JP4349330B2 - Body structure - Google Patents

Description

  The present invention relates to a vehicle body structure in which a lower skeleton member is provided below a side member.

2. Description of the Related Art Conventionally, as a vehicle body structure in which a lower skeleton member is provided below a side member, as described in Japanese Patent Application Laid-Open No. 2003-146242, a subframe is disposed below a side frame extending in the front-rear direction of the vehicle. A combination of subframes at the front end portion and the rear portion thereof is known. This vehicle body structure is intended to absorb a shock by deforming a subframe together with a side frame at the time of a collision.
JP 2003-146242 A

  However, in such a vehicle body structure, there is a possibility that a compressive force acts on both the side frame and the sub frame at the time of a collision, and the collision load is transmitted to the rear of the side frame through the sub frame. In this case, it will deform | transform to the back of a side frame by a collision.

  Therefore, an object of the present invention is to provide a vehicle body structure capable of efficiently absorbing shock at the time of a collision in a front portion of a vehicle.

  That is, the vehicle body structure according to the present invention includes a side member extending in the vehicle front-rear direction, a lower skeleton member coupled to the side member and provided below the side member, a tip of the side member, and the lower skeleton member. And a tension transmission member that transmits the tension without transmitting the compression force.

  According to the present invention, when a tension transmitting member that transmits tension without transmitting compressive force is coupled between the tip of the side member and the lower skeleton member, the vehicle collides with a vehicle having a vehicle height lower than the own vehicle ( When a collision load is applied to the tension transmission member (especially when the front side member of the other vehicle is lower than the front side member of the host vehicle), the tension is transmitted to the tip of the side member by the tension transmission member, and the tip of the side member By deforming the portion downward, it is possible to efficiently absorb the shock at the front portion of the vehicle. In addition, when a collision load is applied to the side member, such as when the vehicle collides with a vehicle having the same height as the own vehicle (particularly when the front side member of the own vehicle and the front side member of the other vehicle are substantially at the same height) Although the side member is compressed and deformed, the compression force is not transmitted from the side member to the lower skeleton member through the tension transmitting member. For this reason, in a light collision, the lower skeleton member is not deformed, and only the tip of the side member needs to be repaired, so that the repair cost can be reduced.

  In the vehicle body structure according to the present invention, it is preferable that the side member has a bent portion that reduces the bending strength on the distal end side relative to the rear side of the connecting portion with the lower skeleton member.

  According to the present invention, when a collision load is applied to the tension transmission member such as when the vehicle collides with a vehicle whose vehicle height is lower than the own vehicle, the tension is transmitted to the bent portion at the tip of the side member by the tension transmission member, and the bending is performed. The part bends downward and deforms. By this bending deformation, an impact can be efficiently absorbed at the front portion of the vehicle. At that time, deformation of the bent portion prevents the lower skeleton member from being deformed by tension. For this reason, in the case of a light collision, the lower skeleton member is not deformed, and only the repair of the tip end portion of the side member is required, and the repair cost can be reduced.

  Further, in the vehicle body structure according to the present invention, it is preferable that the side member has a buckling portion having a buckling strength smaller than that of the rear side on the tip side from the connecting portion with the lower skeleton member.

  According to the present invention, when a collision load is applied to the tension transmission member, such as when the vehicle collides with a vehicle having a vehicle height lower than that of the host vehicle, the tension is transmitted to the buckled portion at the tip of the side member by the tension transmission member. The buckled portion buckles and deforms. By this buckling deformation, shock absorption can be efficiently performed at the front portion of the vehicle. At that time, the buckling portion is deformed, so that the lower skeleton member is prevented from being deformed by tension. For this reason, in the case of a light collision, the lower skeleton member is not deformed, and only the repair of the tip end portion of the side member is required, and the repair cost can be reduced.

  According to the present invention, shock absorption at the time of a collision can be efficiently performed at the front portion of the vehicle.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.
(First embodiment)
FIG. 1 is a schematic configuration diagram of a vehicle body structure according to an embodiment of the present invention.

  As shown in FIG. 1, the vehicle body structure according to the present embodiment is a vehicle body structure provided in a vehicle, and includes a side member 1, a lower cross member 2, and wires 3. The side members 1 are skeletal members that extend in the vehicle front-rear direction. For example, one side member 1 is disposed on each of the left and right sides of the vehicle. An energy absorbing portion 11 is provided at the tip of the side member 1. The energy absorbing unit 11 absorbs the collision energy when the vehicle collides, and has a structure that is easily deformed by receiving external force from the other part of the side member 1.

  The energy absorbing portion 11 is formed of, for example, a member having a lower strength than the other portions of the side member 1, and is formed of a steel material that is thinner than the other portions of the side member 1. The structure is easier to deform than the part. When a collision load is received from the front of the vehicle, the energy absorbing portion 11 buckles before other portions of the side member 1 and absorbs the collision energy by deformation due to the buckling. In that case, the energy absorption part 11 functions as a buckling part whose buckling strength is smaller than other parts of the side member 1.

  A flange 11 a is formed at the rear end portion of the energy absorbing portion 11. The energy absorbing portion 11 is flange-connected to the portion of the side member 1 behind the flange 11a by screws. A bumper reinforcement 4 is provided at the tip of the energy absorbing portion 11. The bumper reinforcement 4 is a member for efficiently distributing the collision load to the left and right side members 1, arranged in the vehicle width direction, and attached to the left and right energy absorbing portions 11, 11. Yes.

  The lower cross member 2 is a lower skeleton member provided below the side member 1, and is coupled to the lower portion of the side member 1. Both ends of the lower cross member 2 are attached to the left and right side members 1 and are arranged in the vehicle width direction. The lower cross member 2 is preferably attached to the side member 1 by inserting the base end portion of the lower cross member 2 into the lower portion of the side member 1. By attaching in this way, the lower cross member 2 is less likely to be detached from the side member 1 even if it receives a horizontal force.

  A wire 3 is coupled between the tip of the side member 1 and the lower cross member 2. The wire 3 functions as a tension transmission member that transmits the tension without transmitting the compressive force between the side member 1 and the lower cross member 2. One end of the wire 3 is attached to a bumper reinforcement 4 attached to the tip of the side member 1, and the other end of the wire 3 is attached to the lower part of the lower cross member 4. One end of the wire 3 may be directly attached to the side member 1. Further, as a tension transmitting member other than the wire 3, other members such as a chain and a reinforced resin fiber material may be used as long as they can transmit a tension without transmitting a compressive force. Also good.

  Next, shock absorption at the time of collision of the vehicle body structure according to the present embodiment will be described.

  2-5 is explanatory drawing about the impact absorption at the time of the collision of the vehicle body structure which concerns on this embodiment. As shown in FIG. 2, when a vehicle A equipped with the vehicle body structure according to the present embodiment and a vehicle B with a low vehicle height collide frontally, the lower cross member in which the frame 91 of the vehicle B is below the energy absorbing portion 11. It approaches towards 2.

  As shown in FIG. 3, when the vehicle A and the vehicle B further approach, the frame 91 of the vehicle B comes into contact with the wire 3 before coming into contact with the lower cross member 2. At this time, a collision load is applied to the wire 3. At that time, the wire 3 transmits the collision load as tension to the bumper reinforcement 4 and the lower cross member 2 at the tip of the side member 1.

  Due to this tension, the energy absorbing portion 11 at the tip of the side member 1 is bent downward. The impact of the collision can be absorbed by the bending deformation at that time. At this time, if the collision load is less than or equal to a predetermined value, the lower cross member 2 and the side member 1 behind the connecting portion of the lower cross member 2 are not damaged.

  As shown in FIG. 4, when a vehicle A having the vehicle body structure according to the present embodiment and a vehicle C having the same vehicle height collide head-on, the frame 92 of the vehicle C approaches the side member 1.

  As shown in FIG. 5, when the vehicle A and the vehicle B further approach, the frame 92 of the vehicle C comes into contact with the lower cross member 2 at the tip of the side member 1. Thereby, the collision load is transmitted in the axial direction of the side member 1, and the low-strength energy absorbing portion 11 is compressed and deformed to absorb the impact.

  On the other hand, the collision load is transmitted to the wire 3 by the frame 92 of the vehicle C coming into contact with the lower cross member 2. However, since the wire 3 transmits only the tension and does not transmit the compressive force, the collision load is not transmitted to the lower cross member 2 and the side member 1 through the wire 3. For this reason, the lower cross member 2 or the side member 1 is not damaged by the collision load transmitted through the wire 3.

  As described above, according to the vehicle body structure according to the present embodiment, the vehicle 3 is coupled with the wire 3 that transmits the tension without transmitting the compressive force between the tip of the side member 1 and the lower cross member 2. When a collision load is applied to the wire 3 such as when the vehicle collides with a vehicle having a lower vehicle height, tension is transmitted to the tip of the side member 1 by the wire 3 and the tip of the side member 1 is deformed downward. Thus, it is possible to efficiently absorb the shock at the front portion of the vehicle.

  In addition, when the front end portion of the side member 1 is bent and deformed at the beginning of the collision, the overhang of the host vehicle is shortened. As a result, it is possible to lengthen the time required for the frame such as the side member 1 of the own vehicle to reach the A-pillar of the opponent vehicle at the time of the collision, and it is possible to reduce damage and improve safety of the opponent vehicle.

  On the other hand, when a collision load is applied to the side member 1 such as when the vehicle collides with a vehicle having the same vehicle height as the own vehicle, the side member 1 is compressed and deformed, but the compression force is applied from the side member 1 to the lower cross member 2 through the wire 3. Is not transmitted. For this reason, in a light collision, there is no deformation in the lower cross member 2 and the rear portion of the lower cross member 2. Therefore, only the tip of the side member 1 needs to be repaired, so that the repair cost can be reduced. Further, since the wire 3 itself is not damaged by the compressive load, repair or the like is unnecessary, and the repair cost can be reduced.

Further, by providing the wire 3, it is possible to strengthen the connection and support of the bumper reinforcement 4 installed far from the center of gravity of the vehicle. For this reason, it is possible to improve steering stability and vibration noise characteristics.
(Second embodiment)
Next, the vehicle body structure according to the second embodiment of the present invention will be described.

  6 and 7 are schematic explanatory views of the vehicle body structure according to the present embodiment. As shown in FIG. 6, the vehicle body structure according to the present embodiment is configured in substantially the same manner as the vehicle body structure according to the first embodiment described above, except that a bent portion 11 b is provided on the side member 1. This is different from the vehicle body structure according to the first embodiment.

  The bent portion 11b reduces the bending strength of the tip side of the side member 1 with respect to the rear side of the connecting portion with the lower cross member 2, and is provided as a groove formed in the energy absorbing portion 11, for example. That is, the bent portion 11 b is provided as a groove cut along the vehicle width direction on the upper and lower surfaces of the energy absorbing portion 11. By forming the bent portion 11b, when a bending load is applied to the side member 1, the side member 1 is easily bent starting from the bent portion 11b, and the tip side of the side member 1 is easily bent.

  For example, as shown in FIG. 7, when a vehicle A having the vehicle body structure according to the present embodiment and a vehicle B having a low vehicle height collide head-on, before the frame 91 of the vehicle B comes into contact with the lower cross member 2. In contact with the wire 3. At this time, a collision load is applied to the wire 3, and the wire 3 transmits the collision load as tension to the bumper reinforcement 4 and the lower cross member 2 at the tip of the side member 1.

  Due to this tension, a bending load is applied to the tip of the side member 1. Then, the side member 1 bends downward from the bent portion 11b, and the impact of the collision is absorbed by the bending deformation at that time. At this time, if the collision load is below a predetermined value and is small, the lower cross member 2 and the side member 1 behind the lower cross member 2 connecting portion are not damaged.

  As described above, even in the vehicle body structure according to this embodiment, the same effects as those of the first embodiment described above can be obtained. In addition, in the event of a collision, the tip side of the side member 1 can be bent more reliably to absorb the impact. Therefore, the shock can be efficiently absorbed at the front portion of the vehicle, and the repair cost can be reduced. Further, when the bent portion 11b is formed by engraving a groove, the groove portion can be a starting point of buckling at the time of collision, and can function as a buckling portion.

  Each embodiment described above shows an example of a vehicle body structure according to the present invention. The vehicle body structure according to the present invention is not limited to such a structure, and may be modified so as not to change the gist described in each claim.

1 is a schematic configuration diagram of a vehicle body structure according to a first embodiment of the present invention. It is explanatory drawing of the impact absorption in the vehicle body structure of FIG. It is explanatory drawing of the impact absorption in the vehicle body structure of FIG. It is explanatory drawing of the impact absorption in the vehicle body structure of FIG. It is explanatory drawing of the impact absorption in the vehicle body structure of FIG. It is a composition outline figure of the body structure concerning a second embodiment of the present invention. It is explanatory drawing of the impact absorption in the vehicle body structure of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Side member, 2 ... Lower cross member (lower frame member), 3 ... Wire (tension transmission member), 4 ... Bumper reinforcement

Claims (3)

A side member extending in the longitudinal direction of the vehicle;
A lower skeleton member coupled to the side member and provided below the side member;
A tension transmission member that is coupled between the tip of the side member and the lower skeleton member, and transmits a tension without transmitting a compressive force;
Body structure with   2. The vehicle body structure according to claim 1, wherein the side member has a bent portion that reduces a bending strength at a tip end side with respect to a rear side of a connecting portion with the lower skeleton member. 3. The vehicle body structure according to claim 1, wherein the side member has a buckling portion having a buckling strength lower than that of the rear side of the joint portion with the lower skeleton member.

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