Control arms and methods for manufacturing a control arm

Abstract

A control arm (1) for arrangement on an axle of a motor vehicle, wherein the control arm (1) is manufactured from a sheet metal blank as a single-shell formed component and the control arm (1) has three bearing receptacles (4) and a base body area (2) arranged between them, wherein a bearing receptacle (4) has two receiving openings (6, 7) arranged parallel to each other at a distance from one another for receiving a bearing, wherein the base body area (2) is L-shaped, wherein the base body area (2) lies in a base body plane (16) and the receiving openings (6, 7) each lie in an opening plane (14), wherein the opening planes (14) lie at an angle between 80 degrees and 100 degrees to the base body plane (16), characterized in thatthat one receiving opening (6) is manufactured in one piece and of a uniform material from the sheet metal blank by forming, and the other receiving opening (7) is welded to the control arm (1) as a web section (8), and that each receiving opening (6, 7) is round and has a through-hole (13).

Description

[0001] The present invention relates to a transverse control arm according to the features in the preamble of claim 1.

[0002] The present invention further relates to a method for manufacturing a transverse control arm according to the features in claim 8.

[0003] It is known from the prior art to manufacture motor vehicles with unibody construction. To enable the wheels to be kinematically coupled to the body, chassis components are interposed. In particular, control arms are connected between the wheel carriers and the body, or between the wheel carriers and the axle subframe.

[0004] Independent suspension systems primarily utilize wishbones. These wishbones are typically equipped with two bearing mounts on the body side and one bearing mount on the wheel carrier side. Rubber-metal bushings and / or ball joints are used in these bearing mounts, allowing the wheel to compress and rebound relative to the vehicle body.

[0005] Control arms, which are typically part of a vehicle's control arm system, are usually manufactured as sheet metal components, particularly as shell components. For this purpose, a sheet metal blank is formed. To accommodate bearings, bearing sleeves are welded to this sheet metal component. However, this requires a separately manufactured bearing sleeve and a welding operation, resulting in high manufacturing costs.

[0006] From DE 10 2010 007 944 A1, a generic control arm is known which is manufactured as a one-piece, single-material, single-shell sheet metal component. The bearing receptacle of the cross member is designed such that it has two receiving openings, the receiving openings being arranged essentially perpendicular to a base plane. A through-hole is formed in each receiving opening. The through-hole is suitable for receiving a rubber-metal bearing. While this control arm avoids welding, it requires a complex forming technique. In particular, wedge-sliding operations must be performed within the forming tool to produce the respective bearing eyes for forming the bearing receptacle openings at a 90-degree angle to the base plane.

[0007] Further wishbones are known from DE 10 2013 213 038 A1, EP 2 927 029 A1, DE 10 2014 222 577 A1 and DE 10 2013 203 906 A1.

[0008] The object of the present invention is therefore to demonstrate a single-shell control arm which has at least one bearing receptacle and can be manufactured more economically compared to control arms known from the prior art.

[0009] The aforementioned problem is solved according to the invention with a transverse control arm for arrangement on an axle of a motor vehicle with the features of claim 1. A process-related part of the problem is solved according to the invention with the features of claim 8.

[0010] Advantageous embodiments of the invention are described in the dependent claims.

[0011] The control arm is mounted on an axle of a motor vehicle and is manufactured as a single-shell formed component from a sheet metal blank. The control arm has three bearing receptacles and a base section located between them. One of these bearing receptacles is formed by two parallel receiving openings spaced apart from each other. The receiving openings are arranged essentially perpendicular to the base section. This means that each plane in which the receiving opening lies is essentially orthogonal to the plane in which the base section lies.

[0012] According to the invention, the control arm is characterized in that a receiving opening, in particular the bearing eye in which the receiving opening is located, is manufactured in one piece and from a sheet metal blank by forming. The other receiving opening is formed by a web section, the web section being welded to the control arm. The web section is also manufactured as a one-piece sheet metal component.

[0013] The advantage of the invention lies in the fact that the receiving opening can be produced simultaneously during the forming of the control arm into a single-shell, one-piece sheet metal component, particularly by bending or folding it. This can be carried out especially in a forming tool consisting of an upper and lower tool. A wedge-sliding operation, in particular a forming operation that performs additional movements beyond the actual press stroke direction, is not initially required.

[0014] The second receiving opening, or rather the bearing eye surrounding it, is formed in a separate web section. This web section is also a sheet metal blank and a separate formed component, which is welded to the control arm. For this purpose, the web section projects into the base body area, particularly along its longitudinal axis. The web section is essentially perpendicular to the base body area and is connected to it by at least one weld. This offers the advantage that two receiving openings can be arranged parallel to each other at a distance.

[0015] The mounting openings each have a through-hole. These through-holes can be created after the welding process is complete. This offers the advantage of simultaneously calibrating the through-holes for the subsequent mounting, particularly pressing in, of a bearing. However, the through-holes can also be created beforehand. In this case, a further calibration process is performed after the welding is complete, ensuring a geometrically accurate relative position of the bearing mount to the control arm.

[0016] Preferably, two bearing mounts on the control arm can also be designed according to this principle. In a further particularly preferred embodiment, all three bearing mounts on the control arm can also be designed according to this principle. This offers the further advantage that the mounting opening of each bearing mount is at a 90-degree angle to the plane of the base body.

[0017] In particular, the control arm is manufactured from a steel blank. The control arm can be manufactured using a cold forming process. However, it can also be manufactured by hot forming and press hardening. The steel blank is preferably selected with a wall thickness between 1.5 mm and 5 mm, preferably from 2 mm to 4 mm, and most preferably from 3 mm to 4 mm.

[0018] The control arm is essentially L-shaped, particularly when viewed from above. This means that the main body plane is formed by two legs extending longitudinally at an angle to each other. The bearing mounts can be located at one end of each leg as well as at the point where the legs meet.

[0019] However, the control arm can also be A-shaped when viewed from above. In particular, such a control arm is used as a triangular control arm, for example, in the upper control arm plane. Consequently, an A-shaped sheet metal blank is also produced.

[0020] In the context of the invention, "essentially perpendicular with respect to the positioning of the receiving openings to the plane of the base body" means that the plane of the opening of each receiving opening is arranged at an angle between 80 degrees and 100 degrees, preferably 85 degrees and 95 degrees, and in particular perpendicular, i.e. 90 degrees, to the plane of the base body.

[0021] The web section is designed in particular as a flange. The web section is also essentially perpendicular or orthogonal to the plane of the base body.

[0022] Preferably, a positioning flange is formed on the bearing area. The positioning flange is formed in one piece with the base body and is made of the same material. For this purpose, the positioning flange is also formed by forming it essentially perpendicular to the plane of the base body. The web section is arranged at least partially in contact with the positioning flange and then bonded to the base body area by a material connection.

[0023] Preferably, the web section has a lateral recess, the recess being abutting a side edge of the base body area. This means that the side edge of the base body area is arranged to engage at least partially in the recess. The area of ​​the web section opposite the receiving opening then engages under the base body area or projects into it and is connected to the base body area, in particular by a weld. This enables a particularly advantageous guidance of the load path when a force is applied to the control arm.

[0024] In addition to the advantages of simpler production during the forming process and the elimination of wedge-sliding operations in the forming tool and / or subsequent forming steps, the control arm according to the invention offers a further advantage. When manufacturing the sheet metal blank of a substantially L-shaped control arm, the web section can be cut out simultaneously. In a valley area of ​​the L-shaped sheet metal blank, which would otherwise have to be recycled as residue or scrap after the cutting operation, it is possible to produce the web section. This minimizes the scrap remaining after the cutting process, which in turn reduces manufacturing costs. A further essential advantage of the invention is that identical control arms can be manufactured in mirror images for the left and right sides of the vehicle.In this case, two L-shaped sheet metal blanks can be positioned within a strip of sheet metal in such a way that they form a rectangle around the outside. Within the resulting inner area, the two web sections can then be cut out simultaneously, thus minimizing the amount of scrap generated during the cutting process.

[0025] The inventive method provides for the following process steps: - Providing a strip material made of a steel material, - simultaneous cutting out of an L-shaped sheet metal blank and a web section, - Forming of the sheet metal blank into a semi-finished control arm product, - Welding the web section to a bearing mount of the control arm semi-finished product.

[0026] A further advantage of the method according to the invention is that at least the cutting and forming can be carried out in a progressive die. After the cutting process, the web sections would first be extracted from the progressive die and then positioned accordingly on the control arm in a subsequent welding process. Alternatively, the work steps can also be carried out in a transfer die.

[0027] The creation of the through-holes can be performed before or after the welding process. Creating the through-holes before welding is particularly advantageous when working in opposite directions. Optionally, a calibration step can be performed after welding in this case.

[0028] For through-holes pointing in the same direction and / or towards each other, these are preferably produced after the welding process. A calibration process can then be carried out simultaneously during the production of the through-holes.

[0029] The control arm can preferably be provided with a corrosion protection measure after welding, for example by a cathodic dip coating (KTL) process. Alternatively, a sheet metal component with a pre-coating can be used. A multi-layered sheet metal material can also be used, especially with outer layers that offer corrosion protection.

[0030] Further advantages, features, properties, and aspects of the present invention are the subject of the following description. Preferred embodiments are illustrated in the schematic figures. These serve to facilitate understanding of the invention. They show: Fig. 1 and Fig. 2 different control arms, known from the state of the art, Fig. 3 and Fig. 4 a control arm according to the invention, Fig. 5 a cross-sectional view through a storage area, Fig. 6 a section of the bridge and Fig. 7 a manufacturing process.

[0031] In the figures, the same reference symbols are used for identical or similar components, even if a repeated description is omitted for the sake of simplicity.

[0032] Fig. Figure 1 shows a control arm 1 as known from the prior art. A base body section 2 is formed for this purpose. The base body section 2 has two legs 3, which are arranged in an essentially L-shape relative to each other. A bearing receptacle 4 is formed at each end of a leg 3, as well as in a corner section E where the two legs 3 meet. The bearing receptacle 3 of the corner section is formed by two bearing eyes, each of which lies essentially in an opening plane. The opening plane is arranged perpendicular to a base body plane. This bearing receptacle 4 is manufactured by forming. However, the forming operations performed to manufacture the control arm require increased effort.

[0033] Fig. Figure 2 also shows a control arm 1 known from the prior art. This also has bearing mounts 4 at the ends of the legs 3. In a corner region E, where the two legs 3 meet, a bearing mount 4 is formed by welding a bearing connection sleeve 5 to the base body region 2. However, the production of the bearing connection sleeve 5 and the welding process also require increased manufacturing resources.

[0034] In the Fig. 3 and Fig. Figure 4 now shows the embodiment of a control arm 1 according to the invention. For this purpose, the control arm 1, also having a base body area 2, is essentially L-shaped and consists of two legs 3. The respective legs 3 of the L-shape thus lie essentially flat in a Fig. The basic body plane 16 shown in Figure 5. The control arm 1 is thus designed as a single-shell sheet metal component. Bearing receptacles 4 are formed at the ends of the legs 3, as well as in a corner area E where the two legs 3 meet. The legs 3 may have further indentations, recesses, through-holes, or similar features, in particular to improve the stiffness and / or reduce the weight of the legs 3.

[0035] However, according to the invention, it is now provided that the bearing receptacle 4 in the corner region E of the two legs 3 is manufactured in such a way that a receiving opening 6 is produced directly by forming during the forming process of the control arm 1 and a second receiving opening 7 is formed by a welded-on web section 8.

[0036] The web section 8 itself is manufactured as a separate formed component and is materially coupled to the control arm 1, in particular to the base body area 2, which is shown again in the sectional view AA of Fig. Figure 3 shows that the web section 8 is bonded to the base body area 2 via the weld seam 24. The web section 8 itself preferably has a recess 9. An edge region 10 of the control arm 1 engages in the recess 9, and the remaining part of the web section 8 engages under the control arm 1 and is bonded to it.

[0037] First, the control arm 1 is manufactured as a single-shell sheet metal forming component with the first receiving opening 6. The receiving opening 6 itself is formed by a bearing eye 12, in particular with a through-hole 13. The receiving opening 6 lies in an opening plane 14, wherein, in particular, the two opening planes 14 of the receiving openings 6 and 7 are arranged parallel to each other at a distance a. The respective through-holes 13 project from this.

[0038] In the example of Fig. 4 The two passages 13 are oriented towards each other. The second receiving opening 7 also lies in an opening plane 14. Both opening planes 14 are arranged perpendicular to a base body plane 16, according to Fig. 5.

[0039] According to the invention, the web section 8 with the second receiving opening 7 is now manufactured as a separate sheet metal component. This is attached to the bearing receptacle 4 and welded to the control arm 1. Preferably, a positioning flange 17 is formed on the control arm 1 for this purpose. This positioning flange 17 can also be manufactured during the forming process of the single-shell control arm 1. It is also arranged substantially orthogonally to the base body plane 16. After assembly of web section 8 and positioning flange 17, these components are in contact, at least in certain areas. The positioning flange 17 can have a curvature 18. The curvature 18 then engages, at least in certain areas, the outer surface of the second through-hole 15 of the second receiving opening 7.

[0040] Fig.Figure 7 shows a section of a manufacturing process according to the invention. L-shaped sheet blanks 20 are cut from a strip material, for example, a steel sheet strip 19. In the embodiment shown here, two sheet blanks 20 are produced corresponding to each other, in particular as mirror images. The two L-shaped sheet blanks 20 are arranged in the sheet strip 19 such that they essentially form a rectangle. In an inner region 21 of this rectangle, which is formed by a respective valley region 22 of the L-shaped sheet blank 20, blanks for the web sections 8 are produced. This minimizes the amount of offcuts, and thus the amount of scrap material. The blank for producing the web section 8 is in particular teardrop-shaped or triangular. Reference symbol: 1 wishbone 2 Basic body area 3 legs to 2 4 Bearing 5 Bearing connection sleeve 6 first intake opening 7 second intake opening 8 Bridge section 9 exception to 8 10 Edge area to 2 Part 11 of 8 12 bearing eye 13. Draft to 6 14 Opening level 15 passage to 8 16 Basic plane 17 Positioning flange 18 Curvature to 17 19 steel sheet strip 20 L-shaped sheet metal cutouts 21 Indoor area 22 valley area to 20 23 cuts to 8 24 weld seam E corner area

Claims

[1] Control arm (1) for arrangement on an axle of a motor vehicle, wherein the control arm (1) is manufactured from a sheet metal blank as a single-shell formed component and the control arm (1) has three bearing receptacles (4) and a base body area (2) arranged between them, wherein a bearing receptacle (4) has two receiving openings (6, 7) arranged parallel to each other at a distance from each other for receiving a bearing, wherein the base body area (2) is L-shaped, wherein the base body area (2) lies in a base body plane (16) and the receiving openings (6, 7) each lie in an opening plane (14), wherein the opening planes (14) are at an angle between 80 degrees and 100 degrees to the base body plane (16), characterized by, that one receiving opening (6) is manufactured in one piece and of uniform material from the sheet metal blank by forming, and the other receiving opening (7) is welded to the control arm (1) as a web section (8), and that each receiving opening (6, 7) is round and has a through-hole (13). [2] Control arm (1) according to claim 1, characterized by , that the passages (13) are arranged in a direction pointing towards each other or that the passages (13) are arranged in a direction pointing away from each other. [3] Control arm (1) according to claim 1 or 2, characterized by , that the wishbone (1) is made from a sheet of steel, in particular with a wall thickness between 1.5 mm and 5 mm. [4] Control arm according to any one of claims 1 to 3, characterized by , that the web section (8) is designed as a flange, wherein the flange rests orthogonally on the base body area (2) and is coupled with at least one weld. [5] Control arm (1) according to any one of claims 1 to 4, characterized by , that a bearing area has a positioning flange (17) which is designed to be orthogonal to the base body area (2). [6] Control arm (1) according to claim 5, characterized by , that the positioning flange (17) and the web section (8) are partially in contact with each other and / or that the positioning flange (17) has a curvature (18) which at least partially encompasses an outer surface of the passage (13) of the web section (8). [7] Control arm (1) according to any one of claims 1 to 6, characterized by , that the web section (8) has a lateral recess (9), wherein the recess (9) abuts a side edge of the base body area (2) such that the part of the web section (8) opposite the receiving opening (6) engages the base body area (2). [8] Method for manufacturing a transverse control arm (1) according to at least claim 1, characterized by the following method steps: - Providing a strip material made of a steel material, - simultaneous cutting out of an L-shaped sheet metal blank (20) and a web section (8), - forming process of the sheet metal blank (20) to form a semi-finished control arm, - Welding the web section (8) to a bearing mount (4) of the control arm semi-finished product. [9] Method according to claim 8, characterized by , that the web section (8) is formed before the welding process. [10] Method according to claim 8 or 9, characterized by , that at least the cutting and forming is carried out in a progressive die tool or in a transfer tool. [11] Method according to any one of claims 8 to 10, characterized by, that in the bearing (4) through-holes are made before or after the welding process. [12] Method according to any one of claims 8 to 11, characterized by , that the bridge section (8) is cut out in a valley area (22) of the L-shaped sheet metal blank (20) or an A-shaped sheet metal blank. [13] Method according to any one of claims 8 to 12, characterized by , that two L-shaped sheet metal blanks (20) are cut out simultaneously, wherein the L-shaped sheet metal blanks (20) with their valley areas (22) enclose an inner area (21) and two web sections (8) are cut out simultaneously from the inner area (21). [14] Method according to any one of claims 8 to 13, characterized by, that during the forming of the sheet metal blank (20) the bearing receptacle (4) is machined in such a way that a receiving opening (6) is produced perpendicular to the base body plane (16) and a bearing receiving opening formed parallel to it at a distance is provided by welding on the web section (8).

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