Patent Application
20100096086
The invention relates to a device for the pre- and/or aftertreatment of a component surface by means of a plasma jet, particularly by means of a jet of an atmospheric plasma, with a plasma head forming a plasma generator with voltage and carrier-gas supply, to which plasma head a nozzle tube of a plasma nozzle is connected, which plasma nozzle encompasses a plasma electrode of the plasma generator, which is electrically insulated with respect to the plasma nozzle, and is connected in terms of flow technology to a working gas channel and has a nozzle head with an outlet opening for the plasma jet at its end opposite to the plasma head, wherein the tip of the plasma electrode is arranged set back in the direction of the longitudinal axis of the plasma nozzle with respect to the outlet opening of the nozzle head.
A device of this type known from WO 2005/117507 (PCT/EP2005/005792) is used for removing an inorganic layer from a component such as e.g. a motor vehicle headlight by means of a plasma jet directed onto the inorganic layer, which plasma jet is to be generated with the aid of an atmospheric discharge in a working gas containing a reactive gas. The working gas channel has a plurality of separate openings which are arranged around the nozzle opening in order to generate a plasma which is free of discharge streams. Thus, a surface, onto which surface an adhesive is to be applied with an independent application apparatus in a subsequent operation, is uncovered e.g. at the edge region of the motor vehicle headlight with the known device, if a cover plate is to be adhesively bonded to the uncovered surface at the edge region of the motor vehicle headlight.
A device with an application unit for at least one component, around which device a plurality of elements for a simultaneous surface pretreatment are externally arranged in an annular manner, is furthermore known (DE 20 2005 00 6 266 U1) for applying reactive plastics onto a component surface. These elements, which may be flaming nozzles, plasma generators, corona discharge heads or spray valves for applying adhesion promoters, are switchable in accordance with the processing direction by means of a control for surface pretreatment, whereby, in one operation, a surface around the application unit can be seamlessly pretreated and the plastic can subsequently be applied onto the pretreated surface by means of an application nozzle of the application unit. The elements for the surface treatment can consist of straight segments and be provided in a square or hexagonal shape around the application unit.
The object of the invention is to make available a device of the type mentioned at the beginning for pre- and/or aftertreatment of a component surface by means of a plasma jet, using which device a defined treatment of the surface and a simultaneous application of at least one adhesive component onto the component surface can be ensured in a space- and time-saving manner and with a high degree of process reliability.
This object is achieved according to the invention, in that
Preferably, a dividing wall which extends over the axial length of the dosing nozzle is preferably provided within the dosing nozzle, by means of which dividing wall the dosing nozzle is subdivided into two longitudinal chambers which have a discharge opening in each case, which longitudinal chambers in each case have an attachment for the separate dosing of two adhesive components which are different from one another, which attachment can be accessed from outside of the plasma head. The outlet opening of the nozzle head for the plasma jet can be formed in a circular manner.
Preferably, the nozzle tube of the plasma nozzle is connected to the plasma head by means of a pivot bearing and is to be set rotating about its longitudinal axis by a motor, wherein the outlet opening of the nozzle head describes a circular path for the plasma jet. Preferably, the dosing nozzle is arranged coaxially in the plasma nozzle.
The device according to the invention ensures, with a high degree of process reliability, a defined plasma pre- and/or aftertreatment of the component surface in combination with the possible application of two adhesive systems which cure at different speeds by positioning a plasma nozzle and a dosing nozzle, which is encompassed by the plasma nozzle, for the adhesive application within a processing head which can be controlled robotically. If a fast fixing is not necessary on the plasma-pretreated component surface, then the subsequent application of only one adhesive onto the processed component surface by means of the dosing nozzle is required.
For low investment costs, the device according to the invention enables a reduction of the process time, enables an improvement of the adhesion between the substrate and adhesive and therefore the achievement of greater strengths and brings about a good reproducibility of the adhesive properties by means of the plasma pretreatment of the surfaces.
Preferred embodiments of the device according to the invention are now explained on the basis of the drawings. In the drawings:
As can be drawn from the
In the case of the first embodiment of the device, the nozzle tube 8 is, as
A plasma electrode 17 of the plasma generator which is electrically insulated with respect to the plasma nozzle 7 extends from the carrier unit 5 of the plasma head 1 in the direction of the longitudinal axis 13 of the device into the nozzle tube 8 in such a manner that the tip 18 of the plasma electrode 17 is arranged set back in the direction of the longitudinal axis 13 of the plasma nozzle 7 with respect to the outlet opening 12 of the nozzle head 11 for the plasma jet.
The nozzle tube 8 of the plasma nozzle 7 is connected in terms of flow technology to a working gas channel 19 which is constructed in the carrier unit 5 of the plasma head 1. As can be drawn from the
The second embodiment of the device arising from
In the use of the device, the jet of the atmospheric plasma generated by the plasma generator is directed, for plasma pre- and/or aftertreatment of the component surface, through the outlet opening 12 of the nozzle head 11 of the first embodiment, which outlet opening is rotating in a circular path, or through the circular outlet opening 12 of the nozzle head 11 of the second embodiment, which outlet opening is fixed, onto the component surface and the latter is treated with the plasma jet. The bead-like application of an adhesive system or of two adhesive systems, which cure rapidly in each case, is then possible in an efficient manner in one operation by means of the dosing nozzle 20 positioned in the plasma nozzle 7, depending on requirements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102008052102.7-54 | Oct 2008 | DE | national |
