JPH07277222A - Energy absorbing member - Google Patents

Abstract

PURPOSE:To prevent an excessive shock to a passenger and a structure to be protected by overlapping an opening part formed in a core side wall and a part where a deflection is caused at the beginning of the buckling of the side wall to reduce the generation of excessive reaction at the beginning of the deformation of the core side wall for buckling the opening part and the side wall while absorbing collision energy. CONSTITUTION:A core side wall 1a being severally H and A in the length and width of a member is pressure-destroyed with its buckling to absorb a shock which is caused by collision and given in the direction of the axial center of a core. The side wall 1a has a point separating as far as a distance X from the end 1C on a collision side as a central position, and is formed so that an opening part 1b having the maximum opening width Y may satisfy such a formula as 0.2A<=X<=A<H/2, 0.2A<=Y<=0.5A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy absorbing member which absorbs a shock at the time of collision by buckling the side wall of a core while crushing it.

[0002]

2. Description of the Related Art For example, a vehicle may collide with a vehicle stop wall laid on the ground or vehicles. In particular, it is considered that high-speed vehicles need energy absorbing members that absorb impacts between the front end and passenger seats and between vehicles to protect passengers and structures from impacts due to collisions (for example, TGV in France and Hong Kong). Subway).

As a conventional energy absorbing member, for example, a honeycomb panel in which an aggregate of cores having a honeycomb shape or a pipe shape in cross section is interposed between flat plates, or a structure in which a large number of pipe-shaped panels are laminated is adopted. There is. The energy absorbing member is arranged in the high-speed vehicle so that the collision direction and the axis of each core of the panel coincide with each other, and at the time of collision, the side wall of the core is buckled and crushed to reduce the collision energy. It is designed to absorb and reduce the impact on passengers and structures. In addition, the energy absorbing member,
It may also be installed in automobiles. Conventionally, an energy absorbing member consisting of a single pipe-shaped core is arranged in the engine room, and the collision energy is absorbed by the same operation as described above to absorb occupants and structures. It is designed to relieve the shock (see Fig. 5).

[0004]

However, in the above conventional energy absorbing member, as shown in FIG. 6, an excessive reaction force (Fmax) is generated at the initial stage of deformation when the side wall of the core begins to buckle, and Prior to absorbing the collision energy, the passenger, the occupant, and the structure to be protected are impacted and cause significant damage.

Therefore, conventionally, in order to easily buckle the energy absorbing member at the time of a collision, the energy absorbing member is preliminarily deformed by D ₁ or more by pre-crash processing, or the core is given an initial incorrect amount of energy. A method of manufacturing the absorbent member has been proposed.

However, in the case of pre-crash treatment, it is necessary to buckle the entire energy absorbing member,
There is a problem in that the load required for processing increases as the area of the energy absorbing member increases, and the processing cost rises due to an increase in the size of the pressing device. Further, when the energy absorbing member is made of the core having the initial incorrect amount, it is necessary to give the initial incorrect amount at the time of molding the core portion, which increases the number of steps and the poor adhesion between the core and the flat plate. Is likely to occur.

Therefore, the present invention provides an energy absorbing member which does not generate an excessive reaction force (Fmax) in the initial stage of deformation when the side wall of the core starts to buckle and can be reliably manufactured at low cost. Is what you are trying to do.

[0008]

In order to solve the above-mentioned object, the side wall of the core having the member length H and the member width A is buckled and crushed, so that the impact due to the collision given in the axial direction of the core is generated. The energy absorbing member that absorbs is characterized by the following.

That is, an opening portion having a maximum opening width Y with the distance X from the end portion on the collision side as the center position is formed on the side wall.
It is characterized in that it is formed so as to satisfy 0.2A ≦ X ≦ A <H / 2 and 0.2A ≦ Y ≦ 0.5A.
Further, preferably 0.3A ≦ X ≦ 0.6A, 0.3A
It is characterized in that it is formed so as to satisfy ≦ Y ≦ 0.5A.

[0010]

The opening formed on the side wall of the core is 0.2A ≦
Since it is formed so as to satisfy the conditions of X ≦ A <H / 2 and 0.2A ≦ Y ≦ 0.5A, it overlaps with the portion where the side wall is bent when buckling starts. Therefore, an excessive reaction force does not occur at the initial stage of deformation when the side wall of the core starts to buckle, and the absorbed energy becomes good. In particular, 0.3A ≦ X ≦ 0.6A, 0.3A ≦ Y ≦
By being formed so as to satisfy 0.5A, it becomes possible to prevent an excessive reaction force at the initial stage of deformation and obtain good absorbed energy.

That is, since buckling does not easily occur from both ends or the center of the length of the core, the distance X from the end is 0.2 A.
As described above, the opening is provided at a position away from the center H / 2.
Further, in order to reduce the value of F _max to within 1.5 times F _mean , the opening width Y needs to be 0.2 A or more,
If it exceeds 0.5 A, the absorbed energy decreases, which is not preferable as an energy absorbing member.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. The energy absorbing member according to the present embodiment is arranged at the front or middle portion of a transportation machine such as a train, an airplane or an automobile, and absorbs collision energy when the transportation machine collides. As shown in FIG. 3, this energy absorbing member is joined to a core plate 2 in which a large number of honeycomb-shaped cores 1 made of an aluminum alloy, an iron system, or another metal are assembled, and an upper surface and a lower surface of the core plate 2. It is formed by stacking honeycomb panels 5 composed of flat plates 3 and 4.

All the side walls 1a of the core 1 are shown in FIG.
As shown in (a) and (b), circular openings 1b are formed. The opening 1b may have an elliptical shape or a polygonal shape. The formation position and the opening width of the opening 1b are, as shown in FIG. 1, the distance from the end 1c closest to the load-bearing portion to the center position of the opening 1b being X, and the diameter of the opening 1b. Is set to Y, it is set to satisfy the conditions of the expressions (1) and (2). 0.2A ≦ X ≦≦ A <H / 2 (1) 0.2A ≦ Y ≦ 0.5A (2)

In addition, H represents the height (member length) of the side wall 1a, and A represents the width (member width) of the side wall 1a. Further, in the present embodiment, the diameter Y is the opening width, but when the opening 1b is elliptical or polygonal, the width Y of the side wall 1a is the opening width. Become. Further, the energy absorbing member in the present embodiment is formed by stacking a plurality of honeycomb panels 5 in which a large number of cores 1 are assembled, but the present invention is not limited to this and, for example, as shown in FIG. In addition, it may consist of one pipe-shaped core 1.

A case of producing the energy absorbing member in the above structure will be described. First, a gear-shaped press die having a punching portion that forms the opening 1b set under the above conditions is prepared. Then, the press die is mounted on a press machine, and a long plate having a width of H is supplied to the press machine. As a result, as shown in FIG. 4, a core plate 6 in which trapezoidal irregularities are alternately repeated is formed. Will be formed. At this time, since the press die has a punched portion, the core plate 6 is formed by pressing, and at the same time, the opening 1b is formed. Therefore, depending on the formation of the opening 1b, the step 2 is not added and the core plate 6 is not distorted.

When the core plate 6 is produced, the core plates 6 are joined so that the top portions 6a, 6a of the core plates 6 come into contact with each other, thereby forming the core plate 2 in which a large number of honeycomb-shaped cores 1 ... Will be done. After that, as shown in FIG. 3, the flat plates 3 and 3 are bonded to the upper surface and the lower surface of the core plate 2, respectively, and they are bonded by brazing while being vacuumed. At this time, the opening 1b formed on the side wall of the core plate 2 exhibits a function as a ventilation hole during vacuum suction. Further, since the core plate 6 is not distorted, the upper surface and the lower surface of the core plate 2 are joined together over the entire surface. Therefore, the honeycomb panel 5 in which the core plate 2 and the flat plates 3 and 3 are sufficiently adhered is produced. Then, by stacking a plurality of honeycomb panels 5 so that the openings 1b are located on the same side, an energy absorbing member is created.

Next, the operation of the energy absorbing member will be described. When a transport aircraft equipped with an energy absorbing member collides, the impact of this collision is the core 1 of the energy absorbing member.
Will be applied in the axial direction. The effective width immediately after buckling of the energy absorbing member to which this impact is applied is approximately 1 /
In the range of 2, the buckling occurs at a buckling pitch of about 0.7 A from the side closer to the load applying part (collision site). At this time, as shown in FIG. 1, an opening 1b is formed on each side wall 1a of the core 1 so as to satisfy the above X and Y, and the opening 1b bends when buckling starts. It will overlap with the part. Therefore, the side wall 1a of the core 1 buckles while absorbing the collision energy without generating an excessive reaction force (Fmax) at the initial stage of deformation when the buckling starts. This reduces excessive impact on passengers and the structure to be protected, thus minimizing damage.

Next, X which exerts the above-mentioned effects.
In order to determine the conditions of Y and Y, the following crush test was performed. First, a honeycomb panel 5 having a core 1 having an opening 1b in which X is 0.2 A and Y is 0.2 A was prepared. Similarly, X is 0.3A, 0.5A, 0.6A, H
/ 2 and Y was 0.3A, 0.5A, and a honeycomb panel 5 including the core 1 having the opening portion 1b of 0.6A was prepared.

After that, a crushing load when the core 1 buckles was measured while applying a load to the produced honeycomb panel 5. Then, the maximum value (F _max ) and the average value (F _mean ) of the crushing load are obtained, and the characteristic value (F _mean ) is obtained by dividing the maximum value (F _max ) by the average value (F _mean ) as shown in equation (3). α)
I asked. The average value (F _mean ) is the average crush load calculated from the amount of energy absorbed until the honeycomb panel 5 is crushed by 75%, and the characteristic value (α).
Indicates that the closer to 1, the better the crushing property. The results of this measurement are shown in Table 1. The normal characteristic value (α) in the case of not having the opening 1b is 2.5 to 3.0. α = F _max / F _mean (3)

[0020]

[Table 1]

From the above measurement results, the minimum value of the characteristic value (α) is a range in which X is 0.2 A or more and less than H / 2 and Y is 0.2 A or more and 0.5 A or less, preferably. X is 0.3 A or more and less than 0.6 A, and Y is 0.3 A
It was confirmed that it exists in the range of 0.5 A or less. That is, X is 0.2 A or more and less than H / 2, Y is 0.2 A
If set in the range of 0.5 A or more, the characteristic value (α)
Exists in the range from "1.48" when X is 0.6A and Y is 0.2A to "1.05" when X is 0.5A and Y is 0.3A. confirmed. In addition, X is 0.3 A or more and less than 0.6 A, and Y is 0.3
When set in the range from A to 0.5 A, the characteristic value (α)
Can be in the range of "1.25" when X is 0.6A and Y is 0.5A to "1.05" when X is 0.5A and Y is 0.3A. confirmed. When Y is 0.6 or more, the characteristic value (α) becomes a value smaller than 1, the reaction force increases as the deformation progresses, and the energy absorption amount decreases, and the energy absorption member is reduced. It was also confirmed that it would be inappropriate.

As a result, the above equations (1) and (2) are obtained.
By forming the honeycomb panel 5 including the core 1 having the X and Y openings 1b satisfying the condition of the equation and using the honeycomb panel 5 to form the energy absorbing member, an excessive reaction at the time of collision can be achieved. It was confirmed that the force (Fmax) is prevented and a sufficient amount of energy absorption is obtained.

As described above, the energy absorbing member of this embodiment has the sidewall 1a of the core 1 having the height H and the width A.
By collapsing while buckling, the impact due to the collision given in the axial direction of the core 1 is absorbed, and the side wall 1a has a distance X from the collision side end 1c as a central position, The opening 1b having a width of Y is 0.2
It is formed so as to satisfy A ≦ X ≦ A <H / 2 and 0.2A ≦ Y ≦ 0.5A.

As a result, the opening 1b formed in the side wall of the core 1 overlaps with the portion of the side wall 1a that is bent when the buckling starts, so that an excessive reaction force is generated at the initial stage of deformation when the side wall 1a starts buckling. Never. Therefore, by buckling while absorbing the collision energy, it is possible to reduce the excessive impact on the passengers and the structure to be protected, and to minimize the damage. Further, since the opening 1b prevents the generation of an excessive reaction force in the initial stage of deformation, a process for causing the core 1 to be distorted is unnecessary, and as a result, it is possible to reliably manufacture at low cost. Since the opening 1b can be formed simultaneously with the formation of the core 1, it is possible to manufacture without increasing the number of steps. In the case of brazing, it is necessary to provide a gas vent hole, but normally,
Since the diameter is as small as 0.1 A, the crushing property cannot be improved. On the other hand, in the present embodiment, the opening 1b
Is formed so as to satisfy the above condition,
It is possible to obtain degassing and good crushing properties.

[0025]

As described above, according to the present invention, 0.2A ≦ X ≦ A <H / 2, 0.2A is provided on the side wall of the energy absorbing member.
Since the opening is formed so as to satisfy ≦ Y ≦ 0.5A, the opening and the portion of the side wall that is bent when buckling starts to overlap each other, and the side wall of the core is buckled. In the initial stage of deformation that starts, buckling occurs while absorbing collision energy without generating an excessive reaction force.

As a result, it is possible to reduce the excessive impact on the passengers and the structure to be protected and to minimize the damage. Further, since the opening prevents the generation of an excessive reaction force in the initial stage of deformation, a process for causing the core to be distorted is unnecessary, and as a result, it is possible to reliably manufacture at low cost, Since the formation can be performed at the same time as the formation of the core, there is an effect that it can be manufactured without increasing the number of steps.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a positional relationship of openings formed on a side wall of an energy absorbing member.

FIG. 2 shows an energy absorbing member, (a)
Is a front view and (b) is a plan view.

FIG. 3 is a front view of a honeycomb panel.

FIG. 4 is an explanatory diagram showing a state of a core plate.

FIG. 5 is an explanatory diagram showing a state in which the energy absorbing member is mounted on an automobile.

FIG. 6 is a graph showing the relationship between the reaction force of the energy absorbing member and the amount of deformation.

[Explanation of symbols]

 1 core 1a side wall 1b opening 1c end 2 core plate 3 flat plate 4 flat plate 5 honeycomb panel 6 core plate

Claims (1)

[Claims] 1. An energy absorbing member for absorbing a shock due to a collision applied in the axial direction of the core by buckling and collapsing the side wall of the core having a member length H and a member width A. Is centered on the distance X from the end on the collision side, and the opening with the maximum opening width Y satisfies 0.2A ≦ X ≦ A <H / 2 0.2A ≦ Y ≦ 0.5A. An energy absorbing member characterized by being formed in.