JP5454312B2 - Lower structure at the rear of the car body - Google Patents

Description

  The present invention relates to a lower structure of a rear part of a vehicle body that is configured to be able to attach a component arranged at the rear part of the vehicle body.

  When the vehicle travels, a load may be applied to parts arranged at the rear of the vehicle body due to vertical and horizontal movements caused by acceleration, deceleration, turning, gaps, etc. of the vehicle. Due to this load, the rear part of the vehicle body may vibrate mainly in the vertical direction. In particular, a large part such as a muffler is subjected to a large load due to its large weight. When the load is large, there is a risk that the rear part of the vehicle body is impacted. In particular, since a larger load is applied to a large part such as a muffler as described above due to its large weight, there is a risk of receiving a larger impact. When stress concentrates on the support structure of the component due to such an impact, the support structure of the component is deformed, and interference between the components may occur, and problems such as chatter noise may occur.

  On the other hand, the muffler may vibrate greatly in a low frequency region when the vehicle is traveling. In addition, since a gas flow wave is generated inside the muffler and the exhaust pipe provided in the muffler, this gas flow wave causes the muffler to vibrate greatly in the vertical and vehicle width directions in the middle and high frequency regions. There is. Such noise generated by the vibration of the components easily propagates into the passenger compartment and is not preferable.

  Therefore, in general, the rear part of the vehicle body is supported by a member having high rigidity. In particular, the muffler is generally supported by a rear side member having high rigidity by being composed of a thick plate. As a support structure using such a rear side member, for example, in the lower structure of the rear part of the vehicle body disclosed in Patent Document 1, an exhaust pipe extending from the rear part of the muffler toward the rear of the vehicle is used as a suspension bracket in order to support the muffler. The suspension fitting is suspended by a hook member welded to a vehicle body frame such as a rear side frame located above the exhaust pipe via a ring-shaped hanger rubber.

  Further, in the lower structure of the rear part of the vehicle body disclosed in Patent Document 2, in order to support the muffler, a support member extending from the rear part of the muffler toward the rear of the vehicle is provided, and is formed to be recessed downward on the rear side frame and the rear floor. A mounting bracket extending in the vehicle width direction is provided with the spare tire house. The support member is welded to the lower surface of the mounting bracket, the upper end of the mounting bracket is welded to the rear floor, the rear end of the mounting bracket is welded to the back panel, and both ends of the mounting bracket in the vehicle width direction are rear side frames. And welded to spare tire house.

Japanese Utility Model Publication No. 7-15404 JP 2000-255456 A

  However, in the lower structure of the rear part of the vehicle body of Patent Document 1, it is necessary to arrange the support structure of the muffler in the vicinity of the vehicle body frame, so that the degree of freedom in layout regarding the attachment of the muffler is lowered.

  Moreover, in the lower structure of the rear part of the vehicle body of Patent Document 2, it is necessary to weld a mounting bracket for mounting a muffler to many members such as a rear floor, a back panel, a rear side frame, and a spare tire house. Becomes complicated. In addition, the mounting bracket is a large part extending between the spare tire house and the rear side frame, which increases the vehicle weight and causes a problem.

  Therefore, in consideration of the layout flexibility especially related to the above-mentioned component mounting, when trying to mainly support such rear body components by a panel member such as a back panel that extends long in the vehicle width direction, Since the rigidity of the panel is low, when a load is applied to the part, the back panel vibrates greatly with the part and a large noise is generated. Further, the back panel is easily deformed when subjected to an impact. There was a problem. For this reason, in the conventional structure of the rear part of the vehicle body, a configuration in which the components of the rear part of the vehicle body are mainly supported by the back panel has not been adopted.

  The present invention has been made in view of such a situation, and its purpose is to increase the degree of freedom in layout related to the mounting of components at the rear of the vehicle body, mainly by the support structure using the panel member, and to mount the components. It is an object of the present invention to provide a lower structure of a rear part of a vehicle body that can reduce the vehicle weight, prevent generation of vibrations and noises, and can support parts by a highly rigid structure.

  In order to solve the problem, in the lower structure of the rear part of the vehicle body of the present invention, the rear edge of the rear floor of the vehicle is bent and formed in a hat shape so that the center in the vehicle width direction protrudes downward. A vertically extending joining flange is provided, a back panel extending in the vehicle width direction is provided, and the rear floor joining flange and the back panel are arranged in an overlapping manner so that components placed at the rear of the vehicle body can be attached. Has been. In the lower structure of the rear part of the vehicle body, the center in the vehicle width direction of the lower edge of the back panel is formed to project downward so as to have a curved part corresponding to the bent part of the rear edge of the rear floor. A mounting bracket is disposed on the back surface of the back panel and is overlapped and joined at an overlapping portion of the joining flange provided on the bent portion of the rear floor and the curved portion of the back panel.

  In the lower structure of the rear portion of the vehicle body according to the present invention, the mounting bracket and the back panel are respectively provided at the overlapping portions disposed on both sides with respect to the normal line of the curved portion of the back panel passing over the mounting bracket. And the rear floor are overlapped and joined.

  In the lower structure of the rear part of the vehicle body of the present invention, the part is a muffler for a vehicle, and a muffler hanger assembly that supports the muffler for the vehicle is configured and a part of a stay that is attached to the mounting bracket is in the normal line. It is formed to extend along.

  In the lower structure of the rear part of the vehicle body according to the present invention, a bead extending along the normal from a part of the stay arranged on the back panel is formed on the back panel.

According to the present invention, the following effects can be obtained.
In the lower structure of the rear part of the vehicle body of the present invention, the rear edge of the rear floor of the vehicle is bent in a hat shape so that the center in the vehicle width direction protrudes downward, and the joining flange extends in the vertical direction to the rear edge of the rear floor. A back panel extending in the vehicle width direction is provided, and the rear floor joining flange and the back panel are arranged so as to overlap each other, so that components arranged at the rear of the vehicle body can be attached. In the lower structure of the rear part of the vehicle body, the center in the vehicle width direction of the lower edge of the back panel is formed to project downward so as to have a curved part corresponding to the bent part of the rear edge of the rear floor. Three mounting brackets are arranged on the back surface of the back panel, and three of the mounting brackets are joined to each other at the overlapping portion of the joining flange provided on the bent portion of the rear floor and the curved portion of the back panel.
For this reason, three mounting brackets for mounting the rear part of the vehicle body are overlapped and joined at the overlapping portion of the back panel and the joining flange of the rear floor, and the back panel is further provided with the mounting bracket. Since the bending portion is arranged to correspond to the bending portion of the rear edge of the rear floor where the rigidity is increased by the bending and the rigidity is increased, the mounting rigidity of the mounting bracket is improved. Therefore, generation of vibration and noise can be prevented, and the component can be supported by a highly rigid structure. Furthermore, since the mounting bracket can be attached to the back panel that extends long in the vehicle width direction, the degree of freedom in layout regarding the attachment of the components can be increased. Since the three mounting brackets that are arranged together with the joining flanges of the curved portion of the back panel and the bent portion of the rear floor may be joined together, the number of joints can be reduced compared to the conventional case, and the mounting of the components can be reduced. Work can be facilitated. Since the mounting bracket arranged in a limited range of the curved portion of the back panel is small, the vehicle weight can be reduced as compared with the conventional case.
Therefore, the support structure mainly using the back panel increases the degree of layout freedom related to the mounting of the rear part of the vehicle body, facilitates the mounting work of the part, reduces the vehicle weight, and prevents the generation of vibration and noise. In addition, the component can be supported by a highly rigid structure.

  In the lower structure of the rear portion of the vehicle body according to the present invention, the mounting bracket and the back panel are respectively provided at the overlapping portions disposed on both sides with respect to the normal line of the curved portion of the back panel passing over the mounting bracket. And the three rear floors are joined together, so that joints are arranged on both sides with respect to the normal extending obliquely so as to include a vertical component and a vehicle width component. Become. As a result, the mounting rigidity in an oblique direction can be improved, so the mounting bracket mounting rigidity can be improved against vibrations in the low frequency region caused by loads caused by swinging the parts up and down, left and right and back and forth. Further, when the component is a vehicle muffler, the mounting bracket has a mounting rigidity against vibrations in the middle and high frequency regions generated in the vertical direction and the vehicle width direction due to gas flow waves. Can be improved.

  In the lower structure of the rear part of the vehicle body of the present invention, the part is a muffler for a vehicle, and a muffler hanger assembly that supports the muffler for the vehicle is configured and a part of a stay that is attached to the mounting bracket is in the normal line. Since the load is applied to the mounting bracket from the direction of the normal line, the stress generated by the load is efficiently distributed to the joints on both sides of the normal line. In addition, the mounting rigidity of the mounting bracket can be further improved.

  In the lower structure of the rear part of the vehicle body according to the present invention, a bead extending along the normal from a part of the stay arranged on the back panel is formed on the back panel. The rigidity of the back panel with respect to the applied load is improved, the stress generated by the load is reduced, and the mounting rigidity of the mounting bracket can be further improved.

It is a schematic perspective view which shows the external appearance of the vehicle body rear part to which the lower structure of the vehicle body rear part in embodiment of this invention is applied. It is the schematic perspective view which looked at the lower structure of the vehicle body rear part in embodiment of this invention from diagonally upward of the vehicle front side. It is the schematic perspective view which looked at the lower part structure of the vehicle body rear part in the embodiment of the present invention from the slanting lower part on the vehicle back side. In the embodiment of the present invention, it is the outline perspective view which looked at the muffler periphery in the lower structure of the rear part of a vehicle body from the slanting lower part on the vehicle front side. In embodiment of this invention, it is a rear view which shows partially the attachment bracket periphery in the lower structure of a vehicle body rear part. It is AA sectional drawing of FIG. FIG. 10 is a rear view partially showing the periphery of the mounting bracket in the lower structure of the rear part of the vehicle body in the first modification of the embodiment of the present invention.

Hereinafter, with reference to FIGS. 1-6, the lower structure of the vehicle body rear part 1 which concerns on embodiment of this invention is demonstrated.
The main structure of the vehicle body rear portion 1 will be described with reference to FIGS. A rear floor 2 that extends in the horizontal direction is provided at the rear portion 1 of the vehicle body. Both ends in the vehicle width direction of the rear floor 2 are attached to a pair of left and right rear side members 3 extending in the front-rear direction. Further, a rear panel 4 is provided at the vehicle body rear portion 1 so as to contact the rear edge of the rear floor 2 and extend in the vehicle width direction. Further, as a configuration for mounting the muffler 5 which is a component of the rear part 1 of the vehicle body, a mounting bracket 6 and a pipe-like stay 8 constituting the first muffler hanger assembly 7 for suspending the muffler 5 are provided. Yes. The mounting bracket 6 is disposed on the back surface 4 a of the back panel 4, and a stay 8 is attached to the mounting bracket 6. One end 8 a of the stay 8 is formed so as to extend linearly on the back surface 4 a of the back panel 4. On the other hand, the other end portion 8 b of the stay 8 is formed so as to protrude forward under the back panel 4.

  The configuration of the rear floor 2 will be described with reference to FIGS. 2 to 4 and 6. The rear floor 2 is provided with a spare tire house 2a that is recessed downward. Spare tire house 2 a is arranged at the center of rear floor 2 in the vehicle width direction and opens at the rear edge of rear floor 2. Therefore, the rear edge of the rear floor 2 is formed in a hat shape so that the center in the vehicle width direction protrudes downward. On the rear edge of such a rear floor 2, upper bent portions 2b and 2c located on the upper end side of the spare tire house 2a and lower bent portions 2d and 2e located on the bottom side of the spare tire house 2a are formed. The Rukoto. At the rear edge of the rear floor 2, a joining flange 2f extending in the vertical direction is provided (see FIG. 6). In addition, although the flange 2f for joining in this embodiment is extended toward upper direction, it is not limited to this, The flange 2f for joining may be extended toward the downward direction. This joining flange 2f is arranged so as to overlap the back panel 4.

  The configuration of the back panel 4 will be described with reference to FIGS. 2, 3, and 5. The center in the vehicle width direction of the lower part of the back panel 4 is formed to project downward, and the lower part of the back panel 4 corresponds to the upper bent portions 2b and 2c of the rear floor 2 and is located in the upper and vehicle width direction. The upper curved portions 4b and 4c that are curved so as to be recessed toward the center and the lower bent portions 2d and 2e of the rear floor 2 are curved so as to protrude downward and toward the vehicle body end in the vehicle width direction. Lower curved portions 4d and 4e are provided. Further, the back panel 4 is provided with a bead 4f formed so as to be recessed on the back surface 4a. The bead 4f extends from one end 8a of the stay 8 along the extending direction of the one end 8a. It is formed to extend. In this embodiment, the bead 4f is formed to be recessed on the back surface 4a of the back panel 4. However, the present invention is not limited to this, and the bead 4f is formed to protrude on the back surface 4a of the back panel 4. May be.

  With reference to FIGS. 3-5, the structure of the muffler 5 and the structure for supporting the said muffler 5 are demonstrated. The muffler 5 is provided with a silencer 5a formed in a cylindrical shape so as to extend in the front-rear direction. An end pipe 5b protruding rearward is provided at the rear part of the silencer 5a. A center pipe 5c extending forward is provided at the front of the silencer 5a. Such a muffler 5 is disposed between the spare tire house 2 a and the rear side member 3.

  A muffler support member 9 constituting the first muffler hanger assembly 7 is attached to the silencer 5a. Specifically, one end portion 9a of the muffler support member 9 is formed along the side surface of the silencer 5a on the spare tire house 2a side and attached to the side surface. On the other hand, the other end 9b of the muffler support member 9 is formed so as to protrude rearward. The lower end portion 9b of the muffler support member 9 is, together with the other end portion 8b of the stay 8 described above, two penetrating holes formed in the front-rear direction by an annular hanger rubber 10 constituting the first muffler hanger assembly 7. It is attached to each of the holes 10a and 10b. Further, one end 8 a of the stay 8 is disposed along the normal line N of the lower curved portion 4 d of the back panel 4 and is attached to the mounting bracket 6. The normal line N of the lower curved portion 4d passes through the mounting bracket 6 and connects the straight sides (indicated by phantom lines in FIG. 5) of the back panel 4 connected to the curved contour of the lower curved portion 4d. It extends to pass through the intersection. The mounting bracket 6 to which the one end portion 8a of the stay 8 is attached overlaps the joining flange 2f provided on one lower bent portion 2d of the rear floor 2 and one lower curved portion 4d of the back panel 4. It arrange | positions corresponding to the matching part 11. FIG. The other end 8b of the stay 8 and the lower end 9b of the muffler support member 9 are also arranged along the normal line N.

  Such joining of the joining flange 2f, the back panel 4, and the mounting bracket 6 of the rear floor 2 will be described with reference to FIGS. A joining flange 2f provided at one lower bent portion 2d of the rear floor 2, one lower curved portion 4d of the back panel 4, and the mounting bracket 6 are arranged in the overlapping portion 11 in the first three. Three sheets are welded together at a sheet overlap joint 12a, a second sheet overlap joint 12b, a third sheet overlap joint 12c, and a fourth sheet overlap joint 12d. The first three-ply joint point 12a and the second three-ply joint point 12b are arranged on one side with respect to the normal line N, and the third three-ply joint point 12c and the fourth three-ply joint point. 12d is arranged on the other side with respect to the normal line N. In the present embodiment, two three-layer overlapping joints are provided on both sides of the normal line N, but the present invention is not limited to this. The stress generated by the load applied from the stay 9 can be distributed to each of the three lap joint on one side with respect to the normal N and the three lap joint on the other side with respect to the normal N. For example, at least one three-ply joint location may be provided on each side of the normal line N.

  Also, the lower curved portion 4d on one side of the back panel 4 and the mounting bracket 6 include a first two-layer joint portion 13a, a second two-layer joint portion 13b, and a third two-layer joint portion 13c. , And the fourth two-ply joint location 13d is overlapped and welded. The first two-layer joint portion 13a and the second two-layer joint portion 13b are arranged on one side with respect to the normal line N, and the third two-layer joint portion 13c and the fourth two-layer joint portion. 13d is arranged on the other side with respect to the normal line N. In the present embodiment, two double-lap joints are provided on both sides of the normal line N, but the present invention is not limited to this. The stress generated by the load applied from the stay 9 can be distributed to each of the three lap joint on one side with respect to the normal N and the three lap joint on the other side with respect to the normal N. For example, it is only necessary that at least one double-lap joint portion is provided on each side of the normal line N.

  Further, referring to FIG. 4, a second muffler hanger assembly 14 and a third muffler hanger assembly 15 for suspending the muffler 5 are provided. The second muffler hanger assembly 14 connects the side surface of the silencer 5a on the side of the rear side member 3 and the portion of the surface 4g of the back panel 4 that is located on the outer side in the vehicle width direction. In addition, the third muffler hanger assembly 15 connects between the front part of the silencer 5a and the part of the rear floor 2 that is located in front of the silencer 5a. Therefore, the muffler 5 is supported by the first muffler hanger assembly 7, the second muffler hanger assembly 14, and the third muffler hanger assembly 15.

A method for assembling the lower structure of the vehicle body rear portion 1 according to the embodiment of the present invention will be described.
The mounting bracket 6 to which the stay 8 is attached is disposed on the lower curved portion 4d so that the one end portion 8a of the stay 8 is along the normal line N of one lower curved portion 4d of the back panel 4. The back panel 4 and the mounting bracket 6 are arranged with respect to the normal line N, the first two-sheet overlap joint location 13a and the second two-sheet overlap joint location 13b, and the other to the normal line N. Two sheets are overlap-welded at the third two-sheet overlap joint location 13c and the fourth two-sheet overlap joint location 13d.
The upper curved portions 4b and 4c of the back panel 4 to which the mounting bracket 6 is attached are aligned with the upper bent portions 2b and 2c of the rear floor 2, and the lower curved portions 4d and 4e of the back panel 4 are aligned with the lower bent portion 2d of the rear floor 2. , 2e, the back panel 4 is disposed so as to overlap the joining flange 2f of the rear floor 2. The joining flange 2f, the back panel 4, and the mounting bracket 6 of the rear floor 2 are arranged on the one side with respect to the normal line N by the first three-ply joint location 12a and the second three-ply joint. Three pieces of lap welding are performed at the place 12b, the third three-ply joint part 12c disposed on the other side with respect to the normal N, and the fourth three-ply joint part 12d.
The muffler 5 to which the muffler support member 9 is attached is disposed below the rear floor 2. The other end portion 8 b of the stay 8 and the other end portion 9 b of the muffler support member 9 are inserted into the through holes 10 a and 10 b of the hanger rubber 10, respectively, and the muffler 5 is attached to the vehicle body rear portion 1.

As described above, according to the embodiment of the present invention, the three mounting brackets 6 for mounting the muffler 5 are overlap-welded at the overlapping portion 11 between the joining flange 2f of the rear floor 2 and the back panel 4, and The bending portion 4d of the back panel 4 on which the mounting bracket 6 is disposed is arranged corresponding to the bent portion 2d of the rear floor 2 whose rigidity is increased by the bending, and thus the mounting rigidity of the mounting bracket 6 is increased. Will be improved. Accordingly, vibration and noise can be prevented and the muffler 5 can be supported by a highly rigid structure. Furthermore, since the mounting bracket 6 can be attached to the back panel 4 that extends long in the vehicle width direction, the degree of freedom in layout regarding the attachment of the muffler 5 can be increased. Since three mounting brackets 6 arranged to overlap with the joining flange 2f of the lower bent portion 2d of the rear floor 2 and the lower curved portion 4d of the back panel 4 may be welded together, the joining portion is compared with the conventional case. Therefore, the muffler 5 can be easily attached. Since the mounting bracket 6 disposed in the limited range of the curved portion 4d of the back panel 4 is small, the vehicle weight can be reduced compared to the conventional case.
Therefore, the support structure mainly using the back panel 4 increases the degree of layout freedom regarding the attachment of the muffler 5, facilitates the attachment work of the muffler 5, reduces the vehicle weight, and prevents the generation of vibration and noise. The muffler 5 can be supported by a highly rigid structure.

  According to the embodiment of the present invention, the first three-layer joint portion 12a and the second one on the one side with respect to the normal N extending in the oblique direction so as to include the vertical component and the vehicle width component. The three-sheet overlap joint 12b is disposed on the other side with respect to the normal line N, and the third three-layer overlap joint 12c and the fourth three-sheet overlap joint 12d are disposed. As a result, the mounting rigidity in an oblique direction can be improved, so the mounting rigidity of the mounting bracket 6 is improved against vibrations in a low frequency region generated by a load accompanying the swing of the muffler 5 in the vertical and horizontal directions. The mounting rigidity of the mounting bracket 6 can be improved against vibrations in the middle and high frequency regions generated in the vertical direction and the vehicle width direction by the gas flow wave generated in the muffler 5.

  According to the embodiment of the present invention, the end 8 a of the stay 8 attached to the mounting bracket 6 is formed so as to extend along the normal line N, so that the load from the muffler 5 is normal to the mounting bracket 6. It will be added from the direction of N. Therefore, the stress generated by the load is efficiently applied to the normal line N with respect to the normal line N and the first three-ply joint part 12a and the second three-ply joint part 12b on one side. The mounting rigidity of the mounting bracket 6 can be further improved by being dispersed in the third three-ply joint part 12c and the fourth three-ply joint part 12d on the other side.

  According to the embodiment of the present invention, the bead 4f extending along the normal line N from the one end 8a of the stay 8 disposed on the back panel 4 is formed on the back panel 4, and therefore the direction of the normal line N The rigidity of the back panel 4 with respect to the load applied from the load is improved, the stress generated by the load is reduced, and the mounting rigidity of the mounting bracket 6 can be further improved.

  Although the embodiments of the present invention have been described so far, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

  For example, as a first modification of the present embodiment, the mounting bracket 6 may be disposed on one upper curved portion 4b of the back panel 4 as shown in FIG. Further, the mounting bracket 6 may be disposed on the other upper curved portion 4c. The same effect as this embodiment can be obtained.

  As a second modification of the present embodiment, the mounting bracket 6 may be disposed on the other lower curved portion 4e. The same effect as this embodiment can be obtained.

  As a third modification of the present embodiment, the parts of the vehicle body rear portion 1 may be other than the muffler 5. The same effect as this embodiment can be obtained.

  As a fourth modification of the present embodiment, the joining method of the three-lap joint locations 12a to 12d and / or the two-lap joint locations 13a to 13d may be a method other than welding. The same effect as this embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 Car body rear part 2 Rear floor 2b, 2c Upper bending part 2d, 2e Lower bending part 2f Joining flange 4 Back panel 4a Back surface 4b, 4c Upper bending part 4d, 4e Lower bending part 4f Bead 5 Muffler 6 Mounting bracket 7 First Muffler hanger assembly 8 stay 8a one end portion 11 overlap portion 12a first three-layer joint portion 12b second three-layer joint portion 12c third three-layer joint portion 12d fourth three-layer joint portion 13a First two-ply joint point 13b Second two-ply joint point 13c Third two-ply joint point 13d Fourth two-ply joint point N Normal

Claims (4)

The rear panel of the rear floor of the vehicle is bent in a hat shape so that the center in the vehicle width direction protrudes downward, and a joining flange extending in the vertical direction is provided on the rear edge of the rear floor, and the back panel extends in the vehicle width direction. In the lower structure of the rear part of the vehicle body, which is configured such that the joining flange of the rear floor and the back panel are arranged so as to be able to attach components arranged on the rear part of the vehicle body,
The center in the vehicle width direction of the lower edge of the back panel is formed to protrude downward so as to have a curved portion corresponding to the bent portion of the rear floor rear edge,
A mounting bracket for mounting the component is disposed on the back surface of the back panel, and three sheets are joined at the overlapping portion of the joining flange provided on the bent portion of the rear floor and the curved portion of the back panel. The lower structure of the rear part of the vehicle body, characterized in that   Three pieces of the mounting bracket, the back panel, and the rear floor are overlapped and joined at each of the overlapping portions arranged on both sides with respect to the normal line of the curved portion of the back panel passing over the mounting bracket. The lower structure of the rear part of the vehicle body according to claim 1, wherein   The component is a vehicle muffler, the muffler hanger assembly that supports the vehicle muffler is configured, and a part of the stay that is attached to the mounting bracket is formed to extend along the normal line. The lower structure of the rear part of the vehicle body according to claim 2, characterized in that: The lower structure of the rear part of the vehicle body according to claim 3, wherein a bead extending along the normal from a part of the stay arranged on the back panel is formed on the back panel.

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