JP2015067006A - Shock absorbing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shock absorbing structure capable of absorbing energy of impact, by holding an energy absorbing member without hindering progressive crushing of the energy absorbing member.SOLUTION: A shock absorbing structure 9 includes: a cylindrical energy absorbing member 5 composed of composite material having multiple layers in a radial direction, for absorbing impact energy applied to an object to be protected; a pressing part 10 spaced apart from the object to be protected, where one end 5a of the energy absorbing member is disposed so as to face the object to be protected; a support part 11 provided at the object to be protected, and disposed at a side of the other end 5b of the energy absorbing member so as to face the pressing part; and sandwiching members 12 for applying the load in a direction where the pressing part and the support part are made near to each other, making the energy absorbing member be sandwiched between the pressing part and the support part, coming into a tense state by tensile force with reaction force of the energy absorbing member, and bending when the pressing part and the support part move in the approaching direction.

Description

  The present invention relates to an impact absorbing structure that absorbs an impact.

  2. Description of the Related Art In recent years, automobiles equipped with energy absorbing members have become widespread in order to absorb impacts in collision accidents and the like. The energy absorbing member is made of, for example, FRP (fiber reinforced plastic) as a material, is formed in a cylindrical shape, and a plurality of layers are laminated in the radial direction. When a large impact is applied to destroy the vehicle body, the energy absorbing member absorbs impact energy by causing interlaminar fracture (peeling) sequentially from one axial end to the other. Yes (progressive crushing).

  Patent Document 1 discloses a guide mechanism for guiding such an energy absorbing member. Specifically, both ends of the energy absorbing member in the axial center direction are sandwiched between the pressing portion and the supporting portion, and one end of four rods is fixed to the pressing portion, and a hole is formed in the supporting portion to insert the rod. The pressing portion is regulated by the rod so as to move in the axial center direction of the energy absorbing member, and when an impact occurs, a load in the axial center direction is easily applied to the energy absorbing member.

JP 7-217690 A

  When providing a guide mechanism as described in Patent Document 1 above, a tensile load is applied to the rod, and the load is applied to the energy absorbing member in a direction in which the pressing portion and the support portion are close to each other, thereby the energy absorbing member. Is retained. That is, the above guide mechanism can be used as a holding mechanism for holding the energy absorbing member. However, in such a holding mechanism, when an impact is generated, if the load is applied to the energy absorbing member while being inclined with respect to the axial direction, the rod may be clogged and deformed in the hole of the support portion.

  Thus, when the rod is deformed, the energy absorption characteristics are affected, and the above-described progressive crushing is less likely to occur. That is, the conventional holding mechanism has been a factor that hinders the progressive crushing of the energy absorbing member.

  Then, this invention aims at providing the impact-absorbing structure which can hold | maintain an energy absorption member, without inhibiting progressive crushing.

  In order to solve the above problems, an impact absorbing structure of the present invention is formed of a composite material having a plurality of layers in a radial direction and having a cylindrical shape, and an energy absorbing member that absorbs impact energy acting on a protection target; A pressing portion provided at a distance from the protection target, and one end of the energy absorbing member disposed opposite to the protection target; a support portion provided at the other end of the energy absorbing member and disposed opposite to the pressing portion; A load is applied in a direction in which the pressing portion and the support portion are brought close to each other, and the energy absorbing member is sandwiched between the pressing portion and the supporting portion, and a tension state is caused by a tension caused by a reaction force of the energy absorbing member. And a holding member that bends when the support portion moves in the proximity direction.

  A trigger part for inducing interlaminar fracture of the energy absorbing member from the pressing part side is further provided, and the surface of the pressing part facing the support part has a diameter larger than the outer diameter of the energy absorbing member and protrudes toward the supporting part side. A cylindrical guide portion may be provided.

  The energy absorbing member includes a small-diameter portion provided on the pressing portion side, a large-diameter portion that is continuous on the support portion side of the small-diameter portion, and has a larger cross-sectional area formed by a plane perpendicular to the axial direction than the small-diameter portion; The small diameter portion may function as a trigger portion.

  The small-diameter portion that functions as the trigger portion may be a tapered portion whose cross-sectional area gradually decreases from the large-diameter portion side toward the pressing portion side.

  According to the present invention, the energy absorbing member can be held without hindering progressive crushing.

It is a top view of a motor vehicle. It is an external view of an energy absorption member. It is explanatory drawing for demonstrating the aspect of energy absorption in the shock absorption structure of a comparative example. It is explanatory drawing for demonstrating the aspect of energy absorption in the shock absorption structure of this embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a top view of an automobile 1, and a front part located on the left side in FIG. 1 of a vehicle body 2 of the automobile 1 is shown with a simplified internal frame structure. As shown in FIG. 1, the automobile 1 includes two side frames 3 extending in the front-rear direction of the vehicle main body 2 at the front portion of the vehicle main body 2 (protection target). The side frame 3 has a rear end connected to a frame on the rear side (not shown) and a front end connected to the radiator panel 4.

  An energy absorbing member 5 is attached to the front end of each side frame 3, and a bumper beam 6 extending in the vehicle width direction is fixed to the leading ends of both energy absorbing members 5. Thus, the bumper beam 6 is attached to the frame (side frame 3) of the vehicle main body 2 via the energy absorbing member 5.

  FIG. 2 is an external view of the energy absorbing member 5. FIG. 2A shows a perspective view of the energy absorbing member 5, and FIG. 2B shows a side view of the energy absorbing member 5.

  As shown in FIG. 2, the energy absorbing member 5 has a small diameter portion 7 and a large diameter portion 8 formed integrally. The small-diameter portion 7 and the large-diameter portion 8 each have a cylindrical shape and are made of a composite material having a plurality of layers in the radial direction. Here, FRP (fiber reinforced plastic), particularly CFRP (carbon fiber reinforced plastic) is used as the composite material.

  The small-diameter portion 7 has a tapered portion 7c in which a cross-sectional area by a plane perpendicular to the axial direction gradually decreases from one end 7a on the large-diameter portion 8 side toward the other end 7b located on the opposite side to the one end 7a. ing. Here, the inner diameter of the small-diameter portion 7 is constant, and the outer diameter of the small-diameter portion 7 gradually decreases from the one end 7a toward the other end 7b.

  The large-diameter portion 8 is provided continuously to one end 7a in the axial direction of the small-diameter portion 7, and is the most of the small-diameter portions 7 from one end 8a on the small-diameter portion 7 side to the other end 8b located on the opposite side to the one end 8a. It has the same cross-sectional area as the one end 7a having a large cross-sectional area.

  By the way, the energy absorbing member 5 is disposed between the side frame 3 and the bumper beam 6, and depending on the holding mechanism of the energy absorbing member, there is a possibility that the energy absorbing member may inhibit energy absorption.

  FIG. 3 is an explanatory diagram for explaining an aspect of energy absorption in the shock absorbing structure S of the comparative example. As shown in FIG. 3A, the shock absorbing structure S is configured by sandwiching the energy absorbing member E between the support portion A and the pressing portion T. The support portion A is fixed to the side frame 3, and the pressing portion T is fixed to the bumper beam 6.

  One end La of a plurality of rods L is fixed to the pressing portion T. Further, the support portion A is provided with an insertion hole Aa through which the other end Lb of the rod L is inserted. In the rod L, the other end Lb is inserted into the insertion hole Aa, and fastening means (not shown) is attached to the protruding portion from the insertion hole Aa. The fastening means is, for example, a nut or the like, and a thread groove that is screwed into the nut is provided at a projecting portion of the rod L from the insertion hole Aa.

  With the fastening means attached to the rod L, a tensile load acts on the rod L in the axial direction of the energy absorbing member E, and a compressive load from the support portion A and the pressing portion T acts on the energy absorbing member E. To do. Thus, the energy absorbing member E is sandwiched between the support portion A and the pressing portion T.

  Then, when an impact load is applied to the energy absorbing member E from the pressing portion T side due to a collision of the automobile 1 or the like, the destruction of the energy absorbing member E proceeds as shown in FIG. At this time, the length of the energy absorbing member E in the axial direction is shortened, and the support portion A and the pressing portion T approach each other accordingly. Further, the rod L is further inserted into the insertion hole Aa.

  However, depending on the magnitude and direction of the impact load, the rod L may be subjected to a load other than the direction perpendicular to the axial direction with respect to the pressing portion T, and the rod L may be bent as shown in FIG. If it does so, the rod L will be caught in the insertion hole Aa, the energy absorption characteristic of the energy absorption member E will be affected, and there is a possibility that progress of progressive crushing may be hindered or lead to unintended load intervention.

  FIG. 4 is an explanatory diagram for explaining an aspect of energy absorption in the shock absorbing structure 9 of the present embodiment. As shown in FIG. 4A, the shock absorbing structure 9 of the present embodiment includes a pressing portion 10, a supporting portion 11, a clamping member 12, and a guide portion 13 in addition to the energy absorbing member 5 described above. Is done.

  The pressing portion 10 is a plate-like member that is fixed to the bumper beam 6 and interposed between the bumper beam 6 and the energy absorbing member 5, and is disposed so that one end 5 a of the energy absorbing member 5 is opposed to the vehicle body 2. Then, an impact load caused by a collision of the automobile 1 is transmitted to the energy absorbing member 5.

  The support portion 11 is a plate-like member interposed between the side frame 3 and the energy absorbing member 5, and is disposed on the other end 5 b side of the energy absorbing member 5 so as to face the pressing portion 10. And is supported by the vehicle body 2.

  The sandwiching member 12 is made of a material such as a wire or a chain that develops tension when tensioned and does not develop resistance when compressed. The clamping member 12 has one end 12 a fixed to the pressing portion 10. Further, the support portion 11 is formed with a plurality of through holes 11 a that penetrate the support portion 11 in the axial direction of the energy absorbing member 5, and an insertion hole 3 a that faces the through hole 11 a is formed on the front surface of the side frame 3. Is formed. And the clamping member 12 is penetrated by this through-hole 11a and the penetration hole 3a.

  The clamping member 12 is a fixing member in which a portion of the clamping member 12 that is drawn to the opposite side of the pressing portion 10 from the through hole 11a and the insertion hole 3a does not pass through the insertion hole 3a in a state where a predetermined tension is applied. Fixed by. In addition, for example, a portion of the clamping member 12 that is drawn to the opposite side of the pressing portion 10 from the insertion hole 3a may be wound around the side frame 3 itself. In any case, a predetermined tension is applied to the sandwiching member 12, and a compressive load acts on the energy absorbing member 5 from the support portion 11 and the pressing portion 10 by the sandwiching member 12.

  Further, the energy absorbing member 5 may be directly fixed to the bumper beam 6 and the side frame 3 without using the pressing portion 10 and the support portion 11. In this case, the bumper beam 6 functions as the pressing portion 10, and the side frame 3 functions as the support portion 11.

  The holding member 12 applies a load in a direction in which the pressing portion 10 and the support portion 11 are brought close to each other, holds the energy absorbing member 5 between the pressing portion 10 and the supporting portion 11, and reacts with the energy absorbing member 5. Tension is caused by the accompanying tension.

  In addition, a cylindrical guide portion 13 that is larger than the outer diameter of the small diameter portion 7 and the large diameter portion 8 and protrudes toward the support portion 11 is provided on the surface of the pressing portion 10 that faces the support portion 11. ing.

  Then, when an impact load is applied to the energy absorbing member 5 from the pressing portion 10 side due to a collision of the automobile 1 or the like, the destruction of the energy absorbing member 5 proceeds as shown in FIG. Specifically, the small-diameter portion 7 is deformed so as to swell inward in the radial direction of the small-diameter portion 7 from the pressing portion 10 side of the small-diameter portion 7 toward the support portion 11 side.

  And as shown in FIG.4 (c), when destruction of the small diameter part 7 further progresses toward the support part 11 side from the press part 10 side, the layer of the radial outside of the small diameter part 7, and the layer of radial inside And the radially outer layer of the small-diameter portion 7 swells outward in the radial direction of the small-diameter portion 7, and the radially inner layer of the small-diameter portion 7 also swells radially inward of the small-diameter portion 7 (interlayer Destruction).

  Thus, the taper part 7c (small diameter part 7) functions as a trigger part which induces interlaminar fracture. Since the energy absorbing member 5 has the taper portion 7c arranged on the pressing portion 10 side, the energy absorbing member 5 undergoes interlayer breakdown from the pressing portion 10 side toward the support portion 11 side.

  When the pressing portion 10 is pressed toward the support portion 11 by an impact, the length of the energy absorbing member 5 in the axial direction is shortened, and the pressing portion 10 and the support portion 11 are moved in the proximity direction accordingly. Then, as shown in FIGS. 4B and 4C, the clamping member 12 is bent in a relaxed state without acting on tension. Therefore, the influence exerted on the energy absorption characteristics by the sandwiching member 12 is smaller than that of the comparative example, and the interlaminar fracture of the large diameter portion 8 progresses as shown in FIG. Energy is absorbed (progressive crushing).

  Thus, the shock absorbing structure 9 can hold the energy absorbing member 5 without impeding the progressive crushing of the energy absorbing member 5 and absorb the energy of the shock.

  Further, when the interlaminar fracture progresses, the radially outer layer of the small diameter portion 7 rolls up radially outward of the small diameter portion 7 and contacts the guide portion 13. Then, as shown in FIG. 4 (d), the rolled-up portion is wound into the radially inner side of the energy absorbing member 5 with respect to the guide portion 13 while being guided by the guide portion 13.

  As a result, the movement of the energy absorbing member 5 in the radial direction is restricted by the guide portion 13 and the portion wound inside the guide portion 13, and the energy absorbing member 5 is hardly displaced in the radial direction. Therefore, it is possible to avoid a situation in which the position of the energy absorbing member 5 is shifted and a load inclined with respect to the axial direction acts on the energy absorbing member 5.

  In the embodiment described above, the case where the small diameter portion 7 has the tapered portion 7c has been described, but the tapered portion 7c is not an essential configuration. Moreover, the other structure which functions as a trigger part which induces an interlaminar fracture | rupture from the at least press part 10 side of the energy absorption member 5 may be provided instead of the taper part 7c.

  Moreover, although embodiment mentioned above demonstrated the case where the guide part 13 was provided, the guide part 13 is not an essential structure.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments, and various modifications within the scope described in the claims. Needless to say, the modified examples also belong to the technical scope of the present invention.

  The present invention can be used for an impact absorbing structure that absorbs an impact.

2 Vehicle body (protected)
5 Energy absorbing member 5a One end 5b The other end 7 Small diameter portion 7c Tapered portion 8 Large diameter portion 9 Shock absorbing structure 10 Pressing portion 11 Supporting portion 12 Holding member 13 Guide portion

Claims (4)

An energy absorbing member that is formed of a composite material that has a cylindrical shape and a plurality of layers in the radial direction, and that absorbs impact energy acting on a protection target;
A pressing portion that is provided apart from the object to be protected and in which one end of the energy absorbing member is disposed oppositely;
A support portion provided on the object to be protected, and disposed on the other end side of the energy absorbing member so as to face the pressing portion;
A load is applied in a direction in which the pressing portion and the support portion are brought close to each other, and the energy absorbing member is sandwiched between the pressing portion and the supporting portion, and tension is generated by a tension caused by a reaction force of the energy absorbing member. A clamping member that is bent when the pressing portion and the support portion move in the proximity direction,
A shock absorbing structure characterized by comprising: A trigger portion for inducing interlaminar fracture of the energy absorbing member from the pressing portion side;
The surface of the pressing portion that faces the support portion is provided with a cylindrical guide portion that is larger than the outer diameter of the energy absorbing member and protrudes toward the support portion. The shock absorbing structure according to claim 1. The energy absorbing member is
A small diameter portion provided on the pressing portion side;
A large-diameter portion that is continuous to the support portion side of the small-diameter portion, and has a larger cross-sectional area formed by a plane perpendicular to the axial direction than the small-diameter portion;
With
The shock absorbing structure according to claim 2, wherein the small-diameter portion functions as the trigger portion.   The shock absorbing structure according to claim 3, wherein the small-diameter portion that functions as the trigger portion is a tapered portion in which the cross-sectional area gradually decreases from the large-diameter portion side toward the pressing portion side.

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