Front floor assembly welding method

Abstract

The invention relates to a front floor assembly welding method, and belongs to the technical field of automobile production. The front floor assembly welding method comprises the steps that a front seat rear cross beam assembly and other structural parts in the front floor assembly are fed together, and the front seat rear cross beam assembly and the other structural parts in the front floor assembly are in lap joint with a front floor body at a laser welding station. On a laser welding station, welding of the front seat rear cross beam assembly and the front floor body is completed in a laser deep penetration welding mode, meanwhile, the front floor body and other structural parts in the front floor assembly are welded together at a plurality of laser pre-welding points, and an integral first pre-welding part is formed. And the mechanical arm grabs the whole first pre-welded part to a spot welding station, welding between the front floor body and other structural parts in the front floor assembly is completed at the spot welding station in a spot welding mode, and meanwhile the first laser penetration fusion welding seam is covered and sealed in the spot welding mode. The feeding frequency of welding of the front floor assembly can be reduced, and the wading sealing performance of the front floor assembly is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile production, and in particular to a front floor assembly welding method. Background Art

[0002] An integrated battery pack is generally installed under the front floor assembly of a pure electric vehicle, which mainly consists of the front floor body, the front floor rear body, the front seat front crossbeam assembly, the front longitudinal beam upper cover, the battery pack mounting bracket, the middle channel connecting plate and the airbag ECU (Electronic Control Unit) mounting plate, the front seat rear crossbeam assembly, etc.

[0003] In the prior art, the front seat rear cross beam body of the front seat rear cross beam assembly adopts a Japanese-shaped roll-pressed structure, and needs to be connected to the front floor body through a laser welding process. The front floor assembly is a sealing part, and the water-tightness of the front floor assembly needs to be guaranteed. Since the front floor body is thin, it is very easy to produce breakdown after laser connection with the counterpart. The breakdown problem cannot be completely eliminated by changing the laser welding shape, clamp modification, compression compensation and other measures. Therefore, the spot welding process is usually used to connect the front floor body with other structural parts in the front floor assembly.

[0004] This requires that two separate loading ports be set up on the production line, and a set of positioning fixtures be configured at each loading port. Manual loading must be performed when the front floor body is connected to the front seat rear cross beam body of the front seat rear cross beam assembly and when the front floor body is connected to other components in the front floor assembly. This not only complicates the process, but also greatly increases equipment and labor costs. Summary of the invention

[0005] In view of this, the embodiment of the present disclosure provides a front floor assembly welding method, which can reduce the number of material loading times for welding the front floor assembly and ensure the water-tightness sealing performance of the front floor assembly. The technical solution is as follows:

[0006] The front floor assembly welding method comprises the following steps:

[0007] Step a, comprising: respectively bringing the front floor body, the front seat rear cross beam assembly, the battery front middle mounting bracket assembly, the airbag ECU mounting plate assembly, the front seat front cross beam assembly, the front longitudinal beam upper cover plate and the middle channel connecting plate assembly to the laser welding station for overlapping, and positioning them by the first fixture of the laser welding station;

[0008] Step b, comprising: welding together the overlapping parts of the front seat rear cross beam assembly and the front floor body by laser deep fusion welding, and welding together the overlapping parts of the battery front middle mounting bracket assembly, the airbag ECU mounting plate assembly, the front seat front cross beam assembly, the front longitudinal beam upper cover plate and the middle channel connecting plate assembly and the front floor body by laser deep fusion welding at multiple laser pre-welding points to form a first pre-welded part;

[0009] Step c comprises: loosening the first clamp, grabbing the first pre-welded part to the spot welding station through a robotic arm, and after positioning it through a second clamp of the spot welding station, the overlapping parts of the mounting bracket assembly in the front of the battery, the airbag ECU mounting plate assembly, the front cross beam assembly of the front seat, the front longitudinal beam upper cover plate and the middle channel connecting plate assembly and the front floor body are welded together by spot welding, wherein the first laser deep fusion weld formed by laser deep fusion welding on the laser pre-welded point is covered and sealed by spot welding to form a front floor assembly.

[0010] In a possible implementation, in step b, the first laser deep penetration weld is a cross-shaped weld.

[0011] In a possible implementation manner, the transverse weld and the longitudinal weld in the cross-shaped weld are connected to each other at their center positions.

[0012] In a possible implementation, the transverse weld and the longitudinal weld in the cross-shaped weld are equal in length.

[0013] In a possible implementation, the lengths of the transverse weld and the longitudinal weld in the cross-shaped weld are both 3 mm to 5 mm.

[0014] In a possible implementation, in step c, the diameter of the spot welding covering surface for covering and sealing the first laser deep penetration weld is 5 mm to 7 mm.

[0015] In a possible implementation, the front floor assembly further includes a front floor rear body, and the front floor assembly welding method further includes the following steps:

[0016] Step d includes: welding the front floor body and the front floor rear body together by spot welding to form a first front floor sub-assembly.

[0017] In a possible implementation, the spot welding station includes a first spot welding station and a second spot welding station, the first spot welding station has a third fixture, the second spot welding station has the second fixture, and step d is before step a;

[0018] The step d further includes: bringing the front floor body and the front floor rear body together through the first loading port to the first spot welding station for overlapping, and after positioning them through the third fixture, welding the overlapping parts of the front floor body and the front floor rear body together by spot welding to form the first front floor sub-assembly;

[0019] The step a further comprises: respectively placing the front seat rear cross beam assembly, the battery front middle mounting bracket assembly, the airbag ECU mounting plate assembly, the front seat front cross beam assembly, the front longitudinal beam upper cover plate and the middle channel connecting plate assembly to the laser welding station through the second loading port to form the second front floor sub-assembly, loosening the third fixture, and then grabbing the first front floor sub-assembly from the first spot welding station to the laser welding station by a mechanical arm, so that the front floor body and the second front floor sub-assembly are overlapped together and positioned by the first fixture;

[0020] The step c also includes: after releasing the first clamp, grabbing the first pre-welded part with the rear body of the front floor by a robot arm to the second spot welding station, and positioning it by the second clamp.

[0021] In a possible implementation, step c also includes: grabbing the first pre-welded part to the spot welding station through a robotic arm, and bringing the rear body of the front floor to the spot welding station through a third loading port and overlapping it with the front floor body, and then positioning the first pre-welded part and the rear body of the front floor by a second clamp, and welding the front floor body and the rear body of the front floor together by spot welding at the spot welding station.

[0022] In a possible implementation, each overlapping portion of the structural member and the front floor body has a plurality of laser pre-welding points, and the plurality of laser pre-welding points are respectively located on two opposite sides of the corresponding structural member;

[0023] Among them, the structural member is one of the battery front mounting bracket assembly, the airbag ECU mounting plate assembly, the front seat front cross beam assembly, the front longitudinal beam upper cover plate and the center channel connecting plate assembly.

[0024] In the scheme shown in the present disclosure, the front seat rear beam assembly and other structural parts in the front floor assembly are loaded together and overlapped with the front floor body at the laser welding station, so that the front seat rear beam assembly and other structural parts in the front floor assembly do not need to be loaded separately at two loading ports. At the laser welding station, the welding of the front seat rear beam assembly and the front floor body is completed by laser deep fusion welding, and the front floor body and other structural parts in the front floor assembly are welded together at multiple laser pre-welding points, so that the front floor body, the front seat rear beam assembly and other structural parts in the front floor assembly form an integral first pre-welded part at the laser welding station. In this way, the first pre-welded part can be grabbed by the robot arm as a whole to the spot welding station. The welding between the front floor body and other structural parts in the front floor assembly is completed by spot welding at the spot welding station, and the first laser deep fusion weld welded by laser deep fusion welding at the laser pre-welding point is covered and sealed by spot welding. Therefore, the number of times of loading materials when welding the front floor assembly can be reduced, and the water-tightness performance of the front floor assembly can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 is a structural schematic diagram of a first front floor assembly provided by an embodiment of the present disclosure;

[0027] Figure 2 is a schematic diagram of a disassembled structure of a first front floor sub-assembly provided in an embodiment of the present disclosure;

[0028] Figure 3 is a schematic diagram of a disassembled structure of a second front floor sub-assembly provided in an embodiment of the present disclosure;

[0029] Figure 4 is a structural schematic diagram of a second front floor assembly provided by an embodiment of the present disclosure;

[0030] Figure 5 is a structural schematic diagram of a mounting bracket assembly in the front of a battery provided by an embodiment of the present disclosure;

[0031] Figure 6 It is a structural schematic diagram of an airbag ECU mounting plate assembly provided by an embodiment of the present disclosure;

[0032] Figure 7 is a structural schematic diagram of a front crossbeam assembly of a front seat provided by an embodiment of the present disclosure;

[0033] Figure 8 is a structural schematic diagram of a front longitudinal beam upper cover plate provided by an embodiment of the present disclosure;

[0034] Fig. 9 is a structural schematic diagram of a middle channel connecting plate assembly provided in an embodiment of the present disclosure;

[0035] Fig.10 is a schematic flow chart of a first front floor assembly welding method provided by an embodiment of the present disclosure;

[0036] Fig.11 is a schematic flow chart of a second front floor assembly welding method provided by an embodiment of the present disclosure;

[0037] Fig.12 It is a schematic flow chart of a third front floor assembly welding method provided in an embodiment of the present disclosure.

[0038] Description of Reference Numerals

[0039] 100. First front floor sub-assembly; 200. Second front floor sub-assembly.

[0040] 101. Front floor body; 102. Front floor rear body; 1. Laser pre-welding point; 2. Front seat rear crossbeam assembly; 3. Battery front middle mounting bracket assembly; 4. Airbag ECU mounting plate assembly; 5. Front seat front crossbeam assembly; 6. Front longitudinal beam upper cover; 7. Center channel connecting plate assembly. DETAILED DESCRIPTION

[0041] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0042] This embodiment relates to a front floor assembly welding method, such as Figure 1 The figure shows the structure diagram of the first front floor assembly. Figure 2 The figure shows the disassembled structure diagram of the first front floor sub-assembly. Figure 3 The figure shows the disassembled structure diagram of the second front floor sub-assembly. Figure 4 The figure shows the structure diagram of the second front floor assembly. Figure 5 The figure shows the structure of the mounting bracket assembly in the front of the battery. Figure 6 The figure shows the structure of the airbag ECU mounting plate assembly. Figure 7 The figure shows the structure of the front crossbeam assembly of the front seat. Figure 8 The figure shows the structure diagram of the front longitudinal beam upper cover. Fig. 9 The figure shows the structural diagram of the middle channel connecting plate assembly. Fig.10 The figure shows the process diagram of the first front floor assembly welding method. Fig.11 The figure shows the process diagram of the second front floor assembly welding method. Fig.12 Shown is a schematic diagram of the third front floor assembly welding method.

[0043] refer to Fig. 9 As shown, the front floor assembly welding method includes the following steps:

[0044] Step a includes: putting the front floor body 101, the front seat rear cross beam assembly 2, the battery front middle mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover 6 and the middle channel connecting plate assembly 7 on the laser welding station respectively, overlapping them together, and positioning them by the first fixture of the laser welding station. For example, the front floor body 101, the front seat rear cross beam assembly 2, the battery front middle mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover 6 and the middle channel connecting plate assembly 7 can be put on the laser welding station respectively by hand. This avoids the need to load the front seat rear cross beam assembly 2 and other structural parts in the front floor assembly separately at two loading ports.

[0045] The front floor assembly is a sheet metal structure assembly located between the front cabin assembly and the rear floor assembly in the lower body sheet metal structure for carrying the driver and front passengers. The number, shape and position of the front floor body 101, the front seat rear cross beam assembly 2, the battery front middle mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover 6 and the middle channel connecting plate assembly 7 in the front floor assembly of different types of vehicles may be different. Figure 1 As shown in the example.

[0046] refer to Figure 1 As shown, the front floor body 101 can be one, the front seat rear cross beam assembly 2 can be one, the battery front middle mounting bracket assembly 3 can be four, the airbag ECU mounting plate assembly 4 can be one, the front seat front cross beam assembly 5 can be one, the front longitudinal beam upper cover plate 6 can be two, and the center channel connecting plate assembly 7 can be one.

[0047] The outer contour of the front floor body 101 can be a rectangle, the outer contour of the front seat rear cross beam assembly 2 can be a strip, the outer contour of the battery front mounting bracket assembly 3 can be a strip, the outer contour of the airbag ECU mounting plate assembly 4 can be a rectangle, the outer contour of the front seat front cross beam assembly 5 can be a strip, the outer contour of the front longitudinal beam upper cover plate 6 can be a strip, and the outer contour of the center channel connecting plate assembly 7 can be a rectangle with a U-shaped opening on one side.

[0048] Among them, continue to refer to Figure 1As shown, the front seat rear cross beam assembly 2, the battery front middle mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover 6 and the center channel connecting plate assembly 7 are all located on the mounting surface of the front floor body 101 and overlap with the mounting surface of the front floor body 101 respectively.

[0049] Furthermore, the front seat rear cross beam assembly 2 may be located at the rear end of the front floor body 101, and the front seat rear cross beam assembly 2 may be parallel to the rear side of the front floor body 101. The front seat front cross beam assembly 5 may be located in the middle of the front floor body 101, and the front seat front cross beam assembly 5 may be parallel to the front seat rear cross beam assembly 2. Both ends of the front seat rear cross beam assembly 2 and the front seat front cross beam assembly 5 may be flush with the left side and the right side of the front floor body 101, respectively.

[0050] The four battery front middle mounting bracket assemblies 3 and the airbag ECU mounting plate assembly 4 can all be located between the front seat rear cross beam assembly 2 and the front seat front cross beam assembly 5. The four battery front middle mounting bracket assemblies 3 can all be perpendicular to the front seat rear cross beam assembly 2, the rear side of the airbag ECU mounting plate assembly 4 can be parallel to the front seat rear cross beam assembly 2, and the four battery front middle mounting bracket assemblies 3 and the airbag ECU mounting plate assembly 4 can be arranged in sequence along the length direction of the front seat rear cross beam assembly 2, and the four battery front middle mounting bracket assemblies 3 can be located on the left and right sides of the airbag ECU mounting plate assembly 4 in pairs.

[0051] The front longitudinal beam upper cover plate 6 and the middle channel connecting plate assembly 7 can both be located on the side of the front seat front cross beam assembly 5 away from the front seat rear cross beam assembly 2. Both front longitudinal beam upper cover plates 6 can be perpendicular to the front seat front cross beam assembly 5, the rear side of the middle channel connecting plate assembly 7 opposite to the U-shaped opening can be parallel to the front seat front cross beam assembly 5, the two front longitudinal beam upper cover plates 6 and the middle channel connecting plate assembly 7 can be arranged in sequence along the length direction of the front seat front cross beam assembly 5, and the two front longitudinal beam upper cover plates 6 are respectively located on the left and right sides of the middle channel connecting plate assembly 7.

[0052] The two ends of the middle channel connecting plate assembly 7 can be overlapped on the rear side of the front seat front cross beam assembly 5 and the front side of the front seat rear cross beam assembly 2, respectively. The front side and rear side of the airbag ECU mounting plate assembly 4 can be overlapped on the rear side of the front seat front cross beam assembly 5 and the front side of the front seat rear cross beam assembly 2, respectively. The rear end of the front longitudinal beam upper cover plate 6 can be overlapped on the front side of the front seat front cross beam assembly 5, and the front end can extend from the front side of the front floor body 101. The rear side of the middle channel connecting plate assembly 7 can be overlapped on the front side of the front seat front cross beam assembly 5, and the two ends of the U-shaped opening can extend from the front side of the front floor body 101.

[0053] Step b comprises: welding together the overlapping parts of the front seat rear cross beam assembly 2 and the front floor body 101 by laser deep fusion welding, and welding together the overlapping parts of the battery front mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover plate 6 and the middle channel connecting plate assembly 7 and the front floor body 101 at multiple laser pre-welding points 1 by laser deep fusion welding to form a first pre-welded part.

[0054] Since the cross section of the front seat rear cross beam assembly 2 is usually a Japanese-shaped structure, the front seat rear cross beam assembly 2 and the front floor body 101 can be directly welded together at the overlapping portion thereof by laser deep fusion welding.

[0055] For example, the second laser deep penetration weld formed by laser deep penetration welding between the front seat rear cross beam assembly 2 and the front floor body 101 can be "straight", "C", or "Z". In this embodiment, the second laser deep penetration weld between the front seat rear cross beam assembly 2 and the front floor body 101 can be "straight", so that the welding speed is faster and the connection effect after welding is good.

[0056] Since the battery front center mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover 6 and the middle channel connecting plate assembly 7 are all relatively thin, the problem of breakdown is very likely to occur when the battery front center mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover 6 and the middle channel connecting plate assembly 7 are welded to the overlapping parts of the front floor body 101 by laser deep fusion welding.

[0057] To this end, only the battery front center mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover 6 and the middle channel connecting plate assembly 7 are welded together with the front floor body 101 by laser deep fusion welding at multiple laser pre-welding points 1, so that the battery front center mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover 6 and the middle channel connecting plate assembly 7 are fixedly connected with the front floor body 101 to form a first pre-welded part.

[0058] Step c comprises: loosening the first clamp, grabbing the first pre-welded part to the spot welding station through the robot arm, and positioning it through the second clamp of the spot welding station, and then spot welding the overlapping parts between the mounting bracket assembly 3 in the front of the battery, the airbag ECU mounting plate assembly 4, the front cross beam assembly 5 of the front seat, the front longitudinal beam upper cover plate 6 and the middle channel connecting plate assembly 7 and the front floor body 101, wherein the first laser deep melting weld welded by laser deep melting welding on the laser pre-welded point 1 is covered and sealed by spot welding to form the front floor assembly.

[0059] Since the battery front middle mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover 6 and the middle channel connecting plate assembly 7 are fixedly connected with the front floor body 101 at the laser welding station to form a first pre-welded part, the robot arm can directly grab the first pre-welded part as a whole to the spot welding station.

[0060] At the spot welding station, on the one hand, the battery front mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover 6 and the center channel connecting plate assembly 7 can be completely welded together with the front floor body 101 by spot welding, and on the other hand, the first laser deep melting weld that has been welded by laser deep melting welding on the laser pre-welding point 1 can be covered and sealed by spot welding.

[0061] From the above, it can be seen that the front seat rear cross beam assembly 2 and other structural parts in the front floor assembly are loaded together and overlapped with the front floor body 101 at the laser welding station, so that the front seat rear cross beam assembly 2 and other structural parts in the front floor assembly do not need to be loaded separately at two loading ports.

[0062] At the laser welding station, the front seat rear cross beam assembly 2 and the front floor body 101 are welded by laser deep fusion welding, and the front floor body 101 and other structural parts in the front floor assembly are welded together at multiple laser pre-welding points 1, so that the front floor body 101, the front seat rear cross beam assembly 2 and other structural parts in the front floor assembly form an integral first pre-welded part at the laser welding station. In this way, the first pre-welded part can be grabbed by the robot arm as a whole to the spot welding station.

[0063] The front floor body 101 is welded to other structural parts in the front floor assembly by spot welding at the spot welding station, and the first laser deep penetration weld formed by laser deep penetration welding of the laser pre-welding point 1 is covered and sealed by spot welding.

[0064] Therefore, the number of times of loading materials when welding the front floor assembly can be reduced, and the water-tightness performance of the front floor assembly can be ensured.

[0065] In one example, when loading, first place the front seat rear cross beam assembly 2, the battery front middle mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover 6 and the middle channel connecting plate assembly 7 to the correct position on the first fixture of the laser welding station to form a Figure 4 The second front floor sub-assembly 200 shown in the figure, and then the installation surface of the front floor body 101 covers the second front floor sub-assembly 200. In this way, after the second front floor sub-assembly 200 and the front floor body 101 are positioned by the first clamp, the accuracy of the connection position between the second front floor sub-assembly 200 and the front floor body 101 can be ensured, avoiding misalignment or offset, which affects the performance of the front floor assembly after welding.

[0066] In one example, reference Figures 4 to 8 As shown, in order to facilitate the subsequent sealing by spot welding, in step b, the first laser deep penetration weld is a cross-shaped weld. In this way, when the first laser deep penetration weld is sealed by spot welding, it is helpful to reduce the difficulty of sealing, and it can be easier to achieve sealing and achieve a better sealing effect, thereby avoiding affecting the water-proof sealing performance of the front floor assembly.

[0067] In one example, continue to refer to Figures 4 to 8 As shown, the transverse weld and the longitudinal weld in the cross-shaped weld are connected to each other at the center position. In this way, when the first laser deep-penetration weld is sealed by spot welding, it is helpful to reduce the difficulty of sealing, and it can be easier to achieve sealing and achieve a better sealing effect, thereby avoiding affecting the water-proof sealing performance of the front floor assembly.

[0068] In one example, continue to refer to Figures 4 to 8 As shown, the lengths of the transverse weld and the longitudinal weld in the cross-shaped weld are equal. In this way, when the first laser deep-penetration weld is sealed by spot welding, it is helpful to reduce the difficulty of sealing, and it is easier to achieve sealing and achieve a better sealing effect, thereby avoiding affecting the water-sealing performance of the front floor assembly.

[0069] In one example, the lengths of the transverse weld and the longitudinal weld in the cross weld are both 3 mm to 5 mm. For example, the lengths of the transverse weld and the longitudinal weld can both be 3 mm, 4 mm, or 5 mm.

[0070] Thus, on the one hand, it can prevent the first laser deep penetration weld from being too small, which will affect the firmness of the laser deep penetration welding between the front floor body 101 and other structural parts in the front floor assembly at the laser pre-welding point 1, and may cause separation between other structural parts in the front floor assembly and the front floor body 101. On the other hand, it can prevent the first laser deep penetration weld from being too large, which will make it difficult for the first laser deep penetration weld to cover and seal by spot welding, and affect the water sealing performance of the front floor assembly.

[0071] In one example, in step c, the diameter of the spot welding surface that covers and seals the first laser deep penetration weld is 5 mm to 7 mm. For example, the diameter of the spot welding surface can be 5 mm, 6 mm, or 7 mm. Thus, it can be ensured that the spot welding surface completely covers the first laser deep penetration weld, thereby ensuring the water-tightness of the front floor assembly.

[0072] In one example, the front floor assembly further includes a front floor rear body 102, and the front floor assembly welding method further includes the following steps:

[0073] Step d, comprising: welding the front floor body 101 and the front floor rear body 102 together by spot welding to form a Figure 2 A first front floor sub-assembly 100 is shown.

[0074] Therefore, when the processing material area is not large enough, the first front floor sub-assembly 100 is formed by the front floor body 101 and the front floor rear body 102, so that the water sealing performance of the front floor assembly can be guaranteed.

[0075] In one example, reference Fig.11 As shown, in order to reduce the number of loading times of the front floor assembly welding when the front floor assembly includes the front floor rear body 102 and ensure the water-tightness of the front floor assembly, the spot welding station includes a first spot welding station and a second spot welding station, the first spot welding station has a third fixture, the second spot welding station has a second fixture, and step d is before step a;

[0076] Step d also includes: bringing the front floor body 101 and the front floor rear body 102 together through the first loading port to the first spot welding station for overlap, and after positioning by the third fixture, welding the overlapped portions of the front floor body 101 and the front floor rear body 102 together by spot welding to form the first front floor sub-assembly 100. For example, the rear side of the front floor body 101 and the front side of the front floor rear body 102 are overlapped and welded together by spot welding.

[0077] Step a also includes: respectively placing the front seat rear cross beam assembly 2, the battery front middle mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover plate 6 and the center channel connecting plate assembly 7 to the laser welding station through the second loading port to form the second front floor sub-assembly 200, then releasing the third clamp, and then grabbing the first front floor sub-assembly 100 from the first spot welding station to the laser welding station through the robot arm, so that the front floor body 101 and the second front floor sub-assembly 200 are overlapped together and positioned by the first clamp.

[0078] Step c also includes: after releasing the first clamp, grabbing the first pre-welded component with the front floor rear body 102 to the second spot welding station by a robot arm, and positioning it by a second clamp.

[0079] In one example, reference Fig.12 As shown, step c also includes: grabbing the first pre-welded component to the spot welding station through the robot arm, and raising the front floor rear body 102 to the spot welding station through the third loading port and overlapping the front floor body 101, and then positioning the first pre-welded component and the front floor rear body 102 through the second clamp, and welding the front floor body 101 and the front floor rear body 102 together by spot welding at the spot welding station.

[0080] As described above, the spot welding connection between the front floor rear body 102 and the front floor body 101 in step d and the spot welding between the front floor body 101 and other structural parts in the front floor assembly in step c are completed at the same spot welding station. Compared with the previous example, one station can be reduced during the welding of the front floor assembly.

[0081] In one example, each overlapping portion of the structural member and the front floor body 101 has a plurality of laser pre-welding points 1, and the plurality of laser pre-welding points 1 are respectively located on opposite sides of the corresponding structural member. The structural member is one of the battery front middle mounting bracket assembly 3, the airbag ECU mounting plate assembly 4, the front seat front cross beam assembly 5, the front longitudinal beam upper cover plate 6, and the middle channel connecting plate assembly 7.

[0082] For example, the overlapped portion of the mounting bracket assembly 3 and the front floor body 101 in the front portion of the battery may have the following structure: Figure 5 The three laser pre-welding points 1 shown may also have four laser pre-welding points 1 or five laser pre-welding points 1 .

[0083] The overlapped portion between the airbag ECU mounting plate assembly 4 and the front floor body 101 may have three laser pre-welding points 1, or may have a plurality of laser pre-welding points 1. Figure 6 The four laser pre-welding points 1 shown may also have five laser pre-welding points 1 .

[0084] The overlapped portion of the front seat front cross beam assembly 5 and the front floor body 101 may have three laser pre-welding points 1, or may have four laser pre-welding points 1, or may have a plurality of laser pre-welding points 1. Figure 7 Five laser pre-weld points 1 are shown.

[0085] The overlapped portion of the front longitudinal beam upper cover plate 6 and the front floor body 101 may have three laser pre-welding points 1, or may have a plurality of laser pre-welding points 1. Figure 8 The four laser pre-welding points 1 shown may also have five laser pre-welding points 1 .

[0086] The overlapped portion between the middle channel connecting plate assembly 7 and the front floor body 101 may have the following features: Figure 5 The three laser pre-welding points 1 shown may also have Fig. 9 The four laser pre-welding points 1 shown may also have five laser pre-welding points 1 .

[0087] Therefore, the firmness of the front floor body 101 and other structural parts in the front floor assembly by laser deep fusion welding at the laser pre-welding point 1 can be ensured, thereby avoiding possible separation between the front floor body 101 and other structural parts in the front floor assembly.

[0088] In the disclosed embodiment, the front seat rear cross beam assembly 2 and other structural components in the front floor assembly are loaded together and overlapped with the front floor body 101 at a laser welding station, so that the front seat rear cross beam assembly 2 and other structural components in the front floor assembly do not need to be loaded separately at two loading ports.

[0089] At the laser welding station, the front seat rear cross beam assembly 2 and the front floor body 101 are welded by laser deep fusion welding, and the front floor body 101 and other structural parts in the front floor assembly are welded together at multiple laser pre-welding points 1, so that the front floor body 101, the front seat rear cross beam assembly 2 and other structural parts in the front floor assembly form an integral first pre-welded part at the laser welding station. In this way, the first pre-welded part can be grabbed by the robot arm as a whole to the spot welding station.

[0090] The front floor body 101 is welded to other structural parts in the front floor assembly by spot welding at the spot welding station, and the first laser deep penetration weld formed by laser deep penetration welding of the laser pre-welding point 1 is covered and sealed by spot welding.

[0091] Therefore, the number of times of loading materials when welding the front floor assembly can be reduced, and the water-tightness performance of the front floor assembly can be ensured.

[0092] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present disclosure can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0093] The above are only preferred embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A front floor assembly welding method, characterized in that: The front floor assembly welding method comprises the following steps: Step a, comprising: bringing the front floor body (101), the front seat rear cross beam assembly (2), the battery front middle mounting bracket assembly (3), the airbag ECU mounting plate assembly (4), the front seat front cross beam assembly (5), the front longitudinal beam upper cover plate (6) and the middle channel connecting plate assembly (7) to the laser welding station for overlapping and positioning by a first fixture of the laser welding station; Step b, comprising: welding together the overlapping portions of the front seat rear cross beam assembly (2) and the front floor body (101) by laser deep fusion welding, and welding together the overlapping portions of the battery front middle mounting bracket assembly (3), the airbag ECU mounting plate assembly (4), the front seat front cross beam assembly (5), the front longitudinal beam upper cover plate (6) and the middle channel connecting plate assembly (7) and the front floor body (101) by laser deep fusion welding at a plurality of laser pre-welding points (1) to form a first pre-welded part; Step c comprises: loosening the first clamp, grabbing the first pre-welded part to the spot welding station by a robot arm, and positioning it by a second clamp of the spot welding station, and then spot welding the overlapping parts of the mounting bracket assembly (3) in the front of the battery, the airbag ECU mounting plate assembly (4), the front cross beam assembly (5) of the front seat, the front longitudinal beam upper cover plate (6) and the middle channel connecting plate assembly (7) with the front floor body (101), wherein the first laser deep fusion weld formed by laser deep fusion welding on the laser pre-welded point (1) is covered and sealed by spot welding to form a front floor assembly.

2. The front floor assembly welding method according to claim 1, characterized in that: In step b, the first laser deep penetration weld is a cross-shaped weld.

3. The front floor assembly welding method according to claim 2, characterized in that: The transverse weld and the longitudinal weld in the cross-shaped weld are connected to each other at the center position.

4. The front floor assembly welding method according to claim 2, characterized in that: The transverse weld and the longitudinal weld in the cross-shaped weld are equal in length.

5. The front floor assembly welding method according to claim 2, characterized in that: The lengths of the transverse weld and the longitudinal weld in the cross-shaped weld are both 3 mm to 5 mm.

6. The front floor assembly welding method according to claim 5, characterized in that: In step c, the diameter of the spot welding covering surface for covering and sealing the first laser deep penetration weld is 5 mm to 7 mm.

7. The front floor assembly welding method according to claim 1, characterized in that: The front floor assembly further comprises a front floor rear body (102), and the front floor assembly welding method further comprises the following steps: Step d comprises: welding the front floor body (101) and the front floor rear body (102) together by spot welding to form a first front floor sub-assembly (100).

8. The front floor assembly welding method according to claim 7, characterized in that: The spot welding station comprises a first spot welding station and a second spot welding station, the first spot welding station has a third fixture, the second spot welding station has the second fixture, and step d is before step a; The step d also includes: bringing the front floor body (101) and the front floor rear body (102) together through the first loading port to the first spot welding station for overlapping, and after positioning by the third fixture, welding the overlapping parts of the front floor body (101) and the front floor rear body (102) together by spot welding to form the first front floor sub-assembly (100); The step a also includes: respectively placing the front seat rear cross beam assembly (2), the battery front middle mounting bracket assembly (3), the airbag ECU mounting plate assembly (4), the front seat front cross beam assembly (5), the front longitudinal beam upper cover plate (6) and the middle channel connecting plate assembly (7) to the laser welding station through the second loading port to form the second front floor sub-assembly (200), then releasing the third clamp, and then grabbing the first front floor sub-assembly (100) from the first spot welding station to the laser welding station by a mechanical arm, so that the front floor body (101) and the second front floor sub-assembly (200) are overlapped together and positioned by the first clamp; The step c also includes: after loosening the first clamp, grabbing the first pre-welded part with the rear body (102) of the front floor to the second spot welding station by a robot arm, and positioning it by the second clamp.

9. The front floor assembly welding method according to claim 7, characterized in that: The step c also includes: grabbing the first pre-welded component to a spot welding station by a robot arm, and bringing the front floor rear body (102) to the spot welding station through a third loading port and overlapping the front floor body (101), and then positioning the first pre-welded component and the front floor rear body (102) by a second clamp, and welding the front floor body (101) and the front floor rear body (102) together by spot welding at the spot welding station.

10. The front floor assembly welding method according to claim 1, characterized in that: The overlapped portion of each structural member and the front floor body (101) has a plurality of laser pre-welding points (1), and the plurality of laser pre-welding points (1) are respectively located on two opposite sides of the corresponding structural member; The structural member is one of the battery front mounting bracket assembly (3), the airbag ECU mounting plate assembly (4), the front seat front cross beam assembly (5), the front longitudinal beam upper cover plate (6) and the middle channel connecting plate assembly (7).

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