Pivot rail static contact resistance testing device and application

Abstract

This invention relates to a device and application for testing the static contact resistance of pivot rails, belonging to the field of electromagnetic orbital launch technology. This invention is the first to propose directly measuring the static contact resistance between pivot rails under pressure conditions using a DC low-resistance meter, through the combination of high current potential, high voltage potential, low current potential, and low voltage potential. This invention utilizes a four-column flat press to provide preload force between the pivot rails and to change the static contact pressure. It uses the four-wire method to test the static contact resistance between the pivot rails and uses a DC low-resistance meter to read the contact resistance values, thereby obtaining the static contact resistance values ​​between the pivot rails under different contact pressures. This effectively simulates the actual service conditions of the pivot rails and features simple operation and convenient data reading. The device of this invention is rationally designed, the application process is simple and controllable, the obtained data is highly reliable, and it is suitable for large-scale application.

Description

TECHNICAL FIELD

[0001] The application relates to a pivot-rail static contact resistance testing device and application and belongs to the technical field of electromagnetic rail launching. BACKGROUND

[0002] The electromagnetic rail launching technology is a technology for driving an armature to slide to super-high speed launching by electromagnetic energy, and has the characteristics of high initial speed, good concealment and high combat effectiveness. In the electromagnetic rail launching process, the armature as a working component and the rail (referred to as pivot rail) have sliding electrical contact, and the contact characteristics always affect the electromagnetic rail launching behavior and the rail life. Among them, the contact resistance as one of the parameters for quantitatively representing the contact state between the pivot rail is widely studied. At present, the numerical simulation and formula calculation are mostly used to obtain the numerical value of the contact resistance between the pivot rails, and there are problems such as inconsistency with the actual working condition and approximate calculation results. Moreover, the research on the static contact resistance measurement of the pivot rail after launching is less, and the static contact resistance of the pivot rail under a certain contact pressure cannot be measured. The purpose of the present application is to solve the problem of the static contact resistance testing technology between the pivot rails after the electromagnetic rail launching, and provide a contact resistance measuring device and technology between special-shaped parts. The contact resistance measuring device and technology can provide pre-tightening force to the pivot rail and directly measure the static contact resistance between the pivot rails under different contact pressures.

[0003] The electromagnetic launching technology is an advanced launching technology for realizing super-high speed and precise continuous launching of objects by electromagnetic force. The working components thereof include two parallel rails and an armature carrying a projectile. The current is input to one of the rails, flows through the armature and returns from the other rail to form a loop. Due to the current loop, the Lorentz force is generated to push the armature to realize super-high speed and precise launching at a speed greater than 2000 m / s.

[0004] During the electromagnetic rail launching process, the armature and the rail belong to sliding electrical contact, the contact state between the pivot rails presents solid-solid, solid-liquid-solid and solid-arc alternating change, and due to the uneven distribution of the contact pressure, the contact resistance between the pivot rails changes during the launching process, causing the thermal loss of the electromagnetic launching device and seriously affecting the electromagnetic launching behavior and the rail life. In addition to the qualitative description of the contact state between the pivot rails through the surface features, the contact resistance can also be quantitatively characterized. The pivot rails are in interference fit under a certain pre-tightening force, and therefore, it is of great significance to master the electromagnetic rail launching behavior and the service life of the launching device by measuring the static contact resistance between the pivot rails under different pressures.

[0005] The contact surface between the armature and the rail is not ideal contact, but rough, uneven, and a series of microscopic spots form the contact between the two solids, that is, the microscopic contact spots form the contact resistance. As a key parameter reflecting the contact characteristics between the armature and the rail, the contact resistance is affected by external factors such as temperature and humidity, and internal factors such as contact pressure and sample properties. The traditional static contact resistance testing device can only measure the contact resistance between the planes, and lacks direct measurement technology for the contact resistance of special-shaped parts under a certain contact pressure. Since the rail and the armature are in interference fit under a certain pre-tightening force during the electromagnetic rail launching process, and both belong to special-shaped parts. Therefore, it is necessary to build a device that can stably provide pressure and directly measure the contact resistance between special-shaped parts in a certain environment.

[0006] To solve the above problems, the existing solutions mostly indirectly obtain the contact resistance value by directly obtaining parameters related to the contact resistance, or directly measure it by using a direct current low resistance meter. Chinese published patent document CN109188096B obtains two different frequency alternating currents and the corresponding voltage values, and deduces the contact resistance of the pre-twisted wire and the ground wire contact port through a formula. This technology obtains the contact resistance value by formula calculation, and uses alternating current. Chinese published patent document CN111426883B discloses a test method and test circuit for intermetallic contact resistance, which establishes a closed loop, calculates the total resistance of the circuit under a certain input voltage and current, and obtains the contact resistance value between the metals. At present, there are few tests on the static contact resistance between the armature and the rail, such as the static contact resistance test between the armature and the rail by Lei Bin et al. using a direct current low resistance meter, which obtains a change curve, but does not study the influence of contact pressure on contact resistance. Since the contact between the armature and the rail is under a certain pre-tightening force, this study cannot reflect the actual working condition of the armature and the rail. The above patent documents use indirect acquisition or direct measurement to obtain the contact resistance value, which cannot meet the direct and accurate measurement of the contact resistance between special-shaped parts under different contact pressures. SUMMARY

[0007] The present application is directed to the deficiencies of the prior art, and for the first time proposes to use a direct current low resistance meter under pressure conditions between the armature and the rail, and to directly measure the static contact resistance between the armature and the rail by cooperation of high current position, high voltage position, low current position and low voltage position.

[0008] In order to directly and accurately measure the static contact resistance between the armature and the rail under pressure, a set of test devices is specially designed and a test process matched with the device is developed, and through the test process of the present application, data with little fluctuation and high accuracy can be obtained (for the same test sample and test process).

[0009] The application discloses a pivot rail static contact resistance testing device, and the pivot rail comprises an upper rail, a lower rail and an armature; in a pressurized state, the side of the upper rail in contact with the armature is defined as an upper rail working surface, the upper rail working surface has an upper rail convex part A and an upper rail edge C parallel to an upper rail reserved surface B opposite to the upper rail working surface; in the pressurized state, the side of the lower rail in contact with the armature is defined as a lower rail working surface; the lower rail working surface has a lower rail convex part D and a lower rail edge F parallel to a lower rail reserved surface E opposite to the lower rail working surface.

[0010] The pivot rail static contact resistance testing device comprises a direct current low resistance tester, four connecting lines, a pressure supply device, four copper wires, insulating adhesive tape and four adhesive columns formed by conductive adhesive; two of the four copper wires are bonded to the upper rail edge C of the upper rail by the conductive adhesive, thereby forming a first adhesive column and a second adhesive column; the two copper wires are in contact with the upper rail edge C, the distance between the two copper wires is greater than or equal to 2 cm, and the distance between the first adhesive column and the second adhesive column is greater than or equal to 2 cm.

[0011] The other two of the four copper wires are bonded to the lower rail edge F of the lower rail by the conductive adhesive, and the two copper wires are in contact with the upper rail edge F, thereby forming a third adhesive column and a fourth adhesive column; the distance between the two copper wires is greater than or equal to 2 cm, and the distance between the third adhesive column and the fourth adhesive column is greater than or equal to 2 cm.

[0012] The direct current low resistance tester is connected to one end of the four connecting lines, and the other end of the four connecting lines is connected to the copper wires in the first adhesive column, the second adhesive column, the third adhesive column and the fourth adhesive column respectively.

[0013] The insulating adhesive tape is arranged on the upper rail reserved surface B and the lower rail reserved surface E; after the insulating adhesive tape is arranged, the pressure supply device is connected.

[0014] After assembly, the armature is located between the upper rail and the lower rail, and the armature is in contact with the upper rail and the lower rail after being pressurized.

[0015] After assembly, the first adhesive column, the second adhesive column, the third adhesive column and the fourth adhesive column are located on the same side.

[0016] According to the emission direction of the armature, the first adhesive column is located in front of the second adhesive column, and the third adhesive column is located in front of the fourth adhesive column; the copper wire in the first adhesive column is connected to the high current position in the direct current low resistance tester through the connecting line, the copper wire in the second adhesive column is connected to the high voltage position in the direct current low resistance tester through the connecting line; the copper wire in the third adhesive column is connected to the low current position in the direct current low resistance tester through the connecting line, and the copper wire in the fourth adhesive column is connected to the low voltage position in the direct current low resistance tester through the connecting line.

[0017] Or

[0018] According to the direction of the armature emission, the first glue column is located in front of the second glue column, the third glue column is located in front of the fourth glue column, and the copper wire in the first glue column is connected to the low current position in the direct current low resistance instrument through a connecting line, and the copper wire in the second glue column is connected to the low voltage position in the direct current low resistance instrument through a connecting line; and the copper wire in the third glue column is connected to the high current position in the direct current low resistance instrument through a connecting line, and the copper wire in the fourth glue column is connected to the high voltage position in the direct current low resistance instrument through a connecting line.

[0019] As a preferred solution, the pressure supply device is a four-column flat press. The maximum pressure that can be provided is 5t.

[0020] The pivot rail is an existing pivot rail. Meanwhile, the device developed by the present application can be used with subsequent newly developed pivot rails.

[0021] As a preferred solution, the direct current low resistance instrument has a high range of 20mΩ-2MΩ and a high resolution of 0.001mΩ, which can meet the measurement requirements of the contact resistance between the pivot rails and quickly and accurately read data. In engineering applications, the direct current low resistance instrument can be selected as a direct current low resistance instrument with a model of Teans TD2516A.

[0022] In the present application, the distance between the first glue column and the second glue column and the third glue column and the fourth glue column is strictly controlled, because research has found that if the distance between the glue columns is too small, the current test end and the voltage test end are easy to contact and short circuit, so that the resistance of the current end and the voltage end cannot be eliminated, thereby causing errors in the measurement of the static contact resistance value between the pivot rails and affecting the accuracy.

[0023] In the present application, the heights of the four glue columns are consistent, preferably 3-5mm.

[0024] In the present application, according to the direction of the armature emission, the current position must be before the voltage position (i.e. when the armature is emitted from the track, the distance from the voltage position to the armature tail wing is greater than the distance from the current position to the armature tail wing), which not only restores the actual emission working condition, but also reduces data noise and improves measurement accuracy.

[0025] In the present application, the high current position and the high voltage position must be on the same side. This is to better eliminate the error influence of the self-resistance of the contact wire, and the high current position and the high voltage position need to form a test path along the emission direction. Similarly, the low current position and the low voltage position must also be on the same side.

[0026] Meanwhile, after the equipment of the present application is assembled, the first glue column, the second glue column, the third glue column and the fourth glue column are on the same side, because only when the first glue column, the second glue column, the third glue column and the fourth glue column are on the same side, the contact resistance value of the test loop formed along the emission direction of the contact surface between the pivot rails can be measured. Otherwise, the measured value will be inaccurate and other adverse effects will occur.

[0027] As a preferred solution, the four connecting lines are four connecting lines with alligator clips. The material of the alligator clip connecting line clamp head and the track lead-out line is copper alloy, which has good conductivity and is suitable for contact resistance measurement.

[0028] As a preferred solution, the four-column flat press machine can uniformly and stably pressurize the test component, and the pressure gauge can directly read the pressure value.

[0029] As a preferred solution, the conductive glue is epoxy conductive glue.

[0030] In the present application, the insulating tape can be more flatly attached to the back of the track (i.e. the upper track reserved surface B and the lower track reserved surface E), and the back of the track and the flat plate of the flat press machine are insulated. This can improve the accuracy of the obtained test results.

[0031] The test device implements a test method for the contact resistance of a special-shaped piece, which includes the following steps:

[0032] (1) Mark the positions of the glue columns on the same side of the upper track edge C and the lower track edge F along the armature emission direction with a marker pen, wherein the second glue column and the fourth glue column are marked at the emission starting end, the distance between the first glue column and the second glue column and the distance between the third glue column and the fourth glue column are both greater than or equal to 2 cm, the first glue column is in front of the second glue column, the third glue column is in front of the fourth glue column, and the marked glue column positions at the upper and lower track edges correspond vertically, the first glue column corresponds to the third glue column, and the second glue column corresponds to the fourth glue column.

[0033] (2) tightly attach a copper wire to the marked position of the glue column, one copper wire (about 8 cm long) for each marked position; use epoxy conductive glue to fix the copper wire at the corresponding glue column position marked on the upper track edge C and the lower track edge F, and place it at room temperature until the glue column solidifies. The placement time is determined according to the solidification condition of the glue column. It can be 1-24 hours.

[0034] (3) Flatly attach insulating tape to the upper track reserved surface B and the lower track reserved surface E, and the insulating tape needs to be tightly attached to the track reserved surface.

[0035] (4) Before assembly, clean the contact surface by wiping the upper track protrusion A, the armature surface, and the lower track protrusion D with alcohol.

[0036] (5) When assembling, the upper track protrusion A, the armature, and the lower track protrusion D form a test component from top to bottom with the armature emission direction as the reference. Along the armature emission direction, when the armature is ejected out of the track, the distance from the armature tail wing to the first glue column and the third glue column is less than the distance from the armature tail wing to the second glue column and the fourth glue column.

[0037] (6) Place the assembled test component smoothly into the lower platen of the flat press. At this time, pay attention to whether the upper rail working surface, armature, and lower rail working surface are perpendicular. Then pre-pressurize to make the reserved surface B of the upper rail contact the upper platen of the flat press.

[0038] (7) Assemble the wires along the armature firing direction. The copper wire in the first adhesive column is connected to the low current potential of the DC low resistance meter via a connecting wire; the copper wire in the second adhesive column is connected to the low voltage potential of the DC low resistance meter via a connecting wire; and the copper wire in the third adhesive column is connected to the high current potential of the DC low resistance meter via a connecting wire; and the copper wire in the fourth adhesive column is connected to the high voltage potential of the DC low resistance meter via a connecting wire.

[0039] (8) After the circuit is connected, use a flat press to slowly pressurize the test component. After the pressure stabilizes, read the contact resistance value displayed in the DC low resistance meter.

[0040] (9) Remove the connecting wire, slowly release the pressure, and take out the test component.

[0041] The preferred marker is a pencil.

[0042] Furthermore, in step (2), the conductive adhesive needs to be fully cured.

[0043] Furthermore, in step (4), the wiping is performed using a non-woven cloth soaked in alcohol to ensure that the test surface is not damaged.

[0044] Preferably, the copper wire selected in this invention has a cross-sectional area greater than or equal to 1.5 mm². 2 If the diameter is too small, the copper wire will have unstable contact with the edge of the track, resulting in excessively large or unstable data during the contact resistance test, making it impossible to read.

[0045] The above-described apparatus and technology of the present invention have the following advantages:

[0046] The device and technology of this invention utilize a four-column flat press to provide preload force between the pivot rails and change the static contact pressure between the pivot rails. It uses the four-wire method principle to test the static contact resistance between the pivot rails and uses a DC low resistance meter to read the contact resistance value, thereby obtaining the static contact resistance value between the pivot rails under different contact pressures. This effectively simulates the actual service conditions of the pivot rails and has the characteristics of simple operation and convenient data reading. At the same time, the test results obtained by this invention are relatively stable with small fluctuations.

[0047] Compared with other traditional contact resistance test schemes, the device and technology are used for measuring the static contact resistance between the special-shaped pivot rails after electromagnetic track launching; compared with other pivot rail static contact resistance measurements, the scheme can directly measure the static contact resistance between the pivot rails under different contact pressures, and the pressure value meets the pre-tightening force of the pivot rail in service. The technology effectively simulates the actual service working condition of the pivot rail. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 The schematic diagram for the conductive copper wire is shown in the figure.

[0049] Figure 2 The schematic diagram for the contact resistance test is shown in the figure.

[0050] Figure 3 The schematic diagram for the test component assembly is shown in the figure.

[0051] Figure 4 The physical diagram during measurement is shown in the figure. DETAILED DESCRIPTION

[0052] In the examples and comparative examples of the present application, the track material is CuCrZr alloy, and the armature material is 7075 Al alloy.

[0053] In the examples and comparative examples of the present application, the pivot rail used includes an upper rail, a lower rail and an armature. In a pressed state, the side of the upper rail in contact with the armature is defined as the upper rail working surface, which has an upper rail protruding portion A and an upper rail edge C parallel to the upper rail reserved surface B, and the upper rail reserved surface B is opposite to the upper rail working surface. In a pressed state, the side of the lower rail in contact with the armature is defined as the lower rail working surface, which has a lower rail protruding portion D and a lower rail edge F parallel to the lower rail reserved surface E, and the lower rail reserved surface E is opposite to the lower rail working surface.

[0054] Example 1: This example provides a measurement of the static contact resistance when the unserved upper rail is paired with the unserved lower rail:

[0055] With the armature launching direction as the reference, the positions of the glue columns are marked at the corresponding positions of the edges of the unserved upper and lower rails, and the cross-sectional area of the conductive epoxy at the marked positions of the first, second, third and fourth glue columns is 1.5mm 2copper wire fixing, wherein the distance between the first glue column and the second glue column, and the distance between the third glue column and the fourth glue column are both 2 cm, the first glue column is in front of the second glue column, and the third glue column is in front of the fourth glue column. After the epoxy conductive adhesive is completely cured, insulating glue is used to paste the unserved upper rail reserved surface (upper rail reserved surface B) and the unserved lower rail reserved surface (lower rail reserved surface E) for insulation treatment. Further, the unserved upper rail, the armature, and the unserved lower rail are assembled in the center of the flat pressing machine working space in the order from top to bottom, wherein the armature tail wing is close to the first glue column and the third glue column. The flat pressing machine is started so that the unserved upper rail reserved surface B (with insulating glue) is in contact with the upper flat plate of the flat pressing machine, and after a certain pre-tightening force is obtained, the test component is wired. Along the direction of the armature emission, the wires are assembled. Among them, the copper wire in the first glue column is connected to the low current position in the direct current low resistance instrument through a connecting wire, and the copper wire in the second glue column is connected to the low voltage position in the direct current low resistance instrument through a connecting wire; and the copper wire in the third glue column is connected to the high current position in the direct current low resistance instrument through a connecting wire, and the copper wire in the fourth glue column is connected to the high voltage position in the direct current low resistance instrument through a connecting wire. Adjust the pressure of the flat pressing machine, and directly read the contact resistance values under the contact pressures of 0.6, 0.7, 0.8, 0.9, and 1.0 t by the direct current low resistance instrument of the type of Teans TD2516A, which are 0.354±0.001 mΩ, 0.335±0.001 mΩ, 0.324±0.001 mΩ, 0.305±0.001 mΩ, and 0.292±0.001 mΩ (measured 5 times under each pressure). Among them, 0.8 t is closer to the pressure when the trolley rail is actually served.

[0056] Example 2: This example provides a measurement of the static contact resistance when the served upper rail is paired with the unserved lower rail;

[0057] With the armature emission direction as the reference, the glue column positions are marked at the corresponding positions of the served upper rail edge and the unserved lower rail edge, and the cross-sectional area of 1.5 mm 2copper wire fixing, wherein the distance between the first glue column and the second glue column, the third glue column and the fourth glue column is 2 cm, the first glue column is in front of the second glue column, and the third glue column is in front of the fourth glue column. After the epoxy conductive adhesive is completely cured, use the insulating glue to paste on the reserved surface of the in-service upper rail and the reserved surface of the non-service lower rail for insulation treatment. Further, the in-service upper rail, the armature and the non-service lower rail are assembled in the center of the flat pressing machine working space in the order from top to bottom, and the tail wing of the armature is close to the first glue column and the third glue column. Start the flat pressing machine to make the reserved surface B of the in-service upper rail contact with the upper flat plate of the flat pressing machine, and after a certain pre-tightening force is obtained, the test part is wired. Along the direction of the armature emission, the copper wire in the first glue column is connected with the low current position in the direct current low resistance instrument through the connecting wire, and the copper wire in the second glue column is connected with the low voltage position in the direct current low resistance instrument through the connecting wire; and the copper wire in the third glue column is connected with the high current position in the direct current low resistance instrument through the connecting wire, and the copper wire in the fourth glue column is connected with the high voltage position in the direct current low resistance instrument through the connecting wire. Adjust the pressure of the flat pressing machine, and directly read the contact resistance values under the contact pressures of 0.6, 0.7, 0.8, 0.9 and 1.0 t by the direct current low resistance instrument with the model of Tiansi TD2516A, which are 0.157±0.001 mΩ, 0.149±0.001 mΩ, 0.134±0.001 mΩ, 0.129±0.001 mΩ and 0.120±0.001 mΩ (measured 5 times under each pressure) respectively. Among them, 0.8 t is closer to the actual service pressure of the pivot rail.

[0058] Example 3: This example provides a measurement of the static contact resistance when the non-service upper rail is paired with the in-service lower rail;

[0059] With the armature emission direction as the reference, mark the glue column positions at the corresponding positions of the non-service upper rail edge and the in-service lower rail edge, and use the epoxy conductive adhesive to tightly paste the cross-sectional area of 1.5 mm 2copper wire fixing, wherein the distance between the first glue column and the second glue column, the third glue column and the fourth glue column is 2 cm, the first glue column is in front of the second glue column, and the third glue column is in front of the fourth glue column. After the epoxy conductive adhesive is completely cured, use insulating tape to paste on the unserved upper rail reserved surface and the served lower rail reserved surface for insulation treatment. Further, the unserved upper rail, the armature and the served lower rail are assembled in the center of the flat pressing machine working space in the order from top to bottom, and the armature tail wing is close to the first glue column and the third glue column. Start the flat pressing machine to make the unserved upper rail reserved surface B contact with the upper flat plate of the flat pressing machine, and after a certain pre-tightening force is obtained, the test component is wired. Along the direction of the armature emission, the copper wire in the first glue column is connected to the low current position in the direct current low resistance instrument through the connecting wire, and the copper wire in the second glue column is connected to the low voltage position in the direct current low resistance instrument through the connecting wire; and the copper wire in the third glue column is connected to the high current position in the direct current low resistance instrument through the connecting wire, and the copper wire in the fourth glue column is connected to the high voltage position in the direct current low resistance instrument through the connecting wire. Adjust the pressure of the flat pressing machine, and directly read the contact resistance values under the contact pressures of 0.6, 0.7, 0.8, 0.9 and 1.0 t by the direct current low resistance instrument of the type of Teans TD2516A, which are 0.255±0.001 mΩ, 0.243±0.001 mΩ, 0.209±0.001 mΩ, 0.200±0.001 mΩ and 0.188±0.001 mΩ (measured 5 times under each pressure) respectively. Among them, 0.8 t is closer to the actual service pressure of the trolley rail.

[0060] Example 4: This example provides a measurement of the static contact resistance when the served upper rail is paired with the served lower rail;

[0061] With the armature emission direction as the reference, mark the glue column positions at the corresponding positions of the served upper rail edge and the served lower rail edge, and use the epoxy conductive adhesive to tightly paste the cross-sectional area of 1.5 mm 2copper wire fixing, wherein the distance between the first glue column and the second glue column, the third glue column and the fourth glue column is 2 cm, the first glue column is in front of the second glue column, and the third glue column is in front of the fourth glue column. After the epoxy conductive adhesive is completely cured, the insulating tape is flatly pasted on the service upper rail reserved surface and the service lower rail reserved surface for insulation treatment. Further, the unserved upper rail, the armature and the served lower rail are assembled in the center of the flat pressing machine working space in the order from top to bottom, and the tail wing of the armature is close to the first glue column and the third glue column. Start the flat pressing machine to make the service upper rail reserved surface B contact with the upper flat plate of the flat pressing machine, and after a certain pre-tightening force is obtained, the test part is wired. Along the direction of the armature emission, the copper wire in the first glue column is connected with the low current position in the direct current low resistance instrument through the connecting wire, and the copper wire in the second glue column is connected with the low voltage position in the direct current low resistance instrument through the connecting wire; and the copper wire in the third glue column is connected with the high current position in the direct current low resistance instrument through the connecting wire, and the copper wire in the fourth glue column is connected with the high voltage position in the direct current low resistance instrument through the connecting wire. Adjust the pressure of the flat pressing machine, and directly read the contact resistance values under the contact pressures of 0.6, 0.7, 0.8, 0.9 and 1.0 t by the direct current low resistance instrument with the model of Teans TD2516A, which are 0.130±0.001 mΩ, 0.118±0.001 mΩ, 0.110±0.001 mΩ, 0.105±0.001 mΩ and 0.100±0.001 mΩ (measured 5 times under each pressure) respectively. Among them, 0.8 t is closer to the actual service pressure of the trolley rail.

[0062] Comparative Example 1: The conditions are consistent with Example 4, except that the voltage test glue column is in front of the current test glue column.

[0063] With the armature emitting direction as the reference, mark the glue column positions at the corresponding positions of the service upper rail edge and the service lower rail edge, and fix the copper wire close to the marked positions of the first glue column, the second glue column, the third glue column and the fourth glue column with the epoxy conductive glue, wherein the distance between the first glue column and the second glue column, the third glue column and the fourth glue column is 2 cm, the first glue column is in front of the second glue column, and the third glue column is in front of the fourth glue column. After the epoxy conductive glue is completely cured, use the insulating tape to paste on the service upper rail reserved surface and the service lower rail reserved surface for insulation treatment. Further, the service upper rail, the armature and the service lower rail are assembled in the center of the flat pressing machine working space in the order from top to bottom. Start the flat pressing machine to make the service upper rail reserved surface B contact with the upper flat plate of the flat pressing machine, and after a certain pre-tightening force is obtained, the test component is wired. Along the armature emitting direction, the wires are assembled. Among them, the copper wire in the first glue column is connected with the low voltage position in the direct current low resistance instrument through the connecting wire, and the copper wire in the second glue column is connected with the low current position in the direct current low resistance instrument through the connecting wire; and the copper wire in the third glue column is connected with the high voltage position in the direct current low resistance instrument through the connecting wire, and the copper wire in the fourth glue column is connected with the high current position in the direct current low resistance instrument through the connecting wire. Adjust the pressure of the flat pressing machine, and directly read the contact resistance values under the contact pressures of 0.6, 0.7, 0.8, 0.9 and 1.0 t by the direct current low resistance instrument with the model of Teacs TD2516A, which are 0.208±0.002 mΩ, 0.191±0.003 mΩ, 0.165±0.002 mΩ, 0.155±0.005 mΩ and 0.145±0.002 mΩ respectively. Compared with Example 4, the measured results are obviously larger, and the data is unstable.

[0064] Comparative Example 2:

[0065] The other conditions are consistent with Example 4, except that the service upper rail reserved surface and the service lower rail reserved surface are not pasted with insulating tape.

[0066] The static contact resistance values between the pivot rail and the rail under different contact pressures cannot be obtained.

[0067] Comparative Example 3:

[0068] The other conditions are consistent with Example 4, except that the distance between the first glue column and the second glue column is too small (1 cm); and the distance between the third glue column and the fourth glue column is consistent with the distance between the first glue column and the second glue column.

[0069] This resulted in an inaccurate measurement of the static contact resistance between the pivot and rail under different contact pressures, failing to eliminate wiring resistance errors and leading to excessively high contact resistance values. Specifically, the pressure of the flatbed press was adjusted, and the contact resistance values ​​were directly read using a Teans TD2516A DC low-resistance meter at contact pressures of 0.6, 0.7, 0.8, 0.9, and 1.0t, respectively, yielding values ​​of 0.15–0.3 mΩ, 0.15–0.25 mΩ, 0.15–0.20 mΩ, 0.15–0.2 mΩ, and 0.15–0.3 mΩ. Compared to Example 4, the measured results were significantly higher and exhibited excessively unstable fluctuations. The obtained data was essentially unusable for subsequent analysis.

Claims

1. A pivot rail static contact resistance testing device, characterized in that: The pivot rail includes an upper rail, a lower rail, and an armature. Under pressure, the side of the upper rail that contacts the armature is defined as the upper rail working surface. The upper rail working surface has an upper rail protrusion A and an upper rail edge C parallel to the upper rail reserved surface B. The upper rail reserved surface B is opposite to the upper rail working surface. Under pressure, the side of the lower rail that contacts the armature is defined as the lower rail working surface. The lower rail working surface has a lower rail protrusion D and a lower rail edge F parallel to the lower rail reserved surface E. The lower rail reserved surface E is opposite to the lower rail working surface. The pivot rail static contact resistance testing device includes a DC low resistance tester, four connecting wires, a pressure supply device, four copper wires, insulating tape, and four adhesive pillars made of conductive adhesive. Two of the four copper wires are bonded to the upper rail edge C of the upper rail with conductive adhesive to form the first adhesive pillar and the second adhesive pillar. These two copper wires are in contact with the upper rail edge C, and the distance between the two copper wires is greater than or equal to 2 cm, and the distance between the first adhesive pillar and the second adhesive pillar is greater than or equal to 2 cm. Two of the four copper wires are bonded to the lower rail edge F of the lower rail with conductive adhesive, and these two copper wires are in contact with the upper rail edge F, forming the third adhesive post and the fourth adhesive post; the distance between the two copper wires is greater than or equal to 2cm, and the distance between the third adhesive post and the fourth adhesive post is greater than or equal to 2cm. The DC low resistance tester is connected to one end of four connecting wires, and the other end of the four connecting wires is connected to the copper wires in the first, second, third, and fourth glue columns, respectively. Insulating tape is applied to the upper rail reserved surface B and the lower rail reserved surface E. After the insulating tape is applied, connect it to the pressure supply device. After assembly, the armature is located between the upper and lower rails, and after pressure is applied, the armature makes contact with the upper and lower rails; After assembly, the first, second, third, and fourth adhesive columns are located on the same side; According to the armature firing direction, the first adhesive post is located in front of the second adhesive post; the third adhesive post is located in front of the fourth adhesive post; and the copper wire in the first adhesive post is connected to the high current potential in the DC low resistance meter through a connecting wire, the copper wire in the second adhesive post is connected to the high voltage potential in the DC low resistance meter through a connecting wire; and the copper wire in the third adhesive post is connected to the low current potential in the DC low resistance meter through a connecting wire, and the copper wire in the fourth adhesive post is connected to the low voltage potential in the DC low resistance meter through a connecting wire. or According to the armature firing direction, the first adhesive post is located in front of the second adhesive post; the third adhesive post is located in front of the fourth adhesive post; and the copper wire in the first adhesive post is connected to the low current potential in the DC low resistance meter through a connecting wire, the copper wire in the second adhesive post is connected to the low voltage potential in the DC low resistance meter through a connecting wire; and the copper wire in the third adhesive post is connected to the high current potential in the DC low resistance meter through a connecting wire, and the copper wire in the fourth adhesive post is connected to the high voltage potential in the DC low resistance meter through a connecting wire.

2. The pivot rail static contact resistance testing device according to claim 1, characterized in that: The pressure supply device is a four-column flat press.

3. The pivot rail static contact resistance testing device according to claim 1, characterized in that: The DC low resistance instrument has a high measuring range of 20mΩ to 2MΩ and a high resolution of 0.001 mΩ.

4. The pivot rail static contact resistance testing device according to claim 1, characterized in that: The four rubber columns are all the same height, which is 3~5mm.

5. The pivot rail static contact resistance testing device according to claim 1, characterized in that: According to the armature firing direction, the current potential must precede the voltage potential. That is, when the armature is fired from the track, the distance from the voltage potential to the armature tail fin must be greater than the distance from the current potential to the armature tail fin.

6. The pivot rail static contact resistance testing device according to claim 1, characterized in that: The high current potential and high voltage potential are on the same side; the low current potential and low voltage potential are on the same side, and After the equipment is assembled, the first, second, third, and fourth glue columns are on the same side.

7. The pivot rail static contact resistance testing device according to claim 1, characterized in that: The insulating tape is flatly attached to the back of the track, that is, it is bonded to the reserved surface B of the upper track and the reserved surface E of the lower track, thus insulating the back of the track and the flatbed of the press.

8. An application of the pivot rail static contact resistance testing device as described in any one of claims 1-7, characterized in that; Includes the following steps: (1) Mark the position of the rubber column with a marker on the same side of the upper rail edge C and the lower rail edge F along the armature transmission direction. The second and fourth rubber columns are marked at the starting end of the transmission. The distance between the marked positions of the first and second rubber columns and between the marked positions of the third and fourth rubber columns is greater than or equal to 2cm. The first rubber column is in front of the second rubber column, and the third rubber column is in front of the fourth rubber column. The positions of the rubber columns marked on the upper and lower rail edges should correspond vertically. The first rubber column corresponds to the third rubber column, and the second rubber column corresponds to the fourth rubber column. (2) Place the copper wires tightly against the marked positions on the adhesive column, with one copper wire tightly attached to each marked position; Use epoxy conductive adhesive to fix the copper wires to the corresponding adhesive pillar positions marked with C on the upper rail edge and F on the lower rail edge, and place them at room temperature to allow the adhesive pillars to cure. (3) Apply insulating tape evenly to the reserved surface B of the upper rail and the reserved surface E of the lower rail. The insulating tape must be tightly attached to the reserved surface of the rail. (4) Before assembly, wipe the upper rail protrusion A, armature surface and lower rail protrusion D with alcohol to clean the contact surfaces; (5) During assembly, with the armature firing direction as the reference, the upper rail protrusion A, the armature, and the lower rail protrusion D form the test component from top to bottom. Among them, along the armature firing direction, when the armature is ejected from the track, the distance from the armature tail fin to the first and third glue posts is less than the distance from the armature tail fin to the second and fourth glue posts. (6) Place the assembled test component smoothly into the lower platen of the flat press, ensuring that the upper rail working surface, armature and lower rail working surface are perpendicular; then pre-pressurize so that the reserved surface B of the upper rail contacts the upper platen of the flat press. (7) Assemble the wires along the armature firing direction; wherein, the copper wire in the first adhesive column is connected to the low current potential in the DC low resistance meter through the connecting wire, the copper wire in the second adhesive column is connected to the low voltage potential in the DC low resistance meter through the connecting wire; and the copper wire in the third adhesive column is connected to the high current potential in the DC low resistance meter through the connecting wire, and the copper wire in the fourth adhesive column is connected to the high voltage potential in the DC low resistance meter through the connecting wire. (8) After the circuit is connected, use a flat press to slowly pressurize the test component. After the pressure stabilizes, read the contact resistance value displayed in the DC low resistance meter. (9) Remove the connecting wire, slowly release the pressure, and take out the test component.

9. The application of the pivot rail static contact resistance testing device according to claim 8, characterized in that: In step (1), the marker is a pencil; In step (4), wiping is performed using a non-woven cloth soaked in alcohol.

10. The application of the pivot rail static contact resistance testing device according to claim 8, characterized in that: The cross-sectional area of ​​the copper wire used is greater than or equal to 1.5 mm². 2 .

Images