JP2008247291A - Vehicle body structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle body structure capable of improving collision energy absorbing performance and crushing characteristic at the time of collision. <P>SOLUTION: This structure comprises a pair of front side members 1, 1 whose front ends are coupled to both ends of a front bumper 12 via a collision absorbing part 13, front side member upper members 2, 2, which are arranged above the respective front side members and whose front ends are connected to the respectively side members, and a front side member lower member 3, which is arranged below the respective front side members and whose front end is connected with the respective side members. Rear ends 3Ab, 3Bb of the front side member lower member 3 connected to a pair of side sills 17, 17 arranged in a vehicle width direction W and extending in a vehicle forward and backward direction F, and floor side members 40, 40 in parallel to the side sills. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an automobile body structure.

  As a structure of the front part of the vehicle body, a front side member extending in the front-rear direction of the vehicle body is arranged in the vehicle body width direction at the vehicle body front part. Between each front side member, an engine, transmission, etc. are arranged. Considering the position of the front wheel when the steering is turned to the maximum (hereinafter, maximum steering), the position of the front wheel at the maximum steering position is the front. In order to avoid interference with the side member, a concave portion is formed on the vehicle body longitudinal direction intermediate portion of the front side member on the vehicle body width direction outer side toward the vehicle body width direction inner side. Further, it is preferable that the front side member that has the highest amount of absorption of the collision energy of the automobile at the time of the collision is crushed in order from the front end of the front side member to the rear end of the member.

  When a recess is provided in the front side member as in a conventional vehicle body structure, the cross-sectional center line at the front end of the front side member and the cross-sectional center line at the recess are shifted in the vehicle body width direction. Further, when the cross-sectional area of the front end of the front side member is compared with the cross-sectional area of the recess of the front side member, the cross-sectional area of the front side member at the recess is smaller than the cross-sectional area of the front end of the front side member. For this reason, the concave portion of the front side member becomes a fragile portion, and a bending moment in the vehicle body width direction is generated in the intermediate portion of the front side member in the longitudinal direction of the vehicle body due to the input acting along the cross-sectional center line of the front end of the front side member. It is easy, and the concave portion of the front side member may be deformed earlier than the front end portion of the front side member at the time of collision.

  Therefore, a front side member upper member and a front member disposed above and below each front side member are disposed at the rear ends of a pair of front side members whose front ends are coupled to both ends of the front bumper via shock absorbers, respectively. The present applicant has a vehicle body structure that couples side member lower members and absorbs the energy at the time of collision by dispersing the collision energy of the automobile at the time of collision from the front side member to the front side member upper member and the front side member lower member vertically. Is proposed in Japanese Patent Application Laid-Open No. H11-228707.

JP 2006-143178 A

  Although the vehicle body structure proposed in Patent Document 1 can also absorb energy at the time of collision, there is still room for ingenuity in terms of more efficiently absorbing energy at the time of collision and crush characteristics.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle body structure capable of improving collision energy absorption performance and crushing characteristics during a collision.

  In the present invention, when improving the collision energy absorption performance and crushing characteristics at the time of a collision, the problem is solved by revising the shape of the member and the coupling method, particularly focusing on the front side member lower member.

  That is, according to the first aspect of the present invention, the front bumper is disposed above the front side members and the pair of front side members each having the front end coupled to both ends of the front bumper via the shock absorbing portion. A front side member having a front side member upper member connected to a side member and a front side member lower member disposed below each front side member and having a front end connected to each front side member. The rear end of the lower member is connected to a pair of side sills arranged in the vehicle body width direction and extended in the vehicle body longitudinal direction, and a floor side member arranged in parallel with the side sills.

  According to a second aspect of the present invention, the rear end of the front side member lower member is shaped to be widened toward the vehicle body width direction. In the third aspect of the invention, the rear end of the front side member lower member is attached to each side sill. And dash cross members connected to the floor side members.

  In the invention of claim 4, the front end side of the front side member lower member is formed more fragile than the rear end side. In the invention of claim 5, the front side member lower member is arranged on the rear end side of the front side member lower member. When a collision load is applied to the front end of the member, a fragile deforming portion that deforms later than the front end is provided.

  According to the present invention, the front side member upper member is disposed above the pair of front side members, and the front ends thereof are connected to the front side members, and the front end members are disposed below the front side members. In a vehicle body structure including a front side member lower member connected to each front side member, a pair of side sills arranged in the vehicle body width direction and extended in the vehicle body longitudinal direction at the rear end of the front side member lower member; Since these are connected to the floor side members arranged in parallel with the side sill, the collision energy input to the front side member is distributed to the front side member upper member and the front side member lower member and the front side member lower. The collision energy transmitted to the member It will be distributed to the Le a floor side member. For this reason, the collision energy at the time of the collision can be efficiently transmitted and distributed to the rear of the vehicle body. Further, since the collision energy transmitted to the front side member lower member is distributed to the side sill and the floor side member, the rigidity of the entire front side member lower member can be made lower than before, and the front side member lower member The plate thickness can be reduced and the weight of the vehicle body can be reduced.

  According to the present invention, since the rear end of the front side member lower member has a shape that widens toward the end in the vehicle body width direction, the overall shape and position of the front side member lower member are not changed, and By widening only the end in the vehicle body width direction, the side sill and the floor side member can be easily connected.

  According to the present invention, the rear end of the front side member lower member is coupled to the dash cross member connected to each side sill and the floor side member. Can be combined without changing the rear end shape of the front side member lower member, and the energy of the collision at the time of the collision can be efficiently transferred to the rear of the vehicle body while reducing the weight while sharing parts Can be achieved.

  According to the present invention, since the front end side of the front side member lower member is made weaker than the rear end side of the front side member lower member, when collision energy is transmitted from the front side member to the front side member lower member, The front side member lower member can be reliably deformed, and the collision energy at the time of a collision can be efficiently reduced while maintaining transmission dispersion characteristics to the rear of the vehicle body, while reducing the weight of the front side member lower member. Can be absorbed.

  According to the present invention, the front side member lower member is provided with the fragile deformation portion that is deformed later than the front end when a collision load is applied to the front end of the front side member lower member when the front side member lower member is subjected to a collision load. The collision energy that was transmitted to the member lower member and could not be absorbed by the deformation of the front end side of the member can be absorbed by the deformation of the weak deformation part, and the collision energy at the time of the collision can be more efficiently distributed to the rear of the vehicle body It is possible to reduce the weight while maintaining the characteristics.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the figure, F represents the front of the vehicle body, R represents the rear of the vehicle body, W represents the vehicle body width direction, and In represents the vehicle body width direction inner side. As shown in FIGS. 1 and 2, in the vehicle body structure according to the present invention, the upper parts of the left and right front pillar lowers 10 are joined by cowl tops 11, and the middle part of each front pillar lower 10 is joined by a dash cross member upper 16. ing. Although not shown, a cabin is formed on the vehicle body direction side of the front pillar lower 10.

  Below each front pillar 10, a pair of side sills 17, 17 arranged in the vehicle body width direction W and extended in the vehicle body longitudinal direction FR, and these side sills 17, 17 are juxtaposed and extend in the vehicle body longitudinal direction FR. The provided floor side members 40, 40 are arranged. The front ends 17a and 17a of each side sill are joined to the lower part of each front pillar lower 10 by welding or the like. The front ends 40a, 40a of the floor side members are joined to the front ends 17a, 17a of the side sills by welding or the like via dash cross member lowers 15A, 15B respectively extending in the vehicle body width direction W. In this embodiment, the dash cross member lowers 15A and 15B are not extended over the entire width of the vehicle body, but are long enough to connect each side sill 17 and each floor side member 40. It is one element of securing cabin strength while being lighter than the one extended over the entire body width region.

  A pair of left and right front side members 1, 1 each having front ends 1a, 1a coupled to both ends of a front bumper 12 via impact absorbing portions 13, 13 at the vehicle body front F rather than the front pillar lowers 10, respectively, A pair of left and right front side member upper members 2 and 2 which are disposed above the front side member 1 and whose front ends 2a and 2a are respectively connected to the front side members 1, and disposed below the front side members 1. A front side member lower member 3 whose front ends 3Aa and 3Ba are connected to the front side members 1 is disposed.

  The front side member upper members 2 and 2 are disposed above the central axis of the front wheel 30 as shown in FIG. As shown in FIG. 3, the front side member uppers 2 and 2 and the tops 31 of the front wheels are located at substantially the same height, but the front inner side 32 or the front wheels of the front wheel 30 may interfere during maximum steering. Since the rear inner side 33 of the 30 is located lower than the front side member upper 2, the front side member upper 2 and the front inner side 32 or the rear inner side 33 of the front wheel 30 do not interfere with each other.

  As shown in FIGS. 1 and 2, the front side member lower 3 has an arm portion 3A extending from the dash cross member lowers 15A and 15B toward the front of the vehicle body at a level below the center axis of the front wheel 30 and substantially the same as the floor 4. , 3B and a base portion 3C that connects both arm portions. The front side member lower 3 is integrally formed by casting, for example.

  A front cross member 50 extending in the vehicle width direction is connected between the front ends 3Aa and 3Ba of the front side member lower members. The rear ends 3Ab, 3Bb of the front side member lower members are each formed in a fan shape that expands toward the end in the vehicle body width direction W, and are fastened to the dash cross member lowers 15A, 15B by bolts 50, whereby each side sill 17 Are connected to the floor side members 40, respectively.

  As shown in FIG. 4, the arm portions 3 </ b> A and 3 </ b> B, like the front side member uppers 2 and 2, from the vehicle body width direction outer side to the vehicle body width direction so that the front inner side 32 or the rear inner side 33 of the left and right front wheels 30 do not interfere. A concave portion directed toward the inner In side is formed, and the planar shape thereof is substantially X-shaped. For this reason, the front side member lower 3 is formed with a recess toward the vehicle body width direction inner side In from the front inner side 32 of the front wheel 30 or the rear inner side 33 of the front wheel 30 that may interfere during maximum steering. The front side men's lower 3 and the front inner side 32 or the rear inner side 33 of the front wheel 30 do not interfere with each other.

  The front side member lower member 3 is formed such that its front ends 3Aa and 3Ba are more fragile than the rear ends 3Ab and 3Bb. This point will be described with reference to FIG. 5. The regions of the arm portions 3A and 3B where the front ends 3Aa and 3Ba indicated by the symbol A are located are the central region indicated by the symbol B and the rear ends 3Ab and 3Bb indicated by the symbol C. The plate thickness is formed thinner than the area to be processed. In the region C where the rear ends 3Ab and 3Bb are located, fragile deforming portions 60 and 60, which are deformed later than the front ends 3Aa and 3Ba when a collision load is applied to the front ends 3Aa and 3Ba, are provided. In this embodiment, the fragile deformable portions 60, 60 are openings that penetrate in the vertical direction of the vehicle body in the fan portion located in front of the vehicle body relative to the rear end attachment portions 3Ac, 3Bc attached to the dash cross member lowers 15A, 15B by the bolts 50. It is configured by forming the part 61.

  In this embodiment, the fragile deforming portions 60, 60 are formed by providing the opening portions 61, 61 at the rear ends 3Ab, 3Bb located in the region C, respectively. The fragile deformable portions 60, 60 may be configured by a method of partially reducing the thickness of the region C.

  According to the vehicle body structure having such a configuration, the rear ends 3Ab and 3Bb of the front side member lower member 3 are disposed in the vehicle body width direction W and extended in the vehicle body front-rear direction, and the side sills 17 and 17 are extended. Are connected to the floor side members 40, 40 arranged in parallel with each other, the collision energy input to the front side members 1, 1 is distributed to the front side member upper member 2 and the front side member lower member 3. Further, the collision energy transmitted to the front side member lower member 3 is transmitted from the front ends 3Aa and 3Ba to the rear ends 3Ab and 3Bb, and is distributed to the side sills 17 and 17 and the floor side members 40 and 40, respectively. . In this transmission path, the region A where the front end members 3Aa and 3Ba having the least strength in the front side member lower member 3 are first deformed and crushed rearward to absorb the collision energy at the time of the collision. When the collision energy cannot be absorbed by crushing the area A, the openings 61 and 61 are formed, so that the fragile deformation parts 60 and 60 are provided, the area C is deformed, and the rear side is crushed and the impact energy is reduced. In addition to absorbing, it is distributed and transmitted to the side sills 17 and 17 and the floor side members 40 and 40, respectively. For this reason, it is possible to transmit and disperse the collision energy to the rear of the vehicle more efficiently than in the conventional configuration. Further, since the collision energy transmitted to the front side member lower member 3 is distributed to each side sill 17 and each floor side member 40, the front side member lower member 3 can be made thin, and at the same time, the weight of the vehicle body can be reduced. Can be achieved.

  Since the rear ends 3Ab, 3Bb of the front side member lower member have a shape that widens toward the end in the vehicle body width direction W, the rear end 3Ab of the lower member is not changed without changing the overall shape and position of the front side member lower member 3. , 3Bb can be easily connected to the side sill 17 and the floor side member 40 by widening in the vehicle body width direction W. Further, the rear ends 3Ab and 3Bb are connected to the dash cross members 15A and 15B connected to the side sills 17 and the floor side members 40, respectively. The front side member lower member 3 can be coupled without changing the shape of the rear end of the front side member lower member 3, and the energy of the collision at the time of the collision can be efficiently reduced while maintaining the transmission dispersion characteristic to the rear of the vehicle body. Sharing can be achieved.

  Since the area A on the front end 3Aa, 3Ba side of the front side member lower member 3 is formed more fragile than the area C on the rear end 3Ab, 3Bb side, collision energy is transmitted from the front side member 1 to the front side member lower member 3. When this occurs, the front ends 3Aa and 3Ba of the front side member lower member 3 can be reliably deformed, and collision energy can be absorbed. In the region C on the rear end front end 3Ab, 3Bb side of the front side member lower member, a fragile deforming portion 60 is provided that deforms later than the front ends 3Aa, 3Ba when a collision load is applied to the front ends 3Aa, 3Ba. Therefore, the collision energy that is transmitted to the front side member lower member 3 and cannot be absorbed by the deformation of the region A of the front ends 3Aa and 3Ba can be absorbed by the deformation of the fragile deformation portion 60, and the collision energy at the time of the collision can be further reduced. The transmission dispersion characteristic toward the rear of the vehicle body can be maintained efficiently.

  In the above embodiment, the rear ends 3Ab, 3Bb of the front side member lower member 3 are connected to the side sills 17 and the floor side members 40 via the dash cross members 15A, 15B. This is because when the rear ends 3Ab and 3Bb are large in fan shape, it becomes difficult to press-mold and good handling of components after molding is considered. However, in the case of a vehicle body structure in which the distance between each side sill 17 and each floor side member 40 is not wide, the rear ends 3Ab and 3Bb are arranged so as to straddle each side sill 17 and each floor side member 40, and directly with bolts 50. You may make it conclude. In this case, in order to ensure the cabin strength, it is preferable to provide a dash cross member extending over the entire vehicle body width region as in the prior art.

It is the perspective view which looked at the main structure of the vehicle body structure concerning this invention from the vehicle body upper direction. It is the top view which looked at the main structure of the vehicle body structure concerning this invention from the vehicle body downward direction. It is the schematic block diagram which looked at the relationship between the vehicle body structure concerning this invention and a front wheel from the vehicle body side. It is the schematic block diagram which looked at the relationship between the vehicle body structure concerning this invention and a front wheel from the vehicle body upper direction. It is a perspective view which shows the structure of the front side member lower member used as the main structure of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1 A pair of front side member 2,2 Front side member upper member 3 Front side member lower member 3Aa, 3Ba Front end of front side member lower member 3Ab, 3Bb Rear end of front side member lower member 12 Front bumper 13 Shock absorption part 15A, 15B Dash cross member 17, 17 Pair of side sills 40, 40 Floor side member 60, 60 Fragile deformation part W Body width direction FR Body direction

Claims (5)

A pair of front side members whose front ends are coupled to both ends of the front bumper via shock absorbers, and front side members which are arranged above the front side members and whose front ends are connected to the front side members An upper member and a front side member lower member which is disposed below each front side member and whose front end is connected to each front side member;
The rear end of the front side member lower member is connected to a pair of side sills arranged in the vehicle body width direction and extended in the vehicle body longitudinal direction, and a floor side member arranged in parallel with the side sills. Body structure.   2. The vehicle body structure according to claim 1, wherein a rear end of the front side member lower member is formed so as to expand toward the end in the vehicle body width direction.   3. The vehicle body structure according to claim 1, wherein a rear end of the front side member lower member is coupled to a dash cross member connected to each side sill and each floor side member.   4. The vehicle body structure according to claim 3, wherein the front side member lower member has a front end side that is weaker than a rear end side.   The fragile deforming portion that deforms later than the front end when a collision load is applied to the front end of the front side member lower member is provided on the rear end side of the front side member lower member. 4. The vehicle body structure according to 4.

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