JP2008221863A - Shock absorbing structure of vehicle frame for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide shock absorbing structure of a vehicle frame for vehicle capable of preventing reduction of amount of shock energy absorption due to breaking, buckling, and deformation in a plane part in a shock absorbing member and achieving high total amount of shock energy absorption. <P>SOLUTION: This shock absorbing structure of the vehicle frame for vehicle is provided with the shock absorbing member 11 like a square cylinder extended in the forward and backward directions of the vehicle frame for vehicle. This shock absorbing structure is provided with a plurality of projecting beads 13 provided across an interval in the longitudinal direction of the shock absorbing member 11 in an external face part 12a of the shock absorbing member 11 and formed in the direction crossing the longitudinal direction of the shock absorbing member 11 orthogonally to allow the shock absorbing member 11 to be deformed by buckling and protruding supporting members 14 arranged in the direction crossing the longitudinal direction of the shock absorbing member 11 in an internal face part 12b of the shock absorbing member 11 between a plurality of these beads 13 orthogonally and having one end fixed to the internal face part 12b of the shock absorbing member 11 and the other end across an interval from the internal face part 12b facing the other end to limit amount of buckling deformation of the shock absorbing member 11 caused by using the beads 13 as basic points. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an impact absorbing structure for a vehicle frame for absorbing impact energy generated during a vehicle collision or the like.

  There is a type in which an impact absorbing member called a crash box is provided at the front end of a vehicle frame such as a truck for the purpose of absorbing impact energy generated when the vehicle collides. This impact absorbing member absorbs impact energy by buckling deformation and crushing at the time of a vehicle collision or the like, thereby reducing damage to the occupant.

  Further, in order to stably buckle and deform the shock absorbing member at the time of a vehicle collision or the like, for example, as in Patent Document 1, the direction in which the shock load acts on the outer surface portion of the shock absorbing member (that is, the shock absorbing member) A bead (buckling deformation bead) is formed in a direction perpendicular to the longitudinal direction), and the buckling deformation of the impact absorbing member is induced by the buckling deformation bead, thereby reducing the initial peak load. Widely known.

Japanese Patent Laid-Open No. 3-94137

  However, in the shock absorbing member formed with the buckling deformation bead as described above, a relatively high shock energy absorption amount is maintained at the beginning of the buckling deformation, but the buckling deformation progresses and the buckling deformation bead is When the bending buckling deformation starts at the flat portion that is not provided, the impact energy absorption amount is drastically reduced. The buckling deformation of the entire shock absorbing member progresses by repeating the buckling deformation at the bead and the bent buckling deformation at the flat surface part. Since the impact energy absorption amount decreases due to the bending buckling deformation, the total impact energy absorption amount becomes low.

  Therefore, an object of the present invention is to provide a shock absorbing structure for a vehicle frame that can suppress a decrease in impact energy absorption amount due to bending buckling deformation at a flat surface portion of the impact absorbing member and has a high total impact energy absorption amount. It is to provide.

  In order to achieve the above object, the present invention provides a shock absorbing structure for a vehicle frame including a rectangular tube-shaped shock absorbing member extending in the front-rear direction of the vehicle frame, and is provided on an outer surface portion of the shock absorbing member. A plurality of convex beads provided in the longitudinal direction of the shock absorbing member at intervals, formed in a direction perpendicular to the longitudinal direction of the shock absorbing member, and for buckling deformation of the shock absorbing member, and the plurality thereof Between the beads, the inner surface of the shock absorbing member is disposed in a direction perpendicular to the longitudinal direction of the shock absorbing member, and one end is fixed to the inner surface of the shock absorbing member and the other end is spaced from the facing inner surface. And a projecting support member for limiting the amount of buckling deformation of the shock absorbing member that occurs from the bead as a base point.

  Here, the other end of the projecting member is formed on the inner surface of the impact absorbing member so that the other end of the projecting member is opposed to the other end. A guide member for guiding in a direction orthogonal to the longitudinal direction of the shock absorbing member may be provided.

  Further, a plate-like member formed so as to face the inner surface of the shock absorbing member may be attached to the other end of the projecting support member.

  A plurality of the support members may be provided at intervals in the longitudinal direction of the shock absorbing member.

  The shock absorbing member may be formed by joining a pair of groove-shaped members facing each other.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of the impact energy absorption amount accompanying the bending buckling deformation in the plane part in an impact-absorbing member can be suppressed, and the impact absorption structure of the vehicle frame for vehicles with a high total impact energy absorption amount is provided. It exhibits an excellent effect of being able to.

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

  FIG. 1 is a perspective view of an impact absorbing structure according to an embodiment of the present invention. 2A is a cross-sectional view of the shock absorbing member according to the embodiment of FIG. 1, and FIG. 2B is a view taken along the line 11b-11b in FIG. 2A.

  Although not shown in the drawings, in this embodiment, the vehicle frame is disposed at a predetermined interval in the vehicle width direction, and is provided across a pair of side members extending in the front-rear direction and the side members. And a cross member extending in the direction.

  As shown in FIG.1 and FIG.2, the impact-absorbing structure 10 which concerns on this embodiment is provided with the impact-absorbing member 11 provided in the front-end part of the side member of the vehicle frame. The impact absorbing member 11 receives impact load at the time of a vehicle collision or the like, and absorbs impact energy by buckling deformation and being crushed by the impact load. In the present embodiment, the shock absorbing member 11 is provided integrally with the side member.

  The shock absorbing member 11 is formed in a rectangular tube shape that extends in the front-rear direction of the vehicle casing 1. Specifically, the shock absorbing member 11 is formed in a substantially rectangular shape (substantially rectangular shape) in which the width of the side surface (height of the shock absorbing member 11) is larger than the width of the upper and lower surfaces (width of the shock absorbing member 11). Yes.

  The outer surface 12a of the shock absorbing member 11 is buckled and deformed at a predetermined interval in the longitudinal direction of the shock absorbing member 11 (the longitudinal direction of the vehicle frame) (the seat of the shock absorbing member 11). A plurality of convex beads (buckling deformation beads) 13 for inducing bending deformation are provided. The beads 13 are formed in a direction perpendicular to the longitudinal direction of the shock absorbing member 11 (up and down direction of the vehicle frame).

  In the present embodiment, the bead 13 is provided on the outer surface portion 12 a that forms the side surface of the shock absorbing member 11.

  Moreover, in this embodiment, the bead 13 is formed in the cross-sectional substantially triangular shape (refer Fig.2 (a)).

  The predetermined interval between the plurality of beads 13 is determined so as to obtain a desired impact energy absorption amount according to the cross-sectional shape, thickness, material, etc. of the vehicle frame.

  By making the bead 13 for buckling deformation of the shock absorbing member 11 convex, if the buckling deformation at the bead 13 progresses to some extent at the time of a vehicle collision or the like, then the flat surface portion 12c where the bead 13 is not provided. However, the flat surface portion 12c is deformed so as to be bent inward due to the buckling deformation of the convex bead 13 (see FIG. 3).

  On the inner surface portion 12 b between the plurality of beads 13 in the shock absorbing member 11, a projecting support member 14 disposed in a direction perpendicular to the longitudinal direction of the shock absorbing member 11 and perpendicular to the beads 13 is provided. The projecting support member 14 is for limiting the amount of buckling deformation of the shock absorbing member 11 that occurs with the bead 13 as a base point.

  Plural support members 14 are provided at predetermined intervals in the longitudinal direction of the shock absorbing member 11. The projecting support member 14 is provided substantially at the center in the vertical direction of the inner surface portion 12 b of the shock absorbing member 11. Further, the projecting support member 14 is provided at the substantially center in the front-rear direction on the inner surface portion 12 b between the beads 13.

  One end of the projecting support member 14 is fixed to the inner surface portion 12b of the shock absorbing member 11 by welding, rivets, bolts, nuts, or the like, and the other end is not fixed to or contacted with the inner surface portion 12b of the facing surface. A gap (C) (for example, 5 to 10 mm) is separated. For this reason, the projecting member 14 is shorter than the inner width dimension of the shock absorbing member 11 so that the other end does not come into contact with the inner surface portion 12b facing each other.

  In the present embodiment, the projecting support member 14 is provided on the inner surface portion 12 b that forms the side surface of the shock absorbing member 11.

  In the present embodiment, the projecting member 14 is a circular pipe (pipe) (for example, 16 mm in diameter). However, the projecting member 14 may be formed of an L-shaped member (angle material) or a groove-shaped member (channel material).

  The predetermined interval between the plurality of projecting members 14 is determined so as to obtain a desired impact energy absorption amount according to the displacement state due to buckling deformation in the flat surface portion 12 c of the impact absorbing member 11.

  In the present embodiment, the shock absorbing member 11 includes a groove member (channel material) 15 and a groove member 16 to which the projecting support member 14 is fixed, facing each other, and the flanges of the pair of groove members 15 and 16. The parts are joined by welding, rivets or bolts / nuts.

  Next, the operation of this embodiment will be described.

  At the time of a vehicle collision or the like, an impact load L (see FIG. 1) acts on the impact absorbing member 11 from the front to the rear in the front-rear direction of the vehicle frame via a bumper (not shown) or the like. When the impact load L exceeds the elastic deformation region of the impact absorbing member 11, the impact absorbing member 11 begins to buckle (plastically deform), but the bead 13 formed in the direction perpendicular to the longitudinal direction of the impact absorbing member 11 is impacted. In order to induce buckling deformation of the absorbing member 11, buckling deformation occurs in the portion where the frontmost bead 13 is provided.

  Next, when the buckling deformation at the foremost bead 13 progresses to some extent, the buckling deformation occurs at the flat surface portion 12c behind the bead 13, but since the bead 13 is convex, the flat surface portion 12c. Begins to deform so as to bend inward under the buckling deformation of the bead 13 (see FIG. 3). At this time, the other end of the support member 14 is spaced from the facing inner surface portion 12b and does not hinder the bending buckling deformation of the flat surface portion 12c. Therefore, the initial peak load obtained by providing the bead 13 is reduced. It does not hinder the performance of keeping it low.

  When the flat surface portion 12c is bent inward and bending buckling deformation at the flat surface portion 12c progresses to some extent, the space between the protruding member 14 and the inner surface portion 12b of the opposite surface to which the protruding member 14 is not fixed. The gap C provided on the surface gradually decreases, and the projecting member 14 and the inner surface portion 12b facing each other come into contact with each other. At this time, since the projecting member 14 is sandwiched between the inner surfaces of the shock absorbing member 11 and acts like a projecting bar, the bending buckling deformation at the plane portion 12c is limited, and a large resistance is generated. With this resistance, when the flat surface portion 12c is bent and buckled and deformed in the conventional structure, the cross-sectional area or cross-section coefficient of the shock absorbing member 11 is reduced to reduce the shock energy absorption amount. In this embodiment, the shock absorbing member 11 is reduced. Therefore, the buckling deformation of the shock absorbing member 11 progresses while maintaining a high shock energy absorption amount.

  If the foremost bead 13 and the flat portion 12c in the shock absorbing member 11 are crushed to some extent in this way, then the bead 13 and the flat portion 12c behind the foremost bead 13 in the shock absorbing member 11 are subsequently Sequentially buckled and crushed. At this time, the next projecting support member 14 acts as a resistance against the buckling deformation in the flat surface portion 12c, and limits the deformation amount of the buckling deformation in the flat surface portion 12c. The shock absorbing member 11 as a whole is buckled and crushed sequentially toward the rear starting from the frontmost bead 13.

  The result of having performed simulation about the shock absorption structure 10 which concerns on this embodiment is shown in FIG. In the load-stroke diagram shown in FIG. 4, the vertical axis is the load (impact load), the horizontal axis is the stroke (crush amount), and the area surrounded by the curve and the horizontal axis is the impact energy absorption amount. Equivalent to. Further, in FIG. 4, the solid line indicates the shock absorbing member (this embodiment) provided with the protruding member, and the broken line indicates the shock absorbing member not provided with the protruding member. In the simulation, three beads (buckling deformation beads) are provided at intervals in the longitudinal direction of the impact absorbing member, and protruding members are provided between the beads. As a result of the simulation, in this embodiment, the initial peak load is the same as that of the impact absorbing member not provided with the projecting member, and the impact energy absorption amount within the effective stroke range E is not provided with the projecting member. It turned out that it can maintain high compared with an absorption member.

  In short, according to the present embodiment, since the support member 14 acts as a resistance against the buckling deformation at the flat surface portion 12c, the impact due to the folding buckling deformation at the flat surface portion 12c in the shock absorbing member 11 is achieved. A decrease in the energy absorption amount can be suppressed, and the total impact energy absorption amount can be improved.

  Further, since the one end of the projecting support member 14 is fixed to the inner surface portion 12b of the shock absorbing member 11, and the other end is spaced from the facing inner surface portion 12b, the initial buckling deformation at the flat surface portion 12c is performed. Therefore, the performance of keeping the initial peak load obtained by providing the beads 13 low is not hindered.

  Further, by adding the projecting member 14 to an existing shock absorbing member (crash box) without changing its main body shape, the total shock energy absorption amount of the existing shock absorbing member can be improved. At that time, since it is not necessary to change the shape of the main body of the existing shock absorbing member, there is no influence on the vehicle layout due to the design change.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various other embodiments can be adopted.

  For example, in the above-described embodiment, the bead 13 is formed in a substantially triangular cross section. However, the present invention is not limited to this, and the bead 13 is formed in a substantially trapezoidal cross section as shown in FIG. Alternatively, as shown in FIG. 6, the bead 13 may be formed in a substantially semicircular cross section.

  Further, in the above-described embodiment, the projecting support member 14 is provided at the approximate center in the vertical direction of the inner surface portion 12b of the shock absorbing member 11, and the inner surface portion 12b between the beads 13 is provided at the approximate center in the front-rear direction. However, the invention is not limited to this, and depending on the displacement state due to buckling deformation in the flat surface portion 12c, the projecting support member 14 is defined as the longitudinal direction (front-rear direction) of the shock absorbing member 11 or the longitudinal direction of the shock absorbing member 11. You may arrange | position by shifting on the surface of the inner surface part 12b in the orthogonal direction (up-down direction).

  In the above-described embodiment, one protruding support member 14 is provided on the flat surface portion 12c between the beads 13 of the shock absorbing member 11. However, the present invention is not limited to this, and the flat surface portion 12c of the shock absorbing member 11 is not limited thereto. A plurality of support members 14 may be provided on the flat portion 12c between the beads 13 of the shock absorbing member 11 in accordance with the displacement state due to buckling deformation or the amount of shock energy absorbed. At that time, a plurality of protruding members 14 may be provided in a direction (vertical direction) orthogonal to the longitudinal direction of the shock absorbing member 11.

  Further, the displacement mode at the flat surface portion 12c of the shock absorbing member 11 is unstable, and even if the flat surface portion 12c buckles and deforms to some extent, the projecting member 14 does not apply well to the facing inner surface portion 12b and receives a load. If not, as shown in FIG. 7, the other end of the projecting member 14 is formed on the inner surface 12 b of the impact absorbing member 11 such that the other end of the projecting member 14 is absorbed. A guide member 17 for guiding in a direction orthogonal to the longitudinal direction of the member 11 may be provided. In the illustrated example, the guide member 17 is a circular pipe (pipe), one end of which is fixed to the inner surface portion 12b facing the other end of the support member 14 by welding, rivets or bolts and nuts, and the other end. However, it does not adhere to or contact the outer periphery of the support member 14 and is spaced a predetermined distance apart.

  Further, as shown in FIG. 8, the other end of the projecting support member 14 is formed so as to face the inner surface portion 12b of the shock absorbing member 11, covers the other end of the shock absorbing member 11, and is larger than the other end. A plate-like member 18 having an area may be mounted. The plate-like member 18 is fixed to the other end of the projecting support member 14 by welding, rivets or bolts / nuts.

  7 and 8, even if the displacement mode at the flat surface portion 12c of the shock absorbing member 11 is unstable, if the flat surface portion 12c is buckled and deformed to some extent, the projecting member 14 faces the inner surface of the facing surface. Since the load can be applied to the portion 12b and the load can be received, the amount of buckling deformation of the shock absorbing member 11 can be surely limited by the projecting support member 14.

  In the above-described embodiment, the shock absorbing member 11 is integrally provided on the side member of the vehicle frame. However, the present invention is not limited to this, and the shock absorbing member 11 is the side member of the vehicle frame. It may be formed as a separate body and attached to the side member by welding, rivets or bolts / nuts.

  Further, in the above-described embodiment, the shock absorbing member 11 is provided at the front end portion of the side member of the vehicle frame. However, the present invention is not limited to this, and the shock absorbing member 11 is provided on the side member of the vehicle frame. You may provide in a rear-end part.

FIG. 1 is a perspective view of an impact absorbing structure according to an embodiment of the present invention. 2A is a cross-sectional view of the shock absorbing member according to the embodiment of FIG. 1, and FIG. 2B is a view taken along the line 11b-11b in FIG. 2A. FIG. 3 is a diagram for explaining bending buckling deformation at the flat surface portion of the shock absorbing member. FIG. 4 is a load-stroke diagram. FIG. 5 is a cross-sectional view of a shock absorbing member according to a modification. FIG. 6 is a cross-sectional view of an impact absorbing member according to a modification. FIG. 7 is a cross-sectional view of a shock absorbing member according to a modification. FIG. 8 is a cross-sectional view of an impact absorbing member according to a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Shock-absorbing structure 11 Shock-absorbing member 12a Outer surface part 12b Inner surface part 12c Plane part 13 Bead 14 Protruding member 15 Channel member 16 Channel member 17 Guide member 18 Plate member

Claims (5)

  A shock absorbing structure for a vehicle vehicle frame having a rectangular tube-shaped shock absorbing member extending in the front-rear direction of the vehicle vehicle frame, the space between the outer surfaces of the shock absorbing member being spaced in the longitudinal direction of the shock absorbing member. A plurality of convex beads for buckling deformation of the shock absorbing member and an inner surface portion of the shock absorbing member between the plurality of beads. Is arranged in a direction perpendicular to the longitudinal direction of the shock absorbing member, one end is fixed to the inner surface portion of the shock absorbing member and the other end is spaced from the inner surface portion of the facing surface, and occurs with the bead as a base point. A shock absorbing structure for a vehicle frame, comprising: a projecting support member for limiting a deformation amount of buckling deformation of the shock absorbing member.   The other end of the projecting support member is formed on the inner surface of the impact absorbing member so that the other end of the projecting support member is opposed to the other end of the projecting support member. The shock absorbing structure for a vehicle frame according to claim 1, further comprising a guide member for guiding in a direction orthogonal to the longitudinal direction of the member.   The shock absorbing structure for a vehicle frame according to claim 1 or 2, wherein a plate-like member formed so as to face the inner surface of the shock absorbing member is attached to the other end of the projecting support member.   4. The shock absorbing structure for a vehicle frame according to claim 1, wherein a plurality of the projecting support members are provided at intervals in the longitudinal direction of the shock absorbing member. 5.   The shock absorbing structure for a vehicle frame according to any one of claims 1 to 4, wherein the shock absorbing member is formed by joining a pair of groove members facing each other.

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