JP5102648B2 - Bumper structure for vehicles - Google Patents

Description

  The present invention relates to a vehicle bumper structure that is particularly excellent in energy absorption characteristics in barrier and offset collisions and is lightweight, and relates to a bumper structure in which a bumper reinforcement is made of an aluminum alloy.

  Bumper reinforcements (also called bumper reinforcements or bumper armatures) as strength reinforcements are provided inside the bumpers attached to the front end (front) and rear end (rear) of automobile bodies. .

  As is well known, the bumper reinforcing member is disposed between the bumper and the vehicle body so as to extend in a substantially horizontal direction with respect to the vehicle body and in parallel with the vehicle width direction. And as for such a bumper reinforcement, in the shape of the longitudinal direction, various shapes are selected according to the design of an automobile body or a bumper.

  The bumper reinforcements are attached to the vehicle body by being connected to vehicle body frames (vehicle body members) of a skeleton member in the vehicle longitudinal direction such as a front side member and a rear side member. The bumper reinforcement is fixed to the vehicle body at the front or rear side member front or rear end of the vehicle body directly or via a support member (vehicle body connection member) from the rear surface such as a bumper stay.

  As is well known, the bumper reinforcing member constitutes an energy absorbing member for a vehicle body against a collision from the front or the rear of the vehicle body or a collision from the front or the rear between the bumper and the vehicle body. Therefore, the bumper reinforcement as the energy absorption member for the vehicle body is subjected to the collision energy applied from the front of the bumper reinforcement due to the collision of the vehicle body, and its own bending deformation and crushing deformation in the vehicle longitudinal direction (substantially horizontal cross-sectional direction). The ability to absorb and protect the vehicle body by (crushing) is required.

  In recent years, parts used in automobiles have become more demanding for weight reduction of the vehicle body, and the bumper reinforcement and bumper stay are no exception. For this reason, in place of conventionally used steel materials, extruded hollow shapes made of high-strength aluminum alloys, high tension materials, and the like are increasingly used. In particular, aluminum extruded profiles have the advantage that a closed cross-sectional structure can be obtained without joining, and their application to lightweight, high-strength bumper reinforcements is increasing.

  On the other hand, more excellent characteristics are required for safety in a vehicle body collision, and a performance for protecting a vehicle body is required even in a high-speed collision as compared with the conventional case. For this purpose, it is desired that the maximum load at the time of absorbing the energy of the bumper reinforcing material or the stay is as low as possible without damaging the vehicle body, and the energy can be absorbed with a shorter stroke. That is, a bumper structure that is lightweight and has high energy absorption efficiency is desired.

  In the case of a general bumper structure, the load required for bending deformation of the bumper reinforcing material is much smaller than the crushing load in the vicinity of the stay of the bumper reinforcing material itself and the crushing load of the stay. For this reason, at the time of a vehicle collision, the bumper reinforcing material is first bent and deformed, and then the reinforcing material or the stay is crushed at the portion directly above the stay.

  The structure having the best energy absorption efficiency upon collision—a structure in which the energy absorption stroke is shortened below a predetermined load—is a structure in which the deformation load at the time of collision is substantially constant until the end of deformation. That is, it is desirable that the load required for the bending deformation of the bumper reinforcing material is substantially equal to the crushing deformation load of the reinforcing material or stay generated in the latter half of the collision.

  The simplest method is to improve the bending deformation strength of the bumper reinforcement itself. However, since it is extremely difficult to increase the strength of the material, it is necessary to increase the outer cross-sectional dimension and the wall thickness. However, when such measures are taken in an extruded aluminum material having a constant cross section in the longitudinal direction, there is a problem that the cross-sectional area increases over the entire longitudinal direction and the weight increases significantly.

  As a conventional technique for improving the bending deformation strength of the bumper reinforcing material, there is a method of improving the deformation strength by improving the bumper and stay coupling structure (see Patent Documents 1 to 4). In other words, in a general bumper structure, the flange on the back side of the bumper reinforcement is connected to the stay, but if the flange on the collision side is also connected at the same time, the rotational deformation of the bumper reinforcement just above the stay will occur. It becomes difficult to occur and the deformation strength increases.

  However, these bumper stay coupling structures are structures in which a part of the stay is inserted into the space in the cross section of the bumper reinforcing material from the end side of the bumper reinforcing material. That is, there is a problem that the application is difficult only when the stay coupling portion is close to the end portion of the bumper reinforcement, and the stay coupling portion cannot be applied when the stay coupling position is closer to the center than the bumper reinforcement. In addition, if a middle rib is provided in the closed cross-section space to strengthen the bumper reinforcement, measures such as dividing the stay or cutting the middle rib are necessary to avoid this middle rib. Become.

  In general automobile design, when the vehicle body is viewed in plan, the center of the vehicle body has a convex shape in the vehicle front-rear direction. For this reason, as a representative shape of the bumper reinforcing material, there are a curved bumper reinforcing material that is curved in a convex shape with respect to the outside of the vehicle body, a center substantially parallel to the vehicle width direction, and both end portions. An end-bending-type bumper reinforcing material is generally used, which is bent to the vehicle body side. The stay coupling portion is closer to the end than the center of the bumper reinforcement, and the stay tip has a shape that is inclined in accordance with the shape of the bumper reinforcement back when viewed in plan.

  In such a structure, when a collision load is input near the center of the bumper, the load is input intensively to the inside portion of the vehicle body at the tip of the stay. For this reason, the vehicle body inner wall of the stay or the bumper reinforcing material directly above this tends to be locally deformed, resulting in a problem that the deformation load tends to decrease. In view of this, a proposal has been made to press the bumper reinforcing material to increase the cross-sectional outer dimension in the vicinity of the stay and to make the stay mounting portion on the back surface substantially parallel to the vehicle body width direction (Patent Document 5). , 6).

  Furthermore, from the viewpoint of increasing the amount of energy absorbed at the time of collision, it is desirable to provide an energy absorbing portion on the collision surface side of the stay in the vehicle longitudinal direction so as to increase the stroke for absorbing energy at the time of collision. Several proposals for structures having such an energy absorbing portion have been proposed (see Patent Documents 7 to 9). These are provided with an energy absorbing member composed of a separate part from the stay on the front surface of the bumper reinforcing material, and there is a problem that the cost increases due to an increase in the number of parts and an increase in the number of joints.

JP 2006-1449 (FIGS. 10 and 11) JP 2005-205991 (Fig. 1, Fig. 2, Fig. 3) JP 2005-104235 A (Fig. 1) Japanese Unexamined Patent Publication No. 2005-67527 (Fig. 1) JP 2001-199292 JP 2002-67842 A JP 2006-273056 A JP 2003-191806 JP Japanese Patent Laid-Open No. 2003-220909

  In the case of a bumper reinforcing material that undergoes variable cross-section processing as in Patent Documents 5 and 6, it is necessary to extend the material to some extent. For this reason, it is difficult to process with T5 tempered material of 6000 series or 7000 series, which is generally used as a bumper reinforcing material. In order to achieve both the required strength and workability as a product, T1 It is necessary to heat-treat the T5 tempered material after processing in the state of the tempered material. That is, it can be said that the addition of the press process accompanying the change cross section processing and the cost increase accompanying the heat treatment after the processing are inevitable. Furthermore, in bumper reinforcement materials for automobiles, from the viewpoint of ensuring collision performance and reducing the weight of parts, the bumper reinforcement material is often provided with a medium rib. When the cross-section processing is performed, the middle rib is likely to be broken or buckled, which causes a problem that it is difficult to apply.

  An object of the present invention is to provide a vehicle bumper structure having high energy absorption efficiency at the time of a vehicle body collision, and further, a lightweight vehicle bumper structure that can be produced at low cost without increasing the number of parts. Provide the body.

  In order to achieve this object, the vehicle bumper structure according to claim 1 of the present invention employs an aluminum alloy bumper reinforcing material and an aluminum alloy extruded shape bonded to both ends of the bumper reinforcing material. In the vehicle bumper structure comprising the material stay, the bumper reinforcing member has a vehicle body width direction parallel portion substantially parallel to the vehicle body width direction at a joint portion with the stay when the bumper structure is viewed in plan. At the same time, the central portion in the longitudinal direction has a protruding portion that protrudes toward the outer side of the vehicle body with respect to the stay joint portions on both ends.

Meanwhile, the stay is a front flange surrounding the side sectional outer periphery of the bumper reinforcement in a substantially annular rear flange, have a opening consisting of a web, with are joined through said bumper reinforcement to the opening A fixing flange is integrally provided on the web extending in the vehicle body inner direction, and the web is joined to the side member via the fixing flange.

  The vehicle bumper structure according to claim 2 of the present invention employs the energy absorbing portion in which the stay protrudes toward the collision surface in the vehicle body outer direction in the vehicle bumper structure according to claim 1. It is characterized by having.

  The vehicle bumper structure according to claim 3 of the present invention employs the vehicle bumper structure according to claim 2, wherein the energy absorbing portion has a closed cross-sectional structure having a hollow portion. It is a feature.

  According to the bumper structure for a vehicle according to claim 1 of the present invention, the bumper reinforcing member is parallel to the width direction of the vehicle body substantially parallel to the width direction of the vehicle body when the bumper structure is viewed in plan. Part. As a result, the joint shape of the stay and the joint shape of the side member are parallel to each other. For this reason, when the collision load from the center of the bumper reinforcement is input to the stay, the load concentration on the stay joint inside the vehicle body is alleviated, and the local collapse of the bumper reinforcement in the initial stage of the collision is reduced. Bending deformation strength increases.

Further, the stay is a side cross-sectional outer bumper reinforcement has an opening winding rather take a substantially annular, is coupled through said bumper reinforcement to the opening. For this reason, the substantially annular portion of the stay constrains the deformation of the bumper reinforcing material on the impact surface side of the bumper, making it possible to more firmly couple with the bumper reinforcing material, and the bending deformation strength of the bumper reinforcing material at the initial stage of the collision increases. To do. The substantially annular portion of the stay only comes into contact when the bumper reinforcement is deformed, and restrains the deformation.

  For this reason, the stay and the bumper reinforcing material may be combined with some part of the front flange, the rear flange, and the web of the bumper reinforcing material. In addition, it can be said that it is more preferable to couple the bumper reinforcing material at the two locations of the rear flange and the front flange with the stay, because it is possible to prevent the bumper reinforcing material flange from sliding in the vehicle body width direction at the time of collision.

  Further, in this bumper structure, when the bumper reinforcement just above the stay is crushed, the web connecting the front flange and the back flange of the stay is also crushed and deformed at the same time. is there. That is, the bending strength and crushing strength of the bumper reinforcing material can be improved without increasing the thickness of the bumper reinforcing material itself, and the vehicle bumper structure can be further reduced in weight.

  This stay can be easily obtained simply by cutting vertically after extrusion, using an aluminum extruded shape extruded in the vehicle body width direction, and can be manufactured with good yield and low cost. is there.

  The stay can be easily attached by inserting the end of the bumper reinforcing material into the opening of the stay and joining it to the bumper reinforcing material. Further, the cross-sectional shape of the stay opening and the outer surface of the bumper reinforcing material does not need to be completely matched, and a part of the opening used for joining with the bumper reinforcing material matches the outer dimension of the bumper reinforcing material, and A bumper reinforcement may be inserted into the opening.

  Furthermore, the side cross-sectional shape of this stay is the side cross-section of the shape of the connecting portion that connects the fixed flange used to join the side member on the back of the bumper reinforcement and the back of the bumper reinforcement. It is possible to conveniently select the required stay crushing load such as a cross section. Such a stay structure can be easily applied to, for example, a bumper structure in which a plurality of middle ribs for preventing buckling are provided, regardless of the side cross-sectional shape of the bumper reinforcement.

  The stay-bumper reinforcing member may be joined by bolt joining, or may be conveniently selected from fusion welding such as MIG and TIG, friction stir welding, and SPR. Further, for the purpose of positioning at the time of stay attachment and further improvement of the coupling rigidity, a fitting portion may be provided between them.

  Furthermore, in the vehicle bumper structure according to claim 2 of the present invention, it is further preferable that the stay has an energy absorbing portion protruding toward the collision surface in the vehicle body outer side direction. The bumper structure of the present invention can be manufactured integrally with the stay, and can be produced at a lower cost, compared to the conventional energy absorbing member configured as a separate part from the stay on the front surface of the bumper reinforcement. There is an advantage.

  In the structure of the present invention, the energy absorbing portion is provided so as to protrude toward the collision surface immediately above the stay. For this reason, the timing at which the load is transmitted at the time of a collision is accelerated, and the energy absorption stroke can be lengthened, that is, the energy absorption amount can be increased.

  Furthermore, in this structure, the effect that the bending strength itself of the bumper-reinforcing material is improved as compared with a bumper reinforcing material structure in which no energy absorbing portion is provided. This is because, during a collision, the bumper reinforcement is often the earliest load input to the central part of the bumper reinforcement protruding to the collision surface side, and this part is deformed so as to bend and deform inside the vehicle. This is because the input of the collision load to the energy absorbing portion works to suppress the bending deformation of the central portion of the bumper reinforcing member toward the inner side of the vehicle body (the jumping deformation toward the collision surface on the end side).

  And according to the bumper structure for vehicles concerning Claim 3 of the present invention, it is preferred that the section of the energy absorption part is a closed section structure which has a hollow part. When the energy absorbing portion has an open cross-sectional structure, the cross-sectional open deformation easily occurs at the time of collision, so that the amount of energy absorption cannot be expected so much. It should be noted that the energy absorbing portion having the closed cross-sectional structure can be easily provided integrally during the extrusion process as described above, and the cross-sectional shape is convenient depending on the vehicle design and the required amount of energy absorption. Selected. The energy absorbing portion is integrally provided at the time of extrusion, but the end portion side of the energy absorbing portion may be pressed so that it can be arranged on the collision surface side as much as possible in accordance with the vehicle design in plan view.

  First, the vehicle bumper structure according to the first embodiment of the present invention will be described below with reference to FIGS. 1 is a schematic plan view of a left half of a vehicle bumper structure according to Embodiment 1 of the present invention, and FIG. 2 is an enlarged side sectional view taken along the line XX in FIG. . 3 and 4 are side sectional views showing other examples of the vehicle bumper structure according to Embodiment 1 of the present invention.

The vehicle bumper structure according to Embodiment 1 of the present invention is as shown in the attached FIGS.
An aluminum alloy bumper reinforcing material (hereinafter simply referred to as a bumper reinforcing material) 1 and an aluminum alloy extruded shape material stay (hereinafter simply referred to as a stay) 2 joined to both ends of the bumper reinforcing material.

  In such a vehicle bumper structure, the bumper reinforcing member 1 has a vehicle body width direction parallel portion 4 substantially parallel to the vehicle body width direction at the joint portion 3 with the stay 2 when the bumper structure is viewed in plan. The center part of the longitudinal direction has the protrusion part 5 which protrudes in the vehicle body outer side direction with respect to the stay junction part 3 of both ends. The vehicle body width direction parallel part 4 may have a parallel part only in the joint part 3 with the stay 2 of the bumper reinforcement 1, but may also have a parallel part in the bumper reinforcement 1 near the joint part of the stay 2. good.

  On the other hand, the stay 2 surrounds the outer periphery of the side section in an annular shape, a web 21 joined to the upper surface 11 and the lower surface 12 of the bumper reinforcement 1, a front flange 22 joined to the front surface 13 of the bumper reinforcement 1, and A back flange 23 joined to the back surface 14 of the bumper reinforcement 1 is provided. A fixing flange 24 is integrally provided on the web 21 extending in the vehicle body inner direction, and is joined to the side member via the fixing flange 24 by a bolt 6 or the like as will be described later. Reference numeral 15 denotes a rib for reinforcing the bumper reinforcing material 1 in the collision direction, and reference numeral 25 denotes a rib for reinforcing the stay 2.

  Such a reinforcing structure of the stay 2 does not necessarily need to be a single rib parallel to the collision direction, and does not stick to the shape or configuration. That is, as shown in FIG. 3 (a), the ribs 25a are inclined with respect to the collision direction, or as shown in FIG. 3 (b), the ribs 25a are arranged in parallel with the collision direction. It is good also as the some rib 25b.

  Furthermore, the stay 2 formed around the outer periphery of the side cross section of the bumper reinforcing material 1 does not need to surround the entire outer periphery of the side cross section. For example, as shown in FIG. A portion of the front flange 22 joined to the front surface has a discontinuous portion 22a so as to surround a substantially annular shape, or protrudes vertically from the front surface 13 of the bumper reinforcement 1 as shown in FIG. 3 (c). The overhanging portion 13a can be formed, and an overhanging flange 22b can be integrally provided at the front end of the web 21 constituting the stay 2, and the overhanging flange 22b can be joined to the overhanging portion 13a from the back side.

  3C, the extension flange 22b of the stay 2 and the extension portion 13a of the bumper reinforcement 1 are joined at this position in order to restrain deformation of the front surface 13 when the bumper reinforcement 1 collides. It is essential to do. When the impact surface side flange (front flange 22) of the stay 2 exists so as to surround the impact surface side (front surface 13) of the bumper reinforcement 1 as shown in FIGS. The stay 2 can restrain the deformation of the bumper reinforcing member 1 even if it is not necessary, and it is not always necessary to join at the collision surface side flange (front flange 22).

  Furthermore, as shown in FIG. 4 (a), a recess 13b is provided on the front surface 13 of the bumper reinforcement 1, and a protrusion 22c that can be fitted into the recess 13b is formed on the front flange 22 of the stay 2. The fitting portion 7 can be formed and joined by the concave portion 13b formed in the bumper reinforcing member 1 and the convex portion 22c formed in the stay 2. Such a fitting portion 7 is not necessarily formed between the front surface 13 of the bumper reinforcement 1 and the front flange 22 of the stay, but between the upper and lower surfaces 11 and 12 and the web 21 or between the rear surface 14 and the rear flange 23. Each may be formed.

  On the other hand, the side cross-sectional outer shape of the bumper reinforcing member 1 is not limited to a rectangular shape, and any shape can be selected. For example, as shown in FIG. 4B, the rear surface 14 and a part of the upper and lower surfaces 11 and 12 may have a retreat portion 1a that retreats inward. In the case of such a bumper reinforcement 1, the side cross-sectional shape of the stay 2 that surrounds the bumper reinforcement 1 does not necessarily need to be completely surrounded by the outer periphery of the bumper reinforcement 1, and is joined to the bumper reinforcement 1. There may be a non-joined portion 2a that is not to be provided.

  Next, a method of joining the bumper reinforcing member 1 and the stay 2 formed as described above will be described with reference to the attached FIG. 5 taking the bumper reinforcing member 1 and the stay 2 shown in FIG. 2 as an example. FIG. 5 is a perspective view of a stay coupling portion for explaining a method of joining the bumper reinforcing member and the stay according to the first embodiment of the present invention.

  First, the openings formed in the side cross section by the web 21 of the stay 2, the front flange 22 and the rear flange 23 are inserted into both end portions of the bumper reinforcement 1, and are arranged at predetermined positions of the vehicle body width direction parallel portion 4. Next, from the front flange 22 of the stay 2 and the work hole 30 formed in the front surface 13 of the bumper reinforcement 1, the bolt hole 31 formed in the rear surface 14 of the bumper reinforcement 1 and the rear flange 23 of the stay 2 is formed. After inserting bolts (not shown) in the bolt insertion direction A, nuts are screwed onto the bolts from the rear side of the rear flange 23 to connect the rear surface 14 of the bumper reinforcement 1 and the rear flange 23 of the stay 2. Conclude.

  Further, after inserting bolts (not shown) from the front flange 22 of the stay 2 and the bolt holes 32 formed in the front surface 13 of the bumper reinforcing member 1, nuts are inserted into these bolts from the rear of the front surface 13 of the bumper reinforcing member 1. The bumper reinforcing material 1 and the stay 2 are joined by screwing and fastening the front surface 13 of the bumper reinforcing material 1 and the front flange 22 of the stay 2. The vehicular bumper structure joined in this way is fixed to a vehicle side member (not shown) by inserting a bolt into a bolt hole 33 provided in the fixing flange 24 of the stay 2.

  As described above, according to the bumper structure for a vehicle according to the first embodiment of the present invention, when the bumper structure is viewed in plan, the bumper reinforcement body 1 is substantially in the vehicle width direction at the joint portion 3 with the stay 2. Since the parallel vehicle body width direction parallel portion 4 is provided, when a collision load from the center of the bumper reinforcement is input to the stay 2, the load concentration on the stay joint 3 inside the vehicle body is alleviated, and the bumper reinforcement in the initial stage of the collision The bending deformation strength of 1 increases.

  Further, since the stay 2 is joined to the bumper reinforcing material 1 by surrounding the outer periphery of the bumper reinforcing material 1 in a substantially annular shape, the stay 2 is further subjected to rotational deformation in the vicinity of the stay coupling portion 3 due to bending deformation of the bumper reinforcing material 1. The web 21 connecting the front flange 22 and the rear flange 23 of the stay 2 simultaneously collapses and deforms at the same time when the bumper reinforcing material 1 of the stay connecting portion is crushed and deformed. It is possible to improve the crushing strength and reduce the weight of the bumper structure.

  Next, a vehicle bumper structure according to Embodiment 2 of the present invention will be described below with reference to FIG. FIG. 6 is a side sectional view showing a vehicle bumper structure according to Embodiment 2 of the present invention. It should be noted that the second embodiment of the present invention differs from the first embodiment in that there is a difference in the presence or absence of the energy absorbing portion of the stay, and the rest of the configuration is exactly the same. The explanation shall be stopped.

  In Embodiment 1 of the present invention, the stay 2 includes a web 21, a front flange 22, and a rear flange 23 that surround the outer periphery of the bumper reinforcement 1 in a substantially annular shape and are joined to the bumper reinforcement 1. In addition, a fixing flange 24 is integrally provided on the web 21 extending in the vehicle body inner direction, and the web 21 is joined to the side member via the fixing flange 24.

  On the other hand, in the second embodiment of the present invention, in addition to the above-described configuration, the stay 2 has an energy absorbing portion 8 that protrudes toward the collision surface in the vehicle outer side direction. That is, the energy absorbing portion 8 constitutes the energy absorbing portion 8 further on the collision surface side of the front flange 22 constituting the stay 2 as shown in FIG.

  Further, the energy absorbing portion 8 has a rectangular cross section as shown in FIG. 6A, a semicircular cross section as shown in FIG. 6B, or a reinforcing rib 28 as shown in FIG. 6C. It may be provided.

  The energy absorbing portion 8 of the vehicle bumper structure according to the second embodiment of the present invention needs to have at least one or more hollow portions 8a. The cross-sectional shape of the energy absorbing portion 8 is the vehicle design and the required energy absorption. Conveniently selected by quantity. Further, the energy absorbing portion 8 can be integrally formed by extrusion molding, and the stay 2 for joining the energy absorbing portion 8 and the bumper reinforcing material 1 to the vehicle body can be obtained without increasing the number of parts. Can do.

  As described above, according to the vehicle bumper structure according to the second embodiment of the present invention, the stay 2 has the energy absorbing portion 8 that protrudes toward the collision surface in the vehicle body outer side direction. The bumper structure of the present invention can be manufactured integrally with the stay 2 with respect to the conventional energy absorbing member configured as a separate part from the stay 2 in FIG. 13, and can be produced at a lower cost.

<Example>
Next, the bumper structure according to the first embodiment of the present invention having the structure shown in FIGS. 1 and 2 and the same configuration and dimensions as the bumper structure are shown. The stay 2 shown in FIG. The bumper structure according to the second embodiment of the present invention in which the energy absorbing portion 8 as shown in FIG. 5A is provided, and the cross-sectional shape on the back side of the bumper reinforcing material 1 and the bumper reinforcing material 1 of the stay 2 are illustrated. 1 is the same as the structure shown in FIG. 1, and the bumper structure according to the conventional example in which the stay 2 is connected to the collision back side of the bumper reinforcing material 1 (no additional energy absorbing component on the collision surface side) An example of simulation in the case of acting will be described below with reference to FIGS.

  FIG. 7 is a diagram schematically showing a simulation result of the load with respect to the stroke of the collision object, and FIG. 8 is a schematic diagram for explaining the effect of the bumper structure in which the energy absorbing portion is provided in the stay.

  First, the conventional example will be described. When a collision object collides with the central part of the bumper structure in the vehicle width direction (stroke = 0), the collision object moves forward and the load increases as the stroke increases. When the bending deformation starts beyond the elastic deformation region of the bumper reinforcement, the stroke proceeds, but the load tends to decrease. Further, when the stroke progresses and the collision object contacts the bumper reinforcing material immediately above the stay (stroke = S1), the bumper reinforcing material starts to be crushed and the load increases as the stroke increases again. Finally, the stay provided on the rear side of the collision is also crushed and deformed, and finally the bumper reinforcement body is crushed.

  On the other hand, in the case of the bumper reinforcing body (without the energy absorbing portion) according to Embodiment 1 of the present invention, the bumper reinforcing member 1 has the vehicle body width direction parallel portion 4 at the joint portion 3 with the stay 2. Since the load concentration on the stay joint 3 on the inner side of the vehicle body is alleviated and the bending deformation strength of the bumper reinforcing material 1 at the initial stage of the collision is increased, the load at the start of the bending deformation of the reinforcing material increases.

  In addition, since the stay 2 is joined to the bumper reinforcing material 1 by surrounding the outer side of the bumper reinforcing material 1 in a substantially annular shape, the rotation deformation in the vicinity of the stay joint portion 3 accompanying the bending deformation of the bumper reinforcing material 1 is further strengthened. Can be restrained. Thereby, the load drop after reaching the maximum load at the start of bending deformation is also smaller than in the conventional example.

  Furthermore, since the stay 2 surrounds the bumper reinforcing material 1 in a substantially annular shape, the crushing strength of the bumper reinforcing material 1 itself is increased. Therefore, before the crushing deformation of the bumper reinforcing material 1 of the stay joint 3, The back side of the bumper reinforcing material 1 of the web 21 of the stay 2 is first crushed and deformed. After the stay 2 is completely crushed, the bumper reinforcing material 1 is crushed and deformed, and the deformation load at that time becomes higher than that of the conventional example.

  When the energy absorption amount is equal to that of the conventional example, the absorption of the collision energy is completed before the crushing deformation of the bumper reinforcing material 1 occurs, and the energy can be absorbed with a shorter collision stroke than the conventional example. In other words, even if the thickness of the bumper reinforcing material 1 is further reduced, it can be said that the energy absorption performance equivalent to the conventional one can be obtained. The weight reduction effect by reducing the thickness of the bumper reinforcement 1 extending in the vehicle body width direction is more effective than the weight increase by providing the substantially annular portion in the stay portion. Weight can be reduced.

  On the other hand, in the case of the bumper reinforcing body (with an energy absorbing portion) according to Embodiment 2 of the present invention, as shown in FIG. 8, the stroke of the collision object is advanced as compared with the bumper reinforcing body of Embodiment 1 above. When the stroke S2 in which a load is directly input to the energy absorbing portion 8 of the stay 2 is reached, the load increases due to the crushing deformation of the energy absorbing portion 8, and against the rotational deformation (arrow B) of the bumper structure. Since the load input 34 is generated, the bending deformation strength of the bumper reinforcing material 1 itself also increases rapidly.

  Thereafter, as in the first embodiment, the deformation of the back side of the bumper reinforcement material of the web 21 of the stay 2 and the crushing deformation of the bumper reinforcement material 1 occur. However, compared with the first embodiment, the energy can be efficiently consumed at the initial stage of the collision. Since absorption is possible, it can be said that the energy absorption stroke can be further shortened. The weight reduction effect obtained by reducing the thickness of the bumper reinforcing member 1 extending in the vehicle body width direction is more effective than the weight increase obtained by adding the stay 2 and the energy absorbing portion 8. Can reduce the weight.

  As described above, according to the vehicle bumper structure according to the present invention, when the bumper structure is viewed in plan, the bumper reinforcing body is substantially parallel to the vehicle body width direction at the joint portion with the stay. Therefore, when a collision load from the center of the bumper reinforcement is input to the stay, the load concentration on the stay joint inside the vehicle body is alleviated, and the bending deformation strength of the bumper reinforcement in the initial stage of the collision increases. At the same time, an increase in load due to the start of crushing deformation of the energy absorbing portion is also written, which can be said to be more desirable because energy can be efficiently absorbed at the beginning of the collision.

  In addition, since the stay includes an energy absorbing portion that protrudes toward the collision surface in the vehicle body outer side direction, a conventional energy absorbing member configured as a separate part from the stay on the front surface of the bumper reinforcing material is used. The bumper structure can be manufactured integrally with the stay, and can be produced at a lower cost.

It is the typical top view which planarly viewed the left half of the bumper structure for vehicles concerning Embodiment 1 of the present invention. It is a sectional side view which expands and shows the arrow XX of FIG. It is the sectional side view which showed the other example of the aspect of the bumper structure for vehicles which concerns on Embodiment 1 of this invention. It is the sectional side view which showed the other example of the aspect of the bumper structure for vehicles which concerns on Embodiment 1 of this invention. It is a perspective view of the stay coupling | bond part for demonstrating the method to join the bumper structure for vehicles which concerns on Embodiment 1 of this invention to a side member. It is a sectional side view which shows the bumper structure for vehicles which concerns on Embodiment 2 of this invention. It is the figure which showed typically the simulation result of the load with respect to the stroke of a collision object. It is a schematic diagram for demonstrating the effect of the bumper structure in which the energy absorption part was provided in the stay.

Explanation of symbols

A: Bolt insertion direction,
1: Bumper reinforcement 1a: Retreat part,
2: Stay, 2a: Non-joined part,
3: (stay) joint, 4: parallel to the vehicle body width direction, 5: protrusion
6: bolt, 7: fitting part,
8: Energy absorption part, 8a: Hollow part,
11: Upper surface, 12: Lower surface,
13: Front surface, 13a: Overhang portion, 13b: Recessed portion,
14: Back side, 15, 25, 25a, 25b, 28: Rib,
21: Web,
22: Front flange, 22a: Discontinuous part, 22b: Overhang flange, 22c: Convex part,
23: Back flange, 24: Fixed flange,
26, 26a: flange, 27: semi-cylindrical plate,
30: Work hole 31, 32, 33: Bolt hole 34: Load input

Claims (3)

In a vehicle bumper structure comprising an aluminum alloy bumper reinforcing material and an aluminum alloy extruded profile stay joined to both ends of the bumper reinforcing material, the bumper reinforcing material is a plan view of the bumper structure. In this case, the joint portion with the stay has a vehicle body width direction parallel portion substantially parallel to the vehicle body width direction, and a center portion in the longitudinal direction has a protruding portion that protrudes toward the vehicle body outer side with respect to the stay joint portions on both ends. Meanwhile, the stay is a front flange surrounding the side sectional outer periphery of the bumper reinforcement in a substantially annular rear flange, have a opening consisting of a web, with are joined through said bumper reinforcement to the opening A fixing flange is integrally provided on the web extending in the vehicle body inner direction, and is joined to the side member via the fixing flange. The vehicle bumper structure according to claim. The vehicle bumper structure according to claim 1, wherein the stay includes an energy absorbing portion that protrudes toward a collision surface in a vehicle body outer side direction. The vehicle bumper structure according to claim 2, wherein a side section of the energy absorbing portion is a closed section structure having a hollow portion.

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