System and method for testing flow characteristics of magnetorheological damper

Abstract

The invention belongs to the technical field of shock absorber flow characteristic testing, and mainly relates to a magneto-rheological shock absorber flow characteristic testing system and a magneto-rheological shock absorber flow characteristic testing method.The magneto-rheological shock absorber flow characteristic testing system comprises a hydraulic testing cylinder, a hydraulic oil pump, a flow regulating valve and a reversing valve, the hydraulic test cylinder comprises a cylinder body, two end covers, a first floating piston, a second floating piston and a test piston, and the test piston is arranged between the first floating piston and the second floating piston; the two end covers are respectively provided with a first oil port and a second oil port, and the testing piston is provided with a throttling port. The testing piston is arranged in the hydraulic testing cylinder and connected into a hydraulic system, the pressure difference of the two sides of the testing piston is calculated, and the damping force of the corresponding shock absorber can be calculated through formula conversion.

Description

Technical Field

[0001] The invention belongs to the technical field of flow characteristic testing of shock absorbers, and mainly relates to a flow characteristic testing system and a testing method for a magnetorheological shock absorber. Background Art

[0002] The single-tube magnetorheological fluid shock absorber is a shock absorber that uses the property of magnetorheological fluid to rapidly change viscosity under the action of a magnetic field to achieve damping adjustment. The flow characteristics of the magnetorheological shock absorber are mainly reflected in its ability to achieve rapid, continuous and reversible control of the damping force by adjusting the rheological properties of the magnetorheological fluid according to different working conditions and requirements. Magnetorheological fluid is a liquid containing tiny magnetic particles. In the absence of a magnetic field, these particles are randomly distributed and the liquid exhibits a low viscosity state. When a magnetic field is applied, the magnetic particles will quickly form a chain structure, causing the viscosity of the liquid to increase dramatically, thereby changing its damping characteristics. The single-tube magnetorheological fluid shock absorber adjusts the viscosity of the liquid by controlling the magnetic field strength, thereby achieving rapid and adjustable damping force.

[0003] The working principle of the single-tube magnetorheological shock absorber involves complex physical processes, including multiphase coupling and rheological effects. The behavior of this multiphase system is difficult to accurately describe with traditional fluid dynamics models. The viscosity of the magnetorheological fluid changes with the intensity of the magnetic field. This nonlinear rheological behavior increases the complexity of the simulation model. It is difficult to obtain a relatively accurate result of the damping force of the magnetorheological shock absorber through software simulation, which brings great inconvenience to the debugging and calibration of the magnetorheological shock absorber. Without relatively accurate quantitative impact data of various parameters, a series of debugging shock absorbers with different parameters will have to be designed and manufactured during project development to conduct a large number of experiments on the test bench, so as to determine the theoretical influence of each parameter on the force value through a large number of result comparisons.

[0004] In the prior art, calculations are usually performed through simulations, but they are all in the research stage, and the calculated force values ​​are not accurate, making it difficult to accurately calculate the damping force of the single-tube magnetorheological shock absorber. Summary of the invention

[0005] The present invention provides a flow characteristic testing system and a testing method for a magnetorheological damper, so as to solve the problem in the prior art that it is difficult to accurately calculate the damping force of a single-tube magnetorheological damper due to multiphase coupling and rheological effect of the magnetorheological damper.

[0006] To solve the above problems, the present invention adopts the following technical solutions:

[0007] The flow characteristic test system of a magnetorheological shock absorber comprises a hydraulic test cylinder and a hydraulic oil pump connected through a hydraulic circuit, and a flow regulating valve and a reversing valve arranged on the hydraulic circuit; the hydraulic test cylinder comprises a cylinder body, a first end cover, a second end cover, a first floating piston, a second floating piston and a test piston, the test piston is arranged between the first floating piston and the second floating piston, and is used to simulate the damping piston of the magnetorheological shock absorber; a first hydraulic oil chamber is formed between the first floating piston, the first end cover and the cylinder body, a second hydraulic oil chamber is formed between the second floating piston, the second end cover and the cylinder body, and a second hydraulic oil chamber is formed between the test piston, the first floating piston and the cylinder body A first magnetorheological fluid chamber is formed, and a second magnetorheological fluid chamber is formed between the test piston, the second floating piston and the cylinder body; the first end cover is provided with a first oil port connected to the first hydraulic oil chamber, and the second end cover is provided with a second oil port connected to the second hydraulic oil chamber; the test piston is provided with a throttle port connected to the first magnetorheological fluid chamber and the second magnetorheological fluid chamber; the hydraulic oil circuit connected to the first oil port and the hydraulic oil circuit connected to the second oil port are both provided with pressure detection devices, and the hydraulic oil circuit connected to the first oil port is also provided with a flow meter; the first floating piston and the second floating piston are both movably assembled in the cylinder body along the same direction.

[0008] Beneficial effects of the magnetorheological shock absorber flow characteristic test system of the present invention: After the test piston is installed in the hydraulic test cylinder and connected to the hydraulic system, the pressure difference on both sides of the test piston is measured, and then the output damping force of the shock absorber is obtained by calculation. The present invention adopts a method combining engineering testing and theoretical calculation to obtain the quantitative influence of different parameters on the test piston on the damping force output, so as to solve the problem of difficulty in accurately calculating the damping force caused by the multi-phase coupling and rheological effect of the magnetorheological shock absorber.

[0009] Furthermore, a fixing piece is provided at a middle position of the cylinder body, a mounting opening is provided on the fixing piece, and the test piston is assembled at the mounting opening in a detachable clamping manner.

[0010] Beneficial effect: It is convenient to install and disassemble the test piston.

[0011] Furthermore, the first floating piston and the second floating piston are both provided with weight-reducing grooves, and the weight-reducing grooves on the first floating piston and the second floating piston face the first end cover and the second end cover respectively.

[0012] Beneficial effects: The first floating piston and the second floating piston are both provided with weight-reducing grooves, which reduce the weight of the floating pistons, facilitate transportation, and save materials.

[0013] Furthermore, the reversing valve is a three-position four-way electromagnetic reversing valve.

[0014] Furthermore, the pressure detection device is a pressure gauge.

[0015] Beneficial effects: The pressure gauge can be directly read and is easy to use. In addition, the pressure gauge does not contact the magnetorheological fluid, which can ensure the accuracy and life of the pressure gauge.

[0016] The method for testing the flow characteristics of a magnetorheological damper is carried out using the magnetorheological damper flow characteristics testing system, and comprises the following steps:

[0017] Step 1: Connect the hydraulic test cylinder to the hydraulic system and set the required flow rate V 1 , according to Q = V 1 A 0 Calculate the required flow rate Q, A of the hydraulic system 0 is the effective area of ​​the test piston; when the test piston is not installed and the hydraulic system is running in a steady state, the pressure difference between the first oil port and the second oil port of the hydraulic test cylinder is measured, and the pressure difference is recorded as P 标 ;

[0018] Step 2: Install the test piston in the hydraulic test cylinder, connect the test piston to a DC power supply, input the current to be calibrated, and record the calibrated current as I. Given the hydraulic oil flow Q in step 1, and after the hydraulic system reaches a steady state again, measure the pressure difference between the first and second oil ports of the hydraulic test cylinder, and record the pressure difference as P. 测 , the pressure drop on both sides of the test piston is P; according to P = P 测 -P 标 , calculate the pressure drop on both sides of the test piston;

[0019] Step 3: According to F=PA 0 Calculate the output damping force when the calibration current is I, where F is the output damping force of the shock absorber. By inputting different calibration speeds V 1 Different calibration speeds V 1 The damping force of the shock absorber under the condition of 1 Relationship curve;

[0020] Step 4: Repeat the test at different calibration currents I and obtain F = f(I, V 1 )Relationship curve;

[0021] Step 5, analyzing the flow characteristics of the single-tube magnetorheological shock absorber according to the relationship curves obtained in step 3 and step 4;

[0022] Step 6: Replace the test piston with different parameters or different magnetorheological fluids, and repeat the above steps 1 to 5 to obtain the quantitative effects of the test piston with different parameters or different magnetorheological fluids on the output damping force of the single-tube magnetorheological shock absorber.

[0023] Furthermore, the test piston in the hydraulic test cylinder has the same parameters as the damping piston in the single-tube magnetorheological shock absorber.

[0024] Beneficial effect: The test piston in the hydraulic test cylinder has the same parameters as the damping piston in the single-tube magnetorheological shock absorber, ensuring that the calculated value is the pressure drop P in the single-tube magnetorheological shock absorber.

[0025] Furthermore, before the test, a cooling water jacket is provided outside the cylinder barrel of the hydraulic test cylinder.

[0026] In summary, the method for testing the flow characteristics of a magnetorheological shock absorber of the present invention is to install the test piston into a hydraulic test cylinder and connect it to a hydraulic system, and then calibrate the speed V 1 The corresponding flow rate Q in the shock absorber at the speed is calculated, and then the external test system gives this flow rate Q to the test cylinder. The pressure drop P at both ends of the test piston at this flow rate is measured experimentally. Since there is only this one throttle port in the single-tube magnetorheological shock absorber that produces a pressure drop, the damping force output of the shock absorber corresponding to this pressure drop can be obtained through a formula; repeating the above process under different calibration currents can obtain the damping force output by the shock absorber at different speeds and currents, that is, the flow characteristics (PQ curve relationship) at both ends of the test piston are experimentally measured under different currents, and the damping characteristics of the shock absorber equipped with this test piston can be obtained.

[0027] Therefore, the present invention adopts a method combining engineering test and theoretical calculation to obtain the relationship curve between the damping force output by the shock absorber and the speed and current. A relatively simple engineering test method is used to replace the simulation calculation with complex process and large result deviation to solve the problem of difficulty in accurately calculating the damping force caused by the multi-phase coupling and rheological effect of the magnetorheological shock absorber. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0029] Figure 1 It is a structural schematic diagram of the hydraulic test cylinder in the present invention;

[0030] Figure 2 It is a structural schematic diagram of a single-tube magnetorheological shock absorber;

[0031] Figure 3 It is a schematic diagram of the flow characteristic testing system of the magnetorheological damper in the present invention.

[0032] Description of reference numerals:

[0033] 1. Piston rod; 2. Damping piston; 3. Through hole; 4. Cylinder barrel; 5. Floating piston; 6. Hydraulic test cylinder; 7. First pressure gauge; 8. Flow meter; 9. Reversing valve; 10. Flow regulating valve; 11. Overflow valve; 12. Hydraulic oil pump; 13. First end cover; 14. Second end cover; 15. First floating piston; 16. Second floating piston; 17. Test piston; 18. Throttle port; 19. Weight reduction groove; 20. Fixing piece; 21. First chamber; 22. Second chamber; 23. Third chamber; 24. First hydraulic oil chamber; 25. First magnetorheological fluid chamber; 26. Second magnetorheological fluid chamber; 27. Second hydraulic oil chamber; 28. Cylinder body; 29. ​​First oil port; 30. Second oil port; 31. Second pressure gauge. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0035] Various non-limiting embodiments of the present invention are described in detail below. Any number of elements in the accompanying drawings is for illustration and not for limitation, and any naming is only for distinction and does not have any limiting meaning. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0036] The flow characteristic test system of the magnetorheological damper of the present invention is used to simulate the working environment of the damping piston 2 in the single-tube magnetorheological damper. Figure 2 As shown, it includes a cylinder 4, a floating piston 5 located in the cylinder 4, a damping piston 2 located in the cylinder 4 and a piston rod 1 connected to the damping piston 2, the damping piston 2 is provided with two through holes 3, a first chamber 21 is formed between the damping piston 2 and the cylinder 4, a second chamber 22 is formed between the damping piston 2 and the floating piston 5, and a third chamber 23 is formed between the floating piston 5 and the cylinder 4, the first chamber 21 and the second chamber 22 are filled with magnetorheological fluid, and the third chamber 23 is filled with nitrogen.

[0037] The piston static equilibrium equation is established with the damping piston 2 as an independent body:

[0038] F+P 2 A P =P 1 (A P -A r )(1);

[0039] By moving the terms, we get: F = (P 1 -P 2 )(A P -A r )-P 2 A r (2);

[0040] The magnetorheological fluid and nitrogen are separated only by the floating piston 5, and P 2 Equal to P 3 , note P 2 =P 3 (3);

[0041] Substituting the above formula (3) into formula (2) yields: F = (P 1 -P 2 )(A P -A r )-P 3 A r (4);

[0042] definition:

[0043] P=P 1 -P 2 (5);

[0044] A 0 =A P -A r (6);

[0045] F a =P 3 A r (7);

[0046] When the piston rod 1 is stretched, P 1 >P 2 ,F=PA 0 -F a (8);

[0047] When the piston rod 1 is compressed, P 1 <P 2 , -F=-PA 0 -F a , that is, F = PA 0 +F a (9), the direction of F is vertically downward.

[0048] Gas force F a The floating piston 5 changes very little in speed, and its value is relatively small relative to the shock absorber throttling pressure PA 0 It is also small. Most shock absorber test benches will calculate the data after removing the gas force. In this case, this item is ignored for the sake of simplicity, that is, F = PA 0 (10).

[0049] The meanings of the various parameters in formula (1) to formula (10) are as follows:

[0050] F- output damping force of the monotube magnetorheological shock absorber;

[0051] F a - Gas force;

[0052] P-pressure difference at both ends of floating piston 5;

[0053] P 1 - the pressure in the first chamber 21;

[0054] P 2 - the pressure in the second chamber 22;

[0055] P 3 - the pressure in the third chamber 23;

[0056] A P - the area of ​​the floating piston 5;

[0057] A r - Area of ​​piston rod 1;

[0058] A 0 - The effective area of ​​the floating piston 5.

[0059] A conclusion can be drawn from the above formulas (1) to (10): the theoretical output damping force of the shock absorber can be calculated by calculating the pressure difference at both ends of the damping piston 2.

[0060] Therefore, the present application provides a magnetorheological shock absorber flow characteristic test system. The test piston 17 is installed in a detachable hydraulic test cylinder 6 and connected to the hydraulic system, and the pressure difference at both ends of the test piston 17 is experimentally measured to calculate the theoretical output damping force of the shock absorber equipped with a damping piston 2 with the same parameters as the test piston.

[0061] like Figure 1 and Figure 3 As shown, the magnetorheological shock absorber flow characteristic test system includes a hydraulic test cylinder 6, a hydraulic circuit, a pressure gauge, a reversing valve 9, a hydraulic oil pump 12, a flow regulating valve 10 and a relief valve 11.

[0062] like Figure 1As shown, the hydraulic test cylinder 6 includes a cylinder body 28, a first end cover 13, a second end cover 14, a first floating piston 15, a second floating piston 16, a test piston 17 and a cylindrical fixing member 20. The fixing member 20 is located in the middle of the cylinder body 28. The outer diameter of the fixing member 20 is the same as the outer wall diameter of the cylinder body 28 and the two are coaxial. A mounting port is provided in the fixing member 20, and the test piston 17 is assembled at the mounting port in a detachable snap-fit ​​manner to simulate the damping piston 2 in a single-tube magnetorheological shock absorber. The inner diameter of the test piston 17 is coaxial with the inner diameter of the fixing member 20, and the fixing member 20 has the same thickness as the test piston 17. The test piston 17 is also provided with a throttle port 18 for the flow of magnetorheological fluid.

[0063] like Figure 1 As shown, the first end cover 13 and the second end cover 14 are respectively arranged at the two ends of the cylinder body 28, and two oil ports are provided, namely the first oil port 29 and the second oil port 30, both of which are located on the two end covers respectively.

[0064] like Figure 1 As shown, the first floating piston 15 and the second floating piston 16 are symmetrically arranged inside the cylinder body 28 about the fixing part 20, the diameter of the floating piston is the same as the diameter of the inner wall of the cylinder body 28, and the first floating piston 15 and the second floating piston 16 are provided with weight-reducing grooves 19, and the two weight-reducing grooves 19 are directed toward the first end cover 13 and the second end cover 14 respectively, and the light weight makes the floating piston easier to install and disassemble.

[0065] like Figure 1 As shown, a first hydraulic oil chamber 24 is formed between the first floating piston 15 and the first end cover 13 and the cylinder body 28, a second hydraulic oil chamber 27 is formed between the second floating piston 16, the second end cover 14 and the cylinder body 28, a first magnetorheological fluid chamber 25 is formed between the test piston 17, the first floating piston 15 and the cylinder body 28, and a second magnetorheological fluid chamber 26 is formed between the test piston 17, the second floating piston 16 and the cylinder body 28. The first hydraulic oil chamber 24 and the second hydraulic oil chamber 27 are filled with hydraulic oil and are connected to the hydraulic circuit through corresponding oil ports. The first magnetorheological fluid chamber 25 and the second magnetorheological fluid chamber 26 are filled with magnetorheological fluid and the two chambers are connected through the throttle port 18. Since the magnetorheological fluid contains iron powder particles with a particle size of micrometers, it will cause damage to various components in the hydraulic oil circuit. The present invention uses the first floating piston 15 and the second floating piston 16 to separate the magnetorheological fluid and the hydraulic oil to prevent the magnetorheological fluid from contaminating the external hydraulic system oil circuit.

[0066] like Figure 1 and Figure 3As shown, two pressure gauges are provided, namely a first pressure gauge 7 and a second pressure gauge 31. Since both ends of the test piston 17 are sealed magnetorheological fluid, a general pressure gauge cannot meet the measurement requirements and an additional sealing structure and a sealing sensor circuit are required, which greatly reduces the economic efficiency of the test bench. The first pressure gauge 7 is arranged in the hydraulic circuit near the first oil port 29, and the second pressure gauge 31 is arranged in the hydraulic circuit near the second oil port 30, which are used to test the pressure at both ends of the hydraulic test cylinder 6. The two pressure gauges are arranged in the hydraulic circuit so that the pressure gauges do not contact the magnetorheological fluid, thereby ensuring the accuracy and life of the pressure gauges. When the test piston 17 is not installed, the total pressure difference of the oil port, the floating piston and the shrinkage and expansion of the cylinder body 28 at different flow rates is calibrated (the system pressure difference without the test piston 17), that is, the difference between the values ​​read by the two pressure gauges. After the test piston 17 is installed, the pressure difference measured is the system pressure difference plus the pressure difference at both ends of the piston, that is, the difference between the values ​​read by the two pressure gauges. The pressure difference at both ends of the test piston 17 can be measured by subtracting the difference between the pressure gauges when the test piston 17 is installed and when the test piston 17 is not installed.

[0067] like Figure 3 As shown, the reversing valve 9 is a three-position four-way solenoid reversing valve 9, which is located in the hydraulic circuit and is used to adjust the flow direction of the hydraulic oil in the hydraulic circuit. The three-position four-way solenoid reversing valve 9 is a prior art and will not be described in detail here. The three-position four-way solenoid reversing valve 9 has a short action response time and can quickly switch the flow direction of the hydraulic oil, which is convenient for actually controlling the flow direction of the hydraulic oil in the hydraulic circuit.

[0068] like Figure 3 As shown, in the hydraulic circuit, a flow meter 8 is provided between the first pressure gauge 7 and the reversing valve 9. The flow meter 8 is used to monitor the flow in the actual oil circuit. The flow meter 8 is a prior art and will not be described in detail here.

[0069] like Figure 3 As shown, the hydraulic oil pump 12 provides power to the hydraulic system, converts mechanical energy into hydraulic energy, and drives various actuators in the hydraulic system to operate. The hydraulic oil pump 12 is a prior art and will not be described in detail here.

[0070] like Figure 3 As shown, the relief valve 11 controls the pressure of the system to ensure that the system operates within a safe pressure range. The relief valve 11 is a prior art and will not be described in detail here.

[0071] like Figure 3 As shown, the flow regulating valve 10 can accurately regulate the flow of the fluid passing through the valve, thereby controlling the flow rate of the hydraulic oil. The flow regulating valve 10 is a prior art and will not be described in detail herein.

[0072] The present invention uses a hydraulic test cylinder 6 that can simulate the working environment of the damping piston 2 in a single-tube magnetorheological shock absorber. After the test piston 17 is installed in the hydraulic test cylinder 6 and connected to the hydraulic system, the pressure difference on both sides of the test piston 17 is measured to calculate the force on the test piston 17, and then the output damping force of the shock absorber is obtained. The present invention uses a method combining engineering testing and theoretical calculation to obtain the quantitative influence of different parameters on the test piston 17 on the damping force output, so as to solve the problem that it is difficult to accurately calculate the output damping force of the single-tube magnetorheological shock absorber due to the multi-phase coupling and rheological effect of the magnetorheological shock absorber.

[0073] The method for testing flow characteristics of a magnetorheological damper comprises the following steps:

[0074] Step 1: Connect the hydraulic test cylinder 6 that can simulate the working environment of the damping piston 2 in the single-tube magnetorheological shock absorber to the hydraulic system, and set the hydraulic oil flow rate V 1 , according to Q = V 1 A 0 Calculate the given flow Q, A of the hydraulic system 0 is the effective area of ​​the test piston 17; when the test piston 17 is not installed and the hydraulic system is in steady state operation, the pressure difference between the first oil port 29 and the second oil port 30 of the hydraulic test cylinder 6 is measured, and the pressure difference is recorded as P mark;

[0075] Step 2, install the test piston 17 in the hydraulic test cylinder 6, connect the test piston 17 to a DC power supply, input the current to be calibrated, and record the calibrated current as I. Given the hydraulic oil volume Q in step 1, and after the hydraulic system reaches a steady state again, measure the pressure difference between the first oil port 29 and the second oil port 30 of the hydraulic test cylinder 6, and record the pressure difference as Ptest, and the pressure drop on both sides of the test piston 17 as P; according to P=Ptest-Pstandard, calculate the pressure drop on both sides of the test piston 17;

[0076] Step 3: According to F=PA 0 The output damping force under the condition of the calibration current I is calculated, where F is the output damping force of the test piston 17, and by inputting different calibration speeds V 1 Different calibration speeds V 1 The output damping force of the test piston 17 under the condition of 1 Relationship curve;

[0077] Step 4: Repeat the test at different calibration currents I and obtain F = f(I, V 1 )Relationship curve;

[0078] Step 5, analyzing the flow characteristics of the single-tube magnetorheological shock absorber according to the relationship curves obtained in step 3 and step 4;

[0079] Step 6: Replace the test piston 17 with different parameters or different magnetorheological fluids, and repeat the above steps 1 to 5 to obtain the quantitative effects of the test piston 17 with different parameters or different magnetorheological fluids on the output damping force of the single-tube magnetorheological shock absorber.

[0080] Before the test, a cooling water jacket is provided outside the cylinder body 28 of the hydraulic test cylinder 6 to prevent the temperature of the magnetorheological fluid in the cylinder body 28 from changing too much.

[0081] Due to the incompressibility of the fluid, Q = A 0 V 1 =A 2 V 2 , here A 0 is the effective area of ​​the test piston 17, V 1 is the fluidity of a given hydraulic oil, A 2 is the inner diameter area of ​​the cylinder 28, V 2 is the floating piston speed, the inner diameter area of ​​the cylinder 28 is equal to the floating piston area, that is, the floating piston area is A 2 When the shock absorber needs to be calibrated at a higher speed, the speeds of the first floating piston and the second floating piston increase accordingly. Since it takes a certain amount of time for the hydraulic system to reach a steady state after adjustment, the stroke of the floating piston will increase sharply. The fluidity of the hydraulic oil can be reduced by increasing the inner diameter R of the hydraulic test cylinder 6. According to the maximum hydraulic oil flow rate V 1MAX , determine the time T required for the hydraulic system to reach stability, the time T required for the hydraulic system to reach stability is a constant value, select a hydraulic test cylinder 6 with an appropriate inner diameter to ensure that the one-way stroke S>V 1MAX T, S is the distance from the test piston to the first floating piston and the second floating piston; if S is too long, S can be reduced by increasing the inner diameter of the cylinder body to avoid the overall length of the hydraulic test cylinder 6 being too long.

[0082] In summary, the method for testing the flow characteristics of a magnetorheological shock absorber of the present invention is to install the test piston into a hydraulic test cylinder and connect it to a hydraulic system, and then calibrate the speed V 1 The corresponding flow rate Q in the shock absorber at this speed is calculated, and then the external test system gives this flow rate Q to the test cylinder. The pressure drop P at both ends of the test piston at this flow rate is measured experimentally. Since there is only this one throttle port in the single-tube magnetorheological shock absorber that produces a pressure drop, the damping force output of the shock absorber corresponding to this pressure drop can be obtained through the formula; repeating the above process under different calibration currents can obtain the damping force output by the shock absorber at different speeds and currents, that is, the flow characteristics (PQ curve relationship) at both ends of the test piston are experimentally measured under different currents, and the damping characteristics of the shock absorber equipped with this test piston can be obtained.

[0083] Therefore, the present invention adopts a method combining engineering test and theoretical calculation to obtain the relationship curve between the damping force output by the shock absorber and the speed and current. A relatively simple engineering test method is used to replace the simulation calculation with complex process and large result deviation to solve the problem of difficulty in accurately calculating the damping force caused by the multi-phase coupling and rheological effect of the magnetorheological shock absorber.

[0084] The calculations and tests in this example are all based on the premise that the hydraulic system is operating in a steady state.

Claims

1. Magnetorheological damper flow characteristic test system, characterized in that: It includes a hydraulic test cylinder and a hydraulic oil pump connected through a hydraulic circuit, and a flow regulating valve and a reversing valve arranged on the hydraulic circuit; The hydraulic test cylinder comprises a cylinder body, a first end cover, a second end cover, a first floating piston, a second floating piston and a test piston. The test piston is arranged between the first floating piston and the second floating piston and is used to simulate the damping piston of the magnetorheological shock absorber. A first hydraulic oil chamber is formed between the first floating piston, the first end cover and the cylinder body, a second hydraulic oil chamber is formed between the second floating piston, the second end cover and the cylinder body, a first magnetorheological fluid chamber is formed between the test piston, the first floating piston and the cylinder body, and a second magnetorheological fluid chamber is formed between the test piston, the second floating piston and the cylinder body. The first end cover is provided with a first oil port communicating with the first hydraulic oil chamber, and the second end cover is provided with a second oil port communicating with the second hydraulic oil chamber; the test piston is provided with a throttle port communicating with the first magnetorheological fluid chamber and the second magnetorheological fluid chamber; the hydraulic oil circuit connected to the first oil port and the hydraulic oil circuit connected to the second oil port are both provided with a pressure detection device, and the hydraulic oil circuit connected to the first oil port is also provided with a flow meter; The first floating piston and the second floating piston are both movably assembled in the cylinder body along the same direction.

2. The magnetorheological damper flow characteristic testing system according to claim 1, characterized in that: A fixing piece is provided at the middle position of the cylinder body, a mounting opening is provided on the fixing piece, and the test piston is assembled at the mounting opening in a detachable clamping manner.

3. The magnetorheological damper flow characteristic testing system according to claim 1, characterized in that: The first floating piston and the second floating piston are both provided with weight-reducing grooves, and the weight-reducing grooves on the first floating piston and the second floating piston face the first end cover and the second end cover respectively.

4. The magnetorheological damper flow characteristic testing system according to claim 1, characterized in that: The reversing valve is a three-position four-way electromagnetic reversing valve.

5. The magnetorheological damper flow characteristic testing system according to any one of claims 1 to 4, characterized in that: The pressure detection device is a pressure gauge.

6. Magnetorheological damper flow characteristics test method, characterized in that: The magnetorheological damper flow characteristic testing system according to any one of claims 1 to 5 is used for testing, comprising the following steps: Step 1: Connect the hydraulic test cylinder that can simulate the working environment of the floating piston in the single-tube magnetorheological shock absorber to the hydraulic system. Given the hydraulic oil flow rate V1, calculate the flow rate Q given by the hydraulic system according to Q=V1A0, where A0 is the effective area of ​​the test piston. When the test piston is not installed and the hydraulic system is running in a steady state, measure the pressure difference between the first oil port and the second oil port of the hydraulic test cylinder, and record the pressure difference as P 标 ; Step 2: Install the test piston in the hydraulic test cylinder, connect the test piston to a DC power supply, input the current to be calibrated, record the calibrated current as I, give the hydraulic oil volume Q in step 1, and measure the pressure difference between the first and second oil ports of the hydraulic test cylinder after the hydraulic system reaches a steady state again, record the pressure difference as P 测 , the pressure drop on both sides of the test piston is P; according to P = P 测 -P 标 , calculate the pressure drop on both sides of the test piston; Step 3: Calculate the output damping force when the calibration current is I according to F=PA0, where F is the output damping force of the shock absorber, and obtain the output damping force of the shock absorber under different calibration speeds V1 by inputting different calibration speeds V1, and obtain the F-V1 relationship curve; Step 4: Repeat the test under different calibration currents I to obtain the F=f(I, V1) relationship curve; Step 5, analyzing the flow characteristics of the single-tube magnetorheological shock absorber according to the relationship curves obtained in step 3 and step 4; Step 6: Replace the test piston with different parameters or different magnetorheological fluids, and repeat the above steps 1 to 5 to obtain the quantitative effects of the test piston with different parameters or different magnetorheological fluids on the output damping force of the single-tube magnetorheological shock absorber.

7. The method for testing flow characteristics of a magnetorheological damper according to claim 6, characterized in that: The test piston in the hydraulic test cylinder has the same parameters as the damping piston in the single-tube magnetorheological shock absorber.

8. The method for testing flow characteristics of a magnetorheological damper according to claim 6, characterized in that: Before testing, a cooling water jacket is installed outside the cylinder barrel of the hydraulic test cylinder.

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