JP4513475B2 - Rear body structure of the vehicle - Google Patents

Description

  The present invention relates to a rear body structure of a vehicle provided with a reinforcing member for attaching a differential box on the rear wheel side of an automobile.

  In the case of a four-wheel drive vehicle, a rotational moment is generated in a differential box (hereinafter referred to as a rear differential) provided on the rear wheel side by a driving force from the rear wheel side drive shaft. Therefore, the rear differential needs to be provided with a support structure for receiving a load caused by this rotational moment.

  As a conventional support structure, there is a structure in which a rear differential is fastened directly under a highly rigid cross member provided on a vehicle body side of an automobile. According to this structure, since the rear differential can be securely attached, the displacement of the rear differential is reduced, and the rigidity of the support point is high, so that the vibration of the rear differential and the noise due to this vibration are reduced.

Patent Documents 1 and 2 disclose a structure in which a front cross member is provided in addition to a rear cross member, and a rear differential is attached by these two members. Patent Document 1 discloses a structure for attaching a rear differential via a bracket in addition to the above-described technique.
JP 2000-168618 A Japanese Patent Laid-Open No. 10-147254

  However, when the rear differential is attached to the vehicle body, the rear differential may not be disposed directly below the cross member depending on the vehicle type. For example, as shown in FIG. 6, when designing a small displacement vehicle, a compact structure is required as a whole, and the distance between the fuel tank housing 50 and the spare tire house 51 is narrower than that of a normal vehicle. Limited. In this case, a front cross member cannot be provided in addition to the cross member 54 as in the above-mentioned patent document. In order to ensure the same suspension performance as that of a two-wheel drive vehicle, a rear suspension 53 having a beam 52 extending in the vehicle width direction may be selected. Since the beam 52 is disposed in the vicinity of the cross member 54, there is a restriction that a rear differential must be attached at a position where the beam 52 does not interfere with the beam 52.

On the other hand, it is conceivable to change the attachment position of the cross member 54. However, since the cross member 54 contributes to the overall rigidity of the vehicle body, shifting the position reduces the vehicle body rigidity. Further, since the beam 52 also contributes to the suspension performance, changing the mounting position of the beam 52 results in performance degradation. Furthermore, when a mounting stay is provided on the vehicle body side other than the cross member 54, the number of parts increases to reinforce the rigidity of the support point of the rear differential, and the weight increases as a whole.
In such a restricted state, it was difficult to attach the rear differential directly below the cross member.

  An object of the present invention is to provide a rear body structure of an automobile in which a support point for supporting a differential box can be provided without changing the position of a beam of a cross member and a suspension.

In the present invention, in a vehicle rear body structure provided with left and right side frames extending in the longitudinal direction of the vehicle body and a cross member connecting the left and right side frames, the left and right side frames and the cross member A brace is provided around each of the connecting portions, and one end portion of the brace is attached to a position shifted to the left and right from the center portion of the cross member, and the other end portion of the brace extends obliquely outward in the rearward direction of the vehicle. And are attached to the left and right side frames, and the brace is provided with a support point for attaching a rear differential box.

Further, a rear floor panel is attached to the left and right side frames and the cross member, and a flange surface that contacts the rear floor panel is formed on the brace, and the rear floor panel and the flange surface are fixed by welding.
Furthermore, the rear floor panel is provided with a tire storage portion that protrudes downward from the vehicle, and the brace is disposed at a position that does not interfere with the tire storage portion.

In the present invention, in a vehicle rear body structure provided with left and right side frames extending in the longitudinal direction of the vehicle body and a cross member connecting the left and right side frames, the left and right side frames and the cross member A brace is provided around each of the connecting portions, and one end portion of the brace is attached to a position shifted to the left and right from the center portion of the cross member, and the other end portion of the brace extends obliquely outward in the rearward direction of the vehicle. Since the support point for attaching the rear differential box is provided on the brace, the portion that can support the rear differential box is formed on the side frame and the cross member. Can be provided. Moreover, since the strength of the connecting portion between the side frame and the cross member is increased, a more rigid vehicle body structure can be obtained. Further, by providing the support point of the rear differential box not in the cross member but in the brace, the mounting structure of the rear differential box can be configured without changing the position of the beam of the cross member or the suspension. In addition, since it is not necessary to configure the rear differential box mounting structure in a complicated manner, the rear differential box can be supported so as to reduce the vibration of the rear differential box and noise caused by the vibration more reliably. Further, the shape of the brace can be formed to the minimum necessary size.

Further, a rear floor panel is attached to the left and right side frames and the cross member, and the brace is formed with a flange surface in contact with the rear floor panel, and the rear floor panel and the flange surface are fixed by welding. The brace mounting strength can be increased, and the side frame, cross member, brace and rear floor panel can be integrated to provide sufficient rigidity.
Further, the rear floor panel is provided with a tire storage portion that protrudes downward from the vehicle, and the brace is disposed at a position that does not interfere with the tire storage portion, so that the protruding shape of the existing tire storage portion is changed. The brace can be configured on the rear vehicle body.

  Hereinafter, a rear body structure of a vehicle according to an embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 shows a state where a rear vehicle body structure according to an embodiment of the present invention is viewed from the lower side of the vehicle body. In FIG. 1, the upper side of the paper is the front of the vehicle, and the lower side of the paper is the rear of the vehicle.

  Side members 1 extending in the front-rear direction are provided on the left and right sides of the automobile, and a cross member 2 extending in the vehicle width direction is connected between the left and right side frames 1. A rear floor panel 3 is provided above the side frame 1 and the cross member 2 so as to cover the entire surface between the left and right side frames 1. On the rear floor panel 3, a tire storage portion 4 is formed on the vehicle rear side of the cross member 2 so as to protrude to the vehicle lower side.

  Braces 6 are respectively provided around the left and right connecting portions 5 in the vehicle width direction between the left and right side frames 1 and the cross member 2. The braces 6 are connected to the side frames 1 and the cross member 2 at both ends of the brace 6. Part is attached. Specifically, one end portion 7a of the brace 6 is attached to a position shifted from the center portion of the cross member 2 to the left and right, and the brace 6 extends from the one end portion 7a obliquely outwardly toward the rear of the vehicle. The end 7b is attached to a position on the rear side of the vehicle body relative to the cross member 2 of the side frame 1.

  Note that the shape of the connecting portion 5 with the brace 6 attached is such that the brace 6 does not interfere with the tire storage portion 4. Moreover, the attachment position of the one end part 7a and the other end part 7b is provided in the part as far as possible from the connection part 5 so that the intensity | strength of the connection part 5 may improve.

  FIG. 2A and FIG. 2B show a single state of the left and right braces 6. The brace 6 includes a brace body 10 and a reinforcing body 20. In the following description, the shape of the brace 6 attached to the right side of the vehicle body will be described.

  FIG. 3A shows a single item of the brace body 10. The brace body 10 has a substantially U-shaped cross section, and is formed with a bottom portion 10a and wall portions 10b bent substantially vertically from both ends of the bottom portion 10a. At the edge of the wall portion 10b in the direction in which the wall portion 10b is raised, a flange portion 11 that is bent by about 90 ° in the outer direction of the brace body 10 is formed. Further, contact surfaces 13a and 13b that are substantially perpendicular to the wall portion 10b and the flange portion 11 are formed at both longitudinal edges of the wall portion 10b. The interval between the two wall portions 10b is formed so as to become wider as it approaches the one end portion 12a in the longitudinal direction of the flange body 10, and five holes 14 are provided in the bottom portion 10a of the wide portion. 3 places are used for attachment, and the other 2 places are used for positioning. In addition, the one end part 12a and the other end side 12b of the brace body 10 are provided with flat surfaces 15a and 15b in which the wall part 10b and the flange part 11 are not formed.

  FIG. 4A shows a single article of the reinforcing body 20. The reinforcing body 20 is provided at a support point for supporting a rear differential (not shown), and is for reinforcing the support point. The reinforcing body 20 includes an upper surface portion 20a and a wall portion 20b formed by bending the upper surface portion 20a substantially vertically. As shown in FIG. 2, the outer shape of the upper surface portion 20a is formed so as to be attached to a portion where the space between the wall portions 10b of the brace body 10 is wide. Installed in contact. The upper surface portion 20a is provided with five holes 21 that coincide with the holes 14 of the bottom portion 10a. The holes 21 are used for mounting and positioning, respectively. The wall portion 20b is in surface contact with the wall portion 10b, thereby reinforcing the brace body 10 with the reinforcing body 20.

  As shown in FIGS. 3B and 4B, the brace 6 attached to the left side of the vehicle body has the same configuration as that of the right side brace 6 and is slightly different in size according to the installation space. Other than that, the function is the same.

Next, a method for attaching the brace 6 according to the embodiment of the present invention will be described. FIG.
The state which attached the brace 6 to the side frame 1 and the cross member 2 is shown. The brace 6 is attached in a state where the side frame 1 and the cross member 2 are connected.
As shown in FIG. 5, the brace 6 is attached in a state where the opening portion having a U-shaped cross section faces the vehicle upper side (the front side in FIG. 5). At this time, the contact surface 13a on one end side of the brace main body 10 is brought into contact with the rear side surface 2a of the cross member 2 on the surface, and the contact surface 13b on the other end side of the brace main body 10 is connected to each of the left and right side frames 1. The brace 6 is attached by bringing the inner side surface 1a into contact with each other and bringing the flat surfaces 15a and 15b of the brace body 7 into contact with the side frames 1 and the lower body side surfaces 1b and 2b of the cross member 2, respectively. The position is determined. And the brace 6, the side frame 1, and the cross member 2 are firmly attached to the connecting portion by, for example, all-around welding.

  Next, the floor panel 3 is attached to the upper side of the side frame 1, the cross member 2, and the brace 6 so as to cover the entire surface thereof, and is fixed by welding. At this time, the flange portion 11 of the brace body 7 comes into contact with the vehicle lower side surface of the rear floor panel 3 and the contact portion is firmly fixed by welding.

  In the rear body structure of the automobile according to the embodiment of the present invention, the following effects can be obtained. (1) Although the brace 6 is offset from the cross member 2 to the rear side of the vehicle, loads in the vehicle up-down direction and left-right direction act on the brace 6 by attaching the other end portions 7b to the left and right side frames 1. Even in this case, the displacement and vibration of the brace 6 can be reduced. Further, by attaching the flange portion 11 of the brace 6 to the rear floor panel 3, the side frame 1, the cross member 2, the rear floor panel 3, and the brace 6 can be integrated, and the above-described displacement and vibration can be further reduced.

(2) When a load from the bumper at the rear of the vehicle is applied, the load transmitted from the side frame 1 to the cross member 2 can be dispersed in the two directions of the side frame 1 and the brace 6. Thereby, the load absorption effect is improved.

It is the perspective view which looked at the vehicle body rear part structure which concerns on embodiment of this invention from the vehicle lower side. It is a perspective view of the brace for reinforcement concerning an embodiment of the invention. It is a perspective view of the brace body concerning an embodiment of the invention. It is a perspective view of the reinforcement body which concerns on embodiment of this invention. It is a perspective view which expands and shows the attachment part of the brace which concerns on embodiment of this invention. It is the perspective view which looked at the conventional motor vehicle from the vehicle body lower side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Side frame 1a Inner side surface of the side frame 1b Lower side surface of the side frame 2 Cross member 2a Rear side surface of the cross member 2b Lower side surface of the cross member 3 Rear floor panel 4 Tire storage portion 5 Connection portion 6 Brace 7a One end portion of the brace 7b Other end portion 10 Brace body 11 Flange portion 12a One end portion of brace body 12b Other end portion of brace body 13a Contact surface on one end side 13b Contact surface on the other end side 14 Hole 15a Flat surface on one end side 15b Flat surface on the other end side DESCRIPTION OF SYMBOLS 20 Reinforcement body 20a Upper surface part 20b Wall part 21 Hole 50 Fuel tank storage part 51 Spare tire house 52 Beam 53 Rear suspension 54 Cross member

Claims (3)

In the vehicle rear body structure provided with left and right side frames extending in the longitudinal direction of the vehicle body and a cross member connecting the left and right side frames,
Braces are provided around the connecting portion between the left and right side frames and the cross member, and one end of the brace is attached to a position shifted from the center of the cross member to the left and right. The rear portion of the vehicle is characterized in that an end portion is formed to extend obliquely outward in the rearward direction of the vehicle, is attached to the left and right side frames, and a support point for attaching a rear differential box is provided on the brace. Body structure. A rear floor panel is attached to the left and right side frames and the cross member, and a flange surface in contact with the rear floor panel is formed on the brace, and the rear floor panel and the flange surface are fixed by welding. The rear body structure of the vehicle according to claim 1. The rear vehicle body structure according to claim 2 , wherein the rear floor panel is provided with a tire storage portion that protrudes downward from the vehicle, and the brace is disposed at a position that does not interfere with the tire storage portion. .

Images