Diesel engine fuel oil system fault monitoring device

Abstract

The invention provides a fault monitoring device for a diesel engine fuel system. The fault monitoring device comprises a fuel tank, a fuel filter, a fuel delivery pump, a high-pressure pump, a fuel rail, a fuel injector, an engine and a fuel return block which are connected. The high-pressure pump is integrated with an oil inlet flow control valve, the fuel oil rail is integrated with an electric control pressure release valve and a pressure control valve, and low-pressure return oil of the electric control pressure release valve, the oil sprayer, the pressure safety valve and the oil inlet flow control valve is collected to the oil return block. An oil inlet flow meter is arranged between the oil tank and the fuel filter, and an oil return flow meter is arranged between the oil return block and the oil tank; and in response to keeping the current signal of the fuel injector unchanged, detecting the current change of the fuel inlet flow meter and the fuel return flow meter, and collecting the current signals of the electric control pressure release valve, the pressure control valve and the fuel inlet flow control valve as well as the rotating speed and exhaust temperature signals of the engine, so as to determine the fuel system performance abnormal parts and the abnormal type. The fault type of the fuel system can be quickly determined, and the fault processing cost is saved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of diesel engine fuel system, and particularly relates to a diesel engine fuel system fault monitoring device. BACKGROUND

[0002] With the progress of high-pressure common rail system technology, more and more diesel engines begin to use high-pressure common rail system. The high-pressure common rail system improves the starting performance and power performance of the diesel engine, but the fuel system is in a high-pressure sealed state for a long time, and higher requirements are put forward for the sealing performance and reliability of the system components. The engine is in a closed environment, and fuel leakage will cause engine starting difficulty, performance reduction, and even serious accidents such as fire. In order to prevent fuel leakage, a double-layer oil pipe protection measure is generally adopted, which has a higher cost and certain requirements for installation process, and the pressure bearing capacity is much lower than the rated working pressure. Therefore, the protection of double-layer oil pipe for high-pressure fuel leakage is limited, which makes it difficult to monitor high-pressure fuel leakage.

[0003] At present, for the fault detection of the fuel system on the engine, the control signals of the system pressure, high-pressure pump, fuel injector, engine speed, exhaust temperature, and fuel consumption data are generally compared. However, due to the high integration of the common rail system, it is difficult to accurately locate the fuel system fault with limited monitoring signals, and special handling methods are required for fault troubleshooting, such as adopting the method of cylinder cut-off to troubleshoot the fuel injector and adopting the method of loosening the oil pipe to troubleshoot the high-pressure pump, which will increase the time, manpower and material cost of solving the fault. SUMMARY

[0004] Therefore, the application aims to provide a diesel engine fuel system fault monitoring device to solve at least one of the above problems.

[0005] To achieve the above purpose, the technical scheme of the application is as follows: The application provides a diesel engine fuel system fault monitoring device, which comprises an oil tank, a fuel filter, a fuel pump, a high-pressure pump, a fuel rail, a fuel injector, an engine and an oil return block connected in sequence. The high-pressure pump is integrated with an oil inlet flow control valve, the fuel rail is integrated with an electric control pressure relief valve and a pressure control valve, and the low-pressure oil return of the electric control pressure relief valve, the fuel injector, the pressure safety valve and the oil inlet flow control valve is collected to the oil return block. An oil inlet flow meter is arranged between the oil tank and the fuel filter, and an oil return flow meter is arranged between the oil return block and the oil tank. In response to keeping the current signal of the fuel injector unchanged, the current changes of the fuel inlet flow meter and the fuel return flow meter are detected, and the current signals of the electric control pressure relief valve, the pressure control valve and the fuel inlet flow control valve, and the engine speed and exhaust temperature signals are collected to determine the abnormal parts and types of the fuel system performance.

[0006] Further, the oil tank, fuel filter, fuel delivery pump and high-pressure pump inlet are connected by a low-pressure oil circuit, and the high-pressure outlet of the high-pressure pump, fuel rail and fuel injector are connected by a high-pressure oil circuit.

[0007] Further, in response to the current of the fuel inlet flow meter, fuel return flow meter and fuel inlet flow control valve increasing, the current of the pressure control valve decreasing, the engine speed and exhaust temperature decreasing, and the electric control pressure relief valve being unchanged, it is determined that the fuel injector nozzle needle valve has high-pressure fuel internal leakage, the fuel injector electromagnetic valve anchor is stuck, and the pressure safety valve is abnormally opened. In response to the current of the fuel inlet flow meter, fuel return flow meter and fuel inlet flow control valve increasing, the current of the pressure control valve decreasing, the engine speed and exhaust temperature increasing, and the electric control pressure relief valve being unchanged, it is determined that the fuel injector control plunger has high-pressure fuel internal leakage and the electric control pressure relief valve is abnormally opened. In response to the current of the fuel inlet flow meter, fuel return flow meter and fuel inlet flow control valve increasing, the current of the pressure control valve decreasing, the engine speed and exhaust temperature decreasing, and the electric control pressure relief valve increasing, it is determined that the pressure safety valve is abnormally opened.

[0008] Further, in response to the current of the fuel inlet flow meter and the fuel inlet flow control valve increasing, the fuel return flow meter being unchanged, the current of the pressure control valve decreasing, the engine speed and exhaust temperature increasing, and the electric control pressure relief valve being unchanged, it is determined that the fuel injector inlet hole is blocked.

[0009] Further, in response to the current of the fuel inlet flow meter and the fuel inlet flow control valve increasing, the current of the fuel return flow meter and the pressure control valve decreasing, the engine speed and exhaust temperature decreasing, and the electric control pressure relief valve being unchanged, it is determined that the high-pressure oil circuit from the high-pressure pump to the fuel injector has external leakage, the high-pressure fuel of the high-pressure pump plunger leaks to the engine oil area, and the low-pressure oil circuit from the fuel inlet flow meter to the low-pressure inlet of the high-pressure pump has external leakage.

[0010] Further, in response to the current of the fuel inlet flow meter, fuel inlet flow control valve, pressure control valve, electric control pressure relief valve, engine speed and exhaust temperature being unchanged, and the fuel return flow meter decreasing, it is determined that the electric control pressure relief valve, fuel injector, pressure safety valve and fuel inlet flow control valve have low-pressure oil circuit and fuel return quick and fuel return flow meter external leakage.

[0011] Further, in response to the current of the oil inlet flow meter and the oil inlet flow control valve being reduced, the current of the oil return flow meter and the pressure control valve being increased, the engine speed and exhaust temperature being reduced, and the electric control pressure relief valve being increased, the injector nozzle needle valve or control plunger sticking is determined.

[0012] Further, in response to the current of the oil inlet flow meter, the oil return flow meter and the oil inlet flow control valve being reduced, the current of the pressure control valve being increased, the engine speed and exhaust temperature being reduced, and the electric control pressure relief valve being increased, the injector nozzle needle valve or control plunger sticking is determined. In response to the current of the oil inlet flow meter, the oil return flow meter and the pressure control valve being reduced, the current of the oil inlet flow control valve being increased, the engine speed and exhaust temperature being reduced, and the electric control pressure relief valve being unchanged, the oil pump damage and oil filter blockage are determined.

[0013] Further, in response to the current of the oil inlet flow meter, the oil return flow meter, the pressure control valve, the electric control pressure relief valve, the engine speed and the exhaust temperature being unchanged, the oil inlet flow control valve being reduced or increased, the oil inlet flow control valve sticking fault is determined.

[0014] Further, in response to the current of the oil inlet flow meter and the oil return flow meter being 0, the air in the main pipeline or the empty oil tank is determined.

[0015] Compared with the prior art, the diesel engine fuel system fault monitoring device has the following beneficial effects: (1) The embodiment can not only monitor the fuel leakage of the low-pressure oil circuit of the fuel system, but also monitor the fuel leakage of the high-pressure oil circuit of the fuel system, thereby reducing the probability of fire accidents caused by fuel leakage, especially high-pressure fuel leakage.

[0016] (2) The embodiment can quickly determine the fault type of the fuel system by dividing the signals of the oil inlet flow meter and the oil return flow meter into eight combinations, thereby saving the fault processing cost. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application. The accompanying drawings should not be construed as an inappropriate limitation on the present application. In the drawings: Figure 1 A structure schematic diagram of the diesel engine fuel system fault monitoring device is shown in the accompanying drawings.

[0018] Explanation of reference signs: 1 - tank; 2 - fuel inlet flow meter; 3 - fuel filter; 4 - fuel pump; 5 - high pressure pump; 6 - fuel rail; 7 - electronically controlled pressure relief valve; 8 - fuel injector; 9 - engine; 10 - pressure safety valve; 11 - fuel inlet flow control valve; 12 - fuel return block; 13 - fuel return flow meter. DETAILED DESCRIPTION

[0019] For the purpose of making the object, technical scheme and advantages of the present application more clear, the present application is further described in detail below with reference to the specific embodiments and the accompanying drawings.

[0020] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be understood as the common meanings understood by those with ordinary skills in the art to which the present application belongs. The terms "first", "second" and similar terms used in the embodiments of the present application do not represent any order, number or importance, but are only used to distinguish different components. The terms "include", "contain" and similar terms mean that the elements or objects before the terms cover the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right" and the like are only used to represent relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships may also change accordingly.

[0021] Referring to Figure 1 As shown in the drawings, the embodiments provide a diesel engine fuel system fault monitoring device, which comprises a tank 1, a fuel filter 3, a fuel pump 4, a high pressure pump 5, a fuel rail 6, a fuel injector 8, an engine 9 and a fuel return block 12 connected together; The high pressure pump 5 is integrated with a fuel inlet flow control valve 11, and the fuel rail 6 is integrated with an electronically controlled pressure relief valve 7 and a pressure control valve. The electronically controlled pressure relief valve 7, the fuel injector 8, the pressure safety valve 10 and the low pressure fuel return of the fuel inlet flow control valve 11 are collected to the fuel return block 12; A fuel inlet flow meter 2 is arranged between the tank 1 and the fuel filter 3, and a fuel return flow meter 13 is arranged between the fuel return block 12 and the tank 1; In response to keeping the current signal of the fuel injector 8 unchanged, the current changes of the fuel inlet flow meter 2 and the fuel return flow meter 13 are detected, and the current signals of the electronically controlled pressure relief valve 7, the pressure control valve and the fuel inlet flow control valve 11, as well as the speed and temperature signals of the engine 9 are collected, so as to determine the abnormal parts and types of the fuel system performance.

[0022] Specifically, in the embodiment, the oil inlet flowmeter 2 is installed between the oil tank 1 and the low-pressure oil circuit of the fuel filter 3, and the oil return flowmeter 13 is installed between the oil return block 12 and the low-pressure oil circuit of the oil tank 1. The low-pressure return oil of the high-pressure pump 5, the fuel rail 6 and the fuel injector 8 is first collected to the oil return block 12 and then returned to the oil tank 1.

[0023] The signals for monitoring the performance of the fuel system and the performance of the engine 9 in the embodiment mainly include the oil inlet flowmeter signal, the oil return flowmeter signal, the oil inlet flow control valve signal, the pressure control valve signal (fuel rail pressure signal), the electronically controlled pressure relief valve signal, the fuel injector solenoid signal, the engine speed and exhaust temperature signals.

[0024] In the embodiment, the oil inlet flowmeter signal and the oil return flowmeter signal are divided into eight groups, the fuel injector solenoid signal is kept unchanged, and the high-pressure pump 5 oil inlet flow control valve signal, the pressure control valve signal (fuel rail pressure signal), the electronically controlled pressure relief valve signal, the engine speed and exhaust temperature signals are combined to determine the faulty components and the fault types of the fuel system.

[0025] In the embodiment, two flow sensors are added to the conventional diesel engine. By comparing the signals of the two flowmeters, the leakage of the fuel system can be monitored. In combination with other sensor signals, the abnormal components and types of the fuel system can be determined. The fault analysis process of the fuel system in the embodiment is as follows: It should be noted that the fuel injector 8 current signal should be kept unchanged during the fault analysis process.

[0026] The flow signals of the oil inlet flowmeter 2 and the oil return flowmeter 13 are divided into eight groups as follows: 1) The flow is simultaneously increased. At this time, the current of the oil inlet flow control valve 11 is monitored to be increased, the current of the pressure control valve is monitored to be decreased, and the electronically controlled pressure relief valve 7 is kept unchanged. The fault conditions at this time are determined as follows: seven kinds of faults, including internal leakage of the fuel injector 8 nozzle needle valve, sticking of the fuel injector 8 solenoid armature at a small lift, sticking of the fuel injector 8 solenoid armature at a large lift, internal leakage of the fuel injector 8 control plunger, internal leakage of the high-pressure oil circuit of the high-pressure pump 5, abnormal opening of the pressure safety valve 10, and abnormal opening of the electronically controlled pressure relief valve 7.

[0027] Further according to the engine speed and the exhaust temperature rise, it can be determined that the fault is the sticking of the fuel injector 8 solenoid armature at a large lift or the internal leakage of the fuel injector 8 control plunger. If the engine speed and the exhaust temperature decrease, it is preferred to check whether the electronically controlled pressure relief valve 7 is abnormally opened.

[0028] 2) The flow of the oil inlet flowmeter 2 is increased, and the flow of the oil return flowmeter 13 is unchanged. At this time, the current of the pressure control valve is monitored to be decreased, the engine speed and the exhaust temperature are monitored to be increased, and the electronically controlled pressure relief valve 7 is kept unchanged. The fault condition at this time is determined as follows: the oil inlet hole of the fuel injector 8 is blocked.

[0029] 3) The flow of the oil inlet flowmeter 2 increases, and the flow of the oil return flowmeter 13 decreases; at this time, the current of the oil inlet flow control valve 11 is monitored to increase, and the electric control pressure relief valve 7 is unchanged; The fault condition at this time is determined as follows: there are three possibilities: the high-pressure oil line from the high-pressure pump 5 to the fuel injector 8 is externally leaked, the high-pressure fuel from the plunger of the high-pressure pump 5 is leaked to the oil area, and the low-pressure oil line from the oil inlet flowmeter 2 to the low-pressure oil inlet of the high-pressure pump 5 is externally leaked. Next, the presence of the phenomena of the rail pressure of the fuel rail 6, the engine speed or the exhaust temperature decreasing can be monitored, and the high-pressure oil line from the high-pressure pump 5 to the fuel injector 8 and the low-pressure oil line from the oil inlet flowmeter 2 to the low-pressure oil inlet of the high-pressure pump 5 can be checked first.

[0030] 4) The flow of the oil inlet flowmeter 2 is unchanged, and the flow of the oil return flowmeter 13 decreases; at this time, the speed and the exhaust temperature of the engine 9 are monitored to be unchanged; The fault condition at this time is determined as follows: the low-pressure oil line of the oil return collection of the electric control pressure relief valve 7, the fuel injector 8, the pressure safety valve 10 and the oil inlet flow control valve 11 to the oil return block 12 and the low-pressure oil line of the oil return quick and the oil return flowmeter 13 is externally leaked.

[0031] 5) The flow of the oil inlet flowmeter 2 decreases, and the flow of the oil return flowmeter 13 increases; at this time, the current of the oil inlet flow control valve 11 is monitored to decrease, the current of the pressure control valve is monitored to increase, the speed and the exhaust temperature of the engine 9 are monitored to decrease, and the electric control pressure relief valve 7 is monitored to increase; The fault condition at this time is determined as follows: the injection hole of the fuel injector 8 is blocked, and the lift of the electromagnetic valve of the fuel injector 8 is small.

[0032] 6) The flow of the oil inlet flowmeter 2 decreases, and the flow of the oil return flowmeter 13 decreases; at this time, the current of the oil inlet flow control valve 11 is monitored to decrease; The oil needle valve or control plunger of the fuel injector 8 is stuck, the fuel pump 4 is damaged, and the fuel filter 3 is blocked. Further, the rail pressure of the fuel rail 6 is increased, and the electric control pressure relief valve 7 is opened, indicating that the needle valve or control plunger of the fuel injector 8 is stuck. The rail pressure of the fuel rail 6 is decreased, and the fuel pump 4 and the fuel filter 3 are detected first.

[0033] 7) The flow of the oil inlet flowmeter 2 is unchanged, and the flow of the oil return flowmeter 13 is unchanged; at this time, the oil inlet flow control valve 11 is monitored to decrease or increase, the pressure control valve, the electric control pressure relief valve 7, the speed and the exhaust temperature of the engine 9 are all unchanged, and it is determined that the oil inlet flow control valve 11 is stuck.

[0034] 8) The flow is 0, indicating that no fuel flows through the oil inlet flowmeter 2 and the oil return flowmeter 13, and it is necessary to detect whether the fuel tank 1 has fuel, or the fuel filter 3 is blocked, or the fuel pump 4 is completely stuck.

[0035] The embodiment can quickly determine the fault type of the fuel system by dividing the signals of the oil inlet and return flow meters into 8 combinations and combining the engine 9 and fuel system monitoring signals, thereby saving the fault processing cost.

[0036] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application.

[0037] The embodiments of the present application are intended to cover all such replacements, modifications and variations of the present application falling within the broadest scope of the appended claims. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principles of the embodiments of the present application should be included in the protection scope of the present application.

Claims

1. A diesel engine fuel system fault monitoring device, characterized in that: This includes the connected fuel tank, fuel filter, fuel pump, high-pressure pump, fuel rail, injectors, engine, and return block; The high-pressure pump integrates an inlet flow control valve, and the fuel rail integrates an electronically controlled pressure relief valve and a pressure control valve. The low-pressure return oil from the electronically controlled pressure relief valve, the injector, the pressure safety valve, and the inlet flow control valve is collected in the return oil block. An inlet flow meter is installed between the fuel tank and the fuel filter, and a return flow meter is installed between the return block and the fuel tank; In response to keeping the current signal of the fuel injector constant, the current changes of the fuel inlet flow meter and the fuel return flow meter are detected, and the current signals of the electronically controlled pressure relief valve, pressure control valve and fuel inlet flow control valve, as well as the engine speed and exhaust temperature signals are collected to determine the abnormal components and abnormality types of the fuel system.

2. The diesel engine fuel system fault monitoring device according to claim 1, characterized in that: in, The fuel tank, fuel filter, fuel pump, and high-pressure pump inlet are connected via a low-pressure oil circuit, while the high-pressure pump outlet, fuel rail, and injector are connected via a high-pressure oil circuit.

3. The diesel engine fuel system fault monitoring device according to claim 1, characterized in that: In response to an increase in the current of the inlet flow meter, the return flow meter, and the inlet flow control valve, the current of the pressure control valve decreases, the engine speed and exhaust temperature decrease, and the electronically controlled pressure relief valve remains unchanged, to determine that there is internal leakage of high-pressure fuel in the injector needle valve, jamming of the injector solenoid valve armature, and abnormal opening of the pressure safety valve. In response to an increase in the current of the inlet flow meter, the return flow meter, and the inlet flow control valve, the current of the pressure control valve decreases, the engine speed and exhaust temperature increase, and the electronically controlled pressure relief valve remains unchanged, to determine internal leakage of high-pressure fuel in the injector control plunger and abnormal opening of the electronically controlled pressure relief valve. In response to an increase in the current of the inlet flow meter, the return flow meter, and the inlet flow control valve, the current of the pressure control valve decreases, the engine speed and exhaust temperature decrease, and the electronically controlled pressure relief valve increases, thereby determining that the pressure safety valve is abnormally opened.

4. The diesel engine fuel system fault monitoring device according to claim 1, characterized in that: In response to an increase in the current of the inlet flow meter and the inlet flow control valve, the return flow meter remains unchanged, the current of the pressure control valve decreases, the engine speed and exhaust temperature increase, and the electronically controlled pressure relief valve remains unchanged, to determine that the injector inlet is blocked.

5. A diesel engine fuel system fault monitoring device according to claim 1, characterized in that: In response to an increase in the current of the inlet flow meter and the inlet flow control valve, a decrease in the current of the return flow meter and the pressure control valve, a decrease in the engine speed and exhaust temperature, and a constant electronic pressure relief valve, it is determined that there is external leakage in the high-pressure oil circuit from the high-pressure pump to the injector, leakage of high-pressure fuel from the high-pressure pump plunger to the oil zone, and external leakage in the low-pressure oil circuit from the inlet flow meter to the low-pressure inlet of the high-pressure pump.

6. A diesel engine fuel system fault monitoring device according to claim 1, characterized in that: In response to the fact that the inlet flow meter, inlet flow control valve, pressure control valve, electronic pressure relief valve, engine speed and exhaust temperature remain unchanged, the return flow meter decreases to determine that the return oil from the electronic pressure relief valve, injector, pressure safety valve and inlet flow control valve is collected in the low-pressure oil circuit of the return block and the low-pressure oil circuit of the return block and return flow meter are leaking externally.

7. A diesel engine fuel system fault monitoring device according to claim 1, characterized in that: In response to a decrease in the current of the inlet flow meter and the inlet flow control valve, an increase in the current of the return flow meter and the pressure control valve, a decrease in the engine speed and exhaust temperature, and an increase in the electronically controlled pressure relief valve, to determine if the injector nozzle is blocked and the injector solenoid valve lift is insufficient.

8. A diesel engine fuel system fault monitoring device according to claim 1, characterized in that: In response to a decrease in the current of the inlet flow meter, the return flow meter, and the inlet flow control valve, the current of the pressure control valve increases, the engine speed and exhaust temperature decrease, and the electronically controlled pressure relief valve increases, to determine that the injector needle valve or control plunger is stuck. In response to a decrease in the current of the inlet flow meter, return flow meter, and pressure control valve, the current of the inlet flow control valve increases, the engine speed and exhaust temperature decrease, and the electronically controlled pressure relief valve remains unchanged, to determine if the oil pump is damaged and the oil filter is clogged.

9. A diesel engine fuel system fault monitoring device according to claim 1, characterized in that: In response to the fact that the inlet flow meter, return flow meter, pressure control valve, electronically controlled pressure relief valve, engine speed and exhaust temperature remain unchanged, the inlet flow control valve decreases or increases to determine that the inlet flow control valve is stuck.

10. A diesel engine fuel system fault monitoring device according to claim 1, characterized in that: In response to the current of the inlet flow meter and the return flow meter being 0, it is determined that there is air in the main pipeline or the oil tank is empty.

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