JP2009101744A - Vehicle bumper structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle bumper structure capable of restricting a bending moment acted against a side rail even if a load is inputted to the end part of a vehicle body from a slant direction in respect to the forward or rearward direction of the vehicle body. <P>SOLUTION: A displacement restricting unit 30 provided with rotating rollers 34 is arranged at a side of a rear cross member 22 that is the rear side of a vehicle body, and installed at a vehicle width oriented position more inside of the vehicle width direction than that of an inner ridge line 16A of a side rail 16 as seen in a top plan view of a vehicle. In the case that a barrier 52 collides from the slant direction (an arrow direction A) in respect to the forward or rearward direction of the vehicle body, a relative position of the rear cross member 22 in respect to the barrier 52 is changed substantially to the vehicle width direction through a rotating force of the rotating rollers 34 to restrict the rear cross member 22 from being displaced toward the vehicle width direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicular bumper structure that includes a cross member that is stretched between ends in a longitudinal direction of a pair of side rails.

  In a bumper part of a vehicle, for example, a structure is known in which bumper reinforcement (cross member) extends substantially in the vehicle width direction on the end side in the longitudinal direction of the vehicle body (see, for example, Patent Document 1). Side members (side rails) extending in the longitudinal direction of the vehicle body are coupled to both ends of such bumper reinforcement.

However, in this structure, when a collision object strikes the bumper portion obliquely and a load is input from an oblique direction with respect to the longitudinal direction of the vehicle body, a bending moment acts on the side member (side rail) and the side member An attempt is made to deform the vehicle body longitudinally intermediate portion so as to protrude outward in the vehicle width direction. For this reason, if the yield strength against the bending moment is not sufficient, the side rail may be bent outward in the vehicle width direction.
Japanese Utility Model Publication No. 6-81846

  In consideration of the above-described facts, the present invention is for a vehicle that can suppress a bending moment acting on a side rail even when a load is input to an end side in the vehicle longitudinal direction from an oblique direction with respect to the vehicle longitudinal direction. The purpose is to obtain a bumper structure.

  The bumper structure for a vehicle according to the first aspect of the present invention spans between the ends in the longitudinal direction of a pair of left and right side rails arranged on both sides in the vehicle width direction of the vehicle body with the longitudinal direction of the vehicle body as the longitudinal direction. A cross member arranged on the end side in the vehicle longitudinal direction with the vehicle width direction as the longitudinal direction, and provided on the vehicle body longitudinal direction outside of the cross member, and in the vehicle plan view than the inner ridge line of the side rail. The cross member is disposed at a vehicle width direction position on the inner side in the direction, and when the collision body collides from an oblique direction with respect to the longitudinal direction of the vehicle body, the relative position of the cross member with respect to the collision body is changed in the vehicle width direction. Displacement suppression means for suppressing displacement in the vehicle width direction.

  According to the vehicle bumper structure of the present invention described in claim 1, the displacement suppression means is provided on the outer side of the cross member in the front-rear direction of the vehicle body, and the vehicle on the vehicle width direction inner side than the inner ridge line of the side rail in the vehicle plan view. Since it is arranged at the position in the width direction, when the collision object collides with the end part in the longitudinal direction of the vehicle body in an oblique direction with respect to the longitudinal direction of the vehicle body, the collision object collides with the displacement suppression means side before the side rail side. To do. For this reason, the load burden of a side rail is reduced compared with the contrast structure which is not provided with a displacement suppression means. At this time, the load due to the collision body from the oblique direction with respect to the longitudinal direction of the vehicle body is transmitted to the cross member via the displacement suppressing means, and then transmitted to the side rail from the cross member. Moment (moment in the direction of bending the side rail to the outside in the vehicle width direction by displacing the end of the side rail on the cross member side) acts, and the vehicle body longitudinal direction intermediate portion of the side rail acts in the vehicle width direction Trying to deform so that it protrudes outward.

  However, when the collision object collides from an oblique direction with respect to the longitudinal direction of the vehicle body, the displacement suppressing means changes the relative position of the cross member with respect to the collision object in the substantially vehicle width direction and displaces the cross member in the vehicle width direction. Therefore, the displacement of the end of the side rail on the cross member side in the vehicle width direction is also suppressed, and a part of the bending moment that should act on the cross member acts on the side rail as an axial force in the vehicle longitudinal direction. To do. Thereby, the load inputted from the oblique direction with respect to the longitudinal direction of the vehicle body is efficiently transmitted to the end side in the longitudinal direction of the vehicle body in the longitudinal direction of the vehicle body.

  A vehicle bumper structure according to a second aspect of the present invention is the vehicle bumper structure according to the first aspect, wherein the displacement suppressing means receives a driving force to move the collision body about the vehicle body up-down direction and about the vehicle body width. A rotating body that rotates in a direction to be displaced inward is provided.

  According to the vehicle bumper structure of the present invention described in claim 2, the rotating body rotates around the axis in the vertical direction of the vehicle body and in a direction to displace the collision body substantially inward in the vehicle width direction by receiving the driving force. Therefore, when the colliding body collides with the rotating body from an oblique direction with respect to the longitudinal direction of the vehicle body, the cross member receives a reaction force from the colliding body side via the rotating rotating body, and the rotating body displaces the colliding body. Attempts to move in the opposite direction to the direction to be attempted. That is, since the cross member tries to displace the cross member in the opposite direction to the cross member in the oblique direction due to the collision load in the oblique direction by the colliding body, the displacement of the cross member in the approximate vehicle width direction. The amount is reduced.

  According to a third aspect of the present invention, there is provided the vehicular bumper structure according to the second aspect, wherein the rotating body has a rigidity against a load input from an oblique direction with respect to the longitudinal direction of the vehicle body. It is characterized by having a high-rigidity rotating part that is higher than the rigidity.

  According to the vehicle bumper structure of the present invention described in claim 3, the rotating body has a high-rigidity rotation in which the rigidity with respect to a load input from an oblique direction with respect to the longitudinal direction of the vehicle body is higher than the rigidity of the cross member with respect to the load. If the colliding body collides with the rotating body from an oblique direction with respect to the longitudinal direction of the vehicle body, the highly rigid rotating portion can be used even when the cross member is absorbing energy while being deformed in the longitudinal direction of the vehicle body. Rotates without deformation to suppress the displacement of the cross member in the approximate vehicle width direction.

  As described above, according to the vehicle bumper structure of the first aspect of the present invention, even if a load is input from the oblique direction with respect to the vehicle body longitudinal direction to the vehicle body longitudinal direction end side, the side rail It has an excellent effect of being able to suppress the bending moment acting on.

  According to the vehicle bumper structure of the second aspect, even if a load is input from the oblique direction with respect to the longitudinal direction of the vehicle body to the end side in the longitudinal direction of the vehicle body, the bending moment acting on the side rail is effective by the rotating body. It has the outstanding effect that it can suppress automatically.

  According to the vehicle bumper structure of the third aspect, even if a load is input from the oblique direction with respect to the longitudinal direction of the vehicle body to the end side in the longitudinal direction of the vehicle body, it acts on the side rail while absorbing energy by the cross member. It has the outstanding effect that the bending moment to suppress can be suppressed with a rotary body.

(Configuration of the embodiment)
A vehicle bumper structure according to an embodiment of the present invention will be described with reference to FIGS. In these drawings, an arrow RE appropriately shown indicates the vehicle rear side, an arrow UP indicates the vehicle upper side, and an arrow IN indicates the vehicle width direction inner side.

  FIG. 1 shows a schematic configuration of a vehicle body rear structure (vehicle structure) 10A including a vehicle bumper structure 12 according to the present embodiment. The vehicle body rear structure 10A has a substantially bilaterally symmetric structure in a plan view of the vehicle, and FIG. 1 shows only the left half in the vehicle width direction. In the present embodiment, the vehicle bumper structure 12 is applied to the rear end portion of the vehicle body in a vehicle 10 having a frame structure (a so-called vehicle with a frame). The vehicle 10 having a frame structure includes a frame (structural member, vehicle frame member) 14 for supporting basic structural components such as an engine, a steering, and a suspension, and a body (not shown) supported on the frame 14 via a rubber mount. ).

  A pair of left and right side rails 16 (vertical members) are disposed on both sides in the vehicle width direction of the vehicle body 11 shown in FIG. The side rail 16 has a closed cross-sectional structure in which the cross-sectional shape cut along the vehicle width direction is a substantially rectangular shape, and the two inner ridge lines 16A and the two outer ridge lines 16B extend in the longitudinal direction of the vehicle body. Exists (see FIG. 2). A pair of left and right side rails 16 span a rear suspension cross member 20 in the vicinity of a rear wheel position 18 in the longitudinal direction of the vehicle, and are arranged with the vehicle width direction as a longitudinal direction. The side rail 16 and the rear suspension cross member 20 are firmly joined by arc welding.

  Further, on the vehicle rear side of the rear suspension cross member 20, a rear cross member 22 (also referred to as a rear bumper reinforcement) as a cross member is stretched between rear end portions 16C in the longitudinal direction of the pair of left and right side rails 16. (See FIG. 2). As shown in FIG. 2, the rear cross member 22 is disposed on the rear end side of the vehicle body (the rear end side of the vehicle longitudinal direction) with the vehicle width direction as the longitudinal direction, and as shown in FIG. It has a closed cross-sectional structure in which the cross-sectional shape cut along the direction is substantially rectangular. As shown in FIGS. 1 and 2, both ends of the rear cross member 22 in the longitudinal direction (vehicle width direction) are gently bent toward the front side of the vehicle, and from the vehicle width direction inner side to the vehicle width direction outer side. The vehicle is slightly inclined toward the front of the vehicle as it goes to. The side rail 16 and the rear cross member 22 are firmly joined by arc welding to form left and right corner portions 14C at the rear end portion of the frame 14.

  Note that the side rail 16, the rear suspension cross member 20, and the rear cross member 22 shown in FIG. 1 are high-strength and high-rigidity members and constitute a part of the frame 14.

  A rear bumper cover 24 made of resin and having elasticity with the vehicle width direction as the longitudinal direction is disposed on the vehicle rear side of the rear cross member 22. The rear bumper cover 24 is disposed at a position separated from the rear cross member 22 by a predetermined distance, covers the rear cross member 22 from the rear side of the vehicle, and constitutes a design surface at the rear end portion of the vehicle. The rear bumper cover 24 is formed with rectangular cutouts 24A on both sides in the vehicle width direction.

  A displacement restraining portion 30 as a displacement restraining means is provided outside the rear cross member 22 on the vehicle body rear side in the vehicle body front-rear direction, and a part of the displacement restraining portion 30 extends from the notch 24A of the rear bumper cover 24 to the vehicle body. It is exposed in a state of protruding backward. Note that the vehicle bumper structure 12 in this embodiment is a structure (cross section structure) of a rear bumper section 50 that includes the rear cross member 22, the rear bumper cover 24, and the displacement suppression section 30. The displacement suppressing portion 30 embedded in the rear bumper portion 50 and partially exposed is located at the vehicle width direction position near the side rail 16 and the inner ridge line 16A of the side rail 16 (at a position near the rear cross member 22). It is disposed at a position in the vehicle width direction on the inner side in the vehicle width direction than the inner ridge line 16A).

  As shown in FIG. 2, the displacement suppression unit 30 includes a plurality of rotating rollers 34 as rotating bodies that are electrically rotated (in the present embodiment, a total of three of the displacement suppression units 30 on the right end side in the vehicle width direction). A total of three displacement suppression portions 30 on the left end side in the width direction) are provided. As shown in FIG. 3, a shaft portion 32 is coaxially fixed to the rotating roller 34, and this shaft portion 32 is rotatably supported by a bracket 40 fixed to the rear cross member 22. That is, the rotating roller 34 is supported by the rear cross member 22 via the bracket 40. The bracket 40 has a substantially I-shaped vertical cross-sectional view when viewed from the side of the vehicle. The upper plate portion 40A is fixed to the upper surface of the rear cross member 22 and protrudes toward the rear of the vehicle. Arranged parallel to the plate portion 40A and fixed to the lower surface of the rear cross member 22, the vertical wall portion 40B connects the upper plate portion 40A and the lower plate portion 40C to be fixed to the rear surface (rear surface) of the rear cross member 22. Yes.

  The upper plate portion 40 </ b> A and the lower plate portion 40 </ b> C of the bracket 40 are penetrated by the shaft portion 32 of the rotating roller 34, and a gear 42 is coaxially fixed to the upper end portion of the shaft portion 32. The gear 42 is connected to a motor gear provided on the output shaft of the drive motor 44 through a plurality of gears (not shown) and is rotatable. The drive motor 44 is connected to a control unit (ECU) 46, and the control unit 46 is an element grasped as a sensor 48 (for example, a pre-crash sensor, in a broad sense, “collision prediction means”). )It is connected to the. The sensor 48 is attached to a predetermined position on the vehicle rear end side (for example, the rear bumper cover 24) to predict a rear collision, and the control unit 46 controls the operation of the drive motor 44 based on the prediction result of the sensor 48. Yes (with sensing system). When the collision prediction signal from the sensor 48 is output to the control unit 46, the drive motor 44 is operated by the control unit 46.

  In other words, when the sensor 48 predicts a rear collision, the rotating roller 34 receives a driving force from the driving motor 44 via a plurality of gears 42 (not shown in part), thereby rotating around the axis in the vertical direction of the vehicle body (the shaft portion 32). Around the axis line 32X). As shown in FIG. 4, the rotation direction of the rotation roller 34 is a direction in which the barrier 52 is displaced substantially inward in the vehicle width direction when the barrier 52 as a collision body collides with the rotation roller 34 from the rear side of the vehicle. R direction).

  In the present embodiment, when the barrier 52 collides with the rotating roller 34, the driving motor 44 according to the mass or the like (kinetic energy) of the barrier 52 so that the rotating roller 34 pushed into the barrier 52 does not stop rotating. It is set to change the rotational force. That is, the rotational force of the drive motor 44 is not a constant value in consideration of the inertial force between the vehicle and the barrier 52.

  The rotating roller 34 includes a metal high-rigidity rotating portion 36 that is disposed on the outer peripheral side of the shaft portion 32 and serves as a main body portion of the rotating roller 34. The high-rigidity rotating portion 36 is set such that the rigidity with respect to a load input from an oblique direction (arrow A direction) with respect to the longitudinal direction of the vehicle body is set higher than the rigidity of the rear cross member 22 with respect to the load. It is composed of a high-rigidity and high-strength member that does not deform even if it collides from an oblique direction (arrow A direction) with respect to the direction and is sandwiched between the barrier 52 and the rear cross member 22.

  Further, in order to effectively transmit the rotational force (input load) of the rotating roller 34 to the object (barrier 52) that contacts the rotating roller 34 (that is, the rotating roller 34 does not slide on the contact surface to be contacted). The outer peripheral portion of the high-rigidity rotating part 36 is covered with a rubber covering material 38 (an element grasped as a “non-slip member” in a broad sense) having a higher friction coefficient than that of the high-rigidity rotating part 36. (Glued). In this embodiment, a rubber coating material 38 is wound around and coated (adhered) around the outer periphery of the high-rigidity rotating part 36, but sandpaper is wound around the outer peripheral surface of the high-rigidity rotating part 36. It is good also as (adhered) structure.

  With the above-described configuration, the displacement suppressing unit 30 is configured such that the relative position of the rear cross member 22 with respect to the barrier 52 by rotating the rotating roller 34 when the barrier 52 collides from an oblique direction (arrow A direction) with respect to the longitudinal direction of the vehicle body. (In FIG. 4, the change direction of the relative position of the rear cross member 22 relative to the barrier 52 in the initial stage of the collision is indicated by an arrow C, and the relative position of the barrier 52 relative to the rear cross member 22 in the initial stage of the collision is changed. The direction is indicated by the arrow B direction), and the rear cross member 22 is prevented from being displaced in the vehicle width direction.

  FIG. 5 schematically shows a state in which the displacement of the rear cross member 22 in the vehicle width direction is suppressed by a solid line. In FIG. 5, the thin two-dot chain line schematically shows the position of the rear cross member 22 and the like after the same collision in the contrast structure without the displacement mechanism portion (30), and the thick two-dot chain line shows the rear cross member 22 before the collision. Etc. are schematically shown. As shown in FIG. 5, the shape of the vehicle in plan view (the shape shown by the solid line) formed by the rear cross member 22 and the side rail 16 after the oblique collision (oblique contact) is the same oblique collision in the contrast structure. The vehicle plane formed by the rear cross member 22 and the side rail 16 before the collision is compared with the shape of the vehicle in plan view formed by the rear cross member 22 and the side rail 16 (the shape shown by a thin two-dot chain line). The shape is close to the visual shape (the shape illustrated by the thick two-dot chain line).

(Operation and effect of the embodiment)
Next, the operation and effect of the above embodiment will be described.

  As shown in FIG. 4, according to the vehicle bumper structure 12 according to the present embodiment, the displacement suppressing portion 30 is provided on the rear side of the vehicle body of the rear cross member 22, and the inner ridge line of the side rail 16 in the vehicle plan view. Since the vehicle 52 is disposed at a position in the vehicle width direction on the inner side in the vehicle width direction than 16A, when the barrier 52 collides with the vehicle body rear end side in an oblique direction (arrow A direction) with respect to the vehicle body longitudinal direction (light rear with inclination). At the time of a collision, the barrier 52 collides (contacts) with the displacement suppressing unit 30 before the side rail 16 side. For this reason, the load burden of the side rail 16 is reduced as compared with a comparison structure in which the displacement suppression unit 30 is not provided.

  At this time, a load (oblique pushing force) by the barrier 52 from an oblique direction (arrow A direction) with respect to the longitudinal direction of the vehicle body is transmitted to the rear cross member 22 via the displacement suppressing portion 30 and then the rear cross member 22. Is transmitted to the side rail 16, and a bending moment is applied to the side rail 16 (the end of the side rail 16 on the side of the rear cross member 22 is displaced in the vehicle width direction to move the side rail 16 outward in the vehicle width direction). The moment in the direction of bending) acts and tries to deform the side rail 16 in the vehicle longitudinal direction intermediate portion so as to protrude outward in the vehicle width direction.

  However, in the present embodiment, when the barrier 52 collides from the oblique direction (arrow A direction) with respect to the longitudinal direction of the vehicle body, the displacement suppression unit 30 sets the relative position of the rear cross member 22 to the barrier 52 in the substantially vehicle width direction ( 4), the rear cross member 22 is restrained from being displaced in the vehicle width direction, so that the rear end portion 16C of the side rail 16 on the rear cross member 22 side is displaced in the vehicle width direction. (Side rail mode control, see FIG. 5), a part of the bending moment that should act on the rear cross member 22 acts on the side rail 16 as an axial force in the longitudinal direction of the vehicle (contribution of axial force input). Improvement). Thereby, the load input from the oblique direction (arrow A direction) with respect to the vehicle body longitudinal direction is efficiently transmitted to the vehicle body rear end side in the vehicle longitudinal direction.

  The above phenomenon will be described more precisely. First, when the sensor 48 shown in FIG. 3 predicts a rear collision, a collision prediction signal is output from the sensor 48 to the control unit 46, and the control unit 46 switches the drive motor 44. Is turned on and the drive motor 44 is operated. The driving force of the drive motor 44 is applied to the rotating roller 34 via a plurality of gears 42 (some of which are not shown), whereby the rotating roller 34 is shown around the vertical axis 32X of the vehicle body and in FIG. The barrier 52 rotates in a direction (arrow R direction) that is displaced substantially inward in the vehicle width direction.

  For this reason, when the barrier 52 collides with the rotating roller 34 from an oblique direction (arrow A direction) with respect to the longitudinal direction of the vehicle body, the rear cross member 22 is opposed from the barrier 52 side via the rotating roller 34 in the rotating state. Upon receiving the force, the rotating roller 34 tends to displace in the direction (arrow C direction in FIG. 4) opposite to the direction in which the barrier 52 is displaced (arrow B direction in FIG. 4). That is, the collision load in the oblique direction (arrow A direction) by the barrier 52 tries to displace the rear cross member 22 inwardly in the vehicle width direction, whereas the rear cross member 22 tries to displace in the opposite direction. The displacement amount of the rear cross member 22 in the substantially vehicle width direction is suppressed. In other words, the displacement suppression unit 30 suppresses deformation of the rear cross member 22 and the side rail 16 in the approximate vehicle width direction (deformation in the approximate vehicle width direction inside (arrow B direction) in the range shown in FIG. 4) (FIG. 4). In the range indicated by, it functions to push outward substantially in the vehicle width direction (arrow C direction).

  In addition, the rotating roller 34 includes a high-rigidity rotating portion 36 whose rigidity with respect to a load input from an oblique direction (arrow A direction) with respect to the longitudinal direction of the vehicle body is higher than the rigidity of the rear cross member 22 with respect to the load. When the barrier 52 collides with the rotary roller 34 from an oblique direction (arrow A direction) with respect to the longitudinal direction of the vehicle body, the rear cross member 22 absorbs energy (EA) while being deformed (stroked) toward the front side of the vehicle. In some cases (not shown), the high-rigidity rotating portion 36 rotates without being deformed to suppress the displacement of the rear cross member 22 in the substantially vehicle width direction.

  As described above, according to the vehicle bumper structure 12 according to this embodiment, the load is applied from the oblique direction (arrow A direction) to the vehicle body longitudinal direction on the vehicle body rear end side (vehicle body longitudinal direction end side). Even if is input, the bending moment acting on the side rail 16 can be suppressed.

  To supplement this point, in the case of a light collision with an inclination in which the load input direction is inclined with respect to the longitudinal direction of the vehicle body, in general, compared to the case of a light collision without inclination in which the load input direction is a direction along the longitudinal direction of the vehicle body. Damage to the frame (vehicle frame member) increases. That is, in the case of a light collision with an inclination, since a load is generally input to another vehicle frame member (side rail) before the rear cross member, the region where plastic deformation occurs is larger than that in the case of a light collision without an inclination. . In addition, when the barrier (cart), which is a collision body, collides with the rear cross member in an oblique direction with respect to the longitudinal direction of the vehicle body (in the case of a light collision with inclination), the input direction of the barrier is shifted with respect to the centroid of the side rail. For example, in the contrast structure in which the angle is increased and the displacement suppressing portion 30 is not provided, the displacement in the vehicle width direction of the end portion of the side rail on the side of the rear cross member is not suppressed, so the side rail and the rear cross member are included. A so-called matchbox deformation occurs in the rear frame of the vehicle body (in plan view of the vehicle), and the rear frame of the vehicle body is greatly bent and deformed in the vehicle width direction. When such deformation exceeds the elastic region, the side rail is plastically deformed ( Lateral bending deformation), and the side rail needs to be replaced or repaired. Here, for example, when the side rail has to be greatly deformed and exchanged, the user burden of repair costs also increases.

  On the other hand, according to the present embodiment, compared with the comparison structure, the load input direction to the side rail 16 can be brought closer to the situation (in the case of a light collision without inclination) in the direction along the vehicle longitudinal direction, The bending moment acting on the side rail 16 is suppressed, and so-called matchbox deformation is suppressed. For this reason, plastic deformation of the side rail 16 can be prevented or suppressed (the amount of plastic deformation is reduced), and only the rear cross member 22 is replaced without replacing the side rail 16 depending on the degree of light collision. Since it can respond, a user's expense burden can also be suppressed.

  Further, in the contrast structure that does not suppress the bending moment acting on the side rail, an additional reinforcing member is required as a measure for suppressing the deformation due to the bending moment, but in this embodiment, the moment component of the bending moment is Since the axial force component of the side rail 16 is increased by decreasing the number, the addition of a reinforcing member for suppressing the deformation due to the moment component is basically unnecessary. Further, even if the axial force component of the side rail 16 is increased, the side rail 16 has extremely high rigidity with respect to the axial force component, so that a measure for suppressing deformation due to the axial force component of the side rail 16 is basically unnecessary. is there. That is, the vehicular bumper structure 12 according to the present embodiment has a structure that can sufficiently utilize the proof stress of the side rail 16 that has very high rigidity against the axial force component.

  Further, as another advantage, the rotation roller 34 of the displacement suppressing unit 30 can obtain the above-described operation and effect even if the dimension in the vehicle front-rear direction is not so large. Compared with a comparative structure in which a crash box is disposed in the rear space member, space saving on the rear side of the rear cross member 22 can be achieved. As a result, the degree of freedom of the design at the rear of the vehicle increases, so that it can be said that the design is very useful even when the degree of freedom of the design at the rear of the vehicle is required.

(Supplementary explanation of the embodiment)
In the above-described embodiment, the vehicle bumper structure 12 has the structure of the rear bumper portion 50, and the cross member includes the rear cross member 22 spanned between the rear end portions 16 </ b> C in the longitudinal direction of the pair of side rails 16. However, the vehicle bumper structure may be applied to the front bumper portion, and the cross member may be a front cross member spanned between the front end portions in the longitudinal direction of the pair of side rails.

  Further, in the above-described embodiment, the displacement suppression unit 30 (displacement suppression means) is a direction (arrow R direction) that displaces the barrier 52 substantially inward in the vehicle width direction around the axis line 32X in the vehicle body vertical direction by receiving a driving force. The displacement restraining means applies, for example, a load that causes the collision body to be displaced inward in the vehicle width direction by receiving a driving force, and the collision body from the collision body. Other displacement suppression means such as a bulging mechanism that receives a reaction force in the opposite direction may be used.

  In the above-described embodiment, the case where the rotating body is the rotating roller 34 has been described as an example. However, the rotating body receives, for example, a driving force, and rotates around the axis in the vertical direction of the vehicle body. Other rotating bodies such as a sphere rotating in a direction to be displaced inward in the width direction may be used. Moreover, for example, an endless belt may be wound around a pulley as a pair of rotating bodies.

  Further, in the above embodiment, the rotating roller 34 (rotating body) has a higher rigidity against the load input from the oblique direction (arrow A direction) with respect to the longitudinal direction of the vehicle body than the rigidity of the rear cross member 22 with respect to the load. A rigid rotating part 36 is provided, and such a configuration is preferable. However, the rotating body has, for example, a rigidity with respect to a load input from an oblique direction with respect to the longitudinal direction of the vehicle body equal to the rigidity of the cross member with respect to the load. It may be another rotating body such as

  Furthermore, in the above embodiment, the sensor 48 shown in FIG. 3 predicts a rear collision, and the control unit 46 controls the operation of the drive motor 44 based on the prediction result of the sensor 48. Sensor (which is an element grasped as “collision detection means” in a broad sense), and the control unit may control the operation of the drive motor based on the detection result of the sensor.

  In the above embodiment, a part of the displacement suppressing portion 30 is exposed to the vehicle body rear side from the cutout portion 24A of the rear bumper cover 24. For example, the displacement suppressing means is located on the inner side in the vehicle front-rear direction of the bumper cover (the rear bumper cover). The bumper cover partly displaces when the colliding body collides obliquely with respect to the longitudinal direction of the vehicle body, even though it is disposed and exposed on the front side of the vehicle and the rear side of the front bumper cover. If the displacement restraining means is configured to restrain the displacement of the cross member in the vehicle width direction by changing the relative position of the cross member with respect to the collision body in the substantially vehicle width direction, the above described Functions and effects similar to those of the embodiment can be obtained.

  In the above embodiment, the bracket 40 is provided to support the rotating roller 34, and the rotating roller 34 is stably attached to a predetermined position of the rear cross member 22 via the bracket 40. The rotating body is mounted so as to be movable relative to the cross member in the vehicle width direction. At the time of an oblique collision, the rotating body is sandwiched between the collision body and the cross member from the beginning of the collision, and a rotational force is applied to both. You may make it the structure which makes it.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing a vehicle body rear structure including a vehicle bumper structure according to an embodiment of the present invention in a plan view. 1 is a perspective view showing a vehicle bumper structure according to an embodiment of the present invention. FIG. 3 is an enlarged sectional view taken along line 3-3 in FIG. 2. It is a horizontal sectional view showing the important section of the bumper structure for vehicles concerning one embodiment of the present invention. It is explanatory drawing which shows typically the state of the vehicle body rear part after a collision by planar view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Car body 12 Bumper structure for vehicles 16 Side rail 16A Inner ridgeline 16C Rear end part (end part of a longitudinal direction)
22 Rear cross member (cross member)
30 Displacement suppression part (displacement suppression means)
34 Rotating roller (Rotating body)
36 High rigidity rotating part 52 Barrier (impact)
A diagonal direction

Claims (3)

A pair of left and right side rails arranged on both sides in the vehicle width direction of the vehicle body in the longitudinal direction of the vehicle body are spanned between the ends in the longitudinal direction, and the vehicle width direction is elongated on the vehicle body longitudinal direction end side. A cross member arranged as a direction,
The cross member is provided on the outer side of the vehicle body in the front-rear direction, and is disposed at a position in the vehicle width direction on the inner side of the inner side ridge line of the side rail in the vehicle plan view. A displacement suppressing means for suppressing the displacement of the cross member in the vehicle width direction by changing the relative position of the cross member in the vehicle width direction in the case of
Bumper structure for vehicles characterized by having.   2. The displacement suppressing means includes a rotating body that rotates around an axis in a vertical direction of a vehicle body and in a direction that displaces the collision body substantially inward in the vehicle width direction by receiving a driving force. The vehicle bumper structure described.   The said rotary body is provided with the highly rigid rotation part whose rigidity with respect to the load input from the diagonal direction with respect to the vehicle body front-back direction is higher than the rigidity of the said cross member with respect to the said load. Bumper structure for vehicles.

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