JP2006312349A - Underfloor skeleton structure in vehicle central part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an underfloor skeleton structure in a vehicle central part excellent in operation stability and transmitting impact at collision from a front frame to a rear side frame. <P>SOLUTION: The underfloor skeleton structure in the vehicle central part is provided with a pair of left and right front frames 1, 1 arranged along a longitudinal direction of the vehicle; side sills 2, 2 positioned at outer sides of the respective front frames 1, 1 and extending in a longitudinal direction along a side part of the vehicle body; the rear side frames 3, 3 joined to rear ends of the side sills 2, 2 and arranged at both left and right sides of a rear part of the vehicle body; a rear/front cross member 6 joined with rear ends of the front frames 1, 1 and arranged in a width direction of the vehicle; and a trans bar 10 having one end fastened/fixed to the rear side frame 3 and the other end fastened/fixed to the rear/front cross member 6 joined with a rear end of the front frame 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an underfloor skeleton structure in a vehicle central portion including a front frame, a side sill, and a rear side frame.

  Conventionally, a vehicle skeleton structure mainly includes a front frame, a side sill, and a rear side frame that are disposed substantially parallel to the left and right sides with respect to the longitudinal direction of the vehicle. The rear end of the front frame was joined to a cross member disposed so as to be orthogonal to the front frame, and both ends of the cross member were joined to the rear part of the side sill. And the front part of the rear side frame was joined to each edge part of the cross member to which the rear part of the side sill was joined.

  There is a difference in height between the front frame and the rear side frame connected via the cross member. This is because an inclined portion is provided on the front side of the left and right rear side frames so as to correspond to a portion where the rear wheel is disposed, and the inclined portion is slightly inner to avoid interference with the rear wheel. And is shaped to extend upward.

  Therefore, in the above-described skeleton structure, the front frame and the rear side frame are divided at a portion where a difference in height occurs. For this reason, there is a possibility that a difference in rigidity occurs between the vehicle body rigidity on the front side and the vehicle body rigidity on the rear side, which may be one of the factors that reduce the steering stability.

  Further, since the height difference is generated between the front frame and the rear side frame, the load transmission from the front side to the rear side of the vehicle is difficult to be promoted. For this reason, for example, at the time of a front collision, the impact is not efficiently transmitted to the rear side frame, causing a shear displacement in which the front frame and the side sill are displaced in the front-rear direction, causing deformation of the cabin.

  In order to deal with these problems, the front frame and the rear side frame are continuously connected without being divided to increase the vehicle body rigidity from the front side to the rear side of the vehicle as one frame, and the load transmission efficiency is improved. A skeletal structure that is promoted and strong against collisions is desired.

For example, in Patent Document 1, a seat cross member is disposed along the vehicle width direction at the rear portion of a front floor panel, and a pair of left and right rear side members are respectively disposed behind both ends of the seat cross member. A rear center cross member is passed to the rear, and the left and right ends of the suspension member front end are attached to the front of the rear side member, and the left and right ends of the suspension member rear end are attached to the rear center cross member. In this vehicle body structure, there is disclosed a technique for providing a pair of left and right stays that connect the vicinity of the front end mounting portion of the suspension member and a position slightly inward from both ends of the seat cross member.
JP 2000-168614 A

  However, in the technique disclosed in Patent Document 1, the stay is connected to the vicinity of the front end attachment portion of the suspension member attached to the rear center cross member and the position slightly inward from the end portion of the seat cross member. Therefore, it is difficult to eliminate the difference in rigidity between the front side and the rear side in the vehicle body rigidity of the frame.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an underfloor skeleton structure in the center of a vehicle that has excellent steering stability and transmits an impact at the time of collision from a front frame to a rear side frame.

  The underfloor skeleton structure in the center of the vehicle according to the present invention is a pair of left and right front frames disposed along the front-rear direction of the vehicle, and is positioned outside the front frames and extends in the front-rear direction along the side of the vehicle body. An extended side sill, a rear side frame that is joined to the rear end of the side sill and arranged on the left and right sides of the rear part of the vehicle body, and a rear front cross that is arranged in the vehicle width direction and joined to the rear end of the front frame A member, and a plate-like connecting member whose one end is fastened and fixed to the rear side frame and whose other end is fastened and fixed to a rear front cross member to which the rear end of the front frame is joined.

  According to this configuration, the front frame and the rear side frame are connected by the plate-like member to form one skeleton, so that the support rigidity of the rear side frame is increased and the impact at the time of the front collision is the front side of the vehicle. To the rear rear side frame.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in steering stability, and can implement | achieve the underfloor frame | skeleton structure in the vehicle center part which transmits the impact at the time of a collision from a front frame to a rear side frame.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 6 relate to an embodiment of the present invention, FIG. 1 is a schematic plan view seen from the outdoor side, explaining the configuration of a vehicle body frame, and FIG. 2 shows the configuration of a truss bar and a tie-down plate attached to the truss bar. FIG. 3 is a diagram for explaining a state in which the truss bar is fastened and fixed to the rear front cross member and the rear side frame. FIG. 4 is a view of the truss bar fastened to the rear front cross member and the rear side frame as viewed from the outdoor side. FIG. 5 is a view of the truss bar fastened and fixed to the rear front cross member and the rear side frame when viewed from the outside of the vehicle, and FIG. 6 is a view of the other configuration example of the vehicle body frame when viewed from the outdoor side. FIG. In the following description, the same symbols are attached to the left and right members for the left and right symmetrical members, and the description is simplified.

  As shown in FIG. 1, the main skeleton of the vehicle is located on the side of the vehicle body on a pair of left and right front frames 1, 1 arranged along the front-rear direction of the vehicle, and outside each front frame 1, 1. The side sills 2 and 2 extend in the front-rear direction, and the rear side frames 3 and 3 are disposed on the left and right sides of the rear part of the vehicle body at the rear end of the side sills 2 and 2.

  The front frames 1, 1 are formed in a substantially U-shaped bent shape having a bent portion 1 a in the middle portion, and a first tunnel cross member 4 disposed in the front side portion with respect to the vehicle width direction. Are joined. A second tunnel cross member 5 arranged in the width direction is joined to a position corresponding to the bent portion 1a, which is an intermediate portion of the front frames 1 and 1. Further, the rear ends of the front frames 1 and 1 are joined to a rear front cross member 6 disposed in the width direction. The front frames 1 and 1 having the bent portion 1a in the present embodiment gradually expand outward as they move from the vicinity of the bent portion to which the second tunnel cross member 5 is joined to the front side and the rear side. Has been extended to. The extending direction on the rear side of the bent portions 1 a of the front frames 1, 1 is set in the vicinity of a later-described inclined portion 3 a provided on the rear side frame 3. The second tunnel cross member 5, the front frame 1 from the bent portion 1a to the front side, and the front frame 1 from the bent portion 1a to the rear side are formed as a trifurcated portion that is divided into approximately equal parts.

  The rear portions of the side sills 2 and 2 are joined to the respective end portions of the rear front cross member 6. Further, the front portions of the rear side frames 3 and 3 are joined to the rear portions of the side sills 2 and 2 and to the respective end portions of the rear front cross member 6. A rear cross member 7 is joined to an intermediate portion of the rear side frames 3 and 3.

  An inclined portion 3a is provided slightly ahead of the portion where the rear wheels 8, 8 of the left and right rear side frames 3, 3 are disposed. The inclined portion 3a is slightly inwardly curved and extends upward in order to avoid interference with the rear wheels 8,8. That is, by providing the inclined portions 3a in the rear side frames 3 and 3, there is a difference in height between the front side of the rear side frame and the rear side of the intermediate portion as shown in FIG. It is higher than the front side.

  In the vicinity of the inclined portion 3a of the rear side frames 3 and 3, one end portion of a truss bar 10 which is a plate-like connecting member serving as a stiffening member and a load transmitting member is fastened and fixed by a bolt described later, and the other end portion of the truss bar 10 is It is fastened and fixed to a rear front cross member 6 to which the rear ends of the front frames 1 and 1 are connected by bolts described later. In this fastened state, the truss bar 10 is arranged in substantially the same direction with respect to the extending direction of the front frames 1, 1, in other words, linearly. Thus, the front frames 1 and 1 and the rear side frames 3 and 3 are connected by the truss bar 10 to form one skeleton.

  An area indicated by a two-dot chain line surrounded by the left and right rear side frames 3, 3, the rear front cross member 6, and the rear cross member 7 is secured as an area where the fuel tank 21 is disposed. Is disposed below the fuel tank 21. Reference numerals 4a and 5a are tunnel-shaped portions, reference numeral 22 is a differential device, reference numeral 23 is a front wheel, reference numeral 24a is a first seat cross member, reference numeral 24b is a second seat cross member, reference numeral 25 is an engine, and reference numeral 26 is a transmission. A propeller shaft 27, an exhaust pipe (not shown), a propeller shaft center bearing (not shown), and the like are arranged in the tunnel shape portions 4a and 5a. The first and second seat cross members 24a and 24b are provided on the indoor side.

  As shown in FIG. 2, the truss bar 10 has an elongated flat plate bar portion 11 whose end portion is fixed to the rear front cross member 6, and an end portion that is gradually fixed near the inclined portion 3 a of the rear side frame 3. An end portion configured to expand is provided with a flat plate expanding portion 12 having a wide width. The truss bar 10 has a cross-sectional shape in which as many ridge lines as possible are set in the longitudinal direction in order to provide light weight, low cost, and strength and rigidity.

  A bent portion 13 corresponding to the height generated between the front side of the rear side frames 3 and 3 and the rear side of the intermediate portion is provided at the intermediate portion of the truss bar 10. For example, one through hole 11a into which the fastening bolt 14 is inserted and disposed is formed at a predetermined position of the flat bar portion 11 of the truss bar 10, and the fastening bolt 14 is provided at a predetermined position of the flat plate expanding portion 12 of the truss bar 10. For example, two through holes 12a, 12a to be inserted are provided. Further, a through hole 13a through which a tie-down fixing bolt 16 for fastening and fixing a tie-down plate 15 (to be described later) to the truss bar 10 is inserted in the vicinity of the rising portion of the bent portion 13 provided in the truss bar 10 is provided. Is provided.

  The tie-down plate 15 is a tying member that serves as a hook member to which a tie-down rope or the like is tied up and a reinforcing member that stiffens the rigidity in the vicinity of the bent portion 13 of the truss bar 10. It is configured to be bent into a predetermined shape. The bent surface portion 15a formed on the tie-down plate 15 is provided with a hook through hole 15b to which a tie-down rope (not shown) is secured. A tie-down fixing bolt 16 is provided at one end of the tie-down plate 15 with a first mounting portion 15d having holes 15c and 15c through which fastening bolts 14 are inserted. A second attachment portion 15f having a through hole 15e to be inserted is provided. Reference numeral 17 denotes a fastening nut which is screwed to the fastening bolt 14. Reference numeral 18 denotes a tie-down fixing nut which is screwed to the tie-down fixing bolt 16.

  The fastening and fixing of the truss bar 10 to the rear side frames 3 and 3 and the rear front cross member 6 will be described with reference to FIGS. As shown in FIG. 3, through holes 6 a and 3 b through which fastening bolts 14 are inserted are formed at predetermined positions of the rear front cross member 6 and the rear side frames 3 and 3.

  When the truss bar 10 is fastened and fixed to the rear side frames 3 and 3 and the rear front cross member 6, first, the tie-down plate 15 is disposed on the truss bar 10. Specifically, the tie-down fixing nut 16 is inserted through the through-hole 15e provided in the tie-down plate 15 and the through-hole 13a provided in the vicinity of the bent portion 13 of the truss bar 10. 18 is screwed. At this time, the center positions of the through holes 15c and 15c provided in the tie-down plate 15 and the center positions of the through holes 12a and 12a provided in the flat plate expanding portion 12 of the truss bar 10 are substantially matched.

  Next, the truss bar 10 on which the tie-down plate 15 is disposed is fastened and fixed. Specifically, the through hole 11 a provided at the end of the flat bar 11 is disposed opposite to the through hole 6 a provided in the rear front cross member 6, while provided in the flat plate expanding portion 12. The through holes 12 a and 12 a are arranged to face the through holes 3 b and 3 b provided in the rear side frame 3. Thereafter, the fastening bolt 14 is inserted into the through holes 11 a and 6 a and screwed into the fastening nut 17, and the fastening bolt 14 is inserted into the through holes 15 c, 12 a and 3 b and screwed into the fastening nut 17. . During the screwing, the bolt fastening on the flat bar portion 11 side, the two bolt fastenings on the flat plate expanding portion 12 side, or the one bolt fastening on the flat plate expanding portion 12 side, the bolt fastening on the flat bar portion 11 side, The fastening operation is performed in the order of fastening the other bolt on the flat plate expanding portion 12 side.

  As a result, as shown in FIGS. 3 and 4, the truss bar 10 to which the tie-down plate 15 is attached is firmly fixed to the rear side frame 3 and the rear front cross member 6, and the centroid of the truss bar 10 indicated by arrow A is shown. Is changed to the centroid indicated by the arrow B, and the rigidity of the truss bar 10 having the bent portion 13 is increased. Further, the truss bar 10 is fastened and fixed in a state where the rotational component is suppressed by so-called three-point fastening using three fastening bolts 14. In this fastened and fixed state, the tie-down plate 15 is fastened integrally with the truss bar 10. Further, in this fastened and fixed state, as shown in FIG. 5, a hook through hole 15 b formed in the bent surface portion 15 a of the tie-down plate 15 fastened and fixed integrally to the truss bar 10 is disposed in the vicinity of the rear wheel 8. The

  In this manner, the support rigidity and strength of the rear side frame 3 are increased by fastening and fixing the ends of the truss bar 10 to which the tie-down plate 15 is integrally fastened to the rear side frame 3 and the rear front cross member 6. Thus, the lateral rigidity with which the rear side frame 3 falls in the lateral direction can be greatly improved. As a result, the steering stability can be improved and the difference in rigidity between the front-side vehicle body rigidity and the rear-side vehicle body rigidity is reduced.

  Further, the front frame 1 is provided with a bent portion 1a, the extending direction of the front frame 1 that expands from the bent portion 1a toward the rear side is set to the rear side frame 3, and the truss bar 10 is attached to the front frames 1 and 1. By arranging linearly with respect to the extending direction, the number of paths for dispersing the load at the time of collision increases, and a skeleton structure that is strong against the load at the time of collision can be realized.

  Further, the truss bar 10 is linearly arranged with respect to the extending direction of the front frames 1 and 1, and the second tunnel cross member 5 is joined to the bent portion 1 a of the front frame 1, thereby By providing a trident portion composed of the front frame 1 and the second tunnel cross member 5 in the vicinity of the bent portion 1a, in addition to increasing the rigidity of the front frame, the rigidity of the second tunnel cross member 5 is increased. By increasing the transmission of vibration from the propeller shaft 27, noise generated by the vibration can be reduced.

  In addition, the fuel tank 21 can be protected when the wheel is removed by arranging the truss bar 10 to which the tie-down plate 15 is integrally fastened and fixed below the fuel tank 21. Thus, the fuel tank capacity can be increased by bringing the lower end position of the fuel tank closer to the truss bar 10.

  In the present embodiment, the front frame 1 has a bent shape having a bent portion 1a. However, the configuration of the front frame 1 is not limited to this, and a straight front frame 1A as shown in FIG. There may be. Also in this configuration, the end portion of the truss bar 10 is fastened and fixed to the rear side frame 3 and the rear front cross member 6, thereby increasing the support rigidity and strength of the rear side frame 3, and the rear side frame 3 falling sideways. The rigidity can be greatly improved. As a result, the steering stability can be improved and the difference in rigidity between the front-side vehicle body rigidity and the rear-side vehicle body rigidity is reduced.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

Schematic plan view seen from the outdoor side explaining the configuration of the body frame The figure explaining the composition of a truss bar and a tie-down plate attached to this truss bar The figure explaining the state which fastens and fixes a truss bar to a rear front cross member and a rear side frame A perspective view of the truss bar fastened and fixed to the rear front cross member and the rear side frame when viewed from the outdoor side View when the truss bar fastened to the rear front cross member and rear side frame is viewed from the outside of the vehicle Schematic plan view seen from the outdoor side explaining another configuration example of the body frame

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Front frame 1a ... Bending part 2 ... Side sill 3 ... Rear side frame 3a ... Inclination part 5 ... 2nd tunnel cross member 6 ... Rear front cross member 10 ... Truss bar 11 ... Flat bar part 12 ... Flat plate expansion part 13 ... Folding Curve 15: Tie-down plate 15a ... Bent surface 15b ... Hook through hole

Claims (4)

A pair of left and right front frames disposed along the longitudinal direction of the vehicle;
A side sill located on the outside of each front frame and extending in the front-rear direction along the side of the vehicle body;
A rear side frame that is joined to the rear end of the side sill and disposed on the left and right sides of the rear of the vehicle body;
A rear front cross member disposed in a vehicle width direction, to which a rear end of the front frame is joined;
A plate-like connecting member, one end of which is fastened and fixed to the rear side frame and the other end is fastened and fixed to a rear front cross member to which the rear end of the front frame is joined;
An underfloor skeletal structure in the center of the vehicle.   The plate-like connecting member has a bent portion at an intermediate portion between one end portion fastened and fixed to the rear side frame and the other end portion fastened and fixed to the rear front cross member, and the bent portion has the bent portion. The underfloor skeleton structure in the vehicle central portion according to claim 1, further comprising a reinforcing member that stiffens the rigidity of the curved portion.   The front frame has a bent shape having a bent portion in the middle, the rear side of the bent portion of the front frame extends toward the rear side frame, and the front frame extends toward the rear side frame. The underfloor skeleton structure in the vehicle central portion according to claim 1, wherein the plate-like connecting members are linearly arranged on the rear side of the bent portion of the frame.   The underfloor skeleton structure in the vehicle center portion according to claim 3, wherein a tunnel cross member disposed in the vehicle width direction is joined to the bent portion of the front frame having the bent portion.

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