WO2013164931A1

WO2013164931A1 - Impact absorption mechanism

Info

Publication number: WO2013164931A1
Application number: PCT/JP2013/058070
Authority: WO
Inventors: 修久奥田
Original assignee: トヨタ車体株式会社
Priority date: 2012-05-01
Filing date: 2013-03-21
Publication date: 2013-11-07
Also published as: JP2013231484A

Abstract

An impact absorption mechanism mounted to a vehicle is provided with a column-shaped impact absorption section (20), the impact absorption section (20) having a tube-shaped member (23) and wood (12) which is housed within the tube-shaped member (23), the direction of the fibers of the wood (12) being aligned with the axial direction. The impact absorption section (20) is disposed between a load receiving member (3), which receives an impact load, and a framework member (5) of the vehicle. When an impact load is applied to the impact absorption section (20) from the load receiving member (3), the impact absorption section (20) can absorb the impact load because at least the wood (12) is crushed in the axial direction. The impact absorption mechanism is in a state in which one end of the impact absorption section (20) in the axial direction is joined to the framework member (5) or the load receiving member (3) by a joining means, and in which the other end is joined to neither of the framework member and the load receiving member (3) when an impact load is applied.

Description

Shock absorption mechanism

The present invention relates to an impact absorbing mechanism configured to receive an impact load at the time of a vehicle collision or the like and absorb the impact load.

Japanese Patent Application Laid-Open No. 2001-182769 describes a technique of an impact absorbing member relating to this technical field. As shown in FIG. 11, the automobile impact absorbing member 100 described in this document includes a rectangular hollow metal hollow member 102 and a piece of wood 105 filled in the hollow member 102. The bumper reinforcement 108 is held at a predetermined position with respect to the side member 107 of the vehicle frame by the impact absorbing member 100.

As shown in FIG. 12, one end of the shock absorbing member 100 is coupled to the front ends of the left and right side members 107 of the automobile via a support member 106. The other end of the shock absorbing member 100 is also coupled to the back surface of a bumper reinforcement 108 of a front bumper (not shown) via another support member 106. As described above, since both ends in the axial direction of the shock absorbing member 100 are fixed, the shock absorbing member 100 is difficult to fall down when receiving the shock load F, and the shock load F is received in the axial direction consistently. Can do.

However, since both ends of the shock absorbing member 100 are constrained by the support material 106, the shock absorbing member 100 is hardly crushed to both ends as shown in FIG. That is, the impact load F can be absorbed only by the portions excluding both ends of the impact absorbing member 100. Thus, since the range which is crushed within the limited length of the shock absorbing member 100 is reduced, it is difficult to increase the shock absorption amount.

From one aspect of the present invention, an impact absorbing mechanism installed in a vehicle can be obtained. This shock absorbing mechanism includes a columnar shock absorbing portion having a tubular member and wood housed in the tubular member and in which the fiber direction of the wood is directed in the axial direction. The impact absorbing portion is disposed between a load receiving member that receives an impact load and a skeleton member of the vehicle, and when the impact load is applied from the load receiving member, at least the wood is crushed in the axial direction so that the impact is reduced. The load can be absorbed. One end in the axial direction of the impact absorbing portion is coupled to the skeleton member or the load receiving member by a coupling means, and the other end is not coupled to either the skeleton member or the load receiving member when an impact load is applied It is.

When an impact load is applied to the impact absorbing portion, only one end of the impact absorbing portion is coupled to the vehicle skeleton member or load receiving member. Thus, since only one end of the shock absorbing portion is in a cantilever state fixed by the coupling means, the other unconstrained other end can be crushed in the same manner as the intermediate portion.

It is a schematic plan view of a vehicle front part provided with the impact absorption mechanism by the embodiment of this invention. It is a perspective view showing the impact-absorbing mechanism by the embodiment of this invention. FIG. 3 is a cross-sectional view taken along the line III-III of the shock absorbing mechanism shown in FIG. It is a longitudinal cross-sectional view showing the impact-absorbing part of the impact-absorbing mechanism by the embodiment of this invention. It is a longitudinal cross-sectional view showing a mode that the cylindrical member and wood of an impact-absorbing part are crushed by an impact load. It is a graph showing the relationship between the impact load added to the impact absorption mechanism by this embodiment, and the amount of crushing. It is a graph showing the relationship between the impact load added to the conventional impact-absorbing member, and the amount of crushing. It is a side view showing the shock absorption mechanism by the embodiment which changed the form of the shock absorption part. It is a side view showing the impact-absorbing mechanism by the embodiment which changed the aspect which couple | bonds an impact-absorbing part. It is a side view showing operation | movement of the impact absorption mechanism shown in FIG. It is a side view showing the shock absorption mechanism by the embodiment which changed the form of the bumper support part. It is a model longitudinal cross-sectional view of the conventional impact-absorbing member. It is a model longitudinal cross-sectional view showing the attachment structure of the conventional impact-absorbing member. It is a model longitudinal cross-sectional view showing a mode that the conventional impact-absorbing member is crushed.

Hereinafter, various embodiments of the present invention will be described with reference to FIGS.

[Outline of shock absorbing mechanism]
The impact absorbing mechanism is a mechanism for absorbing an impact load F received by the bumper reinforcement 3 at the time of a vehicle collision, for example. As one embodiment, as shown in FIG. 1, the shock absorbing mechanism 10 can be disposed between the bumper reinforcement 3 of the front bumper (not shown) and the left and right side members 5 of the lower frame of the vehicle 2. However, in some cases, an impact absorbing mechanism can be provided in the middle of the vehicle frame.

As shown in FIGS. 2 and 3, the impact absorbing mechanism 10 includes a support member 30 that supports the bumper reinforcement 3 at a predetermined position with respect to the side member 5, an impact absorbing portion 20 for absorbing the impact load F, and the like. It has. Here, the front-rear, left-right, and upper-lower directions in the following description are determined with reference to a vehicle having an impact absorbing mechanism as shown in the drawings.

[Support member]
For example, as shown in FIG. 3, the support member 30 may include a receiving portion 32 of the impact absorbing portion 20 and a bumper support portion 35 that supports the bumper reinforcement 3. The receiving portion 32 can be a highly rigid member having a flat receiving surface 32f on the front side, for example. In particular, the receiving portion 32 may be a flat plate member arranged in a vertical direction and having a large wall thickness. The receiving surface 32f may not be flat but may have irregularities. The receiving portion 32 is attached to the tip of the side member 5, and the receiving surface 32 f faces the rear surface 3 b of the bumper reinforcement 3.

The bumper support portion 35 is attached to the receiving surface 32 f of the receiving portion 32. The bumper support portion 35 can be formed, for example, by bending a band plate-like flat plate into a substantially trapezoidal shape as shown in FIG. Specifically, the bumper support portion 35 includes a top portion 35m at the front end, a wall portion 35w extending rearward from the top and bottom of the top portion 35m, and a flange portion 35f extending in the opposite direction from the end of the wall portion 35w.

For example, as shown in FIG. 2, the bumper support portion 35 can be coupled to the upper and lower end edges of the receiving portion 32 by bolts 37 or the like. It is also possible to connect by welding instead of the bolt 37. Alternatively, the receiving portion 32 may be omitted, and the receiving surface 32 f may be provided at the tip of the side member 5, and the bumper support portion 35 may be directly attached to the side member 5.

The rear surface 3b of the bumper reinforcement 3 is attached in a state of being in surface contact with the top portion 35m of the front end of the bumper support portion 35. When the impact load F is received through the bumper reinforcement 3, as shown in FIG. 5, the wall portion 35 w is bent so as to swell up and down, and the top portion 35 m moves together with the bumper reinforcement 3 in the load direction. it can. The bumper support portion 35 is preferably made of a metal such as a steel plate.

[Shock absorber]
As shown in FIG. 4, the impact absorbing portion 20 includes a cylindrical member 23 and a columnar wood 12 accommodated therein, and is arranged so that an impact load F due to a collision or the like can be received in the axial direction of the shape. Is done. The cylindrical member 23 preferably has a regular hexagonal cross section perpendicular to the axis as shown in FIG. The cross section can be formed into a quadrangle, a regular pentagon, or the like. The cylindrical member 23 may be, for example, an extruded product or a pultruded product using an aluminum alloy, or may be a metal other than aluminum.

The cross-sectional shape of the wood 12 is preferably the same as the cross-sectional shape of the cylindrical member 23 (hexagon) as shown in FIG. The length of the wood 12 can be set to be substantially equal to the length of the cylindrical member 23 in the axial direction. The wood 12 is shaped such that the direction of the fibers 12k or the axial direction of the annual rings extends in the length direction (columnar axial direction). For this reason, in a state where the wood 12 is accommodated in the tubular member 23, the direction of the fibers 12 k of the wood 12 substantially coincides with the axial direction of the tubular member 23. For this reason, the wood 12 can receive a large impact load F in the axial direction with high strength. As the type of the wood 12, for example, cedar is preferably used.

[Mounting the shock absorber]
As shown in FIGS. 2 and 3, the shock absorbing portion 20 is coupled to the receiving surface 32 f of the receiving portion 32 in a state surrounded by the bumper supporting portion 35 of the supporting member 30. The shock absorbing part 20 is coupled to the side member 5 through the receiving part 32. More specifically, a plurality of support members 25 having a substantially L-shaped cross section are fixed at equal intervals around one end in the axial direction of the shock absorbing portion 20 as a coupling means to the receiving surface 32f. The support member 25 is coupled to the receiving surface 32f of the receiving portion 32 by welding, bolts, or the like. The axis of the shock absorber 20 may be perpendicular to the receiving surface 32f. As another form, for example, a bolt hole or the like may be formed in the receiving portion 32 and the wood 12 of the shock absorbing portion 20 may be coupled to the receiving portion 32 with a bolt. It is also possible to omit the support member 25 and directly and firmly weld the tubular member 23 to the receiving surface 32f. The tip of the shock absorber 20 is separated from the top 35m of the support member 30, and the shock absorber 20 is held in a cantilevered state. That is, the axial length of the shock absorbing portion 20 is set to be smaller than the distance from the receiving surface 32 f of the support member 30 to the top portion 35 m.

[Operation of shock absorbing mechanism]
Next, the operation of the shock absorbing mechanism 10 will be described with reference to FIGS. When the impact load F receives the bumper reinforcement 3 because the vehicle 2 collides forward, the impact load F is first applied to the bumper support portion 35 of the support member 30 via the bumper reinforcement 3. The bumper support portion 35 is bent by the bumper reinforcement 3 so that the wall portion 35 w swells up and down, and the top portion 35 m comes into contact with the tip of the impact absorbing portion 20. Then, the impact load F is input to the impact absorbing unit 20 in the axial direction via the bumper reinforcement 3. As shown in FIG. 6A, when the impact load F exceeds a certain limit value H, the wood 12 and the cylindrical member 23 start to be crushed in the axial direction. FIG. 5 shows the wood 12 and the cylindrical member 23 crushed in this way. The wood 12 is deformed so as to swell outward together with the cylindrical member 23 by being crushed in the axial direction. In some cases, the wood 12 and the cylindrical member 23 are split at the unconstrained tip and spread radially outward. Thus, the impact load F is absorbed by the wood 12 and the cylindrical member 23, and the impact load transmitted to the side member 5 is reduced.

FIG. 6A is a graph showing a result of measuring a change in an impact load F applied to the impact absorbing portion 20 in the axial direction with respect to a collapse amount (mm) of the impact absorbing portion 20. The length of the cylindrical member 23 in the axial direction was set to about 70 mm, the width dimension (diameter dimension of the hexagonal circumscribed circle) was set to about 28 mm, and the wall thickness dimension was set to about 0.8 mm. The wood 12 has a length of about 70 mm, which is equal to the axial length of the cylindrical member 23, and the width dimension (diameter dimension of a hexagonal circumscribed circle) is a clearance between the outer peripheral surface of the wooden member 12 and the inner peripheral surface of the cylindrical member 23. Is about 28 mm so that is about 0.25 mm. As described above, in the shock absorbing mechanism 10 according to the embodiment of the present invention, the shock absorbing portion 20 is held in a so-called cantilever state, the tip is crushed well, and as shown in FIG. The part 20 was crushed by about 54 mm. FIG. 6B is a graph showing measurement results using the conventional shock absorbing mechanism as shown in FIGS. In contrast to the above results, when both ends of the impact absorbing portion 100 are constrained by some coupling means as in the prior art, as shown in FIG. 6B, the impact absorbing portion having a total length of 70 mm is crushed only by about 40 mm. The part which cannot be crushed remained in the both ends of the part. As described above, it was shown that the shock absorption mechanism 10 according to the embodiment of the present invention has a larger shock absorption amount even when the length is the same as the conventional one.

[Advantageous Effects of Embodiments of the Present Invention]
When the impact load F is applied, only one end in the axial direction of the impact absorbing portion 20 is coupled to the side member 5 of the vehicle 2. That is, since only one end of the shock absorbing portion 20 is fixed by the support member 25 or the like, the other non-fixed end can be crushed in the same manner as the intermediate portion. Therefore, compared to the conventional structure in which both ends of the columnar shock absorber 20 are fixed by some coupling means, the range in which the shock absorber 20 can be crushed can be widened. For this reason, even if it is the impact absorption part 20 of the same length as the past, the amount of shock absorption can be enlarged.

As another embodiment, as shown in FIG. 7, the tip of the impact absorbing portion 20 can be brought into contact with the top portion 35 m of the support member 30 without being coupled. In addition, for example, the tip of the impact absorbing portion 20 can be spot welded (auxiliary coupling) to the top portion 35 m of the support member 30 so that the welding is released when the impact load F is applied. Thereby, when the impact load F is applied, the impact absorbing portion 20 is in a cantilever state, and the tip of the impact absorbing portion 20 can be crushed. Thus, the range in which the impact absorbing portion 20 can be crushed can be widened by intentionally providing a difference in the coupling strength between both ends of the impact absorbing portion 20.

As yet another embodiment, as shown in FIG. 8, it is possible to fix the impact absorbing portion 20 to the bumper reinforcement 3 side and not to the side member 5 side. As shown in FIG. 9, when the impact load F is applied, the rear side of the wood 12 and the cylindrical member 23 is crushed.

Further, the bumper reinforcement 3 is supported at a predetermined position with respect to the side member 5 by the bumper support portion 35 of the support member 30, and the impact absorbing portion 20 does not need to support the bumper reinforcement 3. On the contrary, the bumper support portion 35 hardly absorbs an impact load by being easily bent outward as shown in FIG. Therefore, it is possible to design the support structure of the bumper reinforcement 3 and the shock load absorption performance independently. The shock absorbing performance can be adjusted by changing the cross-sectional area of the shock absorbing portion 20, for example. Further, since only the bumper support portion 35 is responsible for the rigidity required to support the bumper reinforcement 3, by appropriately changing the structure of the support member 30, the support rigidity is consequently improved without affecting the shock absorbing portion 20. be able to.

Further, the bumper support portion 35 of the support member 30 is formed so as to surround the impact absorbing portion 20. Further, the bumper support portion 35 is formed in a trapezoidal shape, and can be bent and deformed in a direction away from the impact absorbing portion 20 as shown in FIG. For this reason, the bumper support part 35 does not prevent the shock absorbing part 20 from being deformed so as to bulge outward. In addition, when the bumper reinforcement 3 can be sufficiently supported, one of the wall portions 35w of the bumper support portion 38 can be omitted as shown in FIG. 10 to simplify the structure.

As another embodiment, the bumper support portion 35 may be curved so as to be convex outward so as to be convexly deformed outward, or a folding line may be provided so as to be convex outward. Alternatively, it can be supported by a support material from the inside so as to be convexly deformed to the outside.

Further, since only one end of the shock absorbing portion 20 is fixed, the shock absorbing portion 20 can be easily attached or replaced.

While embodiments of the present invention have been described with reference to specific embodiments, those skilled in the art will appreciate that many substitutions, improvements, and modifications can be made without departing from the scope of the present invention. Thus, embodiments of the invention are intended to embrace all such alterations, modifications and variations that may fall within the spirit and scope of the appended claims.

Claims

An impact absorbing mechanism installed in a vehicle,
It includes a cylindrical member and a wood housed in the cylindrical member, and includes a columnar impact absorbing portion in which the fiber direction of the wood is directed in the axial direction,
The impact absorbing portion is disposed between the load receiving member that receives the impact load and the skeleton member of the vehicle, and when the impact load is applied from the load receiving member, at least the wood is crushed in the axial direction. Can absorb impact load,
One end in the axial direction of the impact absorbing portion is coupled to the skeleton member or the load receiving member by a coupling means, and the other end is not coupled to either the skeleton member or the load receiving member when an impact load is applied. Is the shock absorption mechanism.
The shock absorbing mechanism according to claim 1,
An impact absorbing mechanism comprising auxiliary coupling means for coupling the other end of the shock absorbing portion in the axial direction to the load receiving member or the skeleton member, and the coupling by the auxiliary coupling means is released when an impact load is applied.
The shock absorbing mechanism according to claim 1 or 2,
An impact absorbing mechanism comprising a support member attached to the skeleton member and supporting the load receiving member.
The shock absorbing mechanism according to claim 3,
The impact absorbing mechanism, wherein the support member is deformed so that when the impact load is applied from the load receiving member, the wood is crushed in the axial direction and the impact absorbing portion is not prevented from expanding outward.
The shock absorbing mechanism according to claim 3 or claim 4,
An impact absorbing mechanism, wherein the support member is formed so as to surround the impact absorbing portion, and a gap is formed between the support member and the impact absorbing portion.
The shock absorbing mechanism according to claim 3 or claim 4,
The support member includes at least one plate-like wall portion passed between the load receiving member and the skeleton member, and a gap is provided between the wall portion and the shock absorbing portion. There is a shock absorbing mechanism.
The shock absorbing mechanism according to claim 5 or 6,
The said support member is an impact-absorbing mechanism formed so that it may deform | transform convex outside when an impact load is added.
The shock absorbing mechanism according to claim 5 or 6,
The impact absorbing mechanism, wherein the support member is supported by a support material from the inside so as to project outwardly when an impact load is applied.