JP2004074834A - Bumper reinforcing material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide structure a which demonstrates structure strength and shock absorbing performance not inferior to a bumper reinforcing material of closed section structure by preventing the top and bottom surfaces from opening in the bumper reinforcing material of the opened section structure. <P>SOLUTION: The bumper reinforcing material consists of a main reinforcing material 3 of the opened section structure consisting of a front surface 9 and top and bottom surfaces 10, 11, and an auxiliary reinforcing material 1 suspended from the front surface 9 of the main reinforcing material 3 to the top and bottom surfaces 10, 11 respectively. The auxiliary reinforcing material 1 forms a section having projecting ridge-folding part 14 toward the front surface 9. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bumper reinforcing material having an open cross-sectional structure (open rear surface) including a front surface and upper and lower side surfaces.
[0002]
[Prior art]
2. Description of the Related Art In recent years, a bumper, which is one of security parts of an automobile, is generally composed of a bumper reinforcing material as a strength member and a bumper cover as a decorative member. The bumper reinforcing material can be divided into a bumper reinforcing material having a closed cross-sectional structure and a bumper reinforcing material having an open cross-sectional structure due to a difference in cross-sectional shape. When high structural strength is required, a bumper reinforcement with a closed cross section is superior, but a bumper reinforcement with an open cross section that is easy to process and can be manufactured at low cost is often used, and the structural strength and shock absorption are high. Various proposals have been made to bring the performance closer to that of a bumper reinforcing material having a closed sectional structure (U.S. Patent No. 2,554,459, US 2002/0047281, DE 199 12 272 A1, JP-A-09-095189, US Pat. No. 4,492,398, and US Pat.
[0003]
[Problems to be solved by the invention]
The reason why the bumper reinforcement with the open cross-section structure is inferior in structural strength to the bumper reinforcement with the closed cross-section structure is that the rear edge is free and the upper and lower sides are restrained by the front surface. This lowers the section modulus. In addition, the lowering of the section modulus naturally occurs when an impact is applied to the front surface from the front, so that the impact energy that can be absorbed at the same time when the upper and lower side surfaces are opened is reduced, and the impact absorption performance as a bumper reinforcing material is reduced. Had the problem of not being able to demonstrate.
[0004]
From now on, the upper and lower side surfaces must not be opened so that the bumper reinforcing material having the open cross-sectional structure exhibits structural strength equivalent to that of the bumper reinforcing material having the closed cross-sectional structure and does not cause a reduction in shock absorbing performance when a shock is applied. What should I do? Therefore, a study was conducted to develop a bumper reinforcement having an open cross-sectional structure that has a structure that mainly prevents the upper and lower side surfaces from being opened, and exhibits structural strength and shock absorption performance that are not inferior to those of a bumper reinforcement having a closed cross-section.
[0005]
[Means for Solving the Problems]
As a result of the study, what was developed consists of a main reinforcing material with an open cross-sectional structure consisting of the front and upper and lower side surfaces, and auxiliary reinforcing materials erected from the front of this main reinforcing material to the upper and lower sides, respectively. It is a bumper reinforcing material formed with a mountain-folded portion having a convex cross section toward it. The bumper reinforcement of the present invention is composed of a combination of a main reinforcement constituting the outer shape and an auxiliary reinforcement for preventing the upper and lower side surfaces of the main reinforcement from opening. The main reinforcing material is usually formed from one sheet material by roll forming or the like. The auxiliary reinforcing member is formed of inner and outer mountain skirts sandwiching the mountain-folded portion. Inside the front reinforcing member and the inner side surrounded by the upper and lower side surfaces, (1) a two-member structure that is separately erected from the front side inner side to the upper and lower side inner sides. (Separate body type) and (2) a one-member configuration (integral type) that is continuously installed on the lower side inner side, the front side inner side, and the upper side inner side.
[0006]
The auxiliary reinforcing material in the bumper reinforcing material of the present invention is not only erected on the front surface and the upper and lower side surfaces at the ends, but also has a mountain bent portion sandwiched between the inner and outer mountain skirt surfaces formed to have a convex cross section toward the front surface. There are features. Thereby, for example, when the bumper reinforcing material receives an impact from the front surface, the inner mountain hem surface joining the end portion to the front surface and the outer mountain hem surface joining the end portion to the upper and lower side surfaces are relatively positioned with respect to the crease portion. It retreats, and the inner and outer mountain skirts are folded around the mountain fold, that is, the outer mountain skirt attempts to tilt inward. The inward tilt of the outer skirt prevents the upper and lower side surfaces from opening, and prevents the structural strength and shock absorbing performance of the bumper reinforcement having the open cross-sectional structure from deteriorating.
[0007]
Since the auxiliary reinforcing material forms a mountain fold that is convex toward the front surface, it is necessary to secure a space in which the mountain fold protrudes. In this case, if the front surface of the main reinforcement is flat, the inner joint surface turned back from the end of the inner mountain skirt surface is joined to the front surface. However, there is a possibility that the turning back of the inner mountain skirt surface and the inner joint surface may obstruct the following of the inner mountain skirt surface with respect to the front surface. In view of this, the main reinforcing member is preferably provided with a front groove having a concave cross section composed of a groove bottom surface and a groove side surface on the front surface, and auxiliary reinforcing members provided on the upper and lower side surfaces from the front groove portion. If the bottom of the groove is located at a position lower than the front by the protrusion of the crest, the end of the inner skirt can be directly joined to the bottom of the groove. In addition, the front groove increases the rigidity of the front surface and suppresses partial deformation. This is because, when a partial impact such as a pole collision is received, the front surface is widely deformed in the extending direction (usually in the width direction of the vehicle), and the partial deformation = buckling reduces the impact absorbing performance. It also has the effect of preventing.
[0008]
Here, when the main reinforcing member is provided with the front groove portion, the auxiliary reinforcing member may be provided with the mountain bent portion close to the groove side surface of the front groove portion in order to smoothly guide the folding of the inner and outer mountain bottom surfaces. The folding of the inner and outer mountain skirts is promoted by the relative retreat of the inner and outer mountain skirts with respect to the mountain fold as described above. Here, when the mountain-folded portion moves away from the groove side surface, that is, approaches the upper and lower side surfaces, the auxiliary reinforcing member is less susceptible to the retreat of the front groove portion. In addition, since the moment of the outer mountain skirt surface inclining inward with respect to the upper and lower side surfaces is reduced, the effect of suppressing the opening of the upper and lower side surfaces is reduced. For this reason, it is preferable that the mountain fold is made as close as possible to the inside and to the groove side surface of the front groove.
[0009]
More specifically, it is preferable that the inner mountain skirt surface is close to the groove side surface but does not adhere to the groove side surface, and has an open relation to the groove side surface from the end joined to the groove bottom surface. When the inner and outer mountain skirts are folded around the mountain fold, the inner mountain skirt is relatively tilted toward the front groove, so that it is desirable that the structure be configured to allow the tilt. The gap between the inner mountain skirt surface and the groove side surface in an open relationship is one of structures that allow the inner mountain skirt surface to tilt as a tilt allowance of the inner mountain skirt surface, and is preferable as a structure that can be realized relatively easily.
[0010]
As described above, the auxiliary reinforcing member may be configured as a separate body, but there are problems that the number of members is increased, positioning at the time of joining is difficult, and retreat of the front surface or the front groove is uneven. Therefore, in order to suppress an increase in the number of members and to receive the retreat of the front surface or the front groove portion vertically evenly, the auxiliary reinforcing material has an auxiliary bottom portion formed at the end of the pair of inner mountain skirt surfaces by forming an auxiliary bottom surface. It is preferable that the upper and lower members are integrally formed, and the groove bottom surface of the front groove portion and the auxiliary bottom surface of the auxiliary groove portion are joined in a contact state.
[0011]
Here, it is desirable that each mountain bend is provided in a vertically symmetrical position so that the upper and lower inner and outer mountain skirt surfaces are similarly folded by the retreat of the front groove received uniformly in the vertical direction. Further, in order to sufficiently exert the effect of the retreat of the front groove portion, it is preferable that even with the integrated auxiliary reinforcing member, each mountain bent portion is brought close to the groove side surface of the front groove portion. At this time, it is also desirable that the inner mountain skirt surface does not adhere to the groove side surface, and the end portion joined to the groove bottom surface preferably has an open relation to the groove side surface.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an example in which an upper and lower integrated auxiliary reinforcing member 1 is used as a main reinforcing member 3 having a front groove 2. FIG. 2 is an upper and lower separate auxiliary reinforcing member 4 and a main reinforcing member having a front groove 2. 3 is a cross-sectional view illustrating an example in which the upper and lower integrated auxiliary reinforcing members 5 are used as a main reinforcing member 6 without a front groove, and FIG. 4 is a cross-sectional view illustrating upper and lower separate auxiliary reinforcing members 7. 5 is a cross-sectional view showing an example in which the main reinforcing member 6 having no front groove is used, FIG. 5 is a partial perspective view of an example in which the auxiliary reinforcing member 1 having the same length as the main reinforcing member 3 is used, and FIG. FIG. 7 is a partial perspective view of an example in which a plurality of short auxiliary reinforcing members 8 are used. FIG. 7 shows a bumper reinforcing member (main reinforcing member 3 and auxiliary reinforcing member 1) deformed when an impact F is applied from the front. FIG. 2 is a sectional view corresponding to FIG.
[0013]
The bumper reinforcing material of the present invention has various configurations depending on the combination of whether the auxiliary reinforcing material is an integral type, a separate type, and whether or not the bumper reinforcing material has a front groove portion (see succeeding FIGS. 2 to 4). However, the most preferable configuration is an example in which the vertically integrated auxiliary reinforcing member 1 shown in FIG. 1 is used as the main reinforcing member 3 having the front groove 2. The main reinforcing member 3 of this embodiment includes a front surface 9 provided with a front groove 2 and upper and lower side surfaces 10 and 11. The front groove 2 is formed by a continuous bending process from the front 9, and is formed as a concave groove formed by a pair of groove side surfaces 12, 12 and a groove bottom surface 13 in the extending direction of the main reinforcing member 3 (in the direction orthogonal to the paper surface in FIG. 1). ). In the present embodiment, the provision of the front groove 2 secures a space in which the pair of crests 14 formed in the auxiliary reinforcing member 1 project. The upper and lower side surfaces 10 and 11 are formed with stepped portions 16 for the purpose of reinforcement and for positioning the outer mountain skirt surface 15 described later. The step portion 16 also has a function of a rib for increasing the rigidity of the upper and lower side surfaces 10 and 11. Although the back surface is open, the rear ends of the upper and lower side surfaces 10 and 11 are extended and bent inward to form rib back surfaces 17 and 17.
[0014]
The auxiliary reinforcing member 1 is formed by bending the inner mountain skirt surfaces 19, 19, the mountain bent portions 14, 14 and the outer mountain skirt surfaces 15, 15 symmetrically about the auxiliary groove portion 18 joined to the front groove portion 2 in the cross-sectional shape. It is integrally formed. The auxiliary groove portion 18 joins the auxiliary bottom surface 20 to the groove bottom surface 13 of the front groove portion 2 in a contact state. Further, the outer mountain skirt surface 15 is directed to the stepped portion 16 in which the outer bent edge 22 of the outer contact surface portion 21 extending in parallel with the upper and lower side surfaces 10, 11 is formed on the upper and lower side surfaces 10, 11. Are joined to the upper and lower side surfaces 10 and 11 in an inscribed state. Here, since the inner mountain skirt surface 19 forms a tilt allowance toward the groove side surface 12 of the front groove portion 2, the opening degree of the groove side surface 12 with respect to the groove bottom surface 13 (each tangent of the groove bottom surface 13 and the groove side surface 12 intersects). The angle is larger than the opening angle.
[0015]
The angle formed by the inner and outer mountain skirt surfaces 19 and 15, that is, the angle of the mountain-folded portion 14 is 180 degrees or less, preferably 90 degrees or less because the inner and outer mountain hem surfaces 19 and 15 need to be folded. Although the lower limit of the angle of the fold portion 14 is not particularly limited, the fold portion 14 approaches the front surface 9 as the angle decreases, so that the angle is determined within a range where the fold portion 14 does not abut the front surface. I do. In this case, the presence of the space formed by providing the front groove 2 has an advantage that the angle of the mountain fold 14 can be reduced.
[0016]
In the structure in which the auxiliary bottom surface 20 of the auxiliary groove portion 18 in the vertically integrated auxiliary reinforcing members 10 and 11 is joined to the groove bottom surface 13 of the front groove portion 2 in a contact state, even if only the auxiliary bottom surface 20 is bonded to the groove bottom surface 13, The same applies to the case where the end of the mountain skirt surface 19 is joined to the groove bottom surface 13. For this reason, as shown in FIG. 2, for example, upper and lower auxiliary reinforcing members 4 and 4 are used, and an inscribed surface portion 23 which is bent and extended as an end of the inner skirt surface 19 of each auxiliary reinforcing member 4 is formed into a front groove portion 2. The same operation and effect as those described above can be obtained even when they are joined to the groove bottom surface 13 in a contact state.
[0017]
When the main reinforcing member 6 is not provided with a front groove, as shown in FIG. 3, the integral auxiliary reinforcing member 5 has a pair of contacting convex portions 24 protruding toward the front surface 9 and a pair of inner skirt surfaces. It is preferable that the contact surface protruding portion 24 is joined to the inside of the front surface 9 in a contact surface state. If the auxiliary reinforcing members 7, 7 are separate types, as shown in FIG. 4, the contact surface convex portions 25, 25 formed individually from the ends of the inner mountain skirt surface 19 of each auxiliary reinforcing member 7, respectively, are inward on the front side. It is good to join in contact.
[0018]
According to the present invention, (1) an auxiliary reinforcing member erected on the upper and lower side surfaces from the front surface or the front groove in the main reinforcing member is composed of a mountain bent portion sandwiched between inner and outer mountain skirt surfaces, and (2) an impact is applied to the front surface of the main reinforcing member. When it is received, the inner and outer mountain bottom surfaces are folded around the mountain bent portion to prevent the upper and lower side surfaces from being opened. In other words, as long as it has a cross-sectional structure that satisfies the above two points (see FIGS. 1 to 4), the structure of the main reinforcing member and the integral or separate type of the auxiliary reinforcing member may be freely set.
[0019]
In the cross-sectional structure, the main reinforcing member 3 of the present invention may have the auxiliary reinforcing member 1 provided on the front surface 9 or the front groove portion 2 and the upper and lower side surfaces 10 and 11, and the auxiliary reinforcing member 1 extends from the main reinforcing member 3. It does not matter whether it is long or short in the existing direction (for example, the direction perpendicular to the plane of FIG. 1). From now on, usually the auxiliary reinforcing material 1 having the same length as the main reinforcing material 3 is used as shown in FIG. 5, but as shown in FIG. 6, for example, the auxiliary reinforcing material which is short in the extending direction of the main reinforcing material 3 is used. 8 may be provided intermittently. The auxiliary reinforcing member 1 (FIG. 5) having the same length as the main reinforcing member 3 can equally receive the effect of preventing the upper and lower side surfaces 10 and 11 from being opened by the auxiliary reinforcing member 1 regardless of which impact is applied to the front surface 9. However, even in the case of the short auxiliary reinforcing members 8 (FIG. 6), the adjacent auxiliary reinforcing members 8, 8 suppress the opening of the upper and lower side surfaces 10, 11 by appropriately determining the interval between the auxiliary reinforcing members 8, 8. In addition, the necessary and sufficient structural strength and shock absorbing performance can be improved. Furthermore, when the short auxiliary reinforcing material 8 is used, there is also an effect that the material can be saved.
[0020]
The deformation of the main reinforcing member 3 shown in FIG. 1 will be described. When the impact F is applied from the front surface 9, as shown in FIG. 7, the front surface 9 retreats so as to be recessed rearward about the front groove 2 (displaces rightward in FIG. 7). Similarly, the upper and lower side surfaces 10 and 11 also try to retreat, but the retraction of the upper and lower side surfaces 10 and 11 that is compressively deformed is smaller than the front surface 9 and tends to open in the vertical direction (vertical direction in FIG. reference). Here, the inner and outer skirt surfaces 19 and 15 of the auxiliary reinforcing material 1 try to retreat following the front groove portion 2 or the upper and lower side surfaces 10 and 11 respectively joined, so that the mountain bent portion 14 relatively advances. Become.
[0021]
As a result, the auxiliary reinforcing member 1 folds the inner and outer mountain bottom surfaces 19 and 15 around the mountain bent portion 14 as an axis. Here, if the inner mountain skirt surface 19 is separated from the groove side surface 12 of the front groove portion 2 to form a tilting margin, the inclination of the inner mountain skirt surface 19 toward the relative groove side surface 12 (the groove side surface 12). As a result, the bent portion 14 is allowed to approach (deformation approaching), and the broken portion 14 can relatively advance (positionally displace) relative to the inner and outer mountain bottom surfaces 19 and 15. In other words, if there is no tilting allowance, the mountain bent portion 14 becomes difficult to move forward, and the outer mountain bottom surface 15 may tilt outward (up and down in FIG. 7) about the mountain bent portion 14 as an axis. Even if there is no tilting allowance, the inner and outer mountain skirt surfaces 19 and 15 may be folded, but it is important to secure the tilting allowance of the inner mountain skirt surface 19 to surely guide the folding. In this way, the upper and lower side surfaces 10, 11 are prevented from being opened by being pulled inward by the outer mountain skirt surfaces 15, 15 which are folded (tilted) inward.
[0022]
【Example】
A bumper reinforcing material having an open cross-sectional structure (see FIG. 1, Example) and a bumper reinforcing material having a closed cross-sectional structure (see FIGS. 8 and 9, Comparative Examples 1 and 2) in terms of shock absorbing performance are provided. For comparison, a pole collision test and a plane collision test by computer simulation were performed for each.
[0023]
The embodiment is a bumper reinforcing member having an open sectional structure in which an auxiliary reinforcing member 1 integrated vertically and vertically is attached to a main reinforcing member 3 having an open sectional structure having a front groove 2 (FIG. 1). Thickness t = 1.6 mm, cross-sectional outline = 120 mm (upper and lower side widths) × 68 mm (front to back ribs), length in the extending direction (width as a bumper) = 780 mm, opening in front groove 2 = 30 mm, groove The bottom width is 20 mm, the depth is 18 mm, and the total weight is 7.52 kg.
[0024]
Comparative Example 1 is a bumper reinforcing member (FIG. 8) having a closed cross-sectional structure in which a back groove 28 is provided, and a reinforcing rib 29 extending from the back groove 28 to the front surface 9 is formed. = 120 mm (upper and lower side widths) x 68 mm (front to back), length in the extending direction (width as a bumper) = 780 mm, opening of the back groove 28 = 30 mm, groove bottom width = 20 mm, depth = 15 mm, It weighs 7.54 kg.
[0025]
Comparative Example 2 is a bumper reinforcement (FIG. 9) having a closed cross-sectional structure in which a contact surface protruding portion 31 protruding from the back surface 30 toward the front surface 9 (FIG. 9). The side width) × 68 mm (front to back), the length in the extending direction (width as a bumper) = 780 mm, the opening of the protruding surface 31 is 30 mm, the bottom of the protruding surface = 24 mm, and the total weight is 7.57 kg. is there.
[0026]
First, a pole collision test was performed on the example and comparative examples 1 and 2. Specifically, an impact (load) F with a vehicle weight of 1,300 kg and a speed of about 8.0 km / h is partially applied from the front of each bumper reinforcement, and the impact F causes the front to face rearward. (Mm) and the load (kN) that can be absorbed for each displacement amount were calculated. Since it is a pole collision, it can be imagined that only a partial deformation of the bumper reinforcing material occurs, and a difference in shock absorbing performance mainly appears as a difference in cross-sectional structure.
[0027]
The test results are shown in the graph showing the load-displacement curve in FIG. As is clear from this graph, Comparative Examples 1 and 2 having a closed cross-sectional structure show a higher load than the example at a displacement of 40 mm or less, but buckling occurs when the displacement reaches 40 mm. And cannot absorb shock. On the other hand, the example exhibited substantially constant shock absorption from a displacement of 20 mm, and exhibited stable shock absorption performance up to a displacement of 50 mm. Since the total load absorption that can be absorbed by the bumper reinforcing material is proportional to the area of the graph, it can be seen that the Examples and Comparative Examples 1 and 2 exhibit impact absorption performance that is not much different from the total load absorption.
[0028]
Next, the examples and the comparative examples 1 and 2 were subjected to a plane collision test. Specifically, an impact (load) F with a vehicle weight of 1,300 kg and a speed of about 8.0 km / h is applied from the front of each bumper reinforcement, and the front faces rearward by the impact F. (Mm) and the load (kN) that can be absorbed for each displacement amount were calculated. Since this is a plane collision, a wide range of deformation is caused in the extending direction of the bumper reinforcing member, so that not only the sectional structure but also the overall shock absorbing performance of the bumper reinforcing member can be measured.
[0029]
The test results are shown in a graph showing a load-displacement curve in FIG. As is clear from this graph, the comparative examples 1 and 2 of the closed cross-sectional structure have a displacement amount of 50 mm compared to the case of the pole collision due to the back groove (Comparative Example 1) or the convex portion on the contact surface (Comparative Example 2). Up to the displacement amount of 50 mm, buckling occurs and the shock absorption performance is rapidly reduced. On the other hand, in the embodiment, the shock absorbing performance is exhibited up to the displacement amount of 60 mm, and the load that can be absorbed relatively slowly even after the displacement amount of 60 mm is reduced.
[0030]
As described above, the bumper reinforcing material having an open cross-sectional structure to which the present invention is applied does not necessarily exhibit characteristics that match the shock absorbing performance with the bumper reinforcing material having a closed cross-sectional structure (for example, the maximum value of the load that can be absorbed is different). However, it was confirmed that the bumper reinforcing material having the open cross-sectional structure, which was generally regarded as inferior to the bumper reinforcing material having the closed cross-sectional structure, had an effect of raising the shock absorbing performance to almost the same level.
[0031]
In each of the above tests, the deformation of the embodiment in proportion to the amount of displacement was represented by graphics, and the degree of opening of the upper and lower sides was confirmed. There was no. This clearly indicates that the effect of opening prevention by the auxiliary reinforcing material is working. From this, as described above, since the shock absorbing performance is similar, and particularly the load-displacement curves are close to each other, the bumper reinforcing material having the open cross-sectional structure of the present invention can be improved in terms of structural strength. You can see that it is approaching.
[0032]
【The invention's effect】
Advantageous Effects of Invention According to the present invention, it is possible to provide a bumper reinforcing material having an open cross-sectional structure that is not inferior to a bumper reinforcing material having a closed cross-sectional structure in structural strength and shock absorbing performance. This largely depends on the auxiliary reinforcing material consisting of the inner and outer mountain bottom surfaces sandwiching the mountain bend. If the front surface of the bumper reinforcing material (main reinforcing material) is not deformed, the upper and lower side surfaces can be restrained with respect to the front surface only by bridging the straight members from the front surface to the upper and lower side surfaces, and the opening can be prevented. However, since the front surface of the actual bumper reinforcing material (main reinforcing material) is not uniform and deformed, there is a possibility that the linear member pushes the upper and lower side surfaces in some cases. The auxiliary member according to the present invention is provided with a mountain-folded portion that is not directly affected by an impact, and the inner and outer mountain skirts that are relatively inclined are folded around the mountain-folded portion, so that the front surface of the bumper reinforcing material (main reinforcing material) is formed. This has the effect of preventing the upper and lower side surfaces from opening due to the inclination of the outer skirt surface while allowing the deformation of the outer mountain.
[0033]
As described above, the auxiliary reinforcing member joins each end of the inner and outer crests to the front surface and upper and lower side surfaces.In this case, if the contact surface portion formed by extending the end portion is inscribed and joined, the front or upper and lower side surfaces are The rigidity can be increased. In particular, in a bumper reinforcing material having a front groove portion on the front surface, the auxiliary groove portion of the vertically integrated auxiliary reinforcing member is formed similarly, and the auxiliary bottom surface of the auxiliary groove portion is joined to the groove bottom surface of the front groove portion in a contact state. Thus, the rigidity of the front surface that normally receives an impact can be further increased. In addition, the combination of the bumper reinforcing material and the auxiliary reinforcing material for joining the grooves has an advantage that the positioning of the auxiliary reinforcing material with respect to the bumper reinforcing material is facilitated.
[0034]
In addition, the bumper reinforcement with the open cross-section structure saves material and is easy to reduce weight compared to the bumper reinforcement with the closed cross-section structure, and has a high degree of freedom in mounting on the vehicle body because the back side is open. There were practical benefits. However, since the structural strength or the shock absorbing performance is inferior to that of the bumper reinforcing material having a closed cross-sectional structure, the conventional bumper reinforcing material having an open cross-sectional structure has not been used in many cases by taking advantage of the high degree of freedom of mounting. The present invention has a significant effect in overcoming the drawbacks of the conventional open-section bumper reinforcement and making the advantages of weight reduction and mounting flexibility more widely available.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an example in which a vertically integrated auxiliary reinforcing material is used as a bumper reinforcing material having a front groove.
FIG. 2 is a cross-sectional view illustrating an example in which upper and lower separate auxiliary reinforcing members are used for a bumper reinforcing member having a front groove.
FIG. 3 is a cross-sectional view illustrating an example in which a vertically integrated auxiliary reinforcing material is used as a bumper reinforcing material without a front groove.
FIG. 4 is a sectional view showing an example in which upper and lower separate auxiliary reinforcing members are used for a bumper reinforcing member without a front groove.
FIG. 5 is a partial perspective view of an example using an auxiliary reinforcing material having the same length as a bumper reinforcing material.
FIG. 6 is a partial perspective view of an example in which a plurality of short auxiliary reinforcing members are used for a bumper reinforcing member.
FIG. 7 is a cross-sectional view corresponding to FIG. 1, illustrating a bumper reinforcing material deformed when an impact F is applied from the front side.
FIG. 8 is a cross-sectional view of a bumper reinforcing member having a closed cross-sectional structure in which a back groove is provided, and a reinforcing rib extending from the back groove to the front is formed.
FIG. 9 is a cross-sectional view of a bumper reinforcing member having a closed cross-sectional structure in which a contact surface protruding from the rear surface toward the front surface is formed.
FIG. 10 is a graph showing a load-displacement curve as a result of a pole collision test.
FIG. 11 is a graph showing a load-displacement curve as a result of a plane collision test.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Upper and lower integrated auxiliary reinforcing material 2 Front groove 3 Main reinforcing material 9 Front 10 Upper side 11 Lower side 12 Groove side 13 Groove bottom 14 Crest portion 15 Outer mountain bottom surface 18 Auxiliary groove portion 19 Inner mountain bottom surface 20 Auxiliary bottom surface 21 Contact surface 22 Outer bent edge 23 Inscribed surface

Claims (5)

A main reinforcing member having an open cross-sectional structure consisting of a front surface and upper and lower side surfaces, and auxiliary reinforcing members erected from the front surface of the main reinforcing member to the upper and lower side surfaces, respectively, and the auxiliary reinforcing material is a mountain bent portion having a convex cross section toward the front surface. Bumper reinforcement formed by forming. 2. The bumper reinforcing material according to claim 1, wherein the main reinforcing material has a front groove having a concave section formed of a groove bottom surface and a groove side surface on a front surface, and auxiliary reinforcing members are provided on the upper and lower side surfaces from the front groove portion. 3. The bumper reinforcing material according to claim 2, wherein the auxiliary reinforcing material joins an end of the inner mountain skirt surface of the inner and outer mountain skirt surfaces sandwiching the mountain bent portion to a groove bottom surface, and joins an end of the outer mountain skirt surface to upper and lower side surfaces. 3. The bumper reinforcing material according to claim 2, wherein the auxiliary reinforcing material has a mountain-folded portion close to a groove side surface of the front groove portion. The auxiliary reinforcing member is a vertically integrated member in which an auxiliary bottom is provided at the end of the pair of inner mountain skirts to form an auxiliary groove, and the groove bottom of the front groove and the auxiliary bottom of the auxiliary groove are in contact with each other. The bumper reinforcing material according to claim 2, wherein

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