JP3919054B2 - Car suspension frame structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automobile suspension frame structure, and more particularly to an automobile suspension frame structure that can reduce vibration generated in the suspension frame.
[0002]
[Prior art]
FIG. 12 shows a conventional suspension frame structure of an automobile. In FIG. 12, reference numeral 30 denotes a suspension frame attached to the vehicle body, and reference numeral 31 denotes a suspension lower arm attached to both sides of the suspension frame 30 so as to be rotatable. , 32 are front wheels rotatably connected to these suspension lower arms 31 via knuckles 33, respectively.
[0003]
The above-described suspension frame 30 is an automobile part to which a suspension lower arm 31, a stabilizer (not shown), and the like are attached, and both sides thereof are attached to the vehicle body. The basic structure of the suspension frame 30 includes a frame main body portion 36 in which an upper plate 34 and a lower plate 35 (see FIG. 13) are superposed on each other and joined in a closed cross-sectional shape by spot welding or the like, and the frame main body portion. 36, and a pair of suspension lower arm mounting brackets 37a respectively attached to the left and right ends of the vehicle 36 and at the front end of the vehicle body.
[0004]
The suspension frame 30 is basically attached to both sides of the suspension frame 30 as described above, and an engine or the like is attached to the central portion of the suspension frame 30 via an engine mount member. Note that both sides of the suspension frame 30 are normally attached to the vehicle body by so-called six-point support. That is, the left and right side portions of the suspension frame 30 are respectively provided at three locations using three attachment holes 38a, 38b, and 38c (see FIGS. 12 to 14) provided on the side edge portions of the suspension frame 30. It is fixed to the vehicle body by tightening and fixing (three-point support).
[0005]
More specifically, the suspension frame 30 is provided with mounting holes 38a at both left and right ends of the rear side thereof, and mounting holes 38b are provided closer to the center in the width direction and closer to the front than the mounting holes 38a. An attachment hole 38c is provided in a region between the attachment hole 38a and the attachment hole 38b in the vehicle width direction and closer to the front side than the attachment hole 38b. Thus, the suspension frame 30 is fixedly supported on the vehicle body side by bolting with these attachment holes 38a, 38b, 38c as attachment points.
[0006]
[Problems to be solved by the invention]
By the way, the problem with this type of suspension frame 30 is that it generates vibration noise. That is, there is a problem that if the rigidity of the central portion of the suspension frame 30 and the both side portions which are the vehicle body attachment portions are low, a “boom noise” is generated due to resonance with the vehicle body, resulting in vibration noise.
[0007]
In the conventional suspension frame structure as described above, both sides of the suspension frame 30 are attached to the vehicle body with three-point support, but actually the tightening strength (support strength) at the three-point support portion is In reality, it is not uniform, and the fastening strength of the suspension frame 30 at the innermost mounting hole 38b is weakened. Therefore, the primary vibration mode of the suspension frame 30 supported at six points on the vehicle body is a mode in which the portion between the left and right side portions of the suspension frame 30 between the vehicle body side mounting portions is deformed in a wave shape in the vertical direction (see FIG. 8) In this case, the straight line L ₁ connecting the outer attachment points α and β in FIG. 14 becomes the vibration restraint line. Further, the strain energy increases at the vehicle body side attachment portion (vehicle body support portion) at the two inner points (γ points in FIG. 14) of the three attachment points.
[0008]
Therefore, in order to solve such problems, the rigidity is increased by measures such as increasing the thickness of the inner two points (gamma point), applying patches, and adding reinforcements. However, in this case, the weight increases as the plate thickness increases, and the weight and the number of parts increase as the patch and lean reinforcement are provided. This causes a malfunction. Further, when the suspension frame 30 itself cannot cope with it, it is conceivable to take a countermeasure for attaching a damper. In this case, the weight increases and the number of parts increases corresponding to the damper.
[0009]
The present invention has been made in view of such a situation, and the object thereof is to increase the plate thickness of the suspension frame on the vehicle body side, or to provide other parts such as a patch for improving rigidity, a reinforcement, etc. To provide a suspension frame structure for an automobile that can reduce the vibration of the suspension frame without using a damper for damping vibrations and can reduce the weight of the suspension frame and the number of parts. is there.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, in a suspension frame structure for an automobile, suspension frames for suspending wheels are arranged along the vehicle width direction, and both left and right ends of the suspension frame are attached to a vehicle body. The suspension frame is formed in a closed cross-sectional shape by superimposing an upper plate and a lower plate on top and bottom, and both side portions of the suspension frame are fixed to the vehicle body by fastening and fixing at three locations, respectively . wherein the suspension frame, on the upper surface of the attachment points in the innermost and an in vehicle longitudinal direction of the intermediate position in a fixed position tightening the both side portions, so that providing the bi over de extending substantially along the vehicle width direction .
Also, in the present invention, the bead for reinforcement is formed so as to extend substantially along the longitudinal direction of the vehicle body at the lower surface of the attachment points of the suspension frame.
Also, in the present invention, to form the bi over de so as to protrude inward of the closed cross section portion.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0012]
FIG. 1 shows a configuration of a front part of a vehicle body having a suspension frame structure according to an embodiment of the present invention. As shown in FIG. 1, the suspension frame 1 is disposed so as to extend in the vehicle width direction, and is attached to a pair of left and right apron side members 2a and 2b in a erected state between lower ends. In FIG. 1, reference numeral 3 denotes a cross member laid between the front end portions of the apron side members 2a and 2b, and reference numerals 4a and 4b denote a pair of left and right front fender aprons respectively disposed outside the apron side members 2a and 2b. Reference numeral 5 denotes a dash panel.
[0013]
The above-described suspension frame 1 is an overall U-shaped member (vehicle body part) formed by joining the upper plate 1a shown in FIG. 2 and the lower plate 1b shown in FIG. The left and right side portions on the rear end side of the suspension frame 1 are attached to the apron side members 2a and 2b by three-point support as in the conventional case. As shown in FIG. 2, a suspension lower arm 6 is rotatably attached to a rear end R ₁ on the rear side of the suspension frame 1 and a front end R ₂ on the side of the suspension frame 1, and the suspension lower arm An outer end of the vehicle body 6 is rotatably attached to a knuckle (not shown) of the front wheel.
[0014]
Next, the configuration of the suspension frame 1 and the attachment structure to the apron side members 2a and 2b will be described in detail as follows. First, as shown in FIG. 3, mounting holes 7a, 7b, and 7c are respectively provided at the right and left portions of the upper plate 1a constituting the upper surface portion of the suspension frame 1 at three locations corresponding to the apexes of appropriate triangles. ing. Furthermore, a pair of left and right positioning holes 8 for positioning the suspension frame 1 are provided at appropriate locations on the upper plate 1a. On the other hand, as shown in FIG. 6, the left and right portions of the lower plate 1b constituting the lower surface portion of the suspension frame 1 are provided with mounting holes 9a at three locations corresponding to the mounting holes 7a, 7b, 7c of the above-described upper plate 1a. , 9b, 9c are provided. Thus, using the mounting holes 7a to 7c and 9a to 9c, the left and right side portions of the suspension frame 1 are supported at three mounting points α, β, and γ, respectively. 2, 3, and 6, reference numeral 10 denotes an engine mount member mounting hole.
[0015]
In addition, the suspension frame 1 of the present embodiment is provided with beads 11a, 11b, and 11c that are effective in reducing vibrations in the primary vibration mode at the vehicle body mounting locations of the upper plate 1a and the lower plate 1b, respectively (see FIG. 2 to FIG. 5). More specifically, the upper plate 1a is provided with three reinforcing beads 11a to 11c extending in parallel with each other along the left-right direction (substantially the vehicle width direction) by bending. Specifically, among the three mounting holes 7a, 7b, 7c, a straight line (straight line in the vehicle width direction) that is the position where the innermost mounting hole 7b is disposed and connects the left and right mounting holes 7b, 7b to each other. with one reinforcing bead 11a extending along the top of L ₂ it is provided by bending molding, two reinforcing extending parallel with each other at a position spaced a predetermined distance in the longitudinal direction of the vehicle body from the reinforcing bead 11a The beads 11b and 11c are provided by bending. The reinforcing bead 11a is interrupted at the location where the mounting hole 7b is formed. Further, as shown in FIGS. 4 and 5, these three beads 11 a, 11 b, and 11 c are bent so as to protrude inward of the closed cross-sectional shape portion 13 of the suspension frame 1.
[0016]
On the other hand, the lower plate 1b is provided with two reinforcing beads 12a and 12b extending substantially in parallel with each other along the longitudinal direction of the vehicle body (see FIGS. 6 and 7). Specifically, three mounting holes 9a, 9b, two inner mounting holes 9b, 9c and extends substantially along a straight line the line L ₃ substantially longitudinal direction of the vehicle body connecting together two reinforcing beads 12a of 9c, 12b is bent. The innermost mounting hole 9b is provided on a part of the location where the reinforcing bead 12a is provided. Further, as shown in FIG. 7, these two beads 12 a and 12 b are bent so as to protrude inward of the closed cross-sectional shape portion 13 of the suspension frame 1.
[0017]
According to the suspension frame structure having such a configuration, the reinforcing bead 11a extends in the vehicle width direction in the vicinity of the innermost attachment point β (see FIG. 2) where the distortion energy is greatest at the vehicle body side attachment portion of the suspension frame 1. ˜11c are provided on the upper plate 1a, so that the primary vibration mode of the suspension frame 1 as shown in FIG. 8 (vibration mode in which a straight line connecting the attachment points α and γ in FIG. ) Can be kept small. Furthermore, reinforcing beads 12a extending substantially straight line L ₃ substantially longitudinal direction of the vehicle body connecting the the attachment point beta gamma along. Thus provided 12b to the lower plate 1b, 2 vibration mode of the suspension frame 1 ( As shown in FIG. 10, the amplitude in the vertical deformation of the front and rear ends of the suspension frame 1 centered on the vehicle body side attachment portions on both the left and right sides of the suspension frame 1 can be suppressed small. Further, since the extending direction of the reinforcing beads 12a and 12b is substantially the vehicle body front-rear direction, this bead extending direction is also used for braking the suspension frame 1 and for increasing rigidity when a lateral force acts on the suspension frame 1. It is effective.
[0018]
If the reinforcing beads 12a and 12b of the lower plate 1b are formed so as to extend in the vehicle width direction in the same manner as the reinforcing beads 11a to 11c of the upper plate 1a, it is effective for reducing the vibration in the primary vibration mode. The vibration reduction effect with respect to the secondary vibration mode is reduced. However, since the most important thing in reducing the vibration of the suspension frame 1 is to reduce the amplitude in the primary vibration mode, when the vibration reduction measures for the secondary vibration mode are not so important, the reinforcing beads 11a to 11c and the reinforcing beads are used. All of the beads 12a and 12b for use may be formed so as to extend along the vehicle width direction to further improve the vibration reduction effect in the primary vibration mode.
[0019]
FIG. 11 shows a suspension frame structure as a reference example of the present invention. In this example , three reinforcing beads 11a, 11b, 11c extending in a direction inclined with respect to the vehicle width direction (left-right direction) are provided on the upper plate 1a constituting the upper surface portion of the suspension frame 1 by bending. ing. Specifically, as shown in FIG. 11, the suspension frame 1 is attached to the apron side member 2 (vehicle body), that is, in the vicinity of the innermost attachment hole 7b with respect to the vehicle width direction (straight line L ₂ ). reinforcing bead 11a~11c extending in a direction substantially perpendicular to the substantially vehicle longitudinal direction of the linear line L ₃ connecting the inclined vital attachment points β and γ Te is provided by tough molding. On the other hand, no reinforcing bead is provided on the lower plate 1b constituting the lower surface portion of the suspension frame 1.
[0020]
According to the suspension frame structure configured as described above, the presence of the reinforcing beads 11a to 11c arranged as described above exhibits a vibration reduction effect in both the primary vibration mode and the secondary vibration mode. Can do. Therefore, only by providing the reinforcing beads 11a to 11c on the upper panel 1a, it is not necessary to provide the reinforcing beads on the lower plate 1b, so that the suspension frame 1 can be easily manufactured and the manufacturing cost can be reduced. . In this case, by appropriately selecting the degree of inclination of the reinforcing beads 11a to 11c, the degree of the primary vibration mode reduction effect and the degree of the secondary vibration mode reduction effect can be appropriately adjusted. Is possible.
[0021]
Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications and changes can be made based on the technical idea of the present invention. For example, three reinforcement beads 11a~11c and two reinforcing beads 12a in the implementation form described above has been to 12b set Keru as a number of the reinforcing bead, the shape and dimensions (length and The depth) and the like can be changed as appropriate, and the natural frequency of the suspension frame 1 can be adjusted by appropriately selecting them.
[0023]
【The invention's effect】
The present invention described in claim 1, as well as arranged along the suspension frame for suspending a wheel in the vehicle width direction, in the vehicle suspension frame structure so as to attach the left and right end portions to the vehicle body of the suspension frame, the suspension frame The upper plate and the lower plate are overlapped on top and bottom to form a closed cross-sectional shape, and both sides of the suspension frame are fixed to the vehicle body by tightening and fixing at three locations , and each side of the suspension frame to the vehicle body a innermost fixed position fastening parts on the upper surface of the mounting portion in the vehicle longitudinal direction of the intermediate position, since it is those acceptable to provide a bi over de extending substantially along the vehicle width direction, the suspension frame Just by bending the bead on the plate, it increases the weight and the number of parts. Without causing, it is possible to reduce the vibration of the first vibration mode. Therefore, there is no need to increase the plate thickness of the suspension frame on the vehicle body side as in the past, or to attach reinforcing parts such as patches and reinforcements to the vehicle body side attachment portion of the suspension frame. It is possible to reduce the weight of the frame and reduce the number of parts.
[0025]
According to the second aspect of the present invention, since the reinforcing bead is formed so as to extend substantially along the longitudinal direction of the vehicle body at the lower surface portion of the attachment portion of the suspension frame, the reinforcing bead extends along the longitudinal direction of the vehicle body. The presence of the bead can effectively reduce the vibration in the secondary vibration mode. Furthermore, it is possible to suppress the reduction of the secondary vibration suppressing effect due to the provision of the vehicle width direction of the bi-over de such as described above (first vibration reducing bead) in the longitudinal direction of the vehicle body reinforcing bead above It is possible to adjust the primary and secondary vibration reduction effects between each other.
[0026]
The present invention of claim 3, since it is obtained by forming so as to project a bi over de inwardly of closed cross section portion, the engine mount protrudes outwardly bi over de from the outer surface of the suspension frame Problems such as interference with other parts such as members can be avoided.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a configuration of a front part of a vehicle body having a suspension frame structure according to a first embodiment of the present invention.
FIG. 2 is a plan view showing a state in which a suspension lower arm is attached to a suspension frame.
FIG. 3 is a plan view of an upper frame of a suspension frame.
4 is an enlarged sectional view taken along line AA in FIG. 2. FIG.
5 is an enlarged sectional view taken along line BB in FIG.
FIG. 6 is a plan view of a lower frame of the suspension frame.
7 is an enlarged cross-sectional view taken along the line CC in FIG.
FIG. 8 is a front view schematically showing a primary vibration mode of a suspension frame.
FIG. 9 is a plan view showing a vibration restraint line when the suspension frame is in a primary vibration mode.
FIG. 10 is a perspective view schematically showing a secondary vibration mode of the suspension frame.
11 there is shown a suspension frame structure for an automobile according to a reference example of the present invention, it is a plan view of a suspension frame.
FIG. 12 is a perspective view showing a conventional suspension frame structure of an automobile.
13 is an exploded perspective view of a suspension frame used in the suspension frame structure of FIG.
14 is a plan view of the suspension frame of FIG. 13;
[Explanation of symbols]
1 Suspension frame 1a Upper plate 1b Lower plate 2a, 2b Apron side member (vehicle body)
7a-7c Mounting holes 9a-9c Mounting holes 11a-11c Reinforcing beads 12a, 12b Reinforcing beads 13 Closed cross-sectional shape portion L ₁ Vibration restraint line L ₂ Straight line L in the vehicle width direction L ₃ Straight line in the longitudinal direction of the vehicle body ( Reinforcement bead extension direction straight line)

Claims (3)

In a suspension frame structure for an automobile in which suspension frames for suspending wheels are arranged along the vehicle width direction and both left and right ends of the suspension frame are attached to a vehicle body, the suspension frame includes an upper plate and a lower plate. The suspension frame is formed in a closed cross-sectional shape, and the suspension frame is fixed to the vehicle body by fastening and fastening at three locations, and the suspension frame is fixed to the vehicle body at the fastening locations on both sides. in the innermost and an in the upper surface of the mounting portion in the vehicle longitudinal direction of the intermediate position, the suspension frame structure for an automobile, characterized in that a bi over de extending substantially along the vehicle width direction. The bead for reinforcement, automobile suspension frame structure according to claim 1, characterized in that formed so as to extend substantially along the longitudinal direction of the vehicle body at the lower surface of the attachment points of the suspension frame. Automobile suspension frame structure according to claim 1, characterized in that the formation of the pre millet over de so as to protrude inward of the closed cross section portion.

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