JP2008189233A - Vehicle front part structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain the tip of a frame from being deformed upward in a projecting shape in a head-on collision, in a structure offsetting the lower end of a crash box under the frame. <P>SOLUTION: The crash box 16 is connected to the front of a front side frame 12 by sandwiching a plate member 14 composed of a front side plate 30, an intermediate plate 32 and a rear side plate 34. A lower ridgeline 16A of the crash box 16 is positioned under a lower ridgeline 12A of the front side frame 12. Flanges 36 forming vertical walls are formed on both sides and in a lower part of an opening 35 on the vehicle rear side of the rear side plate 34. The rear side plate 34 has a slit 37 along the flange 36, and is welded to the intermediate plate 32 in the vicinity of the slit 37. The front end of the front side frame 12 is also inserted so as to abut on the flange 36. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle front structure, and in particular, a vehicle including a frame disposed in a vehicle front-rear direction and a crash box having a lower ridge line disposed below a lower ridge line of the frame on the vehicle front side of the frame. It relates to the front structure.

In Patent Document 1 below, in order to improve shock absorption performance when an RV vehicle with a high frame height collides with a vehicle with a low frame height, the front end of the premeter frame of the RV vehicle is There is disclosed a structure in which a guide unit including a guide member protruding toward the side is disposed.
JP 2004-189136 A

  However, in the case of the above prior art, since a large guide unit is attached, the structure becomes complicated and the cost increases.

  On the other hand, a structure is used in which the crash box at the front end of the vehicle is enlarged below the vehicle rather than the frame. However, with this structure, at the position where the lower end of the crash box and the frame are offset, non-uniform input enters the upper and lower ridge lines of the frame, and the front end of the frame tends to be deformed upward.

  An object of the present invention is to obtain a vehicle front structure capable of suppressing the convex deformation of the front end portion of the frame in consideration of the above fact.

  In the vehicle front structure according to the first aspect of the present invention, a frame disposed in the front-rear direction of the vehicle at the front portion of the vehicle, and a lower ridge line disposed below the lower ridge line of the frame on the vehicle front side of the frame. A vehicle front portion structure including a crash box, and a front plate connected to the crash box between the crash box and the frame, and a vehicle rear side than the front plate And at least one intermediate plate, and a rear plate connected to a vehicle rear side of the intermediate plate and provided with a flange as a standing wall around the front end portion of the frame.

  According to a second aspect of the present invention, in the vehicle front structure according to the first aspect, the rear plate includes a slit along the flange, and an edge of the slit is welded to the intermediate plate. And

  According to a third aspect of the present invention, in the vehicle front portion structure according to the first aspect, the flange is formed by being bent into a substantially U shape so that two standing walls are formed on the rear side of the vehicle. An end portion bent in a letter shape is welded to the intermediate plate.

  According to a fourth aspect of the present invention, in the vehicle front portion structure according to any one of the first to third aspects, the thickness of the intermediate plate is thicker than the thickness of the front plate. To do.

  According to the first aspect of the present invention, the front plate connected to the crash box between the frame in the vehicle front-rear direction and the crash box on the vehicle front side of the frame, and the vehicle rear side of the front plate. At least one intermediate plate to be arranged and a rear plate connected to the vehicle rear side of the intermediate plate are arranged, and a flange serving as a standing wall is formed around the front end portion of the frame on the rear plate. Has been. And the rigidity of the flange periphery of the front-end part of a flame | frame increases by the flange of the back side plate connected with the intermediate | middle plate being arrange | positioned around the front-end part of a flame | frame.

  Therefore, even if the bottom ridge line of the crash box is positioned (offset) below the bottom ridge line of the frame, if it is input to the bottom ridge line of the crash box at the time of frontal collision, the front plate, the intermediate plate, and the rear plate The reaction force can be taken by and the crash box is deformed along the vehicle longitudinal direction. At that time, the deformation load of the crash box can be generated according to the performance, and the energy absorption performance is equivalent to the case where the crash box and the frame are not offset. Further, bending of the front plate, the intermediate plate, and the rear plate can be suppressed.

  As a result, the crash box and the frame can be axially compressed and deformed as intended along the vehicle front-rear direction during a frontal collision. Further, since the collision load can be uniformly input to the frame, it is possible to suppress the front end portion of the frame from being deformed upward in a convex shape. For this reason, it can suppress that the suspension tower of the front-wheel tire provided in the vehicle rear inner side upper part of a flame | frame retreats by the deformation | transformation of the front-end | tip part of a flame | frame.

  According to the second aspect of the present invention, the slit is provided along the flange of the rear side plate, and the edge of the slit is welded to the intermediate plate. By welding the rear side plate and the intermediate plate, it is possible to suppress the central portion of the rear side plate from being lifted from the intermediate plate at the time of a frontal collision. Further, by providing the slit, the rear plate can be welded to the intermediate plate after the intermediate plate is connected to the frame by arc welding or the like. For this reason, you may weld a back side plate and an intermediate | middle plate before and after connecting a flame | frame, and the freedom degree of an assembly | attachment improves. Moreover, the weight of the rear side plate can be reduced by providing the slit.

  According to the third aspect of the present invention, the flange of the rear side plate is formed in a substantially U shape so that there are two standing walls on the rear side of the vehicle. A preferable cross-sectional rigidity can be set. In addition, since the end portion of the flange that is bent into a substantially U shape is welded to the intermediate plate, the central portion of the rear side plate is prevented from floating from the intermediate plate at the time of a frontal collision.

  According to the fourth aspect of the present invention, since the plate thickness of the intermediate plate is set to be thicker than the plate thickness of the front plate, the rigidity of the intermediate plate is increased, and the front plate, the intermediate plate, and the rear plate are increased during a frontal collision. The bending of the side plate is further suppressed.

  As described above, in the vehicle front structure according to the first aspect of the present invention, bending of the front plate, the intermediate plate, and the rear plate is suppressed at the time of a frontal collision, and the front end portion of the frame is convex upward. Deformation is suppressed. For this reason, it is possible to suppress the backward movement of the suspension tower of the front wheel tire provided at the upper part of the frame inside the rear of the vehicle.

  The vehicle front portion structure according to the second aspect of the present invention can suppress the central portion of the rear side plate from floating from the intermediate plate at the time of a frontal collision. Moreover, after connecting an intermediate plate to a flame | frame, a back side plate can be welded to an intermediate plate, and the freedom degree of an assembly | attachment improves. Further, the weight of the rear side plate can be reduced.

  In the vehicle front structure according to the third aspect of the present invention, the rear side plate can be set to a preferable cross-sectional rigidity. Moreover, it can suppress that the center part of a back side plate floats up from an intermediate | middle plate at the time of front collision.

  The vehicle front portion structure according to the fourth aspect of the present invention can further suppress the bending of the front side plate, the intermediate plate, and the rear side plate during a frontal collision.

[First Embodiment]
Hereinafter, a first embodiment of a vehicle front structure according to the present invention will be described with reference to FIGS. In these drawings, an arrow FR appropriately shown indicates the vehicle front side, an arrow UP indicates the vehicle upper side, and an arrow OUT indicates the vehicle width direction outer side.

  FIG. 1 shows an overall configuration of a vehicle front structure according to the present embodiment. As shown in this figure, front side frames 12 extending in the vehicle front-rear direction are disposed on both sides of a front portion 10A of a vehicle 10 of an automobile. In front of the front side frame 12, a crash box 16 is connected with a plate member 14 including a front plate 30, an intermediate plate 32, and a rear plate 34, which will be described later, interposed therebetween. A front cross member 18 extending in the vehicle width direction is connected to the lower portion of the front side frame 12. A front bumper reinforcement 20 having a cross-section “eye” shape extending in the vehicle width direction is connected to the front of the crash box 16 via a plate 19. A pulling hook 22 is connected to the front lower portion of the front cross member 18.

  2 and 6 show the main part of the vehicle front structure according to the present embodiment. As shown in FIGS. 2, 3, and 6, the front side frame 12 has a closed cross-sectional structure with a substantially rectangular cross section, and the crash box 16 has a closed cross-sectional structure with a substantially 8-shaped cross section. As shown in FIG. 1, the lower ridge line 16 </ b> A of the crash box 16 is formed to be positioned below the lower ridge line 12 </ b> A of the front side frame 12, and the upper ridge line 16 </ b> B of the crash box 16 is It is formed at substantially the same height as the upper ridgeline 12B.

  As shown in FIGS. 2, 3, and 6, the plate member 14 includes three plates, a front plate 30, an intermediate plate 32, and a rear plate 34 that are sequentially arranged from the vehicle front side. The front side plate 30 and the intermediate plate 32 are made of rectangular members having substantially the same shape, and an upper portion on the inner side in the vehicle width direction is notched and a central portion projects inward. Further, the plate thickness of the intermediate plate 32 is set to be thicker than the plate thickness of the front side plate 30. For example, the plate thickness of the front plate 30 is set to about 3 mm, and the plate thickness of the intermediate plate 32 is set to 1.9 times the plate thickness of the front plate 30. The intermediate plate 32 is formed with a large-diameter circular opening 33A at the center and two small-diameter circular openings 33B above and below the opening 33A in order to reduce weight.

  The rear side plate 34 is formed shorter on the upper side than the front side plate 30 and the intermediate plate 32, and a rectangular opening 35 into which the front end portion of the front side frame 12 is inserted is provided at the center. At the periphery of the opening 35 in the rear side plate 34, flanges 36 are formed on both sides and the lower part of the opening 35 in the vehicle width direction and serve as standing walls erected toward the vehicle rear side. As shown in FIG. 4, the front end portion of the front side frame 12 is inserted so as to contact the both sides of the opening 35 in the vehicle width direction and the lower flange 36.

  Three slits 37 are formed in the rear plate 34 along both the vehicle width direction side and the lower flange 36. The rear side plate 34 is joined to the intermediate plate 32 by arc welding 38 at a position on the flange 36 side near the three slits 37. The plate | board thickness of the back side plate 34 is set to about 3 mm, for example. Moreover, as a material of the front side plate 30, the intermediate | middle plate 32, and the back side plate 34, a steel plate etc. are used, for example.

  As shown in FIG. 3, a plurality of bolt insertion holes 40, 41, 42 are formed at the edges of the front side plate 30, the intermediate plate 32, and the rear side plate 34 on both sides in the vehicle width direction. ing. When the rear side plate 34 and the intermediate plate 32 are joined by the arc welding 38, the bolt insertion holes 41 and 42 are joined at the same position. Further, the bolts 44 are inserted into the bolt insertion holes 40, 41, 42 via the washers 45 on both sides in the vehicle front-rear direction, and the nuts 46 are fastened so that the front plate 30, the intermediate plate 32, and the rear plate 34 are connected. They are connected in a three-layered state.

  As shown in FIGS. 2 and 5, the front plate 30 is joined to the rear end portion of the crash box 16 by arc welding. The intermediate plate 32 is joined to the front end portion of the front side frame 12 by arc welding.

  Next, the operation and effect of this embodiment will be described.

  As shown in FIG. 7, when the front portion 10 </ b> A of the vehicle 10 collides with the barrier 60, the crash box 16 disposed on the rear side of the front bumper reinforcement 20 is deformed, and the front plate 30 and the intermediate plate are deformed. A compressive force is applied to the front side frame 12 via a plate member 14 including 32 and a rear side plate 34. At that time, the plate thickness of the intermediate plate 32 is made thicker than the plate thickness of the front side plate 30, and flanges 36 are provided on both sides of the front end portion of the front side frame 12 of the rear side plate 34 in the vehicle width direction and below. Therefore, the rigidity around the flange 36 at the front end of the front side frame 12 is increased.

  Accordingly, even when the lower ridge line 16A of the crash box 16 is disposed (offset) below the lower ridge line 12A of the front side frame 12, if the crash box 16 is input to the lower ridge line 16A of the crash box 16 at the time of a frontal collision, the front side The reaction force can be obtained by the plate 30, the intermediate plate 32, and the rear side plate 34, and the crash box 16 is deformed along the vehicle longitudinal direction. At that time, the deformation load of the crash box 16 can be generated according to the performance, and the energy absorption performance is equivalent to the case where the crash box 16 and the front side frame 12 are not offset. For this reason, as shown in FIG. 8, the crash box 16 undergoes axial compression deformation along the vehicle longitudinal direction so that small wrinkles are generated. Further, since the edge of the slit 37 of the rear side plate 34 is welded to the intermediate plate 32, it is possible to suppress the central portion of the rear side plate 34 from floating up from the intermediate plate 32 at the time of a frontal collision. The bending of the plate 32 and the rear side plate 34 can be suppressed.

  As a result, the crash box 16 and the front side frame 12 can be axially compressed and deformed as intended along the vehicle front-rear direction during a frontal collision. Further, as shown in FIG. 7, since the collision load can be uniformly input to the front side frame 12, the front end portion 12C (see FIG. 7) of the front side frame 12 may be deformed upwardly in a convex shape. It is suppressed. For this reason, it is possible to prevent the suspension tower 52 of the front wheel tire (not shown) provided at the upper rear side of the front side frame 12 from retreating due to the deformation of the front end portion 12C of the front side frame 12. Thereby, it can suppress that the suspension tower 52 interferes with the dash panel 50 arrange | positioned at the vehicle rear side.

  Further, by providing the slit 37, the rear side plate 34 can be welded to the intermediate plate 32 after the intermediate plate 32 is arc welded to the front side frame 12. For this reason, the rear side plate 34 and the intermediate plate 32 may be welded either before or after the front side frame 12 is connected, and the degree of freedom of assembly is improved. Further, by providing the slit 37, the weight of the rear side plate 34 can be reduced.

  FIG. 9 shows a vehicle front structure of a comparative example. In the configuration of the comparative example, a plate member 102 including two front plates 104 and a rear plate 106 is disposed between the front side frame 12 and the crash box 16. The plate thicknesses of the front side plate 104 and the rear side plate 106 are both set to about 3 mm. In this configuration, when the front portion 100A of the vehicle collides with the barrier 60, as shown in FIG. 10, the crash box 16 is deformed, and the front plate 104 and the front side plate 104 on the vehicle front side of the lower ridge line 12A of the front side frame 12. The rear side plate 106 is deformed.

  That is, when the lower ridge line 16A of the crash box 16 is disposed (offset) below the lower ridge line 12A of the front side frame 12, if the crash box 16 is input during a frontal collision, A uniform reaction force cannot be taken up and down by the rear side plate 106, and the deformation of the crash box 16 becomes non-uniform. Further, as shown in FIG. 9, the collision load cannot be uniformly input to the front side frame 12, and the front end portion 12C of the front side frame 12 is deformed in a convex shape (arrow A in FIG. 9). reference). For this reason, the retraction amount of the suspension tower 52 provided in the upper part inside the vehicle rear side of the front side frame 12 increases.

[Second Embodiment]
Next, 2nd Embodiment of the vehicle front part structure which concerns on this invention is described using FIGS. 11-13. In addition, about the same component as 1st Embodiment mentioned above, the same number is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 11 and 12, the crash box 16 is connected to the front side frame 12 with a plate member 70 including a front plate 30, an intermediate plate 32, and a rear plate 72 interposed therebetween. The rear side plate 72 is formed so that the upper side is shorter than the front side plate 30 and the intermediate plate 32, and a rectangular opening 73 into which the front end portion of the front side frame 12 is inserted is provided at the center. On both sides of the opening 73 in the rear side plate 72 in the vehicle width direction, flanges 74 that protrude toward the rear side of the vehicle are provided. The flange 74 is formed by being bent into a substantially U shape so that there are two standing walls 74A extending on the vehicle rear side. A bead 76 is provided below the opening 73 of the rear side plate 72 and protrudes toward the vehicle rear side along the lower edge of the opening 73. The front end portion of the front side frame 12 is inserted so as to abut against the standing walls 74A of the flanges 74 on both sides in the vehicle width direction of the opening 73 of the rear side plate 72.

  As shown in FIG. 13, in the rear side plate 72, an end portion of the flange 74 bent in a substantially U shape and a lower edge portion of the opening 73 are joined to the intermediate plate 32 by arc welding 78. The plate | board thickness of the back side plate 72 is set to about 3 mm, for example.

  In such a vehicle front portion structure, flanges 74 having two standing walls 74A are provided on both sides of the front end portion of the front side frame 12 of the rear side plate 72, and a bead 76 is provided below the opening 73. Therefore, the rigidity around the flange 74 of the rear side plate 72 at the front end portion of the front side frame 12 is increased. Further, the section modulus of the flange 74 is increased, and a preferable section rigidity can be set.

  Accordingly, even when the lower ridge line 16A of the crash box 16 is disposed (offset) below the lower ridge line 12A of the front side frame 12, if the crash box 16 is input to the lower ridge line 16A of the crash box 16 at the time of a frontal collision, the front side The reaction force can be obtained by the plate 30, the intermediate plate 32, and the rear side plate 72, and the crash box 16 is deformed along the vehicle longitudinal direction. At that time, the deformation load of the crash box 16 can be generated according to the performance, and the energy absorption performance is equivalent to the case where the crash box 16 and the front side frame 12 are not offset. Further, since the intermediate plate 32 and the rear side plate 72 are welded, the lifting of the rear side plate 72 can be suppressed, and the bending of the front side plate 30, the intermediate plate 32, and the rear side plate 72 can be suppressed.

  As a result, the crash box 16 and the front side frame 12 can be axially compressed and deformed as intended along the vehicle front-rear direction during a frontal collision. Further, since the collision load can be uniformly input to the front side frame 12, it is possible to suppress the front end portion of the front side frame 12 from being deformed upward in a convex shape.

  FIG. 14 shows a graph of the relationship between the load and time input to the lower ridge line 16A of the crash box 16 in the vehicle front structure of the first embodiment and the second embodiment and the vehicle front structure of the comparative example. ing. The target value in FIG. 14 is set to a value at which the plate member disposed between the crash box 16 and the front side frame 12 is not bent. As shown in this graph, it is confirmed that the load input to the lower ridge line 16A of the crash box 16 approaches the target value in the vehicle front structure of the first embodiment as compared with the vehicle front structure of the comparative example. it can. Moreover, in the vehicle front part structure of 2nd Embodiment, it can confirm that the load input into the lower ridgeline 16A of the crash box 16 exceeds target value.

[Supplementary explanation of the embodiment]
(1) In the first embodiment and the second embodiment described above, the front end portion of the front side frame 12 is joined to the intermediate plate 32 by arc welding. May be coupled to the rear plates 34, 72.

  (2) In the first embodiment and the second embodiment described above, the plate members 14 and 70 disposed between the front side frame 12 and the crash box 16 are three plates of a front side plate, an intermediate plate, and a rear side plate. However, the present invention is not limited to this, and the intermediate plate may be composed of two or more plates.

  (3) In the first embodiment and the second embodiment described above, the plate thickness of the intermediate plate 32 is made larger than the plate thickness of the front side frame 12, but both plate thicknesses may be set to be the same. In this case, in the present invention, only the front plate and the intermediate plate are disposed between the crash box 16 and the front side frame 12, and the front plate and the intermediate plate have the same thickness. The rigidity around the flange at the front end of the front side frame 12 can be increased only by adding the rear plates 34 and 72, and the increase in cost can be suppressed.

1 is a schematic side view showing a front portion of a vehicle to which a vehicle front structure according to a first embodiment is applied. It is a perspective view showing the whole vehicle front part structure concerning a 1st embodiment. FIG. 3 is an exploded perspective view showing an overall configuration of the vehicle front portion structure shown in FIG. 2. FIG. 3 is a plan view showing a vehicle rear side of the vehicle front portion structure shown in FIG. 2. FIG. 3 is a cross-sectional plan view showing a vehicle front side of the vehicle front structure shown in FIG. 2. FIG. 3 is a perspective view of the entire configuration of the vehicle front structure shown in FIG. 2 as viewed from the vehicle front side. FIG. 3 is a side view showing a state of a front portion of a vehicle at the time of a frontal collision of the vehicle to which the vehicle front portion structure shown in FIG. 2 is applied. It is a partial side view which shows the deformation | transformation state of the vehicle front part structure at the time of front collision. It is a side view which shows the state of the vehicle front part at the time of the front collision of the vehicle of the vehicle front part structure of a comparative example. It is a partial side view which shows the deformation | transformation state at the time of front collision of the vehicle front part structure of a comparative example. It is a perspective view which shows the whole structure of the vehicle front part structure which concerns on 2nd Embodiment. It is a disassembled perspective view which shows the whole structure of the vehicle front part structure shown in FIG. FIG. 3 is a plan view showing a vehicle rear side of the vehicle front portion structure shown in FIG. 2. It is a graph which shows the relationship between the load input into the crash box in the vehicle front part structure of 1st Embodiment, 2nd Embodiment, and a comparative example, and time.

Explanation of symbols

10 vehicle 10A front part 12 front side frame (frame)
12A Lower ridge line 16 Crash box 16A Lower ridge line 30 Front side plate 32 Intermediate plate 34 Rear side plate 36 Flange 37 Slit 38 Arc welding (welding)
72 Rear plate 74 Flange 74A Standing wall 78 Arc welding (welding)

Claims (4)

A vehicle front structure comprising: a frame disposed in a vehicle front-rear direction at a front portion of a vehicle; and a crash box having a lower ridge line disposed below a lower ridge line of the frame on a vehicle front side of the frame. There,
Between the crash box and the frame,
A front plate connected to the crash box;
At least one intermediate plate disposed on the vehicle rear side of the front side plate;
A rear side plate connected to the vehicle rear side of the intermediate plate, and provided with a flange serving as a standing wall around the front end of the frame;
A vehicle front structure characterized by comprising:   The vehicle front structure according to claim 1, wherein the rear plate includes a slit along the flange, and an edge portion of the slit is welded to the intermediate plate.   The flange is formed to be bent in a substantially U shape so that there are two standing walls on the vehicle rear side, and an end portion bent in the substantially U shape is welded to the intermediate plate. The vehicle front part structure according to claim 1.   The vehicle front structure according to any one of claims 1 to 3, wherein a thickness of the intermediate plate is larger than a thickness of the front side plate.

Images