VVT type engine phase angle reliability verification method

Abstract

The invention discloses a VVT type engine phase angle reliability verification method, and belongs to the technical field of engine tests. The method comprises the following steps: preparation work before a test; test condition control; opening overlapping angles of the intake valve and the exhaust valve are set according to calibration; the engine is warmed up; at least eight different working conditions are randomly selected, each working condition is verified in sequence, if the working conditions are not qualified, matching calibration is conducted on the VVT phase angle again according to the result, the opening overlapping angles of the intake valve and the exhaust valve are adjusted, and then the working conditions are repeated until the VVT phase angle is qualified; and if qualified, carrying out the next working condition. According to the invention, the influence of the opening overlapping angle and the VVT phase angle of the intake valve and the exhaust valve on the carbon deposition of the inner wall of the intake duct of the cylinder cover, the valve rod and the valve seat can be rapidly evaluated, and the carbon deposition condition of the valve assembly after the engine operates under the current matched calibration data can be visually displayed; therefore, the matching rationality of the opening overlapping angle and the VVT phase angle of the current intake valve and the exhaust valve can be accurately evaluated.

Description

Technical Field

[0001] The invention relates to a VVT type engine phase angle reliability verification method, belonging to the technical field of engine testing. Background Art

[0002] The VVT ​​system (variable valve timing system) optimizes the fuel economy and power output of the engine under different working conditions by precisely controlling the opening and closing time of the valves (valve timing). Specifically, the VVT ​​system relies on the OCV valve (oil pressure control valve) to drive the variable camshaft phaser, so that the camshaft rotation angle can be advanced or delayed, thereby achieving flexible adjustment of the valve timing.

[0003] However, the opening and closing time of the intake and exhaust valves is extremely short, usually in the millisecond range, which places extremely high demands on the calibration of the engine bench. During the engine calibration process, the intake and exhaust valve opening overlap angles and VVT phase angles need to be accurately optimized and matched. Improper matching may lead to problems such as insufficient engine intake and incomplete exhaust, which in turn affects the overall performance of the engine.

[0004] More seriously, improper matching may also cause incomplete combustion of the fuel in the combustion chamber. Under the action of high temperature and oxygen, the incompletely burned fuel will form hydrocarbon acid and resin-like colloids. If these colloids are not discharged from the combustion chamber in time, some of them will adhere to the surface of the valve assembly. After further action of high temperature, the colloids will turn into carbon deposits.

[0005] A large amount of carbon deposits on the working surface of the valve and valve seat will cause the valve to close loosely, which will lead to difficulties in starting the engine, weak operation, easy valve erosion, etc. At the same time, carbon deposits on the valve guide and valve stem will accelerate the wear of the valve stem and valve guide, making the movement of the valve stem in the valve guide become sluggish, and in severe cases even cause the valve to get stuck, eventually causing the engine to fail.

[0006] In view of the serious harm caused by the above-mentioned carbon deposits, in order to avoid engine failures caused by improper matching and calibration optimization of intake and exhaust valve opening overlap angles and VVT phase angles, the industry urgently needs an effective VVT ​​engine phase angle reliability verification method. Summary of the invention

[0007] In order to solve the problems existing in the background technology, the present invention provides a method for verifying the reliability of a phase angle of a VVT type engine.

[0008] To achieve the above object, the present invention adopts the following technical solution: a method for verifying the reliability of a phase angle of a VVT engine, the method comprising the following steps:

[0009] S1: Preparation before the test:

[0010] S2: experimental condition control;

[0011] S3: Conduct reliability verification tests.

[0012] S301: setting the opening overlap angles of the intake valve and the exhaust valve according to the calibration;

[0013] S302: Warming up the engine;

[0014] S303: randomly selecting a working condition from the actual driving road working conditions of the whole vehicle, and defining it as a first working condition;

[0015] S304: running in the first operating condition;

[0016] S305: After the first working condition is completed, disassemble the machine to check the carbon deposits on the inner wall of the cylinder head intake passage, valve stem and valve seat;

[0017] S306: Compare the carbon deposit conditions before and after the engine is running, and determine whether the intake valve and exhaust valve opening overlap angles are qualified under the first operating condition according to a preset evaluation standard.

[0018] If qualified, proceed to S307;

[0019] If it is unqualified, re-calibrate the VVT ​​phase angle according to the first working condition result and adjust the opening overlap angle of the intake valve and the exhaust valve, and repeat S304-S305 until the opening overlap angle of the intake valve and the exhaust valve is qualified;

[0020] S307: randomly selecting a different working condition from the actual driving road working condition of the vehicle again, and defining it as a second working condition;

[0021] S308: running the second operating condition;

[0022] S309: After the second working condition is completed, disassemble the machine to check the carbon deposits on the inner wall of the cylinder head intake passage, valve stem and valve seat;

[0023] S3010: Compare the carbon deposit conditions before and after the engine is running, and determine whether the intake valve and exhaust valve opening overlap angles are qualified under the second operating condition according to the preset evaluation criteria.

[0024] If qualified, proceed to S3011;

[0025] If it is unqualified, re-calibrate the VVT ​​phase angle and adjust the opening overlap angle of the intake valve and the exhaust valve according to the second working condition result, and repeat S304-S309 until the opening overlap angle of the intake valve and the exhaust valve is qualified;

[0026] S3011: According to the operation steps of the first working condition and the second working condition, at least eight different working conditions are randomly selected from the actual driving road conditions of the vehicle, until the opening overlap angles of the intake valve and the exhaust valve are qualified, and then S3012 is performed;

[0027] S3012: Selecting the operating condition with the largest opening overlap angle of the intake valve and the exhaust valve according to the map and performing continuous operation for 20 hours;

[0028] S3013: After the working condition with the largest overlap angle is completed, disassemble the machine to check the carbon deposits on the inner wall of the cylinder head intake duct, valve stem and valve seat;

[0029] S3014: Compare the carbon deposits before and after the engine is running, and determine whether the intake valve and exhaust valve overlap angles are qualified under the operating conditions according to the evaluation criteria.

[0030] If qualified, the reliability verification of the intake valve and exhaust valve is completed;

[0031] If it is unqualified, the VVT ​​phase angle is re-matched and calibrated according to the operating condition result with the largest overlap angle, and the intake valve and exhaust valve opening overlap angles are adjusted, and then S304-S3013 are repeated until the intake valve and exhaust valve opening overlap angles are qualified.

[0032] The first operating condition is: the engine runs continuously for 20 hours at a speed of 1500 r / min and a torque of 30% at 100% throttle;

[0033] The second operating condition is: the engine runs continuously for 20 hours at a speed of 1500 r / min and a torque of 50% at 100% throttle;

[0034] The third operating condition is: the engine runs continuously for 20 hours at a speed of 2000 r / min and a torque of 40% at 100% throttle;

[0035] The fourth operating condition is: the engine runs continuously for 20 hours at a speed of 2000 r / min and a torque of 50% at 100% throttle;

[0036] The fifth working condition is: the engine runs continuously for 20 hours at a speed of 2000 r / min and a torque of 65% at 100% throttle;

[0037] The sixth operating condition is: the engine runs continuously for 20 hours at a speed of 2500 r / min and a torque of 65% at 100% throttle;

[0038] The seventh working condition is: the engine runs continuously for 20 hours at a speed of 3000 r / min and a torque of 40% at 100% throttle;

[0039] The eighth working condition is: the engine runs continuously for 20 hours at a speed of 3500 r / min and a torque of 50% under 100% throttle.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention can quickly evaluate the influence of the opening overlap angle of the intake valve and the exhaust valve and the VVT ​​phase angle on the carbon deposition on the inner wall of the cylinder head intake passage, the valve stem and the valve seat, and intuitively display the carbon deposition of the valve assembly after the engine is running under the current matching calibration data, so as to accurately evaluate the matching rationality of the opening overlap angle of the current intake valve and the exhaust valve and the VVT ​​phase angle, and facilitate the electronic control calibration personnel to adjust the electronic injection data in time, and provide a strong basis and practical experience for the matching calibration optimization, design specification verification, calibration verification, reliability assessment and troubleshooting of the engine VVT ​​system, and has broad application prospects. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0043] A method for verifying the reliability of a phase angle of a VVT engine, the method comprising the following steps:

[0044] S1: Preparation before the test:

[0045] S101: Install the VVT ​​engine on the test bench, ensure that the engine and the test bench work properly, the engine has no water leakage, oil leakage, air leakage, and can start normally and smoothly;

[0046] S102: The engine does not require running-in.

[0047] S103: Before running the engine, check the carbon deposits on the inner wall of the cylinder head intake duct, valve stem and valve seat, take photos and record them.

[0048] S2: Test conditions shall be controlled in accordance with Article 6 of GB / T 18297-2001;

[0049] S3: Use the engine test bench to operate the VVT ​​engine and carry out reliability verification tests as required.

[0050] S301: setting the opening overlap angles of the intake valve and the exhaust valve according to the calibration;

[0051] S302: Warming up the engine: the engine speed under the warm-up condition reaches 2500 r / min and the torque reaches 56 N.m; at the same time, the engine oil temperature and the outlet water temperature are both above 90°C;

[0052] S303: randomly selecting a working condition from the actual driving road working conditions of the vehicle (engine speed range 1500r / min to 3500r / min, load range 30% to 65%), and defining it as the first working condition;

[0053] S304: running in the first operating condition;

[0054] S305: After the first working condition is completed, the machine is disassembled to check the carbon deposits on the inner wall of the cylinder head intake passage, valve stem and valve seat, and photographs are taken and recorded;

[0055] S306: Compare the carbon deposit conditions before and after the engine is running, and determine whether the intake valve and exhaust valve opening overlap angles are qualified under the first operating condition according to a preset evaluation standard.

[0056] If qualified, proceed to S307;

[0057] If it is unqualified, re-calibrate the VVT ​​phase angle according to the first working condition result and adjust the opening overlap angle of the intake valve and the exhaust valve, and repeat S304-S305 until the opening overlap angle of the intake valve and the exhaust valve is qualified;

[0058] If the comparative analysis results show no significant change, it is qualified, and this operating condition test is ended and the next operating condition test is carried out.

[0059] If the comparative analysis results show obvious carbon deposition, re-match and calibrate the VVT ​​phase angle, appropriately reduce the intake and exhaust overlap angles, and re-verify.

[0060] S307: randomly selecting a different working condition from the actual driving road working condition of the vehicle again, and defining it as a second working condition;

[0061] S308: running the second operating condition;

[0062] S309: After the second working condition is completed, disassemble the machine to check the carbon deposits on the inner wall of the cylinder head intake passage, valve stem and valve seat, and take photos and record them;

[0063] S3010: Compare the carbon deposit conditions before and after the engine is running, and determine whether the intake valve and exhaust valve opening overlap angles are qualified under the second operating condition according to the preset evaluation criteria.

[0064] If qualified, proceed to S3011;

[0065] If it is unqualified, re-calibrate the VVT ​​phase angle and adjust the opening overlap angle of the intake valve and the exhaust valve according to the second working condition result, and repeat S304-S309 until the opening overlap angle of the intake valve and the exhaust valve is qualified;

[0066] S3011: According to the operation steps of the first working condition and the second working condition, at least eight different working conditions are randomly selected from the actual driving road conditions of the vehicle, until the opening overlap angles of the intake valve and the exhaust valve are qualified, and then S3012 is performed;

[0067] S3012: Selecting the operating condition with the largest opening overlap angle of the intake valve and the exhaust valve according to the map and performing continuous operation for 20 hours;

[0068] S3013: After the working condition with the largest overlap angle is over, disassemble the machine to check the carbon deposits on the inner wall of the cylinder head intake duct, valve stem and valve seat, take photos and record them;

[0069] S3014: Compare the carbon deposits before and after the engine is running, and determine whether the intake valve and exhaust valve overlap angles are qualified under the operating conditions according to the evaluation criteria.

[0070] If qualified, the reliability verification of the intake valve and exhaust valve is completed;

[0071] If it is unqualified, the VVT ​​phase angle is re-matched and calibrated according to the operating condition result with the largest overlap angle, and the intake valve and exhaust valve opening overlap angles are adjusted, and then S304-S3013 are repeated until the intake valve and exhaust valve opening overlap angles are qualified.

[0072] The first operating condition is: the engine runs continuously for 20 hours at a speed of 1500 r / min and a torque of 30% at 100% throttle;

[0073] The second operating condition is: the engine runs continuously for 20 hours at a speed of 1500 r / min and a torque of 50% at 100% throttle;

[0074] The third operating condition is: the engine runs continuously for 20 hours at a speed of 2000 r / min and a torque of 40% at 100% throttle;

[0075] The fourth operating condition is: the engine runs continuously for 20 hours at a speed of 2000 r / min and a torque of 50% at 100% throttle;

[0076] The fifth working condition is: the engine runs continuously for 20 hours at a speed of 2000 r / min and a torque of 65% at 100% throttle;

[0077] The sixth operating condition is: the engine runs continuously for 20 hours at a speed of 2500 r / min and a torque of 65% at 100% throttle;

[0078] The seventh working condition is: the engine runs continuously for 20 hours at a speed of 3000 r / min and a torque of 40% at 100% throttle;

[0079] The eighth working condition is: the engine runs continuously for 20 hours at a speed of 3500 r / min and a torque of 50% under 100% throttle.

[0080] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalents of the claims be included in the present invention.

[0081] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for verifying the reliability of a phase angle of a VVT engine, characterized in that: The method comprises the following steps: S1: Preparation before the test: S2: experimental condition control; S3: Conduct reliability verification test.

2. A VVT engine phase angle reliability verification method according to claim 1, characterized in that: The S3 comprises the following steps: S301: setting the opening overlap angles of the intake valve and the exhaust valve according to the calibration; S302: Warming up the engine; S303: randomly selecting a working condition from the actual driving road working conditions of the whole vehicle, and defining it as a first working condition; S304: running in the first operating condition; S305: After the first working condition is completed, disassemble the machine to check the carbon deposits on the inner wall of the cylinder head intake passage, valve stem and valve seat; S306: Compare the carbon deposit conditions before and after the engine is running, and determine whether the intake valve and exhaust valve opening overlap angles are qualified under the first operating condition according to a preset evaluation standard. If qualified, proceed to S307; If it is unqualified, re-calibrate the VVT ​​phase angle according to the first working condition result and adjust the opening overlap angle of the intake valve and the exhaust valve, and repeat S304-S305 until the opening overlap angle of the intake valve and the exhaust valve is qualified; S307: randomly selecting a different working condition from the actual driving road working condition of the vehicle again, and defining it as a second working condition; S308: running the second operating condition; S309: After the second working condition is completed, disassemble the machine to check the carbon deposits on the inner wall of the cylinder head intake passage, valve stem and valve seat; S3010: Compare the carbon deposit conditions before and after the engine is running, and determine whether the intake valve and exhaust valve opening overlap angles are qualified under the second operating condition according to the preset evaluation criteria. If qualified, proceed to S3011; If it is unqualified, re-calibrate the VVT ​​phase angle and adjust the opening overlap angle of the intake valve and the exhaust valve according to the second working condition result, and repeat S304-S309 until the opening overlap angle of the intake valve and the exhaust valve is qualified; S3011: According to the operation steps of the first working condition and the second working condition, at least eight different working conditions are randomly selected from the actual driving road conditions of the vehicle, until the opening overlap angles of the intake valve and the exhaust valve are qualified, and then S3012 is performed; S3012: Selecting the operating condition with the largest opening overlap angle of the intake valve and the exhaust valve according to the map and performing continuous operation for 20 hours; S3013: After the working condition with the largest overlap angle is completed, disassemble the machine to check the carbon deposits on the inner wall of the cylinder head intake duct, valve stem and valve seat; S3014: Compare the carbon deposits before and after the engine is running, and determine whether the intake valve and exhaust valve overlap angles are qualified under the operating conditions according to the evaluation criteria. If qualified, the reliability verification of the intake valve and exhaust valve is completed; If it is unqualified, the VVT ​​phase angle is re-matched and calibrated according to the operating condition result with the largest overlap angle, and the intake valve and exhaust valve opening overlap angles are adjusted, and then S304-S3013 are repeated until the intake valve and exhaust valve opening overlap angles are qualified.

3. A VVT engine phase angle reliability verification method according to claim 2, characterized in that: The first operating condition is: the engine runs continuously for 20 hours at a speed of 1500 r / min and a torque of 30% at 100% throttle; The second operating condition is: the engine runs continuously for 20 hours at a speed of 1500 r / min and a torque of 50% at 100% throttle; The third operating condition is: the engine runs continuously for 20 hours at a speed of 2000 r / min and a torque of 40% at 100% throttle; The fourth operating condition is: the engine runs continuously for 20 hours at a speed of 2000 r / min and a torque of 50% at 100% throttle; The fifth working condition is: the engine runs continuously for 20 hours at a speed of 2000 r / min and a torque of 65% at 100% throttle; The sixth operating condition is: the engine runs continuously for 20 hours at a speed of 2500 r / min and a torque of 65% at 100% throttle; The seventh working condition is: the engine runs continuously for 20 hours at a speed of 3000 r / min and a torque of 40% at 100% throttle; The eighth working condition is: the engine runs continuously for 20 hours at a speed of 3500 r / min and a torque of 50% under 100% throttle.