Rail induction friction composite welding device and welding method

Abstract

The application discloses a steel rail induction friction composite welding device and a welding method. The far ends of two steel rails to be welded are clamped and fixed through a fixed-end clamping mechanism and a movable-end clamping mechanism. The two steel rails to be welded are adapted and centered under the action of a vibration clamping mechanism and a friction vibrator. The two welding surfaces are heated through an induction heating coil. After the two welding surfaces are heated to a target temperature, the friction vibrator is started, and after the amplitude and frequency are stabilized, the two welding surfaces are tightly hit by a top forging mechanism to vibrate and rub, so that the grains in the friction area are refined and more eutectic structures are formed. When the grain refinement degree and the eutectic quantity both reach predetermined requirements, the friction vibration is stopped, and a top forging force is applied through the top forging mechanism to complete solid-phase welding. The application realizes solid-phase welding through induction heating and friction welding, reduces or even eliminates high-temperature metal splashing, thereby improving the rail welding construction environment, reducing environmental pollution and being beneficial to environmental protection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of railway rail friction welding, in particular to a rail induction friction composite welding device and a welding method. BACKGROUND

[0002] With the large promotion and application of China's high-speed rail technology at home and abroad, as well as the construction of high-speed rail network under various extreme weather conditions, higher requirements are put forward for seamless line rails that bear the operation of high-speed trains. The most critical and important part of realizing seamless line is rail welding, and the welding method used plays a decisive role in the safety and reliability, energy saving and environmental protection (environmental pollution), quality and efficiency of rail welding.

[0003] In view of the high-strength rail material and the requirements for its welding quality, the rail welding team of Southwest Jiaotong University puts forward the first level solution: adopting rail friction welding. Rail friction welding is a special friction welding method adopted for the material and structural characteristics of the rail and the actual situation of engineering application. Referring to Chinese invention patents CN108568591A and CN108788443A, these two patent documents respectively provide a rail friction welding method and a rail linear friction welding method, which uses friction heat, which is internal heat, has less heat loss, high heat efficiency, fast heating speed, short welding time, and no welding defects related to melting and solidification in the welding zone. The grain is ultra-fine and the structure is dense in the welding zone under the combined mechanical action of heat, pressure and torque, and the joint not only has high connection quality, but also can reach or exceed the performance of the base material.

[0004] In view of the actual application situation of rail welding engineering construction, the second level solution is proposed and popularized, referring to Chinese invention patents CN110052697A and CN110899955B, which respectively provide a third body rail friction welding method and a friction welding system and method for elongated pieces, which well solves the problems of in-situ rail friction welding and on-site friction welding construction of ultra-long rails.

[0005] Although the above-mentioned patent documents provide a solution that can weld rails that meet the quality requirements, the rail friction welding solution is difficult to enter engineering application and popularization due to the excessive cost of rail friction welding equipment (about 500,000 yuan).

[0006] To solve the above problems, referring to Chinese invention patent CN113210820B, which is proposed as a third level solution, it discloses a flash welding method, which is a rail flash friction composite welding method in the field of rail welding. It is found in application practice that the application of the rail flash friction composite welding method can greatly reduce the manufacturing cost of the rail friction welding equipment by more than 80%.

[0007] Although the above-mentioned steel rail flash friction composite welding method can reduce the manufacturing cost of equipment, a large amount of flash splashes will be generated during the flash heating process, forming fine metal dust diffused in the air, which will cause harm to the equipment itself and the operating personnel. Especially, the flash heating in the closed space such as super-long tunnel and subway will cause more serious environmental pollution. Therefore, the current steel rail flash friction composite welding method still has defects, and it is necessary to provide a new technical scheme to solve the above-mentioned problems. SUMMARY

[0008] The present application provides a steel rail induction friction composite welding device and welding method to solve the problem of poor working conditions and environmental pollution caused by flash splashes in the current steel rail welding process.

[0009] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0010] On the one hand, the present application provides a steel rail induction friction composite welding device, which comprises a motion controller and a fixed end clamping mechanism, a moving end clamping mechanism, a vibration clamping mechanism, a friction vibrator, an induction heating coil, a top forging mechanism and a push bump mechanism connected with the motion controller respectively;

[0011] The fixed end clamping mechanism and the moving end clamping mechanism are oppositely and spaced apart, the fixed end clamping mechanism is used to clamp one end of the first steel rail to be welded, the moving end clamping mechanism is used to clamp one end of the second steel rail to be welded, the first steel rail to be welded and the second steel rail to be welded are oppositely arranged and leave a heating gap for accommodating the induction heating coil, the vibration clamping mechanism is used to clamp one end of the first steel rail to be welded close to the welding surface and one end of the second steel rail to be welded close to the welding surface, the vibration clamping mechanism is driven by the friction vibrator to realize the adaptation of the two rails in the center; the induction heating coil is arranged in the heating gap to heat the welding surfaces located on both sides thereof; the top forging mechanism is arranged on one side of the moving end clamping mechanism and is used to tightly clamp the second steel rail to be welded and the first steel rail to be welded; the push bump mechanism is used to remove the welding bump on the steel rail.

[0012] In the above-mentioned technical scheme, the fixed end clamping mechanism and the moving end clamping mechanism are oppositely and spaced apart on the rack, the fixed end clamping mechanism comprises two oppositely arranged clamping arms and a driving assembly for driving the two clamping arms to approach or move away from each other, the two clamping arms are driven to approach each other and abut against the side wall of the first steel rail to be welded, thereby clamping the first steel rail to be welded.

[0013] Further, the mobile end clamping mechanism is installed on the rack through a guide rail, the mobile end clamping mechanism moves along the rack through the guide rail, the mobile end clamping mechanism comprises two oppositely arranged clamping arms and a driving assembly for driving the two clamping arms to move close to or away from each other, the two clamping arms are driven to move close to each other and abut against the side wall of the second steel rail to be welded, so that the second steel rail to be welded is clamped.

[0014] Further, the induction heating coil is connected with an induction heater, the induction heater is arranged on the rack, and the induction heater is used to provide an induction heating current for the induction heating coil; the induction heating coil is connected with the motion controller through an actuator, and when both the two welding end faces exceed the recrystallization temperature, the motion controller moves the induction heating coil out of the heating gap through the actuator.

[0015] Further, the vibration clamping mechanism is located between the fixed end clamping mechanism and the mobile end clamping mechanism, the vibration clamping mechanism comprises two oppositely arranged vibration clamping seats, one vibration clamping seat clamps one steel rail to be welded, and a rotating shaft is arranged on each of the two vibration clamping seats, and the vibration clamping seat is connected with the friction vibrator through the rotating shaft.

[0016] Further, the friction vibrator is installed on the rack through an elastic connector, two connecting shafts for connecting the rotating shafts are arranged on the friction vibrator, the central axis of the rotating shaft is perpendicular to the plane where the steel rail to be welded is located, and the central axis of the connecting shaft is parallel to the plane where the steel rail to be welded is located; under the action of the motion controller, the friction vibrator drives the vibration clamping mechanism to vibrate, so that the two steel rails to be welded are centered and reciprocatingly frictionally vibrate along the plane parallel to the welding surface.

[0017] Further, the nub pushing mechanism is installed on the mobile end clamping mechanism, the nub pushing mechanism is located around the steel rail to be welded, the nub pushing mechanism comprises a nub pushing cylinder, a nub pushing end is arranged on a nub pushing rod of the nub pushing cylinder, and the nub pushing rod moves along the length direction of the steel rail to be welded under the action of the motion controller.

[0018] Further, the nub pushing mechanism is arranged on one side of the mobile end clamping mechanism and close to the welding surface of the steel rail to be welded.

[0019] Further, the nub pushing mechanism is installed on the mobile end clamping mechanism, the nub pushing mechanism is located around the steel rail to be welded, the nub pushing mechanism comprises a nub pushing cylinder, a nub pushing end is arranged on a nub pushing rod of the nub pushing cylinder, and the nub pushing rod moves along the length direction of the steel rail to be welded under the action of the motion controller.

[0020] In another aspect, based on the above provided rail induction friction composite welding device, the application further provides a rail induction friction composite welding method, which comprises the following steps:

[0021] S1: far-end clamping: clamping one end of the first rail to be welded by the fixed-end clamping mechanism, and clamping one end of the second rail to be welded by the moving-end clamping mechanism, so that the first rail to be welded and the second rail to be welded are oppositely arranged and a heating gap for accommodating the induction heating coil is reserved;

[0022] S2: near-end centering: clamping and fixing one end of the first rail to be welded close to the welding surface and one end of the second rail to be welded close to the welding surface by the vibration clamping mechanism, and adjusting the two rails to be welded by the friction vibrator so that the two welding surfaces are adapted and centered;

[0023] S3: induction heating: moving the induction heating coil into the heating gap between the two welding surfaces and simultaneously heating the two welding surfaces, and when the temperature of the two welding surfaces exceeds the recrystallization temperature, moving the induction coil out of the heating gap and starting the vibration of the friction vibrator and the feeding of the upsetting mechanism;

[0024] S4: vibration friction: when the vibration frequency and amplitude of the friction vibrator are stable, the two welding surfaces are tightly pressed by the upsetting mechanism to form a friction interface;

[0025] S5: upsetting welding: when the grain refinement degree and eutectic quantity of the friction interface meet the predetermined requirements, stopping the friction vibration, and again applying the upsetting force to the welding joint by the upsetting mechanism to form sufficient common fine-grained structure in the welding joint area to complete the solid-phase welding of the rail;

[0026] S6: push-bump cooling: under the pressing action of the upsetting mechanism, the vibration clamping mechanism releases the rail, the push-bump mechanism is started to remove the welding bumps on the surface of the rail, and the welding joint area is cooled.

[0027] Compared with the prior art, the application has the following beneficial effects:

[0028] 1. The steel rail induction friction composite welding device provided by the application clamps and fixes the distal ends of two steel rails to be welded through the fixed end clamping mechanism and the moving end clamping mechanism, and the two steel rails to be welded are adapted and centered under the action of the vibration clamping mechanism and the friction vibrator, an induction heating coil is arranged between the two steel rails to be welded, induction heating is performed through the induction heating coil, the problem of high-temperature metal spatter during flash welding is completely eliminated, friction welding is performed after the two steel rails to be welded are heated to the target temperature, the friction vibrator is started to vibrate, and after the amplitude and frequency are stabilized, the two steel rails to be welded are tightly pressed by the top forging mechanism to vibrate and rub, under the joint action of the vibration force and the pressing force, impurities and foreign matters in the friction zone are removed, the crystal grains in the friction zone are refined, and more eutectic structures are formed in the friction zone, when the degree of grain refinement and the number of eutectic structures reach the predetermined requirements, the friction vibration is stopped, and enough top forging force is applied again through the top forging mechanism to form enough common fine-grained structures in the bonding area, so that solid-phase welding of the steel rails is realized. Therefore, the steel rail induction friction composite welding device provided by the application realizes solid-phase welding through induction heating and friction welding, reduces or even eliminates high-temperature metal spatter, thereby improving the welding rail construction environment, reducing environmental pollution, being conducive to environmental protection, and being particularly suitable for steel rail welding construction in super-long tunnels, subways and other enclosed spaces.

[0029] 2. The steel rail induction friction composite welding device provided by the application can improve the welding rail construction environment, avoid high-temperature metal spatter, greatly reduce the difficulty and frequency of maintenance of the welding rail equipment, thereby reducing labor intensity and use cost, and being easy to maintain.

[0030] 3. The steel rail induction friction composite welding device provided by the application uses an induction heating coil (120KW) to heat the end face to be welded, and the required power and energy consumption are less than half of the power and energy consumption of the flash heating (300KW) method, which can reduce the production cost and use cost of the equipment, thereby reducing energy consumption and being low-carbon and environmentally friendly.

[0031] 4. The steel rail induction friction composite welding device provided by the application uses an induction heating method, and the steel rail to be welded does not need to be conductive, so there is no need to consider problems related to conduction during the design and manufacture of the mechanism, such as the insulation problem of the fixed end clamping mechanism and the moving end clamping mechanism, the material and area of the conductive mechanism, and the electrode heating and cooling problem, which can greatly reduce the difficulty of designing and manufacturing the device and reduce the manufacturing cost. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative effort. It should be understood that the specific shapes and structures shown in the drawings should not be regarded as limiting conditions for implementing the present application; for example, based on the technical concepts and exemplary drawings disclosed in the present application, those skilled in the art can easily make routine adjustments or further optimization to some units (components) in terms of increase / decrease / assignment, specific shape, positional relationship, connection mode, size ratio relationship, etc.

[0033] Figure 1 A structural schematic diagram of a rail induction friction composite welding device provided in an embodiment of the present application.

[0034] Legend of reference signs:

[0035] 1, frame; 2, motion controller; 3, fixed end clamping mechanism; 4, moving end clamping mechanism; 5, vibration clamping mechanism; 6, elastic connector; 7, friction vibrator; 71, connecting shaft; 8, induction heating coil; 9, induction heater; 10, top forging cylinder; 11, tumor pushing cylinder; 12, first rail to be welded; 13, second rail to be welded. DETAILED DESCRIPTION

[0036] The present application will be further described in detail below with reference to the drawings.

[0037] In the description of the present application: unless otherwise specified, the meaning of "a plurality of" is two or more. The terms "first", "second", "third", etc. in the present application are intended to distinguish the objects referred to, and do not have special meanings in terms of technology (for example, should not be understood as emphasizing importance or order, etc.). The expressions "include", "contain", "have", etc. also mean "not limited to" (some units, components, materials, steps, etc.).

[0038] The terms such as "upper", "lower", "left", "right", "middle", etc. cited in the present application are generally used for intuitive understanding with reference to the drawings, and are not absolute limitations on the positional relationship in the actual product. Changes in these relative positional relationships are also regarded as the scope of the present application without departing from the technical concept disclosed in the present application.

[0039] In the flash heating process of flash friction composite welding of the steel rail, a large amount of flash spatter is generated, fine metal dust is diffused in the air, and the equipment itself and the operating personnel are harmed, especially the flash heating in the closed space such as the super-long tunnel and the subway is more serious in the environmental pollution. Therefore, how to reduce or eliminate the environmental pollution of the flash spatter in the process of the steel rail flash friction composite welding has become a problem to be solved.

[0040] Therefore, the application provides a steel rail induction friction composite welding device and a welding method, mainly combining the steel rail induction heating method and the steel rail friction welding to form an induction heating friction composite welding, which can realize the friction welding of the solid steel rail, is beneficial to reduce or even eliminate the environmental pollution, can improve the steel rail welding efficiency and quality, can reduce or even eliminate the flash spatter in the process of the steel rail flash friction composite welding, and can reduce the environmental pollution.

[0041] Embodiment one

[0042] The embodiment provides a steel rail induction friction composite welding device, the device uses an induction heating coil to simultaneously heat two end faces of a steel rail to be welded, moves out the induction heating coil when the two end faces reach above the recrystallization temperature range, simultaneously starts a friction vibrator to make the two heated end faces to start relative vibration, under the conditions that the frequency and the amplitude of the vibrator are stable, applies a suitable clamping force through a top forging mechanism, and under the joint action of the vibration force and the clamping force, can remove impurities and foreign matters from the end faces to be welded, can refine the grains in the bonding area, and can promote more eutectic structures to be formed; when the grain refinement degree and the eutectic quantity reach predetermined requirements, stops the friction vibration, and applies a higher top forging force through the top forging mechanism to form sufficient common fine-grained structures. Therefore, the steel rail induction friction composite welding device provided by the application can be used to realize a solid-phase welding method of the steel rail.

[0043] The structure of the steel rail induction friction composite welding device provided by the application mainly includes a rack 1, a fixed end clamping mechanism 3, an induction heater 9, an induction heating coil 8, a friction vibrator 7, a vibration clamping mechanism 5, a motion controller 2, a bulge removing mechanism, a moving end clamping mechanism 4 and a top forging mechanism, such as Figure 1 .

[0044] The rack 1 is a mounting support framework of each component of the steel rail induction friction composite welding device provided by the application, and each component is mounted and integrated on the rack 1.

[0045] The fixed end clamping mechanism 3 is rigidly fixed and mounted on the rack 1, and the rigid fixed connection mode is not limited as long as the fixed mounting can be realized. The fixed end clamping mechanism 3 applies a clamping force to the target steel rail to be welded, prevents the slipping phenomenon between the steel rail and the clamp during clamping or top forging, such as Figure 1The fixed end clamping mechanism 3 clamps and fixes the first steel rail to be welded 12. In this embodiment, the fixed end clamping mechanism 3 has a clamping seat for clamping the target steel rail to be welded, which includes two oppositely arranged clamping arms. The two clamping arms are controlled to approach each other to clamp the steel rail, and are controlled to move away from each other to release the steel rail. Of course, the fixed end clamping mechanism 3 can also have other structures, such as a jaw, as long as it can clamp and fix the steel rail, and the present application does not make special limitations.

[0046] The induction heater 9 is also fixed on the rack 1. The induction heater 9 is connected with the induction heating coil 8 to provide an induction heating current for the induction heating coil 8. The size of the induction heating current of the induction heating coil 8 can be controlled through the induction heater 9.

[0047] The induction heating coil 8 is connected with the induction heater 9. In actual production and application, the induction heating coil 8 is customized according to the shape and size of the cross-sectional area of the steel rail, and can simultaneously heat the two end faces of the steel rail to be welded to make the surface temperature above the recrystallization temperature.

[0048] As shown in Figure 1 , the friction vibrator 7 is installed on the rack 1 through the elastic connector 6. The friction vibrator 7 can generate high-frequency low-amplitude mechanical vibration, and the vibration clamping mechanism 5 acts on the two high-temperature end faces of the steel rail to be welded to generate friction vibration between them. The elastic connector 6 can play a role in buffering and shock absorption when transmitting force, and can reduce the influence caused by vibration, impact or unbalanced force. Due to its elastic properties, the elastic connector 6 can adjust and compensate when the connected parts are displaced or angularly changed.

[0049] The vibration clamping mechanism 5 is connected with the friction vibrator 7 through a rotating shaft. The vibration clamping mechanism 5 can clamp and align the two steel rails to be welded. The vibration clamping mechanism 5 includes two oppositely arranged vibration clamping seats, as shown in Figure 1 , one vibration clamping seat clamps and fixes one steel rail to be welded. The two vibration clamping seats are provided with rotating shafts, and the friction vibrator 7 is provided with two connecting shafts 71 for connecting the two rotating shafts. The central axis of the rotating shaft is perpendicular to the plane where the steel rail is located, the central axis of the connecting shaft 71 is parallel to the plane where the steel rail is located, and the central axis of the rotating shaft is perpendicular to the central axis of the connecting shaft 71. Therefore, the friction vibrator 7 makes the two steel rails to be welded centered and reciprocatingly vibrates along the plane parallel to the steel rail welding face through the vibration clamping mechanism 5.

[0050] The motion controller 2 in the present application is mainly used to control the motion of the friction vibrator 7, the top forging mechanism, the nub pushing mechanism, the induction heating coil 8, the moving end clamping mechanism 4, and coordinate the actions of various mechanisms in the steel rail induction friction composite welding device.

[0051] The mobile end clamping mechanism 4 is installed on the frame 1 through a guide rail and is freely slidable relative to the frame 1, like Figure 1 The mobile end clamping mechanism 4 clamps and fixes the second steel rail to be welded 13, thus having the ability to prevent the steel rail from slipping during the upsetting, and also being a mounting seat of the bump pushing mechanism.

[0052] The bump pushing mechanism is installed on the mobile end clamping mechanism 4 and is distributed around the steel rail to push away the welding bump after the upsetting is completed. The bump pushing mechanism comprises a bump pushing cylinder 11, and a bump pushing end head is arranged on a bump pushing rod of the bump pushing cylinder 11. The bump pushing rod moves along the length direction of the steel rail to be welded under the action of the motion controller 2 and scrapes off the welding bump through the bump pushing end head during the movement.

[0053] The upsetting mechanism comprises an upsetting cylinder 10, which is installed on the frame 1. An upsetting rod installed on the upsetting cylinder 10 is fixed on the mobile end clamping mechanism 4. The central axis of the upsetting rod is parallel to the length direction of the steel rail to be welded. The upsetting mechanism can stably and quickly provide the upsetting force or the upsetting force for the friction composite welding.

[0054] The steel rail induction friction composite welding device provided by the application uses an induction coil to replace a flash to heat the end face to be welded, completely eliminates the high-temperature metal splashing during the flash, improves the welding rail construction environment, reduces environmental pollution, is conducive to environmental protection, is particularly suitable for steel rail welding construction in a closed space such as an ultra-long tunnel and a subway, and provides a solution for welding rail construction of an ultra-long tunnel.

[0055] The steel rail induction friction composite welding device provided by the application uses an induction heating (120KW) mode to heat the end face to be welded, and the required power and energy consumption are less than half of those of a flash heating (300KW) mode, so that the production cost and use cost of the equipment can be reduced, energy consumption is reduced, and low-carbon environmental protection is achieved.

[0056] The use of the steel rail induction friction composite welding device provided by the application can improve the welding rail construction environment, avoid high-temperature metal splashing, greatly reduce the difficulty and frequency of maintenance of the welding rail equipment, and thus reduce the labor intensity and use cost, and is easy to maintain.

[0057] In the steel rail induction friction composite welding device provided by the application, the steel rail to be welded using the induction heating mode does not need to be conductive, and problems related to conduction do not need to be considered during the design and manufacture of the mechanism, such as the insulation problem of the fixed end and the mobile end, the material and area of the conduction mechanism, and the electrode heating and cooling problem. The difficulty of design and manufacture of the device can be greatly reduced, and the manufacturing cost can be reduced.

[0058] Embodiment two

[0059] Based on the rail induction friction composite welding device provided in Embodiment 1, this embodiment provides a rail preheating friction composite welding method.

[0060] The rail preheating friction composite welding method provided in this embodiment includes the following steps, such as... Figure 1 :

[0061] 1. (Rail) Far-end clamping: Place the two rails to be welded into the fixed end clamping mechanism 3 and the moving end clamping mechanism 4 respectively, and clamp the rails at a position away from the surface to be welded. Leave a heating gap between the two surfaces to be welded for the induction heating coil 8.

[0062] 2. (Rail) Near-end alignment: The vibration clamping mechanism 5 clamps the two rails to be welded from above and below at positions close to the end faces to be welded, ensuring that the two end faces to be welded are aligned front to back (i.e., working edges, along the length of the rails). Figure 1 Alignment is achieved in the left-right direction (as shown on the paper), and the two surfaces to be welded are aligned vertically (by adjusting the friction vibrator 7). Figure 1 Alignment (as shown on the paper in the vertical direction) is the ultimate goal of aligning the center axes of the two rails to achieve seamless welding.

[0063] 3. (Rail end face to be welded) Induction heating: Move the induction heating coil 8 into the gap between the two end faces to be welded, and heat the two end faces to be welded at the same time after powering on. When both end faces to be welded exceed the recrystallization temperature, quickly move the induction heating coil 8 out of the welding area, turn on the friction vibrator 7 to start vibration and the upsetting mechanism to feed in.

[0064] 4. Vibration and friction: When the frequency and amplitude of the vibration output of the friction vibrator 7 are stable, the two end faces to be welded are quickly pressed together by the upsetting mechanism to form a friction interface. Under the combined action of vibration force and upsetting force, impurities and foreign objects in the friction zone can be removed, the grains in the friction zone can be refined, and more eutectic structures can be formed in the friction zone.

[0065] 5. Upsetting and welding: When the grain refinement and eutectic quantity both meet the predetermined requirements, stop the friction vibration, and apply a sufficiently high upsetting force again through the upsetting mechanism to form a sufficient common fine grain structure in the bonding area to achieve solid-phase welding of the rail.

[0066] 6. Cooling the weld bead: Under the action of maintaining the upsetting force, on the one hand, the vibration clamping mechanism 5 must be released and the weld bead removal mechanism must be pushed forward to complete the removal of the weld bead; on the other hand, the cooling rate of the metal in the joint area must be controlled so as to ensure that the phase transformation process of the metal in the joint area is completed quickly and to obtain a solid welded joint with excellent comprehensive performance.

[0067] The application provides a steel rail induction friction composite welding method, which realizes induction heating through an induction heating coil, realizes vibration friction welding through friction welding, and realizes solid-phase welding by combination of the two, so that the problem of high-temperature metal splashing can be reduced or even eliminated, thereby improving the rail welding construction environment, reducing environmental pollution, being conducive to environmental protection, and being particularly suitable for steel rail welding construction in closed spaces such as super-long tunnels and subways.

[0068] The technical features of the above embodiments can be combined in any manner (as long as the combination of the technical features does not contradict), and to make the description concise, all possible combinations of the technical features in the above embodiments are not described; the embodiments not explicitly written should also be considered as falling within the scope of the present application.

[0069] The application is described in detail above through general description and specific embodiments. It should be understood that, based on the technical concept of the application, some conventional adjustments or further innovations can be made to the specific embodiments; however, as long as the technical concept of the application is not deviated, the technical solutions obtained by the conventional adjustments or further innovations also fall within the protection scope of the claims of the present application.

Claims

1. A rail induction friction composite welding apparatus, characterised in that, The device comprises a motion controller (2), a fixed end clamping mechanism (3), a moving end clamping mechanism (4), a vibration clamping mechanism (5), a friction vibrator (7), an induction heating coil (8), a top forging mechanism and a bump pushing mechanism, which are connected with the motion controller (2) respectively. The fixed end clamping mechanism (3) is arranged opposite to the moving end clamping mechanism (4) and is used to clamp one end of a first steel rail (12) to be welded, the moving end clamping mechanism (4) is used to clamp one end of a second steel rail (13) to be welded, the first steel rail (12) and the second steel rail (13) are arranged opposite to each other and leave a heating gap for accommodating the induction heating coil (8), the vibration clamping mechanism (5) is used to clamp one end of the first steel rail (12) close to a welding surface and one end of the second steel rail (13) close to a welding surface, the vibration clamping mechanism (5) is driven by the friction vibrator (7) to realize the adaptation of the two steel rails in the opposite direction, the induction heating coil (8) is arranged in the heating gap and is used to heat the welding surfaces on both sides of the induction heating coil (8), the top forging mechanism is arranged on one side of the moving end clamping mechanism (4) and is used to tightly press the second steel rail (13) to the first steel rail (12), and the bump pushing mechanism is used to remove the welding bumps on the steel rails. The friction vibrator (7) is installed on the rack (1) through an elastic connector (6), the friction vibrator (7) can generate high-frequency and low-amplitude mechanical vibration, and the vibration clamping mechanism (5) is used to act on the two high-temperature end surfaces of the steel rails to be welded to generate friction vibration between them, wherein the elastic connector (6) plays a role of buffering and damping when transmitting force, reduces the influence caused by vibration, impact or unbalanced force, and can adjust and compensate when the connecting parts are displaced or angularly changed. The fixed end clamping mechanism (3) is arranged opposite to the moving end clamping mechanism (4) on the rack (1), the fixed end clamping mechanism (3) comprises two oppositely arranged clamping arms and a driving assembly for driving the two clamping arms to move close to or away from each other, and the two clamping arms are driven to move close to each other and abut against the side wall of the first steel rail (12) to be welded to clamp the first steel rail (12). The moving end clamping mechanism (4) is installed on the rack (1) through a guide rail, the moving end clamping mechanism (4) moves along the rack (1) through the guide rail, the moving end clamping mechanism (4) comprises two oppositely arranged clamping arms and a driving assembly for driving the two clamping arms to move close to or away from each other, and the two clamping arms are driven to move close to each other and abut against the side wall of the second steel rail (13) to be welded to clamp the second steel rail (13).

2. The apparatus for induction friction stitch welding of a rail as defined in claim 1, wherein, The induction heating coil (8) is connected with an induction heater (9), the induction heater (9) is arranged on the rack (1), and the induction heater (9) is used to provide an induction heating current for the induction heating coil (8); the induction heating coil (8) is connected with the motion controller (2) through an actuator, and when both of the two to-be-welded end faces exceed the recrystallization temperature, the motion controller (2) moves the induction heating coil (8) out of the heating gap through the actuator.

3. The rail induction friction stitch welding apparatus of claim 1 wherein, The vibration clamping mechanism (5) is located between the fixed end clamping mechanism (3) and the moving end clamping mechanism (4), the vibration clamping mechanism (5) comprises two vibration clamping seats arranged oppositely, one vibration clamping seat clamps one to-be-welded steel rail, and rotating shafts are arranged on the two vibration clamping seats, and the vibration clamping seats are connected with the friction vibrator (7) through the rotating shafts.

4. The apparatus for induction friction stitch welding of a rail as defined in claim 3, wherein, The friction vibrator (7) is installed on the rack (1) through an elastic connector (6), two connecting shafts (71) for connecting the rotating shafts are arranged on the friction vibrator (7), the central axis of the rotating shaft is perpendicular to the plane where the to-be-welded steel rail is located, and the central axis of the connecting shaft (71) is parallel to the plane where the to-be-welded steel rail is located; the friction vibrator (7) drives the vibration clamping mechanism (5) to vibrate under the action of the motion controller (2), so that the two to-be-welded steel rails are centered and reciprocally frictionally vibrate along the plane parallel to the to-be-welded surface.

5. The rail induction friction stitch welding apparatus of claim 1 wherein, The nub pushing mechanism is installed on the moving end clamping mechanism (4), the nub pushing mechanism is located around the to-be-welded steel rail, the nub pushing mechanism comprises a nub pushing cylinder (11), a nub pushing end is arranged on a nub pushing rod of the nub pushing cylinder (11), and the nub pushing rod moves along the length direction of the to-be-welded steel rail under the action of the motion controller (2). The nub pushing mechanism is arranged on one side of the moving end clamping mechanism (4) and close to the to-be-welded surface of the to-be-welded steel rail.

6. The rail induction friction stitch welding apparatus of claim 1 wherein, The top forging mechanism comprises a top forging cylinder (10), the top forging cylinder (10) is installed on the rack (1), a top forging rod installed on the top forging cylinder (10) is fixedly connected with the moving end clamping mechanism (4), and the central axis of the top forging rod is parallel to the length direction of the to-be-welded steel rail; the top forging rod extends outwards or retracts relative to the top forging cylinder (10) under the action of the motion controller (2).

7. A method of induction friction stitch welding of steel rails, characterised in that, The steel rail induction friction composite welding device comprises the following steps: S1: far end clamping: one end of the first to-be-welded steel rail (12) is clamped through the fixed end clamping mechanism (3), one end of the second to-be-welded steel rail (13) is clamped through the moving end clamping mechanism (4), and the first to-be-welded steel rail (12) and the second to-be-welded steel rail (13) are arranged oppositely and a heating gap for accommodating the induction heating coil (8) is reserved; S2: Near-end centering: The first steel rail (12) near the welding surface and the second steel rail (13) near the welding surface are respectively clamped and fixed by the vibration clamping mechanism (5), and the two steel rails are adjusted by the friction vibrator (7) to make the two welding surfaces fit and center; S3: Induction heating: The induction heating coil (8) is moved into the heating gap between the two welding surfaces, and the two welding surfaces are heated at the same time. When the temperature of the two welding surfaces exceeds the recrystallization temperature, the induction coil is moved out of the heating gap, and the friction vibrator (7) is started and the top forging mechanism is fed; S4: Vibration friction: When the vibration frequency and amplitude of the friction vibrator (7) are stable, the two welding surfaces are tightly pressed by the top forging mechanism to form a friction interface; S5: Top forging welding: When the grain refinement degree and eutectic quantity of the friction interface meet the predetermined requirements, stop the friction vibration, and apply the top forging force to the welding joint by the top forging mechanism again to form sufficient common fine-grained structure in the welding joint area to complete the solid-phase welding of the steel rail; S6: Pushing the tumor cooling: Under the pressing action of the top forging mechanism, the vibration clamping mechanism (5) releases the steel rail, and the tumor pushing mechanism is started to remove the welding tumor on the surface of the steel rail, and the welding joint area is cooled.

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