FR2852538A1 - Sleeving procedure for tubular articles used e.g. in armaments consists of injecting sleeve components between article and inner mould - Google Patents

Abstract

The procedure consists of injecting the components of a sleeve between outer (2A) and inner (2B) mould sections, the outer section being the article to be sleeved. The inner section of the mould, fitted coaxially inside the outer section, is in the form of a metal structure with its outer surface formed by a series of shutters positioned round a triangular frame (11) reinforced with a lattice (12) and mounted on a welded base. The shutters, three in number, are deployed on hinges to form a perfect cylinder with inflatable seals (28) in their joints, and retracted to remove the inner mould when the sleeve has been made. The injected materials used to form the sleeve comprise a syntactic foam of a resin matrix filled with hollow microballs of aluminium silicate, transferred by means of a buffer vessel with nitrogen under pressure, and a levelling resin injected with the aid of a two-way pump.

Description

The technical sector of the present invention is that

  devices used to make the lining of small or large parts, as well as that of the lining processes using such devices. More particularly, the parts on which it is desired to make a liner are of the tubular capacity type.

  In the field of jackets in general, the prior art is known of conventional jacketing devices and methods of the jacketing type by chemical means, by plating or even by stress. In the more particular field of the invention relating to that of tubular-shaped capacities, this type of prior art is also known, the embodiment most used in recent years being that consisting in prefabricating the shirt to the dimensions of the tube to be lined, then fix it by a mechanical or chemical process.

  All of the devices and methods listed above however have major drawbacks which could not be tolerated in particular with a view to using jacketed tubes for example in certain armament technologies.

  Indeed, one of the major drawbacks lies in the need to carry out an expensive upstream prefabrication of the jacket, directly resulting in constraints in terms of time. In addition, in these types of embodiments, it is imperative to limit as much as possible the manufacturing tolerances of the materials admitted into the capacities, which consequently results in additional costs due to the manufacture of the assembly. Finally, one of the main drawbacks of the embodiments of the prior art stems from the need to obtain perfect reproducibility from one tube to the other, which when using a prefab involves very difficult adaptation and costly of the shirt with residual deformation of the capacities.

  The object of the present invention therefore consists in presenting both a device used to produce a liner and a method using such a device, while overcoming the aforementioned drawbacks characteristic of previous embodiments. The object of the invention is therefore to get rid of the prefabrication phase of the shirt and to obtain a greater tolerance margin between the part to be jacketed and the part to be integrated into the shirt, this last criterion being d 'all the more important when the part to be lined is large.

  For this, the subject of the invention is a device used to make the lining of tubular-shaped capacities, this device further comprising a mold having a first and a second part capable, once assembled, of defining the geometry of a shirt. Materials constituting the liner, injected between said first and second parts of the mold, are capable of being joined to the first part of the mold, this first part being directly constituted by the part to be lined.

  Preferably, the lining is carried out between an internal surface of the part to be coated and an external surface of the second part of the mold, these two surfaces being cylindrical or other and of identical axis.

  The invention also relates to a lining process using such a device.

  An advantage of the invention resides in the increased geometric freedom of the material placed in the capacity and in the freedom from the interposition of a prefabricated insert of constant thickness between the capacity and the material.

  In the method and the device according to the invention, by a simple injection molding step, the desired shape of the shirt is obtained with the precise dimensions and desired profiles. This shape is, due to the production by molding, straight away smooth without having to perform other operations; the part is then also vacuum tight.

  Another advantage of the invention makes it possible, thanks to molding, to obtain a faithful reproducibility of the geometry from one capacity to another, while adapting to the residual deformations of said capacities. In addition, using inflatable seals used in a particular embodiment 10 of the invention, these seals being positioned in the locations of the capacities where it is desired to obtain openings, this makes it possible to dispense with the realization of '' machining or drilling operations which would be longer to perform and moreover very expensive.

  The molding solution as described in the invention advantageously makes it possible to carry out localized interventions on a damaged system, thus facilitating the work of partial repairs. This is facilitated by the system used which ensures homogeneity and recovery of the repair product.

  The invention advantageously aims to use low cost materials requiring no particular development or special manufacturing.

  Another advantage of the invention relates to the modularity of the devices and methods according to the invention, which do not require any prefabrication upstream or any specific storage. This is how this invention offers designers the ability to be able to change the dimensions and profiles of the shirt until very late in the making of the device; on the one hand before the machining of the mold, on the other hand it is also possible to modify the dimensions and profiles of the mold after this machining by means of a reloading of the zones that the designers wish to resume.

  Other characteristics and advantages of the invention will appear in the detailed, non-limiting description, below.

  This description will be made with reference to the accompanying principle drawings in which: - Figure 1 shows a perspective view of the entire device according to the invention applied to the lining of a capacity, - Figure 2 shows a longitudinal section of the device according to the invention applied to the lining of a capacity, - Figure 3 shows a top view in section 15 (along AA of Figure 2) of the device showing the position of the flaps at the time of introduction / extraction of one of the elements constituting the device (flaps in the withdrawn position), and ready to receive the injection of the materials (flaps in the deployed position); this section also presents part of the mechanical means for operating the shutters, - Figure 4 shows a top view in section (along BB of Figure 2) of the device showing the other 25 mechanical means for operating and connecting the shutters.

  Referring to Figures 1 to 4, we see a device 1 used to make the liner of tubular capacity, or any other type of parts to be lined. The description of a particular embodiment of the invention will be made with reference to the figures listed above, representing the principle of a portion of a capacity.

  This device comprises a mold 2 consisting of two parts 2A and 2B. The first part 2A of the mold 2 as well as the second part 2B of the mold 2 are produced in such a way that when they are assembled, they define the geometry of a jacket 3 which it is desired to manufacture.

  The part to be lined (tube for example) constitutes the first part 2A of the mold 2. Once the materials 4 and 5 constituting the liner 3 are injected between the two parts of the mold 2, these join to this first part 2A of the mold 2. In other words, this part 2A of the mold is used not only for molding the liner 3, but when the molding is finished, the liner 3 is directly fixed to this first part 2A constituted by the part that the 'we want to shirt.

  A lining can be carried out either on the external or internal surface of a part; according to a particular embodiment of the invention and in relation to a capacity, we carry out a lining on the internal surface 7 of the part to be lined 2A, which consequently will also be delimited by the external surface 8 of the second part 2B mold 2.

  In the following description, the reference 2A will be

  used interchangeably to reference the first part of mold 2 or the part to be lined. In reality, these two expressions denote a single and same part constituted, according to the particular application of the invention described below, by a capacity.

  More particularly with reference to FIG. 2, we can dissociate the second part 2B of the mold 2 into two very distinct elements.

  First of all, this second part 2B is composed of a metallic structure 9 which is used inter alia to support the elements of the mold intended to be in contact with the materials 4 and 5 to be injected. This metal structure 9 itself comprises several elements, namely a metal frame 11 in the form of a tripod stiffened by a welded tubular trellis 12, as well as a welded mechanic base 13. This base 13 is multi-functional in the sense that it ensures both adjustment and centering of the plate on which the metal frame 11 rests.

  This mechanically welded base 13 is provided with primary mechanical means 15, 16 and 17 enabling the required functions 10 to be fulfilled. These means firstly include centering pins 15 for correct and precise positioning of the second part 2B of the mold 2 inside the first part 2A of this same mold 2. They also include screw systems 16 and 17 having on the one hand a function of adjusting the attitude with respect to the ground and on the other hand a function of horizontal blocking of the second part 2B of the mold inside the first part 2A. For this latter function, an example could be given of a simple set of three screws arranged at 1200, which is sufficient to obtain the expected result.

  The second part 2B of the mold 2 is also composed of a set of flaps 10 forming the outer surface 8 of this part of the mold. This assembly 10 rests on the metal structure 9 on which it is positioned and then assembled. The set of flaps 10 is, according to a particular embodiment of the invention (Figure 3), consisting of three flaps including two side flaps 18, 19 and a central flap 20 which, when assembled to each other, form a perfect cylinder materializing the outer surface 8 of the second part 2B of the mold 2.

  According to a particular embodiment of the invention, these flaps 18, 19 and 20 are made on a wooden template on which are grafted in negative, all the terminal geometric shapes thereof. The resistant structure of the shutters is made of a double sandwich type composite with double cores and skins. The skin is made of glass resin composite with an epoxy matrix or any other material whose nature meets a specific need such as heat and stiffness. The core, for its part, is preferably made of balsa or any other core material meeting a specific need such as inertia, insulation or even the thermal bridge. The structure therefore has in the end a machinable coating presented in the form of tiles, it should be noted that coats of arms can be distributed over the height of the flaps 18, 19, 20 to ensure high rigidity of this part of the mold in the vertical position.

  This set of flaps 10 previously described is therefore capable of being positioned on the metal structure 9 by means of secondary mechanical means 21, 22 and 23. The side flaps 18 and 19 are articulated on the metal structure 9 to the using mechanically welded hinges 21, then maneuvered using screw jacks 22 fitted with 20 limit stops limiting their opening to the exact diameter specified (Figures 3 and 4). These screw jacks 22 fulfill the dual function of deploying and removing them, depending on whether one is before or after the injection phase of the materials 4 and 5 constituting the jacket 25 3. This specific operation of the flaps side 18 and 19 is therefore provided by disengageable screw nut systems. As regards the central flap 20, the latter is not articulated like the previous ones, but has a translation system 23 preferably composed of several identical mechanical assemblies 30 distributed equitably over the height of the second part 2B of the mold 2. This system 23 forming an integral part of the secondary mechanical means, it makes it possible to bring the central flap 20 from a withdrawal position to a position where it forms, with the lateral flaps 18 and 19, a perfect cylinder defining the external surface of the second part 2B of the mold 2. Of course, this translation system 23 to which the central flap 5 is directly attached 20 makes it possible to carry out the translational maneuver of the flap in the opposite direction, in particular during demolding operations.

  It should be noted that these secondary mechanical means 21, 22 and 23 in no way support the load of the flaps 10 18, 19 and 20. This function is ensured by the use of sliding supports 14 facilitating their movements.

  Once the flaps are correctly positioned, it is imperative that they are assembled and secured to each other. To do this, the device comprises tertiary mechanical means 24 + 25 and 29 + 30 having the aim of joining the various elements together, but also ensuring the maintenance of the flaps 18, 19 and 20 in a fixed and rigorous position.

  These assemblies made using mechanical tertiary means 20 consist of mechanical assemblies 24 + 25 and 29 + 30 mechanically welded in two parts. The first mechanical assembly 24 + 25 thus consists of the element 24 equipped with a nut 31 embedded and welded. This first element is fixed to the side flaps 18 and 19. The element 25 constituting the second part of this mechanical assembly has a hole 32 allowing the passage of a screw 33 ensuring one of the connections of the central flap 20 to the side flaps 18 and 19. The second mechanical assembly 29 + 30, which is more elaborate, is itself made up of the element 29 fixed on the side flaps 18 and 30 19. It has a hole fitted with a nut 34 embedded and welded, a centering pin 35 as well as a non-through hole 36. The element 30 constituting the second part of this mechanical assembly has a hole 37 allowing the passage of the screw 38 which, in addition to the inflatable seals 26 , ensures total locking of the flaps 18, 19 and 20 both in the machining phase of the second part 2B of the mold 2 and both in the injection phase of the materials 4 and 5. A 5 drilling 39 allows the passage of the centering pin 35. A nut 40 welded under the passage of the centering pin 35 in order to allow the use of a screw 41 as a pressure screw during the demolding phase. During this action, the pressure screw 41 is supported in the non-through hole 36.

  According to a preferred embodiment of the invention, the device 1 comprises inflatable seals 26.

  These are located between the first and second parts of the mold 2 when these are assembled. These inflatable seals 26 are preferably placed in machining operations 28 previously carried out on the second part 2B of the mold, then sanded in order to obtain a good surface quality of the Ra type less than 3.2. It is, moreover, the surface quality which will advantageously be required over the entire external surface 8 of the second part 2B 20 of the mold 2.

  These seals can take place at different locations. For example, they can be located between the different flaps 18, 19 and 20 in order to guarantee the seal and the geometry of the mold. To guarantee perfect geometry during the injection of materials 4 and 5, these seals are installed and pressurized before the machining phase and before the injection phase of materials 4 and 5.

  Another location for these inflatable seals 26 is located on the circumference of the second part 2B of the mold at the bottom, and around the lateral opening 43 (FIG. 1) of the part to be lined 2A, if the latter requires one. Their role is then to ensure the seal between the second part 2B of the mold 2 and the part to be lined 2A, as well as to guarantee a lossless molding of the materials 4 and 5 constituting the liner 3. Finally, we can cite as location for these seals, two generators of the second part 2B of the mold which would be diametrically opposite, with the sole aim of separating two materials 4 and 5 of different nature.

  According to a preferred embodiment of the invention, the device 1 includes inserts 27. The integration of these into the jacket 3 takes place during the injection phase 10 of the materials 4 and 5. It is first of all advisable to distribute in height and angularly the location of the inserts 27 on the second part 2B of the mold 2, by means of a machine tool. This makes the holes and screws are put in place through the plating of the part of the mold concerned. Once the inserts 27 have been put in place on the screws, these are embedded in the materials 4 and 5 constituting the jacket 3; the screws can then be extracted when these inserts 27 have been embedded and then secured to the jacket 3.

  The device 1 according to the invention comprises injection points 42 equipped with non-return systems to avoid backflow of product, making it possible to administer the materials 4 and 5 between the two parts of the mold. The injection is then carried out so that there is no air pocket formation during the operation.

  When the various machining operations are carried out on the second part 2B of the mold, control operations can be carried out such as those relating to the geometry, the circularity, the concentricity or even the straightness of the various elements.

  The materials 4 and 5 used to constitute the jacket 3 are of a different nature. We can first cite the first of them which is of the syntactic foam type composed of epoxy matrix resin charged with hollow microspheres of alumina silicate; its injection is preceded by a mixing then the transfer is carried out using a buffer tank under nitrogen pressure. The second material is of the wedging resin type with an epoxy matrix injected using a double-acting pump.

  To improve the performance and results of the device 1, certain surfaces may undergo specific preparations, in particular in order to facilitate demolding. By way of example, one can make on the workpiece to line 2A a shot peening and then a degreasing. Once preheated, it is applied to it, within twenty-four hours of the shot blasting, a primer itself coated with a specific protection. As for the second part 2B of the mold 2, it can be dusted off perfectly 15 before degreasing and covering with release agents, any element in contact with the materials 4 and 5. This also applies to the inflatable seals and the screws supporting the inserts 27, which can follow the same treatment to obtain better release from the mold.

  Finally, we can point out that various variants can be added to the device 1 described above, such as the automation and motorization of the maneuvering systems, the installation of a precise guidance system for carrying out the introduction and removal of the second 25 part 2B of the mold 2, the addition of a mixer and a large capacity injection machine, or even the installation of an additional temperature regulation system inside the second part 2B of the mold.

  The invention also relates to a lining process for tubular-shaped capacities using a device 1 as described above. The main stages of this process consist in assembling the two parts of the mold 2, in injecting the materials 4 and 5 constituting the jacket 3, then in a demolding operation concretized by the withdrawal of the second part 2B from the mold 2 .

  The first step of this process consists in the introduction of the second part 2B of the mold 2 inside the first part 2A of the same mold 2.

  However, as described above, this first step can be preceded by the following successive steps. We can first of all note the positioning of the flaps 18, 19 and 20 on the metal structure 9.

  Then, there is the positioning and assembly of the flaps 18, 19 and 20 using the primary mechanical means 15, 16 and 17, secondary 21, 22 and 23 and tertiary 24 + 25 and 29 + 30. Following this, the machining 28 is carried out on the secondary part 2B of the mold 2, then the seals 26 are put in place and inflated. A last step may consist in positioning the inserts 27 on the second part 2B of the mold 2 ..

  In addition, between the step of injecting the materials 4 and 5 constituting the jacket 3 and that constituted by the removal of the second part 2B from the mold 2 mentioned above, it is also possible to interpose the following different steps: firstly the deflation of the seals 26, followed by the removal of the screws holding the inserts 27 then the carrying out of the maneuvers aimed at moving the central flap followed by the side flaps 18 and 19.

  Of course, various modifications can be made by those skilled in the art to the device and to the method described above, only by way of nonlimiting example, without departing from the protective framework defined by the

appended claims.

Claims (1)

  1- Device (1) used to make the lining of tubular-shaped capacities, this device (1) further comprising a mold (2) having a first (2A) and a second (2B) part capable, once assembled, of define the geometry of a jacket (3), characterized in that materials (4 and 5) constituting the jacket (3), injected between said first (2A) and second (2B) parts of the mold (2), are able to be joined to the first part (2A) of this mold (2), this first part (2A) being directly constituted by the part to be lined; 2Device (1) used to make the lining of tubular-shaped capacities according to claim 1, characterized in that the lining is carried out between an inner surface (7) of the piece to be lined (2A) and an outer surface (8) of the second part (2B) of the mold (2), these two surfaces (7 and 8) being cylindrical and of identical axis; 3Device (1) used to make the lining of tubular-shaped capacities according to claim 1 or claim 2, characterized in that the second part (2B) of the mold (2) comprises a metal structure (9) and a set of flaps (10) forming the outer surface (8) of this part of the mold; 4- Device (1) used to make the lining of tubular capacities according to claim 3, characterized in that the metal structure (9) is further constituted by a metal frame (11) in the form of a tripod stiffened by a trellis (12), as well as a mechanically welded base (13) for centering and adjusting the plate on which the metal frame (11) rests; 5Device (1) used to make the lining of tubular capacities according to claim 4, characterized in that the mechanically welded base (13) comprises primary mechanical means (15, 16, 17) for adjusting the 10 l trim, horizontal locking and centering of this second part (2B) of the mold (2) relative to the first part (2A) of this same mold (2); 6- Device (1) used to make the lining of 15 tubular capacities according to claim 5, characterized in that the primary mechanical means (15, 16, 17) are of the centering pin type (15) or screw (16 , 17); 7- Device (1) used to make the lining of 20 tubular capacities according to any one of claims 3 to 6, characterized in that the set of flaps (10) comprises three flaps (18, 19 and 20) forming a perfect cylinder once positioned, including two side flaps (18 and 19) and a central flap (20), each consisting of a double sandwich type composite; 8Device (1) used to make the lining of tubular capacities according to claim 7, characterized in that the positioning of the flaps (18, 19 and 30 20) on the metal structure (9) to obtain a perfect cylinder is carried out using secondary mechanical means (21, 22 and 23) of the mechanically welded hinge type (21), screw jack systems (22) and a translation system (23) of the central flap (20); 9- Device (1) used to make the lining of 5 tubular capacities according to claim 7 or claim 8, characterized in that the central flap (20) is suitable, when the two side flaps (18 and 19) are assembled, to be translated using the translation system (23), from a withdrawal position to a position o 10 it forms with the side flaps (18 and 19) a perfect cylinder and vice versa, from a position o the flaps form a perfect cylinder at a withdrawal position; 10- Device (1) used to make the lining of 15 tubular capacities according to any one of claims 7 to 9, characterized in that the assembly of the flaps (18, 19 and 20) between them is effected by through tertiary mechanical means (24 + 25 and 29 + 30) of the clamping type (24 + 25) with fixing screws (33) 20 and mechanical assemblies (29 + 30) of the centering pin type (35) on the 'one of the flaps and a passage (39) for centering pin (35) and fixing screw (38) on a contiguous flap; 11- Device (1) used to make the lining of tubular capacities according to any one of the preceding claims, characterized in that the device (1) comprises, when said first (2A) and second (2B) parts of the mold (2) are assembled, inflatable seals (26) placed in machining operations (28) 30 previously produced on the second part (2B) of the mold (2); 12- Device (1) used to make the lining of tubular capacities according to claim 11, characterized in that the inflatable seals (26) are located between the different flaps (18, 19 and 20), on the circumference of the second part (2B) of the mold (2) in the lower part, as well as on two generatrices of this second part of the mold which are diametrically opposite; 13- Device (1) used to make the liner of 10 tubular capacities according to any one of the preceding claims, characterized in that the device (1) has inserts (27) supported by screws which can be removed when the inserts (27) were submerged and then secured to the jacket (3); 15 14Device (1) used to make the lining of tubular capacities according to any one of the preceding claims, characterized in that the injection of the materials (4 and 5) constituting the jacket (3) is done by 20 l intermediate injection points (42) equipped with non-return systems; 15- Device (1) used to make the lining of tubular capacities according to any one of the preceding claims, characterized in that the materials (4 and 5) injected constituting the jacket (3) are on the one hand syntactic foam type composed of matrix resin loaded with hollow microspheres of alumina silicate previously kneaded then transferred using a buffer tank under nitrogen pressure, and on the other hand of the type epoxy matrix setting resin injected using a double-acting pump; 1'7 16Device (1) used to make the lining of tubular capacities according to any one of the preceding claims, characterized in that all of the elements in contact with the products (4 and 5) injected are previously covered with 'release agents; 17 A process for producing a liner for tubular capacities using a device according to any one of claims 1 to 16, characterized in that it comprises the following steps (a) assembly of the second part (2B) of the mold (2) with the first part (2A) of this same mold (2) directly constituted by the part to be lined, (b) injection of the materials (4 and 5) constituting the liner (3), (c) removal of the second part (2B) of the mold (2); 18 A process for producing a liner for tubular capacities according to claim 17, characterized in that step (a) of the method is preceded by the following steps: (d) installation of flaps (18, 19 and 20) on a metal structure (9), (e) positioning of inserts (27) on the second part 25 (2B) of the mold (2), (f) positioning and inflation of the seals (26 ) at the flaps (18, 19 and 20), (g) positioning and adjustments of the metal structure (9) and flaps (10) assembly using primary mechanical means (15, 16 and 17), 19- A method of producing a liner for tubular capacities according to claim 17 or claim 18, characterized in that between steps (b) and (c), the following steps are carried out: (h) deflation seals (26), (i) removing the screws holding the inserts (27), (j) operating the side flaps (18 and 19) and the central flap (20).