Search

CN-116104672-B - Engine oil injection advance angle monitoring method and engine system

CN116104672BCN 116104672 BCN116104672 BCN 116104672BCN-116104672-B

Abstract

The invention discloses an engine oil injection advance angle monitoring method and an engine system, wherein the engine oil injection advance angle monitoring method acquires a first vibration acceleration-time map in real time according to a first vibration acceleration sensor; acquiring a second vibration acceleration-time map in real time according to a second vibration acceleration sensor, acquiring a vibration acceleration-time map of an oil sprayer through the first map and the second map, acquiring oil spraying starting time t1 according to the vibration map of the oil sprayer, acquiring time t2 when a cylinder reaches a top dead center, and calculating according to theta=6n (t 2-t 1)/1000 to obtain an oil spraying advance angle. The oil injection advance angle can be monitored in real time on the premise of not disassembling the engine, the monitoring method is simple, and compared with the engine oil injection advance angle monitoring method in the prior art, the method is suitable for engines of different types, and has good universality.

Inventors

  • An Yankui
  • ZHANG WENQIANG

Assignees

  • 潍柴重机股份有限公司

Dates

Publication Date
20260505
Application Date
20230222

Claims (7)

  1. 1. The engine oil injection advance angle monitoring method is characterized in that a first vibration acceleration sensor is arranged at an oil injector or a high-pressure oil pipe connected with the oil injector, a second vibration acceleration sensor is arranged at an engine cylinder cover, and the engine oil injection advance angle monitoring method comprises the following steps: acquiring a first vibration signal in real time according to the first vibration acceleration sensor, and generating a first map, wherein the first map is a first vibration acceleration-time map; acquiring a second vibration signal in real time according to the second vibration acceleration sensor, and generating a second map, wherein the second map is a second vibration acceleration-time map; Acquiring a fuel injector vibration map according to the first map and the second map, wherein the fuel injector vibration map is a fuel injector vibration acceleration-time map; Acquiring the starting oil injection time t1 according to the oil injector vibration spectrum; Acquiring the time t2 when the piston reaches the top dead center; calculating to obtain an oil injection advance angle according to theta=6n (t 2-t 1)/1000, wherein theta is the oil injection advance angle, ° CA, n is the real-time rotating speed of the engine, r/min, t1 is the oil injection starting time, ms, and t2 is the time when the piston reaches the top dead center, ms; The specific steps of acquiring the vibration spectrum of the fuel injector according to the first spectrum and the second spectrum comprise the following steps: Subtracting the second vibration acceleration at the same moment from the first vibration acceleration at the same moment to obtain a third vibration acceleration, and generating a third map, wherein the third map is a third vibration acceleration-time map; Performing Fourier transform on the third vibration acceleration of the third map, filtering, and generating a vibration map of the fuel injector; the specific step of acquiring the starting oil injection time t1 according to the oil injector vibration spectrum comprises the following steps: calculating a slope value between any two adjacent coordinate points; Obtaining a maximum slope value from each slope value; And taking the moment value corresponding to the first coordinate point in the two coordinate points corresponding to the maximum slope value as the starting oil injection moment t1.
  2. 2. The method for monitoring the advance angle of fuel injection of an engine according to claim 1, wherein the engine crankshaft is provided with an angle sensor, and the specific step of acquiring the time t2 when the piston reaches the top dead center comprises the steps of: acquiring a crank angle in real time according to the angle sensor, and generating a crank angle map, wherein the crank angle map is a crank angle-time map; And acquiring the moment when the first crank angle is zero after the starting oil injection moment t1 according to the crank angle map, wherein the moment is the moment t2 when the piston reaches the top dead center.
  3. 3. The method for monitoring the advance angle of fuel injection of an engine according to claim 1, wherein the engine cylinder is provided with a pressure sensor, and the specific step of acquiring the time t2 when the piston reaches the top dead center comprises the following steps: acquiring cylinder pressure in real time according to the pressure sensor, and generating a cylinder pressure map, wherein the cylinder pressure map is a cylinder pressure-time map; And acquiring the moment corresponding to the maximum value of the pressure of the first cylinder after the starting oil injection moment t1 according to the pressure map of the cylinder, wherein the moment is the moment t2 when the piston reaches the top dead center.
  4. 4. The method for monitoring the advance angle of fuel injection of an engine according to claim 1, wherein the engine crankshaft is provided with an angle sensor, and the specific step of acquiring the time t2 when the piston reaches the top dead center comprises the steps of: acquiring a crank angle in real time according to the angle sensor; Calculating the position of the piston in an engine cylinder in real time according to the crank angle; calculating the volume of an engine cylinder according to the position of the piston in the engine cylinder; Judging whether the volume of the engine cylinder is smaller than or equal to a set volume value after the oil injection starting time t 1; And if the volume of the engine cylinder is smaller than or equal to the set volume value, taking the moment when the volume of the first engine cylinder is smaller than or equal to the set volume value as the moment t2 when the piston reaches the top dead center.
  5. 5. The method for monitoring the fuel injection advance of the engine according to claim 1, further comprising the steps of, after calculating the fuel injection advance according to θ=6n (t 2-t 1)/1000: acquiring a plurality of oil injection advance angles corresponding to a plurality of crankshaft rotating speeds; Calculating the average value of a plurality of oil injection advance angles, wherein the average value is the average value of the oil injection advance angles; And judging whether the average value of the oil injection advance angle is normal or not.
  6. 6. The engine oil injection advance angle monitoring method according to claim 5, wherein the specific step of judging whether the average value of the oil injection advance angle is normal comprises: judging whether the average value of the oil injection advance angles is in a set oil injection advance angle range or not; If the average value of the oil injection advance angles is in the set oil injection advance angle range, the average value of the oil injection advance angles is normal; and if the average value of the oil injection advance angles is not in the set oil injection advance angle range, an alarm is sent out.
  7. 7. An engine system for implementing the engine fuel injection advance angle monitoring method according to any one of claims 1 to 6.

Description

Engine oil injection advance angle monitoring method and engine system Technical Field The invention relates to the technical field of engines, in particular to an engine oil injection advance angle monitoring method and an engine system. Background The engine oil injection advance angle refers to the crank angle corresponding to the top of the piston from the top dead center when the oil injector is started and the oil is injected into the cylinder. Too small oil injection advance angle can cause serious post combustion of the engine, high fuel consumption rate, high exhaust temperature, black smoke and other symptoms. The oil injection advance angle is too large, so that the problems of rough engine operation, unstable operation, increased mechanical load, even cylinder pulling and the like are caused, and if the oil injection advance angle is not in accordance with the requirements, the power performance and the economy of the engine are affected. In the prior art, methods for detecting the oil injection advance angle mainly comprise two types, namely static detection, measurement of the oil supply advance angle of an oil pump is generally carried out through an oil dripping method and a pre-lift method, and dynamic detection. For the method of dynamic detection, in the method of monitoring the advance angle of engine oil injection in the prior art, oil injection rules of an oil injection pump and a high-pressure oil pipe are required to be tested, and vibration signals are calibrated by using the measured oil injection rules, so that the corresponding relation between the vibration signals and the advance angle of oil injection is obtained. According to the engine oil injection advance angle monitoring method, if the engine types are different, vibration signals need to be calibrated again, the universality is poor, and the testing process is complex. Disclosure of Invention The invention aims to provide an engine oil injection advance angle monitoring method and an engine system, which are used for solving the problems that vibration signals are required to be calibrated again for different engine models, the universality is poor and the testing process is complicated in the engine oil injection advance angle monitoring method in the prior art. To achieve the purpose, the invention adopts the following technical scheme: the method for monitoring the oil injection advance angle of the engine comprises the steps that a first vibration acceleration sensor is arranged at a position of an oil injector or a high-pressure oil pipe connected with the oil injector, a second vibration acceleration sensor is arranged on a cylinder cover of the engine, and the method for monitoring the oil injection advance angle of the engine comprises the following steps: acquiring a first vibration signal in real time according to the first vibration acceleration sensor, and generating a first map, wherein the first map is a first vibration acceleration-time map; acquiring a second vibration signal in real time according to the second vibration acceleration sensor, and generating a second map, wherein the second map is a second vibration acceleration-time map; Acquiring a fuel injector vibration map according to the first map and the second map, wherein the fuel injector vibration map is a fuel injector vibration acceleration-time map; Acquiring the starting oil injection time t1 according to the oil injector vibration spectrum; Acquiring the time t2 when the piston reaches the top dead center; and calculating to obtain an oil injection advance angle according to theta=6n (t 2-t 1)/1000, wherein theta is the oil injection advance angle, CA, n is the real-time rotating speed of the engine, r/min, t1 is the oil injection starting time, ms, and t2 is the time when the piston reaches the top dead center, ms. Preferably, the specific step of acquiring the vibration spectrum of the fuel injector according to the first spectrum and the second spectrum comprises the following steps: Subtracting the second vibration acceleration at the same moment from the first vibration acceleration at the same moment to obtain a third vibration acceleration, and generating a third map, wherein the third map is a third vibration acceleration-time map; And carrying out Fourier transform on the third vibration acceleration of the third map, filtering, and generating the oil sprayer vibration map. Preferably, the specific step of acquiring the starting injection time t1 according to the vibration spectrum of the fuel injector includes: calculating slope values between any two adjacent coordinate points (first fuel injector vibration acceleration, first moment) and (second fuel injector vibration acceleration, second moment); Obtaining a maximum slope value from each slope value; And taking the moment value corresponding to the first coordinate point in the two coordinate points corresponding to the maximum slope value as the starting oil injection moment