Vehicle pillar trim panel and method of forming optimization thereof

Abstract

The application discloses a vehicle upright column upper trim plate and a forming optimization method thereof, relates to the technical field of vehicle parts, and can solve the problem that an injection-molded covering part is easily broken in a low-pressure injection molding process. The vehicle upright column upper trim plate is formed through low-pressure injection molding and comprises a base and a covering part. The base is provided with a first profile, a second profile and a transition structure. The first profile is assembled in a visible area in a vehicle, and the second profile is assembled in a non-visible area in the vehicle. The transition structure is fixedly connected between the second profile and the first profile. The covering part covers the same side surface of the first profile, the transition structure and the second profile. The transition structure comprises a first plate, a second plate and a third plate which are smoothly connected in sequence. In the direction towards the second plate, the thickness of the first plate and the thickness of the third plate are gradually reduced, and the thickness of the second plate is smaller than the minimum value of the thickness of the first plate and the third plate. The vehicle upright column upper trim plate is assembled on a vehicle body sheet metal.

Description

Technical Field

[0001] This application relates to the field of vehicle component technology, and in particular to a trim panel on a vehicle pillar and its molding optimization method. Background Technology

[0002] The pillar trim panel, located at the top of the vehicle pillar, is an interior component of the car. It serves not only a decorative purpose but also provides occupant protection. After successful injection molding, it is typically fixed to the vehicle body sheet metal using snap-fit ​​components. Low-pressure injection molding allows for the covering of molded parts with fabric or suede to create various grades of injection molded parts. It can produce a part in just one or two minutes, offering high production efficiency and good consistency, making it increasingly popular in vehicle applications.

[0003] Vehicle pillar trim panels typically have a large profile in the demolding direction, meaning the fabric of the stretched injection molded part will be very thin. This can easily lead to excessive stretching of the injection molded part. Furthermore, if the profile fluctuates drastically, for example, if the distance between the protruding flange structure and the profile fluctuates greatly, or if the wall thickness of the protruding structure is large, it will further increase the possibility of the plastic melt puncturing the injection molded part during low-pressure injection molding. Summary of the Invention

[0004] In view of this, the present application provides a vehicle pillar trim panel and its molding optimization method, which has the advantage that the injection-molded covering part is not easily punctured during the low-pressure injection molding process.

[0005] In a first aspect, embodiments of this application provide a vehicle pillar trim panel, which is formed by low-pressure injection molding. The vehicle pillar trim panel includes a base and a covering. The base has a first surface, a second surface, and a transition structure. The first surface is fitted into the visible area inside the vehicle and is parallel to a first direction. The second surface is fitted into the invisible area inside the vehicle and is perpendicular to the first direction. The transition structure is fixedly connected between the second surface and the first surface. The covering is formed by low-pressure injection molding and covers the same side surface of the first surface, the transition structure, and the second surface. The transition structure includes a first plate, a second plate, and a third plate that are smoothly connected end to end. The first plate is smoothly connected to the first surface, and the third plate is fixedly connected to the side wall of the second surface facing the covering. In the direction facing the second plate, the thickness of the first plate and the thickness of the second plate are gradually reduced, and the thickness of the second plate is less than the minimum thickness of the first plate and the third plate. The first direction is the demolding direction of the vehicle pillar trim panel.

[0006] Specifically, the first profile on the base of the vehicle pillar trim panel is mounted within the visible area inside the vehicle, and this first profile is parallel to the demolding direction. Since the first profile is mounted within the visible area, the covering material on its outer surface must not be punctured. Here, the outer surface contour of the first profile, as a structure within the visible area, generally cannot be altered. The second profile, perpendicular to the first profile, is mounted within the invisible area inside the vehicle. Generally, the second profile provides mounting bases for vehicle components and connection structures for attaching to the vehicle body to assemble the vehicle pillar trim panel onto the upper body. During low-pressure injection molding, a covering material of similar size to the second profile is typically stretched and covered over the entire first profile, i.e., the entire surface of the vehicle pillar trim panel facing inwards towards the vehicle body. In this case, the stretched covering material is relatively thin, making it easy for the molten plastic to puncture it. If any puncture occurs on the first profile within the visible area, the entire vehicle pillar trim panel will be a defective product. Since the first surface is perpendicular to the second surface, meaning the first and second surfaces are not on the same plane, connecting the first and second surfaces into a whole is a necessary process. At this point, the transition structure connecting the first and second surfaces naturally becomes the most vulnerable point for the covering. Therefore, the transition structure needs to be optimized to solve the problem of the covering being easily penetrated at the transition connection.

[0007] The transition structure comprises a first plate, a second plate, and a third plate that are smoothly connected end-to-end. Specifically, the first plate connects to the second plate at their closest points, while the second plate connects to one end of the third plate at its furthest point. Correspondingly, the first plate connects to the first surface at its furthest point, and the third plate connects to the second surface at its furthest point, thus achieving a smooth transition between the first and second surfaces. This smooth connection between the first plate and the first surface avoids the breakdown problem caused by structures protruding from the first surface. Furthermore, the thickness of both the first and third plates gradually decreases towards the second plate, making the transition structure a gradually thickening structure. This reduces the breakdown force of the molten plastic on the encapsulated part during low-pressure injection molding, and also shortens the cooling time of the molten plastic, thereby reducing the possibility of molten plastic breaking through the encapsulated part at the transition structure. Furthermore, the thickness of the second plate is less than the minimum thickness of the first and third plates. This further reduces the possibility of the cladding being punctured at that location by reducing the wall thickness. The specific thickness of the second plate is not limited, and can be, for example, 1.5mm, 1.2mm, 1mm, etc. However, to ensure the strength of the transition structure, the thickness of the second plate cannot be reduced indiscriminately. For example, the thickness of the second plate can preferably be reduced to 1mm, which minimizes the puncture force at that location while maintaining sufficient strength.

[0008] It should be noted that the surface of the transition structure facing the covering should be as smooth as possible. That is, the connection between the first plate and the first surface, the connection between the first plate and the second plate, and the connection between the third plate and the second surface should all be smoothly transitioned to avoid the covering being easily penetrated due to the presence of sharp objects or large undulating surfaces. In addition, the cross-sectional shape of the transition structure in the plane perpendicular to the first direction is not limited. For example, the cross-sectional shape can be Z-shaped or U-shaped, wherein the opening of the Z-shaped or U-shaped structure faces the side away from the covering.

[0009] In one possible implementation of this application, the first plate and the first profile are located on the same plane and are integrally formed; the third plate is parallel to the first direction, the second plate is flat to the second profile, and the transition structure has a Z-shaped cross-section parallel to the first direction. Here, the integral forming design of the first plate and the first profile increases the overall integrity between the transition structure and the first profile and facilitates a smooth transition connection. The Z-shaped cross-section design of the transition structure perpendicular to the first direction is simpler and easier to implement than a U-shaped cross-section. For example, the transition structure can be directly designed as a Z-shaped flange structure on the first or second profile.

[0010] In one possible implementation of this application, a flange structure is provided on the side wall of the second profile facing the second plate. The flange structure has a first side plate and a second side plate. The first end of the first side plate is fixedly connected to the first profile and is inclined upward away from the second profile. The first end of the second side plate is smoothly connected to the second end of the first side plate, and the second end of the second side plate is fixedly connected to the third plate and is inclined downward toward the second profile. The first and second side plates can be designed to have a small angle with the second profile, making the flange structure as gentle as possible. This reduces the undulation of the flange structure facing the covering, for example, making the flange structure approximately a smooth slope. Therefore, compared to a more undulating Z-shaped flange structure, the tensile length of the covering at this flange structure can be reduced, thereby reducing the possibility of puncture at this location.

[0011] In one possible implementation of this application, the second profile further includes a first mounting structure and a lifting structure. The first mounting structure includes a third side plate and a fourth side plate connected to each other, both of which are inclined upwards away from the second profile. The cross-sectional shape of the first mounting structure parallel to the first profile is V-shaped. The lifting structure is fixed between the first mounting structure and the second profile to raise the first mounting structure. Compared to a design without a lifting structure, the design with a lifting structure effectively raises the bottom of the V-shaped first mounting structure, reducing the profile height difference and further reducing the tensile length of the covering at that location, thereby reducing the possibility of the covering being punctured.

[0012] In one possible implementation of this application, the second profile near the fourth side plate also has a second mounting panel. One end of the second mounting panel is fixedly connected to the second profile, and the second mounting panel is inclined upward away from the second profile. The distance between the other end of the second mounting panel and the second profile is greater than or equal to the distance between the free end of the fourth side plate and the second profile. Here, since the fourth side plate is lifted under the action of the lifting structure to reduce the tensile length of the covering at that location, designing the distance between the other end of the second mounting panel and the second profile to be greater than or equal to the distance between the free end of the fourth side plate and the second profile is equivalent to increasing the profile height of the second mounting panel. Here, profile height can refer to the maximum height of the second mounting panel from the second profile.

[0013] In one possible implementation of this application, the second surface also has a third mounting structure. The third mounting structure includes at least a first mounting base and a second mounting base. The first and second mounting bases are respectively provided with a first mounting hole and a second mounting hole for fastening connection with the rear trim piece. The first and second mounting bases are fixedly connected. The side of the first mounting base with the first mounting hole is the first surface, facing the cover piece. The side of the second mounting base with the second mounting hole is the second surface, facing the cover piece. The first and second surfaces are on the same plane. This reduces the height difference between the first and second mounting bases. Furthermore, each mounting base has a side facing the cover piece, i.e., the first and second surfaces are on the same plane. In addition to reducing the height difference between the two mounting bases, the mounting surfaces of the two mounting bases also face the same direction, thereby making the surface of the cover piece transition smoothly at that point and reducing the height difference between the two mounting surfaces. This significantly reduces the tensile length of the cover piece, thereby reducing the possibility of the surface being punctured by the cover piece.

[0014] In one possible implementation of this application, a reinforcing rib is provided on the second surface. One end of the reinforcing rib is fixedly connected to a side wall of the first surface near the third plate, and the other end is fixedly connected to a side wall of the second surface away from the third plate. The thickness of the reinforcing rib is less than or equal to the thickness of the second plate. The distance from the end of the reinforcing rib opposite to the second surface to the second surface is less than or equal to one-quarter of the length of the first surface in the first direction. The side wall of the first surface near the third plate is the side of the first surface that is opposite to the first surface in the visible area. When the reinforcing rib is too high in the demolding direction, the molten plastic is not easily filled. In this case, the injection pressure must be increased to fill the mold. However, with increased injection pressure, the melt pressure at the transition structure is greater, and the molten plastic pressure on the cover is also greater, making it easier for the cover to be punctured at that point. Therefore, the height and wall thickness of the reinforcing rib should be reduced. The thickness of the reinforcing rib should be less than or equal to the thickness of the second plate, and the distance from the end of the reinforcing rib opposite to the second mold surface to the second mold surface should be less than or equal to one-quarter of the length of the first mold surface in the first direction. This design is equivalent to reducing the height and wall thickness of the reinforcing rib in the demolding direction, so that the injection process is at a lower pressure, making it less likely for the cover to be punctured at that point.

[0015] Secondly, this application also provides a method for optimizing the forming of a vehicle pillar trim panel. Using a vehicle pillar trim panel in any of the first directions mentioned above, the method includes gradually reducing the thickness of the first panel and the thickness of the second panel in the direction toward the second panel, while reducing the thickness of the second panel to a preset thickness; wherein the preset thickness is less than the minimum of the thicknesses of the first panel and the third panel.

[0016] In this application, the thicknesses of both the first and third plates are gradually reduced towards the second plate, resulting in faster heat dissipation and significantly shortening the cooling time of the molten plastic. This reduces the risk of the molten plastic penetrating the casing at the transition structure. Furthermore, considering that the second plate is the most vulnerable point for the casing, its preset thickness is less than the minimum thickness of the first and third plates. This maximizes heat dissipation at the second plate during low-pressure injection molding, reducing its cooling time and minimizing the possibility of casing penetration. The specific thickness of the second plate is not limited, and can be 1.5mm, 1.2mm, 1mm, etc. However, to maintain the strength of the transition structure, the thickness of the second plate cannot be arbitrarily reduced. For example, the thickness of the second plate can preferably be reduced to 1mm, minimizing the penetration force while maintaining sufficient strength.

[0017] In one possible implementation of this application, a flange structure is provided on the side wall of the second profile facing the second plate. The flange structure has a first side plate and a second side plate. The first end of the first side plate is fixedly connected to the first profile, and the second end of the first side plate is smoothly connected to the first end of the second side plate. The second end of the second side plate is fixedly connected to the third plate. After the step of gradually reducing the thickness of the first plate and the thickness of the second plate in the direction towards the second plate, and simultaneously reducing the thickness of the second plate to a preset thickness, the forming optimization method further includes: tilting the first end of the first side plate upward away from the second profile and forming a first preset angle with the second profile; and tilting the second end of the second side plate downward toward the second profile and forming a second preset angle with the second profile; wherein the first preset angle is equal to the second preset angle.

[0018] In one possible implementation of this application, the second surface further includes a first mounting structure and a lifting structure. The first mounting structure has a V-shaped cross-section parallel to the first surface. The lifting structure is fixed between the first mounting structure and the second surface. There is a height difference between the side wall of the lifting structure facing the first mounting structure and the second surface. After the step of gradually reducing the thickness of the first plate and the thickness of the second plate in the direction facing the second plate, and simultaneously reducing the thickness of the second plate to a preset thickness, the forming optimization method further includes: adjusting the height difference to a preset height difference, and simultaneously reducing the depth of the V-groove of the first mounting structure. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a vehicle pillar trim panel provided in an embodiment of this application;

[0020] Figure 2 A cross-sectional structural diagram of a vehicle pillar trim panel provided in an embodiment of this application;

[0021] Figure 3 This is a partial schematic diagram of a low-pressure injection molding puncture in a vehicle pillar trim panel, provided as an embodiment of this application.

[0022] Figure 4 This is a structural schematic diagram of the non-visible area on the back of the first profile of a vehicle pillar trim panel, provided in an embodiment of this application.

[0023] Figure 5 A structural schematic diagram of an interior panel mounting bracket and reinforcing ribs in a vehicle pillar trim panel provided in this application embodiment;

[0024] Figure 6 Provided for the embodiments of this application Figure 5 A magnified view of a portion of point C in the middle;

[0025] Figure 7A partial schematic diagram of an optimized front flange structure, an optimized first mounting structure, and an optimized second mounting panel in a vehicle pillar trim panel provided in this application embodiment;

[0026] Figure 8 This is a schematic diagram of the cross-sectional structure of an optimized front flange structure in a vehicle pillar trim panel provided in an embodiment of this application;

[0027] Figure 9 A partial schematic diagram of an optimized flange structure, a first mounting structure, and a second mounting panel in a vehicle pillar trim panel provided in an embodiment of this application;

[0028] Figure 10 This is a schematic diagram of a second mounting structure in a vehicle pillar trim panel before optimization, provided in an embodiment of this application.

[0029] Figure 11 A schematic diagram of an optimized second mounting structure in a vehicle pillar trim panel provided in an embodiment of this application;

[0030] Figure 12 A schematic diagram of a low-pressure injection molded product for a vehicle pillar trim panel provided in this application embodiment;

[0031] Figure 13 One of the flowcharts for an optimized molding method of a vehicle pillar trim panel provided in an embodiment of this application;

[0032] Figure 14 A second flowchart illustrating an optimized method for forming a trim panel on a vehicle pillar, provided as an embodiment of this application;

[0033] Figure 15 This is the third flowchart of a method for optimizing the forming of a trim panel on a vehicle pillar, as provided in an embodiment of this application.

[0034] Figure label:

[0035] 100 - Base; 1 - First profile; 2 - Second profile; 21 - Flanged structure; 211 - First side panel; 212 - Second side panel; 22 - First mounting structure; 221 - Third side panel; 222 - Fourth side panel; 23 - Second mounting panel; 24 - Second mounting structure; 241 - First mounting base; 242 - Second mounting base; 25 - Reinforcing rib; 3 - Transition structure; 31 - First plate; 32 - Second plate; 33 - Third plate; 5 - Interior panel mounting bracket; 61 - Flanged structure before optimization; 62 - First mounting structure before optimization; 63 - Second mounting panel before optimization. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the specific technical solutions of this application will be further described in detail below with reference to the accompanying drawings of the embodiments of this application. The following embodiments are used to illustrate this application, but are not intended to limit the scope of this application.

[0037] In the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0038] Furthermore, in the embodiments of this application, directional terms such as "upper," "lower," "left," and "right" are defined relative to the positions in which the components are schematically placed in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the position of the components in the accompanying drawings.

[0039] In the embodiments of this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0040] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0041] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0042] In the design of a car's body structure, there are A-pillars, B-pillars, vehicle pillars, and sometimes D-pillars. These pillars support the entire vehicle body, and the pillar guards connected to these pillars absorb impacts, effectively protecting the occupants and also providing appropriate interior decoration. For example, pillar trim panels are located at the upper part of the pillars and are usually fixed to the body sheet metal near the rear door or on the corner window. They are interior components that not only serve a decorative purpose but also provide occupant protection.

[0043] This application provides a vehicle. It should be noted that the vehicle in this application can refer to large vehicles, small vehicles, special-purpose vehicles, etc. For example, according to vehicle type, the vehicle in this application embodiment can be a sedan, an off-road vehicle, a multi-purpose vehicle (MPV), or other types of vehicles. The vehicle provided in this application includes body sheet metal and vehicle pillar trim panels, with the pillar trim panels mounted on the body sheet metal. The vehicle in this application has the advantage that the injection-molded parts are less prone to puncture during low-pressure injection molding.

[0044] Currently, the molding process for vehicle pillar guards is mostly based on high-pressure injection molding, typically involving textured injection molding or bonding the molded material with a covering. This often results in a strong plastic feel, a long processing cycle, and poor consistency. Low-pressure injection molding, on the other hand, uses lower pressure and speed, ensuring stable flow of the molten plastic. Once the mold cavity is filled, uniform shrinkage can be achieved without holding pressure. For example, the outer layer (such as soft fabric, non-woven fabric, suede, etc.) can be pre-placed in the mold at very low injection pressure. Then, using the thrust of the screw, the pre-plasticized molten plastic is injected into the closed mold cavity. After curing and shaping, the finished product is obtained. Because it allows for the covering of fabrics or suede onto the injection molded parts, it can process injection molded parts of various grades. A part can be produced in just one or two minutes, offering high production efficiency and good consistency. Therefore, low-pressure injection molding has been widely used in the production of automotive door panels, vehicle pillar guards, and wraparound guards.

[0045] Vehicle pillar trim panels typically have a large surface area in the demolding direction, which can easily lead to excessive stretching of the injection-molded overmolded part. This means the stretched surface of the injection-molded part will be very thin. Furthermore, if the surface area fluctuates significantly—for example, if the distance between the protruding flange structure and the surface varies greatly, or if the wall thickness of the protruding structure is large—the structure's heat dissipation performance will be poor, resulting in a long cooling time. This further increases the possibility of the molten plastic puncturing the injection-molded overmolded part during low-pressure injection molding. For example, punctures are prone to occur at sharp corners. At sharp corners, the parting surface clearance can allow molten plastic to penetrate through the gap when the material flow or speed increases, causing puncture problems. Larger wall thicknesses also increase the likelihood of punctures.

[0046] Therefore, this application provides a trim panel on a vehicle pillar, referring to... Figure 1 , Figure 2 and Figure 3 The vehicle pillar trim panel is formed by low-pressure injection molding. The vehicle pillar trim panel includes a base 100 and a covering. The base 100 has a first surface 1, a second surface 2, and a transition structure 3. The base 100 has a first surface 1 that is mounted in the visible area inside the vehicle, and the first surface 1 is parallel to a first direction; a second surface 2 is mounted in the invisible area inside the vehicle, and the second surface 2 is perpendicular to the first direction; a transition structure 3 is fixedly connected between the second surface 2 and the first surface 1; a covering is coated onto the same side surface of the first surface 1, the transition structure 3, and the second surface 2 by low-pressure injection molding; the transition structure 3 includes a first plate 31, a second plate 32, and a third plate 33 that are smoothly connected end to end, the first plate 31 is smoothly connected to the first surface 1, and the third plate 33 is fixedly connected to the side wall of the second surface 2 facing the covering; in the direction facing the second plate 32, the thickness of the first plate 31 and the thickness of the third plate 32 are gradually reduced, and the thickness of the second plate 32 is less than the minimum value of the thickness of the first plate 31 and the third plate 32; wherein, the first direction is the demolding direction of the trim panel on the vehicle pillar.

[0047] Typically, the trim panel on a vehicle pillar consists of a base 100 made of a high-hardness material, a shaped surface surrounding the base 100, and a skin layer outside the shaped surface. Different external contour shapes can be obtained by optimizing the surface structure of the visible part on the base 100. Specifically, the base 100 has a first shaped surface 1 that is fitted into the visible area inside the vehicle, and the first shaped surface 1 is parallel to the demolding direction. Since the first shaped surface 1 is fitted into the visible area inside the vehicle, the covering material on the outer surface of the first shaped surface 1 cannot be punctured. Here, the outer surface contour of the first shaped surface 1, as a surface structure within the visible area, generally cannot be modified. The second shaped surface 2, perpendicular to the first shaped surface 1, is fitted into the invisible area inside the vehicle. Generally, mounting bases for vehicle components and connecting structures for fitting with the vehicle body are set on the second shaped surface 2 to assemble the interior trim panel on the vehicle pillar to the upper body. During low-pressure injection molding, a covering part of similar size to the second molded surface 2 is typically stretched and covered over the entire first molded surface 1, i.e., the entire surface of the vehicle pillar trim panel facing inwards towards the vehicle body. In this case, the stretched covering part is relatively thin, making it easy for the molten plastic to puncture it. If any part of the first molded surface 1, which is within the visible area, is punctured, the entire vehicle pillar trim panel will be a defective product. Since the first molded surface 1 is perpendicular to the second molded surface 2, meaning they are not on the same plane, connecting them into a single unit is necessary. Therefore, the transition structure 3 connecting the first and second molded surfaces 1 and 2 naturally becomes the most vulnerable point for puncture of the covering part. (Refer to...) Figure 3 , can Figure 3 It can be seen that the transition structure 3 is in a breakdown state. Therefore, the transition structure 3 needs to be optimized to solve the problem of easy breakdown of the covering at the transition connection.

[0048] Reference Figure 2 The transition structure 3 includes a first plate 31, a second plate 32, and a third plate 33 that are smoothly connected end to end. Specifically, the smooth connection means that the two ends of the first plate 31 and the second plate 32 that are close to each other are connected, and the other end of the second plate 32 that is away from the first plate 31 is connected to one end of the third plate 33. Correspondingly, the end of the first plate 31 that is away from the second plate 32 is connected to the first surface 1, and the end of the third plate 33 that is away from the second plate 32 is connected to the second surface 2, so as to realize the transition connection between the first surface 1 and the second surface 2. Here, the smooth connection between the first plate 31 and the first surface 1 can avoid the penetration problem caused by the structure protruding from the first surface 1 between the first plate 31 and the first surface 1. Typically, the cooling time of low-pressure injection molded parts is proportional to the square of the wall thickness at the thickest point. Therefore, thicker parts require longer cooling times. During low-pressure injection molding, shrinkage is inevitable as cooling occurs, with thicker walls resulting in greater shrinkage (conversely, thinner walls shrink less). Longer cooling times and greater shrinkage lead to a greater puncture force from the molten plastic on the encapsulated part, significantly increasing the likelihood of the encapsulated part being punctured during the low-pressure injection molding process. The embodiments of this application refer to... Figure 2 In the direction towards the second plate 32, the thicknesses of both the first plate 31 and the third plate 32 gradually decrease, meaning the transition structure 3 is designed with a gradually thinning wall thickness. This improves the heat transfer efficiency at the transition structure 3, significantly reducing the cooling time of the plastic melt and thus reducing the possibility of the covering being punctured by the plastic melt at the transition structure 3. Furthermore, the thickness of the second plate 32 is less than the minimum of the thicknesses of the first plate 31 and the third plate 32. This further reduces the possibility of the covering being punctured at that location due to the reduced wall thickness. The specific thickness of the second plate 32 is not limited, and can be, for example, 1.5mm, 1.2mm, 1mm, etc. However, to maintain the strength of the transition structure 3, the thickness of the second plate 32 cannot be reduced indiscriminately. For example, the thickness of the second plate 32 can preferably be reduced to 1mm, minimizing the puncture force at that location while maintaining sufficient strength.

[0049] It should be noted that the surface of the transition structure 3 facing the covering should be as smooth as possible. That is, the connection between the first plate 31 and the first surface 1, the connection between the first plate 31 and the second plate 32, and the connection between the third plate 33 and the second surface 2 should all be smoothly transitioned to ensure a smooth transition of the product surface and minimize the possibility that the covering may be easily punctured due to the presence of sharp objects or large undulating surfaces. In addition, the cross-sectional shape of the transition structure 3 on the plane perpendicular to the first direction is not limited. For example, the cross-sectional shape can be Z-shaped or U-shaped, wherein the opening of the Z-shaped or U-shaped opening faces away from the covering.

[0050] Furthermore, the surface area facing the visible zone along the first direction is relatively large, while the normal stretch rate of fabric is around 20%, and that of suede is around 40%. This easily exceeds the fabric's stretch ratio limit. Since the visible zone of the first surface 1 in the demolding direction cannot be altered, the only option is to adjust the surface structure within the invisible zone as much as possible to reduce the possibility of the plastic melt puncturing the encapsulated part. Among these, since the second surface 2 is an invisible zone, even if puncture occurs, it will not be visible when installed on the vehicle body and will not affect product quality. Therefore, the surface portion perpendicular to the demolding direction, i.e., the second surface 2 portion, mainly reduces the stretch rate of the fabric or suede through structural design.

[0051] In some embodiments of this application, the covering (not shown in the figures) includes a base layer and a skin layer covering the base layer. The specific materials and structures of the base layer and skin layer are not limited; for example, the base layer may be a knitted fabric mesh layer, and the skin layer may be made of polyvinyl chloride (PVC), or the skin layer may be suede, etc. Unless otherwise specified in the embodiments of this application, the skin layer of the covering is suede.

[0052] For example, refer to Figure 1 , Figure 2 and Figure 3 The first plate 31 and the first surface 1 are located on the same plane and are integrally formed; the third plate 33 is parallel to the first direction, the second plate 32 is flat to the second surface 2, and the transition structure 3 has a Z-shaped cross-section parallel to the first direction. Here, the design of the first plate 31 being integrally formed with the first surface 1 increases the integrity between the transition structure 3 and the first surface 1 and facilitates a smooth transition connection. (Refer to...) Figure 2 For example, the transition structure 3 can be designed as a Z-shaped flange structure 21 on the first surface 1 or the second surface 2. In the Z-shaped flange transition structure 3, the area shown by the second plate 32 is the thinnest. Since the cooling time of the part in the low-pressure injection molding process of the trim panel on the vehicle pillar is proportional to the square of the wall thickness at the thickest position of the part, the thinner part wall has higher heat dissipation efficiency and shorter cooling time, thereby reducing the possibility of the covering part being punctured at the thinner transition structure 3.

[0053] In some embodiments, refer to Figure 9 The second profile 2 has a flange structure 21 on one side wall facing the second plate 32. The flange structure 21 has a first side plate 211 and a second side plate 212. The first end of the first side plate 211 is fixedly connected to the first profile 1 and is inclined upward away from the first profile 1. The second end of the first side plate 211 is smoothly connected to the first end of the second side plate 212 and is inclined downward away from the first side plate 211. The second end of the second side plate 212 is fixedly connected to the third plate 33. Here, the first side plate 211 and the second side plate 212 can be designed to have a small included angle with the second profile 2, so that the flange structure 21 is as gentle as possible, thereby reducing the undulation of the side of the flange structure 21 facing the covering. For example, the flange structure 21 is approximately a smooth slope. (Referring to...) Figure 7 and Figure 8 As shown, compared to the more volatile Z-shaped optimized flange structure 61, the tensile length of the covering at the flange structure 21 can be reduced, thereby reducing the possibility of puncture at this location. Specifically, referring to... Figure 8 , Figure 8 A cross-sectional view of the optimized front flange structure 61 in the upper trim panel of the vehicle pillar, from... Figure 8 In the image, it can be clearly seen that the unflanged structure 61 before optimization has a Z-shaped structure. The Z-shaped structure of the flange will increase the fluctuation of the surface, that is, the surface smoothness is poor, which will greatly increase the stretching length of the covering part, and thus increase the possibility of the covering part being punctured.

[0054] Reference Figure 9 The second surface 2 also includes a first mounting structure 22 and a lifting structure (not shown in the figure). The first mounting structure 22 includes a third side plate 221 and a fourth side plate 222 connected to each other. Both the third side plate 221 and the fourth side plate 222 are inclined upward away from the second surface 2. The cross-sectional shape of the first mounting structure 22 parallel to the first surface 1 is V-shaped. The lifting structure is fixed between the first mounting structure 22 and the second surface 2 to raise the first mounting structure 22. For example, see reference... Figure 7 Regarding the first mounting structure 62 before optimization, the design includes a lifting structure, which is equivalent to raising the bottom of the V-shaped first mounting structure 22, reducing the surface drop, and thus further reducing the tensile length of the covering at that location, thereby reducing the possibility of the covering being punctured. For example, the planes where the third side plate 221 and the fourth side plate 222 are located are both made to have a small angle with the second surface 2, that is, the V-shaped groove is designed to be a shallow V-shaped groove. This can minimize the tensile length of the covering at that location, and minimize the possibility of the covering being punctured.

[0055] Continue, refer to Figure 9 The second profile 2, near the fourth side plate 222, also has a second mounting panel 23. One end of the second mounting panel 23 is fixedly connected to the second profile 2, and the second mounting panel 23 is inclined upward away from the second profile 2. The distance between the other end of the second mounting panel 23 and the second profile 2 is greater than or equal to the distance between the free end of the fourth side plate 222 and the second profile 2. Here, since the fourth side plate 222 is lifted under the action of the lifting structure to reduce the tensile length of the covering at that location, designing the distance between the other end of the second mounting panel 23 and the second profile 2 to be greater than or equal to the distance between the free end of the fourth side plate 222 and the second profile 2 is equivalent to... Figure 7 Before optimization, the second mounting panel 63 increased the profile height of the second mounting panel 23. Here, profile height can refer to the maximum height of the second mounting panel 23 from the second profile 2.

[0056] In some embodiments, refer to Figure 10 Area B is the third installation structure 24 before optimization. Figure 11 The middle D area is the optimized third mounting structure 24, which is disposed on the second surface 2. The third mounting structure 24 includes at least a first mounting base 241 and a second mounting base 242. The first mounting base 241 and the second mounting base 242 are respectively provided with a first mounting hole and a second mounting hole for fastening connection with the rear trim piece. The first mounting base 241 and the second mounting base 242 are fixedly connected. The side of the first mounting base 241 with the first mounting hole is the first side, which faces the cover piece. The side of the second mounting base 242 with the second mounting hole is the second side, which faces the cover piece. Figure 11 In the optimized third mounting structure 24, the first and second surfaces are on the same plane. This reduces the height difference between the first mounting base 241 and the second mounting base 242. Furthermore, each mounting base has one side facing the covering, meaning the first and second surfaces are on the same plane. In addition to reducing the height difference between the two mounting bases, the mounting surfaces on the two bases also face the same direction, resulting in a smooth transition of the covering surface at that location. This also reduces the height difference between the two mounting surfaces, significantly reducing the tensile length of the covering and lowering the possibility of the covering surface being punctured at that location.

[0057] For example, refer to Figure 10 , Figure 10 This is a schematic diagram of the second mounting structure in the vehicle pillar trim panel before optimization. Figure 10 The holes in area B are the mounting holes between the upper trim panel of the vehicle pillar and the rear trim piece of the upper trim panel of the vehicle pillar. Figure 10As shown in area B, the elevation difference between the surfaces is very large, and the surfaces face different directions. By optimizing the surface structure at this location, a reference design can be implemented. Figure 11 The holes in area D are the first and second mounting holes between the upper trim panel of the vehicle pillar and the rear trim piece of the upper trim panel of the vehicle pillar. Figure 11 As shown in region D, the height difference between the first surface on the first mounting base 241 and the second surface on the second mounting base 242 is relatively small compared to... Figure 10 It is very small, which makes the surface transition smoothly and reduces the height difference between surfaces, greatly reducing the stretch length of the fabric or suede.

[0058] Reference Figure 4 and Figure 5 The second surface 2 is provided with a reinforcing rib 25. One end of the reinforcing rib 25 is fixedly connected to the side wall of the first surface 1 near the third plate 33, and the other end is fixedly connected to the side wall of the second surface 2 away from the third plate 33. The thickness of the reinforcing rib 25 is less than or equal to the thickness of the second plate 32. The distance from the end of the reinforcing rib 25 opposite to the second surface 2 to the second surface 2 is less than or equal to one-quarter of the length of the first surface 1 in the first direction. The side wall of the first surface 1 near the third plate 33 is the side of the first surface 1 that is opposite to the first surface 1 in the visible area. The side wall of the second surface 2 away from the third plate 33 is the side wall of the second surface 2 that is opposite to the third plate 33 and has a flange structure 21. When the height of the reinforcing rib 25 in the demolding direction is too high, the plastic melt is not easy to fill the mold. In this case, in order to fill the mold, the injection pressure must be increased. However, after increasing the injection pressure, the melt pressure at the transition structure 3 is greater, and the puncture pressure of the plastic melt on the cover is also greater, making it easier to cause the cover to puncture at that point. Therefore, the height and wall thickness of the reinforcing rib 25 should be reduced. The thickness of the reinforcing rib 25 should be less than or equal to the thickness of the second plate 32. The distance from the end of the reinforcing rib 25 opposite to the second mold surface 2 to the second mold surface 2 should be less than or equal to one-quarter of the length of the first mold surface 1 in the first direction. This design is equivalent to reducing the height of the reinforcing rib 25 in the demolding direction and reducing the wall thickness, so that the injection process is at a lower pressure, and thus it is not easy to puncture the cover at that point.

[0059] Additionally, it should be noted that, referring to Figure 4 of Figure 5 Based on the reduction in height and wall thickness of the reinforcing ribs 25 in the demolding direction, the number of reinforcing ribs 25 at the Z-shaped transition structure 3 can also be reduced to avoid increasing the possibility of the covered part being punctured due to the higher injection pressure at this location. It should be noted that... Figure 4 and Figure 5The diagram in the middle shows a relatively large number of reinforcing ribs 25. In the embodiments of this application, it can be shown that... Figure 4 and Figure 5 The number of reinforcing ribs 25 is reduced to two or four.

[0060] Reference Figure 5 and Figure 6 , Figure 5 The diagram shows the structure of the vehicle pillar trim panel, including the interior panel mounting bracket 5 and reinforcing rib 25. The first surface 1, the side wall facing away from the visible area, is a smooth side wall. Figure 5 The interior panel mounting bracket 5 on the pre-reserved vehicle pillar trim panel is removed, referring to... Figure 6 Because the interior panel mounting bracket 5 is designed to be quite high and difficult to mold, this application will eliminate these three interior panel mounting brackets 5, which can effectively reduce the injection molding pressure. In particular, when the molding material is acrylonitrile butadiene styrene copolymer (ABS), which is a thermoplastic polymer structural material with high strength, good toughness and easy processing, the effect of reducing the injection molding pressure is very obvious.

[0061] This application also provides an optimized method for forming a trim panel on a vehicle pillar, referring to... Figure 13 The molding optimization method includes the following steps:

[0062] Step S100: The thickness of the first plate and the thickness of the second plate are gradually reduced in the direction toward the second plate, while the thickness of the second plate is reduced to a preset thickness.

[0063] The preset thickness is less than the minimum thickness of the first and third plates;

[0064] Specifically, in step S100, the thickness of both the first plate 31 and the third plate 33 is gradually reduced in the direction towards the second plate 32. This thinning of the walls of the first plate 31 and the second plate 32 results in faster heat dissipation and significantly shortens the cooling time of the molten plastic, thereby reducing the risk of the molten plastic penetrating the covering at the three transition structures. The specific value of the preset thickness can be obtained through multiple low-pressure injection molding tests on the vehicle pillar trim panel. For example, the thickness of the second plate 32 can be reduced to 1.5mm, 1.2mm, 1mm, etc. Furthermore, considering that the second plate 32 is the most vulnerable location for penetration, the preset thickness is further reduced to the minimum of the thicknesses of the first and third plates, meaning the second plate 32 has the thinnest wall thickness. This maximizes the heat dissipation of the molten plastic at the second plate 32 during low-pressure injection molding, reducing the cooling time and minimizing the possibility of penetration.

[0065] Additionally, refer to Figure 9 The second profile 2 has a flange structure 21 on one side wall facing the second plate 32. The flange structure 21 has a first side plate 211 and a second side plate 212. The first end of the first side plate 211 is fixedly connected to the first profile 1, and the second end of the first side plate 211 is smoothly connected to the first end of the second side plate 212. The second end of the second side plate 212 is fixedly connected to the third plate 33. (Refer to...) Figure 14 After step S100, the method for forming the trim panel on the vehicle pillar further includes step S200:

[0066] The first end of the first side plate is tilted upward away from the second surface and has a first preset angle with the second surface; at the same time, the second end of the second side plate is tilted downward toward the second surface and has a second preset angle with the second surface; wherein, the first preset angle is equal to the second preset angle.

[0067] This method, refer to Figure 9 , Figure 9 The diagram shows a partial view of the optimized flange structure, first mounting structure, and second mounting panel in the vehicle pillar trim panel. The flange structure 21 has a smooth bevel facing the side wall of the covering, which reduces the tensile length of the covering at the flange structure 21, thereby reducing the possibility of the covering being punctured. Compared to... Figure 8 As shown, Figure 8 A cross-sectional view of the optimized front flange structure 61 in the upper trim panel of the vehicle pillar, from... Figure 8 In the image, it can be clearly seen that the pre-optimized flange structure 61 has a Z-shaped structure. The Z-shaped flange structure will increase the fluctuation of the surface, that is, the surface smoothness is poor, which increases the possibility of the covering part of the pre-optimized flange structure 61 being punctured.

[0068] In some embodiments, refer to Figure 9 The second profile also includes a first mounting structure 24 and a lifting structure (not shown in the figure). The first mounting structure 24 has a V-shaped cross-section parallel to the first profile 1. The lifting structure is fixed between the first mounting structure 24 and the second profile 2. There is a height difference between the side wall of the lifting structure facing the first mounting structure 24 and the second profile 2. (Refer to...) Figure 15 After step S100, the method for forming the trim panel on the vehicle pillar further includes step S300:

[0069] Adjust the height difference to the preset height difference, and at the same time reduce the depth of the V-groove of the first mounting structure.

[0070] Specifically, the lifting structure is used to raise the first mounting structure 24, for example, referring to... Figure 7Regarding the first mounting structure 62 before optimization, the design includes a lifting structure, which is equivalent to raising the bottom of the V-shaped first mounting structure 22, reducing the surface drop, and thus further reducing the tensile length of the covering at that point, thereby reducing the possibility of the covering being punctured. The height difference between the side wall of the lifting structure facing the first mounting structure 24 and the second surface 2 can be understood as an adjustable height difference. For example, the size of the height difference can be changed by altering the height of the lifting structure itself in the direction perpendicular to the second surface 2, thereby achieving a preset height difference. Here, the preset height difference refers to a preset height difference after optimizing the height of the lifting structure itself, which facilitates a smooth transition of the second mounting structure 24 towards the side of the covering. Furthermore, by simultaneously reducing the depth of the V-groove in the first mounting structure 24, the bottom of the V-groove structure of the first mounting structure 24 can be raised, and the V-groove of the first mounting structure 24 can be further designed as a shallow V-groove structure (i.e., the distance between the end face of the groove opening and the bottom of the V-groove is reduced). In this way, while increasing the profile height of the first mounting structure 24 relative to the first profile, the height difference of the V-shape at that point is reduced, thereby significantly reducing the stretching length of the covering at that point and thus reducing the possibility of the covering being punctured.

[0071] The above describes a solution to the problem of partial puncture of the first surface 1 when the stretching rate of the covering part (fabric or suede) during low-pressure injection molding of a vehicle pillar trim panel with a large first surface 1 along the demolding direction far exceeds the normal stretching rate. This method allows for the production of qualified low-pressure injection molded products without altering the shape of the first surface 1 (visible area surface) by optimizing the back structure (invisible area) of the first surface 1 and the structure of the second surface 2 (invisible area) in other locations. For example... Figure 12 As shown. Compared with the textured parts produced by ordinary injection molding, the low-pressure injection molded surface formed by this method is softer and will not exhibit defects in injection molded products, such as weld lines, shrinkage marks, and blooming, resulting in a higher product grade; compared with overmolded parts, the molding efficiency is higher, the consistency is better, and it can better meet the needs of mass production, especially for large-volume vehicle models.

[0072] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A trim panel for a vehicle pillar, formed by low-pressure injection molding, characterized in that, include: The base has a first surface, a second surface, and a transition structure. The first surface is fitted into the visible area inside the vehicle and is parallel to a first direction. The second surface is fitted into the invisible area inside the vehicle and is perpendicular to the first direction. The transition structure is fixedly connected between the second surface and the first surface. An overlay, wherein the overlay is applied by low-pressure injection molding to the same side surface of the first profile, the transition structure, and the second profile; The transition structure includes a first plate, a second plate, and a third plate that are smoothly connected end to end. The first plate is smoothly connected to the first profile, and the third plate is fixedly connected to the side wall of the second profile facing the cover. In the direction facing the second plate, the thickness of the first plate and the thickness of the third plate are gradually reduced, and the thickness of the second plate is less than the minimum value of the thickness of the first plate and the third plate. Wherein, the first direction is the demolding direction of the trim panel on the vehicle pillar.

2. The vehicle pillar trim panel according to claim 1, characterized in that, The first plate and the first profile are located on the same plane and are integrally formed; the third plate is parallel to the first direction, the second plate is parallel to the second profile, and the transition structure has a cross-sectional shape of Z-shape in the direction perpendicular to the first direction.

3. The vehicle pillar trim panel according to claim 1, characterized in that, The second profile has a flange structure on the side wall facing the second plate. The flange structure has a first side plate and a second side plate. The first end of the first side plate is fixedly connected to the first profile, and the first end of the first side plate is inclined upward away from the second profile. The first end of the second side plate is smoothly connected to the second end of the first side plate, the second end of the second side plate is fixedly connected to the third plate, and the second end of the second side plate is inclined downward toward the second profile.

4. The vehicle pillar trim panel according to claim 1, characterized in that, The second profile is also provided with a first mounting structure and a lifting structure. The first mounting structure includes a third side plate and a fourth side plate that are connected to each other. The third side plate and the fourth side plate are both inclined upward away from the second profile. The cross-sectional shape of the first mounting structure parallel to the first profile is V-shaped. The lifting structure is fixed between the first mounting structure and the second surface to raise the first mounting structure.

5. The vehicle pillar trim panel according to claim 4, characterized in that, The second profile also has a second mounting panel near the fourth side plate. One end of the second mounting panel is fixedly connected to the second profile. The second mounting panel is tilted upward away from the second profile. The distance between the other end of the second mounting panel and the second profile is greater than or equal to the distance between the free end of the fourth side plate and the second profile.

6. The vehicle pillar trim panel according to claim 1, characterized in that, The second surface also has a third mounting structure, which includes at least a first mounting base and a second mounting base. The first mounting base and the second mounting base are respectively provided with a first mounting hole and a second mounting hole for fastening connection with the rear trim piece. The first mounting base and the second mounting base are fixedly connected. The side of the first mounting base with the first mounting hole is the first side, which faces the covering. The side of the second mounting base with the second mounting hole is the second side, which faces the covering. The first side and the second side are on the same plane.

7. The vehicle pillar trim panel according to claim 2, characterized in that, The second surface is provided with a reinforcing rib. One end of the reinforcing rib is fixedly connected to a side wall of the first surface near the third plate, and the other end is fixedly connected to a side wall of the second surface away from the third plate. The thickness of the reinforcing rib is less than or equal to the thickness of the second plate, and the distance from the end of the reinforcing rib opposite to the second profile to the second profile is less than or equal to one-quarter of the length of the first profile in the first direction. The distance from the end of the reinforcing rib opposite to the first surface to the second surface is less than or equal to one-quarter of the length of the first surface in the first direction.

8. A method for optimizing the forming of a vehicle pillar trim panel, utilizing the vehicle pillar trim panel as described in any one of claims 1 to 7, characterized in that, The molding optimization method includes: The thickness of the first plate and the thickness of the third plate are gradually reduced in the direction toward the second plate, while the thickness of the second plate is reduced to a preset thickness. The preset thickness is less than the minimum thickness of the first plate and the third plate.

9. The molding optimization method according to claim 8, characterized in that, The second profile has a flange structure on the side wall facing the second plate. The flange structure has a first side plate and a second side plate. The first end of the first side plate is fixedly connected to the first profile. The second end of the first side plate is smoothly connected to the first end of the second side plate. The second end of the second side plate is fixedly connected to the third plate. After the step of gradually reducing the thickness of the first plate and the third plate in the direction toward the second plate, and simultaneously reducing the thickness of the second plate to a preset thickness, the forming optimization method further includes: The first end of the first side plate is tilted upward away from the second profile and has a first preset angle with the second profile; at the same time, the second end of the second side plate is tilted downward toward the second profile and has a second preset angle with the second profile. Wherein, the first preset included angle is equal to the second preset included angle.

10. The molding optimization method according to claim 8, characterized in that, The second profile is further provided with a first mounting structure and a lifting structure. The first mounting structure has a V-shaped cross-section parallel to the first profile. The lifting structure is fixed between the first mounting structure and the second profile. There is a height difference between the side wall of the lifting structure facing the first mounting structure and the second profile. After the step of gradually reducing the thickness of the first plate and the third plate in the direction toward the second plate, and simultaneously reducing the thickness of the second plate to a preset thickness, the forming optimization method further includes: The height difference is adjusted to a preset height difference, while the depth of the V-groove in the first mounting structure is reduced.

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