Patent Application
20210086580
The invention relates to a torsion bar for a stabiliser of a motor vehicle according to the type indicated in the preamble of claim 1, as well as a method to produce a stabiliser according to claim 5 and a stabiliser for a motor vehicle according to the type indicated in the preamble of claim 11.
U-shaped stabilisers for motor vehicles having a fiber-composite torsion bar extending essentially along the vehicle's transverse direction (Y-axis) in the installed state, as well as metallic stabiliser limbs, the axial ends of which are rotationally fixed, extending essentially in the vehicle's longitudinal direction (X direction) are well-known from the prior art; cf. DE 10 2012 008 995 A1. According to the teaching of this publication, the shaft-hub connection between the torsion bar and the stabiliser limb is established in that the torsion bar is pressed onto the hub, which has inner toothing, with material displacement. In addition to the form-fitting connection, an adhesive bond is created by means of an adhesive connection. To this end, a liquid adhesive is preferably applied between the tooth flanks such that said adhesive fills in the material-free space that develops during the press-on process. The adhesive, which is applied in liquid form to the parts to be connected, thus particularly serves as a lubricant during the press-on process as well as corrosion protection after the adhesive is cured. This has been proven to be disadvantageous such that the liquid adhesive generates extensive adhesive erosion, which must be elaborately cleared away after a certain quantity and thus necessitates an interruption in production or lands on the floor of the production facility as debris, which is problematic for DIN-certified production.
The object of the invention is to further develop a torsion bar for a stabiliser of a motor vehicle according to the type indicated in the preamble of claim 1 such that a simplified production of a stabiliser for a motor vehicle is enabled, which causes less debris erosion and is optionally DIN-certified.
This object is achieved by the characterizing features of claim 1 in conjunction with its preamble features.
Dependent claims 2 to 4 represent advantageous refinements of the torsion bar according to the invention.
It is provided, in a known form and manner, that a stabiliser limb can be rotationally fixed at the axial ends of the torsion bar. In the mounted state, the torsion bar is essentially aligned in the vehicle's transverse direction (Y direction) in this case, and the stabiliser limbs extend essentially in the vehicle's longitudinal direction (X direction).
Preferably, the torsion bar is hollow-cylindrical and formed from a fiber-composite material, while the stabiliser limbs are produced from a light metal alloy, particularly an aluminum alloy.
According to the invention, it is provided that the torsion bar is coated with an adhesive coating in the area of the axial ends thereof and a protective layer covering the adhesive coating, wherein the adhesive coating is formed as a solid adhesive coating, which can be activated after at least partial removal of the protective layer.
The design according to the invention has proven to be particularly advantageous, because no liquid adhesive erosion occurs during production of the stabiliser due to the solid physical state of the adhesive coating, with the result that a quicker, interruption-free, and particularly also DIN-certified production of the stabiliser is enabled.
Preferably, the adhesive coating comprises polyurethanes, silicones, MS polymers, epoxide resins, rubber, and/or acrylate as the adhesive component.
According to an especially preferred embodiment, the adhesive coating is in the form of a multi-component adhesive, wherein at least one of the adhesive components is present in microencapsulated form.
Preferably in this case, the adhesive component can be activated by means of a mechanical bursting of the microcapsule, the input of heat, solvents, and/or moisture.
Preferably, the protective layer is formed from a form-stable material, particularly from a polyolefin thermoplastic.
The object upon which the invention is further based is to provide a method for producing a stabiliser for a motor vehicle, which enables a simplified production of a stabiliser for a motor vehicle, which causes less debris erosion and is optionally DIN-certified.
This object is achieved by the method according to claim 5.
Dependent claims 6 to 10 represent advantageous refinements of the method.
The method according to the invention comprises the following steps:
The essential advantage of the method is that the problems known from the prior art no longer occur due to the dry joining/adhesive method such that a production method is provided that is free of debris and thus also optionally DIN-certifiable.
In order to prevent, to the extent possible, material erosion of the protective layer into the adhesive coating underneath during joining of the components, the material erosion occurring during insertion of the axial ends of the torsion bar into the hub bore of the stabiliser limbs is suctioned off.
Preferably, a form-fitting connection is additionally established in the area of the joint between the torsion bar and the stabiliser limbs during joining of the torsion bar with the stabiliser limbs. Because a form-fitting connection then exists between the torsion bar and the stabiliser limbs in addition to the adhesive bond connection, an especially operationally-safe connection is ensured between the components.
Preferably, it is provided for this that the hub bore of the stabiliser limbs has inner toothing such that an external-tooth-like contour is cut into the protective layer during the joining process.
According to an especially preferred embodiment, it is provided that the protective layer is provided already having an external-tooth-like contour corresponding to the inner toothing. The inner toothing present in the hub bore and the external-tooth-like contour of the protective layer in this case are matched to one another in the dimensioning thereof such that the tooth tips of the inner toothing cut into the protective layer in the area between two teeth of the external-tooth-like contour and thus expose the adhesive coating in this area during joining, i.e. during axial insertion of the ends of the torsion bar into the respectively assigned hub bore.
In addition, it is conceivable that a force-fitting connection is also established between the torsion bar and stabiliser limb components during joining, in addition to the previously mentioned adhesive and form-fitting connection.
The activation of the adhesive component of the adhesive coating preferably takes place by means of mechanical bursting of the microcapsule, particularly caused by axial insertion of the axial ends of the torsion bar into the hub bore of the stabiliser limbs, and/or due to heat input and/or the supplying of a solvent and/or supplying of moisture.
To ensure complete curing of the adhesive connection between the torsion bar and the stabiliser limb, swapping out of the joined stabiliser may be provided as a further method step.
A further object upon which the invention is based is to refine a stabiliser for a motor vehicle according to the type indicated in the preamble of claim 11 such that a simple production is ensured with a low component weight of the stabiliser and an operationally-safer connection between the torsion bar and the stabiliser limbs.
This object is achieved by the characterizing features of claim 11 in conjunction with its preamble features.
Dependent claims 12 and 13 represent advantageous refinements of the stabiliser.
In a known form and manner, the stabiliser has a substantially U-shaped structure and comprises a torsion bar, which is aligned substantially in the vehicle's transverse direction in the installed state and which is made of a fiber-composite material, as well as two stabiliser limbs, which are aligned in the vehicle's longitudinal direction in the installed state and arranged rotationally fixed at the axial ends thereof.
According to the invention, the torsion bar is formed according to one of claims 1 to 4, and the stabiliser is produced according to the method in accordance with one of claims 5 to 10.
Due to the previously described design of the torsion bar and production of the stabiliser according to the method already described, a simple and particularly economical production of the stabiliser is ensured in an advantageous manner, in addition to a low component weight of the stabiliser and an operationally-safer connection between the torsion bar and stabiliser limb components.
To ensure an especially low component weight, it is provided according to a preferred embodiment of the stabiliser that the torsion bar is formed as a hollow cylinder and that the stabiliser limbs are formed from a light metal alloy, particularly an aluminum alloy.
Further advantages and application options of the invention result from the following description in conjunction with the exemplary embodiment shown in the drawing.
The following is shown:
The stabiliser 10 has a substantially U-shaped structure and comprises a torsion bar 12, which is aligned substantially in the vehicle's transverse direction FQ in the installed state, as well as two stabiliser limbs 14, which are aligned in the vehicle's longitudinal direction FL in the installed state and arranged rotationally fixed at the axial ends 12-1 thereof.
To ensure the lowest weight possible, the torsion bar 12 is hollow-cylindrical here and formed from a fiber-composite material, and the stabiliser limbs 14 are produced from an aluminum alloy.
As shown in
As further shown in
The adhesive coating 16, which is formed as a solid layer, i.e. the adhesive coating 16 is present in a solid physical state, is formed as a reactive hot-melt adhesive here, which can be activated by the corresponding supply of heat.
As
Due to the external-tooth-like contour now carved into the protective layer 18, a form-fitting connection is formed between the torsion bar 12 and stabiliser limb 14 components after joining.
The adhesive-bond connection between the components is established after activation of the adhesive coating 16, i.e. through the supply of heat in this case. To this end, the now-joined stabiliser 10 can also be swapped out so that the reaction can take place completely. The situation after curing is schematically shown in
It has proven to be particularly advantageous in this case that an interruption-free and thus rapid production of the stabiliser 10 is enabled due to the formation of the adhesive coating 16 in the form of a solid layer, i.e. the adhesive coating 16 is present in the solid physical state, because, in contrast to the prior art, liquid adhesive erosion does not occur such that the interruption in production for the removal of the liquid adhesive erosion according to the prior art is no longer necessary. A further advantage is that a cleaner production and thus particularly also a DIN-certifiable production of the stabiliser 10 is enabled due to the elimination of the liquid adhesive erosion.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2017 208 757.9 | May 2017 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/054676 | 2/26/2018 | WO | 00 |
