JP2015071327A - Vehicle body structure of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle body structure of a vehicle capable of absorbing collision energy efficiently by making a vehicle body side member and a suspension member collapse deform properly.SOLUTION: A rear side member 11 is controlled to a deformation mode in which the rear side member is folded into an approximately Z-shape in side view with a first folding promotion part 14 where is deformed by mountain-folding and a second folding promotion part 15 where is deformed by valley-folding as origins with respect to rear surface collision input F actuating to its axial direction, and a rear suspension member 21 is held in an approximately horizontal arrangement state and is displaced upward, and the rear suspension member and the rear side member 11 are subjected to collapse deformation properly, for absorbing collision energy.

Description

  The present invention relates to an automobile body structure.

  Patent Document 1 discloses a vehicle body structure in which a pair of rear center frames that similarly extend in the vehicle front-rear direction are disposed between a pair of left and right rear side members that extend in the vehicle front-rear direction at the rear portion of the vehicle body. .

JP 2009-67376 A

  The disclosed technique of Patent Document 1 attempts to absorb the collision energy and increase the amount of absorption by collapsing and deforming both the rear side member and the rear center frame at the time of rear collision of the vehicle. As a rear center frame is added, it is undeniable that it is disadvantageous in terms of weight and cost.

  Accordingly, the present invention provides a vehicle body structure for an automobile in which a vehicle body side member and a suspension member are used as energy absorbing members, and collision energy can be efficiently absorbed by appropriately crushing and deforming them.

  The vehicle body structure according to the present invention includes a pair of left and right vehicle body side members extending in the vehicle front-rear direction on both sides in the vehicle width direction at the front or rear of the vehicle body, and a vehicle body end below the vehicle body side member. Suspension members connected and arranged substantially parallel to the vehicle body side members by front and rear fastening portions on the side of the vehicle body and the center of the vehicle body.

  The vehicle body side member is set at a portion corresponding to the front and rear fastening portions, and a first bending promoting portion that promotes a mountain-fold deformation with respect to an axial input at the time of a vehicle collision, And a second bending promoting portion that is set at a portion closer to the center of the vehicle body than the fastening portion and promotes valley bending deformation with respect to the axial input.

  Then, the vehicle body which becomes the axial direction input end of the vehicle body side member, with the cross-sectional center position of the portion where the first bending promoting portion is set and the cross-sectional center position of the portion where the second bending promoting portion is set The main feature is that it is set to be offset upward and downward with respect to the center position of the cross section of the end on the end side.

  According to the present invention, when a vehicle collision occurs, the vehicle body side member has a side surface starting from the first and second bending promoting portions with respect to a collision input that acts on the end portion of the vehicle body side member on the vehicle body end side. It is controlled to a deformation mode that is bent into a substantially Z shape when viewed.

  As a result, the upward rotation of the suspension member around the second bending promoting portion is restricted, and the suspension member is displaced upward while maintaining the arrangement state substantially parallel to the vehicle body side member.

  As a result, the collision input can be input to the suspension member as an axial crushing load, the suspension member can be appropriately crushed and deformed together with the vehicle body side member, and the collision energy can be efficiently absorbed.

The perspective explanatory view seen from the lower side of the embodiment which applied the present invention to the body rear part. Side surface explanatory drawing of embodiment shown in FIG. FIG. 2 is a perspective explanatory view showing the rear side member in the embodiment shown in FIG. 1 in an exploded manner. FIG. 4 is a perspective explanatory view showing an assembled state of the rear side member shown in FIG. 3. Sectional drawing which follows the AA line of FIG. Sectional drawing which follows the BB line of FIG. FIG. 2 is an explanatory plan view showing (A) and (B) before and after deformation of the rear suspension member in the embodiment shown in FIG. 1. Side surface explanatory drawing shown to (A) and (B) before and after a deformation | transformation of embodiment shown in FIG. The characteristic view which shows the relationship between the vehicle deceleration at the time of the vehicle body deformation | transformation shown in FIG. 8, and time.

  Hereinafter, a case where an embodiment of the present invention is applied to a rear portion of a vehicle body will be described in detail with reference to the drawings.

  The vehicle body structure of the embodiment shown in FIG. 1 is one in which the present invention is applied to the rear part of the vehicle body, and shows the arrangement state of the rear side member 11 as the vehicle body side member and the rear suspension member 21 as the suspension member as seen from the lower surface side. ing.

  The rear side member 11 constitutes a longitudinal frame member at the rear of the vehicle body, and is joined to both side edges of the rear floor panel 1 in the vehicle width direction so as to extend in the vehicle longitudinal direction. A rear suspension member 21 that supports a rear wheel (not shown) is connected and disposed across the left and right rear side members 11 and 11.

  As will be described later, the rear suspension member 21 includes front and rear fastening portions 22 and 23 on the vehicle body center side and the vehicle body end side, and these fastening portions 22 and 23 are provided on the lower surfaces of the front and rear side portions of the rear side member 11. The seats 12 and 13 are fastened and fixed, and are connected and arranged substantially parallel to the rear side member 11.

  As shown in FIG. 2, the rear side member 11 includes a first bending promoting portion 14 that promotes mountain-fold deformation (upward bending deformation) with respect to the axial input F at the time of a rear-end collision of the vehicle, and the axial input F On the other hand, a second bending promoting portion 15 that promotes valley bending deformation (downward bending deformation) is provided.

  The first bending promoting portion 14 is set at a portion corresponding to the front and rear fastening portions 22 and 23 of the rear suspension member 21, and the second bending promoting portion 15 is a fastening portion on the front side (vehicle body center side). It is set adjacent to the vehicle 22 and at the center of the vehicle body.

Then, the cross-sectional center position O ₁ of the portion sets a first bending promotion portion 14, and a cross-sectional center position O ₂ of the portion sets the second bending promotion portion 15, the axial input end of the rear side member 11 Are set to be offset upward and downward with respect to the cross-sectional center position O of the rear end.

  Specifically, the above-described rear side member 11 includes a member base portion 11A connected to the side sill 2 that is one of the floor skeleton members of the front floor, a kickup portion 11B that rises inclined from the member base portion 11A, and the kickup portion. Member general portion 11C extending substantially horizontally from 11B.

  The seat portions 12 and 13 are formed on the lower surface of the lower side of the kick-up portion 11B and the lower surface of the rear side of the member general portion 11C, and the rear suspension member 21 has front and rear fastening portions 22 and 23. By fastening and fixing to these seats 12 and 13, as described above, the lower side lower surface of the kick-up portion 11B and the rear lower surface of the member general portion 11C are connected and arranged substantially horizontally.

  And while setting the 1st bending acceleration | stimulation part 14 to the vehicle front-back direction intermediate position of the member general part 11C corresponding to the intermediate part of the front and rear fastening parts 22 and 23, the 2nd bending acceleration | stimulation part 15 is set. It is set at a connecting position between the member general portion 11A and the kick-up portion 11B that is closer to the vehicle body center side than the fastening portion 22 on the front side (vehicle body center side).

  The 1st bending promotion part 14 and the 2nd bending promotion part 15 can be easily comprised by making it a weak structure locally, respectively. For example, in the first bending promotion portion 14, a crushing bead is provided in the lower ridge line of the member general portion 11C as shown in FIGS. 1 and 2 to form a fragile structure, and the second bending promotion is performed. The portion 15 can be easily configured by forming a fragile structure by recessing a fold line or a crushing bead in the vehicle width direction at the upper surface side connecting portion between the member base portion 11A and the kick-up portion 11B.

  In FIG. 1, reference numeral 3 denotes a pin stay of a reinforcing member that connects the front fastening portion 22 of the rear suspension member 21 and the rear end portion of the side sill 2 on the front floor side.

  In the present embodiment, as shown in FIGS. 3 to 6, the rear side member 11 is a groove-shaped lower member 16 made of a metal plate, and an L-shaped upper member 17 that is welded and joined by closing its upper open portion. It has a closed cross section.

  In the example shown in FIGS. 3 and 4, the lower member 16 and the upper member 17 are configured such that the outer side in the vehicle width direction of the member base portion 11A is open, and the member base portion 11A is formed at the rear end of the sill inner 2a of the side sill 2. It is fitted and fixed by spot welding or the like.

  Then, a crushing reaction force is applied to the inner surface of the lower wall that becomes the compression side due to the mountain-fold deformation in the first bending promotion portion 14 and the inner surface of the upper wall that becomes the compression side due to the valley-fold deformation in the second bending promotion portion 15. The supplementary reinforcements 18 and 19 are jointly arranged by spot welding or the like.

  The strength of the second bending promoting portion 15 in the rear side member 11 is set to be larger than the sum of the strength of the rear suspension member 21 and the strength of the region where the rear suspension member 21 is disposed in the rear side member 11.

  FIG. 7 shows an embodiment of the above-described rear suspension member 21, and a pair of left and right side members 24 extending in the vehicle front-rear direction, and a pair of front and rear cross members 25, 26 connecting these side members 24, 24. And having a substantially rectangular frame shape.

The cross members 25, 26 are each provided with arm portions 25A, 26A extending from the connecting portion with the side member 24 to the outside in the vehicle width direction. , 23 are provided.

  As the fastening portions 22 and 23, a general-purpose bush type mount member provided with an insulator for vibration isolation can be used.

  The front cross member 25 is formed in a substantially straight shape including the arm portion 25A, while the rear cross member 26 is formed in an arc shape that is convex toward the front of the vehicle in plan view. The portion 26A extends obliquely rearward toward the vehicle body end side on the rear side of the vehicle.

  Thereby, a crushing stroke region S1 having a required dimension at the time of a rear collision of the vehicle is set in the arm portion 26A.

  The arm portion 26A is set to have a lower strength than the other parts of the rear suspension member 21, and the rear suspension member 21 has a front side of the crushing stroke region S1 in the rear suspension member 21 in the event of a rear surface collision of the vehicle. A shape-retaining region S2 that is difficult to be crushed is secured.

  Further, the connecting point of the arm portion 26A to the rear side member 21 by the fastening portion 23 is required from the rear end of the rear side member 11, for example, the rear end of the crash box 4 connected to the rear bumper (not shown). The offset amount L is set to a position offset toward the front of the vehicle (vehicle center side).

  According to the present embodiment configured as described above, when a collision input F of a predetermined value or more acts on the rear end portion of the rear side member 11 in the axial direction at the time of a rear surface collision of the vehicle, the rear side member 11 is crushed and deformed forward of the vehicle.

At this time, the rear side member 11 has the cross-sectional center positions O ₁ and O ₂ in the first bending promoting portion 14 and the second bending promoting portion 15 with respect to the collision input F acting in the axial direction at the rear end. By the offset arrangement, the deformation mode is controlled so as to bend in a substantially Z-shape when viewed from the side with these folding promotion portions 14 and 15 as starting points.

  That is, as shown in FIG. 2, a moment M1 in the clockwise direction on the paper acts on the first folding promoting portion 14 to promote mountain fold deformation, and a moment M2 on the counterclockwise direction on the paper acts on the second folding promoting portion 15. Encourage valley deformation.

  As a result, the overall upward rotation of the rear suspension member 21 around the second bending promoting portion 15 is restricted, and the rear suspension is changed from the state shown in FIG. 8A to the state shown in FIG. 8B. The member 21 is displaced upward, that is, lifted up while maintaining the arrangement state substantially parallel to the rear side member 11.

  As a result, the collision input F can be input to the rear suspension member 21 as an axial crushing load so that the rear suspension member 21 can be appropriately crushed and deformed together with the rear side member 11 to efficiently absorb the collision energy. .

  Further, as described above, the rear side member 11 is bent and deformed in a substantially Z shape when viewed from the side, and the rear suspension member 21 is lifted up and moved in a substantially horizontal state. It is also possible to avoid interference with important safety parts 10 such as a fuel tank or a battery in an electric vehicle arranged below the floor.

  In particular, in the present embodiment, the above-described rear side member 11 includes a member base portion 11A that is connected to the side sill 2 on the front floor side, a kickup portion 11B that is inclined and rises therefrom, and a member that is provided in a row and extends substantially horizontally. It is formed as a general part 11C.

  Therefore, when the rear side member 11 is shaped, the first and second bending promoting portions 14 and 15 are set, and the coupling positions of the fastening portions 22 and 23 of the rear suspension member 21 are set. The rear side member 11 with the kick-up portion 11B as a support can be bent and deformed in a substantially Z-shaped side surface and the rear suspension member 21 can be lifted up while maintaining a substantially horizontal structure.

  As a result, the buckling deformation mode in the vehicle front-rear direction at the rear of the vehicle body is stabilized, and the crushing deformation toward the front of the vehicle is performed in an orderly manner, and a good energy absorption effect can be obtained.

  In the present embodiment, the rear side member 11 is formed in a closed cross section in which the lower member 16 and the upper member 17 made of a metal plate are joined, and the inner surface of the lower wall that becomes the compression side due to the mountain bending deformation in the first bending promoting portion 14. Reinforces 18 and 19 are joined and arranged on the inner surface of the upper wall that becomes the compression side due to the valley bending deformation in the second bending promoting portion 15.

  As a result, the above-described shaping of the rear side member 11 and the setting of the strength distribution in the vehicle front-rear direction can be advantageously performed, as well as the reduction of the crushing reaction force of the front and rear bending promoting portions 14, 15. By supplementing with 19, it is possible to advantageously secure the required amount of collision energy absorption in terms of design.

  On the other hand, the rear suspension member 21 has a substantially planar frame shape with a pair of left and right side members 24 and a pair of front and rear cross members 25, 26, and an arm portion 26A on the outer side in the vehicle width direction of the rear cross member 26. Is extended obliquely backward. The end portion of the arm portion 26 </ b> A is provided with the rear fastening portion 23 described above, and the strength of the arm portion 26 </ b> A is set lower than the other portions of the rear suspension member 21.

  As a result, it is possible to secure a crushing stroke region S1 having a required dimension with respect to a rear collision of the vehicle and easily obtain a required energy absorption amount. And since the shape retention area | region S2 can be ensured in front of this crushing stroke area | region S1, by mounting high voltage components, such as an inverter, in this shape retention area | region S2 in an electric vehicle etc., for example at the time of the rear surface collision of the said component The protective effect can be enhanced.

  Further, in the present embodiment, a required offset amount L is set at the connection point of the fastening portion 23 at the end of the arm portion 26 </ b> A of the rear suspension member 21 and the rear end constituent portion of the rear side member 11.

  As a result, the rear side member 11 is crushed and deformed from the beginning of the collision to absorb energy at the time of the rear collision of the vehicle, and the rear suspension member 21 is crushed and deformed from the middle of the collision to absorb energy.

  As a result, as shown by the G1 line in FIG. 9, the G control for reducing the increase in the vehicle deceleration synthesized by the rear side member reaction force a and the rear suspension member reaction force b can be performed well, and the load on the occupant is reduced. Can be reduced. 9 represents the vehicle deceleration when the rear side member 11 and the rear suspension member 21 are crushed and deformed almost simultaneously.

  Here, in the rear body structure of an automobile, there is a demand for shortening the rear extension length of the rear side member 11 in order to increase the degree of freedom of vehicle body design. Energy absorption due to crushing deformation is reduced.

  Thus, if the rear suspension member 21 can be effectively functioned as an energy absorbing member while the rear extension length of the rear side member 11 is shortened, the shortage of energy absorption can be compensated. It's not enough.

  On the other hand, in the present embodiment, as described above, the rear suspension member 21 can be effectively functioned as an energy absorbing member, and in addition, G control for reducing an increase in vehicle deceleration can be performed satisfactorily. The vehicle body design requirement for shortening the rear extension length of the vehicle can be satisfactorily met by satisfying countermeasures against rear collisions.

  As described above, the present invention can be effectively applied to the rear structure of the vehicle body, but can of course be applied to the front structure of the vehicle body. In this case, the vehicle body side member is the front side member and the suspension. The member corresponds to the front suspension member, and the vehicle body end side means the front end of the vehicle body.

11 ... Rear side member (vehicle body side member)
11A ... Member base 11B ... Kick-up part 11C ... Member general part 14 ... First bending promotion part 15 ... Second bending promotion part 16 ... Lower member 17 ... Upper members 18 and 19 ... Reinforce 21 ... Rear suspension member (suspension member) )
22.23 ... Fastening part 24 ... Side member 25/26 ... Cross member

Claims (6)

A pair of left and right vehicle body side members arranged in the vehicle front-rear direction on both sides in the vehicle width direction at the front or rear of the vehicle body;
Suspension members connected and arranged substantially parallel to the vehicle body side member by fastening portions on the vehicle body end side and the vehicle body center side on the lower side of the vehicle body side member,
The vehicle body side member is set at a portion corresponding to the front and rear fastening portions, and a first bending promoting portion that promotes a mountain-fold deformation with respect to an axial input at the time of a vehicle collision, A second bending promoting portion that is set at a portion closer to the vehicle body than the fastening portion and promotes valley deformation with respect to the axial input,
The vehicle body end side serving as the axial direction input end of the vehicle body side member is the cross-sectional center position of the portion where the first bending promotion portion is set and the cross-sectional center position of the portion where the second bending promotion portion is set The vehicle body structure is characterized in that it is set to be offset upward and downward with respect to the center position of the cross section at the end of the vehicle. The vehicle body side member includes a member base portion connected to the floor skeleton member, a kick-up portion that rises inclined from the member base portion, and a member general portion that extends substantially horizontally from the kick-up portion,
The suspension member is connected and disposed substantially horizontally across the lower surface of the member general portion of the vehicle body side member and the lower surface of the lower side of the kick-up portion by the front and rear fastening portions,
While setting the first bending promotion portion at the vehicle longitudinal direction intermediate position of the member general portion corresponding to the intermediate portion of the front and rear fastening portions,
The said 2nd bending acceleration | stimulation part was set to the connection position of the said member base part and the said kick-up part which become a vehicle body center side rather than the fastening part of the said vehicle body center side. Auto body structure.   The vehicle body side member is formed in a closed cross section in which an upper member and a lower member are joined, and an inner surface of a lower wall that becomes a compression side due to mountain bending deformation in the first bending promoting portion, and a valley in the second bending promoting portion. 2. The vehicle body structure according to claim 1, wherein a reinforcement is jointly disposed on the inner surface of the upper wall that becomes the compression side by bending deformation. The suspension member includes a pair of left and right side members extending in the vehicle front-rear direction, and a pair of front and rear cross members connecting the side members,
The fastening portion on the vehicle body end side is set at one end of the arm portion extending toward the vehicle body end portion on one side of the cross member, and the strength of the arm portion is set to the other part of the suspension member. The vehicle body structure according to any one of claims 1 to 3, wherein the vehicle body structure is set lower than the vehicle body.   The connection point of the fastening portion of the vehicle body side member on the vehicle body end side of the suspension member is set to a position offset from the vehicle body end side end of the vehicle body side member to the vehicle center side. Item 5. The vehicle body structure according to any one of Items 1 to 4.   6. The vehicle body structure according to claim 1, wherein the vehicle body side member and the suspension member are a rear side member and a rear suspension member disposed at a rear portion of the vehicle body.

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