Connecting structure of roof and side wall, design method thereof and vehicle

Abstract

The application relates to a vehicle body, in particular to a connecting structure of a roof and a side wall, a design method of the connecting structure and a vehicle. The connecting structure comprises a roof body and a side wall body. The left and right edges of the roof body are provided with outwardly extending overlapping parts. The inner edge of the side wall body comprises a modeling section, a welding section and a reinforcing section which are sequentially connected from outside to inside. The overlapping part is in abutment with the welding section, and an opening upward welding groove is formed at the abutment position. The welding groove is used for filling welding material, facilitates laser head irradiation and heating of the welding material, and the roof body and the side wall body can be better connected when laser spot irradiation. The included angle between the plane where the welding section is located and the Z axis of the vehicle body and the length of the welding section at the upper end of the welding seam in the welding groove are obtained based on a pre-designed formula. The structure can effectively avoid adverse welding phenomena such as edge biting and burrs in the laser welding area of the vehicle roof. The structure is stable, practical and strong, and can improve the appearance and service performance of the vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the automobile body, specifically relates to the connecting structure of roof and side wall and its design method and vehicle. BACKGROUND

[0002] Laser brazing is not easy to produce thermal damage due to local heating, no splash, good appearance quality, and saves roof trim in car roof connection application. Because of its low cost, small weight, less work station, beautiful and other characteristics, it is rapidly popularized in roof connection. Because the structure of laser welding of the roof and the side wall is very strict, and the side wall and the roof are modeling surface or high visible B level surface, the appearance quality requirement is very high. If there is a defect in the structure design, the cost and cycle of the mold modification will be greatly affected. However, the structure of the laser brazing section of the roof and the side wall has not formed a systematic and reasonable design, which leads to the welding quality defects in the manufacturing process.

[0003] The patent document CN201811330206 discloses a method for preventing and solving the laser welding defects of the roof of the vehicle body, which only gives the part quality control and other solutions to solve the defects of the roof laser brazing from the manufacturing link, which belongs to the passive problem solving, and has not been optimized from the design source with the minimum cost. Therefore, the design idea of the section structure of the roof and the side wall laser brazing still needs to be developed. SUMMARY

[0004] The purpose of the present application is to provide a connecting structure of roof and side wall and its design method and vehicle to avoid the defects of roof laser brazing.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] In the first aspect, the present application provides a connecting structure of roof and side wall, comprising a roof body and a side wall body, the left and right edges of the roof body are provided with outwardly extending lap joints, the inner side edge of the side wall body comprises a modeling section, a welding section and a reinforcing section connected in turn from outside to inside, the lap joint abuts against the welding section, and an opening upward welding groove is formed at the abutting position, which is used to fill the welding material, so as to facilitate the laser head to irradiate and heat the welding material, and the roof body and the side wall body can be better connected when the laser spot is irradiated. The included angle between the plane where the welding section is located and the Z axis of the vehicle body In the formula, δ is the Y direction offset tolerance of the side wall body, H is the Z direction offset amount of the roof body when the side wall body is offset by δ; the length B of the welding section at the upper end of the welding seam in the welding groove is δ*sinβ.

[0007] By adopting the technical scheme, the relative relationship between the side body and the roof body is kept stable by means of the vehicle body structure design, which absorbs the manufacturing tolerance of parts, improves the rigidity of parts, reduces the rebound of the lap joint area, and the like, so that the laser head can irradiate and heat the parts, the parts are uniformly heated at the connection position, and the bite edge phenomenon is avoided. In addition, the posture of the laser equipment and the related parameters are adjusted to meet the reasonable heat radiation area of the lap joint part, so that the side body and the roof body can be uniformly heated, and the welding quality between the parts is guaranteed.

[0008] Since the welding segment of the side body is located at the plane with an included angle between the Z axis of the vehicle body In this way, the welding wire can flow uniformly in the weld after being heated by laser irradiation, the welding quality is guaranteed, and the side body has excellent formability.

[0009] Since the length B of the welding segment located at the upper end of the welding groove is δ*sinβ, the deviation from the design state caused by the manufacturing tolerance of the lap joint of the roof body and the side body is avoided, the laser spot is irradiated at the abutting position, the heating is uneven, and the bite edge, burr and other defects are caused.

[0010] Further limited, the free end of the lap joint portion is provided with a reinforcing portion gradually away from the welding segment.

[0011] By adopting the technical scheme, the structural strength of the edge of the roof body is improved, and the deformation of the edge of the lap joint portion during the welding process is avoided.

[0012] Further limited, the Z-direction distance between the lowermost end of the reinforcing portion and the upper surface of the reinforcing segment is not less than 1.5mm.

[0013] By adopting the technical scheme, the line profile requirement of the trimming edge of the roof body and the profile requirement of the side body are considered, and it is ensured that the edge reinforcing portion of the roof body does not interfere with the reinforcing segment of the side body when the roof body is dropped.

[0014] Further limited, the abutting position of the lap joint portion and the welding segment is rounded, and the radius of the rounding is 2-3mm.

[0015] By adopting the technical scheme, the welding wire filling area is small, and the welding wire immersion and paving effect is better after melting, and the weld surface is smoother.

[0016] Further limited, the lap joint portion and the welding segment are fixed by laser brazing.

[0017] In a second aspect, the present application provides a design method of a connection structure of a roof and a side wall, which comprises the following steps:

[0018] S1, obtain a body-in-white welding tolerance band, and obtain a Y-direction offset tolerance delta of the side body and a Z-direction offset of the roof body when the side body is offset delta;

[0019] S2, according to the welding design requirement, determine the fillet radius of the abutment position of the lap joint part;

[0020] S3, based on the calculation formula obtain the angle beta between the plane of the welding section and the Z-axis of the vehicle body, and obtain the length B of the welding section at the upper end of the welding seam in the welding groove based on the calculation formula B = delta * sin beta;

[0021] S4, according to the welding design requirement, determine the minimum safety gap between the side body and the wire guide nozzle of the welding equipment;

[0022] S5, based on the minimum safety gap between the side body and the wire guide nozzle of the welding equipment determined in S4, calculate the angle alpha between the plane of the shaping section and the Z-axis of the vehicle body.

[0023] By adopting the above technical scheme, the connection structure of the roof and the side wall can be optimized at the initial design stage, the development cycle is shortened, the probability of one-time design is improved, and the time and cost of later quality rectification are reduced.

[0024] In a third aspect, the application provides a vehicle comprising the connection structure of the roof and the side wall.

[0025] The application has the following advantages: the connection structure of the roof and the side wall is limited, that is, the angle alpha between the plane of the welding section and the Z-axis of the vehicle body is limited In the formula, delta is the Y-direction offset tolerance of the side body, H is the Z-direction offset tolerance of the roof body, and the length B of the welding section at the upper end of the welding seam in the welding groove is B = delta * sin beta, which can well control the welding seam width. The structure can effectively absorb manufacturing tolerances, reduce welding defects caused by part offset due to part tolerances, and facilitate adjustment of the laser welding equipment. In addition, the design of the laser welding process parameters matched with the structure can effectively avoid adverse welding phenomena such as edge biting and burrs in the laser welding area of the vehicle roof. The structure is stable, practical, and can improve the appearance and serviceability of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application.

[0027] Figure 1 It is a matching diagram of the roof body and the side body in the first embodiment of the application.

[0028] Figure 2 Figure 1 is a schematic diagram of the laser brazing section structure of the top cover body and the side body in the first embodiment of the present application;

[0029] Figure 3 Figure 2 is a schematic diagram of the dimensions that need to be paid attention to in the laser brazing section structure of the top cover body and the side body in the first embodiment of the present application;

[0030] Figure 4 Figure 3 is a schematic diagram of the relationship between the fillet radius of the abutment position of the lap joint and the welding wire filling area under the same weld width;

[0031] Figure 5 Figure 4 is a schematic diagram of the simulation of the consistency requirement of the weld width;

[0032] Figure 6 Figure 5 is a schematic diagram of the simulation of the change of the safety gap between the side body and the wire guide nozzle within the manufacturing tolerance range;

[0033] Figure 7 Figure 6 is a schematic diagram of the simulation of the change of the safety gap between the top cover body and the side body within the manufacturing tolerance range;

[0034] Figure 8 Figure 7 is a flow chart of the design method of the connection structure of the top cover and the side body in the second embodiment of the present application.

[0035] In the figure, 1-top cover body, 11-lap joint, 12-strengthening part;

[0036] 2-side body, 21-molding section, 22-welding section, 23-strengthening section;

[0037] 3-welding equipment, 31-wire guide nozzle, 32-welding wire;

[0038] 4-weld;

[0039] 5-vehicle body Z axis.

[0040] A-theoretical design safety gap value between the side body and the wire guide nozzle, B-the length of the welding section located at the upper end of the welding groove, C-theoretical design safety gap value between the free end of the strengthening part of the top cover body and the welding section of the side body, D-theoretical design safety gap value between the free end of the lap joint section of the top cover body and the strengthening section of the side body, a-the angle between the plane where the molding section is located and the vehicle body Z axis, β-the angle between the plane where the welding section is located and the vehicle body Z axis, δ-Y direction offset tolerance of the side body, H-Z direction offset tolerance of the top cover body when the side body is offset by δ;

[0041] 1N-the position of the top cover body when the inward offset amount of the side body reaches δ, 2W-the position of the top cover body when the outward offset amount of the side body reaches δ;

[0042] 12N-outer side body offset to the vehicle interior by δ, the free end position of the roof body reinforcement when the W-outer side body offset to the vehicle exterior by δ;

[0043] 2N-outer side body position when offset to the vehicle interior by δ, 2W-outer side body position when offset to the vehicle exterior by δ;

[0044] 3N-outer side body position of the wire guide when offset to the vehicle interior by δ, 3W-outer side body position of the wire guide when offset to the vehicle exterior by δ;

[0045] 4N-weld width when the N-outer side body offset to the vehicle interior by δ;

[0046] AW-distance from the wire guide when the W-outer side body offset to the vehicle interior by δ, AN-distance from the wire guide when the N-outer side body offset to the vehicle exterior by δ;

[0047] DN-Z-directional distance between the free end of the roof body lap joint and the reinforcement of the outer side body when the N-outer side body offset to the vehicle interior by δ;

[0048] DW-Z-directional distance between the free end of the roof body lap joint and the reinforcement of the outer side body when the W-outer side body offset to the vehicle exterior by δ. DETAILED DESCRIPTION

[0049] Other advantages and effects of the present application can be easily understood by those skilled in the art from the disclosure of this specification. The present application can also be implemented or applied in other different specific embodiments, and the details in this specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, and are not intended to limit the protection scope of the present application.

[0050] It should be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present application, and the drawings only show the components related to the present application, but are not drawn according to the number, shape and size of the components in actual implementation. The type, number and proportion of each component in actual implementation can be arbitrarily changed, and the layout type of the components can also be more complex.

[0051] Embodiment one, as Figures 1 to 7As shown, a roof and side wall connecting structure, comprising a roof body 1 and a side wall body 2, the roof body 1 left and right edges are provided with outwardly extending lap joints 11, the side wall body 2 is a side wall outer panel, and the inner side edge thereof comprises a modeling section 21, a welding section 22 and a reinforcing section 23 connected in sequence from outside to inside. The lap joint 11 abuts against the welding section 22, and forms an opening upward welding groove with the welding section 22 at the abutting position. The lap joint 11 and the welding section 22 are fixed by laser brazing, the welding groove is filled with solder wire 32, which is convenient for the laser head to irradiate and heat the solder wire, and after melting, cooling and solidification, a welding seam 4 is formed, and the roof body 1 and the side wall body 2 can be better connected when the laser spot is irradiated.

[0052] The included angle between the plane where the welding section 22 is located and the vehicle body Z axis 5 In the formula, δ is the Y-direction offset tolerance of the side wall body, and H is the Z-direction offset amount of the roof body when the side wall body is offset by δ. In this way, the solder wire can flow uniformly in the welding seam 4 after being irradiated and heated by the laser, ensuring the welding quality and meeting the excellent formability of the side wall body 1.

[0053] The length B of the welding section at the upper end of the welding seam in the welding groove = δ*sinβ. In this way, the deviation from the design state caused by the manufacturing tolerance of the lap joint of the roof body and the side wall body can be avoided, which causes the laser spot to irradiate at the abutting position, resulting in uneven heating, causing the generation of defects such as undercut and burr.

[0054] By adopting the above technical scheme, the relative relationship between the side wall body 1 and the roof body 2 is kept stable by absorbing the manufacturing tolerance of the parts, improving the rigidity of the parts and reducing the rebound of the lap joint area, which is beneficial to the irradiation and heating of the parts by the laser head to achieve uniform heating of the part connection and avoid the occurrence of undercut. Secondly, for the vehicle body structure of the invention, the posture and related parameters of the laser equipment are adjusted to meet the reasonable heat radiation area of the lap joint parts to ensure that the side wall body 1 and the roof body 2 can be uniformly heated, thereby ensuring the welding quality between the parts.

[0055] In this embodiment, the free end of the lap joint 11 is provided with a reinforcing portion 12 gradually away from the welding section 22. The reinforcing portion 12 improves the structural strength of the edge of the roof body 1, avoiding deformation of the edge position of the lap joint 11 during welding.

[0056] In this embodiment, the Z-direction distance between the lowermost end of the reinforcing portion 12 and the upper surface of the reinforcing section 23 is not less than 1.5 mm, which takes into account the line profile requirements of the roof body 1 cutting edge and the profile contour requirements of the side wall body 2, and ensures that the edge reinforcing portion 12 of the roof body 1 does not interfere with the reinforcing section 23 of the side wall body 2 when the roof body 1 is dropped.

[0057] In the embodiment, the lap joint part 11 and the abutment position of the welding section 22 are rounded, and the radius r of the rounding is 2-3 mm. By limiting the radius r of the rounding of the abutment position, the wire filling area is small, and thus the wire melting, immersion and paving effect is better, and the weld surface is smoother.

[0058] Embodiment two, a design method of a connection structure of a roof and a side wall, comprising the following steps:

[0059] S1, obtaining a white body welding tolerance band, the manufacturing precision of the whole vehicle is controlled according to ±δ, as shown in the figure, and obtaining the Y direction offset tolerance δ of the side wall body and the Z direction offset amount of the roof body when the side wall body offset δ based on the white body welding tolerance band. Figure 3

[0060] S2, according to the welding design requirement, the size of the roof welding rounding is determined, that is, the rounding radius of the abutment position of the lap joint part is determined; as shown in the figure, the change of the wire filling area is simulated when the rounding radius r of the lap joint part 11 of the roof body 1 is 2 mm, 3 mm and 4 mm respectively under the condition that the weld width is constant, when the rounding radius r of the lap joint part 11 of the roof body 1 is 2 mm, the wire filling area is S, when the rounding radius r of the lap joint part 11 of the roof body 1 is 3 mm, the wire filling area is S+S1, and when the rounding radius r of the lap joint part 11 of the roof body 1 is 4 mm, the wire filling area is S+S1+S2. It can be seen that the larger the rounding radius r of the lap joint part 11 of the roof body 1, the larger the wire filling area will be; under the condition of the same weld width, the smaller the wire filling area, the better the wire melting, immersion and paving effect, and the smoother the weld surface, so under the condition that the roof body forming process is feasible, the smaller the roof welding rounding 32 is better, and generally 2 mm is recommended; Figure 4

[0061] S3, confirming the included angle between the plane where the welding section 22 is located and the vehicle body Z axis, according to the actual production tolerance requirement, as shown in the figure, the Y direction offset tolerance δ of the side wall body, the Z direction offset amount H of the roof body when the side wall body offset δ and the included angle β between the plane where the welding section 22 is located and the vehicle body Z axis can be expressed by the tangent theorem of triangle, that is, Figure 5 and further the included angle β between the plane where the welding section is located and the vehicle body Z axis can be obtained based on the calculation formula The included angle β should ensure that the change of the side wall body offset amount and the change of the roof body offset amount are both within the manufacturing tolerance range, and meet the appearance DTS requirement.

[0062] ​​​Confirming the width of the weld 4, when the angle β between the plane of the welding section 22 and the Z axis of the vehicle body and the radius of the corner of the abutment position of the lap joint are determined, the width of the weld 4 is also determined, and the width of the weld is also related to the welding speed, i.e. the welding power. The weld width of the present application is considered under the same welding conditions.

[0063] Confirming the length of the welding section at the upper end of the weld in the welding groove, as shown in the figure, the length B of the welding section at the upper end of the weld in the welding groove is obtained based on the calculation formula B=δ*sinβ. This dimension mainly ensures that when the side body 2 moves within the tolerance range, the weld 4 is always on the welding section 22 of the side body 2, so that the width of the weld 4 is consistent, meeting the appearance quality requirements. Figure 5

[0064] S4, according to the welding design requirements, determining the minimum safety clearance between the side body 2 and the wire guide nozzle 31 of the welding equipment 3. As shown in the figure, the distance between the side body 2 and the wire guide nozzle 31 of the welding equipment 3 will vary according to the manufacturing tolerance. When the side body moves towards the inside of the vehicle, the distance between the side body 2 and the wire guide nozzle 31 will become smaller and smaller. When the offset of the side body 2 reaches δ, the distance between the side body and the wire guide nozzle is AN. When the side body 2 moves towards the outside of the vehicle, the distance between the side body 2 and the wire guide nozzle 31 will become larger and larger. When the offset of the side body 2 reaches δ, the distance between the side body and the wire guide nozzle is AW. From the formula: Figure 6 It can be seen that AW>A>AN, so we only need to confirm the value of AN, which is used as the minimum safety clearance between the side body and the wire guide nozzle of the welding equipment. The safety distance is recommended to be 1mm, i.e. the minimum safety clearance between the side body 2 and the wire guide nozzle 31 should be not less than 1mm, so as to ensure the normal welding posture of the wire guide nozzle 31, facilitate the weld quality control, and reduce the welding defects. Figure 6

[0065] S5, confirming the angle between the modeling section and the Z axis of the vehicle body, based on the minimum safety clearance AN between the side body and the wire guide nozzle of the welding equipment determined in S4, the angle α between the modeling section and the Z axis of the vehicle body is calculated.

[0066] Confirming the theoretical design safety clearance value A between the side body and the wire guide nozzle, according to the angle α between the modeling section and the Z axis of the vehicle body, the theoretical design safety clearance value A between the side body and the wire guide nozzle can be calculated.

[0067] Confirming the theoretical design safety clearance value D between the free end of the lap joint section of the roof body and the reinforcing section of the side body, as shown in the figure, Figure 7 ​​As shown, during the relative movement of the roof body 1 and the side body 2 within the tolerance, when the side body 2 is offset to the vehicle interior direction by δ, the Z-direction distance between the free end of the roof body's overlapping section and the reinforcing section of the side body is DN, and when the side body 2 is offset to the vehicle exterior direction by δ, the Z-direction distance between the free end of the roof body's overlapping section and the reinforcing section of the side body is DW, wherein Figure 7 It can be known that DN>D>DW; in the tolerance limit case, DW is recommended to be not less than 1.5 mm, while the line profile requirement of the roof body 1's cutting edge and the profile profile requirement of the side body 2 are taken into account, so as to ensure that the edge reinforcing part 12 of the roof body 1 does not interfere with the reinforcing section 23 of the side body 2 when the roof body 1 is dropped.

[0068] The theoretical design safety gap value C between the free end of the roof body's reinforcing part and the welding section of the side body can be reasonably set according to the actual situation.

[0069] By adopting the above technical scheme, the connection structure of the roof and the side body can be optimized at the initial design stage, the development cycle is shortened, the probability of one-time design is improved, and the time and cost of later quality rectification are reduced.

[0070] Embodiment three is a vehicle comprising the connection structure of the roof and the side body of embodiment one.

[0071] The above embodiments are only preferred embodiments for fully illustrating the present application, and the protection scope of the present application is not limited thereto. Any equivalent replacement or transformation of the present application based on the present application is within the protection scope of the present application.

Claims

1. A design method for a connection structure between a top cover and a side panel, characterized in that, The connecting structure of the roof and the side wall includes a roof body (1) and a side wall body (2), the roof body (1) is provided with an overlapping part (11) extending outward at the left and right edges, the inner side edge of the side wall body (2) includes a modeling section (21), a welding section (22) and a reinforcing section (23) connected in sequence from outside to inside, the overlapping part (11) abuts against the welding section (22), and an opening upward welding groove is formed at the abutting position, and the welding groove is used for filling welding material; The design method comprises the following steps: S1, acquiring a body-in-white welding tolerance band, and obtaining a Y-direction offset tolerance of the side body (2) based on the body-in-white welding tolerance band and a Z-direction offset H of the roof body (1) when the side body (2) is offset when the side body (2) is offset S2, according to the welding design requirement, the radius of the fillet at the abutting position of the overlapping part (11) is determined; S3, the included angle β between the plane of the welding section (22) and the Z axis (5) of the vehicle body is calculated based on the calculation formula β = arctan The included angle β between the plane of the welding section (22) and the Z axis (5) of the vehicle body is calculated based on the calculation formula β = arctan The length B of the welding section (22) at the upper end of the welding groove is calculated based on sin β. S4, according to the welding design requirement, the minimum safety gap between the side wall body (2) and the wire guide nozzle (31) of the welding equipment (3) is determined; S5, based on the minimum safety gap between the side wall body (2) and the wire guide nozzle (31) of the welding equipment (3) determined in S4, the included angle α between the plane where the modeling section (21) is located and the Z axis (5) of the vehicle body is calculated.

2. The method of designing a roof and side connection structure according to claim 1, characterized in that: The free end of the overlapping part (11) is provided with a reinforcing part (12) gradually away from the welding section.

3. The method of designing a roof and side connection structure according to claim 2, characterized in that: The Z direction distance between the lowermost end of the reinforcing part (12) and the upper surface of the reinforcing section (23) is not less than 1.5 mm.

4. The design method of the roof side connection structure according to claim 1 or 2, characterized in that: The abutting position of the overlapping part (11) and the welding section (22) is filleted, and the radius of the fillet is 2-3 mm.

5. The design method of the roof side connection structure according to claim 1 or 2, characterized in that: The overlapping part (11) and the welding section (22) are fixed by laser brazing.

6. A vehicle characterized by: The connecting structure of the roof and the side wall determined by the design method of the connecting structure of the roof and the side wall according to any one of claims 1-5.

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