High frequency induction brazing apparatus

Abstract

The application relates to a high-frequency induction brazing device which comprises a welding wire machine, a cooperative heating device, an induction brazing device, a workpiece tool, a wire feeding device, a servo motor and a workbench. 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 rotatably installed on the wire feeding table, the wire feeding pipe fixing device is connected with the servo motor, a workpiece to be welded is installed on the workpiece tool, the workpiece to be welded is composed of two mutually matched sleeve structures, the cooperative heating device is installed on the wire feeding device, the welding wire machine connects required welding wire into the wire feeding pipe and feeds the welding wire to the welding area or above the welding area, and the cooperative heating device cooperates with the induction brazing device to heat the welding wire section. The application has the advantages of simple structure, convenient use, efficient melting of the welding wire and realization of digital and intelligent control.

Description

Technical Field

[0001] This application relates to a high-frequency induction brazing device, which is mainly suitable for high-efficiency melting of 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 device 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 platform. The wire feeding platform is mounted on the worktable, and the wire feeding tube fixing device is rotatably mounted on the wire feeding platform. 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 transports it to the welding area or above the welding area. 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 wire feeding tube is made of metal and a ceramic sleeve. The ceramic sleeve prevents the wire tip from being overheated and ensures good directionality after the wire tip comes out of the ceramic sleeve head (nozzle). The ceramic sleeve is a hollow cone shape, and the inner diameter of the ceramic sleeve head matches the diameter of the welding wire.

[0010] The metal wire feeding tube is a hollow round iron tube.

[0011] The synergistic heating device uses a preheated heating wire wound around the outer surface of a metal wire feeding tube.

[0012] Optionally, a layer of heat insulation / insulation material can be wrapped around the preheating heating wire to improve thermal efficiency and prevent waste.

[0013] 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.

[0014] This application features a simple structure, ease of use, and efficient melting of welding wire, achieving digital and intelligent control. Attached Figure Description

[0015] Figure 1 This is a top view of an embodiment of the present application.

[0016] Figure 2 This is a schematic diagram of the principle of Embodiment 1 of this application.

[0017] Figure 3 yes Figure 2 A magnified view of a portion of the image.

[0018] 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.

[0019] Figure 5 This is a schematic diagram of the principle of Embodiment 2 of this application.

[0020] 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; 3. Induction brazing device; 31. Induction brazing power supply; 32. Induction brazing coil; 33. Working range of induction brazing device (induction brazing coil); 4. Workpiece fixture; 5. Wire feeding device; 5 1. Wire feed tube; 511. Wire feed tube head end; 512. Wire feed tube tail end; 513. Metal wire feed tube; 5131. Metal wire feed tube head end; 514. Ceramic sleeve; 52. Wire feed tube fixing device; 53. Wire feed table; 6. Servo motor; 7. Welding wire; 71. Welding wire head end; 8. Workpiece to be welded; 81. Outer workpiece to be welded; 812. Welding area formed between two workpieces to be welded to accommodate molten welding wire, a small area within the effective range of the induction brazing device, specifically the periphery of the molten pool or weld; 82. Inner workpiece to be welded. Detailed Implementation

[0021] 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.

[0022] like Figures 1-5As 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 preheats the welding wire, melts the welding wire 7 more efficiently, increases the automatic brazing cycle speed, and increases efficiency.

[0023] 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.

[0024] 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°.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] This application also includes an S21 step in step S2.

[0029] 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 wire exposed from the wire feeding tube tip 511 is closer to the design value.

[0030] 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.

[0031] 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°.

[0032] 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.

[0033] 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.

[0034] 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 installed on the 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 installed on the 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 installed 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. 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 in 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 welding area between the two tubular sleeve structures to accommodate molten solder. The welding wire machine, wire feeding device, and welding wire are all in two sets.

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. 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.

7. The high-frequency induction brazing equipment according to claim 6, characterized in that: The preheating heating wire is covered with a layer of heat insulation or heat preservation material.

8. The high-frequency induction brazing equipment according to claim 6, characterized in that: The ceramic sleeve is a hollow cone shape, and the inner diameter of the head of the ceramic sleeve matches the diameter of the welding wire.

9. The high-frequency induction brazing equipment according to claim 6, characterized in that: The metal wire feeding tube is a hollow round iron tube.

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