Method for testing friction force and viscous friction coefficient of fuel metering valve

Abstract

The invention relates to the technical field of friction force and friction technology testing, and particularly discloses a fuel metering valve friction force and viscous friction coefficient testing method which comprises the following steps: firstly, selecting a test metering valve sample; secondly, designing and manufacturing a test tool; secondly, compiling and issuing a test scheme; and finally, performing experimental testing and data analysis to form a data file. According to the method for testing the friction force and the viscous friction coefficient of the fuel metering valve, the friction force testing principle and the viscous friction coefficient testing principle of the valve are learned and understood more systematically through experimental testing, and a foundation is laid for follow-up related experimental testing and research.

Description

Technical Field

[0001] The invention relates to the field of friction force and friction technology testing technology, in particular to a method for testing the friction force and viscous friction coefficient of a fuel metering valve. Background Art

[0002] Aircraft engine control systems are inseparable from hydraulic mechanical actuators. For example, the fuel metering device controls the engine by controlling the flow rate through a metering valve. The movement of the metering valve is affected by friction and viscous friction coefficient. Therefore, it is necessary to test and study the valve friction and viscous friction coefficient.

[0003] Among them, the metering module is the core functional module of the aircraft engine control accessories, and its control accuracy directly affects the normal operation of the accessories. When simulating the hole, the friction force and the viscous friction coefficient are estimated values, which are quite different from the actual values ​​and have a certain impact on the valve simulation design results. Summary of the invention

[0004] The purpose of the present invention is to provide a method for testing the friction force and viscous friction coefficient of a fuel metering valve, which can be used to test the friction force and viscous friction coefficient of the metering valve, obtain test data, and provide data support for subsequent valve simulation design.

[0005] To achieve the above object, the present invention provides a method for testing the friction force and viscous friction coefficient of a fuel metering valve, comprising the following steps:

[0006] S1. Select the test metering valve sample;

[0007] S2. Design and manufacture of test tooling;

[0008] S3. Preparation and issuance of test plans;

[0009] S4. Experimental testing and data analysis to form data files.

[0010] Preferably, in S1, the test metering valve sample selection is completed by determining the sample valve shape, valve material, valve gap and valve quantity.

[0011] Preferably, in S1, the XX-12 metering valve assembly of the nozzle control device is selected as the carrier prototype;

[0012] The valve materials include 9Cr18, 6061-T6 and 4Cr14Ni14W2Mo, and the surface of the valve materials is treated;

[0013] The valve clearance includes three types: 0.006mm~0.01mm, 0.012mm~0.018mm, and 0.018mm~0.026mm;

[0014] According to the valve material and valve clearance, nine types of valves including three valve materials 9Cr18, 6061-T6, 4Cr14Ni14W2Mo and three valve clearances of 0.006mm~0.01mm, 0.012mm~0.018mm, and 0.018mm~0.026mm were selected for testing.

[0015] Preferably, in S2, the test tooling is designed according to the sample valve dimensions in S1, specifically, the test tooling is designed according to the dimensions of the test carrier XXA-12 metering valve assembly and the tester structure, and the tooling is manufactured after the test tooling design is completed.

[0016] Preferably, S3 specifically includes the following steps:

[0017] S31. Determination of the test carrier of the metering valve assembly;

[0018] S32, the valve assembly test carrier is drawn using UG software;

[0019] S33. Process and manufacture metering valves according to test requirements;

[0020] S34. Design and preparation of experimental plan.

[0021] Preferably, S34 specifically includes the following steps:

[0022] S341. Soak the test carrier in oil. Keep the oil tank pressure-free during the test.

[0023] S342. Determine the friction force and friction coefficient test data at different temperatures. Based on 20℃±3℃, test one set of data every time the temperature rises by 10℃. Test six sets of data for the friction force of each valve and three sets of data for the viscous friction coefficient. The highest test temperature is 150℃±3℃.

[0024] Preferably, in S4, the viscous damping of the valve is tested using the amplitude-frequency characteristic curve of the single-degree-of-freedom spring oscillator system, and the viscous friction coefficient is tested using a dynamic testing method.

[0025] Preferably, the single-degree-of-freedom spring oscillator system includes a horizontally arranged three-dimensional manual displacement platform and a valve test assembly, on which an exciter-side laser displacement sensor and an exciter are arranged in sequence, a spring is arranged between the valve test assembly and the exciter, and a valve-side laser displacement sensor is arranged on the side of the valve test assembly away from the spring.

[0026] Therefore, the present invention adopts the above-mentioned test method for the friction force and viscous friction coefficient of the fuel metering valve, and the beneficial effects are as follows:

[0027] The test method of the friction force and viscous friction coefficient of the metering valve of the present invention fills the gap in the test of the friction force and viscous friction coefficient of the metering valve. Through the test, the test principle of the friction force and viscous friction coefficient of the valve is more systematically studied and understood, laying a foundation for subsequent related test and research.

[0028] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flow chart of an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0030] Figure 2 It is a schematic diagram of the structure of a XXA-12 metering valve assembly according to an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0031] Figure 3 It is a design diagram of a mounting seat of an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention, wherein (a) is an overall cross-sectional view, and (b) is a left side view;

[0032] Figure 4 It is a design diagram of a connecting rod 1 connecting one end of the valve and the spherical bearing in an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0033] Figure 5 It is a front view of the design of a connecting rod 2 connecting a spherical bearing and a force sensor in an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0034] Figure 6 It is a design left view of a connecting rod 2 connecting a spherical bearing and a force sensor in an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0035] Figure 7 It is a design diagram of a connecting rod 3 connected to the other end of the valve in an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0036] Figure 8 It is a friction force test tooling diagram of an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0037] Fig. 9 It is a front end cover plate diagram of a friction force test tooling of an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0038] Fig.10 It is a test fixture diagram of a viscous friction coefficient test of an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0039] Fig.11 It is a front end cover plate diagram of a viscous friction coefficient test tooling for testing the friction force and viscous friction coefficient of a fuel metering valve according to an embodiment of the present invention;

[0040] Fig.12 It is a diagram of a viscous friction coefficient test tooling pressure plate of an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0041] Fig.13 It is a friction force test principle diagram of an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0042] Fig.14 It is a valve spring mass system principle diagram of an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0043] Fig.15 It is a schematic diagram of the composition of a viscous friction coefficient detection system of an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0044] Fig.16 It is a principle block diagram of a viscous friction coefficient detection system of an embodiment of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention;

[0045] Fig.17 The present invention is a method for testing the friction force and viscous friction coefficient of a fuel metering valve. The carrier of the first embodiment is XXA-SY18 (1ZS4, 1ZS5), and the gap is 0.006mm-0.010mm. The static friction force, dynamic friction force and temperature relationship curve;

[0046] Fig.18 The present invention is a method for testing the friction force and viscous friction coefficient of a fuel metering valve. The carrier of the first embodiment is XXA-SY18 (1ZS6, 1ZS4), and the gap is 0.006mm-0.010mm. The static friction force, dynamic friction force and temperature relationship curve;

[0047] Fig.19 The present invention is a method for testing the friction force and viscous friction coefficient of a fuel metering valve. The carrier of Example 1 is XXA-SY18 (1ZS2, 1ZS1), and the gap is 0.006mm-0.010mm. The relationship between static friction force, dynamic friction force and temperature is a curve diagram;

[0048] Fig. 20The present invention is a method for testing the friction force and viscous friction coefficient of a fuel metering valve. The carrier of Example 2 is XXA-SY19 (1ZS3, 1ZS3), and the gap is 0.012mm-0.018mm. The relationship between static friction force, dynamic friction force and temperature is a curve;

[0049] Fig.21 The present invention is a method for testing the friction force and viscous friction coefficient of a fuel metering valve. The carrier of Example 3 is XXA-SY20 (1ZS3, 1ZS3), and the gap is 0.018mm-0.026mm. The relationship between static friction force, dynamic friction force and temperature is a curve;

[0050] Fig. 22 It is a carrier XXA-SY20 (1ZS4, 1ZS4) of Embodiment 3 of a method for testing the friction force and viscous friction coefficient of a fuel metering valve of the present invention, and a curve diagram showing the relationship between static friction force, dynamic friction force and temperature with a gap of 0.018 mm to 0.026 mm;

[0051] Fig.23 The present invention is a fuel metering valve friction force, viscous friction coefficient test method embodiment 3 of the carrier XXA-SY20 (1ZS2, 1ZS1), the gap is 0.018mm ~ 0.026mm static friction force, dynamic friction force and temperature relationship curve.

[0052] Reference numerals

[0053] 1. 3D manual displacement platform; 2. Laser displacement sensor on the vibrator side; 3. Vibrator; 4. Spring; 5. Valve test assembly; 6. Laser displacement sensor on the valve side; 7. Measuring valve; 8. Bushing; 9. First heat exchange shell; 10. First measuring rod; 11. Bushing 12 tooling; 12. Nut M4; 13. First connecting rod; 14. Nut M6; 15. Spherical bearing S16; 16. Elastic cylindrical pin 6; 17. First connecting rod; 18. First end cover; 19. First O-ring; 20. Second O-ring Sealing ring; 21. third O-ring; 22. first spacer ring; 23. retaining ring D42 for hole; 24. fourth O-ring; 25. second heat exchange shell; 26. second measuring rod; 27. bushing 2320 tooling; 28. bushing 2320 pressure plate; 29. ​​second hexagon socket screw M3X10; 30. second gasket 3; 31. second connecting rod; 32. second end cover; 33. fifth O-ring; 34. sixth O-ring; 35. seventh O-ring; 36. second spacer ring; 37. eighth O-ring. DETAILED DESCRIPTION

[0054] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0055] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0056] As shown in the figure, a method for testing the friction force and viscous friction coefficient of a fuel metering valve includes the following steps:

[0057] S1. Selecting a test metering valve sample. Specifically, selecting the test metering valve sample by determining the sample valve shape, valve material, valve gap and valve quantity.

[0058] 1. Sample prototype valve selection

[0059] The friction force and viscous friction coefficient test of the metering valve are carried out on the precision valve pair life tester. In the afterburner fuel control system, the afterburner is the core product of the afterburner system. Figure 2 As shown, this test selected the XX-12 metering valve assembly of the nozzle control device as the carrier prototype. In the figure, 7 is the metering valve and 8 is the bushing.

[0060] 2. Determination of valve material

[0061] Considering the actual use and test requirements, the valve materials finally selected include 9Cr18, 6061-T6 and 4Cr14Ni14W2Mo. According to the material properties and valve hardness requirements, combined with the actual valve surface treatment, the surfaces of the three valve materials are treated. The specific treatment requirements are shown in Table 1:

[0062] Table 1 Valve material processing requirements

[0063]

[0064] 3. Determination of valve clearance

[0065] The valve clearance includes three categories: 0.006mm~0.01mm, 0.012mm~0.018mm, and 0.018mm~0.026mm. The final valve test carrier clearance is designed according to these three categories.

[0066] 4. Determination of the number of valves

[0067] According to the valve manufacturing materials and valve clearance, three materials 9Cr18, 6061-T6, 4Cr14Ni14W2Mo and three valve clearances of 0.006mm~0.01mm, 0.012mm~0.018mm, 0.018mm~0.026mm were finally selected, totaling nine types of valves. Due to the differences in test data during the test, it was determined that 3 sets of each type of valve were manufactured for testing. The test results were determined through statistics. The specific combination and quantity of the metering valve components are shown in Table 2:

[0068] Table 2 Valve combination

[0069]

[0070] S2. Design and manufacture of test tooling;

[0071] Due to the particularity of the precision valve pair life tester, the friction and viscous friction coefficient tests need to be designed according to the sample valve size in S1. The quality of the test fixture design can directly affect the test results. The selection of test samples for the metering valve friction and viscous friction coefficient test is to design the test fixture according to the size of the test carrier XXA-12 metering valve assembly and the tester structure, such as Figure 3-Figure 12 As shown in the figure, after the test tooling design is completed, the tooling manufacturing is carried out in a timely manner.

[0072] Figure 3 It is a valve mounting seat. After the valve is installed inside, it is fixed by a retaining spring. Figure 4 One end is threadedly connected to the valve, and the other end is threadedly connected to the spherical bearing; Figure 5 ( Figure 6 ) one end is threadedly connected to the force sensor, and the other end is threadedly connected to the spherical bearing; Figure 7 One end is threadedly connected to the valve, and the other end is threadedly connected to the laser reflective block; Figure 8 Fixed in the tester cavity by screws; Fig.10 It is fixed on the front end of the mounting base by screws.

[0073] S3. Preparation and issuance of the test plan, including the following steps:

[0074] S31. Determination of the test carrier of the metering valve assembly;

[0075] According to the test requirements, combined with the metering valve prototype and material, clearance and other requirements, determine the test carrier. The specific valve test carrier requirements are shown in Table 3:

[0076] Table 3 Requirements for valve test carrier

[0077]

[0078] S32, the valve assembly test carrier is drawn using UG software;

[0079] According to the test requirements, combined with the metering valve prototype and material, gap and other requirements, the three-dimensional diagram of the test carrier is drawn.

[0080] S33. Process and manufacture the metering valve according to the test requirements.

[0081] S34. Experimental design and preparation, including the following steps:

[0082] S341. To simulate the working state of the metering valve, the test carrier needs to be immersed in oil during the friction and viscous friction coefficient tests. To prevent the oil pressure from interfering with the friction test, the oil tank needs to be kept pressure-free during the test.

[0083] S342. Since temperature has a certain influence on oil viscosity, valve volume, etc., the friction force and friction coefficient test data at different temperatures are measured. Combined with the test operability, based on 20℃±3℃, a set of data is tested for each 10℃ increase in temperature. Six sets of data are tested for each valve friction force, and three sets of data are tested for the viscous friction coefficient. The highest test temperature is 150℃±3℃. Then, according to the test requirements, the test plan is compiled.

[0084] The friction force test principle of this embodiment is as follows Fig.13 As shown, the driving motor is connected to the force sensor and the metering valve. The displacement of the metering valve is measured by the "laser ranging" on the left. Given a certain movement speed, the driving motor drives the metering valve to move, and the friction force value is directly read by the force sensor and transmitted to the computer control system, and directly read through the software.

[0085] The viscous friction coefficient test of the present embodiment uses the amplitude-frequency characteristic curve of the single-degree-of-freedom spring oscillator system to test the viscous damping of the valve, and adopts a dynamic test method to test the viscous friction coefficient. The single-degree-of-freedom spring oscillator system includes a horizontally arranged three-dimensional manual displacement platform 1 and a valve test assembly 5. The three-dimensional manual displacement platform 1 is sequentially provided with an exciter-side laser displacement sensor 2 and an exciter 3. A spring 4 is provided between the valve test assembly 5 and the exciter 3. A valve-side laser displacement sensor 6 is provided on the side of the valve test assembly 5 away from the spring 4. Connection method: The exciter-side laser displacement sensor 2 and the exciter 3 are fixed to the three-dimensional manual displacement platform 1 with screws, and the exciter 3, the spring 4, and the valve test assembly 5 are connected with screws; the exciter-side laser displacement sensor 2 and the valve-side laser displacement sensor 6 sense the laser feedback to measure the displacement. Its principle diagram is shown as follows Fig.14 As shown, the test equipment consists of Fig.15 shown.

[0086] The principle of viscous friction coefficient test is as follows:

[0087] The excitation source is a high-frequency vibrator, which converts electrical energy into mechanical energy to provide exciting force to the valve.

[0088] Its working principle can be expressed by the following formula:

[0089] F=1020BLI=αl

[0090] Where:

[0091] F represents the electromagnetic induction force, i.e. the exciting force (N);

[0092] B represents the average magnetic induction intensity in the working air gap (T);

[0093] L represents the effective length of the coil conductor that cuts the magnetic field lines (m);

[0094] I represents the instantaneous value of the current in the moving coil (A);

[0095] a represents the force constant of the exciter.

[0096] The system is a typical single-degree-of-freedom vibration model, and its principle block diagram is as follows Fig.16 As shown. The force F applied to the spring oscillator system by the exciter 1 The displacement x of the excitation rod is detected by laser displacement sensor 1, and the displacement output x of the valve is detected by laser displacement sensor 2. 1 , through mechanical analysis:

[0097]

[0098] Simplifying the Laplace transform, we can get the displacement x of the excitation rod to the displacement output x of the valve.1 The transfer function G(s):

[0099]

[0100] In the formula, k c =1.

[0101] Thus we can get:

[0102]

[0103] From the above formula, we can calculate the viscous friction coefficient B c With mass m, spring coefficient k and damping ratio ξ. If mass m and spring coefficient k are known, the damping ratio ξ can be obtained to obtain the viscous friction coefficient B c The damping ratio is obtained by calculating the damping ratio according to the amplitude-frequency characteristic curve.

[0104] For a single degree of freedom vibration system, we have:

[0105]

[0106] In the actual amplitude-frequency characteristic curve, we first need to set an initial measurement frequency, such as 1 Hz, to obtain the initial amplitude-frequency value, and then find the maximum resonant amplitude H of the amplitude-frequency characteristic from the amplitude-frequency curve. m and H of 0.707 m , thus obtaining f 2 、f 1 and f 0 , f 2 、f 1 and f 0 Substituting into equation (2) we can calculate the damping ratio ξ, and then substituting into equation (1) we can calculate the viscous friction coefficient B c .

[0107] S4. Experimental testing and data analysis to form data files.

[0108] According to the requirements of the test plan, the manufacturing of 27 valve carriers and tooling has been completed, and the friction test and viscous friction coefficient test of all carriers have been completed.

[0109] Friction test

[0110] Embodiment 1

[0111] Select 9Cr18 material

[0112] Gap: XXA-SY18 metering valve friction test data of 0.006mm~0.010mm are shown in Table 4~Table 6, and the relationship curves of static friction, dynamic friction and temperature are shown in Figure 17 to Figure 19 .

[0113] Table 4 Friction test data

[0114]

[0115]

[0116] Table 5 Friction test data

[0117]

[0118] Table 6 Friction test data

[0119]

[0120]

[0121] Embodiment 2

[0122] Gap: XXA-SY19 metering valve friction test data of 0.012mm ~ 0.018mm is shown in Table 7 ~ Table 8, static friction, dynamic friction and temperature relationship curve is shown in Figure 20-21 .

[0123] Table 7 Friction test data

[0124]

[0125] Table 8 Friction test data

[0126]

[0127]

[0128] Embodiment 3

[0129] Gap: XXA-SY20 metering valve friction test data of 0.018mm ~ 0.026mm is shown in Table 9 ~ Table 10, static friction, dynamic friction and temperature relationship curve is shown in Figure 22-23 .

[0130] Table 9 Friction test data

[0131]

[0132] Table 10 Friction test data

[0133]

[0134] It can be seen from the above curves that the dynamic friction and static friction of the metering valve of 9Cr18 material are affected by temperature. The higher the temperature, the greater the friction. Under the same material, the friction difference of the metering valve without gap is small, and there is overlap between the data.

[0135] Successively completed 9Cr18, 6061-T6, 4Cr 1 The friction force and viscous friction coefficient of valve carriers of three commonly used materials, 4Ni14W2Mo, and three types of valve clearances, 0.006-0.01, 0.012-0.018, and 0.018-0.026, totaling 27 times, were tested to form experimental test data, which provided data support for subsequent valve simulation.

[0136] Therefore, the present invention adopts the above-mentioned fuel metering valve friction force and viscous friction coefficient testing method to complete the friction force test and viscous friction coefficient test of metering valves with different materials and different gaps, and studies the physical properties of the metering valve, providing effective experimental data support for the later design optimization, modification, reliability evaluation, etc. of the product.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for testing the friction force and viscous friction coefficient of a fuel metering valve, characterized in that: The following steps are involved: S1. Select the test metering valve sample; S2. Design and manufacture of test tooling; S3. Preparation and issuance of test plans; S4. Conduct experimental testing and data analysis to form data files.

2. A method for testing the friction force and viscous friction coefficient of a fuel metering valve according to claim 1, characterized in that: In S1, the test measurement valve sample selection is completed by determining the sample valve shape, valve material, valve gap and valve quantity.

3. A method for testing the friction force and viscous friction coefficient of a fuel metering valve according to claim 2, characterized in that: In S1, the XX-12 metering valve assembly of the nozzle control device was selected as the carrier prototype; The valve materials include 9Cr18, 6061-T6 and 4Cr14Ni14W2Mo, and the surface of the valve materials is treated; The valve clearance includes three types: 0.006mm~0.01mm, 0.012mm~0.018mm, and 0.018mm~0.026mm; According to the valve material and valve clearance, nine types of valves including three valve materials 9Cr18, 6061-T6, 4Cr14Ni14W2Mo and three valve clearances of 0.006mm~0.01mm, 0.012mm~0.018mm, and 0.018mm~0.026mm were selected for testing.

4. A method for testing the friction force and viscous friction coefficient of a fuel metering valve according to claim 3, characterized in that: In S2, the test tooling is designed according to the sample valve dimensions in S1. Specifically, the test tooling is designed according to the dimensions of the test carrier XXA-12 metering valve assembly and the tester structure. After the test tooling design is completed, the tooling is manufactured.

5. A method for testing the friction force and viscous friction coefficient of a fuel metering valve according to claim 4, characterized in that: S3 specifically includes the following steps: S31. Determination of the test carrier of the metering valve assembly; S32, the valve assembly test carrier is drawn using UG software; S33. Process and manufacture metering valves according to test requirements; S34. Design and preparation of experimental plan.

6. A method for testing the friction force and viscous friction coefficient of a fuel metering valve according to claim 5, characterized in that: S34 specifically includes the following steps: S341. Soak the test carrier in oil. Keep the oil tank pressure-free during the test. S342. Determine the friction force and friction coefficient test data at different temperatures. Based on 20℃±3℃, test one set of data every time the temperature rises by 10℃. Test six sets of data for the friction force of each valve and three sets of data for the viscous friction coefficient. The highest test temperature is 150℃±3℃.

7. A method for testing the friction force and viscous friction coefficient of a fuel metering valve according to claim 6, characterized in that: In S4, the amplitude-frequency characteristic curve of the single-degree-of-freedom spring oscillator system is used to test the viscous damping of the valve, and the dynamic test method is used to test the viscous friction coefficient.

8. A method for testing the friction force and viscous friction coefficient of a fuel metering valve according to claim 7, characterized in that: The single-degree-of-freedom spring oscillator system includes a horizontally arranged three-dimensional manual displacement platform and a valve test assembly, on which an exciter-side laser displacement sensor and an exciter are arranged in sequence, a spring is arranged between the valve test assembly and the exciter, and a valve-side laser displacement sensor is arranged on the side of the valve test assembly away from the spring.

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