Bumper assembly

Abstract

To provide a bumper assembly that is equipped with a load transmission member capable of further effectively transmitting a load of collision in a small overlap test to a skeleton of a vehicle body.SOLUTION: A bumper assembly 100A is equipped with: a beam 10 that extends in a vehicle width direction of a vehicle while being attached to the vehicle; an energy absorbing member 20 that is joined with a rear surface of the beam; and a load transmission member 30A that is located between a position of the beam 10 with which a barrier is collided in an SOT and the energy absorbing member 20, and is joined to a rear surface of the beam so as to overlap with at least a part of the energy absorbing member in the vehicle width direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a bumper assembly disposed at the front of a vehicle.

Background Art

[0002] In recent years, as a type of offset frontal collision test for improving the safety performance of vehicles, a Small Overlap Test (SOT) has been introduced. The SOT was implemented and announced by the IIHS (Insurance Institute for Highway Safety) in the United States at the end of 2012. It is a partial collision test in which 25% (1 / 4) of the driver's side on the front of the vehicle is collided with a collision barrier (hereinafter referred to as the barrier) at a speed of 40 miles per hour (about 64 km).

[0003] In order to improve the safety performance in the Small Overlap Test, for example, Patent Document 1 discloses a vehicle body end structure including a pair of skeleton members symmetrically disposed with a power unit interposed therebetween, a bumper skeleton portion connected to the tip portions of the pair of skeleton members, and a spacer member protruding from the overhanging portion of the bumper skeleton portion toward the skeleton member side. Each skeleton member has a front side member and a crush box (energy absorption member, also referred to as a "stay") provided at the front end of the front side member. The spacer member (slide spacer) is disposed between the overhanging portion of the bumper reinforcement (also referred to as a "beam") and the skeleton member, and functions as a load transmission member that converts the backward load input to the overhanging portion into a load inward in the vehicle width direction and transmits it to the vicinity of the front end of the front side member (see, for example, FIG. 1 of Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, according to the inventors' research, the configuration in Patent Document 1 does not necessarily allow the spacer member to effectively transmit the collision load in the small overlap test to the vehicle body frame, and there is room for improvement.

[0006] Therefore, the present invention aims to provide a bumper assembly equipped with a load transmission member that can more effectively transmit collision loads in small overlap tests to the vehicle body frame. [Means for solving the problem]

[0007] According to embodiments of the present invention, the following solutions are provided.

[0008] [Item 1] A bumper assembly that is attached to the front of a vehicle, In the state in which it is attached to the aforementioned vehicle, A beam extending in the width direction of the vehicle, An energy absorbing member bonded to the rear surface of the beam, A load transmission member is located between the position of the beam where the barrier collides in the SOT (Small Overlap Test) and the energy absorbing member, and is joined to the rear surface of the beam so as to overlap with at least a portion of the energy absorbing member in the vehicle width direction. A bumper assembly having the following features.

[0009] [Item 2] In the state in which it is attached to the aforementioned vehicle, The load transmission member is In a cross-section parallel to the horizontal plane, the plate-like portion includes a flat plate portion that extends along the beam and overlaps with at least a portion of the energy absorbing member in the vehicle width direction, From the plate-shaped portion, a convex portion protrudes into the space between the rear surface of the beam and the energy absorbing member. The bumper assembly described in item 1, having the features of item 1.

[0010] [Item 3] The vehicle further has a plate that is joined to the frame of the aforementioned vehicle, The energy absorbing member is bonded to the plate, The plate has a peripheral portion that protrudes from the energy absorbing member in the vehicle width direction, In the state in which it is attached to the aforementioned vehicle, The bumper assembly according to item 2, wherein the convex portion of the load transmission member is located in the space between the rear surface of the beam, the energy absorbing member, and the plane extending the plate, in a cross section parallel to the horizontal plane.

[0011] [Item 4] The aforementioned convex portion is, in SOT, The bumper assembly according to item 3, having a first portion that contacts the peripheral portion of the plate.

[0012] [Item 5] The aforementioned convex portion is, in SOT, The bumper assembly according to item 4, further comprising a second portion that contacts the side of the energy absorbing member perpendicular to the plate.

[0013] [Item 6] The aforementioned convex portion is, in SOT, The bumper assembly according to item 5, further comprising a third portion that, in a cross-section parallel to the horizontal plane, is substantially parallel to a line connecting the position of the beam that the barrier collides with and the intersection point of the plate and the side surface of the energy absorbing member.

[0014] [Item 7] The rear surface of the beam has a recess, The plate-shaped portion of the load-transmitting member is fitted into the recess, the bumper assembly according to any one of items 2 to 6.

[0015] [Item 8] The bumper assembly according to any one of items 1 to 7, wherein the energy absorption member has a plurality of cylindrical portions extending in the longitudinal direction of the vehicle.

Effect of the Invention

[0016] According to an embodiment of the present invention, there is provided a bumper assembly capable of more effectively transmitting the impact load in a small overlap test to the vehicle body skeleton.

Brief Description of the Drawings

[0017] [Figure 1] It is a schematic plan view showing the positional relationship between the barrier BR and the bumper assembly 100 according to an embodiment of the present invention in a small overlap test (SOT). [Figure 2] It is a schematic exploded perspective view of the bumper assembly 100A according to an embodiment of the present invention. [Figure 3A] It is a schematic rear view of the bumper assembly 100A. [Figure 3B] It is a schematic cross-sectional view of the bumper assembly 100A taken along the line 3B-3B' in FIG. 3A. [Figure 3C] It is a schematic cross-sectional view of the bumper assembly 100A taken along the line 3C-3C' in FIG. 3A. [Figure 4A] It is a schematic top view showing the positional relationship between the barrier BR and the bumper assembly 100A at the moment of collision in SOT. [Figure 4B] It is a schematic top view showing the form of the bumper assembly 100A at the time of collision (initial stage) in SOT. [Figure 4C] It is a schematic top view showing the form of the bumper assembly 100A at the time of collision (mid-early stage) in SOT. [Figure 4D] It is a schematic top view showing the form of the bumper assembly 100A at the time of collision (mid-late stage) in SOT. [Figure 4E] It is a schematic top view showing the form of the bumper assembly 100A at the time of collision (late stage) in SOT. [Figure 5A]This is a schematic top view showing the positional relationship between the barrier BR at the moment of impact in SOT and the bumper assembly 200 of the comparative example. [Figure 5B] This is a schematic top view showing the configuration of the bumper assembly 200 in the initial stage of a collision in SOT. [Figure 5C] This is a schematic top view showing the configuration of the bumper assembly 200 in a collision (mid-to-early stage) in SOT. [Figure 5D] This is a schematic top view showing the configuration of the bumper assembly 200 in a collision (mid-to-late stage) in a SOT (Stand-on-the-Track) situation. [Figure 5E] This is a schematic top view showing the configuration of the bumper assembly 200 in a late-stage collision in SOT. [Figure 6] This is a load-stroke diagram showing the loads transmitted by the bumper assembly to the vehicle's frame in a standard-of-service (SOT) configuration. [Figure 7A] This is a schematic cross-sectional view of another bumper assembly 100B according to an embodiment of the present invention. [Figure 7B] This is a schematic cross-sectional view of yet another bumper assembly 100C according to an embodiment of the present invention. [Figure 7C] This is a schematic cross-sectional view of yet another bumper assembly 100D according to an embodiment of the present invention. [Modes for carrying out the invention]

[0018] A bumper assembly according to an embodiment of the present invention will be described below with reference to the drawings. The bumper assembly according to an embodiment of the present invention is not limited to those exemplified below.

[0019] Figure 1 shows a schematic plan view illustrating the positional relationship between the barrier BR and the bumper assembly 100 according to an embodiment of the present invention in a small overlap test (SOT). Here, a standard passenger car (left-hand drive) is shown as the vehicle VH. As shown in Figure 1, in the SOT, the front of the vehicle VH, at a point offset by W / 4 from the center CL of the vehicle width W, is brought into contact with the barrier BR at a speed v of 40 miles per hour (approximately 64 km / h).

[0020] The bumper assembly 100 according to an embodiment of the present invention is attached to the front of the vehicle VH and, when attached to the vehicle VH, comprises a beam 10 extending in the vehicle width direction of the vehicle VH, an energy absorbing member (stay) 20 joined to the rear surface of the beam 10, and a load transmission member 30 located between the position of the beam 10 where the barrier BR collides with the SOT (see point PS in Figure 4A, for example) and the energy absorbing member 20, and joined to the rear surface of the beam 10 so as to overlap with at least a portion of the energy absorbing member 20 in the vehicle width direction. The bumper assembly 100 further comprises a plate 40 joined to the frame FR of the vehicle VH, and the energy absorbing member 20 is joined to the plate 40. The plate 40 may be omitted, and the energy absorbing member 20 may be directly joined to the frame FR. In this case, the frame FR may have a portion that protrudes beyond the energy absorbing member 20 in the vehicle width direction. Here, the frame FR is included in the vehicle body's skeleton.

[0021] Next, the structure of the bumper assembly 100A according to an embodiment of the present invention will be described with reference to Figures 2, 3A, 3B, and 3C.

[0022] First, refer to Figure 2. Figure 2 is a schematic exploded perspective view of the bumper assembly 100A. The bumper assembly 100A includes a beam 10, an energy absorbing member 20, a load transmission member 30A, and a plate 40.

[0023] The energy absorbing member 20 is joined to the plate 40, and the plate 40 has a peripheral portion 40p that extends beyond the energy absorbing member 20 in the vehicle width direction. Here, the peripheral portion 40p also includes a portion that extends beyond the energy absorbing member 20 in the vertical direction. The plate 40 is joined to the vehicle frame (frame FR in Figure 1) for example, using bolts and nuts through holes 40h provided in the peripheral portion 40p.

[0024] The energy absorbing member 20 has a plurality of cylindrical portions 20t1, 20t2 extending in the longitudinal direction of the vehicle. The load transmission member 30A has a through hole 30h1 that penetrates in the vertical direction of the vehicle. The rear surface of the beam 10 has a groove-shaped recess 10g extending in the vehicle width direction, and a part of the load transmission member 30A is fitted into the recess 10g.

[0025] Next, the structure of the bumper assembly 100A will be described in more detail with reference to Figures 3A, 3B, and 3C. Figure 3A shows a schematic rear view of the bumper assembly 100A, Figure 3B shows a schematic cross-sectional view of the bumper assembly 100A along the line 3B-3B' in Figure 3A, and Figure 3C shows a schematic cross-sectional view of the bumper assembly 100A along the line 3C-3C' in Figure 3A. Note that in Figure 3A, the part hidden by the plate 40 is shown as if the plate 40 were not present. That is, from the front, the energy absorption member 20, the load transmission member 30, and the beam 10 are shown.

[0026] As shown in Figure 3B, the load transmission member 30A of the bumper assembly 100A has a plate-like portion 32 that extends along the beam 10 in a cross section parallel to the horizontal plane and includes a flat plate portion 32a that overlaps with a part of the energy absorption member 20 in the vehicle width direction, and a convex portion 34 that protrudes from the plate-like portion 32 into the space between the rear surface of the beam 10 and the energy absorption member 20. Here, the convex portion 34 is located in the space between the rear surface of the beam 10, the energy absorption member 20, and the plane extending from the plate 40. The convex portion 34 has a first portion 34a, a second portion 34b, and a third portion 34c, and together with portion 32b of the plate-like portion 32, forms a through hole 30h1. The load transmission member 30A having the first portion 34a, the second portion 34b, and the third portion 34c can efficiently transmit the collision load in SOT to the vehicle body frame FR, as will be described later with reference to Figures 4A to 4E.

[0027] The rear surface of the beam 10 has a groove-shaped recess 10g extending in the vehicle width direction, and the plate-shaped portion 32 of the load transmission member 30A is fitted into the recess 10g. At this time, the plate-shaped portion 32 is flush with the beam 10. By fitting the plate-shaped portion 32 into the recess 10g on the rear surface of the beam 10, the length of the energy absorption member 20 in the front-rear direction can be increased by the thickness of the plate-shaped portion 32, thereby increasing the amount of energy that can be absorbed by the energy absorption member 20. Alternatively, if the amount of energy absorbed remains the same, the overall length of the vehicle in the front-rear direction can be reduced.

[0028] The energy absorbing member 20 preferably has a plurality of cylindrical portions 20t1, 20t2 extending in the longitudinal direction of the vehicle, as illustrated here. The plurality of cylindrical portions 20t1, 20t2 are arranged in the vertical direction, but may also be arranged in the vehicle width direction. The energy absorbing member 20 may also have three or more cylindrical portions arranged in the vertical direction and / or the vehicle width direction. Energy is absorbed by the deformation of the wall portions constituting the plurality of cylindrical portions 20t1, 20t2.

[0029] Next, referring to Figures 4A to 4E, we will explain how the load transmission member 30A of the bumper assembly 100A can efficiently transmit the load to the vehicle frame FR in SOT. Figures 4A to 4E show the changes in the form of the bumper assembly 100A in SOT. Figures 4A to 4E show the form of the bumper assembly 100A obtained from collision simulations using the finite element method. The general-purpose finite element analysis software RADIOSS® was used for the simulations.

[0030] Figure 4A is a schematic top view showing the positional relationship between the barrier BR and the bumper assembly 100A at the moment of impact in SOT, and indicates the position (point PS) of the beam 10 that the barrier BR collides with. Figures 4B to 4E are schematic top views showing the initial, early-mid, late-mid, and late-stage configurations of the bumper assembly 100A in SOT, respectively.

[0031] As shown in Figure 4B, in the initial stages of the collision, when the beam 10 deforms, the load transmission member 30A attempts to move diagonally backward, and the load is transmitted to the energy absorption member 20 from the portion overlapping with the energy absorption member 20 (plate-shaped portion 32) toward the rear. Furthermore, the first portion 34a constituting the convex portion 34 of the load transmission member 30A comes into contact with the peripheral portion of the plate 40, and the load is transmitted to the frame FR via the convex portion 34. At this time as well, the load is transmitted to the energy absorption member 20 toward the rear from the plate-shaped portion 32 overlapping with the energy absorption member 20. In addition, a part of the energy absorption member 20 (the upper left corner in Figure 4B) is crushed by the load transmitted toward the rear from the plate-shaped portion 32.

[0032] Furthermore, as shown in Figure 4C, in the early to mid-stage of the collision, the second portion 34b constituting the convex portion 34 contacts the side surface of the energy absorbing member 20 perpendicular to the plate 40. The above-described relationship occurs when the angle between the first portion 34a and the second portion 34b of the convex portion 34 is approximately equal to the angle (perpendicular in this case) between the side surface of the energy absorbing member 20 and the peripheral portion of the plate 40. Also, the third portion 34c of the convex portion 34 is approximately parallel to the line connecting the position PS of the beam 10 into which the barrier BR collides and the intersection point of the plate 40 and the side surface of the energy absorbing member 20. At this time as well, a load is transmitted to the energy absorbing member 20 from the plate-like portion 32 overlapping with the energy absorbing member 20 toward the rear.

[0033] As described above, in the process from Figure 4A to Figure 4C, the load is efficiently transmitted from the load transmission member 30A to the vehicle frame FR. Furthermore, if the load transmission member 30A has at least a flat plate portion 32a that overlaps with a part of the energy absorption member 20 in the vehicle width direction, the load can be effectively transmitted to the vehicle frame FR via the energy absorption member 20. Of course, it is preferable to have a first portion 34a, a second portion 34b, and a third portion 34c as illustrated here, but it may have only one of these, or only two.

[0034] As can be seen from Figures 4C to 4E, the through hole 30h1 formed by the convex portion 34 and portion 32b of the plate-like portion 32 (see Figure 3B) is crushed. This indicates that even during the deformation process of the load transmission member 30A, the flat plate portion 32a, which overlaps with a part of the energy absorption member 20, continues to move backward, and the load is transmitted from the plate-like portion 32 toward the energy absorption member 20.

[0035] Figures 5A to 5E show the changes in the morphology of the bumper assembly 200 of the comparative example in SOT. The bumper assembly 200 does not have the load transmission member 30A of the bumper assembly 100A. Figure 5A is a schematic top view showing the positional relationship between the barrier BR and the bumper assembly 200 at the moment of impact in SOT, and shows the position (point PS) of the beam 10 that the barrier BR impacts. Figures 5B to 5E are schematic top views showing the morphology of the bumper assembly 200 in the initial, early-mid, late-mid, and late stages of the impact in SOT, respectively.

[0036] In the bumper assembly 200, in the later stages of a collision, as can be seen, for example from Figure 5E, the beam 10 may fracture at the joint with the energy-absorbing member 20. In contrast, in the bumper assembly 100A, as can be seen, for example from Figure 4E, the load-transmitting member 30A extends outward in the vehicle width direction from the plate-like portion 32 that overlaps with the energy-absorbing member 20, thus suppressing abrupt changes in the rigidity of the bumper assembly 100A in the vehicle width direction. Therefore, it is possible to suppress the fracture of the beam 10 at the joint with the energy-absorbing member 20.

[0037] Figure 6 shows a load-stroke diagram illustrating the load transmitted by the bumper assembly in the SOT to the vehicle's frame (in this case, frame FR). The horizontal axis, stroke, indicates the barrier's penetration position over time during a collision, and the vertical axis, load, indicates the reaction force of frame FR. As can be seen from Figure 6, the bumper assembly 100A in the embodiment transmits the load more efficiently to the rear than the bumper assembly 200 in the comparative example.

[0038] The load transmission members of the bumper assembly according to embodiments of the present invention can be modified in various ways. Schematic cross-sectional views of other bumper assemblies 100B, 100C, and 100D according to embodiments of the present invention are shown in Figures 7A, 7B, and 7C.

[0039] The load transmission member 30B of the bumper assembly 100B shown in Figure 7A has a plate-shaped portion 32B including a flat portion 32a1 and a convex portion 34. The convex portion 34 is the same as the convex portion 34 of the load transmission member 30A of the bumper assembly 100A. The plate-shaped portion 32B differs from the load transmission member 30A in that the flat portion 32a1 of the plate-shaped portion 32B overlaps with the entire energy absorption member 20 in the vehicle width direction. In this way, by having a flat portion 32a1 that overlaps with the entire energy absorption member 20, the load transmission member 30B can efficiently transmit the load to the vehicle frame FR.

[0040] The load transmission member 30C of the bumper assembly 100C shown in Figure 7B has a plate-shaped portion 32C and a convex portion 34. The convex portion 34 is the same as the convex portion 34 of the load transmission member 30A of the bumper assembly 100A. The plate-shaped portion 32C differs from the load transmission member 30A in that it has a portion 32c that extends outward in the vehicle width direction more than the third portion 34c. Because the plate-shaped portion 32C has portion 32c, the connection point to the beam 10 can be extended outward in the vehicle width direction. In addition, even if the barrier BR shifts outward in the vehicle width direction during a collision, the load can be efficiently transmitted to the vehicle body frame FR.

[0041] The load transmission member 30D of the bumper assembly 100D shown in Figure 7C has a plate-shaped portion 32D and a convex portion 34D. The plate-shaped portion 32D has a portion 32c that extends outward in the vehicle width direction beyond the third portion 34c, and the convex portion 34D has a fourth portion 34d that forms a through hole 30h2 with the portion 32c and the third portion 34c, thus differing from the load transmission member 30A. The load transmission member 30D can transmit energy to the energy absorption member 20 more efficiently than the load transmission member 30A, and can also absorb energy.

[0042] (Manufacturing method) The beam can be formed by extrusion molding using, for example, 6000 series (Al-Mg-Si) or 7000 series (Al-Zn-Mg) aluminum alloys. The energy absorbing member can be formed by extrusion molding using, for example, 6000 series aluminum alloys. The load transmission member can be formed by extrusion molding using, for example, 6000 series aluminum alloys. The plate can be formed by extrusion molding and rolling using, for example, 5000 series (Al-Mg) or 6000 series aluminum alloys. [Industrial applicability]

[0043] The bumper assembly according to the embodiment of the present invention can improve safety in SOT (State-of-the-Art) situations. [Explanation of Symbols]

[0044] 10 beams 10g recess (groove) 20 Energy absorbing member 30, 30A Load transmission member 40 plates 40p Peripheral area 40h through hole 20t1, 20t2 cylinder part

Claims

1. A bumper assembly that is attached to the front of a vehicle, In the state in which it is attached to the aforementioned vehicle, A beam extending in the width direction of the vehicle, An energy absorbing member (stay) partially joined to the rear surface of the beam, A load transmission member is located between the position of the beam at which the barrier collides in the SOT (Small Overlap Test) and the energy absorbing member, and is joined to the rear surface of the beam so as to overlap with at least a portion of the energy absorbing member in the vehicle width direction. It has, The load transmission member is In a cross-section parallel to the horizontal plane, a plate-like portion includes a flat plate portion that extends along the beam and overlaps with at least a portion of the energy absorbing member in the vehicle width direction, From the plate-shaped portion, a convex portion protrudes into the space between the rear surface of the beam and the energy absorbing member. It has, The rear surface of the beam has a recess, The plate-shaped portion of the load transmission member is fitted into the recess. Bumper assembly.

2. The vehicle further has a plate that is joined to the frame of the aforementioned vehicle, The energy absorbing member is bonded to the plate, The plate has a peripheral portion that protrudes from the energy absorbing member in the vehicle width direction, In the state in which it is attached to the aforementioned vehicle, The bumper assembly according to claim 1, wherein the convex portion of the load transmission member is located in the space between the rear surface of the beam, the energy absorbing member, and the plane extending from the plate, in a cross-section parallel to the horizontal plane.

3. The aforementioned convex portion is, in SOT, The bumper assembly according to claim 2, having a first portion that contacts the peripheral portion of the plate.

4. The aforementioned convex portion is, in SOT, The bumper assembly according to claim 3, further comprising a second portion that contacts the side surface of the energy absorbing member perpendicular to the plate.

5. The aforementioned convex portion is, in SOT, The bumper assembly according to claim 4, further comprising a third portion that, in a cross-section parallel to the horizontal plane, is substantially parallel to a line connecting the position of the beam that the barrier collides with and the intersection point of the plate and the side surface of the energy absorbing member.

6. The bumper assembly according to any one of claims 1 to 5, wherein the energy absorbing member has a plurality of cylindrical portions extending in the longitudinal direction of the vehicle.

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