Friction-assisted rail flash welding apparatus and method

Abstract

This invention discloses a friction-assisted flash welding device and method for steel rails, comprising a stationary frame, a moving frame, a fixture, a drive device, an extrusion end electrode, a moving frame electrode, a friction extruder, a stationary frame electrode, an upsetting device, and a controller. The friction extruder is detachably mounted on the fixture and includes a first contact surface and a second contact surface. The first contact surface is used to contact a first welding surface, and the second contact surface is used to contact a second welding surface. The drive device drives the fixture and the friction extruder to reciprocate together along a length direction perpendicular to the first rail to be welded. The first rail to be welded includes a first welding end, and the moving frame electrode is attached to the first welding end. The second rail to be welded includes a second welding end, and the stationary frame electrode is attached to the second welding end. The extrusion end electrode is attached to the friction extruder. The friction-assisted flash welding device and method for steel rails provided by this invention improve the mechanical properties and welding quality of the welded joint.

Description

Technical Field

[0001] This invention relates to the field of flash welding technology, and more specifically, to a friction-assisted flash welding device and method for rails. Background Technology

[0002] Currently, the main rail welding methods are flash welding, gas pressure welding, and aluminothermic welding. Welds often have defects such as decarburization layer, softening layer, and gray spots. Due to the large heat input during welding, the grains in the weld and heat-affected zone are relatively coarse. For flash welded and gas pressure welded joints, my country's railway standards require normalizing treatment after welding, which can improve the joint performance to some extent, but it cannot eliminate welding defects such as decarburization softening layer and gray spots. Especially for new materials such as U20Mn bainitic rails, current flash welding cannot achieve qualified welded joints.

[0003] The biggest difference between friction welding and flash welding, gas pressure welding, and aluminothermic welding is that during the entire welding process, the temperature reached by the metals being welded does not reach their melting point; that is, the metals achieve a forged-like solid-state connection in a thermoplastic state. It features high-quality weld joints, no decarburized softening layer or inclusions, weld strength equal to that of the base material, high welding efficiency, stable and consistent quality, and the ability to weld dissimilar materials.

[0004] Due to equipment limitations, the largest friction welding equipment currently available can only weld rails with a contact area of ​​less than 4000 mm. 2 The existing technology cannot meet the requirements for rail welding, and developing larger-tonnage friction welding equipment is technically difficult and requires a large initial investment. Among the existing technologies, patent CN109986189A discloses a process for refining the grain size of rail flash welds, and patent CN112171103A discloses a rail welding machine and method for refining weld grain size. Both focus on the problem of refining weld grain size, but neither can expel the weld metal from the weld, thus failing to eliminate the softened layer caused by the burning of decarburized alloying elements at the weld, nor can it expel defects such as internal oxide inclusions from the weld, thereby failing to improve the mechanical properties and welding quality of the welded joint. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a friction-assisted flash welding device and method for rails to improve the mechanical properties and welding quality of the welded joint.

[0006] To achieve the above objectives, the present invention provides a friction-assisted flash welding device for steel rails, comprising a stationary frame, a moving frame, a clamp, a driving device, an extrusion end electrode, a moving frame electrode, a friction extruder, a stationary frame electrode, an upsetting device, and a controller, wherein: the stationary frame is used to clamp or release a first steel rail to be welded, the first steel rail to be welded including a first welding surface; the moving frame is used to clamp or release a second steel rail to be welded, the second steel rail to be welded including a second welding surface; the friction extruder is detachably mounted on the clamp, the friction extruder including a first contact surface and a second contact surface facing away from each other, the first contact surface being used to contact the first welding surface, the second contact surface being used to contact the second welding surface; the driving device drives the clamp and the friction extruder together along a path perpendicular to the ground. The first rail to be welded reciprocates along its length; the first rail to be welded includes a first welding end, and the moving frame electrode is fitted onto the first welding end; the second rail to be welded includes a second welding end, the second welding end and the first welding end are arranged opposite each other, and the stationary frame electrode is fitted onto the second welding end; both the moving frame electrode and the stationary frame electrode are used to connect to the positive terminal of the welding power source; the extrusion end electrode is fitted onto the friction extruder, and the extrusion end electrode is used to connect to the negative terminal of the welding power source; the upsetting device is used to drive the moving frame to reciprocate along a direction close to or away from the stationary frame; the controller controls the operation of the driving device, the upsetting device, the stationary frame and the moving frame, and the controller controls the on / off state of the welding power source.

[0007] Optionally, the fixture is provided with a snap-fit ​​groove, and the friction extruder is snap-fitted into the snap-fit ​​groove.

[0008] Optionally, the moving electrode is fitted onto the rail web at the first welding end, and the stationary electrode is fitted onto the rail web at the second welding end.

[0009] Optionally, the driving device includes a first cylinder and a first piston rod drivenly connected to the first cylinder. The first piston rod is detachably mounted on the clamp, and the first piston rod drives the clamp and the friction extruder to reciprocate together along the length direction perpendicular to the first rail to be welded.

[0010] Optionally, the extrusion end electrode includes a conductive bus, one end of which is mounted on the extrusion end electrode, and the other end of which is connected to the welding power source.

[0011] Optionally, the upsetting device includes a second cylinder and a second piston rod drivenly connected to the second cylinder. The second cylinder is fixedly mounted on the stationary frame, and the second piston rod is mounted on the moving frame. The second piston rod drives the moving frame to reciprocate in a direction close to or away from the stationary frame.

[0012] Optionally, the moving frame electrode is provided with multiple moving frame cooling air outlets, the stationary frame electrode is provided with multiple stationary frame cooling air outlets, and the extrusion end electrode is provided with multiple extrusion end cooling air outlets. The multiple moving frame cooling air outlets, the multiple stationary frame cooling air outlets, and the multiple extrusion end cooling air outlets are all used to connect to an air compressor, and the controller controls the start and stop of the air compressor.

[0013] Optionally, the friction extrusion part is made of U71Mn or a nickel-based high-temperature alloy.

[0014] Based on the same inventive concept, this invention also provides a method for friction-assisted flash welding of rails, using the friction-assisted flash welding equipment described in any of the foregoing technical solutions, comprising the following steps: Step 1: Removing loose rust, oil, and scale from the first and second welding surfaces using a rust remover; Step 2: The controller controls the moving frame to clamp the first rail to be welded, the first rail to be welded including a first welding surface; the controller controls the stationary frame to clamp the second rail to be welded, the second rail to be welded including a second welding surface; the friction extruder can be... The friction extruder is detachably mounted on the fixture. It includes a first contact surface and a second contact surface facing away from each other. The first contact surface is used to contact the first welding surface, and the second contact surface is used to contact the second welding surface. Step three: The first rail to be welded includes a first welding end. The moving electrode is attached to the first welding end. The second rail to be welded includes a second welding end, which is opposite to the first welding end. The stationary electrode is attached to the second welding end. Both the moving electrode and the stationary electrode are used to connect to the positive terminal of the welding power source. The extrusion end electrode... The components are fitted onto the friction extruder, and the extrusion end electrode is used to connect to the negative terminal of the welding power source; Step four: The controller controls the welding power source to turn on, and flash welding is performed between the first welding surface and the first mating surface, and between the second welding surface and the second mating surface, until a thin liquid film is formed on both the first welding surface and the second welding surface. The controller then controls the welding power source to turn off, stopping the flash welding; Step five: The controller controls the drive device to turn on, so that the drive device drives the fixture and the friction extruder together along the length direction perpendicular to the first rail to be welded. Reciprocating motion; Step 6: After the liquid metal, inclusions and oxides at the first welding surface and the second welding surface are completely extruded, the controller controls the drive device to move, so that the clamp and the friction extruder move away from the first welding surface and the second welding surface together. The controller controls the upsetting device to move, so that the moving frame moves towards the stationary frame, rapidly increasing the upsetting pressure, and realizing the metallurgical bond between the first welding surface and the second welding surface; Step 7: When the upsetting time requirement is met, the moving frame releases the first rail to be welded, and the stationary frame releases the second rail to be welded, and the welding is completed.

[0015] Optionally, in step four, the moving frame electrode is provided with multiple moving frame cooling air outlets, the stationary frame electrode is provided with multiple stationary frame cooling air outlets, and the extrusion end electrode is provided with multiple extrusion end cooling air outlets. All of the multiple moving frame cooling air outlets, multiple stationary frame cooling air outlets, and multiple extrusion end cooling air outlets are connected to an air compressor. When flash welding is performed, the controller controls the air compressor to start, so as to cool the first welding end and the second welding end.

[0016] The friction-assisted flash welding equipment and method for steel rails provided by this invention includes a stationary frame, a moving frame, a clamp, a drive device, an extrusion end electrode, a moving frame electrode, a friction extruder, a stationary frame electrode, an upsetting device, and a controller. First, the stationary frame clamps a first rail to be welded, and the moving frame clamps a second rail to be welded. A first contact surface is attached to a first welding surface, and a second contact surface is attached to a second welding surface. Then, the moving frame electrode is attached to the first welding end, and the stationary frame electrode is attached to the second welding end. Both the moving frame electrode and the stationary frame electrode are connected to the positive terminal of the welding power source. The extrusion end electrode is attached to the friction extruder and connected to the negative terminal of the welding power source. Finally, the controller activates the welding power source, and welding is performed between the first welding surface and the first contact surface, and between the second welding surface and the second contact surface. Flash welding is performed between the first and second weld surfaces until a thin liquid film is formed on both surfaces. The controller then cuts off the welding power, stopping the flash welding. At this point, the controller activates the drive unit, causing the clamp and friction extruder to reciprocate along a length perpendicular to the first weld rail. Once the liquid metal, inclusions, and oxides at the first and second weld surfaces are completely extruded, the controller activates the drive unit, moving the clamp and friction extruder away from the first and second weld surfaces. The controller then activates the upsetting device, moving the moving frame closer to the stationary frame to rapidly increase the upsetting pressure, achieving a metallurgical bond between the first and second weld surfaces. After the upsetting time requirement is met, the moving frame releases the first weld rail, and the stationary frame releases the second weld rail, completing the welding. During the flash welding process, the reciprocating friction of the friction extruder against the first and second weld surfaces extrudes the liquid metal, impurities, and oxides generated during flash welding, thereby improving the mechanical properties and welding quality of the weld joint. Attached Figure Description

[0017] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, which will help to understand the purpose and advantages of the present invention, wherein:

[0018] Figure 1 This is a schematic diagram of the structure of a friction-assisted rail flash welding device according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure between the drive device, fixture, friction base component, stationary electrode, moving electrode, extrusion end electrode, first rail to be welded and second rail to be welded in a friction-assisted rail flash welding equipment according to an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the structure of a friction extrusion component installed on a first rail and a second rail to be welded in a friction-assisted rail flash welding device according to an embodiment of the present invention.

[0021] Figure 4 This is a flowchart of a friction-assisted flash welding method for rails according to an embodiment of the present invention.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1: Stationary frame; 2: Moving frame; 3: Fixture; 4: Drive device; 5: Extrusion end electrode; 6: Moving frame electrode; 7: Friction extrusion part; 8: Stationary frame electrode; 9: Upsetting device; 10: First rail to be welded; 11: Second rail to be welded; 12: First welding end; 13: Second welding end; 14: First cylinder; 15: First piston rod; 16: Conductive busbar; 17: Moving frame cooling outlet; 18: Stationary frame cooling outlet; 19: Extrusion end cooling outlet. Detailed Implementation

[0024] The present invention will now be described in detail with reference to embodiments. Identical components are indicated by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0025] like Figures 1 to 3As shown, the friction-assisted flash welding equipment for rails provided by the present invention includes a stationary frame 1, a moving frame 2, a clamp 3, a drive device 4, an extrusion end electrode 5, a moving frame electrode 6, a friction extruder 7, a stationary frame electrode 8, an upsetting device 9, and a controller. The stationary frame 1 is used to clamp or release a first rail 10 to be welded, the first rail 10 including a first welding surface; the moving frame 2 is used to clamp or release a second rail 11 to be welded, the second rail 11 including a second welding surface; the friction extruder 7 is detachably mounted on the clamp 3, the friction extruder 7 including a first contact surface and a second contact surface facing away from each other, the first contact surface being used to contact the first welding surface, and the second contact surface being used to contact the second welding surface; the drive device 4 drives the clamp 3 and the friction extruder 7. Together, they reciprocate along the length direction perpendicular to the first rail to be welded 10; the first rail to be welded 10 includes a first welding end 12, and the moving frame electrode 6 is attached to the first welding end 12; the second rail to be welded 11 includes a second welding end 13, the second welding end 13 and the first welding end 12 are arranged opposite each other, and the stationary frame electrode 8 is attached to the second welding end 13. Both the moving frame electrode 6 and the stationary frame electrode 8 are used to connect to the positive terminal of the welding power source; the extrusion end electrode 5 is attached to the friction extruder 7, and the extrusion end electrode 5 is used to connect to the negative terminal of the welding power source; the upsetting device 9 is used to drive the moving frame 2 to reciprocate along the direction close to or away from the stationary frame 1; the controller controls the operation of the drive device 4, the upsetting device 9, the stationary frame 1 and the moving frame 2, and the controller controls the on and off of the welding power source.

[0026] It should be noted that the structures of the static frame 1 and the moving frame 2 in this invention are structures known to those skilled in the art, such as the structures disclosed in Chinese Patent ZL201710982469.3.

[0027] The friction-assisted flash welding equipment for rails provided by this invention includes a stationary frame 1, a moving frame 2, a clamp 3, a drive device 4, an extrusion end electrode 5, a moving frame electrode 6, a friction extruder 7, a stationary frame electrode 8, an upsetting device 9, and a controller. First, the stationary frame 1 clamps the first rail 10 to be welded, and the moving frame 2 clamps the second rail 11 to be welded. The first contact surface is attached to the first welding surface, and the second contact surface is attached to the second welding surface. Then, the moving frame electrode 6 is attached to the first welding end 12, and the stationary frame electrode 8 is attached to the second welding end 13. Both the moving frame electrode 6 and the stationary frame electrode 8 are connected to the positive terminal of the welding power source. The extrusion end electrode 5 is attached to the friction extruder 7 and connected to the negative terminal of the welding power source. Finally, the controller activates the welding power source, and welding is performed between the first welding surface and the first contact surface, and between the second welding surface and the second contact surface. Flash welding is performed between the two surfaces until a thin liquid film is formed on both the first and second welding surfaces. The controller then cuts off the welding power to stop the flash welding. At this time, the controller activates the drive device 4, causing the drive device 4 to drive the clamp 3 and the friction extruder 7 to reciprocate along the length direction perpendicular to the first rail 10 to be welded. After the liquid metal, inclusions, and oxides at the first and second welding surfaces are completely extruded, the controller activates the drive device 4 to move the clamp 3 and the friction extruder 7 away from the first and second welding surfaces. The controller then activates the upsetting device 9 to move the moving frame 2 towards the stationary frame 1, rapidly increasing the upsetting pressure and achieving metallurgical bonding between the first and second welding surfaces. Once the upsetting time requirement is met, the moving frame 2 releases the first rail 10 to be welded, and the stationary frame 1 releases the second rail 11 to be welded, completing the welding. In the above-mentioned flash welding process, the reciprocating friction of the first welding surface and the second welding surface by the friction extruder 7 extrudes the liquid metal, impurities and oxides generated on the first welding surface and the second welding surface during flash welding, thereby improving the mechanical properties and welding quality of the welded joint.

[0028] In one embodiment of the present invention, a snap-fit ​​groove is provided inside the clamp 3, and the friction extruder 7 is snap-fitted and installed in the snap-fit ​​groove. The snap-fit ​​method facilitates disassembly and improves the ease of use of the friction-assisted rail flash welding equipment.

[0029] like Figure 2 and Figure 3 As shown, the moving electrode 6 is fitted onto the rail web at the first welding end 12, and the stationary electrode 8 is fitted onto the rail web at the second welding end 13. This embodiment improves the stability of the mounting structure of the moving electrode 6 and the stationary electrode 8, thereby improving the structural stability of the friction-assisted rail flash welding equipment.

[0030] like Figure 1As shown, the driving device 4 includes a first cylinder 14 and a first piston rod 15 drivenly connected to the first cylinder 14. The first piston rod 15 is detachably mounted on the clamp 3. The first piston rod 15 drives the clamp 3 and the friction extruder 7 to reciprocate along the length direction perpendicular to the first rail to be welded 10. In this embodiment, the continuous reciprocating motion of the friction extruder 7 generates heat on both the first and second welding surfaces. The generated heat can extrude liquid metal, impurities, and oxides on the first and second welding surfaces, thereby improving the mechanical properties and welding quality of the welded joint. Using the piston rod to drive the friction extruder 7 to reciprocate is convenient to implement and the motion structure is more stable, improving the ease of use and structural stability of the friction-assisted rail flash welding equipment.

[0031] like Figure 1 and Figure 2 As shown, the extrusion end electrode 5 includes a conductive busbar 16, one end of which is mounted on the extrusion end electrode 5, and the other end of which is connected to the welding power source. In this embodiment, the conductive busbar 16 can effectively guide the current from the welding power source to the extrusion end electrode 5, improving the ease of use of the friction-assisted rail flash welding equipment.

[0032] like Figure 1 As shown, the upsetting device 9 includes a second cylinder and a second piston rod drivenly connected to the second cylinder. The second cylinder is fixedly mounted on the stationary frame 1, and the second piston rod is mounted on the moving frame 2. The second piston rod drives the moving frame 2 to reciprocate in a direction approaching or away from the stationary frame 1. In this embodiment, there can be two second cylinders and two second piston rods. The two second cylinders are mounted opposite each other on the stationary frame 1, and the two piston rods are mounted opposite each other on the moving frame 2. Using the second piston rod to drive the moving frame 2 to reciprocate in a direction approaching or away from the stationary frame 1 improves the ease of use of the friction-assisted rail flash welding equipment.

[0033] like Figure 2 and Figure 3 As shown, the moving electrode 6 is provided with multiple moving-frame cooling air outlets 17, the stationary electrode 8 is provided with multiple stationary-frame cooling air outlets 18, and the extrusion-end electrode 5 is provided with multiple extrusion-end cooling air outlets 19. All of these outlets are connected to an air compressor, and the controller controls the start and stop of the air compressor. In this embodiment, the cooling air blown from the stationary-frame cooling air outlets 18, moving-frame cooling air outlets 17, and extrusion-end cooling air outlets 19 can reduce the temperature during the flash welding process, thereby lowering the temperature of the heat-affected zone, reducing the size of the heat-affected zone of the weld joint, preventing carbide precipitation and cracking at the weld joint, and thus improving the quality of the weld joint.

[0034] In one embodiment of the present invention, the friction extrusion part 7 is made of U71Mn or a nickel-based high-temperature alloy. U71Mn is a consumable friction extrusion part 7, which can be additively manufactured; nickel-based high-temperature alloy is a tool-type friction extrusion part 7, which can be butt-welded, thus improving the applicability of friction-assisted rail flash welding equipment.

[0035] like Figures 1 to 4 As shown, based on the same inventive concept, one embodiment of the present invention also provides a friction-assisted flash welding method for rails, using the friction-assisted flash welding equipment of the aforementioned embodiment for flash welding, including the following steps: Step 1: Using a rust remover to remove loose rust, oil, and scale from the first and second welding surfaces; Step 2: The controller controls the moving frame 2 to clamp the first rail 10 to be welded, the first rail 10 including the first welding surface; the controller controls the stationary frame 1 to clamp the second rail 11 to be welded, the second rail 11 including the second welding surface, and so on. Friction extruder 7 is detachably mounted on fixture 3. Friction extruder 7 includes a first bonding surface and a second bonding surface facing away from each other. The first bonding surface is used to bond to the first welding surface, and the second bonding surface is used to bond to the second welding surface. Step 3: The first rail to be welded 10 includes a first welding end 12. The moving frame electrode 6 is bonded and mounted on the first welding end 12. The second rail to be welded 11 includes a second welding end 13. The second welding end 13 and the first welding end 12 are arranged opposite to each other. The stationary frame electrode 8 is bonded and mounted on the second welding end 13. Both the moving frame electrode 6 and the stationary frame electrode 8 are used for connecting... Connect the positive terminal of the welding power supply; attach the extrusion end electrode 5 to the friction extruder 7, and connect the extrusion end electrode 5 to the negative terminal of the welding power supply; Step 4: The controller controls the welding power supply to turn on, and flash welding is performed between the first welding surface and the first mating surface, and between the second welding surface and the second mating surface, until a thin liquid film is formed on both the first welding surface and the second welding surface. The controller then controls the welding power supply to turn off, stopping the flash welding; Step 5: The controller controls the drive device 4 to turn on, so that the drive device 4 drives the clamp 3 and the friction extruder 7 together along the first steel rail to be welded 1 perpendicular to the first rail to be welded. Step 6: After the liquid metal, inclusions and oxides at the first and second welding surfaces are completely extruded, the controller controls the drive device 4 to move, so that the clamp 3 and the friction extruder 7 move away from the first and second welding surfaces. The controller controls the upsetting device 9 to move, so that the moving frame 2 moves towards the stationary frame 1, and the upsetting pressure is increased rapidly to achieve metallurgical bonding between the first and second welding surfaces. Step 7: When the upsetting time requirement is met, the moving frame 2 releases the first rail to be welded 10, and the stationary frame 1 releases the second rail to be welded 11. The welding is completed.

[0036] The friction-assisted flash welding equipment and method for steel rails provided by this invention includes a stationary frame 1, a moving frame 2, a clamp 3, a driving device 4, an extrusion end electrode 5, a moving frame electrode 6, a friction extruder 7, a stationary frame electrode 8, an upsetting device 9, and a controller. First, the stationary frame 1 clamps the first rail to be welded 10, and the moving frame 2 clamps the second rail to be welded 11. The first contact surface is attached to the first welding surface, and the second contact surface is attached to the second welding surface. Then, the moving frame electrode 6 is attached to the first welding end 12, and the stationary frame electrode 8 is attached to the second welding end 13. Both the moving frame electrode 6 and the stationary frame electrode 8 are connected to the positive terminal of the welding power source. The extrusion end electrode 5 is attached to the friction extruder 7 and connected to the negative terminal of the welding power source. Finally, the controller activates the welding power source, and welding is performed between the first welding surface and the first contact surface, and between the second welding surface and the first contact surface. Flash welding is performed between the two mating surfaces until a thin liquid film is formed on both the first and second welding surfaces. The controller then cuts off the welding power to stop the flash welding. At this time, the controller activates the drive device 4, causing the drive device 4 to drive the clamp 3 and the friction extruder 7 to reciprocate along the length direction perpendicular to the first rail 10 to be welded. After the liquid metal, inclusions, and oxides at the first and second welding surfaces are completely extruded, the controller activates the drive device 4 to move the clamp 3 and the friction extruder 7 away from the first and second welding surfaces. The controller then activates the upsetting device 9 to move the moving frame 2 toward the stationary frame 1, rapidly increasing the upsetting pressure and achieving metallurgical bonding between the first and second welding surfaces. Once the upsetting time requirement is met, the moving frame 2 releases the first rail 10 to be welded, and the stationary frame 1 releases the second rail 11 to be welded, completing the welding. In the above-mentioned flash welding process, the reciprocating friction of the first welding surface and the second welding surface by the friction extruder 7 extrudes the liquid metal, impurities and oxides generated on the first welding surface and the second welding surface during flash welding, thereby improving the mechanical properties and welding quality of the welded joint.

[0037] In one embodiment of the present invention, in step four, the moving frame electrode 6 is provided with multiple moving frame cooling air outlets 17, the stationary frame electrode 8 is provided with multiple stationary frame cooling air outlets 18, and the extrusion end electrode 5 is provided with multiple extrusion end cooling air outlets 19. The multiple moving frame cooling air outlets 17, multiple stationary frame cooling air outlets 18, and multiple extrusion end cooling air outlets 19 are all used to connect to an air compressor. When flash welding is performed, the controller controls the air compressor to start to cool the first welding end 12 and the second welding end 13. The cooling air blown out from the stationary frame cooling air outlets 18, moving frame cooling air outlets 17, and extrusion end cooling air outlets 19 can reduce the temperature during the flash welding process, thereby reducing the temperature of the heat-affected zone, reducing the size of the heat-affected zone of the weld joint, avoiding carbide precipitation and cracking at the weld joint, and thus improving the quality of the weld joint.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A friction-assisted flash welding device for steel rails, characterized in that, Includes a stationary frame, a moving frame, a fixture, a drive unit, an extrusion end electrode, a moving frame electrode, a friction extruder, a stationary frame electrode, an upsetting device, and a controller, wherein: The stationary frame is used to clamp or release the first rail to be welded, the first rail to be welded including a first welding surface; The movable frame is used to clamp or release the second rail to be welded, the second rail to be welded including a second welding surface; The friction extruder is detachably mounted on the fixture. The friction extruder includes a first contact surface and a second contact surface facing away from each other. The first contact surface is used to contact the first welding surface, and the second contact surface is used to contact the second welding surface. The driving device drives the fixture and the friction extruder to reciprocate together along the length direction perpendicular to the first rail to be welded. The first rail to be welded includes a first welding end, and the moving electrode is fitted and installed on the first welding end; the second rail to be welded includes a second welding end, the second welding end and the first welding end are arranged opposite to each other, the stationary electrode is fitted and installed on the second welding end, and both the moving electrode and the stationary electrode are used to connect to the positive terminal of the welding power source; The extrusion end electrode is attached to the friction extruder and is used to connect to the negative terminal of the welding power source. The upsetting device is used to drive the moving frame to reciprocate in a direction that approaches or moves away from the stationary frame; The controller controls the operation of the drive device, the upsetting device, the stationary frame, and the moving frame, and the controller controls the on / off state of the welding power supply.

2. The friction-assisted flash welding equipment for rails according to claim 1, characterized in that, The fixture is provided with a snap-fit ​​groove, and the friction extruder is snap-fitted into the snap-fit ​​groove.

3. The friction-assisted rail flash welding equipment according to claim 1, characterized in that, The moving electrode is fitted and installed at the rail web of the first welding end, and the stationary electrode is fitted and installed at the rail web of the second welding end.

4. The friction-assisted flash welding equipment for rails according to claim 1, characterized in that, The driving device includes a first cylinder and a first piston rod drivenly connected to the first cylinder. The first piston rod is detachably mounted on the clamp. The first piston rod drives the clamp and the friction extruder to reciprocate together along the length direction perpendicular to the first rail to be welded.

5. The friction-assisted flash welding equipment for rails according to claim 1, characterized in that, The extrusion end electrode includes a conductive busbar, one end of which is mounted on the extrusion end electrode, and the other end of which is connected to the welding power source.

6. The friction-assisted flash welding equipment for rails according to claim 1, characterized in that, The upsetting device includes a second cylinder and a second piston rod drivenly connected to the second cylinder. The second cylinder is fixedly mounted on the stationary frame, and the second piston rod is mounted on the moving frame. The second piston rod drives the moving frame to reciprocate in a direction close to or away from the stationary frame.

7. The friction-assisted flash welding equipment for rails according to claim 1, characterized in that, The moving frame electrode is provided with multiple moving frame cooling air outlets, the stationary frame electrode is provided with multiple stationary frame cooling air outlets, and the extrusion end electrode is provided with multiple extrusion end cooling air outlets. The multiple moving frame cooling air outlets, the multiple stationary frame cooling air outlets, and the multiple extrusion end cooling air outlets are all used to connect to the air compressor, and the controller controls the start and stop of the air compressor.

8. The friction-assisted flash welding equipment for rails according to claim 1, characterized in that, The friction extrusion part is made of U71Mn or a nickel-based high-temperature alloy.

9. A friction-assisted flash welding method for steel rails, characterized in that, Flash welding using the friction-assisted rail flash welding equipment according to any one of claims 1 to 8 includes the following steps: Step 1: Use a rust removal machine to remove the loose rust, oil, and scale from the first and second welding surfaces; Step 2: The controller controls the moving frame to clamp the first rail to be welded, the first rail to be welded including a first welding surface. The controller controls the stationary frame to clamp the second rail to be welded, the second rail to be welded including a second welding surface. The friction extruder is detachably mounted on the fixture. The friction extruder includes a first contact surface and a second contact surface facing away from each other. The first contact surface is used to contact the first welding surface, and the second contact surface is used to contact the second welding surface. Step 3: The first rail to be welded includes a first welding end, and the moving frame electrode is attached to and installed on the first welding end; the second rail to be welded includes a second welding end, the second welding end and the first welding end are arranged opposite to each other, and the stationary frame electrode is attached to and installed on the second welding end, and both the moving frame electrode and the stationary frame electrode are used to connect to the positive terminal of the welding power source; the extrusion end electrode is attached to and installed on the friction extruder, and the extrusion end electrode is used to connect to the negative terminal of the welding power source; Step 4: The controller controls the welding power supply to turn on, and flash welding is performed between the first welding surface and the first mating surface, and between the second welding surface and the second mating surface, until a thin liquid film is formed on both the first welding surface and the second welding surface. The controller then controls the welding power supply to turn off, stopping the flash welding. Step 5: The controller controls the drive device to start, so that the drive device drives the clamp and the friction extruder to reciprocate together along the length direction perpendicular to the first rail to be welded; Step Six: After the liquid metal, inclusions and oxides at the first welding surface and the second welding surface are completely extruded, the controller controls the drive device to move, so that the clamp and the friction extruder move away from the first welding surface and the second welding surface together. The controller controls the upsetting device to move, so that the moving frame moves towards the stationary frame, quickly increasing the upsetting pressure, and realizing the metallurgical bond between the first welding surface and the second welding surface. Step 7: After the upsetting time requirement is met, the moving frame releases the first rail to be welded, and the stationary frame releases the second rail to be welded, thus completing the welding.

10. The friction-assisted flash welding method for rails according to claim 9, characterized in that, In step four, the moving frame electrode is provided with multiple moving frame cooling air outlets, the stationary frame electrode is provided with multiple stationary frame cooling air outlets, and the extrusion end electrode is provided with multiple extrusion end cooling air outlets. All of the multiple moving frame cooling air outlets, multiple stationary frame cooling air outlets, and multiple extrusion end cooling air outlets are connected to an air compressor. When flash welding is performed, the controller controls the air compressor to start, so as to cool the first welding end and the second welding end.

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