JP2005014728A - Cast suspension member structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cast suspension member structure capable of reconciling securing of rigidity in relation to an input from a suspension arm with securing of energy absorbing performance at the time of a frontal collision. <P>SOLUTION: First reinforcing ribs 50 for connecting a front side mounting part 52 and a rear side mounting part 54 are stood on both sides of a cast front suspension member 10. The first reinforcing ribs 50 are reinforced by a plurality of second reinforcing ribs 56. As a result, the rigidity in relation to the input from the suspension arm is secured. A thin-walled part 58 is formed in a triangular range in plane view on a front side of the rear side mounting part 54. A crash bead 62 is formed in the thin-walled part 58. As a result, energy absorbing stroke at the time of the frontal collision is secured and energy absorbing performance is also ensured. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cast suspension member structure that is formed by casting and includes a suspension front cross member, a suspension rear cross member, and a pair of suspension side members.
[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]
JP-A-6-298121 [0004]
[Problems to be solved by the invention]
By the way, when the cast suspension member structure is adopted, it is very difficult to achieve both ensuring of rigidity with respect to input from the suspension arm and ensuring of energy absorption performance at the time of frontal collision.
[0005]
This is because a suspension member manufactured by press-molding a steel plate should have a shape that can secure rigidity against input from the suspension arm, and a bead or the like having a predetermined shape is formed on a portion that is to be deformed at the time of a frontal collision. By setting, the targeted deformation mode can be realized to some extent. In contrast, cast suspension members made of aluminum alloy, etc., have inherently lower fatigue strength than press-formed suspension members, so a structure that positively deforms when a frontal collision occurs is adopted. It is hard to do.
[0006]
An object of the present invention is to obtain a cast suspension member structure that can achieve both of ensuring rigidity with respect to input from a suspension arm and ensuring energy absorption performance at the time of a frontal collision in consideration of the above facts.
[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 has a suspension front cross member and a suspension rear cross member that are arranged with the vehicle width direction as a longitudinal direction, and a vehicle longitudinal direction that is substantially longitudinal. The suspension suspension member is configured to include a pair of suspension side members arranged in a direction, and the suspension side member is provided with a highly rigid portion along a longitudinal direction thereof, and the suspension rear cross A low-rigidity portion is set at a portion where the member and the suspension side member intersect with each other.
[0008]
The cast suspension member structure according to the second aspect of the present invention is formed by casting, and has a suspension front cross member and a suspension rear cross member that are arranged with the vehicle width direction as a longitudinal direction, and a vehicle longitudinal direction that is substantially longitudinal. A cast suspension member structure including a pair of suspension side members arranged as directions and attached to the body side at a plurality of attachment points respectively set on the front side and the rear side. A high-rigidity portion is set along the longitudinal direction, and a low-rigidity portion is set on the front side of the rear-side attachment point at a portion where the suspension rear cross member and the suspension side member intersect. It is characterized by that.
[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, wherein the high-rigidity portion is set so as to connect a front side attachment point and a rear side attachment point. The low-rigidity part is connected to a part of the high-rigidity part that is located in a predetermined range on the front side of the rear-side attachment point.
[0010]
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 high-rigidity portion extends in the vehicle front-rear direction. And one or more second reinforcing ribs, one end of which is connected to the first reinforcing rib and extends inward in the vehicle width direction, and the second reinforcing rib does not overlap the low-rigidity portion. It is characterized by being set in a range.
[0011]
According to the first aspect of the present invention, the suspension member is formed by casting, and the suspension front cross member and the suspension rear cross member are disposed with the vehicle width direction as the longitudinal direction, and the vehicle longitudinal direction is the longitudinal direction. And a pair of suspension side members arranged as described above.
[0012]
Here, in the present invention, the suspension side member is provided with a highly rigid portion along the longitudinal direction thereof, so that it is possible to support the input from the suspension arm with this highly rigid portion. Therefore, the rigidity with respect to the input from the suspension arm can be ensured.
[0013]
Furthermore, in the present invention, since a low rigidity portion is set at a portion where the suspension rear cross member and the suspension side member intersect, a deformation stroke is secured by the low rigidity portion at the time of a frontal collision. Therefore, the energy absorption performance at the time of a frontal collision can be ensured.
[0014]
According to the second aspect of the present invention, the suspension member is formed by casting, and the suspension front cross member and the suspension rear cross member are disposed with the vehicle width direction as the longitudinal direction, and the vehicle longitudinal direction is the longitudinal direction. And a pair of suspension side members arranged as shown in FIG. 1, and are attached to the body side at a plurality of attachment points respectively set on the front side and the rear side.
[0015]
Here, in the present invention, the suspension side member is provided with a highly rigid portion along the longitudinal direction thereof, so that it is possible to support the input from the suspension arm with this highly rigid portion. Therefore, the rigidity with respect to the input from the suspension arm can be ensured.
[0016]
Furthermore, in the present invention, since a low-rigidity portion is set in front of the rear attachment point at the intersection of the suspension rear cross member and the suspension side member, a deformation stroke is caused by the low-rigidity portion at the time of a frontal collision. Secured. Therefore, the energy absorption performance at the time of a frontal collision can be ensured.
[0017]
According to the third aspect of the present invention, the high-rigidity portion is set so as to connect the front-side attachment point and the rear-side attachment point, and the low-rigidity portion is located on the front side of the rear-side attachment point in the high-rigidity portion. Since it is connected to the part located in the predetermined range, when the collision load at the time of frontal collision is input to the suspension member, it is pushed into the connection part of the high rigidity part with the low rigidity part. ) Is applied. Therefore, not only the low-rigidity part itself is deformed, but also the connection part of the high-rigidity part with the low-rigidity part is drawn into the low-rigidity part side and deformed with the deformation of the low-rigidity part. That is, in the present invention, a cooperative action between the high rigidity portion and the low rigidity portion is obtained.
[0018]
According to the fourth aspect of the present invention, the high-rigidity part includes one or two first reinforcing ribs extending along the vehicle front-rear direction and one end connected to the first reinforcing rib and extending inward in the vehicle width direction. Since it is comprised with the above 2nd reinforcement rib, a 1st reinforcement rib is reinforced with a 2nd reinforcement rib. Therefore, the rigidity with respect to the input from the suspension arm during normal traveling can be increased.
[0019]
Furthermore, since the second reinforcing rib is set in a range that does not overlap the low-rigidity portion, it does not hinder the deformation of the low-rigidity portion at the time of a frontal collision. Further, the first reinforcing rib itself is easily deformed in a range where the supporting force by the second reinforcing rib cannot be obtained.
[0020]
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.
[0021]
FIG. 3 is a perspective view showing the overall configuration of the front suspension member 10 according to this embodiment, and FIG. 2 is a plan view showing the overall configuration of the front suspension member 10. Further, FIG. 1 is an enlarged plan view showing the main part of the front suspension member 10.
[0022]
As shown in FIGS. 3 and 2, 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. And a pair of front suspension side members 16 and 18 arranged in parallel on the left and right sides, 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.
[0023]
A gear box mounting portion 42 for mounting a steering gear box (not shown) is integrally formed on both sides of the front surface of the front suspension front cross member 12 in the front suspension member 10 described above. A steering gear box is fixed by inserting a bolt (not shown) into the formed bolt insertion hole 43 and fastening it to a nut.
[0024]
A front mounting base 24 and a rear mounting base 26 for swingably mounting inner ends of a pair of left and right front suspension arms (not shown) are parallel to the front and rear sides of the pair of front side portions of the front suspension member 10. Are integrally formed. The front mounting base 24 and the rear mounting base 26 are formed with bolt insertion holes 28 on the same axis, and a bush press-fitted into the inner end of the front suspension arm is inserted between them. A bolt is inserted into the bolt insertion hole 28 and fastened to the nut, so that the pair of left and right front suspension arms are pivotally supported.
[0025]
Here, as shown in FIG. 1 and the like, in the present embodiment, a belt-like first reinforcement extending along the vehicle front-rear direction on the outer edge portions of the front suspension side members 16 and 18 in the front suspension member 10 described above. The rib 50 is integrally formed. Each first reinforcing rib 50 is erected so as to connect a front side mounting portion 52 and a rear side mounting portion 54 provided at the four corners of the front suspension member 10 in the front-rear direction.
[0026]
Further, a plurality of right-angled triangular second reinforcing ribs 56 are erected on the inner side of the first reinforcing rib 50 along the vehicle width direction. These second reinforcing ribs 56 are arranged at predetermined intervals along the vehicle front-rear direction, and the outer ends are connected in a state orthogonal to the first reinforcing rib 50.
[0027]
In addition, a thin portion 58 is formed over a predetermined range (a triangular range shown by hatching in FIG. 1A) on the front side of the rear mounting portion 54 in the front suspension member 10 described above. . The plate thickness t of the thin portion 58 (see FIG. 1C) is set to be thinner than the plate thickness of the general portion 60 of the front suspension member 10. Therefore, the surface rigidity of the thin portion 58 is intentionally set lower than the surface rigidity of the general portion 60. The second reinforcing rib 56 described above is set so as not to overlap the range where the thin portion 58 is formed.
[0028]
Further, a crush bead 62 is formed on the inner side of the rear end side of the first reinforcing rib 50 in the thin-walled portion 58. The crash bead 62 has an elongated oval shape in a plan view and a cross-sectional hat shape that protrudes upward. Has been. The crash bead 62 is formed substantially parallel to the rear end side of the first reinforcing rib 50. By forming the crash bead 62, the rigidity of the portion where the crash bead 62 is formed becomes higher (becomes difficult to deform) in the vehicle front-rear direction and is lower in the vehicle width direction ( It is easy to deform).
[0029]
Next, the operation and effect of this embodiment will be described.
[0030]
Since the pair of left and right first reinforcing ribs 50 are provided upright along the vehicle front-rear direction at the outer edge portions of the pair of front suspension side members 16, 18 in the front suspension member 10, The rigidity against is higher than usual. Further, a plurality of second reinforcing ribs 56 extending in the vehicle width direction are connected to the first reinforcing rib 50, thereby enhancing the support rigidity. Thereby, the rigidity of the front suspension member 10 in the vehicle longitudinal direction is sufficiently ensured. Accordingly, even when a load F (see FIG. 1A) is input to the front suspension member 10 from a suspension arm (not shown) during normal traveling, the front suspension member 10 is not deformed or broken such as cracks. .
[0031]
On the other hand, during a frontal collision, a collision load on the vehicle rear side is input to the pair of front suspension side members 16 and 18 of the front suspension member 10. Here, in the present embodiment, since the thin portion 58 is formed on the front side of the rear side mounting portion 54, the rigidity in the vehicle width direction is lower than that of the general portion 60. Furthermore, since the crush bead 62 is formed substantially parallel to the rear end side of the first reinforcing rib 50 within the formation range of the thin portion 58, it is easy to deform in the vehicle width direction. In addition, since the second reinforcing rib 56 described above is provided in a range that does not overlap the thin portion 58, the rear end side of the first reinforcing rib 50 is more easily deformed in the vehicle width direction than the front end side. . Accordingly, when a collision load is input, as shown in FIG. 1B, the rear end side of the first reinforcing rib 50 (the second reinforcing rib 56 disposed at the rearmost end and the rear side mounting portion). 54) and compressively plastically deformed inward in the vehicle width direction. That is, the deformation proceeds so that the rear end side of the first reinforcing rib 50 enters the inside of the thin portion 58 while crushing the crush bead 62 in the bead width direction. From the above action, according to the present embodiment, it is possible to sufficiently secure the deformation stroke of the front suspension member 10 at the time of a frontal collision.
[0032]
As described above, in the cast suspension member structure according to the present embodiment, the front suspension side members 16 and 18 are provided with the first reinforcing ribs 50 along the longitudinal direction thereof, and the front suspension rear cross member 14 and the front suspension side member. Since the thin-walled portion 58 and the crash bead 62 are set at a portion where the crossing portions 16 and 18 intersect (the front side of the rear-side mounting portion 54), the rigidity with respect to the input from the front suspension arm and the energy absorption performance at the time of a frontal collision are ensured. Can be made compatible.
[0033]
Further, in the cast suspension member structure according to the present embodiment, the first reinforcing rib 50 is set so as to connect the front side mounting portion 52 and the rear side mounting portion 54, and the thin portion 58 is formed in the first reinforcing rib 50. Since it is connected to a portion located in a predetermined range on the front side of the rear side mounting portion 54, when a collision load at the time of a frontal collision is input to the front suspension member 10, the thin portion 58 and the crash bead 62 themselves are deformed. Not only that, but with the deformation of the thin portion 58 and the crash bead 62, the connecting portion of the first reinforcing rib 50 with the thin portion 58 acts to draw the thin portion 58 side. That is, in the present embodiment, as a result of the cooperative action of the first reinforcing rib 50 and the thin portion 58, the first reinforcing rib 50 can be effectively and quickly deformed inward in the vehicle width direction. As a result, according to this embodiment, the energy absorption performance at the time of frontal collision can be improved.
[0034]
Furthermore, in the cast suspension member structure according to the present embodiment, a plurality of second reinforcements extending in the vehicle width direction are provided in addition to the first reinforcement ribs 50 extending substantially along the vehicle longitudinal direction. Since the end portion of the rib 56 is connected to the first reinforcing rib 50, the first reinforcing rib 50 can be reinforced by the plurality of second reinforcing ribs 56. Therefore, the rigidity with respect to the input from the front suspension arm during normal traveling can be increased. In addition, since the second reinforcing rib 56 is set in a range that does not overlap the thin portion 58, the deformation of the thin portion 58 is not inhibited by the second reinforcing rib 56 at the time of a frontal collision. Further, the first reinforcing rib 50 itself is easily deformed as long as the supporting force by the second reinforcing rib 56 cannot be obtained. As a result, according to the present embodiment, it is possible to achieve both of ensuring rigidity with respect to input from the front suspension arm and ensuring energy absorption performance at the time of frontal collision with higher accuracy.
[0035]
Further, in the cast suspension member structure according to the present embodiment, the crush bead 62 is provided on the front side of the rear side mounting portion 54 of the front suspension member 10 (that is, not the peripheral edge portion of the front suspension member 10). There is no disadvantage that impairs the fatigue strength of the member 10. That is, in the case of the configuration disclosed in Patent Document 1 cited as the prior art document, a plurality of notches are set in the peripheral portion of the suspension member. When running, stress concentration occurs in the notch, which may cause fatigue failure. However, in the case of this embodiment, there is no such disadvantage.
[0036]
[Second Embodiment]
Hereinafter, a second embodiment (several variations of the crash bead) of the cast suspension member structure according to the present invention 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.
[0037]
In the embodiment shown in FIGS. 4A and 4B, a wide crush bead 70 formed in a substantially equilateral triangular shape in plan view is formed on the front side of the rear side mounting portion 54 of the front suspension member 10. ing. One side of the crash bead 70 is disposed substantially parallel to the first reinforcing rib 50.
[0038]
The configuration other than the crash bead 70 (setting of the first reinforcing rib 50, the second reinforcing rib 56, setting of the thin portion 58, etc.) is the same as that in the first embodiment described above (this point will be described later). The same applies to the embodiments of FIGS.
[0039]
In the embodiment shown in FIGS. 5A and 5B, an opening (hole) having a plane shape substantially the same as that of the crash bead 62 of the first embodiment is formed on the front side of the rear side mounting portion 54 of the front suspension member 10. 72 is formed.
[0040]
In the embodiment shown in FIGS. 6A and 6B, a pair of crash beads 74 that are narrower and narrower than the crash beads 62 of the first embodiment are arranged side by side in the vehicle width direction.
[0041]
Regardless of the configuration shown in FIGS. 4, 5, or 6, the same operations and effects as those of the first embodiment described above can be obtained.
[0042]
[Supplementary explanation of the embodiment]
In each of the embodiments 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.
[0043]
Moreover, in each embodiment mentioned above, although the structure which sets the 1st reinforcement rib 50 and the 2nd reinforcement rib 56 as a highly rigid part was employ | adopted, not only this but structure (for example, plate | board thickness is increased) other than a rib. Etc.).
[0044]
Furthermore, in each embodiment mentioned above, although the thin part 58 and the crush beads 62, 70, 74, or the opening 72 were used together as a low rigidity part, not only this but a low rigidity part is comprised only in any one. Also good.
[0045]
【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 has a suspension front cross member and a suspension rear cross member that are arranged with the vehicle width direction as a longitudinal direction. A structure including a pair of suspension side members arranged substantially in the longitudinal direction of the vehicle, the suspension side member is provided with a highly rigid portion along the longitudinal direction, and the suspension rear cross member and the suspension Since the low-rigidity portion is set at the portion where the side member intersects, it has an excellent effect that it is possible to achieve both of ensuring rigidity with respect to the input from the suspension arm and ensuring energy absorption performance at the time of frontal collision.
[0046]
The cast suspension member structure according to the second aspect of the present invention is formed by casting, and has a suspension front cross member and a suspension rear cross member that are arranged with the vehicle width direction as a longitudinal direction, and a vehicle longitudinal direction that is substantially longitudinal. And a pair of suspension side members arranged as directions, and attached to the body side at a plurality of attachment points set on the front side and the rear side, respectively, along the longitudinal direction of the suspension side member In addition to setting a high-rigidity part, a low-rigidity part was set in front of the rear mounting point at the intersection of the suspension rear cross member and suspension side member. Ensuring energy absorption performance It has an excellent effect that it is possible to achieve both.
[0047]
The cast suspension member structure according to the present invention described in claim 3 is the invention according to claim 1 or 2, wherein the high-rigidity portion is set so as to connect the front-side attachment point and the rear-side attachment point, Since the low-rigidity part is connected to the part of the high-rigidity part that is located in a predetermined range in front of the rear mounting point, both can be deformed by the cooperative action of the high-rigidity part and the low-rigidity part during a frontal collision. As a result, the energy absorption performance at the time of frontal collision can be improved.
[0048]
The cast suspension member structure according to a fourth aspect of the present invention is the arrangement according to any one of the first to third aspects, wherein the high-rigidity portion extends along the vehicle front-rear direction, Since one end is connected to the first reinforcing rib and is configured by one or more second reinforcing ribs extending inward in the vehicle width direction, and further, the second reinforcing rib is set within a range not overlapping the low-rigidity portion. In addition, it has an excellent effect that it is possible to achieve both higher rigidity with respect to ensuring rigidity with respect to input from the suspension arm and ensuring energy absorption performance at the time of frontal collision.
[Brief description of the drawings]
FIG. 1A is an enlarged plan view showing a main part of a cast suspension member structure according to a first embodiment in a state of normal running, and FIG. 1B is a state of the main part of the cast suspension member structure in a frontal collision. (C) is CC sectional view taken on the line which shows the cross-sectional shape of a crush bead.
FIG. 2 is a plan view showing an overall configuration of a front suspension member according to the first embodiment.
FIG. 3 is a perspective view showing an overall configuration of a front suspension member according to the first embodiment.
4A is an enlarged plan view showing a main part of a first modified example of a crash bead according to the second embodiment, and FIG. 4B is a cross-sectional view taken along line BB showing a cross-sectional shape of the crash bead; FIG.
5A is an enlarged plan view showing a main part of a second modified example of the crash bead, and FIG. 5B is a sectional view taken along line BB showing the sectional shape of the opening according to the second embodiment. is there.
6A is an enlarged plan view showing a main part of a third modified example of the crash bead according to the second embodiment, and FIG. 6B is a cross-sectional view taken along the line BB showing the cross-sectional shape of the crash bead. FIG.
[Explanation of symbols]
10 front suspension member 12 front suspension front cross member 14 front suspension rear cross member 16 front suspension side member 18 front suspension side member 50 first reinforcing rib (high rigidity portion)
52 Front side mounting part (Front side mounting point)
54 Rear side mounting part (Rear side mounting point)
56 Second reinforcement rib (high rigidity part)
58 Thin part (low rigidity part)
62 Crash beads (low rigidity part)
70 Crash beads (low rigidity part)
72 Opening (low rigidity part)
74 Crash beads (low rigidity part)

Claims (4)

A suspension front cross member and a suspension rear cross member that are formed by casting and are arranged with the vehicle width direction as a longitudinal direction, and a pair of suspension side members that are arranged with a vehicle longitudinal direction as a longitudinal direction. Cast suspension member structure,
The suspension side member is set with a highly rigid portion along its longitudinal direction,
A low-rigidity portion is set at a portion where the suspension rear cross member and the suspension side member intersect.
A cast suspension member structure characterized by that. A suspension front cross member and a suspension rear cross member that are formed by casting and are arranged with the vehicle width direction as a longitudinal direction, and a pair of suspension side members that are arranged with a vehicle longitudinal direction as a longitudinal direction. A cast suspension member structure that is attached to the body side at a plurality of attachment points set on the front side and the rear side,
The suspension side member is set with a highly rigid portion along its longitudinal direction,
A low-rigidity portion is set on the front side of the rear-side attachment point at a portion where the suspension rear cross member and the suspension side member intersect.
A cast suspension member structure characterized by that. The high-rigidity part is set so as to connect a front side attachment point and a rear side attachment point,
The low-rigidity part is connected to a portion located in a predetermined range on the front side of the rear-side attachment point in the high-rigidity part.
3. The cast suspension member structure according to claim 1, wherein the suspension member structure is a cast suspension member structure. The high-rigidity portion is configured by a first reinforcing rib extending along the vehicle front-rear direction, and one or more second reinforcing ribs having one end connected to the first reinforcing rib and extending inward in the vehicle width direction. And
Furthermore, the second reinforcing rib is set in a range that does not overlap the low rigidity portion.
The cast suspension member structure according to any one of claims 1 to 3, wherein the cast suspension member structure is provided.

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