A new diesel engine low-pressure oil circuit measurement method
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANHUI QUANCHAI ENGINE
- Filing Date
- 2026-03-09
- Publication Date
- 2026-05-29
Smart Images
Figure CN122108613A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of vehicle technology, specifically to a new method for measuring the low-pressure oil circuit of a diesel engine. Background Technology
[0002] In the research, development, production, and after-sales maintenance of diesel engines, the compliance of the low-pressure oil circuit, as the fuel supply path from the fuel tank to the high-pressure oil pump inlet, is of critical importance. Parameters such as pressure, flow rate, sealing performance, and the presence of abnormal resistance in the low-pressure oil circuit directly affect the normal operation of the high-pressure oil pump, thereby impacting engine performance, emissions, and reliability. Currently, the industry generally uses decentralized and non-systematic measurement methods to inspect the low-pressure oil circuit, such as checking the oil pressure separately or visually inspecting the pipeline.
[0003] In light of the above, it should be noted that existing technologies lack a comprehensive measurement method that integrates cloud monitoring and multi-module linkage. This method cannot achieve simultaneous acquisition and quantitative comparison of key parameters along the entire low-pressure oil circuit path, nor can it accurately pinpoint the source of segmented resistance. Furthermore, its adaptability is insufficient, failing to meet the measurement needs of different types of oil circuit systems and various scenarios. This deficiency leads to low efficiency in troubleshooting related issues, making rapid consistency verification on vehicle assembly lines or repair shops difficult. It also makes it impossible to predict system operational risks in advance, potentially causing engine performance degradation, component damage, and other hidden dangers, bringing numerous inconveniences to the research, development, production, and after-sales maintenance of diesel engines.
[0004] To address the aforementioned technical shortcomings, a solution is proposed. Summary of the Invention
[0005] The purpose of this invention is to provide a new method for measuring the low-pressure oil circuit of a diesel engine to solve the problems mentioned above.
[0006] To achieve the above objectives, the present invention provides the following technical solution: a new method for measuring the low-pressure oil circuit of a diesel engine, comprising the following steps:
[0007] S1. Determine the measurement range based on the target, and build a test system accordingly. Based on the cloud database, construct a measurement monitoring platform in conjunction with the test system to obtain key parameters A of the entire low-pressure oil circuit, position parameters B of the four measuring points, and performance parameters C of the test equipment, and send them to the total resistance risk assessment module, segmented resistance difference analysis module, and curve analysis module.
[0008] S2, the total resistance risk assessment module collects the basic data of total resistance measurement and analyzes and generates the remaining energy feedback signal;
[0009] S3, the segmented resistance difference analysis module collects the basic data of segmented resistance measurement and generates difference feedback signals through analysis of the basic data;
[0010] S4, the curve analysis module jointly constructs and measures the flow-resistance characteristic curve based on relevant data from bench tests;
[0011] S5, the joint judgment module processes the analysis results in a coordinated manner to generate a reasonable measurement method.
[0012] Furthermore, the stated measurement objective for the low-pressure fuel circuit of the diesel engine is to assess the flow resistance from the fuel tank to the high-pressure fuel pump inlet, ensuring that fuel is delivered in sufficient quantity with sufficiently low flow resistance and sufficiently stable pressure. Based on this, the measurement range is determined to cover the entire path from the fuel tank to the high-pressure fuel pump inlet. Four key measurement points are selected: after the fuel pump outlet, before the fuel filter, after the fuel filter, and at the high-pressure fuel pump inlet. A test system is built, including a precision pressure gauge or pressure sensor, a flow meter, a vacuum gauge, and a data acquisition system. Based on the measurement range, the key parameters A of the entire low-pressure fuel circuit, the position parameters B of the four measurement points, and the performance parameters C of the test equipment are obtained.
[0013] Furthermore, based on the position parameters of the high-pressure oil pump inlet of the four measuring points B, the precise installation coordinates of the vacuum gauge or pressure sensor are determined to ensure that the energy state data of the fuel delivery endpoint is collected. Combined with the performance requirements of the test equipment in the performance parameters C, the pressure value P is collected in real time under different engine operating conditions.
[0014] By directly extracting the upper limit standard of high-pressure oil pump inlet vacuum degree and the lower limit standard of high-pressure oil pump inlet vacuum degree corresponding to the target oil suction system from the key parameter A of the entire low-pressure oil circuit, the upper limit standard of vacuum degree is marked as the vacuum degree threshold of the oil suction system. .
[0015] Furthermore, after obtaining the pressure value P and the vacuum threshold of the oil suction system... Minimum pressure value of push-type system design Subsequently, based on the fact that the inlet pressure of the high-pressure oil pump directly reflects the energy state of the fuel delivered to the destination, the following formula is used to obtain... and Retrieve the preset vacuum difference threshold and standard pressure threshold and compare them with... and Comparison: When When the vacuum difference exceeds the threshold limit, a Level 1 anomaly record is generated; when When the pressure exceeds the standard limit value, a secondary abnormality record is generated; when a primary or secondary abnormality record exists, a residual energy feedback signal is generated.
[0016] Furthermore, based on the specific location parameters of the four measuring points in position parameter B, pressure sensors meeting the performance requirements of performance parameter C of the testing equipment were installed at the following locations: after the fuel pump outlet, before the fuel filter, after the fuel filter, and at the high-pressure fuel pump inlet. Under stable engine operating conditions, real-time pressure data values at each measuring point were synchronously collected and sequentially marked as follows: , , , .
[0017] Furthermore, the vacuum degree judgment threshold corresponding to the fuel tank-fuel pump section is extracted from the key parameter A of the entire low-pressure oil circuit and marked as the vacuum degree threshold of the fuel tank-fuel pump section. Based on the relevant design data of the corresponding components recorded within the measurement and monitoring platform, the upper limit of the differential pressure for normal operation of the new fuel filter is obtained and marked as the design value of the differential pressure for the new fuel filter. The maximum allowable differential pressure of the old fuel filter is marked as the maximum differential pressure limit for the old fuel filter. The maximum permissible pressure difference of the pipeline section other than the filter section is marked as the maximum permissible pressure difference of the non-filter section. Based on the formula analysis, the absolute value of the pressure difference from the oil tank to the front of the filter is obtained. The absolute value of the pressure difference between the filter and the high-pressure oil pump inlet. The absolute value of the pressure difference between the fuel filter and the high-pressure fuel pump inlet. .
[0018] Furthermore, based on the positioning logic of the fuel tank-fuel pump section as the key resistance investigation section among the four measuring points, a vacuum gauge meeting the performance parameter C requirements of the testing equipment is installed at the fuel pump inlet. Under stable engine operating conditions, the measured vacuum degree of the fuel tank-fuel pump section is collected in real time. The actual vacuum degree of the fuel tank-fuel pump section was measured. Compare the results with the segmented pressure difference results: when > When, a level three exception record is generated; when > or > When, a level 4 exception record is generated; when ≤ , ≤ , ≤ And the new filter ≤ Old filter ≤ If necessary, maintain the status quo and only record data; summarize the results of the joint comparison and generate a difference feedback signal.
[0019] Furthermore, in bench tests, an adjustable flow device was used to simulate the engine's fuel demand under different loads. Based on the engine's fuel flow demand range (A), a key parameter of the entire low-pressure fuel circuit, the adjustable flow device, meeting the performance parameter (C) requirements of the test equipment, was used to set flow values in gradients. The flow data corresponding to each gradient was marked as the simulated fuel flow value Q, and the starting pressure of the fuel circuit was collected simultaneously. and pressure at measuring point 4 Through formula ,in, This is expressed as the total pressure drop of the low-pressure oil circuit at the corresponding flow rate.
[0020] Furthermore, using the simulated fuel flow rate Q as the horizontal axis and the total pressure drop in the low-pressure oil circuit at the corresponding flow rate as the vertical axis,... Using the vertical axis as the ordinate, the flow-resistance characteristic curve is obtained by substituting the measured data into the fitting model. The curve equation can be expressed as follows: = k×Q + b, where k represents the slope of the curve, which represents the rate of increase of resistance with flow rate, and b represents the intercept, thus obtaining the flow-resistance characteristic curve.
[0021] The beneficial effects of this invention are:
[0022] 1. This invention achieves systematic and quantitative measurement of the entire low-pressure oil circuit by constructing an integrated testing system and a cloud-based measurement and monitoring platform, linking four modules: total resistance risk assessment, segmented resistance difference analysis, curve analysis, and joint judgment. With the precise positioning of four key measuring points and the comparison of standardized parameters, it can not only quickly collect pressure, vacuum, and differential pressure data under different operating conditions, but also generate graded anomaly records and feedback signals through quantitative calculations, accurately locating problems such as blockage in the fuel tank-fuel pump section, excessive pipeline resistance, and insufficient filter flow capacity, completely solving the pain points of low efficiency and inability to accurately trace faults in traditional decentralized measurement methods.
[0023] 2. This invention adapts to both suction and push-type low-pressure oil circuit systems, taking into account the needs of multiple scenarios such as bench testing, after-sales fault diagnosis, component verification, and oil adaptability assessment. By constructing the flow-resistance characteristic curve and evaluating the design margin, it can predict the operational risks of the system under extreme conditions in advance, effectively avoiding problems such as insufficient fuel supply, cavitation damage, and response lag. This ensures engine performance, emissions, and reliability while reducing fuel pump energy consumption and subsequent maintenance costs, achieving a balance between the practicality and forward-looking nature of the measurement method. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a flowchart of the method of the present invention;
[0026] Figure 2 This is a flowchart of the system of the present invention. Detailed Implementation
[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0028] Example 1: Please refer to Figure 1 - Figure 2 As shown, this embodiment is a new method for measuring the low-pressure oil circuit of a diesel engine, including the following steps:
[0029] S1. Determine the measurement range based on the target and build a test system accordingly; the measurement target of the low-pressure oil circuit of the diesel engine is to evaluate the flow resistance from the fuel tank to the high-pressure oil pump inlet, and ensure that the fuel is delivered in sufficient quantity with sufficiently low flow resistance and sufficiently stable pressure. Based on this, the measurement range is determined to cover the entire path from the fuel tank to the high-pressure oil pump inlet. Four key measurement points are selected: after the fuel pump outlet, before the fuel filter, after the fuel filter, and at the high-pressure oil pump inlet. A test system including a precision pressure gauge or pressure sensor, flow meter, vacuum gauge, and data acquisition system is built.
[0030] A measurement and monitoring platform is built based on a cloud database and a testing system. The measurement and testing platform has communication connections for a total resistance risk assessment module, a segmented resistance difference analysis module, a curve analysis module, and a joint judgment module.
[0031] The measurement and monitoring platform acquires key parameters of the entire low-pressure oil circuit, location parameters of four measuring points, and performance parameters of the testing equipment based on the measurement range. These parameters are labeled A, B, and C respectively. Among them, key parameters A of the entire low-pressure oil circuit represent parameters related to the core requirements for fuel delivery that the low-pressure oil circuit must meet, including flow resistance threshold, pressure stability range, and fuel delivery standard; location parameters B of the four measuring points represent the coordinates and functional positioning of the measuring points to ensure accurate acquisition of key location data; and performance parameters C of the testing equipment represent the basic performance indicators of the testing equipment, such as the range of a precision pressure gauge from -1 bar to 5 bar.
[0032] It should be noted that the three sets of data collected are used to clarify the range and key measuring points corresponding to the measurement target. Only by matching them with equipment that meets the accuracy requirements can a reliable foundation be provided for subsequent measurements. Based on the three sets of data collected and the core task of fuel transportation in the low-pressure oil circuit, key locations that have a direct impact on flow resistance and pressure are selected as measuring points. Combined with the measurement parameter requirements, suitable test equipment is selected to form a test system that covers the critical path, has accurate measuring points, and meets equipment standards, thus ensuring the validity of the measurement data.
[0033] S2, the total resistance risk assessment module collects the basic data of total resistance measurement and analyzes and generates the remaining energy feedback signal; based on the position parameters of the high-pressure oil pump inlet of measuring point 4 in the position parameters B of the four measuring points, it determines the precise installation coordinates of the vacuum gauge or pressure sensor to ensure that the energy state data of the fuel delivery endpoint is collected. Combined with the performance requirements of the test equipment in the performance parameters C, such as the range of -1~5 bar and the high-precision pressure sensor, it avoids data distortion caused by insufficient range or accuracy defects of the equipment; finally, under different engine operating conditions, the pressure value P is collected in real time by the device. The pressure value P represents the actual pressure state data of the fuel reaching the high-pressure oil pump inlet when measuring point 4 of the high-pressure oil pump reaches the high-pressure oil pump inlet, collected by the test equipment under different operating conditions of engine idling, medium speed and full load.
[0034] By directly extracting the upper limit standard of high-pressure oil pump inlet vacuum degree and the lower limit standard of high-pressure oil pump inlet vacuum degree corresponding to the target oil suction system from the key parameter A of the entire low-pressure oil circuit, the upper limit standard of vacuum degree is marked as the vacuum degree threshold of the oil suction system. Vacuum threshold of oil suction system This refers to the maximum permissible vacuum threshold at the inlet of the high-pressure oil pump in a suction-type low-pressure oil circuit system. Exceeding this value indicates excessive flow resistance. The minimum pressure standard at the inlet of the high-pressure oil pump is marked as the minimum design pressure value for a push-type system. Minimum pressure value of push-type system design This refers to the minimum positive pressure value required for the high-pressure oil pump inlet to maintain normal operation in a push-type low-pressure oil circuit system. If the pressure is lower than this value, it indicates that the resistance is too high or the oil supply pump capacity is insufficient.
[0035] After obtaining the pressure value P and the vacuum threshold of the oil suction system Minimum pressure value of push-type system design Subsequently, based on the fact that the inlet pressure of the high-pressure oil pump directly reflects the energy state of the fuel delivered to the destination, the formula is used... , ,in, This represents the difference between the actual vacuum level of the oil suction system and the preset vacuum threshold. This represents the difference between the minimum design pressure and the actual pressure of the push-type system. The preset vacuum threshold is obtained from historical data or factory standard data and pre-stored in the measurement and monitoring platform. Simultaneously, the preset vacuum difference threshold limit and the standard pressure limit are retrieved sequentially. and Comparison:
[0036] when When the vacuum difference exceeds the threshold limit, it indicates that the flow resistance exceeds the standard, and a first-level abnormal record is generated.
[0037] when If the pressure exceeds the standard limit value, it is determined that the resistance is too high or the oil supply pump capacity is insufficient, and a level 2 abnormal record is generated.
[0038] when < Vacuum degree difference threshold limit value, or If the pressure is less than the standard pressure limit, then maintain the status quo and only record the data;
[0039] When a Level 1 or Level 2 anomaly record is present, a residual energy feedback signal is generated, and the signal strength is similar to... or The absolute value of the value is positively correlated, which intuitively reflects the impact of total resistance on the remaining fuel energy.
[0040] S3, the segmented resistance difference analysis module, collects the basic data of segmented resistance measurement and generates difference feedback signals through analysis of the basic data. Based on the specific location parameters of the four measuring points in position parameter B, pressure sensors that meet the performance requirements of the test equipment's performance parameter C, such as high-precision, range-adaptive sensors, are installed at the fuel pump outlet, fuel filter in front, fuel filter outlet, and high-pressure fuel pump inlet. Under stable engine operating conditions, real-time pressure data values at each measuring point are synchronously collected and sequentially marked as follows: , , , Real-time pressure data values This represents the measured pressure value after the fuel pump outlet at the corresponding measuring point 1. This represents the measured pressure value before the fuel filter at measurement point 2. This represents the measured pressure value after the fuel filter at the corresponding measuring point 3, and... This represents the measured pressure value at the inlet of the high-pressure oil pump at the corresponding measuring point 4. The unit is bar, and it is the basic measured data for calculating the segmented pressure difference.
[0041] The vacuum threshold corresponding to the fuel tank-fuel pump section is extracted from the key parameter A of the entire low-pressure oil circuit and marked as the fuel tank-fuel pump section vacuum threshold. Vacuum threshold of fuel tank-fuel pump section This represents the critical vacuum value used to determine whether the fuel tank-fuel pump section is clogged, and it serves as the standard basis for judging the resistance of this section. Based on the relevant design data of the corresponding components recorded within the measurement and monitoring platform, the upper limit of the differential pressure for normal operation of the new fuel filter is obtained and marked as the design value of the differential pressure for the new fuel filter. The maximum allowable differential pressure of the old fuel filter is marked as the maximum differential pressure limit for the old fuel filter. The maximum permissible pressure difference of the pipeline section other than the filter section is marked as the maximum permissible pressure difference of the non-filter section. The obtained vacuum threshold of the fuel tank-fuel pump section Design value of differential pressure for new fuel filter components Maximum pressure differential of used fuel filter parts Maximum allowable pressure difference in non-filter section By analyzing the pressure difference at each stage, the main sources of resistance can be accurately located, overcoming the limitation of total resistance measurement in distinguishing localized problems. The specific analysis process is carried out using the following formula:
[0042] , It is expressed as the absolute value of the pressure difference between the fuel tank and the front end of the filter;
[0043] , It is expressed as the absolute value of the pressure difference between the filter and the high-pressure oil pump inlet.
[0044] , It is expressed as the absolute value of the pressure difference between the fuel filter and the high-pressure fuel pump inlet.
[0045] Based on the location logic of the fuel tank-fuel pump section as the key resistance investigation section among the four measuring points, a vacuum gauge meeting the performance parameter C requirements of the testing equipment was installed at the fuel pump inlet. Under stable engine operating conditions, the measured vacuum degree of the fuel tank-fuel pump section was collected in real time. Measured vacuum level of fuel tank-fuel pump section This represents the measured vacuum level at the fuel pump inlet in the section from the fuel tank to the fuel pump. It is used to determine whether the coarse filter or fuel suction pipe in this section is blocked. It serves as the measured basis for judging the resistance of the fuel tank-fuel pump section. Comparison with the standard threshold can quickly identify whether there is a blockage problem in this section.
[0046] Measure the vacuum level of the fuel tank-fuel pump section. Compare the results with the segmented pressure difference results:
[0047] when > If this occurs, it is determined that the fuel tank-fuel pump section is blocked, and a level three anomaly record is generated;
[0048] when > or > If the resistance of the corresponding non-filter section exceeds the standard, a level four abnormality record will be generated.
[0049] When the new filter > or old filter > If this occurs, it indicates that the filter's flow capacity is insufficient or that it is clogged, and a Level 5 abnormality record is generated.
[0050] when ≤ , ≤ , ≤ And the new filter ≤ Old filter ≤ In such cases, the status quo is maintained, and only data recording is performed;
[0051] The results obtained from the joint comparison are summarized to generate a difference feedback signal. Different pressure difference exceeding the standard in different pipeline sections corresponds to different intensity and type of feedback signal, thus clarifying the main source of resistance.
[0052] Example 2: S4, the process of constructing the flow-resistance characteristic curve measurement using the curve analysis module; In the bench test, an adjustable flow device is used to simulate the fuel demand of the engine under different loads. Based on the key parameter A of the low-pressure oil circuit and the fuel flow demand range of the engine, an adjustable flow device that meets the performance parameter C requirements of the test equipment is used to set the flow value in a gradient, gradually adjusting it from 0 to Q. max The flow rate data corresponding to each gradient is labeled as the simulated fuel flow rate value Q;
[0053] Using the location parameters of four measuring points, the core positioning of the high-pressure oil pump at point 4 is achieved. A pressure sensor meeting the performance parameter C requirements of the testing equipment is added at the oil tank outlet at the starting point of the low-pressure oil circuit. The oil circuit starting pressure is simultaneously collected under each simulated fuel flow rate Q. and pressure at measuring point 4 Through formula ,in, This is expressed as the total pressure drop in the low-pressure oil circuit at the corresponding flow rate;
[0054] Extract the minimum required standard for the high-pressure oil pump inlet pressure under maximum flow rate from the key parameter A of the entire low-pressure oil circuit, and mark it as the minimum requirement for the high-pressure oil pump inlet pressure under maximum flow rate. The simulated fuel flow rate Q is plotted on the x-axis, and the total pressure drop in the low-pressure fuel circuit at the corresponding flow rate is plotted on the y-axis. Using the vertical axis as the ordinate, the flow-resistance characteristic curve is obtained by substituting the measured data into the fitting model. The curve equation can be expressed as follows: = k×Q + b, where k represents the slope of the curve, which represents the rate of increase of resistance with flow rate, and b represents the intercept; the complete flow-resistance characteristic curve is obtained, and the system design margin and rationality are evaluated by the slope of the curve and the pressure drop value at key flow points.
[0055] The S5 joint judgment module, after receiving the analysis results, performs a joint judgment analysis based on the results obtained from the analyses of S2, S3, and S4 to generate a reasonable measurement method. It summarizes and marks the remaining energy feedback signal and related data from S2 as comprehensive energy data D, the difference feedback signal and related data from S3 as comprehensive difference data E, and the flow-resistance characteristic curve and related data from S4 as comprehensive curve data F. It then performs a joint judgment based on four key evaluation indicators: high-pressure oil pump inlet pressure / vacuum, fuel filter pressure difference, the flow-resistance curve of the entire low-pressure oil circuit, and the pressure difference of each pipeline section. This verifies whether the low-pressure oil circuit design consistently maintains the high-pressure oil pump inlet pressure within a safe, stable, and sufficient range throughout the entire engine operating envelope, thereby generating a reasonable measurement method.
[0056] Step 1: Verify the inlet pressure / vacuum of the high-pressure oil pump. If the pressure (P) in the overall energy data (D) remains within the safe range specified by the high-pressure oil pump manufacturer, determine its reasonableness.
[0057] Determining absolute pressure value:
[0058] a) For push-type systems, the inlet pressure must not be lower than the minimum requirement under any operating conditions (especially cold start and high load), such as 0.5 bar;
[0059] b) For suction systems, the inlet vacuum level must not exceed the maximum permissible value, for example, -0.5 bar;
[0060] Pressure stability assessment:
[0061] c) The pressure / vacuum should remain stable without drastic fluctuations. Excessive fluctuations may indicate the presence of air in the system or an unstable fuel pump operation.
[0062] Step 2: Verify the fuel filter pressure differential, and the difference in the comprehensive data E. New parts must meet the following requirements: old filter ≤ If the initial pressure differential of the new filter is too high, it indicates that its flow capacity is insufficient or the model is not selected properly, and a new model needs to be selected. The rate of increase of the pressure differential of the filter can reflect its dust holding capacity and oil circuit cleanliness.
[0063] Step 3: The flow-resistance curve of the entire low-pressure oil circuit. The slope k of the curve in the comprehensive data F should be gentle, corresponding to the total pressure drop of the low-pressure oil circuit at the specified flow rate. The pressure difference from the minimum required pressure is > 0.2 bar to cope with the effects of gradual filter clogging, changes in oil quality, and changes in ambient temperature.
[0064] Step 4: Verify the pressure difference of each pipeline section and the difference in the comprehensive data E. , Need < The analysis results, based on the above four verification results, generate a complete measurement method covering equipment selection, measurement point layout, measurement steps, and index judgment, ensuring that it can systematically, quickly, and quantitatively evaluate the compliance of low-pressure oil circuits.
[0065] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.
[0066] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0067] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A novel method for measuring the low-pressure oil circuit of a diesel engine, characterized in that, Includes the following steps: S1. Determine the measurement range based on the target, and build a test system accordingly. Based on the cloud database, construct a measurement monitoring platform in conjunction with the test system to obtain key parameters A of the entire low-pressure oil circuit, position parameters B of the four measuring points, and performance parameters C of the test equipment, and send them to the total resistance risk assessment module, segmented resistance difference analysis module, and curve analysis module. S2, the total resistance risk assessment module collects the basic data of total resistance measurement and analyzes and generates the remaining energy feedback signal; S3, the segmented resistance difference analysis module collects the basic data of segmented resistance measurement and generates difference feedback signals through analysis of the basic data; S4, the curve analysis module jointly constructs and measures the flow-resistance characteristic curve based on relevant data from bench tests; S5, the joint judgment module processes the analysis results in a coordinated manner to generate a reasonable measurement method.
2. The method for measuring the low-pressure oil circuit of a new diesel engine according to claim 1, characterized in that, The stated objective of the diesel engine low-pressure fuel circuit measurement is to assess the flow resistance from the fuel tank to the high-pressure fuel pump inlet, ensuring that fuel is delivered in sufficient quantity with sufficiently low flow resistance and stable pressure. Based on this, the measurement range is determined to cover the entire path from the fuel tank to the high-pressure fuel pump inlet. Four key measurement points are selected: after the fuel pump outlet, before the fuel filter, after the fuel filter, and at the high-pressure fuel pump inlet. A test system is constructed, including a precision pressure gauge or pressure sensor, a flow meter, a vacuum gauge, and a data acquisition system. Based on the measurement range, the key parameters A of the entire low-pressure fuel circuit, the location parameters B of the four measurement points, and the performance parameters C of the test equipment are obtained.
3. The method for measuring the low-pressure oil circuit of a new diesel engine according to claim 1, characterized in that, The position parameters of the high-pressure oil pump inlet at measuring point 4 in the position parameter B of the four measuring points are used to determine the precise installation coordinates of the vacuum gauge or pressure sensor to ensure that the energy state data of the fuel delivery endpoint is collected. Combined with the performance requirements of the test equipment in the performance parameter C, the pressure value P is collected in real time by the equipment under different engine operating conditions. By directly extracting the upper limit standard of high-pressure oil pump inlet vacuum degree and the lower limit standard of high-pressure oil pump inlet vacuum degree corresponding to the target oil suction system from the key parameter A of the entire low-pressure oil circuit, the upper limit standard of vacuum degree is marked as the vacuum degree threshold of the oil suction system. .
4. The method for measuring the low-pressure oil circuit of a new diesel engine according to claim 3, characterized in that, After obtaining the pressure value P and the vacuum threshold of the oil suction system Minimum pressure value of push-type system design Subsequently, based on the fact that the inlet pressure of the high-pressure oil pump directly reflects the energy state of the fuel delivered to the destination, the following formula is used to obtain... and Retrieve the preset vacuum difference threshold and standard pressure threshold and compare them with... and Comparison: When When the vacuum difference exceeds the threshold limit, a Level 1 anomaly record is generated; when When the pressure exceeds the standard limit value, a secondary abnormality record is generated; when a primary or secondary abnormality record exists, a residual energy feedback signal is generated.
5. The method for measuring the low-pressure oil circuit of a new diesel engine according to claim 1, characterized in that, Based on the specific location parameters of the four measuring points in position parameter B, pressure sensors meeting the performance requirements of performance parameter C of the testing equipment were installed at the following locations: after the fuel pump outlet, before the fuel filter, after the fuel filter, and at the high-pressure fuel pump inlet. Under stable engine operating conditions, real-time pressure data values at each measuring point were synchronously collected and sequentially marked as follows: , , , .
6. The method for measuring the low-pressure oil circuit of a new diesel engine according to claim 5, characterized in that, The vacuum degree threshold corresponding to the fuel tank-fuel pump section is extracted from the key parameter A of the entire low-pressure oil circuit and marked as the fuel tank-fuel pump section vacuum threshold. ; Based on the relevant design data of the corresponding components recorded in the measurement and monitoring platform, the upper limit of the differential pressure for normal operation of the new fuel filter is obtained and marked as the design value of the differential pressure for the new fuel filter. ; The maximum allowable differential pressure of a used fuel filter is marked as the maximum differential pressure limit for used fuel filters. The maximum permissible pressure difference of the pipeline section other than the filter section is marked as the maximum permissible pressure difference of the non-filter section. Based on the formula analysis, the absolute value of the pressure difference from the oil tank to the front of the filter is obtained. The absolute value of the pressure difference between the filter and the high-pressure oil pump inlet. The absolute value of the pressure difference between the fuel filter and the high-pressure fuel pump inlet. .
7. A new method for measuring the low-pressure oil circuit of a diesel engine according to claim 6, characterized in that, The positioning logic identifies the fuel tank-fuel pump section as the key resistance investigation section based on the position parameters of the four measuring points. A vacuum gauge meeting the performance parameter C requirements of the testing equipment is installed at the fuel pump inlet. Under stable engine operating conditions, the measured vacuum degree of the fuel tank-fuel pump section is collected in real time. The actual vacuum degree of the fuel tank-fuel pump section was measured. Compare the results with the segmented pressure difference results: When > When, a level three exception record is generated; when > or > When, a level 4 exception record is generated; when ≤ , ≤ , ≤ And the new filter ≤ Old filter ≤ If necessary, maintain the status quo and only record data; summarize the results of the joint comparison and generate a difference feedback signal.
8. The method for measuring the low-pressure oil circuit of a new diesel engine according to claim 1, characterized in that, In bench testing, an adjustable flow device was used to simulate the fuel demand of the engine under different loads. Based on the key parameter A of the low-pressure fuel circuit and the fuel flow demand range of the engine, the adjustable flow device, which meets the performance parameter C of the test equipment, was used to set the flow value according to gradients. The flow data corresponding to each gradient was marked as the simulated fuel flow value Q, and the starting pressure of the fuel circuit was collected simultaneously. and pressure at measuring point 4 Through formula ,in, This is expressed as the total pressure drop of the low-pressure oil circuit at the corresponding flow rate.
9. A new method for measuring the low-pressure oil circuit of a diesel engine according to claim 8, characterized in that, Plot the simulated fuel flow rate Q on the x-axis and the total pressure drop in the low-pressure fuel circuit at the corresponding flow rate on the y-axis. Using the vertical axis as the ordinate, the flow-resistance characteristic curve is obtained by substituting the measured data into the fitting model. The curve equation can be expressed as follows: = k×Q + b, where k represents the slope of the curve, which represents the rate of increase of resistance with flow rate, and b represents the intercept, thus obtaining the flow-resistance characteristic curve.