ignition advance angle of 12 ° -14 °, 2000r / min ignition ahead ? Angle, and gradually increase the engine speed, ignition advance angle should be gradually larger, and should be consistent with the above normal values. 3.2 Detection of the required sensors The sensor required speed sensor, a cylinder marking sensor, cylinder pressure sensor. 3.3 Detection Method Select the "cylinder pressure advance angle detection" item, press the "Enter" key to enter the test interface, remove the 1 cylinder spark plug, the cylinder pressure sensor into the spark plug seat hole and tighten the 1 cylinder mark sensor string 1 cylinder between the high-pressure line and the spark plug, start the engine spark plug natural discharge, according to the screen prompts for testing, the screen will be measured data and waveform display. The above test data and waveform can be stored on demand, access, print. 3.4 Fault Diagnosis a. The advance angle value of each speed (including rapid acceleration and slow increase from low speed to high speed) is too small (or too large). The reasons for the failure are as follows: the distributor spring blocks tension spring, Rust dead (or spring too soft), vacuum ignition pre-adjustment device failure, leakage and so on. b. No detection of advance angle at each speed indicating failure of centrifugal and vacuum ignition pre-adjustment devices or tube leakage. In the event of any of the above faults, maintenance should be carried out, otherwise it will affect vehicle dynamics and economy. 4 Platinum (contact) parameter detection and diagnosis 4.1 test items Test items are engine speed, distributor platinum (contact) closure angle (θb), distributor overlap angle (θc), the ignition waveform. 4.2 Detection of the required sensors The sensor required speed sensor, a cylinder marking sensor. 4.3 Detection Method Select the "platinum (contact) detection" item, press the "Enter" key to confirm, in accordance with the "help" to connect the sensor, enter the test program, the measured vehicle engine speed stabilized at 1200r / min or so, press "Measurement Start" key, the computer will test results and waveforms displayed on the screen. The ignition waveform can be diagnosed against the standard waveforms listed. 4.4 Fault Diagnosis 4.4.1 Distributor platinum (contact) closure angle (θb) and its fault diagnosis The angle of the size of the impact of ignition energy, the normal θb should meet the normal ignition enough energy required, it shows the contact dynamic clearance. Such as EQ1090 car engine 1200r / min θb 36 ° -42 °, CA1090 car engine 1200r / min, θb 38 ° -42 °, the corresponding contact gap of 0.35mm-0.45mm. a. If θb is too large, the contact gap is too small. Although theoretically the ignition current can be increased by increasing the power-off current, in fact, the arc discharge occurs between the contacts, but the ignition energy is weakened instead of the normal ignition. b. If θb is too small, the contact gap is too large, making the contact closure time is short, the power supply current is small, resulting in insufficient ignition energy, the mixture of poor ignition performance caused by engine power decline. c. When the θb value and the contact gap normal corresponding relationship is destroyed, the cam has been severely worn, for the serious wear of the cam if you continue to use, it will have the following phenomena: When the contact gap adjusted to 0.35mm-0.45 mm, will result in θb is too small, the power supply current is small, the ignition energy is insufficient; when adjusted to ensure θb is 36 ° -42 °, will result in contact gap is too small, arcing occurs between the contacts, the ignition energy loss , Is not conducive to the fire. Therefore, θb 36 ° -42 ° and the contact gap of 0.35mm-0.45mm correspondence should be used as a replacement distributor cam basis. 4.4.2 distributor overlap angle (θc) and fault diagnosis The angle reflects the accuracy of each cylinder ignition time, EQ1090 car engine 1200r / min θc ≤ 3 °. Distributor overlapping angle θc increased by the following factors affect the distributor cam (hexagonal) manufacturing quality and wear degree; distributor shaft wear degree (radial, axial loose degree); distributor repair and assembly quality; camshaft distributor Transmission gear, distributor shaft gear, coupling groove technical status (degree of wear), assembly quality, and vibration in the rotation after wear. When the overlap angle θc of the distributor increases, it directly affects: a. Ignition timing and ignition uniformity of each cylinder, thus affecting the stability of engine power, economy and operation; b. Contact closure angle θb, thus affecting the ignition energy , Leading to deterioration of power and economy; c. Accuracy of other project measurements (such as dynamic measurement of gas phase). Detection, the proposed engine speed of 1200r / min when the measured value prevails, because θc addition to the above factors, with the engine speed changes, the vibration of the various parts of the electrical signal transmission and so will make θc in a Small changes in the range. When the emergence of θc> 3 ° should be timely maintenance. 5 ignition pressure value and fault diagnosis 5.1 Test items Test items are engine speed, ignition pressure of each cylinder. To ensure that sparks between two electrodes spark required voltage, known as the "breakdown voltage", commonly known as "ignition pressure." The value reflects the size of spark plug electrode gap and high voltage line, sub-head contact status, and the pressure and temperature in the cylinder. The larger the electrode gap, the higher the gas pressure in the cylinder; the lower the temperature, the higher the breakdown voltage. 5.2 Detecting the required sensors The required sensors are speed sensors and 1-cylinder marking sensors. 5.3 Test Method Select "Ignition High Voltage Test" and press "Enter" to enter "Ignition High Voltage Test" interface, the engine will be stabilized at 1200r / min or so, start the test, and the ignition high voltage data and ignition waveform of each cylinder appear on the screen. Ignition waveform of each cylinder under normal conditions, ignition high pressure value: EQ1090 engine 1200r / min for 8kV-10kV, CA1090 engine 1200r / min for 7kV-9kV, each cylinder ignition high pressure ≤ 2kV. 5.4 Troubleshooting When the spark plug electrode energy is constant, the size of the breakdown voltage Uc has a direct impact on the mixture firing performance. a.Uc is too high, mostly due to the electrode gap is too large, poor contact with high pressure line, the mixture is too thin and the cylinder pressure, temperature, mixed gas flow changes, making the spark plug electrode breakdown difficult, the required breakdown energy to large; Or smaller (poor contact loss), the energy discharged from the inductor discharge part is relatively reduced, the discharge time is shortened, the normal ignition performance is affected, and even a high-speed off-fire phenomenon occurs. b.Uc is too low, mostly due to the electrode gap is too small, drowned, short circuit caused. When the electrode gap is small and Uc is reduced, the contact area between the flame core and the electrode is large and is cooled, so that the flame core is extinguished and the ignition performance is poor. 6 Single-cylinder dynamic evaluation and fault diagnosis 6.1 Test items Test items have a decline in the value of each cylinder speed, speed reduction rate. Single cylinder power measurement is a measure of the work of the engine cylinder uniformity is good or bad indicators. Usually at a certain engine speed each cylinder were off after the fire, with the speed of decline in the value of that. After the off speed, the greater the decline, indicating off the fire cylinder impact on the entire engine speed, so the cylinder performance is good, otherwise poor. 6.2 Detection of the required sensors The sensor required speed sensor, a cylinder marking sensor. 6.3 Test Method Select "Single Cylinder Power Test", press "Enter", connect the sensor according to "Help" and press "Enter" to enter "Single Cylinder Power Test" interface, stabilize the engine at 1200r / min Or so, press the "Enter key", then press the engine according to the engine ignition sequence by cylinder off the fire, and the measured results displayed on the screen. According to the decline in the value of each cylinder to determine the work of each cylinder, the average speed drop ≥ 90r / min, the difference between the speed of each cylinder should not exceed 25% is normal. Otherwise it should be judged by other instruments or experience to identify the cause of the malfunction. 6.4 Troubleshooting a. Fuel supply system: mostly carburetor blockage, improper adjustment or other failures, resulting in poor oil, poor atomization. b. ignition system fault: Ignition coil, distributor, spark plugs, high voltage lines and other faults, affecting the normal ignition. At this time can be further testing the ignition system fault diagnosis. c. mechanical part of the fault: the cylinder compression pressure is low, poor intake and exhaust manifold seal. At this time available cylinder pressure gauge, crankcase blow-by gas measuring instrument, cylinder air leakage detector, vacuum gauge and other equipment testing diagnostic trouble.
It also has up to dive levels of heating areas that will keep the body at the required temperature. It heats faster in just three minutes; hence very efficient. It comes with remote control for easy operation.
Alloy Car Seat Heated,Alloy Heated Car Seat,Alloy Wire Car Seat Heater,Alloy Car Seat Heated Cover
JiLin Province Debang Auto Electric Co.,Ltd. , https://www.debangcarseatheating.com