A test method for verifying the strength of engine valve mechanism

Abstract

A test method for verifying the strength of an engine valve mechanism belongs to the field of engine technology. The method is as follows: conduct a combustion test on a test engine; analyze the combustion data obtained; conduct a test on the strength of the engine valve mechanism; decompose and inspect; evaluate the test results; and organize the test. The present invention can be applied to the engine product development stage to fully verify the reliability of the engine product, and can be used to solve the problem of eccentric wear of engine valves. It provides an effective verification method for solving the problem of eccentric wear of engine valves, quickly verifies the effectiveness of countermeasures, shortens the troubleshooting time for solving the problem, greatly improves the test verification efficiency, and has a good application prospect.

Description

Technical Field

[0001] The invention relates to an examination and testing method for verifying the strength of an engine valve mechanism, and belongs to the technical field of engines. Background Art

[0002] Engine reliability assessment tests usually include full-speed full-load durability, alternating load durability, hot and cold shock durability, etc. Even engines that have passed the above durability assessments may occasionally experience cylinder head valve eccentric wear failures during vehicle road tests or when customers are driving the vehicle. Obviously, conventional engine bench durability tests cannot verify cylinder head valve eccentric wear failures, so a test method to verify the strength of the engine valve mechanism is needed. Summary of the invention

[0003] In order to solve the problems existing in the background technology, the present invention provides an assessment test method for verifying the strength of an engine valve mechanism.

[0004] To achieve the above object, the present invention adopts the following technical solution: a test method for verifying the strength of an engine valve mechanism, the method comprising the following steps:

[0005] S1: Carry out combustion test on the test engine;

[0006] S2: Analyze the combustion data obtained in S1;

[0007] S3: Conduct the strength test of the engine valve mechanism;

[0008] S4: Decomposition inspection;

[0009] S5: Evaluate the test results;

[0010] S6: Experimental summary.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The present invention can be applied in the engine product development stage to fully verify the reliability of the engine product and can be used to solve the engine valve eccentric wear fault. It provides an effective verification means for solving the engine valve eccentric wear fault, quickly verifies the effectiveness of the countermeasures, shortens the troubleshooting time of the fault, greatly improves the test verification efficiency, and has a good application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the PV diagram of the test engine of the present invention at 3200r / min and 100% load;

[0014] Figure 2 It is the PV diagram of the test engine of the present invention at 3200r / min and 118Nm load. DETAILED DESCRIPTION

[0015] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. 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.

[0016] A test method for verifying the strength of an engine valve mechanism, the method comprising the following steps:

[0017] S1: Carry out combustion test on the test engine;

[0018] S101: Prepare all resources for combustion test and install cylinder pressure sensor, angle marker and wiring;

[0019] S102: Perform universal characteristic test at engine speed of 1000r / min-5500r / min and torque interval of 1bar, and record bench and combustion analysis data.

[0020] S2: Analyze the combustion data obtained in S1;

[0021] The test engine of the present invention uses a 1.5L supercharged engine. By analyzing the combustion data, it is found that the pressure rise rate in the combustion data is the largest when the engine is under medium load, while it becomes smaller when the corresponding speed is under full load. It can be clearly seen from the indicator diagram that the pressure mutation is fast when the engine is under partial load (see Figure 1 , Figure 2 The engine has a large combustion shock when it is under medium load at 1600r / min-3200r / min, which is the common driving condition for users. These operating points can be used as test conditions to verify the strength of the engine valve mechanism.

[0022] S3: Conduct the strength test of the engine valve mechanism;

[0023] S301: Carry out pre-test preparations;

[0024] S30101: Measure the dimensions of all test parts and components, and assemble the test engine in accordance with the operating standards after confirming that the parts meet the standards.

[0025] S30102: Install the test engine on the test bench, ensure that the test engine and the test bench are working properly, and do not run the engine in for a run-in period.

[0026] S302: Debugging test conditions;

[0027] In principle, the test is carried out under the following conditions. When the test is carried out under conditions other than the following, it should be stated in the test report.

[0028] a) Engine coolant outlet temperature: 100±3℃;

[0029] b) Oil temperature: below 140°C;

[0030] c) The remaining test conditions shall be controlled in accordance with Article 6 of GB / T 18297-2001.

[0031] S303: Perform an assessment test on the strength of the engine valve mechanism.

[0032] S30301: measuring cylinder pressure;

[0033] S30302: setting the speed of the test engine to 1600 r / min, setting the torque of the test engine to 100 Nm, and running the test engine for 1 hour;

[0034] S30303: setting the speed of the test engine to 2000 r / min, setting the torque of the test engine to 100 Nm, and running the test engine for 1 hour;

[0035] S30304: setting the speed of the test engine to 2500 r / min, setting the torque of the test engine to 120 Nm, and running the test engine for 1 hour;

[0036] S30305: setting the speed of the test engine to 3000 r / min, setting the torque of the test engine to 120 Nm, and running the test engine for 1 hour;

[0037] S30306: Cycle S30302-S30305 for 5 times, for a total of 20 hours;

[0038] S30307: Use 6 seconds to reduce the speed of the test engine to 1000 r / min, and reduce the torque of the test engine to 20%-30% of the full load at the speed;

[0039] S30308: increasing the speed of the test engine to 5000 r / min within 6 seconds, and increasing the torque of the test engine to 20%-30% of the full load at the speed;

[0040] S30309: Repeat S30307-S30308 20 times for a total of 4 minutes;

[0041] S303010: Repeat S30302-S30309 for 10 times, running the engine for a total of 200 hours and 40 minutes.

[0042] During operation, the cylinder pressure is measured every 50 hours and again after the assessment.

[0043] S4: Decomposition inspection;

[0044] During the disassembly inspection, use kerosene to conduct leakage tests on the intake valve side and exhaust valve side of the cylinder head, check the function, damage and wear of each component, take photos of the status of the components after durability, and perform differential measurements on differential measuring parts.

[0045] S5: Evaluate the test results;

[0046] The evaluation of the test results described in S5 includes evaluation during the assessment process and evaluation after the assessment is completed, wherein: during the evaluation during the assessment process, if the cylinder pressure value of the test engine drops by more than 30% of the initial cylinder pressure value, the assessment test is terminated, and the test engine is disassembled to check that there are no other abnormal problems with the test engine, then it is determined that the valve mechanism strength does not meet the design requirements, and the cylinder pressure drop caused by other abnormal problems of the engine does not fall within the scope of the valve mechanism strength determination; in the evaluation after the assessment is completed, the test engine is disassembled, and then leakage tests are performed on the intake valve side and the exhaust valve side of the cylinder head. If valve leakage occurs, it is determined that the valve mechanism strength does not meet the design requirements. If there is no valve leakage, the various components of the valve mechanism are differentially measured again. According to the measurement results at this time and the wear amount of the components combined with the differential measurement of S4, a final judgment is made on whether the strength of the various components of the valve mechanism is qualified according to relevant standards.

[0047] S6: Experimental summary.

[0048] According to the durability test requirements, organize the relevant test data, decompose the questionnaire and differential measurement results, and produce a test report.

[0049] The difficulty in actual work lies in obtaining the test conditions for engine operation. According to the fact that the engine will have cylinder head valve eccentric wear failure in conventional durability assessments, while the user's actual road conditions may only cause cylinder head valve eccentric wear failure, it is speculated that the engine eccentric wear condition may occur under partial load, which may not be related to the eccentric wear caused by engine overheating, but may be related to the combustion conditions of the engine under different working conditions and the impact force of the instantaneous seating of the combustion chamber valve. In the engine combustion test, the explosion pressure rise rate Rmax (bar / deg) in the combustion chamber can be obtained. By conducting a combustion test on the engine under universal characteristics, the pressure rise rate under various working conditions can be analyzed, and the point with a larger pressure rise rate can be selected as the reference working condition, thereby completing the selection of the working condition, and then organizing the engine to verify the effectiveness of the working condition according to the newly selected working condition.

[0050] Through the above test conditions verification, the valve eccentric wear fault of the 1.5L supercharged engine described in S2 reappeared, proving that this condition is effective in solving the problem of valve eccentric wear fault, solving the problem that the conventional durability test method cannot evaluate the fault, and this condition is very bad, which can quickly verify the effectiveness of the countermeasures, greatly shortening the troubleshooting time of the fault and improving the test efficiency. The present invention fills the gap in the test method for evaluating the strength of the engine valve mechanism. The application of this invention makes the engine durability assessment more sufficient, thereby improving the quality of the engine product. At the same time, it also provides an effective verification method for solving the problem of engine valve eccentric wear fault, and has a good application prospect.

[0051] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0052] 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 test method for verifying the strength of an engine valve mechanism, characterized in that: The method comprises the following steps: S1: Carry out combustion test on the test engine; S2: Analyze the combustion data obtained in S1; S3: Conduct the strength test of the engine valve mechanism; S301: Carry out pre-test preparations; S30101: Measure the dimensions of all test parts and components, and assemble the test engine in accordance with the operating standards after confirming that the parts meet the standards. S30102: Install the test engine on the test bench, ensure that the test engine and the test bench are working properly, and do not run the engine in a running-in operation; S302: Debugging test conditions; S303: Performing an assessment test on the strength of the engine valve mechanism; S30301: measuring cylinder pressure, determining and recording an initial cylinder pressure value; S30302: setting the speed of the test engine to 1600 r / min, setting the torque of the test engine to 100 Nm, and running the test engine for 1 hour; S30303: setting the speed of the test engine to 2000 r / min, setting the torque of the test engine to 100 Nm, and running the test engine for 1 hour; S30304: setting the speed of the test engine to 2500 r / min, setting the torque of the test engine to 120 Nm, and running the test engine for 1 hour; S30305: setting the speed of the test engine to 3000 r / min, setting the torque of the test engine to 120 Nm, and running the test engine for 1 hour; S30306: Cycle S30302-S30305 for 5 times; S30307: within 6 seconds, reduce the speed of the test engine to 1000 r / min, and reduce the torque of the test engine to 20%-30% of the full load at the speed; S30308: within 6 seconds, the test engine speed is increased to 5000 r / min, and the test engine torque is increased to 20%-30% of the full load at the speed; S30309: Repeat S30307-S30308 20 times; S303010: Repeat S30302-S30309 for a total of 10 times. During the operation, the cylinder pressure is measured every 50 hours, and the cylinder pressure is measured again after the assessment is completed. S4: Decomposition inspection; During the disassembly inspection, use kerosene to conduct a leak test on the intake valve side and exhaust valve side of the cylinder head; Check the function, damage and wear of each component; Take photos of the status of parts after durability; Perform differential measurement on differential measuring parts; S5: Evaluate the test results; The evaluation of the test results includes evaluation during the assessment process and evaluation after the assessment is completed, wherein: during the evaluation during the assessment process, if the cylinder pressure value of the test engine drops by more than 30% of the initial cylinder pressure value, the assessment test is terminated, and the test engine is disassembled to check that there are no other abnormal problems with the test engine, and it is determined that the strength of the valve mechanism does not meet the design requirements; when conducting the evaluation after the assessment is completed, the test engine is disassembled, and then a leakage test is performed on the intake valve side and the exhaust valve side of the cylinder head. If valve leakage occurs, it is determined that the strength of the valve mechanism does not meet the design requirements. If there is no valve leakage, the various components of the valve mechanism are differentially measured again, and the strength of the various components of the valve mechanism is finally determined to be qualified according to the measurement results at this time and the wear amount of the components combined with the differential measurement of S4 according to the relevant standards. S6: Experimental summary.

2. A test method for verifying the strength of an engine valve mechanism according to claim 1, characterized in that: The S1 comprises the following steps: S101: Prepare all tools for combustion test, and install cylinder pressure sensor, angle marker and wiring; S102: Perform universal characteristic test at engine speed of 1000r / min-5500r / min and engine torque interval of 1bar, and record bench and combustion analysis data.

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