EP0727264B1 - Method and device for the semiautomatic fabrication of reservoirs and casings - Google Patents

Description

The invention relates to a method and a device for producing tanks and ferrules from sheet metal coils, according to the preambles of claims 1 and 3 respectively.

Economic problems arise in manufacturing large diameter steel tanks and ferrules, fact that it is practically excluded, for reasons of space, to realize them elsewhere than on sites. This obliges the manufacturers to open a specific site on the very premises of implementation, by moving a sometimes large team specialized workers (industrial boilermakers, welders, etc.), having only equipment to carry out their task basic, facilitating forming, flame cutting and welding sheet metal plates, the dimensions of which must be limited to facilitate handling and assembly. It therefore results a waste of time, resulting in high cost prices and problems with meeting the deadline imposed by the donor order, relative to the previously established schedule with other trades.

We already know a method of making cylindrical tanks and ferrules from coils of sheet metal, corresponding in the preamble of claim 1, and an application device of this method, corresponding to the preamble of claim 3 (European patent 0 136 581). The ferrule is obtained by pressing the sheet metal strip against the edge of a plate turning of corresponding diameter, on which the said tape is introduced gradually, as it unfolds of the coil and the straightening of the sheet. This process and this device can, however, only be used for the production of thin ferrules, taking into account the flexibility of the sheet required by this forming method.

The object of the present invention is to remedy these drawbacks. This invention, as characterized in claims, solves the problem of defining a method and to create a device allowing semi-automatic realization tanks and ferrules from sheet metal coils.

a) réalisation d'une première virole,

b) mise en place et solidarisation d'un toit sur la première virole,

c) levage de l'ensemble réalisé à l'opération précédente (b) à une hauteur correspondant à la largeur de la bande de tôle,

d) réalisation d'une seconde virole sous la première,

e) solidarisation de la virole réalisée à l'opération (a) à la précédente,

f) reprise des opérations (c) (d) et (e) autant de fois qu'il est nécessaire pour obtenir la hauteur de cuve désirée,

g) mise en place de l'ensemble, réalisé en suivant les opérations ci-dessus, sur un fond de diamètre correspondant et solidarisation de celui-ci à la dernière virole,

se caractérise en ce que :

• les viroles sont réalisées par cintrage/cambrage, au fur et à mesure de l'entraínement et du déroulement de la bobine de tôle,
• lors de la réalisation d'une virole directement sous la précédente, la bande de tôle est progressivement solidarisée à la virole précédente, qu'elle entraíne en rotation ; cette solidarisation progressive à la virole précédente est précédée d'une mise en appui tout aussi progressive de cette virole précédente sur le chant de la bande de tôle en cours de défilement, jusqu'à réalisation complète de cette virole suivante,
• le contrôle du cambrage de la bande de tôle en fonction du rayon R recherché est assuré en permanence, au fur et à mesure de l'entraínement et du défilement de celle-ci.

The process allowing the realization of cylindrical tanks and ferrules from sheet metal coils according to the invention, consisting in carrying out the following operations:

a) making a first ferrule,

b) installation and securing of a roof on the first ferrule,

c) lifting of the assembly produced in the previous operation (b) to a height corresponding to the width of the sheet metal strip,

d) creation of a second shell under the first,

e) joining of the shell made in operation (a) to the previous one,

f) resumption of operations (c) (d) and (e) as many times as necessary to obtain the desired tank height,

g) installation of the assembly, produced by following the above operations, on a base of corresponding diameter and securing it to the last ferrule,

is characterized in that:

• the ferrules are produced by bending / bending, as and when the sheet metal coil is driven and unwound,
• during the production of a ferrule directly under the previous, the sheet metal strip is gradually secured to the previous ferrule, it rotates; this progressive joining to the previous ferrule is preceded by an equally progressive pressing of this previous ferrule on the edge of the sheet metal strip during scrolling, until complete completion of this following ferrule,
• the control of the bending of the sheet metal strip as a function of the radius R sought is permanently ensured, as and when it is driven and scrolled.

According to a variant of the method according to the invention, the cambering of the sheet metal strip is preceded by a dressing operation of this one.

The device for implementing the method according to the invention described above, comprising drive means, bending and permanent control of bending and scrolling of the strip of sheet metal, as well as means of transverse cutting of docking and longitudinal welding of the sheet, is characterized in that the means of training and bending of the sheet metal strip consist of two rollers motorized, one of which is fixed and the other recalled to it by a jack, and a movable roller, located downstream of the first two, whose movement is ensured by a jack in function of the curvature to be given to the sheet, in that the means of permanent control of the bending and running of the strip of sheet metal consist respectively of a proximity detector and a coding wheel, in that it comprises associated rollers lifting cylinders regularly distributed over a circumference to constitute a merry-go-round of corresponding diameter to that of the shell to be obtained, intended to gradually support sheet metal after bending, and in what it comprises a roller tractor motorized.

Preferably the proximity sensor is located at the top and in alignment of the obtuse angle bisector formed by two integral arms one from the other and comprising, at their free ends, a calibrated support roller.

Advantageously, the calibrated rollers are permanently drawn against the face outside of the sheet by a compass recalled to the open position by a gas spring.

The encoder wheel can be permanently pressed against the outside sheet metal by an arm articulated with respect to the connecting axis from the end of the gas spring rod to the articulated element compass reminding the proximity sensor to the sheet.

According to a preferred embodiment variant of the device of application of the method according to the invention, it is provided a means of straightening the sheet, consisting of two rollers vertical boobies, offset from each other, located on the side and other of the sheet metal strip, upstream of the drive means and bending, so that the one located most upstream either side of the spool and the other side is the other side, with some commitment to the scroll plan sheet metal strip.

The advantages obtained, thanks to this invention, consist essentially, in that, by this means, the ferrules are produced directly from the sheet metal coils, respecting, precisely, the required radius and excellent flatness of the joint plans, as well as a precise matching of ferrules facilitating their joining by welding and, consequently, obtain a tight seal at each level, taking into account the quality and regularity of the cords welding carried out in this context.

• les figures 1 à 6 illustrent schématiquement les principales étapes du procédé,
• la figure 7 représente une vue en élévation schématique d'une cuve en cours de réalisation,
• la figure 8 représente une vue de dessus schématique d'une virole en cours de réalisation,
• la figure 9 représente une vue de dessus du système de déroulement, de cambrage, de découpage, d'accostage et de soudage,
• la figure 10 représente une vue de côté en coupe longitudinale de l'ensemble de déroulement et de cambrage,
• la figure 11 représente une vue de dessus de l'ensemble de déroulement et de cambrage selon la figure 10,
• la figure 12 représente une vue de dessus schématique de l'ensemble de déroulement, de cambrage et de contrôle du rayon de cintrage et du défilement de la tôle,
• la figure 13 représente une vue de côté d'un ensemble de déroulement, de dressage et de cambrage,
• la figure 14 représente une vue de dessus d'un ensemble de déroulement, de dressage et de cambrage selon la figure 13.

Other characteristics and advantages will appear in the description which follows of a device for producing tanks, given by way of example, with regard to the appended drawings, in which:

• FIGS. 1 to 6 schematically illustrate the main steps of the process,
• FIG. 7 represents a schematic elevation view of a tank in progress,
• FIG. 8 represents a schematic top view of a ferrule in progress,
• FIG. 9 represents a top view of the unwinding, bending, cutting, docking and welding system,
• FIG. 10 represents a side view in longitudinal section of the unwinding and arching assembly,
• FIG. 11 represents a top view of the unwinding and arching assembly according to FIG. 10,
• FIG. 12 shows a schematic top view of the unwinding, bending and control assembly for the bending radius and the movement of the sheet,
• FIG. 13 represents a side view of an unwinding, dressing and arching assembly,
• FIG. 14 represents a top view of an unwinding, dressing and arching assembly according to FIG. 13.

The device for producing tanks, according to the invention, mainly comprises a carousel 10 consisting of a plate 11 , on which jacks 12 are mounted associated with rollers 13 , as well as an unwinder 20 consisting of a frame 21 , with leveling cylinder 25 supporting the reel holder 22, as well as the unwinding and bending machine 30 essentially consisting of three rollers 31, 32, 33 , including a fixed and motorized 31 , a motorized mobile 32 , or vice versa, ensuring the pinching of the sheet 41 against the fixed roller 31 , under the action of a jack 34, and a non-motorized mobile 33 ensuring the bending of the sheet 41, with control of the bending radius and of the travel sheet metal 41 by means, on the one hand, as regards the control of the bending radius, of a proximity detector 50, placed at the top and in alignment with the bisector of the obtuse angle, formed by two arms 51, 52 secured to each other and comprising, at their free ends, a calibrated roller 53, 54 , the said calibrated rollers 53, 54 being permanently biased against the outer face of the sheet by a compass 55, 56, recalled to the open position by a gas cylinder 57 , and, on the other hand, as regards the control of the movement of the sheet 41 , of a coding wheel 60 , biased against the external face of the sheet 41 by an arm 61 articulated with respect to the axis of connection 58 of the end 571 of the rod of the gas spring 57 to the articulated element 56 of the compass 55, 56 ; a transverse cutting station 70 ; a sheet metal berthing station 80 consisting of rollers 81 situated outside the carousel 10 and rollers 82 situated inside the latter, in concordance with one another; a longitudinal welding station 90 ; and a motorized roller tractor 100 .

By examining in more detail Figures 1 to 6, illustrating the main steps of the process used, in the light of Figures 7, 8 and 9, we note (Figure 1) that a first ferrule 42 is first produced by training of the sheet 41 of the coil 40 by the fixed rollers 31 and motorized presser 32 and bending of said sheet 41 by the bending roller 33, which is positioned as a function of the radius to be obtained. The initiation of the ferrule being thus made, it is then necessary to make the zero point of the course by the precise cut from the start of the strip, then to scroll it with successive engagement on the rollers 13 of the roundabout 10 , until that the perimeter corresponding to the chosen diameter is reached; the cutting unit 70 then cuts the sheet metal strip 41 to separate it from the spool 40 ; the vertical assembly and the corresponding welding are then carried out, the first ferrule 42 is then completed. It then suffices, as shown in FIG. 2, to weld a roof 44 , then, according to FIG. 3, to ensure the lifting of the assembly, using the jacks 12 and the rollers 13 , from a height corresponding to the width of a sheet metal strip, to allow, by successive engagement, the presentation of a new sheet metal strip 41 on the rollers 13 of the cylinders 12 progressively lowered, as the sheet metal 41 travels , as shown in FIGS. 4 and 5, in order to obtain the production of a second ferrule 43, fully supporting the first ferrule 42 equipped with its roof 44 , as shown in FIG. 6, this by proceeding in all points as indicated above for the production of said first ferrule 42.

It is understood that the assembly consisting, after welding, of the ferrules 42 and 43 and of the roof 44 can be raised again, by means of the jacks 12 associated with the rollers 13 constituting the merry-go-round, with a view to adding a third ferrule, proceeding as illustrated in FIGS. 3 to 6, or removed from the carousel, using a lifting means, to be placed and then welded to a bottom.

During the unwinding, again, to make the additional ferrule (s) 43 , the sheet metal strip 41 is engaged, as we have just seen (FIG. 4), under the first ferrule 42, then approached using the rollers 81 , 82 of the docking station 80, which thus press the ferrule 42 and the sheet metal strip 41 . After crossing the last roller of the docking station 80 , a welding station 90 provides automatic spot welding, as the sheet advances. The running of the sheet metal strip 41 is stopped before each merry-go-round post 10 , and a temporary post is slipped under the strip; the jack 12 supporting the ferrule is lowered, the strip advances to the next post, and so on. The cornice welding, ensuring the connection and sealing between the two ferrules 42 and 43, is carried out automatically by a fixed station (not shown). During these operations, the ferrule turns on itself using motorized roller tractors 100 , as well as under the action of the drive rollers 81, 82 of the docking station 80 .

Referring now to Figures 10 and 11, showing the unwinding and arching assembly, it is noted that the coil 40, placed vertically on the coil holder 22, consisting of a rotating crown 220 and a removable plate to central mandrel 221 provided with a lifting ring 222 , is then unrolled, after welding a straight piece at the end of the sheet metal strip 41 , to facilitate engagement of the latter in the two motorized rollers of drive 31 and 32 of the unwinding and bending machine 30 , while being supported vertically by two rollers 23 and 24 mounted at the inlet and at the outlet of the unwinding and bending machine 30 . The sheet metal strip 41 being thus engaged, it then suffices to obtain the pinching of the sheet between the two motorized drive rollers 31, 32 under the action of the jack 34 .

After having entered in the programmable logic controller (not shown) the data relating to the diameters of ferrules to be produced and to the length of bands to be unwound, corresponding to the perimeter of said ferrule 42 , an automatic function positions the bending roller 33 by the intermediate of the jack 35, after engagement of the end of the sheet metal strip 41 under the said roller 33 . After passing over the roller 24 , the sheet metal strip 41 is introduced onto the roundabout 10 , after passing in front of the means for controlling the bending radius and the travel, which will now be described in relation to FIG. 12.

Referring now to FIG. 12, it is noted, first of all, that the position of the bending roller 33 is controlled by the proximity detector 50 , which precisely measures the distance separating it from the external surface of the sheet metal strip 41 , which makes it possible to obtain, by subtraction, the exact measurement, between the calibrated support rollers 53, 54, of the deflection communicated to the sheet metal strip by the bending roller 33 . Corrections, more or less, are thus permanently transmitted to the supply system of the jack 35, ensuring the positioning of the bending roller 33 . The encoder wheel 60 , for its part, transmits, permanently, to the programmable controller, by means of an incremental generator for example, which it drives, the exact length of sheet metal strip 41 already formed, in order to order, at the appropriate time, the stopping of the drive of the motorized rollers 31 and 32, preceding the command to initiate the sectioning by the transverse cutting station 70, consisting of a slide 71 with motorized carriage 72, supporting a tool for section 73 .

Now examining Figures 13 and 14, corresponding to an alternative embodiment of the unwinding and bending machine according to the invention, comprising a means of straightening the sheet as it unfolds, it is noted that the said means consists of two idler rollers 36 and 37 offset, arranged upstream of the roller drive means 31 and 32, so that the roller located most upstream 36 is disposed on the side of the reel 40 and that the other 37 is located on the other side, with a certain engagement in the plane of travel of the sheet metal strip 41 . Thus, the residual curvature resulting from the previous winding is canceled by straightening the sheet under the effect of reverse bending provided by the roller 37 located between the rollers 32 and 36 . In this way, the sheet metal strip leaving the drive means 31, 32, 34 is flat and can then be bent according to a radius R determined by means of the roller 33 combined with the jack 35 .

The device according to the invention, although initially designed for the production of tank ferrules according to the method of the invention, could be, without any particular adaptation, used for the production of plates or strips of flat sheet metal, since it it suffices only to program the control automaton accordingly. Proximity detector 50 will then be asked to verify the absence of deflection, therefore of curvature of the sheet; the bending roller 33 would remain, however, in this case, operating, since it would contribute to the straightening of the sheet metal strip 41 previously wound according to radii of curvature increasing from the middle towards the outside.

Claims (6)

1. A method of making cylindrical tanks and shells from reels of sheeting, which consists in performing the following operations:

   a) making a first shell,

   b) positioning and securing a roof on the first shell,

   c) raising the assembly made by the preceding operation (b) to a height corresponding to the width of the strip of sheeting,

   d) making a second shell underneath the first,

   e) securing the shell made in operation (a) to the one just formed,

   f) repeating operations (c), (d) and (e) as many times as necessary to produce a tank of the required height,

   g) positioning the assembly made by the above operations on and securing to a base, the diameter of which matches that of the last shell,

   characterised in that :

   the shells are made by bending/cambering as the reel of sheeting is driven and unwound,

   the cambering of the metal sheet is continuously controlled so as to produce the required diameter as it is driven and fed along,

   when a shell is being formed directly underneath the previous one, the strip of sheeting is progressively secured to said previous shell, which it drives in rotation; this securing process takes place after this previous shell has been moved progressively so that it comes to bear on the edge of the strip of sheeting in the process of being fed until this next shell has been completely formed.
2. A method as claimed in claim 1, characterised in that the strip of sheeting is passed through a process to hold it upright before it is cambered.
3. A device for implementing the method as claimed in claim 1, comprising means for driving (31, 32), cambering (30) and continuously controlling (60) the cambering and feeding of the strip of sheet (41) as well as transverse cutting means (70), means for positioning (80) and welding (90) the sheet longitudinally, characterised in that the means for driving and cambering the strip of sheet (41) consist of two motorised rolls (31, 32), one of which is fixed (31) whilst the other (32) is biassed towards it by means of a cylinder (34), and a mobile roll (33) located downstream of the first two (31, 32), the displacement of which is operated by a cylinder (35) as a function of the curvature to be imparted to the sheet, and in that the means for continuously controlling the cambering and feeding of the strip of sheet (41) consist respectively of a proximity detector (50) and an indexing wheel (60); it has rollers (13) associated with lifting cylinders (12) spaced regularly around a circumference so as to form a carousel (10) of a diameter matching that of the shell (42) to be produced, designed to gradually support the sheet (41) after cambering, and it has a tractor mechanism with motorised rollers (100).
4. A device as claimed in claim 3 for implementing the method as claimed in claims 1 and 2, characterised in that it has means for retaining the sheet upright comprising two loose, vertical rolls (36, 37), moveable parallel with the roll (32) displaced by a cylinder, one offset from the other, located on either side of the strip of sheet (41) upstream of the driving and cambering means, such that the one located the farthest upstream (36) is arranged alongside the reel (40) and the other (37) is arranged on the other side, engaging to a certain degree in the feeding plane of the strip of sheet (41).
5. A device as claimed in claim 3 or 4, characterised in that the proximity detector (50) is located at the apex and in alignment with the bisector of the obtuse angle subtended by two arms (51, 52) joined one to the other and having at their free ends a calibrated support roller (53, 54); said calibrated rollers (53, 54) being permanently biassed against the external face of the sheet (41) by means of calipers (55, 56) biassed into an open position by means of a gas cylinder (57).
6. A device as claimed in claim 3 or 4, characterised in that the indexing wheel (60) is permanently biassed against the external face of the sheet (41) by means of an arm (61) which pivots about a linking pin (58) at the end (571) of the rod of the gas cylinder (57) with the articulated element (56) of the calipers (55, 56) biassing the proximity detector (50) towards the sheet (41).

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