JP2017048804A - Energy absorbing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel and improved energy absorbing structure capable of suppressing a decline in the energy absorption amount of an energy absorbing member when collapsed.SOLUTION: The energy absorbing structure includes a cylindrical fiber reinforced resin energy absorbing member to be collapsed in the axial direction in input of a collision load, to absorb collision energy, and a cylindrical cover member covering an area on the outer peripheral face of the energy absorbing member and adapted to be collapsed in the axial direction by the collision load when input. In the peripheral face of the cover member, a plurality of openings are provided which overlap one another at least in part to communicate the inside of the cover member with the outside in the state that the cover member is collapsed by the collision load.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an energy absorbing structure.

  The vehicle is provided with an energy absorbing member that is crushed when a collision occurs and absorbs the collision energy. A typical example of the energy absorbing member is a crush box disposed between the front bumper beam and the front frame. Conventionally, an energy absorbing member made of a metal material such as a steel plate has been used. In recent years, a fiber reinforced resin (FRP) tube in which reinforcing fibers such as carbon fibers are mixed to reduce the weight of the vehicle body. Shaped energy absorbing members have been put into practical use.

  The fiber-reinforced resin energy absorbing member is compressed in the axial direction by being compressed when a collision load is input. For example, when a collision load is input, local breakage occurs from the front end side of the energy absorbing member, and the breakage progresses sequentially so that the range in which the breakage occurs extends to the rear end side. Here, in the progress of the sequential destruction, the destroyed part of the energy absorbing member (hereinafter also referred to as “crushed residue”) can accumulate in the vicinity of the energy absorbing member. Since crushing debris accumulates in the vicinity of the energy absorbing member, the compression deformation in the axial direction of the energy absorbing member can be partially inhibited, so that the amount of crushing stroke of the energy absorbing member can be smaller than expected. In that case, since the remaining crushing of the energy absorbing member increases, the energy absorption amount in the crushing of the energy absorbing member becomes smaller than expected. In view of this, a technique has been proposed for suppressing a reduction in the amount of crushing stroke caused by crushing residue accumulated in the vicinity of the energy absorbing member.

  For example, in Patent Document 1, in order to increase the amount of crushing stroke of an energy absorbing member, a base member and energy bonded to the end of the cylindrical energy absorbing member made of fiber reinforced resin opposite to the load input side are disclosed. A technique is disclosed in which a discharge portion for discharging the crushed residue from the internal space of the energy absorbing member to the outside is provided at the joint portion with the absorbing member.

JP 2012-137129 A

  Here, since the energy absorbing member made of fiber reinforced resin is more easily damaged than the crash box made of steel plate, when using the energy absorbing member made of fiber reinforced resin for a vehicle, it is necessary to consider chipping resistance, weather resistance, etc. There is. Specifically, it is desired to prevent the energy absorbing member from being damaged by pebbles or rainwater splashed by the wheels. As a countermeasure, it is conceivable to cover the outer peripheral surface of the energy absorbing member with a cover member. Such a cover member is crushed in the axial direction when the energy absorbing member is crushed when a collision load is input.

  However, when the outer peripheral surface of the energy absorbing member is covered with the cover member, crushing debris can accumulate in the space between the cover member and the energy absorbing member. And since the compressive deformation in the axial direction of the energy absorbing member can be partially inhibited by the crush accumulated in the space between the cover member and the energy absorbing member, the amount of crushing stroke of the energy absorbing member is assumed rather than Can be less. Thereby, since the remaining crush of the energy absorbing member increases, the energy absorption amount in the crushing of the energy absorbing member becomes smaller than expected.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is a new and improved that can suppress a decrease in the amount of energy absorption in the collapse of the energy absorbing member. It is to provide an energy absorbing structure.

  In order to solve the above-mentioned problem, a cylindrical energy absorbing member made of fiber reinforced resin that absorbs collision energy by collapsing in the axial direction when a collision load is input, and an outer peripheral surface of the energy absorbing member are covered, and the collision load A cylindrical cover member that is crushed in the axial direction at the time of input, and the cover member is at least partially overlapped with each other in a state in which the cover member is crushed by the collision load, An energy absorbing structure is provided in which a plurality of openings are provided to communicate the interior and exterior of the member.

  A plurality of openings of the cover member may overlap each other at least partially by buckling in a bellows shape when the cover member is crushed.

  The cover member has a first tapered portion having a cross-sectional shape that expands from the input side of the collision load toward the side opposite to the input side, and is reduced as it goes from the input side to the side opposite to the input side. The second taper portion having a cross-sectional shape may be alternately provided, and the opening portion of the cover member may be provided in each of the first taper portion and the second taper portion.

  The dimension of the opening provided in each of the first taper and the second taper is such that the bending stiffness of the second taper is provided on the input side with respect to the second taper. You may set so that it may become larger than the bending rigidity of a 1st taper part.

  The cover member is provided with a plurality of the first taper portions, and the dimensions of the openings provided in the plurality of first taper portions are the dimensions of the cover member of the plurality of first taper portions. The first taper portion provided at a position near the input-side end portion may be set such that the bending rigidity becomes smaller.

  The input side end of the cover member may have a substantially cylindrical shape, and an opening of the cover member may be provided on a peripheral surface of the input side end of the cover member.

  A holding member that holds an end of the energy absorbing member opposite to the input side of the collision load, and the holding member has an opening at a position corresponding to the internal space of the energy absorbing member; Also good.

  As described above, according to the present invention, it is possible to suppress a decrease in energy absorption amount due to the collapse of the energy absorbing member.

It is sectional drawing which shows an example of the energy absorption structure which concerns on embodiment of this invention. It is a side view showing an example of a cover member concerning the embodiment. It is a front view showing an example of a cover member concerning the embodiment. It is a schematic diagram which shows the mode of progress of the sequential destruction of the energy absorption structure which concerns on the same embodiment. It is a schematic diagram which shows the mode of progress of the sequential destruction of the energy absorption structure which concerns on the same embodiment.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<1. Energy absorbing structure>
First, with reference to FIG. 1, the energy absorption structure 10 which concerns on this embodiment is demonstrated.

  FIG. 1 is a cross-sectional view showing an example of an energy absorbing structure 10 according to the present embodiment. FIG. 1 is a cross-sectional view showing a state where the energy absorbing structure 10 is attached between a front bumper beam 30 and a front frame 50 of a vehicle. FIG. 1 is a view of the state in which the energy absorbing structure 10 is held as viewed from above the vehicle. In the following description, the front bumper beam 30 side of the energy absorbing structure 10 may be referred to as a front end side, and the front frame 50 side may be referred to as a rear end side.

  The energy absorbing structure 10 includes an energy absorbing member 100, a fixing member 300, a holding member 500, and a cover member 700. The energy absorbing member 100 has a front end side fixed to the fixing member 300 and a rear end side held by a holding member 500. The fixing member 300 is joined to the front bumper beam 30. The holding member 500 is joined to the front end side of the front frame 50. The energy absorbing structure 10 is disposed between the front bumper beam 30 and the front frame 50, and the front end side fixed to the front bumper beam 30 is an input side of a collision load.

(1-1. Energy absorbing member)
The energy absorbing member 100 receives a collision load when the vehicle collides with a preceding vehicle, an obstacle, or another target object, and absorbs collision energy. The energy absorbing member 100 also plays a role of efficiently transmitting the collision load to the front frame 50 when the collision load is large. The energy absorbing member 100 is a cylindrical member formed of fiber reinforced resin. In this embodiment, the energy absorbing member 100 is a multi-layer composite material formed using a carbon fiber reinforced resin (CFRP) using a thermosetting resin and carbon fiber, and has high strength and light weight. Can be realized.

  In the present embodiment, the energy absorbing member 100 has a cylindrical shape. The energy absorbing member 100 made of fiber reinforced resin receives a load (crush load) when a collision load is input, and is crushed while sequentially breaking from the tip side. Since the energy absorbing member 100 made of fiber reinforced resin is buckled or sequentially broken at a small interval as compared with the crash box made of steel plate, it is possible to realize stable impact energy absorption with little load fluctuation. Further, the energy absorbing member 100 made of fiber reinforced resin has the characteristics that the remaining amount of crushing is relatively small and the amount of impact energy absorbed per unit weight is large. The fiber reinforced resin-made energy absorbing member 100 can be, for example, a braid composed of a braided string and a vertical string using a fiber material and a thermoplastic resin.

  The reinforcing fiber used for the fiber reinforced resin constituting the energy absorbing member 100 is not particularly limited. For example, carbon fibers, ceramic fibers such as glass fibers, organic fibers such as aramid fibers, and reinforcing fibers obtained by combining these fibers can be used. Among these, carbon fibers are preferably included from the viewpoint of having high mechanical properties and ease of strength design.

  Further, the matrix resin of the fiber reinforced resin constituting the energy absorbing member 100 may be a thermosetting resin or a thermoplastic resin. In the case of a thermosetting resin, examples of the main material include epoxy resins, unsaturated polyester resins, vinyl ester resins, phenol resins, polyurethane resins, and silicon resins. The thermosetting resin may be one of these or a mixture of two or more. When these thermosetting resins are employed as the matrix resin, an appropriate curing agent or reaction accelerator may be added to the thermosetting resin.

  In the case of a thermoplastic resin, the main materials include, for example, polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride resins, ABS resins, polystyrene resins, AS resins, polyamide resins such as nylon 6 and nylon 66, and polyacetal resins. , Polycarbonate resins, polyethylene terephthalate, polybutylene terephthalate and other thermoplastic polyester resins, PPS (polyphenylene sulfide) resins, fluororesins, polyetherimide resins, polyetherketone resins, polyimide resins, polyethersulfone resins, aromatic polyamide resins Etc. are exemplified.

  The thermoplastic resin may be one of these, or a mixture of two or more. In the case of a mixture, a compatibilizer may be used in combination. Furthermore, brominated flame retardants, silicon-based flame retardants, red phosphorus, and the like may be added as flame retardants. It is preferable to use a thermoplastic resin for automobile parts that are required to be relatively mass-produced from the viewpoint of ease of molding and mass productivity.

  Further, the energy absorbing member 100 having a cylindrical shape is arranged such that the axial direction is along the front-rear direction of the vehicle. The dimensions of the energy absorbing member 100 can be appropriately designed according to the size of the vehicle, the load characteristics to be obtained, the weight of the energy absorbing member 100, and the like. For example, the axial length of the energy absorbing member 100 is 130 to 200 mm, the diameter of the inner space is 40 to 70 mm, and the thickness is 3 mm.

  The energy absorbing member 100 has a reduced diameter portion 102 whose outer periphery is reduced in diameter toward the end portion on the distal end side. When the distal end side of the energy absorbing member 100 is pressed by the reduced diameter portion 102, peeling is likely to occur between a plurality of layers constituting the energy absorbing member 100. Thereby, the trigger of the destruction of the front end side of the energy absorption member 100 is given, and it can be made easy to produce the progress of the sequential destruction from the front end side of the energy absorption member 100 to the rear end side.

(1-2. Fixing member)
The fixing member 300 is a member that is bonded to the front bumper beam 30 and that fixes the front end side of the energy absorbing structure 10. The fixing member 300 is also called, for example, a bumper stay. The fixing member 300 is made of, for example, a metal material typified by a steel plate or the like, aluminum, or the like. When a vehicle collision occurs, the fixing member 300 transmits the impact received by the front bumper beam 30 to the energy absorbing structure 10.

  In the energy absorbing structure 10 shown in FIG. 1, the end portion on the distal end side of the energy absorbing member 100 is fixed to the fixing member 300 with an adhesive or the like. As an adhesive that can be used for joining the energy absorbing member 100 and the fixing member 300, an epoxy resin-based, acrylic resin-based, urethane resin-based adhesive, or the like can be used as appropriate. Note that, when the energy absorbing member 100 is firmly held by the holding member 500, the end portion on the distal end side of the energy absorbing member 100 may not be joined to the fixing member 300.

(1-3. Holding member)
The holding member 500 is attached to the front end side of the front frame 50 and holds the end portion on the rear end side of the energy absorbing member 100. The holding member 500 is a plate-like member made of, for example, a metal material typified by a steel plate or the like, aluminum, or the like. In the energy absorbing structure 10 shown in FIG. 1, the end portion on the rear end side of the energy absorbing member 100 is fixed to the holding member 500 with an adhesive or the like. As an adhesive that can be used for joining the energy absorbing member 100 and the holding member 500, an epoxy resin-based, acrylic resin-based, urethane resin-based adhesive, or the like can be used as appropriate.

  Further, the holding member 500 is provided with an opening 502 at a position corresponding to the internal space of the energy absorbing member 100. The opening 502 is a passage that discharges at least a part of the crush of the energy absorbing member 100 that has been destroyed by the inner winding to the outside of the energy absorbing member 100 when the energy absorbing member 100 is crushed. Therefore, the increase in the remaining crushing of the energy absorbing member 100 due to the destroyed crushing residue accumulated in the internal space of the energy absorbing member 100 is suppressed. Instead of the opening 502, a recess protruding toward the front frame 50 may be provided.

(1-4. Cover member)
The cover member 700 is a cylindrical member that covers the outer peripheral surface of the energy absorbing member 100. The cover member 700 protects the energy absorbing member 100 by preventing foreign objects such as pebbles that are flipped up by the wheels from colliding with the energy absorbing member 100 or attaching rainwater to the energy absorbing member 100. Yes. In this embodiment, the cover member 700 is made of a thin steel plate, but may be made of a light metal plate such as aluminum or a resin.

  Further, the cover member 700 is crushed in the axial direction together with the crush of the energy absorbing member 100 when a collision load is input. In the energy absorbing structure 10 according to the present embodiment, the energy absorbing member 100 mainly bears the collision load, and the cover member 700 bears the collision load. Therefore, regardless of the constituent material of the cover member 700, a relatively stable load characteristic can be obtained when the energy absorbing structure 10 is crushed.

  The end of the cover member 700 on the front end side is joined to the fixing member 300. Further, the end portion on the rear end side of the cover member 700 is joined to the holding member 500. The cover member 700, the fixing member 300, and the holding member 500 can be joined by various methods such as welding or joining with an adhesive. When the front bumper beam 30 is pulled forward, for example, when the vehicle is towed, a tensile force is applied to the energy absorbing structure 10. In the present embodiment, since the cover member 700 is joined to the fixing member 300 and the holding member 500, a part of the pulling force applied to the energy absorbing structure 10 when the vehicle is towed can be received by the cover member 700. Therefore, deformation and breakage of the energy absorbing member 100 when the vehicle is towed can be suppressed.

  A plurality of openings 702 are provided on the peripheral surface of the cover member 700. The plurality of openings 702 at least partially overlap each other in a state where the cover member 700 is crushed by a collision load, and communicates the inside and the outside of the cover member 700. Specifically, the cover member 700 buckles in a bellows shape when collapsed, so that the plurality of openings 702 at least partially overlap each other. In the present embodiment, in the state in which the cover member 700 is crushed, the inside and the outside of the cover member 700 are communicated with each other by a plurality of openings 702 that are at least partially overlapped with each other. At least a part of the 100 crushed debris can be discharged to the outside of the cover member 700 when a collision load is input.

  Thereby, when the energy absorbing member 100 is crushed, it is possible to suppress the crushing of the energy absorbing member 100 that has been destroyed by the outer winding from being accumulated in the space between the cover member 700 and the energy absorbing member 100. Therefore, it is possible to suppress partial inhibition of the axial compression deformation of the energy absorbing member 100 due to crushing accumulated in the space between the cover member 700 and the energy absorbing member 100. Therefore, the fall of the crush stroke amount of the energy absorption member 100 can be suppressed. Thereby, since the increase in the remaining crush of the energy absorbing member 100 is suppressed, it is possible to suppress a decrease in the amount of energy absorption when the energy absorbing member 100 is crushed. The details of the progress of the sequential destruction of the energy absorbing structure 10 when the collision load is input will be described later.

  2 and 3 are a side view and a front view, respectively, showing an example of the cover member 700 according to the present embodiment. As shown in FIG. 2, the end portion 704 on the distal end side of the cover member 700 has a substantially cylindrical shape. The cover member 700 has first tapered portions 706a and 706b having a cross-sectional shape that expands from the front end side toward the rear end side, and a second cross-sectional shape that decreases from the front end side toward the rear end side. Tapered portions 708a and 708b are provided. Hereinafter, when the first tapered portions 706a and 706b are not distinguished from each other, they are also referred to as first tapered portions 706. When the second tapered portions 708a and 708b are not distinguished from each other, they are also referred to as second tapered portions 708.

  The first tapered portion 706 and the second tapered portion 708 are located behind the end portion 704 and are provided alternately. Accordingly, when the load is input, the cover member 700 can buckle so that the first taper portion 706 and the second taper portion 708 that are provided side by side overlap each other, and therefore, the first taper portion 706 and the second taper portion 708. It is possible to at least partially overlap the openings 702 respectively provided in the two. In the present embodiment, for example, as illustrated in FIG. 2, the cover member 700 has an end 704, a first taper 706 a, a second taper 708 a, and a first taper 706 b in order from the front end side. And the 2nd taper part 708b is provided in a row. In the present embodiment, two each of the first taper portion 706 and the second taper portion 708 are provided, but the technical scope of the present invention is not limited to such an example. For example, the first taper portion 706 and the second taper portion 706 One or three or more second tapered portions 708 may be provided.

  An opening 702 is provided in each of the end portion 704, the first tapered portion 706, and the second tapered portion 708. For example, as shown in FIG. 2, the openings 702 are arranged in a row in the axial direction when viewed from the side of the cover member 700. Also, as shown in FIG. 3, a plurality of openings 702 may be provided at intervals in the circumferential direction of the cover member 700. In this embodiment, the opening 702 has a substantially circular shape, but the technical scope of the present invention is not limited to such an example. For example, the opening 702 has a substantially elliptical shape, a substantially rectangular shape, or a combination thereof. You may have the shape of. In addition, the arrangement of the openings 702 is not limited to the example. For example, the number of openings 702 provided in each of the end 704, the first taper 706, and the second taper 708 is illustrated in the drawing. The number may be other than the number, and the interval in the circumferential direction and the axial direction of the cover member 700 of the opening 702 is not limited to the example shown in the drawings.

  The dimensions of the opening 702 provided in each of the first taper portion 706 and the second taper portion 708 are such that the bending rigidity of the second taper portion 708 is provided at the tip side with respect to the second taper portion 708. It is set so as to be larger than the bending rigidity of the first taper portion 706. Here, the smaller the inner diameter of the opening 702 provided in the first taper 706 or the second taper 708, the smaller the inner diameter of the first taper 706 or the second taper in the circumferential cross section passing through the opening 702. Since the sectional moment of inertia of the portion 708 is increased, the bending rigidity is increased. In the present embodiment, for example, the second tapered portion 708a is formed by making the inner diameter of the opening 702 of the second tapered portion 708a (708b) smaller than the inner diameter of the opening 702 of the first tapered portion 706a (706b). The bending rigidity of (708b) is set to be larger than the bending rigidity of the first tapered portion 706a (706b).

  As a result, when the collision load is input, the first taper portion 706 provided on the front end side with respect to the second taper portion 708 is likely to buckle preferentially compared to the second taper portion 708. . Accordingly, the first tapered portion 706 is overlapped with the inner peripheral surface of the second tapered portion 708 provided on the rear end side with respect to the first tapered portion 706. The tapered portion 706 can be buckled. Therefore, the cover member 700 can be buckled in a bellows shape when it is crushed.

  The size of the opening 702 provided in each of the first tapered portions 706 is set so that the bending rigidity of the first tapered portion 706 provided near the end portion 704 of the first tapered portion 706 is smaller. The In the present embodiment, for example, the inner diameter of the opening 702 of the first taper 706a provided closer to the end 704 than the first taper 706b is set to the inner diameter of the opening 702 of the first taper 706b. By making it larger than the inner diameter, the bending stiffness of the first tapered portion 706a is set to be smaller than the bending stiffness of the first tapered portion 706b.

  Accordingly, the first tapered portion 706 provided on the distal end side among the plurality of first tapered portions 706 is likely to buckle preferentially when a collision load is input. Therefore, when the cover member 700 is crushed, it is possible to suppress a part of the first tapered portion 706 from remaining without buckling. Therefore, it becomes easy to buckle the cover member 700 in a bellows shape when crushing.

<2. Crushing action of energy absorbing structure>
So far, the configuration of the energy absorbing structure 10 according to the present embodiment has been described. Next, the progress of sequential destruction of the energy absorbing structure 10 according to the present embodiment will be described. 4 and 5 are schematic views showing the progress of the sequential destruction of the energy absorbing structure 10.

  When a vehicle collision occurs and a collision load is input to the energy absorbing structure 10, the energy absorbing member 100 and the cover member 700 are compressed and begin to collapse in the axial direction. In the initial stage of the crushing, as shown in FIG. 4, the energy absorbing member 100 is broken while the front end side opens to the inner winding and the outer winding.

  The cover member 700 starts to buckle from a portion on the distal end side in a range where the first tapered portion 706 and the second tapered portion 708 are provided. Specifically, the first taper portion 706a of the cover member 700 is buckled at the initial stage of crushing. As shown in FIG. 4, the first taper portion 706 a is formed of the second taper portion 708 a in which the inner peripheral surface of the first taper portion 706 a is provided on the rear end side with respect to the first taper portion 706 a. Buckling to overlap with the inner surface. Further, due to the occurrence of the buckling, the outer peripheral surface of the first taper portion 706 a faces the outer peripheral surface of the end portion 704.

  Therefore, as shown in FIG. 4, the openings 702 respectively provided in the end portion 704, the first tapered portion 706 a, and the second tapered portion 708 a of the cover member 700 at least partially overlap each other. Thereby, the inside and the outside of the cover member 700 are communicated with each other by the opening portions 702 provided in the end portion 704, the first tapered portion 706a, and the second tapered portion 708a. Therefore, the portion on the front end side of the crushed debris 104a of the energy absorbing member 100 that has been destroyed by the outer winding passes through the opening portions 702 provided in the end portion 704, the first tapered portion 706a, and the second tapered portion 708a, respectively. And discharged to the outside of the cover member 700. Note that the end portion 704 is designed to be less likely to buckle than the first tapered portion 706 and the second tapered portion 708, and therefore the first tapered portion 706 is crushed when the cover member 700 is crushed. And the 2nd taper part 708 can buckle preferentially.

  In the present embodiment, the bending stiffness of the second taper portion 708 is set to be larger than the bending stiffness of the first taper portion 706 provided side by side with respect to the second taper portion 708. Thereby, in the crushing of the cover member 700, the first tapered portion 706a is likely to buckle preferentially compared to the second tapered portion 708a, so that the buckling of the first tapered portion 706a is reduced. Realized.

  And destruction progresses sequentially so that the range which destruction in energy absorption member 100 may spread to the back end side. FIG. 5 shows a state in which sequential destruction of the energy absorbing structure 10 has further progressed from the state shown in FIG.

  Since the bending stiffness of the first taper portion 706a of the cover member 700 is designed to be smaller than the bending stiffness of the first taper portion 706b, the first taper portion 706a is the same as the first taper portion 706b. It tends to buckle preferentially in comparison. Therefore, the first taper portion 706b buckles after the first taper portion 706a buckles. As shown in FIG. 5, the first taper portion 706 b is formed of the second taper portion 708 b in which the inner peripheral surface of the first taper portion 706 b is arranged on the rear end side with respect to the first taper portion 706 b. Buckling to overlap with the inner surface. Further, due to the occurrence of the buckling, the outer peripheral surface of the first tapered portion 706b is opposed to the outer peripheral surface of the second tapered portion 708a.

  Therefore, as shown in FIG. 5, the cover member 700 is provided at the end 704, the first taper 706a, the second taper 708a, the first taper 706b, and the second taper 708b, respectively. Openings 702 at least partially overlap each other. Accordingly, the inside and outside of the cover member 700 are formed by the openings 702 provided in the end 704, the first taper 706a, the second taper 708a, the first taper 706b, and the second taper 708b, respectively. And communicated with each other. Therefore, the portion on the distal end side of the crushed debris 104a of the energy absorbing member 100 that is destroyed by the outer winding is the end portion 704, the first taper portion 706a, the second taper portion 708a, the first taper portion 706b, and the second portion. Are discharged to the outside of the cover member 700 through openings 702 respectively provided in the taper portion 708b.

  In the present embodiment, as shown in FIG. 5, the cover member 700 is buckled in a bellows shape, so that a plurality of openings 702 provided in the cover member 700 overlap each other at least partially. Thereby, at least a part of the crushed debris 104a of the energy absorbing member 100 broken by the outer winding can be discharged to the outside of the cover member 700 when a collision load is input.

  In the present embodiment, an opening 502 is provided in the center of the holding member 500 that holds the rear end side of the energy absorbing member 100. As a result, as shown in FIG. 5, the portion on the tip side of the crushed debris 104 b of the energy absorbing member 100 that has been broken into the inner winding is discharged from the inside of the energy absorbing member 100 to the outside through the opening 502. . Therefore, the crushing debris 104b of the energy absorbing member 100 destroyed by the inner winding is less likely to be clogged inside the energy absorbing member 100, and the remaining crushing of the energy absorbing member 100 is reduced. Therefore, it is possible to prevent the crushing stroke amount of the energy absorbing member 100 from decreasing, and to obtain a large energy absorption amount.

<3. Conclusion>
According to the embodiment described above, the energy absorbing structure 10 includes the cylindrical cover member 700 that covers the outer peripheral surface of the energy absorbing member 100 and is crushed in the axial direction when a collision load is input. A plurality of openings 702 are provided on the peripheral surface of the cover member 700. The plurality of openings 702 at least partially overlap each other in a state where the cover member 700 is crushed by a collision load, and communicates the inside and the outside of the cover member 700. Thereby, at least a part of the crush of the energy absorbing member 100 broken by the outer winding can be discharged to the outside of the cover member 700 when the collision load is input.

  Thereby, when the energy absorbing member 100 is crushed, it is possible to suppress the crushing of the energy absorbing member 100 that has been destroyed by the outer winding from being accumulated in the space between the cover member 700 and the energy absorbing member 100. Therefore, it is possible to suppress partial inhibition of the axial compression deformation of the energy absorbing member 100 due to crushing accumulated in the space between the cover member 700 and the energy absorbing member 100. Therefore, the fall of the crush stroke amount of the energy absorption member 100 can be suppressed. Thereby, since the increase in the remaining crush of the energy absorbing member 100 is suppressed, it is possible to suppress a decrease in the amount of energy absorption when the energy absorbing member 100 is crushed.

  Further, according to the above-described embodiment, the cover member 700 includes the first tapered portion 706 having a cross-sectional shape that expands from the front end side toward the rear end side, and a cross-section that decreases from the front end side toward the rear end side. The second tapered portions 708 having a shape are alternately provided. The first tapered portion 706 and the second tapered portion 708 are each provided with an opening 702. Accordingly, when the load is input, the cover member 700 can buckle so that the first taper portion 706 and the second taper portion 708 that are provided side by side overlap each other, and therefore, the first taper portion 706 and the second taper portion 708. It is possible to at least partially overlap the openings 702 respectively provided in the two.

  In addition, according to the above-described embodiment, the dimensions of the opening 702 provided in each of the first taper portion 706 and the second taper portion 708 are such that the bending rigidity of the second taper portion 708 is the second taper portion. It is set to be larger than the bending rigidity of the first taper portion 706 provided on the front end side with respect to 708. As a result, when the collision load is input, the first taper portion 706 provided on the front end side with respect to the second taper portion 708 is likely to buckle preferentially compared to the second taper portion 708. . Accordingly, the first tapered portion 706 is overlapped with the inner peripheral surface of the second tapered portion 708 provided on the rear end side with respect to the first tapered portion 706. The tapered portion 706 can be buckled. Therefore, the cover member 700 can be buckled in a bellows shape when it is crushed.

  Further, according to the above-described embodiment, the size of the opening 702 provided in each of the first tapered portions 706 is the first tapered portion 706 provided in a position near the end portion 704 in the first tapered portion 706. The bending rigidity is set so as to be smaller. Accordingly, the first tapered portion 706 provided on the distal end side among the plurality of first tapered portions 706 is likely to buckle preferentially when a collision load is input. Therefore, when the cover member 700 is crushed, it is possible to suppress a part of the first tapered portion 706 from remaining without buckling. Therefore, it becomes easy to buckle the cover member 700 in a bellows shape when crushing.

  Further, according to the above-described embodiment, the holding member 500 is provided with the opening 502 at a position corresponding to the internal space of the energy absorbing member 100. As a result, at least a part of the crushed residue 104b of the energy absorbing member 100 that has been destroyed by the inner winding can be discharged from the inside of the energy absorbing member 100 to the outside through the opening 502. Therefore, by making the crushing debris 104b of the energy absorbing member 100 destroyed by the inner winding difficult to clog the inside of the energy absorbing member 100, an increase in the remaining crushing of the energy absorbing member 100 is suppressed. Therefore, it is possible to prevent the crushing stroke amount of the energy absorbing member 100 from decreasing, and to obtain a large energy absorption amount.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  In the above description, the example in which the energy absorbing structure is disposed between the front bumper beam and the front frame has been described. However, the energy absorbing structure may be provided at the rear of the vehicle, for example, the rear bumper beam. It is arranged between the rear frame and the rear frame, and can absorb the collision energy by receiving a collision load from the rear of the vehicle.

DESCRIPTION OF SYMBOLS 10 Energy absorption structure 30 Front bumper beam 50 Front frame 100 Energy absorption member 102 Reduced diameter part 300 Fixing member 500 Holding member 502 Opening part 700 Energy absorption member 702 Opening part 704 End part 706a, 706b 1st taper part 708a, 708b 2nd taper part

Claims (7)

A cylindrical energy absorbing member made of fiber reinforced resin that crushes in the axial direction when absorbing a collision load and absorbs collision energy;
A cylindrical cover member that covers the outer peripheral surface of the energy absorbing member and is crushed in the axial direction when the collision load is input;
With
On the peripheral surface of the cover member, in a state where the cover member is crushed by the collision load, there are provided a plurality of openings that at least partially overlap each other and communicate between the inside and the outside of the cover member.
Energy absorbing structure.   The energy absorbing structure according to claim 1, wherein the cover member is buckled in a bellows shape when being crushed, so that a plurality of openings of the cover member overlap each other at least partially. The cover member has a first tapered portion having a cross-sectional shape that expands from the input side of the collision load toward the side opposite to the input side, and is reduced as it goes from the input side to the side opposite to the input side. Second taper portions having a cross-sectional shape to be alternately provided,
The first taper portion and the second taper portion are provided with openings of the cover member, respectively.
The energy absorbing structure according to claim 2.   The dimension of the opening provided in each of the first taper and the second taper is such that the bending stiffness of the second taper is provided on the input side with respect to the second taper. The energy absorbing structure according to claim 3, wherein the energy absorbing structure is set to be larger than a bending rigidity of the first taper portion. The cover member is provided with a plurality of the first tapered portions,
The dimension of the opening provided in each of the plurality of first taper portions is the first taper portion provided at a position near the input side end of the cover member among the plurality of first taper portions. It is set so that the bending stiffness becomes smaller,
The energy absorption structure according to claim 3 or 4. The input side end of the cover member has a substantially cylindrical shape,
An opening of the cover member is provided on the peripheral surface of the input side end of the cover member.
The energy absorption structure according to any one of claims 3 to 5. A holding member that holds an end of the energy absorbing member opposite to the input side of the collision load;
The holding member is provided with an opening at a position corresponding to the internal space of the energy absorbing member.
The energy absorption structure according to any one of claims 1 to 6.

Images