JP2004322877A - Suspension arm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension arm capable of preventing interference with an upper tie rod when it is deformed by an input of a shock load. <P>SOLUTION: In the suspension arm 31, one end is supported by a vehicle body side and extended to the outside of the vehicle, the other end is lower of the tie rod 26 supporting wheels and transmitting control force to the wheels, and at least one part is provided in the position overlapped with the tie rod when seen from the top face. A bending promotion part is formed bending downwards of the vehicle in inputting the shock load from the other end side by downward curving. The bending promotion part is formed by comparing the rigidity of the upper part of the suspension arm with that of the lower part of the suspension arm and lowering it. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a suspension arm that supports wheels.
[0002]
[Prior art]
As a technique relating to a suspension device for reducing an impact inputted from a road surface via wheels during running of a vehicle, Patent Literature 1 discloses an outer suspension arm having one end supported by a vehicle body-side member and the other end rotatably supporting a wheel. The arm has an open section with the web height gradually decreasing from both ends toward the center toward the center, and the neutral axis of the second moment of area in the horizontal direction of the open section at the approximate center of the outer arm is connected to the bush. By offsetting above the imaginary line connecting the center and the center of the axle, the outer arm is buckled and deformed when an impact load is input to absorb the impact energy, and the direction of this deformation is always constant upward. It has been disclosed.
[0003]
[Patent Document 1]
Published Japanese Utility Model Application No. 2-16305
[Problems to be solved by the invention]
However, in the technique described in Patent Document 1, as shown in FIG. 10, a tie rod 1 that transmits a steering force to a wheel is located above the suspension arm 2 and at least partially overlaps with the suspension arm 2 in a top view. When the suspension arm 2 is deformed to the upper side of the vehicle as shown by a dashed line in the figure when an impact load is input as shown by an arrow F in the figure, the deformed suspension arm 2 and the tie rod 1 interferes with each other, and the direction of the wheels becomes a direction not intended by the driver, which may cause a secondary disaster.
[0005]
Therefore, in view of the above problems, it is an object of the present invention to provide a suspension arm which is not likely to interfere with an upper tie rod when deformed by input of an impact load.
[0006]
[Means for Solving the Problems]
A suspension arm according to a first aspect of the present invention for solving the above-mentioned problems is a suspension arm having one end supported on the vehicle body side and extending outside the vehicle and supporting the wheel at the other end, and transmitting a steering force to the wheel. The suspension arm provided below the tie rod and at a position where at least a part of the tie rod overlaps with the tie rod in a top view, the vehicle has a bending promoting portion that bends downward in the vehicle when an impact load is input from the other end. It is characterized by the following.
[0007]
Further, a suspension arm according to a second aspect of the present invention is the suspension arm according to the first aspect of the present invention, wherein the bending promoting portion is formed by being bent downward.
[0008]
A suspension arm according to a third aspect of the present invention is the suspension arm according to the first aspect of the present invention, wherein the bending acceleration portion is formed by lowering the rigidity of the upper part compared with the rigidity of the lower part.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0010]
FIG. 1 is a side view showing a device configuration of a suspension arm according to an embodiment of the present invention, FIG. 2 is a top view showing a device configuration of the suspension arm, FIG. 3 is a top view of the suspension arm, and FIG. 3A is a view taken in the direction of the arrow A in FIG. 3, FIG. 4B is a view taken along the line BB in FIG. 3, and FIG. 5 is an enlarged cross-sectional view taken along the line CC in FIG. 6 to 9 are cross-sectional views showing other examples of the configuration of the suspension arm.
[0011]
As shown in FIGS. 1 and 2, a steering device 22 and a suspension device 23 are provided near a wheel (front wheel) 21 of the vehicle.
[0012]
The steering device 22 houses a steering shaft 24 to which a steering wheel (not shown) is coupled at the upper end, a gear such as a rack and pinion, and a steering gear box 25 to which the input side is coupled to the lower end of the steering shaft 24, and one end. Has a tie rod 26 connected to the output side of the gear box 25 and extending outward from the vehicle, and a knuckle arm 28 connected to the other end of the tie rod 26 via a connecting portion 27. The wheel 21 is fixed to 28.
[0013]
Therefore, when the driver operates and rotates the steering wheel, this rotational force (steering force) is transmitted to the knuckle arm 28 via the steering shaft 24, the steering gear box 25 and the tie rod 26, and as a result, the knuckle arm 28 At the same time, the wheels 11 are steered.
[0014]
On the other hand, the suspension device 23 is configured to include a suspension arm 31, which is a lower arm, a shock absorber 32, a spring (not shown), and the like. The suspension arm 31 supports the wheels 21 and alleviates the impact from the road surface with a spring. In addition, the vibration is absorbed by the shock absorber 32.
[0015]
Here, the configuration of the suspension arm 31 will be described in detail with reference to FIGS.
[0016]
As shown in FIGS. 1 to 3, the suspension arm 31 has an upper member 31 </ b> A and a lower member 31 </ b> B integrally joined by welding, and the suspension arm main body 31 </ b> C has a bow-like shape curved toward the vehicle body side in a top view. It has a shape. In the middle of the suspension arm body 31C, there is formed a suspension arm branch 31D branched from the suspension arm body 31C and extending inward (to the vehicle body). The suspension arm 31 has a first vehicle body-side mounting portion 31C-1 at one end of the suspension arm main body portion 31C supported by the cross member 33 of the vehicle body and extends outward from the vehicle. The wheel 11 is supported by the wheel-side mounting portion 31C-2. The second vehicle body-side mounting portion 31D-1 at the end of the suspension arm branch portion 31D is supported by the cross member 33 of the vehicle body at a position closer to the front of the vehicle than the first vehicle body-side mounting portion 31C-1.
[0017]
More specifically, the first vehicle body-side mounting portion 31C-1 is provided with a bush 31a containing rubber, and is mounted on the vehicle body side (cross member 33) via the bush 31a so as to be rotatable around a vertical axis. Have been. The second vehicle-body-side mounting portion 31D-1 has a cylindrical portion 31c that opens in the front-rear direction of the vehicle, and extends around the horizontal axis extending in the vehicle front-rear direction toward the vehicle body (cross member 33) via the cylindrical portion 31c. Is mounted so as to be rotatable. The wheel-side mounting portion 31C-2 is provided with a ball joint socket 31b, and is rotatably mounted on the wheel 21 (knuckle arm 28) via the socket 31b.
[0018]
Moreover, the suspension arm 31 is provided below the tie rod 26 that transmits the steering force to the wheels 11 and at a position where the suspension arm 31 partially overlaps the tie rod 26 when viewed from above.
[0019]
For this reason, as shown in FIG. 1, the suspension arm 31 has a portion 31E close to the tie rod 26, that is, a portion 31E from the branch portion of the suspension arm branch portion 31D to the first vehicle body side mounting portion 31C-1 in the suspension arm body portion 31C. Is bent downward, so that when an impact load is input from the other end side as shown by an arrow F in FIGS. 1 and 2 (for example, when the wheel 11 strongly collides with a curb or the like). As shown by a dashed-dotted line in FIG. 1, a bending promoting portion (hereinafter, simply referred to as a bending promoting portion) is formed in which the suspension arm 31 bends downward in the vehicle.
[0020]
As shown in FIG. 4, a portion from the branch portion to the wheel-side mounting portion 31C-2 of the suspension arm body 31C is formed substantially horizontally (substantially linearly).
[0021]
As shown in FIG. 5, the upper member 31A of the suspension arm 31 has a U-shaped cross section and the opening side is downward, and the lower member 31B has a U-shaped cross section and the opening side is upward. By connecting the upper and lower members 31A and 31B, the cross-sectional shape of the entire suspension arm 31 is rectangular (R-shaped). Moreover, since the bending propulsion portion 31E is curved downward, the center point of the first vehicle-body-side mounting portion 31C-1 is point D, and the wheel-side mounting portion 31C-2, as shown in FIGS. Is a point E and a center point of the second vehicle body side attachment portion 31D-1 is a point F, as shown in FIG. 5, the cross-sectional center P is the point D, E, and the point where the impact load is input. It is located below the position of the virtual DEF plane including F.
[0022]
As described above, according to the suspension arm 31 of the present embodiment, the suspension arm 31 is bent downward when the impact load is input from the other end of the suspension arm 31 by forming the bending acceleration portion. Interference between the tie rod 31 and the tie rod 26 can be prevented, and safety is improved. In addition, it is known that the toe change of the wheel when the wheel strokes up and down is linear, the operability is better, and it is known that the lower the vertical position of the steering gear box is, the better the linearity of the toe change is. . On the other hand, in the present embodiment, the position of the tie rods can be arranged below and the steering gear box can be arranged relatively below by the amount of bending of the suspension arm, so that the toe change of the wheels can be further reduced. It is close to linear characteristics and operability is improved.
[0023]
Further, in the present embodiment, since the bending promotion portion is formed by bending the suspension arm 31 downward, the bending promotion portion can be formed with a relatively simple configuration.
[0024]
In addition, it is not always necessary to bend downward, and the bending promoting portion may be formed by another configuration.
[0025]
For example, the bending promoting portion may be formed by making the rigidity of the upper part (upper member 31A) of the suspension arm 31 smaller than the rigidity of the lower part (lower member 31B). In this case, the suspension arm 31 can be more reliably bent to the lower side of the vehicle body when the impact load is input.
[0026]
Alternatively, the center of the cross section of the cross section of the suspension arm 31 is located below the DEF plane, which is a plane connecting the mounting portion of the suspension arm 31 to the wheel side and the mounting portion of the suspension arm 31 to the vehicle body. A bending promoting portion may be formed. For example, the cross-sectional shape is as shown in FIGS. Also in this case, the suspension 31 can be bent toward the lower side of the vehicle body when the impact load is input, and the bending promoting portion can be formed with a relatively simple configuration. 6 to 9 show a cross section at a position corresponding to the cross section of FIG. 5, at least a part of the suspension arm 31 may have a cross sectional shape as shown in FIGS.
[0027]
More specifically, in the suspension arm 31 of FIG. 6, the upper member 31A has a trapezoidal cross section, and the lower member 31B has a U-shaped cross section on the opening side. , 31B are combined to form a generally convex cross-sectional shape. As described above, in the suspension arm 31 shown in FIG. 6, by making the cross section substantially convex, the area on the lower side is made larger than that on the upper side, and the center P of the cross section is located below the DEF plane, so that the folding A music promoting part is formed.
[0028]
In the suspension arm 31 of FIG. 7, the cross section of the upper member 31A is formed in an M shape by forming an arc-shaped concave portion 31A-1 at the center in the width direction, and the cross section of the lower member 31B is formed in the center in the width direction. The upper and lower members 31A and 31B are joined together to form a cross-sectional shape that is curved downward in its entirety by forming an arc-shaped convex portion 31B-1 in the portion. ing. As described above, in the suspension arm 31 of FIG. 7, the cross section is curved downward, so that the area of the lower side is larger than that of the upper side, and the center P of the cross section is located below the DEF plane. Thereby, the bending promoting portion is formed. In the suspension arm 31 shown in FIG. 7, the rigidity of the suspension 31 itself can be made relatively high.
[0029]
In the suspension arm 31 of FIG. 8, the cross section of the upper member 31A is formed in an M-shape by forming an inverted trapezoidal concave portion 31A-2 at the center in the width direction, and the cross section of the lower member 31B is formed on the opening side. The upper and lower members 31A and 31B are combined to form a generally concave cross-sectional shape. As described above, in the suspension arm 31 of FIG. 8, the cross section is substantially concave, so that the lower area is larger than the upper area, and the center P of the cross section is located below the DEF plane. A music promoting part is formed. Further, in the suspension arm 31 shown in FIG. 8, the rigidity of the suspension 31 itself can be made relatively high.
[0030]
In the suspension arm 31 of FIG. 9, the upper member 31A is formed in an M-shape by forming an inverted trapezoidal concave portion 31A-3 at the center in the width direction, and the lower member 31B is formed in a cross section in the width direction. A concave portion 31B-2 having a rectangular shape and a lower depth than the concave portion 31A-3 is formed at the center portion, and is formed in an inverted M shape. These upper and lower members 31A and 31B are joined to form a substantially H-shaped portion. It has a cross-sectional shape. As described above, in the suspension arm 31 of FIG. 9, the cross section of the lower recess 31 </ b> B- 2 is substantially H-shaped with a shallower bottom than the upper recess 31 </ b> A- 3, so that the lower area is smaller than the upper area. The bending promoting portion is formed by enlarging the area and positioning the cross-sectional center P below the DEF plane. In the suspension arm 31 shown in FIG. 9, the rigidity of the suspension 31 itself can be made relatively high.
[0031]
【The invention's effect】
As described above in detail with the embodiments of the present invention, according to the suspension arm of the first invention, one end is supported on the vehicle body side and is extended outside the vehicle, and the other end supports the wheel. An impact load input from the other end side of a suspension arm provided at a position below a tie rod transmitting steering force to the wheel and at least partially overlapping the tie rod in a top view. The suspension arm is sometimes bent to the lower side of the vehicle, so that the suspension arm is bent to the lower side of the vehicle when an impact load is input from the other end of the suspension arm, thereby preventing interference between the suspension arm and the tie rod. Can improve safety.
[0032]
According to the suspension arm of the second aspect of the present invention, in the suspension arm of the first aspect of the present invention, since the bending promoting portion is formed by being bent downward, the bending is made with a relatively simple configuration. An accelerating portion can be formed.
[0033]
Further, according to the suspension arm of the third invention, in the suspension arm of the first invention, the bending acceleration portion is formed by lowering the rigidity of the upper portion as compared with the rigidity of the lower portion. At the time of input, the suspension arm can be more reliably bent to the lower side of the vehicle body.
[Brief description of the drawings]
FIG. 1 is a side view showing a device configuration of a suspension arm portion according to an embodiment of the present invention.
FIG. 2 is a top view showing a device configuration of the suspension arm portion.
FIG. 3 is a top view of the suspension arm.
4A is a view in the direction of arrow A in FIG. 3, and FIG. 4B is a view in the direction of arrow BB in FIG.
FIG. 5 is an enlarged cross-sectional view taken along line CC of FIG. 3;
FIG. 6 is a sectional view showing another configuration example of the suspension arm.
FIG. 7 is a sectional view showing another configuration example of the suspension arm.
FIG. 8 is a sectional view showing another configuration example of the suspension arm.
FIG. 9 is a sectional view showing another configuration example of the suspension arm.
FIG. 10 is an explanatory view showing a state of interference with a tie rod when a conventional suspension arm is deformed.
[Explanation of symbols]
Reference Signs List 21 Wheel 22 Steering device 23 Suspension device 24 Steering shaft 25 Steering gear box 26 Tie rod 27 Connecting portion 28 Knuckle arm 31 Suspension arm (lower arm)
31A Upper member 31A-1, 31A-2, 31A-3 Recess 31B Lower member 31B-1 Convex portion 31B-2 Recess 31C Suspension arm main body 31C-1 First vehicle body side mounting portion 31C-2 Wheel side mounting portion 31D Suspension Arm branch part 31D-1 Second vehicle body-side mounting part 31E Part from branch part to first vehicle body-side mounting part (bending promoting part)
31a bush 31b socket 31c cylindrical portion 32 shock absorber 33 cross member

Claims (3)

A suspension arm having one end supported on the vehicle body side and extending outwardly of the vehicle and supporting the wheel at the other end, the suspension arm being below the tie rod that transmits steering force to the wheel, and having the tie rod in a top view. In the suspension arm provided at a position where at least a part overlaps,
A suspension arm, wherein the suspension arm includes a bending promoting portion that bends toward a vehicle lower side when an impact load is input from the other end side. The suspension arm according to claim 1, wherein the bending promoting portion is formed by being bent downward. The suspension arm according to claim 1, wherein the bending acceleration portion is formed by lowering rigidity of an upper portion as compared with rigidity of a lower portion.

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