DE102017112072A1 - Method and device for partially removing a coating applied to a vehicle wheel - Google Patents

Abstract

In a method for partially removing a coating applied to a vehicle wheel (12), a surface to be coated on the vehicle wheel (12) is exposed to a machining beam (30) generated by a radiation source (34) and emerging from a machining head (40), until at least part of the coating in the area of the surface is thermally destroyed. In the thermal destruction resulting gases and / or suspended particles are sucked by a suction device (32) having a suction nozzle (42), at the suction opening (44) bears a negative pressure, which is generated by a first vacuum device (52). According to the invention, the negative pressure applied to the suction opening (44) is temporarily increased by a second vacuum device (54).

Description

BACKGROUND OF THE INVENTION

1. Field of the invention

The invention relates to a method and an apparatus for partially removing a coating applied to a vehicle wheel, in particular in the area of functional surfaces on which later z. B. Radschraubenköpfe or other fasteners.

2. Description of the Related Art

From the prior art it is known to produce vehicle wheels, such as those intended for use on motor vehicles, of metallic materials such as steel, aluminum or magnesium. Such vehicle wheels are provided with a coating comprising one or more layers. The coating serves as corrosion protection for the metallic material and often also to improve the aesthetic effect of the vehicle wheels. Wet coating processes and powder coating processes are commonly used as coating processes for the vehicle wheels. These methods can also be combined with each other. Recently, coating methods such as CVD (Chemical Vapor Deposition) or PVD (Physical Vapor Deposition) for the coating of vehicle wheels before a clearcoat application are also used.

The vehicle wheel has for attachment to a motor vehicle axle on a plurality of functional surfaces on which rest after mounting the vehicle wheel attachment or guide elements. A first group of functional surfaces is formed by screw calottes, which serve the surface conditioning of Radschraubenköpfen. As a further functional surface, a hub ring may be provided, in which when mounting the vehicle wheel on the hub of the motor vehicle axle a hub side provided, circumferential centering collar engages positively to ensure an exact centering of the vehicle wheel relative to the hub. Another functional surface is referred to as a cap seat and serves to receive a cap for covering a central bore on the vehicle wheel. Also contact surfaces for other attached to the vehicle components such as valves, sensors or balancing weights are added to the functional surfaces.

The functional surfaces are - in contrast to the rest of the surface of the vehicle after performing the coating of the vehicle at least substantially free of coatings. In the case of the screw caps, this achieves, for example, that the pairing geometry between the wheel bolt and the vehicle wheel in the area of the screw cap during operation can ensure the necessary frictional engagement. In the case of a coating remaining in the area of the screw cap, the surface pressure between the wheel bolt and the vehicle wheel changes, in particular as a result of setting processes, as a result of which functional reliability can be impaired.

A need to remove an already applied coating on certain areas of the vehicle wheel, there are occasionally for other reasons. If, for example, individual surfaces in subsequent processing steps are to receive a different colored paint or another additional coating, it may be expedient to remove the coating on the relevant surfaces of the vehicle wheel before the additional coating is applied.

From the prior art, it is known to cover the functional surfaces during the coating of the entire vehicle wheel in order to prevent there from hitting and adhering coating material. For this purpose, masking elements such as balls or plugs are placed on the functional surfaces before the coating is carried out and removed again after the coating has been carried out.

The attachment and removal and optionally cleaning of the masking elements, however, involves a considerable additional expense. In addition, in the boundary regions between the masking elements and the coating adhering to the vehicle wheel, there are occasionally undesirable accumulations and breakages of coating material, which may need to be removed in a post-processing step. In addition, the surrounding area of the screw cap, in particular the cylindrical screw hole, is at least partially shaded by the masking elements when carrying out the coating method so that, where appropriate, no satisfactory coating is achieved there and quality criteria with regard to optics and corrosion protection are not met.

From the DE 102 49 999 B3 (equivalent to US 2004/0148050 A1 ) discloses a method for aspirating a powder coating of functional surfaces on vehicle wheels. In this method, first serving as a coating paint powder is applied over the entire surface of the vehicle wheels. In a subsequent process step, the functional surfaces are again freed from the loosely adhering powder with the aid of a suitable suction device before firing of the powder takes place in an oven. The mode of action of this Method is limited to powder coatings; in wet painting or other coating processes, the paint material adheres much more strongly to the vehicle wheels and can not be removed by suction.

From the EP 2 244 846 B1 a method is known in which for partially removing a coating applied to a vehicle wheel, a radiation beam generated by a radiation source is directed to the functional surface to be exposed until the coating in the region of the functional surface is at least partially transferred as a result of heating by the beam in a gas mixture , For sucking off the gaseous mixture which has been fixed during the irradiation, a suction device is provided which, as a negative pressure source, comprises a suction fan, on the suction side of which a flexible suction hose is arranged, which opens into a suction mouthpiece. The suction nozzle with the attached suction hose is moved by means of an actuating cylinder in the vertical direction to allow easy feeding and removal of the vehicle wheel and still be able to take the smallest possible distance to the site of action of the beam during Abtragvorgans. On the pressure side of the suction fan, a filter device is mounted, which filters the released during the machining process by the beam particles from the sucked from the suction nozzle ambient air and thus prevents uncontrolled escape of these particles into the environment.

In order for this known suction device to sufficiently extract the gas mixture released during stripping and the suspended particles contained therein, a very high negative pressure must be present at the suction mouthpiece. In order to produce a sufficiently high negative pressure, large and expensive blowers are required. The investment and energy costs for the suction device are correspondingly high.

SUMMARY OF THE INVENTION

The object of the invention is to provide a method and a device for the partial removal of a coating applied to a vehicle, with the resulting in the thermal destruction of the coating gas and / or suspended particles more efficient, d. H. with lower investment and operating costs.

According to the invention, this object is achieved with regard to the method by a method for partially removing a coating applied to a vehicle wheel, wherein a surface on the vehicle wheel is generated by a radiation source and emerging from a processing head machining beam exposed until at least a portion of the coating in Area of the surface is thermally destroyed. In the thermal destruction resulting gases and / or suspended particles are sucked off by a suction device having a suction nozzle, at the suction of which a negative pressure is applied, which is generated by a first vacuum device. According to the invention, the vacuum applied to the suction opening is temporarily increased by a second vacuum device.

The invention is based on the finding that when using a high-energy machining beam, the coating is destroyed very quickly thermally. Since the surfaces from which the coating is to be removed are typically small and on the order of about 1 cm ² , the stripping of a functional surface using the machining beam usually takes no more than one or two seconds maximum. The high negative pressure that is required for an almost complete extraction of the resulting in the thermal destruction of gases and / or suspended particles must therefore be maintained only during this short period of time at the suction opening.

However, in the time intervals between the individual stripping processes, the negative pressure at the suction opening should not drop to zero, since otherwise the gases and suspended particles sucked off by the suction device can flow back into the environment. For this reason, the first vacuum device generates a preferably constant negative pressure, which is increased only briefly during the actual stripping of the second vacuum device. The first vacuum device thus effectively copes with the base load of the suction, while the second negative pressure device connected only in a second manner covers the peak load required during the short-term stripping. The second vacuum device should be designed for this purpose so that it can briefly generate a very high negative pressure at the suction opening; a permanent maintenance of this high negative pressure, however, is not required.

The radiation source is preferably a laser. In principle, however, are also other sources of radiation, which can generate high-energy electromagnetic radiation, z. B. high power LEDs. Particle radiation such. B. electron beams are generally less suitable because the stripping must be made in most cases in a vacuum.

In the present context, an extraction nozzle is understood to mean any pipe, irrespective of the cross section (for example, circular or rectangular) and material used (metal, plastic, rubber) in which a negative pressure can be built up.

Vacuum refers to the pressure difference to the external pressure. A higher negative pressure in the exhaust or at the suction opening is therefore equivalent to a lower absolute pressure.

Preferably, the negative pressure of the second negative pressure unit is increased at least during the entire duration of the thermal destruction of the coating. However, it is also possible to increase the negative pressure not already in the moment in which the processing beam impinges on the surface for the first time, but shortly thereafter, since it takes a short but not negligible period of time until the coating has heated so far in that it decomposes thermally, thereby releasing gases and / or suspended particles. On the other hand, it may be useful to keep the negative pressure for a short period of time even after the conclusion of the thermal destruction, since gases and / or suspended particles can still emanate from the stratified surface after the processing beam has been switched off. The entire time window during which the negative pressure is increased by means of the second vacuum device should therefore largely cover or completely coincide with the time window during which the surface to be treated is exposed to the machining beam, so that the negative pressure exclusively occurs during the thermal destruction of the coating is increased.

In order to ensure effective extraction of the resulting in the thermal destruction of gases and / or suspended particles, the vacuum applied to the suction opening is in one embodiment at least 4 kPa and preferably at least 6 kPa when both the first vacuum device and the second vacuum device are actuated simultaneously , This high value must be compared with the negative pressure generated by conventional dust extractors, which is typically on the order of about 1.5 kPa.

Since - as noted above - the thermal destruction is very fast, it is sufficient in many cases when the second vacuum device for a maximum of two seconds, preferably a maximum of one second, is operated without interruption to the resulting in the thermal destruction gases and / or aspirating suspended particles.

Conventional fans can be used for the first vacuum device, since comparatively low negative pressures can thus be generated efficiently over a long period of time. However, fans are less suitable for the generation of only a short time required high negative pressure, since they start comparatively slowly and therefore the additional negative pressure at the suction opening can build up only slowly.

In one embodiment, therefore, from the second vacuum means to increase the negative pressure, a gas under pressure is introduced into the suction nozzle via a nozzle arranged in the side wall thereof, that upstream of the nozzle the pressure in the suction nozzle is reduced by entrainment of surrounding air. By injecting high pressure compressed air (or other gas) into the exhaust port near the exhaust port, a short high pressure drop at the exhaust port can be generated very efficiently. In addition, the extracted gases and suspended particles can be discharged via the same lines, cleaned and / or optionally fed to an afterburner as before.

To achieve optimum suction, the nozzle may have an outlet opening which extends annularly over the entire cross-section of the suction nozzle in the manner of a Ringinjektors. Of course, a plurality of nozzles distributed over the cross section of the extraction nozzle can introduce the gas under overpressure into the extraction nozzle.

In principle, however, is also considered, the second vacuum device in such a way that a fan in a vacuum reservoir in the periods between the thermal destruction builds a high negative pressure and the vacuum reservoir is connected during processing via a valve with the suction. The extracted gases and suspended particles then pass through the valve in the vacuum reservoir, from where they can be supplied from the first vacuum device, a filter or a thermal afterburning.

In modern surface treatment plants, the vehicle wheels are conveyed before, during and / or after the thermal stripping on a conveyor system, which may be, for example, a spindle conveyor, a roller conveyor, a belt, a plate belt or other flat conveyor. A multi-axis robot picks up the vehicle wheels from the conveyor system and places them in a processing station so that the processing beam can reach the surface to be processed and the extraction nozzle in the vicinity of this Surface (mostly from the back) can be moved.

Since vehicle wheels usually have a plurality of surfaces on which the coating is to be removed, the coatings of a plurality of spaced-apart surfaces of the vehicle wheel are preferably thermally destroyed sequentially in successive processing steps. The extraction nozzle is moved between the processing steps between the multiple surfaces. For this purpose, for example, can be used with known linear actuators with linear actuators.

Alternatively, if the exhaust nozzle is to remain stationary, the vehicle wheel must be delivered to the stationary suction accordingly. In particular, the vehicle wheel can be rotated between the processing steps about an axis of symmetry of the vehicle wheel. It is exploited that the functional surfaces are often arranged on a concentric to the symmetry axis of the vehicle wheel pitch circle, so that the suction opening of the suction can successively reach all the surfaces to be machined by turning the vehicle about the axis of symmetry. In these cases, it is only expedient to move the suction nozzle in a direction perpendicular to the surface to be stripped so that the suction nozzle does not hinder rotary or other movements of the vehicle wheel.

If, between the processing steps, the extraction nozzle remains stationary and the vehicle wheel rotates, it is generally favorable if the processing head also remains stationary between the processing steps and the processing beam is guided sequentially over the plurality of surfaces with the aid of an adjustable optical deflection element. Alternatively, however, it is also possible to move the entire machining head by means of an adjusting device, as has been explained above for the suction nozzle.

With regard to the device, we have achieved the object mentioned at the outset by a device for partially removing a coating applied to a vehicle wheel, which has a radiation source which is set up to produce a machining beam. Furthermore, the device has a machining head which is set up to direct the machining beam generated by the radiation source onto a surface of the vehicle wheel until at least part of the coating in the area of the surface is thermally destroyed. The device also comprises a suction device, which is adapted to suck off gases and / or suspended particles formed during the thermal destruction. The suction device has a suction nozzle and a first vacuum device, which is adapted to generate a negative pressure at a suction opening of the suction nozzle. According to the invention, the suction device has a second vacuum device, which is adapted to temporarily increase the negative pressure applied to the suction opening.

The advantages and advantageous embodiments mentioned in the method apply correspondingly to the device.

In one embodiment, the second vacuum device comprises an overpressure source and a nozzle connected to the overpressure source, which is arranged in a side wall of the suction nozzle that entrains an air introduced from the nozzle under pressure into the suction nozzle surrounding air and thereby upstream of the nozzle Pressure in the suction reduced.

In another embodiment, the device comprises an adjusting device which is adapted to move the suction nozzle between processing steps in which the coatings of a plurality of spaced-apart surfaces of the vehicle wheel are sequentially thermally destroyed sequentially.

In another embodiment, the machining head has an adjustable optical deflection element with which the machining beam can be guided sequentially over a plurality of surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be explained in more detail with reference to the drawings. In these show:

1 a schematic side view of a processing station with a suction device according to the invention according to a first embodiment;

2 a section of the 1 in which the vehicle wheel, a part of the machining head and a part of the suction nozzle coupled to a wheel bolt hole can be seen;

3 the excerpt from the 2 but after uncoupling the exhaust from the Radschraubenbohrung;

4a to 4d a schematic plan view of vehicle wheels in different rotational positions, wherein the distance of the suction nozzle from the main conveying axis is equal to the radius of the pitch circle on which the Radschraubenbohrungen are arranged;

5a to 5c a schematic plan view of vehicle wheels in different rotational positions, wherein the distance of the suction nozzle from the main conveying axis is smaller than the radius of the pitch circle on which the Radschraubenbohrungen are arranged;

6 a side view of a wheel and a movable machining head according to a second embodiment, in which the suction device has a plurality of suction and the processing head is verschenkbar;

7 one of the 6 corresponding side view and a machining head according to a third embodiment, in which the processing beam can be directed by means of adjustable optical elements on the functional surfaces to be debarked;

8th a schematic plan view of a part of a processing station according to a fourth embodiment, in which a plurality of processing heads simultaneously remove the coating of functional surfaces;

9 a schematic plan view of a stripping plant with three processing stations;

10 a schematic side view of a processing station according to a fifth embodiment, are used in the multi-axis robot for converting the vehicle wheels between different conveyor systems and the processing station.

DESCRIPTION OF PREFERRED EMBODIMENTS

1. First embodiment - construction

The 1 shows a schematic side view of a total with 10 designated processing station according to a first embodiment of the invention. The processing station 10 is designed to be a previously on a vehicle wheel 12 applied coating in the area of several separate areas, which are hereinafter referred to as stripping surfaces to remove.

The vehicle wheel 12 has a central hub bore 14 and several wheel bolt holes 16 pointing to the hub hole 14 concentric pitch circle are evenly distributed. The vehicle wheel 12 gets from a thorn 18 worn on an upwardly pointing end of a spindle 20 is attached. The spindle 20 is about its longitudinal axis 22 rotatable in a known carrier unit 24 a spindle conveyor 26 attached as he is in the DE 10 2011 100 825 A1 the applicant is described. The conveyor axis runs perpendicular to the paper plane.

To the processing station 10 further includes a processing facility 28 with which a processing beam 30 can be directed to the stripping surfaces, and a suction device 32 , which sucks the resulting in the thermal destruction of the coating gases and suspended particles.

The processing device 28 includes a laser radiation source 34 which generates a laser beam. This is via a fiber optic cable 36 and a terminal unit 38 a machining head 40 supplied, from which the laser beam as a focused processing beam 30 exit. By dashed lines is not the processing beam in the figures 30 as such, but the aperture indicated, within which the processing beam 30 using a tool in the edit head 40 arranged scanning optics is pivoted during stripping. The machining head 40 can be at different distances from that through the spindle conveyor 26 predetermined conveying axis at the connection unit 38 be attached. This way, in the workstation 10 also the wheel bolt holes 16 of vehicle wheels 12 be stripped, which are distributed on a pitch circle with a different pitch circle diameter.

In the illustrated embodiment, the adjustment of the machining head takes place 40 at the connection unit 38 manually. In an embodiment explained below, an actuator is provided for this purpose, whereby a manual intervention is superfluous and thereby surfaces can be stripped, resulting in different distances from the axis of symmetry of the vehicle wheel 12 and thus the conveying axis of the spindle conveyor 26 are located.

The suction device 32 includes an elastic extraction nozzle 42 , the end of a suction opening 44 Has. This is located during the stripping below the Radschraubenbohrung 16 where the coating is removed. To the exhaust 42 vertical for coupling to a wheel bolt hole 16 to proceed, is a schematic at 45 indicated actuating device actuated, in which it is z. B. can act to a linear drive. In the illustrated embodiment, the longitudinal axis of the suction nozzle is coaxial with the optical axis of the machining head 40 , along which the machining beam 30 spreads.

The extraction nozzle is via a particle filter 46 with a fan 48 connected in the suction 42 produces a constant negative pressure, which is maintained even in the periods between successive stripping processes. The ventilator 48 is with an exhaust duct 50 connected, which supplies the exhausted exhaust air either a further cleaning, a thermal afterburning or leading to the outside outlet.

The particle filter 46 and the fan 48 are part of a first vacuum device 52 , as it is already known in the art. In contrast to the known vacuum devices that are used for the extraction of gases and suspended particles, the fan is 48 However, much smaller dimensions, since he does not have to generate the negative pressure for reasons to be explained, which is required during a stripping to suck the gases and suspended particles.

This negative pressure during stripping is achieved by connecting a second vacuum device 54 constructed, in the illustrated embodiment, an electromechanically actuated shut-off valve 56 , an accumulator 58 and a pneumatic pressure pump 60 Includes, via an intake manifold 62 compressed air sucked and into the accumulator 58 pressed. The pressure pump 60 is regulated so that it is in the accumulator 58 maintains an overpressure of about 600 kPa. The second vacuum device also includes a pressure line 63 , which is fixed in the illustrated embodiment, on the outside of the suction and until just before the suction 44 enough. Alternatively, the overpressure can also be obtained from a superordinated compressor-supported compressed air system which supplies the entire production site with compressed air.

The 2 shows an enlarged section of the 1 , In the again enlarged section A of 2 It can be seen that the stripping surface on which the previously applied coating is to be removed is a screw cap 70 acting between steps of the wheel bore formed as a stepped bore 16 located. Furthermore, it can be seen in the enlarged section A that at the end of the suction 42 a spring seal is formed, which has a sealing flange 72 includes that of a compression spring 74 when coupling the extraction nozzle 42 to the vehicle wheel 12 to the in the 2 downwardly facing surface of the vehicle wheel 12 is pressed, which the Radschraubenbohrung 16 surrounds. As a result of this seal, air can only through the Radschraubenbohrung 16 in the exhaust pipe 42 flow.

Below the compression spring 74 there is a section of the exhaust 42 in which a ring nozzle 76 is trained. The ring nozzle 76 is over a circular plenum 78 with the pressure line 59 connected to the outside of the exhaust 42 is guided along. The ring nozzle 76 has a substantially conical shape, with the cone to the suction 44 opens. Via the pressure line 63 delivered and about the plenum 78 distributed compressed air therefore flows at an angle of about 45 ° in the exhaust 42 and thereby amplifies the downward flow, that of the fan 48 the first vacuum device 52 is produced.

The 3 shows the in the 2 shown arrangement, but after uncoupling of the suction 42 using the actuator 45 , In this decoupled state, the vehicle wheel 12 using the turning device 68 free around its axis of symmetry, with the longitudinal axis 22 the spindle 20 coincides, be turned. The spring seal then reaches because of the lack of resistance by the vehicle 12 its maximum extent limited by a stop.

To the processing station 10 also belongs in the 1 recognizable camera 64 , which is part of an image processing device. The camera 64 observes in particular the angular position of the vehicle wheel 12 and ensures that this angular position is set so that the surface to be coated is just below the machining head 40 and thus located above the suction opening. For this purpose, the image processing device is provided with a central control unit 66 connected to a rotating device 68 controls. This accesses via a non-illustrated actuator to a disc 67 on, concentric to the spindle 20 attached to this rotation. In this way, the vehicle wheel 12 about its axis of symmetry by means of the turning device 68 be rotated at any angle.

2. First embodiment - function

The following is the function of the processing station 10 explained.

First, the vehicle wheel 12 with the help of the spindle conveyor 26 in his in the 1 transferred shown processing position. The camera 64 detects the vehicle wheel 12 and causes the conveying movement of the vehicle wheel 12 is interrupted at the right moment. In this nominal position of the vehicle wheel 12 along the conveying axis is the axis of symmetry of the vehicle wheel 12 in a place where the distance between the axis of symmetry of the vehicle wheel 12 and the optical axis of the machining head 40 like that Radius of the pitch circle is on which the Radschraubenbohrungen 16 are distributed.

The camera 64 further detects where on the vehicle wheel 12 the wheel bolt holes 16 are located. In general, the vehicle wheel 12 have an angular position in which none of the Radschraubenbohrungen 16 concentric with the optical axis of the machining head 40 is aligned. The control unit 66 calculated on the basis of the camera 64 provided image data the angle of rotation to the vehicle wheel 12 with the help of the turning device 68 must be turned so that one of the wheel bolt holes 16 concentric with the optical axis of the machining head 40 is aligned.

After this adjustment step is completed, the suction nozzle is 42 from the actuator 45 raised, causing the spring seal of the exhaust 42 at the bottom of the vehicle wheel 12 so comes to rest, that the Radschraubenbohrung 16 immediately above the suction opening 44 located. The spring gasket ensures that air only through the Radschraubenbohrung 16 in the paragraph neck 42 can occur.

Now the laser radiation source 34 switched on and the processing beam generated by it 30 with the help of the processing head 40 on the screw cap 70 the wheel bolt hole 16 directed. The processing beam 30 is so focused that the focal plane is at the level of the screw cap 70 located. Using one in the editing head 40 integrated scanning optics, the processing beam 30 be guided over a freely selectable area within an area of about 100 cm ² . The control of the scanning optics is programmed so that the laser beam covers the entire area of the screw cap 70 sweeps. If the processing beam 30 through the wheel bolt hole 16 Through it falls on the exhaust, this is not a problem, since it consists of metal and the energy density of the machining beam 30 insufficient to deform or otherwise damage the metal. Only the coating, which is in a previously performed coating step on the screw cap 70 has heated up, is heated so quickly in a short time that it evaporates. Depending on the composition of the coating, suspended particles may form, which form an aerosol together with the vapors.

So that these gases and suspended particles from the suction device 32 can be sucked, is simultaneously with the switching of the laser radiation source 34 the shut-off valve 56 the second vacuum device 54 open. This allows the high pressure air from the accumulator 58 via the pressure line 63 and the ring nozzle 76 from above into the extraction nozzle 42 inflow, as shown in the enlarged view A of 2 indicated by arrows. The high-velocity compressed air breaks the air in the extraction nozzle 42 with, whereby above the ring nozzle 76 a negative pressure of about 6 kPa is formed. This negative pressure is sufficiently large to completely dissipate the released during the stripping gases and suspended particles.

After about one to two seconds is the stripping of the screw cap 70 completed. The control unit 66 switches the laser radiation source 34 turns off or hides the machining beam 30 from; at the same time also the shut-off valve 56 closed again, so no more compressed air from the accumulator 58 in the exhaust pipe 42 can get. The one from the fan 48 still generated negative pressure is sufficient, however, in the exhaust 42 and the adjoining lines located gases and suspended particles on the particle filter 46 the exhaust duct 50 supply. While the shut-off valve 56 closed, the pressure pump can 52 the second vacuum unit 54 the original pressure in the accumulator 58 restore in the meantime, due to the opening of the shut-off valve 56 had fallen off.

After removing the first screw cap 70 becomes the vehicle wheel 12 using the turning device 68 until turned, until the next Radschraubenbohrung 16 concentric with the optical axis of the machining head 40 is arranged. The above-described steps of stripping using the processing beam 30 and simultaneously increasing the negative pressure at the suction opening 44 by opening the shut-off valve 56 the second vacuum unit 54 then starts again. These steps are repeated until the screw caps 70 all wheel bolt holes 16 are decoated. Then the spindle conveyor promotes 26 the vehicle wheel 12 Continue and bring the following vehicle in the in the 1 shown target position.

The 4a shows different vehicle wheels 12a . 12b . 12c in a plan view taken from the spindle conveyor 26 be encouraged. The vehicle wheels 12a . 12b . 12c differ not only by their outer diameter, but also by the geometry of Radschraubenbohrungen 16 ,

In the 4b is the geometry of the wheel bolt holes 16 for the three vehicle wheels 12a . 12b . 12c shown isolated. The vehicle wheels 12a . 12b each have 4 wheel bolt holes 16 that are evenly distributed around the circumference. The diameter of the pitch circle 80a on which the wheel bolt holes 16 of the first vehicle wheel 12a are arranged, however, is larger than that Diameter of the pitch circle 80b of the second vehicle wheel 12b , At the third vehicle wheel 12c has the pitch circle 80c the same diameter as the pitch circle 80b , On the circle 80c However, there are 5 wheel bolt holes 16 distributed while the second vehicle wheel 12b only four wheel bolt holes 16 Has.

The 4c illustrates the above-described arrangement, in which the optical axis of the machining head 40 and thus also the symmetry axis of the suction opening 44 at a distance to the conveyor axis 82 of the spindle conveyor 26 are equal to the radius of the pitch circle 80 is on which the wheel bolt holes 16 are located. When in the 4c shown rotational position of the vehicle wheel 12 the vehicle wheel must still be turned clockwise by approx. 15 ° until it is in the 4d shown rotational position has reached, in which the Radschraubenbohrung 16 coaxial with the suction opening 44 is arranged.

If an area of a vehicle wheel 12 should be stripped, in which the Radschraubenbohrungen 16 are on a pitch circle with a smaller diameter, so must in the in the 1 to 4 illustrated first embodiment of the machining head 40 manually so on the connection unit 38 be implemented that the distance of the suction opening 44 to the conveyor axis 82 again corresponds to the radius of the then larger pitch circle.

If also the position along the conveyor axis 82 is available as an additional degree of freedom in the adjustment in the adjustment, can with a fixed position of the suction opening 44 the wheel bolt holes 16 be achieved with any Bohrbildgeometrien. The suction opening 44 must then only close enough to the conveyor axis 82 like this 5a to 5c demonstrate. Then it is possible by the combination of a rotation of the vehicle wheel 12 (see. 5b ) and a movement along the conveying axis 82 (see. 5c ) any wheel bolt hole 16 in a position in which they coaxial with the suction opening 44 is aligned.

3. Second embodiment

The 6 shows in a to the 2 ajar representation of a second embodiment of the invention, wherein the machining head 40 shorter and over a flexible optical fiber 84 with the connection unit 38 connected is. In this way, the machining head 40 be pivoted by means of an actuator, not shown. This makes it possible, the processing beam 30 to different places of the vehicle wheel 12 to straighten without this has to be twisted or moved.

In this embodiment, more suction nozzles are also provided, of which in the illustrated section only two suction 42a . 42b , are recognizable. Each of the extraction nozzles 42a . 42b is as educated as this in the 2 is shown. The exhaust pipe 42a . 42b are via a multiple distributor 86 with a common suction line 88 connected.

In this embodiment, after adjustment of the rotational position of the vehicle wheel 12 on all wheel bolt holes 16 simultaneously suction nozzle 42a . 42b Docking. Then the screw caps 70 the wheel bolt holes 16 successively using the machining beam 30 stripped. At each change, the machining head becomes 40 pivoted using the actuator, not shown. At the same time represents a valve arrangement, not shown in the manifold 86 sure that the respective exhaust 42a . 42b with the two vacuum units 52 . 54 connected is.

In this embodiment, the vehicle wheel 12 thus during the sequential stripping of the screw caps 70 the wheel bolt holes 16 can not be rotated, so less time is needed for the entire stripping.

4. Third embodiment

In the in the 7 shown third embodiment is the machining head 40 an adjustable mirror assembly 90 in the beam path of the processing beam 30 downstream. The processing beam 30 exits the machining head 40 out and gets from a plane deflecting mirror 92 deflected by 90 °. The deflection mirror 92 can by means of an actuator, not shown, about a vertical, with the optical axis of the machining head 40 coinciding vertical axis are rotated. The processing beam deflected by 90 ° 30 then meets a second deflection mirror 94 , The second deflection mirror 94 is arranged so that the processing beam 30 exactly on the screw cap 70 the wheel bolt hole 16 meets in order to remove the coating thermally there.

To at an adjacent Radschraubenbohrung 16 To be able to remove the coating, the first deflection mirror 92 rotated through an angle about the vertical axis, which is 360 ° C / n, where n is the number of Radschraubenbohrungen distributed evenly over the pitch circle 16 is. At this point there is a third deflection mirror 95 , of the the processing beam 30 down to the appropriate Radschraubenbohrung 16 directed.

As in this embodiment, only the first deflection mirror 92 can be twisted, the processing beam 30 very quickly to different wheel bolt holes 16 be directed without the comparatively heavy vehicle wheel 12 around the longitudinal axis 22 the spindle 20 must be turned.

The extraction nozzle 42 In this embodiment, not only by means of the actuator 45 movable in the vertical direction, but is so on one about the longitudinal axis 22 the spindle 20 rotatable turntable 95 fastened that he using the turntable 95 fast under every wheel hole 16 can be turned before there the stripping using the processing beam 30 starts. The rotation of the turntable 95 with the suction nozzle attached to it 42 and the rotation of the first deflecting mirror 92 are thus matched to each other at least with regard to the rotation angle and preferably also synchronized in time.

5th fourth embodiment

The 8th shows a schematic plan view of a part of a processing station according to the invention according to a fourth embodiment, in which that of the laser radiation source 34 incoming laser light first in a multiple beam splitter 96 on total 5 Single beams are split, which have optical fibers 98 each a processing head 40 be supplied. This way, in the five wheel bolt holes 16 with whom in the 8th shown vehicle wheels 12 are provided, at the same time the coating of the screw cap 70 be removed. The suction device 32 is there like in the 6 shown trained with the difference that all five exhaust 42 simultaneously with the first vacuum device 52 and the second vacuum device 54 can be connected. The processing station formed in this way 10 Although requires higher investment costs, but allows for a simultaneous and thus very fast stripping the screw caps 70 the wheel bolt holes 16 ,

The 9 shows a schematic plan view of a Entlackungsanlage 100 that have multiple processing stations 10a . 10b . 10c having. The processing heads 40 Each workstation is over optical fiber 36a . 36b respectively. 36c with a common laser radiation source 34 connected. If the partially debonding vehicle wheels 12 Radschraubenbohrungen 16 have, which are arranged on pitch circles with different diameters, the vehicle wheels can also at the soft-like discharge points 102 . 102b so on the workstations 10a . 10b . 10c be distributed, that in each processing station only vehicle wheels 12 are processed, in which the pitch circles have the same diameter. The processing stations 10a . 10b . 10c then need no processing heads 40 and suction supports 42 that are adjustable so that wheel bolt holes 16 at different distances to the axis of symmetry of the vehicle wheels 12 can be edited.

6. Fifth embodiment

The 10 shows a processing station 10 according to a fifth embodiment, wherein the vehicle wheels 12 can not be directly fed and positioned using a spindle conveyor. Instead, the workstation has 10 in this embodiment via a first roller conveyor 110 that the supply of vehicle wheels 12 serves, and a second roller conveyor 112 about which the vehicle wheels 12 after the partial stripping in the processing station 10 be dissipated. To the vehicle wheels 12 from the first roller conveyor 110 and into the machining position below the machining head 40 to transfer, is a first multi-axis robot 114 provided the vehicle wheels 12 picks up and on the opposite side at the in the middle of the 10 shown position with the help of a special wheel gripper 115 settles.

After the processing of a vehicle wheel 12 through the machining head 40 is completely finished, engages a second multi-axis robot 116 the partially coated vehicle wheel 12 and convert it to the second roller conveyor.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10249999 B3 [0008]
• US 2004/0148050 A1 [0008]
• EP 2244846 B1 [0009]
• DE 102011100825 A1 [0046]

Claims (9)

Method for partially removing a vehicle wheel ( 12 ) applied coating in which an area on the vehicle wheel ( 12 ) one of a radiation source ( 34 ) and from a processing head ( 40 ) emerging processing beam ( 30 ) is exposed until at least a portion of the coating in the area of the surface is thermally destroyed, and in the resulting in the thermal destruction of gases and / or suspended particles from a suction device ( 32 ) are sucked off, the suction nozzle ( 42 ), at the suction opening ( 44 ) bears a negative pressure, which from a first vacuum device ( 52 ) is generated, characterized in that the at the suction opening ( 44 ) negative pressure temporarily from a second negative pressure device ( 54 ) is increased. A method according to claim 1, characterized in that the negative pressure during the thermal destruction of the coating is increased. Method according to claim 1 or 2, characterized in that of the second vacuum device ( 54 ) to increase the negative pressure, a gas under pressure so in the exhaust ( 42 ) via a nozzle arranged in its side wall ( 76 ) is introduced upstream of the nozzle ( 76 ) the pressure in the extraction nozzle ( 42 ) is reduced by entrainment of surrounding air. Method according to one of the preceding claims, characterized in that the coatings of a plurality of spaced-apart surfaces of the vehicle wheel ( 12 ) are sequentially thermally destroyed in successive processing steps, and that the exhaust nozzle ( 42 ) is moved between the processing steps between the plural areas. Method according to claim 4, characterized in that the machining head ( 40 ) remains stationary between the processing steps and the processing beam ( 30 ) by means of an adjustable optical deflection element ( 92 ) is guided sequentially over the plurality of surfaces. Device for partially removing a vehicle wheel ( 12 ) applied coating, with a radiation source ( 34 ), which is adapted to produce a machining beam, a machining head ( 40 ), which is adapted to that of the radiation source ( 34 ) produced processing beam ( 30 ) on an area of the vehicle wheel ( 12 ) until at least a part of the coating is thermally destroyed in the area of the surface, a suction device ( 32 ), which is adapted to suck in the thermal destruction of resulting gases and / or suspended particles, wherein the suction device a suction nozzle ( 42 ) and a first vacuum device ( 52 ), which is adapted to a negative pressure at a suction opening ( 44 ) of the extraction nozzle ( 42 ), characterized in that the suction device ( 32 ) a second vacuum device ( 54 ), which is adapted to the at the suction opening ( 44 ) temporarily increase the applied negative pressure. Apparatus according to claim 6, characterized in that the second vacuum device ( 54 ) an overpressure source ( 60 ) and a nozzle connected to the overpressure source ( 76 ), which in a side wall of the suction ( 42 ) is arranged that one from the nozzle ( 76 ) under overpressure in the suction nozzle ( 42 entrained air entrains surrounding air and thereby upstream of the nozzle ( 76 ) the pressure in the extraction nozzle ( 42 ). Apparatus according to claim 6 or 7, characterized by an adjusting device ( 45 ; 95 ), which is adapted to the suction nozzle ( 42 ) between processing steps in which the coatings of a plurality of spaced-apart surfaces of the vehicle wheel are sequentially thermally destroyed sequentially, to move. Device according to one of claims 6 to 8, characterized in that the machining head ( 40 ) an adjustable optical Ablenkelenebt ( 92 ), with which the processing beam ( 30 ) is sequentially feasible over several areas.

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