JP2017007450A - Bumper reinforcement structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bumper reinforcement structure in which reinforcement plates are used for a body member to obtain predetermined flexural strength, but which can suppress weight increase as much as possible.SOLUTION: A bumper reinforcement structure 10 to be provided at a front or rear portion of a motor vehicle body includes: an elongated body member 14 having a hitting surface that receives the load upon a vehicle impact; and support structures for the motor vehicle body to receive the load applied on the body member 14. The body member 14 has a hat-shaped vertical section of which the rear side is opened. At least within the lateral range between the support structures, of the body member 14, strip reinforcement plates 20A, 20B formed separately from each other are disposed being spaced apart from each other, and fixed at upper and lower end portions respectively, of the opening of the hat-shaped vertical section.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a bumper reinforcement structure. In particular, the present invention relates to a bumper reinforcement structure that is provided at the front or rear of an automobile body and obtains a predetermined bending strength while suppressing an increase in weight.

  A bumper reinforcement structure provided at the front or rear of an automobile body has an elongated main body member disposed in the width direction of the automobile body and having a contact surface for receiving a load at the time of a vehicle collision, and the width direction of the main body member And a support structure for receiving a load acting on the main body member at the vehicle body.

  The body member of the bumper reinforcement structure is designed to satisfy a collision load (bending strength) required within a range in which a space provided for each vehicle type is determined.

  FIG. 10 and FIG. 11 show the longitudinal cross-sectional structure when the main body member 114 that has been conventionally employed is arranged at the front of the vehicle body based on the above design philosophy. Is the rear of the car body. A range X indicated by a virtual line indicates a space provided for each vehicle type. 10 and 11, the vertical cross-sectional shape of the main body member 114 is a hat-shaped cross-sectional shape with an opening on the rear side of the vehicle body. The upper side surface 124A and the lower side surface 124B are formed so as to spread rearward from the upper and lower ends of the front surface 122 that becomes a contact surface at the time of a vehicle collision, and flanges 126A and 126B are formed at the rear end toward the upper and lower sides of the vehicle body, respectively. Has been.

  FIG. 10 shows a case where the main body member 114 is arranged to have a wide front width Y as a contact surface in a given space range X. In the case of this arrangement configuration, since the contact surface Y can be widened, it is advantageous in the pendulum evaluation of the performance test and the pedestrian protection evaluation. However, since the rear of the main body member 114 is open, it is difficult to ensure a predetermined bending strength.

  FIG. 11 shows an arrangement in which the bending strength is improved by sacrificing the front width Y as a contact surface to solve the problem of bending strength in the arrangement of FIG. The arrangement configuration is such that the rear opening of the main body member 114 having a hat-shaped cross-sectional shape with an opening at the rear is closed with a reinforcing plate 120 to form a closed cross-sectional structure (see Patent Document 1 below). The reinforcing plate 120 is formed by extending flanges 126A and 126B at the open ends of the upper side surface 124A and the lower side surface 124B, and is fixed to the flanges 126A and 126B by spot welding 128. Bending strength can be improved by disposing the reinforcing plate 120 to have a closed cross-sectional shape. However, in the case of this arrangement configuration, there is a disadvantage that the front surface width Y that becomes the contact surface is reduced by the length of the flanges 126A and 126B of FIG.

JP 2012-110944 A

  According to the configuration in which the reinforcing plate 120 shown in FIG. 11 is disposed in the rear opening, the bending strength can be improved, but the reinforcing plate 120 is disposed over the entire rear opening. There is a problem that the weight increases accordingly.

  By the way, there is an improvement in fuel consumption as a problem of automobiles. In order to improve the fuel efficiency, it is an object to suppress the increase in the weight of each component of the automobile as much as possible.

  Thus, the present invention has been devised in view of the above points, and the problem to be solved by the present invention is to obtain a predetermined bending strength by using a reinforcing plate for the main body member of the bumper reinforcement structure. Even in this case, it is to suppress the weight increase as much as possible.

  In order to solve the above problems, the present invention takes the following means.

  The bumper reinforcement structure according to the present invention includes an elongated body member that is disposed in the width direction of the automobile body at the front or rear of the automobile body and has a contact surface that receives a load in the event of a vehicle collision, and the body member And a support structure for receiving a load acting on the main body member at both sides in the width direction. The main body member has a hat-shaped cross-sectional shape in which the inner side in the front-rear direction of the automobile body has a longitudinal cross-sectional shape, and the hat-shaped cross section is at least within a range in the width direction between support structures of the main body member. Each of the long plate-shaped reinforcing plates fixed to the upper and lower ends of the opening is formed as a separate member and arranged separately.

  According to the present invention described above, the reinforcing plate disposed in the vehicle body inner side opening portion of the hat-shaped cross-sectional shape of the main body member is disposed separately as a separate member at the upper and lower ends of the opening. For this reason, an increase in the weight of the reinforcing plate can be suppressed by an area that is spaced apart.

  Even when the reinforcing plate is arranged as a separate member at the upper and lower ends of the opening as described above, it is possible to ensure the same bending strength as in the arrangement configuration shown in FIG. This was confirmed by the results of analysis by the inventors as shown in FIG. The reason for the details will be described in an embodiment described later, but the main body member bends in the longitudinal direction with the support structure as a fulcrum due to a vehicle collision, but the reinforcing plate formed as a separate member also bends in the longitudinal direction accordingly. It will be. When the reinforcing plate bends in the longitudinal direction, a tensile force in the longitudinal direction is generated in the reinforcing plate, and a reaction force of this tensile force acts as a bending deformation suppression of the main body member and becomes a bending strength.

  According to the above-described means of the present invention, even when a predetermined bending strength is obtained by using a reinforcing plate for the body member of the bumper reinforcement structure, the reinforcing plate is separated as a separate member at the upper and lower end portions where the hat-shaped cross section is opened. Therefore, an increase in weight can be suppressed as much as possible.

It is the schematic which shows the schematic arrangement configuration of the bumper reinforcement structure of this embodiment. It is sectional drawing which shows the bumper reinforcement structure of 1st Embodiment. It is the perspective view which looked at the 1st embodiment of the above from back. It is sectional drawing which shows the bumper reinforcement structure of 2nd Embodiment. It is the perspective view which looked at the 2nd embodiment from the back. It is a perspective view which shows the analysis conditions of a bumper reinforcement structure, and shows the state before applying a load. It is a perspective view which shows the analysis condition of a bumper reinforcement structure, and shows the state after applying a load. It is a graph which shows the load and displacement curve of the result analyzed by the analysis conditions of the said FIG.6 and FIG.7. It is a comparison table | surface which compares and shows the numerical value obtained from the specification of the analysis conditions, and the analysis result. It is sectional drawing which shows the 1st arrangement configuration of a prior art example. It is sectional drawing which shows the 2nd arrangement configuration of a prior art example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, FIG. 1 shows an arrangement position of a bumper reinforcement structure 10 in an automobile. The bumper reinforcement structure 10 is usually arranged in the width direction with respect to the automobile body 12 at the front and rear of the automobile body 12. In FIG. 1, the front of the vehicle body 12 is indicated by an arrow F, and the rear is indicated by an arrow R. The bumper reinforcement structure 10 is an iron-based member and is formed of a long main body member 14 and a support structure 16. The support structure 16 is disposed at positions on both sides in the longitudinal direction of the main body member 14 (the width direction when viewed from the vehicle body 12), and supports a load such as a collision load acting on the main body member 14 by the vehicle body 12. Playing a role.

  A resin bumper 18 is disposed on the outer surface side of the main body member 14 so as to cover the main body member 14. The bumper 18 is disposed as the outermost surface of the bumper reinforcement structure 10 and is configured in consideration of appearance.

  Due to the arrangement as described above, a collision load at the time of a frontal collision or a rearal collision to the automobile is first received by the bumper 18 and supported by the main body member 14. The load acting on the main body member 14 is received by the automobile body 12 via the support structures 16 disposed on both sides of the main body member 14.

  2 and 3 show a first embodiment of the bumper reinforcement structure 10. In the following embodiments, the bumper reinforcement structure 10 disposed in the front portion of the automobile body 12 will be described as an example. A range X indicated by an imaginary line in FIG. 2 is an arrangement space of a bumper reinforcement structure determined for each vehicle type, and it is necessary to ensure rigidity (bending strength) in this space. In this embodiment, rigidity (bending strength) is ensured by a combined configuration of the main body member 14 and the reinforcing plate 20. Therefore, the main body member 14 and the reinforcing plate 20 are composed of iron-based members. The main body member 14 has a hat-shaped cross-sectional shape with an opening at the rear. Specifically, a front surface 22 that becomes a contact surface at the time of a vehicle collision, an upper side surface 24A and a lower side surface 24B formed so as to spread rearward from the upper and lower ends of the front surface 22, and the upper side surface 24A and the lower side surface 24B It consists of flanges 26A and 26B extending from the rear end toward the upper and lower parts of the vehicle body. In the drawings to be described later, F indicated by an arrow indicates the front, U indicates the upper side, D indicates the lower side, and the bumper reinforcement structure 10 disposed in the front portion is a reference.

  As shown in FIG. 2, the reinforcing plate 20 includes an upper reinforcing plate 20A disposed on the upper side and a lower reinforcing plate 20B disposed on the lower side. The reinforcing plates 20A and 20B have a flat plate shape and are formed of separate members. Preferably, the reinforcing plates 20A and 20B have the same shape, so that parts can be shared. One end surface portion in the longitudinal direction of each of the reinforcing plates 20A and 20B is disposed facing the rear surface of the flanges 26A and 26B, and is fixed by spot welding 28. The other end surface portion is disposed so as to extend in the direction of closing the opening. However, the tip of the other end surface portion is disposed as a separated position, and the rear portion of the body member 14 is open.

  The support structure 16 that supports the main body member 14 on the automobile body 12 is at a position indicated by a virtual line in FIG. 3. The positions are the positions on both sides of the main body member 14. The reinforcing plates 20A and 20B described above are disposed between the support structures 16 and 16 installed at both side positions, and the longitudinal positional relationship between the upper reinforcing plate 20A and the lower reinforcing plate 20B is as follows. It is the same position.

  As shown in FIGS. 2 and 3, the front surface 22, which is the contact surface Y of the main body member 14, is formed so as to have a recessed portion 23 at the center portion when viewed in the vertical direction and to extend in the longitudinal direction. . This is intended to improve the rigidity of the front face 22.

  The configuration of the first embodiment is different from the configuration shown in FIG. 11 described as the prior art only in the configuration of the reinforcing plates 20A and 20B, and the other configurations are the same. Therefore, as in the case of the conventional configuration shown in FIG. 11, the flanges 26A and 26B to which the reinforcing plates 20A and 20B are fixed by spot welding are required to have a length for welding and are fixed, and the front surface serving as the contact surface Y The width of 22 is narrowed accordingly.

  4 and 5 show a second embodiment of the bumper reinforcement structure 10. In the description of the second embodiment, parts that are substantially the same as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof may be omitted. The second embodiment is different from the first embodiment in the shape and arrangement configuration of the reinforcing plate 20. The upper reinforcing plate 20A and the lower reinforcing plate 20B are formed of separate members, and the longitudinal sectional shape is formed in an L shape. In this embodiment, the L-shaped bending angle is a right angle. In the second embodiment also, it is preferable that both reinforcing plates 20A and 20B have a shape that allows common parts.

  The upper reinforcing plate 20 </ b> A is disposed at the inner surface position on the opening side of the upper side surface 24 </ b> A and is fixed by spot welding 28. More specifically, one side of the L shape is disposed along the inner surface of the upper side surface 24 </ b> A and is fixed by spot welding 28. Since one side of the L shape is disposed and fixed on the inner surface of the upper side surface 24A, the other side of the L shape is located on the inner side of the opening end of the main body member 14, more specifically on the upper and lower sides of the opening end. It is extended and arranged toward the middle side. The disposition position of the other side extending inward is set so as not to exceed the opening end position of the main body member 14 having a hat-shaped cross section when viewed in the front-rear direction. That is, the arrangement does not exceed the rear line of the space range X. The arrangement of the lower reinforcing plate 20B is the same. The inner ends of the upper reinforcing plate 20A and the lower reinforcing plate 20B are spaced apart from each other.

  The lengths of the upper and lower flanges 26A and 26B formed by bending the opening end portions of the upper side surface 24A and the lower side surface 24B in opposite directions are not fixed by welding as in the first embodiment. Considering only securing the rigidity of the opening end, the length can be made shorter than that of the first embodiment. For this reason, the length of the longitudinal direction of the front surface 22 that becomes the contact surface Y can be increased by the amount that the lengths of the flanges 26A and 26B can be shortened. The wide formation of the contact surface Y of the front surface 22 in this manner is advantageous in pendulum evaluation and pedestrian protection evaluation in the performance test of the bumper reinforcement structure 10.

  6 and 7 show analysis conditions of the bumper reinforcement structure 10, FIG. 6 shows a state before a load is applied, and FIG. 7 shows a state after the load is applied. The main body member 14 is supported by disposing the support members 30 at both side positions where the support structure 16 is disposed, and a load is applied by the impactor 32 from above the central position of the main body member 14 to counteract the impactor 32. It measures force. Under the analysis conditions, the pitch between the support members 30 and 30 is 915 mm, and the impactor is forcibly displaced at 8.6 km / h. According to this analysis condition, when the impactor 32 is displaced from the state before the impactor 32 shown in FIG. 6 is displaced and a load is applied to the main body member 14, the impactor 32 causes the main body member to be loaded as shown in FIG. 14 is bent and deformed downward. The reaction force of the impactor 32 at the time of this deformation is measured.

  FIG. 8 is a load / displacement curve of the main body member 14 obtained as a result of analysis under the above analysis conditions. The analyzed form of the main body member 14 includes three types A, B, and C illustrated as “shape” in the comparison table of FIG. 9. A is the second embodiment shown in FIGS. 4 and 5, B is the prior art shown in FIG. 11, and C is the prior art shown in FIG. The three types of analysis results are compared and shown.

  The load / displacement curve shown in FIG. 8 shows the peak load at the displacement at which the bumper reinforcement structure 10 buckles as the displacement increases and the bumper reinforcement structure 10 buckles, and becomes the highest load. The load gradually decreases with the subsequent displacement. The bending load of the bumper reinforcement structure 10 is obtained by multiplying the peak load in this curve by L / 4 (L is the pitch between the support members 30 and 30). As shown in FIG. 9, the form C has a peak load of 19.8 kN and a bending strength of 4.5 kN, whereas the forms A and B both have a peak load of 22.5 kN and a bending strength of 5.1 kN. It is excellent. And about the reinforcement board mass efficiency which is the efficiency of the bending proof strength with respect to the mass increase by a reinforcement board, when the A form and B form which arrange | position the reinforcement boards 20 and 120 are compared, the B form of the closed cross-sectional shape which fully closes a rear surface is A type in which the reinforcing plate mass is 792 g and the reinforcing plate mass efficiency (N · m / g) is 64, whereas the reinforcing plate 20 is arranged while being spaced apart and partially opened. Is as efficient as 101 with a reinforcing plate mass of 504 g and a reinforcing plate mass efficiency (N · m / g) of 101. Even with the same bending strength, the A form has the effect of reducing the weight. The mass efficiency of the reinforcing plate is obtained from the bending strength / the mass of the reinforcing plate. In the analysis result shown in FIG. 9 described above, when comprehensively evaluated from both viewpoints of bending strength and weight reduction, it can be seen that the A form is superior to the B form and the C form. The same effects as those of the A form (second embodiment) can be obtained in the first embodiment shown in FIGS.

  In the bending strength evaluation of FIG. 9, the A form in which the reinforcing plates 20 are arranged apart from each other while arranging the reinforcing plates 20 is substantially the same as the B form in which the reinforcing plates 120 are closed and arranged in a cross-sectional shape. The present inventors thought that the evaluation was obtained for the following reason. Due to a vehicle collision, the main body member 14 between the support structures 16 and 16 bends in the longitudinal direction with the support structures 16 and 16 as fulcrums. Due to the bending of the main body member 14 in the longitudinal direction, the reinforcing plate 20 formed as a separate member and integrated with the main body member 14 is also bent in the longitudinal direction accordingly. When the reinforcing plate 20 bends in the longitudinal direction, a tensile force in the longitudinal direction is generated in the reinforcing plate 20, and a reaction force of this tensile force acts as a bending deformation suppression of the main body member 14 and becomes a bending strength. The present inventors recalled that the weight of the reinforcing plate 14 can be reduced by finding this phenomenon.

  While the present invention has been described with respect to specific embodiments, the present invention can be implemented in various other forms.

  For example, in the above-described embodiment, the reinforcing plate is arranged only between the support structures. However, if necessary, the reinforcing plate may be arranged beyond the support structure.

  In the above-described embodiment, the means for fixing the reinforcing plate to the main body member is welding. However, various fixing means such as adhesion, rivet fastening, and bolt fixing may be used.

  In the above-described embodiment, the concave shape is formed on the front surface. However, even if this concave shape is not provided, it may not be formed if a predetermined bending strength can be obtained.

  Further, the angle of the L-shaped reinforcing plate may be other than a right angle.

DESCRIPTION OF SYMBOLS 10 Bumper reinforcement structure 12 Automobile body 14 Main body member 16 Support structure 18 Bumper 20 Reinforcement plate 20A Upper reinforcement plate 20B Lower reinforcement plate 22 Front (contact surface Y)
23 Indented shape 24A Upper side surface 24B Lower side surface 26 Flange 26A Upper flange 26B Lower flange 28 Spot welding (welding)
30 Support member 32 Impactor

Claims (5)

An elongate body member that is disposed in the width direction of the car body at the front or rear of the car body and has a contact surface that receives a load in the event of a vehicle collision, and the body member at both longitudinal sides of the body member A bumper reinforcement structure comprising a support structure for receiving a load acting on the vehicle body,
The body member has a hat-shaped cross-sectional shape with an inner side in the longitudinal direction of the automobile body having a longitudinal cross-sectional shape, and the opening of the hat-shaped cross section is at least within a width direction range between the support structures of the body member. A bumper reinforcement structure in which each of the long-plate-shaped reinforcing plates fixed to the upper and lower ends is formed as a separate member and arranged separately. The bumper reinforcement structure according to claim 1,
The reinforcing plate has a bumper reinforcement structure that is fixed and arranged on the inner surface side of the hat-shaped main body member by welding. The bumper reinforcement structure according to claim 2,
The elongated plate-shaped reinforcing plate has an L-shaped longitudinal cross-sectional shape, and one side of the L-shaped is fixed and disposed by welding along the inner surface side of the opening end of the main body member. A bumper reinforcement structure in which the other side of the L-shape extends and is arranged inward of the main body member. The bumper reinforcement structure according to claim 3,
The arrangement position of the L-shaped reinforcing plate is a bumper reinforcement in which the other side of the L-shape is an outer position in the front-rear direction of the vehicle body from the opening end position of the hat-shaped cross-sectional body member. Construction. The bumper reinforcement structure according to any one of claims 1 to 4,
A bumper reinforcement structure in which a central portion of a top surface of a hat-shaped cross-sectional shape that is a contact surface in the main body member is formed in a concave shape in an inner side direction in the front-rear direction of the automobile body.

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