A continuous ultrasonic welding apparatus and method with active thermal management

Abstract

This invention provides a continuous ultrasonic welding apparatus and method with active thermal management, relating to the field of ultrasonic welding technology. The continuous ultrasonic welding apparatus and method with active thermal management includes: a support suspension fixedly mounted on the end face of a linear motion platform capable of linear reciprocating movement along the weld seam arrangement direction of the workpiece; at least two sets of actuators sequentially mounted and fixed on the support suspension, and the relative spacing between the actuators is flexibly adjusted by a matching adjustment mechanism. This invention solves the problem of pressure rollers gradually heating up, becoming thermally saturated, and even losing their cooling and shaping ability due to prolonged operation. It enables the pressure roller to apply effective cooling pressure to the molten zone promptly after the welding head is removed, allowing the material to cross the glass transition temperature more quickly and complete solidification and shaping. This reduces the probability of defects such as springback, warping, residual porosity, and delamination in the later stages of the weld, ensuring a more uniform forming quality and mechanical properties throughout the weld.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic welding technology, specifically to a continuous ultrasonic welding apparatus and method with active thermal management. Background Technology

[0002] Continuous Ultrasonic Welding (CUW), as a highly efficient, energy-saving, and environmentally friendly thermoplastic composite joining technology, has shown broad application prospects in aerospace, automotive lightweighting, and other fields in recent years. In a typical continuous welding process, the ultrasonic welding head moves at a constant speed along a predetermined weld seam trajectory. Its front end first applies dynamic pressure and inputs ultrasonic energy to the lap area, achieving rapid heating and fusion of the interface. As the welding head advances forward, the molten area behind it must immediately be subjected to continuous and stable solidification pressure to suppress springback, warping, or porosity formation caused by residual stress above the glass transition temperature (Tg), ensuring that the melt is fully densified and solidified during cooling. Therefore, an ideal continuous welding system not only requires precise control of energy input (amplitude, time) and dynamic pressure during the welding stage, but also requires immediate and constant cooling and pressurization of the weld seam through an independent compaction unit after the welding head is removed. This is crucial for ensuring the uniformity of long weld seam quality and structural integrity.

[0003] Existing continuous ultrasonic welding technologies for thermoplastic composites, taking patents CN121246251A and CN121083924A as examples, mainly focus on the microstructure treatment or process parameter optimization of the welding interface. However, when facing the welding of large-sized (length > 1 meter) long welds, the problem of heat accumulation becomes prominent: during long-distance continuous welding, the post-compacting components (such as metal rollers) are in contact with high-temperature molten resin for a long time, and heat accumulates continuously, causing the temperature of the compaction unit itself to rise continuously. Once its surface temperature approaches or exceeds the glass transition temperature (Tg) of the thermoplastic matrix, its cooling and shaping ability will decrease significantly, and it will be unable to effectively suppress material springback, thus causing obvious warping deformation, increased porosity, or even delamination in the later part of the weld, seriously affecting the mechanical properties and appearance consistency of the joint.

[0004] However, existing technologies largely focus on optimizing process parameters or modifying interfaces under short weld conditions, lacking systematic solutions for the collaborative control challenges in long weld applications for large-size components, particularly the thermal management and pressure decoupling mechanisms of the compaction unit. Therefore, there is an urgent need to develop a structurally sound and engineering-feasible continuous ultrasonic welding device and method that can effectively suppress heat accumulation, achieve independent control of welding and curing pressures, and possess good thickness adaptability, thereby improving the quality stability and reliability of continuous welding of large-size thermoplastic composite components. Summary of the Invention

[0005] Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a continuous ultrasonic welding device and method with active thermal management. This solves the problem of pressure rollers gradually heating up, becoming thermally saturated, or even losing their cooling and shaping capabilities due to prolonged operation. The invention enables the pressure rollers to apply effective cooling pressure to the molten zone promptly after the welding head leaves, allowing the material to cross the glass transition temperature more quickly and complete solidification. This reduces the probability of defects such as springback, warping, residual porosity, and delamination in the later stages of the weld, ensuring a more uniform forming quality and mechanical properties of the entire weld.

[0006] Technical solution

[0007] To achieve the above objectives, the present invention provides the following technical solution: a continuous ultrasonic welding apparatus with active thermal management, comprising: The support suspension is fixedly mounted on the end face of a linear motion platform that can reciprocate linearly along the direction of the workpiece weld seam. At least two sets of actuators are sequentially assembled and fixed on the support suspension, and the relative spacing between each set of actuators can be flexibly adjusted through a matching adjustment mechanism; The air knife heat insulation unit is installed inside the support suspension and positioned between the two sets of actuators; Among them, the two sets of actuators are respectively fixedly equipped with an ultrasonic welding knife and a cold pressing and shaping mechanism. The ultrasonic welding knife and the cold pressing and shaping mechanism are arranged in a front-to-back structure along the welding feed direction. The ultrasonic welding knife is located at the upstream position and the cold pressing and shaping mechanism is located at the downstream position. Both the ultrasonic welding knife and the cold pressing and shaping mechanism are slidably assembled on the inner wall of the support suspension through guide rail pairs. The cold pressing and shaping mechanism includes a cold pressing circulating rolling assembly composed of a follower pressure roller and a stationary injection shaft. The stationary injection shaft includes a stationary shaft body formed by an integral hollow tubular structure, and the internal cavity of the tube body forms a conveying channel for the flow of cooling medium. Along the direction of medium transport, the upstream and downstream ends of the stationary shaft are respectively equipped with a feed port and a discharge chute. The cooling medium is introduced into the internal flow channel of the stationary shaft through the feed port and finally discharged outward from the discharge chute to the outer area of ​​the stationary shaft. The follower pressure roller includes a pressure roller housing, and a central hole is machined at the axis of the follower pressure roller. The central hole forms a rotational fit structure with the stationary shaft. A return groove is opened on the outer surface of the pressure roller housing and the area around the central hole for the return of cooling medium. The pressure roller housing and the stationary shaft form a medium receiving cavity. After the cooling medium is discharged from the discharge chute, it flows into the cavity and is finally discharged through the return groove.

[0008] Preferably, the air knife heat insulation unit includes a flat air curtain nozzle and an angle adjustment mechanism. The angle adjustment mechanism is used to control the swing angle of the flat air curtain nozzle. The angle adjustment mechanism is fixedly mounted on the outer wall of the support suspension and mainly consists of a servo motor and a drive gear fixed to the output end of the motor. A driven gear that meshes with the drive gear is provided on the outer side of the flat air curtain nozzle. The angle adjustment and attitude locking of the flat air curtain nozzle are completed by relying on the gear meshing transmission structure.

[0009] Preferably, the stationary injection shaft is also equipped with a sealing seat, which is assembled at the feed end of the stationary shaft body. The pressure roller housing and the return groove form a rotational sealing fit structure by means of bearings, sealing components and stationary shaft body respectively. The sealing seat is equipped with an inlet for connecting an external cold source at its axial position, which can continuously and directionally deliver cooling medium into the interior of the stationary shaft. The outer wall of the sealing seat is also equipped with an outlet for discharging the cooling medium. The outlet is connected to the return groove, thereby completing the directional return and discharge of the cooling medium. The inlet end of the discharge trough is also equipped with a guide cone for guiding the cold source medium to diffuse towards the outer side of the discharge trough.

[0010] Preferably, vision mechanisms are fixedly installed on both sides of the support suspension and on both sides of the air knife heat insulation unit. The vision mechanisms are used to collect and monitor the appearance and state changes of the workpiece weld after passing through the air curtain formed by the air knife heat insulation unit in real time.

[0011] Preferably, support frames for supporting the rotation of the static injection shaft are installed on both sides. A piston cylinder and a fixed frame are provided between the support frame and the connected actuator. The top of the support frame and the inner wall of the piston cylinder form a limiting sliding fit. The cavity between the support frame and the piston cylinder is filled with liquid medium. A piston assembly is assembled on the rear side wall of the support suspension. The piston assembly can circulate and draw the liquid medium inside the cavity, and drive the support frame to perform reciprocating vibration motion by relying on the dynamic action of the hydraulic medium.

[0012] Preferably, a fixing frame is fixedly connected to the outer wall of the piston cylinder. The fixing frame consists of a suspension bracket and a toothed plate frame. The toothed plate frame is fixedly installed on the lower side of the suspension bracket and extends towards the cold-pressing circulating rolling assembly. The outer circular surface of the pressure roller housing is machined with concave tooth grooves. The tooth grooves and the toothed plate frame form a meshing structure. Secondly, no transmission gear structure is provided at the bottom of the toothed plate frame, so as not to interfere with the follow-up operation of the pressure roller housing.

[0013] Preferably, the fixing frame is further equipped with a wedge-shaped extrusion block, which is located at the feed end of the static injection shaft; The static injection shaft is equipped with a telescopic movable shaft that can be limited and slidable via a spring and a sealing assembly at its axial center position. The telescopic movable shaft includes a telescopic shaft body. A wedge-shaped slider is fixedly mounted on the side of the telescopic shaft body facing the wedge-shaped extrusion block. The wedge-shaped slider and the wedge-shaped extrusion block form an inclined surface fit structure. A guide seat is fixedly installed on the outer wall of the telescopic shaft body. A guide tube is fixedly connected to the outer wall of the stationary shaft body. A telescopic piston with a limit sliding is installed in the inner cavity of the guide tube. The end of the telescopic piston near the telescopic shaft body is slidably embedded in the inclined groove of the guide seat, forming a limit sliding fit.

[0014] Preferably, it includes the following steps: S1. Assemble the support suspension on the end face of the linear motion platform, complete the overall assembly of each group of actuators, air knife heat insulation unit, ultrasonic welding knife, cold pressing and shaping mechanism and vision mechanism, overlap and fix the workpiece to be welded, and lay the energy conducting layer to complete the pre-welding preparation.

[0015] S2. Adjust the distance between the two sets of actuators by adjusting the mechanism, set the working gap between the ultrasonic welding knife and the cold pressing and shaping mechanism and various welding process parameters, the linear motion platform drives the whole equipment to move forward, the upstream actuator drives the ultrasonic welding knife to press down, and the workpiece overlap position is heated and melted by ultrasonic vibration energy.

[0016] S3. The air knife heat insulation unit sprays an air curtain through a flat air curtain nozzle to pre-cool the weld and block heat transfer between processes. The angle adjustment mechanism adaptively adjusts the nozzle spray angle, and the vision mechanisms on both sides monitor the weld morphology after the air curtain is applied in real time to identify abnormal defects such as weld displacement and deformation.

[0017] S4. The cold pressing and shaping mechanism compacts the normal weld seam by rolling the follow-up pressure roller, while the static injection shaft introduces a circulating cold source medium to continuously remove the heat of operation, suppress the formation of weld seam pores and resin rebound, and ensure the normal forming quality of the weld seam.

[0018] S5. When the vision mechanism detects an abnormal weld, the control system drives the piston assembly to draw in liquid medium, which in turn drives the cold-pressed circulating rolling assembly to vibrate up and down, flexibly compacting and correcting the abnormal weld. At the same time, the follow-up pressure roller achieves active rotation through the meshing of the tooth groove and the toothed plate frame, using the combined action of vibration and rolling to optimize the flatness and structural density of the weld.

[0019] S6. During the lifting and lowering of the follow-up pressure roller, the wedge-shaped extrusion block, telescopic movable shaft and telescopic piston work together to complete the suction and high-speed spray of the cold source medium, splashing and cleaning the molten welding material attached to the inner wall of the pressure roller shell and cooling it at the same time; the equipment continues to move and operate, and the system finely adjusts the process parameters in real time based on visual inspection feedback until all welding operations are completed.

[0020] This invention provides a continuous ultrasonic welding apparatus and method with active thermal management. It possesses the following key technical features and beneficial effects: 1. Automatic cooling of the pressing components is achieved through the circulating flow of the cold source medium. This enables continuous active heat dissipation during continuous rolling, allowing the roller to continuously remove heat from the interface between the molten resin and the high-temperature workpiece during long-stroke welding. This prevents the roller from gradually heating up, becoming thermally saturated, or even losing its cooling and shaping ability due to prolonged operation. Consequently, the roller can apply effective cooling pressure to the molten zone promptly after the welding head leaves, allowing the material to cross the glass transition temperature more quickly and complete solidification. This reduces the probability of defects such as springback, warping, residual porosity, and delamination in the later stages of the weld, ensuring a more uniform weld formation quality and mechanical properties.

[0021] 2. Vision mechanisms deployed on both sides of the support suspension monitor the weld surface morphology in real time after air curtain purging, accurately identifying abnormal defects such as weld misalignment and deformation. When a weld abnormality is detected, the control component drives the piston assembly to circulate and draw the liquid medium between the support frame and the piston cylinder, causing the cold-pressed circulating rolling assembly to vibrate up and down at high frequency. Simultaneously, relying on the meshing transmission structure between the toothed groove on the outer wall of the follower pressure roller and the toothed plate frame of the fixed frame, the follower pressure roller achieves synchronous active rotation during vibration, forming a composite compaction condition of vibration kneading and rolling. This adaptive control method can specifically correct forming defects such as weld unevenness, wrinkles, and incomplete joints, effectively compacting the internal structure of the weld, eliminating local stress concentration, and solving the problems of easy rebound of molten resin, high weld porosity, and poor forming consistency in traditional ultrasonic welding. It significantly improves weld density, surface flatness, and overall structural load-bearing strength.

[0022] 3. Utilizing high-speed fluid impact force, residual welding material adhering to the pressure roller surface due to high-temperature melting during the welding process can be efficiently removed. Simultaneously, the low-temperature medium continuously cools the pressure roller body, reducing the probability of molten resin adhesion at the source. This mechanical self-cleaning structure requires no additional cleaning components and can complete the cleaning and cooling processes simultaneously during the welding operation, ensuring a clean and flat pressure roller surface throughout the process. This avoids problems such as weld indentations, unevenness, and compaction misalignment caused by material adhesion. No manual cleaning is required to stop the machine, effectively improving continuous welding efficiency and reducing equipment maintenance costs and workpiece scrap rate. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the working state of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention; Figure 3 This is a schematic diagram of the bottom structure of the present invention; Figure 4 This is a schematic diagram of the structure of the hidden sheet metal part supporting the suspension in this invention; Figure 5 This is a schematic diagram of the pressure regulating electric cylinder, piston assembly, and cold pressing and shaping mechanism in this invention; Figure 6 for Figure 5 An isometric side sectional view; Figure 7 This is an exploded view of the cold pressing and shaping mechanism in this invention; Figure 8 This is an isometric side sectional view of the cold pressing and shaping mechanism in this invention.

[0024] The components include: 1. Support suspension; 2. Actuator; 3. Ultrasonic welding knife; 4. Flat air curtain nozzle; 5. Cold pressing and shaping mechanism; 6. Piston assembly; 7. Vision mechanism; and 8. Angle adjustment mechanism. 51. Cold-pressed circulating rolling assembly; 511. Follower pressure roller; 5111. Pressure roller housing; 5112. Tooth groove; 5113. Return groove; 5114. Center hole; 512. Stationary injection shaft; 5121. Stationary shaft body; 5122. Discharge chute; 5123. Guide cone; 5124. Guide tube; 5125. Sealing seat; 5126. Feed port; 5127. Discharge port; 513. Telescopic movable shaft; 5131. Telescopic shaft body; 5132. Guide seat; 5133. Telescopic piston; 5134. Wedge-shaped slider; 52. Support frame; 53. Piston cylinder; 54. Fixing frame; 541. Suspension bracket; 542. Wedge-shaped extrusion block; 543. Toothed plate frame. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example, reference Figure 2 and Figure 3As shown, this embodiment of the invention provides a continuous ultrasonic welding device and method with active thermal management, comprising: a support suspension 1, fixedly mounted on the end face of a linear motion platform capable of linear reciprocating along the weld seam arrangement direction of the workpiece; at least two sets of actuators 2, sequentially mounted and fixed on the support suspension 1, and the relative spacing between each set of actuators 2 is flexibly adjusted through a matching adjustment mechanism; an air knife heat insulation unit, installed inside the support suspension 1 and positioned between the two sets of actuators 2; wherein, the actuating ends of the two sets of actuators 2 are respectively fixedly mounted with an ultrasonic welding knife 3 and a cold pressing and shaping mechanism 5, the ultrasonic welding knife 3 and the cold pressing and shaping mechanism 5 are arranged in a front-to-back structure along the welding feed direction, the ultrasonic welding knife 3 is located at the upstream position, the cold pressing and shaping mechanism 5 is located at the downstream position, and both the ultrasonic welding knife 3 and the cold pressing and shaping mechanism 5 are slidably mounted on the inner wall of the support suspension 1 through a guide rail pair.

[0027] refer to Figures 1 to 3 As shown, the support suspension 1 is a rigid load-bearing component used to simultaneously support the ultrasonic welding knife 3 and the cold pressing and shaping mechanism 5, ensuring that the two maintain a relatively stable spatial position during the welding process. It is preferably formed by integral processing of steel plate, aluminum alloy plate or other high rigidity plate, and its thickness is preferably 15-40mm to reduce the bending deformation under welding pressure. In the welding direction, the ultrasonic welding knife 3 is located upstream and the cold pressing and shaping mechanism 5 is located downstream, thus forming a continuous process chain of front-end heating and melting and rear-end compaction and cooling. The distance between the ultrasonic welding knife 3 and the cold pressing and shaping mechanism 5 is adjustable, preferably characterized by the minimum gap from the rear edge of the welding head to the front edge of the pressure roller, preferably 1-5mm, more preferably 2-3mm; or characterized by the wheelbase from the center of the welding head to the center of the pressure roller, preferably 15-60mm, which can be adjusted according to the size of the welding head, the diameter of the pressure roller and the thickness of the workpiece.

[0028] When laying the workpieces to be welded, the workpieces are overlapped and fixed on the tooling platform. At the same time, a conductive layer is laid on top of the workpieces to be welded. The conductive layer is preferably a PPS film, a PPS woven mesh, or a flat resin layer, and its thickness is preferably 0.05–0.12 mm. Then, the entire device is driven along the required welding direction by a linear motion platform, which can be a gantry linear motion platform or an industrial robot end effector.

[0029] Both sets of actuators 2 can be selected from cylinders, electric cylinders or servo presses. More preferably, the upstream actuator 2 is a cylinder with a proportional pressure regulating valve, and the downstream actuator 2 is a cylinder or a spring-loaded damping structure. The two sets of actuators 2 control the up-and-down movement of the ultrasonic welding knife 3 and the cold pressing and shaping mechanism 5 and the relevant pressure of the corresponding welded parts, so as to achieve mechanical decoupling and independent control of welding pressure and curing pressure.

[0030] In some embodiments, reference Figures 5 to 8 As shown, the cold pressing and shaping mechanism 5 includes a cold pressing circulating rolling assembly 51 composed of a follower pressure roller 511 and a stationary injection shaft 512. The stationary injection shaft 512 includes a stationary shaft body 5121 formed by an integral hollow tubular structure. The internal cavity of the tube body forms a conveying channel for the flow of cooling medium. Along the medium conveying direction, the upstream and downstream ends of the stationary shaft body 5121 are respectively equipped with a feed port 5126 and a discharge trough 5122. The cooling medium is introduced into the internal flow channel of the stationary shaft body 5121 through the feed port 5126 and finally discharged outward from the discharge trough 5122 to the stationary shaft body 5121. The outer region of the shaft body 5121; while the follower pressure roller 511 includes a pressure roller housing 5111, and a central hole 5114 is machined at the axial position of the follower pressure roller 511. The central hole 5114 and the stationary shaft body 5121 form a rotational fit structure; a return groove 5113 is opened on the outer surface of the pressure roller housing 5111 and the area around the central hole 5114 for the return of cooling medium. The pressure roller housing 5111 and the stationary shaft body 5121 enclose a medium receiving cavity. After the cooling medium is discharged from the discharge groove 5122, it flows into the cavity and is finally discharged through the return groove 5113.

[0031] refer to Figures 5 to 8 As shown, after the cold source medium enters the stationary shaft body 5121, it diffuses through the discharge groove 5122 into the cavity of the pressure roller housing 5111 and the stationary shaft body 5121, thereby absorbing the heat obtained during the compaction process, and then flowing back out through the return groove 5113 to realize the circulation of the medium. Since the stationary shaft body 5121 and the pressure roller housing 5111 are in a rotating fit relationship, when the pressure roller housing 5111 slides on the surface of the welding material, it will compact the surface of the welding material by rolling, thereby ensuring that the molten area can still maintain sufficient normal constraint after the welding head leaves, thereby reducing the formation of pores and resin rebound.

[0032] In this process, the upstream actuator 2 drives the ultrasonic welding knife 3 to apply welding pressure to the workpiece and inputs ultrasonic vibration energy to the lap interface. The welding pressure is preferably 300–1000N, more preferably 400–800N. For a CF / PPS material system with a thickness of about 2mm and an lap width of 20–25mm, the preferred welding pressure range is 500–700N. The welding speed is preferably 2–8mm / s, more preferably 3–5mm / s. This parameter range helps to ensure sufficient heat input while avoiding over-welding or excessive resin extrusion. In some embodiments, the upstream actuator 2 can be linked with a displacement sensor to control the displacement according to a preset upper limit. When the ultrasonic welding knife 3 reaches the preset value, it automatically stops pressing down or enters a holding state to improve the repeatability of the welding process.

[0033] The cooling medium can be water, ethylene glycol aqueous solution, or cooling oil, preferably deionized water or low-temperature circulating water. The preferred temperature of the cooling medium is 10–25℃, and the preferred flow rate is 0.2–1.0 L / min. For continuous CF / PPS welding, the preferred flow rate range is 0.3–0.8 L / min. The specific parameters can be adjusted according to the thickness, width, and material properties of the material being welded. A sensor for monitoring the surface temperature of the pressure roller housing 5111 can be installed on the outside of the pressure roller housing 5111. Based on the sensor feedback parameters, the flow rate of the cooling medium is adjusted to achieve temperature control of the pressure roller housing 5111.

[0034] In some embodiments, reference Figure 4 As shown, the air knife heat insulation unit includes a flat air curtain nozzle 4 and an angle adjustment mechanism 8. The angle adjustment mechanism 8 is used to control the swing angle of the flat air curtain nozzle 4. The angle adjustment mechanism 8 is fixedly mounted on the outer wall of the support suspension 1 and mainly consists of a servo motor and a drive gear fixed to the output end of the motor. A driven gear that meshes with the drive gear is provided on the outer side of the flat air curtain nozzle 4. The angle adjustment and attitude locking of the flat air curtain nozzle 4 are completed by the gear meshing transmission structure. The angle adjustment mechanism 8 can drive the flat air curtain nozzle 4 to swing to achieve air curtain spraying at different angles, adapting to different plate thicknesses and spatial layout requirements. The sprayed air curtain can not only pre-cool the material surface, but also isolate the mutual transfer of heat.

[0035] In some embodiments, reference Figure 7 and Figure 8 As shown, the stationary injection shaft 512 is also equipped with a sealing seat 5125, which is mounted at the feed end of the stationary shaft body 5121. The pressure roller housing 5111 and the return groove 5113 form a rotating seal fit structure with the support of the bearing, the sealing assembly and the stationary shaft body 5121 respectively. The sealing seat 5125 is equipped with a feed port 5126 for connecting to an external cold source at the axial position, which can continuously and directionally deliver cooling medium into the interior of the stationary shaft body 5121. The outer wall of the sealing seat 5125 is also equipped with a discharge port 5127 for discharging the cooling medium. The discharge port 5127 is connected to the return groove 5113 to complete the directional return and discharge of the cooling medium. The feed end of the discharge groove 5122 is also equipped with a guide cone 5123 for guiding the cold source medium to diffuse towards the outer groove of the discharge groove 5122.

[0036] refer to Figure 8 As shown, the cold source medium enters the stationary shaft body 5121 through the feed port 5126, and then diffuses to the outside through the discharge channel 5122. The guide cone 5123 can guide the liquid to diffuse to the outside, reducing the kinetic energy loss of the liquid flow. Finally, the liquid enters the discharge port 5127 through the return channel 5113 to realize the overall circulation process.

[0037] In some embodiments, reference Figure 3 and Figure 4 As shown, vision mechanisms 7 are fixedly installed on both sides of the support suspension 1 and on both sides of the air knife heat insulation unit. The vision mechanisms 7 are used to collect and monitor the appearance and state changes of the workpiece weld after passing through the air curtain formed by the air knife heat insulation unit. The vision mechanisms 7 on both sides can monitor the surface morphology of the weld after being blown by the flat air curtain nozzle 4, and capture the subtle changes in the appearance of the weld in real time. If the weld shows abnormal conditions such as shape deviation or deformation after the air curtain is applied, it can be determined that there is a processing defect in the weld. The system can provide feedback signals to guide the subsequent cold pressing and compaction process to adjust the operation parameters and working status in a timely manner, optimize the compaction operation effect, and effectively improve the overall structural strength and forming quality of the weld.

[0038] In some embodiments, reference Figure 5 and Figure 6 As shown, support frames 52 for supporting the rotation of the static injection shaft 512 are installed on both sides. A piston cylinder 53 and a fixed frame 54 are provided between the support frame 52 and the connected actuator 2. The top of the support frame 52 forms a limiting sliding fit with the inner wall of the piston cylinder 53. The cavity between the support frame 52 and the piston cylinder 53 is filled with liquid medium. A piston assembly 6 is assembled on the rear side wall of the support suspension 1. The piston assembly 6 can circulate and draw the liquid medium inside the cavity, and drive the support frame 52 to rotate by the dynamic action of the hydraulic medium. The piston cylinder 53 is subjected to reciprocating vibration. A fixed frame 54 is fixedly connected to the outer wall of the piston cylinder 53. The fixed frame 54 consists of a suspension bracket 541 and a toothed plate frame 543. The toothed plate frame 543 is fixedly installed on the lower side of the suspension bracket 541 and extends towards the cold-pressed circulating rolling assembly 51. The outer circular surface of the pressure roller housing 5111 is machined with a concave toothed groove 5112. The toothed groove 5112 and the toothed plate frame 543 form a meshing structure. The bottom end of the toothed plate frame 543 does not have a transmission gear structure, so it will not interfere with the follow-up operation of the pressure roller housing 5111.

[0039] refer to Figure 7 As shown, when the vision mechanism 7 detects an abnormality in the surface morphology of the weld, the control component drives the piston assembly 6 to operate. The piston assembly 6 continuously draws the liquid medium between the support frame 52 and the piston cylinder 53, causing the cold pressure circulating rolling assembly 51 to vibrate up and down. This vibration can dynamically and flexibly compact the abnormal weld, which can smooth the unevenness of the weld surface, correct deformation defects, improve the internal material bonding density of the weld, eliminate local stress concentration, further strengthen the overall structural strength of the weld, and ensure the quality of the weld formation. While the follower pressure roller 511 vibrates up and down, during its upward movement, the outer wall toothed groove 5112 meshes with the toothed plate frame 543, driving the follower pressure roller 511 to rotate. During the downward movement, it also relies on the meshing structure to achieve autonomous rotation. The follower pressure roller 511 vibrates and rotates continuously, creating a combined effect of rolling and dynamic pressing on the weld, uniformly compacting the surface and internal structure of the weld, eliminating local protrusions, wrinkles, and incomplete connections, resulting in a more balanced stress distribution on the weld. This further improves the weld density and surface smoothness, strengthening the weld's bonding strength and consistency. Among them, when the actively rotating follower pressure roller 511 presses against the weld surface, its rotation speed gradually decreases until it is driven to rotate passively again. At this time, it is driven upward by the piston assembly 6 to realize the reciprocating compaction of the weld. Depending on the surface morphology of the weld, different reciprocating speeds can be selected for compaction. Specific parameters can be obtained from a limited number of experiments.

[0040] In some embodiments, reference Figure 7 and Figure 8 As shown, the fixed frame 54 is also equipped with a wedge-shaped extrusion block 542, which is located at the feeding end of the stationary injection shaft 512. The stationary injection shaft 512 is equipped with a telescopic movable shaft 513 with limited sliding via a spring and a sealing assembly at its axial center. The telescopic movable shaft 513 includes a telescopic shaft body 5131, and a wedge-shaped slider 5134 is fixedly installed on the side of the telescopic shaft body 5131 facing the wedge-shaped extrusion block 542. The wedge-shaped slider 5134 and the wedge-shaped extrusion block 542 form an inclined surface fit structure. A guide seat 5132 is fixedly installed on the outer wall of the telescopic shaft body 5131, and a guide tube 5124 is fixedly connected to the outer wall of the stationary shaft body 5121. A telescopic piston 5133 with limited sliding is installed in the internal cavity of the guide tube 5124. The end of the telescopic piston 5133 near the telescopic shaft body 5131 is slidably embedded in the inclined groove of the guide seat 5132, forming a limited sliding fit.

[0041] refer to Figure 7 As shown, during the upward movement of the follower pressure roller 511, the wedge-shaped extrusion block 542 pushes the telescopic movable shaft 513 to slide towards the feed port. When the telescopic movable shaft 513 moves, it drives the telescopic piston 5133 to slide towards the telescopic shaft body 5131 through the guide seat 5132, drawing some of the cold source medium into the guide tube 5124. When the follower pressure roller 511 moves downward, the telescopic shaft body 5131 quickly returns to its original position under the action of the spring force, synchronously driving the telescopic piston 5133 to reset. The telescopic piston 5133 pushes the cold source medium in the guide tube 5124 out at high speed and sprays it onto the inner wall of the pressure roller housing 5111.

[0042] After ultrasonic welding, the workpiece will generate high-temperature molten welding material. The abnormal welding material may have a certain degree of stickiness and is easy to adhere to the surface of the follower pressure roller 511 during cold pressing and shaping. The high-speed sputtering impact of the above-mentioned cold source medium can peel off the residual welding material adhering to the surface of the follower pressure roller 511 by means of fluid impact force. At the same time, the low temperature medium can also cool the pressure roller body, further reducing the probability of molten welding material adhesion, ensuring the surface of the pressure roller is clean, and avoiding foreign matter from affecting the weld compaction accuracy and forming quality.

[0043] Includes the following steps: S1. Fix the support suspension 1 to the end face of the linear motion platform that can move back and forth in a straight line along the weld seam arrangement direction of the workpiece, and complete the assembly of at least two sets of actuators 2, air knife heat insulation unit, ultrasonic welding knife 3, cold pressing and shaping mechanism 5 and vision mechanism 7; overlap and fix the workpiece to be welded on the tooling platform, and lay the energy conducting layer on the workpiece to complete the pre-welding preparation work. S2. The distance between the two sets of actuators 2 is adjusted by the adjustment mechanism, thereby setting the working gap between the ultrasonic welding knife 3 and the cold pressing and shaping mechanism 5; process parameters such as welding pressure, welding speed, cold source medium temperature and flow rate, and air outlet angle of the air knife heat insulation unit are preset; the linear motion platform drives the device to move along the weld direction; the upstream actuator 2 drives the ultrasonic welding knife 3 to press down, inputting ultrasonic vibration energy to the workpiece lap interface to realize the heating and melting welding of the workpiece; S3, the flat air curtain nozzle 4 of the air knife heat insulation unit sprays an air curtain to pre-cool the surface of the welded workpiece and at the same time isolate the heat of the ultrasonic welding knife 3 from being conducted to the cold pressing and shaping mechanism 5; the angle adjustment mechanism 8 adjusts the spray angle of the flat air curtain nozzle 4 according to the workpiece specifications to adapt to the welding requirements; the vision mechanism 7 on both sides of the support suspension 1 collects the surface morphology of the weld after being blown by the air curtain in real time, captures the subtle changes in the weld morphology, and judges whether there are abnormal defects such as shape deviation and deformation in the weld. S4. The follow-up pressure roller 511 of the cold pressing and shaping mechanism 5 rolls and compacts the normal weld. The cold source medium circulates inside the static injection shaft 512, continuously absorbing the heat of the pressure roller and the weld, reducing the formation of weld pores and resin rebound, and maintaining the stability of weld forming. S5. When the vision mechanism 7 detects an abnormal weld morphology, the control component drives the piston assembly 6 to work, circulating and sucking the liquid medium between the support frame 52 and the piston cylinder 53, driving the cold pressure circulating rolling assembly 51 to vibrate up and down, dynamically and flexibly compacting the abnormal weld, correcting weld deformation, improving weld density and structural strength. During the up and down vibration of the follower pressure roller 511, its outer wall tooth groove 5112 meshes with the toothed plate frame 543 of the fixed frame 54, realizing the active rotation of the follower pressure roller 511; the combined action of rotation and vibration on the weld, uniformly rolling the weld structure, eliminating weld protrusions and wrinkles, and optimizing the surface flatness and stress uniformity of the weld. S6. When the follower pressure roller 511 rises, the wedge-shaped extrusion block 542 drives the telescopic movable shaft 513 to slide, and draws the cold source medium into the guide tube 5124 through the guide seat 5132. When the follower pressure roller 511 falls, the telescopic movable shaft 513 is reset under the action of the spring, and the telescopic piston 5133 splashes the cold source medium at high speed onto the inner wall of the pressure roller housing 5111, peeling off the attached molten welding material and reducing the temperature of the pressure roller, ensuring that the surface of the pressure roller is clean. The device moves linearly to complete the continuous welding operation. The vision mechanism 7 continuously feeds back the weld status. The system adjusts the vibration frequency of the piston assembly 6, the flow rate of the cold source medium, and other parameters in real time according to the monitoring results until all workpieces are welded.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A continuous ultrasonic welding apparatus with active thermal management, characterized in that, include: The support suspension (1) is fixedly assembled on the end face of the linear motion platform that can make linear reciprocating movements along the weld seam arrangement direction of the workpiece; At least two sets of actuators (2) are sequentially assembled and fixed on the support suspension (1), and the relative spacing between each set of actuators (2) is flexibly adjusted by the matching adjustment mechanism; The air knife heat insulation unit is installed inside the support suspension (1) and mounted in the middle of the two sets of actuators (2); Among them, the two sets of actuators (2) are respectively fixed with ultrasonic welding knife (3) and cold pressing shaping mechanism (5). The ultrasonic welding knife (3) and cold pressing shaping mechanism (5) are arranged in a front-to-back structure along the welding feed direction. The ultrasonic welding knife (3) is in the upstream position of travel, and the cold pressing shaping mechanism (5) is in the downstream position of travel. Both the ultrasonic welding knife (3) and the cold pressing shaping mechanism (5) are slidably assembled on the inner wall of the support suspension (1) through the guide rail pair. The cold pressing shaping mechanism (5) includes a cold pressing circulating rolling assembly (51) composed of a follower pressure roller (511) and a stationary injection shaft (512). The stationary injection shaft (512) includes a stationary shaft body (5121) formed by an integral hollow tubular structure, and the internal cavity of the tube body forms a conveying channel for the flow of cooling medium. Along the direction of medium transport, the upstream and downstream ends of the stationary shaft (5121) are respectively equipped with a feed port (5126) and a discharge chute (5122). The cooling medium is introduced into the internal flow channel of the stationary shaft (5121) through the feed port (5126) and finally discharged outward from the discharge chute (5122) to the outer area of ​​the stationary shaft (5121). The follower pressure roller (511) includes a pressure roller housing (5111). A central hole (5114) is machined at the axial position of the follower pressure roller (5111). The central hole (5114) and the stationary shaft (5121) form a rotational fit structure. A return groove (5113) for the cooling medium to return is opened on the outer surface of the pressure roller housing (5111) and the area around the central hole (5114). The pressure roller housing (5111) and the stationary shaft (5121) enclose a medium receiving cavity. The cooling medium is discharged from the discharge chute (5122) and flows into the cavity. Finally, it is discharged through the return groove (5113).

2. The continuous ultrasonic welding apparatus with active thermal management according to claim 1, characterized in that, The air knife heat insulation unit includes a flat air curtain nozzle (4) and an angle adjustment mechanism (8). The angle adjustment mechanism (8) is used to control the swing angle of the flat air curtain nozzle (4). The angle adjustment mechanism (8) is fixedly mounted on the outer wall of the support suspension (1) and mainly consists of a servo motor and a drive gear fixed to the output end of the motor. A driven gear that meshes with the drive gear is provided on the outer side of the flat air curtain nozzle (4). The angle adjustment and attitude locking of the flat air curtain nozzle (4) are completed by relying on the gear meshing transmission structure.

3. The continuous ultrasonic welding apparatus with active thermal management according to claim 1, characterized in that, The static injection shaft (512) is also equipped with a sealing seat (5125), which is assembled at the feed end of the static shaft body (5121). The pressure roller housing (5111) and the return groove (5113) form a rotational sealing fit structure by means of bearings, sealing components and static shaft body (5121). The sealing seat (5125) is equipped with an inlet (5126) for connecting to an external cold source at the axial position, which can continuously and directionally deliver cooling medium into the interior of the stationary shaft (5121). The outer wall of the sealing seat (5125) is also equipped with an outlet (5127) for discharging the cooling medium. The outlet (5127) is connected to the return groove (5113) to complete the directional return and discharge of the cooling medium. The discharge trough (5122) is also equipped with a guide cone (5123) at the feeding end for guiding the cold source medium to diffuse towards the outer side of the discharge trough (5122).

4. The continuous ultrasonic welding apparatus with active thermal management according to claim 1, characterized in that, Vision mechanisms (7) are fixedly installed on both sides of the support suspension (1) and on both sides of the air knife heat insulation unit. The vision mechanisms (7) are used to collect and monitor the appearance and state changes of the workpiece weld after passing through the air curtain formed by the air knife heat insulation unit.

5. A continuous ultrasonic welding apparatus with active thermal management according to claim 1, characterized in that, The static injection shaft (512) is equipped with support frames (52) on both sides to support its rotation. The support frame (52) and the connected actuator (2) are provided with piston cylinder (53) and fixed frame (54). The top of the support frame (52) and the inner wall of the piston cylinder (53) form a limiting sliding fit. The cavity between the support frame (52) and the piston cylinder (53) is filled with liquid medium. The rear side wall of the support suspension (1) is equipped with piston assembly (6). The piston assembly (6) can circulate and suck the liquid medium inside the cavity. The support frame (52) is driven to reciprocate and vibrate by the dynamic action of the hydraulic medium.

6. A continuous ultrasonic welding apparatus with active thermal management according to claim 5, characterized in that, The piston cylinder (53) is fixedly connected to a fixing frame (54) on its outer wall. The fixing frame (54) consists of a suspension bracket (541) and a toothed plate frame (543). The toothed plate frame (543) is fixedly installed on the lower side of the suspension bracket (541) and extends toward the cold-pressed circulating rolling assembly (51). The outer circular surface of the pressure roller housing (5111) is machined with a concave toothed groove (5112). The toothed groove (5112) and the toothed plate frame (543) form a meshing structure. The bottom end of the toothed plate frame (543) is not equipped with a transmission gear structure, so it will not interfere with the rotation of the pressure roller housing (5111).

7. A continuous ultrasonic welding apparatus with active thermal management according to claim 6, characterized in that, The fixed frame (54) is also equipped with a wedge-shaped extrusion block (542), which is located at the feeding end of the static injection shaft (512); The static injection shaft (512) is equipped with a telescopic movable shaft (513) that can be limited and slidable via a spring and sealing assembly at its axial center position. The telescopic movable shaft (513) includes a telescopic shaft body (5131). A wedge-shaped slider (5134) is fixedly mounted on the side of the telescopic shaft body (5131) facing the wedge-shaped extrusion block (542). The wedge-shaped slider (5134) and the wedge-shaped extrusion block (542) form an inclined surface fit structure. A guide seat (5132) is fixedly installed on the outer wall of the telescopic shaft body (5131). A guide tube (5124) is fixedly connected to the outer wall of the stationary shaft body (5121). A telescopic piston (5133) with a limit sliding is installed in the inner cavity of the guide tube (5124). The end of the telescopic piston (5133) near the telescopic shaft body (5131) is slidably embedded in the inclined groove of the guide seat (5132) and forms a limit sliding fit.

8. A welding method using the continuous ultrasonic welding apparatus with active thermal management as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Assemble the support suspension (1) on the end face of the linear motion platform and complete the overall assembly of each set of actuators (2), air knife heat insulation unit, ultrasonic welding knife (3), cold pressing and shaping mechanism (5) and vision mechanism (7); lap and fix the workpiece to be welded, and lay the energy-conducting layer to complete the pre-welding preparation. S2. Adjust the distance between the two sets of actuators (2) by adjusting the mechanism, set the working gap between the ultrasonic welding knife (3) and the cold pressing shaping mechanism (5) and various welding process parameters, the linear motion platform drives the equipment to move as a whole, the upstream actuator (2) drives the ultrasonic welding knife (3) to press down, and the workpiece overlap position is heated and melted by ultrasonic vibration energy. S3. The air knife heat insulation unit sprays an air curtain through the flat air curtain nozzle (4) to pre-cool the weld and block the heat transfer between processes. The angle adjustment mechanism (8) adaptively adjusts the nozzle spray angle. The two side vision mechanisms (7) monitor the weld morphology after the air curtain action in real time and identify abnormal defects such as weld offset and deformation. S4. The cold pressing and shaping mechanism (5) rolls and compacts the normal weld seam through the follow-up pressure roller (511), while the static injection shaft (512) introduces the circulating cold source medium to continuously remove the heat of operation, suppress the formation of weld seam pores and resin rebound, and ensure the normal forming quality of the weld seam. S5. When the vision mechanism (7) detects an abnormal weld, the control system drives the piston assembly (6) to draw liquid medium, which drives the cold pressure circulating rolling assembly (51) to vibrate up and down to flexibly compact and correct the abnormal weld. At the same time, the follow-up pressure roller (511) meshes with the toothed plate frame (543) through the tooth groove (5112) to achieve active rotation, thereby optimizing the weld flatness and structural density through the combined action of vibration and rolling. S6. During the lifting and lowering process of the follow-up pressure roller (511), the wedge-shaped extrusion block (542), the telescopic movable shaft (513) and the telescopic piston (5133) work together to complete the suction and high-speed spray of the cold source medium, splashing and cleaning the molten welding material attached to the inner wall of the pressure roller shell (5111) and cooling it simultaneously; the equipment continues to move and operate, and the system adjusts the process parameters in real time based on visual inspection feedback until all welding operations are completed.

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