High-frequency induction brazing equipment and welding method thereof

Abstract

The invention relates to high-frequency induction brazing equipment and a welding method.The high-frequency induction brazing equipment comprises a wire welding machine, a cooperative heating device, an induction brazing device, a workpiece tool, a wire feeding device, a servo motor and a workbench, and the workpiece tool, the wire feeding device and the servo motor are all installed on the workbench; the wire feeding device comprises a wire feeding pipe, a wire feeding pipe fixing device and a wire feeding table, the wire feeding table is installed on the workbench, the wire feeding pipe fixing device is rotationally installed on the wire feeding table and connected with the servo motor, a welded workpiece is installed on the workpiece tool, the welded workpiece is composed of two matched sleeving structures, and the two sleeving structures are connected with the servo motor. The collaborative heating device is installed on the wire feeding device, the wire welding machine connects a welding wire into the wire feeding pipe and conveys the welding wire to the welding area or the position above the welding area or is connected with a welded workpiece, and the collaborative heating device is matched with the induction brazing device to jointly heat the welding wire section. The device is simple in structure and convenient to use, welding wires are melted efficiently, and digital and intelligent control is achieved.

Description

Technical Field

[0001] This application relates to a high-frequency induction brazing equipment and its welding method, which is mainly applicable to high-efficiency melting welding wire. Background Technology

[0002] In the air conditioning and refrigeration industry, brazing is commonly used for welding various pipe joints such as compressors and valves. Previously, when flame brazing was employed, the flame heated the pipe fittings while simultaneously heating the welding wire, resulting in a high temperature for the wire upon entering the molten pool. However, flame brazing is energy-intensive. In recent years, induction brazing has been increasingly adopted. Because the heating range of induction brazing is very small, the time it takes for the brazing material to be covered by the magnetic field in the induction coil is short. Therefore, during the workpiece heating process, the brazing material may not have reached the appropriate working state by the time it reaches the processing position, requiring a longer time before welding can begin. Summary of the Invention

[0003] The technical problem solved by this application is to overcome the above-mentioned deficiencies in the prior art and to provide a high-frequency induction brazing equipment and welding method that is simple in structure, easy to use, and efficient in melting welding wire.

[0004] The technical solution adopted by this application to solve the above-mentioned technical problems includes: a high-frequency induction brazing equipment, mainly comprising a wire welding machine, a co-heating device, an induction brazing device, a workpiece fixture, a wire feeding device, a servo motor, and a worktable. The workpiece fixture, the wire feeding device, and the servo motor are all mounted on the worktable. The wire feeding device includes a wire feeding tube, a wire feeding tube fixing device, and a wire feeding table. The wire feeding table is mounted on the worktable, and the wire feeding tube fixing device is rotatably mounted on the wire feeding table. The wire feeding tube fixing device is connected to the servo motor. The workpiece to be welded is mounted on the workpiece fixture. The workpiece to be welded consists of two mutually cooperating sleeve structures, forming a welding area between the two sleeve structures to accommodate molten solder. The co-heating device is mounted on the wire feeding device. The wire welding machine connects the required welding wire to the wire feeding tube and delivers it to the welding area or above the welding area, or electrically connects it to the workpiece to be welded. The co-heating device, in conjunction with the induction brazing device, heats the welding wire section (referring to the part before the tail end of the wire feeding tube), accelerating the melting speed of the welding wire tip and improving welding efficiency.

[0005] This application also includes a control device, which is connected to the wire welding machine, the co-heating device, the induction brazing device, and the servo motor, and controls them to work according to a set sequence, thereby improving the degree of automation.

[0006] This application also includes an infrared thermal imaging device, which is connected to a control device. The infrared thermal imaging device can accurately monitor the temperature of the workpiece during preheating and brazing, as well as the temperature signal of the exposed wire tip of the wire feed tube. This allows for timely activation of the wire welding machine and / or adjustment of the wire feeding speed and / or real-time adjustment of the power output of the co-heating device, thereby improving the welding speed and the welding quality of the brazing process, and achieving digital and intelligent control.

[0007] The workpiece to be welded consists of two interlocking tubular sleeve structures, with an annular molten pool between the two tubular sleeve structures to contain molten solder. The welding wire machine, wire feeding device, and welding wire are all in two sets. The ends of the two sets of welding wires are respectively sent to one side of the annular molten pool, melt simultaneously and enter the molten pool. After welding, a complete annular solder ring is formed, which welds and fixes the two tubular sleeve structures.

[0008] The synergistic heating device employs a preheating high-frequency induction coil wound around the outer surface of the wire feeding tube, which is a hollow ceramic tube.

[0009] The welding method for the preheating high-frequency induction coil (preheating high-frequency induction device) used in the collaborative heating device of this application is as follows: S0: Preparation steps, all devices and components are installed, the workpiece to be welded is installed on the workpiece fixture, the welding wire tip is connected to the wire feeding tube through the welding wire machine, the initial position of the welding wire tip and the wire feeding tube tip distance = set speed × (set temperature - initial temperature of welding wire tip)̸ set the heating rate of the welding wire tip under the preheating power of the co-heating device, and initialize the equipment; S1: The co-heating device and the induction brazing device are started, respectively heating the part of the welding wire located in the wire feeding tube and the workpiece to be welded. The welding wire machine starts the first stage of wire feeding, and the welding wire head is conveyed from the initial position to the head of the wire feeding tube. S2: The welding wire machine starts the second stage of wire feeding, conveying the welding wire tip to the welding area; S3: The tip of the welding wire enters the effective range of the induction brazing device and continues to be heated. The welding wire machine continues to feed the wire in the second stage, continuously sending the melting tip of the welding wire to the top of the molten pool to melt and fall into the molten pool or directly into the molten pool. S4: After the molten pool is filled or the specified brazing time is reached, the welding is completed. The induction brazing power supply is turned off, the induction brazing coil is turned on, the co-heating device is turned off, the wire welding machine pulls back the wire tip, and the brazed workpiece is removed.

[0010] This application also includes step S21 in step S2. S21: The infrared thermal imaging device detects the real-time temperature of the welding wire tip that has emerged from the wire feeding tube but has not yet entered the effective range of the induction brazing device and transmits it to the control device. The control device adjusts the power of the co-heating device according to the real-time temperature, so that the temperature of the welding wire that subsequently emerges from the wire feeding tube tip is closer to the design value.

[0011] The wire feeding tube consists of a metal wire feeding tube and a ceramic sleeve. The ceramic sleeve prevents the welding wire tip from being overheated and ensures good directionality after the welding wire tip emerges from the ceramic sleeve end (nozzle). The ceramic sleeve is a hollow conical shape, and the inner diameter of the ceramic sleeve end matches the diameter of the welding wire. The metal wire feeding tube is a hollow round iron tube.

[0012] The synergistic heating device uses a preheated heating wire wound around the outer surface of a metal wire feeding tube.

[0013] The welding method for the preheating heating wire used in the collaborative heating device of this application is as follows: S0: Preparation steps, all devices and components are installed, the welding wire is connected to the wire feeding tube through the welding wire machine, the initial position of the welding wire head is at the head of the wire feeding tube, and the equipment is initialized; S1: The co-heating device and induction brazing device are activated; S11: Start the induction brazing device and the co-heating device. The heating power of the co-heating device is the preheating power. S12: Preheating for the first period of time; S2: After the first preheating period, start the wire welding machine. The wire welding machine starts the first stage of wire feeding, and the wire tip is fed out from the wire feeding tube. S3: When the preheating set time is up, the heating power of the co-heating device is switched to normal power, and the first section of wire feeding continues; S4: After heating normally for a period of time, the wire welding machine starts the second stage of wire feeding; S5: The third stage of wire feeding: the wire tip melts and flows into the welding area under the action of the induction brazing device to complete the welding. After the welding area is filled or the specified brazing time is reached, the induction brazing power supply is turned off, the induction brazing coil is turned on, and the wire welding machine pulls the wire tip back.

[0014] Optionally, a layer of heat insulation / insulation material can be wrapped around the preheating heating wire to improve thermal efficiency and prevent waste.

[0015] The co-heating device uses a co-heating power supply. The negative terminal of the co-heating power supply is connected to the tail end of the wire feeding tube, and the positive terminal of the co-heating power supply is connected to the workpiece fixture made of conductive material. The workpieces to be welded are installed on the workpiece fixture and electrically connected to each other. The welding wire is electrically connected to the tail end of the wire feeding tube. The wire feeding tube is made of metal wire feeding tube and ceramic sleeve.

[0016] The end of the wire feeding tube is provided with an electrical connection ring made of conductive material. The electrical connection ring is electrically connected to the negative terminal of the co-heating power supply, and the inner wall of the electrical connection ring is electrically connected to the outer diameter of the welding wire.

[0017] The welding method for the synergistic heating device using a synergistic heating power supply in this application is as follows: S0: Preparation steps, all devices and components are installed, the welding wire is connected to the wire feeding tube through the welding wire machine, the initial position of the welding wire head is at the head of the wire feeding tube, and the equipment is initialized; S1: Start the induction brazing device. The workpiece to be welded is preheated with preheating power under the action of the induction brazing coil, and the welding wire in the wire feeding tube remains in its initial state. S2: The welding wire machine starts feeding welding wire in the first stage; S3: When the tip of the welding wire enters the effective range of the induction brazing device, the second stage of wire feeding begins until the tip of the welding wire reaches the surface of the workpiece to be welded, at which point the welding wire machine is turned off. S4: The positive and negative terminals of the co-heating power supply are connected, and the stage of co-heating and induction heating working together begins; S5: After a period of time, the stress in the section from the tip of the welding wire to the point where the welding wire contacts the negative electrode of the cooperating heating power supply gradually disappears and the temperature rises, and the tip of the welding wire softens. S6: The welding wire machine starts the third stage of wire feeding, and the tip of the welding wire melts and falls into or is immersed in the welding area; S6: The wire welding machine begins the fourth stage of wire feeding, and the tip of the wire is directly immersed in the molten pool formed by the molten wire. The wire welding machine, the co-heating device, and the induction brazing device are all turned off until this stage ends.

[0018] S7: Start the welding wire machine and pull back the welding wire tip.

[0019] This application improves the melting speed of the welding wire and reduces the welding waiting time by using a synergistic heating device and an induction brazing device, thereby achieving efficient brazing. Furthermore, it can monitor the temperature of the welding wire and the workpiece in real time through an infrared thermal imaging device, achieving closed-loop control of the temperature of the workpiece and the welding wire segment, preventing the workpiece from overheating, and realizing digital and automated control.

[0020] This application features a simple structure, ease of use, and efficient melting of welding wire, achieving digital and intelligent control. Attached Figure Description

[0021] Figure 1 This is a top view of an embodiment of the present application.

[0022] Figure 2 This is a schematic diagram of the principle of Embodiment 1 of this application.

[0023] Figure 3 yes Figure 2A magnified view of a portion of the image.

[0024] Figure 4 This is a top view schematic diagram showing the relative positions of the workpiece to be welded, the induction brazing coil, and the tip of the welding wire when they enter the effective range of the induction brazing device.

[0025] Figure 5 This is a schematic diagram of the principle of Embodiment 2 of this application.

[0026] Figure 6 This is a schematic diagram of the principle of Embodiment 3 of this application.

[0027] Among them, 1. Welding wire machine; 11. First welding wire machine; 12. Second welding wire machine; 2. Co-heating device; 21. First co-heating device; 211. First preheating high-frequency induction coil; 212. First preheating heating wire; 22. Second co-heating device; 221. Second preheating high-frequency induction coil; 222. Second preheating heating wire; 23. Co-heating power supply; 231. Positive terminal of co-heating power supply; 232. Negative terminal of co-heating power supply; 3. Induction brazing device; 31. Induction brazing power supply; 32. Induction brazing coil; 33. Operating range of induction brazing device (induction brazing coil); 4. 5. Workpiece tooling; 51. Wire feeding device; 511. Wire feeding tube; 512. Wire feeding tube head; 513. Wire feeding tube tail; 514. Electrical connection ring; 515. Metal wire feeding tube; 516. Metal wire feeding tube head; 517. Ceramic sleeve; 518. Wire feeding tube fixing device; 519. Wire feeding table; 6. Servo motor; 70. Welding wire; 71. Welding wire head; 81. Workpiece to be welded; 82. Outer workpiece to be welded; 83. Welding area formed between two workpieces to be welded to accommodate molten welding wire, which is a small area within the range of action of the induction brazing device, in special cases, the periphery of the molten pool or weld; 84. Inner workpiece to be welded. Detailed Implementation

[0028] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are explanations of the present application, but the present application is not limited to the following embodiments. Figure 1 The lower middle section is the front, and the upper section is the back.

[0029] like Figures 1-6As shown, this application includes a high-frequency induction brazing equipment. The high-frequency induction brazing equipment mainly includes two sets of wire welding machines, a co-heating device 2, a set of induction brazing devices 3, a set of workpiece fixtures 4, two sets of wire feeding devices 5, a set of servo motors 6, a control device, and a worktable (not shown in the figure). The workpiece fixtures 4, wire feeding devices 5, and servo motors 6 are all mounted on the worktable (not shown in the figure). The wire feeding device 5 includes a wire feeding tube 51, a wire feeding tube fixing device 52, and a wire feeding table 53. The wire feeding table 53 is mounted on the worktable. The wire feeding tube fixing device 52 is rotatably mounted on the wire feeding table 53. The wire feeding tube fixing device 52 is connected to the servo motor 6. The servo motor 6 controls the rotation of the wire feeding tube fixing device 52 to adjust the wire feeding angle and the position of the welding wire 7 head. The workpiece 8 to be welded is mounted on the workpiece fixture 4. The workpiece 8 to be welded is composed of two nested cylindrical structures. A welding area 812 for accommodating molten solder is formed between the two cylindrical structures. This application utilizes a coordinated heating device to preheat the tip 71 of the welding wire 7 to a suitable temperature (typically between 250 and 300°C in Examples 1 and 2) as it passes through the corresponding coordinated heating device 2. The welding wire 7 then continues to move towards the welding area. After the tip 71 of the welding wire extends out of the wire feed tube 51 and travels a certain distance (see...), the welding wire 7... Figure 3 As shown by the filler line, when the wire feed tube end 511 (which is a distance from the effective range 33 of the induction brazing device) enters the effective range of the induction brazing device 3 (located from the wire feed tube end 511 to the periphery of the welding area), the wire tip 71 is further heated and melted, falling into the welding area 812 for welding; or as shown in Embodiment 3, when the welding wire 7 touches the workpiece 8 to be welded, the section of the welding wire 7 from the wire tip 71 to the wire feed tube end 512 is directly heated by electricity, and the welding is accelerated by the thermal action of the induction brazing device 3. This application uses a synergistic heating device in conjunction with the induction brazing device to heat the welding wire section, which melts the welding wire 7 more efficiently, increases the automatic brazing cycle speed, and increases efficiency.

[0030] Example 1: like Figures 2-4 As shown, the synergistic heating device 2 of Embodiment 1 uses a preheating high-frequency induction coil wound on the surface of the wire feeding tube 51 to realize the generation of a high-frequency magnetic field by electromagnetic induction. The welding wire 7 in the wire feeding tube 51 is rapidly preheated by utilizing the skin effect and proximity effect. The wire feeding tube 51 is a hollow ceramic tube.

[0031] Process parameters: Preheating high-frequency induction coil current 15A, length approximately 25mm. When the temperature of welding wire 7 is 370°, welding wire 7 is bent without springing back, and the part of welding wire 7 exposed above the wire feeding tube end 511 is basically a straight cylinder, with a bending degree (the angle between the center line of the wire feeding tube and the line connecting the wire feeding tube end 511 and the welding wire 7 end 71) not greater than 10°.

[0032] The wire feeding speed is usually 1200 mm / min. When the welding wire 7 head end 71 enters the wire feeding tube 51 tail end 512, it is at room temperature. As it moves in the wire feeding tube 51, it is continuously heated. When it reaches the wire feeding tube 51 head end 511, the temperature is about 370℃. Then, after entering the effective range of the induction brazing device 3, it is rapidly heated to a molten state and falls into the welding area to complete the welding.

[0033] The welding process in Embodiment 1 of this application is as follows: S0: Preparation steps: All devices and components are installed. The workpiece 8 to be welded is installed on the workpiece fixture 4. Both sets of welding wires 7 are connected to their respective wire feeding tubes 51 through their respective welding wire machines. The welding wire tip 71 is located inside the wire feeding tube 51. The specific position can be calculated based on the distance that the welding wire tip needs to move to be exactly at the wire feeding tube tip 511 when heated to the set temperature of 370 degrees Celsius under the set preheating power (corresponding to the preheating rate) and set speed of the co-heating device. The distance between the initial position of the welding wire tip 71 and the wire feeding tube tip 511 = set speed × (set temperature - initial temperature of welding wire tip) × set preheating power of the co-heating device. Under thermal power, the heating rate of the welding wire tip (Formula 1, when working almost continuously, the temperature of the welding wire tip may be higher than the set temperature after one welding operation, that is, the result of the above calculation formula is negative. At this time, the welding wire tip is sent to the wire feeding tube 51 and a small section is exposed outside the wire feeding tube 51 to facilitate the infrared thermal imaging equipment to detect the real-time temperature. The welding wire tip is then pulled back to the wire feeding tube head 511 until the welding wire tip cools down to the set temperature and is then pulled back to the wire feeding tube head 511 to start the next welding operation). The length of the wire feeding tube 51 can ensure that when the welding wire tip of any type is sent from the wire feeding tube tail end 512 to the wire feeding tube head 511 at a set speed and set preheating power, the heating range is not less than the set temperature minus the initial temperature of the welding wire tip. Equipment initialization; S1: The co-heating device 2 and the induction brazing device 3 are started, respectively heating the part of the welding wire 7 located inside the wire feeding tube 51 and the workpiece 8 to be welded. The welding wire machine 1 starts the first section of wire feeding, and the welding wire head end 71 is conveyed from the initial position to the wire feeding tube head end 511. S2: Welding wire machine 1 starts the second stage of wire feeding, conveying the wire tip 71 to the welding area; S3: The tip of the welding wire enters the effective range of the induction brazing device 3 and continues to be heated. The welding wire machine 1 continues to feed the wire in the second stage, continuously sending the melting tip of the welding wire to the top of the molten pool to melt and fall into the molten pool or directly into the molten pool. S4: After the molten pool is filled or the specified brazing time is reached, the welding is completed. The induction brazing power supply 31 is turned off, the induction brazing coil 32 is turned on, the co-heating device 2 is turned off, the wire welding machine 1 pulls back the wire end, and removes the brazed workpiece 8.

[0034] In step S4, if there is no next welding operation for a long time, the wire tip 71 is pulled back into the wire feed tube 51. Before each welding operation, the wire tip can be fed to the wire feed tube tip 511 by the welding wire machine to check the real-time temperature and then calculate the value of Formula 1 to determine the initial position of the wire tip. If the next welding operation is to be started after a short interval, it is only necessary to pull the wire tip back to the wire feed tube 51 to expose a small section, so that the infrared thermal imaging equipment can detect the real-time temperature. The wire tip is then pulled back to the wire feed tube tip 511 after cooling to the set temperature, and the next welding operation can begin.

[0035] This application also includes step S21 in step S2, which is also applicable to the case of embodiment 2.

[0036] S21: The infrared thermal imaging (temperature detection) device 31 detects the real-time temperature of the wire tip 71 that has been exposed from the wire feeding tube tip 511 but has not yet entered the range of the induction brazing device and transmits it to the control device. The control device adjusts the heating power of the co-heating device 2 according to the real-time temperature, so that the temperature of the subsequent wire exposed from the wire feeding tube tip 511 is closer to the design value (370 degrees Celsius in special cases).

[0037] Example 2: like Figure 5 As shown, the synergistic heating device 2 of Embodiment 2 of this application uses a preheating heating wire wound on the surface of the wire feeding tube 51. The wire feeding tube 51 is a metal wire feeding tube 513 with good thermal conductivity (preferably an iron pipe, as long as it does not deform at 300-400 degrees Celsius) and a ceramic sleeve 514 as a connector. The inner diameter of the metal wire feeding tube 513 is 1.9-1.6 mm, the diameter of the welding wire 7 is 1.6 mm, and the distance from the head end 5131 of the metal wire feeding tube 513 to the head end 511 of the wire feeding tube is about 15-20 mm.

[0038] The preheating electric heating wire, which is densely wound on the metal wire feeding tube 613, is heated to 350 degrees. The heat is conducted through the metal wire feeding tube 513 to the welding wire 7 located inside it. The stress of the welding wire 7 is relieved, meaning that the bending degree of the part of the welding wire 7 exposed at the head end 511 of the wire feeding tube is no more than 10°.

[0039] Heating process and its parameters: S0: Preparation steps, all devices and components are installed, both sets of welding wires 7 are connected to their respective wire feeding tubes 51 through their respective welding wire machines, the initial position of the welding wire head 71 is located at the wire feeding tube head 511, equipment initialization; S1: The co-heating device and induction brazing device are activated; S11: Start the induction brazing device to heat the workpiece 8 to be welded, and at the same time start the co-heating device to heat the part of the welding wire located in the wire feeding tube 51. The preheating power of each co-heating device is 10kw. S12: First preheating time of welding wire (11s in special cases); S2: After the first preheating period of the welding wire is completed, the welding wire machine is started. The two sets of welding wire machines start the first stage of wire feeding at the same time. The welding wire 7 is fed out from the wire feeding tube end 511 at a feeding speed of 360mm / min. At this time, the preheating power of each set of co-heating devices is still 10kw. S3: [Hu Qixuan 1], continue the first section of silk feeding; S4: After heating normally for a period of time (except for the 15th second), the wire welding machine starts the second stage of wire feeding (at this time, the wire at the very front has begun to soften), [H2], (duration 4s); S5: In the third stage of wire feeding, the wire tip melts under the action of the induction brazing device 3 and flows into the welding area. The wire feeder 1 feeds the wire rapidly at a speed of 1000 mm / min for 3 seconds, continuously feeding the molten wire tip into the welding area to complete the welding. After the welding area is filled or the specified brazing time is reached, the induction brazing power supply 31 is turned off, the induction brazing coil 32 is turned on, and the wire feeder 1 retracts the wire tip.

[0040] Optionally, a layer of heat insulation / insulation material (such as asbestos) can be wrapped around the surface of the preheated heating wire to improve thermal efficiency and prevent waste.

[0041] Example 3: See Figure 6 This embodiment employs an energized short-circuit heating scheme: the co-heating device 2 uses a co-heating power supply 23 (1.5V; 170A). The negative terminal 232 of the co-heating power supply is connected to the end of the wire feeding tube 512, and the positive terminal 231 is connected to the workpiece fixture 4 made of conductive material. The workpieces 9 to be welded are mounted on the workpiece fixture 4 and electrically connected to each other. When the tip 71 of the welding wire 7 moves to contact the workpiece 9 to be welded, the section of the welding wire from the tip 71 to the end of the wire feeding tube 512 is energized to generate high temperature. This high temperature, combined with the induction welding heat energy generated by the induction brazing device 3, causes the tip 71 of the welding wire to melt and weld. Then, the two sets of welding wire machines continuously feed the welding wire 7 until the wire feeding amount reaches the set wire feeding amount required to weld one set of workpieces.

[0042] This embodiment uses short-circuit energization heating, so there is only one set of the co-heating device 2. There is no heating coil on the wire feeding tube 51, and the wire feeding tube 51 adopts the design of embodiment 2 (connector of metal wire feeding tube 513 and ceramic sleeve 514).

[0043] The end 512 of the wire feeding tube is provided with an electrical connection ring 5121 made of conductive material. The electrical connection ring 5121 is electrically connected to the negative terminal 232 of the co-heating power supply. The inner wall of the electrical connection ring 5121 is electrically connected to the outer diameter of the welding wire 7.

[0044] The welding method in Example 3 is as follows: S0: The preparation steps are the same as in Example 2; S1: Start the induction brazing device 3 and begin preheating the workpiece 8 to be welded (from the 0th second t1 to the 13th second t2, the workpiece 8 to be welded is preheated with preheating power under the action of the induction brazing coil 32, and the welding wire in the wire feeding tube 51 remains in the initial state (unheated). S2: First stage of wire feeding (starting at 13 seconds t2), the welding wire in the wire feeding tube 51 begins to be fed forward at a speed of V1 (1200mm / min); S3: When the tip of the welding wire enters the effective range 33 of the induction brazing device, the second stage of wire feeding begins (at the 14th second t3, the wire feeding speed remains unchanged). At this time, the welding wire entering the effective range 33 of the induction brazing device is heated until the tip of the welding wire reaches the surface of the workpiece to be welded (at the 15th second, the first and second stages each feed 20 mm of wire), and then the wire feeding stops. S4: The positive and negative terminals of the co-heating power supply 23 are connected, and the co-heating (powered-on) and induction heating begin to work together (starting at t4 after 15 seconds, which is when the tip of the welding wire contacts the surface of the workpiece, because there is a positive terminal 231 of the co-heating power supply below the workpiece being welded, and the welding wire is in contact with the negative terminal 232 of the co-heating power supply to form a power-on heating circuit, a current circuit (actually 170A) is formed from the tip of the welding wire to the section where the welding wire contacts the negative terminal 232 of the co-heating power supply, and the stage of the co-heating and induction heating working together begins). S5: The combined action of electric heating and induction heating continues for a period of time (starting from the 17th second t5). Due to the combined action of electric heating and induction heating, the stress in the section from the tip of the welding wire to the point where the welding wire contacts the negative electrode 232 of the cooperating heating power supply gradually disappears and the temperature rises, and the tip of the welding wire softens. S6: The third stage of wire feeding (starting at 18 seconds t6) involves slow wire feeding at a speed of v2 (900 mm / min). The temperature of the tip of the welding wire has begun to exceed the solidus of the material. The tip of the welding wire slowly begins to melt and falls into or immerses in the welding area (molten pool) until the end of this stage (23 seconds t7). S6: Fourth stage wire feeding (starting at 23 seconds t7), the wire is fed rapidly at a speed of v3 (1100mm / min). Since the molten pool is already partially filled at this time, the tip of the welding wire is directly immersed in the molten pool, which can quickly melt the tip of the welding wire until this stage ends (ending at 26 seconds t8). Wire feeding stops, and the co-heating device 2 and the induction brazing device 3 are turned off.

[0045] S7: (Starting at t9 at 27 seconds) Welding wire machine 1 pulls back the end of the welding wire.

[0046] The two sets of wire welding machines 1 in this application have the same structure and parameters, and the two sets of wire feeding devices 5 have the same structure and parameters; when the co-heating device 2 adopts the technical solutions of Embodiment 1 and Embodiment 2, its structure and parameters are the same. Each of the wire welding machine 1, wire feeding device 5 and co-heating device 2 (when there are two sets) described in this application is symmetrically arranged on one side of the workbench.

[0047] This application also includes a control device (not shown in the figure), which is connected to all electrical control devices (including wire welding machine 1, co-heating device 2, induction brazing device 3, and servo motor 6) and controls them to work according to a set sequence, thereby improving the degree of automation.

[0048] This application may also include an existing infrared thermal imaging (temperature detection) device (not shown in the figure). The infrared thermal imaging device is connected to the control device. The infrared thermal imaging device can accurately monitor the temperature of the workpiece during preheating and brazing, as well as the temperature signal of the exposed wire tip 71 of the wire feed tube. This allows for timely activation of the wire welding machine and / or adjustment of the wire feeding speed and / or real-time adjustment of the power output of the co-heating device 2, thereby improving the welding speed and the welding quality of the brazing process, and achieving digital and intelligent control.

Claims

1. A high-frequency induction brazing apparatus, comprising a wire welding machine, a co-heating device, an induction brazing device, a workpiece fixture, a wire feeding device, a servo motor, and a worktable, wherein the workpiece fixture, the wire feeding device, and the servo motor are all mounted on the worktable, characterized in that: The wire feeding device includes a wire feeding tube, a wire feeding tube fixing device, and a wire feeding table. The wire feeding table is mounted on a workbench, and the wire feeding tube fixing device is rotatably mounted on the wire feeding table. The wire feeding tube fixing device is connected to a servo motor. The workpiece to be welded is mounted on a workpiece fixture. The workpiece to be welded consists of two mutually cooperating sleeve structures, and a welding area for containing molten solder is formed between the two sleeve structures. A co-heating device is mounted on the wire feeding device. The welding wire machine connects the required welding wire to the wire feeding tube and delivers it to the welding area or above the welding area or electrically connects it to the workpiece to be welded. The co-heating device works in conjunction with the induction brazing device to heat the welding wire segment.

2. The high-frequency induction brazing equipment according to claim 1, characterized in that: It is also equipped with a control device, which is connected to the wire welding machine, the co-heating device, the induction brazing device, and the servo motor.

3. The high-frequency induction brazing equipment according to claim 2, characterized in that: It is also equipped with an infrared thermal imaging device, which is connected to the control device. The infrared thermal imaging device is used to collect the temperature of the workpiece being welded and the temperature of the end of the welding wire exposed on the wire feeding tube.

4. The high-frequency induction brazing equipment according to claim 3, characterized in that: The workpiece to be welded consists of two interlocking tubular sleeve structures, with an annular molten pool between the two tubular sleeve structures to contain the molten solder. The welding wire machine, wire feeding device, and welding wire are all in sets of two.

5. The high-frequency induction brazing equipment according to any one of claims 1 to 4, characterized in that: The synergistic heating device employs a preheating high-frequency induction coil wound around the outer surface of the wire feeding tube, which is a hollow ceramic tube.

6. A welding method for the high-frequency induction brazing equipment as described in claim 5, characterized in that... Includes the following steps: S0: Preparation steps, all devices and components are installed, the workpiece to be welded is installed on the workpiece fixture, the welding wire tip is connected to the wire feeding tube through the welding wire machine, the initial position of the welding wire tip and the wire feeding tube tip distance = set speed × (set temperature - initial temperature of welding wire tip)̸ set the heating rate of the welding wire tip under the preheating power of the co-heating device, and initialize the equipment; S1: The co-heating device and the induction brazing device are started, respectively heating the part of the welding wire located in the wire feeding tube and the workpiece to be welded. The welding wire machine starts the first stage of wire feeding, and the welding wire head is conveyed from the initial position to the head of the wire feeding tube. S2: The welding wire machine starts the second stage of wire feeding, conveying the welding wire tip to the welding area; S3: The tip of the welding wire enters the effective range of the induction brazing device and continues to be heated. The welding wire machine continues to feed the wire in the second stage, continuously sending the melting tip of the welding wire to the top of the molten pool to melt and fall into the molten pool or directly into the molten pool. S4: After the molten pool is filled or the specified brazing time is reached, the welding is completed. The induction brazing power supply is turned off, the induction brazing coil is turned on, the co-heating device is turned off, the wire welding machine pulls back the wire tip, and the brazed workpiece is removed.

7. The high-frequency induction brazing equipment according to any one of claims 1 to 4, characterized in that: The synergistic heating device uses a preheating heating wire wound on the outer surface of a metal wire feeding tube, which is a metal wire feeding tube and a ceramic sleeve.

8. A welding method for the high-frequency induction brazing equipment as described in claim 7, characterized in that... Includes the following steps: S0: Preparation steps, all devices and components are installed, the welding wire is connected to the wire feeding tube through the welding wire machine, the initial position of the welding wire head is at the head of the wire feeding tube, and the equipment is initialized; S1: The co-heating device and induction brazing device are activated; S11: Start the induction brazing device and the co-heating device. The heating power of the co-heating device is the preheating power. S12: Preheating for the first period of time; S2: After the first preheating period, start the wire welding machine. The wire welding machine starts the first stage of wire feeding, and the wire tip is fed out from the wire feeding tube. S3: When the preheating set time is up, the heating power of the co-heating device is switched to normal power, and the first section of wire feeding continues; S4: After heating normally for a period of time, the wire welding machine starts the second stage of wire feeding; S5: The third stage of wire feeding: the wire tip melts and flows into the welding area under the action of the induction brazing device to complete the welding. After the welding area is filled or the specified brazing time is reached, the induction brazing power supply is turned off, the induction brazing coil is turned on, and the wire welding machine pulls the wire tip back.

9. The high-frequency induction brazing equipment according to any one of claims 1 to 4, characterized in that: The co-heating device uses a co-heating power supply. The negative terminal of the co-heating power supply is connected to the tail end of the wire feeding tube, and the positive terminal of the co-heating power supply is connected to the workpiece fixture made of conductive material. The workpieces to be welded are installed on the workpiece fixture and electrically connected to each other. The welding wire is electrically connected to the tail end of the wire feeding tube. The wire feeding tube is made of metal wire feeding tube and ceramic sleeve.

10. A welding method for the high-frequency induction brazing equipment as described in claim 9, characterized in that... Includes the following steps: S0: Preparation steps, all devices and components are installed, the welding wire is connected to the wire feeding tube through the welding wire machine, the initial position of the welding wire head is at the head of the wire feeding tube, and the equipment is initialized; S1: Start the induction brazing device. The workpiece to be welded is preheated with preheating power under the action of the induction brazing coil. The welding wire in the wire feeding tube remains in its initial state. S2: The welding wire machine starts feeding welding wire in the first stage; S3: When the tip of the welding wire enters the effective range of the induction brazing device, the second stage of wire feeding begins until the tip of the welding wire reaches the surface of the workpiece to be welded, at which point the welding wire machine is turned off. S4: The positive and negative terminals of the co-heating power supply are connected, and the stage of co-heating and induction heating working together begins; S5: After a period of time, the stress in the section from the tip of the welding wire to the point where the welding wire contacts the negative electrode of the cooperating heating power supply gradually disappears and the temperature rises, and the tip of the welding wire softens. S6: The welding wire machine starts the third stage of wire feeding, and the tip of the welding wire melts and falls into or is immersed in the welding area; S6: The wire welding machine begins the fourth stage of wire feeding, and the tip of the wire is directly immersed in the molten pool formed by the molten wire. The wire welding machine, the co-heating device, and the induction brazing device are all turned off until this stage ends. S7: Start the welding wire machine and pull back the welding wire tip.

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