Rail low-temperature brazing equipment for current-sharing copper bar and brazing process thereof

Abstract

The application discloses a kind of steel rail low-temperature brazing equipment of current-sharing copper bar and brazing process thereof, belong to brazing equipment field, including steel rail body, the bottom of the two sides of the steel rail body is equipped with the base compatible with rail waist, two the base is respectively equipped with current-sharing copper bar body and electric heating plate, the side of the steel rail body is equipped with support plate, the support plate is evenly slidably installed with slide rod, the one end of each the slide rod is rotatably installed with rotating rod, and the rotating rod is rotatably installed with the plate between each the rotating rod;Knocking assembly, including fixedly installed in the other end of each the slide rod push plate, the other side of the push plate is sequentially provided with multiple round frames along its length direction;Can be realized by disc-shaped bimetallic strip heat jump flip generation multistage sequentially impact vibration, promote liquid brazing material in copper steel adhesion interface sufficient wetting spread and drive bubble, effectively solve the problem of poor flowability of brazing material in low-temperature brazing, insufficient bonding strength of welding interface.

Description

Technical Field

[0001] This invention relates to the field of brazing equipment, and more specifically, to a low-temperature brazing equipment for a current-equalizing copper busbar for rails and its brazing process. Background Technology

[0002] Currently, in the traction power supply return system of rail transit, the current-equalizing copper busbar is usually used as the transfer conductor between the rail and the return cable. The connection methods mainly include traditional fusion welding, bolt crimping, and ordinary brazing. Traditional fusion welding has a high temperature (usually above 900℃), which can easily lead to the transformation of the metallographic structure of the rail base material, reducing its mechanical strength and fatigue life. In addition, the heat-affected zone is large, making it difficult to meet the requirements of non-destructive connection. Although bolt crimping avoids high-temperature operation, it has high contact resistance and is prone to loosening and heating, making it difficult to ensure the long-term stable transmission of large current. Although the welding temperature of ordinary brazing is lower than that of fusion welding, it still has a certain impact on the performance of the rail base material.

[0003] While low-temperature brazing technology can theoretically reduce the welding temperature and shrink the heat-affected zone (the welding temperature is usually ≤350℃), in practice, when applied to large-area bonding welding of current-equalizing copper busbars and steel rails, the significant differences in the thermophysical properties of copper and steel, coupled with insufficient wetting and spreading properties of liquid brazing filler metal at low temperatures at the copper-steel interface, make it difficult to fully fill the welding interface under capillary action. This easily leads to defects such as weld porosity and incomplete welding, resulting in insufficient bonding strength and electrical conductivity. Furthermore, due to the different coefficients of thermal expansion between copper and steel, a large amount of internal stress remains after the weld cools. Under long-term vibration and impact loads from train operation, the brazed joint has poor fatigue resistance and is prone to cracking, detachment, loosening, and other failures, seriously affecting train operation safety and power supply reliability. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention aims to provide a low-temperature brazing equipment and brazing process for a copper busbar, which can achieve multi-level sequential impact vibration generated by the heating and sudden flipping of a disc-shaped bimetallic strip, promote the full wetting and spreading of liquid brazing filler metal at the copper-steel interface and remove air bubbles, effectively solving the problems of poor filler metal fluidity and insufficient bonding strength at the welding interface in low-temperature brazing.

[0005] To solve the above problems, the present invention adopts the following technical solution.

[0006] A low-temperature brazing device for a current-equalizing copper busbar on a rail includes a rail body. Bases adapted to the bottom wall of the rail web are provided on both sides of the rail body. A current-equalizing copper busbar body and an electric heating plate are respectively provided on the two bases. A support plate is provided on one side of the rail body. Sliding rods are uniformly slidably mounted on the support plate. A rotating rod is rotatably mounted at one end of each sliding rod, and a lever is rotatably mounted between each rotating rod.

[0007] The striking assembly includes a push plate fixedly installed at the other end of each of the slide rods. Multiple circular frames are sequentially arranged along the length of the other side of the push plate. The last circular frame is fixedly installed to the push plate. A spring is installed between each of the remaining circular frames and the push plate. An opening is provided on the other side of each circular frame, and a T-shaped plate is slidably installed within the opening. A limiting plate opposite to the T-shaped plate is fixedly installed within the circular frame. A spring is arranged between the limiting plate and the T-shaped plate. A disc-shaped bimetallic strip is installed within the circular frame, with its concave side facing the limiting plate.

[0008] Furthermore, one side of the support plate is fixedly equipped with cylinders of the same number as the sliding rods. Each group of sliding rods is slidably installed with the adjacent cylinder. Each group of sliding rods is sleeved on the outer wall of the rotating rod. A hollow frame is provided on the outer side of the push plate. The side wall of the hollow frame is evenly provided with air vents, and the air vents are not connected to the interior of the hollow frame. The hollow frame is fixedly installed with each group of sliding rods. The inner wall of the hollow frame is evenly provided with air intakes. One side of the hollow frame is evenly fixedly equipped with telescopic tubes. The other end of each group of telescopic tubes passes through the support plate and is fixedly installed with the adjacent cylinder. The two ends of each group of telescopic tubes are respectively connected to the adjacent cylinder and the interior of the hollow frame.

[0009] Furthermore, each of the rotating rods in each group has a perforated circular plate fixedly installed on its rod wall, and each of the cylindrical rods in each group is sleeved on the outer wall of the adjacent perforated circular plate. A piston plate is provided in contact with one side of the perforated circular plate. The piston plate is sleeved on the rod wall of the rotating rod and is axially slidably installed in the inner cavity of the cylindrical rod. A spring is fixedly installed between the piston plate and the inner cavity wall of the cylindrical rod.

[0010] Furthermore, magnet blocks are installed on the opposite sides of the perforated circular plate and the piston plate, and the two magnet blocks are magnetically attracted to each other, with the magnetic attraction between the two magnet blocks being greater than the elastic force of the spring when it is stretched to its maximum length.

[0011] Furthermore, a top seat is placed on the top of the rail body. The bottom of the top seat has evenly spaced slots on the two curved surfaces near the top of the rail body. Each set of slots has a ball caster slidably installed inside. The bottom of each set of ball casters is in rolling contact with the adjacent curved surface of the top of the rail body. A spring is fixedly installed between each set of ball casters and the inner cavity of the adjacent slot. An electromagnet is installed at the center of the bottom of the top seat and is magnetically attached to the top of the rail body.

[0012] Furthermore, connecting brackets are slidably installed on both sides of the top seat, and a threaded rod is rotatably installed on the top of the top seat. Both connecting brackets are threadedly installed with the threaded rod. The connecting brackets on the same side are fixedly installed with the base, and the top seat is fixedly installed with the support plate.

[0013] Furthermore, a screw is threadedly installed on the support plate, and the other end of the screw passes through the hollow sleeve and is rotatably mounted with a rotating plate, which abuts against the body of the current equalization copper busbar.

[0014] Furthermore, a leak-proof strip is installed on the side of the current equalization copper bus body near the rail body to prevent liquid brazing filler metal from flowing out of the brazing bonding surface or into the mounting hole thereon. The brazing surface of the current equalization copper bus body is roughened.

[0015] Furthermore, the axial length of each spring after compression is equal to the distance between the last circular frame and the two opposing sides of the push plate, and the distance between the last circular frame and the two opposing sides of the equalizing copper busbar body is equal to the distance between the hollow sleeve frame and the two opposing sides of the rail body web.

[0016] A brazing process for a low-temperature brazing equipment for a current-equalizing copper busbar on steel rails includes the following steps:

[0017] S1: Clean the area of ​​the rail body to be welded, move the equipment to the welding position, turn on the electromagnet to attract the top of the rail body, and make the base fit against the bottom wall of the rail web.

[0018] S2: Place the current equalization copper bus body on the top of the base, so that its brazing surface is in contact with the rail body web, place brazing filler metal between the current equalization copper bus body and the rail body, and rotate the screw to clamp and fix it.

[0019] S3: Turn on the electric heating plate to heat and liquefy the brazing filler metal. Push the lever to make each round frame hit the equalizing copper bus body in turn, promoting the even spread of the liquid brazing filler metal. At the same time, the hollow sleeve is simultaneously fitted on the outside of the vertical side of the equalizing copper bus body, but does not contact the rail web of the rail body.

[0020] S4: After the liquid brazing filler metal is evenly spread, turn off the electric heating plate and push the pusher plate again to make the hollow sleeve frame contact the rail web of the rail body to form a heat preservation and slow cooling chamber to slow down the cooling rate.

[0021] S5: After the brazing seam has solidified, rotate the rotating rod to reset the spring and drive the piston plate to draw out hot air and introduce cold air to accelerate cooling. Then, move the equipment away.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) The present invention opens the opening by pushing the dial plate so that each T-shaped plate contacts the copper busbar body in sequence. Heat is introduced into the inner cavity of the circular frame, causing the disc-shaped bimetallic sheet to jump and flip and hit the limiting plate. Each circular frame generates vibration in sequence to promote the liquid brazing filler to fully wet and spread at the bonding interface and drive out air bubbles, significantly improving the density and bonding strength of the brazing seam, and solving the problem of poor fluidity of brazing filler at low temperature and difficulty in filling the welding interface.

[0024] (2) The present invention forms a heat-insulating and slow-cooling chamber by fitting a hollow frame around the outside of the uniform flow copper busbar and contacting the rail web of the rail body. This allows the brazed joint to cool down slowly at a controllable rate during the liquid-to-solid transition, effectively eliminating the internal stress caused by the difference in thermal expansion coefficients between copper and steel, eliminating the stress concentration source inside the brazed joint, thereby significantly improving the vibration fatigue resistance of the brazed joint and avoiding failures such as weld cracking and detachment caused by excessively rapid cooling.

[0025] (3) The present invention uses the rotating rod to make the spring reset three times and drive the piston plate to move quickly, extract the hot air between the hollow sleeve frame and the current equalization copper bus body and introduce the outside cold air, accelerate the cooling of the current equalization copper bus body, effectively shorten the construction waiting time, and facilitate the timely implementation of subsequent processes such as conductivity testing, bonding strength testing and vibration simulation sampling inspection.

[0026] (4) The present invention achieves rapid pushing and sliding guidance of the equipment on the rail by rolling cooperation between the ball caster and the top arc surface of the rail body, and achieves rapid positioning, fixing and release of the equipment by electromagnet adsorption on the top of the rail body, which facilitates rapid transfer between different welding stations and greatly improves on-site construction efficiency and equipment operation convenience. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0028] Figure 2 This is a first cross-sectional view of the present invention.

[0029] Figure 3 For the present invention Figure 2 Enlarged view of the structure of section A in the middle.

[0030] Figure 4 This is a schematic diagram of the structure of each group of circular frames in this invention.

[0031] Figure 5 This is a cross-sectional view of the circular frame of the present invention.

[0032] Figure 6 This is a second cross-sectional view of the present invention.

[0033] Figure 7 This is a bottom view of the hollow frame of the present invention.

[0034] Figure 8 This is a schematic diagram of the anti-leakage strip of the present invention.

[0035] Figure 9 This is an overall side view of the present invention.

[0036] Figure 10 This is a schematic diagram of the process flow of the present invention.

[0037] Explanation of the labels in the diagram: 1. Rail body; 101. Top mount; 102. Connecting frame; 103. Base; 104. Current equalization copper busbar body; 105. Electric heating plate; 106. Threaded rod; 107. Support plate; 108. Leak-proof strip; 2. Push plate; 201. Circular frame; 202. Spring 1; 203. Opening; 204. Limiting plate; 205. T-shaped plate; 206. Spring 2; 207. Disc-shaped bimetallic strip; 208. Sliding rod; 209. Rotating rod; 210. Cylinder; 211. Perforated circular plate; 212. Air vent; 213. Piston plate; 214. Magnet block; 215. Spring 3; 216. Hollow sleeve frame; 217. Air intake port; 218. Telescopic tube; 219. Paddle plate; 3. Grooving; 301. Ball bearing caster; 302. Spring 4; 303. Electromagnet; 4. Screw; 401. Rotating plate. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0039] Please see Figures 1 to 9 A low-temperature brazing equipment for a current equalization copper busbar for rails includes a rail body 1. Bases 103 adapted to the bottom wall of the rail web are provided on both sides of the rail body 1. A current equalization copper busbar body 104 and an electric heating plate 105 are respectively provided on the two bases 103. A support plate 107 is provided on one side of the rail body 1. Slide rods 208 are evenly slidably installed on the support plate 107. A rotating rod 209 is rotatably installed at one end of each slide rod 208. A lever 219 is rotatably installed between each rotating rod 209.

[0040] The striking assembly includes a push plate 2 fixedly installed at the other end of each slide bar 208. Multiple circular frames 201 are arranged sequentially along the length of the other side of the push plate 2. The last circular frame 201 is fixedly installed with the push plate 2. Springs 202 are installed between the remaining circular frames 201 and the push plate 2. An opening 203 is opened on the other side of the circular frame 201. A T-shaped plate 205 is slidably installed in the opening 203. A limiting plate 204 opposite to the T-shaped plate 205 is fixedly installed in the circular frame 201. A spring 206 is arranged between the limiting plate 204 and the T-shaped plate 205. A disc-shaped bimetallic strip 207 is installed in the circular frame 201. The concave side of the disc-shaped bimetallic strip 207 faces the limiting plate 204.

[0041] By adopting the above technical solution, firstly, the equipment uses an electric heating plate 105 as a heat source, the power of which can be selected in the range of 1kW to 5kW, preferably 2kW; the brazing filler metal can be tin-based, silver-containing tin-based, or Sn-Zn cadmium-free brazing filler metal, preferably tin-based soft brazing filler metal, with a liquidus temperature of 250℃ to 260℃; the flux can be resin-based (rosin-based), zinc chloride-based, or organic acid-based flux, preferably resin-based (rosin-based), with an activity temperature range of 127℃ to 315℃, and preferably in paste form; the operating temperature of the disc-shaped bimetallic strip 207 can be selected in the range of 250℃ to 350℃, preferably 300℃; during operation, the electric heating plate 105 is turned on to heat the rail web of the rail body 1 at a low temperature, and the heating temperature is controlled at 3℃. Below 50℃, avoid affecting the metallographic structure and mechanical properties of the rail base material; the temperature is transferred to the equalizing copper busbar body 104, so that the brazing filler metal between the equalizing copper busbar body 104 and the rail web of the rail body 1 is heated and gradually liquefied. The liquefaction state of the brazing filler metal can be confirmed by the digital display temperature control of the electric heating plate 105 (it can be further ensured that the liquefaction is sufficient by holding the temperature for 30s to 60s); the circular frame 201 and the T-shaped plate 205 are both made of heat insulation material. The operator pushes the lever 219 to drive the slide bar 208 to move towards the equalizing copper busbar body 104 through the rotating rod 209. The slide bar 208 will drive the circular frame 201 on it to move towards the equalizing copper busbar body 104 through the push plate 2. The circular frame 201 located at the front will drive the T-shaped plate 205 inside it to contact one side of the equalizing copper busbar body 104 first.

[0042] When the T-shaped plate 205 contacts the current equalization copper busbar body 104 and the push plate 2 continues to move, the T-shaped plate 205 is limited. The push plate 2 will push the circular frame 201 to contact the vertical side wall of the current equalization copper busbar body 104 through the spring 202. The T-shaped plate 205 will move into the circular frame 201 and squeeze the spring 206. At this time, the opening 203 is opened, and the temperature will be transferred to the circular frame 201 through the opening 203. At this time, the disc-shaped bimetallic strip 207 will be heated and its temperature will rise. Its center will suddenly jump and flip, changing from the initial right convex and left concave to left convex and right concave. At this time, the disc-shaped bimetallic strip 207 can hit the limiting plate 204. The force generated by the impact will be transferred from the circular frame 201 to the current equalization copper busbar body 104. The push plate 2 continues to push the push plate 2 towards the current equalization copper busbar body 104. As the busbar body 104 moves in a certain direction, the rear sets of circular frames 201 will sequentially contact the busbar body 104 and impact it, causing vibration. The springs 202 will also be compressed accordingly until the last circular frame 201 contacts the busbar body 104. Through the sequentially arranged circular frames 201, the busbar body 104 can be impacted and vibrated sequentially. Through the above-mentioned multi-stage sequential impact, the vibration energy can be effectively used to promote the wetting and spreading of liquid brazing filler metal on the interface between the busbar body 104 and the rail body 1, remove residual air bubbles in the weld, significantly improve the density and bonding strength of the brazing filler metal, and solve the problem of poor fluidity of liquid brazing filler metal under low temperature conditions and difficulty in fully filling the welding interface under capillary action.

[0043] like Figure 3 and Figure 7 As shown, one side of the support plate 107 is fixedly equipped with cylinders 210 in the same number as the sliding rods 208. Each set of sliding rods 208 is slidably installed with the adjacent cylinders 210. Each set of sliding rods 208 is sleeved on the outer wall of the rotating rod 209. A hollow frame 216 is provided on the outer side of the push plate 2. The side wall of the hollow frame 216 is evenly provided with air vents 212, and the air vents 212 are not connected to the inside of the wall of the hollow frame 216. The hollow frame 216 is fixedly installed with each set of sliding rods 208. The inner wall of the hollow frame 216 is evenly provided with air intakes 217. One side of the hollow frame 216 is evenly fixedly equipped with telescopic tubes 218. The other end of each set of telescopic tubes 218 passes through the support plate 107 and is fixedly installed with the adjacent cylinders 210. The two ends of each set of telescopic tubes 218 are respectively connected to the adjacent cylinders 210 and the inside of the hollow frame 216.

[0044] Each set of rotating rods 209 has a perforated circular plate 211 fixedly installed on its rod wall. Each set of cylinders 210 is sleeved on the outer wall of the adjacent perforated circular plate 211. A piston plate 213 is provided in contact with one side of the perforated circular plate 211. The piston plate 213 is sleeved on the rod wall of the rotating rod 209 and is axially slidably installed in the inner cavity of the cylinder 210. A spring 215 is fixedly installed between the piston plate 213 and the inner cavity wall of the cylinder 210.

[0045] Magnet blocks 214 are installed on opposite sides of the perforated circular plate 211 and the piston plate 213. The two magnet blocks 214 are magnetically attached, and the magnetic attraction between the two magnet blocks 214 is greater than the elastic force of the spring 3 215 when it is stretched to its maximum length.

[0046] By adopting the above technical solution, when the push plate 219 moves the slide rod 208 towards the direction of the equalizing copper busbar body 104 via the rotating rod 209, the slide rod 208 will drive the hollow sleeve 216 to move synchronously. When the last side round frame 201 contacts the vertical side wall of the equalizing copper busbar body 104, the hollow sleeve 216 will contact the rail web of the rail body 1 and be sleeved on the outside of the equalizing copper busbar body 104. After the liquid brazing filler metal is evenly spread on the brazing side of the equalizing copper busbar body 104 and the rail body 1, the electric heating plate 105 is turned off to stop heating. At this time, the rail body 1, the equalizing copper busbar body 104 and the liquid brazing filler metal will gradually cool down. Since copper has good heat dissipation, the hollow sleeve 216 can prevent the equalizing copper busbar from cooling down. The drain body 104 and the liquid brazing filler metal are in direct contact with the outside air to prevent excessively rapid cooling. The ventilation port 212 enables natural interaction between the outside air and the gas inside the hollow frame 216. Through the physical barrier and heat preservation effect of the hollow frame 216, the brazed joint achieves gradient and slow cooling during the liquid-to-solid transition. The temperature drops slowly and naturally, eliminating the need for manual intervention in the traditional process of gradually reducing the output power of the electric heating plate 105, thus simplifying the operation process. At the same time, it can effectively eliminate the internal stress caused by the difference in thermal expansion coefficients between copper and steel, and eliminate the stress concentration source inside the brazed joint, thereby significantly improving the vibration fatigue resistance of the brazed joint and avoiding failures such as weld cracking and detachment caused by excessively rapid cooling.

[0047] Initially, spring 215 is in a naturally straight state. At this time, the two magnets 214 are attracted together. The lever 219 moves the rotating rod 209 towards the base 103, simultaneously moving the perforated circular plate 211. As the perforated circular plate 211 moves, it is attracted by the magnets 214, causing the piston plate 213 to move synchronously and stretching spring 215. After the liquid brazing filler metal cools and completely solidifies in the brazing seam, rotating one set of rotating rods 209 causes the perforated circular plate 211 to rotate. The rotation of the perforated circular plate 211 causes the magnets 214 to move accordingly. At this point, the two magnets 214 separate, and the magnetic attraction is gone. The spring... Under the action of spring 215, spring 215 will quickly drive piston plate 213 to move to the initial position when it returns to its initial state. Piston plate 213 will generate instantaneous suction force on telescopic tube 218 through perforated circular plate 211 and cylinder 210. Telescopic tube 218 will quickly draw air between hollow sleeve frame 216 and current equalization copper bus body 104 through each set of air intake ports 217. This can quickly draw out the hot air between hollow sleeve frame 216 and current equalization copper bus body 104. At the same time as the gas is drawn out, cold air from the outside will be drawn in through air exchange port 212 to accelerate the cooling of current equalization copper bus body 104, shorten the waiting time, and facilitate subsequent processes such as expansion pin installation, continuity testing, and joint strength testing.

[0048] When the hollow frame 216 needs to be reset, the hollow frame 216 can be moved away from the equalizing copper bus body 104 by pulling the lever 219. During this process, the rotating rods 209 of the other groups can be rotated to reset the piston plate 213 inside and perform adsorption again, so as to draw out the hot air outside the equalizing copper bus body 104 and introduce external gas for cooling. This avoids the accumulation of local residual heat due to incomplete single air intake, thereby further improving the cooling efficiency and uniformity and shortening the overall cooling waiting time.

[0049] When the hollow frame 216 moves, the telescopic tube 218 will extend and retract accordingly. Each telescopic tube 218 is equipped with a one-way valve. The cylinder 210 can only draw in air through the telescopic tube 218 and exhaust air through the through hole on it. The side of the hollow frame 216 near the equalizing copper busbar body 104 is set with magnetic attraction. When the hollow frame 216 contacts the rail body 1, it can be magnetically attracted to the rail web of the rail body 1. This can avoid the need for the operator to keep pushing the lever 219 during the cooling process of the liquid brazing filler metal, thus reducing manpower. The hollow frame 216 is made of a visual material, which can clearly show the solidification changes of the liquid brazing filler metal.

[0050] like Figure 2 and Figure 6As shown, a top seat 101 is placed on the top of the rail body 1. The bottom of the top seat 101 is evenly provided with slots 3 on the two sides of the top of the rail body 1. Each set of slots 3 has a ball caster 301 slidably installed in its inner cavity. The bottom of each set of ball casters 301 is in rolling contact with the adjacent side arc surface of the top of the rail body 1. Each set of ball casters 301 is fixedly installed between the inner cavity of the adjacent slot 3 and the inner cavity of the adjacent slot. An electromagnet 303 is installed at the bottom center of the top seat 101. The electromagnet 303 is magnetically attached to the top of the rail body 1.

[0051] Connecting brackets 102 are slidably installed on both sides of the top seat 101, and threaded rods 106 are rotatably installed on the top of the top seat 101. Both connecting brackets 102 are threadedly installed with the threaded rods 106. Connecting brackets 102 and base 103 on the same side are fixedly installed, and the top seat 101 is fixedly installed with the support plate 107.

[0052] A screw 4 is threaded onto the support plate 107. The other end of the screw 4 passes through a hollow sleeve 216 and is rotatably mounted with a rotating plate 401. The rotating plate 401 abuts against the current equalization copper bus body 104.

[0053] By adopting the above technical solution, the threaded rod 106 can be rotated in both directions to drive the connecting frames 102 on both sides to move closer or further away synchronously. During initial installation, rotating the threaded rod 106 causes the two connecting frames 102 to move further away. As the two connecting frames 102 move, they will drive the base 103 to move synchronously. The distance between the two bases 103 should be greater than the top of the rail body 1. Then, the device is inserted from the top of the rail body 1. In the initial state, the electromagnet 303 is in the closed state, and the spring 302 is initially placed on the lower side of the top seat 101. Through the cooperation and guidance of the ball caster 301 and the top arc surface of the rail body 1, the device can be quickly positioned and smoothly pushed on the rail body 1, which is convenient for transfer between different welding stations.

[0054] At this point, there are gaps between the top seat 101 and the top of the rail body 1, and between the base 103 and the bottom wall of the rail body 1. This allows the device to slide along the length of the rail body 1. When brazing is required, the surface of the rail to be brazed is cleaned to expose the pure metal substrate. Then, the device is moved to its position, and the threaded rod 106 is rotated to bring the two connecting frames 102 closer together, causing the two bases 103 to move to the sides of the rail body 1. Then, the electromagnet 303 is activated. When energized, the electromagnet 303 generates magnetic force, causing it to adhere to the top of the rail body 1, achieving rapid fixation and improving on-site construction efficiency. During the adsorption process… In the process, the electromagnet 303 will drive the top seat 101 to move downward and stick to the top of the rail body 1. At the same time, the connecting frame 102 will drive the base 103 to stick to the bottom wall of the rail body 1. The ball caster 301 will squeeze the spring 4 302 to retract into the slot 3. Then, flux is applied to the brazing side of the current equalization copper bus body 104 to remove the interface oxide film and place special low temperature brazing material. Then, the current equalization copper bus body 104 is placed on the top of the base 103, so that its brazing side is in contact with the brazing side of the rail body 1. Then, the screw 4 is rotated to drive the rotating plate 401 to move towards the current equalization copper bus body 104 and clamp it. Then, the electric heating plate 105 is turned on to realize the low temperature brazing work.

[0055] After low-temperature brazing is completed, rotate the threaded rod 106 to move the two bases 103 away from the bottom of the current equalization copper busbar body 104. Rotate the screw 4 to move the rotating plate 401 away from the current equalization copper busbar body 104 and control the electromagnet 303 to close, thus achieving the reset operation. Then, push the device to the next brazing position. The mounting holes on the vertical side of the current equalization copper busbar body 104 are used to install screws or expansion pins, and the mounting holes on the horizontal side are used to install return cables. The thickness of each branch of the current equalization copper busbar body 104 is differentiated according to the current distribution law to eliminate current concentration and achieve full-area current equalization.

[0056] like Figure 6 and Figure 8 As shown, a leak-proof strip 108 is installed on the side of the current equalization copper bus body 104 near the rail body 1 to prevent liquid brazing filler metal from flowing out of the brazing bonding surface or into the mounting hole thereon. The brazing surface of the current equalization copper bus body 104 is roughened.

[0057] The axial length of each spring 202 after compression is equal to the distance between the two opposing sides of the last side circular frame 201 and the push plate 2. The distance between the two opposing sides of the last side circular frame 201 and the equalizing copper busbar body 104 is equal to the distance between the two opposing sides of the hollow sleeve frame 216 and the rail web of the rail body 1.

[0058] By adopting the above technical solution, the anti-leakage strip 108 can prevent liquid brazing filler metal from flowing out of the brazing mating surface between the current equalizing copper bus body 104 and the rail body 1, avoiding the loss of brazing filler metal and resulting in insufficient welding material. At the same time, it prevents liquid brazing filler metal from flowing into the mounting holes on the vertical side of the current equalizing copper bus body 104 and clogging the holes, ensuring the smooth progress of subsequent expansion bolt installation and cable connection operations. In addition, the top of the anti-leakage strip 108 is open, allowing observation of the liquefaction state of the brazing filler metal. After the brazing surface of the current equalizing copper bus body 104 is roughened, the contact area between the brazing filler metal and the current equalizing copper bus body 104 can be increased, improving the wettability, spreadability and adhesion of the brazing filler metal, thereby strengthening the bonding strength of the brazed joint.

[0059] The brazing process of a low-temperature brazing equipment for rails with a current-equalizing copper busbar, such as... Figure 10 As shown, it includes the following steps:

[0060] S1: Clean the area to be welded on the rail body 1, move the equipment to the welding position, turn on the electromagnet 303 to attract the top of the rail body 1, and make the base 103 fit against the bottom wall of the rail web.

[0061] S2: Place the current equalization copper bus body 104 on top of the base 103, so that its brazing surface is in contact with the rail web of the rail body 1, place brazing filler metal between the current equalization copper bus body 104 and the rail body 1, and rotate the screw 4 to clamp and fix it.

[0062] S3: Turn on the electric heating plate 105 to heat and liquefy the brazing filler metal. Push the lever 219 to make each round frame 201 hit the equalizing copper bus body 104 in sequence to promote the even spread of the liquid brazing filler metal. At the same time, the hollow sleeve 216 is simultaneously sleeved on the outside of the vertical side of the equalizing copper bus body 104, but does not contact the rail web of the rail body 1.

[0063] S4: After the liquid brazing filler metal is evenly spread, turn off the electric heating plate 105 and push the push plate 2 again so that the hollow sleeve 216 contacts the rail web of the rail body 1 to form a heat preservation and slow cooling chamber to slow down the cooling rate.

[0064] S5: After the brazing seam has solidified, rotate the rotating rod 209 to reset the spring 215, which will drive the piston plate 213 to draw out hot air and introduce cold air to accelerate cooling. Then, move the equipment away.

[0065] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A low-temperature brazing device for a current-equalizing copper busbar on a rail, comprising a rail body (1), characterized in that: The rail body (1) is provided with bases (103) on both sides that are adapted to the bottom wall of the rail web. The two bases (103) are respectively provided with a current equalization copper bus body (104) and an electric heating plate (105). A support plate (107) is provided on one side of the rail body (1). Slide rods (208) are evenly slidably installed on the support plate (107). A rotating rod (209) is rotatably installed at one end of each slide rod (208). A lever plate (219) is rotatably installed between each rotating rod (209). The striking assembly includes a push plate (2) fixedly installed at the other end of each slide bar (208). A plurality of circular frames (201) are arranged sequentially along the length of the other side of the push plate (2). The last circular frame (201) is fixedly installed with the push plate (2). A spring (202) is installed between the remaining circular frames (201) and the push plate (2). An opening (203) is opened on the other side of the circular frame (201). A T-shaped plate (205) is slidably installed in the opening (203). A limiting plate (204) opposite to the T-shaped plate (205) is fixedly installed in the circular frame (201). A spring (206) is arranged between the limiting plate (204) and the T-shaped plate (205). A disc-shaped bimetallic strip (207) is installed in the circular frame (201). The concave side of the disc-shaped bimetallic strip (207) faces the limiting plate (204).

2. The low-temperature brazing equipment for a current-equalizing copper busbar for rails according to claim 1, characterized in that: One side of the support plate (107) is fixedly equipped with cylinders (210) in the same number as the sliding rods (208). Each set of sliding rods (208) is slidably installed with the adjacent cylinder (210). Each set of sliding rods (208) is sleeved on the outer wall of the rotating rod (209). A hollow frame (216) is provided on the outer side of the push plate (2). Ventilation ports (212) are evenly opened on the side wall of the hollow frame (216), and the ventilation ports (212) are not connected to the interior of the wall of the hollow frame (216). The hollow frame (216) is fixedly installed with each set of sliding rods (208). The inner wall of the hollow frame (216) is evenly provided with air intakes (217). A telescopic tube (218) is evenly fixedly installed on one side of the hollow frame (216). The other end of each set of telescopic tubes (218) passes through the support plate (107) and is fixedly installed with the adjacent cylinder (210). The two ends of each set of telescopic tubes (218) are respectively connected to the adjacent cylinder (210) and the hollow frame (216).

3. The low-temperature brazing equipment for a current-equalizing copper busbar for rails according to claim 2, characterized in that: Each of the rotating rods (209) has a perforated circular plate (211) fixedly installed on its rod wall. Each of the cylindrical tubes (210) is sleeved on the outer wall of the adjacent perforated circular plate (211). A piston plate (213) is provided in contact with one side of the perforated circular plate (211). The piston plate (213) is sleeved on the rod wall of the rotating rod (209) and is axially slidably installed in the inner cavity of the cylindrical tube (210). A spring (215) is fixedly installed between the piston plate (213) and the inner cavity wall of the cylindrical tube (210).

4. The low-temperature brazing equipment for a current-equalizing copper busbar for rails according to claim 3, characterized in that: Magnet blocks (214) are installed on the opposite sides of the perforated circular plate (211) and the piston plate (213). The two magnet blocks (214) are magnetically attached, and the magnetic attraction between the two magnet blocks (214) is greater than the elastic force of the spring three (215) when it is stretched to its maximum length.

5. The low-temperature brazing equipment for a current-equalizing copper busbar for rails according to claim 4, characterized in that: A top seat (101) is placed on the top of the rail body (1). The bottom of the top seat (101) is evenly provided with slots (3) on both sides of the top of the rail body (1). Each set of slots (3) is slidably installed with ball casters (301). The bottom of each set of ball casters (301) is in rolling contact with the adjacent side arc surface of the top of the rail body (1). Each set of ball casters (301) is fixedly installed with a spring (302) between it and the inner cavity of the adjacent slot (3). An electromagnet (303) is installed at the bottom center of the top seat (101). The electromagnet (303) is magnetically attached to the top of the rail body (1).

6. The low-temperature brazing equipment for a current-equalizing copper busbar for rails according to claim 5, characterized in that: Connecting brackets (102) are slidably installed on both sides of the top seat (101). A threaded rod (106) is rotatably installed on the top of the top seat (101). Both connecting brackets (102) are threadedly installed with the threaded rod (106). The connecting brackets (102) on the same side and the base (103) are fixedly installed. The top seat (101) is fixedly installed with the support plate (107).

7. The low-temperature brazing equipment for a current-equalizing copper busbar for rails according to claim 6, characterized in that: A screw (4) is threaded onto the support plate (107). The other end of the screw (4) passes through the hollow sleeve frame (216) and is rotatably mounted with a rotating plate (401). The rotating plate (401) abuts against the current equalization copper bus body (104).

8. The low-temperature brazing equipment for a current-equalizing copper busbar for rails according to claim 7, characterized in that: The current equalization copper bus body (104) is equipped with a leak-proof strip (108) on the side near the rail body (1) to prevent liquid brazing filler from flowing out of the brazing bonding surface or into the mounting hole thereon. The brazing surface of the current equalization copper bus body (104) is roughened.

9. The low-temperature brazing equipment for a current-equalizing copper busbar for rails according to claim 8, characterized in that: The axial length of each spring (202) after compression is equal to the distance between the last circular frame (201) and the push plate (2) on opposite sides. The distance between the last circular frame (201) and the equalizing copper busbar body (104) on opposite sides is equal to the distance between the hollow sleeve frame (216) and the rail web of the rail body (1) on opposite sides.

10. A brazing process applicable to the low-temperature brazing equipment for a current-equalizing copper busbar as described in claim 9, characterized in that: Includes the following steps: S1: Clean the rail body (1) to be welded, push the equipment to the position to be welded, turn on the electromagnet (303) to attract the top of the rail body (1), and make the base (103) fit against the bottom wall of the rail waist. S2: Place the equalizing copper bus body (104) on the top of the base (103) so that its brazing surface is in contact with the rail web of the rail body (1), place brazing material between the equalizing copper bus body (104) and the rail body (1), and rotate the screw (4) to clamp and fix it. S3: Turn on the electric heating plate (105) to heat and liquefy the brazing filler metal, push the lever (219) to make each round frame (201) hit the equalizing copper bus body (104) in turn, promote the even spread of liquid brazing filler metal, and at the same time, the hollow sleeve frame (216) is simultaneously sleeved on the outside of the vertical side of the equalizing copper bus body (104), but does not contact the rail web of the rail body (1); S4: After the liquid brazing filler metal is evenly spread, turn off the electric heating plate (105) and push the push plate (2) again so that the hollow sleeve frame (216) contacts the rail web of the rail body (1) to form a heat preservation and slow cooling chamber to slow down the cooling rate. S5: After the brazing seam solidifies, rotate the rotating rod (209) to reset the spring three (215) and drive the piston plate (213) to draw out the hot air and introduce the cold air to accelerate the cooling. Then push the equipment away.

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