JP4206840B2 - Cast suspension member structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cast suspension member structure which is formed by casting and has a first attachment portion to which a suspension arm is attached and a second attachment portion to which a steering gear box is attached connected via a connection portion.
[0002]
[Prior art]
Conventionally, a suspension member is provided as a member for supporting a suspension arm and a steering gear box. In general, the suspension member is manufactured by press-molding a steel plate. Recently, however, there is an increasing need for manufacturing the suspension member by casting using an aluminum alloy or the like from the viewpoint of weight reduction.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 11-115796
[Problems to be solved by the invention]
By the way, in the case of the above-described cast suspension member by aluminum die casting, there is a problem that the fatigue strength is lower than that of a press-formed product of a steel plate. In addition, the suspension member of the cast aluminum product has a disadvantage that it has a relatively small elongation and is easily broken. Because of these characteristics, when using a cast suspension member by aluminum die casting, the stress generated when road input is transmitted through the suspension arm is minimized, and the stress is concentrated on a specific part of the suspension member. It was necessary to avoid as much as possible.
[0005]
Further, when a cast suspension member by aluminum die casting is used, there is a possibility that a problem of electrolytic corrosion (contact corrosion) occurs. That is, if a steel plate is used as a mounting bracket such as a suspension arm that is attached to the suspension member, a potential difference is generated between the two when different metals are in contact with each other. Usually, there is a concern that corrosion of the suspension member is promoted due to the fact that the anticorrosive paint hardly adheres to the terminal portion (edge) of the mounting bracket (the coating film tends to become thin).
[0006]
An object of the present invention is to obtain a cast suspension member structure that can suppress the occurrence of stress concentration when the suspension member is formed by casting in consideration of the above-described fact, and further has excellent electric corrosion resistance.
[0007]
[Means for Solving the Problems]
The cast suspension member structure according to the first aspect of the present invention is formed by casting, and the first attachment portion to which the suspension arm is attached and the second attachment portion to which the steering gear box is attached are connected via the connection portion. The cast suspension member structure is characterized in that a connecting member for connecting the first mounting portion and the second mounting portion is provided independently of the connecting portion.
[0008]
The cast suspension member structure according to a second aspect of the present invention is the cast suspension member structure according to the first aspect of the present invention, wherein the terminal portion and the suspension member maintain a non-contact state in part or all of the terminal portion of the connecting member. It is characterized in that a bent portion is provided.
[0009]
A cast suspension member structure according to a third aspect of the present invention is the cast suspension member structure according to the first or second aspect of the present invention, wherein the suspension member and / or at least one of the connection members is provided with a detent of the connection member with respect to the suspension member. It is characterized by the provision of a detent portion that constitutes.
[0010]
A cast suspension member structure according to a fourth aspect of the present invention is the cast suspension member structure according to any one of the first to third aspects, wherein the connecting member is formed in a plate shape, and the connecting member is the suspension. Of the pair of cross members disposed before and after the member, the front cross member is disposed on the vehicle front side of the first mounting portion and the second mounting portion.
[0011]
The cast suspension member structure according to a fifth aspect of the present invention is the cast suspension member structure according to any one of the first to fourth aspects, wherein the connecting member is disposed close to the connecting portion on the first mounting portion side. On the other hand, it is characterized in that the second mounting portion side is disposed apart from the connecting portion.
[0012]
According to the first aspect of the present invention, the suspension member is provided with the first attachment portion to which the suspension arm is attached and the second attachment portion to which the steering gear box is attached. Connected to each other. Therefore, when a load is input from the suspension arm, the load is transmitted to the connecting portion and is received by the connecting portion.
[0013]
Here, since the suspension member of the present invention is formed by casting, it is generally low in fatigue strength and easily cracked when compared with a press-formed product. However, in the present invention, since the first mounting portion and the second mounting portion are connected by the connecting member independently of the connecting portion, the load input from the suspension arm is also supported by the connecting member. That is, the load burden on the original connecting portion is reduced. Therefore, it can suppress that stress concentration arises in the specific site | part of a connection part.
[0014]
According to the second aspect of the present invention, the bent portion is provided in a part or all of the end portion of the connecting member so that the end portion of the connecting member and the suspension member are not in contact with each other. The suspension member and the connecting member do not come into contact with each other at the portion where the portion is provided. Therefore, even if the connecting member is made of a dissimilar metal material different from that of the suspension member, the problem of electrolytic corrosion does not occur.
[0015]
According to the third aspect of the present invention, the anti-rotation portion that forms the anti-rotation of the connecting member with respect to the suspension member is provided in at least one of the suspension member and the connecting member. It is possible to prevent the connecting member from idling at the time of mounting.
[0016]
According to the fourth aspect of the present invention, the connecting member is formed in a plate shape, and the first connecting portion of the front cross member and the first connecting member of the pair of cross members arranged before and after the suspension member are connected to the connecting member. 2 Since the mounting portion is disposed on the vehicle front side , the connecting member first interferes with the road surface when the road surface interferes.
[0017]
According to the fifth aspect of the present invention, the connecting member is disposed close to the connecting portion on the first mounting portion side, while being spaced apart from the connecting portion on the second mounting portion side. The load input from the arm can be supported in a stable state.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
Hereinafter, the front suspension member 10 according to the first embodiment to which the present invention is applied will be described with reference to FIGS.
[0019]
FIG. 5 is a perspective view showing the overall configuration of the front suspension member 10 according to the present embodiment, and FIG. 1 is an enlarged perspective view showing the main part of the front suspension member 10. 2 is a longitudinal sectional view taken along the line 2-2 of the front suspension member 10, and FIG. 3 is a transverse sectional view taken along the line 3-3 of the front suspension member 10. FIG. 4 is a longitudinal sectional view of the front suspension member 10 taken along line 4-4.
[0020]
As shown in FIG. 5, the front suspension member 10 includes a pair of front suspension front cross member 12 and front suspension rear cross member 14 arranged in parallel in the front-rear direction along the vehicle width direction, and the vehicle front-rear direction. A pair of front suspension side members 16 and 18 arranged in parallel to the left and right are configured, and the whole is formed in a well shape in plan view. The front suspension member 10 is formed by casting (aluminum die casting) using an aluminum alloy.
[0021]
A steering gear box 20 (see FIG. 3) is arranged on the front side of the front suspension front cross member 12 in the front suspension member 10 described above. A pair of front suspension arms 22 (see FIG. 2) is pivotally supported so as to be swingable.
[0022]
More specifically, as shown in an enlarged view in FIG. 1, a front mounting base 24 and a rear mounting base 26, which are integrally formed in a plate shape, are respectively provided in the front corner portion of the front suspension member 10. They are arranged in parallel. Bolt insertion holes 28 are formed on the outer corners of the front mounting base 24 and the rear mounting base 26 on the same axis, and the portion where the bolt insertion holes 28 are formed is for attaching the front suspension arm 22. These are a front arm mounting portion 30 and a rear arm mounting portion 32. A bush 34 (see FIG. 2) press-fitted into the inner end portion of the front suspension arm 22 is inserted between the front arm mounting portion 30 and the rear arm mounting portion 32 and can be swung by a bolt 36 and a nut 38. It is attached.
[0023]
In addition, a gear box mounting portion 42 for mounting the steering gear box 20 is integrally formed at a corner portion on the inner side of the front mounting base 24 described above while being formed in a flat and substantially cylindrical shape. A bolt insertion hole 43 is formed in the shaft core portion of the gear box mounting portion 42. The steering gear box 20 (note that a plan view showing the overall configuration of the steering gear box 20 is shown in FIG. 6 in the second embodiment) is fixed to a pair of left and right gear box mounting portions 42 by bolts 44 and nuts 46. Has been.
[0024]
To summarize the configuration so far, in the cast suspension member structure according to the present embodiment, the front arm attachment portion 30 as the “first attachment portion” and the gear box attachment portion as the “second attachment portion” in the front suspension member 10. 42 are connected to each other in the vehicle width direction by a front mounting base 24 as a plate-like “connecting portion” arranged in a standing state along the vehicle width direction.
[0025]
Here, as shown in FIGS. 1 to 4, in the present embodiment, the above-described front arm mounting portion 30 and gear box mounting portion 42 are made of metal (made of steel plate) formed into a strip shape by press forming. ) Plates (braces) 48.
[0026]
More specifically, the plate 48 is disposed vertically on the front side of the front suspension front cross member 12. A flat arm side mounting portion 50 is formed at the outer end portion of the plate 48 corresponding to the front arm mounting portion 30, and the inner end portion of the plate 48 corresponds to the gear box mounting portion 42. A flat gearbox side mounting portion 52 is formed.
[0027]
Further, the plate 48 is bent at two locations, an inner end of the arm side mounting portion 50 and an outer end of the gear box side mounting portion 52 (see FIG. 3). Thus, when the front suspension arm 22 and the steering gear box 20 are assembled via the plate 48, the plate 48 is moved by a predetermined distance D (see FIG. 3) in the vehicle front-rear direction on the gear box mounting portion 42 side. The front mounting base 24 is spaced apart.
[0028]
In addition, a bent portion 54 having an arcuate surface shape is formed integrally with a peripheral portion (upper edge portion, lower edge portion, outer edge portion) of the plate 48 other than the gear box side attachment portion 52. Thereby, the terminal portion of each bent portion 54 of the plate 48 is maintained (held) in a non-contact state with respect to the front end surface of the front mounting base 24.
[0029]
In addition, a pair of upper and lower protrusion-shaped detent ribs 40 and 41 are erected on the outer peripheral portion of the gear box mounting portion 42 described above. As shown in FIGS. 1 and 4, the tip of the upper detent rib 40 abuts the inner surface of the bent portion 54 on the upper edge side of the plate 48 in a surface contact state, and the lower detent rib The front end portion 41 abuts the inner surface of the bent portion 54 on the lower edge side of the plate 48 in a surface contact state, thereby preventing the plate 48 from rotating relative to the front suspension member 10 when the bolt is fastened.
[0030]
Next, the operation and effect of this embodiment will be described.
[0031]
When the vehicle travels, a load F (see FIG. 3) is input to the front suspension member 10 via the front suspension arm 22 by road surface input. Here, in the present embodiment, the front arm attachment portion 30 to which the front suspension arm 22 is attached and the gear box attachment portion 42 to which the steering gear box 20 is attached via the front attachment base 24 of the front suspension front cross member 12. Since it is assumed that the structures are connected to each other, the input load F is transmitted to the front mounting base 24. For this reason, stress concentration occurs in the portion indicated by the arrow P in FIG. 3, which is a connection portion to the gear box mounting portion 42.
[0032]
By the way, since the front suspension member 10 of this embodiment is formed by casting, the fatigue strength is generally low and easily cracked when compared with a press-formed product. However, in the present embodiment, since the front arm mounting portion 30 and the gear box mounting portion 42 are connected by the plate 48 formed by press molding independently of the front mounting base 24, the front suspension arm 22 is inputted. The load F is also supported by the plate 48. That is, the load load is Fs smaller than F at the P line arrow portion of the front mounting base 24, and the load load of the plate 48 is Fp smaller than F and larger than Fs. In other words, the load burden on the front mounting base 24 that originally has a lower fatigue strength is reduced. As a result, according to the present embodiment, when the front suspension member 10 is configured by casting, it is possible to suppress the stress concentration from occurring at a specific part (part indicated by the arrow P) of the front mounting base 24.
[0033]
In the cast suspension member structure according to the present embodiment, the front arm mounting portion 30 and the gear box mounting portion 42 are connected to each other by the plate 48 formed by press molding, independently of the front mounting base 24. Even if the front mounting base 24 is damaged, the connection state between the plates 48 is not released, so that the front suspension arm 22 can be prevented from falling off the front suspension member 10.
[0034]
Furthermore, in the cast suspension member structure according to the present embodiment, the bent portions 54 are set at the upper edge portion, the lower edge portion, and the outer edge portion of the plate 48, so that the end portion of the plate 48 and the front suspension front of the front suspension member 10 are set. The cross member 12 maintains a non-contact state. Therefore, even if the front suspension member 10 is made of an aluminum alloy casting and the plate 48 is made of a steel plate made of a different material as in this embodiment, the problem of electrolytic corrosion does not occur. As a result, according to the present embodiment, not only the problem of stress concentration with respect to the input F from the front suspension arm 22 can be solved, but also the electric corrosion resistance can be improved.
[0035]
Further, in the cast suspension member structure according to the present embodiment, the pair of detent ribs 40 and 41 that form the detent of the plate 48 are integrally formed on the outer peripheral portion of the gear box mounting portion 42 in the front suspension front cross member 12. Further, it is possible to prevent the plate 48 from idling when the front suspension arm 22 is assembled to the front arm attachment portion 30 and the rear arm attachment portion 32 (when the bolt 36 is fastened). As a result, according to this embodiment, the workability of assembling the front suspension arm 22 to the front suspension member 10 can be improved.
[0036]
Further, in the cast suspension member structure according to the present embodiment, the plate 48 is disposed on the front side of the front arm attachment portion 30 of the front suspension front cross member 12 and the gear box attachment portion 42 of the gear box attachment portion 42, so that road surface interference occurs. Sometimes the plate 48 first interferes with the road surface. For this reason, it is possible to prevent the front suspension member 10 from being damaged such as a crack.
[0037]
Furthermore, in the cast suspension member structure according to the present embodiment, the plate 48 is bent at two locations in the middle to separate (offset) the plate 48 from the front end surface of the front suspension front cross member 12 by a distance D (see FIG. 3). Therefore, the load F input from the front suspension arm 22 can be supported in a stable state.
[0038]
[Second Embodiment]
Hereinafter, the second embodiment will be described with reference to FIGS. In addition, about the same component as 1st Embodiment mentioned above, the same number is attached | subjected and the description is abbreviate | omitted.
[0039]
FIG. 6 is a plan view showing the overall configuration of the front suspension member 10 according to the present embodiment. FIG. 7 shows a schematic side view of the state in which the front suspension member 10 is disposed as viewed from the side of the vehicle. Further, FIG. 8 shows an enlarged view of the portion indicated by the arrow 8 in FIG.
[0040]
As can be seen from these drawings, the present embodiment is not characterized by the configuration of the front suspension member 10 itself, but by the peripheral structure of the front suspension member 10. The front suspension member 10 of the present embodiment is also a cast product as in the first embodiment described above.
[0041]
More specifically, a flat plate-shaped protector 60 is disposed below the front suspension front cross member 12 in the front suspension member 10. As shown in FIG. 6, the protector 60 includes a belt-like main body 62 disposed below the front suspension front cross member 12 and an intermediate portion in the longitudinal direction of the main body 62 (the vehicle width direction in the assembled state). And a substantially “concave” -shaped extending portion 64 that extends toward the front side of the vehicle. The extending portion 64 is disposed below the steering gear box 20. Furthermore, the bifurcated tip portion of the extending portion 64 is bent at a predetermined inclination angle so as to extend toward the stabilizer 66 (see FIG. 8) (generally flush with the stabilizer 66). (Hereinafter, this portion is referred to as “warped shape portion 64A”).
[0042]
On the other hand, a flat engine under cover 68 is disposed below the steering gear box 20 and the stabilizer 66. The rear portion 68A of the engine under cover 68 is arranged in a state of overlapping with the lower surface side of the extension portion 64 of the protector 60 described above.
[0043]
Next, the operation and effect of this embodiment will be described.
[0044]
As shown in FIG. 9, when the lower surface of the front portion of the vehicle interferes with an obstacle 70 such as a road surface or a curb when the vehicle travels, the intermediate portion in the front-rear direction of the engine undercover 68 is lifted until it contacts the stabilizer 66. On the other hand, since the rear portion 68A of the engine under cover 68 is under the extension portion 64 of the protector 60, the rear portion 68A of the engine under cover 68 is pushed up to the extent that it matches the inclination of the warped shape portion 64A of the protector 60. It is done.
[0045]
Thus, the interference object 70 slides on the lower surface of the slide-like inclined portion 72 formed between the stabilizer 66 and the warped shape part 64A of the protector 60 as shown in the figure, so that the interference object 70 becomes the steering gear box 20 or Strong interference with the front suspension member 10 can be avoided.
[0046]
In addition, in this embodiment mentioned above, although the structure in which the slide part-shaped inclination part 72 was formed between the stabilizer 66 and the curvature shape part 64A of the protector 60 was taken, it is not restricted to this but is shown by FIG. In addition, the cross member 74 may be used instead of the stabilizer 66, or other members may be used.
[0047]
[Supplementary explanation of the first embodiment]
In the first embodiment described above, the cast suspension member structure according to the present invention is applied to the front suspension member 10. However, the present invention is not limited to this, and the present invention can also be applied to the rear suspension member.
[0048]
In the first embodiment described above, the plate 48 is disposed at a predetermined distance D from the front mounting base 24. However, the present invention is not limited to this, and a member corresponding to the plate is in close contact with the front mounting base 24. It may be arranged. Even in this case, since the load is shared, the effect of avoiding stress concentration on the front mounting base 24 can be expected to some extent.
[0049]
Furthermore, in 1st Embodiment mentioned above, although the bending part 54 was set to the upper edge part of the plate 48, a lower edge part, and an outer edge part, not only this but the bending part 54 is extended over the perimeter of the plate 48. It may be set.
[0050]
Further, in the first embodiment described above, the configuration in which the pair of upper and lower rotation prevention ribs 40 and 41 are integrally provided on the outer peripheral portion of the gear box mounting portion 42 is not necessarily provided integrally, but the rotation prevention portion is not necessarily provided. The gear box mounting portion 42 may be provided separately. Further, in place of the protrusion-like detent ribs 40 and 41, for example, substantially right-angled triangular recesses are formed at predetermined intervals on the outer peripheral surface of the gear box mounting portion 42, and the plate 48 is provided with the recesses. The anti-rotation portion may be configured by providing an engaging projection by a cut-and-raised portion that elastically engages.
[0051]
【The invention's effect】
As described above, the cast suspension member structure according to the first aspect of the present invention is formed by casting, and includes the first attachment portion to which the suspension arm is attached and the second attachment portion to which the steering gear box is attached. In the structure connected via the connecting portion, since the connecting member for connecting the first attaching portion and the second attaching portion is provided independently of the connecting portion, the load on the connecting portion can be reduced. As a result, when the suspension member is formed by casting, it has an excellent effect that stress concentration can be suppressed.
[0052]
A cast suspension member structure according to a second aspect of the present invention is the cast suspension member structure according to the first aspect of the present invention, wherein the terminal portion and the suspension member maintain a non-contact state with part or all of the terminal portion of the connecting member. Since the bent portion is provided as described above, it is possible to avoid contact between the suspension member and the connecting member at the portion where the bent portion is provided, and as a result, it is possible to eliminate the problem of stress concentration with respect to the input from the suspension arm. In addition to being able to do so, it has an excellent effect of being able to improve electric corrosion resistance.
[0053]
A cast suspension member structure according to a third aspect of the present invention is the casting suspension member structure according to the first or second aspect, wherein at least one of the suspension member and the coupling member is configured to prevent rotation of the coupling member relative to the suspension member. Since the stop portion is provided, it is possible to prevent the connecting member from spinning when the suspension arm is assembled, and as a result, the suspension arm can be easily assembled to the first mounting portion. .
[0054]
The cast suspension member structure according to a fourth aspect of the present invention is the cast suspension member structure according to any one of the first to third aspects, wherein the connecting member is formed in a plate shape, and the connecting member is disposed before and after the suspension member. Since the first mounting portion and the second mounting portion of the front cross member of the pair of cross members disposed on the front side of the vehicle are disposed on the front side of the vehicle , the connecting member can be caused to interfere with the road surface at the time of road surface interference. The suspension member can be prevented from being damaged by road surface interference.
[0055]
The cast suspension member structure according to a fifth aspect of the present invention is the cast suspension member structure according to any one of the first to fourth aspects, wherein the connecting member is disposed close to the connecting portion on the first mounting portion side. Since the second mounting portion is disposed away from the connecting portion, the load input from the suspension arm can be supported in a stable state. As a result, the load applied to the connecting portion of the suspension member is minimized. It has an excellent effect that it can be suppressed to the limit.
[Brief description of the drawings]
FIG. 1 is an enlarged perspective view showing a main part of a cast suspension member structure according to a first embodiment.
FIG. 2 is a longitudinal sectional view taken along line 2-2 of FIG.
3 is a cross-sectional view taken along line 3-3 in FIG.
4 is a longitudinal sectional view taken along line 4-4 of FIG.
FIG. 5 is a perspective view schematically showing an overall configuration of the front suspension member of FIG. 1;
FIG. 6 is a plan view showing an overall configuration of a front suspension member according to a second embodiment.
7 is a schematic side view of the state in which the front suspension member shown in FIG. 6 is disposed as viewed from the side of the vehicle.
8 is an enlarged side view of the portion taken along line 8 of FIG.
FIG. 9 is an enlarged side view corresponding to FIG. 8 for explaining the action when interfering with a curbstone or the like.
FIG. 10 is an enlarged side view corresponding to FIG. 8 showing a modification.
[Explanation of symbols]
10 Front suspension member
12 Front suspension Front cross member (Front cross member)
14 Front suspension Rear cross member (cross member)
20 Steering gear box 22 Front suspension arm 24 Front mounting base (connecting part)
30 Front arm mounting part (first fixed part)
40 Anti-rotation rib (anti-rotation part)
41 Anti-rotation rib (anti-rotation part)
42 Gearbox mounting part (second fixed part)
48 plates (connection members)
54 Folding part

Claims (5)

A cast suspension member structure is formed by casting, and a first attachment portion to which a suspension arm is attached and a second attachment portion to which a steering gear box is attached are connected via a connection portion,
Independently of the connecting portion, a connecting member for connecting the first mounting portion and the second mounting portion is provided.
A cast suspension member structure characterized by that. A bent part is provided on a part or all of the terminal part of the connecting member so that the terminal part and the suspension member maintain a non-contact state.
The cast suspension member structure according to claim 1. At least one of the suspension member and the connection member is provided with a rotation preventing portion that prevents rotation of the connection member with respect to the suspension member.
3. The cast suspension member structure according to claim 1, wherein the suspension member structure is a cast suspension member structure. The connecting member is formed in a plate shape,
The connecting member is disposed on the vehicle front side of the first mounting portion and the second mounting portion of the front cross member among the pair of cross members disposed before and after the suspension member.
The cast suspension member structure according to any one of claims 1 to 3, wherein the cast suspension member structure is provided. The connecting member is arranged close to the connecting part on the first attaching part side, and is arranged apart from the connecting part on the second attaching part side,
The cast suspension member structure according to any one of claims 1 to 4, wherein the cast suspension member structure is provided.

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