WO1994006675A1

WO1994006675A1 - Method of manufacturing a boat hull, and boat hull thus obtained

Info

Publication number: WO1994006675A1
Application number: PCT/FR1993/000896
Authority: WO
Inventors: Gérard RONZATTI
Original assignee: Etinter
Priority date: 1992-09-16
Filing date: 1993-09-16
Publication date: 1994-03-31
Also published as: FR2695617A1; FR2695617B1

Abstract

A method of manufacturing a flat-bottomed boat hull is described. A basic hull shape is prepared from a predetermined number of flat external wall elements (10, 14, 15, 17, 18, 21) and a hull is produced with the desired properties for a specific application by varying the size and shape of the flat wall elements. Application in boat building.

Description

manufacture of a boat hull and boat thus obtained ".

The invention relates to a method of manufacturing a hull of a boat and a boat hull thus obtained.

Until now, the manufacturers of boat hulls have endeavored to establish the shape of the hull first, according to the conditions of use, so that it is optimal from the hydrodynamic point of view, with the aim of minimizing the operating costs of the boat, such as for example its energy consumption necessary for its propulsion. This search for the hydrodynamic form, the most efficient, leads to hull forms characterized by curved external walls.

However, the construction of such hulls, especially when it is large hulls provided with a stiffening structure with transverse and longitudinal members is very expensive. Thus the economy achievable during the use of the boat has, as a counterpart, considerable manufacturing costs. On the other hand, already the design of the hull is very difficult and is therefore of high cost. Indeed, due to the very large number of variable parameters that must be taken into account for the design of the shell, the search for the optimal shape is very complex and time-consuming.

The object of the present invention is to propose a method which facilitates the design of the shell and makes it feasible at a relatively low cost.

To achieve this goal, a basic shell shape is established, consisting of a predetermined number of planar exterior wall elements and a shell is produced having desired properties for a specific use case, by varying the dimensions and shapes of planar wall elements.

According to an advantageous characteristic of the invention, the base shell is of the flat bottom type and comprises, as wall elements, an element forming the flat bottom, four oblique bottom elements comprising two front elements and two rear elements, two elements parallel side planking, two front plating elements and two rear plating elements.

According to another advantageous characteristic of the invention, the shape of the basic shell is defined using a computer program, comprising a reduced number of variable parameters as a function of the small number of elements.

LEAF OF RΞiw.? LAC_Ξ-v.Ξ T plans and ensures the search for the hull shape of a boat 'to be carried out by modifications of at least some of these variables.

According to another advantageous characteristic of the invention for the manufacture of a hull of a boat of the type whose deck and wall are assembled using stiffening members, planar wall elements are cut, after having determined their shapes and dimensions by modulating the elements of the base shell, in flat sheet metal panels, fixed on these planar elements, in the flat state, frame elements by advantageously automatic welding and constructed the shell by assembling the parts bottom and sides thus prefabricated.

A boat hull according to the invention, obtained by the implementation of the method as defined above, having a stiffening structure of the hull with members in particular transverse, fixed on the internal faces of the wall elements, is characterized in that these wall elements are planar elements and that the members fixed on the internal face of each wall element have been fixed on this element by advantageously automatic welding before the assembly of the various wall elements.

The present invention aims to provide a method of manufacturing a hull of a boat, which does not have the aforementioned drawback of the prior art.

To achieve this object, the method according to the invention is characterized in that the shell is produced by assembling flat sheet metal elements which constitute the bottom walls and sides of the shell, these elements are fixed plan, flat, of the frame elements by advantageously automatic welding and builds the hull by assembling the bottom and side pieces thus prefabricated.

The invention will be better understood and other objects, characteristics, details and advantages thereof will appear more clearly during the explanatory description which follows, made with reference to the appended schematic drawings given solely by way of example illustrating a mode of the invention and in which: Figure 1 is a schematic perspective view of a known method for manufacturing a hull of a boat.

Figure 2 is a schematic representation, similar to Figure 1, of the method of making a boat hull according to the present invention.

Figure 3 is a top view, partially exploded, of a boat hull according to the invention, the deck having been removed.

FIG. 4 is a bottom view of the boat hull according to FIG. 3.

FIG. 5 is a bottom perspective view of an improved boat hull similar to that of FIG. 4.

FIG. 6 is an elevation view of the boat hull according to FIG. 4.

Figures 7a, b to 9a, b are schematic views of different shell shapes according to the state of the art (in a) and the invention (in b), to demonstrate the advantages of the invention.

Figures 10a, b and 11a, b are views demonstrating advantages of the invention (in b) compared to the state of the art (in a).

FIG. 12 is a cutaway view along the line XII-XII of FIG. 5.

FIG. 13 shows in â the shape of a basic shell and in h to d three shapes of hulls obtained by modulation of this shape and intended for different uses.

Figure 1 is a schematic view of a hull of a boat of traditional shape, produced according to a specific process of the prior art. This figure shows in 1 the curved members which are fixed on the deck 2, which is the only plane element of the boat, and the sheet metal parts 3 which make up the sides of the boat and are assembled on the curved members. This assembly which is done by welding requires the application of continuous weld beads over the entire length of each of the members 1 the lonε misaligned contact of sheet metal parts with these members. Welding must be done by hand. Given the. large number of members and the considerable length of the weld beads, it is easy to understand that the process shown in FIG. 1, from the state of the art, is extremely expensive in terms of labor and makes the manufacture of boats very expensive.

FIG. 2 schematically illustrates the principle of the method for constructing a boat hull according to the present invention. This shell has a particular shape obtained by assembling pieces of flat sheet metal. As shown in Figure 2 in the example of part 5, member elements 6 are fixed flat on the sheet metal part 5. Since the fixing is done flat on the part 5, it can be carried out by industrial automatic welding. The only weld beads to be made by hand relate to the assembly of the prefabricated shell wall parts along the lines indicated in bold lines and marked with the reference 7. The arrows indicate the mounting of part 5 for the constitution of the shell where it is indicated by the reference 5 '.

Figures 3 to 6 show the embodiment of the shape of a boat hull obtained by applying the method according to the invention, illustrated schematically in Figure 2. Figure 3 first shows a flat part 10 intended to constitute the wall bottom of the hull. The references 1 1 and 12 indicate transverse member elements and longitudinal stiffening elements which are welded flat, automatically, on the bottom part 10. FIG. 3 also shows eight pieces of flat sheet metal intended to constitute elements of the side wall of the hull. On each of the parts bearing the references 14 to 21 are mounted, separately and in the flat state, the transverse member elements 23 and longitudinal stiffener elements 24 always by industrial automatic welding. After the prefabrication of various side wall elements, these are assembled on the bottom piece 10 and between them, in the manner symbolized by arrowed lines. The upper part of Figure 3 shows these different wall elements after assembly.

As can be seen in Figures 4 to 6 which show the hull of the boat when assembled, it has a very hydrodynamic particular shape, the outer surface of which has only flat surface elements, without any curving. It is obvious that the shape of the hull is variable and easily adaptable to the requirements, for example determined by the application or the purpose for which the boat is to serve. For this purpose, it suffices to cut the shape of the flat parts accordingly and to choose the number of such parts. As can easily be understood by looking at FIG. 3, the cutting which is made flat of the different sheet metal parts presents no problem and could be carried out according to a computer-assisted process. The mounting on these parts of the members also presents no problem.

Referring to FIGS. 7 to 11, the major advantages which the process for manufacturing a boat hull according to the invention provides will be described below.

Figure 7a shows a boat hull of the type of most river touring boats designed on the model of a barge. Their hull is a parallelepiped whose front end consists of hubcaps which meet to give the front of the boat its hydrodynamic shape. FIG. 7b shows the shape of the hull with a considerably improved prismatic coefficient which can be achieved by applying the method according to the invention, at a price comparable to that of the boat according to FIG. 7a. This improved prismatic coefficient of the hull according to the invention consequently results in fuel economy and an improvement in the speed of the boat.

FIG. 8a shows a boat of which the part 25 submerged in water is very large and extends over practically the entire length of the boat. This part 25 characterizes the hulls of classic boats. FIG. 8b shows a shape of a comparable boat hull but produced according to the present invention. Therefore the shell can have a complex shape which is distinguished by the small surface of the submerged part 26. The latter is considerably shorter than the part 25 of the traditional shell of FIG. 8a and is limited on the central part of the shell. This small area 26 gives the boat increased maneuverability, in particular allowing it to rotate 180 ° at high speeds.

Figures 9a and b illustrate the aesthetic improvements that the inventio allows to bring to the shape of the shell. Figure 9b shows a very streamlined hull shape that can be used on "yacht" type boats. The construction cost of such yachts is significantly reduced compared to the cost of a yacht built around a traditional hull, remaining similar to that of a barge according to FIG. 9a.

Figures 10a and 10b illustrate another advantage of the invention, which resides in the economy of raw materials. Indeed, FIG. 10a shows framework elements, that is to say members typical of traditional boat hulls. These elements are characterized by their curved shape. Figure 10b shows frame elements used in the context of the present invention. These are elements whose edges are straight. In the figures, falling raw materials are indicated by hatched portions. It can be seen that the losses are considerably lower in the case of the invention according to FIG. 10b.

Figure l ia shows a part of a frame 30 provided with a sole 31 In the typical case of the prior art, the sole is attached by welding. The same reinforcing effect of a frame can be obtained in the case of the invention by simple folding carried out with an industrial folder along a longitudinal line 32 of a section of sections 34 of rectilinear shape and with parallel edges.

Another advantage which the present invention provides will be described with reference to FIGS. 5 and 12. FIG. 5 represents a boat hull whose shape corresponds to that illustrated in FIGS. 3 to 6. It can be seen that U-shaped profiles are fixed to the flat outer faces of the bottom wall 3 of the sides of the hull flanks having the general reference 37 and of other surfaces immersed in water generally designated by the number 3 These U-shaped profiles extend in the direction longitudinal of the boat and fixed by welding on their load-bearing side. The profiles 35 are advantageously made of steel and have a width of a few centimeters. They can perform a certain number of functions.

They are able to perform the function of stiffening elements of the rooster in the longitudinal direction. In this function, they can replace internal longitudinal stiffening elements such as for example the longitudinal members 12 and 24 shown in FIG. 3. The presence of transverse and longitudinal stiffening elements, especially of c last, inside the hull, requires the installation of an additional floor. Consequently, the U-shaped elements 35, combined with an appropriate arrangement of the internal transverse stiffening elements, make it possible to eliminate the traditional additional floor, which increases the useful internal space of the hull.

The U-shaped sections 36 sometimes allow the removal of a certain number of devices currently necessary on a traditional boat which they are without any inconvenience, sometimes constitute real improvements pa compared to conventional devices when they fulfill their functions. It is thus noted that these U-shaped profiles can fulfill the function of means of protection against mooring shocks or resulting from collision with floating objects, functions which in the case of boats of traditional structure are accomplished by additional specific means reported on l external face of the hull, but only locally. The U-shaped elements due to their longitudinal arrangement on the external face limit boat drift and thus make it possible to eliminate specific anti-drift devices such as traditional keels or fins.

Another important advantage of the external profiles 35 is that they can constitute conductive elements of a cooling agent and be incorporated into the internal cooling devices of the boat. In fact, the U-shaped profiles when welded to the external face of the shell form therewith channels which are connected to internal elements of the cooling circuit, by the bridging conductors which pass through the shell. . Cooling circuits are then obtained which can serve as many installations as necessary in the boat without the layout constraints that conventional systems present. In the case of the invention, the shell can be considered over its entire surface as a heat exchanger.

Since the constituent elements of the shell are flat fac elements, the U-shaped profiles 36 can be fixed to these wall elements by welding, which can be carried out automatically and industrially. Consequently, the considerable advantages resulting from the presence of these U-shaped elements require only low additional expenditure much lower than the costs necessary for the installation and installation of the devices they replace or improve.

As emerges from the description which has just been made, the process for manufacturing boat hulls according to the invention has numerous advantages. Indeed, it allows a less expensive manufacture of hulls whose shape can be established according to technical, utility and aesthetic considerations depending on the use of the boat. The manufacture of the hulls from planar, prefabricated elements also allows a representation by model of the hull, which is practically not possible with curved hull shapes of the state of the art.

More specifically, it has been found, in the context of carrying out the present invention, that a shell having the general shape shown in FIGS. 3 and 4 and drawn in a simpler manner in FIG. 12a can be used as a basic shell shape from which shell shapes suitable for different uses can be developed, as shown in Figures 12b to 12d.

It can be seen that all of these shell shapes have in common a flat bottom wall element 10, two front oblique bottom elements 21, two rear oblique bottom elements 17, two parallel side plank elements 14, two front plank elements 18 and two rear edge elements 15. The four shell shapes are distinguished only by the dimensions and the shape of the various wall elements. Despite the construction of this hull from planar wall elements, they have very good hydrodynamic properties depending on the use for which the boat is intended, whether a restaurant boat for example with a length of 5 meters and with a width of 10 meters, a transport barge (figure 12b) or a central float of a very slender trimaran (figure 12d).

Consequently, the invention makes it possible to design forms of boat hull from a basic hull form with variable and modular geometry pa variation only of a small number of technical parameters. This basic form can be defined by a computer program comprising only a small number of variables. It is by playing on these variables that an optimization of the relationship between performance objectives such as maneuverability, hydrodynamics, usable internal space and the cost of the boat can be obtained, and the small number of parameters to be varied in order to obtain the desired hull makes it possible to accelerate the development of a hull using from a computer.

Thanks to the definition of a basic hull shape, the invention provides a computer-aided design process for the design of hull shapes for boats, and the hulls thus designed to be produced at relatively low cost, also thanks to the production of the hull from planar wall elements.

Claims

claims

1. A method of manufacturing a hull of a boat, in particular of the flat-bottom type, characterized in that a basic hull form is made up consisting of a predetermined number of planar outer wall elements ( 10, 14, 15, 17, 18, 21) and produces a shell having desired properties for a specific use case, by varying the dimensions and shapes of the plane wall elements.

2. Method according to claim 1, characterized in that the base shell is of the flat bottom type and comprises, as wall elements, an element forming the flat bottom (10), four oblique bottom elements comprising two front elements ( 21) and two rear elements (17), two parallel side plating elements (14), two front plating elements (18) and two rear plating elements (15).

3. Method according to one of claims 1 or 2, characterized in that the o defines the shape of the basic shell using a computer program comprising a reduced number of variable parameters depending on the weak number of planar elements and ensures the search for the hull form of a boat to be produced, by modifying at least some of these variables.

4. A method of manufacturing a hull of a boat, of the type whose deck and walls are assembled using stiffening members, characterized in that the planar wall elements are cut out (10, 14 , 15, 17, 18, 21), after having determined their shapes and dimensions by modulating the elements of the base shell, in flat sheet metal panels, fixed on these planar elements, in the flat state, elements of frames (6, 11, 12) by advantageously automatic welding and builds the hull by assembling bottom parts and thus prefabricated sides.

5. Method according to claim 4, characterized in that the sheet metal elements constituting the bottom walls and sides of the shell are cut using a computer.

6. Method according to one of claims 4 or 5, characterized in that the shell is reinforced in the longitudinal direction by fixing on at least the part of the external surface of the shell, which must be reinforced, profiles ( 35) made of a rigid material, in particular metal, which extend parallel to the longitudinal axis of the shell, the internal space of the shell then being free of longitudinal reinforcements in the aforementioned part.

7. boat hull obtained by implementing the method according to one of claims 1 to 6, of the type having a stiffening structure of the hull with stiffening members, which are fixed to the internal faces of the wall elements, characterized in that these wall elements (10, 14, 15, 17, 18, 21) are planar elements and that the members (6, 11, 12) fixed on the internal face of each wall element have been fixed on this by advantageously automatic welding, before the assembly of the different wall elements.

8. boat hull according to claim 7, provided with stiffening elements of the hull in the longitudinal direction, characterized in that the stiffening elements (35) are formed by profiles in a rigid material in particular metal, such as steel, which are fixed on at least the part of the external surface of the shell which must be reinforced in the longitudinal direction.

9. boat hull according to claim 8, characterized in that the longitudinal stiffening elements (35) are formed by profiles fixed to the external face of the hull along the free edges of their branches.

10. boat hull according to claim 9, characterized in that the U-shaped profiles (35) constitute conductive elements of a cooling agent.