WO2011138481A1

WO2011138481A1 - Tool and method for the automatic remote application of strips of fibre-reinforced polymer tape, comprising the dispensing of epoxy adhesive

Info

Publication number: WO2011138481A1
Application number: PCT/ES2011/000145
Authority: WO
Inventors: Juan Carlos Gonzalez Victores; Santiago Martinez De La Casa; Albeto Jardon Huete; Carlos Balaguer Bernaldo De Quros
Original assignee: Universidad Carlos Iii De Madrid
Priority date: 2010-05-03
Filing date: 2011-04-28
Publication date: 2011-11-10
Also published as: ES2370666B1; ES2370666A1

Abstract

The invention relates to a tool (1) and a method for the automatic remote application of strips of non-adhesive fibre-reinforced polymer (FRP) tape (12) for the covering of curved or flat surfaces (20) of construction elements, such as tunnel vaults, parabolic arches, catenary arches and other non-funicular arches typical of bridges and many modern constructions. The tool includes a frame having the following elements coupled thereto, namely: a pressure roller (2); a means for dispensing FRP tape via guide rollers (6a, 6b, 6c, 6d); a drive roller (5); and a means for dispensing adhesive so as to coat said tape, such that by moving the tool over the surface, power is generated and transmitted to an FRP-tape-dispensing means, adjusted such that the FRP dispensing speed is substantially similar to the tool (1) movement speed, thus allowing an automatic remote application method.

Description

TOOL AND REMOTE AUTOMATIC APPLICATION METHOD OF TAPE STRIPS WITH POLYMER REINFORCED WITH FIBERS, WITH DISPENSATION OF

EPOXIC ADHESIVE

5 Technical field of the invention

The invention provides a tool and a method for the automatic application of strips of tape with fiber reinforced polymer, of the type that lack adhesive in the coating of flat surfaces and / or curves of construction elements such as tunnel vaults, arches parabolic, 0 catenaries and other antifunicular characteristic of bridges and many modern constructions.

State of the Art

The present invention relates to techniques for coating elements in constructions with fiber reinforced polymer. These plastics5 (FRP, Fiber-reinforced polymer) are made of a material composed of a matrix of a polymer reinforced with fibers such as fiberglass, carbon fiber, aramid or similar and allow to protect the surfaces in constructions or elements that make up these constructions.

In the state of the art, manual FRP tape applicators are known, or which imply an inefficient, expensive and slow investment of resources: that is, to apply an FRP tape, an operator has both pieces of a smooth, cylindrical wooden bar to the that a cross section has been made that crosses the axis of rotation. The operator holds the end of the roll, commercial of FRP between both pieces, and rolls it around the already complete bar. When cutting the fiber, cutting means are used as industrial scissors, which eventually causes the FRP to degrade, eventually fraying.

The operator spreads epoxy resin on the surface to be treated, helped by a tool such as a brush. Then, the operator supports the bar on this surface and unwind, pressing with the bar itself until the FRP tape is fully adhered, after which it removes the bar, and passes a manual roller, limiting the pressure exerted on the tape to that determined by the surface of the roller and the force of the operator . The previous operations slow down the process considerably since several passes are necessary.

The application procedure using pre-impregnated FRP tape is similarly carried out by an operator. Among its disadvantages are that not only the inconvenience arising from the impregnation of said operator by the resin, but that these tapes should be kept in conditions that prevent the setting of the resin, for example by keeping the tapes pre-impregnated at temperatures above those of setting of the resin.

There is therefore a demand to automate the application of FRP tape minimizing material waste. When this process is automated, an option present in the state of the art comprises mounting the tool on a manipulation means that provides the ability to place and move said applicator, such as a robotic arm or the like (eg Kuka robots to place glass on ceilings: C. Han, Design of a Ceiling Glass Installation Robot, http://www.iaarc.org/external/isarc2007- cd / www / PDF / 2.4_5_076.pdf). Therefore, the greater the mass and dimensions of the tool, the greater the efforts and moments the parts of these handling means will have to support. Furthermore, the manipulation of this tool at a distance implies that the arm operator must be supplied with information to the arm based on the parameters such as the distance to the surface and the coating achieved. To allow the application of adhesive media, the surface must be devoid of contamination, such as those that use water or sand. In addition, the cracks and discontinuities on a surface of some construction elements, present as a result of the different processes after the setting of concrete, movements of heterogeneous lands and the like, make these surfaces present cracks and discontinuities that reduce the adhesion of the coating elements and especially the FRP strips. Therefore, it is desirable that a surface that reduces and more preferably, is lacking, be provided with these fissures and discontinuities. Typically these fissures have thicknesses between 2 and 20 mm, with lengths of up to 1 m, also presenting areas that apparently do not exceed a typical size of up to 10 mm but that hide cavities of much larger size than this. These latter structures are not well treated by those manual applications.

It is possible to minimize these problems by coating the surface, and especially the cracks present in the construction element by applying a means for preparation such as a resin. In the application of those FRP tapes that lack adhesive, it is necessary to dispense said adhesive (generally an epoxy resin or "epoxy" known in the state of the art for each FRP) before dispensing the tape. As the interval between the dispensing of the epoxy resin and the FRP tape increases, chemical adhesion degrades and the resin exposure to contaminants is increased.

A problem present in the state of the art is that related to the optimal application of the tape so that the adhesion is optimal is the corrugation of the tape applied on the surface that does not allow a uniform dispensing of the FRP tape, so that the Mechanical properties of the construction element-coating set are optimal. For this, the tool must be able to place a strip of FRP tape on a layer of a resin (usually epoxy type) previously deposited in a uniform way without applying on the tape tensions that eventually take off said tape, such as when the speed The displacement of the tool on the surface of the construction element is greater than the speed of dispensing of the belt. On the other hand, if the speed of movement of the tool on the surface of the construction element is much lower than that of the tape dispensing, folds are formed in the belt, of way that the coating has corrugations. These corrugations will be the ones that fold back if the weakened surface tries to expand. In addition, these corrugations contain regions (similar to bubbles) of air that degrade adhesion to the surface of the building element. If the tool were not able to provide a strip of tape (by cutting said tape) it would be necessary to cut the tape manually, which slows down the procedure and decreases the efficiency of applying a coating.

In addition, for use in an automated and remote way, the operator needs to receive information about both the position of the tool with respect to the surface of the construction element - as the coating has to dispense the tape following the surface of the construction element ( curvature, accidents, etc.) - as an inspection of the state of the same remotely avoiding impacts of the tool against the surface.

Therefore, it is necessary to provide a tool that allows the application of a coating on the surfaces of construction elements with FRP tape, comprising the dispensing of strips of FRP tape, embedded in an epoxy resin, which does not present undue corrugations in the coating, and without causing tensions that take off already glued tape, thus achieving a coated surface where the properties of the FRP tape and the surface of the structure are combined, thereby significantly improving the mechanical properties (eg elasticity) of the coating of said structure.

Description of the invention These and other problems are solved in the present invention by means of a tool that allows the preparation of the surface of a construction element for the dispensing, embedding and cutting of a strip of FRP of the non-pre-impregnated type of adhesive, of automatically and remotely according to independent claim 1. In addition, a method according to independent claim 14 for the remote and automated application of FRP tapes. Other aspects of the invention and particularly advantageous embodiments thereof are defined in the dependent claims.

In a first aspect, a tool can be connected to a manipulation means such as a robotic arm, made of aluminum, Nylon to minimize the stresses and moments exerted on the manipulation means (e.g. the joints of a robotic arm). This tool comprises a structure or frame for the application of this FRP tape. Among these elements there are storage means, such as a FRP tape roller, which supply a tape to a FRP tape dispensing means, such as guide rollers, which in turn comprises a set of cutting elements to provide strips. of FRP tape. It also comprises a driving means, preferably comprising a driving roller, mechanically connected by means of transmission to the FRP tape dispensing means as well as a compression means for embedding said tape in an adhesive, so that advantageously the movement provided by the handling means, moving the tool on the surface defining an application direction and a direction of travel, provides power transmitted to a FRP tape dispensing means adjusted so that the FRP tape dispensing speed is substantially similar to that of tool offset

The tool is preferably inscribed in a parallelepiped with dimensions of a width between 0.15 and 1.5 m, a length of 0.15 m and a height of 0.10 m. These dimensions allow the tool to also have greater maneuverability to allow automatic coating over a wide range of radii of curvature, especially those present in tunnel vaults. The tool does not present any autonomous driving means as motors for reduce the weight of it to a minimum. On the contrary, the drive means that guides the belt and allows to follow the curvature of the surface of the construction element and take advantage of the load provided by the handling means. For this purpose, it has a traction surface adapted to adhere to the surface of the construction element. Depending on the surface on which the driving means is moved, it is possible to select advantageously those materials for manufacturing the traction surface looking for an improvement in adhesion which allows to obtain better results in the application of the tape. Advantageously, the tool incorporates means for detachably attaching different traction surfaces to the driving means, so that different types of materials of the surfaces of the construction elements are capable of coating for the same characteristics of the manipulative means.

The tool uses transmission elements that allow a substantially 1: 1 ratio between the speed of dispensing of the belt and the advance of the tool as a gear set or a belt-pulley assembly, of dimensions adapted to compensate for the relative dimensions of the drive and dispensing rollers. Preferably by means of a set of pulleys and gears that connect the roller of the driving means or with the dispensing means. Particularly it lies between the roller of the driving medium and the roller of the dispensing medium compensated with a 1: 1 ratio.

The cooperation between the handling means, the driving means and the transmission means makes the speed of dispensing of the FRP belt substantially equal to the speed with which the tool travels on the surface to be coated of the construction element, avoiding tensions in the FRP tape and that when dispensing the FRP tape on the surface of the construction element it presents folds and gives rise to corrugations. Furthermore, the set of cutting elements of the dispensing means adapted to guide the belt from the storage medium, preferably by means of a set of rollers of the set of cutting or guide elements, which is in contact with the FRP tape and prevents its recoil so that it provides FRP tape after cutting the tape, which allows to provide strips of FRP tape automatically.

In addition, the tool has a compression means that allows the tape to be soaked and soaked with the epoxy resin that has previously spread over the surface. For this purpose, it has a compression means that, after dispensing the tape on the surface of the construction element, exerts a pressure, embedding the FRP tape in the adhesive medium, which permeates the fibers of the FRP tape. The tool has means adapted to channel a jet of a gas towards the surface, preferably, taking as a reference the direction of travel, oriented towards a region prior to the drive roller, preferably being pressurized air to perform surface cleaning processes of the element construction which simplifies the cleaning system compared to those that, such as sand or hydrodernolition, involve the presence of valves and deposits, causing fewer incidents with passers-by because it avoids the presence of liquids.

It also incorporates means for dispensing adhesives and resins for coating cracks and discontinuities on the surface to be coated. For this there is an area adapted to removably accommodate a resin dispenser in the tool that allows both to fill cracks, as well as to provide an adhesive in which to embed the strip of FRP tape. The resin dispenser is capable of being actuated to dispense resin, preferably remotely, it is oriented to dispense the epoxy resin in a posterior region the driving roller and prior to the dispensing roller in the direction of travel, thus allowing a dispensing of the epoxy prior to the dispensing of the FRP tape.

In addition, both to automate and to allow control of the tool it advantageously incorporates distance control means to the surface of the construction element with information on both the position of the tool relative to the surface of the construction element.

It also advantageously incorporates sensors such as telematic means for determining the distance to the surface of the tool such as optoelectronic means that allow the inspection of the state of the surface of the construction element remotely.

In a second aspect, a method for remote automatic coating by strip of FRP tapes is provided, comprising using the tool described in the first inventive aspect remotely, by means of manipulation, on the surface), curved or flat, of construction elements such as tunnel vaults according to claim 13 comprising a) providing a tool for the application of FRP tape as cited in the first inventive aspect b) moving the tool on the surface of the construction element c) driving the dispensing of resin of the resin dispensing medium d) remotely actuate the cutting means In an embodiment, the fissures of the surface of the construction element are coated in an earlier stage with an epoxy resin. This makes it possible to improve the adhesion of the FRP tape, and completed in another embodiment variant by cleaning the surface of the construction element by means of cleaning means and particularly by compressed air, which results in a better adhesion of the FRP tape. Brief Description Of The Figures

-Figure 1: Schematic plan view of one of the preferred embodiments of the invention.

-Figure 2: Schematic profile view of one of the preferred embodiments of the invention.

-Figure 3: Exploded schematic view of one of the preferred embodiments of the invention.

-Figure 4: Schematic perspective view of one of the preferred embodiments of the invention. -Figure 5: Schematic view of the transmission system of one of the preferred embodiments of the invention.

Description of particular embodiments of the invention

A preferred embodiment of the invention provides a tool (1) for the automatic application of FRP tape (12) and an epoxy adhesive, connectable to a handling means. In a variant embodiment, the handling means is a robotic arm (not shown) which can be connected to the invention preferably by means of a flange, providing the area adapted to connect with the connected handling means and its housing flange (19). for removable fixing means and particularly screw, screw / nut.

The tool is preferably inscribed in a parallelepiped with dimensions preferably of a width between 0.15 and 1.5 m, of a length of

0.15 m and a height of 0.10 m. The elements of the tool (1) are supported on a frame (15), preferably this frame (15).

In a variant embodiment, this frame (15) has an adapted area connect with the robotic arm and its flange (19 by means of a series of housings of removable fixing means, preferably screws. On the opposite side of said adapted zone connect with the robotic arm and its flange (19) there is a driving roller (5 ), which protrudes from the frame (15), and provides traction when an arm moves the tool over the surface to be coated (20). The drive roller (5) engages at a first end of the frame (15), so which in a variant embodiment is the only means of contact of the tool with the construction surface.

Preferably the drive roller (5) has a diameter of 0.05 m, and more preferably has a width of 0.15 m.

The traction of this drive roller (5) also depends on the adhesion of the material that covers it. Preferably this roller comprises parts made of deformable materials such as a rubber (Young's Module ~ 0.01-0.1 GPa). In an even more preferred embodiment the traction surface, i.e. which part of the drive roller (5) in contact with the surface to be coated, is made of materials that allow to increase the adhesion to the chosen surface depending on the surface on which the tool (1) moves, and include rubber finishes , tack or silicone or any medium that suits the required traction. It has been found that the sandpaper provides excellent qualities for this application, as well as those o-rings with finishes such as shot blasting, or the like. More preferably, not only the surface of the drive roller (5) but the drive roller (5) are made of these materials.

In a preferred embodiment these materials can be fixed to the traction surface of the roller by separable joining means. In an even more preferred embodiment these means use sailboat (R) to attach these coatings detachably to the drive roller (5) allowing faster exchange and replacement.

The FRP tape strip dispensing means comprises a roller of tape dispensing (3) and a set of cutting elements (6). The set of cutting elements in turn comprises a set of guide rollers (6a-6b) or guide rollers to facilitate dispensing of the tape after cutting located next to a cutting element (7). The number of rollers in this roller assembly is preferably four guide rollers (6a-6d). The cutting element (7) is preferably a blade. A drive means allows to act remotely on the cutting element (7). Preferably this drive means is a set of linear actuators, and more preferably pneumatic mini-cylinders (23).

In addition, the tape strip dispensing means has a support (9) for storing the FRP tape in the tool (1). Preferably, this support is a roll. The tape is introduced into the set of cutting elements (6) and from there it goes to the dispensing roller (3). The dispensing roller protrudes from the frame (15) in the same direction as the drive roller (5) and is next to the drive roller (5) in the direction of travel. Transmission means, preferably a belt assembly (1 1a) - pulley (25a, 25b) transmits the movement of the roller of the dispensing roller (3) to the driving roller (5). In a variant embodiment, a first pulley (25a) is attached to the drive roller (5) and a second pulley (25b) is attached to the dispensing roller (5).

For this, the size of the pulleys (25a, b) is adjusted so that it compensates for a difference in the diameter of the rollers (5, 3). Particularly, these transmission means are adapted so that the dispensing speed of FRP belt (12) is substantially equal to the speed of advance of the tool so that the ratio between the radius of the first and second pulley is inverse to the ratio between the drive roller (5) and the radius of the dispensing roller (3). Preferably the adjustment of the belt tension (11a) is carried out by at least one tensioner (21). Preferably at least one of the two lower guide rollers (6a, 6b) are in turn connected by means of transmission to the dispensing roller (3). Preferably by a third pulley (25c) and a drive belt (11 b) to the second pulley (25b) of the dispensing roller (3). Even more preferably, the guide rollers (6a, 6b) next to the cutting element are in contact with the same belt (11a) that goes from the dispensing roller (3) to the drive roller (5). In turn, the pulley (25c) of these rollers is adapted to compensate for the size of the pulleys (25) so that it compensates for a difference in the diameter of the rollers (6a, 6b, 3). Preferably the ratio between the diameters of the drive roller (5) and the guide rollers (6a, 6b) is 1: 3 and that of the third pulley (25c) and the second pulley (25b) is 3: 1.

In a preferred embodiment, a second tensioner (14) is used between the dispensing roller (3) and the guide rollers (6a, 6b) to adjust the tension in the belt (1 1 b) and improve power transmission.

In another variant embodiment, the cutting means (6) of the tool preferably comprise a guillotine-shaped blade (22) in contact with the actuator assembly (23) which allows cutting the strip of FRP tape (12). Even more preferably, the blade (22) is mounted on a blade holder (24), attached to the actuators (23). The set of four rollers and the blade (6) cooperate so that, after the cut made by the blade, tape is still dispensed. It is the driving roller (5) who drives the guide and dispensing rollers (3, 6a, 6b) through the transmission means.

In addition, a roller (2), located next to the dispensing roller (3) in the direction of travel and joined by an elastic means such as a spring (10) that compresses the FRP tape (12) against the surface. Preferably the tool (1) shows that it comprises an area adapted to removably accommodate a resin dispensing means (8) comprising a resin resin dispensing means (17) as a cartridge. When a resin intended to fill cracks is loaded, it can advantageously incorporate a projection (18) that allows the injection of the resin at higher pressure, allowing the cracks and cavities present in the substrate to be filled, obtaining a continuous surface that allows subsequently applying epoxy resin of uniform shape This improves the mechanical properties of the assembly comprising a construction element and the FRP belt (12). In another variant embodiment, the resin application nozzle is oriented behind the tractor roller and in a direction towards the surface (20) contrary to the direction of application of the tool. Thus, the resin is dispensed without affecting the friction of the coating of the tractor roller with the surface (20) and ensures the necessary motor for the application of the FRP belt. In a variant embodiment, the resin dispensing means (17) has a resin outlet located between the drive roller (5) and the dispensing roller (3), which allows traction of the drive roller when rolling on the clean surface . Preferably these resin dispensing means (17) are preferably adapted to dispense epoxy resin using means of injecting a compressed gas (not shown).

In another variant embodiment, the tool (1) has a projection (13), preferably rectangular, to act as a spatula during pressing the FRP tape (12) collecting the oozing resin, located between the dispensing roller (3) and the presser roller (2).

In one embodiment the tool (1) comprises telematic means as distance telemetry means. Particularly, the tool (1) comprises an image acquisition means (16), preferably a digital camera, and even more preferably wireless. This means of image acquisition is oriented to collect the image in the direction of advance of the tool (1). In a preferred embodiment it is located at one end of the frame (15). These means allow to inspect and direct the preparation and dispensing work remotely, which allows an inspection of the different stages of the coating.

In another variant embodiment, the tool incorporates a support for housing a means for cleaning the surface, located before the drive roller (5) in the direction of travel. It is preferably a compressed air dispensing means, which allows a surface to obtain a clean surface (20) with minimal weight gain.

Preferably the pieces of this structure are made of nylon or aluminum. In a variant embodiment, the tool parts (1) are made of a lightweight material such as titanium. These materials allow better manipulation by the robotic arm.

A method is also provided for automatic coating by strip of FRP tapes (12), of the non-impregnated type of adhesive, and an epoxy adhesive on curved or flat surfaces (20) of construction elements such as tunnel vaults that it comprises a) providing a tool (1) according to any of the embodiments, connected to the handling means; b) move the tool (1) on the surface (20) of the construction element c) actuate the resin dispensing of the resin dispensing means (8) d) remotely actuate the cutting means (6 '). In a variant embodiment, the fissures of the surface (20) of the construction element are coated in an earlier stage with an epoxy resin. This allows to improve the adhesion of the FRP tape (20). In a variant embodiment, the surface (20) of the construction element is cleaned by means of cleaning and particularly by compressed air, which results in a better adhesion of the FRP tape (20).

Claims

1. Tool (1) connectable to a means of manipulation for the automatic remote application of FRP tape (12), of the type not impregnated with adhesive, and an epoxy adhesive on surfaces (20), curved or flat, of construction elements such as tunnel vaults characterized by comprising

- a pressing roller (2);

- a driving means comprising a driving roller (5);

- a power transmission medium;

- a resin dispensing means (8);

- a means of dispensing FRP strips which in turn comprises

or a dispensing roller (3);

or a cutting means (6 ');

or at least two guide rollers (6a, 6b); Y

- a FRP tape storage medium (9);

wherein the dispensing roller (3) and the driving roller (5) are connected by means of the power transmission means with dimensions adapted to provide a transmission ratio such that the dispensing speed of FRP tape (12) substantially similar to the forward speed when moving the tool (1) on the surfaces (20).

2. Tool (1) according to claim 1 wherein the power transmission means comprises at least a first pulley (25a), a second pulley (25b) and a belt (1a), wherein

the first pulley (25 a) is attached to the drive roller (5) and the second pulley (25b) is attached to the dispensing roller (3), keeping the diameters of the first and second pulley (25a, 25b) an inverse relationship to the relationship of diameters between the drive roller (5) and the dispensing roller (3),

and particularly a 1: 1 ratio.

3. Tool (1) according to claim 2 comprising a third pulley (25c) and a second belt (11b) attached to at least one guide roller (6a),

keeping a relationship between the diameters of said third pulley (25c) and the second pulley (25b) an inverse relationship to the relationship of diameters between the dispensing roller (3) and the at least one guide roller (6a), and particularly a ratio between the diameters of said third pulley (25c) and the second pulley (25b) of 3: 1.

4. Tool (1) according to any one of claims 1 to 3 wherein the drive roller (5) is made of or coated with rubber, tack or silicone, sandpaper, particularly o-rings with shot blasting finishes.

5. Tool (1) according to claim 4 wherein the surface coating of the drive roller (5) is detachably attached to the drive cylinder (5), and more particularly by sailboat (R).

6. Tool (1) according to any one of claims 1 to 5 comprising a blade holder (24) and a set of actuators (23), particularly pneumatic micro-actuators.

7. Tool (1) according to any of claims 1 to 6 comprising a projection (13) between the dispensing roller (18) located between the dispensing roller (3) and the pressing roller (2).

8. Tool (1) according to any one of claims 1 to 7 comprising an area adapted to receive surface cleaning means (20), in particular for housing a compressed air dispensing means.

9. Tool (1) according to any of claims 1 to 8 comprising an area adapted to connect with the connected handling means and its flange (19) housing removable fixing means, and particularly screw, screw / nut.

10. Tool (1) according to any one of claims 1 to 9 which is inscribed in a parallelepiped of dimensions; width from 0.15 to 1.5 m; height of 0.10 m; length of 0.15 m, and in particular of width 0.15 m.

11. Tool (1) according to any of claims 1 to 10 comprising a telematic means for determining the distance to the surface (20) of the tool (1), particularly a wireless image acquisition means.

12. Tool (1) according to any of claims 1 to 10 wherein the parts of the tools are made of aluminum and / or nylon.

13. Tool (1) according to any of claims 1 to 10 wherein the resin application nozzle is oriented behind the tractor roller and in a direction towards the surface (20) contrary to the direction of application of the tool.

14. Method for automatic and remote coating by strip of FRP tapes (12), of the type not impregnated with adhesive, and an epoxy adhesive on surfaces (20), curved or flat, of construction elements such as tunnel vaults characterized because he understands

a) providing a tool (1) according to any one of claims 1 to 12 in connection with a handling means;

b) move the tool (1) on the surface (20) of the construction element;

c) actuate the resin dispensing of the resin dispensing medium (8)

d) remote activation of the cutting means (6 ') of the tool.

15. Method for automatic coating by strip of FRP tapes (12), according to claim 13 further comprising

apply at a previous stage a coating of the surface (20) of the construction elements by means of an epoxy resin.

16 ". Method for automatic coating by strip of FRP tapes (12), according to claim 13 further comprising

in a previous stage, clean the surface (20) of the construction element by means of the compressed air dispensing means.