JPH11268663A - Bumper fixing structure to vehicle frame - Google Patents

Abstract

(57) Abstract: A first bead 92 for reducing the initial maximum proof stress is formed on the front end side of a front frame 86 having a rectangular closed cross section extending in the front-rear direction of a vehicle body, over the entire circumference of the frame.
Left and right plane portions 58, 6 continuous behind the bead 92
6, a bumper fixing structure in which a front and rear portion of the second bead 90 having a continuous uneven shape is formed to connect the bumper reinforcement 30 to the front end of the front frame 86. The effect of the frame side structure can be fully obtained. A second node-like member for suppressing collapse of a frame closed section is disposed in the frame closed section in proximity to a first bead. The first knot-like member 10 is disposed in the front end opening of the frame 86, and the reinforcement 30 is fastened and fixed thereto by the weld bolt 31 and the nut 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bumper fixing structure for fixing, for example, a front bumper or a rear bumper to a frame having a closed cross section provided to extend in a predetermined direction of a vehicle.

[0002]

2. Description of the Related Art Generally, in a frame such as a front frame and a rear frame of a vehicle, when a compressive load is applied in an axial direction (extending direction) from a front end or a rear end of the frame at the time of a vehicle collision or the like, an initial stage is required. Reduces the shock initially felt by the occupant by starting to collapse under a not so large load, but once it begins to collapse, it collapses regularly and stably without bending, maintaining the largest possible collapse load Therefore, it is desirable that a sufficiently large collision energy can be absorbed.

[0003] A preferable crushing mode in which the frame is regularly and stably crushed in the axial direction to maintain a large crushing load is, for example, in the case of a frame having a rectangular closed cross section, four circumferentially extending flat surfaces extending in the axial direction. Each part is crushed and deformed so as to alternately repeat the unevenness in the axial direction at the crushing pitch specific to the frame, and two adjacent flat parts are crushed and deformed so that if one is concave, the other becomes convex. The mode to do is known.

Therefore, conventionally, various crush guide beads have been formed on a front frame of a vehicle to which the front bumper is fixed, and when the vehicle collides, the front frame receiving the input load from the front bumper crushes in a desired manner. Such is known. That is,
For example, Japanese Patent Application Laid-Open No. 61-287811, Japanese Patent Application Laid-Open
No. 305877, Japanese Utility Model Laid-Open No. 24777/1990 and the like disclose various shapes of guide beads arranged side by side on a frame so that the frame is crushed and deformed in a preferable crushing mode as described above at the time of a vehicle collision. There is disclosed an apparatus which is adapted to maintain a relatively large crushing load (average proof stress).

[0005] Further, for example, in Japanese Unexamined Patent Publication No. Hei 4-231268, a frame having a rectangular closed cross-sectional structure composed of upper, lower, left and right walls is disposed adjacent to each other across a corner.
One of the two walls is provided with a concave bead on one side and a bead extending in the circumferential direction on the other side, and when the compressive load is applied in the axial direction at the time of collision, the bead is first crushed, so that the maximum crushing load at the beginning of input (Initial maximum proof stress) is kept low to some extent.

Further, Japanese Patent Application Laid-Open No. Hei 8-324454 discloses a structure provided with both a bead for reducing the initial maximum proof stress and a bead for improving the average proof stress.

When the front bumper is fixed to the front frame of the above-mentioned conventional vehicle, it is common practice to integrally provide a flange bent right and left at the front end of the frame and to connect and fix the bumper to the flange. .

[0008]

However, the collision load applied to the bumper at the time of a vehicle collision does not always act in parallel to the axial direction of the frame. In the fixed structure, one of the right and left flanges of the frame is bent and deformed first in the early stage of the collision, and the input load is largely deviated toward the direction, and is not sufficiently transmitted to the frame side. Therefore, in this case, even if various guide beads are provided on the frame side as described above, the frame cannot be deformed in a suitable collapse mode as intended, and the initial load is reduced and the collision energy is absorbed. There is a possibility that the function is not sufficiently exhibited.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to reduce the initial load by devising so that the collision load is sufficiently transmitted from the bumper side to the frame side. And the like, to sufficiently bring out the effects of the frame side structure.

[0010]

In order to attain the above object, according to the present invention, there is provided a joint for reinforcing a frame in a closed section of a frame closer to a bumper than a crushed bead for reducing an initial load. And a bumper is connected to the knot-shaped member.

More specifically, according to the first aspect of the present invention, the vehicle has a corner portion between the flat portions adjacent in the circumferential direction, and has a closed cross-section frame extending in a predetermined direction of the vehicle. To
The frame comprises a concave ridge formed on one of two adjacent flat portions on both sides of the corner portion, and a convex ridge formed on the other side so as to be continuous with the concave portion via the corner portion. It is assumed that a first bead for reducing the initial maximum proof stress is provided, and a bumper fixing structure in which the bumper is connected and fixed to a frame on the outer end side of the vehicle with respect to the first bead. And, in the frame closed cross section on the vehicle outer end side with respect to the first bead,
A knot-like member joined to the inner peripheral surface of the frame and dividing the inside of the frame is provided, and the bumper is connected and fixed to the knot-like member.

According to this configuration, the load applied to the bumper at the time of the collision of the vehicle is first transmitted to the knot-like member provided in the closed section of the frame, so that the knot-like member does not shift to the outside of the frame. Transmitted to the frame.
In addition, the collapse of the closed cross-sectional shape of the front end of the frame is prevented by the knot-like member, so that the load transmitted from the bumper side can be sufficiently applied to the first bead.
The initial load can be reduced by crushing the first bead as intended.

Moreover, since the first bead is formed so as to be continuous through the corners of the frame, that is, over the corners, the initial maximum proof stress of the frame is sufficiently small. Since one bead has a concave stripe on one side and a convex stripe on the other side, the bead is prevented from being broken due to tension at the corner portion during crushing deformation and excess portion due to compression, and Adverse effects are avoided.

That is, the load at the time of the collision can be sufficiently transmitted to the frame side with a simple structure, and the effect of the frame side structure can be sufficiently extracted to reduce the maximum crushing load at the initial stage of the load input. .

According to the second aspect of the present invention, the node-like member according to the first aspect of the present invention is provided near the first bead. As a result, the load transmitted from the bumper side to the knot-like member is reliably and directly applied to the first bead, and the effect of reducing the initial load due to the collapse of the first bead is further increased, and the maximum is achieved as intended. Can be demonstrated.

According to the third aspect of the present invention, the first or second aspect is provided.
A bolt extending toward the bumper side is fixed to the node-like member in the described invention, and the bumper is fixed to the node-like member by the bolt and a nut screwed to the bolt from the bumper side. Configuration. This clarifies the connection structure between the knot-like member and the bumper.

According to a fourth aspect of the present invention, in the first aspect of the present invention, two knot-like members are provided side by side in the frame extending direction, and one of the two knot-like members is close to the first bead. On the other hand, a bolt extending toward the bumper is fixed to the other node-shaped member, and the bumper is connected to the node-shaped member by the bolt and a nut screwed to the bolt from the bumper side. The configuration is fixed to

In this configuration, a connection structure between the node-like member and the bumper is embodied. Further, the collapse of the closed cross-sectional shape of the frame is prevented by the two node members provided side by side. In particular, the closing of the frame in the vicinity of the first bead is performed by one of the node members disposed close to the first bead. The collapse of the cross-sectional shape can be reliably prevented. For this reason, the load transmitted to the knot-like member on the bumper side can be reliably applied to the first bead via the frame, so that the function of reducing the initial load by the first bead can be maximized. .

Further, even if one of the knot-like members is arranged close to the first bead, the other knot-like member can be arranged at a position outside the vehicle body outside end of the frame. The connection structure of the bumper to the member can be designed relatively freely.

According to a fifth aspect of the present invention, the first bead according to any one of the first to fourth aspects of the present invention is formed over substantially the entire periphery including all corners of the frame. As a result, all of the frame corners that are difficult to collapse
The bead facilitates crushing, and thus the crush initial maximum proof stress can be more effectively reduced.

According to the sixth aspect of the present invention, the first bead according to any one of the first to fifth aspects has a depth of one concave streak of two adjacent flat portions forming each corner. And the height of the other ridge are set substantially the same.

[0022] As a result, when the first bead is crushed, the compressive force acting on each corner of the first bead due to the deformation of the concave streak and the pulling force due to the deformation of the convex streak become substantially equal. Breakage due to tension in the portion and excess thickness due to compression are almost completely suppressed. Therefore, it is possible to reliably prevent the breaking or excess wall from hindering the crush deformation guide by the first bead.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects of the present invention, the frame flat portion on the inner side of the vehicle body with respect to the first bead extends along the frame extending direction. The second bead for improving the average proof stress in which the concave portion and the convex portion over the entire length of the substantially crushed pitch are alternately formed at the substantially crushed pitch is formed so as not to extend over the corners on both sides.

In this configuration, at the time of a vehicle collision, the second bead causes the frame to be crushed and deformed in the target crush mode without being bent and deformed regularly and stably at a substantially crushing pitch in the frame extending direction without being bent. This can lead to a higher average crush resistance and a stable higher crush resistance. Further, since the second bead is not formed at the corner of the frame, it is possible to prevent a decrease in the average crushing strength due to the corner being easily crushed, and in this regard, it is possible to secure a larger average crushing strength. it can.

According to the eighth aspect of the invention, the width of the first bead in the frame extending direction in the invention of the seventh aspect is set shorter than the crushing pitch of the second bead.

With this, in the cross section along the frame extending direction, the inclination angles of the concave and convex beads of the first bead along the frame extending direction are increased, so that the first bead has a larger inclination angle in the frame extending direction. The ease with which the concave and convex beads are crushed by the load is increased, and this also enables a greater reduction in the initial maximum crushing proof stress.

According to the ninth aspect of the present invention, the seventh aspect or the eighth aspect is provided.
The second bead in the described invention is formed continuously with the first bead in the frame extending direction or with an intermediate plane portion having a length that is an integral multiple of the crushing pitch with respect to the first bead. .

[0028] With this, the crush deformation of the intermediate plane portion between the first bead and the second bead is performed at the above-mentioned crush pitch, so that the second bead is in the first bead side end region of the second bead. According to the bead, the crush deformation can be started smoothly and reliably in the desired crush mode at the crush pitch.

According to the tenth aspect of the present invention, the seventh to ninth aspects are described.
The second bead in the invention described in any one of the above (1) to (3) is formed on two mutually opposing flat portions of the frame. Thereby, the crush deformation guide by the second bead can be performed more reliably.

In the eleventh aspect of the present invention, the two second beads opposed to each other in the tenth aspect of the invention are:
In the frame extending direction, when one is a concave portion, the other is a convex portion.

Thus, when the frame is crushed and deformed in the extending direction, no tension or compression occurs in the cross section at each position in the frame extending direction. Can be avoided. Therefore, it is possible to prevent the breakage and excess wall from hindering the crushing deformation guide by the second bead.

According to the twelfth aspect of the present invention, the seventh to first aspects are provided.
The second bead in the invention according to any one of the first to fifth aspects,
The second bead is formed in the remaining area obtained by subtracting at least the movement of the corner when the frame is crushed from the corners on both sides of the plane where the second bead is formed.

Thus, when the frame is crushed and deformed in the extending direction, there is no possibility that the corners (ridges) move to and enter the portion where the second bead is formed. Disturbance of crushing deformation due to entering can be avoided. Therefore, it is possible to prevent the movement of the corner from hindering the crushing deformation guide by the second bead.

According to a thirteenth aspect of the present invention, the second bead according to the twelfth aspect of the present invention is arranged such that the second bead is formed at about one-half of the crushed pitch from the corners on both sides of the flat part where the second bead is formed.
Is formed in the remaining range after subtracting the length.

That is, since the crushing of the frame is generally performed at each crushing pitch, the movement amount of the corner is at most １ of the crushing pitch. Therefore, in the present invention, the second bead is formed in the remaining area obtained by subtracting the length of about 1/2 of the crushing pitch from the corners on both sides of the flat part.
The operation according to the invention described in 2 can be reliably obtained.

According to the fourteenth aspect of the present invention, the first to sixth aspects are provided.
In the invention described in any one of the above, a reinforcing flat portion extending in the frame extending direction opposite to at least one flat portion of the frame is provided in a closed section of the frame closer to the inside of the vehicle body than the first bead. A reinforcing plate is provided, and a second bead for improving the average proof stress is provided on the reinforcing flat portion, in which concave portions and convex portions are alternately repeated along a substantially crushing pitch along the frame extending direction over the entire length of the crushing pitch. Is formed.

In this configuration, when the frame is crushed and deformed in the extending direction, the reinforcing plate provided in the frame is crushed and deformed in accordance with the second bead, and the crushing deformation of the reinforcing plate causes the frame to move as intended. It can be guided to be crushed and deformed in the crush mode. Therefore, a large average crushing strength can be ensured similarly to the invention of the seventh aspect.

[0038]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows an embodiment in which a bumper fixing structure C for a vehicle frame according to the present invention is applied to fixing a front bumper to a front frame of a passenger car. That is, the outside is the vehicle body, and the right back side is the rear, that is, the inside of the vehicle body. In addition,
Unless otherwise specified, the front, rear, left and right of the vehicle body are referred to as front, rear, left and right.

In FIG. 1, reference numeral 86 denotes a right front frame extending in the front-rear direction at a lower right portion of the front body of the vehicle body. As will be described later, the frame 86 is composed of a plurality of flat portions. The connecting portion has a closed cross section with a corner. The above frame 8
6, near the front end (outer end of the vehicle body)
A first bead 92 is provided for reducing the initial maximum proof stress of the first frame and reducing the initial load at the time of collision to some extent, and the flat portions 58 on both the left and right sides of the rear frame continuous with the first bead 92. , 66 (see FIG. 2) include the frame 8
6 to increase the average proof stress and sufficiently secure the amount of collision energy that can be absorbed.
Is provided.

In the closed cross section of the frame 86 that is continuous with the front of the first bead 92, the node-like members 10 and 20 for reinforcing the frame 86 so as to suppress the collapse of the closed cross section at the time of collision are provided. The front bumper reinforcement 30 is connected and fixed to the first first knot-like member 10 on the front side.

First, the configuration of the frame 86 and the mode of the collapsed deformation will be described in detail.

As shown in FIG. 2, the frame 86 is provided with a first panel 5 having a hat-shaped cross section and extending in the front-rear direction of the vehicle body.
0 and the second panel 52 are opposed to each other, and are flanges 50a, 52a joined to each other to form a double-hat type frame.
4, 56, 58, 60, 62, 64, 66, 68 (the flat portion 54 and the flat portion 62 are formed of two flanges 50a, 52
a), and eight corner portions 70, 72, 74, 76, 78, which are connecting portions between adjacent planar portions.
80, 82, and 84, each of which has a rectangular cross section and a closed cross section.

The flat portions 58 and 66 of the frame 86 which face left and right are respectively provided with a second portion for improving the average proof stress.
A bead 90 (only one is shown in the figure) is formed.
The second bead 90 is formed in the two flat portions 58 and 66 opposed to each other in a range not to cover the corners 72, 74, 80 and 82 on both sides of the flat portions 58 and 66. Corners 72, 74, 8 on both sides
It is formed in the remaining range obtained by subtracting a predetermined length H = P / 2 (P is a crushing pitch described below) from 0 and 82, respectively.

The second beads 90 formed on the two flat portions 58 and 66 are crushed at the crushing pitch P in the longitudinal direction of the vehicle body, that is, in the axial direction of the frame 86, as shown in FIG. The concave portions 90a and the convex portions 90b over the entire length of the pitch P are formed so as to form a continuous uneven shape that repeats alternately. In addition, these two plane portions 58, 6
6 have the same phase in the axial direction, that is, each crushed pitch area A in the axial direction.
In one of A1, A2,..., When one of the second beads is a concave portion 90a, the other second bead is a convex portion 90b.

The crushing pitch P is a value specific to the frame determined by the cross-sectional shape, thickness, material, and the like of the frame. For example, “Int. J. Impact Engng Vol. 4 No. 4 published in England in 1986. "DYNAMICPROGRESSIVE BUCKLING" described on pages 243 to 270 of "4."
Pages 243 and 2 of OF CIRCULAR AND SQUARE TUBES
On page 44, it is defined as "2H" (2H is one crushing pitch).

The second bead 90 in the frame 86
The first bead 92 for reducing the initial maximum proof stress over the entire circumference including all the corners 70, 72, 74, 76, 78, 80, 82, 84 of the frame 86 at a position continuous with the front end side of the frame 86.
Are formed. The first bead 92 has a concave streak 92a on one of two plane portions adjacent to each other with the corners therebetween.
On the other hand, it has a ridge 92b. More specifically, as shown in FIG. 4, in the flat portions 54 and 56 sandwiching the corner 70, a ridge is formed on the flat portion 54 (a bead in the flat portion 54 is a ridge when viewed from the corner 70). And
In the flat portions 56 and 58 forming the corner portions 72, the flat portions 56 and 58 forming the corner portions 72 are concave. , 60 are convex in the flat portion 58, so they are concave in the flat portion 60, and the flat portions 60, 62 forming the corners 76 are concave in the flat portion 60. A ridge is formed (the bead on the flat portion 62 is a ridge when viewed from the corner 76).

Further, the first bead 92 has a corner 78
Are formed in the flat portions 62 and 64 (the beads in the flat portion 62 are concave when viewed from the corner portions 78), so that the flat portions 64 form convex strips.
In the flat portions 64 and 66 forming the corner portions 80, the flat portions 64 are convex, so that the flat portions 66 are concave.
In the flat portions 66 and 68 forming the corner portions 82, the flat portions 66 are concave, so that the flat portions 68 form convex ridges.
In the flat portions 68 and 54 forming the corner portions 84, the flat portions 68 are convex streaks.
4, the bead in the flat portion 54 is concave.
Has made.

In the first bead 92, the width L2 of the frame 86 in the axial direction is set to be sufficiently smaller than the crushing pitch P, and two adjacent beads forming each corner of the frame 86 are formed.
One of the two flat portions is formed so that the depth Si of one of the ridges is substantially the same as the height So of the other ridge. Further, the first bead 92 is formed behind the front end of the frame 86 by a predetermined length Lf = {an integral multiple of P / 2 (P is a crushing pitch)}.

The second bead 90 is formed so that its rear end is separated from the rear end of the frame 86 by a predetermined length Lr = {an integral multiple of P / 2 (P is a crushing pitch)}. . Note that the rear end of the frame 86 is a portion where the substantially same cross section continues straight in the axial direction of the frame 86, that is, a rear end of a portion of the frame 86 which is about to be crushed to absorb a collision load. means.

With this configuration, when a load W is applied to the frame 86 from the front end toward the rear in the axial direction as shown in FIG. 3, first, as shown in FIG. 5 and FIG. The bead 92 is crushed and deformed. The first bead 92 is deformed so that the concave streak 92a becomes more concave and the convex streak 92b becomes more convex as shown in the figure. Then, after the first bead 92 is crushed, the frame portion behind the first bead 92 is moved to the second bead 92.
Guided by the bead 90, it is crushed and deformed as shown in FIGS. 7, 8, 9 and 10.

That is, each of the plane portions 54,
Each of 56, 58, 60, 62, 64, 66, 68 is crushed and deformed by repeating the unevenness alternately in the axial direction for each crushed pitch area A1, A2,.
Two flat portions adjacent to each other across the 72, 74, 76, 78, 80, 82, 84, for example, the flat portion 56 and the flat portion 58 adjacent to each other across the corner 72, have one in the same collapsed pitch region. If it is a concave part, it deforms so that the other part becomes a convex part.

The structure of the frame 86 is shown in FIGS.
The structure is not limited to the one shown in FIG. 10, and for example, as shown in FIG. 11, a single-hat type frame 86 including a hat-shaped cross-section panel and a cross-section straight panel may be used. Further, as shown in FIG. 12, each corner 70, 72, 74, 76 of the frame 86 is formed in a chamfered shape,
Between the first bead 92 and the second bead 90, an intermediate plane portion 91 having a length L3 which is an integral multiple of the crushing pitch P in the frame axis direction (1 in this modification) may be interposed.

Therefore, as described above, the first bead 92 for reducing the initial maximum proof stress is formed on the frame 86, and the first bead 92 is formed over the entire periphery of the frame including all corners. All of the corners that are hard to be crushed are easily crushed by the first bead 92, whereby the initial maximum proof stress can be reduced and the initial load at the time of collision can be sufficiently reduced.

Further, since the first bead 92 has a width L2 in the frame axis direction shorter than the crushing pitch P of the frame 86, as shown in FIG. 13, the first bead 92 has a cross section along the frame axis direction. The inclination angle α1 of the concave ridges 92a and the convex ridges 92b with respect to the axial direction becomes larger than the inclination angle α2 when the width in the axial direction is the crushed pitch P as shown by the broken line in FIG. When the load W is applied, the concave ridges 92a and the convex ridges 92b are easily crushed.
This also makes it possible to reduce the initial maximum proof stress and sufficiently reduce the initial load at the time of collision. For this reason, it is preferable that the width of the first bead 92 be set sufficiently small.

Further, by changing the shape of the first bead 92, it is possible to change the initial maximum proof stress of the crush and to adjust the crush deformation guide of the frame 86. That is,
Assuming that the thickness of the frame 86 is the same, the angle θ and the curvature R of the first bead 92 are changed as shown in FIG. 14. For example, if the curvature R is increased, the degree of stress concentration is reduced. The maximum proof stress can be increased, and if the angle θ is reduced, the component perpendicular to the frame axis direction of the force acting on the second bead 92 when an axial load is input is reduced, so that the initial maximum proof stress is reduced. Can be bigger.

Further, the first bead 92 has a concave streak 92a on one side and a convex streak 92b on the other side in two plane portions adjacent to each other across each corner of the frame 86. The depth of the concave ridge 92a and the convex ridge 92b
Are formed so as to have substantially the same height, so that when the first bead 92 is crushed, each corner of the first bead 92 is compressed by the deformation of the concave ridge 92a and is pulled by the deformation of the convex ridge 92b. And both act to cancel each other out. Thus, the first bead 92 can be prevented from being broken at each corner portion due to tension or excessively due to compression, so that the second bead 90 can be prevented from being adversely affected by the breakage or excessively large portion. In this manner, a desired crush mode to be guided can be realized, and a sufficiently large crush average strength can be secured.

A second bead 90 for improving the average proof stress is formed on each of the two flat portions 58 and 66 of the frame 86 facing each other, and the second bead 90 is crushed along the axial direction of the frame. In the pit P, the concave portion 90a and the convex portion 90b over the entire length of the collapse pitch P form a continuous uneven shape. For this reason, the frame 8
6 is guided by the second bead 90 at the time of a vehicle collision, is not regularly and stably bent at the crushing pitch P in the axial direction, and is deformed without remaining crushed in a crushing mode as intended, whereby a larger crushing average is obtained. The proof strength is ensured, and the higher crush strength can be stably maintained.

Further, since the second bead 90 is formed in the plane portions 58 and 66 so as not to cover the corners on both sides, it is possible to prevent a decrease in the average crushing strength due to the corners being easily collapsed. In this respect, a larger average crushing strength can be secured.

Further, since the second bead 90 is formed continuously to the first bead 92 in the frame axis direction, the second bead 90 is formed in the front end region of the second bead 90.
According to the bead 90, the deformation can be started smoothly and reliably at the crushing pitch P in the desired crushing mode. In addition, since the second bead 90 is formed on the two flat portions 58 and 66 of the frame 86 facing each other, compared to a case where the second bead 90 is formed on only one flat portion.
Collapse guidance by the second bead 90 is more reliably performed.

Further, the second bead 90 is formed such that if one of the two flat portions 58, 66 of the frame 86 is opposed to the other, the second bead 90 is a convex ridge 92b if one is a concave ridge 92a. When the frame 86 is crushed and deformed in the axial direction, no tension or compression occurs in a cross section perpendicular to the axial direction of each crushed pitch region. Therefore, the excess of the wall due to the breaking or the compression due to the tension is avoided, and the guide of the crushing deformation by the second bead 90 is not hindered.

In addition, the second bead 90 has a flat portion 5
1 / of the crushing pitch P from the corners on both sides of 8, 66
Since the frame 86 is formed in the remaining area after subtracting the length of the second bead, when the frame 86 is crushed and deformed in the axial direction, each corner moves to the second bead 90 and the second bead 90 is moved. Can be avoided. That is, since the crushing deformation of the frame 86 is performed for each crushing pitch P, the amount of movement of the corner becomes P / 2 at the maximum, and as described above, the moving distance of the corner is reduced by P / 2 from the corners on both sides. If the second bead 90 is formed, it is possible to reliably prevent the corner from moving to the area where the second bead 90 is formed.

Here, in order to confirm the effects of the first bead 92 and the second bead 90, the frame 86 shown in FIG. 11 and the frame of one of the conventional examples (Japanese Utility Model Laid-Open No. 24777/1990) are identical. FIG. 15 shows test results obtained by manufacturing a test frame formed of the same material and having the same size and shape, and examining the relationship between the amount of crushing and the load when crushing them under the same conditions.

As can be seen from the above test results, the provision of the first bead 92 and the second bead 90 allows the initial maximum proof stress to be sufficiently reduced even for frames of the same material, of the same size and of the same shape. The average proof stress can be further increased. In the case of a frame without any bead, the initial maximum proof stress rises greatly as shown by the broken line in the figure, and the average proof stress may be significantly reduced due to, for example, bending in the middle.

Next, as a characteristic portion of the present invention, a structure for fixing the front bumper reinforcement 30 to the frame 86 having the above-described structure will be described in detail with reference to FIG. 1 and FIGS. .

As shown in the above figures, the first node-like member 10 is slightly projecting from the opening at the front end of the frame 86.
Is provided. The first node-shaped member 10 has a partition 11 extending in a plane perpendicular to the frame axis direction, and the partition 11 extends in the left-right direction from the left plane 58 to the right plane 66. The left and right side walls 12 and 13 are bent at the right and left ends and extend rearward, and are integrally formed, and the upper and lower ends of the partition 11 are higher than the upper flat parts 56 and 82, respectively. The upper wall portion 14 and the bottom portion 15 are integrally formed by being bent backward at a slightly lower position and a slightly higher position than the lower flat portions 60 and 64, respectively. The left and right side wall portions 12 and 13 have upper and lower ends respectively formed of a frame 86.
Are bent inward and overlapped and joined (welded) to the upper wall portion 14 and the bottom portion 15, respectively, whereby the first knot-like member 10 is formed into a strong closed cross section.

The right side wall portion 13 of the first node-shaped member 10 is superposed on the right side flat portion 66 of the frame 86 from the inside, and is fixed to the flat portion 66 by two upper and lower bolts 16, 16. Has been concluded. On the other hand, the left side wall portion 12 is overlapped with the left side wall portion 22 of the second node-like member 20 on the left side flat portion 58 of the frame 86 from the inside, and the upper and lower bolts 17 22 and the flat portion 58.

The second node-like member 20 is disposed so as to be continuous with the front end side of the frame of the first bead 92, and extends vertically in the axial direction of the frame so as to partition the internal space of the frame 86 forward and backward. The right and left side walls 22 and 23 of the partition 21 and the left and right ends of the partition 21 are bent forward to extend forward. The right side wall portion 23 is overlapped on the right side flat portion 66 of the frame 86 from inside, and is fastened to the flat portion 66 by two upper and lower bolts 24, 24 (shown in FIGS. 17 and 18). And the side wall 2
3 is bent inward along the upper flat portion 82 of the frame 86. On the other hand, the left side wall portion 22 extends to the front end of the frame 86, and as described above,
Together with the left side wall 12 of the knotted member 10, it is fastened to the left flat portion 58 of the frame 86.

Further, in each of the above figures, reference numeral 26 denotes a tie-down hook used for fixing the vehicle to the floor when the vehicle is carried by a freight train or the like. The joining surface 26a is formed on the upper end of the tie-down hook 26 so as to substantially cover the entire right outer surface on the front end side of the frame 86 at the front end side with respect to the first bead 92.
The tie-down hook 26 is fastened and fixed to the frame 86 at its joint surface 26a. That is, the joining surface 26 of the tie-down hook 26
a is fastened to the right side wall portion 66 of the frame 86 together with the right side wall portion 13 of the first node member 10 by two upper and lower bolts 16, and the right side wall of the second node member 20. Together with the side wall 23 of the frame 86, the upper and lower bolts 24, 24 fasten and fix to the right side flat portion 66 of the frame 86.

In other words, the first knot-like member 10 and the second knot-like member 20 are overlapped with each other on the left side wall and fastened by the upper and lower two bolts 17, and the right side wall Are fastened together via the joining surface 26a of the tie-down hook 26 to be integrated. With this, the frame 86 on the front end side of the frame with respect to the first bead 92 is connected to the first joint member 10 and the second Nodal member 2
It is strongly reinforced by 0.

On the other hand, the partition 11 of the first node-shaped member 10
, Three weld bolts 31, 31, 31 extending substantially vertically forward from the partition 11 are provided. The base ends of the respective weld bolts 31 are joined to the partition wall 11 in a state where the weld bolts 31 penetrate from the rear side to the front side on the upper right side and the lower left and right sides of the partition wall 11, while the distal end is connected to the left and right of the vehicle body. Mounting surfaces 32 formed on both left and right ends of a resin reinforcement 30 extending between both ends.
(Only the right side is shown in the figure), and the above-described reinforcement 30 is fixed to the first node-like member 10 together with nuts 33, 33,.

In each of the drawings, reference numeral 34 denotes a bracket (not shown) for supporting the upper and lower ends of the bumper skin which is put on the reinforcement 30 from the front of the vehicle body.

Therefore, according to the bumper fixing structure C of the first embodiment, the collision load applied to the bumper at the time of the vehicle collision is transmitted from the reinforcement 30 to the first node-like member 10 provided in the closed section of the frame. So that
The light is sufficiently transmitted from the first node-shaped member 10 to the frame 86 without being shifted outward from the frame 86. This allows the collision load to be sufficiently transmitted to the portion of the frame 86 where the second bead 90 is formed with a simple configuration,
Since the frame 86 can be crushed and deformed in the intended crushing mode by the guidance of the second bead 90, the effect of improving the average crushing strength of the frame 86 by the second bead 90 as described above can be effectively exerted.

Further, the second node-like member 20 is connected to the first bead 92.
And the front ends of the first knot-like member 10, the second knot-like member 20 and the frame 86 are integrated, and the frame front end is strongly reinforced. Therefore, the collapse of the frame closed cross-sectional shape at that portion can be prevented, and the load transmitted from the bumper side can be sufficiently applied to the first bead 92. Thus, the first bead 92 can be crushed as intended, and the function of reducing the maximum crushing load at the initial input by the first bead 92 as described above can be maximized as designed.

Further, the second joint member 20 is connected to the first bead 9.
2, the first knot-like member 10 can be placed relatively freely, so that the connection structure of the bumper to this first knot-like member 10 can be designed relatively freely. In this embodiment, the first knot-like member 10
Are arranged at the front end of the frame 86, so that the first node-like member 10 and the reinforcement 30 of the bumper can be directly and firmly connected and fixed.

(Embodiment 2) FIG. 19 shows a bumper fixing structure C according to Embodiment 2 of the present invention.
Is similar to that of the first embodiment (see FIG. 1 and the like), and the same parts will be described with the same reference numerals.

In FIG. 19, reference numerals 10 and 20 denote knot-like members provided on the frame 86 in the same manner as in the first embodiment. The first knot-like member 10 has an in-plane perpendicular to the axial direction of the frame. A partition 11 that spreads out, and the partition 11
Are formed in a substantially U-shape by left and right side walls 12 and 13 whose right and left ends are bent and extend rearward. Then, the right side wall portion 1 of the first node member 10
3 is superposed from the inside on the right side flat portion 66 of the frame 86 and fastened by two upper and lower bolts (not shown), and the left side wall portion 12 is similar to the first embodiment.
Is superposed from the inside on the left flat part 58 of the frame 86 and is fastened by two upper and lower bolts 17. Further, as in the first embodiment, two weld bolts 31, 3 are provided on the partition 11 of the first knot-like member 10.
The steel reinforcement 30 is fastened to the first node-like member 10 by the weld bolts 31, 31 and the nuts 33, 33 respectively screwed to the weld bolts 31, 31 from the bumper side. Fixed.

Further, the second node-like member 20 is provided with the first bead 9.
A partition wall 21 that partitions the space in the frame 86 forward and backward at a position that is continuous with the front end side of the second frame 2, left and right side wall portions 22 and 23 where the partition wall portion 21 is bent at both left and right ends and extends forward; The partition 21 is provided with an upper wall 41 and a bottom 42 which are bent at both upper and lower ends and extend forward, respectively.
3 are bent at the upper and lower ends to the inside of the frame, respectively, are overlapped and joined (welded) to the upper wall portion 41 and the bottom portion 42, whereby the second node-like member 20 has a strong closed cross section. It is formed in a shape.

The right side wall portion 23 of the second node-like member 20 is superposed on the right side flat portion 66 of the frame 86 from inside, and the tie-down hook 26 is superposed on the flat side portion 66 from outside. Together with the joint surface 26a of the flat surface portion 66 by two upper and lower bolts 24, 24. Joint surface 26 of the tie-down hook 26
a is formed so as to cover about half of the rear side from the front edge of the first bead 92 to the front end of the frame 86,
Different from the first embodiment, the right side wall 13 of the first node-shaped member 10 does not overlap. On the other hand, the left side wall portion 12 of the second node-like member 20 is
Is joined (welded) to the left side flat portion 58 from the inside. That is, in this embodiment, the two knot-like members 10,
20 are individually fastened to the frame 86.

Therefore, according to the second embodiment, similarly to the first embodiment, the collision load applied to the bumper at the time of the vehicle collision is applied to the frame 86 via the first node-shaped member 10 provided in the closed section of the frame. In this case, the first bead 92 can sufficiently reduce the maximum crushing load at the initial stage of input, and the second bead 90 can improve the average crushing resistance of the frame 86 by the second bead 90. It can be used effectively. Further, the connection structure of the bumper to the first node-shaped member 10 can be designed relatively freely.

(Other Embodiments) The present invention is not limited to the first and second embodiments, but encompasses various other embodiments. That is, in the first and second embodiments, two knot-like members are provided and the second knot-like member 20 is provided.
Is arranged close to the first bead 92 while the first knot-like member 1
0 is arranged at the front end of the frame 86, and the bumper reinforcement 30 is connected to the front end of the frame 86, but is not limited thereto. That is, for example, FIG.
As shown in FIG. 7, a bracket provided with one knot-like member 20 'disposed close to the first bead 92 similarly to the second knot-like member 20, and provided on this knot-like member 20' so as to extend from the reinforcement 30. 35 may be connected.

In this manner, the load transmitted from the bumper side to the knot-like member 20 'is reliably and directly applied to the first bead 92, so that the initial maximum proof stress due to the collapse of the first bead 92 is obtained. The reduction effect can be maximized as intended.

In the first and second embodiments, the present invention is applied to the structure for fixing the front bumper to the front frame of the vehicle. However, the invention is not limited to this, and for example, the structure for fixing the rear bumper to the rear frame of the vehicle. May be applied.

Further, the structure of the frame to which the present invention is applied is not limited to those of the first and second embodiments. That is, in the first and second embodiments, the second beads 90 are formed on the flat portions 58 and 66 on both the left and right sides of the frame 86. However, the present invention is not limited to this. For example, as shown in FIG. Are given the same reference numerals), frame 8
A pair of left and right reinforcing plates 9 extending in the frame axis direction inside 6
6 and 98, and a crush guide bead similar to the second bead 90 of the first and second embodiments is formed on the reinforcing flat portions facing the frame flat portions 58 and 66 of the reinforcing plates 96 and 98, respectively. Is also good.

With this configuration, when the frame 86 is crushed and deformed in the axial direction by receiving a compressive load from the bumper, the reinforcing plates 96 and 98 provided in the frame 86 follow the crush bead. Since the crushing deformation occurs, the crushing deformation of the reinforcing plates 96 and 98 can guide the frame 86 to crush and deform in a desired crushing mode. Therefore, a large average crush resistance can be ensured similarly to the frame 86 of the first and second embodiments.

In the first and second embodiments, the first bead 92 and the second bead 90 formed on the frame 86 are also formed on the upper apron panel and the lower frame lower panel to which the frame 86 is attached. You may make it. In this way, when the frame 86 is crushed and deformed, the surrounding panels can be deformed in the same crushing mode as the frame 86, so that the crushing deformation of the frame 86 is disturbed by the deformation of those panels. There is no. .

Further, in the first and second embodiments, the joint members 10 and 20 are formed in the frame 86 and the bumpers are connected to the joint members 10 and 20, however, the present invention is not limited to this. For example, a bracket formed in a closed cross-section like the frame 86 may be connected to the front end of the frame 86 of the first embodiment, and a bump-shaped member may be provided in the bracket to connect the bumper. Good. In this case, the first bead 92 may be formed on the bracket, and the first bead 92 and the second bead 90 may be formed on the bracket.

[0088]

As described above, according to the structure for fixing a bumper to a vehicle frame according to the first aspect of the present invention, the load applied to the bumper at the time of a vehicle collision can be reduced by using the node-like member provided in the closed section of the frame. The structure can be sufficiently transmitted to the frame side with a simple structure through the first bead, and the effect of the structure on the frame side can be sufficiently extracted to reduce the maximum crushing load at the initial stage of the load input.

According to the second aspect of the present invention, the load transmitted from the bumper side to the node-like member can be reliably and directly applied to the first member.
It can be added to the bead, and the effect of reducing the initial load can be further enhanced, so that it can be exerted as much as desired.

According to the fourth aspect of the present invention, the load from the bumper side can be reliably applied to the first bead, so that the function of reducing the initial load can be exerted to the maximum, and the bumper with respect to the node-like member can be used. The connecting structure can be designed relatively freely.

According to the fifth aspect of the present invention, all corners of the frame are easily crushed, and the initial maximum crushing strength can be more effectively reduced.

According to the sixth aspect of the present invention, it is possible to reliably prevent the breakage or excess thickness at each corner of the frame from hindering the crush deformation guide by the first bead.

According to the seventh aspect of the present invention, at the time of a vehicle collision, the second bead can guide the frame so as to be crushed and deformed in a targeted crushing mode. High crush resistance can be stably maintained.

According to the eighth aspect of the present invention, it is possible to increase the easiness of collapsing of the concave and convex beads due to the load in the frame extending direction, thereby achieving a greater reduction in the initial maximum proof stress. it can.

According to the ninth aspect of the present invention, it is possible to smoothly and reliably start the crushing deformation in accordance with the second bead in the first bead side end region of the second bead.

According to the tenth aspect of the present invention, the crushing deformation guide by the second bead can be more reliably performed.

According to the eleventh aspect of the present invention, it is possible to prevent tension and compression in the cross section at each position in the frame extending direction when the frame is crushed and deformed. It is possible to prevent the deformation of the second bead from being hindered.

According to the twelfth and thirteenth aspects of the invention, it is possible to prevent the movement of the corners caused by the crush deformation of the frame from hindering the crush deformation guide by the second bead.

According to the fourteenth aspect, the seventh aspect is provided.
As in the case of the described invention, a large average crushing strength can be ensured.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a structure for fixing a bumper to a frame according to Embodiment 1 of the present invention.

FIG. 2 is a perspective view showing a frame structure.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2;

FIG. 5 is a perspective view showing a deformed state of the frame shown in FIG. 2;

FIG. 6 is a sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is a perspective view showing a deformed state of the frame shown in FIG. 2;

FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 7;

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a sectional view taken along line XX of FIG. 7;

FIG. 11 is a diagram corresponding to FIG. 1 showing a configuration of a modification of the first embodiment.

FIG. 12 is a diagram corresponding to FIG. 1 showing a configuration of a modification example different from FIG. 11 of the first embodiment.

FIG. 13 is an explanatory diagram showing the influence of the width of the first bead on the initial maximum proof stress.

FIG. 14 is a sectional view showing a shape of a first bead.

FIG. 15 is an explanatory diagram showing the magnitude of a load at each crush amount.

FIG. 16 is a front view showing a structure for fixing a bumper to a frame.

FIG. 16 is a view showing the upper flat portion of the frame omitted.
FIG.

FIG. 18 is a side view of FIG.

FIG. 19 is a diagram corresponding to FIG. 1 according to the second embodiment of the present invention.

FIG. 20 is a diagram corresponding to FIG. 17 according to another embodiment of the present invention.

FIG. 21 is a diagram corresponding to FIG. 2, showing a configuration of a frame according to another embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 10 first node member 20 second node member 30 reinforcement (bumper) 31 weld bolt 33 nut 54, 56, 58, 60, 62, 64, 66, 68
Plane portions 70, 72, 74, 76, 78, 80, 82, 84
Corner part 86 Front frame (frame) 90 Second bead 90a Concave part 90b Convex part 92 First bead 92a Concave ridge 92b Convex ridge 96, 98 Reinforcement plate

Claims (14)

[Claims] 1. A vehicle according to claim 1, further comprising a corner portion between the plane portions adjacent to each other in the circumferential direction. It is composed of a concave ridge formed on one of the plane portions and a convex ridge formed on the other side so as to be continuous with the concave ridge via a corner portion,
A first bead for reducing the initial maximum proof stress of the frame is provided, and a bumper fixing structure in which a bumper is connected and fixed to a frame on the outer end side of the vehicle with respect to the first bead; A vehicle frame characterized in that a knot-like member joined to the inner peripheral surface of the frame and partitioning the inside of the frame is provided in the end frame closed cross section, and the bumper is connected and fixed to the knot-like member. Bumper fixing structure. 2. The bumper fixing structure according to claim 1, wherein the knot-like member is provided near the first bead. 3. The bump according to claim 1, wherein a bolt extending toward the bumper is fixed to the knot-shaped member. The bumper includes a nut and a nut screwed to the bolt from the bumper. A bumper fixing structure to a vehicle frame, wherein the bumper fixing structure is fixed to the node-like member. 4. The frame according to claim 1, wherein two knots are provided side by side in the frame extending direction, and one of the two knots is arranged close to the first bead, and the other knot is provided. A bolt extending toward the bumper is fixed to the shaped member, and the bumper is fixed to the node-shaped member by the bolt and a nut screwed to the bolt from the bumper side. Structure to fix the bumper to the vehicle frame. 5. The bumper for a vehicle frame according to claim 1, wherein the first bead is formed over substantially the entire circumference including all corners of the frame. Fixed structure. 6. The method according to claim 1, wherein the first bead has a depth of one concave streak and a height of the other convex streak of two adjacent flat portions forming each corner. The bumper fixing structure to the vehicle frame, wherein is set substantially the same. 7. The substantially crushed pitch overall length at a substantially crushed pitch along a frame extending direction in a frame plane portion on the inner side of the vehicle body than the first bead. The bumper fixing structure to the vehicle frame, wherein the second bead for improving the average yield strength in which the concave portion and the convex portion are alternately formed is formed so as not to cover the corners on both sides. 8. The bumper fixing structure according to claim 7, wherein the width of the first bead in the frame extending direction is set shorter than the crushing pitch of the second bead. 9. The intermediate bead according to claim 7, wherein the second bead is continuous with the first bead in the frame extending direction or has a length that is an integral multiple of the crushing pitch with respect to the first bead. A bumper fixing structure to a vehicle frame, wherein the bumper is fixed to the vehicle frame. 10. The bumper fixing structure according to claim 7, wherein the second bead is formed on two opposing flat portions of the frame. 11. The vehicle frame according to claim 10, wherein the two second beads facing each other are formed such that when one is a concave portion in the frame extending direction, the other is a convex portion. Bumper fixing structure. 12. The second bead according to any one of claims 7 to 11, wherein the second bead is moved at least from a corner on both sides of a plane portion on which the second bead is formed when the frame is collapsed. A bumper fixing structure for a vehicle frame, wherein the bumper fixing structure is formed in a remaining area after subtracting the above. 13. The second bead according to claim 12, wherein the second bead is formed in a remaining area obtained by subtracting a length of about 潰 of a crushing pitch from a corner on both sides of a plane portion on which the second bead is formed. A bumper fixing structure to a vehicle frame, characterized in that the bumper is fixed to the vehicle frame. 14. The frame according to any one of claims 1 to 6, wherein in a frame closed cross section on the vehicle body inner side of the first bead, at least one flat portion of the frame is opposed to the frame extending direction. A reinforcing plate having an extending reinforcing flat portion is provided, and the reinforcing flat portion has an average yield strength in which a concave portion and a convex portion are alternately repeated at a substantially crushing pitch along the frame extending direction at the substantially crushing pitch. A second bead for forming a bumper.