Fault diagnosis system and method for fuel injector of high-pressure common-rail electric injection diesel engine

Abstract

The invention relates to the technical field of diesel engine fault diagnosis, and discloses a fault diagnosis system and method for an oil injector of a high-pressure common-rail electric injection diesel engine, and the fault diagnosis system for the oil injector comprises a sensor group, a data processing and fault diagnosis unit and a human-computer interaction interface; the fuel injector fault diagnosis method comprises the following steps: running a preset learning period in a healthy state of a diesel engine, and establishing reference data corresponding to each working condition; a detection signal of the sensor group, a diesel engine rotating speed signal and a power signal are obtained in real time, the real-time metal particle concentration difference is calculated, and the current working condition is determined; and based on the reference data corresponding to the current working condition, the real-time data and the reference data are compared, fault diagnosis is conducted on the state of the oil injector, and a corresponding early warning signal is generated. According to the invention, the health state of the fuel injector can be accurately monitored on line in real time.

Description

Technical Field

[0001] This invention relates to the field of diesel engine fault diagnosis technology, and in particular to a fault diagnosis system and method for high-pressure common rail electronic fuel injection diesel engine injectors. Background Technology

[0002] As a core component of the fuel system, the injector in a high-pressure common rail electronic fuel injection diesel engine directly determines the engine's power performance, fuel economy, and emissions. Because injectors operate under harsh conditions of high pressure and high frequency for extended periods, their internal precision components are prone to wear. The resulting metal particles further exacerbate wear within the fuel system, leading to a series of malfunctions such as injector sticking, nozzle blockage, and poor sealing. Ultimately, this results in reduced engine power, increased fuel consumption, abnormal exhaust temperature, and black smoke, severely impacting equipment operation and potentially causing significant economic losses.

[0003] Currently, the industry's maintenance methods for fuel injectors mainly rely on periodic disassembly and inspection or post-failure repair. This passive maintenance model lacks foresight, often addressing issues only after a fault has occurred and caused some impact, failing to mitigate risks in advance. Existing fault diagnosis methods largely depend on analyzing macroscopic parameters such as diesel engine power, fuel consumption, and exhaust smoke. Changes in these parameters are usually the result of severe injector wear or failure, making it difficult to detect subtle anomalies in the early stages of a fault and thus unable to provide early warning.

[0004] For example, CN117212016A discloses a method for detecting the working status of injectors in a high-pressure common rail multi-cylinder diesel engine bench test, including: S1, acquiring the working status characteristics of the injector; S2, based on the status characteristics acquired in step S1, checking for power supply abnormalities, nozzle blockage, needle valve sticking, and wear based on a preset troubleshooting method; in step S1, the acquired working status characteristics include: acquiring the voltage and current values ​​of the solenoid valve working status; acquiring the combustion pressure and exhaust temperature values ​​of the in-cylinder combustion; acquiring the fuel consumption values ​​for nozzle blockage and needle valve sticking and wear; in step S2, the preset troubleshooting method includes a method for judging abnormal working status of the solenoid valve coil: detecting the voltage and current of the solenoid valve working status, comparing the measured values ​​and phase with normal values, if there is a difference after comparison, it is determined that the injector solenoid valve power supply is abnormal, otherwise it indicates that the solenoid valve power supply is normal.

[0005] However, CN117212016A mainly relies on parameters such as the voltage and current of the solenoid valve, the combustion pressure in the cylinder, the exhaust temperature, and the fuel consumption value for troubleshooting. These parameters are mostly macroscopic feedbacks after a fault occurs, and are difficult to reflect the core changes caused by early wear of the injector, which makes it impossible to achieve a true early warning. At the same time, this method is not accurate enough in locating the fault of a single injector in a multi-cylinder diesel engine, and it is also difficult to effectively distinguish different types of faults, which brings inconvenience to maintenance. For example, CN118934303A proposes a method and system for detecting oil leaks in a high-pressure common rail diesel engine. The common rail pump, distributor block, and injector are connected through the fuel supply pipeline. The distributor block is connected to the injector through the common rail pipeline in the fuel supply pipeline. Temperature sensors are installed at each branch end of the fuel supply pipeline. The temperature sensors are located on the outer layer of the high-pressure oil pipe of each fuel supply pipeline. The location of the oil leak is identified based on the temperature changes of each temperature sensor.

[0006] However, CN118934303A only identifies oil leakage faults in the fuel supply line, and its applicable scenarios are extremely limited. It cannot cover more common fault types such as injector wear, jamming, and nozzle blockage. Furthermore, its method of detecting oil leakage by temperature changes can only deal with obvious faults that have already appeared, and it also lacks early warning capabilities, making it difficult to meet the actual needs of predictive maintenance of equipment.

[0007] In summary, existing fault diagnosis methods mostly rely on analyzing macroscopic parameters such as diesel engine power, fuel consumption, or exhaust smoke opacity. Changes in these parameters are often the result of severe fuel injector wear, and therefore cannot provide early warning. Summary of the Invention

[0008] To address the aforementioned issues, this invention proposes a fault diagnosis system and method for high-pressure common rail electronic fuel injection diesel engines. This system can monitor the health status of the injectors online, in real time, and accurately, and issue early warnings at the initial stage of a fault, thereby enabling predictive maintenance and avoiding economic losses caused by amplified faults.

[0009] The technical solution adopted in this invention is as follows: A fault diagnosis system for high-pressure common rail electronic fuel injection diesel engine injectors includes: The sensor group includes a first metal particle detector, a second metal particle detector, and an exhaust temperature sensor. The first metal particle detector is installed on the high-pressure common rail of the diesel engine. Multiple second metal particle detectors are installed one-to-one on the return oil pipe of the injector of each cylinder of the diesel engine. Multiple exhaust temperature sensors are installed one-to-one on each exhaust manifold of the diesel engine. The data processing and fault diagnosis unit is configured to establish a reference metal particle concentration, reference metal particle concentration difference and reference exhaust temperature for each operating condition under the healthy state of the diesel engine, receive real-time signals from the sensor group and diesel engine speed and power signals, calculate the real-time metal particle concentration difference, determine the current operating condition by combining the diesel engine speed and power signals, compare the real-time signal under the current operating condition with the corresponding reference value, perform fault diagnosis on the injector status and generate corresponding warning signals. The human-machine interface displays information including the status of each injector, warning information, and historical data trend charts.

[0010] A method for diagnosing injector faults in a high-pressure common rail electronic fuel injection diesel engine includes: Run a preset learning cycle under the healthy condition of the diesel engine to establish benchmark data for each operating condition; The system acquires real-time detection signals from the sensor array, diesel engine speed signals, and power signals; calculates the real-time metal particle concentration difference; and determines the current operating conditions. Based on the baseline data corresponding to the current operating conditions, the real-time data is compared with the baseline data to diagnose the injector status and generate corresponding warning signals.

[0011] Furthermore, the establishment of reference data corresponding to each operating condition includes: defining each operating condition through diesel engine speed signal and power signal, recording the reference metal particle concentration of the first metal particle detector under each operating condition, recording the reference metal particle concentration of each second metal particle detector, calculating the reference metal particle concentration difference corresponding to each injector, and simultaneously recording the reference exhaust temperature of each exhaust temperature sensor.

[0012] Furthermore, the calculation of the reference metal particle concentration difference corresponding to each injector includes: subtracting the reference metal particle concentration of the first metal particle detector on the high-pressure common rail from the reference metal particle concentration of the second metal particle detector on the injector return pipe to obtain the reference metal particle concentration difference corresponding to the injector.

[0013] Furthermore, the real-time acquisition of the detection signals of the sensor group, the diesel engine speed signal, and the power signal, the calculation of the real-time metal particle concentration difference, and the determination of the current operating condition include: acquiring the real-time metal particle concentration of the first metal particle detector, the real-time metal particle concentration of each second metal particle detector, and the real-time exhaust temperature of each exhaust temperature sensor; calculating the real-time metal particle concentration difference corresponding to each injector; and simultaneously acquiring the real-time diesel engine speed signal and the power signal, and determining the current operating condition based on the real-time speed signal and the power signal.

[0014] Furthermore, the calculation of the real-time metal particle concentration difference corresponding to each injector includes: subtracting the real-time metal particle concentration of the first metal particle detector on the high-pressure common rail from the real-time metal particle concentration of the second metal particle detector on the injector return pipe to obtain the real-time metal particle concentration difference corresponding to the injector.

[0015] Furthermore, the fault diagnosis of the injector status includes injector wear diagnosis: if the real-time metal particle concentration difference corresponding to a certain injector exceeds a preset percentage of the reference metal particle concentration difference corresponding to the injector, and the real-time metal particle concentration difference shows a continuous upward trend, then it is determined that the injector has abnormal wear, and an injector abnormal wear warning signal is generated.

[0016] Furthermore, the fault diagnosis of the injector status includes fuel system anomaly diagnosis: if the real-time metal particle concentration of the first metal particle detector exceeds a preset percentage of its reference metal particle concentration, or the real-time metal particle concentration of a certain second metal particle detector exceeds a preset percentage of its corresponding reference metal particle concentration, and the corresponding real-time metal particle concentration shows a continuous upward trend, then it is determined that there is an anomaly in the fuel system, and a fuel system anomaly warning signal is generated.

[0017] Furthermore, the fault diagnosis of the injector status includes injector injection abnormality diagnosis: if the real-time exhaust temperature of the exhaust temperature sensor corresponding to a certain cylinder is significantly lower than the reference exhaust temperature corresponding to that cylinder, or significantly lower than the real-time exhaust temperature of the exhaust temperature sensor corresponding to other cylinders, and the real-time metal particle concentration of the first metal particle detector and the real-time metal particle concentration of the second metal particle detector corresponding to that cylinder are both normal, then it is determined that the injector of that cylinder is stuck in the closed position or blocked, and a corresponding warning signal is generated.

[0018] Furthermore, the fault diagnosis of the injector status includes injector drip diagnosis: if the real-time exhaust temperature of the exhaust temperature sensor corresponding to a certain cylinder is significantly higher than the reference exhaust temperature corresponding to that cylinder, or significantly higher than the real-time exhaust temperature of the exhaust temperature sensor corresponding to other cylinders, and the real-time metal particle concentration of the first metal particle detector and the real-time metal particle concentration of the second metal particle detector corresponding to that cylinder are both normal, then it is determined that the injector of that cylinder is stuck in the open position, and a corresponding warning signal is generated.

[0019] The beneficial effects of this invention are as follows: This invention integrates key information such as the concentration and concentration difference of metal particles in the high-pressure common rail and injector return pipe, and the exhaust temperature of each exhaust manifold, by setting up a multi-dimensional sensor group. Combined with diesel engine speed and power signals for multi-information fusion diagnosis, it can accurately pinpoint the fault of a specific injector and effectively distinguish between fault types such as wear, sticking, blockage, and fuel system abnormalities. This invention has the following significant advantages over existing technologies.

[0020] 1. In terms of early warning, this invention focuses on metal particles, which are the core early characteristics of injector wear. It can capture subtle anomalies in the incipient stage of failure before the injector performance has declined significantly and the macroscopic parameters have not changed significantly, thus achieving true predictive maintenance. This is in stark contrast to CN117212016A, which relies on macroscopic parameters after failure, and CN118934303A, which can only detect obvious oil leakage failures. It effectively makes up for the lack of early warning capabilities in existing technologies.

[0021] 2. In terms of precise positioning, this invention can directly locate the specific injector that is malfunctioning by setting metal particle detectors one by one on the return oil pipe of each cylinder injector. This completely solves the problem that some existing diagnostic methods are difficult to accurately locate a single faulty injector, greatly improving maintenance efficiency and shortening the troubleshooting time.

[0022] 3. In terms of fault type identification, this invention integrates relevant parameters of metal particle concentration and exhaust temperature information, which can not only detect faults, but also effectively distinguish different fault types such as injector wear, sticking, blockage, and fuel system abnormalities. In contrast, CN117212016A is difficult to accurately distinguish fault types, and CN118934303A can only target the specific fault of oil leakage. This invention has a wider range of applications and can provide clearer guidance for maintenance.

[0023] 4. In terms of reliability, the diagnostic method of multi-sensor information fusion avoids the false alarms and false alarms that may occur with single parameter or limited dimension detection. Compared with the single dimension or limited range detection of the two existing patents, the diagnostic conclusions are more reliable and can provide strong support for the stable operation of the equipment. Attached Figure Description

[0024] Figure 1 This is a flowchart of a high-pressure common rail electronic fuel injection diesel engine injector fault diagnosis method according to Embodiment 1 of the present invention.

[0025] Figure 2 This is a schematic diagram of a high-pressure common rail electronic fuel injection diesel engine injector fault diagnosis system according to Embodiment 2 of the present invention. Detailed Implementation

[0026] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments are now described. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; that is, the described embodiments are only a part of the embodiments of the invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] Example 1 This embodiment provides a fault diagnosis system for high-pressure common rail electronic fuel injection diesel engine injectors, including a sensor group, a data processing and fault diagnosis unit, and a human-machine interface, wherein: The sensor group includes a first metal particle detector, a second metal particle detector, and an exhaust temperature sensor. The first metal particle detector is installed on the high-pressure common rail of the diesel engine. There are multiple second metal particle detectors, each corresponding to one of the fuel injector return lines of each cylinder of the diesel engine. There are multiple exhaust temperature sensors, each corresponding to one of the exhaust manifolds of the diesel engine.

[0028] The data processing and fault diagnosis unit is used to establish the reference metal particle concentration, reference metal particle concentration difference and reference exhaust temperature for each operating condition under the healthy state of the diesel engine. It receives real-time signals from the sensor group and diesel engine speed and power signals, calculates the real-time metal particle concentration difference, determines the current operating condition by combining the diesel engine speed and power signals, and compares the real-time signal under the current operating condition with the corresponding reference value to diagnose the injector status and generate corresponding warning signals.

[0029] The human-machine interface is used to display the health status of each injector, alarm information, historical data trend charts, and other information, and allows users to set alarm thresholds.

[0030] It should be noted that the system achieves comprehensive monitoring of the high-pressure common rail, the return oil of each injector, and the exhaust temperature of each cylinder through the reasonable layout of multiple sensors. Combined with the working condition matching and benchmark comparison logic of the data processing unit, it can accurately locate the faults of the injectors and fuel system. The human-machine interface improves the readability and traceability of fault information, providing convenient support for users to deal with faults in a timely manner.

[0031] like Figure 1 As shown, this embodiment also provides a method for diagnosing injector faults in a high-pressure common rail electronic fuel injection diesel engine, including: Run a preset learning cycle under the healthy condition of the diesel engine to establish benchmark data for each operating condition; The system acquires real-time detection signals from the sensor array, diesel engine speed signals, and power signals; calculates the real-time metal particle concentration difference; and determines the current operating conditions. Based on the baseline data corresponding to the current operating conditions, the real-time data is compared with the baseline data to diagnose the injector status and generate corresponding warning signals.

[0032] It should be noted that this method provides a reliable reference for fault diagnosis by establishing benchmark data under various operating conditions in advance. The logic of real-time data acquisition and operating condition matching ensures the timeliness of diagnosis, while the accurate comparison between benchmark data and real-time data improves the accuracy of fault diagnosis. The overall process is scientific and reasonable, and can effectively achieve early detection and accurate judgment of injector faults.

[0033] Preferably, establishing the reference data corresponding to each operating condition includes: defining each operating condition through the diesel engine speed signal and power signal, recording the reference metal particle concentration of the first metal particle detector under each operating condition, recording the reference metal particle concentration of each second metal particle detector, calculating the reference metal particle concentration difference corresponding to each injector, and simultaneously recording the reference exhaust temperature of each exhaust temperature sensor.

[0034] Specifically, in establishing the benchmark data, the engine speed and power signals are first used as core parameters. Different operating conditions are clearly defined according to preset classification rules to ensure clear distinctions between conditions and coverage of the main operating range of the diesel engine. Under each defined condition, the concentration of metal particles detected by the first metal particle detector is continuously recorded as the benchmark metal particle concentration corresponding to the high-pressure common rail under that condition. Simultaneously, the detection data from each second metal particle detector is recorded as the benchmark metal particle concentration for the corresponding injector return pipe. The benchmark metal particle concentration difference for each injector is obtained through preset calculation logic. Furthermore, the detection results of each exhaust temperature sensor under that condition are simultaneously recorded to form the benchmark exhaust temperature for each cylinder. All the above data under all operating conditions are categorized and stored, constructing a complete benchmark data system.

[0035] It should be noted that by accurately defining the operating conditions through speed and power signals, the operating conditions of the benchmark data are ensured to be specific. By comprehensively recording various benchmark parameters and calculating the benchmark concentration difference, the benchmark data system is made more complete, providing a comprehensive and accurate reference standard for subsequent fault diagnosis under different operating conditions, and ensuring the reliability of the diagnostic results.

[0036] Preferably, the calculation of the reference metal particle concentration difference for each injector includes: subtracting the reference metal particle concentration of the first metal particle detector on the high-pressure common rail from the reference metal particle concentration of the second metal particle detector on the injector return pipe to obtain the reference metal particle concentration difference for each injector.

[0037] Specifically, when calculating the reference metal particle concentration difference for each injector, the one-to-one correspondence between each injector and the second metal particle detector is first clarified to ensure that each injector can be matched with the reference metal particle concentration data of the corresponding second metal particle detector on its return line. Then, the reference metal particle concentration data of the first metal particle detector on the high-pressure common rail under the same operating condition is retrieved. Following the logic of "corresponding second metal particle detector reference concentration - first metal particle detector reference concentration," the reference metal particle concentration difference for each injector is calculated one by one, and the calculation results are stored in association with the corresponding injector and operating condition.

[0038] It should be noted that this calculation method, by comparing the reference metal particle concentration of the return oil of a single injector with that of the high-pressure common rail, can accurately reflect the metal particle release characteristics of a single injector under healthy conditions. This provides a unique benchmark reference for subsequently judging the wear and other faults of each injector individually, improving the pertinence and accuracy of single injector fault diagnosis.

[0039] Preferably, the real-time acquisition of the detection signals of the sensor group, the diesel engine speed signal, and the power signal, the calculation of the real-time metal particle concentration difference, and the determination of the current operating condition include: acquiring the real-time metal particle concentration of the first metal particle detector, the real-time metal particle concentration of each second metal particle detector, and the real-time exhaust temperature of each exhaust temperature sensor; calculating the real-time metal particle concentration difference corresponding to each injector; and simultaneously acquiring the real-time diesel engine speed signal and the power signal, and determining the current operating condition based on the real-time speed signal and the power signal.

[0040] Specifically, during the real-time data acquisition and processing phase, the system continuously receives real-time metal particle concentration signals from the first metal particle detector within the high-pressure common rail, real-time metal particle concentration signals from the corresponding injector return fuel from each of the second metal particle detectors, and real-time exhaust temperature signals from each corresponding cylinder from each exhaust temperature sensor via the signal transmission channel. Following a preset calculation logic and considering the correspondence between each injector and the second metal particle detector, the system calculates the real-time metal particle concentration difference for each injector. Simultaneously, it collects real-time speed and power signals during diesel engine operation, comparing these two signals with preset operating condition definition standards to accurately determine the current operating condition of the diesel engine.

[0041] It should be noted that the real-time and comprehensive acquisition of various sensor signals and diesel engine operating parameters ensures the timeliness and completeness of the data. The calculation of the real-time metal particle concentration difference can reflect the dynamic changes of the injector in a timely manner, while the determination of the operating conditions based on speed and power ensures that the subsequent fault diagnosis can be matched with the corresponding benchmark data, laying a solid foundation for real-time fault judgment.

[0042] Preferably, the calculation of the real-time metal particle concentration difference corresponding to each injector includes: subtracting the real-time metal particle concentration of the first metal particle detector on the high-pressure common rail from the real-time metal particle concentration of the second metal particle detector on the injector return pipe to obtain the real-time metal particle concentration difference corresponding to the injector.

[0043] Specifically, when calculating the real-time metal particle concentration difference, the real-time detection data of the first metal particle detector under the current operating conditions is first confirmed. Then, the real-time detection data of the corresponding second metal particle detector on the return oil pipe of each injector is extracted one by one. According to the fixed logic of "real-time concentration of the corresponding second metal particle detector - real-time concentration of the first metal particle detector", the calculation is performed on each injector to obtain the real-time metal particle concentration difference of each injector at the current moment, and the data is updated and stored in real time.

[0044] It should be noted that this real-time calculation method is consistent with the calculation logic of the baseline concentration difference, ensuring the consistency and rationality of the data comparison. It can accurately capture the difference between the real-time operating status and health status of a single injector, providing accurate real-time data support for subsequent real-time judgment of whether the injector has wear or other faults.

[0045] Preferably, the fault diagnosis of the injector status includes injector wear diagnosis: if the real-time metal particle concentration difference corresponding to a certain injector exceeds the preset percentage of the reference metal particle concentration difference corresponding to the injector, and the real-time metal particle concentration difference shows a continuous upward trend, then it is determined that the injector has abnormal wear, and an injector abnormal wear warning signal is generated.

[0046] Specifically, during injector wear diagnosis, the system continuously monitors the real-time metal particle concentration difference for each injector and compares it with the baseline metal particle concentration difference for that injector under current operating conditions to determine if the real-time concentration difference exceeds a preset percentage threshold. Simultaneously, by analyzing the trend of this real-time metal particle concentration difference over a period of time, it determines whether it exhibits a continuously increasing trend. When an injector simultaneously meets both the conditions of a real-time concentration difference exceeding a preset percentage and a continuous increase, the system automatically determines that the injector has abnormal wear and immediately generates a corresponding warning signal.

[0047] It should be noted that this diagnostic logic combines the absolute exceedance and trend of the concentration difference, effectively avoiding misjudgments caused by instantaneous fluctuations. It can accurately identify the abnormal wear condition of the injector, realize early warning of wear failure, and facilitate users to take timely repair or replacement measures to prevent wear from aggravating and causing more serious equipment damage.

[0048] Preferably, the fault diagnosis of the injector status includes fuel system abnormality diagnosis: if the real-time metal particle concentration of the first metal particle detector exceeds a preset percentage of its reference metal particle concentration, or the real-time metal particle concentration of a certain second metal particle detector exceeds a preset percentage of its corresponding reference metal particle concentration, and the corresponding real-time metal particle concentration shows a continuous upward trend, then it is determined that there is an abnormality in the fuel system, and a fuel system abnormality warning signal is generated.

[0049] Specifically, during the fuel system anomaly diagnosis process, the system monitors the real-time metal particle concentration of the first metal particle detector and the real-time metal particle concentration of each of the second metal particle detectors. On one hand, the real-time value of the first metal particle concentration is compared with its baseline value under the current operating conditions to determine if it exceeds a preset percentage. On the other hand, the real-time value of each second metal particle concentration is compared with its corresponding baseline value to determine if it exceeds a preset percentage. Simultaneously, trend analysis is performed on the metal particle concentration data exceeding the threshold to confirm whether it shows a continuous upward trend. If the conditions of "the first or any second metal particle concentration exceeding a preset percentage" and "the corresponding concentration continuously increasing" are met, the system determines that there is an anomaly in the fuel system and generates a corresponding warning signal.

[0050] It should be noted that this diagnostic method covers both the overall status monitoring of the fuel system at the high-pressure common rail level and the local status monitoring at the fuel return level of each injector. By making dual judgments on the magnitude and trend of concentration exceedance, it can comprehensively and accurately identify abnormal conditions in the fuel system. Timely warnings help avoid the impact of fuel system failures on the overall operation of the diesel engine.

[0051] Preferably, the fault diagnosis of the injector status includes injector injection abnormality diagnosis: if the real-time exhaust temperature of the exhaust temperature sensor corresponding to a certain cylinder is significantly lower than the reference exhaust temperature corresponding to that cylinder, or significantly lower than the real-time exhaust temperature of the exhaust temperature sensor corresponding to other cylinders, and the real-time metal particle concentration of the first metal particle detector and the real-time metal particle concentration of the second metal particle detector corresponding to that cylinder are both normal, then it is determined that the injector of that cylinder is stuck in the closed position or blocked, and a corresponding warning signal is generated.

[0052] Specifically, when diagnosing injector injection anomalies, the system first extracts the real-time exhaust temperature data from the exhaust temperature sensor corresponding to a specific cylinder. This data is then compared to the reference exhaust temperature of that cylinder under current operating conditions to determine if it is significantly lower. Simultaneously, it is compared horizontally with the real-time exhaust temperatures of all other cylinders to determine if it is significantly lower than the other cylinders. At the same time, the real-time metal particle concentration from the first metal particle detector and the real-time metal particle concentration from the second metal particle detector corresponding to that cylinder are checked to confirm that both data are within the normal range (i.e., not exceeding the preset reasonable range of the corresponding reference value). When the exhaust temperature meets any of the above-mentioned low conditions, and the metal particle concentration is normal, the system determines that the injector in that cylinder is stuck in the closed position or blocked, and generates a targeted warning signal.

[0053] It should be noted that this diagnostic logic, through dual comparison of exhaust temperature longitudinally (with its own baseline) and laterally (with other cylinders), combined with auxiliary verification of metal particle concentration, can eliminate interference caused by abnormal metal particles in the fuel system, accurately locate the fault of injector sticking or blockage, avoid misjudgment that may be caused by a single comparison method, and provide a clear direction for fault diagnosis.

[0054] Preferably, the fault diagnosis of the injector status includes injector drip diagnosis: if the real-time exhaust temperature of the exhaust temperature sensor corresponding to a certain cylinder is significantly higher than the reference exhaust temperature corresponding to that cylinder, or significantly higher than the real-time exhaust temperature of the exhaust temperature sensor corresponding to other cylinders, and the real-time metal particle concentration of the first metal particle detector and the real-time metal particle concentration of the second metal particle detector corresponding to that cylinder are both normal, then it is determined that the injector of that cylinder is stuck in the open position, and a corresponding warning signal is generated.

[0055] Specifically, during the injector drip diagnosis process, the real-time exhaust temperature of a specific cylinder's exhaust temperature sensor is first acquired and compared longitudinally with the baseline exhaust temperature under the current operating conditions of that cylinder to determine if it is significantly higher. Simultaneously, this real-time exhaust temperature is compared laterally with the real-time exhaust temperatures of other cylinders to determine if it is significantly higher than other cylinders. At the same time, the real-time metal particle concentration of the first metal particle detector and the real-time metal particle concentration of the corresponding second metal particle detector for that cylinder are checked to ensure that both data are within acceptable limits. If the exhaust temperature meets any of the above-mentioned conditions and the metal particle concentration is normal, the system determines that the injector in that cylinder is stuck in the open position, resulting in a dripping fault, and generates a corresponding warning signal.

[0056] It should be noted that this diagnostic method, by combining longitudinal and lateral comparisons of exhaust temperature with verification of the absence of abnormalities in metal particle concentration, can effectively distinguish between fuel injector dripping faults and faults caused by abnormal metal particles in the fuel system. This enables accurate diagnosis of dripping faults and timely warnings, which can prevent problems such as fuel waste, excessive exhaust emissions, and overheating damage to components caused by dripping.

[0057] Example 2 like Figure 2 As shown, this embodiment provides a fault diagnosis system for high-pressure common rail electronic fuel injection diesel engine injectors, including the following modules: Sensor group: A first metal particle detector (MPD1) is installed on the high-pressure common rail of the diesel engine; a second metal particle detector (MPD2) is installed on the oil return pipe of each cylinder injector; an exhaust temperature sensor (T1) is installed on each exhaust manifold of the diesel engine and connected to the diesel engine speed and power signals. Data processing and fault diagnosis unit: used to receive real-time signals from all sensors and monitor the status of the injectors and diagnose faults; Human-machine interface: used to display the health status of each injector, alarm information, historical data trend charts, and allows users to set alarm thresholds.

[0058] Specifically, taking a six-cylinder diesel engine as an example, metal particle detectors are installed on the high-pressure common rail and the return oil pipe of each injector, and temperature sensors are installed on each exhaust manifold; all sensor signals are connected to the data processing and fault diagnosis unit to monitor the sensor operating data in real time, and set thresholds for faults such as injector wear, sticking, blockage, and fuel system abnormalities; the human-machine interface is connected to the data processing and fault diagnosis unit to display the operating data of each sensor, and outputs warning information when an abnormality occurs.

[0059] Accordingly, this embodiment also provides a method for diagnosing injector faults in a high-pressure common rail electronic fuel injection diesel engine, including: Baseline value establishment: Run a learning cycle under the healthy condition of the diesel engine, record the baseline metal particle concentration values ​​(MPD1_0, MPD2_0) of the high-pressure common rail and the return pipe of each injector under each operating condition, and calculate the difference in baseline metal particle concentration between the high-pressure common rail and the return pipe of the injectors (ΔMPD_0 =MPD2_0-MPD1_0), as well as the exhaust temperature T1_0 of the diesel engine under each operating condition. Define each operating condition of the diesel engine using the diesel engine speed and power signals.

[0060] Injector wear warning: If the difference in metal particle concentration between the return pipe and the high-pressure common rail of a certain injector exceeds its reference value ΔMPD_0 by a certain percentage (e.g., 130%) and shows a continuous upward trend, it is determined that the injector has abnormal wear and a warning signal is generated.

[0061] Fuel system anomaly warning: If the concentration of metal particles in the high-pressure common rail or the return line of a certain injector exceeds its reference value MPD1_0 or MPD2_0 by a certain percentage (e.g., 130%) and shows a continuous upward trend, it is determined that there are metal particles in the fuel system and a warning signal is generated.

[0062] Injector stuck in the closed position or blocked warning (no injection or low injection volume): If the exhaust temperature T1 of a certain cylinder is significantly lower than T1_0 or other cylinders (because the cylinder does not do power or does low power), and the MPD1 and MPD2 readings are normal, then it is determined that the injector is stuck in the closed position or blocked.

[0063] Injector stuck in open position warning (dripping): If the exhaust temperature T1 of a certain cylinder is significantly higher than T1_0 or other cylinders (because the fuel injection in this cylinder is not atomized, the fuel cannot be fully mixed with the air, the combustion speed is slow and the combustion is incomplete, resulting in high exhaust temperature), and the MPD1 and MPD2 readings are normal, then it is determined that the injector is stuck in the open position.

[0064] In summary, this invention, by monitoring metal particles in the fuel system and exhaust temperature in the exhaust manifold, integrates information such as the concentration and difference of metal particles in the high-pressure common rail and the return pipe of the injector, as well as exhaust temperature, to diagnose injector faults. It can accurately locate the fault in a specific injector and effectively distinguish between fault types such as wear, sticking, blockage, and fuel system abnormalities.

[0065] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

[0066] It should be noted that, for the sake of simplicity, the foregoing method embodiments are described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Secondly, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application. Furthermore, the terms "first," "second," and "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

Claims

1. A high-pressure common-rail electric injection diesel engine injector fault diagnosis system, characterized by, The method comprises the following steps: a sensor group comprising a first metal particle detector, a second metal particle detector and an exhaust temperature sensor, the first metal particle detector is installed on a high-pressure common rail of a diesel engine, the second metal particle detector is multiple and is one-to-one installed on each cylinder injector return pipe of the diesel engine, and the exhaust temperature sensor is multiple and is one-to-one installed on each exhaust manifold of the diesel engine; a data processing and fault diagnosis unit configured to establish baseline metal particle concentration, baseline metal particle concentration difference and baseline exhaust temperature corresponding to each working condition under a healthy state of the diesel engine, receive real-time signals of the sensor group and diesel engine speed and power signals, calculate real-time metal particle concentration difference, determine a current working condition in combination with the diesel engine speed and power signals, and compare real-time signals under the current working condition with corresponding baseline values to perform fault diagnosis on the injector state and generate a corresponding warning signal; a man-machine interaction interface, information displayed on the man-machine interaction interface including injector states, warning information and historical data trend charts.

2. A fault diagnosis method for a high-pressure common-rail electric injection diesel engine injector, based on the injector fault diagnosis system according to claim 1, characterized by, The injector fault diagnosis method comprises the following steps: running for a preset learning period under a healthy state of the diesel engine to establish baseline data corresponding to each working condition; real-time acquisition of detection signals of the sensor group, diesel engine speed signals and power signals, calculation of real-time metal particle concentration difference and determination of a current working condition; based on baseline data corresponding to the current working condition, comparison of real-time data with baseline data, fault diagnosis on the injector state and generation of a corresponding warning signal.

3. The method for diagnosing injector faults in a high-pressure common rail electronic fuel injection diesel engine according to claim 2, characterized in that, The establishment of baseline data corresponding to each working condition comprises defining each working condition through diesel engine speed signals and power signals, recording baseline metal particle concentration of the first metal particle detector under each working condition, recording baseline metal particle concentration of each second metal particle detector, and calculating baseline metal particle concentration difference corresponding to each injector while recording baseline exhaust temperature of each exhaust temperature sensor.

4. The method for diagnosing injector faults in a high-pressure common rail electronic fuel injection diesel engine according to claim 3, characterized in that, The calculation of baseline metal particle concentration difference corresponding to each injector comprises subtracting baseline metal particle concentration of the first metal particle detector on the high-pressure common rail from baseline metal particle concentration of the second metal particle detector on the injector return pipe to obtain baseline metal particle concentration difference corresponding to the injector.

5. The method of claim 2, wherein the method further comprises: The real-time acquisition of detection signals of the sensor group, diesel engine speed signals and power signals, calculation of real-time metal particle concentration difference and determination of a current working condition comprise acquisition of real-time metal particle concentration of the first metal particle detector, real-time metal particle concentration of each second metal particle detector and real-time exhaust temperature of each exhaust temperature sensor, calculation of real-time metal particle concentration difference corresponding to each injector, simultaneous acquisition of real-time diesel engine speed signals and power signals, and determination of a current working condition based on real-time speed signals and power signals.

6. The method of claim 5, wherein the step of determining the fault of the high-pressure common rail diesel engine injector is performed by the steps of: determining whether the voltage of the high-pressure common rail diesel engine injector is lower than the reference voltage; and determining whether the voltage of the high-pressure common rail diesel engine injector is higher than the reference voltage. The calculation of real-time metal particle concentration difference corresponding to each injector comprises subtracting real-time metal particle concentration of the first metal particle detector on the high-pressure common rail from real-time metal particle concentration of the second metal particle detector on the injector return pipe to obtain real-time metal particle concentration difference corresponding to the injector.

7. The method of claim 2, wherein the method further comprises: The fault diagnosis of the state of the fuel injector includes fuel injector wear diagnosis: if the real-time metal particle concentration difference corresponding to a fuel injector exceeds the preset percentage of the reference metal particle concentration difference corresponding to the fuel injector, and the real-time metal particle concentration difference shows a continuous upward trend, it is determined that the fuel injector has abnormal wear, and a fuel injector abnormal wear warning signal is generated.

8. The method of claim 2, wherein the method further comprises: The fault diagnosis of the state of the fuel injector includes fuel injector wear diagnosis: if the real-time metal particle concentration difference corresponding to a fuel injector exceeds the preset percentage of the reference metal particle concentration difference corresponding to the fuel injector, and the real-time metal particle concentration difference shows a continuous upward trend, it is determined that the fuel injector has abnormal wear, and a fuel injector abnormal wear warning signal is generated.

9. The method of claim 2, wherein the method further comprises: The fault diagnosis of the state of the fuel injector includes fuel injector wear diagnosis: if the real-time metal particle concentration difference corresponding to a fuel injector exceeds the preset percentage of the reference metal particle concentration difference corresponding to the fuel injector, and the real-time metal particle concentration difference shows a continuous upward trend, it is determined that the fuel injector has abnormal wear, and a fuel injector abnormal wear warning signal is generated.

10. The method of claim 2, wherein the method further comprises: The fault diagnosis of the state of the fuel injector includes fuel injector wear diagnosis: if the real-time metal particle concentration difference corresponding to a fuel injector exceeds the preset percentage of the reference metal particle concentration difference corresponding to the fuel injector, and the real-time metal particle concentration difference shows a continuous upward trend, it is determined that the fuel injector has abnormal wear, and a fuel injector abnormal wear warning signal is generated. The fault diagnosis of the state of the fuel injector includes fuel injector wear diagnosis: if the real-time metal particle concentration difference corresponding to a fuel injector exceeds the preset percentage of the reference metal particle concentration difference corresponding to the fuel injector, and the real-time metal particle concentration difference shows a continuous upward trend, it is determined that the fuel injector has abnormal wear, and a fuel injector abnormal wear warning signal is generated.

Images