Suspension arm support structure

Abstract

In the present invention: a cross member (2) is installed between a left-right pair of side frames (1) extending in the front-rear direction of a vehicle; a left-right pair of front-rear brackets (3F, 3R) having a front-side connection part (6F) and a rear-side connection part (6R) for connecting arms (4U, 4L) of a suspension are disposed in front and rear of the cross member (2); the front-rear brackets (3F, 3R) are joined and fixed to the side frames (1) and are joined and fixed to the cross member (2) below the side frames (1); and the front-side connection part (6F) and the rear-side connection part (6R) are positioned further inward in the vehicle width direction than the side frames (1).

Description

Suspension arm support structure

[0001] The present invention relates to a suspension support structure that supports a suspension arm.

[0002] In the patent document 1 listed below, the vehicle body side end of a suspension arm is connected to a side frame that extends in the front-rear direction of the vehicle.

[0003] Japanese Patent Application Laid-Open No. 2017-1564

[0004] To ensure vehicle stability, the length of the suspension arm must be increased, and to achieve this, the portion where the vehicle body end of the arm is connected must be located inward in the vehicle width direction. To achieve this with the suspension arm support structure described in Patent Document 1, the side frame must be significantly curved inward in the vehicle width direction at the portion where the vehicle body end of the arm is connected. However, such a significant curvature of the side frame inward in the vehicle width direction may reduce the strength of the side frame itself and the support rigidity that supports the suspension. The present invention aims to provide a suspension arm support structure that can ensure the strength of the side frame and the support rigidity of the suspension.

[0005] One aspect of the present invention is a vehicle comprising a pair of left and right side frames extending in the fore-and-aft direction of the vehicle, a pair of left and right brackets having front and rear connecting portions that connect arms that support the vehicle wheels, and a cross member mounted on the pair of side frames, the cross member being disposed between the front and rear connecting portions, the brackets being connected to the side frames and also to the cross member below the side frames, and the front and rear connecting portions being located inward in the vehicle width direction from the side frames.

[0006] According to one aspect of the present invention, the strength of the side frame can be ensured, and the support rigidity of the bracket that supports the suspension can be ensured. The objects and advantages of the present invention are realized and achieved by using the elements and combinations thereof set forth in the claims. It should be understood that both the foregoing general description and the following detailed description are merely exemplary and explanatory and are not intended to limit the invention as defined by the claims.

[0007] Fig. 2 is a perspective view showing one embodiment of a suspension arm support structure; Fig. 3 is a three-view diagram of the bracket, side frame, and cross member of Fig. 1; Fig. 4 is an explanatory diagram of an example configuration of an arm in the suspension arm support structure of Fig. 1; Fig. 5 is a bottom view of the suspension arm support structure of Fig. 1; Fig. 6 is a rear view of the suspension arm support structure of Fig. 1;

[0008] The suspension arm support structure of the embodiment shown in FIG. 1 is applied to a rear wheel suspension of a vehicle, as an example. A pair of left and right side frames 1 extending in the vehicle's longitudinal direction are arranged on both sides of the vehicle's width. The portions of each side frame 1 where the rear wheel suspension is attached are slightly curved inward in the vehicle width direction. A cross member 2 is installed between the pair of left and right side frames 1 to connect the curved inward portions of the side frames 1 in the vehicle width direction. Both ends of the cross member 2 in the vehicle width direction are primarily connected and fixed to the inner and outer surfaces and undersides of the side frames 1 in the vehicle width direction. A frame cross member 9 is also installed between the pair of side frames 1 at the rear of the cross member 2 and is connected and fixed to the inner and outer surfaces and undersides of the side frames 1 in the vehicle width direction. The side frames 1, cross members 2, and frame cross member 9 are strength members that constitute the so-called chassis.

[0009] A pair of front and rear brackets 3F and 3R are disposed at the cross member 2's fixed connection to the side frames 1 for connecting the rear suspension arms 4U and 4L. While the front and rear brackets 3F and 3R may be integral with each other on the left and right sides of the vehicle, in this example they are disposed at the front and rear of the cross member 2, respectively. The front and rear brackets 3F and 3R are fixedly connected to the side frames 1, and are also fixedly connected to the cross member 2 below the side frames 1. FIG. 2 is a side view and a bottom view showing the arm connectors 6 of the front and rear brackets 3F and 3R in particular. The cylindrical (cylindrical) portions shown in the figure indicate the connectors 6 (bushes) to which the vehicle body ends of the arms 4U and 4L are connected. For example, the front bracket 3F supporting the rear-left wheel suspension shown in Fig. 2 is provided with a front upper coupling part 6FU and a front lower coupling part 6FL, and the rear bracket 3R is provided with a rear upper coupling part 6RU and a rear lower coupling part 6RL. In the rear-left wheel suspension shown in Fig. 1, the front and rear vehicle body ends of the upper A arm 4U are connected to the front upper coupling part 6FU and the rear upper coupling part 6RU of the front and rear brackets 3F, 3R, and the front and rear vehicle body ends of the lower A arm 4L are connected to the front lower coupling part 6FL and the rear lower coupling part 6RL. It is sufficient for the shafts for connecting the vehicle body ends of the suspension arms of each of these arm coupling parts 6 to be located more inward in the vehicle width direction than the side frame 1.

[0010] 2, the arm connecting portions 6 of these front and rear brackets 3F, 3R are provided further inward in the vehicle width direction than the side frames 1. Therefore, compared to a suspension arm support structure in which the vehicle body side ends of the arms are connected to the side frames 1, the lengths of the arms 4U, 4L can be made longer, which reduces changes in the camber angle of the wheels when the wheels bounce, for example, and makes it possible to ensure vehicle stability. The suspension for the left rear wheel in Figure 1 is a traditional double wishbone suspension with upper and lower A-arms 4U and 4L, as shown in Figure 3a. However, with a suspension arm support structure in which a front upper coupling 6FU, a rear upper coupling 6RU, a front lower coupling 6FL, and a rear lower coupling 6RL are provided on front and rear brackets 3F and 3R, it is possible to support any of the following structures: a structure with two I-arms 4U on the upper side of the suspension and one A-arm 4L on the lower side, as shown in Figure 3b; a structure with one A-arm 4U on the upper side of the suspension and two I-arms 4L on the lower side, as shown in Figure 3c; or a structure with two I-arms 4U on the upper side of the suspension and two I-arms 4L on the lower side, as shown in Figure 3d. Note that in recent years, all of these structures have come to be called double wishbone suspensions.

[0011] As described above, the front and rear brackets 3F, 3R are each joined and fixed to the side frame 1 and to the cross member 2 below the side frame 1. That is, because each bracket 3F, 3R is joined and fixed to both the side frame 1 and the cross member 2 at their joints, the front and rear brackets 3F, 3R have excellent support rigidity against input from the wheels. As is clear from the side view of FIG. 2 , the front upper connecting portion 6FU and the rear upper connecting portion 6RU of the front and rear brackets 3F, 3R are disposed in front and behind the cross member 2. In this embodiment, the vehicle body side end of the upper A arm 4U is connected to the front upper connecting portion 6FU and the rear upper connecting portion 6RU with through-bolts that pass through the cross member 2. The lower end (lower surface) of the cross member 2 is located between the front upper connecting portion 6FU and the rear upper connecting portion 6RU and the front lower connecting portion 6FL and the rear lower connecting portion 6RL. Therefore, rigidity is ensured against an upward input from the upper A arm 4U and a downward input from the lower A arm 4L. Due to the arrangement of the rear lower connecting portion 6RL, the lower end of the rear bracket 3R is located lower than the lower end of the front bracket 3F.

[0012] In this embodiment, the lower end of the shock absorber 5 is connected to the lower A arm 4L, and the upper end is directly connected to the upper part of the side frame 1 via the mounting bracket 1a. The front and rear brackets 3F, 3R are connected and fixed to the side frame 1 mainly on the inner side in the vehicle width direction. Generally, the upper end of the shock absorber 5 is connected to the vehicle body rather than the chassis. In contrast, in this embodiment, when viewed from the rear of the vehicle, for example, the shock absorber 5, lower A arm 4L, front and rear brackets 3F, 3R, and side frame 1 form a ring-shaped structure. Therefore, the side frame 1, which is a strength member, can absorb upward input, particularly from the lower A arm 4L, and rigidity against upward input from the wheel is ensured.

[0013] As shown in the bottom view of FIG. 4 and the rear view of FIG. 5, the lower ends of the pair of left and right rear brackets 3R are connected by a connecting reinforcement 7 extending in the vehicle width direction. Therefore, the connecting reinforcement 7 is bridged between the lower rear connecting portions 6RL of the pair of left and right rear brackets 3R. That is, as shown in the side view of FIG. 2, the positions of the lower rear connecting portions 6RL and the connecting reinforcement 7 are substantially aligned in a side view of the vehicle. This ensures sufficient rigidity to support the suspension from the rear against frontal forces acting on the wheels when the vehicle is traveling forward. Furthermore, as is clear from the rear view of FIG. 5, because the connecting reinforcement 7 is positioned downwardly away from the cross member 2, a ring-shaped structure is formed by the cross member 2, the pair of left and right rear brackets 3R, and the connecting reinforcement 7 in a rear view of the vehicle. This ensures sufficient rigidity to support the suspension from the inside in the vehicle width direction against forces acting on the wheels from the side of the vehicle.

[0014] 4, a pair of left and right member members 8 extending rearward of the vehicle are connected and fixed to the connecting reinforcement 7 at a position near the center of the vehicle width direction, and the vehicle rear ends of these member members 8 are connected and fixed to a frame cross member 9. The pair of left and right member members 8 are each disposed equidistantly from the center of the vehicle width direction between both ends of the connecting reinforcement 7 in the vehicle width direction and the center of the vehicle width direction. This structure connects the rear wheel suspension arm support structure, including the annular structure formed by the connecting reinforcement 7, to the frame cross member 9 and supports it from the rear of the vehicle, thereby further improving the suspension support rigidity against inputs acting on the rear wheels from the front of the vehicle.

[0015] Although the suspension arm support structure according to the embodiment has been described above, the present invention is not limited to the configuration described in the above embodiment and various modifications are possible within the scope of the present invention. For example, in the above embodiment, the bracket is divided into a front bracket 3F and a rear bracket 3R. However, as mentioned above, these brackets 3F, 3R may be integral with each other. Also, in the above embodiment, the front bracket 3F is provided with a front upper connecting portion 6FU and a front lower connecting portion 6FL, and the rear bracket 3R is provided with a rear upper connecting portion 6RU and a rear lower connecting portion 6RL. However, for example, in a strut-type suspension, since there is no upper arm, only the front lower connecting portion 6FL connecting the vehicle body end of the lower arm 4L to the front bracket 3F may be provided as the front connecting portion 6F, and only the rear lower connecting portion 6RL may be provided as the rear connecting portion 6R.

[0016] Thus, the suspension arm support structure of this embodiment comprises a pair of left and right side frames 1 extending in the fore-and-aft direction of the vehicle, a pair of left and right front and rear brackets 3F, 3R having front connecting portions 6F and rear connecting portions 6R that connect the suspension arms 4U, 4L, and a cross member 2 mounted on the pair of side frames 1, with the cross member 2 being arranged between the front bracket 3F (front connecting portion 6F) and the rear bracket 3R (rear connecting portion 6R), and the front and rear brackets 3F, 3R being connected and fixed to the side frame 1 and also connected and fixed to the cross member 2 below the side frame 1, with the front connecting portion 6F and rear connecting portion 6R being located further inward in the vehicle width direction than the side frame 1. This allows the length of the arms 4U and 4L to be secured without bending the side frame 1 significantly inward in the vehicle width direction, thereby ensuring the strength of the side frame 1.In addition, the front bracket 3F of the front connecting portion 6F and the rear bracket 3R of the rear connecting portion 6R, to which the vehicle body side ends of the arms 4U and 4L are connected, are fixedly connected to both the side frame 1 and the cross member 2, thereby ensuring the support rigidity of the front and rear brackets 3F and 3R that support the suspension.

[0017] Furthermore, since the front bracket 3F has a front upper connecting portion 6FU and a front lower connecting portion 6FL, and the rear bracket 3R has a rear upper connecting portion 6RU and a rear lower connecting portion 6RL, even if the suspension has upper arms 4U and lower arms 4L, the vehicle body side ends of these arms 4U, 4L can be connected to the respective connecting portions 6 to support the suspension with the front and rear brackets 3F, 3R. Furthermore, as viewed from the side of the vehicle, the lower end of the cross member 2 is located between the front upper connecting portion 6FU and the rear upper connecting portion 6RU and the front lower connecting portion 6FL and the rear lower connecting portion 6RL, thereby ensuring rigidity against upper inputs from the upper arms 4U and lower inputs from the lower arms 4L.

[0018] Furthermore, because the shock absorber 5 is attached to the side frame 1 between the front connecting portion 6F and the rear connecting portion 6R when viewed from the side of the vehicle, the side frame 1, which is a strength member, can receive upward force from the wheels, ensuring rigidity against upward force from the wheels. Furthermore, the rear bracket 3R is provided with a connecting reinforcement portion 7, which is disposed across the left and right rear connecting portions 6R when viewed from the rear of the vehicle. This ensures rigidity to support the suspension from the rear against force from the front acting on the wheels when the vehicle is traveling forward. Furthermore, the connecting reinforcement portion 7 is disposed below and spaced apart from the cross member 2. When viewed from the rear of the vehicle, the cross member 2, the left and right rear brackets 3R, and the connecting reinforcement portion 7 form a ring-shaped structure, ensuring rigidity to support the suspension from the inside in the vehicle width direction against force acting on the wheels from the side of the vehicle.

[0019] The suspension also has a frame cross member 9 that is positioned rearward of the cross member 2 and spans the pair of side frames 1, and the connecting reinforcement 7 has a pair of left and right member members 8 that extend rearward of the vehicle and are connected to the frame cross member 9, with the member members 8 being positioned between both ends of the connecting reinforcement 7 in the vehicle width direction and the center in the vehicle width direction. This further improves the suspension support rigidity against inputs acting on the wheels from the front of the vehicle.

[0020] 1...Side frame, 2...Cross member, 3F...Front bracket (bracket), 3R...Rear bracket (bracket), 4U, 4L...Arm, 5...Shock absorber, 6...(Arm) connecting portion, 7...Connecting reinforcement portion, 8...Member member, 9...Frame cross member

Claims

1. a pair of left and right side frames extending in the front-rear direction of the vehicle; a pair of left and right brackets each having a front connecting portion and a rear connecting portion for connecting arms that support the wheels of the vehicle; a cross member disposed between the pair of side frames, the cross member is provided between the front connecting portion and the rear connecting portion, and a lower end portion of the cross member is located below the side frame, The bracket is connected and fixed to the side frame and is also connected and fixed to the cross member below the side frame, A suspension arm support structure, wherein the front connecting portion and the rear connecting portion are located inward in the vehicle width direction from the side frame.

2. The arm has an upper arm and a lower arm, 2. The suspension arm support structure according to claim 1, wherein the bracket has a pair of front and rear upper connecting portions that connect the upper arms, and a pair of front and rear lower connecting portions that connect the lower arms.

3. 3. The suspension arm support structure according to claim 2, wherein a lower end of the cross member is located between the upper connecting portion and the lower connecting portion when viewed from the side of the vehicle.

4. 2. The suspension arm support structure according to claim 1, wherein a shock absorber is attached to the side frame between the front connecting portion and the rear connecting portion when viewed from the side of the vehicle.

5. a connecting reinforcement portion that connects the pair of brackets, 2. The suspension arm support structure according to claim 1, wherein the connecting reinforcement portion is disposed so as to bridge the left and right rear connecting portions when viewed from the rear of the vehicle.

6. The connecting reinforcement portion is disposed below and spaced apart from the cross member, 6. The suspension arm support structure according to claim 5, wherein the cross member, the bracket, and the connecting reinforcement portion form an annular structure when viewed from the rear of the vehicle.

7. a frame cross member disposed rearward of the cross member and spanning the pair of side frames; a pair of left and right member members that connect the connecting reinforcement portion and the frame cross member; 7. The suspension arm support structure according to claim 5, wherein the member is disposed between both ends of the connecting reinforcement portion in the vehicle width direction and the center in the vehicle width direction.