JP2000255234A - Suspension arm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a suspension arm by forming a recessed part on the lower surface of a sheet metal-made suspension arm body having a closed sectional structure, connecting and fixing a reinforcing bracket to the recessed part, and forming a jack contact part on at least one of the reinforcing bracket and the recessed part. SOLUTION: A jack contact part A for jack up is formed on a lower arm 1 arranged closest to a road surface of suspension arms. The lower arm 1 is substantially straightly formed by use of a sheet metal, its main part 101 has U-shaped sectional upper and lower half parts 1a and 1b, whose edges are mutually continuously overlapped, and connected and fixed by welding to form a closed sectional structure. A conical knock-in recessed part 13 including the jack contact part A is formed under the spring receiving part 105 of the main part 101, so that a jack attachment can be engaged without slippage. Further, a reinforcing bracket 17 is connected and fixed by welding to reinforce the rigidity around the recessed part. According to this, the durability of the suspension arm can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension arm for use in a vehicle suspension system, and more particularly to a suspension arm having a body for the suspension arm having a closed cross-sectional structure and having a jack contact portion used for jacking up.

[0002]

2. Description of the Related Art A suspension system for a vehicle includes a link mechanism for connecting a wheel to a vehicle body so as to be vertically movable, and a shock absorbing mechanism including a spring and a shock absorber for absorbing a fluctuation component of a road surface reaction force input through the wheel. With these functions, the impact received by the occupant on the vehicle body side is reduced, and the livability is improved. Such a suspension device includes a suspension arm such as a lower arm and a trailing arm in a link mechanism, and supports a wheel at the swinging end side of the suspension arm so as to be swingable.

Incidentally, it is assumed that the vehicle is jacked up at the time of repair or regular maintenance. in this case,
If the vehicle uses an independent suspension and the vertical stroke of the suspension is set to be relatively large, and the set point, which is the jack contact part for jacking up, is set to the side sill, In some cases, the lift amount is insufficient and the wheels cannot be separated from the floor. Therefore, a set point that is a jack contact portion is set on a suspension arm such as a lower arm or a trailing arm, thereby suppressing a spring displacement at the time of jacking up, preventing a suspension displacement of the suspension arm and the wheel with respect to the vehicle body, and Known are those that are easily separated from the floor.

[0004] For the above-mentioned suspension arm, a forged or cast suspension arm is used when priority is given to ensuring its strength, and a sheet metal suspension arm is used when priority is given to weight reduction. In order to set a set point, which is a jack contact portion, on a sheet metal suspension arm, a contact portion that engages with the jack attachment without displacement is formed on the downward surface of the suspension arm. For example, as disclosed in Japanese Utility Model Laid-Open Publication No. 7-31416, a cut is formed in the lower surface of a suspension arm having a closed cross-sectional structure,
As disclosed in Japanese Patent Publication No. 79, a plate-shaped reinforcing member having a downward edge is provided inside a downward U-shaped suspension arm. In these cases, the jack attachment meshes with the notch on the lower surface of the arm or the plate-like reinforcing member, and the vehicle body can be lifted via each suspension arm while restricting relative displacement.

[0005]

However, in the case where the suspension arm is made of sheet metal, setting the set point which is a jack contact portion for jacking up the suspension arm causes the following problem. That is, in the case of a suspension arm having a closed cross-section structure disclosed in Japanese Utility Model Laid-Open Publication No. Hei 7-31416, the cross-sectional width of the suspension arm is relatively narrow, and the body load is concentrated and applied when jacking up through the same. Forming the cuts in the same portion is problematic in securing durability. On the other hand,
In the case of a suspension arm having a downward U-shaped cross section disclosed in Japanese Patent No. 13479, when a vehicle load is applied to a part of the suspension arm through a plate-like reinforcing member during jacking-up, bending stress is applied to a joint portion between the suspension arm and the reinforcing member. Are concentrated, and also in this case, there is a problem in securing durability.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a suspension arm in which a jack contact portion for jacking up can be set without deteriorating the durability of a sheet metal suspension arm.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, the suspension arm has a main body having a closed cross-sectional structure, and in particular, a recess is formed on the lower surface of the main body. A reinforcing bracket is joined and fixed to the concave portion, and a jack contact portion for jack-up is formed on at least one of the reinforcing bracket and the concave portion. Here, after forming a concave portion on the lower surface of the main body having a closed cross-sectional structure, the reinforcing bracket is joined and fixed to the concave portion so that the wall surfaces around the concave portion can be prevented from displacing in the direction approaching each other, and the rigidity around the concave portion can be reduced. Can be strengthened. For this reason, the displacement of the jack attachment when the jack attachment abuts on the jack contact portion can be prevented, and in particular, the reinforcing bracket can prevent the wall displacement around the concave portion when the upward pressing force by the jack attachment acts, The durability of the suspension arm, which has a closed cross-sectional structure and has a jack contact portion, can be ensured.

In this case, in particular, when the jack attachment comes into contact only with the concave portion, the displacement of the jack attachment can be prevented by the reinforcing bracket, and further, when the concave groove formed in the jack attachment is engaged with the reinforcing bracket, The jack attachment can be more reliably prevented from slipping, and when the jack attachment's concave groove engages with the reinforcing bracket and a part of the jack attachment comes into contact with the recess, the jack attachment's shift can be more reliably prevented. The load can be dispersed and the durability of the suspension arm can be ensured.

Further, the reinforcing bracket may be provided in a direction crossing a longitudinal direction of the main body. In this case, the displacement in the direction intersecting with the longitudinal direction of the main body, which is originally apt to be displaced in the wall around the concave portion, is prevented by the reinforcing bracket provided in the concave portion in the direction intersecting with the longitudinal direction of the main body, The durability of the suspension arm having a closed cross-sectional structure can be further improved.

According to a second aspect of the present invention, in the suspension arm according to the first aspect, the reinforcing bracket has a bent portion which is joined and fixed to a bottom surface of the concave portion. In this case, the bent portion can form a jack contact portion, and the upward pressing force applied to the bent portion can be reliably dispersed in the bent portion. In this regard, the durability of the suspension arm having a closed cross-sectional structure can be further improved. .

[0011]

FIG. 1 shows a suspension device S having a lower arm 1 to which the suspension arm of the present invention is applied. The suspension device S employs a four-wheel independent suspension system, and includes a chassis member 11 (FIG. 3) in which a vehicle body (not shown) and a plurality of portions are integrally connected thereto.
) Is connected to the rear wheel 2 via a link mechanism S1 and a shock absorbing mechanism S2. Here, the shock absorbing mechanism S2 absorbs and reduces the reaction force fluctuation component from the road surface 3 input from the rear wheel 2, and includes a coil spring 4 and a shock absorber 5.

As shown in FIGS. 1 and 3, the link mechanism S1
Is provided with a knuckle 6 for pivotally supporting the rear wheel 2.
Connected to the vehicle body via two suspension arms. Note that five suspension arms including the lower arm 1, the upper arm 7, the toe control arm 8, and the trailing arm 9 are arranged in parallel between the knuckle 6 and the vehicle body. Lower arm 1 is lower boss 6 of knuckle 6
1 and the lower bending end 111 of the chassis member 11 are respectively pin-connected via rubber bushes (not shown). The upper arm 7 has a swing end at the upper boss 602 of the knuckle 6.
And a ball joint, and the bifurcated fulcrum end is pin-connected to the front extension 113 of the chassis member 11 via a rubber bush (not shown). The swinging end of the toe control arm 8 is connected to the front boss 603 of the knuckle 6 via a ball joint, and the fulcrum end is connected to the downward bracket 114 of the chassis member 11 by the rubber bush (not shown). Is done. The trailing arm 9 is pin-connected to an upper front boss (not shown) near the upper boss 602 of the knuckle 6 and a side member 12 via rubber bushes (not shown).

A jack contact portion A (see FIG. 2 (b)) for jack-up is formed on the lower arm 1 which is provided closest to the road surface 3 among the respective suspension arms of the suspension device S. ing. 1 and 2
As shown in FIGS. 4 (a) and 4 (b), the lower arm 1 has a substantially straight main part 101 made of sheet metal, a bifurcated swing end 102 which is one end thereof, and a cylindrical end which is the other end. Fulcrum end 103. The main portion 101 has upper and lower halves 1a and 1b having a U-shaped cross section, and these upper and lower protruding edges are continuously overlapped with each other.
It is formed so as to form a closed sectional structure by joining and fixing by welding. The swinging end 102 is formed at a portion where one side end of the lower half portion 1b is bifurcated and extended, and a lower boss 601 of the knuckle 6 is fitted between them, and each other is interposed via a rubber bush (not shown). It is configured to be pin-coupled. The fulcrum end 103 is a tubular body that is joined and fixed to the other end of the main part 101 by welding, and is configured to be pin-connected to the lower bent end 111 of the chassis member 11 via a bush (not shown).

The main portion 101 has a shock absorber mounting portion 104 near its swinging end 102, a spring receiving portion 105 for mounting the lower end of the coil spring 4 at a central portion, and a jack contact portion A below the spring receiving portion 105. Are formed respectively. The shock absorber mounting portion 104 includes a vertical wall portion near the swinging end 102 of the lower half portion 1b and a pair of pin holes h formed therein, via a pin (not shown) fitted in the pair of pin holes h. The lower end of the shock absorber 5 is pin-connected. Reference numeral 14 in FIG. 2A indicates a fitting hole of the shock absorber 5, and the upper end of the shock absorber 5 is attached to a side vertical wall plate 15 on the vehicle body side via a bracket 16. The spring receiving portion 105 is formed as a stepped annular surface in contact with the lower end of the coil spring 4 at the center of the upper half 1a, and has an upward opening b as a working port inside thereof. Here, the coil spring 4 is attached to a dish-shaped spring receiving portion 112 at a side end of the chassis member 11 whose upper end is integrally connected to the vehicle body.

The recess 13 is provided below the spring receiving portion 105 on the lower surface of the lower half portion 1b, and is substantially mortar-shaped when the lower surface of the lower half portion 1b is driven upward from below. The recess 13 is formed as a recess.
Is formed so that a jack attachment Ja, which will be described later, can be engaged with the lower arm 1 having a flat sectional structure without displacement. The recess 13 is formed with a bottom surface 131, an inclined side surface 132 around the bottom surface 131, and a downward opening c serving as a working opening. In particular, the reinforcing bracket 17 is joined and fixed by welding. The reinforcing bracket 17 is a vertical piece 17 provided in a width direction Y that is a direction intersecting the longitudinal direction of the main body 101.
1 and a bent extension portion 172 that is bent from the upper end of the vertical piece portion 171 and overlaps the bottom surface 131, both ends of the vertical piece portion 171 are on the inclined side surface 132 of the recess 13, and the bent portion 172 is formed on the bottom surface 131.
Respectively. The bent portion 172 welded to the bottom surface 131 forms a jack abutting portion A, and the area of contact with the top surface of the jack attachment J is ensured. Note that the vertical piece portion 17 located at a portion that does not face the jack contact portion A
1 can restrict the displacement of the jack attachment Ja that contacts the jack contact portion A.

Further, the vertical piece portion 171 is provided in the width direction Y of the main body 101, and the portions (the portions indicated by the symbol e in FIG. 4) of the inclined side surfaces 132 located in the width direction Y approach each other. It can function as a tension member for preventing displacement to m, and the rigidity around the concave portion can be enhanced. In addition,
The vertical piece portion 171 of the reinforcing bracket 17 only needs to be able to strengthen the rigidity around the concave portion.
May be provided in the recess 13 along a direction inclined by a predetermined amount α (see FIG. 2A), and both side ends thereof may be joined and fixed to each opposed portion of the inclined side surface 132 by welding. The suspension device S having the above-described lower arm 1 allows vertical movement while restricting the rear wheels 2 to be kept in a predetermined alignment state by the link mechanism S1 during normal running of the vehicle, and allows input from the road surface 3 by the shock absorbing mechanism S2. It operates to absorb and reduce the reaction force fluctuation component. In this case, the lower arm 1 swinging up and down at the swinging end together with the rear wheel 2 is a hollow straight body having a closed cross-sectional structure, so that sufficient strength can be maintained and durability can be secured despite being made of sheet metal. Moreover, the unsprung load can be reduced.

On the other hand, it is assumed that the vehicle is jacked up during its repair or regular maintenance. At this time, the jack J is provided immediately below the jack contact portion A including the bent portion 172 in the concave portion 13 of the lower arm 1, and when the jack J is lifted, the top surface of the jack attachment Ja contacts the jack contact portion A. And the vehicle body can be jacked up via the lower arm 1. Since the jack-up is performed in a state where the coil spring 4 and the rear wheel 2 are located above the lower arm 1, there is no possibility that the rear wheel 2 cannot be lifted due to the insufficient lift of the jack J.

In this case, even if the jack attachment Ja which comes into contact with the jack abutting portion A attempts to cause a displacement in accordance with the tilt displacement of the vehicle body, the displacement is prevented because it is in the concave portion 13. In addition, the displacement of the jack attachment Ja is reliably prevented by the inclined side surface 132, and the jack-up process can be easily performed. Further, when an upward pressing force P acts on the bottom surface 131 via the bent portion 172 forming the jack contact portion A, the lower arm 1
3 is displaced toward the center side. In particular, since the straight main portion 101 adopts a closed cross-sectional structure, the portion of the inclined side surface 132 located in the width direction Y (reference numeral in FIG. 4) e) tend to be largely displaced in the direction m approaching each other, but in this case, the displacement can be prevented by the vertical piece 171 provided along the width direction Y functioning as a tension member. The rigidity around 13 can be sufficiently enhanced, and the durability of the lower arm 1 can be ensured. Further, the pressing force P applied to the bent portion 172 can be reliably dispersed to the lower half portion 1b side including the bottom surface 131 by the function of the bent portion 172, and in this regard, the durability of the suspension arm having the closed cross-sectional structure can be further secured. .

In the lower arm 1 of FIG. 1, the bent portion 172 of the reinforcing bracket 17 in the concave portion 13 is set as the jack contact portion A. Instead, as shown in FIG. The portion 171 and the bent portion 172 may both be set as jack contact portions A. in this case,
The jack attachment Ja ′ has a concave groove g formed at the top thereof, and the top surface can be brought into contact with the bent portion 172 in a state where the concave groove g is engaged with the vertical piece 171 in the concave portion 13, and in response to the lift operation, The body can be jacked up. At this time, the displacement of the jack attachment Ja ′ meshing with the vertical piece 171 can be reliably prevented. In addition, even when the upward pressing force P acts on the bent portion 172 and the vertical piece 171, the displacement of the concave side 13 toward the center of the inclined side surface 132 is prevented by the vertical piece 171 functioning as a strut member. The pressing force P can be reliably dispersed to the lower half 1b side by the function of the bent portion 172, and the durability of the suspension arm having the closed cross-sectional structure can be further improved.

In the lower arm 1 shown in FIG. 5, the jack contact portion A is formed continuously over the vertical piece portion 171 and the bent portion 172 of the reinforcing bracket 17, but when the vehicle body weight is relatively small, 5, a jack attachment Ja "as shown by a two-dot chain line may be used. In this case, the groove g of the jack attachment Ja" is formed relatively shallow, and only the groove g is formed in the vertical piece 171. Only the meshing portion forms the jack contact portion A. In this case, substantially the same operation and effect as in FIG. 5 can be obtained.

The suspension device S having the lower arm 1 shown in FIG. 1 employs a four-wheel independent suspension system in which the rear wheel 2 and the knuckle 6 are connected to the vehicle body via five suspension arms. The suspension arm structure of the present invention may be applied to a lower arm or a trailing arm in a suspension device employing an independent suspension system. In these cases, the same operation and effect as those of the suspension arm structure in the suspension device S of FIG. 1 can be obtained. . Further, the suspension device S provided with the lower arm 1 in FIG. 1 has been described as the rear wheel 2, but the present invention is also applicable to a suspension arm in a front wheel suspension device. In these cases, the present invention is applied to a suspension arm close to the road surface. Thus, the same operation and effect as those of the suspension arm structure in the suspension device S of FIG. 1 can be obtained.

[0022]

According to the first aspect of the present invention, a concave portion is formed in the lower surface of the main body having a closed sectional structure, and the reinforcing bracket is joined and fixed to the concave portion, and the rigidity around the concave portion can be enhanced. The displacement of the jack attachment when the attachment abuts can be prevented, and in particular, the reinforcing bracket can prevent the wall displacement around the recess when the upward pressing force is applied by the jack attachment, and the jack has a closed cross-sectional structure The durability of the suspension arm for which the section is set can be ensured.

According to the second aspect of the present invention, the bending portion is formed on the reinforcing bracket and is joined and fixed to the bottom surface of the concave portion. In this case, the bent part can form a jack contact part, and the bent part can reliably disperse the upward pressing force applied to the bent part,
In this respect, the durability of the suspension arm having the closed cross-sectional structure can be further improved.

[Brief description of the drawings]

FIG. 1 is a cutaway side view of a main part of a suspension device having a lower arm to which a suspension arm according to an embodiment of the present invention is applied.

FIGS. 2A and 2B are enlarged views of a lower arm in FIG. 1, wherein FIG. 2A is a plan view and FIG.

FIG. 3 is a cutaway plan side view of a main part of the suspension device of FIG. 1;

FIG. 4 is a sectional view taken along line XX of FIG. 1;

FIG. 5 is an enlarged partial cross-sectional view of a main part of a modified example of the suspension device having the lower arm of FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 lower arm 101 main body 13 concave portion 131 bottom surface 132 inclined side surface 17 reinforcing bracket 171 vertical piece portion 172 bent portion A jack contact portion Y width direction which is a direction intersecting with the longitudinal direction

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Eiji F-term (reference) 333-8, Shiba 5-chome, Minato-ku, Tokyo 3D001 AA17 AA18 BA03 DA04

Claims (2)

[Claims] 1. A suspension arm having a body having a closed cross-sectional structure, comprising: a recess formed on a lower surface of the body; and a reinforcing bracket joined and fixed to the recess, and at least one of the reinforcing bracket and the recess. A suspension arm having a jack contact portion for jack-up on one side. 2. The suspension arm according to claim 1, wherein the reinforcing bracket has a bent portion which is joined and fixed to a bottom surface of the concave portion.