JP2002145109A - Suspension frame structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve rigidity against deformation mode of a suspension frame caused by load imposed onto a front or rear part and thereby enhance controllability and stability. SOLUTION: A suspension frame body 1 comprises a front cross member 2 and a rear cross member 3, arranged in a longitudinal direction of a vehicle with a predetermined distance therebetween and connecting a pair of side part connecting members 4 located at both right and left side parts of the vehicle in a longitudinal direction of the vehicle. Each of the side part connecting members 4 is formed with an upper plate 5 and a lower plate 6 connected with each other in a manner that a hollow part S is formed inside. A front arm fitting part 9a and a rear arm fitting part 9b of a lower arm 9 for supporting wheels are provided at the front and rear parts of each of the side part connecting members 4, respectively. The front arm fitting part 9a and the rear arm fitting part 9b are arranged at positions correspondent to the positions where the front cross member 2 and the rear cross member 3 are fitted. Connection parts 3a at both ends of the rear cross member 3 are extended into the hollow part S of the side part connection members 4 and connected thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a suspension frame structure for supporting a suspension arm, a stabilizer, an engine mount member, and the like.

[0002]

2. Description of the Related Art In general, a vehicle body structure is roughly classified into a structure with a frame used for a truck and the like and a monocoque structure used for a passenger car and the like. In the monocoque structure, the frame is not provided separately from the body, but a side member or a cross member is incorporated as a part of the body to improve the torsional rigidity. Chassis components are attached directly to the body, but some vehicles are attached to a partial frame, or so-called subframe, before being assembled to the body.

[0003] This sub-frame is usually called a suspension frame because a suspension lower arm is attached to both sides. Hereinafter, the subframes and the like are collectively referred to as a suspension frame. This suspension frame is a suspension lower arm,
A stabilizer and the like are attached to the vehicle body as an assembly part.

FIG. 10 shows a front portion of a vehicle body of an automobile. In an engine room 101 partitioned by a dash panel 100, a suspension frame is provided via a bracket 103 to front side members 102 arranged on both sides of the vehicle body. 104 is provided on the lower surface side of the engine room 101. The suspension frame 104 includes an upper plate, a lower plate, and a lower arm mounting bracket. Front side member 102
Struts 1 for suspending the left and right wheels 105
06 are provided. On both sides of the suspension frame 104, lower suspension arms 107 for supporting wheels 105 are attached.
The suspension lower arm 107 is swingably attached to a lower arm mounting bracket of the suspension frame 104, and is suspended from the vehicle body via a strut 106. Various equipment such as a stabilizer is assembled to the suspension frame 104.

As shown in FIG. 11, the suspension frame 104 generally includes an upper plate 108 and a lower plate 10 formed by pressing a steel plate or the like.
9 is formed by welding or the like. A pair of suspension lower arm mounting portions 104a and 104b are provided on both sides of the suspension frame 104 in the vehicle width direction. A lower arm mounting bracket 110 is provided in a cantilevered state on the suspension lower arm mounting portion 104a on the front side of the vehicle body.

The most severe condition of the suspension frame 104 is when a load in the front-rear direction is applied (in an actual vehicle, for example, when braking or falling into a pothole). As shown in FIG. 11, the deformation mode of the suspension frame 104 at the time of the braking load is such that the mounting portion 104a of the lower arm mounting bracket 110 is opened while being twisted outward as indicated by an arrow.
Is in a mode of sinking downward as indicated by a broken line. Suspension frame 104 Central part 104
The sinking of b also occurs when a load is applied from the engine mount member at the time of sudden start.

On the other hand, as shown in FIG. 12, when a load is applied from the side,
The zero mounting portion 104a is twisted inward as indicated by the arrow. As a result, the lower arm mounting portion 104d on the rear side of the vehicle body of the suspension frame 104 deforms one upward as shown by an arrow and the other downward as shown by an arrow. One is deformed upward as indicated by an arrow and the other is deformed downward as indicated by an arrow, resulting in a wavy mode. As is apparent from the above-described deformation mode, the rigidity around the opening for mounting the lower arm is low when only the upper and lower suspension frames 104 are combined. In the vicinity of the opening,
If there is a vehicle body attachment portion and the rigidity of the suspension frame 104 in this portion is low, the primary natural frequency of the suspension frame 104 may resonate with the vehicle body.

The structure of the suspension frame 104 is as follows.
Various types are known, and FIG. 13 shows a suspension frame 111 of an automobile employing a double wishbone type suspension. The suspension frame 111 is composed of a pair of frames 112 arranged in the front-rear direction on both left and right sides of the vehicle body, and a cross member 113 connecting the frames 112 to each other. The upper plate and the lower plate are joined to each other to form a hollow portion. The left and right frames 112 are provided with lower arm support brackets 114 for supporting the arms of the suspension lower arm 107. At both ends of the cross member 113, upper arm support brackets 116 for supporting the suspension upper arms 115 are provided. I have. In the suspension frame 104, the rigidity of the mounting portion supporting the suspension lower arm 107 is improved by separating the left and right frames 112 into a closed cross-sectional structure.

[0009]

SUMMARY OF THE INVENTION Suspension frame rigidity is an important component in terms of steering stability and NVH performance. In particular, when the front-rear load is input from the tire installation point, the mounting portion supporting the arm of the suspension lower arm 107 is in a deformation mode in which it enters the inside of the vehicle body, and it is important to secure the rigidity of this portion.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a suspension frame structure capable of solving the above-mentioned problems and improving the rigidity of the suspension frame in a deformation mode under a longitudinal load and improving the steering stability.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a front cross member and a rear cross member which are arranged at predetermined intervals in the front-rear direction of the vehicle and are respectively arranged in the vehicle width direction. A suspension frame body is formed by connecting between a pair of side connecting members arranged in the front-rear direction on both sides to form a suspension frame body, and the side connecting members are connected to an upper plate and a lower plate so as to form a hollow portion inside. The front arm mounting portion and the rear arm mounting portion of the lower arm supporting the wheel are provided on the front and rear portions of the pair of side connecting members, respectively, and the front arm mounting portion and the rear arm mounting portion are formed as described above. The front cross member and the rear cross member are arranged corresponding to the mounting positions, and the joints at both ends of the rear cross member are connected to the side portions. Lies in the joint by extending the hollow portion of the timber. Further, according to the present invention, the rear arm mounting portion of the lower arm is provided between the upper plate and the lower plate of the side connecting member, and the joints at both ends of the rear cross member abut against the rear side of the rear arm mounting portion of the lower arm. And joined. Further, the present invention resides in that the joints at both ends of the rear cross member are curved upward in the hollow portion of the side connecting member, and are joined to the upper plate of the side connecting member.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1 and 2 show an embodiment of the suspension frame structure of the present invention applied to an automobile employing a double wishbone type suspension. The suspension frame body 1 includes a pipe-shaped front cross member 2 and a pipe-shaped rear cross member 3 which are arranged in the vehicle width direction at predetermined intervals in the vehicle front-rear direction. It is configured to be connected between a pair of side connection members 4 arranged in the direction. The side connecting member 4
Has an upper plate 5 and a lower plate 6 formed by pressing a steel plate or the like into a hollow portion S (FIG. 3).
) Is formed by welding or the like, and both ends of the front cross member 2 are joined to the inner side surface of the front end of the side connecting member.

The front cross member 2 is provided with a support bracket 8 which raises both ends of a thick pipe upward and supports an upper arm 7 of a suspension in a swingable manner at the end thereof. This front cross member 2
The bracket 10 for supporting the front arm 9a of the lower arm 9 of the suspension is welded to both side curved portions of the suspension. The bracket 11 supporting the rear arm 9b of the lower arm 9 of the suspension is joined between the upper plate 5 and the lower plate 6 in the hollow portion S of the side connecting member 4, as shown in FIGS. Attached. As shown in FIG. 6, the bracket 11 is formed in a U-shape including both side surfaces 11a and a rear surface 11b.
a1, 11a2, and 11a3 are provided, and flanges 11b1 and 11b2 are provided above and below the rear surface 11b. Upper flange 11a1 on both side surfaces 11a of bracket 11
The flange 11a3 at the front end and the flange 11b1 above the rear surface 11b are joined to the inner surface of the upper plate 5. The lower flange 11a2 of both sides 11a of the bracket 11 and the lower flange 11b2 of the rear surface 11b are joined to the inner surface of the lower plate 6 by welding or the like.

On both side surfaces 11a of the bracket 11, mounting holes 12 are formed for supporting a swing shaft of a rear arm 9b of the lower arm 9 of the suspension. To the rear surface 11b of the bracket 11, a distal end portion 3a of the rear cross member 3, which penetrates the side surface of the side connecting member 4 and is introduced into the hollow portion S, is joined. The rear cross member 3
The distal end portion 3a extends through the cylindrical portion 4a formed between the upper plate 5 and the lower plate 6 constituting the side connecting member 4, and extends into the hollow portion S.
Is joined to the rear side of the rear surface 11 b of the bracket 11. The rear cross member 3 includes a cylindrical portion 4a and a bracket 1
1 are joined at two places on the rear surface 11b.

A steering knuckle 13 is mounted on the upper arm 7 and the lower arm 9 of the suspension, and wheels 14 are mounted on the steering knuckle 13. As shown in FIG. 7, the lower arm 9 is equipped with a spring 15 and a shock absorber 16, and a wheel 14 is suspended.

According to the suspension frame structure having the above-described structure, the deformation mode of the suspension frame under the longitudinal load is as shown in FIG. That is, the rear arm 9b mounting portion of the lower arm 9 of the suspension is twisted outward and enters the inside. In addition, the rear cross member 3 is in a mode of expanding upward, and the front cross member 2 is in a mode of lowering downward. At this time, the front end 3a of the rear cross member 3 is
Since the rear arm 11b is joined to the rear side of the rear surface 11b, the rear arm 9b mounting portion of the lower arm 9 of the suspension can be less likely to enter inside while being twisted outward. The displacement can be reduced by up to 30%. In addition, by improving the rigidity (increasing the natural frequency), countermeasures against muffled noise can be achieved. Since the rigidity can be improved in this way, the natural frequency at this time is improved by 11% as compared with the case where the front end portion 3a of the rear cross member 3 is not joined to the rear surface 11b of the bracket 11. By providing the rear cross member 3, the overall rigidity can be improved, and the thickness of the other portions can be reduced, so that measurement can be achieved. Since the front end 3a of the rear cross member 3 is extended and joined into the hollow portion S of the side connecting member 4, the pipe plate is compared with the case where the front end 3a is directly joined to the outer surface of the side connecting member 4. Since the thickness can be changed from 1.6 mm to 1.0 mm, the weight can be reduced by about 25%.

FIG. 9 shows a modification of the present invention.
The distal end portion 3a of the rear cross member 3 is bent upward and joined to the inner surface of an upper plate 5 constituting the side connecting member 4. Also in this case, it is possible to reduce the problem that the rear arm 9b mounting portion of the lower arm 9 of the suspension due to the increased rigidity enters the inside while being twisted outward, similarly to the above embodiment. Therefore,
Steering stability can be achieved.

The present invention is limited to the above embodiment only.
For example, in the present invention, the rear surface 11 of the bracket 11 is
Although the front end 3a of the rear cross member 3 is joined to the bracket 11b, the bracket 11 may have a box shape. etc,
In addition, it goes without saying that the present invention can be carried out with appropriate changes within a scope that does not change the gist of the present invention.

[0019]

As described above, according to the suspension frame structure of the present invention, the following effects can be obtained. 2. A pair of side connection members according to claim 1, wherein a front cross member and a rear cross member arranged in the vehicle width direction at predetermined intervals in the front-rear direction of the vehicle, respectively, are disposed in the front-rear direction on both right and left sides of the vehicle. By connecting between the members, the suspension frame body is configured,
The side connecting member is formed by joining an upper plate and a lower plate so as to form a hollow portion therein, and a front arm mounting portion and a rear arm mounting portion of a lower arm supporting wheels are connected to the pair of side portions. The front arm mounting portion and the rear arm mounting portion are respectively provided on the front and rear portions of the member, and the front arm mounting portion and the rear arm mounting portion are disposed corresponding to the mounting positions of the front cross member and the rear cross member. Since the joint is extended into the hollow portion of the side connecting member, the rigidity in the torsion direction can be increased. By adjusting the thickness of the rear cross member, it is possible to reduce the weight and to improve the braking force, the lateral force, and the rigidity under the load of the engine mount. The increase in rigidity (improvement of natural frequency) can reduce noise. In Claim 2, a rear arm mounting portion of the lower arm is provided between the upper plate and the lower plate of the side connecting member, and a joint at both ends of the rear cross member abuts against a rear side of the rear arm mounting portion of the lower arm. Since they are joined, the rigidity in the torsional direction can be increased. By adjusting the thickness of the rear cross member, it is possible to reduce the weight and to improve the braking force, the lateral force, and the rigidity under the load of the engine mount. The increase in rigidity (improvement of natural frequency) can reduce noise. According to the third aspect, the joints at both ends of the rear cross member are curved upward in the hollow portion of the side connecting member and are joined to the upper plate of the side connecting member by joining, so that the rigidity in the twisting direction is enhanced. be able to. By adjusting the thickness of the rear cross member, it is possible to reduce the weight and to improve the braking force, the lateral force, and the rigidity under the load of the engine mount. The increase in rigidity (improvement of natural frequency) can reduce noise.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a suspension frame structure according to the present invention, viewed obliquely from the front.

FIG. 2 is a perspective view of the suspension frame structure of FIG. 1 viewed from diagonally rear without mounting an upper arm and a lower arm.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a view in the direction of arrow X in FIG. 3;

FIG. 5 is a view in the direction of the arrow Y in FIG. 3;

FIG. 6 is a view as viewed in the direction of the arrow Z in FIG. 2;

FIG. 7 is a perspective view showing a suspension upper arm and a lower arm.

FIG. 8 is a conceptual diagram showing a deformation mode of the suspension frame structure of the present invention.

FIG. 9 is a sectional view showing a modified example of the suspension frame structure of the present invention.

FIG. 10 is a perspective view showing a conventional suspension frame structure.

FIG. 11 is a plan view showing a deformation mode of a conventional suspension frame structure.

FIG. 12 is a plan view showing a deformation mode of a conventional suspension frame structure.

FIG. 13 is a perspective view showing a conventional suspension frame structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Suspension frame main body 2 Front cross member 3 Rear cross member 3a Tip part 4 Side connecting member 4a Tube part 5 Upper plate 6 Lower plate 7 Upper arm 8 Support bracket 9 Lower arm 10, 11 Bracket 11b Rear surface

Claims (3)

[Claims] 1. A front cross member and a rear cross member, which are arranged in the vehicle width direction at predetermined intervals in the front and rear direction of the vehicle, respectively, and a pair of side connection members arranged in the front and rear direction on both right and left sides of the vehicle. A suspension frame body is formed by connecting the members to each other, and the side connecting member is formed by joining an upper plate and a lower plate so as to form a hollow portion therein, and a front of a lower arm supporting a wheel is formed. An arm mounting portion and a rear arm mounting portion are provided on the front and rear portions of the pair of side connection members, respectively, and the front arm mounting portion and the rear arm mounting portion correspond to mounting positions of the front cross member and the rear cross member. The rear cross member is arranged and joined at both ends by extending into the hollow portion of the side connecting member. Suspension frame structure. 2. The rear arm mounting portion of the lower arm,
2. The rear cross member is provided between the upper plate and the lower plate of the side connecting member, and a joint at both ends of the rear cross member is joined to a rear side of a rear arm mounting portion of the lower arm. Suspension frame structure. 3. A joint at both ends of the rear cross member,
The suspension frame structure according to claim 1, wherein the suspension frame structure is curved upward in the hollow portion of the side connection member, and is joined to an upper plate of the side connection member.