Glued, carbon fiber reinforced control arms with ball and socket joints and methods of making the same

Abstract

The invention relates to a control arm (1) having a frame (10), at least one interface (2, 3) arranged on the frame (10), and a ball-and-socket joint (4) arranged on the frame (10). The ball-and-socket joint (4) comprises an insert (8) of an elastic plastic material, which is glued in or on a complementary socket of the frame (10). A ball portion (5a) of a ball-and-socket joint pin (5) is arranged rotatably in the insert (8). A plastic material coating (6) is arranged on the ball portion (5a), and a metal coating (7) is arranged on the plastic material coating (6) in such a way that it comes into contact with the inner surface of the insert (8). The invention also relates to a method for producing the control arm (1).

Description

TECHNICAL FIELD

[0001] The present invention relates to a control arm and to a method for manufacturing a control arm. BACKGROUND

[0002] German patent DE 102 016 200 353 A1 discloses a control arm and, implicitly, a method for manufacturing a control arm. The control arm of the prior art has a frame, two interfaces arranged on the frame and axially oriented on a common first axis, and a ball joint arranged on the frame and located on a second axis intersecting the first axis. The frame consists of a substantially triangular metal sheet. The control arm is also called a suspension arm and is a component of a motor vehicle suspension system. The control arm serves to connect the vehicle frame to the wheel carrier of the vehicle. The suspension system serves to support and suspend the vehicle frame in a movable manner at a predetermined height in order to ensure that the vehicle travels sufficiently stably in the case of different road characteristics. The control arm is here subjected to dynamic loads. It is therefore important that the control arm is sufficiently rigid and robust to withstand such loads. For this reason, the control arm in the prior art consists of a metal sheet, so that the control arm is robust on the one hand and as light as possible on the other hand.

[0003] DE 102 004 048 753 A1 discloses a ball joint for a control arm with a metal ball accommodated by a housing. Between the metal ball and the housing there is a bearing shell made of a plastic material, which is uniformly distributed with reinforcing parts and friction-reducing parts.

[0004] DE 102 011 108 881 A1 discloses a ball joint housing made of a double-layer metal sheet. KR 101 549 918 B1 discloses a rod-shaped carbon fiber reinforced suspension arm.

[0005] Further suspension systems are known from US 20120141192 A1, US 20050063769 A1 and US 5152628 A. SUMMARY

[0006] According to the prior art shown, there is still room for improvement in the control arm and in the method for manufacturing the control arm. Many different requirements, in particular in terms of durability, joint friction, weight and manufacturing costs, must be met.

[0007] It is an object of the present invention to provide a control arm and a method for manufacturing a control arm, by means of which, on the one hand, the overall weight of the control arm can be reduced and the interface to the vehicle frame can be simplified, while, on the other hand, a sufficiently rigid and robust connection between the ball joint pin and the control arm frame is maintained.

[0008] According to the application, this object is achieved by a control arm having the features described below, the control arm comprising a frame, at least one interface arranged on the frame and a ball joint arranged on the frame. The ball joint comprises an insert of an elastic plastic material, which is glued into or onto a complementary socket of the frame. A ball portion of the ball joint pin is arranged rotatably in the insert. A coating of plastic material is provided on the ball portion, and a coating of metal is provided on the coating of plastic material in such a way that the coating of metal comes into contact with the inner surface of the insert. The coating of metal on the coating of plastic material ensures low friction and sufficient tolerances in the ball joint.

[0009] It should be noted that features and measures listed individually in the following description can be combined in any desired, technically expedient manner, and further configurations of the application are disclosed. The description characterizes the application in addition and in particular gives details of the application in connection with the drawings.

[0010] By the insert being composed of an elastic plastic material instead of a metal material, the weight of the entire control arm is reduced. Furthermore, such an insert enables the manufacture of the vehicle frame interface to be simplified, while maintaining a sufficiently rigid and secure connection between the ball joint pin and the control arm frame of the vehicle.

[0011] The frame is preferably composed of a fiber composite material, i.e. of a fiber-reinforced plastic material, whereby a further reduction in weight can be achieved. The insert is preferably composed of a fiber composite material, i.e. of a fiber-reinforced plastic material, whereby a further reduction in weight can be achieved. Suitable fiber composite materials here are any materials in which fibers (for example glass fibers, carbon fibers and / or aramid fibers) are embedded in order to reinforce a polymer matrix (for example a matrix of a plastic material or synthetic resin). Other particles, layers or components which cannot be classified as polymers or fibers can optionally be incorporated or attached here.

[0012] The interface is preferably a bushing mount for accommodating a rubber bushing, which can advantageously be integrally formed during the shaping of the frame.

[0013] Preferably, two interfaces are provided, which are oriented axially on a common first axis, and the ball joint is located on a second axis which intersects the first axis. The robustness of the frame and the control arm as a whole is thus improved.

[0014] According to the application, the object is also achieved by a method for manufacturing a control arm having the features described below. The method according to the application relates to the manufacture of a control arm comprising a frame, at least one interface arranged on the frame and a ball-and-socket joint arranged on the frame. The method has the steps of coating the ball portion of the ball-and-socket joint pin with a plastic material coating, coating the plastic material coating with a metal coating, inserting the ball portion coated with the plastic material coating and the metal coating into an insert composed of an elastic plastic material such that the metal coating comes into contact with the inner surface of the insert, and gluing the insert into or onto a complementary socket of the frame in order to construct the ball-and-socket joint. The same advantages as with the control arm according to the application are thereby achieved.

[0015] Preferably, the frame is composed of a fiber-reinforced plastic material and the insert is composed of a fiber-reinforced plastic material, whereby a further weight reduction can be achieved.

[0016] The metal coating is preferably applied by a vapor deposition process, such that a very precise layer thickness with tight tolerances can be achieved. The plastic material coating is preferably formed by encapsulation injection molding of the ball portion, such that the plastic material coating can maintain precise tolerances, for example by using precision tools. BRIEF DESCRIPTION OF DRAWINGS

[0017] Further advantageous configurations of the application are disclosed in the following description of the drawings, in which:

[0018] Figure 1 A plan view of a control arm according to an exemplary embodiment of the application is shown; and

[0019] Figure 2 A sectional view along the section plane A-A of the control arm according to an exemplary embodiment of the application is shown. Figure 1 A sectional view along the section plane A-A of the control arm according to an exemplary embodiment of the application is shown. DETAILED DESCRIPTION

[0020] The same components are provided with the same reference signs in all the figures, so they are generally only described once.

[0021] Figure 1 A plan view of a control arm 1 according to an exemplary embodiment of the application is shown. Figure 2 A sectional view along the section plane A-A of the control arm according to an exemplary embodiment of the application is shown. Figure 1 A sectional view along the section plane A-A of the control arm according to an exemplary embodiment of the application is shown.

[0022] The control arm 1 has a frame 10 and two interfaces 2, 3 arranged on the frame 10 and oriented on a common first axis X. In addition, the control arm 1 comprises a ball-and-socket joint 4 arranged on the frame 10 and located on a second axis Y intersecting the first axis X.

[0023] The control arm 1 is part of a vehicle suspension and serves to connect the vehicle frame to the wheel carrier of the vehicle. Here, two interfaces 2, 3 serve to connect the control arm 1 to the vehicle frame, and a ball joint 4 serves to connect the control arm 1 to the wheel carrier.

[0024] The frame 10 is composed of a fiber-reinforced plastic material, so that the weight is lower than with a conventional frame composed of sheet metal. The frame 10 is essentially triangular in shape, with the two interfaces 2, 3 and the ball joint 4 being located at the corners of the frame 10. The frame 10 has a first arm 101 and a second arm 102. When the control arm 1 is installed in a vehicle, the first arm 101 can be oriented toward the front of the vehicle and the second arm 102 toward the rear of the vehicle. The first arm 101 is essentially straight and perpendicular to the first axis X and parallel to the second axis Y. The second arm 102 is essentially arcuate. In the region of the ball joint 4, the second arm 102 extends essentially parallel to the second axis Y and converges toward the first axis X as it extends forward.

[0025] The two interfaces 2, 3 are preferably bushing mounts for accommodating rubber bushings (not shown). Alternatively, the bushing mounts can be of one-piece construction, and they can also provide the possibility of accommodating two rubber bushings or similar bearings. The rubber bushings can be glued or inserted into or onto the bushing mounts or can be cast with the bushing mounts. The two interfaces 2, 3 are axially oriented on the first axis X, i.e., the control arm 1 mounted at the two interfaces 2, 3 can be rotated about the first axis X.

[0026] The ball joint 4 comprises an insert 8 of an elastic plastic material, which is glued into a complementary socket of the frame 10. The insert 8 is composed of a fiber-reinforced plastic material in the present case, so that it contributes to further weight reduction. The insert 8 can be composed of a plastic material with low friction, which can contain PTFE, for example.

[0027] As with the frame 10, the fiber-reinforced plastic material of the insert 8 can be a carbon fiber-reinforced plastic material.

[0028] A ball portion 5a of the ball joint pin 5 is arranged rotatably in the insert 8. In the normal position, the ball joint pin 5 extends along a third axis Z, which is perpendicular to the first axis X and the second axis Y. The ball joint pin 5 is rotatable about all three spatial axes X, Y, and Z.

[0029] A plastic material coating 6 is provided on the ball portion 5a, and a metal coating 7 is provided on the plastic material coating 6, so that the metal coating 7 is in contact with the inner surface of the insert 8. The inner surface of the insert 8 is preferably spherical, complementary to the ball portion 5a. The metal coating 7 on the plastic material coating 6 ensures a low-friction, smooth surface, good durability, and sufficiently tight tolerances in the ball joint 4.

[0030] A method for manufacturing a control arm 1 according to the present application is described below. First, the ball portion 5a of the ball-and-socket joint pin 5 is coated with a plastic material coating 6, for example by encapsulation by injection molding, and then the plastic material coating 6 is coated with a metal coating 7. The metal coating 7 is applied, for example, by a vapor deposition process, such as thermal vapor deposition or a PVD process. Once the coatings 6, 7 on the ball portion 5a have hardened, the ball portion 5a coated with the plastic material coating 6 and the metal coating 7 is inserted into the insert 8 in such a way that the metal coating 7 comes into contact with the inner surface of the insert 8. Here, the ball portion 5a is introduced into the insert 8 along the third axis Z through an opening in the insert 8 arranged in the bottom. Figure 2 The opening in the insert 8 has a smaller diameter than the ball portion 5a. The elastic plastic material of the insert 8 has a suitable elasticity so that its opening temporarily widens when the ball portion 5a is inserted. To this end, a groove (not shown) can be provided in the insert 8, which insert 8 is recessed along the third axis Z from the bottom upward. Figure 2 The fiber-reinforced plastic material is particularly suitable as a material for the insert 8, which has good deformability on the one hand and sufficient rigidity on the other hand.

[0031] Once the ball portion 5a is inserted into its final position within the insert 8, the insert 8 essentially returns to its original shape. The insert 8 prepared in this way is then glued into a complementary socket of the frame 10 to construct the ball-and-socket joint 4. To this end, the frame 10 is provided beforehand with a socket complementary to the insert. Figure 2 The reference 9 in the figure indicates an adhesive layer between the insert 8 and the complementary socket of the frame 10. The adhesive layer 9 can be applied directly to the insert 8 or into the complementary socket of the frame 10, or it can be applied by dipping the insert 8 into an adhesive. Compared to conventional control arms, the manufacturing costs can be reduced by gluing the insert 8 into the complementary socket of the frame 10.

[0032] Gluing the prefabricated assembly consisting of the insert 8 and the ball-and-socket joint pin 5 located therein into the complementary socket of the relatively rigid frame 10 results in a very robust mounting of the ball-and-socket joint pin 5 as a whole. At the same time, this robust mounting is achieved by a simple manufacturing method. The use of plastic for the frame and the insert also makes it possible to reduce the weight. In addition to the metal coating 7, the use of metal materials can be dispensed with.

[0033] Compared to conventional control arms, the manufacturing costs can be reduced by the control arm according to the present application and the method according to the present application. In addition, the design is simplified, the weight can be reduced mainly by dispensing with metal parts in addition to the metal coating 7, and a rigid and robust connection with high durability is achieved between the ball-and-socket joint pin 5 and the frame 10.

[0034] The method steps are preferably carried out in the order described above, but can include other intermediate steps or other coatings as desired.

[0035] List of reference signs:

[0036] 1 control arm

[0037] 2 interface

[0038] 3 interface

[0039] 4 ball joint

[0040] 5 ball joint pin

[0041] 5a ball

[0042] 6 plastic material coating

[0043] 7 metal coating

[0044] 8 insert

[0045] 9 adhesive layer

[0046] 10 frame

[0047] 101 first arm

[0048] 102 second arm

Claims

1. A method for producing a control arm, the control arm comprising a frame (10), at least one interface (2, 3) arranged on the frame (10) and a ball and socket joint (4) arranged on the frame (10), It is characterized by: The method comprises the following steps: coating the ball portion (5a) of the ball and socket joint pin (5) with a coating (6) of plastic material; coating the plastic material coating (6) with a metal coating (7); embedding the ball (5a) having the plastic material coating (6) and the metal coating (7) into an insert (8) made of elastic plastic material such that the metal coating (7) is in contact with the inner surface of the insert (8), the ball (5a) being introduced into the insert (8) through an opening arranged in the insert (8), the opening having a smaller diameter than the ball (5a), the elasticity of the elastic plastic material of the insert (8) causing the opening to temporarily widen when the ball (5a) is embedded; as well as The insert (8) is glued into a complementary socket in the frame (10) to construct the ball and socket joint (4).

2. The method according to claim 1, It is characterized by: The frame (10) is made of fiber-reinforced plastic material.

3. The method according to claim 1 or 2, It is characterized by: The insert (8) is made of a fiber-reinforced plastic material and is glued into a complementary socket of the frame (10) by means of an adhesive layer located between the insert (8) and the complementary socket of the frame (10).

4. The method according to any one of the preceding claims 1 to 2, It is characterized by: The metal coating (7) is applied by a vapor deposition process.

5. The method according to any one of the preceding claims 1 to 2, It is characterized by: The plastic material coating (6) is formed by encapsulating the ball portion (5a) by injection molding.

Images