DE102007009641A1 - Milling tool i.e. die set, guiding device, has guide rail arrangements including curved guideway distribution adapted to curvature of surface of workpiece, where one of arrangements is longitudinally extended in direction - Google Patents

Abstract

The device (10) has a guide rail arrangement (18-1) that is longitudinally extended in a direction (x) and provided for moving a tool holder (16) in the direction. A frame (12) has another guide rail arrangement (12-1) that is longitudinally extended in another direction (y) running transverse to the direction (x) for moving the arrangement (18-1) in the direction (y). The arrangements have a curved guideway distribution adapted to the curvature of a surface of a workpiece. The frame is lockable at the surface.

Description

The The invention relates to a device for guiding a milling tool according to the preamble of claim 1 and the use of a such device.

Such a tool guide is for example from the DE 43 20 750 A1 known. In this publication, to repair a component made of carbon fiber reinforced plastic (CFRP), it is proposed to guide a milling cutter over a curved component surface by means of the tool guide in such a way as to create a so-called puncture of the damage area around the damage center (eg hole). By subsequent grinding a conical Schäftungsfläche is formed, on which then a repair patch is glued.

The Known tool guide is relatively complicated and bulky. The lockable on the component surface The frame of the tool guide consists of several two-legged ones Articulated arms (eg "tripod"), their positions and joint positions first carefully adjust and fix are, so in the center of the device on inner joint thighs The bearing housing hinged to the frame is properly oriented and is positioned. The actual tool holder for the milling tool is via an adjustable pivot lever assembly connected to the bearing housing. After a once made Setting the tool guide can be the tool holder with the milling tool only along a circular path around the centrally arranged bearing housing led around become.

The Result of the known repair is not in all applications satisfactory. In addition, the operation requires the Tool guide a certain experience to get as close as possible well-defined relationship (ratio between the radius of the cone surface and the depth of the cone surface or component thickness). Inaccuracies of the form of business would result in an "adaptable" Repair material is required, for example, after the Contribution to the stock still in a separate step shape-fitting and curing repair patches.

It It is an object of the present invention to provide a simple and compact to provide constructed tool guide of the type mentioned.

These The object is achieved by a device for guiding a milling tool solved according to claim 1. The dependent claims relate to advantageous developments of the invention.

For the invention is essential that one in a first direction elongate first guide rail assembly for mobility the tool holder is provided in the first direction that the frame one in a transverse to the first direction second Direction elongated second guide rail assembly to the mobility of the first guide rail assembly in the second direction includes, and that the first guide rail assembly and / or the second guide rail arrangement on the curvature of the surface to be machined adapted curved Guideway course possesses.

Different as in the known tool guide described above can with the tool guide according to the invention in a simple way virtually any trajectories for the tool holder including milling tool can be realized. Essential for this is a "functional coupling or Series connection of "two transversely oriented guide rail assemblies. For the invention is also essential that - different as in a conventional "x-y-guide" - at least one of the two guide rail assemblies to the Curvature of the surface to be processed adapted has curved guideway course.

The concrete design of the milling tool used is in Scope of the invention of subordinate importance. It can be beneficial known per se, suitable for machining tools, used in particular rotating cutting tools become.

If the surface of the workpiece to be machined curved in only one direction (eg cylindrical surface section), so it is sufficient if either the first or the second guide rail assembly with the adapted curved guideway course is provided. For surfaces that are in two directions curved (eg spherical surface section) have accordingly both guide rail arrangements one adapted curved guideway course. If the surface is curved in one direction only is or in a curvature in two directions no rotational symmetry the surface is relative to a normal, so is for an adjustment of the (curved) "milling level" to the (curved) workpiece surface the entire tool guide according to the azimuth angle to orient.

With regard to the most universal usability of the tool guide, an embodiment is particularly advantageous in which at least one of the two guide rail arrangements easy (eg after loosening a screw) is interchangeable. For example, an assortment of guide devices of different length and / or curvature can be provided, from which a device suitable for the relevant workpiece surface is selected and used as first or second guide rail arrangement of the tool guide.

Regarding the locking of the frame on the workpiece surface For example, the device may be a squeegee assembly include, in particular several distributed over the circumference of the frame arranged and preferably hingedly connected to the frame suction cups.

In an embodiment, it is provided that the first guide rail assembly a pair of mutually parallel guide rails includes. The term "parallel to each other" is to be understood as meaning that under it also an identically curved course of the both guide rails falls.

With a curvature of the guide rail pair leaves in a simple manner, a corresponding curvature of the Realize the management trajectory. It should be noted, however, that a curved track course by no means necessarily a corresponding curvature of the relevant Guide rails required. For example, at a straight guide rail curved to a certain extent Guideway through a correspondingly curved guide projection or a correspondingly curved guide groove (z. B. slot) be realized.

If a guide rail assembly of a pair of parallel is formed to each other extending guide rails and should be interchangeable, it can be provided that the two Guide rails of the pair are firmly connected.

In A preferred embodiment provides that the frame of four paralielogrammartig, in particular rectangular, formed interconnected frame parts, of which two Gegebüberliegende frame parts, the second guide rail assembly wear or train. In this case, the first and second Directions of the first and second guide rail assemblies defined by the two "parallelogram directions".

Regarding a simple screwing and interchangeability of frame parts, which z. B. form a guide rail assembly or as "spacers" between two guide rails serve a guide rail pair, it is particularly advantageous when the frame has an overall rectangular shape.

at a parallelogram-like, in particular rectangular frame According to a further development, that in the Course of at least one of the four frame parts at one or more Make in the longitudinal course of a device or marking provided which is used as a "positioning aid" for positioning the tool holder including tool with respect to the frame and / or for positioning the entire device with respect to useful for the workpiece surface to be machined is.

In An embodiment provides that the guideway course the second guide rail assembly through slots in opposite frame parts of the frame is predetermined. The course of the slots then determines whether and to what extent, if applicable, to what extent Guideway is curved.

In a particularly advantageous for many applications Embodiment is provided that one with the tool holder connected linkage for controlling the movement of the tool holder relative is provided to the frame. In this regard, it should be remembered that in the device according to the invention by the Coupling of two guide rail assemblies in transverse mutually extending directions a mobility of the tool holder is created along a surface. You want However, the tool holder within this achievable area along a given, lying in this area Move tool guide path, so the corresponding Drive and / or a corresponding forced operation of the tool holder realized with such a linkage in a simple manner become.

In a preferred development of this linkage control the tool holder movement is provided that the tool holder firmly connected to one end of at least one control rod, whose other end extends out of the area bounded by the frame and driven there during the milling process and / or forced.

For example, the motion control linkage may form part of a mechanical copying unit for defining a tool guideway based on a template. As far as the formation of the linkage or the template is concerned, it is advantageously possible to make use of the prior art from the area of so-called copy milling machines. In the simplest case, the copying unit can provide that a trajectory defined by the template used is imaged 1: 1 on the tool guideway. However, it should not be ruled out that the copying unit, in the manner of a so-called pantograph, provides for an imaging ratio not equal to 1: 1.

at a definition of the tool guideway based on a Template may be provided that at least a portion of the Frame on its outside fasteners for releasable Attachment of the template to be used has.

By the use of the device according to the invention can advantageously in principle any milling on workpiece surfaces, in particular curved Workpiece surfaces made in a simple manner become.

A preferred use is, for example, the shanks of Workpiece.

All In general, the term "stocking" refers to one on one Workpiece formed recess (or the corresponding Operation), whose depth to the center of the recess towards cone increases. For this purpose, the Schäftung z. B. by Milling off gradually increased in diameter concentric circular rings are created. In the sense of a "hand-milling unit" can Here, an operator manually the tool holder on the respective Circular path around the center of the movement, where this circular path z. B. by means of a copying unit of the above Type of template defined (enforced).

Around in this case as exact as possible cone shape of the milled It is conceivable that for gradually increasing in diameter (but reduced in the milling depth) Fräsgänge to use a milling tool, which at every milling cycle already the cone shape of the respective circular ring area accordingly the desired relationship works out. Alternatively, one can be made by milling out step by step in diameter enlarged concentric annulus areas created "stepped stance" to achieve a cone shape be post-processed accordingly (eg by grinding).

Of the The term "tiered stance" is intended to express that the recess depth, although towards a center of the recess increases, but the recess surface is not cone-shaped but at least one stage. As part of a bottom yet described special application of fiction, contemporary Device or the schäftungsverfahrens accomplished thereby such a tiered stocking is of particular advantage.

Both for the formation of a tapered shank and the formation of a stepped shank, provision may also be made for the shank to be created by milling out progressively reduced-diameter concentric circular areas, as already mentioned above DE 43 20 750 A1 is proposed. Also in this case, the tool holder movement can be forcibly limited to the desired circle area by means of a copying unit.

• – Schäftung des Bauteils im Bereich einer Schadensstelle, und
• – Einbringung von Reparaturmaterial in die Schäftung.

A preferred use of the device according to the invention consists in the repair of a component, in particular z. B. a fiber composite component, comprising the steps:

• - Lining of the component in the area of a damaged area, and
• - Carrying of repair material in the Schäftung.

This type of repair is as such from the above DE 43 20 750 A1 However, it is particularly convenient to carry out by means of the device according to the invention.

According to one Continuing this repair procedure is provided that the Stake is formed with a step surface and as the repair material with a corresponding step surface prefabricated repair piece in the socket is introduced.

The Forming a Schaftung with a predetermined step surface is often easier and more precise in practice as the formation of a corresponding conical surface. The Insertion of a prefabricated repair piece with a corresponding step surface therefore requires, if at all, at most slight form adaptations. With sufficient precise training of the graded stock as well the prefabricated repair piece is advantageous one "flush" repair of damage possible, in particular even without a separate step to post-processing the stock or for adjusting the shape of the repair piece. Furthermore is the component site repaired according to the invention tend to be more resistant to later occurring mechanical loads.

A preferred application of the invention is for the repair of structural components in the aerospace industry. It can both flat and curved components or component surfaces be repaired, in particular z. B. plate or cup-shaped Components. In the component to be repaired, it may, for. B. order a curved in one or two directions aircraft fuselage shell act.

In one embodiment, it is provided that the component is a fiber composite component (eg CFRP) or a light metal component.

The Step surface can be rounded and / or abgefarste step edges have, for example, thereby notch effects and mechanical To reduce stress peaks at the finished repair site.

The Step surface can z. B. have at least two stages. Preferably, the step surface has at least three stages on.

each Stage may consist of a ring-shaped, in particular circular, around the damage center and essentially parallel to the component surface existing recessed area, which over an annular closed and substantially orthogonal to the component surface extending edge surface with a higher or lower, again essentially extending parallel to the component surface recess surface connected is.

In an embodiment of the repair method is provided that as a repair piece a hard or hardened Part, for example of the same material as the component itself, is used. Such a "finished" repair piece, can in particular z. B. by gluing in the Schäftung on the component be attached.

The Invention will be described below with reference to embodiments further described with reference to the accompanying drawings. They show:

1 is a perspective view of a tool guide for milling a workpiece surface,

2 is a perspective top view of the workpiece to be machined,

3 is one of the 2 corresponding view after a locking of the tool guide of 1 on the surface of the workpiece from 2 , and

4 is one of the 1 corresponding view of a tool guide according to another embodiment.

1 shows one below as a tool guide 10 designated device for guiding a milling tool (not shown).

2 shows the workpiece to be machined in this example, namely a substantially curved in one direction aircraft fuselage shell 90 , The hull shell 90 indicates on its curved, here outer surface 92 a damaged place 94 which is to be eliminated by a per se known repair method in which the hull shell 90 first in the area of the damaged area 94 is repaired and then introduced repair material in the Schaftung and glued, for example, or anchored in any other way.

This repair is done using the in 1 illustrated tool guide 10 carried out.

3 shows the hull shell 90 after placing and securing the tool guide 10 on the surface 92 in the area of the damage site 94 ,

Coming back to 1 includes the tool guide 10 for guiding the milling tool for machining the fuselage shell 90 one on the surface 92 the hull shell 90 lockable frame 12 consisting of a rectangle, each elongated frame parts 12-1 . 12-2 . 12-3 and 12-4 , The frame is locked to the workpiece surface by suction feet 14 , one of each in the area of each corner of the overall rectangular frame 12 is arranged.

With the frame 12 connected and disposed within the same is a tool holder 16 for holding and positioning the milling tool (not shown) in a vertical direction z during machining of the workpiece surface.

In the figures, orthogonal to the vertical direction z and orthogonal to each other oriented lateral directions x and y are also drawn, which the extension directions of the frame parts 12-3 and 12-4 (x direction) or 12-1 and 12-2 (y direction).

The tool guide 10 further comprises a pair of linearly elongated guide rods in the x-direction 18-1 and 18-2 , on each of which one at the bottom of the tool holder 16 mounted glider 20 rode. Through this "x-guide" is the tool holder 16 in an area between the frame parts 12-1 and 12-2 relative to the frame 12 movable in x-direction.

The ends of the guide rods 18-1 and 18-2 run in pairs in oblong holes 22-1 and 22-2 on the inside of the frame part 12-1 respectively. 12-2 , Just before the ends of the guide rods 18-1 and 18-2 from these interspersed connecting struts 24-1 and 24-2 ensure a parallel course of the two guide rods 18-1 and 18-2 ,

The frame parts extending in the y-direction 12-1 and 12-2 form with their respective slotted holes 22-1 respectively. 22-2 a second guide rail arrangement for y-mobility of the guide rods 18-1 and 18-2 formed first guide rail assembly which the tool holder 16 stored movable in the x-direction.

Unlike in a conventional "xy-guide" is in the example shown, however, the peculiarity that extending in the y-direction slots 22-1 and 22-2 define a slightly curved guideway path for the y-motion.

Due to the functional series connection of the x-guide and the slightly curved y-guide results in a mobility of the tool holder 16 within the frame 12 bounded area along a corresponding curved surface. The shape of this intended for the tool holder movement surface is due to the surface shape of the workpiece to be machined, here the surface 92 the hull shell 90 , customized. For the purpose of milling out a shank in the area of the damaged area 94 For the most part, it is expedient for the surface accessible to the tool holder movement to be more or less exact like the shape of the workpiece surface 92 to provide in the area to be processed.

In the described application example of the approximately cylindrical shape of the surface 92 So there is the curved course of the slots 22-1 and 22-2 the corresponding surface course at the point of damage 94 in the y direction again.

The at the damage site 94 trainee Schäftung can be created for example by milling away gradually changed in diameter concentric circular areas or circular ring areas. The lateral drive of the tool holder together with the inserted milling tool required for sweeping the regions to be milled takes place manually in the exemplary embodiment shown by an operator, wherein the circular region or annular region to be milled out advantageously by a mechanical copying device of the tool guide 10 is defined.

The copying device used in the illustrated embodiment consists of a fixed to the tool holder 16 connected and in a lateral direction (here: x-direction) from the frame 12 out extending control rod, on which one of them in the z-direction downwardly projecting Abtastzapfen 28 is arranged, and one on a frame part (here: frame part 12-2 ) arranged template holder 30 for fixing a template 32 on the tool guide 10 ,

In the illustrated embodiment is as a template 32 a plate oriented in the xy plane with a recess defining the desired tool holder travel path or toolholder movement surface area, respectively.

At the in 1 illustrated template 32 is z. B. provided a circular recess. This allows the operator of the tool guide 10 in a simple manner, namely by scanning the recess edge or alternatively the entire recess surface with the scanning pin, in the ratio 1: 1, a corresponding movement path or movement area for the tool holder 16 comply.

After replacing the template 32 Accordingly, in another operation, a further concentric circular path or a further concentric circular surface area can be worked out by another template with a larger or smaller recess. Before each further Fräsgang can be used on the milling tool or the tool holder 16 a modified milling depth (in z-direction) can be set.

In summary, the described tool guide 10 a "geometry-adaptive hand-milling unit", by means of which an exact and reproducible machining on curved structures can be performed. The device is particularly suitable for processing fiber composite components (eg CFRP) or light metals, for example in aerospace engineering. Certain predefined areas on flat or curved structures can be machined or removed. In particular, for the application of the repair of the relevant component by means of milling processing both a certain cut away removed and a stepped Schaftung be formed. A drive unit including a milling tool of commercially available type can be attached to the tool holder 16 be mounted on which also the height delivery (z-direction) is realized. The frame parts 12-1 and 12-2 or their guide grooves or slots 22-1 and 22-2 are adapted to the shape (geometry), ie the curvature or the radius of curvature of the structure to be processed. For accurate and reproducible processing, a copy unit is integrated into the design. This gives the possibility of using predetermined mold plates or templates and the copy rod 26 to depart defined tracks. After placing the tool guide 10 on the area to be repaired their orientation can be simplified by positioning (position and Azimutwinkelstellung).

In the illustrated embodiment, befin the z. B. in each case halfway the frame parts 12-1 and 12-4 such centering aids 34-1 respectively. 34-2 , The locking of the tool guide 10 on the fuselage shell segment to be repaired takes place in a simple manner on the suction feet 14 , which also optimally the curvature or the shape of the surface to be machined 92 to adjust. The device can with small dimensions and low weight as a mobile milling unit and thus z. B. be used directly at the place where a damage to be repaired occurs.

at the following description of another embodiment become the same reference numbers for equivalent components used, each supplemented by a small letter "a" to distinguish the embodiment. It will essentially only to the differences to the already described Embodiment received and otherwise hereby expressly to the description of the preceding Reference example.

4 shows a slightly modified tool guide 10a which in construction and function essentially the above with respect to 1 corresponds described tool guide.

A special feature of the tool guide 10a However, it is not just the frame parts 12a-1 and 12a-2 realized y-guide rail assembly has a curved track course, but also by a pair of guide rods 18a-1 and 18a-2 realized x-guide rail arrangement. This is accomplished in the illustrated embodiment, characterized in that the guide rods 18a-1 and 18a-2 Although parallel to each other, but each slightly curved in the x-direction.

Due to this curved bar run are also on the bottom of the tool holder 16a provided sliders for each of the two guide rods 18a-1 and 18a-2 executed twice. In 4 are the two gliders 20a-1 and 20a-2 for storage of the tool holder 16a on the guide rod 18a-2 to recognize.

In the 4 illustrated tool guide 10a is thus particularly suitable for adapted machining of a workpiece surface curved in two directions.

The described tool guides 10 ( 1 ) and 10a ( 4 ) can each be provided from a modular "kit" containing different pairs of frame parts and guide rods, from which in loading case the currently required geometry (size of the frame and curvatures in the x and y direction) is created.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 4320750 A1 [0002, 0029, 0031]

Claims (9)

Device for guiding a milling tool for machining a curved surface ( 92 ) of a workpiece ( 90 ), comprising one on the surface ( 92 ) of the workpiece lockable frame ( 12 ) and one in the frame ( 12 ) bounded area relative to the frame ( 12 ) movable tool holder ( 16 ) for the milling tool, characterized in that in a first direction (x) elongated first guide rail assembly ( 18-1 . 18-2 ) for the mobility of the tool holder ( 16 ) in the first direction (x) is provided that the frame ( 12 ) comprises a second guide rail arrangement elongated in a second direction (y) running transversely to the first direction (x) ( 12-1 . 12-2 ) to the mobility of the first guide rail arrangement ( 18-1 . 18-2 ) in the second direction (y), and in that the first guide rail arrangement ( 18-1 . 18-2 ) and / or the second guide rail arrangement ( 12-1 . 12-2 ) one to the curvature of the surface to be processed ( 92 ) has adapted curved guideway course. Apparatus according to claim 1, comprising a squeegee assembly ( 14 ) for locking the device to the surface ( 92 ) of the workpiece ( 90 ). Device according to one of the preceding claims, wherein the first guide rail arrangement ( 18-1 . 18-2 ) and / or the second guide rail arrangement ( 12-1 . 12-2 ) comprises a pair of mutually parallel guide rails. Device according to one of the preceding claims, wherein the frame ( 12 ) of four parallelogram, in particular rectangular, interconnected frame parts ( 12-1 . 12-2 . 12-3 . 12-4 ) is formed, of which two opposing frame parts ( 12-1 . 12-2 ) support or form the second guide rail assembly. Device according to one of the preceding claims, wherein the guideway course of the second guide rail arrangement ( 12-1 . 12-2 ) through slots ( 22-1 . 22-1 ) in opposite frame parts of the frame ( 12 ) is given. Device according to one of the preceding claims, wherein a with the tool holder ( 16 ) connected linkage ( 26 ) for controlling the movement of the tool holder ( 16 ) relative to the frame ( 12 ) is provided. Apparatus according to claim 6, wherein the linkage ( 26 ) a part of a mechanical copying device for defining a tool guideway based on a template ( 32 ). Use of a device according to one of claims 1 to 7, for shanking the workpiece ( 90 ). Use according to claim 8, wherein as a workpiece ( 90 ) a component to be repaired, in particular fiber composite component, is provided.