JP2021071176A - Impact absorbing mechanism - Google Patents

Abstract

To provide an impact absorbing mechanism capable of favorably absorbing an impact at a low cost.SOLUTION: An impact absorbing mechanism 5 is fixed to a vehicle to alleviate an impact load applied thereto. The impact absorbing mechanism 5 comprises: an impact absorbing section 7 which is made of wood; a covering section 9 which is made of resin and covers an entire periphery of the impact absorbing section 7; and a connection section 11 which penetrates the impact absorbing section 7 in a direction orthogonal to a load input direction and connects the covering section 9 positioned with the impact absorbing section 7 in between. The covering section 9 has higher rigidity with respect to compression in the load input direction than the impact absorbing section 7 or a material constituting the covering section 9 has higher rigidity with respect to the compression in the load input direction than the wood constituting the impact absorbing section 7. The covering section 9 and the connection section 11 are continuously integrated without a boundary therebetween.SELECTED DRAWING: Figure 3

Description

The present invention relates to a shock absorbing mechanism for reducing a collision load applied to a vehicle.

Patent Document 1 describes a mechanism in which wood is sandwiched between a pair of restraining members as a shock absorbing mechanism at the time of a side collision of a vehicle. This shock absorbing mechanism absorbs the impact by compressing and crushing the wood at the time of a side collision of the vehicle. At this time, by restraining the wood with a restraining member, it is possible to prevent the wood from cracking at the time of a collision. Ensure the impact absorption effect of wood.

JP-A-2019-89484

In Patent Document 1, in order to enable smooth deformation of wood at the time of collision while restraining wood by a restraining member, connecting portions such as bolts that penetrate the wood and connect the restraining members to each other are in a predetermined positional relationship. It is provided. However, in the configuration of Patent Document 1, there is a problem that the parts of the connecting portion and the assembly thereof are costly.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a shock absorbing mechanism or the like capable of suitably performing shock absorption at low cost.

The present invention for achieving the above-mentioned object is a vehicle shock absorbing mechanism for reducing a collision load applied to a vehicle, and covers a shock absorbing portion made of wood and a coating covering the entire outer surface of the shock absorbing portion. The shock absorbing portion is provided with a portion and a connecting portion that penetrates the shock absorbing portion in a direction orthogonal to the load input direction to which the collision load is applied and connects the covering portions at positions sandwiching the shock absorbing portion. The coating is more rigid with respect to compression in the load input direction than the shock absorbing portion, or the material constituting the coating is more rigid with respect to compression than the wood constituting the shock absorbing portion. The shock absorbing mechanism is characterized in that the covering portion and the connecting portion are integrally molded so that the connecting portion is continuous with the covering portion without a boundary.

In the present invention, the entire outer surface of the shock absorbing portion made of wood is covered with a rigid covering portion, and the shock absorbing portion is provided with a connecting portion that penetrates the shock absorbing portion in a direction orthogonal to the load input direction at the time of collision. The covering parts located at the positions sandwiching the above are connected to each other. As a result, the wood of the shock absorbing portion is restrained by the covering portion, and the covering portion itself is also suitably buckled at the time of collision, so that a high shock absorbing effect can be obtained. In addition, by integrally molding the covering portion and the connecting portion, the parts of the connecting portion and the assembly thereof are not costly.

It is desirable that the covering portion and the connecting portion are integrally molded with the same resin material.
As a result, the shock absorbing mechanism can be easily formed, and the weight of the shock absorbing mechanism itself can be reduced.

The shock absorbing portion is columnar, arranged so that the longitudinal direction is orthogonal to the load input direction, the cross section orthogonal to the longitudinal direction of the shock absorbing portion is rectangular, and the connecting portion is the widest surface of the above. It is desirable to connect the coverings together.
In this case, the covering portion on the widest surface is preferably buckled, and a high impact absorption effect can be obtained.

It is desirable that the width d of the connecting portion is d ≧ t with respect to the thickness t of the covering portion.
By ensuring the tensile strength of the connecting portion by setting the width of the connecting portion to be equal to or greater than the thickness of the covering portion, it is possible to prevent the connecting portion from breaking at the time of collision and the covering portion from being unable to restrain the wood of the shock absorbing portion.

The connecting portion is a first connection in which the distance a from the end face of the shock absorbing mechanism on the load input end side to the axis is a ≧ w / 2 with respect to the length w of the shock absorbing mechanism in the load input direction. It is desirable to include the portion and the second connecting portion in which the distance b from the end face to the axial center is b = a / 2 with respect to the distance a.
As a result, the entire surface of the covering portion connected by the connecting portion can be effectively utilized, and this can be appropriately buckled to realize the intended shock absorption.

The connecting portion includes a first connecting portion and a second connecting portion arranged at intervals in the load input direction, and the second connecting portion has a shock absorbing mechanism rather than the first connecting portion. The first and second connecting portions are located on the load input end side of the above, and a plurality of the first and second connecting portions are provided at intervals in a direction orthogonal to the load input direction, and are orthogonal to the load input direction of the first and second connecting portions. It is desirable that the distance c in the direction is c <b with respect to the distance b from the end face of the shock absorbing mechanism on the load input end side to the axial center of the second connecting portion.
As a result, the covering portion becomes more rigid in the direction orthogonal to the load input direction, and buckling of the covering portion in the load input direction can be promoted. Further, in the above case, since the distance between the connecting portions in the direction orthogonal to the load input direction is relatively small and densely provided, shock absorption due to buckling of the covering portion is performed regardless of the collision position of the colliding object and the size of the colliding object. There is also the advantage that the effect can be obtained.

According to the present invention, it is possible to provide a shock absorbing mechanism or the like capable of suitably performing shock absorption at low cost.

The schematic which shows the arrangement of the shock absorption mechanism 5. The figure which shows the shock absorption mechanism 5. The figure which shows the shock absorption mechanism 5. The figure which shows the wood of the shock absorbing part 7. The figure explaining the shock absorption by the shock absorption mechanism 5. The figure explaining the shock absorption by the shock absorption mechanism without a connecting part 11. The figure which shows the shock absorption mechanism 5a, 5b.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view showing the arrangement of the shock absorbing mechanism 5 of the vehicle 1 according to the embodiment of the present invention. The shock absorbing mechanism 5 is for absorbing the shock applied to the vehicle 1 at the time of the collision of the vehicle 1 to reduce the collision load. The type of vehicle 1 is not particularly limited.

The shock absorbing mechanism 5 is arranged in the front-rear direction of the vehicle along the metal body 3 on the side of the vehicle 1. The vehicle front-rear direction corresponds to the vertical direction shown in FIG. The left-right direction in FIG. 1 is the vehicle width direction, and is orthogonal to the vehicle front-rear direction in a plane.

2 and 3 are views showing the shock absorbing mechanism 5. FIG. 2 is a perspective sectional view of the shock absorbing mechanism 5, and FIG. 3 is a sectional view of the shock absorbing mechanism 5. FIG. 3A shows a horizontal cross section of the shock absorbing mechanism 5, and FIG. 3B shows a vertical cross section taken along line BB of FIG. 3A.

As shown in FIGS. 2 and 3, the shock absorbing mechanism 5 is a substantially rectangular parallelepiped member having a shock absorbing portion 7, a covering portion 9, a connecting portion 11, and the like, and has a longitudinal direction in the vehicle front-rear direction (depth direction in FIG. 2). , Corresponding to the vertical direction of FIG. 3 (a) and the paper surface normal direction of FIG. 3 (b)) so as to be in surface contact with the body 3 of the vehicle 1. The fixing method is not particularly limited. For example, mounting plates (not shown) are provided on the front and rear of the shock absorbing mechanism 5, and the mounting plates can be fastened to the body 3 with bolts.

In the present embodiment, at the time of a side collision of the vehicle 1, the collision load A is input from the side of the vehicle 1 toward the vehicle 1 as shown by the arrows in FIGS. That is. At the time of a side collision of the vehicle 1, the impact is absorbed by the impact absorbing mechanism 5 being crushed in the load input direction. By fixing the shock absorbing mechanism 5 to the body 3 with the longitudinal direction as the vehicle front-rear direction as described above, the shock absorbing mechanism 5 can receive the load A in a wide range in the longitudinal direction of the shock absorbing mechanism 5. Hereinafter, regarding the shock absorbing mechanism 5, the side where the collision load A is input (corresponding to the right side in FIGS. 2 and 3) is the load input end side, and the body 3 side (corresponding to the left side in FIGS. 2 and 3) is the fixed end. Sometimes called the side.

The shock absorbing portion 7 is a columnar member having a substantially rectangular parallelepiped shape, and is made of wood. The shock absorbing portion 7 is arranged with the longitudinal direction as the vehicle front-rear direction, and the longitudinal direction is orthogonal to the load input direction. The cross section orthogonal to the longitudinal direction of the shock absorbing portion 7 is rectangular, and the size of the cross section is appropriately set according to the required shock absorbing performance. However, in the examples of FIGS. The length (hereinafter referred to as the width) is larger.

It is desirable that the axial direction of the annual ring of the wood of the shock absorbing portion 7 (the fiber direction of the wood) corresponds to the load input direction. As a result, the wood is crushed while being compressed in the axial direction of the annual ring at the time of collision, so that the impact can be absorbed satisfactorily. However, the arrangement of wood is not limited to this.

The covering portion 9 covers the entire outer surface of the shock absorbing portion 7. The covering portion 9 protects the wood of the shock absorbing portion 7 from the outside world to prevent deterioration, and in the present embodiment, restrains the wood and prevents its splitting to secure the shock absorbing effect of the wood, and also buckles itself in the event of a collision. Thereby, it has a function of obtaining a further shock absorbing effect. The "outer surface (of the shock absorbing portion 7)" referred to here does not include the surface formed inside the shock absorbing portion 7. That is, as will be described later, a through hole 13 (see FIG. 4) is formed in the wood of the shock absorbing portion 7, and the inner surface of the through hole 13 is referred to as the “outer surface (of the shock absorbing portion 7)”. Does not include. As will be described later, a connecting portion 11 is provided on the inner surface of the inner surface instead of the covering portion 9.

The covering portion 9 is formed to have an equal thickness using, for example, a resin such as a fiber reinforced resin, and in the present embodiment, the covering portion 9 is made rigid. That is, the material constituting the covering portion 9 is made more rigid with respect to compression in the load input direction than the wood constituting the shock absorbing portion 7, or the covering portion 9 is shock-absorbed from the viewpoint of including the member shape. It is made stiffer than the part 7 with respect to compression in the load input direction. For the former comparison, for example, the elastic modulus (Young's modulus) is obtained by the compression test specified in JIS K7181 (Plastic-How to obtain compression characteristics) and JIS Z2101 (Wood test method), and comparison is performed using these. Just do it. Regarding the latter comparison, for example, for each of the covering portion 9 and the shock absorbing portion 7, the same compression test was performed separately on the entire cross section using an Instron universal tester, and the rigidity in the elastic region was determined from the relationship between the compressive force and the strain. And these may be used for comparison.

The connecting portion 11 is a columnar member that connects the covering portions 9 at positions sandwiching the shock absorbing portion 7. The connecting portion 11 penetrates the shock absorbing portion 7 in the vertical direction, that is, in the direction orthogonal to the load input direction and the longitudinal direction of the shock absorbing portion 7, and connects the covering portions 9 on the upper surface and the lower surface of the shock absorbing portion 7. As described above, since the cross section orthogonal to the longitudinal direction of the shock absorbing portion 7 is rectangular and has a width larger than the height, the upper surface and the lower surface of the shock absorbing portion 7 have the largest area of the outer surface of the shock absorbing portion 7. It will be a big side.

The connecting portion 11 is integrally molded with the covering portion 9 using the same material as the covering portion 9, and is continuous with the covering portion 9 without a boundary. Therefore, there are no connecting parts, adhesive parts, or the like between the covering portion 9 and the connecting portion 11.

A plurality of connecting portions 11 are provided at intervals in the longitudinal direction of the shock absorbing portion 7, which is a direction orthogonal to the load input direction, and a plurality of rows of the plurality of connecting portions 11 are arranged as one row (2 in the example of FIG. 3). The connecting portions 11 of the row) are arranged at intervals in the load input direction. In the example of FIG. 3, the connecting portion 11 (first connecting portion) on the fixed end side and the connecting portion 11 (second connecting portion) located on the load input end side of the connecting portion 11 are loaded. They are placed at overlapping positions when viewed from the direction.

Here, the distance a from the end surface of the shock absorbing mechanism 5 on the load input end side to the axis of the connecting portion 11 on the fixed end side is a ≧ w / 2 (distance a is) with respect to the width w of the shock absorbing mechanism 5. The width w is set to be 1/2 or more), and the connecting portion 11 on the fixed end side is located close to the body 3 of the vehicle 1. Further, the distance b from the end face to the axis of the connecting portion 11 on the load input end side is set so that b = a / 2 (distance b is 1/2 of the distance a) with respect to the distance a.

Further, the distance c between the axes of the connecting portions 11 adjacent to each other in the longitudinal direction of the shock absorbing portion 7 is c <b (with respect to the distance b) at each of the connecting portions 11 on the load input end side and the fixed end side. The interval c is smaller than the distance b). Further, the width d of the connecting portion 11 is determined so that d ≧ t (the width d is the thickness t or more) with respect to the thickness t of the covering portion 9.

As described above, the connecting portion 11 is integrally molded with the same material as the covering portion 9. At this time, as shown in FIG. 4, a wood having a through hole 13 formed at a position corresponding to the connecting portion 11 is placed in a cavity of an injection molding machine (not shown) as described in, for example, Japanese Patent Application Laid-Open No. 2018-89775. The resin, which is a molding material, is injected into the cavity. The resin covers the entire outer surface of the wood to form the covering portion 9, and also flows into the through hole 13 of the wood to form the connecting portion 11.

FIG. 5A is a diagram showing a shock absorbing mechanism 5 in a state where a collision load A due to a colliding object 2 is applied, in the same cross section as in FIG. 3B. In the present embodiment, when the collision load A is applied to the shock absorbing mechanism 5 as shown by the arrow in FIG. 5A, the wood of the shock absorbing portion 7 is compressed and crushed in the load input direction while being restrained by the covering portion 9. ..

Since the covering portions 9 on the upper surface and the lower surface of the shock absorbing portion 7 are connected by the connecting portion 11, they do not peel off from the wood at the position of the connecting portion 11. Further, at the time of collision, the connecting portion 11 on the load input end side induces the formation of the node 12 on the load input end side, and the connecting portion 11 on the fixed end side induces the formation of the node 12 on the fixed end side, so that the covering portion 9 is formed. It buckles as shown in the figure.

FIG. 5B is a diagram schematically showing the relationship between the displacement of the shock absorbing mechanism 5 in the collision process and the load, with the vertical axis representing the load and the horizontal axis representing the displacement of the shock absorbing mechanism 5. The load is a load that the shock absorbing mechanism 5 receives at the time of a collision, and is a load that is absorbed when the shock absorbing mechanism 5 is crushed. The displacement of the shock absorbing mechanism 5 is the amount of shrinkage of the shock absorbing portion 7 in the load input direction due to the compression of the wood.

In FIG. 5B, the shock absorption effect of the shock absorption mechanism 5 is represented by the integrated value of the load due to displacement. The shock absorbing effect of the shock absorbing mechanism 5 can be largely divided into those due to the compression of the wood of the shock absorbing portion 7, those due to the out-of-plane deformation of the covering portion 9, and those due to the buckling of the covering portion 9. , 17 and 19 show the impact absorption effect due to each phenomenon.

When the shock absorbing mechanism 5 of the present embodiment is used, a large shock absorbing effect 15 is obtained by compressing the wood of the shock absorbing portion 7 at the initial stage of the collision. At the initial stage of collision, the impact is absorbed by the out-of-plane bending of the covering portion 9, but the impact absorption effect 17 is small. After that, as the collision process progresses, the shock absorbing effect 15 due to the compression of the wood gradually decreases, while the buckling of the covering portion 9 occurs, so that a large shock absorbing effect 19 can be obtained.

On the other hand, as shown in FIG. 6A, if there is no connecting portion 11, when the collision load A is applied, the covering portion 9 is largely peeled off from the wood and the out-of-plane bending is predominant, and the covering portion 9 is greatly cracked or torn. In some cases. On the other hand, in the shock absorbing mechanism 5, the presence of the connecting portion 11 suppresses out-of-plane bending and cracking of the covering portion 9 to be partially suppressed, so that the covering portion 9 can be suitably guided to buckling.

FIG. 6 (b) shows the relationship between the displacement and the load in the collision process for the shock absorbing mechanism without the connecting portion 11 shown in FIG. 6 (a), as in FIG. 5 (b).

Also in this case, similarly to the above, the impact absorption effect 15 due to the compression of the wood of the impact absorption portion 7 and the impact absorption effect 17 due to the out-of-plane bending of the covering portion 9 occur at the initial stage of the collision, and the former impact absorption as the collision process progresses. Effect 15 gradually decreases. However, in this example, since there is no connecting portion 11, the covering portion 9 is peeled off to the outside of the wood exclusively by out-of-plane bending, and even if the collision process progresses, the large impact absorption effect 19 due to the buckling of the covering portion 9 as described above is obtained. I can't get it. As a result, the shock absorbing effect as a whole is lower than that of the shock absorbing mechanism 5 having the connecting portion 11.

As described above, according to the present embodiment, the entire outer surface of the shock absorbing portion 7 made of wood is covered with the rigid covering portion 9, and the shock absorbing portion 7 is formed in the direction orthogonal to the load input direction at the time of collision. The covering portions 9 located at positions sandwiching the shock absorbing portion 7 are connected to each other by the connecting portion 11 penetrating the above. As a result, the wood of the shock absorbing portion 7 is restrained by the covering portion 9, and the covering portion 9 itself is suitably buckled at the time of a collision, so that a high shock absorbing effect can be obtained. In addition, by integrally molding the covering portion 9 and the connecting portion 11, it is possible to eliminate the cost of parts and assembly of the connecting portion.

Further, in the present embodiment, the covering portion 9 and the connecting portion 11 are integrally molded of the same resin material, whereby the shock absorbing mechanism 5 can be easily formed, and the shock absorbing mechanism 5 itself can be reduced in weight.

Further, in the present embodiment, the covering portions 9 on the upper surface and the lower surface, which are the widest outer surfaces of the shock absorbing portion 7, are connected by the connecting portion 11, and the covering portions 9 on the upper surface and the lower surface are preferably buckled at the time of a collision, which is high. A shock absorbing effect can be obtained.

Further, in the present embodiment, by setting the width d of the connecting portion 11 to be equal to or greater than the thickness t of the covering portion and ensuring the tensile strength of the connecting portion 11, the connecting portion 11 is broken at the time of collision, and the covering portion 9 causes the shock absorbing portion 7 to break. It is possible to prevent the wood from becoming unrestrained. When the width d of the connecting portion 11 is set to be equal to or larger than the thickness t of the covering portion, the fluidity of the resin into the through hole 13 (see FIG. 4) at the time of integral molding can be ensured, and the shock absorbing mechanism 5 is manufactured. It is also preferable in terms of aspects.

Further, in the present embodiment, regarding the position of the connecting portion 11 on the fixed end side, the distance a from the end face on the load input end side of the shock absorbing mechanism 5 to the axial center is a ≧ w / with respect to the width w of the shock absorbing mechanism 5. With respect to the position of the connecting portion 11 on the load input end side, the distance b from the end face to the axial center is b = a / 2 with respect to the distance a, so that the upper surface connected by the connecting portion 11 and the upper surface and the connecting portion 11 are connected. With respect to the covering portion 9 on the lower surface, the entire surface thereof can be effectively utilized and buckled appropriately to realize the intended shock absorption.

Further, since the distance c between the connecting portions 11 in the longitudinal direction of the shock absorbing portion 7 orthogonal to the load input direction is c <b with respect to the above distance b, the covering portion 9 is more rigid in the longitudinal direction. Therefore, buckling in the load input direction orthogonal to the longitudinal direction can be promoted. Further, in the above case, since the distance c between the connecting portions 11 is relatively small and densely provided, the impact absorbing effect due to the buckling of the covering portion 9 can be obtained regardless of the collision position of the colliding object 2 and the size of the colliding object 2. There is also an advantage.

However, the present invention is not limited to the above embodiments. For example, the shape of the shock absorbing portion 7, the arrangement and the number of the connecting portions 11 and the like are not limited to those shown in FIG. 3A and can be variously determined according to the purpose. For example, as shown in the shock absorbing mechanism 5a of FIG. 7A, the connecting portion 11 on the load input end side and the connecting portion 11 on the fixed end side are arranged in a staggered pattern so that they do not overlap when viewed from the load input direction. It may be. Further, in some cases, as shown in the shock absorbing mechanism 5b of FIG. 7B, it is possible to arrange only one row of connecting portions 11.

Further, the resin used for the covering portion 9 is not particularly limited, and the covering portion 9 and the connecting portion 11 can be integrally molded with a metal or the like instead of the resin.

In addition, the arrangement of the shock absorbing mechanism 5 is not limited to that described in FIG. 1 and the like, and it is possible to install the shock absorbing mechanism 5 in an appropriate arrangement in each part of the vehicle 1 where the input of the collision load is expected, and it is possible to install it inside the vehicle 1. It is also possible to provide it. For example, assuming that the collision load is input in the front-rear direction of the vehicle, the shock absorbing mechanism 5 can be fixed to the front or rear of the vehicle 1, and the shock absorbing mechanism 5 is arranged, for example, with the longitudinal direction as the vehicle width direction. can do.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical idea disclosed in the present application, and these also naturally belong to the technical scope of the present invention. Understood.

1: Vehicle 3: Body 5, 5a, 5b: Shock absorbing mechanism 7: Shock absorbing part 9: Covering part 11: Connecting part

Claims (6)

It is a vehicle shock absorption mechanism for reducing the collision load applied to the vehicle.
A shock absorber made of wood and
A covering portion that covers the entire outer surface of the shock absorbing portion and a coating portion that covers the entire outer surface of the shock absorbing portion.
A connecting portion that penetrates the shock absorbing portion in a direction orthogonal to the load input direction to which the collision load is applied and connects the covering portions at positions sandwiching the shock absorbing portion, and a connecting portion.
Equipped with
The covering is more rigid with respect to compression in the load input direction than the shock absorbing part, or the material constituting the covering is more rigid with respect to compression in the load input direction than the wood constituting the shock absorbing part. Rigid and
A shock absorbing mechanism characterized in that the covering portion and the connecting portion are integrally molded so that the connecting portion is continuous with the covering portion without a boundary. The shock absorbing mechanism according to claim 1, wherein the covering portion and the connecting portion are integrally molded of the same resin material. The shock absorbing portion has a columnar shape and is arranged so that the longitudinal direction is orthogonal to the load input direction.
The cross section orthogonal to the longitudinal direction of the shock absorbing portion is rectangular.
The shock absorbing mechanism according to claim 1 or 2, wherein the connecting portion connects the covering portions having the widest surface to each other. The shock absorbing mechanism according to any one of claims 1 to 3, wherein the width d of the connecting portion is d ≧ t with respect to the thickness t of the covering portion. The connecting part
The first connecting portion where the distance a from the end face on the load input end side of the shock absorbing mechanism to the axis is a ≧ w / 2 with respect to the length w in the load input direction of the shock absorbing mechanism.
With the second connecting portion where the distance b from the end face to the axis is b = a / 2 with respect to the distance a.
The shock absorbing mechanism according to any one of claims 1 to 4, wherein the shock absorbing mechanism comprises. The connecting portion includes a first connecting portion and a second connecting portion arranged at intervals in the load input direction.
The second connecting portion is located closer to the load input end side of the shock absorbing mechanism than the first connecting portion.
A plurality of the first and second connecting portions are provided at intervals in a direction orthogonal to the load input direction.
The distance c in the direction orthogonal to the load input direction of the first and second connecting portions is c with respect to the distance b from the end surface of the shock absorbing mechanism on the load input end side to the axial center of the second connecting portion. The shock absorbing mechanism according to any one of claims 1 to 5, wherein <b.

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