A heterogeneous metal inertia friction welding preheating apparatus and method of use

Abstract

The application provides a heterogeneous metal inertia friction welding preheating device and a use method, which is composed of a heating tower and a main machine. The heating tower comprises an inductor, an inductor retraction device, an infrared inductive probe and an electromagnetic fixing base; the main machine comprises an induction power supply, a display panel and a controller. The operation steps of the application are as follows: step A, fixing the heating tower; step B, setting the heating frequency and the end face expected temperature, and heating the end face of the welding piece; step C, temperature monitoring, when the end face expected temperature is reached, the inductor retraction device is started, and the two welding pieces start to perform friction welding. The application has the following characteristics: firstly, the two welding pieces of different metal materials can be inductively preheated and temperature controlled before inertia friction welding, compared with direct rotation friction heating of the two welding pieces, the application has the advantages of faster heating speed, controllable heating temperature, more uniform end face temperature distribution, etc. Moreover, the inductive heating is non-contact heating, and the energy storage of the inertia disc can be performed at the same time of heating, without affecting the normal inertia friction welding process. Secondly, the application is adsorbed on the machine base through the electromagnetic base, and is convenient to disassemble and assemble, without affecting the clamping of the welding piece.

Description

Technical Field

[0001] This invention relates to the field of inertial friction welding, and is a device for induction preheating of dissimilar metal weldments and its usage method. Background Technology

[0002] Dissimilar metal inertial friction welding is a modern metal welding method that enables the welding of two different types of metals at high efficiency. In this method, a hydraulic system applies pressure between the two metals on the workpiece, generating high-speed film shear expansion. This causes the workpiece to rub against each other from one side, heating, melting, and mixing the metals at the contact surfaces. The process does not involve melting and requires no additional materials to complete the weld.

[0003] Compared to traditional welding methods such as spot welding, argon arc welding, and resistance welding, friction welding has the following advantages.

[0004] 1. Friction welding can be completed without heating or at low heating levels, avoiding problems such as deformation, cracking, and deterioration caused by high temperatures. 2. The stirring effect generated during friction welding results in finer metal grains at the weld, improving weld strength and sealing. 3. Friction welding is easily automated, enabling robotic and production line automation. 4. Friction welding produces little or no welding slag and emits harmful gases, meeting environmental protection requirements. 5. Friction welding can be used for welding thin plates, dissimilar metals, and joining difficult-to-weld materials. In summary, compared to traditional welding methods, friction welding has significant advantages in production efficiency, weld strength, and environmental protection, and is therefore widely used in industries such as aerospace, automotive manufacturing, and railways.

[0005] Although friction welding has many advantages, it also presents some technical challenges.

[0006] 1. Controlling welding parameters is challenging. Different metals, thicknesses, and welding methods require different parameters such as rotation speed, force, and time. Selecting appropriate parameters is crucial for obtaining high-quality welds. 2. Unstable surface quality after welding. Due to the low frictional heat, the surface is prone to roughness or irregular protrusions. This can affect aesthetics and is a limitation in high-end industries such as aerospace and automotive. 3. Restrictions on part shape and size. The size of parts for friction welding is best kept below 10mm. Otherwise, larger sizes will reduce conductivity, making it impossible to guarantee a perfect weld connection. 4. Requirements for metal purity. Rough surfaces or impurities can affect the strength and durability of the bond. Therefore, metal workpieces must undergo rigorous treatment to ensure a smooth surface and remove all contaminants. 5. Noise and vibration. During friction welding, the equipment may generate noise and mechanical vibration, which can affect the health and comfort of operators. Summary of the Invention

[0007] To overcome the above difficulties, a preheating process was introduced to preheat the welding end surface to near its melting point.

[0008] 1. It can directly overcome the shortcomings of previous friction welding processes, such as low frictional heat and uneven heat distribution. 2. The physical state of the end face is changed, reducing the breaking force required for friction welding and improving noise and vibration levels. 3. Impurities on the end face are more easily precipitated, indirectly improving the surface finish and resulting in better weld quality. 4. It is more convenient to weld large-diameter components.

[0009] In order to achieve a rapid and efficient preheating effect, the present invention provides an induction preheating device and method for dissimilar metal weldments, which can heat weldments such as shafts, discs, and tubes by adjusting the heating power and heating time.

[0010] The technical principle of the preheating device for inertial friction welding of dissimilar metals of the present invention is as follows.

[0011] A dual high-frequency power supply is used to pass a high-frequency current through the inductor, which rapidly heats the end faces of the two dissimilar metal weldments, placing them simultaneously in a thermoplastic or slightly molten state. Subsequently, the inductor automatically exits the processing area, and the moving end weldment squeezes and rubs against the rotating end weldment. The metal in the preheated area of ​​the weldment end face undergoes plastic deformation, and the impurities and oxide layer at the original end face are extruded radially to form flash. The remaining clean metal comes into close contact under the action of upsetting force and forms an effective bond through interfacial diffusion and recrystallization.

[0012] The design features of a preheating device for inertial friction welding of dissimilar metals according to the present invention are as follows.

[0013] This invention provides a preheating device and method for inertial friction welding of dissimilar metals, comprising a heating tower and a main unit. The heating tower includes an inductor, an inductor retraction device, an infrared temperature measuring camera, and an electromagnetic mounting base. The main unit includes an induction power supply, a display panel, and a controller.

[0014] When the electromagnetic mounting base switch is turned on, the base generates a magnetic force, firmly attracting the metal guide rail at the bottom of the moving end of the inertial friction welding machine. When the electromagnetic mounting base switch is turned off, the magnetic force disappears. This design facilitates the installation of the heating tower.

[0015] The inductor consists of two heating coils and a central magnetic coil. The magnetic coil's function is to ensure that the magnetic field generated by the heating coils, which are powered by alternating current of different frequencies, heats only the end face of the corresponding metal workpiece. This design can meet the requirement that dissimilar metals reach the temperature for friction welding simultaneously.

[0016] The method for setting the heating frequency and expected end-face temperature is to input the physical properties of the metal weldment (such as melting point and resistivity), heating depth, and end-face shape into the host controller, and the host will automatically generate the heating frequency and expected end-face temperature.

[0017] An infrared temperature measuring device is installed on the heating tower and aimed at the end face of the metal weldment. The detected end face temperature can be displayed on the main unit's display panel. When the expected end face temperature is reached, the trigger of the sensor retraction device opens, the sensor falls, and a spring at the bottom of the retraction device can cushion the impact of the fall.

[0018] The present invention also discloses an operating method for a preheating device for inertial friction welding of dissimilar metals.

[0019] First, before performing inertial friction welding, open the electromagnetic mounting base and fix the heating tower on the base of the moving end of the inertial friction welding machine. Control the movement of the moving end of the inertial friction welding machine to maintain a suitable heating distance between the inductor and the end faces of the two metal weldments.

[0020] Then, the rotating end of the inertial friction welding machine begins to rotate and store energy. At the same time, the main unit of the preheating device is turned on, the heating time and the expected end face temperature are set, and the two high-frequency power supplies in the main unit pass high-frequency alternating current through the corresponding inductors to induce current on the end faces of the two metal weldments. The heating effect of the electric eddy current is used to heat the end faces of the metal weldments.

[0021] Then, during the preheating process, the infrared sensor on the heating tower monitors the temperature of the metal weldment end face. When the detected end face reaches the expected temperature, the host will control the sensor retraction device to move, so that the sensor retracts outside the processing area, the preheating ends, and the two metal weldments begin friction welding.

[0022] Finally, after the inertial friction welding is completed, if welding needs to continue, simply pull out the inductor in the heating tower after the workpiece is secured, and then repeat the previous steps. If welding is no longer needed, simply turn off the electromagnetic mounting base and remove the preheating device. Attached Figure Description

[0023] Figure 1 Schematic diagram of the preheating equipment for inertial friction welding of dissimilar metals.

[0024] Figure 2 : Schematic diagram of preheating equipment installation.

[0025] Figure 3 : Schematic diagram of sensor working principle.

[0026] Figure 4 Schematic diagram of the sensor retraction device.

[0027] Figure 5 Flowchart of inertial friction welding of dissimilar metals.

[0028] In the diagram: 1. Moving end. 2. Inertial storage device. 3. Rotating end chuck. 4. Metal weldment A. 5. Sensor. 5-1. Insulator. 5-2. Moving end heating coil. 5-3. Ring-shaped magnetic conductor. 5-4. Rotating end heating coil. 6. Metal weldment B. 7. Moving end chuck. 8. Moving end. 9. Tailstock. 10. Hydraulic moving device. 11. Moving guide rail. 12. Moving end slide. 13. Infrared temperature measurement camera. 14. Electromagnetic mounting base. 15. Main unit. 16. Data cable. 17. Sensor retraction device. Specific implementation methods

[0029] To perform inertial friction welding of dissimilar metals, many different tools and parts are required. These processes demand certain skills and experience from workers to ensure the quality and integrity of the weld. This invention provides the steps, tools, and safety guidelines for dissimilar metal inertial friction welding throughout the process.

[0030] Implementation steps.

[0031] Step 1: Clean the end faces of metal weldment A (4) and metal weldment B (6) to make them clean, smooth, and free of oil stains, rust and other dirt. Clamp the weldment on the rotating end chuck (3) and the moving end chuck (7) respectively, so that the center lines of metal weldment A (4) and metal weldment B (6) are on the same axis. Place the preheating device on the sliding seat (12) of the moving end, turn on the electromagnetic fixing seat (14) switch, pull out the sensor (5) of the preheating device, start the hydraulic moving device (10) to move the moving end (8) and keep the sensor (5) at a suitable heating distance from the end faces of the two metal weldments.

[0032] Step 2: On the control end of the inertial friction welding machine, set the friction time and pressure according to the type of metal workpiece and production requirements. On the main unit (15) of the preheating device, input the physical properties of the metal weldment (such as melting point, resistivity), heating depth and end face shape, and set the heating frequency and expected end face temperature.

[0033] Step 3: Start the inertial friction welding machine, so that the inertial energy storage device (2) starts to rotate and store energy, start the preheating device, so that the two high-frequency power supplies inside the main unit (15) of the preheating device respectively pass AC power of different frequencies to the rotating end heating coil (5-4) and the moving end heating coil (5-2). Because the magnetic conductor in the inductor (5) is composed of two ring magnetic conductors (5-3) and an insulator (5-1), it can ensure that the magnetic fields of different intensities generated by the rotating end heating coil (5-4) and the moving end heating coil (5-2) will not interfere with each other, so as to achieve the requirement that the dissimilar metals reach the expected friction welding temperature at the same time.

[0034] Step 4: The infrared temperature measurement camera (13) on the preheating device transmits the real-time temperature of the end faces of metal weldment A (4) and metal weldment B (6) to the host (15). When the expected temperature is reached, the host (15) sends a signal to the sensor retraction device (17). The trigger (17-1) inside the sensor retraction device retracts the sensor (5) and it falls down, and is caught by the spring (17-2) at the bottom of the sensor retraction device.

[0035] Step 5: After preheating is completed, the moving end (8) moves under the action of the hydraulic moving device (10) so that the end faces of metal weldment A (4) and metal weldment B (6) come into contact. Through friction, the end face temperature of the weldment can be made more uniform, thus improving the weld quality.

[0036] Step 6: The hydraulic moving device (10) pushes the moving end (8) to generate a small displacement and upsetting force. When the rotating end (1) stops rotating, the rotating end chuck (3) and the moving end chuck (7) are released. The completed weldment is taken out, and the weld quality is checked. The inertial friction welding of dissimilar metals is completed.

[0037] Step 7: After the inertial friction welding is completed, if welding needs to continue, simply pull out the inductor (5) in the heating tower after the workpiece is fixed, and then repeat the previous steps. If welding does not need to continue, simply turn off the electromagnetic mounting base (14) and remove the preheating device.

[0038] Precautions for inertial friction welding of dissimilar metals.

[0039] 1. During welding operations, always pay attention to the control panel to ensure that the pressure and temperature are at the appropriate levels.

[0040] 2. When welding involves high temperature and high pressure, appropriate personal protective equipment such as goggles, gloves, and protective clothing must be worn. Ensure that the equipment and work area are clean and free of debris, and ensure that all protective equipment is in accurate and effective condition.

[0041] 3. After the welding process is completed, the equipment and workpiece need to be cleaned to ensure its stability and durability.

[0042] 4. For the process parameters of inertial friction welding of dissimilar metals, the production procedures and standards must be strictly followed to ensure that the manufactured products meet the specified quality standards.

[0043] 5. Any abnormalities that occur during welding operations, such as noise, color changes, and current fluctuations, should be stopped immediately, and maintenance and repairs should be considered to ensure the stability and durability of the operation process.

Claims

1. A method for using a preheating device for inertial friction welding of dissimilar metals, characterized in that... The preheating equipment for dissimilar metal inertial friction welding consists of two parts: a heating tower and a main unit. The heating tower includes an inductor, an inductor retraction device, an infrared temperature measuring camera, and an electromagnetic mounting base. The main unit includes an induction power supply, a display panel, and a controller. The operating steps are as follows: Step 1: Clean the end faces of metal weldment A (4) and metal weldment B (6) to make them clean, smooth, and free of oil and rust. Clamp the weldment on the rotating end chuck (3) and the moving end chuck (7) respectively, so that the center lines of metal weldment A (4) and metal weldment B (6) are on the same axis. Place the preheating device on the slide (12) of the moving end, turn on the switch of the electromagnetic fixing seat (14), pull out the sensor (5) of the preheating device, start the hydraulic moving device (10) to move the moving end (8), and keep the sensor (5) at a suitable heating distance from the end faces of the two metal weldments. Step 2: On the control end of the inertial friction welding machine, set the friction time and pressure according to the metal type of the workpiece and the production requirements. On the main unit (15) of the preheating device, input the melting point, resistivity, heating depth and end face shape of the metal weldment. The main unit will automatically generate the heating frequency and the expected end face temperature. Step 3: Start the inertial friction welding machine, so that the inertial energy storage device (2) starts to rotate and store energy, start the preheating device, so that the two high-frequency power supplies inside the main unit (15) of the preheating device respectively pass AC power of different frequencies to the rotating end heating coil (5-4) and the moving end heating coil (5-2). Because the magnetic conductor in the inductor (5) is composed of two ring magnetic conductors (5-3) and an insulator (5-1), it can ensure that the magnetic fields of different intensities generated by the rotating end heating coil (5-4) and the moving end heating coil (5-2) will not interfere with each other, so as to achieve the requirement that the dissimilar metals reach the expected friction welding temperature at the same time. Step 4: The infrared temperature measurement camera (13) on the preheating device transmits the real-time temperature of the end faces of metal weldment A (4) and metal weldment B (6) to the host (15). When the expected temperature is reached, the host (15) sends a signal to the sensor retraction device (17). The trigger (17-1) inside the sensor retraction device retracts the sensor (5) and it falls down, and is caught by the spring (17-2) at the bottom of the sensor retraction device. Step 5: After preheating is completed, the moving end (8) moves under the action of the hydraulic moving device (10) so that the end faces of metal weldment A (4) and metal weldment B (6) come into contact. Through friction, the end face temperature of the weldment can be made more uniform, thus improving the weld quality. Step 6: The hydraulic moving device (10) pushes the moving end (8) to generate a small displacement and upsetting force. When the rotating end (1) stops rotating, the rotating end chuck (3) and the moving end chuck (7) are released. The completed weldment is taken out, and the weld quality is checked. The inertial friction welding of dissimilar metals is completed. Step 7: After the inertial friction welding is completed, if welding needs to continue, simply pull out the inductor (5) in the heating tower after the weldment is fixed, and then repeat the previous steps; if welding does not need to continue, simply turn off the electromagnetic fixing seat (14) and the preheating device can be removed.

2. The method of using a preheating device for heterogeneous metal inertial friction welding according to claim 1, characterized in that... In step one, when the electromagnetic fixing seat switch is turned on, the base can generate magnetic force, firmly attracting the metal guide rail at the bottom of the moving end of the inertial friction welding machine. When the electromagnetic fixing seat switch is turned off, the magnetic force disappears, facilitating the installation of the heating tower.

3. The method of using a preheating device for inertial friction welding of dissimilar metals according to claim 1, characterized in that... In step three, the inductor consists of two heating coils and a central magnetic ring. The magnetic ring's function is to ensure that the magnetic field generated by the heating coils, which are powered by alternating current of different frequencies, heats only the end face of the corresponding metal workpiece, thus meeting the requirement that dissimilar metals simultaneously reach the temperature required for inertial friction welding.

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