A method of laser welding a truck cap

Abstract

The application relates to a truck top cover laser welding method, which comprises the following steps: respectively overlapping a left side top cover and a right side top cover with two sides of a front top cover in the left-right direction of a vehicle, and performing first limiting and fixing to form a placement structure with a front overlap part, a left overlap part and a right overlap part; placing a middle top cover on the placement structure and performing second limiting and fixing; overlapping a rear top cover with the middle top cover and the placement structure, and performing third limiting and fixing to form a top cover to-be-welded assembly; and performing laser welding along the extension track of the overlap part between the front top cover, the left side top cover, the right side top cover, the rear top cover and the middle top cover in the top cover to-be-welded assembly. The above steps separate the left side top cover and the right side top cover from the left side surrounding welding assembly and the right side surrounding welding assembly, adjust the block sequence, perform three times of limiting and fixing to form the top cover to-be-welded assembly, and then perform laser welding along the extension track of the overlap part, so that the positioning precision and the overlap quality are guaranteed, and a subsequent glue smearing process is saved.

Description

Technical Field

[0001] This application relates to the field of automotive engineering technology, and in particular to a method for laser welding truck roofs. Background Technology

[0002] Because of their large size, mainstream truck roofs are generally divided into multiple parts, such as the left roof, right roof, front roof, middle roof, and rear roof. During the welding process, the left and right roofs are usually welded separately to the left and right side panels to form the left side panel welding assembly and the right side panel welding assembly, respectively. After the assembly line is completed, the front roof, middle roof, and rear roof are then welded together in sequence to form the roof welding assembly and the body-in-white welding assembly.

[0003] Among these processes, the front, middle, and rear roof covers are often the last to be welded. After welding, the accumulated errors are often significant, leading to large deviations during roof welding and making it difficult to guarantee welding precision and quality. This can easily result in poor assembly of the roof cover components. Forced welding through positioning can cause excessive pre-stress at the weld points, resulting in poor stress distribution and increasing the risk of fatigue cracking later on. After the roof covers are assembled in sections, welding clamps often have to be inserted through openings such as doorways, sunroofs, and rear windows for welding. When some models are simplified and lack sunroofs or rear windows, larger welding clamps are needed to reach weld points at greater distances. Furthermore, the movement trajectory of the welding clamps becomes more complex. Therefore, the roof welding procedures for different body-in-white configurations are often different, complex, and costly. Summary of the Invention

[0004] This application provides a laser welding method for truck roofs to solve the problem in related technologies where the left and right roofs are first welded separately to the left and right side panels to form a left side panel welding assembly and a right side panel welding assembly, and then the front, middle, and rear roofs are sequentially welded to form a roof welding assembly and a body-in-white welding assembly. This method results in large cumulative deviations, making it difficult to guarantee welding accuracy and quality, and easily leading to poor assembly of roof mounting components.

[0005] In a first aspect, a method for laser welding truck roof covers is provided, comprising:

[0006] Secure the front top cover to the designated work position;

[0007] The left and right top covers are respectively overlapped with the front top cover on both sides in the left-right direction of the vehicle, and the first limiting and fixing is performed to form a placement structure with a front overlap, a left overlap and a right overlap.

[0008] The top cover is placed on the placement structure and then fixed in a second limiting position; the top cover has a front contact portion, a left contact portion, and a right contact portion corresponding to the front overlap portion, the left overlap portion, and the right overlap portion, respectively;

[0009] The rear top cover is overlapped with the middle top cover and the placement structure, and a third limiting fixation is performed to form the top cover assembly to be welded.

[0010] Laser welding is performed along the extended trajectory of the overlapping portion between the front top cover, left top cover, right top cover, rear top cover, and middle top cover in the top cover assembly to be welded.

[0011] In some embodiments, the front overlap is connected to the front top cover via a first profile transition portion, forming a first included angle for the laser welding head to enter and exit;

[0012] The front contact portion is connected to the top cover through the second surface transition portion, forming a second included angle for the laser welding head to enter and exit; both the front overlap portion and the front contact portion are planar overlap edges, and the overlap rate between them meets design requirement one.

[0013] In some embodiments, the left lap joint is connected to the left top cover via a third profile transition portion, forming a third included angle for the laser welding head to enter and exit;

[0014] The left contact portion is connected to the top cover through the fourth surface transition portion, forming a fourth included angle for the laser welding head to enter and exit; both the left overlapping portion and the left contact portion are planar overlapping edges, and the overlap rate between them meets design requirement two.

[0015] In some embodiments, the right overlap portion is connected to the right top cover via a fifth profile transition portion, forming a fifth included angle for the laser welding head to enter and exit;

[0016] The right contact portion is connected to the top cover through the sixth surface transition portion, forming a sixth included angle for the laser welding head to enter and exit; both the right overlapping portion and the right contact portion are planar overlapping edges, and the overlap rate between them meets design requirement three.

[0017] In some embodiments, the top cover also has a first rear overlap;

[0018] Both the left and right top covers are provided with a second rear overlap.

[0019] The rear top cover is provided with a rear contact portion that connects to the first rear overlap portion and the second rear overlap portion;

[0020] Among them, the second rear overlap, the first rear overlap, and the rear contact portion are all planar overlap edges; the overlap rate between the second rear overlap and the first rear overlap and the rear contact portion meets design requirement four;

[0021] The first rear lap joint is connected to the middle top cover through the seventh surface transition section, forming a seventh included angle for the laser welding head to enter and exit; the two second rear lap joints are connected to the left top cover and the right top cover respectively through the eighth surface transition section, forming an eighth included angle for the laser welding head to enter and exit.

[0022] In some embodiments, the front roof has side overlaps on both sides in the left-right direction of the vehicle;

[0023] The left and right top covers have side contact portions that are connected to the side overlapping portions; both the side contact portions and the side overlapping portions are planar overlapping edges, and the overlap rate between them meets design requirement five.

[0024] In some embodiments, the side overlap portion is connected to the front top cover via a ninth-shaped transition portion, forming a ninth angle for the laser welding head to enter and exit; the two side contact portions are respectively connected to the left and right top covers via tenth-shaped transition portions, forming a tenth angle for the laser welding head to enter and exit.

[0025] In some embodiments, positioning holes or positioning grooves are provided on the front top cover, left top cover, right top cover, rear top cover and middle top cover before the front top cover is fixed in the set position.

[0026] Then, based on the distribution of positioning holes or positioning slots on the front top cover, left top cover, right top cover, rear top cover and middle top cover, design the corresponding welding fixtures for the front top cover, left top cover, right top cover, rear top cover and middle top cover;

[0027] When performing the first, second, and third limit fixation, the corresponding welding fixtures are used to engage with the corresponding positioning holes or positioning slots to complete the limit fixation.

[0028] In some embodiments, the front top cover, left top cover, right top cover, rear top cover, and middle top cover have multiple positioning holes or positioning grooves;

[0029] The multiple positioning holes or positioning slots consist of three parts: the first part extends in the front-rear direction of the vehicle, the second part extends in the left-right direction of the vehicle, and the third part extends in the vertical direction of the vehicle.

[0030] In some embodiments, the plurality of positioning holes or positioning grooves further include a fourth part, which is provided along the outer periphery of the front top cover, the left top cover, the right top cover, the rear top cover and the middle top cover; the positioning holes or positioning grooves are circular.

[0031] The beneficial effects of the technical solution provided in this application include:

[0032] This application provides a method for laser welding truck roof covers. The method involves fixing the front roof cover at a designated station; overlapping the left and right roof covers with the front roof cover on both sides of the vehicle in the left-right direction, and performing a first limiting fixation to form a placement structure with a front overlap, a left overlap, and a right overlap; placing the middle roof cover on the placement structure and performing a second limiting fixation; the middle roof cover has a front contact portion, a left contact portion, and a right contact portion corresponding to the front overlap, left overlap, and right overlap, respectively; and overlapping the rear roof cover with the middle roof cover and the placement structure, and performing a third... The top cover is fixed in a limiting position to form a top cover assembly to be welded. Laser welding is performed along the extension trajectory of the overlapping parts between the front top cover, left top cover, right top cover, rear top cover and middle top cover in the top cover assembly to be welded. Through the above method, the left top cover and right top cover are separated from the left side welding assembly and the right side welding assembly. The block order is adjusted, and the left top cover, right top cover, front top cover, middle top cover and rear top cover are fixed in a limiting position three times by the welding fixture to form the top cover assembly to be welded. This ensures positioning accuracy and overlapping quality, thereby improving welding accuracy and welding quality, and the fatigue durability of the top cover connection.

[0033] In addition, the overall top laser welding is performed along the extension trajectory of the overlapping part, which can realize flexible production of different top cover sizes for light, medium and heavy trucks, and the layout of the welding line is more flexible. Moreover, the efficiency of laser welding is more than 3 times that of resistance spot welding, which improves production efficiency. Laser welding is a continuous and uninterrupted welding process, and the sealing between the parts of the top cover assembly is good, saving the subsequent glue application process, saving the investment in glue application, as well as the physical and process costs. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 A schematic diagram of the lap joint structure of the laser welding method provided in the related technology applied in the welding assembly of a car roof;

[0036] Figure 2 This is a schematic diagram of the segmented structure of a truck roof provided in an embodiment of this application;

[0037] Figure 3 A schematic diagram of the top cover assembly to be welded and its welding trajectory provided in an embodiment of this application;

[0038] Figure 4 This is a schematic diagram illustrating the overlapping relationship between the front top cover and the middle top cover in an embodiment of this application.

[0039] Figure 5 This is a schematic diagram illustrating the overlapping relationship between the side top cover and the middle top cover provided in an embodiment of this application.

[0040] In the diagram: 1. Front top cover; 2. Left top cover; 3. Right top cover; 4. Middle top cover; 5. Rear top cover; 6. First included angle; 7. Second included angle; 8. Third included angle; 9. Fourth included angle. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0042] The current status of roof welding in related technologies is as follows:

[0043] The mainstream truck roof welding assemblies still primarily use resistance spot welding, with less emphasis on more efficient and higher-quality advanced welding methods such as laser welding. Laser welding, however, is already being used in passenger car roof welding assemblies, as shown in the attached image. Figure 1 As shown, to ensure the overlap accuracy and welding contact surface between the top cover and the left and right side panels when it is finally assembled, the overlap structure design is quite complex. In particular, the top cover end is designed with a stamped negative angle, requiring additional flanging or shaping processes after the part is formed, resulting in complex mold processes and high part costs. This overlap structure is not suitable for the already complex top cover shape of trucks.

[0044] Truck welding lines typically need to accommodate welding of light, medium, and heavy-duty trucks on the same line. However, the dimensions of the roof covers for light, medium, and heavy-duty trucks vary significantly, requiring welding clamps of different sizes. This makes it difficult to simultaneously place welding clamps of multiple sizes at adjacent workstations, resulting in poor flexibility in the online co-line production of the roof cover assembly. Traditional resistance spot welding has low efficiency; statistics show that spot welding efficiency is only one-third or even lower than laser welding efficiency, potentially becoming a bottleneck at high production volumes. Furthermore, spot welding has a significant heat-affected zone, which can lead to quality problems such as roof cover deformation after welding thin roof cover plates. Since the roof cover is located at the top, considering the sealing performance of the cab, sealant is often applied to the weld overlap after spot welding to ensure a tight seal. Applying sealant not only increases costs but also adds complexity to the process.

[0045] Therefore, in response to the above-mentioned situation and problems, a laser welding method for truck roofs is proposed. This method addresses the issue of large cumulative deviations and difficulty in guaranteeing welding accuracy and quality caused by the previous welding method, which involved separately welding the left and right roofs to the left and right side panels to form the left and right side panel welding assemblies, respectively, and then sequentially welding the front, middle, and rear roofs to form the roof welding assembly and the body-in-white welding assembly.

[0046] Please see Figures 2-5 A method for laser welding truck roof covers, comprising the following steps:

[0047] Step S01: Fix the front top cover 1 in the set position;

[0048] Step S02: Overlap the left top cover 2 and the right top cover 3 with the front top cover 1 on both sides in the left-right direction of the vehicle, and perform the first limiting fixation to form a placement structure with a front overlap, a left overlap and a right overlap.

[0049] Step S03: Place the top cover 4 on the placement structure and perform a second limiting fixation; the top cover 4 has a front contact portion, a left contact portion, and a right contact portion corresponding to the front overlap portion, the left overlap portion, and the right overlap portion, respectively;

[0050] Step S04: Overlap the rear top cover 5 with the middle top cover 4 and the placement structure, and perform a third limiting fixation to form the top cover assembly to be welded.

[0051] Step S05: Perform laser welding along the extension trajectory of the overlapping area between the front top cover 1, left top cover 2, right top cover 3, rear top cover 5, and middle top cover 4 in the top cover assembly to be welded. The extension trajectory of the overlapping area is as follows: Figure 3 The dashed lines marking a, b, c, d, e, and f in the text.

[0052] The above steps separate the left and right top covers from the left and right perimeter welding assemblies, adjust the block sequence, and form the top cover assembly to be welded in three stages using welding fixtures: left top cover, right top cover, front top cover, middle top cover, and rear top cover. This step-by-step positioning and fixing, with the structure of the previous step serving as support for the next, ensures positioning accuracy and overlap quality, thereby improving welding precision and quality, and enhancing the fatigue durability of the top cover connection. Furthermore, the overall top laser welding follows the extension trajectory of the overlap area, enabling flexible production of different top cover sizes for light, medium, and heavy-duty trucks, and providing greater freedom in welding line layout. Laser welding is more than three times more efficient than resistance spot welding, further improving production efficiency. Laser welding is continuous and uninterrupted, ensuring good sealing between the parts of the top cover assembly, saving on subsequent adhesive application processes, investment in adhesives, and material and process costs.

[0053] In some preferred embodiments, the overlapping structure between the various parts of the roof is designed to conform to laser welding, optimizing the commonly used V-shaped overlapping in automobiles into a flat overlapping, simplifying the forming difficulty of the overlapping parts, thereby reducing tooling investment, process difficulty, and cost. For clarity regarding the actual overlapping relationships between the parts, please refer to the following description:

[0054] refer to Figure 4 Connection between front top cover 1 and middle top cover 4:

[0055] The front lap section is connected to the front top cover 1 through the first profile transition section, forming a first included angle 6 for the laser welding head to enter and exit;

[0056] The front contact portion is connected to the middle top cover 4 through the second surface transition portion, forming a second included angle 7 for the laser welding head to enter and exit; both the front lap portion and the front contact portion are planar lap edges, and the overlap rate between the two meets the design requirement one.

[0057] The overlap of the welding lap is 12mm. The drainage groove formed after welding the front top cover 1 and the middle top cover 4 is 25mm in size. The first and second surface transition parts each have an included angle of 145 degrees to facilitate the entry and exit of the laser welding head.

[0058] refer to Figure 5 The connection between the left top cover 2 and the middle top cover 4:

[0059] The left lap joint is connected to the left top cover 2 through the third surface transition part, forming a third included angle 8 for the laser welding head to enter and exit;

[0060] The left contact portion is connected to the middle top cover 4 via the fourth surface transition portion, forming a fourth included angle 9 for the laser welding head to enter and exit; both the left lap portion and the left contact portion are planar lap edges, and the overlap rate between them meets design requirement two. The overlap of the welding lap edge is 15mm, and the drainage groove formed after the left top cover 2 and the middle top cover 4 are 25mm in size. The third surface transition portion and the fourth surface transition portion form a 135-degree angle to facilitate the entry and exit of the laser welding head.

[0061] The connection between the right top cover 3 and the middle top cover 4 is the same as that between the left top cover 2 and the middle top cover 4, with consistent overlap. The right top cover 3 and the left top cover 2 are symmetrical along the vehicle's forward direction. The right overlap portion is connected to the right top cover 3 through the fifth surface transition portion, forming a fifth angle for the laser welding head to enter and exit; the right contact portion is connected to the middle top cover 4 through the sixth surface transition portion, forming a sixth angle for the laser welding head to enter and exit; both the right overlap portion and the right contact portion are planar overlap edges, and the overlap rate between them meets design requirement three.

[0062] Connection between rear top cover 5 and middle top cover 4:

[0063] The middle top cover 4 also has a first rear overlap; the left top cover 2 and the right top cover 3 are both provided with a second rear overlap; the rear top cover 5 is provided with a rear contact portion that connects to the first rear overlap and the second rear overlap; wherein, the second rear overlap, the first rear overlap and the rear contact portion are all planar overlap edges; the overlap rate of the second rear overlap and the first rear overlap with the rear contact portion meets design requirement four; wherein, the first rear overlap is connected to the middle top cover 4 through the seventh surface transition portion, and forms a seventh included angle for the laser welding head to enter and exit; the two second rear overlap portions are respectively connected to the left top cover 2 and the right top cover 3 through the eighth surface transition portion, and form an eighth included angle for the laser welding head to enter and exit.

[0064] Connection between front top cover 1, left top cover 2, and right top cover 3:

[0065] The side overlap is connected to the front top cover 1 through the ninth surface transition part, forming a ninth angle for the laser welding head to enter and exit; the two side contact parts are respectively connected to the left top cover 2 and the right top cover 3 through the tenth surface transition part, forming a tenth angle for the laser welding head to enter and exit; that is, a drainage groove is formed between the side overlap and the corresponding side contact part.

[0066] Based on the above, we consider optimizing the welding sequence of the top cover by changing the online welding to offline welding, which can eliminate the complexity and risks of online welding caused by different configurations; and by optimizing the overlapping structure design of each part of the top cover, we can improve the welding accuracy of the top cover assembly and ensure good welding quality.

[0067] In some preferred embodiments, to ensure welding positioning accuracy, considering that each top cover component is a flexible part, it is necessary that their overlapping relationship and position remain unchanged after the top cover assembly to be welded is formed. Therefore, the following design was also implemented:

[0068] Before fixing the front top cover 1 to the designated position, i.e. before step S01:

[0069] Positioning holes or positioning grooves are made on the front top cover 1, the left top cover 2, the right top cover 3, the rear top cover 5, and the middle top cover 4.

[0070] Then, based on the distribution of positioning holes or positioning grooves on the front top cover 1, left top cover 2, right top cover 3, rear top cover 5, and middle top cover 4, design welding fixtures corresponding to the front top cover 1, left top cover 2, right top cover 3, rear top cover 5, and middle top cover 4; during the first, second, and third limiting fixation, use the corresponding welding fixtures to engage with the corresponding positioning holes or positioning grooves to complete the limiting fixation.

[0071] The front top cover 1, left top cover 2, right top cover 3, rear top cover 5, and middle top cover 4 have multiple positioning holes or positioning grooves. These multiple positioning holes or positioning grooves consist of three parts: the first part extends in the front-rear direction of the vehicle, the second part extends in the left-right direction of the vehicle, and the third part extends in the vertical direction of the vehicle. This provides limiting in the vertical, left-right, and front-rear directions, ensuring positioning accuracy.

[0072] Furthermore, the multiple positioning holes or positioning grooves also include a fourth part, which is set along the outer periphery of the front top cover 1, left top cover 2, right top cover 3, rear top cover 5, and middle top cover 4; the positioning holes or positioning grooves are circular. This increases auxiliary over-positioning and further improves the welding accuracy between the various parts of the top cover welding assembly. Welding construction can also be performed on top covers of different sizes.

[0073] The beneficial effects of this application are:

[0074] Laser welding of the truck roof assembly was successfully achieved. By adjusting the segmentation sequence and performing edge welding followed by overall welding, welding precision and quality were improved, thereby enhancing the fatigue durability of the roof connection. Simultaneously, overall laser welding allows for flexible production of roofs of varying sizes for light, medium, and heavy-duty trucks, offering greater freedom in welding line layout. Furthermore, laser welding is more than three times more efficient than resistance spot welding, significantly improving production efficiency. Laser welding is a continuous, uninterrupted process, ensuring excellent sealing between roof assembly components and eliminating the need for subsequent adhesive application, thus saving on adhesive investment, material costs, and process costs. It simplifies the overlapping relationships between roof components, and the positioning structure is relatively simple, achieving the desired positioning effect while avoiding complex processing requirements for parts, saving on mold investment and material costs.

[0075] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0076] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0077] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the functions specified in one or more boxes. In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory. Memory may include non-persistent memory in computer-readable media, random access memory (RAM), and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0078] Computer-readable media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data.

[0079] Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random-access memory (SRAM), dynamic random-access memory (DRAM), other types of random-access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media do not include transient computer-readable media, such as modulated data signals and carrier waves. It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. In the absence of further restrictions, an element defined by the phrase "including one..." does not exclude the presence of other identical elements in the process, method, goods or equipment that include the element.

[0080] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and 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 of this application. Unless otherwise expressly specified and limited, the terms "installed," "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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0081] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0082] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for laser welding truck roof covers, characterized in that, It includes: Fix the front top cover (1) to the designated work position; The left top cover (2) and the right top cover (3) are respectively overlapped with the front top cover (1) on both sides in the left and right direction of the vehicle, and the first limiting fixation is performed to form a placement structure with a front overlap, a left overlap and a right overlap. The top cover (4) is placed on the placement structure and fixed for the second time; the top cover (4) has a front contact portion, a left contact portion and a right contact portion corresponding to the front overlap portion, the left overlap portion and the right overlap portion respectively; The rear top cover (5) is overlapped with the middle top cover (4) and the placement structure, and a third limiting fixation is performed to form the top cover assembly to be welded; Laser welding is performed along the extension trajectory of the overlapping part between the front top cover (1), left top cover (2), right top cover (3), rear top cover (5) and middle top cover (4) in the top cover assembly to be welded; The front lap section is connected to the front top cover (1) through the first surface transition section, and forms a first included angle (6) for the laser welding head to enter and exit. The front contact portion is connected to the top cover (4) through the second profile transition portion, and forms a second included angle (7) for the laser welding head to enter and exit; the front overlap portion and the front contact portion are both planar overlap edges; Before fixing the front top cover (1) to the set position, positioning holes are made on the front top cover (1), left top cover (2), right top cover (3), rear top cover (5) and middle top cover (4); Then, based on the distribution of the positioning holes on the front top cover (1), left top cover (2), right top cover (3), rear top cover (5) and middle top cover (4), design the welding fixtures corresponding to the front top cover (1), left top cover (2), right top cover (3), rear top cover (5) and middle top cover (4); When performing the first, second, and third limit fixation, the corresponding welding fixtures are used to engage with the corresponding positioning holes to complete the limit fixation.

2. The laser welding method for truck roofs as described in claim 1, characterized in that: The left lap joint is connected to the left top cover (2) through the third surface transition part, and forms a third included angle (8) for the laser welding head to enter and exit. The left contact portion is connected to the top cover (4) through the fourth surface transition portion, forming a fourth included angle (9) for the laser welding head to enter and exit; the left overlap portion and the left contact portion are both planar overlap edges.

3. The laser welding method for truck roofs as described in claim 1, characterized in that: The right lap joint is connected to the right top cover (3) through the fifth surface transition part, and forms a fifth included angle for the laser welding head to enter and exit; The right contact portion is connected to the top cover (4) through the sixth surface transition portion, forming a sixth included angle for the laser welding head to enter and exit; the right lap portion and the right contact portion are both planar lap edges.

4. The laser welding method for truck roofs as described in claim 1, characterized in that: The top cover (4) also has a first rear overlap; Both the left top cover (2) and the right top cover (3) are provided with a second rear overlap; The rear top cover (5) is provided with a rear contact portion that connects to the first rear overlap portion and the second rear overlap portion; Among them, the second rear overlap, the first rear overlap, and the rear contact portion are all planar overlap edges; The first rear lap joint is connected to the middle top cover (4) through the seventh surface transition section, forming a seventh angle for the laser welding head to enter and exit; the two second rear lap joints are connected to the left top cover (2) and the right top cover (3) through the eighth surface transition section, respectively, forming an eighth angle for the laser welding head to enter and exit.

5. The laser welding method for truck roofs as described in claim 1, characterized in that: The front roof (1) has side overlaps on both sides in the left-right direction of the vehicle; The left top cover (2) and the right top cover (3) have side contact portions that are connected to the side overlapping portions; Both the side contact area and the side overlap area are planar overlap edges.

6. The laser welding method for truck roofs as described in claim 5, characterized in that: The side lap joint is connected to the front top cover (1) through the ninth surface transition part, and forms a ninth angle for the laser welding head to enter and exit; the two side contact parts are respectively connected to the left top cover (2) and the right top cover (3) through the tenth surface transition part, and form a tenth angle for the laser welding head to enter and exit.

7. The laser welding method for truck roofs as described in claim 1, characterized in that: The front top cover (1), left top cover (2), right top cover (3), rear top cover (5) and middle top cover (4) have multiple positioning holes; The multiple positioning holes consist of three parts: the first part extends in the front-to-back direction of the vehicle, the second part extends in the left-to-right direction of the vehicle, and the third part extends in the vertical direction of the vehicle.

8. The laser welding method for truck roofs as described in claim 6, characterized in that: The multiple positioning holes also include a fourth part, which is set along the outer periphery of the front top cover (1), the left top cover (2), the right top cover (3), the rear top cover (5) and the middle top cover (4); the positioning holes are circular.

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