JPH08216916A - Shock absorbing frame made of extrusion-molded aluminum material excellent in shock absorbing property - Google Patents

Abstract

PURPOSE: To provide a shock absorbing frame made of extrusion-molded aluminum material excellent in shock energy absorbing property and equipped with a fin for mounting equipment or member. CONSTITUTION: This has a cross section in the shape of a polygon such as a rectangle or the like whose interior is caved, and at the corner between each side 7 and 8 is a fin for mounting equipment made. The inner cavity demarcated by the rectangular cross section may be one being divided into plural ones by bulkheads. The fin 6 curves by rotational moment, so it is never an obstacle to the deformation of the sides 7 and 8. Therefore, shock energy is efficiently absorbed as the buckling deformation of a structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as a frame material for front side frames, rear side frames, etc. of various vehicles, and efficiently absorbs impacts at the time of a collision by plastic deformation in the axial direction, so that drivers and passengers The present invention relates to a shock absorbing frame made of an aluminum extruded profile for protecting a vehicle.

[0002]

2. Description of the Related Art Various types of shock absorbing members are incorporated in automobiles to absorb the impact when they collide with or come into contact with other automobiles or objects. The shock absorption mode includes a method of incorporating a liquid damper or the like into a structural material such as a bumper, a method of using the structural material itself as an energy absorber, and a method of interposing a spring between the structural body and the vehicle body. Above all, the method of absorbing the collision energy by plastic deformation of the structural material can absorb a large amount of energy, and is therefore expected to be developed as a shock absorbing member. For example, Japanese Laid-Open Patent Publication No. 6-247337 discloses, as this type of shock absorbing member, a fragile portion is provided by compression processing or overhanging processing so as to be a starting point of crushing due to energy at the time of collision.

The shock absorbing frame is used as the front side frame 3 or the rear side frame 3 ', as shown in the schematic view of the perimeter frame in FIG. 1, for example. The front side frame 3 or the rear side frame 3'is provided with deformation starting portions 4 and 4'which are the starting points of buckling deformation, and the connecting members 2 and 2'are provided with the impact dispersion portions 5 and 5.
5 'is provided. When a shock is applied to the bumper 1 from the front due to a vehicle collision or the like, or a shock is applied to the rear bumper 1'from the rear, the shock absorbing frames 3 and 3'are continuous as shown schematically in FIG. It buckles and deforms and absorbs the applied shock. As a result, the impact transmitted to the intermediate frame M is reduced, and the occupant is protected.

[0004]

In a structural material that absorbs impact energy by plastic deformation, the applied impact causes the structural material to buckle and deform. When this buckling continues,
Since large impact energy is dispersed and absorbed by each buckling deformation, the impact on the occupant is reduced. When the impact energy is absorbed by plastic deformation, the absorption of the impact energy proceeds once the plastic deformation is started, but a large amount of energy is required to start the plastic deformation.
Therefore, the impact applied until the plastic deformation starts is transmitted to the occupant. Therefore, in order to reduce the impact until the plastic deformation is started, various improvements have been made to the shape of the structural material that is easily plastically deformed. However, JP-A-6-24
As described in Japanese Patent No. 7337, even if a fragile portion serving as a starting point of plastic deformation is provided, the initial load is still at a high level and the impact on the occupant is large.

The structural material includes various parts, hydraulic piping,
In many cases, fins are formed to attach devices and members such as a bracket for fixing electric wiring. This kind of fin restrains the plastic deformation of the structural material and tends to prevent the buckling deformation effective for absorbing the impact energy. Therefore, even if the shape of the structural material itself is improved, the improvement effect may be offset by the fins for attaching the device or the member. The present invention has been devised to solve such a problem, and by providing fins at the corners of the structural material, regular and continuous buckling deformation is generated, and impact energy is efficiently generated. An object is to provide a structural material that absorbs.

[0006]

In order to achieve the object, an aluminum extruded profile shock absorbing frame of the present invention has a polygonal cross section with a hollow inside, and has a corner portion between each side. It is characterized in that a fin for attaching a device or a member is formed. A typical polygonal cross section is a rectangular cross section, and a partition wall that divides the internal space into a plurality of sections can be formed. Further, fins for attaching a device or a member may be formed on the extension line of the partition wall.

[0007]

[Operation] In the shock absorbing frame, the adjacent sides are deformed inward and outward, and the inward and outward deformations are alternately generated in the axial direction of the frame, and are sequentially deformed so that they are folded. Then, the regular buckling deformation becomes continuous, and the impact absorption capacity increases. The present inventors conducted various investigations and studies on a structure suitable for making such regular buckling deformation continuous. Further, in this structure, the influence of fins provided for fixing various devices, hydraulic pipes, brackets for fixing electric wiring, etc., on the buckling deformation was investigated. As a result, it has been found that when the fins are provided at the corners of the structural material, the fins are prevented from acting as resistance against the plastic deformation of the structural material, and the regular buckling deformation is smoothly continuous. For example, as shown in FIG. 3, in the structural material having the fins 6 attached to the corners, when the side 7 is deformed inward and the side 8 is deformed outward (a), the rotational moment M ₁ acts on the corner. . Fin 6
Is bent by the rotation moment and does not serve as a resistance that prevents the regular deformation of the sides 7, 8. Side 7 is outside,
Even when the side portion 8 is deformed inwardly (b), the fin 6 is similarly bent by the rotation moment M ₂ , and the side portions 7 and 8 are formed.
Deformation, that is, buckling deformation proceeds smoothly. Moreover,
The energy required for the deformation of the fin 6 itself contributes to the absorption of impact energy.

On the other hand, when the fin 6 is provided in the middle of the side portion 7, no rotational moment acts on the fin 6. Therefore, when the side portion 7 is going to be deformed in either the outer side (c) or the inner side (d), the fin 6 acts as a resistance to prevent the side portion 7 from being deformed. as a result,
Regular buckling deformation does not occur and the absorption efficiency of applied impact energy decreases. As is clear from this contrast,
By specifying the formation location of the fins 6 at the corners, the buckling deformation of the structural material in response to the applied impact is not restrained by the fins 6, so it is equipped with attachment parts for various devices and members, and has excellent impact absorption performance. A structural material can be obtained. The fins attached to the structural material consider the equipment and members to be installed,
It can be provided at a plurality of corners as shown in FIGS. 4 (a) and 4 (b). When the fins 6 and 6 are attached to the member having the partition wall 9 in the hollow portion as shown in FIG. 4C, the fins 6 and 6 can be attached on the extension line of the partition wall 9. This is because the vertical side of FIG.
This is because it has been confirmed that it is divided into a and 7b, and that each deforms in the opposite direction. In this case, the respective fins 6, 6 are bent by the addition of bending moments M ₃ , M ₃ , and the fins 6, 6 do not prevent regular deformation.

[0009]

【Example】

Example 1: Using an aluminum alloy A6061-T _4, 5 to the extrusion fins 6 are provided to the corner portions as shown shape members (a) and extruded shaped fins 6 are provided in the middle of the side portions Material (b) was produced. The extruded profile (a) has a side portion a = 80 mm, a side portion b = 53 mm, and a wall thickness t ₁ = 2.3 m.
m, the wall thickness t ₂ = 2.4 mm, the wall thickness t ₃ = 2.31 mm, and the length c = 20 mm and the wall thickness t ₄ = 2.
35 mm fins 6 were provided at the corners. Extruded profile (b)
Then, the fins 6 of the same size are provided in the middle portion of the sides of the rectangular cross section of the same size. In addition, any extruded shape member has a depth of 5 mm and a width of 80 mm at a position 30 mm from the end in the longitudinal direction.
The recessed portion was molded by pressing to form the deformation starting portion 10.

A test piece having a length of 500 mm was cut out from each extruded shape member, and a compressive load in the axial direction was applied by a hammer test in which a weight of 4.8 KN was dropped to investigate the relationship between the load and the displacement amount. The survey results are shown in FIG. In the test piece with the fins 6 provided at the corners (FIG. 5a), the relationship between the displacement amount and the load changes in a periodic cycle as seen in the curve (a). The initial load also showed a low value of about 60 KN, which was about 1.2 times the periodic peak value. On the other hand, in the test piece (FIG. 5b) in which the fins 6 were provided in the middle of the side portion, the initial load showed a high value of 90 KN as shown in the curve (b), and the entire buckling occurred. Also, the amount of energy absorbed by buckling deformation was small. As is clear from this comparison, the extruded shape member with the fins 6 attached to the corners (see FIG.
In a), the applied load is smoothly absorbed as buckling deformation, and it is understood that impact energy is smoothly absorbed without giving a large impact at the initial stage of deformation. As shown in FIG. 7, the extruded shape member after buckling deformation has a deformation starting portion 10
The recesses had a regular shape with the inside protruding and the surface not forming the recesses protruding outward.

Example 2 Extrusion in which the same aluminum alloy A6061-T ₄ as in Example 1 was used, a partition 9 was provided inside the hollow as shown in FIG. 8, and fins 6 were provided on the extension line of the partition 9. A profile was produced. The extruded profile has sides a = 80 mm, sides b ₁ = 53 mm, b ₂ = 43 mm,
It has a rectangular cross section with wall thickness t ₁ = 2.22 mm, wall thickness t ₂ = 2.35 mm, wall thickness t ₃ = 2.26 mm, wall thickness t ₄ = 2.31 mm, wall thickness t ₅ = 2.32 mm, Length c = 20m
A fin 6 having a thickness m and a wall thickness t ₆ = 2.25 mm was provided on an extension line of the partition wall 9. Further, the side portions b _2, b _3, the longitudinal from direction end portions of 30mm position of b _4, a concave side portions b _2, b _3, b ₄ width direction over the entire length depth 5mm of molded by press working, The deformation starting portion 10 was formed. A test piece having a length of 500 mm was cut out from this extruded shape member, an axial compressive load was applied using an Amsler universal tester, and the relationship between the load and the displacement amount was investigated. The displacement-load relationship changed in a periodic cycle, as shown in FIG. 9 showing the investigation results. The initial load is 1.17 of the periodic peak value.
It showed a low value of about 89 KN, which is about double the value. From this,
It was confirmed that the impact energy can be smoothly absorbed by regular buckling deformation.

[0012]

As described above, the shock absorbing frame of the present invention has a polygonal cross section, and fins for attaching a device or a member are formed at the corners. When the extruded profile is incorporated into a vehicle as a structure for shock absorption, the fins are located at the corners, so the fins do not act as a resistor when the structure under impact is buckled and deformed regularly. Moreover, the buckling deformation progresses continuously. As a result, the impact energy is efficiently absorbed as the buckling deformation of the structure, and the occupant is protected.

[Brief description of drawings]

FIG. 1 is a schematic perspective view in which a shock absorbing frame in which a side frame having a shock absorbing ability is attached to a front side frame or a rear side frame is used as a perimeter frame.

[Fig. 2] Shock absorbing frame buckled and deformed by shock

FIG. 3 is a diagram for explaining the influence of the fin installation location on the deformation of the shock absorbing frame, where the fins are attached to the corners (a, b) and the fins are attached to the middle part of the sides (c,
d)

FIG. 4 shows another example of a shock absorbing frame, in which a plurality of fins are attached to corners (a, b) and fins are provided on an extension line of a partition wall (c).

FIG. 5 is a shock absorbing frame (a) having fins at corners and a shock absorbing frame (b) having fins at an intermediate side portion used in Example 1;

FIG. 6 is a graph showing the relationship between the displacement amount and the load of the shock absorbing frame used in Example 1.

FIG. 7 shows the shape of the shock absorbing frame with fins at the corners after buckling deformation.

FIG. 8 is a shock absorbing frame in which a fin is provided on an extension line of the partition wall used in Example 2

FIG. 9 is a graph showing the relationship between the displacement amount and the load of the shock absorbing frame used in Example 2.

[Explanation of symbols]

1: Bumper 1 ': Rear damper 2, 2': Connecting member 3: Front side frame 3 ': Rear side frame 4, 4': Deformation start part 5,
5 ': Impact dispersion part 6: Fins 7, 8: Side part
9: partition 10: deformation starting portion M _1, M _2: rotation moment M _3: bending moment t ₁ ~t _6: thickness

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiichi Sugiyama 3-13-12 Mita, Minato-ku, Tokyo Within Japan Light Metals Co., Ltd.

Claims (4)

[Claims] 1. A polygonal cross section having a hollow interior,
A shock-absorbing frame made of extruded aluminum with excellent shock-absorbing characteristics, with fins for mounting equipment or members formed at the corners between each side. 2. An impact made of an extruded aluminum profile having excellent shock absorption characteristics, which has a rectangular cross section with a hollow inside, and fins for equipment or member attachment are formed at the corners between each side. Absorption frame. 3. A shock absorbing member made of an extruded aluminum profile according to claim 2, wherein one or more partition walls are formed to extend from the inner side surface of the side to the inner side surface of the opposite side and divide the inner cavity into a plurality of partitions. flame. 4. A shock-absorbing frame made of an extruded aluminum profile having excellent shock-absorbing characteristics, in which fins for mounting a device or a member are formed on an extension line of the partition wall according to claim 3.