Description

FRAME STRUCTURE FOR CONSTRUCTING A VESSEL MADE

OF COMPOSITE MATERIAL AND A MANUFACTURING

METHOD OF THE FRAME STRUCTURE

Technical Field

[1] The present invention relates to a mold structure for constructing a ship formed of composite materials and a method for manufacturing the same, and more particularly, to a mold structure for constructing a ship formed of composite materials wherein the mold structure is made by using heat shrinkable fabrics or films and square or round steel pipes, unlike a fixed wood mold made of hard materials like wood fiber reinforced plastics (FRP) veneer sheets, plywood and the like in conventional ships formed of composite materials, and to a method for manufacturing the same. Background Art

[2] The FRP as one of representative composite materials, which is composed of unsaturated polyester resin and glass fibers, is stronger than steel and lighter than aluminum in physical properties. The glass fiber reinforced plastics is excellent in abrasion, heat and weather resistant properties and moldability, such that it is widely used in ship's construction. As the molding technology of the FRP is rapidly developed to obtain the improvement of strength, recently, the FRP is widely used in automobiles, aircrafts, trains and general industrial products.

[3] In spite of the development of the molding technology of the FRP, however, a wood mold for constructing middle or big-sized products or a small number of custom-made structures should be made in a manual-operating manner. Further, the mold structure for constructing the ship is made by using a CNC (computer numerical control) machine and multi- articulated robots in developed countries, thereby needing enormous equipment costs, which unavoidably causes high manufacturing costs.

[4] Referring to a method for making a wood mold for constructing the ship formed of

FRP, the wood mold is made of plywood, veneer sheets, square lumber, nails, FRP sheets and so on in a manual-operating manner or by means of the CNC machine and the multi- articulated robots, to have the same shape as a product to be made.

[5] That is, a first process in the conventional method for manufacturing the mold for constructing the ship formed of composite materials comprises the steps of making the wood mold made of plywood, veneer sheets, square lumber, nails, FRP sheets or other hard materials in a manual-operating manner, filling a filler (putty) in gaps, curves and concave/convex portions formed on the connection portions between the materials, and smoothly polishing the entire surfaces of the wood mold.

[6] Next, a second process thereof comprises the steps of conducting surface treatment

(formation of surface film and brightening of the surfaces of the wood mold) and applying a mold release agent (stripper) on the surfaces thereof, thereby finishing the manufacturing method for the wood mold for constructing the ship formed of FRP.

[7] In case where the CNC machine and the multi-articulated robots are adopted, the blocks made of raw and processed materials like plaster and wood having excellent workability are needed to correspond to the size of the wood mold, which is possible in making a small-sized product, but is not difficult to make a middle or large-sized product. Besides, a relatively long surface treatment time period and high personnel costs in the same manner as in the existing wood molds are needed until the blocks are used as the wood mold after the processing.

[8] Hence, the existing wood mold-making method and the mold-making method using the CNC machine and the multi- articulated robots have the defects in that the material costs, the personnel costs, the installation costs are raised to cause the product costs to be substantially high.

[9] Additionally, the disposal of the existing wood mold undesirably causes industrial pollution.

[10] As one of the prior art, there is disclosed Korean Patent No.0419363 (entitled

'Simple mold for FRP molding') wherein in case of a small number of products having the same shapes, high costs are needed to make the mold for molding the product, and thus, moldless construction technique is introduced.

[11] In case where a large number of products having the same shapes are made, however, there is a need for the development of the mold resistant well to the heat generated during the product molding, external impacts and load.

[12] In case of ships, especially, a sample is first made to satisfy the performance needed on the design and other conditions, and also, a complete product shape is determined through lots of performance tests. In the conventional method for manufacturing a wood mold the formation of the sample needs much material costs, high personnel costs and long construction period of time. Further, if the wood mold is made according to the conventional method, the costs corresponding to two to three times of the production costs of the molded product are needed. In addition, the hard wood sheets having restricted sizes are formed to be flat or curved by fixing the outer edge structures (pipes) of the wood mold by means of screw nails, rivets and bolts, and in this case, so as to support the stress of the wood sheets, the fixing parts should be strong and needed in large numbers. Also, so as to fill the connection portion between the sheets having the restricted sizes and to conduct the surface treatment for the marks formed by the screws and fixing parts, lots of skilled manual operations should be required.

[13] Moreover, since all constituting surfaces and materials of the mold are made of wood sheets, the mold needs a large number of materials so as to support its own weight and a mold product's weight. Disclosure of Invention

Technical Problem

[14] Accordingly, the present invention has been made to solve these problems, and it is an object of the present invention to provide a mold structure for constructing a ship formed of composite materials and a method for manufacturing the same, wherein the contour of the mold is formed of substantially strong steel structures like square or round pipes having gentle straight lines or curves so as to have the characteristics of solidity, linearity and continuousness and the constituting surfaces of the ship are formed of heat shrinkable fabrics or films, thereby providing beautiful constituting surfaces and contour lines, and wherein the raw material costs, the personnel costs and the construction period are all reduced. Technical Solution

[15] To achieve the above object, in one aspect, the present invention provides a mold structure for constructing a ship formed of composite materials, the mold structure comprising a female mold support part and a male mold support part for making the mold for constructing the ship formed of composite materials, and a female mold part and a male mold part for making the ship formed of composite materials, the female mold part being formed inside the female mold support part and including a female bulwark top line, a female chine line, a female keel line, female frames, female pipes and a female flexible material, and the male mold part being formed outside the male mold support part and including a male bulwark top line, a male chine line, a male keel line, male frames, male pipes and a male flexible material, wherein the female flexible material of the female mold part and the male flexible material of the male mold part are fixedly bonded to the female pipes and the male pipes by means of an adhesive.

[16] According to the present invention, the female and male flexible materials are formed of a heat shrinkable fabric or film, wherein the heat shrinkable fabric is made of a polyester fabric and the heat shrinkable film is made of a polyvinyl chloride PVC, polyethylene PE or polypropylene PP film.

[17] In another aspect, the present invention provides a method for manufacturing a mold structure for constructing a ship formed of composite materials including the steps of: manufacturing a female mold support part and a male mold support part to conform to the shape of the ship to be constructed on bottom support frames having the same plane shape as that of the ship to be constructed; installing a plurality of pipes on the female mold support part and the male mold support part so as to take the contour

of the ship having planes and curves; fixing a plurality of female and male frames so as to take the shape of the ship; attaching female and male flexible materials by means of an adhesive onto female and male bulwark top lines, female and male chine lines, female and male keel lines, the female and male frames, female and male stern plates formed on the contour of the ship; heating the female and male flexible materials so as to allow the female and male flexible materials to be expanded; and applying paint or a glazing agent made of epoxy or urethane onto the expanded female and male flexible materials and releasing the mold for constructing the ship formed of composite materials. Brief Description of the Drawings

[18] FIG.1 is a perspective view showing a female mold part in a mold structure for constructing a ship formed of composite materials according to the present invention that is made by using heat shrinkable fabrics or films and square or round steel pipes.

[19] FIG.2 is a perspective view showing a male mold part in the mold for constructing a ship formed of composite materials according to the present invention that is made by using heat shrinkable fabrics or films and square or round steel pipes.

[20] FIG.3 is a sectional perspective view showing the female mold part formed by coupling the respective structures to the heat shrinkable fabrics or films according to the present invention.

[21] FIG.4 is a sectional view showing the female mold part formed by coupling the respective structures to the heat shrinkable fabrics or films.

[22] FIG.5 is a sectional perspective view showing the male mold part formed by coupling the respective structures to the heat shrinkable fabrics or films.

[23] FIG.6 is a sectional view showing the male mold part formed by coupling the respective structures to the heat shrinkable fabrics or films.

[24] FIG. 7 is a flowchart showing the processes for manufacturing a mold structure for constructing a ship formed of composite materials. Mode for the Invention

[25] Hereinafter, an explanation on a mold structure for constructing a ship formed of composite materials according to a preferred embodiment of the present invention will be given with reference to the attached drawings.

[26] FIG.1 is a perspective view showing a female mold part in a mold structure for constructing a ship formed of composite materials according to the present invention that is made by using heat shrinkable fabrics or films and square or round steel pipes, FIG.2 is a perspective view showing a male mold part in the mold for constructing a ship formed of composite materials according to the present invention that is made by using heat shrinkable fabrics or films and square or round steel pipes, FIG.3 is a sectional

perspective view showing the female mold part formed by coupling the respective structures to the heat shrinkable fabrics or films according to the present invention, FIG.4 is a sectional view showing the female mold part formed by coupling the respective structures to the heat shrinkable fabrics or films, FIG.5 is a sectional perspective view showing the male mold part formed by coupling the respective structures to the heat shrinkable fabrics or films, FIG.6 is a sectional view showing the male mold part formed by coupling the respective structures to the heat shrinkable fabrics or films, and FIG. 7 is a flowchart showing the processes for manufacturing a mold structure for constructing a ship formed of composite materials.

[27] A mold structure for constructing a ship formed of composite materials according to the present invention is configured by using heat shrinkable fabrics or films and square or round steel pipes as shown in FIGS.l to 6, and first, an explanation on a female mold part will be given.

[28] FIGS. 1, 3 and 4 show the female mold part in the mold for constructing a ship formed of composite materials, wherein the five constituting surfaces, that is, a female left-hand bottom frame 12 and a female right-hand bottom frame 12-1, a female port frame 11 and a female starboard frame 11-1 fixed symmetrically at the both top ends of a female bottom support frame 14, and a female stern plate 15, which are formed by a plurality of lines, that is, a female bulwark top line 21, a female chine line 22 and a female keel line 23, are coupled individually or all together to a female flexible material 26 formed of a heat shrinkable fabric or film. In more detail, a female mold support part 10 is configured wherein the female bottom support frame 14 has the same plane shape as that of the ship to be constructed and the female port frame 11 and the female starboard frame 11-1 are slantly fixed symmetrically at the both top ends of the female bottom support frame 14. Next, a female vertical support 13 fixedly erects on the top end of the center portion of the female bottom support frame 14, and the female left-hand bottom frame 12 and the female right-hand bottom frame 12-1 face each other to have a 'V- like shape over the female bottom support frame 14. Then, the female left-hand bottom frame 12 and the female right-hand bottom frame 12-1 are fixed at the both side surfaces to the female port frame 11 and the female starboard frame 11-1.

[29] A female mold part 20 is configured wherein a plurality of female frames 24 are horizontally spaced apart from each other by a given distance on the female port frame 11, the female starboard frame 11-1, the female left-hand bottom frame 12 and the female right-hand bottom frame 12-1 disposed inside the female mold support part 10, and a plurality of first and second female pipes 25 and 25-1 are mounted on the plurality of female frames 24 in such a manner that a given gap is formed between the first female pipe 25 and the second female pipe 25-1 so as to insert two sheets of

female flexible materials 26 thereinto and after the first female pipes 25 and the second female pipes 25-1 are fixed on the plurality of female frames 24, the female flexible material 26 is bonded to the first female pipes 25 and the second female pipes 25-1 by means of an adhesive 50. Next, the female flexible materials 26 are heated and expanded, and after the expansion, they are painted and glazed with paint and a glazing agent.

[30] FIGS. 2, 5 and 6 show the male mold part in the mold for constructing a ship formed of composite materials, wherein the five constituting surfaces, that is, a male left-hand bottom frame 32 and a male right-hand bottom frame 32-1, a male port frame 31 and a male starboard frame 31-1 fixed symmetrically at the both top ends of a male bottom support frame 34, and a male stern plate 35, which are formed by a plurality of lines, that is, a male bulwark top line 41, a male chine line 42 and a male keel line 43, are coupled individually or all together to a male flexible material 46 formed of a heat shrinkable fabric or film. In more detail, a male mold support part 30 is configured wherein the male bottom support frame 34 has the same plane shape as that of the ship to be constructed and the male port frame 31 and the male starboard frame 31-1 are slantly fixed symmetrically at the both top ends of the male bottom support frame 34. Next, the male left-hand bottom frame 32 and the male right-hand bottom frame 32-1 face each other to have a 'λ'- like shape on the both top ends of the male port frame 31 and the male starboard frame 31-1. Then, the male left-hand bottom frame 32 and the male right-hand bottom frame 32- 1 are fixed at the undersides of the both ends to the male port frame 31 and the male starboard frame 31-1.

[31] A male mold part 40 is configured wherein a plurality of male frames 44 are horizontally spaced apart from each other by a given distance on the male port frame 31, the male starboard frame 31-1, the male left-hand bottom frame 32 and the male right- hand bottom frame 32- 1 disposed inside the male mold support part 30, and a plurality of male pipes 45 are mounted vertically on the plurality of male frames 44 to the shape of the ship and fixed by means of welding. Next, the male flexible material 46 is bonded to the male pipes 45.

[32] The female flexible material 26 and the male flexible material 46 are formed of the heat shrinkable fabric or film, such that as they have appropriate flexibility to provide free curved surfaces, and they are contracted again if heat is applied to them, thereby improving the utilization thereof.

[33] In this case, the heat shrinkable fabric used as the female flexible material 26 and the male flexible material 46 is desirably made of a polyester fabric, and the heat shrinkable film is desirably made of any one selected from polyethylene PE, polypropylene PP and polyvinyl chloride PVC, which allows the lines and surfaces to be easily formed. Further, since the female flexible material 26 and the male flexible

material 46 have the properties of continuousness and flexibility, it is easy to couple them on the respective pipes.

[34] Now, an explanation on a process of manufacturing the mold for constructing a ship formed of composite materials will be in detail given, wherein the heat shrinkable fabric or film and the square or round steel pipes are used in making the mold.

[35] According to a method for manufacturing the mold for constructing a ship formed of composite materials wherein the mold is formed by using the heat shrinkable fabrics or films and the square or round steel pipes, first, at a step SlO of making the mold, the female mold support part 10 is made on the female bottom support frame 14 having the same plane shape as that of the ship to be constructed so as to have the shape of the ship to be constructed, and next, the male mold support part 30 is made on the male bottom support frame 34 having the same plane shape as that of the ship to be constructed so as to have the shape of the ship to be constructed.

[36] At a step S20 of installing the plurality of pipes, next, the plurality of pipes 24 and

45 are located on the female mold support part 10 and the male mold support part 30 made at the step SlO so as to form the five flat and curved surfaces, that is, the female and male port frames 11 and 31, the female and male starboard frames 11-1 and 31-1, the female and male left-hand bottom frames 12 and 32, the female and male right- hand bottom frames 12-1 and 32-1, and the female and male stern plates 15 and 35 constituting the contour of the ship.

[37] At a step S30 of fixing the plurality of frames, next, after the contour of the ship has been made by using the square or round steel pipes 25 and 45 the plurality of female frames 24 and male frames 44 are fixed by means of welding and bolts so as to take the solid contour of the ship.

[38] At a step S40 of bonding the flexible materials, then, the female and male flexible materials 26 and 46 formed of the heat shrinkable fabric or film are bonded by means of an adhesive 50 to the female and male port frames 11 and 31, the female and male starboard frames 11-1 and 31-1, the female and male left-hand bottom frames 12 and 32, the female and male right-hand bottom frames 12-1 and 32-1, the female and male bulwark top lines 21 and 41 produced by the female and male stern plates 15 and 35, the female and male chine lines 22 and 42, the female and male keel lines 23 and 43, the female and male frames 24 and 44 and the female and male stern plates 15 and 35 constituting the contour of the ship formed by the step S20 of installing the pipes.

[39] At a step S50 of heating the flexible materials, next, the female and male flexible materials 26 and 46 bonded at the step S30 of bonding the flexible materials are heated so that they are contracted according to the features of the heat shrinkable fabric or film to provide tension adequate to construct the ship formed of composite materials, and after heating, they are painted and released.

[40] At a step S60 of releasing the mold, an epoxy and urethane-based paint and glazing agent are applied on the female and male flexible materials 26 and 4 expanded at the step S50 of heating the flexible materials, and then, the mold is released to prepare the mold for constructing the ship formed of composite materials.

[41] The mold releasing is the same as in existing wood molds, and if compressed air and water are put between the product and the mold at the time of mold releasing, the mold according to the present invention can be reused two or three times.

[42] On the other hand, if heat is applied to the heat shrinkable fabric removed after the use, the fabric can be contracted again, and therefore, it can be recycled when a relatively small-sized mold is made, thereby increasing the recycling efficiency of the material.

[43] Since each of the constitution surfaces of the mold is formed of one piece of fabric or film, no additional surface treatment process is needed on the connecting or coupling portions thereof. If necessary, the heat shrinkable fabrics or films used as the female and male flexible materials 26 and 46 are connected to one another by sewing so as to conform to the size of the constitution surfaces. Further, the sewing has very minute marks, such that no surface treatment is required, and since the constitution surfaces of the contour of the mold are coupled to the heat shrinkable fabric and film by means of the adhesive 50, no surface treatment is needed.

[44] According to the above-mentioned method, a high quality of product can be made at the expense of minimum material costs and personnel costs, and further, the need for the variation of the mold can be easily accepted. That is, as just the materials (fabric or film) for the constitution surfaces are needed to support only the weight of the product, they are negligible in load. If the product to be molded is large in number and has no need to change, the ship formed of composite materials, that is, FRP composite materials is molded just by means of the male mold part 40 as the male mold.

[45] While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention. Industrial Applicability

[46] As described above, according to the present invention, there is provided a mold structure for constructing a ship formed of composite materials and a method for manufacturing the same, wherein the free planes and curves constituting the contour of the mold are formed of heat shrinkable fabrics or films and square or round steel pipes, without any fill-inserting and polishing processes for the wood mold in the existing

practice, wherein after making the mold only a surface treatment is needed (which is just reduced by 1/10 when compared with the existing process), wherein the mold is made with beautiful lines and surfaces to provide excellent effects in the construction of high quality of ships, wherein the material costs, the personnel costs and the manufacturing time are all reduced and other linear transformation is easily obtained, and wherein the steel pipes are recycled, without having any disposal costs.