FR2751247A1 - PROCESS FOR MANUFACTURING A METAL BOTTLE INTENDED TO CONTAIN A PRESSURIZED FLUID - Google Patents

Abstract

The invention relates to a method of manufacturing a metal bottle intended to contain a pressurized fluid comprising a body of generally cylindrical shape designed either in two parts in the form of two half-shells assembled by welding, or in three parts. , the bottom (12) and the semi-elliptical cover (11) being attached to the upper and lower end of a ferrule (6). This method is characterized in that a half-shell, a bottom (12) or a cover (11) is produced by stamping in at least three passes of a sheet of thickness less than or equal to 4 mm maintained, during each of the stamping passes preceding the last, by means of clamps whose profile is determined according to the shape imparted to said sheet during the pass immediately to follow.

Description

1 2751247

  The invention relates to a method of manufacturing a metal bottle intended to contain a pressurized fluid comprising a generally cylindrical body of section less than or equal to 400 mm provided with a cover and a bottom of approximately shape semi-elliptical, this bottle being designed, either in two parts in the form of two assembled half-shells

  by welding, that is to say in three parts the bottom and the semi-lid

  elliptical being attached by welding to the upper and lower end of a ferrule, a half-shell, a bottom or a cover being designed by stamping so as to define a part of concave semi-elliptical shape extended, at the periphery, by a collar

  cylindrical of greater or lesser height.

  As already specified above, the invention relates to the field of bottles intended to contain a pressurized fluid, more particularly a non-flammable gas, such as products

refrigerants such as Freon.

  The bottles currently designed for the transport of this type of pressurized fluid are either made of steel, which poses the problem of their weight, or made of aluminum and, in this case,

  comes the concept of the cost of manufacturing such bottles.

  In addition, the disposable bottle is being refused in more and more countries for reasons of pollution and recycling needs

  very important not to mention the cost by the fact of a single circuit.

  In fact, whatever the nature of the material composing these

  bottles, their production cost poses, in itself, a big problem.

  It should first of all be recalled, in this regard, that these bottles have a body of generally cylindrical shape provided with a cover and a substantially semi-elliptical bottom. In fact, the present invention relates, more particularly, to

  small bottles, either less than or equal to 400 mm.

  Substantially, such a bottle is designed in two or three parts. In the first case, two half-shells are made which are made integral by welding to each other, substantially, in the horizontal median plane of the bottle. As part of a three-part bottle there is a ferrule at the end

2 2751247

  upper and lower of which we just relate, by

  weld, the bottom and the cover of semi-elliptical shape.

  Ultimately, such a cover or bottom takes a shape substantially similar to a half-shell insofar as they both comprise a part of concave semi-elliptical shape which is extended, at the periphery, by a cylindrical neck of

more or less important height.

  These parts are produced by stamping a sheet knowing that this stamping is carried out in a single pass during which said sheet is held using side-clamps. It is obvious that, the metal is, under these conditions, highly stressed to such an extent that it results in a particularly significant reduction in the thickness of the initial sheet. This inevitably leads to an increase in the hardness of the metal which no longer meets the elongation criteria tolerated by the standards applicable in the field. It follows the obligation to carry out heat treatments of these bottles in order to give back to the

  metal all or part of its initial physical characteristics.

  The present invention is intended to respond to the aforementioned problem, this through a process making it possible, in particular, to avoid this significant reduction in the thickness of the sheet between its initial shape and its stamped shape which, ultimately, allows the use of sheets of smaller thickness at the start. In addition, the material being only slightly stressed during its forming, it is possible to dispense with the heat treatments usually used. It should be noted, in this regard, that certain current welding techniques, in particular by laser, also avoid excessive rises in temperature liable to modify the physical characteristics of the metal and

requiring annealing.

  To this end, the invention relates to a method of manufacturing a metal bottle intended to contain a pressurized fluid comprising a generally cylindrical body of section less than or equal to 400 mm, provided with a cover and a bottom. substantially semi-elliptical, this bottle being designed either

3 2751247

  in two parts in the form of two half-shells assembled by

  welding, that is to say in three parts the bottom and the semi-lid

  elliptical being attached by welding to the upper and lower end of a ferrule, a half-shell or a bottom or a cover being designed by stamping so as to define a part of concave semi-elliptical shape extended, at the periphery, by a cylindrical neck of greater or lesser height, characterized in that a half-shell, a bottom or a cover is produced by stamping in at least three passes of a sheet of thickness less than or equal to 4 mm maintained, before each of the stamping passes preceding the last, by means of clamps whose profile is determined according to the shape imparted to the sheet during the pass immediately to be followed. According to the invention, during the first drawing pass, the peripheral edges of the sheet intended to design a half-shell, a bottom or a cover, are raised at an angle less than 35 relative to the initial horizontal plane while that during the second pass said peripheral edges of the sheet are raised at an angle at most equal to

    with respect to this initial horizontal plane.

  Finally, it is only during the last pass that the peripheral edge of the sheet is raised so as to form the cylindrical neck corresponding to a half-shell, a bottom or a

lid.

  Thus, the implementation of the method according to the invention allows the sheet to be stressed only slightly during each of the drawing passes knowing, precisely, that the profile of the side clamps is progressive, avoiding working exclusively on

the elongation of the metal.

  In fact, the process according to the invention has more the aim of forming the sheet rather than deforming it in accordance with the processes.

implemented so far.

  It is obvious that the production gains resulting from the present invention are considerable. We note, in this regard,

4 2751247

  that they are not the result of a change of material, insofar as one continues to use a sheet corresponding to a

easily recyclable material.

  It is also important to note that due to the reduced stresses to which the sheet is subjected, it can, if

  if necessary, be coated, before forming, with an anti-

  corrosion such as zinc plating or the like, again avoiding the application of such a coating to the finished product, an operation which is often more costly for a result of

lower quality.

  Other objects and advantages of the present invention

  will appear during the description which follows relating to

  to an embodiment which is given only by way of example

indicative and not limiting.

  Understanding this description will be facilitated by

  referring to the attached drawing in which: - Figures 1 and 2 show schematically and partially, bottles, in particular intended to contain a pressurized fluid, formed, respectively, in two and three parts; - Figures 3, 4 and 5 illustrate, schematically, a stamping in three passes of a bottom or a cover of a

such bottle.

  As shown in Figures 1 and 2, the present invention relates to the field of metal bottles, in particular intended to contain a pressurized fluid, more particularly a gas

  flammable, such as refrigerants such as freon.

  Such a bottle 1 comprises a body of generally cylindrical shape knowing, in this regard, that the present invention attaches, more particularly, to bottles whose cross section

is of the order of 400 mmn at most.

  It can be designed in two or three parts. In the first case, said bottle 1 is made from two half-shells 2, 3 comprising a part 4 of concave shape, substantially semi-elliptical extended, at the periphery, by a neck 5, in this case cylindrical. These two half-shells 2, 3 are, in

2751247

  definitive made integral with one another by means of a weld joint situated substantially in the horizontal median plane

from bottle 1.

  In the case of a bottle i produced in three parts, as shown in FIG. 2, this comprises a ferrule 6 produced from a sheet of which the vertical edges 7 are just assembled, by welding and after bending. , 8. At the upper 9 and lower 10 end of this ferrule 6 are attached, by welding, a cover 11 and a bottom 12. The latter have a configuration similar to the two half-shells 2, 3 insofar as they comprise , here again, a part 4A of concave shape, substantially semi-elliptical extended, at the periphery, by a neck 5A in particular cylindrical, this latter being quite simply of height

more reduced.

  This shape of the half-shells 2, 3 or, as the case may be, of the cover 11 and of the bottom 12 is obtained by stamping a sheet metal T, in particular of steel. In this regard and according to the invention, the stamping operation is carried out in at least three passes P1, P2, P3 illustrated schematically in Figures 3, 4 and 5 of the accompanying drawings. Due to the type of application of said bottles 1, a sheet T of thickness is retained

less than or equal to 4 mm.

  In addition, according to another characteristic of the method according to the invention, before each of the stamping passes P1, P2, preceding the last P3, the sheet T is held by means of side clamps 13, 14, 15 whose profile is determined according to the shape given to this sheet during the pass P1, P2

immediately to follow.

  Thus, as visible in FIG. 1, the sidewall clamp 13, coming to hold the sheet metal T on its peripheral edge before the descent of the punch 16, has a profile so that this peripheral edge of the sheet metal T conforms, under the momentum of this sidewall 13, so as to define an extension, substantially without rupture, of the concave shape 17 which is defined,

  precisely, this punch 16 during its descent.

6 2751247

  It should be observed, in this regard, that during this first pass P1, the sheet T is thus deformed so that its peripheral edge B forms, relative to the plane 18 of the sheet T

  initial, an angle a at most equal to 35.

  The deformation imprinted on this sheet T during the second pass P2 is such that this peripheral edge B forms, with respect to the initial plane 18, an angle a which is at most equal to 50. We notice

  that, again (see Figure 4 of the attached drawings), the clamp

  flank 14 is profiled so that said peripheral edge B of the sheet T constitutes an extension without rupture with respect to the shape printed by the punch 16A during this second

pass P2.

  Finally, during the last pass P3, the peripheral edge B of the sheet T is lifted vertically so as to define the cylindrical neck 5, 5A. In this regard, during this last pass P3 the sidewall clamp 15 has the simple aim of maintaining, at the start of operation, the peripheral edge B of the sheet T, while allowing it when the punch 16B is lowered , to come and marry the matrix M. Due to the low stresses imparted to the sheet T during its forming, it can be coated, beforehand, by an anti-corrosion protection of the galvanization type. Indeed, these low stresses avoid any heat treatment of the annealing stabilization type, generally essential in the context of existing processes for the manufacture of this type of bottle 1. It will be noted, in passing, that the sheet metal designing the ferrule 6 can, it also, be provided, of origin with such a coating of

anti-corrosion protection.

  In addition, the welding operations are preferably carried out by means of a laser torch having the advantage

  avoid local overheating of the metal.

  As visible in Figures 1 and 2 of the accompanying drawing, these bottles 1, thus designed according to the method according to the invention, can receive, at their lower part, a foot 19 forming a base and made of synthetic material ,

7 2751247

  advantageously thermoplastic, facilitating the recycling of these bottles 1. This foot 19 is thus shaped so as to match, the concave part 4, 4A of elliptical shape of this part

  bottom of the bottle 1, allowing its bonding by bonding.

  As for the upper part of this bottle 1, it preferably receives by bonding, gripping means 20 in the form of a neck designed in synthetic material, preferably thermoplastic. This neck comprises, in its annular part, extending vertically above the bottle 1,

  openings facilitating the gripping of the latter.

  It is obvious that the bottle i shaped according to the method of the invention can also receive a foot and gripping means of different shape and made of a material other than synthetic. They can, in particular, be in the form of metal parts which are just welded, in particular by laser, on the

bottle 1.

  The advantages arising from the present invention consist in that, for the manufacture of bottles intended to contain a pressurized fluid, one eliminates any heat treatment of a high cost price, besides that one can work sheets of lesser thickness for a result from the point of view of mechanical strength which is identical if not greater. Finally, the invention allows these

  bottles with a lower production cost.

  Although the invention has been described with reference to a particular embodiment, it is understood that it is in no way limited thereto and that it is possible to make various modifications to the forms, materials and combinations of these. various elements,

  without departing from the scope and spirit of the invention.

8 2751247

Claims (11)

Claims   1. Method of manufacturing a metal bottle (1) intended to contain a pressurized fluid comprising a body of generally cylindrical shape, of section less than or equal to 400 mm and provided with a cover and a substantially semi-bottom elliptical, this bottle (1) being designed, either in two parts in the form of two half-shells (2, 3) assembled by welding, or in three parts, the bottom (12) and the cover (11) semi-elliptical being added by welding to the upper (9) and lower (10) end of a ferrule (6), a half-shell (2, 3) or a bottom (12) or a cover (11) being designed by stamping of a sheet (T) so as to define a part of semi-elliptical concave shape (4; 4A) extended, at the periphery, by a neck (5; 5A) of more or less significant height, characterized in that the '' a half-shell (2, 3), a bottom (12) or a cover (11) are produced by stamping in at least three passes (P1, P2, P3 ) of a sheet of thickness less than or equal to 4 mm, maintained, before each of the stamping passes (P1, P2) preceding the last (P3) by means of clamps (13, 14) whose profile is determined according to the shape given to the sheet during the pass (P1, P2) immediately to follow.   2. Method according to claim 1, characterized in that the flank clamp (13, 14) coming to hold the sheet (T) on its peripheral edge (B) before the descent of a stamping punch (16, 16A ) has a profile so that the peripheral edge (B) of the sheet conforms, under the impulse of this sidewall clamp (13, 14) so as to define an extension, substantially without rupture, of the concave shape ( 17) which is defined by said punch (16, 16A).   3. Method according to any one of the claims   above, characterized in that during the first drawing pass (P1) the sheet (T) is thus deformed so that its peripheral edge (B) forms, relative to the plane (18) of the   initial sheet (T), an angle (a) at most equal to 35. 9 2751247   4. Method according to any one of the claims   above, characterized in that the deformation imparted to the sheet (T) during the second pass (P2) is such that its peripheral edge (B) forms, relative to the initial plane (18) of said sheet (T) , an angle (a) which is at most equal to 50.   5. Method according to any one of the claims   previous, characterized in that during the last pass (P3) one comes to raise, vertically, the peripheral edge   (B) of the sheet (T) so as to define the neck (5; 5A).   6. Method according to claim 5, characterized in that during the last drawing pass (P3) the flank clamp (15) maintains, at the start of operation, the peripheral edge (B) of the sheet (T) while authorizing it, when lowering the   stamping punch (16B), to come to marry a matrix (M).   7. Method according to any one of the claims   previous, characterized by the fact that a sheet (T), intended to be shaped in shape, defines, as the case may be, a half-shell (2, 3), a bottom (12), a cover (11) or a ferrule (6) is coated, beforehand, with an anticorrosion protection, of the type metallization.   8. Method according to any one of claims   above, characterized in that after forming, as appropriate, two half-shells (2, 3) or a bottom (12), a cover (11) and a ferrule (6), we proceed to their assembly   by welding using a laser torch.   9. Method according to any one of the claims   above, characterized in that there is attached, in particular by gluing, a foot (19) made of synthetic material, advantageously thermoplastic, at the level of the lower part of a bottle (1) designed and assembled according to the stages of the defined process in the claims 1 to 8.   10. Method according to any one of the claims   previous, characterized in that after design and assembly of a bottle (1), it receives in particular by gluing at its upper part of the gripping means 2751247   (20) in the form of a neck made of synthetic material, preferably thermoplastic, comprising, in its annular part extending vertically above said bottle   (1), openings facilitating the gripping of the latter.   11. Method according to any one of claims 1 to 8,   characterized in that after design and assembly of the bottle (1) it receives a foot and gripping means   in the form of metal parts added by laser welding.