JPH09250522A - Attachment structure for vehicle member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the rigidity to be declined, substantially in the same way as a hollow material, by restraining the deformation of the attachment part of the buffering member for vehicle composed of aluminum alloy extrusion material with solid shaped cross-section. SOLUTION: A bumper 5 composed of an aluminum alloy extrusion material with the groove-shaped cross-section is attached to a stay 6 with a flange part 6b. When the opening of the bumper 5 is turned to the stay 6 side to be attached, the cross-section of the bumper 5 is made to be a closed cross-section in the attachment part by the front part 6a of the stay 6, and the deformation in the spreading direction is prevented by the flange part 6a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a vehicle member and a mounting member, and more particularly to a bumper member, a door beam,
It is suitable for a vehicle dampening member such as a door damageer and a mounting structure for a mounting member.

[0002]

2. Description of the Related Art In recent years, aluminum extruded materials have come to be used as a cushioning member for vehicles such as bumper members, door beams, door damageers and the like, and a reinforcing member for the purpose of weight reduction. Hollow aluminum extruded material is applied. However, the die structure of aluminum extruded material with a closed cross section becomes complicated,
Since there is a welded part, the extrusion speed is slow and productivity is poor, and because the extrusion resistance is large, it is difficult to manufacture with a high strength alloy, and the range of alloy selection is limited. Came to be applied in the department. For example, JP-A-5-311309 describes an example in which a door beam of an automobile is formed of a solid extruded material. Further, FIG. 7 is an example of a rear bumper of a truck as seen from an oblique rear side, and a rear bumper 1 made of an aluminum extruded material is attached to a stay 2 by welding (arrow P indicates a load direction).

Further, in a rear bumper using an iron shape member, not an aluminum extruded material, as shown in FIG. 8, the mounting is done by welding the upper end to the stay with the opening side of the rear bumper 1 facing rearward. General, and also FIG.
As shown in (a), there is also an example in which the opening of the rear bumper 1 having an open cross section, which is manufactured by bending an iron plate, is directed rearward, and the flange 1a thereof is welded to the stay 2.

[0004]

By the way, a shock absorbing member for a vehicle, for example, a door beam of a passenger car is required to have load absorbing performance at the time of a collision as its role. For example, FMVSS
(US Federal Safety Standards) Finally, when a load is applied from the side of the actual vehicle, a certain reference value is set for the bending load value for that load and the energy absorption amount expressed by the area of the load-deformation relationship. However, at a laboratory level, they are generally assumed to collide with a vehicle, and as shown in FIG. 1A, both ends of the member A are supported and the central portion thereof is pressed by the load jig B. 3 It is evaluated by the bending performance of point bending.

Bending moment M in the above three-point bending test
Is distributed as shown in FIG. 1B, and no bending moment is generated in the supporting portion. However, when mounted on an actual vehicle, the member is fixed to the mounting member (corresponding to the supporting portion of the three-point bending test) unlike the simple three-point bending, so that the bending moment M acts on the mounting portion and the axial force is also applied. Deformation is caused by the action of N (vertical load applied to the mounting portion). Therefore, the generally applied test method as shown in FIG. 1 does not take into consideration the deformation behavior of the mounting portion which should occur due to the bending moment M and the axial force N.

As a result of various studies, the inventors of the present invention have found that in vehicle cushioning members such as door beams, bumpers, door damageers, etc., not only the loaded central cross section but also the behavior of the mounting portion influences the bending performance. I found it. For example, in the case of a door beam, the strength / rigidity of the entire door / body contributes to the load absorption performance in the evaluation based on actual regulations, but the beam itself is relatively in the initial stage of side collision (for a rigid body pushing requirement of 18 inches). It was found that the rigidity of the mounting part has a greater effect on the initial rigidity of the beam than the load part in the central part of the beam. here,
The initial rigidity is the gradient of the load (P) -displacement (X) curve at the time of bending, and generally, the shape of the member at the load point (in the central portion of the member in FIG. 1) and the Young's modulus of the material. However, in a test in which both ends are fixed, such as a door beam, the rigidity of the mounting portion affects the initial rigidity. That is, when the rigidity of the mounting portion is small, the gradient of the load (P) -displacement (X) curve when bent is small, and the amount of collision energy absorption up to a predetermined displacement (X ₀ ) is small. Note that in FMVSS, X _{0 for} the door beam
= 6 inches, the amount of energy absorption within a predetermined displacement of 12 inches is determined. Regarding the rear bumper of the truck, there is a load condition P1 applied to the free end and a load condition P2 applied to the mounting part shown in FIG. 2 in the bending evaluation test based on the JASO standard. The rigidity of is greatly affected.

As described above, in a vehicle cushioning member such as a door beam or a bumper, the behavior of the mounting portion greatly affects the bending performance, but these members formed of a solid material having an open cross section have a closed cross section. Compared to a member made of hollow material, the mounting part that receives a reaction force as a supporting point is easily deformed when it is bent, and when mounted on an actual vehicle, it is restrained by the mounting part rather than simple simple three-point bending. As a result, a bending moment is generated in the mounting part and it is easy to deform,
In either case, the rigidity of the mounting portion is reduced.

The present invention has been made in view of the above problems when a profile having an open cross section is applied to a vehicle member, particularly a vehicle cushioning member or a reinforcing member. An object of the present invention is to provide a mounting structure that suppresses deformation of the mounting portion of the vehicle member and prevents deterioration in rigidity when the mounted vehicle member is fixed to the mounting member.

[0009]

DISCLOSURE OF THE INVENTION The present invention is a mounting structure for a vehicle member and a mounting member, each of which is formed of a profile having an open cross section, and the mounting member has a closed cross section of the mounting portion of the vehicle member. In addition, the vehicle member mounting structure is characterized in that the closed cross section is restrained. The vehicle member is
For example, it is preferable to use a solid aluminum alloy extruded material. Note that constraining the closed cross section means
As described in the following embodiments, it means that the opening of the mounting member cross section of the vehicle member is fixed to the mounting member by mechanical means, welding, or the like to suppress deformation of the closed cross section. INDUSTRIAL APPLICABILITY The present invention can be suitably used as a mounting structure for vehicle members, particularly for mounting a rear bumper of a truck, an impact beam of a passenger car or a truck, and a door damageer.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the mounting structure of the present invention, the direction of the opening of the vehicle member is parallel to the assumed load direction,
In addition, it is desirable that both members are arranged in such a manner that the load acts in the direction in which the opening is pressed against the mounting member. This is because if the direction of the opening and the load direction are deviated from the parallel direction, a shear component is generated in the opening (the part fixed to the mounting member) due to the load, and even if the direction is parallel, the direction of the load is opposite. And the load acts in the direction of separating the opening from the mounting member.

Hereinafter, the present invention will be described more specifically with reference to FIGS. FIG. 3 shows a mounting structure of the bumper 5 and the stay 6 made of a material having an open cross section (groove shape). The opening side of the bumper 5 faces the stay 6 and the front portion 6 of the stay 6 is shown.
The bumper 5 is closed by a, and the bumper 5 has a closed cross section at the mounting portion. Further, the flange portion 6b of the stay 6
Wraps the outside of the opening of the bumper 5, and the rivet 7 fixes both. In this way, since the cross section of the bumper 5 is a closed cross section at the mounting portion and the opening is fixed to the flange portion 6b, the bumper 5 is not deformed in the same manner as when a hollow material is used at the mounting portion. Suppressed. In this example, if the assumed load direction is the direction indicated by the arrow P in FIG. 3, the load P acts in the direction in which the opening is pressed against the front portion 6a of the stay 6, and no shearing force is generated. The mounting structure of FIG. 3 is an image of a case where the bumper 5 made of an aluminum extruded material having a solid cross section is mounted on the iron stay 6, but when the bumper 5 is iron, welding may be used instead of the rivet.

FIG. 4 shows a mounting structure of a door beam 8 made of an aluminum extruded material having an open cross section (a solid shape consisting of two webs and upper and lower flanges) and a bracket 9 made of the same solid aluminum extruded material. The opening side flange 8a of the door beam 8 is fitted into the groove of the bracket 9 and completely enclosed, and the opening side of the door beam 8 is closed at the mounting portion to form a closed cross section. Further, the opening of the door beam 8 is fitted into the groove of the bracket 9 so that the bracket 9
Since the door beam 8 is fixed to, the deformation of the door beam 8 is suppressed in substantially the same manner as when a hollow material is used in the mounting portion. In this example, if the assumed load direction is the direction indicated by arrow P in FIG. 4, the load P acts in the direction in which the opening is pressed against the bracket 9, and no shearing force is generated.

FIGS. 5A to 5D show another example of the mounting structure of the bumper 5 and the stay 6 which are made of a material having an open cross section (groove shape). The opening side of the bumper 5 defines the stay 6. It is closed by the orientation stay 6, and the cross section of the bumper 5 is a closed cross section at the mounting portion. Further, since the bumper 5 is fixed to the stay 6 by welding at the mounting portion,
The deformation of the bumper 5 is suppressed in substantially the same manner as when the hollow member is used in the mounting portion. In the case of FIG. 5A, if the assumed load direction is the direction indicated by arrow P, the load P
Acts in the direction of pressing the opening against the stay 6, and no shearing force is generated. However, in the case of FIG. 5C, since the opening portion acts in the direction of separating the stay 6 from the stay 6, the arrangement of FIG. 5A is preferable for the load P.

The shape member having an open cross section which constitutes the vehicle member of the present invention is not limited to the above example, but various shapes as shown in FIG. 6 can be used. However, when used as a cushioning member for a vehicle such as a bumper or a door beam, two or more constituent parts (in the case of FIG. 3, a flange portion 5a, which are parallel to the cross section having high rigidity and strength against bending, that is, the load direction). A cross section having a web portion 8b in the case of FIG. 4 and a portion indicated by an arrow in the case of FIG. 6) is preferable.

For comparison, assuming that the rear bumper 1 of FIG. 9A is loaded with the loads P1 and P2 of FIG. 2, the load P is applied from the direction in which the cross section is opened. At that time, the cross section is deformed in the opening direction as shown in FIG. 9B, and the rigidity is likely to be reduced. Further, when the cross section opens, the load point moves outward, and accordingly, the foot 1 of the moment increases with respect to the stay 2, and the stay 2 is also deformed. Attempting to prevent the deformation will increase the weight of the stay.

[0016]

According to the mounting structure for a vehicle member according to the present invention, the mounting portion of the vehicle member constituted by the shape member having an open cross section has a closed cross section, so that deformation of the mounting portion is suppressed and rigidity is increased. Can be prevented. In addition, when the vehicle member is made of a solid aluminum alloy extruded material, the advantages of solid compared to the hollow are that the die structure is simple and inexpensive, and the extrusion productivity is excellent because it does not have a welded part. It is possible to increase the rigidity of the mounting portion while maintaining the advantages that alloys that cannot be manufactured by can be applied and the range of alloy selection can be expanded.

[Brief description of the drawings]

FIG. 1 is a schematic diagram (a) of a general three-point bending test with simple support for evaluating a vehicle member subjected to bending in a laboratory and a distribution diagram (b) of bending moments at that time.

FIG. 2 is a schematic diagram showing a bending evaluation test of a truck rear bumper based on JASO.

FIG. 3 is a perspective view showing an example of a mounting structure of the present invention.

FIG. 4 is a sectional view (a) of a mounting portion showing another example of the mounting structure of the present invention and a perspective view (b) illustrating a mounting method thereof.

5A and 5B are perspective views (a) and (c) of a mounting portion and sectional views (b) and (d) of the mounting portion showing still another example of the mounting structure of the present invention.

FIG. 6 is an example (cross-sectional view) of a vehicle member having an open cross section used in the present invention.

FIG. 7 is a perspective view showing a conventional truck rear bumper mounting structure.

FIG. 8 is a perspective view showing another conventional mounting structure for a truck rear bumper.

FIG. 9 is a side view showing another mounting structure of the conventional truck rear bumper (a) and a view showing a deformed state under load (b).
It is.

[Explanation of symbols]

 5 Bumper 6 Stay 7 Rivet 8 Door beam 9 Bracket

Claims (3)

[Claims] 1. A mounting structure for a vehicle member and a mounting member, wherein the mounting member has a closed cross section, and the mounting member has a closed cross section. A vehicle member mounting structure characterized by being restrained. 2. The members of the vehicle member are arranged such that the direction of the opening of the vehicle member is parallel to the load direction, and the members are arranged so that the load acts in the direction of pressing the opening against the mounting member. The mounting structure for a vehicle member described in 1. 3. The mounting structure for a vehicle member according to claim 1, wherein the vehicle member is made of a solid aluminum alloy extruded material.