EP3737576A1

EP3737576A1 - Reinforcing element for automobile tailgate inner panel

Info

Publication number: EP3737576A1
Application number: EP18899142.6A
Authority: EP
Inventors: Jie ZENG; Zhiyao ZHANG
Original assignee: Yanfeng Plastic Omnium Automotive Exterior Systems Co Ltd; Plastic Omnium SE
Current assignee: Yanfeng Plastic Omnium Automotive Exterior Systems Co Ltd; Plastic Omnium SE
Priority date: 2018-01-10
Filing date: 2018-12-10
Publication date: 2020-11-18
Also published as: EP3737576A4; CN108116205B; CN108116205A; WO2019137130A1

Abstract

A reinforcing element for an automobile tailgate inner panel (200) is disclosed, the automobile tailgate inner panel (200) comprising a window mounting hole (201), provided in its upper part, and a D pillar region (202) located on both sides of the window mounting hole (201), the reinforcing element comprises a pair of reinforcing components (100) disposed symmetrically in the D pillar region (202), each reinforcing component (100) being formed by a first lateral wall (1), a second lateral wall (2), and a first bottom plate (3), a honeycomb structure (4) being located between the first lateral wall (1) and the second lateral wall (2), the overall reinforcing component (100) being formed by a composite material. A honeycomb-type composite material reinforcing element for an automobile tailgate inner panel (200) is provided which enjoys a high strength and a light weight, formed through a simple process with simplified molds, and having high dimensioning precision and stability.

Description

[Title established by the ISA under Rule 37.2] REINFORCING ELEMENT FOR AUTOMOBILE TAILGATE INNER PANEL

Field of the Invention

The invention relates to the field of automobile manufacture, and more particularly, a reinforcing element for an automobile tailgate inner panel.

Background of the Invention

The body of the tailgate of a hatchback or SUV is generally formed by stamped metal sheet. It has drawbacks such as heavy weight, and limited design options. As the requirement for energy saving and emission reduction becomes stricter, plastic tailgates receive more and more attention due to its advantages such as a high degree of integration, a significant effect in weight reduction, and a high degree of design freedom. However, compared to metal sheet tailgates, plastic doors have much lower mechanical rigidity. Therefore, in the field, a plastic tailgate inner panel is generally combined with a metal insert or metal assembly parts. Only in this way can the performance requirements for the overall tailgate, such as the rigidity and strength of the D pillar region, can be met. A metal insert is formed together with the tailgate inner panel by injection molding, while a metal assembly part is fitted after forming the tailgate inner panel by injection molding.
However, the drawbacks of using a metal insert are: it is formed by stamping, with significant limitation on structural design; it has a large size and a weak structure, resulting in poor precision in dimensioning; it can complicate the process of injection molding and the molds. The drawbacks of using a metal assembly part are such as it is formed by stamping, with significant limitation on structure design; and it is relatively heavy.
Summary of the Invention
An objective of the invention is to provide a reinforcing element for an automobile tailgate inner panel, so as to solve the problems in the prior art that metal inserts and metal assembly parts for an automobile tailgate inner panel cause significant limitations on structural design and poor precision in dimensioning, complicate the process of injection molding and molds, and are heavy.
To solve the above mentioned technical problems, the invention adopts the following technical solution:
A reinforcing element for an inner panel of automobile tailgate is provided. The inner panel of the automobile tailgate comprises a window mounting hole provided in its upper part, and a D pillar region located on both sides of the window mounting hole. The reinforcing element comprises a pair of reinforcing components disposed symmetrically in the D pillar region. Each reinforcing component is formed by a first lateral wall, a second lateral wall, and a first bottom plate. A honeycomb structure is located between the first lateral wall and the second lateral wall. The overall reinforcing element is formed by a composite material.
The honeycomb structure on the reinforcing element is formed by several cells of a hexagonal contour.
The bottom face of cells located in a non-critical zone of the reinforcing element has a reduced thickness or is hollowed-out. The non-critical zone may be determined based on topology analysis.
The composite material includes: continuous glass fibers, carbon fibers, etc. In practice, any material to which an injection molding process or a compression molding can be applied can be used to form the reinforcing element.
Each reinforcing component comprises, from top to bottom, a bent section and a straight section. The straight section of the reinforcing element forms a cavity having a trapeze transversal section surrounded by the first lateral wall, the second lateral wall, and the first bottom plate. Each of the first lateral wall and the second lateral wall forms a trapeze section structure by several alternating protrusions and recesses. The protrusions have a shape that protrudes towards the cavity, while the recesses have a shape that sinks away from the cavity.
Every two protrusions are spaced apart by a recess along the vertical direction of the reinforcing element.
The automobile tailgate inner panel forms in the D pillar region a cavity corresponding to the reinforcing element, surrounded by a third lateral wall, a fourth lateral wall, and a second bottom plate. The outer side of the first lateral wall and/or the second lateral wall of the reinforcing element is provided with a first barb and the inner side of the third lateral wall and/or the fourth lateral wall of the automobile tailgate inner panel is provided with a second barb corresponding to the first barb.
The first barb of the reinforcing element is inserted into the gap between the third lateral wall and the second barb, and/or into the gap between the fourth lateral wall and the second barb of the automobile tailgate inner panel. Thus, the deformation of the opening in the D pillar region of the automobile tailgate inner panel is limited.
A part of the reinforcing element is further provided with a metal insert structure that is integrally formed with the reinforcing element. Even though a metal insert is used, this embodiment is still advantageous comparing to the prior art, since it is easier to overmold such smaller metal inserts in a smaller plastic part (i.e. in the reinforcing component) than to overmold a big metal insert (of the size of the whole reinforcing component) inside the whole plastic inner panel.
The reinforcing element is connected with the automobile tailgate inner panel by a fastener.
Based on a composite material in combination with a special honeycomb structural design, the reinforcing element for an automobile tailgate inner panel provided by the present invention provides a honeycomb-type composite material reinforcing element that not only increases significantly the design freedom of the product by fully exploiting the formability of the plastic, but also ensures the mechanical performances of the product itself, including rigidity and strength. Further, in combination with the special structural adaptation and design, the dimensioning precision and stability of the product are both greatly improved.
Another subject matter of the invention is an assembly of the automobile tailgate inner panel and the reinforcing element as described above.
Preferably, the automobile tailgate inner panel forms a cavity in the D pillar region corresponding to the reinforcing element, surrounded by a third lateral wall, a fourth lateral wall and a second bottom plate, the inner side of the third lateral wall and/or the fourth lateral wall of the automobile tailgate inner panel being provided with a second barb to cooperate with a first barb provided on the outer side of the first lateral wall and/or the second lateral wall of the reinforcing element.
In conclusion, the invention provides a honeycomb-type composite material reinforcing element for an automobile tailgate inner panel that enjoys a high strength and a light weight, formed through a simple process with simplified molds, and having high dimensioning precision and stability.
Description of the Drawings
Fig. 1 is a schematic view of the structure of a reinforcing element of a preferred embodiment of the invention that is fitted together with an automobile tailgate inner panel;
Fig. 2 is a front view of one of the pair of reinforcing components shown in Fig. 1;
Fig. 3 is a perspective view of the reinforcing component shown in Fig. 2;
Fig. 4 is an enlarged schematic view of a part of the assembly of the reinforcing element shown in Fig. 1and an automobile tailgate inner panel;
Fig. 5 is a sectional view along the section line A-Ain Fig. 4;
Fig. 6 is a perspective view of a reinforcing element of another preferred embodiment of the invention;
Fig. 7 is a perspective view of a reinforcing element of yet another preferred embodiment of the invention.

Detailed Description of the Invention

The invention is further described below in reference to specific embodiments. It should be understood that the following embodiments are merely used to illustrate the invention rather than limit the scope of the invention.
According to a preferred embodiment of the invention, as shown in Fig. 1, a reinforcing element for an automobile tailgate inner panel is provided. The figure shows both the reinforcing element, and an automobile tailgate inner panel 200, which are assembled together.
The automobile tailgate inner panel 200 comprises a window mounting hole 201 provided in its upper part, and a D pillar region 202 located on both sides of the window mounting hole 201, as shown by the part circled in Fig. 1.
The reinforcing element comprises a pair of reinforcing components 100 (parts shown by bold lines in Fig. 1) disposed symmetrically in the D pillar region 202. As shown in Fig. 2, each reinforcing component 100 comprises, from top to bottom, a bent section 101 and a straight section 102. Both the bent section 101 and the straight section 102 are formed by a first lateral wall 1, a second lateral wall 2, and a first bottom plate 3 (see Fig. 3) . A honeycomb structure 4 is located between the first lateral wall 1 and the second lateral wall 2. The overall reinforcing component 100 is formed by a composite material.
According to the preferred embodiment, based on the composite material, using an ordinary injection molding process (as an example and not a limitation; it should be understood that the molding process is not limited to injection molding, and can be another molding process) , and in combination with the special honeycomb structure, a honeycomb-type composite material reinforcing element is provided to replace the metal inserts and metal assembly parts used in the prior art. It not only significantly increases the design freedom of the product by fully exploiting the formability of the plastic, but also ensures the mechanical performances of the product itself (including rigidity and strength) , overcoming the drawbacks of metal inserts and metal assembly parts in the prior art of being significantly limited in structural design, having a poor dimensioning precision, complicating the injection molding process and molds, and being relatively heavy.
As shown in Fig. 2, the honeycomb structure 4 on the reinforcing component 100 is formed by several cells 41 of a hexagonal contour. Further preferably, it is calculated by topology analysis (i.e., CAE simulation) which region (s) is subject to a relatively small stress and thus having some redundancy. Then the bottom face of the cell 41’in this non-critical zone (as shown by the part circled in the figure) is thinned or hollowed-out to reduce the weight. The honeycomb structure itself is a structure that is both light and strong. In combination with effective topology hollowing, the overall reinforcing element achieves a minimization of weight while ensuring its strength.
The non-critical zone that can be thinned or hollowed-out being determined via the above-mentioned topology analysis, preferably, the reinforcing component 100 with a thinned or hollowed-out design is formed by a one pass injection molding, no further processing is needed.
According to the invention, any material to which an injection molding process can be applied (such as continuous glass fiber and carbon fiber) can be used to form the reinforcing element.
According to the preferred embodiment, as shown in Fig. 3, the straight section 102 of the reinforcing component 100 forms a cavity with a trapeze transversal section surrounded by the first lateral wall 1, the second lateral wall 2, and the first bottom plate 3. Each of the first lateral wall 1 and the second lateral wall 2 forms a structure of a trapeze section by several protrusions 11 and recesses 12. The protrusions 11 have a shape that protrudes towards the cavity, and the recesses 12 have a shape that sinks away from the cavity.
Every two protrusions 11 are spaced by a recess 12 along the vertical direction of the reinforcing component 100 when it is being used. It should be noted that the “vertical direction” here used refers to the Z direction of the vehicle.
According to the preferred embodiment, in reference to Fig. 4 and Fig. 5, the automobile tailgate inner panel 200 forms a cavity corresponding to the reinforcing component 100 in the D pillar region 202 that is surrounded by a third lateral wall 203, a fourth lateral wall 204, and a second bottom plate 205. To help correct the deformation of the D pillar region 202 of the automobile tailgate inner panel 200, the outer side of the first lateral wall 1 and the second lateral wall 2 of the reinforcing component 100 are provided with first barbs 5, and the inner side of the third lateral wall 203 and the fourth lateral wall 204 of the automobile tailgate inner panel 200 is provided with second barbs 206 that cooperate with the first barbs 5. Preferably, the first barbs 5 of the reinforcing component 100 are inserted into the gap between the third lateral wall 203 and the second barb 206 of the automobile tailgate inner panel 200, and the gap between the fourth lateral wall 204 and the second barb 206.
Because the D pillar region of an automobile tailgate inner panel is usually a structure with a V-shaped opening, and that part of the inner panel is also a visible face, it is impossible to add any special structure to increase its strength, resulting in the enlarging of the V-shaped opening and a significant deviation in dimensions. According to the preferred embodiment provided by the invention, by adding cooperating barb structures on both the reinforcing component 100 and the automobile tailgate inner panel 200, with the relatively high rigidity and dimensioning precision of the reinforcing component 100 itself, the deviation in dimensions of the automobile tailgate inner panel 200 can be corrected.
According to a preferred embodiment, as shown in Fig. 6, a region on the reinforcing component 100, in particular, the region that requires special mounting strength (as shown by the part circled by the oval in the figure) , is further provided with a metal insert structure 7. During processing, the metal insert structure 7 and the composite material forming the body of the reinforcing component 100 are preferably integrally molded by injection.
As hinges and gas struts are the main points subject to standing stress in an automobile tailgate, the requirements for their strength, rigidity, and anti-fatigue performance are very strict. Their performance requirements can be well met by the invention with the form of combining the composite material and the metal insert. Moreover, through the transmission of force by the intermediate reinforcing element, the pneumatic lifting force can be effectively transmitted to a hinge, reducing the stress applied on weak points of the window frame of the tailgate.
According to a preferred embodiment, in combination with CAE simulation analysis, the mounting points are appropriately located so as to optimize the rigidity of the overall tailgate. As shown in Fig. 7, at the location of those mounting points, the reinforcing component 100 is connected with the automobile tailgate inner panel 200 by fasteners 8, for example screws. The inner panel 200 comprises bosses to receive the screws. The bosses are formed on the inner face of the inner panel, i.e. on the face facing the reinforcing component.
According to the above-described preferred embodiments of the invention, by using a composite material having a high strength and a light weight, in combination with a honeycomb structure, a honeycomb-type composite material reinforcing element is provided. Compared to metal reinforcing elements, the reinforcing element has a significantly lighter weight while maintaining its performances, and can meet various geometric design requirements by fully exploiting the formability of injection molding. Finally, in combination with a special trapeze lateral wall structure and barb structure, the problem of poor dimensioning precision of the opening of the D pillar of a plastic tailgate can be effectively solved.
What has been described above is merely preferred embodiments of the invention, not for the purpose of limiting the scope of the invention. The above-described embodiments of the invention can be subject to various modifications. All simple, equivalent modifications and embellishments made according to the claims and specification of the present application fall within the scope of protection of the claims of the invention. What has not been described in detail all belongs to conventional technology.

Claims

A reinforcing element for an automobile tailgate inner panel (200) , the automobile tailgate inner panel (200) comprising a window mounting hole (201) provided in its upper part, and a D pillar region (202) located on both sides of the window mounting hole (201) , characterized in that, the reinforcing element comprises a pair of reinforcing components (100) disposed symmetrically in the D pillar region (202) , each reinforcing component (100) being formed by a first lateral wall (1) , a second lateral wall (2) and a first bottom plate (3) , a honeycomb structure (4) being located between the first lateral wall (1) and the second lateral wall (2) , the overall reinforcing component (100) being formed by a composite material.
The reinforcing element according to claim 1, wherein the honeycomb structure (4) on the reinforcing component (100) is formed by several cells (41) of a hexagonal contour.
The reinforcing element according to anyone of the preceding claims, wherein the bottom face of the reinforcing component (100) in a non-critical zone has a reduced thickness or is hollowed-out.
The reinforcing element according to anyone of the preceding claims, wherein the composite material includes: continuous glass fibers and/or carbon fibers.
The reinforcing element according to anyone of the preceding claims, wherein the reinforcing component (100) comprises a straight section (102) , the straight section (102) which forms a cavity having a trapeze transversal section surrounded by the first lateral wall (1) , the second lateral wall (2) and the first bottom plate (3) .
The reinforcing element according to claim 5, wherein in the straight section (102) , each of the first lateral wall (1) and the second lateral wall (2) forms a trapeze section structure by several alternating protrusions (11) and recesses (12) , the protrusions (11) having a shape that protrudes towards the cavity, the recesses (12) having a shape that sinks away from the cavity.
The reinforcing element according to claim 6, wherein every two protrusions (11) are spaced apart by a recess (12) along the vertical direction of the reinforcing component (100) .
The reinforcing element according to anyone of the preceding claims, wherein the outer side of the first lateral wall (1) and/or the second lateral wall (2) of the reinforcing component (100) is provided with a first barb (5) , which is designed to cooperate with a second barb (206) provided on the automobile tailgate inner panel (200) .
The reinforcing element according to claim 8, wherein the first barb (5) of the reinforcing component (100) is inserted into the gap between a wall of the automobile tailgate inner panel (200) and the second barb (206) .
The reinforcing element according to anyone of the preceding claims, wherein a region on the reinforcing component (100) is further provided with a metal insert (7) that is integrally formed with the reinforcing component (100) .
The reinforcing element according to anyone of the preceding claims, wherein the reinforcing component (100) is fixed to the automobile tailgate inner panel (200) by fasteners (8) .
An automobile tailgate, comprising an inner panel (200) and a reinforcing element according to anyone of the preceding claims.
The automobile tailgate according to claim 12, wherein the automobile tailgate inner panel (200) forms a cavity in the D pillar region (202) corresponding to the reinforcing component (100) , surrounded by a third lateral wall (203) , a fourth lateral wall (204) and a second bottom plate (205) , the inner side of the third lateral wall (203) and/or the fourth lateral wall (204) of the automobile tailgate inner panel (200) being provided with a second barb (206) to cooperate with a first barb (5) provided on the outer side of the first lateral wall (1) and/or the second lateral wall (2) of the reinforcing component (100) .