JP2007098971A - Impact absorbing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact absorbing device capable of absorbing impact even when the impact from the diagonal direction is applied. <P>SOLUTION: This impact absorbing device is furnished with an impact absorbing member 4 interposed between a bumper reinforcement 8 and a side member 1 of a vehicle and to absorb the impact to the bumper reinforcement 8 by plastic deformation and provided with a correction member 26 to generate a correction moment in a direction to cancel a moment against the moment based on working force of a component in the cross direction of the vehicle applied on the impact absorbing member 4 by the impact. The correction member 26 has rigidity and is arranged to the outside of the vehicle from a center in the axial direction of the impact absorbing member 4, and the correction moment is generated by making the working force of the component in the longitudinal direction of the vehicle work more largely on the outside of the vehicle of the impact absorbing member 4 than on the inside of the vehicle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an impact absorbing device that is interposed between a bumper reinforcement and a vehicle body of a vehicle and absorbs an impact on the bumper reinforcement by plastic deformation.

  2. Description of the Related Art Conventionally, an impact absorbing device that absorbs an impact applied to a bumper reinforcement of a vehicle by plastic deformation is known. For example, as disclosed in Patent Document 1, this shock absorbing device is provided with a shock absorbing member having a multistage structure in which a small diameter pipe is connected to a large diameter pipe between a bumper reinforcement and a side member of a vehicle body, When an impact was applied to the bumper reinforcement, the small diameter tube of the shock absorbing member was plastically deformed so as to be folded inside the large diameter tube, and the impact was absorbed by this plastic deformation.

Further, as disclosed in Patent Document 2, this shock absorbing device is provided with a hollow shock absorbing member between the bumper reinforcement and the side member of the vehicle body, and the shock absorbing member is formed in a bellows shape at the center. When an impact is applied to the bumper reinforcement, the bellows-like impact absorbing member is crushed so as to be folded in the axial direction to absorb the impact.
JP 2001-47952 A JP 2002-104107 A

  However, in such a conventional device, when an impact in the front-rear direction is applied to the front of the vehicle, the impact absorbing member can be plastically deformed in the vehicle front-rear direction to absorb the impact, but when an impact is applied from an oblique direction of the vehicle, There is a case where the shock cannot be absorbed.

  For example, as shown in FIG. 8, when a vehicle collides with each other and a vehicle width of about 40% wraps and the collision angle is about 10 degrees, an impact from an oblique direction of about 10 degrees with respect to the vehicle front-rear direction. The acting force F is applied. This acting force F acts on the tip side of the impact absorbing member 100, and the acting force F can be decomposed into an acting force Fx of the vehicle longitudinal component and an acting force Fy of the vehicle lateral component. The moment M1 acts on the impact absorbing member 100 by the acting force Fy of the vehicle lateral component.

  Since the impact absorbing member 100 is formed in a hollow shape, when an impact is applied from the oblique direction of the vehicle, the magnitude of the inner component force Fin applied to the vehicle inner side of the impact absorbing member 100 and the outer component force Fout applied to the outer side of the vehicle. The inner component force Fin applied to the inside of the vehicle becomes larger. The moment M2 acts on the impact absorbing member 100 also by the difference in magnitude between the two component forces Fout and Fin.

  The moment M1 due to the acting force Fy in the lateral component of the vehicle and the moment M2 due to the difference in magnitude between the component forces Fout and Fin act in the same direction, and the shock absorbing member 100 is plastically deformed by both moments M1 and M2. Instead, as shown by a broken line in FIG. 8, there is a problem that the impact absorbing member 100 may fall down and the impact may not be absorbed.

  An object of the present invention is to provide an impact absorbing device that can absorb an impact satisfactorily even when an impact from an oblique direction is applied.

In order to achieve this problem, the present invention has taken the following measures in order to solve the problem. That is,
In an impact absorbing device including an impact absorbing member that is interposed between a bumper reinforcement and a side member of a vehicle and absorbs an impact on the bumper reinforcement by plastic deformation,
An impact absorbing device comprising a correcting member that generates a correcting moment in a direction to cancel the moment with respect to a moment based on an acting force of a vehicle lateral component applied to the impact absorbing member by the impact. That is it.

  The correction member may be configured to generate the correction moment by causing the acting force of the vehicle longitudinal component due to the impact to act on the vehicle outer side of the shock absorbing member more than the vehicle inner side. At this time, the correction member has rigidity and is arranged on the vehicle outer side rather than the axial center of the shock absorbing member, and transmits the acting force of the vehicle longitudinal component due to the shock to the vehicle outer side of the shock absorbing member. It is good also as composition to do. Alternatively, the correction member has a flexible portion that can be deformed by the impact, and the flexible portion is disposed closer to the inside of the vehicle than the center of the shock absorbing member in the axial direction. It is good also as a structure which acts more largely the action force of the vehicle front-back direction component by the said impact than the vehicle inner side.

  In the impact absorbing device of the present invention, even when an impact from an oblique direction is applied, the correcting member generates a correcting moment in the direction in which the correcting member cancels the moment based on the acting force of the vehicle lateral component, so that the impact absorbing member falls down. The effect of being able to absorb the impact well is suppressed.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
As shown in FIG. 1 and FIG. 2, reference numerals 1 and 2 denote side members of the vehicle. The side members 1 and 2 are formed of hollow cylindrical bodies, and the cylindrical ends of the side members 1 and 2 are the front side of the vehicle. The cylindrical end is protruded to the left and right sides, and is opened toward the front side of the vehicle.

  A bumper reinforcement 8 is attached to each end of the side members 1 and 2 via impact absorbing members 4 and 6. In the present embodiment, since the shape is bilaterally symmetric, the side member 1 and the shock absorbing member 4 on the left side of the vehicle will be described in detail below.

  An end plate 10 is attached to the front end of the side member 1 on the vehicle front side so as to close the cylindrical end of the side member 1 by welding or the like. A communication hole 12 is formed in the end plate 10, and the communication hole 12 is communicated with the cylindrical interior of the side member 1.

  A mounting plate 14 is attached to the end plate 10 with a bolt or the like (not shown). A through hole 16 is formed in the mounting plate 14, and the through hole 16 is formed coaxially with the communication hole 12. The through hole 16 is formed in communication with the cylindrical interior of the side member 1 through the communication hole 12. The communication hole 12 has the same diameter as the through hole 16 or a larger diameter. The cylindrical interior of the side member 1 is formed to be the same as or larger than the diameter of the through hole 16. The periphery of the through hole 16 of the mounting plate 14 is formed flat.

  The mounting plate 14 may be directly attached to the side member 1 without providing the end plate 10. Further, the through-hole 16 does not necessarily need to communicate with the inside of the cylindrical side member 1, and the back side only needs to be a space.

  The bumper reinforcement 8 is disposed to face the mounting plate 14. A connection plate 18 is attached to the bumper reinforcement 8, and an impact absorbing member 4 is attached via the connection plate 18, and the impact absorbing member 4 is formed of a circular pipe in this embodiment. ing.

  The shock absorbing member 4 includes a cylindrical portion 20 whose tip is fixed to the connecting plate 18 by welding or the like. The cylindrical portion 20 protrudes from the bumper reinforcement 8 toward the side member 1, and the shock absorbing member 4. A flange portion 22 is integrally formed on the side member 1 side. The shock absorbing member 4 only needs to be formed in a hollow shape, and the cross-sectional shape thereof is not limited to a circle but may be an ellipse, a hexagon, or the like.

  The flange portion 22 is integrally formed by bending outward in the radial direction of the shock absorbing member 4. The flange portion 22 is bent in the radial direction via the arc portion 24. The through hole 16 and the shock absorbing member 4 are arranged so as to be coaxially positioned, and the outer periphery of the flange portion 22 is attached to the attachment plate 14 of the side member 1 by welding. The outer diameter of the flange portion 22 is determined such that the outer diameter of the flange portion 22 is welded to the mounting plate 14 outside the through hole 16 of the mounting plate 14.

  As shown in FIG. 2, when the thickness of the shock absorbing member 4 is t, the inner diameter D2 of the through hole 16 is larger than the value obtained by adding twice the thickness t to the outer diameter D1 of the cylindrical portion 20. (D2> D1 + 2t).

  As shown in FIG. 3, the bumper reinforcement 8 has a substantially B-shaped cross section orthogonal to its longitudinal direction, and is formed by press-molding a plate material, and is opened substantially in the center of the cross section at the rear of the vehicle. A rectangular groove 8 a is formed, and substantially rectangular hollow portions 8 b and 8 c whose periphery is closed on both sides of the groove 8 a are formed along the longitudinal direction of the bumper reinforcement 8.

  The connecting plate 18 is attached to the vehicle rear outer side of the bumper reinforcement 8 so as to straddle both the hollow portions 8b, 8c of the bumper reinforcement 8 from the outer side. It is bent along the outside of the Pari reinforcement 8 and has a substantially U-shaped cross section.

  The connecting plate 18 blocks the opening 8 of the groove 8a of the bumper reinforcement 8 and inserts the correction member 26 into the closed groove 8a. The correction member 26 has rigidity and is formed of a square pipe in the present embodiment, but is not limited thereto, and may be formed in a box shape by press working or the like.

  The correction member 26 is inserted into the groove 8a, and is disposed on the outer side of the vehicle from the axial center C of the shock absorbing member 4. Further, the correction member 26 is disposed on the vehicle front extension of the outer wall of the shock absorbing member 4. The correction member 26 has rigidity and reinforces the bumper reinforcement 8 from the outside of the vehicle with respect to the axial center C of the shock absorbing member 4.

Next, the operation of the impact absorbing device of the present embodiment described above will be described.
As shown in FIG. 4, when an impact is applied to the bumper reinforcement 8, for example, when a collision occurs between vehicles, about 40% of the width of the vehicle wraps and the collision angle is about 10 degrees. Acts on the shock absorbing member 4 at an angle of about 10 degrees.

  The impact force F is decomposed into an acting force Fx as a vehicle longitudinal component and an acting force Fy as a vehicle lateral component. Since the acting force Fy of the lateral component acts in a direction perpendicular to the axial direction of the shock absorbing member 4, a moment M1 based on the acting force Fy of the lateral component acts on the shock absorbing member 4. This moment M1 works to tilt the shock absorbing member 4 toward the inside of the vehicle.

  Further, the bumper reinforcement 8 is deformed flat at the collision point of the bumper reinforcement 8 due to the impact applied to the bumper reinforcement 8, but the correction member is inserted at the point where the correction member 26 is inserted. The degree of deformation is small due to the rigidity of 26. Therefore, when the impact force acts on the impact absorbing member 4, the impact force acts more on the outside of the impact absorbing member 4 on the side where the correction member 26 is inserted.

  That is, the acting force Fx of the front-rear direction component acting in the axial direction of the shock absorbing member 4 is different between the vehicle outer side and the vehicle inner side of the shock absorbing member 4, and the outer component force acting on the vehicle outer wall of the shock absorbing member 4. Fout becomes larger than the inner component force Fin acting on the vehicle inner wall of the shock absorbing member 4. Accordingly, a correction moment M2 that attempts to tilt the shock absorbing member 4 to the outside of the vehicle acts due to the difference in magnitude between the outer component force Fout and the inner component force Fin.

  Both the moment M1 and the correction moment M2 act on the shock absorbing member 4, but their directions are opposite and work so as to cancel each other. Accordingly, the shock absorbing member 4 is prevented from falling, and the flange portion 22 side of the shock absorbing member 4 is caused to penetrate the through hole 16 of the mounting plate 14 by the acting force Fx of the vehicle longitudinal component acting in the axial direction of the shock absorbing member 4. And bends into the through-hole 16. In particular, the arc portion 24 is bent into the through hole 16, and the arc portion 24 is bent with a small inner radius and is folded back from the through hole 16 toward the bumper reinforcement 8 side.

  The arc portion 24 is bent into the through hole 16, and the shock absorbing member 4 is folded inside the side member 1. By being folded back with a small radius, plastic deformation is quickly started in response to an impact applied to the bumper reinforcement 8.

  As the shock absorbing member 4 enters the through-hole 16, new plastic deformation is performed, and the arc portion 24 is folded inside the side member 1 so that the shock absorbing member 4 is folded back. The impact energy is consumed for plastic deformation of the impact absorbing member 4, and the impact is absorbed.

  In the present embodiment, the shock absorbing member 4 is an example of a case where the shock absorbing member 4 is folded into a U shape when plastically deformed. However, the present invention is not limited to this, and the shock absorbing member 4 is folded in a bellows shape in the axial direction. A structure that is crushed in the axial direction by an impact can also be implemented. Further, the correction member 26 is formed separately from the bumper reinforcement 8 and then inserted into the groove 8a and fixed. However, the correction member 26 is not limited to this, and the correction member 26 is integrated with the bumper reinforcement 8. Formation, for example, a configuration in which ribs or the like as correction members are attached so that the rigidity of a part of the bumper reinforcement 8 corresponding to the place where the correction member 26 is provided can be implemented.

  Next, an impact absorbing device of a second embodiment different from the above-described embodiment will be described with reference to FIGS. The same members as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The impact absorbing device of the second embodiment is different from the above-described embodiment in the bumper reinforcement 8 and the correction member 26. In the impact absorbing device of the second embodiment, the bumper reinforcement 31 has a hat cross-sectional shape, is formed by press-molding a plate material, and opens to the rear of the vehicle along the longitudinal direction of the bumper reinforcement 31. A groove 32 is formed. The edge of the bumper reinforcement 31 in the vehicle vertical direction is bent in the vertical direction.

  The correction member 34 is inserted into the groove 32, and the tip of the shock absorbing member 4 is fixed to the correction member 34 by welding or the like. One end of the correction member 34 is fixed to the bottom of the groove 32 of the bumper reinforcement 31 by welding or the like, and an inclined portion 34a that is inclined rearward toward the vehicle inner side is formed.

  The tip of the shock absorbing member 4 is fixed to the inclined portion 34a by welding or the like, and the tip of the shock absorbing member 4 is formed obliquely so that the vehicle outer side protrudes more forward than the vehicle inner side. In the second embodiment, the front bumper is used as an example. However, when the rear bumper is used, the front end of the shock absorbing member 4 is positioned more rearward of the vehicle than the inner side of the vehicle. What is necessary is just to protrude and form diagonally.

  A flexible portion 34b that is inclined from the inclined portion 34a toward the bottom of the groove 32 is formed, the tip extends from the tip of the flexible portion 34b along the bottom of the groove 32, and is welded to the bottom of the groove 32 by welding or the like. It is fixed.

  As shown in FIG. 6, the inclined portion 34 a has the edge of the inclined portion 34 a in the vertical direction of the vehicle bent to the outside of the shock absorbing member 4. Further, the flexible portion 34b is disposed on the vehicle inner side than the center C in the axial direction of the impact absorbing member 4, and the flexible portion 34b is deformed by an impact before the impact absorbing member 4 is plastically deformed when an impact is applied. It is formed to be flexible.

Next, the operation of the impact absorbing device of the second embodiment described above will be described.
Similarly to the case described above, when an impact is applied to the bumper reinforcement 31, for example, when a vehicle collides with each other and a vehicle width of about 40% wraps and the collision angle is about 10 degrees, the impact force F is It acts on the shock absorbing member 4 at an angle of about 10 degrees.

  The impact force F is decomposed into an acting force Fx as a vehicle longitudinal component and an acting force Fy as a vehicle lateral component. Since the acting force Fy of the vehicle lateral component acts in a direction perpendicular to the axial direction of the shock absorbing member 4, a moment M1 based on the acting force Fy of the vehicle transverse component acts on the shock absorbing member 4. This moment M1 works to tilt the shock absorbing member 4 toward the inside of the vehicle.

  Further, when an impact force is applied to the correction member 34 through the bumper reinforcement 31 due to an impact applied to the bumper reinforcement 31, the flexible portion 34b is plastically deformed as shown in FIG. 34 collapses. The correction member 34 is crushed, the vehicle outer side of the inclined portion 34a contacts the bottom of the groove 32 of the bumper reinforcement 31 without any gap, and the impact applied to the bumper reinforcement 31 is absorbed by the shock through the inclined portion 34a. It comes to be added to the member 4. At that time, the front end of the shock absorbing member 4 on the outside of the vehicle abuts against the bumper reinforcement 31 via the inclined portion 34a, and the impact force acts on the outside of the shock absorbing member 4 more than the inside of the vehicle.

  That is, the acting force Fx of the vehicle longitudinal component acting in the axial direction of the shock absorbing member 4 is different between the vehicle outer side and the vehicle inner side of the shock absorbing member 4 and the outer component acting on the vehicle outer wall of the shock absorbing member 4. The force Fout is larger than the inner component force Fin acting on the vehicle inner wall of the shock absorbing member 4. Accordingly, a correction moment M2 that attempts to tilt the shock absorbing member 4 to the outside of the vehicle acts due to the difference in magnitude between the outer component force Fout and the inner component force Fin.

  Both the moment M1 and the correction moment M2 act on the shock absorbing member 4, but their directions are opposite and work so as to cancel each other. Accordingly, the shock absorbing member 4 is prevented from falling, and the flange portion 22 side of the shock absorbing member 4 is caused to penetrate the through hole 16 of the mounting plate 14 by the acting force Fx of the vehicle longitudinal component acting in the axial direction of the shock absorbing member 4. And bends into the through-hole 16. In particular, the arc portion 24 is bent into the through hole 16, and the arc portion 24 is bent with a small inner radius and is folded back from the through hole 16 toward the bumper reinforcement 8 side.

  The arc portion 24 is bent into the through hole 16, and the shock absorbing member 4 is folded inside the side member 1. By being folded back with a small radius, plastic deformation is quickly started with respect to the load applied to the bumper reinforcement 31.

  As the shock absorbing member 4 enters the through-hole 16, new plastic deformation is performed, and the arc portion 24 is folded inside the side member 1 so that the shock absorbing member 4 is folded back. The impact energy is consumed for plastic deformation of the impact absorbing member 4, and the impact is absorbed.

  In the second embodiment, the shock absorbing member 4 is folded into a U shape when plastically deformed. However, the present invention is not limited to this, and the shock absorbing member 4 is bent in a bellows shape in the axial direction. Thus, a structure that is crushed in the axial direction by an impact can also be implemented. Moreover, although the correction member 34 was formed separately from the bumper reinforcement 31, the present invention is not limited to this, and when the bumper reinforcement 8 of the above-described embodiment is used, the correction member 34 is replaced with the bumper reinforcement. For example, by forming a flexible part in a part of the bumper reinforcement 8 facing the vehicle inner side of the shock absorbing member 4 and deforming the flexible part of the bumper reinforcement 8. It is also possible to configure the correction moment M2 to work.

  The present invention is not limited to such embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention.

It is a top view which shows the structure which interposed the impact-absorbing device of this embodiment between the bumper reinforcement and the side member. It is a principal part expanded sectional view of the impact-absorbing device of this embodiment. It is AA sectional drawing of FIG. It is explanatory drawing at the time of the shock absorption by the shock absorber of this embodiment. It is a principal part expanded sectional view of the impact-absorbing device of 2nd Embodiment. It is BB sectional drawing of FIG. It is explanatory drawing at the time of the shock absorption by the shock absorber of 2nd Embodiment. It is explanatory drawing in the case of the impact absorption by the conventional impact-absorbing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 ... Side member 4, 6, 100 ... Shock absorption member 8, 31 ... Bumper reinforcement 8a, 32 ... Groove 8b, 8c ... Hollow part 10 ... End plate 12 ... Communication hole 14 ... Mounting plate 16 ... Through Hole 18 ... Connecting plate 20 ... Tube part 22 ... Flange part 24 ... Arc part 26, 34 ... Correction member 34a ... Inclined part 34b ... Flexible part

Claims (4)

In an impact absorbing device including an impact absorbing member that is interposed between a bumper reinforcement and a side member of a vehicle and absorbs an impact on the bumper reinforcement by plastic deformation,
An impact absorbing device comprising a correcting member that generates a correcting moment in a direction to cancel the moment with respect to a moment based on an acting force of a vehicle lateral component applied to the impact absorbing member by the impact. . 2. The correction member causes the correction moment to be generated by applying an action force of a vehicle front-rear direction component caused by the impact more to the outside of the shock absorbing member than to the inside of the vehicle. Shock absorber. The correction member has rigidity and is disposed on the vehicle outer side than the axial center of the shock absorbing member, and transmits the acting force of the vehicle longitudinal component due to the shock to the vehicle outer side of the shock absorbing member. The impact absorbing device according to claim 2, wherein the device is an impact absorbing device. The correction member has a flexible portion that can be deformed by the impact, and the flexible portion is disposed on the inner side of the vehicle with respect to the axial center of the shock absorbing member. 3. The impact absorbing device according to claim 2, wherein an acting force of the vehicle longitudinal direction component due to the impact is exerted more than the inside.

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