Design method for ensuring assembly of automobile front wall gap and surface difference

Abstract

This invention discloses a design method for ensuring the assembly of gaps and surface differences in the front bulkhead of an automobile. It includes treating the front bulkhead, composed of components such as fenders, hoods, and front grille frames, as a single "integral part." This method defines and constructs a positioning system for the assembly of this "integral part" with the vehicle body assembly. It also defines and constructs an assembly positioning system for exterior components such as headlights, lower headlight trim panels, and front grilles on this "integral part." Furthermore, it defines and constructs a positioning system for the internal components of the fenders, hood, and front grille frame as a single "integral part," effectively designing and controlling the dimensional chain links to ensure product quality from the design stage. This invention provides an effective design method that guarantees the quality of product design, development, and manufacturing, shortens the product development cycle, and reduces investment in process equipment, fully embodying the concept that "design is for manufacturing."

Description

Technical Field

[0001] This invention relates to a design method for ensuring the assembly of gaps and surface differences in the front of an automobile, belonging to the field of assembly design technology. Background Technology

[0002] As consumers' demands for personalized vehicles and their requirements for vehicle appearance and functionality increase, different companies primarily adopt methods such as product iteration and upgrades, and customized modifications to meet diversified market needs. This is especially true in the commercial vehicle sector, where annual commercial vehicle modifications are often achieved by keeping the main body structure largely unchanged and improving the front fascia. This inevitably involves the design and development of components such as fenders, hoods, front grille frames, headlights, lower headlight trim panels, and front grilles.

[0003] Meanwhile, the production methods of commercial vehicles differ from those of passenger vehicles. Commercial vehicles are characterized by low output and a wide variety of products. Factors such as small welding production line space, low cycle time, high degree of process complexity, frequent fixture switching, long body structure changeover time, and relatively low component precision result in the fact that the dimensional control accuracy and consistency of the mounting points of components such as fenders, hoods, and front grille frames on the body are far lower than the control level of passenger vehicles.

[0004] The conventional design and assembly sequence for the front of a car is to install the fenders, the hood, the front grille frame (commonly known as the headlight frame), and then install the headlights, the lower headlight trim, the front grille, and other components. This requires that the boundary contour and surface position of the headlights formed by the fenders and hood after assembly be precise, and that the position of the headlight fixing points on the front grille frame be precise. The relative positional relationship between these points and the boundary contour and surface of the headlights formed by the fenders and hood is also required to ensure that the gaps and surface differences between the fenders and hood, the headlights and fenders, and the headlights and hood after assembly meet the design specifications.

[0005] This issue is also a difficult assembly problem in the passenger car industry. Currently, most passenger cars adopt a design that only retains the uniform gap and surface matching requirements between the fender and the headlight. The hood covers the headlights and has no obvious gap or surface matching requirements, in order to ensure the appearance quality of the front part of the car.

[0006] The assembly of the front-end components of a certain light commercial vehicle initially employed conventional assembly positioning devices. However, due to factors such as an imperfect positioning system for the components, mismatch between the positioning device structure and the components, and issues with component manufacturing precision, the upper contour and surface dimensions of the headlights, formed by the fenders and hood, became unstable after assembly. This did not meet design and inspection specifications, resulting in a persistent number of quality defects, including uneven gaps between the headlights and surrounding components, mismatched surfaces, abnormal noise during hood opening and closing, worn paint on the hood hinges, and difficulty in hood rotation. These issues could only be resolved through extensive rework and repair.

[0007] Ensuring the accurate and stable relative positional relationships between components such as the hood and fenders, the front hood frame and fenders, and the front hood frame and hood after assembly is fundamental to solving the aforementioned problems. Therefore, a design method is proposed to ensure the assembly precision of gaps and surface differences in the front fascia. This method can quickly achieve the required assembly precision for gaps and surface differences in components such as the fenders, hood, front hood frame, headlights, lower headlight trim, and front grille, meeting the Dimensional Technical Specifications for Vehicle Design (DTS) requirements, thus ensuring the product can be launched into the market as planned. Summary of the Invention

[0008] The purpose of this invention is to provide a design method that ensures proper assembly of gaps and surface defects in the front of a car.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows: A design method for ensuring the assembly of gaps and surface differences in the front bulkhead of an automobile, comprising the following steps:

[0010] a) Treat body parts such as fenders, hoods, and front grille frames as a single unit;

[0011] b) Establish an assembly positioning system (RPS) for the integral component and the vehicle body assembly, wherein the system includes at least:

[0012] Z-axis main datum plane; X-axis main datum hole; Y-axis datum hole; X-axis auxiliary datum hole;

[0013] c) Establish an assembly positioning system within the integral component for the fender, hood, and front grille frame. This system uses the reference surface and reference hole on the fender as references, and defines the following:

[0014] Main reference surface and main and auxiliary reference holes of the hood;

[0015] The main reference surface, main and auxiliary reference holes, and auxiliary reference surface of the front cover frame;

[0016] d) Establish an assembly and positioning system for exterior trim components and integral parts. The exterior trim components include headlights, lower headlight trim panels, and front grilles. The system uses the main and auxiliary positioning holes H1 / H2 on the fender outer panel or front hood frame and the reference datum plane F as references, and defines the following respectively:

[0017] The main reference plane and main and auxiliary reference holes of the headlight;

[0018] Main reference surface and main and auxiliary reference holes of the lower trim panel of the headlight;

[0019] Front grille main reference surface and main and auxiliary reference holes;

[0020] e) Based on the dimensional deviation trend of the mounting points of the vehicle body assembly, an adjustable shim is installed between the integral component and the vehicle body to compensate for the mounting point deviation.

[0021] f) Based on the positioning system established in steps a) to e), design and verify the assembly positioning device for product design verification (DV) and process verification (PV) to ensure that the front bulkhead gap and surface difference meet the vehicle technical specifications (DTS).

[0022] Simply put, it means ensuring that after the assembly of the front-end components of the car, the gaps and surface differences between the components meet the requirements of the vehicle technical specifications (DTS). The components used for the installation of exterior parts such as headlights, headlight lower trim panels, and front grilles, which are composed of body parts such as fenders, hoods, and front cover frames, are regarded as a "whole component" and assembled onto the body assembly.

[0023] Analyze, define, and construct the assembly positioning relationship (RPS, Referencepoint system) between this "integral component" and the vehicle body assembly.

[0024] Analyze, define, and construct the assembly positioning relationships (RPS) between the internal components of this "monolithic part".

[0025] Analyze, define, and construct the positioning system (RPS) between the exterior trim components such as the headlights, lower headlight trim panels, and front grille and this "integrated component".

[0026] Based on the trend of dimensional deviations in the mounting points provided by the vehicle body assembly, the design of the parts to eliminate deviations and the size of the adjusting shims is defined.

[0027] Analyze, define, and construct a positioning reference point system (RPS) for product design verification assembly positioning device design used to control front panel gaps and surface differences.

[0028] Furthermore, the assembly positioning system between the integral component and the body assembly adopts a six-point positioning principle, in which the main reference planes A1 / A2 / A3 / A4 control the Z direction, the main reference holes B1 / B2 control the X direction, the reference holes C1 / C2 and the reference planes C3 / C4 control the Y direction, and the auxiliary reference holes D1 / D2 control the rotation around the Y axis.

[0029] Furthermore, an adjustable shim is installed between the inner fender panel and the front hood frame bracket. The thickness of the shim is determined based on the measured deviation trend of the mounting point on the vehicle body, and the thickness range is 1 mm to 5 mm.

[0030] Furthermore, the assembly positioning device includes:

[0031] Fender assembly positioning device, used to accurately position the process reference holes H1 / H2 of the fender;

[0032] The hood hinge assembly and positioning device is used to ensure the coaxiality of the hinge and its positional relationship with the hood;

[0033] The hood is equipped with a positioning device to control the positional relationship between the hood and the fender;

[0034] The front hood frame is equipped with a positioning device to control the positional relationship between the front hood frame and the fender.

[0035] Furthermore, the positioning system is used for three-dimensional dimensional chain simulation analysis in the product design verification (DV) stage, for the manufacturing and debugging of assembly positioning devices in the process verification (PV) stage, and for data traceability and closed-loop control through the MES system in the mass production stage.

[0036] Beneficial effects: Based on this design method, the product verification positioning device for the assembly of components such as fenders, hoods and hood hinges, and front cover frames can accurately verify the product design in the Design Verification (DV) process, enabling the designed and defined automotive front assembly technical specifications (DTS) to quickly meet the design expectations and significantly shorten the development cycle.

[0037] Based on the same design method, the positioning device for product process verification of components such as fenders, hoods, hood hinges, and front cover frames has also played a positive and important role in production validation (PV) and actual production. It has shortened the product sample verification cycle and ensured the correctness and consistency of the production process. At the same time, it has significantly saved investment costs in process equipment and is convenient, simple and effective to operate.

[0038] Practice has proven that the design method of treating body parts such as fenders, hoods, and front grille frames as a "whole component" to define and construct its connection and assembly positioning system with the body assembly, as well as the assembly positioning system between its internal components, and the design method of defining and constructing the assembly positioning system between exterior parts such as headlights, lower headlight trim panels, and front grilles and this "whole component" is feasible and has a simple and effective dimensional chain. Attached Figure Description

[0039] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0040] Figure 1 This is a schematic diagram of the structure of the automotive front bulkhead components of the present invention;

[0041] Figure 2a , Figure 2b , Figure 2c This is a schematic diagram of the positioning system between the "integral component" and the vehicle body assembly of the present invention;

[0042] Figure 3a , Figure 3b This is a schematic diagram of the internal component positioning system of the "integral part" of the present invention; wherein: Figure 3a The hood assembly base was shown. Figure 3b The assembly reference for the front hood frame is shown;

[0043] Figures 4a to 4f This is a schematic diagram of the positioning system between the exterior trim and the "integral part" of the present invention; wherein: Figure 4a The fender outer panel is shown as a reference for headlight mounting. Figure 4b The headlight mounting reference was shown. Figure 4c The reference for mounting the fender outer panel to the lower headlight trim panel is shown. Figure 4d The mounting reference for the lower headlight trim panel is shown. Figure 4e The reference points for front grille mounting are shown on the front hood frame. Figure 4f The front grille mounting reference is shown;

[0044] Figure 5a , Figure 5b This is a schematic diagram showing the position of the adjustment shims in the assembly of the present invention;

[0045] Figure 6a , Figure 6b Install positioning devices on the fenders ①;

[0046] Figure 6c , Figure 6d Engine hood hinge assembly positioning device ②;

[0047] Figure 6e Engine hood mounting positioning device ③;

[0048] Figure 6f Front hood frame assembly positioning device ④;

[0049] In the image: 1. Side door frame; 2. Inner fender panel; 3. Upper outer front panel; 4. Fender; 5. Hood; 6. Front grille frame; 7. Headlights; 8. Lower headlight trim panel; 9. Front grille; Detailed Implementation

[0050] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings:

[0051] Please see Figure 1 This embodiment provides a design method to ensure the assembly of gaps and surface differences in the front of a car. It includes treating the front of the car, which is composed of body parts such as fenders, hoods, and front grille frames, as a "whole part" to define and construct its positioning system for assembly with the body assembly, headlights, lower headlight trim panels, front grille, and other exterior parts.

[0052] The fenders, hood, front grille frame and other accessories are treated as a "whole unit", and their positioning system for assembly with the main body is defined and constructed.

[0053] The fenders, hood, front grille frame and other accessories are treated as a "mono-component", and the positioning system between its internal parts is defined and constructed.

[0054] The fenders, hood, front grille frame and other accessories are treated as a "whole unit", defining and constructing the positioning system of the car's headlights, lower headlight trim panels, front grille and other exterior accessories and their assembly.

[0055] Analyze the trend of dimensional deviations in the mounting points provided by the currently produced vehicle body, and define the parts to eliminate the deviations and the dimensions of the adjusting shims.

[0056] Guide the design, verification, and debugging of assembly positioning devices used to control gaps and surface differences in the front of automobiles during the production process.

[0057] Work process:

[0058] In the product development and design definition phase, such as Figure 2a , Figure 2b and Figure 2c As shown, the fender, hood, and front grille frame are first considered as a single "integral component." The assembly contact surface between this "integral component" and the inner fender panel is defined as the main assembly reference surface A1 / A2 / A3 / A4, controlling the Z-direction. Its assembly point with the upper part of the left and right side door frames is defined as the main X-direction reference hole B1 / B2, controlling the X-direction. Its contact surface with the upper part of the left and right side door frames is defined as the main Y-direction reference hole C3 / C4, controlling the Y-direction. The process reference hole constructed on the fender is defined as the Y-direction reference hole C1 / C4.2， Controlling the Y-direction, its assembly points with the lower parts of the left and right side door frames are defined as auxiliary reference holes D1 / D2 in the X direction, controlling rotation around the Y-axis. Simultaneously, the constructed process reference holes and the plane containing them serve as reference reference surfaces F1 / F2 and reference holes G1 / G2 for establishing the positioning system of other components within the "integral part".

[0059] like Figure 2c , Figure 3a , Figure 3b As shown, the fender, hood, and front cover frame are treated as a "monomeric component." Using F1 / F2 as the reference datum plane and G1 / G2 as the reference datum holes, the main datum planes a1 / a2 / a3 / a4 and the main and auxiliary datum holes b / c of ​​the hood are defined, clarifying the form and position relationship of the hood relative to the fender. The main datum planes e1 / e2 / e3 / e4, the main and auxiliary datum holes f / g, and the auxiliary datum planes d1 / d of the front cover frame are defined. 2， Clarify the shape and position relationship between the front grille frame and the fender.

[0060] like Figures 4a to 4f As shown, the fender, hood, and front grille frame are treated as a single "integral component." The main and auxiliary positioning holes H1 / H2 for the headlights and the lower headlight trim panel, as well as the reference plane I, are respectively arranged on the outer fender panel. The main reference planes h1 / h2 / h3 / h4 and main and auxiliary reference holes i / j for the automotive headlights are defined, as are the main reference planes k1 / k2 / k3 / k4 and main and auxiliary reference holes l1 / l2 / m1 / m for the lower headlight trim panel. 2， Define the positional relationship between the headlights and the lower headlight trim relative to the "integral component". Arrange the main and auxiliary positioning holes K1 / K2 for the front grille and the reference plane J on the front grille frame. Define the main reference planes n1 / n2 / n3 / n4 and the main and auxiliary reference holes o / p for the front grille. Define the main reference planes (L1 / L2 / L3 / L4) and the main and auxiliary reference holes M1 / M for the lower headlight trim. 2， Clarify the positional relationship of the front grille relative to the "integral component".

[0061] During the product development, design, and verification phase, such as Figure 5a , Figure 5b As shown, on the inner fender panel, a fixed bracket profile for assembling the front hood frame is defined, with a 3mm or 5mm gap between the front hood frame and the assembly surface in the X and Z directions, respectively. A shim with a shape and size adjustment as shown in the design drawing is defined, and the thickness of the shim is determined based on the dimensional deviation trend of the mounting point provided by the current production body body, to ensure the form and position relationship of the front hood frame relative to the "integral part".

[0062] Based on the aforementioned RPS design definition, the respective RPS positioning systems for the fender, hood, hood hinge, and front hood frame are established. Based on these, four assembly positioning devices are designed: a fender assembly positioning device; a hood hinge assembly positioning device; a hood assembly positioning device; and a front hood frame assembly positioning device. Each positioning device must strictly adhere to the aforementioned RPS requirements to ensure proper positioning.

[0063] like Figures 6a to 6f As shown, the assembly positioning device for controlling the gaps and surface differences of the front bulkhead includes: a fender assembly positioning device ①, which precisely positions the fender C1 / C2 position (i.e., the position of the process reference holes H1 / H2) by means of the device body and the upper front bulkhead; a hood hinge assembly positioning device ②, which precisely positions the hinge coaxiality by means of the device body and the upper front bulkhead to ensure smooth hood opening and to control the positional relationship between the hinge and the hood; a hood assembly positioning device ③, which precisely positions the hood and the device body to control the positional relationship between the hood and the left and right fenders; and a front hood frame assembly positioning device ④, which precisely positions the front hood frame and the device body to control the positional relationship between the front hood frame and the left and right fenders.

[0064] Practice has proven that this design method is effective, stable and reliable in the control and application of product design and development, product verification, process verification and manufacturing. The gaps and surface differences of the front part of the produced products meet the requirements of the vehicle technical specifications.

[0065] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the specific embodiments described above. The specific embodiments and descriptions in the specification are merely for further illustrating the principles of the invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the claims and their equivalents.

Claims

1. A design method for ensuring assembly of gaps and surface differences in the front bulkhead of an automobile, characterized in that, Includes the following steps: Step a treats the fender, hood, front grille frame, or other body parts to be designed as a single unit; Step b establishes the assembly positioning system (RPS) for the integral component and the vehicle body assembly. The system shall include at least: Z-axis main datum plane; X-axis main datum hole; Y-axis datum hole; X-axis auxiliary datum hole; Step c establishes an assembly positioning system between the fender, hood, and front hood frame within the integral component. The system uses the reference datum surface and datum hole on the fender as references and defines the following respectively: hood main datum surface and main and auxiliary datum holes; front hood frame main datum surface, main and auxiliary datum holes, and auxiliary datum surface. Step d establishes an assembly positioning system for exterior trim components and overall components. Exterior trim components include headlights, lower headlight trim panels, and front grille. The system uses the main and auxiliary positioning holes on the fender outer panel or front hood frame and the reference datum surface as references, and defines the following respectively: The main reference plane and main and auxiliary reference holes of the headlight; Main reference surface and main and auxiliary reference holes of the lower trim panel of the headlight; Front grille main reference surface and main and auxiliary reference holes; Step e involves setting an adjustable shim between the integral component and the body body according to the dimensional deviation trend of the mounting point of the body assembly, in order to compensate for the mounting point deviation. Step f, based on the positioning system established in steps a to e, designs and verifies the assembly positioning device for product design verification (DV) and process verification (PV) to ensure that the front bulkhead gaps and surface differences meet the vehicle technical specifications (DTS).

2. The method according to claim 1, characterized in that: The assembly positioning system between the integral component and the body assembly adopts the six-point positioning principle, in which the main datum plane controls the Z direction, the main datum hole controls the X direction, the datum hole controls the Y direction, and the auxiliary datum hole controls the rotation around the Y axis.

3. The method according to claim 1, characterized in that: The adjustable shim is set between the inner fender panel and the front cover frame bracket. The thickness of the shim is determined according to the measured deviation trend of the mounting point of the vehicle body, and the thickness range is 1mm to 5mm.

4. The method according to claim 1, characterized in that: The assembly positioning device designed according to step f is as follows: Fender assembly positioning device, used to accurately position the process reference holes of the fender; The hood hinge assembly and positioning device is used to ensure the coaxiality of the hinge and its positional relationship with the hood; The hood is equipped with a positioning device to control the positional relationship between the hood and the fender; The front hood frame is equipped with a positioning device to control the positional relationship between the front hood frame and the fender.

5. The method according to claim 1, characterized in that: The positioning system in step f is used for three-dimensional dimensional chain simulation analysis in the product design verification (DV) stage, for the manufacturing and debugging of the assembly positioning device in the process verification (PV) stage, and for data traceability and closed-loop control through the MES system in the mass production stage.

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