A same-station laser shock edge bonding method and device

Abstract

The application provides a same-station laser shock edge covering connection method and device, and relates to the technical field of plate edge covering. The method comprises the following steps: reciprocating scanning of a continuous wave laser along the folding line of an outer plate, under the action of a laser-induced thermal stress, the outer plate is bent along the folding line, and the scanning is stopped when a set bending angle is reached, thereby completing pre-folding of the outer plate; placing an inner plate on the pre-folded outer plate, so that the edge of the inner plate coincides with the folding line of the outer plate, and using a high-energy, short-pulse laser beam to step along the parallel lines of the folding line of the outer plate, the outer plate is subjected to high-strain-rate bending deformation, and is in close contact with the inner plate, and under the action of high-speed impact, laser shock welding is generated between the outer plate and the inner plate, thereby completing the edge covering connection. The application does not require a specific bending machine and a die, the process is simple and flexible, is suitable for edge covering connection of materials with poor ductility, edge covering connection of plates with a thin inner plate or a thin outer plate, and can realize precise connection of sub-millimeter plates, thereby guaranteeing the quality and consistency of the connected parts.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of plate edge covering, and particularly relates to a same-station laser impact edge covering connection method and device. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] Plate edge covering connection is a commonly used metal plate connection method, which wraps the edges of two layers of plates together to form a connection, providing a certain degree of connection strength, edge strength, protection and sealing performance, and the connection piece has no sharp and sharp edges, and the appearance is smooth, flat and beautiful, and is widely used in the metal processing industry.

[0004] The traditional plate edge covering connection relies on edge folding tools (such as bending machines and bending dies) to realize pre-folding of the outer plate (referred to as outer plate), and further bending under the action of rollers or dies, and forming a superposition area with the inner plate (referred to as inner plate) to complete the edge covering operation. However, the traditional plate edge covering connection has some disadvantages: first, different edge covering connections require the use of different bending machines and dies, which limits the flexibility and applicability of the process; second, when the outer plate is thin, its strength or stiffness in the edge folding area is not enough to effectively clamp the inner plate, resulting in insufficient edge covering connection strength; in addition, when the inner plate is thin, the rebound of the outer plate after bending is easy to cause poor adhesion with the inner plate, thereby affecting the firmness of the connection; furthermore, since the outer plate is folded, for materials with poor ductility at room temperature, cracks are easily generated in the bending forming process, and even breakage occurs, thereby causing the edge covering connection to be unable to be completed. SUMMARY

[0005] To overcome the above-mentioned deficiencies of the prior art, the present application provides a same-station laser impact edge covering connection method and device, which does not require special bending machines and dies, has simple process and high flexibility, is suitable for edge covering connection of materials with poor ductility, edge covering connection of plates with thin inner plate or thin outer plate, and can realize precise connection of sub-millimeter plates, ensuring the quality and consistency of the connection piece.

[0006] To achieve the above-mentioned purpose, one or more embodiments of the present application provide the following technical solutions:

[0007] The first aspect of the present application provides a same-station laser impact edge covering connection method.

[0008] A same-station laser impact edge covering connection method, comprising the following steps:

[0009] The fixed outer plate is reciprocally scanned along the folding line of the outer plate by a continuous wave laser, and under the action of the laser-induced thermal stress, the outer plate is bent along the folding line, and the scanning is stopped when the set bending angle alpha is reached, and the pre-folding of the outer plate is completed;

[0010] The inner plate is placed on the pre-folded outer plate, the edge of the inner plate is overlapped with the folding line of the outer plate, and a high-energy, short-pulse laser beam is used to step impact along the parallel line of the outer plate folding line, the outer plate further occurs high strain rate bending deformation, and under the action of high-speed impact, laser impact welding is generated with the inner plate, and the edge covering connection is completed.

[0011] Optionally, a through hole is also pre-opened on the inner plate and / or the outer plate, under the action of the laser shock wave, the material flows into the through hole to form an interlocking structure with a small opening and a large bottom, and the riveting of the overlapping area of the inner plate and the outer plate is performed.

[0012] Optionally, the through hole opened on the inner plate and / or the outer plate is a tapered hole.

[0013] Optionally, it also includes pre-gluing on the surface of the outer plate and / or the outer plate, and the gluing of the overlapping area of the inner plate and the outer plate is performed.

[0014] Optionally, black paint or graphite is coated as an absorption layer on the surface of the outer plate irradiated by the pulsed laser, or aluminum foil or adhesive tape is pasted on the surface of the outer plate irradiated by the pulsed laser.

[0015] Optionally, the set bending angle alpha is less than or equal to 60 degrees.

[0016] Optionally, the power of the continuous wave laser is greater than 50W; the power density of the pulsed laser is greater than 1GW / cm 2 , and the pulse width is less than 20ns.

[0017] Optionally, the continuous wave laser can also use a long-pulse laser.

[0018] Optionally, the high-energy, short-pulse laser beam is always located in the normal direction of the outer plate to be impacted area.

[0019] Optionally, the material of the inner plate and the outer plate is the same or different metal of copper, aluminum, steel and titanium, and the inner plate can also be plastic, glass and ceramic.

[0020] The second aspect of the application provides a same-station laser impact edge covering connecting device.

[0021] The device applied to the same-position laser impact edge covering connection method comprises a workbench and a laser system, a bottom plate is arranged on the workbench, the bottom plate is used for bearing an outer plate and an inner plate, clamping tools are arranged on the bottom plate and used for clamping the outer plate and the inner plate, and the laser system is used for providing continuous wave laser and high-energy short pulse laser beams to perform edge covering connection on the outer plate and the inner plate.

[0022] The above one or more technical solutions have the following beneficial effects:

[0023] 1. The same-position laser impact edge covering connection method and device provided by the application do not need special bending machines and molds, the process is simple and flexible, and different edge covering connections can be flexibly adapted by adjusting laser parameters.

[0024] 2. The application is suitable for edge covering connection of materials with poor ductility. Firstly, the outer plate generates thermal stress under the action of continuous wave laser, and the thermal stress causes the outer plate to generate bending deformation, that is, the outer plate is first pre-bent by an angle α. Then, the outer plate further generates high strain rate bending deformation under the action of the explosion plasma impact force caused by the pulse laser. The first bending deformation (i.e., the pre-bending) belongs to thermal deformation, and the second bending deformation (i.e., the impact deformation) belongs to cold deformation. Compared with the way of completely bending through cold deformation on a bending machine, the material is less likely to break. Therefore, the edge covering connection can also be performed on the outer plate with poor ductility.

[0025] 3. Under the action of the pulse laser, the high-speed impact of the outer plate on the inner plate can cause the plate to bend and further cause metallurgical welding, thereby improving the edge covering connection strength. Therefore, when the outer plate is thin, effective edge covering connection can also be formed, and the problem of low connection strength caused by the insufficient bending clamping force of the inner plate due to the thin outer plate in the traditional method is overcome.

[0026] 4. The overlapping area can be further riveted by using the laser beam to obtain higher connection strength. The riveting process is simple and does not require additional rivets. At the same time, the problem of poor fit between the inner plate and the outer plate caused by the rebound of the outer plate after bending when the inner plate is thin is further effectively solved, and the fatigue failure resistance of the edge covering connection part under dynamic load can be significantly improved.

[0027] 5. The laser beam has extremely high precision and controllability, can realize accurate connection of plate materials at the sub-millimeter level, and ensure the quality and consistency of the connection part.

[0028] 6. The edge covering connection method belongs to a non-contact type, which avoids the direct contact between the punch or roller and the plate in the traditional method, thereby avoiding the wear and tear caused by physical contact.

[0029] Advantages of the present application's additional aspects will become apparent in the description that follows. These and other advantages can be learned from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings, which form a part of the specification, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification. The illustrations are shown solely for the purpose of illustrating the illustrative embodiments of the application and are not intended to limit the present application in any way.

[0031] Figure 1 is a process schematic diagram of a laser shock hemming connection method of an embodiment of the present application.

[0032] Figure 2 is a cross-sectional schematic diagram of a laser shock hemming connection piece of an embodiment of the present application that has not been riveted.

[0033] Figure 3 is a three-dimensional schematic diagram of a laser shock hemming connection piece of an embodiment of the present application that has not been riveted.

[0034] Figure 4 is a cross-sectional schematic diagram of a laser shock hemming connection piece of an embodiment of the present application in which the inner plate has a conical hole and is riveted.

[0035] Figure 5 is a three-dimensional schematic diagram of a laser shock hemming connection piece of an embodiment of the present application in which the inner plate has a conical hole and is riveted.

[0036] Figure 6 is a cross-sectional schematic diagram of a laser shock hemming connection piece of an embodiment of the present application in which the outer plate has a conical hole and is riveted.

[0037] Figure 7 is a three-dimensional schematic diagram of a laser shock hemming connection piece of an embodiment of the present application in which the outer plate has a conical hole and is riveted.

[0038] Figure 8 is a schematic diagram of a device of an embodiment of the present application.

[0039] Wherein, 1, laser; 2, clamping tool; 3, inner plate; 4, outer plate; 5, bottom plate; 6, workbench. DETAILED DESCRIPTION

[0040] It should be noted that the following detailed description is merely exemplary and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0041] It is to be understood that the terminology used herein is for the purpose of describing the particular embodiments only and is not intended to be limiting of the example embodiments according to the present application.

[0042] In the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0043] The overall idea of the present application is as follows:

[0044] The present application provides a same-station laser impact edge covering connection method and device, wherein the same-station laser impact edge covering connection method is performed by using the same-station laser impact edge covering connection device, and specifically includes the following steps:

[0045] The outer plate 4 is placed on the bottom plate 5 and fixed on the workbench 6 by the clamping tool 2;

[0046] The position of the workbench 6 is adjusted so that the center of the laser spot is located at the starting point of the folding edge line of the outer plate 4, the parameters of the YAG laser 1 are selected and set as needed, the laser beam is emitted in the continuous wave mode, and the workbench 6 and the laser beam are moved relative to each other, so that the laser beam reciprocally scans along the folding edge line of the plate, and the outer plate 4 generates thermal stress in the scanning area, which causes the outer plate 4 to gradually form a bending deformation with an angle α, thereby completing the pre-folding process of the outer plate 4;

[0047] The inner plate 3 is placed on the outer plate 4 after pre-folding, the edge of the inner plate 3 is overlapped with the folding edge line of the outer plate 4, and the inner plate 3 is fixed on the workbench 6 by the clamping tool 2, the position of the workbench 6 is adjusted and the output type of the laser 1 is converted, so that the high-energy, short-pulse laser beam steps along the parallel lines of the folding edge line of the outer plate 4, the outer plate 4 further generates high-strain-rate bending deformation, and is close to the inner plate 3 at the same time, and under the action of high-speed impact, laser impact welding is generated with the inner plate 3;

[0048] If it is necessary to continue to rivet and lock the overlapping area, a tapered hole is pre-formed on the inner plate 3 and / or the outer plate 4, under the action of the laser impact wave, the material flows into the tapered hole to form an interlocking structure with a small opening and a large bottom, and riveting is completed.

[0049] Embodiment one

[0050] The present embodiment discloses a same-station laser impact edge covering connection method.

[0051] As shown in Figure 1 A same-station laser impact edge covering connection method includes the following steps:

[0052] The outer plate 4 is fixed, and a continuous wave laser reciprocally scans along the folding edge line of the outer plate 4, under the action of the thermal stress induced by the laser, the outer plate 4 is bent along the folding edge line, and when the set bending angle α is reached, the scanning is stopped, and the pre-folding of the outer plate 4 is completed;

[0053] The inner plate 3 is placed on the pre-folded outer plate 4, so that the edge of the inner plate 3 coincides with the fold line of the outer plate 4. A high-energy, short-pulse laser beam is used to perform a step-by-step impact along the parallel line of the fold line of the outer plate 4. The outer plate 4 further undergoes high strain rate bending deformation and, while approaching the inner plate 3, laser shock welding is performed with the inner plate 3 under the action of high-speed impact, thus completing the edge-wrapping connection.

[0054] In this embodiment, the outer plate 4 is placed on top of the base plate 5, with the base plate 5 and the outer plate 4 overlapping each other. The outer plate 4 is then fixed to the worktable 6 using a clamping tool 2. Figure 1 As shown in (a), laser 1 is adjusted to output a continuous wave laser beam, and the laser beam is made to reciprocate along the fold line of the outer plate 4. Under the action of laser-induced thermal stress, as shown in (a), laser 1 is adjusted to output a continuous wave laser beam, and the laser beam is made to reciprocate along the fold line of the outer plate 4. Figure 1 As shown in (b), the outer plate 4 is bent along the fold line. With continuous reciprocating scanning, the bending angle α of the outer plate 4 gradually decreases, as... Figure 1 As shown in (c), when the bending angle reaches α, the pre-folding process of the outer panel 4 is completed.

[0055] like Figure 1 As shown in (c), the bending angle α is defined as the angle between the side of the outer plate that bends under the laser-induced thermal stress and the side of the outer plate that does not bend.

[0056] Understandably, the inner panel 3 and outer panel 4 must be cleaned before connection.

[0057] Place the inner plate 3 on the pre-folded outer plate 4, ensuring the edge of the inner plate 3 aligns with the fold line of the outer plate 4. Use clamping tool 2 to secure the inner plate 3 and outer plate 4 together to the worktable 6. Adjust the laser 1 to output a high-energy, short-pulse laser beam, and adjust the position of the worktable 6 as follows: Figure 1 As shown in (d), the pulsed laser beam completes the step-by-step impact of the pre-folded area of ​​the outer plate 4 along a line parallel to the folding line.

[0058] Pulsed laser-induced explosive plasma generates impact force. Under the impact force of the pulsed laser-induced explosive plasma, the outer plate 4 undergoes high strain rate plastic bending deformation along the fold line. Simultaneously, as it approaches the inner plate 3, the pre-folded area of ​​the outer plate 4 impacts the upper surface of the inner plate 3 at extremely high speed. Under the combined action of instantaneous and intense deformation, high-speed interfacial shear, and compressive stress, atomic diffusion occurs between the outer plate 4 and the inner plate 3. Under the action of high-speed impact, laser shock welding occurs between the outer plate 4 and the inner plate 3, achieving the welding of the outer plate 4 and the inner plate 3, ultimately forming the edge-sealing connector. Figure 2 , Figure 3 The diagram shown is a final completed laser shock edging connection at the same workstation in this embodiment. The outer plate 4 and the inner plate 3 are tightly fitted together, completing the laser shock edging connection that produces a metallurgical weld.

[0059] The laminated area can also be glued or riveted to increase the connection strength. Gluing requires pre-gluing on the surface of the plate, and riveting requires pre-opening one or more through holes, preferably tapered holes, in the inner plate 3 and / or the outer plate 4. Under the action of laser shock waves, the material flows into the tapered hole to obtain one or more interlocking structures with a small opening and a large bottom, thereby achieving riveting locking of the laminated area.

[0060] As shown in Figures 4-7 , it is a schematic diagram of riveting locking after the same-site laser shock edge covering connection of the embodiment. The pre-opening holes are located on the inner plate 3 and the outer plate 4 respectively. Under the action of laser shock waves, the upper part of the material flows into the cavity of the pre-opening hole and plastically deforms downward. When the bottom is constrained, it continues to plastically deform laterally, and finally forms an interlocking structure with a small opening and a large bottom, completing the riveting locking of the inner plate 3 and the outer plate 4.

[0061] As shown in Figure 4 , Figure 5 , it is a schematic diagram of laser shock edge covering connection for riveting with tapered holes in the inner plate 3; as shown in Figure 6 , Figure 7 , it is a schematic diagram of laser shock edge covering connection for riveting with tapered holes in the outer plate 4.

[0062] When further riveting locking, the required pre-opening holes can be located on the outer plate 4 or the inner plate 3, or simultaneously located at different positions of both.

[0063] Further, by adjusting the size and number of pre-opening holes, riveting locking of the inner plate 3 and the outer plate 4 with different strengths can be achieved, and then edge covering connection with different strengths can be obtained. The size of the pre-opening hole needs to be determined according to the thickness of the plate and the actual connection requirements.

[0064] Further, the inner plate 3 and the outer plate 4 can be homogenous or heterogeneous metals such as copper, aluminum, steel, titanium, etc., and the inner plate 3 can also be plastic, glass, ceramic, etc.

[0065] Further, to ensure the effect of edge covering connection, the outer plate 4 is usually a metal plate with good toughness.

[0066] Further, the surface of the outer plate 4 irradiated by pulsed laser can be coated with black paint or graphite as an absorption layer, or aluminum foil or adhesive tape can be pasted, or the surface of the plate can be directly used as an absorption layer.

[0067] The bending angle α should be less than or equal to 60 degrees.

[0068] The laser 1 is preferably a YAG laser 1. The laser beam output by the YAG laser 11 is always located in the normal direction of the plate irradiation area.

[0069] The power of the continuous wave laser should be greater than 50W; the YAG laser 1 realizes the switching from continuous wave mode to pulse mode through Q-switching and mode-locking technology, obtains short pulse or ultrashort pulse laser, and the laser beam is always located in the normal direction of the area to be impacted of the outer plate 4, and the power density of the pulse laser should be greater than 1GW / cm 2 , and the pulse width should be less than 20ns, and the specific value depends on the actual situation.

[0070] In this embodiment, by adjusting the laser energy, spot size, spot overlap rate and step speed, the edge covering connecting piece of different materials, different thicknesses and different requirements can be realized. The step speed and step distance of the workbench 6 depend on the laser spot size, the type of the plate and the size of the plate.

[0071] Further, the step process involves the overlap rate of the laser spot, which needs to be determined according to the actual situation. In order to ensure the forming effect, the overlap rate of the laser spot should be greater than 40%.

[0072] At this point, the laser impact edge covering connection of the plate is completed, and the edge covering connection with or without riveting locking, metallurgical welding and tight fitting of the overlapping area is obtained.

[0073] Embodiment two

[0074] This embodiment discloses a laser impact edge covering connection device, which comprises:

[0075] A laser system, which comprises a laser 1 for generating continuous and pulse laser;

[0076] A clamping tool 2 for pressing the plate;

[0077] An outer plate 4 and an inner plate 3 for mutual connection;

[0078] A bottom plate 5 for providing bottom support;

[0079] A workbench 6 for adjusting the irradiation position of the laser beam, cooperating with the laser 1 to realize multi-path and multi-angle laser scanning.

[0080] Those skilled in the art should understand that the above-mentioned modules or steps of the present application can be realized by a general computer device, alternatively, they can be realized by program codes executable by a computing device, so that they can be stored in a storage device and executed by a computing device, or they can be respectively manufactured into integrated circuit modules, or a plurality of modules or steps among them can be manufactured into a single integrated circuit module to realize. The present application is not limited to any specific combination of hardware and software.

[0081] The above describes the specific embodiments of the present application in combination with the drawings, but is not a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications or variations made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the protection scope of the present application.

Claims

1. A method of laser shock boundary connection in the same station, characterized in that, The method comprises the following steps: fixing the outer plate, reciprocally scanning along the folding line of the outer plate by using continuous wave laser, under the action of laser-induced thermal stress, the outer plate bends along the folding line, and the scanning is stopped when the set bending angle α is reached, and the pre-folding of the outer plate is completed; placing the inner plate on the pre-folded outer plate, making the edge of the inner plate coincide with the folding line of the outer plate, and using high-energy, short-pulse laser beam to perform step-by-step impact along the parallel line of the outer plate folding line, the pulsed laser induces explosive plasma, and the explosive plasma generates impact force; under the action of the impact force of the pulsed laser-induced explosive plasma, the outer plate further undergoes high-strain-rate bending deformation, and at the same time close to the inner plate, the pre-folding area of the outer plate impacts the upper surface of the inner plate at a very high speed, under the combined action of instantaneous severe deformation, high-speed interfacial shearing and compressive stress, atomic diffusion occurs between the outer plate and the inner plate, and laser impact welding occurs between the inner plate under the action of high-speed impact, thereby realizing the welding of the outer plate and the inner plate, and completing the edge covering connection; Firstly, the outer plate generates thermal stress under the action of continuous wave laser, and the thermal stress causes the outer plate to bend and deform, i.e. the pre-folding bending of α angle is caused by the thermal stress; Then, the outer plate further generates high-strain-rate bending deformation under the action of the explosive plasma impact force caused by the pulsed laser; the first bending deformation belongs to thermal deformation, and the second bending deformation belongs to cold deformation, compared with the way of completely bending through cold deformation on a bending machine, the material is less likely to break; It also includes pre-opening a through hole in the inner plate and / or the outer plate, under the action of laser shock wave, the material flows into the through hole to form an interlocking structure with a small opening and a large bottom, and the overlapping area of the inner plate and the outer plate is riveted; the through hole opened in the inner plate and / or the outer plate is a tapered hole; The method does not require a specific bending machine and die, and belongs to a non-contact edge covering connection method.

2. The laser shock boundary connection method in the same station as claimed in claim 1, wherein, It also includes pre-applying glue on the surface of the outer plate and / or the outer plate, and gluing the overlapping area of the inner plate and the outer plate.

3. The method of laser shock boundary connection in the same station as claimed in claim 1, wherein, Black paint or graphite is coated as an absorption layer on the surface of the outer plate irradiated by the pulsed laser, or aluminum foil or adhesive tape is pasted on the surface of the outer plate irradiated by the pulsed laser.

4. The method of laser shock boundary connection in the same station as claimed in claim 1, wherein, The set bending angle α is less than or equal to 60 degrees.

5. The method of laser shock boundary connection in the same station as claimed in claim 1, wherein, The power of the continuous wave laser is greater than 50 W; the power density of the pulsed laser is greater than 1 GW / cm 2 The pulse width is less than 20 ns; the continuous wave laser can also be a long pulse laser.

6. The method of laser shock boundary connection in the same station as claimed in claim 1, wherein, The high-energy, short-pulse laser beam is always located in the normal direction of the impact area of the outer plate.

7. The method of laser shock boundary connection in the same station as claimed in claim 1, wherein, The materials of the inner plate and the outer plate are the same or different metals of copper, aluminum, steel and titanium, and the inner plate can also be plastic, glass or ceramic.

8. A device for use in the method of laser shock boundary connection in the same position according to any one of claims 1 to 7, characterized in that: It comprises a workbench and a laser system, the workbench is provided with a base plate for carrying the outer plate and the inner plate, the base plate is provided with clamping tools for clamping the outer plate and the inner plate, and the laser system is used to provide continuous wave laser and high-energy, short-pulse laser beam to perform edge covering connection on the outer plate and the inner plate.

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