JP2014141977A - Energy absorption member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an energy absorption member that has high energy absorption efficiency and can freely adjust a degree of energy absorption.SOLUTION: An energy absorption member 11 is made a metal plate material that has high rigidity and can plastically deform to absorb kinetic energy applied from outside. The energy absorption member 11 is formed in a cylindrical shape and buckles to absorb energy applied in the direction of a virtual axis 17 of the cylindrical shape. In the energy absorption member 11, a plurality of bulge parts 13 are formed so as to be adjacent to or close to one another in a plate-like member, and the bulge parts 13 protrude toward the inside of the cylindrical shape.

Description

  The present invention relates to an energy absorbing member such as a component of an automobile bumper.

  2. Description of the Related Art Conventionally, an automobile is provided with a mechanism for preventing an external impact applied to a body at the time of a collision. For this reason, conventionally, the front side member front end and bumper stay of an automobile are formed into a cylindrical shape by providing a plurality of substantially circular projections on the plate surface of a plate-like member such as aluminum or steel, and the axial direction is the front-rear direction. An energy absorbing member provided along the line is known.

  This energy absorbing member absorbs an impact at the time of collision by buckling against a force applied in the cylindrical axial direction. Here, if the energy absorbing member is bent with respect to the cylindrical axial direction during buckling, the energy absorption efficiency is deteriorated. Furthermore, it is desirable that the energy absorbing member has sufficient strength. In general, various measures have been devised to improve axial resistance, such as by making it polygonal by a method such as pressing or extrusion, but the strength and behavior at which the cylindrical member buckles and deforms, Since it is determined passively depending on the length, thickness, and material of the wall, the mainstream is one that considers these optimizations.

  Further, when trying to increase the total energy absorption amount, the axial drag tends to increase at the initial stage of the collision, which has become a foothold in reducing the obstacle value to the occupant. Therefore, such an energy absorbing member is required to have characteristics that are low in the initial stage of the collision and that continue to exhibit sufficient drag over the entire length of the stroke.

  Therefore, as a method of actively controlling the strength and behavior of the cylindrical member to buckle and deform without depending only on the wall length, plate thickness, and material, a plurality of members at a predetermined position of the plate member have been conventionally used. There is known a configuration in which a bulging portion having a substantially circular shape when viewed from the front is formed outward in a cylindrical shape (see, for example, Patent Document 1).

JP 2001-73220 A

  However, the invention described in Patent Document 1 has a configuration in which the bulging portion protrudes outward from the cylindrical shape on the plate surface of the energy absorbing member. This configuration is effective in terms of reducing initial drag and stable energy absorption, but increases the total amount of energy absorption compared to specifications made of flat plates with no bulges. Cannot be obtained.

  This invention is made | formed in view of said problem, and makes it a subject to provide the energy absorption member which has high energy absorption efficiency and can adjust the degree of energy absorption freely.

  In order to achieve such an object, the invention described in claim 1 is a member that is formed in a cylindrical shape and absorbs energy applied in the cylindrical axial direction by buckling, and a plurality of plate-like members are provided. The bulging portion is formed adjacent to or close to the bulging portion, and the bulging portion protrudes inward of the cylindrical shape.

  The invention described in claim 2 is characterized in that, in addition to the configuration described in claim 1, each of the bulging portions is formed in a polygon in a front view having the same outer shape.

  According to a third aspect of the present invention, in addition to the configuration according to the second aspect, the bulging portion has an outer shape formed in a substantially circular shape when viewed from the front.

    According to a fourth aspect of the present invention, in addition to the configuration according to the second aspect, the bulging portion has an outer shape formed in a rectangular shape in front view, a ridge line is formed along one diagonal line, and another diagonal line is formed. A valley line is formed along the line.

  According to a fifth aspect of the present invention, in addition to the configuration according to any one of the first, second, and fourth aspects, the energy absorbing member is formed so that the bulging portion is adjacent to the entire surface without a gap over substantially the entire surface. It is characterized by that.

  According to a sixth aspect of the present invention, in addition to the structure according to any one of the first to fifth aspects, the vehicle body strength member of the automobile and a bumper reinforcing member along the vehicle width direction are disposed. Features.

  According to the first aspect of the present invention, the plate-like member is formed in a state where a plurality of bulges are adjacent or close to each other, thereby adjusting the shape and size of the bulges. The buckling state and the buckling strength when the member is impacted can be freely adjusted so as to be in an appropriate state. In addition, since the bulging portion is formed in a state adjacent or close to each other, when an impact is applied to the energy absorbing member, the energy absorbing member can be prevented from being bent and can be buckled uniformly in the axial direction. . Furthermore, when the bulging part protrudes toward the inside of the cylinder, when the plate-like member buckles, the impact is absorbed with high energy absorption efficiency due to the interference reaction force effect between the bulging parts adjacent to each other. can do. Thereby, energy absorption efficiency is high and the energy absorption member which can adjust the degree of energy absorption freely can be formed.

  According to the second aspect of the present invention, each of the bulging portions is formed in a polygonal shape in front view having the same outer shape, so that an impact applied from the outside toward the plate surface direction of the energy absorbing member can be prevented. The drag can be increased. Further, when the energy absorbing member is buckled, bending with respect to the cylindrical axial direction is less likely to occur. Furthermore, since each bulge part is the same shape, manufacture is easy. Thereby, an energy absorption member with high energy absorption efficiency can be formed easily.

  According to the third aspect of the present invention, since the bulging portion is formed in a substantially circular shape when viewed from the front, the bulging portion can increase the resistance to an impact applied from multiple directions outside the energy absorbing member. Thereby, an energy absorption member with high energy absorption efficiency can be formed more easily.

  According to the invention described in claim 4, the bulging portion has an outer shape that is rectangular in a front view, a ridge line is formed along one diagonal line, and a valley line is formed along another diagonal line. Thereby, the resistance to the impact applied from the outside toward each diagonal direction of the energy absorbing member can be increased. Thereby, a small-sized energy absorption member with high energy absorption efficiency can be formed more easily.

  According to the invention of claim 5, the energy absorbing member is formed over substantially the entire surface and adjacent to the bulging portion without a gap, so that the energy absorbing member has a high resistance to impact over substantially the entire surface of the energy absorbing member, Adjustment of energy absorption efficiency can be easily formed. Thereby, an energy absorption member having high energy absorption efficiency and capable of freely adjusting the degree of energy absorption can be formed more easily.

  According to the sixth aspect of the present invention, the impact force acting on the bumper during a vehicle collision can be effectively absorbed by the energy absorbing member, and the impact force transmitted to the vehicle body strength member can be reduced as much as possible.

It is a figure which shows the whole energy absorption member shape of this Embodiment 1. FIG. It is an enlarged view of the circle mark A part of the energy absorption member which concerns on the same embodiment. It is a BB end view of the energy absorption member concerning the embodiment. It is CC end view of the energy absorption member which concerns on the same embodiment. It is a figure which shows the experimental result of the energy absorption state of the energy absorption member which concerns on the same embodiment, and the conventional energy absorption member. It is a figure which shows the experimental result of the energy absorption state of the energy absorption member which concerns on the same embodiment, and the conventional energy absorption member. It is the elements on larger scale of the motor vehicle to which the energy absorption member of this Embodiment 1 and 2 is applied. It is a figure which shows the whole energy absorption member of this Embodiment 2. FIG. It is an enlarged view of the circle mark D part of the energy absorption member which concerns on the embodiment. It is an EE end elevation of the energy absorbing member according to the same embodiment. It is a FF end elevation of the energy absorption member concerning the embodiment.

<Embodiment 1 of the Invention>
1 to 7 show a first embodiment of the present invention.

  First, the structure will be described. The energy absorbing member 11 of the first embodiment shown in FIG. 1 is used for absorbing shocks of a bumper of the automobile 100. Specifically, as shown in FIG. 7, the energy absorbing member 11 includes a side member 102 as a “body strength member” that extends in the vehicle front-rear direction below the side of the engine room 101 of the automobile 100 and a bumper skin 103. A bumper reinforcing member 104 extending along the vehicle width direction is disposed along the vehicle longitudinal direction.

  5 shows a configuration in which the energy absorbing member 11 is provided between the front side member 102 and the bumper reinforcing member 104 of the automobile 100, the energy absorbing member 11 is a rear side member (see FIG. 5). (Not shown) and a bumper reinforcing member (not shown) may be provided.

  The energy absorbing member 11 is formed of a metal plate material having high rigidity and capable of absorbing kinetic energy applied from the outside by plastic deformation. In the first embodiment, the energy absorbing member 11 is formed of a single aluminum plate having a thickness of about 1.8 millimeters. However, the energy absorbing member 11 may be formed of any material as long as it has good properties of rigidity and kinetic energy absorption characteristics. For example, it can also be formed of a metal other than aluminum, such as a steel plate, an aluminized steel plate, a laminate of an aluminum plate and a resin film material, a resin, and a plywood thereof.

  The energy absorbing member 11 is formed by pressing, but may be formed by any other processing method.

  As shown in FIG. 1, the energy absorbing member 11 is formed in a cylindrical shape. The energy absorbing member 11 is hollow and has openings 12 and 12 at both ends.

  The energy absorbing member 11 is fixed to the side member 102 and the bumper reinforcing member 104 with a bolt or the like (not shown). Thereby, the virtual axis 17 is disposed so as to face the front-rear direction of the automobile 100. The energy absorbing member 11 is not limited to a cylindrical shape, and may have a polygonal cylindrical shape such as a rectangular cylindrical shape, a pentagonal cylindrical shape, or a hexagonal cylindrical shape in plan view (that is, viewed from the opening side). May be. Moreover, the inside of the energy absorbing member 11 may be partitioned by a partition member extending in the axial direction. Further, the energy absorbing member 11 may be fixed to the side member 102 and the bumper reinforcing member 104 in any configuration.

  However, any shape and structure can be used as long as it has good rigidity and kinetic energy absorption characteristics. For example, a shape in which plate materials are provided at both ends and the internal space is sealed may be used, or a material such as urethane may be filled inside to form a cylindrical shape or a rectangular tube shape. .

  As shown in FIG. 1, a plurality of bulging portions 13 are formed on substantially the entire plate surface of the energy absorbing member 11 by press working. The bulging portion 13 of the energy absorbing member has a polygonal shape when viewed from the front. In the first embodiment, as shown in FIG. 2, all the bulging portions 13 are formed in the same shape. That is, each bulging part 13 has the same external shape as a hexagonal shape when viewed from the front, and the size of the bulging is the same.

  As shown in FIGS. 3 and 4, each bulging portion 13 bulges inward from the virtual outer surface 18 indicated by a two-dot chain line in the drawing of the energy absorbing member 11. As shown in FIG. 2, a ridge line 14 that is inclined toward the inside of the energy absorbing member 11 is formed on a line connecting the three opposing corners of the bulging portion 13 as shown in FIGS. 3 and 4. . The ridge line 14 is a ridge line when viewed from the inside of the energy absorbing member 11, but is a valley line when viewed from the outside. As shown in FIGS. 3 and 4, these ridge lines 14 form a curve that curves inward, and the intersection 15 of the ridge lines 14 is the highest point in the bulging direction. A surface surrounded by the two ridge lines 14 and 14 of the bulging portion 13 and one side 16 of the outer shape forms a plane. All the adjacent bulging portions 13 are adjacent to each other without a gap.

  The bulging portion 13 is formed in a shape that absorbs kinetic energy due to an impact received when the automobile 100 collides. In the first embodiment, one side of the outer shape of the bulging portion 13 is 8 millimeters and the height is 2 millimeters. However, the bulging portion 13 may be formed in any outer shape and height as long as energy absorption is satisfactory.

  Moreover, when the energy absorption member 11 buckles, the bulging part 13 is arrange | positioned in the aspect which a cylindrical axial direction does not bend easily. Specifically, as shown in FIG. 1, the energy absorbing member 11 is disposed over the entire region.

  Next, the operation of the energy absorbing member 11 will be described.

  When an impact load acts on the bumper skin 103 from the front of the automobile 100, the impact load is transmitted to the energy absorbing member 11 through the bumper reinforcing member 104. Then, since the energy absorbing member 11 is set to have a buckling load smaller than that of the side member 102, the energy absorbing member 11 can buckle in the direction of the virtual shaft 17 and suppress transmission of the load to the side member 102.

  Here, since the bulging part 13 is provided in the energy absorption member 11, the axial drag at the initial stage of the collision can be reduced. Moreover, since the outer peripheral part of the bulging part 13 becomes a reference position at the time of buckling, the size and arrangement position of the bulging part 13 are adjusted unlike the case of the energy absorbing member formed entirely in a flat plate shape. Thus, the degree of energy absorption can be adjusted without depending only on the wall length, plate thickness, and material of the energy absorbing member 11.

  Further, since the bulging portion 13 is provided on substantially the entire surface of the energy absorbing member 11, high energy absorption efficiency can be obtained on the entire surface of the energy absorbing member 11. Therefore, it is possible to prevent the virtual shaft 17 from being bent when the energy absorbing member 11 is buckled. And when an impact is applied to the energy absorbing member 11, the energy absorbing member 11 is restrained from being bent, and is buckled evenly in the axial direction of the virtual axis 17 before buckling to obtain high energy absorption efficiency. Can do.

  Further, the bulging portion 13 is such that the bulging portion 13 of the energy absorbing member 11 protrudes toward the inside of the cylinder. Therefore, when the energy absorbing member 11 is buckled, an interference reaction force effect occurs between the adjacent bulging portions 13 and 13. This interference reaction force effect has an effect of absorbing an impact. Thereby, this energy absorption member 11 can absorb an impact with high energy absorption efficiency.

  Here, the experimental result of the energy absorption state of this energy absorption member 11 is shown in FIG.5 and FIG.6. In the figure, reference numeral 110 indicates that one end of the energy absorbing member 11 of the first embodiment is attached to a fixed member, and a 500 kg rigid body is freely dropped from a height of 3 m from the other end side at an initial speed of 27.6 km / h. A change in reaction force and a change in absorbed energy when the shaft is crushed are shown. The energy absorbing member 11 of the first embodiment used in the experiment is formed of a steel material of SPC440W / 1.0t (YP: 355 MPa, TS: 483 MPa, El: 33%). The energy absorbing member 11 has a diameter of 105 mm.

  5 and 6 further show experimental results of the energy absorption state of the energy absorbing member as a comparative example.

  Reference numeral 120 is an experimental result of an energy absorbing member (not shown) as a first comparative example. The material, shape, and diameter of the energy absorbing member are the same as those of the energy absorbing member 11 of the first embodiment, except that the energy absorbing member is formed of a flat plate without the bulging portion 13.

  Reference numeral 130 is an experimental result of an energy absorbing member (not shown) as a second comparative example. The material, shape, diameter, and size and arrangement of the bulging portion of the energy absorbing member are the same as those of the energy absorbing member 11 of the first embodiment, but the bulging portion is formed so as to protrude outward in the cylindrical shape. The difference was made.

  Reference numeral 140 is an experimental result of an energy absorbing member (not shown) as a third comparative example. The material of the energy absorbing member, the shape, the size and arrangement of the bulging part, and the point that the bulging part is formed to protrude outward in the cylindrical shape are the same as the energy absorbing member 11 of the second comparative example. However, it differs from the second comparative example in that the diameter is 100 mm.

  The experiment contents for the first to third comparative examples are the same as the experiment contents for the energy absorbing member 11 of the first embodiment.

  As shown in FIG. 5, the value of the initial drag peak (position indicated by reference numeral 111) when the energy absorbing member 11 of the first embodiment buckles is the peak of the initial drag (reference numeral 131 in the second comparative example). It is about 80 f / kN similar to the position shown. It can be seen that this is lower than about 130 f / kN of the initial drag peak (position indicated by reference numeral 121) of the first comparative example.

  On the other hand, in FIG. 6, the total energy absorption amount of each energy absorbing member is equal to the area of the portion sandwiched between each graph and the horizontal axis. As shown in FIG. 6, the total absorbed energy of the energy absorbing member 11 of the first embodiment is substantially equal to the total absorbed energy of the first comparative example and the third comparative example. It can also be seen that this is higher than the total absorbed energy of the second comparative example.

  As shown in FIGS. 5 and 6, the energy absorbing member 11 according to the first embodiment has substantially the same impact energy absorption as that of the first comparative example formed by a flat plate having no bulging portion. This shows that the amount is maintained, but the larger feature is that the peak value of the initial load is remarkably lowered and a stable load is maintained over the entire stroke thereafter.

  On the other hand, as shown in FIGS. 5 and 6, the energy absorbing member of the second comparative example has a low peak value of the initial load, and the energy absorbing member of the first embodiment in terms of a stable load in the subsequent stroke. 11 shows a tendency similar to FIG. However, it can be seen that the energy absorbing member of the second comparative example is clearly degraded in the total amount of absorbed energy compared to the energy absorbing member 11 of the first embodiment in which the bulging portion protrudes inward. And by contrast with a 2nd comparative example and a 3rd comparative example, in order to obtain the energy absorption total amount similar to a 1st comparative example by the structure which a bulging part protrudes on the cylindrical outer side, an energy absorption member It can be seen that the diameter of the substrate must be different from that of the first comparative example.

  From this experimental result, the energy absorbing member 11 of the first embodiment has an initial load when the plate-like member buckles because the bulging portion 13 protrudes toward the inside of the cylinder. It can be seen that, while suppressing the peak value, the impact can be absorbed with high energy absorption efficiency equivalent to that of the flat plate due to the interference reaction force effect between the adjacent bulging portions 13 and 13.

  As described above, in the first embodiment, the peak value of the initial load is suppressed, the obstacle value applied to the occupant is reduced, the energy is small, the energy absorption efficiency is high, and the degree of energy absorption can be freely adjusted. The absorbing member 11 can be formed.

<Embodiment 2 of the Invention>
8 to 11 show a second embodiment of the present invention.

  The energy absorbing member 21 according to the second embodiment of the present invention is also used for absorbing the impact of the bumper of the automobile 100 shown in FIG. This energy absorbing member 21 is different from the bulging portion 13 of the energy absorbing member 11 of the first embodiment in the shape of the bulging portion 22.

  Specifically, as shown in FIG. 8, the bulging portion 22 of the second embodiment is formed over substantially the entire surface of the energy absorbing member 21 by pressing or the like. The bulging portion 22 bulges inward from the virtual outer surface 28 indicated by a two-dot chain line in the drawings of the energy absorbing member 21 in FIGS. 10 and 11.

  As shown in FIG. 9, each bulging part 22 is a substantially rectangular shape having the same outer shape. As shown in FIG. 9, the bulging portions 22 are arranged so that the respective diagonal lines are along the axial direction and the circumferential direction of the energy absorbing member 21. As shown in FIGS. 10 and 11, the bulging portion 22 bulges from the outer peripheral line 23 to the inside of the energy absorbing member 21, and the size of the bulging is the same. A first ridge line 24 is provided on a diagonal line of the bulging portion 22 along the circumferential direction of the energy absorbing member 21 (that is, the vertical direction in FIG. 9). A trough line 26 is provided on the bulging portion 22 on a diagonal line along the axial direction of the energy absorbing member 21 (that is, in the left-right direction in FIG. 9).

  A pair of second ridge lines 25 and 25 are provided on both sides of the valley line 26. As shown in FIG. 9, the second ridge line has a rhombus shape in front view. One end of the first ridge line 24 is joined to the approximate center of the second ridge line 25. Further, both end portions of the second ridge lines 25 and 25 and both end portions of the valley line 26 are separated from the outer peripheral line 23.

  The first ridge line 24 and the second ridge line 25 are ridge lines when viewed from the inside of the energy absorbing member 21, but are valley lines when viewed from the outside. The valley line 26 is a valley line when viewed from the inside of the energy absorbing member 21, but becomes a ridge line when viewed from the outside.

  Further, the distance L1 between the valley line 26 and the virtual axis 17 of the energy absorbing member 21 shown in FIG. 10 is formed to be longer than the distance L2 between the outer peripheral line 23 and the virtual axis 17.

  Other configurations are the same as those of the first embodiment.

  The energy absorbing member 21 of the second embodiment is capable of absorbing an impact with high energy absorption efficiency when the plate-like member is buckled due to the provision of the bulged portion 22 having a substantially rectangular outer shape. Further, the bulging portion 22 has an outer shape that is rectangular in front view, a first ridge line 24 is formed along one diagonal line, and a valley line 26 is formed along the other diagonal line. The resistance against an impact applied from the outside toward each diagonal direction of the energy absorbing member can be increased.

  Specifically, the outer peripheral line 23 and the first ridge line 24 of the bulging portion 22 serve as reference positions for buckling, and the function as a “tension” in which the valley line 26 exerts a drag in the buckling direction. Fulfill. Therefore, the energy absorbing member 21 can be adjusted without depending on the wall length, plate thickness, and material alone, and the strength of the energy absorbing member 21 can be increased. Thereby, in this Embodiment 2, the energy absorption member 21 which is small, has high energy absorption efficiency, and can freely adjust the degree of energy absorption can be formed.

  In the second embodiment, both end portions of the second ridge lines 25 and 25 and both end portions of the valley line 26 are formed apart from the outer peripheral line 23. However, both end portions of the second ridge lines 25 and 25 and You may form so that the both ends of the valley line 26 may join to the outer periphery line 23. FIG.

  In the second embodiment, the ridge line (first ridge line 24) is on the diagonal line along the circumferential direction of the energy absorbing member 21, and the diagonal line along the axial direction of the energy absorbing member 21 is on the bulging portion 22. Although the valley line 26 is provided, conversely, a valley line may be provided on the diagonal line along the circumferential direction of the energy absorbing member 21 of the bulging portion 22 and a ridge line may be provided on the diagonal line along the axial direction. Moreover, you may provide a trough line or a ridgeline in both the circumferential direction of the energy absorption member 21 of the bulging part 22, and the diagonal line along an axial direction.

<Third Embodiment of the Invention>
The energy absorbing member (not shown) according to the third embodiment of the present invention is also used for shock absorption of the bumper of automobile 100 shown in FIG. This energy absorbing member (not shown) is different from the bulging portions 13 and 22 of the energy absorbing members 11 and 21 of the first and second embodiments in the shape of the bulging portion (not shown). Specifically, the bulging portion (not shown) of the third embodiment is formed in a circular shape in plan view. The rest is the same as in the first and second embodiments. Thereby, the resistance with respect to the impact added from the multi direction outside an energy absorption member (not shown) can be made high. In addition, the shape of the bulging part may be an elliptical shape in plan view.

  In each of the above embodiments, the bulging portions are adjacent to each other, but the bulging portions are close to each other, and a gap is formed between the bulging portions (that is, the bulging portions). The configuration in which the original flat surface of the plate-like member remains between the portions may be employed.

  In each of the above embodiments, the energy absorbing members 11 and 21 are provided between the side member 102 and the bumper reinforcing member 104 of the automobile 100. However, these energy absorbing members 11 and 21 are provided at other parts of the vehicle body. It can also be provided. Moreover, the energy absorption members 11 and 21 can also be applied to things other than automobiles.

  It is needless to say that each of the above embodiments is an exemplification of the present invention and does not mean that the present invention is limited to each of the above embodiments.

11, 21 ... energy absorbing members 13, 22 ... bulging portion 24 ... ridge line (first ridge line)
26 ... Valley line 102 ... Side member (body strength member)
104 ... Bumper reinforcement

Claims (6)

An energy absorbing member that is formed in a cylindrical shape and absorbs energy applied in the cylindrical axial direction by buckling,
An energy absorbing member, wherein a plurality of bulging portions are formed adjacent to or close to a plate-like member, and the bulging portions protrude toward the inside of the cylindrical shape.   2. The energy absorbing member according to claim 1, wherein each of the bulging portions is formed in a polygon in a front view having the same outer shape.   The energy absorbing member according to claim 2, wherein the bulging portion has an outer shape that is substantially circular when viewed from the front.   The outer shape of the bulging portion is formed in a rectangular shape in front view, a ridge line is formed along one diagonal line, and a valley line is formed along another diagonal line. Energy absorbing member.   The energy absorbing member according to any one of claims 1 to 3, wherein the bulging portion is formed adjacent to the energy absorbing member over substantially the entire surface without a gap.   6. The energy absorbing member according to claim 1, wherein the energy absorbing member is disposed between a vehicle body strength member of an automobile and a bumper reinforcing member along a vehicle width direction.