Design method of screw cover plate matching structure

Abstract

The application relates to a design method of a screw cover plate matching structure, which comprises the following steps: S1, optimizing a first matching surface of a target screw cover plate, and setting the first matching surface as an inwardly inclined inclined surface; S2, preliminarily matching the target screw cover plate with a profile of a target part; and S3, determining a second matching surface corresponding to the first matching surface on the target part. The method can solve a series of problems such as 'front end / middle end / terminal / after-sales' caused by a large number of special screw cover plates among various parts and vehicle models, so that the universalization target of sharing screw cover plates among different parts and even various vehicle models can be achieved, and the development cost of new vehicle models and the production cost are reduced.

Description

Technical Field

[0001] This invention relates to automotive parts, and more specifically to a design method for a screw cover matching structure. Background Technology

[0002] Automotive interior trim products, such as pillar trim panels and door trim panels, typically need to be fixed to the body sheet metal 3 using aftermarket mounting parts 4, i.e., screws or bolts. Therefore, for aesthetic reasons, an existing screw cover 1 is needed to conceal the exposed parts of the screws or bolts. Common design methods include... Figure 1 As shown, the component assembly includes a component body 2 and an existing screw cover 1. The component body 2 is fixed to the body sheet metal 3 by bolts, i.e., connectors 4 and nuts 5, and then the existing screw cover 1 is assembled and fixed to the component body 2. It should be noted that the joint between the existing screw cover 1 and the component body 2 is usually decorated by directly rounding the corners.

[0003] Based on the existing solutions, since the surface and structural requirements of interior parts vary across different vehicle models, their main demolding directions also differ. This results in each component body 2 having a different matching screw cover plate 1, all of which are custom-made parts. For example... Figure 2 ,relatively Figure 1 Although the main demolding direction and structure of component body 2 remain unchanged, the existing screw cover plate 1 cannot be replaced. Figure 1 The existing screw cover 12; because Figure 2 The relative surfaces of the middle component body 2 Figure 1 Since the surface of the component body 2 has changed, it is also necessary to develop a new screw cover 1 with a different surface; otherwise, the matching between the existing screw cover 1 and the component body 2 will result in an uneven appearance.

[0004] For example Figure 3 It can be seen that for two angles α and β of different sizes, regardless of whether they have the same chamfer LL or rounded corner Rr, their retraction amounts Y and Y1 from vertex P are different; and these different retraction amounts manifest as uneven gaps in the matching of product components. For example... Figure 4 In the process, the main demolding direction PD1 of component body 1 undergoes a significant change, such as... Figure 4The position of the main demolding direction PD1' will cause a large difference in the included angle between the two surfaces of the fillet at each parting line, resulting in a large difference in the fillet retraction. This will lead to an uneven visual appearance due to the misalignment gaps at each parting line. Furthermore, in order to achieve normal demolding, at each parting line, the mating surface 21 of the component body and the mating surface 11 of the existing screw cover plate 1 need to be angled according to the main demolding direction PD1' to become the first mating surface 11' and the second mating surface 21'. Ultimately, a new dedicated screw cover plate needs to be developed to solve this problem.

[0005] Thus, due to variations in the surface profile and different main demolding directions of the parts, a single vehicle will have multiple existing screw cover plates 1 with similar shapes, identical functions, but varying sizes. If multiple vehicle models are produced on the same production line, the number of existing screw cover plates 1 will increase exponentially. The ultimate problem is that a large number of existing screw cover plates with different shapes require: Front end: Suppliers invest in developing numerous molds, requiring the replacement of each mold or adjustment of the injection molding machine during production; each mold increases the burden of storage and daily maintenance. Mid-range: Logistics and transportation require separate packaging and differentiation; Terminal: OEMs or assembly workshops need to distinguish between different screw cover plates. When assembling, workers also need to distinguish and identify the screw cover plates of different parts to avoid incorrect assembly and affecting speed. After-sales service: Numerous spare parts, complicated management, etc.

[0006] CN201820225111.6 discloses an installation structure for a screw cover plate. Its innovation lies in the fact that the screw cover plate is integrated onto the part body through a hook, which solves some problems after the "middle" stage. However, since the number of screw cover plates has not been reduced, the problems at the "front end" still exist and have not been optimized or solved.

[0007] In reality, due to differences in the shape and surrounding environment of each product, the main demolding direction (the angle between the demolding direction and the main surface of the product) also varies, sometimes significantly. For example... Figure 5 As shown, the interior trim panels 6 on the A-pillar, 7 on the B-pillar, and 8 on the C-pillar of the same vehicle have different shapes and surfaces, and the angles between their respective main demolding directions and the product surfaces are also different. Among them, the interior trim panel 8 on the C-pillar differs the most from the interior trim panels 6 on the A-pillar and 7 on the B-pillar. Figure 3 , Figure 4 It is known that the amount of corner retraction is different for two surfaces with different included angles. If the same screw cover plate is used to match products with different included angles, there will be appearance problems such as uneven gaps and different heights. In addition, the inconsistent demolding direction will cause different mating surfaces of each part, which may even cause interference and prevent the assembly process from being completed.

[0008] To solve the aforementioned appearance matching problem, a dedicated screw cover plate is usually designed for each product. This results in a large number of screw covers. Consequently, the costs and efficiency of each stage—front-end, mid-end, end-end, and after-sales—significantly increase. For example: ① The "front-end" requires a large upfront investment to develop molds for multiple screw covers, with each mold costing at least 50,000 yuan. The workload for daily mold storage and maintenance also doubles. ② When injection molding different screw covers, each mold change and injection machine adjustment typically takes an hour, which is labor-intensive and time-consuming, significantly reducing work efficiency. ③ Different screw covers need to be packaged / transported separately, increasing logistics burden and costs. ④ On the "end-end" assembly line, separate areas need to be set up to distinguish and store different screw covers. Workers also need to identify and differentiate them during assembly, and there is a risk of incorrect assembly or rework affecting line speed.

[0009] In summary, existing technological solutions face challenges in production costs, management costs, and production efficiency, all of which urgently require solutions. Therefore, if a method or approach can be found to address the "front-end" problems, all subsequent issues will be completely resolved. Summary of the Invention

[0010] The purpose of this invention is to provide a design method for a screw cover matching structure, which can solve a series of problems caused by the numerous dedicated screw covers between various components and vehicle models, such as 'front-end / mid-end / terminal / after-sales' issues. This enables the commonality of screw covers between different components and even different vehicle models, thereby reducing the development costs of new vehicle models and lowering the cost of production and manufacturing.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A design method for a screw cover plate matching structure includes the following steps: S1, Optimize the first mating surface of the target screw cover plate by setting the first mating surface as an inwardly inclined slope; S2, perform preliminary matching between the target screw cover plate and the surface of the target component; S3, determine a second mating surface on the target component that corresponds to and mates with the first mating surface.

[0012] Furthermore, step S3 specifically includes: S31, Determine the matching reference line on the target component based on the parting surface of the target screw cover plate; S32, based on the main demolding direction of the target screw cover plate and the matching baseline, set the demolding angle and determine the demolding side and demolding side edge of the target screw cover plate; S33, based on the main demolding direction of the target component and the matching baseline, set the demolding angle, determine the demolding side and demolding side edge of the target component, wherein the demolding side edge of the target component and the demolding side edge of the target screw cover plate are in the same plane; S34, obtain the specific point on the demolding side edge of the target part that is furthest from the demolding side edge of the target screw cover plate; S35, determine a plane through a specific point and the main demolding direction of the target part, obtain the intersection line of the plane and the demolding side of the target part, and determine the demolding angle of the maximum demolding side of the target part based on the angle between the intersection line and the main demolding direction; S36, design the second matching surface based on the main demolding direction of the target component and the demolding angle of the side with the largest demolding side.

[0013] Furthermore, in S36, the demolding angle of the maximum demolding side of the target component is not less than the angle between the intersection line and the main demolding direction.

[0014] Furthermore, the tilt angle of the first matching surface is set as large as possible while meeting the requirements of structural performance and manufacturing process.

[0015] Furthermore, during the initial matching in S2, the matching method of overlapping or docking is selected according to the specific application environment and actual needs.

[0016] Furthermore, it also includes S4, which sets a transition area between the outer surface of the target component and the second mating surface.

[0017] Furthermore, the shape of the transition area is reasonably arranged according to the appearance quality requirements of the target component.

[0018] The beneficial effects of the present invention are as follows: The present invention first optimizes the first matching surface of the target screw cover plate by setting the first matching surface as an inwardly inclined slope, then performs a preliminary matching between the optimized target screw cover plate and the surface of the target component, and then determines a second matching surface on the target component that corresponds to and matches the first matching surface, thereby completely solving the problems of uneven matching appearance gap, unsightly appearance and inability to share screw cover plates, and improving the versatility of screw cover plates. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention.

[0020] Figure 1 This is one of the existing matching structure diagrams for screw cover plates; Figure 2This is the second schematic diagram of the existing matching structure of the screw cover plate; Figure 3 This is a schematic diagram illustrating the principle behind uneven matching gaps caused by chamfering with different included angles; Figure 4 This is a schematic cross-sectional view of the structure caused by the change in the demolding angle of the part, resulting in uneven matching clearance. Figure 5 These are examples of special screw cover plates used in vehicle interiors; Figure 6 This is a flowchart of the design method for the screw cover plate matching structure described in this invention; Figure 7 This is a schematic cross-sectional view of the target screw cover plate on the interior trim panel of the B-pillar before optimization. Figure 8 This is a schematic cross-sectional view of the optimized target screw cover plate on the interior trim panel of the B-pillar. Figure 9 This is a schematic cross-sectional view of the structure after the target screw cover plate and the interior trim panel on the C-pillar are initially matched; Figure 10 yes Figure 9 A magnified view of the overlapping and matching of the middle I region; Figure 11 yes Figure 9 A magnified view of the docking and matching in the central I region; Figure 12 This is a process diagram showing the largest demolded side of the interior panel on the C-pillar; Figure 13 This is the completed side view of the interior trim panel on the C-pillar, showing the largest demolded side. Figure 14 This is a diagram showing the matching effect between the target screw cover and the interior trim panel on the B-pillar without a transition area. Figure 15 This is one of the matching effect diagrams showing the elliptical transition area between the target screw cover and the interior trim panel on the B-pillar; Figure 16 This is one of the matching effect diagrams showing the elliptical transition area between the target screw cover and the interior trim panel on the B-pillar; In the diagram, 1—existing screw cover plate, 11—mating surface of existing screw cover plate, 11'—first mating surface, 2—part body, 21—mating surface of part body, 21'—second mating surface, 3—body sheet metal, 4—mounting part, 5—nut, 6—interior panel on A-pillar, 7—interior panel on B-pillar, 8—interior panel on C-pillar, 9—target screw cover plate, 10—matching baseline. Detailed Implementation

[0021] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0022] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0023] See Figure 6 The design method for the screw cover plate matching structure shown includes the following steps: S1, optimize the first matching surface of the target screw cover by setting the first matching surface as an inwardly inclined slope; in order to increase the adaptability of the screw cover, the inclination angle of the first matching surface is set as large as possible while meeting the structural performance and process requirements.

[0024] S2, perform a preliminary matching between the target screw cover plate and the surface of the target component. During the preliminary matching, select either an overlapping or butt joint matching method based on the specific application environment and actual needs.

[0025] S3, determine a second mating surface on the target component that corresponds to and mates with the first mating surface.

[0026] In this embodiment, step S3 specifically includes...

[0027] S31, determine the matching reference line on the target component based on the parting surface of the target screw cover plate.

[0028] S32, based on the main demolding direction of the target screw cover plate and the matching baseline, set the demolding angle and determine the demolding side and demolding side edge of the target screw cover plate.

[0029] S33, based on the main demolding direction of the target component and the matching baseline, set the demolding angle, determine the demolding side and demolding side edge of the target component, wherein the demolding side edge of the target component and the demolding side edge of the target screw cover plate are in the same plane.

[0030] S34, obtain the specific point on the demolding side edge of the target part that is furthest from the demolding side edge of the target screw cover.

[0031] S35, determine a plane through a specific point and the main demolding direction of the target part, obtain the intersection line of the plane and the demolding side of the target part, and determine the demolding angle of the maximum demolding side of the target part based on the angle between the intersection line and the main demolding direction. Preferably, the demolding angle of the maximum demolding side of the target part is not less than the angle between the intersection line and the main demolding direction.

[0032] S36, design the second matching surface based on the main demolding direction of the target component and the demolding angle of the side with the largest demolding side.

[0033] As a preferred embodiment of this method, it further includes step S4, which involves setting a transition region between the outer surface of the target component and the second mating surface. Preferably, the shape of the transition region is reasonably arranged according to the appearance quality requirements of the target component, specifically including the following steps.

[0034] S41, determine the shape of the transition area on the target component. The shape can be a perfect circle, ellipse, ring of equal width, ring of unequal width, square, rectangle, star, etc.; or it can be a style that transitions slowly with the appearance of the target component and is visually "invisible".

[0035] S42, along the main demolding direction of the target screw cover plate, project the shape onto the surface of the target part to obtain the projection line.

[0036] S43, create the transition area based on the projection lines and upper limit lines of the transition area on the target component. The transition area can be a conical surface composed of straight lines, an intentionally expressed aggregate composed of convex, concave, or wavy surfaces, or a collection of multiple shape features. These shape features include a collection of multiple curved or straight features arranged according to a certain rule to create a radiating effect, and a collection of multiple small features arranged through arraying and scaling techniques to create a strong perspective effect. Furthermore, the surface of the transition area can be textured, painted, or otherwise modified to improve its appearance.

[0037] The screw cover plates for the B-pillar and C-pillar interior trim panels are shared for explanation; see [link / reference]. Figure 5 The main demolding directions of the interior trim panel 7 on the B-pillar and the interior trim panel 8 on the C-pillar are quite different. It is proposed to share the target screw cover plate 9 of the interior trim panel 7 on the interior trim panel 8 on the C-pillar. The specific steps are as follows: S1, Optimize the first mating surface 11' of the target screw cover plate 9 by setting the first mating surface as an inwardly inclined slope. Figure 7 A schematic cross-sectional view of the target screw cover plate on the interior trim panel of the B-pillar before optimization. Figure 8A schematic cross-sectional view of the optimized target screw cover plate for the interior trim panel on the B-pillar shows that a first matching surface 11' is added at the parting surface PL of the target screw cover plate 9. The optimized first matching surface 11' of the target screw cover plate 9 is an inwardly inclined slope, and there is a step difference between the first matching surface 11' and the rounded corner of the edge of the target screw cover plate 9. The step difference is set according to the mold process. In this embodiment, the step difference is 0.5mm. The angle θ between the first matching surface 11' and the main demolding direction PD1 of the screw cover plate is defined as the demolding angle of the target screw cover plate. The inclination angle of the first matching surface 11' is set as large as possible while meeting the structural performance and process requirements, so that the demolding angle is as large as possible. In this embodiment, the angle θ is set to 55° so that parts with greater differences in the main demolding directions PD2 of the target parts can share the target screw cover plate 9.

[0038] S2, perform preliminary matching between the target screw cover plate and the surface of the target component. Position the target screw cover plate 9 at the fixing point corresponding to the target component, i.e., the interior trim panel 8 on the C-pillar, ensuring the edge of the target screw cover plate 9 is lower than the surface of the interior trim panel 8 on the C-pillar, with a drop a of approximately 0.5mm. See [link / reference]. Figure 9 The angle between the main demolding direction PD1 of the target screw cover plate 9 and the main demolding direction PD2 of the C-pillar interior panel 8 is large. Since the first matching surface 11' of the target screw cover plate 9 was optimized in the previous step, structural interference can be avoided, and the initial matching on the C-pillar interior panel 8 can be completed.

[0039] S3, determine the second mating surface on the target component that corresponds to and mates with the first mating surface, that is, make the maximum demolding side F of the target component on the interior panel 8 on the C-pillar that corresponds to and mates with the first mating surface 11', specifically including the following steps.

[0040] S31, determine the matching reference line 10 on the target component, namely the interior trim panel 8 on the C-pillar, based on the parting surface PL of the target screw cover plate 9. (See also...) Figure 10 and Figure 11 The matching method between the target screw cover plate 9 and the interior trim panel 8 on the C-pillar is either overlapping or butt joint. After comparative evaluation, this embodiment adopts... Figure 11 The docking and matching methods are shown.

[0041] S32, see also Figure 12 and Figure 13 Based on the main demolding direction PD1 of the target screw cover and the matching datum line 10, the demolding angle required by the production process is set to 3°, and the demolding side A and the demolding side edge A1 of the target screw cover are determined. The distance from the demolding side edge A1 of the target screw cover to the matching datum line 10 is made 2.5mm as needed.

[0042] S33, based on the main demolding direction PD2 of the target component, namely the interior trim panel 8 on the C-pillar, and the matching baseline 10, the demolding angle required by the production process is set to 7°, and the demolding side B and demolding side edge B1 of the target component are determined. The demolding side edge B1 of the target component and the demolding side edge A1 of the target screw cover are in the same plane.

[0043] S34, obtain a specific point Pt on the demolding side edge B1 of the target component that is farthest from the demolding side edge A1 of the target screw cover. The distance between the point on the demolding side edge B1 of the target component and the demolding side edge A1 of the target screw cover specifically refers to the minimum distance between the point on the demolding side edge B1 of the target component and the demolding side edge A1 of the target screw cover.

[0044] S35, determine plane PS through a specific point Pt and the main demolding direction PD2 of the target part, obtain the intersection line L of plane PS and the demolding side B of the target part, and determine the demolding angle of the maximum demolding side of the target part as 39.997° based on the angle between the intersection line L and the main demolding direction PD2 of the interior panel 8 on the C-pillar. Preferably, the demolding angle of the maximum demolding side of the target part is not less than the angle between the intersection line L and the main demolding direction PD2 of the interior panel 8 on the C-pillar. In this embodiment, the demolding angle of the maximum demolding side F of the target part is set to 41°.

[0045] S36. Based on the main demolding direction PD2 of the C-pillar interior panel 8 and the demolding angle of the maximum demolding side (41°), determine the maximum demolding side of the C-pillar interior panel 8. Then, offset the parting surface PL by 0.5mm towards the target part to obtain the upper limit surface G of the maximum demolding side. Subtract the excess part of the maximum demolding side F from the upper limit surface G to complete the design of the second matching surface 21', i.e., the maximum demolding side of the C-pillar interior panel 8. The intersection line of the maximum demolding side F of the C-pillar interior panel 8 and the upper limit surface G is denoted as g.

[0046] See Figure 14 The image shows the final matching effect of the maximum demolding side F and the outer surface of the interior panel 8 on the C-pillar directly rounded. The shaded area is the exposed maximum demolding side F. It can be seen that although it is symmetrical, it is still uneven. Therefore, it was decided to further optimize or weaken this problem point by adding a transition area H.

[0047] See Figure 15 and Figure 16 Two shapes, h1 and h2, are listed. After comparison and evaluation, shape h2 is adopted in this embodiment.

[0048] Along the main demolding direction PD1 of the target screw cover plate 9, project shape h2 onto the profile of the interior trim panel 8 on the C-pillar, resulting in the following: Figure 11 The projection line h2 shown in the figure.

[0049] See Figure 11 and Figure 16 The transition area H is created using projection lines h2 and upper limit lines g; to achieve a decorative effect, different leather textures are defined on the surface of the transition area H.

[0050] Finally, depending on the needs, steps such as cutting or rounding the corners (R) are selected to complete the data fabrication for the interior trim panel 8 on the C-pillar. The final matching effect is as follows: Figure 16 As shown.

[0051] The screw cover matching structure design method of this invention enables the target screw cover 9 to be used on both the B-pillar interior panel 7 and the C-pillar interior panel 8, solving a series of problems caused by numerous dedicated screw covers for various components and vehicle models, such as 'front-end / mid-end / end-end / after-sales' issues. This allows for the commonality of screw covers across different components and even different vehicle models, thereby reducing new vehicle development costs and lowering manufacturing costs. The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A design method for a screw cover plate matching structure, characterized in that, Includes the following steps: S1, optimize the first matching surface of the target screw cover plate, set the first matching surface as an inwardly inclined slope, and the first matching surface and the edge of the target screw cover plate have a step difference, the step difference is set according to the mold process; S2, perform preliminary matching between the target screw cover plate and the surface of the target component; S3, determine a second mating surface on the target component that corresponds to and mates with the first mating surface; specifically including: S31, Determine the matching reference line on the target component based on the parting surface of the target screw cover plate; S32, based on the main demolding direction of the target screw cover plate and the matching baseline, set the demolding angle and determine the demolding side and demolding side edge of the target screw cover plate; S33, based on the main demolding direction of the target component and the matching baseline, set the demolding angle, determine the demolding side and demolding side edge of the target component, wherein the demolding side edge of the target component and the demolding side edge of the target screw cover plate are in the same plane; S34, obtain the specific point on the demolding side edge of the target part that is furthest from the demolding side edge of the target screw cover plate; S35, determine a plane through a specific point and the main demolding direction of the target part, obtain the intersection line of the plane and the demolding side of the target part, and determine the demolding angle of the maximum demolding side of the target part based on the angle between the intersection line and the main demolding direction; S36. The design of the second matching surface is completed based on the main demolding direction of the target part and the demolding angle of the maximum demolding side. Specifically, the maximum demolding side of the target part is determined based on the main demolding direction of the target part and the demolding angle of the maximum demolding side. Then, the parting surface is offset by 0.5mm towards the target part to obtain the upper limit surface of the maximum demolding side. The excess part of the maximum demolding side is subtracted from the upper limit surface to complete the design of the second matching surface.

2. The design method of the screw cover plate matching structure according to claim 1, characterized in that: The demolding angle of the maximum demolding side of the target component in S36 is not less than the angle between the intersection line and the main demolding direction.

3. The design method of the screw cover plate matching structure according to claim 1, characterized in that: The tilt angle of the first matching surface is set as large as possible while meeting the requirements of structural performance and manufacturing process.

4. The design method of the screw cover plate matching structure according to claim 1, characterized in that: During the initial matching process in S2, the matching method of overlapping or docking is selected based on the specific application environment and actual needs.

5. The design method of the screw cover plate matching structure according to claim 1, characterized in that: It also includes S4, which sets a transition area between the outer surface of the target component and the second mating surface.

6. The design method of the screw cover plate matching structure according to claim 5, characterized in that: The shape of the transition area is arranged reasonably according to the appearance quality requirements of the target component.

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