JP3812207B2 - Rear floor structure of automobile - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rear floor structure of an automobile, and provides a rear floor structure of an automobile that can improve the sound vibration performance by increasing the mounting rigidity of a bracket that supports a muffler.
[0002]
[Prior art]
Rear side members extending in the front-rear direction are attached to both sides of the rear floor of the conventional vehicle body in the vehicle width direction from below. The rear side member is a strength member formed of a thicker plate than the rear floor, and the rear side member provides the overall rigidity of the rear portion of the vehicle body. A spare tire pan is recessed in the center of the rear floor in the vehicle width direction, and the spare tire is stored in the spare tire pan. A rear panel is coupled to the rear end of the rear floor, and a rear wall of the vehicle body is formed by the rear panel.
[0003]
A muffler is supported at a lower part of the rear floor via a bracket (see Japanese Utility Model Laid-Open No. 2-121386 as a similar technique). Two mufflers may be provided on both sides in the vehicle width direction, or only one muffler may be provided on one side. In either case, the bracket is coupled to the corners of the rear floor and the rear panel to form a closed cross section. A support member for supporting the muffler is attached to the bracket. In general, this type of bracket is formed in a size that is small enough to mount a muffler support member, and is attached to a position near the spare tire pan.
[0004]
[Problems to be solved by the invention]
However, in such a conventional technique, since the bracket for supporting the muffler is attached to the rear floor and the rear panel formed of thin plates, the mounting rigidity of the bracket is temporarily formed although a closed cross section is formed. However, the support rigidity of the muffler may be reduced. When the support rigidity of the muffler is lowered, the sound vibration performance is lowered, and the vibration sound of the muffler may enter the vehicle interior. In order to increase the mounting rigidity of the bracket, increasing only the thickness of the bracket itself is not very effective, and it is necessary to increase the thickness of the rear floor or rear panel on the side where the bracket is attached. In particular, with the recent increase in engine output, the size of the muffler has also increased, and there is a background that is particularly required to improve the sound vibration performance of the muffler. At the expense of improving the sound vibration performance of the muffler.
[0005]
Further, since the size of the bracket itself is small enough to attach a muffler support member, even if such a small size bracket is attached to the rear floor and the rear panel, it does not contribute much to the improvement of the overall rigidity of the vehicle body.
[0006]
On the other hand, to the rear part of the vehicle body, a tow hook used for towing the vehicle body or fixing the shipping is attached. This tow hook is screwed onto a mounting portion set at the rear of the vehicle body. Since a large load is applied to the pulling hook, the setting position of the mounting portion is limited to the rear end portion of the rear side member that is a strength member. The rear bumper corresponding to the attaching portion of the tow hook is provided with an openable / closable opening for inserting the tow hook. Since the position of the opening is determined according to the position of the traction hook, the position cannot be freely set in the rear bumper, and the degree of freedom of modeling of the rear bumper is lowered.
[0007]
Therefore, the present invention can increase the mounting rigidity of the bracket that supports the muffler to improve the sound vibration performance and the like, increase the degree of freedom of the setting position of the tow hook mounting portion, and increase the degree of freedom of modeling of the rear bumper. It is an object to provide a rear floor structure of an automobile that can be improved.
[0008]
[Means for Solving the Problems]
According to the first aspect of the present invention, a rear side member extending in the front-rear direction is attached to both sides of the rear floor in the vehicle width direction from the lower side, and a spare tire pan is recessed substantially at the center in the vehicle width direction. The rear panel forming the rear wall of the vehicle body is coupled to the rear floor and the rear floor structure of the automobile in which a bracket is coupled to the corner of the rear panel to form a closed cross section, and a muffler support member is attached to the bracket. At least an outer end portion in the vehicle width direction of the bracket is coupled to a side surface portion of the rear side member.
[0009]
Moreover , the vehicle width direction inner side edge part of the bracket is couple | bonded with the side part of the spare tire pan.
[0010]
In addition , the mounting portion of the tow hook was set on the bracket.
[0011]
Further , the vertical position of the lower surface portion of the bracket coincides with the lower surface portion of the rear side member.
[0012]
In addition , brackets are provided on both sides of the spare tire pan in the vehicle width direction, and a rearward embossed portion for connecting the two brackets in the vehicle width direction is formed on the rear panel.
[0013]
Moreover , the cross section of the vehicle width direction both ends in an embossing part becomes small gradually toward the vehicle width direction outer side.
[0014]
Further , the upper and lower positions of the upper surface portion and the lower surface portion of the embossed portion match the rear floor and the lower surface portion of the bracket, respectively.
[0015]
【The invention's effect】
In the invention according to claim 1, since at least the vehicle width direction outer side end portion of the bracket is coupled to the side surface portion of the rear side member which is a strength member, a closed cross section along the vehicle width direction formed by the bracket, The closed cross section formed by the rear side member along the front-rear direction is coupled, so that the mounting rigidity of the bracket is increased and the sound vibration performance of the muffler is improved.
[0016]
In addition , because the inner end of the bracket in the vehicle width direction is joined to the side surface of the spare tire pan, both ends of the bracket in the vehicle width direction are fixed, further improving the mounting rigidity of the bracket. To do. Furthermore , since the size of the bracket in the vehicle width direction is increased, the overall rigidity of the vehicle body is increased accordingly.
[0017]
Further , since the mounting rigidity of the bracket is increased, this bracket is used as a strength member for setting the mounting portion of the traction hook. And since this bracket is a closed cross section along a vehicle width direction, compared with the past, the setting position of the attachment part of a tow hook can be selected more freely in a vehicle width direction. Therefore, if the mounting portion of the tow hook is in a position convenient in terms of design and formability when the opening is formed in the rear bumper in the vehicle width direction of the bracket, the degree of freedom of modeling of the rear bumper increases. The design and formability of the rear bumper are improved.
[0018]
In addition , since the vertical position of the lower surface portion of the bracket matches the lower surface portion of the rear side member, load transmission from the bracket to the rear side member is reliable, and the mounting rigidity of the bracket is further improved. Further , the rear side member can be prevented from rotating during a side collision, and the rear side member can be sufficiently crushed to reliably absorb the side collision energy.
[0019]
Further , since the two brackets provided on both sides in the vehicle width direction are connected by the embossed portion, both the mounting rigidity of the bracket and the rigidity of the rear panel are improved.
[0020]
Moreover , since the rigidity at both ends in the vehicle width direction of the embossed portion gradually changes, it is possible to prevent the rear panel from being bent from both ends of the embossed portion when a load is input.
[0021]
In addition , since the top and bottom positions of the top and bottom surfaces of the embossed part match the bottom surface of the rear floor and bracket, the load transmission from the embossed part to the rear floor and bracket is reliable, and the rigidity of the rear panel, rear floor, and bracket Both improve.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a view of the rear floor 1 of the vehicle body as viewed from above. Rear side members 2 extending in the front-rear direction are attached to both sides of the rear floor 1 in the vehicle width direction from below. The rear side member 2 is a strength member formed of a thicker plate than the rear floor 1 and has a cross-sectional inverted hat shape. By attaching the rear side member 2 to the rear floor 1, the overall rigidity of the rear portion of the vehicle body is obtained.
[0023]
A spare tire pan 3 is recessed in the center of the rear portion of the rear floor 1 in the vehicle width direction so that the spare tire 4 can be accommodated therein. A rear panel 5 is coupled to the rear end of the rear floor 1, and a rear wall of the vehicle body is formed by the rear panel 5. The rear panel 5 has a rearward embossed portion 6 formed along the vehicle width direction. The embossed portion 6 has a U-shaped cross section, and both end portions 7 are inclined so as to gradually converge to the general surface of the rear panel 5. Therefore, the both end portions 7 of the embossed portion 6 are gradually reduced in cross section in the vehicle width direction outer side.
[0024]
Between the spare tire pan 3 and the left and right rear side members 2, brackets 8 having a substantially L-shaped cross section are attached to the corners of the rear floor 1 and the rear panel 5. The bracket 8 has a size in the vehicle width direction from the spare tire pan 3 to the rear side member 2, and has flanges 8a, 8b, 8c, and 8d at both the upper and lower ends and the vehicle width direction both ends. The flange 8a at the upper end of the bracket 8 is joined to the rear floor 1, the flange 8b at the lower end is joined to the rear panel 5, and the flange 8c on the outer side in the vehicle width direction is joined to the side surface of the rear side member 2 to the inner side in the vehicle width direction. The flange 8d is joined to the side surface of the spare tire pan 3. Therefore, the bracket 8 forms a closed section box structure in which the four sides are closed.
[0025]
A concave section 9 having a curved cross section is formed upward at a position near the spare tire pan 3 on the lower surface portion of the bracket 8, and a rod 10 is welded thereto as a “support member”. And this rod 10 and the rod 12 by the side of the muffler 11 installed in the right and left sides are connected via the rubber insulator 13, and the rear part of the muffler 11 is elastically supported. The muffler 11 of this embodiment has a large size that enables high engine output.
[0026]
Further, a mounting portion 15 for the traction hook 14 is provided at a position closer to the rear side member 2 than the recess 9 in the bracket 8. The attachment portion 15 has a cylindrical shape having an internal thread portion inside, and is fixed to the lower surface portion of the bracket 8 by a fixing bracket 16 from above. The mounting portion 15 and the fixing bracket 16 are welded so that the mounting portion 15 does not rotate inside the fixing bracket 16. A hole 17 (see FIG. 3) having a diameter corresponding to the female screw portion is formed in a portion corresponding to the mounting portion 15 of the rear panel 5 to pull the vehicle body or to fix the vehicle body in the case of shipping or the like. The male screw portion of the pulling hook 14 is inserted through the hole 17 and can be screwed into the mounting portion 15.
[0027]
Next, the advantages of the automobile rear floor structure according to this embodiment will be described.
[0028]
In the bracket 8 of this embodiment, the flange 8c on the outer side in the vehicle width direction is coupled to the rear side member 2 that is a strength member, so that the mounting rigidity of the bracket 8 is increased. In particular, the flange 8d on the inner side in the vehicle width direction of the bracket 8 is also coupled to the side surface portion of the spare tire pan 3, so that both end portions of the bracket 8 in the vehicle width direction are fixed. The mounting rigidity of the bracket 8 is sufficiently improved. When the mounting rigidity of the bracket 8 is improved, the mounting rigidity of the rod 10 is increased. When the mounting rigidity of the rod 10 is increased, the support rigidity of the muffler 11 is improved, and finally the sound vibration performance of the muffler 11 is improved.
[0029]
Moreover, since the bracket 8 of this embodiment couple | bonds both ends with the spare tire pan 3 and the rear side member 2, the vehicle width direction size is larger than before. By connecting such a large-sized bracket 8 to the rear floor 1 or the like, the closed cross section along the vehicle width direction formed by the bracket 8 and the closed cross section along the front-rear direction formed by the rear side member 2 are combined. As a result, the overall rigidity of the rear portion of the vehicle body is increased, and the torsional rigidity of the vehicle body is improved.
[0030]
As described above, since the mounting rigidity of the bracket 8 is increased, there is no problem even if the mounting portion 15 of the traction hook 14 is set on the bracket 8, and the load applied to the mounting portion 15 from the traction hook 14 is reliably received by the bracket 8. .
[0031]
Moreover, since it is a closed cross section along the vehicle width direction of the bracket 8, the setting position of the attachment portion 15 of the tow hook 14 can be selected more freely in the vehicle width direction than in the past. Therefore, if the mounting portion 15 of the tow hook 14 is selected at a position convenient in terms of design and formability of the rear bumper (not shown) in the vehicle width direction of the bracket 8, the degree of freedom of modeling of the rear bumper is increased. The design and formability of the rear bumper are improved.
[0032]
Further, since the vertical position of the lower surface portion of the bracket 8 and the lower surface portion of the rear side member 2 are matched, the load transmission from the bracket 8 to the rear side member is reliable, and also in this respect, the mounting rigidity of the bracket 8 is high. improves. Further, it is possible to prevent the rear side member 2 from rotating at the time of a side collision, sufficiently crush the rear side member 2, and reliably absorb the side collision energy.
[0033]
And since the two brackets 8 provided on both sides in the vehicle width direction are connected by the embossed portions 6 formed on the rear panel 5, both the mounting rigidity of the bracket 8 and the rigidity of the rear panel 5 are improved. Moreover, since the rigidity at the both end portions 7 of the embossed portion 6 gradually changes, it is possible to prevent the rear panel 5 from being broken from the both end portions of the embossed portion 6 when a load is input.
[0034]
Further, as shown in FIG. 4, since the upper and lower positions of the upper surface portion and the lower surface portion of the embossed portion 6 match the lower surface portions of the rear floor 1 and the bracket 8, respectively, the embossed portion 6 extends to the rear floor 1 and the bracket 8. Load transmission is reliable, and the rigidity of the rear panel 5, the rear floor 1, and the bracket 8 is improved.
[0035]
In the above embodiment, the large muffler 11 is provided on both sides in the vehicle width direction. However, the muffler 11 may be provided only on one side or may be small. . In addition, when the rod 10 is welded to the side surface of the rear side member 2 separately from the rod 10 of the embodiment and the outside of the muffler 11 in the vehicle width direction is supported via the rod. Of course, the present invention is also applicable.
[Brief description of the drawings]
FIG. 1 is a plan view showing a rear floor structure of an automobile according to an embodiment of the present invention.
FIG. 2 is a perspective view of a rear floor structure viewed from the direction indicated by an arrow X in FIG.
3 is a cross-sectional view taken along the line SA-SA shown in FIG.
4 is a cross-sectional view taken along line SB-SB in FIG.
5 is a cross-sectional view taken along the line SC-SC shown in FIG.
[Explanation of symbols]
1 Rear Floor 2 Rear Side Member 3 Spare Tire Pan 5 Rear Panel 6 Embossed Section 8 Bracket 10 Rod (Support Member)
11 Muffler 14 Tow hook 15 Mounting part

Claims (1)

Rear side members extending in the front-rear direction on both sides of the rear floor in the vehicle width direction are attached from the lower side, and a spare tire pan is recessed in a substantially central portion in the vehicle width direction, and a rear panel that forms a vehicle body rear wall at the rear end of the rear floor A rear floor structure of an automobile in which a bracket is coupled to the corners of the rear floor and the rear panel to form a closed cross section, and a muffler support member is attached to the bracket;
Said bracket, respectively provided on both sides in the vehicle width direction of the spare tire pan is coupled to the side portion of the vehicle width direction outer end Ghali Ya side member of each bracket Rutotomoni, the inward end the spare tire Joined to the side of the bread,
At least one of the brackets is provided with a traction hook mounting portion,
The vertical position of the lower surface portion of the bracket matches the lower surface portion of the rear side member,
A rear-facing embossed portion for connecting the two brackets to the rear panel in the vehicle width direction is formed, and cross sections of both end portions in the vehicle width direction of the embossed portion are gradually reduced outward in the vehicle width direction, and A rear floor structure for an automobile, wherein upper and lower positions of an upper surface portion and a lower surface portion of the embossed portion respectively coincide with the rear floor and the lower surface portion of the bracket .

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