A design method for a longitudinal rail luggage rack

Abstract

The present invention provides a design method for a longitudinal rail luggage rack, which relates to the field of automobile luggage rack design. The scheme adopted is: comprising the following steps: S01: design requirement analysis; S02: drawing a sketch of the longitudinal rail luggage rack surface A through design software; S03: checking and adjusting the longitudinal rail luggage rack surface A according to the design requirements; S04: generating aluminum rods and cover plates according to the adjusted longitudinal rail luggage rack surface A; S05: compiling a parts list according to the adjusted longitudinal rail luggage rack surface A, and determining the quantity and type of various parts; S06: locking the longitudinal rail luggage rack surface A, checking and adjusting other parts of the longitudinal rail and other parts; S07: checking the longitudinal rail luggage rack composed of the adjusted parts as a whole, and adjusting other parts and parts other than the longitudinal rail luggage rack surface A to ensure that the design requirements are met. The present invention can avoid the adaptive adjustment of other related parts when optimizing the longitudinal rail structure, reduce the design workload, and improve the design efficiency.

Description

Technical Field

[0001] The invention relates to the field of automobile luggage rack design, and in particular to a design method of a longitudinal rail luggage rack. Background Art

[0002] A car longitudinal rail luggage rack is a device installed on the roof of a car, which can provide additional storage space and facilitate the carrying of large items. There are many types of car longitudinal rail luggage racks, including detached longitudinal rails and integrated longitudinal rails. The detached longitudinal rails are separated from the roof and are only connected to the roof at a few fixed points, while the integrated longitudinal rails are completely attached to the roof. Among them, the detached longitudinal rails are very convenient to install the luggage rack, so they are the more common longitudinal rails. When installing the luggage rack, you need to first adjust the distance between the front and rear luggage racks, and then fix them on the longitudinal rails with buckles.

[0003] The design method of the longitudinal rail luggage rack includes structural design, material selection, strength verification, etc. Before designing the longitudinal rail luggage rack, it is necessary to first conduct a design demand analysis, which includes determining the size, functional requirements, usage scenarios, installation conditions, etc. of the luggage rack. For example, it is necessary to clarify whether the luggage rack needs to carry heavy objects, whether it needs to adapt to different models, and whether it needs to meet specific aesthetic requirements; then the structural design is carried out, which is the core link of the longitudinal rail luggage rack design. During the design process, it is necessary to comprehensively consider factors such as the strength, rigidity, stability and aesthetics of the luggage rack. In this step, all external components that constitute the longitudinal rail luggage rack, such as aluminum rods, cover plates and internal parts such as rubber pads and bases, are often designed together, and then the matching relationship, fasteners, installation positioning, strength of related components and process feasibility are verified. If it does not meet the design requirements, the corresponding components are adjusted to determine the structure of many components; after the design is completed, the luggage rack is strength verified, which includes calculating the load-bearing capacity and stress distribution of the luggage rack, and comparing it with relevant standards to ensure the safety of the luggage rack.

[0004] When the above design method is adopted, since the A side of the longitudinal rail luggage rack, i.e. the exposed surface, involves the corresponding structure (including the aluminum rod and both sides of the cover plate) with high design requirements, the assessment content is different from the internal components of the longitudinal rail (including the base, rubber pad, and rubber pad limiter). At the same time, the structure of the aluminum rod and the cover plate is closely related to the structure of its internal components such as the cover plate and the base. When the structure of the aluminum rod and the cover plate is optimized according to the corresponding assessment requirements, it will cause changes in the structure of other related parts, and the related parts need to be adjusted accordingly. When the related parts are assessed, the structure of the aluminum rod and the cover plate is affected, and repeated adjustments and assessments are required, which greatly increases the design workload and affects the design efficiency. Summary of the invention

[0005] In order to solve the technical problem of large workload in structural design of longitudinal rail luggage racks in the above-mentioned prior art, the present invention provides a design method for a longitudinal rail luggage rack, which can avoid adaptive adjustments of other related components when optimizing the longitudinal rail structure, reduce design workload and improve design efficiency.

[0006] In the existing technology, luggage racks, as important exterior trim parts of automobiles, must not only meet the requirements of appearance but also load-bearing capacity. Designers can only design luggage racks based on the current strength of suppliers and their own capabilities. They lack control over suppliers and have poor design capabilities, resulting in repeated changes in structural data. The process cannot be achieved after the product mold is opened, resulting in waste of molds and materials. The risk assessment of the product cannot be controlled as early as possible, the designed product cycle is long, and the quality is low. At the same time, it affects the surrounding environment, greatly affecting the project progress and causing waste of material mold costs.

[0007] The technical solution adopted by the present invention to solve the above technical problems is: a design method of a longitudinal rail luggage rack, comprising the following steps: S01: Design requirements analysis; S02: Draw the A-side sketch of the longitudinal rail luggage rack using design software; S03: Check and adjust the A side of the longitudinal rail luggage rack according to the design requirements; S04: Generate aluminum rods and cover plates based on the adjusted A side of the longitudinal rail luggage rack; S05: Prepare a parts list based on the adjusted longitudinal rail luggage rack A side and determine the quantity and types of various parts; S06: Lock the A side of the longitudinal rail luggage rack, and check and adjust other parts of the longitudinal rail and other components; S07: Check the longitudinal rail luggage rack composed of the adjusted parts as a whole, and adjust other parts and parts except the A surface of the longitudinal rail luggage rack to ensure that the design requirements are met.

[0008] The present invention first determines the longitudinal rail luggage rack surface A in the corresponding design software, generates other longitudinal rail luggage components after checking the longitudinal rail luggage rack surface A, and freezes the longitudinal rail luggage rack surface A when checking other components, thereby avoiding the longitudinal rail luggage rack surface A and other components from influencing each other during adjustment, causing repeated adjustments and checks, greatly reducing the design workload and improving the design efficiency.

[0009] Further, the S03 comprises the following steps: S031: Check whether the top surface of the aluminum rod in the A side of the longitudinal rail luggage rack is feasible for the bending process and whether the position of the block line and parting line affects the appearance, and make adjustments; S032: Check whether the A surface of the longitudinal rail luggage rack meets the design requirements of external protrusions and make adjustments; S033: Check the height of the aluminum rod in the A side of the rail luggage rack and make adjustments.

[0010] The present invention conducts a feasibility analysis of the stretch-bending process and an analysis of the external protrusions when checking the A surface, thereby avoiding adjustments in the later stage of the longitudinal rail luggage rack design based on the process feasibility and the protrusion conditions, which would cause adaptive adjustments to other components and increase the workload. The design requirements can be met when the A surface structure is determined.

[0011] Furthermore, the S03 further includes: S034: Check the draft angle of the A side of the longitudinal rail luggage rack and make adjustments based on whether the demoulding angle of the leather grain is in the same direction as the draft angle of the A side of the longitudinal rail luggage rack.

[0012] The invention can prevent the problems of leather scratches on the aluminum rod and demoulding difficulties by checking the draft angle of the A surface of the longitudinal rail luggage rack.

[0013] Furthermore, the S03 further includes: S035: Check whether the gap D between the middle cover plate and the aluminum rod on the A side of the longitudinal rail luggage rack meets the design requirements; S036: Check whether the inclination angles on both sides of the middle cover plate of the longitudinal rail luggage rack A surface meet the design requirements; S037: Check whether there is any undercut in the middle cover of the A side of the longitudinal rail luggage rack and make adjustments.

[0014] The present invention can ensure that the cover plate meets the design requirements.

[0015] Further, the S06 comprises the following steps: S061: Freeze the A side of the longitudinal rail luggage rack; S062: Check and adjust the aluminum rod structure; S063: Determine the position, positioning accuracy and opening size of the main positioning and auxiliary positioning holes of the longitudinal rail luggage rack; S064: Check whether the rubber pad meets the design requirements and make adjustments; S065: Check whether the base meets the design requirements and make adjustments; S066: Check whether the waterproof foam meets the design requirements and make adjustments; S067: Check the interference relationship around the longitudinal rail luggage rack and the assembly operation space.

[0016] Further, the S062 includes the following steps: S0621: Check the wall thickness of the aluminum rod and adjust it; S0622: Determine the number of mounting points based on the length of the aluminum rod.

[0017] The invention can ensure that the strength and installation reliability of the aluminum rod meet the design requirements.

[0018] Furthermore, in S065, it is checked whether the mounting point of the mounting bolt of the base on the roof of the automobile exceeds the cover plate on one side.

[0019] The present invention can avoid the risk of water leakage.

[0020] Further, the S07 comprises the following steps: S071: Mold flow analysis, through simulation technology, analyze the rationality of plastic melt flow in the mold and cooling molding; S072: Motion verification: Use simulation technology to verify whether the base mounting bolts and mounting holes interfere with each other, and whether the longitudinal rail luggage rack and the car roof decorative strip interfere with each other. S073: Simulation analysis: using simulation technology to input the three-dimensional model of the luggage rack plate, the vehicle body model, the material properties of each component of the longitudinal rail luggage rack, and the simulation working conditions, to check whether the longitudinal rail luggage rack meets the deformation requirements; S074: Test analysis, test items include aluminum rod paint test, plastic parts test, and strength test.

[0021] Furthermore, Autodesk Moldflow software is used for mold flow analysis, catia software is used for motion verification, and SolidWork software is used for simulation analysis. In S02, catia software is used for design software.

[0022] It can be seen from the above technical solutions that the present invention has the following advantages: The present invention provides a design method for a longitudinal rail luggage rack, which first determines the longitudinal rail luggage rack surface A in corresponding design software, generates other longitudinal rail luggage components after checking the longitudinal rail luggage rack surface A, and freezes the longitudinal rail luggage rack surface A when checking other components, thereby avoiding mutual influence between the longitudinal rail luggage rack surface A and other components during adjustment, causing repeated adjustment and verification, greatly reducing the design workload and improving the design efficiency; by performing a feasibility analysis of the stretch bending process and an external protrusion analysis when checking the A surface, it can be avoided that the longitudinal rail luggage rack is adjusted according to the process feasibility and the protrusion situation in the later stage of the design, thereby causing adaptive adjustment of other components and increasing the workload, and the design requirements can be met when the A surface structure is determined; by checking the draft angle of the A surface of the longitudinal rail luggage rack, the problems of leather grain tearing of the aluminum rod and demolding difficulty can be prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0024] Figure 1 The structure of the longitudinal rail luggage rack Figure 1 .

[0025] Figure 2 The structure of the longitudinal rail luggage rack Figure 2 .

[0026] Figure 3 It is a flowchart of a specific implementation mode 1 of the present invention.

[0027] Figure 4 This is a schematic diagram of the A side of the longitudinal rail luggage rack.

[0028] Figure 5 It is a schematic diagram of calibrating the external protrusions of the A surface in the second specific implementation mode of the present invention.

[0029] Figure 6 It is a schematic diagram of checking the draft angle of the A surface of the longitudinal rail luggage rack in the second specific implementation mode of the present invention.

[0030] In the figure, 1. aluminum rod; 2. cover plate; 3. base; 4. rubber pad; 5. waterproof foam; 6. mounting bolts; 7. side panel; 8. top cover; 9. decorative strip. DETAILED DESCRIPTION

[0031] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent. Specific implementation method 1 like Figure 3 and Figure 4 As shown, this specific embodiment provides a design method for a longitudinal rail luggage rack, comprising the following steps: S01: Design requirements analysis; S02: Draw the A-side sketch of the longitudinal rail luggage rack using design software; S03: Check and adjust the A side of the longitudinal rail luggage rack according to the design requirements; S04: Generate aluminum rod 1 and cover plate 2 according to the adjusted longitudinal rail luggage rack surface A; S05: Prepare a parts list based on the adjusted longitudinal rail luggage rack A side and determine the quantity and types of various parts; S06: Lock the A side of the longitudinal rail luggage rack, and check and adjust other parts of the longitudinal rail and other components; S07: Check the longitudinal rail luggage rack composed of the adjusted parts as a whole, and adjust other parts and parts except the A surface of the longitudinal rail luggage rack to ensure that the design requirements are met.

[0033] This specific implementation method first determines the longitudinal rail luggage rack surface A in the corresponding design software, generates other longitudinal rail luggage parts after verifying the longitudinal rail luggage rack surface A, and freezes the longitudinal rail luggage rack surface A when verifying other parts. Compared with the method in the prior art that all parts are designed and then verified, this specific implementation method greatly reduces the mutual influence between parts during adjustment, avoids the mutual influence between the longitudinal rail luggage rack surface A and other parts during adjustment, and causes repeated adjustments and verifications, greatly reduces the design workload, and improves the design efficiency.

[0034] In this specific embodiment, surface A refers to the entire surface that is exposed to the outside and visible to the human eye after the longitudinal rail luggage rack is installed on the roof, that is, a spatial curved surface structure composed of the top surface and two side surfaces of the aluminum rod 1 and the outer surfaces of both sides of the cover plate 2; the sketch of surface A of the longitudinal rail luggage rack is drawn according to the size and shape requirements obtained in S01.

[0035] In S04, an empirical thickness value is assigned and the aluminum rod 1 and cover plate 2 structures are produced.

[0036] like Figure 1 and Figure 2 As shown, in this specific embodiment, the categories of the parts list include an aluminum rod 1, a cover plate 2, gaskets at both ends, an internal base 3, mounting bolts 6 and rubber pads 4; wherein the base 3 is an inverted "X"-shaped structure, the top of the base 3 is connected to the bottom of the mounting groove on the top cover 8 by means of mounting bolts 6, and the other leg of the base 3 is connected to the bottom surface of the aluminum rod 1 by means of bolts; a cover plate 2 is provided at the lower end of the aluminum rod 1, and clamping blocks are provided at both the upper and lower ends of the cover plate 2, the upper end of the outer side of the cover plate 2 (on the same side as the car door) is abutted against the groove on the side surface of the aluminum rod 1, and the lower end is connected to the side panel 7 by means of rubber pads 4 and decorative strips 9, the upper end of the cover plate 2 on the other side is clamped with a leg of the base 3, and the lower end is clamped with the top cover 8; generally, the cover plate 2 is an injection-molded plastic part. Specific implementation method 2 This specific embodiment provides a design method for a longitudinal rail luggage rack, comprising the following steps: S01: Design requirements analysis; S02: Draw the A-side sketch of the longitudinal rail luggage rack using design software; S03: Check and adjust the A side of the longitudinal rail luggage rack according to the design requirements; S04: Generate aluminum rod 1 and cover plate 2 according to the adjusted longitudinal rail luggage rack surface A; S05: Prepare a parts list based on the adjusted longitudinal rail luggage rack A side and determine the quantity and types of various parts; S06: Lock the A side of the longitudinal rail luggage rack, and check and adjust other parts of the longitudinal rail and other components; S07: Check the longitudinal rail luggage rack composed of the adjusted parts as a whole, and adjust other parts and parts except the A surface of the longitudinal rail luggage rack to ensure that the design requirements are met.

[0038] Wherein, the S03 comprises the following steps: S031: Check whether the top surface of the aluminum rod 1 in the A surface of the longitudinal rail luggage rack is feasible for the stretch bending process and whether the position of the block line and parting line affects the appearance, and make adjustments; S032: Check whether the A surface of the longitudinal rail luggage rack meets the design requirements of external protrusions and make adjustments; S033: Check the height of aluminum rod 1 in the A side of the rail luggage rack and make adjustments; S034: Check the draft angle of the A side of the longitudinal rail luggage rack and make adjustments based on whether the demoulding angle of the leather grain and the draft angle of the A side of the longitudinal rail luggage rack are in the same direction; S035: Check whether the gap D between the cover plate 2 and the aluminum rod 1 on the A surface of the longitudinal rail luggage rack meets the design requirements; S036: Check whether the inclination angles on both sides of the cover plate 2 on the A surface of the longitudinal rail luggage rack meet the design requirements; S037: Check whether there is any undercut in the middle cover plate 2 of the longitudinal rail luggage rack A surface, and make adjustments.

[0039] This specific implementation method performs a feasibility analysis of the stretch-bending process, an external protrusion analysis, a height calibration of the aluminum rod 1, a calibration of the draft angle of the longitudinal rail luggage rack A surface, and an adjustment of the cover plate 2 when checking the A surface. On the one hand, it ensures that the A surface as an exposed surface meets higher design requirements. On the other hand, it can avoid checking and adjusting the A surface when checking the longitudinal rail luggage rack according to the design requirements in the later stage of the design, which will cause adaptive adjustments to other components and increase the workload. It can ensure that the design requirements can be met when the A surface structure is determined.

[0040] In this specific implementation, in S031, since the top surface of the aluminum rod 1 is close to a plane, the design of the bending depression will be defective, so the protrusion needs to be adjusted. During the proofreading, the cross-section of the aluminum rod 1 requires the top and side surfaces to be arc surfaces with a chord height H2 of 0.5mm~1mm, and the person responsible needs to make adjustments; like Figure 2 and Figure 5As shown, in S032, according to GB11566, the A surface is checked to see if it meets the regulatory requirements for external protrusions. The fillet radius of the protruding parts on the outer surface should not be less than 2.5mm. However, this requirement does not apply to parts that protrude less than 1.5mm from the outer surface of the vehicle body, and parts that protrude more than 1.5mm and less than 5mm from the outer surface of the vehicle body but the outward part of the part is smooth. In S033, when the height H3 is high, H3 needs to be within the range of 30mm~35mm, which will affect the center of gravity of the vehicle and the operational stability of the vehicle during driving. Otherwise, the corresponding structure of the A surface is adjusted; In S034, the demoulding angle of the A surface of the longitudinal rail luggage rack needs to be determined according to the direction of the demoulding angle of the A surface of the longitudinal rail luggage rack and the demoulding angle of the leather grain. This design can prevent problems such as leather grain tearing and demoulding difficulties. In this specific implementation, the demoulding angle of the A surface of the longitudinal rail luggage rack is greater than 3°, and the demoulding angle of the leather grain is between 2.5° and 3°: ① The demoulding angle of the A side of the longitudinal rail luggage rack is in the same direction as the demoulding angle of the leather grain. The demoulding angle of the A side of the longitudinal rail luggage rack is the demoulding angle, which can be greater than 3°; ② The demoulding angle of the A side of the longitudinal rail luggage rack and the demoulding angle of the leather grain are in different directions. The demoulding angle of the A side of the longitudinal rail luggage rack is the demoulding angle of the A side of the longitudinal rail luggage rack + the demoulding angle of the leather grain; ③ The demoulding angle of the A side of the longitudinal rail luggage rack is in a different direction from the demoulding angle of the leather grain, and the depth of the leather grain is 25%~50%. The demoulding angle of the A side of the longitudinal rail luggage rack is the demoulding angle of the A side of the longitudinal rail luggage rack, which can be greater than 3°; In S035, check whether D is within the range of 0.2 mm to 0.5 mm. If not, make adjustments. In S036, check whether the inclination angle of the cover plate 2 is less than 10°, so that the product structure arrangement is easier after setting. If it is not less than 10°, make adjustments.

[0041] The above specific parameters are obtained through the design requirement analysis of S01. There may be differences in the parameters between different models. Specific implementation method three This specific embodiment provides a design method for a longitudinal rail luggage rack, comprising the following steps: S01: Design requirements analysis; S02: Draw the A-side sketch of the longitudinal rail luggage rack using design software; S03: Check and adjust the A side of the longitudinal rail luggage rack according to the design requirements; S04: Generate aluminum rod 1 and cover plate 2 according to the adjusted longitudinal rail luggage rack surface A; S05: Prepare a parts list based on the adjusted longitudinal rail luggage rack A side and determine the quantity and types of various parts; S06: Lock the A side of the longitudinal rail luggage rack, and check and adjust other parts of the longitudinal rail and other components; S07: Check the longitudinal rail luggage rack composed of the adjusted parts as a whole, and adjust other parts and parts except the A surface of the longitudinal rail luggage rack to ensure that the design requirements are met.

[0043] Wherein, the S03 comprises the following steps: S031: Check whether the top surface of the aluminum rod 1 in the A surface of the longitudinal rail luggage rack is feasible for the stretch bending process and whether the position of the block line and parting line affects the appearance, and make adjustments; S032: Check whether the A surface of the longitudinal rail luggage rack meets the design requirements of external protrusions and make adjustments; S033: Check the height of aluminum rod 1 in the A side of the rail luggage rack and make adjustments; S034: Check the draft angle of the A side of the longitudinal rail luggage rack and make adjustments based on whether the demoulding angle of the leather grain and the draft angle of the A side of the longitudinal rail luggage rack are in the same direction; S035: Check whether the gap D between the cover plate 2 and the aluminum rod 1 on the A surface of the longitudinal rail luggage rack meets the design requirements; S036: Check whether the inclination angles on both sides of the cover plate 2 on the A surface of the longitudinal rail luggage rack meet the design requirements; S037: Check whether there is any undercut in the middle cover plate 2 of the longitudinal rail luggage rack A surface, and make adjustments.

[0044] The S06 comprises the following steps: S061: Freeze the A side of the longitudinal rail luggage rack; S062: Check and adjust the structure of aluminum rod 1, including checking and adjusting the wall thickness of aluminum rod 1 and determining the number of installation points according to the length of aluminum rod 1; S063: Determine the position, positioning accuracy and opening size of the main positioning and auxiliary positioning holes of the longitudinal rail luggage rack; S064: Check whether the rubber pad 4 meets the design requirements and make adjustments; S065: Check whether the base 3 meets the design requirements and make adjustments. Also check whether the mounting point of the mounting bolt 6 of the base 3 on the automobile roof 8 exceeds the cover plate 2 on one side. S066: Check whether the waterproof foam 5 meets the design requirements and make adjustments; S067: Check the interference relationship around the longitudinal rail luggage rack and the assembly operation space.

[0045] like Figure 2As shown, in this specific implementation, in S062, when checking the wall thickness of the aluminum rod 1, it is necessary to ensure that the wall thickness A is within the range of 2.0 mm to 3.0 mm. If it does not meet the requirements, it is adjusted. When checking the number of installation points, if the length of the aluminum rod 1 does not exceed 1500 mm, 4 installation points are set. If it exceeds 1500 mm, one installation point is added to ensure the bearing capacity. In S063, after determining the positioning position, it is necessary to check to prevent shaking and poor fit after installation; In S064, check whether the flange height H1 of the rubber pad 4 is between 1.0 mm and 1.5 mm. If not, adjust it.

[0046] In S065, check whether the minimum distance B between the base 3 and the top cover 8 and the rounded corners of the side panel 7 is not less than 2mm. If so, make adjustments. At the same time, check the distance between the mounting bolts 6 of the base 3 and the two sides of the cover plate 2. The distance from the outer side of the cover plate 2 (on the same side as the door) should be within 150mm, and the distance from the other side of the cover plate 2 should be within 50mm. After such settings, water leakage can be effectively avoided. If not, make adjustments. In S066, the selection of waterproof foam 5 material is subject to constraints on density, hardness, tensile strength, elongation at break, compression set, and waterproof structure.

[0047] In S067, check that the interference C between the gaskets at both ends of the luggage rack and the top cover 8 and the side panel 7 is between 1.5 mm and 2.0 mm. If not, make adjustments. The assembly space must meet the requirements of the assembly process.

[0048] By proofreading other components on the premise of freezing the A surface, it can be ensured that, on the one hand, the cross-sectional design of the aluminum rod 1 is more reasonable, durable, and has a strong bearing capacity, and the requirements of the aluminum rod 1, rubber pad 4, sealing gasket, and waterproof foam 5 are reasonably defined, the coordination relationship of the surrounding environmental parts and the proofreading of the space are met, the components meet the design requirements, and meet the waterproof design. On the other hand, when the components are adjusted, it will not affect the A surface structure to prevent the A surface from changing. Specific implementation method four This specific embodiment provides a design method for a longitudinal rail luggage rack, comprising the following steps: S01: Design requirements analysis; S02: Draw the A-side sketch of the longitudinal rail luggage rack using design software; S03: Check and adjust the A side of the longitudinal rail luggage rack according to the design requirements; S04: Generate aluminum rod 1 and cover plate 2 according to the adjusted longitudinal rail luggage rack surface A; S05: Prepare a parts list based on the adjusted longitudinal rail luggage rack A side and determine the quantity and types of various parts; S06: Lock the A side of the longitudinal rail luggage rack, and check and adjust other parts of the longitudinal rail and other components; S07: Check the longitudinal rail luggage rack composed of the adjusted parts as a whole, and adjust other parts and parts except the A surface of the longitudinal rail luggage rack to ensure that the design requirements are met.

[0050] Wherein, the S03 comprises the following steps: S031: Check whether the top surface of the aluminum rod 1 in the A surface of the longitudinal rail luggage rack is feasible for the stretch bending process and whether the position of the block line and parting line affects the appearance, and make adjustments; S032: Check whether the A surface of the longitudinal rail luggage rack meets the design requirements of external protrusions and make adjustments; S033: Check the height of aluminum rod 1 in the A side of the rail luggage rack and make adjustments; S034: Check the draft angle of the A side of the longitudinal rail luggage rack and make adjustments based on whether the demoulding angle of the leather grain and the draft angle of the A side of the longitudinal rail luggage rack are in the same direction; S035: Check whether the gap D between the cover plate 2 and the aluminum rod 1 on the A surface of the longitudinal rail luggage rack meets the design requirements; S036: Check whether the inclination angles on both sides of the cover plate 2 on the A surface of the longitudinal rail luggage rack meet the design requirements; S037: Check whether there is any undercut in the middle cover plate 2 of the longitudinal rail luggage rack A surface, and make adjustments.

[0051] Wherein, the S06 comprises the following steps: S061: Freeze the A side of the longitudinal rail luggage rack; S062: Check and adjust the structure of aluminum rod 1, including checking and adjusting the wall thickness of aluminum rod 1 and determining the number of installation points according to the length of aluminum rod 1; S063: Determine the position, positioning accuracy and opening size of the main positioning and auxiliary positioning holes of the longitudinal rail luggage rack; S064: Check whether the rubber pad 4 meets the design requirements and make adjustments; S065: Check whether the base 3 meets the design requirements and make adjustments. Also check whether the mounting point of the mounting bolt 6 of the base 3 on the automobile roof 8 exceeds the cover plate 2 on one side. S066: Check whether the waterproof foam 5 meets the design requirements and make adjustments; S067: Check the interference relationship around the longitudinal rail luggage rack and the assembly operation space.

[0052] Wherein, described S07 comprises the following steps: S071: Mold flow analysis, through simulation technology, analyze the rationality of plastic melt flow in the mold and cooling molding; S072: motion check, using simulation technology to check whether the mounting bolts 6 of the base 3 interfere with the mounting holes, and whether the longitudinal rail luggage rack interferes with the top decorative strip 9 of the car; S073: Simulation analysis: using simulation technology to input the three-dimensional model of the luggage rack plate, the vehicle body model, the material properties of each component of the longitudinal rail luggage rack, and the simulation working conditions, to check whether the longitudinal rail luggage rack meets the deformation requirements; S074: Test analysis, test items include aluminum rod 1 paint test, plastic parts test, strength test.

[0053] In this specific implementation, the mold flow analysis uses Autodesk Moldflow software, the motion verification uses catia software, the simulation analysis uses SolidWork software, and the design software uses catia software.

[0054] By checking the designed longitudinal rail luggage rack, risk points in assembly, production, function, etc. can be discovered in advance, which greatly avoids risks and avoids producing products that do not meet the usage requirements, installation requirements, and strength requirements. High product quality is ensured from the beginning of product design.

[0055] This specific implementation method summarizes a set of design methods with strong logical thinking based on the structural form, layout plan, coordination relationship with surrounding environmental parts and simulation analysis of the luggage rack product. The method described in this specific implementation method is clear and organized, taking the entire process of luggage rack design as the route, and giving reasonable suggestions on the structural features, regulatory requirements, water leakage risks, undercut problems, bearing capacity, etc. required for the luggage rack design. This invention not only meets the styling requirements, but is also more practical, which greatly solves the problem of designers losing control during the design process due to lack of design experience, resulting in waste of molds and cost cycles.

[0056] From the above specific implementations, it can be seen that the present invention has the following beneficial effects: 1. By first determining the A side of the longitudinal rail luggage rack in the corresponding design software, and generating other parts of the longitudinal rail luggage after checking the A side of the longitudinal rail luggage rack, and freezing the A side of the longitudinal rail luggage rack when checking other parts, it is avoided that the A side of the longitudinal rail luggage rack and other parts affect each other during adjustment, resulting in repeated adjustments and checks, which greatly reduces the design workload and improves the design efficiency; 2. By conducting feasibility analysis of the bending process and external protrusion analysis during the A-surface verification, it is possible to avoid making adjustments based on process feasibility and protrusion conditions in the later stages of the longitudinal rail luggage rack design, which would result in adaptive adjustments to other components and increase workload. The design requirements can be met when the A-surface structure is determined; 3. By checking the draft angle of the A side of the longitudinal rail luggage rack, the problem of leather scratches on the aluminum rod 1 and difficulty in demolding can be prevented.

[0057] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A design method for a longitudinal rail luggage rack, characterized in that: The following steps are involved: S01: Design requirements analysis; S02: Draw the A-side sketch of the longitudinal rail luggage rack using design software; S03: Check and adjust the A side of the longitudinal rail luggage rack according to the design requirements; S04: Generate aluminum rods and cover plates based on the adjusted A side of the longitudinal rail luggage rack; S05: Prepare a parts list based on the adjusted longitudinal rail luggage rack A side and determine the quantity and types of various parts; S06: Lock the A side of the longitudinal rail luggage rack, and check and adjust other parts of the longitudinal rail and other components; S07: Check the longitudinal rail luggage rack composed of the adjusted parts as a whole, and adjust other parts and parts except the A surface of the longitudinal rail luggage rack to ensure that the design requirements are met.

2. The design method of the longitudinal rail luggage rack according to claim 1, characterized in that: The S03 comprises the following steps: S031: Check whether the top surface of the aluminum rod in the A side of the longitudinal rail luggage rack is feasible for the bending process and whether the position of the block line and parting line affects the appearance, and make adjustments; S032: Check whether the A surface of the longitudinal rail luggage rack meets the design requirements of external protrusions and make adjustments; S033: Check the height of the aluminum rod in the A side of the rail luggage rack and make adjustments.

3. The design method of the longitudinal rail luggage rack according to claim 2, characterized in that: The S03 also includes S034: checking and adjusting the draft angle of the A surface of the longitudinal rail luggage rack according to whether the demoulding angle of the leather grain and the draft angle of the A surface of the longitudinal rail luggage rack are in the same direction.

4. The design method of the longitudinal rail luggage rack according to claim 3, characterized in that: The S03 further includes: S035: Check whether the gap D between the middle cover plate and the aluminum rod on the A side of the longitudinal rail luggage rack meets the design requirements; S036: Check whether the inclination angles on both sides of the middle cover plate of the longitudinal rail luggage rack A surface meet the design requirements; S037: Check whether there is any undercut in the middle cover of the A side of the longitudinal rail luggage rack and make adjustments.

5. The design method of the longitudinal rail luggage rack according to any one of claims 1 to 4, characterized in that: The categories of the parts list include aluminum rods (1), cover plates (2), bases (3), mounting bolts (6), rubber pads (4), waterproof foam (5) and gaskets.

6. The design method of the longitudinal rail luggage rack according to claim 5, characterized in that: The S06 comprises the following steps: S061: Freeze the A side of the longitudinal rail luggage rack; S062: Check and adjust the aluminum rod structure; S063: Determine the position, positioning accuracy and opening size of the main positioning and auxiliary positioning holes of the longitudinal rail luggage rack; S064: Check whether the rubber pad meets the design requirements and make adjustments; S065: Check whether the base meets the design requirements and make adjustments; S066: Check whether the waterproof foam meets the design requirements and make adjustments; S067: Check the interference relationship around the longitudinal rail luggage rack and the assembly operation space.

7. The design method of the longitudinal rail luggage rack according to claim 6, characterized in that: The S062 comprises the following steps: S0621: Check the wall thickness of the aluminum rod and adjust it; S0622: Determine the number of mounting points based on the length of the aluminum rod.

8. The design method of the longitudinal rail luggage rack according to claim 7, characterized in that: In the S065, it is checked whether the mounting point of the mounting bolt of the base on the top cover of the automobile exceeds the cover plate on one side.

9. The design method of the longitudinal rail luggage rack according to claim 8, characterized in that: Described S07 comprises the following steps: S071: Mold flow analysis, through simulation technology, analyze the rationality of plastic melt flow in the mold and cooling molding; S072: Motion verification: Use simulation technology to verify whether the base mounting bolts and mounting holes interfere with each other, and whether the longitudinal rail luggage rack and the car roof decorative strip interfere with each other. S073: Simulation analysis: using simulation technology to input the three-dimensional model of the luggage rack plate, the vehicle body model, the material properties of each component of the longitudinal rail luggage rack, and the simulation working conditions, to check whether the longitudinal rail luggage rack meets the deformation requirements; S074: Test analysis, test items include aluminum rod paint test, plastic parts test, and strength test.

10. The design method of the longitudinal rail luggage rack according to claim 8, characterized in that: AutodeskMoldflow software is used for mold flow analysis, catia software is used for motion verification, SolidWork software is used for simulation analysis, and in S02, catia software is used for design software.

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