A method of ultrasonic welding of CFRTP components

Abstract

This application provides a side-mounted ultrasonic welding method for CFRTP components, used for butt welding of mutually compatible target welding end faces of two CFRTP components. The method includes: aligning the target welding end faces of the two CFRTP components and pressing them together with a welding plate made of CFRTP material, wherein the area of ​​the main surface of the welding plate is larger than the area of ​​the target welding end face, and after pressing, the projection area of ​​the target welding end face on the main surface is located inside the main surface; during the pressing of the welding plate, an ultrasonic welding head moves in the vibration transmission region and applies vertical high-frequency vibration to the vibration transmission region, wherein the vibration transmission region is the area on the main surface located outside the projection area; and removing the portion corresponding to the vibration transmission region from the welded component. The technical solution of this application can achieve robust welding of non-thin plate CFRTP components.

Description

Technical Field

[0001] This application relates to the field of composite material processing and manufacturing technology, and specifically to ultrasonic welding technology for carbon fiber reinforced thermoplastic composite components, providing a side ultrasonic welding method for CFRTP components. Background Technology

[0002] As a lightweight, high-strength, and recyclable advanced composite material, carbon fiber reinforced thermoplastic polymer (CFRTP) has been widely used in aerospace, new energy vehicles, and high-end equipment. As one of the core materials for achieving structural weight reduction and performance upgrades, how to achieve reliable and efficient connection of CFRTP materials has become a research focus and important development direction in the field of composite materials both domestically and internationally in recent years. Among them, ultrasonic welding has outstanding advantages such as high efficiency, cleanliness and environmental protection, flexible process, and easy automation of production, and is currently one of the most suitable reliable connection technologies for CFRTP.

[0003] When welding CFRTP materials using ultrasonic welding technology, the ultrasonic welding head makes close contact with the surface of the workpiece under welding pressure, transmitting high-frequency (20kHz~40kHz), low-amplitude longitudinal mechanical vibrations to the welding interface. Under the synergistic effect of mechanical pressure and high-frequency vibration, the resin matrix enriched at the welding interface undergoes intense high-frequency internal friction (viscoelastic loss) and interfacial friction, generating concentrated heat. This causes the interface layer temperature to rapidly rise above the resin melting point, resulting in localized melting. Under holding pressure, the molten resin interpenetrates and diffuses, encapsulating adjacent carbon fibers. After cooling and solidification, a firmly bonded welded region is formed, with the resin matrix as the continuous phase and the carbon fibers as the reinforcing phase.

[0004] Because the high-frequency mechanical vibration of the ultrasonic welding head needs to be transmitted from the welding head-workpiece contact surface to the workpiece-workpiece interface to be welded, and the viscoelastic damping and fiber anisotropy of CFRTP in the thickness direction (i.e. vibration propagation direction) will cause significant vibration energy attenuation, the welding quality deteriorates sharply as the component thickness increases. This limitation of the process means that the existing ultrasonic welding process is mainly applicable to thin-walled CFRTP components, and the reliable connection of thick-walled structures is still a technical problem that needs to be solved. Summary of the Invention

[0005] This application provides a side-mounted ultrasonic welding method for CFRTP components through embodiments, used for welding mutually compatible target welding end faces of two CFRTP components, including: The positioning and pressurizing operation aligns the target welding end faces of two CFRTP components and presses them together with a welding plate made of CFRTP material. The area of ​​the main surface of the welding plate is larger than the area of ​​the target welding end face, and after pressing, the projection area of ​​the target welding end face on the main surface is located inside the main surface. In a side-mounted ultrasonic welding operation, while the welding plate is being pressed, the ultrasonic welding head moves in the vibration transmission area and applies vertical high-frequency vibration to the vibration transmission area, wherein the vibration transmission area is the area on the main surface located outside the projection area. The post-processing operation involves removing the portion corresponding to the vibration transmission area from the welded component.

[0006] Preferably, the thickness of the CFRTP component along the direction perpendicular to the target welding interface is greater than 6 mm.

[0007] Preferably, after the welding plate is pressed down until the welding is completed, the projected area is always subjected to a preset pressing force, the pressure range of which is 15psi-30psi.

[0008] Preferably, the frequency range of the vertical high-frequency vibration of the ultrasonic welding head is 20kHz to 40kHz; and the thickness of the welding plate is 2mm to 5mm.

[0009] Optionally, the CFRTP component has an annular target welding end face; the welding plate is an annular plate, the inner contour shape of which is consistent with the inner contour shape of the target welding end face; the positioning and pressurizing operation further includes aligning the inner contour of the welding plate with the inner contour of the target welding end face.

[0010] Preferably, the side ultrasonic welding method for the CFRTP component further includes: during the period when the ultrasonic welding head applies vertical high-frequency vibration to the vibration transmission area, providing support for the edge of the vibration transmission area by a support plate, wherein the support portion does not coincide with the projection position of the ultrasonic welding head on the welding plate.

[0011] Preferably, the supporting plate does not directly contact the vibration transfer area before the ultrasonic welding head begins to vibrate vertically at high frequency.

[0012] Preferably, the side ultrasonic welding operation consists of two stages, wherein after the first stage of side ultrasonic welding is completed, the two CFRTP components are flipped over and re-pressed, and then the second stage of side ultrasonic welding is performed.

[0013] Preferably, the side ultrasonic welding method for the CFRTP component further includes: arranging a plurality of energy-conducting ribs on the target welding end face and the projected area, wherein the arrangement density of the energy-conducting ribs gradually decreases from the center of the target welding end face outward.

[0014] The side-mounted ultrasonic welding method for CFRTP components provided in this application addresses the inherent drawback of excessive energy loss and difficulty in improving welding results when using existing vertical vibration transmission methods for ultrasonic welding of thick, non-thin CFRTP components, due to the viscoelastic properties of the CFRTP material. This method utilizes a separately added plate of the same material to construct the vibration transmission area, and uses side-mounted ultrasonic vibration to change the vibration energy transmission from vertical to the interface direction to the target welding area, thereby significantly reducing vibration energy loss and avoiding potential damage to the component body caused by increasing the amplitude or vibration application time. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an existing ultrasonic welding process for CFRTP materials. Figure 2 This is a schematic diagram of the process for another existing ultrasonic welding process for CFRTP materials. Figure 3 A schematic diagram illustrating the principle of existing ultrasonic welding processes for CFRTP materials; Figure 4 This is a schematic diagram of two CFRTP components having mutually compatible target welding end faces according to one embodiment; Figure 5 This is a schematic diagram of two CFRTP components having mutually compatible target welding end faces according to another embodiment; Figure 6 A schematic diagram illustrating the defect mechanism of ultrasonic welding of non-thin CFRTP components using existing CFRTP material ultrasonic welding processes. Figure 7 This is a flowchart of a side ultrasonic welding method for a CFRTP component according to an embodiment of this application; Figure 8 This is a schematic diagram of the positioning and pressurization operation process in one embodiment of this application; Figure 9 This is a schematic diagram of a side ultrasonic welding operation process in one embodiment of this application; Figure 10 This is a schematic diagram of the post-processing operation in one embodiment of this application; Figure 11 This is a schematic diagram of the side ultrasonic welding operation process under the condition of setting a support plate in one embodiment of this application; Figure 12 This is a schematic diagram illustrating the cooperation between the support plate and the welding plate during positioning and alignment operations and side ultrasonic welding operations, in one embodiment of this application. Figure 13 This is a schematic diagram of the positioning and pressurization operation process in one embodiment of this application; Figure 14 This is a schematic diagram of a side ultrasonic welding operation process in one embodiment of this application; Figure 15 This is a schematic diagram of the complete component obtained after the post-processing operation in one embodiment of this application; Figure 16 This is a schematic diagram illustrating a two-stage welding process in a side-mounted ultrasonic welding operation, as shown in one embodiment. Figure 17 This is a schematic diagram of energy-conducting ribs arranged between the target welding end face and the welding plate in one embodiment.

[0016] Numbers in the diagram Ultrasonic welding head 1, thin plate CFRTP component 21, thin plate CFRTP component 22, CFRTP component 31, target welding end face 311, CFRTP component 32, target welding end face 321, CFRTP component 33, target welding end face 331, CFRTP component 34, target welding end face 341, CFRTP component 35, CFRTP component 36, target welding end face 361, welding plate 41, main surface 411, main surface 412, projection area 413, vibration transmission area 414, welding plate 42, main surface 421, main surface 422, projection area 423, vibration transmission area 424, projection area 433, vibration transmission area 434, fixed area 51, fixed area 52, support plate 61, support plate 62, energy guiding rib 7. Detailed Implementation

[0017] The present application will now be further described based on preferred embodiments and with reference to the accompanying drawings.

[0018] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product of this application is in use, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, in the description of this application, the terms "first," "second," etc., are used to distinguish different units, but these are not limited by the manufacturing order, nor should they be construed as indicating or implying relative importance. Their names may differ in the detailed description and claims of this application. In addition, for ease of understanding, various components in the drawings have been enlarged or reduced, but this is not intended to limit the scope of protection of this application.

[0019] The vocabulary used in this specification is for illustrative purposes and is not intended to limit the scope of this application. It should also be noted that, unless otherwise expressly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection via an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of these terms in this application.

[0020] Existing ultrasonic welding technologies for CFRTP materials To clearly illustrate the technical solution of this application, a brief introduction to the commonly used ultrasonic welding technology for CFRTP materials will be given first.

[0021] Carbon fiber reinforced thermoplastic polymer (CFRTP) is an advanced composite material with thermoplastic resin (such as PA66) as the matrix and carbon fiber as the reinforcement. Because the thermoplastic matrix of CFRTP has the property of softening when heated, ultrasonic welding technology can be used to achieve effective connection between CFRTP components.

[0022] Figure 1 An existing ultrasonic welding process for CFRTP materials is shown, such as Figure 1As shown, the thin-plate CFRTP components 21 and 22 to be welded are aligned and positioned by a clamping and positioning mechanism. The interfaces to be welded in the two components are brought into contact with each other to form the target welding interface. The ultrasonic welding system outputs a high-frequency electrical signal (20kHz to 40kHz) in the ultrasonic frequency band through a high-frequency power module. Utilizing the inverse piezoelectric effect of the transducer, the high-frequency electrical signal is converted into mechanical vibration of the same frequency. Then, the amplitude of the mechanical vibration is amplified by an amplitude transformer and transmitted to the ultrasonic welding head 1. The ultrasonic welding head 1, as a precision vibration output end, is in close contact with the workpiece surface under welding pressure, transmitting high-frequency, small-amplitude vertical mechanical vibration in a direction perpendicular to the target welding interface to the contact surface of the thin-plate CFRTP components 21 and 22 for ultrasonic welding operation. Figure 1 The process used is spot welding, which means that after each welding point is completed, the ultrasonic welding head is raised and moved to the next point, then lowered and the welding operation is continued at that point.

[0023] In addition, to ensure the welding effect, during the ultrasonic welding process, the ultrasonic welding head 1 first completes the alignment according to the preset parameters and applies initial pre-pressure to the workpiece, and then starts ultrasonic vibration. After the ultrasonic welding operation stage is completed, static pressure is generally applied to the ultrasonic welding head, that is, the pressure holding stage is entered. This can compact the fused interface, promote the effective discharge of residual air, eliminate pore defects, and allow the molten resin to be fully spread and compacted under pressure.

[0024] Figure 2 This illustrates another existing ultrasonic welding process for CFRTP materials, which is similar to... Figure 1 The difference lies in the fact that, by adopting a continuous welding method, the ultrasonic welding head 1 no longer lifts, moves, or lowers during the welding process. Instead, it continuously translates and vertically vibrates on the surface of the thin-plate CFRTP component 21, thereby applying continuous ultrasonic welding operations to the area where the continuous path it passes through is projected onto the target welding interface.

[0025] Figure 3 It shows the use of Figure 1 and Figure 2 The process shown illustrates the principle of welding thin-plate CFRTP components, such as... Figure 3 As shown, under the combined action of mechanical pressure and high-frequency vibration perpendicular to the target welding interface, the areas in contact between the lower surface 211 of the thin plate CFRTP component 21 and the upper surface 221 of the thin plate CFRTP component 22 undergo intense mutual friction and viscoelastic loss to generate heat, causing the temperature of the contact area to rise rapidly. The thermoplastic resin matrix partially melts, and then, under the pressure, they penetrate, diffuse, and entangle with each other, forming a strong bonded area after cooling.

[0026] As can be seen, using Figure 1 , Figure 2 The process shown applies only when the thickness of the thin-plate CFRTP component 21 along the vibration direction is... When the component is relatively thin, the vibration of the ultrasonic welding head 1 can be efficiently transmitted to the area to be welded. If the component is thicker in the vibration direction, for example, exceeding 6 mm, the amplitude needs to be significantly increased or the welding time extended to compensate for transmission loss. However, due to the thermoplastic nature of CFRTP material, the surface of the workpiece at the contact point with the ultrasonic welding head is prone to melting or crushing due to excessive vibration. Under the limitations of the above factors, CFRTP components welded using ultrasonic welding technology generally need to meet near-field welding conditions, that is, the thickness in the direction perpendicular to the welding interface is often limited to less than 6 mm.

[0027] However, with the expanding applications of CFRTP materials in aerospace, new energy vehicles, and other fields, the demand for reliable connections of various large, non-thin plate components is becoming increasingly urgent. For example, Figure 4 Parts (A) and (B) show two solid cuboid CFRTP components, namely CFRTP component 31 and CFRTP component 32, from different perspectives. These two components need to be reliably connected to form a larger component. The target welding end face 311 of CFRTP component 31 and the target welding end face 321 of CFRTP component 32 have mutually fitting rectangular profiles (mirror symmetry), and the thickness of CFRTP component 31 along the direction perpendicular to the target welding end face 311 is... The thickness of CFRTP component 32 in the direction perpendicular to the target welding end face 322 The diameters have all exceeded 6mm (such as 20mm, 30mm or even larger), therefore, the existing ultrasonic welding process that transmits vibration energy vertically can no longer be used.

[0028] For example, Figure 5 Parts (A) and (B) show two additional, thicker CFRTP components, namely CFRTP component 33 and CFRTP component 34, from different perspectives. Both components are hollow cavity-shaped components with annular target welding end faces. The contours of the target welding end faces 331 of CFRTP component 33 and 341 of CFRTP component 34 are mutually matched (mirror symmetrical). Meanwhile, the thickness of CFRTP component 33 along the direction perpendicular to the target welding end face 331... The thickness of CFRTP component 34 along the direction perpendicular to the target welding end face 324 All have exceeded 6mm, if like Figure 6As shown, the existing process of vertically transmitting vibration to the welding interface is used to perform ultrasonic welding on these two CFRTP components. The vibration transmission path is extremely long, the energy attenuation is extremely large, and the entire vibration heat generation area will run through the entire CFRTP component 33, which will inevitably have an adverse effect on the stability of the thermoplastic resin-carbon fiber composite structure inside the component. Therefore, the existing ultrasonic welding process of vertically transmitting vibration energy cannot achieve reliable welding of non-thin plate CFRTP components.

[0029] Understandable, Figures 4 to 6 The embodiments shown are only used to illustrate the limitations of existing ultrasonic welding processes on the vertical thickness of CFRTP components at the welding interface, and do not constitute a constraint on the shape of CFRTP components to which the method of this application is intended. Any CFRTP component with a closed or unclosed target welding end face and a relatively thick thickness along the direction perpendicular to the target welding end face can be reliably connected using the side ultrasonic welding method provided in this application.

[0030] <Methodological Framework of this Application> In order to achieve ultrasonic welding Figure 4 , Figure 5 To achieve the goal of high-quality welding of non-thin plate CFRTP components, this application provides a side ultrasonic welding method for CFRTP components through embodiments, which is used to weld the mutually compatible target welding end faces of two CFRTP components.

[0031] Figure 7 The figure shows a schematic diagram of the implementation of the method in some embodiments. As shown, the method includes three sequentially performed operations: positioning and pressurizing operation, side ultrasonic welding operation, and post-processing operation.

[0032] Specifically, The positioning and pressurizing operation includes: aligning the target welding end faces of two CFRTP components and pressing a welding plate made of CFRTP material against the target welding end faces, wherein the area of ​​the main surface of the welding plate is larger than the area of ​​the target welding end face, and after pressing, the projection area of ​​the target welding end face on the main surface is located inside the main surface. The side ultrasonic welding operation includes: while the welding plate is being pressed, the ultrasonic welding head moves in the vibration transmission area and applies vertical high-frequency vibration to the vibration transmission area, wherein the vibration transmission area is the area on the main surface located outside the projection area; Post-processing operations include removing the portion corresponding to the vibration transmission area from the welded component.

[0033] The side-mounted ultrasonic welding method for CFRTP components provided in this application addresses the inherent drawback of excessive energy loss and difficulty in improving welding results when using existing vertical vibration transmission methods for ultrasonic welding of thick, non-thin CFRTP components, due to the viscoelastic properties of the CFRTP material. This method utilizes a separately added plate of the same material to construct the vibration transmission area, and uses side-mounted ultrasonic vibration to change the vibration energy transmission from vertical to the interface direction to the target welding area, thereby significantly reducing vibration energy loss and avoiding potential damage to the component body caused by increasing the amplitude or vibration application time.

[0034] The specific implementation of each of the above steps will be described in detail below with reference to the accompanying drawings and embodiments.

[0035] <Example 1> This embodiment adopts Figure 7 The method shown is used to weld the mutually compatible target welding end faces of the cuboid CFRTP component 31 and CFRTP component 32. Figure 8 , Figure 9 , Figure 10 The diagrams show the process flow of the welding operation, including the positioning and pressurization operation, the side ultrasonic welding operation, and the post-processing operation.

[0036] like Figure 8 As shown in part (A), during the positioning and pressurizing operation phase, positioning clamping devices commonly used in the art, such as positioning jigs and robotic arms, can be used to adjust the orientation of CFRTP component 31 and CFRTP component 32 so that the target welding end face 311 of CFRTP component 31 and the target welding end face 321 of CFRTP component 32 are positioned face to face. Then, the welding plate 41 is placed between the target welding end face 311 and the target welding end face 321. The position of the positioning jig is then adjusted to align the two target welding end faces. Then, as shown in part (A), the positioning and pressurizing operation phase can be performed. Figure 8 As shown in part (B), pressure is applied in opposite directions in a direction perpendicular to the target welding end face, thereby pressing the welding plate 41 placed between the two target end faces.

[0037] The welding plate 41 is also made of CFRTP material. The area of ​​its main surface (including the main surface 411 facing the target welding end face 311 and the main surface 412 facing the target welding end face 321) is larger than the area of ​​the target welding end faces 311 and 321. The distance between the two main surfaces (i.e. the thickness of the welding plate 41) is preferably 2 mm to 5 mm. Using this thickness range to manufacture the welding plate can provide sufficient strength and can also efficiently propagate high-frequency mechanical vibration along the direction of the main surface.

[0038] also, Figure 8Part (C) shows a top view of the two CFRTP components and the welding plate after compression. As shown, after the welding plate 41 is compressed by the two CFRTP components, the projection areas of the two target welding end faces 311 and 321 on the main surfaces 411 and 412 of the welding plate 41 are all located inside the main surfaces. Therefore, two areas will be formed on the main surface of the welding plate 41. One is the projection area 413, which is the part on the main surface that is in close contact with the target welding end faces. The other area 414 is the area on the main surface of the welding plate 41 that is outside the projection area 413. In the side ultrasonic welding operation described later, this area is used to withstand the vertical high-frequency vibration of the ultrasonic welding head 1 and transmit the vertical high-frequency vibration to the projection area 413 in a direction parallel to the main surface. Therefore, in this application, this area is referred to as the vibration transmission area 414.

[0039] After completing the positioning and pressurization operation, the side ultrasonic welding operation can be performed. Figure 9 Part (A) shows the movement of the ultrasonic welding head 1 in the vibration transmission area 414 during the side ultrasonic welding operation, and Part (B) is a cross-sectional view of the CFRTP component and the welding plate during the side ultrasonic welding process.

[0040] like Figure 9 As shown, during the side-mounted ultrasonic welding operation, CFRTP components 31 and 32 are continuously subjected to opposing pressure, causing the projected area 413 of the welding plate 41 to be continuously compressed. Specifically, from the time the welding plate 41 is compressed until welding is completed (during the continuous high-frequency vibration of the ultrasonic welding head 1 and the cooling phase after vibration), the projected area 413 of the welding plate 41 is always subjected to a preset compressive force, preferably ranging from 15 psi to 30 psi (pounds per square inch). During this period, the ultrasonic welding head moves within the vibration transmission area 414 and applies vertical high-frequency vibration to the vibration transmission area 414, preferably at a frequency of 20 kHz to 40 kHz.

[0041] The vertical vibration is transmitted along the main surface from the vibration transmission area 414 to the projection area 413. Since the part of the main surface in the projection area 413 is pressed by the target welding end face 311 of the CFRTP component 31 and the target welding end face 321 of the CFRTP component 32, the four planes that are in close contact in pairs are driven to perform high-frequency vertical motion. Obviously, this high-frequency vertical motion will cause local melting of the thermoplastic resin matrix. Under the continuous pressure, the part of the main surface 411 in the projection area 413 and the target welding end face 311, as well as the part of the main surface 412 in the projection area 413 and the target welding end face 321, all undergo mutual penetration, diffusion and entanglement. Finally, under the continuous pressure, they gradually cool down, thereby completing the side ultrasonic welding operation.

[0042] Understandably, during the side-mounted ultrasonic welding operation, ultrasonic welding head 1 can be used as follows: Figure 1 The spot welding method shown applies high-frequency vibration to the welding plate 41 point by point in the vibration transfer area 414, and after welding at each point, it is lifted and moved to the next point, and then lowered to weld the new point; it can also be done as follows: Figure 2 As shown, in the continuous welding method, the ultrasonic welding head 1 continuously applies high-frequency vertical vibration to the vibration transfer area 414 while continuously moving along the high-frequency vibration area.

[0043] Figure 10 Part (A) shows the state of the CFRTP component and the welding plate 41 after the side ultrasonic welding operation is completed. After the ultrasonic welding head 1 completes the side ultrasonic welding and applies pressure and cooling, the target welding end face 311 of the CFRTP component 31 and the target welding end face 321 of the CFRTP component 32 are firmly connected to the projection area of ​​the welding plate 41, forming a fixed connection area 51. At this time, post-processing operations can be performed. By cutting, grinding, etc., the part corresponding to the vibration transfer area 414 in the welding plate 41 is removed, leaving only the part that has formed the fixed connection area 51, finally obtaining the following... Figure 10 The welded integral CFRTP component shown in section (B).

[0044] pass Figure 8 , Figure 9 As can be seen, the method provided in this application, by providing a separate welding plate for transmitting vibration along the interface, can directly transmit high-frequency vibration from the outside of the component to the target welding interface along the interface direction. The high-frequency vibration energy is not transmitted inside the CFRTP component body before reaching the target welding interface, which greatly reduces the ineffective consumption of vibration energy. In addition, since the vibration influence area is controlled near the target welding interface, potential damage to the internal structure of the component can be effectively avoided.

[0045] <Example 2> This embodiment adopts Figure 7 The method shown involves side-mounted ultrasonic welding of cuboid CFRTP components 31 and 32. Figure 11 A schematic diagram of the operation during the side-mounted ultrasonic welding stage in this embodiment is shown, wherein part (A) illustrates the movement of the ultrasonic welding head 1, and part (B) shows a cross-sectional view of the CFRTP component and the welding plate 41. Figure 11 As shown, the difference between this embodiment and embodiment 1 is that during the application of vertical high-frequency vibration to the vibration transmission area 414 by the ultrasonic welding head 1, an additional support plate 61 is provided to support the vibration transmission area 414. This is to avoid the problem that when the ultrasonic welding head 1 applies high-frequency vibration to the unsupported vibration transmission area 414, the vibration amplitude of the edge portion of the vibration transmission area 414 is amplified without constraint, resulting in energy being mainly consumed in the vibration of the edge.

[0046] The supporting plate is preferably made of metal or alloy materials such as stainless steel, aluminum alloy, or copper. Figure 11 As shown, the support plate 61 is fixedly disposed on the side of the welding plate 41 facing away from the ultrasonic welding head 1, that is, on the side of the main surface 412, and the contact part between the support plate 61 and the welding plate 41 is located at the edge of the welding plate 41. Furthermore, the support part does not coincide with the projection position of the ultrasonic welding head 1 on the welding plate 41, so as to avoid the problem of the energy of vibration transmitted along the interface being wasted by directly bearing the vertical high-frequency vibration while providing support for the welding plate 41.

[0047] <Example 3> This embodiment adopts Figure 7 The method shown involves side ultrasonic welding of the cuboid CFRTP components 31 and 32. Similar to Embodiment 2, this embodiment also includes a supporting plate 61. Figure 12 The diagram shows the cooperation of the welding plate 41 and the support plate 61 during the positioning and pressurizing operation stage and the side ultrasonic welding stage, wherein part (A) is the cooperation diagram during the positioning and pressurizing operation stage and part (B) is the cooperation diagram during the side ultrasonic welding operation stage.

[0048] See Figure 12In this embodiment, after the welding plate 41 is pressed down, the support plate 61 does not directly contact the vibration transfer area 414 before the start of the side ultrasonic welding operation. Instead, it has a small gap Δh, such as no more than 0.2mm. At this time, the support plate 61 does not apply additional force to the welding plate. During the side ultrasonic welding operation, the vibration transfer area 414 vibrates under the drive of the vertical high-frequency vibration loaded by the ultrasonic welding head 1. When its edge contacts the support plate 61, it can be limited and supported by the support plate. When it moves in the opposite direction, it will detach from the support plate 61. In this way, it can provide support and avoid the problem of excessive absorption of vibration energy when the support plate 61 is always in contact with the vibration transfer area 414. At the same time, it can also reduce the probability of the edge of the welding plate 41 vibrating at high frequency and sticking to the support plate 61.

[0049] <Example 4> This embodiment adopts Figure 7 The method shown involves side-mounted ultrasonic welding of the cavity-shaped CFRTP components 33 and 34. Figure 13 , Figure 14 The diagrams show the state of the positioning and pressurization operation and the side ultrasonic welding stage, respectively.

[0050] like Figure 13 As shown, in this embodiment, the welding plate 42 is an annular plate made of CFRTP material. The shape of its inner annular contour is consistent with the inner contour shape of the target welding end face 331 of CFRTP component 33 and the target welding end face 341 of CFRTP component 34. Its outer contour is larger than the outer contour of the target welding end faces of CFRTP component 33 and CFRTP component 34. During positioning and clamping, firstly as shown... Figure 13 As shown in part (A), the two main surfaces (main surface 421 and main surface 422) of the welding plate 42 are aligned with the target welding end face 331 of the CFRTP component 33 and the target welding end face 341 of the CFRTP component 34, respectively. That is, the inner contour of the welding plate 42 is aligned with the inner contour of the target welding end face 331 and the target welding end face 341, and then pressed together by the two target welding end faces to form Figure 13 The annular projection area 423 (which is still located inside the main surface of the welding plate 42) that coincides with the target welding end face is shown in the perspective view of part (B) or the top perspective view of part (C), and the vibration transmission area 424 outside the projection area 423.

[0051] Figure 14 Part (A) shows a schematic diagram of the side ultrasonic welding process with the support plate 62 provided. Figure 14(B) shows a cross-section of the CFRTP component, welding plate 42, and support plate 62, as shown below. Figure 14 As shown, the support plate 62 is also annular, with its inner contour smaller than that of the welding plate 42 and larger than that of the target welding end face, and it does not coincide with the area of ​​vertical vibration of the ultrasonic welding head 1. Its outer contour is larger than that of the welding plate 42.

[0052] Figure 15 A schematic diagram of the complete component obtained after the post-processing operation is shown. As shown, the target welding end faces of CFRTP component 33 and CFRTP component 34 are firmly connected through the bonding area 52.

[0053] <Example 5> This embodiment adopts Figure 7 The method shown performs side ultrasonic welding on cuboid CFRTP components 31 and 32. The difference between this embodiment and Embodiment 2 or Embodiment 3 is that the side ultrasonic welding operation consists of two stages. After completing the first stage of side ultrasonic welding, as... Figure 16 As shown, the two CFRTP components (CFRTP component 31 and CFRTP component 32) are flipped over and re-pressed. Since the fixed area has been formed, CFRTP component 31, welding plate 41 and CFRTP component 32 are fixed together. Therefore, the second stage of side ultrasonic welding can be carried out without positioning.

[0054] observe Figure 9 It is known that when the ultrasonic welding head 1 applies vertical high-frequency vibration to one main surface of the welding plate 41, the vibration excitation state of the target welding end face located on the opposite side is not the same as that of the target welding end face located on the same side. Therefore, in this embodiment, by first applying high-frequency vibration to one main surface 411 of the welding plate 41, then flipping the CFRTP component, and then applying high-frequency vibration to the other main surface 412 of the welding plate 41, the projection area 413 of the welding plate 41 can be kept as consistent as possible with the fixed connection state of the two target welding interfaces.

[0055] <Example 6> This embodiment adopts Figure 7The method shown performs side ultrasonic welding on non-flat cylindrical CFRTP components 35 and 36. The difference between this embodiment and the previous embodiments is that, before the positioning and pressurization operation, a number of energy-conducting ribs 7 are arranged in the target welding end face 361 of the CFRTP component 36 and the projection area 433 of the circular welding plate (the area of ​​the circular welding plate other than the projection area 433 is the vibration transmission area 434). The energy-conducting ribs 7 are made of CFRTP material and can adopt conventional energy-conducting structures such as tetrahedral cones (pyramids) to achieve local concentration and directional transmission of vibration energy, significantly improving the bonding strength of the target welding area.

[0056] Considering that vertical vibration propagates from the outer contour of the target weld interface inwards, and that the vibration gradually attenuates during propagation, therefore, preferably, as follows: Figure 17 As shown, the density of the energy-conducting ribs 7 gradually decreases from the center of the target welding end face outwards, thereby achieving a balanced distribution of bonding strength as much as possible.

[0057] The specific embodiments of this application have been described in detail above. For those skilled in the art, several improvements and modifications can be made to this application without departing from the principle of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A side ultrasonic welding method for CFRTP components, used for welding mutually compatible target welding end faces of two CFRTP components, characterized in that, include: The positioning and pressurizing operation aligns the target welding end faces of two CFRTP components and presses them together with a welding plate made of CFRTP material. The area of ​​the main surface of the welding plate is larger than the area of ​​the target welding end face, and after pressing, the projection area of ​​the target welding end face on the main surface is located inside the main surface. In a side-mounted ultrasonic welding operation, while the welding plate is being pressed, the ultrasonic welding head moves in the vibration transmission area and applies vertical high-frequency vibration to the vibration transmission area, wherein the vibration transmission area is the area on the main surface located outside the projection area. The post-processing operation involves removing the portion corresponding to the vibration transmission area from the welded component.

2. The side ultrasonic welding method for CFRTP components according to claim 1, characterized in that, The thickness of the CFRTP component along the direction perpendicular to the target welding interface is greater than 6 mm.

3. The side ultrasonic welding method for CFRTP components according to claim 1, characterized in that, After the welding plate is pressed down until the welding is completed, the projected area is always subjected to a preset pressing force, the pressure range of which is 15psi-30psi.

4. The side ultrasonic welding method for CFRTP components according to claim 1, characterized in that, The frequency range of the vertical high-frequency vibration of the ultrasonic welding head is 20kHz to 40kHz. The thickness of the welding plate is 2mm to 5mm.

5. The side ultrasonic welding method for CFRTP components according to claim 1, characterized in that, The CFRTP component has an annular target welding end face; The welding plate is an annular plate, and its inner contour shape is consistent with the inner contour shape of the target welding end face. The positioning and pressurizing operation also includes aligning the inner contour of the welding plate with the inner contour of the target welding end face.

6. The side ultrasonic welding method for CFRTP components according to claim 1, characterized in that, Also includes: During the application of vertical high-frequency vibration to the vibration transmission area by the ultrasonic welding head, the edge of the vibration transmission area is supported by a support plate, and the support location does not coincide with the projection position of the ultrasonic welding head on the welding plate.

7. The side ultrasonic welding method for CFRTP components according to claim 6, characterized in that, The supporting plate does not directly contact the vibration transfer area before the ultrasonic welding head begins to vibrate vertically at high frequency.

8. The side ultrasonic welding method for CFRTP components according to claim 1, characterized in that, The side ultrasonic welding operation consists of two stages. After the first stage of side ultrasonic welding is completed, the two CFRTP components are flipped over and re-pressed, and then the second stage of side ultrasonic welding is performed.

9. The side ultrasonic welding method for CFRTP components according to claim 1, characterized in that, Also includes: A number of energy-conducting ribs are arranged on the target welding end face and the projected area, and the arrangement density of the energy-conducting ribs gradually decreases from the center of the target welding end face outward.

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