JP2010089627A - Impact reducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact reducing device for suppressing stress concentration on a collision object and diving of the collision object into a vehicle lower part with simple constitution and reduced weight and cost. <P>SOLUTION: A bumper 3 is made to have a two-step structure of a front side part 5 and a rear side part 7. The rear side part 7 makes each of a groove part 9 and a groove wall 13 of the groove part 9 as a part of a wall surface, and includes a pair of cylinder bodies connected by a rear end connecting part 27 of the groove wall 13. Each of the cylinder bodies is constituted of a groove wall 13, an upper wall 21a or a lower wall 21b opposed to the groove wall 13, and front wall 17 and rear wall 19 having unevenness 45. The front side part 5 includes two sheets of wall parts 11 continuously provided on upper side and lower side of the groove part 9. When the collision object 29 collides against the bumper 3, the two sheets of wall parts 11 open upward and downward, and the front side part 5 deforms, while receiving the collision object 29 by comparatively low load, Subsequently, the groove wall 13 of the groove part 9 of the rear side part 7 opens with the rear end connecting part 27 as a center, and the rear side part 7 deforms, while firmly receiving the collision object 29 by a wide surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an impact mitigation device.

  Conventionally, as a shock absorber (bumper) attached to a vehicle, (1) the bumper has a multi-part configuration, and the bumper opens in the event of a collision, so that the contact area becomes large, so that the bending deformation of the collision object compared to a normal bumper (For example, refer to Patent Document 1). Moreover, (2) what prevents the collision object from entering the lower part of the cover at the time of a collision and prevents the dynamic bending angle of the collision object from increasing (for example, see Patent Document 2), and (3) the front The strength balance is set so that the bumper becomes weak against the load from above the vehicle, and when the collision object collides from the front of the vehicle, the bumper deforms in accordance with the bending degree of the collision object (for example, see Patent Document 3) )was there.

UK Patent GB 2 336 812A JP 2001-146140 A JP 2006-264495 A

  However, the bumper of (1) has a possibility that a large impact load may be generated even if the contact area is large because the rigidity of the bumper itself is not low. In addition, stress concentration may occur at the upper end. The bumper (2) can be expected to prevent the collision object from entering below the cover, but the area of the bumper itself has hardly changed. The bumper (3) deforms flexibly according to the degree of bending of the collision object, but has a large number of parts and a complicated structure.

  The present invention has been made in view of such problems. The object of the present invention is a simple structure, light weight, and low cost, and stress concentration on the collision object and subsidence of the collision object to the lower part of the vehicle. An object of the present invention is to provide an impact mitigation device that can be suppressed.

  The present invention for achieving the above-mentioned object is an impact mitigation device incorporated in a vehicle, and is provided in front of the vehicle, and is provided in front of the rear side portion for mitigating the impact, A front side portion that relaxes, and the rear side portion includes a groove portion in a substantially horizontal direction that opens forward, a groove wall on the upper side and a groove wall on the lower side of the groove portion, respectively, as part of the wall surface, A pair of cylindrical bodies coupled at a rear end of the groove wall, and the front side portion includes two wall portions provided continuously above and below the groove portion, respectively. When the collision object collides with the front side part, the groove part opens, and after the deformation of the front side part proceeds while suppressing the initial generated load, the pair of cylindrical bodies are crushed to disperse the load and the rear side part Is an impact mitigating device characterized by deforming.

  The cylinder includes, for example, a groove wall, a wall facing the groove wall, a front wall disposed behind the wall portion, and a rear wall disposed behind the front wall. And the rear wall which comprises a pair of cylinders is couple | bonded in the rear end of a groove wall. At this time, the rigidity of the front wall and the rear wall is higher than the rigidity of the groove wall and the wall facing the groove wall. In order to increase the rigidity, for example, unevenness is provided on the front wall and the rear wall.

  The upper end portion of the upper wall portion and the lower end portion of the lower wall portion may be coupled to the cylinder. Further, the rear portion of the upper groove wall and the rear portion of the lower groove wall may be integrated. In the front surface of the front side part or / and the space between the front side part and the rear side part, a cushioning material is provided as necessary.

  In the present invention, the apparatus has a two-stage structure including a front side portion that is an open cross-sectional portion and a rear side portion that is a closed cross-sectional portion. When a collision object collides with the apparatus, the front side portion is deformed while suppressing an initial generated load with a relatively low constant load, and then the rear side portion is deformed while dispersing the load and absorbing the remaining energy. When the rear side part is deformed, the groove part opens up and down, and the receiving surface of the collision object widens, so that the collision object is firmly received in a wide range. As a result, stress concentration on the collision object can be suppressed, and the collision object can be prevented from entering the lower part of the vehicle.

  According to the present invention, it is possible to provide an impact mitigation device that is simple in structure, lightweight, and inexpensive, and that can suppress stress concentration on a collision object and the collision object from entering the lower part of the vehicle.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of the front portion of the vehicle 1, and FIG. 2 is a vertical sectional view of the bumper 3. 2 is a cross-sectional view taken along arrow AA shown in FIG.

  As shown in FIG. 1, the vehicle 1 has a bumper 3 that is an impact mitigation device. As shown in FIG. 2, the bumper 3 has a two-stage structure including a front side portion 5 and a rear side portion 7 in a vertical section.

  The rear side portion 7 has a substantially horizontal groove portion 9 opening forward, a groove wall 13a on the upper side of the groove portion 9 and a groove wall 13b on the lower side as part of the wall surface, and a rear end coupling portion of the groove wall 13 27 and a pair of cylinders joined together. Of the pair of cylinders, the upper cylinder includes a groove wall 13a, an upper wall 21a facing the groove wall 13a, a front wall 17a, and a rear wall 19a disposed behind the front wall 17a. The lower cylinder includes a groove wall 13b, a lower wall 21b facing the groove wall 13b, a front wall 17b, and a rear wall 19b disposed behind the front wall 17b.

  The front wall 17 (front wall 17a, front wall 17b) and the rear wall 19 (rear wall 19a, rear wall 19b) are provided with irregularities 45. By providing the unevenness 45, the front wall 17 and the rear wall 19 have higher rigidity than the groove wall 13, the upper wall 21a, and the lower wall 21b. In addition, the shape of the unevenness | corrugation 45 does not need to be what is shown in FIG.

  The front side part 5 has two wall parts 11a and 11b provided continuously above and below the groove part 9, respectively. The upper wall portion 11 a is provided continuously to the upper groove wall 13 a of the groove portion 9 and is disposed in front of the front wall 17 a of the rear side portion 7. The lower wall portion 11 b is provided continuously to the lower groove wall 13 b of the groove portion 9 and is disposed in front of the front wall 17 b of the rear side portion 7. A space 25 having a predetermined size is provided between the wall portion 11 and the front wall 17.

  In the bumper 3 shown in FIG. 2, a member composed of the wall portion 11 and the groove wall 13 and a member composed of the front wall 17, the upper wall 21 a, the lower wall 21 b, and the rear wall 19 are separate from each other. Formed and then integrated. As a material constituting the bumper 3, for example, aluminum may be used.

  Moreover, when manufacturing a bumper, the member comprised by the wall part 11 and the groove wall 13, and the member comprised by the front wall 17, the upper wall 21a, the lower wall 21b, and the rear wall 19 are extruded aluminum. In some cases, it may be manufactured as one piece. Further, a member constituted by the wall portion 11 and the groove wall 13 and a member constituted by the front wall 17, the upper wall 21a, the lower wall 21b, and the rear wall 19 are manufactured separately using different materials. After that, it may be integrated.

  Next, an analysis result of the operation of the bumper 3 when a collision object collides will be described. FIG. 3 is a view showing an analysis model, FIG. 4 is a view showing an analysis result of a bumper central section, and FIG. 5 is a view showing an analysis result of a restraint reaction force time history.

  FIG. 4A is a diagram showing a state immediately after the collision of the collision object 29. As shown in FIG. 3, when a long columnar collision object 29 collides in the horizontal direction near the center of the front surface 23 of the wall 11 of the bumper 3, as shown by an arrow A in FIG. The wall portion 11a opens upward, the wall portion 11b opens downward, and the front side portion 5 that is an open cross-sectional portion is deformed. As shown in a region 33 in FIG. 5, the bumper 3 absorbs energy by softly receiving the collision object 29 with a relatively low constant load until the front side portion 5 is completely crushed.

  4B is a diagram illustrating a state in which the rear side portion 7 is being deformed, and FIG. 4C is a diagram illustrating a state in which the bumper 3 is at the maximum deformed state. After the front side portion 5 is crushed, the groove wall 13a and the groove wall 13b of the groove portion 9 of the rear side portion 7 open around the rear end coupling portion 27, as shown by an arrow B in FIG. The space 43 is deformed into a substantially parallelogram and reaches the state shown in FIG.

  As shown in a region 35 in FIG. 5, when the rear side portion 7 is deformed, the load increases more than when the front side portion 5 is deformed. However, the groove 9 is opened and the receiving surface of the collision object 29 is widened. Thus, the collision object 29 can be received firmly and the remaining energy can be absorbed. Since the rear side part 7 which is a closed cross-section part is hard to cause a cross-sectional collapse, it can bear a relatively large load. When the rear side portion 7 is deformed, the groove portion 9 is opened and the receiving surface is widened, so that there is an effect that the portion where the force is applied is dispersed and bending deformation due to a single point concentrated load is suppressed.

  4 and 5 assume a collision of a relatively heavy collision object or a collision at a high speed. However, in a low-speed collision with a light and soft collision object, all energy is absorbed when the front side portion 5 is completely crushed. The rear side portion 7 is not deformed.

  Thus, in this Embodiment, the bumper 3 is made into the two-stage structure of the front side part 5 which is an open cross section, and the rear side part 7 which is a closed cross section. The front side portion 5 is less rigid (strength against deformation due to a collision from the front) than the rear side portion 7. Therefore, at the initial stage of the collision, the front side part 5 receives the collision object with a substantially constant load and deforms while absorbing energy, and then the rear side part 7 firmly receives the collision object and deforms while absorbing the remaining large energy. To do. In the bumper 3, the rear side portion 7 is opened and the receiving surface of the collision object is widened, so that it is possible to suppress stress concentration on the collision object and to prevent the collision object from entering the lower portion of the vehicle 1.

  The bumper 3 is inexpensive because it has a simple structure, and is lightweight because it is made of an aluminum material. Further, a cushioning material such as urethane, which is normally disposed on the front surface 23 of the bumper 3, can be omitted.

  In the present embodiment, the unevenness 45 is provided to increase the rigidity of the front wall 17 and the rear wall 19 of the rear side portion 7, but the method of increasing the rigidity is not limited to this. FIG. 6 shows a vertical sectional view of another bumper 3a. As shown in FIG. 6, the plate thicknesses of the front wall 17c and the front wall 17d, the rear wall 19c and the rear wall 19d may be thicker than those of the groove wall 13a and the groove wall 13b, the upper wall 21a and the lower wall 21b. Good.

  Moreover, in this Embodiment, although the front side part 5 was made into the open cross-section part, the space between the front side part 5 and the rear side part 7 is good also as a closed space. FIG. 7 shows a vertical sectional view of another bumper 3b. As shown in FIG. 7, in the bumper 3 b, the upper end portion 15 a of the wall portion 11 a above the front side portion 5 is coupled to the corner portion 37 of the cylindrical body above the rear side portion 7. Further, the lower end portion 15 b of the wall portion 11 b below the front side portion 5 is coupled to the corner portion 37 of the cylindrical body below the rear side portion 7.

  In the bumper 3b, the space 25a and the space 25b between the front side portion 5 and the rear side portion 7 are closed spaces. However, the upper end portion 15a of the wall portion 11a and the corner portion 37 of the cylindrical body, and the lower end portion 15b of the wall portion 11b and the corner portion 37 of the cylindrical body are coupled with a weaker material than the other portions. Sometimes, after these joints are removed, deformation similar to that of the bumper 3 occurs.

  Furthermore, in the bumper 3 of the present embodiment, the bottom of the groove 9 is located at the rear end coupling portion 27, but the bottom of the groove 9 may be located in the middle of the rear side portion 7. FIG. 8 shows a vertical sectional view of another bumper 3c. As shown in FIG. 8, in the bumper 3c, the rear portion 39 of the upper groove wall 13a and the rear portion 39 of the lower groove wall 13b are integrated, and a partition wall is formed between the pair of cylinders of the rear side portion 7. 41 is formed.

  In the bumper 3 of the present embodiment, no cushioning material is installed, but a cushioning material such as urethane is disposed in the front surface 23 of the front side portion 5 and / or the space 25 between the front side portion 5 and the rear side portion 7. May be.

  The shape of the wall part 11 of the front side part 5 is not restricted to what is shown in FIG. In FIG. 2, the vertical section of the front surface 23 of the wall portion 11 is substantially linear, but may have other shapes such as an arc shape. Further, the angle formed by the groove wall 13 and the wall portion 11 of the groove portion 9 is appropriately set according to the thickness, material, etc. of the constituent material of the bumper.

  In the impact mitigation device of the present invention, by changing the material, plate thickness, shape, and the like of the front side portion 5 and the rear side portion 7, the magnitude of the reaction force in the region 33 and the region 35 in FIG.

  The preferred embodiments of the impact mitigation device according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

A perspective view of a front portion of the vehicle 1 Bumper 3 vertical section Diagram showing analysis model Figure showing the analysis result of the cross-sectional shape of the bumper center The figure which shows the analysis result of the time history of restraint reaction force Vertical sectional view of another bumper 3a Vertical sectional view of another bumper 3b Vertical sectional view of another bumper 3c

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ......... Vehicle 3 ......... Bumper 5 ......... Front side part 7 ......... Rear side part 9 ......... Groove part 11 ......... Wall part 13, 13a, 13b ......... Groove wall 15a ......... Upper end part 15b ......... Lower end portion 17 ......... Front wall 19 ......... Rear wall 21a ......... Upper wall 21b ......... Lower wall 23 ......... Front side 25 ......... Space 27 ......... Rear end coupling portion 29 ... ... Collision 39 ... ... Back part

Claims (7)

An impact mitigation device incorporated in a vehicle,
A rear side part that is provided in front of the vehicle and relieves impact;
A front side portion provided in front of the rear side portion to alleviate impact;
Comprising
The rear side portion includes a substantially horizontal groove portion opening forward, a groove wall on the upper side and a groove wall on the lower side of the groove portion, and a pair coupled at the rear end of the groove wall. And has a cylindrical body,
The front side portion has two wall portions provided continuously above and below the groove portion, respectively.
When a collision object collides with the front side part, the groove part opens, and after the deformation of the front side part proceeds while suppressing the initial generated load, the pair of cylindrical bodies are crushed and the rear side part is deformed while dispersing the load. An impact mitigation device characterized by: The cylindrical body includes the groove wall, a wall facing the groove wall, a front wall disposed behind the wall portion, and a rear wall disposed behind the front wall,
The impact mitigation device according to claim 1, wherein the rear walls constituting the pair of cylinders are coupled to each other at a rear end of the groove wall.   The impact mitigation device according to claim 2, wherein the rigidity of the front wall and the rear wall is higher than the rigidity of the groove wall and a wall facing the groove wall.   The impact mitigation device according to claim 3, wherein the front wall and the rear wall are provided with unevenness.   The impact mitigation device according to any one of claims 1 to 4, wherein an upper end portion of the upper wall portion and a lower end portion of the lower wall portion are coupled to the cylindrical body.   The impact mitigation device according to any one of claims 1 to 5, wherein a rear portion of the upper groove wall and a rear portion of the lower groove wall are integrated.   The shock absorbing device according to any one of claims 1 to 6, wherein a cushioning material is provided in a front surface of the front side portion and / or a space between the front side portion and the rear side portion. .

Images