Method of manufacturing a front lower suspension arm of a motor vehicle

Abstract

The invention relates to a method for manufacturing front lower suspension arms (16, 16') of a motor vehicle.It comprises the following steps: a first longitudinal part (20) is provided having two opposite first ends (26, 28), two opposite first faces (30, 32) defining a thickness, two opposite edges (34, 36) and a transverse light (46); a second longitudinal part (22) is provided having two opposite second ends (38, 40) and two opposite second faces (42, 44); one of said two second ends (38) is engaged through said transverse light (46), so that one of said two first faces (30) is oriented on the same side as one of said two second faces (42) to form a left lower suspension arm (16), or conversely to form a right lower suspension arm (16'); and, said one of said two second ends (38) and said one of said two first ends (26) are secured. Figure to be published with the abstract: Fig. 2.

Description

Title of the invention: Method for manufacturing a front lower suspension arm of a motor vehicle

[0001] The present invention relates to a method of manufacturing a front lower suspension arm of a motor vehicle.

[0002] Also, it also relates to front lower suspension arms obtained in accordance with the method.

[0003] The front lower suspension arms are among the essential elements of pseudo-McPherson type suspensions, commonly implemented on motor vehicles.

[0004] They are mounted articulated on the front cradle of the vehicle, on the right and on the left, and they receive at their end a wheel support or spindle.

[0005] More specifically, each lower suspension arm comprises a front branch generally pivotally mounted along a longitudinal axis of the vehicle at the front of the cradle, a rear branch articulatedly mounted at the rear of the cradle and a lateral branch joining a steering knuckle. The front branch extends in line with the lateral branch, while the rear branch usually extends in an arc towards the rear.

[0006] Accordingly, it is necessary to design a right lower suspension arm and a left lower suspension arm.

[0007] They are made from a main shell stamped from a steel plate and an additional reinforcement piece welded inside the shell. In addition, a sleeve is advantageously welded to the end of the front branch so that it can be pivotally mounted on the cradle.

[0008] The rear branch has a circular recess having an axis substantially parallel to that of the socket, while the lateral branch is equipped with a device forming a ball joint center.

[0009] Thus, the left front lower arm requires the stamping of two different left front parts from those of the right front lower arm.

[0010] Also, a problem which arises and which the present invention aims to solve is to provide front left and front right lower arms which are simpler to manufacture and consequently less expensive.

[0011] In order to solve this problem, there is proposed, according to a first object, a method for manufacturing front lower suspension arms of a motor vehicle comprising the following steps: a first longitudinal part is provided having, on the one hand, two first opposite ends and two first opposite faces defining a thickness, and on the other hand, two opposite edges and a light transverse cut made in the thickness of one of said two first ends and opening into said two opposite edges; a second longitudinal piece is provided having two opposite second ends and two opposite second faces; one of said two second ends is engaged through said transverse light, so that one of said two first faces is oriented on the same side as one of said two second faces to form a left lower suspension arm, or so that said one of said two first faces is oriented on the side opposite to said one of said two second faces to form a right lower suspension arm; and, said one of said two second ends and said one of said two first ends are secured, while said second and first longitudinal pieces are connected together by means of a connecting rod forming a triangle.

[0012] Thus, a characteristic of the invention lies in the implementation of only three parts to produce a right lower suspension arm or a left lower suspension arm. In this way, the number of different elements to be implemented for the two lower front suspension arms is reduced and consequently, the manufacturing costs are reduced.

[0013] Furthermore, these different elements have simple elementary shapes, as will be explained in more detail in the remainder of the description, and they are capable of being manufactured with inexpensive industrial means compared to those necessary for the manufacture of lower arms according to the prior art.

[0014] Also, according to the invention, said one of said two second ends and said one of said two first ends are advantageously secured by welding. Thus, said one of said two second ends engaged in the transverse lumen of the first part is partially secured thereto, and thanks to the welding carried out between the two parts, they are completely secured to one another.

[0015] According to the invention, said second and first longitudinal parts are preferably connected together by welding by means of a connecting rod forming a triangle. Thanks to the connecting rod, the rigidity of the lower suspension arm is improved.

[0016] According to the invention, a metal plate is advantageously stamped to provide said first and second longitudinal parts. Thus, the plate can also be simultaneously cut to obtain the parts. They are thus obtained economically.

[0017] According to a particularly advantageous characteristic of the invention, a first longitudinal part is provided having a first plane of symmetry intersecting said first longitudinal part between said two first opposite faces. In this way, and as will be explained in more detail in the remainder of the description, the first longitudinal piece can be turned 180° to make the other lower suspension arm.

[0018] Also, and according to the invention, a second longitudinal part is advantageously provided having a second plane of symmetry intersecting said second longitudinal part perpendicular to said two second opposite faces. In this way, the second longitudinal part can be implemented in one or other of the lower suspension arms.

[0019] According to another object, there is provided a lower front suspension arm of a motor vehicle obtained in accordance with the method according to the invention and as described above.The lower suspension arm comprises: a first longitudinal part having, on the one hand, two first opposite ends and two first opposite faces defining a thickness, and on the other hand, two opposite edges and a transverse light made in the thickness of one of said two first ends and opening into said two opposite edges; a second longitudinal part having two second opposite ends and two second opposite faces, one of said two second ends being engaged through said transverse light to secure them, so that one of said two first faces is oriented on the same side as one of said two second faces to form a left lower suspension arm; and, a connecting rod for connecting said second and first longitudinal parts together to form a triangle.

[0020] Also, a right lower suspension arm is provided, obtained in accordance with the method described above. It comprises: a first longitudinal part having, on the one hand, two first opposite ends and two first opposite faces defining a thickness, and on the other hand, two opposite edges and a transverse opening made in the thickness of one of said two first ends and opening into said two opposite edges; a second longitudinal part having two second opposite ends and two second opposite faces, one of said two second ends being engaged through said transverse opening to secure them, so that said one of said two first faces is oriented on the side opposite to said one of said two second faces to form a right lower suspension arm; and, a connecting rod for connecting said second and first longitudinal parts together to form a triangle.

[0021] The two parts are joined by welding for both the right lower suspension arm and the left lower suspension arm, as is the connection of the two parts by means of the connecting rod.

[0022] Other features and advantages of the invention will emerge from reading the description given below of particular embodiments of the invention, given for informational but non-limiting purposes, with reference to the appended drawings in which:

[0023] [Fig.l] is a partial schematic top view of a motor vehicle equipped with the subject of the invention;

[0024] [Fig.2] is a schematic detail view of the object of [Fig.l] according to a method of implementation;

[0025] [Fig.3] is a detailed schematic view of a first phase of assembly of the object of the invention according to another embodiment;

[0026] [Fig.4] is a detailed schematic view of a final phase of assembly of the object of the invention according to said other embodiment; and,

[0027] [Fig.5] is a schematic side view along arrow V of an element of the invention illustrated in [Fig.2].

[0028] [Fig.l] partially shows the left front top of a motor vehicle 10, and it is inscribed in an orthogonal reference frame X, Y, Z, in which the X axis extends in a front-rear longitudinal direction of the motor vehicle, oriented towards the rear; the Y axis extends in a transverse direction of the vehicle, oriented from left to right when in a rolling situation; and the Z axis extends in a vertical direction, oriented away from the ground.

[0029] [Fig.l] shows a chassis element 12 and a bodywork element 14 of the motor vehicle. Also, the chassis element 12 receives a left front lower suspension arm 16, making it possible to connect a left front wheel 18 and the chassis element 12.

[0030] The left front lower suspension arm 16 comprises a first longitudinal part 20 secured to the chassis 12, and a second longitudinal part 22 secured to the first. Also, the two longitudinal parts 20, 22 are connected together by a connecting rod 24.

[0031] A right front lower suspension arm, not shown in [Fig.l], is symmetrical to the left lower suspension arm with respect to a median plane of the motor vehicle, and it also connects a right front wheel and another chassis element, not shown.

[0032] An object of the invention is then to manufacture the front left and front right suspension arms with the same elements. Also, we will first detail with regard to [Fig.2] and [Fig.5] the embodiment of the lower left arm.

[0033] Thus, we find in [Fig.2] the front left lower suspension arm 16, and its second longitudinal part 22 secured to the first longitudinal part 20.

[0034] The first longitudinal part 20 extends along a first axis A and it has a first first end 26, or front end, and a second first end 28 opposite, or rear end. In addition, it has a first first face 30 opposite a second first face 32. Also, it has a first first edge 34 opposite a second first edge 36.

[0035] Also, the second longitudinal part 22 extends along a second axis B and it has a first second end 38 opposite a second second end 40 relative to a center C. In addition, it has a first second face 42 opposite a second second face 44. In addition, it has a first second edge 43 opposite a second second edge 45. And the two second edges 43, 45 are inclined relative to each other; it thus approaches each other from the first second end 38 towards the second second end 40.

[0036] Reference will be made to [Fig.5] showing the first longitudinal part 20 seen from the first first edge 34 according to arrow V.

[0037] We thus find the two first opposite faces 30, 32 which define a thickness e of the first longitudinal part 20. We also find the first first end 26 opposite the second first end 28.

[0038] Furthermore, a transverse light 46 is made in the thickness of the first part 20 at the level of the first first end 26. The transverse light 46 thus opens into the two opposite edges 34, 36. It has an upper wall 48 opposite a lower wall 50. And these two walls converge substantially towards each other from the first first edge 34 towards the second first edge 36. Its height is, for example, between 23 mm and 28 mm when it opens into the first first edge 34, while it is only between 20 mm and 25 mm when it opens into the second first edge 36. Furthermore, its width is, for example, between 5 mm and 10 mm.

[0039] In [Fig.2], we find the transverse light 46 delimited by two broken lines.

[0040] The second longitudinal part 22 has thus been engaged through the transverse light 46 from the first first edge 34 by first carrying the second second end 40 through the light 46, then by driving the second longitudinal part 22 in translation until the first second end 38 comes in line with the first first end 26 of the first longitudinal part 20. Also, the first second end 38 comes into wedging through the transverse light 46 taking into account its pointed shape.

[0041] The second longitudinal part 22 and the first longitudinal part 20 can thus be secured to each other by operating a weld bead at the joint between the two longitudinal parts around the transverse light 46 on the side of the second first edge 36 of the first longitudinal part 20.

[0042] It will be observed that under these conditions, the first first face 30 of the first part 20 and the first second face 42 of the second part 22 are oriented on the same side, i.e. towards the front of [Fig.2]. Conversely, of course, the second first face 32 and the second second face 44 are oriented on the same side, towards the back of [Fig.2].

[0043] To improve the rigidity of the assembly, the longitudinal connecting rod 24 is welded at its two ends, respectively to the second longitudinal part 22 and to the first longitudinal part 20.

[0044] Thus, as illustrated in [Fig.l] the first first end 26 of the first longitudinal part 20 is pivotally mounted at the front of the chassis element 12, in the longitudinal direction of the vehicle, while the second first end 28 is pivotally mounted towards the rear of the chassis 12. The second longitudinal part 22 then extends transversely to join the spindle, not shown, of the wheel 18.

[0045] As will be explained below, by means of the same longitudinal parts 20, 22 and also of the longitudinal connecting rod 24, a right front lower suspension arm is produced.

[0046] Thus, we find in [Fig.3], the first longitudinal part 20 which, with respect to its representation in [Fig.2] has been rotated by 180° along its first axis A. Therefore, the first first edge 34 is swapped with the second first edge 36. Also, we find the transverse light 46. It will be observed that the first longitudinal part 20 has a plane of symmetry cutting it parallel and equidistant from its two first faces at 30, 32.

[0047] We also find the second longitudinal part 22, which, in relation to its position as illustrated in [Fig. 2], has been pivoted around its center C, according to the plane of [Fig. 2]. Therefore, the second second end 40 of the second longitudinal part 22 can then be engaged through the transverse light 46 as illustrated in [Fig. 4].

[0048] It will then be observed that the first second end 38 is in line with the first first end 26 of the first longitudinal part 20.

[0049] Also, the second longitudinal part 22 and the first longitudinal part 20 are thus secured by operating a weld bead at the joint between the two longitudinal parts around the transverse light 46 on the side of the second first edge 36 of the first longitudinal part 20.

[0050] On the other hand, under these conditions, it can be observed that, contrary to the representation illustrated in [Fig.2], the first first face 30 of the first part 20 is oriented on the same side as the second second face 44 of the second part 22, i.e. towards the rear of [Fig.4]. And conversely, the first second face 42 of the second part 22 is oriented on the same side as the second first face 32 of the first part 20, i.e. towards the front of [Fig.4].

[0051] Also, the longitudinal connecting rod 24 is welded at its two ends, respectively on the second longitudinal part 22 and on the first longitudinal part. 20.

[0052] In this way, a right lower suspension arm 16' is obtained, adapted to be mounted on a right chassis element allowing the right front wheel, not shown, to be connected to it.

[0053] Thus, with the same elements, a first longitudinal part 20 and a second longitudinal part 22, as well as a connecting part 24, a right lower suspension arm or a left lower suspension arm is produced.

Claims

Claims

1. Method for manufacturing front lower suspension arms (16, 16') of a motor vehicle, characterized in that it comprises the following steps: - a first longitudinal part (20) is provided having, on the one hand, two first opposite ends (26, 28) and two first opposite faces (30, 32) defining a thickness, and on the other hand, two opposite edges (34, 36) and a transverse light (46) made in the thickness of one of said two first ends (26) and opening into said two opposite edges; - a second longitudinal part (22) is provided having two second opposite ends (38, 40) and two second opposite faces (42, 44);- one of said two second ends (38) is engaged through said transverse light (46), so that one of said two first faces (30) is oriented on the same side as one of said two second faces (42) to form a lower left suspension arm (16), or so that said one of said two first faces (30) is oriented on the opposite side to said one of said two second faces (42) to form a lower right suspension arm (16'); and, - said one of said two second ends (38) and said one of said two first ends (26) are secured, while said second and first longitudinal parts (20, 22) are connected together by means of a connecting rod (24) forming a triangle.;

2. Method according to claim 1, characterized in that said one of said two second ends (38) and said one of said two first ends (26) are secured by welding.

3. Method according to claim 1 or 2, characterized in that said second and first longitudinal parts (20, 22) are connected together by welding by means of a connecting rod (24) in the form of a triangle.

4. Method according to any one of claims 1 to 3, characterized in that a metal plate is stamped to provide said first and second longitudinal parts (20, 22).

5. Method according to any one of claims 1 to 4, characterized in that a first longitudinal part (20) is provided having a first plane of symmetry intersecting said first longitudinal part. between said two first opposite faces (30, 32).

6. Method according to any one of claims 1 to 5, characterized in that a second longitudinal part (22) is provided having a second plane of symmetry intersecting said second longitudinal part perpendicular to said two second opposite faces (42, 44).

7. Front lower suspension arm of a motor vehicle obtained in accordance with the method according to any one of claims 1 to 6, characterized in that it comprises: - a first longitudinal part (20) having, on the one hand, two first opposite ends (26, 28) and two first opposite faces (30, 32) defining a thickness, and on the other hand, two opposite edges (34, 36) and a transverse light (46) made in the thickness of one of said two first ends (26) and opening into said two opposite edges (34, 36);- a second longitudinal part (22) having two opposite second ends (38, 40) and two opposite second faces (42, 44), one of said two second ends (38) being engaged through said transverse light (46) to secure them, so that one of said two first faces (30) is oriented on the same side as one of said two second faces (42) to form a left lower suspension arm (16); and, - a connecting rod (24) for connecting said second and first longitudinal parts (20, 22) together to form a triangle.;

8. Front lower suspension arm of a motor vehicle obtained in accordance with the method according to any one of claims 1 to 6, characterized in that it comprises: - a first longitudinal part (20) having, on the one hand, two first opposite ends (26, 28) and two first opposite faces (30, 32) defining a thickness, and on the other hand, two opposite edges (34, 36) and a transverse light (46) made in the thickness of one of said two first ends (26) and opening into said two opposite edges; - a second longitudinal part (22) having two second opposite ends (38, 40) and two second opposite faces (42, 44), one of said two second ends (38) being engaged through said transverse light (46) to secure them, so that said one of said two first faces (30) is oriented on the side opposite to said one of said two second faces (42) to form an arm of lower right suspension (16'); and, - a connecting rod (24) for connecting said second and first longitudinal pieces (20, 22) together to form a triangle.

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