CN108361138B - Diagnosis and detection method and device for high-pressure common-rail pipe flow limiting valve - Google Patents

Abstract

The invention relates to a diagnosis and detection method and device for a restrictor valve in a high-pressure common rail pipe. Install the exhaust oil collector, the system regularly measures the flow of the electronically controlled fuel injector for calibration and compensation of the diagnostic detection device, and comprehensively judges the restrictor valve by measuring the temperature rise slope when the restrictor valve is working and the closed flow characteristics of the restrictor valve performance. The invention is used to detect the performance of the restrictor valve of the common rail pipe, and uses the temperature rise slope to determine the internal leakage of the restrictor valve or the inflexibility of movement, etc., so as to analyze the fault types of the restrictor valve more comprehensively and ensure the accuracy of the performance detection of the restrictor valve. The performance and reliability of the invention can be directly used in the development, quality control and performance testing of the common rail pipe restrictor valve related products.

Description

Diagnosis and detection method and device for restrictor valve of high pressure common rail pipe

technical field

The present invention relates to a method and a device for diagnosing and detecting a restrictor valve, in particular to a method and device for diagnosing and detecting a restrictor valve in a high-pressure common rail pipe.

Background technique

The application of the electronically controlled high pressure common rail fuel injection system to the engine is a major technological progress, which can directly and effectively improve the performance and exhaust emission level of the engine. As a safety-related power mechanical component, the electronically controlled high-pressure common rail fuel injection system must take various special circumstances into consideration when designing and manufacturing it to ensure the safety and reliability of the product.

The electronically controlled high-pressure common rail fuel injection system forms a basically constant pressure through the pressure storage function of the high-pressure common rail pipe, and distributes it to the engine combustion chamber through the electronically controlled injector. As a result, the high-pressure fuel directly enters the engine cylinder in an uncontrolled state, and the high-pressure common rail pipe is installed with a restrictor valve. When the electronically controlled injector fails to pass through, the flow exceeds the normal working range of the restrictor valve, and the restrictor valve action is cut off. High pressure fuel, thus playing a role in safety protection.

As an important safety component of the high-pressure common rail pipe, the restrictor valve must undergo strict performance testing during the manufacturing process to determine whether the performance of the restrictor valve meets the requirements and ensure that only qualified products can pass. Usually, the detection of the restrictor valve is carried out on a special oil pump test bench. Through the measurement of various set parameters, it is analyzed and judged whether the performance of the restrictor valve meets the requirements, so as to determine whether the performance of the restrictor valve is qualified. The existing method usually uses the electronically controlled injector to adjust the pipeline flow, and analyzes and judges its performance by measuring the closed flow characteristics of the restrictor valve when it is working. Flow measurement has a great influence. Therefore, it is not comprehensive and accurate to analyze the characteristics of the restrictor valve only by measuring the closed flow, and sometimes even wrong conclusions can be obtained. In line with the preset range, it is obvious that the performance of the restrictor valve cannot be accurately judged only by the flow rate, and the correct conclusion cannot be drawn; in addition, due to the high viscosity of the fuel at low temperature, the restrictor valve itself works unstable, and accidental factors may cause The restrictor valve is closed due to its action, which will also affect the accuracy of the performance judgment of the restrictor valve, resulting in misjudgment.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies in the prior art, and to provide a method for diagnosis and detection of a high-pressure common rail restrictor valve, which is dedicated to the diagnosis and detection of a high-pressure common rail restrictor valve, and simulates the performance of an actual restrictor valve. The working state ensures that the test process is consistent with the actual working state, comprehensively and objectively reflects the performance characteristics of the restrictor valve itself, and is easy to implement in the actual production process.

The present invention also provides a high-pressure common rail pipe restrictor valve diagnosis and detection device, which is specially used for the diagnosis and detection of the high-pressure common rail pipe restrictor valve to ensure that the test process is consistent with the actual working state.

According to the technical solution provided by the present invention, the high-pressure common rail restrictor valve diagnosis and detection device is characterized in that: it includes a fuel tank, a high-pressure oil pump, a high-pressure oil pipe, a high-pressure common rail pipe, a pressure sensor, a pressure safety valve, a Electronically controlled high-pressure common rail fuel injection system composed of restrictor valve, pressure relief valve return pipe, system fuel return pipe and electronic control system. , The pressure relief port of the high-pressure common rail pipe is provided with a pressure safety valve and is connected to the fuel tank through the pressure safety valve return pipe. The high-pressure oil outlet of the high-pressure common rail pipe is equipped with a measured flow restrictor valve, and the measured flow restrictor valve is electrically controlled to inject fuel. The flow control and measurement module is connected to the flow control and measurement module through the system oil return pipe; the control signal of the electronically controlled fuel injector is communicated with the electronic control system in real time, and the side of the measured flow limiting valve is installed The temperature measurement module, the signal of the temperature measurement module is connected to the electronic control system, the signal of the flow control and measurement module is connected to the electronic control system, and the fuel output from the flow control and measurement module enters the fuel tank through the system return pipe.

Further, the flow control and measurement module includes a plurality of flow reversing valves, the flow reversing valves are connected with the flow switching and measuring unit to realize the action control of the flow reversing valve, and the flow switching and measuring unit is connected to the electronic control system; The P port of the flow reversing valve is connected to the flow sensor after passing through the exhaust oil collector, the output end of the flow sensor is connected to the multi-channel oil collector, and the multi-channel oil collector is connected to the fuel tank through the system oil return pipe; the flow rate The T port of the reversing valve is connected to the multi-channel oil collector.

Further, the exhaust oil collector is divided into an oil inlet area and an oil outlet area by a middle partition plate, and there is a gap above the middle partition plate, and the liquid in the oil inlet area flows into the oil outlet area through the gap; An oil inlet is arranged at the bottom, and the oil inlet is lower than the actual working liquid level; an oil outlet is arranged on the exhaust oil collector; an outlet is arranged at the highest point above the oil inlet area, and a pressure outlet is installed on the outlet. Vent.

Further, a measured flow restrictor valve is installed at each high pressure oil outlet of the high pressure common rail pipe.

The method for diagnosing and detecting a restrictor valve of a high-pressure common rail pipe is characterized in that the above-mentioned diagnostic detecting device is used for detection, and the method includes the following steps:

(1) Carry out system temperature control, when the temperature of the fuel tank reaches the set value, the temperature control ends;

(2) After reaching the set value temperature, carry out the restrictor valve test, measure the change curve of the surface temperature with time when the restrictor valve is working, judge whether the temperature rise is within the preset range, and conduct the restrictor valve performance according to the temperature curve. initial diagnostic testing;

(3) Measure the closed flow characteristics of the restrictor valve, and judge whether the closed flow is within the specified range in combination with the temperature rise within the preset time when the restrictor valve is working, so as to comprehensively judge the performance of the restrictor valve.

Further, the detection method further includes the step of calibrating the electronically controlled fuel injector: regularly measuring the flow of the electronically controlled fuel injector, and calibrating and compensating the electronically controlled fuel injector through the flow.

The invention simulates the actual working state of the restrictor valve, and the test can truly reflect the working process of the restrictor valve. At the same time, a temperature sensor is installed in the system to measure the temperature rise slope of the restrictor valve and the closed flow characteristics of the restrictor valve. The performance of the restrictor valve is judged, which improves the accuracy of the performance judgment of the restrictor valve. Regularly calibrate the flow of the electronically controlled injectors, calibrate and compensate the electronically controlled injectors used in the system through the flow difference, and correct the consistency differences of the electronically controlled injectors, thereby compensating for the limit caused by the flow deviation of the electronically controlled injectors. Flow valve performance measurement deviation.

Description of drawings

FIG. 1 is a schematic structural diagram of the high-pressure common rail pipe restrictor valve diagnosis and detection device according to the present invention.

FIG. 2 is a schematic diagram of the flow control and measurement module.

FIG. 3 is a schematic diagram of the exhaust oil collector.

Figure 4 is a flow characteristic diagram of the electronically controlled injector.

Figure 5 is a schematic diagram of the comprehensive measurement of the flow temperature when the restrictor valve is closed.

FIG. 6 is a schematic diagram of the temperature rise curve of the restrictor valve.

Figure 7 is a flow chart of the diagnostic test of the restrictor valve.

Description of reference numerals: A-flow control and measurement module, 1-test bench chassis, 2-fuel tank, 3-test bench control computer, 4-high pressure oil pump, 5-electronic control system, 6-high pressure oil pipe, 7-high pressure Common rail pipe, 8-electrically controlled fuel injector, 9-mist eliminator, 10-pressure sensor, 11-pressure safety valve, 12-tested restrictor valve, 13-temperature measuring module, 14-pressure safety valve oil return pipe , 15-system oil return pipe, 31-flow reversing valve, 32-flow switching and measuring unit, 33-exhaust oil collector, 34-flow sensor, 35-multi-channel oil collector, 40-gap, 41-intermediate Separator, 42-exhaust port, 43-pressure exhaust valve.

Detailed ways

The present invention will be further described below in conjunction with the specific drawings.

As shown in FIG. 1 , the high-pressure common rail restrictor valve diagnosis and detection device of the present invention includes a fuel tank 2, a high-pressure oil pump 4, a high-pressure oil pipe 6, a high-pressure common rail pipe 7, a pressure sensor 10, a pressure relief valve 11, a A complete set of electronically controlled high-pressure common rail fuel injection system consisting of measuring restrictor valve 12, pressure relief valve return pipe 14, system fuel return pipe 15 and electronic control system 5, the electronically controlled high-pressure common rail fuel injection system is installed on the test bench chassis 1, the fuel tank 2 is connected to the high-pressure common rail pipe 7 through the high-pressure oil pump 4 and the high-pressure oil pipe 6. The high-pressure common rail pipe 7 is provided with a pressure sensor 10, and the pressure relief port of the high-pressure common rail pipe 7 is provided with a pressure safety valve 11 and passes through the pressure safety valve. The valve return pipe 14 is connected to the fuel tank 2, the high-pressure oil outlet of the high-pressure common rail pipe 7 is installed with the measured restrictor valve 12, and the measured restrictor valve 12 is connected to the flow control and measurement through the electronically controlled fuel injector 8 and the mist eliminator 9 Module A, flow control and measurement module A is connected to the fuel tank 2 through the system return pipe 15 . If the pressure relief valve 11 is depressurized, the fuel enters the fuel tank 2 through the pressure relief valve return pipe 14, and the test bench control computer 3 realizes the control of the entire system and stores the measured parameters in real time. In order to ensure that the diagnostic testing device is in the same working state as the actual electronically controlled high-pressure common rail fuel injection system, each high-pressure oil outlet of the high-pressure common rail pipe 7 is equipped with a flow-limiting valve under test. The present invention only takes a four-cylinder electronically controlled high-pressure common rail fuel injection system as an example to illustrate. The high-pressure common rail pipe 7 of the diagnostic testing device is simultaneously installed with four tested flow limiting valves 12, and the electronic control system 5 is used for closed-loop control of the high-pressure common rail during testing. The fuel pressure in the rail pipe 7 and the control signal of the electronically controlled injector 8 communicate with the electronic control system 5 in real time to realize the opening and closing control of the electronically controlled fuel injector 8. The temperature measurement module 13 is installed on the measured restrictor valve 12 The temperature measurement module 13 is realized by infrared measurement, and the signal of the temperature measurement module 13 is connected to the electronic control system 5 to realize the real-time measurement of the surface temperature of the current limiting valve 12 under test. The flow control and measurement module A realizes pipeline flow switching and flow measurement. The signal of the flow control and measurement module A is connected to the electronic control system 5. The fuel output from the flow control and measurement module A finally enters the fuel tank 2 through the system return pipe 15. The temperature measurement module 13 measures the surface temperature of the measured flow restrictor valve 12 in real time, and comprehensively judges the measured flow restrictor valve by measuring the temperature rise slope of the measured flow restrictor valve 12 when it is in operation and the closed flow characteristics of the measured flow restrictor valve. Whether it meets the requirements, realize the diagnostic detection of the restrictor valve under test.

As shown in FIG. 2, the flow control and measurement module A includes a plurality of flow reversing valves 31, wherein I, II, III and IV represent the corresponding cylinder number positions respectively, and the flow reversing valve 31 is used to switch the flow direction, The flow switching and measuring unit 31 is used to realize the action control of the flow reversing valve 31 and the acquisition of the signal of the flow sensor 34 , and the flow switching and measuring unit 32 is connected to the electronic control system 5 . The fuel from the port P of the flow reversing valve passes through the exhaust oil collector 33 and is connected to the flow sensor 34 to measure the flow. The flow output from the flow sensor 34 enters the multi-channel oil collector 35, and finally enters the fuel through the system oil return pipe 15. Box 2. When the flow is not measured by the flow sensor 34 , the flow from the flow reversing valve T port directly enters the multi-channel oil collector 35 , and after the confluence, the outlet is connected to the system oil return pipe 15 and enters the fuel tank 2 .

As shown in FIG. 2 , the flow reversing valve 31 is in the normally open position by default, that is, the flow of the flow restrictor valve 12 under test is input through the A port of the flow reversing valve 31 and is output to the multi-channel oil collector 35 through the T port. The output flow of the lower measured restrictor valve 12 does not pass through the flow sensor 34, that is, the measurement of the output flow of the measured restrictor valve 12 is not performed; when measuring the flow rate of the measured restrictor valve 12, the position I is taken as an example. , the electronic control system 5 sends out a control signal, and realizes the control of the flow reversing valve at position I through the flow switching and measuring unit 32. At this time, the flow reversing valve acts to close the T port and connect the P port. At this time, from A The flow of the restrictor valve input from the port enters the exhaust oil collector 33 through the P port, and then enters the flow sensor 34 for real-time flow measurement. At the same time, in order to improve the accuracy and stability of the flow measurement, the exhaust oil collector 33 has a pipeline discharge Qi function, the specific structure is shown in Figure 3.

As shown in FIG. 3 , the exhaust oil collector 33 is divided into an oil inlet area and an oil outlet area by a middle partition plate 41 . There is a gap 40 above the middle partition plate 41 , and the liquid in the oil inlet area flows into the oil outlet area through the gap 40 . . In Fig. 3, E is the oil inlet, and F is the oil outlet. The oil inlet E is at the bottom of the exhaust oil collector 33, and the oil inlet E is lower than the liquid level during actual operation to prevent the oil from mixing with the air. Introduce gas. The oil outlet F is located on the upper part of the exhaust oil collector 33, which can shorten the time for the liquid stored in the oil outlet area to continue to flow out of the oil outlet F to form a flow when the oil inlet area does not receive oil. There is an exhaust port 42 at the highest point above the oil inlet area, and a pressure exhaust valve 43 is installed on the exhaust port 42. After the fuel flows into the oil inlet area through the pressure exhaust valve 43, due to the buoyancy of the air, the gas gradually rises to the exhaust port. At the highest point of the gas oil collector 33, when the pressure reaches the limit value, the pressure exhaust valve 43 is automatically opened, the gas is discharged through the exhaust port 42, and when the gas pressure is lower than the limit value, the pressure exhaust valve 43 is automatically closed, thereby Ensure that the gas in the exhaust oil collector 33 is discharged in time, reduce the risk of gas mixing into the oil, and improve the stability and accuracy of flow measurement.

Figure 4 shows the flow characteristic table of the electronically controlled injector 8. For a mass-produced electronically controlled injector with good performance, the relationship between injection pressure, driving time and flow rate is shown in the curve in Figure 4, namely, At the same pressure, the longer the driving time, the larger the flow rate, and the higher the injection pressure at the same driving time, the larger the flow rate.

For the actual electronically controlled injector, due to its complex electromagnetic, hydraulic and mechanical mechanisms, the basic performance will age and drift as the working time goes on. In order to ensure the consistency of the flow detection of the restrictor valve and stability, the performance of the electronically controlled injector as a throttling function in the diagnostic testing device should be consistent. Therefore, in order to ensure the accuracy and reliability of the performance test of the restrictor valve, the electronically controlled fuel injector should be calibrated regularly. When the diagnostic detection device is stabilized, the flow switching and measurement unit 32 shown in FIG. 2 is used to test each electronically controlled fuel injector respectively. 8 The flow rate under the conditions of the set pressure and driving time, and is corrected according to the difference in flow rate. Here, only the injection pressure P1 and the driving time t are used as examples for analysis. For an electronically controlled injector with ideal characteristics, the flow rate at this time is q, which is shown at point A in Figure 4; when the electronically controlled injector ages and changes, if the pressure P1 is set, the actual test flow at the driving time t is q', here it is assumed that q'>q, that is, in Figure 4 As shown at point A', the driving time corresponding to the flow rate q' is interpolated on the injection pressure P1 characteristic curve as t'. As shown at point B in Figure 4, the time difference Δt between points A and B is calculated.

Δt=t'-t(1);

The time difference Δt is the calibration compensation value of the electronically controlled injector. Since the actual flow characteristic q' of the electronically controlled injector is higher than the theoretical flow q, the electronic control system 5 takes the time after deducting Δt as the actual drive when driving. Time, thereby correcting the increased flow of the electronically controlled injector to ensure that the actual flow is consistent with the theoretical characteristics. When the actual flow of the electronically controlled injector is less than the theoretical characteristic flow, that is, q'<q can be analyzed in the same way, the only difference is that the actual driving time at this time should be increased by Δt. This method is used to calibrate the electronically controlled injector regularly, and update the calibration compensation value Δt of the corresponding injector after the calibration test to ensure the same performance of the electronically controlled injector used for the restrictor valve test, and to ensure the accuracy of the restrictor valve performance test. , to avoid differences in restrictor valve testing due to differences in flow performance of electronically controlled injectors.

As shown in Figure 5, it is a schematic diagram of the comprehensive measurement of the closed flow temperature of the restrictor valve. After the temperature control of the diagnostic detection device meets the test conditions, it is the starting point of the test, that is, the test time is 0:00, and then it runs to time t ₁ according to the preset working conditions. , and record the temperature of the restrictor valve in real time from 0 to _t1 . Assuming that the temperature of the restrictor valve at time _t1 is T1, corresponding to point P, for _a properly functioning restrictor valve, the temperature rise curve during the period from 0 to _t1 It should be within the specified range, that is, the temperature change must conform to a certain law, which is determined by testing and calibrating the normal flow restrictor valve, and the specific temperature rise curve limit is shown in Figure 6; The throttle flow of the electronically controlled injector is gradually increased according to the set interval at the time _t2 , and the temperature of the restrictor valve at time _t2 is recorded as _T2 , which corresponds to the Q point. As the flow through the restrictor valve gradually increases Increase, if the restrictor valve action is closed at the time of _t3 , the temperature of the restrictor valve at this time is T3, corresponding to point _R , the temperature rise slope K is recorded as follows:

Then at the time t ₃ of the restrictor valve test process, in addition to recording the closed flow rate q _close of the restrictor valve as an important detection indicator, that is, the closed flow rate q _close must be within the specified range, and also analyze whether the temperature rise slope K is within the specified range. When the internal leakage of the flow valve or the movement is inflexible, it can be judged by the abnormal temperature. Therefore, the temperature rise slope K can be used to judge the internal leakage or inflexible movement of the restrictor valve, and this kind of fault can only be closed by the restrictor valve. The analysis of q _close cannot be effectively judged. Therefore, by measuring the temperature rise slope of the restrictor valve and the closed flow characteristics of the restrictor valve to comprehensively judge the performance of the restrictor valve, various fault types of the restrictor valve can be analyzed more comprehensively, and the detection of the restrictor valve can be ensured. Accuracy and reliability.

Note the duration from the start of the closed flow test to the closing of the restrictor valve as Δt ₂ , as follows:

Δt ₂ =t ₃ -t ₂ (3);

If in the testing process from time t ₂ , the restrictor valve is still not closed after t _lmt , that is, the restrictor valve is still not closed when the system reaches the specified flow rate, then it is judged that the restrictor valve is faulty, where t _lmt is determined by calibration The test time parameter of the restrictor valve, the parameter t _lmt >Δt ₂ . The times t ₁ , t ₂ and t ₃ are parameters determined by calibration according to the actual situation, and the temperatures T ₁ , T ₂ and T ₃ are obtained by actual measurement.

Figure 6 is a schematic diagram of the temperature rise curve of the restrictor valve, the abscissa in the figure is the test time, and the ordinate is the surface temperature value of the restrictor valve, that is, a restrictor valve with normal performance, as the flow passes through the surface of the restrictor valve The temperature also rises accordingly. If for some reason, the restrictor valve is stuck and does not work, because there is no flow, the temperature is basically unchanged or rises very slowly. At this time, the temperature value at the corresponding moment is lower than the lower limit value. ; If for some reason, such as the internal leakage of the restrictor valve, the temperature rises sharply, and the temperature value at the corresponding time is higher than the upper limit value. Therefore, through the relationship between the temperature value on the surface of the restrictor valve at the corresponding time and the upper limit and lower limit value, It can qualitatively judge whether the performance of the restrictor valve is basically normal, and make a preliminary judgment for the subsequent further comprehensive analysis of the temperature rise slope and the closed flow characteristics of the restrictor valve. Statistical analysis of valve test to determine.

As shown in Figure 7, the diagnostic test flow of the restrictor valve is shown:

Step S10: initialize the system, complete the self-diagnosis function of the system and the sensor;

Step S20: input test information, input the relevant information of the restrictor valve under test, such as product model, serial number, tester, etc.;

Step S30: the test-bed control computer communicates, that is, the electronic control system establishes communication with the test-bed control computer, and waits for the input of the test-bed control computer operation instructions;

Step S40: Judging on receipt of the test instruction, that is, judging whether the test instruction sent by the test bench control computer is correctly received, and if the instruction is not received, return to step S30 to continue to wait; if the test instruction sent by the test bench control computer is correctly received, Enter step S50;

Step S50: measuring the temperature of the fuel tank, that is, collecting the temperature value of the fuel tank of the test bench;

Step S70: Determine whether the temperature of the fuel tank meets the set value. If it meets the set value, the program goes to the next step. Otherwise, if the temperature of the fuel tank does not meet the set value, then enter the temperature control step S60, that is, cooling is performed when the temperature is high. If the temperature is low, run the electronically controlled high-pressure common rail fuel injection system under heavy load to increase the fuel temperature, and then perform temperature measurement and judgment again until the fuel tank temperature is within the set value range;

Step S80: Determine whether it is necessary to calibrate the electronically controlled injector. Since the calibration time of the electronically controlled injector is relatively long, the calibration rules of the electronically controlled injector can be set according to the actual situation, such as a specified working time or a specified number of tests. Therefore, in step S80, it is judged whether the calibration conditions of the electronically controlled injector are met. If so, it will go to step S85 to calibrate the flow of the electronically controlled injector. The specific calibration process is based on the flow of the electronically controlled injector described in FIG. 4 . characteristic table execution;

Step S90 : correcting the flow rate of the electronically controlled fuel injector according to the result of the flow rate calibration. If it is determined in step S80 that the flow calibration of the electronically controlled injector is not required, then step S100 is entered to measure the temperature _of the restrictor valve, that is, as shown in FIG. Step S110 is the temperature curve judgment. This step is mainly to judge according to the temperature rise curve shown in FIG. 6 to judge whether the temperature rise is within the preset range. end; if the temperature rise is within the specified range, then enter step S120 to measure the flow rate of the restrictor valve closed, that is, the system operates according to the set operating conditions until time _t2 and starts to gradually increase the throttle flow rate of the electronically controlled injector at specified intervals , if the restrictor valve action is closed at time _t3 , and the K value is calculated according to formula (2), and it is judged whether the closed flow is within the specified range, step S130 generates a corresponding test report, including test information data, whether the test is qualified, etc. , after the test report is generated, the current limiting valve test ends, the corresponding test results are stored, and the next test command is awaited.

The specific embodiments described above, including the enumerated flow charts, may have various modifications and changes within the scope covered by the content of the present invention and the claims. Therefore, the described embodiments do not constitute the protection of the claims of the present invention. scope limit.

Claims (5)

1. A method for diagnosing and detecting a high-pressure common rail restrictor valve, using a diagnostic and detecting device for a high-pressure common rail restrictor valve; the high-pressure common rail restrictor valve diagnostic and detecting device includes a fuel tank (2 ), high-pressure oil pump (4), high-pressure oil pipe (6), high-pressure common rail pipe (7), pressure sensor (10), pressure relief valve (11), measured flow restrictor valve (12), pressure relief valve return pipe ( 14) The electronically controlled high pressure common rail fuel injection system composed of the system oil return pipe (15) and the electronic control system (5), the fuel tank (2) is connected to the high pressure common rail pipe ( 7), a pressure sensor (10) is set on the high-pressure common rail pipe (7), a pressure relief valve (11) is set at the pressure relief port of the high-pressure common rail pipe (7), and the oil return pipe (14) is connected to the fuel tank (14) through the pressure relief valve. 2) Connection, the high-pressure oil outlet of the high-pressure common rail pipe (7) is installed with the tested restrictor valve (12), and the tested restrictor valve (12) is connected through the electronically controlled fuel injector (8) and the mist eliminator (9). The flow control and measurement module (A) is connected to the fuel tank (2) through the system oil return pipe (15); the control signal of the electronically controlled fuel injector (8) is connected to the electronic control system (5). ) real-time communication, a temperature measurement module (13) is installed on the side of the measured restrictor valve (12), the signal of the temperature measurement module (13) is connected to the electronic control system (5), and the signal of the flow control and measurement module (A) is connected to the electronic control system (5). The control system (5) is connected, and the fuel output from the flow control and measurement module (A) enters the fuel tank (2) through the system return pipe (15); It is characterized in that it includes the following steps: 1) Carry out system temperature control, when the temperature of the fuel tank reaches the set value, the temperature control ends; 2) After reaching the set value temperature, carry out the restrictor valve test, measure the change curve of the surface temperature with time when the restrictor valve is working, judge whether the temperature rise is within the preset range, and carry out the performance evaluation of the restrictor valve according to the temperature curve. preliminary diagnostic tests; 3) Measure the closing flow characteristics of the restrictor valve, and combine the temperature rise within the preset time when the restrictor valve is working to judge whether the closed flow is within the specified range, so as to comprehensively judge the performance of the restrictor valve. 2. The method for diagnosing and detecting a high-pressure common rail flow restrictor valve as claimed in claim 1, wherein the detecting method further comprises the step of calibrating the electronically controlled fuel injector: regularly measure the flow of the electronically controlled fuel injector, and pass the The flow is calibrated and compensated for the electronically controlled injector. 3. The method for diagnosing and detecting a high-pressure common rail pipe restrictor valve as claimed in claim 1, wherein: The flow control and measurement module (A) includes a plurality of flow reversing valves (31), and the flow reversing valves (31) are connected with the flow switching and measuring unit (32) to realize the action control of the flow reversing valve (31). , the flow switching and measuring unit (32) is connected to the electronic control system (5); the P port of the flow reversing valve (31) is connected to the flow sensor (34) through the exhaust oil collector (33), and the flow sensor The output end of (34) is connected to the multi-channel oil collector (35), and the multi-channel oil collector (35) is connected to the fuel tank (2) through the system oil return pipe (15); the T of the flow reversing valve (31) The port is connected to the multi-way oil collector (35). 4. The method for diagnosing and detecting a high-pressure common rail pipe restrictor valve as claimed in claim 3, wherein: The exhaust oil collector (33) is divided into an oil inlet area and an oil outlet area by a middle partition plate (41), a gap (40) is arranged above the middle partition plate (41), and the liquid in the oil inlet area passes through the gap (40). Flow into the oil outlet area; set an oil inlet (E) at the bottom of the exhaust oil collector (33), and the oil inlet (E) is lower than the actual working liquid level; set an outlet at the exhaust oil collector (33) Oil port (F); an exhaust port (42) is provided at the highest point above the oil inlet area, and a pressure exhaust valve (43) is installed on the exhaust port (42). 5. The method for diagnosing and detecting a high-pressure common rail pipe restrictor valve as claimed in claim 1, wherein: A measured restrictor valve is installed at each high-pressure oil outlet of the high-pressure common rail pipe (7).

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