JP4093124B2 - Center pillar structure of automobile - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin-made center pillar structure that functions as a strength member of an automobile body , and more particularly to a structure that fully considers collision energy absorption characteristics without sacrificing weight reduction.
[0002]
[Prior art]
As a reinforcing structure of a vehicle body part, for example, a reinforcing structure of a center pillar having a closed cross-sectional structure that functions as a strength member, a structure described in Patent Document 1 has been proposed.
[0003]
In this conventional structure, a reinforcing sheet containing carbon fibers is closely attached to the inner surface of a so-called closed cross-sectional center pillar composed of an outer panel and an inner panel for the purpose of obtaining a sufficient reinforcing effect without causing a significant increase in weight. The composite structure is made by filling the inside with a synthetic resin foam material that adheres to the reinforcing sheet and using the reinforcing sheet and resin material in addition to the metal outer panel and inner panel. As a thing.
[0004]
In the conventional technology represented by Patent Document 1, the outer panel and the inner panel, which are the main elements of the center pillar, are both made of metal, and the weight of the vehicle body is improved in order to improve fuel consumption and power performance. There is still room for improvement when trying to achieve further weight reduction.
[0005]
For this reason, in order to further reduce weight and improve impact resistance, the center pillar itself may be formed of a resin material including a fibrous reinforcing material, that is, a so-called fiber reinforced resin material. Proposed.
[0006]
[Patent Document 1]
JP 2000-38157 A (FIG. 3)
[0007]
[Patent Document 2]
JP 11-60886 A (2nd page)
[0008]
[Problems to be solved by the invention]
However, when the center pillar itself is formed of fiber reinforced resin, even if the desired strength is obtained, if a bending load due to impact is applied, for example, in the case of a side collision, the elongation at break of the matrix resin material itself is several percent. As a result, cracks are generated at the break point at an early stage, and the load applied to the center pillar itself is drastically reduced, so that the impact energy cannot be sufficiently absorbed. In other words, since the center pillar itself breaks at the break point, it becomes impossible to transmit the impact load to the vehicle body side through the upper and lower ends of the center pillar. Can no longer absorb.
[0009]
The present invention has been made paying attention to such problems, and in particular, it is possible to provide a necessary and sufficient impact energy absorption performance while assuming that the center pillar is formed of a fiber reinforced resin material. The structure is provided.
[0010]
[Means for Solving the Problems]
The invention according to claim 1, at least part of the longitudinal direction of the outer surface of the outer panel which is formed in a substantially hat-shaped cross section with a resin material containing a reinforcement fibrous outer panel itself sectional shape substantially A metal reinforcement having a similar shape is arranged , and a metal inner panel is attached to the open side of the outer panel, and the flange and inner panel of the outer panel and the reinforcement are fastened together. Formed as a closed cross-section structure by joining, overlapping portion with the outer panel of the top plane of the above-mentioned reinforcement, and the bending deformation easy portion in the bending direction at the portion where the reinforcement is bent when a bending load is input And forming a bending deformation promoting bead portion that is convex from the outer surface side to the inner surface side of the outer panel Outer panel that receives the auxiliary bead portion that is orthogonal to the bending deformation promoting bead portion and is convex from the inner surface side to the outer surface side of the outer panel in the overlapping portion with the outer panel in the top plane of the reinforcement. It was formed with the bead part of the side . In this case, as the reinforcement, for example, a steel plate having excellent elongation characteristics is used .
[0013]
Thus, the invention described in claim 1, in that it comprises a reinforcement made of metal made of resin outer panel having excellent elongation properties, for example, when the input load due to bending is applied, the outer panel itself breaks deformed elongation as wake easily deformable portion bending metal reinforcement as the, so that thereby secure a necessary and sufficient impact energy absorption amount without depending on the material of the outer panel.
[0014]
【The invention's effect】
According to the first aspect of the present invention, there is an effect that the deformation and the energy absorption amount in the energy absorption mode intended at the time of an input load action by bending can be easily and surely secured while being a resin center pillar . That is, since the resin of the outer panel by the input load due to bending is to bend while deforming the reinforcement even broken, yet lowering of the load even if the maximum load is generated can be prevented, a necessary and sufficient impact Ensuring energy absorption.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 and the following drawings show a preferred embodiment of the present invention .
[0016]
As shown in FIGS. 1A and 1B, the center pillar 2 is made of a resin outer panel 3 having a substantially hat-shaped cross-sectional shape and a metal (for example, made of a steel plate) disposed on the open side of the outer panel 3. The inner panel 4 is formed in a closed cross-sectional structure, and a metal reinforcement 5 having a shape substantially similar to the outer panel 3 itself is disposed on the outer side (outer surface side) of the outer panel 3. The outer panel 3 and the inner panel 4 and the reinforcement 5 are firmly coupled to each other by fastening them with a plurality of rivets 6 to the flange portions 3a and 5a. The force 5 is firmly coupled to the top flat surfaces 3b, 5b and the vertical wall portions 3c, 5c other than the flange portions 3a, 5a so as to be fastened together by fastening with a plurality of rivets 6. The inner panel 4 is provided in order to improve the strength and rigidity of the outer panel 3 while preventing the outer panel 3 from opening the substantially hat-shaped cross section.
[0017]
The outer panel 3 is made of, for example, a so-called fiber reinforced resin such as nylon (registered trademark) or polypropylene containing glass fiber or carbon fiber as a reinforcing material, and a plurality of ribs 7 project from the inner and lower surfaces thereof. In addition, a single bead portion 8 is formed along the longitudinal direction on the outer surface side. These ribs 7 and bead portions 8 are simultaneously molded when the outer panel 3 is molded by, for example, an injection molding method.
[0018]
The reinforcement 5 is bent by, for example, press molding so that the cross-sectional shape thereof is substantially similar to that of the outer panel 3, and is bent at the center of the top plane 5b in the longitudinal direction, that is, when a bending load is input to the center pillar 2. Is formed with a bending deformation promoting bead portion 9 which is a bending deformation easy portion having a convex shape having a substantially semicircular cross section from the outer surface side to the inner surface side of the outer panel 3. Further, the reinforcement 5 is formed with a bulging auxiliary bead portion 10 having a substantially rectangular cross section and a convex shape along the longitudinal direction so as to be orthogonal to the bending deformation promoting bead portion 9. It is aligned with the bead portion 8 on the outer panel 3 side. In addition, the cross-sectional shape of the bending deformation promotion bead part 9 and the auxiliary bead part 10 can be set arbitrarily. Further, a concave portion for receiving the bending deformation promoting bead portion 9 is formed on the outer panel 3 side.
[0019]
Here, instead of fastening the flange portion 3a of the outer panel 3 and the inner panel 4 with the rivet 6, a projection 11 formed in advance on the flange portion 3a side is formed in the hole 4a on the inner panel 4 side as shown in FIG. You may make it fasten by what is called a heat caulking system which inserts and performs caulking processing. The same applies to a portion where not only the outer panel 3 and the inner panel 4 but also the reinforcement 5 is polymerized, or a portion where the outer panel 3 and the reinforcement 5 are polymerized.
[0020]
According to the center pillar 2 configured in this manner, as shown in FIG. 1, when the top plane 3b side of the outer panel 3 is set as the input side, for example, when the energy equivalent to the side collision of the vehicle, that is, the bending load F, is input. If a moment is generated and the load F, which is an external force, is less than the allowable limit of the center pillar 2, the center pillar 2 reinforced by the inner panel 4 or the reinforcement 5 has a predetermined strength against the load F. Will be obtained.
[0021]
On the other hand, when the bending load F is greater than the allowable limit, the strength of the inner panel 4 that receives the tensile load is high as shown in FIG. 4, and therefore the outer panel 3 and the reinforcement 5 on the compression side are high. As shown by the arrow M, a compressive load is applied to the top flat surfaces 3b and 5b. At this time, since the outer panel 3 has a small elongation rate of the resin layer itself, the load input point cracks and breaks, but the reinforcement 5 is triggered by the bending deformation promoting bead portion 9 as shown in FIG. It will buckle and deform, and it will sustain the energy absorption effect.
[0022]
FIG. 5 is a diagram showing the relationship between the load and displacement at the time of load input in the bending mode with respect to the center pillar 2 as described above. FIG. In this case, the load suddenly decreases after the maximum load is generated and the sufficient energy absorption effect is not exhibited. On the other hand, in the present embodiment shown by the solid line, the reinforcement 5 is broken even after the maximum load is generated. The deformation progresses without being carried out, and a certain load is maintained along with the deformation, and a necessary and sufficient energy absorption effect is obtained. That is, according to the present embodiment, a necessary and sufficient impact energy absorption effect can be obtained while reducing the weight of the center pillar 2 with the adoption of the outer panel 3 made of fiber reinforced resin.
[0023]
In addition, since the auxiliary bead portion 10 is preset in the reinforcement 5 so as to be orthogonal to the bending deformation promoting bead portion 9, the auxiliary bead portion 10 having a high compressive load on the top plane 5b side is provided. The center pillar 2 including the reinforcement 5 can be surely buckled and deformed by the deformation at the bend deformation promoting bead portion 9 as a result of the deformation at the bend deformation promoting bead portion 9 and more stable energy. Absorption characteristics will be obtained.
[0024]
Further, since the auxiliary deformation bead portion 10 in addition to the bending deformation promoting bead portion 9 formed as the bending deformation easy portion in the reinforcement 5 is simply bent, it can be easily formed by press molding or the like. Because of these functions, the behavior at the time of load input is stabilized, and the reliability of energy absorption characteristics is further increased.
[0025]
FIG. 6 shows another example in which the outer panel 3 and the reinforcement 15 are integrated as a second embodiment of the present invention. That is, in the first embodiment, the outer panel 3 and the reinforcement 5 are fastened by the rivets 6 as shown in FIG. 1, whereas in the second embodiment, the fibers are When the outer panel 3 made of reinforced resin is injection-molded, insert molding is performed using the metal reinforcement 15 as an insert member, so that the two are integrated with each other.
[0026]
As is clear from FIG. 6, a plurality of embossed portions 12 are formed in a portion corresponding to the fastening position by the rivet 6 in FIG. The embossed portion and the auxiliary bead portion 13 are formed with through-holes 14 so as to bulge out in a convex shape. Then, after positioning the reinforcement 15 as the insert member in the mold 20 composed of the core block 16 and the cavity block 17, both are clamped, and a predetermined resin material is filled into the cavity R through the gate portion 18. And then molded. At that time, the resin material flows through the through holes 14 in the embossed portions 12 and the auxiliary bead portions 13, so that both the front and back sides of the embossed portions 12 and the auxiliary bead portions 13 are filled with the resin layer. The outer panel 3 and the reinforcement 15 are integrally formed by the same method as that shown in FIG.
[0027]
Therefore, according to the second embodiment, since the reinforcement 15 is integrated as an insert member at the time of the injection molding of the outer panel 3, the reinforcement of the reinforcement 15 into the outer panel 3 is facilitated.
[Brief description of the drawings]
1A and 1B are views showing a preferred embodiment of the present invention, in which FIG. 1A is an enlarged view of a main part of the center pillar shown in FIG. 2, and FIG. 1B is an enlarged cross-sectional view of FIG.
2A is a perspective view showing a schematic structure of an automobile body, and FIG. 2B is an enlarged view of a part a in FIG.
FIG. 3 is an enlarged view of a main part showing a modification of FIG.
4 is an explanatory diagram showing the behavior of the center pillar in FIG. 1 when a load is input in a bending mode. FIG.
FIG. 5 is a characteristic diagram showing a load-displacement characteristic at the time of load input in FIG. 4;
FIG. 6 is a sectional view of a mold for insert-molding an outer panel using a reinforcement as an insert member as a second embodiment of the present invention.
[Explanation of symbols]
2 ... Center pillar 3 ... Outer panel
3a ... Flange 3b ... Top plane 4 ... Inner panel 5 ... Reinforce
5a ... Flange 5b ... Top plane 6 ... Rivet
7 ... Ribs
8 ... Bead part 9 ... Bending deformation promotion bead part (bending deformation easy part)
10 ... Auxiliary bead part 13 ... Auxiliary bead part 15 ... Reinforce (insert member)

Claims (3)

At least part of the longitudinal direction of the fibrous outer surface side of the outer panel which is formed in a substantially hat-shaped cross section with a resin material containing a reinforcement, a metal reinforcement which forms a cross-sectional shape substantially similar shape of the outer panel itself Of a closed cross-section structure by attaching a metal inner panel to the open side of the outer panel and jointly connecting the outer flange and the flange portion of the reinforcement together with the inner panel. Formed as
Convex shape from the outer surface side of the outer panel to the inner surface side as an easily bending-deformable portion in the bending direction at the portion where the reinforcement is bent when the bending load is input on the top plane of the above-mentioned reinforcement And forming a bend deformation promoting bead portion that becomes,
Outer panel that receives the auxiliary bead portion that is orthogonal to the bending deformation promoting bead portion and is convex from the inner surface side to the outer surface side of the outer panel in the overlapping portion with the outer panel in the top plane of the reinforcement. A center pillar structure of an automobile characterized by being formed together with a bead portion on the side . The center pillar structure for an automobile according to claim 1, wherein the outer panel and the reinforcement are coupled together by a plurality of joints at portions other than the flange portions . The center pillar structure for an automobile according to claim 1 or 2, wherein ribs are provided on the inner and lower surfaces of the outer panel .

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