A fatigue test device and test method for a pantograph head suspension system

Abstract

The present invention provides a fatigue test device and test method for a pantograph head suspension system, which includes a specimen support for adjusting and fixing a specimen. A counterweight mechanism detachably connected to the specimen is arranged on one side of the specimen support. A striking mechanism is arranged on the side of the counterweight mechanism away from the specimen support. The striking mechanism is rotatably connected to a motor, and the motor is adjustably connected to a test bench. A speed regulator is connected to the motor. An optical fiber strain sensor and an optical fiber acceleration sensor are arranged on the specimen. After being connected to an optical fiber signal demodulator, the optical fiber strain sensor and the optical fiber acceleration sensor are connected to a host computer. The problems of high cost and large data acquisition risk in the fatigue test of the pantograph head suspension system in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of pantograph fatigue testing, and particularly to a fatigue testing device and testing method for a pantograph head suspension system. Background Art

[0002] A electric locomotive obtains electric energy from an overhead catenary through a pantograph. The pantograph mainly consists of a slide plate, a pantograph head suspension structure, an upper frame, a balance rod, a lower frame, a pull rod, a chassis, etc. Common pantograph head suspension structures mainly include rubber spring suspension, diagonal spring suspension, leaf spring suspension, and spring cylinder suspension. During the normal running of the vehicle, there are impact vibrations between the pantograph and the overhead catenary. Under the condition of a rigid overhead catenary, the impact force between the pantograph head and the rigid overhead catenary is large, and the maximum acceleration of the pantograph head can even reach 50g. Since the overhead catenary is rigid, it is difficult to dissipate the impact force between the pantograph and the catenary. Such a huge impact force is basically absorbed by the pantograph, thus greatly accelerating the fatigue of the pantograph and reducing its service life.

[0003] In recent years, high-speed railways have spread worldwide, and the pantograph-catenary current collection method has become the only truly used current collection method. With the increase in speed, the expansion of the use range, and the complication of service conditions, higher requirements are put forward for the design of each component on the pantograph, and the research on the fatigue problem of its suspension components has also become a topic of concern.

[0004] However, due to the characteristics of the long cycle and relatively complex working conditions of the fatigue problem itself, the existing researchers mainly conduct fatigue tests on the suspension components through actual line tests and collect relevant data of the components in actual service. However, it is too costly to conduct relevant research purely through line tests, and there are relatively large safety risks if only collecting data from the pantograph during actual operation. Summary of the Invention

[0005] Aiming at the above problems in the prior art, the present invention provides a fatigue testing device and testing method for a pantograph head suspension system, which solves the problems of high cost and large data collection risk in the fatigue test of the pantograph head suspension system in the prior art.

[0006] In order to achieve the above invention purpose, the technical solution adopted by the present invention is as follows:

[0007] Provided is a fatigue test device for a pantograph head suspension system, which includes a specimen support for adjustably fixing a specimen. A counterweight mechanism detachably connected to the specimen is arranged on one side of the specimen support. A striking mechanism is arranged on the side of the counterweight mechanism away from the specimen support. The striking mechanism is rotatably connected to a motor, and the motor is adjustably connected to a test bench. A speed regulator is connected to the motor. A fiber optic strain sensor and a fiber optic acceleration sensor are arranged on the specimen. After being connected to a fiber optic signal demodulator, the fiber optic strain sensor and the fiber optic acceleration sensor are connected to a host computer.

[0008] A method for conducting a test using the above-mentioned fatigue test device for a pantograph head suspension system includes:

[0009] Step 1: Install the specimen on the specimen support, and connect the counterweight mechanism, the fiber optic strain sensor, and the fiber optic acceleration sensor to the specimen.

[0010] Step 2: Calibrate the measurement accuracies of the fiber optic strain sensor and the fiber optic acceleration sensor.

[0011] Step 3: Adjust the height of the specimen on the specimen support, make the axis of the specimen parallel to the horizontal plane with the aid of a level, and adjust the installation position of the motor support on the test bench to adjust the relative positions of the first striking block and the second striking block and the counterweight block.

[0012] Step 4: Fully coat the first striking block and the second striking block with a marking agent, start the motor and rotate it at a speed of 30 - 35 revolutions per minute, so that the first striking block and the second striking block respectively strike the counterweight block once.

[0013] Step 5: Observe the shape and size of the impact marks left by the marking agent on the counterweight block, and judge whether the length of the impact marks is not less than 80% of the axial length of the first striking block and the angle with the horizontal line is not greater than 3°.

[0014] If so, the installation is qualified, and proceed to Step 6.

[0015] If not, the installation is unqualified. After adjusting the horizontal adjustment mechanism on the motor support, return to Step 4 until the installation is qualified.

[0016] Step 6: According to the working condition requirements, use the speed regulator to adjust the rotation speed of the motor to obtain different striking frequencies and striking forces for the fatigue test, and obtain the load data corresponding to the motor speed through the feedback of the fiber optic strain sensor and the fiber optic acceleration sensor and store it in the host computer.

[0017] The beneficial effects of the present invention are as follows: The weight mechanism connected to the test piece can simulate the static load received by the pantograph head suspension system under actual working conditions. The impact of the striking mechanism driven by the motor on the weight mechanism can simulate the impact load in actual working conditions. The motor can achieve precise and stepless change of the motor speed through the speed regulator, so as to achieve stepless adjustment of the magnitude of the impact load. The test piece is provided with a fiber optic strain sensor and a fiber optic acceleration sensor, which can feedback the load impact load received by the test piece to the upper computer in real time, so as to simulate the accelerated fatigue process of the pantograph head suspension system from normal to damaged under different impact loads.

[0018] The entire test device has a simple structure, an intuitive loading method, and effective and reliable experimental results. It can provide guiding experimental data for determining the service life of the pantograph head suspension system on the line, reduce the data acquisition cost, and improve safety.

[0019] In the test method, the spirit level can ensure the levelness of the test piece installed on the test piece support, so as to ensure the horizontal axis of the cylindrical weight block, which can reduce the operation difficulty of adjusting the striking block to be parallel to the axis of the weight block; both the striking block and the struck weight block are cylindrical structures. During impact, as long as the axes are parallel and the impact location is on the outer cylindrical surface, the impact location will always be the tangent of the two outer cylindrical surfaces, which is beneficial to ensuring that the impact force and method of the striking block on the weight block are consistent at the same motor speed each time, and can improve the effectiveness of the test data. Description of the Drawings

[0020] Figure 1 It is a three-dimensional structural schematic diagram of a fatigue test device for a pantograph head suspension system.

[0021] Figure 2 It is Figure 1 The three-dimensional structural schematic diagram of the test piece clamp in

[0022] Wherein, 1. Test piece support; 11. Test piece clamp; 111. Pipe clamp; 112. Tightening adjustment mechanism; 113. Connecting lug; 12. Mounting plate; 121. Slotted hole; 13. Spirit level; 2. Weight mechanism; 21. Connecting rod; 22. Weight block; 3. Striking mechanism; 31. First connecting spoke plate; 32. First striking block; 33. Second striking block; 34. Intermediate connecting plate; 4. Motor; 5. Test bench; 6. Speed regulator; 7. Fiber optic strain sensor; 8. Fiber optic acceleration sensor; 9. Motor support; 91. Slotted hole; 92. Horizontal adjustment mechanism; 10. Test piece; 101. Second spoke plate. Detailed Embodiments

[0023] The specific embodiments of the present invention will be described below to facilitate those skilled in the art of the present technology to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of the present technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present invention are within the scope of protection.

[0024] As Figure 1 shown, the fatigue test device for the pantograph head suspension system includes a specimen support 1 for adjustably fixing a specimen 10. The specimen 10 refers to the spring box of the pantograph head suspension system for each test. A counterweight mechanism 2 detachably connected to the specimen 10 is provided on one side of the specimen support 1. A striking mechanism 3 is provided on the side of the counterweight mechanism 2 away from the specimen support 1. The striking mechanism 3 is rotatably connected to a motor 4. The motor 4 is adjustably connected to a test bench 5. A speed regulator 6 is connected to the motor 4. A fiber optic strain sensor 7 and a fiber optic acceleration sensor 8 are provided on the specimen 10. After being connected to a fiber optic signal demodulator, the fiber optic strain sensor 7 and the fiber optic acceleration sensor 8 are connected to a host computer.

[0025] The specimen support 1 detachably fixes the specimen 10 through a specimen clamp 11. The specimen clamp 11 includes a pipe clamp 111. An elasticity adjusting mechanism 112 for adjusting the clamping tightness is provided on the pipe clamp 111. The pipe clamp 111 is used to clamp the outer cylindrical surface of the specimen 10. The elasticity adjusting mechanism 112 includes two spaced elastic pieces connected by bolts. Tightening the bolts can make the pipe clamp 111 clamp tightly, and loosening the bolts makes the pipe clamp 111 loosen, so that the pipe clamp 111 can clamp pantograph head suspension systems of various specifications for testing.

[0026] A spirit level 13 is provided on the specimen clamp 11. The spirit level is preferably a bubble level, which has a light structure and is easy to use. Two connecting lugs 113 are symmetrically provided on the pipe clamp 111. The two connecting lugs 113 are distributed vertically. The connecting lugs 113 have bolt holes and are connected to a slotted hole 121 through the bolt holes by bolts. Two mounting plates 12 are oppositely provided on the specimen support 1. The specimen 10 is located between the two mounting plates 12. Slotted holes 121 extending in the vertical direction are provided at both ends of each mounting plate 12. The connecting lugs 113 are connected to the slotted holes 121 by bolts. The setting of the slotted holes 121 enables the connecting lugs 113 to change the fixed position in the vertical direction, and the height of the specimen 10 can be adjusted as needed.

[0027] The second web 101 is a component of the test piece 10. The second web 101 is perpendicular to the axial direction of the test piece 10. The end of the second web 101 is connected to the middle part of the connecting rod 21 by threaded fasteners. Cylindrical counterweight blocks 22 are fixed at both ends of the connecting rod 21. The counterweight blocks 22 are coaxially fixed with the connecting rod 21. The axial direction of the connecting rod 21 is parallel to the axial direction of the test piece 10. The counterweight blocks 22 can provide a static load to the test piece 10, and this static load is equal to the average static load received in the actual working condition.

[0028] The fiber optic strain sensor 7 is fixed on the second web 101, and the fiber optic acceleration sensor 8 is fixed on the end face of the test piece 10 at the end away from the second web 101. The preferred model of the fiber optic strain sensor 7 is SFO-W produced by FISO Company in Canada, the preferred model of the fiber optic acceleration sensor 8 is TR-QS-MA, and the preferred model of the fiber optic signal demodulator is UC-instruments-GM8050C.

[0029] The striking mechanism 3 is arranged on the side of the counterweight block 22 away from the second web 101. The striking mechanism 3 includes a first connecting web 31. First striking blocks 32 and second striking blocks 33 are respectively and fixedly connected to both ends of the first connecting web 31. The shapes of the first striking block 32 and the second striking block 33 are both cylinders and are arranged parallel to the axial direction of the test piece 10. The first striking block 32 and the second striking block 33 are fixed between two first connecting webs 31. Striking blocks are arranged at both ends of the first connecting web 31, which can improve the balance of the first connecting web 31, and an impact load will be generated once every half turn.

[0030] The middle part of the first connecting web 31 is detachably connected to the middle connecting plate 34 by threaded fasteners. The middle connecting plate 34 is a square plate. The first connecting web 31 is connected along the diagonal of the middle connecting plate 34. A connecting sleeve is fixed on the side of the middle connecting plate 34 away from the first connecting web 31. The connecting sleeve is sleeved on the output shaft of the motor 4 and is fixed by key connection.

[0031] The middle connecting plate 34 is a square plate, and its function is to improve the force application condition. Since the first connecting web 31 is a long strip-shaped component with relatively low self-strength, if the first connecting web 31 is directly connected to the motor 4, single-point fixation is likely to cause serious stress concentration. By setting the middle connecting plate 34 to be connected to the first connecting web 31, the single-point fixation is changed to multi-point fixation, and the force application method is improved. Since the middle connecting plate 34 has high self-strength, the influence of stress concentration on it is not obvious. The first connecting web 31 is a long rod structure. During the rotation process, it is easy to get stuck, bend or even break when encountering foreign obstacles. The detachable connection between the first connecting web 31 and the middle connecting plate 34 is convenient for replacement and reduces the replacement cost.

[0032] The motor 4 is fixed on the motor support 9. The speed of the motor 4 is adjusted by a speed regulator 6, and the speed regulator 6 is preferably a PWM DC motor speed regulator with the function of digital display of speed. The motor 4 is installed on the top plate of the motor support 9. A strip hole 91 is provided on the bottom plate of the motor support 9. The strip hole 91 is used for bolts to pass through to fix the motor support 9 on the test bench 5. Through the strip hole 91, the fixing position of the motor support 9 on the test bench 5 can be changed, so as to change the relative position between the striking block and the counterweight block.

[0033] A horizontal adjustment mechanism 92 is provided between the mounting plate of the motor 4 and the top plate of the motor support 9. The horizontal adjustment mechanism 92 is preferably a standard part GN 350.2 horizontal adjustment device, and its tilt angle and locking can be set precisely steplessly by a wrench, so as to adjust the orientation of the motor 4 to make the axes of the two striking blocks parallel to the axis of the counterweight block 22.

[0034] The method for conducting tests using the above-mentioned fatigue test device for the pantograph head suspension system includes:

[0035] Step 1: Install the specimen 10 on the specimen support 1, and connect the counterweight mechanism 2, the fiber optic strain sensor 7 and the fiber optic acceleration sensor 8 to the specimen 10.

[0036] Step 2: Calibrate the measurement accuracy of the fiber optic strain sensor 7 and the fiber optic acceleration sensor 8.

[0037] Step 3: Adjust the height of the specimen 10 on the specimen support 1, make the axis of the specimen 10 parallel to the horizontal plane with the help of a spirit level 13, and adjust the installation position of the motor support 9 on the test bench 5 to adjust the relative position between the first striking block 32 and the second striking block 33 and the counterweight block 22, so that the first striking block 32 and the second striking block 33 can strike the counterweight block 22 during rotation, and the striking position is on the outer cylindrical surface.

[0038] Step 4: Apply a marking agent on the first striking block 32 and the second striking block 33. The marking agent can be marking ink or marking powder with a color different from that of the striking block and the counterweight block. It is convenient to find the position where the striking block strikes the counterweight block through the marking agent.

[0039] Start the motor 4 and adjust the speed of the motor 4 to rotate at a speed of 30 - 35 revolutions per minute through the speed regulator 6, so that the first striking block 32 and the second striking block 33 respectively strike the counterweight block 22 once. The marking agent will leave an impact mark at the impact point, and the contact situation between the striking block and the counterweight block can be obtained through the impact mark.

[0040] Step 5: Observe the shape and size of the impact mark left by the marking agent on the counterweight block, and judge whether the length of the impact mark is not less than 80% of the axial length of the first striking block 32 and the angle with the horizontal line is not greater than 3°;

[0041] If so, the installation is qualified, and proceed to Step 6;

[0042] If not, the installation is unqualified. Adjust the horizontal adjustment mechanism 92 on the motor support 9 and then return to Step 4 until the installation is qualified;

[0043] Theoretically, the axes of the first striking block 32 and the second striking block 33 are parallel to the counterweight 22, so the length of the impact mark is equal to the axial length of the striking block. However, since it is impossible to achieve such precision in practice, there will always be a certain degree of inclination within a certain range between the axis of the striking block and the axis of the counterweight. The striking effect is ensured by controlling the allowable range of the inclination.

[0044] Step 6: According to the working condition requirements, use the speed regulator 6 to adjust the rotation speed of the motor 4 to obtain different striking frequencies and striking forces for the fatigue test. Measure the load data through the fiber optic strain sensor 7 and the fiber optic acceleration sensor 8, and after being processed by the fiber optic signal demodulator, it is fed back to the upper computer and stored corresponding to the motor speed.

Claims

1. Test method for a fatigue test device of a pantograph head suspension system Characterized in that the fatigue test device includes a specimen support (1) for adjustably fixing a specimen (10), a counterweight mechanism (2) detachably connected to the specimen (10) is arranged on one side of the specimen support (1), a striking mechanism (3) is arranged on the side of the counterweight mechanism (2) away from the specimen support (1), the striking mechanism (3) is rotatably connected to a motor (4), the motor (4) is adjustably connected to a test bench (5), a speed regulator (6) is connected to the motor (4), a fiber optic strain sensor (7) and a fiber optic acceleration sensor (8) are arranged on the specimen (10), and the fiber optic strain sensor (7) and the fiber optic acceleration sensor (8) are connected to a fiber optic signal demodulator and then connected to a host computer; the specimen support (1) detachably fixes the specimen (10) through a specimen clamp (11), a level (13) is arranged on the specimen clamp (11), the specimen clamp (11) includes a pipe clamp (111), a tightening adjustment mechanism (112) for adjusting its clamping tightness is arranged on the pipe clamp (111), the tightening adjustment mechanism (112) includes two spaced elastic sheets connected by bolts, connection lugs (113) are symmetrically arranged on the pipe clamp (111), the connection lugs (113) are detachably connected to the specimen support (1), two mounting plates (12) are oppositely arranged on the specimen support (1), through holes (121) extending in the vertical direction are arranged at both ends of each mounting plate (12), and the connection lugs (113) are connected to the through holes (121) by bolts; The test method includes: Step 1, install the specimen (10) on the specimen support (1), and connect the counterweight mechanism (2), the fiber optic strain sensor (7) and the fiber optic acceleration sensor (8) to the specimen (10); Step 2, calibrate the measurement accuracy of the fiber optic strain sensor (7) and the fiber optic acceleration sensor (8); Step 3, adjust the height of the specimen (10) on the specimen support (1), make the axis of the specimen (10) parallel to the horizontal plane with the aid of the level (13), and adjust the installation position of the motor support (9) on the test bench (5) to adjust the relative positions of the first striking block (32) and the second striking block (33) and the counterweight block (22); Step 4, fully coat the first striking block (32) and the second striking block (33) with marking agent, start the motor (4) and rotate at a speed of 30 - 35 revolutions per minute, so that the first striking block (32) and the second striking block (33) respectively strike the counterweight block (22) once; Step 5, observe the shape and size of the impact marks left by the marking agent on the counterweight block, and judge whether the length of the impact marks is not less than 80% of the axial length of the first striking block (32) and the angle with the horizontal line is not greater than 3°; If so, the installation is qualified, and proceed to Step 6; If not, the installation is unqualified, adjust the horizontal adjustment mechanism (92) on the motor support (9) and then return to Step 4 until the installation is qualified; Step 6: According to the working condition requirements, use the speed regulator (6) to adjust the rotation speed of the motor (4) to obtain different impact frequencies and impact forces for the fatigue test. Obtain the load data corresponding to the motor speed through the feedback of the fiber optic strain sensor (7) and the fiber optic acceleration sensor (8), and store it in the upper computer.

2. The test method of the fatigue test device for the pantograph head suspension system according to claim 1, characterized in that the striking mechanism (3) includes a first connecting spoke plate (31), and two ends of the first connecting spoke plate (31) are respectively connected with a first striking block (32) and a second striking block (33), and the middle part of the first connecting spoke plate (31) is connected to the motor (4).

3. The test method of the fatigue test device for the pantograph head suspension system according to claim 2, characterized in that the shapes of the first striking block (32) and the second striking block (33) are both cylinders and are arranged parallel to the axis of the test piece (10).

4. The test method of the fatigue test device for the pantograph head suspension system according to claim 3, characterized in that the counterweight mechanism (2) includes a connecting rod (21) and cylindrical counterweight blocks (22) fixed at both ends of the connecting rod (21), and the connecting rod (21) is detachably connected to the test piece (10).

5. The test method of the fatigue test device for the pantograph head suspension system according to claim 2, characterized in that the first connecting spoke plate (31) is connected to the motor (4) through an intermediate connecting plate (34). The intermediate connecting plate (34) is a square plate. The first connecting spoke plate (31) is connected along the diagonal of the intermediate connecting plate (34). The intermediate connecting plate (34) is connected to the output shaft of the motor (4) through a connecting sleeve.

6. The test method of the fatigue test device for the pantograph head suspension system according to claim 1, characterized in that the motor (4) is fixed on a motor support (9). A horizontal adjustment mechanism (92) is arranged on the motor support (9). A strip hole (91) is arranged on the bottom plate of the motor support (9). The motor support (9) is connected to the test bench (5) through bolts passing through the strip hole (91).

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