JP5358213B2 - Car body rear structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle body rear structure capable of increasing the strength against the load of rear-end collision. <P>SOLUTION: The vehicle body rear structure 11 comprises rear side frames (a left rear side frame 27, a right rear side frame 28) extending backward of a vehicle from right and left sides of a floor (an under-body 21) of a cabin 14, and a cross member (a second rear cross member 33) coupling both ends (a left end 51, a right end 52) to the rear side frames, respectively. A front end 54 of a rear portion 45 of the rear side frame (the left rear side frame 27) is butted to the cross member (the second rear cross member 33), and surrounded by a circumferential wall 63 included in a front portion 44 of the rear side frame (the left rear side frame 27) coupled with the cross member (the second rear cross member 33), and welded thereto (a weld bead 62). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a rear structure of a vehicle body that has increased strength against a load when a rear-end collision occurs.

  Vehicles generally extend the left and right rear side frames from the left and right sides of the passenger compartment to the rear of the vehicle so as to respond to the impact (load) when the luggage compartment provided behind the passenger compartment is impacted. It is. If the rear side frame is extended to the same width as the vehicle width of the passenger compartment, it will interfere with the rear wheels, so it will be bent toward each other and further bent upward toward the floor of the luggage compartment located above. ing. Some of them are bent in an arch shape in the vehicle side view so as to support the cylindrical damper of the rear suspension in the vicinity of the rear wheel (see, for example, Patent Document 1 (FIG. 1)).

However, in the prior art (Patent Document 1), when a rear-end collision occurs, the rear side frame tends to start bending from an arch-shaped bent portion due to the load at the time of the rear-end collision, and the load is transmitted forward from the bent portion. There is a problem that the strength against the load of the rear-end collision is small. The lower part of the rear side frame transmits the rear-end collision load to the lower part of the sub-frame, for example, a cross-shaped subframe, but the front part of the sub-frame is offset downward with respect to the floor of the passenger compartment. It is difficult to transmit the load from the vehicle to the floor of the passenger compartment.
In addition, since the rear side frame employs a tubular member, it is difficult to ensure accuracy if bent in an arch shape in the middle.

JP 2006-240451 A

  It is an object of the present invention to provide a vehicle body rear structure with increased strength against a rear-end collision load.

In order to solve the above-mentioned problems, the invention according to claim 1 is a rear side frame having a hollow cross section extending from the left and right sides of the passenger compartment to the rear of the vehicle, and disposed between the rear side frames. In the rear structure of the vehicle body , the first and second rear cross members are coupled to each other , and the second rear cross member is located in front of the first rear cross member. front end abuts on the second rear cross member, and, in the peripheral wall included in the front portion of the rear side frame coupled to the second rear cross member, is wrapped by welding, first rear cross of within the rear of the rear side frames A portion corresponding to the second rear cross member from the member is provided with an overlapping member having a hollow cross section .
The invention according to claim 2 further includes a middle cross member disposed between the rear side frames in front of the second rear cross member and having both end portions coupled to the center of the front portion of the left and right rear side frames, Left and right vertical frames are passed and joined from the center in the vehicle width direction of the middle cross member to the center in the vehicle width direction of the second rear cross member.

In the invention according to claim 1, the rear side frame in the vehicle body rear portion structure that includes a second rear cross member which is attached to both end portions respectively to the rear side frames, rear side frames, the front end of the rear second rear cross Since it is wrapped and welded to the peripheral wall included in the front part of the rear side frame that is abutted against the member and joined to the second rear cross member, the impact when the rear impact is made mainly from the rear part of the rear side frame The proportion of the impact transmitted directly to the second rear cross member and transmitted to the front portion of the rear side frame at the welded portion is reduced, and the proportion depending on the welded portion can be lowered.
That is, it is possible to increase the strength against the rear-end collision load.

It is a perspective view of the vehicle body rear part structure which concerns on the Example of this invention. It is a perspective view of the rear side frame of the vehicle body rear part structure which concerns on the Example of this invention. It is a side view of the rear side frame of the vehicle body rear part structure which concerns on the Example of this invention. It is a figure which shows the coupling | bonding of the rear side frame and cross member of a vehicle body rear part structure. It is a back detailed drawing of the rear side frame of a vehicle body rear part structure. It is a figure explaining the detailed view of the coupling | bonding of the rear part of a rear side frame, a front part, and a cross member, and the mechanism of load transmission. It is a figure explaining the mechanism of load transmission of a body rear part structure.

  Hereinafter, embodiments of the present invention will be described in detail with reference to examples. 1 shows a state in which the rear structure of the vehicle body is looked up from below the vehicle, and FIG. 4 shows a state in which the vehicle is inverted upside down.

  As shown in FIG. 1, the vehicle body rear part structure 11 according to the embodiment is adopted at the rear part of the vehicle 12, forms the floor of the luggage room 15 behind the vehicle compartment 14, and when the vehicle 12 is collided, 15 deformation is suppressed. This will be specifically described below.

  The vehicle 12 includes a vehicle compartment 14, a luggage compartment 15, and a vehicle body 17. The vehicle body 17 includes an underbody 21 that forms a floor of the vehicle compartment 14 and a floor of the luggage compartment (trunk room) 15, and a vehicle compartment 14. A left side body 22 and a right side body 23 that form side walls, and a rear body 24 that forms a wall of a luggage room (trunk room) 15 are provided.

  As shown in FIGS. 1 to 4, the underbody 21 includes a left rear side frame 27 that extends from the left and right sides of the passenger compartment 14 toward the rear of the vehicle (the direction of the arrow a <b> 1) in the vehicle front-rear direction (X-axis direction). The rear side frame 28, a middle cross member 31 disposed in the vehicle width direction (Y-axis direction) at the rear portion of the passenger compartment 14, and a rear portion of the trunk room 15 extending in the vehicle width direction in parallel to the middle cross member 31 The first rear cross member 32, the second rear cross member 33, the left vertical frame 34 extending from the second rear cross member 33 to the middle cross member 31, the right vertical frame 35, and the rear floor pan of the trunk room 15. 36, a rear bumper attached to the rear end of the left rear side frame 27 and the rear end of the right rear side frame 28. It includes an over arm 37, a.

  Here, the rear body structure 11 of the vehicle body will be described mainly with the left and right sides of the vehicle 12 being substantially symmetrical with respect to the center in the vehicle width direction (Y-axis direction).

  In the rear body 24, a damper housing 41 for fastening a damper of a rear suspension (not shown) supporting a rear wheel (not shown) is formed of an aluminum (light alloy) casting. A lower portion of the housing 41 is supported by the left rear side frame 27.

  The left rear side frame 27 includes a front part 44 coupled to the side sill 42 of the left side body 22 and a rear part 45 connected to the front part 44. Details will be described later.

The vehicle body rear structure 11 has a rear side frame (left rear side frame 27) that extends from the left and right sides of the floor (underbody 21) of the vehicle compartment 14 to the rear of the vehicle (in the direction of arrow a1), as already described with reference to FIGS. A right rear side frame 28) and a cross member (second rear cross member 33) disposed between the rear side frames and connecting both end portions (the left end portion 51 and the right end portion 52) to each other. I have.
The rear side frame (left rear side frame 27) has a rear side frame in which the front end 54 of the rear portion 45 is abutted against the cross member (second rear cross member 33) and is coupled to the cross member (second rear cross member 33). The peripheral wall 63 included in the front portion 44 of the (left rear side frame 27) is wrapped and welded (weld bead 62).

  The middle cross member 31 has both ends coupled to the center of the front portion 44 of the left rear side frame 27 and the center of the front portion 44 of the right rear side frame 28, and the left vertical frame 34 at the center in the vehicle width direction. One end of the right vertical frame 35 is coupled, and the other end is coupled to the center of the second rear cross member 33 in the vehicle width direction, whereby the second rear cross member 33 is coupled.

  The second rear cross member 33 has both end portions (the left end portion 51 and the right end portion 52) in the rear fitting portion 65 provided in the front portion 44 of the left rear side frame 27 and the right rear side frame 28. This is an extruded material of aluminum (light alloy) that enters and is joined into a rear fitting portion 65 provided in the front portion 44 of the steel.

  The first rear cross member 32 is an extruded material of aluminum (light alloy) whose both ends are coupled to the center of the rear portion 45 of the left rear side frame 27 and the center of the rear portion 45 of the right rear side frame 28. One end of both ends is coupled to the left rear side frame 27 by the first reinforcing bracket 67 and the second reinforcing bracket 71. The other end is connected to the right rear side frame 28 by the first reinforcing bracket 67 and the second reinforcing bracket 71.

Next, the front portion 44 of the rear side frame (left rear side frame 27) will be described in detail with reference to FIGS.
The front portion 44 has a front coupling portion 73 (similar to the right rear side frame 28) coupled to the side sill 42, and a central portion 74 connected to the front coupling portion 73 in the center in the vehicle width direction, in other words, the inside of the vehicle 12 (arrow in the direction of a3) and upward (in the direction of arrow a4) and further toward the rear of the vehicle, that is, obliquely rearward, and is connected to the central portion 74 at the left end 51 of the second rear cross member 33. After reaching, a coupling part 75 is formed.

  The rear coupling portion 75 is an inner wall fitting opening 78 (fitting and coupling the left end portion 51 of the second rear cross member 33 to the inner wall 77 facing the inside of the vehicle 12 (in the direction of the arrow a3). (Included in the rear fitting portion 65) is opened, and a fitting cylinder portion 81 is formed that is orthogonal to the second rear cross member 33 fitted in the inner wall fitting opening 78 and faces the opening toward the rear of the vehicle. Yes.

  The front end 54 of the rear portion 45 of the rear side frame (left rear side frame 27) is fitted through the fitting cylinder portion 81, and the front end 54 is abutted against the second rear cross member 33. The front end 54 is welded to the peripheral wall 63 of the fitting cylinder 81 by fillet welding (weld bead 62).

The material of the front portion 44 of the rear side frame (left rear side frame 27) is a cast of aluminum (light alloy).
The fitting cylinder portion 81 includes a peripheral wall 63, and has a size in which the rear portion 45 of the rear side frame (left rear side frame 27) is fitted with a clearance fit, so that the welding operation of fillet welding (weld bead 62) is easy. Become.

Next, the rear portion 45 of the rear side frame (left rear side frame 27) will be described in detail.
The rear portion 45 extends from the second rear cross member 33 to the vicinity of the arrangement position of the rear bumper beam 37 in a state of being coupled to the front portion 44, and is mainly formed by the frame main body 84.
The frame main body 84 is coupled with a front end 54, a rear end 85 that faces the front end 54 and supports the rear bumper beam 37, a central damper housing coupling portion 86 that couples the damper housing 41, and the first rear cross member 32. A central first cross coupling portion 87 is provided.

  As shown in FIGS. 4 to 6, the frame main body 84 is obtained by putting the overlapping member 56 into the main body 55. Specifically, the overlapping member 56 is disposed in a range (length) that is not desired to be deformed when the vehicle 12 is collided, and the main body 55 is provided in order from the upper level where the rear floor pan 36 of the trunk room 15 is overlapped. And an intermediate body 92 and a lower body 93 which is a lower part, and the first rear cross member 32 is placed in contact with the front edge 95 of the lower body 93 and arranged in the first cross coupling portion 87, and The first reinforcing bracket 67 and the second reinforcing bracket 71 hold it.

  Further, the frame main body 84 forms a two-layer thick frame portion by fitting the overlapping member 56 in the intermediate body 92 and integrally fixing the intermediate member 92 with the rivets 57. The outer surface of the two-layer thick frame portion (the frame main body) 84, the first reinforcing bracket 67 is overlapped on the outer wall 96 facing the outside of the vehicle 12, and the three laps are fixed with the rivets 57, and the lower wall 97 facing the lower side of the vehicle 12 is fixed. The second reinforcing bracket 71 is overlapped with the rivets 57 and the three reinforced rivets 57 are fixed in a state where the three sheets are overlapped.

  As shown in FIG. 5, the upper body 91 has a substantially U-shaped cross section, the width coincides with the intermediate body 92, and the edge 103 is integrally connected to the side wall portion 104 of the intermediate body 92. In other words, the opening is sealed with the intermediate body 92. The thickness of the upper body 91 is tu.

The intermediate body 92 has a substantially rectangular shape in cross section and is formed with a thickness of tm.
The lower body 93 (lower part) has a groove shape in which one side of a substantially octagonal cross section is cut, and the edge 106 is integrally connected to the lower wall portion 105 of the intermediate body 92. In other words, the opening is sealed with the lower wall portion 105 of the intermediate body 92. The thickness of the lower body 93 is tw.

  The thickness tu of the upper body 91, the thickness tm of the intermediate body 92, and the thickness tw of the lower body 93 are substantially the same as the thickness of a commonly used aluminum rear side frame, and are thinner than the overlapping member 56.

The overlapping member 56 is sized to enter the rear portion 45 of the rear side frame (the left rear side frame 27). Specifically, the overlapping member 56 has a shape along the inner surface of the rear portion 45, and a minute gap between the inner surface of the rear portion 45 ( This is an extruded material of aluminum having a size set to be contactable. The length is from the first rear cross member 32 to the second rear cross member 33.
The thickness tb of the overlapping member 56 is thicker than the thickness tu of the upper body 91, the thickness tm of the intermediate body 92, and the thickness tw of the lower body 93.

Next, the operation of the vehicle body rear structure 11 according to the embodiment of the present invention will be described with reference to FIGS.
In the rear structure 11 of the vehicle body, when the rear impact is input to the rear portion 45, the rear portion 45 (the frame main body 84) directly applies the load to the cross member (second rear cross member 33) as indicated by an arrow b1. This reduces the load distributed to the welded portion (welded portion including the weld bead 62) with the front portion 44 of the rear side frame (left rear side frame 27). As a result, the strength of the rear side frame (left rear side frame 27) can be increased as compared with the case where the load is transmitted only by the portion welded to the front portion 44 (the welded portion including the weld bead 62).

  In addition, although the vehicle body rear part structure of this invention is employ | adopted as the rear part in embodiment, it is employable also at a vehicle body front part.

  The rear body structure of the present invention is suitable for a cylindrical member that is included in an underbody of a vehicle and extends in the vehicle front-rear direction.

DESCRIPTION OF SYMBOLS 11 ... Vehicle body rear structure, 14 ... Car compartment, 21 ... Floor (underbody), 27 ... Rear side frame (left rear side frame), 28 ... Rear side frame (right rear side frame), 31 ... Middle cross member, 32 ... 1st rear cross member, 33 ... second rear cross members, 34 ... (left) longitudinal frame, 35 ... (right) vertical frame, 44 ... front portion of the rear side frame, 45 ... rear, 51 ... end (left End), 52 ... end (right end), 54 ... rear front end, 56 ... overlapping member, 62 ... weld bead, 63 ... peripheral wall.

Claims (2)

A rear side frame having a hollow cross section extending from the left and right sides of the passenger compartment floor to the rear of the vehicle;
A first and a second rear cross member disposed between the rear side frames and coupled to both ends, respectively ;
In the vehicle body rear structure in which the second rear cross member is positioned forward with respect to the first rear cross member ,
The rear side frame has its front end abutted against the second rear cross member, and is wrapped and welded to a peripheral wall included in the front portion of the rear side frame coupled to the second rear cross member .
A vehicle body rear structure, characterized in that an overlapping member having a hollow cross section is inserted in a portion corresponding to the second rear cross member from the first rear cross member in the rear portion of the rear side frame . A middle cross member disposed between the rear side frames in front of the second rear cross member and having both ends coupled to the center of the front part of the left and right rear side frames;
The left and right vertical frames are passed and joined from the center in the vehicle width direction of the middle cross member to the center in the vehicle width direction of the second rear cross member. Car body rear structure.

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