JP2012030624A - Automobile bumper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automobile bumper that enables a crash box to have sufficient energy absorbing performance without increasing the number of parts when a bumper beam and a side member are to be installed at different heights.SOLUTION: The crash box 2 is inclined (downward or) upward to forward of an automobile. As a result, even if the height of the side member 1 of a vehicle body is (high) low, the bumper beam 3 attached to the distal end of the crash box 2 is located (low) high. Therefore, upon collision with another vehicle 4, the bumper beams collide with each other, thereby preventing the vehicle body from entering under the other vehicle 4. The load of the collision does not cause torsion deformation in the bumper beam 3, no eccentric load is applied to the crash box 2, and the crash box 2 can exert sufficiently-high energy absorbing performance.

Description

  The present invention relates to an automobile bumper that prevents one vehicle from entering or climbing into an opponent vehicle when two vehicles having different bumper beam mounting heights collide.

  One of the roles of the bumper of an automobile is to suppress damage to the vehicle when the automobile collides with a wall or a collision accident occurs with another vehicle or the like. However, the bumper mounting height of an automobile varies depending on the type of vehicle, and the bumper beam mounting height and the side member height are often offset to cope with collisions between different vehicles. Various tests for safety testing have been proposed and implemented by IIHS (American Road Safety Insurance Association) and RCAR (The Research Council for Automobile Repairs). A standard test method is also being established for the bumper barrier. For example, in IIHS, the bumper barrier to be tested is installed at a position where the bumper lower end is 457 mm from the ground. Conventionally, bumper heights of automobiles differed individually, but in order to obtain high evaluation in the standardized test as described above, there is a tendency to install the bumper barrier and wrap amount at a height that increases. Strengthen. In that case, since the chassis and the bumper height do not necessarily match, they are installed with an offset.

  In this way, when the bumper beam mounting height is offset from the side member height, conventionally, the crash box and the bumper beam are offset and mounted, so that the bumper beam is likely to be twisted at the time of collision. There is a problem. In addition, since an eccentric load is input to the crash box, there is a problem in that the energy absorption performance cannot be sufficiently exhibited.

  In addition, when vehicles with different bumper mounting heights collide with each other, it is easy to get into the opponent vehicle or to get on. In order to avoid this, a raised wall called an overrider or the like may be provided above the bumper reinforcing material (Patent Document 1).

  FIG. 8 is a schematic diagram showing a bumper beam to which a conventional overrider is attached. A crash box 2 is attached to the tip of a side member 1 constituting the body of the automobile, and a bumper beam 3 is attached to the crash box 2. And when the side member 1 which comprises the vehicle body of a motor vehicle is lower than the other vehicle 4, the overrider (lifting wall) 5 is provided on the bumper beam 3. FIG. The overrider 5 prevents the vehicle body from sinking under the opponent vehicle 4 at the time of a collision.

JP 2007-261525 A

  However, installing such an overrider 5 is not preferable because it leads to an increase in the number of parts.

  Therefore, instead of installing the overrider 5, for example, if the bumper beam 3 of FIG. 8 is mounted at a higher position with respect to the crash box 2, the height consistency with the bumper beam of the opponent vehicle 4 can be taken. However, the bumper beam 3 is twisted by a load applied to the bumper beam 3 at the time of collision. Further, an eccentric load is input to the crash box 2, and the energy absorption performance of the original crash box cannot be sufficiently exhibited. This situation is the same when the crash box 2 is attached to the side member 1 at a higher position.

  The present invention has been made in view of such problems, and when it is necessary to make the mounting height of the bumper beam and the side member different, the number of parts does not increase and the crash box has sufficient energy. An object of the present invention is to provide an automobile bumper that can exhibit absorption performance.

  An automobile bumper according to the present invention is an automobile bumper that absorbs collision energy in the event of a vehicle collision, a crash box fixed to a side member of a vehicle body, and a bumper beam fixed to the crash box and extending in the vehicle body width direction. The crash box is inclined downward or upward with respect to a direction away from the vehicle body in the longitudinal direction thereof, whereby the heights of both the bumper beam and the side member are offset, and the bumper beam The height is adjusted so as to be within the range of the standard value.

  In this case, when the energy absorption part of the crush box is formed of aluminum or an aluminum alloy extruded profile and has a hollow or cross-sectional structure having a rectangular or medium rib, the position of the side member is the bumper beam. When the position of the side member is higher than the position of the bumper beam, the thickness of the upper surface of the crash box is lower than the thickness of the bumper beam. It is preferable that the thickness is smaller.

  In addition, when the energy absorbing portion of the crash box is made of steel, when the position of the side member is lower than the position of the bumper beam, the thickness of the lower surface of the crash box is thinner than the thickness of the upper surface. Conversely, when the position of the side member is higher than the position of the bumper beam, the thickness of the upper surface of the crash box is preferably thinner than the thickness of the lower surface.

  Further, when the energy absorbing portion of the crash box is made of steel, when the position of the side member is lower than the position of the bumper beam, the material strength of the lower surface of the crash box is higher than the material strength of the upper surface. On the contrary, when the position of the side member is higher than the position of the bumper beam, the material strength of the upper surface of the crash box is preferably lower than the material strength of the lower surface.

  In the present invention, the crash box is inclined downward or upward toward the front of the automobile (forward in the case of the front end of the automobile and rearward in the case of the rear end). For this reason, the bumper beam attached to the tip of the crash box falls within the range of the standard value of the bumper beam. That is, as shown in FIG. 1, when the vehicle body 1 is low, a crash box 2 inclined upward is used, and a bumper beam 3 is attached to the tip thereof. For this reason, since the bumper beam 3 is higher than the side member 1 of the vehicle body and falls within the range of the standard value, the height of the bumper of the opponent vehicle (the bumper beam is indicated by a broken line) at the time of collision with the opponent vehicle 4 If it is within the range of the standard value, the bumper beams collide with each other, and the vehicle body does not sink into the opponent vehicle 4. In this case, since the crash box 2 is inclined, the collision load applied to the bumper beam 3 does not cause torsional deformation in the bumper beam 3, and an eccentric load is applied to the crash box 2. No, the crash box 2 can exhibit a sufficiently high energy absorption performance. The same applies when the vehicle body is tall.

It is a schematic diagram which shows the concept of this invention. (A) is a figure which shows the bumper for motor vehicles concerning 1st Embodiment of this invention, (b) is a longitudinal cross-sectional view of the crush box 2. As shown in FIG. (A) is a figure which shows the bumper for motor vehicles based on 2nd Embodiment of this invention, (b) is a longitudinal cross-sectional view of the crash box 2. As shown in FIG. (A) is a figure which shows the bumper for motor vehicles concerning 3rd Embodiment of this invention, (b) is a longitudinal cross-sectional view of the crush box 2. As shown in FIG. (A) is a figure which shows the bumper for motor vehicles concerning 4th Embodiment of this invention, (b) is a longitudinal cross-sectional view of the crush box 2. As shown in FIG. It is a schematic diagram which shows the deformation | transformation operation | movement of a crash box. It is a schematic diagram which similarly shows the deformation | transformation operation | movement of a crash box. It is a schematic diagram which shows the conventional bumper for motor vehicles.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. As shown in FIG. 2, in the first embodiment, the crash box 2 is fixed to the front end or rear end (hereinafter referred to as the front end) of the side member 1, and the bumper beam 3 is fixed to the front end of the crash box 2. ing. The crash box 2 has a cylindrical shape with a rectangular cross section, and has a hollow cross-sectional structure. The crash box 2 is inclined upward from the tip of the side member 1 toward the front. That is, the crash box 2 is inclined upward in the direction away from the vehicle body in the longitudinal direction.

  Thereby, when the vehicle body is low, that is, when the side member 1 is low, the bumper beam 3 is higher than the side member 1 and enters the standard range of the height position of the bumper beam. Therefore, the difference in height of the bumper beam with respect to the opponent vehicle 4 is eliminated, and the vehicle does not sink below the opponent vehicle 4 in the event of a collision.

  Further, there is no vertical offset between the bumper beam 3 and the crash box 2 and between the crash box 2 and the side member 1. Accordingly, torsional deformation of the bumper beam at the time of collision is prevented, and an eccentric load is not input to the crash box 2, and the original energy absorption performance of the crash box 2 is exhibited.

  And, in the crash box 2 attached so as to be inclined in this way, the energy absorption part of the crash box 2 is formed of aluminum or an aluminum alloy extruded shape, and the extrusion direction of the energy absorption part is the longitudinal direction of the vehicle body, Furthermore, as shown in FIG. 2, when the height of the side member 1 is lower than the bumper beam 3, the height of the side member 1 and the bumper beam 3 is different in the crash box 2 in addition to the compressive force. Therefore, the compressive load on the upper surface 2a side of the crash box 2 is higher than the compressive load on the lower surface 2b side. As a result, when the thickness of the upper surface 2a and the lower surface 2b of the crash box 2 at the time of collision is equal, the compressive stress is higher on the upper surface 2a side than on the lower surface 2b side, as shown in FIG. However, buckling deformation occurs more easily than the lower surface 2b. For this reason, the collapse of the crash box 2 and the torsional deformation of the bumper beam 3 are likely to occur. Therefore, by making the thickness of the upper surface 2a thicker than the thickness of the lower surface 2b so that the compressive stress is equal between the lower surface 2b and the upper surface 2a, or the upper surface 2a is lower, as shown in FIG. The buckling deformation on the lower surface 2b side is more likely to occur than on the upper surface 2a side, and the collapse deformation of the crash box 2 and the twist deformation of the bumper beam at the time of collision are prevented.

  FIG. 3 is a view of a bumper showing a second embodiment of the present invention. This 2nd Embodiment is a thing in the case of the vehicle whose height of the side member 1 is higher than a normal vehicle type. In this case, the crush box 2 which inclines downward toward the front with respect to the side member 1 is provided. Fix it. For this reason, the bumper beam 3 attached to the crash box 2 is lower than the side member 1 and enters a range of a predetermined standard value. For this reason, it will collide with the other party's vehicle by bumper beams 3, and there exists an effect similar to 1st Embodiment shown in FIG.

  As shown in FIG. 3, when the height of the side member 1 is higher than that of the bumper beam 3, the compressive stress acting on the crash box 2 is increased by making the thickness of the lower surface 2d thicker than the thickness of the upper surface 2c. Is equal on the upper surface 2c and the lower surface 2d, or the lower surface 2d is smaller, so that the buckling deformation on the upper surface 2c side is more likely to occur than on the lower surface 2d side, and the crash box 2 collapses in the event of a collision. And the twist of the bumper beam 3 is prevented.

  In addition, as shown in FIG. 2, when the height of the side member 1 is lower than the bumper beam 3, the energy absorption part of the crush box 2 is made of steel, and a plurality of cross sections of the energy absorption part are hollow. In the case of a combination of steel plates, in addition to compressive force, a moment is also generated due to the difference in height between the side member 1 and the bumper beam 3 at the time of collision. Becomes higher. As a result, when the plate thickness of the upper surface 2a and the lower surface 2b of the crash box 2 at the time of collision is equal, the compressive stress is higher on the upper surface 2a side than on the lower surface 2b side, and the upper surface 2a is buckled more than the lower surface 2b. Deformation is likely to occur, and the crash box 2 collapses and the accompanying torsional deformation of the bumper beam 3 also easily occurs. Therefore, in this case, the plate thickness of the upper surface 2a is made thicker than the plate thickness of the lower surface 2b, and the compressive stress is equal between the lower surface 2b and the upper surface 2a, or the compressive stress is lower in the upper surface 2a than in the lower surface 2b. By doing so, buckling deformation on the lower surface 2b side is more likely to occur than on the upper surface 2a side, and it is possible to prevent the collapse of the crash box and the twisting of the beam at the time of collision.

  On the contrary, as shown in FIG. 3, when the height of the side member 1 is higher than the bumper beam 3, the thickness of the lower surface 2d is made thicker than the thickness of the upper surface 2c, and the compressive stress is increased between the upper surface 2c and the lower surface 2d. Or by making the lower surface 2d lower than the upper surface 2c, buckling deformation on the upper surface 2c side is more likely to occur than on the lower surface 2d side. Is prevented from being twisted.

  The energy absorption part of the crash box 2 is made of steel, and a plurality of steel plates are combined so that the cross section of the energy absorption part is hollow, and the height of the side member 1 is higher than the bumper beam 3 as shown in FIG. If the thickness is low, as in the case of the extruded shape of aluminum or aluminum alloy, if the plate thickness of the upper surface 2a and the lower surface 2b of the crush box 2 is the same and the material strength is the same, the side member and bumper in addition to the compressive force at the time of collision Since moments are generated due to different beam heights, the compressive load on the upper surface side is higher. As a result, if the plate thickness and material strength of the upper and lower surfaces of the crash box at the time of collision are the same, the upper surface is more likely to buckle than the lower surface, so that the crash box 2 collapses and the associated beam twists. Deformation is also likely to occur. Therefore, by making the material strength of the upper surface 2a of the crash box 2 higher than that of the lower surface 2b and causing the buckling stress of the upper surface 2a to be higher, buckling deformation on the lower surface 2b side occurs than on the upper surface 2a side. It becomes easy to prevent the crash box 5 from falling down and torsional deformation of the beam at the time of collision.

  On the other hand, as shown in FIG. 3, when the height of the side member 1 is higher than that of the bumper beam 3, the material strength of the lower surface 2d is made higher than that of the upper surface 2c, and the buckling stress of the lower surface 2d is higher. By doing so, buckling deformation on the upper surface 2c side is more likely to occur than on the lower surface 2d side, and it is possible to prevent the crash box 2 from falling down and the bumper beam 3 from twisting during collision.

  FIG. 4 is a schematic view showing a third embodiment of the present invention. There is a rib at the center of the outer surface of the crash box 2 in the height direction, and the crash box 2 has a hollow cross-sectional structure having an intermediate rib. In this case, since the bumper beam 3 is higher than the side member 1, the crash box 2 is inclined upward toward the front. In this case, it is preferable to make the upper surface 2e of the crash box 2 thicker and / or stronger than the lower surface 2f for the reasons described above.

  FIG. 5 is a schematic view showing a fourth embodiment of the present invention. There is a rib at the center of the outer surface of the crash box 2 in the height direction, and the crash box 2 has a hollow cross-sectional structure having an intermediate rib. In this case, it is preferable to make the upper surface 2g of the crash box 2 thinner and / or lower in strength than the lower surface 2h for the reasons described above.

  In the crash box mounted in such an inclination, the energy absorption part of the crash box is made of an aluminum alloy extruded shape, the extrusion direction of the energy absorption part is the vehicle body front-rear direction, and as shown in FIG. When the height of the member 1 is lower than the bumper beam 3, the crash box 2 generates a moment due to the difference in height between the side member 1 and the bumper beam 3 in addition to the compressive force. 2, the compressive load on the upper surface side is higher than that on the lower surface side. As a result, when the thickness of the upper and lower surfaces of the crash box 2 at the time of collision is equal, the compressive stress is higher on the upper surface side than on the lower surface side, and as shown in FIG. Therefore, the crash box 2 falls and the torsional deformation of the beam easily occurs. Therefore, the thickness on the upper surface side is made thicker than the thickness on the lower surface side, or the material strength on the upper surface side is made higher than that on the lower surface side, so that the compressive stress is the same on the lower surface and the upper surface, or the upper surface is lower. By doing so, buckling deformation on the lower surface side is more likely to occur than on the upper surface side, and as shown in FIG. 7, the deformation of the crash box and the twisting of the beam at the time of collision are prevented.

  On the contrary, when the height of the side member 1 is higher than the bumper beam 3, the thickness of the lower surface side of the crash box 2 is made thicker than the thickness of the upper surface side, or the material strength of the lower surface side becomes higher than the upper surface side. By making the compressive stress equal to the upper surface and the lower surface, or lower on the lower surface, buckling deformation on the upper surface side is more likely to occur than on the lower surface side, and the crash box collapses due to collision and the beam Is prevented from being twisted.

  The same applies when the energy absorption part of the crash box 2 is made of steel and a plurality of steel plates are combined so that the cross section of the energy absorption part is hollow.

1: Side member 2: Crash box 3: Bumper beam 4: Opponent vehicles 2a, 2c, 2e, 2g: Upper surface 2b, 2d, 2f, 2h: Lower surface

Claims (4)

In an automobile bumper that absorbs collision energy at the time of a vehicle collision, the vehicle has a crash box fixed to a side member of the vehicle body, and a bumper beam fixed to the crash box and extending in the vehicle body width direction. With respect to the direction away from the vehicle body in the longitudinal direction, it is inclined downward or upward, so that the height of both the bumper beam and the side member is offset, and the height of the bumper beam is within the range of the standard value. Automotive bumper characterized by being adapted to enter. The crash box has a hollow cross-sectional structure in which the energy absorbing portion is formed of aluminum or an aluminum alloy extruded shape, and has a rectangular or medium rib.
When the position of the side member is lower than the position of the bumper beam, the thickness of the lower surface of the crash box is thinner than the thickness of the upper surface, and conversely, the position of the side member is higher than the position of the bumper beam. The automobile bumper according to claim 1, wherein the thickness of the upper surface of the crash box is thinner than the thickness of the lower surface. The crash box has a hollow cross-sectional structure in which the energy absorption part is made of steel and has a rectangular or medium rib.
When the position of the side member is lower than the position of the bumper beam, the thickness of the lower surface of the crash box is thinner than the thickness of the upper surface, and conversely, the position of the side member is higher than the position of the bumper beam. The automobile bumper according to claim 1, wherein the thickness of the upper surface of the crash box is thinner than the thickness of the lower surface. The crash box has a hollow cross-sectional structure in which the energy absorption part is made of steel and has a rectangular or medium rib.
When the position of the side member is lower than the position of the bumper beam, the material strength of the lower surface of the crash box is lower than the material strength of the upper surface, and conversely, the position of the side member is higher than the position of the bumper beam. 2. The automobile bumper according to claim 1, wherein the material strength of the upper surface of the crash box is lower than the material strength of the lower surface.

Images