JP2022154763A - Sub-frame structure of automobile - Google Patents

Abstract

To provide a sub-frame structure of an automobile capable of reducing the weight of a pivot support part, as well as, allowing a cam bolt to be provided, while securing arm support rigidity of a control arm.SOLUTION: In a sub-frame structure of an automobile according to the present invention, a pivot support portion 36 of a control arm 8 is provided on a rear surface portion 23b of each hanging portion 23 connected to each of left and right lower portions of a rear cross member 22. The pivot support portion 36 includes a bracket 37 having a U-shaped cross section. A bracket side support portion 37e is formed at an end portion on an outer side in a vehicle width direction of a rear surface portion 37c of the bracket 37, and a cross member side support portion 23c is formed at a suspending portion 23 of the rear cross member 22. A cam bolt 39 is inserted through each of the support portions 37e, 23c. In each of an upper surface portion 37a and a lower surface portion 37b of the bracket 37, an opening 37f is formed open outward in the vehicle width direction above and below the bracket side support portion 37e.SELECTED DRAWING: Figure 9

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subframe structure of an automobile, and more particularly, it is configured in a grid shape by a pair of side members extending in the vehicle front-rear direction and front and rear cross members extending in the vehicle width direction so as to connect the pair of side members to each other. The present invention relates to a subframe structure of an automobile.

Conventionally, as a multi-link suspension device, five I-links are provided, and the end of each link on the vehicle body side is connected to a subframe attached to the vehicle body, and the end of each link on the wheel side connects the wheels. It is known to be connected to a supporting wheel support. As a sub-frame for such a multi-link suspension, a frame is known which is formed in a grid pattern by a pair of side members and front and rear cross members (for example, Patent Document 1). Also, a structure is known in which a lower link and a control link are connected to separate suspension support portions (for example, Patent Document 2).

Japanese Patent Application Laid-Open No. 2006-347338 DE 102010030292 A1

In such a five-link suspension, it is effective to make the lower arm and the control arm longer than the other arms in terms of the function of each arm. It is set closer to the center in the vehicle width direction than the left and right ends of the side cross member, and mounting portions for the respective arms are provided at such positions.

Here, since the control arm receives relatively little input from the wheels, it is conceivable to form a pivot support section by providing a bracket on the rear surface of the cross member for supporting the pivot section of the arm end. , such a pivot support must be light in weight while ensuring a predetermined arm support rigidity. In particular, when a cam bolt is used as the pivotal bolt of the control arm to provide a toe angle adjusting function, such a necessity becomes conspicuous.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in order to solve the above-described problems, and is an automobile subframe capable of reducing the weight of a pivot support portion while ensuring arm support rigidity of a control arm and providing a cam bolt. It is intended to provide structure.

In order to solve the above-described problems, the present invention provides a pair of side members extending in the vehicle front-rear direction on both left and right sides in the vehicle width direction, and a front cross member extending in the vehicle width direction so as to connect the pair of side members to each other. and a rear cross member in a parallel cross member, wherein a pair of lower arm pivot support portions are formed at the lower ends of the lower ends of the left and right ends of the rear cross member. The depending parts of the hollow body are connected, and the rear surfaces of the pair of depending parts are respectively provided with pivot supports for the control arm, the pivot supports having a cross section having an upper surface part, a lower surface part and a rear surface part. A U-shaped bracket is welded to the rear surface of the hanging part, and the bracket side support is provided with cam bolts and an eccentric index plate at the end of the rear surface of the bracket on the vehicle width direction outer side. and a cross member side support portion through which the cam bolt is inserted is formed in the hanging portion of the rear cross member at a position facing the bracket side support portion. An opening opening outward in the vehicle width direction is formed above and below the support portion.

According to the present invention configured as described above, one end side of the pivot shaft of the control arm is supported by the rear surface of the bracket and a toe angle adjustment mechanism is provided, and the other end side of the pivot shaft is positioned rearward. Since the hanging portion of the cross member is used for support, the weight of the pivot support portion can be reduced. In addition, since the upper and lower surfaces of the bracket are formed with openings that open in the vehicle width direction, the weight of the bracket can be further reduced. Furthermore, the arm support rigidity can be ensured by the U-shaped cross-sectional bracket and the hanging portion of the rear cross member. Therefore, it is possible to reduce the weight of the pivot support portion and to provide the cam bolt while ensuring the arm support rigidity of the control arm.

Further, in the present invention, the bracket preferably has ribs formed in the vicinity of the bracket-side support portion.
According to the present invention configured in this manner, the bending rigidity of the bracket itself can be increased, and the arm supporting rigidity can be ensured more reliably.

Further, in the present invention, the rear cross member preferably includes a rear cross member main body extending in the vehicle width direction and a pair of hanging portions, and the rear surface portion of the pair of hanging portions is the rear cross member main body. The bracket has an upper edge portion coupled to the rear surface and lower edge portion, and a stepped portion located on the front side of the vehicle from the rear surface of the cross member main body with respect to the upper edge portion. and the stepped portion.
According to the present invention configured as described above, the stepped portion of the hanging portion is located on the vehicle front side from the rear surface of the cross member main body, and the bracket is attached so as to straddle the upper edge portion of the hanging portion and the stepped portion. Therefore, it is possible to secure the accommodation length of the pivot portion and improve the rigidity of the bracket mounting surface.

According to the automobile subframe structure of the present invention, it is possible to reduce the weight of the pivot support portion and to provide the cam bolt while ensuring the arm support rigidity of the control arm.

1 is a perspective view of an automobile rear suspension assembly to which an automobile subframe according to an embodiment of the present invention is applied; FIG. FIG. 2 is a top view of the rear suspension assembly shown in FIG. 1; FIG. 2 is a rear view of the rear suspension assembly shown in FIG. 1; FIG. 2 is a top view of the left rear suspension of the vehicle according to the present embodiment; FIG. 5 is a left side view of the rear suspension of FIG. 4; FIG. 5 is a front view of the rear suspension of FIG. 4; 4 is a partially enlarged rear view similar to FIG. 3, showing the structure of the vehicle left rear cross member in the vehicle subframe according to the present embodiment; FIG. FIG. 8 is a perspective view of the rear cross member shown in FIG. 7 as seen obliquely from the rear of the vehicle; FIG. 2 is a left side view showing the subframe structure on the left side of the vehicle according to the present embodiment; FIG. 10 is a perspective view of the subframe structure on the left side of the vehicle shown in FIG. 9 as viewed obliquely from the front of the vehicle; FIG. 4 is a front view showing a connecting structure of the rear cross member to the side cross member; FIG. 4 is a left side partial cross-sectional view showing a lower arm mounting portion and a control arm mounting portion of the rear cross member according to the present embodiment; FIG. 4 is a perspective view showing the mounting bracket of the control arm according to the present embodiment; FIG. 14 is a perspective view of the mounting bracket of the control arm according to the present embodiment, viewed from an angle different from that of FIG. 13;

Hereinafter, an automobile subframe structure according to an embodiment of the present invention will be described with reference to the accompanying drawings.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.
First, with reference to FIGS. 1 to 3, the overall configuration of the automobile subframe structure according to the embodiment of the present invention will be described. 1 to 3 show an embodiment in which an automotive rear wheel suspension device 1 (hereinafter simply referred to as rear suspension) according to an embodiment of the present invention is applied to both left and right rear wheels of an automobile. 2 is a top view of the rear suspension assembly shown in FIG. 1, and FIG. 3 is a rear suspension assembly shown in FIG. 1. FIG. 4 is a rear view of the suspension assembly; FIG.
Although not shown, the automobile (vehicle) of this embodiment has an engine mounted in the engine room in the front part of the vehicle body, and a differential is arranged in the rear part of the vehicle body so that the rear wheels 2 are driven by the axle (not shown). It is a rear-wheel drive vehicle.
As shown in FIGS. 1 to 3, the rear suspension assembly of the rear wheel suspension device 1 includes a subframe 3 to which a pair of left and right rear suspensions are connected.

First, the schematic configuration of the rear suspension will be described.
The rear suspension of this embodiment is of a multi-link type in which the wheel support 10 of the rear wheel 2 is connected to the vehicle body by five independent I-links 4-8 so as to be able to stroke. The rear suspension device 1 includes a front upper link (upper arm) 4 and a rear leading link (leading arm) 5 that form a virtual upper arm, and a front tray that forms a virtual lower arm. A ring link (trailing arm) 6, a lower link (lower arm) 7 on the rear side, and a toe control link (toe control arm) for regulating the rotational displacement of the rear wheel 2 about the virtual kingpin axis IK (see FIG. 5) ) 8. The upper arm 4, the leading arm 5, the trailing arm 6, and the lower arm 7 swing up and down about the connecting portions (44, 52, 60, 68) on the vehicle body side, respectively, so that the wheel support 10 and the rear wheel 2 are supported. It is designed to stroke up and down along a predetermined trajectory.

Moreover, a shock absorber 16 having a coil spring 12 and a damper 14 is provided to allow such a stroke of the rear wheel 2 and to apply a predetermined biasing force and a damping force at the same time. The shock absorber 16 has a vertically elongated cylindrical shape in which the coil spring 12 and the damper 14 are arranged substantially coaxially, and the upper end thereof is attached to the vehicle body. A lower end portion of the shock absorber 16 is pivotally attached to the lower arm 7 .
A stabilizer bar 18 extending so as to connect the left and right lower arms 7 is rotatably attached to the suspension device 1 .

Next, a schematic configuration of the subframe 3 according to this embodiment will be described.
The sub-frame 3 is mainly formed by combining four steel frames in a rectangular frame shape/parallel cross member shape when viewed from above. 22, and a pair of side cross members (side members) 24, 26 extending in the longitudinal direction of the vehicle body on both left and right sides of the vehicle body so as to connect the left and right ends thereof.

First, the front cross member 20 of the present embodiment is configured as a hollow body having a closed cross section in which upper and lower plate-like members 120 and 220 are joined to each other. The left and right ends/open ends 20a in the width direction are connected to the front end portions of the left and right side cross members 24 and 26, respectively.
As shown in FIGS. 1 and 2, the front cross member 20 is formed in an arch shape that curves as a whole so that its longitudinal central portion is positioned above both left and right end portions when viewed in the vehicle front-rear direction. ing.

As shown in FIG. 2, the front cross member 20 extends linearly at its longitudinal central portion when viewed from above the vehicle, and its front-to-rear length increases toward the left and right ends 20a from the central portion. It is extended to More specifically, when viewed from above, the front edge of the front cross member 20 extends linearly in the vehicle width direction, and the central portion of the rear edge extends linearly in the vehicle width direction. The side portions are curved and extend in the vehicle width direction so as to be located rearward of the central portion.
The portions 20b whose front and rear lengths are enlarged on both left and right sides include open end portions 20a with closed cross sections, and as shown in FIGS. are joined (welded) to each other.

Further, on the left and right end sides of the front cross member 20, positions close to the coupling portions (20a) with the side cross members 24 and 26, respectively, and on the upper side and the lower side of the side cross members 24 and 26, respectively, A mounting seat (pivot shaft support portion) 28 for the upper arm 4 and a mounting seat (pivot shaft support portion) 30 for the trailing arm 6 are provided (see FIGS. 4 to 6). The vehicle body side ends of the upper arms 4 are connected to the mounting seats 28 on the left and right sides, respectively, and the vehicle body side ends of the trailing arms 6 are connected to the mounting seats 30 on the left and right sides, respectively.

Next, the rear cross member 22 of this embodiment consists of a rear cross member main body 21 that constitutes a part of the parallel cross-shaped subframe 3 and left and right rear cross member lower portions (drooping portions) that mainly support the lower arms. As viewed from above the vehicle, left and right end portions/open end portions 22a in the vehicle width direction are coupled to respective front end portions of left and right side cross members 24 and 26, respectively.
The rear cross member main body 21 is configured as a hollow body with a closed cross section in which the front and rear plate-like members 121 and 221 are joined to each other. Enlarged portions 22b are formed on both left and right sides in the width direction of the vehicle, the front and rear lengths of which increase toward each end. The open ends 22a of these enlarged portions 22b are joined (welded) to respective rear end portions of the side cross members 24 and 26, respectively. In this embodiment, such a configuration ensures the rigidity of the rear cross member 22 itself and the subframe 3 .
As shown in FIG. 3, the rear cross member main body 21 is formed in an arch shape that curves as a whole so that the central portion in the longitudinal direction is positioned below the left and right end portions when viewed from the rear of the vehicle. there is

The rear cross member lower portion 23 is configured as a hollow body with a closed cross section in which three plate-like members 123, 124, 223 (see FIG. 5) on the front and rear sides are joined together. The rear cross member lower portion 23 is coupled (welded) to the lower portion of the rear cross member main body 21 at a position inward of and near the side cross members 24 and 26 in the vehicle width direction, and is connected to the side cross members 24 and 26. It extends outward in the vehicle width direction and is joined (welded) to the lower and outer surfaces of the side cross members 24, 26 (see FIGS. 7 to 11).

Mounting seats (pivot shaft support portions) 32 for the leading arm 5 and mounting seats (pivot shaft support portions) for the lower arms 7 are provided on the left and right end sides of the rear cross member 22 on the upper and lower sides of the side cross members 24 and 26, respectively. 34 are provided (see FIGS. 4 and 5). The vehicle body side ends of the leading arms 5 are connected to the left and right mounting seats 32 , and the vehicle body side ends of the lower arms 7 are connected to the left and right mounting seats 34 .
In this embodiment, the lower end portion of the rear cross member lower portion 23 is formed as a mounting seat 34 for the lower arm 7, and the upper end portion of the rear cross member lower portion 23 is formed as a part of the mounting seat 32 for the leading arm 5. are formed (see FIGS. 9 and 10).

Further, on the rear surface 23b of the rear cross member lower portion 23, there are provided positions inward of the side cross members 24 and 26 in the vehicle width direction when viewed from above, and positions of the side cross members 24 and 26 when viewed from the rear. A mounting seat (pivot shaft support portion) 36 for the toe control arm 8 is provided at an obliquely lower position. The ends of the toe control arms 8 on the vehicle body side are connected to the mounting seats 36 on the left and right sides, respectively.

Next, each of the left and right side cross members 24 and 26 is curved so that its central portion in the longitudinal direction is positioned more inward in the vehicle width direction than the front and rear end portions when viewed from above the vehicle. , extending obliquely downward in front of the vehicle from the rear end to the front end (see FIG. 5). The above-described mounting seats 28, 30 are provided on the front side portions of these side cross members 24, 26, and the above-described mounting seats 32, 34 are provided on the rear side portions thereof.

The side cross members 24, 26 are also provided with elastic mounts 38, 40 for elastically supporting the entire subframe 3 on the vehicle body. are provided at a total of four locations on the front and rear ends of the . Each of the elastic mounts 38 and 40 has a cylindrical shape with an axis in the vertical direction and is attached to a recess formed in each of the side cross members 24 and 26 . In each of the side cross members 24, 26, the elastic mounts 38, 40 of the side cross members 24, 26 have a straight line connecting the elastic mount 38 at the front end and the elastic mount 40 at the rear end when viewed from above the vehicle. (shown only in FIG. 2).

Each of the elastic mounts 38 and 40 is formed with a predetermined gap called "chorus". (characteristics indicated by the magnitude of the load (N) causing the load (mm)) are formed to be different. Each of the elastic mounts 38, 40 is attached to the side cross members 24, 26 so as to be oriented such that the stiffness in the vehicle width direction is greater than the stiffness in the vehicle longitudinal direction.

Next, the arrangement configuration of the arms 4 to 8 and the arm support configuration of the subframe 3 of the rear suspension device 1 on the left side of the vehicle will be described with reference to FIGS. 4 to 6. FIG. 4 is a top view of the vehicle left rear suspension according to the present embodiment, FIG. 5 is a left side view of the rear suspension of FIG. 4, and FIG. 6 is a front view of the rear suspension of FIG. Since the rear suspension device 1 on the right side of the vehicle has the same configuration as the rear suspension device 1 on the left side of the vehicle, the description thereof will be omitted below.

First, as shown in FIGS. 4 to 6, the upper arm 4 has a side cross member 24 (26) through an elastic bush (rubber bush, hereinafter referred to as a "bush") 42 at the end on the vehicle body side. ) is connected to the pivotal support 28 of the . When viewed from above the vehicle, the upper arm 4 extends with a rearward inclination so as to be positioned gradually rearward from the connecting portion 44 on the vehicle body side toward the outside in the vehicle width direction. At the wheel-side connecting portion 46 , the wheel-side end portion of the upper arm 4 is connected to the wheel support 10 via a bush 48 .

The pivot shaft support portion 28 of the upper arm 4 is composed of two opposing plate-like members whose base portions are welded to the side cross members 24 and 26. These plate-like members support the pivot portion of the upper arm 4 on the vehicle body side. (see FIGS. 4 to 6).

Next, the leading arm 5 is connected to the above-described pivot shaft support portion 32 via a bush 50 at its end on the vehicle body side. When viewed from above the vehicle, the leading arm 5 extends from a connecting portion 52 on the vehicle body side so as to be positioned gradually forward as it extends outward in the vehicle width direction. At the wheel-side connecting portion 54 , the wheel-side end portion of the leading arm 5 is connected to the wheel support 10 via a bush 56 .

The pivot shaft support portion 32 of the leading arm 5 is composed of two opposing plate-like members, one of which is the upper end portion (plate-like member 124) of the rear cross member lower portion 23 described above in this embodiment, The other is a plate member whose base is welded to the side cross members 24 and 26 (see FIGS. 4 and 5).

Thus, the two upper arms 4 and 5 are arranged so as to approach each other toward the outer side of the vehicle when viewed from above the vehicle.
In this embodiment, pillow ball joints are employed for the bushes 42, 50 on the vehicle body side and the bushes 48, 56 on the wheel side.

Next, the trailing arm 6 is connected at its vehicle-body-side end to the above-described pivot shaft support 30 via a bush 58 . When viewed from above the vehicle, the trailing arm 6 extends so as to be gradually rearwardly positioned from the connecting portion 60 on the vehicle body side toward the outside in the vehicle width direction. At the wheel-side connecting portion 62 , the wheel-side end portion of the trailing arm 6 is connected to the wheel support 10 via a bush 64 .

The pivot shaft support portion 30 of the trailing arm 6 is an arm support bracket 30 having a U-shaped cross-section formed by welding two opposing L-shaped side members to each other. The side pivots are pivoted (see FIGS. 5 and 6).

Next, the lower arm 7 is connected to the above-described pivot shaft support portion 34 via a bush 66 at its vehicle body side end portion. As viewed from above the vehicle, the lower arm 7 extends so as to be inclined forward so as to gradually move forward from the connecting portion 68 on the vehicle body side toward the outside in the vehicle width direction. At the wheel-side connecting portion 70 , the wheel-side end portion of the trailing arm 6 is connected to the wheel support 10 via a bush 72 .

The pivot shaft supporting portion 34 of the lower arm 7 is the lower end portion of the rear cross member lower portion 23 described above, and the pivot portion of the lower arm 7 on the vehicle body side is supported by the front and rear plate-like members 123 and 223 of the lower end portion. (See Figure 5).

In this way, the two lower arms 6 and 7 are arranged so as to approach each other outward in the vehicle width direction when viewed from above the vehicle. When the braking force from the road surface G (see FIG. 3) acts on the rear wheel 2 during braking, etc., toe-in is given geometrically along with the displacement to the rear of the vehicle (longitudinal force compliance steer), and turning. When a lateral force is applied to the rear wheel 2, mainly the bushes 56 and 64 of the lower arms 6 and 7 are bent, so that the rear wheel 2 changes in the toe-in direction (lateral force compliance). steer).
In this embodiment, pillow ball joints are employed for the bushes 58, 66 on the vehicle body side and the bushes 64, 72 on the wheel side.

Next, the end of the toe control arm 8 on the vehicle body side is connected to the above-described pivot shaft support portion 36 via a bush 74 . When viewed from above the vehicle, the toe control arm 8 extends so as to be inclined forward so as to gradually move forward from the connecting portion 76 on the vehicle body side toward the outside in the vehicle width direction. At the wheel-side connecting portion 78 , the wheel-side end of the trailing arm 6 is connected to the wheel support 10 via a bush 80 .
In this embodiment, a pillow ball joint is used for the bushing 74 on the vehicle body side and the bushing 80 on the wheel side.

The pivot shaft support portion 36 of the toe control arm 8 has an arm support bracket 37 integrally formed by press molding and having a U-shaped cross section. The pivot shaft support portion 36 is composed of a shaft support portion of the arm support bracket 37 and a shaft support portion on the side of the rear cross member lower portion 23 formed at positions facing each other in the front-rear direction. A pivot portion of the control arm 8 on the vehicle body side is pivotally supported by the supporting portion (see FIGS. 3 and 5).

Here, in the rear suspension, the intersection of the imaginary extension line of the upper arm 4 and the imaginary extension line of the leading arm 5 and the intersection point of the imaginary extension line of the trailing arm 6 and the imaginary extension line of the lower arm 7 are vertically connected. A virtual kingpin axis IK (see FIG. 5) is formed. This imaginary kingpin axis is the instantaneous center of rotation of the rear wheel 2 in the steering direction (toe direction).

Next, the configuration of the wheel support 10 and the mounting configuration of each arm will be described with reference to FIGS. 4 to 6. FIG.
First, as shown in FIGS. 4 to 6, the wheel support 10 has a hub 82 attached at its center and an opening 84 through which an axle (not shown) passes.
Further, the wheel support 10 is formed with a front vertical wall portion 86 projecting inward in the vehicle width direction from the opening 84 on the vehicle front side. and trailing arm 6 are connected. As shown in FIG. 6, the outer edge of the front vertical wall portion 86 is formed with a reinforcing rib 86a.
A lower vertical wall portion 88 is formed in the wheel support 10 below the opening 84 and projects inward in the vehicle width direction.
Further, the wheel support 10 is formed with a rear vertical wall portion 90 projecting inward in the vehicle width direction at a portion on the vehicle rear side of the opening 84 (a portion on the vehicle rear side of the axle). A toe control arm 8 is connected to 90 .

Next, the connecting structure of the rear cross member 22 to the side cross members 24, 26 will be described with reference to FIGS. 7 to 12. FIG. FIG. 7 is a partially enlarged rear view similar to FIG. 3 showing the structure of the vehicle left rear cross member in the vehicle subframe according to the present embodiment, and FIG. 8 shows the rear cross member shown in FIG. 9 is a left side view showing the vehicle left subframe structure according to the present embodiment, and FIG. 10 is a vehicle oblique view of the vehicle left subframe structure shown in FIG. FIG. 11 is a front view showing a structure for connecting a rear cross member to a side cross member; It is a left side partial sectional view showing a part.
First, as shown in FIGS. 7 and 11 , rear cross member lower portions 23 are provided on the lower left and right sides of the rear cross member main body 21 .
As shown in FIGS. 10 and 11, the rear cross member lower portion 23 mainly includes a first plate-like member (first front member) 123 on the front and lower side and a second plate-like member (first front member) 123 on the front and upper side. and a plate member (second front member) 124 on the rear side (rear member) 223 as shown in FIGS.

First, the configuration of the rear member 223 of the rear cross member lower portion 23 will be described with reference to FIGS. 7 to 9. FIG.
The rear member 223 includes an upper edge portion 23d coupled to the lower edge portion of the rear surface 21a of the rear cross member main body 21, and a front side of the rear cross member main body 21 with respect to the upper edge portion 23d. A stepped portion 23e (especially see FIG. 9) is formed. An upper edge portion 23d of the rear side member 223 is welded to the rear surface 21a of the rear cross member main body 21 along a welding line indicated by symbol W in the drawing. 7 to 9, a pivot shaft support portion 34 for the lower arm 7 is provided at the lower end portion of the rear member 223, that is, below the stepped portion 23e.

As shown in FIGS. 7 to 9, the pivot shaft support portion 36 of the toe control arm 8 is provided on the rear surface of the rear member 223 (the rear surface 23b of the rear cross member lower portion 23). The pivot shaft support portion 36 includes an arm support bracket 37 having a U-shaped cross section, and the arm support bracket 37 has an upper surface portion 37a, a lower surface portion 37b and a rear surface portion 37c, and a base portion 37d thereof extends from the rear member. 223 is joined (welded) to the rear surface 23b. In the present embodiment, the upper surface portion 37a is formed so as to be positioned higher toward the outer side in the vehicle width direction, and the lower surface portion 37b is formed so as to extend substantially in the horizontal direction. It is formed in a triangular shape when viewed from the rear so that the length in the vertical direction expands outward.

As shown in FIGS. 7 and 8, the bracket 37 is welded to the rear surface 23b of the rear member 223 at a weld line W along the base portion 37d of the upper surface portion 37a and the base portion 37d of the lower surface portion 37b. The bracket 37 is welded to the rear member 223 by these welding lines W so as to straddle the upper edge portion 23d and the step portion 23e of the rear cross member lower portion 23. As shown in FIG.

Next, one shaft supporting portion (bracket side shaft supporting portion) 37e of the pivot portion is formed at the outer end portion of the rear surface portion 37c of the arm support bracket 37 in the vehicle width direction. On the other hand, as particularly shown in FIG. 9, at a position facing the front side of the shaft support portion 37e, the other shaft support portion (cross member side shaft support portion) of the pivot portion is provided in the above-described stepped portion 23e of the rear member 223. 23c (see FIGS. 9 and 12) are formed, and a pivot portion including a pivot bolt 39 on the vehicle body side of the control arm 8 is pivotally supported by the two opposing pivot portions 37e and 23c.
Further, as particularly shown in FIG. 12, in this embodiment, the toe control arm 8 is provided with a function of adjusting the toe angle of the rear wheel 2 by using the pivot bolt 39 of the toe control arm 8 as a cam bolt. For this reason, the shaft support portion 37e of the arm support bracket 37 is formed with a hole through which the cam bolt 39 is inserted, and an eccentricity index plate 41 having a scale indicating the degree of eccentricity (the degree of adjustment of the toe angle). (see FIG. 8) is attached.

Next, the upper surface portion 37a and the lower surface portion 37b of the arm support bracket 37 are formed with an opening portion 37f that opens outward in the vehicle width direction above and below the shaft support portion 37e. A rib 37g is formed in the vicinity of .

Next, the configuration of the front side members 123 and 124 of the rear cross member lower portion 23 will be described with reference to FIGS. 9 to 11. FIG.
First, as shown in FIGS. 9 to 11, the rear cross member lower portion 23 has a first front member 123 on the front and lower side and a second front member 124 on the front and upper side. .
The first front side member 123 is formed so as to extend outward in the vehicle width direction from a connecting portion 23a to the lower portion of the rear cross member main body 21 and wrap around from the lower side of the side cross member 24 (26) to the outer side surface side. there is

An opening 23f is formed in the upper edge of the first front member 123 so that the operator can access the cam bolt 39 for adjusting the toe angle. That is, in this embodiment, as shown in FIG. 11, the cam bolt 39 is provided inside the opening 23f when viewed from the front of the vehicle.

Next, the first front side member 123 is welded from the lower surface to the side surface of the side cross member 24 (26) at the upper edge portion outside the opening 23f in the vehicle width direction (see welding line W). Further, the first front member 123 has its vehicle width direction inner upper edge portion welded to the lower portion of the rear cross member main body 21 (see welding line W), and its vehicle width direction outer edge portion It is welded to the outer edge in the vehicle width direction of the rear member 223 described above (see weld line W).

Next, the second front member 124 provided above is configured as an extension portion that extends the first front member 123 to the upper side of the outer surface of the side cross member 24 (26), and also serves as an attachment point for the leading arm 5 described above. The seat 32 constitutes one of opposed plate-like members that support the pivot shaft.

The second front member 124 is welded at its outer edge in the vehicle width direction to the outer edge in the vehicle width direction of the rear member 223 (see weld line W). Further, the second front member 124 is welded to the side surface and top surface of the side cross member 24 (26) so as to ensure arm support rigidity of the mounting seat 32 described above (see weld line W). Furthermore, the lower edge of the second front member 124 is welded to the outer edge in the vehicle width direction of the first front member 123 (see weld line W).

Next, as shown in FIGS. 8 and 10, the rear cross member lower portion 23 composed of the front members 123, 124 and the rear member 223 configured as described above has a front-to-rear length of The longitudinal length of the cross member main body 21 is formed so as to be smaller than that of the longitudinal length of the enlarged portion (joint portion to the side cross member 24 (26) at both left and right ends) 22b.

Next, as shown in FIGS. 13 and 14, the arm support bracket 37 is formed by press-molding a plate-shaped steel plate member, and includes the upper surface portion 37a, the lower surface portion 37b, the rear surface portion 37c, the base portion 37d, and the shaft. It has a support portion 37e, and the bracket 37 is formed with an opening 37f and ribs 37g.

Next, the effects of this embodiment will be described.
According to the present embodiment, a pair of hollow hanging portions (rear cross member lower portions) 23 in which pivot support portions 34 of the lower arm 7 are formed at the lower end portions of the rear cross member 22 on the left and right end sides thereof. are connected to each other, and the pivot support portions 36 of the control arm 8 are provided on the rear surface portions 23b of the pair of hanging portions 23, respectively. is welded to the rear surface portion 23b of the drooping portion 23, and a cam bolt 39 is inserted through the end portion of the rear surface portion 37c of the bracket 37 on the outer side in the vehicle width direction, and an eccentric A bracket-side support portion 37c provided with an index plate 41 is formed, and a cross-member-side support portion 23c through which a cam bolt 39 is inserted is formed in the drooping portion 23 of the rear cross member 22 at a position facing the bracket-side support portion 37c. An upper surface portion 37a and a lower surface portion 37b of the bracket 37 are formed with openings 37f that open outward in the vehicle width direction above and below the bracket side support portion 37e.
According to this embodiment constructed as described above, one end of the pivot shaft of the control arm 8 is supported by the rear surface of the bracket 37, and the toe angle adjustment mechanism (cam bolt 3) is provided. Since the other end side is supported using the drooping portion 23 of the rear cross member 22, the weight of the pivot support portion 36 can be reduced. Further, since the upper surface portion 37a and the lower surface portion 37b of the bracket 37 are formed with an opening portion 37f that opens in the vehicle width direction, it is possible to further reduce the weight. Further, arm support rigidity can be ensured by the U-shaped cross-sectional bracket 37 and the hanging portion 23 of the rear cross member. Therefore, it is possible to reduce the weight of the pivot support portion and to provide the cam bolt while ensuring the arm support rigidity of the control arm.

In addition, in the present embodiment, the rib 37g is formed on the bracket 37 in the vicinity of the bracket-side support portion 37e, so that the bending rigidity of the bracket itself can be increased, and the arm support rigidity can be ensured more reliably. can.

In this embodiment, the rear cross member 22 includes a rear cross member main body 21 extending in the vehicle width direction, and a pair of hanging portions (rear cross member lower portions) 23. Rear surface portions 23b of the pair of hanging portions 23 an upper edge portion 23d coupled to the lower edge of the rear surface 21a of the rear cross member main body 21; The bracket 37 is attached to the hanging portion 23 so as to straddle the upper edge portion 23d of the hanging portion 23 and the stepped portion 23e. According to such a configuration, the stepped portion 23e of the drooping portion 23 is located on the vehicle front side of the rear surface 21a of the rear cross member main body 21, and the bracket 37 is positioned between the upper edge portion 23d of the drooping portion 23 and the stepped portion 23e. Since it is attached so as to straddle the toe control arm 8, it is possible to secure the accommodation length of the pivot portion (the pivot portion including the bush 74 attached to the connecting portion 76 of the toe control arm 8) and improve the rigidity of the bracket mounting surface. can be done.

1 Automobile Suspension Device/Rear Suspension Assembly 2 Rear Wheel 3 Subframe 4 Upper Arm 5 Leading Arm 6 Trailing Arm 7 Lower Arm 8 Toe Control Arm (Control Arm)
10 wheel support 16 shock absorber 18 stabilizer bar (stabilizer link)
20 Front cross member 21 Rear cross member main body 21a Rear surface 22 Rear cross member 22a Both ends/left and right open ends 22b Enlarged portion 23 Rear cross member lower portion 23a Joint portion 23b Rear surface 23c Cross member side shaft support portion 23d Upper edge portion 23e Stepped portion 23f Front openings 24, 26 of rear cross member lower portion 23 Side cross member (side member)
32 Pivot support for leading arm 5 (pivot support)
34 lower arm 7 pivot shaft support (pivot support)
37 Support brackets 37a, 37b, 37c of the toe control arm 8 Top, bottom, rear surface 37d Base 37e Bracket-side pivot 37f Opening 37g Rib 39 Pivot/cam bolt 41 Eccentric index plate 123 Lower front side of rear cross member Plate-shaped member (first front member) of
124 Plate-shaped member (second front member) on the front side upper side of the rear cross member
223 Plate-like member on the rear side of the rear cross member (rear member)
IK Virtual kingpin axis W Weld line (weld line)

Claims (3)

A pair of side members extending in the longitudinal direction of the vehicle on both left and right sides in the vehicle width direction, and a front cross member and a rear cross member extending in the vehicle width direction so as to connect the pair of side members to each other form a parallel cross member. A subframe structure for an automobile,
A pair of hollow hanging parts having pivot support parts for lower arms formed at their lower ends are coupled to the lower parts of the left and right ends of the rear cross member,
A pivot support for the control arm is provided on each of the rear surfaces of the pair of hanging parts, and these pivot supports hang the U-shaped bracket having an upper surface, a lower surface, and a rear surface. It is configured by welding to the rear part of the part,
A bracket-side support portion through which a cam bolt is inserted and provided with an eccentricity index plate is formed at the end portion of the rear surface portion of the bracket on the outer side in the vehicle width direction. A cross-member-side support portion through which the cam bolt is inserted is formed in the hanging portion of the rear-side cross member,
A subframe structure for an automobile, wherein the upper and lower surfaces of the bracket are formed with openings that open outward in the vehicle width direction above and below the bracket-side support portion, respectively. 2. The automobile subframe structure according to claim 1, wherein said bracket has a rib formed in the vicinity of said bracket-side support portion. The rear cross member includes a rear cross member main body extending in the vehicle width direction and the pair of hanging portions,
The rear surface portion of the pair of hanging portions includes an upper edge portion coupled to the rear surface and lower edge portion of the rear cross member main body, and the upper edge portion to the front side of the vehicle from the rear surface of the cross member main body. and a stepped portion located at the
3. The vehicle subframe structure according to claim 1, wherein said bracket is attached to said hanging portion so as to straddle an upper edge portion and a stepped portion of said hanging portion.

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