JPH0891154A - Bumper stay - Google Patents

Abstract

PURPOSE: To absorb a large quantity of collision energy without causing a sharp change and reduction in a load by starting collapse by a comparatively small bending deformation load, and checking bending deformation by an intermediate vertically arranged rib at this collapse time. CONSTITUTION: A bumper stay is arranged between a bumper and a side member, and absorbs collision energy by collapsing, and is provided with a front vertically arranged rib 1 and a rear vertically arranged rib 3 arranged so as to cross at a right angle to the collision direction, a pair of first and second horizontally arranged ribs 4 and 5 to connect the front vertically arranged rib 1 and the rear vertically arranged rib 3 to each other and an intermediate vertically arranged rib 2 connected between these horizontally arranged ribs 1 and 3. Connecting parts between the front and rear vertically arranged ribs 1 and 3 and the first and the second horizontally arranged ribs 4 and 5 are formed in a cross-sectional shape curved in a radius not less than three times a plate thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bumper stay which is provided between a bumper and a side member and absorbs collision energy by crushing.

[0002]

2. Description of the Related Art Nowadays, demands for cost reduction and diversification of automobiles are becoming strict, and as one means for overcoming such conflicting demands, a common underbody is used for automobiles having different lengths. Is being promoted. Generally, the above-mentioned commonization produces the underbody side member 51 corresponding to the vehicle having the shortest vehicle length as shown in FIGS.
It is designed to be carried out by mounting 1 on derivative vehicles having different vehicle lengths. Therefore, when the side member 51 is mounted on a derivative vehicle having a long vehicle length, the bumper 52 and the side member 5 arranged at the front end portion and the rear end portion of the vehicle body.
A gap will be generated between 1 and 1.

Since the above-mentioned gap hardly contributes to energy absorption at the time of collision, if the gap is left unattended,
This will increase the damage to the car body during a collision. Therefore,
Conventionally, a bumper stay 53 such as an energy absorbing box is formed by bending and welding an iron plate or extruding an aluminum shape member so that the cross-sectional shape becomes a day shape or a rice field shape. It is designed to minimize damage to the vehicle body during a collision.

[0004]

By the way, the bumper stay 53 is designed so that the impact due to the collision transmitted to the vehicle body side of the side member 51 or the like is minimized.
It is desired that a large amount of energy is absorbed by a small collision load by gradually deforming and collapsing during a collision. However, in the bumper stay 53 having a cross section of a Japanese or rice field shape, as in the above-described conventional case, when a plane collision occurs, the buckling load of a plurality of ribs arranged parallel to the collision direction determines the initial load. Therefore, the collision load becomes relatively large, and all the ribs buckle at the same time to sharply reduce the load, resulting in a small energy absorption amount (see FIGS. 6 and 7). . Further, when the bumper stay 53 is formed by bending and welding an iron plate, the number of parts is increased and the number of manufacturing steps is also increased.

Therefore, the first object of the present invention is to provide a bumper stay having a large amount of energy absorption with a small collision load, and further to provide a bumper stay which can be formed with a small number of parts and steps. This is the second purpose.

[0006]

In order to solve the above-mentioned object, it is provided between a bumper and a side member and absorbs collision energy by crushing and has the following characteristics.

That is, a front vertical rib and a rear vertical rib arranged so as to be orthogonal to the collision direction, and a pair of horizontal ribs connecting the front vertical rib and the rear vertical rib, And an intermediate vertical rib connecting the horizontal ribs. The connecting portions of the front and rear vertical ribs and the horizontal ribs are characterized in that they are formed in a cross-sectional shape that is curved with a radius of three times or more the plate thickness of the horizontal ribs. Further, the horizontal rib is formed in a cross-sectional shape that is curved by a bending amount that is three times or more the plate thickness.

The bumper stays are preferably formed by extruding an aluminum profile. Further, it is desirable that engagement surfaces that are held by the bumper and the side member are provided on the attachment surfaces of the front vertical rib and the rear vertical rib to the bumper and the side member. Further, it is desirable that the front vertical ribs and the rear vertical ribs have through-holes that are used at the time of attachment to the bumper and the side members, and that are formed outside the connection portion with the horizontal ribs.

[0009]

According to the above construction, the connecting portions between the front and rear vertical ribs and the horizontal ribs are curved with a radius of three times or more the plate thickness of the horizontal ribs, or the horizontal ribs have a plate thickness of Since it is bent with a bending amount of three times or more, crushing is started by a relatively small bending deformation load. At the time of this crushing, the intermediate vertical ribs act to prevent bending deformation, so that the load does not decrease. Therefore, it is possible to absorb a large amount of collision energy without causing a large fluctuation and reduction in load.

Further, when it is formed by extruding an aluminum profile, it becomes possible to manufacture with a small number of parts and steps. Further, when the engaging members are provided on the mounting surfaces of the front vertical ribs and the rear vertical ribs, work such as bolt tightening is not required when mounting to the bumper or the like, and workability is improved. . Further, when the through holes are formed outside the connecting portions of the front vertical ribs and the rear vertical ribs with the horizontal ribs, work such as bolt tightening can be performed outside the bumper stay, so workability is improved. It will be improved.

[0011]

【Example】

[Embodiment 1] An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 2, the bumper stay according to the present embodiment is provided between the bumper 21 and the side member 22, and is made of an aluminum material so that it can be manufactured with a small number of parts and steps. It is formed by extrusion processing. Also, the bumper stay 20
The cross-sectional shape is set so that it gradually deforms and collapses in the event of a collision, and the front vertical ribs and rear vertical ribs and the front vertical ribs and rear vertical ribs are arranged so as to be orthogonal to the collision direction. A pair of horizontal ribs connecting the horizontal ribs and an intermediate vertical rib connecting the horizontal ribs, wherein the connecting portions between the front and rear vertical ribs and the horizontal rib are plates of the horizontal ribs. It is formed in a cross-sectional shape that is curved with a radius that is three times the thickness or more.

That is, as shown in FIG. 1, the bumper stay 20 has a front vertical rib 1, an intermediate vertical rib 2 and a rear vertical rib 3 which are orthogonal to the collision direction, on the collision side (the bumper in FIG. 2). 21 side) in this order. Front vertical rib 1
One ends of the first horizontal ribs 4 and the second horizontal ribs 5 parallel to the collision direction are connected to both ends of, respectively,
The other ends of the first horizontal rib 4 and the second horizontal rib 5 are connected to both ends of the rear vertical rib 3.

All the corners of the bumper stay 20, which is a connecting portion between the front and rear vertical ribs 1 and 3 and the first and second horizontal ribs 4 and 5, have initial irregularities. The curved portions 20a ... Are formed. These bends 2
0a ... The radius R is set to be 3 times or more the plate thickness of the first and second lateral ribs 4 and 5, and when the bumper stay 20 is crushed by being given collision energy, it is bent and deformed. It is designed to reduce the maximum load. Also, the first
Both ends of the intermediate vertical rib 2 are connected to central portions of the horizontal rib 4 and the second horizontal rib 5, respectively.
Is designed to prevent a decrease in load after the first horizontal rib 4 and the second horizontal rib 5 buckle.

On the mounting surfaces of the front vertical rib 1 and the rear vertical rib 3 to the bumper 21 and the side member 22, the engaging members 6 held by the bumper 21 and the side member 22 are dispersed in four directions. Are arranged.
Each engagement member 6 is formed in a T-shape including a support portion 6b fixed to the mounting surface and a head portion 6a provided on the top of the support portion 6b.

On the other hand, as shown in FIG. 3, the side member 2
In the mounting position of the bumper stay 20 in No. 2, the fitting opening portions 7 ... Are formed at positions corresponding to the above-mentioned engaging members 6 ... Also has a passage opening portion 7a having a large opening area and an engagement opening portion 7b having an opening area larger than the support portion 6b of the engaging member 6 and smaller than the head portion 6a. The engaging member 6 and the fitting opening 7 are engaged with each other and fixed, so that the bumper stay 20 can be attached to the side member 22 without performing work such as bolting. . In addition, the fitting port portion 7 ...
Is also formed on the bumper 21, and is also used when the bumper stay 20 is attached to the bumper 21.

Although the bumper stay 20 has the engaging member 6, the bumper stay 20 is not limited to this.
As shown in FIG. 5, through holes (not shown) may be formed in the mounting surfaces of the front vertical ribs 1 and the rear vertical ribs 3, and the front vertical ribs 1 and the rear vertical ribs 3 may be mounted to the side member 22 and the bumper 21 by bolts or the like. In addition, as described in Example 2 described later, the through hole has the first and second lateral ribs 4.
The front vertical ribs 1 and the intermediate vertical ribs 2 may be formed on the outer side of the connection portion with 5.

In the above structure, the bumper stay 20
The operation of will be described. As shown in FIG. 1, when collision energy is applied to the front vertical ribs 1 of the bumper stay 20, the collision energy is applied to the front vertical ribs 1.
And it is distributed and given to the 1st and 2nd horizontal ribs 4 and 5 pinched | interposed by the rear vertical rib 3. On this occasion,
The curved portion 20a connecting the front and rear vertical ribs 1 and 3 and the first and second horizontal ribs 4 and 5 includes the first and second curved ribs 20a.
It is curved with a radius R that is three times or more the plate thickness of the horizontal ribs 4.5. Therefore, the first and second lateral ribs 4 and 5 start buckling deformation from the curved portion 20a and are crushed.
Further, at the time of this crushing, the intermediate vertical ribs 2 act to prevent buckling deformation, so that a large amount of collision energy is absorbed without causing a large fluctuation or reduction in load.

Next, the crushing characteristics of the bumper stay 20 having the structure of this embodiment are compared with the crushing characteristics of the bumper stays having the conventional Japanese-shaped and T-shaped cross-sectional shapes to compare the crushing characteristics of this embodiment. The effectiveness of the energy absorption of stay 20 was investigated.

First, as shown in FIG. 4, a crushing property was investigated by conducting a test for applying a compressive force to the bumper stay 20 of this embodiment. As a result, as shown in FIG. 5, the load rapidly increases in the crushing range of 0 to 5 mm, and after the increased load becomes substantially constant in the crushing range of 5 to 20 mm, the load gradually decreases in the crushing range of 20 mm and thereafter. It turned out to increase.

Next, the conventional Japanese and rice field bumper stays were crushed and the crushing characteristics of each were investigated. As a result, in the case of a bumper stay having a Japanese cross section, as shown in FIG.
As shown in, it was revealed that a load peak occurs at the initial stage of crushing, and thereafter the load sharply decreases. Further, in the case of a bumper stay having a cross section of a paddle shape, as shown in FIG.
As shown in Fig. 5, it was revealed that a load peak occurs at the initial stage of crushing, and after that, the load sharply decreases, and then the load peak and a sharp decrease again occur.

As a result, from the results of the above-mentioned investigation of the crushing characteristics, the bumper stay 20 having the structure of this embodiment shows a large load peak during the initial crushing and a large change in the load during the crushing, as in the conventional bumper stay. Since it did not occur, it was confirmed that it gradually deforms and collapses at the time of collision and absorbs a large amount of collision energy with a small collision load.

[Embodiment 2] Another embodiment of the present invention will be described with reference to FIGS. The bumper stay according to the present embodiment is formed by extruding an aluminum shape member so that the bumper stay can be manufactured with a small number of parts and the same number of steps as in the first embodiment. The bumper stay includes a front vertical rib and a rear vertical rib arranged so as to be orthogonal to the collision direction, and a pair of horizontal ribs connecting the front vertical rib and the rear vertical rib,
An intermediate vertical rib connecting the horizontal ribs is formed, and the horizontal rib is formed in a cross-sectional shape curved by a bending amount that is three times or more the plate thickness.

That is, as shown in FIG. 9, the bumper stay has a front vertical rib 11, an intermediate vertical rib 12 and a rear vertical rib 13 which are orthogonal to the collision direction in this order from the collision side. There is. The first horizontal rib 14 and the second horizontal rib 1 are provided on one end side and the other end side of the inner side surface of the front vertical rib 11.
5, one end of each of the first horizontal ribs 14 and the second horizontal ribs 15 is connected to one end side and the other end side of the inner side surface of the rear vertical rib 13, respectively. There is.

The above-mentioned first and second lateral ribs 14 and 15
Is curved so that the central portion is convex outward, and the amount of curvature L, which is the difference between the end portion and the central portion, is set to be three times or more the plate thickness of the bumper stay 30. The first and second horizontal ribs 14 and 15 are provided on the bumper stay 3
When the collision energy is applied to 0 and it collapses, it bends and deforms and the maximum load is reduced. Also,
Both ends of the intermediate vertical rib 12 are connected to central portions of the first horizontal ribs 14 and the second horizontal ribs 15. The intermediate vertical ribs 12 include the first horizontal ribs 14 and the second horizontal ribs 12. It is designed to prevent a decrease in load after the installation rib 15 buckles.

Further, through holes 11a ... 13a ... through which bolts (not shown) are inserted are formed at both ends of the front vertical rib 11 and the rear vertical rib 13. Through hole 1
The forming positions of 1a ... 13a are set to be located outside the connection portion with the first and second horizontal ribs 14 and 15. For example, as shown in FIG. At the time of aligning and attaching to the attachment ports 17 ..., work such as bolt tightening is performed outside the bumper stay 30 to improve workability.

In the above structure, the bumper stay 30
The operation of will be described. As shown in FIG. 9, when collision energy is applied to the front vertical ribs 11 of the bumper stay 30, the collision energy is generated by the first and second vertical ribs 11 and 13 sandwiched by the front vertical ribs 11 and the rear vertical ribs 13. Second
It will be distributed and applied to the lateral ribs 14 and 15. At this time, the first and second horizontal ribs 14 and 15 are bent by a bending amount that is three times or more the plate thickness, and crushing is started by bending deformation with a small bending deformation load. Then, at the time of this crushing, the intermediate vertical ribs 2 act to prevent bending deformation, so that a large amount of collision energy is absorbed without causing a large fluctuation and reduction in load.

In the bumper stay 30, the connecting portions between the front and rear vertical ribs 11 and 13 and the first and second horizontal ribs 14 and 15 have the through holes 11a ... 13a. However, the present invention is not limited to this, and as shown in FIG. 11, both ends of the front and rear vertical ribs 11 and 13 and the first and second horizontal ribs 14 and 15 are provided. Both ends may be connected to each other. Further, as described in the first embodiment, engaging portions may be provided on the mounting surfaces of the front vertical ribs 11 and the rear vertical ribs 13.

[0028]

As described above, according to the present invention, the front vertical ribs and the rear vertical ribs, which are arranged so as to be orthogonal to the collision direction, and the front vertical ribs and the rear vertical ribs are provided between the front vertical ribs and the rear vertical ribs. It has a pair of horizontal ribs connected to each other and an intermediate vertical rib connecting the horizontal ribs. And, the connecting portions of the front and rear vertical ribs and the horizontal ribs are formed in a sectional shape curved at a radius of three times or more the plate thickness of the horizontal ribs, or the horizontal ribs have a plate thickness of Since the cross-sectional shape is curved with a bending amount of three times or more, crushing is started by a relatively small bending deformation load, and the intermediate vertical ribs prevent bending deformation during this crushing. Since it works like this, the load does not decrease. As a result, it is possible to absorb a large amount of collision energy without causing a large change or decrease in load.

Further, since the bumper stay is formed by extruding an aluminum profile, it is possible to manufacture with a small number of parts and steps.

[Brief description of drawings]

FIG. 1 shows a first embodiment of the present invention and is a perspective view of a bumper stay.

FIG. 2 is an exploded perspective view showing a state in which a bumper stay is attached between a bumper and a side member.

FIG. 3 is an explanatory diagram showing a state in which a bumper stay is attached to a side member.

FIG. 4 is an explanatory diagram when investigating a crushing characteristic.

FIG. 5 is a graph showing crushing characteristics.

FIG. 6 is a graph showing crushing characteristics of a bumper stay having a Japanese cross section.

FIG. 7 is a graph showing the crushing characteristic of a bumper stay having a cross section of a paddle shape.

FIG. 8 is a perspective view of a bumper stay.

FIG. 9 is a perspective view of the bumper stay, showing the second embodiment of the present invention.

FIG. 10 is an explanatory view showing a state in which a bumper stay is attached to a side member.

FIG. 11 is a perspective view of a bumper stay.

FIG. 12 is an explanatory diagram showing a relationship between a side member and a bumper.

FIG. 13 is an explanatory view showing a mounting state of the bumper stay to the vehicle body.

[Explanation of symbols]

 1 Front Vertical Rib 2 Middle Vertical Rib 3 Rear Vertical Rib 4 First Horizontal Rib 5 Second Horizontal Rib 6 Engaging Member 7 Fitting Portion 11 Front Vertical Rib 12 Middle Vertical Rib 13 Rear Vertical Rib 20 Bumper stay 20a Curved part 21 Bumper 22 Side member

Claims (5)

[Claims] 1. A bumper stay, which is provided between a bumper and a side member and absorbs collision energy by being crushed, has a front vertical rib and a rear vertical rib which are arranged orthogonally to a collision direction. A front rib, a pair of horizontal ribs connecting the front vertical rib and the rear vertical rib, and an intermediate vertical rib connecting the horizontal ribs. The connection with the installation rib is
A bumper stay characterized by being formed in a cross-sectional shape that is curved with a radius that is three times or more the plate thickness of the horizontal rib. 2. In a bumper stay, which is provided between a bumper and a side member and absorbs collision energy by being crushed, a front vertical rib and a rear vertical rib which are arranged so as to be orthogonal to a collision direction. A rib, a pair of horizontal ribs connecting the front vertical rib and the rear vertical rib, and an intermediate vertical rib connecting the horizontal ribs. The horizontal rib has a plate thickness of 3 A bumper stay characterized by being formed in a cross-sectional shape that is curved with a bending amount that is twice or more. 3. The bumper stay according to claim 1, wherein the bumper stay is formed by extruding an aluminum shape member. 4. An engaging member held by the bumper and the side member is provided on a mounting surface of the front vertical rib and the rear vertical rib to the bumper and the side member. The bumper stay according to claim 1 or 2. 5. The front vertical ribs and the rear vertical ribs have through-holes formed outside the connecting portions with the horizontal ribs, which are used when mounting the bumper and the side members. The bumper stay according to claim 1 or 2, wherein.