JP4012131B2 - Rear structure of the car body - Google Patents

Description

  The present invention relates to a rear structure of a vehicle body, and more particularly to a technique for improving a structure that absorbs collision energy from the rear.

In recent years, in vehicles such as automobiles, in addition to a technique for absorbing collision energy applied from the front, development is also progressing regarding a technique for absorbing collision energy applied from the rear (see, for example, Patent Document 1). .
Japanese Patent Laid-Open No. 2002-331962

An outline of a conventional rear structure of a vehicle body according to Patent Document 1 will be described with reference to FIG.
6 (a) and 6 (b) are schematic views of the rear structure of a conventional vehicle body, and are a reprinted view of the main parts of FIGS. (A) is the perspective view of the rear part of the conventional vehicle body, (b) is the cross-sectional structure figure which looked at the rear part of the conventional vehicle body from the left side. However, the sign has been changed.

In the rear structure of the conventional vehicle body 100, a rear end panel 101 that forms the rear surface of the vehicle body is extended downward, joined to the rear ends of the left and right rear side frames 102, 102, and a rear end cross member 104 between the joined rear ends 103, 103. And the shock absorbing members 105, 105 are extended rearward from the left and right joining rear ends 103, 103.
The left and right impact absorbing members 105, 105 are fragile members that are bolted to the rear ends of the rear side frames 102, 102, and can absorb the collision energy applied from the rear of the vehicle body. 106 is a rear bumper, and 107 is a reinforcing member.

  By the way, in order to improve the absorption performance of the collision energy applied from the rear of the vehicle body 100, it is preferable to make the lengths of the impact absorbing members 105 and 105 as large as possible. However, due to restrictions on the design of the vehicle, there is a limit to projecting the shock absorbing members 105 and 105 rearward from the rear end panel 101 greatly.

  Moreover, even when the collision energy absorption performance is improved, it is required to efficiently transmit the collision energy from the shock absorbing members 105 and 105 to the rear side frames 102 and 102. Furthermore, in order to ensure the strength and rigidity of the vehicle body, it is required to secure the joining strength and joining rigidity of the rear end panel 101 to the rear side frames 102 and 102.

  Further, since the rear structure of the conventional vehicle body 100 is configured such that shock absorbing members 105 and 105 made of different members are bolted to the rear ends of the rear side frames 102 and 102, the number of parts is large and the configuration is complicated. It becomes a factor of up.

  The present invention (1) further enhances the absorption performance of the collision energy applied from the rear of the vehicle body, (2) transmits the collision energy from the rear of the vehicle body to the rear side frame very efficiently from the frame extension, (3) It is an object of the present invention to provide a technique capable of ensuring sufficient strength and rigidity of the vehicle body and (4) reducing the cost of the vehicle body.

The invention according to claim 1 is to be extended before and after the left and right rear side frames at the rear portion of the vehicle body, the rear end of these rear side frames extending rearwardly while maintaining a generally continuous contour with the rear side frames, the upper open co A low-strength frame extension consisting of a letter-shaped cross- section is integrally provided, and a vertical plate-shaped bulkhead that divides the frame in the middle of the frame in a substantially perpendicular direction is joined and fixed to the bottom and left and right sides. Te is provided, said frame extensions, extend to the rear than the rear end panels constituting a vehicle body rear surface, and the rear end panel reinforces the back with a reinforcing member, the lower end portion of the rear end panel reinforced by the reinforcing member, said bulkhead It is characterized in that it is joined to the upper end portion of the.

  In the first aspect of the present invention, the frame extension extending rearward from the rear end of the rear side frame extends to the rear of the rear end panel on the rear surface of the vehicle body. it can. As a result, the length of the frame extension can be set larger. Since the frame extension portion having a lower strength (weaker) than the rear side frame is lengthened in the front-rear direction, the absorption performance of the collision energy acting from the rear of the vehicle body can be further enhanced. In addition, since the size of the frame extension protruding rearward from the rear end panel can be suppressed, the degree of freedom in designing the vehicle body can be increased.

  Further, since the frame extension is integrally provided at the rear end of the rear side frame so as to extend rearward while maintaining a substantially continuous outer shape with the rear side frame (that is, while maintaining a generally continuous ridgeline), Can be transmitted very efficiently from the frame extension to the rear side frame.

Furthermore, since the vertical plate-shaped bulkheads are provided as joining members from the middle of the longitudinal direction of the left and right frame extensions in a direction substantially perpendicular to the longitudinal direction, and the rear end panels reinforced on the back side are joined to these bulkheads. Without providing a reinforcing member made of a member, it is possible to sufficiently secure the joining strength and joining rigidity of the rear side frame and the rear end panel whose back side with respect to the frame extension is reinforced by the reinforcing member . Therefore, for example, even when the vehicle body is twisted around an axis in the front-rear direction passing through the center of gravity of the vehicle, it is possible to sufficiently ensure the strength and rigidity of the vehicle body.

  Furthermore, since the frame extension part weaker than the rear side frame is integrally provided at the rear end of the rear side frame, the number of parts can be reduced and the configuration can be simplified. For this reason, the cost of the vehicle body can be reduced.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. “Front”, “Rear”, “Left”, “Right”, “Up”, “Down” follow the direction seen from the driver, Fr is front, Rr is rear, L is left, R is right CL indicates the vehicle width center (vehicle body center). The drawings are to be viewed in the direction of the reference numerals.

  FIG. 1 is a perspective view of a rear portion of a vehicle according to the present invention. The vehicle 10 has an opening 12 formed on the rear surface 11 of the vehicle body, and a tailgate (not shown) is attached to the roof rail 13 above the opening 12 so as to be able to swing up and down, whereby the opening 12 is opened and closed by the tailgate. This is a hatchback type automobile. 14 is a rear pillar, 15 is a rear bumper, and 16 is a rear wheel.

  FIG. 2 is a plan view of the rear part of the vehicle body according to the present invention. A vehicle body 20 (vehicle body frame 20) in the vehicle 10 has left and right side sills 21 and 21 extended forward and backward at the center of the vehicle body, and left and right rear side frames 30 and 30 extended forward and backward at the rear of the vehicle body. The left and right frame extensions 40, 40 extend rearward from the rear ends 32, 32, and cross members 51, 52 are spanned between the front end portions and the rear end portions of the left and right rear side frames 30, 30, respectively.

  In this way, the left and right rear side frames 30, 30 are extended rearward from the rear ends of the left and right side sills 21,21. As shown in FIG. 2, the vehicle body 20 is symmetrical with respect to the vehicle width center line CL. Hereinafter, the configuration of the left side of the vehicle body 20 will be mainly described, and the configuration of the right side is the same as the configuration of the left, and thus the description thereof is omitted.

  The rear side frame 30 and the frame extension 40 generally have an upper open U-shaped cross section (in other words, an upper open U-shaped cross section, an upper open hat-shaped cross section, and a square bowl shape). This rear side frame 30 is a press-molded product of a thick steel plate (plate thickness t1) having flanges 31, 31 at both open ends. The frame extension 40 is a press-formed product of a thin steel plate (plate thickness t2) having flanges 41 and 41 at both open ends.

t1> t2. Moreover, the cross section of the junction part of the rear side frame 30 and the frame extension part 40 is a substantially identical shape and the same dimension member. Therefore, the frame extension 40 is a low-strength (low-strength) member, that is, a fragile member with respect to the rear side frame 30.
In order to make the frame extension 40 fragile with respect to the rear side frame 30, for example, the material of the rear side frame 30 and the material of the frame extension 40 are used in addition to the configuration in which the plate thickness is changed as described above. This can also be achieved by changing the strength of each material itself.
The rear side frame 30 has high strength to protect various members such as a fuel tank and a fuel pipe disposed at the rear of the vehicle body.

FIG. 3 is a cross-sectional view of the rear portion of the vehicle body according to the present invention as seen from the left side, showing the relationship of the rear end panel 60 with respect to the left rear side frame 30 and the frame extension 40, and a floor panel 53 stretched on the upper surface of the vehicle body 20. It shows that.
FIG. 4 is an exploded view of the rear part of the vehicle body according to the present invention, showing the relationship of the rear end panel 60 to the left rear side frame 30 and the frame extension 40.

  As shown in FIGS. 3 and 4, the rear end panel 60 forming a part of the rear surface 11 of the vehicle body is a press-formed product of a vertical plate-shaped steel plate. The upper end of the rear side (left side in the figure) of the rear end panel 60 is reinforced by a reinforcing member 70 having a U-shaped cross section extending in the vehicle width direction. For this reason, the upper end portion 61 of the rear end panel 60 has a closed cross section having a rectangular shape in cross section. The upper end 61 of the rear end panel 60 is higher than the frame extension 40.

  The vehicle body 20 is integrally provided with a fragile left frame extension 40 extending rearward at the rear end 32 of the left rear side frame 30, and the frame extension 40 is located behind the rear end panel 60 that forms the vehicle rear surface 11. The joining member 80 is extended from the middle of the length of the left frame extension 40 in a direction substantially perpendicular to the longitudinal direction, and the rear end panel 60 is joined to these joining members 80.

More specifically, the frame extension 40 extends rearward while maintaining a substantially continuous outer shape with the rear side frame 30. That is, the frame extension portion 40 is extended rearward while the outer shape line (ridge line) 42 of the frame extension portion 40 is generally continuous with the outer shape line (ridge line) 33 of the rear side frame 30 in the longitudinal direction of the vehicle body.
The frame extension 40 can be integrally provided on the rear side frame 30 by superimposing the front end 43 of the frame extension 40 on the rear end 32 of the rear side frame 30 and joining them by spot welding or the like.

  In this way, the frame extension 40 that is weaker than the rear side frame 30 is integrally provided at the rear end 32 of the rear side frame 30, so that the number of parts can be reduced and the configuration can be simplified. For this reason, the cost of the vehicle body 20 can be reduced.

The joining member 80 is a vertical plate-shaped bulkhead (partition plate) that divides the middle part of the frame extension 40 in the front-rear direction. The joining member 80 extends substantially vertically toward the upper end 61 of the rear end panel 60, and extends to the tip 81. The rear end panel 60 and the reinforcing member 70 are overlapped on the front and back, and are integrally joined by spot welding or the like.
Such a joining member 80 is fitted into the groove 44 of the frame extension 40 having a square bowl-shaped cross section, and is joined to the frame extension 40 by joining the bottom surface and the left and right side surfaces by spot welding or the like. I tried to install it.

  The relationship between the rear side frame 30, the frame extension 40, and the rear end panel 60 and the joining configuration described above are the same on the left and right.

  With such a configuration, the left and right ends of the rear end panel 60 can be integrally and firmly joined to each other in the middle of the length of the left and right frame extensions 40 and 40. For this reason, it is possible to sufficiently secure the joining strength and joining rigidity of the rear end panel 60 to the rear side frames 30 and 30 and the frame extensions 40 and 40 without providing a reinforcing member made of a separate member.

The distance from the rear end 32 of the rear side frame 30 to the rear end 45 of the frame extension 40, that is, the total length of the frame extension 40 is L1.
The distance from the rear end 32 of the rear side frame 30 to the joining member 80, that is, the amount of extension of the front end 43 of the frame extension 40 forward from the rear end panel 60 is L2, which is shorter than the total length L1 of the frame extension 40 ( L1> L2). The position of the rear end 32 of the rear side frame 30 is set to the front as much as the front end 43 of the frame extension 40 extends forward.
The distance from the attachment position of the joining member 80 to the rear end 45 of the frame extension 40, that is, the protrusion amount by which the frame extension 40 protrudes rearward from the rear end panel 60 is L3. L3 has a relationship of L3 = L1-L2.

  As shown in FIG. 3, the frame extension portion 40 has a closed cross-sectional structure by closing the upper surface of the portion protruding rearward from the rear end panel 60 with a plate material 91 indicated by an imaginary line. it can. In this way, the absorption performance of the collision energy En acting on the rear end 45 of the frame extension 40 from behind can be changed.

Next, the operation of the rear structure of the vehicle body 20 having the above configuration will be described with reference to FIGS.
As shown in FIGS. 2 and 3, the left and right frame extensions 40, 40 extending rearward from the rear ends 32, 32 of the left and right rear side frames 30, 30 are extended to the rear of the rear end panel 60 on the rear surface of the vehicle body. The frame extensions 40 can be provided continuously in front of and behind the rear end panel 60. As a result, the length (full length L1) of the frame extension portions 40, 40 can be set larger.

  When the collision energy En acts on the rear ends 45, 45 of the frame extending portions 40, 40 from the rear, the frame extending portions 40, 40 are crushed and plastically deformed over the entire length L1, and absorb the collision energy En. The absorption performance of the collision energy En acting from the rear of the vehicle body 20 can be further enhanced by the length of the frame extensions 40, 40 that are more fragile than the rear side frames 30, 30 in the front-rear direction (that is, the extension amount L2). it can.

  In addition, since the size L3 of the frame extensions 40, 40 projecting rearward from the rear end panel 60 can be controlled (set as appropriate), the degree of freedom in designing the vehicle body 20 can be increased.

  Furthermore, the rear side frame is configured such that the left and right frame extensions 40, 40 extend rearward while maintaining a substantially continuous outer shape with the left and right rear side frames 30, 30 (that is, while maintaining generally continuous ridge lines 33, 42). 30 and 30 are integrally provided at the rear ends 32 and 32, so that the collision energy En from the rear can be transmitted from the frame extensions 40 and 40 to the rear side frames 30 and 30 very efficiently.

FIG. 5 is an operational view of the rear part of the vehicle body according to the present invention.
Since the joining members 80 and 80 are extended from the middle of the longitudinal direction of the left and right frame extending portions 40 and 40 in a direction substantially perpendicular to the longitudinal direction, and the rear end panel 60 is joined to these joining members 80 and 80, reinforcement consisting of separate members Without providing any members, the joining rigidity of the rear end panel 60 to the rear side frames 30 and 30 and the frame extensions 40 and 40 can be sufficiently secured.

  Therefore, for example, the torsional load acting on the vehicle body 20 when the vehicle 10 travels on a rough road, the rolling moment (the moment M acting around the longitudinal axis passing through the center of gravity of the vehicle 10), etc. Even when the vehicle body 20 is twisted around the direction axis, the rigidity of the vehicle body 20 can be sufficiently ensured.

  In the present invention, the shapes, dimensions, and materials of the left and right rear side frames 30, 30, the frame extensions 40, 40, and the rear end panel 60 shown in the embodiment can be arbitrarily set.

  The rear structure of the vehicle body of the present invention is particularly suitable for an automobile that requires more amount of absorbed collision energy from the rear, that is, a crash stroke at the time of rear collision.

It is a perspective view of the rear part of the vehicle concerning the present invention. It is a top view of the rear part of the vehicle body concerning the present invention. It is sectional drawing which looked at the rear part of the vehicle body concerning this invention from the left side. It is an exploded view of the rear part of the vehicle body concerning the present invention. It is an effect | action figure of the rear part of the vehicle body which concerns on this invention. It is a schematic diagram of the rear part structure of the conventional vehicle body.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 20 ... Car body (body frame), 30 ... Rear side frame, 32 ... Rear end of rear side frame, 40 ... Frame extension part, 45 ... Rear end of frame extension part, 60 ... Rear end panel, 80 ... Joining member, En ... Collision energy.

Claims (1)

And if extended around the left and right rear side frames at the rear portion of the vehicle body,
The rear end of these rear side frames extending rearwardly while maintaining a generally continuous contour with the rear side frames, provided the frame extension of the low intensity consisting shaped cross section of the upper opening co integrally,
In the frame extension, a longitudinal plate-shaped bulkhead that partitions the middle in the longitudinal direction in a substantially perpendicular direction is provided by bonding and fixing at the bottom surface and the left and right side surfaces,
The frame extension is extended to the rear of the rear end panel constituting the rear surface of the vehicle body ,
The rear end panel is reinforced with a reinforcing member on the back side, and the lower end of the rear end panel reinforced with a reinforcing member is joined to the upper end of the bulkhead.
The rear structure of the vehicle body characterized by that .

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