JP2018103970A - Suspension arm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve rigidity of a suspension arm while suppressing weight increase.SOLUTION: A sheet metal suspension arm 1 which has two connection points 1A,1C connected to a vehicle body side, and a connection point 1B connected to a wheel side includes: a principal plane part 10 including the three connection points 1A-1C and extending in a planar shape; a wall part 11 which is bent and formed in a direction crossing the principal plane part 10 from an outer marginal part extending between the adjacent three connection points 1A-1C in the principal plane part 10; and a reinforcement member 13 which is adjacently arranged at least in one of the three connection points 1A-1C, and connects the principal plane part 10 and the wall part 11 in a brace-like shape.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a suspension arm installed in a vehicle.

  The suspension arm (also referred to as a lower arm) is an arm member having two connection points connected to the vehicle body side and one connection point connected to the wheel side, to which a shock absorber and a bump stopper are attached. For example, a suspension arm has been proposed in which two plates are combined to form a closed cross section (see Patent Document 1).

  A suspension arm is also known in which a peripheral portion of a single plate is bent to form a U-shaped cross section for weight reduction. That is, a cross-sectional shape is copied by a main surface portion to which a shock absorber or the like is attached, a wall portion bent upward or downward from an outer edge portion of the main surface portion, and a flange portion formed by further bending the tip of the wall portion. It is a suspension arm that ensures rigidity by adopting the shape of

JP 2000-21329 A

  However, there is a portion where the flange portion cannot be formed depending on the shape of the suspension arm. For example, the vicinity of a connection point, the part where the curvature of a curve is large among the edge parts extended between connection points, etc. are mentioned. Since the cross-sectional shape is L-shaped at the portion where the flange portion does not exist, the rigidity is lower than that of the U-shaped portion at the cross-section. If there is a difference in rigidity in this way, a portion having low rigidity starts as a starting point and causes deformation or cracking. In addition, since a large load acts in the vicinity of the connection point, deformation and cracks are likely to occur unless high rigidity is secured.

  In order to increase the rigidity, it is also conceivable that the reinforcement is welded and fixed along the main surface portion of the suspension arm (arm upper in Patent Document 1) as in Patent Document 1, for example. However, such a structure that combines plate materials can increase the rigidity compared to the structure without reinforcement, but if higher rigidity is required, the reinforcement must be enlarged or thickened. However, since the weight increases, further improvement is desired.

  The suspension arm of the present invention has been devised in view of such problems, and an object thereof is to improve rigidity while suppressing an increase in weight. It should be noted that the present invention is not limited to these purposes, and is an operational effect derived from each configuration shown in the embodiment for carrying out the invention described later, and also has an operational effect that cannot be obtained by conventional techniques. It is.

  (1) The suspension arm disclosed herein is a sheet metal suspension arm having two connection points connected to the vehicle body side and a connection point connected to the wheel side, and includes the three connection points. At least one of the three connection points, a main surface portion formed in a planar shape, a wall portion bent in a direction intersecting the main surface portion from an outer edge portion extending between the connection points of the main surface portions, and And a reinforcing member that is arranged adjacent to and connects the main surface portion and the wall portion in a bracing manner.

(2) It is preferable that the suspension arm includes a flange portion that is bent inward from a leading edge at a predetermined position of the wall portion. In this case, it is preferable that the reinforcing member connects the portion of the wall portion where the flange portion does not exist and the main surface portion in a brace shape. In addition, it is preferable that the location where the flange portion does not exist is located in the vicinity of at least one of the three connection points.
(3) Further, the wall portion includes a bent portion formed with a curvature radius of a predetermined value or less in the vicinity of at least one of the three connection points, and the reinforcing member includes the bent portion and the main surface portion. Are preferably connected in braces.

  (4) The main surface portion extends from a front connection point located on the vehicle front side to a rear connection point located on the vehicle rear side among the two connection points connected to the vehicle body side. And a portion extending toward the connection point connected to the wheel side from the front connection point, and the reinforcing member is formed between the front connection point and the rear connection point. It is preferable to connect the site | part adjacent to the said front connection point among the said wall parts provided in and the said main surface part.

(5) The reinforcing member is a plate-like member, and the reinforcing member is linearly welded and fixed to each of the main surface portion and the wall portion, and the welded portion to the main surface portion is on the vehicle body side. It is preferable that it is provided in the linear form substantially parallel to the extending direction of the said wall part extended between these two connection points.
(6) It is preferable that the reinforcing member has a curved portion that is curved toward the main surface portion side.
(7) It is preferable that one end of the reinforcing member is fixed by welding to the main surface portion, the other end is fixed by welding to the wall portion, and a flat portion substantially parallel to the main surface portion.

  According to the disclosed suspension arm, it is possible to improve the rigidity of the suspension arm while suppressing the increase in weight by arranging the bracing reinforcement member. Thereby, the deformation | transformation (in-plane deformation | transformation, out-of-plane deformation | transformation) in the vicinity of a connection part and generation | occurrence | production of a crack can be suppressed.

It is a typical perspective view which shows the suspension arm and suspension cross member which concern on embodiment. It is a typical perspective view which shows the left suspension arm. It is a bottom view of the left suspension arm. (A) is a bottom view of the reinforcing member shown in FIG. 3, and (b) is a view showing a cross section of the main surface portion and the wall portion along the AA arrow cross-sectional view of FIG. 4 (a).

  A suspension arm as an embodiment will be described with reference to the drawings. The embodiment described below is merely an example, and there is no intention of excluding various modifications and technical applications that are not explicitly described in the following embodiment. Each configuration of the present embodiment can be implemented with various modifications without departing from the spirit thereof. Further, they can be selected as necessary, or can be appropriately combined. In the following description, the vehicle traveling direction is defined as the front, the opposite side is defined as the rear, and the left and right are determined based on the front. Moreover, let the direction of gravity be a downward direction, and let the opposite side be an upper direction. Furthermore, the center in the left-right direction of the vehicle is referred to as “inside”, and the outer side in the left-right direction of the vehicle is referred to as “outside”.

[1. Constitution]
FIG. 1 is a schematic perspective view showing a state in which a suspension arm 1 and a suspension cross member 2 (hereinafter referred to as “suscross 2”) according to the present embodiment are combined. The suspension arm 1 is made of sheet metal and has two connection points 1A and 1C connected to the vehicle body side and a connection point 1B connected to the wheel side. In this embodiment, two connection points 1A and 1C are connected to the suspension cross 2, and the connection point 1B is connected to the front wheel 3 via a knuckle (not shown).

  The suspension cross 2 connects the suspension arm 1 and a side member (vehicle body) (not shown), and is provided in a vehicle including an independent suspension type suspension device in which left and right wheels operate independently. The suspension cross 2 extends in the vehicle width direction between a pair of left and right side members extending in the vehicle front-rear direction, and is supported by the vehicle body by fixing both left and right ends to the side members. The side member is a member that constitutes the skeleton of the vehicle.

  The suspension device of this embodiment is a so-called strut suspension device, and is provided on the front wheel 3 as shown in FIG. The suspension device is supported by connecting the upper end of a coil spring (both not shown) containing a shock absorber to a spring house (vehicle body) (not shown). The suspension arm 1 is an element constituting the suspension device, and supports an axle (not shown).

  As shown in FIGS. 1 to 3, the suspension arm 1 of the present embodiment has arms extending from the connection point 1 </ b> A located on the front inner side (hereinafter also referred to as “front connection point 1 </ b> A”) to the rear and the outer side. It is substantially L-shaped when viewed from above. The other end of the arm 1C connected to the vehicle body side (hereinafter also referred to as “rear connecting point 1C”) is provided at the tip of the arm extending rearward, and the tip of the arm extending outward is provided. Is provided with a connection point 1B (hereinafter also referred to as “outer connection point 1B”) connected to the wheel side. 2 is a perspective view of the left suspension arm 1 as viewed from above and obliquely rearwardly outside, and FIG. 3 is a view (bottom view) of the left suspension arm 1 as viewed from the back side (downward).

  All of the three connection points 1A to 1C are connected to a connection destination (that is, the suspension cross 2 or the knuckle) via a bush (not shown). The bush is a shock-absorbing component in which an elastic body such as rubber or resin is enclosed between a metal outer cylinder and an inner cylinder, for example. In the present embodiment, the case where the axial direction of the front connection point 1A extends in the front-rear direction and the respective axial directions of the outer connection point 1B and the connection point 1C extend in the vertical direction is illustrated, but the axes of the connection points 1A to 1C The direction is not limited to this.

  As shown in FIGS. 2 and 3, the suspension arm 1 of the present embodiment includes a main surface portion 10 that is a main portion of the suspension arm 1, a wall portion 11 and a flange portion 12 for increasing the rigidity of the suspension arm 1, And a reinforcing member 13 for reinforcing the suspension arm 1. The main surface portion 10 is a portion formed in a planar shape including the three connection points 1A to 1C, and a shock absorber and a bump stopper (not shown) are attached thereto. Main surface portion 10 is formed in a substantially L shape by a portion extending from front connecting point 1A toward rear connecting point 1C and a portion extending from front connecting point 1A toward outer connecting point 1B. The The main surface portion 10 of the present embodiment has a circular body having a circular opening at the outer connection point 1B and the rear connection point 1C, and forming an outer cylinder of the bush at the front connection point 1A.

  The wall portion 11 is a portion that is bent in the direction intersecting the main surface portion 10 from the outer edge portion extending between the connection points in the main surface portion 10. That is, the wall 11 is provided between the front connection point 1A and the outer connection point 1B, between the front connection point 1A and the rear connection point 1C, and between the outer connection point 1B and the rear connection point 1C. The wall portion 11 of the present embodiment is bent and formed at a substantially right angle downward from the outer edge portion of the main surface portion 10.

  The flange portion 12 is a portion that is bent inward from a tip edge (a lower edge in the present embodiment) at a predetermined portion of the wall portion 11. The flange portion 12 of the present embodiment is provided at the leading edge of the wall portion 11 excluding the bent portion 11c immediately after the front connection point 1A, and is bent so as to be parallel to the main surface portion 10. As a result, the vertical cross-sectional shape is U-shaped at a portion (that is, a predetermined location) where the flange portion 12 is present, and the vertical cross-sectional shape is L-shaped at a portion where the flange portion 12 does not exist (that is, the bent portion 11c). The latter part (bending portion 11c) has a lower rigidity than the former part.

  The bent portion 11c is located in the vicinity of the front connecting point 1A, and is a portion of the wall portion 11 extending between the front connecting point 1A and the rear connecting point 1C that is bent with a radius of curvature equal to or less than a predetermined value (a portion where the bending is tight ). In other words, the flange portion 12 of the present embodiment is formed in a portion of the wall portion 11 where the radius of curvature is greater than a predetermined value. In addition, this predetermined value is set as a value which becomes the boundary of whether the flange part 12 can be shape | molded, for example in the bending process of sheet metal.

  The reinforcing member 13 is a plate-like member provided separately from the main surface portion 10, the wall portion 11, and the flange portion 12, is disposed adjacent to the front connection point 1 </ b> A, and straddles the main surface portion 10 and the wall portion 11. Connect to the shape. That is, as shown in FIG. 4B, the reinforcing member 13 connects them obliquely so as to form a space between the main surface portion 10 and the wall portion 11. 4A is an enlarged view (bottom view) of the reinforcing member 13 shown in FIG. 3, and FIG. 4B is a cross-sectional view taken along line AA in FIG. It is the figure which showed the cross section of the wall part 11 collectively.

  The reinforcing member 13 connects the portion of the wall portion 11 extending between the front connection point 1A and the rear connection point 1C adjacent to the front connection point 1A and the main surface portion 10 in a brace shape. The reinforcing member 13 of the present embodiment connects the bent portion 11c of the wall portion 11 (a portion where the flange portion 12 does not exist) and the main surface portion 10 in a brace shape. The reinforcing member 13 has one end 13 a fixed to the main surface portion 10 by welding and the other end 13 b fixed to the wall portion 11 by welding. In addition, the part shown with the code | symbol 14a and 14b in FIG. 3 and FIG.4 (b) is a welding part. In the reinforcing member 13 of the present embodiment, each end side of the one end 13 a and the other end 13 b is welded and fixed linearly to the main surface portion 10 and the wall portion 11. Further, as shown in FIG. 3, the welded portion 14a with respect to the main surface portion 10 is a straight line that is substantially parallel to the extending direction of the wall 11 extending between the front connecting point 1A and the rear connecting point 1C (symbol L in FIG. 3). It is provided in the shape.

  A force (load) is applied to the suspension arm 1 from the outer connection point 1B (front wheel 3), and a twisting force acts between the front connection point 1A and the rear connection point 1C, so that the suspension arm 1 is disposed adjacent to the front connection point 1A. A force also acts on the reinforcing member 13. The force acting on the reinforcing member 13 includes many components in the extending direction L of the wall portion 11 extending between the front connection point 1A and the rear connection point 1C. Therefore, if the weld line of the reinforcing member intersects with the extending direction L at an angle close to 90 degrees, the welded portion is likely to break. However, in this structure, since the welding part 14a with respect to the main surface part 10 of the reinforcement member 13 is provided substantially parallel to the extending direction L, the fracture | rupture in the welding part 14a is suppressed.

  Further, the reinforcing member 13 of the present embodiment is provided with a flat surface portion 13c substantially parallel to the main surface portion 10 between the one end 13a and the other end 13b. The flat surface portion 13 c is used for attaching a jig for aligning the reinforcing member 13 with respect to the main surface portion 10 and the wall portion 11 during the welding operation of the reinforcing member 13.

  In addition, the reinforcing member 13 of the present embodiment includes curved portions 13d and 13e that are curved in a convex shape toward the main surface portion 10 on each of the one end 13a side and the other end 13b side of the flat surface portion 13c. That is, the reinforcing member 13 is not linear between the one end 13a and the other end 13b, but is provided with a curved portion 13d, a flat surface portion 13c, and a curved portion 13e therebetween, and the longitudinal section has a stepped shape.

[2. effect]
(1) According to the suspension arm 1 described above, since the reinforcing member 13 that connects the main surface portion 10 and the wall portion 11 in a bracing manner is provided, compared with the case where the reinforcing member along the main surface portion 10 and the wall portion 11 is provided. Thus, the rigidity of the suspension arm 1 can be improved. Further, if the rigidity equivalent to that of the suspension arm 1 described above is obtained by providing a reinforcing member along the main surface portion 10 and the wall portion 11 (to join the surfaces), the reinforcing member becomes larger or thicker. Or increase the weight. In other words, according to the suspension arm 1 described above, high rigidity can be ensured while suppressing an increase in weight. As a result, deformation (in-plane deformation, out-of-plane deformation) and cracks in the vicinity of the front connecting portion 1A can be suppressed.

  In addition, since the reinforcing member 13 connects the main surface portion 10 and the wall portion 11 in a brace shape, the reinforcing member 13 can be easily attached. If a reinforcing member is attached in a bridging manner so as to connect the walls, a gap will be created between the wall and the reinforcing member due to variations in the manufacturing accuracy of the suspension arm and the reinforcing member, and it will not be installed properly. Or the mounting strength is weakened. However, according to the suspension arm 1 described above, even if the manufacturing accuracy varies, the reinforcing member 13 can be stably attached, so that sufficient attachment strength can be ensured.

  (2) In the suspension arm 1 described above, the flange portion 12 is provided at the leading edge of the wall portion 11 excluding the bent portion 11c. Thereby, in the site | part in which the flange part 12 was formed, since the main surface part 10, the wall part 11, and the flange part 12 become a U-shaped cross section, high rigidity can be ensured. Further, the portion where the flange portion 12 does not exist is lower in rigidity than the portion where the flange portion 12 is provided, but the reinforcing member 13 which connects the portion where the flange portion 12 does not exist and the main surface portion 10 in a brace form is provided. Therefore, the rigidity of the suspension arm 1 can be increased, and the occurrence of deformation and cracks can be suppressed. Furthermore, since the reinforcing member 13 is disposed only at a location where the flange portion 12 does not exist (that is, only at a necessary minimum portion), an increase in weight can be further suppressed.

  (3) When the axial direction of the front connection point 1A extends in the front-rear direction as in the suspension arm 1 described above, in the wall portion 11 between the front connection point 1A and the rear connection point 1C due to the design of the suspension arm 1 A bent portion 11c having a small curvature radius must be formed in the vicinity of the front connection point 1A. As described above, stress is likely to be concentrated on a portion (for example, the bent portion 11c) that is bent with a curvature radius equal to or less than a predetermined value, and breakage is likely to occur. However, according to the suspension arm 1 described above, since the reinforcing member 13 connects the bent portion 11c and the main surface portion 10 in a bracing manner, stress concentration can be avoided and damage can be prevented.

  (4) Moreover, when the main surface part 10 is formed in a substantially L shape like the suspension arm 1 described above, the load from the wheel side tends to concentrate on the front connection point 1A. On the other hand, since the reinforcing member 13 described above is disposed adjacent to the front connection point 1A having the highest possibility of damage among the three connection points 1A to 1C, it is possible to prevent the suspension arm 1 from being damaged. it can.

  (5) In the suspension arm 1 described above, the welded portion 14a to the main surface portion 10 of the reinforcing member 13 is linearly parallel to the extending direction L of the wall portion 11 extending between the front connection point 1A and the rear connection point 1C. Provided. For this reason, since the force concerning the welding part 14a can be received with a line | wire, the stress of the welding part 14a can be relieve | moderated and generation | occurrence | production of a fracture | rupture and a crack can be suppressed. In addition, since the welding part 14b with respect to the wall part 11 is provided along the wall part 11 extended between 1 A of front connection points, and 1 C of back connection points, generation | occurrence | production of a fracture | rupture and a crack is suppressed similarly.

(6) In the suspension arm 1 described above, the reinforcing member 13 has the curved portions 13d and 13e that are curved toward the main surface portion 10, so that the main surface portion 10 and the wall portion 11 are connected in a stretched state. Compared with the case where a simple reinforcing member is provided, the stress is less likely to concentrate on the one end 13a and the other end 13b. In other words, since the entire reinforcing member 13 can receive a force acting on the suspension arm 1, the rigidity of the suspension arm 1 can be improved.
(7) Moreover, since the reinforcement member 13 has the plane part 13c, a jig | tool can be attached using the plane part 13c. For this reason, the workability of positioning and welding of the reinforcing member 13 can be improved.

[3. Others]
Regardless of the embodiment described above, various modifications can be made without departing from the spirit of the invention. Each structure of embodiment mentioned above can be selected as needed, or may be combined suitably.
The shape and arrangement of the reinforcing member 13 described above are examples, and are not limited to those described above. For example, the reinforcing member 13 may be disposed adjacent to the other connecting portions 1B and 1C, or a plurality of reinforcing members 13 may be provided. Further, the reinforcing member 13 may be disposed at a portion where the rigidity is desired to be increased regardless of the presence or absence of the flange portion 12. That is, the position where the reinforcing member 13 is provided is not limited to the bent portion 11c. In the above-described embodiment, the case where the bent portion 11c is a portion where the flange portion 12 does not exist is illustrated, but these do not have to be the same portion.

  The portion of the flat surface portion 13c of the reinforcing member 13 may be curved or may be formed in a flat shape that is not parallel to the main surface portion 10. Further, the reinforcing member 13 may not have the curved portions 13d and 13e (for example, the main surface portion 10 and the wall portion 11 are connected in a straight line). Further, the reinforcing member 13 is not composed of a plate-shaped member, and may be configured by a bar or a cylindrical body. Further, the method of fixing the reinforcing member 13 to the main surface portion 10 and the wall portion 11 is not limited to welding, and may be adhesion, screwing, or the like. The reinforcing member only needs to connect at least the main surface portion 10 and the wall portion 11 in a brace shape.

  Further, the shape of the suspension arm 1 is not limited to that described above. For example, the wall portion 11 may be bent upward with respect to the main surface portion 10. The direction in which the wall portion 11 is bent may be a direction that intersects the main surface portion 10 and may not be an orthogonal direction. Moreover, the flange part 12 may be provided also in the bending part 11c, and the suspension arm 1 does not need to have the flange part 12 on the contrary.

1 suspension arm 1A front connection point 1B outer connection point 1C rear connection point 2 suspension cross (suspension cross member)
3 Front wheel 10 Main surface portion 11 Wall portion 11c Bending portion 12 Flange portion 13 Reinforcing member 13a One end 13b Other end 13c Planar portion 13d, 13e Curved portion 14a, 14b Welded portion L Extension of wall portion between front connection point and rear connection point direction

Claims (7)

A sheet metal suspension arm having two connection points connected to the vehicle body side and a connection point connected to the wheel side,
A main surface portion formed in a planar shape including the three connection points;
A wall portion formed by bending in a direction intersecting the main surface portion from an outer edge portion extending between the connection points in the main surface portion;
A suspension arm, comprising: a reinforcing member that is disposed adjacent to at least one of the three connection points and connects the main surface portion and the wall portion in a bracing manner. A flange portion that is bent inward from the leading edge at a predetermined location of the wall portion;
2. The suspension arm according to claim 1, wherein the reinforcing member connects the portion of the wall portion where the flange portion does not exist and the main surface portion in a brace shape. The wall portion includes a bent portion formed with a curvature radius of a predetermined value or less in the vicinity of at least one of the three connection points,
The suspension arm according to claim 1, wherein the reinforcing member connects the bent portion and the main surface portion in a bracing manner. The main surface portion extends from a front connection point located on the vehicle front side to a rear connection point located on the vehicle rear side, of the two connection points connected to the vehicle body side, and the front Formed in a substantially L shape by a portion extending from the connection point toward the connection point connected to the wheel side,
The said reinforcing member connects the site | part adjacent to the said front connection point among the said wall parts provided between the said front connection point and the said back connection point, and the said main surface part, It is characterized by the above-mentioned. The suspension arm according to any one of? The reinforcing member is a plate-like member, and the reinforcing member is linearly welded and fixed to each of the main surface portion and the wall portion,
The welded portion with respect to the main surface portion is provided in a linear shape substantially parallel to the extending direction of the wall portion extending between the two connection points on the vehicle body side. The suspension arm according to item 1. The suspension arm according to claim 1, wherein the reinforcing member has a curved portion that is curved toward the main surface portion side. The reinforcing member has a flat portion substantially welded to one end of the reinforcing member and fixed to the main surface portion, the other end is welded to the wall portion, and substantially parallel to the main surface portion. The suspension arm according to any one of 6.

Images