JP5857592B2 - Car body rear structure - Google Patents

Description

  The present invention relates to a vehicle body rear structure provided with a battery mounted on a vehicle body rear portion.

  In recent years, hybrid vehicles having a battery mounted at the rear of the vehicle body are known. A hybrid vehicle generally has a smaller fuel tank than a gasoline vehicle (for example, Patent Document 1). For this reason, in the hybrid vehicle, the structure for fixing the fuel tank to the vehicle body is different from the gasoline vehicle.

  In a gasoline vehicle, for example, a fuel tank is fixed to a vehicle body using a pair of side members extending in the vehicle front-rear direction and a front and rear cross members passed between the pair of side members.

  Patent Document 1 discloses a vehicle body structure of a hybrid vehicle in which a step portion protruding upward is formed on a floor panel, and a battery and a fuel tank are fixed along a vehicle width direction in a space formed by the step portion. Have been described.

JP 2001-138754 A

  However, the vehicle body structure described in Patent Document 1 is merely to shorten the length of the hybrid vehicle in the vehicle front-rear direction by fixing the battery and the fuel tank along the vehicle width direction. There is no mention of protecting the fuel tank in the event of a collision (rear collision).

  In the vehicle body structure described above, when an impact due to a rear collision is received, a portion for fixing the fuel tank to the vehicle body may be deformed and the fuel tank may not be protected.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a vehicle body rear structure that can protect a fuel tank at the time of a rear collision.

  In order to solve the above problems, a typical configuration of a vehicle body rear structure according to the present invention is a pair of vehicles arranged along a side edge of a rear floor panel that forms a floor surface of a vehicle body rear portion of a hybrid vehicle and extending in the vehicle longitudinal direction. Vehicle body rear structure comprising a side member and a battery disposed between the pair of side members, a frame-shaped frame member that surrounds the entire periphery of the battery and supports the battery, and a pair of frames in front of the frame member The first cross member passed between the side members, the second cross member passed between the pair of side members in front of the first cross member, and the first cross member and the second cross member near the center of the vehicle body And a fuel tank mounted between the bridge member and one of the pair of side members. One of the first mounting portion projecting forward toward the second cross member and fixed to the second cross member, and the second mounting portion projecting laterally toward the bridge member and fixed to the bridge member. And a third attachment portion that projects laterally toward the side member and is fixed to the side member.

  According to the above configuration, the fuel tank is not fixed across the region including the rear floor panel located in front of the first cross member disposed behind the fuel tank and in front of the frame member. The fuel tank has the vehicle outer side fixed to the side member, the vehicle body center side fixed to the bridge member, and the vehicle body front side fixed to the second cross member. Here, the region including the first cross member and the rear floor panel disposed in front of the frame member having high rigidity is a region (low rigidity region) having relatively lower rigidity than the frame member. For this reason, in this vehicle body rear part structure, the low rigidity area | region containing a 1st cross member deform | transforms in response to the collision (rear collision) from the vehicle rear, and can fully absorb the impact accompanying a rear collision. At this time, with the deformation of the low-rigidity region, there is a possibility that the mounting seat surface or the highly rigid frame member enters forward. Even in such a case, since the fuel tank is not fixed to the first cross member as described above, it does not come into contact with the mounting seat surface or the entering frame member. Therefore, the fuel tank can be protected at the time of a rear collision.

  The second cross member has a first mounting seat surface for fixing the first mounting portion, the bridge member has a second mounting seat surface for fixing the second mounting portion, and the side member has a third mounting portion. And has a third mounting seat surface that is substantially the same height as the first mounting seat surface, and the second mounting seat surface is erected downward from the bridge member. The height of the surface and the third mounting seat surface is preferably substantially the same. As a result, the fuel tank can be stably fixed to the rear portion of the vehicle body.

  The vehicle body rear structure may further include an electrical component mounted between the bridge member and the other one of the pair of side members. In this case, a bridge member may be used to fix the electrical component, and the fuel tank and the electrical component can be installed along the vehicle width direction, thereby saving space.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle body rear part structure which can protect a fuel tank at the time of a rear collision can be provided.

It is a figure which shows a part of vehicle to which the vehicle body rear part structure in this embodiment is applied. It is a bottom view of the vehicle body rear part structure of FIG. It is the perspective view which looked at a part of vehicle body rear part structure of FIG. 2 from diagonally downward. FIG. 4 is a perspective view showing a state in which a fuel tank is mounted on the rear body structure of FIG. 3. It is a perspective view which shows the vehicle body rear part structure of a comparative example. FIG. 3 is a schematic diagram illustrating a state of a rear collision of the vehicle body rear portion structure of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram illustrating a part of a vehicle 110 to which a vehicle body rear structure 100 according to this embodiment is applied. In FIG. 1, the vehicle body rear structure 100 is shown with each member omitted as appropriate. For example, the tire 112 shown in the figure is installed on the right side of the vehicle (the back side in FIG. 1), and the tire on the left side of the vehicle (the front side in FIG. 1) is omitted. In the figure, the arrow Fr indicates the front side of the vehicle, and the arrow Rh indicates the right side of the vehicle.

  The vehicle 110 is a hybrid vehicle, and includes a battery 114 mounted on the rear part of the vehicle body and a fuel tank 116 mounted on the front side of the vehicle with respect to the battery 114, as shown in FIG.

  FIG. 2 is a bottom view of the vehicle body rear structure 100 of FIG. FIG. 3 is a perspective view of a part of the vehicle body rear structure 100 of FIG. 2 as viewed obliquely from below. Here, FIG. 3 shows a state in which the fuel tank 116 is removed from the vehicle body rear structure 100. 4 is a perspective view showing a state in which the fuel tank 116 is mounted on the vehicle body rear structure 100 of FIG.

  In the vehicle body rear structure 100, as shown in FIG. 2, a fuel tank 116 and an electrical component 118 such as a DC-DC converter are installed side by side along the vehicle width direction. In FIG. 2, only a part of the battery 114 located on the vehicle rear side of the fuel tank 116 is shown. The battery 114 is surrounded and supported by a frame-shaped frame member 120 that shows only a part.

  The vehicle body rear structure 100 includes, for example, a rear floor panel 122 that forms a floor surface of the vehicle body rear portion shown in FIG. 3, a pair of side members 124 and 126, a first cross member 128, and a second cross member 130 shown in FIG. 2. And a bridge member 132. The pair of side members 124 and 126 are members extending in the vehicle front-rear direction, and are disposed on the side ends of the rear floor panel 122.

  The first cross member 128 is a member that is interposed between the pair of side members 124 and 126 in front of the frame member 120 and has lower rigidity than the frame member 120. Note that the region including the rear floor panel 122 positioned in front of the first cross member 128 has lower rigidity. The first cross member 128 is formed with fixing portions 128 a and 128 b extending toward the frame member 120. The frame member 120 is fixed to the fixing portions 128a and 128b of the first cross member 128 by bolts or the like, for example.

  Here, “lower in rigidity” than the frame member 120 has a relative meaning compared to the frame member 120. That is, when the frame member 120 receives an impact load due to a rear collision or the like, a region including the first cross member 128 in the traveling direction of the load and the rear floor panel 122 positioned in front of the first cross member 128 This means that the frame member 120 does not deform while preferentially deforming (breaking) and absorbing an impact.

  The second cross member 130 is a member passed between the pair of side members 124 and 126 in front of the first cross member 128, and has first mounting seat surfaces 130a and 130b as shown in FIG. . The bridge member 132 is a member that is passed between the first cross member 128 and the second cross member 130 in the vicinity of the center of the vehicle body as shown in FIG. 2, and has a second mounting seat as shown in FIG. A surface 132a is provided. Further, the side member 124 has a third mounting seat surface 124a as shown in FIG.

  The second mounting seat surface 132a is erected downward from the bridge member 132, and has substantially the same height as the first mounting seat surfaces 130a and 130b and the third mounting seat surface 124a.

  As shown in FIG. 2, the fuel tank 116 is mounted between the bridge member 132 and the side member 124. The electrical component 118 is mounted between the bridge member 132 and the side member 126.

  As shown in FIG. 2, the fuel tank 116 includes a flange 140 that extends outward in a plan view, and first mounting portions 140 a and 140 b, a second mounting portion 140 c, and a third mounting portion that partially extend the flange 140 outward. 140d.

  As shown in FIG. 2, the first mounting portions 140 a and 140 b project forward toward the second cross member 130 and are fixed to the first mounting seat surfaces 130 a and 130 b of the second cross member 130, respectively. As shown in FIGS. 2 and 4, the second mounting portion 140 c projects laterally toward the bridge member 132 and is fixed to the second mounting seat surface 132 a of the bridge member 132.

  As shown in FIGS. 2 and 4, the third attachment portion 140 d protrudes laterally toward the side member 124 and is fixed to the third attachment seat surface 124 a of the side member 124. In addition, each attachment part 140a, 140b, 140c, 140d and each attachment seat surface 130a, 130b, 132a, 124a are fixed using the screw 142 etc., as shown in FIG.

  As described above, the fuel tank 116 is fixed to the second cross member 130 on the front side of the vehicle body, fixed to the bridge member 132 on the center side of the vehicle body, and further fixed to the side member 124 on the outer side of the vehicle. That is, the fuel tank 116 is not fixed across the region including the rear floor panel 122 positioned in front of the first cross member 128 disposed behind the fuel tank 116 and in front of the frame member 120.

  FIG. 5 is a perspective view showing a vehicle body rear structure 100A of a comparative example. In the figure, the same members as those shown in the vehicle body rear structure 100 of the above embodiment are given the same reference numerals, and description thereof will be omitted as appropriate.

  The vehicle body rear structure 100A is provided with mounting seat surfaces 144a and 144b on the first cross member 128 in place of the second mounting seat surface 132a of the bridge member 132 and the third mounting seat surface 124a of the side member 124. , Different from the vehicle body rear structure 100.

  Here, the first cross member 128 and the rear floor panel 122 have lower rigidity than the frame member 120. For this reason, the region including the first cross member 128 and the rear floor panel 122 disposed in front of the frame member 120 is a region (low rigidity region) having relatively lower rigidity than the frame member 120.

  Therefore, in the vehicle body rear structure 100A of the comparative example, the mounting seat surfaces 144a and 144b of the first cross member 128 come into contact with the main body of the fuel tank 116 when the low-rigidity region is deformed during a collision (rear collision) from the rear of the vehicle. Alternatively, there is a possibility that the frame member 120 having high rigidity comes into contact with the main body of the fuel tank 116. For this reason, in the vehicle body rear structure 100A, it is difficult to protect the fuel tank 116 at the time of a rear collision.

  Hereinafter, the state of the vehicle body rear part structure 100 at the time of a rear collision will be described with reference to FIG. FIG. 6 is a schematic diagram showing a state at the time of a rear collision of the vehicle body rear portion structure 100 of FIG. FIG. 6A shows a state before the rear impact, and FIG. 6B shows a state before the rear impact. In the drawing, the rear body structure 100 of the vehicle body is schematically shown as viewed from below. For example, the opening 122a of the frame member 120 and the rear floor panel 122 is indicated by a simple rectangle. Further, in the drawing, the battery 114 and the electrical component 118 are omitted. Although not shown, the battery 114 is mounted on the rear of the vehicle body by the frame member 120 in a state of straddling the opening 122a of the rear floor panel 122.

  In the vehicle body rear structure 100, as shown in FIG. 6A, the vehicle front side of the frame-shaped frame member 120 is fixed to the fixing portions 128a and 128b of the first cross member 128 that is lower in rigidity than the frame member 120. Yes. Further, the first cross member 128 and the rear floor panel 122 disposed in front of the frame member 120 are in a low rigidity region as described above.

  On the other hand, as described above, the fuel tank 116 is not fixed to the low-stiffness first cross member 128, the vehicle body front side is fixed to the second cross member 130, and the vehicle body center side is fixed to the bridge member 132. Further, the outside of the vehicle is fixed to the side member 124.

  In the vehicle body rear structure 100, when an impact associated with a rear collision indicated by a hollow arrow in FIG. 6B is received, for example, as illustrated, the low rigidity region including the first cross member 128 and the rear floor panel 122 is deformed, The impact associated with the rear impact is fully absorbed.

  On the other hand, since the fuel tank 116 is not fixed to the first cross member 128, even if the first cross member 128 is deformed as shown in the figure, the fuel tank 116 is not attached to the first cross member 128 or the highly rigid frame member 120. There is no contact. Note that if the fuel tank 116 and the first cross member 128 are arranged so that their positions are shifted in the height direction, contact between the fuel tank 116 and the first cross member 128 is easily avoided.

  The vehicle body rear structure 100 according to the present embodiment has a configuration in which a low-rigidity region is formed on the front side of the vehicle with respect to the frame member 120 and sufficiently absorbs an impact caused by a rear collision. Even if it is deformed, the fuel tank 116 is not easily affected by the rear impact. Therefore, the fuel tank 116 can be protected at the time of a rear collision.

  Further, the height of the second mounting seat surface 132a erected from the bridge member 132 is substantially the same as the heights of the other first mounting seat surfaces 130a, 130b and the third mounting seat surface 124a. Can be fixed stably.

  Furthermore, although the electrical component 118 is mounted between the bridge member 132 and the side member 126, in this case, the electrical component 118 may be fixed using the bridge member 132, for example. In this way, the fuel tank 116 and the electrical component 118 can be easily installed along the vehicle width direction, and space can be saved.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be used for a vehicle body rear structure including a battery mounted on the vehicle body rear portion.

DESCRIPTION OF SYMBOLS 100 ... Car body rear structure, 110 ... Vehicle, 112 ... Tire, 114 ... Battery, 116 ... Fuel tank, 118 ... Electrical component, 120 ... Frame member, 122 ... Rear floor panel, 122a ... Opening part, 124, 126 ... Side member, 124a ... third mounting seat surface, 128 ... first cross member, 128a, 128b ... fixed portion, 130 ... second cross member, 130a, 130b ... first mounting seat surface, 132 ... bridge member, 132a ... second mounting seat Surface 140, Flange 140a, 140b First mounting portion 140c Second mounting portion 140d Third mounting portion 142 Screw

Claims (3)

A pair of side members arranged along the side edges of the rear floor panel forming the floor surface of the rear part of the vehicle body of the hybrid vehicle and extending in the vehicle longitudinal direction;
In a vehicle body rear structure including a battery disposed between the pair of side members,
A frame-like frame member that surrounds the entire periphery of the battery and supports the battery;
A first cross member passed between the pair of side members in front of the frame member;
A second cross member passed between the pair of side members in front of the first cross member;
A bridge member passed between the first cross member and the second cross member near the center of the vehicle body;
A fuel tank mounted between the bridge member and one of the pair of side members;
The first cross member and the rear floor panel are less rigid than the frame member,
The fuel tank is not fixed to or in contact with the first cross member, projects forward toward the second cross member, and is fixed to the second cross member; and the bridge member. A second mounting portion projecting laterally toward the side and fixed to the bridge member; and a third mounting portion projecting laterally toward the one of the side members and secured to the side member. Car body rear structure. The second cross member has a first mounting seat surface for fixing the first mounting portion,
The bridge member has a second mounting seat surface that fixes the second mounting portion;
The side member has a third mounting seat surface that fixes the third mounting portion and has substantially the same height as the first mounting seat surface,
The second mounting seat surface is erected downward from the bridge member, and is substantially the same height as the first mounting seat surface and the third mounting seat surface. The vehicle body rear structure according to 1.   The vehicle body rear structure according to claim 1, wherein the vehicle body rear structure further includes an electrical component mounted between the bridge member and the other one of the pair of side members.

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