JP5462743B2 - Bumper structure - Google Patents

Description

  The present invention relates to a bumper structure.

  Patent Documents 1 and 2 disclose a bumper structure for an automobile including a bumper reinforcement and a pair of left and right bumper stays that support the bumper reinforcement. This bumper structure absorbs collision energy in the process of bending deformation in the bumper reinforcement (hereinafter referred to as the “beam bending process”) and reduces the bumper stay into the bumper reinforcement (hereinafter referred to as “beam collapse”). The collision energy is absorbed in the “process”, and the collision energy is absorbed in the process in which the bumper stay is crushed (hereinafter referred to as “stay crushing process”). According to such a bumper structure, it is possible to increase the absorption amount of collision energy while keeping the peak of the collision load transmitted to the vehicle body low, so that a malfunction of a safety device (for example, an air bag) at the time of a light collision can be prevented. Damage to the car body can be mitigated while preventing. In the beam bending process in the bumper reinforcement having the bent part or the curved part, the collision energy is absorbed even in the process of extending the bent part or the curved part in a straight line.

  Patent Document 3 discloses a technique for absorbing collision energy by arranging a cylindrical bumper stay so that the hollow portion thereof is continuous in the longitudinal direction of the vehicle body and crushing the bumper stay in the longitudinal direction of the vehicle body. Yes.

International Publication No. 2007/110938 Pamphlet International Publication No. 2009/110461 Pamphlet JP 2009-280145 A

  When the action position of the collision load is offset above or below the center line of the bumper reinforcement, the collision load is concentrated on the upper part or the lower part of the bumper stay. When this bumper stay is used, local buckling may occur in the cylindrical portion of the bumper stay in the initial stage of the collision. If local buckling occurs in the cylindrical part of the bumper stay, the bumper reinforcement will be greatly twisted, resulting in the phenomenon that the bumper reinforcement gets under the collision partner or climbs onto the collision partner. Therefore, energy absorption in the beam bending process may be reduced.

  From such a viewpoint, an object of the present invention is to provide a bumper stay capable of stably absorbing collision energy.

  The present invention that solves the above problems is a bumper structure including a hollow bumper reinforcement and a bumper stay that supports the bumper reinforcement, and the bumper stay has a hollow portion that is continuous in a vehicle longitudinal direction. The stay body has an outer shell of the hollow portion and a pair of upper and lower flanges protruding from the outer shell, and the outer shell has the same height as the upper surface portion of the bumper reinforcement. A pair of left and right upper ridge lines positioned at the same height and a pair of left and right lower ridge lines positioned at the same height as the lower surface of the bumper reinforcement, the upper ridge line and the lower side closer to the center of the vehicle body When the plane passing through the ridge portion is an inner reference plane, the flange protrudes toward the vehicle body center side from the inner reference plane, and the bumper Emissions reinforcement, the outer shell and is joined to said flange, characterized in that.

  Since the collision load applied to the bumper reinforcement is received by the bumper stay, a reaction force equivalent to the load applied to the bumper stay is applied to the bumper reinforcement. When the collision load is large (that is, when the reaction force from the bumper stay is large), the bumper reinforcement will be crushed and thereby absorb the collision energy. However, according to the bumper structure of the present invention, For example, the bumper reinforcement is crushed not only by the reaction force received from the outer shell of the hollow part but also by the reaction force received from the upper and lower flanges, so that the bumper reinforcement is crushed compared to the case where no flange is provided. It is possible to increase the range, and thus increase the amount of collision energy absorbed.

  In addition, when the impact load action position is offset vertically, buckling tends to occur in one of the upper and lower flanges, but as a result of the concentration of buckling in one flange, the buckling start timing of the outer shell is delayed. Therefore, it is possible to stably support the bumper reinforcement at least in the initial stage of the collision. That is, according to the bumper structure according to the present invention, it is possible to stably support the bumper reinforcement even when the action position of the collision load is offset up and down. It is possible to alleviate the occurrence of the phenomenon of sneaking underneath and the phenomenon of climbing on to the collision partner, and as a result, energy absorption in the beam bending process can be expected.

  In addition, when the four ridge lines of the outer shell (a pair of left and right upper ridge lines and a pair of left and right lower ridge lines) are adjusted to the height positions of the upper surface portion and the lower surface portion of the bumper reinforcement, In comparison, since the beam crushing process is difficult to proceed, the beam bending process and the beam crushing process proceed with a time difference. That is, since the peak of the collision load transmitted to the vehicle body appears sequentially with a time difference, the collision energy can be effectively absorbed.

  The upper flange may be positioned at the same height as the upper surface portion, and the lower flange may be positioned at the same height as the lower surface portion. In this case, the phenomenon that the bumper reinforcement is torn off by the flange is less likely to occur, so that the collision energy can be stably absorbed.

  When the central part in the height direction of the inner wall of the outer shell (the part from the upper ridge line part closer to the vehicle body center to the lower ridge line part) is protruded to the vehicle body center side than the inner reference surface, The bumper reinforcement may be joined to the central portion of the inner wall. In this way, the range of cross-sectional crushing that occurs in bumper reinforcement can be increased, so that the amount of energy absorption in the beam crushing process can be increased.

  You may form the recessed part dented in the said hollow part side in the said inner wall, or the opening part which leads to the said hollow part. If it does in this way, it will become possible to control the starting position of buckling when crushing the outer shell of the hollow part of a bumper stay. Further, since the rigidity of the inner wall is lowered, it is possible to suppress the peak of the collision load transmitted to the vehicle body.

  At least a part of the upper wall of the outer shell (the portion extending from one upper ridge line portion to the other upper ridge line portion) protrudes below the upper reference plane (a plane passing through the pair of upper ridge line portions). And at least a part of a lower wall of the outer shell (a portion from one lower ridge line portion to the other lower ridge line portion), a lower reference plane (a plane passing through the pair of lower ridge line portions) It is better to protrude upwards. This increases the rigidity of the upper and lower walls of the outer shell, so that even if the action position of the collision load is offset up and down, local buckling hardly occurs in the outer shell. Bumper reinforcement can be stably supported.

  When the outer wall of the outer shell (the portion connecting the upper ridge line portion and the lower ridge line portion near the vehicle body side surface) is bent at at least one position in the height direction, and the bumper reinforcement is joined to the outer wall. Good. If it does in this way, since it becomes possible to increase the contact length of bumper reinforcement and a bumper stay, it becomes possible to increase joining length (for example, welding length).

  Another bumper structure according to the present invention that solves the above-mentioned problems is a bumper structure comprising a hollow bumper reinforcement and a bumper stay that supports the bumper reinforcement, the bumper stay being arranged in the longitudinal direction of the vehicle body. A stay main body formed with a continuous hollow portion, and an outer shell of the hollow portion includes a pair of left and right upper ridges positioned at the same height as the upper surface portion of the bumper reinforcement, and a lower surface of the bumper reinforcement The stay main body has a pair of left and right lower ridge lines positioned at the same height as the section, and a plane passing through the upper ridge line and the lower ridge line near the center of the vehicle body is defined as an inner reference plane. A portion projecting toward the center of the vehicle body from the inner reference surface, and at least the portion is joined to the bumper reinforcement. And which is characterized in that.

  In this way, when the beam crushing process progresses, the protrusion of the stay body (the part protruding toward the center of the vehicle body from the inner reference surface) is pushed into the bumper reinforcement, so the cross section of the bumper reinforcement It is possible to increase the range of crushing. That is, it is possible to increase the amount of energy absorption in the beam crushing process, and consequently, it is possible to stably absorb the collision energy.

  The bumper structure according to the present invention may be applied to a front bumper or a rear bumper.

  According to the present invention, collision energy can be stably absorbed.

It is a disassembled perspective view of the bumper structure which concerns on embodiment of this invention. (A) is the expansion exploded perspective view which looked at the bumper structure of Drawing 1 from the back side, and (b) is a top view of a bumper structure. (A) is the XX sectional view taken on the line of (b) of FIG. 2, (b) is a figure which shows the position of a reference plane. It is sectional drawing which shows the junction location of bumper reinforcement and a bumper stay. (A) is a plan view showing the bumper structure before the collision load is applied, (b) is a plan view showing the beam bending process, (c) is a plan view showing the beam crushing process, and (d) is a stay crushing process. FIG. It is a top view which shows the modification of bumper reinforcement. It is sectional drawing which shows the modification of a bumper stay.

  The bumper structure according to the embodiment of the present invention is applied to a front bumper. As shown in FIG. 1, a hollow bumper reinforcement R and a pair of left and right bumper stays S and S that support the bumper reinforcement R are provided. And.

  In the present embodiment, “front and rear”, “left and right”, and “up and down” are based on a state in which the bumper structure is attached to the vehicle body.

  The bumper reinforcement R is a member that is installed in front of the vehicle body, and is supported by side members M and M that are part of the vehicle body via bumper stays S and S. The center in the longitudinal direction of the bumper reinforcement R is located in the center of the vehicle body, and the end in the longitudinal direction of the bumper reinforcement R is located in the vicinity of the side surface of the vehicle body. The bumper reinforcement R is hollow and has a rectangular tube shape. That is, the bumper reinforcement R has a hollow portion having a rectangular cross section that is continuous in the vehicle body width direction (the left-right direction of the vehicle body). The upper surface portion 11, the lower surface portion 12, the front surface portion 13, and the outer skin of the hollow portion A rear surface portion 14 is provided. The upper surface portion 11 and the lower surface portion 12 are parallel to each other and are opposed to each other with an interval in the vertical direction. The front surface portion 13 connects the front edges of the upper surface portion 11 and the lower surface portion 12. The rear surface portion 14 is a portion that connects the rear edges of the upper surface portion 11 and the lower surface portion 12, and faces the front surface portion 13 in parallel.

  The illustrated bumper reinforcement R is curved so as to protrude forward, and both ends of the bumper reinforcement R are inclined toward the vehicle body side (rear). Such bumper reinforcement R can be obtained by bending an aluminum alloy hollow extruded shape.

  The bumper reinforcement R absorbs collision energy in the process of extending the curved portion in a straight line (hereinafter referred to as “beam bending process”) and also has an outer skin (upper surface portion 11, lower surface portion) in a region adjacent to the bumper stay S. 12, the front surface portion 13 and the rear surface portion 14) absorb the collision energy in the process in which buckling or plastic deformation occurs (hereinafter referred to as “beam crushing process”). In the present embodiment, the bending rigidity of the entire bumper reinforcement R is set so that the beam crushing process proceeds after the beam bending process proceeds.

  Incidentally, it is mainly the bending stiffness of the entire bumper reinforcement R that affects the start / end timing of the beam bending process. The bending stiffness is adjusted by increasing or decreasing the cross-sectional secondary moment. The impact on the magnitude of the moment of inertia of the bumper reinforcement R is mainly due to the thickness of the front surface portion 13 and the rear surface portion 14 and the distance between the front surface portion 13 and the rear surface portion 14. Therefore, by increasing or decreasing these, the start / end timing of the beam bending process can be adjusted. On the other hand, the influence on the start / end timing of the beam crushing process is mainly due to the thickness of the upper surface portion 11 and the lower surface portion 12 and the distance between the front surface portion 13 and the rear surface portion 14. By increasing or decreasing these, the start / end timing of the beam crushing process can be adjusted.

Bumper stay S is intended to be interposed between the longitudinal edges and the side member M of the bumper reinforcement R, and stay base S _B to be joined to the side members M, joined to the bumper reinforcement R and a stay body S _M being. The stay body S _M, hollow portion H continuous in the vehicle longitudinal direction is formed.

Stay base S _B is a member interposed between the stay body S _M and the side member M, it is welded to the rear end of the stay body S _M. Contour of the stay base S _B is located on the outer peripheral side of the rear end of the contour of the stay body S _M. Stay base periphery of S _B (the portion projecting to the outer periphery side of the stay body S _M) is a bolt insertion holes 2a, 2a, ... are formed. A bolt insertion hole 2a is stay based S _B the side members M bolts for fastening the front end surface of the (not shown) is inserted.

Stay-based S _B of the present embodiment includes a flat plate portion 21 which is butted to a front end of the side member M, and a tongue portion 22 which is along the upper surface of the side member M. The tongue portion 22 projects rearward from the upper end portion of the flat plate portion 21 and is orthogonal to the flat plate portion 21. Tongue 22 is formed by bending a portion of the aluminum alloy plate serving as the elements of the stay base S _B.

The stay main body _SM is made of an aluminum alloy hollow extruded shape (hollow shape), and is arranged in such a direction that the extrusion direction of the hollow extruded shape is the front-rear direction. Front opening of the hollow portion H is closed by the bumper reinforcement R, side of the opening after the hollow portion H is closed by the stay base S _B.

As shown also in FIG. 2, the stay main body _SM includes an outer shell 3 of the hollow portion H and a pair of upper and lower flanges 4 and 4 projecting from the outer shell 3.

  As shown in FIG. 3A, the outer shell 3 is a cylindrical portion formed by an upper wall 31, a lower wall 32, an inner wall 33 and an outer wall 34, and a pair of left and right upper ridge lines 3a, 3b and And a pair of left and right lower ridge lines 3c and 3d. The cross-sectional shape of the outer shell 3 is vertically symmetric.

  The upper ridge lines 3a and 3b are located at the same height as the upper surface 11 of the bumper reinforcement R. The upper ridge line portion 3a closer to the center of the vehicle body is an intersection (corner portion) between the upper wall 31 and the inner wall 33, and is continuous in the vehicle longitudinal direction (the direction perpendicular to the plane of FIG. 3). The upper ridge line portion 3b near the side surface of the vehicle body is an intersection (corner portion) between the upper wall 31 and the outer wall 34, and is continuous in the longitudinal direction of the vehicle body. The inner angle of the outer shell 3 in the upper ridge line portion 3a is an obtuse angle, and the inner angle of the outer shell 3 in the upper ridge line portion 3b is an acute angle.

  The lower ridge lines 3c and 3d are located at the same height as the lower surface 12 of the bumper reinforcement R. The lower ridge line portion 3c near the center of the vehicle body is an intersection (corner portion) between the lower wall 32 and the inner wall 33, and is continuous in the vehicle longitudinal direction (the direction perpendicular to the plane of FIG. 3A). The lower ridge line portion 3d near the vehicle body side surface is an intersection (corner portion) between the lower wall 32 and the outer wall 34, and is continuous in the longitudinal direction of the vehicle body. The inner angle of the outer shell 3 at the lower ridge line portion 3c is an obtuse angle, and the inner angle of the outer shell 3 at the lower ridge line portion 3d is an acute angle.

  As shown in FIG. 3B, the plane passing through the pair of upper ridge line portions 3a and 3b is referred to as “upper reference plane P1,” and the plane passing through the pair of lower ridge line portions 3c and 3d is referred to as “lower reference plane. Surface P2 ". Further, a plane passing through the upper ridge line portion 3a and the lower ridge line portion 3c near the center of the vehicle body is defined as an “inner reference plane P3”, and a plane passing through the upper ridge line portion 3b and the lower ridge line portion 3d near the vehicle body side is defined as an “outer reference plane”. P4 ".

  The upper wall 31 is a part extending from one upper ridge line portion 3a to the other upper ridge line portion 3b. The left and right ends of the upper wall 31 are located on the upper reference plane P1, and the other portions protrude below the upper reference plane P1. That is, the left and right end portions of the upper wall 31 are positioned at the same height as the upper surface portion 11 of the bumper reinforcement R as shown in FIG. It has a cross-sectional shape that is convex. In addition, although the center part of the upper wall 31 comprises the shape which connected the four strip | belt plate parts in the shape of a broken line, it is good also as a shape which connected the two strip | belt plate parts in the cross-section V shape, or cross-section arc shape. A curved shape may be used.

  The lower wall 32 is a part from one lower ridge line portion 3c to the other lower ridge line portion 3d. As shown in FIG. 3B, the left and right ends of the lower wall 32 are located on the lower reference plane P2, and the other portions protrude above the lower reference plane P2. That is, as shown in FIG. 3A, the left and right end portions of the lower wall 32 are located at the same height as the lower surface portion 12 of the bumper reinforcement R, and the central portion of the lower wall 32 is on the upper side. It has a cross-sectional shape that is convex. The cross-sectional shape of the lower wall 32 is the same as the shape in which the upper wall 31 is turned upside down.

  The inner wall 33 is a portion from the upper ridge line portion 3a closer to the vehicle body center to the lower ridge line portion 3c, and protrudes toward the vehicle body center side from the inner reference plane P3 as shown in FIG. The inner wall 33 includes a flat plate portion 33a parallel to the inner reference plane P3, an upper inclined portion 33b extending from the upper edge of the flat plate portion 33a to the upper ridge line portion 3a, and a lower surface extending from the lower edge of the flat plate portion 33a to the lower ridge line portion 3c. And an inclined portion 33c. The flat plate portion 33 a is located at the center in the height direction of the inner wall 33. The upper inclined portion 33b and the lower inclined portion 33c are inclined with respect to the flat plate portion 33a and are opposed to each other in a cross-sectional horizontal C shape. The cross-sectional shape of the lower inclined portion 33c is the same as the shape obtained by inverting the upper inclined portion 33b up and down. Each of the upper inclined portion 33b and the lower inclined portion 33c has a polygonal cross-sectional shape bent at two points in the height direction, but may have a cross-sectional shape curved in an arc shape or a bending point. It is good also as a linear cross-sectional shape which does not have.

  As shown in FIG. 2A, an opening 33 d that communicates with the hollow portion H is formed in the inner wall 33. The opening 33d is formed for the purpose of reducing the crushing load (peak load) of the outer shell 3, and the one according to the present embodiment has an oval shape. This makes it possible to control the buckling start position when the outer shell 3 is crushed. In addition, since the rigidity of the inner wall 33 is reduced, it is possible to suppress the peak of the collision load transmitted to the vehicle body. In addition, you may change suitably the shape and position of the opening part 33d. Although illustration is omitted, of course, a plurality of openings may be formed.

  As shown in FIG. 3B, the outer wall 34 is a portion from the upper ridge line portion 3b near the vehicle body side surface to the lower ridge line portion 3d, and protrudes toward the vehicle body center side from the outer reference surface P4. The outer wall 34 includes a flat plate portion 34a parallel to the outer reference plane P4, an upper inclined portion 34b extending from the upper edge of the flat plate portion 34a to the upper ridge line portion 3b, and a lower surface extending from the lower edge of the flat plate portion 34a to the lower ridge line portion 3d. And an inclined portion 34c. The flat plate portion 34 a is located at the center in the height direction of the outer wall 34. The lower inclined portion 34b and the lower inclined portion 34c are inclined with respect to the flat plate portion 34a and are opposed to each other in a cross-sectional horizontal C shape. The cross-sectional shape of the lower inclined portion 34c is the same as the shape obtained by inverting the upper inclined portion 34b up and down. Each of the upper inclined portion 34b and the lower inclined portion 34c has a linear cross-sectional shape that does not have a bending point. Alternatively, a cross-sectional shape curved in an arc shape may be used.

  The flanges 4 and 4 protrude toward the center of the vehicle body from the inner reference plane P3. As shown in FIG. 3A, the upper flange 4 protrudes in a cantilevered manner from the upper ridge line portion 3 a of the outer shell 3 to the side, and is the same height as the upper surface portion 11 of the bumper reinforcement R. Is located. The lower flange 4 protrudes sideways from the lower ridge line portion 3c of the outer shell 3 and is positioned at the same height as the lower surface portion 12 of the bumper reinforcement R. Note that the upper and lower flanges 4 and 4 are arranged in parallel and are formed in the same planar shape (see FIG. 2A).

As shown in (b) of FIG. 2, the flange 4, in order to reduce the weight, it is formed only on the front of the stay body S _M. The front edge of the flange 4 is joined to the bumper reinforcement R.

Is not limited to the planar shape of the flange 4, the flange 4 of the present embodiment, and the wide portion 4a of the substantially trapezoidal shape which is connected to the bumper reinforcement R, Zhang from the upper ridge portion 3a toward the stay base S _B And a substantially triangular width changing portion 4b formed so that the amount of protrusion is small. As shown to (a) of FIG. 3, the side end (free end) of the wide part 4a is located in the vehicle body center side rather than the plane which passes along the flat plate part 33a. Although not shown, to form a flange over the entire length of the stay body S _M, may be joined to the rear end of the flange to stay base S _B.

In order to form the flange 4, in extruded profile as the elements of the stay body S _M, it may be excised plate portion serving as elements of the flange 4.

When joining the bumper stay S in the bumper reinforcement R is, after is brought into contact with the front end of the stay body S _M to the rear surface of the bumper reinforcement R, as shown in FIG. 4, the upper and lower surfaces of the flange 4 along with performing welding W _41, W ₄₂ along, subjected to the upper wall 31, the weld W ₃₁ along the outer surface of the lower wall 32 and outer wall 34, W _32, W ₃₄ continuously, further, the flat portion of the inner wall 33 it may be subjected to welding W ₃₄ along the outer surface of 33a.

  Although not shown, the bumper stay S may be joined to the bumper reinforcement R by friction stir welding or mechanical joining means such as a bolt or rivet.

  Next, the collision energy absorption process at the time of a frontal collision will be described with reference to FIG. In the present embodiment, the bumper stay S and the bumper reinforcement R so that the “stay crushing process” proceeds in the bumper stay S after the “beam bending process” and the “beam crushing process” proceed in the bumper reinforcement R. The rigidity (thickness of each part, cross-sectional dimensions, etc.) is set.

  When a collision load in the front-rear direction of the vehicle body acts on the bumper structure shown in FIG. 5A from the front side (front of the vehicle body), first, as shown in FIG. When the curved portion of the bumper reinforcement R is stretched in a straight line, the collision energy is absorbed (beam bending process). In addition, since the collision load which acted on bumper reinforcement R is received by bumper stay S, reaction force from bumper stay S acts on bumper reinforcement R.

  When the curved part of the bumper reinforcement R is stretched in a straight line, the flanges 4 and 4 are buckled, but as a result of the buckling being concentrated on the flanges 4 and 4, the outer shell 3 is prevented from being crushed or overturned. Therefore, the bumper stay S can stably support the bumper reinforcement R during the beam bending process.

  In particular, in the present embodiment, the four ridge lines 3a to 3d and the flanges 4 and 4 of the outer shell 3 are adjusted to the height positions of the upper surface 11 and the lower surface 12 of the bumper reinforcement R (see FIG. 3). The bumper stay S is unlikely to be reduced to the bumper reinforcement R, and therefore the bumper reinforcement R during the beam bending process can be stably supported.

  In addition, when the action position of the collision load is offset up and down, the flange 4 on the offset side is likely to buckle. However, as a result of the buckling being concentrated on the flange 4, the buckling start time of the outer shell 3 is increased. Therefore, even when the collision position is offset up and down, the bumper reinforcement R can be stably supported at least in the initial stage of the collision. In addition, in the present embodiment, the upper wall 31 of the outer shell 3 protrudes below the upper reference plane P1, and the lower wall 32 protrudes above the lower reference plane P2 (FIG. 3). (B)), the upper wall 31 and the lower wall 32 have high rigidity, and even if the action position of the collision load is offset up and down, local buckling hardly occurs in the outer shell 3, and as a result, bumper reinforcement It is possible to stably support the ment R.

  When the collision energy cannot be absorbed only by the beam bending process (when the collision load is large), the sectional deformation of the bumper reinforcement R proceeds in a region adjacent to the bumper stay S as shown in FIG. Start (beam crushing process). That is, when the beam bending process reaches the final stage or the beam bending process is finished, the beam crushing process starts to proceed, the bumper stay S is reduced to the bumper reinforcement R, and the internal space of the bumper reinforcement R is crushed. To absorb the collision energy. If the bumper stay S is reduced to the bumper reinforcement R after the curved part of the bumper reinforcement R is straightened, the peak of the collision load transmitted to the side member M during the beam bending process and the beam crushing process will occur. The peak of the collision load transmitted to the side member M appears with a time difference.

  The bumper stay S includes the outer shell 3 and the upper and lower flanges 4 and 4, and the bumper reinforcement R is supported not only by the outer shell 3 but also by the flanges 4 and 4. The bumper reinforcement R is crushed not only by the reaction force received but also by the reaction force received from the upper and lower flanges 4 and 4. That is, although the flange 4 is buckled during the beam bending process, the force (reaction force of the collision load) for crushing the hollow portion of the bumper reinforcement R is not limited to the contact portion with the outer shell 3, but the flange 4 and 4, the bumper reinforcement R can be crushed in an increased range compared to the case where the flanges 4 and 4 are not provided. It is possible to increase the amount of absorption.

  In the present embodiment, since the inner wall 33 of the outer shell 3 is convex, the convex portion of the inner wall 33 is pushed into the rear surface portion 12 in the beam crushing process. That is, in the beam crushing process, the rear surface portion 12 is deformed in a wide range, and as a result, the amount of energy absorption in the beam crushing process can be increased.

  If the upper flange 4 is shifted to the lower side of the upper surface part 11 or the lower flange 4 is shifted to the upper side of the lower surface part 12, the bumper reinforcement is applied during the beam bending process or the beam crushing process. Although the rear surface portion 14 of the ment R may be torn by the flange 4, if the height positions of the flanges 4, 4 are matched to the upper surface portion 11 and the lower surface portion 12, the tearing phenomenon due to the flange 4 is difficult to occur. It is possible to stably absorb the collision energy in the beam bending process and the beam crushing process.

  If the collision energy cannot be absorbed even though the beam crushing process proceeds, the outer shell 3 starts to crush in the front-rear direction (stay crushing process). That is, when the beam crushing process reaches the end stage or when the beam crushing process ends, the stay crushing process starts to proceed as shown in FIG. Absorb energy. When the outer shell 3 of the bumper stay S is crushed after the bumper stay S is reduced to the bumper reinforcement R, the peak of the collision load transmitted to the side member M during the beam crushing process and the side member M during the stay crushing process. The peak of the collision load transmitted to the surface appears with a time difference.

  Thus, according to the bumper structure of the present embodiment, at least in the case of a frontal collision, the beam bending process, the beam crushing process, and the stay crushing process proceed sequentially, so that the collision load peaks sequentially with a time difference. Appears. Therefore, according to the bumper structure of the present embodiment, it is possible to maintain the load value by preventing the collision load from greatly decreasing after the collision load is increased.

  Further, not only the reaction force received from the outer shell 3 but also the reaction force received from the upper and lower flanges 4 and 4 causes the bumper reinforcement R to be crushed. Compared to the case where the flanges 4 and 4 are not provided, It is possible to increase the crushing range of the bumper reinforcement R, and consequently increase the amount of collision energy absorbed.

  In addition, even when the position of the collision load is offset up and down, the bumper reinforcement R can be stably supported, so that the phenomenon that the bumper reinforcement R sinks under the collision partner or the collision partner It is possible to alleviate the occurrence of the phenomenon of climbing the beam, and as a result, energy absorption in the beam bending process can be expected.

  According to the bumper structure of the present embodiment, both the bumper stay S and the bumper reinforcement R are formed of an extruded shape made of an aluminum alloy, so that it is possible to reduce the weight and cost of the bumper structure B. In addition, the manufacture is facilitated and the quality is stabilized.

  According to the bumper structure of the present embodiment, since the distance between the fulcrums of the bumper reinforcement R is reduced by the flanges 4 and 4, the thickness of the front surface portion 13 and the rear surface portion 14 of the bumper reinforcement R is reduced and the weight is reduced. However, the deformation resistance of the bumper reinforcement R is not greatly reduced, and therefore the amount of collision energy absorbed in the beam bending process is not greatly reduced. That is, according to the bumper structure of the present embodiment, it is possible to reduce the thickness of the bumper reinforcement R without reducing the deformation resistance of the bumper reinforcement R between the bumper stays S and S. It is possible to reduce the weight without reducing the amount of collision energy absorbed in the process. If the thickness of the front surface portion 13 and the rear surface portion 14 of the bumper reinforcement R is reduced without reducing the distance between the fulcrums, the bumper reinforcement R can be reduced in weight while the bending rigidity of the bumper reinforcement R is reduced. As a result, the deformation resistance of the bumper reinforcement R decreases, and the amount of collision energy absorbed in the beam bending process may decrease.

(Modified example of bumper reinforcement)
In the present embodiment, the bumper reinforcement R having an arc shape (a shape in which the curvature is constant regardless of the place) is exemplified, but the shape of the bumper reinforcement applicable to the present invention is not limited. Although not shown, bumper reinforcement that forms an elliptical arc or a parabola may be used, or bumper reinforcement that has a combination of multiple arcs with different curvatures or a combination of curves and straight lines may be used. Good.

  Further, as shown in FIG. 6, a bumper reinforcement R ′ having two bent portions Rs and Rs between the bumper stays S and S may be used. In the form of FIG. 6, the bent energy Rs, Rs of the bumper reinforcement R ′ is linearly extended, so that the collision energy at the initial stage of the collision is absorbed.

  Although illustration is omitted, a bumper reinforcement having a linear shape may be used. In this case, in the bumper reinforcement, the collision energy at the initial stage of the collision is absorbed by bending (bending deformation) so that the portion between the left and right bumper stays is convex toward the vehicle body.

(Bumper stay modification)
The bumper stay shown in FIG. 7 has a stay body S _M ′ in which a hollow portion H is formed. The stay body S _M ′ includes a portion (the inner wall 53 of the outer shell 3 and the flanges 6 and 6) that protrudes toward the center of the vehicle body from the inner reference plane P3, and at least the portion is a bumper reinforcement (not shown). It is joined to.

The stay body S _M ′ includes an outer shell 5 of the hollow portion H, a pair of upper and lower flanges 6, 6 projecting from the upper ridge line portion 5 a and the lower ridge line portion 5 c of the outer shell 5 near the vehicle body center, A pair of upper and lower fins 7 and 7 projecting from the upper ridge line portion 5b and the lower ridge line portion 5d near the vehicle body side surface are provided.

  The outer shell 5 is a cylindrical portion formed by the upper wall 51, the lower wall 52, the inner wall 53 and the outer wall 54. The cross-sectional shape of the outer shell 5 is vertically symmetric.

  The upper ridge lines 5a and 5b are positioned at the same height as the upper surface of the bumper reinforcement (not shown), and the lower ridge lines 5c and 5d are at the same height as the lower surface of the bumper reinforcement. positioned. The inner angle of the outer shell 5 at the upper ridge line portions 5a and 5b and the inner angle of the outer shell 5 at the lower ridge line portions 5c and 5d are both obtuse. If the four ridges 5a to 5d of the outer shell 5 are aligned with the height positions of the upper surface and the lower surface of the bumper reinforcement, the beam crushing process is less likely to proceed than when shifted from these. The beam bending process and the beam crushing process proceed with a time difference. That is, since the peak of the collision load transmitted to the vehicle body appears sequentially with a time difference, the collision energy can be effectively absorbed.

  The upper wall 51 and the lower wall 52 have a flat plate shape. The upper wall 51 is located on the upper reference surface (not shown), and the lower wall 52 is located on the lower reference surface (not shown).

  The inner wall 53 protrudes toward the center of the vehicle body from the inner reference plane P3. The inner wall 53 is formed with a recess 53d that is recessed toward the hollow portion H. The recess 53d is formed for the purpose of reducing the crushing load (peak load) of the outer shell 5. If it does in this way, it will become possible to control the buckling start position at the time of crushing the outer shell 5. In addition, since the rigidity of the inner wall 53 is reduced, it is possible to suppress the peak of the collision load transmitted to the vehicle body. Although illustration is omitted, the cross-sectional shape of the inner wall 53 before and after the concave portion 53d is the same as the shape in which the outer wall 54 is reversed left and right. The shape and position of the recess 53d may be changed as appropriate. Although illustration is omitted, of course, a plurality of recesses may be formed.

  The outer wall 54 is bent at two locations in the height direction, and protrudes more to the vehicle body side surface than the outer reference surface P4.

  The flanges 6 and 6 protrude toward the center of the vehicle body from the inner reference plane P3. The upper flange 6 projects in a cantilevered manner from the upper ridge portion 5a of the outer shell 3 to the side, and is located at the same height as the upper surface portion of the bumper reinforcement (not shown). The lower flange 6 protrudes sideways from the lower ridge line portion 5c of the outer shell 5 and is located at the same height as the lower surface portion of the bumper reinforcement. The upper and lower flanges 6 and 6 are arranged in parallel and are formed in the same planar shape.

  The fins 7, 7 protrude from the outer reference surface P4 toward the side of the vehicle body. The upper fin 7 projects in a cantilevered manner from the upper ridge line portion 5b of the outer shell 5 toward the side, and is located at the same height as the upper surface portion of the bumper reinforcement (not shown). The lower fins 7 project in a cantilevered manner from the lower ridge line part 5d of the outer shell 5 and are positioned at the same height as the lower surface part of the bumper reinforcement. Note that the upper and lower fins 7, 7 are arranged in parallel and are formed in the same planar shape.

  Although not shown, both the flange 6 and the fin 7 have a length from the bumper reinforcement to the stay base. The front end edges of the flange 6 and the fin 7 are joined to the bumper reinforcement, and the rear end edges of the flange 6 and the fin 7 are joined to the stay base.

  According to the bumper structure having such a bumper stay, the bumper reinforcement is crushed not only by the reaction force received from the outer shell 5 but also by the reaction force received from the flanges 6 and 6 and the fins 7 and 7. Therefore, compared to the case where the flanges 6 and 6 and the fins 7 and 7 are not provided, it is possible to increase the crushing range of the bumper reinforcement, and thus increase the amount of collision energy absorbed.

  Further, when the action position of the collision load is offset vertically, buckling is likely to occur in one of the upper and lower flanges 6, 6, but as a result of the concentration of buckling in one flange 6, the seat of the outer shell 5 is seated. Since the bending start time can be delayed, the bumper reinforcement can be stably supported at least in the initial stage of the collision even when the collision position is offset up and down. In other words, according to the bumper structure provided with this bumper stay, it is possible to stably support the bumper reinforcement even when the action position of the collision load is offset up and down. It is possible to alleviate the occurrence of the phenomenon of sinking under the opponent and the phenomenon of climbing to the opponent, and as a result, energy absorption in the beam bending process can be expected.

(Other modified bumper stays)
Although not shown, e.g., in the bumper stay S illustrated in FIGS. 2 and 3 may be omitted flanges 4,4 of the stay body S _M. Even in this case, the stay main body has a portion (the flat plate portion 33a of the inner wall 33) protruding toward the vehicle body center side from the inner reference surface, and the portion (the flat plate portion 33a) is joined to the bumper reinforcement R. Therefore, in the beam crushing process, the rear surface portion 12 of the bumper reinforcement R is deformed in a wide range, and as a result, the amount of energy absorption in the beam crushing process can be increased.

R bumper reinforcement 11 upper surface 12 lower surface portion S bumper stay S _M Stay body H hollow portion 3 shell 3a, 3b upper ridge portion 3c, 3d lower ridge part 31 upper wall 32 bottom wall 33 inner wall 34 outer wall 33d opening 4 Flange S _B Stay Base

R 'bumper reinforcement S _M' stay body 5 shell 5a, 5b upper ridge portion 5c, 5d lower ridge part 51 upper wall 52 bottom wall 53 inner wall 54 outer wall 53d recess 6 flange

Claims (7)

Hollow bumper reinforcement,
A bumper stay that supports the bumper reinforcement, and a bumper structure comprising:
The bumper stay has a stay body formed with a hollow portion continuous in the longitudinal direction of the vehicle body,
The stay body has an outer shell of the hollow portion and a pair of upper and lower flanges projecting from the outer shell,
The outer shell includes a pair of left and right upper ridges positioned at the same height as the upper surface of the bumper reinforcement, and a pair of left and right lower ridges positioned at the same height as the lower surface of the bumper reinforcement. Have
When a plane passing through the upper ridge line part and the lower ridge line part near the center of the vehicle body is defined as an inner reference plane,
The flange protrudes toward the vehicle body center side from the inner reference surface,
The bumper reinforcement is characterized in that the bumper reinforcement is joined to the outer shell and the flange. The upper flange is located at the same height as the upper surface part,
The bumper structure according to claim 1, wherein the lower flange is located at the same height as the lower surface portion. The outer shell has an inner wall from the upper ridge line portion near the vehicle body center to the lower ridge line portion near the vehicle body center,
The central portion of the inner wall in the height direction protrudes toward the vehicle body center side from the inner reference surface,
The bumper structure according to claim 1, wherein the bumper reinforcement is joined to the central portion of the inner wall.   The bumper structure according to any one of claims 1 to 3, wherein the inner wall is formed with a recess that is recessed toward the hollow portion or an opening that communicates with the hollow portion. . The outer shell has an upper wall from one upper ridge line part to the other upper ridge line part, and a lower wall from one lower ridge line part to the other lower ridge line part,
When a plane passing through the pair of upper ridge lines is an upper reference plane, and a plane passing through the pair of lower ridge lines is a lower reference plane,
At least a part of the upper wall protrudes below the upper reference surface,
The bumper structure according to any one of claims 1 to 4, wherein at least a part of the lower wall protrudes upward from the lower reference surface. The outer shell has an outer wall from the upper ridge line portion near the vehicle body side to the lower ridge line portion near the vehicle body side surface,
The outer wall is bent at at least one point in its height direction;
The bumper structure according to any one of claims 1 to 4, wherein the bumper reinforcement is joined to the outer wall. Hollow bumper reinforcement,
A bumper stay that supports the bumper reinforcement, and a bumper structure comprising:
The bumper stay has a stay body formed with a hollow portion continuous in the longitudinal direction of the vehicle body,
The outer shell of the hollow part is a pair of left and right upper ridge lines positioned at the same height as the upper surface part of the bumper reinforcement, and a pair of left and right lower ridge lines positioned at the same height as the lower surface part of the bumper reinforcement. And
When a plane passing through the upper ridge line part and the lower ridge line part near the center of the vehicle body is defined as an inner reference plane,
The stay main body has a portion protruding toward the center of the vehicle body from the inner reference surface, and at least the portion is joined to the bumper reinforcement.

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