Patent Application
20130216298
The invention concerns a method for producing a chassis component, the method having the following process steps:
Furthermore, the invention concerns a chassis component with a structural component in which a joint holder is formed, and a joint cartridge in the form of a ball joint is inserted into the joint holder, and is connected solidly to the structural component by welding to form a ball and socket joint.
A chassis component as a rule comprises a structural component and one or more joints solidly connected thereto. For example such a chassis component can be a two-point control arm, a three-point control arm or a flange joint, such that the joint is integrated in the structural component as a rule by pressing, screwing or riveting. The joint can also be integrated in a one-piece structural component housing. Such a chassis component is affected in particular by the following disadvantages: it occupies more space, it is cost-intensive, the characteristics of the joint fluctuate markedly, it weighs a lot, it has a large number of individual components, it has areas prone to corrosion (for example the roll edge of the joint), substantial inventory of semifinished products must be maintained, and the logistics are complex.
From DE 603 04 709 T2 a wheel suspension arm for a motor vehicle is known, which has a body formed from a stamped sheet connected by a ball joint to a wheel carrier and by means of two mountings to the vehicle body. The ball joint has a lower mounting which is inserted into a housing formed by the body and is in contact by way of a lateral extension with the lateral edge of the housing, and a cover positioned over the lower mounting and connected solidly to the surface of the body by laser welding.
In this wheel suspension, arm tolerances can add up in an unfavorable manner, while the lower mounting and the cover are being assembled onto the body. In addition the body, the lower mounting and if necessary the cover as well have to be cleaned after assembly before a protective coating can be applied on those components. It also involves considerable complexity if the body, the lower mounting and if necessary the cover are provided with different coatings. Moreover, the weld zone is particularly prone to corrosion.
Starting from that prior art the purpose of the present invention is to protect a chassis component of the type mentioned to begin with, more effectively against corrosion.
In the method according to the invention for producing a chassis component:
From the standpoint of vulnerability to corrosion the weld zone is more sensitive than the surfaces of the joint partners consisting of the joint cartridge and the structural component, so the sealing bellows for the chassis component provided protection against corrosion. The sealing bellows covers the weld zone, which is the—or one of the—most corrosion-prone parts of the chassis component so that even if the mating parts are not provided with a corrosion protection coating the sealing bellows provides some corrosion protection for the chassis component. The invention offers the particular advantage that to protect the weld zone against environmental influences the weld zone does not have to be protected by a coating, so that the application of such a coating can be omitted.
The structural component is permanently and solidly connected to the joint cartridge, in particular by one or at least one weld seam formed by the welding process. Advantageously, the weld zone includes the, or the at least one weld seam.
According to a further development of the invention, the structural component is connected permanently and solidly to the joint cartridge by beam welding, in particular by laser beam welding. In this way a particularly low-tolerance connection of the structural component to the joint cartridge can be produced.
In particular the joint cartridge is assembled to form the joint by inserting an interior component of the joint into the joint cartridge and fitting it movably therein. Preferably, the interior component of the joint extends out of the joint cartridge through an opening of the joint cartridge.
Preferably, the joint cartridge is pre-assembled to form the joint. For this, in particular the interior joint component is inserted into the joint cartridge and fitted movably therein before the joint cartridge is inserted into the joint holder and/or connected to the structural component. Thus, independently of the structural component the joint can be produced with great precision. Preferably, the interior joint component extends out of the joint cartridge.
Preferably the joint cartridge is coated, in particular pre-coated. For this, the joint cartridge is provided with a coating in particular before it is inserted into the joint holder and/or before the structural component is connected to the joint cartridge. Preferably the structural component too is coated, in particular pre-coated. For this the structural component is provided with a coating, in particular before the joint cartridge is inserted into the holder and/or before the structural component is connected to the joint cartridge. Advantageously, the coatings of the joint cartridge and the structural component are different. In particular, the joint cartridge and the structural component are coated independently of one another.
Preferably, the joint cartridge and the structural component are coated by different coating methods. The coatings serve in particular to protect the joint cartridge and the structural component against environmental influences such as dirt and moisture. In this way the corrosion protection for the chassis component can be improved still more. Preferably the coatings are protective coatings. Preferably, the joint cartridge is coated before it is preassembled to form the joint.
The structural component is preferably coated by immersion lacquering, in particular by cathodic immersion lacquering. For example, the structural component is coated with a lacquer which, for example, contains an organic material. The joint cartridge is preferably coated by electroplating. For example, the joint cartridge is provided with a zinc-iron coating.
Preferably, the structural component pre-coated on its outside is permanently and solidly connected by welding to the joint cartridge, which is also pre-coated on its outside and preassembled to form a joint. Since the joint cartridge is already preassembled to form a joint and is connected to the structural component, there is no need for individual components of the joint to be fitted onto the structural component. In this way, by integrating the joint in the structural component a tolerance reduction can be achieved compared with DE 603 04 709 T2. Moreover, since the joint cartridge is connected to the structural component by welding, the joint cartridge can be connected to the structural component in a low-tolerance manner. Thereby, greater precision can be achieved than, for example, by pressing, screwing or riveting the joint into or onto the structural component. Finally, the joint cartridge and the structural component are already pre-coated so that, in a simple manner, different coatings can be applied to the joint cartridge and the structural component since they can be coated independently of one another. The handling of the components to be connected to one another is also simplified since the person assembling the joint cartridge and the structural component together can touch and hold them without risk, i.e. without having subsequently to clean these components, which would otherwise have been necessary prior to any coating process because of the contamination arising out of such contact.
The pre-coated structural component and the pre-coated joint cartridge are preferably pretreated before welding. In particular the pre-coated structural component and the pre-coated joint cartridge preassembled to form the joint are pretreated to prepare them for welding. Preferably, the pre-coating of the joint cartridge, in particular that of the joint cartridge after preassembly to form the joint, is partially removed before welding so as to provide an uncoated area on the joint cartridge. Preferably, the joint cartridge is connected to the structural component by welding on its uncoated area. The partial removal of the pre-coating of the joint cartridge is preferably done by laser stripping or by some other stripping process.
In particular, the pre-coating of the structural component is partially removed before welding to provide an uncoated area on the structural component. Preferably, the structural component is connected to the joint cartridge by welding on the uncoated area. It has been shown that partial stripping of the pre-coated joint cartridge and of the pre-coated structural component can be done more cheaply than welding an uncoated joint cartridge to an uncoated structural component. This is because after connecting the uncoated components, as a rule they then have to be cleaned and coated.
According to a further development of the invention the joint holder is formed on the pre-coated structural component, into which joint holder the pre-coated joint cartridge preassembled to form the joint is inserted. In particular, the joint holder is formed on the pre-coated structural component and the pre-coated joint cartridge preassembled to form the joint is inserted into the joint holder before welding. The pre-coating of the structural component is preferably partially removed during the formation of the joint holder.
The joint holder is preferably formed by beam cutting, in particular by laser beam cutting. Since this can be carried out in a manner very little affected by tolerances, the joint holder can be formed and positioned on the structural component with high precision.
Preferably, the joint cartridge is inserted into the joint holder in an axial direction. The joint holder is preferably designed with a circular, or non-circular, square, rectangular or polygonal circumferential contour. The contour is in particular an inner circumferential contour that surrounds the joint cartridge after its insertion into the joint holder. The circumferential contour of the joint holder is preferably matched to fit the outer circumferential contour of the joint cartridge, so the joint cartridge as well is designed with a circular, or non-circular, square, rectangular or polygonal circumferential contour. By forming a non-circular, many-cornered or polygonal circumferential contour, in addition to the material continuity of the weld joint rotation is prevented by positive shape interlock. Moreover, by means of a many-cornered or polygonal circumferential contour a specific rotational position of the joint cartridge relative to the axial direction can be determined. On the other hand, a circular circumferential contour has the advantage that the person assembling the joint can insert the joint cartridge into the joint holder in any angular position relative to the axial direction. Preferably, the connection between the joint cartridge and the structural component formed by welding is strong enough to provide sufficient security against rotation.
The joint holder preferably has a recess into which the joint cartridge is inserted. In a further development of the invention the joint holder comprises or consists of a hole extending through the structural component, into which the joint cartridge is inserted. In particular, the joint holder recess consists of the hole. Preferably, the hole extends in the axial direction through the structural component. The through-going hole can be formed in a simple manner by the beam cutting process mentioned earlier, and thus with high precision.
The joint cartridge preferably has a radial shoulder with which, when the joint cartridge is inserted into the joint holder, it comes into contact in the axial direction against the structural component. In particular, the shoulder rests against an edge of the joint holder. Preferably, the radial width of the shoulder is larger than that of the joint holder or its hole. The contact of the shoulder against the structural component is a positioning aid when the joint cartridge is inserted into the joint holder in the axial direction. The shoulder is in particular an external shoulder. Preferably, the shoulder extends all the way around. Preferably, on its outer circumferential surface the joint cartridge has a surrounding collar on which the shoulder is formed. The term “radial” denotes in particular any direction that extends perpendicularly to the axial direction.
According to a further development of the invention, the outer circumferential surface of the joint cartridge tapers down in the axial direction, at least in part. For example, at least in some areas the outer circumferential surface is conical in the axial direction. The tapered or conical shape of the outer circumferential surface of the joint cartridge is preferably used for centering the joint cartridge during its insertion into the joint holder. Thus for example, possible tolerance variations in the diameter of the joint holder can be compensated for.
Preferably, the structural component is connected solidly to one or more other joints. In one design version of the invention, the structural component is connected solidly to the one or more other joints before the joint holder is formed on the structural component. In particular, the location at which the joint holder is formed on the structural component is determined as a function of the position(s) of the joint(s) solidly connected to the structural component. The, or each of the position(s) is preferably characterized or determined by a kinematic point of the respective other joint. Thus, the location at which the joint holder is formed on the structural component is preferably determined as a function of the kinematic point(s) of the other joint(s) connected solidly to the structural component. In this way it is possible to achieve a clear improvement of precision compared with conventional chassis components in which the joint holder is formed already before the structural component is connected to one or more other joints, since the fitting of each of the other joints is prone to positional inaccuracies. Thus, from the kinematic standpoint a clear improvement compared with the prior art is possible. The one or more other joints preferably comprise or consist of rubber or elastomeric mountings.
In particular the joint is or forms a ball joint. Preferably, the inner component of the joint consists of a ball stud with a joint ball, which with its joint ball is inserted into the joint cartridge and fitted therein so that it can move, preferably before the joint cartridge is connected to the structural component. In particular the ball stud with its joint ball is fitted so that it can rotate and/or swivel in the joint cartridge. Preferably, the ball stud extends out of the joint cartridge through the joint cartridge's opening. In a further development of the invention, the ball stud is fitted so that it can move by sliding in a bearing shell, which is held by the joint cartridge and which is preferably made of plastic.
The wall of the joint cartridge in the area of its opening is preferably curved, in particular bent inward in the direction toward the ball stud. In that case the curved area of the wall is preferably free from the pre-coating of the joint cartridge since otherwise the coating in this area could flake off. Alternatively, in the area of the joint cartridge's opening but also in the direction toward the ball stud the wall of the joint cartridge can be shaped in advance. As another alternative the joint cartridge's opening can also be covered or at least partially covered by a covering collar fixed to the joint cartridge, through which the ball stud extends outward. However, closer tolerances can be achieved by deforming the wall of the joint cartridge in the area of its opening than when a covering collar is used, since no additional component is then needed. The covering collar or pre-shaped or deformed wall area preferably covers the joint ball in the axial direction so that the ball stud is secured in the axial direction within the joint cartridge and in particular cannot be pulled out of the latter. The wall of the joint cartridge is deformed or the covering collar is fixed to the joint cartridge preferably before the joint cartridge is connected to the structural component.
According to feature of the invention the ball stud is inserted into the joint cartridge through the joint cartridge's opening, in particular before the wall of the joint cartridge is deformed toward the ball stud in the area of the opening or before the covering collar is fixed onto the joint cartridge.
According to another feature of the invention the joint cartridge has an assembly opening opposite the joint cartridge's opening, through which the ball stud is inserted into the joint cartridge. This is in particular the case when the wall of the joint cartridge in the area of its opening has been pre-shaped in the direction toward the ball stud. When the ball stud has been inserted into the joint cartridge the assembly opening is closed by a housing cover, in particular before the structural component is connected to the joint cartridge.
The sealing bellows is preferably a joint sealing bellows which in particular seals off the opening of the joint cartridge. Preferably, the inner component of the joint extends outward through the sealing bellows, which advantageously is in contact with the inner component, forming a seal.
The sealing bellows is preferably fixed to and forms a seal against the joint cartridge and/or the structural component. Preferably, the sealing bellows is folded over the joint cartridge and/or over the covering collar and is fixed to it or to them so as to form a seal. Advantageously, the sealing bellows is stretched over the joint cartridge and/or the covering collar. In a development of the invention the sealing bellows is clamped by one or more clamping rings against the joint cartridge and/or the covering collar. In addition or alternatively, the sealing bellows can also be adhesively bonded or vulcanized onto the joint cartridge and/or the covering collar and/or the structural component.
The sealing bellows is made in particular from a flexible material. Preferably, the sealing bellows consists of an elastomer material, especially rubber.
The structural component is preferably made of metal. Moreover, the joint cartridge is also preferably made of metal. If there is a covering collar, then this as well is preferably metallic.
The invention also concerns a chassis component, in particular for a motor vehicle, having:
The chassis component according to the invention is in particular made by the method according to the invention and can be developed further in accordance with all the features described in that context.
In particular, an inner joint component is held by the joint cartridge in which it is fitted and able to move. Preferably, the inner joint component extends out of the joint cartridge through an opening in the latter. The sealing bellows seals the joint cartridge's opening. Preferably, the inner joint component extends out through the sealing bellows, which is advantageously fixed against the inner joint component to form a seal.
According to a further development of the invention the opening of the joint cartridge is covered or at least partially covered by a covering collar, which is fixed to the joint cartridge and through which the ball stud extends.
The sealing bellows is preferably fixed to form a seal against the joint cartridge and/or the covering collar and/or the structural component. Preferably, the sealing bellows is folded over the joint cartridge and/or the covering collar and is in contact with it or with them, forming a seal. Advantageously, the sealing bellows is stretched over the joint cartridge and/or the covering collar. In a further development of the invention the sealing bellows is clamped by one or more clamping rings against the joint cartridge and/or against the covering collar. In addition or alternatively, the sealing bellows can also be bonded or vulcanized onto the joint cartridge and/or the covering collar and/or the structural component.
In particular, the joint is or forms a ball joint. Preferably, the inner joint component is a ball stud with a joint ball, which with the joint ball is inserted into the joint cartridge and fitted movably in it. In particular the ball stud with its joint ball is fitted into the joint cartridge so that it can rotate and/or swivel. Preferably, the ball stud extends outward through the opening of the joint cartridge. In a further development of the invention the ball stud is fitted in such manner that the ball can move by sliding in a bearing shell, which is held in the joint cartridge and is preferably made of plastic.
Below, the invention is described with reference to preferred embodiments illustrated in the drawings, which show:
The ball stud comprises a joint ball which forms one axial end of the ball stud 6 and is fitted to move by sliding in a bearing shell, preferably made of plastic. Together with the joint ball 11, the bearing shell 12 is seated in an inside space 13 of the joint cartridge 5, within which the shell is secured against rotation. Moreover, the wall 14 of the joint cartridge 5 that delimits the inside space 13 is curved in the area of the joint cartridge's opening 7 in the direction toward the ball stud 6. Thus, in the area of the joint cartridge's opening 7 the wall 14 covers the bearing shell 12 and the joint ball 11 in the axial direction 10, so that the ball stud 6 and the bearing shell 12 are secured in the joint cartridge 5 in the axial direction 10. On its side opposite the joint cartridge's opening 7, the bearing shell 12 is in contact with the wall 14.
The joint cartridge 5 sits in a joint holder 15, which is in the form of a hole extending through the structural component 3 in the axial direction 10. The joint cartridge 5 has an all-round, radial collar 16, which defines a radially outer shoulder 17 (see
The sealing bellows 8 surrounding the joint cartridge 5 is in contact with an axial end area against both the joint cartridge 5 and the structural component 3, forming a seal, and thereby covers the weld seam 18. In addition the sealing bellows 8 surrounding the ball stud 6 rests with another axial end area against the ball stud 6 itself, again forming a seal. Thus, the connection area of the ball joint 2 and the structural component 3 is protected against environmental influences. With its circumferential contour (hole wall) 19 that delimits the joint holder 15 (see
Below, the method according to the invention for producing the chassis component 1 is described. First, the structural component 3 and the ball joint 2 are made independently of one another, the ball joint 2 being illustrated on its own in
Once the joint cartridge 5 has been inserted fully into the joint holder 15 of the structural component 3, the weld seam 18 is formed by laser beam welding and the sealing bellows 8 is then fixed onto the ball joint 2.
Before the structural component 3 is welded to the joint cartridge 5, the structural component 3 and the joint cartridge 5 are each provided on their outside with a coating, 22 and 23 respectively, but the coating 23 is removed again in an area 24 by laser stripping before the joint cartridge 5 is welded to the structural component 3. The coating 23 is applied on the outside of the joint cartridge 5 even before the ball stud 6 is inserted into the joint cartridge 5, although an axial end area 25 of the joint cartridge 5 around the joint cartridge's opening 7 is left free from the coating 23. Since the end area 25 is deformed after the insertion of the bearing shell 12 and the joint ball 11, a coating in the area 25 could flake off during the deformation. Furthermore, the coating 22 is applied on the structural component 3 before the joint holder 15 is formed. After applying the coating 22 on the structural component 3 the joint holder 15 is formed in the structural component 3 by laser beam cutting, whereby at the same time the coating 22 is removed in an edge area 26 of the structural component 3 surrounding the joint holder 15. As described earlier, the two components 2 and 3 prepared in that manner can now be inserted one into the other, after which the uncoated areas 24 and 26 are connected solidly to one another by laser beam welding, during which the weld seam 18 is formed. Once the sealing bellows has been put in place, the weld seam 18, the still exposed parts of the areas 24 and 26 and the end area 25 are protected by the sealing bellows 8 against environmental influences.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2010 043 039.0 | Oct 2010 | DE | national |
This application is a National Stage completion of PCT/EP2011/066704 filed Sep. 27, 2011, which claims priority from German patent application serial no. 10 2010 043 039.0 filed Oct. 28, 2010.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2011/066704 | 9/27/2011 | WO | 00 | 4/23/2013 |
