GB2483891A

GB2483891A - Method and apparatus for modifying a panel

Info

Publication number: GB2483891A
Application number: GB1016002.6A
Authority: GB
Inventors: Andrew Hedges
Original assignee: Vestas Wind Systems AS
Current assignee: Vestas Wind Systems AS
Priority date: 2010-09-23
Filing date: 2010-09-23
Publication date: 2012-03-28
Also published as: GB201016002D0

Abstract

The method for modifying a panel 10 includes defining a tool travel path 12 on a surface 16 of the panel, mounting a tool 19 on the panel for travel along the tool travel path and then modifying the panel along a modification path 13 by causing the tool to travel along the tool path. The modification path is defined by the tool path. An apparatus suitable for carrying out the method includes a track 14 adapted for mounting on the panel in accordance with a plurality of fiducial points 12 on the panel defining a tool travel path. A tool is mounted for movement along the track for movement along the tool travel path. The mounted tool is adapted to, in use, modify the panel along a modification path defined by the tool travel path. Modifying the panel may take place continuously and may include trimming the panel or delivering adhesive along the modification path. The track may be mounted to the panel by vacuum cups (27, Figure 2B). The panel may be part of a turbine blade or a blade for a wind turbine.

Description

METHOD AND APPARATUS FOR MODIFYING A PANEL

TECHNICAL FIELD

The invention relates to method and apparatus for modifying a panel. Embodiments are particularly suitable for modification of a panel that forms all or part of a turbine blade, particularly a wind turbine blade.

BACKGROUND TO THE INVENTION

Processing of large panels, particularly large structural parts such as a blade for a large wind turbine, is problematic because the available approaches are expensive, have technical disadvantages, or both.

One solution is to rely heavily on skilled manpower, and to fix the structural part in place with skilled personnel carrying out processing operations (such as drilling, trimming, applying adhesive and bonding, and so on) in situ at necessary locations along the structural part.

This leads to high labour costs, and may also lead to irregularity in processing, particularly where a continuous process is required, such as applying a line of adhesive along the length of the structural part.

Another solution is design an automated assembly that is adapted to retain the structural part and to process it along its length. While this would be the preferred solution for processing of relatively small parts, for a structural part that is more than lOm long, say, this will lead to an extremely expensive assembly. The set-up and removal times at the start and the end of the process would also be significant. For large structural parts, such an approach would provide effective processing but at significant costs in infrastructural expense and production time.

It is therefore desirable to provide ways to modify such parts in a way which is well-controlled but flexible and inexpensive.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided a method for modifying a panel, comprising: defining a tool travel path on a surface of the panel; mounting a tool on the panel for travel along the tool travel path; modifying the panel along a modification path by causing the tool to travel along the tool path, wherein the modification path is defined by the tool path.

This approach allows for modification of a panel, particularly a large structural part such as a wind turbine blade, to be carried out effectively and flexibly. An operation which would otherwise require skilled manual labour or a fully automated rig can be carried out efficiently with highly flexible equipment which can be easily reused for processing similar parts, or even for carrying out similar processing operations on differently shaped parts.

It is known to use a drill mounted on a pair of tracks mounted on an aeroplane panel to bring a drill into position without requiring external support (discussed in, for example, WO 2008/091314). Such approaches however teach the need for a separate positioning apparatus in the drill mounting to bring the drill into the correct position on the aeroplane panel.

The method described is particularly effective where modifying the panel takes place continuously along the modification path. Use of the track to define the modification path allows for such processes to be carried out particularly effectively. In such an arrangement, modifying the panel may comprise trimming the panel or delivering adhesive along the modification path.

Advantageously, the step of defining a tool travel path comprises forming a plurality of fiducial points on the panel. Mounting a tool on the panel for travel along the tool travel path may then comprise locating a physical track on to the panel at the fiducial points, and by mounting a tool on to the physical track for movement along it. Advantageously, the physical track is mounted to the panel by vacuum cups.

In an alternative arrangement, mounting a tool on the panel for travel along the tool travel path comprises mounting the tool on a guided vehicle which is mounted on the panel by vacuum cups on caterpillar tracks.

These fiducial points may each comprise a protrusion above the surface of the panel.

Advantageously, the method may then also comprise removal of each protrusion after the step of modifying the panel.

This method is particularly suitable where the panel is a part of a turbine blade, or is specifically all or part of a blade for a wind turbine.

According to a further aspect of the present invention, there is provided an apparatus for modifying a panel, comprising a track adapted for mounting on a panel in accordance with a plurality of fiducial points on that panel defining a tool travel path; a tool adapted to be mounted for movement along the track for movement along the tool travel path; wherein the mounted tool is adapted, in use, to modify a panel along a modification path defined by the tool travel path.

Advantageously, the track comprises a plurality of vacuum cups for mounting the track to the panel. Preferably, the track comprises a toothed rail. In embodiments, the track comprises a power rail for providing power to the mounted tool.

In some embodiments, the tool is mounted on a base comprising one or more actuators for varying the position of a working point of the tool.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example only, by reference to the following drawings in which: Figure 1 shows a modification of a panel using methods and apparatus according to an embodiment of the invention; Figures 2A and 2B show the track used in the apparatus shown in Figure 1 in plan and sectional views respectively; Figure 3 shows the use of a different tool in the arrangement of Figure 1; and Figures 4A to 4E show different stages in a method of modifying a panel according to embodiments of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 shows modification of a panel 10 using methods and apparatus according to an embodiment of the invention. The panel 10 may be, for example, all or part of a turbine blade, such as a wind turbine blade.

A tool travel path is defined by a series of fiducial points 12 on the panel -these are formed as a series of regularly shaped protrusions, by approaches discussed below. These fiducial points 12 serve to locate a flexible track 14, which is mounted on the surface 16 of the panel 10. A tool base 18 is mounted on the flexible track so that it moves along the tool travel path defined by the fiducial points 12. The tool base 18 supports a tool -in this case, edge trimming tool 19 -which modifies the panel 10 along a modification path -in this case, the modification path is the trimmed edge position 13 of the panel 10. As can be seen from Figure 1, the panel edge has been trimmed to the trimmed edge position 13 along part of the panel and has not yet been trimmed along another part of the panel (as can be seen from the direction of travel A of the tool along the flexible track 14).

Figures 2A and 2B show the track illustrated in Figure 1 in more detail. Figure 2A shows the track 14 in a plan view. In addition to the main rails 21 and 22 of the track 14, there is provided a toothed rail 23 which can be used to move a tool base in a well controlled manner along the track. A power rail 24 is also provided to power the tool base. The skilled person will appreciate that conventional technology choices may be made for both power and drive of the tool base along the track. The fiducial points 12 are located within location points 25 formed as a part of the track 14 but disposed to the side, away from the track rails.

Figure 2B shows a sectional view of the track. In addition to showing the main rails 21, 22, the toothed rail 23 and the power rail 24, this shows a fiducial point 12 formed on the surface 26 of the panel. The fiducial point 12 in this arrangement fits through an aperture 25 acting as a location point for the track 14 -as the skilled person will appreciate, other structures may be used to locate the track at a series of points.

Figure 2B also shows a mechanism for locating the track 14 on to the surface 26 of the panel.

This is achieved with a number of vacuum cups 27 disposed along the length of the track 14.

These may be used to fix the track 14 on to the surface of the panel sufficiently firmly to allow tool bases to be moved reliably and accurately along the track 14 without unacceptable movement at the tool, but in such a way that the track 14 may subsequently be removed from the surface 26 of the panel without affecting it. Vacuum cup spacing of approximately 200mm can be used in an effective track structure.

The track needs sufficient flexibility to be shaped to match the fiducial points, but also requires sufficient rigidity to enable tool bases to be located accurately and stably along the track. While the skilled person will appreciate which materials choices will be suitable for these requirements, typically this will involve a polymeric base material reinforced by metal strands or plates. The spacing of fiducial points -and hence of location points on the track -may be chosen to match the geometrical complexity required. For example, a complex geometry or demanding requirements may require fiducial point spacing of 100mm, whereas for a straight edge a fiducial point spacing of 1000mm may be satisfactory.

A track -and associated fiducial points -may be prepared jointly as a template for a particular design. Alternatively, a standard track may be provided, with the track position determined by regularly spaced fiducial points.

Other tools can be used in this arrangement, as Figure 3 illustrates. Figure 3 shows the use of an adhesive delivery system including an adhesive applicator 39 mounted on the tool base 18, with adhesive provided from an adhesive delivery system 35 mounted on rails to follow the movement of the tool base 18 along the track 14, with a flexible pipe 37 connecting the adhesive delivery system and the adhesive applicator 39 and its mounting. The applicator tool modifies the surface by providing an adhesive line 33 along the surface of the panel.

This arrangement can be seen to be particularly suitable for modification processes that take place continuously along a line of modification (such as edge trimming and providing a line of adhesive), as the motion of the tool base along the track is translated reliably into a line of modification along the surface.

The process of modifying a panel is illustrated with respect to Figures 4A to 4E. Figure 4A shows the moulding of the raw panel part. Fiducial points are moulded into the part to define the tool travel path. Figure 4B shows the mounting of the flexible tracks on to the fiducial points. Figure 4C illustrates the next step, which is the location of the tool base on to the flexible track for translation along the tool travel path in the manner illustrated in Figures 1 and 3. Figure 4D indicates the removal of the flexible tracks after the modification operation is complete, at which point the panel part is almost in its finished state. At this stage, however, the fiducial points are still present in the panel -this may be highly undesirable if, for example, the panel is required to have certain aerodynamic properties (as would be the case for an aeroplane part or a turbine blade). Figure 4E shows the progressive removal of the fiducial points to leave a flat surface -as is shown in Figure 4E, the fiducial points may in fact be moulded with an undercut in such a way as to facilitate their removal to leave a flat surface.

Alternatives exist to the moulding of the fiducial points as protrusions. For example, the fiducial points may be moulded as recesses, such that fiducial points can be screwed in to the recesses for mounting the tracks, and flats screwed in to the recesses after the tracks have been removed to provide a flat surface (using a similar principle to that used for an optical

bench, for example).

Alternative approaches to providing a tool travel path on the panel may be employed in embodiments of the invention. One possibility is for the tool base to be mounted on caterpillar tracks which themselves provide a vacuum cup connection to the panel. Fiducial points can then be provided as before to guide the vehicle as it travels along the surface. This requires some additional complexity in the tool base -it needs to be able to recognise and follow the path defined by the fiducials, which will require it to contain appropriate sensors (such as an optical sensor) and steering responsive to the sensors, but it removes the need for laying and subsequently removing the track.

In some embodiments, it may be desirable for a tool working point to be further controlled (for example, to achieve a shape profile that could not simply replicate the profile of the track or other tool travel path). In such cases, the tool base may contain one or more actuators to translate the tool such that the working point can be varied within a limited range from that defined by the tool travel path. This may be achieved by a conventional actuator-driven tool mounting and with the use of conventional control circuitry and software, as the skilled person will appreciate -the variation may be, for example, according to a predetermined pattern of modification defined with reference to the tool travel path.

As the skilled person will appreciate, other modifications may also be made within the scope of the invention as claimed.

Claims

CLAIMS1. A method for modifying a panel, comprising: defining a tool travel path on a surface of the panel; mounting a tool on the panel for travel along the tool travel path; modifying the panel along a modification path by causing the tool to travel along the tool path, wherein the modification path is defined by the tool path.
2. A method as claimed in claim 1 wherein modifying the panel takes place continuously along the modification path.
3. A method as claimed in claim 2 wherein modifying the panel comprises trimming the panel along the modification path.
4. A method as claimed in claim 2 wherein modifying the panel comprises delivering adhesive along the modification path.
5. A method as claimed in any preceding claim, wherein defining a tool travel path comprises forming a plurality of fiducial points on the panel.
6. A method as claimed in claim 5, wherein mounting a tool on the panel for travel along the tool travel path comprises locating a physical track on to the panel at the fiducial points, and by mounting a tool on to the physical track for movement along it.
7. A method as claimed in claim 6, wherein the physical track is mounted to the panel by vacuum cups.
8. A method as claimed in any of claims 5 to 7, wherein the fiducial points each comprise a protrusion above the surface of the panel.
9. A method as claimed in claim 8, wherein the method further comprises removal of each protrusion after the step of modifying the panel.
10. A method as claimed in any of claims 1 to 9, wherein the panel is a part of a turbine blade.
11. A method as claimed in claim 10, wherein the panel is all or part of a blade for a wind turbine.
12. A method as claimed in claim 5, wherein mounting a tool on the panel for travel along the tool travel path comprises mounting the tool on a guided vehicle which is mounted on the panel by vacuum cups on caterpillar tracks.
13. Apparatus for modifying a panel, comprising: a track adapted for mounting on a panel in accordance with a plurality of fiducial points on that panel defining a tool travel path; a tool adapted to be mounted for movement along the track for movement along the tool travel path; wherein the mounted tool is adapted, in use, to modify a panel along a modification path defined by the tool travel path.
14. Apparatus as claimed in claim 13, wherein the track comprises a plurality of vacuum cups for mounting the track to the panel.
15. Apparatus as claimed in claim 13 or claim 14, wherein the track comprises a toothed rail.
16. Apparatus as claimed in any of claims 13 to 15, wherein the track comprises a power rail for providing power to the mounted tool.
17. Apparatus as claimed in any of claims 13 to 16, wherein the tool is mounted on a base comprising one or more actuators for varying the position of a working point of the tool.