초록 ▼

When a load facing to the rear of a vehicle body acts on a knuckle mounting portion of an arm main body of a suspension arm, if the line of action of the load deviates vertically relative to the cross-sectional center of the arm main body, a moment that vertically deforms the arm main body occurs. H

When a load facing to the rear of a vehicle body acts on a knuckle mounting portion of an arm main body of a suspension arm, if the line of action of the load deviates vertically relative to the cross-sectional center of the arm main body, a moment that vertically deforms the arm main body occurs. However, since there are provided a first inclined projecting portion that is formed so as to bulge upward in an end part on a first vehicle body mounting portion side of a first bottom wall portion and has a height that gradually decreases in going from a first upper wall portion toward the second upper wall portion, and a second inclined projecting portion that is formed so as to bulge upward in an end part on the first vehicle body mounting portion side of a second bottom wall portion and has a height that gradually decreases in going from a third upper wall portion toward the second upper wall portion, it is possible to enhance the rigidity without increasing the weight of the arm main body, thus preventing deformation of the arm main body due to the load.

대표청구항 ▼

1. A suspension arm for a vehicle in which an arm main body formed by press forming a metal plate comprises a knuckle mounting portion on which a knuckle is mounted, a first vehicle body mounting portion that is provided inwardly of the knuckle mounting portion in a vehicle width direction and is mo

1. A suspension arm for a vehicle in which an arm main body formed by press forming a metal plate comprises a knuckle mounting portion on which a knuckle is mounted, a first vehicle body mounting portion that is provided inwardly of the knuckle mounting portion in a vehicle width direction and is mounted on a vehicle body, and a second vehicle body mounting portion that is provided toward a vehicle body rear side of the first vehicle body mounting portion and is mounted on the vehicle body, the suspension arm comprising: a first upper wall portion that extends substantially horizontally from the first vehicle body mounting portion to the second vehicle body mounting portion in a state in which the arm main body is mounted on the vehicle body;a second upper wall portion that extends substantially horizontally from the second vehicle body mounting portion to the knuckle mounting portion in a state in which the arm main body is mounted on the vehicle body;a third upper wall portion that extends substantially horizontally from the knuckle mounting portion to the first vehicle body mounting portion in a state in which the arm main body is mounted on the vehicle body;a first bottom wall portion that is at a position lower than the first and second upper wall portions and connects the first and second upper wall portions;a second bottom wall portion that is at a position lower than the second and third upper wall portions and connects the second and third upper wall portions,a first inclined projecting portion that is formed so as to bulge upward in an end part on the first vehicle body mounting portion side of the first bottom wall portion and has a height that gradually decreases in going from the first upper wall portion toward the second upper wall portion; anda second inclined projecting portion that is formed so as to bulge upward in an end part on the first vehicle body mounting portion side of the second bottom wall portion and has a height that gradually decreases in going from the third upper wall portion toward the second upper wall portion. 2. The suspension arm for a vehicle according to claim 1, wherein the first inclined projecting portion has a width that gradually decreases in going from the first upper wall portion toward the second upper wall portion. 3. The suspension arm for a vehicle according to claim 1, wherein the second inclined projecting portion has a width that gradually decreases in going from the third upper wall portion toward the second upper wall portion. 4. The suspension arm for a vehicle according to claim 1, wherein the arm main body comprises a third bottom wall portion that is connected at substantially the same height to the first and second bottom wall portions at a position sandwiched between the first and second inclined projecting portions, and a through hole is formed in the third bottom wall portion. 5. The suspension arm for a vehicle according to claim 1, wherein an outer face of the vehicle body mounting portion is fixed by welding to a weld part formed at an end edge of the arm main body, the weld part of the arm main body comprises a first weld part that extends substantially horizontally in a state in which the arm main body is mounted on the vehicle body, and second and third weld parts that extend downwardly from opposite ends of the first weld part, a distance between lower ends of the second and third weld parts being set larger than a distance between upper ends thereof. 6. The suspension arm for a vehicle according to claim 5, wherein the third weld part is bent in a direction in which the third weld part moves away from the second weld part while extending downwardly from a part that is connected to the first weld part. 7. The suspension arm for a vehicle according to claim 5, wherein the arm main body comprises the second vehicle body mounting portion to a rear of the vehicle body mounting portion as the first vehicle body mounting portion, a part sandwiched between the first and second vehicle body mounting portions of the arm main body comprises the first and second upper wall portions and first and second side wall portions formed by downwardly bending opposite side edges of the first and second upper wall portions, andthe first side wall portion is bent in a direction in which its first vehicle body mounting portion side moves away from the second side wall portion and is continuous to the third weld part. 8. The suspension arm for a vehicle according to claim 7, wherein a downwardly recessed recess is formed in a part in which the first upper wall portion and the first side wall portion are connected. 9. The suspension arm for a vehicle according to claim 1, wherein the arm main body comprises the knuckle mounting portion on which the knuckle is mounted and the first and second vehicle body mounting portions that are mounted on the vehicle body, and a concavo-convex portion is formed in a peripheral edge part of at least one of the knuckle mounting portion and the first and second vehicle body mounting portions. 10. The suspension arm for a vehicle according to claim 9, wherein the concavo-convex portion has a substantially polygonal shape or a substantially circular shape. 11. The suspension arm for a vehicle according to claim 9, wherein the arm main body comprises the first and second upper wall portions that extend in a substantially horizontal direction in a state in which the arm main body is mounted on the vehicle body, and first and second side wall portions that are formed by downwardly bending a peripheral edge of the first and second upper wall portions, the heights of the first and second side wall portions are made smaller in the vicinity of at least one of the knuckle mounting portion and the first and second vehicle body mounting portions in which the concavo-convex portion is formed than other parts, and the concavo-convex portion is formed on a border between the first and second upper wall portions and the first and second side wall portions. 12. The suspension arm for a vehicle according to claim 9, wherein the arm main body comprises the first and second upper wall portions that extend in a substantially horizontal direction in a state in which the arm main body is mounted on the vehicle body, first and second side wall portions that are formed by downwardly bending a peripheral edge of the first and second upper wall portions, and a lower wall portion that is formed by bending an end part that is not continuous to the first and second upper wall portions in at least one part of the first and second side wall portions, and the concavo-convex portion is formed at a position of a boundary between a part where the lower wall portion is provided and a part where the lower wall portion is not provided within the border between the first and second upper wall portions and the first and second side wall portions. 13. A suspension arm for a vehicle in which an arm main body that is formed by press forming a metal plate comprises a knuckle mounting portion on which a knuckle is mounted and a vehicle body mounting portion that is mounted on a vehicle body, and an outer face of the vehicle body mounting portion is fixed by welding to a weld part formed at an end edge of the arm main body, wherein the weld part of the arm main body comprises a first weld part that extends substantially horizontally in a state in which the arm main body is mounted on the vehicle body, and second and third weld parts that extend downwardly from opposite ends of the first weld part, a distance between lower ends of the second and third weld parts being set larger than a distance between upper ends thereof. 14. A suspension arm for a vehicle comprising an arm main body that is formed by press forming a metal plate, wherein the arm main body comprises a knuckle mounting portion on which a knuckle is mounted and first and second vehicle body mounting portions that are mounted on a vehicle body, and a concavo-convex portion is formed on a peripheral edge part of at least one of the knuckle mounting portion and the first and second vehicle body mounting portions.