JP7238220B2 - suspension arm - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension arm forming a part of a suspension system positioned at the rear of a vehicle.

A suspension arm (trailing arm) forming part of a suspension system (rear suspension) positioned at the rear of the vehicle has its front end supported by the vehicle body and its rear end supported by a cross beam (rear axle beam). When the vehicle is running, a load applied from the road surface to the cross beam through the wheels is transmitted to the vehicle body through the suspension arm. Generally, a suspension arm is a member extending in the vehicle front-rear direction. Therefore, the suspension arm is provided with means for preventing buckling in the longitudinal direction of the vehicle.

Patent Literature 1 discloses an example of a suspension arm. The suspension arm is provided with a bead (bulging portion 56 in Patent Document 1) extending in the vehicle front-rear direction and recessed in the vehicle width direction. The bead increases the section modulus of the cross section of the suspension arm perpendicular to the vehicle front-rear direction, thereby preventing the suspension arm from buckling in the vehicle front-rear direction. Further, the suspension arm is provided with a first support portion (first mounting position 15 in Patent Document 1) supported by the cross beam and a second support portion (second mounting position 17 in Patent Document 1). ing. The first support portion is positioned at the rear end of the suspension arm. The second support portion is positioned in front of the vehicle and above the first support portion in the suspension arm. In this case, the aforementioned bead passes below the vehicle from the second support portion and extends to the vicinity of the first support portion.

With such a configuration, when an impact force is transmitted from the wheels to the first support portion and the second support portion through the cross beam, such as when the vehicle runs over a curb, the second support portion is transferred to the suspension arm. Stress is concentrated in the area sandwiched between the part and the bead. Excessive stress concentration may cause the suspension arm to bend in the vehicle width direction. Therefore, a measure for alleviating the stress concentration is required.

JP 2019-64462 A

SUMMARY OF THE INVENTION An object of the present invention is to provide a suspension arm capable of alleviating the concentration of stress generated in the components of the suspension arm due to impact force.

A suspension arm provided by the present invention includes a main plate extending in the longitudinal direction of the vehicle, a front support portion positioned at the front end of the main plate and supported by the vehicle body, and a front support portion positioned at the rear end of the main plate and accommodating the axle. a first rear support portion supported by a cross beam mounted on the main plate; a second rear support portion positioned on the main plate in front of and above the vehicle relative to the first rear support portion and supported by the cross beam; The main plate is provided with a bead that extends in the vehicle front-rear direction and is recessed in the vehicle width direction, the bead includes a first edge that forms a rear edge of the bead and an upper edge of the bead, and a second edge connected to the upper end of the first edge, wherein the first edge is located in front of the vehicle relative to the second rear support portion, and when viewed along the vehicle width direction, positioned below the vehicle from an imaginary line connecting the center of the first rear support portion and the center of the second rear support portion; the second edge is connected to the upper end of the first edge; It is characterized by including an inclined edge inclined obliquely upward from the front to the rear of the vehicle, and an extension line of the inclined edge intersects the imaginary line when viewed along the vehicle width direction.

According to the suspension arm provided by the present invention, it is possible to alleviate the stress concentration generated in the constituent members of the suspension arm due to the impact force.

Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

It is a left view of the suspension arm concerning one embodiment of the present invention. FIG. 2 is a plan view showing the relationship between the suspension arm shown in FIG. 1 and a vehicle component; FIG. 2 is a cross-sectional view taken along line III-III of FIG. 1; FIG. 2 is a partially enlarged view of FIG. 1;

A mode for carrying out the present invention will be described with reference to the accompanying drawings.

A suspension arm A according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. The suspension arm A constitutes a part of a suspension system positioned at the rear of the vehicle. In the description of the suspension arm A, the object is a torsion beam suspension system for the right rear wheel. The suspension arm A has a main plate 10 , a front support portion 21 , a first rear support portion 22 and a second rear support portion 23 .

Here, for convenience of explanation, upr shown in these figures is the upward direction of the vehicle, dwn is the downward direction of the vehicle, fr is the forward direction of the vehicle, rr is the rearward direction of the vehicle, rh is the right direction of the vehicle, and lh is the left direction of the vehicle. . In the following description, when the terms "vertical" and "vertical" are used unless otherwise specified, they refer to the vertical directions of the vehicle, and when the terms "front and rear" are used without particular description, they refer to the front and rear directions in the longitudinal direction of the vehicle. The vehicle inner side in the vehicle width direction refers to the vehicle inner side in the vehicle width direction (vehicle left-right direction). The vehicle outward direction in the vehicle width direction refers to the vehicle outward direction in the vehicle width direction.

The main plate 10 constitutes the main part of the suspension arm A and shares the load such as the impact input from the wheel 40 shown in FIG. The main plate 10 is formed by molding a single steel plate. The main plate 10 extends in the longitudinal direction of the vehicle. As shown in FIGS. 1 and 2 , main plate 10 has inner surface 11 , outer surface 12 , bead 13 , flange 14 , first hole 151 , second hole 152 and third hole 153 .

As shown in FIG. 2, the inner surface 11 faces inward of the vehicle in the vehicle width direction. The outer surface 12 faces outward of the vehicle in the vehicle width direction. As shown in FIGS. 1 to 3, the bead 13 is provided on the main plate 10 so as to extend in the vehicle front-rear direction and be recessed from the inner surface 11 in the vehicle width direction. The bead 13 bulges the main plate 10 outward of the vehicle in the vehicle width direction. In the suspension arm A, the bead 13 has a trapezoidal shape when viewed in the longitudinal direction of the vehicle. As shown in FIGS. 1 to 3, the flange 14 protrudes from the peripheral edge of the inner surface 11 outwardly of the vehicle in the vehicle width direction, that is, in the direction in which the bead 13 is recessed. The flange 14 is provided over the entire peripheral edge of the main plate 10 . The first hole 151 is located at the front end of the main plate 10 . The second hole 152 is located at the rear end of the main plate 10 . The third hole 153 is located in front of the vehicle and above the second hole 152 . All of the first hole 151, the second hole 152 and the third hole 153 penetrate the main plate 10 in the vehicle width direction.

The front support portion 21, the first rear support portion 22 and the second rear support portion 23 are used to support the suspension arm A on the vehicle body and the cross beam 30 shown in FIG. The cross beam 30 accommodates an axle connected to the wheel 40 shown in FIG. The vehicle body and the cross beam 30 are connected to the suspension arm A by the front support portion 21 , the first rear support portion 22 and the second rear support portion 23 . Each of the front support portion 21, the first rear support portion 22 and the second rear support portion 23 includes an inner cylinder used for supporting the vehicle body or the cross beam 30, and an outer cylinder surrounding the inner cylinder in the axial direction of the inner cylinder. It is a vibration isolator comprising a cylinder and a rubber vibration isolator positioned between an inner cylinder and an outer cylinder.

As shown in FIG. 1 , the front support portion 21 is press-fitted into the first hole 151 of the main plate 10 . Therefore, the front support portion 21 is positioned at the front end of the main plate 10 . The front support portion 21 is supported by the vehicle body so as to swing in the vehicle width direction. The first rear support portion 22 is press-fitted into the second hole 152 of the main plate 10 . Therefore, the first rear support portion 22 is positioned at the rear end of the main plate 10 . The second rear support portion 23 is press-fitted into the third hole 153 of the main plate 10 . Therefore, the second rear support portion 23 is located on the main plate 10 in front of the vehicle and above the first rear support portion 22 . The first rear support portion 22 and the second rear support portion 23 are supported by the cross beam 30 via brackets (not shown) joined to the cross beam 30 shown in FIG. When the cross beam 30 moves in the vertical direction of the vehicle due to the load input from the wheels 40 shown in FIG.

As shown in FIGS. 1 and 4 , the bead 13 provided on the main plate 10 has a first edge 131 and a second edge 132 . The first edge 131 forms the trailing edge of the bead 13 among the peripheral edges of the bead 13 . In the suspension arm A, the first edge 131 extends along the upper side of the vehicle from its lower end to its upper end. As another configuration of the first edge 131, the first edge 131 may be inclined obliquely forward or obliquely rearward from its lower end to its upper end. The second edge 132 forms the upper edge of the bead 13 among the peripheral edges of the bead 13 . The second edge 132 is connected to the upper end of the first edge 131 .

As shown in FIGS. 1 and 4 , the first edge 131 is positioned forward of the vehicle relative to the second rear support portion 23 . Further, the first edge 131 is located below the vehicle from an imaginary line V connecting the center C1 of the first rear support portion 22 and the center C2 of the second rear support portion 23 when viewed along the vehicle width direction. . The second edge 132 includes an inclined edge 132A connected to the upper end of the first edge 131 and inclined obliquely upward from the front of the vehicle to the rear of the vehicle. The extension line E of the inclined edge 132A intersects the imaginary line V when viewed along the vehicle width direction.

In the suspension arm A, the width of the bead 13 (dimension in the vertical direction of the vehicle) gradually increases from the front of the vehicle to the rear of the vehicle in the section where the inclined edge 132A of the second edge 132 is provided. ing. As another configuration of the bead 13, the bead 13 may be bent obliquely upward so that the width of the bead 13 is uniform from the vehicle front to the vehicle rear in the section where the inclined edge 132A is provided.

Next, the effects of the suspension arm A will be described.

The suspension arm A includes a main plate 10, a first rear support portion 22 positioned at the rear end of the main plate 10, and a second rear support portion 23 positioned in front of the vehicle and above the first rear support portion 22 on the main plate 10. and The main plate 10 is provided with a bead 13 extending in the vehicle front-rear direction and recessed in the vehicle width direction. The bead 13 has a first edge 131 forming a rear edge and a second edge 132 forming an upper edge of the bead 13 and connected to the upper end of the first edge 131 . The first edge 131 is positioned forward of the vehicle relative to the second rear support portion 23 . In addition, when viewed along the vehicle width direction, the first edge 131 is positioned below the vehicle from an imaginary line V connecting the center C1 of the first rear support portion 22 and the center C2 of the second rear support portion 23. do. As a result, a first high stress area 51 (see FIG. 4) is generated in the main plate 10 due to the impact force input to both the first rear support portion 22 and the second rear support portion 23 from the wheel 40 shown in FIG. becomes more extensive. Here, the first high stress region 51 refers to a region in which relatively high stress is distributed among the stresses generated in the main plate 10 due to the impact force. The wider first high stress zone 51 distributes the stress therein and reduces the maximum stress.

Further, in the suspension arm A, the second edge 132 of the bead 13 includes an inclined edge 132A that connects to the upper end of the first edge 131 of the bead 13 and that is inclined upward from the front of the vehicle to the rear of the vehicle. The extension line E of the inclined edge 132A intersects the imaginary line V when viewed along the vehicle width direction. As a result, when viewed along the vehicle width direction, the extension line E passes through the second rear support portion 23 or its vicinity. The reaction force of the impact force input to the first rear support portion 22 acts on the second rear support portion 23 . At the same time, stress is generated in the main plate 10 by the reaction force. Let the area|region where relatively high stress is distributed among the said stress be the 2nd high stress area 52 shown in FIG. By adopting this configuration, the stress distributed in the second high stress region 52 is easily transmitted to the bead 13 via the inclined edge 132A. Therefore, the maximum stress in the second high stress area 52 can be reduced. As described above, according to the suspension arm A, it is possible to alleviate the stress concentration occurring in the constituent members (the main plate 10) of the suspension arm A due to the impact force.

The suspension arm A constitutes a part of the suspension system for the right rear wheel. However, the present invention can also be applied to a suspension arm that constitutes a part of the suspension system for the left rear wheel.

The invention is not limited to the embodiments described above. The specific configuration of each part of the present invention can be changed in various ways.

A: Suspension arm 10: Main plate 11: Inner surface 12: Outer surface 13: Bead 131: First edge 132: Second edge 132A: Inclined edge 14: Flange 151: First hole 152: Second hole 153: Third hole 21: Front support part 22: First rear support part 23: Second rear support part 30: Cross beam 40: Wheel 51: First high stress area 52: Second high stress area C1, C2: Center V: Virtual line E: Extension line

Claims (1)

a main plate extending in the longitudinal direction of the vehicle;
a front support portion positioned at the front end of the main plate and supported by the vehicle body;
a first rear support portion positioned at the rear end of the main plate and supported by a cross beam in which an axle is accommodated;
a second rear support portion positioned in front of the vehicle and above the first rear support portion in the main plate and supported by the cross beam;
The main plate is provided with a bead extending in the vehicle front-rear direction and recessed in the vehicle width direction,
The bead has a first edge that forms the trailing edge of the bead and a second edge that forms the upper edge of the bead and is connected to the upper end of the first edge,
The first edge is located forward of the vehicle relative to the second rear support portion, and is positioned between the center of the first rear support portion and the center of the second rear support portion when viewed along the vehicle width direction. and located below the vehicle from the virtual line connecting
The second edge includes an inclined edge connected to the upper end of the first edge and inclined obliquely upward from the front of the vehicle to the rear of the vehicle,
A suspension arm, wherein an extension line of the inclined edge intersects the imaginary line when viewed along the vehicle width direction.

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