JP5238539B2 - Car body rear structure - Google Patents

Description

  The present invention relates to a vehicle body rear structure that suppresses deformation when a rear-end collision occurs.

  In general, when a vehicle is bumped, the left and right rear side frames are extended from the left and right sides of the passenger compartment floor toward the rear of the vehicle so as to suppress deformation of the rear luggage compartment. When the rear side frame is extended from the passenger compartment floor with the same vehicle width, the rear side frame is bent because it interferes with the rear wheels, and is further bent upward toward the floor of the luggage compartment located above. Then, there is one that is bent in an arch shape in a side view in the vicinity of the rear wheel so as to support the cylindrical damper that the rear suspension expands and contracts on the floor of the passenger compartment (for example, see Patent Document 1 (FIG. 1). )reference).

However, in the prior art (Patent Document 1), since the rear side frame employs a cylindrical member, there is a problem in that the accuracy is lowered if it is bent halfway.
In addition, the bending may cause a decrease in strength or a fold for a rear-end collision load.

Japanese Patent Laid-Open No. 2006-240445

  The present invention makes it easy to ensure the accuracy of the vehicle body without impairing the accuracy of the cylindrical member (extruded material), and increases the strength by keeping the extruded material straight, without compromising the weight reduction. It is an object of the present invention to provide a vehicle body rear structure with improved collision performance.

  In order to solve the above problems, the invention according to claim 1 is arranged between a rear side frame extending from the left and right sides of the passenger compartment to the rear of the vehicle and between the rear side frames, and both ends thereof are coupled to each other. The rear side frame has a light alloy extruded material at the rear part, and the rear part of the rear side frame is formed in a letter shape or eye shape from the center of the rear part, and downward from the center to the remaining front end. The lower part of the U-shaped section of the section U located at is cut into a U-shaped section or a Japanese-shaped section, and the front end is abutted against the cross member.

  The invention according to claim 1 includes a rear side frame and a cross member disposed and coupled between the rear side frames, and the rear side frame has a rear portion made of a light alloy extruded material, and the rear end of the vehicle from the center of the rear portion. Is formed in the shape of a letter in the shape of a cross-section or in the shape of an eye, and by cutting the lower part of the shape of the section U located below from the center to the remaining front end, it is formed in a shape of a cross-section Since the front end is abutted against the cross member, when the rear bumper beam is attached to the lower part, the remaining cross-section B-shaped or day-shaped portions can be mounted in a straight state of extrusion. That is, if the load (impact) input to the rear bumper beam at the time of rear-end collision is small, the load is transmitted to the lower part from the rear bumper beam and received at the lower part. In a stable state, the transmitted load (impact) is transmitted and distributed to the cross member. Therefore, it is easy to ensure the accuracy of the vehicle body without impairing the accuracy of the extruded material, and the strength can be increased by keeping the extruded material straight, and the collision performance is enhanced without impairing the weight reduction. Can do.

It is the perspective view which reversed the vehicle body rear part structure based on the Example of this invention upside down. It is a side 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 the perspective view which turned the rear side frame of the vehicle body rear part structure upside down. It is a back detailed drawing of the rear side frame of a vehicle body rear part structure. It is a figure explaining the manufacture point of the rear part of the rear side frame with which a vehicle body rear part structure is provided. It is a figure explaining the load transmission mechanism at the time of the rear-end collision of the vehicle body rear part structure based on an Example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to examples. 1 and 4 show the vehicle 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 forming a side wall, a right side body (similar to the left side body 22), and a rear body 24 forming 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 portion 44 coupled to the side sill 42 of the left side body 22 and a rear portion 45 connected to the front portion 44. Details will be described later.

As shown in FIGS. 1 to 4, the vehicle body rear structure 11 includes a rear side frame (left rear side frame 27, right side) extending from the left and right sides of the floor (underbody 21) of the passenger compartment 14 toward the rear of the vehicle (in the direction of arrow a <b> 1). Rear side frame 28) and a cross member (second rear cross member 33) disposed between the rear side frames and coupling both end portions (left end portion 51 and right end portion 52) to each other. Yes.
The rear side frame (left rear side frame 27) has a rear portion 45 as a light alloy extruded material (main body 55), and is formed in a cross-sectional shape from the center of the rear portion 45 to the rear end 61 of the vehicle. By cutting the lower part of the U-shaped section located below to the front end 54, it is formed in the shape of a cross-section, and the front end 54 abuts against the cross member (second rear cross member 33).

  The rear side frame (left rear side frame 27) is formed in the shape of a cross section, but it may be in the shape of a cross section, and the cross section can be obtained by cutting the lower portion of the cross section U that is located below. It may be formed in a B shape.

  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 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. 2 and 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.

  The rear bumper beam 37 is attached to the rear end of the lower body 93 (similar to the rear end 85 of the frame main body 84) via the bumper bracket 101.

  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, a shape along the inner surface of the rear portion 45 is formed with a small gap (contactable) with the inner surface. This is an extruded aluminum material. 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 manufacturing procedure of the rear portion 45 of the rear side frame (left rear side frame 27) will be briefly described with reference to FIG. FIG. 6A illustrates an extrusion molding process, and FIG. 6B illustrates a process of manufacturing the main body 55.

  (A): First, a long aluminum extruded material 117 having the same shape (FIG. 5) as the rear portion 45 of the rear side frame (left rear side frame 27) is made. In the extruded material 117, the lower body 93 has the same length as the intermediate body 92. Next, the extruded material 117 is cut into a predetermined length (FIG. 6B).

  (B): The lower body 93 is cut into a predetermined length. Specifically, the main body 55 having the lower body 93 (lower part) is obtained by cutting an unnecessary portion of the lower body 93 from the edge 106 as indicated by an arrow a4.

Next, the operation of the vehicle body rear portion structure 11 according to the embodiment of the present invention will be described.
In the vehicle body rear structure 11, as shown in FIGS. 1 and 4, the rear portion 45 of the rear side frame (left rear side frame 27) is a light alloy extruded material (main body 55). Is formed in the shape of a cross section, and the lower portion of the shape of the cross section U located below from the center to the remaining front end 54 is cut to form a cross-section of the front end 54. Since it abuts against the second rear cross member 33), the dimensional accuracy of the extruded material can be maintained, and the accuracy of the vehicle body 17 can be easily ensured.

  In the rear structure 11 of the vehicle body, when a slight rear collision occurs as shown by an arrow a5 in the rear bumper beam 37 shown in FIG. 7, the rear impact load is transmitted from the lower body 93 (lower part) to the intermediate body 92 as shown by an arrow a6. Since the body 92 transmits the load to the cross member (second rear cross member 33) as indicated by an arrow a7, the intermediate body 92 positioned higher than the rear bumper beam 37 can be provided straight. As a result, compared to the case where the rear side frame is bent, it does not cause folds or load concentration at the bent part, and it improves the collision performance (suppression of deformation by improving the strength against rear-end collision) while reducing the weight. Can do.

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 main body 55 is formed in the shape of a cross section as already described with reference to FIG. 6, but the main body 55 may be in the shape of a cross section, and a lower body 93 (lower portion) having a cross section U shape located below is provided. You may form in the shape of a cross-section by cutting.

  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 ... Car 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), 33 ... Cross member (2nd rear cross member) ), 45: Rear portion of rear side frame, 51: End portion (left end portion), 52: End portion (right end portion), 54: Front end of rear side frame, 61: Rear end of vehicle, 93: Lower portion (lower body) ).

Claims (1)

In the rear structure of the vehicle body comprising a rear side frame extending from the left and right sides of the passenger compartment to the rear of the vehicle, and a cross member disposed between the rear side frames and coupled to both ends.
The rear side frame is formed of a light alloy extruded material at the rear part thereof, and is formed in a shape of a cross-section or an eye shape from the center of the rear part to the rear end of the vehicle, and a cross section positioned downward from the center to the remaining front end A vehicle body rear part structure formed by cutting a U-shaped lower part into a U-shaped section or a day-shaped section and abutting the front end against the cross member.

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