JP2012188092A - Reinforcement and bumper device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement which can inhibit buckling distortion when a vehicle crashes even when using an aluminum-alloy material of 7000 system, and a bumper device which is excellent in impact absorbing properties.SOLUTION: The reinforcement 1 for use to reinforce a vehicular bumper is formed with a hollow mold member made of the aluminum-alloy material of the 7000 system having bearing force of at least 300 MPa, and has an impact absorbing member 2 attached thereto for absorbing impact when the vehicle crashes. On a sidewall surface 12a almost in parallel with a vehicular longitudinal direction FR in a fixation part 14 of the impact absorbing member 2, groove-like bead parts 15 are formed which are configured with an inside groove part 151 and an outside groove part 152 extending in the vehicular longitudinal direction FR. The bottom length of each of the groove parts 151, 152 is designed to be equal to or less than 1/2 of the size of the sidewall surface 12a in the vehicular longitudinal direction FR.

Description

  The present invention relates to a reinforcement and a bumper device.

  Conventionally, bumpers are provided in front and rear of a vehicle such as an automobile in order to absorb an impact at the time of the collision of the vehicle and reduce an impact energy transmitted to the vehicle. Generally, the bumper has a resin outer cover, a reinforcement extending in the vehicle width direction, and a foamed resin that fills a gap between the outer cover and the reinforcement. The reinforcement is attached to the frame of the vehicle main body via an impact absorbing member that absorbs an impact caused by a vehicle collision by buckling deformation.

  In recent years, there has been a demand for lighter vehicles such as automobiles due to environmental problems. For this reason, replacement of conventional steel materials with aluminum alloy materials has been studied and implemented for reinforcements and impact absorbing members that are components of vehicles. For example, Patent Document 1 discloses that an aluminum alloy material is used as a reinforcement material in a bumper device in which an impact absorbing member is fixed to the reinforcement.

  As an aluminum alloy material used for the reinforcement, a 6000 series aluminum alloy material has been used so far. Recently, in order to further reduce the weight by reducing the thickness, the use of a 7000 series aluminum alloy material having higher proof strength than the 6000 series aluminum alloy material has been studied and implemented.

JP 2010-264875 A

  However, the prior art has problems in the following points. That is, although the 7000 series aluminum alloy material has a higher yield strength than the 6000 series aluminum alloy material, it has less elongation. Therefore, as shown in FIG. 10, the bumper device 93 to which the reinforcement 91 made of a hollow material made of a 7000 series aluminum alloy material is applied is a vehicle of the reinforcement 91 as shown by a broken line H at the time of a vehicle collision. There is a problem in that the side wall surface 12a (and / or the side wall surface 12b facing the side wall surface 12a, not shown) parallel to the front-rear direction FR buckles first and cracks occur. When the reinforcement 91 buckles first and cracks, the load is not transmitted to the impact absorbing member 2 and the impact energy absorption characteristics of the bumper device 93 are deteriorated.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a reinforcement capable of suppressing buckling deformation at the time of a vehicle collision even when a 7000 series aluminum alloy material is used. It is another object of the present invention to provide a bumper device having excellent shock absorption characteristics.

  The present invention is a reinforcement for reinforcing a bumper of a vehicle, comprising a hollow shape member made of an aluminum alloy material, to which an impact absorbing member that absorbs an impact at the time of a vehicle collision is fixed. It is a 7000 series aluminum alloy material of 300 MPa or more, and at least one side wall surface substantially parallel to the vehicle longitudinal direction in the fixed portion of the shock absorbing member is constituted by at least one groove extending in the vehicle longitudinal direction. A groove-shaped bead portion is formed, and the length of the bottom portion of the groove portion is set to ½ or less of the dimension in the vehicle front-rear direction of the side wall surface. Item 1).

  According to another aspect of the present invention, there is provided a bumper device including the reinforcement and an impact absorbing member fixed to the reinforcement.

  Since the reinforcement according to the present invention has the above-described configuration, buckling deformation can be suppressed during a vehicle collision even when a 7000 series aluminum alloy material is used. In addition, the bumper device using the reinforcement is excellent in impact absorption characteristics.

  Specifically, the reinforcement of the present invention is composed of a hollow material made of a 7000 series aluminum alloy material having a high yield strength of 300 MPa or more. And the groove-shaped bead part of the said structure is formed in the at least 1 or more side wall surface substantially parallel to the vehicle front-back direction in the fixing | fixed part of the said shock-absorbing member. Therefore, it is difficult for the side wall surface to buckle at the time of a vehicle collision. In the bumper device using the reinforcement, the collision load is easily transmitted to the shock absorbing member without buckling deformation of the reinforcement. Therefore, the shock absorbing member is appropriately deformed substantially bellows and is excellent in shock absorbing characteristics.

It is explanatory drawing which shows the structure (however, the left half when applied to the vehicle front direction, ie, the front bumper side), in Example 1, the reinforcement and the bumper device. It is explanatory drawing which shows the cross-sectional shape of the reinforcement in Example 1. FIG. In Example 1, it is explanatory drawing which shows typically a part of AA cross section of the reinforcement. In Example 1, it is explanatory drawing which shows typically a part of BB cross section of the reinforcement. It is explanatory drawing which shows CC cross section of the groove-shaped bead part in the reinforcement in Example 1. FIG. It is explanatory drawing which shows the outline of the evaluation method by simulation. It is a simulation result which shows the relationship between jig | tool displacement-load. It is explanatory drawing which shows the structure (however, the left half when applied to the vehicle front direction, ie, the front bumper side), in Example 2, the reinforcement and the bumper device. It is explanatory drawing which shows the structure (however, the left half when applied to the vehicle front direction, ie, the front bumper side) of the reinforcement and the bumper device in the third embodiment. It is explanatory drawing which shows the structure (however, the left half when applied to the vehicle front direction, ie, the front bumper side) of the conventional reinforcement and bumper apparatus.

  The reinforcement is for reinforcing the bumper of the vehicle and is made of a hollow material made of an aluminum alloy material. As the aluminum alloy material, a 7000 series aluminum alloy material having a yield strength of 300 MPa or more is used. In addition, the said yield strength is a value measured based on JISZ2241. Specific examples of the 7000 series aluminum alloy include 7003, 7N01, 7075, and the like.

  The hollow shape member constituting the reinforcement has at least one or more side wall surfaces substantially parallel to the vehicle longitudinal direction. Specifically, the shape of the hollow shape member is, for example, substantially composed of a pair of side wall surfaces facing each other substantially parallel to the vehicle longitudinal direction and a pair of side wall surfaces facing each other substantially parallel to the vehicle vertical direction. A square tube shape and the like can be exemplified. In this case, one or more ribs that connect the inner surfaces of a pair of side wall surfaces facing each other substantially parallel to the vertical direction of the vehicle may be provided. The cross-sectional shape when the hollow shape member is cut in the vehicle front-rear direction is preferably a substantially rectangular shape, a substantially “day” shape, a substantially “eye” shape, a substantially “field” shape, etc. can do. In addition, about the side wall surface substantially parallel to a vehicle up-down direction, you may protrude from the side wall surface substantially parallel to the vehicle front-back direction. Such a hollow shape can be suitably manufactured using an extrusion molding method or the like.

  The thickness of the side wall surface and the rib is preferably in the range of 1.8 mm to 2.5 mm. When the thickness of the side wall surface and the rib is 1.8 mm or more, since the extrudability is excellent, a hollow shape can be easily formed by an extrusion molding method. On the other hand, even if the thickness of the side wall surface and the rib is thicker than 2.5 mm, the effect of improving the cross-sectional rigidity (cross-sectional second moment) is small. Therefore, it is not preferable to make the rib thicker than 2.5 mm from the viewpoint of weight reduction.

  An impact absorbing member that absorbs an impact at the time of a vehicle collision is fixed to the reinforcement. Two shock absorbing members can be fixed to the reinforcement. More specifically, one end of the impact absorbing member is fixed to the reinforcement, while the other end is fixed to the frame of the vehicle body. Therefore, the position of the fixing portion of the impact absorbing member in the reinforcement is determined in accordance with the positional relationship with the frame of the vehicle body that fixes the impact absorbing member.

  For example, when the other ends of the two shock absorbing members are fixed to the left and right frames extending in the vehicle front-rear direction among the frames of the vehicle body, the position where the substantially extended line of the left and right frames intersects with the reinforcement, Generally, it is the position of the fixed portion of each shock absorbing member. Reinforcement is often bent at both ends toward the inner side of the vehicle in the longitudinal direction of the vehicle due to the design of the vehicle. Therefore, in such a case, the position of the fixed portion of the impact absorbing member in the reinforcement often exists at each bent portion formed at each end of the reinforcement.

  The impact absorbing member fixed to the reinforcement is not particularly limited, and various members can be applied. As the impact absorbing member, for example, an impact absorbing member having a substantially square cylindrical impact absorbing portion constituted by four side wall surfaces can be suitably used. Specifically, a shock-absorbing member having a hollow extruded shape made of an aluminum alloy material as a shock-absorbing portion, or a bottomed substantially square cylindrical body formed by deep drawing a single aluminum alloy sheet by press molding. An impact absorbing member having a substantially square cylindrical portion as an impact absorbing portion can be suitably used.

  Note that the former shock-absorbing member using the hollow extruded shape member preferably has a fixing plate for fixing to the reinforcement at one end and a solid plate for fixing to the frame of the vehicle main body at the other end. Moreover, it is preferable that the impact-absorbing member by the latter press molding has the flange part which protrudes on the outer periphery of the opening end on the opposite side to a bottom part. It is because the attachment to the frame of the reinforcement or the vehicle body can be improved. Examples of the method of fixing the impact absorbing member to the reinforcement or the frame of the vehicle body include, for example, fastening by a fastening member such as a bolt or nut, mechanical joining by caulking or self-piercing rivet, FSW, spot welding, etc. be able to.

  In the reinforcement, a groove-shaped bead portion is formed on at least one side wall surface of the fixed portion of the shock absorbing member that is substantially parallel to the vehicle longitudinal direction. When the reinforcement has two side wall surfaces substantially parallel to the vehicle front-rear direction, the groove-shaped bead portions may be formed on both side wall surfaces substantially parallel to the vehicle front-rear direction, or in the vehicle front-rear direction. It may be formed on one side of the substantially parallel side wall surface. For example, when the reinforcement is composed of a substantially rectangular tube-shaped hollow member having a pair of side wall surfaces substantially parallel to the vehicle longitudinal direction and a pair of side wall surfaces substantially parallel to the vehicle vertical direction, A groove-shaped bead portion may be formed on both of the pair of side wall surfaces substantially parallel to each other, or a groove-shaped bead portion may be formed on one of the pair of side wall surfaces. When the groove-shaped bead portion is formed on all the side wall surfaces substantially parallel to the vehicle front-rear direction, there is an advantage that buckling deformation at the time of vehicle collision can be further suppressed.

  The groove-shaped bead portion is composed of at least one groove portion extending in the vehicle front-rear direction per one fixed portion of the shock absorbing member. The number of the groove portions is not particularly limited. The number of the groove portions is preferably 2 to 5, and more preferably 2 to 3. Moreover, the width | variety and depth of the said groove part are not specifically limited. The width of the groove is preferably 5 to 25 mm, more preferably 10 to 20 mm, from the viewpoint of ease of formation, buckling suppression effect, and the like. The depth of the groove is preferably 3 to 15 mm, more preferably 5 to 12 mm, from the viewpoint of ease of formation, buckling suppression effect, and the like.

  Further, as long as the groove extends along the vehicle front-rear direction, the groove may extend from the side wall surface inside the vehicle front-rear direction toward the vehicle outer side in the vehicle front-rear direction. You may extend toward the vehicle inner side of the vehicle front-back direction from the side wall surface side in the outer side. Furthermore, you may extend toward the vehicle outer side and vehicle inner side of the vehicle front-back direction from the approximate center of the vehicle front-back direction in the side wall surface substantially parallel to the vehicle front-back direction.

  It is preferable that the groove-shaped bead portion has at least one groove portion formed around an extension line in the vehicle front-rear direction passing through a contact point where the side wall surface on the vehicle width side in the vehicle width direction of the shock absorbing member contacts. Further, in this case, it is preferable that the groove portion extends from the side wall surface side on the vehicle inner side in the vehicle front-rear direction toward the vehicle outer side in the vehicle front-rear direction. This is because folding of the side wall surface at the time of a vehicle collision is likely to occur from the vehicle inner side in the vehicle width direction, particularly from the side of the side wall surface on the inner side of the vehicle in the vehicle front-rear direction.

  The length of the bottom of the groove is set to be 1/2 or less of the dimension in the vehicle front-rear direction of the side wall surface where the groove is formed. The “dimension in the vehicle front-rear direction of the side wall surface where the groove is formed” does not include the dimension in the vehicle front-rear direction of the other side wall surface in contact with the side wall surface where the groove is formed. In addition, the length of the opening portion of the groove portion that exists on the same plane as the side wall surface on which the groove portion is formed may be 1/2 or more of the dimension in the vehicle front-rear direction of the side wall surface on which the groove portion is formed. Good. When the length of the bottom portion of the groove portion is set to ½ or less of the dimension of the side wall surface in the vehicle front-rear direction, the length of the opening portion of the groove portion may vary depending on the groove forming method such as a press molding method. This is because there may be a case where the size of the wall surface is 1/2 or more of the dimension in the vehicle longitudinal direction.

  The length of the bottom of the groove is preferably set to 9/20 or less of the dimension in the vehicle front-rear direction of the side wall surface on which the groove is formed, from the viewpoint of ease of molding. On the other hand, the length of the bottom of the groove is preferably ¼ or more of the dimension in the vehicle front-rear direction of the side wall on which the groove is formed, from the viewpoint of ease of formation, prevention of buckling of the side wall, and the like. Preferably, it should be set to 1/3 or more.

  In the reinforcement, the groove-shaped bead portion includes an inner groove portion formed around an extension line in the vehicle front-rear direction passing through a contact point where a vehicle inner side wall surface in the vehicle width direction of the shock absorbing member contacts, and the shock absorbing member. Preferably, the member has an outer groove formed around an extension line in the vehicle front-rear direction passing through a contact point with which the side wall surface on the vehicle outer side in the vehicle width direction contacts.

  In this case, when there is no groove-shaped bead portion, it is possible to improve the buckling deformation resistance around the portion corresponding to almost both ends of the fold generated on the side wall surface. Therefore, the side wall surface is less likely to buckle during a vehicle collision. The “periphery of the extension line” means that the center line of the groove portion does not necessarily need to coincide with the extension line, and within the range where the side wall surface does not buckle, It means that the center line of the groove portion may be present outside the vehicle.

  Further, in the reinforcement, the inner groove portion extends from a side wall surface side on the vehicle inner side in the vehicle front-rear direction toward the vehicle outer side in the vehicle front-rear direction, and the outer groove portion is formed on the vehicle outer side in the vehicle front-rear direction. It is preferable to extend from a certain side wall surface side toward the vehicle inner side in the vehicle front-rear direction.

  As described above, the reinforcement is bent and often has bent portions that bend inward in the vehicle longitudinal direction at both ends thereof. When the reinforcement has such a shape, the side wall surface that is substantially parallel to the vehicle longitudinal direction of the reinforcement folds on the side wall surface inside the vehicle in the vehicle longitudinal direction on the vehicle inner side in the vehicle width direction. Is likely to occur. On the other hand, on the vehicle outer side in the vehicle width direction, the folding tends to occur on the side wall surface side on the vehicle outer side in the vehicle front-rear direction. Therefore, in the case of having the above configuration, buckling deformation can be reliably suppressed even when the reinforcement is bent.

  In addition, when a groove-shaped bead part has two or more groove parts, the length of the bottom part of each groove part may be the same, and may differ.

  In the reinforcement, the longitudinal center line of the inner groove portion is an extension line in the vehicle front-rear direction passing through a contact point where the side wall surface in the vehicle width direction of the shock absorbing member contacts ± 20 mm in the vehicle width direction (however, , The vehicle inner side in the vehicle width direction is defined as the + side and the vehicle outer side is defined as the-side.) The longitudinal center line of the outer groove portion is the vehicle outer side in the vehicle width direction of the shock absorbing member. The vehicle extends in the longitudinal direction of the vehicle passing through the contact point where the side wall surface is in contact ± 20 mm in the vehicle width direction (provided that the vehicle inner side in the vehicle width direction is the + side and the vehicle outer side is the-side). (Claim 4).

  In this case, there is an effect of suppressing buckling deformation of the side wall surface at the time of a vehicle collision. The longitudinal center line of the inner groove portion and the longitudinal center line of the outer groove portion are preferably each extension line ± 15 mm or less in the vehicle width direction, more preferably each extension line ± 10 mm or less in the vehicle width direction. It is good to exist within the range.

  In the reinforcement, the groove part preferably has two inclined surfaces inclined toward the bottom part of the groove part (Claim 5).

  In this case, it is excellent in the balance between the effect of suppressing the buckling deformation of the reinforcement and the formability of the groove. Moreover, the bottom face may exist in the bottom part of the said groove part. Specifically, as the cross-sectional shape of the groove portion, for example, a substantially “V” shape (substantially inverted triangle shape), a substantially trapezoidal shape (when the lower bottom of the trapezoid is the bottom of the groove, the lower bottom of the trapezoid is For example, shorter than the bottom).

  In the bumper device, one end of the impact absorbing member is fixed to the reinforcement. Specifically, the bumper device, for example, is formed by bending a reinforcement and has bent portions that bend inwardly in the vehicle front-rear direction at both ends, and the shock absorbing member is provided at each bent portion. Can be fixed one by one. The groove-shaped bead portion is formed on at least one or more side wall surfaces substantially parallel to the vehicle front-rear direction in the fixed portion of the impact absorbing member of the reinforcement.

  The reinforcement and bumper device described above can be applied to either the front bumper side or the rear bumper side of the vehicle. In the bumper device, the impact absorbing member is often disposed at a bent portion of the reinforcement, but can be disposed at a location other than the bent portion of the reinforcement.

Example 1
A reinforcement and a bumper device according to an embodiment of the present invention will be described with reference to FIGS. In all the drawings, FR means the vehicle front-rear direction, FRI means the vehicle inner side in the vehicle front-rear direction, and FRO means the vehicle outer side in the vehicle front-rear direction. W represents the vehicle width direction, WI represents the vehicle inner side in the vehicle width direction, and WO represents the vehicle outer side in the vehicle width direction. Moreover, UD means the vehicle vertical direction, U means the vehicle upper side, and D means the vehicle lower side. These symbols are used as appropriate in the following description. Note that the reinforcement and bumper device in this example are assumed to be applied to the front bumper side of the vehicle. However, the reinforcement and bumper device in this example are not limited to this. It can also be applied to the bumper side.

<Rainforce>
The reinforcement 1 of this example is for reinforcing a bumper of an automobile as a vehicle. As shown in FIGS. 1 and 2, the reinforcement 1 is made of a hollow shape made of an aluminum alloy material and absorbs an impact at the time of a vehicle collision. The absorbing member 2 is fixed.

  A7N01-T6, which is an aluminum alloy material having a proof stress of 320 MPa, was used as the hollow material constituting the reinforcement 1. The reinforcement 1 extends in the vehicle width direction W, and is formed by bending both ends toward the vehicle inner side FRI in the vehicle front-rear direction so as to have an angle of 10 ° with the vehicle width direction W. And a bent portion 11. One end of the impact absorbing member 2 is fixed to the side wall surface 12c of the vehicle inner side FRI in the vehicle front-rear direction at the bent portion 11 of the reinforcement 1.

  FIG. 1 shows the reinforcement 1 when applied to the front bumper side, and the left half of the bumper device 3 described later. In FIG. 1, on the right side of the center line S, the left half of the reinforcement 1 and the bumper device 3 in the front direction of the vehicle is symmetrical to the left half of the reinforcement 1 and the bumper device 3. Is present. Therefore, in the reinforcement 1 of this example, the shock absorbing member 2 is fixed to each bending portion 11 one by one. Further, the bumper device 3 described later also has two shock absorbing members 2.

  Specifically, the reinforcement 1 is made of a hollow material by extrusion. As shown in FIG. 2A, the hollow shape member is formed so that the cross-sectional shape when cut in the vehicle front-rear direction FR is substantially a “day” shape. That is, the hollow shape member constituting the reinforcement 1 is substantially angled from a pair of side wall surfaces 12a, 12b substantially parallel to the vehicle longitudinal direction FR and a pair of side wall surfaces 12c, 12d substantially parallel to the vehicle vertical direction UD. It has a cylindrical shape. The inner surfaces of the pair of side wall surfaces 12c and 12d that are substantially parallel to the vehicle vertical direction UD are connected by a central rib 13 that is substantially parallel to the vehicle longitudinal direction FR.

  In this example, the side wall surfaces 12c and 12d that are substantially parallel to the vehicle vertical direction UD have a dimension of 100 mm, a thickness of 4 mm, and a side wall surface 12a that is substantially parallel to the vehicle longitudinal direction FR. , 12b had a dimension of 80 mm, a thickness of 2 mm, and a central rib having a thickness of 2 mm. As shown in FIG. 2 (b), the reinforcement 1 includes a side wall surface 12c of the vehicle inner side FRI in the vehicle front-rear direction and a side wall surface 12d of the vehicle outer side FRO in the vehicle front-rear direction. May protrude from the side wall surface 12a of the vehicle and the side wall surface 12b of the vehicle lower side D in the vehicle vertical direction.

  Here, as shown in FIG. 1, the reinforcement 1 of the present example has at least one or more side wall surfaces (in this example, the side wall surface 12 a) that are substantially parallel to the vehicle longitudinal direction FR in the fixing portion 14 of the shock absorbing member 2. The groove-shaped bead portion 15 is formed on the side wall surface 12b). The groove-shaped bead portion 15 includes at least one groove portion (in this example, the inner groove portion 151 and the outer groove portion 152) extending in the vehicle longitudinal direction FR.

  The groove-shaped bead portion 15 includes an inner groove portion 151 formed on the extension line Li in the vehicle front-rear direction FR passing through the contact point Ci that contacts the side wall surface 2c of the vehicle inner side WI in the vehicle width direction in the shock absorbing member 2, and the shock absorbing member. 2 has an outer groove 152 formed on an extended line Lo in the vehicle front-rear direction FR that passes through a contact point Co that contacts the side wall surface 2d of the vehicle outer side WO in the vehicle width direction. In this example, the longitudinal center line Mi and the extension line Li of the inner groove 151 and the longitudinal center line Mo and the extension line Lo of the outer groove 152 are substantially matched.

  The inner groove 151 is formed so as to extend from the side wall surface 12c side in the vehicle inner side FRI in the vehicle front-rear direction toward the vehicle outer side FRO in the vehicle front-rear direction. On the other hand, the outer groove portion 152 is formed so as to extend from the side wall surface 12d side on the vehicle outer side FRO in the vehicle front-rear direction toward the vehicle inner side FRI in the vehicle front-rear direction.

In the reinforcement 1 of this example, the groove-shaped bead portion 15 is composed of two groove portions, that is, the inner groove portion 151 and the outer groove portion 152 as described above. As shown in FIGS. 3 and 4, the lengths ti and to of the bottoms 154 of the grooves 151 and 152 are set to be 1/2 or less of the dimension T in the vehicle longitudinal direction FR of the side wall surface 12a (12b). Yes. In the reinforcement 1 of the present example, specifically, the lengths ti and to of the bottoms 154 of the grooves 151 and 152 are set to 30 mm.
Therefore, ti and to are 1/2 or less of T = 80 / cos 10 ° −2 × thickness (4 mm) = 73.23 mm. As shown in FIGS. 1, 3, and 4, “the dimension of the side wall surface in the vehicle longitudinal direction” does not include the dimension of the side wall surface 12c and the side wall surface 12d in the vehicle longitudinal direction FR.

  In the reinforcement 1 of this example, as shown in FIG. 5, the inner groove portion 151 and the outer groove portion 152 are formed in a substantially “V” shape in cross section over the length of the bottom portion 154 of each groove portion 151, 152. ing. That is, the inner groove portion 151 and the outer groove portion 152 have two inclined surfaces 155a and 155b that are inclined toward the bottom portion 154 of each groove portion over the length of the bottom portion 154 of each groove portion. The inner groove 151 and the outer groove 152 having such a shape were formed by subjecting a hollow shape formed by extrusion molding to press molding. The widths of the inner groove 151 and the outer groove 152 were both 10 mm. Moreover, the depth of the inner side groove part 151 and the outer side groove part 152 was 5 mm.

<Bumper device>
As shown in FIG. 1, the bumper device 3 of this example includes the above-described reinforcement 1 and an impact absorbing member 2 fixed to the reinforcement 1.

  Specifically, the bumper device 3 has an entire circumference of one end of the shock absorbing member 2 having a hollow shape made of an aluminum alloy material as a shock absorbing portion on each bent portion 11 formed at both ends of the reinforcement 1. Each is fixed by welding. As the aluminum alloy material, A6061-T6 having a proof stress of 280 MPa was used.

  The shock absorbing member 2 has a substantially rectangular cross-sectional shape when cut in the vehicle width direction W, and a pair of side wall surfaces 2a and 2b (the side wall surfaces 2b are not shown in the figure). And a pair of side wall surfaces 2c, 2d substantially parallel to the vehicle up-down direction UD, and a substantially rectangular tube shape. The width of the shock absorbing member 2 (dimension in the vehicle width direction W) was 110 mm. The height of the shock absorbing member 2 (dimension in the vehicle vertical direction UD) was 90 mm.

  In the bumper device 3, of the side wall surfaces 2 a to 2 d of the shock absorbing member 2, a contact point Ci (side wall surface 12 b side) between the side wall surface 2 c on the vehicle inner side WI in the vehicle width direction and the side wall surfaces 12 a and 12 b of the reinforcement 1. The inner groove portion 151 of the groove-shaped bead portion 15 is disposed on an extension line Li passing through the contact point Ci of the groove-shaped bead 15. On the other hand, of the side wall surfaces 2a to 2d of the impact absorbing member 2, the contact point Co (contact point on the side wall surface 12b side) between the side wall surface 2d on the vehicle outer side WO in the vehicle width direction W and the side wall surfaces 12a and 12b of the reinforcement 1 An outer groove portion 152 of the groove-shaped bead portion 15 is disposed on an extension line Lo passing through Co (not shown). In this example, the longitudinal center line Mi and the extension line Li of the inner groove 151 and the longitudinal center line Mo and the extension line Lo of the outer groove 152 are substantially matched.

<Collision performance evaluation>
Hereinafter, in order to evaluate the collision performance, a simulation using commercially available FEM analysis software was performed on the bumper device 3 to which the reinforcement 1 having the shape shown in FIG. 1 was applied.

First, the bumper device 3 to which the reinforcement 1 having the shape shown in FIG. 1 was applied was converted into a mesh model, and an analysis model was created. Next, the following characteristics were input to the analysis model.
That is, the reinforcement 1 is made of a hollow extruded shape made of an aluminum alloy material (A7N01-T6) having a proof stress of 320 MPa, and the shock absorbing member 2 is made of an aluminum alloy material (A6016-T6) having a proof strength of 280 MPa. Therefore, stress-strain characteristics assuming each proof stress were input to the analysis model.

  Further, the cross-sectional shape when the reinforcement 1 was cut in the vehicle front-rear direction FR was substantially “Sun”. In a substantially “Sun” -shaped cross-sectional shape, the dimensions of the side wall surfaces 12c and 12d substantially parallel to the vehicle vertical direction UD are 100 mm, the thickness is 4 mm, and the dimension of the side wall surfaces 12a and 12b substantially parallel to the vehicle longitudinal direction FR is 80 mm. The thickness was 2 mm, and the thickness of the central rib was 2 mm. In addition, the reinforcement 1 was in a state where both ends were bent so as to have an angle of 10 ° with the vehicle width direction W. The reinforcement 1 has groove-shaped bead portions 15 on both side wall surfaces 12a and 12b substantially parallel to the vehicle longitudinal direction FR. The lengths of the bottom portions 154 of the inner groove portion 151 and the outer groove portion 153 are as follows. The width was 40 mm, the width was 10 mm, and the depth was 5 mm.

  Next, as shown in FIG. 6, a simulation was performed in which the mesh modeled load jig 4 collided with the analysis model to which the above characteristics were input. A condition referring to ODB (Offset Deformable Barrier) was input as an analysis condition based on the analysis model. Specifically, the other end side (vehicle body frame side) of the shock absorbing member 2 fixed to the bumper device 3 is completely restrained, and the load jig 4 is set to a full length of the reinforcement 1 at a speed setting of 1000 mm / s. The reaction force to the load jig 4 caused by the collision with the bumper device 3 with respect to the displacement amount of the load jig 4 and the side of the reinforcement 1 that is substantially parallel to the vehicle longitudinal direction FR The simulation which outputs the deformation | transformation form of the wall surfaces 12a and 12b was performed.

  For comparison, as shown in FIG. 10, the reinforcement 91 is the same as that shown in FIG. 1 except that the groove-shaped bead portions 15 are not formed at all on the side wall surfaces 12a and 12b substantially parallel to the vehicle longitudinal direction FR. A simulation similar to the above was performed for the bumper device 93 (Comparative product 1) using the above.

  The simulation result is shown in FIG. In FIG. 7, the impact energy absorption amount is calculated by the amount of displacement of the load jig × the area of the load region. As shown in FIG. 7, the bumper device 93 of the comparative product 1 uses a reinforcement 91 that does not have the groove-shaped bead portion 15 on the side wall surfaces 12a and 12b in the vehicle front-rear direction FR. Therefore, at the position of the broken line H in FIG. 10, the side wall surfaces 12a and 12b in the vehicle front-rear direction FR are buckled and bent. On the other hand, the bumper device 3 of the invention uses the reinforcement 1 having the groove-shaped bead portions 15 on the side wall surfaces 12a and 12b in the vehicle longitudinal direction FR. Therefore, buckling deformation does not occur on the side wall surfaces 12 a and 12 b in the vehicle front-rear direction FR, and impact energy is reliably transmitted to the shock absorbing member 2.

  From the above, it can be seen that the reinforcement 1 of Example 1 can suppress buckling deformation at the time of a vehicle collision, even though a 7000 series aluminum alloy material is used. In addition, it can be seen that the bumper device 3 of Example 1 using the reinforcement 1 of Example 1 is excellent in impact absorption characteristics because buckling deformation does not occur in the reinforcement 1 at the time of a vehicle collision.

(Example 2)
In this example, as shown in FIG. 8, the formation positions of the inner groove portion 151 and the outer groove portion 152 constituting the groove-shaped bead portion 15 in the reinforcement 1 of the first embodiment are shifted in the vehicle width direction W.

  In the reinforcement 1 of this example, the longitudinal center line Mi of the inner groove 151 is an extension line Li in the vehicle front-rear direction FR passing through the contact point Ci where the side wall surface 2c of the vehicle inner side WI in the vehicle width direction of the shock absorbing member 2 contacts. The vehicle width direction is 20 mm (however, the vehicle inner side WI in the vehicle width direction is on the + side and the vehicle outer side WO is on the-side). In addition, the longitudinal center line Mo of the outer groove portion 152 is an extension line Lo ± 20 mm in the vehicle width direction in the vehicle front-rear direction FR passing through the contact point Co where the side wall surface 2d of the vehicle outer side WO in the vehicle width direction of the shock absorbing member 2 contacts. The vehicle inner side WI in the vehicle width direction is on the + side and the vehicle outer side WO is on the − side.

  Specifically, in the reinforcement 1 of this example, the longitudinal center line Mi of the inner groove 151 is the vehicle longitudinal direction passing through the contact point Ci where the side wall surface 2c of the vehicle inner side WI in the vehicle width direction of the shock absorbing member 2 contacts. It is in the position which shifted | deviated 12 mm to the vehicle inner side WI of the vehicle width direction rather than the extended line Li. In FIG. 8, Li (+) is a position shifted by 20 mm toward the vehicle inner side WI in the vehicle width direction from the extension line Li in the vehicle front-rear direction. In addition, Li (−) is a position that is shifted 20 mm toward the vehicle outer side WO in the vehicle width direction from the extension line Li in the vehicle front-rear direction.

  On the other hand, the longitudinal center line Mo of the outer groove portion 152 is a vehicle in the vehicle width direction more than the extension line Lo in the vehicle front-rear direction FR passing through the contact point Co where the side wall surface 2d of the vehicle outer side WO in the vehicle width direction in the shock absorbing member 2 contacts. It is at a position 8 mm away from the outer WO. In FIG. 8, Lo (+) is a position that is displaced 20 mm toward the vehicle inner side WI in the vehicle width direction from the extension line Lo in the vehicle front-rear direction. In addition, Lo (−) is a position shifted by 20 mm from the vehicle outer side WO in the vehicle width direction with respect to the extension line Lo in the vehicle front-rear direction. Other configurations are the same as those of the reinforcement 1 of the first embodiment. Further, the bumper device 3 of this example has the same configuration as the bumper device 3 of Example 1 except that the reinforcement 1 of this example is used.

  Even in such a configuration, a bumper device excellent in reinforcement and shock absorption characteristics capable of suppressing buckling deformation at the time of a vehicle collision can be obtained.

(Example 3)
In this example, as shown in FIG. 9, in the reinforcement 1 of the first embodiment, an intermediate groove portion 153 is further formed between the inner groove portion 151 and the outer groove portion 152 constituting the groove-shaped bead portion 15. It is.

  Specifically, in the reinforcement 1 of this example, the intermediate groove portion 153 is formed at a position equidistant from the inner groove portion 151 and the outer groove portion 152 in the vehicle width direction W. The intermediate groove portion 153 is formed to extend from the middle of the dimension T in the vehicle front-rear direction FR of the side wall surface 12a by an equal distance from the vehicle inner side FRI and the vehicle outer side FRO in the vehicle front-rear direction. Other configurations are the same as those of the reinforcement 1 of the first embodiment. Further, the bumper device 3 of this example has the same configuration as the bumper device 3 of Example 1 except that the reinforcement 1 of this example is used.

  Even in such a configuration, a bumper device excellent in reinforcement and shock absorption characteristics capable of suppressing buckling deformation at the time of a vehicle collision can be obtained.

  In this example, the intermediate groove portion 153 is disposed as described above, but the present invention is not limited to this, and the intermediate groove portion 153 can be appropriately disposed between the inner groove portion 151 and the outer groove portion 152. Preferably, as shown in FIG. 10, it is good to arrange so that it may overlap with the broken line H which is a position where a crack is assumed. This is because it is easy to suppress buckling deformation of the reinforcement 1 at the time of a vehicle collision.

  Although the embodiments have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

1 Reinforcement 11 Bending part 12a Side wall surface (vehicle upper side)
12b Side wall surface (vehicle lower side)
12c Side wall (vehicle inside)
12d Side wall surface (vehicle outside)
14 Fixed portion 15 Groove-shaped bead portion 151 Inner groove portion 152 Outer groove portion 154 Bottom portions 155a, 155b Inclined surface 2 Shock absorbing member 3 Bumper device T Dimensions in the vehicle front-rear direction of the side wall surface substantially parallel to the vehicle front-rear direction (inner dimensions)
ti Length of bottom of inner groove to length of bottom of outer groove Li Extension line (vehicle inside)
Lo extension line (vehicle outside)
Mi center line (inner groove)
Mo center line (outer groove)

Claims (6)

A reinforcement for bumper reinforcement of a vehicle, comprising a hollow shape member made of an aluminum alloy material, to which a shock absorbing member for absorbing a shock at the time of a vehicle collision is fixed,
The aluminum alloy material is a 7000 series aluminum alloy material having a yield strength of 300 MPa or more,
A groove-shaped bead portion composed of at least one groove portion extending in the vehicle front-rear direction is formed on at least one side wall surface substantially parallel to the vehicle front-rear direction in the fixed portion of the shock absorbing member,
The length of the bottom of the groove is set to be 1/2 or less of the dimension of the side wall surface in the vehicle front-rear direction. The reinforcement according to claim 1,
The groove-shaped bead portion is
An inner groove portion formed around the extension line in the vehicle front-rear direction passing through a contact point where the side wall surface on the vehicle inner side in the vehicle width direction in the impact absorbing member contacts;
A reinforcement having an outer groove formed around an extension line in the vehicle front-rear direction passing through a contact point where a side wall surface on the vehicle outer side in the vehicle width direction of the impact absorbing member contacts. In the reinforcement according to claim 2,
The inner groove portion extends from the side wall surface side on the vehicle inner side in the vehicle front-rear direction toward the vehicle outer side in the vehicle front-rear direction,
The outer groove portion extends from the side wall surface side on the vehicle outer side in the vehicle front-rear direction toward the vehicle inner side in the vehicle front-rear direction. In the reinforcement according to any one of claims 1 to 3,
The longitudinal center line of the inner groove portion is an extension line in the vehicle front-rear direction passing through a contact point where the side wall surface in the vehicle width direction of the shock absorbing member contacts ± 20 mm in the vehicle width direction (however, the vehicle inner side in the vehicle width direction + Side, the outside of the vehicle is the-side)),
The longitudinal center line of the outer groove portion is an extension line in the vehicle front-rear direction passing through a contact point where the vehicle outer side wall surface in the vehicle width direction of the shock absorbing member contacts ± 20 mm in the vehicle width direction (however, the vehicle inner side in the vehicle width direction Reinforcement characterized by existing within a range of + side and vehicle outside-side. In the reinforcement according to any one of claims 1 to 4,
The groove portion has two inclined surfaces inclined toward the bottom portion of the groove portion.   A bumper device comprising: the reinforcement according to any one of claims 1 to 5; and an impact absorbing member fixed to the reinforcement.

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